Optimal pediatric dosing of anti-platelet agents for pipeline stent embolization -a case report and review of the literature

Flow diverter stenting for intracranial aneurysms in the pediatric population: Two case reports and literature review

The Pipeline Embolization Device (PED) is a flow-diverting intraluminal device that is approved for use in adults 18 years or older with internal carotid artery aneurysms. However, it can also be used off-label in pediatric patients with aneurysms that cannot be resolved with traditional endovascular treatments. Herein, we present two cases of flow diversion in the pediatric population with complete obliteration of the aneurysm and excellent outcomes. Flow diversion has been shown to be a safe endovascular option in treating complex aneurysms in children. Larger-sized, multicenter trials are encouraged to compare outcomes between flow diversion and other aneurysm treatment options given the rarity of pediatric aneurysms.

Endoluminal flow diversion as a primary treatment strategy for pediatric traumatic intracranial aneurysms: a case-based review of literature

BACKGROUND

Traumatic intracranial aneurysms (TICAs) constitute a notable portion of pediatric intracranial aneurysms. Their unstable structure dictates a high incidence of rupture or mass effect from enlarging unruptured aneurysms, necessitating prompt diagnosis and treatment. TICAs often lack a true neck or are wide-necked, making them unsuitable for coil embolization and surgical clipping, and their fragile nature poses a risk of rupture during surgical and intrasaccular interventions. Endoluminal flow diverters (FD), deployed without requiring direct access to the aneurysmal sac, have emerged as an appealing sole treatment modality for TICAs. However, the clinical experience with this technique remains limited in the pediatric population.

METHOD

We describe the successful treatment of a paraclinoid TICA in a 4-year-old female using an endoluminal FD alone. Additionally, we conducted a literature review to assess the safety and effectiveness of this treatment modality in pediatric TICAs.

RESULTS

Endoluminal flow diversion led to complete aneurysm obliteration in our case, with no observed complication, at the 9-month follow-up. Our review of the previously reported pediatric TICAs managed by standalone flow diversion highlights this technique as safe, efficient, and promising as a sole treatment modality, particularly in the anterior circulation, with a high rate of persistent total obliteration and a low rate of complications. However, the requirement for long-term antiplatelet therapy with the possibility of frequent dose monitoring and adjustments warrants special attention when using endoluminal FDs. Until guidelines specifically addressing optimal antiplatelet therapy in children with intracranial FDs are formulated, adherence to existing protocols is imperative to avoid in-stent thrombosis.

CONCLUSION

Our literature review and personal experience indicate that endoluminal flow diversion can be a viable treatment approach for pediatric TICAs. However, prospective studies with extensive follow-ups are required to assess the durability of endoluminal FDs in treating pediatric TICAs, considering the long life expectancy of this demographic.

Endovascular Management of Pediatric Traumatic Intracranial Pseudoaneurysms: A Systematic Review and Case Series

OBJECTIVE

This study aims to systematically review the management and outcomes of pediatric patients who develop intracranial pseudoaneurysm (IPA) following head trauma or iatrogenic injury.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic literature review was performed. Additionally, a retrospective analysis was conducted on pediatric patients who underwent evaluation and endovascular treatment for IPA originating from head trauma or iatrogenic injury at a single institution.

RESULTS

Two hundred twenty-one articles in the original literature search. Fifty-one met inclusion criteria resulting in a total of 87 patients with 88 IPAs including our institution. Patients ranged in age from 0.5 months to 18 years. Parent vessel reconstruction was used as first-line treatment in 43 cases, parent vessel occlusion in 26, and direct aneurysm embolization (DAE) in 19. Intraoperative complications were observed in 3.00% of procedures. Complete aneurysm occlusion was achieved in 89.61% of cases. 85.54% of cases resulted in favorable clinical outcomes. The mortality rate after treatment was 3.61%. The DAE group had higher rates of aneurysm recurrence than other treatment strategies (P = 0.009). Patients with SAH had overall worse outcomes compared to patients who did not (P = 0.024). There were no differences in favorable clinical outcomes (P = 0.274) or complete aneurysm occlusion (P = 0.13) between primary treatment strategies.

CONCLUSIONS

IPAs were successfully obliterated, and favorable neurological outcomes were achieved at a high rate regardless of primary treatment strategy. DAE had a higher rate of recurrence than the other treatment groups. Each described treatment method in our review is safe and viable for the treatment of IPAs in pediatric patients.

Endovascular treatment of pediatric basilar artery aneurysms: case series and literature review

PURPOSE

Pediatric basilar artery aneurysms are rare and challenging to treat. Microsurgical options and standard endovascular coiling are often undesirable choices for treatment of this pathology. Additional endovascular strategies are needed.

METHODS

Presentation, diagnosis, and management of pediatric basilar aneurysms were reviewed, with an emphasis on endovascular treatment strategies. Our case series of 2 patients was presented in detail, one treated with flow diversion and vessel sacrifice and one treated with stent-assisted coiling. An extensive review of the literation was performed to find other examples of pediatric basilar artery aneurysms treated with endovascular techniques.

RESULTS

Twenty-nine studies met inclusion criteria. Fifty-nine aneurysms in 58 patients were treated using endovascular techniques. Mortality rate was 10.3% (6/58) and a poor outcome (GOS 1-3) occurred in 15.5% (9/58). There were 4 reported recurrences requiring retreatment; however, only 46.5% of patients had reported follow-up of at least 1 year. 71.1% (42/59) were dissecting aneurysms.

CONCLUSION

Basilar artery aneurysms in the pediatric population are rare, commonly giant and fusiform, and often not amenable to microsurgical or coiling techniques. The surrounding vasculature, location, size, and morphology of the aneurysm along with the durability of treatment must be considered in treatment decisions. With proper patient selection, stent-assisted coiling and flow diversion may increase the durability and safety of endovascular treatment in this population.

Initial experience with Pipeline embolization of intracranial pseudoaneurysms in pediatric patients

OBJECTIVE

Flow-diverting devices have been used successfully for the treatment of complex intracranial vascular injuries in adults, but the role of these devices in treating iatrogenic and traumatic intracranial vascular injuries in children remains unclear. The authors present their experience using the Pipeline embolization device (PED) for treating intracranial pseudoaneurysms in children.

METHODS

This single-center retrospective cohort study included pediatric patients with traumatic and iatrogenic injuries to the intracranial vasculature that were treated with the PED between 2015 and 2021. Demographic data, indications for treatment, the number and sizes of PEDs used, follow-up imaging, and clinical outcomes were analyzed.

RESULTS

Six patients with a median age of 12 years (range 7-16 years) underwent PED placement to treat intracranial pseudoaneurysms. There were 3 patients with hemorrhagic presentation, 2 with ischemia, and 1 in whom a growing pseudoaneurysm was found on angiography. Injured vessels included the anterior cerebral artery (n = 2), the supraclinoid internal carotid artery (ICA, n = 2), the cavernous ICA (n = 1), and the distal cervical ICA (n = 1). All 6 pseudoaneurysms were successfully treated with PED deployment. One patient required re-treatment with a second PED within a week because of concern for a growing pseudoaneurysm. One patient experienced parent vessel occlusion without neurological sequelae.

CONCLUSIONS

Use of the PED is feasible for the management of iatrogenic and traumatic pseudoaneurysms of the intracranial vasculature in children, even in the setting of hemorrhagic presentation.

Pipeline embolization of cerebral aneurysms in pediatric patients: combined systematic review of patient-level data and multicenter retrospective review

OBJECTIVE

Cerebral aneurysms in the pediatric population are rare and optimal treatment strategies are not as well characterized as in adults. The Pipeline embolization device (PED) is an endoluminal flow diverter that is commonly used to treat aneurysms in adults, but experience with this device in children is limited. The authors sought to further characterize PED use and outcomes in this specific population by performing both a systematic review of patient-level data from studies reporting the use of the PED to treat pediatric aneurysms and a retrospective review of their experience.

METHODS

A systematic review of the PubMed, Embase, and Scopus databases was performed to identify studies reporting the use of the PED in pediatric patients (age ≤ 18 years). Disaggregated data regarding demographics, aneurysm characteristics, treatment, and outcomes were collected. Retrospective data from the authors' two institutions were also included.

RESULTS

Thirty studies comprising patient-level data on 43 pediatric patients with 47 aneurysms were identified. An additional 9 patients with 9 aneurysms were included from the authors' institutions for a total of 52 patients with 56 aneurysms. The mean patient age was 11.1 years. Presentations included aneurysm rupture (17.3%) and symptomatic mass effect (23.1%). Aneurysms were located in the anterior circulation in 55.4% of cases, and 73.2% were described as nonsaccular. Imaging follow-up was available for 89.3% with a mean follow-up of 13.3 months. Aneurysm occlusion was reported in 75%, with 1 case each (1.8%) demonstrating significant in-stent stenosis and parent vessel occlusion. Clinical follow-up was reported in 90.4% with a mean follow-up of 14.7 months. Good functional outcomes (modified Rankin Scale score of 0-1 or Glasgow Outcome Scale score of 5) were reported in 65.4% of the total population. Two major complications were reported, including 1 death.

CONCLUSIONS

Despite substantial differences in aneurysm location and type between published pediatric and adult patient populations treated with the PED, the use of the PED in the pediatric population appears to be safe. While the short-term effectiveness is also similar to that of adults, additional studies are needed to further characterize the long-term outcomes and better define the use of this device in pediatric patients.

Analyzing the Safety and Efficacy of Flow-Diverting Stents in Pediatric Aneurysms: A Systematic Review

Ruptured intracranial aneurysms cause 50% of spontaneous subarachnoid hemorrhages in children, resulting in up to 65% mortality when left untreated. Although flow-diverting stents are especially suited to treat the fusiform and giant aneurysms more commonly found in children, the US Food and Drug Administration (FDA) has only approved their use in patients ≥22 years of age. Our objective was to assess the safety of flow-diverting stents in the treatment of pediatric patients with aneurysms through a systematic literature review using the PRISMA criteria. We used PubMed, Embase, and Web of Science to identify all published cases of pediatric aneurysms treated or retreated using flow-diverting stents from 2007 through 2019. Two independent researchers developed a consensus regarding the inclusion of all articles. Patient data were extracted from the identified articles and used to calculate the incidence rate of complications. From 1396 journal articles identified, 24 articles contained data on 37 pediatric patients that met the inclusion criteria. Of these 37 patients, 8 (21.6%) had a complication by last follow-up (death: 2; residual aneurysm: 2; parent artery occlusion: 4). This resulted in an incidence rate of 0.018 complications per patient at-risk month (95% CI 0.008-0.035). These data suggest that the use of flow-diverting stents for treatment of aneurysms in children may be safe and that FDA approval for this use should be evaluated. Although this analysis is comprised of case reports and case series, it represents the best attempt thus far to quantify the risk of using flow-diverting stents in children.

Endovascular stenting for rescue of a failed donor graft during superficial temporal artery to middle cerebral artery bypass surgery: case report

Direct bypass has been used to salvage failed endovascular treatment; however, little is known of the reversed role of endovascular management for failed bypass.The authors report the case of a 7-year-old patient who underwent a superficial temporal artery to middle cerebral artery (STA-MCA) bypass for treatment of a giant MCA aneurysm and describe the role of endovascular rescue in this case. Post-bypass catheter angiogram showed occlusion of the proximal extracranial STA donor with patent anastomosis, possibly due to STA dissection. A self-expanding Neuroform Atlas stent was deployed across the dissection flap, and follow-up images showed revascularization of the STA with good MCA runoff.This case demonstrates that direct extracranial-intracranial bypass failure can infrequently originate from the STA donor vessel and that superselective angiogram can be useful for identification and treatment in such cases. With more advanced endovascular techniques the tide has turned in the treatment of complex cerebrovascular cases, with this case being an early example of successful rescue stenting for endovascular management of a failed donor after STA-MCA bypass.

Flow Diversion for Treatment of Intracranial Aneurysms in Pediatric Patients: Multicenter Case Series

BACKGROUND

Though the Pipeline Embolization Device (Medtronic) is approved for use in adults 22 yr and older, the high efficacy and long-term durability of the device is attractive for treatment of intracranial aneurysms in younger patients who often have aneurysms less amenable to traditional endovascular treatments.

OBJECTIVE

To report technical, angiographic, and clinical outcomes in patients aged 21 or below undergoing flow-diversion treatment for intracranial aneurysms.

METHODS

Retrospective review across 16 institutions identified 39 patients aged 21 or below undergoing 46 treatment sessions with Pipeline Embolization Device placement between 2012 and 2018. A total of 50 intracranial aneurysms were treated. Details regarding patient demographics, aneurysm characteristics, treatment considerations, clinical outcomes, and aneurysm occlusion were obtained and analyzed in a multicenter database.

RESULTS

A total of 70% of patients were male. Nonsaccular morphology was seen in half of identified aneurysms. Six aneurysms were giant, and five patients were treated acutely after ruptured presentation. Eight patients were younger than 10 yr of age. Complete aneurysm occlusion was seen in 74% of treated aneurysms. Three aneurysms (6%) were retreated. A total of 83% of patients had a modified Rankin Scale scores of ≤2 at last clinical follow-up. There were 2 early mortalities (4.3%) in the immediate postprocedure period because of rerupture of a treated ruptured aneurysm. No recanalization of a previously occluded aneurysm was observed.

CONCLUSION

Flow-diversion treatment is a safe and effective treatment for intracranial aneurysms in patients younger than 22 yr. Rates of complete aneurysm occlusion and adverse events are comparable for rates seen in older patients.

Application of the Pipeline Embolization Device for Giant Vertebrobasilar Dissecting Aneurysms in Pediatric Patients

Objective: To evaluate the feasibility and effectiveness of the pipeline embolization device (PED) for the treatment of pediatric giant vertebrobasilar dissecting aneurysms (VBDAs).

Methods: We retrospectively reviewed our institutional clinical database and identified 2,706 patients who presented with a diagnosis of intracranial aneurysms from January 2016 to June 2018. Among this group, 153 patients were diagnosed with VBDAs, and 54 of these patients underwent PED therapy. The PED technique was used in four patients who were 18 years old or younger at the time of presentation (two males, two females; mean age 9.25 years; age range 8–11 years).

Results: All four included pediatric patients were managed with the PED. One patient (25%) was treated with the PED alone, while three (75%) were treated with the PED and coils. One patient died from brainstem infarction or compression of the brainstem, while follow-up of the other three patients revealed favorable outcomes. The mass effect was reduced in cases 1, 2, and 3 on follow-up MRI performed 6 months after the PED procedure.

Conclusions: PEDs could be feasible in the treatment of pediatric giant VBDAs. However, the safety and efficacy of this method have not been clarified in this special pediatric population, and long-term follow-up is still necessary.

Pediatric Intracranial Aneurysms: Favorable Outcomes Despite Rareness and Complexity

OBJECTIVE

Pediatric intracranial aneurysms (IAs) are rare and differ from their adult counterparts in terms of their aneurysmal characteristics, presentation, treatment, and outcomes. Their treatment is often more difficult and complex compared with that of adults. However, studies outlining the clinical effect of pediatric IAs remain sparse.

METHODS

We retrospectively reviewed the data from patients aged ≤18 years admitted to our hospital from 2000 to 2017 with a diagnosis of IAs.

RESULTS

From the sample of 8207 patients with an IA diagnosis, 26 patients with 33 IAs were involved. Our cohort included 17 males and 9 females, with a mean age of 12.5 years. The mean follow-up duration was 4 years and 3 months. Seven patients (26.92%) were assumed to have a traumatic origin for their IAs. Ruptured aneurysms were more common than unruptured ones (61.53% vs. 38.46%). Complex features were observed in 14 aneurysms (42.42%). Initially, microsurgical and endovascular treatment were both performed in 10 patients (38.46%). A good recovery was obtained in 16 patients (61.54%) as determined by the Glasgow outcome scale scores at the 6-month follow-up visits. The complete obliteration of aneurysms was observed in 17 patients (65.38%). Endovascular treatment was the initial treatment in 3 patients with incomplete obliteration.

CONCLUSIONS

The treatment of pediatric IAs is challenging and technically demanding owing to their discrete nature compared with adult IAs and the need for greater surgical skills. We found a male predominance, with internal carotid artery bifurcation as the most frequent location of the aneurysms. Despite the greater incidence of ruptured and complex aneurysm cases, many patients had experienced a good recovery at the 6-month follow-up examinations.

Pipeline Embolization of an Infectious Basilar Artery Aneurysm in a 2-Year-Old Child: Case Report, Discussion of the Literature and Perioperative Considerations

BACKGROUND AND IMPORTANCE

Flow diversion of intracranial aneurysms has been rarely described in the pediatric population. Here we discuss the technical and perioperative complexities inherent in the flow diversion of an infectious basilar apex aneurysm in a 2-yr-old child with significant medical comorbidities.

CLINICAL PRESENTATION

Following judicious oral administration of dual anti-platelet agents and intra-arterial administration of calcium channel blockers to treat vasospasm, standard endovascular procedures were used to place a flow diverting stent across the neck of a rapidly enlarging infectious aneurysm of the basilar apex.

Following the uncomplicated procedure, the patient demonstrated progressive thrombosis of the previously noted basilar apex aneurysm over a 3-mo period. The patient was therefore felt to be safe to proceed with, and eventually underwent, uncomplicated orthotopic heart transplant.

CONCLUSION

Flow diversion of complex intracranial aneurysms in pediatric patients with significant medical comorbidities is feasible and safe; however, considerations have to be made in the pre- and perioperative care of these patients given the propensity for low-weight and complicated systemic disease processes.

Pipeline-assisted coil embolization of a large middle cerebral artery pseudoaneurysm in a 9-month-old infant: experience from the youngest flow diversion case

Intracranial aneurysms in the pediatric population are rare entities. The authors recently treated a 9-month-old infant with a 19-mm recurrent, previously ruptured, and coil-embolized left middle cerebral artery (MCA) pseudoaneurysm, which was treated definitively with single-stage Pipeline-assisted coil embolization. The patient was 5 months old when she underwent resection of a left temporal Grade 1 desmoplastic infantile ganglioglioma at an outside institution, which was complicated by left MCA injury with a resultant 9-mm left M1 pseudoaneurysm. Within a month, the patient had two aneurysmal rupture events and underwent emergency craniectomy for decompression and evacuation of subdural hematoma. The pseudoaneurysm initially underwent coil embolization; however, follow-up MR angiography (MRA) revealed aneurysm recanalization with saccular enlargement to 19 mm. The patient underwent successful flow diversion-assisted coil embolization at 9 months of age. At 7 months after the procedure, follow-up MRA showed complete aneurysm occlusion without evidence of in-stent thrombosis or stenosis. Experience with flow diverters in the pediatric population is still in its early phases, with the youngest reported patient being 22 months old. In this paper the authors report the first case of such a technique in an infant, whom they believe to be the youngest patient to undergo cerebral flow diversion treatment.

Hybrid vascular intervention for a giant cervical carotid artery aneurysm in a clopidogrel-hyporesponsive child

Aneurysms of the extracranial internal carotid artery (ICA) in pediatric patients are rare and mostly treated surgically. The authors present the case of a child with a giant extracranial ICA aneurysm presenting with gradual airway compression. A plan was made to explore the aneurysm surgically and straighten the associated carotid artery kinks during the operation to enable further endovascular treatment if primary reconstruction of the carotid artery proved not to be possible. Finally, the aneurysm was successfully treated with staged hybrid intervention, which consisted of surgical correction of parent artery kinks followed by endovascular implantation of stent grafts. The child tolerated the procedure well without adverse events. A craniocervical CT angiogram at 5 months showed patency of the stent construct and relief of airway compression. However, a follow-up CT angiogram at 14 months showed total occlusion of the ipsilateral carotid artery without clinical sequelae and complete cessation of airway compression. The management of this was unique since the patient is the first reported case of clopidogrel hyporesponsiveness in a child undergoing neurovascular intervention with prasugrel monotherapy. Point-of-care testing-based adjustment of prasugrel necessitated education of the patient's family regarding the loss of effect of the prasugrel tablets upon crushing and contact with air.