The patient consented to the publication of this case report. The patient was a 39-yr-old man, who presented for elective laparoscopic cholecystectomy at The Ottawa Hospital (Ottawa, ON, Canada). When he initially presented elsewhere with acute cholecystitis and sepsis, he had developed episodes of nonsustained ventricular tachycardia. These resolved with treatment of his sepsis and the insertion of a percutaneous drain.

The patient had a history of a univentricular heart with a morphologic right systemic ventricle, mitral atresia, and pulmonic atresia. Flow of systemic venous return to the pulmonary circulation was via an extracardiac bicaval conduit. Also present was a fenestration connecting the extracardiac conduit to the common atrium. Should pulmonary pressure increase, this fenestration allows venous blood to flow into the lower pressure common atrium, thereby maintaining systemic circulation (albeit with venous blood). Pulmonary veins, supplying oxygenated blood from his lungs, are connected to a common atrium. The common atrium is connected to a single morphologically right ventricle responsible for his systemic circulation.

During his first admission with acute cholecystitis, the patient was managed by a multidisciplinary team involving cardiologists, infectious disease specialists, gastroenterologists, and general surgeons. In view of his complex medical history and elevated perioperative risk, the decision was made to treat him conservatively. The patient responded well to antibiotics, marked by resolving fever and abdominal pain. Laparoscopic cholecystectomy was arranged electively for a later date at our centre, a tertiary care facility equipped with appropriate resources including intensive care access and an anesthesiologist certified in advanced TEE.

Despite his cardiac complexity and multiple cardiac surgeries resulting in complete heart block and pacer dependency, the patient had excellent functional capacity including working fulltime as a property manager. On preoperative assessment, he was noted to be mildly cyanotic with digital clubbing. His peripheral oxygen saturation on room air was 82% with a blood pressure of 126/89 mm Hg. The patient stated that these findings were normal for him. Preoperative transthoracic echocardiography showed a moderately reduced systolic function, mild to moderate atrioventricular valve regurgitation, and a patent conduit. His hemoglobin was 170 g·dL−1; the remainder of his laboratory results were unremarkable.

The patient discontinued his chronic warfarin medication five days prior to surgery, with anticoagulation being continued perioperatively with subcutaneous dalteparin. On the day of surgery, his pacemaker was programmed to an asynchronous ventricular pacing mode with a rate of 80 beats per minute. The surgeon’s goal was to maintain a low intra-abdominal pressure (10–12 mm Hg).6 Procedural termination criteria, communicated among the team members, included but were not limited to deteriorating hemodynamic parameters and unstable arrhythmias.

We inserted a preinduction arterial catheter and placed a five-lead electrocardiogram, peripheral nerve stimulator, and monitors according to the standard Canadian Anesthesiologists’ Society guidelines.7 External defibrillation/pacing pads were also placed. General anesthesia was induced with fentanyl (200 µg iv), lidocaine (100 mg iv), propofol (slowly titrated to 300 mg iv), and rocuronium (50 mg iv). The dose of propofol was surprisingly large; however, this was required to achieve loss of voice response and eyelash reflex. No significant hypotension occurred despite the required propofol dose. Sevoflurane and an intravenous remifentanil infusion were used for maintenance. A mean arterial pressure of ≥ 65 mm Hg was maintained with a low-dose intravenous norepinephrine infusion.8 Inhaled milrinone (5 mg) was available via nebulization via the tracheal tube in case of an increase in PVR. This was diagnosed indirectly by an increase in venous return through the conduit and into the systemic circulation. The setup of inhaled milrinone is described in a separate section. We used positive pressure ventilation with a maximum airway pressure of 23 cm H2O, and we maintained pneumoperitoneum at 10 mm Hg. An initial arterial blood gas prior to abdominal insufflation showed respiratory acidosis (pH, 7.27; pCO2, 56 mm Hg; HCO3, 26 mEq·L−1). Although some permissive hypercapnia was acceptable, minute ventilation was adjusted such that pCO2 was kept in the mid-40s. One-thousand millilitres of intravenous crystalloid was given and minimal blood loss was observed.

Intraoperative TEE showed a univentricular heart with mild global dysfunction (ejection fraction, 41–51%). The extracardiac conduit was visualized connecting the inferior vena cava to the main pulmonary artery with fenestration to the common atrium. There was intermittent flow of desaturated blood through the conduit into the common atrium and, from there, to the systemic circulation. Conduit flow was seen to increase approximately 10 min after abdominal insufflation. Conduit flow decreased after 5 mg of milrinone was nebulized into the respiratory circuit. Administering milrinone via the respiratory circuit decreases the PVR while limiting systemic hypotension, allowing more venous return through the lungs and reducing flow through the conduit. A wall-hugging jet was identified at the atrioventricular valve, indicating moderate to severe atrioventricular valve regurgitation. Spontaneous echo contrast was visualized in the hepatic veins, consistent with slow systemic venous return. Figures 1 and 2 show the anatomy of the patient’s Fontan circulation. A clip showing flow through the fenestration can be found in the Electronic Supplementary Material eVideo.

Transesophageal echocardiography (TEE) in the midesophageal four-chamber view. (A) Two-dimensional TEE shows a common atrium and a single ventricle with an atrioventricular valve. (B) Colour Doppler TEE shows a wall-hugging jet indicating moderate to severe atrioventricular valve regurgitation.

A shunt flow is seen across an (a) extracardiac conduit into a (b) common atrium through a (c) fenestration

The surgery proceeded uneventfully. Following neuromuscular reversal with sugammadex, the patient was easily extubated and was monitored in the postanesthesia care unit overnight. There were no postoperative complications, and the patient was discharged the following morning.