Reframing intraoperative confocal microscopy as a rule‐in strategy for detrusor muscle

Reframing intraoperative confocal microscopy as a rule-in strategy for detrusor muscleWe read with great interest the prospective IB1-LaserComplete study by Connor et al. [1] evaluating fluorescence confocal microscopy (FCM) for immediate assessment of detrusor muscle (DM) during primary transurethral resection of bladder tumour (TURBT).The authors should be commended for conducting a blinded paired-specimen study and transparently reporting less favourable diagnostic performance than earlier unblinded series.Nevertheless, their findings may support a different clinical interpretation.The authors conclude that low sensitivity (42%) and negative predictive value (21%) preclude FCM as a standalone intraoperative decision tool.This interpretation treats FCM primarily as a test for excluding DM. however, in practice, intraoperative sampling is an asymmetric decision: failure to visualise DM need not establish its absence but may simply prompt another base sample.Conversely, visualising DM could provide a 'stop signal', limiting unnecessary deeper resection and its associated perforation risk.In this cohort, all 11 FCM-positive specimens contained DM on histopathology, while none of the four specimens without DM was classified as FCM-positive.Thus, FCM potentially behaved as a rule-in rather than a rule-out test, allowing DM to be confirmed intraoperatively in 11 of 30 patients.