Residency · Residency · Interventional Radiology
Pelvic Congestion Syndrome: Ovarian Vein Embolization
Definition and Pathophysiology
Pelvic congestion syndrome (PCS) is defined as chronic pelvic pain lasting more than 6 months attributed to ovarian and pelvic venous insufficiency. The condition is analogous to lower extremity varicose veins: incompetent ovarian vein valves lead to retrograde flow and pelvic venous engorgement. Dilated ovarian and pelvic veins (greater than 6-8 mm) cause venous congestion, inflammation, and pain. PCS predominantly affects premenopausal multiparous women and is rare after menopause due to decreased pelvic blood flow. The left ovarian vein drains into the left renal vein via a longer, more vertical course (analogous to the left gonadal vein in males), while the right ovarian vein drains directly into the IVC. Left-sided predominance occurs due to the Nutcracker phenomenon (left renal vein compression between the SMA and aorta) and the longer left gonadal vein course.
Clinical Presentation
The hallmark is chronic, dull, aching pelvic pain that worsens with standing, at the end of the day, during menstruation, and after intercourse (postcoital ache). Deep dyspareunia is common. Vulvar and perineal varicosities may be visible in the vulva, perineum, or upper thigh. Patients may also report urinary urgency and frequency from venous compression of the bladder, and lower extremity varicose veins that recur after treatment due to a pelvic source of reflux. PCS is a diagnosis of exclusion, requiring that endometriosis, fibroids, ovarian pathology, and GI and urologic causes be ruled out.
Diagnostic Controversy
The central debate is whether dilated pelvic veins on imaging correlate with clinical symptoms. Many asymptomatic women have dilated ovarian veins on cross-sectional imaging, and there are no universally accepted diagnostic criteria or imaging thresholds. Diagnosis requires both compatible symptoms and imaging evidence of pelvic venous insufficiency.
Diagnostic Workup
Ultrasound
Transvaginal ultrasound may show dilated parauterine and periuterine veins (greater than 6 mm) with reversed flow in the ovarian veins, though sensitivity is limited and findings are operator-dependent. It is often the initial imaging study.
Cross-Sectional Imaging
CT venography or MR venography demonstrates dilated ovarian veins (greater than 6-8 mm), pelvic varicosities, and possible contributing factors such as Nutcracker syndrome or May-Thurner. MR venography is preferred because it avoids radiation in young women and can show time-resolved venous flow. Key findings include dilated ovarian veins, parametrial/periuterine varicosities, vulvar/perineal varicosities, and Nutcracker anatomy.
Catheter Venography (Confirmatory)
Selective ovarian and internal iliac vein catheterization demonstrates reflux (retrograde contrast flow in the ovarian vein with Valsalva) and documents the venous congestion pattern and all contributing veins. This is performed at the time of planned embolization.
Embolization Technique
Access
Right internal jugular vein or right common femoral vein access is used, with the jugular approach providing easier catheterization of the left ovarian vein.
Procedure
The procedure begins with selective catheterization of the left renal vein to identify the left ovarian vein origin. Selective ovarian venography with Valsalva demonstrates reflux. A microcatheter is advanced distally into the ovarian vein to the level of the pelvic brim or deeper. Embolization proceeds from distal to proximal using coils (most commonly used, deployed throughout the ovarian vein), sclerosant foam (sodium tetradecyl sulfate 3% or polidocanol, injected into pelvic varicosities for chemical sclerosis providing more distal coverage than coils alone), glue (NBCA, less commonly used for rapid occlusion), or vascular plugs (for proximal occlusion of larger veins). The procedure is repeated on the right ovarian vein catheterized from the IVC. Internal iliac vein tributaries (pudendal, obturator, or gluteal veins) are evaluated and embolized if contributing to pelvic varicosities. Completion venography confirms occlusion.
Bilateral Approach
Most operators embolize both ovarian veins because bilateral disease is common even if symptoms lateralize. Internal iliac vein tributaries should also be assessed and embolized if refluxing.
Outcomes
| Outcome Measure | Result |
|---|---|
| Technical success | >95% |
| Clinical improvement (pain reduction) | 70-85% |
| Complete symptom resolution | 50-60% |
| Recurrence rate | 5-15% |
| Effect on fertility | No adverse effect demonstrated |
| Common cause of recurrence | Untreated internal iliac vein tributaries |
Technical success exceeds 95%. Clinical improvement with significant pain reduction is reported in 70-85% of patients, and complete symptom resolution in 50-60%. Recurrence rate is 5-15%, often due to untreated internal iliac vein tributaries or recanalization. No adverse effect on fertility has been demonstrated because ovarian blood supply is maintained through other collateral pathways.
Post-Procedure Care
Most patients are discharged the same day. Mild pelvic pain and low-grade fever are common for 1-3 days as part of a post-embolization syndrome. NSAIDs are used for pain management. Follow-up at 3-6 months assesses symptom response, and repeat imaging is performed only if symptoms persist or recur.
The Diagnostic Criteria Controversy
The lack of standardized diagnostic criteria is the biggest challenge in PCS. Many gynecologists are skeptical of the diagnosis, and some studies show no correlation between vein diameter and symptom severity. Multidisciplinary evaluation involving gynecology, IR, and pain management is recommended. Patient selection is the most important factor determining outcomes, with patients who have classic symptoms and concordant imaging findings responding best.
<image>Anatomic illustration of pelvic venous anatomy relevant to pelvic congestion syndrome. An anterior view of the female pelvis showing bilateral ovarian veins (left draining into the left renal vein, right draining into the IVC), dilated parauterine and periuterine venous plexus, and communication with the internal iliac vein tributaries (pudendal, obturator veins). Vulvar and perineal varicosities are shown extending inferiorly. The left ovarian vein is notably dilated with incompetent valves illustrated. An inset shows the Nutcracker anatomy with the left renal vein compressed between the SMA and aorta.</image>
<image>Sequential illustration of bilateral ovarian vein embolization for pelvic congestion syndrome. Four panels: (1) Selective left ovarian venography via jugular access showing a dilated, refluxing left ovarian vein with filling of pelvic varicosities during Valsalva; (2) Microcatheter positioned distally in the left ovarian vein with coils being deployed from distal to proximal; (3) Foam sclerotherapy being injected into the pelvic varicosities through the microcatheter before proximal coil placement; (4) Completion venography showing complete occlusion of both ovarian veins with no residual reflux into the pelvis. Labels identify the renal vein, ovarian vein, pelvic varicosities, coils, and sclerosant foam.</image>
<image>MR venography findings in pelvic congestion syndrome. Two panels: (1) Coronal MR venogram showing bilaterally dilated ovarian veins (>8 mm diameter) with tortuous course and filling of pelvic varicosities; (2) Axial image at the level of the uterus showing dilated parauterine veins and parametrial varicosities. Arrows indicate the dilated veins with measurements annotated. A companion normal anatomy panel shows non-dilated ovarian veins for comparison.</image>
Clinical Pearls
PCS is a diagnosis of exclusion, requiring that endometriosis, fibroids, and other gynecologic causes be ruled out before attributing chronic pelvic pain to venous congestion. Imaging findings of dilated pelvic veins alone are not sufficient for diagnosis; symptoms must correlate. Both ovarian veins and internal iliac vein tributaries should always be embolized for a complete treatment. Sclerosant foam combined with coils provides more thorough coverage of small pelvic varicosities than coils alone. No adverse effect on fertility has been demonstrated with ovarian vein embolization. Recurrence is often due to untreated internal iliac vein tributaries, so a thorough initial treatment reduces retreatment rates. Multidisciplinary evaluation improves patient selection and outcomes.
References
- Defined by the CIRSE Standards of Practice on Pelvic Congestion Syndrome. Cardiovasc Intervent Radiol 2022
- Defined by the SVS/AVF Clinical Practice Guidelines on Pelvic Venous Disorders. J Vasc Surg Venous Lymphat Disord 2024
- Defined by the SIR Practice Guideline on Ovarian Vein Embolization. J Vasc Interv Radiol 2018
- Defined by Defined by Defined by Defined by Meissner MH et al. The venous clinical severity score and the role of pelvic venous disease. J Vasc Surg Venous Lymphat Disord 2021
