Overview
Definition:
Atypical hepatectomy refers to any liver resection that does not conform to standard anatomical segments (e.g., right/left hepatectomy, bisegmentectomy)
It is employed in specific scenarios of liver trauma, particularly for complex lacerations where standard wedge resection or anatomical resection is not feasible or optimal for achieving hemostasis and managing devascularized or injured liver parenchyma.
Epidemiology:
Liver lacerations are common injuries in blunt and penetrating abdominal trauma, occurring in 10-20% of patients with abdominal trauma
The need for atypical hepatectomy arises in approximately 5-10% of significant liver injuries, often associated with high-grade injuries (grade IV-V according to the American Association for the Surgery of Trauma - AST classification).
Clinical Significance:
Effective management of liver lacerations is crucial to prevent life-threatening hemorrhage and subsequent complications like hemobilia, biliary fistulas, abscesses, and liver failure
Atypical hepatectomy, when indicated, allows for precise debridement of necrotic tissue, control of bleeding vessels, and preservation of functional liver mass, thereby improving patient survival and reducing morbidity.
Clinical Presentation
Symptoms:
Hemodynamic instability (hypotension, tachycardia)
Abdominal pain, often severe and diffuse
Abdominal distension
Referred shoulder pain (Kehr's sign) in diaphragmatic irritation
Nausea and vomiting
Signs of hypovolemic shock.
Signs:
Generalized tenderness and guarding of the abdomen
Rebound tenderness
Abdominal distension
Possible bruising or seatbelt sign over the abdomen
Hypotension, tachycardia, tachypnea
Pallor and diaphoresis
Decreased urine output.
Diagnostic Criteria:
Diagnosis is primarily based on clinical suspicion in the setting of trauma and confirmed by imaging
Hemodynamic stability or instability guides immediate management
High-grade liver injuries (AST grade IV-V) involving major vessels or parenchyma devascularization often warrant consideration for surgical intervention, including atypical resection.
Diagnostic Approach
History Taking:
Mechanism of injury (blunt vs
penetrating)
Associated injuries to other organs
Previous abdominal surgeries or liver disease
Medications, especially anticoagulants or antiplatelets
Allergies.
Physical Examination:
Assess airway, breathing, circulation (ABCs)
Detailed abdominal examination: inspection for wounds, ecchymosis
palpation for tenderness, guarding, rigidity, masses
auscultation for bowel sounds
Assess for signs of shock and distributive injuries.
Investigations:
FAST (Focused Assessment with Sonography for Trauma) examination: identifies free fluid in the abdomen, suggestive of hemorrhage
CT scan of the abdomen and pelvis with intravenous contrast: gold standard for grading liver injuries, assessing extent, identifying associated injuries, and evaluating vascular involvement
Hemoglobin, hematocrit, coagulation profile (PT/INR, PTT), platelet count, liver function tests (LFTs), electrolytes, renal function tests
Blood type and crossmatch.
Differential Diagnosis:
Other intra-abdominal bleeding sources (spleen, kidneys, mesentery)
Peritoneal hematoma
Diaphragmatic injury
Gastric or intestinal perforation.
Management
Initial Management:
Rapid resuscitation with intravenous fluids and blood products
Airway management and oxygenation
Hemodynamic monitoring
Immediate surgical consultation for unstable patients or those with high-grade injuries
Non-operative management (NOM) for hemodynamically stable patients with lower-grade injuries, involving close monitoring and supportive care.
Medical Management:
Fluid resuscitation guided by hemodynamic parameters
Blood product transfusion protocols (e.g., balanced transfusion ratios of RBCs, FFP, platelets)
Analgesia
Proton pump inhibitors for stress ulcer prophylaxis
Antibiotics may be considered in penetrating injuries or if infection is suspected.
Surgical Management:
Indications for surgery include hemodynamic instability not responding to resuscitation, expanding hemoperitoneum on imaging, clear evidence of ongoing hemorrhage, or injuries incompatible with NOM
Atypical hepatectomy is considered when: the laceration involves major hepatic veins or the retrohepatic vena cava
there is extensive parenchymal devascularization or crushing injury
standard wedge resection would result in significant bile leak or unmanageable bleeding
the injury extends deep into the liver hilum
Techniques may involve debridement of non-viable tissue, ligation of bleeding vessels (intrahepatic or caval), use of hemostatic agents, packing, and suprahepatic caval shunting if needed
May require exploration of the hepatic pedicle and porta hepatis
Consideration of damage control surgery principles.
Supportive Care:
Continuous hemodynamic monitoring
Serial abdominal examinations
Serial hematocrit and coagulation monitoring
Mechanical ventilation if required
Nutritional support: early enteral feeding should be initiated as tolerated once bowel function returns
Intensive care unit (ICU) monitoring post-operatively.
Complications
Early Complications:
Hemorrhage (ongoing bleeding)
Biliary leakage or fistula
Bile peritonitis
Hepatic abscess formation
Coagulopathy
Acute kidney injury
Respiratory distress syndrome.
Late Complications:
Post-traumatic hemobilia
Chronic biliary strictures
Hepatic insufficiency or failure
Incisional hernia
Adhesions.
Prevention Strategies:
Adequate intraoperative hemostasis
Careful debridement of necrotic tissue
Secure biliary reconstruction
Judicious use of packing and drains
Early recognition and management of coagulopathy
Prophylactic antibiotics where indicated
Aggressive fluid and blood resuscitation
Close post-operative monitoring.
Prognosis
Factors Affecting Prognosis:
Severity of liver injury (AST grade)
Degree of hemodynamic instability
Presence of associated injuries
Promptness and adequacy of resuscitation and surgical intervention
Patient's comorbidities
Development of complications.
Outcomes:
For hemodynamically stable patients managed non-operatively, outcomes are generally good with high success rates
For patients requiring surgery, the mortality rate is higher and directly correlates with the injury severity and hemodynamic status
Successful atypical hepatectomy can preserve liver function and improve survival in complex cases.
Follow Up:
Patients who undergo operative management require close post-operative follow-up
This includes monitoring for complications such as infection, bleeding, and biliary issues
Serial imaging may be required
Long-term follow-up may be necessary for patients with significant liver dysfunction or specific sequelae like hemobilia or strictures.
Key Points
Exam Focus:
Atypical hepatectomy indications in high-grade liver trauma
Principles of damage control surgery in liver injuries
Management of hemodynamic instability
Role of CT scan in grading and management decisions
Management of bleeding from hepatic veins and vena cava.
Clinical Pearls:
Always consider mechanism of injury and hemodynamic status
The "no-reflow" phenomenon after major vascular injury to the liver is a key consideration for resection
Intraoperative ultrasound can be invaluable for assessing vascular supply and extent of injury
Damage control packing should be removed electively within 48-72 hours
Consider posterior approach for difficult retrohepatic vena cava injuries.
Common Mistakes:
Delaying surgical intervention in unstable patients
Inadequate resuscitation prior to surgery
Incomplete debridement of devitalized tissue
Failure to identify and control all sources of bleeding, especially from retrohepatic veins
Insufficient management of biliary leak
Over-resection leading to hepatic insufficiency.