What is the risk of rebleeding in different Forrest classes of peptic ulcer?

Risk of Rebleeding in Different Forrest Classes of Peptic Ulcer

The risk of rebleeding varies significantly across Forrest classifications, with Forrest Ia (spurting arterial bleeding) having the highest rebleeding risk of approximately 22.5%, followed by Forrest IIb (adherent clot) at 17.6%, Forrest IIa (non-bleeding visible vessel) at 11.3%, and Forrest Ib (oozing bleeding) at only 4.9% after successful endoscopic hemostasis. 1

Rebleeding Risk by Forrest Classification

• Forrest Ia (spurting arterial bleeding): Highest risk of rebleeding (22.5% in patients receiving placebo after endoscopic hemostasis), with an odds ratio of 6.66 (95% CI: 2.19-20.26) compared to Forrest Ib 1
• Forrest Ib (oozing bleeding): Surprisingly low rebleeding risk (4.9%) after successful endoscopic hemostasis, which is lower than previously thought and lower than Forrest IIa and IIb 1, 2
• Forrest IIa (non-bleeding visible vessel): Moderate-high rebleeding risk (11.3%) with an odds ratio of 2.61 (95% CI: 1.05-6.52) compared to Forrest Ib 1, 2
• Forrest IIb (adherent clot): High rebleeding risk (17.6%), second only to Forrest Ia 1, 2
• Forrest IIc (flat pigmented spot) and Forrest III (clean ulcer base): Low rebleeding risk, rarely requiring hospitalization 3

Doppler Assessment and Risk Stratification

• Doppler probe assessment provides more accurate risk stratification than visual Forrest classification alone 4, 5
• Arterial blood flow detection rates by Doppler are significantly higher in major SRH (Forrest Ia, IIa, IIb) at 87.4% compared to 42.3% in intermediate risk lesions (Forrest Ib, IIc) 5
• For Forrest Ia vs Ib lesions, baseline arterial flow detection was 100% vs 46.7%, and residual blood flow after endoscopic hemostasis was 35.7% vs 0% 5
• This correlates with 30-day rebleed rates of 28.6% for Forrest Ia vs 0% for Forrest Ib 5

Management Implications Based on Forrest Classification

• Endoscopic hemostasis is strongly recommended for Forrest Ia, Ib, and IIa ulcers 2
• For Forrest IIb (adherent clot), the World Journal of Emergency Surgery recommends non-aggressive clot irrigation rather than mechanical dislodgment 4, 2
• Dual modality endoscopic hemostasis is preferred over single modality for high-risk lesions 2
• Mechanical therapy combined with epinephrine injection significantly reduces rebleeding (OR 0.19,95% CI 0.07-0.52) and need for surgery (OR 0.10,95% CI 0.01-0.50) 2
• After successful endoscopic hemostasis, high-dose PPI as continuous infusion for the first 72 hours is recommended 4, 2

Important Clinical Considerations

• The traditional view of Forrest Ib (oozing) as high-risk may need reevaluation, as recent evidence shows very low rebleeding rates (4.9%) regardless of PPI or placebo treatment after successful endoscopic hemostasis 1
• Preventive transarterial embolization (P-TAE) following endoscopic hemostasis in high-risk patients (Forrest Ia, Ib, IIa) with Rockall score ≥5 significantly reduces rebleeding rates (3.4% vs 16.2%) 6
• For patients with high-risk stigmata, PPI therapy should be continued for 6-8 weeks following endoscopic treatment 4, 2
• Over 80% of ulcer bleeding stops spontaneously, but occurrence of rebleeding increases mortality 10-fold, emphasizing the importance of accurate risk stratification 3

Pitfalls and Caveats

• The Forrest classification may not be equally applicable to post-endoscopic resection ulcers as it is to peptic ulcers 7
• Relying solely on visual assessment without Doppler may lead to underestimation of rebleeding risk, particularly in Forrest IIa and IIb lesions 5
• Despite the low rebleeding risk of Forrest Ib after successful hemostasis, these lesions still require initial endoscopic treatment 1
• The benefit of high-dose PPI may be less significant for Forrest Ib lesions compared to other high-risk stigmata 1