The Management and Challenges of Laparoscopic Cholecystectomy in Situs Inversus Abdominalis

Left-sided gallbladders are rare anatomical variations and a result of an abnormal embryological process. The most frequent cause for a sinistroposition gallbladder is the presence of situs inversus. We present a case of a 51-year-old male referred to the General Surgery consult due to cholelithiasis with a history of occasional post-prandial abdominal pain in the left hypochondrium and nausea associated with the ingestion of lipid-rich meals. The ultrasound revealed a gallbladder filled with calculous but without inflammatory signs or bile duct dilation, in the sinistroposition. Magnetic resonance imaging (MRI) confirmed and excluded further anatomic variations. The patient underwent a laparoscopic cholecystectomy due to symptomatic cholelithiasis without any complications and was discharged the following day. When faced with a patient with gallbladder/biliary duct disorders associated with situs inversus, one must have a high clinical index of suspicion to properly diagnose and the mental agility to adapt and further operate in a mirrored-positioned abdomen. In these situations the patient should always undergo a prior MRI to determine the correct anatomy of the biliary system and the surgeon should perform an intraoperative cholangiography if any other variations are suspected. The presence of situs inversus thus imposes a surgical and diagnostic challenge. Although rare the surgeon must be aware of this possibility.


Introduction
Left-sided gallbladders are rare anatomical variations and a result of an abnormal embryological process [1].The most frequent cause for a sinistroposition gallbladder is the presence of s itus inversus [2].
Situs inversus is a unique condition in which the orientation of asymmetric organs is a mirror image of normal anatomy.It may be partial, if only one of the abdominal/thoracic cavities is involved, or totalis with the lateral transposition of the organs on both compartments [3].
The association of this condition with other disorders make for a challenging diagnosis and management of abdominal pathology [4].

Case Presentation
We present a case of a 51-year-old male referred to the General Surgery consultation due to cholelithiasis with a history of nausea and occasional post-prandial abdominal pain in the left hypochondrium associated with the ingestion of lipid-rich meals.
There was no past medical or surgical history and no history of smoking or alcohol abuse.Physical examination revealed a painless abdomen with dull percussion of the left hypochondrium.No other significant aspects were found.
Laboratory results were within normal limits and pre-op X-ray showed no abnormalities (Figure 1).The ultrasound revealed a gallbladder, in the sinistroposition, filled with calculous but without inflammatory signs or bile duct dilation.
Magnetic resonance imaging (MRI) confirmed the usual subhepatic position of the gallbladder, but on the left hypochondrium, and ruled out other anatomic variations of the biliary ducts and vascular anatomy ( Figures 2,3,4).The patient underwent a laparoscopic cholecystectomy due to symptomatic cholelithiasis.With the patient in the supine position, the insufflation of the abdomen was achieved to 12 mmHg with the Veress needle after the umbilical incision.The American technique was used (trocar placement: 10 mm -umbilical; 10 mm -subxiphoid, medial subcostal and lateral subcostal, both on the left side) and a 5 mm optic was inserted in the umbilical port (Figure 5).Laparoscopic survey was performed, confirming situs inversus abdominalis (Figure 6).The gallbladder was excised from its plate and removed in an endobag through the umbilical port (Figure 8).

FIGURE 8: Dissection of the cystic plate
There were no intraoperative complications.The patient was discharged on the following day with an uneventful hospital stay.The pathology report confirmed the presence of chronic cholecystitis which was compatible with our diagnostic hypothesis.Thirty days after the surgery, the main complaints were resolved and the patient was discharged from the General Surgery consultation, confirming the diagnosis.

Discussion
Situs inversus has an incidence of 1:5,000 to 1:10,000 with a slight male predominance and is the most frequent cause of sinistroposition gallbladders [5].Left-sided gallbladders are not often identified preoperatively and, because they are associated with biliary and vascular anomalies, the surgeon must be familiar with the variations that he might encounter [1].In a multicenter study, the prevalence of sinistroposition gallbladders was 0.3% in laparoscopic cholecystectomies [6].The prevalence of an anomalous bifurcation of the cystic duct from the left hepatic duct in this condition is 5.6% and 14.3% [5].With the high prevalence of gallstone disease, it is remarkable that less than 40 cholecystectomies in patients with situs inversus were reported in the literature during the pre-laparoscopic era [7].
Modern-day MRI has made imaging of the biliary tract faster, with excellent anatomic reproduction of the biliary ducts.MRI/MR-cholangiopancreatography (MRCP) has now become the first-line imaging method for the investigation of this duct system [8].Intra-operative anatomy that does not appear normal should suggest the possibility of biliary malformations and dissection should proceed with extreme caution [9].This fact highlights the necessity to achieve a critical view of safety before cutting or dividing tubular structures [5,6].
Whenever there is a poorly defined anatomy, intraoperative cholangiography ought to be performed to detect associated anomalies of the biliary tree [9].Selective use of intraoperative cholangiography and meticulous dissection can aid in a safe resection [10].The choice of Palmer's point to achieve pneumoperitoneum might not be the best option when faced with a mirrored image of the abdominal organs.The success of a minimally invasive cholecystectomy may not be achievable since there is a wide spectrum of possible anomalies associated with left-sided gallbladders [11,12].As a last resource, the conversion to laparotomy should be taken into consideration before any avoidable complications occur [5].

Conclusions
When faced with a patient with gallbladder/biliary duct disorders associated with situs inversus, one must have a high clinical index of suspicion to properly diagnose and the mental agility to adapt and further operate in a mirrored-positioned abdomen.
In this situation, the patient should always undergo a prior MRI to determine the correct anatomy of the biliary system.
The presence of situs inversus thus imposes a surgical and diagnostic challenge and, although rare, the surgeon must be aware of this possibility.

FIGURE 3 :
FIGURE 3: MRI, T2 weighted, coronal plane Grey arrow: Liver in the sinistroposition Red arrow: Subhepatic gallbladder, on the left side of the abdomen

FIGURE 5 :
FIGURE 5: Trocar placement Inverted American technique trocar placement Image credit: Authors

FIGURE 6 :
FIGURE 6: The mirrored image of the gallbladder Grey arrow: Falciform ligament Green arrow: Gallbladder