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

The Congenital Heart Surgeons' Society Presidents and Their Contributions

The Congenital Heart Surgeons' Society (CHSS) was founded by 16 congenital heart surgeons in 1973, who endeavored to share their clinical advances in an informal setting that would stimulate honest and forthright discussions. As the Society grew, prospective studies were organized from a centralized data center that was established and based first in Birmingham, Alabama, thence to Toronto, and recently in a collaboration between Toronto and the Cleveland Clinic. These studies formed the basis for a myriad of outcomes reports that favorably impacted surgical results. The Kirklin-Ashburn Fellowship was created and endowed by the membership which has been successful in training many congenital heart surgeons. The CHSS was then incorporated into a 501(c) (3) not-for-profit organization with bylaws, officers, and committees in 2002. Increased membership followed. The CHSS has become the face of congenital heart surgery in North America by affiliating with the World Journal for Pediatric and Congenital Heart Surgery, having one designated member on the American Board of Thoracic Surgery, and hosting joint meetings with the European Congenital Heart Surgeons Association. Since 2002, 11 presidents have been elected for two-year terms and have guided the advances that have been achieved by the CHSS. Their contributions and achievements are highlighted in chronological order.

Long-term results following atrioventricular septal defect repair

BACKGROUND

Atrioventricular septal defects (AVSD) represent 4-7% of congenital cardiac malformations. Definitive early repair is favored over prior pulmonary artery banding and delayed definitive repair in many centers. The aim of this study was to analyze long-term outcomes following AVSD repair over a 21-year period.

METHODS

A total of 202 consecutive patients underwent surgical AVSD correction between June 1999 and December 2020. Surgery was performed using the double-patch technique. The study data were prospectively collected and retrospectively analyzed. Primary outcomes were In-hospital mortality and overall long-term freedom from reoperation.

RESULTS

Median age at operation was 120 days (IQR 94-150), median weight was 5.0 kg (4.2-5.3). None of the patients died within the first 30 postoperative days. In-hospital mortality was 0.5% (1/202 patients). Median follow-up was 57 months (11-121). Overall freedom from reoperation at 5, 10 and 15 years was 91.8%, 86.9% and 86.9%, respectively.

CONCLUSION

AVSD repair with the double-patch technique is a safe and effective procedure with good early postoperative outcomes and low long-term reoperation rates.

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.

Modified single-patch repair for atrioventricular septal defects results in good functional outcomes in the absence of deep ventricular septal defects

OBJECTIVES

We compared 2-patch repair (TP) with modified single-patch repair (MSP) for complete atrioventricular septal defects and evaluated their effect on the left atrioventricular valve (LAVV) competence. We also identified risk factors for unfavorable functional outcomes.

METHODS

This retrospective study included 118 patients with complete atrioventricular septal defects who underwent intracardiac repair from 1998 to 2020 (MSP: 69; TP: 49). The median follow-up period was 10.4 years. The functional outcome of freedom from moderate or greater LAVV regurgitation (LAVVR) was estimated using the Kaplan-Meier method.

RESULTS

The hospital mortality was 1.7% (2/118) and late mortality was 0.8% (1/118). Eight patients required LAVV-related reoperation (MSP: 4; TP: 4) and none required left ventricular outflow tract-related reoperation. In the MSP group without LAVV anomaly, the receiver operating characteristic curve analysis revealed that the ventricular septal defect (VSD) depth was strongly associated with moderate or greater postoperative LAVVR, with the best cutoff at 10.9 mm. When stratified according to the combination of intracardiac repair type and VSD depth, the MSP-deep VSD (VSD depth >11 mm) group showed the worst LAVV competence among the 4 groups (P = .002). According to multivariate analysis, weight <4.0 kg, LAVV anomaly, and moderate or greater preoperative LAVVR were independent risk factors for moderate or greater postoperative LAVVR, whereas MSP was not a risk factor.

CONCLUSIONS

Postoperative LAVVR remains an obstacle to improved functional outcomes. MSP provides LAVV competence similar to TP unless deep VSD is present. The surgical approach should be selected on the basis of anatomical variations, specifically VSD depth.

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.

Long-Term Outcome Up To 40 Years after Single Patch Repair of Complete Atrioventricular Septal Defect in Infancy or Childhood

Objectives  Patients with repaired complete atrioventricular septal defect (CAVSD) represent an increasing portion of grown-ups with congenital heart disease. For repair of CAVSD, the single-patch technique has been employed first. This technique requires division of the bridging leaflets, thus, among other issues, long-term function of the atrioventricular valves is of particular concern.

Methods  Between 1978 and 2001, 100 consecutive patients with isolated CAVSD underwent single-patch repair in our institution. Hospital mortality was 11%. Primary endpoints were clinical status, atrioventricular valve function, and freedom from reoperation in long term. Follow-up was obtained contacting the patient and/or caregiver, and the referring cardiologist.

Results  Eighty-three patients were eligible for long-term follow-up (21.0 ± 8.7, mean ± standard deviation [21.5; 2.1–40.0, median; min–max] years after surgical repair). Actual long-term mortality was 3.4%. Quality of life (QoL; self- or caregiver-reported in patients with Down syndrome) was excellent or good in 81%, mild congestive heart failure was present in 16%, moderate in 3.6% as estimated by New York Heart Association classification. Echocardiography revealed normal systolic left ventricular function in all cases. Regurgitation of the right atrioventricular valve was mild in 48%, mild–moderate in 3.6%, and moderate in 1.2%. The left atrioventricular valve was mildly stenotic in 15% and mild to moderately stenotic in 2%; regurgitation was mild in 54%, mild to moderate in 13%, and moderate in 15% of patients. Freedom from left atrioventricular-valve-related reoperation was 95.3, 92.7, and 89.3% after 5, 10, and 30 years, respectively. Permanent pacemaker therapy, as an immediate result of CAVSD repair ( n  = 7) or as a result of late-onset sick sinus syndrome ( n  = 5), required up to six reoperations in single patients. Freedom from pacemaker-related reoperation was 91.4, 84.4, and 51.5% after 5, 10, and 30 years, respectively.

Conclusion  Up to 40 years after single-patch repair of CAVSD, clinical status and functional results are promising, particularly, in terms of atrioventricular valve function. Permanent pacemaker therapy results in a life-long need for surgical reinterventions.

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 subaortic stenosis resection: 10 years of single-center experience in 65 patients

BACKGROUND

Subaortic stenosis (SAS) was a rare congenital heart disease of left ventricular outflow tract (LVOT), ranging from "isolated" lesions to "tunnel" or "diffuse" lesions. We conducted a retrospective study to describe the characteristics of patients with different lesions and analyze the risk factors for reoperation.

METHODS

In this study, we examined a single-center retrospective cohort of SAS patients undergoing resection from 2010 to 2019. Patients were classified as simple lesion group (n = 37) or complex lesion group (n = 28). Demographics, perioperative findings, and clinical data were analyzed.

RESULTS

The surgical effect of the two groups was significantly lower than that before the operation (p < .05). The median age at operation was 6 (3-11.8) years. There was no operative mortality. In complex lesion group, cardiopulmonary bypass time (CPB time), aortic cross-clamping time (ACC time), mechanical ventilation time, and intensive care unit (ICU) stay time were longer. The median follow-up period was 2.8 years (range: 1-3.8), with two late death. Six patients (9.2%) required reoperation due to restenosis or severe aortic insufficiency. The freedom from reoperation rates at 5 years was 66.7% for simple lesion but only 52.3% for complex lesion (p = .036).

CONCLUSIONS

Although the lesions include many forms, SAS resection was still satisfactory. However, the reoperation after initial surgical treatment was not infrequent, especially in patients with complex lesion.

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.

The Surgeon's View of the Left Ventricular Outflow Tract in Congenital Heart Surgery

Left ventricular outflow tract (LVOT) obstruction is a component of many forms of congenital heart disease, including hypertrophic cardiomyopathy, membranous subaortic stenosis, tunnel subaortic stenosis, and outflow tract obstruction related to atrioventricular septal defects. We have gained a particularly extensive experience with the diagnosis and treatment of hypertrophic cardiomyopathy, having performed septal myectomy in over 3,800 patients. In the setting of this review of LVOT obstruction, we use hypertrophic cardiomyopathy as a template by which other pathologies causing LVOT obstruction can be understood. We review important surgical issues in patient selection, diagnostic evaluation, interpretation of imaging, and operative management. To this end, the review focuses on obstructive hypertrophic cardiomyopathy and then broadens to discuss other pathologies causing LVOT obstruction, with important similarities and differences in their management. These other pathologies share some similar presentations and operative techniques, and at times can be confused with hypertrophic cardiomyopathy, but also have important distinctions of which the surgeon should be aware.

Repair of Partial Atrioventricular Septal Defects in Adults: A Single Center Experience

Limited data are available on long-term outcome after repair of partial atrioventricular septal defects (pAVSD) in adults. We sought to review our experience. Between January 1, 1957 and December 31, 2016, 179 adult patients [median age (IQR) 34 (18, 72) years] underwent primary repair of pAVSD. The most common associated defects were secundum atrial septal defect (n = 38) and ventricular septal defect (VSD) (n = 7). Left atrioventricular valve (LAVV) zone of apposition (ZOA) was complete in 47 patients and LAVV regurgitation (≥moderate) was present in 73 patients. Autologous pericardium (n = 79, 45%) and polytetrafluoroethylene felt (n = 56, 32%) were mainly used for pAVSD closure.  Repair techniques for LAVV regurgitation included: ZOA suture closure (n =  142), suture annuloplasty (n = 10) and posterior band annuloplasty (n = 9). Six had LAVV replacement. There were 61 deaths over a median follow-up of 21 years (IQR 10, 38), with only 4 early deaths. In a limited subset of patients with 80 paired measurements (n = 40), median right ventricular systolic pressure declined from 43 mm Hg (IQR 35-51) to 33 mm Hg (IQR 30-44) postoperatively (P < 0.001), and this improvement was sustained over long-term follow-up (P = 0.513). A total of 34 patients underwent a reoperation (recurrent LAVV regurgitation, n = 26; left ventricular outflow-tract obstruction, n = 7; LAVV stenosis, n = 4; patch dehiscence, n = 1) with cumulative incidence of 6% and 16% at 10 and 15 years, respectively. Repair of pAVSD in adults can be done safely with low early mortality and good long-term outcomes. Postrepair reduction of pulmonary artery pressure is significant. Despite the low re-operation rates, long-term surveillance remains essential.

Perioperative and Anesthetic Considerations in Atrioventricular Septal Defect

Atrioventricular septal defect results from a failure of normal endocardial cushion fusion during embryologic cardiac development. This developmental aberration results in defects in the atrial and/or ventricular septum and malformation of the atrioventricular valves. The pathophysiology of atrioventricular septal defect is variable, and ranges from mild left to right shunting similar to a simple atrial septal defect to complex single-ventricle heart disease. This review focuses on the spectrum of atrioventricular septal defect from partial to complete, without associated cardiac defects.

Repair of Partial Atrioventricular Septal Defect: Age and Outcomes

BACKGROUND

We evaluated the outcomes of patients undergoing surgical repair of partial atrioventricular septal defect (AVSD) and analyzed the effect of age on outcome.

METHODS

In this single-center retrospective study, we included all children who underwent repair of partial AVSD between 1990 and 2014. We divided the patients into 4 age quartiles (first quartile: 0-0.75 years, n = 22; second quartile: 0.75-1.5 years, n = 21; third quartile: 1.5-3.75 years, n = 22; and fourth quartile: >3.75 years, n = 21). These quartiles were evaluated for their association with the time-to-event outcomes of survival, freedom from left atrioventricular valve regurgitation (LAVVR), and freedom from reoperation using log-rank analysis.

RESULTS

During the study period, 86 patients underwent partial AVSD repair at a median age of 1.5 years. There were no operative deaths and 2 late deaths (unknown cause and trauma). There were 13 reoperations. The most common cause of reoperation was left ventricular outflow tract obstruction (LVOTO) (5 patients [first quartile, 2 cases; second quartile, 1 case; third quartile, 2 cases, and fourth quartile, 0 cases]). LAVV reoperation for insufficiency or stenosis was performed in 4 patients (first quartile, 1 case; second quartile, 1 case; third quartile, 1 case; and fourth quartile, 1 case). Two patients underwent pacemaker placement (second quartile, 1 case and fourth quartile, 1 case). There were no statistically significant differences in the most common complications-LVOTO, LAVVR, and AV heart block-between the 4 age quartiles. Median follow-up was 7.1 years (interquartile range [IQR], 0.8-11.4 years). On echocardiography, 72 patients (84%) had less than or equal to mild LAVVR, 8 (9%) patients had mild to moderate LAVVR, 5 (6%) patients had moderate LAVVR, and 1 (1%) patient had severe LAVVR. Age at repair had no significant association with degree of late AV valve insufficiency.

CONCLUSIONS

Results of partial AVSD repair at a median age of 1.5 years are excellent. Operating at this age is not associated with increased mortality, reoperation, or LAVVR.

Subaortic Area at Risk for Development of Obstruction After Surgical Repair of Atrioventricular Septal Defect: Myth or Reality?

BACKGROUND

Morphology of the left ventricular outflow tract (LVOT) in atrioventricular septal defects (AVSDs) has been reported to be at risk for development of obstruction. The purpose of the present study was to identify the incidence, the risk factors, and the surgical outcomes of subaortic stenosis in repaired AVSDs.

METHODS

Records of 427 consecutive patients who underwent anatomical repair for all types of AVSDs from January 2000 to December 2012 were reviewed. Outcomes, independent risk factors, reoperation, and death were analyzed.

RESULTS

In a median follow-up of five years (range: 17 months-11.8 years), eight patients required nine reoperations for subaortic stenosis. Study group (n = 11) included three additional patients for whom repair was performed in a different institution. Median delay for reoperation was 11.9 years (range: 1.3-19.4 years). Surgical relief of subaortic stenosis was obtained by means of the enlargement of the LVOT: resection of fibrous structures in all reoperated patients and associated with septal myectomy in four. Two patients required a modified Konno procedure. Five reoperations were associated with left atrioventricular valve repair or replacement. Statistical analysis didn't reveal any morphologic or demographic risk factors. No early or late death occurred.

CONCLUSION

The development of subaortic stenosis after repair of AVSD remains a rare complication in midterm follow-up (incidence: 1.9%). The performance of preventive gesture during repair seemed to be unjustified. The surgical management of this reoperation consists of a simple and safe procedure.

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.