What causes pelvic congestion syndrome?

Causes of Pelvic Congestion Syndrome

Pelvic congestion syndrome (PCS) is primarily caused by venous valvular insufficiency in the pelvic veins, particularly the ovarian veins, leading to retrograde blood flow and venous engorgement. 1

Primary Causes

Venous Insufficiency

• Incompetent venous valves: The most common underlying cause of PCS is incompetent or dysfunctional valves in the ovarian veins, allowing blood to flow backward and causing venous dilation 1, 2
• Gonadal vein reflux: Reflux in the ovarian (gonadal) veins leads to pelvic venous engorgement and formation of pelvic varices 3
• Median sacral vein incompetence: In some cases, an incompetent median sacral vein can contribute to PCS, especially in recurrent cases after treatment 4

Mechanical Venous Obstruction

• Nutcracker syndrome: Compression of the left renal vein (typically between the superior mesenteric artery and aorta) with an incompetent gonadal vein valve 1, 3
• May-Thurner configuration: Compression of the left iliac vein by the right iliac artery, leading to reflux into the ipsilateral internal iliac vein 3
• Nonthrombotic iliac vein lesions (NIVL): Can be associated with PCS 1

Risk Factors

Hormonal Factors

• Multiparity: PCS occurs more commonly in multiparous women 5, 2
• Hormonal influence: Estrogen can cause relaxation of the venous walls and contribute to venous insufficiency 2

Anatomical Factors

• Pelvic venous anatomic variants: Variations in pelvic venous anatomy can predispose to PCS 1
• Cross-pelvic collaterals: Large cross-pelvic collaterals can contribute to the development of PCS 4

Clinical Presentation

PCS typically presents with:

• Chronic pelvic pain (lasting more than 6 months) 2, 6
• Pain exacerbated by:
  • Prolonged standing 5
  • Sexual intercourse (dyspareunia) 5, 2
  • Premenstrual period 5, 2
• Vulvar, perineal, or thigh varices 5, 6
• Associated symptoms may include:
  • Post-coital ache 2
  • Dysmenorrhea 2
  • Bladder irritability 2
  • Rectal discomfort 2

Diagnostic Considerations

• First-line diagnostic method: Ultrasound with Doppler to document engorged periuterine and periovarian veins (>8mm) and evaluate flow patterns 1
• Gold standard: Trans-catheter venography remains the definitive diagnostic modality 2
• Other imaging modalities: CT with contrast and MRI/MR Angiography can provide additional information on venous anatomic variants 1

Important Clinical Pitfalls

1. Underdiagnosis: PCS is frequently overlooked as a cause of chronic pelvic pain, leading to delayed treatment and unnecessary patient suffering 2, 6

2. Misdiagnosis: It's essential to rule out other causes of chronic pelvic pain, including:

   • Chronic pelvic inflammatory disease
   • Endometriosis
   • Adhesive disease
   • Interstitial cystitis/bladder pain syndrome
   • Musculoskeletal disorders 1

3. Asymptomatic venous engorgement: Pelvic venous engorgement and gonadal vein reflux can be seen in patients without pelvic pain, making a detailed history and physical examination crucial for proper diagnosis 3

4. Recurrence after treatment: PCS can recur after ovarian vein embolization through other tributaries in the venous network, such as the median sacral vein 4