Novel use of Konar-multifunctional occluder

Transcatheter Ventricular Septal Defect Closure with Lifetech™ Konar-MF Occluder in Infants Under 10 kg with Only Using Venous Access

Transcatheter closure of VSD remains a complex procedure in infants with technical challenges and carries the risk of significant complications, due to its complex anatomical morphology and closed proximity to the atrioventricular valves and the conduction system. In this article, we presented transcatheter VSD closure in infants under 10 kg using the Lifetech Konar-MF device via only venous route without TEE guidance and arterial access. Between January 2021 and May 2023, a total of 34 patients weighing less than 10 kg who underwent transcatheter VSD closure antegradely with Lifetech™ Konar-Multifunctional (MF) occluder were included in the study. The mean age of the patients was 8.1 (3.5-35) months. Average weight was 6.5 kg (range 4.5-10 kg). VSD was perimembranous in 27 patients (79.4%). Successful device placement was achieved in all 34 patients. However, device embolization occurred in three patients. One of the patients was successfully implanted with a one size larger device, the surgical closure was performed other two cases. TR occurred in seven patients (20.6%) after releasing devices. None of the patients developed complete heart block. Right bundle branch block developed in two patients. Residual shunt was observed in 9 patients (six small, two moderate, and one large). During follow-up, residual shunt disappeared in six of these patients and only mild residual shunt remained in the other four patients which have not required any further intervention. Transcatheter closure of VSD with Lifetech Konar-MF device is safe and effective in infants less than 10 kg via only venous access with a high success rate and low complication rate. In these patients, transcatheter VSD closure can be performed by excluding the risk of complications that may occur due to AV loop formation, arterial intervention, endotracheal intubation and TEE use.

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.