Percutaneous interventions in CHD Shunt lesions

ASD device closure

Natural history:  40 yrs : Majority are symptomatic (exertional SOB,palptn,reduced FC,frequent lung infns,RHF)  Life expectancy reduced  PAP increases with age.. Severe PAH dvpt is rare(<5%) & its dvpt requires addl factors like genetic predisposition.

1 st device …. Plastic button (thoracotomy) … 1959 … Hufnagel & Gillespie 1 st successful transcatheter closure (ASD) … King & Mills … ESC guidelines Device closure  first choice for OS ASD whenever feasible(stretched diameter <38 mm and sufficient rim of 5 mm except towards the aorta)[as in ∼ 80% of patients]. At present there are no lower age limitations which preclude device implantation. In many cases, because of the size of the device and its introduction system device, applicability may be limited to patients who weigh >8 to 10 kg.

INDICATIONS :[ OS ASDs ] ASDs with e/o RV overload or Qp Qs ratio >1.5. Lack of symptoms is not a contraindication for repair. Small ASDs(<5 mm) without e/o Rt heart enlarg  No impact on natural history ; can be left alone unless a/w paradoxical embolism Contraindications: Small hemodyn insignif ASD Large ASD(>38mm) Deficient rims Severe PAH [PVRI>5 WU] Severe LV dysfunction Ostium primum/sinus venosus ASDs/pulm venous anomalies

Outcome is best with repair at age <25 years. ASD closure after 40 years no longer appears to affect the frequency of arrhythmia development during follow-up. Closure at any age  patients benefit with regard to morbidity (exercise capacity, shortness of breath, right heart failure). Poor LV function (systolic and diastolic) may cause pulmonary congestion after ASD closure and may require pre-interventional testing (balloon occlusion with reassessment of haemodynamics) and treatment.

Closure in elderly : r/o LV Diast Dysfn : may benefit from diuretics …

ECHO evaluation : location, no:, size, rims of the defect, pulm venous anatomy Very difficult to put device via IJV/SCV.. In cases of IVC/iliac vein interruption,hepatic vein access may be needed.

ASD CLOSURE DEVICES :

ASO : 2 flat disks.. LA disk > RA disk by about 4 mm in diameter … RA disk is 8-10 mm > than the waist…waist diameter decides the size of the device … available from 4-40 mm … thru 6-12 F delivery sheath Advantage : complete retrievability …. Useful in unsatisfactory deployment …[‘metal memory’ property of nitinol]

GORE ® HELEX ® SEPTAL OCCLUDER circular wire frame (nitinol  nickel-titanium metal alloy) covered with a thin ePTFE membrane. Once inside the heart, the membrane-covered wire frame of the GORE HELEX Septal Occluder forms two opposing discs connected in the middle.

The HELEX occluder is suitable for closure of small to moderate-sized defects (18 mm in diameter) and is easily repositionable or removable even after release from the catheter delivery system.

CARDIOSEAL : two joined square shaped umbrellas made of a cobalt wire alloy skeleton to which a knitted dacron fabric is attached … addition of a unique self centered mechanism via a microcoil spring  STARFLEX device

Bodys response to the device Within a few days, the body’s own tissue will begin to grow over the device. By 3 to 6 months, the device is completely covered by heart tissue and at that point becomes a part of the wall of the patient’s heart.

Post procedure After transcatheter occlusion, patients are generally discharged the next day. Six months of treatment with aspirin with or without clopidogrel is recommended to prevent thrombus formation. Successful closure occurs in 80 to 95% of patients.

PROCEDURE Vascular access … 7 F sheath in the RFV ASD crossed with a multipurpose catheter & kept in RUPV ” wire with 1 cm floppy tip is placed in the LUPV … delivery sheath is introduced over the wire with a dilator & tip of the sheath is positioned in the LUPV.. Then remove the dilator & wire slowly … allow the sheath to backbleed freely.. then device is screwed onto the delivery cable & the device cable assembly is advanced upto the tip of the sheath …. Then the delivery sheath is withdrawn (to mid LA level) until it exits the PV… then the cable is fixed firmly & retract the sheath over the cable …. Deploys the LA disk

Echo guidance to assess the parallel alignment of the LA disk to the IAS. Then the entire sheath/cable is pulled back as one unit …. Deploys the connecting waist Further retraction of the sheath over the cable & continuous pulling of the entire unit towards the IVC deploys the RA disk… then the device position is assessed with echo [relation to rims,SVC,CS,?residual shunt] Assess the stability of the deployed device (“Minnesotta wiggle”-gently push the cable [sheath fixed] to LA & then pull backward towards the IVC … stable device wont move in both directions)

Stable? … release the device [by rotating the pinvise in a counterclockwise direction]

Follow-up With in 24 hrs … echo is done to confirm the position of the device & to look for any residual shunts. Assessment of residual shunt, RV size and function, TR and PAP by echo and also assessment of arrhythmias Patients repaired under the age of 25 years without relevant sequelae or residuae (no residual shunt, normal PAP, normal RV, no arrhythmias) do not require regular follow-up. Patients with residual shunt, elevated PAP or arrhythmias (before or after repair) and those repaired at adult age (esp >40 years) should be followed on a regular basis.….regular follow-up during the first 2 years and then, depending on results, every 2–4 years is recommended.

Late arrhythmias after surgical repair at age <40 years are most frequently IART or Afl which can be successfully treated with RFA. Without repair or with repair after 40 years, AF becomes more common and may require antiarrhythmic therapy Sick sinus syndrome or heart block are less common. RV size improves rapidly with in 1 month & by 1 yr,only 29% have RV enlargement Multiple ASDs separated by >7 mm may need multiple devices Complete 6 months ? …. Discontinue IE prophylaxis/aspirin

Complications Device embolisation/malposition Air emb Device erosion Device thrombus EKG changes … rarely high grade AVB esp with large defects AR : cause may be overgrowth of the device by tissue, leading to changes in interatrial septal geometry and traction on the root of the non-coronary aortic cusp.

Device embolisation Incidence 0.5% Mainly due to …..deficient septal margins … use of undersized devices Usually occur during the first 24 hrs post deployment… usually well tolerated unless the device aligns parallel with the plane of any heart valve Most commonly embolise to RA Retrieved percutaneously ; sometimes surgery may be needed Malformation of the Amplatzer occluder during deployment  ’cobra head’ configuration. The device could be retrieved into the long sheath and redeploy correctly.

Arrhythmias % Mostly transient …. SVT …. CHB less common (<1%) AF or SVT after ASO device implantation  possible explanation could be the stretching of the IAS by the central waist of the device. Arrythmias during follow up : difficult to differentiate whether it is device related or part of the disease process

Device erosion [aortic root/ cardiac walls  perforation,tamponade] : Incidence 0.1% Vulnerable sites : anterosup atrial wall & adjacent aorta Increased risk in pts with deficient aortic &/or superior rims; oversized devices Pts with peric 24 hrs should have closer follow up

Residual Shunts : Usually insignificant 11.7% immediately after  9% at day 1  5.9% at 6 months  2 % at 24 months None required Sx/ addl interventions

Thrombus formation over the device : Incidence 0.2% Post-procedure AF and persistent atrial septal aneurysm were significant predictors of thrombus formation ASO less thrombogenic J Ayub Med Coll Abbottabad 2009;21(3)

Several studies have shown outcomes from transcatheter device closure of secundum ASD to be comparable to surgical outcome in carefully selected adult and pediatric patients.

Surgery versus percutaneous intervention. The largest study …by Du et al … total of 614 pts with OS ASDs [442 in the device group and 154 in the surgical group] The procedural success rate (no significant residual shunt) was 95.7% for the former and 100% for the latter. Efficacy rates (defined as successful closure without major complications and without a need for surgical intervention) were not significantly different between the two groups on discharge (94.8% vs. 96.1%), at 12 months (98.5% vs. 100%) and after the 2-year study period (91.6% vs. 89.0%). Complication rate was statistically higher (24%) for the surgical group compared to the device group (7.2%), which was largely influenced by more pericardial effusion with or without tamponade in the surgical group (p < 0.001). There were no mortalities in either group.

Surgery vs Device for ASD closure

Role of ASD closure in elderly pts Transcatheter device closure of ASD in patients aged 40 years and older showed regression of RV enlargement and an improvement in FC.(Neth Heart J 2010;18: ) Effects of closure even in elderly patients results in favourable cardiac remodelling & imprvt of FC… [JACC Intv 2010; 3: ]

Recent advances : leaving a foreign implant behind might not be the ideal way to close these defects. The BioSTAR septal repair implant (NMT Medical)… a bioabsorbable device … made of acellular porcine intestinal collagen cellular matrix. …absorbed and replaced with native tissue within 2 years. The phase 1 clinical trial of the BioSTAR Evaluation Study showed excellent closure rates for PFOs & ASDs advantages are less potential for thrombus formation, erosion, arrhythmias and better accessibility to the left atrium if needed in the future.

VSD CLOSURE

Recommendation for Device Closure of M-VSDs In infants >5 kg, children and adolescents with hemodynamically significant MVSD [LV or LA volume overload or Qp Qs ratio >2:1) ….reasonable to undergo percutaneous VSD device closure [IIa] Device closure should not be done in case of inadequate space between the defect and the AV or semilunar valves

1 st VSD closure : in 1988 by James Lock et al using Rashkind PDA occluding device [Problems…large delivery sheaths, risk of embolization, inability to reposition, AR and a high rate of residual shunting] Amplatzer VSD occluder device [in 1990s] Requires the presence of a good septal rim (> 5 mm) for closure of muscular defects. Not well suited for closure of pm VSDs due to close proximity to the aortic valve, leading to the risk of aortic valve obstruction. A new Amplatzer occluder device with asymmetric discs : introduced later for pm VSDs [not FDA-approved].

(1) Retrograde transaortic access to the left ventricle. (2) A guidewire crosses retrograde from the left to right ventricle across the VSD. (3) A transfemoral venous snare retrieves the transaortic guidewire from the pulmonary artery. (4) An arteriovenous loop is exteriorized to provide a rail to deliver the rigid VSD delivery sheath. (5) The delivery sheath is positioned antegrade across the VSD. (6) The VSD occlusion device is positioned and released

Patients are discharged the next day on aspirin and endocarditis prophylaxis for 6 months. Early complications …. complete heart block especially with pm VSD closure (1–6%), aortic or tricuspid regurgitation, device dislodgement, residual shunt, ventricular rupture, air embolism, hemolysis or death. Late complications are usually uncommon…a few reports of late-onset heart block have been reported and may require close surveillance.

PMVSD-O …. now the indications for percutaneous closure were expanded also to cases with only 1 to 2 mm between the defect and the aortic valve …. Studies in the literature reported that the rate of successful closure was between 90% and 100%

PDA CLOSURE

1st described in 1967 with an Ivalon plug by Porstmann et al. Then by Rashkind et al, who used a hooked single-disk device in 1979 and a double-disk device in 1987.These systems used rather large delivery systems. In 1992, Cambier et al reported a small series using Gianturco coils to occlude small PDAs. The major advantage of this technique was the use of small (5F) delivery systems.

Indications for Transcatheter PDA occlusion …. moderate-sized or large PDA with L  R shunt that results in any of : CHF, FTT, pulmonary overcirculation (+ PAH) or an enlarged LA or LV [class1] h/o prior endarteritis [class1] reasonable in small L  R shunt with normal-sized heart chambers when the PDA is audible by auscultation[IIa] may be considered [IIb] bidirectional PDA shunt due to PAH and obstructive pulmonary vascular disease but reversible to pure L  R shunting with pulmonary vasodilators PDA with a small L  R shunt with normal heart size and an inaudible murmur

Options for percutaneous closure …. Cook detachable coils Occluder devices (Rashkind-type occluders, Amplatzer duct occluders). Both types of devices have been used with good procedural success and low morbidity rates.

Amplatzer duct occluder (ADO) … self-expanding nitinol stent…..made of a flat retention flange [on the aortic wall] and a tube (placed in the PDA itself) that contains thrombogenic material (a polyester patch sewn to the nitinol stent). The diameter of the retention flange is 4 mm larger than the tube sheath, which is in the form of a cone; the pulmonary end of the cone is 2 mm smaller than the end that is attached to the retention flange. The different Amplatzer duct occluder models refer to the size in millimeters of the two ends of the tube: 6/4, 8/6, 10/8.

PDA 97% successful with zero mortality and no significant morbidity PDAs upto 12 mm …Amplatzer duct occluder  >98% complete closure rate at 6 months with minimal complications and no mortality. PDAs >12 mm …. septal closure devices (AGA septal occluder, VSD device, NMT CardioSEAL device) or covered stents in select cases

Residual shunt : Although it is common to see initial residual shunting through an AMPLATZER PDA occluder, a multicenter trial indicated 99.7% complete occlusion at 1-year

References ESC Guidelines for the management of grown-up congenital heart disease (new version 2010) ACC/AHA 2008 Guidelines for the Management of Adults With CHD…circulation Congenital heart disease: the catheterization manual…..By Lisa Bergersen Indications for Cardiac Catheterization and Intervention in Pediatric Cardiac Disease … AHA scientific statement.. Circulation 2011

Transcatheter Closure of Perimembranous Ventricular Septal Defects Butera et al JACC 2007 Moss & Adams CHD

MCQs

1)ASD device embolisation : true is : a] incidence is 2% b] commonly to LA c]Usually does not require surgery

2]Amplatzer septal occluder for ASD : False is : (a)LA disk > RA disk by 4 mm (b)Device size = waist diameter (c)Wire mesh is made of nickel technitium alloy (d)Takes around 100 mts for the procedure

(3)ASD device closure after 40 yrs has no significant impact on: a)NYHA FC b)Arrythmias c)PAH d)RV regression

4)VSD device closure : False : a)Incidence of CHB 2% b) Only Muscular VSD can be closed by device c)Needs larger sheaths for delivery compared to ASD device d)Procedural success 95%

5)In IVC interruption, ASD device closure is done thru a) Rt subclavian vein b)Lt subclavian vein c)Internal jugular vein d)Hepatic vein

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