Thorac Cardiovasc Surg 2016; 64 - OP34
DOI: 10.1055/s-0036-1571862

The Effect of the Simultaneous Left Pulmonary Artery (LPA) Patch Enlargement during the Modified Norwood Procedure on the Lung Perfusion: First MRI Results of HLHS Patients

Ravesh M. Salehi 1, T. Attmann 2, J. Scheewe 2, A. Al Bulushi 1, D. D. Gabbert 1, P. Wegner 1, E. Pardun 1, I. Voges 1, C. Hart 1, I. Kristo 1, H. H. Kramer 1, C. Rickers 1
  • 1University Hospital Schleswig-Holstein, UKSH, Department for Congenital Heart Disease and Pediatric Cardiology, Kiel, Germany
  • 2University Hospital Schleswig-Holstein UKSH, Department for Cardiovascular Surgery, Kiel, Germany

Objectives: Optimal pulmonary perfusion is crucial for a well-functioning Fontan circulation. For the palliation of patients with hypoplastic left heart syndrome (HLHS), patch enlargement of the left pulmonary artery (LPA) can be performed either during the modified Norwood or hemi-Fontan procedure. The aim of this study is to compare the outcome of both surgical techniques regarding the lung Perfusion utilizing novel MRI techniques.

Methods: Between September 2010 and May 2013, the LPA of 23 HLHS patients were enlarged during the modified Norwood procedure (group A, age at MRI 3.1 ± 0.5 years, 14.7 ± 2.0 kg). In this work, the MRI Results of these patients were compared with 29 HLHS patients (group B, age at MRI 3.1 ± 0.8 years, 13.8 ± 1.9 kg), who previously received an enlargement of the LPA during the hemi-Fontan procedure. All patients received a comprehensive MRI study, including anatomical (Nakata-Index) and functional measurements. The mean transit time of the contrast agent (MTT) was calculated using the measured signal-time-courses in the left and right lung parenchyma to assess pulmonary Perfusion. Furthermore, three-dimensional phase contrast MRI (4D-Flow) was used to measure aorto-pulmonary collateral flow.

Results: All patients survived modified Norwood and hemi-Fontan surgery without major complications. The patients in group A have a significant higher Nakata-index as compared with group B (162.4 ± 33.9 vs. 95.7 ± 30.1 (mm/m)2, p< 0.001). MTT was by 10% lower in group A (2.86 ± 0.96 vs. 3.09 ± 1.08 ms), indicating improved lung perfusion. The percentage of patients with significant collateral flow in group A and B were 30 and 50%, respectively (p< 0.05).

Conclusion: These first follow-up MRI data show that HLHS patients after LPA patch enlargement during the modified Norwood procedure have significantly higher LPA diameters and show improved lung perfusion. This novel surgical technique may also prevent the development of aorto-pulmonary collaterals.