Balloon Valvuloplasty Through the Right Ventricle: Another Treatment of Pulmonary Atresia With Intact Ventricular Septum

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1 Balloon Valvuloplasty Through the Right Ventricle: Another Treatment of Pulmonary Atresia With Intact Ventricular Septum Qian-zhen Li, MD, Hua Cao, MD, Qiang Chen, MD, Gui-Can Zhang, MD, Liang-Wan Chen, MD, and Dao-Zhong Chen, MD Department of Cardiovascular Surgery, Union Hospital, Fujian Medical University, Fuzhou, People s Republic of China 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. (Ann Thorac Surg 2013;95:1670 4) 2013 by The Society of Thoracic Surgeons Pulmonary atresia with intact ventricular septum (PA- IVS) accounts for less than 1% of congenital heart defects, and has a poor prognosis [1]. This condition displays a wide range of morphology with varying degrees of right ventricular (RV) hypoplasia (single chamber, bipartite, or tripartite), tricuspid regurgitation, and RV-coronary artery sinusoids, which may result in RVdependent coronary circulation. The ideal therapeutic strategy is to decompress the RV by opening the outflow tract and establishing biventricular circulation [2]. Initially, surgery was the only treatment option, and open pulmonary valvotomy with or without systemic-to-pulmonary artery shunt was the most common procedure [3]. During the early 1990s the first descriptions of percutaneous pulmonary valve perforation were reported, using guidewires with laser energy followed by balloon dilation [4]. This was followed by the use of stiff guidewires for mechanical perforation [5]. More recently, the application of guidewires with Accepted for publication Feb 4, Address correspondence to Dr Hua, Department of Cardiovascular Surgery, Union Hospital, Fujian Medical University, Fuzhou, , P. R. China; caohua69@hotmail.com. radiofrequency energy has been proven to be safe and effective [6 8]. However, the percutaneous approach cannot always be used in neonates because of their small size and limited vascular access [9]. The percutaneous approach also needs advanced equipment, which has a high cost that limits its availability in third world countries [10]. As laser and radiofrequency equipment are often not available, surgery is still the main treatment option in lowincome countries. Consequently we have developed another technique that has few complications, a low mortality rate, and good cosmetic results. The aim of this study was to evaluate the safety and feasibility of balloon valvuloplasty of the pulmonary valve through the RV. Patients and Methods Patients Ten neonates with PA-IVS were enrolled, prospectively, at our institution from January 2008 to May 2010 (Table 1). The age range of patients was 5 to 27 days (median 12.5), the weight range was 2.9 to 4.5 kg (median 3.5), and the oxygen saturation (Spo 2 ) range was 60% to 83% (median 76%). All patients underwent detailed echocardiographic 2013 by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc

2 Ann Thorac Surg LI ET AL 2013;95: BALLOON VALVULOPLASTY THROUGH THE RIGHT VENTRICLE 1671 Table 1. Clinical and Echocardiographic Data Variable Median age in days (range) 12.5 (5 27) Median weight in kg (range) 3.5 ( ) Median TVA Z value (range) 0.15 ( 2 2) TVA tricuspid valve annulus. examination before treatment. Informed consent was obtained from the parents of each patient. The contraindications for enrollment were the following: an RV-dependent coronary circulation; a severely attenuated RV cavity; or a severely stenotic or hypoplastic infundibulum. The Z-value of the tricuspid valve annulus was obtained using the nomogram previously described by Hanley and colleagues [3], and was defined as (measured diameter mean normal diameter) (standard deviation of the mean normal diameter). The patients enrolled in this study had a Z-value range of 2 to 2 (median 0.15). The diameter range of the pulmonary valve annulus (PVA) was 4.6 to 8.6 mm (median 7.3) and the RV systolic pressure (RVSP) range was 88 to 124 mm Hg (median 106.5). All 10 patients received a prostaglandin E1 infusion and balloon valvuloplasty of the pulmonary valve through the RV. Procedure Under general anesthesia, patients were placed in the supine position and draped to expose the entire chest. The diameters of the tricuspid valve annulus and PVA were measured by transesophageal echocardiography to decide the size of the balloon (about 1.3 times the diameter of the PVA). A small incision was made below the sternum (3 to 5 cm in length) and the inferior pericardium was opened and retracted to expose the RV. A suture was placed on the surface of the RV, 1.5 to 2 cm from the PVA. Heparin was administered (1 mg/kg body weight, intravenous) and the activated clotting time was confirmed to be greater than 250 seconds. A trocar (16 or 18 G) was punctured into the RV at the location of the suture. The direction of the trocar was adjusted under Fig 2. The arrow shows the guidewire placed in the main pulmonary artery (PA) through the right ventricle (RV). (RA right atrium.) continuous transesophageal echocardiography guidance to ensure that it perforated the middle of the pulmonary valve in a vertical direction. A guidewire was inserted into the trocar and the trocar was withdrawn (Figs 1 and 2). After confirmation that the guidewire was still in the main pulmonary artery, the balloon (Tyshak-II, NuMed Canada Inc, Cornwall, Canada) was placed in the main pulmonary artery over the guidewire. The end of the 3-cm balloon was advanced through the PVA for about 1.5 cm to ensure that the PVA was at the middle of the balloon. The balloon was dilated for about 3 seconds by injecting normal saline at a pressure of 10 to 12 cm H 2 O (Figs 3 and 4). This was repeated 3 times, and was then repeated with a bigger balloon if the pressure gradient across the pulmonary valve was still greater than 40 mm Hg. The balloon and guidewire were then withdrawn. The arterial duct and atrial septal defect were remained except the first patient. A modified Blalock-Taussig shunt (B-T shunt) was performed in patients with persistent Fig 1. Incision was made below the sternum. A suture was placed on the surface of the right ventricle. The trocar was punctured into the right ventricle at the location of the suture. The guidewire was inserted into the trocar. Fig 3. The balloon was placed in the main pulmonary artery and was dilated by injecting normal saline. (RA right atrium; RV right ventricle.)

3 1672 LI ET AL Ann Thorac Surg BALLOON VALVULOPLASTY THROUGH THE RIGHT VENTRICLE 2013;95: Table 3. Hemodynamic Characteristics Characteristic Median Spo 2 in % (range) Pre 76 (60 83) Post 89.5 (87 95) F/U 96 (95 98) Median RVSP in mm Hg (range) Pre (88 124) Post 45 (40 55) F/U 31 (28 50) Median gradient in mm Hg (range) Post 27.5 (20 45) F/U 20.5 (12 40) Fig 4. The arrow shows the forward flow across the pulmonary valve annulus after balloon dilation. hypoxemia (Spo 2 80%). The prostaglandin E1 and milrinone infusions were continued after the procedure. Results Balloon valvuloplasty was successful in all patients. The size of the balloon ranged from 6 to 11 mm (median 9.5). The skin-to-skin time ranged from 64 to 110 minutes (median 82.5). After the procedure, the median RVSP decreased to 45 mm Hg, the median spo 2 increased to 89.5%, and the gradient across the pulmonary valve ranged from 20 to 45 mm Hg (median 27.5). The mechanical ventilation time ranged from 8 to 36 hours (median 11), and hospital stay ranged from 7 to 13 days (median 9) (Tables 2 and 3). Minor complications occurred in some patients. The second patient had transient supraventricular tachycardia during dilation that recovered without treatment. Blood loss requiring transfusion occurred in the first 2 patients because of lack of experience. None of the patients developed severe pulmonary regurgitation, but the sixth patient developed moderate pulmonary regurgitation and 3 other patients developed mild pulmonary regurgitation. There were no cases of cardiac perforation, main pulmonary artery aneurysm, or low output syndrome. The first patient underwent ligation of the patent ductus arteriosus because of good Spo 2 (95%) after dilation. However, the Spo 2 decreased to 75% at 24 hours after the procedure and the patient underwent reoperation to open the arterial duct. The Spo 2 then increased to 93% during the hospitalization. Table 2. Clinical Data After Balloon Valvuloplasty Variable Median millimeters of the diameter of 9.5 (6 11) balloon (range) Median minutes of operation time (range) 82.5 (64 110) Median hours of ventilation time (range) 11 (8 36) Median days of hospital stay (range) 9 (7 13) F/U follow-up; gradient gradient across the pulmonary valve; Pre (Post) before (after) attempted pulmonary balloon valvuloplasty; RVSP right ventricular systolic pressure; Spo 2 transcutaneous oxygen saturation. One patient required a modified B-T shunt at the time of the procedure because of severe persistent hypoxemia (Spo 2 70%) after dilation. The Spo 2 increased to 95% after the shunt. At 13 months of age, the Spo 2 was 96% and the RVSP was 40 mm Hg, and ligation of the B-T shunt was performed. This patient continued to do well. Another patient still had a high gradient across the pulmonary valve (55 mm Hg) after balloon dilation with an 8 mm balloon. After dilation with a 9-mm balloon, the gradient decreased to 45 mm Hg. Follow-up of patients ranged from 8 to 15 months (median 12.3). Out-patient follow-up was by transcutaneous oxygen monitor and echocardiography. All patients remained clinically well. The median spo 2 increased to 96% (range 95% to 98%), the RVSP decreased to 31 mm Hg (range 28 to 50), and the peak gradient pressure across the pulmonary valve ranged from 12 to 40 mm Hg (median 20.5). One patient received surgical valvotomy 6 months after balloon dilation. All patients achieved biventricular circulation. No progressive moderate to severe pulmonary regurgitation occurred. No severe hypoxemia and right heart function failure or other complications were found during the follow-up period (Table 3). Comment Pulmonary atresia with intact ventricular septum is a rare congenital heart condition with a poor prognosis [1]. Treatment is required early in life because about 50% of untreated infants die before the age of 1 month and few untreated infants survive for longer than 12 months [11, 12]. Initially, surgery was the only option but it was associated with a high mortality rate; more recently primary treatments including laser guidewires, radiofrequency-assisted valvotomy, and balloon dilation, which have achieved lower complication and mortality rates [4, 6, 7, 13]. Percutaneous balloon dilation has been proven to be safe and effective, and has therefore increased in popularity. However, this procedure carries a risk of complications such as cardiac perforation, main pulmonary

4 Ann Thorac Surg LI ET AL 2013;95: BALLOON VALVULOPLASTY THROUGH THE RIGHT VENTRICLE 1673 artery aneurysm, and femoral artery damage [7, 8]. Patients are always younger than 12 months and often younger than 1 month. Because of the small size and limited vascular access in these patients, the percutaneous approach is not always possible [9], which limits the usefulness of the procedure. We therefore developed an alternative technique of pulmonary balloon valvuloplasty through the RV. The early outcomes of our procedure are encouraging, with a low complication rate and no deaths. A good clinical outcome with improvement in hypoxemia was achieved in all patients. There were no cases of cardiac perforation, main pulmonary artery aneurysm, or low output syndrome. The open-chest approach allowed the procedure to be performed under direct vision, making it relatively easy for experienced surgeons to avoid cardiac perforation and carefully control the procedure. Because cardiopulmonary bypass was not needed low output syndrome was uncommon, as with the percutaneous approach. Our procedure also carried no risk of radiation exposure for the surgeons. The incision length was only 3 to 5 cm, which was easy to extend if conversion to an open-heart procedure was required because of failure of the balloon valvuloplasty, or an unexpected event occurred such as malignant arrhythmia or the need for a B-T shunt. Relatively high medical costs present a significant challenge for using the percutaneous approach in third world countries, where many hospitals do not have the resources to provide the necessary equipment [10]. However, our technique does not require expensive radiology equipment and is easily mastered. In a low-income country where healthcare resources are limited, this cost-effective technique could be a good choice for the treatment of PA-IVS. At the beginning of the study period, there was no generally accepted standard therapeutic approach that took into account the variable anatomy of patients with PA-IVS. The degree of RV hypoplasia and the presence or absences of an RV-dependent coronary circulation are the main factors determining therapeutic strategy. As the morphologic characteristics of the RV are considered to be the main determinant of outcome, careful patient selection is important. Bull and colleagues [14] reported that tripartite RVs were well-developed. The Z-value, which uses the nomogram of the Congenital Heart Surgeon Study Group Protocol, has been used to assess the degree of RV hypoplasia since January 1996 [15]. Right ventricular hypoplasia is defined as mild if the Z-value is 2 to 0, moderate if the Z-value is 2 to 3, and severe if the Z-value is less than 3. Velvis and colleagues [16] and Ovaert and colleagues [17] confirmed that neonates with mild or moderate RV hypoplasia could achieve a well-developed RV and establish biventricular circulation after opening of the outflow tract. Even though it has been shown that very hypoplastic RVs can grow, most authors agree that biventricular repair is unlikely to be achieved when the Z-value of the tricuspid valve is less than 4 [18]. We used the same criteria for percutaneous balloon dilation as those used by Qureshi and colleagues [4]; tripartite RV, Z-value 2 or higher, no coronary artery-rv fistula, and no severely stenotic or hypoplastic infundibulum. At the beginning of our study we did not realize the importance of the arterial duct owing to our lack of experience. Late hypoxemia may occur after valvuloplasty due to spasm of the pulmonary artery and RV outflow tract (RVOT). Because of the remaining obstruction of the RVOT, Spo 2 generally does not return to the normal range immediately after the procedure. However, Spo 2 may improve after opening of the RVOT. A B-T shunt may be required in cases of persistent hypoxemia, and prostaglandin E1 can also be used to keep the arterial duct open while the patient is in the intensive care unit. As with any retrospective study, potential biases are associated with our data collection. Because of the low number of patients with PA-IVS our experience is limited. Further studies with longer follow-up are needed to determine long-term outcomes. This was a single-center study and other centers may obtain different outcomes. Another limitation is that this study was conducted in a low-income country and the relative cost-effectiveness may be different in high-income countries. In conclusion, our study demonstrated that balloon valvuloplasty of the pulmonary valve through the RV is a safe and feasible alternative to surgical valvotomy or percutaneous balloon dilation. This procedure has low complication and mortality rates, including avoidance of cardiac perforation and femoral artery damage, and protects surgeons from radiation exposure. The procedure is easy to learn, and the cost could be acceptable in developing countries. Balloon valvuloplasty of the pulmonary valve through the RV is recommended, especially in low-income countries. References 1. Freedom RM, Mawson MB, Yoo SJ, Benson LN. Pulmonary atresia and intact ventricular septum. In: Freedom RM, Mawson MB, Yoo SJ, Benson LN, eds. Congenital heart disease. Textbook of angiography. Armonk, NY: Futura Publishing Co., Inc; 1997: De Leval M, Bull C, Stark J, Anderson RH, Macartney FJ. Pulmonary atresia and intact ventricular septum: surgical management based on a revised classification. Circulation 1982;66: Hanley FL, Sade RM, Freedom RM, Blackstone EH, Kirklin JW. Outcomes in critically ill neonates with pulmonary stenosis and intact ventricular septum: a multiinstitutional study. J Am Coll Cardiol 1993;105: Qureshi SA, Rosenthal E, Tynan M, Anjos R, Baker E. Transcatheter laser assisted pulmonary valve dilation in pulmonary valve atresia. Am J Cardiol 1991;67: Latson LA. Nonsurgical treatment of a neonate with pulmonary atresia and intact ventricular septum by transcatheter puncture and balloon dilation of the atretic valve membrane. Am J Cardiol 1991;68: Rosenthal E, Qureshi SA, Chan KC, et al. Radiofrequencyassisted balloon dilatation in patients with pulmonary valve atresia and an intact ventricular septum. Br Heart J 1993;69: Gibbs JL, Blackburn ME, Uzun O, Dickinson DF, Parsons JM, Chatrath RR. Laser valvotomy with balloon valvoplasty for

5 1674 LI ET AL Ann Thorac Surg BALLOON VALVULOPLASTY THROUGH THE RIGHT VENTRICLE 2013;95: pulmonary atresia with intact ventricular septum five years experience. Heart 1997;77: Alwi M, Geetha K, Bilkis AA, et al. Pulmonary atresia with intact ventricular septum percutaneous radiofrequencyassisted valvotomy and balloon dilation versus surgical valvotomy and Blalock Taussig shunt. J Am Coll Cardiol 2000;35: Baskett RJ, Tancock E, Ross DB. The gold standard for atrial septal defect closure: current surgical results, with an emphasis on morbidity. Pediatr Cardiol 2003;24: Vida VL, Barnoya J, O Connell M, Leon-Wyss J, Larrazabal LA, Castañeda AR. Surgical versus percutaneous occlusion of ostium secundum atrial septal defects: results and costeffective considerations in a low-income country. J Am Coll Cardiol 2006;47: Lightfoot N, Coles J, Freedom RM. Survival analysis. In: Freedom RM, ed. Pulmonary atresia with intact ventricular septum. Valley Stream, NY: Futura; 1989: Kirklin JW. Barratt-Boyes BG. Pulmonary atresia and intact ventricular septum. In: Kirklin JW, Barratt-Boyes BG, eds. Cardiac Surgery, 2nd ed. New York: Churchill Livingstone; 1993: Mi YP, Chau AK, Chiu CS, Yung TC, Lun KS, Cheung YF. Evolution of the management approach for pulmonary atresia with intact ventricular septum. Heart 2005;91: Bull C, de Leval MR, Mercanti C, et al. Pulmonary atresia and intact ventricular septum: a revised classification. Circulation 1982;66: Coles JG, Freedom RM, Lightfoot NE, et al. Long term results in neonates with pulmonary atresia and intact ventricular septum. Ann Thorac Surg 1989;47: Velvis H, Raines KH, Bensky AS, Covitz W. Growth of the right heart after balloon valvuloplasty for critical pulmonary stenosis in the newborn. Am J Cardiol 1997;79: Ovaert C, Qureshi SA, Rosenthal E, Baker EJ, Tynan M. Growth of the right ventricle after successful transcatheter pulmonary valvotomy in neonates and infants with pulmonary atresia and intact ventricular septum. J Thorac Cardiovasc Surg 1998;115: Agnoletti G, Piechaud JF, Bonhoeffer P, et al. Perforation of the atretic pulmonary valve; long-term follow-up. J Am Coll Cardiol 2003;41: INVITED COMMENTARY Dr Qian-zhen and colleagues [1] report a small series of infants with pulmonary atresia and intact ventricular septum, with anatomy favorable for biventricular repair, who underwent a novel hybrid surgical approach to balloon pulmonary valvotomy. This was done through the right ventricular free wall through a small subxiphoid incision under echocardiographic control without cardiopulmonary bypass. The authors propose that this could be a cost-effective alternative to percutaneous balloon valvotomy with the use of radiofrequency or laser energy in the cardiac catheterization laboratory, particularly in developing countries. The authors results in this highly selected group of infants were excellent, although there clearly was a learning curve: their first 2 patients required blood transfusion. This technique may not seem to be of much relevance to surgeons working at centers with access to excellent interventional cardiology procedures with good radiologic equipment, but it may be of considerable interest to centers without such services. Longer follow-up times to compare survival, rate of biventricular repair, and need for reintervention with the percutaneous approach is needed. The technique described here, while avoiding radiation and radiofrequency equipment, still requires cardiac operation and transesophageal echocardiography (in small infants), so it is not intuitively less costly or less challenging than the percutaneous approach. Thus, data supporting the authors thesis would be helpful. Finally, the authors use of the right ventricular free wall to access the pulmonary valve without cardiopulmonary bypass is a reminder that innovative surgeons can help our cardiology colleagues with procedures such as percutaneous pulmonary valve implantation when peripheral vascular access issues or tricuspid valve pathology prevents a transvenous approach to the valve. David B. Ross, MD 2D4.37 Walter MacKenzie Health University of Alberta Hospital 2D4.37 Walter MacKnezie Health Sciences Centre th St Edmonton, AB, Canada T6G 2B7 dbross@cha.ab.ca Reference 1. Li QZ, Cao H, Chen Q, Zhang GC, Chen LW, Chen DZ. Balloon valvuloplasty through the right ventricle: another treatment of pulmonary atresia with intact ventricular septum. Ann Thorac Surg 2013;95: by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc