The Case

You’re getting in that first sip of coffee at 7:05 a.m. as your colleague continues his sign-out. “Room 24 is a 38-year-old healthy female with right lower quadrant abdominal pain. Pelvic ultrasound was negative. Labs were normal: no leukocytosis, normal basic metabolic panel and liver function tests. Pregnancy test and urinalysis were negative; she had her tubes tied last year. She’s awaiting a CT to rule out appendicitis,” he says.

“Slam dunk,” you think. Follow up the CT, reassess the patient, and dispo accordingly. No problem!

An hour later, the CT returns: no appendicitis, no inflammatory changes. As you prepare the discharge, a quick skim of the radiology report reveals, “Long segment of thrombus in the right ovarian vein.”

You reassess the patient, and she is still having pain but is feeling better overall after a tiny dose of morphine. Her abdominal exam is reassuring, and her vitals remain normal. You politely advise her that you will get back to her and her husband shortly with the treatment plan.

What on earth do you do about ovarian vein thrombosis?

Background

If you haven’t seen a case of ovarian vein thrombosis (OVT), that’s because it is exceedingly rare, especially in its idiopathic form. The diagnosis was first identified in 1956, published in a case report by Austin.¹ Our colleagues in obstetrics should recognize this condition more readily. They see it in the peripartum period (most commonly postpartum) as well as in patients who have had recent gynecologic (or abdominal) surgery, pelvic inflammatory disease, or gynecologic malignancy.² Outside of these conditions, the diagnosis of OVT is considered idiopathic and tends to be picked up incidentally, as in this case. The exact prevalence of idiopathic OVT is uncertain; it is only reported in case series. In one study, investigators uncovered six cases of OVT in the 2.5-year study period. Two of those cases were discovered incidentally.³

Presentation

OVT most commonly presents with an acute onset of abdominal or flank pain. Literature suggests that the pain will be on the right side 90 percent of the time, theoretically owed to the right ovarian vein following a longer course with incompetent valves.⁴ This laterality makes the condition a mimicker of more common etiologies such as acute appendicitis, renal colic, pyelonephritis/urinary tract infection, and inflammatory bowel disease.⁵ In the case of peripartum disease, the patient may frequently present with fever and leukocytosis in a similar manner as endometritis. In postpartum patients, expect a higher frequency in cesarean section patients (1–2 percent) than in those following vaginal delivery (0.05–0.18 percent).⁶

Diagnosis

OVT is at risk of becoming lost in the long differential diagnosis for abdominal and flank pain in the emergency department, especially when fever and/or sepsis physiology are present. Clearly, the emergency physician will be on the lookout for the more common etiologies mentioned above. In this case, the emergency physician was appropriately suspicious for acute appendicitis. Although not useful in idiopathic cases, which will usually be tricky, a careful history may help elucidate some risk factors. Consider OVT in the recent postpartum patient (although endometritis is far more likely), after recent hysterectomy or other gynecologic surgery, or when there is a concern for undiagnosed malignancy. Physical exam findings may reveal fever, tachycardia, abdominal tenderness, and signs of peritonitis, all of which are nonspecific for this condition. A detailed pelvic examination may reveal findings of pelvic inflammatory disease, which may be the cause of OVT, as well as adnexal mass.
The emergency physician may be unlikely to diagnose OVT based on the history and physical examination alone. Fortunately, contrast-enhanced CT scanning of the abdomen and pelvis provides excellent sensitivity (100 percent) and specificity (99 percent) for the condition.⁷ It may also be diagnosed on MRI or with pelvic ultrasound but with markedly decreased sensitivity. In this case, pelvic ultrasound with Doppler did not detect OVT or any signs of ovarian vascular congestion or enlargement.

Management

When the patient with OVT presents in overt sepsis, empiric antibiotics, fluids, labs, and appropriate cultures are the mainstay as well as cross-sectional imaging to rule out various causes of intraabdominal pathology. When OVT is detected in this fashion, inpatient management should also include systemic anticoagulation, typically with heparin.