Radiological Features and Management of Intracranial Aneurysms Associated With Moyamoya Disease: A Case Series of Single-Center Experience.

Background Moyamoya disease (MMD) can be a major cause of hemorrhagic stroke. Though extensive angiographic studies have been undertaken, the understanding of the association between aneurysms and MMD remains unanswered. In this study, we explore the association of the aneurysm with MMD and its management. We have also reviewed such associations described in the literature and how the present cases differ from those previously described. Materials and methods The clinical and radiologic data of moyamoya disease cases were accessed from medical and radiological records between January 2010 and July 2017. Two neuroradiologists independently analyzed the data and imaging details. Results Out of 103 patients with MMD, eight patients (7.77%) had associated intracranial aneurysms with eleven aneurysms. Out of the 11 aneurysms, five were the tip of the basilar artery aneurysms and were the most common location for aneurysm (45.5%), followed by lenticulostriate artery, PCA perforator, and distal ACA (DACA) in the P1 PCA, P2 PCA, and P3 PCA artery aneurysms. Out of eight patients, five (62.5%) had a hemorrhage on a non-contrast computed tomography (NCCT) scan of the brain, whereas three (37.5%) had an ischemic presentation. Out of 11 aneurysms, seven aneurysms, including three basilar tip aneurysms (unruptured) and one PCA perforator (ruptured), and three saccular PCA (P1, P2, and P3) (ruptured) were treated by endovascular coiling. Follow-up angiography showed stable aneurysmal occlusion except in one basilar tip, where recurrence was observed. Conclusions MMD-intracranial aneurysm is commonly observed in patients with intracranial hemorrhage and carries a higher risk of rupture. Therefore, identification of the aneurysm is essential for management. Endovascular treatment, either with coil or glue embolization, can be a safe and effective treatment method for such aneurysms with long-term good results.

Effect of Age, Stage, and Type of Surgical Revascularization on Clinical and Angiographic Outcome in Moyamoya Disease - Experience from a Case Series of 175 Revascularization Procedures.

Background: There is dearth of literature on impact of age - pediatric versus adult, Suzuki staging - early versus late, and revascularization type - indirect versus direct on clinical and angiographic outcome in moyamoya disease (MMD). Hence, we intend to comprehensively evaluate factors influencing outcome in MMD following surgical revascularization. Methods: MMD patients operated at our institute from January 2011 to August 2018 were followed for an average 24 months. Primary outcomes were modified Rankin score (mRS) and stroke risk reduction. Secondary outcome was angiographic outcome score (AOS). Results: A total of 133 patients including 37.6% adults (>18 years; n = 50) underwent 175 revascularizations - 89 direct (DR) and 86 indirect (IR) subgroups. Mean mRS scores improved in pediatric DR (P < 0.001), IR (P < 0.001), adult IR (P = 0.10), and DR (P = 0.25) subgroups. Recurrent stroke rate was similar in pediatric-DR (2.7%) and IR (7.6%, P = 0.61), and adult-DR (0%) and IR (4.1%) subgroups (P = 1.00). AOS scores improved in pediatric DR (P = 0.002) and IR (P = 0.01), and adult-DR (P = 0.02) and IR (P = 0.06) subgroups. Late-stage MMD (Suzuki IV-VI) showed better improvement in mRS scores than early-stage-Suzuki (I-III; P < 0.001). Recurrent stroke rates were similar (P = 0.26) and AOS scores improved significantly in early- and late-stage MMD (P < 0.001). Conclusions: In pediatrics, clinical and angiographic outcome significantly improved after revascularization procedure, and in adults, angiographic improvement was more evident than clinical recovery. Late-stage Suzuki MMD patients demonstrated significantly better clinical improvement than early stage. The angiographic improvement was equivalent to early stage, irrespective of age and type of revascularization.

Morphometric Analysis of C2 Pedicle in 247 Patients and Proposal for Trajectory and Size of Pedicle Screw.

BACKGROUND: Screw diameters are currently available based on the literature available for the Western population. No data are available in such a large number of patients for the Indian population. OBJECTIVE: The aim of this study was to define the average pedicle size available and to determine the angulation for placement of screws for C2 pedicle in the Indian population. We also try to determine the pedicle screw diameter which can be used universally in most Indian patients, considering the pedicle dimensions. MATERIAL AND METHODS: Retrospective morphometric analysis of CT scans of 247 patients (152 M, 95 F) was done to calculate the C2 pedicle width (PW), pedicle height (PH), pedicle length (PL), pedicle transverse angle (PTA) and the craniocaudal angulation (CCA) of the C2 pedicle. RESULTS: Mean PW in females was 5.3 mm and in males it was 5.9 mm. This difference was statistically significant. The mean PH in the study population was 8.9 mm, while the mean PL was 29.7 mm. The mean PTA was 40.0 degrees and the CCA was 28.4 degrees. CONCLUSION: This is a morphometric analysis of the C2 pedicle which provides information for the surgeons to determine the safe site of entry and trajectory for the screw implantation. We conclude that a screw diameter of 2.7 mm can be safely implanted in a vast majority of the patient population.

Feasibility of Double Anterior Odontoid Screw: A CT-Based Morphometric Analysis of the Axis in Adult Indian Population.

BACKGROUND: The fractures of the odontoid process constitute 10% of all cervical spine injuries. Odontoid screw placement, although technically challenging, in indicated cases is the ideal treatment. Hence, a thorough knowledge of the odontoid dimensions is necessary prior to the surgical endeavor, more so for planning double odontoid screws. MATERIALS AND METHODS: A prospective morphometric analysis of retrospective data of 250 patients was acquired at our institute using Somatom Definition edge 128 slice 64-row detector Siemens CT scanner. The dimensions of the odontoid process were measured at the waist (narrowest portion), widest diameter both in anteroposterior and transverse diameters. The dimensions of the C2 vertebra were measured at the level of the superior and inferior endplate in both the planes. RESULTS: A total of 250 patients were evaluated with age ranging from 1 to 80 years. Males constituted 174 (69.6%) and 76 (30.4%) were females. The mean transverse diameter (TD) at the odontoid waist (narrowest diameter) was 8.66 mm. The mean TD at the widest point of odontoid was 9.68 mm. Mean anteroposterior (AP) diameter 2.5 mm away from the midline on the left side at the level of the waist was 9.51 mm and 2.5 mm on the right of midline was 9.01 mm. The mean AP diameter at the C2 base was 15.824 mm in males and 14.833 mm in females (P < 0.001). CONCLUSION: Double odontoid screw insertion is feasible in only 36% of Indians in the transverse plane, whereas 98.4% of the odontoids can accommodate double screws in the sagittal plane.

Proposal of a New Safety Margin for Placement of C2 Pedicle Screws on Computed Tomography Angiography.

BACKGROUND: Screw diameters currently available are based on the literature available. No data are available for the safety margin available for C2 pedicle screw placement. The objective of this study was to define the average pedicle size available for placing C2 pedicle screws and to quantify the safety margin available in case of lateral breach of screw. METHODS: Computed tomography angiograms of 259 patients (161 men, 98 women) were analyzed to calculate the C2 pedicle width, the area of the transverse foramen (TF) and the vertebral artery (VA), and the occupation ratio (OR) of the VA within the TF. The VA was classified into groups based on its lie within the TF (anteromedial, anterolateral, posteromedial, posterolateral, central, ectatic). The distance which the pedicle screw can breach without encountering the VA was calculated (lateral pedicle to vertebral artery distance [LPVA]). The diameters of the VA and the TF were estimated, and their difference gives the safety margin in case of breach of the lateral cortex of the C2 pedicle. RESULTS: The mean mediolateral diameter of the pedicle isthmus, perpendicular to the pedicle axis, in women was 5.3 mm and in men it was 5.8 mm. This difference was statistically significant. In 53.9% (122/226) of patients, the VA was dominant on the left side. The overall mean OR at the C2 vertebral level was found to be 37.3%. The mean LPVA was 0.9 mm, and the average overall safety margin available was 2.5 mm (range, 0.4-5.3 mm). CONCLUSIONS: This study describes the relationship of the VA in the C2 TF and the relative risk during pedicle screw fixation.