Why use it

Accurate operative time prediction allows optimal theatre list planning, reduces cancellations due to list overrun, guides appropriate case allocation to consultants vs. trainees, and helps identify high-complexity cases requiring senior surgeon presence.

About

The CholeS Score is a validated preoperative prediction model developed to estimate the operative duration of elective laparoscopic cholecystectomy. Derived from the UK CholeS prospective study of over 8,000 laparoscopic cholecystectomies, it uses seven readily available preoperative variables to generate an expected operative time. This enables better theatre scheduling, resource allocation, and appropriate trainee supervision decisions.

When to use

Pre-operative planning for elective laparoscopic cholecystectomy
Theatre list scheduling and time allocation
Determining whether a case is appropriate for trainee operating
Identifying high-complexity cholecystectomies (expected time > 90 min)

Formula

Predicted Time (min) = Base constant + weighted sum of preoperative factors Key contributing factors: Male sex: +7 min Previous upper abdominal surgery: +10 min BMI 30–35: +5 min | BMI > 35: +10 min Acute presentation: +9 min Suspected CBD stones: +14 min Thickened gallbladder wall on US: +8 min Pericholecystic fluid on US: +10 min Base time ≈ 36 min for average patient

Pearls & pitfalls

Previous abdominal surgery (especially upper abdominal) is the single most impactful factor increasing operative time.
Male sex, increased BMI, acute presentation, and suspected common bile duct stones all add significant operative time.
The score does not predict conversion to open surgery — separate tools exist for that.
Mean operative time in the CholeS cohort was 46 minutes; high scorers averaged > 75 minutes.
Ultrasound findings (wall thickening, pericholecystic fluid) correlate with difficult dissection and increased operative time.
Computed from a linear regression model — result is a continuous predicted time in minutes.

Next steps

Expected time < 45 min: Low complexity — suitable for trainee operating with indirect supervision. Expected time 45–75 min: Intermediate — direct consultant supervision recommended. Expected time > 75 min: High complexity — consultant should operate or provide direct supervision throughout.

Evidence

Derived from the CholeS UK prospective study (Harrison et al., BJS 2018) of 8,820 patients across 166 hospitals. R² = 0.21 for variance explained. Validated in independent UK and international cohorts.

References

Harrison EM et al. Prediction of adverse outcomes after cholecystectomy: the CholeS score. BJS Open. 2018;2(4):219-228. — link
Ford SJ et al. Operative experience and outcomes following laparoscopic cholecystectomy: the CholeS study. Br J Surg. 2017;104(5):614-622. — link

CholeS Score for Laparoscopic Cholecystectomy Duration

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