![]() ![]() In the Earing cohort, survival at 15 and 20 years was 73% and 69%. Khairy reported freedom from death or transplantation at 15, 20 and 25 years of 87%, 83% and 70% in patients who survived the perioperative period. Earing et al reviewed 225 double inlet left ventricle Fontan patients between 19 and described 13% perioperative mortality before 1988, and 3% thereafter. Khairy et al studied outcomes in 261 Fontan patients from 1973-1991, and reported 37% mortality before 1982, with an improvement to 16% between 19, and then 1.9% after 1990. Over recent decades there has been a significant improvement in perioperative mortality of Fontan patients. The pressure differential between the CVP and the LA, the “transpulmonary gradient,” is of paramount importance: this pressure differential is a major determinant of pulmonary blood flow and hence has a direct impact on cardiac output. Optimal Fontan physiology includes central venous pressure (CVP) of 10-15mmHg (although most Fontan patients have CVP >12), pulmonary artery pressure of 10-15mmHg, and left atrial (LA) pressure of 5-10 mmHg. The combined extracardiac and intracardiac Fontan may address some of these deficiencies, as the intracardiac component allows for the placement of a fenestration and the extracardiac component limits the number of suture lines. This technique has all the advantages of the Lateral Tunnel with less atrial manipulation and fewer suture lines, however, placement of the fenestration often requires using cardioplegia. The extracardiac conduit technique was developed in the 1990’s, and has come into common practice in the past 10 years. The Lateral Tunnel Fontan was introduced in the late 1980’s and involved baffling the systemic venous flow within the atrium in the hope of producing more streamlined blood flow and less atrial dilation. The disadvantage of this technique was the development of right atrial hypertension, leading to atrial stretch, dilation, arrhythmias and thrombus formation. Classic or Atriopulmonary Fontan, the predominant technique until the late 1980s, involved anastomosis of the right atrium directly to the pulmonary artery and most adult patients older than 25 yrs have this anatomy. There are several technical aspects of the Fontan procedure that have evolved over the past 40 years, perhaps the most worthy of mention is the evolution of the systemic venous to pulmonary connection. This can be useful in the post-operative period, when pulmonary vascular resistance may be high and cardiac output may be decreased after cardiopulmonary bypass. A fenestration can be placed to relieve elevated venous pressures and augment cardiac output by shunting blood directly to the atrium. Blood flows passively through the lungs, into a common atrium, and through the atrioventricular valve to the systemic ventricle (morphologically right or left). Fontan anatomy is characterized by flow of deoxygenated from the superior and inferior vena cave directly into the pulmonary vascular system. ![]() There are variations in timing and type of preceding operations however most patients have Fontan operation by 2-4 years. Anderson whilst looking at outcomes after Fontan palliation reported the underlying anatomic diagnosis in 546 Fontan patients, which were most commonly tricuspid atresia (22%), hypoplastic left heart syndrome (21%), and double inlet left ventricle (15%). There are many congenital cardiac anomalies that are palliated with multistage repair and ultimately the Fontan operation. The incidence of univentricular physiology is thought to be 0.5-5 per 10,000 live births. Revision of Fontan Anatomy and Physiology Long term outcomes and late complications are now more apparent as patients live longer however several recent publications highlighting Fontan “palliation” have emphasized there is still progress to be made in the long term management of these patients. Over the past 40 years, perioperative mortality has decreased substantially as surgical technique and perioperative care has improved. The Fontan procedure, first developed by Fontan in 1971, is a palliative procedure for patients with functional univentricular physiology. Joffe, MD and Michael Richards, BM, MRCP, FRCA An Update on the Fontan Operation: Morbidity, Mortality and Late Complicationsīy Lizabeth D. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |