In a patient with situs inversus who has a replaced hepatic artery, what pre‑operative imaging and intra‑operative techniques should be used to identify and preserve or reconstruct the artery during hepatobiliary surgery or liver transplantation?

Management of Replaced Hepatic Artery in Situs Inversus During Hepatobiliary Surgery

In patients with situs inversus totalis who have a replaced hepatic artery, comprehensive pre-operative cross-sectional imaging with CT or MR angiography is mandatory to map the mirror-image vascular anatomy and identify arterial variants, followed by intraoperative adaptation using reversed surgical approaches with the liver positioned in the left hepatic fossa. 1, 2, 3, 4

Pre-operative Imaging Requirements

Obtain high-resolution CT or MR angiography to accurately define hepatic arterial anatomy and identify vascular anomalies, which are extremely common in situs inversus totalis and can lead to devastating ischemic complications if injured intraoperatively. 1, 5, 3, 4

Specific Imaging Goals

• Map the complete hepatic arterial supply, as replaced or accessory hepatic arteries arising from the superior mesenteric artery are frequently present in situs inversus patients and may represent the sole arterial supply to portions of the liver. 5, 3, 4

• Identify the origin, course, and branching pattern of all hepatic arterial variants, including replaced right hepatic artery, replaced common hepatic artery, or accessory vessels, since these anomalies occur in the majority of situs inversus cases. 1, 4

• Assess portal venous anatomy and patency, as portal vein thrombosis or cavernous transformation represents an absolute contraindication to transplantation and significantly complicates resection. 1

• Evaluate biliary anatomy, as biliary malformations commonly coexist with vascular anomalies in situs inversus. 2, 3, 4

Intraoperative Techniques for Hepatobiliary Surgery

General Surgical Approach

Adapt to the mirror-image anatomy by reversing standard surgical techniques, recognizing that most surgeons are right-handed and will need to adjust instrument handling and positioning. 2, 4

• Position the surgical team on the opposite side of the operating table compared to standard procedures to accommodate the reversed anatomy. 2, 4

• Use advanced imaging studies intraoperatively to prevent misunderstanding of the visceral arrangement and avoid complications from associated cardiovascular and hepatobiliary malformations. 3, 4

Specific Techniques for Replaced Hepatic Artery Management

Perform meticulous perivascular dissection with early identification and preservation of all arterial variants, as replaced hepatic arteries may be the sole blood supply to liver segments and injury will result in hepatic necrosis. 1, 5, 4

• Identify replaced hepatic arteries before dividing any vascular structures, particularly when performing pancreaticoduodenectomy or major hepatectomy, as these vessels often course through the surgical field in unexpected locations. 1, 4

• Avoid injury to variant arterial anatomy (replaced right hepatic artery, replaced common hepatic artery, accessory arteries) by noting their presence and degree of tumor contact during surgical planning, as this directly affects resectability and reconstruction options. 1

• Consider intraoperative Doppler ultrasound to confirm arterial flow patterns and identify vessels in the reversed anatomical position. 3, 4

Liver Transplantation-Specific Techniques

For liver transplantation in situs inversus, flip the donor liver 180 degrees from right to left (facing backward) and position it in the left hepatic fossa with a reversed cavaplasty (anterior rather than posterior donor suprahepatic caval incision). 6

• Perform standard end-to-end anastomoses of the portal vein, hepatic artery, and bile duct after the 180-degree flip, which prevents torsion, kinking, and tension on anastomosed structures. 6

• This technique requires no special donor liver size restrictions and allows the liver to sit naturally in an anatomical position in the left-sided hepatic fossa. 6

• Alternative techniques include segment or reduced-size graft with rotation, modified piggy-back technique, side-to-side caval anastomosis, and vascular conduits, though these are more complex. 2

Critical Pitfalls and How to Avoid Them

The most catastrophic error is inadvertent injury to a replaced hepatic artery that represents the sole arterial supply to the liver, resulting in massive hepatic necrosis and death. 5, 4

• Never assume standard vascular anatomy in situs inversus patients—hepatic arterial anomalies are the rule rather than the exception. 5, 3, 4

• Recognize that replaced hepatic arteries from the superior mesenteric artery may be the entire arterial blood supply to the liver, making their preservation absolutely mandatory. 5

• Avoid performing hepatic artery embolization in situs inversus patients after cholecystectomy, as this carries extremely high risk of biliary and hepatic necrosis due to compromised collateral blood supply. 7

• Do not attempt major hepatobiliary surgery without detailed pre-operative vascular mapping, as intraoperative discovery of unexpected anatomy significantly increases morbidity and mortality. 1, 3, 4

Post-operative Monitoring

Monitor closely for hepatic ischemia, biliary complications, and vascular thrombosis, which occur more frequently in situs inversus patients due to the technical complexity of reversed anatomy. 6, 3

• Obtain early post-operative imaging (ultrasound with Doppler or CT angiography) to confirm hepatic arterial patency and adequate perfusion. 3

• Watch for bile leakage, which occurred in reported cases despite technically successful surgery, and manage with drainage. 3

• Serial liver function tests and hemoglobin measurements are essential to detect early complications. 8, 9