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Transanal Minimally Invasive Repair (MITAR / TAMIS / R-TAMIS / TEM-TEO) for RVF and RUF

Transanal minimally invasive repair encompasses a family of techniques — MITAR (Minimally Invasive Transanal Repair), TAMIS (Transanal Minimally Invasive Surgery), R-TAMIS (Robotic TAMIS), and TEM / TEO (Transanal Endoscopic Microsurgery / Operation) — all sharing the principle of incisionless, sphincter-preserving, transanal access for fistula repair. They are emerging alternatives to traditional open repairs for rectovaginal fistula (RVF) and rectourethral fistula (RUF), but evidence remains at the small-retrospective-series level and outcomes vary significantly with fistula etiology and patient selection.[1][2][3]

For the dominant standard-of-care RUF approach, see Transperineal Gracilis Interposition for RUF. For first-line RVF repair see ERAF ± Sphincteroplasty. For broader RVF context see Transabdominal RVF Repair.

Terminology and Platform Distinctions​

PlatformAccessInstrumentationNotes
MITARParks' anal retractorStandard laparoscopic instrumentsSimplest setup; no specialized platform — Nicita 2017[1]
TAMISDisposable transanal port (e.g., GelPOINT Path)Standard lap instruments + insufflationWider working channel and stable pneumorectum[4]
R-TAMISGelPOINT Path + da VinciWristed robotic, tremor filtration, 3DBest dexterity and visualization[2][5]
TEM / TEORigid rectoscopeDedicated optics and instrumentsOriginal transanal-endoscopic platform; expensive equipment[3][6]

All share no external incision, sphincter preservation, and superior visualization vs traditional headlight-and-retractor transanal access.

MITAR Technique (Nicita 2017)​

The most thoroughly described purely-transanal RUF technique.[1]

Exclusions:

  • Fistula diameter > 1.5 cm
  • Active sepsis
  • Fecaluria
  • Radiation-induced fistulas (not studied)

Steps:

  1. Cystoscopy identifies the fistula; a 5F catheter is passed through the fistula from the bladder side as a guide.
  2. Lithotomy; Parks' anal retractor; laparoscopic instruments transanally.
  3. Lozenge-shaped rectal-wall incision parallel to the rectal axis around the fistula; carefully dissect fibrotic margins.
  4. Raise a healthy rectal-wall flap; identify underlying urothelium / fistula tract.
  5. Suture the fistulous tract closed on the urethral side with interrupted absorbable suture.
  6. Bladder leakage test to confirm watertight closure.
  7. Close the rectal wall with interrupted suture over the urethral repair.
  8. No electrocoagulation anywhere in the procedure (avoid thermal injury).

Outcomes (n = 12, median 21 mo):

  • 0% recurrence (12/12)
  • Median OR time 58 min (50–70)
  • Median LOS 1.5 d (1–4)
  • Early complications 8.3% (1 patient)
  • No colostomy required[1]

R-TAMIS Technique​

For RUF (Hebert 2021)​

  1. Prone jackknife.
  2. GelPOINT Path transanal port secured to a Lone Star retractor.
  3. Three robotic trocars; AirSeal insufflation with suction.
  4. Dissect the fistula and separate rectum from urethra.
  5. Excise the tract; close urethra and rectum independently in separate layers with absorbable suture.

Outcomes (n = 2, ≥ 15 mo): 0% recurrence; discharge POD 2; Foley out at 4 wk; intact at 3 mo on endoscopy at the time of diverting-loop-ileostomy reversal; no major morbidity.[2]

For RVF (Mohammed Salih 2025)​

R-TAMIS adapted for RVF on the da Vinci Xi: circumferential dissection of the tract; vaginal-wall closure with absorbable barbed suture, reinforced with fibrin sealant + acellular dermal mesh; rectal-wall closure. Initial report — discharged the next day, minimal pain, no major complications.[5]

TEM / TEO for RVF​

D'Ambrosio 2012 (largest TEM RVF series)​

ParameterResult
Patients13
Median follow-up25 mo
Mean OR time130 min (90–150)
Hospital stay5 d (3–8)
Recurrence1/13 (7.7%) — re-recurred after repeat TEM
Minor complications2/13 (septal hematoma, septal abscess)
Sphincter hypotonia2/13 (moderate)
[3]

Yuan 2020 — TES for mid-low RVF​

n = 17. Transanal route in 12 patients: 25% recurrence (3/12). Transvaginal route in 5: 0% recurrence. Median OR 75 min; no severe complications.[7]

Lapergola 2026 — fully transanal endoscopic for high post-anastomotic RVF​

TEO platform applied to large, high post-anastomotic RVF (population traditionally requiring transabdominal surgery). Six standardized steps with tension-free layered closure of both rectal and vaginal defects. Initial case — complete fistula closure, no recurrence at 2 yr. IDEAL stage 1 feasibility.[8]

TEM / TEO for RUF — Cautionary Note​

Serra-Aracil 2018:[6]

  • 8 patients TEO/TEM repair of RUF
  • 4 with biological mesh interposition — all 4 recurred
  • 4 without mesh — 2 had early recurrence
  • Overall success only 25% (2/8)
  • All 6 failures required salvage with transperineal gracilis interposition

Conclusion: TEO/TEM should not be the technique of choice for RUF, and biological mesh interposition is harmful.[6]

Adjacent Minimally Invasive Approaches (transabdominal)​

Distinct from purely-transanal but relevant for comparison:

  • Medina 2022 — robotic / laparoscopic transabdominal RUF repair (n = 15, 60% robotic): 100% success at 12 mo; median OR 264 min; EBL 175 mL; LOS 4 d; 9 postop complications; no intraoperative complications.[9]
  • Martín-Pérez 2021 — hybrid transanal MIS proctectomy + Turnbull-Cutait pull-through for radiated RUF (n = 3): all achieved fistula closure, all ileostomies reversed. Positioned as last-resort to avoid permanent stoma in irradiated patients.[10]

Comparative Summary​

TechniquePlatformFistulanSuccessOR timeLOSDiversion required
MITARParks' + lap instrumentsRUF (non-radiated)12100%58 min1.5 dNo[1]
R-TAMISGelPOINT + da VinciRUF (non-radiated)2100%NS2 dIleostomy (reversed)[2]
R-TAMISGelPOINT + da VinciRVF (benign)1100%NS1 dNo[5]
TEMRigid rectoscopeRVF1392%130 min5 dNo[3]
TESTEO/TEMRVF (mid-low, transanal)1275%75 min8 d42% ileostomy[7]
TEOTEORVF (high post-anastomotic)1100%NSNSNo[8]
TEO/TEMTEO/TEMRUF825%NSNSPre-existing[6]

Advantages​

  • Incisionless / sphincter-preserving — no perineal, abdominal, or transsphincteric incision; preserves sphincter integrity; avoids wound-related morbidity[1][3]
  • Rapid recovery — LOS 1–2 d for MITAR / R-TAMIS vs 5–7 d for transperineal gracilis[1][2]
  • Short OR time — MITAR ~58 min[1]
  • Diversion may be avoided — MITAR series demonstrated no patient required colostomy[1]
  • Enhanced visualization — magnified endoscopic / robotic 3D view vs traditional headlight + retractor[2][3]
  • No donor-site morbidity — no muscle harvest

Limitations​

  • Very small case series — largest MITAR n = 12; R-TAMIS reports n = 1–2. Evidence remains case-series / technical-feasibility level[1][2][5]
  • Strict patient selection — limited to small (< 1.5 cm), simple, non-radiated, non-septic, non-fecaluric fistulae[1][2]
  • No tissue interposition — unlike transperineal gracilis, no vascularized barrier between suture lines, may increase recurrence in complex cases[6]
  • Conflicting RUF results — MITAR 100% vs TEO/TEM 25%; technique and selection critical[1][6]
  • Biological mesh is harmful — Serra-Aracil 2018: 4/4 recurrence with mesh[6]
  • Short follow-up — most series 15–25 mo; long-term durability unknown[1][2]

Guideline Context​

ASCRS 2022 — endorectal advancement flap is the procedure of choice for most RVF (Strong, 1C; healing 41–78%). Minimally invasive approaches for fistula-in-ano (VAAFT and endoscopic techniques) have "reasonable short-term healing rates but unknown long-term healing and recurrence rates" (Weak, 2C). Transanal MIS for RUF and RVF is not specifically addressed in current major guidelines, reflecting early-stage evidence.[11]

RUF systematic review (Hechenbleikner 2013) — transanal approaches accounted for only 5.9% of RUF repairs vs 65.9% transperineal; high-volume centers uniformly favor transperineal repair with tissue interposition.[12]

Summary​

Transanal minimally invasive repair (MITAR / TAMIS / R-TAMIS / TEM / TEO) is a promising incisionless, sphincter-preserving approach for selected RVF and RUF. Best results so far: MITAR for small non-radiated RUF (100%, n = 12) and TEM for RVF (92%, n = 13). The techniques remain in early development with very small case numbers, strict selection criteria, and no long-term data. Consider primarily for simple, non-radiated fistulas in experienced centers. Transperineal gracilis interposition remains the standard of care for complex and radiation-associated RUF.

Videos​

Robotic TAMIS rectourethral fistula repair
Operative video paralleling the Hebert 2021 R-TAMIS technique (GelPOINT Path + da Vinci, prone jackknife)

References​

1. Nicita G, Villari D, Caroassai Grisanti S, et al. "Minimally invasive transanal repair of rectourethral fistulas." Eur Urol. 2017;71(1):133–138. doi:10.1016/j.eururo.2016.06.006

2. Hebert KJ, Naik N, Allawi A, et al. "Rectourethral fistula repair using robotic transanal minimally invasive surgery (TAMIS) approach." Urology. 2021;154:338. doi:10.1016/j.urology.2021.05.027

3. D'Ambrosio G, Paganini AM, Guerrieri M, et al. "Minimally invasive treatment of rectovaginal fistula." Surg Endosc. 2012;26(2):546–550. doi:10.1007/s00464-011-1917-5

4. Rottoli M, Di Simone MP, Poggioli G. "TAMIS-flap technique: full-thickness advancement rectal flap for high perianal fistulae performed through transanal minimally invasive surgery." Surg Laparosc Endosc Percutan Tech. 2019;29(4):e53–e56. doi:10.1097/SLE.0000000000000692

5. Mohammed Salih S, Zajicek J, Allawi A. "Same-day repair of recto-vaginal fistula using the robotic trans-anal minimally invasive technique — how we do it." J Laparoendosc Adv Surg Tech A. 2025. doi:10.1177/10926429251399211

6. Serra-Aracil X, Labró-Ciurans M, Mora-López L, et al. "The place of transanal endoscopic surgery in the treatment of rectourethral fistula." Urology. 2018;111:139–144. doi:10.1016/j.urology.2017.08.049

7. Yuan X, Chen H, Chen C, et al. "Minimally invasive treatment of mid-low rectovaginal fistula: a transanal endoscopic surgery study." Surg Endosc. 2020;34(9):3971–3977. doi:10.1007/s00464-019-07174-2

8. Lapergola A, Alicata F, Hag P, et al. "A fully transanal endoscopic approach for large post-anastomotic high rectovaginal fistulas: an IDEAL stage 1 technical note." Colorectal Dis. 2026;28(3):e70419. doi:10.1111/codi.70419

9. Medina LG, Sayegh AS, La Riva A, et al. "Minimally invasive management of rectourethral fistulae." Urology. 2022;169:102–109. doi:10.1016/j.urology.2022.05.060

10. Martín-Pérez B, Dar R, Bislenghi G, et al. "Transanal minimally invasive proctectomy with two-stage Turnbull-Cutait pull-through coloanal anastomosis for iatrogenic rectourethral fistulas." Dis Colon Rectum. 2021;64(2):e26–e29. doi:10.1097/DCR.0000000000001850

11. Gaertner WB, Burgess PL, Davids JS, et al. "The American Society of Colon and Rectal Surgeons clinical practice guidelines for the management of anorectal abscess, fistula-in-ano, and rectovaginal fistula." Dis Colon Rectum. 2022;65(8):964–985. doi:10.1097/DCR.0000000000002473

12. Hechenbleikner EM, Buckley JC, Wick EC. "Acquired rectourethral fistulas in adults: a systematic review of surgical repair techniques and outcomes." Dis Colon Rectum. 2013;56(3):374–383. doi:10.1097/DCR.0b013e318274dc87