Abstract
Background
Ureteral endometriosis with hydroureteronephrosis can impair renal function, yet few clear guidelines exist for its surgical treatment. This study aimed to compare the clinicopathological features between patients undergoing ureterolysis with nodule excision versus segmental ureterectomy with anastomosis for ureteral endometriosis with hydroureteronephrosis, and to report the postoperative outcomes.
Methods
This retrospective study included 74 patients with ureteral endometriosis and hydroureteronephrosis who underwent surgery at a tertiary hospital between 2004 and 2024. Clinicopathological characteristics were compared between the ureterolysis and segmental ureterectomy groups using Student’s t-test or Mann-Whitney U test for continuous variables, and the χ² test or Fisher’s exact test for categorical variables. Variables with P < 0.05 on between-group comparisons were entered into a multivariable logistic regression analysis. Surgical outcomes, including recurrence of hydroureteronephrosis and ureteral complications, were reported.
Results
Among the 74 patients, 25.7% presented with urinary symptoms. All patients had additional pelvic endometriosis beyond ureteral involvement, including ovarian endometriomas (75.7%) and deep endometriosis at other sites (82.4%). Ureteral endometriosis was classified as extrinsic (82.4%) or intrinsic (17.6%). 54 (73%) patients underwent ureterolysis with nodule excision and 20 (27%) underwent segmental ureterectomy with anastomosis. All 13 intrinsic lesions underwent segmental ureterectomy (P < 0.001). Multivariable analysis revealed that previous endometriosis surgery (OR = 4.413; 95%CI: 1.138–17.108; P = 0.032) and preoperative failed Double-J stenting (OR = 7.833; 95%CI: 1.946–31.522; P = 0.004) were independently associated with the segmental ureterectomy. At a median follow-up of 9 years, the ureterolysis group had 7.4% recurrent hydroureteronephrosis and 1.9% ureteral fistula; the segmental ureterectomy group experienced no recurrent hydroureteronephrosis or ureteral complications.
Conclusions
Ureteral endometriosis complicated by hydroureteronephrosis often lacks urinary symptoms, with only a minority of lesions classified as intrinsic subtypes, and is almost always accompanied by ovarian endometriomas or deep endometriosis at other pelvic sites. After careful patient selection, 73% of subjects underwent ureterolysis with nodule excision and demonstrated acceptable long-term outcomes. Segmental ureterectomy with anastomosis was reserved for refractory cases, such as patients with intrinsic ureteral lesions, a history of prior endometriosis surgery, or failed preoperative Double-J stenting.
Supplementary Information
The online version contains supplementary material available at https://doi.org/10.1186/s12905-026-04664-z.
Keywords: Ureteral endometriosis, Hydroureteronephrosis, Ureterolysis, Segmental ureterectomy
Introduction
Ureteral endometriosis (UE) is the condition in which endometriosis or its associated fibrosis causes compression or distortion of the normal ureteral anatomy, even if hydronephrosis is not present [1–4]. Although historically viewed as rare, ureteral endometriosis is now increasingly recognized, with an incidence ranging from 10% to 48% in the deep endometriosis (DE) population [5–9]. Ureteral endometriosis can be divided into 2 forms, extrinsic (80%) and intrinsic (20%). The extrinsic form is defined by infiltration of endometriotic tissue into the ureteral adventitia, whereas the intrinsic form involves infiltration of the ureteral muscularis [5, 6].
Ureteral endometriosis frequently presents with non-specific symptoms, and approximately half of affected individuals remain asymptomatic. Among symptomatic cases, flank pain is observed in approximately 25%, hematuria in 15% [10]. Additional manifestations such as dysmenorrhea and deep dyspareunia may also occur. UE is commonly associated with other sites of DE, and as a result, clinical features are often attributable to these concomitant lesions rather than to ureteral involvement alone [8]. Therefore, the recognition of ureteral endometriosis remains challenging [11]. Delayed diagnosis can lead to hydroureteronephrosis, resulting in impaired renal function or even complete loss of kidney function. The reported prevalence of hydronephrosis or hydroureter in patients with ureteral endometriosis ranges from 10.8% to 54.4% [10, 12–15].
Given the limitations of medical treatment in reversing the fibrotic tissue of UE, surgical intervention becomes necessary, especially in cases with ureteral obstruction to free ureteral obstruction and prevent further deterioration of renal function. Surgical options include conservative ureterolysis or more radical procedures such as ureterectomy with end-to-end anastomosis or ureteroneocystostomy, chosen based on the type, location, extent of ureteral involvement, and renal function [16]. The laparoscopic approach has been established as feasible, effective, and safe for both conservative and radical procedures [5, 17, 18]. The optimal surgical strategy for obstructive ureteral endometriosis remains controversial. A review by Cavaco-Gomes et al. suggests that ureterolysis can be employed as the initial treatment for most patients, including those presenting with hydroureteronephrosis [10]. However, a meta-analysis by Saeed Alborzi et al. recommends that for lesions associated with hydronephrosis, a radical and complete procedure should be performed primarily [15]. Thus, there is currently no consensus on the optimal surgical management of ureteral endometriosis complicated by hydroureteronephrosis.
This study aimed to compare the clinicopathological features between patients undergoing ureterolysis versus segmental ureterectomy for ureteral endometriosis with hydroureteronephrosis, and to report the postoperative outcomes of both procedures, including recurrent hydroureteronephrosis and ureteral complications.
Materials and methods
Setting and participants
The diagnosis of UE was confirmed according to the following histologic definition: either compression of the ureter by an endometriotic nodule, with or without ureteral dilatation [1], or infiltration of the ureteral muscularis by endometriotic tissue [6]. Based on the above criteria, we enrolled 74 patients with ureteral endometriosis and preoperative hydroureteronephrosis who underwent surgery for pelvic endometriosis in the Department of Obstetrics and Gynecology of a tertiary hospital between November 2004 and December 2024. The 74 patients had preoperative hydroureteronephrosis confirmed by consecutive renal ultrasounds, after excluding other obstructive causes (e.g., tumor, urolithiasis), and were successfully followed up. (Fig. 1)
Fig. 1.
Flowchart. All the patients with UE complicated by hydroureteronephrosis. UE = ureteral endometriosis
All patients underwent surgical excision of pelvic endometriosis, which included cystectomy or adnexectomy for endometriomas with or without hysterectomy, as well as resection of deep pelvic endometriosis lesions. Conservative surgery refers to ovarian cystectomy or unilateral adnexectomy, and radical surgery denotes total hysterectomy with bilateral salpingo-oophorectomy.
Within a multidisciplinary team framework, a standardized surgical approach was adopted. All patients initially underwent ureterolysis with nodule excision. If preoperative evaluation confirmed intrinsic ureteral endometriotic involvement, or if ureteral patency could not be restored after ureterolysis, the operation was converted intraoperatively to segmental ureterectomy with anastomosis. In total, 54 patients underwent ureterolysis with nodule excision alone, whereas 20 patients required conversion to segmental ureterectomy with anastomosis. Among these 20 patients receiving converted segmental ureterectomy, 1 case had pathologically confirmed intrinsic ureteral endometriosis via preoperative ureteroscopic biopsy, and the remaining 19 cases failed to achieve restored ureteral patency after intraoperative ureterolysis. Based on the location of the disease and remaining ureteral length, 19 of the latter group underwent ureteroneocystostomy and one underwent ureteroureteral anastomosis.
This study was approved by the local Institutional Review Board.
Data collection and follow-up
Detailed demographic information and comprehensive medical histories of the enrolled patients were collected, with the following parameters recorded: pre-operative characteristics (age at surgery, fertility before surgery, previous surgery for endometriosis, clinical symptoms, auxiliary examinations, etc.), pre-operative management (Double-J stent placement, Gonadotropin-Releasing Hormone Agonist (GnRHa) pretreatment), intraoperative information (gynecologic and ureteral surgical procedures, presence and location of other endometriotic lesions, histologic findings etc.), and surgical outcomes. The evaluated surgical outcomes included ureteral complications, resolution and recurrence of hydroureteronephrosis, recurrence of ovarian endometrioma or deep endometriosis, relief of endometriosis-related symptoms (complete resolution, partial improvement or no improvement), and therapeutic regimens for patients requiring reintervention.
In detail, some patients underwent an additional nephrogram examination to assess kidney function. The standards of unilateral kidney function according to the department of nuclear medicine are as follows: normal, glomerular filtration rate (GFR) ≥ 40 ml/min/1.73 m2; mildly decreased, GFR 30–40 ml/min/1.73 m2; moderately decreased, GFR 20–30 ml/min/1.73 m2; severely decreased, GFR 10–20 ml/min/1.73 m2; and dysfunctional GFR < 10 ml/min/1.73 m2. The criteria for distinguishing intrinsic versus extrinsic ureteral endometriosis were defined as follows. Extrinsic ureteral endometriosis refers to endometriotic infiltration limited to the ureteral adventitia, while intrinsic ureteral endometriosis presents with infiltration extending into the ureteral muscularis. Patients without available ureteral wall pathological specimens could not be accurately categorized as intrinsic or extrinsic subtypes and were therefore assigned to the unclassified cohort. Regarding GnRHa pretreatment, the injection schedule was as follows. The first subcutaneous injection of 3.75 mg GnRHa was administered on any day between day 1 and day 5 of menstruation, followed by repeated injections every four weeks. Endometriosis surgery was performed after a total of 3 to 6 injections. Additionally, other hormonal agents, such as dienogest, oral contraceptives, progestins, or GnRH antagonists, were not used preoperatively in any patient.
All patients underwent urinary and gynecologic ultrasound at 3 months postoperatively, followed by semiannual ultrasound surveillance for 2 years, and annual ultrasound examinations thereafter. The Double-J stent was removed under cystoscopic guidance 3 months after surgery, with urinary ultrasound performed both before and after stent removal. Based on renal ultrasound, at three months postoperatively or after removal of the double-J stent, disappearance of hydroureteronephrosis was defined as “resolution of hydroureteronephrosis”. The reappearance of hydroureteronephrosis after its initial resolution was defined as “Recurrent hydroureteronephrosis”. Recurrence of ovarian endometrioma or deep endometriosis was defined as the new appearance of these lesions on pelvic ultrasound or gynecologic examination after a lesion-free 3-month postoperative pelvic ultrasound.
Clinical and telephone follow-ups were conducted to further supplement and update this information.
Statistical analysis
Statistical analysis was conducted using SPSS Version 26.0 (IBM, USA). Descriptive statistics were presented as mean ± standard deviation or median (interquartile range) for continuous variables, and as frequency (percentage) for categorical variables. Differences in characteristics between the ureterolysis and segmental ureterectomy groups were assessed using Student’s t-test or Mann-Whitney U test for continuous variables, and the χ² test or Fisher’s exact test for categorical variables, as appropriate. Variables with P < 0.05 on between-group comparisons were entered into a multivariable logistic regression analysis, and odds ratio (OR) with 95% confidence interval (CI) were calculated. A two-sided P value < 0.05 was considered statistically significant. Kaplan-Meier analysis was performed for the entire cohort to estimate the cumulative incidence of recurrent hydroureteronephrosis over time. Follow-up time spanned 1 to 21 years. The Kaplan-Meier curve was plotted to display long-term recurrence trends.
Results
Demographic and clinical characteristics
Between November 2004 and December 2024, 74 patients with surgically confirmed ureteral endometriosis and preoperative hydroureteronephrosis were followed up for a median of 9 years (range: 1–21 years).
Among the 74 patients, preoperative dysmenorrhea was present in 77.0% (mean NRS 6.6 ± 2.2). Additional symptoms included dyspareunia, rectal tenesmus, or dyschezia (37.8%); thigh, flank, or lower back pain (39.2%); and urinary symptoms (frequency, urgency, dysuria, difficulty voiding, or hematuria) in 25.7% of patients. A previous surgery for endometriosis had been performed in 25.7%, and palpable nodules were found in 47.3% on examination. Ureteral width on ultrasonography was 1.0 (0.7–1.2)cm, and pelvis width on ultrasonography was 1.6 (1.2–2.3)cm. Preoperative renal scintigraphy (n = 45) revealed impaired split renal function in 31 patients (68.9%), graded as mild (32.3%), moderate (29.0%), severe (22.6%), or non-functional (16.1%). Hydroureteronephrosis was left-sided in 37.8%, right-sided in 43.2%, and bilateral in 18.9%. Sites of ureteral involvement were the distal segment in 86.5% of patients and the mid segment in 13.5%. 13 (17.6%, 13/74) patients presented intrinsic lesions. 64.9% had coexisting adenomyosis. 75.7% had concomitant endometriomas. Among these patients with endometriomas, 85.7% exhibited ipsilateral involvement relative to the UE. Deep endometriosis at other sites was present in 82.4% of patients, with lesions involving the uterosacral ligaments (67.6%; 94.0% ipsilateral to ureteral disease), pouch of Douglas or rectovaginal septum (77.0%), intestine (n = 14), and bladder (n = 2). Ureteral double-J stent was placed preoperatively or intraoperatively in 85.1% patients. According to the American Society for Reproductive Medicine (ASRM) staging criteria, all cases were classified as stage IV, with a median ASRM score of 68 (IQR: 51.5–86.5). (Table 1)
Table 1.
Clinical characteristics of ureteral endometriosis (n=74)
| Patient characteristic | Total population n = 74 (%) |
|---|---|
| Age, years (IQR) | 41 (35-46) |
| Nulligravida | 17/74 (23.0) |
| Nulliparous | 28/74 (37.8) |
| Dysmenorrhea | 57/74 (77.0) |
| NRS score (Mean±SD) | 6.6±2.2 |
| Dyspareunia/Dyschezia/Rectal tenesmus/Chronic pelvic pain | 28/74 (37.8) |
| Other sites of pain | 29/74 (39.2) |
| Low back | 27/29 (93.1) |
| Flank | 3/29 (10.3) |
| Thigh | 1/29 (3.4) |
| Urinary symptoms | 19/74 (25.7) |
| Frequency or Urgency | 9/19 (47.4) |
| Dysuria | 4/19 (21.1) |
| Difficulty Voiding | 3/19 (15.8) |
| Hematuria | 4/19 (21.1) |
| Previous surgery for endometriosis | 19/74 (25.7) |
| Physical examination | |
| Palpable nodule | 35/74 (47.3) |
| Preoperative testing | |
| Cr umol/L(IQR) | 67.5 (59.0-77.3) |
| CA125 U/ml(IQR) | 48.1 (33.1-78.1) |
| Ultrasonography | |
| Ureteral width cm(IQR) | 1.0 (0.7-1.2) |
| Pelvis width cm(IQR) | 1.6 (1.2-2.3) |
| Differential Renal Function Impairment | 31/45 (68.9) |
| mildly decreased | 10/31 (32.3) |
| moderately decreased | 9/31 (29.0) |
| severely decreased | 7/31 (22.6) |
| dysfunctional | 5/31 (16.1) |
| Perioperative characteristics | |
| Preoperative or Intraoperative Double-J Stent Placement | 63/74 (85.1) |
| Preoperative GnRHa Pretreatment | 41/74 (55.4) |
| Laterality of UE | |
| Left | 28/74 (37.8) |
| Right | 32/74 (43.2) |
| Bilateral | 14/74 (18.9) |
| Site of ureteral involvement | |
| Middle ureter | 10/74 (13.5) |
| distal ureter | 64/74 (86.5) |
| Type of UE* | |
| Intrinsic | 13/74 (17.6) |
| Unclassified | 61/74 (82.4) |
| Ovarian endometriosis | 56/74 (75.7) |
| Ipsilateral Endometrioma with UE | 48/56 (85.7) |
| Other pelvic deep endometriosis | 61/74 (82.4) |
| Uterosacral ligaments endometriosis | 50/74 (67.6) |
| Ipsilateral USL Endometriosis with UE | 47/50 (94.0) |
| Douglas Pouch/Rectovaginal Septum Endometriosis | 57/74 (77.0) |
| intestinal | 14/74 (18.9) |
| bladder | 2/74 (2.7) |
| abdominal wall | 2/74 (2.7) |
| vaginal | 1/74 (1.4) |
| Adenomyosis | 48/74 (64.9) |
| Ureteral surgery | |
| Ureterolysis with nodule excision | 54/74 (73.0) |
| Segmental ureterectomy with ureteroneocystostomy | 19/74 (25.7) |
| Segmental ureterectomy with ureteroureteral anastomosis | 1/74 (1.6) |
| Gynecological surgery | |
| Conservative surgery | 41/74 (55.4) |
| Radical Surgery | 33/74 (44.6) |
| ASRM Stagea | |
| IV stage | 74/74 (100.0) |
| ASRM score (IQR) | 68 (51.5-86.5) |
| Blood loss, ml (IQR) | 175 (82.5-300.0) |
| Operative time, min(IQR) | 120 (90-180) |
| Postoperative treatment | |
| None | 39/74 (52.7) |
| GnRHa | 13/74 (17.6) |
| LNG-IUS | 5/74 (6.8) |
| Dienogest | 3/74 (4.1) |
| Dienogest following GnRHa | 10/74 (13.5) |
| Otherb | 4/74 (5.4) |
| Resolution ofhydroureteronephrosis | 74/74 (100.0) |
| Postoperative ureteral complicationsc | 1/74 (1.4) |
| Recurrent hydroureteronephrosis | 4/74 (5.4) |
a ASRM stage: the American Society for Reproductive Medicine staging system
b Including 1 patient wth Anastrozole, 1 patient with Gestrinone, 2 patients with Medroxyprogesterone Acetate
c 1 patient with ureteral fistula
*Thirteen lesions were definitively confirmed as the intrinsic subtype on histopathology: one diagnosed by preoperative ureteroscopic biopsy and 12 confirmed via surgical specimens after segmental ureterectomy. The other 61 lesions could not be accurately categorized as intrinsic or extrinsic and were therefore grouped into the unclassified cohort
All patients underwent surgical excision of pelvic endometriosis, which included cystectomy or adnexectomy for endometriomas with or without hysterectomy, as well as resection of deep pelvic endometriosis lesions. Conservative surgery accounted for 55.4% of cases, while radical surgery comprised 44.6%. Among the conservative surgeries, 23 cases involved ovarian cystectomy for endometriomas, and 11 cases involved adnexectomy. (Table 1)
Surgical management of ureteral endometriosis included ureterolysis with nodule excision (73.0%, 54 patients), segmental ureterectomy with ureteroneocystostomy (25.7%, 19 patients), and segmental ureterectomy with ureteroureteral anastomosis (1.6%, 1 patient). (Table 1).
Comparison of characteristics between ureterolysis and segmental ureterectomy
Based on the type of ureteral surgery performed, the 74 patients were divided into two groups: the ureterolysis with nodule excision group (n = 54) and the segmental ureterectomy with anastomosis group (n = 20). The anastomosis procedures comprised ureteroneocystostomy (n = 19) and ureteroureteral anastomosis (n = 1).
Compared with the ureterolysis with nodule excision group, patients in the segmental ureterectomy with anastomosis group had a higher prevalence of low back/flank/thigh pain(P = 0.026), a previous surgery for endometriosis(P = 0.021), and failed preoperative Double-J stent placement(P = 0.002); all 13 cases with intrinsic ureteral endometriosis underwent segmental ureterectomy with anastomosis(P < 0.001). No significant differences were observed between the two groups in ureteral width, pelvis width on ultrasonography, or differential renal function impairment (P = 0.257, P = 0.162, and P = 1.000, respectively). Compared with the segmental ureterectomy group, patients in the ureterolysis group had significantly shorter operative times and postoperative hospital stays (both P < 0.001) (Table 2).
Table 2.
Comparison of characteristics between ureterolysis with nodule excision and segmental ureterectomy with anastomosis cohorts (n = 74)
| Patient characteristic | Ureterolysis with nodule excision (n = 54), n(%) |
Segmental ureterectomy with anastomosis (n = 20), n(%) |
X2/Z | P-Value |
|---|---|---|---|---|
| Age, years (IQR) | 42 (38.3–46.0) | 39 (33.0-42.5) | -1.92 | 0.055 |
| Dysmenorrhea | 41/54 (75.9) | 16/20 (80.0) | 0.14 | 0.711 |
| Dyspareunia/Dyschezia/Rectal tenesmus/Chronic pelvic pain | 19/54 (35.2) | 9/20 (45.0) | 0.60 | 0.439 |
| Low back/flank/thigh pain | 17/54 (31.5) | 12/20 (60.0) | 4.98 | 0.026 |
| Urinary symptoms | 12/54 (22.2) | 7/20 (35.0) | 1.25 | 0.264 |
| Previous surgery for endometriosis | 10/54 (18.5) | 9/20 (45.0) | 5.36 | 0.021 |
| Preoperative Cr umol/L(IQR) | 66 (58.3–76.8) | 73.9 (62.5–81.0) | -1.54 | 0.123 |
| Preoperative CA125 U/ml(IQR) | 48.1 (33.9–75.8) | 40.8 (33.15–79.3) | -0.15 | 0.880 |
| Ultrasonography | ||||
| Ureteral width cm(IQR) | 0.9 (0.62–1.10) | 1.05 (0.78–1.22) | -1.151 | 0.257 |
| Pelvis width cm(IQR) | 1.55 (1.17-2.00) | 2 (1.35–2.45) | -1.408 | 0.162 |
| Preoperative differential renal function impairment | 1.19 | 1.000 | ||
| Mildly decreased | 7/21(33.3) | 3/10(30.0) | ||
| Moderately decreased | 5/21(23.8) | 4/10(40.0) | ||
| Severely decreased | 4/21(19.0) | 3/10(30.0) | ||
| Dysfunctional | 5/21(23.8) | 0/10(0.0) | ||
| Site of ureteral obstruction | 0.29 | 0.719 | ||
| Middle ureter | 8/54 (14.8) | 2/20 (10.0) | ||
| distal ureter | 46/54 (85.2) | 18/20 (90.0) | ||
| Type of UE | 42.60 | < 0.001 | ||
| Unclassified | 54/54 (100.0) | 7/20 (35.0) | ||
| Intrinsic | 0/54 (0.0) | 13/20 (65.0) | ||
| Ovarian endometriosis | 44/54 (81.5) | 12/20 (60.0) | 0.66 | 0.056 |
| Other pelvic deep endometriosis | 43/54 (79.6) | 18/20 (90.0) | 1.08 | 0.298 |
| Adenomyosis | 36/54 (66.7) | 12/20 (60.0) | 0.29 | 0.594 |
| ASRM score | 68 (53.0–87.0) | 62 (48.0–78.0) | -0.17 | 0.869 |
| Preoperative Double-J Stent Placement | ||||
| Successful | 37/43 (86.0) | 10/20 (50.0) | 9.36 | 0.002 |
| Failed | 6/43 (14.0) | 10/20 (50.0) | ||
| Preoperative GnRHa Pretreatment | 33/54 (61.1) | 8/20 (40.0) | 2.63 | 0.105 |
| Operative time, min(IQR) | 120 (80–148) | 175 (124–251) | -3.74 | < 0.001 |
| Blood loss, ml(IQR) | 125 (50–300) | 200 (100–300) | -1.13 | 0.257 |
| Postoperative hospital stay, days(IQR) | 6 (4–8) | 14 (8–15) | -4.26 | < 0.001 |
Bold values denote P < 0.05
Between-group comparisons using Chi-square or Fisher’s exact tests identified four factors significantly associated with the choice of surgical approach: low back/flank/thigh pain, previous endometriosis surgery, failed preoperative Double-J stenting, and intrinsic lesions (all P < 0.05; Table 2). Among these, intrinsic lesions were exclusively observed in the segmental ureterectomy group (13/20 vs. 0/54, P < 0.001, Fisher’s exact test) and were therefore excluded from multivariable analysis due to zero events in the ureterolysis group. The remaining three variables were entered into a multivariable logistic regression model (Table 3). Multivariable analysis revealed that previous endometriosis surgery (OR = 4.413; 95%CI: 1.138–17.108; P = 0.032) and failed Double-J stenting (OR = 7.833; 95%CI: 1.946–31.522; P = 0.004) were independently associated with the segmental ureterectomy, while low back/flank/thigh pain was not significantly associated with the procedure after adjustment (OR = 3.397, 95%CI:0.971–11.879, P = 0.056). (Table 3).
Table 3.
Multivariable Logistic regression analysis of factors for segmental ureterectomy with anastomosis
| Patient characteristic | Odds Ratio | 95%CI | P-Value |
|---|---|---|---|
| Low back/flank/thigh pain | 3.397 | 0.971–11.879 | 0.056 |
| Previous surgery for endometriosis | 4.413 | 1.138–17.108 | 0.032 |
| Failed Preoperative Double-J Stent Placement | 7.833 | 1.946–31.522 | 0.004 |
Bold values denote P < 0.05
Surgical outcomes for ureteral endometriosis with hydroureteronephrosis
All 74 patients achieved postoperative resolution of hydroureteronephrosis. One patient (1/54, 1.9%) in ureterolysis with nodule excision group developed a ureteral fistula, which was treated with right percutaneous nephrostomy on postoperative day 14. The nephrostomy tube was removed four months later, with no subsequent evidence of hydroureteronephrosis on follow-up ultrasounds. In ureterolysis with nodule excision group, the recurrence rate was 7.4% (4/54), with a median time to recurrence of 15 months (range: 12–24 months) (Table 4). Of the four patients with recurrent hydroureteronephrosis, subsequent management included: radical gynecologic surgery with ureterolysis (n = 1, followed by dienogest); stent plus GnRHa (n = 1); stent plus LNG-IUS (n = 1); stent plus dienogest (n = 1) (Table 5). In the segmental ureterectomy with anastomosis group, no postoperative ureteral complications or recurrence of hydroureteronephrosis (Table 4). Kaplan–Meier curves for recurrent hydroureteronephrosis are presented in the Supplementary Fig. 1.
Table 4.
Surgical outcomes of ureterolysis with nodule excision and segmental ureterectomy with anastomosis (n = 74)
| Parameters | Ureterolysis with nodule excision (n = 54) |
Segmental ureterectomy with anastomosis (n = 20) |
|---|---|---|
| Resolution of hydroureteronephrosis | 54/54 (100.0) | 20/20 (100.0) |
| Recurrent hydroureteronephrosis | 4/54 (7.4) | 0/20 (0.0) |
| Ureteral complications | 1/54 (1.9) | 0/20 (0.0) |
Table 5.
Recurrent hydroureteronephrosis after ureterolysis with nodule excision or segmental ureterectomy with anastomosis
| Patient | Age, years | NRS score | Urinary symptoms | Renal Function Impairment | Previous surgery for endometriosis | Intrinsic/unclassified disease | Site of ureteral involvement | Concomitant endometriosis | Preoperative Double-J Stent Placement | Gynecological surgery | Postoperative medical management | Time to recurrence, months | Subsequent management of recurrent hydroureteronephrosis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Patient1 | 42 | 4 | No | Not tested | No | unclassified | Distal ureter | Endometrioma | No | Conservative surgery | GnRHa | 24 | Radical gynecologic surgery with ureterolysis, followed by dienogest |
| Patient2 | 29 | 7 | No | Moderately decreased | No | unclassified | Distal ureter | Endometrioma | Successful | Conservative surgery | GnRHa | 18 | Double-J stent plus GnRHa |
| Patient3 | 32 | 6 | Frequency | Not tested | No | unclassified | Middle ureter | Endometrioma | No | Conservative surgery | LNG-IUS | 12 | Double-J stent plus LNG-IUS |
| Patient4 | 35 | 5 | Difficulty Voiding | Dysfunctional | Cystectomy | unclassified | Distal ureter | Endometrioma | Failed | Conservative surgery | GnRHa+Dienogest | 12 | Double-J stent plus dienogest |
Treatment outcomes of endometriosis-related symptoms were as follows. Among 57 patients with dysmenorrhea, dysmenorrhea completely resolved in 41 (71.9%) and partially improved in the remaining 16 (28.1%). Of the 28 patients with dyspareunia, dyschezia, rectal tenesmus or chronic pelvic pain, symptoms disappeared in 23 (82.1%) and were alleviated in the other 5. All 19 patients with urinary symptoms achieved complete resolution after surgery. For the 29 patients with low back, flank or thigh pain, symptoms fully resolved in 23 (79.3%), partially relieved in 4 (13.8%), and remained unchanged in 2 (6.9%).
Regarding recurrence of ovarian endometrioma or deep endometriosis, postoperative ultrasonography detected recurrent lesions in 2 patients. One patient experienced recurrent ovarian endometrioma 5 years after laparoscopic bilateral cystectomy; a second laparoscopic cystectomy was performed, followed by 5 cycles of GnRHa therapy and long-term dienogest maintenance without subsequent relapse. The other patient developed a right ovarian endometrioma recurrence 1 year after bilateral cystectomy and received a levonorgestrel-releasing intrauterine system with stable disease since placement.
Discussion
This study specifically focused on patients with ureteral endometriosis and hydroureteronephrosis to analyze their clinical characteristics and surgical outcomes over an extended follow-up period (median 9 years). Consistent with previous reports, we found that few patients presented urinary symptoms. Only a minority of ureteral lesions were intrinsic subtypes, and most lesions could not be definitively classified. Additionally, the majority of patients had concomitant ovarian endometriomas or deep endometriosis at other pelvic sites [5, 6, 10, 13, 19, 20]. This asymptomatic nature may contribute to delayed diagnosis and silent renal function impairment, and these findings highlight that ureteral involvement rarely occurs in isolation [19, 20]. Regarding surgical outcomes, the majority of patients (73%) were successfully treated with ureterolysis alone, which provided acceptable long-term outcomes (7.4% recurrence of hydroureteronephrosis and 1.9% ureteral fistula at 9 years). Segmental ureterectomy was reserved for patients with more severe clinicopathological features—specifically intrinsic lesions, previous endometriosis surgery, or failed preoperative stenting—and yielded excellent outcomes with no recurrent hydroureteronephrosis or ureteral complications. Both procedures achieved favorable results within their respective patient populations. These findings support a risk-stratified approach to the surgical management of ureteral endometriosis with hydroureteronephrosis.
The choice of UE treatment should aim to relieve ureteral obstruction, preserve renal function and prevent disease relapse [16, 21]. However, current clinical decision-making is challenging, and there is still no consensus among experts about the gold standard for treatment [22]. Some authors consider preoperative hydroureteronephrosis an indication for ureteral resection, whereas others prefer ureterolysis first and consider segmental ureterectomy only when the ureter cannot be adequately mobilized [2, 14, 19, 23–26]. Our study is consistent with the latter. The proportion of patients with hydroureteronephrosis who underwent ureterolysis alone in our study (73%) is consistent with the 78.4% rate reported by Hu et al. and 62.5% rate by Mereu L et al. [13, 25]. Additionally, our study demonstrated that patients who underwent segmental ureterectomy with anastomosis presented more severe ureteral endometriotic involvement, which highlights the critical importance of distinguishing candidates appropriate for ureterolysis from those requiring segmental ureterectomy with anastomosis. Several studies have investigated this issue in the context of ureteral endometriosis. Lou Donval et al. identified age, prior endometriosis surgery, rectovaginal nodule size ≥ 30 mm on Magnetic Resonance Imaging (MRI), rectal/sigmoid involvement, and ureteral dilation as factors significantly associated with complex ureteral procedures (e.g., ureteral dissection, segmental resection, or nephroureterectomy) [6]. Gennaro KH et al. revealed that urinary symptoms, flank pain, and hydronephrosis were significantly more common in patients requiring more extensive urologic surgical procedures [27]. However, most previous studies included patients with ureteral endometriosis both with and without hydroureteronephrosis, and few have specifically focused on those presenting with hydroureteronephrosis. By exclusively enrolling patients with hydroureteronephrosis, our study provides important insights into the management of ureteral endometriosis complicated by this condition and lays the groundwork for future research.
A few studies have reported that in patients with severe ureteral endometriosis who underwent ureterolysis, the recurrence rate ranges from 9% to 15% [6, 25, 28], and the frequency of urinary fistula ranges from 0% to 7.7% [5], regardless of the presence or absence of hydroureteronephrosis [3, 18]. However, studies exclusively enrolling patients with hydroureteronephrosis are scarce. Notably, one study including 56 patients with hydroureteronephrosis reported a ureteral fistula rate of 2.8% and a recurrent ureteral endometriosis rate of 8.5% after ureterolysis [25]. Our results (7.4% recurrence of hydroureteronephrosis and 1.9% ureteral fistula at 9 years) are comparable to those reported in the literature. Regarding segmental ureterectomy with anastomosis, our study demonstrated excellent outcomes, with no recurrent hydroureteronephrosis or ureteral complications at a median follow-up of 9 years. This finding is consistent with previous reports showing that segmental ureterectomy with anastomosis is an effective treatment for obstructive UE [16, 27, 29]. Notably, only 20 patients underwent segmental ureterectomy with anastomosis. Given the relatively small sample size of this subgroup, ureteral complications might not be adequately captured. Donval L et al. demonstrated that complex ureteral procedures carried a 3.5% incidence of ureteral fistula [6].
Ureteral endometriosis with hydroureteronephrosis is a rare and challenging condition. However, most existing studies have included patients both with and without hydroureteronephrosis, leaving the specific population with hydroureteronephrosis understudied. Our study addresses this gap by evaluating long-term surgical outcomes exclusively in patients with hydroureteronephrosis. This extensive follow-up is crucial for assessing treatment efficacy and recurrence rates. Furthermore, our findings underscore the importance of multidisciplinary team involvement in managing such complex cases, reflecting current trends in optimizing patient care. This study has several limitations. First, its single-center, retrospective design introduces inherent risks of selection and information bias. Second, our multivariable logistic regression analysis was limited by a small number of events, with only 20 patients who underwent segmental ureterectomy. The variable of intrinsic ureteral involvement was additionally excluded from the model due to zero observed events, further reducing the robustness and generalizability of our results. We acknowledge the risk of model overfitting. Third, due to the retrospective study design and long enrollment period (2004–2024), complete and accurate postoperative renal function data were unavailable for analysis. Additionally, this retrospective cohort spanning 2004–2024 lacked standardized preoperative imaging protocols. Key imaging characteristics for surgical decision-making, including lesion size, extent of ureteral involvement, circumferential encasement, and imaging predictors of intrinsic disease, were incompletely documented. Missing systematic imaging data limits the clinical applicability of our treatment strategy. Future prospective studies incorporating standardized endometriosis ultrasound and MRI protocols are needed to establish more precise and generalizable selection criteria.
Conclusion
In conclusion, ureteral endometriosis with hydroureteronephrosis often lacks urinary symptoms, with only a minority of lesions being intrinsic subtypes, and is almost always associated with ovarian endometriomas or other pelvic deep endometriosis. After careful patient selection, 73% of subjects underwent ureterolysis with nodule excision and demonstrated acceptable long-term outcomes over a median follow-up of 9 years, with a 7.4% recurrence rate of hydroureteronephrosis and a 1.9% incidence of ureteral fistula. Segmental ureterectomy with anastomosis was reserved for refractory cases, specifically those with intrinsic lesions, previous endometriosis surgery, or failed preoperative Double-J stenting. Further prospective studies with larger sample sizes are warranted to verify these findings.
Supplementary Information
Supplementary Material 1: Supplementary Figure 1. Kaplan-Meier analysis for recurrent hydroureteronephrosis.
Acknowledgements
We are grateful to all the patients who participated in our study.
Abbreviations
- UE
Ureteral endometriosis
- DE
deep endometriosis
- GnRHa
Gonadotropin-Releasing Hormone Agonist
- GFR
glomerular filtration rate
- OR
odds ratio
- CI
confidence interval
- ASRM
American Society for Reproductive Medicine
- MRI
Magnetic Resonance Imaging
Authors’ contributions
Xinyue Tang: Methodology, Writing - Original Draft; Zhiyue Gu: Formal analysis; Yi Dai: Formal analysis; Xiaoyan Li: Investigation, Resources; Shiqing Lyu: Investigation, Resources; Yushi Wu: Investigation, Resources; Chenyu Zhang: Data Curation; Qiutong Li: Data Curation; Hailan Yan: Data Curation; Yuanyuan Li: Visualization; Jinghua Shi : Conceptualization, Writing - Review & Editing, Supervision; Jinhua Leng: Conceptualization, Writing - Review & Editing, Supervision, Funding acquisition. All authors were finally approval of manuscript.
Funding
This study was funded by the National Key R&D Program of China (2022YFC2704000), the National High Level Hospital Clinical Research Funding (2022-PUMCH-B-085), and the National Key Clinical Specialty Construction Project (Grant No. U114000).
Data availability
The data of the current study are available from the corresponding author upon reasonable request.
Declarations
Ethics approval and consent to participate
This study was reviewed and approved by the Ethics Committee of Chinese Academy of Medical Sciences & Peking Union Medical College Hospital on 31 October 2023, approval number I-23PJ1807, in accordance with the Declaration of Helsinki. The study has been granted a waiver from requiring written informed consent by the Ethics Committee of Chinese Academy of Medical Sciences & Peking Union Medical College Hospital.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Jinghua Shi and Jinhua Leng are co-corresponding authors.
Contributor Information
Jinghua Shi, Email: elisa_1984@163.com.
Jinhua Leng, Email: lengjenny@vip.sina.com.
References
- 1.Donnez J, Nisolle M, Squifflet J. Ureteral endometriosis: a complication of rectovaginal endometriotic (adenomyotic) nodules. Fertil Steril. 2002;77(1):32–7. [DOI] [PubMed] [Google Scholar]
- 2.Bosev D, Nicoll LM, Bhagan L, Lemyre M, Payne CK, Gill H, et al. Laparoscopic Management of Ureteral Endometriosis: The Stanford University Hospital Experience With 96 Consecutive Cases. J Urol. 2009;182(6):2748–52. [DOI] [PubMed] [Google Scholar]
- 3.Perrone U, Barra F, Anatrà M, Paudice M, Vellone VG, Gullo G, et al. Targeting inflammation in endometriosis: emerging therapeutic options. Expert Opin Investig Drugs. 2025;34(12):995–1009. [DOI] [PubMed] [Google Scholar]
- 4.Habib N, Buzzaccarini G, Centini G, Moawad GN, Ceccaldi P-F, Gitas G, et al. Impact of lifestyle and diet on endometriosis: a fresh look to a busy corner. Prz Menopauzalny. 2022;21(2):124–32. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Cunha FLD, Arcoverde FVL, Andres MP, Gomes DC, Bautzer CRD, Abrao MS, et al. Laparoscopic Treatment of Ureteral Endometriosis: A Systematic Review. J Minim Invasive Gynecol. 2021;28(4):779–87. [DOI] [PubMed] [Google Scholar]
- 6.Donval L, Niro J, Gaillard T, Amari S, Chis C, Poupon C, et al. Nomogram for Predicting a Complex Ureteral Procedure in Pelvic Endometriosis Surgery. J Minim Invasive Gynecol. 2022;29(5):656–64. [DOI] [PubMed] [Google Scholar]
- 7.Arena A, Del Forno S, Orsini B, Iodice R, Degli Esposti E, Aru AC, et al. Ureteral endometriosis, the hidden enemy: multivariable fractional polynomial approach for evaluation of preoperative risk factors in the absence of ureteral dilation. Fertil Steril. 2021;116(2):470–7. [DOI] [PubMed] [Google Scholar]
- 8.Seracchioli R, Raimondo D, Di Donato N, Leonardi D, Spagnolo E, Paradisi R, et al. Histological evaluation of ureteral involvement in women with deep infiltrating endometriosis: analysis of a large series. Hum Reprod. 2015;30(4):833–9. [DOI] [PubMed] [Google Scholar]
- 9.Laganà AS, Garzon S, Franchi M, Casarin J, Gullo G, Ghezzi F. Translational animal models for endometriosis research: a long and windy road. Ann Transl Med. 2018;6(22):431. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Soriano D, Schonman R, Nadu A, Lebovitz O, Schiff E, Seidman DS, et al. Multidisciplinary Team Approach to Management of Severe Endometriosis Affecting the Ureter: Long-term Outcome Data and Treatment Algorithm. J Minim Invasive Gynecol. 2011;18(4):483–8. [DOI] [PubMed] [Google Scholar]
- 11.Alonzo L, Cannella R, Gullo G, Piombo G, Cicero G, Lopez A, et al. Magnetic Resonance Imaging of Endometriosis: The Role of Advanced Techniques. J Clin Med. 2024;13(19):5783. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Alves J, Puga M, Fernandes R, Pinton A, Miranda I, Kovoor E, et al. Laparoscopic Management of Ureteral Endometriosis and Hydronephrosis Associated With Endometriosis. J Minim Invasive Gynecol. 2017;24(3):466–72. [DOI] [PubMed] [Google Scholar]
- 13.Hu Z, Li P, Liu Q, Zhu H, Sun Y, Zhao X, et al. Ureteral endometriosis in patients with deep infiltrating endometriosis: characteristics and management from a single-center retrospective study. Arch Gynecol Obstet. 2019;300(4):967–73. [DOI] [PubMed] [Google Scholar]
- 14.Cavaco-Gomes J, Martinho M, Gilabert-Aguilar J, Gilabert-Estélles J. Laparoscopic management of ureteral endometriosis: A systematic review. Eur J Obstet Gynecol Reproductive Biology. 2017;210:94–101. [DOI] [PubMed] [Google Scholar]
- 15.Alborzi S, Askary E, Poordast T, Alborzi S, Abadi AKH, Shoaii F. Approach to ureteral endometriosis: A single-center experience and meta-analysis of the literature. J Obstet Gynecol Res. 2023;49(1):75–89. [DOI] [PubMed] [Google Scholar]
- 16.Leonardi M, Espada M, Kho RM, Magrina JF, Millischer A-E, Savelli L, et al. Endometriosis and the Urinary Tract: From Diagnosis to Surgical Treatment. Diagnostics. 2020;10(10):771. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Ceccaroni M, Ceccarello M, Caleffi G, Clarizia R, Scarperi S, Pastorello M, et al. Total Laparoscopic Ureteroneocystostomy for Ureteral Endometriosis: A Single-Center Experience of 160 Consecutive Patients. J Minim Invasive Gynecol. 2019;26(1):78–86. [DOI] [PubMed] [Google Scholar]
- 18.Billone V, Gullo G, Conti E, Ganduscio S, Burgio S. G B, Minilaparoscopic Versus Conventional Laparoscopic Hysterectomy: Insights from a Single-Center Retrospective Cohort Study with Legal Considerations. Medicina (Kaunas, Lithuania). 2025;61(7). [cited 2026 June 10]. Available from: https://pubmed.ncbi.nlm.nih.gov/40731845/. [DOI] [PMC free article] [PubMed]
- 19.Muñoz JL, Jiménez JS, Tejerizo A, Lopez G, Duarte J, Sánchez Bustos F. Rectosigmoid deep infiltrating endometriosis and ureteral involvement with loss of renal function. Eur J Obstet Gynecol Reproductive Biology. 2012;162(2):121–4. [DOI] [PubMed] [Google Scholar]
- 20.Jadoul P, Feyaerts A, Squifflet J, Donnez J. Combined laparoscopic and vaginal approach for nephrectomy, ureterectomy, and removal of a large rectovaginal endometriotic nodule causing loss of renal function. J Minim Invasive Gynecol. 2007;14(2):256–9. [DOI] [PubMed] [Google Scholar]
- 21.Chatroux LR, Einarsson JI. Keep your attention closer to the ureters: Ureterolysis in deep endometriosis surgery. Best Pract Res Clin Obstet Gynecol. 2024;95:102494. [DOI] [PubMed] [Google Scholar]
- 22.Barra F, Scala C, Biscaldi E, Vellone VG, Ceccaroni M, Terrone C, et al. Ureteral endometriosis: a systematic review of epidemiology, pathogenesis, diagnosis, treatment, risk of malignant transformation and fertility. Hum Reprod Update. 2018;24(6):710–30. [DOI] [PubMed] [Google Scholar]
- 23.Chapron C, Chiodo I, Leconte M, Amsellem-Ouazana D, Chopin N, Borghese B, et al. Severe ureteral endometriosis: the intrinsic type is not so rare after complete surgical exeresis of deep endometriotic lesions. Fertil Steril. 2010;93(7):2115–20. [DOI] [PubMed] [Google Scholar]
- 24.Nezhat C, Falik R, McKinney S, King LP. Pathophysiology and management of urinary tract endometriosis. Nat Rev Urol. 2017;14(6):359–72. [DOI] [PubMed] [Google Scholar]
- 25.Mereu L, Gagliardi ML, Clarizia R, Mainardi P, Landi S, Minelli L. Laparoscopic management of ureteral endometriosis in case of moderate-severe hydroureteronephrosis. Fertil Steril. 2010;93(1):46–51. [DOI] [PubMed] [Google Scholar]
- 26.Camanni M, Bonino L, Delpiano EM, Berchialla P, Migliaretti G, Revelli A, et al. Laparoscopic conservative management of ureteral endometriosis: a survey of eighty patients submitted to ureterolysis. Reprod Biol Endocrinol. 2009;7(1):109. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Gennaro KH, Gordetsky J, Rais-Bahrami S, Selph JP. Ureteral Endometriosis: Preoperative Risk Factors Predicting Extensive Urologic Surgical Intervention. Urology. 2017;100:228–33. [DOI] [PubMed] [Google Scholar]
- 28.Ghezzi F, Cromi A, Bergamini V, Serati M, Sacco A, Mueller MD. Outcome of laparoscopic ureterolysis for ureteral endometriosis. Fertil Steril. 2006;86(2):418–22. [DOI] [PubMed] [Google Scholar]
- 29.Butticè S, Laganà AS, Mucciardi G, Marson F, Tefik T, Netsch C, et al. Different patterns of pelvic ureteral endometriosis. What is the best treatment? Results of a retrospective analysis. Arch Ital Urol Androl. 2016;88(4):266. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Supplementary Material 1: Supplementary Figure 1. Kaplan-Meier analysis for recurrent hydroureteronephrosis.
Data Availability Statement
The data of the current study are available from the corresponding author upon reasonable request.