An Unexpected Finding of Heterotopic Liver Tissue on the Gallbladder Wall During Indocyanine Green-Enhanced Laparoscopic Cholecystectomy

Abstract

Introduction:

The presence of hepatic parenchyma tissue outside the anatomical borders of the liver (choristoma) is a rare but well-documented entity in the medical and surgical literature, dating back to the end of the 18th century. ^1,2 This morphologic oddity occurs at various locations including lungs, chest wall, heart, diaphragm, kidney, adrenals, stomach, esophagus, jejunum, spleen, umbilicus, testes, and inferior vena cava. ^3,4 The aberrant liver tissue is defined as “ectopic” if no connection exists to the liver and “accessory” if there is a vascular or biliary pedicle linking it to the parent organ. From a recent comprehensive literature review by Akbulut et al, only 91 cases of ectopic or accessory liver tissue located on the gallbladder surface or mesentery were found in 72 publications. ⁵

Materials and Methods:

A 49-year-old woman with no significant comorbidities presented for an elective laparoscopic cholecystectomy for symptomatic cholelithiasis. On the day of surgery, a 25 mg vial of indocyanine green (ICG) (Verdye© Diagnostic Green GmbH, Germany) was diluted in 5 mL of sterile water. One hour before the procedure, the patient was administered 1 mL of the reconstituted solution, thus resulting in an intravenous injection of 5 mg of ICG. During the procedure, a heterotopic nodule of liver tissue was found on the medial surface of the gallbladder. The laparoscopic camera was switched from standard white light observation to near infrared. This switch showed the fluorescence-enhanced biliary anatomy caused by the hepatic metabolism of ICG and its excretion through the biliary system.

The preliminary ICG-enhanced fluorescence cholangiography revealed the presence of a small-sized biliary duct connecting the heterotopic hepatic parenchyma with the right lobe of the liver. After the safe dissection of the hepatocystic triangle with transection of the cystic duct and the cystic artery, the medial surface of the gallbladder was approached with the monopolar hook up to the level of the small bile duct arising from the accessory liver tissue. A further ICG cholangiography guided the dissection of the aberrant bile duct and its safe control with laparoscopic clips. After completion of the cholecystectomy, a final ICG cholangiography documented the absence of any additional bile ducts within the hepatic bed or biliary leaks.

Results:

After an uneventful hospital stay, the patient was discharged home on the second postoperative day. The final pathology report of the accessory liver tissue was consistent with normal microscopic hepatic features.

Conclusions:

ICG-enhanced fluorescence-guided laparoscopic technology can interpret heterogeneous biliary anatomy and detect and characterize aberrant morphologic features. These actions provide the surgeon with an adjunctive tool to manage rare entities such as the presence of choristomas.

Authors' Contributions:

All authors contributed equally to the conception, design, and writing of the article.

Patient Consent Statement:

Authors have received and archived patient consent for video recording/publication in advance of video recording of procedure.

No competing financial interests exist.

Runtime of video: 5 mins 10 secs