Makoto Hanai

The role of a staged approach for high-risk Fontan candidates

The preoperative risk characteristics and surgical outcome were reviewed in 24 patients who underwent a one-stage Fontan procedure (One-stage Group) and in 16 patients who underwent bidirectional cavopulmonary shunt as an interim procedure prior to a subsequent Fontan procedure (Two-stage Group) to clarify the role of the staged approach for high-risk Fontan candidates. There were 2 hospital deaths after the one-stage Fontan, and another 2 after the takedown of the fenestrated Fontan to BCPS in patients considered to be less than ideal candidate because of the presence of 3 or more risk factors. In contrast, among the total of 16 patients in the Two-stage Group who had significantly more risk factors than those in One-stage Group (2.8 +/- 1.4, vs 1.1 +/- 1.2 p < 0.001), 14 patients survived after bidirectional cavopulmonary shunt, and a subsequent Fontan procedure was accomplished in 12 patients of these 14, with 2 operative deaths after the takedown to bidirectional cavopulmonary shunt. The rate of final Fontan completion in the Two-stage Group (10/16, 62.5%) was considered to be reasonable, considering the fact that this patient group essentially includes non-Fontan candidates. Additionally, in the category of high-risk with 3 or more risk factors, the rate of successful Fontan completion was higher in the Two-stage Group than in the One-stage Group (50% vs 25%). In the survivors of the Two-stage Group, the average number of risk factor decreased from 2.7 +/- 1.3 (range 0 to 5) to 1.0 +/- 1.0 (range 0 to 4) after bidirectional cavopulmonary shunt with concomitant procedures (i.e., extended pulmonary artery reconstruction in 8, and repair of atrioventricular valve regurgitation in 4), predominantly due to improved Fontan candidacy, relating to pulmonary and/or ventricular characteristics, and eliminated anatomical risks. In conclusion, the two-stage approach with bidirectional cavopulmonary shunt accompanied by concomitant repair of associated anomaly may be useful to lower the risk enough to allow subsequent Fontan completion in high-risk patients.

Right ventricular dynamic cardiomyoplasty for the univentricular heart with pulmonary hypertension

OBJECTIVES We conducted an acute experimental study to test the feasibility of dynamic cardiomyoplasty in a setting of modified Fontan procedure for univentricular heart with pulmonary hypertension to obtain a possible proxy for high-risk Fontan candidates. METHODS After electrical preconditioning of the left latissimuss dorsi for 6 weeks in 8 dogs, the right ventricular cavity was totally obliterated with concomittent closure of the tricuspid valve and right pulmonary artery. Modified Fontan circulation was established with the aortic homograft anastomosed between the right atrium and pulmonary trunk, incorporated with a pericardial pouch as a compression chamber (neoright ventricle) fixed onto the epicardial surface of the ventricle. After cardiopulmonary bypass termination, a latissimus dorsi was applied to wrap the pericardial pouch and ventricle clockwise and stimulated with a trained-pulse (25 Hz) at 1:1 synchronization ratio with cardiac beats. RESULTS Profound right heart failure was noted during Fontan circulation in increased pulmonary vascular resistance (11 +/- 3.2 Wood units), whereas graft pacing showed significant augmentation of systolic pulmonary pressure by 54 +/- 12%, the mean pulmonary flow by 68 +/- 23%, and aortic pressure by 23 +/- 5% at a physiological range of central venous pressure (13.2 +/- 0.7 mmHg). Right heart function curve analysis confirmed marked augmentation of right heart performance, restoring almost normal pulmonary circulation. These functional benefits were sustained up to 4 hours in 4 animals until experiments were terminated. CONCLUSIONS Dynamic cardiomyoplasty in a modified Fontan procedure is a viable surgical option for univentricular heart, not a Fontan candidate.

A case report of aortic valve replacement following ruptured aneurysm of the sinus of valsalva with bicuspid valve

Only three cases of the combination of bicuspid aortic valve and ruptured aneurysm of the sinus of Valsalva, associated with previously repaired coarctation of aorta, have been reported. A twenty-year-old man with a sudden onset of CHF due to ruptured aneurysm of the sinus of Valsalva underwent intracardiac repair by direct closure of the sinus Valsalva in combination with patch closure of a subarterial VSD. Although, no AR was detected preoperatively, massive regurgitation occurred after the repair due to subsequent failure of aortic valve coaptation in the present of the bicuspid aortic valve, which was not diagnosed preoperatively. Aortic valve replacement with SJM 25 mm was successfully performed.