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.

Significance and current approaches to vascular graft infection

Vascular graft/endograft infection (VGEI) is a constant in cardiovascular surgery with published rates between 1 and 5%. Every graft type and anatomical location is a potential target for infectious complications. These patients are sick patients with high frailty burden. Management of VGEI entails a multidisciplinary and multimodality approach. Here we review some aspects of the problem of VGEI including prevention, diagnosis, and surgical therapy with focus on recent developments in the field.

Cryopreserved arterial allografts vs rifampin-soaked Dacron for the treatment of infected aortic and iliac grafts

OBJECTIVE

Aortic and iliac graft infections remain complex clinical problems with high mortality and morbidity. Cryopreserved arterial allografts (CAAs) and rifampin-soaked Dacron (RSD) are options for in situ reconstruction. This study aimed to compare the safety and effectiveness of CAA vs RSD in this setting.

METHODS

Data from patients with aortic and iliac graft infections undergoing in situ reconstruction with either CAA or RSD from January 2002 through August 2022 were retrospectively analyzed. Our primary outcomes were freedom from graft-related reintervention and freedom from reinfection. Secondary outcomes included comparing trends in the use of CAA and RSD at our institution, overall survival, perioperative mortality, and major morbidity.

RESULTS

A total of 149 patients (80 RSD, 69 CAA) with a mean age of 68.9 and 69.1 years, respectively, were included. Endovascular stent grafts were infected in 60 patients (41 CAA group and 19 RSD group; P ≤ .01). Graft-enteric fistulas were more common in the RSD group (48.8% RSD vs 29.0% CAA; P ≤ .01). Management included complete resection of the infected graft (85.5% CAA vs 57.5% RSD; P ≤ .01) and aortic reconstructions were covered in omentum in 57 (87.7%) and 63 (84.0%) patients in the CAA and RSD group, respectively (P = .55). Thirty-day/in-hospital mortality was similar between the groups (7.5% RSD vs 7.2% CAA; P = 1.00). One early graft-related death occurred on postoperative day 4 due to CAA rupture and hemorrhagic shock. Median follow-up was 20.5 and 21.5 months in the CAA and RSD groups, respectively. Overall post-discharge survival at 5 years was similar, at 59.2% in the RSD group and 59.0% in the CAA group (P = .80). Freedom from graft-related reintervention at 1 and 5 years was 81.3% and 66.2% (CAA) vs 95.6% and 92.5% (RSD; P = .02). Indications for reintervention in the CAA group included stenosis (n = 5), pseudoaneurysm (n = 2), reinfection (n = 2), occlusion (n = 2), rupture (n = 1), and graft-limb kinking (n = 1). In the RSD group, indications included reinfection (n = 3), occlusion (n = 1), endoleak (n = 1), omental coverage (n = 1), and rupture (n = 1). Freedom from reinfection at 1 and 5 years was 98.3% and 94.9% (CAA) vs 92.5% and 87.2% (RSD; P = .11). Two (2.9%) and three patients (3.8%) in the CAA and RSD group, respectively, required graft explantation due to reinfection.

CONCLUSIONS

Aorto-iliac graft infections can be managed safely with either CAA or RSD in selected patients for in situ reconstruction. However, reintervention was more common with CAA use. Freedom from reinfection rates in the RSD group was lower, but this was not statistically significant. Conduit choice is associated with long-term surveillance needs and reinterventions.

An out of the box treatment for an infected pseudoaneurysm: Deep to superficial femoral artery transposition

An infected pseudoaneurysm is a condition that has become more common in recent years, with the proliferation of endovascular intervention and the use of intravenous drugs. If left untreated, an infected pseudoaneurysm can progress to rupture, which can lead to life-threatening hemorrhage. No clear consensus has been reached among vascular surgeons regarding the management of infected pseudoaneurysms, and the literature describes a wide range of treatment techniques. In the present report, we describe an "out of the box" approach to infected pseudoaneurysms: a superficial femoral artery to deep femoral artery transposition, as an alternative to ligation with or without bypass reconstruction. We also describe our experience with six patients who underwent this procedure with 100% technical success and limb salvage rates. Although we implemented this technique for cases of infected pseudoaneurysms, we believe it can also be applied to other cases of femoral pseudoaneurysms when angioplasty or graft reconstruction is not feasible. However, further research with larger cohorts is warranted.

Risk of non-typhoidal Salmonella vascular infections is increased with degree of atherosclerosis and inflammation: A multicenter study in southern Taiwan

BACKGROUND

Atherosclerosis and vascular inflammatory response have been considered as risk factors for non-typhoidal Salmonella (NTS) vascular infection. The study aims to assess the risk of vascular infection by measuring atherosclerosis severity, NTS vascular infection (NTSVI) score, and serum levels of inflammatory markers in people with NTS bacteremia.

METHODS

A prospective observational study was conducted in two medical centers and two regional hospitals. Adults aged ≥50 years with NTS bacteremia who underwent computed tomography (CT) scan for revealing vascular infections were enrolled. The degree of atherosclerosis was scaled by a calcium score determined by a CT scan. Serum concentrations of inflammatory biomarkers were determined in the patients enrolled in a medical center.

RESULTS

Fourteen (20.3%) of 69 patients with NTS bacteremia had vascular infections. Calcium scores over the thoracic (12,540 vs. 3,261, P = 0.0005) and abdominal (9755 vs. 3,461, P = 0.0006) aorta of those with vascular infections were higher than those without vascular infection. All vascular infections were present in the high-risk group (NTSVI score ≥1), yielding a sensitivity of 100% and specificity of 30.9%. Among 17 low-risk patients (NTSVI score <1), none had vascular infections, resulting in a negative predictive value of 100%. Higher plasma concentrations of IL-1β were detected in the cases of vascular infection than those in the control group (23.6 vs. 1.06 pg/mL, P = 0.001).

CONCLUSION

Atherosclerosis of the aorta which is associated with a positive NTSVI score can predict the occurrence of vascular infections and serum IL-1β could be a biomarker for vascular infection in patients with NTS bacteremia.

Q fever aortic infection causing an aortoduodenal fistula after endovascular aneurysm repair

An aortoduodenal fistula is a rare complication of endovascular aortic aneurysm repair. Q fever infection is known for its vascular tropism, and arterial fistulas have been reported in association with Coxiella burnetii infections. We report the case of a 78-year-old patient who had developed an aortoduodenal fistula secondary to vascular Q fever 5 years after he had been treated with an aortic endograft. Explantation of the endograft, autogenous reconstruction using the neo-aortoiliac system procedure, and duodenal repair were performed as a curative surgical treatment of this serious vascular condition. At the 9-month follow-up examination, the patient showed no signs of recurrent vascular infection and was instructed to complete an 18-month antibiotic regimen.

A case of giant cell arteritis associated with culture-proven Coxiella burnetii aortitis

A case of proven Coxiella burnetii aortitis, possibly associated with giant cell arteritis (GCA), is reported. A 72-year-old man, who is a hunter, presented with weight loss, fever, jaw claudication, and hardened temporal arteries associated with a persistent inflammatory syndrome and arteritis of the whole aorta, including the brachiocephalic arteries, as seen on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography. The diagnosis of GCA was retained, and treatment with prednisolone was started. Given the aneurysm of the abdominal aorta, the patient underwent replacement of the abdominal aorta with an allograft. Histology showed intense chronic arteritis attributed to atherosclerosis with dissection. However, Coxiella burnetii infection was confirmed by serology and then by culture and molecular biology on the surgical specimen. A combination of hydroxychloroquine and doxycycline was added to tapered prednisolone and the outcome was favourable.

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.