Surgical Treatment of Wolff-Parkinson-White Syndrome in Infants and Children

Transcription

1 Surgical Treatment of Wolff-Parkinson-White Syndrome in Infants and Children Takuro Misaki, MD, Go Watanabe, MD, Takashi Iwa, MD, Yasuhiro Matsunaga, MD, Hiroshi Ohtake, MD, Makoto Tsubota, MD, Masao Takahashi, MD, and Yoh Watanabe, MD First Department of Surgery, Toyama Medical and Pharmaceutical University, Toyama, and First Department of Surgery, Kanazawa University, Kanazawa, Japan Electrophysiologic features and surgical results were examined in 55 pediatric patients who underwent surgical accessory pathway division for Wolff-Parkinson White syndrome. There were 3 male and 24 female patients ranging in age from 4 months to 5 years (mean age, 9.8 ± 4.2 years; 25 patients were less than 0 years old; 4 patients were less than 2 months). Eleven of these patients had associated congenital heart disease and underwent concomitant surgical procedures to treat those conditions. Preoperative effective refractory period of antegrade accessory pathways, the right atrium, atrioventricular node, and cycle length during reentrant tachycardia were shorter in pediatric patients than in adult patients. Antegrade accessory pathways showed right predominance more frequently in the pediatric group than in the adult group. Surgical techniques included an endocardial approach (an epicardial approach was used in patient) and concomitant operation for combined heart disease. The early mortality rate was 3.6%, whereas no late deaths occurred during the follow-up period of 96.8 ± 54.9 months (maximum follow-up, 205 months). The absolute cure rate was 92%. There were no significant differences in early and late mortality between pediatric and adult patients. Surgical treatment of the Wolff-Parkinson-White syndrome in pediatric patients is as safe and effective as in adults. Considering the potential complications from prolonged fluoroscopic exposure during catheter ablation, surgical division of accessory pathways in children is a promising modality for the treatment of Wolff-Parkinson-White syndrome in selected cases. (Ann Thorae Surg 994;58:03-7) A quarter of a century has passed since the first successful surgical division of an accessory atrioventricular pathway (ACP) for the treatment of the Wolff Parkinson-White (WPW) syndrome was performed by Sealy and associates (]. During most of this time, this technique had been considered the only definitive therapeutic modality for WPW syndrome [2-7]. However, the success of ACP division by high-frequency catheter ablation [8] has completely changed the concept of curative therapy, which formerly depended upon surgical management alone; high-frequency catheter ablation now is recognized as the conventional treatment for uncomplicated WPW syndrome [9, to]. As a consequence, use of surgical therapy for WPW syndrome now is limited to patients with catheter ablation failure, those with other cardiac diseases requiring concomitant surgical procedures, and those with multiple ACPs [] requiring prolonged fluoroscopy for catheter ablation. Furthermore, catheter ablation is technically difficult to perform in infants and small children. To date, we have operated on 55 pediatric patients with WPW syndrome. We report here the special features of Accepted for publication Nov 2, 993. Address reprint requests to Dr Watanabe, Department of Surgery, Toyama Medical and Pharmaceutical University, Sugitani Toyama 2630, Toyama, Japan by The Society of Thoracic Surgeons these patients and our surgical results, including those of long-term follow-up. Material and Methods Between November 973 and March 993, 456 patients underwent division of ACPs for WPW syndrome at Kanazawa University and Toyama Medical and Pharmaceutical University. Of these, 55 were younger than 5 years old (25 were younger than 0 years old; 2 were between 3 and 24 months old; 4 were less than 2 months old). The ages of pediatric patients ranged from 4 months to 5 years (mean age, 9.8 ± 4.2 years). These 55 patients (group A) were compared with adult patients with WPW syndrome undergoing ACP division (group B, n = 40) with regard to type and history of arrhythmias, number and location of ACPs, and short- and long-term surgical results. Right atrial and right ventricle effective refractory period (ERP), atrioventricular nodal ERP, ERP of antegrade ACP, cycle length of reentrant tachycardias, and the shortest RR interval during atrial fibrillation also were determined. Associated congenital heart lesions included Ebstein's anomaly in 6 patients; endocardial cushion defect in 2; ventricular septal defect, patent ductus arteriosis, and mitral regurgitation in ; tricuspid atresia in ; and mitral atresia associated with double-outlet right ventricle in /94/$7.00

2 04 MISAKI ET AL Ann Thorac Surg Table. Congenital Heart Disease in Pediatric Wolff Parkinson-White Syndrome Cardiac disease Ebstein's anomaly Tricuspid atresia Mitral atresia + DORV Endocardial cushion defect VSD, PDA, MR No. of DORV = double-outlet right ventricle; MR = mitral regurgitation; PDA = patent ductus arteriosus; TVR = tricuspid valve replacement; VSD = ventricular septal defect. The main surgical indications were drug-resistant tachycardia, recurrent episodes of syncope and supraventricular tachycardia necessitating cardioversion, or congestive heart failure due to both tachyarrhythmias and congenital heart disease. Surgical Technique Intraoperative electrophysiologic mapping was performed using a computerized mapping system. In 989, a multiple net electrode mapping system (HPM-700; Fukuda Denshi Co Ltd, Tokyo, Japan) was developed at our institute. This system decreases intraoperative epicardial mapping time to 3 minutes, minimizing hemodynamic deterioration. The surgical procedure for WPW syndrome was an endocardial approach with a beating heart for the right cardiac accessory pathways and with cardioplegic arrest for left cardiac type in which a supraannular incision was placed 2 mm above the mitral or tricuspid valve annulus extending 2 cm on either side of the accessory pathways [2]. Tissue at the site of the accessory pathways was dissected from underlying fat tissue in the atrioventricular groove and ventricular muscle. Before May 980 the incision was made by scalpel alone; subsequently, cryoablation (-60 C) of ventricular muscle was used to supplement scalpel dissection. After dissection of the involved area was accomplished, the atrial incision was closed with 4-0 Prolene (Ethicon, Somerville, NJ) running sutures. In patient who underwent Fontan procedure for treatment of tricuspid atresia, we used an epicardial approach without cardiopulmonary bypass because the accessory pathways were located near the right ventricular free wall. Procedures for treatment of other cardiac lesions were performed after division of accessory pathways. Ebstein's anomaly was treated by tricuspid valve replacement in 3 patients; Hardy's procedure, which consists of tricuspid annuloplasty with plication of atrialized right ventricle, was performed in the other 3 patients. Closure of a ventricular septal defect combined with mitral valve plasty and division of a patent ductus arteriosus was performed in patient, repair of the tricuspid valve in patient, Fontan procedure in patient, and repair of complete endocardial cushion defect in 2 patients (Table ). 6 2 Concomitant Procedure TVR3 Hardy procedure 3 Fontan procedure Radical operation 2 Radical operation Statistical Methods Results were expressed as mean ± standard deviation of the mean. Univariate analysis was performed with Student's t test and J? test or Fisher's exact test (when two or three elements were compared between groups) in consultation with Dr Kazuo Hashimoto, professor of the Department of Hygiene, Kanazawa University School of Medicine. Results Clinical Characteristics Clinical features of WPW syndrome in the pediatric group (group A) and the adult group (group B) are summarized in Table 2. There were significant differences between the two groups in the ratios of preoperative atrioventricular reentrant tachycardia and atrial fibrillation (p < 0.0), with many cases of atrial fibrillation in group B. Electrophysiologic data are shown in Table 3. The locations of accessory pathways in group A are summarized in Table 4; the distribution of ACP sites was significantly different between patients in the two groups. The most common location of accessory pathways was the right side in group A and the left side in group B, whereas the least common location in group A was the anteroseptal wall. Surgical Results Results are shown in Table 5. An 8-month-old infant with ventricular septal defect, patent ductus arteriosus, and mitral regurgitation associated with pulmonary hypertension died of respiratory failure day postoperatively, and a 2-year-old patient with complete endocardial cushion defect died of low output syndrome 2 days postoperatively. In the first patient ACP was located on the left posterior wall and the division of the ACP was performed after closure of ventricular septal defect and mitral valve piasty under cardioplegia. The additional time required for WPW surgical procedures was less than 30 minutes. In Table 2. Clinical Characteristics of Wolff-Parkinson-White Syndrome in Pediatric (Group A) and Adult (Group B) Group A Group B Clinical Characteristics (n = 55) (n = 40) P Value Type of tachycardia AVRT 55 (00%) 34 (85%) <0.0 AF tachycardia 2 (22%) 74(43%) <0.0 Number of ACPs. ± 0.3. ± 0.3 Number of patients with multiple ACPs 7 (3%) 37 (9%) Ventricular fibrillation 0 4 (3.5%) History of cardioversion 8 (5%) 35 (34%) <0.0 Postoperativeresidual atrial fibrillation 0 43 (%) <0.0 ACP = accessory pathway; AF tachycardia = tachycardia with a ~ a l fibrillation or flutter; AVRT = atrioventricular reentrant tachycardia: = not significant.

3 Ann Thorac Surg ; 5 8 : 0 ~ 7 MISAKI ET AL 05 T a b3. l ~ Electrophysiologic Characteristics for Wolff Parkmson-White Syndrome in Pediatric (Group A) and Adult (Group B) Electrophysiologic Group A Group B Characteristics (n = 55) (n = 40) P Value Right atrial ERP 98 ± ± 38 <0.0 Right ventricular ERP 209 ± ± 35 AV node ERP 233 ± ± 40 <0.0 Ante ACP ERP 26 ± ± 42 <0.05 Retro ACP ERP 26 ± ± 60 Cycle length of RT 306 ± ± 55 <0.0 Shortest RR AF tachycardia 28 ± ± 5 ACP =. accessory pathway; AF tachycardia = tachycardia with atrial fibrillation or flutter; Ante = antegrade; AV node = atrioventricular n ~ d e ;AVRT = atrioventricular reentrant tachycardia; ERP = effective ~ e f r a cpenod; t r y = not significant; RT = reentrant tachycardia. the second patient ACP was located on the right posterior wall. The division of the ACP was performed under c a r d i 0 -afrlree The g~ i t ~ duration. of WPW surgical procedures m this patient also was less than 30 minutes. Delta w ~ inv both e patients disappeared postoperatively, and neither death was related to ACP division itself. Of the remaining 53 patients the delta waves and recurrent tachyc?rdia disappeared in 49 patients. During the postoperative course, recurrence of the delta wave was seen in 3 and recurrence of RT was observed in. Recurrent RT without delta wave was seen in other patient. However, tachyarrhythmia disappeared thereafter without medical treatment in 3 and with medication in. The absolute cure rate was 92%. Long-term Results There were no late postoperative deaths (mean follow-up, 96.8 ± 54.9 months; range, 7 to 205 months). There was one instance of recurrent reentrant tachycardia, which was controlled medically. There was no residual postoperative atrial fibrillation in the pediatric group (group A) and the frequency of postoperative atrial fibrillation was s i g ~ i f ilower c a n tinl group y A than in group B. All patients showed a remarkable improvement in New York H e ~ r~ t s. s o c ifunctional a t i o n class, with only patient exhibiting class II characteristics, whereas the remaining 52 were designated class. T a b 4. ~ elocation of Accessory Pathways in Wolff-Parkinson W h ~ Syndrome t e in Pediatric (Group A) and Adult (Group B) Location of ACPs Right Left Posteroseptal Anteroseptal ACPs = accessory pathways; Group A (n = 55) 30 (55%) 23 (42%) 5 (9.%) 4 (7.5%) Group B (n = 40) 27 (32%) 245(6%) 56 (4%) 0 (2.5%) = not significant. p Value <0.0 <0.0 Table 5. Surgical Results Time of Death Early death Late death = not significant. Group A (n = 55) 2 o Group B (n = 40) p Value 6 Comment In 986 we reported results from the first 60 consecutive patients undergoing operation for WPW syndrome between 973 and 983 at Kanazawa University [6]. In the past several years many large series of surgically treated cases of WPW syndrome have been reported. However, only relatively small series of WPW syndrome in children [2-5] have been reported. It appears that the actual number of infants and children undergoing operation for WPW syndrome is small. In our series the surgical mortality was 3.6% and the absolute cure rate was 92%. This indicates that excellent long-term results and results comparable with those obtained in adults [3, 4] can be achieved in small children with WPW syndrome. Clinical and Electrophysiologic Features This report confirms that the electrophysiology of WPW syndrome in children is qualitatively the same as in adults [6] but differs in several important respects. The antegrade ERP of the atrioventricular node was shorter in children than in adults in our series. These findings agree with those of Gillette and colleagues [7] and Tonkin and associates [8]. However, contrary to previous reports [7, 8]: in our series the ERPs of antegrade ACP and the right atnum also were significantly shorter than those of adults. These findings could explain the significantly shorter cycle length during tachycardia in children because the ERP of the anatomic site (such as the right atrium or atrioventricular node) that contributes to reentrant tachycardia was shorter. Our data showed that the retrograde ERP of ACP in children was similar to that in adults. The etiology of the differences between the length of antegrade and retrograde ACPs is unknown. Recurrent paroxysmal atrial fibrillation has been reported in up to 32% of patients with WPW syndrome [9], whereas the incidence of atrial fibrillation associated with WPW syndrome is significantly reduced after division of a. c c ~ spathways s o. r y [20]. In our series preoperative atrial fibrillation was seen in 22% of patients; however, there was no postoperative residual atrial fibrillation associated ~ i WPW t ~ syndrome in pediatric patients. These findings m d ~ ctah tpreoperative ~ et atrial fibrillation in the pediatric patients With WPW syndrome was related specifically to WPW syndrome itself and the division of ACP. Therefore, early surgical treatment is recommended for selected patients to circumvent residual atrial fibrillation. The anatomic distribution of ACP locations was similar in children and adults except that right-sided pathways were predominant in children [6]. Crawford and associates [2] also reported a predominance of right-sided ACPs in children.

4 06 MISAKI ET AL Ann Thorae Surg Therapeutic Modalil"y Radiofrequency catheter ablation plays a major role in the nonpharmacologic treatment of WPW syndrome [9, 0], decreasing the need for surgical therapy []. However, there is a risk of malignancy associated with the fluoroscopic exposure required for catheter ablation, especially in children. Radiofrequency catheter ablation requires relatively long fluoroscopic exposure times for precise endocardial catheter placement and anchorage of the ablation catheter. Calkins, Lindsay, and their associates.[2, 22] reported that the incidence of malignancy due to fluoroscopy in patients less than 4 years old is.2% after hour of exposure, 2.3% after 2 hours, 3.5% after 3 hours, and 4.6% after 4 hours. The risk of a serious birth defect or genetic damage to the patient's offspring or fetal malignancy in the patient must be considered by physicians who recommend this therapy. For these reasons, in cases involving multiple ACPs or complicated cases that are anticipated to require a relatively long fluoroscopic exposure time, surgical treatment should be selected []. In our series 7 patients with multiple ACPs and with Mahaim fibers met these indications for operation. The technical aspects of catheter ablation are clearly more difficult in children, especially infants, than in adults. In infants, options for insertion of multiple catheter electrodes are limited and iatrogenic iliac arterial injury has been reported [23]. Aortic valve incompetence caused by catheter electrodes after catheter ablation in children also has been reported [24, 25]. The influence on the coronary arteries [25] and the risk of sudden death [26] remain unknown. Operation also is indicated in cases associated with cardiac lesions requiring surgical procedures []. In our series congenital heart disease was seen in cases and concomitant intracardiac procedures were performed in 0 of these. Drug therapy for WPW syndrome associated with congenital heart disease is problematic because of the pharmacologic actions of antiarrhythmic agents and digitalis. Antiarrhythmic agents may induce heart failure due to negative inotropic effect, whereas digitalis shortens the ERP of ACPs. In selected cases simultaneous procedures for WPW syndrome and congenital heart diseases were curative for both disorders. Concomitant operation for WPW syndrome and heart disease is complicated and lengthens operative time. The ACP division procedure requires approximately 30 minutes of aortic crossclamping for left-sided ACP, and 30 minutes of normothermic cardiopulmonary bypass with a beating heart is required for right-sided ACP. However, morbidity and mortality are entirely dependent on the severity of congenital heart disease and not on the addition of less than 30 minutes of WPW operation. Two patients in our series died in the early postoperative period. The causes of death were thought to be unrelated to the ACP divisions, but rather related to the surgical procedures for congenital heart disease itself. After April 985 there were no early deaths caused by surgical division of ACP with concomitant procedures for treatment of congenital heart disease at our institute. Thus, safe and reliable operation for pediatric WPW syndrome can be performed by a group of expert arrhythmia surgeons. This series demonstrates that surgical ablation of ACPs may be performed safely in small infants and children with results comparable with those obtained in adults. Considering the potential risk of fluoroscopic exposure during catheter ablation, we have become more aggressive in recommending surgical treatment for children. We thank Dr Masahiro Yamaguchi and Dr Yoshihiro Oshima for allowing us to report on 2 patients operated on by one of us (Dr Misaki) at Kobe Children's Hospital. References. Sealy WC, Hattler BG, Blumenschein SO, Cobb F. Surgical treatment of Wolff-Parkinson-White syndrome. Ann Thorac Surg 969;8:-. 2. Iwa T, Kawasuji M, Misaki T, Iwase T, Magara T. Localization and interruption of accessory conduction pathway in the Wolff-Parkinson-White syndrome. J Thorac Cardiovasc Surg 980;80: Gallagher JJ, Sealy WC, Cox JL, et al. Results of surgery for preexcitation caused by accessory atrioventricular pathways in 267 consecutive cases. In: Josephson ME, Wellens HJ, eds. Tachycardia: mechanisms, diagnosis, treatment. Philadelphia: Lea & Febiger, 984: COX JL, Gallagher JJ, Cain ME. Experience with 8 consecutive patients undergoing surgery for the Wolff-Parkinson White syndrome. J Thorac Cardiovasc Surg 985;90: Guiraudon GM, Klein GL, Sharma AD, Milstein S, McLellan DG. Closed-heart technique for Wolff-Parkinson-White syndrome: further experience and potential limitation. Ann Thorac Surg 986;42: Iwa T, Mitsui T, Misaki T, Mukai T, Magara T, Kamata E. Radical surgical cure of Wolff-Parkinson-White syndrome; the Kanazawa experience. J Thorac Cardiovasc Surg 986;9: Iwa T, Mukai K, Misaki T, Mitsui T, Matsunaga Y. Surgical management of the Wolff-Parkinson-White syndrome. In: Iwa T, Fontaine G, eds. Cardiac arrhythmias: recent progress in investigation and management. Amsterdam: Elsevier, 988: Borggrefe M, Budde T, Podezeck A, Breithardt G. High frequency alternating current ablation of an accessory pathway in humans. J Am Coli Cardiol 987;0: Jackman WM, Wang X, Friday KJ, et al. Catheter ablation of accessory atrioventricular pathways (Wolff-Parkinson-White syndrome) by radiofrequency current. N Engl J Med 99; 324: Kuck KH, Schluter M, Geiger M, Duckeck W. Radiofrequency current catheter ablation of accessory pathways. Lancet 99;337: Bolling SF, Morady F, Calkins H, et al. Current treatmentfor Wolff-Parkinson-White syndrome: results and surgical implications. Ann Thorac Surg 99;52: Crawford FA, Gillette PC, Ziegler V, Case C, Stroud M. Surgical treatment of Wolff-Parkinson-White syndrome in infants and small children. J Thorac Cardiovasc Surg 990;99: Iwa T, Kawasuji M, Misaki T, Magara T, Mukai K, Kobayashi H. Surgical treatment of the Wolff-Parkinson-White syndrome in infants and children. Ipn J Surg 98;: Ott DA, Garson A, Cooley DA, McNamara DG. Definitive operation for refractory cardiac tachyarrhythmias in children. J Thorac Cardiovasc Surg 985;90: Holmes DR, Danielson GK, Gersh BJ. Surgical treatment of accessory atrioventricular pathways and symptomatic tachycardia in children and young adults. Am J Cardiol 985;55:

5 Ann Thorac Surg MISAKI ET AL Gallagher JJ, Gilbert M, Svenson RH, Sealy WC, Kasell J, Wallace AG. Wolff-Parkinson-White syndrome; the problem, evaluation and surgical correction. Circulation 975;5: Gillette PC, Garson A, Kugler JD. Wolff-Parkinson-White syndrome in children: electrophysiological characteristics. Circulation 979;60: Tonkin AM, Miller HC, Svenson RH, Wallace AG, Gallagher JJ. Refractory period of the accessory pathways in the Wolff Parkinson-White syndrome. Circulation 975;52: Campbell RWF, Smith RA, Gallagher JJ, Pritchett ELC, Wallace AG. Atrial fibrillation in the preexcitation syndrome. Am J Cardiol 977;40: Sharma AD, Klein GJ, Guiraudon GM, Milstein S. Atrial fibrillation in patients with Wolff-Parkinson-White syndrome: incidence after surgical ablation of the accessory pathway. Circulation 985;72: Calkins H, Niklason L, Sousa J, El-Atassi R, Langberg J, Morady F. Radiation exposure during radiofrequency catheter ablation of accessory atrioventricular connection. Circulation 99;84: Lindsay BD, Eichling JO, Ambos 0, Cain ME. Radiation exposure to patients and medical personnel during radiofrequency catheter ablation for supraventricular tachycardia. Am J Cardiol 992;70: Schluter M, Kuck K. Radiofrequency current for catheter ablation of accessory atrioventricular connections in children and adolescents. Emphasis on the single-catheter technique. Pediatrics 992;89: Seifert MJ, Mordy F, Calkins HG, Langberg JJ. Aortic leaflet perforation during radiofrequency ablation. PACE 99;4: Scheinman MM. Catheter ablation for cardiac arrhythmias, personnel, and facilities. PACE 992;5; Schluter M, Geiger M, Siebels J, Duckeck W, Kuck K. Catheter ablation using radiofrequency current to cure symptomatic patients with tachyarrhythmias related to an accessory atrioventricular pathway. Circulation 99;84: Notice From the American Board of Thoracic Surgery The part I (written) examination will be held at the Atlanta Airport Hilton and Towers, Atlanta Airport, Atlanta, GA, on February 9, 995. The closing date for registration is August, 994. To be admissible for the part II (oral) examination, a candidate must have successfully completed the part I (written) examination. A candidate applying for admission to the certifying examination must fulfill all the requirements of the board in force at the time the application is received. Please address all communications to the American Board of Thoracic Surgery, One Rotary Center, Suite 803, Evanston, IL 6020.