Marmo et al recently published a meta-analysis on this topic. Unfortunately, it is plagued by several problems. First, in the plot of odds ratios for rebleeding, the CIs for Messmann et al’s study are shown as not crossing 1.0, in spite of the fact that the differences in rebleeding rates in that study were clearly not significant. Second, there was significant clinical heterogeneity in patient characteristics and initial and subsequent treatment. Although statistical heterogeneity appeared to be absent, no attempt was made to correct for clinical heterogeneity (eg, no variables were assigned to each study to try to adjust for these differences). It is well known that the power of conventional tests of statistical heterogeneity is poor. Even overlooking these flaws, only a minimal difference in rebleeding was found (6.2%), with a CI of 1.3% to 11%. The upper range for the number needed to treat CI, to prevent one rebleeding episode, was 75. The meta-analysis found no differences in surgery or mortality rates.
Although it is theoretically reasonable to entertain a second look endoscopy in patients with bleeding peptic ulcers and high risk stigmata, it appears to be ineffective in randomized trials. Approximately 20% of all rebleeding episodes occur before the planned second procedure at 24 h to 48 h. In addition, persistent, high risk lesions are seen in only approximately one-half of patients who undergo repeat endoscopy; this proportion strongly depends on the timing of the second look.