https://orcid.org/0000-0002-8993-7769
Abstract
Gallbladder duplication is a rare congenital anomaly (1 in 4000 births) that can mimic other biliary pathologies, risking iatrogenic injury. A 61-year-old male presented with fever, right upper quadrant pain, and elevated aminotransferases. Contrast-enhanced computed tomography and magnetic resonance imaging initially suggested a 3.6-cm Todani type II choledochal cyst posterior to the gallbladder. Suspecting duplication, surgeons utilized a single-port robotic approach via the da Vinci SP system. Intraoperatively, two distinct gallbladders with independent cystic ducts were identified and successfully resected without complications. The operative time was 65 min, and histopathology confirmed chronic cholecystitis in both specimens. This case highlights the difficulty of differentiating gallbladder duplication from a type II choledochal cyst using cross-sectional imaging. Single-port robotic cholecystectomy offers enhanced visualization and articulating instrumentation, facilitating the safe, precise management of complex biliary anomalies.
Introduction
Gallbladder duplication is an extremely rare congenital malformation, with an estimated incidence of ~1 in 4000 live births [1, 2]. Although frequently asymptomatic, it becomes clinically meaningful when gallstone-related diseases or cholecystitis occurs [1, 3]. An unrecognized accessory gallbladder or aberrant cystic duct anatomy poses a substantial risk for incomplete surgery or iatrogenic bile duct injury (BDI) [4, 5].
Despite advances in imaging, preoperative diagnosis remains difficult. Ultrasonography has a relatively low sensitivity of ~66%, whereas magnetic resonance cholangiopancreatography (MRCP) offers a higher diagnostic yield of up to 97% [2, 6]. Nevertheless, duplicated gallbladders can closely mimic other conditions, most notably Todani type II choledochal cysts, which represent only 2% of choledochal cysts and appear as true diverticula of the common bile duct [2].
Robotic single-port surgery aims to overcome the ergonomic limitations of conventional single-incision laparoscopic approaches. The da Vinci SP platform has demonstrated safety and efficacy in various biliary procedures [7, 8]; however, reports on its application in duplicated gallbladders remain limited [9–12].
Case presentation
A 61-year-old man presented to our hospital with a 3-day history of fever and abdominal pain. Clinical examination revealed tenderness in the upper right quadrant. Laboratory investigations showed a white blood cell count of 11 500/mm3 and elevated aspartate aminotransferase and alanine aminotransferase levels (>100 IU/L), whereas total bilirubin and alkaline phosphatase levels were within normal ranges. The patient had no other medical history or previous surgical interventions.
Initial contrast-enhanced computed tomography (CT) and magnetic resonance imaging/MRCP demonstrated two cystic structures. A 3.6-cm saccular lesion was noted posterior to the primary gallbladder. The radiology team interpreted this as a Todani type II choledochal cyst (diverticulum of the common bile duct) (Fig. 1). However, upon detailed multidisciplinary review, the presence of two separate ductal structures suggested a potential gallbladder duplication.
Preoperative imaging suggesting a choledochal cyst but ultimately consistent with duplicated gallbladder. (A and B) Contrast-enhanced CT images show a 3.6-cm saccular cystic lesion posterior to the gallbladder, initially interpreted as a Todani type II choledochal cyst (true diverticulum of the common hepatic duct). (C and D) MRCP images demonstrate two separate gallbladders with distinct cystic ducts: one draining into the common bile duct and the other arising near the right posterior hepatic duct. These findings were more suggestive of a duplicated gallbladder with dual cystic duct anatomy.
Based on this suspicion, a single-port robotic cholecystectomy using the da Vinci SP system was planned. Intraoperatively, a 2.5-cm transumbilical incision was made, and two distinct gallbladders were observed within the gallbladder fossa. The primary gallbladder was bile-filled, while the accessory gallbladder exhibited hydropic changes (Fig. 2). Notably, each gallbladder had an independent cystic duct and cystic artery (Fig. 3).
Intraoperative confirmation of a duplicated gallbladder. (A) Two separate gallbladders are identified intraoperatively. (B) Indocyanine green (ICG) fluorescence imaging demonstrates uptake in the first gallbladder, while the second gallbladder shows no fluorescence, raising suspicion of a non-communicating second gallbladder. (C and D) Micro-perforation of the second gallbladder reveals clear mucinous fluid rather than bile, which was aspirated. This supports the absence of biliary communication and explains the lack of ICG fluorescence.
Dual cystic duct anatomy with functional discrepancy demonstrated by indocyanine green (ICG) fluorescence. (A and B) The first cystic duct shows clear visualization and strong ICG fluorescence, confirming normal biliary communication. (C, D) The second cystic duct is independently identifiable but demonstrates no ICG fluorescence, suggesting a non-communicating duct associated with the second gallbladder.
Meticulous dissection was performed to achieve a critical view of safety for both structures before ligation (Fig. 3). Near-infrared fluorescence with indocyanine green (ICG) was used to clearly delineate the biliary tree (Fig. 4, Video 1).
Intraoperative identification of dual cystic arteries and ducts in duplicated gallbladder. (A and B) Intraoperative views demonstrate two distinct cystic arteries supplying each gallbladder. Each cystic artery is individually identified, clipped, and divided. (C and D) Final operative and indocyanine green fluorescence views demonstrating the anatomical relationships of the first and second cystic ducts and their corresponding cystic arteries after complete dissection.
Both specimens were removed through the umbilical region. The total operative time was 65 min, with minimal blood loss. The patient was discharged on postoperative day 2. Histopathological examination confirmed chronic cholecystitis in both gallbladders, with no evidence of malignancy. The patient expressed high satisfaction with the clinical outcome, particularly noting the minimal postoperative pain and the cosmetic advantage.
This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this case report and images.
Discussion
This case highlights the critical diagnostic pitfall of mistaking a duplicated gallbladder for a Todani type II choledochal cyst. As both of these entities can appear as saccular structures connected to the extrahepatic bile duct, imaging misinterpretation can lead to unnecessary bile duct resection or reconstruction, which are required for choledochal cysts but not for gallbladder duplication [13].
In a systematic review of gallbladder duplications, the cystic duct was found to be common to both gallbladders in 43% of cases and separate in 50% [4]. This high frequency of separate ductal anatomy underscores the necessity of assuming the existence of ‘two cystic ducts’ until proven otherwise during surgery to prevent iatrogenic BDI. Current guidelines for safe cholecystectomy emphasize clear anatomical identification and the use of intraoperative imaging or ‘bail-out’ strategies when anatomy is unclear [14].
In our case, after the division of the first cystic duct, the second cystic duct was carefully isolated but not immediately transected. To minimize the risk of unintended BDI, a fundus-first (top-down) approach was adopted to detach the gallbladder from the liver bed. Next, the second cystic duct was identified, safely clipped, and divided after complete mobilization. This stepwise approach reflects a practical bailout strategy in the setting of an unclear biliary anatomy.
The da Vinci SP platform offers several technical advantages in complex biliary cases. Unlike multiport systems, the SP system allows three-wristed instruments and a fully articulating three-dimensional camera to operate through a single 25-mm cannula, providing stable visualization and superior dexterity in narrow fields [7]. These features are particularly beneficial when dealing with an anomalous biliary anatomy, where precise dissection is essential.
Furthermore, the integration of ICG fluorescence cholangiography enhanced real-time identification of biliary structures. Previous studies have demonstrated that near-infrared fluorescence imaging can significantly improve the visualization of the cystic duct–common bile duct junction, thereby reducing the risk of BDI [15]. In the present case, ICG imaging played a crucial role in confirming the separate entry points of the two cystic ducts and guiding safe dissection.
Conclusions
Gallbladder duplication is a rare but surgically meaningful anomaly that may mimic Todani type II choledochal cysts. An accurate preoperative evaluation and a high index of suspicion are essential to avoid misdiagnosis and inappropriate surgical planning.
A single-port robotic cholecystectomy combined with ICG fluorescence imaging is a safe and effective approach for managing complex biliary anatomy by enabling precise dissection and clear anatomical visualization.
Surgeons should maintain a high index of suspicion for gallbladder duplication and adopt flexible intraoperative strategies to ensure patient safety.
Author contributions
Study concept: EJJ; Drafting: KWK; Critical revision and editing: EJJ. Both authors have read and approved the final version of the manuscript.
Conflicts of interest
All authors have completed the ICMJE uniform disclosure form. The authors have no competing interests to declare.
Funding
None declared.
Ethical statement
This study was approved by the Institutional Review Board (IRB) of Dong-A University (IRB No. DAUH IRB-26-029). Written informed consent was obtained from the patient for the publication of this case report.
Reporting checklist
The authors have completed the CARE reporting checklist.
