Right Ventricle and Tricuspid Valve Function at Midterm After the Fontan Operation for Hypoplastic Left Heart Syndrome: Impact of Shunt Type

Abstract

This study aimed to evaluate clinical outcomes including hemodynamics, right ventricle (RV) function, and tricuspid valve (TV) function in patients with hypoplastic left heart syndrome (HLHS) at midterm after completion of staged palliation based on the source of pulmonary blood flow provided at stage 1. The records of all patients with HLHS who completed Fontan palliation between 2001 and 2007 were retrospectively reviewed. The outcome variables were RV dysfunction, TV, and neo-atrioventricular (neo-AV) regurgitation (from latest echocardiogram), cardiac index (CI), pulmonary vascular resistance (PVR), pulmonary artery pressure (PAp), and right ventricular end-diastolic pressure (RVEDp) (from latest catheterization). Clinical status was obtained from medical records and by contact with the referring cardiologist if necessary. Of 118 patients undergoing a Fontan for HLHS, 116 had a fenestrated lateral tunnel and 2 had an extracardiac conduit. At the time of stage 1 palliation, 36 patients had a right ventricle-to-pulmonary artery (RV-PA) conduit, and 82 patients had a modified Blalock-Taussig shunt (mBTS). All the patients except one who died of sepsis on extracorporeal membrane oxygenation (ECMO) survived the Fontan operation and were discharged home. At a mean follow-up post-Fontan period of 28.4 months (range, 0.16-95.3 months), three patients had died (2 on the transplantation list and 1 from pulmonary vein stenosis), and one patient had the Fontan circulation taken down. No patient had a heart transplantation. A follow-up echocardiogram was performed for 115 patients (after a mean of 15.6 months for RV-PA and 32.1 months for BTS), and 66 patients underwent a post-Fontan catheterization (after a mean of 15.8 months for RV-PA and 29.3 months for BTS). The hemodynamic results for RV-PA conduit versus BTS were a CI of 3.4 ± 0.8 versus 3.4 ± 1.2, a PVR of 1.8 ± 0.7 versus 1.7 ± 0.8, a PAp of 14.3 ± 3.1 versus 14.2 ± 4.5, and an RVEDp of 7.1 ± 3.3 versus 8.9 ± 5.3. No statistically significant differences were found between shunt types regarding survival or degree of RV dysfunction or in terms of neo-AV regurgitation, CI, PVR, PAp, RVEDp, or rhythm problems. Patients in the BTS group required more tricuspid valvuloplasties and had more tricuspid regurgitation at follow-up evaluation. The patients in the RV-PA group had more PA interventions. In conclusion, the contemporary results after Fontan palliation for HLHS were excellent. At the midterm follow-up evaluation, outcomes and hemodynamic data were similar between shunt types. However, the patients in the BTS group exhibited more tricuspid regurgitation, and the patients in the RV-PA group had increased pulmonary artery interventions.

Impact of Initial Shunt Type on Cardiac Size and Function in Children With Single Right Ventricle Anomalies Before the Fontan Procedure

“…In our cohort, it is similarly encouraging that indexed tricuspid annular size also decreased at the pre-Fontan study compared with the 14-month assessment in both shunt groups, nearly normalizing in size with z -scores approximating 2. The incidence of moderate or greater tricuspid regurgitation was stable (<20% at both intervals for both groups), a finding that differs from a recently published report that identified worse tricuspid valve (TV) function in the MBTS patients after Fontan (22). …”

Does Initial Shunt Type for the Norwood Procedure Affect Echocardiographic Measures of Cardiac Size and Function During Infancy?

“…19 The impact of shunt type after subsequent palliations remains unclear, however, as a recent report found no shunt-related difference in RV function after Fontan, but worse tricuspid valve function in the MBTS patients. 20 …”

The effect of right ventricular function on survival and morbidity following stage 2 palliation: An analysis of the single ventricle reconstruction trial public data set

“…14 These findings, however, have not been consistently demonstrated among other data sets that have found no effect on shunt type on degree of right ventricular dysfunction. 15 It was for this reason that we chose to assess later right ventricular function irrespective of shunt-type chosen at the time of stage 1 palliation.…”