A comparison of intracardiac echocardiography and transesophageal echocardiography for guiding device closure of ostium secundum atrial septal defect: A 15-year experience.

BACKGROUND AND AIM: Our aim was to evaluate the fluoroscopy time (FT), procedure time (PT) safety and efficacy when using intracardiac echocardiography (ICE) in comparison to transesophageal echocardiography (TEE) guidance for transcatheter closure of Ostium Secundum Atrial Septal Defect (OS-ASD). METHOD: Ninety patients (n = 90) diagnosed with OS-ASD underwent transcatheter closure between March 2006 and October 2021. Fifty-seven patients were treated under ICE guidance, while 33 patients were treated under TEE guidance. RESULTS: Mean age was 43 ± 15 years and 42 ± 10 years in the ICE and TEE groups, respectively. The majority of patients had a centrally placed defect. Median FT was 8.40 min versus 11.70 min (p < .001) in the ICE group compared to the TEE group, respectively. Median PT was 43 min versus 94 min (p < .001) in the ICE group compared to the TEE group, respectively. Both ICE and TEE provided high quality images. All interventions were completed successfully, except for one patient in the ICE group who experienced a device migration, the development of atrial tachycardia in one patient and atrial fibrillation in two patients in the ICE group which spontaneously cardioverted. There were no other complications. CONCLUSION: This study on a consistent cohort of patients with OS-ASD undergoing percutaneous closure suggests that use of ICE is safe and efficacious. Compared to TEE, ICE demonstrated significantly shorter FT and PT, decreasing the entire duration of the procedure and x-ray exposure. No relevant differences were observed in terms of success rate and complications.

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.

Update on Percutaneous Treatment for HFrEF: A Great Armamentarium for a Poor Ventricular Function.

Pharmacological treatment is the cornerstone therapy of heart failure with reduced ejection fraction (HFrEF). In addition, several percutaneous techniques have been developed to treat symptomatic patients, with specific heart failure (HF) phenotypes (e.g., valvular heart disease) that require non-pharmacological treatment. Given their prognostic relevance, it is imperative to deliver high-level patient care. This review provides a clinical overview on the available data regarding transcatheter devices in the armamentarium of contemporary interventional cardiologists, focusing on the clinical and anatomical selection criteria.

Temporary atrial septal defect balloon occlusion test as a must in the elderly.

BACKGROUND: Atrial septal defect (ASD) can often remain asymptomatic until adulthood. It still remains unclear whether large ASD closure in senior people should be performed or not. Temporary ASD balloon occlusion test has been suggested as a tool to assess the risk of acute left ventricular heart failure post-ASD closure, and it allows to better distinguish responders from non-responders. CASE PRESENTATION: An 83-year-old man with a long-standing uncorrected secundum ASD was admitted for recently decompensated right-sided heart failure. During hospitalization, this patient was studied with trans-esophageal echocardiography, cardiac magnetic resonance imaging, and right heart catheterization, showing high Qp:Qs ratio and favorable anatomical conditions for percutaneous closure. Because of patient's increasing need for intravenous diuretics and worsening renal function, it was considered that transcatheter ASD closure could improve symptoms, hence it was performed an attempt of percutaneous closure of the ASD with a fenestrated device. Unfortunately, irrespective of ASD being hemodynamically significant, it was found a very significant increase in pulmonary capillary wedge pressure during the temporary balloon occlusion test, supporting the existence of concealed left ventricular diastolic dysfunction. As a result, it was decided to abandon the procedure and not to close the ASD. CONCLUSION: This clinical case illustrates the value of temporary balloon occlusion test before permanent percutaneous closure of ASD in elderly patients, regardless of left ventricular (systolic or diastolic) dysfunction.

Transcatheter Closure of a Coronary Artery Fistula in a Neonate with Tetralogy of Fallot.

Coronary artery-to-pulmonary artery fistulae are a not uncommon finding in patients with Tetralogy of Fallot (TOF) and collateral-dependent pulmonary blood flow. Management for these fistulae is often primary surgical ligation or unifocalization at the time of complete repair, dependent on the presence of dual blood flow to the involved areas. We present the case of a 32-week premature boy weighing 1.79 kg with TOF, confluent branch pulmonary arteries, major aortopulmonary collaterals, and right coronary artery to main pulmonary artery fistula. The patient demonstrated evidence of coronary steal into the pulmonary vasculature with an elevation in the troponin level without hemodynamic instability, and subsequently underwent successful transcatheter occlusion of the fistula via right common carotid access using a Medtronic 3Q microvascular plug. This case demonstrates the realistic potential for early coronary steal in this physiology and possibility of transcatheter therapy even in a small neonate.

Late systemic desaturation after transcatheter device closure of atrial septal defect.

Transcatheter device closure has emerged as the preferred treatment for ostium secundum atrial septal defects with adequate margins, occasionally requiring surgical intervention to manage complications. We report a case of a young female patient who presented with systemic desaturation and exertional dyspnoea 5 years after device closure. Evaluation demonstrated anterior malposition of the septal occluder, with the right atrial rim of the device diverting the blood from the inferior vena cava to the left atrium. She underwent surgical extraction of the device and pericardial patch closure of the atrial septal defect.

Percutaneous device closure of hemodynamically significant coronary fistula following endomyocardial biopsy in a pediatric heart transplant patient.

Coronary artery fistula is a rare but well-documented complication of right ventricular endomyocardial biopsy, particularly in the adult population. Typically, these fistulae never reach clinical or hemodynamic significance, but some may cause coronary steal and ventricular dysfunction. We report a case of a significant coronary artery fistula requiring device closure in the cardiac catheterization laboratory with subsequent improvement of clinical symptoms and cardiac function.

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.

The role of device closure of patent foramen ovale in patients with cryptogenic stroke.

One of the most frequent causes of cardiac embolism in cryptogenic stroke is a paradoxical embolus, which originate from systemic venous source though an unidentified patent foramen ovale (PFO). PFO is a common finding in the general population with a prevalence of 25% to 30%. Transcatheter PFO device closure is known to be feasible and safety treatment for such patients. In recent years, several randomized controlled trials (RCTs) have been conducted to address the superiority of PFO closure over medical therapy alone in the prevention of stroke recurrence in patients with PFO. In contrast to findings from early 3 RCTs, recent 4 RCTs could successfully show the benefits of PFO device closure compared with medical therapy, with less peri- and postprocedural complication. Based on these data, PFO device closure is recommended to carefully select cryptogenic stroke patients aged from 18 to 65 years, with a high probability of a causal role of the PFO in stroke events. However, it is still uncertain whether PFO closure is superior to oral anticoagulants therapy in these patients. Therefore, further prospective randomized trials are needed to address the efficacy of PFO device closure to oral anticoagulants therapy.

Reference value of perimeter-derived diameter assessed by three-dimensional transesophageal echocardiography in left atrial appendage occluder size selection.

BACKGROUND: The aim of this study was to investigate the utility of perimeter-derived diameter (PDD) measured by three-dimensional (3D) transesophageal echocardiography (TEE) in predicting the size of left atrial appendage (LAA) occluder. METHODS AND RESULTS: Left atrial appendage landing zone diameter (LZD) was measured by two-dimensional (2D) TEE, 3DTEE, and digital subtraction angiography (DSA) as LZD-2Dmax, LZD-2Dmean, LZD-3Dmax, LZD-3Dmean, LZD-PDD, LZD-DSAmax, respectively, before and during transcatheter LAA closure with Watchman devices in 100 patients. A difference of one or more device size intervals between the predicted size and the size actually implanted was defined as mismatching. Seventy-eight patients were followed up by TEE to obtain occluder compression ratio. The correlation between LZD and the final implanted occluder size was 0.559, 0.641, 0.754, 0.760, 0.782, and 0.848 for LZD-2Dmax, LZD-2Dmean, LZD-3Dmax, LZD-3Dmean, LZD-PDD and LZD-DSAmax, respectively (P < .001). Matching ratio between the size predicted by retrospective measurements of LZD and the device size actually implanted was 65%, 57%, 66%, 63%, 70%, and 83% for LZD-2Dmax, LZD-2Dmean, LZD-3Dmax, LZD-3Dmean, LZD-PDD and LZD-DSAmax, respectively. There was no significant difference in LZD value, matching ratio, and compression ratio between the patients with eccentric and noneccentric LAA landing zone (P > .05). Compression ratio of the mismatching subjects was higher than that in the matching subjects when evaluated by LZD-2Dmean, LZD-3Dmean, and LZD-PDD (P < .05). CONCLUSIONS: Landing zone diameter derived from LAA perimeter measured by preprocedure 3DTEE showed reference value for LAA occluder size selection, providing superior correlation and matching ratio with the final implanted size and indicating the adjustment of oversizing.

Comparisons of perventricular device closure, conventional surgical repair, and transcatheter device closure in patients with perimembranous ventricular septal defects: a network meta-analysis.

BACKGROUND: Treatments for perimembranous ventricular septal defects (pmVSD) mainly include conventional surgical repair (CSR), transcatheter device closure (TDC), and perventricular device closure (PDC). We aimed to perform a network meta-analysis to compare the three approaches in patients with pmVSD. METHODS: We searched for comparative studies on device closure and conventional repair for pmVSD to April 2020. A network meta-analysis was performed under the frequentist frame with risk ratio and 95% confidence interval. The main outcome was the procedural success rate. Additional outcomes were postoperative complications, including residual shunt, intra-cardiac conduction block, valvular insufficiency, incision infection, and pericardial effusion. RESULTS: Twenty-four studies of 8113 patients were included in the comparisons. The pooled estimates of success rate favored the CSR compared with the PDC. No significant differences of success rate were found in the TDC versus CSR and the PDC versus TDC. The pooled estimates of incidences of the residual shunt, new tricuspid regurgitation, incision infection, and pericardial effusion favored the PDC compared with the CSR. There were no significant differences between the PDC and TDC approaches in all outcomes except new aortic regurgitation. CONCLUSION: The PDC technique not only reduces the risk of significant complications compared with the CSR, but also produces not inferior results compared with the TDC in selected pmVSD patients. PROSPERO REGISTRATION NUMBER: CRD42019125257.

Mitral Valve Surgery for Congestive Heart Failure.

Mitral valve diseases are common causes of congestive heart failure. Chronic primary and secondary (functional) mitral valve regurgitation are the most common reasons. Valve repair for primary mitral regurgitation cures mitral valve disease, whereas in functional regurgitation, mitral valve repair is associated with high failure rates secondary to persistent/progressive ventricular dysfunction and remodeling. Most patients are managed with strict adherence to the valve guidelines. Mitral valve replacement has an increased role in management of functional mitral regurgitation. Surgery for mitral valve disease is indicated in symptomatic patients with severe valve disease and in asymptotic before irreversible ventricular damage occurs.

Morphologic characterization of the patent ductus arteriosus in the premature infant and the choice of transcatheter occlusion device.

OBJECTIVES: The aim of this study was to describe and differentiate the morphology of patent ductus arteriosus (PDA) seen in children born prematurely from other PDA types. BACKGROUND: PDAs are currently classified as types A-E using the Krichenko's classification. Children born prematurely with a PDA morphology that did not fit this classification were described as Type F PDA. METHODS: A review of 100 consecutive children who underwent transcatheter device closure of PDA was performed. The diameter and length (L) of the PDA and the device diameter (D) were indexed to the descending aorta (DA) diameter. RESULTS: Comparison of 26 Type F PDAs was performed against, 29 Type A, 7 Type C and 32 Type E PDAs. Children with Type F PDAs (median 27.5 weeks gestation) were younger during the device occlusion compared with types A, C, and E (median age: 6 vs. 32, 11, and 42 months; P = 0.002). Type F PDAs were longer and larger, requiring a relatively large device for occlusion than types A, C, and E (Mean L/DA: 1.88 vs. 0.9, 1.21, and 0.89, P ≤ 0.01 and Mean D/DA: 1.04 vs. 0.46, 0.87, and 0.34, P ≤0.01). The Amplatzer vascular plug-II (AVP-II) was preferred for occlusion of Type F PDAs (85%; P <0.001). CONCLUSIONS: Children born prematurely have relatively larger and longer PDAs. These "fetal type PDAs" are best classified separately. We propose to classify them as Type F PDAs to add to types A-E currently in use. The AVP-II was effective in occluding Type F PDAs.

Transcatheter closure of perimembranous ventricular septal defects with the Amplatzer Vascular Plug-II.

OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of the Amplatzer Vascular Plug-II used for the closure of perimembranous ventricular septal defects. BACKGROUND: There are no FDA-approved transcatheter devices for the closure of perimembranous ventricular septal defects. Several studies have reported on the use of various devices either off-label or under clinical trial protocols. However these reports have described significant adverse events including residual shunts, complete heart block, arrhythmia, and new valve regurgitations. Thus far, no study on the Amplatzer Vascular Plug-II has been reported. METHODS: We conducted a 4-year retrospective chart review from August, 2010 to August, 2014, of patients with perimembranous ventricular septal defects associated with ventricular septal aneurysm who underwent transcatheter closure using the Amplatzer Vascular Plug-II. RESULTS: A total of 16 patients underwent Amplatzer Vascular Plug-II transcatheter closure of their perimembranous ventricular septal defects. The median age was 2.56 years (range: 0.5-27.3). Their median weight was 13.0 kg (range: 6.9-71.6). The left ventricular median defect size was 9.3 mm (range: 5.9-14.4). The right ventricular median defect size was 3.6 mm (range: 2.3-5.8). All the patients underwent successful device implantation with 83% of the patients having complete echocardiographic closure at the 1-year follow-up; however, one procedure was complicated by early device embolisation. The device was successfully retrieved and replaced with a larger device. There were no device-related outflow tract obstructions, rhythm abnormalities, or haemolysis. CONCLUSION: Application of the Amplatzer Vascular Plug-II for closure of perimembranous ventricular septal defects appears to be a safe and effective treatment option. Prospective clinical trials and longer follow-up periods are warranted.

Original Article--Clinical and Procedural Characteristics of Successful Transcatheter Device Closure of Ostium Secundum Atrial Septal Defect in Symptomatic Children Weighing <15 kg: A Retrospective Study Spanning One Decade From South India.

Objectives: This retrospective study sought to determine the feasibility of transcatheter atrial septal defect device closure in patients less than 15 kg, as well as to assess complication rates and the reasons for unsuccessful device closure. Background: In general, the risks associated with transcatheter atrial septal defect device closure are believed and reported to be relatively low, but the evidence stems from trials involving adults and older children. Current guidelines do not recommend atrial defect closure in device closure in children <15 kg, due to limited data available for feasibility and safety of device closure in this group of patients. Methods: Retrospective review of all patients who underwent elective transcatheter closure of ostium secundum atrial septal defect between September 2013 to February 2022. We excluded all children above 15 kg, as well as those with complex congenital heart defects. Major and minor complications were predefined and indications for referral were evaluated. Results: We identified 81 patients meeting criteria with a median procedural age of 3 years (1 year-8 years), and median weight of 12 kg (4-15 kg). Successful device closure was achieved in 95.1% (77/81) and in 4.9% (4/81), the procedure was aborted. There was 1 major (1.2%) and 1 minor (1.2%) complication, total complication rate (2.4%). 100% of the referrals had right heart enlargement and exertional dyspnoea, 18.5% had recurrent lower respiratory tract infection and 9.9% had failure to thrive. Rate of resolution of residual shunt was 95.1%. at post-procedure day 1 and 98.8% at post-procedure 3 and 6 months respectively. Conclusions: Percutaneous atrial septal defect closure can be done effectively and safely in symptomatic children weighing less than 15 kg in experienced centres. However, deferral for closure until the historically established timeline of around 4-5 years of age should be strongly considered in asymptomatic children.

Pseudoaneurysm of aorta after transcatheter closure of patent ductus arteriosus.

Aortic pseudoaneurysm is a rare but life-threatening complication after transcatheter closure of patent ductus arteriosus (PDA) with only a few reported cases in literature. We report a case of an 18-month-old child who was diagnosed to have pseudoaneurysm of the aorta after 6 months of transcatheter closure of PDA. It was diagnosed on routine follow-up on echocardiography evaluation. Computed tomography chest is the imaging modality of choice for evaluation of these patients which showed large saccular aneurysm arising from distal aortic arch beyond origin of left subclavian artery. Any aneurysm more than 30 mm should be treated irrespective of symptoms. Treatment modalities are surgical resection of the aneurysm (as in our patient) or thoracic endovascular aortic repair. In our case, surgical resection of aneurysm was performed. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-023-01619-z.

Transcatheter trans-septal antegrade closure of muscular ventricular septal defects in young children.

BACKGROUND: Surgical or transcatheter closure of muscular ventricular septal defects (mVSDs) in young children may be technically challenging and associated with significant complications. OBJECTIVE: To assess the feasibility of trans-septal antegrade closure of mVSD in a selected subset of young children. METHODS: This is a prospective study from a single centre from July 2011 to March 2013. Nine infants and children with single or multiple mVSDs were included in the study. The median age and weight were 6 months (range 4-18 months) and 4.5 kg (range 3.8-6.2 kg), respectively. Trans-femoral trans-septal antegrade technique was used in eight children. One child was excluded from the study because of abnormally tortuous anatomy of both the femoral veins and subsequently underwent VSD device closure by the trans-jugular approach. The follow-up evaluation included chest X-ray, ECG, and echocardiogram at 1 month, 3 months, 6 months, and 1 year. RESULTS: The defects were closed successfully in all eight patients using Amplatzer mVSD device in 5 and Amplatzer Duct Occluder II in 3. Moderate mitral regurgitation due to entrapment of the anterior mitral leaflet occurred in one patient with a posteriorly located mVSD, necessitating removal of the device, and surgical closure of the mVSD. The small additional residual mVSD in one other patient closed spontaneously during the follow-up. CONCLUSIONS: Transcatheter trans-septal antegrade closure of mVSD in young children is technically feasible and merits further consideration. Symptomatic relief in multiple mVSD can be achieved after closing larger defects.

Transcatheter closure of large ostium secundum atrial septal defects in symptomatic small children: A single-center retrospective study.

Background: In general, the risks associated with transcatheter atrial septal defect (ASD) device closure are reported to be relatively low, but the evidence stems from trials involving adults and older children. Current guidelines do not recommend ASD device closure in children with defect sizes >20 mm due to limited data available in this group of patients. This retrospective study sought to determine the clinical and procedural characteristics of successful transcatheter ASD device closure in small children with large defects and assess the complication rates and reasons for unsuccessful device closure. Methods: We retrospectively reviewed the data of all patients who underwent elective transcatheter closure of ostium secundum ASD in our department between September 2013 and February 2022. All children weighing <20 kg, requiring a device of size 20 mm or greater, were included. Major and minor complications were predefined and indications for referral were evaluated. Echocardiogram reports were reviewed from the time of referral, postcatheterization day 1, and at 1-year follow-up. Results: We identified 40 patients meeting inclusion criteria with a median (interquartile range [IQR]) procedural age of 5 (4-7) years and median (IQR) weight of 14 (12-18) kg. Successful device closure was achieved in 39 patients with a success rate of 97.5%. The total complication rate was 2.5% (95% confidence interval: 0.44%- I2.8%) with only 1 major complication. All children had right heart enlargement and exertional dyspnea, 30% of patients had recurrent lower respiratory tract infections, and 10% had failure to thrive. At 1-year follow-up, a transthoracic echocardiogram showed a well-endothelialized device in a stable position in all the patients, and none of the patients had a residual shunt. Conclusion: In experienced centers, percutaneous ASD closure of large defects in symptomatic small children can be done effectively and safely with a great degree of predictability and a low complication rate.

Real-Time Three-Dimensional Transthoracic Echocardiography as a Decision-Making Tool for the Management of Postmyocardial Infarction Ventricular Septal Rupture: Guiding the Percutaneous Transcatheter Closure.

Postmyocardial infarction ventricular septal rupture (PI-VSR) is a rare but lethal complication of acute myocardial infarction (AMI). The diagnosis and management of AMI remain challenging. When VSR is suspected, transthoracic and/or transesophageal echocardiography at patient's bedside is a test of choice for early diagnosis and therapeutical guidance. We aim to discuss the management of patients with VSR due to AMI with the focus on transcatheter closure management guided by real-time three-dimensional (RT3D) transthoracic echocardiography (TTE). A 64-year-old male patient was diagnosed with recent anterolateral ST elevation myocardial infarction and complication intra VSR as its complication. After remeasurement of the defect by TTE, we found an 8-11 mm defect in VSR. We performed transcatheter closure for VSR guided by RT3D TTE using Septal Occluder device No. 14. Evaluation after the procedure by TTE revealed that the device was well-seated. Percutaneous closure of PI-VSR may be considered in hemodynamically unstable patients if the risk of surgery is deemed to be too high or the anatomy is amenable to device insertion. RT3D echocardiography allows better delineation of the size and shape of the rupture, while serves as a guide during percutaneous transcatheter PI-VSR closure.

Transcatheter para mitral annular ring leak device closure - A case report.

Para mitral annular ring leakage can occur following ring dehiscence after mitral annuloplasty. Percutaneous device closure of para-annular ring leakage can be performed successfully to treat such regurgitations with good transesophageal echocardiography guidance and patient selection. While para valvular device closure has been described in the medical literature, there have been few anecdotal reports published on para ring leak device closures. In this case, we highlight our experience from the successful closure of a para mitral annular ring closure with an AVP III device. The patient had a para annular ring regurgitation post coronary artery bypass grafting with mitral ring annuloplasty presenting with hemolytic anemia and acute renal failure, successfully treated by percutaneous device closure. Learning objective: This report describes the safety and effectiveness of a transcatheter para ring leak closure with an AVP III device. We applied the principles of device closure of paravalvular leak from our experience and related data from literature for this case and describe various hardware and techniques used for a successful closure of a para mitral ring leak.