Surgery of acute type A dissection: what have we learned during the past 25 years?

Every acute dissection involving the ascending aorta (Stanford type A) must undergo emergency surgical repair. However, the surgical techniques must vary according to the clinical presentation of the patients or the anatomical patterns observed. Furthermore, surgery is generally difficult because of the poor condition of the aortic tissues. To reduce those difficulties many technical artifacts have been described. In 1977, we proposed the use of gelatin-resorcin-formalin (GRF) biological glue to reinforce the suture areas. From January 1977 to July 1999, 212 patients (pts) (152 males and 60 females) aged from 15 to 80 years (mean age: 54 +/- 11 years) underwent an emergency operation for type A aortic dissection. One-hundred-seventy-eight pts (84%) were operated on within 4 hours after being referred to the hospital. Twenty-eight pts (13.2%) had Marfan's syndrome. In 44 patients (20.7%), the aortic valve was replaced either independently (6 cases--2.8%) or by means of a composite graft (38 cases--17.9%). Because of the location of the intimal tear, the aortic replacement was extended to the transverse arch in 61 pts (28.7%). Hospital mortality amounts to 21.6% (46 pts), 25% in pts with arch replacement and 19.4% in pts without arch replacement (n.s). Analysis of hospital mortality demonstrates that the main causes of death were cardiac tamponade, neurologic disorders and visceral malperfusion. One-hundred-sixty-six pts were discharged and surveyed from 5 months to 22 years postoperatively (mean follow-up: 85 +/- 66 months). During this period of time, 25 pts (15%) had to be reoperated for a total of 33 reoperations. Seven pts (28%) died at reoperation. Using univariate analysis, the presence of Marfan's syndrome (p < 0.05) and absence of arch replacement (p < 0.02) were determinant risk factors for reoperation. Emergency (p < 0.01) and thoraco-abdominal replacement (p < 0.04) were determinant riskfactors for death at reoperation. The freedom from reoperation (Kaplan-Meier, CI: 95%) is 96% (90-98), 87% (79-92), 80% (70-88), 66% (51-78) at 1, 5, 10 and 15 years respectively. A total of 39 pts (24.3%) died during follow-up. The presence of Marfan's syndrome (p < 0.01), reoperation (p < 0.02), stroke (p < 0.05), and cardiac failure (p < 0.05) were determinant risk factors of late mortality. The late survival rate (K-M. C.I.: 95%), including hospital mortality, is 71% (64-77), 66% (58-73), 56% (47-64), 46% (36-56), 37% (28-44) at 1, 10, 15 and 20 years, respectively. From our experience extending over more than 23 years, GRF glue has proved to be extremely useful, making the procedure much easier and safer. Nevertheless, many factors are of importance in the pre-, intra- and postoperative management of the patients. Cardiac tamponade and visceral malperfusion must be properly diagnosed and treated. During aortic repair, the main intimal tear must be resected. The transverse arch must be checked and replaced whenever necessary. The aortic valve should be preserved whenever possible. During CPB, perfusing the aorta in the regular antegrade manner seems to dramatically reduce the rate of malperfusion. The quality of the first emergency operation seems to have a major influence on the late results, especially concerning the rate of late reoperations and aortic ruptures. However, those late results depend also on the patient's basic condition, particularly in Marfan patients.