Coil protection using small helical coils for wide-neck intracranial aneurysms: a novel approach

Parent Artery Complex Coil Protection for Side-Branched Wide-Neck Aneurysms

This study aimed to validate the usefulness of parent artery complex coil protection for the treatment of wide-neck, side-branched, and ruptured aneurysms. A microcatheter was first introduced into the aneurysmal sac, and another microcatheter was introduced into the parent artery or near the orifice of the branch artery. A framing coil was deployed partially from the first microcatheter, and a protection coil was deployed from the second microcatheter to prevent protrusion of the first framing coil to the parent artery and side branches. After the first framing coil insertion, the protection coil was withdrawn to confirm the stability of the framing coil and blood flow. The procedures with this technique were successful for 3 patients. Parent artery complex coil protection can be an effective and safe coil embolization technique for the preservation of parent and side branch arteries and an alternative method for emergent ruptured cases.

Cerebral Aneurysm Coil Embolization with a Coil-Assisted Technique Using a Small-Diameter Helical Coil

Objective

We introduce a coil-assisted technique using a small diameter helical coil to preserve a branch artery in the aneurysm neck or dome during coil embolization of a cerebral aneurysm.

Case Presentations

We report three cases that were treated with the coil-assisted technique. Using this method, the branch artery was preserved with a small diameter helical coil that was placed to support another frame coil. The first case was a ruptured internal carotid artery-posterior communicating artery (IC-Pcom) aneurysm, the second case was a ruptured anterior communicating artery aneurysm, and the third case was an unruptured IC-Pcom aneurysm, with branching of the Pcom, A2, and Pcom, respectively, from the neck or dome of the aneurysm. We were able to preserve the branch artery in all cases.

Conclusion

This technique is feasible and safe for coil embolization of intracranial branch-incorporated aneurysms. The technique is especially useful for preserving branch arteries that are difficult to preserve by conventional techniques.

Endovascular interventions in management of renal artery aneurysm

Renal artery aneurysm (RAA) is a rare disease. With modern non-invasive imaging modalities, the disease is being increasingly diagnosed. It is a slow-growing aneurysm with high mortality in the event of rupture; especially in pregnant females for in which case patients were treated surgically. With advances in endovascular therapy, numerous techniques have been employed to manage complex RAA in artery bifurcation, branch and segmental arteries with excellent technical and clinical success. The various recent techniques include the use of flow diverter stents, remodelling with stent-assisted coil embolization (SACE), balloon-assisted coil embolization (BACE), selective embolization with coils-sac packing, inflow occlusion and coil trapping and selective embolization with liquid embolic agents-hystroacril and onyx. A combination of stent-graft with liquid embolization and liquid with microcoil embolization has been advocated with success. The most common complication encountered is renal infarction. This is mostly without impairment of renal function and secondary to embolization. Endovascular therapy has shorter operative time, less blood loss, shorter intensive care stay, done under conscious sedation and is associated with lesser postoperative morbidity compared to surgery. Reduction in hypertension, improvement of renal function and symptoms has been seen in most studies. Endovascular management of RAA has become the management of choice even with complex anatomy and technically challenging lesions.

[Endovascular Treatment of Cerebral Aneurysms: Technical Options in Coil Embolization]

Since the endosaccular coil embolization technique was introduced as an alternative for treating selected patients with aneurysms, it has become a mainstay of treatment for cerebral aneurysms. In lesions with a neck larger than the aneurysmal body, an irregular shape, or arterial branches incorporated within the sac, endovascular treatment using detachable coils are traditionally contraindicated because of technical difficulties. Coil embolization has evolved as a result of both the development of related devices and the introduction of technical improvements using various devices. Use of various technical and device options can make endovascular treatment of cerebral aneurysms safer and can widen the treatment indications. Various technical options, including the technical modification of device-assisted techniques, will be presented, and the related practical points will be discussed in this issue.

Precision microcatheter shaping in vertebrobasilar aneurysm coiling

BACKGROUND

Inventing an optimal curve on a microcatheter is required for successful intracranial aneurysm coiling. Shaping microcatheters for vertebrobasilar artery aneurysm coiling is difficult because of the vessel's long, tortuous and mobile anatomy. To overcome this problem, we devised a new method of shaping the microcatheter by using the patient's specific vessel anatomy and the highly shapable microcatheter. We report our preliminary results of treating posterior circulation aneurysms by this method.

METHODS

An unshaped microcatheter (Excelsior XT-17; Stryker Neurovascular, Fremont, CA, USA) was pretreated by exposure to the patient's vessel for five minutes. The microcatheter was placed in the vicinity of the targeted aneurysm and was left in contact with the patient's vessel before extraction. This treatment precisely formed a curve on the microcatheter shaft identical to the patient's vessel anatomy. Following the pretreatment, the tip of the microcatheter was steam shaped according to the long axis of the target aneurysm. Five consecutive vertebrobasilar aneurysms were treated using this shaping method and evaluated for the clinical and anatomical outcomes and microcatheter accuracy and stability.

RESULTS

All of the designed microcatheters matched the vessel and aneurysm anatomy except in one case that required a single modification. All aneurysms were successfully catheterized without the assistance of a microguidewire, and matched the long axis of the aneurysm. All microcatheters retained stability until the end of the procedure.

CONCLUSIONS

A precise microcatheter shaping for a vertebrobasilar artery aneurysm may be achieved by using the patient's actual vessel anatomy and the highly shapable microcatheter.

Low-angled microcatheter approach for coil embolization of the anterior choroidal artery aneurysm

PURPOSE

Thromboembolic complication is a serious concern following coil embolization for aneurysms involving the anterior choroidal artery (AChA). To minimize this complication and to improve packing density, we present a technical concept of coil embolization.

METHODS

We attempted packing of the aneurysmal sac by lowering the microcatheter approach angle into an aneurysm to secure AChA origin as well as to improve coil packing density of the aneurysm. This technical concept involves approaching the aneurysm sac with an adjusted shaping of the microcatheter tip to achieve the effect which was not obtained when the microcatheter approach angle into the aneurysm sac was high (≥90°). We evaluated immediate angiographic outcome by the Raymond classification, coil packing density, and follow-up results (modified Rankin Scale (mRS) and recurrence) in seven aneurysms involving AChA in six patients.

RESULTS

We achieved immediate angiographic outcome of the Raymond classes I or II with 31% mean packing density. The AChA origin was preserved without any procedure-related complication. There was neither clinical event (mRS = 0) nor aneurysm recurrence confirmed on the source image of magnetic resonance angiography during 6-9 months follow-up.

CONCLUSIONS

The technical concept of low-angled microcatheter approach can be useful to improve coil packing density and to secure AChA origin when AChA arises near the aneurysm.

Stent-assisted modified coil protection technique for bilobulated aneurysm: technical note

Endovascular treatment of deeply located bilobulated aneurysms in elderly patients is still challenging because of the acute angulation of the carotid siphon and poor microcatheter support. In particular, generating a frame coil to cover each lobe is difficult in bilobulated aneurysms with narrow isthmus in the fused portion. Here, we report a successfully treated bilobulated aneurysm using a modified coil protection technique with stent assistance.

Modified coil protection for proper coil frame configuration in wide-necked aneurysms

INTRODUCTION

Although various protective techniques for treating wide-necked intracranial aneurysms currently exist and continue to evolve, their utility may be limited in some lesions with complex configurations, small-caliber channels, or inherently tortuous vascular patterns. Described herein is a modified coil protection technique as a novel adjunct for proper coil frame configuration.

METHODS

Initially, a microcatheter is passed into aneurysmal sac, and the first coil is inserted to build a frame. Inevitably, some coils may abut opposite poles of aneurysms and protrude into parent arteries. Should this happen, a second microcatheter may be placed at the site of coil protrusion, so that a separate and smaller coil may be partially deployed for protection. A framing coil may then be configured within aneurysmal sac, under protection of the secondary coil. Once the first coil is entirely in place, the remainder of second coil is carefully inserted, and additional coil may be inserted as needed via dual microcatheters.

RESULTS

This technique was successfully applied to 23 saccular intracranial aneurysms of internal carotid (n = 8), middle cerebral (n = 6), anterior cerebral (n = 6), and superior cerebellar artery (n = 3), combining stent protection in two patients and balloon remodeling in one. Selective endovascular treatment was effective as a result. Excellent outcomes were achieved in all patients, with no morbidity or mortality directly related to the modified procedure.

CONCLUSION

As suggested by outcomes of this small study, our modified coil protection method may be a safe option if traditional coiling strategies are not feasible, enabling stable coil frame configuration in wide-necked aneurysms.

Microguidewire protection of wide-necked aneurysms incorporating orifices of tortuous acute-angled vessels: a novel approach

INTRODUCTION

Protective/remodeling techniques for treating wide-necked intracranial aneurysms are constantly sought. However, their utility may be limited in lesions that incorporate the orifice of acute-angled efferent branch vessels. Furthermore, passage of a protective microcatheter may be challenging if a small branch is extremely tortuous. This study was conducted to explore a novel method of treating wide-necked aneurysms, utilizing microguidewire protection.

METHODS

A microcatheter is first passed into parent artery (proximal to aneurysm) to position a microguidewire proximally in the involved branch. A second microcatheter is then inserted into aneurysmal sac. Advancement of the first microcatheter forces the microguidewire to shift, thus covering aneurysmal neck. A framing coil may then be placed within aneurysmal sac, under microguidewire protection. After completing initial coil insertion, easing of tension on the microcatheter allows separation of protective microguidewire and frame coil, confirming stability of the initial coil.

RESULTS

This technique was applied to 11 intracranial saccular aneurysms of M1 segment (n=6), middle cerebral artery bifurcation (n=4), and anterior communicating artery (n=1) with success, combining stent protection in two patients. Coil embolization was thus facilitated, resulting in excellent outcomes for all patients. No morbidity or mortality was directly related to microguidewire protection.

CONCLUSION

Our small study suggests that microguidewire protection may be a safe alternative, if traditional remodeling or protective options are infeasible due to intrinsic vascular properties. This technique is particularly suited for treatment of wide-necked aneurysms where passage of protective microcatheters into involved branches is not achievable.

Coil embolization in precommunicating (A1) segment aneurysms of anterior cerebral artery

INTRODUCTION

Precommunicating (A1) segment aneurysms of the anterior cerebral artery are rare and often pose technical challenges for coil embolization due to their distinctive configurations. Clinical and radiologic outcomes of treating such aneurysms through endovascular coil embolization are presented herein.

METHODS

Data accruing prospectively from May 2002 to August 2013 yielded 48 patients harboring 50 A1 segment aneurysms, each classified as proximal, middle, or distal by location. Clinical outcome of the patients and morphological outcome of the aneurysms were assessed, with emphasis on technical aspects of treatment.

RESULTS

The aneurysms studied occupied either proximal (n = 39), middle (n = 6), or distal (n = 5). Proximal aneurysms were largely directed posteriorly (80 %), and most (97 %) were devoid of branches. Middle and distal aneurysms were associated with the medial lenticulostriate artery, cortical branches, or fenestrations. The preshaped "S" and steam-shaped "S" microcatheters facilitated aneurysm selection in 60 % of lesions. Single-microcatheter technique was most commonly applied for coil embolization (62 %), followed by balloon protection (16 %). Successful aneurysmal occlusion could be achieved in 76 % of the patients, with no procedure-related morbidity and mortality. At final follow-up (mean interval, 29.9 months), stable aneurysmal occlusion was sustained in 93 % of the patients (40/43).

CONCLUSION

A1 segment aneurysms are amenable to safe and efficacious endovascular coil embolization by adjusting procedural strategy to accommodate distinctive anatomic configurations.

Endovascular treatment of wide-neck, ruptured and unruptured aneurysms without supporting devices. A single center experience

Despite of development of various supporting devices in the endovascular treatment (EVT) of wide-neck aneurysms, the procedure remains very challenging. We describe a small series of patients with relatively wide-neck aneurysms treated only by use of 3D coils without supporting devices. In the period July 2011 - August 2012, we treated 23 patients with aneurysm necks > 4 mm or dome/neck ratios < 2. Aneurysms were located in the anterior circulation in 16 patients and in the posterior circulation in seven. The size of aneurysms ranged from three to 21 mm. EVT was achieved by introducing 3D coils of different dimensions in a "Russian doll" fashion. Immediate angiographic results showed complete aneurysm obliteration in 15 patients, small neck remnant in two, and coil protrusion/herniation in four. In one of these cases we had an occlusion of the parent artery and in another case occlusion of the ascending branch (superior cerebellar artery), fortunately both patients remained symptom-free. Clinical results were excellent in 19 patients. One patient developed mild neurologic deficit in the treated territory immediately after the procedure; the patient recovered with mild hemiparesis. One patient developed a delayed stroke in another territory: after treatment the patient left hospital with dysphasia and hemiparesis. The use of 3D coils without neck supporting devices may be a useful alternative in selected cases of wide-neck aneurysms. Larger series with longer follow-up are needed to evaluate the value of this approach.