REPAIR OF INTERRUPTED AORTIC-ARCH - A 10-YEAR EXPERIENCE

Eighty-two consecutive patients with interrupted aortic arch were refe rred to our institution between 1985 and 1995. Three died before any a ttempt at operation and 79 underwent surgical repair. Median age at op eration was 9 days (range 1 day to 6 Sears) and median weight was 3.0 kg (range 1.8 to 20 kg). All but one were in severe congestive heart f ailure and 31.5% had oliguria or anuria. Preoperative pH varied betwee n 6.8 and 7.4 (median 7.3). Sixty-nine received prostaglandin E(1) inf usion and 54 received mechanical ventilation. Aggressive preoperative ressucitation was necessary in 43 cases. Preoperative transfontanellar echography (performed routinely) since 1987 revealed intracerebral bl eeding in six patients. Type A interrupted aortic arch nas present in 37 cases, 41 patients had type B, and one had type C. Interrupted aort ic arch was associated with single ventricular septal defect in 35 cas es, 24 patients had associated complex heart defects, and 30 had signi ficant subaortic stenosis (six had both subaortic stenosis and complex association). Aortopulmonary window was found in four patients, trunc us arteriosus was found in eight, and transposition of the great arter ies was found In five, double-outlet right ventricle was found in one, single ventricle was found in three, multiple ventricular septal defe cts were found in two and superior-inferior ventricles were found in o ne. Sixty-four patients underwent single-stage repair and 15 underwent multistage repair. Aortic arch repair consisted of direct anastomosis in 59 cases, patch augmentation in eight, and conduit interposition i n 12. Ten patients underwent associated pulmonary artery banding and 1 9 underwent concomitant repair of complex associated lesions. The suba ortic stenosis was addressed by four surgical techniques: myotomy or m yectomy in five patients; creation of a double-outlet left ventricle, aortopulmonary anastomosis, and conduit insertion between the right ve ntricle and pulmonary artery bifurcation in four; no direct attempt to relieve the subaortic stenosis in six; and left-sided ventricular sep tal defect patch in 15. Mean duration of deep hypothermic circulatory arrest, crossclamp time, and cardiopulmonary bypass time were 38.8 +/- 15.6 min, 60.5 +/- 24.7 min, and 143 +/- 40.1 min, respectively. Post operative mortality rate was 18.9% (70% confidence limits 14% to 24.6% ), and overal mortality rate was 31% (70% confidence limits 20.9% to 4 2.2%). The results have improved with time, with an overall operative mortality rate of 12% since 1990. Univariate statistical analysis reve aled that early survival was influenced by preoperative renal function , detection of cerebral bleeding by transfontanellar echography, the n umber of cardioplegic injections, and the date of operation. Multivari ate analysis revealed that preoperative renal function and the number of cardioplegic injections were independent risk factors for early mor tality. Echocardiographic measurements of the left heart-aorta complex with preoperative Z values as low as -4 demonstrated rapid growth aft er repair. In the presence of subaortic stenosis, better survival was obtained with a left-sided patch for ventricular septal defect closure (p < 0.05). Twenty-three patients underwent 26 reoperations for recoa rctations (seven), left bronchial compression (two), second-stage repa ir (eight), right ventricle-pulmonary artery conduit replacement (thre e), and miscellaneous (four). One of the survivors was reoperated on f or subaortic membrane. Survival at 5 years for the entire series was 7 0%. For isolated forms, it was 73.5% (90% for 1990 to 1995), for compl ex forms it,vas 70%, and in the presence of subaortic stenosis it was 60%. In conclusion, interrupted aortic arch remains a surgical challen ge with continually improving results. Early diagnosis with preoperati ve resuscitation and adequate myocardial protection seem extremely imp ortant for further improvements. Associated subaortic stenosis or comp lex lesions can be treated in a single-stage repair with satisfactory medium-term results.