Agenesis of vena cava inferior (AVCI) and Hypereosinophilic Syndrome (HES): two rare causes of severe thrombosis and its challenging treatment in adolescents

Introduction The agenesis of vena cava inferior (AVCI) is a rare vascular abnormality with an estimated prevalence of up to 1%. The embryological development of VCI is a complex fusion of 3 vein pairs finished in the 8. gestational week. Embryonal, intrauterine or peripartal thrombosis of VCI are discussed to cause AVCI. Patients are usually asymptomatic.

The hypereosinophilic syndrome (HES) is defined as eosinophils > 1.5/nl without parasitic, allergic or other secondary causes. Different organs or organ systems can be involved. The prevalence is unknown.

Method We want to report two rare causes of severe thrombosis and its challenging treatment in adolescents: 3 patients with AVCI and 2 with HES.

Results Patients with AVCI: Three boys, aged 15 years, developed extended deep vein thrombosis of legs and pelvis (pat 1 and 2 both sites extended; 3. extended right site). All three showed an AVCI in diagnostic workup. Except hyperhomocysteinemia in one patient, no hereditary thrombophilia or thrombophilic trigger could be detected. Despite sufficient therapeutic anticoagulation with apixaban, only patient 3 achieved a recanalization. Two patients developed early severe postthrombotic syndrome. Patients with HES: A 16 years old girl was admitted with suspected bleeding in the right breast and left eye, after 4 weeks of anticoagulation with rivaroxaban due to a deep vein thrombosis of the right leg. In the initial blood count 28 eosinophils/nl were detected. The assumed hemorrhage was a skin microthrombosis of the breast, resulted in a large necrosis. Anticoagulation was switched to enoxaparin twice daily. During a break for surgery, she developed an additional thrombosis of the V. ophthalmica superior resulting in a Visus Lux. To avoid long breaks, anticoagulation was bridged with unfractionated heparin for the next multiple surgeries without additional thrombotic events.

A 13 years old boy suffered from an eosinophilic granulomatosis with polyangiitis (EGPA; Churg-Strauß-Syndrome) with skin and lung involvement and 6.690 eosinophils/nl (33 %) in the initial blood count, increasing to 45%. Despite eosinophils <1.0/nl after treatment with steroids, and thrombopenia of 21 platelets/nl, he developed an extended TVT of left leg. Due to thrombopenia, anticoagulation started with half-therapeutic dose tinzaparin, escalating with increasing platelets to full-dose within days. Unfortunately, thrombosis did not improve much after 4-6 weeks treatment.

Conclusion AVCI and HES are two very rare reasons of severe thrombosis in adolescents with therapeutic challenges.

Especially in young males with extended TVT of right or both sites, AVCI should be excluded. Patients with AVCI have a high risk for treatment failure, early post-thrombotic syndrome and relapse of thrombosis after discontinuation of anticoagulation.

HES is associated with a very high risk for thrombosis. A consequent anticoagulation is necessary despite thrombopenia or surgery. Rivaroxaban seemed not sufficient to prevent microthrombosis.

Publication History

Article published online:
20 February 2023