Learning about Pulmonary Root Translocation
August 24, 2020 | Contributed by R. Srivatsan
Being a foundation for critically ill children, supporting surgeries associated with Congenital Heart Defects, we have only aided one case of Pulmonary Root Translocation till date. This goes on to show its rarity.
What is Pulmonary Root Translocation?
Pulmonary Root Translocation is a surgical treatment modality for patients with D-Transposition of Great Arteries (D-TGA) with Ventricular Septal Defect (VSD) and Pulmonary Stenosis (PS). This technique maintains the growth potential of native pulmonary valve and avoids the need for Right Ventricle to Pulmonary Artery conduit (RV to PA). It also avoids the need for coronary handling as required in Nikaidoh procedure.
Conceptually, translocation of the Pulmonary Root is opposite of the Nikaidoh procedure. The pulmonary root is harvested and translocated anteriorly as opposed to posterior translocation of the aortic root in the Nikaidoh procedure. Pulmonary root translocation for TGA/VSD/ PS has been introduced and popularized by Dr Da Silva from Brazil.
Treatment for Pulmonary Root Translocation
The Pulmonary Artery is dissected and mobilized as much as possible before the initiation of Cross Pulmonary Bypass (CPB). CPB is initiated and then the heart is arrested. A right ventriculotomy is performed, and the Pulmonary Root is harvested using careful visualization from outside and inside.
Care should be taken to avoid injury to the pulmonary, aortic, or mitral valve. Entering the interventricular septum is also avoided. The opening in the Left Ventricle is checked for injury to the mitral valve and is closed using a glutaraldehyde-treated autologous pericardial patch. The VSD is inspected as it often needs enlargement which is achieved by resection of the conal septum. Then, a Dacron baffle is constructed to route the Left Ventricle to the Aorta. Enlargement of the Pulmonary Valve is performed if necessary using a Monocusp valve. The intact Pulmonary Artery is brought anteriorly to the left of the Aorta without a Lecompte maneuver and is sutured to the right ventriculotomy complemented with an autologous pericardial patch.
Pulmonary Root Translocation keeps the aorta and coronary arteries untouched in contrast to the Nikaidoh procedure. Dr Da Silva has reported adequate growth of the implanted pulmonary root. However, he does not recommend this procedure if the VSD is small or is remotely located. It is mandatory for the VSD to be routable to the Aorta with or without enlarging the same.
Pulmonary root translocation.
(a) The pulmonary root is dissected out, and its origin is closed using a glutaraldehyde-treated autologous pericardial patch.
(b) After partial resection of the conal septum, a Dacron patch is used to create a tunnel from the left ventricle to the aorta.
(c) The pulmonary root is sutured to the right ventriculotomy with a running 6-0 polydioxanone suture, and the right ventricular outflow tract is completed
using an in situ pericardial patch combined with a glutaraldehyde-treated autologous pericardial patch.
(d) The final appearance after the procedure.
Pulmonary root translocation was first described as a technique for anatomic correction of Double Outlet Left Ventricle (DOLV). In 1992 Chiavarelli et al. reported the surgical correction of DOLV in a 4-month-old female infant using Pulmonary Root Translocation. The authors presented Pulmonary Root Translocation as an alternative to intraventricular tunnel repair.
The reported ten-year survival period for Pulmonary Root Translocation is 82.9%.
The Pulmonary Root Translocation method to treat children diagnosed with TGA, VSD and PS is extremely rare. Considering this rarity, our Foundation for critically ill children has supported one such case, that of Pratik. Pratik was operated upon by Dr. Anil Kumar Dharmapuram, pediatric cardiac surgeon at KIMS Hospital, Hyderabad.
At 2 years of age, Pratik is the second youngest child in India to undergo Pulmonary Root Translocation.