Autologous Vein Research Articles

Nanomedicine-based strategies for the treatment of vein graft disease.

Autologous saphenous veins are the most frequently used conduits for coronary and peripheral artery bypass grafting. However, vein graft failure rates of 40-50% within 10 years of the implantation lead to poor long-term outcomes after bypass surgery. Currently, only a few therapeutic approaches for vein graft disease have been successfully translated into clinical practice. Building on the past two decades of advanced understanding of vein graft biology and the pathophysiological mechanisms underlying vein graft disease, nanomedicine-based strategies offer promising opportunities to address this important unmet clinical need. In this Review, we provide deep insight into the latest developments in the rational design and applications of nanoparticles that have the potential to target specific cells during various pathophysiological stages of vein graft disease, including early endothelial dysfunction, intermediate intimal hyperplasia and late-stage accelerated atherosclerosis. Additionally, we underscore the convergence of nanofabricated biomaterials, with a particular focus on hydrogels, external graft support devices and cell-based therapies, alongside bypass surgery to improve local delivery efficiency and therapeutic efficacy. Finally, we provide a specific discussion on the considerations, challenges and novel perspectives for the future clinical translation of nanomedicine for the treatment of vein graft disease.

Comparative outcomes between cryopreserved cadaveric saphenous vein and spliced autogenous vein for infrainguinal bypass

Objective Cryopreserved greater saphenous vein (CV) and spliced autogenous veins (SV) serve as alternative conduits for lower extremity revascularization when a single-segment autogenous saphenous vein is not available. This study compares the outcomes of infrainguinal bypasses using CV and two-segment SV as conduits. Methods We conducted a retrospective review of data on all lower extremity bypasses performed using CV or SV at our institution. Patients undergoing revascularization for atherosclerotic occlusive disease were included in the statistical analysis, while those with primary acute embolic and/or traumatic causes were excluded. Primary outcomes included limb loss. Secondary outcomes included primary, primary assisted, and secondary patency at one and 3 years. Results 56 patients were included in the analysis, 25 had CV bypass and 31 had SV. The groups did not significantly differ in demographics and comorbidities except for age (mean age 68 CV vs 62 SV, p = .03), and prior coronary artery bypass graft (32% CV vs 6.5% SV, p = .01). There was no statistically significant difference between CV and SV at one- and three-years in limb salvage (54.4% CV vs 61.7% SV, p = .96 and 48.3% CV vs 50.2% SV, p = .94), and bypass abandonment (44.2% CV vs 61.7% SV, p = .83 and 44.2% CV vs 44% SV, p = .85). Despite lower one and 3-year primary patency for CV compared to SV (33.3% CV vs 54.9% SV, p = .29, and 27.7% CV vs 48% SV, p = .27), the difference was statistically not significant. CV and SV had also similar one and 3-year primary assisted (41.8% CV vs 57.8% SV, p = .72 and 41.8% CV vs 44.9% SV, p = .71), and secondary patency (43.9% CV vs 61.7% SV, p = .8 and 43.9% CV vs 44% SV, p = .88), with no statistically significant difference. Conclusion In patients for whom single-segment autologous saphenous vein bypass is not an option, CV and SV show comparable limb salvage up to 3 years. SV may be a more durable option with higher patency, this was however not statistically significant in our cohort likely due to sample size.

Platelet Membrane-Encapsulated Poly(lactic-co-glycolic acid) Nanoparticles Loaded with Sildenafil for Targeted Therapy of Vein Graft Intimal Hyperplasia

Autologous vein grafts have attracted widespread attention for their high transplantation success rate and low risk of immune rejection. However, this technique is limited by the postoperative neointimal hyperplasia, recurrent stenosis and vein graft occlusion. Hence, we propose the platelet membrane-coated Poly(lactic-co-glycolic acid) (PLGA) containing sildenafil (PPS). Platelet membrane (PM) is characterised by actively targeting damaged blood vessels. The PPS can effectively target the vein grafts and then slowly release sildenafil to treat intimal hyperplasia in the vein grafts, thereby preventing the progression of vein graft restenosis. PPS effectively inhibits the proliferation and migration of vascular smooth muscle cell (VSMCs) and promotes the migration and vascularisation of human umbilical vein endothelial cells (HUVECs). In a New Zealand rabbit model of intimal hyperplasia in vein grafts, the PPS significantly suppressed vascular stenosis and intimal hyperplasia at 14 and 28 days after surgery. Thus, PPS represents a nanomedicine with therapeutic potential for treating intimal hyperplasia of vein grafts.

Long-Term Outcomes of Vein Adjuncts in Distal Infrainguinal Bypass

IntroductionAutologous vein is recommended for infrainguinal bypass due to improved freedom from occlusion compared to prosthetic graft. In patients without adequate vein, vein adjunct at the distal anastomosis has been suggested to improve patency in small studies. This study aimed to determine if performance of a distal vein adjunct was associated with improved freedom from occlusion in below knee popliteal and tibial bypasses compared to prosthetic bypass alone. MethodsA retrospective review of the Vascular Quality Initiative Infrainguinal Bypass database was conducted. Patients undergoing prosthetic-only and prosthetic with vein adjunct were compared. Inclusion criteria included age >18 years, and bypass to below knee popliteal or tibial vessels. Exclusion criteria included autologous vein conduits and prior interventions. Groups were further divided into below knee popliteal and tibial subgroups. ResultsA cohort of 3,939 patients underwent bypass to the below knee popliteal artery, with 287 (7.3%) receiving vein adjunct. More patients were male (68.8 vs 57.8%, p<.001) and had higher rates of CHF (21.1 vs 16.0%, p=.040) within the below knee popliteal group. Two-year bypass occlusion was decreased in patients receiving vein adjuncts (11.6 vs 17.1%, p=.004). A cohort of 2,378 patients underwent tibial bypass, with 473 (19.9%) receiving vein adjunct. Within the tibial group, patients were similar in age, BMI, race, comorbidities, and indications. Bypass occlusion (24.8 vs. 17.6%, p=.005) and amputation (20.5 vs. 15.9%, p=.048) rates at two years were worse for patients who did not receive a distal vein adjuncts to tibial arteries. ConclusionDistal vein adjuncts are associated with improved freedom from occlusion, amputation, MALEs, and overall survival when compared to bypasses performed with prosthetic graft alone for tibial bypasses within the VQI. Vein adjunct was not associated with improved freedom from occlusion in below knee popliteal bypasses. Consideration should be given to utilization of a distal vein adjunct to improve prosthetic bypass longevity and limb salvage for patients requiring tibial bypasses.

Hybrid interventions on distal sections of the main arteries in extended chronic occlusions of the superficial femoral artery in patients with critical limb ischemia

AbstractBackground. Over two thirds of patients with CLI present with SFA disease, often a long CTOwith patent proximal popliteal artery and extensive occlusive lesions in the crural vessels. Westudied a series of hybrid interventions to treat this multilevel disease as an alternative to conventionalapproach.Aim. To improve the results of revascularization of the lower limb in cases of extended occlusionof the SFA in combination with crural runoff.Materials and Methods: A total of 40 patients (25% women; mean age 69.5 years), all with Rutherfordclass 5-6 disease, were included in the study. Angiography showed long (&gt;200 mm) SFA CTOin all cases (100%) accompanied by CTO of distal popliteal artery (n=9; 22.5%); all crural arteries(n=26; 65%) or all crural arteries but the peroneal (n=7; 17.5%).We performed femoropopliteal bypass with autologous vein in all patients (100%) followed byballoon angioplasty of distal popliteal and/or crural arteries done either on the same day (n=22;55%) or 2-14 days later (n=18; 45%). Direct angiosomic revascularization was achieved in 36 patients(90%).We used a series of 46 consecutive patients who underwent femoral tibial bypass as historic control.Results. The 30-day mortality and graft failure rate were 2.5% vs 4.3% (p&gt;0.05) and 5% vs 13%(p&lt;0.05) after hybrid and tibial bypass interventions, respectively.At 1 year the primary patency of bypass and amputation-free survival were 77.7% (95% CI 61.7-93.7) vs 57.1% (95% CI 42.9-71.3) and 82.1% (95% CI 66.8-97.4) vs 69.6% (95% CI 56.1-83.1) afterhybrid intervention and tibial bypass, respectively (all non-significant).Conclusions. Compared to femoral tibial bypass, a hybrid intervention comprised of a bypass to apatent popliteal artery and subsequent crural angioplasty decreased the early failure rate withoutany negative effect on the long-term outcomes in CLI patients with long SFA CTO and extensiverunoff disease.

Biological conduits based on spider silk for reconstruction of extended nerve defects.

The availability of appropriate conduits remains an obstacle for successful reconstruction of long-distance nerve defects. In previous sheep trials, we were able to bridge 6 cm nerve gaps with nerve conduits based on spider silk fibers with full functional outcomes. Here, we describe the first application of spider silk for nerve repair inhumans. Four patients with extended nerve defects (>20 cm) underwent nerve reconstruction by interposition of conduits that were composed of spider silk fibers contained in autologous veins. The longitudinal luminal fibers (approx.2500 fibers per graft) consisted of drag line silkfrom Trichonephila spiders. All patients were evaluated between 2and 10 years postreconstruction, clinically, and byneurography. In all patients, primary wound healing and no adverse reactions to the implanted spider silk material wereobserved. Patients regained the following relevant functions: protective sensibility, full flexor function with near-normal grasp and powerful function after microvascular gracilis muscle transfer, and key grip function and gross finger flexion after additional tenodesis. One patient with sciatic nerve reconstruction developed protective sensibility of the lower leg, foot, and gait, enabling normal walking and jogging. No neuroma formation or neuropathic or chronic pain occurred in any of the patients. For patients with extended peripheral nerve defects in the extremities, use of conduits based on spider silk fibers offers the possibility of restoring sensory function and protection from neuroma. This kind of nerve bridges provides new perspectives for the reconstruction of complex and long-distance nerve defects.

Long-term outcomes of below-the-knee bypass surgery using heparin-bonded expanded polytetrafluoroethylene grafts.

To report the outcomes of below-the-knee (BK) bypass surgery using heparin-bonded expanded polytetrafluoroethylene (ePTFE) grafts, performed in two centers since its launch in Japan. We conducted a retrospective analysis of databases from two medical centers, evaluating 51 limbs in 42 consecutive patients with peripheral arterial disease (PAD), who underwent BK bypass surgery using heparin-bonded ePTFE grafts between October, 2013 and April, 2023. Thirty-three limbs (64.7%) were classified as Rutherford category 4-6 and 33 limbs (64.7%) had a history of ipsilateral revascularization. Technical success was achieved in 98% of the patients. The 30day mortality rate was 2.4% (n = 1) and the overall 30day complication rate was 9.5% (n = 4). The median follow-up period was 38 (interquartile range 13-67) months. Three patients required major amputation and 14 died during follow-up. Primary patency rates at 1, 3, and 5years were 67.8%, 57.5%, and 46.5%, respectively, while secondary patency rates for these periods were 84.6%, 70.0%, and 66.0%, respectively. Overall survival rates at 1, 3, and 5years were 90.1%, 74.5%, and 70.9%, respectively. BK bypass surgery using heparin-bonded ePTFE graft is a viable and durable option for patients with PAD, who are deemed unsuitable for autologous vein bypass surgery.

Photosealed Neurorrhaphy Using Autologous Tissue.

Photochemical sealing of a nerve wrap over the repair site isolates and optimizes the regenerating nerve microenvironment. To facilitate clinical adoption of the technology, we investigated photosealed autologous tissue in a rodent sciatic nerve transection and repair model. Rats underwent transection of the sciatic nerve with repair performed in three groups: standard microsurgical neurorrhaphy (SN) and photochemical sealing with a crosslinked human amnion (xHAM) or autologous vein. Functional recovery was assessed at four-week intervals using footprint analysis. Gastrocnemius muscle mass preservation, histology, and nerve histomorphometry were evaluated at 120 days. Nerves treated with a PTB-sealed autologous vein improved functional recovery at 120 days although the comparison between groups was not significantly different (SN: -58.4 +/- 10.9; XHAM: -57.9 +/- 8.7; Vein: -52.4 +/- 17.1). Good muscle mass preservation was observed in all groups, with no statistical differences between groups (SN: 69 +/- 7%; XHAM: 70 +/- 7%; Vein: 70 +/- 7%). Histomorphometry showed good axonal regeneration in all repair techniques. These results demonstrate that peripheral nerve repair using photosealed autologous veins produced regeneration at least equivalent to current gold-standard microsurgery. The use of autologous veins removes costs and foreign body concerns and would be readily available during surgery. This study illustrates a new repair method that could restore normal endoneurial homeostasis with minimal trauma following severe nerve injury.

Comparative outcomes of arterial bypass using the human acellular vessel and great saphenous vein in patients with chronic limb ischemia

ObjectiveThe Human Acellular Vessel (HAV) is a novel, off-the-shelf biologic conduit being evaluated for arterial reconstructions. Regulatory studies in peripheral arterial disease (PAD) to date have consisted of single-arm cohorts with no comparator groups to contrast performance against established standards. This study aimed to compare outcomes of the HAV with autologous great saphenous vein (GSV) in patients with advanced PAD undergoing infrageniculate bypass. MethodsPatients with advanced PAD and no autologous conduit who underwent bypass with the 6-mm diameter HAV (Group 1; n = 34) (March 2021-February 2024) were compared with a multicenter historical cohort who had bypass with single-segment GSV (group 2; n = 88) (January 2017-December 2022). The HAV was used under an Investigational New Drug protocol issued by the Food and Drug Administration (FDA) under the agency's Expanded Access Program. ResultsDemographics were comparable between groups (mean age 69 ± 10 years; 71% male). Group 1 had higher rates of tobacco use (37 pack-years vs 28 pack-years; P = .059), coronary artery disease (71% vs 43%; P = .007), and prior coronary artery bypass grafting (38% vs 14%; P = .003). Group 1 had more patients classified as wound, ischemia, and foot infection clinical stage 4 (56% vs 33%; P = .018) and with previous index leg revascularizations (97% vs 53%; P < .001). Both groups had a similar number of patients with chronic limb-threatening ischemia (Rutherford class 4-6) (88% vs 86%; P = .693) and Global Anatomic Staging System stage III (91% vs 96%; P = .346). Group 1 required a composite conduit (two HAV sewn together) in 85% of bypasses. The tibial vessels were the target in 79% of group 1 and 100% of group 2 (P < .001). Group 1 had a lower mean operative time (364 minutes vs 464 minutes; P < .001). At a median of 12 months, major amputation-free survival (73% vs 81%; P = .55) and overall survival (84% vs 88%; P = .20) were comparable. Group 1 had lower rates of primary patency (36% vs 50%; P = .044), primary-assisted patency (45% vs 72%; P = .002), and secondary patency (64% vs 72%; P = .003) compared with group 2. ConclusionsImplanted under Food and Drug Administration Expanded Access provisions, the HAV was more likely to be used in redo operations and cases with more advanced limb ischemia than GSV. Despite modest primary patency, the HAV demonstrated resilience in a complex cohort with no autologous conduit options, achieving good secondary patency and providing major amputation-free survival comparable with GSV at 12 months.

Learning curve in tibial and pedal bypass with autologous vein graft.

The 2019 Global Vascular Guidelines recommended open bypass for patients at average risk with greater limb severity and anatomical complexity. However, the outcomes of tibial and pedal bypass (TPB) are inferior to those of above-the-knee surgical revascularization. This may be due to the technical difficulty and need for development of skills to perform TPB. However, there is a limited knowledge on the learning curve in TPB. Thus, the aim of the study is to assess this learning curve in a single-center retrospective analysis. Cases treated with TPB with an autologous vein conduit in patients with chronic limb-threatening ischemia (CLTI) at a Japanese single center from 2009 to 2022 were analyzed retrospectively. The primary endpoint was the learning curve for TPB. The study included 449 TPB procedures conducted by a single main surgeon in patients with CLTI (median age, 75 years; 309 males; diabetes mellitus, 73%; end stage renal failure with hemodialysis, 44%). The operative time decreased significantly as the number of cases accumulated (p < .001). Using the cumulative sum (CUSUM) operative time, the learning curve was estimated to be phase 1 (initial learning curve) for 134 cases (1-134); phase 2 (competent period) for 179 cases (135-313); and phase 3 (mastery and challenging period) for 136 cases (314-449). The mean follow-up period was 34 ± 31months. The 1- and 3-year limb salvage rates of 97% and 96% in phase 3 were significantly higher than those in phases 1 and 2 (p < .001, p = .029). Major adverse limb events (MALE) occurred in 117 (26%) patients, and the 1- and 3-year MALE rates of 10% and 17% in phase 3 were significantly lower than those in phases 1 and 2 (p < .001, p = .009). In the study, vascular surgeon required a learning curve of 134 TPB cases to Overcoming the learning curve for bypass was associated with improvement of medium-term outcomes for limb salvage and freedom from MALE.

External Support of Autologous Internal Jugular Vein Grafts with FRAME Mesh in a Porcine Carotid Artery Model.

Autologous vein grafts are widely used for bypass procedures in cardiovascular surgery. However, these grafts are susceptible to failure due to vein graft disease. Our study aimed to evaluate the impact of the latest-generation FRAME external support on vein graft remodeling in a preclinical model. We performed autologous internal jugular vein interposition grafting in porcine carotid arteries for one month. Four grafts were supported with a FRAME mesh, while seven unsupported grafts served as controls. The conduits were examined through flowmetry, angiography, macroscopy, and microscopy. The one-month patency rate of FRAME-supported grafts was 100% (4/4), whereas that of unsupported controls was 43% (3/7, Log-rank p = 0.071). On explant angiography, FRAME grafts exhibited significantly more areas with no or mild stenosis (9/12) compared to control grafts (3/21, p = 0.0009). Blood flow at explantation was higher in the FRAME grafts (145 ± 51 mL/min) than in the controls (46 ± 85 mL/min, p = 0.066). Area and thickness of neo-intimal hyperplasia (NIH) at proximal anastomoses were similar for the FRAME and the control groups: 5.79 ± 1.38 versus 6.94 ± 1.10 mm2, respectively (p = 0.558) and 480 ± 95 vs. 587 ± 52 μm2/μm, respectively (p = 0.401). However, in the midgraft portions, the NIH area and thickness were significantly lower in the FRAME group than in the control group: 3.73 ± 0.64 vs. 6.27 ± 0.64 mm2, respectively (p = 0.022) and 258 ± 49 vs. 518 ± 36 μm2/μm, respectively (p = 0.0002). In our porcine model, the external mesh FRAME improved the patency of vein-to-carotid artery grafts and protected them from stenosis, particularly in the mid regions. The midgraft neo-intimal hyperplasia was two-fold thinner in the meshed grafts than in the controls.

Autologous vein graft in living donor kidney transplant (case report)

Renal transplantation is the preferred treatment for end-stage renal disease, with vascular complications being a significant cause of graft dysfunction. Although many surgical methods are used to ensure the most effective possible vascular anastomosis, autologous saphenous vein grafting remains a less explored approach to renal transplantation. Chronic kidney disease often presents with complications related to impaired renal perfusion, necessitating interventions to improve blood flow to the kidneys. Herein, we present a case report detailing the utilization of autologous saphenous grafting to establish an anastomosis between the renal vein and external iliac vein in a patient with сhronic kidney disease with maintenance hemodialysis twice a week. This case report indicates the potential and prospective advantages of using autologous saphenous grafting for intricate renal vein reconstructions in patients with chronic kidney disease.

Long-term outcomes of autologous vein bypass for repair of upper and lower extremity major arterial trauma: Presented at Society for Clinical Vascular Surgery, 48th Annual Symposium, Miami, Florida, March 13-17, 2021.

Long-term outcomes of autologous vein bypass for repair of upper and lower extremity major arterial trauma: Presented at Society for Clinical Vascular Surgery, 48th Annual Symposium, Miami, Florida, March 13-17, 2021.

Protein-based tissue adhesive reduces time to haemostasis in peripheral vascular surgery.

The aim of this study was to evaluate the effectiveness of protein-based tissue adhesive (Bioglue®) in reducing time to haemostasis in patients undergoing peripheral vascular surgery. From January to December 2021, 100 consecutive patients from 4 centres have been treated with open peripheral vascular surgery including upper and lower limb interventions. Patients have been allocated in each centre into control with no use of Bioglue® (Group no-Bio, 50 patients) or use of Bioglue® (Group Bio, 50 patients) by a block randomization method 10:10 until the required sample size was reached. Perioperative parameters including time to haemostasis, number of adjunctive stitches, and in-hospital bleeding have been analysed and compared in the two groups by means of mean independent-samples tT -test and Gehan-Breslow-Wilcoxon test. Both groups were homogeneous in terms of demographic data, preoperative risk factors, and preoperative medical therapy except for a higher percentage of active smokers in Group Bio (52% vs. 24%, p = 0.004). Femoral endarterectomy was most common in Group Bio (44% vs. 24%, p = 0.03), whilst the percentage of lower limb vein bypasses was higher in Group no-Bio (50% vs. 36%, p = 0.03). Bovine pericardium was the preferred material in Group Bio (20 cases, 40%), whilst autologous vein is mostly used in Group no-Bio (26 cases, 52%) (p = 0.01). Time to haemostasis was faster in Group Bio (4.4 vs. 9.6 minutes, p < 0.001). The need for adjunctive stitches was higher in Group no-Bio (8 cases, 16%, Group Bio vs. 25 cases, 50%, Group no-Bio; p < 0.001). The overall rate of in-hospital bleeding, including those requiring reintervention, was not different between the two groups (9 cases, 18%, Group Bio vs. 7 cases, 14%, Group no-Bio; p = 0.39). The protein-based tissue adhesive Bioglue® reduced time to haemostasis and need for adjunctive stitches in peripheral vascular surgery. However, it did not affect the overall rate of perioperative bleedings. Further studies with larger sample sizes are needed to validate these outcomes.

#865 Autologous cephalic vein transposition in the placement of forearm arteriovenous fistulas

Abstract Background and Aims The autologous vein transposition was commonly used for hemodialysis vascular access (VA) in selected patient. The saphenous vein was used as a vascular graft; while, the contralateral cephalic vein was used as a bridge. We describe a new technique of autologous cephalic vein transposition to create a native AVF in hemodialysis patients. Method Patients referred to our hospital for a vascular access placement. US vascular mapping of upper extremities revealed small arteries, but adequate forearm veins in all patients. Specifically, the radial artery luminal diameter was &amp;lt; 1.4 mm and &amp;lt; 1.6 mm, respectively at wrist and at middle-arm. While, at bend of the elbow, the ulnar artery diameter (&amp;gt;2.5 mm) in one case, and the brachial artery diameter (&amp;gt;3.5 mm) in two cases, were deemed adequate as feeding arteries of a possible AVFs. Furthermore, the diameter of the forearm cephalic vein ranged from 2.0 to 2.4 mm; in the upper arm the veins were obstructed or stenotic in one of the two arms. The basilic vein was patent in both arms of the patients; the internal diameter varied from 2.5 to 2.7 mm. Due to difficulty to create a traditional fistula, and higher risk of primary failure, it was decided to transpose the cephalic vein, from the forearm not suitable for the AVF, to the contralateral arm chosen for the AVF placement. Results With local anesthesia, an approximately 10-cm stretch of cephalic vein was harvested from the arm contralateral to the site chosen for AVF. Then, the transposed veins, reversed in their cranio-caudal position, were tunneled subcutaneously and anastomosed, in an end-to-end fashion, with cephalic vein at wrist region, and subsequently in a side-artery to end-vein at the elbow crease. The transposed AVFs were created in three patients with ESKD (2M/1F), mean age 47± 3.6 years, (two in the non-dominant arm), without complications. After 4 weeks, all the AVF were patent and the access flow was 660±120 ml/min. All the three AVF was deemed mature and usable for hemodialysis. Conclusion In selected cases, autologous transposition of the cephalic vein can be used to create an AVF, providing a long segment for cannulation. This type of AVF can be an alternative to prosthetic fistula, sparing the central venous catheter.

Outcomes of Visceral Arterial Interposition Graft Reconstruction for Locally Advanced Pancreatic Cancer.

The aim of this study is to determine perioperative outcomes and the patency of interposition conduits for visceral arterial reconstruction in this setting. Visceral arterial encasement in locally advanced pancreatic cancer was historically a contraindication for surgery. With modern effective neoadjuvant strategies, our recent experience has made advanced vascular resection and reconstruction feasible in selected patients. A retrospective review was performed of patients undergoing pancreatic tumor resection with en bloc arterial resection and interposition revascularization between 6/2002-10/2022. Endpoints included graft patency, vascular-related complications, reinterventions, morbidity, and mortality. Visceral arterial reconstruction with interposition grafting was performed in 111 patients undergoing en bloc arterial resections for pancreatic cancer. Graft types included autologous arterial conduits (n=66, 58 superficial femoral artery (SFA) and 8 splenic artery), cryopreserved arterial allografts (n=24), autologous saphenous veins (n=12), synthetic conduits (n=8), and composite autologous artery and synthetic (n=1). Perioperative 90-day mortality decreased significantly over time to 5% in the last six years. Vascular complications related to arterial reconstruction occurred in 11% (n=12) and included pseudoaneurysm (n=6), graft thrombus (n=2), stenosis requiring reintervention (n=2), hepatic failure (n=1), and hepatic and intestinal ischemia (n=1). Nine (8%) patients underwent vascular-related reinterventions. After median follow-up of 17-months, primary patency was 81% for the entire cohort and was highest in the SFA group (95%). The donor limb/harvest site complication rate was 8% with 100% primary patency. Visceral arterial resection with interposition reconstruction for locally advanced pancreatic cancer can be performed with acceptable vascular morbidity and durable patency. Autologous SFA was the most suitable conduit for reconstructions in our experience, with highest primary patency.

Defining the miRnome of Saphenous Vein Smooth Muscle Cells from Patients with Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) patients suffer premature development of cardiovascular disease and commonly require cardiac revascularization using the autologous saphenous vein (SV). Smooth muscle cells (SMCs) are the principal cell type within the vascular wall and are dysfunctional in T2DM SV-SMCs, yet the mechanisms underpinning this are incompletely understood. The purpose of this study was to interrogate differential microRNA (miRNA) expression in SV-SMCs to enhance our understanding of T2DM SV-SMC phenotypic change. miRNA expression in primary human SV-SMCs from T2DM and non-diabetic (ND) donors was determined using an array (n = 6 each of ND and T2DM SV-SMCs). Differentially expressed miRNAs were ranked, and functional annotation of the 30 most differentially expressed miRNAs using DAVID and KEGG analysis revealed pathways related to SMC phenotype, including proliferation, migration, cytokine production and cell signaling. After selecting miRNAs known to be involved in SMC phenotypic regulation, miR-17, miR-29b-2, miR-31, miR-130b and miR-491 were further validated using qRT-PCR (n = 5 each of ND and T2DM SV-SMC), with miR-29b-2 subsequently being removed from further investigation. Potential mRNA targets were identified using mirDIP. Predicted target analysis highlighted likely dysregulation in transcription, epigenetic regulation, cell survival, intracellular signaling and cytoskeletal regulation, all of which are known to be dysfunctional in T2DM SV-SMCs. In conclusion, this paper identified four miRNAs that are dysregulated in T2DM SV-SMCs and are implicated in functional changes in the behavior of these cells. This provides a step forward in our understanding of the molecular and epigenetic regulation of vascular dysfunction in T2DM.

Alternative vein bypass in octogenarians with chronic limb-threatening ischaemia.

Octogenarians are regarded as one of the frailest patient groups among the chronic limb-threatening ischaemia population with high perioperative morbidity and mortality rates. As a result, alternative vein bypass surgery in the absence of sufficient great saphenous vein is often not considered as a potential treatment option. The aim of this study was to compare the results of octogenarians undergoing alternative vein bypass surgery due to chronic limb-threatening ischaemia to younger patients. A single-centre retrospective analysis of patients undergoing bypass surgery for chronic limb-threatening ischaemia with alternative autologous vein grafts between 1997 and 2018 was performed. Patients aged over 80 years were compared with those under 80 years. Graft patency rates were assessed and a risk factor analysis for limb loss was performed. In total, 592 patients underwent bypass surgery during the study interval. Twenty-one per cent (n = 126) of patients were 80 years or older. At 4 years, primary, primary-assisted and secondary patency as well as limb salvage rates were not significantly different between the two groups (46% versus 50%, 60% versus 66%, 69% versus 72%, 72% versus 77%, for octogenarians versus non-octogenarians respectively). Major amputations were performed in 27 (21%) octogenarians and 91 (20%) non-octogenarians (P = 0.190). No higher 30-day and long-term mortality rates nor morbidity rates were detected in the octogenarian group with a median follow-up time of 27 (interquartile range 12-56) months. Minor amputation, the reason for alternative vein grafts, as well as the profunda femoris artery as proximal origin of the bypass were risk factors for limb loss in the postoperative course. Alternative vein bypass surgery in octogenarians with chronic limb-threatening ischaemia is safe and effective in terms of patency rates, limb salvage and survival compared with younger patients in the absence of sufficient great saphenous vein. Age alone should not be a deterrent from performing bypass surgery.

Comparison of Contralateral vs Ipsilateral Vein Graft for Traumatic Vascular Injury Repair: A Cohort From PROOVIT.

Traumatic injury leading to arterial damage has traditionally been repaired using autologous vein graft from the contralateral limb. This often requires a secondary surgical site and the potential of prolonged operative time for patients. We sought to assess the use of ipsilateral vs contralateral vein grafts in patients who experienced traumatic extremity vascular injury. A multicenter database was queried to identify arterial injuries requiring operative intervention with vein grafting. The primary outcome of interest was need for operative reintervention. Secondary outcomes included risk of thrombosis, infection, and intensive care unit length of stay. 358 patients (320 contralateral and 38 ipsilateral) were included in the analysis. The ipsilateral vein cohort did not display a statistically significant decrease in need for reoperation when compared to the contralateral group (11% vs 23%; OR 0.41, 95% CI -0.07-1.3; P = .14). Contralateral repair was associated with longer median intensive care unit (ICU) LOS (4.3 vs 3.1days; P < .01).

Popliteal-to-Distal Extreme Bypass in Endovascular Era

ObjectivesChronic limb-threatening ischemia (CLTI) is characterized by rest pain and tissue loss, with an annual mortality rate of 20% and amputation rate of 40%, if not treated. Open bypass surgery is recommended in CLTI, depending on the availability of good quality venous material, outflow artery patency and surgical expertise. Aim of the study is to analyze primary patency, limb salvage and survival rate in patient undergoing popliteal-to-distal bypass. MethodsAll consecutive patients who underwent popliteal-to-distal bypass surgery between January 2016 and December 2021 were enrolled in the study. Primary outcomes were primary patency, limb salvage and overall survival. Secondary outcomes included amputation-free survival and secondary patency. ResultsForty-nine patients were included during the study. Technical success was achieved in 100% of cases. Target outflow artery was in 27% (n. 13) of cases the anterior tibial artery in 27% (n. 13) dorsalis pedis, in 2% (n. 1) the peroneal artery, in 30% (n. 15) the retro-malleolar tibial artery, in 10% (n. 5) the medial plantar artery, in 4% (n. 2) the tarsal artery. Two-year primary patency was 85%±5. Secondary patency rates was 86%±3 at two years. The overall survival was 81% ±6 at 2 years, the amputation free survival was 70% ±9, and the limb salvage rate was 81% ±6. ConclusionPopliteal-to-distal bypass require high technical expertise to be performed. When a good autologous vein and adequate outflow artery are present, they can be feasible with good patency rates, and overall survival.