A 55-Year-Old Male with Recurrent Colicky Left Flank Pain , Iatrogenic Sprinkler-Type Perineal Urethrocutaneous Fistula and Pubic Ramus Osteomyelitis

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 Case Study: A 55-Year-Old Male with Recurrent Colicky Left Flank Pain 

Iatrogenic Sprinkler-Type Perineal Urethrocutaneous Fistula and Pubic Ramus Osteomyelitis as a Complication of Post-Ureterolithotomy Urinary Tract Infection

Iatrogenic Sprinkler-Type Perineal Urethrocutaneous Fistula and Pubic Ramus Osteomyelitis

Abstract
This case involves a 55-year-old male patient with a history of transurethral ureterolithotomy, who subsequently developed a urinary tract infection (UTI) complicated by a periurethral abscess, osteomyelitis of the inferior pubic ramus, and the development of a urethrocutaneous fistula following surgical drainage of the abscess. UTI complicated by a periurethral abscess and urethrocutaneous fistula—resembling a "sprinkler-type" perineal fistula—is an uncommon clinical entity. To date, the occurrence of periurethral abscess-associated osteomyelitis of the pubic ramus has not been previously reported in the literature.

History and Imaging Findings

  1. A 55-year-old non-diabetic, normotensive male with a history of recurrent colicky left flank pain presented with acute urinary retention. Attempts at urethral catheterization were unsuccessful.

  2. Ultrasound examination revealed an overdistended urinary bladder with a normal-sized prostate, along with scarring of the left kidney and focal ureteral ectasia (Figure 1a).

Figure 1. Preoperative Ultrasound Images of the Patient
(a) Longitudinal view of the left kidney showing cortical scarring (arrow) and ureteral ectasia (asterisk).
(b) Sagittal perineal image demonstrating a perineal abscess (ab) in association with a swollen penile root (r); the anal canal (ac) and urinary bladder (u) appear unremarkable.
(c) Axial view showing a normal proximal penile urethra (arrow) along with intact corpora spongiosum (cs) and corpora cavernosa (cc).
(d) Axial image depicting the bulbar urethra (arrow) with surrounding edematous spongiosum.
(e) Sagittal perineal image illustrating the perineal abscess (ab) extending proximally to the corpus spongiosum (cs).

3. The right kidney appeared normal, and no calculi were detected in either kidney on ultrasound. Serum electrolytes, renal function, and liver function tests were within normal limits. Laboratory analysis revealed neutrophilia, and the prostate-specific antigen (PSA) level was within the normal range. A rigid urethroscopy was performed under the suspicion of a left-sided ureteral stone, during which an 11 mm calculus was successfully removed from the posterior urethra.

4. The patient experienced no voiding difficulties for two weeks following discharge. However, he subsequently developed dysuria with a burning sensation, hesitancy, and induration of the perineum. His urine appeared turbid, and Escherichia coli was identified on urinalysis. Perineal ultrasound revealed an abscess in the perineal region extending proximally to the corpus spongiosum of the urethra (Figure 1b–e).

5. The abscess was surgically drained under saddle block anesthesia. Following drainage, a cutaneous fistulous tract (Figure 2a) developed at the surgical site, from which purulent fluid was discharged. Retrograde urethrography demonstrated extravasation of contrast medium around the urethra and revealed a lytic lesion in the left pubic ramus (Figure 2b).

6. Repeated perineal ultrasound examinations demonstrated a linear hypoechoic tract extending from the skin surface to the corpus spongiosum (Figure 2c).

Figure 2.
(a) Postoperative clinical photograph showing the external opening of the fistulous tract.
(b) Retrograde urethrogram demonstrating contrast extravasation from the urethra extending to the skin surface (arrow), along with a lytic lesion in the left inferior pubic ramus (double arrow).
(c) Sagittal perineal ultrasound image showing the main fistulous tract (arrow) extending from the skin surface to the corpus spongiosum (asterisk).


7. To evaluate the extent of the abscess and delineate the fistulous tract, retrograde CT urography was performed. Non-contrast CT images revealed a lytic lesion involving the left inferior pubic ramus (Figure 3). The pubic symphysis and bilateral pubic bodies appeared normal. A proximal femoral fixation device was noted in place on the left side, corresponding to prior internal fixation for a proximal femoral shaft fracture sustained in a traumatic accident 10 years earlier. Following iodinated contrast injection into the urethra, contrast pooling was observed in the soft tissues surrounding the bulbar and posterior penile urethra.

Figure 3.
(a) Axial and (b) volume-rendered postoperative CT images showing a lytic lesion (arrow) in the left inferior pubic ramus.
8. Contrast extended through the external anal sphincter into the intersphincteric plane (Figure 4a), and an inflammatory tract involving the ischioanal fossae was identified. The contrast medium extravasated through the perineal cutaneous opening and the natal cleft (Figure 4c, d).

Figure 4.
Postoperative axial retrograde CT urethrography images (a and b) demonstrate contrast extending to the intersphincteric plane of the anal canal sphincter (arrow in a) and a lytic lesion in the left inferior pubic ramus (arrow in b).
Sagittal maximum intensity projection (c) and volume-rendered CT images (d) reveal a complex periurethral lesion connected to the perineal skin (arrow in c) and draining into the natal cleft (double arrow in c).


9. Escherichia coli was isolated from the pus culture. The patient received intravenous antibiotic therapy and underwent a suprapubic cystostomy. He is currently being considered for elective urethroplasty.

Quiz:

  1. What rare complication related to urinary tract infection did the patient experience following urethral stone removal?
    A. Benign prostatic hyperplasia
    B. Urethral stricture
    C. Periurethral abscess and urethrocutaneous fistula
    D. Bladder tumor

Explanation: This patient developed a rare but serious complication after rigid urethroscopy with stone removal — a periurethral abscess and urethrocutaneous fistula (watering-can perineum). This represents an atypical course of urinary tract infection (UTI), and the occurrence of periurethral abscess accompanied by pubic ramus osteomyelitis is exceptionally rare.

  1. Which pathogen was identified as the cause of infection in this patient?
    A. Staphylococcus aureus
    B. Escherichia coli
    C. Streptococcus pyogenes
    D. Klebsiella pneumoniae

Explanation: E. coli was isolated from the pus culture, confirming it as the infectious agent. E. coli is the most common causative organism of urinary tract infections and was directly responsible for the periurethral infection and abscess formation in this case.

  1. Which imaging finding is consistent with the formation of a urethrocutaneous fistula in this patient?
    A. Bilateral renal contraction on rigid cystography
    B. Contrast extravasation around the urethra on retrograde urethrography
    C. Bladder stone on computed tomography (CT)
    D. Calcification of the corpus cavernosum on magnetic resonance imaging (MRI)

Explanation: Retrograde urethrography demonstrated contrast leakage around the urethra, indicating the presence of a urethrocutaneous fistula. Additionally, CT urethrography revealed lytic lesions in the pubic ramus and contrast diffusion within surrounding soft tissues, clarifying the extent of the abscess and fistula tract.

Discussion

Before the advent of antibiotics, gonococcal urethritis was the most common cause of periurethral abscess formation.1–3 Currently, the most frequent pathogens causing urethritis include Gram-negative bacilli, enterococci, and anaerobes, with staphylococci and streptococci less commonly involved. Coagulase-negative staphylococci and Pseudomonas aeruginosa are typically seen in immunocompromised patients.1–4,9

Risk factors for periurethral abscess include ongoing urinary tract infection, indwelling catheters, undiagnosed urethral obstruction, and urethral trauma.2–5 Rarely, penile skin infection can be the source.1 Urethral stricture, periurethral bulking injections, urethral diverticula, and urethral calculi are also predisposing factors.2,3

Periurethral abscess occurs when an infected Littre’s gland ruptures, spreading infection into the submucosal tissue. Occasionally, these infections may form sizable localized abscesses.4 Untreated periurethral abscesses can progress to single or multiple urethrocutaneous fistulas, known as "watering-can perineum."1–3
These fistulas may open in the perineum, scrotum, penis, penoscrotal junction, or thighs. Initial management includes suprapubic cystostomy to relieve obstruction and allow healing, followed by elective urethroplasty after several months.5

The latency period between gonorrheal infection and such sequelae can range from months to 50 years.6,9 Emphysematous periurethral abscesses have been reported in diabetic patients. 7,10 Pelvic osteomyelitis is a rare complication; osteomyelitis of the pubic ramus without involvement of the pubic body or symphysis is scarcely reported.11 Recently, cases of pubic osteomyelitis with vesicocutaneous and vesicovaginal fistulas as delayed complications of cervical cancer radiotherapy have been described.8 To our knowledge, cases associating pubic osteomyelitis with periurethral abscess and urethrocutaneous fistula have not been reported previously.

Key Learning Points

  1. Before antibiotics, gonococcal urethritis was the leading cause of periurethral abscess.

  2. Nowadays, Gram-negative bacilli, enterococci, and anaerobes are the most common pathogens.

  3. Risk factors include persistent UTI, indwelling catheters, undiagnosed urethral obstruction, and urethral trauma.

  4. Urethral stricture, periurethral bulking injections, urethral diverticula, and urethral calculi are additional risk factors.

  5. Periurethral abscess arises from rupture of infected Littre’s glands, spreading infection into submucosal tissues.

  6. An untreated periurethral abscess may progress to one or multiple urethrocutaneous fistulas ("watering-can perineum").

  7. "Watering-can perineum" is a common late complication of long-standing inflammatory urethral stricture.

  8. Pelvic osteomyelitis is rare, and osteomyelitis isolated to the pubic ramus without involvement of the pubic body or symphysis is rarely reported.

References

  1. Kraus S, Luedecke G, Ludwig M, Weidner W. Periurethral abscess formation due to Neisseria gonorrhoeae. Urol Int 2004; 73: 358–60. doi: 10.1159/000081600

  2. Komolafe AJ, Cornford PA, Fordham MVP, Timmins DJ. Periurethral abscess complicating male gonococcal urethritis treated by surgical incision and drainage. Int J STD AIDS 2002; 13: 857–8. doi: 10.1258/095646202321020189

  3. Sharfi AR, Elarabi YE. The 'watering-can' perineum: presentation and management. Br J Urol 1997; 80: 933–6.

  4. Blaschko SD, Weiss DA, Odisho AY, Greene KL, Cooperberg MR. Proximal bulbar periurethral abscess. Int Braz J Urol 2013; 39: 137–8. doi: 10.1590/S1677-5538.IBJU.2013.01.17

  5. Mungadi IA, Ntia IO. Management of "watering-can" perineum. East Afr Med J 2007; 84: 283–6.

  6. Pandhi D, Reddy BSN. Watering can perineum–a forgotten complication of gonorrhoea. J Eur Acad Dermatol Venereol 2002; 16: 486–7.

  7. Ranjan P, Chipde SS, Prabhakaran S, Chipde S, Kapoor R. Endoscopic management of emphysematous periurethral and corporal abscess. Niger Med J 2013; 54: 209–10. doi: 10.4103/0300-1652.114579

  8. Salunke A, Nambi G, Manoharan A. Osteomyelitis of the pubic bone with vesicocutaneous–vesicovaginal fistula: a delayed complication of postcervical cancer radiotherapy. Niger Med J 2014; 55: 83–5. doi: 10.4103/0300-1652.128179

  9. Osoba AO, Alausa O. Gonococcal urethral stricture and watering-can perineum. Br J Vener Dis 1976; 52: 387–93. doi: 10.1136/sti.52.6.387

  10. Lee CY, Tsai HC, Lee SS, Chen YS. Concomitant emphysematous prostatic and periurethral abscesses due to Klebsiella pneumoniae: a case report and review of the literature. Southeast Asian J Trop Med Public Health 2014; 45: 1099–106.

  11. Al-Qahtani SM. Osteomyelitis of the pubic ramus was misdiagnosed as septic arthritis of the hip. West Afr J Med 2004; 23: 267–9. doi: 10.4314/wajm.v23i3.28137

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