An Anechoic Space at the Carpal Tunnel Inlet is a Consistent Ultrasonographic Entity which Accommodates Tendon Displacement during Finger Flexion.

BACKGROUND: We consistently observed the presence of anechoic spaces on standard ultrasonographic imaging of the carpal tunnel inlet in normal subjects. These spaces change in size during finger flexion and have not been characterized in a large sample of normal individuals. Ultrasonographic quantification of these spaces may indicate the available space in the region of the carpal tunnel, which allows the normal motion of tendons and the median nerve. METHODS: Transverse ultrasonographic images of the carpal tunnel inlet from 33 asymptomatic volunteers were obtained at Position A (fingers in extension) and B (fingers in flexion). Cross-sectional area (CSA), perimeter and position of anechoic space relative to median nerve were recorded. RESULTS: Analysis showed a 75.4% prevalence rate of a single anechoic space. Two discrete patterns were observed. 89.1% had a decrease in CSA and perimeter of anechoic space from Position A to B while 10.9% exhibited an increase. Mean position of the anechoic space is ulnar (7.49 ± 3.57 mm) and dorsal (2.18 ± 1.28 mm) to the median nerve. CONCLUSIONS: A consistent anechoic space at the carpal tunnel inlet is seen in 75.4% of normal hands and can be quantified (cross sectional area 11.75 ± 7.36 mm(2)). It allows for the accommodation of flexor tendons during finger flexion.

Post-operative aspirin use and colorectal cancer-specific survival in patients with stage I-III colorectal cancer.

BACKGROUND: Recent observational studies suggest that postoperative aspirin use may improve Colorectal cancer (CRC)-specific survival and overall survival (OS). In this study, we aimed to assess the effects of aspirin use on outcomes in a predominantly Asian cohort of patients with CRC. PATIENTS AND METHODS: Case records of patients undergoing curative resection for stage I-III CRC were retrieved for clinical data and patterns of aspirin use and vital data were determined from hospital electronic prescription records, hospital pharmacy dispensing records, national clinical and prescription databases. CRC-specific and recurrence-free survival (RFS) amongst aspirin users and non-users were analyzed and compared using the Cox proportional hazards model. RESULTS: Out of 726 patients with CRC, 103 were regular aspirin users and 623 were non-users. The median age of the cohort was 65 years (range=22-94 years) and the majority of patients were Chinese (90%). Nineteen percent, 31% and 47% had stage I, II and III CRC respectively; tumor staging was unknown for 3%. After adjusting for prognostic factors (age, stage, lymph node stage, grade, lesion site, perineural invasion, lymphvascular invasion), the risk of CRC relapse or death from CRC was approximately 60% lower compared to patients who were not postoperative aspirin users (Hazard Ratio=0.38, 95% Confidence Interval=0.17-0.84, p=0.017). No benefit was observed for preoperative use of aspirin. CONCLUSION: In this single-Institution study, with long-term follow-up of patients with stage I-III-resected CRC, postoperative aspirin use was associated with reduced risk of relapse of and death from CRC.