Muscular Ventricular Septa1 Defect Repair Made Easy Benjamin L. Aaron, M.D., and Richard R. Lower, M.D. ABSTRACT Correction of the unique problem of congenital muscular ventricular septal defects is facilitated by approaching through an incision in the apex of the left ventricle parallel to the septum. This incision seems to be well tolerated by the heart, as borne out by our experience and that of others.
T
he muscular variety of congenital ventricular septal defect (VSD) comprises from 2 to 18% of the total number of patients with the defect and frequently is multiple and difficult to diagnose by usual angiographic methods [ 1, 31. The unsuspecting surgeon often discovers such defects when exploring through a standard high right ventriculotomy and is confronted with the dilemma of trying to ascertain, among the trabecular bands, the exact number and placement of the defects and how to close them adequately from a poor vantage point. We were confronted with this problem recently, and our solution was relatively simple and safe in light of recent advances in dealing with the muscular septum. A 14-month-oldwhite girl with a loud systolic murmur was found on cardiac catheterization to have a ventricular septal defect with a 5 : 1 left-to-right shunt. The main pulmonary artery pressure was 80/40 mm Hg and the right ventricular pressure was 80/0 mm Hg with normal pulmonary vascular resistance. Because of poor growth and development and the high right-sided pressures, she was referred for operative correction. Physical examination revealed a weight of 6.6 kg and normal findings save for the heart. There was a grade 3/6 pansystolic murmur at the fourth left intercostal space with a right ventricular heave and a grade 2/6 apical middiastolic murmur. The second heart sound was widely split and P2 was accentuated. Laboratory results were within normal limits. The electrocardiogram disclosed right ventricular hypertrophy with a frontal plane axis of + 100 degrees. The chest roentgenogram showed cardiomegaly with increased pulmonary vascularity and left atrial enlargement. Two days following admission she underwent an open-heart operation to close the VSD. Through a transverse right ventriculotomy over the pulmonary outflow tract, no VSD could be found in the usual infracristal position nor in the membranous portion. Further exploration disclosed two defects low in the muscular septum, quite remote from the ventriculotomy and obscured by the trabeculaFrom the Division of Thoracic and Cardiac Surgery, Medical College of Virginia Hospital, Richmond, Va. Accepted for publication Sept. 27, 1974. Address reprint requests to Dr. Lower, Box 97, MCV Station, 1200 E. Broad St., Richmond, Va. 23298. 568
THE ANNALS OF THORACIC SURGERY
HOW TO DO IT: Muscular
VSD Repair
tions of the right ventricular apex. Because of the poor exposure and possibility of other undisclosed defects, a small incision was made in the apex of the left ventricle parallel to the septum (Figure), which afforded an excellent view of the smooth left side of the septum and confirmed the presence of only two defects entering the left ventricle through a nearby common channel. These were closed separately without difficulty using mattress sutures buttressed with Teflon pledgets. The separate ventriculotomies were closed in routine fashion with running silk. Her postoperative course was relatively smooth and uncomplicated. The SGOT and LDH levels were somewhat elevated, but clinically she had no evidence of left ventricular malfunction and the electrocardiogram showed essentially no change from the preoperative tracing. She was discharged on the ninth postoperative day.
Comment Muscular defects of the ventricular septum may be single or multiple, with two or more holes giving the septum a “Swiss cheese” appearance. Though often isolated lesions, they may be associated with ventricular septa1defects of the more common variety and rarely may even be the sole defect associated with a classic tetralogy of Fallot [ 6 ] .The particular quality of these defects which makes their repair difficult from the right side is their involvement in the trabeculae carneae, those interlaced muscular bands that encompass numerous rills and valleys, any one of which may penetrate through to the left ventricle. Even more enigmatic is the sinusoidal and branching nature of these defects, often giving fewer holes on the left than on the right side of the septum 151. Partial or complete closure of muscular defects is most often accomplished through the usual ventriculotomy centered over the pulmonary outflow tract, as
An incision is made in an auascular area of the left ventricular apex to expose the defects in the muscular septum. VOL. 19, NO. 5, MAY, 1975
569
AARON AND LOWER this is where the operation was begun and the surgeon is reluctant to injure the heart further by other incisions or manipulations. Shumacker [9],recognizing the inherent difficulty with this poor exposure, advocated placing the right ventriculotomy directly over the defect(s) with care not to injure major coronary vessels. This variation improves the view, but still the maze of trabeculae carneae must be confronted. A unique method for obliterating multiple defects, developed by Kirklin’sgroup [8] at the Mayo Clinic and utilized by Breckenridge and colleagues El] in 17 patients, encompasses the defects with parallel mattress sutures placed from a strip of Dacron or Teflon fabric on the anterior surface of the septal walljunction to a second strip of fabric at the upper end of the muscular septum. T h e imprecision of this technique, however, is attested to in Breckenridge’s report, in which 3 of the 17 patients so treated required reoperation for residual defects and an unspecified number have residual murmurs and some evidence of shunting. Ventricular septal defects of the usual variety have been approached and repaired through the right ventricle, right atrium, or aorta, but left ventriculotomy has been avoided because of fear of injuring the systemic pump [4].In the past five years or so, however, use of a fish-mouth type of incision in the left ventricle to approach defects in the muscular septum resulting from myocardial infarction has been demonstrated to be technically advantageous and well tolerated by the heart [7]. This use of left ventriculotomy has generally been regarded by surgeons as a special application, because this part of the ventricle is often infarcted and nonfunctional as well so that surgical injury is no additional insult. Clark and co-workers [2]have also recently shown the usefulness and feasibility of this approach in repairing a traumatic VSD. We found the view and exposure of the smooth left side of the septum to be ideal through this incision. Both holes from the right side entered the left ventricle through a common antrum and were easily closed with mattress sutures. Placing of a patch would have been equally easy to do. Injury to the left ventricle wawas well tolerated and not perceptible clinically or in postoperative ECGs.
References 1.
Breckenridge, 1. M., Stark, J., Waterston, D. J., and Bonham-Carter, R. E. Multiple ventricular septal defects. Ann Thorac Surg 13:128, 1972. 2. Clark, T. A., Corcoran, F. H., Baker, W. P., and Mills, M. Early repair of traumatic ventricular septal defect. J Thorac Cardiovasc Surg 67: 12 1, 1974. 3. Cooley, D. A., and Hallman, G. L. Surgical Treatment of Congenital Heart Disease. Philadelphia: Lea & Febiger, 1966. P 118. 4. Cooley, D. A., Hallman, G. L., Wukasch, D. C., and Sandiford, F. M. Traumatic repair of ventricular septal defect. Ann Thorac Surg 16:99, 1973. 5. Edwards, J. S. Malformations of Ventricular Septa1 Complex. In S. E. Gould (Ed), Pathology of the Heart and Blood Vessels. Springfield, Ill.: Thomas, 1968. P 286. 6. Edwards,J. E., Carey, L. S., Neufeld, H. N., and Lester, R. G. Congenital Heart Disease, Vol. I. Philadelphia: Saunders, 1965. 7. Giuliani, E. R., Danielson, G. K., Pluth, J. R., Odynies, N. A., and Wallace, R. B. Post-infarction ventricular septal rupture. Circulation 39:455, 1974. 8. Kirklin, J. W., Karp, R. B., and Bargeron, L. N. In J. H. Gibbon, D. L. Sabiston, and F. C. Spencer (Eds),Surgery of the Chest (2d ed). Philadelphia: Saunders, 1969. P 716. 9. Shumacker, H. B., Jr. The repair of defects of the muscular portion of the ventricular septum. Surg Gynecol Obstet 136:103, 1973. 5 70
THE ANNALS OF THORACIC SURGERY
T
he muscular variety of congenital ventricular septal defect (VSD) comprises from 2 to 18% of the total number of patients with the defect and frequently is multiple and difficult to diagnose by usual angiographic methods [ 1, 31. The unsuspecting surgeon often discovers such defects when exploring through a standard high right ventriculotomy and is confronted with the dilemma of trying to ascertain, among the trabecular bands, the exact number and placement of the defects and how to close them adequately from a poor vantage point. We were confronted with this problem recently, and our solution was relatively simple and safe in light of recent advances in dealing with the muscular septum. A 14-month-oldwhite girl with a loud systolic murmur was found on cardiac catheterization to have a ventricular septal defect with a 5 : 1 left-to-right shunt. The main pulmonary artery pressure was 80/40 mm Hg and the right ventricular pressure was 80/0 mm Hg with normal pulmonary vascular resistance. Because of poor growth and development and the high right-sided pressures, she was referred for operative correction. Physical examination revealed a weight of 6.6 kg and normal findings save for the heart. There was a grade 3/6 pansystolic murmur at the fourth left intercostal space with a right ventricular heave and a grade 2/6 apical middiastolic murmur. The second heart sound was widely split and P2 was accentuated. Laboratory results were within normal limits. The electrocardiogram disclosed right ventricular hypertrophy with a frontal plane axis of + 100 degrees. The chest roentgenogram showed cardiomegaly with increased pulmonary vascularity and left atrial enlargement. Two days following admission she underwent an open-heart operation to close the VSD. Through a transverse right ventriculotomy over the pulmonary outflow tract, no VSD could be found in the usual infracristal position nor in the membranous portion. Further exploration disclosed two defects low in the muscular septum, quite remote from the ventriculotomy and obscured by the trabeculaFrom the Division of Thoracic and Cardiac Surgery, Medical College of Virginia Hospital, Richmond, Va. Accepted for publication Sept. 27, 1974. Address reprint requests to Dr. Lower, Box 97, MCV Station, 1200 E. Broad St., Richmond, Va. 23298. 568
THE ANNALS OF THORACIC SURGERY
HOW TO DO IT: Muscular
VSD Repair
tions of the right ventricular apex. Because of the poor exposure and possibility of other undisclosed defects, a small incision was made in the apex of the left ventricle parallel to the septum (Figure), which afforded an excellent view of the smooth left side of the septum and confirmed the presence of only two defects entering the left ventricle through a nearby common channel. These were closed separately without difficulty using mattress sutures buttressed with Teflon pledgets. The separate ventriculotomies were closed in routine fashion with running silk. Her postoperative course was relatively smooth and uncomplicated. The SGOT and LDH levels were somewhat elevated, but clinically she had no evidence of left ventricular malfunction and the electrocardiogram showed essentially no change from the preoperative tracing. She was discharged on the ninth postoperative day.
Comment Muscular defects of the ventricular septum may be single or multiple, with two or more holes giving the septum a “Swiss cheese” appearance. Though often isolated lesions, they may be associated with ventricular septa1defects of the more common variety and rarely may even be the sole defect associated with a classic tetralogy of Fallot [ 6 ] .The particular quality of these defects which makes their repair difficult from the right side is their involvement in the trabeculae carneae, those interlaced muscular bands that encompass numerous rills and valleys, any one of which may penetrate through to the left ventricle. Even more enigmatic is the sinusoidal and branching nature of these defects, often giving fewer holes on the left than on the right side of the septum 151. Partial or complete closure of muscular defects is most often accomplished through the usual ventriculotomy centered over the pulmonary outflow tract, as
An incision is made in an auascular area of the left ventricular apex to expose the defects in the muscular septum. VOL. 19, NO. 5, MAY, 1975
569
AARON AND LOWER this is where the operation was begun and the surgeon is reluctant to injure the heart further by other incisions or manipulations. Shumacker [9],recognizing the inherent difficulty with this poor exposure, advocated placing the right ventriculotomy directly over the defect(s) with care not to injure major coronary vessels. This variation improves the view, but still the maze of trabeculae carneae must be confronted. A unique method for obliterating multiple defects, developed by Kirklin’sgroup [8] at the Mayo Clinic and utilized by Breckenridge and colleagues El] in 17 patients, encompasses the defects with parallel mattress sutures placed from a strip of Dacron or Teflon fabric on the anterior surface of the septal walljunction to a second strip of fabric at the upper end of the muscular septum. T h e imprecision of this technique, however, is attested to in Breckenridge’s report, in which 3 of the 17 patients so treated required reoperation for residual defects and an unspecified number have residual murmurs and some evidence of shunting. Ventricular septal defects of the usual variety have been approached and repaired through the right ventricle, right atrium, or aorta, but left ventriculotomy has been avoided because of fear of injuring the systemic pump [4].In the past five years or so, however, use of a fish-mouth type of incision in the left ventricle to approach defects in the muscular septum resulting from myocardial infarction has been demonstrated to be technically advantageous and well tolerated by the heart [7]. This use of left ventriculotomy has generally been regarded by surgeons as a special application, because this part of the ventricle is often infarcted and nonfunctional as well so that surgical injury is no additional insult. Clark and co-workers [2]have also recently shown the usefulness and feasibility of this approach in repairing a traumatic VSD. We found the view and exposure of the smooth left side of the septum to be ideal through this incision. Both holes from the right side entered the left ventricle through a common antrum and were easily closed with mattress sutures. Placing of a patch would have been equally easy to do. Injury to the left ventricle wawas well tolerated and not perceptible clinically or in postoperative ECGs.
References 1.
Breckenridge, 1. M., Stark, J., Waterston, D. J., and Bonham-Carter, R. E. Multiple ventricular septal defects. Ann Thorac Surg 13:128, 1972. 2. Clark, T. A., Corcoran, F. H., Baker, W. P., and Mills, M. Early repair of traumatic ventricular septal defect. J Thorac Cardiovasc Surg 67: 12 1, 1974. 3. Cooley, D. A., and Hallman, G. L. Surgical Treatment of Congenital Heart Disease. Philadelphia: Lea & Febiger, 1966. P 118. 4. Cooley, D. A., Hallman, G. L., Wukasch, D. C., and Sandiford, F. M. Traumatic repair of ventricular septal defect. Ann Thorac Surg 16:99, 1973. 5. Edwards, J. S. Malformations of Ventricular Septa1 Complex. In S. E. Gould (Ed), Pathology of the Heart and Blood Vessels. Springfield, Ill.: Thomas, 1968. P 286. 6. Edwards,J. E., Carey, L. S., Neufeld, H. N., and Lester, R. G. Congenital Heart Disease, Vol. I. Philadelphia: Saunders, 1965. 7. Giuliani, E. R., Danielson, G. K., Pluth, J. R., Odynies, N. A., and Wallace, R. B. Post-infarction ventricular septal rupture. Circulation 39:455, 1974. 8. Kirklin, J. W., Karp, R. B., and Bargeron, L. N. In J. H. Gibbon, D. L. Sabiston, and F. C. Spencer (Eds),Surgery of the Chest (2d ed). Philadelphia: Saunders, 1969. P 716. 9. Shumacker, H. B., Jr. The repair of defects of the muscular portion of the ventricular septum. Surg Gynecol Obstet 136:103, 1973. 5 70
THE ANNALS OF THORACIC SURGERY
