A nomogram may predict conversion of laparoscopic surgery to open surgery for choledocholithiasis.

Approximately 3-18% of gallbladder stone patients have secondary choledocholithiasis. Laparotomy was previously the standard treatment but required large abdominal incisions and caused postoperative infections, pain, and longer hospital stays. Laparoscopic common bile duct exploration (LCBDE) surgery is now favored as it is less invasive and has a lower risk of infection. Those with common bile duct (CBD) stones also have intrahepatic bile duct (IHD) stones. Laparoscopic hepatectomy (LH) may be safe for those with IHD stones.

Yitao Zheng and colleagues, in a recent study published in BMC Surgery, said, We developed a nomogram to predict conversion to open surgery in laparoscopic surgery for choledocholithiasis, which aids surgeons in planning surgery and timely converting to laparotomy during surgery to minimize the risk of harm to the patient.

Laparoscopic surgery effectively treats common bile duct stones, but high surgeon requirements and conversion to laparotomy risk exist. Our study established a nomogram model to predict the conversion of laparoscopic to laparotomy for choledocholithiasis.

A total of 867 choledocholithiasis patients who underwent laparoscopic surgery were randomly divided into a training and a validation group. A logistic regression analysis-based nomogram was constructed, and its predictive performance was evaluated using AUC, calibration curve, and DCA (decision curve analysis).

Key findings from the study are:

• The nomogram included Previous upper abdominal surgery, maximum diameter of stone ≥12 mm, medial wall of the duodenum stone,
• gallbladder wall and CBD wall thickening, stone size/CBD size ≥0.75, and simultaneous laparoscopic hepatectomy.
• The AUC values were 0.813 and 0.804 in the training and validation groups, respectively.
• The calibration curve presented excellent consistency between the nomogram predictions and actual observations.
• DCA presented a positive net benefit for the nomogram.

In our study, 25 out of 41 conversion surgeries for dense abdominal adhesions were due to PUAS. In our nomogram, stones in the medial wall of the duodenum scored higher with 86 points.

The maximum stone diameter was the transverse diameter perpendicular to the CBD wall. A large ratio increases the difficulty of stone removal. Removing IHD stones is more challenging than liver neoplasm due to the risk of liver inflammation, perihepatic adhesions, and anatomical distortion, the author writes.

Reference:

Zheng, Y et al. A nomogram to predict conversion of laparoscopic surgery to laparotomy for Choledocholithiasis. BMC Surg 23, 372 (2023).