Prolapse of the Pipeline embolization device in aneurysms: incidence, management, and outcomes

Spontaneous delayed migration or shortening after pipeline embolization device treatment of intracranial aneurysm: incidence, management, and risk factors

BACKGROUND

Studies reporting spontaneous delayed migration or shortening (SDMS) after treatment with the Pipeline Embolization Device (PED) are limited. This study aimed to evaluate the incidence of SDMS after PED treatment, propose management strategies, and identify the risk factors contributing to its occurrence.

METHODS

We retrospectively reviewed consecutive patients with an intracranial aneurysm (IA) treated with PEDs at three institutions. SDMS was classified as type I or II based on whether the PED covered the aneurysm neck.

RESULTS

The total cohort comprised 790 patients. SDMS was identified in 24 (3.04%) patients. Eighteen of the 24 patients had type I SDMS and did not require retreatment, while the remaining six patients had type II SDMS and all received retreatment. Multivariate logistic regression showed that the difference between the proximal and distal parent artery diameters (DPAD) (adjusted OR 2.977; 95% CI 1.054 to 8.405; P=0.039) and device tortuosity index (DTI) (adjusted OR 8.059; 95% CI 2.867 to 23.428; P<0.001) were independent predictors of SDMS after PED treatment, while the difference in length (DL) (adjusted OR 0.841; 95% CI 0.738 to 0.958; P=0.009) and PED plus coiling (adjusted OR 0.288; 95% CI 0.106 to 0.785; P=0.015) were protective factors.

CONCLUSION

The incidence of SDMS after PED treatment of IA was 3.04%. For patients with type I SDMS with incomplete aneurysm occlusion we recommend continuous imaging follow-up while, for patients with type II SDMS, we recommend aggressive retreatment. The DPAD and DTI were independent risk predictors of SDMS after PED treatment, while the DL and PED plus coiling were protective factors.

Verification of software-based preoperative simulation of flow diverters in clinical cases

OBJECTIVE

The authors sought to verify the use of a preoperative simulation software for the treatment of intracranial aneurysms using flow diverters (FDs) based on three-dimensional rotational angiography (3DRA) data.

METHODS

Based on 3DRA data, the preoperative simulation software (UKNOW) was used to simulate the deployment of virtual FDs. The length and dimensions of virtual and real devices were compared. The deployment plan recommended by the UKNOW software was preliminarily used to complete implantations in the real world. During the experiment, experienced neurointerventional experts were responsible for supervising and judging information such as the length, dimension, and deployment location of the FDs.

RESULTS

This study retrospectively analyzed the data of 29 patients who received FD treatment. There was no statistical difference between the length of the real device and the virtual device (p = 0.6). The dimensions of FDs recommended by the software were consistent with the dimensions used in 24 out of the 29 real cases. In four of the remaining five cases, neurointerventional experts found that the FD dimensions recommended by the software were superior to those were actually used. Thus, the accuracy rate for FD dimension recommendations by the UKNOW software was 96.6% (28/29). Procedures performed in five cases using deployment plans recommended by the UKNOW software all achieved good postoperative results; the deployment positions of the device were reasonable, and all devices showed good wall adherence.

CONCLUSIONS

UKNOW software could accurately simulate the length and deployment position of the real FDs and provide suitable device dimensions.

Multiple telescoping flow diverter technique in endovascular treatment of a vertebrobasilar dissecting aneurysm: case report

A 64-year-old man presented with headache and dizziness. A vertebrobasilar dissecting aneurysm was identified via computed tomography angiography and high resolution magnetic resonance imaging. Perioperatively, standard oral dual antiplatelet drugs were given. Two flow diverters were telespcoped for endovascular treatment of the aneurysm. Postoperatively, there were no signs of cerebral infarction and no new symptoms. At the 6-month follow-up, digital subtraction angiography showed that the aneurysm was almost completely occluded, with no other complications. This case serves as a reference for using the multiple telescoping flow diverter technique to treat vertebrobasilar dissecting aneurysm.

Challenging access during flow diversion treatment of a giant cavernous ICA aneurysm

A man in his 60s presented with severe ophthalmoparesis and loss of visual acuity in his right eye. He was found to have a giant aneurysm of the cavernous internal carotid artery (ICA). Treatment with a flow diverter was recommended. The aneurysm caused matricidal outflow restriction of the ICA. Microwire and microcatheter access through the aneurysm was challenging, requiring multiple wires, stentriever reduction, and more. Eventually, a construct of 3 Pipeline embolization devices was created across the aneurysm. Troubleshooting access across giant aneurysms is an important part of treatment. Informed consent was obtained for the procedure and for publication. The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2258.

The 8-year single-center experience of telescoping flow diverter for complex intracranial aneurysms treatment

OBJECTIVE

Treatment of complex intracranial aneurysms (IAs) is still a challenging thing and this study aims to summarize the experience of telescoping flow diverters (FDs) in treating complex intracranial aneurysms.

METHOD

Between April 2013 to November 2020, 381 IA cases treated by flow diverters (FD) were retrieved from the database of 4988 IA cases, and finally 20 cases treated by telescoping FDs were enrolled for further analysis.

RESULT

Among 20 patients, 15 patients (75.0%) received Tubridge telescoping while 5 patients (25.0%) received PED telescoping. The technical success rate was 100%. The immediate occlusion results were: 7 cases of OKM grade A (35.0%), 11 cases of OKM grade B (55.0%), and 2 cases of OKM grade C (10.0%). No perioperative complications occurred. The clinical follow-up was available in 20 patients (100%) and the follow-up time was 6-96 months. One patient developed massive infarction and the other 19 patients were range between 0 and 2. The angiographic follow-up was available in 17 patients (85%) and the follow-up time was 6-27 months. The occlusion results were: 1 case of OKM grade B (5.9%), 6 cases of OKM grade C (35, 0.3%), and 10 cases of OKM grade D (58.8%). 2 patients (11.8%) developed occlusion of the patent artery.

CONCLUSION

Telescoping flow diverters showed low perioperative complications and high IA occlusion rate when treating complex intracranial aneurysms in follow-up time, which provides an alternative manner beyond conventional strategy for neurosurgeons.

Reconstructive vs Deconstructive Endovascular Approach to Intradural Vertebral Artery Aneurysms: A Multicenter Cohort Study

BACKGROUND

Parent vessel sacrifice (PVS) has been a traditional way of treating complex aneurysms of the intradural vertebral artery (VA). Flow diversion (FD) has emerged as an alternative reconstructive option.

OBJECTIVE

To compare the long-term clinical and radiographic outcomes of intradural VA aneurysms following PVS or FD.

METHODS

We retrospectively reviewed and evaluated 43 consecutive patients between 2009 and 2018 with ruptured and unruptured intradural VA aneurysms treated by PVS or FD. Medical records including clinical and radiological details were reviewed.

RESULTS

A total of 43 intradural VA aneurysms were treated during this period. In the 14 PVS patients, the mean follow-up was 19.5 mo, and 71.4% of cases achieved modified Rankin scale (mRS) ≤2 at the last follow-up. A total of 86.5% of cases achieved complete occlusion. There was a 14.3% (2 cases) mortality rate, 14.3% (2 cases) postoperative ischemic complication rate, and 0% postoperative hemorrhaging rate. Retreatment was required in 1 case (7.1%). In the 29 FD patients, the mean follow-up was 21.8 mo, and 89.7% of cases achieved mRS ≤2 at the final follow-up. There was a 3.2% (1 case) mortality rate, 19.4% (6 cases) of postoperative ischemic complications, and 6.5% (2 cases) of postoperative hemorrhagic complications. Complete occlusion was seen in 86.5% patients. No cases required retreatment. Mortality and complication rates were not significantly different between PVS and PED (Pipeline Embolization Device) groups.

CONCLUSION

PVS was associated with comparable intraprocedural complications for VA aneurysms as compared to FD in the largest multicenter study to date. Both procedures have good long-term clinical and radiological outcomes.

Design of Personalized Devices—The Tradeoff between Individual Value and Personalization Workload

Personalized medical devices adapted to the anatomy of the individual promise greater treatment success for patients, thus increasing the individual value of the product. In order to cater to individual adaptations, however, medical device companies need to be able to handle a wide range of internal processes and components. These are here referred to collectively as the personalization workload. Consequently, support is required in order to evaluate how best to target product personalization. Since the approaches presented in the literature are not able to sufficiently meet this demand, this paper introduces a new method that can be used to define an appropriate variety level for a product family taking into account standardized, variant, and personalized attributes. The new method enables the identification and evaluation of personalizable attributes within an existing product family. The method is based on established steps and tools from the field of variant-oriented product design, and is applied using a flow diverter—an implant for the treatment of aneurysm diseases—as an example product. The personalization relevance and adaptation workload for the product characteristics that constitute the differentiating product properties were analyzed and compared in order to determine a tradeoff between customer value and personalization workload. This will consequently help companies to employ targeted, deliberate personalization when designing their product families by enabling them to factor variety-induced complexity and customer value into their thinking at an early stage, thus allowing them to critically evaluate a personalization project.

The Exchange-Free Technique: A Novel Technique for Enhancing Surpass Flow Diverter Placement

Background:

Following flow diverter placement, approximately 20% of intracranial aneurysms remain as residual aneurysms at 1 year. Device malapposition is a cause of residual aneurysms after flow diversion. We present a new and straightforward technique (exchange-free technique [EFT]) to enhance apposition of the surpass flow diverter (SFD), the only over-the-wire flow diverter currently available.

Materials and Methods:

We deployed laser-cut mini stents through the inner deployment catheter of the SFD. This maneuver was performed simply by withdrawing the micro-guidewire from its lumen and replacing it with a mini-stent (stents deliverable through microcatheters with inner diameter of 0.0165 inches), without a need to re-cross the deployed SFD or an exchange maneuver. All aneurysms in which this technique was utilized were retrospectively reviewed.

Results:

Twenty-eight patients (20 females) with 30 treated aneurysms were identified. The mean aneurysm diameter was 10.2 ± 6.6 mm. Technical success rate was 96.6% (29/30 aneurysms). There was no mortality or permanent morbidity related to the procedures. Except for the patient treated for an iatrogenic, surgery-related internal carotid artery pseudoaneurysm who died secondary to consequences of multiple surgeries, no cases of mortality or permanent morbidity were noted. Complete aneurysm occlusion rates were 78.2%, 82.1%, and 95.2% at 0–3, 3–6, and 9–12 months, respectively. None of the patients were re-treated.

Conclusion:

EFT is a simple and fast technique which was not associated with adverse effects in our series. The higher aneurysm obliteration rate obtained with EFT is probably the result of better wall apposition of the SFD.

The POP (Pull on Pipe) Maneuver: A Technical Note for Rescuing a Prolapsed Pipeline Device

BACKGROUND

Flow diverters have revolutionized the treatment of large aneurysms. However, prolapse of the device into the aneurysm is a known complication that may have fatal consequences.

CASE

We present a case of a 21-year-old male with a giant aneurysm located in the cavernous segment of the right internal carotid artery. After Pipeline Embolization Device (PED) deployment, while retrieving the PED wire, the proximal end of the stent shortened, resulting in prolapse of the device into the aneurysm. We utilized the Pull on Pipe (POP) maneuver, characterized by the deployment of a second PED inside the lumen of the prolapsed device and gentle traction to restore the initial flow diverter into its proper position. The maneuver also allows for the immediate deployment of the second PED to improve proximal purchase and overall construct stability.

CONCLUSION

The POP maneuver is a novel strategy for salvaging herniated flow diverters and establishing a more stable PED construct.

Placement of a Stent within a Flow Diverter Improves Aneurysm Occlusion Rates

BACKGROUND AND PURPOSE

Placement of a stent within a flow diverter has been described previously but its consequences have not been analyzed. We evaluated the clinical and angiographic results of stent placement within a flow diverter during the same treatment session.

MATERIALS AND METHODS

All patients treated with a Surpass flow diverter were retrospectively evaluated. Patients with previously deployed stents and procedures in which scaffolding stents, a second flow diverter, or intrasaccular devices were used were excluded. Patient and aneurysm characteristics and clinical and imaging follow-up results were compared between stented and nonstented Surpass flow-diverter groups and stent assisted coiling.

RESULTS

Thirty-five patients (41 aneurysms) were treated with a Surpass flow diverter only (monotherapy group), and in 33 patients (35 aneurysms), a stent was placed within the Surpass flow diverter (stented group). Stents were placed inside the Surpass flow diverter for a variety of reasons at the operator's discretion. No statistical difference was noted between the 2 groups in age, body weight, sex, history of thromboembolic events, smoking, platelet inhibition levels, hypertension, hyperlipidemia, diabetes mellitus, malignancy, and aneurysm location. Aneurysms in the stented group were larger than those in the monotherapy group (14.8 versus 9.1 mm, P < .001). The rate of clinically significant adverse events and complete aneurysm occlusion rates at 0-3 and 3-6 months (73.3% versus 61.3%, P = .31, and 84.8% versus 70.2%, P = .14) were similar. At 9-12 months, a significantly higher proportion of aneurysms in the stented group achieved complete occlusion (93.9% versus 73.2%, P = .019). There was a trend toward a higher obliteration rate on final follow-up in the stented group (93.9% versus 82.9%, P = .14).

CONCLUSIONS

Placement of a stent within a flow diverter increases the rate of aneurysm occlusion. We propose that these results are from improved flow-diverter apposition due to the higher radial force of intracranial stents.

Coiling as a Rescue Strategy for Flow Diverter Prolapse into a Giant Intracranial Aneurysm

BACKGROUND

Up to 3.2% of the adult population has an unruptured intracranial aneurysm (IA). Flow diversion is a relatively new treatment technique that is especially useful for large and morphologically unfavorable IAs.

METHODS

A previously healthy woman aged 32 years presented with a 6-month history of ptosis and ophthalmoplegia of the left eye. A magnetic resonance imaging scan revealed a giant left internal carotid artery aneurysm. She was admitted for treatment using flow diversion. After delivery of the flow diverter (FD), prolapse of the proximal end of the stent into the aneurysmal sac was observed. FD stabilization was achieved by deploying multiple coils through a previously placed microcatheter to push the prolapsed end away from the aneurysmal lumen.

RESULTS

The patient had a favorable outcome, with reduction of preoperative mass effect symptoms and complete obliteration of the aneurysm persisting at the 3-month follow-up.

CONCLUSIONS

Giant IAs remain one of the most daunting clinical problems to treat. FD displacement is a rare (0.5%-0.75%) and possibly fatal complication. Currently, no clinical guidelines exist for its management. Adjunctive coiling is a possible rescue strategy for stabilizing an FD that foreshortened and prolapsed into the aneurysmal sac. Further studies are needed to identify the best approach to this complication.