Application of Laparoscopic Ultrasound in Cystic Duct Stone Surgery: A Retrospective Experience

Abstract

Objective

To investigate the value of laparoscopic ultrasound (LUS) in the diagnosis of cystic duct stones and formulation of surgical strategies.

Materials and Methods

Clinical data from 41 patients with cystic duct stones were retrospectively analyzed. LUS was used to evaluate stone distribution and assess the surrounding vasculature, thereby preventing residual stones. Additionally, LUS was used to detect concurrent common bile duct (CBD) stones or assess potential stone migration into the CBD.

Results

Thirty-nine patients underwent laparoscopic cholecystectomy (LC), and two patients underwent LC combined with CBD exploration. The mean postoperative hospital stay was 3.95 ± 1.02 days. During a 3-month to 1-year follow-up, no biliary complications occurred.

Conclusion

LUS ensures safe and effective cholecystectomy for cystic duct stones by enabling real-time stone detection and preventing residual or migrated stones.

Keywords

laparoscopic ultrasound - gallstones - cystic duct stones - laparoscope - laparoscopic cholecystectomy - intraoperative diagnosis - surgical strategy

Laparoscopic cholecystectomy (LC) is a well-established standard treatment for gallstones.[1] In clinical practice, calculous cholecystitis with cystic duct stones is frequently encountered. Improper management of these stones may lead to residual stones or migration into the common bile duct (CBD), increasing the risk of postoperative complications.[2] [3]

Addressing cystic duct stones effectively remains a significant challenge for surgeons. We retrospectively analyzed 41 cases where laparoscopic ultrasound (LUS) was utilized during cystic duct stone surgery and achieved favorable outcomes.

General Information

Among the 41 patients in this cohort, 22 were male and 19 were female, with ages ranging from 37 to 60 years (mean age: 42.80 ± 11.35 years) and symptom duration of 3 days to 5 years. Comorbidities included hypertension in one patient, diabetes mellitus in one patient, and chronic hepatitis B in three patients. All patients underwent preoperative hepatobiliary ultrasound, abdominal CT, or magnetic resonance cholangiopancreatography (MRCP), which confirmed cystic duct stones in all patients ([Fig. 1]). Laboratory findings revealed elevated white blood cell counts in three patients, elevated aminotransferase levels in six patients, and mildly elevated bilirubin levels in five patients. Preoperative diagnosis rates: ultrasound: 9/41 (22.0%), CT: 21/41 (51.2%), and MRCP: 11/41 (26.8%).

Fig. 1 Preoperative imaging demonstrating cystic duct stones. (A) Axial CT demonstrating gallstones and cystic duct stones. Yellow arrow: gallstone; red arrow: cystic duct stone. (B) Transabdominal ultrasound depicting a cystic duct stone (red arrow) adjacent to the gallbladder (GB, yellow arrow). (C) MRCP revealing a cystic duct stone (yellow circle: filling defect).

Surgical Methods

Under general anesthesia (laryngeal mask airway or endotracheal intubation), patients were positioned in the reverse Trendelenburg position. A three-port approach was used, with ports placed at the paraumbilical, subxiphoid, and right midclavicular subcostal region. In technically challenging cases, a fourth port was added at the right subcostal midaxillary line ([Fig. 2]). Pneumoperitoneum pressure was maintained at 12 to 14 mmHg.

Fig. 2 Operating room setup demonstrating surgeon positioning and trocar placement.

The cystic triangle was dissected using an electrosurgical hook or ultrasonic dissector. Intraoperative LUS ([Fig. 3]) provided real-time visualization of the cystic duct, CBD, and surrounding vasculature. The cystic duct was isolated and mobilized, followed by ligation of the cystic artery. Cystic duct stones and their locations were confirmed via LUS combined with preoperative imaging.

Fig. 3 Intraoperative photographs showing the surgical process. (A) Intraoperative LUS exploration. Green triangle: Calot's triangle. (B) LUS of Calot's triangle (red circle in the schematic). Yellow arrow: stone in cystic duct; green arrow: common hepatic duct. (C) LUS visualization of cystic duct-CBD confluence (red arrow; red circle in the schematic). (D) Cystic ductotomy for stone extraction. CBD: common bile duct; CHD: common hepatic duct; GB: gallbladder; LUS: laparoscopic ultrasound.

For stone management:

If stones were ≥ 5 mm from the cystic duct–CBD junction:

The gallbladder was retracted to expose the cystic duct, and a clip was applied proximal to the stone to occlude the cystic duct. (Caution: clearly identify the cystic duct–CBD junction during clip application to avoid CBD injury).

If stones were < 5 mm from the junction:

The cystic duct was incised distal to the stone, and stones were removed by “milking” the duct from the junction toward the incision.

After stone removal, LUS was used to re-evaluate the cystic duct stump for residual stones and assess the CBD for migrated stones. The cystic duct stump was then ligated with clips or sutured, and the gallbladder was excised. The abdomen was irrigated, and a drain was placed selectively.

Results

All patients successfully underwent laparoscopic surgery. Thirty-nine patients underwent LC, and two patients were found to have CBD stones by intraoperative LUS, and thus underwent LC combined with CBD exploration. The operative time was 75.00 ± 26.95 minutes, intraoperative blood loss was 10.21 ± 8.21 mL, and the mean postoperative hospital stay was 3.95 ± 1.02 days. No stone-related biliary complications (e.g., residual stones, cholangitis, or biliary obstruction) were observed during the follow-up period (3 months–1 year; [Table 1]).

Table 1 Perioperative clinical data

Parameter	No. (n = 41)
Age (y)	42.80 ± 11.35
Sex (male/female)	22/19
Operating time (min)	75.00 ± 26.95
Intraoperative blood loss (mL)	10.21 ± 8.21
Postoperative stay (d)	3.95 ± 1.02
Leukocyte (×109/L)	6.74 ± 3.15
Total bilirubin (μmol/L)	16.05 ± 15.62
ALT (U/L)	47.47 ± 69.34
Follow-up time	3 mo–1 y
Bile leakage (%)	0
Biliary stricture (%)	0

Discussion

Gallstones are often associated with cystic duct stones. If incarceration occurs, gallbladder tissue edema exacerbates, which increases the difficulty of surgery.[4] [5] When dissecting the Calot's triangle, if the tissue edema is severe and anatomical dissection is difficult, intraoperative bleeding may interfere with the operation. In the absence of clear dissection, ligation of the cystic duct may lead to residual cystic duct stones, recurrent infection due to the presence of a stone, or migration of the stone into the CBD.[6] [7] [8]

In clinical practice, some surgeons use separation forceps to squeeze the cystic duct from the distal end of the cystic duct toward the proximal end in an attempt to ” milk” the stone back into the gallbladder.[9] [10]

LUS combines ultrasound technology with laparoscopic instruments during the process of laparoscopic surgery. The probe adheres well to the organ surfaces for scanning and provides clearer and more accurate images.[11]

The lack of tactile sensation during laparoscopy can be compensated for to a certain extent by placing the probe at the confluence of the cystic duct and the CBD to identify the structures of the cystic duct, CBD, and common hepatic duct.[12] [13]

In the case of unclear anatomical structure due to edema, multiple scans can be performed during the operation as needed to fully visualize the confluence of the biliary ducts. If the distance between the cystic duct stones and the confluence with the CBD is suitable for applying a clip, the cystic duct can be occluded. If the distance is too close and there is no suitable position for applying a clip, the cystic duct can be opened to remove the stones, and the cut end of the cystic duct sutured. When the cystic duct stump is in close proximity to the CBD, we recommend using 5-0 polydioxanone suture to prevent strictures.

LUS can detect concurrent CBD stones or migrated stones intraoperatively. Intraoperative choledochoscopy for stone removal or postoperative endoscopic stone removal can be performed promptly. For the sutured bile duct, LUS can be used to assess for biliary strictures.

In this study, 41 cases of cystic duct stones were reviewed. Cholecystectomy under LUS guidance was successfully completed, and the cystic duct stones were properly managed. Among them, two patients had no CBD stones detected before surgery, but intraoperative LUS revealed CBD stones. Prompt choledochotomy and choledochoscopic exploration were performed to remove the stones, avoiding the omission of CBD stones. However, LUS also has its limitations. The probe is usually small in size, making it difficult to comprehensively scan a large area of tissue at one time. Only through accumulating substantial experience in both laparoscopic surgical procedures and ultrasonic examination techniques can one truly master LUS technology.

In summary, the application of LUS in surgery ensures the safety and effectiveness of cholecystectomy for cystic duct stones, enables timely detection of stones, and prevents stone retention.

Conflict of Interest

None declared.

Acknowledgments

The authors kindly thank the patients participating in this research for their trust in us.

Authors' Contributions

R.C. conceived the study, acquired the data, and prepared the manuscript. S.T., S.Q., and Z.L. analyzed and interpreted the data. X.S., Y.C., and Y.L. reviewed the manuscript. All authors read and approved the final manuscript.

Ethical Approval

The study was approved by the Ethics Committee of Dongguan Tungwah Hospital. All methods were performed in accordance with the Declaration of Helsinki.

Consent for Publication

Written informed consent for publication of clinical details and imaging data was obtained from all participants or their legal guardians.

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Publication History

Received: 09 August 2025

Accepted: 22 October 2025

Article published online:
06 November 2025