Late morphological progression of a dissecting basilar artery aneurysm after staged bilateral vertebral artery occlusion: case report

Petrous Carotid to Upper Posterior Circulation Bypass for the Treatment of Basilar Trunk Aneurysm: A Novel High-Flow Intracranial-Intracranial Skull Base Bypass for Posterior Circulation

BACKGROUND

Basilar trunk aneurysms are the most surgically challenging, and the spectrum covers small fusiform to dolichoectatic aneurysms and may lead to rupture, brain ischemia, or direct brainstem compression. The current strategy remains cerebral revascularization coupled with aneurysm trapping. Available bypass options for upper posterior circulation (UPC) are based on (1) different flow volumes from diverse blood supplies and (2) distinct modulation purposes for cerebral revascularization; however, the potential compromise of eloquent perforators of the basilar trunk and the occurrence of fatal brainstem infarcts remain unacceptable.

OBJECTIVE

To innovate a high-flow intracranial-intracranial skull base bypass for posterior circulation to afford robust retrograde flow and shorten the graft length.

METHODS

We retrospectively reviewed our experience in the treatment of a patient with basilar trunk aneurysm and reported a novel bypass alternative supplied by petrous internal carotid artery to augment blood flow to the UPC by a pretemporal approach.

RESULTS

The postoperative course was uneventful, and there was no pons or midbrain ischemia or other complications. Postoperative computed tomography angiogram revealed the patency of bypass. There was no further development or rerupture observed during follow-up.

CONCLUSION

Petrous internal carotid artery as a donor site is a reliable bypass modality for UPC. This approach provides the utmost retrograde flow to alleviate the development of dissecting aneurysms, preserves eloquent perforators of the basilar trunk, maintains bypass patency, and shortens the graft course. Therefore, this novel therapeutic alternative could be beneficial for improving the prognosis of basilar trunk aneurysms.

Blebs in intracranial aneurysms: prevalence and general characteristics

BACKGROUND

Blebs are rupture risk factors in intracranial aneurysms (IAs), but their prevalence, distribution, and associations with clinical factors as well as their causes and effects on aneurysm vulnerability remain unclear.

METHODS

A total of 122 blebs in 270 IAs selected for surgery were studied using patient-specific vascular reconstructions from 3D angiographic images. Bleb geometry, location on the aneurysm, and frequency of occurrence in aneurysms at different locations were analyzed. Associations between gender, age, smoking, hypertension, hormone therapy, dental infection, and presence of blebs were investigated.

RESULTS

Of all aneurysms with blebs, 77% had a single bleb and 23% had multiple blebs. Only 6% of blebs were at the neck, while 46% were in the body and 48% in the dome. Aneurysms with blebs were larger (p<0.0001), more elongated (p=0.0002), and with wider necks than aneurysms without blebs. Bleb presence was associated with dental infection (p=0.0426) and negatively associated with hormone therapy (p=0.0426) in women. Anterior and posterior communicating arteries had larger percentages of aneurysms with blebs than internal carotid arteries. Patients with a history of hypertension tended to have a larger percentage of aneurysms with blebs. However, these trends did not reach significance in this sample.

CONCLUSIONS

Blebs are common in IAs, and most aneurysms harboring blebs have a single bleb. Blebs in the aneurysm neck are rare, but they are equally common in the body and dome. The presence of blebs in IAs was associated with dental infection, and negatively associated with hormone replacement therapy.

Treatment Strategies of Subarachnoid Hemorrhage from Bilateral Vertebral Artery Dissection: A Case Report and Literature Review Focusing on the Availability of Stent Placement

BACKGROUND

Bilateral vertebral artery dissection (VAD) may result in subarachnoid hemorrhage (SAH). However, a variety of factors contribute to the difficulties with treating SAH. We report a case of bilateral VAD with SAH, as well as a literature review.

CASE DESCRIPTION

A 32-year-old woman developed headache. Computed tomography demonstrated diffuse SAH, and 3-dimensional computed tomography indicated bilateral VAD. Her left vertebral artery was severely stenosed, and the basilar artery retrogradely flowed via the posterior communicating artery. Her bilateral VAD was trapped with the use of staged craniotomy. The postoperative course was uneventful for 13 days; however, severe neurologic deterioration remained in the area of the cerebral infarction, due to vasospasm of the internal carotid artery. This is the first report of hemorrhagic bilateral VAD treated with bilateral trapping and aggressive spasm treatment in the acute phase. However, the treatment was not successful.

CONCLUSIONS

Because of the increasing use of stent therapy, there has been a shift toward this treatment choice. For cases in which stents cannot be used, treatment methods based on prestenting protocols are helpful. A literature review indicated that conservative treatment for 2 weeks, in which vasospasm and rebleeding are controlled, may be considered compared with acute-stage stent treatment. Following our literature review, in situations in which stents cannot be used, only the ruptured side should be trapped with strict blood pressure control and detailed radiological images should be observed for 2 weeks. In conclusion, patient selection is essential to subject the patient to open surgery in such cases.

The Medina Embolic Device: early clinical experience from a single center

Objective

To report our initial experience with the Medina Embolic Device (MED) in unruptured intracranial aneurysms either as sole treatment or in conjunction with additional devices.

Methods

15 consecutive patients (6 women, 9 men) with unruptured aneurysms were treated between September 2015 and April 2016. The aneurysm fundus measured at least 5 mm. We evaluated the angiographic appearances of treated aneurysms at the end of the procedure and at follow-up, the clinical status, complications, and requirement for adjunctive devices.

Results

The MED was successfully deployed in all but one case and adjunctive devices were required in 10 cases. Aneurysm locations were middle cerebral artery bifurcation (n=3), internal carotid artery (ICA) bifurcation (n=1), supraclinoid ICA (n=5), posterior communicating artery (n=1), anterior communicating artery (n=2), cavernous ICA (n=2), distal basilar sidewall (n=1), basilar tip (n=1). Three patients had complications although none could be attributed to the MED. Immediate angiographic results were modified Raymond-Roy classification (mRRC) I=1, mRRC II=5, mRRC IIIa=3, mRRC IIIb=5, and one patient showed contrast stasis within the fundus of the aneurysm. Follow-up angiography was available in 11 patients, with four showing complete aneurysm exclusion, six with stable remnants and one patient with an enlarging neck remnant.

Conclusions

The MED represents a major step forward in the treatment of intracranial aneurysms. It can result in rapid exclusion of an aneurysm from the circulation and has a good safety profile. We believe that the true value of the MED will be in combining its use with adjunctive devices such as endoluminal flow diverters that will result in rapid aneurysmal exclusion.

Basilar Artery Dissection Presenting with Subarachnoid Hemorrhage: Report of Two Cases

Basilar artery dissection (BAD) presenting with subarachnoid hemorrhage (SAH) is life-threatening, but its treatment has not been established yet. We treated two patients with ruptured BAD. They were 40-year-old and 41-year-old women. Both of them were treated conservatively during the acute stage. In one patient, radiological abnormality of BAD improved spontaneously. In another patient, reconstructive endovascular treatment (stent with coiling) was required in the chronic stage because the lesion deteriorated morphologically. Neither of them suffered from rebleeding and both had favorable outcome. We reported two patients with ruptured BAD treated conservatively during the acute stage and their outcomes were favorable. We reviewed the literature of BAD presenting with SAH and discussed the management for these lesions.

Overview of spontaneous cervicocephalic arterial dissection in Japan

Spontaneous cervicocephalic arterial dissection (SCAD) has been recognized as an uncommon cause of cerebral stroke. Although it has been viewed as an important cause of stroke, especially in juvenile cases, its natural course and pathophysiology have yet to be fully clarified, and no treatment criteria have been established. Recent studies have suggested that clinical features of SCAD in Japan are different from those in European countries. Herein, we reviewed the current status of the management of SCAD in Japan, and clarified its clinical characteristics to establish an appropriate treatment.

Hemodynamics and bleb formation in intracranial aneurysms

BACKGROUND AND PURPOSE

Intracranial aneurysms with irregular shapes and blebs or secondary outpouchings have been correlated with increased rupture risk. The purpose of this study was to investigate possible associations between the local hemodynamics and the formation of blebs in cerebral aneurysms.

MATERIALS AND METHODS

Computational models of 20 cerebral aneurysms harboring 30 well-defined blebs were constructed from 3D rotational angiographies. Models representing the aneurysm before bleb formation were constructed by virtually removing the blebs from the anatomic models. Computational fluid dynamics simulations of the aneurysm before and after bleb formation were performed under pulsatile flows. Flow and WSS visualizations were used to analyze the local hemodynamics in the region of the aneurysm that developed the bleb.

RESULTS

Most blebs (80%) occurred at or adjacent to the aneurysm region with the highest WSS before bleb formation, and near the flow impaction zone. Most blebs (83%) were found in regions of the aneurysm previously subjected to high or moderate WSS and progressed to low WSS states after the blebs were formed. Most blebs (77%) were aligned or adjacent to the inflow jet, whereas 17% were aligned with the outflow jet, and only 6% were not aligned with the flow direction. In addition, 90% of the aneurysms had maximal WSS higher than or similar to the WSS in the parent artery.

CONCLUSIONS

Blebs form at or adjacent to regions of high WSS and are aligned with major intra-aneurysmal flow structures. Formation of blebs results in a lower WSS state with formation of a counter current vortex. These findings imply that locally elevated WSS could contribute to the focalized wall damage that formed these structures.

Use of the sole stenting technique for the management of aneurysms in the posterior circulation in a prospective series of 20 patients

Object

The use of intracranial stents in stent-assisted coil embolization is now a current neurosurgical practice worldwide. The clinical utility of these stents in the sole stenting (SS) technique, however, has not been thoroughly described, and the published reports of this experience are scarce. This study was designed to evaluate SS treatment of dissecting and nondissecting aneurysms of the posterior circulation.

Methods

This prospective and descriptive study was conducted in 20 consecutive patients who harbored single aneurysms of the posterior circulation and who were treated using the SS approach in the last 3 years. The clinical and radiological assessment and follow-up of the patients were evaluated using the modified Rankin scale as well as with computed tomography angiography and digital subtraction angiography at discharge and at 1, 3, 6, and 12 months.

Results

Eleven of the 20 patients had subarachnoid hemorrhages, 3 presented with ischemia, 1 presented with brainstem compression, and the remaining 5 patients had incidentally discovered, asymptomatic lesions. Only 1 patient had a complication (occipital infarction) attributable to the SS procedure. One patient died of rebleeding 2 weeks after the procedure. At 1 month, 40% of the patients had a subtotal or total occlusion, which increased to 55% at 3 months and 85% at 6 months, with a final subtotal or total occlusion rate of 80% at 1 year. The SS procedure in 1 case was considered a failure at 6 months because no change had been noted since the 1-month follow-up. One case showed partial occlusion and 1 case showed recanalization.

Conclusions

Use of SS for aneurysms in the posterior circulation complex is a safe and effective technique, demonstrating an occlusion rate of 80% at the 1-year follow up.

Endovascular treatment of huge dissecting aneurysms involving the basilar artery. Experience and lessons from two cases

SUMMARY

Dissecting aneurysms involving the basilar artery (BA) are lesions with significant morbidity and mortality. Their management is controversial and often difficult. There is no generally approved strategy. Two cases of huge dissections involving the BA presented with subarachnoid hemorrhage in one case and mass effect in both cases. The dissection of case 1 involved the upper two thirds of the BA distal to the anterior inferior cerebellar arteries (AICA). Another dissection of case 2 involved the bilateral vertebral arteries (VA) distal to bilateral PICA and extended to upper third of the BA. After making a basket with coils inside the pseudoaneursym, proximal dissection was totally occluded in case 1. Dissection on the bilateral VA distal to the bilateral PICA and proximal BA was occluded in case 2 with a small residual dissection on the left VA. Case 1 had an excellent recovery with a durable image and clinical result. But recanalization and regrowth occurred in case 2, which might have originated from the residual dissection on the left VA, induced acute mass effect and sudden coma six weeks after the initial treatment. The residual and regrown dissection had to be occluded in a second intervention. The patient died two days later. BA occlusion is safe and efficient for dissections involving the BA as in our case and the literature. Proximal occlusion might be enough for huge and long lesions like ours. It seems that completely dense packing of proximal dissection is the key point to prevent recanalization.