Objectives: To introduce two forms of anesthesia and compare them with standard local anesthesia techniques.
Methods: A total of 114 consecutive patients underwent prostate needle biopsy. The patients were sequentially randomized to receive different kinds of anesthesia: 2% rectal lidocaine gel, 40% dimethyl sulfoxide (DMSO) with lidocaine, perianal injection of 1% lidocaine, or periprostatic nerve block. Pain perception was separately assessed for probe insertion and biopsies using a visual pain analog score. One-way analysis of variance was used to compare the data scale among the four groups. A linear regression model was used to define the independent variables that predicted the level of pain.
Results: The groups were similar in terms of age, prostate-specific antigen levels, digital rectal examination findings, prostate volume, pain tolerance, biopsy time, and number of cores taken. The lowest pain scores for probe insertion were for the perianal injection and DMSO/lidocaine groups (0.89 and 1.38, respectively). The difference between these scores and those for the other two groups was statistically significant (P <0.001). Pain perception during biopsy did not differ significantly among the DMSO/lidocaine, perianal, or periprostatic groups and was greatest in the lidocaine gel group (4.147; P <0.001). We did not observe any statistically significant correlation between the pain level during probe insertion and biopsy and pain tolerance (P = 0.514 and P = 0.788, respectively). The anesthesia type was the strongest single predictor of the pain level during biopsy (P <0.001).
Conclusions: The use of 40% DMSO with lidocaine instilled into the rectal vault for 10 minutes avoids any need for injection and is capable of decreasing the discomfort or pain experienced during probe insertion and prostate biopsy comparable to the perianal and periprostatic protocols.