A systematic review of mechanical thromboprophylaxis in the lithotomy position.

BACKGROUND: Venous thrombosis and compartment syndrome are potentially serious complications of prolonged, lithotomy position surgery. It is unclear whether mechanical thromboprophylaxis in this group of patients modifies the risk of compartment syndrome. This qualitative systematic review examines the evidence base to guide clinical practice. METHOD: A systematic review was performed guided by Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) criteria, to identify studies reporting relationships between lithotomy position, compartment syndrome and mechanical thromboprophylaxis. The aim was to determine if mechanical thromboprophylaxis influenced compartment syndrome risk in the lithotomy position. RESULTS: Sixteen studies were identified: eight case reports or case series (12 patients), two completed audit cycles (approximately 2000 patients), four reviews and two volunteer case control studies (33 subjects). There were no randomised studies. Nine studies associated mechanical thromboprophylaxis with compartment syndrome risk but in each case a causative relationship was speculative. In contrast, five papers, including an experimental, cohort study and two observational, population studies recommended intermittent pneumatic compression as prevention against compartment syndrome in lithotomy position. One review and one case report were unable to make a recommendation. CONCLUSIONS: The level of evidence addressing the interaction between the lithotomy position, compartment syndrome and mechanical thromboprophylaxis is weak. There is no conclusive evidence that mechanical thromboprophylaxis causes compartment syndrome in the lithotomy position. There is limited evidence to suggest intermittent pneumatic compression may be a safe method of mechanical thromboprophylaxis if accompanied by strict adherence to other measures to reduce the chance of compartment syndrome. However further studies are required.

Evaluation of autofluorescence colonoscopy for the detection and diagnosis of colonic polyps.

BACKGROUND: Colorectal cancer is the second most common cause of death in the United Kingdom. Most cancers are believed to arise within preexisting adenomas. Although colorectal adenomas have a clear neoplastic potential, hyperplastic polyps do not. It, therefore, would be helpful to be able to differentiate between different polyps at a colonoscopy. Autofluorescence (AF) endoscopy has been developed to enhance conventional white light (WL) endoscopy in the diagnosis of GI lesions. OBJECTIVE: The aim of the present study was to evaluate whether AF colonoscopy can facilitate endoscopic detection and differentiation of colorectal polyps. DESIGN: Patients were invited to attend for colonic assessment with both AF and WL endoscopy. AF readings, pictures, and biopsy specimens were taken of any visible pathology and of any high AF areas. SETTING: Gartnavel General Hospital, Glasgow, U.K. PATIENTS: A total of 107 patients were assessed. INTERVENTION: Each patient was assessed with AF and WL colonoscopy. MAIN OUTCOME MEASUREMENTS: An AF intensity ratio (AIR) was calculated for each polyp (ratio of direct polyp AF reading/background rectal AF activity). RESULTS: A total of 75 polyps were detected: 54 adenomatous and 21 hyperplastic polyps. Colorectal adenomas had a significantly higher AIR compared with hyperplastic polyps (median, interquartile range): adenoma (3.54, 2.54-5.00] versus hyperplastic (1.60, 1.30-2.24); P = .0001). When using an AIR with the empirically cutoff value of 2.3, AF endoscopy had a sensitivity of 85% and a specificity of 81% at distinguishing adenomatous polyps from hyperplastic polyps. CONCLUSIONS: AF colonoscopy may be a valuable tool for the visual distinction between adenomatous and hyperplastic polyps.