Creating a Controlled Arterio-Venous Shunt by Reversing the Extracorporeal Membrane Oxygenation Blood Flow: A Strategy for Weaning Patients Off Veno-Arterial Extracorporeal Membrane Oxygenation.

OBJECTIVES: To assess whether reversing the veno-arterial extracorporeal membrane oxygenation blood flow (thereby creating a controlled arterio-venous shunt) can be used to wean children off extracorporeal membrane oxygenation. The standard practice for weaning patients off VA extracorporeal membrane oxygenation is to gradually reduce the blood flows delivered through the extracorporeal membrane oxygenation pump to a minimum level followed by either insertion of an "arterio-venous bridge" and clamping of the blood flow to the patient or direct decannulation. "Pump controlled retrograde flow trial off" is a technique where the revolutions in the centrifugal pump are reduced to the point where the patient will drive the blood retrograde through the extracorporeal membrane oxygenation circuit, effectively turning the circuit into a controlled arterio-venous shunt. The revolutions per minute control the amount of shunt flow. This eliminates any cardiorespiratory support the extracorporeal membrane oxygenation circuit may provide to the patient. DESIGN: Feasibility study. SETTING: Pediatric intensive care. PATIENTS: Extracorporeal membrane oxygenation-dependent pediatric patients, who were ready for weaning, and possible separation from extracorporeal membrane oxygenation entered the trial. INTERVENTION: Pump controlled retrograde flow trial off. MEASUREMENT AND MAIN RESULTS: During 2016, pump controlled retrograde flow trial off was used in 17 patients, for a total of 23 episodes. One episode was unsuccessful in a patient with a body weight of 2.2 kg, where cardiac output was insufficient to provide blood flow to both body and extracorporeal membrane oxygenation circuit, though from 2.8 kg body weight upward, the technique was tolerated. The duration of pump controlled retrograde flow trial off was 15 minutes to 2.5 hours. Five cases led to a continuation of the extracorporeal membrane oxygenation run, as they were not ready to be decannulated. Fifteen patients were decannulated after the pump controlled retrograde flow trial off. No patient needed to be recommenced on extracorporeal membrane oxygenation after decannulation. CONCLUSIONS: Pump controlled retrograde flow trial off is an easy to use and easily reversible technique to assess patient readiness for separation from extracorporeal membrane oxygenation. Given pump controlled retrograde flow trial off can easily be stopped and-in our experience-is not associated with complications, it lowers the threshold to attempt coming off extracorporeal membrane oxygenation and facilitates accurate assessment of whether a patient will need further ongoing extracorporeal membrane oxygenation support.

Anomalous origin of branch pulmonary artery from the aorta: Current challenges in the management.

Anomalous origin of a branch pulmonary artery from the aorta is a rare congenital anomaly that requires early surgery to prevent pulmonary vascular disease. The rate of reintervention after surgery remains high. Many aspects of the management could be improved such as assessment of operability in late presenters, selection of suitable surgical technique in each case, and prevention of anastomotic complications. We report the series of 10 patients who were operated for this anomaly. We aim to focus on the current challenges in the management of this condition.

Three's a Crowd-A Unique Combination of Coronary Artery Atresia, Fistula, and Stenosis: Multiple Congenital Coronary Artery Anomalies.

The incidence of congenital coronary artery anomalies in the general population is low. The combination of various significant coronary artery anomalies in a single patient is not very common. We describe a case of a 20-month-old child with a unique combination of congenital coronary anomalies (atresia, stenosis, fistula) which were accurately delineated by multimodal imaging and successfully managed surgically.

A comparison of pump-controlled retrograde trial off to arterio-venous bridging for weaning from venoarterial extracorporeal membrane oxygenation.

OBJECTIVES: The aim of the study is to compare a technique of pump-controlled retrograde trial off (PCRTO) to insertion of an arterio-venous (AV) bridge to conduct a trial from venoarterial extracorporeal membrane oxygenation (VA ECMO). METHODS: We studied all patients who were weaned from VA ECMO using either PCRTO or AV bridging from November 2014 to April 2018. Demographic data, indications for ECMO, duration of ECMO, duration of trial period off ECMO and survival were compared between the 2 groups. RESULTS: Seventy-nine patients were placed on VA ECMO from November 2014 to April 2018, of whom, 51 (65%) patients met the study inclusion criteria: 31 (61%) patients who had a trial period from VA ECMO using PCRTO and 20 (39%) patients who were weaned using an AV bridge. The indications for ECMO included cardiac (n = 16 and 11, respectively) and non-cardiac aetiologies (n = 15 and 9, respectively). There was 1 death in each group. The duration of the trial off VA ECMO was significantly shorter in the PCRTO group (median = 88.0 vs 196.6 min, P < 0.001). There were 2 conversions from PCRTO to AV bridging during the trial period off ECMO (2.9-kg neonate following a Norwood procedure and 2.2-kg patient following repair of ectopia cordis). CONCLUSIONS: PCRTO is a safe, simple and reproducible approach for enabling a trial period while preserving the circuit during weaning from VA ECMO. In our study, the duration of the trial period off VA ECMO was significantly shorter in the PCRTO group. PCRTO avoids manipulation of the ECMO circuit, provides a 'stress test' to evaluate cardiorespiratory reserve during the trial period off ECMO, is applicable for a wide variety of cardiac and non-cardiac indications and facilitates multiple attempts at weaning from ECMO.

Prolonged Postoperative Vasoplegia in Pediatric Patients on Chronic Angiotensin II Blocker Treatment.

Prolonged postoperative vasoplegia is known to occur following cardiac surgery in patients on chronic angiotensin II receptor blocker (ARB) treatment in adults. The perioperative management of these drugs in the pediatric population is not well described and here we would like to highlight this fact. While ARBs are increasingly used in children and adolescents with hypertension, there is lack of data to guide optimal pre-surgical management in the pediatric age group. We report two cases of prolonged vasoplegia following cardiopulmonary bypass occurring in adolescent patients on chronic ARB therapy and the importance of cessation of these drugs preoperatively.

Anesthetic implications of subxiphoid coronary artery bypass surgery.

BACKGROUND: Minimal invasive surgeries are carried out to benefit the patient with less pain, blood loss, mechanical ventilation and hospital stay; a smaller scar is not the aim. Minimal invasive cardiac surgeries are carried out via small sternotomy, small thoracotomy and via robotic arms. Subxiphoid route is a novel method and avoids sternotomy. AIM: This case series is an attempt to understand the anesthetic modifications required. Secondly, whether it is feasible to carry out subxiphoid coronary artery bypass surgery. METHODS: Elective patients scheduled to undergo subxiphoid coronary artery bypass surgery were chosen. The surgeries were conducted under general anesthesia with left lung isolation via either endobronchial tube or bronchial blocker. RESULTS: We conducted ten (seven males and 3 females) coronary artery bypass graft surgeries via subxiphoid technique. The mean EuroSCORE was 1.7 and the mean ejection fraction was 53.6. Eight patients underwent surgery via endobronchial tube, while, in the remaining two lung isolation was obtained using bronchial blocker. Mean blood loss intraoperatively was 300 ± 42 ml and postoperatively 2000 ± 95 ml. The pain score on the postoperative day '0' was 4.3 ± 0.6 and 2.3 ± 0.7 on the day of discharge. Length of stay in the hospital was 4.8 ± 0.9 days. There were no complications, blood transfusions, conversion to cardiopulmonary bypass. The modifications in the anesthetic and surgical techniques are, use of left lung isolation using either endobronchial tube or bronchial blocker, increased duration for conduit harvesting, grafting, requirement of transesophageal echocardiography monitoring in addition to hemodynamic monitoring. Other minor requirements are transcutaneous pacing and defibrillator pads, a wedge under the chest to 'lift' up the chest, sparing right femoral artery and vein (to serve as vascular access) for an unlikely event of conversion to cardiopulmonary bypass. Any anesthesiologist wishing to start this technique must be aware of these modifications. CONCLUSIONS: Subxiphoid route is safe to carry out coronary artery bypass graft surgery using the minimal invasive cardiac surgery. It is reproducible and has undeniable benefits. We plan to conduct such surgeries in awake patients under thoracic epidural anesthesia thus making it even less invasive and amenable for fast tracking.