Acute cholecystitis in a patient with heterotaxic anatomy and partial situs inversus

Abstract

It is well recognised that situs inversus totalis can make surgery challenging. However, partial situs inversus with heterotaxic anatomy has rarely been reported. While routine, the presence of symptomatic gallstones or cholecystitis can lead to a complex and difficult operation for such patients. We present the case of a patient with heterotaxic anatomy and partial situs inversus with acute cholecystitis.

Introduction

Situs inversus totalis is a rare congenital condition that results in transpositioning of the anatomy of the thorax and abdomen in the vertical plane. The condition is an autosomal recessive disorder. It has, however, also been noted to occur in twins as an X-linked condition.¹ The reported incidence varies between 1:10,000 and 1:20,000 births.²

It is well recognised that situs inversus totalis can make surgery challenging.³ Partial inversus with heterotaxic anatomy has rarely been reported. Although routine, symptomatic gallstones or cholecystitis can result in a complex and difficult operation for such patients. We describe the case of a patient with heterotaxic anatomy and partial situs inversus with acute cholecystitis.

Case history

A 57-year-old woman presented with epigastric pain of 48 hours’ duration. The pain was described as constant but peaking in severity in numerous waves throughout the day. She reported non-bilious vomiting and a reduced appetite. She did not report any shortness of breath and was afebrile. On examination, the abdomen was soft but tender in the epigastric region. The patient was tachycardic at rest (150bpm). All other observations were unremarkable. Intravenous fluids were started along with analgesia, an antiemetic and a proton pump inhibitor (omeprazole).

Computed tomography demonstrated a number of developmental abnormalities. The two lobes of the liver were symmetrical in nature and extended beyond the midclavicular line. On the left, the portal vein was located superficially beneath the abdominal wall. The proximal small bowel was non-rotated so that the bulk was positioned on the right side of the abdomen with the duodenum on the left. Polysplenia was noted with numerous splenules. The gallbladder was positioned to the left of the midline and almost completely intrahepatic. The superior mesenteric vasculature was inverted in orientation. The superior mesenteric vein was noted to drain anteriorly into the left portal vein, which drained medially into the right side through the left lobe. The pancreatic head appeared globular in nature and hypogenesis of the pancreatic tail was also observed.

The patient underwent ultrasonography, which confirmed the unusual vasculature of the liver, and a grossly thickened and irregular gallbladder, in keeping with advanced acute cholecystitis. Magnetic resonance cholangiopancreatography further showed an anomalous biliary duct, which joined the common hepatic duct, close to the cystic duct insertion.

Discussion

During embryogenesis, the endoderm forms a primitive gut tube that divides the abdomen into a foregut, midgut and hindgut. The liver develops from the hepatic diverticulum, which arises from the ventral foregut. The posterior hepatic diverticulum forms the gallbladder and intrahepatic biliary tree. The liver undergoes rapid growth and positions itself primarily on the right side while the stomach positions itself primarily from the midline to the left. The developing foregut contains the liver, pancreas, gallbladder, lungs and stomach,^4,5 many of which were malpositioned in this patient.

The loss of arrangement of organs in the thoracic or abdominal cavity is known as situs ambiguous or heterotaxia. Several genes including the transforming growth factor pathway, which controls the early development of left and right distribution of organs during fetal development, have been implicated. Studies have also alluded to the vital role of Hox genes, the morphogen sonic hedgehog and transcription factors (SOX2 and SOX3) during development, which (if effected) can result in malpositioning of organs and developmental conditions such as oesophageal stenosis and tracheoesophageal fistulas.^6,7

In this case, many variants of normal anatomy were identified. Of note was the fact that the portal vein was located in an unusual and surgically challenging position: just beneath the abdominal wall. Furthermore, the gallbladder was positioned in the epigastric region within the liver, making it difficult to approach surgically.

Owing to her complex anatomy, the patient underwent percutaneous drainage with cholecystostomy. The drain was left in situ for three months. One week after removal of the drain, she re-presented with a gallbladder collection and localised intrahepatic extension. In order to achieve sepsis control, a further percutaneous drain was inserted with an angiography catheter under ultrasonography guidance via the transhepatic tract into the hepatic abscess, not into the gallbladder. The patient subsequently recovered but presented again a month later with further symptoms of acute cholecystitis. Following multidisciplinary team discussion, a decision was made to attempt surgery because of the history of recurrent cholecystitis.

Consequently, in November 2018 the patient was sent to a specialist hepatobiliary unit. On examination there, her symptoms had markedly improved. Given the nature of the complications that could occur if surgery was undertaken, a lengthy conversation was had with her, resulting in the decision to delay the procedure and continue with conservative methods.

The patient was operated on in December 2018. A laparoscopic approach was chosen and recent computed tomography findings were reviewed in detail before the operation. The portal vein was carefully avoided by opting for an entry site just superior to the usual periumbilical incision. Major vessels and organs were circumvented, and the gallbladder was removed with no complications. The patient has since improved dramatically and has now been discharged back to the care of her general practitioner.

Conclusions

The patient described in this case report was admitted with signs and symptoms of acute cholecystitis. Further investigation revealed peculiar anatomy, meaning routine laparoscopic cholecystectomy was deemed difficult. This was a case of a rare variant of situs inversus with heterotaxic anatomy. Only few similar cases have been reported in the literature.

In patients known to have unusual anatomy, it is crucial to have sufficient imaging prior to any procedure (surgical or radiological). A multidisciplinary approach, preoperative management and careful intraoperative exploration can ensure the surgeon is well equipped to deal with cases of partial situs inversus and heterotaxic variants.

Figure 1.

Computed tomography showing the midline position of the liver and polysplenia

Figure 2.

Computed tomography showing the anterior position of the portal vein

Figure 3.

Computed tomography showing the position of the proximal small bowel