Increasing time to postoperative stereotactic radiation therapy for patients with resected brain metastases: investigating clinical outcomes and identifying predictors associated with time to initiation.

We sought to determine the impact of time to initiation (TTI) of post-operative radiosurgery on clinical outcomes for patients with resected brain metastases and to identify predictors associated with TTI. All patients with resected brain metastases treated with postoperative SRS or fractionated stereotactic radiation therapy (fSRT) from 2012 to 2016 at a single institution were reviewed. TTI was defined as the interval from resection to first day of radiosurgery. Receiver operating characteristic (ROC) curves were used to identify an optimal threshold for TTI with respect to local failure (LF). Survival outcomes were estimated using the Kaplan-Meier method and analyzed using the log-rank test and Cox proportional hazards models. Logistic regression models were used to identify factors associated with ROC-determined TTI covariates. A total of 79 resected lesions from 73 patients were evaluated. An ROC curve of LF and TTI identified an optimal threshold for TTI of 30.5 days, with an area under the curve of 0.637. TTI > 30 days was associated with an increased hazard of LF (HR 4.525, CI 1.239-16.527) but was not significantly associated with survival (HR 1.002, CI 0.547-1.823) or distant brain failure (DBF, HR 1.943, CI 0.989-3.816). Fifteen patients (20.5%) required post-operative inpatient rehabilitation. Post-operative rehabilitation was associated with TTI > 30 days (OR 1.48, CI 1.142-1.922). In our study of resected brain metastases, longer time to initiation of post-operative radiosurgery was associated with increased local failure. Ideally, post-op SRS should be initiated within 30 days of resection if feasible.

Endoscopic endonasal surgery for olfactory groove meningiomas: outcomes and limitations in 50 patients.

OBJECT: Recently, endoscopic endonasal surgery (EES) has been introduced in the management of skull base tumors, with constantly improving outcomes and increasing indications. The authors retrospectively reviewed the effectiveness of EES in the management of olfactory groove meningiomas. METHODS: Between February 2003 and December 2012, 50 patients (64% female) with olfactory groove meningiomas underwent EES at the University of Pittsburgh Medical Center. The authors present the results of EES and analyze the resection rates, clinical outcome, complications, and limitations of this approach. RESULTS: Forty-four patients presented with primary tumors, whereas six were previously treated elsewhere. The patients' mean age was 57.1 years (range 27-88 years). Clinical presentation included altered mental status (36%), visual loss (30%), headache (24%), and seizures (20%). The mean maximum tumor diameter was 41.6 mm (range 18-80 mm). All patients underwent EES, which was performed in stages in 18 giant tumors. Complete tumor resection (Simpson Grade I) was achieved in 66.7% of the 45 patients in whom it was the goal, and 13 (28.9%) had neartotal resection (> 95% of the tumor). Tumor size, calcification, and absence of cortical cuff from vasculature were significant factors that influenced the degree of resection (p = 0.002, p = 0.024, and p = 0.028, respectively). Tumor residual was usually at the most lateral and anterior tumor margins. Following EES, mental status was improved or normalized in 77.8% of the cases, vision was improved or restored in 86.7%, and headaches resolved in 83.3%. There was no postoperative deterioration of presenting symptoms. Complications were increased in tumors > 40 mm and included CSF leakage (30%), which was significantly associated with lobular tumor configuration (p = 0.048); pulmonary embolism/deep vein thrombosis, more commonly in elderly patients (20%); sinus infections (10%); and delayed abscess months or years after EES (6%). One patient had an intraoperative vascular injury resulting in transient hemiparesis (2%). There were no perioperative deaths. During a mean follow-up period of 32 months (median 22 months, range 1-115 months), 1 patient underwent repeat EES for tumor regrowth. CONCLUSIONS: Endoscopic endonasal surgery has shown good clinical outcomes regardless of patient age, previous treatment, or tumor characteristics. Tumor size > 40 mm, calcification, and absence of cortical vascular cuff limit GTR with EES; in addition, large tumors are associated with increased postoperative complications. Significant lateral and anterior dural involvement may represent indications for using traditional craniotomies for the management of these tumors. Postoperative CSF leakage remains a problem that necessitates innovations in EES reconstruction techniques.

Aseptic meningitis after transsphenoidal management of Rathke's cleft cyst: case report and review of the literature.

Aseptic meningitis after transsphenoidal surgery (TSS) for treatment of Rathke's cleft cyst (RCC) is a rare complication caused by the leakage of the cyst contents within the subarachnoid space. We present a case of aseptic meningitis occurring after TSS for a RCC. During surgery, the cyst wall was subtotally removed, and intraoperative cerebrospinal fluid (CSF) leakage was observed. The patient developed meningeal signs and symptoms on the first postoperative day. CSF examinations were highly suggestive of aseptic meningitis. Histological examination confirmed a granulomatous inflammatory reaction of the RCC wall. Preexisting inflammation, subtotal cyst wall resection, intraoperative erosion of the diaphragma sellae and placement of a lumbar drain may be risk factors for the development of aseptic meningitis.

Collision sellar lesions: experience with eight cases and review of the literature.

The concomitant presence of a pituitary adenoma with a second sellar lesion in patients operated upon for pituitary adenoma is an uncommon entity. Although rare, quite a great variety of lesions have been indentified coexisting with pituitary adenomas. In fact, most combinations have been described before, but an overview with information on the frequency of combined pathologies in a large series has not been published. We present a series of eight collision sellar lesions indentified among 548 transsphenoidally resected pituitary adenomas in two Neurosurgical Departments. The histological studies confirmed a case of sarcoidosis within a non-functioning pituitary adenoma, a case of intrasellar schwannoma coexisting with growth hormone (GH) secreting adenoma, two Rathke's cleft cysts combined with pituitary adenomas, three gangliocytomas associated with GH-secreting adenomas, and a case of a double pituitary adenoma. The pertinent literature is discussed with emphasis on pathogenetic theories of dual sellar lesions. Although there is no direct evidence to confirm the pathogenetic relationship of collision sellar lesions, the number of cases presented in literature makes the theory of an incidental occurrence rather doubtful. Suggested hypotheses about a common embryonic origin or a potential interaction between pituitary adenomas and the immune system are presented.

Non-adenomatous sellar lesions: experience of a single centre and review of the literature.

Non-adenomatous sellar lesions represent a diagnostic and occasionally a therapeutic challenge. The purpose of the study was to provide an overview of the clinical and radiographic characteristics of non-adenomatous sellar lesions operated at our department, with emphasis on treatment options. In our transsphenoidal surgical series of 300 cases, 29 non-adenomatous sellar lesions (9.7%) were identified by histology. Medical files and imaging findings were retrospectively analysed. Clinical presentation was usually a result of local mass effect. Imaging features were not always diagnostic. Of 29 non-adenomatous sellar lesions, total tumour excision with transsphenoidal surgery was achieved in 17, and no supplemental treatment was needed. Lesions partially resected were further treated with reoperation, radiation therapy, or medical therapy, tailored to individuals. In our experience, non-adenomatous sellar lesions represent a more prevalent clinical entity than expected. Pituitary surgeons should be aware of their existence to reconstruct treatment strategy, proceeding to adjuvant therapy when necessary.

Intra-sellar schwannoma co-existing with GH-secreting pituitary adenoma.

BACKGROUND: We present a unique example of an intra-sellar schwannoma co-existing with a growth hormone (GH)-secreting pituitary adenoma. METHOD AND FINDINGS: The patient presented with acromegaly and magnetic resonance imaging (MRI) revealed an intra-sellar mass. The tumour was totally resected via a sub-labial trans-sphenoidal approach. Histopathology demonstrated the presence of a GH-secreting adenoma as well as a schwannoma at the periphery of the adenoma. After surgical excision, remission of the acromegaly occurred. Follow-up monitoring showed no evidence of recurrence of the adenoma two years after surgery. CONCLUSION: To the best of our knowledge, this is the first example of an intra-sellar schwannoma co-existing with a GH-secreting pituitary adenoma.

Subependymomas of the lateral ventricle: tumor recurrence correlated with increased Ki-67 labeling index.

Subependymomas of the lateral ventricles are rare tumors. We present two patients with subependymomas of the lateral ventricle, who underwent gross total resection of the tumor via transcallosal approach. The patient, with increased Ki-67 labeling index had recurrence of tumor two years after the initial operation. We emphasize at the risk of recurrence which is probably correlated with Ki-67 labeling index.

The limits of transsellar/transtuberculum surgery for craniopharyngioma.

The proximity of craniopharyngiomas to vital neurovascular structures and their high recurrence rates make them one of the most challenging brain tumors to treat. Although surgery remains the first line of therapy and offers the best chance of radical resection and oncological cure, the high recurrence tendency of craniopharyngiomas, even after apparent total removal, often makes adjuvant treatment essential. The endoscopic endonasal approach (EEA) has been recently introduced as a treatment option for both pediatric and adult craniopharyngiomas, rapidly gaining wide acceptance over the traditional transcranial approaches. Although the primary role of EEA over traditional transcranial approaches has been slowly accepted in the literature, little has been written about the limitations and potential contraindications of this approach in the treatment of craniopharyngiomas. This article presents the advantages and highlights the limitations of endoscopic transsellar/transtuberculum surgery for craniopharyngiomas. In every case, surgery should be tailored to individuals based on their age and comorbidities, presenting symptoms, tumor characteristics, prior treatment and treatment tolerance, as well as the surgeon's preference based on personal experience and comfort.

Risk factors associated with postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery.

OBJECTIVE The aim in this paper was to determine risk factors for the development of a postoperative CSF leak after an endoscopic endonasal approach (EEA) for resection of skull base tumors. METHODS A retrospective review of patients who underwent EEA for the resection of intradural pathology between January 1997 and June 2012 was performed. Basic demographic data were collected, along with patient body mass index (BMI), tumor pathology, reconstruction technique, lumbar drainage, and outcomes. RESULTS Of the 615 patients studied, 103 developed a postoperative CSF leak (16.7%). Sex and perioperative lumbar drainage did not affect CSF leakage rates. Posterior fossa tumors had the highest rate of CSF leakage (32.6%), followed by anterior skull base lesions (21.0%) and sellar/suprasellar lesions (9.9%) (p < 0.0001). There was a higher leakage rate for overweight and obese patients (BMI > 25 kg/m2) than for those with a healthy-weight BMI (18.7% vs 11.5%; p = 0.04). Patients in whom a pedicled vascularized flap was used for reconstruction had a lower leakage rate than those in whom a free graft was used (13.5% vs 27.8%; p = 0.0015). In patients with a BMI > 25 kg/m2, the use of a pedicled flap reduced the rate of CSF leakage from 29.5% to 15.0% (p = 0.001); in patients of normal weight, this reduction did not reach statistical significance (21.9% [pedicled flap] vs 9.2% [free graft]; p = 0.09). CONCLUSIONS Preoperative BMI > 25 kg/m2 and tumor location in the posterior fossa were associated with higher rates of postoperative CSF leak. Use of a pedicled vascularized flap may be associated with reduced risk of a CSF leak, particularly in overweight patients.

Endoscopic Endonasal and Transcranial Surgery for Microsurgical Resection of Ventral Foramen Magnum Meningiomas: A Preliminary Experience.

BACKGROUND: Purely ventral foramen magnum meningiomas are challenging tumors to treat given their location, and proximity and relationship to vital neurovascular structures. OBJECTIVE: To present endoscopic endonasal surgery (EES) as a complementary approach to the far-lateral suboccipital approach (FLA) for ventral midline tumors. METHODS: From May 2008 to October 2013, 5 patients underwent EES and 5 FLA for primary ventral foramen magnum meningiomas. We retrospectively reviewed their records to evaluate outcomes. RESULTS: Nine of 10 patients presented with long-tract and lower cranial nerve deficits. All patients who presented with deficits preoperatively completely normalized after tumor resection regardless of approach. Gross total resection was achieved in 2 cases in the EES group and 4 cases in the FLA group (the rest were near total). Vascular encasement was a limitation to gross total resection with both approaches. Preoperative median Karnofsky Performance Scale score was 80 and improved to 100 in both groups. Following EES, 1 patient developed cerebrospinal fluid leak with resultant meningitis. Two patients developed hydrocephalus, one of which developed an epidural abscess following necrosis of the nasoseptal flap, requiring debridement. In the FLA group, 1 patient developed a pseudomeningocele associated with hydrocephalus. One patient developed an abdominal fat graft site hematoma. CONCLUSION: Both approaches provide excellent results for resection of ventral foramen magnum meningiomas, with reconstruction and hydrocephalus as the main sources of complication. In our practice, EES is a preferred technique in ventral, purely midline tumors with limited inferior extension and reduced lower cranial nerve manipulation, whereas FLA is preferred in tumors with lateral and caudal extension below the tip of the dens.

National Trends for Reoperation in Older Patients with Glioblastoma.

BACKGROUND: Despite multimodal therapies extending patient survival, glioblastoma (GBM) recurrence is all but a certainty. To date, there are few single-center studies of reoperations. Our study aimed to assess GBM reoperation trends nationally in older patients, with emphasis on outcomes. METHODS: The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was searched to identify patients 66 years and older with GBM from 1997 to 2010. The primary outcome was survival after diagnosis. Kaplan-Meier curves and multivariate analysis with proportional hazard ratios were used. RESULTS: Three thousand nine hundred sixty-three patients with recurrent GBM who initially received a surgical resection were identified (mean age = 74.7 years). Four hundred ninety-six (12%) of the patients with recurrent GBM underwent at least one reoperation at an average of 7.2 months after the initial diagnosis. Reoperation increased survival in patients compared with those who did not have surgical resection (12 vs. 5 months; P < 0.0001; hazard ratio [HR] = 0.666). Within the reoperated cohort, gross total resection improved median survival over subtotal resection (HR = 0.779). Two or more reoperations upon GBM recurrence improved survival to 17 months (P = 0.002). The overall complication rate was 21.7% in the initial resection-only group, versus 20.4% in the 1-reoperation group and 25.3% in the 2-reoperation group. CONCLUSIONS: Although definitive conclusions cannot be made given the lack of granularity, our national database study supports gross total resection as the initial treatment of choice, followed by reoperation at the time of recurrence, if tolerated, even in older patients.

Endoscopic endonasal surgery for epidermoid and dermoid cysts: a 10-year experience.

OBJECTIVEEpidermoid and dermoid cysts may be found along the cranial base and are commonly resected via open transcranial approaches. The use of endoscopic endonasal approaches for resection of these tumors has been rarely reported.METHODSThe authors retrospectively reviewed the medical records of 21 patients who underwent endoscopic endonasal surgery for epidermoid and dermoid cyst resection at the University of Pittsburgh Medical Center between January 2005 and June 2014. Surgical outcomes and variables that might affect the extent of resection and complications were analyzed.RESULTSTotal resection (total removal of cyst contents and capsule) was achieved in 8 patients (38.1%), near-total resection (total removal of cyst contents, incomplete removal of cyst capsule) in 9 patients (42.9%), and subtotal resection (incomplete removal of cyst contents and capsule) in 4 patients (19%). Larger cyst volume (≥ 3 cm3) and intradural location (15 cysts) were significantly associated with nontotal resection (p = 0.008 and 0.0005, respectively). In the whole series, surgical complications were seen in 6 patients (28.6%). No complications were observed in patients with extradural cysts. Among the 15 patients with intradural cysts, the most common surgical complication was postoperative CSF leak (5 patients, 33.3%), followed by postoperative intracranial infection (4 patients, 26.7%). Larger cysts and postoperative CSF leak were associated with intracranial infection (p = 0.012 and 0.028, respectively). Subtotal resection was marginally associated with intracranial infection when compared with total resection (p = 0.091). All patients with neurological symptoms improved postoperatively with the exception of 1 patient with unchanged abducens nerve palsy.CONCLUSIONSEndoscopic endonasal approaches may be effectively used for resection of epidermoid and dermoid cysts in carefully selected cases. These approaches are recommended for cases in which a total or near-total resection is possible in addition to a multilayer cranial base reconstruction with vascularized tissue to minimize the risk of intracranial infection.

Endoscopic Endonasal Surgery for Remission of Cushing Disease Caused by Ectopic Intracavernous Macroadenoma: Case Report and Literature Review.

BACKGROUND: Complete surgical resection of an adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma is the gold standard of treatment of Cushing disease. Ectopic location of these adenomas is an extremely rare condition that may compromise the diagnosis and surgical success. We present the first case of an ectopic intracavernous ACTH-secreting macroadenoma totally resected with endoscopic endonasal surgery (EES). CASE DESCRIPTION: A 36-year-old woman presented with Cushing syndrome. Increased ACTH, serum cortisol, and free urine cortisol levels were identified; however, pituitary magnetic resonance imaging failed to show a pituitary tumor; instead, a parasellar lesion in the left cavernous sinus (CS) was noticed. Inferior petrosal sinus sampling showed a significant central to peripheral and lateralized left-sided ACTH gradient. The patient underwent EES. No tumor was found in the sella; however, the left CS was widely explored and a tumor was found lateral to the paraclival segment of the carotid artery. There were no complications after EES. Pathology confirmed the diagnosis of an ACTH-secreting adenoma. During the immediate postoperative course, serum cortisol levels decreased lower than 5 µg/dL. Postoperative magnetic resonance imaging showed complete tumor resection. At 20 months follow-up, the patient remained in clinical and biochemical remission of Cushing disease. CONCLUSIONS: Only 12 cases of ectopic intracavernous ACTH-secreting adenomas have been reported and all were microadenomas. The presence of an ectopic ACTH-secreting macroadenoma in the CS represents a surgical challenge. EES is the ideal approach for complete resection of ectopic intracavernous adenomas, allowing for a wide exploration of the CS with no surgical complications.

Endoscopic Endonasal Surgery for Cranial Base Chondrosarcomas.

BACKGROUND: Microsurgical resection via open approaches is considered the main treatment modality for cranial base chondrosarcomas (CBCs). The use of endoscopic endonasal approaches (EEAs) has been rarely reported. OBJECTIVE: To present the endoscopic endonasal experience with CBCs at our institution. METHODS: Retrospective review of the medical records of 35 consecutive patients who underwent EEA for CBC resection between January 2004 and April 2013. Surgical outcomes and variables that might affect extent of resection, complications, and recurrence were analyzed. RESULTS: Forty-eight operations were performed (42 EEAs and 6 open approaches). Gross-total resection was achieved in 22 patients (62.9%), near total (≥90% tumor resection) in 11 (31.4%). Larger tumors were associated with incomplete resection in univariate and multivariate analysis ( P = .004, .015, respectively). In univariate analysis, tumors involving the lower clivus and cerebellopontine angle were associated with increased number of complications, especially postoperative cerebrospinal fluid leak ( P = .015) and new cranial neuropathy ( P = .037), respectively. Other major complications included 2 cases of meningitis and deep venous thrombosis, and 1 case of hydrocephalus and carotid injury. Involvement of the lower clivus, parapharyngeal space, and cervical spine required a combination of approaches to maximize tumor resection ( P = .017, .044, .017, respectively). No predictors were significantly associated with increased risk of recurrence. The average follow-up time was 44.6 ± 31 months. CONCLUSIONS: EEAs may be considered a good option for managing CBCs without significant posterolateral extension beyond the basal foramina and can be used in conjunction with open approaches for maximal resection with acceptable morbidity.

Endoscopic Endonasal Surgery for Tumors of the Cavernous Sinus: A Series of 234 Patients.

BACKGROUND: Cavernous sinus (CS) tumors often are considered inoperable. We present our experience with endoscopic endonasal surgery (EES) and compare the outcomes for different tumor. METHODS: EES (medial or lateral approach) was used in 234 patients with CS tumors. The cohort included 175 (75%) pituitary adenomas and 59 (25%) nonadenomatous lesions. RESULTS: Presenting symptoms were significantly different between the 2 groups, with cranial neuropathies occurring mainly in nonadenomas (P < 0.0001). The overall gross total tumor resection rate from the CS was 37.3% (37.1% in adenomas, 38.1% in non-adenomas). In total, preexisting cranial nerve (CN) dysfunction improved in 56.4% of the patients. After treatment completion (including radiation of residual tumor), 83.3% of acromegalic patients, 50% of prolactinomas and 33.3% of Cushing's disease, were in remission. Visual loss improved in 86.8% of adenomas and in 70.8% of nonadenomas. Intracavernous CN palsies improved in 77.3% of adenomas and 42.4% of nonadenomas. New permanent CN palsies occurred in 7 nonadenomas, which is significantly greater than in adenomas (P = 0.007). The leak rate of cerebrospinal fluid was 6.3% for adenomas and 11.9% for nonadenomas. Four patients suffered an internal carotid artery injury with no neurologic sequelae in 3 cases and 1 death (0.4%). CONCLUSIONS: EES provides an easily accessible midline corridor to the CS with equivalent or superior results to transcranial approaches in the management of select tumors. Symptomatology due to CS invasion is more likely to improve in pituitary adenomas and the rate of surgical complications is greater in nonadenomas. Using a team approach, the overall mortality due to vascular injury is low.

Outcomes of Endonasal and Lateral Approaches to Petroclival Meningiomas.

OBJECTIVE: Transpetrosal approaches for the treatment of petroclival meningiomas are often associated with substantial morbidity and long recovery. With the goal of early clinical improvement, we have used less invasive surgical approaches for petroclival meningiomas. METHODS: We retrospectively reviewed 32 patients with petroclival meningiomas. Eleven patients (34.4%) were managed with lateral approaches (retrosigmoid or far lateral approach), 17 (53.1%) with anterior midline approaches (endoscopic endonasal approach [EEA]), and 4 (12.5%) with a combination. RESULTS: The average Karnofsky Performance Score (KPS) at presentation was 73.8. The average postoperative KPS improved to 87.9 (P < 0.001) during short-term follow-up of 14 months (range, 1-42) and was significantly higher in primary tumors (P = 0.013), tumors <4 cm (P = 0.039), and tumors without vascular encasement (P = 0.002) but remained significant regardless of age, tumor size, or vascular encasement. The greatest benefit occurred with primary tumors, in young patients and in those who underwent nontotal resection (P < 0.001). EEA had a significantly greater potential for improved KPS (P = 0.002). Gross (n = 6) or near total (n = 9) resection was achieved in 15 of 32 cases (47%). Complications included new cranial nerve palsies affecting mainly the abducens nerve (18.7%). New lower cranial nerve palsies occurred in only 1 case (3.1%). Other complications included postoperative hydrocephalus (15.6%) and cerebrospinal fluid leak (28.1%). One patient died in the perioperative period (3.1%). CONCLUSIONS: In the short-term, less aggressive cranial base approaches, including retrosigmoid exposures and the recently introduced EEA, are effective alternatives to transpetrosal approaches for debulking petroclival meningiomas with significant early clinical improvement and limited major surgical complications.

Endoscopic Endonasal Clipping of Intracranial Aneurysms: Surgical Technique and Results.

OBJECTIVE: Microsurgical clipping of intracranial aneurysms requires meticulous technique and is usually performed through open approaches. Endoscopic endonasal clipping of intracranial aneurysms may use the same techniques through an alternative corridor. The aim of this article is to report a series of patients who underwent an endoscopic endonasal approach (EEA) for microsurgical clipping of intracranial aneurysms. METHODS: We conducted a retrospective chart review. Surgical outcome and complications were noted. The conceptual application and the technical nuances of these procedures are discussed. RESULTS: Ten patients underwent EEA for clipping of 11 intracranial aneurysms arising from the paraclinoidal internal carotid artery (n = 9) and vertebrobasilar system (n = 2). The internal carotid artery aneurysms projected medially, whereas the vertebrobasilar artery aneurysms were directly ventral to the brainstem with low-lying basilar apices. One patient required craniotomy for distal control given the size and thrombosed nature of the aneurysm. Proximal and distal vascular control with direct visualization of the aneurysm was obtained in all patients. In all cases, aneurysms were completely occluded. Among complications, 3 patients had postoperative cerebrospinal fluid leakage and 2 other patients had meningitis. Two patients suffered lacunar strokes. One recovered completely and the other remains with mild disabling symptoms. CONCLUSIONS: EEAs can provide direct access for microsurgical clipping of rare and carefully selected intracranial aneurysms. The basic principles of cerebrovascular surgery have to be followed throughout the procedure. These surgeries require a skull base team with a neurosurgeon well versed in both endoscopic endonasal and cerebrovascular surgery, working in concert with an otolaryngologist experienced in skull base endoscopy and reconstruction.

Atlanto-occipital Instability Following Endoscopic Endonasal Approach for Lower Clival Lesions: Experience With 212 Cases.

BACKGROUND: The endoscopic endonasal approach (EEA) for craniocervical lesions involving the lower clivus and occipital condyles carries an unclear risk of atlanto-occipital (AO) instability requiring arthrodesis. OBJECTIVE: Elucidate risk factors for AO instability following EEA for clival lesions. METHODS: We reviewed patients with clival tumors who underwent EEA at our institution between 2002 and 2012. Resection of the lower clivus, foramen magnum, AO joint, and occipital condyles were evaluated on fine-cut postoperative computed tomography. RESULTS: Two hundred twelve patients (mean age 47.9 years, 57.1% male) underwent transclival EEA for lower clival lesions. In addition to the lower clivus, resection involved the condyle in 14.2% of patients, the foramen magnum in 16.5%, and the AO joint in 1.4%. Quantification of condyle resection revealed complete resection in 3 cases, 75% resection in 8 cases, 50% resection in 6 cases, and 25% resection in 13 cases. Seven of these patients had EEA combined with an open, far-lateral approach. In total, 7 patients required arthrodesis following EEA (3.3%), 4 of them after a combined approach. All patients who underwent arthrodesis had primary bone tumors such as chordoma, chondrosarcoma, or osteosarcoma (P = .022). Degree of condyle resection was a significant factor predisposing to occipitocervical instability (P = .001 and P < .001 for 75% and 100% condyle resection, respectively). Use of a combined approach was significantly associated with arthrodesis (P < .001). CONCLUSION: EEA resection of the occipital condyles that results in greater than 75% condyle resection or EEA in combination with an open approach significantly increases the risk of AO instability and likely necessitates AO fixation. ABBREVIATIONS: AO, atlanto-occipitalEEA, endoscopic endonasal approachOC, occipitocervical.

Endoscopic Endonasal Approach to the Optic Canal: Anatomic Considerations and Surgical Relevance.

BACKGROUND: Increasing use of endoscopic endonasal surgery for suprasellar lesions with extension into the optic canal (OC) has necessitated a better endonasal description of the OC. OBJECTIVE: To identify the osseous OC transcranially and then investigate its anatomic relationship to the key endonasal intrasphenoidal landmarks. We also aimed to determine and describe the technical nuances for safely opening the falciform ligament and intracanalicular dura (surrounding the optic nerve [ON]) endonasally. METHODS: Ten fresh human head silicon-injected specimens underwent an endoscopic transtuberculum/transplanum approach followed by 2-piece orbitozygomatic craniotomy to allow identification of 20 OCs. After completing up to 270° of endonasal bony decompression of the OC, a dural incision started at the sella and continued superiorly across the superior intercavernous sinus. Subsequently the dural opening was extended anterolaterally across the dura of the prechiasmatic sulcus, limbus sphenoidale, and planum. RESULTS: Endonasally, the length of the osseous OC was approximately 6 mm and equivalent to the length of the lateral opticocarotid recess, as measured anteroposteriorly. The ophthalmic artery arose from the supraclinoidal carotid artery at approximately 2.5 mm from the medial osseous OC entrance. Transcranial correlation of the endonasal dural incision confirmed medial detachment of the falciform ligament and exposure of the preforaminal ON. CONCLUSION: The lateral opticocarotid recess allows distinction of the preforaminal ON, roofed by the falciform ligament from the intracanalicular segment in the osseous OC. This facilitates the preoperative surgical strategy regarding the extent of OC decompression and dural opening. Extensive endonasal decompression of the OC and division of the falciform ligament is feasible.

Endonasal endoscopic surgery for squamous cell carcinoma of the sinonasal cavities and skull base: Oncologic outcomes based on treatment strategy and tumor etiology.

BACKGROUND: Oncologic outcomes for sinonasal and skull base squamous cell carcinoma (SCC) treated with an endoscopic endonasal approach (EEA) needs investigation. METHODS: Patients with SCC treated with EEA were stratified by treatment strategy and tumor etiology and reviewed. RESULTS: Thirty-four patients were treated with EEA, or which 27 had definitive resection and 7 had debulking surgery. In the definitive group, 17 had de novo tumors and 10 had tumors arising from inverted papilloma. Definitive resection was associated with better 5-year disease-free survival (DFS) and overall survival (OS) than debulking (62% vs 17%; p = .02; and 78% vs 30%; p = .03). Patients with de novo tumors had similar 5-year DFS and OS to those arising from inverted papilloma (62% vs 62%; p = .75; and 75% vs 86%; p = .24). CONCLUSION: Definitive resection of sinonasal SCC with EEA provides sound oncologic outcomes. SCC arising from inverted papilloma does not have prognostic significance.