Delayed Conversions after Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVES:
Despite secondary intervention following endovascular abdominal aneurysm repair (EVAR), explant of the endograft (conversion) is sometimes necessary. We reviewed patient outcomes associated with delayed conversion following EVAR from a single center patient registry.
METHODS:
Delayed conversion was defined as open repair occurring greater than 30 days following EVAR. Retrospective analysis of clinical data and medical records for subjects in a prospectively maintained registry was performed to analyze outcomes among patients requiring delayed conversion.
RESULTS:
From 2000 to 2008, 1021 EVARs were performed on 971 patients. Six patients (0.6%) required acute conversion, 5 at the time of the index procedure and are excluded from further analysis. Sixteen patients (1.6%) required delayed conversion post-EVAR, (median 26.8 months, range 2-88 months). Indications for delayed conversion included: expanding aneurysm/ endoleak (n=8), migration with endoleak (n=4), rupture (n=2), and infection (n=2). Among conversions performed for endoleak, seven were relative to Type I endoleak (5 proximal, 2 distal) with one relative to Type II leak. Six patients underwent seven secondary procedures prior to delayed conversion (5-63 weeks later), including iliac extension (n=3), proximal cuff placement (n=2), embolization (n=1) and graft relining (n=1). Transperitoneal, open repair was performed in 15 patients with bifurcated (n=12), or tube (n=3) grafts. One patient presented with rupture and died intra-operatively before a new graft was sewn. Thirteen patients required infrarenal aortic clamp while three required suprarenal clamp. Endograft components were retained in three patients. Post operative complications requiring operative intervention included respiratory failure requiring tracheostomy (n=4), bleeding requiring exploration (n=3), lower extremity ischemia (n=1), and wound infection (n=1). Three patients (18.8%) expired with 30 days.
CONCLUSIONS:
In this series delayed conversion was most often necessary in patients with a proximal type I endoleak, followed by graft migration. Mortality associated with delayed conversion of EVAR remains higher than reported series of primary open aortic aneurysm repair. Continued aneurysm surveillance with attention and treatment of endoleaks or growing aneurysms may reduce the mortality associated with delayed conversion