Fontan Operation in 176 Patients with Tricuspid Atresia. Results and a Proposed New Index for Patient Selection

Between 1973 and March 1989, 176 patients with tricuspid atresia had the Fontan procedure performed at the Mayo Clinic. Age range at the time of surgery was 7 months to 42 years, with 43 patients (24%) 16 years old or older. Hospital mortality rates were 17% (nine of 54) from 1973 through 1980 and 8% (10 of 122) from 1981 through 1989. There have been 10 late cardiovascular deaths. Postoperative follow-up of 139 survivors (range, 6 months to 14 years; mean, 5.5 years) revealed 91% to be in excellent or good condition and 9% to be in fair or poor condition. Patients in fair or poor condition had poor stamina and/or fluid retention with intermittent pleural effusion, ascites, and so on. Two factors that clearly influence operative and late results are preoperative pulmonary arteriolar resistance (Rpa) and left ventricular diastolic function. A preoperative catheterization index devised by adding Rpa to left ventricular end-diastolic pressure divided by QpI plus QsI may be helpful in selecting candidates most likely to survive and benefit from the Fontan operation. In our experience, if this index is less than 4.0, then the postoperative right atrial mean pressure will be 20 mm Hg or less, a circumstance associated with 95% early and 89% overall survival rates.