Challenging Pulmonary Arterial Reconstruction in an Adult

The patient is a twenty-year-old female who was born with congenital bilateral branch pulmonary arteries hypoplasia and severe stenosis. She developed suprasystemic right ventricular pressure and underwent transcatheter balloon dilation and multiple stent placement that failed to demonstrate any growth in her branch pulmonary arteries or improvement in her right ventricular pressure. Echocardiography did not show any structural abnormalities. She also had chronic occlusion of her right upper lobar pulmonary artery for years with fixed defect in this area on her lung perfusion scan. The decision was made to proceed with surgical branch pulmonary arterial rehabilitation.

The procedure was performed via median sternotomy. Branch pulmonary arteries were dissected prior to initiation of cardiopulmonary bypass (CPB). Of note, the transesophageal echocardiogram (TEE) showed a patent foramen ovale and some dynamic right ventricular outflow tract obstruction (RVOT) with hypertrophied muscle bundles below the pulmonary valve. CPB was initiated via aortic and bicaval cannulation and the patient was cooled to 28 degrees Celsius. The main pulmonary artery was transected just above the valve and both branch pulmonary arteries were separated to facilitate the dissection. The left pulmonary artery had adequate distal branches and was incised along its lower lobar branch. 

Surgeons prepared a 26 mm cryopreserved pulmonary homograft and used its 14 mm left branch to reconstruct the left pulmonary artery by sewing its branch in an end to side fashion to the left main/lower lobar branch using running 5-0 polypropylene suture. The right pulmonary artery was then pulled from underneath the ascending aorta and the superior vena cava, where it was dissected further until the hilar branches were reached. The segment that included the stents was completely resected. A 14 mm descending aortic homograft was then prepared by clipping all the side branches and was connected to the right lower lobar branch of the right pulmonary artery in a similar fashion to the left side. The new right pulmonary artery was then placed back in its orthotopic position.

The surgical team then arrested the heart briefly to close the patent foramen ovale and evaluate the RVOT via the pulmonary valve. All hypertrophied muscle bundles were resected and the RVOT was adequately sized. The pulmonary homograft was then trimmed and connected to the native pulmonary artery above the valve in an end-to-end fashion with a running 5-0 polypropylene suture. The heart was deaired, the aortic cross clamp was removed, and rewarming back to normothermia began.

The right pulmonary artery reconstruction was then completed by connecting the right branch of the pulmonary homograft to the descending aortic homograft in an end-to-end fashion. This completed the reconstruction of the pulmonary arteries.

The patient was subsequently weaned off CPB without difficulty. A post bypass TEE showed good ventricular function with widely patent RVOT. Direct pressure measurement revealed less than 50 percent systolic right ventricular pressure to systemic pressure. The team was satisfied with these results. The remainder of the procedure was completed in the standard fashion and the patient was extubated in the operating room.

The postoperative course was uneventful, and the patient was discharged five days later. She continued to do well during her follow up and had a very satisfactory postoperative computed tomography scan showing adequately sized pulmonary arteries.

References

1. Said SM, Marey G. Bilateral branch pulmonary arterial reconstruction in the Alagille syndrome: The technique and its pitfalls. Multimed Man Cardiothorac Surg. 2022 Dec 2;2022
2. Margetson T, Mainwaring RD, Hanley FL. Overview of Cardiopulmonary Bypass Techniques and the Incidence of Postoperative Complications in Pediatric Patients Undergoing Complex Pulmonary Artery Reconstruction. J Extra Corpor Technol. 2022 Dec;54(4):330-337

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