Sphenoparietal Sinus Research Articles

Arteriovenous malformation with unique drainage through the emissary vein of the foramen ovale: illustrative case.

As part of the laterotrigeminal venous system (LTVS), the emissary vein of the foramen ovale (EVFO) is an underrecognized venous structure communicating between the cavernous sinus and pterygoid plexus. The sphenobasal sinus is an anatomical variation of the sphenoparietal sinus that drains directly into the EVFO. The authors present the case of a ruptured arteriovenous malformation (AVM) with a unique drainage pattern through the sphenobasal sinus and EVFO. A 9-year-old female initially presented with loss of consciousness and was subsequently found to have a ruptured AVM in the left basal frontal area. She underwent an immediate decompressive hemicraniectomy, with a computed tomography angiogram demonstrating a unique anatomical variation in which the sphenobasal sinus communicated with the EVFO and LTVS. The final venous drainage returned to the pterygoid plexus and external jugular vein. Postoperatively, the patient made a substantial recovery, with generalized right-sided weakness remaining as the sole deficit. The authors present the case of a ruptured AVM with unique venous drainage into the sphenobasal sinus and EVFO, for which the current literature remains limited. As exemplified by this illustrative case, technique modification may be warranted in the setting of this unique anatomical variation to avoid venous sinus injury.

Synchronous Superficial Middle Cerebral Vein Outflow Correlates Favorable Tissue Fate After Mechanical Thrombectomy for Acute Ischemic Stroke

The purpose of this study was to determine the association between hemispheric synchrony in venous outflow at baseline and tissue fate after mechanical thrombectomy (MT) for acute ischemic stroke (AIS). A two-center retrospective analysis involving AIS patients who underwent MT was performed. The four cortical veins of interest include the superficial middle cerebral vein (SMCV), sphenoparietal sinus (SS), vein of Labbé (VOL), and vein of Trolard (VOT). Baseline computed tomography perfusion data were used to compare the following outflow parameters between the hemispheres: first filling time (△FFT), time to peak (△TTP) and total filling time (△TFT). Synchronous venous outflow was defined as △FFT=0. Multivariable regression analyses were performed to evaluate the association of venous outflow synchrony with penumbral salvage, infarct growth, and intracranial hemorrhage (ICH) after MT. A total of 151 patients (71.4±13.2 years, 65.6% women) were evaluated. Patients with synchronous SMCV outflow demonstrated significantly greater penumbral salvage (41.3 mL vs. 33.1 mL, P=0.005) and lower infarct growth (9.0 mL vs. 14.4 mL, P=0.015) compared to those with delayed SMCV outflow. Higher △FFTSMCV (β=-1.44, P=0.013) and △TTPSMCV (β=-0.996, P=0.003) significantly associated with lower penumbral salvage, while higher △FFTSMCV significantly associated with larger infarct growth (β=1.09, P=0.005) and increased risk of ICH (odds ratio [OR]=1.519, P=0.047). Synchronous SMCV outflow is an independent predictor of favorable tissue outcome and low ICH risk, and thereby carries the potential as an auxiliary radiological marker aiding the treatment planning of AIS patients.

High-Flow Indirect Carotid-Cavernous Fistula with Transarterial and Transvenous Endovascular Treatment

Male, 39 years old, with a progressive headache for seven months, progressive right exophthalmos, right chemosis and conjunctival edema, pulsatile tinnitus and carotid bruit in the right frontotemporal region. Cerebral magnetic nuclear angioresonance showed multiple anomalous vascular structures near the sphenoparietal sinus, pterygoid plexus, superior and inferior orbital fissures, all on the right, with swelling of the basilar plexus. A diagnostic cerebral and cervical arteriography was performed, which showed a high-output indirect Carotid-Cavernous Fistula (CCF), nourished mainly by multiple dysplastic dural branches originating from the mandibular and pterygopalatine segments of the internal maxillary artery and secondarily by the inferolateral trunk. There was hypertensive venous drainage anteriorly through the ecstatic superior and inferior ophthalmic veins, corresponding angular and facial veins, and posteriorly to both cavernous sinuses, basilar plexus, superior petrosal sinuses, and internal jugular veins (Type D, Barrow Classification). The patient underwent arterial embolization with hystoacril and lipiodol in branches of the right internal maxillary artery and venous embolization with platinum micro coils with occlusion of the fistula. He evolved well with the improvement of symptoms, being discharged from the hospital and scheduled for outpatient follow-up.

Sphenoparietal Sinus Transposition: Operative Technique for Optimizing Pretemporal Posterior Circulation Access While Preserving the Sylvian Venous Complex

Transsylvian approaches are a cornerstone of complex cranial operations, with wide applicability across cerebrovascular, skull base, and neuro-oncology operations. Deep lesions, especially those involving the basilar apex, midbrain, or interpeduncular fossa, require wide exposures that may be inhibited by the presence of a large complex of superficial sylvian veins (SSV) draining into the sphenoparietal sinus. This report describes technical and clinical aspects of the sphenoparietal sinus transposition (SPST) technique. Technical case report of the SPST technique, including a step-by-step neuroanatomic description, overview of common indications, clinical pearls and pitfalls, and illustrative case examples. Once the benefits of proceeding with SPST have been established, the maneuver is initiated with 2 stepwise dural incisions: an incision from lateral to medial along the lateral margin of the lesser sphenoid wing, followed by an orthogonal cut across the temporal pole down the middle fossa floor. The pretemporal dura is peeled off the lateral wall of the cavernous sinus, allowing mobilization of the SSV complex and temporal pole posteriorly without disrupting or straining the connection point at the sphenoparietal sinus. Illustrative case examples include a clip reconstruction of a basilar apex aneurysm for which earlier endovascular treatment had failed and microsurgical resection of a peduncular cavernous malformation. SPST is a simple but versatile technique with important applications in complex cranial surgery. By mobilizing the SSV complex together with its dural attachment, the transsylvian corridor can be markedly widened, allowing access to the basilar apex region and ventral midbrain.

Stroke recurrence is associated with unfavorable intracranial venous outflow in patients with symptomatic intracranial atherosclerotic large vessel severe stenosis or occlusion.

The purpose of this study was to investigate the predictive value of intracranial venous outflow for recurrent cerebral ischemic events (RCIE) in patients with symptomatic intracranial atherosclerotic large-vessel severe stenosis or occlusion (sICAS-S/O). This retrospective study included sICAS-S/O patients with anterior circulation who underwent dynamic computed tomography angiography (dCTA) and computed tomography perfusion (CTP). Arterial collaterals were evaluated using the pial arterial filling score for dCTA data, tissue-level collaterals (TLC) were assessed using the high-perfusion intensity ratio (HIR, Tmax >10 s/Tmax >6 s), and cortical veins were evaluated using the multi-phase venous score (MVS) for the vein of Labbé (VOL), sphenoparietal sinus (SPS), and superficial cerebral middle vein (SCMV). The relationships between multi-phase venous outflow (mVO), TLC, and 1-year RCIE were analyzed. Ninety-nine patients were included, 37 of whom had unfavorable mVO (mVO-) and 62 of whom had favorable mVO (mVO+). Compared with the mVO+ patients, mVO- patients had a higher admission National Institutes of Health Stroke Scale (NIHSS) score (median, 4 [interquartile range (IQR), 0-9] vs. 1 [IQR, 0-4]; p = 0.048), larger ischemic volume (median, 74.3 [IQR, 10.1-177.9] vs. 20.9 [IQR, 5-86.4] mL; p = 0.042), and worse tissue perfusion (median, 0.04 [IQR, 0-0.17] vs. 0 [IQR, 0-0.03]; p = 0.007). Multivariate regression analysis showed that mVO- was an independent predictor of 1-year RCIE. For patients with sICAS-S/O of the anterior circulation, unfavorable intracranial venous outflow is a potential imaging indicator for predicting higher 1-year RCIE risk.

The Sphenoparietal Sinus Revisited: Anatomical and Histological Study With Application to Interventional Procedures and Skull Base Surgery.

Background The sphenoparietal sinus (SPS) is implicated in various clinical pathologies, specifically arteriovenous fistulasand venous sinus thrombosis. This study is aimed to better understand this venous structure of the skull base via histological examination. Methods Ten embalmed and latex-injected adult body donors' heads (20 sides)underwent microdissection of the SPSusing a surgical microscope. The entire dura on the underside of the lesser wing of the sphenoid bone encompassing the region known as the groove for the SPS was harvested from each body donor and submitted for histological analysis (H&E, Periodic acid-Schiff [PAS], Masson's Trichrome). Five leftand five right transverse sinuses were harvested and analyzed histologically as controls. Results A definitive SPS was identified in 14/20 (70%) of the latex-injected body donors. When present, the sinuses were classified as small, medium, or large. Tributaries included the middle meningeal veins, superficial Sylvian vein, and anterior temporal veins. All sinuses drained medially into the cavernous sinus. For the body donors analyzed histologically, 17 (85%) were consistent with a dural venous sinus and not a vein and were observed to have a rich nerve and arterial supply within their walls. The histological findings of the SPS were similar to those seen for the transverse sinus. The combined prevalence for the SPS in gross and histological body donors was 78%. Conclusions Our findings support the presence ofSPS in the majority of body donors. To our knowledge, this is the first histological study of the SPS.

Surgical Strategy in Modification of the Transpetrosal Approach to Avoid Postoperative Venous Complications: A Report of 74 Consecutive Cases.

The transpetrosal approach is a complex skull base procedure with a high risk of complications, particularly caused by injury of the venous system. It is in part related to variability of blood outflow pathways and their distinctive patterns in each individual patient. To evaluate outcomes and complications after skull base surgery with use of the petrosal approach modifications, which selection was based on the detailed preoperative assessment of venous drainage patterns. Overall, 74 patients, who underwent surgery via the transpetrosal approach at our institution between 2000 and 2017, were included in this study. In all cases, the venous drainage pattern was assessed preoperatively and categorized according to the predominant blood outflow pathway into four types as previously suggested by Hacker: (1) sphenoparietal sinus (SpPrt), (2) sphenobasal vein (SpB), (3) sphenopetrosal sinus (SpPS), and (4) cortical. The blood outflow through the bridging petrosal vein and the vein of Labbé was also taken into consideration. In patients with SpPrt- and a cortical-type venous drainage, the transpetrosal approach was used in a standard way. In patients with SpB-type venous drainage, limited extradural anterior petrosectomy was combined with intradural anterior petrosectomy after dural opening, superior petrosal sinus transection, tentorial cutting, Meckel's cave opening, and trigeminal nerve mobilization. In patients with SpPS-type venous drainage, after standard petrosectomy, dural opening, and tentorial cutting, SpPS ligation was done followed by 2-week interval before staged definitive tumor resection. Gross total, near-total, and subtotal resection of the lesion (meningioma, 48 cases; retrochiasmatic craniopharyngioma, 11 cases; brain stem cavernoma, 7 cases; other tumors, 8 cases) was achieved in 30 (40.5%), 24 (32.4%), and 20 (27.0%) patients, respectively. Postoperative complications that were possibly related to venous compromise were noted in 18 patients (24.3%), but neither one was major. Of these 18 patients, 9 were symptomatic, but all symptoms-aphasia (4 cases), seizures (2 cases), and confusion (3 cases)-fully resolved after conservative treatment. Overall, 13 patients, including 4 symptomatic, had signal changes on T2-weighted brain MRI, which were permanent only in 3 cases (all asymptomatic). Our suggested surgical strategy can be applied to any type of the venous drainage pattern. Preoperative evaluation and intraoperative preservation of the blood outflow pathways are crucial means for safe and effective application of the transpetrosal approach.

Intravenous tPA (Tissue-Type Plasminogen Activator) Correlates With Favorable Venous Outflow Profiles in Acute Ischemic Stroke.

Intravenous tPA (tissue-type plasminogen activator) is often administered before endovascular thrombectomy (EVT). Recent studies have questioned whether tPA is necessary given the high rates of arterial recanalization achieved by EVT, but whether tPA impacts venous outflow (VO) is unknown. We investigated whether tPA improves VO profiles on baseline computed tomography (CT) angiography (CTA) images before EVT. Retrospective multicenter cohort study of patients with acute ischemic stroke due to large vessel occlusion undergoing EVT triage. Included patients underwent CT, CTA, and CT perfusion before EVT. VO profiles were determined by opacification of the vein of Labbé, sphenoparietal sinus, and superficial middle cerebral vein on CTA as 0, not visible; 1, moderate opacification; and 2, full. Pial arterial collaterals were graded on CTA, and tissue-level collaterals were assessed on CT perfusion using the hypoperfusion intensity ratio. Clinical and demographic data were determined from the electronic medical record. Using multivariable regression analysis, we determined the correlation between tPA administration and favorable VO profiles. Seven hundred seventeen patients met inclusion criteria. Three hundred sixty-five patients received tPA (tPA+), while 352 patients were not treated with tPA (tPA-). Fewer tPA+ patients had atrial fibrillation (n=128 [35%] versus n=156 [44%]; P=0.012) and anticoagulants/antiplatelet treatment before acute ischemic stroke due to large vessel occlusion onset (n=130 [36%] versus n=178 [52%]; P<0.001) compared with tPA- patients. One hundred eighty-five patients (51%) in the tPA+ and 100 patients (28%) in the tPA- group exhibited favorable VO (P<0.001). Multivariable regression analysis showed that tPA administration was a strong independent predictor of favorable VO profiles (OR, 2.6 [95% CI, 1.7-4.0]; P<0.001) after control for favorable pial arterial CTA collaterals, favorable tissue-level collaterals on CT perfusion, age, presentation National Institutes of Health Stroke Scale, antiplatelet/anticoagulant treatment, history of atrial fibrillation and time from symptom onset to imaging. In patients with acute ischemic stroke due to large vessel occlusion undergoing thrombectomy triage, tPA administration was strongly associated with the presence of favorable VO profiles.

Sphenoparietal Sinus Dural Arteriovenous Fistulas: A Series of 10 Patients.

Dural arteriovenous fistulas (DAVFs) of the sphenoparietal sinus or sphenoid wing region are uncommon lesions with unique and interesting angioarchitecture. Understanding appropriate anatomy and recognizing patterns provide important treatment implications. To describe a single surgeon's experience with open surgical treatment of sphenoparietal sinus DAVFs, the surgical indications for this uncommon lesion, and the microsurgical techniques related to its treatment and to review the literature on its surgical treatment. Consecutive cases of sphenoparietal sinus DAVF treatment conducted by a single surgeon over 24 years (1997-2020) were retrospectively reviewed. Published reports of similar cases were reviewed. Of 202 surgically treated DAVFs, 10 lesions in 10 patients were sphenoparietal sinus DAVFs. Four patients presented with intracranial hemorrhage, 3 with headache, and 2 with pulsatile tinnitus; 1 patient was incidentally identified as having a DAVF during treatment for a ruptured aneurysm. Most patients (7 of 10) had undergone endovascular embolization previously. Nine patients had Borden type III DAVFs and one had a Borden type II fistula. Surgery in all 10 patients resulted in angiographically confirmed fistula obliteration. Clinical outcomes at the last follow-up, measured by a modified Rankin Scale (mRS) score, were excellent in 6 patients (mRS ≤ 2) and poor in 1 patient (mRS ≥ 3); late outcomes were not available for 3 patients. Sphenoparietal sinus DAVFs are an uncommon anatomic subtype. Careful attention to angiographic detail leads to identification of the site of venous interruption and results in a high rate of surgical cure with excellent clinical outcomes.

Time-resolved assessment of cortical venous drainage on multiphase CT angiography in patients with acute ischemic stroke.

Cortical vein opacification is not routinely assessed in patients presenting with acute ischemic stroke (AIS), and the value of temporal assessment of venous outflow is not known. We evaluated the utility of assessing cortical venous drainage over time using multiphase CT angiography (mCTA). Cortical venous drainage was assessed in patients from the Precise and Rapid Assessment of Collaterals Using Multi-Phase CTA in the Triage of Patients With Acute Ischemic Stroke for IA Therapy prospective multicenter cohort study of patients with symptoms of AIS with ICA and/or middle cerebral artery occlusion on baseline mCTA. Opacification of vein of Labbe, sphenoparietal sinus, superficial middle cerebral vein, and vein of Trolard of the affected hemisphere was graded as no (0), partial (1), or full (2) opacification in each mCTA phase. The venous opacification scores for each phase were added to generate a total venous score (TVS) (range 0-24). Primary outcome was 90-day modified Rankin score. Repeated measures analysis was used to assess the effect of phase timing on venous score on outcome. Of 432 patients, 284 (65.7%) had proximal arterial occlusions. Median venous opacification score per phase (range 0-8) was 3 (IQR 1-6) in the first phase and increased in the second and third phases [median (IQR): 6 (5-8) and 8 (6-8), respectively] of the mCTA. In a multivariable analysis adjusting for age, baseline National Institutes of Health Stroke Scale, and Albertastrokeprogram early CT score, a significant association between TVS and 90-day mRS was noted ([adjusted cOR for TVS 6-11: 0.16 (95% CI 0.05-0.51); TVS 12-17: 0.18 (95% CI 0.06-0.57); TVS 18-24: 0.20 (0.06-0.63)]. Repeated measures analysis of venous scores from all three phases showed a significant effect of time/phase on TVS (p < 0.001). This study concludes that venous opacification over time on multiphase CTA is associated with 90-day clinical outcome. There was however no added benefit of venous scoring vis-a-vis arterial collateral assessment in predicting outcome.

Sphenoparietal sinus and superficial middle cerebral vein thrombosis: A case report and review of literature

BackgroundCerebral venous sinus thrombosis is rare and might be overlooked by healthcare providers. It often occurs in the transverse sinuses, superior sagittal sinus, and the vein of Trolard. Sphenoparietal sinus (SPS) and/or superficial middle cerebral vein (SMCV) thrombosis is rare and only 12 cases reported in the literature. Case descriptionWe report a 47-year-old woman with iron deficiency anemia associated with myoma uteri who developed left SPS and SMCV thrombosis. She presented with sudden unconsciousness, right hemiplegia, and aphasia. Brain computed tomography showed subcortical hemorrhages in the left frontal and temporal lobes. Magnetic resonance imaging did not reveal the cause of the bleeding. Although antihypertensive treatment with nicardipine was initiated, she deteriorated into coma the next day and underwent emergency decompressive craniectomy. Thrombosis of the SMCV was identified during surgery. Re-examination of preoperative T2 star-weighted imaging revealed thrombosis of the SPS and SMCV. ConclusionAll but one of the reviewed cases had the thrombosis develop on the left side, which may be attributed to anatomical and brain functional laterality. When an edematous change or cortical hemorrhage of unknown cause is encountered within the perisylvian region, especially on the left side, the possibility of SPS and SMCV thrombosis should be considered.

Posterior Transposition of the Frontal Bridging Veins Together with Sphenoparietal Sinus: A Simple Technique to Widen the Surgical Corridor During Pterional Clipping of the Anterior Communicating Artery

High-positioned and/or superoposteriorly directed anterior communicating artery aneurysms can be treated by direct clipping using the pterional (fronto-temporo-sphenoidal) approach. This procedure, however, requires stronger retraction of the frontal lobe. Hence, preservation of the prominent frontal bridging veins (FBVs) draining into the sphenoparietal sinus (SPS) remains a significant challenge in preventing postoperative venous congestion. We developed a technique to release the tension on the FBVs by pulling them together with the SPS epidurally. In 2 patients, who had presented with high-positioned and/or superoposteriorly directed anterior communicating artery aneurysms, we peeled off the arachnoid surrounding the FBVs and detached it from the brain surface. We further released the veins by moving them posteriorly, together with the SPS epidurally. Using this technique, we established a wide corridor through a more lateral transsylvian trajectory with effective posterior retraction of the frontal lobe and were successful in clipping and obliterating the aneurysms. Open clipping of unruptured intracranial aneurysms requires accuracy to preserve higher brain function. Our technique was successful in both patients, and preserving the FBVs could be useful in the treatment of such aneurysms.

Favorable Venous Outflow Profiles Correlate With Favorable Tissue-Level Collaterals and Clinical Outcome

Patients with acute ischemic stroke due to large vessel occlusion and favorable tissue-level collaterals (TLCs) likely have robust cortical venous outflow (VO). We hypothesized that favorable VO predicts robust TLC and good clinical outcomes. Multicenter retrospective cohort study of consecutive acute ischemic stroke due to large vessel occlusion patients who underwent thrombectomy triage. Included patients had interpretable prethrombectomy computed tomography, computed tomography angiography, and cerebral perfusion imaging. TLCs were measured on cerebral perfusion studies using the hypoperfusion intensity ratio (volume ratio of brain tissue with [Tmax >10 s/Tmax >6 s]). VO was determined by opacification of the vein of Labbé, sphenoparietal sinus, and superficial middle cerebral vein on computed tomography angiography as 0, not visible; 1, moderate opacification; and 2, full. Clinical and demographic data were determined from the electronic medical record. Using multivariable regression analyses, we determined the association between VO and (1) favorable TLC status (defined as hypoperfusion intensity ratio ≤0.4) and (2) good functional outcome (modified Rankin Scale score, 0-2). Six hundred forty-nine patients met inclusion criteria. Patients with favorable VO were younger (median age, 72 [interquartile range (IQR), 62-80] versus 77 [IQR, 66-84] years), had a lower baseline National Institutes of Health Stroke Scale (median, 12 [IQR, 7-17] versus 19 [IQR, 13-20]), and had a higher Alberta Stroke Program Early Computed Tomography Score (median, 9 [IQR, 7-10] versus 7 [IQR, 6-9]). Favorable VO strongly predicted favorable TLC (odds ratio, 4.5 [95% CI, 3.1-6.5]; P<0.001) in an adjusted regression analysis. Favorable VO also predicted good clinical outcome (odds ratio, 10 [95% CI, 6.2-16.0]; P<0.001), while controlling for favorable TLC, age, glucose, baseline National Institutes of Health Stroke Scale, and good vessel reperfusion status. In this selective retrospective cohort study of acute ischemic stroke due to large vessel occlusion patients undergoing thrombectomy triage, favorable VO profiles correlated with favorable TLC and were associated with good functional outcomes after treatment. Future prospective studies should independently validate our findings.

Calvarial diploic venous channels: delineation with maximal intensity projection technique.

To date, very few studies have explored the three-dimensional architecture of calvarial diploic venous channels (CDVCs). This study aimed to characterize the three-dimensional architecture of CDVCs using maximum intensity projection (MIP) images based on contrast-enhanced magnetic resonance imaging (MRI). A total of 77 patients with intact calvarial hemispheres and underlying dura mater and dural sinuses underwent contrast-enhanced MRI. Among them, we extracted the data of 49 with at least a part of the major CDVC pathways identified on the MIP images for analysis. On serial contrast-enhanced MRI images, the CDVCs were commonly detected as curvilinear structures with inhomogeneous diameters and tributaries, while the MIP images delineated the three-dimensional architecture of the developed CDVC pathways. More than such CDVC pathway was entirely delineated on the right in 67.3% and on the left in 71.4%, most frequently in the frontal and temporal regions, with their connecting sites to the sphenoparietal and superior sagittal sinuses. The morphology, distribution, and course of the identified CDVCs were highly variable. In 55.1%, the CDVCs formed fenestrations that were variable in size, shape, and number. The developed CDVC pathways may be characterized by morphological variability and fenestrations. Thin-sliced, contrast-enhanced MRI is useful to depict diploic veins, while MIP images allow for better appreciation of the entire course of the developed CDVC pathways. Traumatic and intraoperative disconnection between the dura mater overlying the dural sinuses and the adjacent inner table of the skull can cause epidural venous bleeding.

Bilateral spontaneous carotid-cavernous fistulae

A man in his late fifties had right-sided retro-orbital pain and diplopia for 1 month. There was no preceding head trauma. On examination, he had a right abducens palsy with...

A giant spontaneous dural arteriovenous fistula of the spheno-parietal sinus clinically masquerading as carotico-cavernous fistula: A case report

Dural arteriovenous fistulas (DAVF) are abnormal connections between the feeding arteries and veins within the dural leaflets and constitute 10%–15% of all intracranial arteriovenous malformations. DAVF draining into sphenoparietal sinus is a rare pathologic entity that is fed by the middle meningeal artery and is associated with a history of prior trauma. We report a unique case of DAVF of sphenoparietal sinus that had developed spontaneously. Being giant in morphology, it had eroded into the orbit and presented with proptosis, chemosis and restriction of eye movement. Although the clinical findings pointed towards caroticocavernous fistula, the real pathomorphology was unveiled by the six-vessel catheter angiography with selective catheterisation of smaller feeding vessels. All the feeding vessels were meticulously mapped out, and the fistulous connection was vividly identified and subsequently obliterated using detachable coils and n-butyl cyanoacrylate.

Normal Variant Vein in the Deep Sylvian Fissure (Common Vertical Trunk) Increases the Risk of Ischemic Complication after Clipping Middle Cerebral Artery Aneurysm with Short M1

Middle cerebral artery aneurysms (MCANs) associated with short M1 located in the limen insulae tend to have poor outcomes after surgical clipping due to brain contusions and ischemic complications. However, the effect of veins in the deep Sylvian fissure is unclear. The normal variant of the insular veins and deep middle cerebral vein, which runs anteriorly near the limen and drains into the sphenoparietal sinus, is known as the common vertical trunk (CVT). We retrospectively examined whether the presence of a CVT increased surgical complications after clipping of short M1 aneurysms in 164 cases of unruptured MCANs (153 patients) clipped by the same surgeon. The 21 aneurysms located proximal to the limen insulae were defined as short M1 aneurysms. The 164 patients were divided into a short M1 group (n=21) and a non-short M1 group (n=143). The short M1 group was further divided into a CVT group (n=6) and a non-CVT group (n=15). The short M1 group showed a significantly (p＜0.001) longer operative time and higher rates of lacunar infarction and symptomatic (modified Rankin score ≥1) infarction than the non-short M1 group. The CVT group had higher rates of lacunar infarction and symptomatic infarction (50.0% and 16.7%, respectively) than the non-CVT group (26.7% and 6.7%, respectively). The CVT obstructed the view of the aneurysm neck behind the CVT, where the lenticulostriate arteries were located. The presence of a CVT in cases of short M1 aneurysms may be a risk factor for ischemic complications after clipping surgery.

Spontaneous Thrombosis of a Middle Meningeal Arteriovenous Fistula With Subsequent Pseudoaneurysm Formation: Case Report and Review of Literature

ABSTRACT BACKGROUND AND IMPORTANCE Middle meningeal artery (MMA) pseudoaneurysms and middle meningeal arteriovenous fistulas (MMAVFs) are rarely reported after head injury. We report an unusual case of delayed MMA pseudoaneurysm formation after spontaneous thrombosis of an MMAVF, and review existing literature on MMAVF treatment and results. CLINICAL PRESENTATION A 59-yr-old male presented with a 5-d history of worsening left-sided headaches, followed by nausea, lethargy, and difficulty with speech. Non-contrast computed tomography demonstrated a left temporal intraparenchymal hemorrhage (IPH) and an acute left-sided subdural hematoma (SDH). Cerebral angiography found abnormal shunting between the right MMA and the right sphenoparietal sinus, consistent with an MMAVF. During the course of admission, the patient's neurological condition deteriorated requiring craniotomy for evacuation of SDH and IPH. Given the presumed incidental nature of the contralateral MMAVF, conservative management was recommended. Follow-up imaging 2 mo after surgery revealed spontaneous thrombosis of the right MMAV. Repeat imaging 5 mo later revealed an MMA pseudoaneurysm at the prior fistulous site, which was subsequently embolized with Onyx, occluding the pseudoaneurysm and the MMA both proximal and distal to the pseudoaneurysm. CONCLUSION Spontaneous thrombosis of an MMAVF is rare and only seen in 13.1% of cases. However, subsequent delayed formation of an MMA pseudoaneurysm has not been described. Our case therefore demonstrates that MMAVF thrombosis may not indicate complete healing of the underlying injury to the MMA, and suggests the need for continued follow-up of such lesions despite initial apparent resolution.

Sphenoparietal sinus transposition technique: optimization of the surgical corridor with preservation of prominent bridging veins between the brain and the cranial base during aneurysm clipping via the pterional approach.

The sylvian bridging veins between the brain and the dura on the inner surface of the sphenoid wing can restrict brain retraction for widening of the lateral retrocarotid space during clipping surgery for internal carotid artery (ICA)-posterior communicating artery (PCoA) and basilar apex (BX) aneurysms. In such cases, the authors perform extradural anterior clinoidectomy with peeling of the temporal dura propria from the periosteal dura and inner cavernous membrane around the superior orbital fissure, with the incision of the dura mater stretching from the base of the temporal side to just before the distal dural ring of the ICA (termed by the authors as the sphenoparietal sinus transposition [SPST] technique). This technique displaces the bridging segment of the sylvian vein posteriorly and enables widening of the surgical space without venous injury. In this study, the authors observed the operative nuances and investigated the usefulness of this technique. The authors retrospectively reviewed the medical charts of 66 consecutive patients with ICA-PCoA and BX aneurysms between January 2016 and July 2018. This technique was performed in 8 patients (5 patients with PCoA aneurysms and 3 with BX aneurysms) in whom the bridging segments of the sylvian veins between the brain and the skull base restricted brain retraction for widening of the surgical space. The surface areas of the lateral retrocarotid space and the aneurysm were measured at the most visible working angle before and after the SPST technique was performed. With the use of the SPST technique, an adequate surgical space for aneurysm clipping was obtained with preservation of the bridging veins in all patients. The mean surface areas of the lateral retrocarotid space (p = 0.002) and aneurysm (p = 0.001) were significantly increased from 18.3 ± 18.8 and 2.8 ± 2.5 cm2 before to 64.2 ± 21.1 and 20.9 ± 20.6 cm2, respectively, after the SPST technique was performed. The SPST technique enables displacement of the bridging segments of the sylvian veins without venous injury and enables widening of the surgical space around the lateral retrocarotid area.

Cerebral venous congestion correlates to acute aneurysm rupture: An illustrative case with Doppler ultrasonography study

BackgroundThe objective of our description is to shed light on some new hemodynamic and clinical characteristics in the unstable cerebral aneurysm Case: We describe a 54 year old woman who presented a tension headache, that increasing for several days. A CT scan performed in ER suggests a possible arterial ectasia at the level of the circle of Willis. The patient is hospitalized. An angio CT shows an aneurysm of the anterior communicating artery, without signs of fixation and/or other instability. A subsequent TCCD examination with venous study shows clear congestion at the level of the spheno-parietal sinus. The Valsalva maneuver determines an increase in local congestion. In the light of the ultrasound picture, the patient was quickly received in Neurosurgery with success.Conclusionwe describe a clinical case where the worsening tension headache was not secondary to the increase of volume of the aneurysm but was an epiphenomenon of venous congestion, explored with TCCD. The mass effect of the aneurysm determined venous sinus compression and changed the hemodynamic of the cerebral venous flow. We believe that venous outflow obstruction and a high intracranial venous pressure gradient may be a cerebral aneurysm rupture factor.