Left-Sided Gallbladder in the Absence of Situs Inversus: Case Report and Surgical Implications

Introduction

Sinistroposition of the gallbladder (SPGB), defined as localization of the gallbladder on the left side of the body, is a rare condition most commonly identified incidentally during surgery, such as laparoscopic cholecystectomy, and less frequently on imaging studies. In most individuals, the gallbladder is located on the anteroinferior surface of the liver within the right lobe, projecting to the anterior abdominal wall at the level of the ninth right rib along the right midclavicular line. First described by Hochstetter in 1886, left-sided gallbladder remains a rare anatomic anomaly. In a multicenter study of patients undergoing laparoscopic cholecystectomy, its reported prevalence was 0.3% [1,2]. This anomaly may occur as part of situs inversus, in which other organs are transposed, or in isolation, as in the case described here.

Case Report

A 53-year-old woman followed on an outpatient basis presented with a long history of typical symptoms of cholelithiasis, including severe epigastric pain radiating to the back or right shoulder, nausea, vomiting, and intolerance to fatty foods. She denied jaundice, dark urine, or acholic stools.

Outpatient abdominal ultrasonography demonstrated gallstones within the gallbladder, without evidence of complications such as cholecystitis (wall thickening or impacted stones in the infundibulum), choledocholithiasis, or biliary dilation. SPGB was not identified; no additional findings warranted further evaluation with more sensitive imaging modalities, such as magnetic resonance cholangiopancreatography, for preoperative diagnosis of this anatomic variant. Elective laparoscopic cholecystectomy was therefore indicated for symptom management. During the procedure, the gallbladder was observed entirely to the left of the round ligament, beneath hepatic segment III (Figures 1, 2), establishing the diagnosis of sinistroposition. Careful dissection of Calot’s triangle was performed in accordance with the principles of the Critical View of Safety; the cystic duct and cystic artery were isolated, and normal biliary anatomy was confirmed. In the absence of laboratory abnormalities or clinical features suggestive of distal biliary obstruction – such as choledocholithiasis, cholestatic jaundice, strictures, or ductal dilation previously excluded on preoperative ultrasonography – intraoperative cholangiography was not performed. The procedure proceeded with clipping of the cystic duct and cystic artery, followed by removal of the gallbladder (Figure 3).

The procedure was uneventful, and the patient was discharged on postoperative day 1 without symptoms. At outpatient follow-up on postoperative day 7 and again on day 30, she continued to lack laboratory abnormalities or clinical symptoms suggestive of surgical complications, such as hemorrhage, infection, or inadvertent bile duct injury.

Discussion

The liver is located in the right upper quadrant of the abdomen. Its inferior (visceral) surface contains multiple fissures and grooves formed by direct contact with surrounding organs, including the gallbladder. According to the Brisbane classification, the liver is divided into right and left hemilivers, then subdivided into 8 segments [3,4].

The gallbladder is a hollow intraperitoneal organ situated on the visceral surface of the liver, typically between the right and quadrate lobes. It is divided into 3 portions: the fundus (most lateral part), which projects to the anterior abdominal wall at the intersection of the ninth costal cartilage and the lateral border of the rectus abdominis muscle; the body, which constitutes the largest portion and lies within the gallbladder fossa of the liver; and the neck, also referred to as the infundibulum, which contains spiral mucosal folds that taper into the cystic duct. The primary function of the gallbladder is to store and concentrate bile produced by the liver, which is subsequently transported to the duodenum through the biliary tract [5,6].

Several anatomic variations of the gallbladder have been described, most of which involve its size and shape. Positional variations occur less frequently and include gallbladders located higher or lower than usual, or within the left lobe of the liver [7]. When the gallbladder is not in its orthotopic position, it may be classified as sinistropositioned, mediopositioned, intrahepatic, transverse, or posterior. Three types of gallbladder sinistroposition have been described: association with situs viscerum inversus; aberrant left-sided positioning to the left of the falciform ligament; and true sinistroposition, in which the gallbladder is located in hepatic segment III without situs inversus and with a normally positioned falciform ligament [8,9].

Two main variants of gallbladder malposition have been described: medioposition and sinistroposition. In medioposition, the gallbladder is medially displaced along the inferior surface of segment IV but remains to the right of the falciform ligament. In SPGB, the gallbladder lies beneath the left lobe (segment III), to the left of the round ligament. A left-sided gallbladder may occur as part of situs inversus; when found in isolation, it represents an extremely rare anomaly. In the present case, the patient exhibited isolated malposition of the gallbladder [9].

SPGB is frequently associated with concomitant anatomic variations of the cystic duct. The most common variant involves the cystic duct entering the right lateral aspect of the common bile duct after coursing in an arched trajectory over it (65.5%) [9]. Other described variants include communication with the left lateral aspect of the common bile duct, the left hepatic duct, the right hepatic duct, or a branch of the right biliary tree. In our patient, the intraoperative biliary anatomy appeared normal, with clear visualization of the cystic duct, thereby eliminating the need for intraoperative cholangiography.

Surgical management of SPGB requires caution. Patients with SPGB exhibit an increased risk of iatrogenic bile duct injury during cholecystectomy, reported in up to 4.4% of cases compared with a bile duct injury rate of 0.3% during standard laparoscopic cholecystectomy in the absence of such anatomic variations [9,10]. For preoperatively diagnosed SPGB, technical adaptations have been proposed, including relocation of the epigastric trocar to Palmer’s point, redirection of the epigastric port to the left of the falciform ligament, placement of accessory trocars, or creation of a mirrored port configuration to the left of the midline [11].

The leading cause of complex iatrogenic bile duct injury is misidentification of biliary structures. However, adherence to Strasberg’s 1995 principles of the Critical View of Safety, which were applied in this case, substantially reduces the risk of such injuries. The Culture of Safety in Cholecystectomy initiative, first introduced in 2013, standardized the essential steps required to achieve the Critical View of Safety and has since been incorporated into the SAGES Safe Cholecystectomy Program (www.sages.org/safe-cholecystectomy-program). Additional maneuvers, such as the “Shoeshine Maneuver” described by an author of the present report (Ribeiro), aim to ensure adequate exposure of Calot’s triangle, particularly in acute or complex cases [12–14].

SPGB generally does not produce specific symptoms and – in most cases – is discovered incidentally during surgery rather than on preoperative imaging, consistent with findings in the present case.

Conclusions

SPGB is a rare anatomic variation associated with an increased risk of bile duct injury. In the present case, laparoscopic cholecystectomy was safely performed through meticulous dissection and achievement of the Critical View of Safety. Although intraoperative cholangiography was not performed, it may enhance anatomic delineation; advanced imaging modalities may facilitate preoperative diagnosis and surgical planning.