Introduction

The gallbladder is known for a wide range of congenital anatomical variations, which often pose significant challenges during surgical interventions. Among these, the duplicated gallbladder is an exceedingly rare anomaly with an estimated incidence of approximately 1 in 4,000 live births [1, 2]. They are often asymptomatic but can become clinically significant when complicated by cholelithiasis or when they coexist with other pathologies. Surgeons need to be aware of this congenital abnormality due to its association with anatomical variations of the hepatic artery and cystic duct. There are two classification systems for duplicated gallbladder, namely Boyden's classification and Harlaftis classification [3]. Boyden's classification is more widely accepted due to its simplicity, and it describes two main types :

• Vesica fellea divisa: wherein there is a bilobed gallbladder draining into a single cystic duct,
• Vesica fellea duplex: wherein gallbladder is truly duplicated and draining into separate cystic ducts. This type is sub-classified into the “Y-shaped type” (two cystic ducts uniting and then entering the common bile duct), and the “H-shaped or ductular type” (two cystic ducts entering separately into the common bile duct).

Hydatid disease, caused by Echinococcus species, remains a significant public health concern in endemic regions. While the liver is the most common site of infection (70%), splenic hydatid cysts are rare, accounting for only up to 5% of all cases [4]. This rarity is attributed to the "filtering" action of the liver and lungs, which act as the first and second barriers to the systemic circulation of embryos.

The simultaneous clinical presentation of a symptomatic splenic hydatid cyst and a congenital vesica fellea divisa represents an exceptionally rare surgical intersection. We herein present one such case to highlight the diagnostic challenges and technical nuances required to manage such concurrent pathologies in the presence of a frozen abdomen.

Case Presentation

A 30-year-old male presented with a one-year history of recurrent vomiting and pain in the right hypochondrium (RHC). His past medical history was significant for an open surgical intervention for hepatic hydatid disease performed three years prior. Ultrasonography (USG) suggested the presence of a splenic cyst and cholelithiasis. A subsequent Computed Tomography (CT) scan confirmed a large cystic lesion in the spleen, characteristic of a Gharbi Type 1 - hydatid cyst (Figure 1 A, B), alongside a distended gallbladder containing multiple calculi. The splenic cyst measured approximately 12 x 10 x 9 cm with an estimated volume of about 550 mL. Serological testing, specifically Enzyme-Linked Immunosorbent Assay (ELISA) and Indirect Hemagglutination (IHA) for Echinococcus antibodies, returned positive results, providing immunological confirmation of hydatid disease.

The procedure began with a diagnostic laparoscopy. To avoid suspected dense adhesions from the previous hepatic surgery, access was gained via Palmer’s point. The splenic hydatid cyst was successfully managed using a laparoscopic approach (Figure 1 C-G). However, upon exploration of the right hypochondrium, "frozen" anatomy was encountered. Dense, matted adhesions involving the omentum, colon, stomach, and duodenum were found at the gallbladder bed, resulting from the previous open hepatic surgery. Due to the inability to safely visualize Calot’s triangle, the team converted to an open approach via a right subcostal incision over the old scar.

Following extensive adhesiolysis, a congenital anomaly was discovered: a bilobed gallbladder (vesica fellea divisa). Both lobes were filled with multiple calculi. Meticulous dissection revealed that both lobes drained into a single cystic duct and were supplied by a single cystic artery (Figure 1 H). A total cholecystectomy was successfully performed.

Histopathological examination confirmed the diagnosis of a hydatid cyst of the spleen and revealed features of chronic cholecystitis in the gallbladder specimen, with no evidence of malignancy in either lobe. The patient's postoperative recovery was uneventful. At the six-month follow-up, the patient reported complete resolution of symptoms and expressed high satisfaction with the surgical outcome.

Figure 1: Radiological and Intraoperative Findings. (A, B) Axial and coronal sections of the abdominal computed tomography (CT) scan demonstrating a large, unilocular splenic hydatid cyst. (C–G) Sequential intraoperative steps showing the laparoscopic evacuation and management of the splenic hydatid cyst. (H) Intraoperative view after conversion to open surgery, showing the two distinct lobes of the bilobed gallbladder (vesica fellea divisa) held with surgical instruments for anatomical delineation.

Discussion

The discovery of a bilobed gallbladder intraoperatively is a rare event that demands meticulous surgical technique to ensure the "critical view of safety" and prevent iatrogenic injury. Based on the Boyden classification, our case fits the description of vesica fellea divisa. In this subtype, the gallbladder primordium divides during the 5th or 6th week of gestation, resulting in two lobes that communicate through a single cystic duct [3].

In this patient, the surgical complexity was significantly increased by a prior open hepatic hydatid surgery. Previous interventions for hydatid disease are often associated with dense, "matted" adhesions involving the omentum, stomach, and duodenum, leading to what is clinically described as a frozen abdomen [5]. While the splenic hydatid cyst was successfully managed laparoscopically via Palmer’s point to avoid adhesions, the gallbladder pathology necessitated conversion to an open approach. Literature suggests that conversion rates are higher in patients with previous upper abdominal surgeries due to the high risk of visceral injury during laparoscopic dissection of the Calot’s triangle [6].

The presence of multiple gallbladders or lobes does not necessarily increase the risk of cholelithiasis; however, if stones are present, they usually affect both lobes, as seen in our patient. It is imperative for the surgeon to excise both lobes entirely to prevent "stump cholecystitis" or recurrent symptoms from a residual lobe [7].

This case highlights the importance of maintaining a high index of suspicion for anatomical variations even when preoperative imaging is inconclusive. The successful management of a rare splenic hydatid cyst alongside a congenital biliary anomaly underscores the need for surgical flexibility and careful intraoperative anatomical delineation.

Conclusion

This case emphasizes the necessity of surgical flexibility when managing rare congenital and infective pathologies in a re-operative field. The presence of a "frozen abdomen" often necessitates a low threshold for conversion from laparoscopy to an open approach to ensure the safe visualization of anatomical landmarks. Intraoperatively, the discovery of a vesica fellea divisa demands meticulous dissection to identify the single cystic duct and artery. Ultimately, thorough intraoperative evaluation and complete resection of all gallbladder lobes are paramount to preventing recurrent symptoms and ensuring successful surgical outcomes.

Informed Consent

Written informed consent was obtained from the patient for the publication of this case report and any accompanying images.

Acknowledgments

The authors would like to express their sincere gratitude to the patient for his cooperation and for providing consent to share this clinical finding with the medical community.

References

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