Left ventricular outflow tract obstruction after partial atrioventricular septal defect repair

Surgical Treatment of Atrial Septal Defects

Atrial septal defects (ASDs) are among the most prevalent congenital cardiac malformations. Closure of the defect and repair of associated cardiac malformations are typically indicated if an ASD is hemodynamically significant or symptomatic. This narrative review aims to summarize key aspects of surgical ASD closures. A non-systematic literature review was conducted to cover surgically relevant aspects of (developmental) anatomy, morphology, and treatment. ASDs result from diverse developmental alterations, leading to subtype-specific associated cardiac malformations, meaning surgical therapy varies accordingly. Presently, surgical repair yields excellent outcomes for all ASD subtypes, with minimally invasive approaches, especially in adults, increasingly employed for ASD closure. Surgical ASD repair is safe with excellent results. However, familiarity with ASD subtypes and typically associated lesions is crucial for optimal patient management.

Surgical treatment of recurrent subvalvular discrete membrane and left ventricular outflow tract stenosis in an adult patient with a history of congenital cardiac surgery

Left ventricular outflow stenosis can develop at the supravalvular, valvular, and subvalvular levels. Resection of strictures at the diffuse subvalvular level is very difficult. In such pathologies, Konno-Rastan procedure provides very successful solutions as an anterior aortoventriculoplasty method. In this article, we performed anterior aortaventriculoplasty surgical treatment for tunnel type left ventricular outflow tract stenosis, recurrent subvalvular discrete membrane, and aortic regurgitation in an adult patient with a history of partial atrioventricular septal defect repair and subvalvular discrete membrane resection operation in early childhood. The Konno-Rastan procedure, which we applied to the redo case, which is rarely used in adult patients and rarely seen in the literature, is shared.

Case Report: Using Medtronic AP360 mechanical prosthesis in mitral valve replacement for patients with mitral insufficiency after primum atrial septal defect repair to reduce left ventricular outflow tract obstruction risk

Background

Atrial septal defect is one of the most common congenital heart diseases in adults. Primum atrial septal defect (PASD) accounts for 4%-5% of congenital heart defects. Patients with PASD frequently suffer mitral insufficiency (MI), and thus, mitral valvuloplasty (MVP) or mitral valve replacement (MVR) is often required at the time of PASD repair. Unfortunately, recurrent unrepairable severe mitral regurgitation can develop in many patients undergoing PASD repair plus MVP in either short- or long-term after the repair surgery, requiring a re-do MVR. In those patients, the risk of left ventricular outflow tract obstruction (LVOTO) has increased.

Case presentation

We present five such cases, ranging in age from 24 to 47 years, who had a PASD repair plus MVP or MVR for 14-40 years while suffering moderate to severe mitral regurgitation. Using Medtronic AP360 mechanical mitral prostheses, only one patient experienced mild LVOTO.

Conclusions

The use of Medtronic AP360 mechanical mitral prostheses to perform MVR in patients with MI who had a history of PASD repair can potentially reduce the risk of LVOTO. Long-term follow-up is required to further confirm this clinical benefit associated with AP360 implantation in patients with PASD.

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.

Surgical repair of partial atrioventricular septal defect

Objective:

To review the results of surgical correction of partial atrioventricular septal defect and associated cardiac comorbidities.

Methods:

Retrospective case analysis of electronic database of department of paediatrics cardiac surgery, CPEIC, Multan was done. Forty consecutive patients operated for partial atrioventricular septal defect repair from September 2011 to October 2016 were included. Mean age was 14.67±7.96 years. 60% (24) patients were male. Regarding echocardiographic findings, pre-operatively 40% (n=16) had mild, 47.5% (19) had moderate and 12.5% (n=5) had severe mitral valve regurgitation. There were 25% (n=10) patients having moderate tricuspid valve regurgitation. Pulmonary hypertension was moderate in 57.5% (n=23) cases and severe in 7.5% (n=3) cases. Among other associated lesions 10% (n=4) patients had secundum ASD, pulmonary artery stenosis was seen in 5% (n=2) patients. Another 5.0% (n=2) patients had bilateral SVCS. While one patient had PDA and one patient had associated common atrium.

Results:

Post-operatively there were 19 cases (47.5%) having no mitral valve regurgitation while 18 (45%) patients showed mild and 7.5% (n=3) had moderate mitral valve regurgitation. Only one case had moderate tricuspid valve regurgitation post-operatively, while 22.5% (n=9) cases had mild tricuspid regurgitation. Complete heart block and left sided brain infarct developed in one case. There was no mortality, reoperation, residual atrial shunt or left ventricular outflow tract obstruction.

Conclusion:

Repair of partial AV canal carries good overall results with minimal mortality however earlier repair is suggested to reduce post- operative morbidity further.

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.

Secondary subaortic stenosis after patch closure of subarterial ventricular septal defect

Subaortic stenosis usually occurs without a previous heart operation, however, it can occur after heart surgery as well, with a condition known as a secondary subaortic stenosis (SSS). SSS has been reported after surgical repair of several congenital heart defects. There are only a few recorded cases of SSS after repair of ventricular septal defect (VSD). Here we report a rare case of SSS that occurred 3 years after surgical repair of subarterial VSD. A follow-up echocardiogram is essential for detecting SSS caused by the newly developed subaortic membrane in patients who had cardiac surgery.

Reoperations After Repair of Partial and Complete Atrioventricular Septal Defect

The most common cause of reoperation following repair of atrioventricular septal defect (AVSD) is left atrioventricular valve regurgitation. However, reoperation for subaortic obstruction is required in some, especially after initial repair of partial AVSD. Etiology of reoperation and late outcome were evaluated. Between 1962 and 2007, 146 patients (59 male) underwent reoperation at the authors' institution after prior repair of partial (n = 96) and complete (n = 50) AVSD. Median age at reoperation after repair of partial AVSD was 26 years (range, 10 months to 71 years) and 4.5 years (range, 53 days to 38 years) after repair of complete AVSD. The 3 most common indications for reoperation included left atrioventricular (AV) valve regurgitation in 105 patients, subaortic stenosis in 29, and right AV valve regurgitation in 21. The most common procedures performed included left AV valve repair in 59 (40%) patients, left AV valve replacement in 56 (38%), subaortic fibrous resection/myectomy in 24 (16%), and right AV valve surgery in 19 (13%). Freedom from subsequent reoperation at 10 years was 48% after initial repair of complete AVSD and 84% after initial repair of partial AVSD. During late follow-up, 10-year actuarial survival was 91% and 77% after initial repair of complete and partial AVSD, respectively. The most common indication for reoperation after initial repair of partial or complete AVSD is left AV valve pathology; left ventricular outflow tract obstruction was more common in partial AVSD. Although freedom from subsequent reoperations is higher after initial repair of partial AVSD, these patients have reduced long-term survival when compared with complete AVSD.

Partial atrioventricular canal: pitfalls in technique

Partial atrioventricular (AV) canal represents approximately 25% of all AV septal defects. While often grouped with secundum ASD from the perspective of cardiopulmonary physiology, clinical presentation, and timing of surgical correction, their optimal management truly requires an understanding of their anatomic similarities to other forms of common AVC defects. By most measures, outcomes for surgical management of partial AV canal has improved over the last four decades, though some aspects of these defects continue to pose important challenges. Current experience has witnessed the reduction in early mortality and only rare complete heart block. Left AV valve dysfunction remains the most common indication for reoperation (10%) with LVOT stenosis the next most common reason (10% to 15% incidence, 5% to 10% reoperation rate). It is important to understand in this population that postoperative left AV valve problems and LVOT stenosis may be intimately linked, both from an etiologic standpoint, and with respect to their management.

Complex atrioventricular canal

Complex forms of atrioventricular (AV) canal (C) such as; AVC with left ventricular outflow tract obstruction, tetralogy of Fallot with complete AVC, double orifice left AV valve, unbalanced complete AVC, and single ventricle patients with common AVC valve require careful preoperative planning and special techniques. This review will explore these technical modifications and outcomes for repair of complex variants of AVC. Optimal results will be achieved using an individually tailored approach that is guided by careful evaluation of the preoperative studies, precise operative technique, and intraoperative assessment of the reconstructed AV valve, as well as a willingness to re-intervene should the postoperative course not proceed as anticipated.

Utilization of double-orifice valve plasty in correction of atrioventricular septal defect

BACKGROUND

Atrioventricular valve regurgitation represents the principal indication for reoperation after repair of atrioventricular septal defect. Deciding how to correct atrioventricular valve regurgitation is challenging in some cases because of the complexity of the anatomic features. This report deals with our surgical experience in using a double-orifice valve plasty technique in cases with atrioventricular septal defect.

METHODS

From August 2002 to August 2004, 8 patients underwent double-orifice valve plasty in surgical correction of atrioventricular septal defect. Anatomic types were partial (6 patients), intermediate (1 patient), and complete (1 patient). After the mitral cleft was closed, moderate to severe atrioventricular valve regurgitation was still present in these patients. Double-orifice valve plasty was used in the mitral valve in 7 patients and in the tricuspid valve in 1.

RESULTS

No hospital deaths or postoperative morbidity occurred. The follow-up ranged from 6 months to 30 months (median, 14.4 months). No or trivial atrioventricular valve regurgitation was found in 6 patients and mild atrioventricular valve regurgitation was present in 2.

CONCLUSIONS

Double-orifice valve plasty is an easy and effective additional procedure for children and for adult patients who have moderate or severe atrioventricular valve regurgitation after repair of atrioventricular septal defect.

The Southern Thoracic Surgical Association 50th anniversary celebration: the impact of STSA pediatric cardiothoracic surgery manuscripts on surgical practice

BACKGROUND

Members of the Southern Thoracic Surgical Association (STSA) have presented important pediatric cardiothoracic surgery papers at the annual meetings over the last 50 years. In order to determine the influence of these presentations on the practice of surgery, a review was undertaken. Early papers were characterized by emerging advances in open-heart surgery, anatomic congenital heart studies, and electrophysiologic discoveries that extended life with pacemakers. Later years were characterized by innovative myocardial preservation methods, improved cardiopulmonary bypass techniques, expanded homograft availability, emphasis on accurate repairs, intraoperative transesophageal echocardiography, and cardiopulmonary transplantation.

METHODS

All but one of the scientific programs of the annual meetings (that of 1964) were located. The programs were reviewed and 180 presentations were identified on topics in congenital heart disease, pediatric thoracic disease, and pediatric thoracic wall abnormalities. Of those 180 oral presentations, 155 manuscripts (86%) were eventually published or in press and available for critical review and analysis. Manuscripts were grouped by diagnosis or therapeutic intervention. We determined a "cumulative citation frequency" (CCF), which measures the number of times an article is cited in the bibliography of related papers in the universe of participating journals. The selected manuscripts were compared with the historic landmark contributions and the existing trends at the time, and the number of articles both by individual authors and from institutions were tallied.

RESULTS

Grouping by authors and institutions showed that 100 of 155 pediatric cardiothoracic manuscripts (65%) originated from 13 institutions. The CCF for the 20 leading articles ranged from 26 to 93.

CONCLUSIONS

This historical STSA 50-year record of pediatric cardiothoracic advances was accomplished in a milieu of collegial respect and camaraderie. Our annual meetings over the years have provided a venue for thoracic surgeons to share their ideas, innovations, and scientific inquiry. These contributions have significantly affected the practice of pediatric cardiothoracic surgery. The STSA has worked for 50 years and we trust that it will work for another 50 years and beyond.

Discrete subaortic stenosis: incidence, morphology and surgical impact of associated subaortic anomalies

BACKGROUND

The association between discrete subaortic stenosis and other subaortic anomalies is a well known but rarely reported occurrence. The aim of this study is to define the incidence, morphology, and surgical impact of associated anomalies of the left ventricular outflow tract in children operated on for discrete subaortic stenosis.

METHODS

Between 1994 and 2000, 45 consecutive children were operated on for discrete subaortic stenosis. Patients were divided in two groups according to the obstructive lesion detected by echocardiography.

RESULTS

A localized shelf was found as an isolated lesion in 31 patients (group A), whereas additional subaortic anomalies were found in 14 cases (31%) and were multiple in 5 cases (group B). The anomalies included anomalous septal insertion of mitral valve (7 cases); accessory mitral valve tissue (2 cases); anomalous papillary muscle (2 cases); anomalous muscular band (8 cases); and muscularization of the anterior mitral valve leaflet (1 case). Cardiopulmonary bypass and aortic cross-clamping times were significantly shorter in group A. There were no operative deaths nor major complications or deaths during follow-up. A gradient of 15 mm Hg or more was found at follow-up in 5 cases whereas aortic regurgitation was estimated to be not clinically significant in all but 1 patient. Six cases of recurrent subaortic stenosis were found in our series, 3 of them with other subaortic anomalies.

CONCLUSIONS

This study shows that discrete subaortic stenosis can often be associated with other subaortic abnormalities. Surgical treatment of these anomalies produces excellent early and mid-term relief of obstruction without any increase in mortality and morbidity.