Harmsen, Martin C

Stevens, Hieronymus P

Tuin, A Jorien

van der Lei, Berend

van Dongen, Joris A

English

ARTS repository - University of Groningen

   University of GroningenThe Difference between Stromal Vascular Fraction Isolation and Fat Emulsificationvan Dongen, Joris A; Tuin, A Jorien; Harmsen, Martin C; van der Lei, Berend; Stevens,Hieronymus PPublished in:Plastic and Reconstructive SurgeryDOI:10.1097/PRS.0000000000006366IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2020Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Dongen, J. A., Tuin, A. J., Harmsen, M. C., van der Lei, B., & Stevens, H. P. (2020). The Differencebetween Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation.Plastic and Reconstructive Surgery, 145(1), 232e-233e. https://doi.org/10.1097/PRS.0000000000006366CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 13-02-2023Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. 232ePlastic and Reconstructive Surgery • January 2020The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for CentrifugationSir:Stromal vascular fraction is a great breakthrough in regenerative medicine because it improves both scars and wound healing. Therefore, a growing num-ber of mechanical dissociation procedures have been developed that destroy adipocytes and subsequently isolate tissue stromal vascular fraction.1 Most proce-dures are based on shearing of tissue: powerful strok-ing of lipoaspirate through a small channel in a transfer hub to break down adipocytes and reduce volume, and preserving cell-to-cell communication, including extra-cellular matrix.1Since the mid-1990s, a comparable shuffling tech-nique has already been used to emulsify lipoaspirate.2 Emulsification is performed to evenly divide all compo-nents of adipose tissue (i.e., fat and infiltration fluid), Daisuke Mito, M.D.Masakazu Kurita, M.D., Ph.D.Shimpei Miyamoto, M.D., Ph.D.Mutsumi Okazaki, M.D., Ph.D.Department of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo HospitalTokyo, JapanCorrespondence to Dr. MitoDepartment of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo Hospital7-3-1, Hongo, BunkyoTokyo 1138655, Japan063m2089@gmail.comDISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. Holm C, Tegeler J, Mayr M, Becker A, Pfeiffer UJ, Mühlbauer W. Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience. Microsurgery 2002;22:278–287. 2. Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary study. Microsurgery 2009;29:509–514. 3. Unno N, Nishiyama M, Suzuki M, et al. A novel method of measuring human lymphatic pumping using indo-cyanine green fluorescence lymphography. J Vasc Surg. 2010;52:946–952. 4. Landsman ML, Kwant G, Mook GA, Zijlstra WG. Light-absorbing properties, stability, and spectral stabilization of indocyanine green. J Appl Physiol. 1976;40:575–583.resulting in an injectable substance of comparable vol-ume with intact adipocytes. For good clinical under-standing, it is of importance to distinguish between a mechanical isolation or an emulsification procedure. Based on difference in volume reduction between both techniques, the amount of destroyed adipocytes will differ and the amount of oil after centrifugation can simply distinguish between both types of procedures.In the literature, many mechanical isolation pro-cedures have not included a final centrifugation step.1 Therefore, we also hypothesized that some recently described procedures are mentioned as being isolation procedures (e.g., the nanofat procedure) but are actu-ally emulsification procedures.3 In a short experiment, we processed fat (n = 5) by using two different mechani-cal isolation procedures to isolate tissue stromal vascu-lar fraction (e.g., our own developed fractionation of adipose tissue procedure and the nanofat procedure).3,4 Both mechanical isolation procedures were performed as originally described. As a control for both groups, 10 ml of one-time centrifuged adipose tissue was used. The nanofat sample was centrifuged afterward to see whether oil would appear. Furthermore, all samples were formalin-fixed and embedded in paraffin and stained with toluidine blue to visualize the morphology.The fractionation of adipose tissue procedure resulted in 1 ml of aqueous fraction containing a small pellet fraction, 1 ml of stromal vascular fraction and 8 ml of oil (Fig. 1, left). The nanofat procedure resulted in 2 ml of infiltration fluid and 4 to 5 ml of adipose tis-sue, and had no detectable oil fraction (Fig. 1, right). This was corroborated by toluidine blue staining, which showed more stromal fraction and less intact adipocytes in the isolated stromal vascular fraction prepared by means of the fractionation of adipose tissue procedure as compared to stromal vascular fraction isolated by the nanofat procedure and control fat (data not shown).In our hands, virtually no oil appeared with the nanofat procedure, which indicates that this procedure leaves adipocytes intact. We therefore hypothesize that the difference in fluid content caused by difference in pretreatment of the lipoaspirate (i.e., only decantation for the nanofat procedure versus centrifugation for the fractionation of adipose tissue procedure) apparently protects the adipocytes when forced through the single 2.4-mm-hole Luer-to-Luer transfer.Based on our findings, we can conclude that a sim-ple final centrifugation step can determine the amount of oil as evidence of the amount of destroyed fat. In this way, emulsification procedures can easily be distin-guished from isolation procedures. The fractionation of adipose tissue procedure appears to be a mechani-cal dissociation procedure resulting in a small-volume tissue stromal vascular fraction, whereas the nanofat procedure appears to be an emulsification procedure.DOI: 10.1097/PRS.0000000000006366Joris A. van Dongen, B.Sc.Bey Bergman ClinicsThe Hague, The NetherlandsCopyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. Volume 145, Number 1 • Viewpoints233eDepartment of Pathology and Medical Biology Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsA. Jorien Tuin, M.D.Department of Oral and Maxillofacial SurgeryMartin C. Harmsen, Ph.D.Department of Pathology and Medical BiologyBerend van der Lei, M.D., Ph.D.Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsBey Bergman ClinicsHeerenveen, Zwolle, and Groningen, The NetherlandsHieronymus P. Stevens, M.D., Ph.D.Velthuis KliniekRotterdam, The NetherlandsCorrespondence to Dr. StevensVelthuis Clinic Jan Leentvaarlaan 14-243065 DC Rotterdam, The Netherlandsstevens.hp@gmail.com DISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: A systematic review. J Tissue Eng Regen Med. 2018;12:e261–e274. 2. Toledo LS. Syringe liposculpture: A two-year experience. Aes-thetic Plast Surg. 1991;15:321–326. 3. Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: Basic research and clinical applications. Plast Reconstr Surg. 2013;132:1017–1026. 4. van Dongen JA, Stevens HP, Parvizi M, van der Lei B, Harmsen MC. The fractionation of adipose tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes. Wound Repair Regen. 2016;24: 994–1003.Fig. 1. (Left) Result of the fractionation of adipose tissue procedure. 1, Oily fraction; 2, stromal vas-cular fraction; 3, aqueous fraction containing a small pellet fraction. (Right) Result of the nanofat procedure. 1, Adipose tissue; 2, infiltration fluid.Use of Cavilon for Making Surgical-Site Markings IndelibleSir: Marking of the surgical site is important; especially in plastic surgery. Skin markings are used to design surgical incisions, important landmarks, areas of deepithelialization, and others. Also, markings may be performed in certain positions before the patient is taken on the operating table (e.g., in mammaplasty, the markings are performed with the patient in the erect position).Surgical scrubbing often smudges the preopera-tive markings or can even completely erase them.1 Also, prolonged surgery can expose the markings to body fluids, which can also fade or erase them.Innovative methods of marking the surgical site have been investigated. These may be cumbersome (such as applying henna)2 or can potentially cause hypertrophic scar or keloid (caused by scratching). Various different companies and types of felt-tip pens have also been investigated in an effort to find a more robust ink.3We have assessed the use of Cavilon (3M, Maple-wood, Minn.) to make the markings more indelible. Cavilon is a terpolymer that forms a breathable, trans-parent, protective coating on the skin and results in an acrylate surface that resists removal. It is com-posed of hexamethyldisiloxane (65 to 90%), isooc-tane (5 to 30%), acrylate terpolymer (3 to 12%), and 

The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification:A Crucial Role for Centrifugation

Proceedings - University of Groningen

   University of GroningenThe Difference between Stromal Vascular Fraction Isolation and Fat Emulsificationvan Dongen, Joris A; Tuin, A Jorien; Harmsen, Martin C; van der Lei, Berend; Stevens,Hieronymus PPublished in:Plastic and Reconstructive SurgeryDOI:10.1097/PRS.0000000000006366IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2020Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Dongen, J. A., Tuin, A. J., Harmsen, M. C., van der Lei, B., & Stevens, H. P. (2020). The Differencebetween Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation.Plastic and Reconstructive Surgery, 145(1), 232e-233e. https://doi.org/10.1097/PRS.0000000000006366CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 04-06-2022Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. 232ePlastic and Reconstructive Surgery • January 2020The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for CentrifugationSir:Stromal vascular fraction is a great breakthrough in regenerative medicine because it improves both scars and wound healing. Therefore, a growing num-ber of mechanical dissociation procedures have been developed that destroy adipocytes and subsequently isolate tissue stromal vascular fraction.1 Most proce-dures are based on shearing of tissue: powerful strok-ing of lipoaspirate through a small channel in a transfer hub to break down adipocytes and reduce volume, and preserving cell-to-cell communication, including extra-cellular matrix.1Since the mid-1990s, a comparable shuffling tech-nique has already been used to emulsify lipoaspirate.2 Emulsification is performed to evenly divide all compo-nents of adipose tissue (i.e., fat and infiltration fluid), Daisuke Mito, M.D.Masakazu Kurita, M.D., Ph.D.Shimpei Miyamoto, M.D., Ph.D.Mutsumi Okazaki, M.D., Ph.D.Department of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo HospitalTokyo, JapanCorrespondence to Dr. MitoDepartment of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo Hospital7-3-1, Hongo, BunkyoTokyo 1138655, Japan063m2089@gmail.comDISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. Holm C, Tegeler J, Mayr M, Becker A, Pfeiffer UJ, Mühlbauer W. Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience. Microsurgery 2002;22:278–287. 2. Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary study. Microsurgery 2009;29:509–514. 3. Unno N, Nishiyama M, Suzuki M, et al. A novel method of measuring human lymphatic pumping using indo-cyanine green fluorescence lymphography. J Vasc Surg. 2010;52:946–952. 4. Landsman ML, Kwant G, Mook GA, Zijlstra WG. Light-absorbing properties, stability, and spectral stabilization of indocyanine green. J Appl Physiol. 1976;40:575–583.resulting in an injectable substance of comparable vol-ume with intact adipocytes. For good clinical under-standing, it is of importance to distinguish between a mechanical isolation or an emulsification procedure. Based on difference in volume reduction between both techniques, the amount of destroyed adipocytes will differ and the amount of oil after centrifugation can simply distinguish between both types of procedures.In the literature, many mechanical isolation pro-cedures have not included a final centrifugation step.1 Therefore, we also hypothesized that some recently described procedures are mentioned as being isolation procedures (e.g., the nanofat procedure) but are actu-ally emulsification procedures.3 In a short experiment, we processed fat (n = 5) by using two different mechani-cal isolation procedures to isolate tissue stromal vascu-lar fraction (e.g., our own developed fractionation of adipose tissue procedure and the nanofat procedure).3,4 Both mechanical isolation procedures were performed as originally described. As a control for both groups, 10 ml of one-time centrifuged adipose tissue was used. The nanofat sample was centrifuged afterward to see whether oil would appear. Furthermore, all samples were formalin-fixed and embedded in paraffin and stained with toluidine blue to visualize the morphology.The fractionation of adipose tissue procedure resulted in 1 ml of aqueous fraction containing a small pellet fraction, 1 ml of stromal vascular fraction and 8 ml of oil (Fig. 1, left). The nanofat procedure resulted in 2 ml of infiltration fluid and 4 to 5 ml of adipose tis-sue, and had no detectable oil fraction (Fig. 1, right). This was corroborated by toluidine blue staining, which showed more stromal fraction and less intact adipocytes in the isolated stromal vascular fraction prepared by means of the fractionation of adipose tissue procedure as compared to stromal vascular fraction isolated by the nanofat procedure and control fat (data not shown).In our hands, virtually no oil appeared with the nanofat procedure, which indicates that this procedure leaves adipocytes intact. We therefore hypothesize that the difference in fluid content caused by difference in pretreatment of the lipoaspirate (i.e., only decantation for the nanofat procedure versus centrifugation for the fractionation of adipose tissue procedure) apparently protects the adipocytes when forced through the single 2.4-mm-hole Luer-to-Luer transfer.Based on our findings, we can conclude that a sim-ple final centrifugation step can determine the amount of oil as evidence of the amount of destroyed fat. In this way, emulsification procedures can easily be distin-guished from isolation procedures. The fractionation of adipose tissue procedure appears to be a mechani-cal dissociation procedure resulting in a small-volume tissue stromal vascular fraction, whereas the nanofat procedure appears to be an emulsification procedure.DOI: 10.1097/PRS.0000000000006366Joris A. van Dongen, B.Sc.Bey Bergman ClinicsThe Hague, The NetherlandsCopyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. Volume 145, Number 1 • Viewpoints233eDepartment of Pathology and Medical Biology Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsA. Jorien Tuin, M.D.Department of Oral and Maxillofacial SurgeryMartin C. Harmsen, Ph.D.Department of Pathology and Medical BiologyBerend van der Lei, M.D., Ph.D.Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsBey Bergman ClinicsHeerenveen, Zwolle, and Groningen, The NetherlandsHieronymus P. Stevens, M.D., Ph.D.Velthuis KliniekRotterdam, The NetherlandsCorrespondence to Dr. StevensVelthuis Clinic Jan Leentvaarlaan 14-243065 DC Rotterdam, The Netherlandsstevens.hp@gmail.com DISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: A systematic review. J Tissue Eng Regen Med. 2018;12:e261–e274. 2. Toledo LS. Syringe liposculpture: A two-year experience. Aes-thetic Plast Surg. 1991;15:321–326. 3. Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: Basic research and clinical applications. Plast Reconstr Surg. 2013;132:1017–1026. 4. van Dongen JA, Stevens HP, Parvizi M, van der Lei B, Harmsen MC. The fractionation of adipose tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes. Wound Repair Regen. 2016;24: 994–1003.Fig. 1. (Left) Result of the fractionation of adipose tissue procedure. 1, Oily fraction; 2, stromal vas-cular fraction; 3, aqueous fraction containing a small pellet fraction. (Right) Result of the nanofat procedure. 1, Adipose tissue; 2, infiltration fluid.Use of Cavilon for Making Surgical-Site Markings IndelibleSir: Marking of the surgical site is important; especially in plastic surgery. Skin markings are used to design surgical incisions, important landmarks, areas of deepithelialization, and others. Also, markings may be performed in certain positions before the patient is taken on the operating table (e.g., in mammaplasty, the markings are performed with the patient in the erect position).Surgical scrubbing often smudges the preopera-tive markings or can even completely erase them.1 Also, prolonged surgery can expose the markings to body fluids, which can also fade or erase them.Innovative methods of marking the surgical site have been investigated. These may be cumbersome (such as applying henna)2 or can potentially cause hypertrophic scar or keloid (caused by scratching). Various different companies and types of felt-tip pens have also been investigated in an effort to find a more robust ink.3We have assessed the use of Cavilon (3M, Maple-wood, Minn.) to make the markings more indelible. Cavilon is a terpolymer that forms a breathable, trans-parent, protective coating on the skin and results in an acrylate surface that resists removal. It is com-posed of hexamethyldisiloxane (65 to 90%), isooc-tane (5 to 30%), acrylate terpolymer (3 to 12%), and 

   University of GroningenThe Difference between Stromal Vascular Fraction Isolation and Fat Emulsificationvan Dongen, Joris A; Tuin, A Jorien; Harmsen, Martin C; van der Lei, Berend; Stevens,Hieronymus PPublished in:Plastic and Reconstructive SurgeryDOI:10.1097/PRS.0000000000006366IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2020Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Dongen, J. A., Tuin, A. J., Harmsen, M. C., van der Lei, B., & Stevens, H. P. (2020). The Differencebetween Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation.Plastic and Reconstructive Surgery, 145(1), 232e-233e. https://doi.org/10.1097/PRS.0000000000006366CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 11-09-2023Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. 232ePlastic and Reconstructive Surgery • January 2020The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for CentrifugationSir:Stromal vascular fraction is a great breakthrough in regenerative medicine because it improves both scars and wound healing. Therefore, a growing num-ber of mechanical dissociation procedures have been developed that destroy adipocytes and subsequently isolate tissue stromal vascular fraction.1 Most proce-dures are based on shearing of tissue: powerful strok-ing of lipoaspirate through a small channel in a transfer hub to break down adipocytes and reduce volume, and preserving cell-to-cell communication, including extra-cellular matrix.1Since the mid-1990s, a comparable shuffling tech-nique has already been used to emulsify lipoaspirate.2 Emulsification is performed to evenly divide all compo-nents of adipose tissue (i.e., fat and infiltration fluid), Daisuke Mito, M.D.Masakazu Kurita, M.D., Ph.D.Shimpei Miyamoto, M.D., Ph.D.Mutsumi Okazaki, M.D., Ph.D.Department of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo HospitalTokyo, JapanCorrespondence to Dr. MitoDepartment of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo Hospital7-3-1, Hongo, BunkyoTokyo 1138655, Japan063m2089@gmail.comDISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. Holm C, Tegeler J, Mayr M, Becker A, Pfeiffer UJ, Mühlbauer W. Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience. Microsurgery 2002;22:278–287. 2. Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary study. Microsurgery 2009;29:509–514. 3. Unno N, Nishiyama M, Suzuki M, et al. A novel method of measuring human lymphatic pumping using indo-cyanine green fluorescence lymphography. J Vasc Surg. 2010;52:946–952. 4. Landsman ML, Kwant G, Mook GA, Zijlstra WG. Light-absorbing properties, stability, and spectral stabilization of indocyanine green. J Appl Physiol. 1976;40:575–583.resulting in an injectable substance of comparable vol-ume with intact adipocytes. For good clinical under-standing, it is of importance to distinguish between a mechanical isolation or an emulsification procedure. Based on difference in volume reduction between both techniques, the amount of destroyed adipocytes will differ and the amount of oil after centrifugation can simply distinguish between both types of procedures.In the literature, many mechanical isolation pro-cedures have not included a final centrifugation step.1 Therefore, we also hypothesized that some recently described procedures are mentioned as being isolation procedures (e.g., the nanofat procedure) but are actu-ally emulsification procedures.3 In a short experiment, we processed fat (n = 5) by using two different mechani-cal isolation procedures to isolate tissue stromal vascu-lar fraction (e.g., our own developed fractionation of adipose tissue procedure and the nanofat procedure).3,4 Both mechanical isolation procedures were performed as originally described. As a control for both groups, 10 ml of one-time centrifuged adipose tissue was used. The nanofat sample was centrifuged afterward to see whether oil would appear. Furthermore, all samples were formalin-fixed and embedded in paraffin and stained with toluidine blue to visualize the morphology.The fractionation of adipose tissue procedure resulted in 1 ml of aqueous fraction containing a small pellet fraction, 1 ml of stromal vascular fraction and 8 ml of oil (Fig. 1, left). The nanofat procedure resulted in 2 ml of infiltration fluid and 4 to 5 ml of adipose tis-sue, and had no detectable oil fraction (Fig. 1, right). This was corroborated by toluidine blue staining, which showed more stromal fraction and less intact adipocytes in the isolated stromal vascular fraction prepared by means of the fractionation of adipose tissue procedure as compared to stromal vascular fraction isolated by the nanofat procedure and control fat (data not shown).In our hands, virtually no oil appeared with the nanofat procedure, which indicates that this procedure leaves adipocytes intact. We therefore hypothesize that the difference in fluid content caused by difference in pretreatment of the lipoaspirate (i.e., only decantation for the nanofat procedure versus centrifugation for the fractionation of adipose tissue procedure) apparently protects the adipocytes when forced through the single 2.4-mm-hole Luer-to-Luer transfer.Based on our findings, we can conclude that a sim-ple final centrifugation step can determine the amount of oil as evidence of the amount of destroyed fat. In this way, emulsification procedures can easily be distin-guished from isolation procedures. The fractionation of adipose tissue procedure appears to be a mechani-cal dissociation procedure resulting in a small-volume tissue stromal vascular fraction, whereas the nanofat procedure appears to be an emulsification procedure.DOI: 10.1097/PRS.0000000000006366Joris A. van Dongen, B.Sc.Bey Bergman ClinicsThe Hague, The NetherlandsCopyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. Volume 145, Number 1 • Viewpoints233eDepartment of Pathology and Medical Biology Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsA. Jorien Tuin, M.D.Department of Oral and Maxillofacial SurgeryMartin C. Harmsen, Ph.D.Department of Pathology and Medical BiologyBerend van der Lei, M.D., Ph.D.Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsBey Bergman ClinicsHeerenveen, Zwolle, and Groningen, The NetherlandsHieronymus P. Stevens, M.D., Ph.D.Velthuis KliniekRotterdam, The NetherlandsCorrespondence to Dr. StevensVelthuis Clinic Jan Leentvaarlaan 14-243065 DC Rotterdam, The Netherlandsstevens.hp@gmail.com DISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: A systematic review. J Tissue Eng Regen Med. 2018;12:e261–e274. 2. Toledo LS. Syringe liposculpture: A two-year experience. Aes-thetic Plast Surg. 1991;15:321–326. 3. Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: Basic research and clinical applications. Plast Reconstr Surg. 2013;132:1017–1026. 4. van Dongen JA, Stevens HP, Parvizi M, van der Lei B, Harmsen MC. The fractionation of adipose tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes. Wound Repair Regen. 2016;24: 994–1003.Fig. 1. (Left) Result of the fractionation of adipose tissue procedure. 1, Oily fraction; 2, stromal vas-cular fraction; 3, aqueous fraction containing a small pellet fraction. (Right) Result of the nanofat procedure. 1, Adipose tissue; 2, infiltration fluid.Use of Cavilon for Making Surgical-Site Markings IndelibleSir: Marking of the surgical site is important; especially in plastic surgery. Skin markings are used to design surgical incisions, important landmarks, areas of deepithelialization, and others. Also, markings may be performed in certain positions before the patient is taken on the operating table (e.g., in mammaplasty, the markings are performed with the patient in the erect position).Surgical scrubbing often smudges the preopera-tive markings or can even completely erase them.1 Also, prolonged surgery can expose the markings to body fluids, which can also fade or erase them.Innovative methods of marking the surgical site have been investigated. These may be cumbersome (such as applying henna)2 or can potentially cause hypertrophic scar or keloid (caused by scratching). Various different companies and types of felt-tip pens have also been investigated in an effort to find a more robust ink.3We have assessed the use of Cavilon (3M, Maple-wood, Minn.) to make the markings more indelible. Cavilon is a terpolymer that forms a breathable, trans-parent, protective coating on the skin and results in an acrylate surface that resists removal. It is com-posed of hexamethyldisiloxane (65 to 90%), isooc-tane (5 to 30%), acrylate terpolymer (3 to 12%), and 

NARCIS 

The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation

   University of GroningenThe Difference between Stromal Vascular Fraction Isolation and Fat Emulsificationvan Dongen, Joris A; Tuin, A Jorien; Harmsen, Martin C; van der Lei, Berend; Stevens,Hieronymus PPublished in:Plastic and Reconstructive SurgeryDOI:10.1097/PRS.0000000000006366IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2020Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Dongen, J. A., Tuin, A. J., Harmsen, M. C., van der Lei, B., & Stevens, H. P. (2020). The Differencebetween Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation.Plastic and Reconstructive Surgery, 145(1), 232e-233e. https://doi.org/10.1097/PRS.0000000000006366CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 01-11-2023Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. 232ePlastic and Reconstructive Surgery • January 2020The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for CentrifugationSir:Stromal vascular fraction is a great breakthrough in regenerative medicine because it improves both scars and wound healing. Therefore, a growing num-ber of mechanical dissociation procedures have been developed that destroy adipocytes and subsequently isolate tissue stromal vascular fraction.1 Most proce-dures are based on shearing of tissue: powerful strok-ing of lipoaspirate through a small channel in a transfer hub to break down adipocytes and reduce volume, and preserving cell-to-cell communication, including extra-cellular matrix.1Since the mid-1990s, a comparable shuffling tech-nique has already been used to emulsify lipoaspirate.2 Emulsification is performed to evenly divide all compo-nents of adipose tissue (i.e., fat and infiltration fluid), Daisuke Mito, M.D.Masakazu Kurita, M.D., Ph.D.Shimpei Miyamoto, M.D., Ph.D.Mutsumi Okazaki, M.D., Ph.D.Department of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo HospitalTokyo, JapanCorrespondence to Dr. MitoDepartment of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo Hospital7-3-1, Hongo, BunkyoTokyo 1138655, Japan063m2089@gmail.comDISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. Holm C, Tegeler J, Mayr M, Becker A, Pfeiffer UJ, Mühlbauer W. Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience. Microsurgery 2002;22:278–287. 2. Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary study. Microsurgery 2009;29:509–514. 3. Unno N, Nishiyama M, Suzuki M, et al. A novel method of measuring human lymphatic pumping using indo-cyanine green fluorescence lymphography. J Vasc Surg. 2010;52:946–952. 4. Landsman ML, Kwant G, Mook GA, Zijlstra WG. Light-absorbing properties, stability, and spectral stabilization of indocyanine green. J Appl Physiol. 1976;40:575–583.resulting in an injectable substance of comparable vol-ume with intact adipocytes. For good clinical under-standing, it is of importance to distinguish between a mechanical isolation or an emulsification procedure. Based on difference in volume reduction between both techniques, the amount of destroyed adipocytes will differ and the amount of oil after centrifugation can simply distinguish between both types of procedures.In the literature, many mechanical isolation pro-cedures have not included a final centrifugation step.1 Therefore, we also hypothesized that some recently described procedures are mentioned as being isolation procedures (e.g., the nanofat procedure) but are actu-ally emulsification procedures.3 In a short experiment, we processed fat (n = 5) by using two different mechani-cal isolation procedures to isolate tissue stromal vascu-lar fraction (e.g., our own developed fractionation of adipose tissue procedure and the nanofat procedure).3,4 Both mechanical isolation procedures were performed as originally described. As a control for both groups, 10 ml of one-time centrifuged adipose tissue was used. The nanofat sample was centrifuged afterward to see whether oil would appear. Furthermore, all samples were formalin-fixed and embedded in paraffin and stained with toluidine blue to visualize the morphology.The fractionation of adipose tissue procedure resulted in 1 ml of aqueous fraction containing a small pellet fraction, 1 ml of stromal vascular fraction and 8 ml of oil (Fig. 1, left). The nanofat procedure resulted in 2 ml of infiltration fluid and 4 to 5 ml of adipose tis-sue, and had no detectable oil fraction (Fig. 1, right). This was corroborated by toluidine blue staining, which showed more stromal fraction and less intact adipocytes in the isolated stromal vascular fraction prepared by means of the fractionation of adipose tissue procedure as compared to stromal vascular fraction isolated by the nanofat procedure and control fat (data not shown).In our hands, virtually no oil appeared with the nanofat procedure, which indicates that this procedure leaves adipocytes intact. We therefore hypothesize that the difference in fluid content caused by difference in pretreatment of the lipoaspirate (i.e., only decantation for the nanofat procedure versus centrifugation for the fractionation of adipose tissue procedure) apparently protects the adipocytes when forced through the single 2.4-mm-hole Luer-to-Luer transfer.Based on our findings, we can conclude that a sim-ple final centrifugation step can determine the amount of oil as evidence of the amount of destroyed fat. In this way, emulsification procedures can easily be distin-guished from isolation procedures. The fractionation of adipose tissue procedure appears to be a mechani-cal dissociation procedure resulting in a small-volume tissue stromal vascular fraction, whereas the nanofat procedure appears to be an emulsification procedure.DOI: 10.1097/PRS.0000000000006366Joris A. van Dongen, B.Sc.Bey Bergman ClinicsThe Hague, The NetherlandsCopyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. Volume 145, Number 1 • Viewpoints233eDepartment of Pathology and Medical Biology Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsA. Jorien Tuin, M.D.Department of Oral and Maxillofacial SurgeryMartin C. Harmsen, Ph.D.Department of Pathology and Medical BiologyBerend van der Lei, M.D., Ph.D.Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsBey Bergman ClinicsHeerenveen, Zwolle, and Groningen, The NetherlandsHieronymus P. Stevens, M.D., Ph.D.Velthuis KliniekRotterdam, The NetherlandsCorrespondence to Dr. StevensVelthuis Clinic Jan Leentvaarlaan 14-243065 DC Rotterdam, The Netherlandsstevens.hp@gmail.com DISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: A systematic review. J Tissue Eng Regen Med. 2018;12:e261–e274. 2. Toledo LS. Syringe liposculpture: A two-year experience. Aes-thetic Plast Surg. 1991;15:321–326. 3. Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: Basic research and clinical applications. Plast Reconstr Surg. 2013;132:1017–1026. 4. van Dongen JA, Stevens HP, Parvizi M, van der Lei B, Harmsen MC. The fractionation of adipose tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes. Wound Repair Regen. 2016;24: 994–1003.Fig. 1. (Left) Result of the fractionation of adipose tissue procedure. 1, Oily fraction; 2, stromal vas-cular fraction; 3, aqueous fraction containing a small pellet fraction. (Right) Result of the nanofat procedure. 1, Adipose tissue; 2, infiltration fluid.Use of Cavilon for Making Surgical-Site Markings IndelibleSir: Marking of the surgical site is important; especially in plastic surgery. Skin markings are used to design surgical incisions, important landmarks, areas of deepithelialization, and others. Also, markings may be performed in certain positions before the patient is taken on the operating table (e.g., in mammaplasty, the markings are performed with the patient in the erect position).Surgical scrubbing often smudges the preopera-tive markings or can even completely erase them.1 Also, prolonged surgery can expose the markings to body fluids, which can also fade or erase them.Innovative methods of marking the surgical site have been investigated. These may be cumbersome (such as applying henna)2 or can potentially cause hypertrophic scar or keloid (caused by scratching). Various different companies and types of felt-tip pens have also been investigated in an effort to find a more robust ink.3We have assessed the use of Cavilon (3M, Maple-wood, Minn.) to make the markings more indelible. Cavilon is a terpolymer that forms a breathable, trans-parent, protective coating on the skin and results in an acrylate surface that resists removal. It is com-posed of hexamethyldisiloxane (65 to 90%), isooc-tane (5 to 30%), acrylate terpolymer (3 to 12%), and 

University of Groningen

   University of GroningenThe Difference between Stromal Vascular Fraction Isolation and Fat Emulsificationvan Dongen, Joris A; Tuin, A Jorien; Harmsen, Martin C; van der Lei, Berend; Stevens,Hieronymus PPublished in:Plastic and Reconstructive SurgeryDOI:10.1097/PRS.0000000000006366IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2020Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Dongen, J. A., Tuin, A. J., Harmsen, M. C., van der Lei, B., & Stevens, H. P. (2020). The Differencebetween Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation.Plastic and Reconstructive Surgery, 145(1), 232e-233e. https://doi.org/10.1097/PRS.0000000000006366CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 29-04-2023Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. 232ePlastic and Reconstructive Surgery • January 2020The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for CentrifugationSir:Stromal vascular fraction is a great breakthrough in regenerative medicine because it improves both scars and wound healing. Therefore, a growing num-ber of mechanical dissociation procedures have been developed that destroy adipocytes and subsequently isolate tissue stromal vascular fraction.1 Most proce-dures are based on shearing of tissue: powerful strok-ing of lipoaspirate through a small channel in a transfer hub to break down adipocytes and reduce volume, and preserving cell-to-cell communication, including extra-cellular matrix.1Since the mid-1990s, a comparable shuffling tech-nique has already been used to emulsify lipoaspirate.2 Emulsification is performed to evenly divide all compo-nents of adipose tissue (i.e., fat and infiltration fluid), Daisuke Mito, M.D.Masakazu Kurita, M.D., Ph.D.Shimpei Miyamoto, M.D., Ph.D.Mutsumi Okazaki, M.D., Ph.D.Department of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo HospitalTokyo, JapanCorrespondence to Dr. MitoDepartment of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo Hospital7-3-1, Hongo, BunkyoTokyo 1138655, Japan063m2089@gmail.comDISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. Holm C, Tegeler J, Mayr M, Becker A, Pfeiffer UJ, Mühlbauer W. Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience. Microsurgery 2002;22:278–287. 2. Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary study. Microsurgery 2009;29:509–514. 3. Unno N, Nishiyama M, Suzuki M, et al. A novel method of measuring human lymphatic pumping using indo-cyanine green fluorescence lymphography. J Vasc Surg. 2010;52:946–952. 4. Landsman ML, Kwant G, Mook GA, Zijlstra WG. Light-absorbing properties, stability, and spectral stabilization of indocyanine green. J Appl Physiol. 1976;40:575–583.resulting in an injectable substance of comparable vol-ume with intact adipocytes. For good clinical under-standing, it is of importance to distinguish between a mechanical isolation or an emulsification procedure. Based on difference in volume reduction between both techniques, the amount of destroyed adipocytes will differ and the amount of oil after centrifugation can simply distinguish between both types of procedures.In the literature, many mechanical isolation pro-cedures have not included a final centrifugation step.1 Therefore, we also hypothesized that some recently described procedures are mentioned as being isolation procedures (e.g., the nanofat procedure) but are actu-ally emulsification procedures.3 In a short experiment, we processed fat (n = 5) by using two different mechani-cal isolation procedures to isolate tissue stromal vascu-lar fraction (e.g., our own developed fractionation of adipose tissue procedure and the nanofat procedure).3,4 Both mechanical isolation procedures were performed as originally described. As a control for both groups, 10 ml of one-time centrifuged adipose tissue was used. The nanofat sample was centrifuged afterward to see whether oil would appear. Furthermore, all samples were formalin-fixed and embedded in paraffin and stained with toluidine blue to visualize the morphology.The fractionation of adipose tissue procedure resulted in 1 ml of aqueous fraction containing a small pellet fraction, 1 ml of stromal vascular fraction and 8 ml of oil (Fig. 1, left). The nanofat procedure resulted in 2 ml of infiltration fluid and 4 to 5 ml of adipose tis-sue, and had no detectable oil fraction (Fig. 1, right). This was corroborated by toluidine blue staining, which showed more stromal fraction and less intact adipocytes in the isolated stromal vascular fraction prepared by means of the fractionation of adipose tissue procedure as compared to stromal vascular fraction isolated by the nanofat procedure and control fat (data not shown).In our hands, virtually no oil appeared with the nanofat procedure, which indicates that this procedure leaves adipocytes intact. We therefore hypothesize that the difference in fluid content caused by difference in pretreatment of the lipoaspirate (i.e., only decantation for the nanofat procedure versus centrifugation for the fractionation of adipose tissue procedure) apparently protects the adipocytes when forced through the single 2.4-mm-hole Luer-to-Luer transfer.Based on our findings, we can conclude that a sim-ple final centrifugation step can determine the amount of oil as evidence of the amount of destroyed fat. In this way, emulsification procedures can easily be distin-guished from isolation procedures. The fractionation of adipose tissue procedure appears to be a mechani-cal dissociation procedure resulting in a small-volume tissue stromal vascular fraction, whereas the nanofat procedure appears to be an emulsification procedure.DOI: 10.1097/PRS.0000000000006366Joris A. van Dongen, B.Sc.Bey Bergman ClinicsThe Hague, The NetherlandsCopyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. Volume 145, Number 1 • Viewpoints233eDepartment of Pathology and Medical Biology Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsA. Jorien Tuin, M.D.Department of Oral and Maxillofacial SurgeryMartin C. Harmsen, Ph.D.Department of Pathology and Medical BiologyBerend van der Lei, M.D., Ph.D.Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsBey Bergman ClinicsHeerenveen, Zwolle, and Groningen, The NetherlandsHieronymus P. Stevens, M.D., Ph.D.Velthuis KliniekRotterdam, The NetherlandsCorrespondence to Dr. StevensVelthuis Clinic Jan Leentvaarlaan 14-243065 DC Rotterdam, The Netherlandsstevens.hp@gmail.com DISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: A systematic review. J Tissue Eng Regen Med. 2018;12:e261–e274. 2. Toledo LS. Syringe liposculpture: A two-year experience. Aes-thetic Plast Surg. 1991;15:321–326. 3. Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: Basic research and clinical applications. Plast Reconstr Surg. 2013;132:1017–1026. 4. van Dongen JA, Stevens HP, Parvizi M, van der Lei B, Harmsen MC. The fractionation of adipose tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes. Wound Repair Regen. 2016;24: 994–1003.Fig. 1. (Left) Result of the fractionation of adipose tissue procedure. 1, Oily fraction; 2, stromal vas-cular fraction; 3, aqueous fraction containing a small pellet fraction. (Right) Result of the nanofat procedure. 1, Adipose tissue; 2, infiltration fluid.Use of Cavilon for Making Surgical-Site Markings IndelibleSir: Marking of the surgical site is important; especially in plastic surgery. Skin markings are used to design surgical incisions, important landmarks, areas of deepithelialization, and others. Also, markings may be performed in certain positions before the patient is taken on the operating table (e.g., in mammaplasty, the markings are performed with the patient in the erect position).Surgical scrubbing often smudges the preopera-tive markings or can even completely erase them.1 Also, prolonged surgery can expose the markings to body fluids, which can also fade or erase them.Innovative methods of marking the surgical site have been investigated. These may be cumbersome (such as applying henna)2 or can potentially cause hypertrophic scar or keloid (caused by scratching). Various different companies and types of felt-tip pens have also been investigated in an effort to find a more robust ink.3We have assessed the use of Cavilon (3M, Maple-wood, Minn.) to make the markings more indelible. Cavilon is a terpolymer that forms a breathable, trans-parent, protective coating on the skin and results in an acrylate surface that resists removal. It is com-posed of hexamethyldisiloxane (65 to 90%), isooc-tane (5 to 30%), acrylate terpolymer (3 to 12%), and 

Crossref

Dissertations of the University of Groningen

   University of GroningenThe Difference between Stromal Vascular Fraction Isolation and Fat Emulsificationvan Dongen, Joris A; Tuin, A Jorien; Harmsen, Martin C; van der Lei, Berend; Stevens,Hieronymus PPublished in:Plastic and Reconstructive SurgeryDOI:10.1097/PRS.0000000000006366IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2020Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Dongen, J. A., Tuin, A. J., Harmsen, M. C., van der Lei, B., & Stevens, H. P. (2020). The Differencebetween Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation.Plastic and Reconstructive Surgery, 145(1), 232e-233e. https://doi.org/10.1097/PRS.0000000000006366CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 19-11-2022Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. 232ePlastic and Reconstructive Surgery • January 2020The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for CentrifugationSir:Stromal vascular fraction is a great breakthrough in regenerative medicine because it improves both scars and wound healing. Therefore, a growing num-ber of mechanical dissociation procedures have been developed that destroy adipocytes and subsequently isolate tissue stromal vascular fraction.1 Most proce-dures are based on shearing of tissue: powerful strok-ing of lipoaspirate through a small channel in a transfer hub to break down adipocytes and reduce volume, and preserving cell-to-cell communication, including extra-cellular matrix.1Since the mid-1990s, a comparable shuffling tech-nique has already been used to emulsify lipoaspirate.2 Emulsification is performed to evenly divide all compo-nents of adipose tissue (i.e., fat and infiltration fluid), Daisuke Mito, M.D.Masakazu Kurita, M.D., Ph.D.Shimpei Miyamoto, M.D., Ph.D.Mutsumi Okazaki, M.D., Ph.D.Department of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo HospitalTokyo, JapanCorrespondence to Dr. MitoDepartment of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo Hospital7-3-1, Hongo, BunkyoTokyo 1138655, Japan063m2089@gmail.comDISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. Holm C, Tegeler J, Mayr M, Becker A, Pfeiffer UJ, Mühlbauer W. Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience. Microsurgery 2002;22:278–287. 2. Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary study. Microsurgery 2009;29:509–514. 3. Unno N, Nishiyama M, Suzuki M, et al. A novel method of measuring human lymphatic pumping using indo-cyanine green fluorescence lymphography. J Vasc Surg. 2010;52:946–952. 4. Landsman ML, Kwant G, Mook GA, Zijlstra WG. Light-absorbing properties, stability, and spectral stabilization of indocyanine green. J Appl Physiol. 1976;40:575–583.resulting in an injectable substance of comparable vol-ume with intact adipocytes. For good clinical under-standing, it is of importance to distinguish between a mechanical isolation or an emulsification procedure. Based on difference in volume reduction between both techniques, the amount of destroyed adipocytes will differ and the amount of oil after centrifugation can simply distinguish between both types of procedures.In the literature, many mechanical isolation pro-cedures have not included a final centrifugation step.1 Therefore, we also hypothesized that some recently described procedures are mentioned as being isolation procedures (e.g., the nanofat procedure) but are actu-ally emulsification procedures.3 In a short experiment, we processed fat (n = 5) by using two different mechani-cal isolation procedures to isolate tissue stromal vascu-lar fraction (e.g., our own developed fractionation of adipose tissue procedure and the nanofat procedure).3,4 Both mechanical isolation procedures were performed as originally described. As a control for both groups, 10 ml of one-time centrifuged adipose tissue was used. The nanofat sample was centrifuged afterward to see whether oil would appear. Furthermore, all samples were formalin-fixed and embedded in paraffin and stained with toluidine blue to visualize the morphology.The fractionation of adipose tissue procedure resulted in 1 ml of aqueous fraction containing a small pellet fraction, 1 ml of stromal vascular fraction and 8 ml of oil (Fig. 1, left). The nanofat procedure resulted in 2 ml of infiltration fluid and 4 to 5 ml of adipose tis-sue, and had no detectable oil fraction (Fig. 1, right). This was corroborated by toluidine blue staining, which showed more stromal fraction and less intact adipocytes in the isolated stromal vascular fraction prepared by means of the fractionation of adipose tissue procedure as compared to stromal vascular fraction isolated by the nanofat procedure and control fat (data not shown).In our hands, virtually no oil appeared with the nanofat procedure, which indicates that this procedure leaves adipocytes intact. We therefore hypothesize that the difference in fluid content caused by difference in pretreatment of the lipoaspirate (i.e., only decantation for the nanofat procedure versus centrifugation for the fractionation of adipose tissue procedure) apparently protects the adipocytes when forced through the single 2.4-mm-hole Luer-to-Luer transfer.Based on our findings, we can conclude that a sim-ple final centrifugation step can determine the amount of oil as evidence of the amount of destroyed fat. In this way, emulsification procedures can easily be distin-guished from isolation procedures. The fractionation of adipose tissue procedure appears to be a mechani-cal dissociation procedure resulting in a small-volume tissue stromal vascular fraction, whereas the nanofat procedure appears to be an emulsification procedure.DOI: 10.1097/PRS.0000000000006366Joris A. van Dongen, B.Sc.Bey Bergman ClinicsThe Hague, The NetherlandsCopyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. Volume 145, Number 1 • Viewpoints233eDepartment of Pathology and Medical Biology Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsA. Jorien Tuin, M.D.Department of Oral and Maxillofacial SurgeryMartin C. Harmsen, Ph.D.Department of Pathology and Medical BiologyBerend van der Lei, M.D., Ph.D.Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsBey Bergman ClinicsHeerenveen, Zwolle, and Groningen, The NetherlandsHieronymus P. Stevens, M.D., Ph.D.Velthuis KliniekRotterdam, The NetherlandsCorrespondence to Dr. StevensVelthuis Clinic Jan Leentvaarlaan 14-243065 DC Rotterdam, The Netherlandsstevens.hp@gmail.com DISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: A systematic review. J Tissue Eng Regen Med. 2018;12:e261–e274. 2. Toledo LS. Syringe liposculpture: A two-year experience. Aes-thetic Plast Surg. 1991;15:321–326. 3. Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: Basic research and clinical applications. Plast Reconstr Surg. 2013;132:1017–1026. 4. van Dongen JA, Stevens HP, Parvizi M, van der Lei B, Harmsen MC. The fractionation of adipose tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes. Wound Repair Regen. 2016;24: 994–1003.Fig. 1. (Left) Result of the fractionation of adipose tissue procedure. 1, Oily fraction; 2, stromal vas-cular fraction; 3, aqueous fraction containing a small pellet fraction. (Right) Result of the nanofat procedure. 1, Adipose tissue; 2, infiltration fluid.Use of Cavilon for Making Surgical-Site Markings IndelibleSir: Marking of the surgical site is important; especially in plastic surgery. Skin markings are used to design surgical incisions, important landmarks, areas of deepithelialization, and others. Also, markings may be performed in certain positions before the patient is taken on the operating table (e.g., in mammaplasty, the markings are performed with the patient in the erect position).Surgical scrubbing often smudges the preopera-tive markings or can even completely erase them.1 Also, prolonged surgery can expose the markings to body fluids, which can also fade or erase them.Innovative methods of marking the surgical site have been investigated. These may be cumbersome (such as applying henna)2 or can potentially cause hypertrophic scar or keloid (caused by scratching). Various different companies and types of felt-tip pens have also been investigated in an effort to find a more robust ink.3We have assessed the use of Cavilon (3M, Maple-wood, Minn.) to make the markings more indelible. Cavilon is a terpolymer that forms a breathable, trans-parent, protective coating on the skin and results in an acrylate surface that resists removal. It is com-posed of hexamethyldisiloxane (65 to 90%), isooc-tane (5 to 30%), acrylate terpolymer (3 to 12%), and 

   University of GroningenThe Difference between Stromal Vascular Fraction Isolation and Fat Emulsificationvan Dongen, Joris A; Tuin, A Jorien; Harmsen, Martin C; van der Lei, Berend; Stevens,Hieronymus PPublished in:Plastic and Reconstructive SurgeryDOI:10.1097/PRS.0000000000006366IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2020Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):van Dongen, J. A., Tuin, A. J., Harmsen, M. C., van der Lei, B., & Stevens, H. P. (2020). The Differencebetween Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for Centrifugation.Plastic and Reconstructive Surgery, 145(1), 232e-233e. https://doi.org/10.1097/PRS.0000000000006366CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 05-06-2022Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Downloadedfromhttps://journals.lww.com/plasreconsurgbyBhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3mH5nK33R3QitS123Wq8VstcFeB1oKb/CsHQxbf9u49bCjpEi2sa4EA==on01/03/2020Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. 232ePlastic and Reconstructive Surgery • January 2020The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification: A Crucial Role for CentrifugationSir:Stromal vascular fraction is a great breakthrough in regenerative medicine because it improves both scars and wound healing. Therefore, a growing num-ber of mechanical dissociation procedures have been developed that destroy adipocytes and subsequently isolate tissue stromal vascular fraction.1 Most proce-dures are based on shearing of tissue: powerful strok-ing of lipoaspirate through a small channel in a transfer hub to break down adipocytes and reduce volume, and preserving cell-to-cell communication, including extra-cellular matrix.1Since the mid-1990s, a comparable shuffling tech-nique has already been used to emulsify lipoaspirate.2 Emulsification is performed to evenly divide all compo-nents of adipose tissue (i.e., fat and infiltration fluid), Daisuke Mito, M.D.Masakazu Kurita, M.D., Ph.D.Shimpei Miyamoto, M.D., Ph.D.Mutsumi Okazaki, M.D., Ph.D.Department of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo HospitalTokyo, JapanCorrespondence to Dr. MitoDepartment of Plastic, Reconstructive, and Aesthetic SurgeryUniversity of Tokyo Hospital7-3-1, Hongo, BunkyoTokyo 1138655, Japan063m2089@gmail.comDISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. Holm C, Tegeler J, Mayr M, Becker A, Pfeiffer UJ, Mühlbauer W. Monitoring free flaps using laser-induced fluorescence of indocyanine green: A preliminary experience. Microsurgery 2002;22:278–287. 2. Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: A preliminary study. Microsurgery 2009;29:509–514. 3. Unno N, Nishiyama M, Suzuki M, et al. A novel method of measuring human lymphatic pumping using indo-cyanine green fluorescence lymphography. J Vasc Surg. 2010;52:946–952. 4. Landsman ML, Kwant G, Mook GA, Zijlstra WG. Light-absorbing properties, stability, and spectral stabilization of indocyanine green. J Appl Physiol. 1976;40:575–583.resulting in an injectable substance of comparable vol-ume with intact adipocytes. For good clinical under-standing, it is of importance to distinguish between a mechanical isolation or an emulsification procedure. Based on difference in volume reduction between both techniques, the amount of destroyed adipocytes will differ and the amount of oil after centrifugation can simply distinguish between both types of procedures.In the literature, many mechanical isolation pro-cedures have not included a final centrifugation step.1 Therefore, we also hypothesized that some recently described procedures are mentioned as being isolation procedures (e.g., the nanofat procedure) but are actu-ally emulsification procedures.3 In a short experiment, we processed fat (n = 5) by using two different mechani-cal isolation procedures to isolate tissue stromal vascu-lar fraction (e.g., our own developed fractionation of adipose tissue procedure and the nanofat procedure).3,4 Both mechanical isolation procedures were performed as originally described. As a control for both groups, 10 ml of one-time centrifuged adipose tissue was used. The nanofat sample was centrifuged afterward to see whether oil would appear. Furthermore, all samples were formalin-fixed and embedded in paraffin and stained with toluidine blue to visualize the morphology.The fractionation of adipose tissue procedure resulted in 1 ml of aqueous fraction containing a small pellet fraction, 1 ml of stromal vascular fraction and 8 ml of oil (Fig. 1, left). The nanofat procedure resulted in 2 ml of infiltration fluid and 4 to 5 ml of adipose tis-sue, and had no detectable oil fraction (Fig. 1, right). This was corroborated by toluidine blue staining, which showed more stromal fraction and less intact adipocytes in the isolated stromal vascular fraction prepared by means of the fractionation of adipose tissue procedure as compared to stromal vascular fraction isolated by the nanofat procedure and control fat (data not shown).In our hands, virtually no oil appeared with the nanofat procedure, which indicates that this procedure leaves adipocytes intact. We therefore hypothesize that the difference in fluid content caused by difference in pretreatment of the lipoaspirate (i.e., only decantation for the nanofat procedure versus centrifugation for the fractionation of adipose tissue procedure) apparently protects the adipocytes when forced through the single 2.4-mm-hole Luer-to-Luer transfer.Based on our findings, we can conclude that a sim-ple final centrifugation step can determine the amount of oil as evidence of the amount of destroyed fat. In this way, emulsification procedures can easily be distin-guished from isolation procedures. The fractionation of adipose tissue procedure appears to be a mechani-cal dissociation procedure resulting in a small-volume tissue stromal vascular fraction, whereas the nanofat procedure appears to be an emulsification procedure.DOI: 10.1097/PRS.0000000000006366Joris A. van Dongen, B.Sc.Bey Bergman ClinicsThe Hague, The NetherlandsCopyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. Volume 145, Number 1 • Viewpoints233eDepartment of Pathology and Medical Biology Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsA. Jorien Tuin, M.D.Department of Oral and Maxillofacial SurgeryMartin C. Harmsen, Ph.D.Department of Pathology and Medical BiologyBerend van der Lei, M.D., Ph.D.Department of Plastic SurgeryUniversity Medical Center GroningenUniversity of GroningenGroningen, The NetherlandsBey Bergman ClinicsHeerenveen, Zwolle, and Groningen, The NetherlandsHieronymus P. Stevens, M.D., Ph.D.Velthuis KliniekRotterdam, The NetherlandsCorrespondence to Dr. StevensVelthuis Clinic Jan Leentvaarlaan 14-243065 DC Rotterdam, The Netherlandsstevens.hp@gmail.com DISCLOSURENone of the authors has a financial interest in any of the products or devices mentioned in this article.REFERENCES 1. van Dongen JA, Tuin AJ, Spiekman M, Jansma J, van der Lei B, Harmsen MC. Comparison of intraoperative procedures for isolation of clinical grade stromal vascular fraction for regenerative purposes: A systematic review. J Tissue Eng Regen Med. 2018;12:e261–e274. 2. Toledo LS. Syringe liposculpture: A two-year experience. Aes-thetic Plast Surg. 1991;15:321–326. 3. Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: Basic research and clinical applications. Plast Reconstr Surg. 2013;132:1017–1026. 4. van Dongen JA, Stevens HP, Parvizi M, van der Lei B, Harmsen MC. The fractionation of adipose tissue (FAT) procedure to obtain stromal vascular fractions for regenerative purposes. Wound Repair Regen. 2016;24: 994–1003.Fig. 1. (Left) Result of the fractionation of adipose tissue procedure. 1, Oily fraction; 2, stromal vas-cular fraction; 3, aqueous fraction containing a small pellet fraction. (Right) Result of the nanofat procedure. 1, Adipose tissue; 2, infiltration fluid.Use of Cavilon for Making Surgical-Site Markings IndelibleSir: Marking of the surgical site is important; especially in plastic surgery. Skin markings are used to design surgical incisions, important landmarks, areas of deepithelialization, and others. Also, markings may be performed in certain positions before the patient is taken on the operating table (e.g., in mammaplasty, the markings are performed with the patient in the erect position).Surgical scrubbing often smudges the preopera-tive markings or can even completely erase them.1 Also, prolonged surgery can expose the markings to body fluids, which can also fade or erase them.Innovative methods of marking the surgical site have been investigated. These may be cumbersome (such as applying henna)2 or can potentially cause hypertrophic scar or keloid (caused by scratching). Various different companies and types of felt-tip pens have also been investigated in an effort to find a more robust ink.3We have assessed the use of Cavilon (3M, Maple-wood, Minn.) to make the markings more indelible. Cavilon is a terpolymer that forms a breathable, trans-parent, protective coating on the skin and results in an acrylate surface that resists removal. It is com-posed of hexamethyldisiloxane (65 to 90%), isooc-tane (5 to 30%), acrylate terpolymer (3 to 12%), and 

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The Difference between Stromal Vascular Fraction Isolation and Fat Emulsification:A Crucial Role for Centrifugation

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