Ovarian vein thrombosis is a partial or complete obturation of the lumen of the venous vessel of the ovary by a blood clot. It is manifested by hyperthermia, painful sensations on the right or left lower abdomen, local abdominal tension, sometimes hematuria. It is diagnosed using CT of the pelvic veins, transvaginal ultrasound, color Doppler mapping, hemostasis system studies. Anticoagulants, antibiotics, and angioprotectors are used for treatment. With progressive and floating thrombi, surgical treatment with thrombectomy, ligation, resection of a thrombosed ovarian vessel is indicated.
I82.8 Embolism and thrombosis of other specified veins
Ovarian vein thrombosis is a rare variant of pelvic phlebothrombosis that occurs after childbirth or abdominal gynecological surgery in patients who suffer from varicose veins of the pelvic network or hereditary defects of the hemostasis system. According to the observations of obstetricians and gynecologists, the prevalence of the disease does not exceed 0.025%. Due to the anatomical features of the passage of blood vessels and the predominant dextraposition of the pregnant uterus, the right ovarian vein is more often thrombosed. Women of reproductive age from 25 to 45 years with pelvic inflammatory diseases, uterine fibroids, internal endometriosis, obstetric injuries are more susceptible to the disease. In 57.6% of patients, multiple blood clots are detected. In 87.9% of cases, blood clots in the ovarian veins are well fixed, not prone to growth and flotation.
The formation of blood clots in the lumen of the venous vessels of the ovaries is associated with the presence of three conditions — a change in rheological parameters of blood, slowing blood flow, damage to the vascular endothelium; at the same time, one of the risk factors may be predominant. Specialists in the field of gynecology identify several causes that contribute to ovarian vein thrombosis:
- Pregnancy and childbirth. The disease occurs in 0.05-0.16% of maternity women against the background of damage to the vascular intima by bacterial agents that caused endometritis, adnexitis, oophoritis. Additional provoking factors are activation of the coagulation system, increased platelet aggregation, three-fold expansion of the lumen of the ovarian veins during gestation with an increase in their capacity by more than 60 times and aggravation of valvular insufficiency.
- Gynecological operations. Up to 25.8% of cytoreductive surgical interventions are complicated by ovarian vein thrombosis. Most likely, this is due to both changes in the hemostasis system, inflammatory and post-traumatic endothelial injuries, and postoperative radiation or chemotherapy. Somewhat less often, thrombosis in the vessels of the ovaries is caused by other abdominal operations on the pelvic organs.
- Varicose veins of the pelvic veins. The prevalence of pelvic varicose veins in women reaches 10.2%, while in 1.3% of patients, ovarian vein thrombosis is determined. Up to 75.8% of cases of the disease occur with grade II-III ectasia, more often in perimenopausal women against the background of a decrease in the diameter of the ovarian veins and a decrease in the linear velocity of blood flow. The risk of developing pathology increases with hereditary collagenoses, angiodysplasia.
- Diseases with increased blood clotting. Ovarian veins are more often thrombosed with genetic abnormalities that lead to a violation of the hemostasis system: antiphospholipid syndrome, antithrombin III deficiency, Leiden factor V mutation, hyperhomocysteinemia, increased factors VIII, XI, protein C, S deficiency, paroxysmal nocturnal hemoglobinuria, hereditary fibrinolytic defects, dysplasminogenemia, etc.
As significant risk factors for the development of ovarian vein thrombosis, heart failure accompanied by general venous congestion, active and passive smoking, taking estrogen receptor modulators (raloxifen, tamoxifen) and COCs with a high content of estrogens, myeloproliferative diseases with increased blood viscosity, state of immobilization, rectal cancer, pancreatic neoplasia, other malignant neoplasms that originate from the endothelium and secrete mucin.
The primary link in the formation of an ovarian vein thrombus is usually a change in the endothelium under the influence of bacterial toxins in inflammatory diseases of the pelvic organs, damaging factors of malignant neoplasia, mechanical influences during operations. Platelets and fibrin aggregate on the damaged area of intima, forming a blood clot (thrombus). With increased clotting and a significant slowdown in blood flow due to varicose veins, heart failure, inactivity, compression of the ovarian vein by a pregnant uterus, pelvic organ tumor, the thrombosis process begins even with minor damage to the endothelial membrane. The formed thrombus can progress (grow along the blood flow into the left renal or inferior vena cava), undergo aseptic autolysis, organization, sewerage, calcification and petrification with the formation of phlebolites.
During the first week after childbirth or surgery, the patient’s body temperature rises to 37-38 ° C. A woman complains of pain of varying intensity in the iliac region on the corresponding side with irradiation in the hypochondrium, lower back. There is weakness, sweating. The pulse rate increases to 100 beats per minute or more. There may be a local tension of the abdominal wall over the affected area, signs of irritation of the peritoneum may be detected. When a disorder occurs in the postpartum period, uterine subinvolution is often noted. Progressive blood clots are characterized by prolonged hyperthermia, chills, and severe intoxication. The clinic of thrombosis of the right ovarian vein in general resembles acute appendicitis, so the diagnosis is often made during surgery. In the right-sided process, blood impurities may appear in the urine due to compression of the affected vessel of the right ureter. In some patients, the symptoms are erased, atypical with a long period of subfebrility, moderate pain syndrome, absence of peritoneal symptoms.
In 4.9-5.1% of cases, there is a progression of thrombosis with a “creeping” spread of the thrombus to the inferior vena cava and left renal veins and subsequent pulmonary embolism with floating blood clots. According to various studies, the incidence of PE in women with postpartum ovarian vein thrombosis reaches 13-33%, while up to 4% of cases are fatal. The disorder is prone to recurrence: in 44% of patients with characteristic symptoms, phlebolitis is detected in the vessels, indicating a previously asymptomatic or clinically pronounced episode of the disease. In rare cases, thrombosis is complicated by swelling of the ovarian tissue.
Due to the low prevalence of thrombosis of this localization, the absence of pathognomonic signs, the possibility of a subclinical course, the correct diagnosis is often difficult. The possible thrombosis of ovarian venous vessels is usually indicated by the connection of the disorder with the postponed childbirth, gynecological surgery. The following methods are used for diagnosis:
- Gynecological examination. With bimanual vaginal palpation, a painful infiltrate is determined in the lower lateral part of the abdomen or the lateral arch of the vagina on the side of the lesion. During rectal examination, pelvic peritoneum soreness is revealed.
- CT venography. Computed tomography of pelvic veins is the gold standard for the diagnosis of thrombosis. Layer-by-layer scanning of vessels after contrast injection allows to assess the condition of the vein lumen, identify blood clots, and establish their characteristics.
- Transvaginal ultrasound of the pelvis. In this study, blood clots in the ovarian vein are visualized as avascular low- or medium-echogenic inclusions, partially or completely blocking the lumen of the vessel. Calcinates (phlebolites) can be determined.
- Color Doppler mapping. During the study of blood flow characteristics in patients with partial thrombosis of the ovarian vein, a parietal filling defect is revealed. With complete thrombosis, the lumen of the vessel does not stain at all.
- Assessment of the hemostasis system. The results of the study of the levels of fibrinogen, antithrombin III, APTT, prothrombin, thrombin time indicate an increase in the blood coagulation system. In the general blood test, the platelet count may change.
Ovarian vein thrombosis is differentiated with acute appendicitis, renal colic, torsion of the leg of an ovarian tumor, septic pelvic thrombophlebitis, venous fullness in pelvic varicose veins, thrombosis of the renal and other deep veins of the pelvis. According to the patient’s indications, consultations of general and vascular surgeons, phlebologist, urologist, nephrologist, oncologist are recommended.
Treatment of ovarian vein thrombosis
Medical tactics are determined by the features of clinical symptoms, the presence or absence of signs of progression or flotation of a blood clot. With erased and moderately pronounced symptoms, partial obstruction of the vessel, a well-fixed blood clot, conservative therapy is possible aimed at relieving inflammation and preventing the spread of thrombosis. Usually , the scheme of drug therapy for thrombotic diseases of the ovarian veins includes:
- Anticoagulants of direct and indirect action. Anticoagulant drugs reduce the activity of thrombin and disrupt the synthesis of prothrombin in the liver. As a result, the growth of a blood clot decreases or completely stops.
- Antibacterial agents. The administration of antibiotics is aimed at combating bacterial infection, which is a key risk factor for thrombosis. Elimination of the pathogen allows protecting the venous endothelium from further destruction.
- Angioprotectors. Intravenous infusion of drugs that protect the vascular wall, improves microcirculation, metabolism, rheological properties of blood. Angioprotective agents enhance the effect of antithrombotic therapy.
The detection of floating blood clots in the ovarian veins, the progression of the process involving the inferior vena cava is the basis for hospitalization of the patient in a specialized vascular hospital and surgical intervention. Most often, the affected vessel is ligated above and below the site of thrombosis, thrombectomy or resection of the vein at the location of the blood clot is performed.
Prognosis and prevention
With timely detection of thrombosis and the correct choice of treatment tactics, the size of the thrombus is significantly reduced, its qualitative organization and calcination or recanalization occurs. In some cases, autolysis of the clot is noted, and the patency of the vessel is completely restored. Timely surgery for thrombosis with signs of progression and flotation reduces the risk of thromboembolic complications. Anticoagulant therapy is recommended for patients with a high risk of thrombosis (varicose veins, subclinical connective tissue dysplasia, hereditary diseases of the coagulation system, obesity) in the postpartum and postoperative period. Preventive measures in such women involve quitting smoking, correcting body weight, and sufficient motor activity.