A systematic review of automated segmentation of 3D computed-tomography scans for volumetric body composition analysis.

Automated computed tomography (CT) scan segmentation (labelling of pixels according to tissue type) is now possible. This technique is being adapted to achieve three-dimensional (3D) segmentation of CT scans, opposed to single L3-slice alone. This systematic review evaluates feasibility and accuracy of automated segmentation of 3D CT scans for volumetric body composition (BC) analysis, as well as current limitations and pitfalls clinicians and researchers should be aware of. OVID Medline, Embase and grey literature databases up to October 2021 were searched. Original studies investigating automated skeletal muscle, visceral and subcutaneous AT segmentation from CT were included. Seven of the 92 studies met inclusion criteria. Variation existed in expertise and numbers of humans performing ground-truth segmentations used to train algorithms. There was heterogeneity in patient characteristics, pathology and CT phases that segmentation algorithms were developed upon. Reporting of anatomical CT coverage varied, with confusing terminology. Six studies covered volumetric regional slabs rather than the whole body. One study stated the use of whole-body CT, but it was not clear whether this truly meant head-to-fingertip-to-toe. Two studies used conventional computer algorithms. The latter five used deep learning (DL), an artificial intelligence technique where algorithms are similarly organized to brain neuronal pathways. Six of seven reported excellent segmentation performance (Dice similarity coefficients > 0.9 per tissue). Internal testing on unseen scans was performed for only four of seven algorithms, whilst only three were tested externally. Trained DL algorithms achieved full CT segmentation in 12 to 75 s versus 25 min for non-DL techniques. DL enables opportunistic, rapid and automated volumetric BC analysis of CT performed for clinical indications. However, most CT scans do not cover head-to-fingertip-to-toe; further research must validate using common CT regions to estimate true whole-body BC, with direct comparison to single lumbar slice. Due to successes of DL, we expect progressive numbers of algorithms to materialize in addition to the seven discussed in this paper. Researchers and clinicians in the field of BC must therefore be aware of pitfalls. High Dice similarity coefficients do not inform the degree to which BC tissues may be under- or overestimated and nor does it inform on algorithm precision. Consensus is needed to define accuracy and precision standards for ground-truth labelling. Creation of a large international, multicentre common CT dataset with BC ground-truth labels from multiple experts could be a robust solution.

Open Appendicectomy under Spinal Anesthesia-A Valuable Alternative during COVID-19.

Introduction Concerns relating to coronavirus disease 2019 (COVID-19) and general anesthesia (GA) prompted our department to consider that open appendicectomy under spinal anesthesia (SA) avoids aerosolization from intubation and laparoscopy. While common in developing nations, it is unusual in the United Kingdom. We present the first United Kingdom case series and discuss its potential role during and after this pandemic. Methods We prospectively studied patients with appendicitis at a British district general hospital who were unsuitable for conservative management and consequently underwent open appendicectomy under SA. We also reviewed patient satisfaction after 30 days. This ran for 5 weeks from March 25th, 2020 until the surgical department reverted to the laparoscopic appendicectomy as the standard of care. Main outcomes were 30-day complication rates and patient satisfaction. Results None of the included seven patients were COVID positive. The majority (four-sevenths) had complicated appendicitis. There were no major adverse (Clavien-Dindo grade III to V) postoperative events. Two patients suffered minor postoperative complications. Two experienced intraoperative pain. Mean operative time was 44 minutes. Median length of stay and return to activity was 1 and 14 days, respectively. Although four stated preference in hindsight for GA, the majority (five-sevenths) were satisfied with the operative experience under SA. Discussion Although contraindications, risk of pain, and specific complications may be limiting, our series demonstrates open appendicectomy under SA to be safe and feasible in the United Kingdom. The technique could be a valuable contingency for COVID-suspected cases and patients with high-risk respiratory disease.

A local experience of non-operative management for an appendicitis cohort during COVID-19.

BACKGROUND: During the first United Kingdom COVID-19 wave, the Royal Colleges of Surgeons initially recommended conservative management with antibiotics instead of surgery for appendicitis. This study compared local outcomes of appendicitis during this period with a pre-COVID-19 cohort. METHODS: An observational study was conducted in a district general hospital. All episodes of appendicitis were prospectively studied from 25th March 2020 until 26th May 2020 and compared with a retrospective pre-COVID cohort from 27th November 2019 until 29th January 2020. Primary outcome was 30-day treatment failure of simple appendicitis for conservatively managed cases during COVID-19 compared to surgically managed cases pre-pandemic. Treatment failure was defined as any unplanned radiological or surgical intervention. RESULTS: Over nine weeks, there were 39 cases of appendicitis during COVID-19 and 50 cases pre-COVID-19. Twenty-six and 50 cases underwent appendicectomy during and pre-COVID-19 respectively. There was no difference in 30-day postoperative complication rates and nor were there any peri-operative COVID-19 infections.Twelve cases of simple appendicitis underwent conservative management during COVID-19 and were compared with 23 operatively managed simple cases pre-pandemic. There was a higher failure rate in the conservative versus operative group (33.3 vs 0% OR = 24.88, 95% CI 1.21 to 512.9, p=0.0095). Length of stay was similar (1.5 vs 2.0 p=0.576). DISCUSSION: Locally, conservative management was more likely to fail than initial appendicectomy. We suggest that surgery should remain first line for appendicitis, with conservative management reserved for those with suspected or proven COVID-19 infection.

A colorectal straight-to-test cancer pathway with general-practitioner-guided triage improves attainment of the 28-day diagnosis target and increases outpatient clinic capacity.

AIM: This study investigates whether a straight-to-test (STT) colorectal cancer pathway improves attainment of the National Health Service (NHS) England 28-day Faster Diagnosis Standard and the effect of the pathway on reducing face-to-face outpatient clinic appointments. Patient satisfaction and the safety of a novel general practitioner (GP) led patient triage system regarding suitability for colonoscopy are also evaluated. METHODS: This is an observational study of all patients managed via an STT colorectal cancer pathway between 1 September 2019 and 19 March 2020. Comparison is made with all patients referred on the suspected colorectal cancer pathway prior to implementation of the STT pathway from 1 January 2019 to 30 July 2019. Patient satisfaction with the STT pathway was assessed with a telephone-based questionnaire. RESULTS: Attainment of the 28-day diagnosis target for all suspected colorectal cancer referrals improved following the establishment of the STT pathway (88% vs. 82%, P < 0.0001). From a potential total of 548 outpatient colorectal clinic appointments for patients on the STT pathway, 504 (92%) were avoided. In those eligible for the STT pathway, GP assessment of patients suitable for colonoscopy agreed with that of the colorectal department in 93% of cases. Of the 50 patients who undertook the satisfaction survey, 86% were satisfied or very satisfied with the pathway. No patient suffered adverse events as a result of their STT investigations. CONCLUSION: An STT pathway for suspected colorectal cancer referrals with novel GP-led patient triage safely streamlines patients through the suspected colorectal cancer diagnostic pathway and significantly reduces requirement for face-to-face outpatient clinic attendance. This is achieved with high patient satisfaction.