Factors contributing to recurrent carotid disease following carotid endarterectomy.

BACKGROUND: Retrospective analysis was performed to assess the effect of gender, age, hypertension, diabetes, and smoking upon residual disease, recurrent disease, and progression of disease following carotid endarterectomy (CE). The effect of patch versus primary closure was also studied. METHODS: Postoperative duplex studies were performed following 323 CEs at months 1, 6, 12, and 24. Residual disease was defined as luminal stenosis >59% at 1 month. Progression of disease was defined as stenosis at any month that was greater than stenosis at month 1. Recurrent disease was nonresidual stenosis >79%. RESULTS: Correlation was found between age at operation <65 years and cigarette smoking; both also correlated with progression of disease on serial studies, as well as recurrent stenosis <79%. Primary closure of the arteriotomy correlated with residual disease. CONCLUSION: Primary closure of the arteriotomy following CE increases the likelihood of residual disease. Smokers and those aged <65 years are predisposed to progression of postoperative disease, and to development of recurrent stenosis.

Allograft replacement of the aortic valve for active endocarditis.

PURPOSE: In the 50 months preceding March 1995, 35 adult patients underwent aortic valve replacement with a cryopreserved human aortic valve allograft. Nine of these patients had active endocarditis. The remaining 26 patients had aortic valve pathology without active infection. This study consists of a comparison of these two groups. METHODS: One of the patients with active infection underwent inclusion technique replacement of the infected valve. The other eight valves were replaced with root-replacement technique. Of the 26 non-infected patients, 4 valves were replaced with the inclusion technique, and the remaining 22 were replaced with the root-replacement technique. None of the patients are maintained on long-term anti-coagulation. RESULTS: We have followed the infected group an average of 32 months and the group without active infection has been followed an average of 27 months. There were two perioperative deaths in the nine patients with infected valves and no deaths in the group without active infection (Pearson's chi2 p<0.05). There have been no thromboembolic complications and no recurrent infections.

Durability of emergency coronary artery bypass for complications of failed angioplasty.

Although emergency coronary artery bypass for complications of percutaneous transluminal coronary angioplasty (PTCA) has proved to be a relatively successful 'bail-out' procedure, little is known about the durability of revascularization under these potentially disastrous circumstances. The authors therefore retrospectively examined their results with this procedure. Emergency coronary artery bypass for complications of PTCA was performed in 112 patients between 1 January 1984 and 19 May 1992. Fifteen patients underwent PTCA for acute myocardial infarction. Eleven patients (9.8%) were stable, and underwent emergency coronary artery bypass after PTCA because of suboptimal angiographic results from percutaneous transluminal coronary angioplasty. None of these stable patients died. The remainder of the patients underwent emergency coronary artery bypass after PTCA because of ongoing documented ischemia, including cardiac arrest requiring cardiopulmonary resuscitation during transit to the operating room in 11 patients (9.8%) and preoperative intra-aortic counterpulsation in 24 (21.4%). The average number of coronary arteries bypassed at emergency coronary artery bypass was 2.2, and 19 patients (17%) received at least one mammary artery conduit. The perioperative incidence of myocardial infarction was 8.9% (10/112), and the operative mortality rate 8% (9/112). During follow-up, which averaged 55 months, the survival rate (including operative mortality) was 85% while 98% of patients experienced freedom from reoperative coronary bypass, 89% experienced freedom from myocardial infarction (including postoperative) and 90% experienced freedom from subsequent catheterization or PTCA. In conclusion, emergency coronary artery bypass for PTCA complications successfully avoids subsequent untoward cardiac events. When compared with published results of PTCA without emergency coronary artery bypass, emergency coronary bypass is more reliable for avoiding subsequent cardiac catheterization (with or without PTCA) than PTCA alone.

Clinical heparin coated cardiopulmonary bypass: reduction of systemic heparin requirements for redo cardiac surgery.

The authors compared blood loss, transfusion requirements, and heparin doses for reoperative cardiac surgery using either: a) a Duraflow (Baxter Corporation, Irvine, CA) heparin coated cardiopulmonary bypass (CPB) system or b) standard CPB. Twenty patients underwent redo cardiac surgery while supported with heparin coated CPB, and 17 patients underwent redo cardiac surgery with standard CPB. The following data are presented as mean +/- standard deviation. The heparin coated CPB circuit group received significantly less heparin than the standard CPB group (322 +/- 80 IU/kg versus 448 +/- 80 IU/kg, p < 0.01). There was no difference in blood loss in the first 24 postoperative hrs or mean transfusion requirements for the two groups. Despite the reduced dose of heparin, the mean activated clotting time in the heparin coated group was similar to the mean activated clotting time of the standard CPB group (577 +/- 98 sec versus 612 +/- 117 sec, p = ns). In conclusion, heparin coated CPB without reduced activated clotting time does not reduce transfusion requirements or blood loss in reoperative cardiac surgery. The heparin coated CPB system allows maintenance of the activated clotting time level despite reduced heparin doses.

Prophylaxis of heart transplant rejection with either antithymocyte globulin-, Minnesota antilymphocyte globulin-, or an OKT3-based protocol.

We compared an equine antithymocyte globulin (ATGAM)-based protocol with a Minnesota antilymphocyte globulin (MALG)-based protocol and a murine monoclonal CD-3 (OKT-)-based protocol in 3 groups of heart transplant (HT) recipients. Thirty-four recipients received a four-day course of ATGAM. Thirty HT recipients received a 14-day course of OKT3. Fifteen HT recipients received MALG for an average of 10 days. The ATGAM group received cyclosporine beginning preoperatively, while the OKT3 and MALG groups received CyA beginning on post-transplant day 4. All three groups received identical azathioprine and similar steroid therapy. The 3 groups were similar in age, donor/recipient HLA mismatches, and donor/recipient gender mismatches. The MALG and OKT3 groups had 20% and 17% females, respectively, while the ATG group had 41% (p < 0.05). Average follow-up exceeded 14 months for each group. The ATGAM group received a higher dose of CyA during "induction" therapy than the OKT3 and MALG groups, and experienced a greater rise in post-transplant serum creatinine levels. We found no difference between the 3 groups in: preoperative creatinine levels, one-year post-transplant creatinine levels, number of patients who could be successfully "weaned" from steroids, or one-year survival. Other data are tabulated as episodes/patient: [table: see text] We conclude that ATG plus preoperative CyA is superior for rejection prophylaxis following heart transplantation when compared with either MALG plus postoperative CyA or OKT3 plus postoperative CyA.

Acute repair of a full-thickness right ventricular defect with a composite myofascial pedicle flap.

A full-thickness defect of the right ventricle presented acutely after mediastinitis and sternal dehiscence. This developed 29 days after bilateral internal mammary artery harvest for coronary artery bypass grafting. The defect was managed successfully with a pedicled left rectus abdominis muscle flap using an attached island of the anterior rectus sheath for endocardial lining. The vascular anatomic basis for viability of the rectus abdominis muscle flap after internal mammary artery harvest is derived primarily from musculophrenic, lumbar, lower sixth intercostal, and subcostal artery communications. In addition, the advantages of a myofascial pedicle flap for reconstruction of full-thickness cardiac defects are its ready availability and a strong anterior fascial sheath that can be used as a neoendocardial lining. The patient did well and remains asymptomatic after 3 years.

Intraluminal shunting of operatively severed aortocoronary saphenous vein grafts.

Restoration of myocardial perfusion using plastic shunts in severed aortocoronary bypass grafts is described.

Prevention of pericardial adhesions with dextran 70.

Pericardial adhesions pose a major problem during reoperative cardiac surgical procedures. The purpose of this study was to determine the effect of intrapericardial dextran 70 on the formation of pericardial adhesions in an animal model. The data obtained revealed that intrapericardial dextran 70 reduced the incidence of experimental pericardial adhesions.

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.

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.