Biomedical subjects
Publications and source records attributed to M B Douthit.
A recurrent left ventricular false aneurysm 5 years after patch repair and causing progressive congestive heart failure was readily diagnosed by echocardiography and heart catheterization. Its substrate was suture dehiscence of undetermined origin. Urgent repair was successful. The long-term prognosis is guarded.
Contradictory results have been reported regarding risk factors for aortic valve replacement (AVR). This study was designed to investigate determinants of operative mortality for AVR with emphasis on concomitant coronary artery bypass grafting (CABG) and old age. Between January 1986 and June 1992, 371 patients with a mean age of 61.99 +/- 0.76 years underwent AVR. There were 256 men (69.0%) and 115 women (31.0%). Twenty-six patients (7.0%) were 80 years old or older, and 97 (26.1%) were between 70 and 80 years old. Of these patients, 210 (56.6%) had isolated AVR, 142 (38.3%) had concomitant CABG, and 31 (8.4%) had concomitant mitral valve operations. Twenty patients (5.4%) underwent emergency operation. There were 33 operative deaths (8.9%). Univariate analysis and stepwise multiple logistic regression analysis were used to determine the risk factors for operative mortality. In the univariate analysis, 13 preoperative variables (sex, age, history of congestive heart failure, myocardial infarction, arrhythmia, functional class, class I/II versus III/IV, four variables related to aortic valve pathology, ejection fraction, left ventricular function) and 20 perioperative variables (emergency operation, individual surgeon, myocardial protection by type and route of cardioplegia, type of prosthesis, size of prosthesis, mean size by survival, small versus large size, concomitant procedure, concomitant CABG (versus others or AVR alone), concomitant mitral valve operation (versus others or AVR alone), concomitant CABG and MV operation, aortic cross-clamp time, cardiopulmonary bypass time, use and time of insertion of intraaortic balloon pump, low cardiac output, postoperative complications) were examined.(ABSTRACT TRUNCATED AT 250 WORDS)
1. The internal mammary artery has become a preferred coronary bypass graft. Sympathomimetic amines are spasmogens for vasospasm and calcium antagonists are frequently administered drugs perioperatively. The effect of calcium antagonists on alpha-adrenoceptor-mediated contraction depends on the subtype of alpha-adrenoceptor and the type of origin of vascular smooth muscle. This study was designed to investigate the effect of calcium antagonists on alpha-adrenoceptor-mediated contraction in the IMA. 2. Human IMA segments taken from 22 patients undergoing IMA--coronary artery bypass grafting were mounted in an organ bath under the physiological pressure determined from their own length-tension curves. 3. Three ring segments were allocated into three groups. One served as a control and the others were treated with clinically related concentrations of nifedipine (20 or 200 nM) for 25 min before concentration-contraction curves to alpha 1-adrenoceptor agonist methoxamine (MO) or full alpha-adrenoceptor agonist noradrenaline (NA) were established. 4. In separate experiments, the concentration-relaxation curves to nifedipine were established in the IMA rings precontracted with MO (30 microM) or NA (10 microM). Glyceryl trinitrate (GTN, 3 microM) was added to further relax the vessels. 5. Pretreatment with nifedipine (200 nM) only slightly inhibited the MO- (1.74 +/- 0.32 vs 2.88 +/- 0.56 g) or NA- (2.43 +/- 0.66 vs 3.60 +/- 0.82 g) induced contraction without statistical significance (P > 0.05). 6. On the other hand, nifedipine only caused 34.49% relaxation in the MO-precontracted and 24.39% relaxation in the NA-precontracted IMAs. In contrast, GTN caused 76.16% (against MO, P < 0.05) or 92.22% (against NA, P < 0.0001) relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)
Coronary artery bypass grafting has been performed for elderly patients (> or = 70 years) with increasing frequency. From January 1986 through June 1993, 1399 elderly patients underwent isolated coronary bypass grafting. Of these patients, 823 had saphenous vein grafts alone and 576 had internal mammary artery grafting, including unilateral (n = 546) and bilateral (n = 28). Overall operative mortality was 8.86%. Operative mortality for unilateral internal mammary artery grafting (6.41%) was lower than for saphenous vein grafting only (9.96%, p = 0.021) and bilateral internal mammary artery grafting (21.43%, 6/28, p = 0.018). Fewer patients undergoing internal mammary artery grafting had postoperative complications (low cardiac output, intraaortic balloon pumping, and neurologic complications) than patients having saphenous vein grafting only. To determine risk factors for mortality and the influence of internal mammary artery grafting on the outcome, we analyzed 55 variables (27 preoperative, 15 intraoperative, and 13 postoperative) by univariate analysis. Significant variables (age, gender, height, weight, surface area, diabetes, obesity, body mass index, history of congestive heart failure, myocardial infarction, or arrhythmia, functional class, left ventricular ejection fraction, stenosis of the left anterior descending or right coronary artery, emergency operation, reoperation, number of grafts, perfusion time, and bilateral or right internal mammary artery grafting) were included in a stepwise multiple logistic regression analysis. The logistic regression demonstrates that those preoperative (history of congestive heart failure or myocardial infarction, low ejection fraction, female gender, and old age), intraoperative (long cardiopulmonary bypass time, emergency operation, reoperation, and use of right internal mammary artery grafting), and postoperative (postoperative complications) variables are independently associated with higher mortality. This study reveals the high-risk groups in elderly patients undergoing coronary bypass and suggests that a left internal mammary artery graft in combination with saphenous vein grafting may achieve a lower operative mortality and morbidity than other procedures in selected elderly patients undergoing coronary artery bypass grafting.
To investigate risk factors for operative mortality and sternal infection in patients undergoing bilateral internal mammary artery grafting, we analyzed the data of 199 patients who underwent this procedure from January 1986 through June 1992. These patients were also compared with those who underwent only saphenous vein grafting (1664 cases) and those who underwent unilateral internal mammary artery grafting (3359 cases) during the same time frame. The operative mortality was 3.52% (7/199) in the patients having bilateral internal mammary artery grafting, 2.71% (91/3359) in those having unilateral internal mammary artery grafting, and 8.53% (142/1664) in the patients having saphenous vein grafting (p < 0.0001). The occurrence rate of sternal infections was 2.45% (5/199) for bilateral internal mammary artery grafting, 1.32% (13/1664) for saphenous vein grafting, and 1.19% (20/3359) for unilateral internal mammary artery grafting (p = 0.27). The univariate analysis revealed that age, history of congestive heart failure, emergency operation, ejection fraction, and aortic crossclamp time were significantly correlated with operative mortality and that obesity was correlated with sternal wound infection. Stepwise multiple logistic regression identified that old age (> or = 70 years) (p < 0.0001), long perfusion time (p < 0.0001), and emergency operation (p = 0.0004) are risk factors for operative mortality and that obesity (p = 0.0009) is the only significant risk factor for sternal wound infection. We conclude that bilateral internal mammary artery grafting does not increase operative mortality in properly selected patients. However, this procedure should be carefully chosen in elderly (> or = 70 years) patients and for emergency operation. Obese patients have a high risk for sternal infection after bilateral internal mammary artery grafting.
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Since thoracoscopy was originally described in 1910, the application has been limited mainly to the diagnosis and treatment of pleural disease. Recent advancements in endoscopic equipment and refinement of surgical techniques have expanded the application of this procedure. Using video thoracoscopic techniques in 70 patients over the past 9 months, we have been able to perform a variety of procedures previously accomplished by "open" techniques. These procedures include (1) wedge resections of pulmonary nodules in 21 patients, using endoscopic mechanical stapling devices; (2) excision of the pericardium and drainage of the pericardial space in 6 patients; (3) dorsal thoracic sympathectomy in 6 patients; (4) apical blebectomy and pleurodesis in 6 patients; (5) lung biopsies for diagnosis of diffuse lung disease in 5 patients. Additional procedures performed include biopsy of hilar masses (3), biopsy of esophageal mass, excision of a mediastinal cyst, and the drainage of a spinal abscess. The remaining 20 procedures were performed for the diagnosis and treatment of pleural disease. There was no mortality associated with the procedure and morbidity was lessened, compared with standard thoracotomy procedures. The postoperative hospital stay after elective procedures performed in well patients averaged 3 days and was often as short as 1 day. Our experience indicates a markedly expanded role for thoracoscopy in the diagnosis and treatment of thoracic diseases with less postoperative morbidity.
One hundred and sixty-six patients with complicated and uncomplicated urinary tract infections were randomized to therapy with either 0.25, 0.50 or 1.00 g of ceftazidime im or iv twice daily for five days. Bacteriological data were complete in 138 patients. Escherichia coli caused 50% of all infections, Klebsiella and Enterobacter spp. caused 10.9%, Pseudomonas spp caused 10.9%, Proteus spp. caused 10.7%, and 8.7% were caused by other Gram-negative bacteria. Staphylococcus and Streptococcus spp. caused 9.4%. Cure rate was lowest in infections caused by Pseudomonas (53.3%) and Proteus spp. (64.3%); however, most of these infections were complicated. No significant dose-related difference in efficacy was observed, but the 0.25 g dose had the lowest cure rate in each category. Nausea was the only side effect. The most common laboratory abnormalities were elevated liver function tests. Minimal changes in haematological and renal function were seen.