Endovascular pharmacomechanical thrombolysis-a novel treatment for circumaortic left renal vein and inferior vena cava thrombosis in a paediatric patient with relapsing nephrotic syndrome

Abstract

While venous thromboembolism (VTE) in children with nephrotic syndrome (NS) remains an uncommon clinical entity, it represents one of the disease's most severe and potentially fatal complications. As such, clinicians and radiologists must maintain a high level of suspicion for VTE and low threshold for performing diagnostic imaging studies in children with NS, thereby ensuring prompt diagnosis and early management initiation. Despite the recent advances and development of image-guided endovascular procedures, there remains a marked paucity of literature describing the use of endovascular intervention for the treatment of acute VTE in NS, and a clear consensus on the gold standard for management has yet to be fully elucidated. Moreover, given the relative rarity of this complication in children as opposed to adults, no prior report has been made in which a paediatric patient has undergone endovascular intervention for acute VTE in the setting of NS. This report will outline the use of endovascular pharmacomechanical thrombolysis and thrombectomy as a novel treatment option for acute circumaortic left renal vein and inferior vena cava thrombosis in a paediatric patient with relapsing NS.

Figure 1.

Multiplanar intravenous contrast-enhanced CT of the abdomen and pelvis demonstrates enlargement of the left kidney, moderate left-sided perinephric free fluid (a) and a delayed left nephrogram (white arrow—b). Acute thrombus was noted in a tortuous circumaortic left renal vein, which extends into the inferior vena cava and measures up to 12.0 cm in craniocaudal dimension (black arrows—b, c). Subsequent anteroposterior projection cavogram demonstrates inferior vena cava thrombus, which extends downstream to the approximate level of the right renal vein (black arrow—d).

Figure 2.

By utilizing the neck access, an inferior vena cava filter was inserted above the level of the inferior vena cava thrombus (white arrow—a), which acted as a safeguard against potential periprocedural thromboembolic events. Hand injection venography via the retroaortic limb of the left renal vein demonstrated complete occlusion of the left renal vein (white arrow—b) with venous return occurring through numerous capsular collaterals extending along the left lateral aspect of the spine (black arrows—b, c).

Figure 3.

Angiography before (a) and after (b–d) Angiojet pulse spray tissue plasminogen activator thrombolysis and balloon angioplasty demonstrate progressive recanalization of the left renal vein, with opacification now seen in the anterior and posterior limbs of the renal vein and flow extending into the IVC (black arrows—b, c). Pigtail angiography performed following aspiration thrombectomy shows wide patency of the left renal vein (black arrows—d) with a large thrombus having been captured by the in situ IVC filter (white arrow—d), demonstrating the utility and efficacy of prophylactic filter placement when performing such intervention.