Laparoscopic Transcystic Ultra-fine Choledochoscopy for Cholecystolithiasis with Small-diameter Choledocholithiasis

Cholecystolithiasis is a highly prevalent condition worldwide, and approximately 10-20% of these patients present with concomitant choledocholithiasis¹. Stones within the common bile duct can cause biliary obstruction, leading to clinical symptoms such as abdominal pain, jaundice, and fever. If left untreated, it may progress to severe complications, including acute cholangitis, pancreatitis, and even sepsis, posing a significant threat to patient health^2,3.

The surgical management of choledocholithiasis has evolved considerably. Traditional open common bile duct exploration (OCBDE), while effective, is associated with considerable trauma, a prolonged recovery period, and higher morbidity rates⁴. The advent of minimally invasive techniques established two predominant strategies. The first is the sequential approach utilizing Endoscopic Retrograde Cholangiopancreatography (ERCP) combined with Endoscopic Sphincterotomy (EST) followed by Laparoscopic Cholecystectomy (LC). Although minimally invasive, ERCP/EST inherently compromises the integrity of the sphincter of Oddi, leading to potential long-term risks such as duodenobiliary reflux, recurrent cholangitis, and stone recurrence⁵. The second strategy is the single-stage procedure known as Laparoscopic Common Bile Duct Exploration (LCBDE), which was first reported in 1991⁶. LCBDE allows for the definitive management of both gallbladder and bile duct stones in a single setting while preserving the sphincter of Oddi. Current studies have demonstrated that LCBDE is a safe and beneficial approach for patients, offering advantages in reduced hospital stay and overall costs⁷.

Conventional LCBDE is typically performed via a direct choledochotomy. This method is primarily recommended for patients with a dilated common bile duct (typically > 0.8 cm) to mitigate the risk of postoperative bile leakage and stricture formation at the suture site. This requirement presents a significant clinical challenge in managing patients with small-diameter choledocholithiasis (CBD ≤ 0.8 cm). In contrast, for patients with small-diameter choledocholithiasis (common bile duct ≤ 0.8 cm), the transcystic approach utilizing an ultra-fine choledochoscope offers a less invasive alternative. This technique avoids a formal choledochotomy, thereby potentially reducing the risks of bile duct injury, leakage, and long-term stenosis associated with both T-tube placement and primary suture in nondilated ducts⁸.

After stone extraction via LCBDE, the optimal method for biliary duct closure remains a subject of discussion. The traditional approach involves T-tube placement, which decompresses the biliary system and provides an access route for postoperative management of potential residual stones. However, T-tubes are associated with several drawbacks, including patient discomfort, fluid and electrolyte loss, prolonged hospitalization, and risks of displacement or leakage⁹. Primary suture of the duct has emerged as an alternative, potentially avoiding T-tube-related morbidity. The effectiveness and safety of primary suture have been recognized, particularly in selected cases with favorable duct conditions¹⁰. However, in the context of small-diameter common bile ducts, primary suture raises heightened concerns about iatrogenic stenosis.

In this context, the combination of the laparoscopic transcystic approach (avoiding choledochotomy) with ultra-fine choledochoscopy presents a promising solution for small-diameter choledocholithiasis. Nevertheless, the comparative outcomes of primary suture versus T-tube placement following this specific technique are not well-established. Therefore, we present a technical protocol for laparoscopic transcystic ultra-fine choledochoscopy and retrospectively validate its feasibility and safety for treating patients with cholecystolithiasis and small-diameter choledocholithiasis. This approach is particularly suitable when the cystic duct is accessible and the common bile duct is small (≤0.8 cm), but it is contraindicated in cases of severe bile duct wall edema, poor distal patency, or complex stone impaction. Surgeons should possess substantial laparoscopic experience to overcome the associated learning curve.

The protocol was conducted in accordance with the Declaration of Helsinki, and it was approved by the Affiliated Xuzhou Municipal Hospital of Xuzhou Medical University Ethics Committee. The following steps detail the laparoscopic transcystic ultra-fine choledochoscopy for the management of cholecystolithiasis with small-diameter choledocholithiasis (common bile duct diameter ≤ 0.8 cm).

NOTE: We retrospectively analyzed 58 patients with cholecystolithiasis and Small-Diameter choledocholithiasis (common bile duct diameter ≤ 0.8 cm) hospitalized at the Hepatopancreatobiliary Surgery Department of Xuzhou First People's Hospital from June 2020 to December 2022 to validate the technical protocol. All patients presented varying degrees of jaundice and abnormal liver function. Among them, 35 (60.34%) were male, while 23 (39.66%) were female, with patient ages ranging from 21 to 84 years and a mean age of 37.88 ± 11.35 years. For the purpose of retrospective comparison, patients were categorized into two groups based on the closure method: the primary suture group (28 cases ) and the T-tube placement group (30 cases). In addition, 40 patients (68.97%) underwent scheduled surgery, 18 patients (31.03%) underwent emergency surgery, and 12 patients (20.69%) were treated with concurrent biliary pancreatitis surgery.

1. Inclusion criteria and exclusion criteria

1. The inclusion criteria are as follows: (1) Patients diagnosed with cholecystolithiasis combined with Small-Diameter choledocholithiasis (common bile duct diameter ≤ 0.8 cm) through Computed Tomography (CT), ultrasound, or magnetic resonance cholangiopancreatography (MRCP); (2) Patients without abnormalities at biliary-pancreatic junctions and papillary stenosis; (3) Patients without severe cardiopulmonary insufficiency, coagulation disorders, poor liver and kidney functions, or other surgical contraindications ¹¹; (4) Patients without severe edema on bile duct walls and tumorous lesions in bile ducts; (5) Patients with unobstructed common bile ducts; (6) Patients who have signed the informed consent form and are willing to cooperate in examinations and treatments and whose clinical data were complete.
2. Exclusion criteria: (1) Abdominal surgery and/or surgery for cholecystolithiasis and/or choledocholithiasis; (2) Patients who have taken anti-inflammatory and choleretic Chinese patent medicines or antibiotics within the recent two weeks; (3) Patients with autoimmune complications or malignant tumors; (4) Patients who have voluntarily withdrawn from other clinical research or experiments during the same period; (5) Pregnant or lactating female patients.

2. Patient preparation and port placement

1. Induce general anesthesia. Place the patient in a supine position.
2. Sterilize and drape the abdominal surgical field.
3. Establish pneumoperitoneum: Make a 10 mm vertical incision at the sub-umbilical site (Port A). Insert a Veress needle and insufflate carbon dioxide (CO₂) to establish pneumoperitoneum. Checkpoint: Maintain and confirm stable intra-abdominal pressure between 1.6-2.4 kPa.
4. Insert trocars in the following sequence and specifications:
   1. Port A (Observation Port): 10 mm trocar at the sub-umbilical site for the 4K laparoscope.
   2. Port B (Main Operative Port): 10 mm trocar located 3-4 cm below the xiphoid process in the midline.
   3. Port C (First Auxiliary Port): 5 mm trocar below the right costal margin along the mid-clavicular line.
   4. Port D (Second Auxiliary Port): 5 mm trocar below the right costal margin along the right anterior axillary line.
5. Reposition the patient to a steep head-elevated, feet-lowered (reverse Trendelenburg) position with a left lateral tilt.

3. Gallbladder and cystic duct dissection

1. Use dissecting forceps introduced through Port C to retract the gallbladder fundus cephalad and laterally, exposing Calot's triangle.
2. Carefully dissect and clear fibrous tissue and fat from Calot's triangle using a combination of blunt dissection and electrocautery.
   1. Electrocautery parameters: Set to coagulation mode, power: 25-30 W.
3. Identify the cystic artery, doubly clip it with titanium clips, and transect between the clips.
4. Partially dissect the gallbladder from the liver bed at the neck to achieve adequate mobilization.
5. Checkpoint: Achieve the "critical view of safety" - the cystic duct (CD) and common bile duct (CBD) are the only two structures entering the gallbladder, with no residual tissue in Calot's triangle.
6. Apply a clip to the CD at its junction with the gallbladder infundibulum to prevent stone migration. Do not transect the CD.

4. Transcystic access and choledochoscopy

1. Make a longitudinal incision (approximately 3-5 mm in length) in the antero-superior aspect of the CD, close to its junction with the CBD.
2. Transcystic access and scope insertion
   1. Decision point -- handling difficult cystic duct access: If the CD is narrow or tortuous, preventing scope passage, follow the following steps-
      1. Step A (Dilation): Gently dilate the CD using graduated bougie dilators or a balloon catheter under direct vision.
      2. Step B (Cystic Duct Extension): If dilation is unsuccessful, carefully extend the longitudinal incision on the cystic duct itself proximally (in 1-2 mm increments) towards the CD-CBD junction. This maneuver is an extension of the cystic ductotomy and does not constitute a formal choledochotomy on the common bile duct wall. The goal is to create a sufficient aperture at the cystic duct origin for scope passage while preserving the integrity of the CBD.
      3. Step C (Conversion): If transcystic access remains impossible after maximal safe effort (e.g., due to severe inflammation or anatomical anomaly), convert to a formal laparoscopic choledochotomy (a direct incision on the anterior wall of the CBD). This constitutes a significant protocol deviation. In such cases, due to the increased risk of bile leakage and stricture in a small-diameter CBD, T-tube placement is strongly recommended and was consistently performed in our series.
3. Systematically explore the entire biliary tree: first the proximal hepatic ducts, then the distal CBD traversing the papilla into the duodenal lumen.
   NOTE: Confirm complete stone clearance, patency of the distal CBD, and observe normal, rhythmic contractions of the duodenal papilla.

5. Stone extraction and lithotripsy

1. Under direct choledochoscopic vision, introduce a stone basket through the working channel, engage the stones, and retrieve them.
2. Decision point: For stones too large (> 8 mm), too hard, or impacted for safe basket extraction: Employ holmium laser lithotripsy.
   1. Laser parameters: Use a 200 µm or 365 µm laser fiber. Set energy to 0.8-1.2 J/pulse and frequency to 8-15 Hz in pulsed mode. All operating room staff must wear appropriate protective laser eyewear. The surgeon must ensure the laser fiber tip is visible and in direct contact with the stone before firing to prevent accidental injury to the bile duct wall. Avoid firing near metal clips. Fragment stones into particles small enough (<3 mm) to be flushed out or easily basketed.
3. After lithotripsy, vigorously irrigate and flush the CBD with a copious amount of saline solution through the choledochoscope channel to clear all stone fragments.
4. Checkpoint: Perform a final thorough choledochoscopic inspection of the entire CBD, from the intrahepatic ducts to the duodenum, to confirm complete stone clearance. Re-basket any residual fragments.

6. Hemostasis

1. If minor bleeding is observed from the bile duct wall or the CD incision, use mild electro-coagulation via the choledochoscope probe.
   1. Electrocautery parameters: Use a soft coagulation mode at low power (10-15 W).
      NOTE: Use brief, targeted bursts. Avoid direct contact with metal clips and prolonged application to prevent thermal injury or stenosis of the duct.
2. Checkpoint: Achieve complete hemostasis at the CD incision site and within the CBD lumen before proceeding to closure.

7. Bile duct closure

1. The closure method (Primary Suture vs. T-tube) is determined intraoperatively based on assessment of duct wall condition (inflammation, edema), certainty of stone clearance, and distal patency.
   1. Option A: Primary Suture
      1. If conditions are favorable (minimal inflammation, clear ducts, good patency), close the CD incision with primary suture.
      2. Suture parameters: Use 4-0 or 5-0 absorbable monofilament suture on a tapered needle.
      3. Technique specification: Use a continuous or interrupted suture pattern. Take suture bites approximately 1 mm from the incision edge and space stitches 1-1.5 mm apart. Ensure a water-tight closure without causing narrowing or tension on the duct.
      4. Checkpoint / Leak Test: After closure, perform an intraoperative leak test. Instill saline into the CBD via a ureteral catheter passed through the CD (before final closure stitch) or by occluding the CBD distal to the incision and gently compressing the gallbladder/liver, while observing the suture line laparoscopically for any leakage. If a leak is detected, reinforce with additional sutures.
   2. Option B: T-tube placement
      1. If there is significant inflammation, edema, uncertainty regarding complete stone clearance, or difficult dissection, place a T-tube.
      2. Insert a 14-16 Fr T-tube into the CBD through the CD incision. Shorten the limbs appropriately.
      3. Suture the CD incision around the T-tube limb using 4-0 absorbable sutures to ensure a secure fit and prevent dislodgement or peri-tube bile leak.

8. Completion of cholecystectomy and drain placement

1. Complete the dissection and separation of the gallbladder from the liver bed using electrocautery or ultrasonic shears.
2. Place the resected gallbladder into a specimen retrieval bag and extract it through the subxiphoid Port B.
3. Thoroughly irrigate the abdominal cavity, particularly the subhepatic space and foramen of Winslow, with warm saline solution.
4. Checkpoint: Perform a final laparoscopic survey to confirm absolute hemostasis and the absence of bile leakage from the liver bed or the suture line.
5. Place a closed-suction abdominal drain.
   1. Drain parameters: Position the tip of the drain posterior to the hepatoduodenal ligament, in the foramen of Winslow. Route the tube out through the right anterior axillary port site (Port D).
6. Under direct vision, carefully release the pneumoperitoneum.
7. Close the fascial layer of all 10 mm or larger trocar sites (Ports A and B) with absorbable suture. Approximate the skin incisions for all ports.

9. Postoperative care

1. Drain removal criteria: Remove the abdominal drain when the daily serosanguinous output is less than 50 mL for 24 consecutive hours and is non-bilious, typically by postoperative day 2-4.
2. For patients with a T-tube: The T-tube is connected to a gravity drainage bag. Plan a T-tube cholangiogram 4-6 weeks postoperatively. If no residual stones or leaks are seen, and the patient is well, the T-tube can be removed after a trial of clamping.

10. Observation indexes

1. Baseline Data:Compare patient demographics and history, including age, gender, body mass index, smoking status, alcohol consumption history, past history of upper abdominal surgery, and the prevalence of hypertension, diabetes, and cerebrovascular diseases. Also, compare clinical metrics such as total bilirubin (TBil), aspartate transaminase (AST), gamma-glutamyl transpeptidase (GGT), alanine aminotransferase (ALT), white blood cell count (WBC), albumin, common bile duct diameter, and largest stone diameter.
2. Perioperative Data: Compare operative outcomes, including operative duration, intraoperative bleeding, number and diameters of gallstones, as well as the incidence of infection, bile leakage, and hospitalization duration.
3. Follow-up Data: Conduct postoperative follow-ups of no less than twelve months on all patients. Record and compare the incidence of postoperative complications, including severe pancreatitis, bile duct perforation, duodenal perforation, major bleeding, and bile duct stricture.

11. Statistical analysis

1. Apply SPSS22.0 software for the statistical analysis of data in this study. Express enumeration data, such as perioperative complications and gender, as case numbers and percentages (%), and perform Chi-square tests for comparisons between groups. Present measurement data following a normal distribution, such as albumin and body mass index, as mean ± standard deviation, and conduct comparisons among groups using independent sample t-tests. Express measurement data following a skewed distribution, such as AST and ALT, as median (Q1, Q3), and perform comparisons between groups using Mann-Whitney U tests. Consider a P value lower than 0.05 (P<0.05) to indicate a statistically significant difference.

A total of 58 patients underwent the laparoscopic transcystic ultra-fine choledochoscopy procedure. The baseline characteristics showed no statistically significant differences (all P>0.05) (see Table 1).

The procedural success rate for transcystic scope insertion on the first attempt was 87.9% (51/58). In 7 cases, the cystic duct required dilation or a minimal extension of the incision to allow choledochoscope passage. There were 2 (3.4%) conversions to formal laparoscopic choledochotomy due to an inaccessible cystic duct; both were managed with T-tube placement and included in the T-tube group for analysis.

Perioperative outcomes specific to the execution of the transcystic ultra-fine choledochoscopy protocol are summarized in Table 2. Operative time, intraoperative blood loss, stone number, and stone diameter were comparable between the two groups (all P > 0.05). The median T-tube dwell time in the T-tube group was 45 days (IQR 42-49 days). Two patients in the T-tube group experienced minor T-tube-related issues: one with self-limited peri-tube bile leakage and another with accidental partial dislodgement that required bedside repositioning.

Postoperative recovery and complication outcomes are detailed in Table 3. Recovery metrics favored the primary suture group, although not all differences reached statistical significance. The time to first ambulation was shorter in the primary suture group (P>0.05), and the duration of abdominal drainage was also reduced (P>0.05). The overall complication rate was 10.3% (6/58). Complications were classified according to the Clavien-Dindo system. In the primary suture group (n=28), there were 3 Grade I complications (bile leakage managed conservatively with prolonged drainage) and 1 Grade II complication (postoperative infection requiring intravenous antibiotics). In the T-tube group (n=30), there was 1 Grade I complication (self-limited bile leakage) and 1 Grade IIIa complication (T-tube dislodgement requiring radiographic-guided repositioning). No Grade IV or V complications occurred.

All patients were followed for a median of 24 months (range 12-40 months). Long-term follow-up was based on clinical assessment (symptom inquiry and physical examination) and liver function tests. No cases of severe pancreatitis, biliary perforation, duodenal perforation, or major hemorrhage were recorded. During the follow-up period, which relied on clinical and biochemical monitoring, no symptomatic biliary strictures or stone recurrences were identified.

Figure 1: Flowchart of patient enrollment and procedural management. Please click here to view a larger version of this figure.

Table 1: Comparison of baseline patient characteristics.

Table 2: Perioperative outcomes of laparoscopic transcystic ultra-fine choledochoscopy.

Table 3: Postoperative recovery metrics and complications.

Table 4: Comparison of surgical techniques for choledocholithiasis.

Approximately one-fifth of patients with cholecystolithiasis also suffer from choledocholithiasis. Stones can cause biliary obstruction, resulting in such symptoms as abdominal pain or jaundice among patients who will experience acute cholangitis, pancreatitis, or even death in severe cases^12,13. For patients with cholecystolithiasis in combination with choledocholithiasis, the traditional method of open common bile duct exploration is commonly used for stone retrieval. However, this surgical method can lead to relatively great harm to patients, easily causing such complications as stone recurrence and common bile duct stricture. On the other hand, the application of the EST+ERCP surgical method can result in bleeding, infections, perforation, or even death among patients with incisions of Oddi sphincters^14,15,16,17. Compared with those two surgical methods mentioned above, LCBDE is extensively employed in the management of choledocholithiasis with its advantages of minimal trauma, few complications, maximum avoidance of the need for secondary surgery (LC+EST), and reduced risk of compromised integrity of Oddi sphincter structures^19,20. Al-Ardah M et al.^21,22 argued that LCBDE represents an effective and safe procedural method for the treatment of patients with paediatric choledocholithiasis or choledocholithiasis patients with failed ERCP. Therefore, LCBDE is an important method for the feasible and safe treatment of choledocholithiasis in clinics, currently^23,24.

Currently, no consensus has been reached on the optimal closure of the common bile duct incision²⁵. In the treatment of choledocholithiasis with LCBDE, there are three options for incision closure, namely, T-tube placement, internal drainage tube placement (self-shedding bracket), and primary suture. Internal drainage tube placement can lead to such side effects as pancreatitis complication, no shedding of brackets during the short term with the need for removal through duodenoscopy, migration of the drainage tube into the liver, and no bile duct support and internal drainage achieved with postoperative shedding of the internal drainage tube within the short term. Meanwhile, during operations, consumable items such as ultra-slippery guide wires and pig-tail catheters should be used, and related medical costs should be increased. Currently, only a few treatment cases with internal drainage tube placement have been reported without large-scale popularization and application in clinical practices^26,27. T-tube placement and single suture are still common surgical methods for patients after common bile ducts exploration. T-tube draining reduces the internal pressure in common bile ducts, decreasing the probability of postprocedural complications like bile leaks and bile duct stricture. In addition, residual stones can be detected and removed through the T-tube sinus tact with T-tube placement. However, issues such as T-tube displacement, loss of bile causing water-electrolyte imbalance, long time of T-tube retention, with secondary peritonitis after removing the T-tube among postoperative patients will significantly impact their life quality^28,29,30,31. Studies have shown that these drawbacks can be avoided in LCBDE with primary suture, which could be superior to T-tube drainage in terms of operative duration, hospitalization duration, with intraoperative bleeding, and more suitable for normal physiological conditions of human bodies^32,33. Nevertheless, there are few reports on whether primary suture or T-tube placement is to be conducted after Small-Diameter common bile duct stone exploration. The author believes that not only should patients' systemic factors be considered, but local conditions of their common bile ducts also need to be taken into account. Furthermore, the minimally invasive surgical skills of surgical operators should not be overlooked. Patients with Small-Diameter choledocholithiasis normally exhibit a short formation time of gallstones and relatively mild biliary inflammation, with relatively good patency at the distal ends of common bile ducts. Therefore, primary sutures are more likely to be performed among these patients after stone retrieval surgery. The comparable outcomes, particularly the absence of postoperative biliary strictures in either group, can be attributed to several key technical aspects of our protocol that mitigate the inherent risks associated with small-diameter bile ducts. To provide a clearer overview, we have summarized the key characteristics, advantages, and disadvantages of the main surgical techniques for managing choledocholithiasis in Table 4. First and foremost, the use of the transcystic approach with an ultra-fine choledochoscope is pivotal. By avoiding a formal choledochotomy on the delicate, non-dilated common bile duct, this method eliminates the primary insult that can lead to scarring and subsequent stricture formation. The minimal access via the cystic duct preserves the structural integrity and blood supply of the common bile duct wall. Secondly, when primary suture was performed, we employed a meticulous suturing technique with fine absorbable monofilament sutures, taking small bites (approximately 1 mm from the edge) with close spacing (1-1.5 mm). This precise closure ensures a water-tight seal without causing tissue ischemia or narrowing of the lumen, which is crucial in a duct with little inherent caliber to spare. The intraoperative leak test provided immediate confirmation of a secure closure. Therefore, the combination of a less invasive access route and a precision suturing technique likely underlies the low stricture rate observed in our cohort, even in patients with bile ducts ≤0.8 cm, demonstrating that primary suture is not only feasible but also safe when these technical conditions are met. The bile leakage rate in the primary suture group was 14.28%. All cases were managed conservatively with prolonged abdominal drainage and resolved without reoperation. We attribute these leaks to the learning curve associated with precise suturing in small-caliber ducts and the selection of cases with borderline inflammatory changes. With improved case selection and suturing technique, the leakage rate decreased in later cases.

For those patients with Small-Diameter choledocholithiasis, in order to avoid postoperative bile duct stricture after the incisions of the common bile ducts, ultra-fine choledochoscopy was employed for exploration and retrieval of stones in the common bile ducts via the cystic ducts in this study, with primary suture or T-tube placement applied depending on the situation of common bile ducts exploration. Some notes summarized by the author are as follows^{34,35,36,37,38}: (1) Instruments or probes can be used to help dilate cystic ducts during the operation or make some minimal incisions along the cystic ducts to allow choledochoscopes to be successfully inserted into the bile ducts. (2) In cases of impacted stones at the distal ends of common bile ducts or stones with relatively large diameters causing retrieval difficulties, holmium laser lithotripsy with choledochoscope can be used to fragment stones into fine particles or sandy particles for subsequent stone retrieval and rinsing with a large amount of saline solution. In addition, such lithotripsies as ultrasound and plasma can also be used. (3) It is not a common symptom that a cystic ducts enters into the common bile duct above the duodenum or through the rear of the common hepatic ducts. However, such an anomaly can affect the excretion of bile, constituting a major cause of biliary inflammation, bile stasis, and bile duct stones. Therefore, it is recommended that intraoperative clamping and dissecting of the cystic duct 0.5 cm-1.0 cm from the common bile ducts should be performed, with laparoscopic common bile duct explorations in combination with T-tube drainage. (4) Surgery of Small-Diameter choledocholithiasis is relatively difficult, requiring extensive experience of surgical operators in laparoscopy. After the exploration of the cystic duct, the laparoscopy method can be confirmed. Choledochoscopes can be inserted into the common bile ducts via the cystic ducts or through incisions at the junction of the cystic ducts and the common hepatic ducts. After the confirmation of no residual stones through choledochoscopy, the head end of the stone basket can be inserted into the duodenal lumen via the papilla. After the opening of the stone basket head end, the stone basket is pulled into the bile duct, ensuring the complete removal of stones and patency of distal bile ducts. (5) Both stitch space and margin during primary suture should be maintained at 1 mm, which can help reduce the risk of excessive stitching leading to bile duct stricture. (6) For patients with ongoing inflammatory exudation in the bile duct lumens or significant edemas on the bile duct walls, after the complete removal of stones, T-tubes should be used as supports in their common bile ducts for continuous bile drainage and then removed after 1.5-2 months.

This study has the following two drawbacks: (1) This is a retrospective and non-randomized study with a single center. Limited patient cases have been included in this study, which could lead to result bias. Next, prospective and randomized controlled research with multiple centers should be conducted for validation. (2) The management of cholecystolithiasis and Small-Diameter choledocholithiasis via laparoscopic transcystic ultra-fine choledochoscopy, there are complex pathological backgrounds with relatively small diameters of common bile ducts, which can easily lead to iatrogenic biliary injuries. This surgical method imposes a strict requirement for clinical experiences and surgical proficiency of surgical operators and teams, constituting a bottleneck for the widespread adoption of this technique in primary care hospitals.

Beyond the comparable clinical outcomes, the laparoscopic transcystic ultra-fine choledochoscopy protocol demonstrates distinct advantages in operative efficiency and workflow practicality. By utilizing the cystic duct as the access point, it obviates the need for a formal choledochotomy, thereby simplifying the procedural steps and potentially reducing operative time. The use of an ultra-fine choledochoscope facilitates navigation within nondilated bile ducts, and the integration of holmium laser lithotripsy provides a definitive solution for managing impacted or large stones intraoperatively. The protocol's structured decision points regarding duct closure, primary suture for favorable conditions versus T-tube placement for complicated cases, enhance its usability by allowing for tailored patient management based on real-time surgical findings. This streamlined yet adaptable workflow makes it a valuable technique for surgeons proficient in laparoscopy.

The laparoscopic transcystic ultra-fine choledochoscopy technique holds promise for broader clinical implementation. It could be particularly advantageous in specific scenarios, such as the management of choledocholithiasis in pediatric patients or in adults with nondilated ducts where ERCP has failed or is contraindicated. Furthermore, its integration into structured training programs for advanced laparoscopic surgery could standardize the procedure and facilitate its adoption in tertiary care centers. Future work may also explore its utility in the acute care surgery setting for patients presenting with cholangitis or gallstone pancreatitis, potentially offering a definitive single-stage minimally invasive solution.

In summary, the laparoscopic transcystic approach utilizing ultra-fine choledochoscopy is a feasible and safe method for managing cholecystolithiasis and Small-Diameter choledocholithiasis, provided it is performed by surgical teams with rich laparoscopic experiences based on different surgical methods selected depending on the results of bile duct exploration, precise preoperative imaging assessment, and meticulous minimally invasive operations during surgery. This treatment method will not bring about additional short-term or long-term complications after surgery.