Arterial Allografts Research Articles

The place of arterial allograft in reconstructive surgery of the main arteries of the lower extremities

Critical limb ischemia, especially in the absence of autologous vein, prosthetic and native vascular infections are isolated diseases for which there currently doesn't have best surgical treatment. Vascular allografts may be the treatment of choice for these patients. In this analysis, we tried to reflect the directions of development of vascular allotransplantation, global trends related to indications for their use, methods of conservation, degradation and endothelial dysfunction. At the present time there doesn't have meta-analyzes on the efficiency of using arterial allografts or other options for implantation (synthetic graft, xenografts) for critical limb ischemia and graft and native infections. Now it is wrong to recommend using them always. Further studies of their performance are necessary. In addition, development of graft control techniques is also needed when rejection develops. Currently, there are no special diagnostic markers, the assessment of which could save patients with immune-mediated dilatation and dysfunction of allografts.

Refined surgical techniques to improve the patency of cryopreserved iliac artery homografts for middle hepatic vein reconstruction during living donor liver transplantation.

PurposeA cryopreserved iliac artery homograft (IAH) has not been considered suitable for middle hepatic vein (MHV) reconstruction during living donor liver transplantation (LDLT), primarily due to the low patency from its small diameter. We revised our surgical techniques for MHV reconstruction using an IAH to improve its patency.MethodsThis study analyzed the causes of early conduit occlusion and developed revised techniques to address this that had clinical application.ResultsThe potential risk factors for early conduit occlusion were the small IAH size, small graft in the segment V vein (V5) and segment VIII vein (V8) opening, and small recipient MHV-left hepatic vein stump. These factors were reflected to our revised surgical methods which included endarterectomy of the atherosclerotic plaque, unification of the internal and external iliac artery branches for large V5, and branch-patch arterioplasty for large V8. IAH endarterectomy, branch unification technique, and branch-patch arterioplasty were applied to 8, 5, and 5 patients, respectively and resulted in 1-month occlusion rates of 37.5%, 20.0%, and 40.0%, respectively. The overall patency rates of the IAH-MHV conduits in our 18 patients were 66.7% at 1 month, 38.9% at 3 months, and 33.3% at 1 year.ConclusionOur refined MHV reconstruction using an IAH improved short-term MHV conduit patency, but did not effectively prevent early conduit occlusion, particularly with a small- or medium-sized IAH. Individualized reconstruction designs during LDLT operation are needed when an IAH is used for a modified right liver graft.

Registry of Valvular and Vascular Allograft Transplants in the Autonomous Community of Catalonia, Spain (ReVAC): Design of the Registry

BackgroundIn recent years, there have been significant changes in the perception of valvular and vascular allograft transplants. Despite the constant evolution of the field of transplant and the involvement of multiple surgical specialties, there is not an official registry for administrative and clinical control. This study aims to design a registry of vascular and valvular allograft transplantation in Catalonia, Spain (ReVAC). Materials and MethodsThree consecutive focal groups were designed. Focal groups established administrative, technical, and clinical requirements of ReVAC. ReVAC included patients with a transplanted cryopreserved vascular segment or cardiac valves that were distributed by Catalan tissue banks to public and private hospitals in Catalonia. Ten hospitals were involved in this study. Data were collected on 380 patients between January 1995 and November 2015. ResultsThe project resulted in the completion of a growing platform available online. ReVAC was divided into the following 3 levels: patient-related, surgery-related, and transplant-related data. Online access is available through the website of applications of the "Generalitat de Catalunya." ConclusionReVAC has been useful for administrative and clinical control of transplants in Catalonia. Currently, data related to outcomes of arterial allografts are available, reinforcing the current guideline-supported indications, as well as opening a window for further analysis and guideline creation.

Analysis of Failure-mechanisms of Cryopreserved Vascular Allografts in Peripheral Reconstructions

Introduction: Cryopreserved vascular allografts represent a well known option in the treatment of vascular infections. Moreover several groups also suggested their use in case of patients with no suitable veins requiring an infragenicular bypass. The aim of the present study was to evaluate the failure mechanisms of cryopreserved allografts in peripheral reconstructions in a cohort of patients treated at a single Institution. Methods: We retrospectivly analized a prospectively collected database comprising all patients undergoing a peripheral reconstruction with cryopreserved arterial or venous allografts between August 2010 and January 2019. The composite result of graft failure (occlusion + degeneration + any graft-related complication) was calculated as a primary endpoint. In case of reintervention hystological analysis of a segment of allograft was performed. Results: A total of 20 patients [mean age 66.1 +/- 10.3 yy, M 66% (12/18)] underwent 25 vascular in-situ reconstruction with cryopreserved arterial or venous allografts. Indication for treatment was infection of a previous prosthetic graft in 12 cases, critical limb ischemia in 8, allograft degeneration in 3 and mycotic pseudoaneurym in 2. Type of reconstruction are reassumed in table I Table I. Type o.... In 17 cases an arterial allograft was used (11 single segment, 6 multiple segments) and in 8 cases a vein allograft (6 single segment, 2 multiple segments). At 30 days there were 3 deaths (1 myocardial infarction, 1 rupture of thoracic aortic aneurysm, 1 anastomotyc disrupture) with 2 additional deaths during follow up (1 drug overdose, 1 intestinal ischemia). Mean follow-up was 31 months (min 1 - max 81) with no patients lost to follow up. Overall graft failure occurred in 7 cases (28%) (3 aneurysmal degenerations, 2 occlusions, 2 anastomotyc disrupture) with reintervention with allograft performed in 4 cases. There was no statistical difference in the incidence of the composite endpoint between venous and arterial grafts [OR 0.71 (0.098 - 5.2), p 1], between patients with infection and without infection [OR 1.8 (0.26 - 12), p 0.66] and between single and multiple segments grafts [OR 2.8 (0.42 - 2.9), p 0.34], although occlusions occurred only in veins (2/8, 25%) and aneurismal degeneration only in arterial allografts (3/17, 17%). Hystological analysis was available for 5 allografts: 2 anastomotyc disruptures showing wall necrosis due to infection, 3 aneurysmal degenerations showing a chronic flogistic pattern suggestive of immune-mediated rejection. Kaplan-Meier estimates showed an overal 26% of freedom from graft failure at 60 months, with no difference between patients with and without infection and venous and arterial allografts (Logrank test p: 019 and 0.26 respectively). Conclusion: In our series the failure rate of allografts was not low, although their use was limited to very high risk situations. Accurate follow up is mandatory as the risk of aneurysmal degeneration is not negligible with arterial allografts, although they seem to offer a better patency rate compared to veins. Immune-mediated rejection plays a role in aneurysmal degeneration while uncontrollable infection greatly hinders the early postoperative outcome.Table IType of peripheral reconstruction with allografts and type of allografts usedType of ReconstructionN (%)Type of allografts (N)Composite axillo-femoral bypass1 (4%)Single Arterial (1)Femoral tibial bypass4 (16%)Multiple Arterial (2) Single Venous (1) Multiple Venous (1)Femoral femoral crossover bypass2 (8%)Single Arterial (2)Below knee femoral popliteal bypass5 (20%)Single Arterial (1) Multiple Arterial (3) Single Venous (1)Above knee femoral popliteal bypass2 (8%)Single Arterial (1) Single Venous (1)Iliac femoral bypass3 (12%)Single Arterial (2) Multiple Arterial (1)Femoral truncal bypass2 (8%)Single Venous (1) Multiple Venous (1)Common femoral reconstruction4 (16%)Single Arterial (3) Single Venous (1)Bypass of a dilated segment of a previous allograft2 (8%)Single Arterial (2) Open table in a new tab Disclosure: Nothing to disclose

Abdominal Graft and Native Aorta Infection Treated By Cryopreserved Allograft: Early and Long Term Results in 207 Patients

Introduction - Infected aorta treatment (graft or native aorta) shows both high rate of morbidity and mortality and high risk of infectious recurrence, more particularly during the perioperative period. Replacement by a bacterial-resistant substitute, such as arterial allografts more effective in this context, compared to synthetic substitutes, is therefore mandatory. This study aimed to analyzed results of the placement of cryopreserved allografts , accordingly to those indications.

Durability and Infection Resistance of Cryopreserved Femoral Vein Allografts in Suprainguinal Position. A Single Center Study

Introduction - There is no consensus about the best treatment method of aortic graft infections (AGI) and primary arterial infections in aorto-iliac area. Cryopreserved arterial allografts have proved to be infection-resistant, but long-term durability is altered by late graft thrombosis and degeneration 1,2. However, cryopreserved big caliber venous allografts’ performance in aorto-iliac position is unknown. The aim of current study was to evaluate cryopreserved femoral vein allografts’ (CVA) safety, infection resistance and durability in suprainguinal setting in infectious conditions and compare their performance with cryopreserved arterial allografts (CAA) from the same homograftbank. Methods - Patients treated from February 2012 to March 2018 with cryopreserved allografts’ reconstruction due to infection encompassing suprainguinal area in a tertiary level hospital were retrospectively reviewed. Preoperative characteristics, indication for operation, operative details, early postoperative morbidity and mortality, late mortality, re-infections and graft re-interventions during the follow-up were recorded. Univariable analysis was done using crosstabs method, survival calculated with Kaplan-Meier method. Results - 31 patients underwent cryopreserved venous (femoral vein, n=21; cava vein, n=2) or arterial (superficial femoral artery, n=6; aorta, n=1; iliac artery, n=1) allograft reconstruction due to infection in aorto-iliac area. Indications for treatment were AGI in 14 (45%), mycotic aneurysm in 5 (16%), extra-anatomical prosthetic infection in 5 (16%), secondary arterial infection with rupture in 2 (6%), anastomotic pseudoaneurysm in 2 (6%) and aortic thrombosis with intestinal spillage in 1 (3%) case. 30-day and overall treatment-related mortality was 4 (13%). During the median follow-up of 15 month, two CAAs were treated due to thrombosis, two CVAs due to anastosmotic dilatation and one CVA due to re-infection and subsequent rupture making re-intervention incidence 16% (n=5). None of the grafts were lost and there were no amputations. At the end of follow-up 22 (71%) patients were alive. Kaplan-Meier estimation of survival was 87% (95% confidence interval, 81% to 93%) at 1 year and 63% (52% to 74%) at 2 years. Univariable analysis revealed no risk factors significantly associated with 30-day mortality, however cerebrovascular disease (p=0,028) was associated with treatment-related mortality and renal insufficiency (p=0,004) with overall total mortality. Due to small number of patients statistical analysis comparing CAA and CVA were unreliable, but two acute arterial occlusions call for caution and further research. Conclusion: Cryopreserved venous allografts appear safe, infection-resistant and durable reconstruction material in aorto-iliac axis based on single center experience and mid-term analysis. Further research is needed to compare their performance to cryopreserved arterial allografts and other biological reconstruction material.

Cryopreserved Arterial Allografts for In-Situ Reconstruction of Abdominal Aortic Native or Secondary Graft Infection

Introduction - Native and aortic graft infection is rare but represents one of the most life-threatening complications in vascular surgery. The gold standard treatment includes excision of the infected aorta or graft and in-situ reconstruction using autologous veins, silver or antibiotic coated prosthesis, or cryopreserved arterial allografts (CAA). The optimal choice between these materials still remains debated. CAA has emerged as a good solution having the advantage of higher resistance to infection1,2 but also the disadvantages of potential degeneration and uncertain availability. Our aim was to evaluate the early and long-term outcome and identify predictors of mortality as regards cryopreserved arterial allografts used for in-situ reconstruction of abdominal aortic native or secondary graft infection. Methods - We retrospectively included 71 patients (mean-age: 65.2 years (range: 41-84, men: 91.5%) treated for abdominal aortic native or secondary graft infection (65 prosthetic graft infections, 16 of them had secondary aortoenteric fistula, 2 venous graft infections and 4 mycotic aneurysms) via in-situ reconstruction with CAA in two French University Hospitals, from 2001 to 2016. The cryopreservation protocol was identical in both centers (-140°C). Early (<30 days) and late (>30 days) mortality and morbidity, reinfection and CAA patency were assessed. A CT-scan was performed in all survivors. Survival was analyzed with the Kaplan-Meier method. Univariate analyses were performed with the log-rank tests and multivariate analysis with the Cox regression model. Results - Mean follow-up was 45 months (0-196). Early postoperative mortality rate was 14% (10/71). Early postoperative CAA-related mortality rate was 2.8% (2/71), both patients died from proximal anastomotic rupture on postoperative day 4 and 15. Early CAA-related reintervention rate was 5.6% (4/71), all had an anastomotic rupture and 2 were lethal. Early postoperative reintervention rate was 15.5% (11/71). Intraoperative bacteriologic samples were positive in 56.3% and 31% had a sole micro-organism. Escherichia coli was more frequently identified in the secondary aortoenteric fistula and Staphylococcus epidermidis in the infected prosthesis. Late CAA-related mortality rate was 2.8%: 1 septic shock at 2 months and 1 proximal anastomosis rupture at 1 year. Survival at 1, 3 and 5 years were 75%, 64% and 54%, respectively. Multivariate analysis identified type 1 diabetes (HR=2.49 [1.05–5.88]; P=0.04) and ASA (American Society of Anesthesiologists) score 4 (HR=2.65 [1.07–6.53], p=0.035) as predictors of mortality after in-situ CAA reconstruction. Reinfection rate was 4% (3/71). Late CAA-related reintervention rate was 12.7% (9/71): 1 proximal anastomotic rupture, 5 CAA branch stenosis/thrombosis, 1 ureteral-CAA branch fistula and 2 distal anastomosis false aneurysms. Primary patency at 1, 3 and 5 years were 100%, 93% and 93%, respectively. Assisted primary patency at 1, 3 and 5 years were 100%, 96% and 96%, respectively. No aneurysms or dilatation were observed. Conclusion - The prognosis of native or secondary aortic infections is poor. Aortic in-situ reconstruction with CAA offers acceptable early and late results. Patients with type 1 diabetes and ASA score 4 are at higher risk of mortality.

Urgent Late Open Conversions after Endovascular Abdominal Aneurysm Repair: A Multicentre Experience

Introduction - Late open conversions (LOC) after EVAR are associated with a considerably increased perioperative morbidity and mortality as compared to standard EVAR or open repair. Additionally, since the number of patients undergoing EVAR is increasing, the incidence of LOC performed for ruptured aneurysms or infected endografts will likely rise in the future. Here we report a multicentre experience of urgent LOC, with the goal of identifying technical aspects and outcomes that may alter clinical management. Methods - A retrospective analysis of EVAR requiring urgent LOC (>30 days after implantation) from 1996 to 2016 in six Vascular Centres was performed. Specifically, patients who presented with aneurysm rupture or other conditions (such as graft thrombosis, infection or aneurysm growth associated with pain) which required urgent surgery (<24h) were selectively included. Patients' demographics, duration of implant, type of endograft, previous attempts of endovascular correction, reason for LOC, operative technique (clamping site, partial or complete graft removal), 30-day mortality and post-operative complications were obtained for analysis. Long-term survival was also evaluated. Results - During the study period, 140 patients underwent LOC in the participant institutions. Among these, 42 were operated in a urgent setting and were therefore analyzed. Mean age at conversion was 75.8±9 years; 88.1% were male. Grafts were excised after a median of 37 months (range: 1.6-132.1). Multiple types of endografts have been explanted: 30/42 bifurcated endografts, 5/42 tubes, 5/42 aorto-uni-iliac and 2/42 iliac side-branch devices. A suprarenal fixation was present in the 66.7% of the endografts. Eleven patients (26.2%) underwent endovascular reintervention for endoleak repair prior to LOC. Indications for urgent LOC were: aneurysm rupture in 24/42 cases (57.1%), endograft infection in 10/42 (23.8%), endoleaks associated with aneurysm growth and pain in 6/42 (14.3%) and recurrent endograft thrombosis in 2/42 (4.8%). Proximal aortic cross-clamping site was infrarenal in 38.1% of the cases, suprarenal in 19% and supraceliac in 42.9%. Complete removal of the stent-graft was performed in 32 patients (72.6%), partial removal in the remaining 10 cases (with preservation of the proximal portion in 7/10 cases). Reconstructions were performed with dacron grafts in 33/42 cases, cryopreserved arterial allografts in 5/42 and endograft removal associated with prosthetic axillo-bi-femoral bypass in 4/42. Overall 30-day mortality was 21.4%. A suprarenal clamping site was associated with a statistically significant higher mortality rate of 34.6% (p=.007). During follow-up, we experienced 1 aneurysm-related death due to the rupture of an aortic stump. The estimated 1- and 5-year survival rates were 62% and 46%, respectively. Conclusion - Urgent LOC after EVAR are associated with high postoperative mortality rates and poor long-term survival. The need of a suprarenal clamping is associated with worse outcomes. A close follow-up after EVAR is mandatory, since early decision for elective LOC may improve postoperative outcomes in this subgroup of patients. Further studies are eagerly awaited to better define the timing and the best treatment option for failing EVAR, since a standardization of the surgical technique may improve patients' survival.

Long Term Results of In Situ Reconstruction with Cryopreserved Arterial Allografts for Secondary Aorto Enteric Fistulas

Introduction - Secondary aorto enteric fistula (SAEF) is a rare complication (0.3% to 1.6%) with a high morbidity rate. The infection rate of aortic vascular graft is described between 0.6% and 3%. SAEF represents 20 to 45% of these vascular graft infections. The treatment can be performed by different methods and in various steps. The choice of the treatment remains controversial. The objective of our study was to evaluate the long term results of the treatment of secondary aorto enteric fistulas by in situ reconstruction with cryopreserved arterial allograft. Methods - Between 1995 and 2015, 30 patients (mean age: 75 years, 27 males, 3 females) were surgically treated for SAEF in 3 French university hospitals. 16 patients were initially treated for infrarenal abdominal aortic aneurysm and 14 for occlusive aortic disease. Mean time before occurrence of SAEF was 72 months. Surgical treatment consisted of total graft excision and in situ reconstruction with cryopreserved arterial allografts as well as digestive tract reconstruction. Data were collected retrospectively. Primary endpoint was overall survival at 12 and 36 months. Secondary endpoints were primary patency, reinfection rate, postoperative morbidity and limb salvage rate. Results - Survival rate at 12 and 36 months were respectively 70% and 65%. Mean follow up was 39 months (range: 1-194). The 30-day postoperative mortality rate was 23%. Primary patency rate at 1 year and 5 years were 95% and 86%, respectively. There were 2 allograft thromboses. Limb salvage rate was 100%. There was no recurrence of aorto enteric fistula. Reinfection occurred in 2 patients (7%). The most frequent organisms identified were Candida albicans (36%) and Escherichia coli (32%). There were no bacterial findings for 5 patients (17%). The fistula was found between the graft anastomosis and the duodenum in 87% of the patients. Digestive tract treatment was performed with duodenal resection for 13 patients (47%), duodenal suture for 12 (40%), intestinal resection for 5 (17%) and 6 stoma creations. Conclusion - The long term results of SAEF treated by in situ reconstruction with cryopreserved arterial allografts were satisfactory. The occurrence of SAEF threatens the vital prognosis of the patient and long term surveillance is mandatory.

Cryopreserved Arterial Grafts in Critical Limb Ischemia: Do Immunological Factors Influence Their Patency?

Introduction: The use of cryopreserved arterial allografts (CAA) has been proposed for revascularization of patients with critical limb ischemia (CLI), when autologous material is not available. In these cases, CAA offer higher patency rates and better resistance to infection than prosthetic grafts. However, the impact of immunological phenomena on its permeability has been scarcely evaluated. We analyzed patency rates and limb salvage obtained in patients that were revascularized with CAA, and the its possible relationship with the degree of immunological compatibility between donor and recipient. Methods: This is a cohort follow up study of CLI patients undergoing revascularization with CAA, between 2008 and 2018, in a single center. We analyzed demographics and co-morbidities, CAA origin, Rh and ABO groups in donor and recipient, bypass configuration, graft patency, and limb salvage. Statistics included descriptive parameters, as well as survival (Kaplan-Meier) and Cox regression analysis. Results: We treated 68 limbs in 66 patients39 (66,67%) men), with a mean age of 68.8 years±12.2. Overall, 146 CAA segments (22 ilio-femoral, 57 femoro-popliteal, 50 axillary-radial or ulnar and 17 from other anatomical locations) were used in different bypass configurations. An average of 1.58±1.25 CAA segments per procedure were used. Perioperative mortality rate (30 days) was 10% (n=7/68). The primary patency at 12, 24 and 36 months was 54.5%, 47.2% and 43.3% respectively (mean follow-up of 27 months). At the end of the follow-up, limb salvage and aneurismal degeneration rates of the CAA were 88% (n= 53/68) and 8,8% (n=6/68) respectively. The primary patency rate at 1 year in patients without Rh compatibility was 36%, whereas with Rh compatibility were 57% (p=0.03). Survival analysis showed a hazard ratio (HR)=1.53 (95% CI 0.64-3.68, p=0.34) for graft thrombosis in ABO compatibility cases and a HR=0.38 (95% CI 0.16-0.93, p=0.03) in those cases with Rh agreement. Secondary analysis showed an HR=0.38 (95% CI 0.15-0.9, p=0.04) for graft thrombosis in patients with single antiagregation as compared with a HR=0.14 (95% CI 0.32-0.65, p=0.01) for those under double antiagregation. Conclusion: The results of this study suggest that revascularization with CAA may be a suitable option for CLI when autologous material is not available. Donor/recipient Rh compatibility and double antiagregation treatment may improve the patency rate of these grafts.

Comparison of Cryopreserved Arterial Allografts Versus Heparin-bonded Vascular Grafts in Infragenicular Bypass for Chronic Limb Threatening Ischemia

The purpose of this study was to compare cryopreserved arterial allograft (CAA) to heparin-bonded prosthesis (HBP) in infragenicular bypasses for patients with chronic limb-threatening ischemia (CLTI). This retrospective study took place in 2 university hospitals and included 41 consecutive patients treated for CLTI. In the absence of a suitable saphenous vein, an infragenicular bypass was performed using either CAA (24 cases) or HBP (17 cases). Kaplan-Meyer analysis compared primary and secondary patency and amputation-free survival rates. Binomial logistic regression analyzed risk factors for major amputation and thrombosis. The mean followup was 18.5months (±14.3) in the CAA group, 17.6 (±6.1) in the HBP group. In the CAA group, primary and secondary patency rates at 12months were 52% (±10.6) and 61% (±10.3), compared to 88% (±7.8) and 94% (±5.7) in the HBP group, respectively. The difference in patency rates was not statistically different (P=0.27 and P=0.28, respectively). The statistically significant factors of graft thrombosis were, a stage 4 from the WIfI classification (Wound Ischemia foot Infection) with a 6 times higher risk (P=0.04), and a distal anastomosis on a leg artery with a 9 times higher risk of thrombosis (P=0.03). Amputation-free survival rates at 18months were similar between the groups (CCA: 75% (±9) versus HBP: 94% (±6), P=0.11). Patients classified as WIfI stage 4 had 13 times higher odds to undergo major amputation than patients with WIfI stage 2 or 3 (95% CI, 1.16-160.93; P=0.04). The intervention was longer in the CCA group of 74min (278min±86) compared to the HBP group (203min±69). This difference was statistically significant (95% CI, 17.86-132.98), t(35)=2.671, P=0.01. CCA is not superior to HBP in infragenicular bypasses for CLTI, and may not be worth the extra cost and the longer operative duration.

Results of infra-inguinal bypasses with cryopreserved arterial allografts for critical ischemia

In presence of critical limb ischemia (CLI), the material of choice for peripheral revascularization is the greater saphenous vein (GSV) when its quality is satisfactory. In the absence of GSV, the use of a cryopreserved arterial allograft (CAA) is possible. We evaluated the results of CAA infra-inguinal bypasses in patients with CLI.

Comparative study between cryopreserved arterial allografts and heparin-coated grafts for below the knee bypasses for critical limb ischemia

The aim of this study was to compare cryopreserved arterial allografts (CAA) with heparin-coated grafts (HCG) for below the knee bypasses carried out in patients presenting with critical limb ischemia (CLI) in the absence of a suitable autologous saphenous vein.

MON-177 TRANSPLANT RENAL ARTERY STENOSIS - CLINICAL OUTCOMES WITH ANGIOPLASTY AND STENTING - A SINGLE CENTER EXPERIENCE

Transplant renal artery stenosis ( TRAS) is a recognised potentially curable cause of post-transplant arterial hypertension, allograft rejection, and graft loss. There is limited data about the effectiveness of renal stenting in transplant renal artery stenosis. The objective of this study is to document immediate and intermediate term clinical results in this subset of renal artery stenosis.

Cryopreserved Allografts for Treatment of Chronic Limb-Threatening Ischemia in Patients Without Autologous Saphenous Veins

Revascularization is the best alternative to reduce symptoms and to improve the limb salvage rate in patients with chronic limb-threatening ischemia (CLI). Alternative grafts as synthetic prostheses and allografts must be considered for patients without a suitable autologous graft. Our aim was to evaluate outcomes of cryopreserved allografts used as a vascular conduit for bypass surgery in the infrainguinal territory. A retrospective analysis (January 1995 to January 2014) of the Registry of vascular and valvular allografts transplant in the autonomous community of Catalonia, Spain was performed for identifying patients with CLI who required infrainguinal bypass with cryopreserved arterial allografts. Statistical analysis was performed using SPSS, ver. 20, for Mac (Chicago). A total of 149 patients with CLI (mean age of 70.1years) were analyzed. One hundred two patients (68.5%) had a grade IV lesion (Fontaine classification). In the overall follow-up, 24.8% of patients required a reintervention. Overall graft occlusion, infection, and dilation rate were 52.3%, 6%, and 5.4% respectively. Overall 30-day mortality was 0.7%. Five-year primary patency rate and limb salvage rate were 38.6% and 50.2%, respectively. Survival rate at 5years was 54.2%. Major adverse limb event (MALE)-free rate was 21.5% at 5years. Revascularization to a distal target vessel was an independent positive predictive risk factor for a lower limb salvage rate and lower primary patency rate. Dyslipidemia was related to a lower limb salvage rate and represents a risk factor involved in MALEs. Although arterial allografts seem to represent a suboptimal alternative, some selected patients could beneficiate from them. Five-year results are disappointing, and more studies are required to know other predictive factors for better selection of patients.

Ten Year Experience of Using Cryopreserved Arterial Allografts for Distal Bypass in Critical Limb Ischaemia

In critical limb ischaemia (CLI), current guidelines recommend revascularisation whenever possible, preferentially through endovascular means. However, in the case of long occlusions or failed endovascular attempts, distal bypasses still have a place. Single segment great saphenous vein (GSV), which provides the best conduit, is often not available and currently there is no consensus about the best alternative graft. From January 2006 to December 2015, 42 cryopreserved arterial allografts were used for a distal bypass. Autologous GSVs or alternative autologous conduits were unavailable for all patients. The patients were observed for survival, limb salvage, and allograft patency. The results were analysed with Kaplan-Meier graphs. Estimates of secondary patency at one, two and five years were 81%, 73%, and 57%, respectively. Estimates of primary patency rates at one, two and five years were 60%, 56%, and 26%, respectively. Estimates of limb salvage rates at one, two and five years were 89%, 89%, and 82%, respectively. Estimates of survival rates at one, two and five years were 92%, 76% and 34%, respectively. At 30 days, major amputations and major adverse cardiac events were one and zero, respectively. Six major amputations occurred during the long-term follow up. Despite a low primary patency rate at two years, the secondary patency of arterial allografts is acceptable for distal bypasses. This suggests that cryopreserved arterial allografts are a suitable alternative for limb saving distal bypasses in the absence of venous conduits, improving limb salvage rates and, possibly, quality of life.

Successful repair of kidney graft artery rupture secondary to infection using a preprocessed homologous "Y"-shaped iliac artery.

ObjectivesThis retrospective study aims to describe novel ways of repair kidney allograft artery rupture secondary to infection using a preprocessed homologous “Y”‐shaped iliac artery.MethodsFive patients' whose course was complicated by graft arterial rupture were included in the rupture group, and patients who received the kidney from the same donor were included in the control group. In the rupture group, the iliac artery used for revascularization was harvested from a DCD donor, pre‐treated with absolute diethyl ether, followed by absolute alcohol, and then preserved in 75% alcohol. A biopsy of the arterial graft was obtained and stained using hematoxylin and eosin (H&E). Once a patient was diagnosed with kidney allograft arterial rupture by ultrasound, emergency surgery was conducted and the preprocessed “Y”‐shaped iliac artery was used for bridging.ResultsFive patents were included in the rupture group. The “Y”‐shaped iliac artery grafts were successfully preprocessed, H&E staining and electron microscope observation revealed few visible nuclei, with karyorrhexis and karyolysis. There were no significant differences in the long‐term graft survival between two groups.ConclusionsIn conclusion, using preprocessed homologous “Y”‐shaped iliac artery provides a useful method to bridge the vascular defects from kidney graft artery rupture secondary to infection in renal allograft recipients.

Satisfactory usage of kidneys from pediatric donors with severe hand foot mouth disease.

No studies have reported making use of kidneys from pediatric donors with severe HFMD. Here, we retrospectively analyzed the feasibility and clinical effect of six cases of kidney transplantation from four pediatric donors with severe HFMD in our center between January 2014 and December 2016. The donors' age ranged from 6months to 3years and 11months. The recipients' age ranged from 18 to 41years. Single kidney transplantation was performed in four recipients, and dual splitting kidney transplantation and en bloc kidney transplantation were performed in two recipients, respectively. During the 1.5-4years follow-up, all recipients maintained normal kidney allograft function except for one recipient whose allograft was removed due to the allograft artery thrombosis. The survival rates of recipient and allograft were 100% and 83.3%, respectively. None of the six recipients showed any symptoms associated with HFMD. In conclusion, it is feasible to perform kidney transplantation from pediatric donors with severe HFMD to adult recipients with immunity to the pathogens. The clinical effect is satisfactory.

Saphenous vein conduits for hepatic arterial reconstruction in living donor liver transplantation.

Occasionally, a recipient's native hepatic arteries are not suitable for reconstruction in living donor liver transplantation (LDLT). The use of the great saphenous vein (GSV) conduits in such patients is seldom practiced since arterial conduits from deceased donors are available. Here, we share our experience with a significantly large group of LDLT recipients who underwent arterial reconstruction with GSV conduits. We reviewed patients who underwent LDLT between 2012 and 2017. Patients who had arterial reconstruction using native hepatic arteries (group 1)(n = 452) were compared with those who had GSV interposition conduits for reconstruction (group 2)(n = 21). We compared hepatic artery thrombosis (HAT) rate, allograft dysfunction, morbidity, mortality, and actuarial 5-year survival in the two groups. HAT was seen in 0/452 (0%) versus 1/21(4.7%) patients (P = 0.04). Allograft dysfunction was seen in 89/423 (21%) versus 6/19(31.5%) (P = 0.2) patients. Overall mortality was 81/452 (17.9%) versus 8/21(38%) (P = 0.02). Death after a biliary complication was seen in 24/452 (5.3%) versus 4/21 (19%) patients (P = 0.02). Actuarial 1- and 5-year overall survival was 85% versus 67% and 79% versus 58% (P = 0.008). GSV conduits are a suboptimal alternative for establishing hepatic arterial inflow in LDLT, but remain valuable in ominous situations.

Peripheral artery reconstructions using cryopreserved arterial allografts in infected fields

ObjectiveCryopreserved human arterial allografts are a recognized acceptable alternative for vascular reconstruction when other traditional conduits are either unavailable or contraindicated. We reviewed our experience using cryopreserved arterial allografts for peripheral artery reconstructions in contaminated and infected surgical fields. MethodsA single-center, retrospective review was conducted of 57 patients who underwent a peripheral vascular reconstruction using a cryopreserved arterial allograft from January 2002 through July 2017. Indications for repair included removal of infected prosthetic bypass (n = 29), revascularizations in contaminated fields (n = 11), primary arterial repair in the setting of infection (n = 10), and infected vascular closure devices (n = 7). Aorta-based repairs were excluded. Demographics, index procedural details, postoperative complications, and conduit patency were analyzed. Primary end points included conduit-related mortality and graft failure as measured by reinfection, hemorrhage, or aneurysmal degeneration. Mean follow-up for the study is 27.8 months (range, 2-125 months). ResultsA total of 57 peripheral vascular reconstructions using cryopreserved arterial allografts were performed during the 15-year period. Among the 22 women and 35 men treated, the mean age was 61 years. The vascular beds involved included iliofemoral (n = 39), femoropopliteal or femoral-distal (n = 10), axillosubclavian or brachial (n = 2), mesenteric (n = 3), and carotid (n = 3) arteries. Adjunctive muscle flap coverage of the allograft conduit was performed in the majority of cases (61%; n = 35). The 30-day mortality was 9%; one death was directly related to conduit insertion. The 30-day conduit-related complication rate was 14% and included hemorrhage from the graft requiring return to the operating room (n = 4) and graft infection (n = 4). The late conduit-related complication rate was 15.8% and included graft infection (n = 1), graft thrombosis (n = 3), major amputation resulting from conduit failure (n = 1), pseudoaneurysm degeneration requiring repair (n = 2), graft hemorrhage (n = 1), and symptomatic graft stenosis (n = 1). ConclusionsA cryopreserved arterial allograft is a useful alternative conduit for peripheral vascular reconstruction in infected or contaminated surgical fields when other autologous or prosthetic conduits are either unavailable or contraindicated. In the immediate postoperative period, these repairs demonstrate acceptable resistance to graft failure and reinfection, particularly in conjunction with adjunctive rotational muscle flap coverage. Late conduit-related complications appear to be infrequent.