Fontan Procedure at 2,240 m Above Sea Level

Abstract

The modified Fontan procedure represents the final stage of reconstructive surgery for most patients with functionally univentricular hearts. Although outcomes following Fontan procedures performed at sea level are widely reported, less has been documented and reported concerning outcomes in regions at high altitude. To clarify the main features involved, we present our institutional experience with Fontan operations performed in Mexico city (2,240 m above the sea level), with an emphasis on historical evolution of treatment. A retrospective and observational study was undertaken, which included 98 patients over a period of 18 years, and clinical outcomes in terms of morbidity and mortality were analyzed. A change in operative technique from intra-cardiac nonfenestrated Fontan procedure to extra-cardiac fenestrated technique occurred in 2001. Early mortality rates before and after this change in surgical approach were 26% and 4.7%, respectively. The most common morbidity was the occurrence of pleural effusions (98% of patients), which also appears to be a risk factor for operative mortality. Much remains unknown about the pathophysiology of the Fontan circulation at high altitude, and we need to develop morphological study protocols that include pulmonary biopsy to increase our knowledge and inform our therapeutic actions.