What are the primary causes of pelvic congestion syndrome?

Primary Causes of Pelvic Congestion Syndrome

Pelvic congestion syndrome (PCS) is primarily caused by valvular insufficiency in pelvic veins, hormonal factors (particularly estrogen overstimulation), and mechanical venous obstruction leading to dilated and refluxing pelvic veins. 1

Pathophysiological Mechanisms

• Venous Valvular Insufficiency: Incompetence of valves in the ovarian and pelvic veins leads to retrograde blood flow and venous engorgement 2
• Hormonal Factors: Estrogen overstimulation plays a significant role in the development of pelvic venous disorders, which explains why symptoms may subside after menopause when estrogen levels decrease 1
• Mechanical Venous Obstruction: Compression of veins (such as left renal vein or left common iliac vein) can cause increased pressure in the pelvic venous system 3, 2
• Anatomical Factors: Nonthrombotic iliac vein lesions (NIVL) can contribute to pelvic venous congestion by causing obstruction 3

Specific Causes

• Ovarian Vein Incompetence: Reflux in the ovarian veins (particularly left gonadal vein) is a common finding 1, 2
• Internal Iliac Vein Reflux: Incompetence in the internal iliac veins can contribute to pelvic congestion 3, 1
• Nutcracker Syndrome: Compression of the left renal vein between the superior mesenteric artery and aorta can lead to pelvic congestion 3
• May-Thurner Syndrome: Compression of the left common iliac vein by the right common iliac artery can cause venous obstruction leading to pelvic congestion 3
• Median Sacral Vein Incompetence: Though rare, an incompetent median sacral vein can cause or contribute to PCS 4

Risk Factors

• Multiparity: Multiple pregnancies increase the risk of developing PCS 2, 5
• Polycystic Ovarian Morphology: Many women with PCS have enlarged ovaries with exaggerated central stroma and multiple small peripherally located follicles, though without the typical clinical features of PCOS 1
• Hormonal Influences: Fluctuations in estrogen levels can exacerbate symptoms, explaining why symptoms are often worse during the premenstrual period 2, 6

Clinical Associations

• Lower Extremity Venous Disease: PCS can be associated with lower extremity varicose veins, particularly those of pelvic origin 3
• Chronic Pelvic Pain: PCS contributes to 30-40% of cases of chronic pelvic pain where no other cause is identified 5
• Pelvic Venous Disease and Nonthrombotic Iliac Vein Lesions: The combination of gonadal vein reflux and NIVL has been associated with more severe symptoms 3

Important Considerations

• Multifactorial Etiology: The precise cause of PCS is likely multifactorial, involving a combination of valvular insufficiency, venous obstruction, and hormonal influences 6
• Diagnostic Challenges: Not all women with dilated pelvic veins have symptoms, making it important to correlate imaging findings with clinical presentation 7, 6
• Potential for Recurrence: PCS can recur after treatment if all contributing factors are not addressed, such as when only the ovarian veins are treated but other pathways like the median sacral vein remain incompetent 4

Understanding these various causes is essential for proper diagnosis and treatment planning, as different etiologies may require different therapeutic approaches.