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Biomedical subjects

B E Lewis

Publications and source records attributed to B E Lewis.

At least 55 records · Page 3Linked to original sources
PubMed1995

Predictors of successful PTCA using coronary perfusion balloon catheters.

The purpose of this retrospective study was to define clinical, angiographic and procedural predictors of successful PTCA using perfusion balloon catheters (PBC). Age, gender, diabetes, clinical state (stable or unstable angina), coronary vessel, AHA/ACC lesion type, lesion contour, pre-procedural thrombus, percent stenosis, lesion length, balloon size, maximum PBC pressure, and maximum inflation time were analyzed for 207 lesions in 193 successive patients. Unsuccessful results occurred more frequently in patients with unstable angina, pre-PTCA thrombus, and those treated with smaller balloon catheter diameter. Logistical regression analysis identified larger balloon size (odds ratio [OR] = 0.447 [95% confidence interval 0.203, 0.986], p < .05); and absence of thrombus (OR = 2.217 [95% confidence interval 1.066, 4.610], p < .05) as predictors of success. This study suggests that small vessel size, approximated by balloon size selection, and the presence of pre-PTCA thrombus reduces the likelihood of success, especially in the setting of unstable angina. In these cases other percutaneous interventions may be warranted.

Aged↗
PubMed1995

Assessment of outcome of bifurcation lesions and non-bifurcation lesions treated in the CAVEAT trial. CAVEAT investigator group.

Registry data suggests that bifurcation lesions are associated with reduced success during percutaneous revascularization. We studied 1012 CAVEAT patients to compare procedural outcomes in patients with and without bifurcation lesions whose target vessel was treated with either atherectomy or angioplasty. Bifurcation lesions have increased angiographic complexity and interventions on them are associated with lower acute procedural success rates compared to non-bifurcation lesions. Subgroup analysis suggests that atherectomy treatment of bifurcation lesions improves acute procedural success rates and lowers restenosis rates compared to angioplasty treatment of bifurcation lesions but atherectomy of bifurcation lesions is associated with higher acute complication rates than angioplasty of bifurcation lesions.

Adult↗
PubMed1994

Restenosis presented with unstable angina and myocardial infarction: one explanation for late cardiac events following directional coronary atherectomy.

Three cases of restenosis after directional coronary atherectomy (DCA) presented with unstable angina and then myocardial infarction. Two of them were complicated with malignant ventricular dysrhythmia. A total or subtotal thrombotic occlusion at the DCA site was shown. This fulminating course of restenosis could partially explain the higher late cardiac morbidity and mortality after DCA than after percutaneous transluminal balloon angioplasty.

Aged↗
PubMed1994

Acute procedural results in the treatment of 30 coronary artery bifurcation lesions with a double-wire atherectomy technique for side-branch protection.

Percutaneous treatment of bifurcation lesions has been consistently shown to be associated with lower acute success rates, higher initial complication rates, and an increased rate of restenosis when compared with findings in nonbifurcation lesions. Recent analysis of data from a CAVEAT subgroup suggests that directional atherectomy of bifurcation lesions can improve initial success rates and lower restenosis rates but at the cost of high complication rates. Reports from several angioplasty series document improved success rates and lower complication rates with the use of a two-wire technique to protect side branches when treating bifurcation lesions. Our experience with a two-wire atherectomy technique that uses a nitinol wire to protect important side branches is presented.

Adult↗
PubMed1994

Assessment of patient satisfaction as part of a physician performance evaluation: the Fallon Clinic experience.

Patient satisfaction surveys were used as part of the physician evaluation process in a 300-member physician group practice with a largely health maintenance organization (HMO) patient population. The surveys were incorporated into the review process at the request of physicians who wanted to be evaluated by patients. Results were shared with physicians to identify problem areas for improving patient care. One year later, follow-up surveys showed improvement in patient ratings of participating physicians. In addition, physicians indicated that the surveys significantly improved the evaluation process.

Data Collection↗
PubMed1994

Improved hemodynamic, angiographic and functional results after renal artery stenting.

Eighteen patients with severe renal artery atherosclerosis underwent conventional percutaneous transluminal renal angioplasty (PTRA) followed immediately by implantation of an endovascular stent. Hemodynamic measurements showed a baseline trans-stenotic pressure gradient of 78.3 mmHg that was reduced to 14.8 mmHg after PTRA. The post PTRA trans-stenotic pressure gradient was further reduced to 0.86 mmHg after stent placement. The average baseline diameter stenosis of 81.3% was reduced to 43.7% after PTRA and 6.1% after stent placement. Six month angiographic follow-up revealed restenosis in 6/16 patients. In patients treated for chronic renal insufficiency without restenosis the 6 month creatinine was 1.46 mg/dl compared to a pre-procedure creatinine of 2.4 mg/dl. Therefore those patients with renal insufficiency and renal artery stenosis who had long term patency after successful stent implantation showed significant improvement in renal function at six months. Stent implantation also significantly improved acute hemodynamic results and acute angiographic results compared to conventional renal artery angioplasty.

Aged↗
PubMed1994

Failure of ancrod in the treatment of heparin-induced arterial thrombosis.

The morbidity and mortality associated with heparin-induced thrombosis remain high despite numerous empirical therapies. Ancrod has been used successfully for prophylaxis against development of thrombosis in patients with heparin induced platelet aggregation who require brief reexposure to heparin, but its success in patients who have developed the thrombosis syndrome is not well defined. The authors present a case of failure of ancrod treatment in a patient with heparin-induced thrombosis.

Ancrod↗
PubMed1993

Examination of common PTCA guide wires used for side branch protection during directional coronary atherectomy of bifurcation lesions performed in vivo and in vitro.

Side branch protection of bifurcation lesions with guide wires treated with directional coronary atherectomy has been performed safely in a small number of patients using a nickel/titanium (Nitinol) alloy guide wire. There is no information about the safety of using other guide wires in this scenario. The purpose of this study was to microscopically examine a variety of guide wires exposed to the directional coronary atherectomy (DCA) device in vitro. Eight common guide wires used in percutaneous coronary angioplasty were positioned in a side branch of a simulated coronary bifurcation and exposed to the operating DCA device. The guide wires were examined grossly and under scanning electron microscopy. The Nitinol guidewire suffered no discernible damage in comparison to varying degrees of damage seen on the other guide wires, and this guidewire appears to be best suited for side branch protection. Examination of the protecting guide wire and cutting cylinder used in the initial patients also showed no damage. Further clinical trials are necessary to assess the efficacy of DCA under such conditions.

Angioplasty, Balloon, Coronary↗
PubMed1992

Health maintenance organizations and the treatment of substance abuse.

The deterioration of substance abusers to the point where they need to be hospitalized generally happens slowly, over a period of years if not decades. During this time, most of their medical care takes place in an ambulatory setting. Primary care physicians are thus in an ideal position to identify and help patients in relatively early stages of the problem. The HMO, with its ability to practice patient-oriented case management and its access to all aspects of the medical care delivery system without additional financial burden to the patient, is particularly suited to provide effective and efficient care. The next challenge for HMOs is to reach patients at much earlier stages of their disease.

Age Factors↗
PubMed1988

Medicare patients and alternatives to the acute care hospital.

There are many instances where hospitalized elderly patients no longer need intensive hospital care but are not ready to be discharged. One solution to this dilemma is the use of a skilled nursing facility (SNF) or some type of step-down bed, where patients can continue to receive managed care at a less intense and costly level. A major concern with using step-down beds is that while costs may be controlled, quality of care may suffer and patient outcomes may be jeopardized. From an efficiency perspective, the step-down bed can provide an excellent alternative to hospital care for the less acutely-ill patient. For alternative managed care environments to be satisfactorily received by patients and physicians, however, they must produce outcomes equal or better than those in the hospital. Some patients and diagnoses are more appropriate than others for treatment in alternative managed care environments. The judgement of appropriateness must take into account patient and physician satisfaction with the efficiency and effectiveness of the care. This paper describes how the Fallon Community Health Plan, Worcester, Mass., which regularly uses a step-down facility for patient care, assessed outcomes in terms of efficiency and effectiveness. An overview of this alternative managed care facility and its relationship to the HMO is discussed below. Several studies examining outcomes and patient and physician satisfaction are presented. Finally, the ways in which these studies represent a merger of quality assurance (QA) and utilization review (UR) methodologies are discussed.

Aged↗