Rebleeding Risk 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
Forrest Classification and Associated Rebleeding Risks
Forrest Ia (Spurting arterial bleeding): Highest risk of rebleeding (22.5% after endoscopic hemostasis), with 100% baseline arterial flow detected by Doppler probe and 35.7% residual blood flow after treatment 1, 2
Forrest Ib (Oozing bleeding): Surprisingly lower risk of rebleeding (4.9%) compared to Forrest IIa and IIb, with only 46.7% baseline arterial flow detected by Doppler and 0% residual blood flow after treatment 1, 2
Forrest IIa (Non-bleeding visible vessel): Moderate-high risk of rebleeding (11.3%), requiring endoscopic hemostasis 1, 3
Forrest IIb (Adherent clot): High risk of rebleeding (17.6%), though management approach varies between cautious irrigation versus aggressive clot removal 1, 4
Forrest IIc (Flat spot) and Forrest III (Clean ulcer base): Low rebleeding risk, with rates of approximately 4.8% and <1% respectively 5, 6
Risk Stratification Beyond Visual Classification
Doppler probe assessment provides superior risk stratification compared to visual Forrest classification alone, detecting arterial flow in 87.4% of major SRH (Forrest Ia, IIa, IIb) versus only 42.3% in intermediate risk lesions (Forrest Ib, IIc) 2
Forrest Ib lesions have been traditionally classified as high-risk, but recent evidence suggests they have significantly lower rebleeding rates than previously thought, challenging their classification 1
Residual arterial blood flow detected after endoscopic treatment is a stronger predictor of rebleeding than visual stigmata alone 2
Management Implications Based on Forrest Classification
Forrest Ia, IIa, IIb: Require aggressive endoscopic hemostasis, preferably with dual modality (mechanical therapy plus epinephrine injection) which reduces rebleeding (OR 0.19,95% CI 0.07-0.52) and need for surgery (OR 0.10,95% CI 0.01-0.50) 4, 3
Forrest Ib: Despite traditional classification as high-risk, these lesions have very low rebleeding rates after successful endoscopic hemostasis regardless of PPI treatment (5.4% with PPI vs. 4.9% with placebo), suggesting potential reclassification as lower risk 1
Forrest IIb (Adherent clot): Management remains controversial - WSES advocates non-aggressive clot irrigation rather than mechanical dislodgment, while Asia-Pacific guidelines suggest vigorous target irrigation for at least 5 minutes 4
Forrest IIc and III: Generally do not require endoscopic hemostasis due to low rebleeding risk 6
Post-Endoscopic Management
After successful endoscopic hemostasis for high-risk lesions (particularly Forrest Ia, IIa, IIb), high-dose PPI as continuous infusion for the first 72 hours is recommended to reduce rebleeding risk 4, 3
PPI therapy should be continued for 6-8 weeks following endoscopic treatment, with long-term PPI only indicated for patients with ongoing NSAID use 4
For extremely high-risk patients with Forrest Ia, Ib, or IIa lesions and Rockall score ≥5, preventive transarterial embolization (P-TAE) following endoscopic hemostasis may significantly reduce rebleeding rates (3.4% vs. 16.2%) 7
Doppler probe-guided endoscopic hemostasis has been shown to significantly reduce 30-day rebleeding rates compared to standard visually guided hemostasis 4, 2