Laparoscopic choledocholithotomy for gallbladder and common bile duct stones: Outcomes of primary closure vs T-tube drainage

Abstract

BACKGROUND

Gallbladder stones combined with common bile duct stones are frequently encountered. Laparoscopic choledocholithotomy is an effective treatment, but the optimal bile duct closure method primary closure vs T-tube drainage remains controversial. Primary closure may offer faster recovery and fewer tube-related complications, yet its safety and advantages over T-tube drainage require further validation. This study compared the effectiveness and safety of the two methods.

AIM

To assess the comparative effectiveness and safety of primary ductal closure vs conventional T-tube drainage in patients undergoing laparoscopic choledocholithotomy for gallbladder and common bile duct stones.

METHODS

Clinical data of 102 patients who underwent surgery in the First Department of General Surgery, Peking University Shougang Hospital, from October 2023 to October 2025, were retrospectively analyzed. The primary closure group consisted of 52 patients, and the T-tube drainage group had 50 patients. Factors for comparison were stone number and size, common bile duct diameter, stone clearance rate, liver function variables, operation time, drainage volume, indwelling time, postoperative hospital stay duration, total costs, and postoperative complications. Multivariate logistic regression was used to adjust for baseline differences in common bile duct diameter.

RESULTS

The two groups did not differ significantly in stone characteristics or clearance rates (P > 0.05), although common bile duct diameter distribution differed between groups (P < 0.05). After adjusting for common bile duct diameter and other covariates, primary closure remained associated with significantly shorter operative time, less drainage from the Winslow foramen, faster tube removal, shorter hospital stay, and lower costs (all P < 0.05). Postoperative day 3 liver function parameters (total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase) were significantly lower in the primary closure group, but these differences should be interpreted with caution due to potential confounding by intraoperative factors. While bile leakage did not differ significantly between the two methods, the primary closure group suffered from significantly fewer electrolyte imbalances (P < 0.05); the majority of electrolyte disturbances in the T-tube group were hypokalemia and hyponatremia, possibly related to biliary fluid loss.

CONCLUSION

Primary closure appears to be a safe and effective alternative to T-tube drainage during laparoscopic choledocholithotomy, with potential benefits in recovery and resource utilization. However, these findings are limited by the retrospective, single-center design and residual confounding; prospective studies are needed.

Key Words: Cholecystolithiasis; Choledocholithiasis; Laparoscopic choledocholithotomy; Primary closure; T-tube drainage

Core Tip: Laparoscopic common bile duct exploration (LCBDE) is a standard treatment for cholecystocholedocholithiasis. This retrospective cohort study compares primary closure (PC) vs T-tube drainage (TD) after LCBDE. The findings indicate that PC is a safe and feasible alternative. Compared to TD, PC is associated with faster operative times, reduced abdominal drainage, shorter hospital stays, lower medical costs, and a significantly decreased incidence of postoperative electrolyte disturbances, without increasing the risk of bile leakage or other major complications.

INTRODUCTION

Concomitant gallbladder and bile duct stones are frequent diseases in hepatobiliary surgery. Generally, the major symptom of patients is abdominal pain, but in some cases, there might be accompanying symptoms such as fever, nausea, and vomiting as well. For instance, the rate of cholelithiasis in Chinese adults ranges from 10.0% to 16.2%, and those combined with choledocholithiasis account for a proportion of 18.5%[1-3]. Surgical treatment is very safe and effective[4,5]. Given the continuous development of laparoscopic and choledochoscopic technologies, “dual-scope combined” common bile duct exploration has slowly become one of the main therapeutic methods in clinical practice[6,7]. There are two primary repair methods for the bile duct after laparoscopic common bile duct exploration: T-tube drainage and primary closure[8,9]. Through T-tube drainage, the accumulated bile within the bile duct can be effectively drained and, consequently, pressure inside the biliary system is lowered. However, the accidental removal or blockage of the T-tube may lead to serious complications like bile peritonitis, which severely affects postoperative recovery. When compared with T-tube drainage, primary closure is more in line with the physiological state of the common bile duct, aids the recovery of normal biliary system function, preserves the integrity of the common bile duct, and, simultaneously, avoids complications associated with the T-tube. Currently, choosing one of these two surgical methods is still debated, since there have not been established clinical guidelines. Even more, different centers exhibit variation in the manner they manage the common bile duct intraoperatively[10]. The present study explores the outcomes and safety performance of these two modes of managing the bile duct in the setting of laparoscopic common bile duct exploration, ultimately offering a point of reference in clinical practice.

MATERIALS AND METHODS

General data

A retrospective evaluation was performed on 102 patients who underwent laparoscopic choledocholithotomy for concomitant gallbladder and common bile duct stones at the First Department of General Surgery, Peking University Shougang Hospital, between October 2023 and October 2025. Informed consent was provided by all patients and their families. The cohort included 54 males and 48 females, with a male-to-female ratio of 1.125:1. The age distribution was 28-76 years, with an average age of 52.1 ± 11.7 years. Subjects were stratified into two groups based on the common bile duct management strategy: The primary closure group (n = 52) and a T-tube drainage group (n = 50). All operations were performed laparoscopically, and there was no requirement to convert to open surgery. Baseline characteristics, including age, gender, and body mass index (BMI), were similar between the two groups (P > 0.05, Table 1).

Table 1 Comparison of baseline demographic and clinicopathologic characteristics between the two study cohorts, mean ± SD.

Indicator	Primary closure group (n = 52)	T-tube drainage group (n = 50)	t, χ2 value	P value
Age (years)	52.4 ± 11.3	51.8 ± 12.1	0.268	0.789
Gender (M/F)	28/24	26/24	0.021	0.884
BMI (kg/m2)	23.6 ± 3.2	24.1 ± 3.5	-0.782	0.436
Hypertension (n)	13	11	0.151	0.698
Diabetes (n)	9	10	0.049	0.825

M: Male; F: Female; BMI: Body mass index.

Inclusion and exclusion criteria

Inclusion criteria: (1) Diagnosis of gallbladder stones along with common bile duct stones, confirmed by imaging examinations such as abdominal ultrasound, computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP); (2) The patients had undergone no secondary diagnostic or therapeutic interventions (e.g., endoscopic retrograde cholangiopancreatography) or surgical treatment on the bile duct prior to surgery; and (3) No contraindications for general anesthesia according to the preoperative anesthetic assessment.

Exclusion criteria: (1) Insufficient or incomplete clinical records; (2) Pre-existing coagulation disorders; (3) Clinical presentation of acute obstructive suppurative cholangitis or severe acute pancreatitis prior to the procedure; and (4) Intraoperative choledochoscopy revealing an abnormally narrow common bile duct, distal biliary obstruction of undetermined etiology, or suspected dysfunction of the sphincter of Oddi.

Surgical methods

Both cohorts underwent surgical procedures performed under general anesthesia with pressure-controlled pneumoperitoneum (12 mmHg). Following a three-port laparoscopic entry, Calot’s triangle was exposed through gallbladder retraction. The cystic duct and artery were subsequently separated, sealed with absorbable clips, and cut, followed by antegrade gallbladder resection. In order to identify the common bile duct, the hepatoduodenal ligament was opened. The common bile duct was then identified, and a longitudinal incision of approximately 1.0 cm was made. A choledochoscope was inserted through the subxiphoid operating port to examine the distal common bile duct, common hepatic duct, left and right hepatic ducts, and secondary intrahepatic bile ducts, and then the stones were removed. Upon completion of stone removal, the choledochoscope was employed to check the openness of all portions of the bile duct and the proper functioning of the sphincter of Oddi. The anterior wall incision of the common bile duct was closed with continuous full-thickness 4-0 absorbable sutures in the primary closure group. A drainage tube was placed in the Winslow foramen and brought out through a trocar site after verifying there was no bile leak. In the T-tube drainage group, a T-tube was inserted into the common bile duct through the anterior wall incision. The common bile duct was closed with intermittent 4-0 absorbable sutures. After the T-tube was brought out, 15-20 mL of saline solution was injected through it to check for bile leaks. Likewise, a drainage tube was placed in the Winslow foramen and brought out.

Observation indicators

Surgical conditions: Recorded variables included stone count, maximum stone diameter, stone clearance success rate in a single session (i.e., number of successful cases/total group number × 100%), and the common bile duct diameter, the latter derived from a synthesized assessment of preoperative ultrasonography, CT, and MRCP imaging. Total operative duration was also documented for each procedure.

Postoperative recovery and biochemical assessments: On postoperative day 3, peripheral venous blood was collected to test liver function, hematology, and metabolic status. The recorded metrics included total bilirubin (TBIL), direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and white blood cell count (WBC), alongside sodium (Na⁺) and potassium (K⁺) serum levels. Additionally, postoperative recovery trajectories were monitored by recording total abdominal drainage volume, time to drainage tube removal, length of postoperative hospitalization, and total healthcare expenditures per patient.

Postoperative complications: Included the presence of residual calculi, bile leakage, bleeding, electrolyte imbalances, acute pancreatitis, cholangitis, and long-term biliary strictures or recurrence. Definitions for each indicator were as follows: (1) Residual calculi: All patients underwent outpatient follow-up 1-2 months post-operation with abdominal ultrasound and MRCP. Besides those in the T-tube drainage group who received T-tube cholangiography or choledochoscopies via the sinus tract, finding common bile duct stones at these procedures confirmed the residual calculi; (2) Bile leakage: The concentration of bile in the drainage fluid was threefold superior to that of the upper normal limit of serum bile concentration on postoperative day 3; (3) Bleeding: At any time after surgery, bloody fluid drained from the abdominal drain was ≥ 100 mL/day, with or without signs of hypovolemic shock; (4) Electrolyte imbalances: Serum levels of Na⁺, K⁺, etc., on postoperative day 3 were above or below normal reference values; (5) Acute pancreatitis: Post-surgery, patients suddenly experienced upper abdominal pain, bloating, vomiting, etc. At the same time, serum and urine amylase levels were elevated, and imaging (abdominal ultrasound, CT) revealed exudative changes around the pancreas; (6) Cholangitis: Diagnosed based on clinical symptoms (upper abdominal pain, fever, jaundice) paired with elevated WBC and neutrophilia, with or without radiographic evidence of biliary obstruction or ductal dilation; (7) Biliary stricture: Characterized by postoperative ductal inflammation, mucosal erosion, and subsequent fibroplasia, with CT or MRCP imaging revealing localized narrowing of the common bile duct, potentially accompanied by proximal dilation; and (8) Stone recurrence: Patients were cured and discharged during the perioperative period with no residual stones on follow-up, but during follow-up, they again presented with clinical manifestations such as abdominal pain, bloating, fever, jaundice, laboratory findings of elevated bilirubin and transaminases, and imaging revealing common bile duct stones. Complications during the treatment were detected by postoperative observation and imaging. Clinical efficacy was assessed through complete follow-up, including outpatient visits and telephone calls.

Statistical analysis

Statistical analyses were performed using SPSS 26.0 software. Measurement data following a normal distribution were expressed as mean ± SD, and an independent samples t-test was used to compare the means of two groups. Data not normally distributed were represented by median (25^th percentile, 75^th percentile), and the Wilcoxon rank-sum test was used for group comparisons. Count data were represented by rates (%), and, for group comparisons, the χ² test or Fisher’s exact test was used for categorical variables. To address potential selection bias arising from the significant difference in common bile duct diameter between groups, we performed multivariate logistic regression analysis adjusting for common bile duct diameter (< 8 mm, 8-10 mm, 10-15 mm, > 15 mm), age, sex, BMI, and stone burden (number and maximum diameter). For continuous outcomes (operative time, drainage volume, hospital stay, costs), generalized linear models with an identity link function were used. For binary outcomes (complications), multivariable logistic regression was applied. A P value < 0.05 was considered statistically significant.

RESULTS

Perioperative comparison of hepatobiliary function, inflammatory markers, and serum electrolytes

The preoperative levels of TBIL, DBIL, ALT, AST, ALP, and WBC did not differ significantly between the two groups (P > 0.05). TBIL, DBIL, ALT, AST, and ALP levels decreased on postoperative day 3 in both groups compared to preoperative levels. When compared to the T-tube drainage group, all these parameters in the primary closure group were significantly lower (P < 0.05). However, given the retrospective design and the lack of adjustment for intraoperative factors such as the complexity of bile duct exploration or the duration of choledochoscopy, these differences should be interpreted as hypothesis-generating rather than causal. WBC, Na⁺, and K⁺ levels were not significantly different between the two groups in either the preoperative or postoperative periods (P > 0.05; Table 2). Among electrolyte disturbances, the T-tube drainage group had 5 cases of hypokalemia (K⁺ < 3.5 mmol/L) and 2 cases of hyponatremia (Na⁺ < 135 mmol/L); the single electrolyte disturbance in the primary closure group was mild hypokalemia.

Table 2 Comparative analysis of baseline and postoperative (day 3) biochemical, hematologic, and electrolyte parameters, mean ± SD.

Time point	Indicator	Primary closure group (n = 52)	T-tube drainage group (n = 50)	t value	P value
Preoperative	TBIL (μmol/L)	32.5 ± 15.2	33.1 ± 14.8	-0.202	> 0.05
	DBIL (μmol/L)	18.4 ± 8.1	18.9 ± 7.6	-0.324	> 0.05
	ALT (U/L)	98.5 ± 45.3	101.2 ± 50.1	-0.287	> 0.05
	AST (U/L)	85.7 ± 40.2	88.3 ± 42.5	-0.319	> 0.05
	ALP (U/L)	165.4 ± 55.6	170.2 ± 60.3	-0.418	> 0.05
	WBC (× 1012/L)	7.5 ± 2.1	7.6 ± 2.3	-0.231	> 0.05
	Na+ (mmol/L)	140.5 ± 3.2	140.8 ± 3.5	-0.456	> 0.05
	K+ (mmol/L)	4.1 ± 0.4	4.1 ± 0.5	0.000	> 0.05
Postoperative day 3	TBIL (μmol/L)	19.3 ± 6.7	25.3 ± 5.1	-5.142	< 0.05
	DBIL (μmol/L)	10.5 ± 4.2	14.8 ± 3.9	-5.373	< 0.05
	ALT (U/L)	28.5 ± 8.9	36.8 ± 10.1	-4.437	< 0.05
	AST (U/L)	59.8 ± 15.4	85.5 ± 16.2	-8.203	< 0.05
	ALP (U/L)	139.2 ± 18.1	154.2 ± 17.1	-4.360	< 0.05
	WBC (× 1012/L)	7.8 ± 2.5	7.9 ± 2.6	-0.198	> 0.05
	Na+ (mmol/L)	139.5 ± 3.8	138.2 ± 4.1	1.667	> 0.05
	K+ (mmol/L)	4.0 ± 0.5	3.9 ± 0.6	0.920	> 0.05

TBIL: Total bilirubin; DBIL: Direct bilirubin; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; ALP: Alkaline phosphatase; WBC: White blood cell count; Na⁺: Sodium; K⁺: Potassium.

Comparative analysis of intraoperative parameters and postoperative recovery metrics

There were no statistically significant differences in the number of calculi and the maximum stone diameter between the two groups (P > 0.05). Conversely, the distribution of common bile duct diameters exhibited statistically significant differences (P < 0.05). All surgeries were completed without turning to open surgery, and both groups exhibited a 100% stone clearance success rate was 100% (P > 0.05). Operative time, drainage volume from the Winslow foramen; drainage tube indwelling time, postoperative hospitalization length, and total treatment expenditures varied significantly between the two groups (P < 0.05; Table 3). After multivariate adjustment for common bile duct diameter, age, sex, BMI, and stone burden, primary closure remained independently associated with shorter operative time [β = -23.1 minutes, 95% confidence interval (CI): -31.4 to -14.8, P < 0.001], reduced Winslow foramen drainage (β = -192.4 mL, 95%CI: -242.6 to -142.2, P < 0.001), shorter drain indwelling time (β = -2.4 days, 95%CI: -3.1 to -1.7, P < 0.001), shorter postoperative hospital stay (β = -2.5 days, 95%CI: -3.4 to -1.6, P < 0.001), and lower total costs (β = -4850 Chinese yuan, 95%CI: -6120 to -3580, P < 0.001).

Table 3 Surgical performance and postoperative rehabilitation indicators across the study cohorts, mean ± SD.

Indicator	Primary closure group (n = 52)	T-tube drainage group (n = 50)	t, χ2 value	P value
Stone count (n)	2.4 ± 1.2	2.5 ± 1.3	-0.402	> 0.05
Maximum stone diameter (mm)	8.5 ± 3.2	8.7 ± 3.5	-0.301	> 0.05
CBD diameter distribution (n)			8.247	< 0.05
< 8 mm	5	12
8-10 mm	18	20
10-15 mm	22	14
> 15 mm	7	4
Stone clearance success rate (Y/N, n)	52/0	50/0		> 0.05
Operation time (minute)	85.6 ± 18.4	110.3 ± 22.7	-6.084	< 0.05
Winslow foramen drainage (mL)	156.3 ± 45.2	358.7 ± 92.5	-14.123	< 0.05
Drain tube indwelling time (day)	3.2 ± 1.1	5.8 ± 1.6	-9.634	< 0.05
Postop hospitalization time length (day)	5.6 ± 1.8	8.3 ± 2.4	-6.517	< 0.05
Total treatment cost (Chinese yuan)	18500 ± 3200	23800 ± 4100	-7.343	< 0.05

Y: Yes; N: No; CBD: Common bile duct.

Comparative analysis of postoperative morbidity and adverse events

All 102 patients completed the 1-2 months postoperative imaging follow-up (abdominal ultrasound and MRCP; T-tube cholangiography for the T-tube group), with no loss to follow-up. During the short-term follow-up period (1-2 months postoperatively), no residual calculi, bleeding, acute pancreatitis, acute cholangitis, biliary stricture, or stone recurrence was detected in either group. There were fewer cases of bile leakage in the primary closure group (3.8%, 2/52) compared to the T-tube drainage group (8.0%, 4/50), but that difference did not reach statistical significance (P > 0.05). However, the primary closure group exhibited a significantly lower rate of postoperative electrolyte disturbances (1.9%, 1/52) than the T-tube drainage group (14.0%, 7/50; P < 0.05; Table 4). The significantly higher rate of electrolyte disturbances in the T-tube drainage group (14.0% vs 1.9%, P = 0.045) was primarily driven by hypokalemia and hyponatremia, which may be attributable to loss of bile salts and fluids via the T-tube; however, detailed data on drainage fluid composition and fluid resuscitation were not available.

Table 4 Comparison of postoperative complications between the two groups.

Group	n	Bile leak	Electrolyte disturbance	χ2 value	P value
Primary closure group	52	2	1	0.558	0.455
T-tube drainage group	50	4	7	4.022	0.045

DISCUSSION

The coexistence of gallbladder and common bile duct stones represents a significant burden in modern hepatobiliary surgery[11]. The fundamental therapeutic objectives remain the relief of biliary obstruction, the definitive eradication of the lesion, and the restoration of unobstructed physiological drainage. Laparoscopic choledocholithotomy has emerged as a cornerstone of management, facilitating a comprehensive endoscopic evaluation of the biliary tree. Nowadays, surgeons can precisely identify calculi, their areas of impaction, or strictures while simultaneously assessing the functional integrity of the sphincter of Oddi. This has allowed one-stage radical treatment for both gallbladder and common bile duct stones[12].

At present, T-tube drainage is the conventional method for closing the bile duct after laparoscopic common bile duct exploration. It not only allows a direct visual inspection of the surgical result, but also plays major roles in bile drainage, bile duct support, and biliary decompression. Yet, this method can lead to several potential risks, for example, electrolyte imbalances, accidental T-tube dislodgement, migration, and blockage, which may interfere with the patient’s postoperative recovery[13]. This has made hepatobiliary surgeons consider whether primary closure after choledochotomy is a safe and feasible option. A number of studies[14-16] show that primary closure, when compared with T-tube drainage, is beneficial in improving perioperative measures and enhancing patient recovery. In this study, the primary closure group had significantly better results regarding postoperative ALT, AST, and ALP levels, operative time, postoperative abdominal drainage volume, drainage tube indwelling time, postoperative hospitalization length, and total treatment expenditures than the T-tube drainage group. Although we observed significantly lower postoperative day 3 liver function parameters (TBIL, DBIL, ALT, AST, ALP) in the primary closure group, it is important to note that early postoperative changes in transaminases and bilirubin reflect multiple factors including the timeliness of preoperative obstruction relief, anesthetic effects, and intraoperative liver manipulation, rather than the isolated effect of bile duct closure method. Our study did not adequately capture these intraoperative variables (e.g., duration of choledochoscopy, difficulty of stone extraction, or the degree of papillary edema), which limits the causal interpretation of the liver function differences. These findings can be attributed to several physiological and technical factors. First, primary closure is intrinsically more physiological (i.e., by immediately restoring the anatomical continuity of the common bile duct, bile is directed into the duodenum). A more conservative explanation is that primary closure avoids the external diversion of bile caused by T-tube drainage, thereby maintaining normal bile flow and possibly reducing cholestasisinduced liver enzyme elevation. We acknowledge that direct physiological evidence for the “early restoration of enterohepatic circulation” at postoperative day 3 is lacking. Future studies with serial bile acid measurements are needed to confirm this hypothesis. Consequently, there is a more pronounced decline in transaminases, ultimately indicating a faster resolution of hepatocellular injury. Second, the technique simplifies the operative workflow, not only saving the time required for T-tube placement and leak testing but also eliminating the problem of T-tube positioning during suturing. Finally, primary closure causes the least disruption of the abdominal cavity and, therefore, a lesser degree of inflammatory response. This reduced biological stress correlates with lower levels of postoperative pain and patient anxiety, ultimately fostering a more rapid recovery and significantly reducing medical costs.

In terms of postoperative complications, there were no cases of postoperative bleeding, pancreatitis, or biliary stricture in either group. It was observed that the primary closure group had fewer postoperative electrolyte disturbances as compared to the T-tube drainage group. Among electrolyte disturbances, the T-tube drainage group had 5 cases of hypokalemia (K⁺ < 3.5 mmol/L) and 2 cases of hyponatremia (Na⁺ < 135 mmol/L); the single electrolyte disturbance in the primary closure group was mild hypokalemia. The significantly higher rate of electrolyte disturbances in the T-tube drainage group (14.0% vs 1.9%, P = 0.045) may be attributable to loss of bile salts and fluids via the T-tube; however, detailed data on drainage fluid composition and fluid resuscitation were not available. This finding suggests that closer monitoring of electrolytes and timely supplementation may be beneficial for patients with T-tube drainage. Moreover, the primary closure group was not associated with a higher risk of residual calculi, bile leakage, acute cholangitis, or stone recurrence. Therefore, primary closure may be considered safe and reliable[13]. Integrating these results with clinical experience allows us to develop the hypothesis that patients subjected to prolonged stone extraction or chronic impaction may suffer from significant mechanical irritation of the bile duct, resulting in duodenal papilla edema. This edema potentially compromises the drainage of bile and pancreatic secretions, thereby elevating the risk of postoperative pancreatitis. Consequently, for patients whose stones are difficult to extract due to impaction, preventive use of somatostatin in combination with antispasmodic and choleretic therapies might be done. Residual calculi are mainly caused by errors of the surgeon when manipulating a choledochoscope, as well as the fragments generated during stone removal. Nonetheless, tiny stones from intrahepatic ducts may also be discharged into the common bile duct. In cases of residual stones after the operation, endoscopic retrograde cholangiopancreatography/endoscopic sphincterotomy is a possible therapeutic option. Primary closure is the primary cause of postoperative bile leakage[17-19], which is a serious complication, possibly resulting from increased biliary pressure due to sphincter of Oddi edema or spasm, and also linked to various factors like excessive pulling of the bile duct wall while suturing, having suture spacing too wide, and suture selection being inappropriate. Proper selection of the case is very important, having into consideration that the diameter of the common bile duct should not be excessively narrow or wide[20], with a slight dilation (10-15 mm) being the most suitable. The wall of the bile duct should have no major inflammatory changes and be of moderate thickness. In addition, intraoperative excessive separation of the tissue and blood vessels around the bile duct wall should be avoided. Suturing must be executed with a gentle touch, prioritizing the avoidance of excessive traction or traumatic clamping of the ductal wall. It is recommended to use 4-0 or 5-0 absorbable or barbed sutures for a continuous closure. To ensure a water-tight seal, a standardized needle spacing of 1-2 mm and a tissue bite width of approximately 2 mm should be maintained, typically requiring 3-5 stitches. If bile leakage persists upon intraoperative testing, then supplementary sutures may be placed at the site of the leak until complete biliary stasis is achieved.

In summary, laparoscopic choledocholithotomy is a highly effective surgical modality for the management of concomitant gallbladder and common bile duct calculi. Our findings demonstrate that primary closure provides significant advantages over traditional T-tube drainage, remarkably minimizing surgical trauma, accelerating postoperative recovery, and lowering the rate of complications. However, the observed differences in early postoperative liver function should not be overinterpreted as direct causal effects of the closure method, given the potential for residual confounding, long-term outcomes such as late biliary stricture and stone recurrence require investigation with extended follow-up. At present, primary closure is not a common practice, and its surgical indications are still to be defined, which may be due to a lack of knowledge about the technique and the old habits of traditional treatments. Nonetheless, it is important to highlight that this single-center retrospective study was performed at a single institution and, therefore, presents inherent limitations.

This study is retrospective and single-center, with inherent selection bias. Despite multivariate adjustment, unmeasured confounders (e.g., surgeon experience, intraoperative difficulty of choledochoscopy, degree of papillary edema, precise timing of liver function tests) may have influenced the results. The significant difference in common bile duct diameter at baseline, although statistically adjusted, reflects a real-world clinical preference (narrower ducts more likely to receive T-tube). Propensity score matching would have been preferable but was not feasible due to sample size. Additionally, the follow-up period was relatively short for assessing long-term outcomes such as biliary stricture or stone recurrence. Therefore, our conclusions should be considered preliminary, and multicenter prospective randomized trials are warranted. Future multicenter prospective studies are required to provide higher-level evidence and refine the therapeutic paradigm for biliary stone disease.

CONCLUSION

Primary closure after laparoscopic choledocholithotomy for concomitant gallbladder and common bile duct stones is a safe and effective alternative to conventional T-tube drainage. It offers significant advantages in terms of shorter operative time, reduced abdominal drainage volume, faster drain removal, shorter postoperative hospital stay, and lower total treatment costs, without increasing the risk of bile leakage, residual stones, or other major complications. Moreover, primary closure is associated with fewer postoperative electrolyte disturbances, likely by preserving the enterohepatic circulation of bile salts. However, the observed differences in early postoperative liver function should be interpreted cautiously, as residual confounding may exist. Given the retrospective, single-center nature of this study, the findings are preliminary. Large-scale, multicenter prospective randomized controlled trials are warranted to validate these results and to refine patient selection criteria for primary closure.

ACKNOWLEDGEMENTS

The authors thank the nursing staff of the First Department of General Surgery, Peking University Shougang Hospital, for their assistance in perioperative care. We also thank Professor Jing-Shan Liu for his guidance and support in the design and implementation of this study.