The learning curve for cavernous sinus surgery illustrated by symptomatic intracavernous aneurysm clipping through a pretemporal transcavernous approach.

OBJECTIVE: The anatomy of the cavernous sinus (CS) has been well studied in the laboratory for decades; however, performing surgery in and around the CS is still a challenge. To reveal the learning curve for CS surgery via the pretemporal transcavernous approach (PTTC), surgical procedures were examined. The authors proposed 4 levels of surgical difficulty in opening the walls of the CS through this approach. Details of the approach were illustrated by surgical videos of symptomatic intracavernous aneurysm clipping. METHODS: Four levels of surgical difficulty were proposed. The higher the level, the more the CS walls were opened. Pathologies corresponding to each level of difficulty in and around the CS were categorized in each level together with explanations. From 2015 to 2021, 5 patients with symptomatic intracavernous aneurysms (diplopia due to compressive cranial neuropathy) underwent the PTTC at the authors' institute and served as representative cases in opening the walls of the CS. All CS cases from 2009 to 2021 were reviewed and categorized to demonstrate the learning curve. RESULTS: Four levels of surgical difficulty are as follows: level 1, a basic Dolenc extradural approach, which involves opening the anterior third of the superior and lateral walls of the CS; level 2, mobilizing the internal carotid artery (ICA) and opening the proximal dural ring to enter the roof of the CS and treat lesions around the clinoid and upper cavernous ICA; level 3, opening the entire aspect of the superior and lateral walls of the CS, which involves opening the oculomotor triangle and peeling the lateral wall of the CS to the tentorial incisura; and level 4, mobilizing cranial nerves III, IV, and V1 to gain access to the supra-/infratrochlear triangles to have proximal ICA control and opening the posterior wall as the last step to enter the posterior fossa. Surgical steps were described and illustrated with surgical videos of symptomatic intracavernous aneurysm clipping. CONCLUSIONS: The learning curve for CS surgery is long. The authors use 4 levels of surgical difficulty to describe applications of the PTTC in CS surgery. This approach serves as an effective workhorse in treating CS pathologies with low morbidity and high success rates when performed by experienced neurosurgeons.

Decline in dental caries experience among schoolchildren in Taiwan, 2012-2020.

OBJECTIVES: This study investigated the association between the decline of the decayed, missing, and filled teeth (DMFT) index and several family-level and individual-level factors among 6- to 18-year-old Taiwanese children from 2012 to 2020. METHODS: This study used data from the 2012 and 2020 Taiwan National Oral Health Survey of Children and Adolescents. Both surveys used similar methods and were performed in the same study age group. A structured questionnaire was used to collect data on parents' sociodemographic background; the number of children in the family; oral health-related knowledge, attitudes, and behaviours; and children's dietary habits. Dental caries was recorded through standardized oral examinations. Multivariable multilevel zero-inflated negative binomial regression models were used to determine the association between family-level and individual-level factors and the DMFT index from 2012 to 2020. RESULTS: A total of 10 217 and 10 436 schoolchildren completed the oral examinations and questionnaires in the 2012 and 2020 surveys, respectively. The adjusted mean DMFT index of 12-year-old Taiwanese schoolchildren in 2020 was 2.01, denoting a significant decline from 2.50 in 2012 (adjusted mean ratio = 0.20, 95% confidence interval [CI] = 0.17, 0.23, p < .0001). Furthermore, children who often consumed sugar-rich drinks had a significantly higher risk (mean ratio = 1.05, 95% CI = 1.01, 1.10) of having DMFT than those who seldom consumed such drinks (p = .017). CONCLUSIONS: In the period of 2012-2020, the DMFT index among Taiwanese children significantly declined. Children who often consumed sugar-rich drinks had a higher DMFT index than those who seldom consumed such drinks. Our findings are valuable to paediatricians, dentists, nutritionists, and public health policymakers.

Oblique lateral interbody fusion in heterogenous lumbar diseases: Anterolateral screw fixation vs. posterior percutaneous pedicle screw fixation - A single center experience.

Background: Oblique lateral interbody fusion (OLIF) is a type of minimally invasive lateral lumbar interbody fusion technique used for treating lumbar degenerative diseases. This study aimed to analyze the clinical and radiographic efficacy of OLIF with anterolateral screw fixation alone and OLIF requiring fixation with conventional posterior percutaneous pedicle screws for lumbar diseases. Methods: Medical records of consecutive patients admitted to Cheng-Hsin Hospital who received OLIF between January 2019 and December 2020 were retrospectively reviewed. Patients were divided into two groups by screw fixation: patients who received anterolateral screw fixation alone were defined as one-stage OLIF (n = 9) and patients who received fixation with conventional posterior percutaneous pedicle screw were defined as two-stage OLIF (n = 16). Patient clinical characteristics, medical history, intraoperative blood loss, length of hospital stay, peri-operative, and post-operative complications were evaluated in all patients. Results: During the study period, a total of 25 patients were successfully treated with OLIF (n = 9 one-stage; n = 16 two-stage). Two-stage OLIF was associated with longer operation times, longer hospital stays, shorter bed-rest time, and a greater likelihood of having a blood transfusion compared with the one-stage OLIF group. A higher proportion of grade I subsidence was observed at 6 months and 1 year after surgery in the two-stage group compared with the one-stage group. Post-operative complications included ileus, dystonia, and dystonia were higher in the two-stage OLIF group. Improvements in radiographic parameters were demonstrated after OLIF, and the improvements were comparable between one-stage and two-stage OLIF. Conclusions: One-stage OLIF is a feasible and efficacious treatment method for single- and multiple-level degenerative lumbar diseases. Additional clinical follow-up is necessary to confirm long-term outcomes.

The pretemporal trans-cavernous trans-Meckel's trans-tentorial trans-petrosal approach: a combo skill in treating skull base meningiomas.

PURPOSE: Surgical treatments for skull base meningiomas are challenging. We found that most of these lesions (75%), despite locating at the anterior, middle or posterior fossa, could be dealt with a combo skill-the pretemporal trans-cavernous trans-Meckel's trans-tentorial trans-petrosal approach (PCMTP), which adopted the same curvilinear skin incision as for the classic pterional approach. Our aim of this study is to validate the application of this technique in treating skull base meningiomas. METHODS: Patients underwent surgical intervention at our institute during 2010-2018 were retrospectively reviewed. We statistically analyzed the clinical, radiological, and pathological outcomes. RESULTS: In total, 109 patients operated with at least part of the PCMTP combo technique were included. The median follow-up time was 26.6 months. Tumor locations were categorized into: Zone I-sphenoid ridge, olfactory groove, and juxtasellar meningiomas which could be dealt with pterional approach. Zone II-clinoidal and cavernous sinus meningiomas which could be dealt with pretemporal trans-cavernous approach. Zone III-Meckel's and Incisura meningiomas which could be dealt with trans-Meckel's trans tentorial approach. Zone IV-petroclival menigiomas which could be dealt with trans-petrosal approach. When an extensive tumor occupied the anterior, middle, and posterior fossa, the whole combination of the PCMTP technique was applied. The mortality rate is 3.7% (4 patients). Three patients (2.8%) suffered from postoperative deterioration and required occasional assistance. The location of tumor was associated with different Simpson grade removal (p = 0.0015) and resection rate (p < 0.001). CONCLUSION: The PCMTP is effective in treating skull base meningiomas.

Procedure-Related Temporal Infarct After Retractorless Transsylvian Selective Amygdalohippocampectomy and Impact on 2-Year Epilepsy Outcome.

BACKGROUND: Selective amygdalohippocampectomy (SAH) is designed to treat patients with mesial temporal lobe epilepsy (MTLE). OBJECTIVE: To determine the volume and impact of temporal lobe infarction after retractorless transsylvian SAH (en bloc resection of the hippocampus) that have not been reported. METHODS: A retrospective analysis of patients treated with retractorless transsylvian SAH. Infarctions were detected by magnetic resonance imaging (MRI) within the first week after the operation. Neuropsychological testing was performed preoperatively and 6 mo later. Seizure outcome was evaluated 2 yr after epilepsy surgery. RESULTS: Between 2010 and 2014, a total of 30 patients were included in this study. Analysis of postoperative MRI showed the following: (1) mean removal volume of the hippocampus-parahippocampus was 5.72 cm3, and (2) mean volumes of temporal and insular infarctions were 1.71 and 0.25 cm3, respectively. Twenty-five patients (83.3%) were free of disabling seizures (Engel class I) at 2 yr of outcome. Neuropsychological testing revealed improvement in Perceptual Organization Index (P = .036) and verbal paired associates II (P = .014) after the operation. Neither infarction volume nor removal volume was related to epilepsy outcome in linear regression model. CONCLUSION: Transsylvian SAH has comparable seizure outcomes but bears inherent risks of vasospasm/vascular injury. Immediate postoperative small infarction volume around resection cavity or along surgical corridor was noticed after retractorless transsylvian SAH, which did not cause neuropsychological deteriorations, in contrast to previous study with the use of self-sustaining rigid retraction system. Further study should be performed to compare procedure-related infarctions and their impacts on neuropsychological outcomes in different selective approaches.

Pretemporal transcavernous transtentorial approach for left pontine glioma.

A 39-year-old man, who had a history of spinal myxopapillary ependymoma with cerebrospinal seeding status post twice operations and radiation therapy, presented with aggravating headaches, diplopia, dysphagia, and unsteady gait for 2 weeks. The brain MRI revealed a parenchymal lesion at the left aspect of the pons, about 2.8 × 2.3 × 3.2 cm3. The patient underwent a pretemporal transcavernous transtentorial approach for tumor removal. The pathological report showed an anaplastic astrocytoma. In this approach, a wider surgical corridor was obtained by opening the Meckel's cave and cutting the tentorium, via which a safe entry point into the pons could be determined with neuromonitoring. In the authors' opinion, this approach is safe and effective in selected ventrolateral pontine gliomas. The video can be found here: https://youtu.be/sUt-9QFGgCI.

Pretemporal trans-Meckel's cave transtentorial approach for large petroclival meningiomas.

OBJECTIVE Despite the advances in skull base techniques, large petroclival meningiomas (PCMs) still pose a challenge to neurosurgeons. The authors' objective of this study was to describe a pretemporal trans-Meckel's cave transtentorial approach for large PCMs and to report the surgical outcomes. METHODS From 2014 to 2017, patients harboring large PCMs (> 3 cm) and undergoing their first resection via this procedure at the authors' institute were included. In combination with pretemporal transcavernous and anterior transpetrosal approaches, the trans-Meckel's cave transtentorial route was created. Surgical details are described and a video demonstrating the procedure is included. Retrospective review of the medical records and imaging studies was performed. RESULTS A total of 18 patients (6 men and 12 women) were included in this study, with mean age of 53 years. The mean sizes of the preoperative and postoperative PCMs were 4.36 cm × 4.09 cm × 4.13 cm (length × width × height) and 0.83 cm × 1.08 cm × 0.75 cm, respectively. Gross-total removal was performed in 7 patients, near-total removal (> 95%) in 7 patients, and subtotal removal in 4 patients (> 90% in 3 patients and > 85% in 1 patient). There were no surgical deaths or patients with postoperative hemiplegia. Surgical complications included transient cranial nerve (CN) III palsy (all patients, resolved in 3 months), transient CN VI palsy (2 patients), CN IV palsy (3 patients, partial recovery), hydrocephalus (3 patients), and CSF otorrhea (1 patient). Temporal lobe retraction-related neurological deficits were not observed. CONCLUSIONS A pretemporal trans-Meckel's cave transtentorial approach offers large surgical exposure and multiple trajectories to the suprasellar, interpeduncular, prepontine, and upper-half clival regions without overt traction, which is mandatory to remove large PCMs. To unlock Meckel's cave where a large PCM lies abutting the cave, pretemporal transcavernous and anterior transpetrosal approaches are prerequisites to create adequate exposure for the final trans-Meckel's cave step.

Gamma Knife surgery for clival epidural-osseous dural arteriovenous fistulas.

OBJECTIVE Clival epidural-osseous dural arteriovenous fistula (DAVF) is often associated with a large nidus, multiple arterial feeders, and complex venous drainage. In this study the authors report the outcomes of clival epidural-osseous DAVFs treated using Gamma Knife surgery (GKS). METHODS Thirteen patients with 13 clival epidural-osseous DAVFs were treated with GKS at the authors' institution between 1993 and 2015. Patient age at the time of GKS ranged from 38 to 76 years (median 55 years). Eight DAVFs were classified as Cognard Type I, 4 as Type IIa, and 1 as Type IIa+b. The median treatment volume was 17.6 cm3 (range 6.2-40.3 cm3). The median prescribed margin dose was 16.5 Gy (range 15-18 Gy). Clinical and radiological follow-ups were performed at 6-month intervals. Patient outcomes after GKS were categorized as 1) complete improvement, 2) partial improvement, 3) stationary, and 4) progression. RESULTS All 13 patients demonstrated symptomatic improvement, and on catheter angiography 12 of the 13 patients had complete obliteration and 1 patient had partial obliteration. The median follow-up period was 26 months (range 14-186 months). The median latency period from GKS to obliteration was 21 months (range 8-186 months). There was no intracranial hemorrhage during the follow-up period, and no deaths occurred. Two adverse events were observed following treatment, and 2 patients required repeat GKS treatment with eventual complete obliteration. CONCLUSIONS Gamma Knife surgery offers a safe and effective primary or adjuvant treatment modality for complex clival epidural-osseous DAVFs. All patients in this case series demonstrated symptomatic improvement, and almost all patients attained complete obliteration.

How Does Brainstem Involvement Affect Prognosis in Patients with Limited Brain Metastases? Results of a Matched-Cohort Analysis.

OBJECTIVE: Although brainstem metastases are thought to portend an inferior prognosis compared to non-brainstem brain metastases, there is limited evidence to support this claim, particularly in the modern radiosurgical era. METHODS: We collected the clinical data for 500 patients with brain metastases treated at our institution with stereotactic radiosurgery (SRS). All patients received SRS to at least one brain metastasis, and all brainstem metastases underwent SRS. After propensity score matching, clinical characteristics and overall survival were calculated and compared between groups. RESULTS: Three hundred sixteen patients with brain metastases were analyzed after matching (143 with brainstem involvement and 173 without). Patients with brainstem metastases lived shorter after first SRS than patients without brainstem metastases did (median 4.4 and 6.5 months, respectively; P = 0.01), and they were more likely to have received whole brain irradiation (P = 0.003). Patients with a single metastasis did not survive longer than patients with multiple brain metastases if there was brainstem involvement (P = 0.45). The incidence of new extracranial disease and severe toxicity after SRS did not differ between groups. CONCLUSIONS: The survival of patients with brain metastases is inferior after a metastatic lesion develops within the brainstem, despite favorable local control with brainstem SRS. The brainstem location should be considered a negative prognostic factor for survival after SRS, and it could result from the eloquence of this location. Future research could identify the clinically life-limiting component of brainstem metastases.

Fluorescence-assisted visualization of facial nerve during mastoidectomy: A novel technique for preventing iatrogenic facial paralysis.

OBJECTIVE: Mastoidectomy can be risky due to the chance of iatrogenic facial nerve dysfunction. Avoiding injuries to the mastoid segment of the facial nerve is mandatory when drilling the bone. With advancements in intraoperative near-infrared indocyanine green (ICG) video angiography, we describe the application of a novel fluorescent guidance technique during mastoidectomies to identify the facial canal with safety. METHODS: Mastoidectomies were performed as the key step in the presigmoid, petrosal or translabyrinthine approaches in 16 patients with different pathologies located at the cerebellopontine angle or petroclival region. After the facial canal was drilled to paper thin, ICG was injected via the central venous catheter. Compared with the dark bony portion, the vessels inside the vasa nervorum were highlighted as a result. The fluorescence guides the operator through the course of the facial nerve and facilitates opening of the internal auditory canal and the dissection of tumors. RESULTS: All 16 facial nerves were recognized during mastoidectomies under fluorescence guidance for varied periods of enhancing time (range, 23-50s). In all, one to four attempts after repeated drilling works to enhance the facial nerve were required before these nerves could be clearly seen. The tumor resection procedure yielded the following results: grossly total removal in seven patients, near total removal in five, and subtotal removal in three. Complete obliteration of a giant vertebral artery aneurysm in one patient was seen in the follow-up angiogram. The post-mastoidectomy facial nerve function, examined by triggered EMG, was preserved in all 16 patients, and no patients had postoperative facial palsy worse than House-Brackmann grade IV after 6 months of follow-up. CONCLUSION: With this novel technique, the course of the facial nerve can be confirmed during mastoidectomy, which reduces the possibility of iatrogenic facial nerve dysfunction. This fluorescence technique is especially helpful in establishing confidence and shortening the learning curve for beginners at mastoidectomies.

Rhabdoid glioblastoma: a recently recognized subtype of glioblastoma.

BACKGROUND: Rhabdoid glioblastoma is a rare type of recently described malignant brain tumor. It is characterized by a glioblastoma associated with rhabdoid components. METHODS: Here we report two cases of rhabdoid glioblastoma and a brief literature review. The first patient was a 19-year-old boy who initially presented with a foul-smelling odor and progressive right-side weakness. The second case was a 29-year-old male patient who presented only with a severe headache. RESULTS: Both of these patients were young, and the disease progression was quick despite optimal treatment. CONCLUSION: The diagnosis of rhabdoid glioblastoma was confirmed after microscopic and immunohistochemical findings.

An easy adjustable method of ectatic vertebrobasilar artery transposition for microvascular decompression.

BACKGROUND: Microvascular decompression (MVD) of trigeminal neuralgia (TN) or hemifacial spasm (HFS) caused by an elongated, tortuous or enlarged vertebral or basilar artery has a higher rate of incomplete cure. OBJECTIVE: We used an easily applied and adjustable method of vertebrobasilar artery transposition and fixation to improve the immediate surgical outcome of MVD of TN or HFS due to compression by an ectatic vertebrobasilar artery system. METHODS: Vertebral or basilar artery transposition was performed using the vascular sling with a strip of unabsorbable dural tape. The vertebrobasilar artery-sling complex was then fixed to the dura over the petrous bone by aneurysm clip through the dural bridge. The direction and angle of traction on the vertebrobasilar artery was adjustable using different lengths of clip or the horizontal level of the dural bridge. RESULTS: The sling and clip fixation method has been applied in 7 cases of MVD associated with vertebral or basilar artery compression. All 3 patients with TN and one with HFS had total remission of symptoms right after the procedure; one patient was completely free of spasm within 1 week after MVD and one had achieved 80% improvement of spasm in his last clinical visit 3 months after MVD. There was no major surgical complication in these 7 patients. Surprisingly, refractory hypertension was unexpectedly cured in one patient with TN following the procedure. CONCLUSION: The vertebrobasilar artery transposition and fixation method used in the present study provided surgeons an easy and adjustable way to perform MVD safely and effectively.

Telovelar approach for choroid plexus papilloma in the foramen of Luschka: a safe way using a neuromonitor.

BACKGROUND: Tumors located in the 4th ventricle are always challenging to neurosurgeons, especially tumors that extend to the cerebellopontine (CP) angle by the foramen of Luschka. Recent advances in microsurgical technique, including the neuromonitor and brainstem mapping, facilitate the surgical resection of tumors located in the foramen of Luschka. Herein, we present the use of the telovelar approach to access a choroid plexus papilloma within the right foramen of Luschka. CASE PRESENTATION: A 28-year-old female presented with a history of sudden onset pulsatile headache and syncope twice without prodrome. The brain MRI revealed a 4th ventricular tumor deviated to the right foramen of Luschka and extending to the CP angle, 2.2 cm in diameter. There was no secondary hydrocephalus due to the patent foramen of Magendie and left foramen of Luschka. The patient underwent suboccipital craniotomy and C1 laminectomy with a telovelar approach. The right tonsil was elevated and teal chloride was incised from the foramen of Magendie to the telovelar junction. The tumor was centrally decompressed, and the margin was gently dissected from the brainstem and cerebellum peduncles. Functions of the facial, cochlear, glossopharyngeal, vagus, and hypoglossal nerves and nuclei were monitored. Mapping of the facial nucleus, ambiguous nucleus, and hypoglossal nucleus was also done. Total tumor removal was achieved and the histology showed choroid plexus papilloma. No functional neurological disorientation was observed after surgery. CONCLUSION: The report demonstrated a safe and effective surgical approach to the foramen of Luschka. The approach yielded a better view of the foramen of Luschka laterally, and up to the middle cerebellar peduncle superiorly. Also, it minimized neural damage, and preserved the function of the cranial nerves and nucleus.

The effect of betel quid and cigarette on multistate progression of oral pre-malignancy.

BACKGROUND: Although the effect of betel quid chewing and smoking on oral cancer has been well documented, both influences, dose and duration during life time, on multistate progression of oral pre-malignancy are hardly addressed. METHODS: By recruiting a group of male chewers from different occupation groups, we modeled the effects of both duration and quantity of betel quid chewing and smoking on annual incidence rate of developing leukoplakia and average dwelling times (ADTs) staying in leukoplakia and erythroleukoplakia. RESULTS: The annual incidence rate (per year) of leukoplakia was estimated as 0.35% (95% CI: 0.22-0.48%). The ADTs were 24 years for leukoplakia and 7 years for erythroleukoplakia. Annual incidence rate of leukoplakia with high consumption and long duration of betel quid and smoking was higher. Both quantity and duration of smoking and betel quid chewing play minor roles in the influence of ADT. The risks of developing oral cancer after 20 years of follow-up were 42.2% for leukoplakia and 95.0% for erythroleukoplakia. CONCLUSION: The effects of betel quid chewing and smoking on multistate progressions between oral pre-malignancies were elucidated. These results can be applied to predict long-term risk of malignant transformation varying with different duration and quantity of betel quid and cigarette.

Dose-response relationships of oral habits associated with the risk of oral pre-malignant lesions among men who chew betel quid.

Betel quid, cigarettes and alcohol are well-recognized risk factors for oral cancer. However, the combined effect of the frequency and duration of these oral habits on the risk for developing oral pre-malignancies among betel quid users has not been fully addressed. In this study, an oral screening programme for men chewing betel quid was carried out by well-trained dentists for early detection of oral pre-malignancy lesions. Using generalized logit model and proportional odds model, we found that, compared with the occasional user, the adjusted odds ratios of developing leukoplakia for men chewing one to 10 pieces of betel quid, 11-20 pieces, and more than 20 pieces per day were estimated as 2.14 (95% confidence interval [CI] 1.62-2.81), 2.99 (95% CI 2.06-4.27), and 5.37 (95% CI 3.76-7.47), respectively. The corresponding figures for erythroleukoplakia were 3.69 (95% CI 1.55-8.79), 13.78 (95% CI 5.76-32.98), and 36.64 (95% CI 15.94-84.16), respectively. Similar results were found while the duration was considered. The dose-response relationships were not as noteworthy for cigarette and alcohol drinking.