Risk factors for wound infection after cholecystectomy.

BACKGROUND AND PURPOSE: Surgical site infection (SSI) after cholecystectomy is a common problem. The aim of this study was to identify the possible risk factors for the development of SSI. METHODS: 545 consecutive patients who received open (125) or laparoscopic (420) cholecystectomy due to gallbladder disease during the years 1998 to 2000 were included in the study. Potential risk factors including clinical features, biochemical data, and operative types were analyzed by univariate and multivariate analysis. RESULTS: The overall incidence of SSI was 4.4% (24/545). The wound complication rate was significantly lower in the laparoscopic group than in the open group (1.4% vs 14.4%, respectively). Factors associated with SSI found by univariate analysis (p < 0.05) included age, gender, acute cholecystitis, white blood cell count, serum albumin, blood glucose and bilirubin level, type of surgery, operative time and positive bile culture. Stepwise logistic regression analysis showed that abnormal blood glucose [odds ratio (OR), 4.7; 95% confidence interval (CI), 1.6 to 13.5], positive bile culture (OR, 3.5; 95% CI, 1.2 to 10.4), and open cholecystectomy (OR, 4.3; 95% CI, 1.3 to 13.6) were the most significant predictors of SSI. CONCLUSION: Poor control of diabetes mellitus before surgery, positive bile culture and open cholecystectomy significantly increased the rate of SSI. These findings indicate that better control of diabetes mellitus, and appropriate selection of surgical procedure and antibiotic regimen in the management of high-risk patients may reduce the incidence of postoperative SSI.     

Percutaneous microwave coagulation therapy under ultrasound guidance for small hepatocellular carcinoma.

BACKGROUND AND PURPOSE: Percutaneous microwave coagulation therapy (PMCT) can effectively treat hepatocellular carcinomas (HCCs) smaller than 2 cm. However, for tumors 2 to 3 cm in size, combination of transarterial chemoembolization (TACE) or multiple insertions of electrodes may be more effective. This study investigated the treatment efficacy of PMCT for tumors 2 to 3 cm in size. METHODS: Nineteen HCCs smaller than 3 cm in diameter (< 2 cm in 11, and 2-3 cm in 8) in 18 patients (including 14 previously treated patients) were treated by PMCT under ultrasound guidance. One or 2 PMCT electrodes were consecutively inserted either into the left and right portion, or into the distal and proximal portion of the tumor, according to the size, shape, and margin of tumors and puncture direction. Liver function tests and contrast-enhanced computed tomography were used to examine preoperative status and response to PMCT. RESULTS: After an average of 1.6 emissions of PMCT, 18 tumors (95%) were completely ablated. The only case of treatment failure was due to a tumor location which made the approach of the electrode difficult. Bacteremia developed after the procedure in 1 patient (5%) and local inflammatory reaction of the puncture wound in another (5%). During follow-up ranging from 5 to 19 months, no recurrence was noted at the site of the original tumors. Tumor recurrence was detected at another site 2-9 months after PMCT in 9 of the 14 previously treated patients. CONCLUSION: PMCT can effectively and safely treat HCCs smaller than 3 cm in size without combination of TACE or multiple insertions of electrodes.     

Solar disinfection of water for diarrhoeal prevention in southern India.

AIMS: To evaluate the efficacy and acceptability of solar irradiation in the prevention of diarrhoeal morbidity in children under 5 years of age, in an urban slum in Vellore, Tamil Nadu. METHODS: A total of 100 children were assigned to receive drinking water that had been subjected to solar disinfection in polyethylene terephthalate bottles. One hundred age and sex matched controls were also selected. Both groups were followed by weekly home visits for a period of six months for any diarrhoeal morbidity. At the end of the follow up period, the acceptability of the intervention was assessed by interviews, questionnaires, and focus group discussions. RESULTS: There was significant reduction in the incidence, duration, and severity of diarrhoea in children receiving solar disinfected water, despite 86% of the children drinking water other than that treated by the intervention. The incidence of diarrhoea in the intervention group was 1.7 per child-year, and among controls 2.7 per child-year, with an incidence rate ratio of 0.64 (95% CI -0.48 to 0.86). The risk of diarrhoea was reduced by 40% by using solar disinfection. In qualitative evaluation of acceptability, most women felt that solar disinfection was a feasible and sustainable method of disinfecting water. CONCLUSIONS: Solar disinfection of water is an inexpensive, effective, and acceptable method of increasing water safety in a resource limited environment, and can significantly decrease diarrhoeal morbidity in children.     

Histologic changes in the eustachian tube mucosa of rats after short-term exposure to cigarette smoke.

OBJECTIVE AND BACKGROUND: It is generally accepted that cigarette smoke is a major risk factor for middle ear disease. However, the literature is void of articles addressing the direct relationship between cigarette smoke exposure and middle ear disease. Furthermore, there are many conflicting opinions concerning the role of cigarette smoke in the pathogenesis of middle ear disease. The purpose of this study was to evaluate the effects of cigarette smoke on the Eustachian tube mucosa. MATERIALS AND METHODS: Thirty healthy 150 to 230 g Sprague Dawley rats with normal middle ears were used. The animals were divided into six groups of five. Five experimental groups (N=5 each) were exposed to a domestic cigarette (This, tar 7.0 mg, nicotine 0.75 mg) every 30 minutes (total 2.5 hours, 5 cigarettes total) on a daily basis in a smoking chamber for 1, 2, 4, 6, or 8 weeks. A control group (N=5) was placed in the same chamber without exposure to cigarette smoke. After exposure, the animals were sacrificed and cross sections of the Eustachian tubes were prepared. Histologic changes of the Eustachian tube mucosa were observed through light and electron microscopes. RESULTS: Loss of cilia, goblet cell depletion, and squamous metaplasia of the Eustachian tube mucosa were observed following exposure to smoke. The one- and two-week exposure groups demonstrated the greatest decrease in goblet cell counts. The eight-week exposure group showed recovery from this decrease. Squamous metaplasia was observed in all experimental groups and was most prominent in the eight-week exposure group. CONCLUSION: These findings suggest that cigarette smoke directly affects Eustachian tube mucosa in the early stages of exposure. Some of the mucosal changes, however, were reversed during the latter stages of exposure. A mechanism different from that which occurs in the nasal cavity and trachea may be activated in the Eustachian tube after exposure to passive smoke. The protective function of the Eustachian tube may play some role in this mechanism.     

Validation of a computer-based bronchoscopy simulator developed in Taiwan.

BACKGROUND/PURPOSE: Conventional training in bronchoscopy may increase patient's discomfort and procedure-related morbidity. Computer-based bronchoscopy simulator (CBBS) permits the acquisition and evaluation of the necessary skills through a realistic bronchoscopic experience. This study was conducted to validate the use of a CBBS system developed in Taiwan as a learning and assessment tool. METHODS: Twenty novice bronchoscopists and 10 expert bronchoscopists were enrolled as subjects in this prospective study. The 20 novice bronchoscopists were randomized into two groups, which received conventional bronchoscopic training or CBBS training and then completed a satisfaction survey. Subsequently, the novices who received CBBS training underwent an observational performance trial and the results were compared with those of expert bronchoscopists. All 10 expert bronchoscopists completed a realism survey and observational trial after CBBS performance. RESULTS: The satisfaction survey showed that the CBBS training program significantly increased participants' satisfaction (p = 0.002) and interest in learning (p < 0.001). The realism survey by the 10 expert bronchoscopists indicated that CBBS provides a favorable degree of realism with regard to the mechanical and visual parameters examined. Analysis of the performance results showed that the following parameters were capable of differentiating the participants by level of expertise: total procedure time (p = 0.002), percentage of bronchial segments entered (p = 0.012), percentage of bronchial segments identified (p < 0.001), percentage of repeated bronchial segments entered (p = 0.004), percentage of pathologies identified (p < 0.001), number of times that the bronchoscope tip collided with airway walls (p = 0.013), and number of times oral instruction was needed (p = 0.01). CONCLUSION: CBBS is a valid training method that increases interest in learning and provides a favorable degree of virtual realism. It can also distinguish various levels of competence at actual bronchoscopy and may have a useful role in the bronchoscopic training curriculum.     

Adventitial cystic disease.

Adventitial cystic disease (ACD) is an unusual cystic tumor of blood vessels characterized by the accumulation of mucinous substance in the adventitia of the non-axial blood vessels adjacent to joints. Patients with ACD often suffer from intermittent claudication and/or limb pain, mostly involving the popliteal artery. We report a 30-year-old male who presented with intermittent claudication in his left leg. Angiography showed an obstructive lesion in the left popliteal artery. The lesion was treated successfully by surgical excision followed by graft vessel replacement. ACD involving the popliteal artery was diagnosed by pathologic findings of multiple cysts of the adventitia with external compression and focal narrowing of the vascular lumen. The cysts contained acid mucin and were partially lined by multiple rows of cytologically bland, synovium-like cells with positive immunoreactivity to vimentin and CD68 but negative immunoreactivity to cytokeratin. The histopathologic findings in this case suggest that it was caused by the developmental rests of mucin-secreting mesenchymal cells derived from the knee joint.     

Differential sensitivity of sodium channel isoforms and sequence variants to pyrethroid insecticides

Pyrethroids are commonly regarded as safe insecticides. However, some widely used pyrethroids, particularly single neurotoxic isomers of potent Type II compounds, have acute oral toxicities comparable to many organophosphorus insecticides. The majority of studies of the action of pyrethroids on voltage-sensitive sodium channels, the principal target sites for these compounds, have not considered differences in sodium channel structure as determinants of sensitivity. In mammals, voltage-sensitive sodium channels are encoded by a multi-gene family and exhibit both anatomical and developmental regulation of expression. Studies in this laboratory using cloned rat sodium channel isoforms expressed in Xenopus oocytes have documented profound differences in pyrethroid sensitivity between isoforms. Although the role of sodium channel gene mutations in altering pyethroid sensitivity has not been addressed in the case of the mammalian sodium channel gene family, the potential significance of allelic variation is illustrated in studies of point mutations in a sodium channel gene of the house fly that confer resistance to the lethal actions of pyrethroids and modify the sensitivity of house fly sodium channels expressed in Xenopus oocytes to these compounds. It is of particular interest that some of these resistance-associated mutations in the fly sodium channel occur at amino acid residues that are also the sites of mutations in human skeletal muscle sodium channels that are associated with inherited paralytic disorders. These findings document the pharmacological significance of structural differences between sodium channel isoforms and between genetic variants of an individual isoform as determinants of pyrethroid sensitivity.