Transcatheter Correction of Superior Venacaval Form of Sinus Venosus Defects Using Balloon-Mounted Covered STENTS.

Superior sinus venosus defects (SVD) are interatrial communications located above the confines of the oval fossa, where unroofing of the right upper pulmonary vein leads to its anomalous drainage to the superior venacava. Recent emergence of transcatheter closure of these defects using covered stents is an attractive alternative option especially in adults with additional comorbidities. This article focuses on various aspects of non-surgical closure of SVD, including patient selection, appropriate hardware options, step-by-step procedural details, evolution and modifications in the techniques over the last decade, protocols for follow-up evaluation, and potential complications associated with this intervention.

Different mechanisms for persistent and residual left-to-right shunt after transcatheter sinus venosus defect closure and their management.

Transcatheter closure of superior vena cava (SVC) form of sinus venosus defects (SVDs) using covered stents is emerging as an alternative to surgery in the current decade. A covered stent placed in the cavoatrial junction creates a roof for the right upper pulmonary vein (RUPV) that stops the left-to-right shunt and redirects the vein to the left atrium. While surgical literature has clearly documented the incidence of stenosis of SVC and RUPV, sinus nodal dysfunction, and persistent residual shunts following surgical correction, it is imperative to have similar data after this new transcatheter intervention on the incidence of complications and follow-up outcomes. Since patients with pretricuspid shunts are often clinically asymptomatic, correction is primarily performed to prevent a persistent right heart volume overload and allow remodeling of the heart chambers. Any residual left-to-right shunt after a correction will result in persistent right heart dilatation. Residual flows can result from various mechanisms, including lack of apposition of the covered stent to the free edge of the SVD, fabric breach, and persistent anomalous drainage of additional right-sided pulmonary veins that drain very high in the SVC or can be due to a coexistent defect in the oval fossa. This review analyzes the different mechanisms, explains the transesophageal and angiographic images for each one, and offers solutions tailored for various reasons. Different mechanisms warrant different treatment principles. A solution for residual shunt from one mechanism may not be appropriate for residual flow through another mechanism. A thorough understanding would aid the operator in effective interventions for these SVDs.

Innominate vein occlusion by the fabric of covered stent during transcatheter closure of sinus venosus defects - Causes, management, and outcome.

Transcatheter sinus venosus defect (SVD) closure with covered stents is emerging as an alternative to surgery. An adequate anchor zone in the superior vena cava is mandatory for the stability of the covered stent to prevent caudal embolization. There is a potential risk of innominate vein occlusion by the fabric of the covered stent in patients with a very short superior caval vein. Three among a total of 105 patients who underwent SVD closure at our institution developed innominate vein occlusion. Predisposing anatomical factors, identification and management of occluded innominate vein, and follow-up outcomes are discussed.

Aortico right atrial tunnel - Clinical presentation, transcatheter management, and follow-up from a large cohort of patients.

Background: Aortico right atrial tunnel (ARAT) is a rare extracardiac communication between the aorta and the right atrium with two anatomical types. A recent global review identified 59 patients. Methods: Patients with ARAT from two centers were analyzed for their demographics, symptoms, morphology, management, and follow-up thromboprophylaxis. Results: Among 21 patients including 8 males with a median age of 3 years (18 days-72 years) diagnosed as ARAT, 12 (57%) had posterior tunnels and 9 had anterior tunnels. Four patients had multiple exits. Eighteen tunnels were closed after arteriovenous circuit formation. Six patients (29%) weighing <10 kg presented early with heart failure. Transcatheter closure normalized the hemodynamics including in one infant after failed surgery. Two elderly patients (10%) above 60 years presented with angina and atrial fibrillation. The rest were asymptomatic. Occluders were positioned in the narrow proximal aortic end of the tunnel in all except two patients, where the distal atrial end was closed. All procedures were successful without complications. There was one late death after 1 year from subarachnoid hemorrhage. At a median follow-up of 96 months, all survivors were asymptomatic. Thromboprophylaxis with dual antiplatelets for 1-2 years followed earlier was recently changed to aspirin with Coumadin. Complete remodeling occurred when the proximal aortic end was closed, but partial persistence of the track was noted after distal closure. Conclusions: This largest cohort of ARAT showed the safety and efficacy of transcatheter closure even in neonates. The narrow proximal aortic end should be the target for closure rather than the distal atrial end to achieve complete remodeling.

Septal venous channel perforation during left bundle branch area pacing: a prospective study.

AIMS: To characterize the diagnosis, frequency, and procedural implications of septal venous channel perforation during left bundle branch area pacing (LBBAP). METHODS AND RESULTS: All consecutive patients undergoing LBBAP over an 8-month period were prospectively studied. During lead placement, obligatory septal contrast injection was performed twice, at initiation (implant entry zone) and at completion (fixation zone). An intuitive fluoroscopic schema using orthogonal views (left anterior oblique/right anterior oblique) and familiar landmarks is described. Using this, we resolved zonal distribution (I-VI) of lead position on the ventricular septum and its angulation (post-fixation angle θ). Subjects with and without septal venous channel perforation were compared. Sixty-one patients {male 57.3%, median age [interquartile range (IQR)] 69.5 [62.5-74.5] years} were enrolled. Septal venous channel perforation was observed in eight (13.1%) patients [male 28.5%, median age (IQR) 64 (50-75) years]. They had higher frequency of (i) right-sided implant (25% vs. 1.9%, P = 0.04), (ii) fixation in zone III at the mid-superior septum (75% vs. 28.3%, P = 0.04), (iii) steeper angle of fixation-median θ (IQR) [19 (10-30)° vs. 5 (4-19)°, P = 0.01], and (iv) longer median penetrated-lead length (IQR) [13 (10-14.8) vs. 10 (8.5-12.5) mm, P = 0.03]. Coronary sinus drainage of contrast was noted in five (62.5%) patients. Abnormal impedance drops during implantation (12.5% vs. 5.7%, P = NS) were not significantly different. CONCLUSION: When evaluated systematically, septal venous channel perforation may be encountered commonly after LBBAP. The fiducial reference framework described using fluoroscopic imaging identified salient associated findings. This may be addressed with lead repositioning to a more inferior location and is not associated with adverse consequence acutely or in early follow-up.

Assessing the State of Training in Congenital Interventional Cardiology: A Global Survey of Program Directors.

This study aimed to evaluate the current state of congenital interventional cardiology training worldwide, with a focus on case volumes, competency assessment, and the need for ongoing mentorship during early career stages. A survey was conducted among program directors (PDs) of congenital interventional training programs across the globe. The survey gathered data on training pathways, case volumes, types of procedures performed, trainee competency assessment, and the role of ongoing mentorship. Of the 79 PDs who completed the survey, it was observed that training pathways and case volumes varied significantly, particularly between the United States and other countries. Most PDs reported an annual laboratory case volume of >500 congenital cardiac cases, with most cases being interventional. While trainees demonstrated competency in simple procedures (diagnostic cases, simple ASD closure), complex interventions (such as patent ductus arteriosus closure in premature infants) require ongoing mentorship for graduates. PDs recommended a minimum case volume of 400 total cases for trainees, including 250 interventional cases. In addition to case volumes, assessing trainee competency was deemed important, with clinical reasoning, judgment, skillset, teamwork, and complication management being key areas of evaluation. The study highlights the variability in congenital interventional cardiology training and the need for ongoing mentorship during the early career years. External mentorship programs, facilitated by national and international societies, are proposed to provide critical support for early career interventionalists thus enhancing patient care for congenital heart disease. Ultimately, the findings of this survey may serve as a framework for future training standards and guidelines in this specialized field.

Transcatheter Covered Stent Exclusion of Superior Sinus Venosus Defects.

BACKGROUND: Transcatheter correction of sinus venosus defects (SVDs) using balloon-mounted covered stents provides an attractive surgical alternative. Surgery may be complicated by superior vena caval or right upper pulmonary vein (RUPV) stenosis, sinus nodal dysfunction, and residual additional pulmonary veins. OBJECTIVES: Being a new intervention, technical modifications would simplify the procedure, improve universal applicability, and reduce or tackle complications. METHODS: Patients were included if balloon interrogation of cavoatrial junction confirmed closure of SVD and redirected RUPV to the left atrium. A single-center experience was analyzed to summarize the procedural modifications over 8 years. Transesophageal echocardiogram (TEE) on follow-up was done to identify residual shunt, RUPV flows, and stent thrombosis. RESULTS: A total of 100 patients including 9 children with a median age of 35 years (range, 4-69 years) underwent SVD closure after balloon interrogation. Among 57 patients balloon interrogated in the first 5 years, 70% underwent transcatheter closure, with 2 failures. RUPV occlusion caused the exclusions. Inclusions improved to 94% among the subsequent 65 balloon interrogations when RUPV protection was implemented, with 1 failure. Stent embolization caused the 3 failures warranting surgery. Recent modifications included limited transesophageal echocardiogram without anesthesia, avoiding venovenous circuit, interrogation with semicompliant balloons, trans-septal RUPV protection, overlapping stents to permit additional vein drainage to superior vena cava and tackle embolizations. There were no deaths. Minor complications included stent embolizations stabilized in catheterization laboratory in 2 patients, left innominate vein jailing in 2 patients, insignificant residual flows, and nonocclusive asymptomatic stent thrombosis in 4 patients. CONCLUSIONS: Procedural success was 97%. Recent modifications increased patient inclusions, decreased complications, and simplified the intervention.

A rare variant of scimitar syndrome characterised by right pulmonary vein drainage to portal vein with eventeration of diaphragm.

While infradiaphragmatic total anomalous pulmonary venous drainage to portal vein is well described, hemianomalous drainage of right pulmonary veins to portal vein in Scimitar syndrome has not yet been reported.

Is There a Role for Alcohol Septal Ablation in Young Patients with Medically Refractory Hypertrophic Obstructive Cardiomyopathy?

Surgical myectomy is recommended for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) after optimal pharmacological therapy. Percutaneous transluminal septal myocardial ablation (PTSMA) is reserved for high-risk adults. Symptomatic patients below 25 years underwent either surgery or PTSMA after heart-team discussion and informed consent. Echocardiography assessed gradients in surgical group. PTSMA group underwent invasive transseptal hemodynamic assessment, selective coronary angiography and super-selective cannulation of septal perforators using microcatheters. Contrast echocardiography through the microcatheter identified the myocardial target for PTSMA. Hemodynamic and electrocardiographic monitoring guided alcohol injection. Both groups were continued on beta-blockers. Symptoms, echocardiographic gradients and Brain natriuretic peptide (NTproBNP) measurements were assessed on follow-up. Twelve patients aged 5-23 years (11-98 kg) formed the study group. Indications for PTSMA in 8 patients included abnormal mitral valve anatomy warranting replacement (n = 3), Jehovah's witness (n = 2), severe neurodevelopmental and growth retardation (n = 1) and refusal of surgery (n = 2). PTSMA targeted first perforator (n = 5), second perforator (n = 2) and anomalous septal artery from left main trunk (n = 1). Outflow gradient reduced from 92.5 ± 19.7 to 33.1 ± 13.5 mmHg. At a median follow-up of 38 months (range 3-120 weeks), the peak instantaneous echocardiographic gradient was 32 ± 16.5 mmHg. Gradient reduced in four surgical patients from 86.5 ± 16.3 mmHg to 42 ± 14.7 mm Hg. All patients were in NYHA class I/II on follow-up. The mean NTproBNP in PTSMA group reduced from 6084 ± 3628 pg/ml to 3081 ± 2019 pg/ml; it was 1396 and 1795 pg/ml in surgery. PTSMA may be considered in medically refractory high-risk young patients. It relieves symptoms and reduces gradient. Though surgery is preferred in young patients, PTSMA may have a role in selected patients.

Endoleak in covered CP stent causes procedural failure during transcatheter closure of sinus venosus defects.

Transcatheter sinus venosus defect closure uses a long covered stent of appropriate length and diameter across the cavoatrial junction after balloon interrogation. The fabric in the covered stent creates a roof for the right upper pulmonary vein that closes the interatrial communication and redirects the vein into the left atrium behind the stent. A fabric tear in the covered stent may cause endoleak that will result in residual flows across the struts of the covered stent, causing procedural failure. This report highlights the identification of fabric leak by angiography and transesophageal echocardiography and steps to overcome this complication by the placement of another overlapping covered stent.

A rare unreported complication following transcatheter correction of sinus venosus defect.

Transcatheter correction of superior sinus venosus defects using covered stent is increasingly reported in the literature and provides an alternative option to surgery in appropriately selected adults. Being a new intervention, meticulous attention to procedural techniques and precise surveillance imaging modalities are vital to detect and avoid potential early and late complications. This report highlights the occurrence of a residual interatrial communication following covered stent placement and large subclinical asymptomatic nonocclusive thrombus formation at the right atrial end of the stent. The management of both these complications is also highlighted in this report.

Life long surveillance is warranted as coronary artery remodels variably after treatment of adult patients with anomalous left coronary artery origin from pulmonary artery.

Anomalous left coronary artery origin from pulmonary artery causes heart failure in infancy from ischemia and secondary mitral regurgitation. Rich intramyocardial collateralization may permit survival to adult age, where coronaries become tortuous and aneurysmally dilated. Surgery in adults involves left coronary ligation and providing a bypass graft to the left system, unlike coronary translocation adopted in infants. Unfavorable coronary remodeling in operated adults may lead to late coronary thrombotic occlusions. Two adults with markedly dilated tortuous coronary arteries showed variable remodeling after corrective intervention that impacted outcomes on follow-up. We stress the need for lifelong angiographic surveillance in older patients.

Simultaneous Transcatheter Closure of Coexistent Superior Sinus Venosus Defects and Oval Fossa Defects.

Device closure has become the preferred procedure for treating oval fossa defects in the last two decades. More recently, transcatheter sinus venosus defect (SVD) closure has emerged as an alternative to surgery. Transcatheter stenting aims to overcome potential late surgical complications such as stenosis of the superior vena cava (SVC) and right upper pulmonary vein (RUPV), as well as sinus node dysfunction. Balloon interrogation of the cavoatrial junction is able to identify patients who are suitable candidates for nonsurgical closure. Successful closure is possible when the balloon seals the SVD and redirects the RUPV towards the left atrium. Oval fossa (secundum) defects can coexist in approximately 9-16% of patients with SVD. Among a group of 80 patients who underwent transcatheter closure of SVD, five adult patients aged between 22 and 52 years also required device closure of an associated oval fossa defect. The procedure involved simultaneous balloon interrogation of both the SVD and oval fossa defect, with continuous monitoring of the RUPV using bilateral femoral venous sheaths. Covered stent exclusion of the SVD was performed with concurrent device closure of the oval fossa defect using 12-36 mm atrial septal occluders. During the procedure, two patients required protective balloon inflation in the RUPV while expanding the covered stent. In one patient, a higher small accessory RUPV was intentionally left to drain into the SVC through the struts of a bare stent anchoring the covered stent in the upper SVC. In another patient, a second overlapping covered stent was used to address residual flows from a fabric tear that became apparent after balloon deflation. There were no vascular complications and only one patient exhibited an insignificant 6 mm residual flow from the caudal edge of the SVD during a follow-up of 5 to 72 months. In conclusion, the closure of both SVD and associated oval fossa defects can be successfully performed in a single procedure, with comparable procedural times and favourable mid-term outcomes.

Novel transcatheter intervention for iatrogenic cyanosis due to surgical rerouting of inferior vena cava to the left atrium.

Improper identification of the atrial septal defect margins during surgery and inadvertent suturing of the surgical patch to the Eustachian valve of the inferior vena cava (IVC) results in the diversion of inferior venacaval blood to the left atrium causing cyanosis. This complication has been dealt so far with surgery. We report the planning and implementation of a novel transcatheter rediversion of the IVC to the right atrium using a covered stent.

Experience with the largest custom-made 48 mm fenestrated atrial septal occluder device and its 4-year follow-up.

Atrial septal defects (ASDs) measuring <38 mm are referred for transcatheter closure. Availability of larger devices up to 46 mm extended the inclusion criteria. An elderly hypertensive male with a 44 mm secundum ASD and coexistent sick sinus syndrome and atrioventricular (AV) nodal block presented with syncope. Balloon interrogation unmasked restrictive left ventricular (LV) physiology. After AV synchronous pacing, balloon-assisted deployment of a custom fenestrated 48 mm Figulla septal occluder (Occlutech Inc., Schaffhausen, Switzerland) prevented a rise of LV end-diastolic pressures beyond 12 mmHg. Echocardiogram and computed tomography after 4 years confirmed a patent fenestration and favorable remodeling. This report of the clinical use of the largest ASD device demonstrated the feasibility of closure of extremely large defects despite a restrictive LV.

Randomized controlled trial to evaluate the effect of prophylactic amiodarone versus dexmedetomidine on reducing the incidence of postoperative junctional ectopic tachycardia after pediatric open heart surgery.

Background: Junctional ectopic tachycardia (JET) is the most common arrhythmia after pediatric open-heart surgeries (OHS), causing high morbidity and mortality. As diagnosis is often missed in patients with minimal hemodynamic instability, its incidence depends on active surveillance. A prospective randomized trial evaluated the efficacy and safety of prophylactic amiodarone and dexmedetomidine to prevent and control postoperative JET. Methods: Consecutive patients aged under 12 years were randomized into amiodarone, dexmedetomidine (initiated during anesthetic induction) and control groups. Outcome measures included incidence of JET, inotropic score, ventilation, and intensive care unit (ICU) duration and hospital stay, as well as adverse drug effects. Results: Two hundred and twenty-five consecutive patients with a median age of 9 months (range 2 days-144 months) and a median weight of 6.3 kg (range 1.8 kg-38 kg) were randomized with 70 patients each to amiodarone and dexmedetomidine groups, and the rest were controls. Ventricular septal defect and Fallot's tetralogy were the common defects. The overall incidence of JET was 16.4%. Syndromic patients, hypokalemia, hypomagnesemia, longer bypass, and cross-clamp duration were the risk factors for JET. Patients with JET had significantly prolonged ventilation (P = 0.043), longer ICU (P = 0.004), and hospital stay (P = 0.034) than those without JET. JET was less frequent in amiodarone (8.5%) and dexmedetomidine (14.2%) groups compared to controls (24.7%) (P = 0.022). Patients receiving amiodarone and dexmedetomidine had significantly lower inotropic requirements, lower ventilation duration (P = 0.008), ICU (P = 0.006), and hospital stay (P = 0.05). Adverse effects such as bradycardia and hypotension after amiodarone and ventricular dysfunction after dexmedetomidine were not significantly different from controls. Conclusion: Prophylactic amiodarone or dexmedetomidine started before OHS is effective and safe for the prevention of postoperative JET.

First-in-man use of an Indian-made balloon-expandable covered Zephyr stent and intermediate-term follow-up.

Covered stent is used in large-vessel angioplasty in anticipation of vessel wall injury. Apart from aortic coarctation, they are also used in dysfunctional right ventricular outflow conduits and find a recent role in transcatheter sinus venosus defect closure. Different methods of covering stents include glue fixation, sutureless lamination, sandwich, and sintering lamination. Covered Zephyr (Sahajanand laser technology limited, Gandhinagar, India) is a new Indian-made expanded polytetrafluoroethylene-covered balloon expandable cobalt-chromium stent. Its unique C and S links prevent foreshortening. We report the first-in-man use of this new stent in severe discrete postsubclavian coarctation of aorta and its short-term follow-up imaging.

Risk factors associated with device embolisation or malposition during transcatheter closure of patent ductus arteriosus.

BACKGROUND: Device embolisation is a serious adverse event during transcatheter duct closure. This study analyses risk factors for embolisation. METHODS: Demographic parameters, echocardiographic anatomy, haemodynamics, and procedural characteristics of consecutive duct closures in a tertiary centre over 8 years were analysed. Procedures complicated by embolisation were compared to uncomplicated procedures. RESULTS: Fifteen embolisations occurred during 376 procedures. All except one embolisation were in infants. The pulmonary artery: aortic pressure ratio was 0.78 ± 0.22. Embolisation was seen significantly more commonly in Type C tubular ducts. Vascular plugs were more significantly associated with embolisations. Logistic regression analysis showed device embolisation was significantly higher in age group of < 6 months compared to 6-12 months (p = 0.02), higher in those with tubular ducts versus conical ducts (p = 0.003), use of vascular plugs compared to conventional duct occluders (p = 0.05), and in duct closure with undersized devices (p = 0.001). There was no in-hospital mortality. Three patients needed surgical retrieval while others were successfully managed in catheterisation laboratory. CONCLUSIONS: Device embolisation complicates 4% of transcatheter duct closures, with need for surgery in one-fifth of them. Larger ducts with high pulmonary artery pressures in younger and smaller infants are more often associated with device embolisation. Tubular ducts are more prone for embolisation compared to usual conical ducts. Softer vascular plugs are often associated with embolisations. Intentional device undersizing to avoid vascular obstruction in small patients is a frequent risk factor for embolisation. Precise echocardiographic measurements, correct occluder choice, proper technique and additional care in patients with high pulmonary artery pressures are mandatory to minimise embolisations.