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.

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.

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.

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.

Application of Vessel Navigator™ fusion imaging software in a complex transcatheter palliation of Tetralogy of Fallot with pulmonary atresia.

Extreme pulmonary artery hypoplasia in cyanotic malformations precludes palliative surgeries. When aortopulmonary collaterals (APC) in such patients are also hypoplastic, their unifocalization to create a neopulmonary vasculature is also hampered. Stent angioplasty of the outflow or collateral arteries may reduce hypoxia but is challenging in tortuous and atretic tracts. Fusion imaging overlays anatomical data from computed tomography during adult structural interventions, but its use is not often reported in young children with complex cyanotic malformations. This report shows utility of fusion imaging in pulmonary atresia with extremely hypoplastic pulmonary arteries and stenotic APC to guide stenting of outflow tract and collaterals.

Transcatheter closure of multiple secundum atrial septal defects using multiple occluder devices: A comparative experience between pediatric and adult patients.

Background: Device closure of multiple atrial septal defects (MASDs) is frequently done using a single centrally deployed septal or cribriform occluder, but multiple devices are needed for large defects separated more than 6 mm. There is a concern about complications while using multiple devices, especially in children. Methods: Patients who received multiple devices for closure of MASD were grouped according to their age and analyzed for procedural techniques, immediate and late complications. MASDs closed by a single device were not included. Balloon sizing was done when echocardiographic images were suboptimal before simultaneous device deployment through two venous accesses or sequential deployment through one access. Duration and number of antiplatelet drugs and residual flows were analyzed on follow-up. Results: Twenty-five patients received multiple devices. Balloon interrogation was performed in 16/18 adults but only in 2/7 children. Device size was 2-5 mm larger than echocardiographic defect size or equal to balloon waist. There were no procedural failures; 7/25 showed small postprocedural residual flows. Complications including embolization in one, arrhythmia in one, and cobra deformity in two were managed successfully. On a median follow-up of 5.5 years (1-12 years), residual flows disappeared in 4/7 and there were no major late complications. Conclusions: Use of multiple devices for closing MASD is feasible with good technical success. Echocardiography and balloon interrogation are the keys for success. Simultaneous deployment is often needed and sequential delivery is feasible rarely if the defects are far apart. Minor residual leaks are common but improve on follow-up. There are no significant new complications on long-term follow-up.

Single center experience of transcatheter closure of mitral and aortic Paravalvular leaks using the new rechristened rectangular Amplatzer PVL plug.

Amplatzer Paravalvular leak (PVL) plug is rectangular in shape, that might suit closure of crescentic PVL. Among 79 transcatheter PVL closures from a single center, a subgroup of 16 patients who received Amplatzer PVL plugs were analyzed. All procedures were successful, as the plug auto-oriented to the leak, without mechanical leaflet interference, though needing additional 31 devices. Two patients needed an elective re-intervention. NYHA class improved from III-IV before procedure to less than II after procedure. Complications were not directly related to the Amplatzer PVL plug. The rectangular shape for crescentic leaks, auto-orientation and non-interference with mechanical leaflets were good attributes.

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.

A simple mortality risk prediction score for viper envenoming in India (VENOMS): A model development and validation study.

BACKGROUND: Snakebite is a neglected problem with a high mortality in India. There are no simple clinical prognostic tools which can predict mortality in viper envenomings. We aimed to develop and validate a mortality-risk prediction score for patients of viper envenoming from Southern India. METHODS: We used clinical predictors from a prospective cohort of 248 patients with syndromic diagnosis of viper envenoming and had a positive 20-minute whole blood clotting test (WBCT 20) from a tertiary-care hospital in Puducherry, India. We applied multivariable logistic regression with backward elimination approach. External validation of this score was done among 140 patients from the same centre and its performance was assessed with concordance statistic and calibration plots. FINDINGS: The final model termed VENOMS from the term "Viper ENvenOming Mortality Score included 7 admission clinical parameters (recorded in the first 48 hours after bite): presence of overt bleeding manifestations, presence of capillary leak syndrome, haemoglobin <10 g/dL, bite to antivenom administration time > 6.5 h, systolic blood pressure < 100 mm Hg, urine output <20 mL/h in 24 h and female gender. The lowest possible VENOMS score of 0 predicted an in-hospital mortality risk of 0.06% while highest score of 12 predicted a mortality of 99.1%. The model had a concordance statistic of 0·86 (95% CI 0·79-0·94) in the validation cohort. Calibration plots indicated good agreement of predicted and observed outcomes. CONCLUSIONS: The VENOMS score is a good predictor of the mortality in viper envenoming in southern India where Russell's viper envenoming burden is high. The score may have potential applications in triaging patients and guiding management after further validation.

Early multicenter experience of Melody valve implantation in India.

BACKGROUND: Transcatheter valves provide a safe and effective alternative to surgery for treating dysfunctional right ventricular outflow tracts (RVOTs). We present our early multicenter experience of percutaneous pulmonary valve implantation (PPVI) using Melody valve (Medtronic Inc., Minneapolis, MN). METHODS: Patients with stenosed conduits or degenerated bioprosthetic valves in RVOT with combined stenosis and regurgitation were evaluated for suitability of Melody valve implantation. After undergoing an initial structured training, PPVI using Melody transcatheter pulmonary valve (TPV) was guided by an approved proctor. Conduits were serially dilated and prestented with careful coronary interrogation, and bioprosthetic valves were dilated with high-pressure balloons. Clinical and echocardiographic follow-up was performed at 6 monthly intervals. RESULTS: Fifteen patients (three females) aged 23.1 ± 9.5 years in NYHA Class II-III underwent Melody TPV implantation in four Indian centers. The underlying anatomy comprised surgically implanted bioprosthetic valves for pulmonary regurgitation (n= 5), conduit repair for pulmonary atresia (n = 4), Rastelli repair (n = 3), truncus (n = 1), and Ross procedure (n = 2). Twelve patients had more than one previous surgery. Doppler gradient decreased from 74.2 ± 21.5 mmHg to 10.2 ± 4.5 mmHg after the PPVI. At a median follow-up of 14 months (1-39 months), all the patients were in NYHA Class I with echocardiographic gradients of 8 ± 5.7 mmHg with no evidence of pulmonary regurgitation. There were no major procedural adverse events or deaths. CONCLUSIONS: Our early experience shows encouraging results of the PPVI program in India with proctored case selection and meticulous planning. It also confirms the safety and efficacy of Melody TPV for treating dysfunctional RVOT in postoperative patients.

Outcomes of Venus P-valve for dysfunctional right ventricular outflow tracts from Indian Venus P-valve database.

BACKGROUND: Balloon-expandable pulmonary valves are usually not suitable for dilated native outflow tracts. METHODS: Indian Venus P-valve registry was retrospectively analyzed for efficacy, complications, and midterm outcomes. Straight valve was used in prestented conduits in patients with right ventricular pressure above two-thirds systemic pressure and/or right ventricular dysfunction. Flared valve 1-4 mm larger than balloon waist was used in native outflow in symptomatic patients, large ventricular volumes, and ventricular dysfunction. OBJECTIVES: A self-expanding porcine pericardial Venus P-valve is available in straight and flared designs.. RESULTS: Twenty-nine patients were included. Straight valve was successful in all seven conduits, reducing gradients significantly, including one patient with left pulmonary artery (LPA) stent. Flared valve was successfully implanted in 20 out of 22 native outflow tracts. Sharp edges of the older design contributed to two failures. Complications included two migrations with one needing surgery, endocarditis in one, insignificant wire-frame fractures in three, and groin vascular complication in one patient. There were no deaths or valve-related reinterventions at a mean follow-up of 47.8 ± 24.5 months (1-85 months). Modifications of technique succeeded in three patients with narrow LPA. There was significant improvement in symptoms, right ventricular volume, and pulmonary regurgitant fraction. CONCLUSION: Straight and flared Venus P-valves are safe and effective in appropriate outflow tracts. Straight valve is an alternative to balloon-expandable valves in stenosed conduits. Flared valve is suitable for large outflows up to 34 mm, including patients with LPA stenosis. Recent design modifications may correct previous technical failures. Studies should focus on durability and late complications.

A covered stent used in aortic coarctation migrates proximally during deployment causing transverse arch obstruction: Transcatheter repositioning after one month.

Stent angioplasty with covered stents to avoid risk of aortic injury is the preferred mode of management of coarctation of aorta in adults and older children. Severe isthmic coarctation in an adult male with uncontrolled systemic hypertension was managed at another institution using a covered stent. A proximal stent migration during deployment resulted in obstruction of transverse aortic arch and left subclavian artery and was recognized one month after the procedure. This resulted in significant aortic gradients and left arm hypoperfusion. It was managed successfully by use of snares and additional overlapping stents, the first of this type in literature. Awareness of factors leading to stent migration and techniques involved in repositioning these stents may help cardiologists who deal with these interventions. .