I. Characteristics The etiology of pelvic congestion syndrome (PCS) is complex. The pelvic venous reflux is affected by the changing hormonal levels (especially after pregnancy) and the congenital lack of venous valves in the pelvic veins, resulting in retrograde reflux of blood from the ovarian veins into the internal iliac veins of the pelvis, causing pelvic venous stasis syndrome. The pelvic vein stasis syndrome is most often seen on the left side of the pelvis. Swelling and dilation of the stagnant veins, damage to the vessel wall, and release of a series of inflammatory mediators can cause pain. Nutcracker syndrome (see later) is a specific form of disease that causes pelvic venous stasis syndrome. The diagnosis of pelvic venous stasis syndrome is often difficult due to the non-specific nature of the symptoms. The pain caused by pelvic vein stasis syndrome may manifest as unilateral or bilateral acute or chronic abdominal pain. Patients present with painful intercourse that may last for hours or days and may be relieved by lying down and resting. The above history combined with the presence of pressure pain at the ovarian projection point has a sensitivity of 94% and a specificity of 77% for the diagnosis of pelvic venous stasis syndrome, while other guiding signs include cervical pain and cervical congestion. Pelvic venous stasis syndrome is commonly seen in patients with a family history of varicose veins, combined vulvar varicose veins, or a history of multiple births. Other causes include side effects of medications, and the influence of physical or psychological factors in the patient. After a detailed history and physical examination, ultrasound, CT, MRI, angiography under magnetic resonance, and laparoscopy are all helpful in the diagnosis of pelvic venous stasis syndrome. Other abnormalities are often detected on imaging, such as polycystic ovaries (56% of patients with pelvic venous stasis syndrome have polycystic ovaries) and adenomyosis. Venography of the reproductive organs can reveal the extent of varicose veins in patients with pelvic venous stasis syndrome. The catheter is not placed immediately after successful femoral or jugular vein puncture cannulation and imaging reveals the left ovarian vein to avoid missing the diagnosis of Nutcracker syndrome. Contrast is injected into a vein near the left ovarian vein while the patient is in an upright position doing Valsalva maneuvers to observe the presence of blood regurgitation in the left ovarian vein. If no blood regurgitation is found, the diagnosis of pelvic venous stasis syndrome is unlikely and a catheter is placed from that point into the right ovarian vein. If rapid placement is not possible or no blood regurgitation is seen, no venous regurgitation may exist or the degree of regurgitation is mild and the examination can be end the examination. If significant left ovarian vein reflux is found (refluxed ovarian vein >8 mm in diameter), the diagnosis of pelvic venous stasis syndrome is likely. After the diagnosis of pelvic vein stasis syndrome is confirmed, a tube is inserted into the lumen of the abnormal vein if embolization is to be performed. Since the dilated veins are brittle and prone to spasm, the procedure should be performed with care and intermittent injection of contrast agent to select the correct placement route and to further observe the presence of combined femoral or pubic varic veins. Treatment 1. Drug therapy NSAIDs are effective first-line treatment options that can provide short-term relief of pain symptoms, but cannot effectively treat the symptoms of pelvic venous stasis syndrome in the long term. However, if the pain recurs after stopping the medication or the treatment is ineffective, attention should be paid to the treatment of the primary disease. 2.Surgical treatment It is found that 2/3 patients can get symptom improvement or cure after total hysterectomy with hormone replacement therapy, but the cure rate of ovarian vein high ligation is 73% and the efficiency rate is 78%, which is significantly higher than that of hysterectomy with double attachment. Since ovarian vein ligation also cuts off the nerves entering the pelvis, it may lead to recurrence of pelvic vein stasis syndrome. With the development of vascular interventions and their unique characteristics of minimally invasive and effective, surgery is now rarely used in the treatment of pelvic vein stasis syndrome. 3. Vascular interventions Since vascular interventions embolize both the ovarian veins and their traffic branches, avoiding the return of blood to the branch vessels, they can effectively treat pelvic vein stasis syndrome and reduce the recurrence of symptoms. The literature reports that interventional vascular embolization for pelvic vein stasis syndrome has a cure or symptom improvement rate of 73-78%. Early interventional procedures for pelvic vein stasis syndrome were mainly performed with unilateral (mainly left-sided) coil embolization and showed significant reduction in pain symptoms in 66% of patients and partial or no change in symptoms in 33%. The popular procedure in the 1990s was bilateral ovarian vein embolization, but sometimes only left-sided ovarian vein embolization is still performed in some patients because the right ovarian vein is too thin to be detected or cannot be successfully placed. With the increased use of foam sclerosing agents in clinical practice, more and more foam sclerosing agents are being used for ovarian vein embolization. In a study of a larger sample, 106 of 127 patients with pelvic vein stasis syndrome underwent bilateral ovarian vein sclerotherapy + coil embolization and 21 underwent unilateral sclerotherapy embolization, and pain was assessed before and after the procedure using a visual analog score (VAS). The results showed that 83% of the patients had pain relief, 13% had no change in pain level, and 4% had increased pain. The study recommended embolization of the left ovarian vein with gelatin sponge sclerosing agent + coil and, if reflux was also present in the right ovarian vein, embolization of the right ovarian vein with the same embolic agent. If pain is still evident 6 weeks after the procedure, a repeat intervention is recommended to embolize the internal iliac veins bilaterally. Complications of pulmonary embolism after embolization of the ovarian and internal iliac veins are currently uncommon. A small number of patients may experience an increase in pain after embolization, which may be related to vascular spasm and damage to the vessel wall, and pain caused by embolization can be effectively treated with pain medication alone. Nutcracker syndrome Nutcracker syndrome is a special manifestation of pelvic vein stasis syndrome, because the left renal vein is trapped between the superior mesenteric artery and the abdominal aorta, which leads to the narrowing of the left renal vein, and then causes the vascular flexion and dilation around the left renal vein and leads to the functional disorder of related tissues and organs, manifested as hematuria and blood reflux of the left ovarian vein. Diagnosis of Nutcracker syndrome: 1. symptoms related to hematuria; 2. left-sided back pain; 3. pelvic congestion; 4. pelvic and vulvar varicose veins; 5. CT, MRI, ultrasound and other imaging examinations suggest the presence of left renal vein compression; 6. angiography confirms the presence of left renal vein compression. Nutcracker syndrome can be treated by different surgical procedures, including the establishment of a left renal vein bypass and autologous left renal iliac fossa transposition. However, the number of surgical cases reported in the literature are small and effective treatment needs further study.