Outcomes after natural orifice extraction vs conventional specimen extraction surgery for colorectal cancer: A propensity score-matched analysis.

BACKGROUND: Natural orifice specimen extraction (NOSE) via the anus or vagina replaces conventional transabdominal specimen retrieval via the transabdominal route through a limited mid-line laparotomy or Pfannenstiel incision. Reducing the number of laparoscopic ports further decreases operative abdominal wall trauma. These techniques reduce the surgical wound size as well as the risk of incision-related morbidity. AIM: To compare short-term outcomes following 3-port NOSE surgery with a matched cohort of conventional non-NOSE colorectal cancer surgery. METHODS: Patients who underwent elective 3-port laparoscopic colorectal NOSE surgery between February to October 2021 were identified. Selection criteria for NOSE surgery was adapted from the 2019 International Consensus on Natural Orifice Specimen Extraction Surgery for colorectal cancer. Patients with clinical T4 or N2 tumors on staging computed tomography were also excluded. The propensity score-matched cohort was identified amongst patients who underwent conventional laparoscopic colorectal surgery from January 2019 to December 2020. Matching was performed in the ratio of 1:4 based on age, gender, type of resection, and p - tumor node metastasis staging. RESULTS: Over the eight-month study duration, 14 consecutive cases (nine female, five male) of elective 3-port laparoscopic surgery with NOSE were performed for colorectal cancer. Median age and body mass index were 70 (range 43-82) years and 24.1 (range 20.0-31.7) kg/m2 respectively. Six patients underwent transanal NOSE and eight had transvaginal NOSE. Median operative time, intraoperative blood loss and postoperative length of stay were 208 (range 165-365) min, 30 (range 10-150) mL and 3 (range 2-6) d respectively. Two (14%) suffered minor postoperative compilations not attributable to the NOSE procedure. Median follow-up duration was 12 (range 8-15) mo. No instances of mortality, local or distant disease recurrence were recorded in this cohort. Compared to the conventional surgery cohort of 56 patients, the 3-port NOSE cohort had significantly quicker mean return of bowel function (2.6 vs 1.2 d, P < 0.001), reduced postoperative pain and patient-controlled analgesia use, and decreased length of hospital stay (6.4 vs 3.4 d, P < 0.001). There were no statistical differences in surgical duration and perioperative complication rates between the NOSE and non-NOSE cohorts. CONCLUSION: 3-port laparoscopic colorectal surgery with NOSE is a feasible technique, augmenting the minimally invasive nature of surgery and producing good outcomes. Appropriate patient selection and expertise in conventional laparoscopy are required.

Time-varying prognostic effects of primary tumor sidedness and grade after curative liver resection for colorectal liver metastases.

BACKGROUND: The veracity of the proportional hazards (PH) requirement is rarely scrutinized in most areas of cancer research, although fulfilment of this assumption underpins widely-used Cox survival models. We sought to critically appraise the existence of prognostic factors with time-dependent effects and to characterize their impact on survival among CLM patients. METHODS: Consecutive patients who underwent liver resection with curative intent for CLM at the Singapore General Hospital were identified from a prospectively-maintained database. We evaluated PH of 55 candidate variables, and parameters which departed significantly from proportionality were included in Cox models that incorporated an interaction term to account for time-dependent effects. As sensitivity analyses, we fitted Weibull mixture 'cure' models to handle long plateaus in the tails of survival curves, and also analyzed the restricted mean survival time. RESULTS: 318 consecutive patients who underwent curative liver resection for CLM between Jan 2000 and Nov 2016 were included in this analysis. Hazard ratios for tumor grade (poorly-versus well- and moderately-differentiated) were found to decrease from 3.135 (95% CI: 1.637-6.003) at 12 months to 2.048 (95% CI: 1.038-4.042) after 24 months, and ceased to be significant at 26 months. Compared to left-sided tumors, a right-sided tumor location was found to portend worse prognosis for the first 10 months after resection but subsequently confer a survival benefit due to a crossing of survival curves. Corroborating this observation, long-term cure fractions were estimated to be 25.5% (95% CI: 17.4%-33.6%) and 34.2% (95% CI: 17.4%-50.9%) among patients with left-sided and right-sided primary disease respectively. CONCLUSION: Primary tumor sidedness and grade appear to exert time-varying prognostic effects in CLM patients undergoing curative liver resection.

Impact of multidisciplinary tumour boards (MTB) on the clinicopathological characteristics and outcomes of resected colorectal liver metastases across time.

BACKGROUND: Resection of colorectal liver metastases (CLM) has been established as the standard of care. This study aims to compare the change in clinicopathological characteristics of patients who underwent curative resection of CLM across two time periods-2000 to 2010 (P1) and 2011 to 2016 (P2) and evaluate the prognostic impact of these characteristics on survival outcomes. METHODS: Patients who undergo liver resection for CLM at Singapore General Hospital from January 2000 to December 2016 were identified from a prospectively maintained database. The primary end point was overall survival. RESULTS: There were 183/318 (57.5%) patients and 135/318 (42.5%) patients in P1 and P2, respectively. There was a lower proportion of patients who had nodal metastases from primary colorectal cancer and clinical risk score (CRS) less than 3 in P2 when compared to P1. There was no difference in survival between both time periods. Independent predictors of survival for the cohort were CEA levels ≥ 200 ng/ml, primary tumour grade and lymph nodal status. Independent predictors of poor survival in P1 were poorly differentiated colorectal cancer and nodal metastases while in P2, independent predictors of poor survival were multiple liver metastases and nodal metastases. CONCLUSION: Nodal metastases from primary colorectal cancer are an independent predictor of poor survival across time for resectable CLM. Although there is no difference in survival between the two time periods, patients with multiple liver metastases should be carefully considered prior to surgery as it is also an independent predictor of overall survival.

Novel use of the ClariVein® catheter for pharmacomechanical thrombolysis of thrombosed hemodialysis grafts: a case series.

INTRODUCTION: The aim of this prospectively collected case series is to demonstrate a novel technique of using the ClariVein® catheter for pharmacomechanical thrombolysis of thrombosed hemodialysis grafts. METHODS: The analysis comprised 11 procedures in 9 patients from 1 July to 31 December 2016 in which the ClariVein catheter was used in combination with urokinase. Demographic data, procedural data, technical and clinical success rates, and complications were evaluated. The primary and secondary patency rates at 1 and 3 months were also analyzed. RESULTS: In the 11 procedures performed, the technical and clinical success was 100%. The mean procedural time was 66.8 minutes (range 50-90 minutes), and the mean amount of urokinase administered was 87,000 units. The primary unassisted patency rates at 1 and 3 months were 81.8% and 63.6%, respectively. The secondary patency rates at 1 and 3 months were 90.9% and 81.8%, respectively. Perforation occurred after balloon angioplasty in 1 (9.1%) of the 11 procedures, for which covered stenting was performed. No major complications occurred. CONCLUSIONS: The combination use of the ClariVein catheter with urokinase for pharmacomechanical thrombolysis in thrombosed hemodialysis grafts is a feasible and safe method that can be performed in a relatively short duration. Our early results have shown 100% technical and clinical success. This case series serves as a platform for an upcoming prospective study to further evaluate this method.

Individual and Area Level Socioeconomic Status and Its Association with Cognitive Function and Cognitive Impairment (Low MMSE) among Community-Dwelling Elderly in Singapore.

BACKGROUND/AIMS: Neighborhood socioeconomic status (SES) can affect cognitive function. We assessed cognitive function and cognitive impairment among community-dwelling elderly in a multi-ethnic urban low-SES Asian neighborhood and compared them with a higher-SES neighborhood. METHODS: The study population involved all residents aged ≥60 years in two housing estates comprising owner-occupied housing (higher SES) and rental flats (low SES) in Singapore in 2012. Cognitive impairment was defined as <24 on the Mini Mental State Examination. Demographic/clinical details were collected via questionnaire. Multilevel linear regression was used to evaluate factors associated with cognitive function, while multilevel logistic regression determined predictors of cognitive impairment. RESULTS: Participation was 61.4% (558/909). Cognitive impairment was found in 26.2% (104/397) of residents in the low-SES community and in 16.1% (26/161) of residents in the higher-SES community. After adjusting for other sociodemographic variables, living in a low-SES community was independently associated with poorer cognitive function (ß = -1.41, SD = 0.58, p < 0.01) and cognitive impairment (adjusted odds ratio 5.13, 95% CI 1.98-13.34). Among cognitively impaired elderly in the low-SES community, 96.2% (100/104) were newly detected. CONCLUSION: Living in a low-SES community is independently associated with cognitive impairment in an urban Asian society.