Transcatheter creation of an atrial septal defect using radiofrequency perforation

The Electrified Wire Technique in Complex Aortic Interventions: A Case Series

OBJECTIVES

Electrosurgery has been long used in endovascular procedures, with only case reports in the aortic field. Our aim is to present a case series with the use of an electrified wire to perform catheter-based electrosurgery by applying external current through an electrocautery pen.

METHODS

Single-center retrospective case series of all patients undergoing complex aortic surgery from October 2020 to August 2023, in whom the electrified wire technique was used: (1) Perforation of a dissection flap or left subclavian artery (LSA) in situ endograft fenestration-a 0.014" polytetrafluoroethylene (PTFE) insulated guidewire is detached from the insulation with a scalpel at the end and a cautery pen is here attached with a clamp. A curved tip catheter or sheath is positioned against the aortic flap or the endograft (through a left brachial access in this case) and the wire pushed, crossing the flap by activating the electrocautery pen and (2) slicing a dissection flap ("powered cheese-wire technique")-after same preparation as above, the middle section of the 0.014 guidewire is removed from the PTFE and bent into a V-shape. Once in the aorta, the guidewire crosses from the true lumen (TL) to the false lumen (FL) and a through-and-through access is obtained. Sheaths are positioned against the flap from both sides and moved up or down while the electricity is activated, slicing the flap and communicating both lumens. Technical success and technical-related complications were evaluated.

RESULTS

Eleven cases concerning aortic dissections and 1 case of aortic atresia were treated. Four patients presented urgently, whereas the rest were planned procedures. Seven cases underwent perforation of a dissection flap, 2 cases underwent the powered cheese-wire technique, in 2 cases for an LSA in situ fenestration, and in 1 case to cross an aortic atresia at the aortic isthmus. The technique was in all cases successfully applied. No complications related to the technique occurred.

CONCLUSIONS

The "electrified wire" technique is a feasible and ready-available tool that can be safely used in complex aortic interventions, especially to perforate aortic tissue like dissection flaps or to perform in situ fenestrated repairs by perforation of the endograft fabric.

CLINICAL IMPACT

The electrified wire technique described herein is a straightforward technique that uses readily available tools to perform electrosurgery. We present its use in complex aortic procedures. However, it could be envisioned for any vascular procedure that requires crossing of the vessel or even prosthetic material. As we have described in this series, when used along with an adequate properative planning, it can be a safe tool of great utility, as has already been demonstarted in the field of the interventional cardiology.

Mitral Atresia with Normal Aortic Root

Mitral atresia with normal aortic root is a rare complex congenital heart defect (CHD) and constitute less than 1% of all CHDs. In this anomaly, the mitral valve is atretic, a patent foramen ovale provides egress of the left atrial blood, either a single ventricle or two ventricles with left ventricular hypoplasia are present, and the aortic valve/root are normal by definition. Clinical, roentgenographic and electrocardiographic features are non-distinctive, but echo-Doppler studies are useful in defining the anatomic and pathophysiologic components of this anomaly with rare need for other imaging studies. Treatment consists of addressing the pathophysiology resulting from defect and associated cardiac anomalies at the time of initial presentation, usually in the early infancy. These children eventually require staged total cavo-pulmonary connection (Fontan) in three stages. Discussion of each of these stages were presented. Complications are observed in-between the stages of Fontan surgery and following completion of Fontan procedure. Attempts to monitor for early detection of these complications and promptly addressing the complications are recommended.

Single Ventricle-A Comprehensive Review

In this paper, the author enumerates cardiac defects with a functionally single ventricle, summarizes single ventricle physiology, presents a summary of management strategies to address the single ventricle defects, goes over the steps of staged total cavo-pulmonary connection, cites the prevalence of inter-stage mortality, names the causes of inter-stage mortality, discusses strategies to address the inter-stage mortality, reviews post-Fontan issues, and introduces alternative approaches to Fontan circulation.

Advances in Transcatheter Electrosurgery for Treating Valvular Heart Disease

Delivery of electrosurgery energy through catheters and guidewires enables interventionists to ‘cut’ through obstructive intravascular lesions or across cardiac chambers. A novel application of transcatheter electrosurgery is to make controlled lacerations in heart valve leaflets. This review describes three applications of transcatheter electrosurgery of aortic and mitral valve leaflets to enable transcatheter heart valve implantation. Intentional laceration of the anterior mitral leaflet to prevent left ventricular outflow obstruction splits and splays the anterior mitral valve and enables transcatheter mitral valve replacement without left ventricular outflow tract obstruction. Technique modifications and novel applications are described. Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction enables transcatheter aortic valve replacement without coronary artery obstruction. The technique is described and novel uses, especially in the setting of repeat transcatheter aortic valve replacement, are discussed. Finally, electrosurgical laceration and stabilization of mitral valve clip devices (ELASTA-Clip) enables transcatheter mitral valve replacement after MitraClip implantation. In conclusion, transcatheter electrosurgery is an important and versatile new tool in structural heart intervention.

Preventing Coronary Obstruction During Transcatheter Aortic Valve Replacement: From Computed Tomography to BASILICA

Coronary artery obstruction is an uncommon but devastating complication of transcatheter aortic valve replacement (TAVR). Computed tomography appears to be a sensitive but nonspecific predictor of coronary artery obstruction. Transcatheter approaches to prevent and treat coronary artery obstruction, such as "snorkel" stenting, are unsatisfactory because of serious early and late ischemic complications. Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (BASILICA) is an early-stage transcatheter procedure to prevent coronary artery obstruction. It works by splitting the native or bioprosthetic leaflets so that they splay after TAVR and preserve coronary artery inflow. Because of the paucity of suitable alternatives, there is interest in the BASILICA technique despite its infancy. This tutorial review summarizes current thinking about how to predict and prevent coronary artery obstruction using BASILICA. First, the authors depict the main pathophysiological mechanisms of TAVR-associated coronary artery obstruction, along with the factors thought to contribute to coronary obstruction. Next, the authors provide a step-by-step guide to analyzing pre-procedural computed tomographic findings to assess obstruction risk and, if desirable, to plan BASILICA. Next, the authors describe the mechanisms underlying transcatheter electrosurgery. Finally, they provide step-by-step guidance on how to perform the procedure, along with a required equipment list.

Transcatheter Electrosurgery: JACC State-of-the-Art Review

Transcatheter electrosurgery refers to a family of procedures using radiofrequency energy to vaporize and traverse or lacerate tissue despite flowing blood. The authors review theory, simulations, and benchtop demonstrations of how guidewires, insulation, adjunctive catheters, and dielectric medium interact. For tissue traversal, all but the tip of traversing guidewires is insulated to concentrate current. For leaflet laceration, the "Flying V" configuration concentrates current at the inner lacerating surface of a kinked guidewire. Flooding the field with non-ionic dextrose eliminates alternative current paths. Clinical applications include traversing occlusions (pulmonary atresia, arterial and venous occlusion, and iatrogenic graft occlusion), traversing tissue planes (atrial and ventricular septal puncture, radiofrequency valve repair, transcaval access, Potts and Glenn shunts), and leaflet laceration (BASILICA, LAMPOON, ELASTA-Clip, and others). Tips are provided for optimizing these techniques. Transcatheter electrosurgery already enables a range of novel therapeutic procedures for structural heart disease, and represents a promising advance toward transcatheter surgery.

Transcatheter electrosurgery in bipolar or monopolar modes

Transcatheter electrosurgery has emerging value in a range of other new procedures that require traversing tissue (transcaval access, transcatheter Glenn Shunt) or slicing tissue (LAMPOON slicing of the mitral valve and BASILICA slicing of the aortic valve). This is the first report of bipolar radiofrequency wires used to cross lesions in humans, reported here in seven re-entry CTO cases. The bipolar configuration may provide directionality to charge without need for wire alignment and advancement, but is theoretically disadvantageous for tissue "cutting" because of problems with charge concentration.

Guidewire electrosurgery-assisted trans-septal puncture

OBJECTIVES

Electrifying a coronary guidewire may be a simple escalation strategy when trans-septal needle puncture is unsuccessful.

BACKGROUND

Radiofrequency energy to facilitate trans-septal puncture through a dedicated device is costly and directly through a trans-septal needle may be less safe. Our technique overcomes these limitations.

METHODS

The technique was used in patients when trans-septal needle penetration failed despite excessive force or tenting of the atrial septum. A coronary guidewire, connected to an electrosurgery pencil, was advanced through the trans-septal needle, dilator, and sheath to perforate the interatrial septum during a short burst of radiofrequency energy. With the guidewire tip no longer "active," the dilator and sheath were advanced safely over the wire into the left atrium. In posthoc validation, radiofrequency assisted Brockenbrough needle and coronary guidewire punctures were made in freshly explanted pig hearts and compared under microscopy.

RESULTS

Eight patients who required trans-septal access for structural intervention were escalated to a guidewire electrosurgery strategy. Six patients had thickened fibrotic septum and two had prior surgical patch repair. Crossing was successful in all patients with no procedure related complications. The size of punctures (1.11 ± 0.40 mm vs 0.37 ± 0.08 mm, P = .009) and blanched penumbra (3.62 ± 1.23 mm vs 0.72 ± 0.29 mm, P = .003) in pig atrial septum were larger with an electrified needle than electrified guidewire. The hole generated by the electrified guidewire was smaller than by the nonelectrified needle.

CONCLUSIONS

When conventional trans-septal puncture fails, a coronary guidewire can be used to deliver brief radiofrequency energy safely and effectively. This technique is inexpensive and accessible to operators.

Transseptal puncture using surgical electrocautery in children and adults with and without complex congenital heart disease

BACKGROUND

Atrial transseptal puncture (TSP) for cardiac catheterization procedures remain challenging in children and adults with complex congenital heart disease (CHD).

OBJECTIVES

We sought to evaluate our experience using radiofrequency (RF) current via surgical electrocautery needle for TSP to facilitate diagnostic and interventional procedures.

METHODS

Retrospective chart review of all patients (pts) who underwent TSP using RF energy (10-25 W) via surgical electrocautery from three centers from January 2011 to January 2017 were evaluated. Echocardiograms were reviewed to define the atrial septum as normal and complex (thin aneurysmal, thick/fibrotic, synthetic patch material, and extra cardiac conduit).

RESULTS

A total of 54 pts underwent 55 successful TSP. Median age was 12.5 years (1 day-54 years) and weight was 52.7 kg (2-162). Indications for TSP included; EP study and ablation procedures in structurally normal hearts (n = 24) and in complex atrial septum/CHD and structural heart disease pts (n = 30): Electrophysiology study and ablation in 4, diagnostic catheterization in 9, and interventional procedures in 17 pts were performed. Atrial TSP was successful in 54/55 (98%). Atrial perforation with tiny-small pericardial effusion not requiring intervention was noted in 2 pts. TSP was unsuccessful in one critically ill neonate with unobstructed TAPVR and restricted atrial septum who experienced cardiac arrest requiring CPR, ECMO, and emergent surgery.

CONCLUSIONS

RF current delivery using surgical electrocautery for TSP is a feasible and an effective option in patients with complex CHD for diagnostic, interventional, and electrophysiology procedures.

Wire Atrial Septostomy: A New Technique to Create a Large Defect in a Thickened Atrial Septum

Both balloon atrial septostomy and static balloon dilation are often ineffective in creating a large atrial septal defect in patients with a thickened atrial septum. In such situations, blade atrial septostomy and atrial septal stenting are alternative treatments. We have devised and performed a new technique, called wire atrial septostomy, which uses a thin soft wire to create a large defect. The details of the procedure are presented.

Management of hypoplastic left heart syndrome with intact atrial septum: a two-centre experience

Introduction Hypoplastic left heart syndrome with an intact atrial septum is a poor predictor of outcomes. Prenatal assessment of pulmonary venous Doppler and emergent postnatal cardiac intervention may be associated with better outcomes. Materials and methods A retrospective review of all hypoplastic left heart syndrome patients in two centres over a 5-year period was performed. Group 1 included patients with adequate inter-atrial communication. Group 2 included patients with prenatal diagnosis with an intact atrial septum who had immediate transcatheter intervention. Group 3 included patients with intact atrial septum who were not prenatally diagnosed and underwent either delayed intervention or no intervention before stage 1 palliation. Primary outcome was survival up to stage 2 palliation.

RESULTS

The incidence of hypoplastic left heart syndrome with a restrictive atrial communication was 11.2% (n=19 of 170). Overall survival to stage 2 or heart transplantation was 85% and 67% for Groups 1 and 2, respectively (n=129/151, n=8/12; p=0.03), and 0% (n=0/7) for Group 3. Survival benefits were observed between Groups 2 and 3 (p<0.001). Foetal pulmonary vein Doppler reverse/forward velocity time integral ratio of ⩾18% (sensitivity, 0.99, 95% CI, 0.58-1; specificity, 0.99, 95% CI, 0.96-1) was predictive of the need for emergent left atrial decompression.

CONCLUSION

Using a multidisciplinary approach and foetal pulmonary vein Doppler, time-saving measures can be instituted by delivering prenatally diagnosed neonates with hypoplastic left heart syndrome with intact atrial septum close to the cardiac catheterisation suite where left atrial decompression can be performed quickly and safely that may improve survival.

A simple and fast technique for radiofrequency-assisted perforation of the atrial septum in congenital heart disease

Radiofrequency (RF) assisted perforation of the atrial septum was performed successfully in three infants using a 0.035” RF wire deployed through a Williams right posterior catheter. Balloon atrial septoplasty was performed over the 0.035” RF wire in two of them, shortening the procedural time.

NRG™ RF powered transseptal needle: a useful technique for transcatheter atrial septostomy and Fontan fenestration: report of three cases

Transseptal puncture (TSP) is a frequently performed procedure for gaining access to the left atrium for catheter ablation, hemodynamic assessment of the left heart, left ventricular assist device implantation, percutaneous left atrial appendage closure or mitral valvuloplasty during childhood and adulthood. The standard technique for transseptal puncture applies mechanical pressure on the fossa ovalis with a Brockenbrough needle. However, this method is not feasible when the fossa ovalis is thick and aneurysmatic. In such patients, the radiofrequency ablation energy systems can be offered as a better alternative for TSP. Here, we aimed to demonstrate the outcome of transseptal puncture performed with an NRG™ RF powered transseptal needle in three patients.

Radiofrequency applications in congenital heart disease

The relatively recent application of radiofrequency technologies in the treatment of congenital heart defects has provided a safe and effective alternative to conventional therapies in establishing endovascular patency for a variety of lesions. Radiofrequency, with typically used frequencies of approximately 500 kHz, does not cause pain and is unlikely to induce atrial or ventricular fibrillation. It can be used either to ablate (higher power (35-50 W); longer duration of application (90-120 sec); lower voltage (30-50 V)) or to perforate (lower power (5-10 W) shorter duration of application (1-5 sec), higher voltage (150-280 V)). In the past, perforating radiofrequency has been applied to establish right ventricular outflow tract patency in pulmonary atresia with intact septum and with ventricular septal defect. More recently radiofrequency has been shown to be effective at recanalizing central and peripheral vasculature and has also been applied in establishing percutaneous left heart access. A new radiofrequency catheter, dedicated to transseptal left atrial cannulation, has been demonstrated to be safe and effective in an animal model and is now ready for clinical trials.

Transbaffle mapping and ablation for atrial tachycardias after mustard, senning, or Fontan operations

Background

In Fontan and atrial switch patients, transcatheter ablation is limited by difficult access to the pulmonary venous atrium. In recent years, transbaffle access (TBA) has been described, but limited data document its safety and utility.

Methods and Results

All ablative electrophysiological study cases of this population performed between January 2006 and December 2010 at Boston Children's Hospital were reviewed. Pre‐case and follow‐up clinical characteristics were documented. Adverse events were classified by severity and attributability to the intervention. We included 118 cases performed in 90 patients. TBA was attempted in 74 cases and was successful in 96%: in 20 via baffle leak or fenestration and in 51 (94%) of 54 using standard or radiofrequency transseptal techniques. There were 10 procedures with adverse events ranked as moderate or more severe. The event rate was similar in both groups (TBA 8% versus non‐TBA 9%, P=1), and no events were directly attributable to TBA. There was a trend to higher proportion of cases having a >5‐point drop in saturations from baseline in the TBA group versus the non‐TBA group in Fontan cases (15% vs 0%, P=0.14). When cases with follow‐up >90 and >365 days were analyzed, the median initial arrhythmia score of 5 significantly changed −3 points in both time periods (P≤0.001).

Conclusions

TBA is feasible in this population; its use was not associated with a higher incidence of adverse events; and changes in clinical scores support its efficacy. Desaturation observed in some patients is of uncertain significance but warrants postablation monitoring and prospective study.

Recanalization of systemic venous baffles by radiofrequency perforation and stent implantation

Complete transposition of the great arteries has been historically managed by the Mustard (atrial switch) operation. This procedure is associated with longterm complications such as baffle occlusion, which also precludes the insertion of a permanent transvenous pacemaker. Transcatheter techniques have allowed the successful angioplasty and stenting of stenotic baffles but complete occlusions continue to pose a therapeutic challenge. We report the use of a novel technique, a radiofrequency perforation wire for the management of complete occlusion of systemic venous baffles post-Mustard operation.

New transcatheter techniques for creation or enlargement of atrial septal defects in infants with complex congenital heart disease

OBJECTIVES

To describe a series of 8 consecutive infants (5 with transposition of the great arteries [TGA] and 3 with hypoplastic left heart syndrome [HLHS]) who underwent nonconventional septostomy techniques.

BACKGROUND

For some complex congenital heart defects, an unrestrictive atrial septal defect (ASD) is essential to achieve an adequate cardiac output and/or systemic saturation. In some scenarios, the use of conventional septostomy techniques may be technically difficult, hazardous, and/or ineffective.

METHODS

Use of transhepatic approach, cutting balloons, and radiofrequency perforation with stenting of the atrial septum.

RESULTS

The size of the ASD and the oxygen saturation increased in all patients with no major complications. In those with TGA, the ASDs were considered to be of good size at the arterial switch operation. Two of the 3 patients with hybrid palliation for HLHS have developed some degree of obstruction within the interatrial stent over 2-3 months. At surgery, the stents were found to be secured within the septum with one showing significant fibrous ingrowth after uneventful removal. The other had some nonobstructive ingrowth.

CONCLUSIONS

Creation or enlargement of ASDs in infants using new nonconventional transcatheter techniques is feasible, safe, and effective, at least in the short-to-mid-term follow-up. Infants with TGA seem to benefit the most because the procedure results in satisfactory clinical stability for subsequent early surgical intervention. In infants with HLHS palliated by a hybrid approach, stent implantation to the atrial septum seems to buy enough time to bring them to the phase II safely despite progressive in-stent obstruction.

Successful Recanalization of a Longstanding Complete Left Subclavian Vein Occlusion by Radiofrequency Perforation with Use of a Radiofrequency Guide Wire

Treatment with radiofrequency (RF) energy can be used to ablate or perforate tissues. The latter involves lower power, higher voltage, and much shorter treatment time, and it is thought to induce much less collateral tissue damage. To date, RF perforation has been successfully used for various cardiac interventions; however, to our knowledge, there has not been a report of its use for peripheral vascular disease. This report describes the successful recanalization of a longstanding occlusion of a left subclavian vein in a 73-year-old woman with polycystic kidney disease and end-stage renal disease undergoing chronic hemodialysis treatment via an upper-extremity arteriovenous fistula. Multiple previous attempts at mechanical recanalization were unsuccessful. Recanalization was achieved by RF perforation with use of a PowerWire RF guide wire.

Hypoplastic left heart syndrome with intact atrial septum

In patients with hypoplastic left heart syndrome (HLHS) and intact atrial septum, the blood entering the left atrium cannot egress. Emergency treatment interventionally or surgically is mandatory immediately after birth. We describe a patient with HLHS and intact atrial septum who underwent successful transvenous atrial septostomy immediately after birth. When the interatrial communication became restrictive, stent implantation into the arterial duct and into the atrial septum was performed on the 7th day of life. Despite good hemodymanic response, the lung damage was severe and persistent, rendering staged surgical correction impossible. The child died on the 23rd day of life. Autopsy showed patent and correct placed stents in the duct and the atrial septum. There was severe dilatation of pulmonary lymphatic and venous vessels, suggestive of long-standing pulmonary venous hypertension. In conclusion, this form of HLHS has a poor prognosis despite early and aggressive interventional treatment.

Resolution of protein-losing enteropathy after radiofrequency perforation and subsequent stent implantation for relief of complete occlusion of a redirected left superior vena cava

The application of radiofrequency (RF) technologies in the treatment of congenital heart defects has provided a safe and effective alternative to conventional therapies in the restoration of vascular patency for a variety of arterial and venous occlusions. This report concerns an 8-year old girl that developed protein-losing enteropathy and elevated central venous pressure after occlusion of a surgically redirected anomalous draining left superior vena cava (SVC). Cardiac catheterization revealed complete obstruction of the anastomosis of the SVC into the coronary sinus. Transcatheter recanalization by RF perforation and subsequent stent implantation led to the restoration of upper venous blood flow and the resolution of her symptoms.

Radiofrequency perforation and cutting balloon septoplasty of intact atrial septum in a newborn with hypoplastic left heart syndrome using transesophageal ICE probe guidance

Newborns with hypoplastic left heart syndrome and intact atrial septum present an emergent and unique challenge to a children's heart center. This case report describes new transcatheter techniques (use of radiofrequency energy to perforate the atrial septum followed by cutting balloon and static balloon septoplasty) and novel use of a transesophageal ICE probe.

Transcatheter creation of atrial septal perforation using a radiofrequency transseptal system: Novel approach as an alternative to transseptal needle puncture

Indications for the transseptal approach to the left side of the heart have recently broadened, as it provides a therapeutic access for both left-sided catheter ablation and also percutaneous transvenous valvular intervention. Despite rising demand for transseptal procedures, the technique and device used for this purpose have remained essentially unchanged over the past 4 decades. The possibilities of failure of puncturing distorted and thickened atrial septal tissue or risks of complications related to cardiac perforation remain limitations of the technique. A new radiofrequency catheter provides an alternative approach to create a controlled transseptal perforation. We applied this technique to a series of patients and evaluated its feasibility as an alternative to conventional transseptal needle puncture.

Novel approach to the newborn with hypoplastic left heart syndrome and intact atrial septum

A prenatally diagnosed fetus with hypoplastic left heart syndrome and intact atrial septum was delivered in the cardiac catheterization suite. Using radio frequency energy, a transseptal perforation of the thickened and intact atrial septum was immediately performed following transcatheter cannulation of the right atrium via the umbilical vein. Serial cutting balloon septostomies followed by static balloon septostomies resulted in effective left atrial decompression, atrial mixing, and optimal pulmonary and systemic perfusion. The child is now thriving after both stage I Norwood and bidirectional Glenn procedures.

Radiofrequency perforation and conventional needle percutaneous transseptal left heart access: Pathological features

Perforating radiofrequency (PRF) energy has been used to obtain percutaneous transseptal left heart access. Contrary to ablative radiofrequency (RF), myocardial tissue responses to PRF thermal injury are incompletely defined. In this study, a newly developed RF catheter system for transseptal left atrial entry was compared with conventional needle puncture. Of 15 piglets having transfemoral cardiac catheterization, 12 had transseptal procedures. Needle punctures (NP) and PRF were followed by acute (1 hr; 3 NP, 3 PRF) and chronic necropsy (1 month; 3 NP, 3 PRF). The remaining three piglets had intentional RF aortic perforation through the atrial roof with necropsy at 1 month. Gross and histopathological effects were examined. Acutely, the gross RF lesion was similar to needle puncture. Histologically, the RF lesions had minimal mural thrombus, an inner zone of thermal injury characterized by grayish cytoplasmic staining (elastic trichrome), and a bubbly transformation of the cytoplasm in innermost cardiomyocytes, partial persistence of cross-striations, and an acute inflammatory reaction. The outer extent of the lesion (< 1 mm) was defined by a halo of contraction band necrosis similar to needle puncture. Acute NP injury showed comparable depth and extent of myocyte necrosis (principally contraction bands) with adjacent tissue hemorrhage and edema. At 1 month, a well-developed densely collagenous scar was present in both aortic and transseptal PRF lesions. The extent of acute RF injury is similar to that seen in conventional NP, but the characteristics of tissue insult are different. Both show well-developed healing at 1 month.

Radiofrequency perforation in the treatment of acquired left pulmonary artery atresia following repair of tetralogy of Fallot

Acquired pulmonary artery discontinuity can complicate operative repair of certain congenital heart defects. We describe successful recanalization of acquired left pulmonary artery atresia using radiofrequency energy in a 14-month-old child who had previously undergone repair of tetralogy of Fallot with pulmonary atresia.

Recanalization of a discrete atretic right pulmonary artery segment with a new radiofrequency system

We describe a case in which a discrete atretic segment of the right pulmonary artery (due to a Blalock-Taussig shunt) was reconstructed using a new radiofrequency system, balloon dilation, and stent implantation in an 18-month-old patient. The shunt was coil-occluded. The technique and applications of this novel approach are discussed.

Future of interventional cardiology in pediatrics

A trend toward use of less invasive, nonsurgical approaches to the treatment of congenital heart disease has developed. Although transcatheter valve replacements and ventricular septal defect closures have already been performed in children, many other techniques and devices are being developed for the palliation of children with a single ventricle. Several groups have already established catheter-based procedures for the creation of Fontan communications, and others have performed nonsurgical pulmonary artery banding. Additionally, fetal catheter-based interventions are being developed for the treatment of severe congenital heart disease in utero. Because this trend toward catheter-mediated treatment is certain to continue, care must be taken to regulate safely the introduction of novel techniques and devices into clinical use in pediatric cardiology.

Radiofrequency perforation in the treatment of congenital heart disease

Catheter-directed perforation of cardiac tissue with radiofrequency (RF) energy has expanded the horizon of the interventional cardiologist dealing with congenital heart disorders. The focus of the following discussion will be to detail the biophysical basis behind RF perforation and review its application in the management of congenital heart lesions.