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Primary Repair (No Tissue Interposition) for USF

Primary repair of urosymphyseal fistula (USF) — defined as fistula tract excision and urinary tract closure without interposition of a vascularized tissue flap — carries the highest recurrence rate (30%) among all surgical approaches and an 18% 90-day sepsis rate (Escandón 2026 comparative analysis).[1] It is the least favorable definitive surgical strategy and is generally discouraged when any flap option is available.

For the preferred flap-based alternative see Organ-Sparing USF Repair with Interposition Flap; for the most extensive bladder-sparing alternative see Salvage Prostatectomy for USF; for the broader decision framework see USF / PPF Bladder-Sparing Approaches.

Definition​

"Primary repair" in the USF literature specifically refers to surgical closure of the fistula tract and urinary defect without the addition of a well-vascularized tissue interposition flap (omental, VRAM, rectus abdominis muscle, or gracilis). The operation still includes:

  • Pubic-symphysis debridement / pubectomy
  • Fistula-tract excision
  • Multilayer urinary-tract closure

The defining difference vs flap-based repair: no biological barrier between the urinary-tract closure and the debrided bone bed.[1][2]

Escandón 2026 — The Key Comparative Dataset​

The only direct comparative analysis of primary repair vs flap-based reconstruction for USF (n = 56, multicenter, minimum 3-mo follow-up):[1]

  • Primary repair: n = 11 (19.6%)
  • Omental flap: n = 34 (60.8%)
  • VRAM flap: n = 11 (19.6%)

Patients with distal urethral obstruction, radiation cystitis, or non-viable sphincter were triaged to anterior exenteration with flap transfer (excluded from primary-repair group).

OutcomePrimary repair (n = 11)Omental flap (n = 34)VRAM flap (n = 11)P
90-day sepsis18%3%27%0.041
Fistula recurrence30%Lowest27.3%0.04
OR for recurrence vs primary (MVA)Reference0.012NS0.011

Key findings: primary repair had the highest fistula-recurrence rate (30%); the omental flap reduced recurrence-odds by 98.8% vs primary repair on MVA (OR 0.012, P = 0.011); VRAM did not achieve statistical significance vs primary for recurrence reduction; primary repair's 18% sepsis rate was intermediate.

Why Primary Repair Fails — Pathophysiologic Rationale​

1. Irradiated tissue has impaired healing capacity​

93% of USF patients have a history of pelvic radiation.[3] Radiation causes obliterative endarteritis, fibrosis, and hypoxia. Suture lines in irradiated tissue are prone to dehiscence — without interposition of non-irradiated tissue, the closure relies entirely on compromised tissue.[2][4]

2. Persistent osteomyelitis creates an ongoing infectious nidus​

Active infection in 80% of pubic bone specimens at surgery.[5] Even with adequate debridement the bone-urinary interface remains hostile. A vascularized flap creates a biological barrier, delivers antibiotic-laden blood flow, and fills dead space — all reduce recurrent infection and fistulization.[2][5]

3. Dead space promotes fluid collection and reinfection​

Pubectomy creates a significant retropubic cavity. Without a flap to obliterate dead space, fluid collections (seroma, hematoma, urinoma) accumulate, become secondarily infected, and erode into the urinary closure → fistula recurrence.[6][7]

4. Urinary tract is under constant hydrostatic pressure​

Unlike many fistula repairs where the organ can be rested (e.g., bowel diversion for RUF), the urinary closure faces continuous hydrostatic pressure even with catheter drainage. A flap provides a second layer of protection against pressure-related dehiscence.[2]

When Primary Repair Has Been Attempted​

Despite inferior outcomes, primary repair has been used in ~19.6% of USF surgeries:[1]

  • Radiation-naïve patients — tissue quality fundamentally different; healing capacity preserved. Conservative management still fails in 72% of radiation-naïve patients per Patel SR, but surgical outcomes are better and the rationale for interposition is less compelling (though still recommended)[3]
  • Small, well-defined fistula tracts — narrow, discrete tract with minimal surrounding tissue destruction. Escandón data show even these "favorable" cases recur at 30%[1]
  • Flap-harvest infeasibility — prior abdominal surgery, prior flap harvest, or anatomy precluding mobilization of omental / VRAM / rectus / gracilis flap. Consider perivesical fat rotational flap as a salvage alternative before defaulting to no-flap repair[1]
  • As a staged bridge — initial attempt with planned flap-based revision if it fails — increasingly discouraged because failed repairs create additional scarring and tissue destruction making subsequent reconstruction more difficult[2][8]

Surgical Technique​

Step 1 — Exposure​

  • Midline lower abdominal incision
  • Enter retropubic space (space of Retzius)
  • Identify the fistula tract from prostatic urethra / bladder neck to symphysis

Step 2 — Pubic-symphysis debridement​

  • Resect all infected and necrotic bone with rongeurs and curettes until healthy bleeding bone margins
  • Bone cultures essential (95.5% discordance with preoperative urine cultures)[5]
  • Bone pathology to exclude malignancy

Step 3 — Fistula-tract excision​

  • Complete tract excision back to healthy tissue
  • Debride urinary-tract defect edges to fresh, bleeding margins

Step 4 — Urinary-tract closure​

  • Close defect in multiple layers with absorbable suture
  • Confirm watertight closure
  • 18–20 Fr urethral catheter or suprapubic tube for postoperative drainage

Step 5 — Drains and closure​

  • Closed-suction retropubic drains
  • Layered wound closure
  • No tissue flap interposed — defining feature of primary repair

Postoperative Management​

  • Catheter drainage 2–4 wk
  • Cystogram before catheter removal to confirm no leak
  • Culture-directed antibiotics for osteomyelitis — typically 6–8 wk based on intraoperative bone cultures[5][9]
  • Close surveillance for recurrence — recurrent pain, drainage, fever

Outcomes in Context​

ApproachFistula recurrence90-d sepsisAdvantagesDisadvantages
Primary repair (no flap)30%18%Shortest OR, no donor-site morbidity, simplest techniqueHighest recurrence, no dead-space obliteration, no tissue barrier[1]
Omental flapLowest3%Best safety profile, lowest sepsis and recurrence, excellent dead-space obliterationRequires laparotomy / mobilization, may be unavailable after prior surgery[1]
VRAM flap27.3%27%Large tissue volume, reliable pedicleHighest sepsis rate, 16.7% donor-site hernia rate, high recurrence[1]
Rectus muscle-only flap (Kaufman / Vanni)0% (n = 4)NROrgan-sparing, no bowel surgery, adjacent to operative fieldVery small series, limited follow-up[7]

Impact of Radiation​

Eswara 2015 (Washington University) — among patients undergoing surgical fistula repair, radiation was associated with:[4]

  • Higher rates of repair failure (P = 0.0002)
  • Higher postsurgical incontinence (P < 0.001)
  • More permanent urinary diversion (72% irradiated vs 7% non-irradiated at final follow-up)

Raup 2016 — pelvic radiation was associated with persistent urinary incontinence and decreased QoL after gracilis flap interposition.[10]

Together these data argue strongly against no-flap repair in irradiated patients — the already-compromised healing is further undermined by the absence of vascularized tissue.

Conservative (Non-Surgical) Management​

Conservative management — catheter drainage, antibiotics, wound care — is essentially the least-invasive "primary" management approach and has an extremely high failure rate:

  • Irradiated patients: 96% failure[3]
  • Radiation-naïve patients: 72% failure[3]
  • Bugeja 2016: 1/16 (6.3%) successful[6]
  • Andrews 2021: "Conservative management will not provide symptom resolution"[5]

USF is fundamentally a surgical disease requiring definitive operative intervention.

Minimally Invasive Alternatives​

Robotic-assisted repair with holmium laser pubic debridement​

  • Hebert 2022 (n = 4) — robotic dissection of fistula, holmium laser symphyseal debridement (2 J, 50 Hz), GU reconstruction, antibiotic beads in symphyseal defect, interposition flap "if available"; no fistula recurrences at 7–16 mo.[11]
  • Navaratnam 2019 (n = 12) — robot-assisted cystectomy with holmium laser debridement; 91.7% (11/12) complete resolution at median 29 mo; median OR 270 min; LOS 5 d.[12]

Specific indications for laser debridement vs open pubectomy: (1) prior sacral insufficiency fractures (open pubectomy risks pelvic ring instability), (2) mild osteomyelitis amenable to debridement rather than resection.[11]

Cyanoacrylic glue occlusion​

  • Muto 2005 — n = 13 urinary fistulas; 11/13 successful at median 35 mo
  • Fails in fistulas > 1 cm wide
  • Not specifically studied in USF with osteomyelitis[13]

Expert Consensus​

The evidence converges on a clear message: primary repair without tissue interposition is inferior to flap-based repair for USF and should generally be avoided when a flap option is available.

  • Campbell & Vanni 2022 — "meticulous surgical dissection and interposition of healthy muscle allow for fistula repair in a high proportion of appropriately selected patients" — tissue interposition is a fundamental principle, not an optional adjunct.[2]
  • Escandón 2026 — omental flap reduces recurrence odds by 98.8% vs primary repair (OR 0.012, P = 0.011).[1]
  • Moring 2023 — "many of the less invasive and conservative options ultimately lead to cystectomy"; cystectomy + urinary diversion is "a safe and viable option in select irradiated patients with the goal to improve quality of life."[8]
  • The principle of tissue interposition in irradiated fistula repair is well-established across all types (RUF, VVF, USF) — primary repair without interposition is a violation of this principle.[2][4][10]

When Primary Repair Might Still Be Considered​

Despite unfavorable data, narrow circumstances may justify it:

  1. Radiation-naïve patients with small, well-defined fistulas and preserved tissue quality — healing capacity fundamentally different; outcomes better (though interposition still preferred)
  2. No flap source available — prior abdominal surgery, prior flap harvest, anatomic constraints. First explore alternatives (perivesical fat, gracilis) before defaulting to no-flap repair
  3. Bridge to definitive surgery — septic, malnourished, or poor-PS patients not candidates for major reconstruction at presentation; primary repair + catheter drainage may temporize while optimization occurs
  4. Patient preference — declines morbidity of major reconstruction or cystectomy, accepting higher recurrence risk

Counsel patients extensively about the 30% recurrence rate and the high likelihood of eventually requiring either flap-based revision or cystectomy with urinary diversion, particularly in the setting of prior pelvic radiation.[1][4]

Key Takeaways​

  • Highest recurrence (30%) and intermediate sepsis (18%) of all USF surgical approaches in the only direct comparative analysis (Escandón 2026).
  • Omental flap reduces recurrence odds by 98.8% vs primary repair — argues strongly for flap interposition whenever feasible.
  • Failure is mechanistically inevitable in irradiated tissue without a vascularized barrier — radiation-impaired healing + persistent osteomyelitis + dead space + hydrostatic urinary pressure.
  • Conservative management fails in 96% of irradiated patients — USF is a surgical disease.
  • Reserve primary repair for radiation-naïve patients with favorable anatomy, when no flap is feasible despite exploring alternatives, as a temporizing bridge, or by informed patient preference.

References​

1. Escandón JM, Kreutz-Rodrigues L, Fadel AE, et al. "Optimizing flap selection for urosymphyseal fistula repair: a comparative analysis of surgical outcomes." Microsurgery. 2026;46(3):e70197. doi:10.1002/micr.70197

2. Campbell JG, Vanni AJ. "Complex lower genitourinary fistula repair: rectourethral fistula and puboprostatic fistula." Urol Clin North Am. 2022;49(3):553–565. doi:10.1016/j.ucl.2022.04.012

3. Patel N, Mehawed G, Dunglison N, et al. "Uro-symphyseal fistula: a systematic review to inform a contemporary, evidence-based management framework." Urology. 2023;178:1–8. doi:10.1016/j.urology.2023.05.002

4. Eswara JR, Raup VT, Heningburg AM, Brandes SB. "Pelvic radiation is associated with urinary fistulae repair failure and need for permanent urinary diversion." Urology. 2015;85(4):932–936. doi:10.1016/j.urology.2014.11.051

5. Andrews JR, Hebert KJ, Boswell TC, et al. "Pubectomy and urinary reconstruction provides definitive treatment of urosymphyseal fistula following prostate cancer treatment." BJU Int. 2021;128(4):460–467. doi:10.1111/bju.15333

6. Bugeja S, Andrich DE, Mundy AR. "Fistulation into the pubic symphysis after treatment of prostate cancer: an important and surgically correctable complication." J Urol. 2016;195(2):391–398. doi:10.1016/j.juro.2015.08.074

7. Kaufman DA, Browne BM, Zinman LN, Vanni AJ. "Management of radiation anterior prostato-symphyseal fistulas with interposition rectus abdominis muscle flap." Urology. 2016;92:122–126. doi:10.1016/j.urology.2016.01.029

8. Moring N, Barrett S, Peterson AC, Inouye BM. "Pelvic extirpative surgery for the 'end-stage irradiated bladder'." Cancers. 2023;15(17):4238. doi:10.3390/cancers15174238

9. Ross JJ, Hu LT. "Septic arthritis of the pubic symphysis: review of 100 cases." Medicine (Baltimore). 2003;82(5):340–345. doi:10.1097/01.md.0000091180.93122.1c

10. Raup VT, Eswara JR, Geminiani J, et al. "Gracilis muscle interposition flap repair of urinary fistulae: pelvic radiation is associated with persistent urinary incontinence and decreased quality of life." World J Urol. 2016;34(1):131–136. doi:10.1007/s00345-015-1597-1

11. Hebert KJ, Boswell TC, Bearrick E, et al. "Robotic puboprostatic fistula repair with holmium laser pubic debridement." Urology. 2022;160:228. doi:10.1016/j.urology.2021.10.019

12. Navaratnam A, Faraj K, Rose K, et al. "Robot assisted cystectomy with holmium laser debridement for osteomyelitis of the pubic symphysis with urinary fistula." Urology. 2019;134:124–134. doi:10.1016/j.urology.2019.08.049

13. Muto G, D'Urso L, Castelli E, Formiconi A, Bardari F. "Cyanoacrylic glue: a minimally invasive nonsurgical first line approach for the treatment of some urinary fistulas." J Urol. 2005;174(6):2239–2243. doi:10.1097/01.ju.0000181809.51544.20