Pelvic stasis syndrome (PCS), also known as ovarian venous insufficiency or ovarian venous syndrome, is a specific syndrome with chronic pelvic pain CPP as the main clinical manifestation due to chronic stasis in the pelvic veins, and most patients with PCS have ovarian varicose veins. However, due to the diversity and non-specificity of clinical symptoms of PCS and the lack of objective examination indicators, most of the CPP caused by PCS has not been correctly diagnosed so far.
Etiology of PCS.
1. Anatomical and physiological factors.
The pelvic venous reflux system has abundant traffic branches. The ovarian veins are connected to the fallopian tubes and uterine veins through the broad ligament and to the rectal and bladder veins. The left ovarian vein flows back into the left renal vein at right angles, and its venous valve defect rate is 15%, much higher than the 6% on the right side, so the left ovarian vein is prone to reflux. The average diameter of the ovarian vein was found to be 2.6-3.6 mm by imaging and autopsy.
Although asymptomatic ovarian venous reflux and pelvic stasis can occur in women of childbearing age, the probability of PCS compared to those without reflux is as high as Of these, 77% had improved symptoms after ovarian vein ligation, confirming the association of ovarian vein reflux with PCS.
Retroperitoneal vein variation may be another cause of PCS. Normally, the left ovarian vein returns to the inferior vena cava through the renal vein at a pressure of 0-1 mm Hg, whereas left renal vein hypertension can be up to 4 mm Hg. The most common variant is nutcracker syndrome, in which 20% of patients with ovarian vein regurgitation have a similar anatomic variant with early left renal vein hypertension but normal ovarian vein valve function and late valvular insufficiency, leading to PCS.
This is followed by a left renal vein variant, especially in women with post-aortic renal veins who develop ovarian vein regurgitation at a significantly higher rate. Among these, the diameter of the left renal vein was positively correlated with the incidence of left ovarian varices as well as the rate of left ovarian venous regurgitation. In addition, venous hypertension spermatozoa such as portal hypertension and acquired inferior vena cava syndrome can also lead to PCS.
Abnormal uterine position such as posterior tilt and posterior curvature can lead to venous distortion and stagnation and reflux of blood flow; heavy physical labor and long-term standing can lead to poor pelvic venous reflux, thus aggravating ovarian varicose veins; pelvic surgery such as tubal ligation, which damages the tethered vessels and affects utero-ovarian venous reflux, etc. can lead to bruising and PCS.
2. Endocrine and other factors.
PCS occurs only in women of reproductive age, and inhibition of ovarian function may improve symptoms, suggesting that the disease is related to hormone levels. Since no difference was found in the sex hormone levels in peripheral blood between PCS patients and normal women, it is thought that it may be due to disorders in local ovarian hormone levels. Ovarian hormones can inhibit peripheral vasoconstriction against venous pressure and downregulate increased venous pressure by decreasing peripheral blood flow in normal women during the follicular phase; during the luteal phase this stress response is variable and increased blood flow is often seen by Doppler ultrasonography.
This variable response is also seen in the follicular phase of PCS patients, resulting in abnormal dilatation of the pelvic veins and decreased flow contouring. Stagnant blood cells in dilated veins secrete chemokines that upregulate the expression of adhesion molecules at the microcirculatory interface, and neutrophil activation leads to increased postcapillary venous pressure, local tissue hypoxia, and the accumulation of lactic acid and other metabolites that lead to acidosis, further aggravating the vicious cycle of venous dilatation.
Some PCS patients have a familial predisposition and most are particularly sensitive to environmental stress. The pelvic organs consist of richly divided smooth muscle and a large number of blood vessels, and pelvic venous blood flow can change rapidly in response to pressure changes, while the pelvic venous plexus lacks supporting structures, leading to congestion and stasis. Although the emotional psychological scores of patients with CPP due to PCS show anxiety and depression, psychotherapy does not reduce the diameter of dilated veins and improve symptoms. Therefore, it is currently believed that PCS is not a psychogenic disease and that its associated clinical symptoms are a subsequent response to CPP caused by PCS.
Diagnosis of PCS
I. Clinical manifestations.
The relatively characteristic symptoms are “three pains, two more, and one less”, namely: lower abdominal pain, low back pain, and deep intercourse pain; more menstrual volume and vaginal discharge; and less positive signs. Abdominal pain and low back pain are mostly seen in young menstruating women. The lower abdominal pain is variable in intensity and duration, sometimes extending to the thighs and buttocks or manifesting as post-sacral pain, and is aggravated by increased pelvic vein congestion before or during menstruation, fatigue, and uprightness, and is relieved by lying down and elevating the thighs. The pain can be acute or manifested as chronic dull pain, mostly accompanied by heaviness in both lower extremities, and can lead to sudden trigger pain due to postural position changes such as bending over.
Due to increased pelvic congestion during sexual intercourse, 71% of PCS patients suffer from varying degrees of pain during intercourse and 65% from postcoital pain. 66% suffer from varying degrees of dysmenorrhea, which may be accompanied by increased menstruation and vaginal discharge. 24%-45% of patients suffer from bladder irritation and functional gastrointestinal symptoms. Venous stasis leads to the release of vasodilator substances such as substance P and neurokinin A and B from the endothelium and smooth muscle, so this group of patients mostly have symptoms of vegetative dysfunction such as anxiety and depression. Gynecological examination may reveal varicose veins in vulva, thighs and buttocks in some patients, and the cervix may have lifting pain and coloring; the uterus is mobile, mostly posterior and soft; ovarian tenderness has 94% sensitivity and 77% specificity for the diagnosis of PCS.
II. Auxiliary examinations.
1. Non-invasive examinations.
(1) Transabdominal or transvaginal color Doppler ultrasonography: characterized by: pelvic circumferential or linear, dilated veins more than 5 mm in diameter; Doppler ultrasound shows multiple dilated venous echoes around the ovaries and uterus; slow blood flow (3 cm/s) or with terminal reflux; dilated myometrial arch veins connecting bilateral pelvic varices. Improvement in the degree of varicose veins and variable double flow peaks, as well as uterine enlargement, endometrial thickening and ovarian polycystic-like changes can be observed on Doppler ultrasound by the Valsalva method.
(2) CT or MRI: Both CT and MRI show pelvic venous tortuosity with increased dilated and distorted tubular vascular structures in the ovaries, periuterine, broad ligament and paravaginal area. Simultaneous visualization of the ovarian and renal veins may suggest renal vein reflux. Since MRI can visualize vessels at the same circulation time using 3D imaging techniques, whereas CT must scan the upper and lower layers separately at different times, MRI vein visualization has become the preferred noninvasive examination for PCS in recent years. However, all of these examinations require the supine position, thus leaving the tortuous pelvic veins in relative remission in the postural position and therefore masking mild varicosities. It has been reported that for PCS, the sensitivity of MRI, CT and ultrasonography is 58.6%, 12.5% and 20% respectively.
2.Invasive examination: mainly refers to venography and laparoscopy via vulvar, uterine or femoral venipuncture.
(1) Venography: the pelvic vein scoring system of PCS is: when the diameter of ovarian vein is 1-4, 5-8, >8mm, the contrast dwell time is 0, 20, 40s respectively, the pelvic vein stasis and/or ipsilateral or contralateral internal iliac vein mild, moderate or severe stasis are rated 1-3 points respectively, and the score ≥5 points is diagnosed as PCS. in which 6mm diameter of ovarian vein is used as the cutting value, the positive predictive value of up to 83.3%. Currently, pelvic venography in the upright or oblique position or selective ovarian venography is considered the “gold standard” for the diagnosis of PCS. Therefore, even if several tests are negative, as long as the clinical picture is supportive, imaging should be performed to confirm the diagnosis. It is also possible to observe the presence of reflux, contralateral venous imaging, and venous dilatation in the groin, vulva, rectum, and lower extremities.
(2) Laparoscopy: The sensitivity of laparoscopy in diagnosing PCS is 40%, and pelvic veins are seen to be tortuous, thickened or in clusters. It has been reported in the literature that the positive rate of laparoscopic diagnosis of PCS can be improved by reducing intra-abdominal pressure and using Trendelenburg position.
Differential diagnosis of PCS
PCS needs to be differentiated from chronic pelvic inflammatory disease, endometriosis and polycystic ovary syndrome.
PCS has no inflammatory signs and history of acute attacks of chronic pelvic inflammatory disease, no secondary, progressive dysmenorrhea, no small uterus, thin endometrium, abnormal menstruation, amenorrhea, hirsutism and other endocrine abnormalities, and generally does not affect conception. In addition to the more specific ovarian tenderness, there are no pelvic floor tenderness nodules and other positive signs on gynecological examination, and anti-inflammatory treatment is ineffective and may be accompanied by varicose veins in other areas.
Although 50% of PCS can have ovarian polycystic-like manifestations, the polycystic ovaries of PCOS differ in that they are mostly large follicles in clusters of 3-5 with a central distribution in a loose and edematous stroma, and the follicles are significantly larger in diameter than in patients with PCOS. It also needs to be differentiated from pelvic adhesion release, atypical dysmenorrhea, neurosis, urological disorders and gastrointestinal disorders.
Treatment of PCS
(i) General treatment Improve pelvic blood flow status through rest and postural adjustment. Physical exercise should be performed to improve the tortuous torsion of veins by increasing the pelvic muscle tone and correcting the position of uterus, supplemented by psychotherapy.
(ii) Drug treatment
Drug treatment is short-term relief and cannot cure the disease, which can be relapsed after stopping the drug or during the course of taking the drug.
1. Drugs that inhibit ovarian function.
(1) progesterone: progesterone can inhibit ovarian function, increase vascular tone, fast onset of action, the initial treatment can significantly improve symptoms and reduce bruising, remission rate of up to 40%. However, the maintenance time is short, and there is a relapse when the drug is stopped or during the course of taking the drug.
(2) Gonadotropin agonist: compared with MPA, it has strong vasoconstrictor force, which can improve pelvic congestion and relieve painful intercourse.
(2) Drugs to improve vascular tone: Diosmin is a flavonoid compound formed by micronization. 500mg of Diosmin can reduce capillary permeability, increase venous wall tension and capillary resistance, and relieve and inhibit uterine contraction. Symptoms improve significantly after 2-3 months of medication, especially for painful intercourse.
3, other symptomatic drugs: including non-steroidal anti-inflammatory drugs, painkillers, neuromodulation and psychotherapy drugs. It has also been reported that the application of lidocaine and vasodilators for intra-sacral injection and Chinese medicine enema has certain short-term efficacy in relieving symptoms.
(iii) Surgical treatment
1.Uterine suspension and shortening of the fundic ligament: it is suitable for patients with posterior uterus who require preservation of reproductive function, and the purpose of relieving symptoms is to change the position of the uterus and improve pelvic blood stasis.
2. Broad ligament fascial repair: for young PCS patients due to broad ligament laceration, but a cesarean section is required for another pregnancy, otherwise the repair is likely to fail.
3.Ovarian vein ligation and/or resection: ligation of ovarian vein is more effective than resection. In a study of donor kidney women with preoperative presentation of PCS, it was found that 77% of patients had improved symptoms after surgery. Currently, the efficiency of bilateral ovarian vein clamping by laparoscopic titanium clamps can reach 78%.
4. Vascular embolization therapy: Embolization is not only effective and minimally invasive, but also preserves the nerves accompanying the ovarian vessels, with a postoperative remission rate of 80%-100%. Since there are traffic branches between internal iliac vein and ovarian vein, the possibility of varicose vein receiving blood from internal iliac vein cannot be excluded even if the venous valve of ovarian vein is functioning normally. Therefore, some authors have advocated embolization of dilated incompetent ovarian veins, as well as their parallel ovarian branches and branches entering the main trunk or directly into the renal veins.
If there is evidence of traffic between the ovarian and internal iliac plexuses, fractionated internal iliac vein embolization is required to ensure efficacy and reduce recurrence rates. Embolization agents are usually bright anhydrous alcohol, sodium cod liver oil acid (which can be made into a foam embolizer), and spring steel rings. These embolic agents can denature cell surface proteins, which can cause thrombosis. Artificially inject this type of embolic agent for 5 min, and then inject a spring ring that is 1-3 mm larger than the diameter of the dilated vein for consolidation when denaturation is completed. The side effects of vascular embolization are small, with an incidence of 4%, mainly pain-based post-embolization syndrome, thrombophlebitis, recurrence, ectopic embolism, and ovarian spasm, the latter being mostly self-limiting, asymptomatic, and requiring no special treatment.
5. Total hysterectomy with or without bilateral adnexal resection: Due to the presence of pelvic vascular rich traffic branches, simple hysterectomy without bilateral adnexal resection may not be able to completely cut off the vascular traffic, so the efficacy is not satisfactory for the treatment of CPP caused by PCS. The remission rate is 67% with hormonal therapy after surgical resection. The postoperative recurrence rate is 20%, which is considered to be related to the multifactorial pathogenesis of PCS.
6. Other treatment: As mentioned before, anatomical factors have a role in the pathogenesis of PCS, therefore, the presence of anatomical abnormalities should be noted in patients with symptomatic pelvic varicose veins and treated accordingly.
In conclusion, PCS is a common but easily unrecognized by clinicians as a vascular disease with diverse presentations. Diagnosis is facilitated by imaging, and selective ovarian venography is the “gold standard” for diagnosis, while the effectiveness of pharmacological and surgical treatment is uncertain and all treatment options are subject to long-term efficacy. Compared to surgery, vascular embolization is less painful, shorter hospital stay, faster recovery, and less psychologically stressful due to embolization, especially for emotionally stressed and sensitive patients. It has now become the preferred treatment for this disease.