Chapter 27 – Liver and Biliary Tract Injuries




Abstract






  • The liver is tethered by the following ligaments:

    • The falciform ligament attaches the liver anteriorly to the diaphragm and the anterior abdominal wall above the umbilicus.
    • The coronary ligaments extend laterally to attach the liver to the diaphragm. Beginning at the suprahepatic inferior vena cava (IVC), the lateral extensions of the coronary ligaments form the triangular ligaments (right and left), which are also attached to the diaphragm.

  • The anatomical division of the liver into the eight classic Couinaud segments has no practical application in traumatic liver resection, where the resection planes are nonanatomical and are dictated by the extent of injury. However, the external anatomical landmarks may be useful in planning operative maneuvers.

    • The plane between the center of the gallbladder and IVC runs along the middle hepatic vein, and serves as the line of division between the right and left lobes.
    • The left lobe is divided by the falciform ligament into the medial and lateral segments.
    • Dissection along the falciform ligament should be performed carefully, so as to avoid injury to the portal venous supply to the medial segment of the left lobe inferiorly and the hepatic veins superiorly.

  • The retrohepatic IVC is approximately 8–10 cm long and is partially embedded into the liver parenchyma. In some cases, the IVC is completely encircled by the liver, further complicating exposure and repair.
  • There are three major hepatic veins (right, middle, and left), as well as multiple accessory veins. The first 1–2 cm of the major hepatic veins are extra-hepatic, with the remaining 8–10 cm intra-hepatic. In approximately 70% of patients, the middle hepatic vein joins the left hepatic vein before entering the IVC.
  • The common hepatic artery originates from the celiac artery. It is responsible for approximately 30% of the hepatic blood flow, but supplies 50% of the hepatic oxygenation. It branches into the left and right hepatic arteries at the liver hilum in the majority of patients. In a common anatomical variant, the right hepatic artery may arise from the superior mesenteric artery. Less frequently, the entire arterial supply may arise from the superior mesenteric artery. Alternatively, the left hepatic artery may arise from the left gastric artery in 15–20% of patients.
  • The portal vein provides approximately 70% of hepatic blood flow, and 50% of the hepatic oxygenation. It is formed by the confluence of the superior mesenteric vein and the splenic vein behind the head of the pancreas. The portal vein divides into right and left extrahepatic branches at the level of the liver parenchyma.
  • The porta hepatis contains the hepatic artery (medial), common bile duct (lateral), and portal vein (posterior, between the common bile duct and the hepatic artery).
  • The right hepatic duct is easier to expose after removal of the gallbladder.
  • The left hepatic duct, the left hepatic artery, and the left portal vein branch enter the undersurface of the liver near the falciform ligament.





Chapter 27 Liver and Biliary Tract Injuries


Kenji Inaba , Zachary D. Warriner , and Kelly Vogt



Surgical Anatomy




  • The liver is tethered by the following ligaments:




    • The falciform ligament attaches the liver anteriorly to the diaphragm and the anterior abdominal wall above the umbilicus.



    • The coronary ligaments extend laterally to attach the liver to the diaphragm. Beginning at the suprahepatic inferior vena cava (IVC), the lateral extensions of the coronary ligaments form the triangular ligaments (right and left), which are also attached to the diaphragm.




  • The anatomical division of the liver into the eight classic Couinaud segments has no practical application in traumatic liver resection, where the resection planes are nonanatomical and are dictated by the extent of injury. However, the external anatomical landmarks may be useful in planning operative maneuvers.




    • The plane between the center of the gallbladder and IVC runs along the middle hepatic vein, and serves as the line of division between the right and left lobes.



    • The left lobe is divided by the falciform ligament into the medial and lateral segments.



    • Dissection along the falciform ligament should be performed carefully, so as to avoid injury to the portal venous supply to the medial segment of the left lobe inferiorly and the hepatic veins superiorly.


      Figure 27.1



      (a) Surgical anatomy of the liver. The plane between the gallbladder and inferior vena cava (IVC) (interrupted line) runs along the middle hepatic vein. Dissection along the falciform ligament should be done carefully, so as to avoid injury to the portal venous supply to the medial segment of the left lobe inferiorly and the hepatic veins superiorly.





      (b) The extrahepatic portions of the three major hepatic veins are visible after division of the falciform and right coronary ligaments, providing venous drainage into the suprahepatic IVC.





  • The retrohepatic IVC is approximately 8–10 cm long and is partially embedded into the liver parenchyma. In some cases, the IVC is completely encircled by the liver, further complicating exposure and repair.



  • There are three major hepatic veins (right, middle, and left), as well as multiple accessory veins. The first 1–2 cm of the major hepatic veins are extra-hepatic, with the remaining 8–10 cm intra-hepatic. In approximately 70% of patients, the middle hepatic vein joins the left hepatic vein before entering the IVC.



  • The common hepatic artery originates from the celiac artery. It is responsible for approximately 30% of the hepatic blood flow, but supplies 50% of the hepatic oxygenation. It branches into the left and right hepatic arteries at the liver hilum in the majority of patients. In a common anatomical variant, the right hepatic artery may arise from the superior mesenteric artery. Less frequently, the entire arterial supply may arise from the superior mesenteric artery. Alternatively, the left hepatic artery may arise from the left gastric artery in 15–20% of patients.



  • The portal vein provides approximately 70% of hepatic blood flow, and 50% of the hepatic oxygenation. It is formed by the confluence of the superior mesenteric vein and the splenic vein behind the head of the pancreas. The portal vein divides into right and left extrahepatic branches at the level of the liver parenchyma.



  • The porta hepatis contains the hepatic artery (medial), common bile duct (lateral), and portal vein (posterior, between the common bile duct and the hepatic artery).



  • The right hepatic duct is easier to expose after removal of the gallbladder.



  • The left hepatic duct, the left hepatic artery, and the left portal vein branch enter the undersurface of the liver near the falciform ligament.


Figure 27.2



(a) The porta hepatis contains the hepatic artery (medial), common bile duct (lateral) and portal vein (posterior).





(b) The porta hepatis contains the hepatic artery (medial), common bile duct (lateral) and portal vein (posterior).



General Principles




  • The liver is the most commonly injured intra-abdominal solid organ.



  • Most injuries to the liver do not require operative intervention.



  • Angioembolization is an effective adjunct to the nonoperative management of high-grade liver injuries, especially in patients with evidence of active extravasation on contrast-enhanced CT scan. After damage control packing of complex liver injuries operatively, angioembolization may be an effective adjunct.



  • Damage control procedures have revolutionized the management of complex liver injuries and, in the appropriate cases, it should be considered early. Packing is the mainstay of damage control for the liver.



  • A contained stable retrohepatic hematoma should not be opened. If the hematoma is expanding or leaking, and it is possible to control with packing alone, this technique should be the operative treatment of choice. The operation should then be terminated and the patient brought to the ICU for ongoing resuscitation. Angioembolization may be of use, especially if there is associated parenchymal damage that was packed. The patient can return to the operating room for pack removal after complete physiological stabilization.



  • Adequate mobilization of the liver, by division of the falciform and coronary ligaments, is essential in the management of posterolateral injuries.



  • Retrohepatic IVC or hepatic vein injury should be suspected if bleeding from the posterior liver worsens during anterior retraction of the liver.



  • In approximately 80–85% of patients undergoing operation, the liver injury can be managed by relatively simple surgical techniques, such as application of local hemostatic agents, electro-coagulation, superficial suturing, or drainage. The remaining 15–20% of cases require more complex surgical techniques.



Special Surgical Instruments




  • A hybrid operating room suite with angioembolization capability is highly desirable.



  • A standard trauma laparotomy tray, which includes vascular instruments, should be prepared. A sternotomy set should be available in case a median sternotomy is needed for improved exposure of the retrohepatic IVC.



  • A fixed self-retaining abdominal retractor, such as an Omni-flex, Bookwalter, or Gomez.



  • An electrothermal bipolar vessel sealing system (LigaSure device) is desirable.



  • A surgical headlight allows improved visualization of right-sided and posterior injuries.



Positioning




  • Supine position, with upper extremities abducted to 90°.



  • Skin antiseptic preparation should include the chest, abdomen, and groin.



  • Use upper and lower body warming devices.



Incisions


Sep 4, 2020 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 27 – Liver and Biliary Tract Injuries
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