Rhabdomyolysis in the Etiology of Renal Failure Following Thoracoabdominal Aortic Aneurysm Repair

Background: Renal failure following thoracoabdominal aortic aneurysm repair is a widely reported complication. Although this has been attributed to end-organ ischemia, we hypothesized that rhabdomyolysis might be an important etiologic factor. We followed serum creatine phosphokinase (CPK) and serum myoglobin levels prior to surgery and for fifteen days postoperatively to examine this question.
Methods: Between August 2006 and May 2007, we followed CPK and myoglobin in 67 consecutive patients who underwent thoracic or thoracoabdominal aortic repair. Mean age was 62 (range 29-89 years), and 23/67 (34%) were female. Upper limit of normal is 198 U/L for CPK and 85 ng/ml for serum myoglobin.
Results: Preoperatively, mean serum myoglobin was 49.4 +/- 29.5 ng/ml and 104.9 +/- 123.7 U/L for CPK. Immediately postoperatively, serum myoglobin rose to 1311.5 +/-1280 ng/ml, and CPK rose to 1200.8 +/- 683 U/L. On postoperative days 1, 2 and 3, serum myoglobin was 2244.5, 2509.4 and 1797.7 ng/ml, while serum CPK was 2110.1, 2636.0 and 2600.2 U/L for the same time period. These were all highly statistically significantly elevated above baseline and were beyond 10 times the upper limit of normal. Values reached peak on the second postoperative day. Patients who developed renal failure had serum myoglobin values beyond the day of surgery that were at least double those of the patients without renal failure (p<0.0003).
Conclusions: This observation presents strong evidence that rhabdomyolysis occurs following thoracoabdominal aortic aneurysm repair, and that it plays a significant role in the etiology of postoperative renal failure. Timing of clinically apparent renal failure is coincident with peak serum myoglobin levels.