Liver: Liver Biopsy & Resection

Liver Biopsy

Routes

  • Percutaneous – Preferred (Less Invasive & Less Costly)
  • Transjugular – If Percutaneous Contraindicated
  • Laparoscopic

Percutaneous Liver Biopsy

  • Procedure:
    • Position: Supine, Right Hand Over Head
    • Local Anesthetic Over Top of Rib
    • Pass Needle Under US-Guidance
    • Obtain While Holding Breath
  • Contraindications:
    • Absolute Contraindications:
      • Encephalopathy & Unable to Cooperate
      • Unable to Identify Adequate Bx Site
      • Significant Coagulopathy
      • NSAID Use < 7-10 days
      • Patient Refusal to Accept Blood Transfusion
      • Suspected Vascular Lesion or Echinococcal Cyst
      • Extrahepatic Biliary Obstruction
    • Relative Contraindications:
      • Morbid Obesity
      • Cirrhosis/Ascites
      • Hemophilia
      • Infection of Right Pleural Cavity or Below Right Hemidiaphragm
      • Amyloidosis
  • Complications:
    • Pain (Most Common Complication)
    • Intraperitoneal Hemorrhage (Most Common Serious Complication)
    • Transient Bacteremia
    • Bile Peritonitis
    • PTX/HTX

Transjugular Liver Biopsy

  • Bleeding Directed into Access Vein, Minimize Hemorrhage Risk
  • Can Be Done Simultaneously With: TIPS or Hepatic Venous Pressure Gradient Measurement
  • Biopsy is Non-Targeted
  • Contraindications: Requirement of Targeted-Bx or Renal Failure (Contrast)

Hepatic Resection (Hepatectomy)

Indications

  • Malignancy (Most Common)
  • Some Benign Pathologies
  • Trauma

Types

  • Wedge Resection: “V”-Shaped Portion at the Liver Margin
  • Segmental Resection: Full Anatomic Segment
  • Sector/Section Resection (Sectorectomy/Sectionectomy) – Multiple Anatomic Segments
    • Left Lateral Segmentectomy: Segments 2 & 3
    • Right Lateral Segmentectomy: Segments 6 & 7
  • Hemihepatectomy (Lobectomy) – Left or Right Side
    • Left Hemihepatectomy: Segments 2-4
    • Right Hemihepatectomy: Segments 5-8
  • Extended Hemihepatectomy (Trisectionectomy/Extended Lobectomy) – Includes Median Portion of Opposite Side
    • Extended Left Hemihepatectomy: Segments 2-5 & 8
    • Extended Right Hemihepatectomy: Segments 4-8

Procedure

  • Consider Portal Vein Embolization if Functional Liver Remnant Too Small
  • If for Malignancy: First Preform Staging Laparoscopic & Intraoperative US to Confirm Resection is Possible
  • Start Resection with Cholecystectomy for All Major Resections
    • Permits Safe Dissection of Portal Structures & Prevents Future Gallbladder Pathology
    • Not Necessary for Wedge Resection
  • Vascular Control
    • Selectivity
      • Selective Control (Isolated Vessels): Preferred
      • Concurrent Control (Pringle Maneuver): If Emergent
    • Intermittent Occlusion (vs. Continuous) Has Less Hepatic Injury
  • Routine Postoperative Drain Not Indicated

Complications

  • Bile Leak
  • Portal Vein Thrombosis
  • Liver Failure
  • Ascites

Portal Vein Embolization (PVE)

Basics

  • Endovascular Embolization of the Portal Venous Supply to a Disease Portion of the Liver
    • Induces Atrophy of Diseased Section by Apoptosis (Not Necrosis)
    • Other Segments Consequently Undergo Hyperplasia – Increased Number of Hepatocytes (Not Hypertrophy – Increased Size)
    • Enables a Larger Functional Liver Remnant Post-Resection
  • Wait 3-6 Weeks for Resection (Repeat Imaging Prior to Surgery)
  • Indications: Used Prior to Hepatic Resection for Primary Hepatic Malignancies or Metastatic Tumors of Functional Liver Remnant Will Be Insufficient
  • Absolute Contraindications:
    • Resection Contraindicated (Child’s B/C Cirrhosis, etc.)
    • Extensive Ipsilateral Tumor Thrombus (Most of Portal Flow Has Already Been Diverted)
    • Portal Hypertension (May Worsen)
    • Insufficient Predicted Post-PVE FLR

Functional Liver Remnant (FLR)

  • Calculated Using Volumetrics on 3-D Reconstruction of CT or MRI
  • FLR (%) = FLRV / TLV
    • FLRV: Future Liver Remnant Volume
      • FLRV = TLV – RV
      • RV: Volume to be Resected
    • TLV: Total Liver Volume (Functional/Nontumoral)
      • TLV = TLVMRI – TV
      • TLVMRI: Total Liver Volume by MRI (Including Tumor)
      • Tumor Volume = TV

Functional Liver Remnant (FLR) Thresholds

  • Standardized FLR: Mn
    • Healthy: 20%
    • Hepatitis, Steatosis or Chemo: 30%
    • Cirrhosis (Child’s A): 40%
  • Truant Criterion (Based on FLR to Body Weight Ratio):
    • Healthy: 0.5%
    • Hepatitis, Steatosis or Chemo: 0.8%
    • Cirrhosis (Child’s A): 1.4%
  • Shirabe Criterion (Based on FLR Total Volume):
    • Cirrhosis (Child’s A): 250 mL/m2

Procedure

  • Approach:
    • Percutaneous Transhepatic/Transjugular (Preferred Route)
    • Transileocolic by Laparotomy
      • Original Route, Now Rarely Preformed
      • If Preforming Laparotomy for Other Indication (Such as Staged Resection of Primary Colon Tumor)
  • With or Without Sequential Transarterial Chemoembolization (TACE)
    • Inhibits Interval Tumor Progression by Occluding Tumor Blood Flow
    • Inflammatory Response Adds to Regenerative Response

Mnemonics

Functional Liver Remnant (FLR) Thresholds

  • “Two-Three-Four” Needed Remnant of Liver Core
    • Healthy: 20%
    • Hepatitis, Steatosis or Chemo: 30%
    • Cirrhosis (Child’s A): 40%