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Injuries to the liver and biliary tract
Introduction
The majority of hepatobiliary injuries are managed nonoperatively, supported by tenets of patient selection, appropriately timed adjunct interventions, and careful monitoring. The liver is a well-vascularized solid organ (see Chapter 5 ), making hemorrhage a common cause of mortality in severe trauma. Therefore, in hemodynamically unstable patients or clinically deteriorating patients, timely surgical intervention for hemorrhage control is critical. Hepatobiliary injuries associated with blunt and penetrating mechanisms include a wide range of injury patterns: deep parenchymal disruptions, hemorrhage from veins and arteries, major juxtahepatic venous injuries, and extrahepatic and intrahepatic biliary injuries. This chapter presents the current approach to hepatobiliary injuries from the perspective of a trauma surgeon, recognizing that treatment of complex hepatobiliary trauma requires a multidisciplinary approach. The principles and techniques of both nonoperative and operative management of hepatic and extrahepatic biliary tree trauma are reviewed with an emphasis on the fundamental differences between emergency and elective hepatobiliary operations.
Evolution of management of hepatobiliary trauma
The evolution of the management of hepatic trauma during the last century reflects the progression of the discipline of trauma surgery overall. , The approach to hepatic trauma in the early 1900s was largely expectant management, which for severe liver injuries was uniformly fatal. Controlling hepatic inflow via manual compression of the hepatoduodenal ligament was first described by Dr. James Hogarth Pringle in 1908 for hepatic hemorrhage ; this technique has become known as the Pringle maneuver. Although less often appreciated, Dr. Pringle also described packing around the liver and kidney to stop solid organ hemorrhage in the same series of patients. Halsted modified the technique further by placing rubber sheets between the packs and the liver to protect the parenchyma from adhering to the packs (see Introduction).
Decades later, World War II and post-war civilian trauma experiences stimulated development and use of more aggressive surgical strategies, including formal resection, debridement of devitalized liver, selective hepatic artery ligation, and perihepatic drainage. These approaches emphasized operative treatment of hepatic trauma by way of hemorrhage control. Several series in the 1960s and 1970s reported successful application of formal anatomic resections with portal triad control. Selective hepatic artery ligation was popularized during this era as a way to control initial massive hemorrhage and prevent delayed bleeding, , although associated high infection rates raised concern with this technique. , Direct repair of injuries to perihepatic veins was addressed by the development of the atriocaval shunt, but mortality from such devastating injuries remained high. ,
Perihepatic packing fell out of favor during this era of early aggressive surgical interventions; however, it was repopularized in the 1990s with recognition of the importance of damage control surgical and resuscitation techniques. The term “damage control” was first defined by Dr. Michael Rotondo as a way to rapidly control hemorrhage and contamination, allowing for resuscitation and deferment of definitive reconstruction until physiologic optimization. Before this, perihepatic packing was only used in limited series to control hemorrhage when definitive operative interventions failed. A landmark study by Lucas and Ledgerwood described perihepatic packing in devastating juxtahepatic venous injury, and Calne and colleagues described packing to temporize massive liver hemorrhage for safe transfer to referral centers. In a sentinel paper from Feliciano and colleagues, packing was advocated as a rescue maneuver to tamponade diffuse coagulopathic liver bleeding in patients otherwise deemed nonsurvivable. A series of reports followed, suggesting a “paradigm shift” away from aggressive operative interventions and resections for hepatic trauma. , In aggregate, the realization that major hepatic resection in trauma is ill-advised developed out of an understanding that severe trauma and extensive surgery lead to irreversible physiologic insult, hypothermia, coagulopathy, and death.
Another dramatic shift in treatment of hepatic trauma ensued with the introduction of computed tomography (CT) and alternative modes of hemorrhage control by angiography and endovascular embolization (see Chapters 21 , 94A , 115 , and 116 ). These shifts supported an approach of nonoperative management (NOM) with selective operative interventions. It was the advancement of NOM of solid organ injuries in hemodynamically stable children that encouraged a similar strategy in adults. In 1990, Knudson and colleagues reported on 52 patients with major hepatic injuries successfully managed nonoperatively with careful surveillance. Several reports subsequently demonstrated the safety and efficacy of NOM of hepatic injuries in adults with both blunt and penetrating mechanisms. , , , However, these shifts highlighted the importance of patient selection for the success of NOM of hepatic trauma, and for interventional techniques to manage the sequelae of major hepatic trauma. Reliance on adjuncts, including angiographic embolization of hepatic arterial bleeding, endoscopic biliary decompression, delayed laparoscopic drainage, and percutaneous debridement and drainage of liver necrosis and abscess (see Chapters 21 , 30 ) added to the armamentarium for treatment of hepatic trauma.
Anatomy and classification of hepatic trauma
From a trauma surgeon’s perspective, the surgical anatomy (see Chapter 2 ) has to do with the anatomic location of injury and the mechanism of injury and hemodynamic status of the patient. The American Association for the Surgery of Trauma (AAST) liver injury scale offers an anatomic classification for radiologic imaging or for direct visualization during exploration ( Table 113.1 and Fig. 113.1 ). Typically, AAST grade I to II liver injuries are considered mild, grade III moderate, and grade IV to V severe. Patients with grade VI hepatic avulsion injuries rarely survive to undergo further therapy. Based on the AAST classification, the World Society of Emergency Surgery (WSES) 2020 guidelines added the patient’s hemodynamic status to the injury classification ( Table 113.2 ).
TABLE 113.1
American Association for the Surgery of Trauma Liver Injury Classification (1994 Revision)
| GRADE a | INJURY TYPE | INJURY DESCRIPTION |
|---|---|---|
| I | Hematoma | Subcapsular, <10% surface area |
| Laceration | Capsular tear, <1 cm parenchymal depth | |
| II | Hematoma |
|
| Laceration | 1-3 cm parenchymal depth, <10 cm in length | |
| III | Hematoma |
|
| Laceration | >3 cm parenchymal depth | |
| IV | Laceration | Parenchymal disruption involving 25%-75% of hepatic lobe or 1-3 Couinaud segments within a single lobe |
| V | Laceration | Parenchymal disruption involving >75% of hepatic lobe or >3 Couinaud segments within a single lobe |
| Vascular | Juxtahepatic venous injuries; i.e., retrohepatic vena cava/central major hepatic veins | |
| VI | Vascular | Hepatic avulsion |
TABLE 113.2
World Society of Emergency Surgery Liver Injury Classification (2020)
| WSES GRADE | AAST | HEMODYNAMIC | |
|---|---|---|---|
| Minor | WSES grade I | I-II | Stable |
| Moderate | WSES grade II | III | Stable |
| Severe | WSES grade III WSES grade IV |
IV-V I-VI |
Stable Unstable |
AAST, American Association for the Surgery of Trauma; WSES, World Society of Emergency Surgery Liver Injury.
Diagnosis of hepatic trauma
Abdominal ultrasound, as part of the focused assessment of sonography in trauma (FAST) exam, was validated by Dr. Grace Rozycki in the 1990s as an alternative to identifying hemoperitoneum as a noninvasive alternative to diagnostic peritoneal lavage (DPL). This was of value because although DPL was sensitive, it resulted in many negative or nontherapeutic laparotomies, including in the setting of low-grade hepatic injuries that did not warrant an operation. Point-of-care FAST is used to rapidly triage the need for emergent laparotomy when performed in hemodynamically unstable patients with blunt abdominal injuries. Positive findings, however, cannot determine the source of blood or grade of injuries.
CT scan has become the gold standard for diagnosing solid organ injury in hemodynamically stable patients. Intravenous (IV) contrast–enhanced CT scan of the abdomen gives a rapid assessment of liver injury grade, other solid organ injuries, and degree of hemoperitoneum (see Chapter 14 ). Further, it can provide evidence of concurrent bowel injury, and the trajectory of penetrating wounds that can help tailor further interventions.
Nonoperative management of hepatic trauma
In this section, we will review the core principles of NOM of hepatic trauma ( Box 113.1 ), highlighting subtle differences between blunt and penetrating injuries. Most patients with liver injuries, regardless of mechanism, who are hemodynamically stable and without diffuse peritonitis or signs of concurrent bowel injury can be safely observed and treated nonoperatively. , , Recent series of severe liver injuries (AAST 4 or 5) demonstrate that 90% to 93% of patients who underwent NOM had successful management of complex hepatic trauma, with variable adjunctive early angiographic embolization. , ,
BOX 113.1
NOM, Nonoperative management.
Core Principles of Nonoperative Management of Hepatic Trauma
- 1.
NOM is recommended in hemodynamically stable patients with blunt and penetrating hepatic trauma regardless of grade.
- 2.
NOM is considered only after excluding concurrent intestinal injuries.
- 3.
NOM is limited to environments where continuous monitoring, serial clinical evaluations, transfusion, angiographic embolization, and an operating room for urgent laparotomy are available.
- 4.
Patients with hemodynamic instability and peritonitis require urgent operative intervention for hemorrhage control.
- 5.
Intravenous contrast-enhanced computed tomographic scan of the abdomen is the diagnostic modality of choice for evaluating hepatic trauma, and repeat imaging should be guided by the patient’s clinical status.
- 6.
Adjunctive therapies, such as angiographic embolization, percutaneous drainage, endoscopy/endoscopic retrograde cholangiopancreatography, and laparoscopy are important adjuncts to NOM.
NOM of hepatic trauma can help avoid unnecessary laparotomies and associated risks, including anesthesia-associated complications, iatrogenic injury, longer recovery and hospital stays, and longer-term adhesive small bowel obstruction and incisional hernias. However, the advantages of NOM go beyond simply avoiding an operation. Richardson and colleagues suggested that hepatic-specific trauma mortality improved by adapting the NOM strategy. In fact, although nonoperative observational approaches for liver injuries increased over the past 25 years, mortality drastically decreased.
However, with this, the concept of patient selection became paramount in successful NOM of hepatic trauma. Patients considered for NOM must be hemodynamically stable without signs of concurrent intestinal injuries, regardless of the grade of injury or patient age. Hemodynamically unstable patients, or those with peritonitis, should be taken urgently for laparotomy. Patients undergoing NOM should also be considered for nonsurgical adjunctive therapies, including angiographic embolization, percutaneous drainage, and endoscopy for biliary drainage (see Chapters 16 , 20 , 21 , 30 , 31 , and 94A ). Delayed laparoscopy for bile leak or hematoma may also be considered.
Nonoperative management of blunt hepatic trauma
The overall success rate of NOM in blunt hepatic trauma is high. , , Higher grades of injury carry a greater risk of failure of NOM. Patients with minor to moderate hepatic injuries (AAST 1–3 or WSES 1–2) have success rates near 100%, , and those with severe injuries (AAST 4–5, WSES 3) have success rates of 83% to 94%, , aided by early hepatic angiographic embolization (see Chapters 21 , 94A , 115 , and 116 ).
NOM is centered on early CT evaluation of liver injuries, and heightened vigilance with repeated clinical reassessment for early signs of active hemorrhage. Therefore, for moderate to severe injuries, patients typically require close hemodynamic monitoring and frequent hemoglobin checks in the intensive care unit. As it stands, there is insufficient data to suggest a standard of care for duration of monitoring, frequency of laboratory checks, time to enteric diet initiation, duration of activity restriction, and safe time for chemical prophylaxis for venous thromboembolism. , However, frequent abdominal examinations are paramount during the observational period, and any clinical deterioration, particularly with signs and symptoms of active hemorrhage, necessitates reassessment and consideration of angiogram or urgent operation. Therefore consensus supports that NOM should only be considered in environments that allow continuous monitoring, serial clinical evaluations, transfusion, and have access to angiographic embolization adjuncts and an operating room with trained surgeons available. ,
One must also be on alert for missed injuries in patients undergoing NOM for hepatic trauma. Severe solid organ injury is associated with concomitant visceral injury, and failure of timely recognition of intestinal injury can be catastrophic. Although CT enables earlier diagnosis of visceral injury, it is notoriously not sensitive for hollow viscous injury, missing up to 20% of intestinal perforations.
Nonoperative management of penetrating hepatic trauma
As with blunt hepatic trauma, hemodynamic stability and absence of other operative abdominal injuries are requirements of successful NOM of penetrating injuries to the liver. Historically, mandatory laparotomy was the predominant management strategy for all penetrating wounds of the abdomen. Derived from the experience of blunt hepatic trauma, NOM is becoming an acceptable management option in certain penetrating injuries as well. However, as with blunt trauma, patient selection is paramount, especially in high-energy penetrating mechanisms. The majority of abdominal gunshot wounds (GSWs) still require an immediate exploration, in up to 60% to 80% in modern series. , Approximately 7% to 15% of patients undergoing NOM for abdominal GSW require a delayed laparotomy. , Despite this, successful NOM has been reported with both GSW and stab wounds to the liver. , ,
In the absence of an immediate indication for surgery, a CT scan is extremely helpful for visualizing the projectile trajectory, determining the degree of liver injury, and diagnosing associated abdominal injuries, including hollow viscous and other solid organ (kidney, spleen, or pancreas) injuries. , , Physical examination is important, as any clinical changes may prompt an urgent operation, angiography, or further imaging for diagnosis and management of delayed infectious or biliary complications. For this reason, as for blunt hepatic trauma, NOM of penetrating hepatic trauma should be performed only in resource-rich environments.
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