Frequency, risk factors, and management of perigraft seroma after open abdominal aortic aneurysm repair

Objective Perigraft seroma (PGS) causing enlargement of the native aneurysm sac after open abdominal aortoiliac aneurysm (AAA) repair is a rarely recognized complication with unknown clinical consequences. This study was undertaken to determine the frequency of PGS, identify associated risk factors, and review resulting complications and their management strategies. Methods Charts of all patients who underwent open AAA repair at our institution from 1995 to 2009 and had at least one postoperative abdominal cross-sectional imaging study (the study subjects) were retrospectively reviewed. PGS was defined as a perigraft fluid collection present >3 months postoperatively, ≥3-cm in diameter and having a radiodensity ≤25 Hounsfield units on computed tomography (CT). Patient records were reviewed for demographics, comorbidities, operative and postoperative variables, and long-term outcome. Results Of the 111 study subjects identified, 13 had aortic reconstruction with Dacron grafts and 98 with polytetrafluoroethylene (PTFE) grafts. Twenty patients (18%) had PGS, all of whom had PTFE grafts (20 of 98; 20.4%). Mean age was 68.5 years and mean aneurysm diameter preoperatively was 6.4 cm (range, 4.0-10.9 cm). The average time from AAA repair to PGS detection was 51 months (range, 4-156 months). PGS averaged 6.0-cm in diameter (range, 3.0-11.0 cm). Multivariate analysis revealed that the following factors were associated with PGS development: diabetes (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.1-21.2; P = .013), smoking (OR, 5.6; 95% CI, 0.73-33.74; P = .01), anticoagulation (OR, 7.2; 95% CI, 2.6-63.3; P = .003), bifurcated graft reconstruction (OR, 8.0; 95% CI, 2.6-94.1; P = .017), and left flank retroperitoneal approach for repair (OR, 7.1; 95% CI, 1.9-26.5; P = .003). Four patients (4 of 20; 20%) required intervention for PGS-related complications: 3 patients for symptomatic PGS expansion (1 patient with rupture) and 1 patient for acute limb ischemia secondary to graft limb compression and thrombosis. Two patients had open exploration, sac evacuation/reduction, and graft replacement with a Dacron graft: 1 patient for a ruptured aneurysm sac and 1 patient for persistent pain associated with sac enlargement. A third patient underwent a failed CT-guided drainage for abdominal pain and was subsequently treated with partial graft excision. The patient with acute limb ischemia was treated with catheter-directed thrombolysis and graft limb stenting. Conclusion PGS after open AAA repair occurs more frequently than previously reported. Complications requiring intervention can occur in up to 20% of patients with PGS. A variety of treatment modalities can be used to deal with the complications. Earlier CT surveillance is advised after open AAA repair with a PTFE graft if symptoms are suggestive of PGS development.