Supplemental Bidirectional Glenn in Residual Outflow Obstruction after Tetralogy of Fallot Repair

William M. Novick ¹, Kamal Saleem ², Iftikhar Ahmed ², Mehboob Sultan ², Intisar Ul Haq ², Umair Younis ²

¹ University of Tennessee Health Science Center, Memphis, USA; ² Armed Forces Institute of Cardiology National Institute of Heart Diseases, Rawalpindi, Pakistan;

Date, time and location: 2018.05.25 13:30, Press Hall, 2F

Abstract

Background: Revision for significant post-bypass residual right ventricular outflow obstruction (RVOTO) during Tetralogy of Fallot repair often require a trans-annular patch with resultant pulmonary insufficiency. Supplementary Bidirectional Glenn shunt in this setting can pressure unload right ventricle to avoid revision.

Methods: Bidirectional Glenn (BDG) shunt was added during Tetralogy of Fallot repair in patients with significant post bypass residual RVOTO characterised by right to left ventricular pressure ratio (pRV/LV) greater than 0.8 in order to avoid trans-annular revision.  Between January 2011 and June 2017 552 patients underwent total repair of TOF, 40 patients received supplemental BDG and represent the cohort for analysis. Final follow up was performed September 2017.

Results: Mean age at repair, 5.1 +/- 3.1 years. Mean pRV/LV reduced from 0.91 ± 0.09 (range 0.82 – 1.2) to 0.68 ± 0.04 (range 0.6-0.75) (p>0.001) before and after bidirectional Glenn shunt respectively, avoiding revision in all cases. Mortality was 5% (2/40) in BDG cohort and 4.1% (21/512) in the non-BDG group, (p> 0.05), deaths in the BDG group were not procedure related. Pleural effusions requiring tube drainage ≥ 07 days was seen in 4/40 patients (10%). Discharge echocardiography revealed a mean trans-pulmonary gradient of 32.39 ± 5.92 mm Hg (range (25 - 45). Pulmonary insufficiency was none to mild in 35 (92.1%) and moderate in 03 (7.9%). Mean follow up was 28.2 ± 20.5 months (2.5 - 76). There were no interval interventions or death. All were in New York Heart Association functional class 1, with no increase in trans-pulmonary gradient or pulmonary incompetence compared to discharge (p= 0.6), (p = 0.3) respectively.

Conclusion: Additional bidirectional Glenn shunt significantly reduced residual right ventricular outflow obstruction during Tetralogy of Fallot repair avoiding revision with satisfactory early and mid-term results.