The first case of postpartum ovarian vein thrombosis was described by Austin in 1956 [
2]. Since then many authors have addressed this rare clinical condition. The 14 individual cases that have been reported so far are presented in Table
1. Pathophysiologically, OVT is explained by Virchow's triad, because pregnancy is associated with a hypercoagulable state, venous stasis due to compression of the inferior vena cava by the uterus and endothelial trauma during delivery or from local inflammation. The estimated incidence of OVT ranges between 0,05 and 0,18% of pregnancies with the majority of affecetd women being in the 3
rd or 4
th decade of their life. In 80-90% of the cases the right ovarian vein is the one affected, commonly 2-15 days following delivery. Cesarean delivery, also increases the risk of thrombosis to 1-2% and multiparity has been identified as a risk factor for thrombosis in general [
3,
4]. Rare causes of this entity are pelvic inflammatory disease, malignancies, Crohn's disease and pelvic surgical procedures [
5,
6]. Patients with malignant tumors, particularly those undergoing chemotherapy, are at risk for developing OVT, but is often asymptomatic and thrombus may resolve without any treatment [
6]. Hypercoagulation conditions as systemic lupus erythematosus, antiphospholipid syndrome, presence of factor V Leiden, paroxysmal nocturnal haemoglobinuria, hyperhomocysteinaemia, protein C and S deficiency and heparin induced thrombocytopenia are all reported as risk factors for OVT [
1,
7].
Table 1
Individual case reports of ovarian vein thrombosis.
| Postpartum | 1 | Anticoagulation/antibiotics | No |
| Postpartum | 1 | Anticoagulation/antibiotics and IVC Greenfield filter | No |
| Postpartum | 1 | Anticoagulation/antibiotics | No |
| Postpartum | 1 | Anticoagulation/antibiotics | Yes |
| Crohn's disease | 1 | Anticoagulation/antibiotics and Crohn's disease management | No |
| Malignant tumor | 6 | Anticoagulation or observation | Νο |
| Postpartum | 1 | Anticoagulation/antibiotics | Νο |
| Postpartum | 2 | Anticoagulation/antibiotics | Νο |
| Postpartum | 1 | Anticoagulation/antibiotics | No |
Common symptoms and signs of OVT include lower abdomen or flank pain, fever and leukocytosis usually within the first ten days after delivery [
8]. A rare but characteristic coexistence is OVT with right ureteral obstruction and hydronephrosis, because anatomically the right ovarian vein crosses in front of the right ureter at the level of the L4 vertebra on its way to the inferior vena cava [
8].
Diagnostic imaging can be performed using ultrasound, CT scan or MRI examinations, with magnetic resonance angiography having the best sensitivity and specifity. However the latter exam is reserved for doubtful situations and the two former are the most commonly used due to cost and speed considerations [
9].
Diagnostic dilemma always occurs because of the rarity of this clinical entity. In cases when lower abdominal pain is the main symptom acute appendictitis cannot be excluded-leading to a negative appendectomy, as in our patient.
Anticoagulation and antibiotics is the mainstay of treatment of OVT. The morbidity of OVT arises from complcations such as sepsis, extension of the thrombus to the inferior vena cava and renal veins, and pulmonary embolism. The mortality of OVT can be as high as 5% and is mostly due to pulmonary embolism the incidence of which is reported to be 13.2% [
10]. If the patient fails to respond to standard medical treatment or severe complications occur, options range from placement of an IVC Greenfield filter to hysterectomy and thrombectomy or even ligation of the inferior vena cava [
11]. There are no recommendations for prophylaxis during a subsequent pregnancy, unless a hypercoagulable state is proved.