Intraosseous Anomalous Drainage Seen in a Patient with Severe Varicose Vein: A Rare Anatomical Variant

Introduction: Varicose veins are enlarged and tortuous veins. They are present in around 10 to 40% of the population aged 30 to 70 years. There are many etiologies of varicose veins such as valvular incompetence, venous hypertension, and inflammation. The symptoms include aching, burning, discomfort, and pruritus. These symptoms usually worsen with prolonged standing. Varicose veins can progress into chronic venous disease and patient can present with leg heaviness, fatigue, hyperpigmentation, edema, and ulceration. The possible complications are ulcers, thrombosis, and infections. Clinical presentation and venous duplex ultrasonography are usually sufficient to make the diagnosis. Varicose veins can be treated surgically or by nonsurgically such as compression stockings, sclerotherapy, radiofrequency ablation, or laser therapy. Intraosseous anomalous venous drainage is a rare anomaly with only 48 cases reported in the literature so far. Most of the time, it is seen affecting the tibia in one side.

Case Report: A 38-year-old lady known case of hypothyroidism, dyslipidemia, and obesity presented to our emergency department complaining of mild left lower limb pain for 1 week. The patient denied any history of trauma or pervious surgeries. However, she had the same episode of pain 15 years ago and was unable to bear weight. The episode was treated with local injection and it resolved completely. On inspection, there was erythema and mild swelling over anteromedial aspect of left lower extremity. On palpation of anterior aspect of lower third of left tibia, there was a firm mobile mildly tender mass immediately under the swollen erythematous area. The patient had an X-ray of left lower extremity which showed a small cortical defect at the anteromedial aspect of mid left tibia. This raised a suspicion for possible osteoid osteoma. Further evaluation with CT scan revealed a tubular structure crossing through the cortex of anterior mid shaft of left tibia with intramedullary continuation superiorly and exiting through a defect at posterior superior aspect. It appeared to be connected to subcutaneous varicose veins. The patient had an MRI to confirm the nature of the abnormal vessel which showed diffuse subcutaneous varicose veins with prominent pretibial varices which are directly connected to the anomalous intraosseous left tibia vein.

Discussion: There have been 48 reported cases of intraosseous venous drainage of varicose veins in the lower extremities so far. Most of the cases were involving the tibia and were unilateral; only one case was reported to be in the fibula. It usually occurs at the tibial draining vein perforating through the anterior cortex. Our case was similar to the majority of cases in that it was involving unilateral tibia and the perforating vein seen in the anterior cortex. There are different hypothesis trying to explain the ethology varicosis in the intraosseous perforating veins. For example, some authors believe that it is preexistent to the presentation because some patients were asymptomatic and did not complain of pain. In our case, we didn’t have previous radiographs to evaluate. However, the patient recalled a similar episode 15 years prior which was treated conservatively. Intraosseous varicose veins can be diagnosed with color Doppler ultrasonography demonstrating reflux. However, cross-sectional imaging is important to differentiate varicose veins from other differential diagnoses such as arteriovenous malformation, arteriovenous fistula, or hemangioma. CT scan and MRI usually show a dilated intraosseous vein with direct connection to surrounding varicose veins. However, MRI is preferred due to better soft-tissue resolution and absence of radiation.

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Artikel online veröffentlicht:
14. Dezember 2021