PICA injury secondary to anterior odontoid screw fixation: Case report of an exceptional complication.

BACKGROUND: Odontoid fracture is a common injury in the upper cervical spine that can sometimes be managed by anterior odontoid screw fixation. CASE DESCRIPTION: We report the first case of iatrogenic postero-inferior cerebellar artery (PICA) injury while performing anterior odontoid screw fixation for a type II odontoid fracture in a 22-year-old man. Fisher grade 4 subarachnoid hemorrhage secondary to iatrogenic pseudoaneurysm formation was managed by the endovascular neuroradiologist. Odontoid fracture was then managed posteriorly using Harm's technique. Postoperative 12-month follow-up revealed good clinical and radiological results. CT scan showed fusion. Complete exclusion of the pseudo aneurysm with a mild stroke in the inferior left cerebellar hemisphere were noted on the MRI. There were no cerebellar ataxia or swallowing disorders. CONCLUSION: To the best of our knowledge, this is the first case report of iatrogenic PICA injury in anterior odontoid screw fixation. The patient was well managed in our institution within a multidisciplinary team. We recommend that surgical management of odontoid fractures should be performed in expert centres.

Expanded transnasal approaches to the skull base in the Middle East: Where do we stand?

BACKGROUND: Endoscopic transnasal surgery has gained rapid global acceptance over the last two decades. The growing literature and understanding of anterior skull base endoscopic anatomy, in addition to new dedicated endoscopic instruments and tools, have helped to expand the use of the transnasal route in skull base surgery. OBJECTIVE: Report our early experience in expanded endoscopic transnasal surgery (EETS) and approach to skull base neoplasms. DESIGN: Descriptive, retrospective case series. SETTING: Major tertiary care center. PATIENTS AND METHODS: A retrospective case review was conducted at King Saud University Medical City between December 2014 and August 2019. Cases with skull base neoplasms that underwent EETS were included. EETS was defined as endoscopic surgical exposure that extended beyond the sellar margins (prechiasmatic sulcus superiorly, clival recess inferiorly, cavernous carotid lines laterally). Routine transsphenoidal pituitary neoplasms, neoplasms of sinonasal origin and meningoencephaloceles were excluded. MAIN OUTCOME MEASURES: Preoperative clinical assessment, imaging results, surgical approach, and hospital course were all retrieved from the patient electronic charts. Clinical follow-up, perioperative complications, and gross residual tumor rates were documented and reviewed. SAMPLE SIZE AND CHARACTERISTICS: 45 cases of EETS, 13 males and 32 females with mean age of 39.0 (17.7) years (range 2-70 years). RESULTS: The series comprised a wide range of pathologies, including giant pituitary adenoma (8 cases), meningioma (23 cases), craniopharyngioma (4 cases), chordoma (4 cases), optic pathway glioma (2 cases), epidermoid neoplasms (2 cases), astrocytoma (1 case), and teratoma (1 case). For the entire series, gross total resection was achieved in 25/45 operations (55.5%). Postoperative cerebrospinal fluid leak was the most common complication observed in 9 patients (20%) which were all managed endoscopically. Major vascular complications occurred in 2 patients (4.4%) and are described. Other complications are outlined as well. No mortality was observed. CONCLUSIONS: EETS to the skull base can be done with results comparable to traditional approaches. More work is needed to expand our experience, improve outcomes, and educate the public and medical community in our region about the usefulness of this approach. LIMITATIONS: Sample size and study design. CONFLICT OF INTEREST: None.

Magnetic resonance vessel wall imaging in cerebrovascular diseases

Cerebrovascular diseases manifest as abnormalities of and disruption to the intracranial vasculature and its capacity to carry blood to the brain. However, the pathogenesis of many cerebrovascular diseases begins in the vessel wall. Traditional luminal and perfusion imaging techniques do not provide adequate information regarding the differentiation, onset, or progression of disease. Intracranial high-resolution MR vessel wall imaging (VWI) has emerged as an invaluable technique for understanding and evaluating cerebrovascular diseases. The location and pattern of contrast enhancement in intracranial VWI provides new insight into the inflammatory etiology of cerebrovascular diseases and has potential to permit earlier diagnosis and treatment. In this report, technical considerations of VWI are discussed and current applications of VWI in vascular malformations, blunt cerebrovascular injury/dissection, and steno-occlusive cerebrovascular vasculopathies are reviewed.

Ruptured Posterior Inferior Cerebellar Artery Dural Fistula After Vestibular Schwannoma Resection.

A 50-year-old man with a history of left-sided retrosigmoid craniotomy for vestibular schwannoma (VS) resection 19 years prior presented with severe headache and left cerebellopontine angle subarachnoid hemorrhage (SAH). Digital subtraction angiography demonstrated a dissected, nonfunctional left posterior inferior cerebellar artery with direct fistulization at the left transverse sinus (Video 1). The lesion was treated with endovascular Onyx embolization. The patient recovered without neurologic deficit. Five additional cases of new dural arteriovenous fistula arising after VS resection have been described; we report the first such case presenting with SAH, suggesting that postoperative magnetic resonance angiography may be of value in long-term VS follow-up imaging protocols.

Cotton-Assisted Surgical Clipping of Very Small Aneurysms: A Two-Center Study.

OBJECTIVE: Very small intracranial aneurysms (VSIAs) are challenging to treat because aneurysm tearing and clip slippage can occur during neurosurgical clipping. In this study, we introduce and share our experience with cotton-assisted clipping of VSIAs. METHODS: We retrospectively analyzed the data of 20 patients with 24 VSIAs treated with cotton-assisted clipping between February 2008 and December 2014 in the Neurosurgery Departments of the First Affiliated Hospital, Soochow University and Taizhou People's Hospital. During surgery, 2 aneurysm necks were torn. To treat the tears, we wrapped rectangular cotton pads around the parental arteries at the site of rupture. The remaining 22 aneurysms were clipped after being wrapped in cotton pads. RESULTS: The 2 aneurysm ruptures were successfully repaired with cotton-assisted clipping. In the remaining 22 aneurysms, no cases of aneurysm clip slippage or aneurysm rupture occurred. Patients were followed up on average for 59.0 months (range, 30-113 months). Of the 20 patients, the 16 patients with preoperative Hunt-Hess grades of 1-3 recovered well after the surgery (Glasgow Outcome Scale [GOS] score, 5). Of the 4 patients with Hunt-Hess grades of 4-5, 3 had a good recovery (GOS scores, 4-5), and 1 patient died of heart disease 6 months after being discharged from the hospital; this patient had a GOS score of 4 at the time of discharge. CONCLUSIONS: Cotton-assisted clipping could prevent aneurysm clip slipping and aneurysm rupture and facilitate the repair of aneurysm neck tears. This technique is a useful alternative therapy for VSIAs.

Pathological Safety Assessment in Preclinical Neurothrombectomy Studies.

The design, production, and preclinical testing of neurothrombectomy devices is in a burgeoning phase as the demand escalates for safe and reliable treatment options following neurovascular stroke. Currently, there is a paucity of published data describing the development of iatrogenic vascular lesions occurring secondary to neurothrombectomy procedures. In an effort to test new devices, demonstrate device safety, satisfy regulatory requirements, and develop an understanding of the potential for associated vascular pathology, investigators are establishing appropriate methodology in suitable animal models. Significant challenges exist in identifying a single animal species that can be consistently utilized in all phases of device development. These aforementioned challenges are underscored by the intricacies of neurovascular pathology, thrombovascular interactions, and vascular responses to injury.

Stent-assisted coiling of posterior inferior cerebellar artery aneurysm complicated by arterial avulsion.

BACKGROUND: Rapid development of new devices and techniques in endovascular neurosurgery allows treatment of complex intracranial vascular lesions. These treatments, however, are not without risk. We report a case of unusual vascular laceration during stent-assisted coiling of a posterior inferior cerebellar artery (PICA) aneurysm. CASE PRESENTATION: A 75-year-old female with a recurrent, previously coiled PICA aneurysm developed avulsion of the parent vessel followed by fatal bleeding while an attempt was made to place a microcatheter across the aneurysmal neck for stent-assisted coiling. CONCLUSIONS: Pathological examination was performed to understand the mechanism of the rupture. The most likely mechanism was straightening of the significant vascular tortuosity, excessive tension on the vessel origin and avulsion upon advancement of the microcatheter over the microguidewire.

Cervicocranial artery dissection and scuba diving: Is there a link or is it serendipity?

INTRODUCTION: Numerous reports have documented cervicocranial artery dissection (CCAD) associated with scuba diving. The question remains as to whether there are risk factors unique to scuba diving related to the occurrence of CCAD. OBJECTIVES: This article aims to perform an examination of the reported cases to demonstrate any commonality among the injured divers and association with known risk factors for CCAD. METHODS: A PubMed search was performed utilizing the key words: carotid artery dissection, dissection, arterial dissection, cranial artery dissection, scuba, diving, scuba diving. Articles including reports, reviews, trials, case series, and letters were considered. Each report was critically dissected for information specific to the dive itself and the diver and analyzed for similarities and consistency with known risks. RESULTS: Twelve (12) reports of CCAD associated with scuba diving were identified. Activities involved with scuba diving appear to be consistent with CCAD risk factors. It is unclear if hyperbaric stress and physiological changes during a dive present specific risk. Trauma - e.g., environmental protection and activities associated with diving - was identified as a common risk factor in all cases. Ten (10) cases involved arteries at anatomic sites commonly associated with dissections. Seven divers documented to have dive profiles suspicious of decompression sickness were identified. CONCLUSIONS: There appears to be a correlation with minor traumas that occur with diving and CCAD. The inconsistency of the dive-related specific information reported makes it impossible for investigation of hyperbaric stress-related risk factors for CCAD to be analyzed.

Trauma of the extracranial cerebral arteries due to injuries of the cervical spine.

INTRODUCTION: Cervical spine injuries are immanently accompanied by trauma to cerebral neck arteries. METHOD: A prospective two-cohort study, from oct. 2013 to oct. 2015. Overall 76 Patients (39W/37M) of median age 77 years, with either fractures or discoligamentary injuries have been examined with duplex-sonography and or CT-angiography. From October 2013 to October 2017 we examined 155 Patients (49% female and 51% male), with the average age of 39 years, SD 19 and age median of 34 years, with cervical-spine-distortion, using the same diagnostic modalities. We used the statistics-program Bias 11.01. RESULTS: The overall incidence of traumatic dissection of the internal carotid artery was 2.5%, in 50% of cases (1.2%) with neurological symptomato-logy. For the vertebral artery seems the incidence of 10.5%, with 25% of symptomatic patients (2.6%) comparably high. We have identified the osteophytes and dislocation as the significant risk factors. The canalis vertebralis and the skull-base are regions mostly prone to vascular injury. In the group of cervical spine distorsions we found no vascular trauma at all. The osteophytes were here identified as the main risk factor for collateral damage. CONCLUSION: One should look for vascular injuries in case of cervical relevant spine trauma. Moreover,  a rather relevant osteoligamentous injury should be assumed, when cervical vascular trauma was diagnosed. Key words: cervical spine trauma vessel-dissection duplex-sonography CT-angiography.

Ruptured Persistent Trigeminal Artery Causing Direct Cavernous Sinus Fistula Treated with Pipeline Embolization and Minimal Coiling.

BACKGROUND: Rupture of a persistent trigeminal artery associated with development of a cavernous sinus fistula in a traumatic setting is rare. These arteries are typically treated with coil embolization of the cavernous sinus. CASE DESCRIPTION: We present the case of a 42-year-old woman who developed a direct cavernous carotid fistula after a motor vehicle accident. Angiographic imaging revealed a rupture point of a persistent trigeminal artery as it connected with the cavernous segment of the internal carotid artery, causing a cavernous sinus fistula. Coiling of the cavernous sinus was abandoned after placement of 1 coil because of coil herniation into the internal carotid artery. A Pipeline embolization device was placed to oppose the coil against the intima and keep the lumen open. The combination of coil embolization and flow diversion acutely decreased the fistulous flow. Surprisingly, an angiographic follow-up at 6 months showed complete fistula occlusion despite placement of only 1 coil into the cavernous sinus. CONCLUSIONS: We report a rare case where undercoiling of the cavernous sinus occluded a cavernous sinus fistula because of the adjunct use of a Pipeline embolization device in the presence of a traumatic rupture of a persistent trigeminal artery.

Clinical Significance of Wall Changes After Recanalization Therapy in Acute Stroke: High-Resolution Vessel Wall Imaging.

BACKGROUND AND PURPOSE: Owing to the excellent recanalization rate of endovascular treatment, new outcome predictors are required for patients with acute stroke, who have sufficient recanalization. In this study, the effects of recanalization therapy on occluded arteries in patients with acute stroke were investigated using high-resolution vessel wall imaging. METHODS: Twenty-nine patients with stroke were included in the study. High-resolution vessel wall imaging was performed on patients with acute stroke and adequate postrecanalization results. We characterized the postrecanalization arterial wall changes as concentric enhancements and plaques and examined the associations of the postrecanalization changes with procedural factors and neurological outcomes. RESULTS: The most frequent high-resolution vessel wall imaging finding was concentric enhancement, which was associated with thrombectomy procedural factors such as the number of procedures and the type of device. Concentric enhancements were associated with hemorrhagic transformation, whereas plaque was not associated with procedural details. CONCLUSIONS: The use of high-resolution vessel wall imaging after successful recanalization can provide information about postrecanalization arterial wall changes and clinical outcomes.

Short-Burst Bipolar Coagulation for Repairing Partially Damaged Brain Arteries Preserving Their Flow: Technical Note.

OBJECTIVE: Preservation of the integrity of perilesional and intralesional arteries, as well as of perforating vessels, is of utmost importance in microneurosurgery. The purpose of our study was to describe our adaptation of the short-burst bipolar coagulation technique, which was initially introduced by Professor Yasargil, for repairing partially damaged brain arteries. METHODS: When a brain artery is partially and inadvertently damaged during microneurosurgical procedures, microscope magnification is further increased from the high magnification that is routinely used (10-15×) up to 14-17× in order to recognize clearly the injured zone of the vessel. Then the exact bleeding point is identified with a precise suction. Next, bipolar forceps with sharp tips (0.3 mm) are used to seal the wall of the injured artery, closing the borders of the hole between them. A delicate coagulation (20 Malis units, 3 watts) is performed for less than a second according to the so-called "open-close" technique. Short and small bursts of coagulation are used to progressively reduce the size of the defect by cauterization of the surrounding tissue. This gradually diminishes the bleeding up to restore the functional integrity of the vessel wall. RESULTS: The senior author's modification of the Yasargil technique has been used for more than 30 years as a simple and fast method of microsurgical vascular repair of small tears. CONCLUSIONS: The bipolar coagulation represents a safe, clean, fast, and even cheap method for repairing wall defects in fine arteries that are accidently damaged during a microsurgical operation.

Post-traumatic Vertical Gaze Paresis in Nine Patients: Special Vulnerability of the Artery of Percheron in Trauma?

PURPOSE: The purpose was to present a case series of vertical gaze paresis in patients with a history of cranioencephalic trauma (CET). METHODS: The clinical characteristics and management are presented of nine patients with a history of CET secondary to motor vehicle accidents with associated vertical gaze paresis. RESULTS: Neuroimaging studies indicated posttraumatic contusion of the thalamic-mesencephalic region in all nine patients who corresponded to the artery of Percheron region; four patients had signs of hemorrhagic transformation. Vertical gaze paresis was present in all patients, ranging from complete paralysis of the upward and downward gaze to a slight limitation of upward gaze. DISCUSSION: Posttraumatic vertical gaze paresis is a rare phenomenon that can occur in isolation or in association with other neurological deficits and can cause a significant limitation in the quality-of-life. Studies in the literature have postulated that the unique anatomy of the angle of penetration of the thalamoperforating and lenticulostriate arteries makes these vessels more vulnerable to isolated selective damage in certain individuals and can cause-specific patterns of CET.

Risk factors for coil protrusion into the parent artery and associated thrombo-embolic events following unruptured cerebral aneurysm embolization.

OBJECTIVE: Advances in vascular reconstruction devices and coil technologies have made coil embolization a popular and effective strategy for treatment of relatively wide-neck cerebral aneurysms. However, coil protrusion occurs occasionally, and little is known about the frequency, the risk factors and the risk of thrombo-embolic complications. METHOD: We assessed the frequency and the risk factors for coil protrusion in 330 unruptured aneurysm embolization cases, and examined the occurrence of cerebral infarction by diffusion-weighted magnetic resonance imaging (DW-MRI). RESULT: Forty-four instances of coil protrusion were encountered during coil embolization (13.3% of cases), but incidence was reduced to 33 (10% of cases) by balloon press or insertion of the next coil. Coil protrusion occurred more frequently during the last phase of the procedure, and both a wide neck (large fundus to neck ratio) (OR = 1.84, P = 0.03) and an inadequately stable neck frame (OR = 5.49, P = 0.0007) increased protrusion risk. Coil protrusions did not increase the incidence of high-intensity lesions (infarcts) on DW-MRI (33.3% vs 29% of cases with no coil protrusion). However, longer operation time did increase infarct risk (P = 0.0003). Thus, tail or loop type coil protrusion did not increase the risk of thrombo-embolic complications, if adequate blood flow was maintained. CONCLUSION: Coil protrusion tended to occur more frequently in cases of wide-neck aneurysms with loose neck framing. Moderate and less coil protrusion carries no additional thrombo-embolic risk, if blood flow is maintained, which can be aided by additional post-operative antiplatelet therapy.

Inadvertent Detachment of a Retrievable Intracranial Stent: Review of Manufacturer and User Facility Device Experience.

Few systematic surveys have dealt with the potential procedural risks associated with the use of retrievable intracranial stents [Solitaire Flow Restoration (Solitaire FR)], which have become effective tools for recanalizing acutely occluded cerebral arteries. The aim of this study was to present the real-world experiences of Solitaire-FR-related adverse events by reviewing the MAUDE (Manufacturer and User Facility Device Experience) as published on the United States Food and Drug Administration website. In total, 85 adverse events related to the use of the Solitaire FR stent were reported between March 2012 and October 2014. In 80 patients these adverse events were attributable to inadvertent detachment of the device. Thirteen of these 80 patients (16%) died after the procedure. Morbidity data were available in 62 patients, among whom 11 (18%) had suffered a procedure-related injury. Detachment occurred at the first, second, and third pass in nine (21%), 21 (49%), and 13 (30%) of the 43 patients for whom this information was available, respectively. Resistance was perceived by the physician during retrieval of the device in 12 patients, and lesion characteristics were noted in 13. A rescue maneuver was reported in 20 (25%) of the 80 patients in whom the adverse event was attributable to detachment of the device, resulting in flow reestablishment in 13 (65%). The risk of inadvertent detachment during stent retrieval cannot be overemphasized in real-world scenarios, and careful consideration of the "dos and don'ts" is essential for the achievement of a safe procedure.

Arterial injuries after penetrating brain injury in civilians: risk factors on admission head computed tomography.

OBJECT: The object of this study was to determine the specific CT findings of the injury profile in penetrating brain injury (PBI) that are risk factors related to intracranial arterial injuries. METHODS: The authors retrospectively evaluated admission head CTs and accompanying digital subtraction angiography (DSA) studies from patients with penetrating trauma to the head in the period between January 2005 and December 2012. Two authors reviewed the CT images to determine the presence or absence of 30 injury profile variables and quantified selected variables. The CT characteristics in patients with and without arterial injuries were compared using univariate analysis, multivariate analysis, and receiver operating characteristic (ROC) curve analysis to determine the respective risk factors, independent predictors, and optimal threshold values for the continuous variables. RESULTS: Fifty-five patients were eligible for study inclusion. The risk factors for an intracranial arterial injury on univariate analysis were an entry wound over the frontobasal-temporal regions, a bihemispheric wound trajectory, a wound trajectory in proximity to the circle of Willis (COW), a subarachnoid hemorrhage (SAH), a higher SAH score, an intraventricular hemorrhage (IVH), and a higher IVH score. A trajectory in proximity to the COW was the best predictor of injury (OR 6.8 and p = 0.005 for all penetrating brain injuries [PBIs]; OR 13.3 and p = 0.001 for gunshot wounds [GSWs]). Significant quantitative variables were higher SAH and IVH scores. An SAH score of 3 (area under the ROC curve [AUC] for all PBIs 0.72; AUC for GSWs 0.71) and an IVH score of 3 (AUC for all PBIs 0.65; AUC for GSWs 0.65) could be used as threshold values to suggest an arterial injury. CONCLUSIONS: The risk factors identified may help radiologists suggest the possibility of arterial injury and prioritize neurointerventional consultation and potential DSA studies.

Peri-interventional Subarachnoid Hemorrhage During Mechanical Thrombectomy with stent retrievers in Acute Stroke: A Retrospective Case-Control Study.

BACKGROUND: Mechanical thrombectomy with stent retrievers in acute stroke has emerged as a promising new technique with the highest recanalization rate of the therapeutic procedures available so far. However, endovascular treatment is also associated with the risk of specific complications. One of those is the occurrence of peri-interventional subarachnoid hemorrhage (SAH), which has been reported in 5-16 % of the cases. Interestingly, this rate is higher than that of angiographically detectable perforations (0-3 %), leaving the majority of peri-interventional SAH to be due to angiographically occult perforations. Little is known about the influence of this finding on clinical outcome. The purpose of this study was to investigate the clinical relevance of SAH due to occult perforations during thrombectomy with stent retrievers. METHODS: Postinterventional computed tomography (CT) scans of 217 consecutive patients with acute occlusions of intracerebral arteries who were treated with stent retrievers in our department between October 2009 and October 2012 were retrospectively analyzed. RESULTS: SAH was found on postinterventional CT scans in 5.5 % of the cases. Seven cases were included for further analysis and matched to controls by the following characteristics: (1) site of occlusion, (2) result of the recanalization procedure according to the modified thrombolysis in cerebral infarction score, (3) administration of intravenous recombinant tissue plasminogen activator, (4) presence of proximal extracranial occlusion, (5) age, and (6) sex. Comparison of the angiographic data of the two cohorts showed no significant difference in the length of the procedures or the number of maneuvers needed for recanalization, nor were there significant differences in clinical outcomes as measured by NIHSS and mRS scores. Secondary symptomatic ICH occurred in one case in either cohort and led to death in both cases. The rate of asymptomatic ICH within the first 24 h after recanalization was significantly higher in the group with peri-interventional SAH (57 vs. 0 %, P = 0.018). CONCLUSIONS: This small retrospective case-control study did not reveal a significant influence of peri-interventional SAH due to angiographically occult perforations on neurologic outcome of patients treated with stent retrievers.

Fatal avulsion of choroidal or perforating arteries by guidewires. Case reports, ex vivo experiments, potential mechanisms and prevention.

Innovations in endovascular tools have permitted an increasingly broad range of neurovascular lesions to be treated via minimally invasive methods. However, some device modifications may carry additional risks, not immediately apparent to operators. A patient with a symptomatic, partially thrombosed basilar apex aneurysm was allocated balloon-assisted coiling. Attempts were made to place a microwire across the basilar apex through the posterior communicating artery. Overlapping courses of the posterior cerebral and posterior choroidal arteries on the roadmap images were not recognized and a flanged-tip microwire was inadvertently advanced deep into the choroidal artery. Following the wire with a microcatheter led to binding of arterial tissue within the microcatheter. Removing the wire led to an avulsion of the choroidal artery and a severe hemorrhagic complication which proved fatal. Tissue was identified on the tip of the guidewire. Pathology showed layers of vascular tissue within the laser-cut flanges of the distal wire tip. A similar complication, also fatal, occurred during balloon angioplasty of a distal vertebral artery, when an exchange wire was accidently introduced into a perforator from a posterior cerebral artery. Ex vivo catheterization of distal mesenteric arterial branches showed that the wall of small arteries can be entrapped by laser-cut, flanged, but not by smooth guidewire tips. Microwires with a flanged instead of smooth distal tip, when placed into small caliber vessels, may cause hemorrhagic complications from avulsions*.