Quadruple Assessment using Transrectal Ultrasound Scan is Effective at Accurately Facilitating Choice of Excision Plane by Tems in the Complex Specc Lesion

Background: There is currently no consensus as to the optimal imaging modality for Significant Polyps and Early Colorectal Cancer (SPECC). This study describes the use of transrectal ultrasound (TRUSS) as part of a quadruple assessment process to evaluate the depth of invasion of SPECC lesions and guide local excision. Method: Pre-operative imaging and histology were reviewed for all patients undergoing transanal endoscopy microsurgery (TEMS) at Cheltenham General Hospital between 2013 and 2019. Treatment options included mucosectomy, partial thickness excision and full thickness excision. The dataset was studied specifically to evaluate the risk that malignancy will be present at the deep margin. ‘Failure’ of assessment was thus defined as the failure to detect and achieve complete local excision of malignancy. Results: 400 patients were included: 319 primary lesions and 81 secondary lesions. Amongst the primary lesions 93.7% (n=299) had successful R0 excisions. Of the primary lesions with incomplete excisions 50% (N=10) had undergone mucosectomy, 40% (n=8) full thickness excision and 10% (n=2) partial thickness excision