Intraoperative Detection of Cholecystohepatic Duct

INTRODUCTION

Biliary anatomical variants represent a significant challenge during hepatobiliary surgery, particularly during cholecystectomy. Cholecystohepatic ducts are defined as aberrant hepatic ducts that drain directly into the gallbladder rather than into the common biliary system.^[1] These ducts are distinctly different from the more commonly encountered bile ducts of Luschka, which are thin (<1 mm), vestigial ducts in the gallbladder bed that form a meshwork of tiny ductules.^[2] In contrast, cholecystohepatic ducts are thicker structures (typically 1-3 mm in diameter) that serve as the primary drainage pathway for variable portions of the right hepatic lobe.^[1-4]

The prevalence of cholecystohepatic ducts is reported to be less than 1% of cases, making them an uncommon finding during surgery.^[5-7] Their embryological origin likely stems from persistent fetal connections between hepatic ducts and the gallbladder, with failed recanalization of the common hepatic duct during development.^[1] The clinical significance of these ducts is substantial, as unrecognized injury during cholecystectomy can result in persistent bile leakage, cholangitis, or segmental biliary obstruction that may lead to atrophy of the associated liver territory.^[1,5]

The increasing prevalence of laparoscopic cholecystectomy has renewed interest in these anatomical variants, as limited field of view and 2D visualization may increase the risk of iatrogenic injury during laparoscopic procedures. Recognition of these variants, either preoperatively or intraoperatively, is crucial for preventing complications and determining appropriate management strategies.

CASE SERIES

This case series presents eight patients with cholecystohepatic ducts identified during laparoscopic cholecystectomy performed at our institution between January 2017 and December 2023. All patients were initially diagnosed with symptomatic gallstone disease and scheduled for laparoscopic cholecystectomy. The cholecystohepatic ducts were detected intraoperatively in all cases, with subsequent management tailored to each specific situation.

Our standard surgical approach for laparoscopic cholecystectomy involves a four-port technique with establishment of the critical view of safety (CVS) before division of the cystic structures.^[8] In cases where biliary anatomical variants were suspected either preoperatively or intraoperatively, additional measures, including meticulous dissection and intraoperative cholangiography, were employed. When cholecystohepatic ducts were identified, management decisions were based on the duct diameter, estimated drainage area, and overall clinical context.

A preoperative ultrasound showed multiple gallstones without biliary dilation and normal biochemical parameters of liver function. During laparoscopic cholecystectomy, after establishing the CVS and dividing the cystic artery and duct, a separate 1-2 mm tubular structure was identified connecting the neck of the gallbladder to the liver parenchyma. This was recognized as a potential cholecystohepatic duct. Intraoperative cholangiography confirmed that it drained a small portion of the right liver. The duct was double clipped and divided without postoperative complications [Figure 1].

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Figure 1:

Cholecystohepatic Duct. (a) An arrow showing golden yellow bile coming from the cholecystohepatic duct identified intraoperatively. (b) Arrow showing management of cholecystohepatic duct done by clipping and division.

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Management strategies varied based on the estimated drainage area and duct diameter. For ducts with small drainage areas (five cases), simple clipping and division were performed. In two cases with larger drainage territories, preservation of the duct was attempted through subtotal cholecystectomy. In one case with a large drainage area but where preservation was not feasible, hepaticojejunostomy was performed.

RESULTS

None of the eight cholecystohepatic ducts in our series were identified preoperatively, despite all patients undergoing abdominal ultrasonography. This highlights the challenge of preoperative detection of this rare anatomical variant and reinforces the need for heightened awareness during surgery.

The CVS technique facilitated the identification of cholecystohepatic ducts in five cases by enabling complete visualization of structures entering the gallbladder.^[8] Our series of eight cases represents one of the larger collections of cholecystohepatic ducts [Table 1] reported in the literature, given their rarity (less than 1% prevalence). All patients were female (age range: 32–68 years), and no evidence of any aberrant ducts was detected on preoperative ultrasonography. Intraoperative findings showed that the diameter ranged from 1-2 mm, located in the right Hepatic bed, draining the postero-inferior liver segments into the gallbladder.

The mean CVS score^[8] was >6, and rigorous adherence to CVS criteria was followed. The management strategy was tailored to the size of the duct and the duct’s estimated drainage area, and in the small drainage area (five cases), with a duct diameter of up to 1.5 cm. Ducts were clipped and divided. There was no biliary leak, jaundice, or cholangitis at ≥1 year follow-up. In a relatively large drainage area of ducts, more than 1.5 cm, a preservation approach (three cases) that includes subtotal cholecystectomy with preservation of the gallbladder wall containing the entry point of the cholecystohepatic duct was used. In three cases, the ducts were discovered during gallbladder bed dissection. Intraoperative cholangiography, performed in three cases, was helpful in confirming the nature of these structures and assessing their drainage territory.

All patients had an uneventful recovery. Follow-up imaging (abdominal sonography) at six months demonstrated no dilation of the biliary tree in the affected segments with clipped Cholecystohepatic ducts draining larger (three patients) areas, though neither had clinical symptoms or abnormal liver function tests.

Intraoperative cholangiography, performed in three cases, was helpful in confirming the nature of these structures and assessing their drainage territory [Figure 2].

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Figure 2:

Intraoperative cholangiogram (IOC). (a) Arrow showing IOC being done through trans-cystic route. (b) Arrow showing site of biliary leakage from cholecystohepatic duct arising from segment V of liver.

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DISCUSSION

Cholecystohepatic ducts represent an important albeit rare variant of biliary anatomy. Unlike the bile ducts of Luschka, which are thin vestigial structures, cholecystohepatic ducts are substantial conduits that drain significant portions of liver parenchyma. Our findings align with previous reports indicating that these ducts most commonly drain segments of the right hepatic lobe, particularly segments V and VIII, as described by Couinaud’s nomenclature.^[1]

The clinical significance of cholecystohepatic ducts stems from the potential complications that can arise from their injury. As demonstrated in one of our cases, unrecognized transection can lead to postoperative bile leaks requiring intervention. Additionally, if a cholecystohepatic duct serves as the sole drainage pathway for a liver segment, its ligation without reconstruction could potentially lead to segmental cholangitis or atrophy.

The management approaches in our series reflect the evolving understanding of how to handle these variants. While earlier literature often emphasized the need for reconstruction of all aberrant ducts, more recent evidence suggests that smaller ducts draining limited territories can be safely ligated without significant sequelae.^[4,5]

Meyer et al. reported a case of a post-cholecystectomy bile leak resulting from an unrecognized cholecystohepatic duct.^[1] Factors making for a technically difficult surgery, such as inflammation or adhesions, can obscure the true anatomy and increase the risk of inadvertent ductal injury. The observation that none of the ducts were identified preoperatively despite imaging studies corroborates the findings by other authors that preoperative detection remains challenging, highlighting the importance of intraoperative vigilance.

Based on our experience and review of literature,^[1-5] we propose the following recommendations for surgical practice. Surgeons should maintain awareness of the possibility of cholecystohepatic ducts, particularly during difficult dissections. A critical view of the safety technique can help identify aberrant ducts entering the gallbladder. When an unexpected tubular structure is encountered, cholangiography can confirm its nature and estimate its drainage territory. Management decision based on drainage area: Small ducts can be safely ligated, while larger ducts may require preservation or reconstruction. Subtotal cholecystectomy should be considered in cases where a cholecystohepatic duct is identified, but the significance of its presence; a subtotal cholecystectomy preserving the portion of the gallbladder wall containing the duct entry point can be a safe option.

This case series has several limitations. First, the retrospective nature of data collection may have introduced selection bias. Second, the relatively short follow-up period (minimum 6 months) may not capture long-term consequences of duct ligation, such as segmental atrophy. Finally, without comprehensive preoperative mapping of biliary anatomy in all patients undergoing cholecystectomy, we cannot determine the true prevalence of this variant in our population.

CONCLUSION

Cholecystohepatic ducts represent a rare but clinically significant biliary anatomical variant that can be encountered during cholecystectomy. Our series of eight cases demonstrates that these ducts can be safely managed with appropriate intraoperative identification and decision-making. The management strategy should be tailored based on the estimated drainage territory of the duct, ranging from simple ligation for small ducts to preservation or reconstruction for larger ones.

Intraoperative cholangiography remains a valuable tool for confirming the nature of suspected cholecystohepatic ducts and guiding management decisions. Given the challenges in preoperative identification, surgeons should maintain a high index of suspicion during dissection of the gallbladder, particularly in difficult cases with inflammation or adhesions.

This case series contributes to the limited body of literature on this rare anatomical variant and provides practical guidance for surgeons who may encounter cholecystohepatic ducts during cholecystectomy. Future research utilizing advanced preoperative imaging techniques may improve our ability to detect these variants before surgery, potentially reducing the risk of iatrogenic injury and improving surgical planning.