J Thorac Cardiovasc Surg 1997;113:618-619
© 1997 Mosby, Inc.
Is left ventricular outflow tract obstruction really relieved on long-term follow-up?
Vaughn A. Starnes, MD
Children's Hospital of Los Angeles
Division of Cardiothoracic Surgery
USC School of Medicine
1510 San Pablo St., Suite 415
Los Angeles, CA 90033-4612
Reply to the Editor:
I read Dr. Hisatomi's case report with interest. Dr. Hisatomi's patient had a ventricular septal defect (VSD) and subaortic stenosis as a result of the realignment of the infundibular septum. Although her anatomy is similar to that of the neonates we reported on with interrupted aortic arch and subaortic stenosis, she clearly belongs to a different subset of patients. Dr. Hisatomi describes the successful repair of the VSD with the attachment of the VSD sutures along the left side of the superior margin of the infundibular septum. By downsizing the patch and anchoring the superior margin of the patch to the left of the septum, Dr. Hisatomi successfully closed the VSD and relieved the left ventricular outflow tract obstruction that existed before the operation. In follow-up, he noted the recurrence of the subaortic gradient to a level of 80 mm Hg. He now concludes that he will need to reoperate to relieve the subaortic obstruction and theorizes that he should have performed this procedure at the first operation.
I agree with Dr. Hisatomi's conclusion that another operation is needed to relieve the subaortic obstruction. However, I disagree with his deduction based on one case that his previous operation was unsuccessful. In review of the literature, the recurrence rate of subaortic obstruction after different forms of repair, including resection of the infundibular membrane, has varied from 17% to 67% (peak gradient > 25 mm Hg).
1-4 In our report, there was no early or midterm (14 months) recurrence in a group of neonates with subaortic areas with Z values greater than 4 deviations below the normal values. I believe this case report is of interest, but it would not persuade me to change my technique. Further, VSD closure without resection of the infundibulum, placing the sutures on the left superior margin of the VSD and downsizing the patch, has permitted excellent survival (100%) in our current series with good midterm relief of subaortic stenosis. A risk factor for the recurrence of aortic and subaortic obstruction may be the size of the aortic valve anulus and whether or not it is bicuspid. We have noted recurrence of obstruction in three infants referred to our center who have had aortic annular dimensions less than 5 mm and a bicuspid valve at the initial operation. We are following this group of infants with interest.
In conclusion, these infants represent a difficult subset of patients. We need to define a more consistent way of repairing the VSD with acceptable morbidity and mortality that can be reproduced by many different centers. I believe the operation advocated in our article can be reproduced by many centers with good results.
12/8/78755
References
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Van Praagh R, Bernhard WF, Rosenthal A, Parisi LF, Fyler DF. Interrupted aortic arch: surgical treatment. Am J Cardiol 1971:27:200-11.
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Jonas RA, Quaegebeur JM, Kirklin JW, Blackstone EH, Daicoff G, the Congenital Heart Surgeons Society. Outcomes in patients with interrupted aortic arch and ventricular septal defect: a multiinstitutional study. J Thorac Cardiovasc Surg 1994;107:1099-113.[Abstract/Free Full Text]
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Norwood WI, Ling P, Castaneda AR, Hougen TJ. Reparative operations for interrupted aortic arch with ventricular septal defect. J Thorac Cardiovasc Surg 1983;86:832-7.[Abstract]
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Scott WA, Rocchini AP, Bove EL, Behrendt DM, Beekman RH, Macdonald D, et al. Repair of interrupted aortic arch in infancy. J Thorac Cardiovasc Surg 1988;96:564-8.[Abstract]
