Overview

Definition:
-Non-anatomical resection, often termed a wedge resection or limited resection, for liver lacerations involves removing the damaged liver tissue without strict adherence to anatomical liver segments
-This approach is primarily employed in managing blunt or penetrating hepatic trauma when significant hemorrhage or devitalized parenchyma is present, but complete anatomical hepatectomy is deemed too extensive or technically challenging.
Epidemiology:
-Liver lacerations are common in blunt abdominal trauma (up to 50% of severe liver injuries) and penetrating trauma (up to 30% of stab wounds to the abdomen)
-The incidence of surgical intervention, including non-anatomical resection, varies based on injury severity and hemodynamic stability
-however, it remains a crucial technique in the armamentarium for managing hepatic trauma.
Clinical Significance:
-Effective management of liver lacerations is vital to control hemorrhage, prevent sepsis, and preserve liver function
-Non-anatomical resection offers a less morbid approach than formal anatomical resection when indicated, allowing for rapid control of bleeding and removal of non-viable tissue, thereby improving patient outcomes in emergent settings and is frequently tested in surgical postgraduate exams.

Clinical Presentation

Symptoms:
-Right upper quadrant (RUQ) abdominal pain
-Tenderness in the RUQ
-Abdominal distension
-Signs of hypovolemic shock: hypotension, tachycardia, pallor, diaphoresis
-Hematemesis or melena if associated with gastrointestinal injury.
Signs:
-Abdominal tenderness and guarding
-Rebound tenderness
-Palpable mass in RUQ
-Ecchymosis or bruising in the flank (Grey-Turner's sign) or around the umbilicus (Cullen's sign) in severe cases
-Hemodynamic instability (hypotension, tachycardia).
Diagnostic Criteria:
-Diagnosis is primarily based on clinical suspicion in a trauma patient with hemodynamic instability or significant abdominal findings
-Imaging confirmation is usually required
-No specific "criteria" exist for diagnosing the need for non-anatomical resection
-rather, it is a surgical decision based on the intraoperative findings of the extent of injury and the presence of ongoing bleeding or devitalized tissue.

Diagnostic Approach

History Taking:
-Mechanism of injury: blunt (high-speed motor vehicle accident, fall, assault) or penetrating (stab, gunshot)
-Associated injuries
-Pre-existing medical conditions (coagulopathy, liver disease)
-Medications (anticoagulants, antiplatelets)
-Last meal
-Allergies.
Physical Examination:
-Assess for signs of hypovolemic shock
-Perform a thorough abdominal examination, noting tenderness, guarding, distension, and any signs of peritoneal irritation
-Examine the chest, pelvis, and extremities for associated injuries
-Re-assess vital signs frequently.
Investigations:
-Focused Assessment with Sonography for Trauma (FAST) scan: initial rapid assessment for free fluid in the abdomen, pelvis, and pericardium
-Computed Tomography (CT) scan with intravenous contrast: the gold standard for evaluating liver injury severity, extent of laceration, presence of active bleeding (blush), and associated injuries
-Laboratory tests: complete blood count (CBC) to assess hemoglobin and platelet count, coagulation profile (PT, PTT, INR) to assess hemostasis, liver function tests (LFTs) to assess baseline hepatic function and detect injury, serum lactate to assess tissue perfusion.
Differential Diagnosis:
-Other intra-abdominal organ injuries (spleen, kidney, bowel)
-Retroperitoneal hematoma
-Diaphragmatic rupture
-Gastric or duodenal perforation
-Mesenteric hematoma.

Management

Initial Management:
-ATLS (Advanced Trauma Life Support) principles
-Resuscitation with intravenous fluids and blood products to achieve hemodynamic stability
-Airway, breathing, and circulation management
-Placement of nasogastric tube
-Foley catheter insertion
-Pain control.
Medical Management:
-Correction of coagulopathy: administration of fresh frozen plasma (FFP), cryoprecipitate, prothrombin complex concentrate (PCC), or platelets as indicated
-Tranexamic acid administration in bleeding trauma patients
-Titration of vasopressors and inotropes if hemodynamic instability persists despite fluid resuscitation.
Surgical Management:
-Indications for operative intervention include hemodynamic instability refractory to resuscitation, ongoing significant bleeding, extensive devitalized tissue, or associated hollow viscus injury
-The goal is to achieve hemostasis and debride non-viable tissue
-Non-anatomical resection involves excising the lacerated edge of the liver parenchyma using cautery, harmonic scalpel, or simple dissection, with careful ligation of visible bleeding vessels and bile ducts
-Packing the raw surface with hemostatic agents (e.g., Surgicel, Gelfoam) may be employed
-In some cases, simple hemostatic sutures may suffice for superficial lacerations.
Supportive Care:
-Close monitoring of vital signs, urine output, and abdominal girth
-Blood product transfusions as needed
-Nutritional support, often initiated early
-Management of pain and sedation
-Prophylaxis against deep vein thrombosis (DVT) and stress ulceration
-Antibiotic prophylaxis for intra-abdominal infections, guided by injury pattern and local protocols.

Complications

Early Complications:
-Hemorrhage: continued bleeding from the resection site or other injured vessels
-Biliary leak or fistula: leakage of bile from transected bile ducts
-Intra-abdominal abscess or hematoma formation
-Sepsis
-Acute liver failure.
Late Complications:
-Post-traumatic hepatic cyst or pseudocyst formation
-Biliary strictures
-Adhesions
-Chronic pain
-Hepatic venous outflow obstruction (rare).
Prevention Strategies:
-Meticulous hemostasis during surgery
-Careful identification and ligation of bile ducts
-Adequate debridement of devitalized tissue
-Prompt and aggressive management of coagulopathy
-Judicious use of hemostatic agents
-Early mobilization and nutritional support
-Close postoperative monitoring.

Prognosis

Factors Affecting Prognosis:
-Severity of liver injury (AAST classification)
-Presence and severity of associated injuries
-Hemodynamic stability at presentation and response to resuscitation
-Promptness of diagnosis and intervention
-Patient's underlying comorbidities (e.g., liver cirrhosis, coagulopathy).
Outcomes:
-With timely and appropriate management, including non-anatomical resection when indicated, the prognosis for liver trauma can be favorable
-Morbidity and mortality are significantly influenced by the degree of shock and the presence of other life-threatening injuries
-Patients undergoing non-anatomical resection for isolated liver injury often have good functional recovery.
Follow Up:
-Postoperative follow-up typically involves serial physical examinations, laboratory monitoring (CBC, LFTs), and imaging (ultrasound or CT) to assess for complications such as abscesses, bilomas, or recurrent bleeding
-Duration of follow-up depends on the severity of the injury and the presence of complications.

Key Points

Exam Focus:
-Non-anatomical resection is reserved for specific situations in liver trauma, primarily to control hemorrhage and debride devitalized tissue when anatomical resection is not feasible or necessary
-Indications are usually hemodynamic instability and active bleeding
-AAST injury grading is crucial for management decisions.
Clinical Pearls:
-Always consider associated injuries in polytrauma
-Intraoperative ultrasound can be invaluable for assessing the extent of injury and identifying bleeding sources
-Ligate all visible bleeding vessels and bile ducts encountered during resection
-Pack the liver bed judiciously if oozing persists, but avoid excessive packing that can compromise outflow.
Common Mistakes:
-Delaying operative intervention in hemodynamically unstable patients
-Undertreating coagulopathy
-Inadequate debridement of necrotic tissue, leading to infection or abscess
-Attempting complex anatomical resections in unstable patients
-Neglecting associated injuries.