Higher Pulmonary Vein Index From Preoperative Computed Angiography & Good Surgical Resection Ensures A Smooth Post-Operative Recovery Sans Low Cardiac Output Syndrome in a TOF Child-Special Emphasis On Indices Of Evaluation, Monocusp Preparation.
Author Information - 1) Vishal V. Bhende Primary Author, Consultant,Pediatric Cardiac Surgery, Bhanubhai and Madhuben Patel Cardiac Centre,Shree Krishna Hospital,Gokal Nagar,Karamsad,Anand,Gujarat - 388 325,India. E mail:drvishalbhende@gmail.com Mobile : + 91 98453 83405 2) Tanishq S. Sharma, Corresponding Author, Pediatric Cardiac Surgery, Bhanubhai and Madhuben Patel Cardiac Centre, Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:sharma.tanishqtask@gmail.com Mobile : + 91 79902 43174 3) Deepakkumar V. Mehta Professor & Head,Department of Radiodiagnosis & Imaging, Pramukhswami Medical College & Shree Krishna Hospital, Bhaikaka University,Karamsad,Anand,Gujarat - 388 325,India. E mail:deepakvm@charutarhealth.org Mobile : + 91 98791 67676
4) Krishnan Ganapathy Subramaniam
Consultant,Cardiac Surgeon,Mgm Healthcare, Aminjikarai, Chennai
E mail : ganapathysubramaniamk@gmail.com
Mobile : 09600050895 5) Amit Kumar Consultant,Pediatric Cardiac Intensivist, Bhanubhai and Madhuben Patel Cardiac Centre,Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:amitpaed2006@yahoo.com Mobile : + 91 82380 10476
6) Bhadra Y. Trivedi Consultant,Pediatric Interventional Cardiologist,Bhanubhai and Madhuben Patel Cardiac Centre,Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:Bhadra81@gmail.com Mobile : + 91 99877 18447 7) Jigar P. Thacker
Assistant Professor,Department Of Pediatrics, Pramukhswami Medical College, Bhaikaka University, Karamsad
E mail: thackerjigar@yahoo.co.in
Mobile : 9426621883
8) Viral B. Patel Professor,Department of Radiodiagnosis & Imaging, Pramukhswami Medical College & Shree Krishna Hospital, Bhaikaka University, Karamsad,Anand,Gujarat - 388 325,India. E mail:viralvp@charutarhealth.org Mobile : + 91 98250 60977 9)Gurpreet Panesar Consultant,Cardiac Anaesthesiology, Bhanubhai and Madhuben Patel Cardiac Centre, Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:Panesar_preeti@yahoo.co.in Mobile : + 91 98253 58661 10)Kunal Soni Consultant,Cardiac Anaesthesiology, Bhanubhai and Madhuben Patel Cardiac Centre, Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:drkunalsoni@gmail.com Mobile : + 91 90999 21950 11)Kartik B. Dhami Consultant,Cardiac Anaesthesiology, Bhanubhai and Madhuben Patel Cardiac Centre, Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:kartikbdhami@yahoo.com Mobile : + 91 91794 73521 12)Hardil P. Majmudar Cardiac Surgery, Bhanubhai and Madhuben Patel Cardiac Centre,Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail: hardil.majmudar@gmail.com Mobile : + 91 92659 03713
13)Nirja Patel Fellow,Cardiac Anaesthesiology,Bhanubhai and Madhuben Patel Cardiac Centre, Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:nirjapatel27@gmail.com Mobile : + 91 75758 01142
14) Sohilkhan Pathan Clinical Research Co-ordinator, Bhanubhai and Madhuben Patel Cardiac Centre, Shree Krishna Hospital,Karamsad,Anand,Gujarat - 388 325,India. E mail:sohilrp@charutarhealth.org Mobile : + 91 84600 63464

Abstract

Tetralogy of Fallot (TOF) is a common cyanotic congenital heart disease. Its surgical correction requires ventricular septal defect (VSD) closure and right ventricular outflow tract obstruction (RVOTO) relief, with transannular patch enlargement (TAPE) of the pulmonary valve. The first successful repair of TOF was reported in 1954 and consisted of closure of the VSD through a large right ventriculotomy, and RVOTO relief with TAPE of the pulmonary valve. To predict the intra-operative requirements and post-operative course of patients with this condition, various evaluation indices are available that can provide a good indication of patient prognosis. In this case report, we describe a novel pulmonary vein index (PVI) indicator that offers prognostic indications for pediatric cardiac patients who have undergone surgical correction of TOF.
KEYWORDS
Tetralogy of Fallot, Pulmonary vein index, McGoon ratio, early outcomes, congenital heart disease.

Introduction

Tetralogy of Fallot (TOF) is a cyanotic congenital heart disease seen in pediatric patients. Successful surgical correction of TOF was first performed in 1954 with the closure of the ventricular septal defect (VSD) through a large right ventriculotomy and relief of RVOTO by transannular patch enlargement (TAPE) [1,2].
Since then, treatments for the correction of TOF have enjoyed tremendous success [3,4]. The peri-operative mortality rate has reduced to 1.5% and there are good long-term outcomes due to the evolution of cardiopulmonary bypass techniques and peri-operative management. Although TOF can be lethal if untreated or incorrectly treated; it can have an excellent prognosis with timely surgical intervention.
The ideal TOF repair removes RVOTO sufficiently to prevent the progression of right ventricular hypertrophy. However, there are remarkable clinical differences between TOF patients, which may lead to overconfidence when formulating treatment decisions and predicting prognoses. TOF patients can experience prolonged postoperative recovery even when surgery is successful [5,6].
Reduced pulmonary blood flow (Qp) is the main cause of hemodynamic changes in TOF. Presently, preoperative evaluations of TOF children are performed using the McGoon ratio and the Nakata index but these have limitations. Both of these systems measure branch pulmonary arteries (PAs), which can yield fallacious results as pulmonary arteries are not typically cylindrical.Differences may be present as normal anatomic variations,or as a result of factors that may increase the stiffness of the vessels,and thus affect the ability of the PAs to alter their shape in response to changing conditions. In addition, poststenotic dilatation of branch PAs, the presence of major aortopulmonary collateral arteries (MAPCAs), and malformations may lead to misjudgments of Qp and further influence the mis-estimation of the patient’s condition and the determination of poor treatment decisions.Thus,understanding of the pulmonary artery anatomy is essential for all decisions -making in pediatric cardiac surgery.
In this study, we aim to demonstrate that the sizes of individual pulmonary veins (PVs) are a more accurate and sensitive indicator of Qp than PA size, especially in TOF patients [7,8]. The pulmonary vein index (PVI) is a new indicator based on the morphology of pulmonary veins. As Qp and the severity of TOF are inversely proportional, PVI may provide more precise predictions.
We review the case of a TOF patient who underwent complete repair in our institution and compare the prognostic abilities of PVI and the McGoon ratio and Nakata index in their predictions of early postoperative TOF outcomes.

Case Presentation

Our study was approved by the Institutional Ethics Committee (IEC-2) of the HM Patel Centre for Medical Care and Education, Anand,Gujarat vide Approval No.IEC/BU/2021/Cr.54/296 dated 27.11.2021. Written informed consent to use the patient’s data in this study was obtained from a parent or guardian prior to surgery.
The patient was male,aged 1 year,9 months and 23 days;weighed 8.5 kgs.Weight at birth was 2.5 kgs.The patient presented with TOF and confluent branch PAs,with a history of cyanotic spells.At surgery,the patient’s pre-operative oxygen saturation was 75 %.The patient had never undergone a surgical procedure prior to this.The Mc Goon ratio was 1.97,Nakata Index was 539.22 mm2/m2 and PVI was 368.12 mm2/m2.The operative data comprised a cardiopulmonary bypass(CPB)time of 152 min.The surgical strategy included combination of four procedures - Ventricular septal defect (VSD) closure, Right ventricular outflow tract (RVOT) resection,Trans-annular patch enlargement(TAPE),Atrial Septal Defect closure.A summary of the patient information is presented in Table2.
A cardiac computed tomography dynamic study revealed confluent branch PAs in our patient. The measurements for these were: right pulmonary artery: proximal 9 mm, distal 8.3 mm; left pulmonary artery: proximal 11 mm, distal 12 mm; main pulmonary artery: proximal (supra-valvular region) 7.7 mm, mid 9 mm, distal 12.2 mm.
Table – 1 Indices Used in the Evaluation of TOF Patients