To characterize the inflammatory and coagulopathic response after endovascular thoracoabdominal aortic aneurysm (TAAA) repair and to evaluate the effect of the response on post-operative renal function.
From 7/2005 to 6/2008, 42 patients underwent elective endovascular repair of a TAAA using custom designed multi-branched stent-grafts at a single academic institution. 4 patients were excluded from the analysis. White blood cell count (WBC), platelet count, prothrombin time (PT), and creatinine were measured in all patients. In the last 9 patients, interleukin-6 (IL-6), protein C, Factor V, d-dimers, cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL) levels were also measured. Change in lab values were expressed as a percentage of baseline values.
The 30-day mortality rate was 5% (2/38). All patients (n=38) had a higher WBC (mean±SD: 139 ± 80%, P<0.0001), lower platelet count (56 ± 15%, P<0.0001), and higher PT (median: 17%, IQR 12 - 22%, P<0.0001) after stent-graft insertion. Twelve of 38 patients (32%) developed postoperative acute renal insufficiency (>50% rise in creatinine). Patients with renal insufficiency had significantly larger changes in WBC (178 ± 100% vs 121 ± 64%, p=0.04) and platelet count (64 ± 17% vs 52 ± 12%, p=0.02) compared to those without renal insufficiency. All patients (n=9) had significant increases in NGAL (182 ± 115%, p=0.008) after stent-graft insertion. 6/9 patients (67%) had increased cystatin C (35 ± 43%, p = 0.04) after stent-graft insertion, with a greater rise in those with postoperative renal insufficiency (87 ± 32% vs 8 ± 13%, p = 0.02). IL-6 levels were markedly increased in all patients (n=9) after repair (9,840 ± 6,160%, p=0.008). Protein C (35 ± 10%, p=0.008) and Factor V levels (28 ± 20%, p=0.008) were uniformly decreased, while d-dimers were elevated after repair in all patients (310 ± 213%, p=0.008).
Leukocytosis and thrombocytopenia were uniform following endovascular TAAA repair, and the severity of the response correlated with post-operative renal dysfunction. Elevation of a sensitive marker of renal injury (NGAL) suggests that renal injury may occur in all patients after stent-graft insertion.