Transcatheter occlusion of Blalock-Taussig shunts: technical options

Percutaneous Modified Blalock-Taussig Shunt Closure in a Patient with Isolated Right Ventricular Hypoplasia

Clinical presentation, course, and treatment for patients with isolated right ventricular (RV) hypoplasia (IRVH) depends on the degree of hypoplasia that is present-this is a spectrum from spontaneous maturation to Fontan circulation over time. An 8-month-old infant presented with IRVH; in the patient, a modified Blalock-Taussig (MBTS) shunt was closed percutaneously after spontaneous RV function recovery. A female newborn was diagnosed with differential cyanosis at birth. The echocardiography showed a hypertrophic RV with a small cavity, a right-left shunt on the atrial septal defect, an almost closed ductus arteriosus (DA), and a small tricuspid valve ring (Z-score-2) with mild regurgitation (pressure gradient 30 mmHg). On the 4th day of life, the patient showed deepened cyanosis and hyperlactatemia was registered. The echocardiography examination revealed a closed DA. Right ventriculography performed on the 5th day of life evidenced the presence of a small hypertrabeculated RV. The pressure in the RV increased. A right-side MBTS was created on the 6th day of life. Further echocardiographic findings indicated a gradual development of the RV and a decrease in RV pressure. MBTS occlusion was performed when the patient was 8 months old. Vital parameters were monitored invasively and noninvasively after the balloon occlusion of MBTS. Percutaneous MBTS occlusion was successfully performed using an Amplatzer vascular plug 2 (AVP2). During the follow-up period, the patient was found to have maintained a normal percutaneous oxyhaemoglobin blood saturation.

Percutaneous closure of a modified Blalock-Taussig shunt using an amplatzer vascular plug

Modified Blalock-Taussig shunts are usually clamped during the successive corrective or palliative surgical procedures carried out to treat underlying congenital heart disease, though at times they may be left permeable for a number of reasons. Subsequently, when this is no longer considered necessary and closure is indicated, the method of choice is percutaneous embolization using various coils or other devices. We report on a series of patients in whom this type of shunt was closed successfully via an arterial approach using a new device: the Amplatzer Vascular Plug. In addition to employing a controlled-release system, this type of plug has the advantage that it can be implanted using low-profile catheters. The patients were 1, 4 and 23 years old, respectively, and no complications were reported. The fluoroscopy time was 10, 11 and 9 minutes, respectively, and patients were followed up for 42 months.

Percutaneous closure of Blalock-Taussig shunts using Gianturco coils

Permeability of a Blalock-Taussig shunt can increase the risk of endocarditis and ventricular overload. Percutaneous embolization of these shunts gives variable results. We report our experience in 10 patients with percutaneous closure of modified Blalock-Taussig shunts using retrograde arterial embolization with Gianturco coils. The patients' median age was 2.8 years, and their median weight was 12 kg. Most patients had minor stenosis of the distal portion of the anastomosis. In all cases, complete closure of the shunt was achieved without complications using a median of one coil per patient. The technique was feasible, safe, effective, and inexpensive.

Transcatheter occlusion of a modified Blalock-Taussig shunt using the amplatzer vascular plug with the catheter-snare technique

A 16-month-old boy with previous repair of a critical pulmonary stenosis had persistence of a right modified Blalock-Taussig shunt. Transcatheter occlusion of the modified Blalock-Taussig shunt was achieved using the Amplatzer vascular plug with the catheter-snare technique.

Successful microsurgical extraction of a migrated coil in a pediatric patient after failed endovascular closure of a Blalock-Taussig shunt. Case report

Coil migration is a rare but potentially serious complication of endovascular procedures. Occasionally coils can be retrieved via endovascular techniques. The authors describe the microsurgical management of a case in which endovascular techniques failed. A 2-year-old girl with pulmonary atresia and a Blalock-Taussig shunt underwent attempted endovascular closure of the shunt with Gianturco steel coils. During deployment, a coil was lost in the aorta and an angiogram showed that it had lodged in the proximal M1 segment of the middle cerebral artery. The coil could not be retrieved by endovascular techniques, and the patient was taken to the operating room to undergo a craniotomy. After the sylvian fissure was split, the coil was visible through the vessel wall. Temporary clips were placed on the proximal M1 and the proximal M2 segments, trapping the coil. A small arteriotomy was performed, the coil was removed, and the arteriotomy was closed. A cerebral angiogram showed excellent perfusion with no dissections. The patient's motor examination demonstrated a mild hemiparesis on the left with no tremulousness. Coil migration can be treated by microsurgical techniques in pediatric patients with a good clinical outcome.

Hybrid approach to surgical correction of tetralogy of Fallot in all patients with functioning Blalock Taussig shunts

BACKGROUND

In total surgical correction of tetralogy of Fallot (TOF) with functioning Blalock Taussig shunts (BTS), shunt take down increased surgical time, bleeding, and might injure phrenic and recurrent laryngeal nerve and thoracic duct.

OBJECTIVES

A routine hybrid approach using transcatheter BTS closure immediately before total surgical correction of TOF in all patients might reduce these problems. We analyze the safety and feasibility of this approach.

METHODS

Transcatheter BTS closure was achieved using single or multiple stainless steel embolization coils, Amplatzer vascular plugs, or duct occluders. When coils were released without control by bioptome forceps, coil migration in larger shunts was prevented by proximal or distal balloon occlusion.

RESULTS

This routine hybrid strategy was followed in 22 consecutive patients aged 1-13 years over 4-year-period and 21 procedures were successful. Among the 16 patients attempted with coils, 13 had successful closure, 2 needed Amplatzer duct occluder devices, and 1 sent for surgical shunt takedown due to acute angulation of the shunt. New Amplatzer vascular plugs were used in six patients. Bioptome was used in six patients and proximal or distal balloon occlusion of flow was used in three patients. Four patients had closure of associated aortopulmonary or chest wall collaterals.

CONCLUSION

Hybrid approach using routine transcatheter closure of all BTS immediately before surgical correction of TOF shunts with coils/plugs/devices is safe, feasible, and reproducible.

Techniques and applications of transcatheter embolization procedures in pediatric cardiology

Transcatheter embolization of congenital or acquired superfluous vascular structure has become routine procedures performed by interventional pediatric cardiologists. Embolization procedure is often part of a collaborative effort with cardiac surgeons to palliate complex congenital heart defect, such as in embolizing aortopulmonary collateral arteries in patient with single ventricle physiology. In other cases, the procedure is the definitive treatment as in embolizing coronary artery fistula. Pediatric cardiologists performing embolization procedures should be familiar with available technologies as well as understand the underlying cardiac anatomy and pathophysiology. This article provides a comprehensive review of presently available embolization agents and technologies. Some of the technologies are used only by interventional radiologists but may be useful to pediatric cardiologists. Specific clinical applications in pediatric cardiology are also discussed with summary of current literature. With continue advancement in transcatheter technology and operator expertise, all unwanted vascular communication should be amenable to transcatheter embolization.

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.

Transcatheter closure of surgical shunts in patients with congenital heart disease

The aim of this study was to review contemporary techniques, devices, and results of transcatheter occlusion of surgical shunts in 2 pediatric cardiac programs. Closure of superfluous surgical shunts may reduce cardiac work and risk of endocarditis. Previous studies have shown that transcatheter closure of shunts is feasible, but have not demonstrated acceptable efficacy or safety. In addition, the performance of new techniques and devices has not been reviewed. Between 1993 and 1998, 18 patients with congenital heart disease underwent transcatheter closure of 19 Blalock-Taussig shunts. Detachable and standard Gianturco coils and Gianturco-Grifka vascular occlusion devices were employed. All 19 shunts had complete closure. Eight shunts had initial placement of detachable coils. Five shunts had stents placed that bridged the pulmonary end of the shunts. These 5 and 4 additional shunts had closure by standard coils. Two shunts were closed with Gianturco-Grifka devices. There were no complications, no embolizations, and no requirement for surgery precipitated by the procedures. This review of contemporary techniques, devices, and results suggests that transcatheter occlusion of surgical shunts is effective and safe.

Wire-snare technique with distal flow control for coil occlusion of a modified Blalock-Taussig shunt

Coil occlusion of Blalock-Taussig shunts has been associated with a high rate of device embolization. We describe a technique consisting of transvenous snaring and exteriorization of a guidewire advanced through a modified left Blalock-Taussig shunt, allowing distal shunt flow control and successful coil occlusion of the shunt. Cathet. Cardiovasc. Intervent. 49:51-54, 2000.

Transcatheter closure of modified Blalock-Taussig shunt with Gianturco-Grifka Vascular Occlusion Device

A 15-year-old girl with previous repair of a complex cyanotic congenital heart defect had persistence of a modified left Blalock-Taussig shunt that could not be ligated at surgery. Six years later, antegrade delivery of a Gianturco-Grifka Vascular Occlusion Device resulted in complete closure of the shunt. Cathet. Cardiovasc. Intervent. 48:365-367, 1999.

[Guidelines of clinical practice of the Spanish Society of Cardiology. Requirements and equipment of invasive techniques in pediatric cardiology: clinical application]

Invasive techniques in pediatric cardiology have experienced a big change since the 80's. The growth of non-invasive methods for diagnosing congenital heart defects has made the number of diagnostic catheterizations decrease remarkably. On the other hand, the notable development of pediatric interventional catheterization techniques will allow that, in the near future, the number of therapeutic catheterizations overcomes the diagnostic ones in our country. The former are more difficult and dangerous, so they require experienced and skilled hands and more economic resources. This chapter is divided in three main sections: I) Requirements and equipment needed for pediatric invasive techniques; II) Current indications, contraindications and complications of the diagnostic catheterization, and III) Techniques, indications and results of pediatric therapeutic catheterization: current state. Likewise, we state the suitability or not for these therapeutic procedures in different cardiac anomalies.

Interventional cardiac catheterization

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

Percutaneous coil occlusion of ascending aorta to pulmonary artery shunts

Two patients with pulmonary atresia and intact ventricular septum each underwent early palliative surgery with a pulmonary valvotomy and an ascending aorta to pulmonary artery shunt. Adequate right ventricular growth and relief of pulmonary stenosis rendered the shunts unnecessary. The shunts were successfully occluded percutaneously with Gianturco coils.

Closure of Blalock-Taussig shunts using a new detachable coil device

Two children underwent interventional closure of a modified Blalock-Taussig shunt using a new detachable coil system (Duct-Occlud). This procedure has advantages over currently available materials to occlude these and other communications between the systemic and pulmonary circulations.