Rosemary Frame

Technique for harvesting the radial artery as a coronary artery bypass graft.

The radial artery was proposed and then abandoned as a coronary artery bypass graft in the 1970s. Development of new pharmacologic antispasmodic agents and minimally traumatic harvesting techniques has led to a revival of the use of the radial artery in coronary artery bypass procedures. Unlike the saphenous vein in the lower extremities, the radial artery in the volar forearm is not a subcutaneous structure. Safe harvest of the artery requires an understanding of volar forearm anatomy. Based on review of anatomy, cadaver dissection, and clinical experience with 40 patients, we have developed a technique for radial artery harvest. The volar forearm is divided into three zones: the proximal zone, the middle zone, and the distal zone. In each zone, important anatomic landmarks are identified. Our harvesting technique has resulted in minimal postoperative morbidity and no postoperative ischemic complications. Although the pedicled internal thoracic artery graft remains the primary arterial conduit for myocardial revascularization, the radial artery is an excellent additional bypass conduit.

Automatic implantable cardioverter-defibrillator: Patient survival, battery longevity and shock delivery analysis

The automatic implantable cardioverter-defibrillator (AICD) has been shown to reduce the mortality rate of patients with malignant ventricular tachyarrhythmias. This report describes experience with implantation of 36 automatic implantable cardioverter-defibrillators (AID-B and AID-BR models) in 22 persons over a 44 month patient follow-up period (mean 19.6 months). There were five deaths: two patients died suddenly 22 and 29 months, respectively, after their second implant, one died of congestive heart failure, one died of respiratory failure and one died of catheter sepsis. Although 11 (50%) of the 22 patients never received a countershock for a ventricular tachyarrhythmia and are still alive, the other 11 received one or more spontaneous countershocks. Nine patients (41%) experienced spurious shocks during the follow-up period. Assuming that the first shock for presumed ventricular tachyarrhythmia prevented death, the hypothetical cumulative survival of patients at 42 months would have been 34 +/- 14.1% in the absence of an automatic implantable cardioverter defibrillator rather than the actual survival rate of 59 +/- 16.8%. The cumulative device survival of the 36 AID-B units was 92 +/- 5.62% at 15 months but diminished to 37 +/- 14.4% by 20 months. No unit lasted longer than 22 months. There were 12 battery depletions. The number of shocks emitted did not influence unit longevity. The manufacturers elective replacement indicator is of uncertain validity. Six units remained active 7 to 17 months after surpassing their replacement indicator. The automatic implantable cardioverter-defibrillator prolongs the life of many patients with otherwise intractable arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Routine use of unilateral and bilateral radial arteries for coronary artery bypass graft surgery.

OBJECTIVES This study sought to evaluate the routine use of radial artery (RA) grafts in patients undergoing coronary artery revascularization. BACKGROUND Previous long-term studies have documented poor patency of saphenous vein grafts compared with internal thoracic artery (ITA) grafts. METHODS We performed a prospective review of 175 of 249 consecutive patients. RESULTS Fifty-four patients had bilateral RAs harvested. Mean number (+/- SD) of grafts/patient was 3.27 +/- 0.93, with 2.76 +/- 0.97 arterial grafts; a mean of 1.53 +/- 0.68 grafts were performed with the RA. The operative mortality rate was 1.6%. No deaths were related to RA grafts, and there were no RA harvest site hematomas or infections. Transient dysesthesia 1 day to 4 weeks in duration occurred in the distribution of the lateral antebrachial cutaneous nerve in six extremities (2.6%). Elective cardiac catheterization in 60 patients at 12 weeks postoperatively demonstrated a 95.7% patency rate. CONCLUSIONS Because of potential benefit of long-term patency associated with arterial grafts, minimal morbidity and mortality associated with use of the RA and excellent short-term patency rates, we cautiously recommend use of one or both RAs as additional conduits to be used concomitantly with the ITA for arterial revascularization of the coronary arteries.

Surgical Removal of Infected Transvenous Pacemaker Leads

Infection, though uncommon, can be the most lethal of all potential complications following transvenous pacemaker implantation. Eradication of infection associated with pacemakers requires complete removal of all hardware, including inactive leads. Since 1972, 5,089 patients have had 8,508 pacemaker generators implanted at Montefiore Medical Center. There were 91 infections (1.06%); four of our patients required surgical removal. Nine additional patients were referred for surgical removal of infected transvenous pacemaker leads from other institutions. Surgical methods for removal included use of cardiopulmonary bypass or inflow occlusion. Surgery may be safely used in unstable or elderly patients and should not be reserved as a last resort. This article reviews our surgical experience removing infected pacemaker leads at Montefiore Medical Center.

Pathology of the Radial and Internal Thoracic Arteries Used as Coronary Artery Bypass Grafts

BACKGROUND This investigation compared the incidence and the degree of atherosclerosis present in radial artery (RA) and internal thoracic artery segments remaining after coronary artery bypass grafting. METHODS One hundred seventy specimens from 102 patients were histologically analyzed, including 106 RA specimens. RESULTS The mean degree of pathology for the RA was 0.89 on a 0 (none) to 4 (lumen completely obliterated) scale; the mean grade of pathology for the internal thoracic artery was 0.30 (p < 0.001). Presence of diabetes, aortofemoral disease, femoral-popliteal disease, age, and male gender correlated with an increase in RA pathology. Flow in the in situ RA did not correlate with the degree of pathology. CONCLUSIONS Study of the excess RA and internal thoracic artery segments remaining after coronary artery bypass grafting demonstrated that the RA had a higher degree of atherosclerosis than the internal thoracic artery at the time of harvest. Overall severity of disease in the RA was low. The long-term performance of RA grafts will determine whether this level of atherosclerotic disease has any clinical significance.

Long-term stability of defibrillation thresholds with intrapericardial defibrillator patches.

From March 1982 to May 1, 1992, 105 consecutive patients underwent initial implant of cardioverter defibrillators (ICD) at our institution. Twenty‐nine patients (23 male and 6 female, average ejection fraction 32.24%) with ICD systems implanted via thoracotomy and either intra‐ or extrapericardial patches, had one or more revisions including 56 generator changes or staged implant procedures, three patch revisions, one patch lead fracture without revision, and one sensing lead revision. The time between pulse generator revisions averaged 19.5 months. Initial defibrillation threshold mean was 12.8 joules (n = 25); at first revision, 14.46 joules (n = 29), (P = NS); by fifth revision, 15.0 joules (n = 2), (P = NS). One patch was noted to be crinkled at 70 months; one patch had migrated by 39 months, and two patch leads had fractured at the costal margin by 69 and 90 months. One patient with marginal defibrillation thresholds had an additional patch placed at revision to an upgraded ICD unit. Once acceptable defibrillation threshold (DFT) is obtained, the long‐term intrapericardial DFT remains stable unless a specific problem occurs. As a small, nonstatistically significant increase in DFT may occur, caution must be exercised in patients with marginal DFTs.

Survival of Patients with the Automatic Implantable Cardioverter Defibrillator

Between May 1982 and May 1988, 37 patients (28 males and 9 females, mean age 57.6, range 16–76 years) of approximately 600 evaluated for sustained ventricular tachycardia and/or fibrillation (VT/VF) were treated with an automatic implantable cardioverter defibrillator (AICD). Twenty‐eight of the patients had coronary artery disease, 7 had nonischemic cardiomyopathy, 1 had amyloid hear disease, and 1 had rheumatic heart disease. The mean ejection fraction was 32.2 ± 12.9% (range, 9–64%). Eleven patients have died at a mean of 16.7 months after implantation. The cumulative survival rate was 81% at 1 year, 77% at 2 years. 68% at 3 years, and 53% at 4, 5, and 6 years. Considering only sudden deaths, the survival was 97% at 1 and 2 years, 90% at 3 years, and 80% at 4, 5, and 6 years. Twenty‐one of the 37 patients received spontaneous shocks. If the first shock marks the time to death in the absence of an AICD, the cumulative survival rate would have been 56% at 1 year, 42% at 2 years, 29% at 3 years, and 14% at 4, 5, and 6 years. The maximum amount of time to a first appropriate shock was 39.7 months. Thirty‐nine devices have been explanted; 28 for battery depletion; 5 for infections; 3 for improper sensing; 2 for electronic failure; and 1 at the time of cardiac transplantation. The average time to failure of the 28 units removed for battery depletion was 19.8 ±6.9 months. We conclude that in this group of patients, short‐term survival is increased by AICD implantation, hut long‐term survival remains poor. Incidence of sudden death is reduced to 3% at 1 and 2 years, 10% at 3 years, and 20% after 4 years. Other patient selection criteria may be useful in selecting those patients whose survival will be improved by the AICD.

Initial Experience with Transvenous Implantable Cardioverter Defibrillator Lead Systems: Operative Morbidity and Mortality

Introduction of non‐thoracotomy lead systems™ (Medtronic, Inc.) for the implantable cardioverter defibrillator (ICD) has expanded the indications for use of this mode of therapy. Patients previously considered “too ill” to undergo a thoracotomy as well as patients who are at a high risk for developing sudden death but without previous cardiac arrest, are now considered candidates. The initial experience with the non‐thoracotomy lead system at our institution was analyzed for morbidity and mortality. Thirty‐four patients underwent attempted intravascular lead implantation, with 30 having initial successful implantation (88.2%). There were 23 males; average ejection fraction (EF) was 38.6%. Three patients developed pulmonary edema and low output immediately after the procedure. Three patients developed electromechanical dissociation during defibrillation threshold testing. A prolonged testing time for the non‐thoracotomy lead system was noted when compared to the thoracotomy system (57.39 vs 32.30 min; P < 0.0000). There were more intraoperative morbidities with the non‐thoracotomy leads than with the thoracotomy system. There were no perioperative deaths. The potential consequences of prolonged anesthesia time and extensive defibrillation threshold testing should be considered when choosing the route of ICD implant, the type of anesthesia, and the intraoperative testing protocol for each patient.

Comparison of defibrillator therapy and other therapeutic modalities for sustained ventricular tachycardia or ventricular fibrillation associated with coronary artery disease

Outcomes of 282 patients referred to the arrhythmia service at Montefiore Medical Center for sustained ventricular tachycardia (n = 214) or ventricular fibrillation (n = 68) associated with coronary artery disease were analyzed retrospectively. All patients underwent serial drug trials by electrophysiologic testing and Holter monitoring. Sixty-eight patients who did not respond to drug therapy were treated with implantable cardioverter-defibrillators (ICD group), and 214 patients were treated with other methods guided by electrophysiologic testing and Holter monitoring (non-ICD group). The non-ICD group included 49 patients who responded to drug therapy as judged by electrophysiologic testing, as well as patients who did not respond and were not treated with defibrillator therapy for various reasons. Ten patients died in the hospital (2 patients in the ICD group, 8 in the non-ICD group). Actuarial survival rates free of total cardiac death at 1, 2, and 3 years were, respectively, 94%, 87%, and 85% in the ICD group, and 82%, 78%, and 73% in the non-ICD group (p = NS). Survival rates free of total death at 1, 2, and 3 years were 90%, 82%, and 76% in the ICD group, and 82%, 76%, and 70% in the non-ICD group, respectively (p = NS). Survival rates free of total cardiac and total deaths of 49 patients treated with an effective regimen determined by electrophysiologic testing were not significantly different from those of the ICD group. This retrospective study suggests that outcomes of patients treated with ICDs may not be dramatically different from those of patients treated with other methods guided primarily by electrophysiologic testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Routine Myocardial Revascularization with the Radial Artery: A Multicenter Experience

Abstract Background: Current literature documents use of the radial artery (RA) for myocardial revascularization only as an alternative conduit in cases where the saphenous veins have been previously harvested or are unsuitable for use. Large‐scale routine clinical use of the RA as the conduit of choice has not been reported. Methods: This prospective study evaluated the harvest of the RA from 933 patients and the subsequent use of the conduit as a preferred coronary artery bypass graft second only to the left internal thoracic artery in 930 of these patients. Results: Unilateral RA harvest was performed in 786 patients and 147 patients had bilateral RA harvest. A total of 1080 RAs were harvested; 214 (19.8%) originated from the dominant forearm. There was a mean of 3.30 ± 0.93 grafts per patient of which 2.43 ± 0.83 were arterial grafts. The mean number of RA grafts was 1.43 ± 0.53. Operative mortality was 2.3% with none due to the RA graft(s). There was no ischemia nor motor dysfunction in the operated hands. Thirty‐two (3.4%) patients experienced transient thenar dysesthesia that resolved in 1 day to 6 weeks. Conclusions: Our results demonstrate that routine total or near total arterial myocardial revascularization may be achieved safely and effectively with the use of one or both RAs in conjunction with the internal thoracic artery.