Faecal Immunochemical Testing to Detect Colorectal Cancer in Symptomatic Patients: A Diagnostic Accuracy Study.

(1) Background: NHS England recommended faecal immunochemical testing (FIT) for symptomatic patients in June 2020 to rationalise limited diagnostic services during COVID-19. (2) Aim: to investigate the diagnostic performance of FIT, analysing the proportion of FIT-negative colorectal cancers (CRC) missed in symptomatic patients and how this risk could be mitigated. (3) Design and Setting: a retrospective study of biochemistry and cancer databases involving patients referred from primary healthcare with suspected CRC to a single secondary care trust in North East London. (4) Methods: a retrospective cohort diagnostic accuracy study was undertaken to determine the performance of FIT for detecting CRC at 10 µgHb/g. (5) Results: between January and December 2020, 7653 patients provided a stool sample for FIT analysis; 1679 (22%) samples were excluded due to inadequate or incorrect specimens; 48% of suspected CRC referrals completed FIT before evaluation; 86 FIT tested patients were diagnosed with histologically proven CRC. At 10 µgHb/g, FIT performance was comparable with the existing literature with a sensitivity of 0.8140 (95% CI 0.7189-0.8821), a specificity of 0.7704 (95% CI 0.7595-0.7809), a positive predictive value (PPV) of 0.04923 (95% CI 0.03915-0.06174), a negative predictive value (NPV) of 0.9965 (95% CI 0.9943-0.9978), and a likelihood ratio (LR) of 3.545; 16 patients with CRC had an FIT of ≤10 µgHb/g (18.6% 95% CI 11.0-28.4%). (6) Conclusions: this study raises concerns about compliance with FIT testing and the incidence of FIT-negative CRC at the NICE recommended threshold and how this risk can be mitigated without colonic imaging. Whilst FIT may have facilitated prioritisation during COVID-19, we must be cautious about using FIT alone to determine which patients are referred to secondary care or receive further investigation.

Hallux Valgus Interphalangeus Measurement: Comparison of the 2 Radiographic Methods.

BACKGROUND: To determine the reliability of Delta PP (difference in medial and lateral proximal phalanx wall length) compared with HIA (hallux interphalangeal angle) in the assessment of HVI (hallux valgus interphalangeus) in both preoperative and postoperative radiographs. METHODS: This was a retrospective observational study of 186 feet with hallux valgus. The number of cases required to adequately power the study was 128. Preoperative and postoperative hallux alignment were evaluated by 2 different radiological parameters, Delta PP and HIA. Interobserver variability was assessed independently by 2 authors and compared using a intraclass correlation coefficient. RESULTS: The intraclass correlation coefficient was more than 0.8 for all parameters, thus both HIA and Delta PP measurement provide reliable and reproducible data. Mean HIA significantly increased following surgical correction of hallux valgus. In comparison, the mean Delta PP decreased after correction. This postoperative increase in HIA indicates that preoperative HIA underestimates the magnitude of HVI and therefore is an inaccurate tool for measuring HVI's contribution to the TVDH (total valgus deformity of the hallux) and to preoperative planning. However, the Delta PP was a greater determinant of the phalanx deformity's contribution to the TVDH. CONCLUSION: The outcome of our study shows that both HIA and Delta PP are reproducible when assessing the HVI deformity; however, Delta PP quantifies the amount of correction obtained more precisely. The additional benefit of measuring the Delta PP is that it allows for accurate planning in determining the dimensions of the medial-based wedge of the Akin osteotomy that needs to be resected. LEVELS OF EVIDENCE: Level 4.

Surgical iridotomy in aphakic eyes and eyes with anterior chamber intraocular lenses.

UNLABELLED: We describe a simple technique to create a peripheral surgical iridotomy using a microvitreoretinal blade. The blade passes perpendicular to the iris dilator fibers to create a permanent opening. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.