Gerald M. Lemole

A New Retractor to Aid in Coronary Artery Surgery

During coronary artery bypass grafting, exposing the arteries can be difficult, especially on the posterior and lateral aspects of the left ventricle. A silicone-covered flexible retractor has been modified to facilitate this procedure. Its central opening and easy malleability aid in myocardial retraction and coronary artery bypass grafting.

Adjunct Endarterectomy of the Left Anterior Descending Coronary Artery

During a three-year period, complete revascularization of diffusely diseased left anterior descending (LAD) coronary arteries was accomplished by extensive endarterectomy in conjunction with bypass grafting in 37 patients in whom conventional bypass was not feasible. This group constituted 7.0% of all patients undergoing nonemergency coronary revascularization during this period. The left internal mammary artery was used to bypass the endarterectomized LAD artery in 22 patients. There was 1 (2.7%) operative death and 1 perioperative myocardial infarction. At follow-up, which was 100% with a mean of 41.4 months, all endarterectomy patients were in New York Heart Association Functional Class I or II. Twenty-four endarterectomy patients underwent first-pass radionuclide angiographic stress testing 20 months after operation. Twenty patients (83%) had excellent postoperative exercise tolerance, achieving 5 to 7 mets on treadmill testing. Left ventricular functional reserve was preserved, as evidenced by an increase of global ejection fraction from 48 +/- 15% at rest to 59 +/- 18% (p less than 0.005) with exercise. A similar increase was measured in the proximal and distal anterior wall segmental ejection fractions. No difference in response to exercise was found between the internal mammary artery and the vein graft groups. Thus, complete revascularization of the diffusely diseased LAD artery can be accomplished by adjunct endarterectomy without added morbidity or mortality and with excellent functional results.

The Role of Lymphstasis in Atherogenesis

The cardiac lymphatics are responsible for the transport of all the lipoproteins and cholesterol from the extravascular myocardial tissue, although little is known about the filtration and lymphatic clearance of the coronary artery wall. It is postulated that a critical factor in the genesis of arteriosclerosis is lymphstasis, which adequately explains the positive correlation with the known risk factors for coronary artery disease and the negative correlation with high-density lipoproteins. Further research is necessary in this little-known area to better understand the etiology of atherosclerosis.

Rigid intraluminal prosthesis for replacement of thoracic and abdominal aorta.

During the past seven years, 80 patients have undergone aortic substitution using a rigid intraluminal prosthesis. There were 9 early deaths. The procedures involved 32 dissecting aneurysms (18 ascending and 14 descending), 16 atherosclerotic aneurysms of the ascending aorta and 13 atherosclerotic aneurysms of the descending aorta, 3 thoracoabdominal aneurysms, 2 arch aneurysms, and 14 abdominal aortic aneurysms. There was one early dislodgment of the rings necessitating reoperation, but no other early complications related to the procedure. In the follow-up period (mean, 25 months) there were 6 late deaths. One occurred 6 months after operation in a patient with empyema. There were no late complications of thrombosis, erosion, pseudoaneurysm formation, or hemorrhage. The follow-up data are extremely encouraging. We now are using this device whenever possible in all substitutions of the aorta, although in approximately 40% of patients, it is necessary to remove one of the spools and suture either the proximal or distal end of the graft owing to the close proximity of the aneurysm to the coronary ostia or the origin of the subclavian artery. Important techniques of insertion and postoperative angiograms are presented.

Rigid intraluminal prosthesis for replacement of thoracic and abdominal aorta

From December 1976 to April 1983, 55 patients underwent operations in which intraluminal ring grafts were used for replacement of thoracic and abdominal aortic aneurysms. Twenty-eight patients had dissections, and 11 had ascending aneurysms. There were 10 descending aneurysms; three of these were traumatic. There were two arch aneurysms, three abdominal aneurysms, and one thoracoabdominal aneurysm. The follow-up period was 78 months with a mean follow-up period of 24 months. There were six postoperative deaths and six late deaths. No evidence of complications of thrombosis, migration, erosion, or pseudoaneurysm resulting from the ring within the 78-month follow-up period was seen, and we conclude that this is a safe, reliable, quick method for replacement of the aorta in certain well-defined situations.

Transvenous Pacemaker Insertion with a Zero Dislodgement Rate

A non‐retractable transvenous screw‐in lead which gives both stability of placement and low acute and chronic stimulation thresholds was used in 64 patients during the period April, 1979 to June, 1981. The average threshold at implant was 0.7 volts; the current threshold average was .86 milliamps with the pulse width at the standard setting for the pacemaker employed. Chronic thresholds were usually below the lower programmable limit of the pacer as tested at 3 months. In one patient, the fact that the screw was fixed in the exposed position caused trouble. The lead became knotted in the superior vena cava and was removed by thoracotomy. Although this experience with the Osypka lead was not entirely satisfactory, newer developments with retractable leads may make the principle more acceptable.

Rupture of Pulmonary Artery by Swan-Ganz Catheter: A Cause of Postoperative Bleeding after Open-Heart Operation

Abstract Fifteen patients with rupture of the pulmonary artery by a Swan-Ganz catheter have been reported to date; 6 of them survived. The patient considered here underwent open-heart operation and then had severe bleeding secondary to distal pulmonary arterial rupture by a flow-directed balloon-tipped Swan-Ganz catheter. Knowledge of this specific complication may avoid needless delay in the diagnosis and control of postoperative bleeding.

Redundant Pacing: Case Report and Review

A 17‐year‐old boy with severe sick sinus bradycardia had a doubly redundant pacemaker inserted. With two separate ventricular leads inserted by the epicardial route, the pacemaker is able to compensate for a lead that has developed high threshold by activation of an alternate lead. The two pacing channels of the pulse generator can be programmed independently of one another. In addition, there is a back‐up pacing circuit separate from the two primary channels. The pacer can be used with both channels active for continuous automatic redundancy for safety, or with one channel active and the other in reserve.

Charge Levels in Programmable Pacemakers

The method of calculation of charge in one series of programmable pacemakers is described. Accurate charge tables are constructed and examples of their use are given. With the tables the margin between the threshold and the pacemaker setting can be more precisely determined and consequently, at least in some cases, it can be reduced for greater pacemaker longevity.

Improved Techniques in Using the Swan-Ganz Catheter

Abstract Techniques of fixation, isolation, changes of position, and passing to the distal pulmonary artery of the Swan-Ganz catheter are described. They have been used in 210 patients requiring long-term hemodynamic monitoring at the Deborah Heart and Lung Center.