Kittipong Srivatanakul

Developmental Venous Anomaly: Benign or Not Benign.

Developmental venous anomalies (DVAs), previously called venous angiomas, are the most frequently encountered cerebral vascular malformations. However, DVA is considered to be rather an extreme developmental anatomical variation of medullary veins than true malformation. DVAs are composed of dilated medullary veins converging centripetally into a large collecting venous system that drains into the superficial or deep venous system. Their etiology and mechanism are generally accepted that DVAs result from the focal arrest of the normal parenchymal vein development or occlusion of the medullary veins as a compensatory venous system. DVAs per se are benign and asymptomatic except for under certain unusual conditions. The pathomechanisms of symptomatic DVAs are divided into mechanical, flow-related causes, and idiopathic. However, in cases of DVAs associated with hemorrhage, cavernous malformations (CMs) are most often the cause rather than DVAs themselves. The coexistence of CM and DVA is common. There are some possibilities that DVA affects the formation and clinical course of CM because CM related to DVA is generally located within the drainage territory of DVA and is more aggressive than isolated CM in the literature. Brain parenchymal abnormalities surrounding DVA and cerebral varix have also been reported. These phenomena are considered to be the result of venous hypertension associated with DVAs. With the advance of diagnostic imagings, perfusion study supports this hypothesis demonstrating that some DVAs have venous congestion pattern. Although DVAs should be considered benign and clinically silent, they can have potential venous hypertension and can be vulnerable to hemodynamic changes.

Enlargement of the middle meningeal artery on MR angiography in chronic subdural hematoma

OBJECT The middle meningeal artery (MMA) is suspected to play an important role in the development of chronic subdural hematoma (CSDH). The aim of this study was to clarify whether the MMA was enlarged in patients with CSDHs. METHODS The authors retrospectively assessed 55 patients in whom CSDH was diagnosed between 2010 and 2014 and who underwent MR angiography (MRA) after the onset of CSDH. The authors compared MMA diameters between hemispheres with and without CSDHs on MR angiograms. A case-control study was also performed with 55 sex- and age-matched patients with incidental unruptured aneurysms as controls. RESULTS In 55 patients with CSDHs, the diameters of the 79 MMAs on the CSDH side were significantly larger than the diameters of the 31 MMAs on the non-CSDH side (p < 0.05). In 24 patients with bilateral CSDHs, no significant difference was found between the MMA diameters on the larger hematoma side and those on the smaller hematoma side. In 13 patients who underwent MRA before the onset of the CSDH, the MMAs on MR angiograms acquired after onset of the CSDH were significantly larger than those on MR angiograms acquired before the CSDH onset (p < 0.05). The diameters of the MMAs in 55 patients with CSDHs were significantly larger than those of the MMAs in the 55 control patients (p < 0.05). CONCLUSIONS The MMA is enlarged with development of a CSDH. Information about the MMA observed on MRA in patients with CSDHs may be useful in developing a strategy for future treatment of CSDHs.

Predictors of early vs. late permanent shunt insertion after aneurysmal subarachnoid hemorrhage

Objective: Numerous studies have identified different predictors for secondary hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH), although predictors regarding timing of the shunt operation have never been reported. Predictors for an early shunt, which was defined as a shunt operation performed ≤30 days after SAH onset, and for a late shunt, performed at >40 days, were investigated. Methods: A total of 735 consecutive SAH patients admitted to our hospital between 2003 and 2014 who underwent surgery for ruptured aneurysms within five days of onset were retrospectively assessed. Results: Secondary hydrocephalus developed in 225 patients, including 70 with an early shunt and 96 with a late shunt. Multivariate analysis showed that predictors for secondary hydrocephalus were age ≥70 years, World Federation of Neurosurgical Society (WFNS) grade IV-V, Fisher grade 3–4, intraventricular hemorrhage, anterior cerebral artery aneurysms, and external drainage for acute hydrocephalus (p < 0.05). In the early and late shunt groups, multivariate analysis indicated that early shunt was significantly associated with coil embolization, and late shunt was correlated with middle cerebral artery aneurysms and cerebral infarction due to vasospasm (p < 0.05). Discussion: The difference in the predictors between the early and late shunts implied that the mechanisms of secondary hydrocephalus differed between the early and late shunt groups. Knowledge of the associated risk factors might help to predict the timing of the shunt operation for early rehabilitation planning in the future.

Density of the cerebral cortex in computed tomography angiography source images and clinical outcomes in Grade V subarachnoid hemorrhage

Abstract Objective: Among patients diagnosed with Grade V subarachnoid hemorrhage (SAH) according to the World Federation of Neurosurgical Societies (WFNS), the identification of those with the possibility of recovery is not feasible, although approximately one-fifth of these patients have favorable outcomes according to a recently published series of surgical papers. We hypothesized that computed tomography angiography (CTA) source images (SIs), which have applied to the detection of acute ischemia, might be useful for selecting Grade V patients with possibilities for favorable outcomes. Methods: We retrospectively assessed 170 SAH patients who underwent surgery between January 2009 and February 2012 and quantitatively measured their mean cerebral cortical densities from the initial CTA-SIs. Results: The cortical densities of 123 patients of Grades I–IV were strongly affected by the following two CTA-SI findings that were revealed by multivariate analysis: the density of the internal carotid artery (ICA) just proximal to the petrous portion and the ratio of the subarachnoid (SA) space to intracranial volume (P < 0·05). Favorable outcomes were obtained in 9 of the 47 Grade V patients (19·1%), and the predictors of the favorable outcomes according to multivariate analysis were increased cortical densities on the CTA-SIs and female patients (P < 0·05). Conclusion: The outcomes of Grade V patients could be partly predicted based on the estimates of cortical density from the CTA-SIs, and this measure might be useful for the selection of Grade V patients for surgery, provided that both ICA density and SA space ratio are confirmed before the evaluation of cortical density.

Transvenous embolization of cavernous sinus dural arteriovenous fistula through a thrombosed inferior petrosal sinus utilizing 3D venography

Objective We report a new technique in approaching the cavernous sinus through an occluded inferior petrosal sinus (IPS) using three-dimensional (3D) venography. Case presentation A patient diagnosed with arteriovenous fistula of the right cavernous sinus underwent transvenous embolization. The IPS was not detectable on angiogram. Retrograde injection of contrast with 3D imaging of the internal jugular vein clearly demonstrated the remnant of the IPS. By referring to the images obtained, catheterization of the cavernous sinus by way of the IPS was performed without difficulties. Conclusion Three-dimensional venography for detecting the entrance to the IPS is a useful method and easy to perform. We believe that this technique should be considered whenever the access to an occluded IPS is necessary.

Hemiparesis without Responsible Hematomas in Patients with Subarachnoid Hemorrhage Undergoing Early Aneurysmal Repair

OBJECTIVE The presence of hemiparesis on arrival in patients with subarachnoid hemorrhage (SAH) is presumed to affect prognosis; intracranial hematomas with mass effect responsible for hemiparesis are frequently observed in these patients. The aim of this study was to clarify characteristics and outcomes of patients who presented with hemiparesis on arrival with no responsible hematomas (hemiparesis without hematoma) having mass effect demonstrated on computed tomography. METHODS Consecutive patients with SAH treated with surgery for ruptured cerebral aneurysms within 5 days of onset between 2003 and 2015 were retrospectively reviewed. RESULTS Hemiparesis without hematoma was present in 25 of 858 surgically treated patients (2.9%). Internal carotid artery aneurysms were significantly more common in patients with hemiparesis without hematoma than in the other patients (P < 0.05). In 19 of 21 surviving patients (90.5%) with hemiparesis without hematoma on arrival, the hemiparesis improved at discharge. Favorable outcomes were achieved in 16 of 25 patients with hemiparesis without hematoma (64%) and in 13 of 59 patients with hemiparesis with hematomas (22.0%); this difference was significant (P < 0.05). CONCLUSIONS Hemiparesis can be expected to improve in patients with SAH with hemiparesis without hematoma, and such patients appear to have a better prognosis than patients with SAH with hemiparesis and responsible hematomas. A possible major mechanism of hemiparesis without hematoma based on the characteristics identified is a combination of transient ipsilateral hemispheric functional failure caused by the impact of aneurysmal rupture and transient ischemia of the perforators originating from the internal carotid artery.

Effectiveness of Preradiosurgical Embolization with NBCA for Arteriovenous Malformations - Retrospective Outcome Analysis in a Japanese Registry of 73 Patients (J-REAL study)

Purpose Recent reports have posed doubts about the effect of preradiosurgical embolization in brain arteriovenous malformation (AVM) because it makes the planning of stereotactic radiosurgery (SRS) difficult and has the risk of recanalization out of the target. We investigated whether the performance and quality of embolization may influence the success of SRS based on a retrospective case cohort study. Materials and Methods Seventy-three patients who underwent embolization followed by SRS between 2003 and 2012 in eight institutes with neurointerventionists were considered. They were divided into the following two groups at 3 years of follow up after the final SRS: “successful occlusion group” (S group), with radiologically complete occlusion of AVM; and “non-successful occlusion group” (N group) with persistent remnant nidus or abnormal vascular networks. Patient background, AVM profile, embolization performance grade and complications were compared in each group. The quality of embolization was evaluated with the new grading system: embolization performance grade (E grade), specializing the achievement of nidus embolization. E grade A was defined as sufficient nidus embolization with more than half of the total number of feeders achieving nidus penetration. E grade B was defined as less than half achievement of nidus embolization, and E grade C was defines as failure to perform nidus embolization. Results Forty-three patients were included in the S group, and 29 patients were included in the N group. The size and Spetzler-Martin grade of AVM and the rate of diffuse type was higher in the N group without statistical significance. The embolization performance level according to E grade indicated a significantly higher rate of successful embolization with more than 50% of nidus penetration in the S group (P<0.001). This difference was also confirmed in the subanalysis for limited cases, excluding smaller AVMs with complete occlusion with SRS alone (P=0.001). Conclusion The cause of the unsuccessful result of post-embolization SRS might be the large, diffuse angioarchitecture, but proper embolization with a high rate of nidus penetration to avoid recanalization is more important. Effective embolization is essential to contribute to and promote the effect of radiosurgery.

Endovascular treatment of a dural arteriovenous fistula in a patient with Loeys-Dietz syndrome: A case report

Background Loeys-Dietz syndrome (LDS) is a recently recognized autosomal dominant connective tissue disease. The manifestations of LDS include vascular tortuosity, scoliosis, craniosynostosis, aneurysm and aortic dissections. Clinical presentation A 35-year-old woman treated with Stanford type B aortic dissection and breast cancer was referred to us for Borden type II dural arteriovenous fistula (dAVF) draining to the vein of Galen, involving the midline of tentorium cerebelli. The dAVF was treated successfully by combined transarterial and transvenous embolization. Because of tortuosity of vertebral arteries, a genetic test was conducted confirming LDS type 2. Conclusions To our knowledge, this is the first case report of dAVF associated with LDS. The relationship between LDS and dAVF is unknown but this report shows the possibility that mutation of transforming growth factor β receptors 2 (TGFBR2) related to LDS may be related to shunt diseases. Because intervention in LDS seems to be feasible compared to Ehlers Danlos syndrome and Marfan syndrome, it is important to make the correct diagnosis.