Rescue stenting in endovascular treatment of acutely ruptured cerebral aneurysms

Parent artery stenting as a rescue management for stretched coils during cerebral aneurysms embolization: Report of three cases and review of literature

BACKGROUND

Displacement of a stretched coil into the parent artery during intracranial aneurysm coiling is a challenging situation where the risk of acute intravascular thrombosis might be a life-threatening condition. The usual way of management is coil snaring, yet in some cases, it might not be feasible to retrieve the coil. Parent artery rescue stenting had already been described as a way of management in acutely thrombosed parent arteries during aneurysm coiling.

CASE REPORTS

We present three cases with an inadvertent displacement of the unraveled coils into the parent artery for which rescue stenting was carried out to crush the coil against the vessel wall aiming to eliminate its thrombogenic effect. Our preliminary experience is that rescue stenting of the parent artery for stretched coil could be a convenient effective option particularly in case of failed/risky snaring with no notable immediate or long-term complications.

REVIEW AND DISCUSSION

We review the reported cases of stretched coils with or without further unraveling and fracture and discuss the possible consequences, salvage methods, and clinical outcomes. Neurointerventionists should be aware of this complication and get acquainted with bailout strategies.

Verapamil eluting stents as a possible treatment for vasospasm after subarachnoid hemorrhage

Objective

The only pharmacologic prophylaxis for cerebral vasospasm after subarachnoid hemorrhage is oral nimodipine. A novel way to mitigate this risk may be to design a drug eluting stent that elutes verapamil over the time period typically associated with vasospasm. In this study, we explore different methods of coating nitinol stents with a bioabsorbable polymer and determine the release profile of various verapamil coated stents for the potential treatment of vasospasm.

Methods

Nitinol stents were coated with different concentrations of poly(lactic acid-co-glycolic acid) (PLGA) in chloroform solution and using three coating techniques: dip coating, spin coating, and electrospinning. Morphology of the coatings were studied with scanning electron microscopy. 12 verapamil eluting stents were then prepared using different verapamil concentrations and coatings with different numbers of layers. Drug release behaviors were studied using UV spectroscopy for 21 days.

Results

Electrospinning at 20% w/v resulted in a smooth uniform coating without significant surface irregularities, and may be the most effective technique to coat stents. Stents with a single layer of PLGA/verapamil coating showed a two phase release profile (initial burst release followed by a slow rate of release) whereas stents with a bilayer coating showed a lower level of initial release followed by a slower sustained release phase.

Conclusions

Development of verapamil eluting stents that elute drug over the time course typical of cerebral vasospasm, and for either immediate or prophylactic treatment, is technically feasible. Further in vitro and in vivo studies are required to determine whether this can improve the outcome of patients after subarachnoid hemorrhage.