Superior Petrosal Sinus Research Articles

Evaluation of drainage patterns of the major anastomotic veins on the lateral surface of the cerebrum using three-dimensional contrast-enhanced MP-RAGE sequence

Background and purpose Three-dimensional (3D) contrast-enhanced magnetization-prepared rapid gradient-echo (MP-RAGE) sequence has been reported useful for evaluation of the intracranial venous structures. The purpose of this study is to assess the patterns of the major anastomotic veins on the lateral surface of the cerebrum using MP-RAGE sequence. Methods MP-RAGE images in consecutive 100 patients (200 sides) were reviewed by two neuroradiologists in consensus to evaluate drainage patterns of the superficial middle cerebral vein (SMCV), the vein of Labbe, and the Trolard vein. Results MP-RAGE images clearly depicted the major anastomotic veins and their draining vessel. The dominant vein was the Trolard vein in 12%, the vein of Labbe in 36%, SMCV in 38%, and all three veins in 14%. The vein of Labbe was entered the transverse sinus in 80% and superior petrosal sinus in 4%. Undeveloped type of the vein of Labbe was seen in 16%. The SMCVs were entered the sphenoparietal sinus in 57%, the cavernous sinus in 19%, and the emissary vein in 5%. Basal type of the SMCVs was seen in 3% and undeveloped type in 16%. It was difficult to differentiate the Trolard vein from other cortical veins, if it was not dominant. In the most cases with the dominant Trolard vein, it located at the level of the post central vein. Conclusion With MP-RAGE sequence, it is easy to identify the variation of the major anastomotic veins. Such information may be helpful to reduce the risk of damage on these important veins at surgery.

Custom-tailored transdural anterior transpetrosal approach to ventral pons and retroclival regions

The extradural anterior petrosectomy approach to the pons and midbasilar artery (mid-BA) has the main disadvantage that the extent of resection of the petrous apex cannot be as minimal as desired given that the surgical target field is not visible during bone removal. Unnecessary or excessive drilling poses the risk of injury to the internal carotid artery, vestibulocochlear organ, and seventh and eighth cranial nerves. The use of a custom-tailored transdural anterior transpetrosal approach can potentially avoid these pitfalls. A technique for a transdural anterior petrosectomy was developed in the operating theater and anatomy laboratory. Following a subtemporal craniotomy and basal opening of the dura mater, the vein of Labbé is first identified and protected. Cerebrospinal fluid ([CSF] 50-100 ml) is drained via a spinal catheter. The tent is incised behind the entrance of the trochlear nerve toward the superior petrosal sinus (SPS), which is coagulated and divided. The dura is stripped from the petrous pyramid. Drilling starts at the petrous ridge and proceeds laterally and ventrally. The trigeminal nerve is unroofed. The internal acoustic meatus is identified and drilling is continued laterally as needed. The bone of the Kawase triangle toward the clivus can be removed down to the inferior petrosal sinus if necessary. Anterior exposure can be extended to the carotid artery if required. It is only exceptionally necessary to follow the greater superior petrosal nerve toward the geniculate ganglion and to expose the length of the internal acoustic canal. The modified transdural anterior petrosectomy exposure has been used in nine patients-two with a mid-BA aneurysm, two with a dural arteriovenous fistula, one with a pontine glioma, three with a pontine cavernoma, and one with a pontine abscess. In one patient with a mid-BA aneurysm, subcutaneous CSF collection occurred during the postoperative period. No CSF fistula or approach-related cranial nerve deficit developed in any of these patients. There was no retraction injury or venous congestion of the temporal lobe nor any venous congestion due to the obliteration of the SPS or the petrosal vein. The custom-made transdural anterior petrosectomy appears to be a feasible alternative to the formal extradural approach.

Endovascular GDC Treatment of an Idiopathic Carotid-Cavernous Fistula Caused by Aneurysmal Rupture of the Intra-Cavernous Carotid Artery

Aneurysmal rupture of the intra-cavernous carotid artery may cause idiopathic carotid-cavernous fistula (CCF), and the treatment choice for occluding shunting fistula in this type of CCF is an endovascular approach using detachable balloons. However, little has been reported on treating such lesions with the intra-aneurysmal embolization using Guglielmi detachable coils (GDCs).To our knowledge, ours is the first reported case of successful treatment by selective intra-fistula and intra-aneurysmal embolization with GDCs. A 74-year-old woman exhibited proptosis and chemosis of her left eye over a period of one month. Symptoms of double vision in conversion and pulsatile murmur in her left eye were also noted. Angiography revealed an intra-cavernous aneurysm of the left internal carotid artery (ICA) with a shunting fistula, which drained into the dilated cavernous sinus, superior orbital vein (SOV), superior petrosal sinus, inferior petrosal sinus, and pterygoid plexus.We thought the fistula would occlude by intra-aneurysmal embolization, but we had no confidence of tight packing of the aneurysm since the aneurismal neck was relatively wide. So, we embolized the venous side of the shunting fistula and then the dome of the aneurysm with GDCs. Immediately after the operation, her symptoms and signs were ameliorated, and complete occlusion of the CCF was observed on long-term follow-up. We suggest selective intrafistula and intra-aneurysmal embolization with GDCs as an alternative method of treatment of idiopathic CCF originating from aneurysmal rupture of the intra-cavernous carotid artery.

Benefits and limitations of image guidance in the surgical treatment of intracranial dural arteriovenous fistulas

Despite major advances in endovascular embolization techniques, microsurgical resection remains a reliable and effective treatment modality for dural arteriovenous fistulas (DAVF). However, intraoperative detection of these lesions and identification of feeding arteries and draining veins can be challenging. In a series of 6 patients who were not candidates for definitive treatment by endovascular embolization we evaluated the benefits and limitations of computer-assisted image guidance for surgical ablation of DAVF. Of the 6 patients, 5 presented with haemorrhage and one with seizures. Diagnosis of DAVF was made by conventional angiography and dynamic contrast enhanced MR angiography (CE-MRA). All patients were surgically treated with the assistance of a 3D high resolution T1-weighted MR data set and time-of-flight MR angiography (MRA) obtained for neuronavigation. Registration was based on cranial fiducials and image-guided surgery was performed with the navigation system. Four of the 6 patients suffered from DAVF draining into the superior sagittal sinus, one fistula drained into paracavernous veins adjacent to the superior petrosal sinus and one patient had a pial fistula draining in the straight sinus. DAVF diagnosed with conventional angiography could be located on CE-MRA and MRA prior to surgery. MRI and MRA images were combined on the neuronavigation workstation and DAVF were located intraoperatively by using a tracking device. In 4 out of 6 cases neuronavigation was used for direct intraoperative identification of DAVF. Brain shift prevented direct tracking of pathological vessels in the other 2 cases, where navigation could only be used to assist craniotomy. Microsurgical dissection and coagulation of the fistulas led to complete cure in all patients as confirmed by angiography. Neuronavigation may be used as an additional tool for microsurgical treatment of DAVF. However, in this small series of 6 cases, surgical procedures have not been substantially altered by the use of the neuronavigation system. Image guidance has been beneficial for the location of small, superficially located DAVF, whereas a navigated approach to deep-seated lesions was less accurate due to the familiar problem of brain shift and brain retraction during surgery.

Evaluation of petrosal sinus patency with 3-dimensional contrast-enhanced magnetic resonance venography in petroclival meningiomas for surgical strategy

Background The aim of this study was to perform a detailed anatomical analysis of petroclival venous structures as well as their patencies with 3D contrast-enhanced (CE) magnetic resonance venography (MRV) and to identify the potential contribution of these data to the therapeutic approach. Methods Ten patients (8 women and 2 men) with unilateral petroclival meningioma were examined using 3D CE MRV in addition to conventional brain protocol. Both coronal source and multiplanar reconstructed images were evaluated for the anatomical orientation. Patency of the cavernous sinus, superior petrosal sinus (SPS), and inferior petrosal sinus (IPS) was assessed. Results All the patients had a unilateral meningioma (7 on the right and 3 on the left) at the petroclival region. Both SPS and IPS were visualized with adequate intraluminal contrast enhancement in 6 patients, but IPS was absent in 3 on the lesion side, with a patent superior petrosal sinus as the drainage route. One patient had a partially occluded SPS, with IPS being the main course of cavernous sinus drainage. Conclusions Cerebral venous anatomy is a challenge to display with noninvasive methods because of flow dynamics, and CE 3D imaging seems to be the modality of choice to evaluate the variational anatomy and patency, which is essential in petroclival meningiomas. Because the cavernous sinus drains into either IPS or SPS, the patent sinus should be protected in surgery if there is tumoral occlusion of the others.

Anatomic Variations of the Superficial Middle Cerebral Vein: Embryologic Aspects of the Regressed Embryonic Tentorial Sinus

The embryonic tentorial sinus usually regressses during postnatal development, but its typical prenatal drainage patterns and intradural anastomoses can be depicted as various developmental phenotypic representations. Here, we tried to clarify the variant types of the superficial middle cerebral vein (SMCV) associated with the embryonic tentorial sinus. Total 41 patients and 82 hemispheres were included in this study. CT angiography was performed in all patients as screening for cerebrovascular disease or other intracranial disorders. A separate workstation and 3D software were used to evaluate the cranial venous systems with 3D volume rendering techniques, thin-slice MIP images, and MPR techniques for the analysis of its complicated angioarchitecture. Variations of the SMCV were classified according to the developmental alterations of the embryonic tentorial sinus, including sphenoparietal sinus (cranial remnant of tentorial sinus), basal sinus (floor of middle cranial fossa), petrosal and caudal remnant of the tentorial sinus. Secondary intradural anastomoses of cavernous and superior petrosal sinuses were also evaluated for the efferent pathways. The most frequent type of remnant tentorial sinus, sphenoparietal sinus was present in 49% (40/82) of hemispheres examined. Other regressed patterns of embryonic tentorial sinus were also identified in 38% (31/82): nine caudal remnant type around the transverse sinus, 12 petrosal type, one basal type, five unclassified cases, and mixed type were found in four cases. Secondary intradural cavernous sinus anastomosis was seen in 44% (36/82), however the most prevalent pattern was no anastomosis (46/82) with cavernous sinus. Only one case of superior petrosal sinus anastomosis was found in this series associated with basal sinus type. Anatomic variations of SMCV can be clearly demonstrated with embryologic aspects of the tentorial sinus according to its developmental regression and postnatal secondary adaptations of cerebral venous drainage.

Assessment of Dural Arteriovenous Fistulae by Transcranial Color-Coded Duplex Sonography

To study hemodynamic changes and to determine the value of contrast-enhanced transcranial color-coded sonography (TCCS) for the evaluation of dural arteriovenous fistulae (DAVF) before and after transcatheter embolization. Twenty-four patients (mean age 61+/-11 years) with occipitally located DAVF were studied with contrast-enhanced TCCS using the transtemporal bone window in transverse-axial and coronal insonation planes. Blood flow velocity measurements of all depictable basal cerebral veins and sinuses were obtained before and after transcatheter embolization. Pretreatment and post-treatment flow velocity values were compared. Four of the 24 patients (17%) could not be studied because of an insufficient temporal bone window. In all remaining patients (n=20), draining veins/sinuses could be identified because of pathologically increased blood flow velocities with peak systolic flow velocities of >50 cm/s. Of the 27 draining vessels depicted by DSA, TCCS correctly identified 25 (93%): the basal vein (3 of 3), the straight sinus (3 of 3), the superior sagittal sinus (1 of 3), the transverse sinus (9), the sigmoid sinus (4), and the superior petrosal sinus (5/5). However, TCCS failed to depict supplementary drainage via cortical veins. After transcatheter embolization, mean reduction of blood flow velocity was 44+/-18% (P<0.01) compared with pretreatment values. Contrast-enhanced TCCS is a promising technique for monitoring embolization of DAVF, follow-up after complete fistula occlusion, and may even be useful as a screening tool in patients with pulsatile tinnitus.

Three-dimensional Computed Tomography Angiography of the Galenic System for the Occipital Transtentorial Approach

The venous variations of the galenic system were evaluated using three-dimensional computed tomography angiography (3D-CTA) to assess the influence on the occipital transtentorial approach in 150 patients who underwent 3D-CTA as a routine screening examination for cerebrovascular diseases. The variations of the vein of Galen with its tributaries, the tentorial sinus, and the veins around the tentorium were evaluated in multiple intensity projections and stereoscopic images. The angle between the vein of Galen and the straight sinus was 67.1 +/- 31.9 degrees (mean +/- SD). Observation of the pineal body from the direction of the approach tended to extend to the quadrigeminal bodies in acute angle cases, and to the third ventricle in obtuse angle cases. Bilateral internal cerebral veins (ICVs) joined in the anterior portion were associated with a long vein of Galen, or in the posterior portion with a short vein of Galen. The distance between the bilateral ICVs was 4.66 +/- 2.28 mm (mean +/- SD), and the shape of the space could be classified as spindle, parallel, hairpin, and round types. The basal vein could be classified into well-developed, hypoplastic, hardly recognized, and mimicking two basal veins because the tributary did not join but ran parallel to the basal vein. The drainage pathways lead to the anterior or posterior portion of the vein of Galen, the ICV, the tentorial sinus, and the superior petrosal sinus. The various types of the tentorial sinus and primitive tentorial sinus which might be sacrificed during section of the tentorium were confirmed. The inferior cerebral vein draining to the tentorial sinus could be seen. 3D-CTA could also demonstrate the presence, the course, and the drainage points of the internal occipital vein, the precentral cerebellar vein, the posterior pericallosal vein, and so on. 3D-CTA is useful to evaluate the variations of the venous system and the relationship with the tumor, and for preoperative simulation and intraoperative navigation of the occipital transtentorial approach.

MRI diagnosis of carotid cavernous fistula: a report of 12 cases

目的 分析颈动脉海绵窦瘘(CCF)的MRI表现及诊断价值.方法 搜集近年有完整临床资料的CCF 12例进行MRI表现的回顾性分析.其中男8例,女4例;外伤性CCF 11例,自发性1例,均由DSA造影证实.结果 MRI主要表现为:(1)眼球突出11例;(2)海绵窦扩大12例;(3)眼上静脉扩张、迂曲 11例,蝶顶窦和大脑中、浅静脉扩张2例,岩上窦和岩下窦扩张2例,眼下静脉和眼睑静脉扩张 1例;(4)眼外肌增粗3例;(5)脑萎缩3例,脑水肿和脑出血2例.结论 MR检查是一种无创伤的诊断CCF的方法,具有准确、方便、特异性高等优势,能明确病变部位及程度,但应进行必要的鉴别诊断。

Origin of High Signal Intensity in the Cavernous Sinus in MR Angiographic Source Images

To investigate the origin of a high signal intensity in a cavernous sinus on magnetic resonance (MR) angiography. Time-of-flight MR angiography was performed in 20 patients scheduled for conventional angiography for disease not related to carotid cavernous fistula. Venous drainage pattern was assessed, and flow rate to a cavernous sinus was semiquantitatively evaluated on conventional angiography. Two sinuses showed high signal intensity in the anterior portion. These were associated with direct venous drainage to the anterosuperior aspect of the cavernous sinus from the superficial middle cerebral vein, and their flow rates were among the 10% of the sides with the highest flow rates. Two other sinuses showed high signal intensity in the posterior portion. Their flow rates from the superficial petrosal sinus were also among the 10% of the sides with the highest flow rates. High signal intensity in the anterior or posterior portions of the cavernous sinus is probably a result of inflow from the superficial middle cerebral vein and the superior petrosal sinus, respectively.

Guidelines for the Ligation of the Sigmoid or Transverse Sinus during Large Petroclival Meningioma Surgery

The authors present guidelines for the ligation of the transverse or sigmoid sinus during the surgical removal of petroclival meningiomas. The medical records and venograms of 14 patients with a petroclival meningioma requiring transverse or sigmoid sinus ligation treated in the Department of Neurosurgery, Seoul National University Hospital between 1986 and 1999 were reviewed. All patients successfully received a sinus trial clamping during the operation. The drainage pattern of the confluens of Herophili was classified into four types: Type A, confluens and equal on both transverse sinuses; Type B, confluens and nondominant transverse sinus on the tumor side; Type C, confluens and dominant transverse sinus on the tumor side; and Type D, unilateral transverse sinus only. Of the 14 cases, four were Type A, five were Type B, and two were Type C. There was no brain swelling after intraoperative test clamping of the sinus for more than 30 minutes. None of the cases developed postoperative complications related to the sinus ligation. Patients with Type A, B, or C drainage patterns were ideal candidates for sinus ligation, especially transverse sinus ligation, if the test clamping proved to be safe. The sinus was cut proximal to the superior petrosal sinus, distal to the vein of Labbé.

Endovascular and Surgical Treatment for Dural Arteriovenous Fistulae of the Superior Petrosal Sinus

Endovascular and Surgical Treatment for Dural Arteriovenous Fistulae of the Superior Petrosal Sinus

The sphenopetroclival venous gulf: a microanatomical study.

The sphenopetroclival area is the border zone between the middle and posterior cranial fossa. Several authors have studied the microsurgical anatomy of this region and have furnished sometimes contradictory descriptions of this area, which still represents a great challenge for the neurosurgeon. On the basis of previous anatomical data reported in the literature, the authors undertook a new microanatomical analysis of the sphenopetroclival region and report their findings. Twenty human cadaveric heads were used to reproduce, in the laboratory, different skull base approaches to expose the petroclival area. Measurements were taken in 40 specimens. From this study has emerged the finding that the sphenopetroclival area is a venous space, which the authors have named the "sphenopetroclival venous gulf" (SPCVG). The SPCVG is filled anteriorly by blood from the cavernous sinus (lateral sellar compartment [LSC], medially by blood from the basilar plexus, and laterally by blood from the superior petrosal sinus; this venous gulf is drained by the inferior petrosal sinus. The SPCVG is comparable in shape to an irregular hedron figure. It contains the Dorello canal, the venous segment of the abducent nerve, and the superior sphenopetrosal (Gruber) ligament, the fibers of which are in anatomical continuity with those of the inferior sphenopetrosal (petrolingual) ligament, forming a "falciform ligament." The structures defining the posterior surface of the SPCVG may represent a helpful surgical corridor through which it is possible to approach the LSC via the posterior fossa. This conceptualization of the SPCVG is an attempt to define univocally the microanatomy of the sphenopetroclival region in its entirety.

Endovascular treatment for dural arteriovenous fistulae of the superior petrosal sinus.

To determine the usefulness of endovascular embolization for treatment of dural arteriovenous fistulae of the superior petrosal sinus. We performed a retrospective review of 18 patients treated during a 16-year period. Transarterial and/or transvenous embolizations were performed as a preoperative adjunct or definitive therapy. Clinical follow-up status was supplemented by telephone interviews to determine Glasgow Outcome Scale scores. Fourteen patients (78%) were treated with a combination of endovascular therapy and open surgery, and 4 were treated by embolization alone (22%). Angiographic cure was achieved in all patients (100%). Thirty-day morbidity and mortality were 11 and 0%, respectively. The mean follow-up period was 5.4 years. At the latest follow-up examination, all patients had returned to independent clinical status (Glasgow Outcome Scale scores of 1 or 2). Endovascular treatment of dural arteriovenous fistulae of the superior petrosal sinus can result in cure when access to the site of the fistula can be achieved. Preoperative embolization is a safe and effective adjunct to minimize bleeding during open neurosurgery.

Cavernous sinus dural arteriovenous malformations: Patterns of venous drainage are related to clinical signs and symptoms

Objective To provide evidence that venous congestion and drainage patterns are responsible for the manifestations of cavernous sinus area dural arteriovenous malformations (CSdAVMs). Design Retrospective observational case series. Participants Records of 85 patients with complete clinical and angiographic evaluations of CSdAVMs were evaluated for the clinical features of the disorder. A neuroradiologist analyzed patterns of venous drainage to and from the cavernous sinus without knowledge of the clinical features. Four venous drainage patterns (reversal of flow from the CSdAVMs into the anterior cavernous sinus, ophthalmic vein thrombosis, drainage into the inferior petrosal sinus or drainage into the superior petrosal sinus) were statistically tested for their predictive value of signs and symptoms using logistic regression. Main outcome measures The power of prediction of orbital congestion, elevated IOP, extraocular muscle dysfunction, optic neuropathy, venous-stasis retinopathy, choroidal effusion, anterior chamber shallowing, bruits, cranial nerve paresis, and central nervous system dysfunction from four patterns of venous drainage. Results Reversal of drainage into the anterior cavernous sinus and ophthalmic veins was highly predictive ( P = 0) of orbital congestion, which was seen in 77 (91%) patients. In contrast, eight (9%) patients without orbital congestion had shunts that did not drain into the anterior cavernous sinus and ophthalmic veins. Cavernous sinus dural arteriovenous malformation drainage into the anterior cavernous sinus and ophthalmic veins also predicted elevated IOP ( P = 0.0023) and optic neuropathy ( P = 0.047). Ophthalmic vein thrombosis significantly predicted cases with choroidal effusion ( P = 0.002) and anterior chamber shallowing ( P = 0.01). Third nerve paresis could be predicted from flow toward the inferior petrosal sinuses ( P = 0.017). Central nervous system symptoms or dysfunction, occurring in 7 (8%) patients, was predicted by venous drainage into the superior petrosal sinus ( P = 0.0008). Conclusions The clinical features found in patients with CSdVAMs are related to the abnormal venous drainage and can be predicted by these venous drainage patterns. Venous congestion and hypertension seem to cause the clinical dysfunction in this disorder.

Transcranial approach for venous embolization of dural arteriovenous fistulas

Transvenous embolization is effective in the treatment of an intracranial dural arteriovenous fistula (DAVF). Access to the fistula via the internal jugular vein (IJV) may be limited by associated dural sinus thrombosis; a transcranial approach has been developed for venous embolization in such a situation. The authors report their experiences with the use of a transcranial approach for venous embolization of DAVFs. Ten patients with DAVFs underwent craniectomy and embolization procedures in which direct sinus puncture was performed. The DAVFs were located inside the dura mater that constituted the walls of the transverse sinus in five cases, the superior sagittal sinus in four cases, and the superior petrosal sinus in one case. All DAVFs drained directly into a sinus with secondary reflux into leptomeningeal veins. In all cases, the fistula could not be accessed from the IJVs. Craniectomy was performed in an operating room and, in seven cases, subsequent enlargement of the craniectomy was required. Sinus catheterization was performed after the patient had been transferred to the angiography room. The DAVFs were embolized using coils only in five patients, glue only in two patients, and both coils and glue in three patients. Angiographic confirmation that embolization of the fistula was successful was obtained in all cases. A transient complication occurred during the first case after sinus catheterization was attempted in the operating room. The transcranial approach allows straightforward access to DAVFs located on superficial dural sinuses that are inaccessible from the IJVs. The effectiveness of this approach is similar to that of the standard retrograde venous approach. The correct location and adequate extent of the craniectomy are essential for success to be achieved using this technique.

浅中大脳静脈，脳底静脈のＶａｒｉａｔｉｏｎ ３Ｄ‐ＣＴＡによる検討

We evaluated variations of the superficial middle cerebral vein (SMCV) and basal vein of Rosenthal (BVR) by three-dimensional computed tomography angiography (3D-CTA) imaging. To this end, 3D-CTA images in the axial stereoscopic view and other directions were constructed by the voxel transmission method and maximum intensity projection images were obtained in 600 sides of 300 patients. The SMCV was classified into 7 courses and drainage pathways, and the BVR into 5 drainage pathways. The drainage pathways of the SMCV were the sphenoparietal sinus or cavernous sinus in 62.8% of sides, the pterygoid plexus in 12.5%, the superior petrosal sinus in 1.5%, the transverse sinus via the middle cranial fossa in 1.8%, the transverse sinus via the temporal squama in 2.2%, and others in 8.2%. The BVR flowed into the great vein of Galen in 87.8% of sides, but the anastomoses between the first and second segments were hypoplastic or aplastic in 37.0% of this type. The deep middle cerebral vein in such cases flowed into the cavernous sinus or sphenoparietal sinus. Therefore, typical BVRs with these anastomoses were present in only 53.3% of sides. More than one-fourth of the typical BVRs also entered the anterior sinuses or veins such as the cavernous sinus. Other outflow patterns were the lateral mesencephalic vein in 5.6%, the peduncular vein in 1.5%, and the lateral or medial tentorial sinus in 5.1%. Understanding of the embryonal venous drainage pathways is essential to evaluate individual variations in veins. The skull base venous system, which courses medially or laterally and longitudinally, is seen best on axial CT scans. 3D-CTA provides multidirectional stereoscopic images of specific vessels and demonstrates the anatomical relationships with the arteries and the bone structure. Therefore, 3D-CTA is useful for the investigation of individual variations and in preoperative planning for skull base surgery to reduce the invasiveness of surgery.

Transarterial Embolisation of Dural Arteriovenous Fistula Involving an Isolated Segment of the Superior Petrosal Sinus

This case report illustrates a relatively rare case of dural arteriovenous fistula (AVF) involving direct supply to an isolated segment of the superior petrosal sinus (SPS). Successful transarterial obliteration of the lesion was accomplished with only a liquid embolic agent with long-term angiographic and clinical cure.

Use of cavernous sinus EEG in the detection of seizure onset and spread in mesial temporal lobe epilepsy.

The study goal was to evaluate the clinical usefulness of intravenous EEG recording by placing wire electrodes in the cavernous sinus (CS) and the superior petrosal sinus (SPS) in patients with intractable temporal lobe epilepsy (TLE), with special emphasis on the ictal recording. We placed Seeker Lite-10 guide wire as electrodes in the bilateral CS, SPS, or both to simultaneously record both ictal and interictal EEGs with the scalp EEG in five patients with TLE. In addition, in one patient, we averaged interictal scalp and intravascular EEG time-locked to the epileptiform discharge recorded from the CS/SPS-EEG to further delineate the relationship of the spikes between scalp and intravenous recording. In four of five patients, clinically useful recording was obtained to determine ictal focus. We recorded habitual seizures in three patients, and the detailed characteristics of ictal epileptiform discharges were shown. The averaged waveform of interictal epileptiform discharges clarified the spike distribution in the scalp EEGs, which was otherwise undetectable in the single trace. All of the patients completed the intravenous EEG monitoring without any neurological or psychological problems. The CS/SPS-EEG is a relatively noninvasive method that is useful for the detection of ictal focus and its spreading pattern and thus for the selection of surgical candidate among patients with intractable TLE. Although the number of seizures detected during the short monitoring period may be limited, due to the advantages of its safety and simplicity, it is worth trying for potential surgical candidates before more invasive examinations are applied. A further study with a larger number of patients is needed to estimate its practical risk.

Venous consideration in petrosal approach: microsurgical anatomy of the temporal bridging vein.

The technical difficulty of using the petrosal approach and the likelihood of encountering venous complications depend on the particular temporal venous anatomy. To reduce such potential risks, neurosurgeons must have adequate knowledge of the variations in the anatomy of the temporal venous drainage system, particularly of the temporal bridging veins. In 20 cadaveric specimens, the temporal bridging veins were examined with the aid of an operating microscope. The anatomic location of their termination and of the tributaries of these bridging veins was noted. Forty-four terminations and 109 tributaries of the temporal bridging veins were identified in our specimens. The temporal bridging veins were divided into three groups according to the anatomic location of their terminations: 1) the transverse sinus group (seen in all 20 hemispheres), with drainage into the lateral part of the cerebellar tentorium, to which most of the vein of Labbé belongs; 2) the tentorial group (seen in 50% of the 20 hemispheres), with drainage into the medial part of the tentorium, which is composed mainly of the middle and posterior temporobasal veins; and 3) the petrosal group (seen in 55% of the 20 hemispheres), with entry around the superior petrosal sinus, which may limit mobility of the temporal lobe in the petrosal approach. On the basis of this anatomic information, we propose a new classification of the temporal venous drainage system and discuss the clinical implications of these findings. In planning the petrosal approach, great care should be taken not only with the vein of Labbé but also with the petrosal bridging veins. Knowledge of this venous anatomy can reduce venous complications during the lateral cranial base approach.