Reply to "Assessment of Sternal Vascularity With Single Photon Emission Computed Tomography After Harvesting of the Internal Thoracic Artery" by Cohen et al.peer-reviewe

Casha, Aaron

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R E F E R E N C E S1. Cohen AJ, Lockman J, Lorberboym M, Bder O, Cohen N,Medalion B, et al. Assessment of sternal vascularity with singlephoton emission computed tomography after harvesting of theinternal thoracic artery. J Thorac Cardiovasc Surg 1999;118:496-502.2. Brown AH. Assessment of sternal vascularity with single photonemission computed tomography after harvesting of the internalthoracic artery [letter]. J Thorac Cardiovasc Surg 2000;120:616.3. Cohen AJ. Assessment of sternal vascularity with single photonemission computed tomography after harvesting of the internalthoracic artery [letter reply]. J Thorac Cardiovasc Surg2000;120:616.4. Arnold M. The surgical anatomy of sternal blood supply. J ThoracCardiovasc Surg 1972;64:596-610.5. Seyfer AE, Shriver CD, Miller TR, Graeber GM. Sternal bloodflow after median sternotomy and mobilization of the internalmammary arteries. Surgery 1988;104:899-904.6. Rigaud J, Armstrong O, Robert K, Rogez JM, Le Borgne J.Anatomic bases of aorto-coronary bypasses: the internal thoracicartery and blood supply of the sternum. Surg Radiol Anat1998;20:191-5.7. Korbmacher B, Schmitt HH, Bauer G, Hoffman M, Vosberg H,Simic O, et al. Change of sternal perfusion following preparationof the internal thoracic artery—a scintigraphical study. Eur JCardiothorac Surg 2000;17:58-62.8. Schwartz DS, Petrossian E, Brodman RF, Frame R, Schwartz JD,Blitz A, et al. Wound healing after harvesting of the internal tho-racic and the superior and inferior epigastric arteries. Ann ThoracSurg 1994;57:1252-5.9. Pietrasik K, Bakon L, Zdunek P, Wojda-Gradowska U, Dobosz P,Kolesnik A. Clinical anatomy of internal thoracic artery branches.Clin Anat 1999;12:307-14.12/8/113928doi:10.1067/mtc.2001.113928Reply to the Editor:I agree with Casha and Gauci that the reason for lack ofischemia to the ipsilateral internal thoracic artery (ITA) whileharvesting a skeletonized ITA is the avoidance of damage tocollateral vessels. I thank them for citing a reference thatexplains this phenomenon anatomically.1Sternal vascularity after harvesting of the internalthoracic arteryTo the Editor:We read with great interest the article titled, “Assessment ofSternal Vascularity With Single Photon Emission ComputedTomography After Harvesting of the Internal ThoracicArtery”1 and the resulting correspondence.2,3Although anatomic4 and angiographic studies5,6 show par-tial devascularization, studies using bone scans3,7 paint a con-flicting picture with regard to the degree of devascularization.Korbmacher and associates,7 using bone scintigraphy, con-cluded that use of one or both internal thoracic arteries (ITAs)did not cause an increase in healing disturbances as a result ofa postoperatively decreased sternal blood supply. However, adiminution in blood supply may not result in a clinical defi-ciency in wound healing.Because ITA branches can originate as common trunks, poten-tial anastomoses can occur across these joint branches (eg, ster-nal/intercostal) after the ITA is harvested.8 Because the meanlength of the common trunks is 3.0 mm, careful harvest of thecommon trunks close to the ITA may preserve their points of divi-sion, thereby creating a collateral blood supply after ITA mobi-lization.9 This may be the mechanism that would account for thelack of reduction in sternal blood flow noted by Cohen andcoworkers1 when the ITA is skeletonized as opposed to pedicled.We believe that careful harvest of the ITA will preserve these arte-rial channels, so that blood flows from the intercostal arteries tothe intercostal branches of the ITA and then to the points of divi-sion of the common trunks through to the sternal branches of theITA. Thus, blood flow to the sternum occurs through these collat-erals in reverse of the normal anatomic direction. Venous return ishelped by preservation of the internal thoracic veins.Aaron Casha, MDDepartment of Cardiothoracic SurgeryLeeds General InfirmaryLeeds LS2 9PJ, United KingdomMarilyn Gauci, MDDepartment of Anaesthesia and Intensive CareUniversity of Wales College of MedicineCardiff CF14 4XN, United Kingdom1219LETTERS TO THE EDITORThe Editor welcomes submissions for possible publication in the Letters to the Editor sectionthat consist of commentary on an article published in the Journal or other relevant issues. Authorsshould:• Include no more than 500 words of text, three authors, and five references• Type with double-spacing• Submit the letter electronically via the Internet to jtcvs@drexel.edu if possible• For nonelectronic submissions, send a disk and three copies of the disk’s content, a copyrighttransfer letter (see Table of Contents for location) signed by all authors, and a cover letterdescribing any conflicts of interest related to the contents of the letterLetters commenting on an article published in the JTCVS will be considered if they are receivedwithin 6 weeks of the time the article was published. Authors of the article being commented onwill be given an opportunity to offer a timely response (2 weeks) to the letter. Authors of letterswill be notified that the letter has been received. Unpublished letters cannot be returned. on June 4, 2013 jtcs.ctsnetjournals.orgDownloaded from Concerning venous return, since our publication, we haveharvested the ITA with only the accompanying veins in a sep-arate group of patients and have performed scans before andafter the operations. We found no ischemia of the hemister-num in this group, as in the skeletonized group. Therefore, webelieve that preservation of the arterial collaterals is the keyto avoiding hemisternal ischemia after ITA harvest.Preservation of venous return plays a minimal role, if any atall, in sternal ischemia after ITA harvest.Amram J. Cohen, MDDepartment of Cardiovascular SurgeryEdith Wolfson Medical CenterHolon, IsraelR E F E R E N C E1. Pietrasik K, Bakon L, Zdunek P, Wojda-Gradowska U, Dobosz P,Kolesnik A. Clinical anatomy of internal thoracic artery branch-es. Clin Anat 1999;12:307-14.12/8/113929doi:10.1067/mtc.2001.113929Valve-preserving aortic root reconstructionTo the Editor:We read with interest the article by Zehr and associates1 oninitial clinical experience with a new graft for valve-preserv-ing replacement of the ascending aorta. The authors state thatcusp stress “will reduce long-term durability of the valvecusps.” However, this hypothesis is based only on experimen-tal work and is not backed up by clinical observations.Yacoub and colleagues2 reported that the most common causeof surgical revision after valve-preserving replacement of theascending aorta is progressive valve regurgitation. It is uncer-tain whether the new Robicsek-Thubrikar grafts will protectagainst this. The neo-sinuses with the crimping parallel to thelongitudinal axis of the aorta might well dilate even morethan usual.3Furthermore, we believe that case-based, individualizedreconstruction of the sinus of Valsalva with single patches istechnically easier to accomplish. Sinuses 1 to 3 are resectedfirst (it is not always necessary to resect all three). The indi-vidually tailored patches are then sewn in as neo-sinuses.Finally, after reimplantation of the coronary ostia, the newsinotubular junction is created by anastomosis of the recon-structed sinus of Valsalva with the tube graft.Paul P. Urbanski, MD Herz- und Gefäß-KlinikSalzburger Leite 197616 Bad Neustadt, GermanyR E F E R E N C E S1. Zehr KJ, Thubrikar MJ, Gong GG, Headrick JR, Robicsek F.Clinical introduction of a novel prosthesis for valve-preservingaortic root reconstruction for annuloaortic ectasia. J ThoracCardiovasc Surg 2000;120:692-8.2. Yacoub MH, Gehle P, Chandrasekaran V, Birks EJ, Child A,Radley-Smith R. Late results of a valve-preserving operation inpatients with aneurysms of the ascending aorta and root. J ThoracCardiovasc Surg 1998;115:1080-90.3. Franke U, Jurmann MJ, Uthoff K, Kohler A, Jurmann B,Wahlers T, et al. In vivo morphology of woven, collagen-sealedDacron prostheses in the thoracic aorta. Ann Thorac Surg1997;64:1096-8.12/8/113933doi:10.1067/mtc.2001.113933Reply to the Editor:We appreciate the interest in our manuscript1 and the vari-ous points raised in the letter to the Editor by Urbanski.Urbanski points out that the statement that cusp stress “willreduce long-term durability of the valve cusps” is a hypothe-sis based only on experimental work and not backed up byclinical observations. There is little published informationconcerning the mechanism of clinical failure in patients hav-ing undergone a valve-preserving aortic root reconstruction. Iwould further hypothesize that long-term failure has more todo with the quality of the cusps and the initial accuracy of thegeometrical reconstruction concerning cusp coaptation thanthe method of reconstruction. Indeed, successful short-termand long-term results using various reconstructive methodshave been reported.2,3 Harringer and associates4 showed thatpatients with poor geometrical coaptation and greater thantrace aortic insufficiency had a high rate of reoperation. Inour own series using various techniques, reoperation appearsto be related to the need for individual cusp adjustment andamount of regurgitation present after repair. However, there isanecdotal evidence that cusp maceration can occur by contactof the cusp on the Dacron tube. Fig 1 shows the cusp of apatient presenting 17 months after a valve-preserving opera-tion using the reimplantation technique. The cusp had sever-al areas of maceration and a torn free margin.Because of the experimental evidence that the presence ofsinuses does result in less cusp stress, there have been sever-al clinical attempts to recreate sinuses.2,5,6 Leyh and cowork-ers7 have shown that the presence of pseudosinuses as in theremodeling technique results in nearly normal opening andclosing characteristics of the aortic valve. In the evolution ofthe valve-preserving procedure, it makes sense that the nextstep is to recreate the exact anatomy of the aortic root. Webelieve that this sinus graft nearly does so.Urbanski expresses some concern that the bases of thesinuses may splay out over time in this graft, resulting in pro-gressive aortic insufficiency. Long-term results are necessaryto prove or disprove this concern. It is a theoretical possibili-ty. However, the outer purse string of the graft sinuses is incor-porated in the proximal scalloped suture line. This serves tofix the anulus with a crown-shaped annuloplasty stitch thatwill prevent dilatation at the annular and sinus levels. Inpatients with a dilated anulus, an annuloplasty suture and theaddition of an annular fixation strip can be performed. The concept of individual reconstruction of the sinuses ofValsalva with single patches and the addition of a tube graftto a new sinotubular junction is interesting. We could do the1220 Letters to the Editor The Journal of Thoracic andCardiovascular SurgeryJune 2001 on June 4, 2013 jtcs.ctsnetjournals.orgDownloaded from 

Sternal vascularity after harvesting of the internal thoracic artery

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Sternal vascularity after harvesting of the internal thoracic artery

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