Safe aortic arch clamping in patients with patent internal thoracic artery grafts.

In patients who have undergone coronary artery bypass with a left internal thoracic artery graft, clamping the aorta proximal to the left subclavian artery during descending thoracic and thoracoabdominal aortic aneurysm repair can precipitate major cardiac complications. Many centers use hypothermic circulatory arrest to obviate the need for aortic clamping in these cases. Herein, we describe the successful application of an alternative approach to this problem: performing left carotid-subclavian bypass before aneurysm repair. This technique allows aortic cross-clamping proximal to the left subclavian artery, prevents major intraoperative cardiac complications, and avoids cardiopulmonary bypass and hypothermic circulatory arrest.

Randomized comparison of cold blood and cold crystalloid renal perfusion for renal protection during thoracoabdominal aortic aneurysm repair.

OBJECTIVE: More effective adjuncts are needed to reduce the incidence of acute renal injury after thoracoabdominal aortic aneurysm (TAAA) repair. The purpose of this randomized trial was to determine whether renal perfusion with cold blood provides better protection against renal ischemia than perfusion with cold crystalloid in patients undergoing TAAA repair with left heart bypass. METHODS: One hundred seventy-two patients were enrolled. Strict inclusion criteria were used, including planned Crawford extent II or III TAAA repair with left heart bypass. The patients were randomly assigned to receive intermittent renal perfusion with either 4 degrees C lactated Ringer's solution (n = 86) or 4 degrees C blood (n = 86). Renal complications within 10 days of operation were stratified by renal dysfunction score (RDS). Postoperative changes in the levels of five urinary biomarkers-retinol binding protein, alpha-1 microglobulin, microalbumin, N-acetyl-beta-D-glucosaminidase, and intestinal alkaline phosphatase-were compared to assess potential differences in subclinical renal injury. RESULTS: Although total ischemic times were longer in the cold blood group, unprotected ischemic times were similar between the two groups. Twenty-seven patients in the cold blood group (31%) and 21 patients in the cold crystalloid group (24%) had peak RDS >or=2 (serum creatinine >50% above baseline; P = .4). There were no differences between the cold blood and cold crystalloid groups in the incidence of early death (7/86 [8%] vs 5/86 [6%], respectively; P = .8) or renal failure requiring hemodialysis (3/86 [3%] in both groups). Changes in renal biomarker levels were also similar in the two groups. Spinal cord deficits developed in 5 patients in the cold blood group (6%); there were no such deficits in the cold crystalloid group (P = .06). CONCLUSION: Cold renal perfusion during TAAA repair provides effective protection against renal injury. Using cold blood instead of cold crystalloid does not enhance renal protection.