TIME TO ACHIEVEMENT OF THE CRITICAL VIEW OF SAFETY AS AN OBJECTIVE INTRAOPERATIVE MARKER OF DIFFICULT LAPAROSCOPIC CHOLECYSTECTOMY: A PROSPECTIVE ANALYTICAL STUDY

Abstract

Objective: To determine the mean time to achievement of the critical view of safety (CVS) and assess its ability to distinguish difficult from non-difficult laparoscopic cholecystectomy. Study Design: Prospective analytical cross-sectional comparative study. Settings: Department of Surgery, Jinnah Postgraduate Medical Centre, Karachi. Period: Five months from December 2025 to April 2026. Material & Methods: Sixty-four adults undergoing elective or emergency laparoscopic cholecystectomy were enrolled by purposive sampling. Modified Nassar grades I-II were classified as non-difficult and grades III-V as difficult. Time from commencement of hepatocystic-triangle dissection to confirmation of all three CVS criteria was recorded. Welch’s t-test was primary; categorical, correlation, censored time-to-event, and receiver operating characteristic (ROC) analyses were complementary. Results: Twenty-five (39.1%) procedures were difficult. CVS was achieved in 38/39 (97.4%) non-difficult and 20/25 (80.0%) difficult procedures (p=0.030). Mean time to CVS was 16.57±5.66 versus 33.55±10.59 minutes; mean difference 16.98 minutes (95% CI 11.75-22.21; p<0.001). Time correlated with Nassar grade (rho=0.820) and total operative time (r=0.918), both p<0.001. Exploratory ROC area was 0.935 (95% CI 0.849-1.000); a ≥25.75-minute threshold yielded 90.0% sensitivity and 97.4% specificity. Conclusion: Time to CVS was substantially longer in difficult laparoscopic cholecystectomy and showed strong discriminatory performance. A prolonged interval may provide an objective intraoperative prompt for escalation or a bailout strategy, but the proposed threshold requires prospective external validation.