Marc T. Swartz

Clinical experience with 111 thoratec ventricular assist devices

BACKGROUND Ventricular assist devices (VADs) have gained wider acceptance due to refinements in patient selection and management and device availability. METHODS To evaluate early and late results, we reviewed our first 111 patients with the Thoratec VAD. RESULTS Forty-four patients were supported for myocardial recovery. The mean age in the recovery group was 51.9 years. There were 18 left VADs (LVADs), 17 biventricular VADs (BVADs), and nine right VADs (RVADs). Complications included bleeding in 20 patients (45%) and device-related infection in 1 patient (2%). Nineteen were weaned from the VAD, with 12 survivors. Sixty-seven patients were supported as a bridge to cardiac transplantation. The mean age was 41.5 years. There were 39 LVADs and 28 BVADs. Complications included bleeding in 21 patients (31%) and device-related infection in 12 (18%). Three patients were weaned and 39 patients were transplanted from the assist device, for a total of 42 bridge survivors. Device-related thromboembolism occurred in 9 patients (8.1%), 7 of whom were bridge to transplantation. The duration of VAD support ranged from 0.1 to 27 days (mean 4.5 days) in the recovery group and 0.2 to 184 days (mean 40.7 days) in the bridge to transplantation group. The 10-year actuarial survival was 16% for the recovery group, 22%, for the bridge group, and 33% for transplanted patients. CONCLUSIONS Despite advances, VAD support remains associated with significant morbidity and operative mortality.

Late Patency of the Internal Mammary Artery as a Coronary Bypass Conduit

From January, 1972, through August, 1977, 472 patients had internal mammary artery (IMA) coronary bypass, of which 100 were double-IMA bypasses. We selected those patients having a widely patent IMA one year postoperatively who then had a second catheterization 49 to 105 (mean, 64) months following operation. None of the 93 patients who met these criteria was specifically recalled for this study; they all had follow-up catheterizations for multiple other reasons. All of the 91 left IMA and 22 right IMA bypasses (total, 113) were patent at late catheterization, but 1 right IMA was diffusely narrowed. One left IMA had acute angulation with 50% stenosis proximal to the distal anastomosis, which was unchanged over the follow-up interval. There were 100 patent saphenous vein bypasses at one year and 87 at late catheterization. Late closure of coronary bypass grafts is secondary to progression of coronary disease, atherosclerosis of the bypass conduit, or intimal proliferation. Because we have not encountered the latter two causes of conduit closure, IMA grafts remain our graft of choice for nonemergent operations in patients under 60 years of age having revascularization of the left anterior descending coronary artery system.

CARDIAC ASSIST DEVICES

During the latter half of the twentieth century, physicians have had the capability to support the circulation with mechanical devices. This article gives an historical overview of those devices. Various devices and their complications are described and evaluated. Patient selection and clinical results also are discussed.

The Importance of Biventricular Failure in Patients with Postoperative Cardiogenic Shock

To evaluate the importance of severe biventricular failure in patients with postcardiotomy ventricular failure, we analyzed the data from 30 patients treated with ventricular assist devices (VADs) over a five-year period. All patients had profound postoperative ventricular failure refractory to drugs and an intraaortic balloon (IAB). Evaluation of preoperative ventricular function did not allow prediction of which patients would require VADs. However, the development of perioperative myocardial infarction was an important determinant of the need for postoperative support with a VAD. Twenty patients received only a left VAD (LVAD). Four of them had isolated left ventricular failure; 3 were weaned, and 2 survived. None of the 16 patients with biventricular failure who received only an LVAD were weaned. Ten other patients with biventricular failure received biventricular support, either with a right VAD and IAB, or with two VADs. Of these 10 patients, 5 were weaned and 3 survived. Considering all 26 patients with biventricular failure, those receiving biventricular mechanical support (10) had a better chance (p less than 0.025) of being weaned (5/10) and surviving (3/10) than those who received only an LVAD (0/16). We conclude that biventricular failure is common in patients with postcardiotomy ventricular failure and is often the result of perioperative infarction. While patients with isolated left ventricular failure did well with an LVAD only, those with biventricular failure required biventricular mechanical support for survival.

Major leg wound complications after saphenous vein harvest for coronary revascularization

BACKGROUND Major leg wound complications after coronary artery bypass graft procedures are infrequent and few are reported in the literature. We present our experience in treating 23 patients with major leg wound complications after coronary revascularization procedures. METHODS A retrospective review of 3,525 bypass procedures with saphenous vein grafts performed over a 10-year period was conducted. Ten potential risk factors for those who developed major leg wound complications were analyzed and compared with the entire cohort of patients undergoing similar bypass procedures during the same period. RESULTS Lower extremity wound complications occurred in 145 patients (4.1%), 23 of whom (0.65%) required additional surgical interventions (62 total). There were 32 wound debridements, 8 skin grafts, 11 vascular procedures, 5 amputations, 3 fasciotomies, 2 free tissue transfers, and 1 fasciocutaneous flap. Of ten variables evaluated by multivariate analysis, female gender, peripheral vascular disease, and postoperative intraaortic balloon pump use were identified as significant independent predictors of major leg wound complications (p < 0.0001). CONCLUSIONS The causes of major leg wound complications after saphenous vein harvest for coronary artery bypass graft procedures are multifactorial. To minimize these complications, we recommend vascular evaluations before saphenous vein harvest, attention to proper surgical technique, and careful harvest site selection.

Intraaortic Balloon Pumping in Cardiac Surgical Patients: A Nine-Year Experience

Abstract From March, 1973, to April, 1982, 378 of 5,546 patients (6.8%) undergoing cardiac operations had insertion of an intraaortic balloon pump (IABP). The 378 patients ranged in age from 19 to 84 years (mean, 58.2 years) and included 4.7% of patients undergoing coronary bypass grafting and 10.6% of patients undergoing valve replacement. An IABP was inserted preoperatively in 22 patients with unstable angina pectoris and in 33 patients with cardiogenic shock; intraoperatively in 252 patients who could not be weaned from cardiopulmonary bypass; and postoperatively in 71 patients who had hemodynamic deterioration. The IABP was inserted by femoral arteriotomy in 201 patients, by percutaneous femoral puncture in 161 patients, and by transthoracic aortotomy in 16 patients. All patients received daily infusions of low molecular weight dextran without heparin during the IABP period. Duration of IABP support ranged from 1 to 384 hours (mean, 37.3 hours). Out of 230 patients weaned from the IABP, 202 patients were discharged from the hospital for an overall survival rate of 53.4%. The overall incidence of complications was 11.6%. There were 8 IABP-related deaths (2.1%), which were due to ruptured aorta in 6 patients, aortic dissection in 1 patient, and helium embolus in 1. Survival was higher in patients with insertion by percutaneous femoral puncture (99/161; 61.5%) than in patients with insertion by femoral arteriotomy (99/201; 49.3%) ( p p p

Vascular complications from intraaortic balloons: Risk analysis

PURPOSE The purpose of this study was to assess the incidence of and predictors for vascular complications in patients who required perioperative intraaortic balloon pump (IABP) support. METHODS Data from 580 patients collected with a retrospective review were statistically analyzed with 25 perioperative parameters, and significant variables were evaluated with multivariate analysis. These data were also statistically compared with data from a 1983 study from our institution. RESULTS Vascular complications occurred in 72 patients (12.4%). The three aortic perforations were fatal. Ipsilateral leg ischemia occurred in 69 patients. Of these, ischemia was resolved in 82% of patients by IABP removal (21), thrombectomy (21), vascular repair (13), fasciotomy (2), or without intervention (2). Six patients died with the intraaortic balloon in place. Four patients required amputation for ischemia, but all survived. CONCLUSIONS Vascular complications were not predictive of operative death (p = 0.26). Risk analyses with 25 perioperative parameters revealed that history of peripheral vascular disease, female sex, history of smoking, and postoperative insertion were independent predictors of vascular complications. However, most risk for vascular complications cannot be explained by these factors because of a low R2 value. Compared with the results of our 1983 study, the incidence of IABP-related complications has not changed, but the severity of complications has decreased significantly, and IABP-induced death has decreased significantly.

Use of the Pierce-Donachy ventricular assist device in patients with cardiogenic shock after cardiac operations.

In spite of recent improvements in cardiac surgery, a small percentage of patients have severe postcardiotomy ventricular failure refractory to drugs and the intraaortic balloon. In our experience, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most effective devices for these patients. Since 1981, 30 patients aged 15 to 71 years (mean age, 52 years) with profound cardiogenic shock refractory to conventional therapy after cardiotomy were supported with the Pierce-Donachy ventricular assist device. Fourteen required left ventricular support, 7 needed right ventricular support with an intraaortic balloon, and 9 had biventricular assistance. Duration of support ranged from three hours to 22 days (mean length, 3.6 days). Seven of the first 11 patients seen died in the operating room of bleeding, biventricular failure, or both. However, 16 patients (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (37%) were discharged. Of the last 19 patients in the series, 47% survived. Factors affecting survival were myocardial infarction (75%) and renal failure (90%). Common complications were bleeding (73%) and biventricular failure (83%).

Circulatory support in infants and children

Although the last decade has brought dramatic improvement in patient selection and postoperative management of adults and children undergoing advanced mechanical circulatory support, technological advances have been largely limited to the adult population. Intraaortic balloon pumps are technically feasible, but their efficacy has been questioned and their use has been limited in children. Over the last decade, extracorporeal membrane oxygenation has become the most commonly used method of mechanical circulatory support in children who have severe cardiac failure after cardiac operations. Additionally, a small number of infants and children have been supported with extracorporeal membrane oxygenation as a bridge to cardiac transplantation or as temporary support during reversible myocardial failure due to lesions such as viral myocarditis. More recently, a small number of pediatric patients have been supported with centrifugal and pneumatic devices, particularly after cardiac operations. Surprisingly, many of these patients did well with left ventricular support only. The overall childrens survival rates in the myocardial recovery group are better than those in adults. However, current pediatric devices do not provide support for greater than a few weeks, making bridging to transplantation less feasible than in adults.

Mitral valve replacement: randomized trial of St. Jude and Medtronic Hall prostheses

To better define the merits of the bileaflet and tilting-disc valves, we prospectively randomized 102 patients (mean age, 57 years; range, 11 to 85 years) to receive either the St. Jude (n = 55) or the Medtronic-Hall (n = 47) mitral valve prosthesis between September 1986 and May 1991. The two groups were not different with respect to preoperative New York Heart Association class, incidence of mitral stenosis and insufficiency, angina score, extent of coronary artery disease, ventricular function, completeness of revascularization, or cross-clamp or bypass time. The hospital mortality (14.5% versus 10.6%, St. Jude versus Medtronic-Hall) and late mortality (7.3% versus 2.1%) were not significantly different. Follow-up was complete in 84 of 89 hospital survivors (94%) with a mean of 26 months (range, 1 to 60 months). The linearized rates of valve-related events and the 3-year actuarial survival demonstrated no significant differences between both cohorts. Comparison of the clinical outcome and echocardiographic parameters obtained at the time of follow-up demonstrated no significant differences between the two prostheses. These data indicate that the Medtronic-Hall and St. Jude mitral prostheses are similar with respect to their rates of valve-related complications and hemodynamic profiles. This study suggests that there is no difference between the St. Jude and Medtronic-Hall prostheses with regard to early clinical performance or hemodynamic results and therefore does not support the preferential selection of either prosthesis.