Traditional Transcranial Approaches Research Articles

Endoscopic trans-eustachian tube approach: identifying the precise landmarks, a novel radiological and anatomical evaluation

PurposeThe endoscopic trans-eustachian approach (ETETA) is a less invasive approach to the infratemporal fossa (ITF), providing superior exposure compared to traditional transcranial approaches. The anatomy of the pharyngotympanic (eustachian) tube and adjacent neurovascular structures is complex and requires in-depth knowledge to safely perform this approach. We present a cadaveric and radiological assessment of critical anatomic considerations for ETETA.MethodsSix adult cadaveric heads were dissected alongside examination of 50 paranasal sinus CT scans. Key anatomic relationships of the pharyngotympanic tube and adjacent structures were qualitatively and quantitatively evaluated. Descriptive statistics were performed for quantitative data.ResultsAnatomical and radiological measurements showed lateralization of the pharyngotympanic tube allows access to the ITF. The pharyngotympanic tube has bony and cartilaginous parts with the junction formed by the sphenoid spine and foramen spinosum. The bony part and tendon of the tensor tympani muscle were located at the posterior genu of the internal carotid artery. The anterior and inferior wall of the carotid canal was located between the horizontal segment of the internal carotid artery and petrous segment of the cartilaginous pharyngotympanic tube.ConclusionThe combination of preoperative radiographic assessment and anatomical correlation demonstrates a safe and effective approach to ETETA, which allowed satisfactory visualization of ITF. The morphological evaluation showed that the lateralization of the pharyngotympanic tube and related structures allowed a surgical corridor to reach the ITF. Endoscopic surgery through the pharyngotympanic tube is challenging, and in-depth understanding of the key anatomic relationships is critical for performing this approach.

Supraorbital Eyebrow Approach for Translamina Terminalis Resection of Third Ventricle Metastasis: 2-Dimensional Operative Video.

Tumors involving the third ventricle are rare, accounting for 0.6%-0.9% of all brain tumors. This deep-seated cavity is surrounded by critical neurovascular structures, making safe surgical resection of lesions in this region challenging. Traditionally, tumors of the third ventricle have been approached through a craniotomy and microsurgical resection.1-4 The supraorbital keyhole approach is a minimally invasive technique that can be used with minimal retraction of the brain and limited craniotomy while establishing a surgical field comparable with what can be achieved using traditional transcranial approaches. In this video, we describe the case of a 54-year-old man who underwent a supraorbital eyebrow approach for translamina terminalis resection of papillary thyroid carcinoma metastasis to the third ventricle. A gross total resection was achieved. The results achieved in our series are comparable with previously published reports of patients who underwent surgical resection of metastatic lesions involving the third ventricle.5-11 The patient consented to the procedure and to the publication of his image.

Olfactory groove meningiomas: supraorbital keyhole versus orbitofrontal, frontotemporal, or bifrontal approaches.

Olfactory groove meningiomas (OGMs) often require surgical removal. The introduction of recent keyhole approaches raises the question of whether these tumors may be better treated through a smaller cranial opening. One such approach, the supraorbital keyhole craniotomy, has never been compared with more traditional open transcranial approaches with regard to outcome. In this study, the authors compared clinical, radiographic, and functional quality of life (QOL) outcomes between the keyhole supraorbital approach (SOA) and traditional transcranial approach (TTA) for OGMs. They sought to examine the potential advantages and disadvantages of open/TTA versus keyhole SOA for the resection of OGMs in a relatively case-matched series of patients. A retrospective, single-institution review of 57 patients undergoing a keyhole SOA or larger traditional transcranial (frontotemporal, pterional, or bifrontal) craniotomy for newly diagnosed OGMs between 2005 and 2023 was performed. Extent of resection, olfaction, length of stay (LOS), radiographic volumetric assessment of postoperative vasogenic and cytotoxic edema, and QOL (using the Anterior Skull Base Questionnaire) were assessed. Thirty-two SOA and 25 TTA patients were included. The mean EOR was not significantly different by approach (TTA: 99.1% vs SOA: 98.4%, p = 0.91). Olfaction was preserved or improved at similar rates (TTA: 47% vs SOA: 43%, p = 0.99). The mean LOS was significantly shorter for SOA patients (4.1 ± 2.8 days) than for TTA patients (9.4 ± 11.2 days) (p = 0.002). The authors found an association between an increase in postoperative FLAIR cerebral edema and TTA (p = 0.031). QOL as assessed by the ASQB at last follow-up did not differ significantly between groups (p = 0.74). The keyhole SOA was associated with a statistically significant decrease in LOS and less postoperative edema relative to traditional open approaches.

Surgical management of tuberculum sellae meningioma: Transcranial approach or endoscopic endonasal approach?

BackgroundTuberculum sellae meningioma (TSM), a common benign tumor in the sellae region, usually causes neurological deficits, such as vision impairment, by squeezing the peripheral neurovascular structures. Surgical management is recommended as the optimal strategy for TSM treatment and vision restoration. However, it remains challenging to resect TSM in the traditional transcranial approach (TCA). Recently, the endoscopic endonasal approach (EEA) has emerged as an effective option in skull base surgeries. Besides the effectivity, the advantages and limitations of EEA in TSM surgery remain controversial.ObjectWe compared the surgical outcomes and complications between TCA and EEA surgeries to identify the principles in TSM surgical management.MethodsRetrospective analysis was performed on the patients, who underwent TSM surgery in Wuhan Union Hospital between January 2017 and December 2021. The patients were assigned to TCA or EEA group according to the surgery they experienced. All patients were analyzed with the extent of tumor resection, vision outcome, postoperative complications, and follow-up results.ResultsA total of 112 patients were enrolled in this study, including 78 in TCA group and 34 in EEA group. The mean follow-up was 20.5 months (range 3–36 months). There were no statistically significant differences in patient demographic data, preoperative symptoms, and tumor characteristics between TCA and EEA groups. Both TCA and EEA surgeries are effective in TSM resection with relatively high gross total resection rates (85.9% in TCA vs. 91.2% in EEA, p > .05). Meanwhile, EEA surgery has a better outcome in vision restoration or stabilization than TCA surgery (74.6% in TCA vs. 93.1% in EEA, p < .05). Whereas EEA surgery causes more occurrences of cerebrospinal fluid (CSF) leakage than TCA surgery (0% in TCA vs. 11.8% in EEA, p < .05).ConclusionBoth TCA and EEA surgeries are effective in TSM resection. EEA surgery has a better outcome in vision restoration or stabilization than TCA surgery, but induces higher risk of CSF leakage. As each approach has unique advantages and limitations, we must take all aspects into consideration, including approach feathers, tumor characteristics, and clinical requirements, to make the optimal choice in TSM surgical management.

Critical appraisal of minimally invasive keyhole surgery for intracranial meningioma in a large case series.

Meningioma surgery has evolved over the last 20 years with increased use of minimally invasive approaches including the endoscopic endonasal route and endoscope-assisted and gravity-assisted transcranial approaches. As the "keyhole" concept remains controversial, we present detailed outcomes in a cohort series. Retrospective analysis was done for all patients undergoing meningioma removal at a tertiary brain tumor referral center from 2008-2021. Keyhole approaches were defined as: use of a minimally invasive "retractorless" approach for a given meningioma in which a traditional larger approach is often used instead. The surgical goal was maximal safe removal including conservative (subtotal) removal for some invasive locations. Primary outcomes were resection rates, complications, length of stay and Karnofsky Performance Scale (KPS). Secondary outcomes were endoscopy use, perioperative treatments, tumor control and acute MRI FLAIR/T2 changes to assess for brain manipulation and retraction injury. Of 329 patients, keyhole approaches were utilized in 193(59%) patients (mean age 59±13; 30 (15.5%) had prior surgery) who underwent 213 operations; 205(96%) were skull base location. Approaches included: endoscopic endonasal (n = 74,35%), supraorbital (n = 73,34%), retromastoid (n = 38,18%), mini-pterional (n = 20,9%), suboccipital (n = 4,2%), and contralateral transfalcine (n = 4,2%). Primary outcomes: Gross total/near total (>90%) resection was achieved in 125(59%) (5% for petroclival, cavernous sinus/Meckel's cave, spheno-cavernous locations vs 77% for all other locations). Major complications included: permanent neurological worsening 12(6%), CSF leak 2(1%) meningitis 2(1%). There were no DVTs, PEs, MIs or 30-day mortality. Median LOS decreased from 3 to 2 days in the last 2 years; 94% were discharged to home with favorable 90-day KPS in 176(96%) patients. Secondary outcomes: Increased FLAIR/T2 changes were noted on POD#1/2 MRI in 36/213(17%) cases, resolving in all but 11 (5.2%). Endoscopy was used in 87/139(63%) craniotomies, facilitating additional tumor removal in 55%. Tumor progression occurred in 26(13%) patients, mean follow-up 42±36 months. Our experience suggests minimally invasive keyhole transcranial and endoscopic endonasal meningioma removal is associated with comparable resection rates and low complication rates, short hospitalizations and high 90-day performance scores in comparison to prior reports using traditional skull base approaches. Subtotal removal may be appropriate for invasive/adherent meningiomas to avoid neurological deficits and other post-operative complications, although longer follow-up is needed. With careful patient selection and requisite experience, these approaches may be considered reasonable alternatives to traditional transcranial approaches.

Endoscopic Endonasal Approach to the Third Ventricle Using the Surgical Corridor of the Reverse Third Ventriculostomy: Anatomo-Surgical Nuances.

Objective Surgical access to the third ventricle can be achieved through various corridors depending on the location and extent of the lesion; however, traditional transcranial approaches risk damage to multiple critical neural structures. Methods Endonasal approach similar to corridor of the reverse third ventriculostomy (ERTV) was surgically simulated in eight cadaveric heads. Fiber dissections were additionally performed within the third ventricle along the endoscopic route. Additionally, we present a case of ERTV in a patient with craniopharyngioma extending into the third ventricle. Results The ERTV allowed adequate intraventricular visualization along the third ventricle. The extracranial step of the surgical corridor included a bony window in the sellar floor, tuberculum sella, and the lower part of the planum sphenoidale. ERTV provided an intraventricular surgical field along the foramen of Monro to expose an area bordered by the fornix anteriorly, thalamus laterally, anterior commissure anterior superiorly, posterior commissure, habenula and pineal gland posteriorly, and aqueduct of Sylvius centered posterior inferiorly. Conclusion The third ventricle can safely be accessed through ERTV either above or below the pituitary gland. ERTV provides a wide exposure of the third ventricle through the tuber cinereum and offers access to the anterior part as far as the anterior commissure and precommissural part of fornix and the whole length of the posterior part. Endoscopic ERTV may be a suitable alternative to transcranial approaches to access the third ventricle in selected patients.

Trans-eyebrow supraorbital keyhole approach for suprasellar and intra-suprasellar Rathke cleft cysts: the experience of 16 cases and a literature review

Background Purely suprasellar and some complex intra-suprasellar Rathke cleft cysts (RCCs) are commonly treated via extended endonasal endoscopic approach or traditional transcranial approach. The feasibility of the trans-eyebrow supraorbital keyhole approach (TSKA) for RCCs was evaluated in this retrospective study. Methods A cohort of 16 patients (11 females and 5 males) with RCC was surgically treated via TSKA between January 2013 and November 2021. The medical data and follow-up results were analyzed. Results Eight patients had a purely suprasellar RCC, and 8 patients had an intra-suprasellar RCC with most of pituitary gland occupying the sellar floor. The mean maximal size of the cysts was 15.4 (range 7–29) mm. Postoperatively, complete cyst drainage was achieved in 15 (93.7%) patients. Preoperative headache, visual dysfunction, and hypopituitarism improved in 12 (100.0%), 3 (75.0%) and 3 (75.0%) patients, respectively, and hyperprolactinemia normalized in all patients. Except 2 (12.5%) cases of transient diabetes insipidus (TDI), no other complications were observed. During the mean follow-up period of 41.0 (range 4–102) months, 1 (6.3%) radiological recurrence was found. Conclusions For the treatment of purely suprasellar and some intra-suprasellar RCCs with most of the pituitary occupying the sellar floor, the endoscopic TSKA has the advantage of the minimal invasiveness, excellent visualization of the intrasellar compartment, no additional damage to the underlying pituitary gland, and no risk of CSF leakage. TDI or DI is relative commonly found in treatment of these RCCs. During surgery, care should be taken to avoid damage to the surrounding structures, including the pituitary stalk.

Endoscopic Endonasal Approach to the Third Ventricle Using the Surgical Corridor of the Reverse Third Ventriculostomy: Anatomo-Surgical Nuances

Abstract Objective Surgical access to the third ventricle can be achieved through various corridors depending on the location and extent of the lesion; however, traditional transcranial approaches risk damage to multiple critical neural structures. Methods Endonasal approach similar to corridor of the reverse third ventriculostomy (ERTV) was surgically simulated in eight cadaveric heads. Fiber dissections were additionally performed within the third ventricle along the endoscopic route. Additionally, we present a case of ERTV in a patient with craniopharyngioma extending into the third ventricle. Results The ERTV allowed adequate intraventricular visualization along the third ventricle. The extracranial step of the surgical corridor included a bony window in the sellar floor, tuberculum sella, and the lower part of the planum sphenoidale. ERTV provided an intraventricular surgical field along the foramen of Monro to expose an area bordered by the fornix anteriorly, thalamus laterally, anterior commissure anterior superiorly, posterior commissure, habenula and pineal gland posteriorly, and aqueduct of Sylvius centered posterior inferiorly. Conclusion The third ventricle can safely be accessed through ERTV either above or below the pituitary gland. ERTV provides a wide exposure of the third ventricle through the tuber cinereum and offers access to the anterior part as far as the anterior commissure and precommissural part of fornix and the whole length of the posterior part. Endoscopic ERTV may be a suitable alternative to transcranial approaches to access the third ventricle in selected patients.

Surgical Outcomes of Endoscopic Endonasal Versus Transcranial Resections of Adult Craniopharyngioma: A Meta-Analysis.

The endoscopic endonasal approach (EEA) has been gaining popularity for resection of adult craniopharyngiomas. However, the safety and effectiveness of the procedure in comparison to the traditional transcranial approach (TCA) remains unestablished as previous reviews are outdated. A literature search without language restriction was conducted in PubMed, Cochrane database, and Web of Science from conception to July 9, 2021. Cohort studies and case series that compared EEA with TCA and assessed postoperative complications, recurrence, and 30-day mortality were included. Articles, where data for adult populations could not be extracted or calculated, were excluded. Article selection and data extraction in a predesigned data extraction form were conducted in duplicate. Pooled participant data were included in a random-effects model. The search yielded 227 articles, from which eight cohort studies containing 11,395 patients were included (EEA: 6,614 patients, TCA: 4,781 patients). Six studies were good quality and two were fair quality according to the Newcastle Ottawa Scale. There were significantly higher rates of cerebrospinal fluid leak (risk ratio [RR]=0.23, 95% confidence interval [CI] 0.17-0.32, p<0.00001, I²=0%) and lower rates of postoperative hypopituitarism (RR=1.40, 95% CI 1.30-1.51, p<0.00001, I²=0%), hydrocephalus (RR=6.95, 95% CI 5.78-8.36, p<0.00001, I²=0%), visual impairment (RR=1.52, 95% CI 1.34-1.73, p<0.00001, I²=0%), and 30-day mortality (RR=5.63, 95% CI 3.87-8.19, p<0.00001, I²=0%) after EEA. Non-significant lower rates of postoperative diabetes insipidus (RR=1.12, 95% CI 0.78-1.61, p=0.53, I²=85%) and recurrence of tumor (RR=2.69, 95% CI 0.35-20.81, p=0.34, I²=47%) were seen after EEA. EEA may be associated with reduced postoperative hypopituitarism, hydrocephalus, visual impairment, and 30-day mortality and higher rates of cerebrospinal fluid leak. These findings do not account for differences in tumor size and extension between the EEA and TCA cohorts. Further research on patients with comparable tumor characteristics is required to fully assess outcomes.

Perioperative Complications in Endoscopic Endonasal versus Transcranial Resections of Adult Craniopharyngiomas

Adult craniopharyngiomas are low-grade tumors of the pituitary infundibulum that can be locally aggressive and frequently present with profound visual deficits and endocrinopathies. Surgical resection remains the preferred initial treatment for these lesions, and recently endoscopic endonasal approaches (EEAs) have become increasingly used. However, minimal data exist comparing these techniques with traditional transcranial (TC) methods. The purpose of this study was to evaluate perioperative differences in EEA and TC approaches for adult craniopharyngiomas over the past several decades. Craniopharyngioma surgeries in the Nationwide Inpatient Sample from 1998 to 2014 were identified. Complication rates, mortality rates, and annual treatment trends were stratified by procedure. Annual caseload was assessed with linear regression, and multivariate logistic regression models were created to determine predictors of inpatient mortality and perioperative complications. From 1998-2014, a significant increase in EEAs for craniopharyngiomas (+4.36/year, r2= 0.80, P < 0.0001) was observed. In contrast, no increase in TC surgeries for these lesions was seen. In multivariate analysis, EEAs were more likely to experience postoperative cerebrospinal fluid leak (odds ratio= 2.61, P < 0.0001). However, EEAs were protective against all other perioperative complications including diabetes insipidus, panhypopituitarism, visual impairment, and even mortality (odds ratio= 0.41, P= 0.0007). Over the past several decades, utilization of EEAs to resect adult craniopharyngiomas has increased. EEAs appear to be associated with lower rates of perioperative mortality and complications. However, long-term, prospective studies controlling for tumor size, location, and preoperative symptomatology are needed to determine when one approach should be used preferentially over the other.

Endoscopic endonasal approach for craniopharyngiomas.

The operative management of craniopharyngiomas has evolved over the last two decades. Traditional transcranial microsurgical approaches were the only option until the advent of the endoscopic endonasal approach. It has given surgeons the ability to tackle a challenging entity from a new perspective with comparable if not superior results. In this review we outline the advancements in endoscopic endonasal approach for craniopharyngiomas, address controversies and review the current literature.

Single surgeon experience with minimally invasive supraorbital craniotomy versus bifrontal craniotomy for anterior skull base meningiomas.

Background: Anterior skull base meningiomas (ASBMs) account for about 10% of meningiomas. Bifrontal craniotomy (BFC) represents the traditional transcranial approach to accessing meningiomas in these locations. Supraorbital craniotomy (SOC) provides a minimally invasive subfrontal corridor in select patients. Here, we present our series of ASBM accessed by SOC and BFC by a single surgeon to review decision-making and compare outcomes in both techniques.Methods: Thirty-three patients were identified with ASBM. Age, tumor characteristics, presenting symptoms, postoperative complications, and outcomes were analyzed.Results: Bifrontal and SOC were performed in 13 and 20 patients, respectively. Mean follow-up time was 98.4 months. Patients undergoing SOC had smaller tumor size, located farther from the posterior table of frontal sinus, had less peritumoral edema, and decreased length of stay compared to patients undergoing BFC. Extent of resection was slightly better with BFC (99.8%) compared to SOC (91.8%), although this difference did not reach statistical significance. Recurrence-free survival and rate of re-do surgeries were not different between two groups. BFC was associated with higher rates of postoperative encephalomalacia.Conclusion: SOC provides an excellent surgical option for ASBMs providing comparable extent of resection, minimal manipulation of brain, and excellent cosmetic outcomes for patients. The patient selection is key to maximize the benefits from this approach.

Endoscope-assisted transcranial surgery for anterior skull base meningiomas

Anterior skull base meningiomas are benign, dural-based tumors that originate from the tuberculum sellae, planum sphenoidale or olfactory groove. A multitude of traditional transcranial approaches have been effectively used for resection of these tumors. However, in the era of minimally invasive neurosurgery, the endoscopic endonasal and the endoscope-assisted or endoscope-controlled supraorbital keyhole eyebrow approaches stand out as the two main options utilized to resect these tumors. The supraorbital keyhole approach minimizes brain retraction, tissue dissection and length of the skin incision. Consequently, this approach is associated with a lower complication profile and much better cosmetic results in comparison to classic approaches. With endoscopic assistance or control, the approach provides an excellent view of anterior skull base meningiomas and enables optic nerve decompression when angled scopes are used. In our opinion, endoscopes will ultimately replace the surgical microscopes as the viewing tools in this type of surgery. A limited number of studies have directly compared the endoscopic endonasal approach versus the supraorbital keyhole one for resection of anterior cranial base meningiomas. In these studies, scores and algorithms have been suggested to help select the suitable approach. The practical value of these algorithms still needs to be validated by further research. Although the endoscope-assisted or -controlled supraorbital keyhole approach offers a minimally invasive and highly effective approach for excision of anterior cranial base meningiomas, the ideal approach should be tailored to the individual patient according to the tumor size, lateral extension, optic canal involvement, extent of vascular encasement and surgeon’s experience.

Endoscopic endonasal surgery to treat intrinsic brainstem lesions: correlation between anatomy and surgery.

The endoscopic endonasal approach (EEA) has been proposed as an alternative in the surgical removal of ventral brainstem lesions. However, the feasibility and limitations of this approach to treat such pathologies are still poorly understood. This study aimed to report our experience in five consecutive cases of intrinsic brainstem lesions that were managed via an EEA, as well as the specific anatomy of each case. All patients were treated in a single center by a multidisciplinary surgical team between 2015 and 2019. Before surgery, a dedicated anatomical analysis of the brainstem safe entry zone was performed, and proper surgical planning was carried out. Neurophysiological monitoring was used in all cases. Anatomical dissections were performed in three human cadaveric heads using 0° and 30° endoscopes, and specific 3D reconstructions were executed using Amira 3D software. All lesions were located at the level of the ventral brainstem. Specifically, one mesencephalic cavernoma, two pontine ca- vernomas, one pontine gliomas, and one medullary diffuse midline glioma were reported. Cerebrospinal fluid leak was the major complication that occurred in one case (medullary diffuse midline glioma). From an anatomical standpoint, three main safe entry zones were used, namely the anterior mesencephalic zone (AMZ), the peritrigeminal zone (PTZ, used in two cases), and the olivar zone (OZ). Reviewing the literature, 17 cases of various brainstem lesions treated using an EEA were found. To our knowledge, this was the first preliminary clinical series of intrinsic brainstem lesions treated via an EEA presented in the literature. The EEA can be considered a valid surgical alternative to traditional transcranial approaches to treat selected intra-axial brainstem lesions located at the level of the ventral brainstem. To achieve good results, surgery must involve comprehensive anatomical knowledge, meticulous preoperative surgical planning, and intraoperative neurophysiological moni- toring.

Visual Outcomes After Endoscopic Endonasal Resection of Orbital Lesions

The endoscopic endonasal approach (EEA) has been increasing in popularity as an alternative to traditional transcranial and transorbital approaches in the treatment of orbital pathological entities. The purpose of the present study was to examine the outcomes of patients who had undergone EEA resection of orbital lesions at our center. We performed a retrospective medical record review of patients who had undergone the EEA for resection of orbital lesions and orbital apex decompression from January 1, 2006 to December 1, 2019. For all the patients, the demographic data, presenting symptoms, symptom duration, imaging data, operative details, and postoperative outcomes were collected and reviewed. Nine patients underwent endoscopic endonasal resection of orbital lesions and orbital apex decompression at our center, including 6 male patients and 3 female patients. The mean age was 49.4 years, and the mean follow-up period was 3.8 years (range, 1-13.5 years). The orbital pathological lesions that were treated included nasopharyngeal carcinoma, hemangioma, fibrous dysplasia, IgG4 pseudotumor, inverted papilloma, angioleiomyoma, adenocarcinoma, and neuroendocrine paraganglioma metastasis. All the patients presented with exophthalmos of the affected orbit. Of the 9 patients, 5 presented with decreased visual acuity on examination. Postoperatively, 1 of these 5 patients had improved to baseline visual acuity, 3 had stable vision, and 1 had brief improvement before experiencing progressive visual decline 1 month postoperatively. Two patients presented with diplopia, and both improved postoperatively. Three patients experienced new, transient, and self-limiting postoperative diplopia. For patients with orbital lesions causing compressive optic neuropathy, the endoscopic endonasal approach can be used as an alternative strategy in appropriately selected patients.

Combined strategy of maximal endoscopic endonasal resection and early radiation therapy for complex cystic and solid craniopharyngioma: operative video.

Craniopharyngioma is a rare and benign intracranial tumor of the sellar and suprasellar region. Historically, these tumors were mostly accessed through transcranial corridors and resected with microsurgical techniques. Endoscopic endonasal surgery has recently gained popularity in the treatment of these tumors and has shown at least comparable results to transcranial approaches. The endoscopic endonasal approach provides direct midline access through a transplanum transtuberculum corridor and gives excellent visualization of the undersurface of the optic chiasm to allow safe bimanual sharp dissection of the tumor from the hypothalamus. In this operative video, we demonstrate the case of a 56-year-old female who had a complex craniopharyngioma with solid and cystic components extending superolaterally into the right frontal lobe. This lesion was invasive and partially encased the right optic nerve, optic chiasm, and anterior communicating artery complex. Although a traditional transcranial approach could have been utilized, we elected for an endoscopic endonasal approach for a maximal safe near-total resection, preserving the neurovascular structures. The patient underwent radiation therapy with favorable regression of the residual tumor on subsequent imaging studies. This case illustrates the feasibility of a combined strategy of maximal safe endoscopic endonasal resection followed by early radiation therapy for a complex, invasive cystic and solid craniopharyngioma. The technical nuances of safe bimanual microsurgical dissection of tumor adhesions off of critical neurovascular structures are demonstrated.The video can be found here: https://youtu.be/z0AINLpRZGs.

Extended Endoscopic Endonasal Surgery to Ventral Skull Base Lesions

Abstract Introduction In the last two decades, Endoscopic endonasal approaches (EEAs) have undergone a significant evolution with a major shift from a transsellar approach to a variety of approaches that can directly access the midline and paramedian ventral skull base. Once the technical feasibility of any surgical approach is established; its safety (assessed through complications), and treatment outcomes (assessed through long-term follow-up) should be addressed. Aim of the Study To assess the feasibility, safety, and efficacy of EEA as a minimally invasive approach to ventral skull base lesions. Methodology and Materials this is a prospective observational study of group of 30 patients with ventral skull base lesions that were managed via endoscopic endonasal approaches. All patients’ clinical data, radiographic evaluations, procedural detail, complications, and follow-up data were recorded and analyzed. Results The mean age of patients was 50.8 years (range: 18-74 years), with a male:female ration of 1:1.72. The most commonly encountered pathological entities in the cohort was meningiomas (43.3%), pituitary adenomas (23.3%). and craniopharyngiomas (13.3%). Postoperative CSF leak was observed in 6.6% of cases and was managed successfully. There were no cases with postoperative infection in the cohort. Other procedure-related complications include transient diabetes insipidus (10%), pneumocephaly (3.3%), Syndrome of inappropriate ADH secretion (3.3%). Gross total resection was achieved in 93.3% of cases. Improvement of preoperative symptoms was recorded in 89.2% of cases. The mean follow-up duration was 17.8 ± 2.7 months. Conclusion EEAs provide direct access and better visualization to the ventral skull base without brain retraction and with minimal neurovascular manipulation, leading to less morbidity and mortality. EEA can be considered a feasible, safe, and effective tool on the armamentarium of skull base surgery. EEAs should not be considered as a replacement to the traditional transcranial approaches; rather. EEAs are deemed as a complementary route and a potential alternative to conventional skull base surgery in select cases.

P.102 Expanded endoscopic endonasal approach for orbital apex decompression

Background: The Endoscopic endonasal approach (EEA) has been gaining popularity in the past decade as an alternative to traditional transcranial and transorbital approaches. We have performed orbital apex decompression for a variety of pathological entities. Methods: We performed a retrospective chart review on patients who underwent EEA orbital apex decompression between January 1st 2010 and December 1st 2018 at McMaster University. Results: Eight patients underwent endoscopic endonasal orbital decompression at our center, including five male patients and three female patients. The mean age of our patients was 50.1 years. The different pathologies we treated included nasopharyngeal carcinoma, hemangioma, fibrous dysplasia, IgG4 disease, inverted papilloma, angioleiomyoma, and neuroendocrine paraganglioma. Five patients presented with visual symptoms. Postoperatively, one of these five patients improved to baseline, three had stable vision, another one had progressive visual decline despite surgical intervention. Conclusions: Endoscopic endonasal approach can be used as an alternative to decompress orbital apex pathologies in selected patients.

The impact of expanded endonasal skull base surgery on midfacial growth in pediatric patients.

Surgical resection of skull base tumors in children is increasingly accomplished through an expanded endonasal approach (EEA). We aim to evaluate the potential effect of the EEA on midfacial growth as a result of iatrogenic damage to nasal growth zones. We performed a retrospective review of children undergoing craniopharyngioma resection via an open transcranial or EEA. Pre- and postoperative magnetic resonance imaging was evaluated for growth in four midfacial measurements based on established cephalometric landmarks: anterior midface height, posterior midface height, palatal length, and sella-nasion distance. Statistical analysis was conducted using a mixed-effects linear regression model. Twenty-two patients underwent an EEA (n = 12) or open transcranial approach (n = 10) for tumor resection with 3 years of imaging follow-up. There was no difference in midfacial growth between groups for each measurement. Compared to the open group, patients undergoing EEA demonstrated relative anterior midface height growth of -0.42 mm (P = 0.880), posterior midface height growth of -0.44 mm (P = 0.839), palatal length growth of 0.35 mm (P = 0.894), and sella-nasion distance growth of -2.16 (P = 0.365). We found no difference in midfacial growth measurements between patients undergoing craniopharyngioma resection via an EEA and the open transcranial route after 3 years of imaging follow-up. Preliminary results on midfacial growth demonstrate that the EEA is a safe alternative to traditional transcranial approaches for the pediatric population. Further investigation with larger sample size and longer duration of follow-up is warranted to more thoroughly investigate the long-term implications of the EEA to the skull base. 3 Laryngoscope, 130:338-342, 2020.

Decision-making algorithm for minimally invasive approaches to anterior skull base meningiomas.

OBJECTIVE Anterior skull base meningiomas are benign lesions that cause neurological symptoms through mass effect on adjacent neurovascular structures. While traditional transcranial approaches have proven to be effective at removing these tumors, minimally invasive approaches that involve using an endoscope offer the possibility of reducing brain and nerve retraction, minimizing incision size, and speeding patient recovery; however, appropriate case selection and results in large series are lacking. METHODS The authors developed an algorithm for selecting a supraorbital keyhole minicraniotomy (SKM) for olfactory groove meningiomas or an expanded endoscopic endonasal approach (EEA) for tuberculum sella (TS) or planum sphenoidale (PS) meningiomas based on the presence or absence of olfaction and the anatomical extent of the tumor. Where neither approach is appropriate, a standard transcranial approach is utilized. The authors describe rates of gross-total resection (GTR), olfactory outcomes, and visual outcomes, as well as complications, for 7 subgroups of patients. Exceptions to the algorithm are also discussed. RESULTS The series of 57 patients harbored 57 anterior skull base meningiomas; the mean tumor volume was 14.7 ± 15.4 cm3 (range 2.2-66.1 cm3), and the mean follow-up duration was 42.2 ± 37.1 months (range 2-144 months). Of 19 patients with olfactory groove meningiomas, 10 had preserved olfaction and underwent SKM, and preservation of olfaction in was seen in 60%. Of 9 patients who presented without olfaction, 8 had cribriform plate invasion and underwent combined SKM and EEA (n = 3), bifrontal craniotomy (n = 3), or EEA (n = 2), and one patient without both olfaction and cribriform plate invasion underwent SKM. GTR was achieved in 94.7%. Of 38 TS/PS meningiomas, 36 of the lesions were treated according to the algorithm. Of these 36 meningiomas, 30 were treated by EEA and 6 by craniotomy. GTR was achieved in 97.2%, with no visual deterioration and one CSF leak that resolved by placement of a lumbar drain. Two patients with tumors that, based on the algorithm, were not amenable to an EEA underwent EEA nonetheless: one had GTR and the other had a residual tumor that was followed and removed via craniotomy 9 years later. CONCLUSIONS Utilizing a simple algorithm aimed at preserving olfaction and vision and based on maximizing use of minimally invasive approaches and selective use of transcranial approaches, the authors found that excellent outcomes can be achieved for anterior skull base meningiomas.