The Fontan circulation: An alternative physiology

Anesthesia Management for Epicardial Pacemaker Electrode Implantation in a Patient With a History of Fontan Procedure: A Case Report

One-lung ventilation is commonly used in lateral open chest surgery; however, it can increase pulmonary vascular resistance, which negatively affects Fontan circulation. Nevertheless, one-lung ventilation has a positive indication in post-Fontan patients. It allows surgery with lateral minimally invasive thoracotomy, which does not require a median sternotomy. Post-Fontan patients often have strong adhesions around the sternum and mediastinum due to multiple surgeries. Even worse, the large vessels sometimes adhere to the sternum, and a median sternotomy risks major hemorrhage. Since such risks can be avoided, one-lung ventilation is beneficial. Herein, we report our experience of one-lung ventilation anesthesia management for a post-Fontan patient who underwent pacemaker electrode implantation by right-sided minimally invasive thoracotomy. The Fontan circulation has a low tolerance for hypoxemia, so immediate treatment is necessary if hypoxemia develops during one-lung ventilation. Therefore, we connected the dependent lung side of the double-lumen tube to the anesthesia circuit and the nondependent lung side to the Jackson-Rees circuit, thereby completely separating the dependent and nondependent lungs. The Jackson-Rees circuit is highly versatile because the valve can be set to open and close freely, allowing the valve to be opened completely to administer oxygen, semi-closed to apply continuous positive airway pressure to the nondependent lungs, or ventilate the nondependent lungs at any desired time. We used this circuit to address hypoxemia during one-lung ventilation. Upon initiating one-lung ventilation, central venous pressure (CVP) increased from 8 to 19 mmHg, and SpO2 dropped from 99% to 83%. However, administering oxygen to the non-ventilated lung improved SpO2 to 98% and decreased CVP to 14 mmHg. Throughout the procedure, intermittent ventilation of the nondependent lung was performed cautiously to avoid disrupting the surgical field, allowing the operation to be completed safely. Intermittent ventilation of the nondependent lung using the Jackson-Rees circuit, without interfering with the operative field, was effective in maintaining oxygenation during one-lung ventilation in a patient with a history of Fontan procedure.

Long-term survival of patients with unoperated single ventricle heart defect: Four case reports and literature review

A single ventricle (SV) heart defect is a rare complex congenital cardiac malformation, accounting for approximately 1%-2% of congenital heart diseases. Surgical intervention is the mainstay treatment for SV patients, although patients who do not receive surgical intervention may also survive. We followed up four adult patients who had SV since birth without surgical intervention and they had a good prognosis. The common characteristics of four long-term SV survivors were investigated by reviewing their medical records and the literature, and the current treatment methods for SV patients were also reviewed. The clinical presentation and long-term prognosis of SV patients without surgical intervention depend on the presence or absence of pulmonary blood flow obstruction, pulmonary vascular resistance, ventricular shape and function, aortic blood flow obstruction, and the atrioventricular valve shape and function. While the Fontan operation has become a common and effective method for SV treatment, long-term outcomes are fraught with morbidity and mortality. In our opinion, such patients with balanced hemodynamic condition could be followed and treated conservatively. Major cardiac surgery which leads to gross hemodynamic adjustments should be avoided. However, additional prospective study will be necessary to verify this assertion. This report aims to improve the prognosis as well as quality of life of SV patients.