Infectious complications after transrectal ultrasound-guided prostatic biopsy. Analysis of our experience.

Objectives: To establish the rate of infectious complications derived from the use of transrectal ultrasound-guided prostate biopsy (TRUS), identify its microbiological profile and related risk factors.

Methods: We designed a prospective non-randomized study in which we enrolled 220 patients undergoing TRUS biopsy at our centre between April and September 2008. The inclusion criteria were: suspicious digital rectal examination, PSA >10 ng/ml, and free/total ratio of PSA is assessed in patients with PSA 4-10 ng/ml. The exclusion criteria were: having an indwelling urinary catheter, the administration of antibiotic treatment in the week before the needle biopsy, manipulation of the urinary tract in the month prior to the needle biopsy, allergy to quinolones and risk of endocarditis, failure to comply with the antibiotic prophylaxis regimen and loss to follow-up. We analyzed the relationship between diabetes, immunodepression, previous UTI or prostatitis and positive prebiopsy urine culture with the appearance of fever, dysuria or bacteriuria following needle biopsy.

Results: Mean age was 69.5 years (+/-7.9), mean total PSA 12.7 ng/ml (+/-28.7), mean prostate volume 50.6 cc (+/-29.6) and mean number of cores obtained by needle biopsy 13.5 (+/-1.7). 25% of the patients had dysuria following needle biopsy, 3.2% fever and 4.5% bacteriuria. E.coli was the pathogen most frequently found in pre- and post-biopsy urine cultures. No statistically significant relationship was found between the appearance of dysuria and fever and being diabetic, having immunosuppression, previous UTI or prostatitis, prostate volume and number of cores obtained in the biopsy. Only the existence of a positive pre-biopsy urine culture and biopsy with more than 14 cores proved to have a statistically significant association with the existence of bacteriuria following biopsy, p=0.007 and p= 0.018, respectively.

Conclusions: Our rate of infectious complications was similar to that described in other series. The existence of a positive prebiopsy urine culture and obtaining more than 14 cores per biopsy was related, with statistical significance, to the existence of bacteriuria following the biopsy. E.coli was the most frequently isolated pathogen.