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.

Ocular Optical Coherence Tomography in the Evaluation of Sellar and Parasellar Masses

Neurosurgery 92:42–67, 2023

Compression of the anterior visual pathways by sellar and parasellar masses can produce irreversible and devastating visual loss.

Optical coherence tomography (OCT) is a noninvasive high-resolution ocular imaging modality routinely used in ophthalmology clinics for qualitative and quantitative analysis of optic nerve and retinal structures, including the retinal ganglion cells.

By demonstrating structural loss of the retinal ganglion cells whose axons form the optic nerve before decussating in the optic chiasm, OCT imaging of the optic nerve and retina provides an excellent tool for detection and monitoring of compressive optic neuropathies and chiasmopathies due to sellar and parasellar masses.

Recent studies have highlighted the role of OCT imaging in the diagnosis, follow-up, and prognostication of the visual outcomes in patients with chiasmal compression. OCT parameters of optic nerve and macular scans such as peripapillary retinal nerve fiber layer thickness and macular ganglion cell thickness are correlated with the degree of visual loss; additionally, OCT can detect clinically significant optic nerve and chiasmal compression before visual field loss is revealed on automated perimetry. Preoperative values of OCT optic nerve and macular parameters represent a prognostic tool for postoperative visual outcome.

This review provides a qualitative analysis of the current applications of OCT imaging of the retina and optic nerve in patients with anterior visual pathway compression from sellar and parasellar masses. We also review the role of new technologies such as OCT-angiography, which could improve the prognostic ability of OCT to predict postoperative visual function.

Expanded endoscopic endonasal approach for the resection of midline craniopharyngiomas with hypothalamic involvement

Acta Neurochirurgica (2022) 164:3291–3296

With relevant surrounding neurological structures and potential involvement of the hypothalamus, the surgical management of craniopharyngiomas is complex. Compared to the transcranial approach, the expanded endoscopic endonasal approach provides direct access to the supradiaphragmatic and retrochiasmatic areas without crossing nerves and arteries.

Method Based on our substantial experience of 68 patients operated on between 2008 and 2022 by endoscopic surgery, our strategy has evolved such that all of our midline infundibular craniopharyngiomas with hypothalamic involvement are currently treated with an expanded endonasal route, except for tumours isolated to the third ventricle. Vascularized mucosal nasoseptal flaps are required for closure. Fine details of the related anatomy and surgical technique are described.

Conclusion Expanded endoscopic endonasal approach is a safe and effective route for resection of midline suprasellar craniopharyngiomas with hypothalamic involvement in centres of expertise.

Resection of the Cavernous Sinus Medial Wall Improves Remission Rate in Functioning Pituitary Tumors: Retrospective Analysis of 248 Consecutive Cases

Neurosurgery 91:775–781, 2022

The purpose of transsphenoidal surgery (TSS) for a functioning pituitary tumor (FPT) is to achieve endocrinological remission. The biggest challenge is aggressive tumor resection invading the cavernous sinus (CS).

OBJECTIVE: To evaluate the effects of the medial wall of CS (MWCS) resection during FPT surgery.

METHODS: Consecutive FPTs were reviewed for CS invasion (CSI) between April 2018 and December 2021. We operated on more than 250 FPTs, including 134 somatotroph tumors, 70 corticotroph tumors, 35 lactotroph tumors, and 9 thyrotroph tumors.

RESULTS: The patients were classified into 3 groups based on the relationship between the tumor and the CS: group A (no clear wall invasion), in which MWCS was not removed because of no tumorous direct contact with MWCS (N = 92) and group B (possible wall invasion), where MWCS was removed because we were not confident of MWCS invasion (N = 102). Among these 102 patients, histological tumor invasion was confirmed in 45 of 79 patients (57%) for whom histology findings were available. Tumors invading the CS clearly during surgery were classified into the “clear CS invasion” (group C: N = 55) group. The overall complete remission rate in group B was 94%, which was as high as that in group A (87%). Moreover, we clarified that microscopic invasion of MWCS could not always be predicted from Knosp grading.

CONCLUSION: MWCS invasion occurred in 57% of cases confirmed histologically where it was unclear during surgery, and its resection can improve the overall complete remission rate in FPT cases.

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.

Experience and modification of skull base reconstruction results in lower complications rates

Objectives To investigate the efficacy of nasal septum bone flap combined with vascularized pedicle nasoseptal flap (VPNSF) in the treatment of high-flow cerebrospinal fluid (CSF) leakage in the endonasal endoscopic skull base surgery.

Methods A total of 156 patients in group A used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater- fascia lata-VP-NSF, and were treated with drainage of the lumbar cistern after surgery, in addition, a total of 94 patients in group B used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater-nasal septal bone flap-VP-NSF, and no lumbar cistern drainage was performed after surgery. Analyzed and compared the differences of postoperative cerebrospinal fluid rhinorrhea, intracranial infection, re-repair, average bed rest time, pulmonary infection and deep venous thrombosis of lower extremities were analyzed and compared in the two groups.

Results In group A, 11 cases of cerebrospinal fluid rhinorrhea occurred after operation. In addition, 15 cases developed intracranial infection. During this period, there were 20 cases of pulmonary infection and 3 cases of deep venous thrombosis of lower extremities. In group B, there were 1 case of cerebrospinal fluid rhinorrhea (P < 0.05), 2 cases of intracranial infection (P < 0.05), 2 cases of pulmonary infection (P < 0.05), and 0 case of deep venous thrombosis of lower extremities (P > 0.05).

Conclusion Nasal septum bone flap combined with VP-NSF is effective in the treatment of high-flow CSF leaks in the endonasal endoscopic skull base surgery, which can avoid postoperative lumbar cistern drainage and is worth popularizing.

Double pedicled nasoseptal flap for skull base repair after endoscopic expanded endonasal approach

Acta Neurochirurgica (2022) 164:1111–1114

Expanded endonasal approach offers a spectacular corridor for skull base tumour resection but requires reliable multilayer reconstruction techniques with a vascularized nasoseptal flap.

Method On the basis on our substantial experience of 136 patients operated on between January 2008 and January 2020, the double pedicled nasoseptal flap technique was developed for skull base repair. The technique is finely detailed. The nasal floor mucosa was preserved. CSF leakage occurred in 4% of patients.

Conclusion Double pedicled nasoseptal flap is a reproducible and efficient technique for skull base reconstruction after expanded endonasal approach and is associated with limited rhinological complications.

Quality of Life After Endoscopic Surgical Management of Pituitary Adenomas

Neurosurgery 90:81–91, 2022

Patient-reported quality of life (QOL) is a vital metric for surgical success.
OBJECTIVE: To assess the effect of surgery on QOL in the largest prospectively collected, longitudinal cohort of surgically managed pituitary adenomas.
METHODS: A consecutive surgical adenoma cohort (n=304) between late 2016 and mid- 2020 underwent a scheduled overall (Anterior Skull Base Questionnaire-35) and sinonasal- specific (Sinonasal Outcome Test-22) QOL assessment. Scores were stratified by adenoma subtype and analyzed for clinical predictors of QOL changes.
RESULTS: The average age was 53.8 ± 16 yr, and 53% of participants were female. 60.9% of adenomas were nonfunctioning while adrenocorticotropic hormone adenomas (16.4%), growth hormone adenomas (14.1%), and prolactinomas (5.9%) were the most prevalent secreting adenomas. Baseline overall QOL differed between tumor types (P = .006), with adrenocorticotropic hormone adenomas worse than growth hormone adenomas (P = .03) and nonfunctioning pituitary adenomas (NFPA) (P < .001). Sinonasal QOL worsened in the 3 wk after surgery but returned to baseline by 6 wk and beyond. Overall QOL worsened at 3 wk after surgery (P < .001) but significantly improved from baseline by 3 mo (P = .009) and beyond (P < .001). Emotional functioning improved soon after surgery, followed by performance and pain, and then, by 6 mo, physical function and vitality. Predictors of improved QOL were sellar/suprasellar lesions (P = .01), prolactinomas (P = .003), and NFPA (P = .04). Conversely, new postoperative hypopituitarism (P = .04) and larger adenoma volume (P = .04) predicted QOL worsening.
CONCLUSION: QOL is worsened after surgery at early time points. Prolactinomas and NFPA enjoy significant QOL improvements from surgery as early as 3 mo postoperatively. Other functional tumors may experience early benefits in younger patients without hypopituitarism and when isolated to the sellar/suprasellar region. These findings provide valuable information for counseling patients and setting expectations for surgery.

Aggressive pituitary neuroendocrine tumors: current practices, controversies, and perspectives, on behalf of the EANS skull base section

Acta Neurochirurgica (2021) 163:3131–3142

Aggressive pituitary neuroendocrine tumors (APT) account for 10% of pituitary tumors. Their management is a rapidly evolving field of clinical research and has led pituitary teams to shift toward a neuro-oncological-like approach.

The new terminology “Pituitary neuroendocrine tumors” (PitNet) that was recently proposed to replace “pituitary adenomas” reflects this change of paradigm. In this narrative review, we aim to provide a state of the art of actual knowledge, controversies, and recommendations in the management of APT.

We propose an overview of current prognostic markers, including the recent five-tiered clinicopathological classification. We further establish and discuss the following recommendations from a neurosurgical perspective: (i) surgery and multi-staged surgeries (without or with parasellar resection in symptomatic patients) should be discussed at each stage of the disease, because it may potentialize adjuvant medical therapies; (ii) temozolomide is effective in most patients, although 30% of patients are non-responders and the optimal timeline to initiate and interrupt this treatment remains questionable; (iii) some patients with selected clinicopathological profiles may benefit from an earlier local radiotherapy and/or chemotherapy; (iv) novel therapies such as VEGF-targeted therapies and anti-CTLA-4/anti-PD1 immunotherapies are promising and should be discussed as 2nd or 3rd line of treatment.

Finally, whether neurosurgeons have to operate on “pituitary adenomas” or “PitNets,” their role and expertise remain crucial at each stage of the disease, prompting our community to deal with evolving concepts and therapeutic resources.

The Shape grading system: a classification for growth patterns of pituitary adenomas

Acta Neurochirurgica (2021) 163:3181–3189

Long-term tumor control of pituitary adenomas may be achieved by gross total resection (GTR). Factors, which influence the extent of resection, are invasiveness, tumor size, and possibly tumor shape. Nevertheless, the latter factor has not been assessed so far and there is no classification for the different shapes. The aim of this study was to evaluate the impact of different tumor shapes on GTR rates and outcome according to our proposed “Shape grading system.”

Methods In this retrospective single center study, the radiological outcome of nonfunctioning pituitary adenomas was assessed with respect to the following previously defined growth patterns: spherical (Shape I), oval (Shape II), dumbbell (Shape III), mushroom (Shape IV), and polylobulated (Shape V).

Results A total of 191 patients were included (Shape I, n = 28 (15%); Shape II, n = 91 (48%); Shape III, n = 37 (19%); Shape IV, n = 12 (6%); Shape V, n = 23 (12%)). GTR was achieved in 101 patients (53%) with decreasing likelihood of GTR in higher shape grades (Shape I, n = 23 (82%); Shape II, n = 67 (74%); Shape III, n = 9 (24%); Shape IV, n = 2 (17%); Shape V, n = 0 (0%)). This correlated with larger tumor remnants, a higher risk of tumor recurrence/regrowth and therefore necessity of re-surgery and/or radiotherapy/radiosurgery.

Conclusion The “Shape grading system” may be used as a predictor of the outcome in nonfunctioning pituitary adenomas. The higher the “Shape grade,” the higher the likelihood for lower GTR rates, larger tumor remnants, and need for further therapies.

Surgical anatomy and nuances of the extended endoscopic endonasal transtuberculum sellae approach: pearls and pitfalls for complications avoidance

Acta Neurochirurgica (2021) 163:399–405

Using the expanded endoscopic transtuberculum approach (EETA), the nuances of this technique have rendered a safe, direct, and feasible ventral corridor for the treatment of extending suprasellar pathologies. This study illustrates surgical landmarks and strategies of paramount importance for complications avoidance.

Methods This study presents the surgical anatomy and nuances of EETA, which can be used to remove large pituitary adenomas with suprasellar extension. Special references to cadaveric dissections highlight anatomical landmarks and surgical key points for complications avoidance.

Conclusion The EETA represents a versatile route for the treatment of sellar/suprasellar pathologies. Although, sizeable extrasellar pituitary tumors still pose a threat due to displacement/encasement of surrounding structures, necessitating accurate knowledge of correlative operative anatomy with traditional landmarks. Complete resection of extrasellar components is essential to avoid postoperative apoplexy.

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.

Diabetes Insipidus After Endoscopic Transsphenoidal Surgery

Neurosurgery 2020 DOI:10.1093/neuros/nyaa148

Diabetes insipidus (DI) is a recognized transient or permanent complication following transsphenoidal surgery (TSS) for pituitary tumors.

OBJECTIVE: To describe significant experience with the incidence of DI after TSS, identifying predictive characteristics and describing our diagnosis and management of postoperative DI.

METHODS: A retrospective analysis was performed of 700 patients who underwent endoscopic TSS for resection of pituitary adenoma (PA), Rathke cleft cyst (RCC), or craniopharyngioma. Inclusion criteria included at least 1 wk of follow-up for diagnosis of postoperative DI. Permanent DI was defined as DI symptoms and/or need for desmopressinmore than 1 yr postoperatively. All patients with at least 1 yr of follow-up (n=345) were included in analyses of permanent DI. Multivariable logistic regression models were constructed to identify predictors of transient or permanent postoperative DI.

RESULTS: The overall rate of any postoperative DI was 14.7% (103/700). Permanent DI developed in 4.6% (16/345). The median follow-up was 10.7mo (range: 0.2-136.6). Compared to patients with PA, patients with RCC (odds ratio [OR] = 2.2, 95% CI: 1.2-3.9; P = .009) and craniopharyngioma (OR = 7.0, 95% CI: 2.9-16.9; P ≤ .001) were more likely to develop postoperative DI. Furthermore, patients with RCC (OR = 6.1, 95% CI: 1.8-20.6; P = .004) or craniopharyngioma (OR = 18.8, 95% CI: 4.9-72.6; P ≤ .001) were more likely to develop permanent DI compared to those with PA.

CONCLUSION: Although transient DI is a relatively common complication of endoscopic and microscopic TSS, permanent DI is much less frequent. The underlying pathology is an important predictor of both occurrence and permanency of postoperative DI.



Endoscopic Transnasal Trans-Sphenoidal Approach for Pituitary Adenomas: A Comparison to the Microscopic Approach Cohort by Propensity Score Analysis

Neurosurgery DOI:10.1093/neuros/nyz201

Despite some evidence for the adoption of endoscopic transnasal transsphenoidal surgery (ETSS) for pituitary adenomas, the advantages of this technique over the traditional approach have not been robustly confirmed.

OBJECTIVE: To compare ETSS with the microscopic sublabial trans-septal transsphenoidal surgery (MTSS) for pituitary adenomas.

METHODS: We retrospectively reviewed 2 cohorts of ETSS and MTSS performed at our institution from 1995 to 2017. Patient characteristics, surgical data, and outcomes were recorded prospectively. We performed a univariate and multivariable analysis to determine the best surgical approach. To improve the quality of the results, we matched the distribution of patient characteristics between groups by propensity score (PS) method.

RESULTS: A total of 187 procedures (90 MTSS, 97 ETSS) were reviewed. We found better results in the ETSS group in terms of gross total resection (P = .002) and hormone-excess secretion control (P=.014). There was also a lower incidence of cerebrospinal fluid leakage (P = .039), transitory diabetes insipidus (P = .028), and postoperative hypopituitarism (P = .045), as well as a shorter hospital length of stay (P < .001). After PS matching, we confirmed by multivariable logistic regression analysis an increased odds ratio of gross total resection for the ETSS (3.910; 95% CI 1.720-8.889; P= .001).

CONCLUSION: By PS method, our results suggest that the ETSS provides advantages over the traditional MTSS approach for tumor resection. Better control of secreting tumors and a lower rate of most complications also support the selection of the ETSS approach for the treatment of pituitary adenomas.

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

Withholding Perioperative Steroids in Patients Undergoing Transsphenoidal Resection for Pituitary Disease: Randomized Prospective Clinical Trial to Assess Safety

Neurosurgery, Volume 85, Issue 2, August 2019, Pages E226–E232

Perioperative steroid protocols for patients undergoing transsphenoidal surgery (TSS) for pituitary pathology vary by institution.

OBJECTIVE: To assess the safety of withholding glucocorticoids in patients undergoing TSS.

METHODS: Patients with an intact hypothalamic-pituitary-adrenal (HPA) axis undergoing TSS for a pituitary tumor at the same academic institution between 2012 and 2015 were randomized to either receive 100 mg of intravenous hydrocortisone followed by 0.5 mg of intravenous dexamethasone every 6 h for 4 doses (STER, n = 23) or to undergo surgery without steroids (NOSTER, n = 20). Postoperative cortisol levels were then used to determine the need for glucocorticoids after surgery. Data regarding postoperative cortisol levels, hospital stay length, and complications were collected.

RESULTS: Mean postoperative 8 am cortisol levels were higher in the NOSTER group compared to the STER group (745 ± 359 nmol/L and 386 ± 193 nmol/L, respectively, P = .001) and more patients were discharged on glucocorticoids in the STER group (42% vs 12%, P = .07). There was no difference in the incidence of postoperative complications, including hyperglycemia, diabetes insipidus, or permanent adrenal insufficiency. Permanent adrenal insufficiency occurred in 8% of patients.

CONCLUSION: Perioperative steroids can be safely withheld in patients with an intact HPA axis undergoing TSS. Although administration of perioperative glucocorticoids does not appear to increase the risk of complications, it may interfere with assessment of the HPA axis after surgery.

A modern series of subdiaphragmatic craniopharyngiomas

J Neurosurg 131:526–531, 2019

The endoscopic endonasal approach has been proposed as a primary surgical strategy for select cranio- pharyngiomas. However, those tumors that arise from the sella have not been classified with the other craniopharyn- gioma subtypes in terms of surgical nuances, intraoperative findings, and postoperative outcomes. The authors describe their experience with a select subtype of craniopharyngioma arising within the sella subjacent to the diaphragma sellae and refer to these tumors as type 0.

METHODS After obtaining IRB approval, three institutions retrospectively reviewed their data collected from 2005 to 2017. Patients eligible for inclusion in the study were those who had tumors that originated from the sella inferior to the diaphragma sellae. Demographic, clinical, radiological, surgical, and follow-up data were examined and analyzed.

RESULTS Twenty-eight patients (average age 19.3 years, range 3–60 years) were included in this study. Sixteen pa- tients (57%) were younger than 18 years of age. All patients had characteristic imaging features of an expanded sella. Seventy-five percent of the patients presented with some form of visual field deficit (89% had radiographic optic appa- ratus compression) and 39% with hypopituitarism. The average maximal tumor diameter in the axial, coronal, or sagittal plane was 3.1 cm. Gross-total resection was achieved in 82% of the patients. Twenty-one percent of patients experi- enced an iatrogenic complication, and there were only two cases (7%) of postoperative cerebrospinal fluid (CSF) leak- age. Only two patients (7%) required the use of a nasoseptal flap as part of their original reconstruction. Pathology was uniformly the adamantinomatous subtype. Postoperative objective visual outcomes were improved in 71% of the patients with visual symptoms or visual field deficits on presentation and stable in 24%. Mean follow-up was 45.1 months (range 3–120 months) with an 18% recurrence rate at a mean of 44.4 months (range 10–84 months). One patient was lost to follow-up. Thirty-six percent of patients received postoperative radiation to treat recurrence or residual tumor. Endocrine data are also presented.

CONCLUSIONS Craniopharyngiomas that originate within the sella below the diaphragma sellae are a select subtype characterized by 1) an enlarged sella, 2) an intact diaphragma sellae at surgery, and 3) an adamantinomatous pathology. These tumors can be treated transnasally without the absolute need for neurovascular flap reconstruction, as there is a low risk of CSF leakage.

Low-Dose Gamma Knife Radiosurgery for Acromegaly

Neurosurgery, Volume 85, Issue 1, July 2019, Pages E20–E30

Remission rate is associated with higher dose of Gamma Knife Radio- surgery (GKRS; Gamma Knife: Elekta AB, Stockholm, Sweden) for acromegaly, but the dose ≥25 Gy is not always feasible when the functioning adenoma is close to optic apparatus

OBJECTIVE: To evaluate the efficacy and safety of low-dose (<25 Gy) GKRS in the treatment of patients with acromegaly.

METHODS: Single-center retrospective review of acromegaly cases treated with GKRS between June 1994 and December 2016. A total of 76 patients with the diagnosis of acromegaly who were treated with low-dose GKRS were selected for inclusion. Patients were treated with a median margin dose, isodose line, and treatment volume of 15.8 Gy, 57.5%, and 4.8 mL, respectively. Any identifiable portion of the optic apparatus was limited to a radiation dose of 10 Gy. All patients underwent full endocrine, ophthalmological, and imaging evaluation prior to and after GKRS treatments, and results of these were analyzed.

RESULTS: Biochemical remission was achieved in 33 (43.4%) patients. Actuarial remission rates were 20.3%, 49.9%, and 76.3% at 4, 8, and 12 yr, respectively. Absence of cavernous sinus invasion (P = .042) and lower baseline insulin-like growth factor-1 levels (P = .019) were significant predictors of remission. New hormone deficiencies were found in 9 (11.8%) patients. Actuarial hormone deficiency rates were 3%, 14%, and 22.2% at 4, 8, and 10 yr, respectively. Two (2.6%) patients who achieved initial remission experienced recurrence. No optic complications were encountered.

CONCLUSION: Reasonable remission and new hormone deficiency rates can be achieved with low-dose GKRS for acromegaly. These rates may be comparable to those with standard GKRS margin doses.

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.

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.