Surgeon assessment of significant rectal polyps using white light endoscopy alone and in comparison to fluorescence-augmented AI lesion classification.

PURPOSE: Perioperative decision making for large (> 2 cm) rectal polyps with ambiguous features is complex. The most common intraprocedural assessment is clinician judgement alone while radiological and endoscopic biopsy can provide periprocedural detail. Fluorescence-augmented machine learning (FA-ML) methods may optimise local treatment strategy. METHODS: Surgeons of varying grades, all performing colonoscopies independently, were asked to visually judge endoscopic videos of large benign and early-stage malignant (potentially suitable for local excision) rectal lesions on an interactive video platform (Mindstamp) with results compared with and between final pathology, radiology and a novel FA-ML classifier. Statistical analyses of data used Fleiss Multi-rater Kappa scoring, Spearman Coefficient and Frequency tables. RESULTS: Thirty-two surgeons judged 14 ambiguous polyp videos (7 benign, 7 malignant). In all cancers, initial endoscopic biopsy had yielded false-negative results. Five of each lesion type had had a pre-excision MRI with a 60% false-positive malignancy prediction in benign lesions and a 60% over-staging and 40% equivocal rate in cancers. Average clinical visual cancer judgement accuracy was 49% (with only 'fair' inter-rater agreement), many reporting uncertainty and higher reported decision confidence did not correspond to higher accuracy. This compared to 86% ML accuracy. Size was misjudged visually by a mean of 20% with polyp size underestimated in 4/6 and overestimated in 2/6. Subjective narratives regarding decision-making requested for 7/14 lesions revealed wide rationale variation between participants. CONCLUSION: Current available clinical means of ambiguous rectal lesion assessment is suboptimal with wide inter-observer variation. Fluorescence based AI augmentation may advance this field via objective, explainable ML methods.

Prognostic value of pre-operative mean corpuscular volume (MCV) in colorectal cancer.

BACKGROUND: Mean corpuscular volume (MCV) has been shown to have some correlation to oncological outcomes in oesophageal cancer, with high pre-operative MCV associated with disease recurrence. A similar association has previously been reported in colorectal cancer. AIMS: This study is aimed at investigating whether high MCV bears similar relation to post-operative outcome and disease recurrence in colorectal cancer (CRC). METHODS: Patients undergoing elective CRC resection with curative intent between January 2008 and December 2019 were identified from our prospective database. Review of patient demographic details, American Society of Anaesthesiologists (ASA) grade, smoking and alcohol intake were performed. In addition, tumour location and staging, operation performed, pre-operative laboratory data and oncological management of each patient were noted. Post-operative morbidity (Clavien-Dindo (CD) score > 2), 30-day mortality, in-hospital mortality and cancer recurrence were examined and multivariable regression analysis was performed to predict these outcomes. RESULTS: A total of 1,293 CRCs were resected, with 1,159 patients (89.7%) experiencing a hospital course without major morbidity (CD < 3). 30-day mortality rate was less than 1% (12/1293). There were 176 patients (13.6%) with recurrence at follow-up. When multivariable regression analysis was performed, high pre-operative MCV did not predict negative post-operative or oncological outcomes. CONCLUSION: MCV does not appear to be an independent prognostic factor for outcomes following elective CRC resection.

Sigmoid volvulus: definitive surgery is safe and should be considered in all instances.

BACKGROUND: Acute sigmoid volvulus (ASV) represents a small but significant portion of cases of large bowel obstruction, especially in the elderly and co-morbid. Given the characteristics of the patient cohort most commonly affected, a non-operative/conservative approach is often undertaken but is associated with a high rate of recurrence. OBJECTIVE: We sought to evaluate outcomes for those patients who underwent non-operative management, emergency surgery or staged, semi-elective surgery following decompression for ASV at our institution. METHODS: Hospital in-patient enquiry (HIPE) data were used to identify all patients who presented with sigmoid volvulus between January 2005 and June 2020 inclusive. Patient notes were interrogated, including surgical and endoscopic procedures performed. Patient demographics and co-morbidities were recorded. RESULTS: Thirty-nine patients were treated over a 15-year period with a mean age of 73 years at first presentation (range 36-93). Twenty-two patients (56%) had just a single admission for ASV with three deaths in this group. Seventeen patients (44%) had more than one admission with volvulus due to recurrence after a decompression-only strategy on the index admission. Of these, three succumbed to complications of their subsequent episodes of volvulus. Twenty-five patients underwent surgical intervention (fifteen on, or shortly following, their first admission and ten following at least two admissions for ASV). The overall mortality in the operative group was 2/25 (8%) with both deaths in those undergoing emergency surgeries. Five patients were treated successfully with endoscopic measures alone and had required no further interventions at the time of compiling data. CONCLUSION: There is a high recurrence rate following non-operative management of acute sigmoid volvulus and consequently, a cumulative increase in the attendant significant morbidity and mortality with subsequent episodes. Given the relatively low complication rate of definitive surgery, even in those patients perceived to be high risk, we contend that all patients should be considered for early surgery to prevent the likely recurrence of sigmoid volvulus.