Migrated embolization coil: A rare cause of urinary tract obstruction

Abstract

Refractory bleeding following percutaneous nephrolithotomy (PCNL) is mainly due to formation of pseudoaneurysm. Transarterial embolization is required to control the bleeding in such cases. We report a case of post-PCNL hematuria in whom angioembolization was done. An early erosion of the embolization coil from the renal vasculature into the urinary collecting system occurred, causing urinary tract obstruction and urinary tract infection (UTI). The coil was retrieved ureteroscopically after control of UTI with antibiotics. Migration of embolization coil into urinary collecting system is a rare but important cause of urinary tract obstruction. The treating physician as well as the patient should be aware of this complication.

Erosion of embolization coil into the renal collecting system: Retrograde fragmentation of stone and coil via thulium laser lithotripsy

“…Although the mechanism of coil erosion is not currently well understood due to a sparsity of case reports in the literature, certain mechanisms have been proposed. 4 One possibility involves selection of an embolization coil that is unexpectedly smaller than the arteriocaliceal communication, leading to subsequent coil extrusion through the communication. Another possible mechanism of coil erosion is due to chronic irritation of the coil itself or inflammation from infection, leading to expansion of the arteriocaliceal communication.…”

“… 2 , 3 Specifically, bleeding complications such as pseudoaneurysm formation and arteriovenous fistulas have been reported to occur with an estimated incidence of 0.6 %–1 %. 4 While venous bleeding typically warrants conservative management, arterial hemorrhage occasionally necessitates transarterial embolization with success rates as high as 90 %. 2 Despite the generally accepted safety profile of embolization coil use, rare instances of coil erosion and subsequent migration into the renal collecting system have been reported, with clinical manifestations emerging anywhere from the acute postoperative period to more than 15 years following the procedure.…”

“… 2 Despite the generally accepted safety profile of embolization coil use, rare instances of coil erosion and subsequent migration into the renal collecting system have been reported, with clinical manifestations emerging anywhere from the acute postoperative period to more than 15 years following the procedure. 4 , 5 Standardized guidelines for managing coil erosion are lacking, with reports detailing various innovative approaches to clinical management. 6 Given the low rates of coil erosion and the absence of standardized treatment pathways, we present a case outlining a novel approach to treating embolization coil erosion with recurrent stone formation after PCNL via retrograde thulium laser coil fragmentation.…”