Association of mechanical bowel preparation with oral antibiotics and anastomotic leak following left sided colorectal resection:an international, multi-centre, prospective audit

Introduction: The optimal bowel preparation strategy to minimise the risk of anastomotic leak is yet to be determined. This study aimed to determine whether oral antibiotics combined with mechanical bowel preparation (MBP+Abx) was associated with a reduced risk of anastomotic leak when compared to mechanical bowel preparation alone (MBP) or no bowel preparation (NBP). Methods: A pre-planned analysis of the European Society of Coloproctology (ESCP) 2017 Left Sided Colorectal Resection audit was performed. Patients undergoing elective left sided colonic or rectal resection with primary anastomosis between 1 January 2017 and 15 March 2017 by any operative approach were included. The primary outcome measure was anastomotic leak. Results: Of 3676 patients across 343 centres in 47 countries, 618 (16.8%) received MBP+ABx, 1945 MBP (52.9%) and 1099 patients NBP (29.9%). Patients undergoing MBP+ABx had the lowest overall rate of anastomotic leak (6.1%, 9.2%, 8.7% respectively) in unadjusted analysis. After case-mix adjustment using a mixed-effects multivariable regression model, MBP+Abx was associated with a lower risk of anastomotic leak (OR 0.52, 0.30–0.92, P = 0.02) but MBP was not (OR 0.92, 0.63–1.36, P = 0.69) compared to NBP. Conclusion: This non-randomised study adds ‘real-world’, contemporaneous, and prospective evidence of the beneficial effects of combined mechanical bowel preparation and oral antibiotics in the prevention of anastomotic leak following left sided colorectal resection across diverse settings. We have also demonstrated limited uptake of this strategy in current international colorectal practice

Evaluating the incidence of pathological complete response in current international rectal cancer practice

The mainstay of management for locally advanced rectal cancer is chemoradiotherapy followed by surgical resection. Following chemoradiotherapy, a complete response may be detected clinically and radiologically (cCR) prior to surgery or pathologically after surgery (pCR). We aim to report the overall complete pathological response (pCR) rate and the reliability of detecting a cCR by conventional pre-operative imaging.A pre-planned analysis of the European Society of Coloproctology (ESCP) 2017 audit was performed. Patients treated by elective rectal resection were included. A pCR was defined as a ypT0 N0 EMVI negative primary tumour; a partial response represented any regression from baseline staging following chemoradiotherapy. The primary endpoint was the pCR rate. The secondary endpoint was agreement between post-treatment MRI restaging (yMRI) and final pathological staging.Of 2572 patients undergoing rectal cancer surgery in 277 participating centres across 44 countries, 673 (26.2%) underwent chemoradiotherapy and surgery. The pCR rate was 10.3% (67/649), with a partial response in 35.9% (233/649) patients. Comparison of AJCC stage determined by post-treatment yMRI with final pathology showed understaging in 13% (55/429) and overstaging in 34% (148/429). Agreement between yMRI and final pathology for T-stage, N-stage, or AJCC status were each graded as 'fair' only (n = 429, Kappa 0.25, 0.26 and 0.35 respectively).The reported pCR rate of 10% highlights the potential for non-operative management in selected cases. The limited strength of agreement between basic conventional post-chemoradiotherapy imaging assessment techniques and pathology suggest alternative markers of response should be considered, in the context of controlled clinical trials

Endoscopic Versus Radiology-Based Location of Rectal Cancer

Background : Rigid proctosigmoidoscopy is recommended for measuring the height of rectal neoplasms but appears to be performed in only a minority of patients. Our aim was to compare endoscopic and radiological measurement of rectal tumour location with a focus on differentiation between mid and high rectal cancer. Methods : Medical records of 66 rectal cancer patients were reviewed. Tumour location defined at colonoscopy (66 patients), rigid proctosigmoidoscopy (20 patients) and endorectal ultrasound (35 patients) was recorded. Rectilinear and curvilinear methods were used to estimate the distance between the lower tumour level and the anal verge on sagittal CT or MR images (66 patients). Agreement, intra- and inter-observer variation of radiology-based measurements were assessed using intra-class correlation (ICC) and within-subject coefficient of variation (WSCV). Results : Tumour location was performed at rigid proctosigmoidoscopy in 30% of patients. Intra- and inter-observer agreement for radiology-based measurements were high. Tumour location using the rectilinear method or proctosigmoidoscopy was similar on average, for a difference of only 0.34 cm (SD 2.0cm, p = 0.330), although agreement was moderate (ICC = 0.54, WSCV = 16.7%). Measurements based on colonoscopy and the curvilinear radiological method were characterized by a systematic overestimation of the location, increasing with tumour height. Conclusions : Radiology-based measurement of the lower tumour level is a reproducible alternative for tumour location at rigid or flexible endoscopy. Its validity should be further assessed

Endoscopic Versus Radiology-Based Location of Rectal Cancer

Background : Rigid proctosigmoidoscopy is recommended for measuring the height of rectal neoplasms but appears to be performed in only a minority of patients. Our aim was to compare endoscopic and radiological measurement of rectal tumour location with a focus on differentiation between mid and high rectal cancer. Methods : Medical records of 66 rectal cancer patients were reviewed. Tumour location defined at colonoscopy (66 patients), rigid proctosigmoidoscopy (20 patients) and endorectal ultrasound (35 patients) was recorded. Rectilinear and curvilinear methods were used to estimate the distance between the lower tumour level and the anal verge on sagittal CT or MR images (66 patients). Agreement, intra- and inter-observer variation of radiology-based measurements were assessed using intra-class correlation (ICC) and within-subject coefficient of variation (WSCV). Results : Tumour location was performed at rigid proctosigmoidoscopy in 30% of patients. Intra- and inter-observer agreement for radiology-based measurements were high. Tumour location using the rectilinear method or proctosigmoidoscopy was similar on average, for a difference of only 0.34 cm (SD 2.0cm, p = 0.330), although agreement was moderate (ICC = 0.54, WSCV = 16.7%). Measurements based on colonoscopy and the curvilinear radiological method were characterized by a systematic overestimation of the location, increasing with tumour height. Conclusions : Radiology-based measurement of the lower tumour level is a reproducible alternative for tumour location at rigid or flexible endoscopy. Its validity should be further assessed

High-density biosynthetic fuels: the intersection of heterogeneous catalysis and metabolic engineering

Renewable multicyclic sesquiterpenes were converted into high density fuels with net heats of combustion up to 13% higher than Jet-A.</p