Open and endovascular repair of infected femoral artery pseudoaneurysms in intravenous drug abusers: results from the Italian "IN-FEMS" (INfected Femoral artery psEudoaneurysMs in drug addictS) multicentric Registry

Objective: Infected femoral artery pseudoaneurysms (IFAPs) are threatening complications of voluntary drug injections in the groin. The purpose of this study is to report the results of open and endovascular repair of IFAPs in intravenous drug abusers. Methods: The IN-FEMS (INfected Femoral artery psEudoaneurysMs in drug addictS) is a physician-initiated, multicenter and retrospective registry of patients treated for native IFAPs between 2010 and 2023 in 18 different Italian Vascular Surgery Departments. Primary endpoints included perioperative death rates, surgical reconstructions durability, major amputation rates and reintervention rates. Additionally, antimicrobial activity of different biological and synthetic vascular grafts was tested using agar plates seeded with methicillin-resistant staphylococcus aureus. Results: 100 consecutive procedures (94 patients, 6 with bilateral IFPAs) were included in the study. Two groups were analized: open repair group (A, n= 83) and endovascular repair group (B, n= 17). Medium age of the patients was 41.7 ± 9.2, with a high percentage of patients positive for drug related infectious diseases. The most frequent surgical procedures included common femoral artery (CFA) reconstruction with a single straight tube (n= 24, 24.0%), followed by external iliac artery (EIA) - CFA bypass (n= 18, 18.0%). 8 patients were treated with arterial ligation (8%). 12 (12.0%) patients received a stenting of the EIA-CFA. Perioperative death rate was 2.0%. The overall survival rate after 48 months was 76.5% (standard error 0.06). A statistically significant difference in terms of grafts durability was observed among 3 subgroups of patients treated with open surgery with different conduits (autologous vein/cryopreserved allografts; pericardium/biosynthetic composite grafts; prosthetic grafts - respectively 78.4%, 80% and 33.5%; log rank p=0.024). Major amputation was similar for both open and endovascular groups (respectively 1.2% and 5.9%, p= .313). A significant difference was observed in terms of reintervention rates: group A showed a lower rate of reinterventions compared with group B (37.4% vs 64.7%, p= .037). Microbiological evaluation showed that autologous great saphenous vein (GSV) and reinforced cryopreserved saphenous vein (CSV) present a strong intrinsic antimicrobial activity compared to prosthetic grafts. Conclusions: Endovascular repair appears a technically feasible solution that doesn't compromise the limb salvage rates; however, the reintervention rates are significantly higher in patients treated with endovascular techniques, which should be considered as "bridge therapy". Open surgery seems to be the safest and most durable solution to treat these complex cases. The use of synthetic grafts should be limited to those patients "without alternative options", when autologous or biosynthetic materials are not available.