What is the Zargar grading system for corrosive (chemical) injuries?

Zargar Grading System for Corrosive Injuries

The Zargar endoscopic classification is the most commonly used system for grading corrosive injuries of the gastrointestinal tract, providing critical prognostic information that guides management decisions and predicts complications such as stricture formation. 1

Zargar Classification Grades

The Zargar grading system consists of the following grades:

• Grade 0: Normal examination, no visible damage to mucosa
• Grade 1: Edema and hyperemia of the mucosa
• Grade 2: Subdivided into:
  • Grade 2A: Superficial ulcerations, erosions, exudates
  • Grade 2B: Deep discrete or circumferential ulcerations
• Grade 3: Subdivided into:
  • Grade 3A: Small scattered areas of necrosis
  • Grade 3B: Extensive necrosis
• Grade 4: Perforation

Clinical Significance and Management Implications

Grade 0-1 Injuries

• Low risk of complications
• Can be fed immediately and discharged quickly (24-48 hours)
• No long-term follow-up required as stricture risk is negligible 1, 2

Grade 2 Injuries

• Grade 2A: Low risk (<20%) of stricture formation
  • Oral nutrition can be introduced as pain diminishes
  • Follow-up recommended at 4-6 months post-ingestion 1
• Grade 2B: High risk (>80%) of stricture formation
  • May require nutritional support via parenteral nutrition or feeding jejunostomy
  • Close follow-up essential 1, 2

Grade 3-4 Injuries

• Indicate severe damage with high morbidity and mortality
• Grade 3B and 4 typically require emergency surgical intervention
• Associated with high risk of perforation and transmural necrosis 1

Anatomical Distribution of Injuries

• Upper esophagus is most commonly affected by corrosive substances (99.3% of cases)
• Lower esophagus tends to sustain more severe injuries (predominantly grade 2B in 32% of cases) 3
• No statistically significant differences in esophageal injury patterns based on age or gender 3

Current Role in Management

While the Zargar classification has traditionally been the cornerstone of management algorithms for caustic ingestions, recent evidence suggests that CT evaluation may be superior for:

1. Detecting transmural injuries of the gastrointestinal tract
2. Predicting esophageal stricture formation
3. Guiding decisions regarding emergency surgical intervention 1, 2

The current role of emergency endoscopy with Zargar grading is now primarily indicated when:

• CT is unavailable
• CT with contrast is contraindicated (renal failure, iodine allergy)
• CT findings are difficult to interpret
• In pediatric patients (to avoid radiation exposure) 1, 2

Management Based on Zargar Grading

• Non-operative management: Appropriate for grades 0-2A and selected 2B cases
• Endoscopic dilation: First-line treatment for strictures, typically started 3-6 weeks after ingestion
• Surgical management: Indicated for grades 3B and 4, or when complications develop
• Long-term follow-up: Essential for grades 2B and above to monitor for stricture formation 1, 2, 4

Prognostic Value

The Zargar grade correlates with clinical outcomes:

• Higher grades predict increased risk of complications
• Grade 2 esophageal injuries, particularly 2B, are associated with higher WBC count, longer hospital stays, and increased risk of serious complications 5
• Mortality is significantly higher in patients with grade 3B and 4 injuries requiring emergency surgery 6, 7

Despite its widespread use, it's important to note that the Zargar classification's ability to predict stricture formation remains somewhat controversial, and CT evaluation may provide more accurate prognostic information in adult patients 1, 2.