Nodular enhancement within the internal auditory canal following retrosigmoid vestibular schwannoma resection: a unique radiological pattern

2011 ◽  
Vol 115 (4) ◽  
pp. 835-841 ◽  
Author(s):  
Matthew L. Carlson ◽  
Kathryn M. Van Abel ◽  
William R. Schmitt ◽  
Colin L. W. Driscoll ◽  
Brian A. Neff ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
High Rate ◽  
Preoperative Imaging ◽  
Incomplete Resection ◽  
Tumor Margin ◽  
Tertiary Referral Center ◽  
Original Tumor

Object The authors describe the unique occurrence of nodular enhancement within the fundus of the internal auditory canal (IAC) lateral to the preoperative radiological tumor margin following gross-total vestibular schwannoma (VS) resection. Methods The nature of the study was a retrospective chart review of records. The authors reviewed the cases of all patients who underwent microsurgical resection of a VS between January 2000 and January 2010 at a single tertiary referral center. Patients with incomplete resection, neurofibromatosis Type 2, and those with fewer than 2 postoperative MR images available for review were excluded. Postsurgical patients with IAC enhancement located lateral to the preoperative imaging–delineated tumor margin were identified. Lesion morphology was characterized on serial MR imaging studies. Clinical follow-up and outcomes were recorded. Results Over the past decade, 350 patients underwent microsurgical VS resection. Of these, 16 patients met study criteria and were found to have postsurgical enhancement in the distal aspect of the IAC lateral to the imaging limits of the preoperative tumor margin on the first postoperative MR imaging study (37.5% women, median age 45 years). Initial MR imaging was performed at a mean of 3.1 months following surgery, and the mean radiological follow-up duration was 39.8 months (range 16.4–101.9 months). None of the 16 patients developed recurrence during the follow-up course. Conclusions In contrast to previous publications that have reported a high rate of recurrence in cases involving nodular enhancement within the original tumor bed, postoperative enhancement in the IAC lateral to the original tumor margin appears to carry much less risk for tumor recurrence. These findings may be helpful when counseling patients on the recommended frequency of postoperative follow-up imaging.

Clinicopathological factors related to regrowth of vestibular schwannoma after incomplete resection

2011 ◽  
Vol 114 (5) ◽  
pp. 1224-1231 ◽  
Author(s):  
Masafumi Fukuda ◽  
Makoto Oishi ◽  
Tetsuya Hiraishi ◽  
Manabu Natsumeda ◽  
Yukihiko Fujii
Keyword(s):  
Mr Imaging ◽  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Residual Tumor ◽  
Incomplete Resection ◽  
Clinicopathological Factors ◽  
The Mean ◽  
Tumor Regrowth ◽  
Mib 1

Object The authors retrospectively analyzed various clinicopathological factors to determine which are related to regrowth during a long-term follow-up period in patients who underwent incomplete vestibular schwannoma (VS) resection. Methods This study involved 74 patients (25 men and 49 women) in whom a VS was treated surgically via the lateral suboccipital approach, and who had postoperative follow-up periods exceeding 5 years. The mean follow-up was 104.1 months (range 60–241 months), and the mean patient age at surgery was 48.1 years (range 19–75 years). The tumors ranged in size from 0 mm (localized within the internal auditory canal) to 56 mm (28.3 ± 12.2 mm [mean ± SD]). Results Gross-total resection (GTR) was performed in 41 (55%) of the 74 patients; subtotal resection ([STR]; 90–99%) in 25 (34%); and partial resection ([PR]; < 90%) in 8 (11%). Regrowth rates in the GTR, STR, and PR groups were 2.4% (1 of 41 cases), 52% (13 of 25), and 62.5% (5 of 8), respectively, and the times to regrowth ranged from 6 to 76 months (median 31.9 months). The regrowth-free survival curves differed significantly between the complete (GTR) and incomplete (STR and PR) resection groups. Eighteen (54.5%) of the 33 patients who underwent incomplete resection showed evidence of regrowth during follow-up. Univariate and multivariate analyses of various factors revealed that both the thickness of the residual tumor, based on MR imaging after surgery, and the MIB-1 index were positively related to residual tumor regrowth. The receiver operating characteristic curves, plotted for both the thickness of the residual tumor and the MIB-1 index, identified the optimal cutoff points for these values as 7.4 mm (sensitivity 83.3%, specificity 86.7%) and 1.6 (sensitivity 83.3%, specificity 66.7%), respectively. Conclusions Greater residual tumor thickness, based on MR imaging after the initial surgery, and a higher MIB-1 index are both important factors related to postoperative tumor regrowth in patients who have undergone incomplete VS resection. These patients require frequent neuroimaging investigation during follow-up to assure early detection of tumor regrowth.

Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 87-97 ◽  
Author(s):  
Wen-Yuh Chung ◽  
Kang-Du Liu ◽  
Cheng-Ying Shiau ◽  
Hsiu-Mei Wu ◽  
Ling-Wei Wang ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Gamma Knife ◽  
Vestibular Schwannoma ◽  
Tumor Volume ◽  
Radiation Effect ◽  
Gamma Knife Surgery ◽  
Homogeneous Distribution ◽  
Content Type ◽  
Fine Print

Object. The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation. Methods. A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3 (range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months. A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor. Conclusions. Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.

Headache after Removal of Vestibular Schwannoma Via the Retrosigmoid Approach: A Long-Term Follow-Up-Study

2003 ◽  
Vol 128 (3) ◽  
pp. 387-395 ◽  
Author(s):  
Bernhard Schaller ◽  
Ariane Baumann
Keyword(s):  
Fibrin Glue ◽  
Aseptic Meningitis ◽  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Retrosigmoid Approach ◽  
Bone Flap ◽  
Posterior Aspect ◽  
Dural Closure ◽  
Postoperative Headache

OBJECTIVE: Our goal was to study the occurrence and source of origin of postcraniotomy headache syndrome after removal of vestibular schwannoma via the retrosigmoid approach. METHODS: A retrospective chart analysis was conducted of all patients with headache at 3 months after removal of vestibular schwannoma from January 1981 through March 1997 and with a minimum of 24 months of follow-up. Diagnosis was made according to the headache classification and was graded using the HARNER scale. Recovery outcome was compared in selected groups of patients with and without headache. A descriptive statistical analysis was used to analyze differences between groups. RESULTS: Of the patients who underwent retrosigmoid craniotomy for removal of vestibular schwannomas, 52 of 155 patients (34%) reported having severe headache of requiring medication every day and/or feeling incapacitated 3 months after surgery. Headache was more prevalent in those who had the bone flap replaced (94% versus 27%), if there was duraplastic or direct dura closure (0% versus 100%). Laboratory-proven aseptic meningitis, most likely due to the use of fibrin glue and drilling of posterior aspect of the internal auditory canal, was mainly associated with postoperative headache (81% versus 2%). In 75% of these cases, calcifications along the brainstem had been noted. CONCLUSION: The origin of postoperative headaches after retrosigmoid vestibular schwannoma resections is not yet fully understood. Different factors may play a role in preventing or reducing headache: dural adhesions to nuchal muscles or to subcutaneous tissues and dural tension in the case of direct dural closure may explain postoperative headache from dural tension. Intradural drilling and the use of fibrin glue may be the source of aseptic meningitis as the etiology of persistent postoperative headache. Prevention of postoperative headache may include the replacement of bone flap at the end of surgery, duraplastic instead of direct dural closure, and prevention of the use of fibrin glue or extensive drilling of the posterior aspect of internal auditory canal.

scholarly journals Microsurgical Treatment and Follow-Up of KOOS Grade IV Vestibular Schwannoma: Therapeutic Concept and Future Perspective

2020 ◽  
Vol 10 ◽  
Author(s):  
Sae-Yeon Won ◽  
Andreas Kilian ◽  
Daniel Dubinski ◽  
Florian Gessler ◽  
Nazife Dinc ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Vestibular Schwannoma ◽  
Tumor Resection ◽  
Residual Tumor ◽  
High Rate ◽  
Future Perspective ◽  
Nerve Function ◽  
Repeat Surgery ◽  
Therapeutic Concept

PurposeSurgery of KOOS IV vestibular schwannoma remains challenging regarding the balance of extent of tumor resection (EoR) and functional outcome. Our aim was to evaluate the outcome of surgical resection and define a cut-off value for safe resection with low risk for tumor regrowth of KOOS IV vestibular schwannoma.MethodsAll patients presenting at the authors’ institution between 2000 and 2019 with surgically treated KOOS IV vestibular schwannoma were included. Outcome measures included EoR, facial/hearing nerve function, surgical complications and progression of residual tumor during the median follow-up period of 28 months.ResultsIn 58 patients, mean tumor volume was 17.1 ± 9.2 cm3, and mean EoR of 81.6 ± 16.8% could be achieved. Fifty-one patients were available for the follow-up analysis. Growth of residual tumor was observed in 11 patients (21.6%) followed by adjuvant treatment with stereotactic radiosurgery or repeat surgery in 15 patients (29.4%). Overall serviceable hearing preservation was achieved in 38 patients (74.5%) and good facial outcome at discharge was observed in 66.7% of patients, significantly increasing to 82.4% at follow-up. Independent predictors for residual tumor growth was EoR ≤ 87% (OR11.1) with a higher EoR being associated with a very low number of residual tumor progression amounting to 7.1% at follow-up (p=0.008).ConclusionsSubtotal tumor resection is a good therapeutic concept in patients with KOOS IV vestibular schwannoma resulting in a high rate of good hearing and facial nerve function and a very low rate of subsequent tumor progression. The goal of surgery should be to achieve more than 87% of tumor resection to keep residual tumor progression low.

Gamma knife surgery for vestibular schwannoma: 10-year experience of 195 cases

2005 ◽  
Vol 102 ◽  
pp. 87-97 ◽  
Author(s):  
Wen-Yuh Chung ◽  
Kang-Du Liu ◽  
Cheng-Ying Shiau ◽  
Hsiu-Mei Wu ◽  
Ling-Wei Wang ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Gamma Knife ◽  
Vestibular Schwannoma ◽  
Tumor Volume ◽  
Radiation Effect ◽  
Gamma Knife Surgery ◽  
Homogeneous Distribution ◽  
Content Type ◽  
Fine Print

Object.The authors conducted a study to determine the optimal radiation dose for vestibular schwannoma (VS) and to examine the histopathology in cases of treatment failure for better understanding of the effects of irradiation.Methods.A retrospective study was performed of 195 patients with VS; there were 113 female and 82 male patients whose mean age was 51 years (range 11–82 years). Seventy-two patients (37%) had undergone partial or total excision of their tumor prior to gamma knife surgery (GKS). The mean tumor volume was 4.1 cm3(range 0.04–23.1 cm3). Multiisocenter dose planning placed a prescription dose of 11 to 18.2 Gy on the 50 to 94% isodose located at the tumor margin. Clinical and magnetic resonance (MR) imaging follow-up evaluations were performed every 6 months.A loss of central enhancement was demonstrated on MR imaging in 69.5% of the patients. At the latest MR imaging assessment decreased or stable tumor volume was demonstrated in 93.6% of the patients. During a median follow-up period of 31 months resection was avoided in 96.8% of cases. Uncontrolled tumor swelling was noted in five patients at 3.5, 17, 24, 33, and 62 months after GKS, respectively. Twelve of 20 patients retained serviceable hearing. Two patients experienced a temporary facial palsy. Two patients developed a new trigeminal neuralgia. There was no treatment-related death. Histopathological examination of specimens in three cases (one at 62 months after GKS) revealed a long-lasting radiation effect on vessels inside the tumor.Conclusions.Radiosurgery had a long-term radiation effect on VSs for up to 5 years. A margin 12-Gy dose with homogeneous distribution is effective in preventing tumor progression, while posing no serious threat to normal cranial nerve function.

scholarly journals Retrosigmoid Transmeatal Endoscope-Assisted Approach in Semi-Sitting Position for Resection of Vestibular Schwannoma: 2-D operative Video

2018 ◽  
Vol 79 (S 05) ◽  
pp. S385-S386
Author(s):  
Rocio Evangelista-Zamora ◽  
Stefan Lieber ◽  
Florian Ebner ◽  
Marcos Tatagiba
Keyword(s):  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Sitting Position ◽  
Speech Discrimination ◽  
Endoscopic Assistance ◽  
Set Up ◽  
One Year ◽  
The Right ◽  
Neurovascular Structures

We present a case of a mid-sized vestibular schwannoma (T3b according to the Hannover classification) that was resected through a retrosigmoid transmeatal approach in semi-sitting position under endoscopic assistance. The patient is a 52-year-old male with acute loss of functional hearing on the right side. Audiometry confirmed a loss of up to 60 dB and lost speech discrimination, there were no associated symptoms such as tinnitus or vertigo. This 2D video demonstrates positioning, OR set-up, anatomical and surgical nuances of the skull base approach and the operative technique for microdissection of the tumor from the critical neurovascular structures, especially the facial and cochlear nerves. A gross total resection was achieved and the patient discharged home after four days with unaltered function of the facial nerve (HB I). At one year follow up there was no indication of residual or recurrence.In summary, the retrosigmoid transmeatal approach is an important and powerful tool in the armamentarium for the microsurgical management of all kinds of vestibular schwannomas. Provided the necessary anesthesiological precautions and intraoperative procedures the semi-sitting position is safe and effective. If needed, the approach can be complemented by the use of an endoscope for visualization of the distal internal auditory canal.The link to the video can be found at: https://youtu.be/pPKT4_5nIn0.

scholarly journals Cystic Meningioma in the Cerebellopontine Angle Mimicking Vestibular Schwannoma: A Case Report

2020 ◽  
pp. 1-3
Author(s):  
Yuekang Zhang ◽  
Yong Deng ◽  
Zhigang Lan ◽  
Chenghong Wang ◽  
Yuekang Zhang
Keyword(s):  
Vestibular Schwannoma ◽  
Tumor Invasion ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Neurological Dysfunction ◽  
Surgical Strategies ◽  
Cystic Meningioma ◽  
Uncommon Disease ◽  
Magnetic Resonance Imaging Mri

Cystic meningioma in the cerebellopontine angle (CPA) is an extremely uncommon disease. It is often misdiagnosed as other diseases. Its clinical features, surgical strategies and prognosis are not clearly understood. We reported a case of cystic meningioma in the CPA with tumor invasion into the internal auditory canal (IAC). Based on the typical preoperative symptoms, signs, hearing tests, and enhanced magnetic resonance imaging (MRI), the 36-year-old female patient was diagnosed with vestibular schwannoma and underwent surgical resection. Postoperative pathology revealed that the tumor was meningioma. It was totally removed without any new neurological dysfunction, and no recurrence was observed in the follow-up within 24 months. Cystic meningioma in the CPA is considered to have a high pathological grade and recurrence rate. Considering this situation, total intraoperative resection, including the enhanced wall of the tumor and postoperative follow-up may be critical.

scholarly journals Tumor-Volume Changes after Radiosurgery for Vestibular Schwannoma: Implications for Follow-Up MR Imaging Protocol

2008 ◽  
Vol 29 (5) ◽  
pp. 906-910 ◽  
Author(s):  
O.W.M. Meijer ◽  
E.J. Weijmans ◽  
D.L. Knol ◽  
B.J. Slotman ◽  
F. Barkhof ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Vestibular Schwannoma ◽  
Tumor Volume ◽  
Volume Changes ◽  
Imaging Protocol

Intrinsic tumors of the insula: a prospective surgical study of 30 patients

1996 ◽  
Vol 85 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Josef Zentner ◽  
Bernhard Meyer ◽  
Armin Stangl ◽  
Johannes Schramm
Keyword(s):  
Surgical Treatment ◽  
Mr Imaging ◽  
Karnofsky Performance Scale ◽  
Low Grade ◽  
Incomplete Resection ◽  
Content Type ◽  
Transsylvian Approach ◽  
Preoperative Magnetic Resonance ◽  
Mean Time

✓ Intrinsic insular tumors are frequently excluded from surgical treatment. The authors propose a more extensive approach to these lesions based on the results of this prospective series. From September 1993 to January 1995, 30 patients (18 males and 12 females; mean age 42 years) harboring benign (15 patients) or malignant (15 patients) tumors involving the insula underwent surgical treatment. The dominant and nondominant hemispheres were both affected in 15 cases. Two groups were defined on the basis of preoperative magnetic resonance (MR) imaging: 14 lesions were restricted to the insula and the corresponding opercula; the other 16 lesions also involved other mesocortical and/or allocortical areas. Most patients displayed only mild preoperative symptoms. The median score according to the Karnofsky performance scale was 90. Microsurgical removal was achieved via a transsylvian approach in nine cases and via a frontal and/or temporal approach in 21 cases. According to early postoperative MR imaging, complete tumor removal (100%) was seen in five patients, nearly complete (> 80%) in 21, and incomplete resection (50%–80%) in four patients. There was no operative mortality; 19 patients (63%) experienced immediate postoperative morbidity, including reduced performance. After a mean follow-up review of 8.5 months two of 21 patients suffered permanent deficits, accounting for an overall operative morbidity of 10%. At the mean time of review, three patients with Grade IV tumors had died of tumor recurrence. The authors conclude that low-grade intrinsic insular tumors, as well as Grade III tumors, can be removed with favorable results in the majority of patients. Surgery to excise glioblastomas should only be considered for patients with good preoperative performance and young age.

Iatrogenic cerebellar implantation of a vestibular schwannoma

2006 ◽  
Vol 104 (3) ◽  
pp. 452-456 ◽  
Author(s):  
Todd A. Patrick ◽  
Caterina Giannini ◽  
Michael J. Ebersold ◽  
Michael J. Link
Keyword(s):  
Vestibular Schwannoma ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Cerebellar Hemisphere ◽  
Histological Evaluation ◽  
Pathological Appearance ◽  
Surgical Implantation ◽  
Iatrogenic Implantation ◽  
Routine Imaging

✓ Metastatic seeding or iatrogenic implantation of numerous types of primary central nervous system tumors, typically along cerebrospinal fluid pathways, is a frequently described albeit rare phenomenon and has never been reported in association with vestibular schwannoma (VS). The authors present a case of inadvertent surgical implantation of VS into the cerebellar hemisphere during resection of a recurrent VS in the cerebellopontine angle and internal auditory canal. A 42-year-old man presented with a 2.5-cm right VS that was removed without complication via a retrosigmoid approach. Routine imaging performed 5 years later revealed a 1.5-cm recurrence of the VS that was subsequently removed by reopening the retrosigmoid craniotomy. Five years later—10 years after initial presentation—follow-up imaging revealed a 1-cm recurrence of the VS and a separate 2.2-cm tumor in the inferior cerebellar parenchyma with surrounding edema. Both tumors were removed without complication by reopening the previous retrosigmoid craniotomy. Histological evaluation of these tumors revealed features typical of VS and similar to those of the tissue obtained from the two prior resections. Given the similarities among these tumors in pathological appearance and mitotic index, the presence of the intraparenchymal cerebellar schwannoma was probably due to intraoperative iatrogenic implantation.

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