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Biomedical subjects

J W Lea

Publications and source records attributed to J W Lea.

At least 19 recordsLinked to original sources

Myocardial bridge as a cause of thrombus formation and myocardial infarction in a young athlete.

We report here a young male athlete who had an acute myocardial infarction after strenuous exercise. Coronary angiography clearly demonstrated thrombus formation within a prominent myocardial bridge. Periarterial resection surgery was performed, which resulted in resolution of the angiographic "milking" effect of muscle bridge. Our observation, along with previous reports, suggests that myocardial bridges should be added to the list of known causes of sudden death or myocardial infarction in young persons after strenuous exercise. Thrombus formation within a myocardial bridge may be a potential mechanism whereby this anatomic curiosity may cause a tragic clinical event.

Adult↗

Ventricular aneurysmectomy. A 25-year experience.

OBJECTIVE: This study determined predictors of operative survival and improved long-term outcomes in patients undergoing ventricular aneurysmectomy. SUMMARY BACKGROUND DATA: Since the first successful repair of ventricular aneurysm in 1958, refined technique and improvement in perioperative care have been introduced to lower morbidity and mortality. METHODS: The authors reviewed their institutional experience from 1968 through 1993 in treating 523 patients who underwent ventricular aneurysmectomy. RESULTS: Overall operative mortality was 8% and overall median survival was 128 months. Contractility grade, age, and year of operation were predictors of operative mortality and of improved long-term survival. Type of aneurysm repair was not a strong predictor of operative mortality or improved long-term survival. CONCLUSIONS: Ventricular aneurysmectomy can be performed safely using one of a number of established techniques, although operative mortality and long-term survival may not depend on the techniques used.

Adult↗

Videothoracoscopy: improved technique and expanded indications.

Current videoendoscopic technology and percutaneous techniques of exposure and dissection have been successfully applied to abdominal surgery with favorable results. Application of this technology to our practice of thoracoscopy is the basis of this report. Videothoracoscopy has been performed in 39 patients for the following indications: chronic pleural effusion, interstitial lung disease, mediastinal lymphadenopathy in lung cancer, persistent air leak after decortication, mediastinal mass, recurrent spontaneous pneumothorax, hydropneumothorax with persistent air leak, and pleural-based mass. The technique we employ includes lateral decubitus positioning and double-lumen endotracheal intubation with ipsilateral lung collapse. The videoscope, retractors, and instruments are introduced through separate 10-mm incisions. Percutaneous manipulation of instruments and the videoscope is guided by images produced on television screens without dissection, and if resection is performed, the incision is enlarged to allow specimen retrieval. Procedures performed using this technique include pleural biopsy, partial pleurectomy, lysis of adhesions, lung biopsies, staging lymph node biopsy, lung nodule biopsy, pleural-based mass resection, and mediastinal mass biopsy and resection. This videoendoscopic technique greatly improves visualization of thoracic anatomy, facilitating thoracoscopy and enhancing exploration of the chest. It is preferred over conventional thoracoscopy and, in some patients, reduces the magnitude of operation by avoiding thoracotomy.

Adult↗

Internal mammary artery graft at reoperation: risks, benefits, and methods of preservation.

To determine the effect of a prior internal mammary artery (IMA) graft on coronary artery bypass reoperation (CABR), we reviewed our experience with 410 consecutive patients: 313 received only saphenous vein grafts at initial coronary artery bypass grafting (CABG), and 97 received at least one IMA graft at CABG. Cardiac catheterization data before CABG were available in 110 patients (56 received only saphenous vein grafts, 54 received at least one IMA graft), allowing comparison of left ventricular function at CABG and CABR. Injury of the IMA graft occurred in 5 patients (1 death), but presence of an IMA graft was not an independent predictor of morbidity or mortality. Overall, the incidences of complications and deaths were higher in patients with saphenous vein grafts than in patients with IMA grafts, though not significantly so. Internal mammary artery grafts better preserved cardiac function: patients with IMA grafts had worse left ventricular function before CABG but better left ventricular function before CABR than patients with saphenous vein grafts. Left ventricular function deterioration from before CABG to before CABR was significantly less in patients with IMA grafts. We conclude that the risk of CABR is not increased by a previously constructed IMA graft and that left ventricular function is better preserved at CABR when an IMA graft was constructed at the initial operation.

Confounding Factors, Epidemiologic↗

Emergency coronary bypass not associated with preoperative cardiogenic shock in failed angioplasty, after thrombolysis, and for acute myocardial infarction.

We have reviewed the literature and supplemented it with our own experience to provide a current viewpoint on emergency coronary bypass in three settings in which cardiogenic shock did not exist preoperatively. Acute failure of coronary angioplasty led to emergency operation in 701 patients with 25 (3.6%) deaths. There was a 37.6% incidence of perioperative infarction. Thrombolytic therapy for acute myocardial infarction, sometimes followed by angioplasty, led to emergency operation within 8 hours in 145 instances with four (2.1%) deaths. Emergency coronary bypass was primary therapy for 1,051 patients with acute myocardial infarction with 51 (4.9%) hospital deaths. Emergency operation for failed angioplasty is frequently mandated in the setting of surgical standby and iatrogenic ischemia although some operations could be postponed to an elective status. Emergency operation after thrombolytic therapy has been used for unsuccessful angioplasty of the infarct vessel, left main stenosis of greater than 50%, left main equivalent, multivessel disease with complex lesions not amenable to angioplasty, or failure to restore patency of the infarct vessel with thrombolysis. Operation within 12 hours of thrombolytic therapy is associated with a coagulopathy causing increased bleeding, the need for transfusion, and a greater incidence of reoperation for perioperative bleeding.

Angioplasty, Balloon↗

Efficacy of cefazolin, cefamandole, and gentamicin as prophylactic agents in cardiac surgery. Results of a prospective, randomized, double-blind trial in 1030 patients.

In an effort to develop an improved regimen of antibiotic prophylaxis in cardiac surgery, 1030 patients who were to have elective cardiothoracic surgery involving a median sternotomy were selected at random to receive cefamandole or cefazolin, with or without gentamicin, in a prospective double-blind study. Cefazolin was significantly less effective than cefamandole at both the sternal (1.8% vs. 0.4%, respectively, p less than 0.05) and donor sites (1.3% vs. 0%, respectively, p less than 0.02). Seven Staphylococcus aureus infections occurred among cefazolin recipients as compared with no such infections among the patients receiving cefamandole (p less than 0.01). All five wound infections yielding fungi or gentamicin-resistant gram-negative rods occurred in patients who had received gentamicin as a second prophylactic agent. These data suggest that gentamicin has no role as a prophylactic antibiotic in cardiac surgery and that, compared with cefamandole, cefazolin offers unreliable prophylaxis against deep infection at both the sternal and donor sites.

Cardiac Surgical Procedures↗

Internal mammary artery grafts: technical factors influencing patency.

Eight hundred fourteen patients with internal mammary artery (IMA) coronary artery bypass grafts have been restudied 961 times with coronary arteriography, primarily to evaluate the patency of the grafts in the setting of symptomatic coronary occlusive disease. Their records were reviewed to assess graft patency as related to the technical aspects of coronary artery bypass surgery. Patency was evaluated using life-table analysis of the data. The method of harvesting the IMA played no role in patency. The left anterior descending coronary artery was the recipient coronary artery with the highest patency rate. The left IMA had a significantly higher patency rate than the right IMA. As a group, the IMAs had a significantly higher patency rate than saphenous vein grafts. However, there was no difference between right IMA grafts and saphenous vein grafts. The mammary artery grafts that remained patent throughout the study had a significantly higher blood flow after bypass than did those that became occluded (43.0 +/- 0.9 versus 28.9 +/- 1.8 ml/min; p less than .001).

Blood Flow Velocity↗

The questionable role of computed tomography in preoperative staging of esophageal cancer.

The findings of computed tomography (CT) in 18 patients with histologically proven esophageal carcinoma were compared with operative and pathological findings. Computed tomography delineated esophageal lesions in 14 of the 18 patients. In 11 patients, CT scanning was found to be inaccurate in assessing tumor involvement of esophageal lymphatic drainage. Nine patients had no abdominal nodal metastasis demonstrated by CT scan. Operative exploration revealed tumor involvement of celiac or left gastric lymph nodes in all of these patients. Two patients' CT scans demonstrated tumor involvement of celiac and left gastric lymph nodes; at operative exploration, these nodes were enlarged, but they were histologically negative for esophageal carcinoma. Operative exploration changed the preoperative TNM classification in 8 of the 11 patients. Review of these data indicates that surgical exploration continues to be the only reliable method of determining the actual extent and often the resectability of esophageal carcinoma.

Adenocarcinoma↗

Chronic lymphocytic leukemia and other chronic lymphoid proliferations: surface marker phenotypes and clinical correlations.

A diagnosis of chronic lymphocytic leukemia (CLL) was made in 81 patients referred for peripheral blood lymphocyte typing (PBL). A retrospective review was undertaken to see if correlations existed between surface marker phenotype-determined subclasses and clinical features. Surface markers utilized were surface immunoglobulin (sIg), sheep erythrocyte receptor (E), 65,000-dalton human T lymphocyte antigen (T65), Ia antigen, and for sIg+ cells, heavy and light chains. All patients were Ia+. Cells of 70% of patients were sIg+ E- T65+ Ia+, and the clinical heterogeneity was that of classical CLL. Eight of the nine patients with sIg+ E- T65- Ia+ cells had a paraprotein. The sIg- E+ T65+ Ia+ phenotype represented classical T cell CLL. Three of the five patients in the sEg- E- T65+ Ia+ group had significant albuminuria, and two had nephrotic-range proteinuria. Use of additional monoclonal antibodies to B cell surface antigens should further subclassify CLL and other lymphoproliferative disorders. Interesting clinical correlations with certain phenotypic subclasses do exist, and further subclassification and long-term follow-up may yield correlations between phenotypes and prognosis.

Antigen-Antibody Complex↗

Content bias in the neoplastic-related items of the National Board of Medical Examiners Part II Examination.

The Education Evaluation Committee of the American Association for Cancer Education (AACE) attempted to employ the neoplastic-related items from the National Board of Medical Examiners (NBME) Part II examination in a study correlating program characteristics at various medical schools with performance on the neoplastic-related items. All questions on the September, 1977 and April, 1978 NBME Part II examinations were reviewed by board certified medical oncologists who found an approximate 20% discordance between the AACE and NBME classifications. Content analysis of the neoplastic-related items disclosed a preponderance of questions related to gynecologic cancer with few questions concerning the major solid tumors: lung, breast and colorectal cancer. In addition, virtually no questions related to the psychologic impact of cancer or to the therapy of cancer were asked. We conclude that the use of item by item performance scores from the neoplastic-related items is inadequate for program analysis due to disagreements over what constitutes such an item and to content bias in the agreed upon items. We propose a coding system that may allow the results from current NBME examinations to be used in program evaluation.

Curriculum↗

Surgical experience with carcinoma of the colon and rectum.

From September 1925 through December 1978 at Vanderbilt University Hospital, 1,279 patients with adenocarcinoma of the colon and rectum underwent operations. Reports of this cumulative series have been published previously; the last report in 1970 included 1,022 patients. The current report examines the progress made in our recognition and management of colorectal cancer. During this 54-year period, there has been a relative decrease in the incidence of carcinoma of the rectum and a relative increase in carcinomas elsewhere in large bowel. Resectability rate has steadily increased, culminating in a rate of 98.4% in the recent period (1969-1978). The operative mortality rate fell to 4.3% (1956-1960) but has shown a slight rise to 5.4% in the recent period (1969-1978). This reflects the increased number of patients in the eighth to the tenth decades of life. Five-year survival rates in 99% of 1,218 patients were computed. Absolute five-year survival for the recent period was 43.7%, compared with 17% for the initial period. Five-year survival rates for patients in the recent decade with Dukes A, B, and C lesions were 67%, 58.6%, and 33.3%, respectively. Comparison of survival data in the last two decades shows little improvement. However, in the last 20 years, 78 to 80% of patients had more advanced lesions.

Aged↗

Non-cross-resistant chemotherapy and consolidation radiotherapy for small cell carcinoma of the lung.

Fifty-six patients with small cell carcinoma of the lung were treated with a two-cyclic induction course of hexamethylmelamine, vincristine, doxorubicin, and cyclophosphamide. Patients with limited disease (LD) who responded and patients with extensive disease (ED) who had a complete response received prophylactic whole-brain radiotherapy, as well as radiotherapy to thoracic and abdominal sites of disease. Concurrently with radiotherapy, consolidation chemotherapy was given with doxorubicin, cyclophosphamide, methotrexate, and etoposide. The complete response rate was 35% for ED patients and 68% for LD patients. The median survival time for complete responders was 54 weeks for ED patients and 65 weeks for LD patients. The toxicity of the program was moderate, and the effectiveness was comparable to that of other reported combined-modality treatment programs.

Adult↗

Surgical experience with retrogastric and retropancreatic pheochromocytomas.

From 1972 to 1981 at Vanderbilt University Hospital there were seven patients with midline retrogastric or retropancreatic pheochromocytomas. Each of these tumors arose between the aorta and the inferior vena cava. This report details the difficulties in localization before and at operation in the smaller tumors in these sites. Our experience suggests that small midline pheochromocytomas in these sites may be readily missed by computerized tomographic scan, aortography, or surgical search at laparotomy unless subtraction arteriograms are used and the Kocher maneuver is employed at operation routinely.

Adolescent↗

Effects of betazole hydrochloride and cimetidine on common bile pressure and duodenal myoelectric activity in the dog.

Betazole hydrochloride, a histamine analogue that stimulates the H2 receptor, causes an immediate and significant increase in common bile duct pressure. This pressure elevation correlates with an increase in duodenal myoelectric activity. Both the duodenal myoelectric activity and common bile duct pressure immediately returned to near baseline following the administration of cimetidine, an H2 blocker.

Animals↗

Typhlitis: a treatable complication of acute leukemia therapy.

Heretofore, pseudomembranous enterocolitis, or more specifically typhlitis, occurring as a complication of the cytotoxic chemotherapy of acute leukemia has nearly always resulted in a fatal outcome. Recent surgical literature states that if cecitis is found as a consequence of therapy for leukemia, the surgeon should refrain from operating because standard procedures, including hemicolectomy, have not improved survival. This paper reports two patients with acute typhlitis resulting from induction therapy of acute leukemia with cytosine arabinoside and hydroxydaunorubicin. Both patients underwent subtotal colectomy, while their marrows were aplastic from therapy, and survived their surgery. Both are living and well in maintained remission, 1 year from surgery. We review the pathogenesis of this disorder and discuss its clinical, x-ray, and laboratory features. Close oncologic/surgical teamwork is stressed as the patient is followed closely into the time frame when the decision is made whether to operate. Factors contributing to this decision are discussed. Preoperative recommendations are made in order to bring the patient into a state of physiologic stability. The operative procedure is described along with the postoperative complications encountered. We strongly recommend that laparotomy be considered in selected patients with typhlitis occurring as a complication of treated leukemia.

Adolescent↗

Strategies in instructional materials development for African health professionals.

An international program in health professions training has involved the development of a teaching materials library by teams of African faculty authors and U.S. instructional materials specialists. Communications difficulties and differences in culture and technology have made it necessary that the instructional designers develop new production and management strategies, in order to meet program objectives and to assure the quality of the teaching materials. These strategies would seem to have continuing applications to domestic as well as international instructional development programs.

Africa↗