Rectal sensation test helps make prostate biopsy less painful

A simple sensation test can determine the path that avoids rectal pain fibers when inserting a needle transrectally into the apical portion of the prostate, according to a report published in the December issue of The Journal of Urology. “Painless apical biopsy can then be achieved,” the authors say.

In the past, pain during apical prostate biopsy has been blamed on the nerves in the gland itself. However, even with complete anesthetic blockage of periprostatic nerves, pain still occurs. Dr. J. Stephen Jones and Dr. Craig D. Zippe, from the Cleveland Clinic Foundation, believe that the residual pain of apical prostate biopsy may stem from the piercing of rectal pain fibers during the procedure. Since these nerves do not exist above the dentate line, aiming the biopsy needle above this line results in a less painful procedure.In the new study, the authors developed a simple method to identify the dentate line. After a periprostatic nerve block was created, the biopsy needle was placed lightly against the rectal mucosa and the patient was questioned regarding any sharp sensation.If necessary, the sensation test was repeated a few millimeters deeper until the region above the dentate line was identified. By manipulating the ultrasound probe, the authors were able to pass the needle above the dentate line while still in the direction of the apex.The current study involved 30 apical biopsies performed with the sensation test and 30 performed without the test. The average visual analog pain score with the test was 1.25, significantly lower than the score without the test-2.28. No complications occurred with any of the biopsies.”This technique does not compensate for inadequate or incomplete periprostatic block,” the authors emphasize. “However, if the prostate is adequately anesthetized, this technique allows the physician to bypass the anal pain fibers below the dentate line, which are the remaining potential source of pain during apical biopsy.”(Source: J Urol 2003;170:2316-2318: Reuters Health: December 29, 2003: Oncolink)