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Axial MRI before and after surgery in patient 9. Axial MRI with contrast enhancement (a before surgery, b after surgery) shows that most of the vestibular schwannoma has been internally decompressed (white arrow)
Source publication
Background:
Hearing preservation in patients with vestibular schwannomas remains difficult by microsurgery or radiosurgery.
Method:
In this study, awake surgery via the retrosigmoid approach was performed for vestibular schwannomas (volume, 11.6 ± 11.2 ml; range, 1.3-26.4 ml) in eight consecutive patients with preoperative quartering of pure ton...
Citations
... In addition, some acute symptoms in the present study might have occurred due to differences in patients' pathological backgrounds and/or surgical procedures. All of the participants had undergone awake craniotomy, which uses intraoperative stimulation mapping to maximize the extent of resection while avoiding severe deficits (21,22). ...
Objectives
Hyper- and hyposensitivity in multiple modalities have been well-documented in subjects with autistic spectrum disorder (ASD) but not in subjects with acquired brain injury (ABI). The purpose of this study was to determine whether subjects with ABI experience altered sensory processing in multiple sensory modalities, and to examine the relationships between impaired sensory processing and the emotional state.
Methods and procedures
Sixty-eight patients with brain or spinal cord tumors participated in the study. Cognitive ability and emotional function were tested, and subjective changes were evaluated in two directions (hyper- and hyposensitivity) and five modalities (visual, auditory, tactile, olfactory, and gustatory) at two time points (after disease onset and after surgery).
Results
One-fifth of the participants complained of hypersensitivity in the visual domain, and a similar proportion complained of hyposensitivity in the auditory and tactile domains. Additionally, one-third of participants complained of two or more sensory abnormalities after disease onset. A hierarchical regression analysis indicated that auditory and tactile sensory changes predicted a depressive state.
Conclusion
In conclusion, multimodal sensory changes occurred in patients with brain tumors, manifesting as hyper- or hyposensitivity. Sensory changes might be related to depressive state, but the results were inconclusive.
... Awake craniotomy is usually performed to maximize resection of tumors near the eloquent area [3,4]. It can reduce anesthetic interference with brain mapping [5]. Awake craniotomy for posterior fossa surgery reminds a number of significant challenges for the anesthesiologist. ...
Background:
The auditory brainstem implant (ABI) is a significant treatment to restore hearing sensations for neurofibromatosis type 2 (NF2) patients. However, there is no ideal method in assisting the placement of ABIs. In this case series, intraoperative cochlear nucleus mapping was performed in awake craniotomy to help guide the placement of the electrode array.
Case summary:
We applied the asleep-awake-asleep technique for awake craniotomy and hearing test via the retrosigmoid approach for acoustic neuroma resections and ABIs, using mechanical ventilation with a laryngeal mask during the asleep phases, utilizing a ropivacaine-based regional anesthesia, and sevoflurane combined with propofol/remifentanil as the sedative/analgesic agents in four NF2 patients. ABI electrode arrays were placed in the awake phase with successful intraoperative hearing tests in three patients. There was one uncooperative patient whose awake hearing test needed to be aborted. In all cases, tumor resection and ABI were performed safely. Satisfactory electrode effectiveness was achieved in awake ABI placement.
Conclusion:
This case series suggests that awake craniotomy with an intraoperative hearing test for ABI placement is safe and well tolerated. Awake craniotomy is beneficial for improving the accuracy of ABI electrode placement and meanwhile reduces non-auditory side effects.
... 6,19,37,[45][46][47][48] Two studies included tumor sizes in terms of volume rather than diameter. 49,50 Others reported tumor sizes based on the Koos grading system. [51][52][53] For our purposes, small tumors were defined as those with intracisternal diameters of 0 to 20 mm. ...
... Three authors included both subtotal and gross total resections in their reported data, 22,28,43 5 included data from gross total resections, 13,26,27,47,52 while 2 studies included only cases involving subtotal resection. 44,49 In addition, VS can be bilateral and aggressive. These are caused by a deletion on chromosome 22q11, which codes for tumor suppressor gene, Merlin. ...
Background:
Vestibular schwannomas (VS) are benign tumors derived from Schwann cells ensheathing the vestibulocochlear nerve. The retrosigmoid (RS) surgical approach is useful to resect tumors of multiple sizes while affording the possibility of preserving postoperative hearing.
Objective:
To conduct a systematic review of published literature investigating hearing preservation rates in patients who underwent the RS approach for VS treatment.
Methods:
The PubMed, Scopus, and Embase databases were surveyed for studies that reported preoperative and postoperative hearing grades on VS patients who underwent RS treatment. Hearing preservation rates were calculated, and additional patient demographic data were extracted. Tumor size data were stratified to compare hearing preservation rates after surgery for intracanalicular, small (0-20 mm), and large (>20 mm) tumors.
Results:
Of 383 deduplicated articles, 26 studies (6.8%) met eligibility criteria for a total of 2034 patients with serviceable preoperative hearing, for whom postoperative hearing status was evaluated. Aggregate hearing preservation was 31% and 35% under a fixed and random effects model, respectively. A mixed effects model was used to determine hearing preservation rates depending on tumor size, which were determined to be 57%, 37%, and 12% for intracanalicular, small, and large tumors, respectively. Significant cross-study heterogeneity was found (I2 = 93%, τ2 = .964, P < .01; Q = 287.80, P = < .001), with rates of hearing preservation ranging from 0% to 100%.
Conclusion:
Tumor size may have an effect on hearing preservation rates, but multiple factors should be considered. Discussion of a patient's expectations for hearing preservation is critical when deciding on VS treatment plans.
... There are a few case reports and case series on AC for posterior fossa lesions such as acoustic schwannoma to preserve the functions of lower cranial nerves especially seventh and eighth cranial nerves [12,13]. Shinoura et al. published a case series of eight cases of vestibular schwannoma where surgery was conducted after infiltration of local anesthetic agents at pin and incision sites along with surgical field block (infiltration). ...
... Shinoura et al. published a case series of eight cases of vestibular schwannoma where surgery was conducted after infiltration of local anesthetic agents at pin and incision sites along with surgical field block (infiltration). The degree of tumor resection after surgery was observed to be 86 ± 16%, and the values for preoperative and postoperative hearing were 53 ± 27 and 51 ± 21 dB, respectively [12]. They concluded that awake surgical resection of vestibular schwannomas helped preserving hearing and other cranial nerves functions. ...
... The most serious complications and their step-wise management are listed in Table 5. As per a previous study, the incidence of various complications during AC is approximately 16.5% [8], and in an approximately 6.4% of patients, mapping procedure could not be completed [12]. The reasons for failure include seizures, loss of cooperation due to severe somnolence or restlessness, and dysphasia [24]. ...
Purpose of Review
The purpose of this article is to review the current evidence on perioperative management for awake craniotomy (AC).
Recent Findings
With the advancement of diagnostic modalities, newer intraoperative monitoring technologies, and safer and shorter-acting anesthetic agents, the indications of AC are expanding beyond epilepsy surgery. Anesthesia techniques including asleep-awake-asleep and monitored anesthesia care are generally safe and without any serious side effects when performed by experienced providers; however, data regarding awake-awake-awake technique is limited. Currently, an α-2 agonist, dexmedetomidine, is gaining popularity both as a sole agent as well as an adjunct for AC as it provides analgesia with minimal respiratory depression and it minimally interferes with electrocorticography and cortical mapping. The use of dexmedetomidine allows reduction of opioid and propofol doses while preserving hemodynamic stability.
Summary
The success of AC is based on the appropriate patient selection, detailed preoperative evaluation, adequate preparation, and prevention, timely detection, and efficient management of the intraoperative complications.
... The notable progress obtained by the use of awake craniotomy in the removal of glial brain tumors has stimulated the use of this approach in other areas. For instance, among the articles published during the last year, we found case reports or small series of awake craniotomy in multiple particular clinical situations: clipping of cerebral aneurisms [10], vestibular schwannomas removal [11,12], resection of tumors in conjunction with optic radiation [13], in a patient with congenital heart disease [14], in an 8-year-old child [15], in a pregnant patient [16], and even in a deaf patient who communicated in sign language [17]. ...
Purpose of review:
The current review reports on current trends in the anesthetic management of awake craniotomy, including preoperative preparation, sedation schemes, pain management, and prevention of intraoperative complications.
Recent findings:
Both approaches for anesthesia for awake craniotomy, asleep-awake-asleep and monitored anesthesia care (MAC), have shown equal efficacy for performing intraoperative brain mapping. Choice of the appropriate scheme is currently based mainly on the preferences of the particular anesthesiologist. Dexmedetomidine has demonstrated high efficacy and safety in MAC for awake craniotomy and has become a rational alternative to propofol. Despite the high efficacy of scalp block and opioids, pain remains a common compliant in awake craniotomy. Appropriate surgical tactics can reduce pain and even prevent postoperative neurological complications. Although the efficacy of prophylaxis of intraoperative seizures with anticonvulsants remains doubtful, levetiracetam can be superior to other drugs for this purpose.
Summary:
Following a great deal of progress in anesthetic management, awake craniotomy, which had been a relatively rare approach, is now a commonly performed procedure for neurosurgical intervention. Modern anesthesia techniques can provide for successful brain mapping in almost any patient. Management of awake craniotomy in high-risk patients is a central task for future research.
... Dear Editor, With great interest I read the article of Shinoura et al. [4], reporting on their experience in the attempt to preserve hearing in microsurgery for vestibular schwannoma using awake craniotomy. The authors reported hearing preservation and useful facial nerve function in all of the patients in whom they have used intraoperative testing of the hearing level and facial nerve function. ...
... When the facial nerve was identified, its functionality was tested by electrical stimulation [2]. The authors Shinoura et al. do not mention that the study is the first report on awake craniotomy for vestibular schwannoma surgery [4]. A reference to previous experiences with awake surgery in the history of neurosurgery, however, would have been appropriate. ...
... Это совсем свежая публикация в Acta Neurochirurgica японских нейрохирургов, в которой анализируются результаты удаления неврином слухового нерва в условиях местной анестезии [87]. В серии всего 8 наблюдений и радикальность удаления существенно ниже, но функциональные результаты оказались лучше, даже в виде сохранения слуха. ...
We present an analytical review of various neurosurgical interventions in conscious patients. An analysis of the literature indicates growing interest in this problem. Craniotomy in conscious patients has been extensively used in resection of space-occupying cerebral lesions in the eloquent hemispheric areas and in epilepsy surgery. In recent years, there have been a number of reports on interventions in conscious patients with other neurosurgical pathologies, which may be regarded as a new emerging tendency in neurosurgery and neuroanesthesiology. Neurosurgery in conscious patients provides a special advantage because it enables highly functional neuromonitoring without use of complex devices.
... In the present issue of Acta Neurochirurgica, Shinoura and colleagues [9] report, as a first, awake craniotomy for a series of eight patients operated on for vestibular schwannoma. They managed to save some hearing in all, and even improved it in one patient. ...
The first awake craniotomy (AC) applications were found in archaeological excavations in Peru. The successful healing rate was 55% of trephinations in 214 skulls. Coca leaves were used as a local anesthetic before the general anesthesia (GA) era. The first recorded case of AC was the epilepsy surgery performed by Sir Victor Horsley in 1886 [1]. He resected an epileptogenic lesion from a 22-year-old man. Wilder Penfield popularized the procedure in the first half of the twentieth century [2]. Compared with GA, AC has the following advantages after tumor resection: improved outcome; greater extent of tumor resection; fewer late neurological deficits, and shorter hospital stay [3–5].
Background
Preservation of cranial nerve function in patients with benign tumors such as meningiomas and vestibular schwannomas remains difficult following microsurgery.
Methods
In this study, awake surgery was performed in 22 consecutive patients with meningiomas or vestibular schwannomas that compressed cranial nerves (I–XII). Improved, unchanged, or deteriorated cranial nerve function after surgery was evaluated.
Results
The function of 44 cranial nerves in 22 consecutive patients who underwent awake surgery for meningiomas or vestibular schwannomas improved, was unchanged, or deteriorated in eight, 35, and one nerves, respectively. Regarding the function of the olfactory (Ist) nerve, which is difficult to preserve, hyposmia improved after surgery in two patients with olfactory groove meningiomas. Regarding the auditory (VIIIth) nerve, which is also difficult to preserve, the function was improved, unchanged, or deteriorated after surgery in two, 11, and one patients, respectively, with cerebello-pontine angle meningiomas or vestibular schwannomas. In all patients with serviceable auditory function before surgery, function was preserved after surgery. In the same patients, the function of the facial (VIIth) nerve was also preserved after surgery in all patients.
Conclusions
These results suggest that awake surgery for benign brain tumors such as meningiomas and vestibular schwannomas is associated with low patient morbidity regarding cranial nerve function.
