Venous allografts preserved at 4 degrees C for infrainguinal bypass: long-term results from 170 procedures

Evaluation of Arterial and Venous Allografts in Subinguinal Bypasses

BACKGROUND

Autologous saphenous vein is the preferred conduit for below-the-knee bypasses in patients with critical limb-threatening ischemia. Alternative graft must be considered for patients without (autologous saphenous vein). The aim of this article is to evaluate the mid-term performance of arterial allograft (AA) and venous allograft (VA) used as alternative conduits.

METHODS

This retrospective study included patients with critical limb-threatening ischemia, with or without a history of homolateral femoropopliteal bypass, and no autologous veins were available who underwent infrainguinal arterial reconstructions using VA or AA from 2008 to 2018. Patients undergoing revision operations for infected bypasses were excluded. Primary patency (PP), primary assisted patency, secondary patency, major amputation, and death from any cause were the endpoints. For each event, a set of analyses were performed.

RESULTS

Overall, 111 patients (63 VAs and 48 AAs) were included, with 108 having below-the-knee bypass. The median follow-up time was 27.8 months (15.6-37.4). The difference in PP between the 2 allograft types was significant (P = 0.049), with 65.9% (43.7-81.0), 44.1% (24.2-62.3), and 44.1% (24.2-62.3) in the AA group, respectively, at 6, 12, and 18 months, whereas 55.6% (40.0-68.6), 46.0% (30.6-60.2), and 33.2% (18.2-49.0) in the VA group. The choice of an AA over a VA was an independent factor associated with patency (for PP: hazard ratio [HR] = 0.43 [0.24-0.75], P = 0.003); primary assisted patency: HR = 0.52 (0.30-0.89], P = 0.018; and secondary patency: HR = 0.49 (0.27-0.88), P = 0.016. The allograft type did not affect either the incidence of major amputation or death from any cause (respectively, HR = 1.20 [0.49-2.93], and 0.88 [0.37-2.14]).

CONCLUSIONS

The nature of the allograft appears to influence the patency of infrainguinal reconstruction, but not the course of the disease. Performant alternative grafts answering infectious issues are needed.

Fresh cold-stored vascular allografts in subgenicular location: Our experience with rescue endovascular techniques

OBJECTIVE

Critical limb ischemia (CLI) is considered the most severe pattern of peripheral artery disease. CLI is associated with high rates of morbidity and mortality and a high risk of limb amputation. In the absence of appropriate autologous grafts, unsuitability of prosthetic bypasses and endovascular methods, fresh cold-stored venous allografts is an option. Endovascular interventional methods are essential methods for maintaining primary and secondary patency.

METHODS

A single-centre retrospective analysis of 82 surgical revascularizations using allogeneic vascular grafts and rescue endovascular techniques restoring and maintaining the patency of these allogeneic revascularizations in the period between 7/2005 and 7/2021.

RESULT

We have performed 82 allogeneic revascularizations in 75 patients (52 reconstructions in men /63.4%/, 30 reconstructions in women /36.6%/). The median age of patients was 68 years (49 min, 87 max). We subsequently had to intervene a total of 26 bypasses. We intervened in 30 acute occluded allogeneic bypass grafts and 9 failing stenotic bypass grafts. We performed 52 angiographies. The success rate of rescue endovascular procedures in primary allogeneic reconstruction with distal anastomosis to the popliteal artery is statistically significant (p <0.02) compared to procedures with distal anastomosis to the tibial and pedal bed. The cumulative patency (primary at time) of allogeneic reconstructions in our group was 89% after 1 month, 51.9% after 12 months, 24.2% after 3 years, 9.8% after 5 years. Limb salvage was 72.6% in 1 year, 53% in 3 years, 36.5% in 5 years, respectively.

CONCLUSION

Cold-stored venous allografts may be used for performing below-the-knee revascularization for CLI with acceptable results despite poor long-term patency. Rescue endovascular techniques are an essential method for restoring or maintaining the patency of these reconstructions. These techniques have a high success rate and no other alternative.

Cold-stored cadaveric venous allograft for superior mesenteric/portal vein reconstruction during pancreatic surgery

BACKGROUND

SMV/PV resection has become common practice in pancreatic surgery. The aim of this study was to evaluate the technical feasibility and surgical outcome of using cold-stored cadaveric venous allografts (AG) for superior mesenteric vein (SMV) and portal vein (PV) reconstruction during pancreatectomy.

METHODS

Patients who underwent pancreatic resection with concomitant vascular resection and reconstruction with AG between January 2006 and December 2014 were identified from our institutional prospective database. Medical records and pre- and postoperative CT-images were reviewed.

RESULTS

Forty-five patients underwent SMV/PV reconstruction with AG interposition (n = 37) or AG patch (n = 8). The median operative time and blood loss were 488 min (IQR: 450-551) and 900 ml (IQR: 600-2000), respectively. Major morbidity (Clavien ≥ III) occurred in 16 patients. Four patients were reoperated (thrombosis n = 2, graft kinking/low flow n = 2) and in-hospital mortality occurred in two patients. On last available CT scan, 3 patients had thrombosis, all of whom also had local recurrence. Estimated cumulative patency rate (reduction in SMV/PV luminal diameter <70% and no thrombosis) at 12 months was 52%.

CONCLUSION

Cold-stored cadaveric venous AG for SMV/PV reconstruction during pancreatic surgery is safe and associated with acceptable long-term patency.

The peritoneum as a natural scaffold for vascular regeneration

Objective

The peritoneum has the same developmental origin as blood vessels, is highly reactive and poorly thrombogenic. We hypothesize that parietal peritoneum can sustain development and regeneration of new vessels.

Methods and Results

The study comprised two experimental approaches. First, to test surgical feasibility and efficacy of the peritoneal vascular autograft, we set up an autologous transplantation procedure in pigs, where a tubularized parietal peritoneal graft was covered with a metal mesh and anastomosed end-to-end in the infrarenal aorta. Second, to dissect the contribution of graft vs host cells to the newly developed vessel wall, we performed human-to-rat peritoneal patch grafting in the abdominal aorta and examined the origin of endothelial and smooth muscle cells. In pig experiments, the graft remodeled to an apparently normal blood vessel, without thrombosis. Histology confirmed arterialization of the graft with complete endothelial coverage and neointimal hyperplasia in the absence of erosion, inflammation or thrombosis. In rats, immunostaining for human mitochondri revealed that endothelial cells and smooth muscle cells rarely were of human origin. Remodeling of the graft was mainly attributable to local cells with no clear evidence of c-kit+ endothelial progenitor cells or c-kit+ resident perivascular progenitor cells.

Conclusions

The parietal peritoneum can be feasibly used as a scaffold to sustain the regeneration of blood vessels, which appears to occur through the contribution of host-derived resident mature cells.

Basic data related to surgical infrainguinal revascularization procedures: a twenty year update

In 1990, Dalman and Taylor published a compilation of reported data that were identified by them as related to infrainguinal revascularization procedures in peripheral vascular surgery during the decade of the 1980s. The intervening 20 years has seen revolutionary advances in the field of peripheral vascular surgery, especially in the adoption of endovascular techniques, and an explosion of data related to emerging technologies in the field of infrainguinal revascularization. The tables in this manuscript reflect the evolution of our surgical knowledge during the turn of the 21st century. The superior patency of autologous saphenous vein in all positions is reaffirmed.

Fifteen years of infrapopliteal arterial reconstructions with cryopreserved venous allografts for limb salvage

OBJECTIVE

The availability of autologous vein grafts remains the limiting factor in infragenual bypass surgery in many patients with critical limb ischemia (CLI). Alternatives such as prosthetic conduits are known to have a poor outcome and most are not resistant to infection. Based on previous experimental work, we started to use cryopreserved saphenous vein allografts for this indication 15 years ago. To evaluate their outcome, we performed a retrospective study of those bypasses with distal anastomosis on a crural or pedal vessel.

METHODS

Between November 1991 and December 2005, 108 cryopreserved great saphenous vein allografts were implanted for in 92 patients (42 women, 50 men) with a mean age of 71 years (range, 39-88 years). All patients received low-dose immunosuppressive therapy for up to 1 year after intervention. Follow-up was conducted until amputation, death, or the end of the study in March 2007.

RESULTS

Nondiabetic atherosclerosis the cause of CLI in 57%, 41% had diabetes, and 2% had Buerger disease. Forty-one conduits were performed for primary reconstructions and 67 for redo reconstructions. During a mean follow-up of 26.4 months, 69 occlusions occurred. Primary and secondary patency rates were 56% and 73% at 1 year, 32% and 60% at 3 years, and 17% and 38.5% at 5 years. Survival rates were 87.4% at 1 year and 64.5% at 5 years. At multivariate analysis, the intake of statins was predictive for improved patency (hazard ratio [HR], 0.09; P = .024) and for prolonged survival (HR, 0.335; P = .045). The presence of diabetes showed a trend for inferior patency (HR, 2.325; P = .116) and for decreased amputation risk (HR, 0.592; P = .078).

CONCLUSION

Cryopreserved saphenous vein allografts are a valuable alternative to prosthetic materials when autologous veins are not available. Our limb salvage and patency rates are higher then those described for prosthetic grafts at the infrapopliteal level in most studies. Moreover, these grafts are resistant to infection when performed for revascularization in patients with an infected ulcer. Better graft and patient selection, better graft surveillance and immunologic matching, and standard use of statins could possibly improve the results even further. Shortage in availability might be a limiting factor for their widespread use.

Cold-stored Venous Allografts in the Treatment of Critical Limb Ischaemia

OBJECTIVES

To assess the outcome of cold-stored venous allografts in critically ischemic limbs in patients with no ipsilateral autogenous greater saphenous vein.

DESIGN

A non-randomised, retrospective, single-center study.

METHODS

From September 2000 to June 2006, 46 cold-stored venous allografts obtained during multiorgan harvest were implanted into 44 critically ischaemic limbs of 43 patients. The indication for reconstructions was rest pain (24%) or tissue lost (76%). Sixty-seven percent of procedures were performed as secondary reconstructions, and 61% of veins were anastomosed to tibial or pedal arteries. Thirty-seven percent of patients received prednisone, and 46% tacrolimus as postoperative immunosuppressive therapy. Mean patient follow-up period was 13.3 months (range 1 week to 60 months).

RESULTS

The secondary patency rate for the cohort was 83+/-5.6% at 1 month, 64+/-8.2% at 6 months, 57+/-10.0% at 12 months and 46+/-10.7% at 24 months. Limb salvage rate was 96+/-3.1% at 1 month, 78+/-6.9% at 6 months, 71+/-8.1% at 12 months and 50+/-11.8% at 24 months.

CONCLUSION

Cold-stored venous allografts are an alternative conduit for limb salvage procedures when ipsilateral autogenous vein is unavailable.

Meta-analysis of allograft bypass grafting to infrapopliteal arteries

OBJECTIVE

To determine graft patency and limb preservation after allograft bypass grafting to infrapopliteal arteries for different allograft materials.

DESIGN

Meta-analysis of case series that used survival analysis to describe outcomes.

METHODS

Studies published from 1982 through 2003 were identified from electronic databases and pertinent original articles. Four series of cryopreserved arterial allografts, 10 series of cryopreserved vein allografts, three series of cold-storaged vein allografts, and 16 series of umbilical-cord vein allografts were included in separate random-effects meta-analyses.

RESULTS

A graphical display of pooled survival curves of graft patency showed cold-storaged veins to have the best outcome in the first 4 years, followed by cryopreserved arteries, umbilical-cord veins, and cryopreserved veins. The respective 5-year pooled patency were 24, 21, 30, and 19%. For foot preservation, the best outcome was achieved with cryopreserved arteries followed by cryopreserved veins, umbilical-cord veins, and cold-storaged veins. A reference meta-analysis of polytetrafluoroethlylene grafts occupied the top position for graft patency and the second position for foot preservation.

CONCLUSION

In leg revascularisation for critical ischaemia, graft patency is poor for allografts generally, but using peripheral allografts in repeat attempts at revascularisation is a valid strategy to prevent major amputation. A role for umbilical-cord vein allografts remains uncertain.

Donor-specific sensitization by cadaveric venous allografts used for arterial reconstruction in peripheral arterial occlusive vascular disease

The use of allogeneic venous grafts from postmortal organ donors allows for the reconstruction of critically affected arteries in patients with peripheral occlusive vascular disease. We were interested to determine the prevalence and specificity of anti-HLA antibodies in patients after allogeneic vein transplantation. Anti-HLA class I and II alloantibodies were analyzed by flowcytometric analysis using color-coded microbeads coated with HLA antigens including recombinant single antigens. Nine out of 10 patients involving 12 venous allografts were positive for anti-HLA alloantibodies. All antibody-positive patients carried both anti-HLA class I and II alloantibodies. Anti-donor HLA specificity of the anti-HLA alloantibodies was seen in seven out of nine patients for anti-class I antibodies and in eight out of nine patients for anti-HLA class II antibodies. A high rate of donor-specific allosensitization was seen after allogeneic venous transplantation. In conclusion, allosensitization not only includes a humoral response against the constitutively expressed class I antigens but also extends to class II antigens.

[Homologous vein transplantation in cruropedal arterial reconstruction]

Allogenic venous transplantation represents an alternative procedure for preventing leg amputation. This study reviewed the question of whether immunologic monitoring and immunosuppressive therapy provide results close to those of autologous reconstructions. Twenty-eight patients received 31 homologous venous transplants. The average age in this group of 15 women and 13 men was 64.5 years. Limbs in danger of amputation could be kept longer in two thirds of them. These promising results show the superiority of this method over the use of alloplastic material in regions with cruropedal vessels. Therefore, it can be recommended in acute leg ischemia with lack of autologous vascularity. Improving guidelines for indication will be an interesting research field, and more contributions are needed.

SALVAGE OF COMPROMISED RENAL VESSELS IN KIDNEY TRANSPLANTATION USING THIRD-PARTY CADAVERIC EXTENDERS: IMPACT ON POSTTRANSPLANT ANTI-HLA ANTIBODY FORMATION

Kidney transplant surgery can be complicated by short, attenuated, or injured renal vessels which are now more frequently encountered with laparoscopic right donor nephrectomy. We describe a technique to overcome this problem in seven recipients (2 cadaveric and 5 living donors) by constructing third-party "vascular extenders" using cadaveric iliac vessels retrieved previously and preserved at 4 degrees C in University of Wisconsin solution. Mean vessel cold storage time was 25.7 days (range, 2-56 days). Immunosuppression consisted of sirolimus, mycophenolate mofetil, and steroids. Prompt reperfusion of all allografts was observed, and there were no surgical complications. Integrity of the extenders was confirmed using serial MAG3 renal scans and magnetic resonance angiography. Mean serum creatinine was 1.44 mg/dl at 19.2 months (range, 0.7-2 mg/dl at 3-31 months). Each recipient had a negative posttransplant kidney donor specific flow cytometry crossmatch. Two recipients developed HLA antibodies, one to DR7 and another DR13 (mismatched to the vessel donor) at 4 and 11 months posttransplant, respectively.