Percutaneous closure of perimembranous ventricular septal defects utilizing almost ideal Amplatzer Duct Occluder II: Why limitation in sizes?

Assessment of degradability and endothelialization of modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluders over time in vivo

OBJECTIVE

To evaluate the fiber-degradation and endothelialization of a modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluder for a long time in vivo.

METHODS

A total of 57 New Zealand rabbits were selected to establish the vasculature implantation model, which would be used to characterize the mechanical properties and pathological reaction of PLLA filaments (a raw polymer of ASD occluder). In total, 27 Experimental piglets were used to create the ASD model for the catheter implantation of PLLA ASD occluders. Then, X-ray imaging, transthoracic echocardiography, histopathology, and scanning electron microscope (SEM) were performed in the experimental animals at 3, 6, 12, and 24 months after implantation.

RESULTS

In the rabbit models, the fibrocystic grade was 0 and the inflammatory response was grade 2 at 6 months after vasculature implantation of the PLLA filaments. The mass loss of PLLA filaments increased appreciably with the increasing duration of implantation, but their mechanical strength was decreased without broken. In the porcine models, the cardiac gross anatomy showed that all PLLA ASD occluders were stable in the interatrial septum without any vegetation or thrombus formation. At 24 months, the occluders had been embedded into endogenous host tissue nearly. Pathological observations suggested that the occluders degraded gradually without complications at different periods. SEM showed that the occluders were endothelialized completely and essentially became an integral part of the body over time.

CONCLUSION

In the animal model, the modified PLLA ASD occluders exhibited good degradability and endothelialization in this long-term follow-up study.

Comparative outcomes of two competitive devices for retrograde closure of perimembranous ventricular septal defects

Background

Retrograde closure of perimembranous ventricular septal defects (pmVSDs) is a well-established procedure. However, interventionists are still looking for the best closure device.

Methods

We performed a single-center retrospective review of 5-year-experience (from July 2015 to July 2020) with retrograde closure of pmVSDs using AmplatzerTM Duct Occluder II (ADOII) and KONAR-MF™ VSD occluder (MFO). Deficient sub-aortic rim (SAR) (≤2.5 mm for MFO and ≤3 mm for ADOII) was an exclusion criterion in defects with a diameter ratio (right-side exit/left-side entry) > 0.5.

Results

We identified 77 patients (57.1% males) with a median age of 4.3 years (IQR, 2.2-8.3) and a median weight of 16 kg (IQR, 11.2-24.5). 44 (57.1%) defects (22.7% with deficient SARs) with a median left-side defect diameter of 8.7 mm (IQR, 5.7-10) were closed with ADOIIs. 33 (42.9%) defects (51.5% with deficient SARs) with a median left-side defect diameter of 10.8 mm (IQR, 8.8-13.5) were closed with MFOs. One 7/5 MFO was removed before release and upsized to a 12/10 MFO. Implantation success rate was 100% with ADOII and 90.9% with MFO devices. Two MFOs were snare-recaptured after embolization, and one 9/7 MFO was snare-retrieved for a new onset of grade-2 aortic regurgitation that persisted afterward. Median follow-up was 3.3 years (IQR, 2.1-4.2) for ADOII and 2.3 years (IQR, 1.7-2.5) for MFO. No permanent heart block or death occurred. Freedom from left ventricular dilation was 94.62% at 36 months of follow-up. Freedom from residual shunt was 90.62% for MFO and 89.61% for ADOII at 24 months of follow-up. One 2.6-year-old patient with baseline mild aortic valve prolapse and trivial aortic regurgitation developed a grade-2 aortic regurgitation after 9/7 MFO implantation. He was treated surgically after two years without device extraction. One new grade-2 asymptomatic tricuspid regurgitation persisted at the last follow-up in the ADOII group.

Conclusions

ADOII and MFO are complementary devices for effective retrograde closure of pmVSDs in children, including defects with absent or deficient SAR. ADOII is limited to smaller defects but offers a lower profile and a flexible left-side disk for better maneuverability over the aortic valve during retrograde implantation.

Transfemoral Occlusion of Doubly Committed Subarterial Ventricular Septal Defect Using the Amplatzer Duct Occluder-II in Children

Backgrounds

The traditional treatment of doubly committed subarterial ventricular septal defect (dcVSD) is open-heart surgery. This study aimed to evaluate the feasibility, safety, and outcome of transcatheter closure of small dcVSD using Amplatzer duct occluder-II (ADO-II) in children.

Methods

Between January 2016 and April 2021, 24 children (17 male and 7 female patients) with small dcVSD who received transfemoral closure with ADO-II were enrolled retrospectively. All of their available clinical and follow-up data were evaluated.

Results

The patients' median age was 3.2 years (1.6–12.6 years, 4.2 ± 3.1 years) and body weight was 13.3 kg (10.0–38.5 kg, 16.5 ± 7.7 kg). Left ventricular angiography showed that the median dcVSD size was 2.0 mm (1.5–3.5 mm, 2.1 ± 0.6 mm). The device was successfully implanted in 23 patients (95.8%), and one patient failed to be closed because of the underestimation of defect size due to preoperative aortic valve prolapse, with 16 patients by the antegrade approach and eight patients by retrograde approach. The diameters of the device used were 3/4, 4/4, and 5/4 mm. The median operative time was 40.0 min (20.0–75.0 min, 41.7 ± 13.7 min), and the median fluoroscopic time was 5.0 min (3.0–25.0 min, 6.8 ± 5.0 min). With a follow-up duration of 1+ to 45+ months, only 1 patient presented with new-onset mild aortic regurgitation (AR).

Conclusion

Transfemoral closure of small dcVSD with ADO-II is technically feasible and safe in the selected children. However, the development or worsening of AR requires long-term follow-up.

Safety and Efficacy of Transcatheter Occlusion of Perimembranous Ventricular Septal Defect with Aortic Valve Prolapse: A Six-Year Follow-Up Study

Background

With the rapid development of transcatheter techniques and instruments, transcatheter occlusion for patients with perimembranous ventricular septal defect (pVSD) and aortic valve prolapse (AVP) was constantly being tried, while the efficacy and safety of pVSD with AVP remain controversial.

Objective

The aim of this study was to evaluate long-term efficacy and safety of transcatheter occlusion of pVSD with AVP.

Methods

We retrospectively analyzed 164 children with pVSD and AVP who underwent transcatheter occlusion between January 2013 and November 2014. AVP was divided into 3 degrees according to right coronary leaflet morphology at end-diastole during aortic root angiography. Patient demographic and clinical data were collected.

Results

There were 97 males and 67 females (median age, 40.0 (30.0–62.7) months; average weight, 16.94 ± 9.02 kg). Mild (n = 63), moderate (n = 89), and severe (n = 12) AVP success rates were 93.7%, 89.9%, and 58.3%, respectively. Immediately after procedure, there was no new-onset aortic regurgitation (AR) above trivial degree, residual shunt above mild degree, or complications requiring medication or operation, except for 1 patient who developed transient complete atrioventricular block. During follow-up, 1 mild AVP patient aggravated from mild to moderate AR and 1 moderate AVP patient aggravated from trivial to moderate AR. The new-onset AR in mild, moderate, and severe AVP was 2%, 1.8%, and 20%, respectively. AR disappeared in 17 patients. Residual shunt occurred in 9 patients after procedure, 4 of which disappeared during the follow-up period. No serious complications occurred in any patient during follow-up. Five-year cardiovascular event-free survival rates for mild, moderate, and severe AVP were 89.6%, 94.5%, and 80.0%, respectively.

Conclusion

Transcatheter occlusion of pVSD with mild and moderate AVP has a high success rate and few complications, which is safe and effective in long-term follow-up. Transcatheter occlusion of pVSD with severe AVP has low success rates and high AR incidence. Therefore, transcatheter occlusion of pVSD with AVP is recommended for mild to moderate, but not severe, AVP.

Percutaneous Closure of an Iatrogenic Inlet Ventricular Septal Defect in an Atrioventricular Canal

A 45-year-old woman with a partial atrioventricular canal presented with an iatrogenic interventricular shunt after implantation of a mechanical mitral prosthesis. The shunt was occluded percutaneously with an Amplatzer Duct Occluder II. This is the first reported percutaneous closure of a ventricular septal defect in an atrioventricular canal defect. (Level of Difficulty: Intermediate.)

Effect of transcatheter closure by AmplatzerTM Duct Occluder II in patients with small ventricular septal defect

Transcatheter closure of ventricular septal defect (VSD) is an alternative treatment of surgery. However, because of the potential risk of the complete atrioventricular block (AVB) and the lack of available dedicated devices for VSD, this procedure rarely used most centers. Recently in Thailand, with distinct device design that may cause less clamp force and radial force, the Amplatzer^TMDuct Occluder (ADO) II has become available for the closure of small VSDs. This is a retrospective review of 49 patients who underwent transcatheter VSD closure using ADO II at Songklanagarind hospital and Queen Sirikit National Institute of Child Health between January 2014 and December 2016 with an intention to report procedural success rate and 12-months-outcomes. Twenty-six cases were female. The median age and weight at treatment were 7.8 year (ranged from 1.9 to 25 year) and 25.1 kg (ranged from 11 and 57 kg). The majority (65.3%) of the VSD was a perimembranous defect. The mean diameter of LV entry was 5.2 ± 2.5 mm and the mean RV exit was 3.2 ± 0.8 mm. Four patients had more than 1 exit at RV orifice. The mean length of the VSD was 5.3 ± 1.8 mm. The mean aortic valve-VSD distance was 3.9 ± 2.0 mm. The mean tricuspid valve-VSD distance was 3.8 ± 2.5 mm. The procedural success achieved in all patients (100%), most of the implantations were performed in a retrograde approach (53.1%). The ADO II was successfully implanted in 2 cases (5%) who failed other devices in the first attempts. There were no major complications. There were no changes in the severity of tricuspid and aortic valve regurgitation immediate after implantation and at 12 months' follow-up. Three patients (6%) had tiny to small residual shunt at 12 months' follow-up. None of the patients had a complete heart block. However, new-onset of left bundle branch block and right bundle branch block occurred in 2 (5%) cases and 5 (10%) cases, respectively. With symmetrical double-disc design and softness of the device, the ADO II can be safely and effectively used for closure of the VSDs with the defect size less than 6 mm.