Botox and CCBs were equivalent to GTN in efficacy with fewer adverse events .
No medical therapy came close to the efficacy of surgical sphincterotomy , though none in these RCTs was associated with the risk of incontinence .
Medical therapy for chronic anal fissure , acute fissure and fissure in children may be applied with a chance of cure that is marginally better than placebo , and , for chronic fissure in adults , far less effective than surgery
BACKGROUND Because of the disability associated with surgery for anal fissure and the risk of incontinence , medical alternatives for surgery have been sought .
Most recently , pharmacologic methods that relax the anal smooth muscle , to accomplish reversibly what occurs in surgery , have been used to obtain fissure healing .
OBJECTIVES To assess the efficacy and morbidity of various medical therapies for anal fissure .
A perfect correlate does not a surrogate make
Background There is common belief among some medical research ers that if a potential surrogate endpoint is highly correlated with a true endpoint , then a positive ( or negative ) difference in potential surrogate endpoints between r and omization groups would imply a positive ( or negative ) difference in unobserved true endpoints between r and omization groups . We investigate this belief when the potential surrogate and unobserved true endpoints are perfectly correlated within each r and omization group . Methods We use a graphical approach . The vertical axis is the unobserved true endpoint and the horizontal axis is the  potential surrogate endpoint  . Perfect correlation within each r and omization group implies that , for each r and omization group , potential surrogate and true endpoints are related by a straight line . In this scenario the investigator does not know the slopes or intercepts . We consider a plausible example where the slope of the line is higher for the experimental group than for the control group . Results In our example with unknown lines , a decrease in mean potential surrogate endpoints from control to experimental groups corresponds to an increase in mean true endpoint from control to experimental groups . Thus the potential surrogate endpoints give the wrong inference . Similar results hold for binary potential surrogate and true outcomes ( although the notion of correlation does not apply ) . The potential surrogate endpointwould give the correct inference if either ( i ) the unknown lines for the two group coincided , which means that the distribution of true endpoint conditional on potential surrogate endpoint does not depend on treatment group , which is called the Prentice Criterion or ( ii ) if one could accurately predict the lines based on data from prior studies . Conclusion Perfect correlation between potential surrogate and unobserved true outcomes within r and omized groups does not guarantee correct inference based on a potential surrogate endpoint . Even in early phase trials , investigators should not base conclusions on potential surrogate endpoints in which the only validation is high correlation with the true endpoint within a group
Botox and CCBs were equivalent to GTN in efficacy with fewer adverse events .
No medical therapy came close to the efficacy of surgical sphincterotomy , though none in these RCTs was associated with the risk of incontinence .
Medical therapy for chronic anal fissure , acute fissure and fissure in children may be applied with a chance of cure that is marginally better than placebo , and , for chronic fissure in adults , far less effective than surgery
BACKGROUND Because of the disability associated with surgery for anal fissure and the risk of incontinence , medical alternatives for surgery have been sought .
Most recently , pharmacologic methods that relax the anal smooth muscle , to accomplish reversibly what occurs in surgery , have been used to obtain fissure healing .
OBJECTIVES To assess the efficacy and morbidity of various medical therapies for anal fissure .