Pelvic Congestion Syndrome

Etiology

Pelvic venous insufficiency is due to the incompetency of the internal iliac vein, the ovarian vein, or both. It is often the underlying cause of pelvic congestion syndrome. Nearly 10% of women suffer from ovarian varices. Of this 10%, about 60% have pelvic congestion syndrome.[2]

The exact etiology of pelvic congestion syndrome is unclear. It is most likely dependent on multiple factors. The congestion of the pelvic veins can be due to hormones, insufficiency of the valve, and venous obstruction. The release of pain-inducing substances due to increased dilatation of the veins along with stasis is a likely cause of the pain in PCS.[3]

Epidemiology

Premenopausal multiparous women are mainly affected by pelvic congestion syndrome.[4] There has been no reported occurrence of the syndrome in menopausal women.[5] In patients with presenting complaints of chronic pelvic pain, the prevalence of the disease is nearly 30%.[6]

Pathophysiology

In pelvic vein insufficiency, the abnormal dilation of the interlinked venous channels of the internal iliac veins and the ovarian veins is often implicated. The ovarian plexus drains into the ovarian veins on both sides. The hemorrhoidal, utero-ovarian, sacral, and vesicular venous plexuses drain into the internal iliac veins. The broad ligament has both the internal iliac and ovarian veins system running through it.[1]

There can be incompetence of the internal iliac veins and the inferior vena cava. However, most of the cases of the pelvic varices are identified in the ovarian veins. Moreover, about 60% of these develop pelvic congestion syndrome.[7] In the majority of the cases of pelvic congestion syndrome, incompetency of the internal pudendal and broad ligament parametrial branches are involved. The pelvic venous reflux into the lower limb or vulvar varicosities is often associated with the incompetency of the branches of the circumflex femoral and obturator veins.[8]

The primary vein insufficiency is due to either the absence of the venous valves or the incompetency of the valves. In such patients, the congenital absence of the ovarian valves has been reported in 6% of patients on the right side and 13% to 15% on the left side. There are incompetent valves in 35% to 46% of women on the right and 41% to 43% on the left side. The inclination of multiparous women to develop PCS can be due to the 50% increased pelvic vein capacity due to the physiological changes during pregnancy. This can, in turn, lead to retrograde blood flow and incompetency of the valves. Even 6 months after pregnancy, these vascular changes can persist.[9]

The secondary pelvic vein incompetence is often due to the external compression of the vein causing venous outflow obstruction. Different causes of external compression include the nutcracker phenomenon, also known as left renal vein entrapment syndrome. This phenomenon is due to the compression of the left renal vein between the superior mesenteric artery and the abdominal aorta. Similarly, the compression of the left common iliac vein by the right internal iliac artery in May-Thurner syndrome can also lead to such results.[10][11]

Regional overload in the venous channels can lead to pelvic venous congestion. This regional overload might be due to left renal vein thrombosis (with renal cell carcinoma), tumor thrombosis in the inferior vena cava, cirrhosis, congenital malformations of arteriovenous and venous channels, and retro aortic left renal vein.[12] 

Complete resolution of symptoms after menopause indicates the influence of hormones on pelvic congestion syndrome. Estrogen is a venous dilator and can thus produce the venous dilation implicated in the pathophysiology of the PCS.[5]

History and Physical

The concurrent presence of venous varices with pelvic pain in premenopausal women does not always mean that they are causally related. Even in asymptomatic females, the dilation and incompetency of pelvic veins are common findings. This creates a challenge in identifying which patients have chronic pelvic pain due to pelvic congestion syndrome. 

The pain associated with PCS presents as a dull ache or a sensation of heaviness in the pelvis. It can last 3 to 6 months and can be unilateral or bilateral. However, the pain can switch from one side to the other. Any factor increasing the abdominal pressure (walking, postural changes, lifting, and longtime standing position) can increase the intensity of pain. It is often exacerbated before or during the menstrual period. The intensity of pain worsens with each subsequent pregnancy, and during or after sexual intercourse. The time of the day also affects the intensity with pain being worse at the end of the day.[13]

If the findings of characteristic pelvic pain are present, physical examination can help in formulating the final diagnosis. The uterine tenderness, ovarian tenderness, and cervical motion tenderness on direct palpation during bimanual examination in a patient presenting with a complaint of chronic pelvic pain support the diagnosis of PCS. 

In a study with 57 females suffering from pelvic pain, the combination of a history of postcoital pain with tenderness over adnexa during physical examination came out to be 77% specific and nearly 94% sensitive for differentiating pelvic congestion syndrome from other pathologies of pelvic origin.[6]

Evaluation

The presence of characteristic pelvic venous changes on imaging supports the diagnosis but is not necessary for forming the final diagnosis. Dilated ovarian veins with incompetency of the valves is also a common finding in asymptomatic women.[14] 

For patients with PCS, in whom an intervention is being planned, require evaluation for pelvic venous reflux with ultrasound, retrograde internal iliac or ovarian venography, computed tomography (CT), or magnetic resonance (MR) imaging.[15]

Ultrasound

The first line imaging study for pelvic congestion syndrome is pelvic ultrasound. Ultrasound helps rule out the presence of pelvic masses or uterine problems as the underlying cause for pelvic pain. Using color-Doppler and conventional B-mode of ultrasound, the pelvic anatomy, ovarian changes, uterine enlargement, and dilated uterine and ovarian veins can be evaluated.[16] 

Retrograde flow of blood with an increase in the size of the left ovarian vein and a decrease in velocity of the blood flow can be observed using ultrasonography. Enlarged, tortuous pelvic venous channels can be noted. The incompetency of valves in the pelvic varicose veins can be noted using Valsalva's maneuver. These varicoceles will show variable duplex waveform on such maneuvers. Polycystic changes of the ovary are also seen in patients with pelvic congestion syndrome.[3][6]

Computed Tomography and Magnetic Resonance

The anatomical details of the pelvic vasculature along with the tissue of the pelvic cavity can be easily visualized with computed tomography and magnetic resonance imaging. Since CT utilizes radiation, it is not recommended in premenopausal women.[17]

For diagnosing pelvic vasculature varices, magnetic resonance venography is a good modality. It is a noninvasive imaging technique with low risk. But the specificity of this imaging modality for venous pathologies is low since the patient is in a supine position for this examination.[18]

The direction and velocity of flow in different vascular channels can be assessed with phase-contrast velocity mapping, which is an MRI-based technique. This technique can be used to evaluate pelvic veins.[19] 

Venography

The gold standard for diagnosing pelvic congestion of the vasculature is ovarian and iliac catheter venography. Ovarian veins are catheterized by approaching via percutaneous jugular and femoral pathways. The distension of the venous channels is better assessed when a venogram is done during Valsalva. Venographic diagnostic findings of PCS that can be seen include incompetent pelvic veins (with diameter more than 5-10 mm), and congestion of flow in venous channels of ovarian, pelvic, vulvovaginal, and thigh veins. Venous reflux in ovarian veins can also be noted.[17]  

Laparoscopy

Chronic pelvic pain is a major cause of gynecologic diagnostic laparoscopies. According to certain reports, more than 40 percent of such laparoscopic procedures are due to chronic pelvic pain.[20] The rate for the occurrence of pathological findings identified on laparoscopies on women with chronic pelvic pain range between 35% and 83%. In 20% of these cases, pelvic congestion is also identified.[21]

Treatment / Management

Medical management should be the first-line treatment for PCS. This is due to decreased complications of medical management as compared to invasive procedures. Gonadotropin-releasing hormone agonists, danazol, combined oral contraceptives, progestins, phlebotonics, and non-steroidal anti-inflammatory drugs are a few treatment options that have shown effective management for the pain in PCS.[22] Etonogestrel implant, goserelin, and medroxyprogesterone acetate have also been successful in alleviating the pain associated with PCS.[3] Improved pain relief is observed when medroxyprogesterone is given along with psychotherapy.[23] Goserelin, a GnRH agonist, has better results in controlling the pain as compared to medroxyprogesterone acetate, but it cannot be continued beyond 1 year due to it being a GnRH agonist.[3] (A1)

Ligation of incompetent ovarian veins can lead to favorable results. In nearly 75% of women, ligation of the incompetent ovarian or pelvic vessels leads to the resolution of the symptoms. Gynecologists have used bilateral salpingo-oophorectomy and hysterectomy as a treatment for pelvic congestion syndrome, but the results were not favorable.[15] (A1)

The ablation of incompetent veins can also be achieved by endovascular procedures using a minimally invasive approach. These procedures can be performed in an outpatient setting leading to comparatively quick recovery and fewer complications.[24] Different agents like platinum embolization coils, glue, foam, or liquid sclerosants can be used for causing endothelial damage in the incompetent vessels.[25](B2)

Differential Diagnosis

The list of the differential diagnoses for pelvic congestion syndrome is vast. It includes diseases of the urinary tract, gastrointestinal tract, musculoskeletal disorders, disorders of neurological origin, gynecological problems, and mental health disorders. Painful bladder syndrome, pelvic inflammatory disease, interstitial cystitis, endometriosis, pelvic neuralgia, irritable bowel syndrome, myofascial pain, and pelvic floor myalgia are the common causes of chronic pelvic pain. Formulating the accurate diagnosis of the underlying cause of chronic pelvic pain is difficult even with the use of laparoscopic and diagnostic radiological tests.[1][2]

Prognosis

The women afflicted with pelvic congestion syndrome report resolution of symptoms in nearly 68.2%-100% of the cases with treatment. However, with pelvic embolization, 6% to 31.8% have reported no significant relief of pain associated with pelvic congestion syndrome.[26]

Complications

With surgical treatments for pelvic congestion syndrome, there is an increased rate of recurrent pelvic pain (20%) or residual pain (33%). Moreover, there is often aesthetic damage and longer hospitalizations with surgical treatments.[27] The loss of gonadal function leading to the need for hormonal replacement is also an important complication of ovarian vein ligation and oophorectomy.[28]