Postoperative renal failure in thoracoabdominal aortic aneurysm repair with simple cross-clamp technique and 4°C renal perfusion.

OBJECTIVE: Acute renal failure (ARF) is reported in up to 12% of patients after thoracoabdominal aortic aneurysm (TAAA) repair with assisted circulation. ARF increases mortality, reduces quality of life, and increases length of hospital stay. This study analyzes ARF after TAAA repair done without assisted circulation.

METHODS: A retrospective analysis of all patients treated for TAAA from 2000 to 2013 was performed using a concurrently maintained, institutionally approved database. All surgeries used simple cross-clamp technique, with moderate systemic hypothermia (32°-33°C) and renal artery perfusion with 4°C solution. Serum creatinine concentration was measured preoperatively and 1 day, 3 days, 7 days, and 30 days after surgery, and Cockcroft-Gault estimated glomerular filtration rate (eGFR) was calculated. Kidney injury was classified by RIFLE (Risk, Injury, Failure, Loss of kidney function, End-stage renal disease) eGFR criteria. Changes in eGFR, kidney injury, ARF, dialysis, length of stay, mortality, and risk factors for ARF were analyzed with SAS-JMP software (SAS Institute, Cary, NC) for univariate analysis and multivariate modeling.

RESULTS: From 2000 to 2013, 455 patients had TAAA surgery; 116 (25.5%) were acute. Mean preoperative eGFR was 62.3 mL/min. Mean renal ischemia time was 58.9 minutes. Eighteen patients (4%) had ARF; nine (2%) required temporary dialysis, and three (0.66%) required permanent dialysis. In univariate analysis, age, renal ischemia time, acuity, baseline eGFR, previous aortic surgery, surgical blood loss, and return to operating room for bleeding complications were significant for ARF (P < .05). Sex, aneurysm extent by Crawford type, cardiac index and mean arterial pressure after reperfusion, and use of loop diuretics were not significant for ARF. In a stepwise deletion model, acute (P = .0377), previous aortic surgery (P = .0167), return to operating room (P = .0213), and age (P = .0478) were significant for ARF. Surgical blood loss (P = .0056) and return to operating room (P = .0024) were significant for postoperative dialysis in multivariate analysis. Only surgical blood loss was significant for permanent dialysis in a multivariate model (P = .0331).

CONCLUSIONS: Very low ARF after TAAA repair can be achieved by simple cross-clamp technique with moderate systemic hypothermia and profound renal cooling. Age, preoperative eGFR, previous aortic surgery, return to operating room, and surgical blood loss were significant for ARF. Return to operating room for bleeding and surgical blood loss were significant for dialysis. Baseline eGFR <30 mL/min and postoperative dialysis were significant for mortality. Most patients with ARF, even those with temporary dialysis after TAAA repair, recover renal function to near preoperative levels.