What is post‑hepatectomy liver failure, what are its diagnostic criteria and classification, and how should it be managed?

Post-Hepatectomy Liver Failure (PHLF): Definition, Criteria, Classification, and Management

PHLF is defined by the International Study Group of Liver Surgery (ISGLS) as impaired hepatic synthetic, excretory, and detoxifying functions characterized by increased INR and hyperbilirubinemia on or after postoperative day 5, with severity graded A through C based on clinical impact and management requirements 1, 2.

Definition and Diagnostic Criteria

PHLF represents failure of one or more synthetic and/or excretory liver functions following hepatic resection, manifesting as:

• Prolonged prothrombin time (INR elevation)
• Elevated serum bilirubin (hyperbilirubinemia)
• Elevated serum lactate
• Hypoalbuminemia
• Hypoglycemia
• Hepatic encephalopathy 1

The condition complicates up to one-third of major hepatic resections and remains the most common cause of post-resection mortality 1. The incidence varies dramatically based on underlying liver health: approximately 5% in patients with healthy livers versus up to 20% in those with chronic liver disease 1.

Classification Systems

1. The 50-50 Criteria (Balzan Criteria)

This prognostic tool, proposed in 2005, identifies patients at high mortality risk using two parameters measured on postoperative day 5:

• PT index < 50% (INR > 1.7)
• Serum bilirubin > 50 μmol/L (2.9 mg/dL)

When both criteria are met, mortality risk reaches 59% compared to 1.2% when absent (sensitivity 70%, specificity 98%) 1. This remains a highly specific predictor of PHLF-related mortality.

2. ISGLS Grading System (Gold Standard)

The ISGLS classification, established in 2011 and validated across multiple studies, defines PHLF as increased INR and hyperbilirubinemia on or after postoperative day 5, with three severity grades based on clinical management impact 1, 2:

Grade A PHLF:

• Postoperative deterioration requiring no change in clinical management
• Not associated with increased perioperative mortality
• Biochemical abnormality without clinical consequence

Grade B PHLF:

• Requires deviation from regular postoperative pathway
• No invasive treatment needed
• Associated with 12% perioperative mortality 1

Grade C PHLF:

• Requires invasive procedures or interventions
• Associated with 54% perioperative mortality 1

Recent evidence challenges the clinical insignificance of Grade A PHLF. While mortality remains similar to patients without PHLF (1.1% vs 1.2%), Grade A is associated with significantly increased morbidity (41.7% vs 19.3%), unplanned reoperation (OR 3.4), nonoperative interventions (OR 2.6), prolonged length of stay (OR 3.1), and readmission (OR 1.8) 3. Grade A PHLF should therefore be recognized as a clinically distinct entity requiring heightened surveillance despite preserved survival.

Pathogenesis and Risk Factors

PHLF primarily results from inadequate functional liver remnant (FLR) volume and/or quality 1. The liver's regenerative capacity depends on limiting cell death and recovering synthetic function, which can be impaired by:

Intraoperative factors:

• Hepatic ischemia-reperfusion injury
• Parenchymal congestion
• Reduced phagocytic ability
• Excessive blood loss (major determinant)
• Hemodynamic instability 1

Liver quality factors:

• Cirrhosis: Mortality 5-6.5%, PHLF risk 5-10%; higher in Child-Pugh B/C and portal hypertension 1
• Steatosis: PHLF risk increases to 14% vs 4% in normal livers 1
• Cholestasis: Morbidity 50% vs 15%, mortality 5-13% vs 0-6%, PHLF 5-17% vs 0-3% 1
• Neoadjuvant chemotherapy: Oxaliplatin (sinusoidal obstruction) and irinotecan (steatohepatitis) cause hepatotoxicity 1

Patient factors:

• ICG-R15 ≥ 10% (HR 4.352) 4
• Sarcopenia (HR 3.852) 4
• ASA-PS ≥ 3 4

Management Strategies

Prevention (Primary Strategy)

Pre-operative FLR volume optimization is the most important modifiable predictor of PHLF 1, 5. Patients with inadequate or borderline FLR must undergo volume augmentation:

Indications for FLR optimization:

• Extended hepatectomy or trisectionectomy (≥5 Couinaud segments)
• Underlying parenchymal disease
• Borderline FLR volume 1

Volume optimization techniques:

1. Portal vein embolization (PVE) - most consistent preventive measure 5
2. Two-stage hepatectomy with portal vein ligation (PVL)
3. Yttrium-90 radioembolization
4. ALPPS (Associating Liver Partition and Portal vein ligation for Staged hepatectomy) - achieves greater FLR hypertrophy (76% vs 37% with PVE) and higher completion rates (100% vs 77%), but carries significantly higher morbidity (73% vs 59%) and mortality (14% vs 7%) 1

Intraoperative measures:

• Judicious use of intermittent hepatic inflow occlusion (Pringle maneuver) to minimize blood loss
• Avoid excessive/prolonged venous inflow occlusion in cirrhotics with borderline FLR
• Meticulous surgical technique 1

Treatment of Established PHLF

Management mirrors strategies for acute liver failure, acute-on-chronic liver failure, and sepsis, focusing on supportive care rather than therapeutic interventions 1:

Supportive measures:

• Minimize hepatic insult
• Focus on end-organ function support
• Provide metabolic support (glucose management, correction of coagulopathy)
• Manage complications (encephalopathy, ascites, renal dysfunction)
• Prevent and treat infections aggressively

Definitive interventions (highly selective):

• Rescue hepatectomy - rarely feasible
• Liver transplantation - option for select patients meeting transplant criteria
• Generally not indicated for metastatic hepatic disease (exception: select neuroendocrine tumor patients) 1

Common Pitfalls

1. Underestimating Grade A PHLF: Despite no mortality increase, it carries significant morbidity requiring close monitoring 3
2. Inadequate pre-operative assessment: Failing to identify patients needing FLR optimization leads to preventable PHLF
3. Proceeding with resection in high-risk patients: Those with ICG-R15 ≥10% or sarcopenia require careful risk-benefit analysis 4
4. Excessive intraoperative ischemia: Prolonged Pringle maneuver in cirrhotic patients with borderline FLR impairs regeneration 1

Monitoring Algorithm

Postoperative day 5 assessment (critical timepoint):

• Measure INR and total bilirubin
• Apply 50-50 criteria for mortality risk stratification
• Apply ISGLS grading for management planning

If PHLF diagnosed:

• Grade A: Maintain standard pathway with enhanced surveillance
• Grade B: Modify clinical pathway, increase monitoring frequency
• Grade C: Initiate invasive interventions, consider ICU transfer, evaluate for rescue options

The resistance of PHLF to treatment and its high mortality (up to 54% in Grade C) underscore that prevention through adequate pre-operative assessment and FLR optimization remains far superior to any treatment strategy 1, 6.