Radiofrequency-assisted balloon dilatation in patients with pulmonary valve atresia and an intact ventricular septum

Radiofrequency Perforation of an Atretic Pulmonary Valve with a Modified Coronary Wire and Electrocautery Pencil

Radiofrequency (RF) perforation of an atretic pulmonary valve is commonly performed in patients with pulmonary atresia with intact ventricular septum with specifically designed RF wires. In difficult anatomy or low-resource centers, this may instead be successfully performed with a modified coronary guide wire and an electrocautery surgical pencil.

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.

Current status of transcatheter intervention for complex right ventricular outflow tract abnormalities

Various transcatheter interventions for the right ventricular outflow tract (RVOT) have been introduced and developed in recent decades. Transcatheter pulmonary valve perforation was first introduced in the 1990s. Radiofrequency wire perforation has been the approach of choice for membranous pulmonary atresia in newborns, with high success rates, although complication rates remain relatively common. Stenting of the RVOT is a novel palliative treatment that may improve hemodynamics in neonatal patients with reduced pulmonary blood flow and RVOT obstruction. Whether this option is superior to other surgical palliative strategies or early primary repair of tetralogy of Fallot remains unclear. Transcatheter pulmonary valve replacement has been one of the biggest innovations in the last two decades. With the success of the Melody and SAPIEN valves, this technique has evolved into the gold standard therapy for RVOT abnormalities with excellent procedural safety and efficacy. Challenges remain in managing the wide heterogeneity of postoperative lesions seen in RVOT, and various technical modifications, such as pre-stenting, valve ring modification, or development of self-expanding systems, have been made. Recent large studies have revealed outcomes comparable to those of surgery, with less morbidity. Further experience and multicenter studies and registries to compare the outcomes of various strategies are necessary, with the ultimate goal of a single-step, minimally invasive approach offering the best longer-term anatomical and physiological results.

Transcatheter Electrosurgery: A Narrative Review

Transcatheter electrosurgery describes the ability to cut and traverse tissue, at a distance, without an open surgical field and is possible using either purpose-built or off-the-shelf devices. Tissue traversal requires focused delivery of radiofrequency energy to a guidewire tip. Initially employed to cross atretic pulmonary valves, tissue traversal has enabled transcaval aortic access, recanalization of arterial and venous occlusions, transseptal access, and many other techniques. To cut tissue, the selectively denuded inner curvature of a kinked guidewire (the Flying-V) or a single-loop snare is energized during traction. Adjunctive techniques may complement or enable contemporary transcatheter procedures, whereas myocardial slicing or excision of ectopic masses may offer definitive therapy. In this contemporary review we discuss the principles of transcatheter electrosurgery, and through exemplary clinical applications highlight the range of therapeutic options offered by this versatile family of procedures.

Use of Electrosurgery in Interventional Cardiology

Transcatheter electrosurgery is a versatile tool that can be used to cut cardiac tissue without the need for a sternotomy, cardiopulmonary bypass, and cardioplegia. With adequate imaging and suitable anatomy, any cardiac tissue can be cut. Thus, transcatheter electrosurgery can provide bespoke therapies for complex patients who often have no other good treatment options. In this review, we will discuss the common applications for electrosurgical tissue traversal and laceration, including transcaval access, BASILICA, LAMPOON, and ELASTA-Clip, summarizing the evidence and the key technical steps for each.

Retrograde Pulmonary Vein Recanalization Using Transcatheter Electrosurgery

Transcatheter electrosurgery is a wire-based technique used to traverse or cut tissue within blood-filled spaces using alternating current delivered by guidewires or catheters. The use of transcatheter electrosurgical techniques in the pediatric population has been limited. We are reporting the first case of retrograde pulmonary vein recanalization using transcatheter electrosurgery. (Level of Difficulty: Advanced.)

The Use of Chronic Total Occlusion (CTO) Wires for Perforation of Atretic Pulmonary Valve; Two Centers Experience

Pulmonary valve atresia with intact ventricular septum (PA-IVS) can be treated either surgically or transcatheterly for eligible patients. Perforation of pulmonary valves using chronic total occlusion (CTO) guidewires has been reported as an alternative to radiofrequency (RF) perforation. We sought to report our experience with CTO guidewires for perforation of atretic pulmonary valves and subsequent balloon dilatation (with or without patent ductus arteriosus stenting) in patients with PA-IVS from two centers. A retrospective study was carried out on PA-IVS patients who underwent intervention between March 2014 and September 2019, in which CTO guidewire was employed for pulmonary valve perforation. A total of 26 patients were identified. The median age and weight of the patients were 5.2 days (range 1-21 days) and 3.1 kg (range 2.2-3.8 kg), respectively. All patients were situs solitus, except one patient with left atrial isomerism. The right ventricle (RV) morphology was bipartite in 22/26 patients and tripartite in 4/26 patients. Before the procedure, the mean saturation was 76% (range 70-86%) while the patients were under prostaglandin infusion. The pulmonary valve perforation attempt was performed with the Asahi Conquest Pro 9 CTO wire (n = 6) or Asahi Pro 12 CTO wire (n = 18) and/or Asahi Miracle CTO wire (n = 2). The procedure was successful in 20/26 (77%) patients using CTO wires. We analyzed the efficiency of CTO wire based on the subtypes: Conquest Pro 9 in 6/6 (100%) patients, Conquest Pro 12 in 12/18 (67%) patients, and Miracle in 2/2 (100%) patients. Before CTO wire usage in 3 patients, radiofrequency (RF) perforation was unsuccessful. Among these 3 patients, pulmonary valve perforation was successful in 2 patients with CTO wire; hence, in the remaining patient, perforation was also unsuccessful with CTO wire. After CTO wire perforation was unsuccessful in 6 patients, RF perforation was attempted in 3 patients (2 successful attempts and 1 unsuccessful attempts), and one patient as referred to surgery. Desaturation was persistent in 19 cases, which necessitated ductus arteriosus stenting. Early procedural complication was observed in 3/26 (11%) patients. Two of these patients had vascular complications due to the sheath, which was treated with heparin infusion and streptokinase, and the remaining patient had sudden bradycardia and cardiac arrest during the procedure and did not respond to cardiac resuscitation. CTO wires should be keep in mind for atretic pulmonary valve perforation as a first choice or when RF perforation is unsuccessful.

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.

Is there a transcatheter solution for a sick neonate with hypoplastic right heart syndrome?: Pulmonary valve perforation in a neonate with hypoplastic right ventricle with pulmonary atresia, restrictive VSD-a case report

BACKGROUND

Hypoplastic right heart syndrome with pulmonary atresia is a rare cyanotic heart disease with poor prognosis requiring urgent intervention to establish the pulmonary blood flow. Pulmonary blood flow is achieved by BT shunt or percutaneous techniques like PDA stenting or pulmonary valve perforation. Various series have shown that early surgical intervention causes high mortality in these patients. Pulmonary valve perforation is a suitable, physiological alternative to surgical techniques in selected patients.

CASE PRESENTATION

We report a case of hypoplastic right heart syndrome with pulmonary atresia and restrictive VSD presenting with cyanosis from birth and underwent pulmonary valve perforation successfully.

CONCLUSION

Duct-dependent pulmonary circulation is a pediatric emergency, palliative procedure for establishing adequate pulmonary blood flow is essential early in the life. In the management of duct-dependent pulmonary circulation, RVOT perforation is an effective and safe option in suitable high-risk subgroups. The induced pulmonary regurgitation along with established physiological antegrade flow would be beneficial in the remodeling of tripartite/hypertrophied small RV.

A low threshold for neonatal intervention yields a high rate of biventricular outcomes in pulmonary atresia with intact ventricular septum

AIMS

Management strategies for pulmonary atresia with intact ventricular septum are variable and are based on right ventricular morphology and associated abnormalities. Catheter perforation of the pulmonary valve provides an alternative strategy to surgery in the neonatal period. We sought to assess the long-term outcome in terms of survival, re-intervention, and functional ventricular outcome in the setting of a 26-year single-centre experience of low threshold inclusion criteria for percutaneous valvotomy.

METHODS AND RESULTS

Retrospective analysis of patients diagnosed with pulmonary atresia with intact ventricular septum from 1990 to 2016 at a tertiary referral centre, was performed. Of 71 patients, 48 were brought to the catheterisation laboratory for intervention. Catheter valvotomy was successful in 45 patients (94%). Twenty-three patients (51%) also underwent ductus arteriosus stenting. The length of intensive care and hospital stay was significantly shorter, and early re-interventions were significantly reduced in the catheterisation group. There were eight deaths (17%); all within 35 days of the procedure. Of the survivors, only one has required a Fontan circulation. Twenty-eight patients (74%) have undergone biventricular repair and nine patients (24%) have one-and-a-half ventricle circulation. Following successful valvotomy, 80% of patients required further catheter-based or surgical interventions.

CONCLUSIONS

A low threshold for initial interventional management yielded a high rate of successful biventricular circulations. Although mortality was low in patients who survived the peri-procedural period, the rate of re-intervention remained high in all groups.

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.

Fifty-Five Years Follow-Up of 111 Adult Survivors After Biventricular Repair of PAIVS and PS

There is paucity of long-term data on adult survivors after biventricular repair of pulmonary atresia with intact ventricular septum (PAIVS) and pulmonary stenosis (PS). This study aimed to determine the cardiac and non-cardiac outcomes of adult survivors after biventricular repair of PAIVS and PS. The cardiac, neurodevelopmental and liver problems of 111 adults, 40 with PAIVS and 71 with PS, were reviewed. The median follow-up duration of our patients was 26.5 years (range 14.8-55 years). The freedom from reintervention at 30 years was 17.4% and 73.3% for PAIVS and PS patients (p < 0.001), respectively. Compared with PS patients, PAIVS patients had significantly greater prevalence of right atrial and right ventricular (RV) dilatation, and moderate to severe tricuspid and pulmonary regurgitation (all p < 0.05), and cardiac arrhythmias (22.5% vs. 8.5%, p = 0.047). The freedom from development of cardiac arrhythmias at 30 years of 68.4% and 91.6%, respectively, in PAIVS and PS patients (p = 0.03). Cox proportional hazards model identified PAIVS as an independent risk factor for reintervention (HR 4.0, 95% CI 2.1-7.6, p < 0.001) and development of arrhythmias (HR 4.1, 95% CI 1.1-14.4, p = 0.03). Neurodevelopmental problems were found in 17.5% of PAIVS patients and 7.0% of PS patients (p = 0.11). Liver problems occurred in 2 (5%) PAIVS patients, both of whom required conversion to 1.5 ventricular repair. In conclusion, long-term problems, including the need for reinterventions, cardiac arrhythmias, RV dilation, pulmonary regurgitation, and neurodevelopmental and liver issues are more prevalent in adult PAIVS than PS survivors.

Technical factors are associated with complications and repeat intervention in neonates undergoing transcatheter right ventricular decompression for pulmonary atresia and intact ventricular septum: results from the congenital catheterisation research collaborative

BACKGROUND

Transcatheter right ventricle decompression in neonates with pulmonary atresia and intact ventricular septum is technically challenging, with risk of cardiac perforation and death. Further, despite successful right ventricle decompression, re-intervention on the pulmonary valve is common. The association between technical factors during right ventricle decompression and the risks of complications and re-intervention are not well described.

METHODS

This is a multicentre retrospective study among the participating centres of the Congenital Catheterization Research Collaborative. Between 2005 and 2015, all neonates with pulmonary atresia and intact ventricular septum and attempted transcatheter right ventricle decompression were included. Technical factors evaluated included the use and characteristics of radiofrequency energy, maximal balloon-to-pulmonary valve annulus ratio, infundibular diameter, and right ventricle systolic pressure pre- and post-valvuloplasty (BPV). The primary end point was cardiac perforation or death; the secondary end point was re-intervention.

RESULTS

A total of 99 neonates underwent transcatheter right ventricle decompression at a median of 3 days (IQR 2-5) of age, including 63 patients by radiofrequency and 32 by wire perforation of the pulmonary valve. There were 32 complications including 10 (10.5%) cardiac perforations, of which two resulted in death. Cardiac perforation was associated with the use of radiofrequency (p=0.047), longer radiofrequency duration (3.5 versus 2.0 seconds, p=0.02), and higher maximal radiofrequency energy (7.5 versus 5.0 J, p<0.01) but not with patient weight (p=0.09), pulmonary valve diameter (p=0.23), or infundibular diameter (p=0.57). Re-intervention was performed in 36 patients and was associated with higher post-intervention right ventricle pressure (median 60 versus 50 mmHg, p=0.041) and residual valve gradient (median 15 versus 10 mmHg, p=0.046), but not with balloon-to-pulmonary valve annulus ratio, atmospheric pressure used during BPV, or the presence of a residual balloon waist during BPV. Re-intervention was not associated with any right ventricle anatomic characteristics, including pulmonary valve diameter.

CONCLUSION

Technical factors surrounding transcatheter right ventricle decompression in pulmonary atresia and intact ventricular septum influence the risk of procedural complications but not the risk of future re-intervention. Cardiac perforation is associated with the use of radiofrequency energy, as well as radiofrequency application characteristics. Re-intervention after right ventricle decompression for pulmonary atresia and intact ventricular septum is common and relates to haemodynamic measures surrounding initial BPV.

Radiofrequency perforation of the pulmonary valve: an efficient low cost solution

Objective The aim of the study was to assess the feasibility of using commonly available catheterization laboratory equipment for radiofrequency perforation of the pulmonary valve in patients with pulmonary atresia and intact ventricular septum. Methods The system (off-label use for all items) is made up of a co-axial telescopic arrangement consisting of a 0.014" PT 2 ™ coronary guidewire, for insulation inside a 2.7-F microcatheter which has an inner lumen of 0.021". The microcatheter was passed via a standard 4-F right coronary catheter to just below the atretic pulmonary valve. Radiofrequency (RF) energy was delivered using a standard electrosurgical system. In vitro testing had been performed and indicated that 5-10 W for 2-5 s would be sufficient for valve perforation. Results Radiofrequency perforation was successfully performed in all (n = 5, 100%) patients at a median age of 3 days (range: 1-36) and weight 2.7 kg (range 2.3-3.0). In one patient the pericardium was entered during the initial attempt; the generator was put on coagulation mode during retrieval of the guidewire and no haemopericardium occurred. The pulmonary valve was dilated in all; in three patients (n = 3) the ductus arteriosus was stented during the same session. Conclusion Results of the study show that it is feasible to perforate the pulmonary valve safely using this system. Availability, simplicity and cost are noteworthy benefits.

Intentional Percutaneous Laceration of the Anterior Mitral Leaflet to Prevent Outflow Obstruction During Transcatheter Mitral Valve Replacement: First-in-Human Experience

OBJECTIVES

This study sought to use a new catheter technique to split the anterior mitral valve leaflet (AML) and prevent iatrogenic left ventricular outflow tract (LVOT) obstruction immediately before transcatheter mitral valve replacement (TMVR).

BACKGROUND

LVOT obstruction is a life-threatening complication of TMVR, caused by septal displacement of the AML.

METHODS

The procedure was used in patients with severe mitral valve disease and prohibitive surgical risk. Patients either had prior surgical mitral valve ring (n = 3) or band annuloplasty (n = 1) or mitral annular calcification with stenosis (n = 1). Iatrogenic LVOT obstruction or transcatheter heart valve dysfunction was predicted in all based on echocardiography and computed tomography. Transfemoral coronary guiding catheters directed an electrified guidewire across the center and base of the AML toward a snare in the left atrium. The externalized guidewire loop was then electrified to lacerate the AML along the centerline from base to tip, sparing chordae, immediately before transseptal TMVR.

RESULTS

Five patients with prohibitive risk of LVOT obstruction or transcatheter heart valve dysfunction from TMVR successfully underwent LAMPOON, with longitudinal splitting of the A2 scallop of the AML, before valve implantation. Multiplane computed tomography modeling predicted hemodynamic collapse from TMVR assuming an intact AML. However, critical LVOT gradients were not seen following LAMPOON and TMVR. Doppler blood flow was seen across transcatheter heart valve struts that encroached the LVOT, because the AML was split. Transcatheter heart valve function was unimpeded.

CONCLUSIONS

This novel catheter technique, which resembles surgical chord-sparing AML resection, may enable TMVR in patients with prohibitive risk of LVOT obstruction or transcatheter heart valve dysfunction.

Transcatheter pulmonary valve perforation using chronic total occlusion wire in pulmonary atresia with intact ventricular septum

Background:

Perforation of pulmonary valve using radiofrequency ablation in pulmonary atresia with intact ventricular septum (PA IVS) is a treatment of choice. However, significant cost of the equipment limits its utility, especially in the developing economies.

Objective:

To assess the feasibility, safety, and efficacy of perforation of pulmonary valve using chronic total occlusion (CTO) wires in patients with PA IVS as an alternative to radiofrequency ablation.

Methods:

This is a single-center, nonrandomized, retrospective study conducted during June 2008 to September 2015. Twenty-four patients with PA IVS were selected for the procedure during the study period. The median age and weight of the study population were 8. days and 2.65 kg, respectively. Four patients were excluded after right ventricular angiogram as they showed right ventricular-dependent coronary circulation. The pulmonary valve perforation was attempted using various types of CTO wires based on the tip load with variable penetrating characteristics.

Results:

The procedure was successful in 16 of twenty patients using CTO wires: Shinobi in nine, Miracle in four, CROSS-IT in two, and Conquest Pro in one. Two patients had perforation of right ventricular outflow tract (RVOT). Pericardiocentesis was required in one patient to relieve cardiac tamponade. Later, the same patient underwent successful hybrid pulmonary valvotomy. The other patient underwent ductus arteriosus (DA) stenting. Balloon atrial septostomy was needed in three cases with systemic venous congestion. Desaturation was persistent in five cases necessitating DA or RVOT stenting to augment pulmonary blood flow. There were two early and two late deaths. The mean follow-up was 22.66 ± 16 months. Three patients underwent one and half ventricle repair and one Blalock–Taussig shunt during follow-up.

Conclusion:

Perforation of the pulmonary valve can be done successfully using CTO wires in selected cases of pulmonary atresia with intact ventricular septum.

[Interventional cardiac catheterization in congenital heart disease]

Interventional cardiac catheterization has a major place in the management of congenital heart disease. Since the Rashkind atrioseptostomy in mid-1960s, many techniques have been developed. For some, it is necessary to close a cardiac or extracardiac shunt using occluder (double disc system, plug, coil…): closure of atrial septal defect, ventricular septal defect or patent arterial duct. For others, it is necessary to treat a valvular or vascular stenosis using a balloon catheter: dilatation of the pulmonary or the aortic valve, dilatation of aortic coarctation. For vascular stenosis, balloon angioplasty may be associated with stent implantation. Moreover, since more than 10 years, valve implantation can be performed: initially for pulmonic valve (the Melody™ valve from Medtronic or the Sapien™ valve from Edwards Lifesciences); but probably, most of the valves in the future could be implanted using appropriate tools and hybrid techniques combining cardiac catheterization and surgery. All these techniques were developed because of progress in fluoroscopy, and more recently association of different imaging techniques (echocardiography, MRI and CT) provides more information about the true anatomy. Interventional cardiac catheterization will continue to increase with use of new tools as 3D printing, tissue engineering and nano-techniques. It seems that from correction with open-heart surgery, many lesions could be repaired in future by hybrid techniques without opening the heart.

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.

Pulmonary atresia with intact septum: the use of Conquest Pro coronary guidewire for perforation of atretic valve and subsequent interventions

OBJECTIVE

To determine the feasibility and safety of the Conquest Pro wire as an alternative to radiofrequency wire for perforation of atretic pulmonary valve and subsequent balloon dilatation and patent ductus arteriosus stenting in patients with pulmonary atresia with intact ventricular septum.

BACKGROUND

Radiofrequency valvotomy and balloon dilatation has become the standard of care for pulmonary atresia with intact ventricular septum in many institutions today.

METHODS

We report eight consecutive patients in whom we used the Conquest Pro coronary guidewire, a stiff wire normally reserved for revascularisation of coronary lesions with chronic total occlusion, for perforation of atretic pulmonary valve and subsequent balloon dilatation, and stenting of the patent ductus arteriosus.

RESULTS

Perforation of atretic pulmonary valve was successful in seven out of eight cases. Radiofrequency valvotomy was employed after failure of perforation by the Conquest Pro wire in one case where the right ventricular outflow tract was broad based and tapered towards the pulmonary valve, and was heavily trabeculated. Failure of the Conquest Pro wire to perforate the pulmonary valve plate was mainly attributed by the failure to engage the wire at the correct position.

CONCLUSION

The Conquest Pro wire for perforation and subsequent interventions in the more straightforward cases of pulmonary atresia with intact ventricular septum is effective and safe, simplifying the entire procedure. However, the radiofrequency generator and wires remain essential tools in the paediatric interventional catheter laboratory.

Balloon valvuloplasty through the right ventricle: another treatment of pulmonary atresia with intact ventricular septum

BACKGROUND

This was a study to evaluate the safety and feasibility of balloon valvuloplasty of the pulmonary valve through the right ventricle (RV) for the treatment of pulmonary atresia with intact ventricular septum (PA-IVS).

METHODS

Ten neonates with PA-IVS, who underwent balloon valvuloplasty of the pulmonary valve through the RV at our institution from January 2008 to May 2010, were enrolled in this study. The oxygen saturation range was 60% to 83% (median 76%). The Z-value range of the tricuspid valve annulus was -2 to 2 (median 0.15), the diameter range of the pulmonary valve annulus was 4.6 to 8.6 mm (median 7.3), and the RV systolic pressure range was 88 to 124 mm Hg (median 106.5). A guidewire was used to perforate the pulmonary valve through the RV, followed by balloon dilation of the valve. The procedure was guided by transesophageal echocardiography.

RESULTS

The procedure was carried out successfully in all patients. The procedure time ranged from 64 to 110 minutes (median 82.5). Mechanical ventilation time ranged from 8 to 36 hours (median 11), and hospital stay ranged from 7 to 13 days (median 9). After the procedure, the median oxygen saturation increased to 89.5%, the median RV systolic pressure decreased to 45 mm Hg, and the gradient across the pulmonary valve ranged from 20 to 45 mm Hg (median 27.5). Minor complications included transient supraventricular tachycardia (n = 1), blood loss requiring transfusion (n = 2), moderate pulmonary regurgitation (n = 1), and mild pulmonary regurgitation (n = 3). There were no cases of cardiac perforation, main pulmonary artery aneurysm, or low output syndrome. Follow-up of patients ranged from 8 to 15 months (median 12.3). All patients remained clinically well.

CONCLUSIONS

Balloon valvuloplasty of the pulmonary valve through the RV is a safe and feasible alternative to surgical valvotomy or percutaneous balloon dilation. Early results are encouraging.

Catheter-based therapy for small preterm infants with pulmonary atresia/intact ventricular septum

Catheter-based therapy is the preferred treatment for term infants with pulmonary atresia and intact ventricular septum without right ventricular-dependent coronaries, membranous atresia with patent infundibulum, and acceptable-sized tricuspid valve. However, in smaller preterm infants, it is more difficult to determine the adequacy of the tricuspid valve and right ventricle for two-ventricle repair and there are increased procedural risks. An excellent result in a small preterm infant with pulmonary atresia and intact ventricular septum is described using the following algorithm: determination of the tricuspid/mitral annular ratio, right-sided catheter-based intervention, and a combination of transthoracic echocardiography and angiography.

Outcomes in neonates with pulmonary atresia and intact ventricular septum underwent pulmonary valvulotomy and valvuloplasty using a flexible 2-French radiofrequency catheter

PURPOSE

Outcomes in 6 neonates with pulmonary atresia and intact ventricular septum (PAIVS) undergoing radiofrequency pulmonary valvulotomy and valvuloplasty (RPVV) were reported to identify the factors favorable for RPVV as the treatment of choice.

MATERIALS AND METHODS

From May 2000 to January 2008, 6 patients with PAIVS were included in this retrospective study. They were aged 1 day to 90 days old. Study modalities included review of recordings of presentations and profiles of chest radiography, electrocardiography, echocardiography, and cardiac catheterization with angiography. Hemodynamic profiles from the echocardiography and the cardiac catheterization were analyzed.

RESULTS

Echocardiography showed severe tricuspid regurgitation, membranous atresia of the pulmonary valve, intact ventricular septum, patent ductus arteriosus, and hypoplastic right ventricle in 6 patients. The pulmonary valve annulus were 4.2 to 6.9 mm in diameters, and those of the tricuspid valve were 7.1 to 10.1 mm. Elevated serum level of cardiac enzymes were found in 1 patient with ventriculocoronary communication (VCC). At cardiac catheterization, the ratio of systolic pressure of the right ventricle to that of the left ventricle ranged from 1.43 to 2.33 before RPVV, and from 0.54 to 1.15 after RPVV (p=0.027). The pressure gradients ranged from 76 to 136 mmHg before RPVV, and from 15 to 39 mmHg after RPVV (p=0.028). The echocardiographic gradients ranged from 16 to 32 mmHg within 24 hours after RPVV, and from 15 to 50 mmHg at the follow-ups.

CONCLUSION

RPVV can be a treatment of choice for neonates with PAIVS, if there is patent infundibulum, no right-ventricular dependent coronary circulation, and adequate tricuspid valve and pulmonary valve.

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.

Catheterization in neonates with pulmonary atresia with intact ventricular septum

Cardiac catheterization is infrequently required in babies with pulmonary atresia with intact ventricular septum. The main indications are to decide on the best form of treatment, the options being determined by the right ventricular as well as infundibular morphology and the presence of right-ventricle dependent coronary circulation. In most cases, an interventional approach is appropriate. This can consist of radiofrequency or laser perforation of the atretic pulmonary valve, combined with balloon dilation. In some patients, additional stenting of the arterial duct may be needed.

Percutaneous balloon valvuloplasty of both pulmonary and aortic valves in a neonate with pulmonary atresia and critical aortic stenosis

We report a case of hydrops fetalis originating from critical aortic stenosis and pulmonary atresia with intact ventricular septum that was diagnosed in utero by echocardiography. We performed a percutaneous balloon valvuloplasty of the bilateral semilunar valves on the 2nd day after birth. We used a stiff-ended guidewire to perforate the pulmonary valve. After valvuloplasty, the aortic valve pressure gradient decreased from 55 to 25 mmHg. The procedure was successful, and the patient's heart condition improved.

The causes of Charcot-Marie-Tooth disease

Charcot-Marie-Tooth (CMT) disease serves as the summary term for the most frequent forms of inherited peripheral neuropathies that affect motor and sensory nerves. In the last 12 years, 14 genes have been identified that cause different CMT subforms. The genes found initially are predominantly responsible for demyelinating and dysmyelinating neuropathies. Genes affected in axonal and rare forms of CMT have only recently been identified. In this review, we will focus on the currently known genes that are associated with CMT syndromes with regards to their genetics and function.

Transcatheter pulmonary valve perforation and balloon dilatation in neonates with pulmonary atresia and intact ventricular septum

BACKGROUND

Pulmonary atresia and intact ventricular septum is characterised by a great morphological variety. Treatment is not uniform.

OBJECTIVE

To evaluate our experience with transcatheter valvotomy and balloon dilatation in neonates with pulmonary atresia and intact ventricular septum.

DESIGN

Retrospective.

METHODS

Between January 1997 and September 2000 five neonates with pulmonary atresia and intact ventricular septum underwent transcatheter valvotomy and balloon dilatation.

RESULTS

The catheter intervention was performed at a mean age of 27 days (range 3-95 days). The atretic pulmonary valve was successfully perforated in all neonates. Subsequent balloon dilatation was successful in four neonates. Balloon dilatation was unsuccessful in one patient, who underwent an elective surgical valvotomy of the pulmonary valve after five days. Three patients needed a modified Blalock-Taussig shunt after a mean of 23 days. Four patients required repeated balloon dilatation after a mean of 227 days. Mean follow-up was 2.7 years (range 1-5 years).

CONCLUSIONS

Transcatheter perforation of the pulmonary valve membrane and balloon dilatation is a good, safe initial therapy in selected neonates with pulmonary atresia and intact ventricular septum. This procedure can prevent open-heart surgery in these patients in the first months of life.

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.

Percutaneous balloon valvotomy in pulmonary atresia with intact ventricular septum: impact on patient care

BACKGROUND

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare congenital lesion with high mortality. Therapy was exclusively surgical until recently, when the use of radiofrequency-assisted perforation of the atretic valve was introduced as a treatment option. This study analyzes the outcomes and morphological changes to right heart structures after percutaneous perforation and balloon dilation of the atretic valve.

METHODS AND RESULTS

Between April 1992 and August 2000, 30 patients with PA-IVS underwent attempted percutaneous valve perforation and balloon dilation of the pulmonary valve. Longitudinal echocardiographic measurements of the tricuspid valve diameter, right ventricular length and area were recorded. Z scores were calculated according to published formulas. Perforation was achieved in 27 patients. In 14 patients a modified Blalock-Taussig shunt was performed between 2 and 24 days after valve dilation. There were 3 early and 2 late deaths. Among the survivors (follow-up time of 1 to 87 months), 16 patients had a biventricular circulation, 3 a 1(1/2)-ventricle circulation, and 1 a Fontan operation. Four patients are awaiting further palliation. There was no significant change of the tricuspid valve Z score or right ventricular length Z score with time.

CONCLUSIONS

Percutaneous balloon valvotomy is an effective treatment strategy for patients with PA-IVS provided that there is a patent infundibulum and a lack of a right ventricle-dependent coronary circulation. Despite the observation that right heart growth does not increase with body growth in early follow-up, it appears adequate to maintain a biventricular circulation in many patients.

Pulmonary Atresia with Intact Ventricular Septum

The prognosis for patients with pulmonary atresia with intact ventricular septum is poor with and without conventional surgical treatment. Because of this reason, a comprehensive program of medical, transcatheter, and surgical treatment is necessary to improve the long-term outlook of these infants. Algorithms of management plans should be developed based on the presence of right ventricular-dependent coronary circulation as well as size and morphology of the right ventricle. In a tripartite or bipartite right ventricle, transcatheter radiofrequency perforation is preferable. Alternatively, surgical valvotomy may be performed. Augmentation of pulmonary blood flow by prolonged infusion of prostaglandin E(1), stenting the ductus, or a surgical modified Blalock-Taussig shunt may be necessary in some of these patients. In patients with a unipartite or very small right ventricle or a right ventricular-dependent coronary circulation (Tricuspid valve Z score < -2.5), augmentation of pulmonary flow along with atrial septostomy should be undertaken. Follow-up studies to determine the feasibility of biventricular repair should be undertaken and, if feasible, surgical or transcatheter methods may be used to achieve the goals. If not suitable for biventricular repair, one-ventricle (Fontan) or one and one-half ventricular repair should be considered. Comprehensive and well-planned treatment algorithms may help improve survival rate.

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.

Stent implantation for superior vena cava occlusion after the Mustard operation

A 25-year-old man who had undergone a Mustard repair for complete transposition of the great arteries 21 years previously developed complete occlusion of the superior vena cava and obstruction of the inferior vena cava. Transcatheter recanalization was performed using needle puncture of the superior obstruction followed by stent implantation into both systemic venous pathways with relief of obstructive symptoms.

[Percutaneous pulmonary valvulotomy using radiofrequency in pulmonary atresia with intact interventricular septum]

Early pulmonary valvulotomy in patients with pulmonary atresia and intact interventricular septum allows the development and growth of the right ventricle and two-ventricle circulation. Percutaneous valvulotomy today is a valid alternative procedure to surgical valvulotomy. With the use of the radiofrequency 5F currently available for the treatment of arrythmias atretic pulmonary valve perforation and consecutive balloon dilation may be safely and effectively performed. We describe a case of perforation of a pulmonary valve by radiofrequency in a 15-day-old neonate with pulmonary valve atresia and intact ventricular septum.