Author Reply to Commentary: Further elaboration of the "V-shaped double-layer patch technique"

See Commentary on page 1244. See Commentary on page 1244. I feel greatly honored to read the commentary by Dr Carl L. Backer.1Backer C.L. Commentary: one-patch, two-patch, V-patch?.J Thorac Cardiovasc Surg. 2023; 165: 1244-1245Abstract Full Text Full Text PDF Scopus (1) Google Scholar I think it is necessary to further elaborate on several situations mentioned by Dr Carl L. Backer. So far, there have been no accurate epidemiologic statistics of complete atrioventricular septal defect (CAVSD) in China. According to some published literature from other centers in China,2Li D. Fan Q. Iwase T. Hirata Y. An Q. Modified single-patch technique versus two-patch technique for the repair of complete atrioventricular septal defect: a meta-analysis.Pediatr Cardiol. 2017; 38: 1456-1464https://doi.org/10.1007/s00246-017-1684-8Crossref PubMed Scopus (14) Google Scholar, 3Xie L. Huang C. Zhao T. Yang J. Wu Z. Yang Y. et al.Surgical repair of complete atrioventricular septal defect in 86 patients.J Chin Physician. 2016; 18: 1152-1155Google Scholar, 4Shi Z. Qiu Y. Li J. Qi J. Yu J. Shu Q. Clinical analysis of surgical treatment of complete atrioventricular septal defect.Chin J Pediatr Surg. 2021; 42: 1084-1089Google Scholar surgical age in China is much greater than that in European and American countries, and there are fewer patients with Down syndrome, which may be related to our understanding and development of the treatment of CAVSD. Since 2011, the V-shaped double-layer patch technique has been applied for all CAVSDs in our center. Speaking of the incision of the bridging leaflets, not all patients need to do this. Operation-only patients with Rastelli type C were involved for the patch to gain access to the anterior portion of interventricular defect. For patients with Rastelli type A CAVSD, the incision of the bridging leaflets was not necessary. In addition, for patients with Rastelli type B, the incision was seldom required. We had altogether 5 cases of Rastelli type C and 1 case of Rastelli type B who received incision of bridge leaflets. There was no occurrence of bridge leaflet dehiscence during the follow-up period. In the classical single-patch and 2-patch techniques, the suture line of the left atrioventricular valve (LAVV) is affected by the forces from 3 different directions: from the patch convex toward the right ventricle formed by the force deviation because of the greater left ventricular pressure than the right ventricular pressure, from the patch convex toward the right atrium formed by the force deviation because of the greater left atrial pressure than the right atrial pressure, and from the acting force formed because of the greater left ventricular pressure than the right ventricular pressure during systole. Therefore, dehiscence at that suture line is likely to occur. In the V-shaped double-layer patch technique, the left pericardial patch and the LAVV are sutured to form the arc surface similar to the normal atrioventricular valve. The suture line bears the pressure only from the left ventricle to left atrium. The purpose of CAVSD surgical repair is to repair the defect and restore the function of the atrioventricular valve. Repairing the AV valve is the key to the success of the operation. The classical single-patch, 2-patch, and modified single-patch techniques may give rise to (1) displacement of the LAVV and subvalvular structures, (2) continuous traction of LAVV to the right side because the greater pressure in left heart makes the patch concave on the left side, (3) reduction of the LAVV area by leaflet suture, and (4) limitation of LAVV and right atrioventricular valve orifice area because of the separation of the common atrioventricular valve annulus in the same plane. My original intention of designing this surgical technique was to find a simple technique that could reconstruct the atrioventricular valve similar to the normal valve. I noticed that some CAVSD cases had no or only mild atrioventricular valve regurgitation before operation, and the common atrioventricular valve regurgitation may be characterized by progressive aggravation. I consider the hemodynamics of an atrioventricular valve to be similar to the aerodynamics of a parachute. Changing the original state of the atrioventricular valve and subvalvular structures is as bad as changing the parachute's canopy shape and cord length. In addition, severe atrioventricular valve regurgitation and left ventricle outflow tract stenosis were less common in partial atrioventricular septal defect, and the long-term prognosis was much better than CAVSD. Therefore, the atrioventricular valve structure has a certain hydrodynamic rationality, and it is crucial to maintain its original shape and position. In the V-shaped double-layer patch technique, the left patch increased the leaflet area while maintaining the original shape and position of the atrioventricular valve and subvalvular structures. In addition, the right patch repaired the defect, which avoids continuous traction of LAVV to the right side caused by the higher pressure in left heart. The V-shaped double-layer patch technique was applied also in the National Center for Cardiovascular Disease and Fuwai Hospital, Beijing, China. The surgeon evaluated this technique as simple and effective. I hope, with more applications of the V-shaped double-layer patch technique, more techniques will be discovered to benefit more patients. Commentary: One-patch, two-patch, V-patch?The Journal of Thoracic and Cardiovascular SurgeryVol. 165Issue 3PreviewIt appears that the discussion regarding the optimal repair strategy for complete atrioventricular (AV) septal defect now has another option. This occurs just when we thought that the debate regarding the 2-patch versus modified single-patch technique was finally closed!1 Dr Sun and colleagues2 from the Cardiac Center of Guangdong Women and Children's Hospital have described a novel strategy for the repair of complete AV septal defect. The technique employs a folded V-shaped pericardial patch that augments the left-sided AV valve with pericardium. Full-Text PDF