AustralAs J Cardiac Thorac Surg 1992; l(2): p.11

INVITED COMMENTARY

Overlay Patch Technique For Ventricular Septal Defect Repair

Donald Ross, FRACS

Royal North Shore Hospital, Sydney, New South Wales, Australia

There is no doubt that the prospect of an acute ventricular septal defect (VSD) fills most cardiac sur- geons with a feeling of dread and hopelessness. They know they will be faced with a long and difficult pro- cedure with a host of operative and post-operative complications and very little prospect of a satisfactory outcome.

When a surgeon publishes a series with results that are so much better than you ,have been able to achieve, it is natural to suspect some bias in case selection. A few years ago this is how I would have greeted the results reported by Tirone David. How- ever, in our series of 9 survivors from 10 consecutive acute VSDs’ , we have come close to the excellent results from the Toronto Hospital.

All of our cases were in cardiogenic shock which compares with the 11 in the author’s series. The ages were comparable as was the anterior-to-posterior ratio. Both series have important aspects in common. These include the use of a large endocardial patch to cover all the infarcted myocardium, the pre-operative insertion of a balloon pump and grafting of diseased arteries.

Tirone David uses tanned pericardium attached with a continuous prolene suture to normal endo- cardial tissue and then closes the free wall with standard, buttressed, everting mattress sutures. Our method attaches a fabric patch to normal muscle with interrupted buttressed mattress sutures and closes the free-wall incision with a large epicardial Teflon-felt patch, using the previously placed interrupted endo- cardial patch sutures.

There are two aspects of Dr David’s technique which I question. Firstly, I have always had difficulty satisfying myself that a continuous prolene suture, which tears out so easily even from normal muscle, is secure enough for the rigors of the left ventricle. The technical aspects of suturing the patch to the septum in this way are relatively straightforward, despite problems of tearing and loosening. However, I can- not understand how this suture is used to secure the patch to the free wall, upside down and inside out, through a friable oedematous infarct. I attempted the author’s method in my last VSD closure. The peri-

cardial patch was quite satisfactory and handled better than the fabric we described. The prolene suture was satisfactory for the deepest aspect of the patch, as this part of the suture line ran along the an- nulus of the mitral valve. Things became less secure as each side was sutured to the muscle along the superior and inferior aspects of the VSD, but when it came to the free wall, I found it neeessary to revert to the interrupted buttressed mattress sutures of our technique and the final repair was a hybrid of the two methods giving a satisfactory result. The other aspect of the author’s method I cannot countenance is the technique of closure of the free wall incision. In vir- tually all our cases, this has been through acutely haemorrhagic, full-thickness infarct. We developed an overlay patch technique because of poor results using the traditional method, which frequently result- ed in uncontrollable haemorrhage (Fig. 1).

Fig. 1. Repair of VSD using overlay patch technique.

Either Tirone was fortunate, having cases with infarction confined to the septum, or he has a superior method for suturing mushy muscle. For those of us less gifted technically, the operation is still possible to reproduce using interrupted sutures, the key to success being the complete coverage of the en- tire VSD and infarct with an endocardial patch which is generously sized and under no tension.

Reference 1. Alverez JM, Brady PW, Ross DE. Acute post-infarction ven-

tricular rupture repair. J Cardiac Surg. In press.