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Repair of isolated multiple muscular ventricular septal defects: the septal obliteration technique
Repair of Isolated Multiple Muscular Ventricular Septal Defects: The Septal Obliteration Technique Michael D. Black, MD, Vinayak Shukla, MCh, Vivek Rao, MD, PhD, Jeffery F. Smallhorn, MD, and Robert M. Freedom, MD Division of Cardiothoracic Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
Background. Isolated multiple ventricular septal defects (mVSDs) remain a surgical challenge. The dilemma of whether to perform a complete repair ultimately rests with the surgeon, who must decide if all significant septal defects can be located. Avoidance of a pulmonary arterial band (as part of a two-stage repair) will negate the need for future pulmonary arterial reconstruction and will reduce the incidence of late right ventricular diastolic dysfunction. Methods. We performed a retrospective analysis of hospital and echocardiographic data of eight children who underwent a septal obliteration technique (SOT) as part of their correction of mVSDs (with and without coarctation of the aorta). Results. Eight children with a mean age of 10.5 months (range 1.5 to 36 months), and weight of 6.2 kg (range 2.1 to 13.5 kg), respectively, underwent correction of mVSDs. All had a single, large, perimembranous defect, additional VSDs within the muscular trebecular septum (jux-
taposed to the moderator band), and apical mVSDs. All VSDs were repaired via the right atrium, with avoidance of either a right or left ventriculotomy. The posterior and apical defects were excluded from the right ventricular cavity with a pericardial patch (SOT). The follow-up period remains limited to a mean of 20.9 months (8 to 39 months). Two children repaired with SOT had previous pulmonary artery bands (neonatal coarctation repair). All children were successfully discharged home with a mean postoperative Qp:Qs of 1.09:1. One pacemaker was required, but this child has since reverted back to normal sinus rythm. Conclusions. Our initial experience using the SOT in the treatment of apical VSDs as a component of isolated mVSDs has been rewarding. All children are currently alive, in normal sinus rhythm, and have no residual significant left-to-right shunts. (Ann Thorac Surg 2000;70:106 –10) © 2000 by The Society of Thoracic Surgeons
T
he presence of isolated multiple muscular ventricular septal defects (VSDs) remains a surgical challenge. The dilemma of whether to perform a complete onestage repair resides with the surgeon, who must decide, after all appropriate investigations, if all significant septal defects can be located and obliterated. Avoidance of pulmonary arterial banding (as part of a two-stage repair) remains appealing, as future pulmonary arterial reconstruction can be avoided as well as the consequential right ventricular hypertrophy and diastolic dysfunction. Numerous operations and surgical strategies can be found in the medical literature to address the treatment of multiple muscular VSDs. The myriad of approaches is testimony to the lack of superiority of any one method. Both the mortality and morbidity rates have been previously recognized as being greater than those associated with repair of a “single” large VSD. Recently, we have employed cardioscopy to assist in the diagnosis or repair of multiple VSDs in association with a septal obliteration pericardial patch [1]. We believe that further advances in surgical technology, particularly with respect to surgical
instrumentation and imaging equipment, will lead to an expanded role for videoscopic techniques used in the treatment of this and other complex congenital heart defects. In this report, we describe our early experience with the septal obliteration technique used for the repair of multiple muscular VSDs. In addition, we highlight the benefits of cardioscopy in the diagnosis and repair of such complex congenital heart defects.
Accepted for publication Jan 5, 2000.
Operative Technique
Address reprint requests to Dr Black, Department of Pediatric Cardiac Surgery, The Lucile Packard Children’s Hospital, Stanford University School of Medicine, Stanford, CA 94305-5407; e-mail: michael.black@ stanford.edu.
After standard induction of anesthesia and placement of monitoring lines, the patient was placed on cardiopulmonary bypass by cannulating the ascending aorta and both
© 2000 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Material and Methods A retrospective analysis from July 1, 1996, through September 1, 1998, was performed on eight children who underwent surgical repair of multiple muscular defects utilizing the septal obliteration technique (SOT) by one surgeon (M.D.B.). Only those children with isolated multiple muscular defects (with or without coarctation of the aorta) were included. All children had intraoperative echocardiography and oxygen saturations (taken from the right atrium and the pulmonary artery) to ascertain the degree of a possible residual intracardiac shunt.
0003-4975/00/$20.00 PII S0003-4975(00)01372-2
Ann Thorac Surg 2000;70:106 –10
vena cavae (the superior vena cava is cannulated via the right atrial appendage in order to prevent possible iatrogenic caval stenosis). A left ventricular vent is placed via the right superior pulmonary vein. The repair of aortic arch abnormalities with the avoidance of circulatory arrest has been optimized with a specially designed “selective” catheter. The technique has been detailed previously [2]. After the establishment of total cardiopulmonary bypass and the administration of antegrade blood cardioplegia, the caval snares are tightened. A right atriotomy is fashioned, and the atrial communication is located. If the atrial septum is intact, an atrial septotomy is created through the fossa ovalis.
Without Cardioscopy Via the tricuspid valve, the larger VSDs can usually be located. Via the perimembranous VSD and the atrial septal communication, gentle probing of the muscular septum is initiated to corroborate the preoperative studies. Outlet VSDs frequently require a pulmonary arteriotomy in order to optimize visualization as well as suture placement. The larger perimembranous defects are obliterated in the standard fashion first (interrupted plegetted braided polyester sutures), followed by closure of the midmuscular defects. The latter defects usually can be found directly beneath the moderator band. No child has required division of this muscular structure; instead, retraction usually allows for the placement of a single patch (even though it is common for the preoperative studies to demonstrate two jets of blood flow, above and below this muscular bar). The conduction system is in danger of either temporary or permanent damage passing between both patches. Once the general location of the multiple apical lesions is identified, an appropriate sized autologous pericardial patch pretreated in glutaraldehyde is positioned over the central region of the defects. Occasionally, several small trabeculae are transected in order for the patch to be placed as “flush” as possible with the remaining ventricular septum. Depending of the location of the defects, the patch may need to be fixed anteriorly, incorporating a portion of even the anterior right ventricle. Pledgetted sutures are strategically placed circumferentially in order to secure the patch and prevent diminution of the right ventricular cavity or inflow occlusion across the inlet septum. If chords to the tricuspid valve were transected, they are resecured at this time. The tricuspid valve is tested for functional competence by insufflation of saline into the right ventricle. This latter maneuver is useful for verifying obliteration of most of the shunt lesions, by observing how much, if any, saline returns from the left ventricular vent. The atrial septal defect is closed. The vent should now have a continuous column of blood without significant retained air. The left side of the heart is carefully deaired followed by removal of the aortic cross-clamp and systemic rewarming. Pacing wires are placed and tested regardless of the rhythm (even if normal sinus). If several ventricular patches are placed, a period of septal akinesis or even dyskinesis is common;
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therefore, the patient is maintained on inotropes for 48 hours until ventricular function returns to “normal.”
With Cardioscopy The techniques are similar to that described above except that via the large perimembranous VSD or the aortic root, the left side of the ventricular septum is inspected (Fig 1a). A single large defect in the apical region can sometimes be identified, permitting novel closure strategies: (1) the defect can be illuminated (Fig 1A) and approached with the SOT from the right (Fig 1B) (n ⫽ 2); or (2) a silk suture can be passed, demonstrating the extreme upper and lower margins of the defect (n ⫽ 2). After intraoperative transesophageal echocardiography, oxygen saturations are sampled from both the superior vena cava and the pulmonary artery. Although the echocardiographic findings may demonstrate, at first glance, what appears to be a residual significant shunt, experience has demonstrated the passage of blood across the septum into a “blind-ending” apical neochamber (Fig 1C). There have been no physiologically significant residual shunt lesions in any of the patients. Figure 2 illustrates echocardiographic positioning of the pericardial SOT patch.
Results Table 1 illustrates the demographic data as well as diagnosis and postoperative shunt fractions. Eight children with a mean age of 10.5 months (1.5 to 36 months) and a mean weight of 6.2 kg (2.1 to 13.5 kg) underwent correction of isolated multiple muscular VSDs. All had in common a single large perimembranous defect with apical VSDs. Additional septal defects within the muscular trebecular septum were present in all children (usually in juxtaposition to the moderator band). All defects were repaired via the right atrium, with avoidance of either a right or left ventriculotomy. The posterior and apical defects were excluded from the right ventricular cavity with a pericardial patch (SOT). The follow-up period remains limited to a mean of 20.9 months (8 to 39 months). Two children had previous pulmonary bands placed in combination with neonatal coarctation repair; however, both are included in this study as they were corrected with an SOT technique. Four children had repair of either transverse arch hypoplasia or coarctation of the aorta (two previously banded) without circulatory arrest. All children were successfully discharged home. One pacemaker was required, but this child has since reverted back to normal sinus rhythm.
Comment The surgical management of children with multiple VSDs continues to be difficult. The decision to embark upon a one-stage repair resides with the surgeon who must decide, after careful and complete preoperative investigations, whether all significant defects can be abolished. If the repair is unsuccessful (ie, postoperative residual shunt of ⬎ 1.5:1) with a prolonged “pump” run
108
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Fig 1. (A) The placement of the cardioscope via the aortic root with illumination of the septal defects from the left ventricle. (B) Closure of the defects with three distinct patches (perimembranous, mid-muscular (split by the moderator band), and the apical SOT). (C) Artistic interpretation of how the echocardiogram may continue to visualize the “noncommunicating” left-to-right ventricular shunt at the “blind-ending” neoapical chamber created by the SOT patch.
and associated myocardial ischemia, a difficult postoperative course and possibly death can be expected. The alternatives may include a two-stage repair or the intraoperative deployment of a transseptal device. A twostaged repair, although appealing, may induce severe hypertrophy of the right ventricle with severe diastolic noncompliance. Postoperative right ventricular failure, prolonged chest-tube drainage, and dysrrhythmias may occur. In addition, distortion of the branch pulmonary
arteries after a period of prolonged banding may occur, necessitating their repair at the time of the debanding. While the intraoperative deployment of a trans-septal occluding device (limited percutaneous deployment by the caliber of the femoral vessels) has been reported and remains appealing, its popularity has been limited to lack of expertise and availability [3]. In the original 10 children reported, device deployment was unacceptable due to an “inadequate septal rim” (n ⫽ 1). There were early (n ⫽ 3)
Ann Thorac Surg 2000;70:106 –10
Fig 2. The preoperative image (A) demonstrates large muscular ventricular septal defect(s) towards the apex, below the moderator band. The postoperative image (B) shows the apex of the right ventricle was obliterated to close the muscular defect. Note how smooth the new apical portion is in comparison with the preoperative figure with the dense right ventricular trabeculations at the apex. (LA ⫽ left atrium; LV ⫽ left ventricle; RA ⫽ right atrium; RV ⫽ right ventricle.)
deaths secondary to poor ventricular function. In the six survivors, 50% were found to have a Qp:Qs greater than 2.0:1 after device closure. There was one late death in this latter subgroup. Therefore, the overall mortality rate was 44%. However, with technological improvement and better patient selection, improved results can be anticipated. As such, we have found the septal obliteration technique rewarding in tackling multiple apical and posterior muscular VSDs. The technique, at least in theory, remains similar to that proposed by the interventional cardiologists in favor of device closure. The obliteration of the passage of blood across the septum is accomplished without the closure of each and every defect. A further advantage of the one-stage surgical repair re-
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mains the ability for simultaneous closure of other large (perimembranous and midmuscular) defects. Muscular defects of the ventricular septum may be single or multiple, with four or more communications giving the septum a “Swiss cheese” appearance. Trebecular VSDs have been traditionally divided into high, mid, and low or apical VSDs. Most VSDs are in the area of the membranous portion of the ventricular septum in close relationship to the aortic or tricuspid valves. However, muscular VSDs are often located behind the hypertrophied trabecular carnae of papillary muscles. The management of multiple muscular defects in the lower part of the ventricular septum has been less than satisfactory. This may be due to the combination of a limited accessibility and difficulty in identification. We have recently employed the cardioscope for identification of defects from the left side of the ventricular septum via the aortic root when exposure was limited via the right atrium. Although preliminary, we feel that this technique will have increased future applications by allowing identification and closure via the left side or by the illumination of the area that requires SOT application from the right side. Although various surgical approaches have been suggested as being superior (ie, right atriotomy, right or left ventriculotomy) and the “sandwich technique” suggested by Kirklin and utilized by Breckenridge and colleagues, the myriad of techniques is testimony to the lack of superiority of any one technique [4 –9]. Multiple VSDs have been reported in 2% to 18% of the total number of patients with VSDs [6]. Incomplete or insecure closure remains a significant reason for the high surgical mortality of multiple VSDs [4, 10 –12]. In fact, death was directly related to residual VSDs in over one-half of the patients, with associated pulmonary hypertension and right ventricular failure [13]. The unsatisfactory results obtained with the two-stage approach, and the concomitant improved reported mortality for primary repair, stimulated us to look for alternative methods to improve the localization and obliteration of multiple VSD’s during the one-staged repair [14]. McNicholas and associates reported that the total operative mortality from the time of presentation, with or without operation, for patients with multiple VSDs was 20% as opposed to 4% for children with single VSDs [15]. Fox and associates reported similar results in infants with intractable heart failure from multiple VSDs treated by pulmonary banding (mortality 8.3%) and subsequent debanding and multiple VSD closure (mortality 27%). Where operation for multiple VSDs was delayed beyond 1 year of age, primary total correction was performed with a mortality of 18% [10]. In the present era, Serraf and associates provide further evidence that low trabecular VSDs remains a significant risk factor for morbidity (ie, death and residual VSDs) ( p ⬍ 0.01). Although their early mortality rate remained low (7.7%), the reoperative mortality rate for residual defects remained high (33%) [13]. We suggest that pulmonary arterial banding in infancy should be reserved for those children with contraindica-
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Table 1. Demographic Data Patient 1 2 3 4 5 6 7 8
a
Age (months)
Weight (kg)
0.5 17.0 1.5 5.0 10.0 7.5 3.0 4.0 1.0 36
2.1 7.0 2.1 4.9 5.9 6.8 5.1 4.5 13.5
Diagnosis/Operation “Swiss cheese” septum/TAH/PAB pacemaker Multiple muscular VSDs/ASD/PDA Multiple muscular VSDs/ASD/PDA Multiple muscular VSDs/RVMB/PDA/Trisomy 21 Multiple muscular VSDs/PDA/coarctationa Shone’s syndrome/TAHa Multiple muscular VSDs/ASD Multiple muscular VSDs/s/p PAB/coarctation repair (outside hospital)/reconstruction of branch PAs
Postop Qp:Qs 1.02:1.0 1.3:1.0 1.0:1.0 1.01:1.0 1.02:1.0 1.0:1.0 1.25:1.0 1.1:1.0
Denotes repair of aortic arch without period of circulatory arrest.
ASD ⫽ atrial septal defect; ventricular muscle bundles;
PAB ⫽ pulmonary artery band; PAs ⫽ pulmonary arteries; PDA ⫽ patent ductus arteriosus; TAH ⫽ transverse arch hypoplasia; VSDs ⫽ ventricular septal defects.
tions to anticoagulation and thus cardiopulmonary bypass, complex associated congenital lesions that may in themselves require a period of palliation or a “watering can” type of spongiform ventricle. Intracardiac repair can be delayed to about 2 years of age [15]. Our initial experience using the septal obliteration technique in the treatment of apical VSDs as a component of isolated multiple VSDs has been rewarding. All children are currently alive, in normal sinus rhythm, and have no residual significant left-to-right shunts. We have a final word of caution regarding the intraoperative echocardiographic interpretation of a significant residual postrepair shunts: if in doubt, determine the postrepair intraoperative Qp:Qs. Experience has demonstrated the passage of blood remains limited by the SOT patch into the “blind-ending” apical neochamber (Fig 1C). We thank Bayard “Butch” Colyear (visual art services, Stanford University) for his artistic interpretation of the septal obliteration technique (Fig 1).
References 1. Rao V, Freedom RM, Black MD. Minimally invasive surgery with cardioscopy for congential heart defects. Ann Thorac Surg 1999;68:1742–5. 2. Black MD, Bissonette B. Selective cerebral perfusion: an alternative approach to cerebral protection in neonates/infants with complex cardiac procedures requiring aortic arch reconstruction [Abstract]. Can J Cardiol 1998;14(Suppl F):87. 3. Fishberger SB, Bridges ND, Keane JF, et al. Intraoperative device closure of ventricular septal defects. Circulation 1993; 88(5 Pt 2):205–9.
RVMB ⫽ right
4. Kirklin JK, Castaneda AR, Keane JF, Fellows KE, Norwood WI. Surgical management of multiple ventricular septal defects. J Thorac Cardiovasc Surg 1980;80:485–93. 5. Breckenridge IM, Stark J, Waterston DJ, Bonham-Carter RE. Multiple ventricular septal defects. Ann Thorac Surg 1972; 13:128–36. 6. Aaron BL, Lower RR. Muscular ventricular septal defect repair made easy. Ann Thorac Surg 1975;19:568–70. 7. Singh AK, de Leval MR, Stark J. Left ventriculotomy for closure of muscular ventricular septal defects. Treatment of choice. Ann Thorac Surg 1977;186:577– 80. 8. Zavanella C, Matsuda H, Jara F, Subramanian S. Left ventricular approach to multiple ventricular septal defects. Ann Thorac Surg 1977;24:537– 43. 9. Griffiths SP, Turi GK, Ellis K, et al. Muscular ventricular septal defects repaired with left ventriculotomy. Amer J Cardiol 1981;48:877– 86. 10. Fox KM, Patel RG, Graham GR, et al. Multiple and single ventricular septal defect. A clinical and haemodynamic comparison. Br Heart J 1978;40:141– 6. 11. Blackstone EH, Kirklin JW, Bradley EL, et al. Optimal age and results in repair of large ventricular septal defects. J Thorac Cardiovasc Surg 1976;72:661–79. 12. Rein JG, Fred MD, Norwood WI, Castaneda AR. Early and late results of closure of ventricular septal defect in infancy. Ann Thorac Surg 1977;24:19–26. 13. Serraf A, Lacour-Gayet F, Bruniaux J, et al. Surgical management of isolated multiple ventricular septal defects. J Thorac Cardiovasc Surg 1992;103:437– 43. 14. Rizzoli G, Blackstone EH, Kirklin JW, Pacificao AD, Bargeron LM. Incremental risk factors in hospital mortality after repair of ventricular septal defects. J Thorac Cardiovasc Surg 1980;80:494 –505. 15. McNicholas K, DeLeval M, Stark J, Taylor JFN, MaCartney FJ. Surgical treatment of ventricular septal defect in infancy. Primary repair versus banding of pulmonary artery and later repair. Br Heart J 1979;41:133– 8.
Background. Isolated multiple ventricular septal defects (mVSDs) remain a surgical challenge. The dilemma of whether to perform a complete repair ultimately rests with the surgeon, who must decide if all significant septal defects can be located. Avoidance of a pulmonary arterial band (as part of a two-stage repair) will negate the need for future pulmonary arterial reconstruction and will reduce the incidence of late right ventricular diastolic dysfunction. Methods. We performed a retrospective analysis of hospital and echocardiographic data of eight children who underwent a septal obliteration technique (SOT) as part of their correction of mVSDs (with and without coarctation of the aorta). Results. Eight children with a mean age of 10.5 months (range 1.5 to 36 months), and weight of 6.2 kg (range 2.1 to 13.5 kg), respectively, underwent correction of mVSDs. All had a single, large, perimembranous defect, additional VSDs within the muscular trebecular septum (jux-
taposed to the moderator band), and apical mVSDs. All VSDs were repaired via the right atrium, with avoidance of either a right or left ventriculotomy. The posterior and apical defects were excluded from the right ventricular cavity with a pericardial patch (SOT). The follow-up period remains limited to a mean of 20.9 months (8 to 39 months). Two children repaired with SOT had previous pulmonary artery bands (neonatal coarctation repair). All children were successfully discharged home with a mean postoperative Qp:Qs of 1.09:1. One pacemaker was required, but this child has since reverted back to normal sinus rythm. Conclusions. Our initial experience using the SOT in the treatment of apical VSDs as a component of isolated mVSDs has been rewarding. All children are currently alive, in normal sinus rhythm, and have no residual significant left-to-right shunts. (Ann Thorac Surg 2000;70:106 –10) © 2000 by The Society of Thoracic Surgeons
T
he presence of isolated multiple muscular ventricular septal defects (VSDs) remains a surgical challenge. The dilemma of whether to perform a complete onestage repair resides with the surgeon, who must decide, after all appropriate investigations, if all significant septal defects can be located and obliterated. Avoidance of pulmonary arterial banding (as part of a two-stage repair) remains appealing, as future pulmonary arterial reconstruction can be avoided as well as the consequential right ventricular hypertrophy and diastolic dysfunction. Numerous operations and surgical strategies can be found in the medical literature to address the treatment of multiple muscular VSDs. The myriad of approaches is testimony to the lack of superiority of any one method. Both the mortality and morbidity rates have been previously recognized as being greater than those associated with repair of a “single” large VSD. Recently, we have employed cardioscopy to assist in the diagnosis or repair of multiple VSDs in association with a septal obliteration pericardial patch [1]. We believe that further advances in surgical technology, particularly with respect to surgical
instrumentation and imaging equipment, will lead to an expanded role for videoscopic techniques used in the treatment of this and other complex congenital heart defects. In this report, we describe our early experience with the septal obliteration technique used for the repair of multiple muscular VSDs. In addition, we highlight the benefits of cardioscopy in the diagnosis and repair of such complex congenital heart defects.
Accepted for publication Jan 5, 2000.
Operative Technique
Address reprint requests to Dr Black, Department of Pediatric Cardiac Surgery, The Lucile Packard Children’s Hospital, Stanford University School of Medicine, Stanford, CA 94305-5407; e-mail: michael.black@ stanford.edu.
After standard induction of anesthesia and placement of monitoring lines, the patient was placed on cardiopulmonary bypass by cannulating the ascending aorta and both
© 2000 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Material and Methods A retrospective analysis from July 1, 1996, through September 1, 1998, was performed on eight children who underwent surgical repair of multiple muscular defects utilizing the septal obliteration technique (SOT) by one surgeon (M.D.B.). Only those children with isolated multiple muscular defects (with or without coarctation of the aorta) were included. All children had intraoperative echocardiography and oxygen saturations (taken from the right atrium and the pulmonary artery) to ascertain the degree of a possible residual intracardiac shunt.
0003-4975/00/$20.00 PII S0003-4975(00)01372-2
Ann Thorac Surg 2000;70:106 –10
vena cavae (the superior vena cava is cannulated via the right atrial appendage in order to prevent possible iatrogenic caval stenosis). A left ventricular vent is placed via the right superior pulmonary vein. The repair of aortic arch abnormalities with the avoidance of circulatory arrest has been optimized with a specially designed “selective” catheter. The technique has been detailed previously [2]. After the establishment of total cardiopulmonary bypass and the administration of antegrade blood cardioplegia, the caval snares are tightened. A right atriotomy is fashioned, and the atrial communication is located. If the atrial septum is intact, an atrial septotomy is created through the fossa ovalis.
Without Cardioscopy Via the tricuspid valve, the larger VSDs can usually be located. Via the perimembranous VSD and the atrial septal communication, gentle probing of the muscular septum is initiated to corroborate the preoperative studies. Outlet VSDs frequently require a pulmonary arteriotomy in order to optimize visualization as well as suture placement. The larger perimembranous defects are obliterated in the standard fashion first (interrupted plegetted braided polyester sutures), followed by closure of the midmuscular defects. The latter defects usually can be found directly beneath the moderator band. No child has required division of this muscular structure; instead, retraction usually allows for the placement of a single patch (even though it is common for the preoperative studies to demonstrate two jets of blood flow, above and below this muscular bar). The conduction system is in danger of either temporary or permanent damage passing between both patches. Once the general location of the multiple apical lesions is identified, an appropriate sized autologous pericardial patch pretreated in glutaraldehyde is positioned over the central region of the defects. Occasionally, several small trabeculae are transected in order for the patch to be placed as “flush” as possible with the remaining ventricular septum. Depending of the location of the defects, the patch may need to be fixed anteriorly, incorporating a portion of even the anterior right ventricle. Pledgetted sutures are strategically placed circumferentially in order to secure the patch and prevent diminution of the right ventricular cavity or inflow occlusion across the inlet septum. If chords to the tricuspid valve were transected, they are resecured at this time. The tricuspid valve is tested for functional competence by insufflation of saline into the right ventricle. This latter maneuver is useful for verifying obliteration of most of the shunt lesions, by observing how much, if any, saline returns from the left ventricular vent. The atrial septal defect is closed. The vent should now have a continuous column of blood without significant retained air. The left side of the heart is carefully deaired followed by removal of the aortic cross-clamp and systemic rewarming. Pacing wires are placed and tested regardless of the rhythm (even if normal sinus). If several ventricular patches are placed, a period of septal akinesis or even dyskinesis is common;
BLACK ET AL SEPTAL OBLITERATION TECHNIQUE
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therefore, the patient is maintained on inotropes for 48 hours until ventricular function returns to “normal.”
With Cardioscopy The techniques are similar to that described above except that via the large perimembranous VSD or the aortic root, the left side of the ventricular septum is inspected (Fig 1a). A single large defect in the apical region can sometimes be identified, permitting novel closure strategies: (1) the defect can be illuminated (Fig 1A) and approached with the SOT from the right (Fig 1B) (n ⫽ 2); or (2) a silk suture can be passed, demonstrating the extreme upper and lower margins of the defect (n ⫽ 2). After intraoperative transesophageal echocardiography, oxygen saturations are sampled from both the superior vena cava and the pulmonary artery. Although the echocardiographic findings may demonstrate, at first glance, what appears to be a residual significant shunt, experience has demonstrated the passage of blood across the septum into a “blind-ending” apical neochamber (Fig 1C). There have been no physiologically significant residual shunt lesions in any of the patients. Figure 2 illustrates echocardiographic positioning of the pericardial SOT patch.
Results Table 1 illustrates the demographic data as well as diagnosis and postoperative shunt fractions. Eight children with a mean age of 10.5 months (1.5 to 36 months) and a mean weight of 6.2 kg (2.1 to 13.5 kg) underwent correction of isolated multiple muscular VSDs. All had in common a single large perimembranous defect with apical VSDs. Additional septal defects within the muscular trebecular septum were present in all children (usually in juxtaposition to the moderator band). All defects were repaired via the right atrium, with avoidance of either a right or left ventriculotomy. The posterior and apical defects were excluded from the right ventricular cavity with a pericardial patch (SOT). The follow-up period remains limited to a mean of 20.9 months (8 to 39 months). Two children had previous pulmonary bands placed in combination with neonatal coarctation repair; however, both are included in this study as they were corrected with an SOT technique. Four children had repair of either transverse arch hypoplasia or coarctation of the aorta (two previously banded) without circulatory arrest. All children were successfully discharged home. One pacemaker was required, but this child has since reverted back to normal sinus rhythm.
Comment The surgical management of children with multiple VSDs continues to be difficult. The decision to embark upon a one-stage repair resides with the surgeon who must decide, after careful and complete preoperative investigations, whether all significant defects can be abolished. If the repair is unsuccessful (ie, postoperative residual shunt of ⬎ 1.5:1) with a prolonged “pump” run
108
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Fig 1. (A) The placement of the cardioscope via the aortic root with illumination of the septal defects from the left ventricle. (B) Closure of the defects with three distinct patches (perimembranous, mid-muscular (split by the moderator band), and the apical SOT). (C) Artistic interpretation of how the echocardiogram may continue to visualize the “noncommunicating” left-to-right ventricular shunt at the “blind-ending” neoapical chamber created by the SOT patch.
and associated myocardial ischemia, a difficult postoperative course and possibly death can be expected. The alternatives may include a two-stage repair or the intraoperative deployment of a transseptal device. A twostaged repair, although appealing, may induce severe hypertrophy of the right ventricle with severe diastolic noncompliance. Postoperative right ventricular failure, prolonged chest-tube drainage, and dysrrhythmias may occur. In addition, distortion of the branch pulmonary
arteries after a period of prolonged banding may occur, necessitating their repair at the time of the debanding. While the intraoperative deployment of a trans-septal occluding device (limited percutaneous deployment by the caliber of the femoral vessels) has been reported and remains appealing, its popularity has been limited to lack of expertise and availability [3]. In the original 10 children reported, device deployment was unacceptable due to an “inadequate septal rim” (n ⫽ 1). There were early (n ⫽ 3)
Ann Thorac Surg 2000;70:106 –10
Fig 2. The preoperative image (A) demonstrates large muscular ventricular septal defect(s) towards the apex, below the moderator band. The postoperative image (B) shows the apex of the right ventricle was obliterated to close the muscular defect. Note how smooth the new apical portion is in comparison with the preoperative figure with the dense right ventricular trabeculations at the apex. (LA ⫽ left atrium; LV ⫽ left ventricle; RA ⫽ right atrium; RV ⫽ right ventricle.)
deaths secondary to poor ventricular function. In the six survivors, 50% were found to have a Qp:Qs greater than 2.0:1 after device closure. There was one late death in this latter subgroup. Therefore, the overall mortality rate was 44%. However, with technological improvement and better patient selection, improved results can be anticipated. As such, we have found the septal obliteration technique rewarding in tackling multiple apical and posterior muscular VSDs. The technique, at least in theory, remains similar to that proposed by the interventional cardiologists in favor of device closure. The obliteration of the passage of blood across the septum is accomplished without the closure of each and every defect. A further advantage of the one-stage surgical repair re-
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mains the ability for simultaneous closure of other large (perimembranous and midmuscular) defects. Muscular defects of the ventricular septum may be single or multiple, with four or more communications giving the septum a “Swiss cheese” appearance. Trebecular VSDs have been traditionally divided into high, mid, and low or apical VSDs. Most VSDs are in the area of the membranous portion of the ventricular septum in close relationship to the aortic or tricuspid valves. However, muscular VSDs are often located behind the hypertrophied trabecular carnae of papillary muscles. The management of multiple muscular defects in the lower part of the ventricular septum has been less than satisfactory. This may be due to the combination of a limited accessibility and difficulty in identification. We have recently employed the cardioscope for identification of defects from the left side of the ventricular septum via the aortic root when exposure was limited via the right atrium. Although preliminary, we feel that this technique will have increased future applications by allowing identification and closure via the left side or by the illumination of the area that requires SOT application from the right side. Although various surgical approaches have been suggested as being superior (ie, right atriotomy, right or left ventriculotomy) and the “sandwich technique” suggested by Kirklin and utilized by Breckenridge and colleagues, the myriad of techniques is testimony to the lack of superiority of any one technique [4 –9]. Multiple VSDs have been reported in 2% to 18% of the total number of patients with VSDs [6]. Incomplete or insecure closure remains a significant reason for the high surgical mortality of multiple VSDs [4, 10 –12]. In fact, death was directly related to residual VSDs in over one-half of the patients, with associated pulmonary hypertension and right ventricular failure [13]. The unsatisfactory results obtained with the two-stage approach, and the concomitant improved reported mortality for primary repair, stimulated us to look for alternative methods to improve the localization and obliteration of multiple VSD’s during the one-staged repair [14]. McNicholas and associates reported that the total operative mortality from the time of presentation, with or without operation, for patients with multiple VSDs was 20% as opposed to 4% for children with single VSDs [15]. Fox and associates reported similar results in infants with intractable heart failure from multiple VSDs treated by pulmonary banding (mortality 8.3%) and subsequent debanding and multiple VSD closure (mortality 27%). Where operation for multiple VSDs was delayed beyond 1 year of age, primary total correction was performed with a mortality of 18% [10]. In the present era, Serraf and associates provide further evidence that low trabecular VSDs remains a significant risk factor for morbidity (ie, death and residual VSDs) ( p ⬍ 0.01). Although their early mortality rate remained low (7.7%), the reoperative mortality rate for residual defects remained high (33%) [13]. We suggest that pulmonary arterial banding in infancy should be reserved for those children with contraindica-
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Table 1. Demographic Data Patient 1 2 3 4 5 6 7 8
a
Age (months)
Weight (kg)
0.5 17.0 1.5 5.0 10.0 7.5 3.0 4.0 1.0 36
2.1 7.0 2.1 4.9 5.9 6.8 5.1 4.5 13.5
Diagnosis/Operation “Swiss cheese” septum/TAH/PAB pacemaker Multiple muscular VSDs/ASD/PDA Multiple muscular VSDs/ASD/PDA Multiple muscular VSDs/RVMB/PDA/Trisomy 21 Multiple muscular VSDs/PDA/coarctationa Shone’s syndrome/TAHa Multiple muscular VSDs/ASD Multiple muscular VSDs/s/p PAB/coarctation repair (outside hospital)/reconstruction of branch PAs
Postop Qp:Qs 1.02:1.0 1.3:1.0 1.0:1.0 1.01:1.0 1.02:1.0 1.0:1.0 1.25:1.0 1.1:1.0
Denotes repair of aortic arch without period of circulatory arrest.
ASD ⫽ atrial septal defect; ventricular muscle bundles;
PAB ⫽ pulmonary artery band; PAs ⫽ pulmonary arteries; PDA ⫽ patent ductus arteriosus; TAH ⫽ transverse arch hypoplasia; VSDs ⫽ ventricular septal defects.
tions to anticoagulation and thus cardiopulmonary bypass, complex associated congenital lesions that may in themselves require a period of palliation or a “watering can” type of spongiform ventricle. Intracardiac repair can be delayed to about 2 years of age [15]. Our initial experience using the septal obliteration technique in the treatment of apical VSDs as a component of isolated multiple VSDs has been rewarding. All children are currently alive, in normal sinus rhythm, and have no residual significant left-to-right shunts. We have a final word of caution regarding the intraoperative echocardiographic interpretation of a significant residual postrepair shunts: if in doubt, determine the postrepair intraoperative Qp:Qs. Experience has demonstrated the passage of blood remains limited by the SOT patch into the “blind-ending” apical neochamber (Fig 1C). We thank Bayard “Butch” Colyear (visual art services, Stanford University) for his artistic interpretation of the septal obliteration technique (Fig 1).
References 1. Rao V, Freedom RM, Black MD. Minimally invasive surgery with cardioscopy for congential heart defects. Ann Thorac Surg 1999;68:1742–5. 2. Black MD, Bissonette B. Selective cerebral perfusion: an alternative approach to cerebral protection in neonates/infants with complex cardiac procedures requiring aortic arch reconstruction [Abstract]. Can J Cardiol 1998;14(Suppl F):87. 3. Fishberger SB, Bridges ND, Keane JF, et al. Intraoperative device closure of ventricular septal defects. Circulation 1993; 88(5 Pt 2):205–9.
RVMB ⫽ right
4. Kirklin JK, Castaneda AR, Keane JF, Fellows KE, Norwood WI. Surgical management of multiple ventricular septal defects. J Thorac Cardiovasc Surg 1980;80:485–93. 5. Breckenridge IM, Stark J, Waterston DJ, Bonham-Carter RE. Multiple ventricular septal defects. Ann Thorac Surg 1972; 13:128–36. 6. Aaron BL, Lower RR. Muscular ventricular septal defect repair made easy. Ann Thorac Surg 1975;19:568–70. 7. Singh AK, de Leval MR, Stark J. Left ventriculotomy for closure of muscular ventricular septal defects. Treatment of choice. Ann Thorac Surg 1977;186:577– 80. 8. Zavanella C, Matsuda H, Jara F, Subramanian S. Left ventricular approach to multiple ventricular septal defects. Ann Thorac Surg 1977;24:537– 43. 9. Griffiths SP, Turi GK, Ellis K, et al. Muscular ventricular septal defects repaired with left ventriculotomy. Amer J Cardiol 1981;48:877– 86. 10. Fox KM, Patel RG, Graham GR, et al. Multiple and single ventricular septal defect. A clinical and haemodynamic comparison. Br Heart J 1978;40:141– 6. 11. Blackstone EH, Kirklin JW, Bradley EL, et al. Optimal age and results in repair of large ventricular septal defects. J Thorac Cardiovasc Surg 1976;72:661–79. 12. Rein JG, Fred MD, Norwood WI, Castaneda AR. Early and late results of closure of ventricular septal defect in infancy. Ann Thorac Surg 1977;24:19–26. 13. Serraf A, Lacour-Gayet F, Bruniaux J, et al. Surgical management of isolated multiple ventricular septal defects. J Thorac Cardiovasc Surg 1992;103:437– 43. 14. Rizzoli G, Blackstone EH, Kirklin JW, Pacificao AD, Bargeron LM. Incremental risk factors in hospital mortality after repair of ventricular septal defects. J Thorac Cardiovasc Surg 1980;80:494 –505. 15. McNicholas K, DeLeval M, Stark J, Taylor JFN, MaCartney FJ. Surgical treatment of ventricular septal defect in infancy. Primary repair versus banding of pulmonary artery and later repair. Br Heart J 1979;41:133– 8.