Ann Thorac Surg 1991:52:569-71

DELEON ET AL 571 RESTERNOTOMY IN VALVED CONDUITS

be required for outgrown and degenerated conduits [%6]. Kirklin and colleagues [7] reported that 40% of xenografts or irradiated allografts would require replacement within 10 years of implantation.

The location of the valved conduit in relation to the sternum and the age of the conduit will determine the safety of resternotomy. The valved conduit in severe forms of tetralogy of Fallot, such as pseudotruncus, is usually located to the left side of the sternum, thus making resternotomy relatively safe. The valved conduit in transposition of the great arteries, truncus arteriosus, and Taussig-Bing anomalies often passes under the ster- num and will pose some difficulties on reoperation. Valved conduits are now rarely used for the atrioventric- ular or pulmonary connection in patients with univentric- ular heart undergoing the Fontan operation [B].

Reoperation on patients with valved conduits carries significant morbidity and mortality rates. Schaff and col- leagues [l] reported an 18% (18/100) incidence of hemor- rhage as a result of laceration of the myocardium or injury to the conduit in patients undergoing replacement of obstructed pulmonary ventricle to pulmonary artery con- duit. Institution of cardiopulmonary bypass was accom- plished through the femoral artery in 68% of patients. They reported a 7% mortality. None of the deaths were directly attributed to intraoperative conduit injury, al- though when stratified by diagnosis the mortality rate was 25% among patients with truncus arteriosus, where there is a high possibility of the conduit passing under the sternum. Boyce and colleagues [3] reported an 18% (5/28) mortality rate in patients undergoing replacement of 12-mm porcine valved conduit from the right ventricle to the pulmonary artery. Although the direct cause of death was not clearly reported, 78% of their patients had trun- cus arteriosus.

Several surgical approaches are available to patients

with valved conduits adherent to the sternum. Cardiopul- monary bypass can be accomplished through the femoral vessels followed by resternotomy, or resternotomy can be initially performed with cardiopulmonary bypass insti- tuted through the femoral vessels in the event of diffi- culties. The technique we describe provides an alternative approach to patients with valved conduits adherent to the sternum that might minimize conduit injury and neoin- timal collapse.

References 1. Schaff HV, Di Donato RM, Danielson GK, et al. Reoperation

for obstructed pulmonary ventricle-pulmonary artery con- duits. Early and late results. J Thorac Cardiovasc Surg 1984;88: 33443.

2. DeLeon SY, LoCicero J 111, Ilbawi MN, Idriss FS. Repeat median sternotomy in pediatrics: experience in 164 consecu- tive cases. Ann Thorac Surg 1986;41:184-8.

3. Boyce SW, Turley K, Yee ES, Verrier ED, Ebert PA. The fate of the 12 mm porcine valved conduit from the right ventricle to the pulmonary artery. J Thorac Cardiovasc Surg 1988;95: 201-7.

4. Agarwal KC, Edwards WD, Feldt RH, Danielson GK, Puga FJ, McGoon DC. Clinicopathological correlates of obstructed right-sided porcine-valved extracardiac conduits. J Thorac Cardiovasc Surg 1981;81:591-601.

5. Saravalli OA, Somerville J, Jefferson KE. Calcification of aortic homografts used for reconstruction of the right ventricular outflow tract. J Thorac Cardiovasc Surg 1980;80:909-920.

6 . Ciaravella JM, McGoon DC, Danielson GK, Wallace RB, Mair DD. Experience with the extracardiac conduit. J Thorac Car- diovasc Surg 1979;78:92&30.

7. Kirklin JW, Blackstone EH, Maehara T, et al. Intermediate- term fate of cryoreserved allograft and xenograft valved con- duits. Ann Thorac Surg 1987;44:598-606.

8. DeLeon SY, Ilbawi MN, Idriss FS, et al. Fontan type operation for complex lesions: surgical considerations to improve sur- vival. J Thorac Cardiovasc Surg 1986;92:1029-37.

INVITED COMMENTARY This report recommends a technique that has been effec- tive in five operations. Reoperations of this type are hazardous, and the authors’ overall results in 22 patients are excellent with and without the sternal sculpturing herein described. The dangers of this technique are obvi- ous from the illustrations, and its ”safety” is certainly unproved at this time. It does, however, seem reasonable

to present the technique as an expansion of the surgeon’s armamentarium in dealing with this difficult situation.

A,ztjlony R, c, Dobell, M D

The Montreal Children’s Hospital 2300 Tupper St , Rm C-1139 Montreal, Que H3H 1P3 Canada