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Combined Abdominoperineal Approach (Transperineal Urethral Advancement / Pull-Through)

The combined abdominoperineal approach — encompassing transperineal urethral advancement and the urethral pull-through technique — is a reconstructive strategy used primarily for posterior urethral strictures and distraction defects (most commonly after pelvic fracture urethral injury) and, in a separate context, for vesicourethral anastomotic stenosis (VUAS) after radical prostatectomy. The procedure can be performed entirely open or as a hybrid robotic-assisted abdominal + open perineal operation; the unifying principle is extensive distal urethral mobilization to bridge a long or hostile defect with a tension-free anastomosis.

Definition and Core Concept​

The fundamental principle is extensive mobilization of the distal (bulbar) urethra through a perineal incision, followed by excision of the scarred/obliterated urethral segment and advancement ("pull-through") of the healthy distal urethra proximally to achieve a tension-free, spatulated, mucosa-to-mucosa anastomosis with the proximal urethral stump (prostatic or bladder neck). Unlike standard end-to-end anastomotic urethroplasty, which relies on limited mobilization and direct re-approximation, the pull-through technique involves more aggressive circumferential mobilization of the bulbar urethra — sometimes up to the penoscrotal junction — to gain sufficient length to bridge larger defects.[1][2]

Indications​

  • Pelvic fracture urethral distraction defects (PFUDD): The most common indication. Stricture lengths typically 1.5–5 cm.[1][2][3]
  • Recalcitrant posterior urethral stenosis, including VUAS after radical prostatectomy where endoscopic treatments have failed.[4][5]
  • Failed prior urethroplasty or endoscopic management — 41–46% of patients in major series had prior failed repairs.[1][2]
  • Posterior urethral strictures with urethrorectal fistula — combined with fistula repair and tissue interposition.[6][7]
  • Pediatric / adolescent post-traumatic posterior urethral strictures.[8][9]
  • Defunctionalized bladder with recalcitrant stenosis — combined with cystectomy, neobladder formation, and urethral pull-through as a salvage orthotopic reconstruction.[10]

Open Surgical Technique — Step by Step​

Patient in exaggerated lithotomy position.[1][3][11]

  1. Perineal incision: Inverted-Y or midline perineal incision.[11]
  2. Exposure of the bulbar urethra: The bulbospongiosus muscle is divided and the bulbar urethra exposed circumferentially.
  3. Extensive distal urethral mobilization: The urethra is mobilized proximally and distally — critically, mobilization extends distally to the penoscrotal junction or beyond to gain maximal urethral length. This is the key distinguishing feature of the pull-through technique.[1][2]
  4. Transection and excision of scar: The strictured/obliterated segment is excised. In the "progressive" strategy, transection is first attempted at the proximal margin of the stenosis; if the proximal end is too deep, transection is performed at the distal margin and the scar is cored out to expose the proximal lumen.[3]
  5. Identification of the proximal urethral lumen: A sound or catheter passed through the suprapubic tract helps identify the proximal (prostatic) urethral opening.
  6. Tension-free anastomosis: The mobilized distal urethra is advanced and sutured to the proximal urethral stump with interrupted absorbable sutures over a catheter.[1][3][2]

Adjunctive maneuvers for gaining length​

When simple mobilization is insufficient, the following maneuvers are employed in a progressive, sequential fashion:[12][13][14]

  • Corporal body separation (splitting): Division of the intercorporal septum to allow the urethra to pass between the separated corpora — used in ~36% of posterior urethroplasties.[12][14]
  • Inferior pubectomy: Resection of the inferior margin of the pubic symphysis — used in ~13–32% of cases.[12][14][15]
  • Supracrural urethral rerouting: The urethra is rerouted around one side of the corpora cavernosa — used in ~2–5% of cases.[12][13][16]
  • Urethral suspension: Suturing the proximal urethra and surrounding tissues at multiple clock positions to optimize exposure for complex long-segment strictures (median 5.1 cm).[11]

Webster and Ramon described this progressive approach in 74 patients, achieving a 96% success rate by employing these maneuvers sequentially as needed.[13]

Open Pull-Through Outcomes​

SeriesnIndicationPrimary SuccessFinal SuccessMean F/U
Wang 2008 (modified pull-through)[1]113Post-traumatic posterior stricture96.5%100%48.5 mo
Yin 2011[2]76PFUDD89%100%42.5 mo
Sa 2021 (progressive TAU)[3]1,475PFUDD92.4%——
Fu 2009 (transperineal BPA)[12]301Posterior stricture (PFUDD)87.4%——
Koraitim 1995[17]78Post-traumatic posterior stricture95%—17 yr

Pull-Through vs. Standard End-to-End Anastomotic Urethroplasty​

  • More extensive mobilization — to the penoscrotal junction or beyond, vs limited mobilization in standard anastomotic repair.[1][2]
  • Technically simpler — proponents describe the pull-through as "less demanding and less time-consuming" because the well-mobilized urethra is simply advanced and sutured rather than spatulated and re-approximated under tension.[1][2]
  • Better suited for redo cases — extensive mobilization compensates for tissue loss from prior surgeries.[1]
  • Comparable or superior success rates in experienced hands (89–96.5% primary success).[1][2]

Combined Robotic Transabdominal + Open Transperineal Approach​

The combined approach addresses several limitations of a purely perineal route by using the robotic platform for the deep abdominal dissection and the perineum for distal urethral mobilization. AUA 2023 endorses both robotic and open reconstruction as options for recalcitrant VUAS / bladder-neck contracture (Conditional Recommendation, Grade C).[18]

Rationale for the robotic platform​

  • Superior visualization of deep pelvic anatomy proximal to the genitourinary diaphragm.[19]
  • Improved ergonomics for proximal suture placement at depths challenging through a perineal incision alone.[19]
  • Ability to perform adjunctive procedures — prostatectomy for residual obstructing prostate tissue, bladder-neck resitting, omental/gracilis flap interposition, and BMG placement — within the same setting.[5][20]
  • Particularly helpful in patients with narrow pelvic anatomy and long distances from perineal skin to proximal urethra.[19]

Cavallo combined-approach series[5]​

Multi-institutional series of 12 patients with complex posterior urethral stenosis (mean age 65.9 yr):

  • Robotic component: proximal abdominal dissection, scar excision, prostatectomy when needed (66.7%), and proximal suture placement.
  • Open transperineal component: bulbar urethral mobilization and advancement to meet the proximal stump.
  • Adjunctive procedures: corporal splitting (8.3%), gracilis muscle flap (33.3%).
  • Stenosis recurrence: 16.7% (2/12) at mean 187.5 days.
  • De novo SUI: 33.3%; 75% ultimately underwent AUS placement.
  • De novo ED: 16.7%.
  • The authors concluded this approach allows reconstruction of stenoses that would otherwise require urinary diversion.

Rodriguez step-by-step technique[4]​

When the healthy proximal urethra is insufficient to reach the bladder neck after robotic scar excision, the distal urethra is mobilized extensively through a perineal incision and advanced to create a tension-free vesicourethral anastomosis, preserving orthotopic voiding. Urinary incontinence is expected; staged AUS planned.

Robotic-assisted perineal approach (Unterberg)[19]​

The robotic platform is used through the perineal incision itself — standard perineal dissection, then the robot is docked to place proximal sutures with improved visualization. Setup time 15 min; 30–45 min for robotic suture placement. No urinary extravasation on postoperative VCUG in any of 10 patients.

Robotic-Assisted Posterior Reconstruction Outcomes​

SeriesnApproachPatencyDe Novo SUIAUS placementF/U
Zhang 2023[21]105Robotic (39% combined abdominoperineal)75.2%—28.6%18.7 mo
Shakir 2022 (TURNS)[22]32Robotic transabdominal75%15% (continent pts)—12 mo
Cavallo 2021[5]12Combined robotic + transperineal83.3%33.3%75%596 d
Bearrick 2022[23]21Robotic90–100% (non-radiated)—0–30% (non-radiated)—
Savun 2025[24]10 (robotic) vs 18 (open perineal)Robotic vs open perineal80% vs 77.8% (p=0.944)16.6% vs 100% (p=0.031)——

Robotic vs. open perineal — head-to-head (Savun 2025)​

  • Patency equivalent: 80% robotic vs 77.8% open (p=0.944).[24]
  • De novo incontinence dramatically lower with robotic: 16.6% vs 100% (p=0.031) — likely reflects the robotic approach's preservation of the sphincter mechanism by working from above rather than through the perineum.
  • Lower blood loss (100 vs 200 mL, p=0.001) and shorter hospital stay (3 vs 4 d, p=0.001).
  • Operative time comparable (150 vs 120 min, p=0.175).
  • Pelvic radiation and preoperative incontinence were associated with patency failure regardless of approach (p=0.007 and p=0.041).

The AUA guideline notes robotic patency 72.7–75% and open perineal 70–100%; the perineal approach carries an 83.3% incontinence rate vs 10% for retropubic open and lower rates for robotic.[18]

Impact of Pelvic Radiation​

Radiation history is the most important predictor of poor outcomes across all robotic series:

  • Bearrick: radiated patients had 80% anatomic success but only 60% functional success, with 80% requiring reintervention and 80% needing AUS — vs 100% anatomic and functional success in non-radiated BPH and prostatectomy groups.[23]
  • Zhang 2023 (n=105): 57.1% had prior radiation; overall reintervention rate 24.8%.[21]
  • TURNS (n=32): 50% had prior radiation; overall patency 75%.[22]

Complications​

  • Urinary incontinence: 0–8.5% in open pull-through series. In Sa 2021 (n=1,475), 8.5% had some degree of incontinence; Wang 2008 reported 100% continence. Combined robotic + transperineal series have higher de novo SUI (33.3%, Cavallo) reflecting the post-prostatectomy population.[1][3][5][17]
  • Erectile dysfunction (de novo): 1.6–5% in most open series. Most ED in PFUDD patients is attributable to the original injury — Koraitim reported impotence from injury in 15% but from surgery in only 2.5%.[1][2][3][17]
  • Recurrent stricture: 3.5–13% in open pull-through, almost always within the first 6–8 months. Most recurrences are manageable with endoscopic treatment or repeat urethroplasty.[1][2]
  • No chordee, penile shortening, or urethral diverticula reported in the major pull-through series.[1][2]

Special Contexts​

  • Combined with tissue interposition: For urethrorectal fistula, gracilis muscle flap or bulbocavernosus flap interposition is added to reinforce the repair and separate the urethral and rectal suture lines, achieving success rates of 91%.[6][18]
  • Pediatric population: Both pull-through and standard anastomotic techniques are effective in children, with overall success rates of 70–89% for primary repair and >90% after secondary procedures. Most pediatric PFUDDs can be addressed via a transperineal approach.[9][15][19]

Key Takeaways​

The combined abdominoperineal approach (transperineal urethral advancement / pull-through) is a versatile reconstructive option whose core advantage is gaining sufficient urethral length through aggressive distal mobilization to achieve a tension-free anastomosis. It is particularly valuable for longer defects and redo cases. When combined with a robotic transabdominal component, it achieves comparable patency rates to purely open surgery (~75–91%) with potential advantages in reduced de novo incontinence, less blood loss, and shorter hospitalization.[5][21][24] Anastomotic urethroplasty (whether by standard or pull-through technique) remains the gold standard for posterior urethral strictures, with success rates of 87–97% across large series.[12][13][17] Prior pelvic radiation remains the strongest predictor of poor outcomes regardless of approach.[23][24]

References​

1. Wang P, Fan M, Zhang Y, et al. "Modified Urethral Pull-Through Operation for Posterior Urethral Stricture and Long-Term Outcome." The Journal of Urology. 2008;180(6):2479-85. doi:10.1016/j.juro.2008.08.039

2. Yin L, Li Z, Kong C, et al. "Urethral Pull-Through Operation for the Management of Pelvic Fracture Urethral Distraction Defects." Urology. 2011;78(4):946-50. doi:10.1016/j.urology.2011.05.027

3. Sa Y, Wang L, Lv R, et al. "Transperineal Anastomotic Urethroplasty for the Treatment of Pelvic Fracture Urethral Distraction Defects: A Progressive Surgical Strategy." World Journal of Urology. 2021;39(12):4435-4441. doi:10.1007/s00345-021-03789-0

4. Rodriguez VI, Celis V, Sayegh A, et al. "Robotic Management of Complex Vesicourethral Anastomosis Stenosis With Transperineal Urethral Advancement: A Step-by-Step Technique." Urology. 2024;184:e256-e257. doi:10.1016/j.urology.2023.10.035

5. Cavallo JA, Vanni AJ, Dy GW, et al. "Clinical Outcomes of a Combined Robotic, Transabdominal, and Open Transperineal Approach for Anastomotic Posterior Urethroplasty." Journal of Endourology. 2021;35(9):1372-1377. doi:10.1089/end.2020.0973

6. Guo H, Sa Y, Fu Q, Jin C, Wang L. "Experience With 32 Pelvic Fracture Urethral Defects Associated With Urethrorectal Fistulas: Transperineal Urethroplasty With Gracilis Muscle Interposition." The Journal of Urology. 2017;198(1):141-147. doi:10.1016/j.juro.2017.01.071

7. Wang L, Song W, Lv R, et al. "Precise Treatment of Pelvic Fracture Urethral Injury Associated With Urethrorectal Fistula." BJU International. 2024;134(4):589-595. doi:10.1111/bju.16401

8. Netto NR. "The Surgical Repair of Posterior Urethral Strictures by the Transpubic Urethroplasty or Pull-Through Technique." The Journal of Urology. 1985;133(3):411-2. doi:10.1016/s0022-5347(17)49000-8

9. Sunay M, Karabulut A, Dadalı M, et al. "Single-Institution Outcomes of Open Reconstruction Techniques for Management of Pediatric and Adolescent Post-Traumatic Urethral Strictures." Urology. 2011;77(3):706-10. doi:10.1016/j.urology.2010.07.476

10. Patil MB, Hannoun D, Reyblat P, Boyd SD. "Total Bladder and Posterior Urethral Reconstruction: Salvage Technique for Defunctionalized Bladder With Recalcitrant Posterior Urethral Stenosis." The Journal of Urology. 2015;193(5):1649-54. doi:10.1016/j.juro.2014.11.102

11. Wang Y, Liu M, Jin C, et al. "Efficacy of Urethral Suspension-Assisted Urethral Anastomosis as a Treatment for Complex Long-Segment Posterior Urethral Stricture." World Journal of Urology. 2025;43(1):77. doi:10.1007/s00345-025-05442-6

12. Fu Q, Zhang J, Sa YL, Jin SB, Xu YM. "Transperineal Bulboprostatic Anastomosis in Patients With Simple Traumatic Posterior Urethral Strictures: A Retrospective Study From a Referral Urethral Center." Urology. 2009;74(5):1132-6. doi:10.1016/j.urology.2009.05.078

13. Webster GD, Ramon J. "Repair of Pelvic Fracture Posterior Urethral Defects Using an Elaborated Perineal Approach: Experience With 74 Cases." The Journal of Urology. 1991;145(4):744-8. doi:10.1016/s0022-5347(17)38442-2

14. Johnsen NV, Moses RA, Elliott SP, et al. "Multicenter Analysis of Posterior Urethroplasty Complexity and Outcomes Following Pelvic Fracture Urethral Injury." World Journal of Urology. 2020;38(4):1073-1079. doi:10.1007/s00345-019-02824-5

15. Wang L, Guo HL, Shu HQ, et al. "Surgical Treatment of Pelvic Fracture Urethral Distraction Defects in Boys: Which Approach Is Suitable?" Asian Journal of Andrology. 2020;22(3):292-295. doi:10.4103/aja.aja_64_19

16. Li H, Jin C, Li S, et al. "Urethral Rerouting Around One Side of Corpora Cavernosus via a Perineal Approach for Treating Long-Segment, Complex Posterior Urethral Strictures." World Journal of Urology. 2025;43(1):485. doi:10.1007/s00345-025-05825-9

17. Koraitim MM. "The Lessons of 145 Posttraumatic Posterior Urethral Strictures Treated in 17 Years." The Journal of Urology. 1995;153(1):63-6. doi:10.1097/00005392-199501000-00024

18. Wessells H, Morey A, Souter L, Rahimi L, Vanni A. "Urethral Stricture Disease Guideline Amendment (2023)." The Journal of Urology. 2023;210(1):64-71. doi:10.1097/JU.0000000000003482

19. Unterberg SH, Patel SH, Fuller TW, Buckley JC. "Robotic-Assisted Proximal Perineal Urethroplasty: Improving Visualization and Ergonomics." Urology. 2019;125:230-233. doi:10.1016/j.urology.2018.11.011

20. Liu W, Shakir N, Zhao LC. "Single-Port Robotic Posterior Urethroplasty Using Buccal Mucosa Grafts: Technique and Outcomes." Urology. 2022;159:214-221. doi:10.1016/j.urology.2021.07.049

21. Zhang TR, Alford A, Wang A, Zhao LC. "Robotic-Assisted Posterior Urethroplasty: Outcomes From 105 Men in a Single-Center Experience." Urology. 2023;181:167-173. doi:10.1016/j.urology.2023.05.062

22. Shakir NA, Alsikafi NF, Buesser JF, et al. "Durable Treatment of Refractory Vesicourethral Anastomotic Stenosis via Robotic-Assisted Reconstruction: A Trauma and Urologic Reconstructive Network of Surgeons Study." European Urology. 2022;81(2):176-183. doi:10.1016/j.eururo.2021.08.013

23. Bearrick EN, Findlay BL, Maciejko LA, et al. "Robotic Urethral Reconstruction Outcomes in Men With Posterior Urethral Stenosis." Urology. 2022;161:118-124. doi:10.1016/j.urology.2021.11.035

24. Savun M, Çolakoğlu Y, Özdemir H, et al. "Comparison of Open Perineal and Robot-Assisted Reconstruction in Vesicourethral Anastomotic Stenosis." World Journal of Urology. 2025;43(1):413. doi:10.1007/s00345-025-05808-w