An observational study in Cholelithiasis, sponsored by University Hospital of Split. Recruiting at 1 site in Croatia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by University Hospital of Split · Observational
This prospective observational study will examine how electrosurgical activation patterns during elective laparoscopic cholecystectomy are associated with surgeon experience and intraoperative difficulty. Adult patients scheduled for elective laparoscopic cholecystectomy at University Hospital of Split will receive standard clinical care; the study does not assign an intervention or change the surgical technique. A fixed camera will record only the laparoscopic monitor, and a directional microphone will record the audible signals of the electrosurgical generator. The study includes a cross-sectional comparison among surgeons with different cumulative experience and a longitudinal assessment of developing surgeons as they gain additional experience. Activation patterns will be analyzed separately during dissection of the hepatocystic triangle and separation of the gallbladder from the liver bed. Intraoperative difficulty will be graded from the initial operative video using the Parkland Grading Scale by two independent assessors, with adjudication when needed.
This is a single-center, two-stage prospective observational cohort study conducted during elective laparoscopic cholecystectomy. Eligible cases will be included consecutively within predefined surgeon cohorts. Clinical care, case allocation, supervision, operative technique, and decisions regarding conversion or surgeon takeover will not be altered by the study.
Stage 1 is a cross-sectional comparison of 48 evaluable operations, with six operations performed by each of eight surgeons who have different levels of cumulative laparoscopic cholecystectomy experience. Stage 2 is a longitudinal assessment comprising 100 operations performed by four developing surgeons followed through 25 consecutive evaluable operations each, 12 operations performed by two new beginner surgeons, and six operations performed by an experienced reference surgeon. The first six operations of each longitudinally followed surgeon are also included in Stage 1. The umbrella study therefore targets at least 142 unique evaluable operations and anticipates enrollment of 165 patients to allow for technical losses and exclusions.
A Xiaomi Redmi Note 14 Pro+ 5G camera will be fixed outside the sterile field and directed only at the laparoscopic monitor. A BOYA BY-MM1 AI USB-C directional microphone will be positioned toward the loudspeaker of the Valleylab Force FX-C electrosurgical generator. Standard generator settings are Fulgurate coagulation at 65 W, Pure Cut at 35 W, and audible volume at 75%. Any deviation from the standardized equipment or settings will be recorded.
After surgery, investigators will identify two predefined operative segments from the video. Segment A begins with the first electrosurgical activation on tissue in the hepatocystic triangle after exposure has been achieved and ends with the first clip application to a cystic structure. Segment B begins with the first electrosurgical activation used to separate the gallbladder from the liver and ends with complete gallbladder separation or the beginning of final liver-bed hemostasis. WAV audio will be exported for each segment. A locked local Python/Streamlit application will identify individual electrosurgical activations and derive activation counts, durations, intervals, rates, and total activation time.
The initial appearance of the gallbladder will be graded on the Parkland Grading Scale (grades 1 to 5) before substantial dissection. Two assessors who are blinded to the audio-analysis results will grade each case independently. Disagreement will be adjudicated by an additional qualified investigator who did not perform that operation.
The main analyses will use mixed-effects models to assess associations of cumulative operative experience, Parkland grade, operative segment, and the experience-by-Parkland interaction with electrosurgical activation patterns. Longitudinal models will account for repeated operations nested within surgeon. Effect estimates will be reported with 95% confidence intervals.
291 studies on the registry are indexed under Cholelithiasis; 49 are open to participants now.
This study's planned enrollment of 165 is below the median of 200 across 84 observational studies indexed under Cholelithiasis.
Browse Cholelithiasis studies →University Hospital of Split is the lead sponsor of 31 studies on the registry; 9 are open to participants now.
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Adult patients undergoing elective laparoscopic cholecystectomy in the regular operating program at the Department of Surgery, Division of Abdominal Surgery, University Hospital of Split. Consecutive eligible cases will be sampled within predefined surgeon cohorts. Male sex, age over 65 years, and thickened gallbladder wall are not exclusion criteria and will be recorded as potential covariates. An unexpectedly pronounced inflammatory or acute-like intraoperative finding does not itself exclude an otherwise elective case; difficulty will be captured using the Parkland grade.
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Exclusion Criteria:
Adult patients undergoing elective laparoscopic cholecystectomy under standard clinical care. Consecutive eligible cases will be enrolled within predefined surgeon cohorts. The exposures of interest are the operating surgeon's cumulative laparoscopic cholecystectomy experience and the Parkland grade of intraoperative difficulty. Electrosurgical activation patterns will be derived from synchronized recordings of the laparoscopic monitor and generator audio.
Procedure: Elective laparoscopic cholecystectomy
Standard-of-care elective laparoscopic cholecystectomy. The study does not assign or modify the surgical procedure, operative technique, supervision, or clinical decisions. Investigators will observe electrosurgical activation patterns during two predefined operative segments using synchronized recording of the laparoscopic monitor and electrosurgical generator audio.
Median Duration of Coagulation-Mode Electrosurgical Activations During Segment A
For each operation, the median duration in seconds of individual, clearly separated coagulation-mode activations detected by the locked audio-analysis algorithm during hepatocystic triangle dissection (Segment A). Segment A must contain at least three coagulation-mode activations. The operation is the unit of analysis.
Time frame: During Segment A of the index laparoscopic cholecystectomy
Longitudinal Change in Median Coagulation Activation Duration During Segment A
Change in the operation-level median duration of individual coagulation-mode activations during Segment A for the four longitudinally followed developing surgeons, estimated per 10 additional evaluable laparoscopic cholecystectomies. The effect will be reported as absolute and percentage change with a 95% confidence interval, adjusted for Parkland grade.
Time frame: From the first through the 25th evaluable operation for each longitudinally followed surgeon, up to 31 December 2028
Number of Coagulation-Mode Activations per Minute by Operative Segment
For each operation, the number of detected coagulation-mode activations divided by segment duration in minutes, calculated separately for Segment A and Segment B.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Total Coagulation Activation Time per Minute by Operative Segment
For each operation, the summed duration in seconds of all coagulation-mode activations divided by segment duration in minutes, calculated separately for Segment A and Segment B.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Variability of Coagulation Activation Duration by Operative Segment
For each operation, variability in the duration of individual coagulation-mode activations will be summarized using the interquartile range and median absolute deviation, separately for Segment A and Segment B.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Proportion of Coagulation Activations Longer Than 2 Seconds by Operative Segment
For each operation, the number of coagulation-mode activations lasting more than 2 seconds divided by the total number of coagulation-mode activations, expressed as a percentage and calculated separately for Segment A and Segment B.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Median Inter-Activation Interval by Operative Segment
For each operation, the median time in seconds from the end of one coagulation-mode activation to the start of the next coagulation-mode activation, calculated separately for Segment A and Segment B.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Duration of Each Operative Segment
Elapsed time in seconds from the predefined start to the predefined end of Segment A and Segment B, calculated separately for each segment.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Number of Cutting-Mode Electrosurgical Activations by Operative Segment
For each operation, the number of detected cutting-mode electrosurgical activations, reported descriptively and calculated separately for Segment A and Segment B.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Median Duration of Cutting-Mode Electrosurgical Activations by Operative Segment
For each operation, the median duration in seconds of individual cutting-mode electrosurgical activations, reported descriptively and calculated separately for Segment A and Segment B.
Time frame: During Segments A and B of the index laparoscopic cholecystectomy
Longitudinal Change in Coagulation Activation Rate
Change in the number of coagulation-mode activations per minute among the four longitudinally followed developing surgeons, estimated per 10 additional evaluable laparoscopic cholecystectomies and evaluated by operative segment.
Time frame: From the first through the 25th evaluable operation for each longitudinally followed surgeon, up to 31 December 2028
Longitudinal Change in Total Coagulation Activation Time per Minute
Change in the total coagulation-mode activation time in seconds per minute among the four longitudinally followed developing surgeons, estimated per 10 additional evaluable laparoscopic cholecystectomies and evaluated by operative segment.
Time frame: From the first through the 25th evaluable operation for each longitudinally followed surgeon, up to 31 December 2028
Longitudinal Change in Variability of Coagulation Activation Duration
Change in the interquartile range and median absolute deviation of coagulation-mode activation duration among the four longitudinally followed developing surgeons, estimated across the sequence of evaluable operations and evaluated by operative segment.
Time frame: From the first through the 25th evaluable operation for each longitudinally followed surgeon, up to 31 December 2028
Longitudinal Change in the Proportion of Coagulation Activations Longer Than 2 Seconds
Change in the percentage of coagulation-mode activations lasting more than 2 seconds among the four longitudinally followed developing surgeons, estimated across the sequence of evaluable operations and evaluated by operative segment.
Time frame: From the first through the 25th evaluable operation for each longitudinally followed surgeon, up to 31 December 2028
Longitudinal Change in Operative Segment Duration
Change in the duration in seconds of Segment A and Segment B among the four longitudinally followed developing surgeons, estimated across the sequence of evaluable laparoscopic cholecystectomies.
Time frame: From the first through the 25th evaluable operation for each longitudinally followed surgeon, up to 31 December 2028
Plan to share: Undecided
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University Hospital of Split