A shunt decision-making protocol in the surgical palliation of hypoplastic left heart syndrome from 2004 to 2016.

OBJECTIVES: The aim of this study was to study the impact of a decision-making protocol for shunt type in the Norwood procedure for hypoplastic left heart syndrome. Our cohort extends from 2004 to 2016. In era 1 (pre-2008), there was no policy for the choice of Norwood shunt. In era 2 (post-2008), a standard protocol was implemented. The right ventricle (RV)-to-pulmonary artery conduit was utilized for low-birth weight patients (<2.5 kg). The right modified Blalock-Taussig Shunt (RBTS) was constructed for normal birth weight patients. METHODS: The records of 133 consecutive operative patients with hypoplastic left heart syndrome anatomy between 2004 and 2016 were retrospectively reviewed. Survival risk factors were analysed using the Cox proportional hazards risk model. RESULTS: The Norwood procedure was performed at a mean age of 2.9 ± 1.9 days. Bidirectional cavopulmonary shunt was performed at a median age of 99 days (interquartile range 91-107). In era 1, 38.6% (22/57) of patients received the RBTS and 61.4% (35/57) of patients received the RV-to-pulmonary artery conduit. In era 2, 86.8% (66/76) of patients received the RBTS and 13.2% (10/76) of patients received the RV-to-pulmonary artery conduit. The actuarial survival to Fontan was 72.2% (96/133). Era 1 patients were more likely to die within the 1st year (hazard ratio = 2.310, P = 0.025). CONCLUSIONS: The shunt protocol may improve outcomes in high-risk patients, and we have demonstrated the reliability of the RBTS in low-risk patients. The short- and mid-term outcomes of our Norwood population justify the continued efforts to improve surgical and perioperative management.

Single ventricle: repair of atrioventricular valve using the bridging technique.

Atrioventricular valve regurgitation is one of the predictors of adverse outcomes after the Fontan procedure. We describe our surgical technique of GoreTex (W. L. Gore & Associates, Inc., Flagstaff, AZ, USA) bridge to repair a common atrioventricular valve in single-ventricular circulation. The repair includes a GoreTex strip that is secured to the mid-line of both superior and inferior bridging leaflets and annulus to obtain a better coaptation of the leaflets and prevent further dilatation of the annulus. We have applied this technique for 7 consecutive patients with excellent outcomes.

Differences in extra-cellular matrix and myocyte homeostasis between the neonatal right ventricle in hypoplastic left heart syndrome and truncus arteriosus.

OBJECTIVE: The right ventricle in hypoplastic left heart syndrome (HLHS) works at systemic pressure and large volume loading before and after first stage palliation. There is a paucity of information regarding the intrinsic characteristics of the right ventricle in HLHS. We studied extra-cellular matrix composition, myocyte homeostasis and gene expression in right ventricular biopsies obtained from patients with HLHS undergoing neonatal first stage palliation and from patients undergoing neonatal truncus arteriosus repair. METHODS: Tissue was evaluated using histological and real-time PCR techniques using the truncus group as a comparative group. Mean difference in outcomes between the HLHS and truncus groups was estimated using linear regression models in unadjusted and age-adjusted analyses. RESULTS: Markers of cell proliferation, apoptosis and fibronectin were significantly higher in the right ventricular myocardium of patients with hypoplastic left heart syndrome compared to truncus arteriosus. Type I collagen content and NKX2.5 expression were significantly lower in HLHS than the truncus group. CONCLUSION: The neonatal right ventricle in HLHS demonstrates a number of intrinsic differences compared to the right ventricle in truncus arteriosus including relative immaturity of the extra-cellular matrix, inappropriately low transcription factor expression and increased myocyte apoptosis.

Aortic translocation, Senning procedure and right ventricular outflow tract augmentation for congenitally corrected transposition, ventricular septal defect and pulmonary stenosis.

The management of congenitally corrected transposition of the great arteries and associated lesions is frequently challenging. Significant pulmonary stenosis is a contraindication to the conventional double-switch. Instead repair may be accomplished by the Rastelli-Senning procedure, using an extracardiac conduit to achieve continuity between the morphological left ventricle and the pulmonary arteries. This however can be accompanied by conduit and intra-ventricular baffle-related problems that can necessitate surgical re-intervention and lead to late mortality. We describe the use of aortic translocation, Senning procedure and reconstruction of the right ventricular outflow tract using autologous tissue and valved homograft to facilitate anatomical correction in congenitally corrected transposition. The advantages of this technique in this group of patients and the implications for conduction tissue are discussed.