Left-sided gallbladder (Sinistroposition) encountered during laparoscopic cholecystectomy: A rare case report and review of the literature.

INTRODUCTION: True Left-sided gallbladder (LSG) is a rare anatomical variation with a prevalence of 0.3%. Mainly discovered during the operation, its surgical approach in the laparoscopic setting may be challenging even for an experienced surgeon. PRESENTATION OF CASE: LSG was unexpectedly discovered in a young man during laparoscopic cholecystectomy. There were no pre-operative indications of this sinistroposition. The laparoscopic cholecystectomy was performed with minor surgical modifications and it was uneventful. A meticulous review of recent literature about LSGs was conducted as well. DISCUSSION: LSG is a scarce anatomical aberration that is difficultly identified pre-operatively. Surgeons should be aware of this aberration and of its accompanying anatomical variations in order to perform a safe laparoscopic cholecystectomy.
CONCLUSION: Surgeons, by placing the patient to left-side up position, are able to expose the Calot's triangle and possible accompanying anatomical anomalies and thus perform a safe laparoscopic cholecystectomy without difficult surgical modifications.

Introduction

First described in 1886 by Hochstetter, true left-sided gallbladder (LSG) remains a scarce anomaly [1] with a prevalence of 0.3%. [2] LSG occurs when the gallbladder is found to the left of the falciform ligament, beneath the left lobe of the liver. It is located between segments III and IV or on segment III [3] to the left of the round ligament. [4] When LSG is encountered laparoscopically, surgical approach may be challenging [3] since its probable accompanying anatomical anomalies might lead to intra-operative injuries. [5] This manuscript has been reported in line with the SCARE guidelines. [6]

Presentation of case

A 31-year-old male presented with a 6-month history of colicky pain in the right upper quadrant of the abdomen, that has progressively become worse and the last three days radiated to his right flank. Clinical examination was unremarkable with no Murphy’s sign or tenderness, or palpable masses. There was no jaundice, fever or rigors. Vital signs were normal. Liver function tests including serum bilirubin, ALT and AST were within the normal spectrum. No previous surgical history existed. Abdominal ultrasound scan revealed a gall stone about 18 mm in diameter with no evidence of inflammation of the gallbladder. (Fig. 1) Owing to the patient’s clinical condition, laparoscopic cholecystectomy was scheduled. At the laparoscopy, after the insertion of a 10 mm umbilical camera port, a true left-sided gallbladder was identified, attached to the inferior surface of segment III of the liver, to the left of the round ligament. (Fig. 2, Fig. 3)Hence, surgeons decided immediately to do some minor surgical modifications to avoid hazardous complications. Firstly, subxiphoid trocar was placed more lateral to the left, under the left subcostal region, for easier surgical maneuvers. The two remained ports were inserted as usual. Secondly, patient was placed to left-side up position for better exposure of the aberrant gallbladder and Calot’s triangle. No other anatomical variations were found during the laparoscopic cholecystectomy and it continued in the usual fashion uneventfully. The LSG was finally removed through the umbilical port. The patient was discharged the 1st postoperative day without complications.

Fig. 1

Abdominal ultrasonography revealing an 18 mm gall stone.

Fig. 2

The LSG placed at the left of the round ligament of the liver. (1: aberrant gallbladder, 2: stomach, 3: left hepatic lobe, 4: right hepatic lobe, 5: round ligament).

Fig. 3

The aberrant gallbladder attached to the inferior surface of segment III of the liver (1: aberrant gallbladder, 2: stomach, 3: left hepatic lobe, 4: right hepatic lobe).

Discussion

True LSGs exist because of two possible embryological etiologies. The first mechanism is due to the attachment and migration of the gallbladder to the left lobe. Hence, the cystic duct is in normal anatomical position and crosses in front of the common duct from right to left. [5] The second one is as follows; a gallbladder develops on each side, with the left-sided gallbladder persisting on the left and the right-sided one becoming atrophic and at last disappearing. In such a case, the cystic duct joins the extrahepatic duct or left hepatic duct from the left side. [7]

Despite being located on the left side of the liver, LSGs usually present with right-sided pain when being symptomatic because, as it is believed, the visceral nerve fibers do not transpose with the gallbladder. Patients commonly present right upper quadrant discomfort, [8] pain radiating to the right flank [9] and positive Murphy’s sign. [10] Therefore, signs and symptoms could be misleading [8] and the diagnosis might be missed.

True LSG is commonly discovered at surgery, [5] since pre-operative examination may not detect the anomaly. [11] There are recent cases where neither the common pre-operative ultrasonography detect the LSG [6], [12], [13] nor the abdominal CT. [5] On the other hand, there are recent cases in which CT revealed LSG[7], [9] an if so, further study such as angiography, CT- angiography or MRI are suggested for a well-organized laparoscopic cholecystectomy [14].

A true LSG is closely associated with several anatomical anomalies than can be quite challenging during laparoscopy. [13] Such anomalies are: complete or partial situs inversus, duplicated gallbladder [16] various portal venous [17] and biliary anomalies [8], cholecystic venous anomaly [7] and atrophy of segment IV of the liver. [12] In addition, the cystic artery always crosses in front of the common bile duct from right to left. [4]

More specifically concerning the accompanying portal vein and biliary anomalies in LSG; Portal vein anatomical variations are categorized in three groups: a) trifurcation type, b) bifurcation type and c) other variations, but they’re of limited interest during laparoscopic cholecystectomy. On the other hand, bile duct anomalies have a major role in the morbidity of cholecystectomy in these patients. [13] When LSG exists, the cystic duct may join the left or right side of the common hepatic duct or may join the left hepatic duct directly. [9] Moreover there are recent case reports, referring to hypoplastic bile duct, [16] duplication of the common bile duct, [15] infraportal bile duct [7] and abnormal pancreatico-biliary duct junction. [8] Occurring to these, an intra-operative cholangiography might be used as a guide to the dissection [15] since delineating biliary anatomy. [10]

Although the presence of LSG with its usual anatomical anomalies might lead to intra-operative injuries [5], [18] laparoscopic cholecystectomy is the treatment of choice. [9] The feasibility of laparoscopic cholecystectomy with minor modifications in patients with LSG has been confirmed in various case reports as in the presented one as well. Firstly, there are recent case reports suggesting “mirror image” setup. [9], [12], [19] Others suggest use of accessory ports. [2], [8], [20] Moreover, a single-incision at the umbilicus with insertion of two ports; one for the camera and one for working is suggested. [3] Another choice suggested, is minor modification to the entry sites of the trocars, [10] as performed in the present case, with a minimal modification of the entry site of the subxiphoid trocar.

Conclusion

In conclusion, true LSG is a scarce anatomical anomaly that is difficult to be identified preoperatively. Therefore, surgeons should be aware of this aberration and, by placing the patient to left-side up position, are able to expose the Calot’s triangle and possible accompanying anatomical anomalies and thus, perform a safe laparoscopic cholecystectomy without difficult surgical modifications.

Conflict of interest

None.

Funding

There is no source of funding.

Consent

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

Contributions

Mariolis and Zoulamoglou conceived of the study and participated in its coordination. Birbas and Konstantinou contributed to the acquisition of clinical data, its analysis and interpretation and to the preparation of images. Zarokosta and Piperos carried out the literature review. Flessas and Papapanagiotou contributed to the preparation of the manuscript. Zoulamoglou, Mariolis and Flessas contributed to the refinement of the case report. All authors have approved the final article.