CARDIAC-CATHETERIZATION AND TEST OCCLUSION OF THE INTERATRIAL COMMUNICATION AFTER THE FENESTRATED FONTAN OPERATION

Objectives. Our objective arts to determine whether catheterization da ta obtained after a fenestrated Fontan operation influenced patient ma nagement or predicted functional status. Background. Cardiac catheteri zation after a fenestrated Fontan operation is undertaken to identify residual lesions and to observe the patient's response to test occlusi on of the baffle fenestration. Methods. Sixty patients undergoing both a fenestrated Fontan operation before July 1991 and a postoperative c atheterization before March 1992 were included in the study. Catheteri zation data were collected according to a test occlusion protocol; the se data were reviewed, and the patient's clinical status at follow-up was ascertained. Results. Test occlusion resulted in a significant inc rease in systemic venous pressure, arterial oxygen saturation and arte riovenous difference in oxygen content (p < 0.0001). After test occlus ion, systemic venous pressure was 4O% higher and systemic venous satur ation 23% lower among patients with unfavorable versus a favorable res ponse to test occlusion, although differences between the two groups w ere subtle or inapparent in the baseline state. Branch pulmonary arter y stenosis (identified and balloon dilated in 6 patients) and grade 2 or 3 aortopulmonary collateral vessels (identified and coil embolized in 20) were associated with elevation in systemic venous pressure (p < 0.01). After an average of 2 years of follow up there were no deaths, and 50 (83%) of 60 patients were in New York Heart Association functi onal class I. The only postoperative characteristic significantly asso ciated with being in functional class I at follow-up was a systemic ve nous pressure <17 mm Hg. Conclusions. Cardiac catheterization with tes t occlusion of the interatrial communication provides useful informati on after a fenestrated Fontan operation. Conditions associated with el evated systemic venous pressure should be sought and treated, and the response of systemic venous pressure to test occlusion should be consi dered when deciding whether to close an interatrial communication.