Ventricular Scoop in Atrioventricular Septal Defect: Relevance to Simplified Single-Patch Method

The impact of surgical repair on left ventricular outflow tract in atrioventricular septal defect with common atrioventricular valve orifice

Objective

Although a narrow left ventricular outflow tract in atrioventricular septal defect is related to its intrinsic morphology, the contribution from the repair technique remains to be quantified.

Methods

A total of 108 patients with an atrioventricular septal defect with a common atrioventricular valve orifice were divided into 2 groups: 2-patch (N = 67) and modified 1-patch (N = 41) repair. The left ventricular outflow tract morphometric was analyzed by quantifying the degree of disproportion between subaortic and aortic annular dimensions (disproportionate morphometrics ratio was defined as ≤ 0.9). Z-scores (median, interquartile range) were further analyzed in a subset of 80 patients with immediate preoperative and postoperative echocardiography. A total of 44 subjects with ventricular septal defects served as controls.

Results

Before repair, 13 patients (12%) with an atrioventricular septal defect had disproportionate morphometrics (vs 6 [14%] ventricular septal defect P = .79), but the subaortic Z-score (-0.53, -1.07 to 0.06) was lower than the ventricular septal defect (0.07, -0.57 to 1.17; P < .001). After repair, both 2-patch (8 [12%] preoperatively vs 25 [37%] postoperatively; P = .001) and modified 1-patch (5 [12%] vs 21 [51%], P < .001) procedures showed a greater degree of disproportionate morphometrics. Both 2-patch (postoperatively -0.73, -1.56 to 0.08 vs preoperatively -0.43, -0.98 to 0.28; P = .011) and modified 1-patch (-1.42, -2.63 to -0.78 vs -0.70, -1.18 to -0.25; P = .001) procedures also demonstrated lower subaortic Z-scores postrepair. The postrepair subaortic Z-scores were lower in the modified 1-patch group (-1.42 [-2.63 to -0.78]) compared with the 2-patch group (-0.73 [-1.56 to 0.08]; P = .004). Low postrepair subaortic Z-scores (<-2) were observed in 12 patients (41%) in the modified 1-patch group and 6 patients (12%) in the 2-patch group (P = .004).

Conclusions

Surgical correction resulted in greater disproportionate morphometrics seen immediately postrepair. The impact on the left ventricular outflow tract was observed in all repair techniques, with a greater burden seen after modified 1-patch repair.

Video Abstract

This morphometric study in AVSD with common atrio-ventricular valve orifice confirmed further derangements of LV outflow tract morphometrics immediately after surgical repair.

The V-shaped double-layer patch technique for complete atrioventricular septal defect: A novel surgical technique

OBJECTIVE

Several surgical techniques for repair of a complete atrioventricular septal defect have been developed. However, the postoperative complications with these methods may lead to reoperation during follow-up. The aim of this report is to share our experience with a modified surgical technique for complete atrioventricular septal defect that has anatomic advantages postoperatively and could reduce the reoperation rate.

METHODS

Twenty-nine patients who underwent repair of complete atrioventricular septal defect using a V-shaped double-layer patch between April 2011 and September 2019 were retrospectively investigated.

RESULTS

There were no deaths (0%) and only 1 reoperation (3.4%) in the series. The aortic crossclamp and cardiopulmonary bypass times were 62.7 ± 16.0 minutes and 113.9 ± 25.9 minutes, respectively. The median follow-up duration was 5.1 years. To date, no significant residual ventricular septal defects have been detected and no left ventricular outflow tract obstruction has been seen on echocardiography in any patient. During follow-up, the left atrioventricular valve status was assessed as no incompetence in 9 patients (31.0%), trivial in 18 patients (62.1%), and mild in 2 patients (6.9%).

CONCLUSIONS

The V-shaped double-layer patch technique is a valuable surgical option for patients with complete atrioventricular septal defects. The midterm results in our series document excellent performance of this technique, which augments the area of the anterior valve of the left atrioventricular valve to make it closer to a normal mitral valve and may also reduce the need for reoperation.

Correlation of ventricular septal defect height and outcomes after complete atrioventricular septal defect repair

 

OBJECTIVES

There are limited data available on the height of the ventricular component of the septal deficiency (VSD) in patients undergoing complete atrioventricular septal defect (CAVSD) repair. VSD height may influence optimal choice of repair strategy with potential consequences for long-term outcomes. We aimed to measure VSD height using 2-dimensional echocardiography and review its association with postoperative outcomes.

METHODS

We retrospectively reviewed the preoperative echocardiograms of 45 consecutive patients who underwent CAVSD repair between May 2010 and December 2015 at a single centre. VSD height and left ventricular length on the four-chamber view were measured. Demographic details and early and late outcomes including reoperation and long-term survival were studied.

RESULTS

Twenty patients underwent modified single-patch repair and 25 patients underwent double-patch repair of CAVSD. VSD height in the modified single-patch group ranged from 4.2 to 11.7 mm and in the double-patch group ranged from 5.1 to 14.9 mm. Nine patients had a deep ‘scoop’ with a VSD height of >10 mm, (7 double patch, 2 modified single patch). VSD height did not correlate with a specific Rastelli classification. There was no significant difference in the VSD height (P = 0.51) or the VSD height-to-left ventricular length ratio (P = 0.43) between the 2 repair groups. There was no 30-day mortality. Eight patients required reoperation; however, VSD height was not a significant predictor of reoperation (hazard ratio 0.95, 95% confidence interval 0.69–1.33; P = 0.08).

CONCLUSIONS

There was no correlation between VSD height and risk of reoperation after CAVSD repair. A deep ventricular scoop is uncommon in CAVSD patients.

The role of abnormal subaortic morphometry as a substrate for left ventricular outflow tract obstruction following atrioventricular septal defect repair

OBJECTIVES

Although left ventricular outflow tract (LVOT) obstruction is a recognized risk after atrioventricular (AV) septal defect (AVSD) repair, quantitative assessments to define the substrate of the obstruction are lacking.

METHODS

Morphometric analyses were based on measurements from early 2-dimensional echocardiographic scans (within 3 months postoperatively) for 117 patients (82 CAVVO = common AV valve; 35 SAVVO = separate AV valve orifices), which were compared to 50 age/weight matched controls (atrial septal defect/ventricular septal defect). Late echocardiographic analyses were performed in 57 patients with AVSD (follow-up range, 1.2-10.7 years).

RESULTS

Adequate z scores (above -2.5) were observed in 109 (93%) patients with AVSD at the aortic annulus and in 89 (76%) with AVSD in the subaortic area. Compared to the control group, patients with AVSD had lower median z scores at the aortic annulus (-0.64 vs 0.60; P < 0.001) and the subaortic areas (-1.48 vs 0.59; P < 0.001), disproportionate subaortic/aortic annulus ratio <1.00 (67% vs 22%; P < 0.001), narrower annuloaortic-septal angle (94.0 vs 104.0; P < 0.001) and annuloaortic left AV valve angle (78.0 vs 90.0; P < 0.001). Compared to patients with CAVVO, those with SAVVO had narrower annuloaortic-septal angles (P = 0.022) that persisted at late analysis, with lower subaortic/aortic annular ratios (P = 0.039). In patients with CAVVO, lower early postoperative subaortic z scores were found following modified single-patch repairs (median -2.12 vs -1.02 in two-patch repairs; P = 0.004). A total of 6/117 (5%) patients (4 CAVVO, 5% and 2 SAVVO, 6%) required reoperations for LVOT obstruction (mean 6.9 years postoperatively), with no difference in morphology or types of operations.

CONCLUSIONS

Despite having adequate z scores, patients with AVSD demonstrated abnormal LVOT morphometrics early postoperatively. Besides intrinsic morphology, repair techniques may have an impact on postoperative LVOT morphometrics and requires further evaluation.

Atrioventricular Septal Defects: Pathology, Imaging, and Treatment Options

PURPOSE OF REVIEW

Atrioventricular septal defects (AVSD) represent a broad spectrum of congenital anomalies from simple to the most complex heart defects including some distinct types. Clinical presentation and timing of intervention differ by morphological subset and functional anatomy. Herein, we review morphological variations and characteristics that determine appropriate intervention and provide insights into functional anatomy based on detailed three-dimensional (3D) assessment of AVSDs.

RECENT FINDINGS

The understanding of functional morphology of AVSDs has improved significantly with detailed 3D echocardiographic evaluation of the atrioventricular junction and valve morphology. As prenatal detection of AVSDs has increased significantly, it has become the most common fetal cardiac diagnosis enabling antenatal counseling and delivery planning. Advances in diagnosis and perioperative care have resulted in optimal outcomes. The diagnosis and management of AVSDs have improved over the years with enhanced understanding of anatomy and perioperative care resulting in optimal short and long-term outcomes.

Modified-Single Patch vs Double Patch Repair of Complete Atrioventricular Septal Defects

Biventricular repair of complete atrioventricular septal defect (CAVSD) is largely achieved using the double-patch (DP) or modified single-patch (MSP) techniques in the current era; however, long-term results following MSP repair are not well defined. We aimed to compare long-term outcomes including reoperation and mortality after CAVSD repair using DP and MSP techniques, and identify the risk factors associated with adverse outcomes. A retrospective cohort study was performed including all patients who underwent CAVSD repair using DP and MSP techniques at our institution between 17 May 1990 and 14 December 2015. Demographic details, early (≤30 days) and late (>30 days) outcomes (reoperation, mortality) were studied. Competing risks analysis with cumulative incidence function was used for survival analyses. Overall, 273 consecutive patients underwent CAVSD repair (120 DP and 153 MSP) and 41 patients required reoperation during follow-up. Competing risks analysis showed no association between repair technique and reoperation (P = 1.0) or mortality (P = 0.9). Considering competing risks due to mortality, the cumulative incidence of reoperation at 5, 10, and 15 years was 14%, 17%, and 17% for DP and 12%, 13%, and 16% for MSP, respectively. Non-Down syndrome and moderate or greater left atrioventricular valve regurgitation were predictors for reoperation. Pulmonary artery banding was predictive of mortality, though strongly associated with earlier surgical era. Median follow-up duration was 8.0 years (interquartile range 3.9-20.8) for DP and 11.6 years (interquartile range 5.4-16.1) for MSP (P = 0.4). Event-free survival is similar after DP and MSP repair of CAVSD indicating either repair technique can be safely utilized.

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

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 Canal Defect: Towards a More Physiological Repair

We describe a more physiological technique of complete atrioventricular septal defect repair which restores normal heart anatomy with the offset between the insertions of the mitral and tricuspid valves. This technique overcomes the drawbacks of the previous approaches, and may improve surgical outcomes, particularly in small infants with high ventricular septal defect component or dextroposed aorta.

Surgical repair of complete atrioventricular defect (Nunn technique)

Two procedures have been traditionally used for the surgical repair of complete atrioventricular canal. The single-patch technique includes the division of valve leaflets, and the use of one patch to close the ventricular and the atrial septal defects, whereas the double-patch technique uses two separate patches, without the division of the bridging leaflets. Between 1997 and 2007, another technique emerged, the modified single-patch technique, or the 'Australian' technique, whereby the ventricular septal defect (VSD) is closed by the direct apposition of the bridging leaflets against the crest of the defect. Because of the absence of the ventricular septal patch, concerns have been raised about the possible left ventricular outflow tract obstruction (LVOTO), or atrioventricular valve (AVV) distortion, especially in case of a deep VSD, or if the defect extends superiorly. The results of the modified single-patch technique in terms of mortality, immediate and long-term AVV function and LVOTO have been similar to the standard techniques in most reports. This article will describe in detail the operative technique and review the relevant literature.

Modified single patch: are we still worried about subaortic stenosis?

BACKGROUND

When the modified single-patch technique for atrioventricular septal defect (AVSD) repair was introduced by Dr Benson Wilcox, there was concern that these patients might be at risk for late subaortic stenosis and left ventricular outflow tract obstruction (LVOTO). This review evaluated our modified single-patch population for LVOTO in the postoperative period.

METHODS

Between January 2000 and 2013, 77 infants underwent AVSD repair with a modified single-patch technique. Median age was 4.2 months, and median weight was 5 kg. Eight patients had a prior repair of coarctation of the aorta via left thoracotomy in the newborn period.

RESULTS

The median hospital stay was 10 days. No patient required a pacemaker. The mean and median follow-up times were 4.6 and 3.7 years, respectively. Only 2 patients (2.5%) required reoperation for LVOTO; both had prior repair of coarctation of the aorta (2 of 8 vs 0 of 69, p = 0.01). A discrete fibrous subaortic membrane developed in the first patient that required resection at 3 and 7 years after repair. The other patient had LVOTO from accessory chordae of the left atrioventricular valve and required mitral valve replacement 5 months after repair. One early death occurred at 4 months postoperatively due to liver failure related to hyperalimentation.

CONCLUSIONS

At intermediate term follow-up, LVOTO does not appear to be a significant postoperative issue after modified single-patch repair of AVSD. Coarctation of the aorta was the most significant predictor of late LVOTO after repair of AVSD with the modified single-patch technique.

Reoperation for left ventricular outflow tract obstruction after repair of atrioventricular septal

Left ventricular outflow tract obstruction (LVOTO) is an important source of morbidity and mortality after repair of atrioventricular septal defect (AVSD). The intrinsic anatomy of the left ventricular outflow tract in AVSD is complex and predisposes to the development of LVOTO. LVOTO after repair of AVSD usually involves multiple levels and sources of obstruction, and surgical intervention must address each component of the obstruction. This includes fibromuscular obstruction, septal hypertrophy, and valve related sources of obstruction. Special attention is also directed to the anterolateral muscle bundle of the left ventricle, a well defined but under recognized feature of the left ventricular outflow tract in AVSD. It is present in all patients with AVSD, and resection of a hypertrophic anterolateral muscle bundle of the left ventricle should be incorporated in all operations for LVOTO after repair of AVSD. LVOTO after repair of AVSD has several unique features that must be taken into consideration to maximize outcome after surgical intervention. These include anatomic factors, technical aspects of surgical intervention, and proper selection of the operation used for relief of LVOTO.

Modified single-patch compared with two-patch repair of complete atrioventricular septal defect

BACKGROUND

We compared the outcomes of modified single-patch and two-patch surgical repair of complete atrioventricular septal defect (CAVSD) on left ventricular outflow tract (LVOT) diameter and on left atrioventricular valve (LAVV) coaptation.

METHODS

We reviewed retrospectively postoperative 2-dimensional echocardiograms of all CAVSD patients who underwent modified single-patch or two-patch repair between 2005 and 2011. We measured the leaflet coaptation length of the LAVV in the apical four-chamber view. The LVOT was measured in the long axis view.

RESULTS

Fifty-one patients underwent CAVSD repair at a median age of 4 months (range, 1 to 9 months) (single-patch, n=29; two-patch, n=22). The images from 46 echocardiograms were adequate for analysis. Modified single-patch repair required significantly shorter bypass time (102.0±33.6 vs 152.9±39.5 minutes, p<0.001) and ischemic time (69.0±21.7 vs 106.9±29.7 minutes, p<0.001) than did two-patch repair. The indexed coaptation length of the septal and lateral leaflets was not different between single-patch and two-patch (3.1±2.3 vs 4.1±3.1 mm/m2, p=0.25; 2.3±2.3 vs 3.3±3.0 mm/m2, p=0.21). Indexed LVOT diameter was not different in the two groups (26.1±5.2 vs 28.5±7.1 mm/m2, p=0.22). There was no hospital or late death during the median follow-up time of 35 months (range, 1 to 69 months). Five patients underwent reoperation after single-patch repair (3 with residual ventricular septal defect [VSD] and LAVV regurgitation, 1 with residual VSD, 1 with pacemaker implantation). After the two-patch repair, 1 patient required reoperation for a residual VSD and right atrioventricular valve regurgitation (p=0.22).

CONCLUSIONS

The modified single-patch repair was performed with significantly shorter bypass time and myocardial ischemic time. The postoperative LVOT diameter and LAVV leaflet coaptation length were not significantly different between techniques.

Outcome after repair of atrioventricular septal defect with tetralogy of Fallot

BACKGROUND

Long-term outcomes of repair of tetralogy of Fallot associated with complete atrioventricular septal defect are seldom reported. We report our survival and reintervention outcomes over a 29-year time period.

METHODS

Between March 1979 and April 2008, 61 patients with the combined cardiac defect of atrioventricular septal defect and tetralogy of Fallot were surgically managed. Trisomy 21 was present in 49 (80%) patients. Primary repair was performed in 36 patients at a median age of 9 months (range, 1 month to 16 years), whereas 25 patients had initial palliation by systemic-pulmonary shunt at a median age of 21 months (range, 0 days to 36 years). Thirty-one (51%) patients had a transannular patch. Fifty-three patients required right ventriculotomy for relief of the right ventricular outflow tract obstruction. Four patients had a right ventricle-pulmonary artery conduit with a homograft. Relationships between patient characteristics and outcome variables were examined using Kaplan-Meier survival curves; comparisons were performed using the log-rank test.

RESULTS

Median follow-up was 4.7 years. A total of 12 patients died during the course of follow-up: 4 (7%)deaths within 30 days of surgery and 8 late deaths (range, 4 months to 9.9 years after repair). Since 2000, there have been no early deaths and 1 late death, 5 months after the operation. The estimated survival at 5 years after definitive repair was 82% (95% confidence interval, 69%, 90%). Time to death was not associated with any patient or surgical variables examined. Overall, 30% of the survivors required a reoperation. The type of reoperations was on the mitral valve (4 repairs, 4 replacements) and 7 pulmonary valve replacements. We did not find an effect of era on mortality (P = .23 for comparison of 1979-1989, 1990-1999, and 2000-2008). The percentage of patients with primary repair did not change during the different quartiles. The estimated freedom from reoperation at 5 years was 80% (65%, 90%). Time to reoperation was shorter for patients with a conduit (P = .01).

CONCLUSIONS

Excellent long-term survival was achieved after repair of tetralogy of Fallot associated with complete atrioventricular septal defect. Palliation and primary repair resulted in comparable outcomes; as such, primary repair is favored. The choice of right ventricular outflow tract reconstruction affects the need for reoperation.