PATIO Repair for Urethrocutaneous Fistula
The PATIO (Preserve the trAct and Turn It inside Out) repair is a minimally invasive technique for urethrocutaneous fistula (UCF) repair first described by Malone in 2009, achieving an overall pooled success rate of 88.2% across 356 patients in the 2023 systematic review.[1][2] Its defining innovation: the fistula tract is not excised — it is dissected free, preserved, and inverted into the urethral lumen where it acts as a one-way flap valve, sealing the fistula opening from the inside.[1]
For alternative UCF approaches see Simple Closure + Skin Advancement Flap and Double Dartos Flap; for broader context see the male fistula treatment atlas.
Concept and Mechanism
Traditional UCF repair excises the fistula tract and closes the urethral defect with sutures. PATIO takes the opposite approach:[1]
- Dissect the intact epithelialized fistula tract circumferentially from the surrounding tissue
- Invert (turn inside out) the tract into the urethral lumen
- Once inverted, the tract becomes a one-way flap valve — urine flowing through the urethra pushes the inverted tract flat against the urethral wall, sealing the fistula opening from inside
- The external skin end is closed with simple skin sutures
- No urethral sutures are placed — eliminating suture-line breakdown as the primary failure mechanism[1][3]
Indications
Based on Choudhury 2023 PRISMA SR (18 studies, 356 patients):[2]
- UCF of diverse etiologies — post-hypospadias repair, genital piercing, genitoplasty in cisgender or transgender patients
- Any location along the penile shaft, including coronal UCF (location does not affect success)
- Preferably < 5 mm — best for < 2 mm, good for 2–4 mm; success declines above 4 mm
- First-time and recurrent fistulas — Singh 2022: 100% success in PATIO after failed standard repair
- Multiple fistulas — can be performed simultaneously in the same setting
Contraindications / not recommended
- Large fistulas (> 5 mm) — tract may be too wide to form an effective flap valve; use conventional excision + waterproofing layer
- Very short fistula tracts — insufficient length to achieve adequate inversion
- Distal obstruction — exclude meatal stenosis or stricture before any UCF repair
- Fistulas requiring concurrent urethroplasty — not suitable for PATIO alone
Surgical Technique
Classic PATIO (Malone 2009)[1]
- Identification — pass a fine lacrimal probe through the tract to confirm course and length
- Stay suture — single fine absorbable stay suture through the skin edge of the fistula opening for traction
- Circumferential dissection — using the stay suture for traction, dissect the tract from surrounding subcutaneous tissue from skin surface down to the urethral wall, freeing the entire tract while keeping it intact and completely mobile
- Inversion — push the freed tract through its own urethral opening into the urethral lumen, using the stay suture to guide inversion. The tract now lies inside the urethra with its epithelialized surface facing the lumen
- Fixation (optional) — in the original technique, a traction suture passed through the meatus and taped to the glans maintained inversion during healing; removed at follow-up
- Skin closure — simple interrupted sutures; no urethral sutures
- No catheter — 4 of 5 original cases performed as day-cases with no urethral catheter[1]
Modified Variants
Modified PATIO — Rathod / Rajimwale 2017[4]
- Circumscribing skin incision around the fistula (rather than single stay suture); excise the skin around the fistula
- Dissect tract using the circumscribed skin edge for traction
- Invert tract into the urethra
- No fixation to the meatus
- Skin closure over the inverted tract
- 83% success (10/12) with 1 recurrence successfully treated by redo modified PATIO; average OR time 47 min (30–68)
Modified PATIO — Gigola / Mantovani 2024[3]
- Four stay sutures at the cardinal points around the fistula opening (more controlled, reproducible dissection)
- Invert tract into the urethra
- No fixation to the meatus — closure during introflection is maintained without traction, reflecting the flap-valve mechanism's efficacy
- 79.2% success (19/24) at median 3-yr follow-up; 1 recurrence successfully treated with redo modified PATIO
PATIO with ligation
Some authors ligate the base of the tract before or after inversion. The 2023 SR found no significant improvement:[2]
| Variant | Success |
|---|---|
| Inversion alone | 87.2% |
| Ligation + inversion | 86.9% |
| Ligation alone | 88.9% (P = 0.957 across groups) |
PATIO with waterproofing layer
Nerli 2011 used PATIO ± TVF in 4 of 10 patients — 100% success. However the 2023 SR found no significant improvement from adding a waterproofing layer (P = 0.622).[2][5]
Outcomes by Study
| Study | Year | n | Technique | Success | Follow-up | OR time |
|---|---|---|---|---|---|---|
| Malone (original) | 2009 | 5 (4 patients) | Classic PATIO | 100% | 18 mo (2–50) | NR[1] |
| Nerli | 2011 | 10 | PATIO ± TVF | 100% | NS | 22 min[5] |
| Rathod | 2017 | 12 (with f/u) | Modified PATIO | 83% | NS | 47 min[4] |
| Singh | 2022 | 26 | PATIO alone | 81% | 28 mo | NR[6] |
| Singh | 2022 | 8 | PATIO after failed standard | 100% | 28 mo | NR[6] |
| Gigola | 2024 | 24 (with f/u) | Modified PATIO (4 stay sutures) | 79.2% | 3 yr (median) | NR[3] |
| Choudhury pooled SR | 2023 | 356 | All PATIO variants | 88.2% | Variable | Variable[2] |
| Choudhury waterproofing meta | 2023 | Pooled | PATIO | 93.5% | Variable | Variable[7] |
Discrepancy between 88.2% and 93.5% reflects differences in study inclusion criteria and pooling methodology between the two Choudhury reviews.[2][7]
PATIO vs Standard Repair — Head-to-Head
Singh 2022 comparative study — the strongest direct comparison:[6]
| Outcome | Standard repair (n = 18) | PATIO (n = 26) | PATIO after failed standard (n = 8) |
|---|---|---|---|
| Success | 44% | 81% (P = 0.023) | 100% (P = 0.010) |
| Catheter required | Yes | Optional | Optional |
| Day-case feasible | Variable | Yes | Yes |
PATIO was significantly superior to standard repair (P = 0.023), and PATIO after a failed standard repair achieved 100% (P = 0.010). Failures in the PATIO group were concentrated in the early learning curve.[6]
PATIO vs Other UCF Techniques
| Technique | Pooled success | Catheter | Additional incision | Best indication |
|---|---|---|---|---|
| PATIO | 88–93.5% | No | No | Small (< 4 mm), any location[1][2] |
| Tunica vaginalis flap | 94.3% | Usually yes | Scrotal incision | Recurrent, proximal, large[7] |
| Scrotal dartos flap | 94.6% | Usually yes | Penoscrotal incision | Recurrent, midshaft[7] |
| De-epithelialized skin advancement flap | 95.7% | Optional | No | Simple, coronal / midshaft[8] |
| Simple closure | 73.2% | Optional | No | Small shaft fistulas[7] |
Effect of Fistula Size on PATIO Outcomes
Choudhury 2023 SR granular size-outcome data:[2]
| Fistula size | Success | Recommendation |
|---|---|---|
| < 2 mm | Best | Ideal for PATIO |
| 2–4 mm | Good | Appropriate |
| 4–5 mm | Declining | PATIO possible but consider alternatives |
| > 5 mm | Not recommended | Use TVF, scrotal dartos, or skin flap |
Location along the penile shaft did not affect PATIO success — coronal, subcoronal, midshaft, and proximal had comparable outcomes.[2]
Advantages
- No urethral sutures — eliminates suture-line breakdown as a failure mechanism[1]
- Day-case procedure — 4 of 5 original cases performed as day-cases[1]
- No catheter required — optional; can be omitted, reducing morbidity and hospitalization[1][2]
- Short operative time — 22–47 min, significantly shorter than techniques requiring flap harvest and tunneling[4][5]
- Technically simple — described as "easy to perform" by multiple authors; short learning curve, though early failures attributed to limited experience[4][6]
- Tissue-sparing — no excision, no distant tissue mobilized; preserves options for future surgery. Particularly valuable in hypospadias cripples with limited tissue reserves[2]
- Repeatable — redo PATIO feasible with good success[3][4]
- Multiple fistulas simultaneously in the same setting[2]
- Does not preclude other techniques — can be supplemented with a waterproofing layer; does not prevent future use of other approaches[1]
Limitations
- Lower success than TVF or scrotal dartos — 88.2% vs 94.3% / 94.6%; second-tier for recurrent or complex fistulas[2][7]
- Size-dependent outcomes — best for < 2 mm; declines > 4 mm; not recommended > 5 mm[2]
- Limited long-term data — most series median follow-up 18–36 mo; longest in Malone series was 50 mo for a single patient[1]
- Learning curve — early failures in Singh series attributed to limited experience[6]
- Recurrence ~12–21% — superior to simple closure (44–56% failure) but higher than the best-performing techniques[3][6]
- Theoretical intraluminal-tissue concern — the inverted tract creates a small intraluminal projection. No obstructive complications reported, but long-term effects on urethral caliber are unknown.
Postoperative Management
- Catheterization optional — 4 of 5 original cases had no catheter; when used, typically removed the next morning[1]
- Hospitalization — most cases day-cases; overnight observation if caudal anesthetic is used[1]
- Traction suture removal at first follow-up (classic technique only); modified techniques omit fixation[3][4]
- Activity restrictions — standard post-hypospadias precautions (avoid straddle activities, swimming) for 2–4 wk
- Follow-up — clinical assessment + voiding-stream observation at 2–4 wk, then 3, 6, 12 mo
Evidence-Based Algorithm — Where PATIO Fits
- Small fistula (< 4 mm), first-time repair → PATIO first-line (tissue-sparing, day-case, no catheter)[1][2]
- Small fistula, alternative to skin-advancement flap → both reasonable (skin-flap success 95.7%, PATIO 88–93.5%)[7][8]
- Failed standard repair → PATIO as salvage (100% in Singh)[6]
- Recurrent, large (> 4 mm), or multiply-operated → TVF or scrotal dartos flap (94–95%)[7]
- Hypospadias cripples with limited tissue → PATIO as tissue-sparing first step, with TVF or BMG in reserve[2]
Technical Pearls
- Adequate tract length — fistula tract must be long enough to create an effective flap valve when inverted; very superficial fistulas with minimal tract length may not be suitable[1]
- Complete circumferential dissection — tract must be freed completely to allow full inversion without tension[1]
- Gentle tissue handling — avoid crushing or cauterizing the tract; its epithelial lining is the functional element that creates the valve seal[1]
- Four stay sutures (Gigola modification) provide more controlled dissection than a single stay suture[3]
- Meatal fixation is optional — Gigola and Rathod modifications demonstrate that the inverted tract maintains position without fixation, simplifying the procedure[3][4]
- Exclude distal obstruction — meatal calibration ± cystoscopy before repair[1]
- Wait ≥ 6 months after the last surgery to allow tissue maturation
- Redo PATIO is feasible before escalating to more complex techniques[3][4]
Key Takeaways
- Tissue-sparing, no urethral sutures, day-case, no catheter — uniquely minimal among UCF repairs.
- 88.2% pooled success for small fistulas across 356 patients (Choudhury 2023 SR).
- Best for fistulas < 4 mm; not recommended for > 5 mm or those requiring concurrent urethroplasty.
- 100% success when used after a failed standard repair (Singh 2022) — strong salvage option.
- Inferior to TVF / scrotal dartos for recurrent or complex fistulas — those remain first-line for > 4 mm or recurrent cases.
References
1. Malone PR. "Urethrocutaneous fistula: preserve the tract and turn it inside out — the PATIO repair." BJU Int. 2009;104(4):550–554. doi:10.1111/j.1464-410X.2009.08350.x
2. Choudhury P, Phugat S, Jain V, et al. "Defining the indications of PATIO technique for urethrocutaneous fistula repair." J Indian Assoc Pediatr Surg. 2023;28(5):375–386. doi:10.4103/jiaps.jiaps_25_23
3. Gigola F, Mantovani A, Zulli A, et al. "Modified PATIO technique for urethrocutaneous fistula after hypospadias repair: experience from a tertiary referral hospital." J Pediatr Urol. 2024;20(3):437.e1–437.e6. doi:10.1016/j.jpurol.2024.01.031
4. Rathod K, Loyal J, More B, Rajimwale A. "Modified PATIO repair for urethrocutaneous fistula post-hypospadias repair: operative technique and outcomes." Pediatr Surg Int. 2017;33(1):109–112. doi:10.1007/s00383-016-3983-1
5. Nerli RB, Metgud T, Bindu S, et al. "Solitary urethrocutaneous fistula managed by the PATIO repair." J Pediatr Urol. 2011;7(2):166–169. doi:10.1016/j.jpurol.2010.04.016
6. Singh J. "Urethrocutaneous fistula repair following hypospadias surgery using the PATIO technique for small fistulae: a single centre experience." J Pediatr Urol. 2022;18(1):60.e1–60.e7. doi:10.1016/j.jpurol.2021.11.014
7. Choudhury P, Saroya KK, Jain V, et al. "'Waterproofing layers' for urethrocutaneous fistula repair after hypospadias surgery: evidence synthesis with systematic review and meta-analysis." Pediatr Surg Int. 2023;39(1):165. doi:10.1007/s00383-023-05405-1
8. Santangelo K, Rushton HG, Belman AB. "Outcome analysis of simple and complex urethrocutaneous fistula closure using a de-epithelialized or full thickness skin advancement flap for coverage." J Urol. 2003;170(4 Pt 2):1589–1592. doi:10.1097/01.ju.0000084624.17496.29