Healing process for cerebral dissecting aneurysms presenting with subarachnoid hemorrhage

Two Cases of Subarachnoid Hemorrhage with Microaneurysmal Changes and Spontaneous Disappearance in the Basilar Artery

A 79-year-old woman presented at our hospital with sudden headache and vomiting. Computed tomography revealed diffuse subarachnoid hemorrhage. Although digital subtraction angiography (DSA) performed on admission and on the following day revealed no vascular abnormalities, DSA on Day 22 revealed microaneurysmal changes in the dorsal basilar artery. However, the aneurysmal changes gradually became smaller during follow-up, and DSA on Day 73 revealed complete disappearance. A 53-year-old man also presented to our hospital with sudden headache and vomiting. Computed tomography revealed perimesencephalic subarachnoid hemorrhage. DSA on Days 9 and 16 revealed microaneurysmal changes in the dorsal basilar artery. Conservative treatment was continued, and DSA on Day 42 revealed spontaneous disappearance of the lesion. It has been reported that basilar artery perforating aneurysms cause angiogram-negative subarachnoid hemorrhage, which disappears spontaneously. The fact that lesions previously reported as basilar artery perforating aneurysms may include cases of acute dissection of the main trunk or perforating branches of the basilar artery implies that surgical or endovascular treatment may worsen the condition. Therefore, conservative treatment may be an important option.

Comparing the safety and effectiveness of overlapping stents with flow diverters for unruptured vertebral artery dissecting aneurysms

BACKGROUND

Endovascular treatment for vertebral artery dissecting aneurysms (VADAs) includes overlapping stents and flow diverters. This study compared the safety and effectiveness of overlapping stents and flow diverters for unruptured VADAs.

METHODS

We retrospectively enrolled patients with unruptured VADAs who underwent overlapping stents or flow diverters at two tertiary hospitals in South Korea. The primary clinical outcome was the occurrence of stroke. The primary angiographic outcomes (>12 months) were categorized as regression, no decrease in size, recanalization, or stent occlusion, of which only regression was defined as a favorable angiographic outcomes.

RESULTS

Of the 146 patients with VADAs, 25 (17.1%) had flow diverters and 121 (82.9%) had overlapping stents. For the primary angiographic outcomes over 12 months, the rate of favorable angiographic outcomes for flow diverters was 81.8% and for overlapping stents (triple stents) was 98.8% (P=0.006). In the multivariale analysis, after adjusting for partially thrombosed aneurysms, aneurysm shape, non-dominant vessel, posterior inferior cerebellar artery involvement, and procedure type, overlapping stents (triple stents) was not associated with favorable angiographic outcomes compared with flow diverters (OR 7.040, 95% CI 0.549 to 90.294; P=0.134), but partially thrombosed aneurysms was inversely associated with favorable angiographic outcomes (OR 0.056, 95% CI 0.005 to 0.589; P=0.016). The primary clinical outcome followed up to the last angiography did not occur in all patients.

CONCLUSION

There was no difference in safety and effectiveness between overlapping stents and flow diverters in unruptured VADAs. Further endovascular treatment studies are needed regarding the association of partially thrombosed aneurysms with unfavorable angiographic outcomes.

Intimal Hemorrhage of Basilar Artery Induced by Severe Vasospasm Following Subarachnoid Hemorrhage: The Experimental Analysis

BACKGROUND

 Cerebral vasospasm, a serious complication of subarachnoid hemorrhage (SAH), has been extensively studied for its neurochemical and pathophysiologic mechanisms. However, the contribution of inner elastic membrane dissection and subintimal hemorrhage to basilar artery occlusion remains underexplored. This study investigates inner elastic membrane-related changes in the basilar artery after SAH.

METHODS

 Twenty-four hybrid rabbits were divided into control, sham, and SAH groups, with SAH induced by autologous blood injection. After 2 weeks, basilar artery changes, vasospasm indexes (VSIs), and dissections were evaluated.

RESULTS

 The SAH group showed significantly higher VSI, with vascular wall thickening, luminal narrowing, convoluted smooth muscle cells, intimal elastic membrane disruption, endothelial cell desquamation, and apoptosis. Some SAH animals exhibited subintimal hemorrhage, inner elastic membrane dissection, and ruptures. Basilar arteries with subintimal hemorrhage had notably higher VSI.

CONCLUSIONS

 These findings highlight the role of subintimal hemorrhage and inner elastic membrane dissection in basilar artery occlusion post-SAH, offering valuable insights into vasospasm pathophysiology.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review

Fusiform aneurysms of the anterior cerebral artery (ACA) are uncommon, and the natural history of this entity is poorly characterized. Along with our center experience, we conducted a systematic literature review to help shed light on the clinical course of ACA fusiform aneurysms. We queried our institutional database to identify cases with fusiform aneurysms of ACA. In addition, following the PRISMA algorithm, we identified all reported cases published in the English literature from the inception of PubMed until December 2022. We categorized clinical presentations into three categories: (i) traumatic/iatrogenic, (ii) spontaneous symptomatic ruptured/unruptured, and (iii) spontaneous asymptomatic aneurysms. We utilized descriptive statistics. We identified seven cases from our center along with 235 patients from published literature. Blunt trauma was responsible for the development of 19 aneurysms. Sixty-three percent of these aneurysms tend to rupture within 2 weeks from the initial trauma, and despite treatment, only 74% of these patients had good clinical outcomes. Spontaneous symptomatic presentation occurred in 207 patients and was often associated with previous/concomitant ACA dissection. Subarachnoid hemorrhage from ruptured aneurysms was the most common presentation. Spontaneous symptomatic fusiform aneurysm is rapidly evolving lesions, and treatment is necessary. Three of our own cases were treated with an endovascular flow diverter (pipeline) stenting with good outcomes. Spontaneous asymptomatic aneurysms were reported in nine patients. These lesions are often associated with other vascular abnormalities. Treatment included surgical clipping with good clinical outcomes. Instead, four patients from our center database were managed conservatively with equally good outcomes. Our study demonstrates good clinical outcomes when fusiform aneurysms of ACA, especially when symptomatic, are treated promptly with either reconstructive or deconstructive therapies.

Trapping and side-to-end superior cerebellar artery to superior cerebellar artery bypass for treatment of fusiform superior cerebellar artery aneurysm

We describe the technical nuances of in-situ bypass for treatment of a fusiform superior cerebellar artery (SCA) aneurysm via surgical trapping and a side-to-end in-situ bypass between duplicated SCAs. Our patient is a 40-year-old male who presented with an incidental aneurysm of the proximal right superior cerebellar artery (SCA). Formal angiography was performed that demonstrated a fusiform morphology of the aneurysm, as well as a duplicated SCA on that side. After extensive counseling, the patient elected to undergo surgical clip reconstruction with possible bypass. A large frontotemporal craniotomy was performed and a combined transsylvian-subtemporal approach to the ventral anterolateral brainstem was performed. After identifying the aneurysm, the tentorium was incised posterior to the insertion of the trochlear nerve to widen the operative field. An end-to-side anastomosis between the duplicated SCAs was performed, followed by trapping of the diseased arterial segment. The patient had an oculomotor nerve palsy post-operatively, however this resolved by his six-month follow-up. In-situ bypass is a viable technique for revascularizing the SCA territory during clip reconstruction of fusiform aneurysms. A duplicated SCA allows for an SCA to SCA bypass. Incising the tentorium can increase visualization of donor and recipient vessels and facilitate performance of the anastomosis.

A Ruptured Aneurysm in Aplastic or Twig-like Middle Cerebral Artery: A Case Report with Histological Investigation

Aplastic or twig-like middle cerebral artery (Ap/T-MCA) is a rare vascular anomaly that can cause a hemorrhagic or ischemic event. We report a 38-year-old man who presented with intracerebral hemorrhage from a ruptured aneurysm associated with an Ap/T-MCA. After aneurysm trapping and resection, histopathological examination revealed an internal elastic lamina (IEL) disruption and a thin aneurysmal wall. The patient recovered well after surgery and rehabilitation. No hemorrhagic or ischemic events have occurred during 2 years of follow-up. Ap/T-MCA-associated aneurysms exhibit a disrupted IEL and thin wall, which demonstrates the fragility of the “twig-like” vessels.

Acute hemicranial pain accompanied with a pearl and string type dissection of intracranial vertebral artery: Consideration for the time when to finish the medical observation

The International Classification of Headache Disorder (ICHD) clearly guides the suspicion of intracranial vertebral artery dissection (ICVAD) in headache patients, but guidelines on how observational or imaging studies should be performed to detect dangerous progression early are unclear. Fifty-six cases with pearl and string type intracranial vertebral artery dissection were divided into 3 groups: 39 in the headache group, 6 in the infarction group, and 11 in the hemorrhagic group. Clinical and angiographic data were analyzed and compared. Most headaches resolved within 2 weeks and did not exceed 8 weeks. Of the 33 patients (84.6%) who underwent continuous follow-up imaging, 18 (54.5%) returned to normal, but 3 (9%) had deteriorated. All the patients survived without subsequent bleeding or infarction. Image changes started before 3rd month and ended after 6 to 7 months. In acute ICVADs, image changes occur at the same time as the headache resolves and continue for several months after the headache has subsided. Since the dissection is likely to worsen even after the headache disappears, the image changes continue over several months, and prediction of rupture of unruptured ICVAD is unpredictable, it is desirable to conduct continuous imaging studies regularly after the initiation of dissection until stabilization is confirmed.

Diagnostic accuracy of MR vessel wall imaging at 2 weeks to predict morphological healing of vertebral artery dissection

OBJECTIVES

The spontaneous healing of non-hemorrhagic intracranial vertebral artery dissection (VAD) may be associated with the stabilization of intramural hematoma (IMH). We previously suggested that the signal intensity of IMH increases until approximately 2 weeks in VAD with spontaneous healing. We herein investigated the diagnostic accuracy of the signal intensity of IMH at 2 weeks to predict the spontaneous healing of VAD.

METHODS

From April 2017 to April 2021, we prospectively investigated patients with non-hemorrhagic VAD who underwent vessel wall imaging (VWI). Morphological healing of VAD was evaluated by MR angiography three months after its onset. The relative signal intensity (RSI) of IMH against the posterior cervical muscle on VWI was calculated. Univariate and multivariate analyses were performed on factors associated with the spontaneous healing of VAD among patient baseline data, vascular morphology at the diagnosis, and RSI parameters.

RESULTS

Forty-eight patients (23 men and 25 women; mean age: 51 years, range: 34-73 years) with 50 non-hemorrhagic VAD were included in the present study. Spontaneous healing was observed in 28 VAD (56%). RSI two weeks after the onset of VAD (RSI_2w) and morphological feature such as the string sign were associated with spontaneous healing, respectively. The multivariate logistic regression analysis identified RSI_2w as an independent predictive factor of spontaneous healing (OR: 7.3; 95% CI, 1.9-28, p = 0.004). The cut-off value for RSI_2w to predict spontaneous healing was 1.22 (AUC = 0.90, sensitivity: 91%, specificity: 82%).

CONCLUSION

RSI_2w predicted the spontaneous healing of non-hemorrhagic VAD 3 months after its onset.

Isolated ruptured dissecting aneurysm of PICA with extremely narrow neck managed by a novel endovascular technique-a case report and review of literature

Dissecting aneurysms of posterior inferior cerebellar artery (PICA) are usually extensions of vertebral artery dissection. Isolated dissecting aneurysms of PICA are extremely rare. A 5-month-old female child presented with history of fall from a height of around 2 ft., followed by incessant crying and multiple episodes of vomiting. The anterior fontanelle was lax. Plain CT scan brain showed IVH in the fourth ventricle with no hydrocephalus. Twenty-four hours after admission, the child had one episode of vomiting and became unresponsive. The child was intubated, and a repeat CT scan brain showed thick acute SDH in the posterior fossa with hydrocephalus. Emergency suboccipital craniectomy and evacuation of thick acute subdural hematoma were done. Organized clot noted in the midline between the tonsils was not removed. Digital subtraction angiography (DSA) done 48 h after surgery showed ruptured dissecting aneurysm of left PICA. Endovascular temporary parent artery occlusion by coil deployment was performed, after which a check angiogram revealed complete exclusion of aneurysm from circulation. Endovascular proximal parent artery occlusion is the preferred treatment modality for dissecting aneurysms of PICA. Selective coil or Onyx embolization of the aneurysm with parent vessel preservation technique is a valid and increasingly used alternative. In this case, a novel technique of endovascular temporary parent artery occlusion by coil deployment was performed successfully. This technique may be recommended in select cases.

Characteristics and Management of Ruptured Aneurysms Originating from the Penetrating Artery of the Distal Middle Cerebral Artery

We report a rare case of an aneurysm originating from the penetrating artery of the distal middle cerebral artery (MCA). A 76-year-old man without a notable past history presented with sudden-onset severe headache, left hemiparesis, and a decreased level of consciousness. Computed tomography (CT) revealed subarachnoid hemorrhage (SAH) with intracerebral hemorrhage (ICH) in the right temporal lobe extending into the ventricle. Contrast-enhanced CT (CE-CT) demonstrated a focus of contrast enhancement (CE) adjacent to the hematoma in the right frontal lobe. An aneurysm fed by a penetrating artery branching off from the right distal MCA was found on angiography. The patient underwent emergency resection of the aneurysm and hematoma evacuation. Histological analysis revealed that arterial dissection may be an associated factor in the pathogenesis of this peripheral aneurysm formation. A focus of CE within or adjacent to the hematoma may be useful for diagnosing this peripheral aneurysm. ICH can result in a life-threatening situation. Therefore, microsurgery may be the first treatment choice for aneurysms in this location.

Treatment of pediatric intracranial dissecting aneurysm with clipping and angioplasty, and next-generation sequencing analysis: A case report and literature review

BACKGROUND

Large intracranial dissecting aneurysm (IDA) in the anterior cerebral circulation is rare in children. There has been no consensus on the diagnosis and treatment for IDA in children.

CASE SUMMARY

We report a 3-year-old boy with a large ruptured IDA in the right middle cerebral artery (16 mm × 14 mm). The IDA was successfully managed with clipping and angioplasty. Next-generation sequencing of the blood sample followed by bioinformatics analysis suggested that the rs78977446 variant of the ADAMTS13 gene is a risk for pediatric IDA. Three years after surgery, the boy was develop-mentally normal.

CONCLUSION

Clipping and angioplasty are effective treatments for ruptured IDA in the anterior cerebral circulation. ADAMTS13 rs78977446 is a risk factor for pediatric IDA.

Target Embolization of Dilated Post-PICA Segment for Ruptured PICA-Involved Type Vertebral Artery Dissecting Aneurysm

Objective

In parent artery occlusion (PAO) for ruptured vertebral artery dissecting aneurysms (RVADA), target embolization using coils in a short segment to occlude only the vasodilated area containing the rupture point is selected as a first-choice procedure at our institute. We focused on RVADA involving the posterior inferior cerebellar artery (PICA) and evaluated the treatment results.

Methods

This study consisted of eight cases with RVADA involving the PICA which were treated between October 2007 and January 2020. Based on radiological findings such as the bleb, the rupture points were located at the affected vertebral artery (VA) distal to PICA in all cases. Target embolization, by which only coiling at the dilated segment distal to the VA was performed. We aimed to preserve blood flow to the PICA. The incidence and extent of medullary infarctions, and neurological outcome were retrospectively assessed.

Results

Regarding the diameter of bilateral VA, there were no differences in six cases while the affected VA with RVADA were larger in the remaining two cases. PICA was preserved in all cases but one in which occlusion of complementary PICA was observed. Postoperative medullary infarction was not noted. There was no rebleeding during the follow-up period. However, recanalization of the VA was observed in four cases and additional coil embolization was performed. All patients were discharged with a good outcome (modified Rankin Scale [mRS] 0; seven patients, mRS 2; one patient).

Conclusion

Target embolization preserving the PICA in PICA-involved type RVADA was considered to be an effective treatment method for cases whose rupture point was located in the VA distal to PICA orifice.

Endovascular Treatment of Intracranial Vertebral Artery Dissection

Intracranial vertebral artery dissection (VAD) is the most common arterial dissection in intracranial arteries. Some types of VAD can heal spontaneously after reconstitution of the vessel lumen with excellent prognosis, whereas others can progress to stroke that needs treatment. Recently, endovascular treatment (EVT) has emerged and is suggested as a treatment option for VADs due to perceived low rates of procedure-related morbidity with good efficacy. In the last decade, we have accumulated our strategies to treat those VADs. Here, we try to share our experiences about VADs, including indications and methods of treatment of VADs using EVT. We perform EVT for ruptured VADs presenting with SAH and some of unruptured VADs such as VAD with recurrent or progressive ischemia, dissecting aneurysm larger than 7 mm or with mass effect, early ugly change of VADs in shape and size during follow-up period, involving the basilar artery (BA) and bilateral VADs. We present how we have done in our real practice for the last decade for treating VADs by EVT rather than reviewing and organizing so-far-published literature. We tended to occlude the rupture point by vertebral artery (VA) occlusion in non-dominant VA or stent-assisted coiling in dominant VA for ruptured VADs. We tended to reconstruct original hemodynamics using various stents for unruptured VADs. To decide what to treat and how to treat are very complicated for VADs. However, we believe that EVT is the current mainstay for treating VADs. Each technique of EVT should be determined on a case-by-case basis at the discretion of endovascular neurosurgeons and/or interventional neuroradiologists according to presenting symptoms, hemodynamic status, including sufficiency of the collateral supply and anatomic features of the vertebrobasilar artery as well as the posterior inferior cerebellar artery, anterior spinal artery, and medullary perforators.

Superficial temporal artery-superior cerebellar artery bypass and proximal occlusion through anterior petrosal approach for subarachnoid hemorrhage due to basilar artery dissection

Background:

Subarachnoid hemorrhage (SAH) due to rupture of basilar artery dissection (BAD) is extremely rare and often has a poor prognosis. Since ruptured BAD has high rate of rebleeding and mortality, treatment to prevent rerupture is mandatory in the acute phase. However, to date, no optimal treatment has been established which satisfies secure prevention of rerupture and ischemia simultaneously. Herein, we report a case of SAH due to BAD treated with proximal occlusion of basilar artery with superficial temporal artery (STA)-superior cerebellar artery (SCA) bypass, preventing rebleeding securely and ensuring adequate blood flow in the upper basilar region.

Case Description:

A 48-year-old male presenting with headache and altered mental status was found to have SAH and BAD. To prevent rerupture, proximal occlusion of basilar artery with STA-SCA bypass using anterior transpetrosal approach was performed. The postoperative course was relatively good and there is no evidence of recurrent arterial dissection.

Conclusion:

Proximal occlusion of the basilar artery combined with STA-SCA bypass was successful in preventing rerupture of BAD and ensuring blood flow in the upper basilar region. Although there is controversy regarding acute treatment for ruptured BAD, direct proximal occlusion with sufficient revascularization using bypass skull base technique may be one of the optimal treatments even in this era of endovascular treatment.

Differentiating between Mycotic and Dissecting Aneurysms in a Case of Ruptured Distal Superior Cerebral Artery Aneurysm

Objective

We present a case of subarachnoid hemorrhage (SAH) due to ruptured mycotic aneurysm found in the distal superior cerebellar artery (SCA).

Case Presentation

A 64-year-old man was admitted to our hospital with sudden unconsciousness. He had a history of alcoholism but no family history of SAH. Computed tomography (CT) showed apparent SAH; however, CT angiography (CTA) showed no apparent cause of SAH except for two small aneurysms in the same branch of the left distal SCA. We suspected mycotic aneurysm and prescribed antibiotics. It was difficult to diagnose the condition as mycotic aneurysm because there were no vegetations or caries at the time of admission. Because there were two aneurysms in the same branch with partial dilatation and stenosis, we suspected dissecting aneurysm, but continued to administer antibiotics for possible mycotic aneurysm. After the first operation, we diagnosed mycotic aneurysm because a vegetation and valve degeneration was found.

Conclusion

It is difficult to distinguish mycotic aneurysms from dissecting aneurysms because of similar appearance on imaging, especially if no vegetation is found. Nevertheless, it is important to start treatment for mycotic aneurysm. If there is the possibility of mycotic aneurysm, appropriate antibiotics should be administered, and endovascular treatment could be considered for patients with deteriorating conditions.

A case of unilateral vertebral artery dissection progressing in a short time period to bilateral vertebral artery dissection

Background

Vertebral artery dissection (VAD) is an important cause of stroke in young and middle- aged people. Bilateral occurrence of VAD is generally considered rare, but the number of reports of bilateral VAD has been increasing in recent years. In this paper, we report a case of de novo VAD on the contralateral side presenting with subarachnoid hemorrhage in the acute stage of cerebral infarction due to unilateral VAD.

Case Description

A 52-year-old man developed sudden-onset left occipital headache, dizziness, dysphagia, and right-sided hemiparesthesia and was admitted to our hospital. Head magnetic resonance imaging on admission showed a left lateral medullary infarction due to the left VAD. At this point, the right vertebral artery was normal. However, on day 9 after onset, he suddenly presented with subarachnoid hemorrhage due to the right VAD. Emergency endovascular treatment was performed for the dissecting aneurysm of the right vertebral artery. The patient's condition improved gradually after the procedure, and he was discharged with a modified Rankin Scale score of 1.

Conclusion

Bilateral occurrence of VAD may be more common than previously believed. Even in cases of unilateral VAD, we need to pay attention to the occurrence of de novo VAD on the contralateral side.

Endovascular reconstructive treatment using a fill-and-tunnel technique for a fusiform vertebral artery dissecting aneurysm with ipsilateral dominance

BACKGROUND

Fusiform dissecting aneurysms involving the dominant vertebral artery with poor collaterals are challenging to treat. The purpose of this study was to present an initial experience with a fill and tunnel technique for reconstructive endovascular treatment of these conditions.

METHODS

A total of 13 patients, 11 men and 2 women, each with a fusiform vertebral artery dissecting aneurysm not amenable to internal trapping of the parent artery, underwent reconstructive endovascular treatment using a fill and tunnel technique between January 2012 and December 2015. The safety, feasibility, and clinical and angiographic outcomes of these procedures were retrospectively evaluated.

RESULTS

The average maximum diameter of the fusiform aneurysms was 12.1 mm. Five were ruptured. Three aneurysms were treated with a single stent and the remaining 10 aneurysms required double-stent placement. Treatment was technically successful in all 13 patients, achieving complete occlusion (n = 10, 76.9%) and near-complete occlusion (n = 3, 23.1%). No procedure-related complications occurred in any patient. There were no delayed thromboembolic or hemorrhagic complications during the follow-up period (mean, 19.0 months). Angiographic follow-ups (mean, 9.1 months) showed stable occlusion in 90.9% (10/11) and asymptomatic in-stent occlusion in one patient (9.1%, 1/11). At the end of the observation period (mean, 19.0 months), all patients had excellent clinical outcomes (modified Rankin Scale (mRS) 0, 92.3%, 12/13), except one (mRS 4), resulting from poor preoperative status.

CONCLUSIONS

This retrospective study demonstrated that endovascular reconstruction using a fill-and-tunnel technique was a technically safe, feasible, and clinically effective treatment method for fusiform vertebral artery dissecting aneurysms with ipsilateral dominance.

Reconstructive endovascular treatment of the V4 segment of a vertebral artery dissecting aneurysm with the Willis covered stent: A retrospective study

OBJECTIVE

Preliminary studies suggest that Willis covered stents may be suitable for the treatment of aneurysms of the internal carotid artery (ICA), but their efficacy and safety in vertebral artery (VA) dissecting aneurysms need further investigation.

METHODS

Consecutive patients who underwent placement of a Willis covered stent for treatment of an aneurysm of the V4 segment of the VA between September 2015 and December 2017 at our institution were retrospectively reviewed. The efficacy, complications, angiographic and clinical follow-up results were collected and analyzed.

RESULTS

Sixteen covered stents were successfully implanted into the VA in 12 patients with 12 dissecting aneurysms. The technical success rate of stenting placement was 100%. Complete occlusion was achieved in 11 patients immediately after stent placement, with transient endoleak in one aneurysm. Angiographic follow-up (9.9 ± 4.0 months, mean±SD) was performed in nine patients and demonstrated complete stabilization of the obliterated aneurysm. Clinical follow-up (20.1 ± 9.6 months, mean±SD) demonstrated full recovery in 11 patients, and one patient suffered from acute myocardial infarction.

CONCLUSION

Reconstruction using a Willis covered stent is an efficient, safe and attractive alternative for the definitive treatment of intracranial VA dissecting aneurysms; longer follow-up and expanded clinical trials are needed for further validation of this technique.

Comparison of Clinical and Radiologic Outcomes of Diverse Endovascular Treatments in Vertebral Artery Dissecting Aneurysm Involving the Origin of PICA

OBJECTIVE

To determine clinical and radiologic outcomes of vertebral artery dissecting aneurysms involving posterior inferior cerebellar artery according to different types of endovascular treatment.

METHODS

This study included 18 vertebral artery dissecting aneurysms (6 ruptured and 12 unruptured) involving posterior inferior cerebellar artery treated from January 2009 to December 2016. Treatments were multiple stenting, stent-assisted coil embolization, vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting, and Pipeline embolization. Clinical and radiologic information were obtained from retrospective chart review and radiologic review.

RESULTS

Subarachnoid hemorrhage was diagnosed initially in 6 of 18 patients, and infarction was diagnosed initially in 2 patients. Multiple stenting was performed in 4 patients, including 1 (25%) who had cerebellar infarction and 1 (25%) who had recurrence. Stent-assisted coil embolization was performed in 8 patients, including 1 (12.5%) who had postoperative cerebellar infarction and 2 (25%) who had recurrence. Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting was performed in 4 patients, including 1 (25%) who had postoperative cerebellar infarction. There was no recurrence (0%). Pipeline embolization was performed in 2 patients, including 1 (50%) who had recurrence. There was no postoperative infarction (0%). No subarachnoid hemorrhage occurred during follow-up. Deterioration in modified Rankin Scale score was found only in the stent-assisted coil embolization group (1/8; 12.5%).

CONCLUSIONS

Vertebral artery trapping with vertebral artery-posterior inferior cerebellar artery stenting showed the lowest rate of aneurysm recurrence with high rate of minor infarction and favorable neurologic outcome. Stent-assisted coil embolization showed high recurrence rates with possible fatal disabling infarction.

Treatment outcomes in cerebral artery dissection and literature review

Methods Patients with cerebral artery dissections were reviewed in a hospital setting from 2008 to 2015. Clinical presentations, lesion locations, treatment modalities, functional outcomes, and mortality were reviewed. Parent artery occlusion was the first choice for surgery or endovascular treatment of a hemorrhagic dissecting cerebral artery. Endovascular or surgical reconstructive treatment was indicated in patients whose parent artery could not be occluded. Favorable functional outcomes were determined using modified Rankin Scale (mRS) scores of 0-2. Results In total, 61 patients with cerebral artery dissections were admitted to the hospital. Seven (11.5%) had traumatic dissections. All traumatic dissections were located in the internal carotid arteries. Overall favorable outcome rate was about 57% (4/7). Spontaneous cerebral artery dissections were found in 54 patients. No difference in favorable outcomes was observed between parent vessel occlusion and selective occlusion with parent vessel preservation (or vessel reconstruction) (70% and 63%, respectively, p = 1.000). Patients who presented with spontaneous dissection without intracranial hemorrhage had more favorable outcomes than those with intracranial hemorrhage (79% and 52%, respectively, p = 0.045). The mortality rate of patients with spontaneous dissection was 7.4%. Conclusions Most of the traumatic dissections were located on the internal carotid arteries and spontaneous dissections were commonly located on vertebral arteries. Nonhemorrhagic spontaneous cerebral dissections had better functional outcomes after treatment. Endovascular and surgical management were effective treatments by parent vessel occlusion or reconstructions.

Revascularization of the upper posterior circulation with the anterior temporal artery: an anatomical feasibility study

OBJECTIVE In various disease processes, including unclippable aneurysms, a bypass to the upper posterior circulation (UPC) including the superior cerebellar artery (SCA) and posterior cerebral artery (PCA) may be needed. Various revascularization options exist, but the role of intracranial (IC) donors has not been scrutinized. The objective of this study was to evaluate the anatomical feasibility of utilizing the anterior temporal artery (ATA) for revascularization of the UPC. METHODS ATA-SCA and ATA-PCA bypasses were performed on 14 cadaver specimens. After performing an orbitozygomatic craniotomy and opening the basal cisterns, the ATA was divided at the M₃-M₄ junction and mobilized to the crural cistern to complete an end-to-side bypass to the SCA and PCA. The length of the recipient artery between the anastomosis and origin was measured. RESULTS Seventeen ATAs were found. Successful anastomosis was performed in 14 (82%) of the ATAs. The anastomosis point on the PCA was 14.2 mm from its origin on the basilar artery. The SCA anastomosis point was 10.1 mm from its origin. Three ATAs did not reach the UPC region due to a common opercular origin with the middle temporal artery. The ATA-SCA bypass was also applied to the management of an incompletely coiled SCA aneurysm. CONCLUSIONS The ATA is a promising IC donor for UPC revascularization. The ATA is exposed en route to the proximal SCA and PCA through the pterional-orbitozygomatic approach. Also, the end-to-side anastomosis provides an efficient and straightforward bypass without the need to harvest a graft or perform multiple or difficult anastomoses.

Quantitative Analysis of Intracranial Vertebrobasilar Dissecting Aneurysm with Intramural Hematoma After Endovascular Treatment Using 3-T High-Resolution Magnetic Resonance Imaging

OBJECTIVE

Quantitative measurements of intracranial vessel walls are reliable in 3-T high-resolution magnetic resonance imaging (HR-MRI). However, few reports have assessed the arterial wall after endovascular treatment (EVT) by 3-T HR-MRI. This study aimed to quantitatively analyze vessel walls in vertebrobasilar artery dissecting aneurysms after EVT.

METHODS

From May 2012 to December 2015, a total of 21 patients with 21 intracranial vertebrobasilar dissecting aneurysms (VBDAs) were enrolled in this consecutive study. All the VBDAs were characterized by intramural hematomas (IMHs ≥5 mm) and treated with reconstructive EVT. Images of preoperative and follow-up 3-T HR-MRI were used to evaluate the arterial wall. The relative signal intensity (RSI) of IMHs was quantified on T1-weighted imaging (T1WI) and magnetization-prepared rapid acquisition gradient-echo (MPRAGE).

RESULTS

Angiographic follow-up was performed for a mean of 9.19 ± 3.22 months. According to angiographic results at follow-up, 21 patients were divided into 2 groups (progressive group, n = 6; stable group, n = 15). In the progressive group, RSI of IMHs was significantly increased on MPRAGE of follow-up 3-T HR-MRI compared with that before treatment (P < 0.05), and the difference was not significant on T1WI. However, in the stable group, RSI of IMHs was significantly reduced after treatment (P < 0.05).

CONCLUSIONS

Persistent high signal intensity of IMHs in VBDAs after reconstructive EVT may be associated with the progression of VBDAs. It may also indicate an unsteady state of the aneurysm, which suggests that reconstruction of the parent artery is not satisfactory.

Effect of Headache on the Pathologic Findings of Unruptured Cerebral Saccular Aneurysms

BACKGROUND

Some patients with aneurysm exhibit warning headaches without minor bleeding, and this could be caused by stretching of the aneurysm wall. Recently, our pathologic study observed subintimal fibrin deposition in a majority of the ruptured aneurysms. However, these findings also were observed in some unruptured aneurysms. In this report, 2 unruptured aneurysms exhibited subintimal fibrin, and interestingly, one of the patients experienced severe headache within 1 month before neuroimaging.

OBJECTIVE

We performed pathologic analysis of unruptured aneurysms and collected their various clinical variables, including severe headache, to clarify the clinical characteristics of "dangerous" unruptured aneurysms.

METHODS

This study included unruptured saccular aneurysm samples (n = 17) that were resected after clipping. We compared the differences in clinical variables, including warning headache, between aneurysms with and without fibrin deposition.

RESULTS

Fibrin deposition was present in the subintimal layer in 4 patients and in the periouter membrane in 4 patients. Three of the 4 former patients experienced warning headaches, and one presented aneurysm growth. Of the latter 4 patients, one exhibited aneurysm growth, whereas the others presented with relatively large aneurysms. In the remaining 9 aneurysms without fibrin deposition, monocyte infiltration was observed in one, all aneurysms were small, and no patients experienced warning headaches or aneurysm growth.

CONCLUSIONS

Subintimal fibrin deposition is observed frequently in patients with aneurysm with warning headaches. These pathologic findings are clinically inspiring and may suggest that these aneurysms exhibit rapid stretching by newly formed aneurysms, which can result in rupture at an early stage.

Basilar artery dissection: A rare complication of posterior fossa epidermoid cyst resection, and evaluation of the possible effects of cerebrospinal fluid drainage on disease progression

We report a rare case of a 45-year-old female with an unruptured basilar artery dissecting aneurysm presenting with locked-in syndrome due to brainstem ischemia eleven months following resection of a giant cerebellopontine angle epidermoid cyst and three months after insertion of ventriculo peritoneal shunt due to hydrocephalus. The etiology of basilar artery dissection and the effect of hydrocephalus and ventricular cerebrospinal fluid drainage on disease progression in this patient are unclear. Our report suggests a possible effect of hydrocephalus and ventricular cerebrospinal fluid drainage on intracranial arterial dissection progression.

Evaluation of the Arterial Wall in Vertebrobasilar Artery Dissection Using High-Resolution Magnetic Resonance Vessel Wall Imaging

BACKGROUND

High-resolution magnetic resonance vessel wall imaging (HRMR-VWI) has been used to explore vascular diseases such as vasculitis and vulnerable plaque of intracranial arteries. Although vessel wall inflammation is suspected as one of the causes of cerebral arterial dissection, there have been few reports regarding the application of HRMR-VWI to arterial dissection. We have therefore evaluated the efficacy of HRMR-VWI in patients with vertebrobasilar artery dissection.

METHODS

HRMR-VWI was performed on 5 patients who had been diagnosed with nonhemorrhagic vertebrobasilar artery dissection.

RESULT

Four patients exhibited vessel wall enhancement on HRMR-VWI, the range of which corresponded with the dissection sites identified by cerebral angiogram, magnetic resonance imaging, or magnetic resonance angiography. The enhancements observed in all cases were extensive as compared with the findings of conventional angiography.

CONCLUSION

HRMR-VWI is thought to elucidate the condition of the affected vessel wall more in detail as compared with conventional methods.

High-Resolution Magnetic Resonance Imaging of Intracranial Vertebral Artery Dissecting Aneurysm for Planning of Endovascular Treatment

The equipment and techniques associated with magnetic resonance imaging (MRI) have rapidly evolved. The development of 3.0 Tesla MRI has enabled high-resolution imaging of the intracranial vessel wall. High-resolution MRI (HRMRI) can yield excellent visualization of both the arterial wall and lumen, thus facilitating the detection of the primary and secondary features of intracranial arterial dissection. In the present report, we describe the manner in which HRMRI affected our endovascular treatment planning strategy in 2 cases with unruptured intracranial vertebral artery dissection aneurysm. HRMRI provides further information about the vessel wall and the lumen of the unruptured intracranial vertebral artery dissecting aneurysm, which was treated by an endovascular approach in the 2 current cases.

Reconstructive Endovascular Treatment of Spontaneous Symptomatic Large or Giant Vertebrobasilar Dissecting Aneurysms: Clinical and Angiographic Outcomes

PURPOSE

To investigate the clinical and angiographic outcomes of spontaneous symptomatic large or giant vertebrobasilar dissecting aneurysms (VBDAs) following reconstructive endovascular treatment (EVT) with stent(s).

METHODS

We retrospectively identified 21 patients with spontaneous symptomatic large or giant VBDAs who had been treated with reconstructive EVT between September 2009 and September 2013 in our department. There were 20 men and 1 woman, with a mean age of 46.5 years (range: 17-67 years). Clinical and angiographic data were reviewed and evaluated.

RESULTS

Reconstructive EVT with sole stenting (SS, 10 cases) or stent-assisted coiling (SAC, 11 cases) technique was technically feasible in all cases. Angiographic follow-up results confirmed delayed thrombosis of the aneurysm sac in only two of the eight cases after SS, and recurrence of the aneurysm sac in six of the nine cases after SAC. Postoperative complications or poor neurologic outcomes occurred in seven cases (33.3 %). Three patients died after SS, including postoperative subarachnoid hemorrhage in one case and pulmonary embolism in one case. The other patient died soon after SAC, without radiologic result to confirm the causes of death. Other adverse events after treatment include ischemic complication in two cases, intramural hemorrhage in one case, aggravation of initial mass effect in one case. As to the other 14 cases, the post-procedural processes were uneventful and no complication was observed. The condition of them was improved in seven cases (33.3 %), and unchanged in seven cases (33.3 %) during follow-up.

CONCLUSIONS

Reconstructive EVT with traditional intracranial stent(s) for the treatment of large and giant VBDAs carries a high failure rate and substantial risk of complications. The outcome of treating these difficult lesions with traditional intracranial stenting seems questionable and unpredictable.

Basilar extension and posterior inferior cerebellar artery involvement as risk factors for progression of the unruptured spontaneous intradural vertebral artery dissection

BACKGROUND AND PURPOSE

Spontaneous intradural vertebral artery dissection (siVAD) primarily causes stroke in young and middle-aged individuals; however, data on the relationship between vertebrobasilar morphology and the progression of siVAD are limited.

METHODS

We retrospectively reviewed the data of 77 adult patients who were diagnosed with unruptured siVAD and treated conservatively. We analysed the clinical characteristics, vertebrobasilar morphologies and progression. Progression was defined as siVAD-induced stroke or morphological worsening of the siVAD.

RESULTS

Twenty patients experienced progression. Recurrent ischaemic events that occurred in the vertebrobasilar territory were seen in three patients (3.9%). Two of these three patients and other 17 patients showed morphological worsening. None of the patients presented with subarachnoid haemorrhage. The log-rank test showed male sex, migraine, basilar extension and the posterior inferior cerebellar artery involvement were associated with the progression. Multivariate analysis using the Cox proportional hazards model showed that only basilar extension and the posterior inferior cerebellar artery involvement were significantly related to the progression (p=0.012 and 0.019). In addition, patients with these two vertebrobasilar morphologies had a significantly shorter period of progression of siVAD than those without these morphologies (both, median 242 days; one of two, median 1292 days; none, median 2445 days).

CONCLUSIONS

Thus, some vertebrobasilar morphologies might be markers of the progression of unruptured siVAD. Although all unruptured siVAD patients should be closely monitored, those with basilar extension and posterior inferior cerebellar artery involvement should perhaps be more carefully followed than those without such morphologies.

Fusiform superior cerebellar artery aneurysm treated with STA-SCA bypass and trapping

BACKGROUND

Fusiform aneurysms of cerebellar arteries are rare. Different surgical techniques to address these challenging lesions have been described, and their application depends on whether the goal is to maintain the flow in the parent vessel or to occlude it.

CASE DESCRIPTION

The authors reported a case of a fusiform aneurysm located in the lateral pontomesencephalic segment of the superior cerebellar artery (SCA) in a 32-year-old man who presented with subarachnoid hemorrhage. The patient was subjected to aneurysm trapping followed by a bypass between the superficial temporal artery (STA) and SCA and had an uneventful recovery.

CONCLUSIONS

Although only a few cases of fusiform aneurysms in the supracerebellar artery have been reported in the literature, the treatment strategies adopted were diverse. In selected cases of patients in good neurological condition with ruptured fusiform aneurysms at the proximal segments of SCA and who have poor evidence of collateral supply, the possibility of a STA-SCA bypass with aneurysm trapping must be considered. A review of the current treatment modalities of this pathology is also presented.

Imaging investigation of intracranial arterial dissecting aneurysms by using 3 T high-resolution MRI and DSA: from the interventional neuroradiologists' view

OBJECTIVES

The purpose of this study was to investigate vessel wall imaging features combined with the luminal shapes of intracranial dissecting aneurysms (IDAs) by using 3 Tesla (3T) high-resolution magnetic resonance imaging (MRI) and digital subtraction angiography (DSA).

METHODS

Sixty-seven patients with 76 IDAs were consecutively enrolled in the study from December 2011 to May 2013. DSA was performed to diagnose an IDA and to categorize its angiography patterns into either aneurysmal dilation, steno-occlusive, combined, or unclassifiable. Images of 3T high-resolution MRI were used to evaluate arterial wall imaging features of each lesion. Chi-squared tests were used for statistical analyses.

RESULTS

Aneurysmal dilation (51 of 76, [67%]) was the most common angiography pattern of IDAs, followed by the combined pattern (20 of 76, [26%]). Seven percent (five of 76) of IDAs showed steno-occlusive (n = 3) and unclassifiable (n = 2) angiography patterns, in which intramural hematomas were detected in the arterial wall without luminal connection. Intimal flaps (32 of 76, [42%]), double-lumen sign (38 of 76, [50%]) and intramural hematomas (46 of 76, [61%]) were recognized as the characteristic features of dissection by high-resolution MRI. Intramural hematomas occurred more frequently in the combined patterns group (16 of 20, [80 %]) than in the aneurysmal dilation group (25 of 51, [49%]) (P = .017), while the occurrence of intimal flaps and double-lumen sign did not differ between angiographic patterns (P > .05).

CONCLUSIONS

3T high-resolution MRI combined with DSA offered clear visualization of vessel wall features and accurate assessment of the vessel lumen in IDAs. This combined approach would be highly useful for understanding the underlying pathological status of IDAs and in guiding treatment choices.

Internal trapping of a ruptured vertebral artery dissecting aneurysm followed by recanalization of the trapped vertebral artery without aneurysm recurrence: case report

A 61-year-old man presented with a ruptured vertebral artery dissecting aneurysm manifesting as severe headache, which was treated by internal trapping, and later resulted in recanalization of the affected vertebral artery without aneurysm recurrence. Computed tomography revealed subarachnoid hemorrhage caused by a dissecting right vertebral artery aneurysm located just distal to the origin of the posterior inferior cerebellar artery. The patient underwent uneventful internal trapping. However, recanalization of the affected vertebral artery with stenosis was found on the 22nd postoperative day, apparently caused by insufficient thrombosis related to the short trapping length. No aneurysm recurrence or ischemic events were detected, so the patient was observed carefully. After 4 months, right vertebral angiography revealed that the vertebral artery was normal with no stenosis or aneurysm. Restoration of the vertebral artery without complication probably occurred by complete thrombosis of the aneurysm followed by reconstruction of the injured arterial wall. We adopted a conservative approach in this case, but additional embolization and/or stenting should be considered if high risk of rebleeding is suggested by angiographic findings, although the management of recanalization remains controversial.

Long-term follow up of antegrade recanalization of vertebral artery dissecting aneurysm after internal trapping: case report

A 34-year-old female presented with subarachnoid hemorrhage caused by the rupture of a right vertebral artery (VA) dissecting aneurysm. The affected site, including the aneurysm and parent artery, was successfully occluded with detachable coils. Follow-up angiography performed 28 days after the endovascular treatment revealed recanalization of the parent artery. We decided to treat the patient conservatively without further intervention because the aneurysm had been completely occluded. Magnetic resonance imaging showed a normal VA configuration with a minor irregularity of the affected wall at 6 years after onset. Rebleeding tends to occur during the acute stage because spontaneous healing of the dissecting vascular wall typically occurs within one month after onset. Our case suggests that additional intervention is unnecessary during the chronic stage once the aneurysm has been occluded and no further signs of the development of VA dissection are found.

Simultaneous vertebral artery dissection and contralateral posterior inferior cerebellar artery dissecting aneurysm

The optimal treatment and appropriate follow-up period for an unruptured vertebral artery (VA) and/or posterior inferior cerebellar artery (PICA) dissection have not been established. Decisions regarding treatment of these vascular lesions are usually based on the manifesting symptoms and changes in radiologic findings during the follow-up period. We experienced a patient who had a simultaneous unruptured VA dissection and a contralateral PICA dissecting aneurysm. We did not find such a case in other literature.

Recanalisation of spontaneously occluded vertebral artery dissection after subarachnoid haemorrhage

Spontaneous occlusion is a rare manifestation of ruptured vertebral artery dissection (VAD). Its natural history and treatment strategy have yet to be established due to its rarity. Here, we report five lesions involving spontaneous occlusion of VAD after subarachnoid haemorrhage, among which three lesions showed recanalisation. Based on our experience and previous reports, spontaneous occlusion of ruptured VAD can be classified into two groups-one group with occlusion in the acute stage with a high incidence of recanalisation and another group with occlusion in the chronic stage with a relatively low incidence of recanalisation. The underlying mechanism is likely different in each group, and treatment strategies should also be tailored depending on the pathophysiology.

Antegrade recanalization of parent artery after internal trapping of ruptured vertebral artery dissecting aneurysm

We report a patient with a ruptured vertebral artery (VA) dissecting aneurysm that was treated by internal trapping of the aneurysm and parent artery using detachable coils with subsequent antegrade recanalization of occluded vertebral artery during the follow-up period. A 38-year-old man was admitted with a ruptured right VA dissecting aneurysm just distal to origin of right posterior inferior cerebellar artery. The dissected segment of the VA was occluded by coil embolization. The 14 months follow-up angiography showed that dissected aneurysm was completely occluded, but the parent artery was recanalized in an antegrade fashion. Based on this unique case, the authors suggest that careful angiographic follow-up of dissecting aneurysm is required, even in patients successfully treated with endovascular occlusion of the affected artery and aneurysm.

Spontaneous symptomatic intracranial vertebrobasilar dissection: initial and follow-up imaging findings

PURPOSE

To evaluate initial radiologic findings of symptomatic intracranial vertebrobasilar dissections (VBDs) as well as the results at follow-up imaging of dissections that are conservatively managed.

MATERIALS AND METHODS

The respective institutional review boards approved this retrospective study and waived the need for informed consent. The initial radiologic findings of 210 patients with 230 symptomatic intracranial VBDs were retrospectively evaluated (48 ruptured, 182 unruptured). Those patients had undergone conventional angiography as well as magnetic resonance imaging and/or computed tomographic angiography, so that angiographic shapes and pathognomonic findings (eg, intramural hematoma, intimal flap) could be reviewed. The primary angiographic shapes of the symptomatic intracranial VBDs were subdivided into three groups: (a) dilatation without stenosis, (b) pearl-and-string, and (c) stenosis without dilatation. Furthermore, the radiologic evolution of conservatively managed symptomatic intracranial VBDs was evaluated. The respective frequencies of the radiologic findings at initial and follow-up imaging studies were compared by using χ2 tests.

RESULTS

Primary shape differed significantly between ruptured and unruptured symptomatic intracranial VBDs. Most ruptured dissections presented with one of two main structures: dilatation without stenosis or pearl-and-string appearance. The primary shape of unruptured dissections was evenly distributed among the three types of findings. Intramural hematomas were most frequently found in the stenosis-without-dilatation group (42 of 60 [70%]), followed by the pearl-and-string group (27 of 90 [30%]). Intimal flap was most frequently found in the pearl-and-string group (21 of 90 [23%]), followed by the stenosis-without-dilatation group (eight of 60 [13%]). Follow-up results significantly differed by initial VBD shapes: Seventy-four percent (25 of 34) of the dilatation-without-stenosis group showed no change, whereas improvement was observed in 91% (39 of 43) of the stenosis-without-dilatation group (P<.05). Intracranial VBDs with intramural hematoma showed improvement in 63% (34 of 54) of cases, progression occurred in 20% (11 of 54), and only 17% (nine of 54) exhibited no change (P<.05).

CONCLUSION

Primary angiographic shapes of symptomatic intracranial VBDs differed between ruptured and unruptured lesions. The stenosis-without-dilatation lesions most frequently exhibited radiologic improvement at follow-up imaging, followed by pearl-and-string and dilatation-without-stenosis lesions.

Long-term outcome of endovascular reconstruction with the Pipeline embolization device in the management of unruptured dissecting aneurysms of the intracranial vertebral artery

Object

Use of a flow-diverting device has shown promising short-term results in the management of vertebral artery (VA) dissecting aneurysms, but there is still uncertainty regarding its long-term efficacy and safety. The authors report their initial experience with respect to the potential utility and long-term clinical outcomes of using a flow-diverting device in the treatment of unruptured dissecting VA aneurysms.

Methods

The authors conducted a retrospective review of all cases of unruptured intracranial VA dissecting aneurysms treated at their institution (Tuen Mun Hospital) with a flow-diverting device. They describe the clinical presentations and angiographic features of the cases and report the clinical outcome (with modified Rankin Scale [mRS] scores) at most recent follow-up, as well as results of the latest angiographic assessment, with particular focus on in-stent patency and side-branch occlusion.

Results

A total of 4 aneurysms were successfully obliterated by using flow-diverting devices alone. Two devices were deployed in a telescoping fashion in each of 2 aneurysms, whereas only 1 device was inserted in each of the other 2 aneurysms. No periprocedural complication was encountered. No patient showed any angiographic evidence of recurrence, in-stent thrombosis, or side-branch occlusion in angiographic reassessment at a mean of 22 months after treatment (range 18–24 months). As of the most recent clinical follow-up (mean 30 months after treatment, range 24–37 months), all patients had favorable outcomes (mRS Score 0).

Conclusions

Reconstruction using a flow-diverting device is an attractive alternative in definitive treatment of dissecting VA aneurysms, demonstrating favorable long-term clinical and angiographic outcomes and the ability to maintain parent artery and side-branch patency. It is particularly useful in cases with eloquent side-branch or dominant VA involvement.

Treatment of ruptured intra-cranial internal carotid artery dissection using a flow-diverter stent

In the presence of associated subarachnoid hemorrhage, the treatment of arterial dissection can be classified as either deconstructive (involving occlusion or sacrifice of the parent vessel) or reconstructive (preserving blood-flow through the parent vessel). In both treatment strategies, the main goal is to prevent any further risk of rebleeding. However, reconstructive treatment is reserved only for those patients in whom occlusion of the parent vessel is not feasible due to an insufficient collateral supply. This report is of a case of intra-cranial carotid artery dissection treated by a reconstructive endovascular approach, with deployment of a flow-diverter stent, for the management of an associated subarachnoid hemorrhage. This is, to the authors' knowledge, the first report of the use of a flow-diverter device as the main treatment of a ruptured supraclinoid carotid artery dissection.

Treatment of Spontaneous Intradural Vertebral Artery Dissections

Spontaneous intradural vertebral artery dissections may cause subarachnoid hemorrhage and often result in devastating damage. Increased use of noninvasive imaging studies has allowed larger numbers of patients to be diagnosed. In addition, intracranial vertebral artery dissection tends to induce multiple lesions affecting both intracranial vertebral arteries recurrently. Although unruptured dissections in this area usually have a benign nature, some authors have reported on the incidence of rupture from this lesion. Once hemorrhage from a dissecting vessel wall has occurred, it needs to be treated in the acute phase because of the high risk of rebleeding resulting in high morbidity and mortality. From December 2004 to July 2010, we managed 47 patients with spontaneous vertebral artery dissection, 31 patients were ruptured and 16 were unruptured. All patients who suffered from subarachnoid hemorrhage were treated with endovascular procedures. Most of the patients with unruptured dissection received medical therapy, but if the aneurysmal dilatation persisted or grew, surgical interventions were performed. Stenting with or without coils was deployed for 13 patients with posterior inferior cerebellar artery involvement at the site of dissection and/or were affected on the dominant side. In some patients, stenting was performed even if they were in the acute phase. For other ruptured patients, internal coil trappings were performed. Six patients died due to severe initial subarachnoid hemorrhage and one patient, who underwent stent deployment with coils for the dominant vertebral artery, with bilateral dissection continuing to the basilar artery died due to rerupture while the next additional coiling was planning. There were two cases of complications related to the intervention. During the follow-up period no bleeding occurred in any of the patients except for the previously mentioned patient. In conclusion, internal coil trapping or stent placement with or without coils was effective in preventing rebleeding of ruptured vertebral artery dissection. If the dissection is unruptured, it is necessary to detect the risk of bleeding with careful watching and when progress appears to be made, patients should be treated promptly. Stent-assisted therapy for preserving the patency of the parent artery and major branches is a promising treatment for vertebral artery dissection, even in the acute stage of subarachnoid hemorrhage. However, the risk of acute rerupture and recurrence remains even with the porous stent placement with or without coils.

Strategy for Treating Unruptured Vertebral Artery Dissecting Aneurysms

BACKGROUND

The natural course of unruptured vertebral artery dissecting aneurysms (VADAs) remains unclear.

OBJECTIVE

The purpose of this retrospective study was to develop a strategy for treating unruptured VADAs based on long-term follow-up.

METHODS

Our study population consisted of 100 patients with unruptured VADAs; in 66, the initial symptom was headache only, 30 presented with ischemic symptoms and 4 with mass effect. All underwent magnetic resonance imaging and magnetic resonance angiography at the time of admission and 2 weeks and 1, 3, 6, 12, and 24 months after the onset. If the dissection site was demonstrated to be enlarged on magnetic resonance imaging and magnetic resonance angiography without the manifestation of new symptoms, the patients received additional treatment to prevent bleeding.

RESULTS

Of the 100 patients, 4 underwent early intervention because of symptom exacerbation. The other 96 were initially treated conservatively; during follow-up, 5 manifested lesion enlargement on magnetic resonance angiography. Nine patients received additional treatment; 1 underwent direct surgery with trapping of the dissection site, and 8 underwent coil embolization. The other 91 patients continued to be treated conservatively; the dissection site remained unchanged in 70, improved or healed in 18, and disappeared in 3 patients. We treated 38 patients with recurrent ischemic attacks with antiplatelet therapy. No patients experienced bleeding or permanent neurological deficits during follow-up.

CONCLUSION

The nature of an unruptured VADA is not highly aggressive. However, if the dissection site enlarges without the manifestation of new symptoms, it should be occluded. In patients with recurrent ischemic attacks antiplatelet therapy should be considered.

Natural course of intracranial arterial dissections

Object

Noninvasive neuroimaging techniques are increasingly identifying unruptured intracranial arterial dissections (IADs) at examination for headache or ischemic symptoms. Approximately 3% of cases of aneurysmal subarachnoid hemorrhage (SAH) are caused by IADs in Japan, but the natural history of unruptured IADs is not known.

Methods

Clinical data obtained in 190 patients with 206 IADs were retrospectively analyzed on the basis of long-time follow-up of geometry and clinical event. The IADs were divided into an unruptured group and SAH group depending on the patient's clinical status at the initial diagnosis. Day 0 was defined as the day preceding diagnosis of IAD—that is, the day of symptom onset. This was retrospectively determined from the clinical history.

Results

The 206 IADs included 98 unruptured lesions and 108 SAH. In both groups, the vertebral artery was the most frequent site. In the unruptured group, 93 IADs were followed for a mean of 3.44 years. The mean interval between symptom onset (Day 0) and neuroimaging diagnosis was 9.8 days. Subsequent geometry change was seen in 78 (83.9%) of 93 IADs. Major change was almost completed within 2 months, and complete normalization was seen on neuroimaging in 17 (18.3%) of 93 IADs, with the earliest on Day 15. Rupture of the IAD in the unruptured group occurred in only 1 patient on Day 11.

In the SAH group, 84 of the 108 patients complained of preceding headache before onset of SAH. In 81 (96.4%) of the 84 patients, SAH occurred on Day 0–3 with the latest on Day 11. In all patients in the unruptured and SAH groups, the latest day of SAH from the onset of preceding headache was Day 11.

Conclusions

Most IADs causing SAH bleed within a few days of occurrence. Most IADs that are unruptured already have little risk for bleeding at diagnosis because of the repair process. Intracranial arterial dissections may be much more common than previously thought, and the majority may occur and heal without symptom manifestation.

Endovascular coil embolization for saccular-shaped blood blister-like aneurysms of the internal carotid artery

BACKGROUND

Because of their fragile and thin wall, ruptured blood blister-like aneurysms (BBAs) at the anterior wall of the internal carotid artery (ICA) are difficult to manage, both surgically, as well as endovascularly. BBA is usually a tiny and broad-necked aneurysm, but it occasionally demonstrates a relatively saccular-like shape. In addition, the pseudoaneurysm sac often assumes a saccular shape. In this paper, the authors present their experience in treating these saccular-shaped BBAs endovascularly with coil packing.

METHOD

Nine saccular-shaped ruptured BBAs in nine patients (one male and eight females; mean age 51.3 years, range 38-76) were treated with coil packing of the lesion between January 2006 and August 2010 in Nagoya University and its affiliated hospitals. Clinical, procedural, and angiographic data were retrospectively evaluated.

FINDINGS

Seven BBAs were treated by balloon-assisted coil embolization. Two remaining BBAs were embolized without balloon inflation, though a balloon catheter was on standby at the ICA. In one case, in which a saccular coil embolization could not be achieved, ICA trapping was performed. Three (33.3%) were treated in acute, two (22.2%) in subacute, and four (44.4%) in chronic period. One (11.1%) intraoperative rupture occurred. Six (66.7%) had excellent clinical outcomes, while two (22.2%) proved fatal outcomes. During the follow-up period (mean 18.9 months, range 4-48), two out of seven (28.6%) aneurysms presented an angiographical recurrence, but both were treated by coil embolization without complications. The remaining five (71.4%) aneurysms were completely resolved.

CONCLUSIONS

Endovascular coil embolization can be considered as an alternative treatment option for selective saccular-shaped BBAs.

Successful treatment of bilateral vertebral artery dissecting aneurysms with subarachnoid hemorrhage: report of three cases

Vertebral artery dissecting aneurysm (VADA) is a relatively rare cause of subarachnoid hemorrhage (SAH). Bilateral VADAs are even rare, and management strategies for this type of VADAs are still controversial. Here, we report 3 cases of bilateral VADAs with SAH. All 3 patients were treated conservatively under strict sedation and blood pressure control during the acute stage. During the course, rebleeding was not observed in any case. One patient underwent trapping of the ruptured VADA on day 28, because this lesion was considered to have a high tendency to rebleed, even in the chronic stage. In the other 2 patients, after conservative treatment, the VADAs spontaneously resolved on the both sides. As for the therapeutic strategy for bilateral VADAs presenting with SAH, at the acute stage, considering the difficulty of bypass surgery, we recommend conservative treatment with sedation and strict control of blood pressure. At the chronic stage, however, when the VADA is still large and growing in size, surgical treatment such as proximal occlusion or trapping of the affected VA with or without distal revascularization should be considered to avoid rebleeding.