Interhemispheric Transcingulate Sulcus Approach to Deep-Seated Medial Frontal and Parietal Lesions-Fiber Dissection Study With Illustrative Cases

BACKGROUND

Surgery for lesions located in the medial frontal and parietal lobes can be quite challenging for neurosurgeons because of morbidities that may arise from damage to critical midline structures or intact neural tissue that need to be crossed to reach the lesion. In our anatomic studies, the cingulate sulcus was observed as an alternative access route for lesions located in medial frontal and parietal lobes.

OBJECTIVE

To explain the microsurgical anatomy of the medial hemisphere and cingulate sulcus and to demonstrate the interhemispheric transcingulate sulcus approach (ITCSA) with 3 clinical cases.

METHODS

Five formalin-fixed brain specimens, which were frozen at -18 °C for at least 2 weeks and then thawed under tap water, were gradually dissected from medial to lateral. Diffusion fiber tracking performed using DSI Studio software in data was provided by the Human Connectome Project. Clinical data of 3 patients who underwent ITCSA were reviewed.

RESULTS

Cingulate sulcus is an effortlessly identifiable continuous sulcus on the medial surface of the brain. Our anatomic dissection study revealed that the lesions located in the deep medial frontal and parietal lobes can be reached through the cingulate sulcus with minor injury only to the cingulum and callosal fibers. Three patients were treated with ITCSA without any neurological morbidity.

CONCLUSION

Deep-seated lesions in the medial frontal lobe and parietal lobe medial to the corona radiata can be approached by using microsurgical techniques based on anatomic information. ITCSA offers an alternative route to these lesions besides the known lateral transcortical/transsulcal and interhemispheric transcingulate gyrus approaches.

Surgical Treatment of Trochlear Nerve Schwannomas: Case Series and Systematic Review

BACKGROUND AND OBJECTIVE

Cranial nerve schwannomas almost always arise from sensory or mixed nerves. Motor cranial nerves, such as the trochlear nerve, are rarely associated with schwannomas. No consensus has yet been made for surgical intervention because of the low number of reported cases of trochlear nerve schwannomas. This study comprises a systematic review of the literature and our experience for surgically treated trochlear nerve schwannomas.

METHODS

Three databases (Web of Science, PubMed, and Cochrane Library) were searched without date restrictions. Studies were included if they were published in the English literature and presented patients of any age who underwent surgical treatment for trochlear schwannoma. Data extracted from the included studies were combined with our experience.

RESULTS

Forty-one studies, presenting 43 patients, met the inclusion criteria. The total number of patients was 45 after our experience was added. The most common symptoms were diplopia (62.2%), headache (46.7%), and motor weakness (37.8%). Mean age during the diagnosis was 45.1 years. Although the subtemporal transtentorial approach (n = 14) is the most preferred method, its application has decreased in recent years. In the last decade, the lateral suboccipital approach (n = 11) has gained popularity. Residual postoperative trochlear nerve deficit was detected in 81% of patients. The probability of neurologic deficit was not statistically associated with tumor volume (P = 0.914), location (P = 0.669), or resection rate (P = 0.554).

CONCLUSIONS

Although trochlear schwannomas are rare and their treatment involves challenges, total resection with the proper approach provides the most desirable results.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

Extreme lateral lumbar interbody fusion surgery with a robot-assisted system in a swine model

AIM

To evaluate the technical aspects of the Da Vinci Xi Surgical System in minimally invasive extreme lateral lumbar interbody fusion (XLIF) surgery in a swine model.

MATERIAL AND METHODS

Endoscopic discectomy and XLIF cage insertion were performed using a robot-assisted system. The time taken and the pros and cons of each steps were recorded.

RESULTS

A total of 4 ports were used for the surgical access; one for the camera, two for bipolar forcepses, and one auxiliary port for modified discectomy. Punch and curette were used for discectomy. The cage was inserted through the auxiliary port. Cage position was manipulated and checked by using the C-arm fluoroscopy. The operative time was 80 minutes. No complications or cage malposition was noted throughout the procedure.

CONCLUSION

This study shows that the robot-assisted XLIF approach is safe and feasible, and helps to protect the neurovascular structures. Moreover, a high image quality was also obtained during the procedure.

Relationship between subarachnoid and central canal hemorrhage and spasticity: A first experimental study

Objective: Spastic disorders are considered as important cerebral complications of subarachnoid hemorrhage (SAH). However, there has been no research concerning the pathophysiological mechanism of its link with the spinal cord. The present study aimed to assess the relationship between the development of spasticity and neuronal degeneration after SAH and increase in spinal cord pressure after central canal hemorrhage (CCH).Participants: Twenty-three rabbits were included.Outcome measures: Of all rabbits, 5, 5, and 13 were allocated in the control, SHAM and study groups, respectively. Moreover, 1 cc of saline and 1 cc of autologous arterial blood were injected into the cisterna magna of the SHAM and study groups, respectively. The Muscle spasticity tension values (MSTVs) were determined according to the modified Ashworth scale. Degenerated neuron densities (DND) in the gray matter (GM) of each animal's spinal cord were stereologically calculated.Results: The average MSTV of each group was as follows: control group (n = 5) 2; SHAM group (n = 5) 3-5; and study group (n = 13) 8-10. The DND values of the spinal cord of each group were as follows: control group, 2 ± 1/mm³; SHAM group, 12 ± 3/mm³; and study group, 34 ± 9/mm³. Results showed an important linear relationship between the MSTVs and the DND of the spinal cord (P < 0.001).Conclusion: Spasticity may be attributed to other causes such as ischemic neurodegenerative process that develops after spinal SAH and the de-synchronization of the flexor-extensor muscles due to the spontaneous discharge of interneuronal structures, which are crossed within the spinal cord owing to the build-up of pressure after CCH.

Cervical Venous Vascular Anatomy for Ventriculoatrial Shunt Applications: Anatomical Study and Surgical Approach Recommendation

AIM

Ventriculoatrial (VA) shunt applications are performed when applying ventriculoperitoneal shunt is not suitable. However, due to variations in the venous anatomy of the neck region and difficulties with venous vascular dissection, this procedure involves the risk of complications. This study aimed to develop an approach for atrial application of VA shunts after revealing the venous anatomy with facial and cervical anatomical dissections.

MATERIAL AND METHODS

Five cephalic cadavers were used in the study. Facial and cervical regions of the cephalic cadavers were examined with layer by layer anatomical dissection. Venous angiography and ultrasonography were performed to obtain additional data on the cervical venous vascular anatomy. Subsequently, we developed an approach for atrial catheter applications.

RESULTS

No anatomical variations were detected in the dissections. The common facial vein, which was formed by the facial vein and retromandibular vein, was observed to drain into the internal jugular vein. As a result of dissections and examinations, an incision approximately 2 cm below the mandible, extending from the projection of the submandibular notch to the trace of the angulus mandible, was considered adequate to expose the common facial vein for atrial catheter insertion.

CONCLUSION

The approach described in our study is appropriate for the application of an atrial catheter for VA shunts. Revealing the venous anatomy with examinations contributes to the success of the operation.

A follow-up study on outcomes of endoscopic transsphenoidal approach for acromegaly

OBJECTIVE

A thorough follow-up study in which the same clinic presents the change in the surgical outcomes of acromegaly over the years, is still lacking in the endoscopic era. In this study, we intended to evaluate the clinical characteristics, radiological features, surgical and late remission rates of newly diagnosed acromegaly patients treated in our clinic between 2014 and 2019 in order to delineate the surgical remission status according to radiological, microscopic, and hormonal features. As a follow-up to our initial report, we also aimed to display the change of surgical remission rates over time in a tertiary center.

METHODS

A total of newly diagnosed 106 patients with acromegaly, who underwent endoscopic endonasal trans-sphenoidal approach (EETSA) in the last five years were retrospectively analyzed and presented in this study. Medical records were reviewed in clinical, biochemical, pathological, and radiological aspects to assess the relationship of preoperative patient characteristics with surgical remissions.

RESULTS

The percentages of the giant pituitary adenomas (≥4 cm), adenomas with suprasellar extension and adenomas with surgically proven invasion of the cavernous sinus in the present series were 13%, 34%, and 20%, respectively. Gross total resection was achieved in 80% of the patients. Surgical remission and late remission rates were 66% and 86%, respectively. Nine (9.4%) patients in our current report had postoperative transient diabetes insipidus. The mean follow-up period in this series was 36.1 ± 18.1 (range 12-59) months.

CONCLUSION

The presented surgical results are considerably better than our published initial series of acromegaly patients operated in the same clinic between 2007 and 2014. The improvement in surgical remission rate support a positive surgical volume - remission rate relationship for acromegaly in the era of endoscopic endonasal skull base approaches. One possible factor for better results may be the increasing surgical experience in EETSA, which follows a trend toward gradual improvement of long-term late remissions via a multidisciplinary approach.

Neurosurgical Practice During Coronavirus Disease 2019 (COVID-19) Pandemic

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly contagious life-threatening condition with unprecedented impacts for worldwide societies and health care systems. Since the first detection in China, it has spread rapidly worldwide. The increased burden has substantially affected neurosurgical practice and intensive modifications have been required in surgical scheduling, inpatient and outpatient clinics, management of emergency cases, and even in academic activities. In some systems, nonoverlapping teams have been created to minimize transmission among health care workers. In cases of a massive burden, neurosurgeons may need to be reassigned to COVID-19 wards, or teams from other regions may need to be sent to severely affected areas. Recommendations are as following. In outpatient practice, if possible, appointments should be undertaken via telemedicine. All staff assigned to the non-COVID treatment unit should be clothed in level 1 personal protective equipment. If possible, postponement is recommended for operations that do not require urgent or emergent intervention. All patients indicated for surgery must receive COVID-19 screening, including a nasopharyngeal swab and thorax computed tomography. Level 2 protection measures are appropriate during COVID-19-negative patients' operations. Operations of COVID-19-positive patients and emergency operations, in which screening cannot be obtained, should be performed after level 3 protective measures. During surgery, the use of high-speed drills and electrocautery should be reduced to minimize aerosol production. Screening is crucial in all patients because the surgical outcome is highly mortal in patients with COVID-19. All educational and academic conferences can be undertaken as virtual webinars.

Early cranioplasty associated with a lower rate of post-traumatic hydrocephalus after decompressive craniectomy for traumatic brain injury

BACKGROUND

Post-traumatic hydrocephalus (PTH) is one of the primary complications during the course of traumatic brain injury (TBI). The aim of this study was to define factors associated with the development of PTH in patients who underwent unilateral decompressive craniectomy (DC) for TBI.

METHODS

A total of 126 patients, who met the inclusion criteria of the study, were divided into two groups: patients with PTH (n = 25) and patients without PTH (n = 101). Their demographic, clinical, radiological, operative, and postoperative factors, which may be associated with the development of PTH, were compared.

RESULTS

Multivariate logistic regression analysis revealed that cranioplasty performed later than 2 months following DC was significantly associated with the requirement for ventriculoperitoneal shunting due to PTH (p < 0.001). Also, a significant unfavorable outcome rate was observed in patients with PTH at 1-year follow-up according to the Glasgow Outcome Scale-Extended (p = 0.047).

CONCLUSIONS

Our results show that early cranioplasty within 2 months after DC was associated with a lower rate of PTH development after TBI.

Comparative Volumetric Analysis of the Brain and Cerebrospinal Fluid in Chiari Type I Malformation Patients: A Morphological Study

BACKGROUND

Chiari Type I malformation (CM-I) is defined as the migration of cerebellar tonsils from the foramen magnum in the caudal direction and is characterized by the disproportion of the neural structures. The aim of this study was to investigate the brain volume differences between CM-I patients and normal population using a comparative volumetric analysis.

METHODS

140 patients with CM-I and 140 age- and sex-matched healthy controls were included in this study. The magnetic resonance imaging (MRI) data of both groups were analyzed with an automated MRI brain morphometry system. Total intracranial, cerebrum, cerebellum, brainstem, cerebrospinal fluid (CSF), and lateral ventricle volumes as well as cerebrum and cerebellum gray/white matter (GM/WM) volumes were measured. Statistical analysis was performed.

RESULTS

Both total CSF and lateral ventricle volumes and volume percentages (Pct) were found significantly higher in CM-I patients compared to the control group. However, there were significant decreases in cerebrum and cerebellum volume Pct in CM-I patients. Although there were no significant differences in cerebrum WM volumes and volume Pct, cerebrum GM volume Pct were found to be significantly lower in CM-I patients.

CONCLUSIONS

Revealing the increased CSF and lateral ventricle volume, and volume Pct supported concomitant ventricular enlargement and hydrocephalus in some CM-I patients. Decreased cerebrum GM volume Pct compared to the control group might be the underlying factor of some cortical dysfunctions in CM-I patients.

Effect of Vasa Vasorum on Basilar Artery Vasospasm Following Subarachnoid Hemorrhage

BACKGROUND

A well-documented association exists between the vasa vasorum and vasopathologies, including atherosclerosis. However, information on the role of the vasa vasorum during vascular degenerative changes of vasospasm after subarachnoid hemorrhage (SAH) is insufficient.

METHODS

In this study, 34 rabbits were divided into 3 groups: basal group (N = 8), sham group (N = 8), and SAH group (N = 18). Experimental SAH was formed using a double-injection model. During follow-up, the neurologic status of the rabbits was observed. All rabbits were euthanized after 2 weeks, and the vasopathologic degeneration was categorized as normal, mild, moderate, and severe according to the changes in the basilar arteries. The numbers, locations, and spasms of the vasa vasorum and their relation to the vasodegenerative changes of the basilar artery were investigated.

RESULTS

The basilar arteries were graded as normal in the basal and sham groups. In the SAH group, 6 rabbits had mild, 7 had moderate, and 5 had severe degeneration. Neurologic deficits were prominent in the SAH group, and deficit grades correlated with vascular degeneration. The number of the vasa vasorum were significantly higher in the SAH group, and an enhanced formation of the vasa vasorum was noted in which severe degenerative changes were present. Moreover, the vasospasm index of the vasa vasorum, which increased with the aggravation of vascular degenerative changes, was significantly higher in the SAH group.

CONCLUSIONS

The vasa vasorum and their vasospasm play a crucial role in the pathogenesis of basilar artery degeneration in the vasospasm following SAH.

Predictive Factors for Rathke's Cleft Cyst Consistency

OBJECTIVE

Rathke's cleft cysts (RCCs) may have various anatomic, clinical, and radiologic characteristics, which may be related to their differences in texture or consistency. The purpose of the study was to investigate RCCs based on consistency.

METHODS

We retrospectively reviewed 25 cases of patients with RCCs who underwent endoscopic endonasal transsphenoidal surgery between 2008 and 2018. Cases were divided into 3 types based on cyst consistency: fluid (serous) or type A (n = 4); semi-fluid (mucoid) or type B (n = 17); and non-fluid (caseous) or type C (n = 4). Demographic, clinical, radiologic, and surgical characteristics for each group were analyzed.

RESULTS

All type A RCCs (100%) had visual impairment. The mean age (42.8 ± 13 years) and cyst volume (2442.5 ± 533.6 mm³) were higher in these patients. T1-weighted images were hypointense and T2-weighted images were hyperintense on magnetic resonance imaging. Type B RCCs were more frequently encountered (68%). Although headache was the most common (82.3%) symptom, endocrine disorders were also prevalent (52.9%). T1-weighted images were typically isointense or hyperintense on magnetic resonance imaging. Type C RCCs had the youngest patient population (30.3 ± 10.2 years) and T2-weighted images were predominantly hypointense in this group.

CONCLUSIONS

The proposed novel consistency classification of RCCs will provide a practical tool for more accurately estimating the nature of the pathology, because each type has its own specific characteristics. Furthermore, the new classification of RCCs may aid in planning a consistency-specific surgery.

Effects of pycnogenol on ischemia/reperfusion-induced inflammatory and oxidative brain injury in rats

BACKGROUND

Ischemia/reperfusion (I/R) injury results from the onset of re-circulation following a perfusion deterioration period in the tissues, resulting in more damage than that caused by perfusion deterioration. This study aimed to determine the effects of pycnogenol on I/R injury in rat brain tissues.

METHODS

Eighteen albino Wistar rats were divided into three groups: I/R injury (IR, n = 6) group; I/R injury + pycnogenol (IR + P, n = 6) group; and sham group (SG, n = 6). After 30 min of transient ischemia, 24 h of reperfusion was achieved in the IR and IR + P groups. Surgical dissection, except for transient ischemia, was performed in SG. Next, histopathological and biochemical investigations were performed on brain tissues. Malondialdehyde (MDA), reduced glutathione (GSH), and glutathione peroxidase (GPO) were analyzed as oxidative stress markers; IL-1β and TNF-α were analyzed as inflammatory stress markers in biochemical tests.

RESULTS

Histopathological examination revealed normal morphology in SG and diffuse cortex damage with edema, vasopathology, and inflammatory cell infiltration in the IR group. The IR + P group showed less cortex damage, edema, and vasopathology than the IR group. The MDA, IL-1β, and TNF-α levels were significantly higher in the IR group than those in the SG group. The values of same markers for the IR + P group were significantly lower than the IR group. The GSH and GPO levels were significantly decreased with IR damage, but PYC treatment showed significant improvement in the levels.

CONCLUSION

This study showed that the administration of pycnogenol ameliorated brain damage after I/R injury by reducing oxidative and inflammatory damage in the rat brain.

Surgical Management of Sphenoid Sinus Lateral Recess Cerebrospinal Fluid Leaks: A Single Neurosurgical Center Analysis of Endoscopic Endonasal Minimal Transpterygoid Approach

OBJECTIVE

To review the results of sphenoid sinus lateral recess (SSLR) cerebrospinal fluid (CSF) leaks treated with the endoscopic endonasal minimal transpterygoid approach (EEMTPA) and to discuss the surgical technique and outcomes.

METHODS

We performed a retrospective analysis of 13 cases who underwent SSLR CSF leak repair through the EEMTPA in our clinic between September 2008 and December 2017. Demographic and etiological features with reconstruction and surgical outcomes were examined. Mean follow-up time was 6.1 years.

RESULTS

In regard to etiology, the SSLR CSF leaks included 9 patients with spontaneous, 2 patients with traumatic, and 2 with iatrogenic causes. CSF leak was at the left lateral recess in 8 cases and at right lateral recess in 5 cases. Nine patients had empty sella syndrome, and 11 patients had meningoencephaloceles in addition to SSLR CSF leaks. All patients underwent surgery through the EEMTPA, and a multilayer closure with tissue overlay grafts were used for reconstruction. A pedicled nasoseptal flap and/or pedicled middle turbinate flap were applied to the area of the leak in all cases. One patient had a persistent CSF leak and another had recurrence, both of which required revision surgery. Our overall success rate was 100%.

CONCLUSIONS

EEMTPA is a safe and effective method that can be used to treat challenging pathologies at the SSLR, including CSF leaks accompanying meningoencephaloceles. Furthermore, the success rate of EEMTPA for SSLR CSF leaks can be increased by applying endoscopic skull base reconstruction techniques such as the pedicled nasoseptal flap and pedicled middle turbinate flap.

Computerized Tomography-Guided Stereotactic Biopsy of Intracranial Lesions: Report of 500 Consecutive Cases

AIM

Computed tomography (CT)-guided stereotactic brain biopsy has been performed in our clinic since March 1998. In this prospective study, we examined the patient data undergoing stereotactic biopsy and the results of biopsies in 500 consecutive patients.

MATERIAL AND METHODS

Between the dates of March 1998 and January 2015, CT-guided stereotactic biopsies were performed by using the Leksell stereotactic frame system (Elekta Instruments EU, Sweden) in 500 patients. A total of 512 procedures were performed in patients consisting of 184 females (36.8%) and 316 males (63.2%), ages ranging from 3 to 81 years (mean 50.40±16.67).

RESULTS

Conclusive histopathological diagnosis was not achieved in 17(3.3%) of 512 procedures. Of the others, 173 (33.8%) were high-grade gliomas, 103 (20.1%) were low-grade gliomas, 36 (7%) were malignant lymphomas, 34 (6.6%) were other types of brain tumors, 82 (16%) were metastasis and 67 (13.1%) were non-tumoral lesions. Complications were occurred in ten cases: 3 tumoral bleedings, 2 hypertensive cerebral hematomas, 2 peroperative convulsions, 1 epidural hematoma, 1 myocardial infarction and 1 brain edema. The patients who developed myocardial infarction and hypertensive thalamic hematoma died. The mortality was 0.4% and morbidity was 1.6% in 512 procedures.

CONCLUSION

CT-guided stereotactic biopsy is a reliable and a safe procedure in cases with intracranial lesions when histopathological diagnosis is required for the appropriate treatment.