Optimal end-organ protection for thoracic and thoracoabdominal aortic aneurysm repair using deep hypothermic circulatory arrest

Background. Despite the advent of numerous protective strategies, thoracic and thoracoabdominal aortic replacement remains a high risk. While mortality rates have improved over the last 15 years, the incidence of adverse outcomes (including stroke, renal failure, and paraplegia, as well as death) remains at 13% to 30% in all published series. The use of deep hypothermic cardiopulmonary bypass with circulatory arrest has been associated with high morbidity in the past; however, we report a single surgeon's experience of improved endorgan protection with low morbidity and mortality utilizing this technique. Methods. One hundred seventy-three consecutive patients with descending thoracic and thoracoabdominal aneurysms were operated on between April 1995 and March 2005. Hypothermic (15 degrees C) cardiopulmonary bypass with circulatory arrest and open proximal anastomosis were utilized in all subjects. Visceral arteries were uniformly reimplanted as an island while additional renal artery bypasses were performed as required. Lower intercostals and lumbar arteries were aggressively reimplanted or pre-served at the aortic anastomosis. No other adjuncts for spinal cord protection were routinely employed. Results. Sixty-three patients with isolated descending thoracic aortic aneurysms and 27 patients with extent I, 49 with extent II, 20 with extent III, and 14 with extent IV thoracoabdominal aortic aneurysms underwent operative repair. Ninety percent of cases were elective while 10% were urgent or emergent. There were seven hospital deaths, and the hospital mortality was 4.0%. Operative complications included stroke in seven patients (4.1%), paraplegia in four (2.4%), including 0 of 62 ambulatory patients with isolated thoracic aneurysm repairs, and acute renal failure requiring dialysis in two of 168 operative survivors that were not dialysis-dependent before surgery. Conclusions. Deep hypothermic circulatory arrest allows replacement of complex aortic pathology with low mortality. End-organ protection is excellent with lower incidences of dialysis-dependent renal failure and paraplegia than are reported with other currently used surgical techniques.