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Ureterolysis for Retroperitoneal Fibrosis

Ureterolysis frees the ureter from encasing fibrotic tissue; intraperitoneal transposition and omental wrapping may be added to reduce re-entrapment.[1][11] For refractory extrinsic obstruction from retroperitoneal fibrosis (RPF), ureterolysis can restore drainage. After pelvic radiation or surgery, assess for an intrinsic ischemic stricture that may require reconstruction beyond simple release.[23] For the underlying disease, classification, medical therapy, and follow-up framework, see Retroperitoneal Fibrosis (RPF).

The surgical management of RPF encompasses three domains: (1) temporary urinary drainage (ureteral stenting, percutaneous nephrostomy), (2) definitive ureterolysis (open, laparoscopic, robotic), and (3) vascular surgery for associated inflammatory aortic aneurysms. For idiopathic or IgG4-related RPF, disease-directed medical therapy treats the fibro-inflammatory process, while drainage or ureterolysis relieves obstruction. Secondary RPF requires treatment of its cause. Ureterolysis does not prevent inflammatory relapse or systemic manifestations.[3][2]

Temporary Urinary Drainage — Ureteral Stenting vs PCN​

Urgent drainage is indicated for an infected obstructed system, acute kidney injury, or threatened renal function. In idiopathic or IgG4-related RPF, moderate-to-severe obstruction generally requires prompt stenting or PCN before immunosuppression; mild obstruction with stable function may permit closely monitored medical treatment.[3][24] Both ureteral stenting and percutaneous nephrostomy (PCN) are initial drainage options.[4][5] In a retrospective cohort of 30 patients with 44 obstructed units, complication rates were 21% with PCN and 17.9% with stenting (P = 0.79).[4]

  • Ureteral stenting was the most frequent intervention (38%) in a review of nine retrospective RPF series; it is commonly attempted first when drainage is needed.[6][4] Among 32 obstructed units in which stenting was attempted first, placement succeeded in 25; 20 of those 25 (80%) were managed with stenting alone throughout the study period.[6][4]
  • PCN is used when stenting fails or when the obstruction is too severe for retrograde access. Over time, both techniques may be needed in the same patient, and they complement each other.[4]
  • The treatment goal is freedom from stent or nephrostomy combined with withdrawal of glucocorticoids and preservation of renal function. In a retrospective series of 52 patients with idiopathic RPF and hydronephrosis initially managed without ureterolysis, obstruction resolved in 36 (69%) during medical management with temporary renal drainage as needed; median stent duration was 16 months.[7][2]

Ureterolysis — Indications and Technique​

Ureterolysis is generally considered when obstruction persists despite medical treatment and drainage, stents cause severe symptoms, or nephrostomy dependence continues; selected patients may choose earlier surgery after multidisciplinary assessment.[8][1]

Indications​

Based on the available literature, ureterolysis should be considered in:[8][1][3]

  • Stent failure. Persistent obstructive hydronephrosis despite stenting (40% in one series; severe stent symptoms were slightly more common at 44%).[8]
  • Severe stent-related symptoms. Intractable pain, recurrent infections, or quality-of-life impairment from chronic stenting (44% of cases).[8]
  • Nephrostomy dependence. Inability to transition from PCN to stent or stent-free status (10% of cases).[8]
  • Medication intolerance or failure. Inability to tolerate glucocorticoids or immunosuppressants, or lack of radiographic response.[7]
  • Diagnostic uncertainty. When tissue biopsy is needed to exclude malignancy, ureterolysis can serve a dual therapeutic and diagnostic purpose.[2]

Technique​

The procedure centers on ureteral release; transposition, wrapping, and biopsy depend on anatomy and diagnostic need:[2][1][11][13][9]

  • Free the ureters from the fibrotic tissue. In a laparoscopic technique, dissection starts near the renal hilum or below the iliac vessels, where the ureter is usually outside the fibrotic field, and proceeds toward the involved segment with blunt and sharp dissection; electrocautery is minimized near the ureter, major vessels, and periaortic nerve plexus, and a vessel loop around the freed ureter aids traction.[21] Preserve periureteral vascular tissue during long-segment release: three ureteric injuries occurred in the 50-patient open series, including one post-radiation injury followed by failed repair and dialysis dependence.[8]
  • Intraperitoneal transposition of the mobilized ureter.
  • Omental wrapping can separate the freed ureter from the fibrotic bed, but its independent effect on re-encasement remains uncertain.[8] One described technique divides and mobilizes a bifurcated omental flap while preserving its right and left gastroepiploic arterial supply, then wraps it 360 degrees around the ureter and secures it with fine absorbable sutures.[22]
  • Intraoperative biopsy provides tissue when the diagnosis remains uncertain or no adequate preoperative sample is available; Keehn's robotic series used frozen section to guide whether ureterolysis proceeded.[9][3]

Approaches — Open vs Laparoscopic vs Robotic​

Different operative cohorts vary in selection, prior treatment and outcome definitions.

Open Ureterolysis​

The traditional approach. In a prospective series of 50 patients, 48/50 (96%) were stent-free at 3 months and 47/50 (94%) at 12 months; 11/50 patients (22%) had an additional procedure during the index operation, including seven contralateral nephrectomies performed with unilateral ureterolysis.[8] A separate patient underwent nephrectomy six months later after recurrent pan-ureteric obstruction.[8] Median hospital stay was 8 days, median blood loss 390 mL, and serious complications (Clavien III–IV) occurred in 12%.[8] Overall glomerular filtration rate improved by a median of +6% at 1 year (interquartile range −4% to +22%, p < 0.05) in this series, with larger gains in the stent-failure subgroup noted below.[8] A separate 100-patient NSQIP analysis of ureterolysis found 12% 30-day complications, predominantly grades I–II.[10]

Laparoscopic Ureterolysis​

In a retrospective University of Michigan comparison (22 patients, 25 procedures), success per affected ureter was 87.5% after open ureterolysis (mean follow-up 30 months) and 93.8% after laparoscopic ureterolysis (mean follow-up 24 months; P = 1.0); laparoscopy was associated with a shorter mean hospital stay (2.1 vs 5.9 days, P = .004).[11] In a single-institution comparison of 70 patients, laparoscopy was associated with fewer transfusions in the primary idiopathic RPF subgroup (3.7% vs 13.7%, P = .007); among all 34 laparoscopic patients, including those with secondary RPF, 17.6% were converted to open surgery.[12] In a tertiary-center series (13 patients, 23 renal units), success, defined as no repeat ureteral stent placement during follow-up, was 11/12 renal units (92%) after open and 10/11 (91%) after laparoscopic ureterolysis; median follow-up was 110.5 and 52 months, respectively. No statistically significant difference in complication rates was detected, and laparoscopy was associated with shorter hospitalization and faster return to normal activities. In the seven-patient laparoscopic group, one ureteral injury required ureteroureterostomy and one grade IIIa urinoma required percutaneous drainage.[13]

Robot-Assisted Ureterolysis​

In a series of 17 patients and 21 renal units, no unit remained obstructed at mean 20.5 months, but 3 patients required secondary procedures and one enterocutaneous fistula required bowel resection.[9] An earlier pilot series demonstrated robotic biopsy and omental wrapping.[14] In a 2026 prospective single-center series of 16 patients and 21 attempted renal-unit procedures, four procedures (19%) were aborted because safe ureteral dissection was not feasible or vascular injury risk was unacceptable; 11/17 completed units (64%) were stent-free at 12 months.[25]

Key Considerations​

  • Concomitant procedures were performed in 11/50 patients (22%) in the open series: seven contralateral nephrectomies, three ureteral reconstructions, and one aneurysm repair.[8] The NSQIP study recorded six concomitant urologic reconstructive procedures among 100 ureterolysis cases; the cohorts and procedure definitions cannot be pooled as a reintervention rate.[8][10]
  • Empiric contralateral ureterolysis may not be necessary. In one series, none of 13 patients who underwent unilateral ureterolysis developed contralateral disease progression.[9] Other authors recommend bilateral ureterolysis even when disease is unilateral at surgery, citing the 50-patient open series discussed below.[8] Neither series is a comparative trial of unilateral versus bilateral dissection, so the extent of ureterolysis remains a judgment call rather than a settled rule.
  • Tissue diagnosis is important when malignancy is possible. Frozen section may guide the operation, but equivocal findings require adequate permanent pathology and, when appropriate, immunophenotyping; frozen section alone cannot reliably exclude every lymphoma.[9]

Decision Framework — Medical + Stenting vs Ureterolysis​

The decision between prolonged medical management with stenting and ureterolysis in RPF-related ureteral obstruction lacks formal consensus, but the available evidence provides a practical framework.[3][1]

Initial Approach — Medical Therapy + Temporary Stenting​

For idiopathic or IgG4-related RPF with obstruction, reviews generally favor temporary stenting or PCN plus disease-directed immunosuppression, with ureterolysis considered when obstruction persists or drainage is intolerable; secondary RPF requires treatment of its cause.[2][3][1] In immune-mediated disease, medical therapy treats inflammation, while ureterolysis relieves mechanical obstruction without preventing relapse or systemic manifestations.[2]

In Santiago's retrospective series of 52 patients with idiopathic RPF and hydronephrosis initially managed without ureterolysis, 36 (69%) had resolution of obstruction with medical management and temporary renal drainage as needed; median stent duration was 16 months, with median clinical and radiographic follow-up of 4.2 and 3.3 years, respectively.[7] Only 15% ultimately required ureterolysis (at median 2.2 years); medication side effects were uncommon (12%).[7] Recurrent obstruction after a stent-free period occurred in 18%.[7]

Timing Considerations​

  • Assess response to medical therapy with repeated renal function and imaging. Failed drainage, renal deterioration or intolerable treatment may prompt surgery before 3–6 months.[2][3]
  • In the Santiago series, patients who ultimately required ureterolysis underwent the procedure at median 2.2 years after diagnosis, suggesting prolonged conservative management is often attempted before surgical escalation.[7]
  • Some authors argue ureterolysis should be considered earlier, particularly with stent failure or declining renal function, rather than as a "last resort". O'Brien and Fernando reported median GFR changes of +25% in the stent-failure group and −10% in 5 nephrostomy-dependent patients. The latter change was not statistically significant.[8]

Outcomes From Separate Cohorts​

StrategySuccessStent durationRenal functionComplications
Medical therapy + temporary drainage as needed (idiopathic RPF)36/52 (69%) obstruction resolution without ureterolysisMedian stent duration 16 monthsWorsening renal function was rare6/52 (12%) potential medication side effects; 9/52 (18%) recurrent obstruction after a stent-free period[7]
Ureterolysis (open)47/50 (94%) stent-free at 12 moNot reportedMedian GFR change at 1 yr: +6% overall; +25% in stent-failure group (n = 20)12% serious (Clavien III–IV)[8]

Practical Decision Framework​

  1. At diagnosis. Assess renal function, infection and obstruction severity. Secure drainage promptly when indicated, establish the diagnosis and etiology, then coordinate disease-directed medical therapy.[2][15]
  2. During treatment. Reassess renal function and imaging early enough to detect failed drainage; do not wait months when function is threatened. If hydronephrosis is resolving and inflammatory markers are normalizing, continue medical therapy and plan stent-removal trial.[3]
  3. Consider ureterolysis if: persistent hydronephrosis despite stenting, declining renal function, intolerable stent symptoms, medication intolerance or failure, or need for tissue diagnosis.[8][1]
  4. Do not delay excessively. Prolonged nephrostomy dependence or chronic obstruction may lead to irreversible renal atrophy, reducing the benefit of eventual ureterolysis.[8]
  5. Post-ureterolysis. Plan stent removal and then reassess renal function and drainage with imaging; the open series removed stents at 3–6 weeks and used blood tests, CT, or diuretic renography, while the laparoscopic series removed stents after at least two weeks and assessed patients with CT or pyelography at three months.[8][13] Continue multidisciplinary assessment of disease activity. Further immunosuppression depends on the cause and activity of RPF and treatment tolerance; surgery does not mandate indefinite medication in every patient.[2][16]

The treatment goal remains freedom from stent or nephrostomy, withdrawal of glucocorticoids, and preservation of renal function, a composite endpoint that neither strategy alone reliably achieves in all patients.[3]

Vascular Surgery — Inflammatory Aortic Aneurysm​

When RPF accompanies an inflammatory abdominal aortic aneurysm (IAAA), involve vascular surgery. For repair-threshold measurement, exclude peri-aortic inflammation and wall edema from aneurysm diameter (ESVS 2024 recommendation 145, class III, level C).[20] ESVS 2024 recommendation 147 advises considering repair at diameter ≥55 mm, favoring EVAR when anatomy is suitable (class IIa, level C). Symptoms, rupture risk and the individual vascular anatomy can change management; a universal 4.5–5-cm threshold is inappropriate.[20]

A 2015 Cochrane review found no eligible randomized or controlled clinical trials comparing elective open repair and EVAR for IAAA. The review provides no trial comparison of hydronephrosis resolution.[19] Fibrosis and ureteral obstruction may persist or progress after vascular repair, so renal drainage may still be needed and lifelong surveillance of the vascular repair, peri-aortic fibrosis, and hydronephrosis is warranted.[20] Treatment timing and any ongoing immunosuppression require multidisciplinary decisions.[17][18][20]

Surgical Biopsy​

Surgery also serves a diagnostic function. Before attributing obstruction to RPF, assess for an intrinsic ureteral lesion, including urothelial cancer, with retrograde pyelography and urine cytology.[3] Choose image-guided core biopsy or surgical biopsy according to accessibility, suspicion for malignancy, tissue requirements and any prior nondiagnostic sample.[6] Robotic-assisted biopsy can be combined with ureterolysis in a single procedure.[9]

See Also​

Videos​

Laparoscopic Left Ureterolysis with Omental Wrap for Retroperitoneal Fibrosis
AINU Surgical Videos (2025)

References​

1. Fenaroli P, Maritati F, Vaglio A. "Into Clinical Practice: Diagnosis and Therapy of Retroperitoneal Fibrosis." Current Rheumatology Reports. 2021;23(3):18. doi:10.1007/s11926-020-00966-9

2. Vaglio A, Salvarani C, Buzio C. "Retroperitoneal Fibrosis." Lancet. 2006;367(9506):241–251. doi:10.1016/S0140-6736(06)68035-5

3. Tanaka T, Masumori N. "Current Approach to Diagnosis and Management of Retroperitoneal Fibrosis." International Journal of Urology. 2020;27(5):387–394. doi:10.1111/iju.14218

4. Mertens S, Zeegers AG, Wertheimer PA, Hendriksz TR, van Bommel EF. "Efficacy and Complications of Urinary Drainage Procedures in Idiopathic Retroperitoneal Fibrosis Complicated by Extrinsic Ureteral Obstruction." International Journal of Urology. 2014;21(3):283–288. doi:10.1111/iju.12234

5. Scheidt MJ, Hohenwalter EJ, Pinchot JW, et al. "ACR Appropriateness Criteria Radiologic Management of Urinary Tract Obstruction." Journal of the American College of Radiology. 2020;17(5S):S281–S292. doi:10.1016/j.jacr.2020.01.039

6. Loricera J, Secada-Gómez C, Martín-Gutiérrez A, Blanco R, González-Vela C. "Clinical Features, Diagnosis, and Management of Retroperitoneal Fibrosis in a University Referral Hospital and Literature Review." Internal and Emergency Medicine. 2026. doi:10.1007/s11739-026-04298-x

7. Santiago J, Swartz R, Marder W, et al. "Including Medical Management in the Urologic Approach to Idiopathic Retroperitoneal Fibrosis." Urology. 2021;152:167–172. doi:10.1016/j.urology.2021.03.002

8. O'Brien T, Fernando A. "Contemporary Role of Ureterolysis in Retroperitoneal Fibrosis: Treatment of Last Resort or First Intent? An Analysis of 50 Cases." BJU International. 2017;120(4):556–561. doi:10.1111/bju.13915

9. Keehn AY, Mufarrij PW, Stifelman MD. "Robotic Ureterolysis for Relief of Ureteral Obstruction From Retroperitoneal Fibrosis." Urology. 2011;77(6):1370–1374. doi:10.1016/j.urology.2010.11.025

10. Ross J, Morcos M, Rowe NE. "Safety Analysis of Ureterolysis for Ureteric Obstruction Secondary to Retroperitoneal Fibrosis." World Journal of Urology. 2025;43(1):189. doi:10.1007/s00345-025-05576-7

11. Styn NR, Frauman S, Faerber GJ, Wolf JS. "University of Michigan Surgical Experience With Ureterolysis for Retroperitoneal Fibrosis: A Comparison of Laparoscopic and Open Surgical Approaches." Urology. 2011;77(2):339–343. doi:10.1016/j.urology.2010.03.036

12. Srinivasan AK, Richstone L, Permpongkosol S, Kavoussi LR. "Comparison of Laparoscopic With Open Approach for Ureterolysis in Patients With Retroperitoneal Fibrosis." The Journal of Urology. 2008;179(5):1875–1878. doi:10.1016/j.juro.2008.01.030

13. Ilki FY, Bulbul E, Gultekin MH, et al. "Comparison of Laparoscopic and Open Ureterolysis for Retroperitoneal Fibrosis: Results From a Tertiary Referral Center." Journal of Endourology. 2022;36(11):1425–1430. doi:10.1089/end.2022.0135

14. Mufarrij PW, Lipkin ME, Stifelman MD. "Robot-Assisted Ureterolysis, Retroperitoneal Biopsy, and Omental Wrap: Pilot Series for the Treatment of Idiopathic Retroperitoneal Fibrosis." Journal of Endourology. 2008;22(8):1669–1675. doi:10.1089/end.2008.0034

15. Zhang W, Stone JH. "Management of IgG4-related Disease." The Lancet Rheumatology. 2019;1(1):e55–e65. doi:10.1016/S2665-9913(19)30017-7

16. Raglianti V, Rossi GM, Vaglio A. "Idiopathic Retroperitoneal Fibrosis: An Update for Nephrologists." Nephrology, Dialysis, Transplantation. 2021;36(10):1773–1781. doi:10.1093/ndt/gfaa083

17. Kadian-Dodov D, Seo P, Robson PM, Fayad ZA, Olin JW. "Inflammatory Diseases of the Aorta: JACC Focus Seminar, Part 2." Journal of the American College of Cardiology. 2022;80(8):832–844. doi:10.1016/j.jacc.2022.05.046

18. Chaikof EL, Dalman RL, Eskandari MK, et al. "The Society for Vascular Surgery Practice Guidelines on the Care of Patients With an Abdominal Aortic Aneurysm." Journal of Vascular Surgery. 2018;67(1):2–77.e2. doi:10.1016/j.jvs.2017.10.044

19. Capoccia L, Riambau V. "Endovascular Repair Versus Open Repair for Inflammatory Abdominal Aortic Aneurysms." Cochrane Database of Systematic Reviews. 2015;(4):CD010313. doi:10.1002/14651858.CD010313.pub2

20. Wanhainen A, et al. European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms. Recommendation 147. Eur J Vasc Endovasc Surg. 2024. Guideline.

21. Hsu THS, Tarin T. Laparoscopic ureteral surgery. In: Montague DK, Gill IS, Angermeier KW, Ross JH, eds. Textbook of Reconstructive Urologic Surgery. Informa Healthcare; 2008:200-208.

22. Peterson AC. Ureteral Stricture Repair and Ureterolysis. In: Smith JA Jr, Dmochowski RR, Thomas JC, Preminger GM, eds. Hinman's Atlas of Urologic Surgery. 5th ed. Elsevier; 2025:295-302.

23. Neulander EZ, Rivera I, Kaneti J, Wajsman Z. "Ureterolysis with ureterotomy and omental sleeve wrap in patients with radiation induced pelvic retroperitoneal fibrosis." Cent European J Urol. 2019;72(3):307–311. doi:10.5173/ceju.2019.1965

24. Vaglio A, Peyronel F, Bajema IM, Pegoraro F. "Retroperitoneal fibrosis." Lancet. 2026;408(10555):649–664. doi:10.1016/S0140-6736(26)00037-1

25. Carletti F, Turcan A, Tamborino F, et al. "Single-port robot-assisted ureterolysis for retroperitoneal fibrosis: A less invasive path to functional recovery." BJUI Compass. 2026;7(5):e70218. doi:10.1002/bco2.70218