The Clinical Study Of Pain And Prevention Of Infection Following Transrectal Ultrasound Guided Prostate Biopsy

With the routine use of PSA, more and more patients need undergoing transrectal ultrasound-guided prostate biopsy using an 18-gauge needle loaded on a spring biopsy gun in order to diagnose prostate cancer early, then they could be performed radical operation for a longer lives. It is a long time that prostate biopsy guided by TRUS is considered a minor procedure that is tolerated by most patients and it is commonly performed as an office procedure with no anaesthesia. But we observed that prostate biopsy is perceived as painful by most of patients and little of them finally gave up biopsy for severe pain, which resulted in prostate cancer may be overlooked.Biopsies taken at the prostatic apex are often more painful than those from other areas of the gland. By studying the timing of pain and puncture position, we found the reason of pain of apex biopsy was that biopsy needle pierced anal skin, which was concerned with B-K 8808 type biplane transrectal transducer. The needle orifice of this transducer is 3cm away from the tip of transducer and the angle of puncture is 30°between biopsy needle and transducer. During biopsy, though ultrasound picture showed total prostate, the biopsy needle may be below the dentate line of anal canal. The occasion occurred more easily when the location adjacent to the prostatic apex. Dentate line is only a anatomic label, which is not visible ultrasonographically but it is slightly caudal to the prostatic apex in most patients. Anal canal skin is dominated by somatic nerve, which is sensitive to pain, rectal mucosa above dentate line is dominated by autonomic nerve, which is hypalgesia to pain. Without ultrasound visualization the dentate line can only be reliably bypassed by the rectal sensation test. We designed 3 groups to perform a randomed, control, prospective trial. The patient was asked if he felt the sharp of the needle as it was placed lightly against the rectal mucosa when the needle was aimed at apex (the rectal sensation test). If so, the transducer was advanced cranially 2 to 3 mm or until he could no longer detect pain sensation. The probe handle was then rotated dorsally, pulling the rectal mucosa downward until the needle was again aimed at the apex. Patients were asked to report a visual analog pain score for apical biopsy. The average pain score of pain testing group was 1.98±0.67 and anal canal anaesthesia group 1.84±0.75, lower than control group 4.46±1.24. These results were statistically significant (P<0.05). But anal canal anaesthesia itself can provoke obvious pain(score is 5.24±0.83), and biopsy through anal canal also can produce crissum pain after biopsy(anal anaesthesia 1case, control group 1case). Pain testing group have no crissum pain. As the general applications of not end-fire transrectal transducer similary to B-K 8808 type, pain testing technique play a significant role in avoiding pain of apical prostate biopsy.Though the biopsy needle above the dentate line, we also observed most of patients suffered from pain during transrectal prostate biopsy. 65% to 90% of patients reportedly have discomfort in 2 studies. The reason was that prostatic capsule and parenchyma have autonomic nerve fibers. When puncture needle enter the prostate, it can stimulate visceral nerve of capsule and parenchyma and these neural fibers transmit vesical sensation from the prostate to the spinal cord, explaining the discomfort or pain associated with transrectal prostate biopsy. These nerves derived from the caudal roots of S2 to S5 and the sympathetic chain via the prescaral and hypogastric neural plexus. These fibers ramify in the prostatic plexus and subsequently travel with the prostatic vascular pedicles, which located at the posterolateral prostate aspect between prostate and Denonvillier' s fascia. In contrast, the anterior and supralateral aspects of prostate have no significant neural input. So we take local anaesthesia with lidocaine to block peripheral nerve of prostate to decrease pain during biopsy. Transrectal ultrasound-guided prostate bio...