Endoscopic transorbital approach in children: surgical technique and early results.

OBJECTIVE: In this study, the authors aimed to describe the endoscopic transorbital approach (ETOA) in children. METHODS: Six pediatric patients (2 girls and 4 boys) underwent the ETOA for paramedian skull base lesions at a single institution between September 2016 and February 2023. RESULTS: The median age at the time of surgery was 7.5 (range 4-18) years. The median follow-up period was 33 (range 9-60) months. In this series, the ETOA level of difficulty included stage 1 (n = 2, 33.3%), stage 3 (n = 3, 50%), and stage 5 (n = 1, 16.7%). The ETOA was performed for tumor resection in 4 cases; the final pathology consisted of fibrous dysplasia, pilocytic astrocytoma, metastatic neuroblastoma, and choroid plexus papilloma. The procedure was also performed for repair of a petrous apex meningocele and for lateral orbital wall decompression of traumatic lateral rectus muscle entrapment. One patient experienced a transient cranial nerve III palsy after the procedure. There were no operative deaths in this series. CONCLUSIONS: In select cases, the ETOA can be considered a minimally invasive alternative for conventional skull base approaches in the armamentarium of pediatric skull base surgery. Further investigation and the accumulation of experience are warranted in the future to enhance the efficacy and applicability of the ETOA in pediatric patients.

Clinical Role of Microembolic Signals in Adult Moyamoya Disease With Ischemic Stroke.

Background and Purpose- Hemodynamic compromise has been implicated in moyamoya disease (MMD) with transient ischemic attacks or ischemic stroke. However, increasing evidence supports the notion that artery-to-artery embolism may also contribute to ischemic events based on microembolic signal (MES) monitoring. Methods- A total of 48 patients aged between 20 and 60 years with newly diagnosed MMD were enrolled and angiographically classified according to the Suzuki staging system. For detection of MESs, transcranial Doppler was performed at the middle cerebral artery bilaterally for a 30-minute period. Mean flow velocities in the middle cerebral artery were also evaluated and categorized into low (<40 cm/s), normal (40-80 cm/s), and high (>80 cm/s). Clinical characteristics, cerebral angiography findings, recent ischemic events within 3 months, and antiplatelet medication were correlated with transcranial Doppler findings. Results- MESs were detected in 11 of the 48 patients (23%), with a frequency of 11 of 89 (12%) examined hemispheres. The mean number of MESs was 2 (range, 1-6). Six of the 11 hemispheres (55%) presented with ischemic strokes or transient ischemic attacks, and 2 (18%) presented with hemorrhagic strokes. The presence of MESs was associated with recent ischemic events ( P=0.024) and high mean flow velocities ( P=0.016), which was usually observed in Suzuki stage I and II (early-stage MMD). After controlling for age, sex, and antiplatelet medication, both recent ischemic events (odds ratio, 6.294; 95% CI, 1.345-29.457; P=0.019) and high mean flow velocities (odds ratio, 6.172; 95% CI, 1.235-31.25; P=0.027) were found to be independent predictors of MESs. Conclusions- MESs were observed in patients with high mean flow velocities, particularly early-stage MMD, and clinically associated with recent ischemic events. A randomized controlled study is necessary to determine the efficacy of antiplatelet agents in the treatment of MES-positive MMD.

Outcome of three-fraction gamma knife radiosurgery for brain metastases according to fractionation scheme: preliminary results.

PURPOSE: The optimal interfraction intervals for fractionated radiosurgery has yet to be established. We investigated the outcome of fractionated gamma knife radiosurgery (FGKRS) for large brain metastases (BMs) according to different interfraction intervals. METHODS: Between September 2016 and May 2018, a total of 45 patients who underwent FGKRS for BMs were enrolled in this study. They were divided into two groups (standard fractionation over 3 consecutive days with a 24-h interfraction interval versus prolonged fractionation over 4 or 5 days with an interfraction interval of at least 48-h). BMs with ≥ 2 cm in maximum diameter or ≥ 5 cm3 in volume were included in analysis. RESULTS: Among 52 BMs treated with 3-fraction GKRS, 25 (48.1%) were treated with standard fractionation scheme, and 27 (51.9%) with prolonged fractionation scheme. The median follow-up period was 10.5 months (range 5-25). Local tumor control rates of the standard group were 88.9% at 6 months and 77.8% at 12 months, whereas those of the prolonged group were 100% at 6 and 12 months (p = 0.023, log-rank test). In multivariate analysis, fractionation scheme (hazard ratio [HR] 0.294, 95% CI 0.099-0.873; p = 0.027) and tumor volume (HR 0.200, 95% CI 0.051-0.781; p = 0.021) were revealed as the only significant factors affecting the local tumor control after 3-fraction GKRS. CONCLUSIONS: Our preliminary tumor control results suggest a promising role of 3-fraction GKRS with an interfraction interval of at least 48-h. This fractionation regimen could be an effective and safe treatment option in the management of large BMs.

Endoscopic transorbital approach for resection of mediobasal temporal lesions using an optic radiation-sparing strategy.

OBJECTIVE: The endoscopic transorbital approach (ETOA) has emerged as a promising minimally invasive technique for resection of lesions in the mediobasal temporal region (MTR) due to its potential to preserve the integrity of the optic radiation (OR). This study evaluated the safety and efficacy of ETOA using an OR-sparing surgical strategy for mediobasal temporal lesions. METHODS: A retrospective review was conducted of the medical records of 15 patients (7 females and 8 males) who underwent ETOA for lesions in the MTR between November 2017 and November 2022. Preoperative diffusion tensor imaging (DTI) tractography of the OR was utilized in all cases for surgical planning to visualize the spatial relations between the OR and the target mediobasal temporal lesion. RESULTS: The median age of the treated patients was 43 years (range 22-76 years), with a median follow-up duration of 12 months (range 6-35 months). Eleven lesions (73.3%) involved only the anterior segment of the MTR, while 4 lesions (26.7%) affected both the anterior and middle segments. Gross-total resection was achieved in 13 patients (86.7%) and subtotal resection in 2 (13.3%). The final pathologies included low-grade glioma (n = 5), cavernous malformation (n = 3), glioblastoma multiforme (n = 2), multinodular and vacuolating neuronal tumor (n = 1), pleomorphic xanthoastrocytoma (n = 1), anaplastic oligodendroglioma (n = 1), adenoid cystic carcinoma (n = 1), and metastatic renal cell carcinoma (n = 1). Postoperative neuro-ophthalmological examinations revealed that all patients maintained their previous visual function. Follow-up DTI tractography further confirmed the preservation of the preoperative ORs in the treated patients. No postoperative CSF leaks, infections, or cosmetic problems occurred in this series. CONCLUSIONS: The combined use of ETOA and OR tractography appears to be a feasible approach for resecting lesions involving the MTR, especially in the anterior segment. In the authors' experience, this surgical strategy enables maximal safe resection while minimizing the risk of postoperative visual dysfunction. Further studies with larger sample sizes are warranted to validate these findings and assess long-term outcomes.

Intraoperative Monitoring of the Facial Nerve during Microvascular Decompression for Hemifacial Spasm.

This review article discusses the clinical significance of intraoperative neurophysiological monitoring (IONM), provides recommendations for monitoring protocols, and considers the interpretation of results in microvascular decompression (MVD) for hemifacial spasm (HFS). The lateral spread response (LSR) is an important monitoring parameter during MVD. It helps to identify the responsible blood vessel and confirms its thorough decompression from the facial nerve. The disappearance of the LSR during surgery is associated with favorable clinical outcomes. Standard and revised monitoring protocols and the confirmation of LSR persistence and disappearance are also discussed. The blink reflex and other facial nerve monitoring modalities, such as free-running electromyography, facial motor evoked potentials, F-waves, and the Z-L response, are further considered.

Management of Cerebrospinal Fluid Leakage after Microvascular Decompression Surgery: Clinical Strategy.

(1) Background: Cerebrospinal fluid (CSF) leakage is one of the most common complications of microvascular decompression (MVD) surgery. Before fatal complications, such as intracranial infection, occur, early recognition and prompt treatment are essential. (2) Methods: The clinical data of 475 patients who underwent MVD surgery from September 2020 to March 2023 were retrospectively analyzed. In these patients, if there were any symptoms of CSF leakage, and if CSF leakage was evident, a lumbar drainage catheter was inserted immediately. (3) Results: CSF leakage was suspected in 18 (3.8%) patients. Five of these patients (1.1%) showed signs of CSF leakage during conservative management and subsequently underwent catheter insertion for lumbar drainage. The lumbar drain was removed after an average of 5.2 days, resulting in an average hospitalization of 14.8 days. In all 5 patients, CSF leakage was resolved without reoperation. (4) Conclusions: Our treatment strategy prevented the development of fatal complications. Close observation of the symptoms and postoperative temporal bone computed tomography and audiometry are considered to be good evaluation methods for all patients. If CSF leakage is certain, it is important to perform lumbar drainage immediately.

Outcomes after Microvascular Decompression for Hemifacial Spasm without Definite Radiological Neurovascular Compression at the Root Exit Zone.

The purpose of this study was to investigate the outcome of microvascular decompression (MVD) in patients with hemifacial spasm (HFS) who have no definite radiological neurovascular compression (NVC). Sixteen HFS patients without radiological NVC on preoperative MRI underwent MVD surgery. The symptoms were left-sided in fourteen (87.5%) and right-sided in two patients (12.5%). Intraoperatively, the most common vessel compressing the facial nerve was the AICA (8, 44.4%), followed by arterioles (5, 27.8%), veins (4, 22.2%), and the PICA (1, 5.6%). The most common compression site was the cisternal portion (13, 76.5%) of the facial nerve, followed by the REZ (4, 23.5%). One patient (6.3%) was found to have multiple NVC sites. Arachnoid type (7, 50%) was the most common compressive pattern, followed by perforator type (4, 28.6%), sandwich type (2, 14.3%), and loop type (1, 7.1%). A pure venous compression was seen in two patients, while a combined venous-arterial "sandwich" compression was detected in two patients. Symptom improvement was observed in all of the patients. Only one patient experienced recurrence after improvement. Based on our experience, MVD surgery can be effective for primary HFS patients with no definite radiological NVC. MVD can be considered if the patient shows typical HFS features, although NVC is not evident on MRI.

Clinicoradiological and histopathological characteristics and treatment outcomes of cerebral astroblastoma in children: a single-institution experience.

OBJECTIVE: Astroblastoma (AB) is a rare glial tumor. The optimal treatment and prognosis of this tumor remain unclear. The authors retrospectively analyzed the clinical characteristics, neuroimaging findings, histopathological results, and treatment outcomes of 7 patients with AB. METHODS: The study comprised 7 patients with pathologically proven AB who were surgically treated at Samsung Medical Center from November 1994 to January 2019. Clinicoradiological, histopathological, and surgical records were reviewed. RESULTS: The patients included 5 girls (71.4%) and 2 boys (28.6%), with a median age of 13 years. All patients showed contrast enhancement on preoperative MRI: 5 ABs (71.4%) showed a concomitant solid and cystic appearance, and 2 (28.6%) demonstrated a solid appearance. ABs in 6 patients (85.7%) showed a well-circumscribed, characteristic "bubbly" appearance on T2-weighted MRI. Gross-total resection (GTR) was achieved in all cases (100%). Six patients (85.7%) were diagnosed with high-grade AB and 1 (14.3%) with low-grade AB. Six (85.7%) of the 7 patients received adjuvant treatment after resection, including 5 (83.3%) with AB who received chemotherapy and radiotherapy and 1 (16.7%) who received proton therapy alone. The median clinical follow-up duration was 96 months (range 48-189 months). Two patients experienced recurrence, and all patients in this series were alive at the last follow-up. CONCLUSIONS: In this study, the clinicoradiological and histopathological features of AB were described. Based on the authors' limited experience with 7 cases, resection with the goal of GTR is currently the mainstream treatment for AB, and adjuvant radiation treatment should be considered after surgery.

Outcome of endoscopic transcortical intraventricular biopsy of isolated thickened pituitary stalk lesions in children.

OBJECTIVE: The purpose of this study was to investigate the efficacy and safety of endoscopic transcortical intraventricular biopsy in pediatric patients with isolated thickened pituitary stalk lesions. METHODS: From 1994 to 2018, 16 pediatric patients (8 males and 8 females) underwent endoscopic transcortical intraventricular biopsy at a single institution to establish an accurate pathological diagnosis for appropriate treatment strategies. RESULTS: Preoperatively, the median diameter of the pituitary stalks was 5.31 ± 1.67 mm (range 3.86-9.17 mm). Overall, the diagnostic yield at endoscopic intraventricular biopsy was 93.8%. Histopathological diagnosis included germinoma (n = 10, 62.5%), Langerhans cell histiocytosis (n = 4, 25%), pilocytic astrocytoma (n = 1, 6.3%), and pituicytoma (n = 1, 6.3%). Two patients developed new diabetes insipidus after the procedure, and 3 patients had new postoperative hypothyroidism. There were no postoperative neurological deficits in this series. CONCLUSIONS: Neuroendoscopic biopsy via the transcortical intraventricular corridor was shown to be safe and to aid in a reliable histopathological diagnosis in the management of isolated pituitary stalk lesions in pediatric patients. It can be considered a minimally invasive alternative to open biopsy via transcranial or endonasal corridors.

Prognostic Value of Lateral Spread Response Recorded 1 Month After Microvascular Decompression for the Treatment of Hemifacial Spasm.

BACKGROUND: The predictive value of intraoperative disappearance of the lateral spread response (LSR) during microvascular decompression surgery for hemifacial spasm treatment is unclear. Studies evaluating the clinical implications of the LSR recorded during the postoperative period are also limited. OBJECTIVE: To analyze the LSR 1 month postoperatively and to evaluate its prognostic value until 1 year postsurgery. METHODS: In total, 883 patients who underwent microvascular decompression between 2016 and 2018 were included. LSR was recorded preoperatively, intraoperatively before decompression, intraoperatively after decompression, and 1 month postoperatively. The outcomes were evaluated at 1 week, 1 month, and 1 year postoperatively. RESULTS: The presence of preoperative and intraoperative LSR after decompression did not predict the postoperative outcome at 1 year. In 246 patients (27.9%), the postoperative LSR at 1 month was not identical to that recorded intraoperatively after decompression. Postoperative LSR at 1 month was associated with a worse outcome at 1 month (P < .0001) and 1 year (P = .0002) postoperatively. Patients with residual symptoms and a LSR 1 month postoperatively were more likely to show residual symptoms 1 year postoperatively, with a positive predictive value of 50.7%. CONCLUSION: Unlike the intraoperative LSR, the LSR at 1 month postoperatively showed prognostic value in predicting 1-year postoperative outcomes and was useful for identifying patients with a high risk of unfavorable outcomes. Thus, confirming the presence of postoperative LSR is necessary.

Treatment Strategy for Giant Solid Hemangioblastomas in the Posterior Fossa: A Retrospective Review of 13 Consecutive Cases.

OBJECTIVE: To analyze radiologic characteristics, treatment strategy, and treatment outcomes of posterior fossa giant solid hemangioblastomas (GSHBs; ≥4 cm in maximum diameter). METHODS: We performed a retrospective study of 13 consecutive patients (9 male and 4 female patients; mean age, 57.5 ± 13.3 years; range, 24-76 years) with GSHB who underwent surgical resection at a single institution between 2002 and 2018. The median follow-up was 33 months (range, 12-120 months). For each patient, neuroimaging findings, operative record, and treatment outcome were reviewed. RESULTS: Seven tumors (53.8%) were located within cerebellar hemispheres, 4 (30.8%) in proximity to the brainstem, 1 (7.7%) within the cerebellar vermis, and 1 (7.7%) in the cerebellopontine angle. The mean maximum diameter was 4.8 ± 0.8 cm (range, 4.0-6.7 cm). Gross total resection was achieved in 11 patients (84.6%), and near-total resection in 2 patients (15.4%). Surgical complications occurred in 5 patients (38.5%); persistent neurologic deficits occurred in 2 patients (15.4%). Estimated progression-free survival after surgery was 92.3%, 80.8%, and 80.8% at 1, 5, and 10 years, respectively, whereas the estimated 1-year, 5-year, and 10-year overall survival was 100%, 90%, and 90%, respectively. CONCLUSIONS: GSHBs are surgically challenging. The current study shows that favorable outcome can be achieved for GSHBs in the cerebellar hemispheres and vermis. For those involving the brainstem, planned near-total resection or subtotal resection in a piecemeal fashion can be attempted if en bloc resection is judged to be infeasible, and further intervention can be considered as needed.

Use of endoscopic transorbital and endonasal approaches for 360° circumferential access to orbital tumors.

OBJECTIVE: Orbital tumors are often surgically challenging because they require an extensive fronto-temporo-orbital zygomatic approach (FTOZ) and a multidisciplinary team approach to provide the best outcomes. Recently, minimally invasive endoscopic techniques via a transorbital superior eyelid approach (ETOA) or endoscopic endonasal approach (EEA) have been proposed as viable alternatives to transcranial approaches for orbital tumors. In this study, the authors investigated the feasibility of 360° circumferential access to orbital tumors via both ETOA and EEA. METHODS: Between April 2014 and June 2019, 16 patients with orbital tumors underwent either ETOA or EEA at the authors' institution. Based on the neuro-topographic "four-zone model" of the orbit with its tumor epicenter around the optic nerve in the coronal plane, ETOA (n = 10, 62.5%) was performed for tumors located predominantly superolateral to the nerve and EEA (n = 6, 37.5%) for those located predominantly inferomedial to the nerve. Eight patients (50%) presented with intraconal tumors and 8 (50%) with extraconal ones. The orbital tumors included orbital schwannoma (n = 6), cavernous hemangioma (n = 2), olfactory groove meningioma (n = 1), sphenoorbital meningioma (n = 1), chondrosarcoma (n = 1), trigeminal schwannoma (n = 1), metastatic osteosarcoma (n = 1), mature cystic teratoma (n = 1), sebaceous carcinoma (n = 1), and ethmoid sinus osteoma (n = 1). The clinical outcomes and details of surgical techniques were reviewed. RESULTS: Gross-total resection was achieved in 12 patients (75%), near-total resection in 3 (18.8%), and subtotal resection in 1 (6.2%). Eight (88.9%) of the 9 patients with preoperative proptosis showed improvement after surgery, and 4 (66.7%) of the 6 patients with visual symptoms demonstrated improvement. Four (40%) of the 10 patients treated with ETOA experienced partial third nerve palsy immediately after surgery (3 transient and 1 persistent). There have been no postoperative CSF leaks or infections in this series. CONCLUSIONS: Without transcranial approaches requiring temporalis muscle dissection and orbitozygomatic osteotomy, the selection of ETOA or EEA based on a concept of a four-zone model with its epicenter around the optic nerve successfully provides a minimally invasive 360° circumferential access to the entire orbit with acceptable morbidity.

Clinical Significance of Tumor-Related Edema of Optic Tract Affecting Visual Function in Patients with Sellar and Suprasellar Tumors.

OBJECTIVE: Preoperative tumor-related edema of the optic tract (EOT) is often found along the white matter tract of the visual system. However, the relationship of EOT with visual function and outcome remains unclear. Therefore we aimed to elucidate whether the presence of EOT is associated with visual outcome in patients with sellar and suprasellar tumors. METHODS: A total of 212 eyes of 106 patients who underwent endoscopic endonasal surgery for sellar and suprasellar tumors at our institution between March 2016 and August 2018 were included in this retrospective study. Data on patient characteristics, preoperative magnetic resonance imaging findings, and ophthalmologic evaluations were collected. Patients were assigned to 2 groups depending on preoperative magnetic resonance imaging findings (EOT group = 19 [17.9%], non-EOT group = 87 [82.1%]). Visual acuity, visual field (VF), global visual function score, VF index, VF mean deviation, and retinal nerve fiber layer thickness as determined by optical coherence tomography were compared between the groups before and after treatment. RESULTS: In the EOT group, 4 patients had pituitary adenoma, 8 had craniopharyngioma, and 7 had other pathologies. There was no significant difference of pathologies between the groups. Preoperatively, EOT group showed significantly lower values of global visual function score, VF index, mean deviation, and retinal nerve fiber layer thickness than did the non-EOT group (P < 0.001). Postoperatively, the EOT group showed worse visual outcomes than did the non-EOT group. CONCLUSIONS: This study reveals that EOT caused by sellar and suprasellar tumors is associated with worse visual function and poor improvement postoperatively.

Clinical Efficacy of Optical Coherence Tomography to Predict the Visual Outcome After Endoscopic Endonasal Surgery for Suprasellar Tumors.

BACKGROUND: Prediction of visual outcome after endoscopic endonasal tumor resection still remains a challenge. We investigated the prognostic value of the preoperative peripapillary retinal nerve fiber layer (pRNFL) using optical coherence tomography for visual outcome after endoscopic endonasal surgery (EES) for suprasellar tumors. METHODS: We retrospectively analyzed 122 patients who underwent EES for sellar and suprasellar tumors between January 2016 and January 2018. We retrospectively analyzed the pre- and postoperative relationship between pRNFL thickness and visual outcome based on visual acuity (visual acuity score) and visual field (mean deviation [MD]). RESULTS: Preoperatively, 216 eyes (mean global pRNFL thickness, 94.3 ± 12.4 µm; 88.5%) were included in the normal pRNFL group (≥70 µm) and 28 eyes (mean global pRNFL thickness, 54.3 ± 11.0 µm; 11.5%) were included in the thin pRNFL group (<70 µm). There was a very strong correlation between pre- and postoperative pRNFL thickness (r = 0.930). The thin pRNFL group showed a stronger correlation between pre- and postoperative MDs than the normal pRNFL group (r = 0.619 and r = 0.420, respectively; P < 0.01). Multivariate analyses identified pRNFL thickness as the only significant predictor of postoperative visual acuity (odds ratio [OR], 25.02; 95% confidence interval [CI], 7.68-81.50; P < 0.01) and visual field (OR, 39.46; 95% CI, 10.39-149.83; P < 0.01). CONCLUSIONS: Preoperative pRNFL thickness plays a prognostic value in postoperative visual outcome after EES for sellar and suprasellar tumors. Patients with pRNFL thickness ≥70 µm before surgery are more likely to improve visual outcome than those with thickness <70 µm.

Endoscopic transorbital surgery for Meckel's cave and middle cranial fossa tumors: surgical technique and early results.

OBJECTIVETumors involving Meckel's cave remain extremely challenging because of the surrounding complex neurovascular structures and deep-seated location. The authors investigated a new minimal-access technique using the endoscopic transorbital approach (eTOA) through the superior eyelid crease to Meckel's cave and middle cranial fossa lesions and reviewed the most useful surgical procedures and pitfalls of this approach.METHODSBetween September 2016 and January 2018, the authors performed eTOA in 9 patients with tumors involving Meckel's cave and the middle cranial fossa. The lesions included trigeminal schwannoma in 4 patients, meningioma in 2 patients, metastatic brain tumor in 1 patient, chondrosarcoma in 1 patient, and dermoid cyst in 1 patient. In 7 of the 9 patients, eTOA alone was performed, while the other 2 patients underwent a combined eTOA and endoscopic endonasal approach or retrosigmoid craniotomy. Data including details of surgical techniques and clinical outcomes were recorded.RESULTSGross-total resection was performed in 7 of the 9 patients (77.8%). Four patients underwent extended eTOA (with lateral orbital rim osteotomy). Drilling of the trapezoid sphenoid floor, a middle fossa "peeling" technique, and full visualization of Meckel's cave were applied to approach the lesions. Tumors were exposed and removed extradurally in 3 patients and intradurally in 6 patients. There was no postoperative CSF leak.CONCLUSIONSThe eTOA affords a direct route to access Meckel's cave and middle cranial fossa lesions. With experience, this novel approach can be successfully applied to selected skull base lesions. To achieve successful removal of the tumor, emphasis should be placed on the importance of adequately removing the greater sphenoid wing and vertical crest. However, because of limited working space eTOA may not be an ideal approach for posterior fossa lesions.

Clinical outcomes of an endoscopic transclival and transpetrosal approach for primary skull base malignancies involving the clivus.

OBJECTIVE The endoscopic endonasal approach for treating primary skull base malignancies involving the clivus is a formidable task. The authors hypothesized that tumor involvement of nearby critical anatomical structures creates hurdles to endoscopic gross-total resection (GTR). The aim of this study was to retrospectively review the clinical outcomes of patients who underwent an endoscopic endonasal approach to treat primary malignancies involving the clivus and to analyze prognostic factors for GTR. METHODS Between January 2009 and November 2015, 42 patients underwent the endoscopic endonasal approach for resection of primary skull base malignancies involving the clivus at 2 independent institutions. Clinical data; tumor locations within the clivus; and anatomical involvement of the cavernous or paraclival internal carotid artery, cisternal trigeminal nerve, hypoglossal canal, and dura mater were investigated to assess the extent of resection. Possible prognostic factors affecting GTR were also analyzed. RESULTS Of the 42 patients, 37 were diagnosed with chordomas and 5 were diagnosed with chondrosarcomas. The mean (± SD) preoperative tumor volume was 25.2 ± 30.5 cm3 (range 0.8-166.7 cm3). GTR was achieved in 28 patients (66.7%) and subtotal resection in 14 patients (33.3%). All tumors were classified as upper (n = 17), middle (n = 17), or lower (n = 8) clival tumors based on clival involvement, and as central (24 [57.1%]) or paramedian (18 [42.9%]) based on laterality of the tumor. Univariate analysis identified the tumor laterality (OR 6.25, 95% CI 1.51-25.86; p = 0.011) as significantly predictive of GTR. In addition, the laterality of the tumor was found to be a statistically significant predictor in multivariate analysis (OR 41.16, 95% CI 1.12-1512.65; p = 0.043). CONCLUSIONS An endoscopic endonasal approach can provide favorable clinical and surgical outcomes. However, the tumor laterality should be considered as a potential obstacle to total removal.

Reconstructive outcome of intraoperative cerebrospinal fluid leak after endoscopic endonasal surgery for tumors involving skull base.

Endoscopic transnasal surgery for tumors located at the base of the skull has a high incidence of postoperative cerebrospinal fluid (CSF) leaks. Here, we assessed the repair outcomes for high-flow CSF leaks based upon the tumor location, and analyzed the reasons for repair failure after transnasal endoscopic surgery solely for tumors involving the base of the skull. From Feb. 2009 to Dec. 2014 we performed endoscopic endonasal surgery for a variety of skull base lesions in 788 patients at our institution. Among them, 95 patients with intradural skull base tumors underwent endoscopic transnasal surgery. We performed surgical repairs with a multilayered nonvascularized construct (38 patients) and a vascularized pedicled nasoseptal flap construct combined with a fascia graft (57 patients). Overall, 14 of 95 patients (14.7%) who underwent endoscopic transnasal surgery for skull base tumors developed postoperative CSF leaks. The major causes of repair failure included graft disruption by a lack of counter-pressure in the multilayered non-vascularized technique, and inadequate drilling of the sphenoid bone, displacement of the flap due to pressure from CSF or gravity, or disruption of flap integrity in the vascularized pedicled flap technique. Logistic regression analysis revealed that there was no significant association between repair failure and age, sex, type of reconstructive method used, and primary tumor type (p>0.05). Reconstruction after endoscopic endonasal surgery remained challenging, especially for non-pituitary skull base tumors requiring intra-arachnoidal dissection. Recent advances in reconstructive techniques require the accumulation of experiences with sufficient dexterity to achieve an acceptable morbidity rate.

Clinical efficacy of radiation-sterilized allografts for sellar reconstruction after transsphenoidal surgery.

OBJECTIVE: The aim of this study was to assess the safety and efficacy of radiation-sterilized allografts of iliac bone and fascia lata from cadaver specimens to repair skull base defects after transsphenoidal surgery. METHODS: Between May 2009 and January 2010, 31 consecutive patients underwent endonasal transsphenoidal surgery and all patients received sellar reconstruction using allografts following tumor removal. The allografts were obtained from the local tissue bank and harvested from cadaver donors. The specimens used in our approach were tensor fascia lata and the flat area of iliac bone. For preparation, allografts were treated with gamma irradiation after routine screening by culture, and then stored at -70℃. RESULTS: The mean follow-up period after surgery was 12.6 months (range, 7.4-16 months). Overall, postoperative cerebrospinal fluid (CSF) leaks occurred in three patients (9.7%) and postoperative meningitis in one patient (3.2%). There was no definitive evidence of wound infection at the routine postoperative follow-up examination or during re-do surgery in three patients. Postoperative meningitis in one patient was improved with the use of antibiotics and prolonged CSF diversion. CONCLUSION: We suggest that allograft materials can be a feasible alternative to autologous tissue grafts for sellar reconstruction following transsphenoidal surgery under selected circumstances such as no or little intraoperative CSF leaks.

The therapeutic efficacy of fractionated radiotherapy and gamma-knife radiosurgery for craniopharyngiomas.

There is no consensus regarding the optimal timing of radiation treatment (RT) for residual or recurrent craniopharyngioma or the preferred treatment modality between fractionated radiotherapy (FRT) and gamma-knife radiosurgery (GKRS) in terms of morbidity and efficacy. This study aims to clarify the optimal timing of RT for residual or recurrent tumors by analyzing the outcomes of RT as a salvage or adjunctive treatment, and to compare the therapeutic efficacy of FRT and GKRS. Between April 1995 and November 2009, 50 of 129 patients received RT for recurrent or residual tumors. The patients were analyzed for medical data, endocrine outcome, long-term morbidity and mortality rates, recurrence rates, and responses to adjuvant RT and GKRS. Mean progression-free survival was 92.5 months (95% confidence interval, 70.9-114.1 months). Univariate analysis revealed that pre-irradiation tumor volume was closely related to better prognosis (p=0.01). We found that there was no significant difference in recurrence between patients treated with adjuvant compared to salvage RT (p>0.05). Although we found no difference in the efficacy of FRT and GKRS, five patients were newly diagnosed with hypopituitarism following RT. We concluded that RT has a very high rate of tumor control after both adjuvant or salvage RT. This study highlights the relative safety and efficacy of FRT and GKRS.