A Study of a New Local Anesthesia Method for Transperineal Prostate Biopsy

In comparison with transrectal prostate biopsy, transperineal prostate biopsy has the advantage of better sampling from the anterior area, low risk of infection, and no rectal bleeding. The main problems associated with the transperineal method are pain control and additional general or spinal anesthesia. Three types of anesthesia have been reported for transperineal prostate biopsy: (1) spinal anesthesia; (2) general anesthesia; and (3) local anesthesia. From the viewpoint of patient selection (general anesthesia is contraindicated in some patients) and medical cost, local anesthesia is the most suitable choice for prostate biopsy. Periprostatic block is the standard method of local anesthesia for this procedure. However, periprostatic block is insufficient for transperineal prostate biopsy due to high pain sensitivity in this region. A number of new methods to eliminate pain have been reported, including (1) periapical triangle (PAT) block, (2) paraprostatic plus sexual nerve block, and (3) periprostatic block plus pudendal block.However, there is no anatomical basis for some of these methods, and there have been no randomized controlled trials to evaluate their effectiveness, and some methods are technically difficult to learn. In the previous perineal nerve autopsy, we found that there are two branches leading into the prostate and anterior lateral prostatic tissue, which is the main site of puncture pain. There is a fixed position where the two branches appear. Therefore, this anatomical position block may be a useful site for local anesthesia. We named this location the 'transperineal prostate biopsy local anesthesia switch' (abbreviated as TPA switch). In order to validate its effect, we organized this clinical trail.