Transcatheter Closure of Perimembranous Ventricular Septal Defect Using KONAR-MF™: A Multicenter Experience

Transcatheter closure of perimembranous ventricular septal defect (PmVSD) is an established procedure. However, the occurrence of complete heart block limits its scope. The newer KONAR-MF™ occluder has specific design characteristics that may improve the safety of PmVSD closure. The objective of the study was to describe the efficacy and mid-term follow-up of transcatheter closure of PmVSD using KONAR-MF™. The study was conducted prospectively in 3 Indian centers (January 2018-December 2022). PmVSD closure was done by both antegrade and retrograde methods, and patients were followed up at 1, 3, 6, 12 months, and annually after that. 121 out of 123 patients were included with the following characteristics: median age 4.4 (0.18-40) years; weight 15 (2.1-88) kg; mean Qp/Qs ratio 1.87 ± 0.52 and pulmonary artery mean pressure: 22 ± 6.9 mmHg. The procedure was successful in all but 3; the device was removed due to significant residual shunt (n = 2) and new development of aortic regurgitation (AR) (≥ mild) in 1. The median defect size was 5.2 (2.5-12) mm. Device sizes from 6/4 to 14/12 were deployed (median fluoroscopy time 13.3 min; range 3.6-47.8). Shunt occlusion rates were 90%-Immediate, 95%-pre-discharge, and 97%-1 month, with no instances of complete heart block after the procedure and during follow-up. Six had new onset AR (mild: 2, trivial 4), and one had increased tricuspid regurgitation. All patients were well during follow-up (median: 20 months; range: 6-46). The new KONAR-MF™ occluder appears to be a promising and safe alternative for the closure of the PmVSD; further long-term follow is merited.

Transfemoral Perimembranous Ventricular Septal Defect Device Closure in Infants Weighing ≤ 10 kg

Transcatheter closure of Perimembranous VSDs (PMVSD) remains challenging particularly in infants. The aim of this study is to evaluate the efficacy and safety of transfemoral PMVSD device closure in infants weighing ≤ 10 kg in a single centre. Retrospective review of departmental databases and medical charts to define patient cohort and collect demographic, procedural and follow-up data. Between July 2014 and March 2021, 16 patients underwent attempted transfemoral PMVSD device closure (12 retrograde) at a median age of 11 months (interquartile range [IQR] 9-15.5) and a median weight of 8.3 kg (IQR 7.2-9.5). All patients were either symptomatic, had progressive left heart dilation or had VSD associated valve regurgitation. Median defect size on pre-procedural transoesophageal echocardiography was 6.8 mm (IQR 6-8.5). Median device waist size was 6 mm (IQR 4.5-8). Successful device placement was achieved in 14 patients (88%). One patient developed moderate aortic and tricuspid valve regurgitation upon retrograde and antegrade device deployment, respectively, and subsequently underwent surgical closure. The second patient developed progressive aortic regurgitation (AR) 2 days post procedure, and also underwent surgical removal with no residual AR. There was no cases of device embolization and no femoral arterial compromise. On median follow-up of 40.5 months (IQR 25-64), none of the patients developed complete heart block. Three patients (18.75%) had small residual shunts at latest follow-up which have not required any further intervention. Device closure of PMVSD's in children weighing ≤ 10 kg is feasible and safe with good procedural success rates. Use of both the antegrade and retrograde approaches may be necessary depending on anatomical variances.

First-in-man transradial percutaneous closure of ventricular septal defect with an Amplatzer Duct Occluder IΙ in an adult patient: a case report

Background

Transcatheter closure of perimembranous ventricular septal defect (VSD) is a promising alternative to surgical closure but has been associated with conduction disorders. Vascular access via multiple large vessels is associated with procedure-related complications, undermining the benefit of percutaneous approaches. In this case, we present the first-in-man transcatheter closure of a perimembranous VSD with an Amplatzer Duct Occluder IΙ in an adult patient via a single transradial artery access.

Case summary

A 62-year-old female was admitted to the hospital due to gradually worsening fatigue and shortness of breath on exertion. Transoesophageal echocardiogram (TOE) revealed a VSD size of 4-6 mm and a left ventricular ampulla size of 12 mm. A percutaneous VSD closure with the Amplatzer Duct Occluder II was decided. The angiography and TOE showed successful device placement and excellent procedural results. The patient was discharged home the next day after the procedure. The patient did not report any post-procedural complications during the 8-month follow-up. Echocardiographic assessment showed a gradual decrease in left ventricular dimensions.

Discussion

Transcatheter closure of perimembranous VSD is a promising alternative to surgical closure, but it is not free of complications. Traditional VSD occluders rely on multivessel access and complex formation of arteriovenous loops. In this case, we report the feasibility of perimembranous VSD closure with an Amplatzer Duct Occluder IΙ via a single radial artery access in an adult patient. This approach is a much simpler technique with several potential advantages and should be considered in selected adult patients and in similar clinical scenarios.

Transcatheter closure of large perimembranous ventricular septal defects with inlet to outlet extension with the Amplatzer Vascular Plug-II

Transcatheter closure of perimembranous ventricular septal defect is an alternative to surgery in selected small to medium defects with a reasonable distance between the defect and the aortic or tricuspid valves. Surgical closure is generally preferred for large defects with an inlet to outlet extension, aortic malalignment, or deficient aortic rim. We report two successful cases of percutaneous closure of large perimembranous ventricular septal defects with inlet to outlet extension using an Amplatzer Vascular Plug-II via a retrograde approach. Transcatheter closure of large perimembranous ventricular septal defect with inlet to outlet extension is feasible and facilitated by the characteristics of the Amplatzer Vascular Plug-II device and the specific implantation technique.

Transcatheter Versus Surgical Closure of Acute Ruptured Sinus of Valsalva Aneurysms with Associated Ventricular Septal Defects

Transcatheter ruptured sinus of valsalva aneurysm (RSOVA) closure is an alternative to surgery. When a restrictive ventricular septal defect (rVSD) coexists, there are doubts about support for an occluder and persistent left ventricular (LV) dilatation. We compared the outcomes of patients from a single centre with rVSD and RSOVA after surgery or transcatheter intervention in the past 8 years in this study. Location of rVSD did not alter the approach. Compliant balloon interrogation before transcatheter closure was occasionally used to assess significance of interventricular shunt or aortic regurgitation. Procedural success and LV dimensions before and after treatment were analyzed. Seventeen patients with a mean age of 36.64 ± 12.58 years were analyzed. 12/13 catheter procedures (92%) were successful, of whom eight patients had an outlet VSD. rVSD was closed with device in one patient with perimembranous rVSD, but unaddressed in others. Four patients underwent balloon interrogation. Surgery included the single patient who failed intervention. Transcatheter group had more acute symptoms and advanced functional class than surgical group, though not significant. At a median follow-up of 4.5 (1-7.5) years, the mean LV dimensions (50.3 ± 10.1 mm and 50.1 ± 3.1 mm, p = 0.46) were not different in the transcatheter and surgical groups. Mean end-diastolic volumes (110.5 ± 42. 1 ml and 98.5 ± 37.5 ml, p = 0.91) were not significantly different either. Transcatheter RSOVA closure success was not altered by rVSD despite their location underneath the aneurysms, including outlet rVSD with defect in aortoventricular junction. Persistent LV dilatation was not observed after catheter intervention even when the VSD was not closed.

Mapping the Conduction System in Patients Undergoing Transcatheter Device Closure of Perimembranous Ventricular Septal Defect: A Proof-of-Concept Study

Earlier studies that investigated the relation of atrioventricular (AV) conduction system to perimembranous ventricular septal defect (pmVSD) were based on cardiopathological specimens. To study the relationship of conduction system to pmVSD using 3-dimensional electroanatomic mapping system (EAMS) in patients undergoing device closure. Fifteen consecutive cases of pmVSD from January 2014 to July 2017 (age > 2 years and weight > 8 kg) were included in the study. The course of conduction system and its relationship with the pmVSD was mapped before and after device closure, with the use of EAMS. Median age and weight of the cohort was 10 years (range 4-21 years) and 25 kg (range 13-55) respectively. Device implantation was successful in all patients except 1. The course and relation of the conduction system were posteroinferior to the pmVSD in all cases (100%), and away from the defect in 67% (10/15). In patient with baseline RBBB, the right-sided conduction system was in close proximity to the pmVSD. Two patients had part of left-sided conduction system in close proximity to pmVSD or device edges. Two patients developed RBBB following device deployment, which reverted to normal on follow up. No patient developed high grade AV block during the median follow-up of 34 months (range 24-62). This experimental study has shown the feasibility of 3D EAM of conduction system during device closure of pmVSD. This novel concept can be utilized to understand the anatomy of conduction system in other congenital heart diseases.

Risk factors for atrioventricular block after occlusion for perimembranous ventricular septal defect

BACKGROUND

The risk factors for complete atrioventricular block (CAVB) after device closure of perimembranous ventricular septal defect (pmVSD) remain unclear.

OBJECTIVE

The purpose of this study was to analyze the incidence and risk factors for CAVB after device closure for pmVSD.

METHODS

We reviewed 1884 patients with pmVSD who had undergone successful device occlusion between June 2005 and January 2020. Permanent CAVB was defined as CAVB requiring implantation of a permanent pacemaker (PPM) or extraction of the occluder.

RESULTS

In total, 14 patients (0.7%) developed permanent CAVB. Of these patients, 10 (0.5%) required PPM implantation. Four permanent CAVB occurred within 7 days after the procedure (acute), 2 between 7 and 30 days (subacute), 3 between 30 days and 1 year (late), and 5 more than 1 year (very late). None of the subacute, late, and very late CAVB recovered normal conduction with medication and eventually required device removal or PPM implantation. Four patients with acute CAVB and 1 with subacute CAVB underwent device removal, and 4 (80%) recovered normal conduction. Multivariate regression revealed that the ratio of device to defect size was the only independent risk factor for permanent CAVB (odds ratio 3.027; 95% confidence interval 1.476-6.209; P = .003).

CONCLUSION

The incidences of permanent CAVB after occlusion for pmVSD and PPM implantation were 0.7% and 0.5%, respectively. The ratio of device to defect size was the only independent risk factor for permanent CAVB. Device removal is an effective therapeutic modality for recovering normal conduction in acute and subacute CAVB patients.

Novel Strategy for Predicting Conduction Abnormalities During Transcatheter Closure of Perimembranous Ventricular Septal Defect in Adults

BACKGROUND

In this study we evaluated the feasibility and efficacy of predicting conduction system abnormalities under 3-dimensional (3D) electroanatomic mapping guidance during transcatheter closure of perimembranous ventricular septal defects (pmVSDs) in adults.Methods and Results:The distribution of the His-Purkinje system (HPS) close to the margins of pmVSDs in the left ventricle was identified using 3D electroanatomic mapping and near-field HPS was further confirmed by different pacing protocols. Of the 20 patients in the study, 17 (85%) were successfully treated by transcatheter intervention. The minimum distance between the margins of the pmVSD and near-field HPS, as measured by 3D electroanatomic mapping, ranged from 1.3 to 3.9 mm (mean [± SD] 2.5±0.7 mm). Five patients with a minimum distance <2 mm had a higher risk (3/5; 60%) for adverse arrhythmic events, whereas patients with a distance >2 mm were at a much lower risk (1/15; 6.7%) of procedure-related conduction block (P=0.032). No other adverse events were recorded during the follow-up period (median 30 months).

CONCLUSIONS

A minimum distance between the pmVSD and near-field HPS <2 mm was associated with a relatively high risk of closure-related conduction block. 3D electroanatomic mapping may be helpful in guiding decision making for transcatheter closure and reduce the incidence of adverse arrhythmic events.

Comparison of transcatheter versus surgical closure of perimembranous ventricular septal defect in pediatric patients: A systematic review and meta-analysis

OBJECTIVE

Perimembranous ventricular septal defect (pmVSD) is a common congenital heart disease (CHD) usually treated with either catheter or surgical closure. Superiority of one procedure over the other in children is still a matter of debate. We performed this meta-analysis to compare the clinical outcomes and cost of transcatheter and surgical closure of pmVSD in children.

MATERIALS AND METHODS

We searched seven databases (MEDLINE, PubMed, EMBASE, Google Scholar, CENTRAL, CINHAL, and Cochrane library) and literature references for articles published in the past 10 years (between January 2008 and January 2018) comparing closure of pmVSD by both procedures in children. The outcomes of interest were success rate, residual shunt, need for blood transfusion, complications especially complete atrioventricular block, length of hospital stay, and cost.

RESULTS

A total of 1750 articles were identified. However, only five studies fulfilled the inclusion criteria. As regards success rate, no significant difference was found between surgical and catheter closure. Residual shunt was significantly lower in catheter closure than surgical closure [risk ratio (RR) = 0.44; 95% confidence interval (CI), 0.23-0.83, p = 0.01). The need for blood transfusion and the length of hospital stay were significantly lower in the catheter closure compared to surgical closure (RR = 0.02; 95% CI, 0.01-0.08; p < 0.00001), (RR = -4.81; 95% CI, -7.76 to -1.86; p = 0.001), respectively. However, overall complications, complete atrioventricular block, and the cost were comparable in both procedures.

CONCLUSION

Transcatheter closure of pmVSD in children was as effective as surgical closure with a lower residual shunt and need for blood transfusion, and shorter hospital stay.

Echocardiography-guided percutaneous closure of perimembranous ventricular septal defects without arterial access and fluoroscopy

Background

Traditional percutaneous device closure of perimembranous ventricular septal defects (PmVSDs) is a minimally invasive technique, but can result in high radiation exposure and can result in potential arterial complications. Here, we aimed to assess the safety and feasibility of device closure of PmVSDs via the femoral vein approach under transesophageal echocardiography (TEE) guidance in children.

Methods

From January 2014 to December 2017, a total of 46 PmVSD patients (mean age, 6.5 ± 2.3 years [range, 4.2–12.0 years]; mean body weight 22.1 ± 6.6 kg [range, 16.0–38.5 kg]; VSD diameter, 4.1 ± 0.6 mm [range, 3.2–5.0 mm]) underwent attempted transcatheter closure via the femoral vein approach under the guidance of TEE without fluoroscopy.

Results

The transcatheter occlusion procedure under TEE guidance was successful in 44 (95.7%) patients. Surgery was necessary in 2 (4.3%) patients. The procedure duration was 28.2 ± 8.7 min (range, 12.0–42.0 min). One patient had immediate post-operative trivial residual shunt and three patients had immediate incomplete right bundle branch block (IRBBB) after operation; the new IRBBB in 1 case was noted in the first postoperative month. No residual shunt was noted at 3 months after the procedure, and no intervention related complications were detected at 1–24 months follow-up.

Conclusions

Percutaneous device closure of PmVSDs under TEE guidance solely by femoral vein approach is effective and safe, avoids radiation exposure, potential arterial complications and a surgical incision.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1687-0) contains supplementary material, which is available to authorized users.

A meta-analysis of perventricular device closure of perimembranous ventricular septal defect

Background

To investigate the safety and efficacy of perventricular device closure of perimembranous VSD (pmVSD).

Methods

PubMed and Scopus were searched for studies in English focusing on perventricular device closure of pmVSD published up to the end of March 2019. We used a random-effects model to obtain pooled estimates of the success and complication rates.

Results

A total of 15 publications comprising 1368 patients with pmVSD were included. The median follow-up duration was 2 months to 5 years, with a mean patient age ranging from 2 months to 56 years. The pooled success rate was 0.95 (I² = 86.2%, P = 0.000). The pooled rate of postoperative residual shunting was 0.02 (95% CI: 0.01–0.03, I² = 87.3%, P < 0.001). The pooled rate of residual shunting in the follow-up period was 0.001 (95% CI:-0.001–0.002, I² = 30.5%, P = 0.126). The pooled estimated rate of severe complications was 0.074 (95% CI: 0.046–0.102, I² = 30.5%, P = 0.126). The pooled incidence of complete atrioventricular block (cAVB) was 0.002 (95% CI: 0.000–0.005, I² = 0.0%, P = 0.577).

Conclusions

Perventricular device closure may be an alternative to conventional surgical repair in selected patients with pmVSD. The success rate was stable regarding the publication year and sample size and suggested both the short learning curve of this technology and its potential for wide application. The incidence of severe arrhythmia, especially cAVB, was low. These good results may be limited by the number of enrolled patients, and a more detailed and larger sample is required for further analysis.

Assessing the criteria for definition of perimembranous ventricular septal defects in light of the search for consensus

Background

Discussions continue as to whether ventricular septal defects are best categorized according to their right ventricular geography or their borders. This is especially true when considering the perimembranous defect. Our aim, therefore, was to establish the phenotypic feature of the perimembranous defect, and to establish the ease of distinguishing its geographical variants.

Methods and results

We assessed unrepaired isolated perimembranous ventricular defects from six historic archives, subcategorizing them using the ICD-11 coding system. We identified 365 defects, of which 94 (26%) were deemed to open centrally, 168 (46%) to open to the outlet, and 84 (23%) to the inlet of the right ventricle, with 19 (5%) being confluent. In all hearts, the unifying phenotypic feature was fibrous continuity between the leaflets of the mitral and tricuspid valves. This was often directly between the valves, but in all instances incorporated continuity through the atrioventricular portion of the membranous septum. In contrast, we observed fibrous continuity between the leaflets of the tricuspid and aortic valves in only 298 (82%) of the specimens. When found, discontinuity most commonly was seen in the outlet and central defects. There were no discrepancies between evaluators in distinguishing the borders, but there was occasional disagreement in determining the right ventricular geography of the defect.

Conclusions

The unifying feature of perimembranous defects, rather than being aortic-to-tricuspid valvar fibrous continuity, is fibrous continuity between the leaflets of the atrioventricular valves. While right ventricular geography is important in classification, it is the borders which are more objectively defined.

Fetal regional myocardial strain rate in the membranous ventricular septum: changes with gestational age and the left ventricular mass and predictive value for a complete membranous ventricular septum (without defect)

To describe the fetal regional myocardial strain rate in the membranous ventricular septum across gestation and to determine their predictive value for a complete membranous ventricular septum (without defect) after delivery. In 1150 fetuses, the peak systolic strain rate (SRs), peak early diastolic strain rate (SRe) and peak late diastolic strain rate (SRa) in the membranous ventricular septum were measured at four time points across gestation (18-20, 24-26, 30-32 and 36-38 weeks). The integrity of the interventricular septum was examined at 12 weeks' postnatal age. The correlations between myocardial strain rates and gestational age as well as fetal left ventricular mass were analyzed, and the performance of myocardial strain rates in predicting a complete membranous ventricular septum was deducted. Strain rate absolute values in the membranous ventricular septum all increased across gestation. They all significantly correlated with gestational age and left ventricular mass. At 24 weeks during pregnancy, the areas under the receiver operating characteristics curve (AUC) for SRe and SRa were all > 0.72 (p < 0.05) in predicting a complete membranous ventricular septum, while the AUC for SRs was only 0.55. The sensitivity, specificity and accuracy of the cut off value (> 1.53 s^-1) for SRe was 62.5, 85.7 and 73.3%, respectively, and the sensitivity, specificity and accuracy of the cut off value (> 1.51 s^-1) for SRa was 75.2, 71.9 and 73.8%, respectively. The changes of myocardial strain rates in the membranous ventricular septum across gestation maybe can be used to predict a complete membranous ventricular septum after delivery.

Perventricular double-device closure of wide-spaced multi-hole perimembranous ventricular septal defect

Background

Device closure of a wide-spaced multi-hole PmVSD is difficult to succeed in percutaneous approach. This study is to evaluate the feasibility, safety and efficacy of perventricular device closure of wide-spaced multi-hole PmVSD using a double-device implanting technique.

Methods

Sixteen patients with wide-spaced multi-hole PmVSD underwent perventricular closure with two devices through an inferior median sternotomy approach under transesophageal echocardiographic guidance. The largest hole and its adjacent small holes were occluded with an optimal-sized device. The far-away residual hole was occluded with the other device using a probe-assisted delivery system. All patients were followed up for a period of 1 to 4 years to determine the residual shunt, atrioventricular block and the adjacent valvular function.

Results

The number of the holes of the PmVSD was 2 to 4. The maximum distance between the holes was 5.0 to 10.0 mm (median, 6.4 mm). The diameter of the largest hole was 2.5 to 7.0 mm (median, 3.6 mm). The success rate of double-device closure was 100%. Immediate residual shunts were found in 6 patients (38%), and incomplete right bundle branch block at discharge occurred in 3 cases (19%). Both complications decreased to 6% at 1-year follow-up. Neither of them had a severe device-related complication.

Conclusions

Perventricular closure of a wide-spaced multi-hole PmVSD using a double-device implanting technique is feasible, safe, and efficacious. In multi-hole PmVSDs with the distance between the holes of more than 5 mm, double-device implantation may achieve a complete occlusion.

Incidental Ventricular Septal Defect (VSD) in the Donor of a Live Donor Liver Transplant: Tackle and Proceed

Live Donor Liver Transplantation (LDLT) is an act of selflessness on the part of the donor who is subjected to a major hepatectomy. Ensuring safety and long-term well being of the donor is of utmost priority. We describe a 21-year-old otherwise healthy donor with perimembranous Ventricular Septal Defect (VSD) who successfully underwent donor hepatectomy after closure of the VSD. There is no literature available to guide regarding course of action in such a condition neither any study to substantiate the risk involved. Optimum anticoagulation, endocarditis prophylaxis and optimum interval between the two procedures are areas to be defined as our experience with similar cases increases. Our case emphasizes the importance of multidisciplinary approach and management of such patient at high volume centers.

Transcatheter Closure of Perimembranous Ventricular Septal Defects with Left Ventricular to Right Atrial Shunt

During the development of so-called aneurysmal transformation of perimembranous ventricular septal defects (pmVSD), tricuspid valve (TV) morphology and function may be altered resulting in left ventricular (LV) to right atrial (RA) shunting. The feasibility and outcome of interventional closure of these pmVSD has not been investigated so far. Interventional closure of pmVSD associated with mild to moderate LV-to-RA shunt was performed in four patients (aged 6.5-12.5 years). pmVSD were closed under fluoroscopic guidance by establishing an arteriovenous wire loop via a femoral artery and advancing the delivery sheath from a femoral vein. Before device release (or withdrawal if necessary), residual shunting across the device and TV valve function was investigated by transthoracic echocardiography and LV angiography. pmVSD sizes of 4, 5.5, 8 and 8.5 mm were closed with a 4/4 and 6/6 Amplatzer duct occluder II and an 8- and 10-mm Amplatzer muscular VSD occluder device, respectively. There were no or only minor residual postinterventional LV-to-RA shunts. No atrioventricular blocks were observed during a mean follow-up of 12.5 months (range 6.5-17 months). Transthoracic echocardiography indicated that the elimination of the VSD jet pushing the antero-superior TV leaflet open is the key mechanism for LV-to-RA shunt reduction after transcatheter pmVSD closure. Interventional closure in pmVSD associated with mild to moderate indirect LV-to-RA shunting is feasible and results in significant reduction in or elimination of LV-to-RA shunting.

Complete atrioventricular block after percutaneous device closure of perimembranous ventricular septal defect: A single-center experience on 1046 cases

BACKGROUND

Complete atrioventricular block (cAVB) has been deemed a rare complication after transcatheter closure for ventricular septal defect (VSD). However, this serious event appears to be underrecognized and is worth being investigated further.

OBJECTIVES

To determine the incidence and predisposing factors of cAVB associated with closure of VSD using a modified double-disk occluder (MDO).

METHODS

From December 21, 2001 to December 31, 2014, 1046 patients with perimembranous ventricular septal defect underwent percutaneous closure using the MDO. Electrocardiography was evaluated before the procedure, within 1 week after the procedure, and then at 1, 3, 6, and 12 months and every year thereafter. Other baseline and procedural parameters were also evaluated and a comparison between patients requiring pacemakers and those not suffering from cAVB was done.

RESULTS

cAVB occurred in 17 patients (1.63%) after the procedure. Of the 17 patients, 8 underwent permanent pacemaker (PPM) implantation. The cAVB occurred within 30 days after the procedure in 14 patients and after 1 year in 3 patients. In comparison patients aged ≤18 years, patients aged >18 years were more prone to cAVB (P = .025). Logistic regression revealed no significant parameter to predict later requirement for PPM.

CONCLUSIONS

The incidence of cAVB after transcatheter closure of VSD was acceptable, as part of the cAVB population recovered after administration of corticosteroid and application of a temporary pacemaker. Late cAVB (>1 year) appears to make it more difficult to restore normal conduction block. Because of the recurrence of cAVB, life-long follow-up with periodic electrocardiography examination may be mandatory.

Exercises in anatomy: holes between the ventricles

Holes between the ventricles are the commonest congenital cardiac malformations. As yet, however, there is no consensus as to how they can best be described and categorized. In this, our third exercise in cardiac anatomy, we address the issue of classification of ventricular septal defects. We begin our demonstration by analysing the normal heart. We show that the larger part of the ventricular septum is made up of its muscular component. The membranous part accounts for only a small portion, which is located centrally within the cardiac base. This small membranous part forms a boundary between the right-sided chambers and the aortic root. Holes at this site, therefore, which account for the commonest defects closed surgically, will open centrally in the cardiac base, being located postero-inferiorly relative to the supraventricular crest. We then show that the larger part of the crest itself is a free-standing muscular sleeve, which lifts the leaflets of the pulmonary valve away from the cardiac base. Only a very small part of the muscle forming the right ventricular outlet is located in the septal position. Turning our attention to malformed hearts, we show how holes between the ventricles can open centrally at the cardiac base, open to the inlet or outlet of the right ventricle or open within the substance of the apical muscular septum. We demonstrate, however, that description of such geographical location of the defects does not paint the full picture, since lesions with markedly different phenotypic features can open in comparable geographic locations. We illustrate how it is the phenotypic features, as seen from the right ventricle, which convey the crucial information for the surgeon with regard to the location of the atrioventricular conduction axis, using hearts with holes opening to the inlet of the right ventricle with muscular as opposed to partially fibrous borders to emphasize this point. We continue by showing how holes with different phenotypes can also open to the outlet of the right ventricle, the key feature in this regard being malalignment between the apical muscular septum relative to the muscular outlet septum or its fibrous remnant. Malalignment can also be found between the apical ventricular septum and the atrial septum, this being shown in a defect opening to the inlet of the right ventricle. We conclude by emphasizing that, so as to bring together all the information of surgical significance, it is necessary to take note of the geographical location of holes between the ventricles, their phenotypic features and the presence or absence of malalignment between the septal components.

Closure of a large perimembranous ventricular septal defect in a 4.8 kg baby with Down syndrome using a duct occluder

A 9.5-month-old boy with Down syndrome, weighing 4.8 kg, presented with history of failure to thrive. Clinically, he had symptoms and signs of congestive heart failure. His echocardiogram showed a large perimembranous ventricular septal defect (pmVSD) with some inlet extension covered by a large aneurysmal tissue with multiple right ventricular (RV) exits. Additionally, he had hypothyroidism and Hirschsprung disease. Instead of closing the VSD surgically, the VSD was successfully closed utilizing an 8 × 6 mm duct occluder. The baby remained in the intensive care unit for one night. The day after the procedure, the infant was stable and showed clinical improvement. Electrocardiogram (ECG) showed normal sinus rhythm with no evidence of heart block. Twenty-four hours later, echocardiography showed the device was in an excellent position, with a small residual leak. There was normal tricuspid valve inflow and normal aortic valve outflow with no significant valvar insufficiency. The baby was discharged after 3 days in stable condition. We believe infants with such co-morbidities which might complicate their post-operative course and prolong the intensive care unit admission, might benefit from such alternative management.

Percutaneous Closure of Perimembranous Ventricular Septal Defect with Amplatzer Device

BACKGROUND

The Amplatzer perimembranous ventricular septal occluder is an innovative device for percutaneous closure of perimembranous ventricular septal defects (PMVSD). In appropriately selected cases this procedure is safe and effective.

METHODS

Fourteen patients with the mean age 10.53 years (range 18 months to 55 years) and mean body weight 20.64 kg (range 6 to 52 kg) underwent PMVSD closure.

RESULT

The PMVSD mean diameter was 5.28 mm (range from 4 to 9 mm). Implantation was successful in 92% of the cases and all patients had complete occlusion of the shunt within three months.

CONCLUSION

Device orientation was excellent in all cases. Device-related aortic insufficiency, tricuspid insufficiency or left ventricular dysfunction was not observed. One patient had embolisation of the device and another had complete heart block which required a permanent pacemaker implantation. The excellent short term results need to be confirmed over long-term follow-up.