Pelvic Congestion Syndrome: Definition and Pathophysiology
Pelvic congestion syndrome (PCS) is a chronic pelvic pain condition caused by engorged and refluxing pelvic veins, characterized by dilated periuterine and periovarian veins (≥8 mm diameter) with retrograde flow in the ovarian veins. 1
Core Pathophysiological Mechanisms
Ovarian vein incompetence is the predominant cause, characterized by retrograde flow in dilated ovarian veins due to valvular insufficiency, with slow or reversed blood flow (<3 cm/s). 1
Estrogen overstimulation contributes significantly by promoting increased blood flow to pelvic organs and indirectly regulating nitric oxide-mediated smooth muscle relaxation in pelvic vessels, which leads to venous pooling. 1
Many women with PCS have morphologic findings of polycystic ovarian syndrome (enlarged ovaries with exaggerated central stroma and multiple small peripherally located follicles) without the typical clinical features of hirsutism and amenorrhea. 1
Symptoms may subside after menopause in some women due to decreased estrogen stimulation. 1
Mechanical Causes of Venous Obstruction
Nutcracker syndrome occurs when the left renal vein is compressed between the superior mesenteric artery and aorta, causing increased pressure that transmits to pelvic veins via the left ovarian vein. 1
May-Thurner syndrome, characterized by compression of the left common iliac vein by the right common iliac artery, can cause venous obstruction leading to pelvic congestion. 1
Nonthrombotic iliac vein lesions (NIVL) cause focal stenosis of the common iliac vein or inferior vena cava, with intravascular ultrasound often revealing severe compression not apparent on standard venography. 1
Internal iliac vein reflux can contribute to pelvic congestion independently. 1
Clinical Presentation
PCS accounts for 16-31% of cases of chronic pelvic pain, typically diagnosed in the third and fourth decades of life, predominantly in multiparous women. 2
Chronic pelvic pain lasting more than 6 months is the hallmark symptom, which is intermittent or continuous and may worsen during menses, after prolonged standing, or after a hard day's work. 3, 4
Associated symptoms include dyspareunia (painful intercourse), post-coital ache, dysmenorrhea, urinary urgency, bladder irritability, rectal discomfort, and constipation. 3, 4, 5
PCS frequently coexists with lower extremity varicose veins of pelvic origin, particularly affecting the posterior thigh, vulva, and inguinal regions through venous escape points from the internal iliac system. 1
The combination of gonadal vein reflux and nonthrombotic iliac vein lesions has been associated with more severe symptoms. 1
Diagnostic Approach
Ultrasound with Doppler is the initial imaging study of choice, demonstrating engorged periuterine and periovarian veins (≥8 mm), low-velocity flow, altered flow with Valsalva maneuver, and retrograde (caudal) flow of the ovarian veins. 1
MRI/MR angiography has diagnostic performance comparable to conventional venography and can directly demonstrate ovarian vein reflux. 1
CT with contrast may demonstrate engorged periuterine and periovarian veins and can identify venous anatomic variants and compression of the left renal vein. 1
Trans-catheter venography remains the gold standard modality for definitive diagnosis and is undertaken as an immediate precursor to ovarian vein embolization. 4
Treatment Options
Ovarian vein embolization is the most effective first-line treatment, with early substantial pain relief observed in 75% of women, which generally increases and sustains over time, with technical success rates of 96-100% and long-term symptomatic relief in 70-90% of cases. 6, 4
Internal iliac vein embolization (in addition to ovarian vein embolization) has been shown to be safe and effective in treating pelvic venous insufficiency and reducing pelvic pain. 1, 6
Sclerosants (sodium tetradecyl sulfate, polidocanol) show significant symptomatic improvement of approximately 75% in patients with PCS. 6
Laparoscopic ovarian vein ligation has been reported to result in complete resolution of symptoms in all 23 patients treated. 6
Left renal vein stenting is increasingly preferred over open surgical approaches for nutcracker syndrome due to lower morbidity, demonstrating remission of pelvic venous symptoms. 6, 7
Pelvic floor rehabilitation therapy, including myofascial manipulation and uterine conditioning, should not include standard Kegel exercises, which can worsen symptoms in some patients. 6
Manual physical therapy techniques, including maneuvers that resolve pelvic, abdominal and/or hip muscular trigger points, lengthen muscle contractures, and release painful scars, are appropriate for patients with pelvic floor tenderness. 6
Amitriptyline may be beneficial for chronic pain management in patients with PCS. 6
Behavioral modifications, including avoiding tight-fitting clothing and managing constipation, may help manage symptoms, as constipation may worsen symptoms in some patients. 6
Clinical Pitfalls
There is a lack of clear definition and high-quality evidence in the clinical domain of pelvic venous disorders, with significant barriers to complete acceptance of both the existence, investigation and management of the condition due to lack of prospective, multicentre randomized controlled trials. 1, 4
PCS is frequently underdiagnosed despite its significant prevalence, as patients present to multiple specialists including general practitioners, gynecologists, vascular specialists, pain specialists, gastroenterologists and psychiatrists. 4, 2
Pelvic pain and venous varices are often both present in premenopausal women, but not necessarily causally related, as incompetent and dilated pelvic veins are a common finding in asymptomatic women. 5
Under-diagnosis of this condition can lead to anxiety and depression in affected women. 4