Morphologic features of atrioventricular septal defect with only ventricular component: Further observations pertinent to surgical repair

Case report: morphological challenges to surgical repair in complete atrioventricular septal defect with isolated ventricular component

We describe a trisomy 21 patient with postnatal diagnosis of atrioventricular septal defect with isolated ventricular component who had a complicated post-surgical course following complete repair. Clinical outcomes included moderate-severe residual atrioventricular valve regurgitation needing re-operation, complete heart block leading to pacemaker insertion, seizures secondary to subdural haemorrhages, and chylothorax. We describe the surgical considerations specific to this cardiac morphology.

Atrioventricular Septal Defect With Tetralogy of Fallot and Exclusive Shunting at the Ventricular Level

Atrioventricular septal defect (AVSD) with shunting restricted to the ventricular level is a rare form of AVSD. To our knowledge, this shunting pattern has not been reported in AVSD with tetralogy of Fallot. We report a child with this unusual combination who underwent a successful single-stage repair at two years of age.

Atrioventricular septal defect with an absent or tiny ostium primum defect: a case series of three surgical cases

Although atrioventricular septal defects are categorized according to the anatomical atrioventricular orifice, the location of the intracardiac shunt in atrioventricular septal defects is important from a surgical perspective. Herein, we report three cases of atrioventricular septal defects with a small or no ostium primum defect. Case 1 (3-month-old girl) was diagnosed preoperatively with a ventricular septal defect, secundum atrial septal defect, and mitral valve cleft. After the operation, the diagnosis was corrected to an atrioventricular septal defect and was repaired completely. Case 2 (9-year-old girl) underwent pulmonary artery banding for a ventricular septal defect with a straddling mitral valve. After the experience with Case 1, we realized similarities between Cases 1 and 2. Therefore, we corrected the diagnosis to atrioventricular septal defect and achieved definitive repair. Based on these experiences, we accurately diagnosed Case 3 (3-month-old boy) with an atrioventricular septal defect. This variant is poorly known; however, proper morphological understanding is necessary to facilitate anatomical repair and prevent postoperative atrioventricular blocks. Some cases of this variant may be diagnosed as a ventricular septal defect with straddling mitral valve and are unable to receive definitive repair. The direction of the cleft, absence of atrioventricular valve offsetting, and trileaflet of the left atrioventricular valve all seem useful for making a diagnosis, and these can be easily confirmed by echocardiography.

Complete atrioventricular septal defect with absent or diminutive primum component: Incidence, anatomic characteristics, and outcomes

BACKGROUND

Repair of complete atrioventricular septal defect with absent or diminutive primum defect is challenging because of atrial septal malposition and abnormal anatomy of the left atrioventricular valve. We sought to define the incidence, anatomy, and surgical outcomes of this entity.

METHODS

We identified all patients in our institutional database presenting for complete atrioventricular septal defect repair from 2006 to 2018. Operative reports and echocardiograms were reviewed to determine the presence and size of the primum defect, atrioventricular valve anatomy, degree of atrioventricular valve regurgitation, repair method, and complications, including reoperation for atrioventricular valve regurgitation. Functionally univentricular patients and those receiving repair at an outside institution were excluded.

RESULTS

Of 183 patients with complete atrioventricular septal defect, absent/diminutive primum defect occurred in 16 patients (8.7%; 10 absent, 6 diminutive). Six patients (38%) had leftward malposition of the atrium septum on the common atrioventricular valve. The rate of reoperation for left atrioventricular valve regurgitation was 31% (3 early, 2 late), for which preoperative predictors included leftward malposition of the atrial septum onto the common atrioventricular valve (4/6 patients with malposition required reoperation, P = .036, Fisher exact test). One patient exhibiting this risk factor died. The overall rate of moderate or greater left atrioventricular valve regurgitation on the most recent postoperative echocardiogram was 13% (2/16 patients; median follow-up, 141 days; range, 3-2236 days).

CONCLUSIONS

Complete atrioventricular septal defect with absent or diminutive primum defect is a unique variant of complete atrioventricular septal defect for which the risk of reoperation for left atrioventricular valve regurgitation after complete repair is high and risk factors include leftward malposition of the atrial septum on the common atrioventricular valve.