Microvascular Decompression for Trigeminal Neuralgia: A Prospective, Multicenter Study.

BACKGROUND: Microvascular decompression (MVD) is the most effective procedure for the long-term management of trigeminal neuralgia (TGN). However, retrospective and single-center studies are inherently biased, and there are currently no prospective, multicenter studies. OBJECTIVE: To evaluate the short- and long-term outcomes and complications in patients with TGN who underwent MVD at specialized Japanese institutions. METHODS: We enrolled patients with TGN who underwent MVD between April 2012 and March 2015. We recorded their facial pain grade and complications at 7 d (short term), 1 yr (mid-term), and 3 yr (long term) postoperatively. RESULTS: There were 166 patients, comprising 60 men and 106 women (mean age 62.7 yr). Furthermore, 105 patients were aged over 60 yr. We conducted neuromonitoring in 84.3% of the cases. The complete pain relief, mortality, and complication rates at the short-term follow-up were 78.9%, 0%, and 16.3%, respectively. Overall, 155 patients (93.4%) completed the long-term follow-up, with the complete pain relief and complication rates of 80.0% and 5.2%, respectively. CONCLUSION: In the hands of experienced neurosurgeons, MVD for TGN can achieve high long-term curative effects. In addition, complications are uncommon and usually transient. Our results indicate that MVD is an effective and safe treatment for patients with TGN, including elderly patients.

Prospective, Multicenter Clinical Study of Microvascular Decompression for Hemifacial Spasm.

BACKGROUND: Microvascular decompression (MVD) is the most effective procedure for hemifacial spasm (HFS). MVD results from nonspecialized or low-volume institutes are not always reliable. Most studies on MVD for HFS are retrospective and single centered; to the best of our knowledge, no prospective, multicenter studies exist. OBJECTIVE: To evaluate short- and long-term outcomes and complications in patients who underwent MVD for HFS in specialized Japanese institutions, in this multicenter, prospective, cohort study. METHODS: Included patients had undergone MVD for HFS in study centers between April 2012 and March 2015. Patients' postoperative grade of involuntary movements and complications were recorded postoperatively at 7 d (short-term) and at 1 (mid-term) and 3 (long-term) yr. RESULTS: A total of 486 patients (150 men, 336 women; mean age 53.9 yr with 181 patients over 60 yr) were enrolled during the study period. Neuromonitoring was used in 96.3% of the cases. The complete cure rate of symptom relief, mortality rate, and complication rate at short-term follow-up were 70.6%, 0%, and 15%, respectively. The long-term follow-up was completed by 463 patients (95.3%); the complete cure rate of symptom relief and complication rate were 87.1% and 3.0%, respectively. CONCLUSION: Our study revealed that under expert guidance and intraoperative neuromonitoring, the long-term curative effect rate of MVD for HFS is high, while complications are uncommon and usually transient. Our results indicate that MVD is an effective and safe treatment for patients with HFS, including elderly patients.

Prediction of thrombolytic therapy after stroke-bypass transportation: the Maria Prehospital Stroke Scale score.

There is no prehospital stratification tool specifically for predicting thrombolytic therapy after transportation. We developed a new prehospital scale named the Maria Prehospital Stroke Scale (MPSS) by modifying the Cincinnati Prehospital Stroke Scale. Our objective is to evaluate its utility in a citywide bypass transportation protocol for intravenous (IV) tissue plasminogen activator (tPA). In the MPSS, facial droop, arm drift, and speech disturbance are tested by emergency medical technicians (EMTs). Facial droop is graded as normal (0) or abnormal (1), and the other 2 items are graded in 3 levels as normal (0), not severe (1), and severe (2). Thus, the total MPSS score ranges from 0 to 5. The predictive value of MPSS for thrombolytic therapy after bypass transportation was evaluated in 1057 patients. The MPSS scored by EMTs was significantly correlated with the National Institutes of Health Stroke Scale score in the emergency room (Spearman rho = .67, P = .000). The onset-to-door time was significantly longer with a low MPSS score (analysis of variance, F5,4.21 = .001). The rate of thrombolytic therapy was increased when the MPSS score increased from 0 to 5: 0%, 4.1%, 8.8%, 13.0%, 20.3%, and 31.5%, respectively. The areas under the receiver operating characteristic curve for the correct diagnosis of stroke and prediction of IV tPA therapy were calculated as .737 (95% confidence interval [CI]: .688-.786) and .689 (95% CI: .645-.732), respectively. Multivariate logistic regression analysis showed that the MPSS score and the detection-to-door time were independent predictors of tPA use after transportation. The MPSS is a novel prehospital stratification tool for the prediction of thrombolytic therapy after transportation.

A proposal for standardized analysis of the results of microvascular decompression for trigeminal neuralgia and hemifacial spasm.

BACKGROUND: The purpose of this study was to evaluate and analyze overall postoperative results from microvascular decompression (MVD) by combining the cure rate of symptoms with the complication rate. A new scoring system for obtaining objective surgical results from MVD for trigeminal neuralgia (TN) and hemifacial spasm (HFS) is proposed to document treatment results using consistent criteria in a standardized manner. METHOD: Surgical results combining complications , if any, were obtained from a questionnaire sent to patients who had undergone surgery for TN or HFS in recent years and had been followed-up for more than 1 year after surgery (TN patients, n = 54; HFS patients, n = 81) When surgical outcome is complete resolution of symptoms, the efficacy of surgery (E) is designated E-0, but when moderate symptoms are still persist postoperatively, the score is designated E-2. When no complications are seen after surgery, the complication score (C) is C-0, while the score is C-2 if troublesome complications remain. In addition, total evaluation of the results (T) is judged by combining the E and C scores. For example, when E is 0, and C is C-2, the total evaluation is scored as T-2, which is diagnosed as fair. FINDINGS: The response rate of the questionnaire was 80.7% (109/135). Overall surgical data were evaluated and analyzed using our new scoring system. Analysis of the collected data revealed an outcome of T-0 was 70% (35/50 patients) and T-1 was 24% (12/50) and T-2 was 6% (3/50) in TN, whereas in HFS, T-0 was 61% (36/59) and T-1 was 27.1% (16/59) and T-2 was 6.8% (4/59) and T-3 was 5.1% (3/59). CONCLUSION: The total results of MVD should be evaluated and analyzed by combining the cure rate of symptoms together with the complication rate. This new scoring system could allow much more objective analysis of the results of following MVD. Adopting this scoring system to objectively judge treatment results for TN and HFS, individual surgeons can compare their own overall surgical results with those of other institutes. Comparative results of MVD can also be provided to patients considering therapy to allow informed decision-making on the basis of good quality evidence.

[Extradural en bloc removal and in situ replacement of the anterior clinoid process].

Extradural removal of the anterior clinoid process (ACP) is useful and essential for approaching aneurysmal and tumor lesions in and around the cavernous sinus. A safe, rapid and less invasive technique is beneficial for this basic skull base surgery. We developed a new technique by sharply cutting the ACP together with the part of the sphenoid ridge bone followed by complete replacement. A series of patients with either basilar top or internal carotid artery aneurysms underwent the present technique. After frontotemporal craniotomy, the lateral frontal and anterior middle cranial fossae are exposed extradurally. The bone was cut using a cutting steel burr from the sphenoid ridge to the superior orbital fissure and to the optic canal. By sharply separating the meningo-orbital band between the dura propria and the periorbital fascia, the ACP is exposed. The cutting burr runs underneath the ACP. By leaving a very thin sheet of bone, the entire bone piece was elevated after fracturing the thin bone using a chisel. By severing the carotid ring, the internal carotid artery is freed and mobile either laterally or medially to obtain an ample basal cistern. After operation, the once removed clinoid process is replaced in situ using a titanium plate screw. Extradural en bloc removal and in situ replacement of the ACP can be safely done by this cutting procedure. This can provide a good cosmetic result without causing enophthalmos or transient oculomotor palsy.

Drainage or packing of the sella? Transsphenoidal surgery for primary pituitary abscess: report of two cases.

The detailed surgical procedure of the transsphenoidal surgery for pituitary abscess has scarcely been described previously because it is a very rare clinical entity. The authors reported two cases of primary pituitary abscess. In case 1, the anterior wall of the sella turcica was reconstructed with the vomer bone after irrigating the abscess cavity, but the sella was not packed by fat for fear of the persistent infection by devascularized tissues. This led to the postoperative meningocele, the cerebrospinal fluid leak, and bacterial meningitis despite the successful abscess drainage. In case 2, tight sellar packing and reconstruction of the sellar wall were performed to avoid these postoperative complications, which resulted in complete drainage and uneventful postoperative course. Although accumulation of more cases is obviously needed to establish the definitive surgical technique in pituitary abscess surgery, our experience might suggest that packing of the sella is not impeditive for postoperative sufficient drainage.

[Transposition technique of microvascular decompression for hemifacial spasm without using a brain retractor].

A unique transposition technique in microvascular decompression for hemifacial spasm (HFS) was employed in patients with compression by either the peripheral artery or the main trunk of the vertebral artery. Complete transposition that secured free space between the offending artery and the root exit zone (REZ) was accomplished by introducing GORE-TEX tape around the artery and suturing it to the petrous dura. An adequate working space, as if operating in a shallow basin, was essential. Throughout the procedure, it was not necessary to use a brain retractor. Instead, a gentle wrapping retraction technique using a sucker was employed over the brain covered by a sheet of Gelfoam (Pfizer Japan Inc., Tokyo) and cotton. All patients showed complete cure of HFS immediately after surgery with this technique. The difficulty of transposing the vertebral artery can be overcome by well-designed surgical strategy and skillfulness.

Posterolateral odontoidectomy for irreducible atlantoaxial dislocation: a technical case report.

BACKGROUND CONTEXT: For the treatment of irreducible atlantoaxial dislocation (AAD), anterior decompression has been commonly used by removal of the odontoid process and fixation of the vertebral body by means of the transoral approach. Although the transoral approach has been well established, there are some disadvantages. By contrast, there have been few technical case reports of the posterolateral approach, especially for irreducible AAD. PURPOSE: To describe a technical case report of the posterolateral approach for irreducible AAD, demonstrating the specific advantages. STUDY DESIGN/SETTING: Technical case report. PATIENT SAMPLE: Case report. OUTCOME MEASURES: Report of postoperative symptoms. METHODS/DESCRIPTION: A 74-year-old woman presented with sudden left hemiparesis because of irreducible AAD. She underwent the odontoidectomy and reduction by means of the posterolateral approach. Posterior fixation with instrumentation and an iliac bone graft was performed 16 days later. The results of radiological examinations were satisfactory. The posterolateral approach takes advantage of the particular features of C1-C2 dislocation of irreducible AAD. CONCLUSIONS: We suggest the possibility that the posterolateral approach is feasible and effective in most cases with irreducible AAD.

[A case of pial single-channel cerebral arteriovenous fistula].

A 60-year-old man presented with dizziness, dysarthria, and right hemifacial palsy with sudden onset. Computed tomography scan revealed a small cerebellar hematoma near the left flocculus. Since the site of the hemorrhage was atypical for cerebellar hemorrhages, emergency angiography was performed and revealed a pial single-channel arteriovenous fistula (AVF) in the early arterial phase with drainage into the dilated perimedullary vein. The feeding artery was a peripheral branch of the left anterior inferior cerebellar artery. There were no angiographical findings indicating a nidus or capillary network. The patient underwent left lateral suboccipital craniotomy. A small dilated perimedullary vein and an abnormally red spherical varix were found during the operation. A peripheral branch of the left anterior inferior cerebellar artery was thought to be a feeder because it seemed to be firmly attached to the dilated vein. Based on the operative technique for dural AVFs, electrocoagulation of the varix was performed aiming at obliteration of the fistula. The postoperative angiogram demonstrated the obliteration of the fistula and of the early filling vein. Feeders of cerebral AVF are cerebral arteries. A pial single-channel AVF is defined as a vascular malformation with a single venous channel in communication with one or more arteries with no intervening nidus or vessels. To date, reports in the literature of cerebral arteriovenous fistula have been very few. Its clinical entities such as origin, bleeding rate and the necessity of surgery remain subjects of debate. Here we report our experience and discuss its issues of the treatment we used.

Tilting operating table with self-control foot switch: a new neurosurgical tool.

BACKGROUND: Observation of the surgical field from all directions is essential in microneurosurgery. A tilting operating table operated by the surgeon can satisfy this need. METHODS: A tilting operating table operated by the surgeon using a foot switch was developed by modifying the Sugita table incorporating the X-Y shifter. RESULTS AND CONCLUSIONS: The modified operating table allows the surgeon to move the patient in the head up or down directions, as well as the left side down or right side down directions, so the surgical field can be inspected from all aspects without changing the vertical axis of the operating microscope.

Snare technique of vascular transposition for microvascular decompression--technical note.

Recurrence of trigeminal neuralgia (TN) or hemifacial spasm (HFS) after microvascular decompression (MVD) is not rare. The prosthesis material eventually adheres to the neurovascular structures and again transmits arterial pulsation to the nerve. A snare ligature technique using a Gore-Tex tape can be used for the transposition of the offending artery. No prosthesis is necessary once the transposition is complete. This technique requires introduction of either Gore-Tex tape or thread around the artery and suture over the petrous dura, so an adequate working space as if operating in a shallow basin is essential. Therefore, the osteoplastic craniotomy is a little larger than usual with the scalp flap entirely reflected using a semicircular skin incision. The Gore-Tex tape can be directly snared around the artery and sutured over the petrous dura. If this procedure is difficult, a thread can be attached to both ends of the Gore-Tex tape to pass the tape around the vessel. Seven patients with TN and 13 patients with HFS have undergone this surgery. Although the follow-up period is not yet long enough, there has been no case of recurrence. The present technique for MVD can provide complete and permanent transposition of the offending artery.

[Surgery of AVM of the inferior medullary velum by the uvulotonsillar approach--advantage of moving of the cerebellar tonsil: technical case report].

An incidentally found arteriovenous malformation (AVM) of the inferior medullary velum behind the medulla was removed by the lateral approach to the fourth ventricle originally described by Seeger in 1980. A wide posterior fossa craniotomy was performed to move the cerebellar tonsil laterally with C-1 laminectomy. The tela chroidea and inferior medullary velum, the two main sheets of tissue that form the lower half of the roof of the fourth ventricle can be exposed by gently displacing the tonsils laterally without splitting the vermis. Both the cerebellomedullary and uvulotonsillar spaces were exposed. Because the lateral cerebellomedullary cistern was also exposed, the moving of the cerebellar tonsil in a lateral direction was easy to do without injuring the cerebellar tissues. The nidus was located mainly in the extrapial plane that received feeding arteries from the posterior inferior cerebellar artery. The nidus was removed in a dry field without bleeding. This report is the first report of surgical removal of unruptured AVM of the inferior medullary velum through the so-called telovelar or transcerebellomedullary fissure approach. We propose to call this approach the uvulotonsillar approach to emphasize the dissecting plane between the uvula and the tonsil.