Ann Thorac Surg 2002;73:102-106
© 2002 The Society of Thoracic Surgeons
Original article: cardiovascular
Arrhythmia after modified total cavopulmonary connection without use of prosthetic material
Takaaki Suzuki, MD*a,
Takayasu Murai, MDb,
Masaaki Sato, MDb,
Tsutomu Ito, MDa,
Toyoki Fukuda, MDa
a Division of Cardiovascular Surgery, Tokyo Metropolitan Children’s Hospital, Tokyo, Japan
b Division of Cardiology, Tokyo Metropolitan Children’s Hospital, Tokyo, Japan
Accepted for publication September 19, 2001.
* Address reprint requests to Dr Suzuki, Division of Pediatric Cardiovascular Surgery, University of Michigan Medical Center, F 7830 Mott Children’s Hospital, 1500 East Medical Center Dr, Ann Arbor, MI 48109-0223, USA
e-mail: suzukimd{at}blue.ocn.ne.jp
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Abstract
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Background. Although total cavopulmonary connection without use of prosthetic material appeared to be a promising surgical procedure that would retain potential growth of the intraatrial tunnel, midterm incidence of arrhythmia remains unknown.
Methods. Twelve patients underwent modified total cavopulmonary connection. A prosthetic material was not used in 5 patients (group F) and was used in 7 patients (group P). A retrospective review of the perioperative electrocardiogram and ambulatory monitoring were performed.
Results. All patients revealed regular sinus rhythm before the operation. In the early postoperative period, the incidence of sinus node dysfunction was higher in group F than in group P (80% versus 28.6%). This difference no longer existed by hospital discharge (group F, 20%; group P, 14.3%). In the midterm follow-up period, sinus node dysfunction was detected in 4 patients of group F (80%) and 1 patient of group P (14.3%). Transient tachyarrhythmia was detected in 1 patient of group F and 3 patients of group P.
Conclusions. Modified total cavopulmonary connection without use of prosthetic material affected unfavorably the sinus node in the early and midterm postoperative period.
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Introduction
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Arrhythmia is known to be the major risk factor of morbidity and mortality after the Fontan type operation. Earlier investigators argued that postoperative arrhythmia was less frequent in total cavopulmonary connection (TCPC) than in atriopulmonary connection [1–3]. More recently, TCPC without use of prosthetic material appeared in the literature as a promising surgical procedure that would retain potential growth of the intraatrial tunnel [4–6]. In favor of the documented advantage, we have adopted the new surgical method since 1992. Although the short-term results of the new surgical method demonstrated a low incidence of arrhythmia [7], the midterm incidence of arrhythmia remains unknown. The purpose of this study was to identify whether the new surgical method affected favorably the incidence of arrhythmia during the midterm follow-up.
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Patients and methods
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Patients
Between November 1992 and October 1998, 12 patients underwent modified TCPC at Tokyo Metropolitan Children’s Hospital. A prosthetic material was not used in 5 patients (group F) and was used in 7 patients (group P). There were 5 boys and 7 girls. We made a retrospective review of the medical and surgical records with specific attention to the postoperative incidence of arrhythmia. All patients were evaluated by cardiac catheterization at a median of 14 months after the operation.
Surgical technique
Modified TCPC with or without use of the prosthetic material was performed through a median sternotomy. After cardiopulmonary bypass was instituted using bicaval and aortic cannulation, previous systemic-to-pulmonary shunt was ligated, if present. Myocardial protection was achieved by infusion of blood cardioplegic solution, containing 20 mmol/L potassium, into the aortic root. The heart was cooled with ice slush in such a manner as to keep the myocardial temperature less than 25°C. The right atrium was opened anterior and parallel to the interatrial groove. The incision extended from the root of the right atrial appendage to immediately superior to the junction between the right atrium and inferior caval vein. At both extents, the incision was extended posteriorly, thereby creating a flap of the atrial wall in group F (Fig 1A).
Particular care was taken not to extend the incision into the crista terminalis or sinus node area. The atrial septum was fully excised if present. The margin of the atrial flap was sutured down the orifice of the superior vena cava until it reached the posterior rim of the atrial septum. Inferiorly, the atrial flap was sutured around the orifice of the inferior vena cava and then along the posterior rim of the atrial septum, leaving the coronary sinus on the pulmonary venous atrial side to avoid potential injury to the conduction system (Fig 1B). Then the other margin of the atrial incision line was sutured to the epicardium of the repositioned atrial flap. These sutures were positioned next to the previous suture line so as to keep the stitches away from the sinus node (Fig 1C). After unclamping the aorta, the superior vena cava was transected at the level of the right pulmonary artery, or 1 cm superior to the cavo-atrial junction. The superior and inferior walls of the right pulmonary artery were incised and anastomosed with the corresponding ends of the transected superior vena cava. No prosthetic material was used during procedure. In the modified TCPC with use of prosthetic material or lateral tunnel procedure, on the other hand, a composite intraatrial tunnel was constructed using a baffle trimmed from a 10-mm Gore-Tex tube graft (W. L. Gore & Assoc, Flagstaff, AZ). The incision on the right atrium was almost the same as that of group F; however, posterior extension was not performed and the incision was made a little more posteriorly than in group F (Fig 2A).
The superior and inferior margins of the baffle were sutured around the orifices of the superior vena cava and the inferior vena cava, and the posteromedial margin to the posterior rim of atrial septum, leaving the coronary sinus on the pulmonary venous atrial side (Fig 2B). The anterior margin of the patch was incorporated into the suture closure of the atriotomy (Fig 2C). In both procedures, every effort was made to keep the surgical manipulation away from the sinus node artery, the sinus node itself, and the crista terminalis. No fenestration was created in any of the patients.
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Fig 1. (A) Surgical technique of modified total cavopulmonary connection without use of prosthetic material. The incision on the right atrium was made parallel to the interatrial groove, and then extended posteriorly. (B) The intraatrial tunnel was constructed by suturing the atrial flap around the orifice of the inferior vena cava, to the posterior atrial septal ridge, and around the orifice of the superior vena cava. (C) Then the anterior flap of the right atrium was brought down and sutured on the outer wall of the intraatrial tunnel to create a pulmonary venous chamber leaving the coronary sinus orifice in this chamber. (ASD = atrial septal defect; CS = coronary sinus orifice; SN = sinus node.)
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Fig 2. (A) Surgical technique of lateral tunnel method. The incision on the right atrium was made parallel to the interatrial groove and a little more posteriorly than for group F. (B) The intraatrial tunnel was constructed by placement of a partial tube of polytetrafluoroethylene (PTFE) from the inferior vena cava to the superior vena cava. (C) Then the anterior edge of the partial graft was incorporated into the suture line of the atriotomy to create a pulmonary venous chamber leaving the coronary sinus orifice in this chamber. (ASD = atrial septal defect; CS = coronary sinus orifice; SN = sinus node.)
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Arrhythmia
A retrospective review of the preoperative and postoperative electrocardiography as well as of the ambulatory monitoring was made to evaluate the incidence of arrhythmia. In all patients, repeated 12-lead electrocardiographic records were performed before and shortly after the operation, at the time of hospital discharge, and during the period of follow-up. In an attempt to determine the midterm incidence of arrhythmia, all patients underwent ambulatory electrocardiographic monitoring at a median of 42 months after the operation. Postoperative arrhythmia was grouped into three forms: (1) sinus node dysfunction, which included sinus bradycardia, ectopic atrial rhythm, predominant junctional rhythm, or sinus pause exceeding 2 seconds; (2) supraventricular tachycardia, which included atrial fibrillation, atrial flutter, ectopic atrial tachycardia, junctional ectopic tachycardia, or atrioventricular nodal reentrant tachycardia; and (3) any form of atrioventricular block.
Statistical analysis
Statistical analysis was performed with SPSS software (SPSS, Inc, Chicago, IL). Data were expressed as mean ± standard deviation. An unpaired Student’s t test was used to determine differences between the groups. Categorical variables were analyzed by use of Fisher’s exact test.
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Results
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Patient characteristics
The median age at the time of operation was 30 months (range, 20 to 144 months). The cardiac anomalies included tricuspid atresia (n = 5), pulmonary atresia with intact ventricular septum (n = 3), heterotaxy syndrome (n = 2), and others (n = 2; Table 1). All patients underwent previous palliative procedures including bidirectional cavopulmonary shunt having been performed on 4 patients. All but 2 patients (patients 4 and 10) underwent repeated sternotomy and pericardiotomy. An atrioventricular connection was converted to TCPC in a patient who developed myocardial dysfunction subsequent to the previous Björk procedure (patient 5). There were no significant differences between groups in age (group F, 53 ± 51.6 months; group P, 36 ± 19.3 months; p = 0.4378) and body weight (group F, 16.2 ± 10.3 kg; group P, 11.8 ± 2.8 kg; p = 0.3012). No death occurred during the midterm follow-up. None of the patients developed thromboembolic episodes.
Arrhythmia
Electrocardiographic records at the perioperative and follow-up periods were available in all patients, and the results are depicted in Figure 3.
All patients showed regular sinus rhythm before the operation. In the early postoperative period, 4 patients (80%) in group F developed sinus node dysfunction, with 2 of these developing junctional rhythm and the other 2 patients a combination of junctional rhythm and ectopic atrial rhythm. At the time of hospital discharge, however, 3 of the patients recovered regular sinus rhythm, with a consequent incidence of sinus node dysfunction of 20%. In group P, on the other hand, 2 patients (28.6%; odds ratio = 0.1; 95% confidence interval, 0.006 to 1.544; p = 0.2424 vs group F) developed sinus node dysfunction, with 1 of these developing ectopic atrial rhythm and the other patient, junctional rhythm. At the time of hospital discharge, however, the patient with junctional rhythm recovered regular sinus rhythm, with a consequent incidence of sinus node dysfunction of 14.3%. Although supraventricular tachycardia or premature contractions were observed in 1 patient of group F and 3 patients of group P, all episodes of tachyarrhythmia occurred exclusively during the early postoperative period and disappeared by the time of hospital discharge. None of the patients revealed atrial flutter or fibrillation during the hospital stay.
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Fig 3. Bar graph shows plot of the number of patients in normal sinus rhythm (NSR) and sinus node dysfunction (SND) in the preoperative period and during the period of follow-up after modified total cavopulmonary connection.
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All patients of both groups underwent ambulatory monitoring at a median of 42 months after the operation (range, 11 to 92 months). Four patients of group F (80%) developed sinus node dysfunction, with one of these having kept up ectopic atrial rhythm since the time of hospital discharge. The other 2 patients who had had regular sinus rhythm at the time of hospital discharge developed sinus bradycardia in association with sinus pauses, and the remaining patient, who had also had regular sinus rhythm at the time of hospital discharge, developed ectopic atrial rhythm. By contrast, in group P, sinus bradycardia was detected in only 1 patient (14.3%; odds ratio = 0.042; 95% confidence interval, 0.002 to 0.877; p = 0.072 versus group F), who had had regular sinus rhythm at the time of hospital discharge. Furthermore, a patient who had had ectopic atrial rhythm at the time of hospital discharge recovered regular sinus rhythm. None of the patients under investigation developed atrioventricular block, or atrial flutter or fibrillation. The frequency of the premature supraventricular contraction was 0.16% ± 0.23% of all beats during the investigation in group F and 0.15% ± 0.34% in group P (p = 0.9873). All patients with or without arrhythmia were free from symptoms without the need for medication.
Cardiac catheterization
Cardiac catheterization was performed in all patients at a median of 14 months (range, 3.8 to 29.6 months) after the operation. The cardiac index showed no significant difference between groups (group F, 3.17 ± 1.29 L · min-1 · m-2; group P, 2.97 ± 0.87 L · min-1 · m-2; p = 0.7811). The mean pressure of the pulmonary arteries and pulmonary vascular resistance index also showed no significant differences between groups, respectively (group F, 13 ± 1.2 mm Hg; group P, 14.5 ± 2.1 mm Hg; p = 0.7881; group F, 134.8 ± 19.2 dyne · s · cm-5 · m-2; group P, 148.7 ± 58.7 dyne · s · cm-5 · m-2; p = 0.6653). There was no pressure gradient or obstructed flow of blood across the anastomosis connecting both caval veins and the right pulmonary artery. The pressure curve of the intraatrial tunnel was pulsatile in all patients without regard to the operative method.
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Comment
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Progressively reduced incidence of arrhythmia after the Fontan operation owes much to the intricate modifications of the therapeutic strategy. These included staged palliation for the purpose of alleviation of the volume overload on the functioning ventricle and younger age at the time of operation. In addition, an increasing number of reports describe that TCPC is less prone to arrhythmia when compared with the atriopulmonary connection. This argument may in part be based on the evidence that the central venous pressure tended to be lower in TCPC than in atriopulmonary connection, with TCPC exerting less pressure load on the atrial wall [1–3]. As a consequence of these reports, TCPC has become accepted as a preferable palliative procedure for patients having a single functioning ventricle. In early years, a piece of prosthetic graft or patch was used as a baffle to separate the unified atrial cavity into chambers belonging to the systemic and pulmonary circulations (group P in our series) [8, 9]. During the past 10 years, numerous modified techniques have appeared in the literature for the purpose of optimal separation of the two circulatory systems at the atrial level. These included the atrial flap procedure in which the unified atrial cavity was divided by the repositioned atrial wall and, therefore, without use of the prosthetic material (group F in our series) [4–6]. As the systemic venous chamber was constructed only with the autologous material, a major advantage of this procedure was thought to be the potential growth of this chamber in correlation with somatic growth of the patient. Earlier reports dealing with short-term results of this procedure described the result as being promising, with a low incidence of postoperative arrhythmia [7]. However, our result was unequivocally different from the previous views, demonstrating that sinus node dysfunction was more prevalent in group F than in group P. Such a discrepancy caused us to infer that the higher incidence of arrhythmia in group F might be ascribed to the extensive incision and sutures of the right atrium, which were comparable with those of the Senning procedure [10]. With these considerations in mind, we made a detailed analysis of the 12-lead electrocardiographic records during the perioperative and follow-up periods, as well as of the ambulatory monitoring.
In contrast to the previous view that atrial tachyarrhythmia dominated the postoperative arrhythmia [1–3], recent studies indicated that sinus node dysfunction was the dominant feature after the Fontan operation [11]. Manning and colleagues [12] endorsed this view and claimed that a staged operation precipitated a higher incidence of sinus node dysfunction. More important, Shirai and colleagues [13] experienced a high incidence of sinus node dysfunction (44%) even after the extracardiac Fontan operation. Common to these reports was the implication that the repeated pericardiotomy was the predisposing factor of the sinus node dysfunction. Our result differed again from these reports, however, in that 6 of 7 patients of group P underwent repeated pericardiotomy with none of them developing sinus node dysfunction at the time of hospital discharge and only 1 exhibiting it during the midterm follow-up. Taking these observations together, we infer that an extensive manipulation of the right atrium for the construction of the cavocaval connection without use of the prosthetic material is the major risk factor for sinus node dysfunction. In fact, a high incidence of sinus node dysfunction in group F was comparable with that seen after the Mustard or Senning operations [14, 15], whereas a low incidence in group P was consistent with that seen (10% to 23%) in the midterm follow-up of the comparable procedure [12]. Although Cohen and colleagues [16] demonstrated that the surgical manipulation distant from the sinus node had no discernible effect on predisposition to the development of early sinus node dysfunction, their study dealt only with patients who underwent extracardiac Fontan or the lateral tunnel procedure subsequent to the hemi-Fontan procedure, and failed to deal with those who underwent the atrial flap procedure.
Another concern of the modified TCPC without use of the prosthetic material would be the progressive dilatation of the tunnel having a pressure higher than normal. Although TCPC is believed to be superior to the atriopulmonary connection with minimizing the area of the atrial wall that is subjected to high pressure, TCPC without use of the prosthetic material offsets this advantage by expanding the area of the atrial wall for the systemic venous tunnel. Therefore, the stepwise growth of the tunnel in correlation with age may mean that the atrial wall of the tunnel is overstretched. Such mechanical stress on the right atrial wall or the sinus node itself can well be another predisposing factor of the sinus node dysfunction.
Although all patients in our series remain in New York Heart Association functional class II or less, long-term consequences of sinus node dysfunction remain unknown. Loss of sinus rhythm and late development of arrhythmia were usually well tolerated. However, in the light of the facts that the longstanding arrhythmia after the Mustard or Senning operation predisposed patients to the progressive deterioration of cardiac function or sudden death, patients with sinus node dysfunction need close observation regardless of the presence or absence of clinical symptoms.
Against earlier investigations that showed a high incidence of malignant tachyarrhythmia including atrial flutter among patients who had undergone TCPC [1, 3], patients in our series did not show malignant tachyarrhythmia during the period of follow-up. Such discrepancy may be partly explained by an experimental study that clarified that the suture line by itself was a critical component in the flutter circuit by creating the conditions for slow conduction and unidirectional block [17]. In this study, the authors argued that, inasmuch as the intact crista terminalis minimized the conduction disturbance, the surgical incision or sutures kept away from the crista terminalis was the prerequisite to reduce the incidence of atrial tachyarrhythmia. The result of our surgical technique, in which sutures were placed along and away from the crista terminalis, validated this view.
Our study design has several limitations. The number of patients under investigation is small, and the follow-up period is as yet limited. Therefore, the close follow-up will clearly need to be continued. Should comparable studies be made in a larger series of patients, however, the controversy of the issue can be clarified further.
In summary, we experienced a high incidence of sinus node dysfunction after modified TCPC without use of prosthetic material. We did not, however, experience malignant tachyarrhythmias in the midterm follow-up. The result led us to infer that an extensive manipulation of the right atrium, not extending to the crista terminalis, has a predisposition to the development of sinus node dysfunction without subsequent appearance of malignant tachyarrhythmia.
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References
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Balaji S., Gewillig M., Bull C., de Leval M.R., Deanfield J.E. Arrhythmias after the Fontan procedure. Comparison of total cavopulmonary connection and atriopulmonary connection. Circulation 1991;84(Suppl 3):III162-III167.
-
Cecchin F., Johnsrude C.L., Perry J.C., Friedman R.A. Effect of age and surgical technique on symptomatic arrhythmias after the Fontan procedure. Am J Cardiol 1995;76:386-391.[Medline]
-
Gelatt M., Hamilton R.M., McCrindle B.W., et al. Risk factors for atrial tachyarrhythmias after the Fontan operation. J Am Coll Cardiol 1994;24:1735-1741.[Abstract]
-
Chu S., Leu M., Chuang C., Wang J. Total cavopulmonary connection: a modified technique without prosthetic material. J Card Surg 1991;6:294-298.[Medline]
-
Stark J., Kostelka M. The use of the right atrial flap in total cavopulmonary connection. J Card Surg 1991;6:362-366.[Medline]
-
Katogi T., Takeuchi S., Kudoh M., Iseki H., Onoguchi K., Kawada S. A modified technique in total cavopulmonary connection. Nippon Kyobu Geka Gakkai Zasshi 1992;40:983-986.[Medline]
-
Hashimoto K., Kurosawa H., Tanaka K., et al. Total cavopulmonary connection without the use of prosthetic material: technical considerations and hemodynamic consequences. J Thorac Cardiovasc Surg 1995;110:625-632.[Abstract/Free Full Text]
-
de Leval M.R., Kilner P., Gewillig M., Bull C. Total cavopulmonary connection: a logical alternative to atriopulmonary connection for complex Fontan operations. J Thorac Cardiovasc Surg 1988;96:682-695.[Abstract]
-
Jonas R.A., Castaneda A.L. Modified Fontan procedure. Atrial baffle and systemic venous to pulmonary artery anastomotic techniques. J Card Surg 1988;3:91-96.[Medline]
-
Kavey R.W., Gaum W.E., Byrum C.J., Smith F.C., Kveselis D.A. Loss of sinus rhythm after total cavopulmonary connection. Circulation 1995;92(Suppl 2):II304-II308.
-
Cohen M.I., Wernovsky G., Vetter V.L., et al. Sinus node function after a systematically staged Fontan procedure. Circulation 1998;98(Suppl 2):II352-II359.
-
Manning P.B., Mayer J.E., Wernovsky G., Fishberger S.B., Walsh E.P. Staged operation to Fontan increases the incidence of sinoatrial node dysfunction. J Thorac Cardiovasc Surg 1996;111:833-840.[Abstract/Free Full Text]
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Shirai L.K., Rosenthal D.N., Reitz B.A., Robbins R.C., Dubin A.M. Arrhythmias and thromboembolic complications after the extracardiac Fontan operation. J Thorac Cardiovasc Surg 1998;115:499-505.[Abstract/Free Full Text]
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Gewillig M., Cullen S., Merteus B., Lesaffre E., Deanfield J. Risk factors for arrhythmia and death after Mustard operation for simple transposition of the great arteries. Circulation 1991;84(Suppl 3):III187-III192.
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Helbing W.A., Hansen B., Ottenkamp J., et al. Long-term results of atrial connection for transposition of the great arteries. Comparison of Mustard and Senning operations. J Thorac Cardiovasc Surg 1994;108:363-372.[Abstract/Free Full Text]
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Cohen M.I., Bridges N.D., Gaynor J.W., et al. Modifications to the cavopulmonary anastomosis do not eliminate early sinus node dysfunction. J Thorac Cardiovasc Surg 2000;120:891-901.[Abstract/Free Full Text]
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Gandhi S.K., Bromberg B.I., Rodefeld M.D., et al. Lateral tunnel suture line variation reduces atrial flutter after the modified Fontan operation. Ann Thorac Surg 1996;61:1299-1309.[Abstract/Free Full Text]
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Abstract
Introduction
