Impact of left heart bypass on the results of thoracoabdominal aortic aneurysm repair

Background. This study evaluated the role of left heart bypass on the resul ts of thoracoabdominal aortic aneurysm (TAAA) operations. Methods. Two hundred fifty-eight patients had surgical repair of a thoracoa bdominal aortic aneurysm between 1981 and 1998 using the inlay technique. S imple crossclamping was used in 47.7% and left heart bypass (atriodistal) i n 52.3%. Further surgical technique was identical: liberal intercostal or l umbar artery reimplantation, cerebrospinal fluid drainage (since 1989), adm inistration of a renal cooling solution, permissive mild hypothermia, and n o pharmacologic protection. Both univariate and multivariate analysis were used. Results. The hospital mortality rate was 10.1% overall: 14.6:% in the cross -clamp group, and 5.9% in the bypass group (p = 0.02). The risk of hospital death increased with aneurysm rupture (odds ratio 5.6) and when the patien t needed postoperative dialysis (odds ratio 7.5). The use of left heart byp ass had a mild protective effect on hospital death (odds ratio 0.56). The i ncidence of postoperative renal failure requiring dialysis was 8.3% overall : 10.9% in the cross-clamp group, and 5.9% in the bypass group (p 0.16). Af ter multivariate analysis, a longer operative procedure (odds ratio 1.01 pe r minute) and a longer reappearance time of blue dye in the urine (odds rat io 1.05 per minute) increased the risk of dialysis, whereas the use of atri odistal bypass reduced that risk (odds ratio 0.08). Paraplegia or parapares is occurred in 10.9% of patients overall: 13.2% in the cross-clamp group, a nd 8.8% in the bypass group (p = 0.27). After logistic regression, rupture increased the risk of paraplegia or paraparesis (odds ratio 3.2) and dissec tion reduced it (odds ratio 0.23). Conclusions. The use of atriodistal bypass is beneficial in patients who ha d thoracoabdominal aortic aneurysm repair. Hospital mortality rates, postop erative dialysis, and paraplegia/paraparesis were reduced. (C) 1999 by The Society of Thoracic Surgeons.