Peripheral artery reconstructions using cryopreserved arterial allografts in infected fields

Outcomes of biosynthetic collagen prostheses with comparison to cryopreserved arterial homografts for bypass reconstruction in infrainguinal vascular graft infections

BACKGROUND AND AIMS

Managing infrainguinal vascular graft infections (VGI) in bypass reconstruction is complex. Although an autologous vein is the preferred graft material, alternative conduits are required when autologous veins are unavailable. This study aimed to compare the efficacy of cryopreserved arterial homografts and biosynthetic glutaraldehydemodifiedovine collagen grafts (Omniflow II) for the treatment of infrainguinal VGI.

METHODS

The study was retrospective across two centers and included patients with infrainguinal VGI treated with cryopreserved arterial homografts or Omniflow II grafts between 2009 and 2019. Freedom from reinfection, primary patency rates, amputation-free survival, and overall survival were analyzed using 5-year Kaplan-Meier estimates.

RESULTS

Overall, 63 patients with infrainguinal VGI were treated with either Omniflow II grafts (n = 34) or cryopreserved arterial homografts (n = 29). At 5 years, freedom from reinfection was 97.1% for Omniflow II grafts and 93.1% for cryopreserved arterial homografts (p = .4). Primary patency was 50% for Omniflow II grafts and 55.2% for the cryopreserved arterial homografts (p = .5). Amputation-free survival was 52.9% for Omniflow II grafts and 55.2% for cryopreserved arterial homografts (p = .7). No graft degeneration or graft ruptures were observed during the follow-up.

CONCLUSIONS

This study suggests that biosynthetic grafts are viable and accessible alternatives for traditional graft materials, offering similar efficacy and ease of use. Although autologous vein grafts remain the gold standard for VGI management, biosynthetic grafts may serve as a viable alternatives to cryopreserved arterial homografts in the treatment of infrainguinal VGIs.

Novel surgical approach - cadaveric inferior vena cava graft reconstruction following leiomyosarcoma resection: A case report

BACKGROUND

Inferior vena cava (IVC) leiomyosarcomas are rare and aggressive tumors. Complete cure depends on achieving R0 resection, which often requires circumferential resection and reconstruction. Synthetic grafts have traditionally been used when venous continuity must be restored. However, the use of cadaveric IVC grafts for reconstruction has not been widely reported.

CASE SUMMARY

Herein, we present the case of a 64-year-old woman diagnosed with an intrahepatic IVC leiomyosarcoma with local invasion. The patient responded favorably to chemotherapy and subsequently underwent an en bloc right hepatectomy, retrohepatic IVC resection, and reconstruction with an interpositional cadaveric IVC graft. Serial imaging follow-ups until 2 years after the operation showed persistent patency of the graft and no graft-related complications.

CONCLUSION

Cadaveric IVC grafts are an alternative to synthetic grafts for reconstruction, with acceptable outcomes. Larger, long-term studies are necessary to validate these findings.

Prospective Study of Recipient Human Leukocyte Antigen (HLA) Alloimmunization Following the Use of Cold-Stored Saphenous Vein Allografts in Vascular Surgery

Objectives: The aim of this study was to assess the HLA alloreactivity of cold-stored saphenous vein allografts (CSVAs) by identifying the production of HLA donor-specific antibodies (DSAs) in the recipient. The secondary objective was to evaluate CSVA rejection-related complications, such as CSVA thrombosis and/or aneurysmal degeneration in the recipient. Methods: This was a single-center, prospective, experimental before-and-after study which included participants undergoing CSVA placement, either to create a vascular access (VA) for hemodialysis or to create a lower limb arterial bypass. On Day 1, before CSVA placement, total blood samples were taken for HLA typing by sequence-specific primers (SSPs) and anti-HLA antibody detection using a Luminex assay. One month after CSVA placement, a second blood sample was taken to assess the appearance of donor-specific antibodies or an increase in the level of anti-HLA antibodies. Patency of the CSVA and potential aneurysmal degeneration were evaluated at 3 and 6 months with a Doppler ultrasound checkup. Results: From September 2022 to November 2023, 45 patients were included (30 men, 67%; mean age: 71 ± 12 years). One month after CSVA placement, no appearance of de novo anti-HLA antibody was detected in anti-HLA antibody-negative patients at inclusion (n = 28). Among the patients who already had anti-HLA antibodies at inclusion (n = 17), no increase in anti-HLA antibody levels or appearance of de novo anti-HLA antibodies was detected. Conclusions: This prospective study evaluating the immunogenicity of CSVAs through the appearance of anti-HLA antibodies one month after placement demonstrates that they do not seem to induce any HLA alloreactivity. Therefore, they may be used without the risk of HLA immunization in patients awaiting organ transplantation.

Cold Storage of Human Femoral Arteries for Twelve Months: Impact on Mechanical Properties

OBJECTIVE

This biomechanical pre-clinical study aimed to assess the consequences on mechanical properties of long term cold storage (+2 to +8 °C) of arterial allografts.

METHODS

Femoropopliteal arterial segments were collected from multiorgan donors and stored at +2 to +8 °C for twelve months in saline solution with added antibiotics. Mechanical characterisation was carried out using two different tests, with the aim of defining the physiological modulus and the maximum stress and strain borne by the sample before rupture. These characterisations were carried out after zero, six, and twelve months of storage for each sample (T0, T6, and T12, respectively). For comparison, the same tests were performed on cryopreserved femoropopliteal segments after thawing.

RESULTS

Twelve refrigerated allografts (RAs), each divided into three segments, and 10 cryopreserved allografts (CAs) were characterised. The median (interquartile range [IQR]) Young's modulus was not statistically significantly different between the storage times for cold stored allografts: RAT0, 164 (150, 188) kPa; RAT6, 178 (141, 185) kPa; RAT12, 177 (149, 185) kPa. The median (IQR) Young's modulus of the CA group (153; 130, 170 kPa) showed no significant differences from the RA groups, irrespective of storage time. Furthermore, median (IQR) maximum stress and strain values were not significantly different between the different groups: for maximum stress: RAT0, 1.58 (1.08, 2.09) MPa; RAT6, 1.74 (1.55, 2.36) MPa; RAT12, 2.25 (1.87, 2.53) MPa; CA, 2.25 (1.77, 2.61) MPa; and for maximum strain: RAT0, 64% (50, 90); RAT6, 79% (63, 84); RAT12, 72% (65, 86); CA, 67% (50, 95).

CONCLUSION

Cold storage for up to twelve months appears to have no impact on the mechanical characteristics of human arterial allografts. Therefore, this preservation method, which would greatly simplify routine care, seems feasible. Other indicators are being studied to verify the safety of this preservation process before considering its use in vivo.

Literature review on management of prosthetic graft infections after supra-aortic bypass surgery, based on a case report

BACKGROUND

Graft infections of supra-aortic bypasses are rare, but often life-threatening. Guidelines for treatment of graft infections recommend systemic antibiotics and complete graft removal, followed by in-situ or extra-anatomic revascularisation.

METHODS

Based on case report, literature search was performed on Medline, Google Scholar and Web of Science databases, focussing on infected supra-aortic bypass reconstructions. Inclusion criterium was prosthetic graft infection, excluding stent and carotid patch infections.

RESULTS

A 68-year old man with clinically infected subclavian-subclavian bypass with interposition bypass to left carotid bifurcation, presented at emergency department with manifestation of sepsis. A total graft removal and an extra-anatomical prosthetic reconstruction was created, from right common carotid artery to left carotid bifurcation. Defect of prior left subclavian anastomosis was primarily closed, on right subclavian anastomosis per-operative acute bleeding occured, which was controlled by covered stent through right brachial artery. Literature review identified 16 cases. Different approaches ranging from open repair with autologous (six) or allogenic (two) material, to hybrid techniques (eight) have been described. No re-infections were reported. When comparing different types of approaches, no differences are found concerning overall complications.

CONCLUSION

Complete graft removal with extra-anatomical reconstruction is challenging, but crucial in supra-aortic graft infections. Preservation of parts of vascular prosthesis depends on case-by-case basis, according to infection site and general condition of the patient. But due to rarity, only case reports are available, so no strong recommendations can be formulated. International registries should be initiated to share experiences and provide data for decent analysis of short, mid and long term outcomes.

The Management of Aneurysmal Degeneration of Lower Extremity Cryopreserved Saphenous Vein Bypass Grafts

BACKGROUND

The use of cryopreserved saphenous veins (CSVs) for the treatment of lower extremity peripheral arterial disease is an attractive option when there is no available autogenous vein. Prior studies found CSVs are at risk for aneurysmal degeneration requiring reoperation. As the management of these complications and patient outcomes is not well described, the objective of this case series is to describe the open and endovascular management of degenerative CSVs at a tertiary community center.

METHODS

All CSVs implanted for lower extremity bypass at our institution between 2001 and 2021 were retrospectively reviewed. All CSVs with evidence of aneurysmal change were included in this study. CSVs with evidence of active infection were excluded. The decision to intervene was left to the discretion of the operating surgeon. Demographic data, indications for the index operation, and details about subsequent interventions for degenerative CSVs were recorded. Study end points included limb salvage and continued patency. Demographic data, indications for the index operation, and details about subsequent interventions for degenerative CSVs were recorded.

RESULTS

Seventeen bypasses were identified to have aneurysmal degeneration in 13 patients in the absence of infection between 2001 and 2021. Nine of the 13 patients were male, and the average age and body mass index during the index procedure were 72 and 28, respectively. Indications for the index bypass included acute limb ischemia (9), popliteal aneurysm (2), and chronic limb threatening ischemia with Rutherford's class IV (5) and V (1). The mean time between the index procedure and first graft revision due to aneurysmal changes was 4 years. Most of the aneurysms did not occur at the site of anastomosis with 13 occurring in the body of the graft. Thirteen grafts were managed with open surgery and 3 were managed with endovascular techniques. All endovascular repairs were managed via covered stenting. Patients were followed for an average duration of 7 years from the initial bypass and 2 years from their last aneurysmal repair. Limb salvage in this cohort was 87% with 2 limbs requiring amputation, all of whom underwent open reconstruction. The mortality rate in this series was 54% and no patients died due to complications from their graft. Continued patency on Kaplan Meier survival curve analysis was 79% at 6 months, 65% at 1 year, 54% at 3 years, and 27% at 5 years.

CONCLUSIONS

In our experience, aneurysmal degeneration of CSV grafts was mostly managed with standard open surgical techniques, although endovascular therapy also proved acceptable. Limb salvage rates and continued patency of repair at 1 year in this cohort were acceptable. This case series highlights the importance of diligent surveillance for patients with CSVs.

Contemporary outcomes for arterial reconstruction with non-saphenous vein cryo-preserved conduits

OBJECTIVE

Cryopreserved (CP) products are utilized during challenging cases when autogenous or prosthetic conduit use is not feasible. Despite decades of experience with cadaveric greater saphenous vein (GSV), there is limited available data regarding the outcomes and patency of other CP products, specifically arterial and deep venous grafts. This study was designed to evaluate outcomes of non-GSV CP conduits in patients undergoing urgent, emergent, and elective arterial reconstruction at our institution. We hypothesized that non-GSV CP allografts have adequate patency and outcomes and are therefore a feasible alternative to GSV in settings where autologous graft is unavailable or prosthetic grafts are contraindicated.

METHODS

This study was approved by the Institutional Review Board at our institution. We retrospectively reviewed charts of patients undergoing arterial reconstructions using CP conduits from 2010 to 2022. Data collected included demographics, comorbidities, smoking status, indications for surgery, indication for CP conduit use, anatomic reconstruction, urgency of procedure, and blood loss. Time-to-event outcomes included primary and secondary graft patency rates, follow-up amputations, and mortality; other complications included follow-up infection/reinfection and 30-day complications, including return to the operating room and perioperative mortality. Time-to-event analyses were evaluated using product-limit survival estimates.

RESULTS

Of 96 identified patients receiving CP conduits, 56 patients received non-GSV conduits for 66 arterial reconstructions. The most common type of non-GSV CP product used was femoral artery (31 patients), followed by aorto-iliac artery (22 patients), and femoral vein (19 patients), with some patients receiving more than one reconstruction or CP product. Patients were mostly male (75%), with a mean age of 63.1 years and a mean body mass index of 26.7 kg/m2. Indications for CP conduit use included infection in 53 patients, hostile environment in 36 patients, contaminated field in 30 patients, tissue coverage concerns in 30 patients, inadequate conduit in nine patients, and patient preference in one patient. Notably, multiple patients had more than one indication. Most surgeries (95%) were performed in urgent or emergent settings. Supra-inguinal reconstructions were most common (53%), followed by extra-anatomic bypasses (47%). Thirty-day mortality occurred in 10 patients (19%). Fifteen patients (27%) required return to the operating room for indications related to the vascular reconstructions, with 10 (18%) cases being unplanned and five (9%) cases planned/staged. Overall survival at 6, 12, and 24 months was 80%, 68%, and 59%, respectively. Primary patency at 6, 12, and 24 months was 86%, 70%, and 62%, respectively. Amputation freedom at 6 months, 12 months, and 24 months was 98%, 95%, and 86%, respectively for non-traumatic indications.

CONCLUSIONS

Non-GSV CP products may be used in complex arterial reconstructions when autogenous or prosthetic options are not feasible or available.

Cryopreserved arterial allografts vs autologous vein for arterial reconstruction in infected fields

OBJECTIVE

Peripheral arterial infections are rare and difficult to treat when an in situ reconstruction is required. Autologous vein (AV) is the conduit of choice in many scenarios. However, cryopreserved arterial allografts (CAAs) are an alternative. We aimed to assess our experience with CAAs and AVs for reconstruction in primary and secondary peripheral arterial infections.

METHODS

Data from patients with peripheral arterial infections undergoing reconstruction with CAA or AV from January 2002 through August 2022 were retrospectively analyzed. Patients with aortic- or iliac-based infections were excluded.

RESULTS

A total of 42 patients (28 CAA, 14 AV) with a mean age of 65 and 69 years, respectively, were identified. Infections were secondary in 31 patients (74%) and primary in 11 (26%). Secondary infections included 10 femoral-femoral grafts, 10 femoropopliteal or femoral-distal grafts, five femoral patches, four carotid-subclavian grafts, one carotid-carotid graft, and one infected carotid patch. Primary infection locations included six femoral, three popliteal, and two subclavian arteries. In patients with lower extremity infections, associated groin infections were present in 19 (56%). Preoperative blood cultures were positive in 17 patients (41%). AVs included saphenous vein in eight and femoral vein in six. Intraoperative cultures were negative in nine patients (23%), polymicrobial in eight (21%), and monomicrobial in 22 (56%). Thirty-day mortality occurred in four patients (10%), two due to multisystem organ failure, one due to graft rupture causing acute blood loss and myocardial infarction, and one due to an unknown cause post-discharge. Median follow-up was 20 months and 46 months in the CAA and AV group, respectively. Graft-related reintervention was performed in six patients in the CAA group (21%) and one patient in the AV group (7%). Freedom from graft-related reintervention rates at 3 years were 82% and 92% in the CAA and AV group, respectively (P = .12). Survival rates at 1 and 3 years were 85% and 65% in the CAA group and 92% and 84% in the AV group (P = .13). Freedom from loss of primary patency was similar with 3-year rates of 77% and 83% in the CAA and AV group, respectively (P = .25). No patients in either group were diagnosed with reinfection.

CONCLUSIONS

CAAs are an alternative conduit for peripheral arterial reconstructions when AV is not available. Although there was a trend towards higher graft-related reintervention rates in the CAA group, patency is similar and reinfection is rare.

Vascular allografts for clinical application in Europe: assessment of 30 years of experience with vascular tissue banking in Brussels

Vascular tissue banking has been carried out in Brussels for over 30 years in compliance with EU and Swiss tissue banking regulations. A total of 2.765 vascular tissue donations were performed in Belgian, French, Netherlands and Suisse transplant centres: 547(20%), 1.013(37%) and 1.205(43%) during the first, second and third periods, respectively. 85% and 18% increase in donations during the second and third decades compared to previous one, were remarkable. Of the 7.066 evaluated vascular tissues, 2.407(227, 921 and 1.259) were discarded (34.1%), whereas 4.659(523, 1.861 and 2.275) accepted (65.9%) during the respective period. Of the 92 donated veins, 44(47.8%) were discarded and 48(52.2%) accepted. Allografts available for clinical application were stored in vapours of liquid nitrogen. A total of 4.636 allografts were delivered and transplanted for cases of infection (58%), critical limb ischaemia (16%) and congenital cardiac surgery (15%). Thirty veins were implanted. The progressive increases in donations of 20%, 37% and 43% and in transplantations of 20.8%, 34.6% and 45% during the first, second and third periods, respectively, were remarkable. Complications were reported after transplantation and these included acute rejection of two femoral arteries one month after transplantation. We conclude that the donation and transplantation of cryopreserved vascular allografts was stable with a progressive increase over time. Allografts were used predominantly for the treatment of infection, limb salvage for critical ischaemia and for neonates and infants with congenital cardiac malformation. Immune related rejection was observed. This should be a subject of future investigation.

Carotid-Axillary Bypass and Debridement for a Mycotic Aneurysm of the Left Subclavian Artery

Mycotic subclavian aneurysms are rare, and their presence typically mandates urgent repair due to the associated high risk of rupture and mortality. A multi-disciplinary team effort is of utmost importance in ensuring favorable results. In this case report, we present a 79-year-old male with a rapidly enlarging mycotic left subclavian artery aneurysm secondary to a retrosternal abscess and left sternoclavicular septic arthritis, who underwent aneurysmal exclusion, a left carotid-left axillary bypass and pectoralis muscle flap coverage with a good outcome.

Microbiological assessment of arterial allografts processed in a tissue bank

The transmission of microbial infection through tissue allografts is one of the main risks that must be controlled in tissue banks. Therefore, microbiological monitoring controls and validated protocols for the decontamination of tissues during processing have been implemented. This study is based on the evaluation of data from microbiological cultures of arteries (mainly long peripheral arteries) processed in the tissue bank of Valencia (Spain). Donors' profile, pre- and post-disinfection tissue samples were assessed. The presence of residual antibiotics in disinfected tissues was determined and the antimicrobial potential of these tissues was tested. Our overall contamination rate was 23.69%, with a disinfection rate (after antibiotic incubation) of 87.5%. Most (76.09%) of the microbial contaminants were identified as Gram positive. Arterial allografts collected from body sites affected by prior organ removal showed higher risk of contamination. Only vancomycin was detected as tissue release. The antimicrobial effect on Candida albicans was lower than that for bacterial species. Risk assessment for microbial contamination suggested the donor's skin and the environment during tissue collection as the main sources for allograft contamination. Antibiotic-disinfected arterial allografts showed antimicrobial potential.

Cardiovascular tissue banking activity during SARS-CoV-2 pandemic: evolution of national protocols and Lombardy experience

The worldwide pandemic outbreak due to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has created unprecedented challenges for public health services. Lombardy, region of the Northern Italy, has been the first area in the Western world whose organs and tissues procurement programs have had to face the virus pandemic emergency. We retrospectively collected and analyzed data about cardiovascular tissues (CT) in 2019 and in 2020. We aimed to describe the rapid evolution of SARS-CoV-2 regulation laws for tissue donor’s selection and harvesting from February 2020 until January 2021. As expected the number of CT donors in 2020 was significantly lower than those of 2019 (66 vs. 99, p value 0.02). The total number of CT collected from donors have been 254 in 2019 and 206 in 2020 (p 0.28). Femoral arteries were the most required vascular tissues (55.5% in 2019 and 40% in 2020). Fifty-five and forty-eight pulmonary valves were implanted in 2019 and 2020, respectively. No differences were found for the types of CT requests between the 2 years. The median age of receivers of vascular tissues was 69.6 ± 14.6 years in the 2019 and 63.3 ± 14.9 years in 2020 (p < 0.01). The median age of receivers of pulmonary and aortic valves did not differ between the 2 years (9.32 ± 11.49 vs. 8.36 ± 10.66 and 48.67 ± 27.19 vs. 37.14 ± 31.97 respectively). Despite the dramatically reduction of donors, the number of CT collected has not decreased significantly and so far the CT distribution rate is comparable to those of 2019.

Endovascular stenting and coil embolization for management of radiation-induced pseudoaneurysms of the peripheral arteries

Objective

This study was performed to evaluate the safety and efficacy of endovascular stenting and embolization for the management of radiation-induced peripheral arterial pseudoaneurysms.

Methods

Twelve consecutive patients with radiation-induced peripheral arterial pseudoaneurysms (diameter of 10–30 mm and mean size of 20.42 mm) were admitted to our hospital from 1 January 2015 to 31 October 2019. The patients’ baseline characteristics, perioperative parameters, device characteristics, and curative effects were systematically recorded and analyzed.

Results

The 12 patients comprised 3 men and 9 women with a mean age of 62.90 ± 13.97 years. The iliac artery was the most commonly involved artery, followed by the subclavian artery. In all patients, the pseudoaneurysms were detected by enhanced computed tomography. Twelve covered stents were deployed (7 or 8 mm in diameter and 50 mm in length). Additional coil embolization was performed in three patients (Patients 8, 9, and 10). The primary and secondary technical success rate was 91.7% and 100%, respectively. Apart from one death caused by rebleeding, no patients developed rebleeding during follow-up.

Conclusion

Endovascular stenting and coil embolization are feasible and effective for the management of radiation-induced peripheral arterial pseudoaneurysms in highly selected patients.

Mycotic right subclavian artery aneurysm: a rare and challenging pathology

Mycotic subclavian artery aneurysms are rare but challenging pathology. We report a 67-year-old woman who presented with recurrent bacteremia secondary to chronic clavicular osteomyelitis. Imaging demonstrated a right subclavian artery aneurysm near the innominate artery bifurcation and in close proximity to the infected clavicle. Owing to the anatomic location, among other factors, she underwent open repair using a rifampin-soaked Dacron conduit. Analysis of the aneurysm wall identified bacteria consistent with intraoperative bone and blood cultures. Contributions from multiple surgical and medical specialties provided a favorable, long-term outcome for the patient.

Treatment of an Infected, Bovine Pericardial Carotid Patch: Excision and Reconstruction with a Superficial Femoral Arterial Interposition Graft

Carotid patch infection is a rare complication but one often associated with severe morbidity, including hemorrhage, stroke, cranial nerve injury, and mortality. We present a case of a gram-negative bacterial infection of a bovine pericardial carotid patch. Treatment ultimately required patch explantation and reconstruction with a femoral arterial interposition graft.