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.

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 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.

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 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.

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.

Comparison of endoscopic endonasal and bifrontal craniotomy approaches for olfactory groove meningiomas: A matched pair analysis of outcomes and frontal lobe changes on MRI

We compare the outcomes and postoperative MRI changes of endoscopic endonasal (EEA) and bifrontal craniotomy (BFC) approaches for olfactory groove meningiomas (OGM). All patients who underwent either BFC or EEA for OGM were eligible. Matched pairs were created by matching tumor volumes of an EEA patient with a BFC patient, and matching the timing of the postoperative scans. The tumor dimensions, peritumoral edema, resectability issues, and frontal lobe changes were recorded based on preoperative and postoperative MRI. Postoperative fluid-attenuated inversion recovery (FLAIR) hyperintensity and residual cystic cavity (porencephalic cave) volume were compared using univariable and multivariable analyses. From a total of 70 patients (46 EEA, 24 BFC), 10 matched pairs (20 patients) were created. Three patients (30%) in the EEA group and two (20%) in the BFC had postoperative cerebrospinal fluid leaks (p=0.61). Gross total resections were achieved in seven (70%) of the EEA group and nine (90%) of the BFC group (p=0.26), and one patient from each group developed a recurrence. On postoperative MRI, there was no significant difference in FLAIR signal volumes between EEA and BFC approaches (6.9 versus 13.3 cm(3); p=0.17) or in porencephalic cave volumes (1.7 versus 5.0 cm(3); p=0.11) in univariable analysis. However, in a multivariable analysis, EEA was associated with less postoperative FLAIR change (p=0.02) after adjusting for the volume of preoperative edema. This study provides preliminary evidence that EEA is associated with quantifiable improvements in postoperative frontal lobe imaging.

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.

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.

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.

Endoscopic endonasal transcavernous posterior clinoidectomy with interdural pituitary transposition

OBJECT.: The object of this paper was to describe the surgical anatomy and technical nuances of the endonasal transcavernous posterior clinoidectomy approach with interdural pituitary transposition and to report the clinical outcome of this technical modification.

METHODS

The surgical anatomy of the proposed approach was studied in 10 colored silicon-injected anatomical specimens. The medical records of 12 patients that underwent removal of the posterior clinoid(s) with this technique were reviewed.

RESULTS

The natural anatomical corridor provided by the cavernous sinus is used to get access to the posterior clinoid by mobilizing the pituitary gland in an interdural fashion. The medial wall of the cavernous sinus is preserved intact and attached to the gland during its medial and superior mobilization. This provides protection to the gland, allowing for preservation of its venous drainage pathways. The inferior hypophyseal artery is transected to facilitate the manipulation of the medial wall of the cavernous sinus and pituitary gland. This approach was successfully performed in all patients, including 6 with chordomas, 5 with petroclival meningiomas, and 1 with an epidermoid tumor. No patient in this series had neurovascular injury related to the posterior clinoidectomy. There were no instances of permanent hypopituitarism or diabetes insipidus.

CONCLUSIONS

The authors introduce a surgical variant of the endoscopic endonasal posterior clinoidectomy approach that does not require intradural pituitary transposition and is more effective than the purely extradural approach. The endoscopic endonasal transcavernous approach facilitates the removal of prominent posterior clinoids increasing the working space at the lateral recess of the interpeduncular cistern, while preserving the pituitary function.

Endoscopic endonasal surgery for suprasellar meningiomas: experience with 75 patients

OBJECT

Following the introduction of the neurosurgical microscope, the outcomes in suprasellar meningioma surgery were dramatically improved. More recently, the neurosurgical endoscope has been introduced as a visualization option during removal of skull base tumors, both transcranially and endonasally. The authors retrospectively reviewed the effectiveness of endoscopic endonasal surgery (EES) in the management of suprasellar meningiomas.

METHODS

Between 2002 and 2011, 75 patients (81.3% female) with suprasellar meningiomas underwent EES at the University of Pittsburgh Medical Center. The authors present the results of EES and analyze the resection rates, visual outcome, and complications.

RESULTS

Seventy-one patients presented with primary tumors, whereas 4 were previously treated elsewhere. Their mean age was 57.3 years (range 36-88 years), and most patients presented with visual loss (81.3%). Tumors occupied the tuberculum sellae (86.7%) and planum sphenoidale (50.7%), with extension into the optic canals in 26.7% (unilateral in 21.3% and bilateral in 5.3%) and the pituitary fossa (9.3%). Gross-total tumor resection (Simpson Grade I) was achieved in 76% of the cases in the whole cohort and in 81.4% of the patients in whom it was the goal of surgery. Tumor location and extension into the optic canals was not a limitation for total resection. Tumor size, configuration, and vascular encasement were significant factors that influenced the degree of resection (p < 0.0001). Vision was improved or normalized in 85.7% of the cases. Visual deterioration following EES occurred in 2 patients (3.6%). Complications included postoperative CSF leaks (25.3% overall, 16.1% in recent years) resulting in meningitis in 4 cases. One patient had an intraoperative injury of the artery of Heubner resulting in associated neurological deficit. Another elderly patient died within 1 month after EES due to cerebral vasospasm and multisystem impairment. No patient developed postoperative cerebral contusions, hemorrhage, or seizures. During a mean follow-up period of 29 months (range 1-98 months), 4 patients have shown recurrence, but only 1 required repeat EES.

CONCLUSIONS

With the goal of gross-total tumor resection and visual improvement, EES can achieve very good results, (comparable to microscopic approaches) for the treatment of suprasellar meningiomas. Avoidance of brain and optic nerve retraction, preservation of the vascularization of the optic apparatus, and wide decompression of the optic canals are the main advantages of EES for the treatment of suprasellar meningiomas, while CSF leaks remain a disadvantage.

Pontine encephalocele and abnormalities of the posterior fossa following transclival endoscopic endonasal surgery

OBJECT

Transclival endoscopic endonasal surgery (EES) has recently been used for the treatment of posterior fossa tumors. The optimal method of reconstruction of large clival defects following EES has not been established.

METHODS

A morphometric analysis of the posterior fossa was performed in patients who underwent transclival EES to compare those with observed postoperative anatomical changes (study group) to 50 normal individuals (anatomical control group) and 41 matched transclival cases with preserved posterior fossa anatomy (case-control group) using the same parameters. Given the absence of clival bone following transclival EES, the authors used the line between the anterior commissure and the basion as an equivalent to the clival plane to evaluate the location of the pons. Four parameters were studied and compared in the two populations: the pontine location/displacement, the maximum anteroposterior (AP) diameter of the pons, the maximum AP diameter of the fourth ventricle, and the cervicomedullary angle (CMA). All measurements were performed on midsagittal 3-month postoperative MR images in the study group.

RESULTS

Among 103 posterior fossa tumors treated with transclival EES, 14 cases (13.6%) with postoperative posterior fossa anatomy changes were identified. The most significant change was anterior displacement of the pons (transclival pontine encephalocele) compared with the normal location in the anatomical control group (p < 0.0001). Other significant deformities were expansion of the AP diameter of the pons (p = 0.005), enlargement of the fourth ventricle (p = 0.001), and decrease in the CMA (p < 0.0001). All patients who developed these changes had undergone extensive resection of the clival bone (> 50% of the clivus) and dura. Nine (64.3%) of the 14 patients were overweight (body mass index [BMI] > 25 kg/m(2)). An association between BMI and the degree of pontine encephalocele was observed, but did not reach statistical significance. The use of a fat graft as part of the reconstruction technique following transclival EES with dural opening was the single significant factor that prevented pontine displacement (p = 0.02), associated with 91% lower odds of pontine encephalocele (OR = 0.09, 95% CI 0.01-0.77). The effect of fat graft reconstruction was more pronounced in overweight/obese individuals (p = 0.04) than in normal-weight patients (p = 0.52). Besides reconstruction technique, other noticeable findings were the tendency of younger adults to develop pontine encephalocele (p = 0.05) and the association of postoperative meningitis with the development of posterior fossa deformities (p = 0.05). One patient developed a transient, recurrent subjective diplopia; all others remained asymptomatic.

CONCLUSIONS

Significant changes in posterior fossa anatomy that have potential clinical implications have been observed following transclival transdural EES. These changes are more common in younger patients or those with meningitis and may be associated with BMI. The use of a fat graft combined with the vascularized nasoseptal flap appears to minimize the risk of pontine herniation following transclival EES with dural opening.

Endoscopic endonasal surgery for craniopharyngiomas: surgical outcome in 64 patients

OBJECT

The proximity of craniopharyngiomas to vital neurovascular structures and their high recurrence rates make them one of the most challenging and controversial management dilemmas in neurosurgery. Endoscopic endonasal surgery (EES) has recently been introduced as a treatment option for both pediatric and adult craniopharyngiomas. The object of the present study was to present the results of EES and analyze outcome in both the pediatric and the adult age groups.

METHODS

The authors retrospectively reviewed the records of patients with craniopharyngioma who had undergone EES in the period from June 1999 to April 2011.

RESULTS

Sixty-four patients, 47 adults and 17 children, were eligible for this study. Forty-seven patients had presented with primary craniopharyngiomas and 17 with recurrent tumors. The mean age in the adult group was 51 years (range 28-82 years); in the pediatric group, 9 years (range 4-18 years). Overall, the gross-total resection rate was 37.5% (24 patients); near-total resection (> 95% of tumor removed) was 34.4% (22 patients); subtotal resection (≥ 80% of tumor removed) 21.9% (14 patients); and partial resection (< 80% of tumor removed) 6.2% (4 patients). In 9 patients, EES had been combined with radiation therapy (with radiosurgery in 6 cases) as the initial treatment. Among the 40 patients (62.5%) who had presented with pituitary insufficiency, pituitary function remained unchanged in 19 (47.5%), improved or normalized in 8 (20%), and worsened in 13 (32.5%). In the 24 patients who had presented with normal pituitary function, new pituitary deficit occurred in 14 (58.3%). Nineteen patients (29.7%) suffered from diabetes insipidus at presentation, and the condition developed in 21 patients (46.7%) after treatment. Forty-four patients (68.8%) had presented with impaired vision. In 38 (86.4%) of them, vision improved or even normalized after surgery; in 5, it remained unchanged; and in 1, it temporarily worsened. One patient without preoperative visual problems showed temporary visual deterioration after treatment. Permanent visual deterioration occurred in no one after surgery. The mean follow-up was 38 months (range 1-135 months). Tumor recurrence after EES was discovered in 22 patients (34.4%) and was treated with repeat surgery (6 patients), radiosurgery (1 patient), combined repeat surgery and radiation therapy (8 patients), interferon (1 patient), or observation (6 patients). Surgical complications included 15 cases (23.4%) with CSF leakage that was treated with surgical reexploration (13 patients) and/or lumbar drain placement (9 patients). This leak rate was decreased to 10.6% in recent years after the introduction of the vascularized nasoseptal flap. Five cases (7.8%) of meningitis were found and treated with antibiotics without further complications. Postoperative hydrocephalus occurred in 7 patients (12.7%) and was treated with ventriculoperitoneal shunt placement. Five patients experienced transient cranial nerve palsies. There was no operative mortality.

CONCLUSIONS

With the goal of gross-total or maximum possible safe resection, EES can be used for the treatment of every craniopharyngioma, regardless of its location, size, and extension (excluding purely intraventricular tumors), and can provide acceptable results comparable to those for traditional craniotomies. Endoscopic endonasal surgery is not limited to adults and actually shows higher resection rates in the pediatric population.