688 The Annals of Thoracic Surgery Vol 35 No 6 June 1983
Coronary Vein Graft Marking To the Editor:
Cardioplegia with Transvenous Pacing To the Editor:
The report by Milo, Massini, and Goor entitled “Coronary Vein Graft Marking: Method to Prevent Graft Twisting and Length Misjudgment” (Ann Thorac Surg 33:200, 1982) describes a method of utilizing a black silk suture as a reference marker to prevent graft twisting. This is indeed an excellent method, and was used for decades by the late Robert R. Linton in thousands of operations using the saphenous vein in a peripheral position. A more rapid and less cumbersome adaptation of this method was, to my knowledge, first used by Eldred D. Mundth at the Massachusetts General Hospital. Rather than utilizing a silk suture, he used a skin marking pen to make a reference line after the vein had been excised, untwisted, and distended. I have used that method (the Linton method as modified by Mundth) in several thousands of saphenous vein segments and have found it less cumbersome than the method described by Milo and co-workers. For historical interest, Dr. Linton’s description of this original method can be found in his monumental Atlas of Vascular Surgery (Philadelphia: Saunders, 1973, p 420).
The patient who has a permanent transvenous pacemaker inserted for heart block or other rhythm disturbances and who is to undergo an open-heart operation poses a challenge if cardioplegic arrest is to be used. In ”Pacemaker Inhibition in Cardiac Surgery” (Ann Thorac Surg 33:294, 1982), Hakki and colleagues described an elegant method of pacemaker inhibition by placement of electrodes over the skin of the patient, thereby “overriding” it. We recommend an alternate technique, which we have used without serious problems in 10 consecutive patients. Standard cardiopulmonary bypass techniques are employed and the ascending aorta and right atrium are cannulated. While the heart is beating (by stimulation from the transvenous endocardial lead) and without any form of pacemaker inhibition or left ventricular venting, the aorta is cross-clamped and cardioplegic solution infused. Cardiac standstill occurs in 8 ? 2 seconds, which is similar to the time for hearts undergoing cardioplegic arrest without transvenous pacemakers. During the period of cardioplegic arrest, pacemaker spikes can be seen in the electrocardiographicmonitor without QRS complexes or visible myocardial activity. Following completion of all anastomoses (proximal and distal), the aorta is unclamped; heart action resumes by stimulation from the transvenous pacemaker as the cardioplegic solution is washed off. A temporary epicardial pacemaker wire is left in place for the early postoperative period. Permanent epicardial leads were not implanted in this series of patients, and there were two endocardial lead displacements requiring insertion of a new transvenous lead. Since displacement occurred only in two endocardial leads that had been implanted 2 years previously, perhaps it is wise to place permanent epicardial leads in those patients with recently inserted transvenous pacemakers. There were no other serious problems related to the technique in this series. From this limited experience, we believe that there is no need to inhibit the transvenous pacemaker either prior to or during cardioplegic arrest. Further, one should be aware of the possibility of left ventricular distention in nonvented hearts, as the heart goes into standstill if an artificial impulse is applied to the skin prior to aortic clamping and cardioplegic arrest.
Ronald M . Abel, M . D . Associate Director Department of Thoracic and Cardiovascular Surgery Newark Beth Israel Medical Center 201 Lyons Ave Newark, NJ 07112
Reply To the Editor: Dr. Linton, in his Atlas of Vascular Surgery (Philadelphia: Saunders, 1973, p 420), does indeed use a silk thread as a marker to prevent vein graft twisting, a fact of which we were unaware. However, the sequence of events in the procedure is different. He placed the silk marker after the side branches of the saphenous vein had been ligated and divided, and after the vein graft had been removed and distended. Placing the silk marker while the vein is still in situ in our opinion secures the future graft against possible twisting that might occur during its distention. It is, we believe, safer, surgically simpler, and faster to perform. Simcha Milo, M . D . Carlo Massini, M . D . D . A . Goor, M . D .
Tomas A . Salerno, M . D . Division of Cardiovascular and Thoracic Surgery McGill University Montreal, Que, Canada H3A I A l
Department of Thoracic and Cardiovascular Surgery The Chaim Sheba Medical Center Tel-Hashomer, Israel 52621
Edward 1. P . Charrette, M . D . Cardiovascular and Thoracic Surgery Queen’s University Kingston, Ont, Canada K7L 2V7