A rare complication of transrectal ultrasound guided prostate biopsy: rectourethral fistula

Abstract

Introduction: Transrectal ultrasound guided prostate biopsy (TRUS Bx) is the standard procedure for investigation of raised prostate specific antigen (PSA) levels or abnormal digital rectal examination (DRE) findings. It is considered a safe and effective diagnostic tool. However, TRUS Bx is not completely free from serious complications. We report a case of rectourethral fistula (RUF) post TRUS Bx, presenting with sepsis. Case report: A 84 gentleman with good past health presented with incidental finding of raised PSA level of 35 ug/L. DRE showed an enlarged, hard and fixed right lobe of prostate, with obliteration of median groove. TRUS Bx was arranged. Three days of oral ciprofloxacin 500mg bd as antibiotics prophylaxis and fleet enema were given before the procedure. Sextant TRUS Bx was performed by radiologist. The prostate gland was markedly enlarged, > 200ml in volume; with irregular outline and distorted internal anatomy. Pathology came back to be adenocarcinoma of prostate, GS 4 +4 over all six cores. Bone scan showed bone metastasis over sacro-coccygeal and bilateral acetabular regions. He was readmitted for post- TRUS Bx fever 2 days afterwards, which did not subside with intravenous antibiotics: Sulperazone (Cefoperazone/ sulbactam) and metronidazole. Urine culture yielded insignificant count, whereas blood C/St grew Bacteroides species. White cell count was persistently elevated at 24.5 ×10^9/L. He developed abdominal distension and DRE showed irregular mucosa over anterior rectal wall CT abdomen & pelvis with contrast showed prostate abscess, rectal perforation with intestinal obstruction, and enlarged prostate with lost of fat plane with seminal vesicles. Defunctioning transverse colostomy was performed due to overt sepsis and an attempt to allow the fistula to heal. Reassessment CT scan 2 months later showed no residual prostate abscess. Loopogram via rectum and transverse colostomy showed no leakage of contrast into urinary system. Closure of colostomy is pending. Concerning the treatment of CA prostate, he opted for hormonal treatment with LHRH agonist. The latest PSA is <0.1 ug/L. Discussion: The most common cause of RUF in modern series is post-radical prostatectomy. Other causes include cryotherapy, pelvic radiotherapy and anorectal surgery. It is rare for rectourethral fistula to occur post TRUS prostate biopsy. Patients with RUF present with urine per rectum, pneumaturia, recurrent urinary tract infections or fecularia, or rarely, as in our case – overt sepsis. There are two approaches in the management of RUF: conservative Vs surgical. Conservative management includes faecal diversion with colostomy and either suprapubic cystostomy or indwelling urethral catheter. The rationale behind conservative management is to allow symptomatic control and attempts to allow spontaneous healing of the fistula. However, conservative management is unpredictable and the time to allow healing is unknown. In our case, the RUF healed with a period of defunctioning colostomy. Conclusion: We have described a case of rectourethral fistula after TRUS Bx, which resolved with defunctioning colostomy and antibiotics. To our knowledge, this is the first reported case of post TRUS Bx rectourethral fistula.