Comparison of segmentation software packages for in-hospital 3D print workflow

Purpose: In-hospital three-dimensional (3D) printing of patient-specific pathologies is increasingly being used in daily care. However, the efficiency of the current conversion from image to print is often obstructed due to limitations associated with segmentation software. Therefore, there is a need for comparison of several clinically available tools. A comparative study has been conducted to compare segmentation performance of Philips IntelliSpace Portal(®) (PISP), Mimics Innovation Suite (MIS), and DICOM to PRINT(®) (D2P). Approach: These tools were compared with respect to segmentation time and 3D mesh quality. The dataset consisted of three computed tomography (CT)-scans of acetabular fractures (ACs), three CT-scans of tibia plateau fractures (TPs), and three CTA-scans of abdominal aortic aneurysms (AAAs). Independent-samples [Formula: see text]-tests were performed to compare the measured segmentation times. Furthermore, 3D mesh quality was assessed and compared according to representativeness and usability for the surgeon. Results: Statistically significant differences in segmentation time were found between PISP and MIS with respect to the segmentation of ACs ([Formula: see text]) and AAAs ([Formula: see text]). Furthermore, statistically significant differences in segmentation time were found between PISP and D2P for segmentations of AAAs ([Formula: see text]). There were no statistically significant differences in segmentation time for TPs. The accumulated mesh quality scores were highest for segmentations performed in MIS, followed by D2P. Conclusion: Based on segmentation time and mesh quality, MIS and D2P are capable of enhancing the in-hospital 3D print workflow. However, they should be integrated with the picture archiving and communication system to truly improve the workflow. In addition, these software packages are not open source and additional costs must be incurred

Brown-Séquard Syndrome after Thoracic Endovascular Aortic Repair for a Stanford Type B Aortic Dissection

We present a case of Brown–Séquard syndrome (BSS) after thoracic endovascular aortic repair (TEVAR) to treat Stanford type B aortic dissection. A 49-year-old male presented to the emergency department with acute tearing pain between the scapulae, connected to respiratory movements. Computed tomography showed Stanford type B aortic dissection from the left subclavian artery to the level of the 11th thoracic vertebra. Conservative treatment was initiated with intravenous antihypertensives. However, due to persistent pain and an increase in the aortic diameter with an intramural hematoma, TEVAR was performed. The patient developed symptoms suspicious of spinal cord ischemia postoperatively. A lesion limited to the left-sided spinal cord was observed on magnetic resonance imaging at the level of the 4th to 5th thoracic vertebra. BSS after TEVAR is a rare phenomenon with a fairly good prognosis, depending on the initial injury severity

Heparin immobilization reduces thrombogenicity of small-caliber expanded polytetrafluoroethylene grafts

ObjectiveThe patency of small-diameter expanded polytetrafluoroethylene (ePTFE) grafts for vascular reconstruction is impaired by acute thrombotic occlusion. Prosthetic materials are thrombogenic and cause platelet adhesion and activation of the coagulation cascade. Heparin is a potent anticoagulant drug widely used to prevent and treat thrombosis. A new ePTFE graft with long-term bonding of heparin is now commercially available in several European countries, but a basic analysis of its mechanism of action in humans has never been performed. This study was performed to evaluate the thrombogenicity of heparin-bonded ePTFE grafts compared with standard ePTFE in a newly developed human ex vivo model.MethodsNonanticoagulated blood was drawn from antecubital veins of 10 healthy donors with a 19-gauge needle. The proximal end of a 60-cm ePTFE vascular graft with a diameter of 3 mm was connected to the needle while the distal end was connected to a syringe, which was placed in a syringe pump. Every volunteer served as his or her own control by using a heparin-bonded ePTFE graft on one arm and a standard ePTFE graft on the other arm. The perfusions were performed over 6 minutes with a flow rate of 20 mL/min, corresponding to a shear rate of 74/s. Serial samples were taken at the distal end of the graft for determination of prothrombin fragment 1 + 2, fibrinopeptide A, and P-selectin expression on perfused platelets. Fibrin deposition and platelet deposition were studied by using scanning electronic microscopy.ResultsFibrinopeptide A production over time was significantly reduced on the heparin-bonded ePTFE grafts compared with standard ePTFE grafts (P < .05). There was no increase in the production of prothrombin fragment 1 + 2 or P selectin over time on either type of graft. Scanning electronic microscopy scanning showed platelet deposition and fibrin formation on standard ePTFE grafts, whereas no platelets or fibrin were observed on heparin-bonded ePTFE grafts.ConclusionsHeparin immobilization substantially reduces the thrombogenicity of small-diameter ePTFE in a newly developed human ex vivo model. In this study, we provide evidence that the mechanism of action of the heparin bonding is due not only to anticoagulant but also to antiplatelet effects. Heparin bonding may be an important improvement of ePTFE, resulting in better patency rates for vascular reconstructions.Clinical RelevanceHeparin immobilization reduces the thrombogenicity of small-caliber expanded polytetrafluoroethylene (ePTFE) grafts. The patency of small-diameter ePTFE grafts for vascular reconstruction is impaired by acute thrombotic occlusion. Prosthetic materials are thrombogenic and cause platelet adhesion and activation of the coagulation cascade. Heparin is a potent anticoagulant drug widely used to prevent and treat thrombosis. A new ePTFE graft with long-term bonding of heparin is now commercially available, but a basic analysis of its mechanism of action in humans has never been performed. This study was performed to evaluate the thrombogenicity of heparin-bonded ePTFE grafts compared with standard ePTFE in a newly developed human ex vivo model. We demonstrated that heparin immobilization reduces thrombogenicity on small-caliber ePTFE grafts. Heparin-bonded ePTFE grafts might therefore result in better patency rates for vascular reconstructions with vascular grafts

In vivo cell seeding with anti-CD34 antibodies successfully accelerates endothelialization but stimulates intimal hyperplasia in porcine arteriovenous expanded polytetrafluoroethylene grafts

Background - The patency of AV expanded polytetrafluoroethylene (ePTFE) grafts for hemodialysis is impaired by intimal hyperplasia (IH) at the venous outflow tract. The absence of a functional endothelial monolayer on the prosthetic grafts is an important stimulus for IH. In the present study, we evaluated the feasibility of capturing endothelial progenitor cells in vivo using anti-CD34 antibodies on ePTFE grafts to inhibit IH in porcine AV ePTFE grafts. Methods and Results - In 11 pigs, anti-CD34 - coated ePTFE grafts were implanted between the carotid artery and internal jugular vein. Bare ePTFE grafts were implanted at the contralateral side. After 3 (n = 2) or 28 (n = 9) days, the pigs were terminated, and the AV grafts were excised for histological analysis and SEM. At 3 and 28 days after implantation, 95% and 85% of the coated graft surface was covered by endothelial cells. In contrast, no cell coverage was observed in the bare graft at 3 days, whereas at 28 days, bare grafts were partly covered with endothelial cells (32%; P = 0.04). Twenty-eight days after implantation, IH at the venous anastomosis was strongly increased in anti-CD34 - coated grafts (5.96 +/- 1.9 mm(2)) compared with bare grafts (1.70 +/- 0.4 mm(2); P = 0.03). This increase in IH coincided with enhanced cellular proliferation at the venous anastomosis. Conclusions - Autoseeding with anti-CD34 antibodies results in rapid endothelialization within 72 hours. Despite persistent endothelial graft coverage, IH at the outflow tract is increased profoundly at 4 weeks after implantation. Further modifications are required to stimulate the protective effects of trapped endothelial cell

Histological evaluation of the aortic wall response following endovascular aneurysm repair and endovascular aneurysm sealing

Objective: The Nellix endovascular aneurysm sealing (EVAS) system was developed as an alternative to conventional endovascular aneurysm repair (EVAR) to minimize endoleaks. A significantly higher failure rate of EVAS may be related to an interaction between the filled endobags and the AAA wall. In general, biological information on aortic remodeling after traditional EVAR is scarce. In this light, we provide here the first histologic evaluation of aneurysm wall morphology after EVAR and EVAS. Methods: Fourteen histological human wall samples of EVAS and EVAR explantation were systematically analysed. Primary open aorta repair samples were included as reference. Results: Compared with primary open aortic repair samples, endovascular repair aortic samples were characterized by more pronounced fibrosis, a greater number of ganglionic structures, decreased cellular inflammation, less calcification, and a lower atherosclerotic load. EVAS was specifically associated with the presence of unstructured elastin deposits. Conclusions: The biological response of the aortic wall after endovascular repair resembles the maturation process of a scar rather than a bona fide healing response. Moreover, the inflammatory response in the aortic wall after placement of endovascular protheses is less prominent than after primary open repair. A specific post-EVAS aortic wall characteristic was unstructured elastin fragments

Active aortic aneurysm sac treatment with shape memory polymer during endovascular aneurysm repair

Preprocedural image analysis and intraprocedural techniques to fully treat infrarenal abdominal aortic aneurysm sacs outside of the endograft with shape memory polymer (SMP) devices during endovascular aneurysm repair were developed. Prospective, multicenter, single-arm studies were performed. SMP is a porous, self-expanding polyurethane polymer material. Target lumen volumes (aortic flow lumen volume minus endograft volume) were estimated from the preprocedural imaging studies and endograft dimensions. SMP was delivered immediately after endograft deployment via a 6F sheath jailed in a bowed position in the sac. Technical success was achieved in all cases, defined as implanting enough fully expanded SMP volume to treat the actual target lumen volume

Solitary iliac branch endoprosthesis placement for iliac artery aneurysms

Background: Isolated iliac artery aneurysms (IAAs), accounting for 2% to 7% of all abdominal aneurysms, are often treated with the use of iliac branched endografts. Although outside the manufacturer’s instructions for use, iliac branched devices can be used solely, without the adjunctive placement of an endovascular aneurysm repair device, for the treatment of an isolated IAA. In the present study, we have described the outcomes of the use of the Gore iliac branched endoprosthesis (IBE; W.L. Gore & Associates, Flagstaff, Ariz), without the support of an infrarenal endovascular aneurysm repair device, for the exclusion of an isolated IAA. The present study was an international multicenter retrospective cohort analysis. Methods: All the patients who had undergone treatment with a solitary IBE for IAA exclusion from January 11, 2013 to December 31, 2018 were retrospectively reviewed. The primary outcome was technical success. The secondary outcomes included mortality, intraoperative and postoperative complications, and reintervention. Results: A total of 18 European and American centers participated, with a total of 51 patients in whom 54 IAAs were excluded. The technical success rate was 94.1%, with an assisted technical success rate of 96.1%. No 30-day mortality occurred, with 98.1% patency of the internal and external iliac artery found at 24 months of follow-up. At 24 months of follow-up, 81.5% of the patients were free of complications and 90% were free of a secondary intervention. Conclusions: Treatment with a solitary IBE is a safe and, at midterm, an effective treatment strategy for selected patients with a solitary IAA. (J Vasc Surg 2022;75:1268-75.