Handbook of Advanced Interventional Cardiology - part 10 ppt

592 Practical Handbook of Advanced Interventional Cardiology **Avoiding entangling the already deployed coil by direc- tional wire **Checking position of device prior to deployment **Closing the PDA with occluder Coarctation **A note of caution **Measuring the gradient across the coarctation **Sequential dilation of the coarctation **Advantage of MRI-compatible stents **Optimal wire position **No problem with subclavian jailing **Post-dilation with high pressure balloon **Accurate pressure gradient measurement Pulmonary valve stenosis **How to track the balloon across the valve Pulmonary artery stenosis **Stabilizing wire position in the pulmonary artery branch **Using a stiffer wire to track a stent **Reshaping the pigtail catheter INTRODUCTION Adult patients with congenital heart disease are an ex- ponentially increasing population due to improved treatment strategies for children resulting in excellent long-term survival. Newer interventional techniques and tools developed over the last 20 years are now able to treat the majority of common con- genital lesions in the catheterization laboratory instead of the operating suite. This chapter will detail percutaneous inter- ventional techniques for treating the most common congenital cardiac lesions seen in adults including patent foramen ovale (PFO), atrial septal defect (ASD), patent ductus arteriosus (PDA), coarctation of the aorta, valvar pulmonary stenosis, and branch pulmonary artery stenosis. PATENT FORAMEN OVALE Device closure of PFO was fi rst described in 1987 1 for the prevention of recurrent stroke associated with paradoxical embolus. 2 It has also been used to prevent right to left shunt- ing causing desaturation in patients with orthodeoxia-platyp- nea syndrome. 3 The foramen ovale is a fl ap valve in the atrial septum created by overlap of the superior anterior septum secundum on the inferior posterior septum primum (Figure 29-1). It is present in all fetuses during development to direct oxygenated venous return from the placenta through the inferior vena cava (IVC) across the atrial septum, bypassing the right ventricle (RV) and unexpanded lungs, to fi ll the left Percutaneous Interventions in Congenital Heart Diseases 593 ventricle (LV) allowing optimal cerebral perfusion. After birth, with redistribution of fl ow due to lung expansion resulting in an increased left atrial (LA) pressure, the PFO closes and seals permanently in 65 to 80% of people, age dependant. 4 Howev- er, in 20–35% of the normal population the foramen ovale does not fi brous closed and remains patent allowing unidirectional fl ow from right to left if right atrial (RA) pressure exceeds LA pressure. This is physiologically insignifi cant for most people unless the amount of right to left shunting is signifi cant caus- ing orthodeoxia-platypnea syndrome or an embolus crosses right to left resulting in a cryptogenic transient ischemic attack (TIA) or stroke. Approximately 55% of patients who have had a stroke have a PFO, 5 suggesting it plays an important role in many of these patients. Indications: Potential indications for PFO device clo- sure include any patient who has had or has substantial risk for a cryptogenic stroke in the setting of a PFO. Absolute indica- tions for PFO device closure remain controversial since there is limited controlled data comparing different treatment strat- egies and evaluating long-term follow-up. However, several clinical situations clearly warrant device closure, including: patients with active venous thrombus in the setting of a crypto- Figure 29-1: Lateral right atrial angiogram showing typical patent foramen ovale anatomy with a thin septum primum and thick septum secundum. LA, left atrium, PFO, patent foramen ovale, RA, right atrium, SVC, superior vena cava. 594 Practical Handbook of Advanced Interventional Cardiology genic stroke; patients with recurrent cryptogenic stroke while on anticoagulation; patients with recurrent cryptogenic stroke and contraindications to anticoagulation; and scuba divers who have had signifi cant decompression sickness but insist on continuing to dive. Based on current data PFO device clo- sure is a reasonable therapeutic alternative for patients with an initial cryptogenic stroke and no additional risk factors. Contraindications: There are no absolute contraindica- tions for device PFO closure except for patients with active thrombus in the LA and those with a known allergy to the device implant materials, particularly the nickel in nitinol, an extremely rare condition. Patients who are hyper-coagulable, particularly those with disorders that predispose to arterial clots, should be considered very carefully as the post-place- ment risk of clot formation during the endocardialization pro- cess may be signifi cantly increased. However, those patients who are predisposed to venous clots may be the very patients who benefi t the most in the long term, albeit with a poten- tially increased thrombus risk during the fi rst 6 months after implant. Patients who require anticoagulation long-term for other issues may get limited benefi t from device closure. The procedure: Over the last 14 years interventional device closure of PFO has become an attractive alterna- tive therapeutic strategy to surgical PFO closure or lifelong anticoagulation for stroke prevention. No controlled com- parative studies with these other treatment strategies exist for PFO closure although there are currently several active multi-center protocols in stroke patients comparing device closure with medical therapy. There is good comparative data from the ASD literature suggesting the effi cacy of device closure of ASD is similar to surgical closure, with a signifi cant reduction in complications, hospital stay, recovery time, and medical resource utilization. 6 Procedural success with PFO device closure is 98 to 100% with complete closure rates of 51 to 96% at 6 months if evaluated by saline contrast TEE 7–10 . Recurrent neurologic event risk following PFO device closure is 1–2% annually with a 96% 1-year and 90–94% 5-year event-free rate. 7–10 These results are signifi cantly infl uenced by patient selection since some patients who undergo device closure may have recurrent strokes unrelated to either the PFO or device. More defi nitive information regarding recur- rent stroke risk will be available from controlled randomized trials now under way comparing device closure with medical therapy. Procedural complications are uncommon, occurring in less than 2%, and include stroke, TIA, transient myocardial ischemia (the latter three due to air or clot embolism with the large delivery sheaths in the left atrium), device malposition or embolization, cardiac perforation with tamponade, and local femoral vein injury. 7 Late complications include atrial arrhyth- mias in 4%, although most are mild requiring no treatment, 11 and thrombus formation on the device. Percutaneous Interventions in Congenital Heart Diseases 595 There are currently six devices in use worldwide for PFO closure: the Amplatzer PFO Occluder (AGA Medical Corpora- tion, Golden Valleys, MN); the Button device (Custom Medical Devices, Athens, Greece); the CardioSEAL STARFlex septal occluder (Nitinol Medical Technologies, Boston, MA); the Guardian Angel device (Microneva Inc, Minneapolis, MN); the Helix septal occluder (W.L. Gore Associates, Flagstaff, AZ); and the PFO Star (Cardia Star, Bunsville, MN). All these devices are similar in that they have all have a metal frame supporting two patches, left and right atrial patches, which are connected by a central core. These devices are folded or stretched into a loader to minimize their diameter for delivery through a 9F or 10F sheath positioned across the PFO. Once delivered from the sheath, the devices expand into position and immediately obstruct fl ow by mechanically by covering the fl ap valve. The fi nal and complete seal comes from en- docardial in-growth covering the patches completely within 8 to 12 weeks. Device implantation is most typically guided by both fl uoroscopy and echocardiography (either transesopha- geal or intracardiac), although either alone will suffi ce. Pre-procedure evaluation/management: Because most patients undergo PFO device closure for prevention of stroke recurrence it is essential to evaluate the patient’s prior neurologic events and assure they were cryptogenic and likely related to the PFO. Stroke associated with paradoxical embo- lism is a diagnosis of exclusion so it is imperative to rule out other potential causes of stroke including cerebral aneurysm, carotid or vertebral vessel abnormalities, atrial arrhythmias, LA appendage thrombus, cardiomyopathy, or a hypercoagu- lable state. Standard pre-device closure evaluation includes head and neck MRI/MRA, carotid ultrasound, transesopha- geal echocardiogram with saline contrast, and hyper-coagu- lable screen including protein C and S, antithrombin III, factor V Leiden, prothrombin 20210, MTHFR, anticardiolipin antibody, and homocysteine. This latter workup is essential to help guide decisions regarding the appropriateness of implanting a device and the optimal medical strategy during the endo- cardialization process. Because of a small incidence of atrial arrhythmias after device placement, a baseline ECG should also be obtained. Standard protocols for anticoagulation, local anesthesia and antibiotic prophylaxis are listed in Table 29-1. Defi ning the anatomy A 9F or 10F sheath is placed in the femoral vein and right heart catheterization is performed using a Berman balloon- tipped or Multipurpose catheter with measurement of pres- sures and saturations in the SVC, RA, RV, and PAs to assure normal physiology and no evidence for signifi cant left to right intracardiac shunt (to exclude additional pathology, espe- cially an additional ASD or anomalous pulmonary vein). An angiogram is then performed in the low RA with the AP cam- 596 Practical Handbook of Advanced Interventional Cardiology era angled 20° RAO and 20° cranial and the lateral camera 70° LAO and 10° caudal. 24 cc of contrast is injected at a rate of 24 cc/sec. The lateral projection will profi le the PFO nicely (Fig- ure 29-1) and can be used as a road map for device delivery. TECHNICAL TIP **Shaping the tip of the catheter in order to enter the PFO: If the anatomy or size of the defect is in question cross the PFO with the Berman catheter by inserting the stiff end of a 0.035" straight wire shaped with a 45° angle at the distal 4 cm. This will give the end of the Berman catheter a “hockey stick” shape that can be easily directed slightly leftward and posterior to slip through the tunnel PFO. The balloon on the Berman catheter can then be infl ated and the catheter withdrawn to the septum against the foramenal fl ap pulling it closed (Figure 29-2). Record an image of the balloon against the septum to create an additional road map for placement of the LA side of the device when appro- priately positioned against the foramenal fl ap. If the infl ated Berman balloon easily pulls through the defect, reassess the anatomy and consider a larger device. Occasionally a pre-procedural echo will suggest a PFO with right to left shunting seen during saline contrast yet no PFO can be demonstrated by angiography or with catheter probing of the atrial septum. Consider the diag- nosis of pulmonary arteriovenous malformations that are associated with paradoxical embolism and will have right to left contrast shunting on echo that can be mistaken for a PFO shunt. Perform selective right and left pulmonary artery angiography to make the diagnosis. If present these can be treated with coil embolization. Choosing device size In general, the smallest device which effectively covers the defect should be used to minimize foreign body mass and Table 29-1 Standard protocol for anticoagulant and antibiotic prophylaxis 1. If patients are on coumadin before the procedure, hold coumadin two days before and begin daily aspirin. 2. Give heparin to have ACT maintained at >250 seconds during the procedure. 3. Local anesthesia and mild to moderate sedation are used to maintain patient comfort. 4. A dose of antibiotics (cefazolin or clindamycin) is given IV prior to device implantation to protect against procedure- related sepsis/endocarditis. Percutaneous Interventions in Congenital Heart Diseases 597 optimize closure rates. Most PFOs are 4 to 6 mm in diameter and stretch minimally in the left to right direction. Some op- erators use balloon stretch diameter to assist with device size choice. We have not found this helpful unless the anatomy is poorly defi ned on angiography and an ASD is suspected. For the Amplatzer device either the 18 mm or 25 mm devices suffi ce for most defects. If the right atrial side of the defect is quite large or a large atrial septal aneurysm is present then the larger 35 mm device can be used, assuming the total atrial size is adequate. For the STARFlex device (Nitinol Medical Technologies, Boston, MA) the 23 or 28 mm devices are adequate for most defects with the 33 mm device chosen for exceptionally large defects or those with large atrial septal aneurysms. Sheath placement The sheaths required for device closure are large but easily pass through the foramen ovale over a guidewire po- sitioned in a left pulmonary vein, preferably the left upper. A multipurpose or directional end-hole catheter such as a JR4 can be used to direct a stiff 0.035" wire with a soft tip (Rosen Figure 29-2: Lateral angiogram through long sheath in RA showing the LA side of an 18 mm AGA PFO occluder snug against the septum. 598 Practical Handbook of Advanced Interventional Cardiology or Amplatz) through the PFO and into the LUPV. The sheath and dilator are then advanced into the vein, wire and dilator re- moved and sheath cleared. It is imperative that these sheaths are cleared carefully because air embolism is directly into the systemic circulation and is by far the most common and seri- ous si de ef fec t associ ated wit h this pr oce dure. TECHNICAL TIP **Backbleed and fl ush the sheath in order to avoid air embolism: Flush the sheath continuously when advanc- ing into the LA and during removal of the dilator and wire. Refrain from negative suction on these large sheaths. Allow passive bleed back and keep the end of the sheath signifi cantly below the level of the patient’s heart to facilitate bleed back. Be aware of the patient’s breathing and be sure to time clearance of the sheath with exhalation to minimize the risk of air embolism. Give supplemental nasal cannula O 2 during sheath and device placement to minimize effects if air embolism occurs. Device positioning The device is soaked in heparinized saline and inspected for defects. It is compressed into the loader with constant fl ushing to remove any residual air and loaded into the sheath. Connect a large syringe with contrast to the side arm of the delivery sheath for hand angiography during device position- ing. Withdraw the sheath tip to the middle of the left atrium and advance the distal patch of the device out of the sheath until it expands completely. Withdraw the sheath and device together until the device is in fi rm contact with the septum. You will feel the beat of the heart on the end of the sheath and can confi rm position with your RA angiographic and balloon- sizing road maps. Perform a hand angiogram through the delivery sheath. This should outline the RA side of the septum and confi rm the distal patch position on the left atrial side snug against the septum (Figure 29-2). If the angiogram shows marked fi lling of the left atrium, the device and sheath need to be pulled more tightly against the septum. Once appropri- ate LA patch position is confi rmed the device is held fi rmly in place and the sheath withdrawn over the device, uncovering the right atrial patch. Once the right atrial patch is completely open, move the sheath and delivery cable to a neutral position and repeat a hand angiogram through the sheath to confi rm optimal position. A small residual leak through the center or edge of the device is not atypical with this injection due to distortion of the device from the plane of the septum while connected to the delivery cable. If in appropriate position, the device is released and the delivery cable removed. Percutaneous Interventions in Congenital Heart Diseases 599 TECHNICAL TIP **Device positioning across a thick septum primum and a stiff tunnel defect: Occasionally the septum pri- mum is extremely thick and creates a rigid tunnel that can- not be displaced by exerting pull on the left atrial patch. This can be recognized prior to device release by an inability to position the center point of the device on the right atrial side of the septum because the entire device is held up in the left atrial side of the stiff tunnel. After release the device will not lie fl at to the septum but the inferior portion of the left atrial patch and the superior portion of the right atrial patch will protrude from the septum due to malposition (Figure 29-3). This can be avoided by performing a transseptal puncture in the thick septum primum, just below the foramenal open- ing. TEE or ICE guidance is needed to assist with optimal puncture site location. The long sheath is passed through the transseptal puncture site and the device positioned in the transseptal defect, resulting in coverage of the foramen Figure 29-3: Lateral RA angiogram of malposition of a Star- fl ex device in a PFO. Line denotes plane of the septum. Note that the superior right atrial arm (arrow a) and inferior left atrial arm (arrow b) are away from the septum indicating poor position due to a rigid septum primum maintaining the tunnel shape to the PFO. 600 Practical Handbook of Advanced Interventional Cardiology without crossing it. This allows for excellent closure while avoiding device distortion due to the rigid foramenal tun- nel. Post-placement assessment Repeat pressure and saturation measurements in the RA should be performed to assure hemodynamic stability post device. An angiogram at the SVC-RA junction consisting of 24 cc of contrast injected at 24 cc/sec should be performed to confi rm device position and evaluate for residual right to left shunting. The cameras are positioned to evaluate the device in the AP plane (usually 15° RAO and 10° caudal) and on profi le in the lateral plane (75° LAO and 5° caudal). If echo- cardiographic assessment is used then a saline contrast echo shoul d be per fo rmed to evalu ate right to lef t shunt ing. ATRIAL SEPTAL DEFECT Secundum ASDs are one of the more common congeni- tal heart defects, making up 6–10% of all congenital anoma- lies, occurring in 1/1500 live births. 12 Anatomically, secundum ASDs are due to absence, perforation, or defi ciency of the septum primum. This defect typically occurs sporadically but has been linked to genetic abnormalities such as Holt-Oram syndrome and mutations on chromosome 5p. Device closure of an ASD was fi rst performed in 1974 by King and Mills 13,14 using a 24-gauge surgically placed femo- ral sheath and a double-sided disk device. Technology and technique have been modifi ed and refi ned over the years; however, the procedure remains conceptually identical. A col- lapsible double-sided disk device with a metal frame and fabric patches is positioned antegrade through a long femoral sheath across the secundum ASD. Upon extrusion from the sheath the device expands, creating a patch on both sides of the sep- tum clamping the surrounding ASD tissue rim. The endocar- dium grows in to cover the device and create a permanent seal. Because of the need for surrounding rim tissue, device closure is limited to secundum type defects, not applicable to either primum (no inferior posterior rim) or venosus (no superior rim) ASDs. With recent technology, device closure has rapidly be- come the treatment of choice for secundum ASDs. Concurrent controlled trials comparing surgical closure with device closure have shown effi cacy rates of over 96% with signifi cantly lower complications and hospital stay. 6 Most patients can be discharged the day of the procedure with return to full activity within 48–72 hours, signifi cantly reduc- ing costs and medical resources. 15 Early complications have been minor occurring in <9% of patients consisting primar- ily of transient arrhythmias, vascular injury, or asymptomatic device embolization. Serious complications have been quite Percutaneous Interventions in Congenital Heart Diseases 601 rare but include thrombus formation on the device, heart block requiring pacing, and cardiac perforation. 16 Indications: Indications for ASD device closure include any size secundum ASD with evidence on echocardiogram of RV volume overload. Patients with ASD and symptoms of ex- ercise intolerance or history of cryptogenic stroke should also be closed. There is mounting evidence that ASD closure, even in the elderly, can improve maximal oxygen consumption. 17 ASDs have been closed by device in small children including infants; however, the optimal timing for elective closure ap- pears to be between 2 and 4 years of age. Contraindications: There are no absolute contraindica- tions for device ASD closure except for patients with active thrombus in the LA and those with a known allergy to the device implant materials, particularly the nickel in nitinol, an extremely rare condition. Patients who are hypercoagulable, particularly those with disorders that predispose to arterial clots, should be considered very carefully as the post-place- ment risk of clot formation during the endocardialization pro- cess may be signifi cantly increased. Patients with signifi cant left ventricular dysfunction also must be monitored closely after the procedure due to the potential for the development of acute LA hypertension and resultant pulmonary edema. Diuretics immediately post closure may be very helpful in this subgroup of patients. Patients with pulmonary hypertension must be considered carefully but may benefi t as long as there is a baseline lef t to r ight shunt. 18 The procedure: There are currently four devices used recently for ASD closure including: the Amplatzer septal oc- cluder (AGA Medical Corporation, Golden Valleys, MN); the Button device (Custom Medical Devices, Athens, Greece); and the CardioSEAL, STARFlex Helix (Nitinol Medical Technolo- gies, Boston, MA). By far the most commonly used device and the one capable of closing the largest ASDs is the Amplatzer septal occluder. Unlike the others, this device has a central stenting mechanism that expands to the edges of the defect, fi lling it with frame and patch material, improving stability and complete closure rates in large ASDs. It is available in sizes up to 4 cm – capable of closing a 3.8 cm defect. The combined global experience of these devices for ASD closure is well over 30,000 patients with extremely high success and low complica- tion rates. Pre-procedure evaluation/management: A complete omniplane TEE if the patient is an older adolescent or adult, is necessary to defi ne the atrial septal anatomy prior to the pro- cedure. Secundum ASDs are rarely round, so attention to de- fect dimensions in multiple planes is essential for a complete anatomic understanding. Documentation of an adequate atrial septal rim circumferentially (>3 mm, especially at the posterior inferior inlet portion), and evaluation for additional [...]...602 Practical Handbook of Advanced Interventional Cardiology defects, tissue strands, or septal aneurysms with perforations is essential (Figure 2 9-4 A–D) TECHNICAL TIP **Identification of different types of ASD: Identification of all pulmonary veins, particularly the right upper, is essential due to the association of partial anomalous pulmonary venous return with sinous... Practical Handbook of Advanced Interventional Cardiology Figure 2 9-5 : AP and lateral angiogram of a secundum ASD TECHNICAL TIP **Reshaping the tip of the catheter to enter the ASD: Cross the ASD with the Berman catheter by inserting the stiff end of a 0.035" straight wire shaped with a 45° angle at Percutaneous Interventions in Congenital Heart Diseases 605 the distal 3 cm This will give the end of the... diameter 10 10 10 8 Closed diamond Closed diamond Open Closed omega hinges Delivery sheath 16 mm balloon (Fr) Cell design Table 2 9-3 Comparison of large stents used for coarctation and PA stenosis Rigid Poor Good Excellent Flexibility 8 6 4 6 Radial strength 620 Practical Handbook of Advanced Interventional Cardiology Percutaneous Interventions in Congenital Heart Diseases 621 TECHNICAL TIP **A note of caution:... foreshortening with dilation to completely cover the length of the lesion Unnecessary stent length may be a disadvantage due to increased length of non-compliant aorta after implant that may influence blood pressure, particularly in response to exercise 624 Practical Handbook of Advanced Interventional Cardiology TECHNICAL TIP **Advantage of MRI compatible stents: Although not readily available at... placement of additional embolization coils The major complication associated with coil closure of the PDA is coil embolization to the lungs However, this is a technical issue that occurs at or immediately after implant, the incidence of which significantly decreases with operator experience It is related to either undersizing of the coil or malposition upon placement  610 Practical Handbook of Advanced Interventional. .. be problematic and the effectiveness of a post-implant high-pressure dilation is usually significantly greater than the initial implant dilation 626 Practical Handbook of Advanced Interventional Cardiology Post-placement assessment Following balloon dilation or stent implantation, repeat hemodynamic assessment should be performed, including measurement of cardiac index by saturation or thermodilution... retracted to open the distal flange of the device only 616 Practical Handbook of Advanced Interventional Cardiology The entire system is withdrawn together and the aortic flange is pulled firmly against the aortic ampulla A pigtail catheter is positioned from the femoral artery in the thoracic DAO for a lateral angiogram to confirm appropriate position of the aortic end of the device Once position is confirmed... occurs over hours (Figure 2 9-8 ) COARCTATION Coarctation is most often a discrete narrowing of the proximal descending thoracic aorta just distal to the origin of the left subclavian artery at the site of the ductus ligamentum It makes up 7% of all patients with congenital heart disease Percutaneous Interventions in Congenital Heart Diseases 617 Figure 2 9-8 : Lateral angiograms of PDA before, during and... MPN35 Polyester 17–40 10 fabric Guardian Angel Nitinol wire Polyester 18–30 10 fabric Helix Nitinol wire PTFE 15–35 9 PFO Star Nitinol wire Ivalon plug 15–35 10 for defining the arch anatomy and can give functional data including estimation of degree of obstruction based on blood velocity at the site and percent of collateral flow, an excellent indication of the physiologic significance of the coarctation.40... birth by contraction and cellular migration of the medial smooth muscle in the wall of the ductus, resulting in protrusion of the thickened intima into the lumen, causing functional closure Final closure and creation of the ligamentum arteriosum is completed by 3 weeks of age with permanent sealing of the duct by infolding of the endothelium, disruption of the internal elastic lamina, and hemorrhage . 592 Practical Handbook of Advanced Interventional Cardiology **Avoiding entangling the already deployed coil by direc- tional wire **Checking position of device prior to deployment **Closing. pathology, espe- cially an additional ASD or anomalous pulmonary vein). An angiogram is then performed in the low RA with the AP cam- 596 Practical Handbook of Advanced Interventional Cardiology era. Figure 2 9-2 : Lateral angiogram through long sheath in RA showing the LA side of an 18 mm AGA PFO occluder snug against the septum. 598 Practical Handbook of Advanced Interventional Cardiology or