A review of the Nunn modified single patch technique for atrioventricular septal defect repair

Abstract

Atrioventricular septal defect (AVSD) is a common congenital cardiac surgical problem. Over the years, younger and smaller infants are having operations for this condition before irreversible cardio pulmonary changes occur. Traditionally a single or two patch techniques have been used to repair this defect. However, in the past two decades an innovative method of modified single patch technique popularized by Dr. Graham Nunn has gained worldwide popularity. This review discusses the origin, surgical principles, technique and outcomes of this method, popularly known as Nunn or Australian technique. Research comparing the modified single patch technique to classic single and double patch techniques has shown good preservation of atrioventricular valve function, no residual ventricular septal defect (VSDs), low incidence of left ventricular outflow obstruction, preserved conduction, easy reproducibility, and improved perioperative and long-term mortality.

Complete Atrioventricular Septal Defect: Two-Patch Techniques and Modified Single Patch, Application-Outcomes.

“…Reoperation rates due to the AV valve are 2.2% and 7.2%, and pacemaker rates are 0.4% and 1.9%, respectively. [26][27] In our series, while there was no difference in terms of mortality and pacemaker implantation, our overall pacemaker average was observed to be above the average indicated in the literature (4%). While the AV block risk was 2-2.5% in general in the TPT, it is between 0-1% in many series in which the MSP is applied.…”

“…While Geoffrion et al presented this rate as 0.6% in their series, the rate was reported to be 0 % in Nunn's series in the MSP technique. [26][27] In conclusion, when the modified single-patch technique is compared with the two-patch technique in this series, the CPB-ACC time is shorter in favor of MSP, the VSD is smaller in accordance with the nature of the technique, LAVV regurgitation is less, and, accordingly, the risk of AV valve reoperation is lower. Therefore MSP technique may be prefeferred in patients with suitable VSD diameter and localization in CAVSD.…”

“…While the AV block risk was 2-2.5% in general in the TPT, it is between 0-1% in many series in which the MSP is applied. 26 The most common cause of reoperation after additional AV valve repair is recurrent LAVV regurgitation (9-17%). [28][29] However, as can be seen from the above-mentioned rates, the reoperation rates (2.2%) are quite low in the MSP.…”

“…The mortality in reoperations due to left AV valve residual defect and other reoperation causes is about 9.8%. 26 The rate of LVOTO is usually 4.2%. While Geoffrion et al presented this rate as 0.6% in their series, the rate was reported to be 0 % in Nunn's series in the MSP technique.…”

Atrioventricular Septal Defect with Intact Interatrial Septum. Case Report

“…The long-term prognosis depends on the evolution of a residual mitral regurgitation [12] [13]. It may be favorable because repair in this area of Down syndrome is more favorable [3] [5].…”