Cryopreserved Arterial Allograft Reconstruction for Infected Peripheral Bypass

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.

Use of Omniflow® II Biosynthetic Graft for the Treatment of Vascular Graft and Endograft Infections

BACKGROUND

Vascular graft/endograft infection is a rare but life-threatening complication of cardiovascular surgery and remains a surgical challenge. Several different graft materials are available for the treatment of vascular graft/endograft infection, each having its own advantages and disadvantages. Biosynthetic vascular grafts have shown low reinfection rates and could be a potential second best after autologous veins in the treatment of vascular graft/endograft infection. Therefore, the aim of our study was to evaluate the efficacy and morbidity of Omniflow® II for the treatment of vascular graft/endograft infection.

METHODS

A multicenter retrospective cohort study was performed to evaluate the use of Omniflow® II in the abdominal and peripheral region to treat vascular graft/endograft infection between January 2014 and December 2021. Primary outcome was recurrent vascular graft infection. Secondary outcomes included primary patency, primary assisted patency, secondary patency, all-cause mortality, and major amputation.

RESULTS

Fifty-two patients were included with a median follow-up duration of 26.5 (10.8-54.8) months. Nine (17%) grafts were implanted in intracavitary position and 43 (83%) in peripheral position. Most grafts were used as femoral interposition (n = 12, 23%), femoro-femoral crossover (n = 10, 19%), femoro-popliteal (n = 8, 15%), and aorto-bifemoral (n = 8, 15%) graft. Fifteen (29%) grafts were implanted extra-anatomically and 37 (71%) in situ. Eight patients (15%) presented with reinfection during follow-up, most of these patients received an aorto-bifemoral graft (n = 3, 38%). Intracavitary vascular grafting had a 33% (n = 3) reinfection rate and peripheral grafting 12% (n = 5; P = 0.025). The estimated primary patencies at 1, 2, and 3 years were 75%, 72%, and 72% for peripherally located grafts and 58% (at all timepoints) for intracavitary grafts (P = 0.815). Secondary patencies at 1, 2, and 3 years were 77% (at all timepoints) for peripherally located prostheses and 75% (at all timepoints) for intracavitary prostheses (P = 0.731). A significantly higher mortality during follow-up was observed in patients who received an intracavitary graft compared to patients with a peripheral graft (P = 0.003).

CONCLUSIONS

This study highlights the efficacy and safety of the Omniflow® II biosynthetic prosthesis for the treatment of vascular graft/endograft infection, in absence of suitable venous material, with acceptable reinfection, patency, and freedom of amputation prevalences, especially in replacing peripheral vascular graft/endograft infection. However, a control group with either venous reconstruction or another alternative graft is needed to make firmer conclusions.

Contemporary results with the biosynthetic glutaraldehyde denatured ovine collagen graft (Omniflow II) in lower extremity arterial revascularization in a septic context

OBJECTIVE

Prosthetic peripheral vascular graft infections are poorly evaluated, despite a grim prognosis with high mortality and major amputation rates. The vascular substitute of choice remains controversial when autologous veins are unavailable. The main objective of this study was to evaluate the mid-term results of a new alternative biosynthetic collagen graft (Omniflow II®) in an infected field in patients with unavailable or unsuitable autologous saphenous vein.

METHODS

This retrospective, observational, multicentric study included all consecutive patients in whom an Omniflow II® graft was used for infra-inguinal revascularization in the context of sepsis from January 2015 to January 2020. The primary endpoint was freedom from major amputation; secondary endpoints were 30-day mortality, perioperative morbidity, and estimated survival, patency, and freedom from reinfection estimated using the Kaplan-Meier method.

RESULTS

Twenty-nine patients (27 men, median age 69 years (IQR:60;76) were included. Fever was present in 58.6% of cases, a septic rupture in 17.9%, and a pseudo-aneurysm in 25.0%. The 30-day mortality rate was 3.4% (septic shock). The median follow-up reached 49 months. At 1 and 3 years, the estimated freedom from major amputation was 88.4% and 83.9%, survival was 96%, primary patency was 74.6% and 65.8%, secondary patency was 82.1% and 77.7% and reinfection free-survival was 85.6%. There were 7 occlusions (1 iliofemoral, 1 below-knee, and 5 above-knee bypasses), 3 explantations for persistent sepsis, 4 reinfections (all within the first 6 months which led to 1 death and 3 major amputations), and a total of 4 major amputations. The risk of major amputation increased with bypass reinfection (p=.004), occlusion (p=.005), and polymicrobial infection (p=.05).

CONCLUSION

In a septic context, the Omniflow II® bioprosthetic graft represents an acceptable vascular substitute in the absence of an autologous vein. It provides acceptable freedom from major amputation and reinfection considering the seriousness of this pathology. This usage remains outside the instructions for use, it is, therefore, essential to pursue longer-term studies in larger cohorts.

Peripheral artery reconstructions using cryopreserved arterial allografts in infected fields

OBJECTIVE

Cryopreserved 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.

METHODS

A 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).

RESULTS

A 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).

CONCLUSIONS

A 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.

Postmortem Retrieval of Arterial Allografts: Preliminary Results

BACKGROUND

Cryopreserved arterial allografts are vascular substitutes used for arterial reconstructions in a septic field. Their use remains however limited by the shortage of donors. One of the possibilities to address this lack of grafts is to multiply the sources of retrieval. The objective of this preliminary study was the evaluation of the early clinical results and the microbiological safety of arterial grafts retrieved after death.

METHODS

In addition to the standard conditions of arterial sampling, the criteria of inclusion for postmortem retrieval comprised the refrigeration of the body of the donor within 4 hr following the death, a 24-hr time limit from the death, and the availability of an adapted place for retrieval (surgical unit or death chamber respecting the required aseptic conditions). We only retrieved the femoral axes (FAs) and the aortoiliac bifurcation. The conditions of retrieval, transportation, preparation, and conservation were identical to those of cryopreserved arterial allografts harvested during standard multiple organs retrieval. We evaluated the bacteriological risk of contamination and the patency of the grafts in the short and medium term.

RESULTS

In 2015 and 2016, 6 donors were included. Eleven FAs and 2 aortic bifurcations were harvested. The bacteriological samples done on arrival in bank and after thawing were negative in the 6 donors, but one of the 6 donors presented a bacterial contamination of other removed tissues, and the arterial grafts obtained from this donor were destroyed as a precaution (3 grafts). The quality of the grafts evaluated by the surgeon during harvesting was good in all the cases. The indications of allografts were arterial reconstruction in a septic field (n = 8) and aorto-hepatic bypass during hepatic transplantation (n = 1). One graft was unhopefully thawed without being used. At the end of the follow-up, 8 out of 9 grafts were patent. Two ruptures occurred in a context of locally persistent sepsis (crural abscess due to Salmonella typhi and persistent groin wound disunion with a polymicrobial flora). One allograft thrombosis was observed (aorto-hepatic bypass for transplantation). These complications were unrelated to the mode of graft harvesting. No aneurysmal evolution was observed.

CONCLUSIONS

The preliminary results of this protocol are encouraging because the immediate quality of the grafts was good with a risk of microbiological contamination identical with that of the usual harvesting mode. This mode of harvesting looks promising to reduce the shortage in arterial allografts and could be extended to harvest thoracic aortic allografts. However, results at a larger scale are necessary to confirm these data.

Management and Outcome of Prosthetic Vascular Graft Infections: A Single Center Experience

Background:

Prosthetic vascular graft infection (PVGI) remains a severe and challenging complication in vascular surgery with high morbidity and mortality rates. Incidence has been reported between 1% and 6%. The aim of this study was to report our experience in terms of general and surgical management as well as outcome, over 15 years.

Methods:

A retrospective consecutive study was conducted of all patients treated in our department for PVGI between January 2000 and December 2015. We analyzed all data relative to primary operation, duration interval between initial surgery and infections signs, infection site, type of microorganism involved, and surgical treatment modality, as well as evaluation of short- and long-term results.

Results:

Sixty-two patients were admitted for PVGI. Primary revascularization procedures consisted of a peripheral bypass in 42 (68%) patients and an aortic bypass in the remaining 20 (32%) patients. Median interval between primary procedure and reintervention was 3 months (interquartile range 17 [IQR 17]) in the peripheral group and 48 months (IQR 70.5) in the aortic group. Complete excision of the prosthetic graft was carried out in 85% of the cases. Thirty-day mortality was 0% and 9.5% in the aortic and peripheral group, respectively. The overall survival rate was 62.3% at 2-years, 46.4% in the aortic group, and 69.7% in the peripheral group.

Conclusions:

Prosthetic vascular graft infection needs a multidisciplinary management with appropriate antibiotherapy, radical removal of the infected graft, and in situ reconstruction. This strategy gives satisfactory results in terms of mortality, morbidity, patency rates, and infection control.

Late Fate of Cryopreserved Arterial Allografts

OBJECTIVE

Initial enthusiasm for use of cryopreserved arterial allografts was subsequently tempered by suboptimal long-term outcome. Thrombosis, anastomotic pseudo-aneurysm, allograft disruption, aneurysmal degeneration, recurrent intestinal fistulization, and persistent infection are commonly reported in series with long-term follow-up. The authors reviewed their experience over the past 15 years with the use of cryopreserved arterial allografts as a vascular substitute for vascular prosthetic infection or for primary arterial infection, to investigate allograft-related complications.

MATERIAL AND METHODS

A retrospective analysis of prospectively collected data was conducted for 103 cryopreserved arterial allografts inserted in 96 patients between July 2000 and July 2015. There were 78 patients with infected vascular prosthesis (IVP), nine patients with an aorto-enteric fistula (AEF), and nine patients with primary arterial infection (PAI).

RESULTS

The in-hospital mortality was eight out of 78 (9%) IVP patients, three out of nine AEF patients, and zero out of nine PAI patients. Median follow-up was 49 months. Allograft-related re-interventions were necessary in 29% of the patients with IVP and four of the patients with AEF, but none of the patients with PAI. Five-year survival for the IVP, AEF, and PAI patients was 53%, 44%, and 90%, respectively.

CONCLUSION

This series highlights some shortcomings of cryopreserved arterial allografts in the long term, including suboptimal outcome-results and shortage of material. The authors discuss the allograft-related complications and suggest some tricks to minimize their risk.

Use of cryopreserved cadaveric arterial allograft as a vascular conduit for peripheral arterial graft infection

Major peripheral arterial graft infection is a potentially devastating complication of vascular surgery, associated with significant mortality and high amputation rates. Autologous saphenous veins are considered optimal arterial conduits for lower extremity revascularization in infected fields, but they are often unavailable or unsuitable in these patients. This study describes two patients with major peripheral graft infection, but without available autologous veins, who underwent graft excision and cryopreserved cadaveric arterial allograft reconstruction. Although long-term graft durability is unclear because of gradual deterioration and degeneration, these findings suggest that cadaveric allografts may be good options for patients with major peripheral graft infection.

Diagnosis and management of abdominal vascular injuries

Intra-abdominal vascular trauma is an injury that continues to challenge the general surgeon and leads to high morbidity and mortality even at busy urban trauma centers. The majority of patients arrive in hemorrhagic shock; therefore, rapid evaluation, resuscitation, and transfer to the operating room are necessary to treat these patients. In the operating room, the surgeon must have a well-planned surgical approach to the variety of potential injuries encountered in the retroperitoneal space. This article reviews the incidence, diagnostic strategies, treatment principles, and expected outcomes when dealing with intra-abdominal vascular injury.