Mechanical Circulatory Support Following Norwood Palliation

Pediatric mechanical circulatory support - a review

The history of mechanical circulatory support began in 1953, as the first heart-lung machine enabled surgeons to perform complex open heart surgery. Heart failure is more prevalent in adults than pediatric patients which has led to the development of devices for adults with end-stage heart failure at a faster pace. Pediatric mechanical circulatory support has been derived from adult durable devices and subsequently applied in the adolescent population. The application of adult devices in children is inherently problematic due to size mismatch, especially in smaller patients. There has been an increasing interest in developing durable pumps that are appropriate for children for several reasons, with the primary factor being the number of children with end-stage heart failure far exceeding the number of potential donors. Mechanical circulatory support (MCS) for children can be divided into short-term temporary support and long-term durable support. The goal of this review is to discuss the devices available for the pediatric population and review the options for support in complex patients including single-ventricle anatomy, biventricular support, and total artificial heart options. We will also briefly discuss the Pumps for Kids, Infants, and Neonates (PumpKIN) Trial and MCS registries, including the Advanced Cardiac Therapies Improving Outcomes Network (ACTION).

Evolution of Ventricular Assist Device Support Strategy in Children with Univentricular Physiology

BACKGROUND

Since 2012, we have supported 18 children with single ventricle (SV) physiology on ventricular assist devices (VAD) as a bridge to decision, transplant, or recovery. We provide a detailed report of our cumulative surgical experience and lessons learned from these patients.

METHODS

We reviewed all SV-VADs between March 2012 and April 2020. Implanted SV-VADs intended for short-term support were excluded. Demographic and clinical data included palliation stage at the time of VAD implantation, cannulation configuration, device type, duration of support, circuit and device interventions, postoperative support, anticoagulation strategy, complications, mortality, and one-year survival post-discharge.

RESULTS

Five SV-newborns without prior surgical palliation, 8 infants post-Norwood/hybrid procedure, 4 post-Glenn, and 1 post-Fontan were initially supported with either continuous flow13/18(72%) or pulsatile flow 5/18(28%) devices. 3/18(17%) transitioned to another device during support. Before VAD conversion, 9/18(50%) were supported by extracorporeal membrane oxygenation. Outcomes include; 7/18(39%) transplanted, 2/18(11%) recovered, and 9/18(50%) died prior to discharge. Of these deaths, 2 occurred following transplant, 2 following explant and 5 had redirection of care while on support secondary to previously undiagnosed pulmonary veno-occlusive disease (n=2) or severe neurologic events (n=3). Overall, 6/18(33%) experienced neurologic injury. At last follow-up 9/18(50%) children were alive [1.2(0.8-4.3) years post-explant/transplant].

CONCLUSIONS

Our experience shows that SV children, including newborns, can be successfully bridged to desired end-points with proper patient selection and using specific cannulation strategies. Continuing utilization of this strategy is warranted for future children requiring VAD support.

A Review of Physiologic Considerations and Challenges in Pediatric Patients With Failing Single- Ventricle Physiology Undergoing Ventricular Assist Device Placement

Advances in surgical techniques and outpatient cardiac care have led to a growing population of pediatric patients surviving well into adulthood with previous single-ventricle palliation. Continued improvement in survival has resulted in subsequent increases in the number of patients with single-ventricle physiology listed for heart transplantations. Some of these patients require mechanical circulatory support as a bridge to transplantation, although establishing successful mechanical circulatory support in these complex patients remains challenging. Only limited published data exist describing the perioperative anesthetic management and key considerations dedicated to patients with failing single-ventricle physiology presenting for ventricular assist devices. This clinical review aims to provide a focused evaluation of the vital perioperative considerations encountered in this novel population.

A milestone in congenital cardiac surgery: Four decades of the Norwood procedure

Hypoplastic left heart syndrome (HLHS) was first described by Lev in 1952, but it was not until 1958 that it received a name from Noonan and Nadas. For the next several decades, the defect was considered untreatable. In 1979, William Norwood and his colleagues from Boston initiated a program to evaluate staged surgical management for infants with HLHS. The Norwood operation has became a milestone in the effective palliation for neonates born with HLHS. Today, the Norwood procedure is the first step of a three-stage heart surgery aimed at creating a new circulatory pathway (i.e., the Fontan pathway).