JNSPG 75th Anniversary Invited Review Article
Theodore H. Schwartz, Peter F. Morgenstern and Vijay K. Anand
Endoscopic skull base surgery (ESBS) is a relatively recent addition to the neurosurgical armamentarium. As with many new approaches, there has been significant controversy regarding its value compared with more traditional approaches to ventral skull base pathology. Although early enthusiasm for new approaches that appear less invasive is usually high, these new techniques require rigorous study to ensure that widespread implementation is in the best interest of patients.
The authors compared surgical results for ESBS with transcranial surgery (TCS) for several different pathologies over two different time periods (prior to 2012 and 2012–2017) to see how results have evolved over time. Pathologies examined were craniopharyngioma, anterior skull base meningioma, esthesioneuroblastoma, chordoma, and chondrosarcoma.
ESBS offers clear advantages over TCS for most craniopharyngiomas and chordomas. For well-selected cases of planum sphenoidale and tuberculum sellae meningiomas, ESBS has similar rates of resection with higher rates of visual improvement, and more recent results with lower CSF leaks make the complication rates similar between the two approaches. TCS offers a higher rate of resection with fewer complications for olfactory groove meningiomas. ESBS is preferred for lower-grade esthesioneuroblastomas, but higher-grade tumors often still require a craniofacial approach. There are few data on chondrosarcomas, but early results show that ESBS appears to offer clear advantages for minimizing morbidity with similar rates of resection, as long as surgeons are familiar with more complex inferolateral approaches.
ESBS is maturing into a well-established approach that is clearly in the patients’ best interest when applied by experienced surgeons for appropriate pathology. Ongoing critical reevaluation of outcomes is essential for ensuring optimal results.
Ilya Laufer, Vijay K. Anand and Theodore H. Schwartz
The extended transsphenoidal approach is a less invasive method for removing purely suprasellar lesions compared with traditional transcranial approaches. Most advocates have used a sublabial incision and a microscope and have reported a significant risk of cerebrospinal fluid (CSF) leakage. The authors report on a series of purely endoscopic endonasal surgeries for resection of suprasellar supradiaphragmatic lesions above a normal-sized sella turcica with a low risk of CSF leakage.
A purely endoscopic endonasal approach was used to remove suprasellar lesions in a series of 10 patients. Five lesions were prechiasmal (three tuberculum sellae and two planum sphenoidale meningiomas) and five were post-chiasmal (four craniopharyngiomas and one Rathke cleft cyst). The floor of the planum sphenoidale and the sella turcica was reconstructed using a multilayer closure with autologous and synthetic materials. Spinal drainage was performed in only five cases. Complete resection of the lesions was achieved in all but one patient. The pituitary stalk was preserved in all but one patient, whose stalk was invaded by a craniopharyngioma and who had preoperative diabetes insipidus (DI). Vision improved postoperatively in all patients with preoperative impairment. Six patients had temporary DI; in five, the DI became permanent. Four patients with craniopharyngiomas required cortisone and thyroid replacement. After a mean follow up of 10 months, there was only one transient CSF leak when a lumbar drain was clamped prematurely on postoperative Day 5.
A purely endoscopic endonasal approach to suprasellar supradiaphragmatic lesions is a feasible minimally invasive alternative to craniotomy. With a multilayer closure, the risk of CSF leakage is low and lumbar drainage can be avoided. A larger series will be required to validate this approach.
Tomasz A. Dziedzic, Vijay K. Anand and Theodore H. Schwartz
Although the medial and inferior orbital apex are considered safely accessible using the endonasal endoscopic approach, the lateral apex has been considered unsafe to access since the optic nerve lies between the surgeon and the pathology. The authors present the case of a 4-year-old girl with recurrent rhabdomyosarcoma attached to the lateral rectus muscle located lateral and inferior to the optic nerve in the orbital apex. The tumor was totally resected through an endoscopic endonasal transmaxillary transpterygoidal approach using a 45° endoscope. A gross-total resection was achieved, and the patient’s vision was unchanged. This procedure is a safe, minimal-access alternative to open procedures in selected cases and provides evidence that increases the applicability of the endonasal endoscopic approach to reach the lateral compartment of the orbital apex.
Case report and review of the literature
Justin F. Fraser, Vijay K. Anand and Theodore H. Schwartz
✓The authors present the case of a 71-year-old man who presented with neck pain, a history of gout, and a mass in the dens. Results of transoral endoscopic biopsy sampling demonstrated tophaceous gout. The patient was treated medically and the pain resolved. Tophaceous gout isolated in the dens is extremely rare and should be considered in the differential diagnosis of masses in this region. With the aid of transoral or transnasal endoscopic biopsy sampling, the diagnosis can be reached in a minimally invasive manner.
Edward D. McCoul, Vijay K. Anand and Theodore H. Schwartz
Endoscopic skull base surgery (ESBS) is a minimal-access technique that provides an alternative to traditional approaches. Patient-reported outcomes are becoming increasingly important in measuring the success of surgical interventions. Endoscopic skull base surgery may lead to improvements in quality of life (QOL) since natural orifices are used to reach the pathology; however, sinonasal QOL may be negatively affected. The purpose of this study was to assess the impact of ESBS on both site-specific QOL, using the Anterior Skull Base Questionnaire (ASBQ), and sinonasal-related QOL, using the Sino-Nasal Outcome Test (SNOT-22).
Consecutive patients from a tertiary referral center who were undergoing ESBS were prospectively enrolled in this study. All patients completed the ASBQ and SNOT-22 preoperatively as well as at regular intervals after ESBS.
Sixty-six patients were included in the study, and 57.6% of them had pituitary adenoma. There was no significant decline or improvement in the ASBQ-measured QOL at 3 and 6 weeks after ESBS, but there were significant improvements at 12 weeks and 6 months postoperatively (p < 0.05). Improvements were noted in all but one ASBQ subdomain at 12 weeks and 6 months postsurgery (p < 0.05). Preoperative QOL was significantly worse in patients who had undergone revision surgery and significantly improved postoperatively in patients who underwent gross-total resection (p < 0.05). Scores on the SNOT-22 worsened at 3 weeks postoperatively and returned to baseline thereafter. The presence of a nasoseptal flap or a graft-donor site did not contribute to a decreased QOL.
Endoscopic skull base surgery is associated with an improvement in postoperative site-specific QOL as compared with the preoperative QOL. Short-term improvements are greater if gross-total resection is achieved. Sinonasal QOL transiently declines and then returns to preoperative baseline levels. Endoscopic skull base surgery is a valuable tool in the neurosurgical management of anterior skull base pathology, leading to improvements in site-specific QOL.
Osaama H. Khan, M.Sc., Vijay K. Anand and Theodore H. Schwartz
This paper describes a consecutive series of skull base meningiomas resected using an endoscopic endonasal approach through various corridors at a single institution over 7 years. The impact of case selection and experience, the presence of a cortical cuff between the tumor and surrounding vessels, and brain edema on morbidity and rates of gross-total resection (GTR) were examined.
A retrospective review of a series of 46 skull base meningiomas from a prospective database was conducted. The series of cases were divided by location: olfactory groove (n = 15), tuberculum and planum (n = 20), sellar/cavernous (n = 9) and petroclival (n = 2). Gross-total resection was never intended in the sellar/cavernous tumors, which generally invaded the cavernous sinus. Clinical charts, volumetric imaging, and pathology were reviewed to assess the extent of resection and complications. Cases were divided based on a time point in which surgical technique and case selection improved into Group 1 (surgery prior to June 2008; n = 21) and Group 2 (surgery after June 2008; n = 25) and into those with and without a cortical cuff and with and without brain edema.
Improved case selection had the greatest impact on extent of resection. For the entire cohort, rates of GTR went from 38% to 76% (p = 0.02), and for cases in which GTR was the intent, the rates went from 63% to 84% (not significant), which was mostly driven by the planum and tuberculum meningiomas, which went from 75% to 91.7 % (nonsignificant difference). The presence of a cortical cuff and brain edema had no impact on outcomes. There were 3 CSF leaks (6.5%) but all were in Group 1. Hence, CSF leak improved from 14.2% to 0% with surgical experience. Lessons learned for optimal case selection are discussed.
Surgical outcome for endonasal endoscopic resection of skull base meningiomas depends mostly on careful case selection and surgical experience. Imaging criteria such as the presence of a cortical cuff or brain edema are less important.
Peter J. Wilson, Sacit B. Omay, Ashutosh Kacker, Vijay K. Anand and Theodore H. Schwartz
Pituitary adenomas are benign, slow-growing tumors that cause symptoms either through mass effect or hormone overproduction. The decision to operate on a healthy young person is relatively straightforward. In the elderly population, however, the risks of complications may increase, rendering the decision more complex. Few studies have documented the risks of surgery using the endonasal endoscopic approach in a large number of elderly patients. The purpose of this study was to audit a single center's data regarding outcomes of purely endoscopic endonasal transsphenoidal resection of pituitary adenomas in elderly patients and to compare them to the current literature.
A retrospective review of a prospectively acquired database of all endonasal endoscopic surgeries done by the senior authors was queried for patients aged 60–69 years and for those aged 70 years or older. Demographic and radiographic preoperative data were reviewed. Outcomes with respect to extent of resection and complications were examined and compared with appropriate statistical tests.
A total of 135 patents were identified (81 aged 60–69 years and 54 aged 70 years or older [70+]). The average tumor diameter was slightly larger for the patients in the 70+ age group (mean [SD] 25.7 ± 9.2 mm) than for patients aged 60–69 years (23.1 ± 9.8 mm, p = 0.056). There was no significant difference in intraoperative blood loss (p > 0.99), length of stay (p = 0.22), or duration of follow-up (p = 0.21) between the 2 groups. There was a 7.4% complication rate in patients aged 60–69 years (3 nasal and 3 medical complications) and an 18.5% complication rate in patients older than 70 years (4 cranial, 3 nasal, 1 visual, and 2 medical complications; p = 0.05 overall and 0.013 for cranial complications). Cranial complications in the 70+ age category included 2 postoperative hematomas, 1 pseudoaneurysm formation, and 1 case of symptomatic subdural hygromas.
Endonasal endoscopic surgery in elderly patients is safe, but there is a graded increase in complication rates with increasing age. The decision to operate on an asymptomatic or mildly symptomatic patient in these age groups should take this increasing complication rate into account. The use of a lumbar drain or lumbar punctures should be weighed against the risk of subdural hematoma in patients with preexisting atrophy.
Jeffrey C. Bedrosian, Victor Garcia-Navarro, Edward D. McCoul, Vijay K. Anand and Theodore H. Schwartz
Cholesterol granulomas (CGs) are benign, expanding cystic lesions surrounded by a thick fibrous capsule and filled with fluid, formed by the degradation of blood elements. The goal of surgery is to open the granuloma widely, creating a well-drained cavity. The endonasal endoscopic approach for this extradural lesion is a minimal access method for surgical removal or fenestration. The role of balloon dilation in creating a wide fenestration has not been previously described.
The authors describe a patient with a recurrent petrous apex CG who underwent an endoscopic, endonasal, transmaxillary transpterygoid approach to the petrous apex. A balloon sinuplasty catheter was used to dilate the surgical fenestration to maintain continued patency.
The authors report on their first experience using balloon dilation combined with endoscopic drainage of the petrous apex. The excellent surgical outcome of this minimally invasive technique holds promise for future endonasal approaches to the middle cranial fossa.
Richard D. Murray, Rachel Friedlander, Samuel Hanz, Harminder Singh, Vijay K. Anand and Theodore H. Schwartz
The anterior skull base is a common site for the spontaneous development of meningoceles, encephaloceles, and meningoencephaloceles that can lead to cerebrospinal fluid (CSF) fistula formation, particularly in association with idiopathic intracranial hypertension. In some circumstances the lesions are difficult to localize. Whether all sites in the anterior skull base are equally prone to fistula formation or whether they are distributed randomly throughout the anterior skull base is unknown, although the anterior cribriform plate has been proposed as the most frequent location. The purpose of this study was to identify sites of predilection in order to provide assistance for clinicians in finding occult leaks and increase the understanding of the etiology of this pathology.
The authors performed a retrospective review of a prospectively acquired surgical database of all endonasal endoscopic surgeries performed at Weill Cornell Medical College by the senior authors. Spontaneous CSF fistulas of the anterior skull base were identified. The anatomical sites of the defects were located on radiographic images and normalized to a theoretical 4 × 2 grid representing the anterior midline skull base. Data from the left and right skull base were combined to increase statistical power. This grid was then used to analyze the distribution of defects. Frequency analysis was performed by means of a chi-square test, with a subsequent Monte Carlo simulation to further strengthen the statistical support of the conclusions.
Nineteen cases of spontaneous CSF fistulas were identified. Frequency analysis using chi-square indicated a nonrandom distribution of sites (p = 0.035). Monte Carlo simulation supported this conclusion (p = 0.034). Seventy-four percent of cases occurred in the cribriform plate (p = 0.086). Moreover, 37% of all defects occurred in the posterior third of the cribriform plate.
Anterior skull base spontaneous CSF leaks are distributed in a nonrandom fashion. The most likely site of origin of the spontaneous CSF leaks of the anterior midline skull base is the cribriform plate, particularly the posterior third of the plate, likely because of the lack of significant thick bony buttressing. Clinicians searching for occult spontaneous leaks of the anterior skull base should examine the cribriform plate, especially the posterior third with particularly close scrutiny.