Noninvasive evaluation of hand circulation before radial artery harvest for coronary artery bypass grafting.

OBJECTIVE: Radial artery harvesting for coronary artery bypass may lead to digit ischemia if collateral hand circulation is inadequate. The modified Allen's test is the most common preoperative screening test used. Unfortunately, this test has high false-positive and false-negative rates. The purpose of this study was to compare the results of a modified Allen's test with digit pressure change during radial artery compression for assessing collateral circulation before radial artery harvest. METHODS: One hundred twenty-nine consecutive patients were studied before coronary artery bypass operations. A modified Allen's test was performed with Doppler ultrasound to assess blood flow in the superficial palmar arch before and during radial artery compression. A decreased audible Doppler signal after radial artery compression was considered a positive modified Allen's test. First and second digit pressures were measured before and during radial artery compression. A decrease in digit pressure of 40 mm Hg or more (digit DeltaP) with radial artery compression was considered positive. RESULTS: Seven of 14 dominant extremities (50%) and 8 of the 16 nondominant extremities (50%) with a positive modified Allen's test had a digit DeltaP of less than 40 mm Hg (false positive). Sixteen of 115 dominant extremities (14%) and 5 of 112 nondominant extremities (4%) with a negative Allen's test had a digit DeltaP of 40 mm Hg or more with radial artery compression (false negative). CONCLUSION: Use of the modified Allen's test for screening before radial artery harvest may unnecessarily exclude some patients from use of this conduit and may also place a number of patients at risk for digit ischemia from such harvest. Direct digit pressure measurement is a simple, objective method that may more precisely select patients for radial artery harvest. Additional studies are needed to define objective digital pressure criteria that will accurately predict patients at risk for hand ischemia after radial harvest.

Treatment options for perianal Bowen's disease: survery of American Society of Colon and Rectal Surgeons Members.

The aim of this study was to determine current management practices of physicians caring for patients with perianal Bowen's disease. A questionnaire was sent to 1,499 members listed in the 1997 American Society of Colon and Rectal Surgeons Directory asking them how many patients they have treated and which operative or nonoperative treatment option they choose for small (< or =3 cm), large (> 3 cm), and microscopic lesions. Of 1,499, 663 (44.2%) surgeons responded. Not all respondents answered each item. Seventy-five per cent of surgeons surveyed (n = 653) devote greater than 75 per cent of their practice to colon and rectal surgery. Of 642 respondents, 552 (86%) managed a total of <10 patients, and 90/642 (14%), > or =10 patients. Ninety-six per cent of respondents use wide local excision for patients with small lesions. Eighty-seven per cent of respondents use wide local excision for patients with large lesions. Seventy-four per cent treat patients with microscopic disease conservatively and without wide excision. The majority of surgeons caring for patients with perianal Bowen's disease are performing wide local excision for both small and large lesions. Microscopic disease was usually treated conservatively with observation alone.

Perianal Bowen's disease and anal intraepithelial neoplasia: review of the literature.

PURPOSE: The aim of this study was to review the literature with regard to perianal Bowen's disease and anal intraepithelial neoplasia. METHODS: A literature review was conducted from 1960 to 1999 using MEDLINE. RESULTS: Perianal Bowen's disease and anal intraepithelial neoplasia are precursors to squamous carcinoma of the anus. They are analogous to and are associated with cervical and vulvar intraepithelial neoplasia, and have human papillomavirus as a common cause. Biopsy and histopathologic examination is required for diagnosis and to distinguish other perianal dermatoses. Treatment options range from aggressive wide local excision of all disease with negative margins to observation alone for microscopic lesions not visible to the naked eye. The disease has a proclivity for recurrence and recalcitrance. CONCLUSIONS: Most surgeons caring for patients with perianal Bowen's disease and high-grade anal epithelial neoplasia use wide local excision, with an effort to obtain disease-free margins. Some authors have reported the advantages of ablative procedures such as laser ablation and cryotherapy. Microscopic disease found serendipitously in hemorrhoidectomy specimens can probably be treated conservatively with serial examinations alone. There is a lack of controlled data supporting an optimal treatment strategy. A multicenter controlled study comparing wide local excision with ablative procedures may be warranted.

Metronidazole may inhibit intestinal colonization with Clostridium difficile.

PURPOSE: Antibiotics suppress normal gut flora, allowing overgrowth of acquired or native Clostridium difficile, with release of toxins that cause mucosal inflammation. Oral metronidazole is used to treat antibiotic-associated colitis (pseudomembranous colitis). This study was designed to determine whether oral metronidazole, as part of preoperative bowel preparation, prevents or decreases incidence of antibiotic-associated colitis after elective colonic and rectal procedures. METHODS: Eighty-two patients (40 men) were prospectively, randomly assigned to receive one of two oral antibiotic regimens before colorectal surgery. All patients underwent mechanical bowel preparation with polyethylene glycol-electrolyte lavage solution before administration of oral antibiotics. Group 1 (n = 42) patients received three doses (1 g/dose) of neomycin and erythromycin. Group 2 (n = 40) patients received three doses (1 g/dose) of neomycin and metronidazole. Both groups received one preoperative and three postoperative doses of intravenous cefotetan (2 g/dose). Both groups had stool samples tested for C. difficile toxin in the preoperative and postoperative periods by enzyme-linked immunoabsorbent assay or by tissue culture cytotoxicity. Patients with preoperative stool studies positive for C. difficile were excluded from the study. RESULTS: Treatment groups were not different for age, gender, or surgical procedure. Mean age +/- 1 standard deviation was 67.6 +/- 13.6 (range, 34-94) years in Group 1 and 62.1 +/- 13.5 (range, 35-84) years in Group 2 (P = 0.069). Mean length of hospital stay +/- 1 standard deviation was 9.76 +/- 4.9 (range, 4-28) days for Group 1 and 8.05 +/- 2.6 (range, 3-14) days for Group 2 (P = 0.053). Five patients in Group 1 (neomycin and erythromycin) and one patient in Group 2 (neomycin and metronidazole) had positive stool studies for C. difficile. Relative risk of colonization with C. difficile in Group 1 was 4.76 times that in Group 2 (95 percent confidence interval, 0.581, 39). This difference was not statistically significant (P = 0.202). There were no significant differences in C. difficile colonization rates with respect to age, length of stay, or gender. CONCLUSIONS: This study suggests that there may be a clinical association between use of metronidazole preoperatively and inhibition of intestinal colonization by C. difficile in this patient population undergoing colonic and rectal surgery.