Farhouch Berdjis, MD; Michael R. Recto, MD; Sharib Gaffar, MD
The management of right-ventricle-to-main-pulmonary artery conduit in patients who have previously undergone transannular right-ventricular outflow patch for Tetralogy of Fallot (TOF) continues to evolve. In this case series, we describe our experience with transcatheter management of five patients who had previously undergone placement of an Edwards pericardial tissue valve in the right-ventricle-to-main pulmonary artery position, and developed both severe pulmonary valve insufficiency and mild-to-moderate pulmonary valve stenosis with right ventricular enlargement. In order to optimally place the largest available Melody valve (22 mm), these patients underwent pulmonary valve ring fracture with high pressure Atlas balloons. The Atlas balloons were upsized by 1 mm from the surgical valve diameter and inflated to 22 atm. Valve ring fracture was achieved in all five cases. Post valve ring fracture, the diameter increased between 1.1 to 1.8 mm (mean 1.3 mm) and pressure gradient across the fractured valve ring decreased between 7 to 18 mmHg. This case series describes successful fracture of surgically-placed pulmonary valve ring with high pressure Atlas balloons and subsequent placement of the largest available Melody valve.
The surgical repair of Tetralogy of Fallot (TOF) has not significantly changed since it was first proposed by Lillehei in 1954. The operation consists primarily of Ventricular Septal Defect closure and placement of a transannular right-ventricular outflow tract patch. Almost all patients who have undergone complete TOF repair will, over time, develop progressive right ventricular enlargement secondary to pulmonary valve insufficiency. For many years, standard management of pulmonary valve insufficiency following complete TOF repair with transannular right-ventricular outflow tract (RVOT) placement involved placement of surgical valved conduits. These valved conduits would then calcify and either develop stenosis or insufficiency. Transcatheter (Melody) valve placement is accepted therapy for patients who have previously undergone placement of prosthetic right ventricle to main pulmonary artery conduits who, over time, have developed significant conduit stenosis or insufficiency. In this case series, we document our experience fracturing surgically-placed Edwards pericardial tissue valves (Edwards Lifesciences Corporation; Irvine, California) with high pressure Atlas Balloons (Bard Peripheral Vascular; Tempe, Arizona) in four patients with TOF and one patient with critical pulmonary valve stenosis who had initially required transannular RVOT patch as an infant and subsequent placement of an Edwards pericardial tissue valve. The pulmonary valve ring was successfully fractured in all five cases, allowing for successful implantation of the larger diameter (22 mm Melody) valve that would have been possible without pulmonary valve ring fracture.
FIGURE 1 Patient with an initial 21 mm Edwards surgical valve. Clockwise from A to D: A) Valve diameter was 19.9 mm and had evident severe pulmonic insufficiency. B) 22 mm Atlas balloon immediately prior to (white arrow) and C) after successful valve splitting (white arrow). D) Transcatheter 22 mm Melody valve successfully implanted, with resolution of pulmonic insufficiency. Post-splitting valve diameter is now 21.1 mm.
Five patients, four males and one female, were followed on a regular basis from the newborn period until their adolescent years. Four of the five patients had TOF; the remaining patient had critical pulmonary valve stenosis. The four patients with TOF underwent complete repair with transannular RVOT patch placement between three to eight months of age (median five months old). The one patient with critical pulmonary valve stenosis underwent transannular RVOT patch at 2.5 mos after progressive cyanosis following balloon valvuloplasty on the first day of life. After complete repair, these patients developed severe pulmonary valve insufficiency and right ventricular enlargement necessitating placement of an Edwards pericardial tissue pulmonic valve between five and nine years of age (median eight years old).
All patients had regular yearly echocardiograms performed during cardiology follow-up appointments. Progressive echocardiograms demonstrated severe pulmonary valve insufficiency with right ventricular enlargement. Two of the patients also developed moderate pulmonary valve stenosis. The decision was then made to proceed with transcatheter Melody valve placement to relieve the pulmonic insufficiency and halt progression of right ventricular enlargement.
The patients ranged from 9 to 15 years old (median 11 years) at time of catheterization, with weight ranging from 31 to 77 kg (median 48 kg). The time between placement of surgical pericardial tissue valve and need for transcatheter Melody valve placement ranged from three to six years (median six years).
To read the full article, please go to the July 2019 Issue of CCT.