Stenting unprotected left main coronary artery stenosis in heart transplant patients--the good, bad, and the ugly.

The major cause of late death following orthotopic heart transplantation is coronary artery vasculopathy. Approximately 50% of heart transplant patients have coronary artery vasculopathy 5 years post-transplantation. With advances in interventional cardiology technology, heart transplant patients with selected lesions are now undergoing intravascular stenting with acute-gain and late-loss rates similar to stenting in non-transplanted patients. We describe 3 consecutive cases of stenting unprotected left main coronary artery disease in orthotropic heart transplant patients. With follow-up to 3 years and no evidence of restenosis, these results suggest that stenting unprotected left main coronary artery lesions in heart transplant patients can be performed with excellent immediate and long-term results.

Endovascular stenting of an unprotected left main coronary artery stenosis in a heart transplant patient.

Endoluminal revascularizaion of left main coronary artery vessels is considered to be relatively contraindicated because of a high procedural mortality and restenosis rate. This report describes the first successful case of endovascular stenting in an unprotected left main coronary artery stenosis in a heart transplant patient.

Effect of prior sternotomy on mortality and morbidity after heart transplantation. Cardiac Transplant Team.

A retrospective analysis to evaluate the impact of prior sternotomy on the outcome of cardiac transplantation was undertaken. Some 165 patients who received primary heart transplantation were classified into three groups. There were 102 patients in group 1 (no prior sternotomy), 47 in group 2 (one prior sternotomy), and 16 in group 3 (more than one prior sternotomy). The three groups were demographically similar. Coronary artery bypass was the indication for prior sternotomy in 77% of patients in group 2 and in 94% in group 3. Mortality within 30 days post-transplant was significantly different among the three groups (group 1, 7.8%; group 2, 8.5%; group 3, 31%; P = 0.0148). The 1-year actuarial survival was also significantly lower in group 3 (52%) compared with groups 1 (83%) and 2 (81%) (P = 0.0311). Multivariate analysis identified more than one prior sternotomy and pulmonary hypertension as risk factors for death within 30 days post-transplant. Patients who had prior sternotomy also had a higher incidence of coagulopathy (group 1, 17%; group 2, 49%; group 3, 38%; P = 0.0002), and re-exploration due to excessive bleeding (group 1, 5%; group 2, 11%; group 3, 25%; P = 0.0225). Requirement for blood products for transfusion was also higher in groups 2 and 3. There was no significant difference among the three groups in the incidence of early infections (50% versus 53% versus 44%), renal failure (6% versus 11% versus 19%), or allograft rejection in patients who survived the first 30 days (95% versus 86% versus 82%).(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of ventilation and perfusion with different modes of mechanical ventilation.

We compared pulmonary gas exchange during synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV), and airway pressure release ventilation (APRV). Nine subjects aged 56 to 75 yr were studied from 4 to 19 h after cardiac operations. When subjects were ready to be weaned from mechanical ventilation their ventilation-perfusion distribution was estimated using the multiple inert gas elimination technique during SIMV. The subjects then received PSV and APRV during alternating periods on a randomized basis, and the gas-exchange measurements were repeated. Vasoactive infusions and inspired oxygen fraction were held constant throughout the investigation. The results indicated that the major characteristics of the main mode of the VA/Q distributions (mean, standard deviation, and skew) were similar during all three modes. Dead space was lower during APRV (30.1 +/- 1.7% [SEM]) than during SIMV (36.2 +/- 1.5%) and PSV (37.1 +/- 2.7%) (p less than 0.05). Right-to-left shunt was significantly greater during APRV (19.9 +/- 2.3%) than during SIMV (15.4 +/- 1.7%) (p less than 0.05). Peak airway pressure (Paw) was higher during SIMV (32.8 +/- 1.3 cm H2O) than both PSV (19.4 +/- 2.1 cm H2O) and APRV (14.3 +/- 1.0 cm H2O) (p less than 0.05). Minute ventilation was lower during APRV (7.5 +/- 0.07 L/min) than during SIMV (9.4 +/- 0.6 L/min) and PSV (9.0 +/- 0.5 L/min) (p less than 0.05). Hemodynamic variables were similar during all three modes. We conclude that all three modes provide acceptable oxygenation and ventilatory support.

Results of emergent versus elective cardiac transplantation procedures.

Twenty-six patients underwent emergent (Group I) and 34 patients elective (Group II) cardiac transplantation (C. Tx.) from June 1985 through June 1989. Age, sex, etiology, presence of diabetes, renal failure and pulmonary artery pressures were comparable for both groups (P greater than 0.5). Twenty-two patients were in New York Heart Association (NYHA) Class IV for Group I and 17 for Group II. Group I included 12 patients on inotropic agents, five on intra-aortic balloon pump (IABP) and one on IABP and cardiopulmonary bypass (CPB). Elective patients were stable at home. Location of the donor heart and mean ischemic times were comparable for both groups. Early mortality (within 30 days) included four patients for Group I and two for Group II. There were four late deaths for Group I patients and six for Group II. Four deaths were due to infection, six to rejection, two to malignancy, two neurological and one each to suicide and multisystem failure. Immunosuppression regimen was similar for both groups. The number and severity of early and late rejection episodes were similar despite blood group crossing in 11 patients for Group I (P less than .01). Incidence of infection was comparable. Favorable lifestyles were comparable, including employment of 12 patients for Group I and 16 for Group II. Cumulative survival for the entire series was 70% at two years. The study indicates that the results of emergent and elective cardiac transplantation procedures are equally gratifying, that mortality is mainly related to rejection and sepsis complications and blood group crossing does not significantly increase the number of rejection episodes.

Harvesting, routing, and anastomosing the left internal mammary artery graft.

A technique to harvest, intrapleurally route, and anastomose the left internal mammary artery is described.

Metastatic mediastinal neoplasm masquerading as aortic dissection: a skip sign on computed tomography for their distinction.

Four years after undergoing a left lower lobe lobectomy for squamous cell carcinoma, a 77-year-old man presented with a mass lesion in the left upper mediastinum associated with chest pain. Computed tomography revealed a homogeneous density immediately adjacent to the aortic arch and thoracic aorta consistent with aortic dissection. Upon thoracotomy, however, the lesion was found to be an oat cell carcinoma. Retrospective review of the computed tomography scans detected a normal segment of descending aorta, indicating the interruption of the paraaortic lesion. Such a skip sign can be used to rule out aortic dissection.

Venous prostheses: improved patency with external stents.

A uniformly successful prosthesis for replacement in the venous system has not been developed. This study assesses the effect of external stents on the patency of polytetrafluoroethylene (PTFE) grafts in the infrarenal vena cava. Under general anesthesia, 21 mongrel dogs underwent midline laparotomy. The infrarenal vena cava was resected and replaced by a standard segment (8 cm X 10 mm) of stented PTFE (12 dogs) and nonstented PTFE (9 dogs). Patency was assessed by contrast venography and the results compared between the two groups. The 7-, 30-, and 90-day patency was 12/12, 10/12, and 9/12, respectively, for stented PTFE and 6/9, 2/9, and 2/9, respectively, for nonstented PTFE. The patency of externally stented PTFE at 30 and 90 days was significantly better than grafts fashioned from PTFE alone (P less than 0.05 by chi-square analysis). These data demonstrate that external stenting improves the early patency of PTFE prostheses in the infrarenal vena cava. Consideration should be given to the clinical use of externally stented PTFE when prosthetic replacement in the venous system is required.

Local thrombolytic therapy for subclavian and axillary vein thrombosis. Treatment of the thoracic inlet syndrome.

Four patients with primary subclavian-axillary vein thrombosis are described. Each patient received local thrombolytic therapy, resulting in reestablishment of antegrade flow via the axillary and subclavian veins. An intrinsic venous abnormality (perimural fibrosis and/or intimal dissection) identified at the first rib-clavicle junction (subclavian-axillary vein junction) was thought to be responsible for the thrombosis. One of the four patients subsequently underwent a surgical venous bypass of the abnormal segment, and a second underwent percutaneous transluminal angioplasty.

The prevention of extra cardiac conduit obstruction: an experimental study.

Acquired right ventricular (RV) extracardiac conduit (ECC) obstruction was studied in an animal model. A 16 mm woven Dacron tube graft was inserted between the right ventricle (RV) and main pulmonary artery (PA) in 18 adult mongrel dogs followed by pulmonary artery occlusion with a Dacron tape. In 9 dogs, the RV anastomosis was maintained with a 16 mm Dacron covered polypropylene stent. The remaining 9 animals with direct suture attachment of the graft to the myocardium served as controls. Cardiac output and transconduit resistance were measured at operation, 6 months, and 1 year. The cardiac output remained the same in both groups. Animals with stented ECC showed little change in transconduit resistance and had a widely patent RV anastomosis at 1 year. Unstented conduits had increased transconduit resistance at 6 months and 1 year (P less than 0.002). Postmortem examination showed fibromuscular ingrowth of the ventricular anastomosis to be the site of the acquired obstruction in unstented extracardiac conduits. The inclusion of a rigid stent in RV-ECC may warrant clinical application to prevent fibromuscular ingrowth and late RV anastomotic obstruction.

Prosthetic replacement for the thoracic vena cava: an experimental study.

The superior vena cava (SVC) and thoracic inferior vena cava (IVC) were replaced in 46 dogs with autologous vein, knitted Dacron, glutaraldehyde-fixed porcine pericardium, unsupported polytetrafluorethylene (PTFE), and externally stented PTFE. After 30 days, patency rates were determined by contrast venography and were 100%, 9%, 50%, 75%, and 100%, respectively. The patency rates of Dacron and glutaraldehyde-fixed pericardium are considered unacceptable when compared to autologous vein (p less than 0.05). Stented PTFE exhibited a patency rate equal to that of autologous vein at 30 days, minimal graft reaction, excellent incorporation by host fibroblasts, and a smooth neointima. The external spiral support added to PTFE enchanced the thromboresistance of this graft in the thoracic venous system. Long-term follow-up is required to determine if the stented PTFE prosthesis remains comparable to autologous vein as a venous conduit.

Suppurative thrombophlebitis in childhood.

Thrombophlebitis in children is almost always related to intravenous therapy. In most cases the inflammatory reaction is self-limited and resolves when the intravenous catheter or needle is removed. In some cases contamination may result in suppurative thrombophlebitis, a potentially life-threatening complication of intravenous therapy. This report describes two-6-year-old children with suppurative thrombophlebitis that was successfully treated by drainage of periphlebitic abscess and excision of the infected vein. Early recognition and prompt surgical management should reduce morbidity and prevent mortality in these cases.

Clinical spectrum of zinc deficiency in pediatric patients receiving total parenteral nutrition (TPN).

In a 1-yr period, 11 infants and children were found to have symptomatic zinc deficiency associated with prolonged total parenteral nutrition (TPN). A wide variety of signs and symptoms were due to zinc deficiency, including diarrhea, anorexia, poor weight gain, perioral and perineal rash, and alopecia. A previously undescribed symptom of zinc deficiency, that of prolonged postoperative adynamic ileus, was also seen in four children. Prompt resolution of symptoms occurred with the institution of intravenous zinc sulfate (500 micrograms/kg/day).