Endoscopic endonasal approach for infradiaphragmatic craniopharyngiomas: a multicentric Italian study

J Neurosurg 138:522–532, 2023

Infradiaphragmatic craniopharyngiomas (ICs) represent a distinct subtype, harboring a sellar-suprasellar origin and generally growing in the extra-arachnoidal space contained by the diaphragma sellae. They have been considered ideal for surgical removal through the transsphenoidal approach since the 1960s. The authors present a multicentric national study, intending to selectively analyze IC behavior and the impact of the transsphenoidal endoscopic endonasal approach (EEA) on surgical outcomes.

METHODS Craniopharyngiomas that were intraoperatively recognized as infradiaphragmatic and removed with standard EEA between 2000 and 2021 at 6 Italian neurosurgical departments were included in the study. Clinical, radiological, and surgical findings and outcomes were evaluated and reviewed.

RESULTS In total, 84 patients were included, with 45.23% identified as pediatric cases and 39.28% as having recurrent tumors. The most common presenting symptoms were endocrine (75%), visual (59.52%), and hypothalamic (26.19%) disorders. ICs were classified as extending below (6 intrasellar and 41 occupying the suprasellar cistern) or above (26 obliterating the anterior recesses of the third ventricle and 11 extending up to the foramina of Monro) the chiasmatic cistern. Gross-total resection (GTR) was achieved in 54 cases (64.28%). Tumor extension above the chiasmatic cistern and calcifications were associated with lower likelihood of GTR. The cumulative rate of postoperative complications was 34.53%, with CSF leak being the most common (14.28%). Endocrine, visual, and hypothalamic functions deteriorated postoperatively in 41/78 patients (52.56%), 5/84 (5.95%), and 14/84 (16.67%), respectively. Twenty-eight patients (33.33%) had recurrence during follow-up (mean 63.51 months), with a mean 5-year progression-free survival (PFS) rate of 58%. PFS was greater in patients who achieved GTR than patients with other extent of resection.

CONCLUSIONS This is the largest series in the literature to describe ICs removed with standard EEA, without the need for additional bone and dural opening over the planum sphenoidale. EEA provides a direct route to ICs, the opportunity to manage lesions extending up to the third ventricle without breaching the diaphragma, and high rates of GTR and satisfactory clinical outcomes. Increased surgical complexity and morbidity should be expected in patients with extensive suprasellar extension and involvement of the surrounding vital neurovascular structures.

Dumbbell-shaped pituitary adenomas: prognostic factors for prediction of tumor nondescent of the supradiaphragmal component from a multicenter series

J Neurosurg 137:609–617, 2022

Dumbbell-shaped pituitary adenomas (DSPAs) are a subgroup of macroadenomas with suprasellar extension that are characterized by a smaller diameter at the level of the diaphragma sellae opening compared with the supradiaphragmal tumor component (SDTC). Hence, DSPAs may be particularly prone to a nondescending suprasellar tumor component and risk for residual tumor or postoperative bleeding.

METHODS A multicenter retrospective cohort analysis of 99 patients with DSPA operated on via direct endoscopic endonasal transsphenoidal approach between 2011 and 2020 was conducted. Patient recruitment was performed at two tertiary care centers (Medical University of Vienna and University of Southern California) with expertise in endoscopic skull base surgery. DSPA was defined as having a smaller diameter at the level of the diaphragma sellae compared with the SDTC.

RESULTS On preoperative MRI, all DSPAs were macroadenomas (maximum diameter range 17–71 mm, volume range 2–88 cm 3 ). Tumor descent was found in 73 (74%) of 99 patients (group A), and nondescent in 26 (26%) of 99 patients (group B) intraoperatively. DSPAs in group A had a significantly smaller diameter (30 vs 42 mm, p < 0.001) and significantly smaller volume (10 vs 22 cm 3 , p < 0.001) than those in group B. The ratio of the minimum area at the level of the diaphragmal opening in comparison with the maximum area of the suprasellar tumor component (“neck-to-dome area”) was significantly lower in group A than in group B (1.7 vs 2.7, p < 0.001). Receiver operating characteristic curve analysis revealed an area under the curve of 0.75 (95% CI 0.63–0.87). At a cutoff ratio of 1.9, the sensitivity and specificity for a nondescending suprasellar tumor component were 77% and 34%, respectively.

CONCLUSIONS In the present study, the neck-to-dome area ratio was of prognostic value for prediction of intraoperative tumor nondescent in DSPAs operated on via a direct endonasal endoscopic approach. Pituitary adenoma SDTC nondescent carried the inherent risk of hemorrhagic transformation in all cases.

Evaluation of early postoperative day 1 discharge after endoscopic endonasal pituitary adenoma resection

J Neurosurg 136:1337–1346, 2022

While multiple studies have evaluated the length of stay after endonasal transsphenoidal surgery (ETS) for pituitary adenoma, the potential for early discharge on postoperative day 1 (POD 1) remains unclear. The authors compared patients discharged on POD 1 with patients discharged on POD > 1 to better characterize factors that facilitate early discharge after ETS.

METHODS A retrospective chart review was performed for patients undergoing ETS for pituitary adenoma at a single tertiary care academic center from February 2005 to February 2020. Discharge on POD 1 was defined as a discharge within 24 hours of surgery.

RESULTS A total of 726 patients (mean age 55 years, 52% male) were identified, of whom 178 (24.5%) patients were discharged on POD 1. These patients were more likely to have pituitary incidentaloma (p = 0.001), require dural substitutes and DuraSeal (p = 0.0001), have fewer intraoperative CSF leaks (p = 0.02), and have lower postoperative complication rates (p = 0.006) compared with patients discharged on POD > 1. POD 1 patients also showed higher rates of macroadenomas (96.1% vs 91.4%, p = 0.03) and lower rates of functional tumors (p = 0.02). POD > 1 patients were more likely to have readmission within 30 days (p = 0.002), readmission after 30 days (p = 0.0001), nasal synechiae on follow-up (p = 0.003), diabetes insipidus (DI; 1.7% vs 9.8%, p = 0.0001), postoperative hypocortisolism (21.8% vs 12.1%, p = 0.01), and postoperative steroid usage (44.6% vs 59.7%, p = 0.003). The number of patients discharged on POD 1 significantly increased during each subsequent time epoch: 2005–2010, 2011–2015, and 2016–2020 (p = 0.0001). On multivariate analysis, DI (OR 7.02, 95% CI 2.01–24.57; p = 0.002) and intraoperative leak (OR 2.02, 95% CI 1.25–3.28; p = 0.004) were associated with increased risk for POD > 1 discharge, while operation epoch (OR 0.46, 95% CI 0.3–0.71; p = 0.0001) was associated with POD 1 discharge.

CONCLUSIONS This study demonstrates that discharge on POD 1 after ETS for pituitary adenomas was safe and feasible and without increased risk of 30-day readmission. On multivariate analysis, surgical epoch was associated with decreased risk of prolonged length of stay, while factors associated with increased risk of prolonged length of stay included DI and intraoperative CSF leak. These findings may help in selecting patients who are deemed reasonable for safe, early discharge after pituitary adenoma resection.

The rhinopharyngeal flap for reconstruction of lower clival and craniovertebral junction defects

J Neurosurg 135:1319–1327, 2021

The endoscopic endonasal approach (EEA) to the lower clivus and craniovertebral junction (CVJ) has been traditionally performed via resection of the nasopharyngeal soft tissues. Alternatively, an inferiorly based rhinopharyngeal (RP) flap (RPF) can be dissected to help reconstruct the postoperative defect and separate it from the oropharynx. To date, there is no evidence regarding the viability and potential clinical impact of the RPF. The aim of this study was to assess RPF viability and its impact on clinical outcome.

METHODS A retrospective cohort of 60 patients who underwent EEA to the lower clivus and CVJ was studied. The RPF was used in 30 patients (RPF group), and the nasopharyngeal soft tissues were resected in 30 patients (control group).

RESULTS Chordoma was the most common surgical indication in both groups (47% in the RPF group vs 63% in the control group, p = 0.313), followed by odontoid pannus (20% in the RPF group vs 10%, p = 0.313). The two groups did not significantly differ in terms of extent of tumor (p = 0.271), intraoperative CSF leak (p = 0.438), and skull base reconstruction techniques other than the RPF (nasoseptal flap, p = 0.301; fascia lata, p = 0.791; inlay graft, p = 0.793; and prophylactic lumbar drain, p = 0.781). Postoperative soft-tissue enhancement covering the lower clivus and CVJ observed on MRI was significantly higher in the RPF group (100% vs 26%, p < 0.001). The RPF group had a significantly lower rate of nasoseptal flap necrosis (3% vs 20%, p = 0.044) and surgical site infection (3% vs 27%, p = 0.026) while having similar rates of postoperative CSF leakage (17% in the RPF group vs 20%, p = 0.739) and meningitis (7% in the RPF group vs 17%, p = 0.424). Oropharyngeal bacterial flora dominated the infections in the control group but not those in the RPF group, suggesting that the RPF acted as a barrier between the nasopharynx and oropharynx.

CONCLUSIONS The RPF provides viable vascularized tissue coverage to the lower clivus and CVJ. Its use was associated with decreased rates of nasoseptal flap necrosis and local infection, likely due to separation from the oropharynx.

Endoscopic endonasal versus transcranial surgery for primary resection of craniopharyngiomas based on a new QST classification system

J Neurosurg 135:1298–1309, 2021

An assessment of the transcranial approach (TCA) and the endoscopic endonasal approach (EEA) for craniopharyngiomas (CPs) according to tumor types has not been reported. The aim of this study was to evaluate both surgical approaches for different types of CPs.

METHODS A retrospective review of primary resected CPs was performed. A QST classification system based on tumor origin was used to classify tumors into 3 types as follows: infrasellar/subdiaphragmatic CPs (Q-CPs), subarachnoidal CPs (S-CPs), and pars tuberalis CPs (T-CPs). Within each tumor type, patients were further arranged into two groups: those treated via the TCA and those treated via the EEA. Patient and tumor characteristics, surgical outcomes, and postoperative complications were obtained. All variables were statistically analyzed between surgical groups for each tumor type.

RESULTS A total of 315 patients were included in this series, of whom 87 were identified with Q-CPs (49 treated via TCA and 38 via EEA); 56 with S-CPs (36 treated via TCA and 20 via EEA); and 172 with T-CPs (105 treated via TCA and 67 via EEA). Patient and tumor characteristics were equivalent between both surgical groups in each tumor type. The overall gross-total resection rate (90.5% TCA vs 91.2% EEA, p = 0.85) and recurrence rate (8.9% TCA vs 6.4% EEA, p = 0.35) were similar between surgical groups. The EEA group had a greater chance of visual improvement (61.6% vs 35.8%, p = 0.01) and a decreased risk of visual deterioration (1.6% vs 11.0%, p < 0.001). Of the patients with T-CPs, postoperative hypothalamic status was better in the TCA group than in the EEA group (p = 0.016). Postoperative CSF leaks and nasal complication rates occurred more frequently in the EEA group (12.0% vs 0.5%, and 9.6% vs 0.5%; both p < 0.001). For Q-CPs, EEA was associated with an increased gross-total resection rate (97.4% vs 85.7%, p = 0.017), decreased recurrence rate (2.6% vs 12.2%, p = 0.001), and lower new hypopituitarism rate (28.9% vs 57.1%, p = 0.008). The recurrence-free survival in patients with Q-CPs was also significantly different between surgical groups (log-rank test, p = 0.037). The EEA required longer surgical time for T-CPs (p = 0.01).

CONCLUSIONS CPs could be effectively treated by radical surgery with favorable results. Both TCA and EEA have their advantages and limitations when used to manage different types of tumors. Individualized surgical strategies based on tumor growth patterns are mandatory to achieve optimal outcomes.

Nasopharyngeal muscle patch for the management of internal carotid artery injury in endoscopic endonasal surgery

J Neurosurg 133:1382–1387, 2020

Injury to the internal carotid artery (ICA) is the most critical complication of endoscopic endonasal skull base surgery. Packing with a crushed muscle graft at the injury site has been an effective management technique to control bleeding without ICA sacrifice. Obtaining the muscle graft has typically required access to another surgical site, however. To address this concern, the authors investigated the application of an endonasally harvested longus capitis muscle patch for the management of ICA injury.

METHODS One colored silicone-injected anatomical specimen was dissected to replicate the surgical access to the nasopharynx and the stepwise dissection of the longus capitis muscle in the nasopharynx. Two representative cases were selected to illustrate the application of the longus capitis muscle patch and the relevance of clinical considerations.

RESULTS A suitable muscle graft from the longus capitis muscle could be easily and quickly harvested during endoscopic endonasal skull base surgery. In the illustrative cases, the longus capitis muscle patch was successfully used for secondary prevention of pseudoaneurysm formation following primary bleeding control on the site of ICA injury.

CONCLUSIONS Nasopharyngeal harvest of a longus capitis muscle graft is a safe and practical method to manage ICA injury during endoscopic endonasal surgery.

Quantitative assessment of secondary white matter injury in the visual pathway by pituitary adenomas: a multimodal study at 7-Tesla MRI

J Neurosurg 132:333–342, 2020

The objective of this study was to investigate microstructural damage caused by pituitary macroadenomas by performing probabilistic tractography of the optic tracts and radiations using 7-T diffusion-weighted MRI (DWI). These imaging findings were correlated with neuro-ophthalmological results to assess the utility of ultra–high-field MRI for objective evaluation of damage to the anterior and posterior visual pathways.
METHODS Probabilistic tractography employing 7-T DWI was used to reconstruct the optic tracts and radiations in 18 patients with adenomas and in 16 healthy volunteers. Optic chiasm compression was found in 66.7% of the patients and visual defects in 61.1%. Diffusion indices were calculated along the projections and correlated with tumor volumes and
results from neuro-ophthalmological examinations. Primary visual cortical thicknesses were also assessed.

RESULTS Fractional anisotropy was reduced by 21.9% in the optic tracts (p < 0.001) and 17.7% in the optic radiations (p< 0.001) in patients with adenomas. Patients showed an 8.5% increase in mean diffusivity of optic radiations compared with healthy controls (p < 0.001). Primary visual cortical thickness was reduced in adenoma patients. Diffusion indices of
the visual pathway showed significant correlations with neuro-ophthalmological examination findings.
CONCLUSIONS Imaging-based quantification of secondary neuronal damage from adenomas strongly correlated with neuro-ophthalmological findings. Diffusion characteristics enabled by ultra–high-field DWI may allow preoperative characterization of visual pathway damage in patients with chiasmatic compression and may inform prognosis for vision

The medial wall of the cavernous sinus. Part 2: Selective medial wall resection in 50 pituitary adenoma patients

J Neurosurg 131:131–140, 2019

Pituitary adenomas often invade the medial wall of the cavernous sinus (CS), but this structure is generally not surgically removed because of the risk of vascular and cranial nerve injury. The purpose of this study was to report the surgical outcomes in a large series of cases of invasive pituitary adenoma in which the medial wall of the CS was selectively removed following an anatomically based, stepwise surgical technique.

METHODS The authors’ institutional database was reviewed to identify cases of pituitary adenoma with isolated invasion of the medial wall, based on an intraoperative evaluation, in which patients underwent an endoscopic endonasal approach with selective resection of the medial wall of the CS. Cases with CS invasion beyond the medial wall were excluded. Patient complications, resection, and remission rates were assessed.

RESULTS Fifty patients were eligible for this study, 15 (30%) with nonfunctional adenomas and 35 (70%) with functional adenomas, including 16 growth hormone–, 10 prolactin-, and 9 adrenocorticotropic hormone (ACTH)–secreting tumors. The average tumor size was 2.3 cm for nonfunctional and 1.3 cm for functional adenomas. Radiographically, 11 cases (22%) were Knosp grade 1, 23 (46%) Knosp grade 2, and 16 (32%) Knosp grade 3. Complete tumor resection, based on intraoperative impression and postoperative MRI, was achieved in all cases. The mean follow-up was 30 months (range 4–64 months) for patients with functional adenomas and 16 months (range 4–30 months) for those with nonfunctional adenomas. At last follow-up, complete biochemical remission (using current criteria) without adjuvant treatment was seen in 34 cases (97%) of functional adenoma. No imaging recurrences were seen in patients who had nonfunctional adenomas. A total of 57 medial walls were removed in 50 patients. Medial wall invasion was histologically confirmed
in 93% of nonfunctional adenomas and 83% of functional adenomas. There were no deaths or internal carotid artery injuries, and the average blood loss was 378 ml. Four patients (8%) developed a new, transient cranial nerve palsy, and 2 of these patients required reoperation for blood clot evacuation and fat graft removal. There were no permanent cranial nerve palsies.

CONCLUSIONS The medial wall of the CS can be removed safely and effectively, with minimal morbidity and excellent resection and remission rates. Further follow-up is needed to determine the long-term results of this anatomically based technique, which should only be performed by very experienced endonasal skull base teams.

The medial wall of the cavernous sinus. Part 1: Surgical anatomy, ligaments, and surgical technique for its mobilization and/or resection

J Neurosurg 131:122–130, 2019

The medial wall of the cavernous sinus (CS) is often invaded by pituitary adenomas. Surgical mobilization and/or removal of the medial wall remains a challenge.

METHODS Endoscopic endonasal dissection was performed in 20 human cadaver heads. The configuration of the medial wall, its relationship to the internal carotid artery (ICA), and the ligamentous connections in between them were investigated in 40 CSs.

RESULTS The medial wall of the CS was confirmed to be an intact single layer of dura that is distinct from the capsule of the pituitary gland and the periosteal layer that forms the anterior wall of the CS. In 32.5% of hemispheres, the medial wall was indented by and/or well adhered to the cavernous ICA. The authors identified multiple ligamentous fibers that anchored the medial wall to other walls of the CS and/or to specific ICA segments. These parasellar ligaments were clas- sified into 4 groups: 1) caroticoclinoid ligament, spanning from the medial wall and the middle clinoid toward the clinoid ICA segment and anterior clinoid process; 2) superior parasellar ligament, connecting the medial wall to the horizontal cavernous ICA and/or lateral wall of the CS; 3) inferior parasellar ligament, bridging the medial wall to the anterior wall of the CS or anterior surface of the short vertical segment of the cavernous ICA; and 4) posterior parasellar ligament, which anchors the medial wall to the short vertical segment of the cavernous ICA and/or the posterior carotid sulcus. The caroticoclinoid ligament and inferior parasellar ligament were present in most CSs (97.7% and 95%, respectively), while the superior and posterior parasellar ligaments were identified in approximately half of the CSs (57.5% and 45%, respec- tively). The caroticoclinoid ligament was the strongest and largest ligament, and it was typically assembled as a group of ligaments with a fan-like arrangement. The inferior parasellar ligament was the first to be encountered after opening the anterior wall of the CS during an interdural transcavernous approach.

CONCLUSIONS The authors introduce a classification of the parasellar ligaments and their role in anchoring the medial wall of the CS. These ligaments should be identified and transected to safely mobilize the medial wall away from the cavernous ICA during a transcavernous approach and for safe and complete resection of adenomas that selectively invade the medial wall.

Complications associated with microscopic and endoscopic transsphenoidal pituitary surgery: experience of 1153 consecutive cases treated at a single tertiary care pituitary center

J Neurosurg 130:1576–1583, 2019

Pituitary adenomas (PAs) are benign neoplasms that are frequently encountered during workup for endocrinopathy, headache, or visual loss. Transsphenoidal surgery remains the first-line approach for PA resection. The authors retrospectively assessed complication rates associated with transsphenoidal PA resection from an institutional database.

METHODS A retrospective analysis of 1153 consecutive transsphenoidal pituitary adenoma resections performed at the Keck Hospital of USC between November 1992 and March 2017 was conducted. Microscopic transsphenoidal resection was performed in 85.3% of cases, and endoscopic transsphenoidal resection was performed in 14.7%. Analysis of perioperative complications and patient and tumor risk factors was conducted.

RESULTS The overall median hospital stay was 3 days. There was 1 perioperative death (0.1%). Surgical complications included postoperative cerebrospinal fluid leak (2.6%), epistaxis (1.1%), postoperative hematoma (1.1%), meningitis (1.0%), cranial nerve paresis (0.8%), hydrocephalus (0.8%), vision loss (0.6%), stroke (0.3%), abdominal hematoma or infection (0.2%), carotid artery injury (0.1%), and vegetative state (0.2%). Perioperative medical complications included bacteremia/sepsis (0.5%), pneumonia (0.3%), myocardial infarction (0.3%), and deep venous thrombosis/pulmonary embolism (0.1%). Endocrine complications were the most frequent, including transient diabetes insipidus (4.3%), symptomatic hyponatremia (4.2%), new hypopituitarism (any axis) (3.6%), permanent diabetes insipidus (0.3%), and adrenal insufficiency (0.2%). There were no significant differences between microscopic and endoscopic approaches with regard to surgical complications (6.4% vs 8.8%, p = 0.247) or endocrine complications (11.4 vs 11.8%, p = 0.888). Risk factors for surgical complications included prior transsphenoidal surgery (11.4% vs 6.8%, p = 0.025), preoperative vision loss (10.3% vs 6.8%, p = 0.002), and presence of PA invasion on MRI (8.5% vs 4.4%, p = 0.007).

CONCLUSIONS In this single tertiary center study assessing complications associated with transsphenoidal PA resection, the rate of death or major disability was 0.26%. Risk factors for complications included prior surgical treatment and PA invasion. No differences in complication rates between endoscopic and microscopic surgery were observed. When performed at experienced pituitary centers, transsphenoidal surgery for PAs may be performed with a high degree of safety.


Surgical intervention for pituitary apoplexy

J Neurosurg 129:417–424, 2018

Pituitary apoplexy is a clinical syndrome consisting of neurological and endocrine abnormalities secondary to hemorrhage or ischemia of an underlying pituitary adenoma. The authors investigated whether there was a significant difference in neurological, endocrine, and nonneuroendocrine outcomes for patients with pituitary apoplexy, based on the time between symptom onset and surgical intervention.

METHODS The authors retrospectively analyzed the medical records of 32 patients who had presented to their institutionith acute pituitary apoplexy and subsequently undergone endonasal transsphenoidal resection in the period from 2003 to 2014. All patients had undergone preoperative MRI demonstrating evidence of apoplexy in the form of intratumoral hemorrhage, ischemia, and necrosis. Neurological deficits, partial or complete endocrinopathy, and nonneuroendocrine abnormalities were analyzed both pre- and postoperatively.

RESULTS Preoperatively, neurological deficits including visual loss and cranial nerve palsies were found in 31 (97%) of the 32 patients, endocrinopathy in the form of partial or panhypopituitarism was seen in 28 patients (88%), and nonneuroendocrine signs and symptoms were seen in 32 patients (100%). Thirteen patients (41%) underwent surgery within 72 hours of symptom onset (“early”), whereas 19 patients (59%) underwent surgery more than 72 hours from symptom onset (“delayed”). Early versus delayed resection did not appear to significantly improve visual deficits, total visual loss, resolution of oculomotor palsy, recovery from hypopituitarism, or nonneuroendocrine signs and symptoms such as headache and encephalopathy. Overall, visual improvement was seen in 77% of patients, complete restoration of normal vision in 38% of patients, and resolution of preoperative oculomotor palsies in 81% of patients. Only 6 (21%) of 28 patients showed evidence of partial hormone recovery following preoperative hypopituitarism. An absence of benefit for early surgery held true even when considering time to surgery from symptom onset as a continuous variable.
CONCLUSIONS Neurological deficits such as visual loss and cranial neuropathies show moderate improvement following surgical decompression, as does preoperative hypopituitarism. The timing of surgical intervention relative to the onset of symptoms does not appear to significantly affect the resolution of neurological or endocrinological deficits.

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

J Neurosurg 128:1066–1071, 2018

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.

Endonasal endoscopic pituitary surgery in the elderly

J Neurosurg 128:429–436, 2018

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.

METHODS 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.

RESULTS 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.

CONCLUSIONS 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.

Endoscopic endonasal versus transcranial approach to tuberculum sellae and planum sphenoidale meningiomas

J Neurosurg 128:40–48, 2018

Planum sphenoidale (PS) and tuberculum sellae (TS) meningiomas cause visual symptoms due to compression of the optic chiasm. The treatment of choice is surgical removal with the goal of improving vision and achieving complete tumor removal. Two options exist to remove these tumors: the transcranial approach (TCA) and the endonasal endoscopic approach (EEA). Significant controversy exists regarding which approach provides the best results and whether there is a subset of patients for whom an EEA may be more suitable. Comparisons using a similar cohort of patients, namely, those suitable for gross-total resection with EEA, are lacking from the literature.

METHODS The authors reviewed all cases of PS and TS meningiomas that were surgically removed at Weill Cornell Medical College between 2000 and 2015 (TCA) and 2008 and 2015 (EEA). All cases were shown to a panel of 3 neurosurgeons to find only those tumors that could be removed equally well either through an EEA or TCA to standardize both groups. Volumetric measurements of preoperative and postoperative tumor size, FLAIR images, and apparent diffusion coefficient maps were assessed by 2 independent reviewers and compared to assess extent of resection and trauma to the surrounding brain. Visual outcome and complications were also compared.

RESULTS Thirty-two patients were identified who underwent either EEA (n = 17) or TCA (n = 15). The preoperative tumor size was comparable (mean 5.58 ± 3.42 vs 5.04 ± 3.38 cm3 [± SD], p = 0.661). The average extent of resection achieved was not significantly different between the 2 groups (98.80% ± 3.32% vs 95.13% ± 11.69%, p = 0.206). Postoperatively, the TCA group demonstrated a significant increase in the FLAIR/edema signal compared with EEA patients (4.15 ± 7.10 vs -0.69 ± 2.73 cm3, p = 0.014). In addition, the postoperative diffusion-weighted imaging signal of cytotoxic ischemic damage was significantly higher in the TCA group than in the EEA group (1.88 ± 1.96 vs 0.40 ± 0.55 cm3, p = 0.008). Overall, significantly more EEA patients experienced improved or stable visual outcomes compared with TCA patients (93% vs 56%, p = 0.049). Visual deterioration was greater after TCA than EEA (44% vs 0%, p = 0.012). While more patients experienced postoperative seizures after TCA than after EEA (27% vs 0%, p = 0.038), there was a trend toward more CSF leakage and anosmia after EEA than after TCA (11.8% vs 0%, p = 0.486 and 11.8% vs 0%, p = 0.118, respectively).

CONCLUSIONS In this small single-institution study of similarly sized and located PS and TS meningiomas, EEA provided equivalent rates of resection with better visual results, less trauma to the brain, and fewer seizures. These preliminary results merit further investigation in a larger multiinstitutional study and may support EEA resection by experienced surgeons in a subset of carefully selected PS and TS meningiomas.

A checklist for endonasal transsphenoidal anterior skull base surgery

Intraoperative MRI for transsphenoidal pituitary surgery

J Neurosurg 124:1634–1639, 2016

Approximately 250 million surgical procedures are performed annually worldwide, and data suggest that major complications occur in 3%–17% of them. Many of these complications can be classified as avoidable, and previous studies have demonstrated that preoperative checklists improve operating room teamwork and decrease complication rates. Although the authors’ institution has instituted a general preoperative “time-out” designed to streamline communication, flatten vertical authority gradients, and decrease procedural errors, there is no specific checklist for transnasal transsphenoidal anterior skull base surgery, with or without endoscopy. Such minimally invasive cranial surgery uses a completely different conceptual approach, set-up, instrumentation, and operative procedure. Therefore, it can be associated with different types of complications as compared with open cranial surgery. The authors hypothesized that a detailed, procedure-specific, preoperative checklist would be useful to reduce errors, improve outcomes, decrease delays, and maximize both teambuilding and operational efficiency. Thus, the object of this study was to develop such a checklist for endonasal transsphenoidal anterior skull base surgery.

Methods An expert panel was convened that consisted of all members of the typical surgical team for transsphenoidal endoscopic cases: neurosurgeons, anesthesiologists, circulating nurses, scrub technicians, surgical operations managers, and technical assistants. Beginning with a general checklist, procedure-specific items were added and categorized into 4 pauses: Anesthesia Pause, Surgical Pause, Equipment Pause, and Closure Pause.

Results The final endonasal transsphenoidal anterior skull base surgery checklist is composed of the following 4 pauses. The Anesthesia Pause consists of patient identification, diagnosis, pertinent laboratory studies, medications, surgical preparation, patient positioning, intravenous/arterial access, fluid management, monitoring, and other special considerations (e.g., Valsalva, jugular compression, lumbar drain, and so on). The Surgical Pause is composed of personnel introductions, planned procedural elements, estimation of duration of surgery, anticipated blood loss and fluid management, imaging, specimen collection, and questions of a surgical nature. The Equipment Pause assures proper function and availability of the microscope, endoscope, cameras and recorders, guidance systems, special instruments, ultrasonic microdoppler, microdebrider, drills, and other adjunctive supplies (e.g., Avitene, cotton balls, nasal packs, and so on). The Closure Pause is dedicated to issues of immediate postoperative patient disposition, orders, and management.

Conclusions Surgical complications are a considerable cause of death and disability worldwide. Checklists have been shown to be an effective tool for reducing preventable errors surrounding surgery and decreasing associated complications. Although general checklists are already in place in most institutions, a specific checklist for endonasal transsphenoidal anterior skull base surgery was developed to help safeguard patients, improve outcomes, and enhance teambuilding.

Comparison of outcomes between a less experienced surgeon using a fully endoscopic technique and a very experienced surgeon using a microscopic transsphenoidal technique for pituitary adenoma

Intraoperative high-field MRI for transsphenoidal reoperations of nonfunctioning pituitary adenoma

J Neurosurg 124:596–604, 2016

The comparative efficacy of microscopic and fully endoscopic transsphenoidal surgery for pituitary adenomas has not been well studied despite the adoption of fully endoscopic surgery by many pituitary centers. The influence of surgeon experience has also not been examined in this setting. The authors therefore compared the extent of tumor resection (EOR) and the endocrine outcomes of 1 very experienced surgeon performing a microscopic transsphenoidal surgery technique with those of a less experienced surgeon using a fully endoscopic transsphenoidal surgery technique for resection of nonfunctioning pituitary adenomas in a concurrent series of patients.

Methods Post hoc analysis was conducted of a cohort of adult patients prospectively enrolled in a pituitary adenoma quality-of-life study between October 2011 and June 2014. Patients were followed up for 6 months after surgery. Patients were treated either by a less experienced surgeon (100 independent cases) who practices fully endoscopic surgery exclusively or by a very experienced surgeon (1800 independent cases) who practices microscopic surgery exclusively. Patient demographic characteristics, tumor characteristics, hypopituitarism, complications, and length of hospital stay were analyzed. Tumor volumes and EOR were determined by formal volumetric analysis involving manual segmentation of MR images performed before surgery and within 6 months after surgery. Logistic regression analysis was used to determine predictors of EOR.

Results Fifty-five patients underwent fully endoscopic transsphenoidal surgery, and 80 patients underwent fully microscopic transsphenoidal surgery. The baseline characteristics of the 2 treatment groups were well matched. EOR was similar between the endoscopic and microscopic groups, respectively, as estimated by gross-total resection rate (78.2% vs 81.3%, p = 0.67), percentage of tumor resected (99.2% vs 98.7%, p = 0.42), and volume of residual tumor (0.12 cm3 vs 0.20 cm3, p = 0.41). Multivariate modeling suggested that preoperative tumor volume was the most important predictor of EOR (p = 0.001). No difference was found in the development of anterior gland dysfunction (p > 0.14), but there was a higher incidence of permanent posterior gland dysfunction in the microscopic group (p = 0.04). Combined rates of major complications and unplanned readmissions were lower in the endoscopic group (p = 0.02), but individual complications were not significantly different.

Conclusions A less experienced surgeon using a fully endoscopic technique was able to achieve outcomes similar to those of a very experienced surgeon using a microscopic technique in a cohort of patients with nonfunctioning tumors smaller than 60 cm3. The study raises the provocative notion that certain advantages afforded by the fully endoscopic technique may impact the learning curve in pituitary surgery for nonfunctioning adenomas.

A basic model for training of microscopic and endoscopic transsphenoidal pituitary surgery: the Egghead

A basic model for training of microscopic and endoscopic transsphenoidal pituitary surgery- the Egghead

Acta Neurochir (2015) 157:1771–1777

Transsphenoidal endoscopic surgery has gained popularity in the last 2 decades and is becoming a standard technique for resection of pituitary adenomas. In contrast to their ENT colleagues, neurosurgical residents have practically no endoscopic experience when they reach the training stage for transsphenoidal procedures.

We have developed an affordable method for repetitive training in endoscopic (and microscopic) work in a narrow channel, allowing training of the basic movements needed for resection of pituitary adenoma.

Methods In collaboration with colleagues in the ENT Department, Cantonal Hospital St. Gall, and the Technical University of Zurich, a three-dimensional model of the nasal cavity was developed and patented. The Egghead model consists of a 3D synthetic reconstruction of the head nasal cavity and sphenoid sinus. A boiled egg represents the sella. For validation, 17 neurosurgical residents from the Department of Neurosurgery, University Hospital of Basel, and Department of Neurosurgery, Cantonal Hospital of St. Gall, St. Gall, Switzerland, and two experts performed a standardized procedure mimicking a transsphenoidal pituitary procedure by dissecting a corridor to the egg yolk and resecting it, respecting the surrounding egg white. This procedure was performed under both microscopic and video-endoscopic visualization. A score for the precision and speed of the surgical performance was developed and used.

Results The model allows repetitive training of the resection of the egg yolk under sparing of the egg white after careful opening of the shell. The validation data showed a steeper learning curve using the endoscopic technique than performing the same task using the microscope. After three repetitions, the quality of resection was better with the endoscopic technique.

Conclusions Our model, the Egghead, is affordable, offers tactile feedback and allows infinite repetitions in basic training for pituitary surgery. It can be used for training of advanced neurosurgical residents, who thus far have very few possibilities of acquiring endoscopic experience.

Management and outcomes of pituitary apoplexy

pituitary apoplexy

J Neurosurg 122:1450–1457, 2015

This study was undertaken to analyze the predisposing factors, clinical presentation, therapeutic management, and clinical recovery in patients with pituitary apoplexy, with an emphasis on the long-term visual, endocrine, and functional outcomes.

Methods The authors performed a retrospective analysis of consecutive cases involving patients treated at Mayo Clinic between 1992 and 2013. Patients were included in the study only if they had 1) abrupt onset of severe headache or visual disturbance in the presence of a pituitary adenoma and 2) radiological or surgical confirmation of a pituitary mass. The primary endpoints of analysis were the visual (ocular motility, visual fields, and visual acuity), endocrine, and functional outcomes (using the modified Rankin Scale).

Results Eighty-seven patients were identified (57 males and 30 females, mean age 50.9 years, range 15–91 years). Twenty-two patients (25.3%) had a known pituitary adenoma. Hypertension was the most common associated factor (39%). Headache was the most frequent presenting symptom (89.7%), followed by visual abnormalities (47.1%). Cranial nerve palsies were present in 39% and visual field defects in 34.1%. MRI detected hemorrhage in 89% patients, as compared with 42% detected by CT scan. Sixty-one patients (70.1%) underwent surgery during acute hospitalization (median time from apoplexy 5 days, IQR 3–10 days), 8 (9.2%) had delayed surgery, and 18 (20.7%) were treated conservatively. Histopathological examination revealed adenoma with pure necrosis in 18 (30%), pure hemorrhage in 4 (6.7%), and both in 6 (10%) patients. Four patients died during hospitalization. The average duration of follow-up was 44.2 ± 43.8 months. All survivors were independent and had complete resolution or substantial improvement in eye movements and visual fields at the last follow-up. Many patients needed long-term hormonal replacement with levothyroxine (62.7%) and cortisol (60%). Daily desmopressin was needed in 23% of all surgical patients at 3 months (versus none of the medically treated) and this requirement decreased slightly over time. Regrowth of pituitary adenoma was seen in 7 patients (8.6%). There were no statistically significant differences in any of the outcome measures across the treatment groups.

Conclusions The outcome of most patients with pituitary apoplexy is excellent. Selected patients can be managed conservatively, and patients with severe neuro-ophthalmological deficits treated with early surgery can achieve an excellent recovery.

Endoscopic endonasal resection of skull base chondrosarcomas

Endoscopic endonasal resection of skull base chondrosarcomas- technique and early results

J Neurosurg 122:735–742, 2015

The authors of this study sought to report the technique and early clinical outcomes of a purely endonasal endoscopic approach for resection of petroclival chondrosarcomas.

Methods Between 2010 and 2014, 8 patients (4 men and 4 women) underwent endonasal endoscopic operations to resect petroclival chondrosarcomas at 2 institutions. The patients’ mean age was 44.8 years (range 30–64 years). One of the patients had previously undergone radiation therapy and another a staged craniotomy. Using volumetric software, an independent neuroradiologist assessed the extent of the resections on MRI scans taken immediately after surgery and at the 3-month follow-up. Immediate complications and control of symptoms were also recorded. In addition, the authors reviewed the current literature on surgical treatment of chondrosarcoma.

Results The mean preoperative tumor diameter and volume were 3.4 cm and 9.8 cm3, respectively. Six patients presented with cranial neuropathies. Endonasal endoscopic surgery achieved > 95% resection in 5 of the 8 patients and < 95% resection in the remaining 3 patients. One of the 6 neuropathies resolved, and the remaining 5 partially improved. One instance of postoperative CSF leakage required a reoperation for repair; no other complications associated with these operations were observed. All of the patients underwent adjuvant radiotherapy.

Conclusions According to the authors’ experience, the endoscopic endonasal route is a safe and effective approach for the resection of appropriately selected petroclival chondrosarcomas.

Invasion of the cavernous sinus space in pituitary adenomas: endoscopic verification and its correlation with an MRI-based classification

Invasion of the cavernous sinus space in pituitary adenomas- endoscopic verification and its correlation with an MRI-based classification

J Neurosurg 122:803–811, 2015

An important prognostic factor for the surgical outcome and recurrence of a pituitary adenoma is its invasiveness into parasellar tissue, particularly into the space of the cavernous sinus (CS). The aims of this study were to reevaluate the existing parasellar classifications using an endoscopic technique and to evaluate the clinical and radiological outcomes associated with each grade.

Methods The authors investigated 137 pituitary macroadenomas classified radiologically at least on one side as Grade 1 or higher (parasellar extension) and correlated the surgical findings using an endoscopic technique, with special reference to the invasiveness of the tumor into the CS. In each case, postoperative MRI was performed to evaluate the gross-total resection (GTR) rate and the rate of endocrinological remission (ER) in functioning adenomas.

Results The authors found a 16% rate of CS invasion during surgery for these macroadenomas. Adenomas radiologically classified as Grade 1 were found to be invasive in 1.5%, and the GTR/ER rate was 83%/88%. For Grade 2 adenomas, the rate of invasion was 9.9%, and the GTR/ER rate was 71%/60%. For Grade 3 adenomas, the rate of invasion was 37.9%, and the GTR/ER rate was 75%/33%. When the superior compartment of the CS (Grade 3A) was involved, the authors found a rate of invasion that was lower (p < 0.001) than that when the inferior compartment was involved (Grade 3B). The rate of invasion in Grade 3A adenomas was 26.5% with a GTR/ER rate of 85%/67%, whereas for Grade 3B adenomas, the rate of surgically observed invasion was 70.6% with a GTR/ER rate of 64%/0%. All of the Grade 4 adenomas were invasive, and the GTR/ER rate was 0%. A comparison of microscopic and endoscopic techniques revealed no difference in adenomas with Grade 1 or 4 parasellar extension. In Grade 2 adenomas, however, the CS was found by the endoscopic technique to be invaded in 9.9% and by microscopic evaluation to be invaded in 88% (p < 0.001); in Grade 3 adenomas, the difference was 37.9% versus 86%, respectively (p = 0.002). Grade 4 adenomas had a statistically significant lower rate of GTR than those of all the other grades. In case of ER only, Grade 1 adenomas had a statistically significant higher rate of remission than did Grade 3B and Grade 4 adenomas.

Conclusions The proposed classification proved that with increasing grades, the likelihood of surgically observed invasion rises and the chance of GTR and ER decreases. The direct endoscopic view confirmed the low rate of invasion of Grade 1 adenomas but showed significantly lower rates of invasion in Grade 2 and 3 adenomas than those previously found using the microscopic technique. In cases in which the intracavernous internal carotid artery was encased (Grade 4), all the adenomas were invasive and the GTR/ER rate was 0%/0%. The authors suggest the addition of Grades 3A and 3B to distinguish the strikingly different outcomes of adenomas invading the superior CS compartments and those invading the inferior CS compartments.

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