Cost-effectiveness of endoscopic endonasal vs transcranial approaches for olfactory groove meningioma

BACKGROUND

Endoscopic endonasal approaches (EEAs) have been adopted as an alternative to standard transcranial approaches for olfactory groove meningiomas (OGMs). However, the relative cost-effectiveness remains controversial.

METHODS

Cost-utility analysis from a societal perspective comparing EEA vs transcranial approaches for OGM was used in this study. Surgical treatment was modeled using decision analysis, and a Markov model was adopted over a 20-year horizon. Parameters were obtained from literature review. Costs were expressed in 2017 Canadian dollars.

RESULTS

In the base case, EEA was cost-effective compared with transcranial surgery with an incremental cost-effectiveness ratio of $33 523 ($30 475 USD)/QALY. There was a 55% likelihood that EEA was cost-effective at a willingness-to-pay of $50 000/QALY. EEA remained cost-effective at a cerebrospinal fluid leak rate below 60%, gross total resection rate above 25%, and base cost less than $66 174 ($60 158 USD).

CONCLUSION

EEA may be a cost-effective alternative to transcranial approaches for selected OGM.

A Case of Endonasal Endoscopic Surgery for Intraorbital Metastasis of Gastric Ring Cell Carcinoma

Gastric signet ring cell carcinoma has well-known metastatic features, including peritoneal dissemination and carcinomatous lymphangitis of the lung, but no intraorbital metastases were reported previously. A woman in her 60s developed left eye pain, sudden vision loss, and headache 12 years after gastric cancer treatment. Symptoms did not improve despite steroid pulses. Craniotomy showed no malignant findings. The patient was referred to our department for symptomatic relief and biopsy due to the lack of a definitive diagnosis and no improvement in her ocular pain. Endonasal endoscopic surgery was performed for diagnostic purposes and to relieve symptoms through orbital decompression. Preoperative computed tomography examination revealed a tumor at the left medial orbit, extending to the orbital apex. Orbital decompression through the open left medial orbital wall was performed with biopsy of the intraorbital tumor. Pathological findings were consistent with metastatic signet ring cell carcinoma. Pain and subjective improvement of visual acuity were noted the day after surgery. Twelve months postoperatively, diplopia remains, but there has been no worsening of symptoms.

Managing care for patients with sinonasal and anterior skull base cancers during the COVID-19 pandemic

The SARS-CoV-2 pandemic has rapidly transformed health care delivery around the globe. Because of the heavy impact of COVID-19 spread, cancer treatments have necessarily been de-prioritized, thus exposing patients to increased risk of morbidity and mortality due to delayed care. In this scenario, cancer specialists need to assess critical oncology patients case by case to carefully balance risk vs benefit in treating tumors and preventing SARS-CoV-2 infection. Here, we report early insights into how the management of patients with sinonasal and anterior skull base cancer might be affected by the COVID-19 pandemic. We provide recommendations for preoperative tests, indications for immediate care vs possible delayed treatment, and warnings relating to dural resection and intracranial dissection, given the potential neurotropism of SARS-CoV2 and practical suggestions for managing cancer care in a period of limited resources. We also postulate some thoughts on the promising role of telemedicine in multidisciplinary case discussions and posttreatment surveillance.

Efficacy and Safety of Intraoperative Lumbar Drain in Endoscopic Skull Base Tumor Resection: A Meta-Analysis

Objectives: This study aims to evaluate the efficacy and safety of lumbar drainage (LD) in preventing cerebrospinal fluid (CSF) leaks after endoscopic skull base tumor resection. Methods: A systematic online search was conducted using PubMed, Embase, Scopus, Web of Science, and Cochrane Library from January 2006 to July 2019. Data analyses were performed by the Cochrane Collaboration's Review Manager 5.3 software. Results: Eight studies, including two randomized controlled trials and six observational studies, met the inclusion criteria. No significant difference was found in the post-operative CSF leak rate between the LD group and the non-LD group [odds ratio (OR), 0.80; 95%CI, 0.37-1.74; I 2 = 37%; P = 0.57). Subgroup analysis of the intraoperative high-flow leaks, including 4 studies and 313 patients, showed that LD was associated with reduced likelihood of post-operative CSF leak (OR, 0.37; 95%CI, 0.17-0.83; I 2 = 0%; P = 0.02). The placement of LD was related to increased risk of headache compared with non-LD use, and no significant difference was found in the occurrence of deep vein thromboses and pulmonary emboli between two groups. Conclusion: LD is not recommended in all patients undergoing endoscopic skull base tumor resection. However, for patients with intraoperative high-flow leaks, LD is effective and safe in reducing risk of CSF leak.

Endoscopic endonasal surgery for giant pediatric craniopharyngioma

Pediatric craniopharyngiomas that were once thought to be inoperable or considered only for salvage medical therapy are now being reconsidered for aggressive surgical resection via endoscopic endonasal approaches. Here we review the operative video case of an 11-year-old with a giant complex craniopharyngioma that was resected via an endoscopic endonasal approach. Due to the extent of tumor burden near the basilar apex, a transclival approach was necessary. To accomplish this, a wide sphenoidotomy, posterior ethmoidectomy, and resection of the middle turbinate were necessary to create enough working space for the resection. We also highlight several key innovations in pediatric endoscopic endonasal surgery management and underscore a multidisciplinary approach that allows for the safe and successful treatment of these lesions. Our multidisciplinary team involves an experienced fellowship-trained endoscopic skull base surgeon and otolaryngologist, as well as a pediatric neurosurgeon, pediatric endocrinologist, pediatric anesthesiologist, and pediatric intensivists who play important roles in the preoperative, intraoperative, and postoperative phases of care of the patient. Finally, we discuss critical surgical decision points including pituitary transposition, which has a lot of conceptual appeal when it is anatomically feasible but unfortunately, in our experience, has low functional preservation rates. Initially, we always aim to utilize pituitary transposition for tuberoinfundibular craniopharyngiomas, and once the relationship between the tumor and the stalk is determined, a decision on whether to preserve or sacrifice the stalk and pituitary gland is made. In this particular case, there was a salvageable stalk and the transposition was performed knowing that the chances for functional preservation were low. The video can be found here: https://youtu.be/ClL73FU5QIU.

[Breast cancer metastasis into a giant hormone-inactive pituitary adenoma adenoma. (Clinical case and literature review)]

Brain metastases of various types of cancer are diagnosed in 8-10% of all cancer patients. In the world literature, only 30 cases of cancer metastasis to the pituitary adenoma are described. This article presents yet another observation of a patient with breast cancer metastasis into the hormone-inactive pituitary adenoma at the Burdenko neurosurgical center, Russia The patient underwent endoscopic endonasal transsphenoid removal of the neoplasm. During microscopy and immunohistochemical studies of the biopsy, two types of tissue (pituitary adenoma and cancer metastasis) with different Ki-67 treated surgically (1% and over 40%) were found.

Analysis of 7-tesla diffusion-weighted imaging in the prediction of pituitary macroadenoma consistency

OBJECTIVE

Endoscopic surgery is an effective treatment strategy for pituitary adenomas; however, intrinsic tumor properties such as tumor consistency can challenge or preclude gross-total resection. Preoperative characterization of tumor consistency may help to guide the surgical approach and to predict the extent of resection that is possible. Advanced radiological modalities such as 7T diffusion-weighted imaging (DWI) may be useful in probing biological tissue properties of pituitary adenomas. The objective of the present study was to examine 7T DWI as a novel method of measuring the consistency of pituitary adenomas.

METHODS

Thirteen patients with pituitary macroadenomas underwent 7T MRI, including a DWI image acquisition. Tumor apparent diffusion coefficient (ADC) was normalized to the adjacent temporal gray matter ADC. All patients underwent resection, and a single neurosurgeon blinded to ADC values rated tumor firmness from 1 (least firm) to 5 (most firm) using objective criteria. The tumor specimens were evaluated histopathologically for cellularity, collagen content, and vascularity by a neuropathologist who was also blinded to ADC values. The tumor ADC was correlated with intraoperative consistency rating, histopathology, and extent of resection. Receiver operating characteristic (ROC) curve analyses were performed to identify thresholds to predict tumor consistency.

RESULTS

Corrected ADC values were significantly correlated with both tumor firmness (r = -0.60, p = 0.029) and the extent of trichrome staining (r = -0.72, p = 0.009) such that greater ADC values were associated with both decreased tumor firmness and decreased collagen staining. Correlations between ADC values and tumor vascularity were not significant (r = -0.09, p = 0.78). Corrected ADC values in totally resected tumors (1.54) were greater than those in subtotally resected tumors (0.85) (p = 0.02), and ADC values were greater with moderate tumor cellularity (1.51) than with high tumor cellularity (0.8) (p = 0.035). There was a trend-level association for partial resections to exhibit greater tumor firmness rating (3 vs 1.7; p = 0.051). Finally, the degree of trichrome staining positively correlated with tumor firmness (r = 0.60, p = 0.04). The optimal threshold for predicting intraoperative consistency rating was an ADC ratio of 0.87 (sensitivity 80%, specificity 100%, area under the curve [AUC] 0.90; p = 0.043). The optimal cutoff for distinguishing the extent of resection was 1.19 (sensitivity 85.7%, specificity 83.3% AUC 0.833; p = 0.046).

CONCLUSIONS

The authors' results suggest that a high-resolution ADC of pituitary adenomas is a sensitive measure of tumor consistency. 7T DWI may hold clinical value in the preoperative workup and surgical management of patients with pituitary macroadenomas.

Lateral nasal wall flap for endoscopic reconstruction of the skull base: anatomical study and clinical series

BACKGROUND

The lateral nasal wall (LNW) flap provides vascularized endonasal reconstruction primarily in revision surgery. Although the harvesting technique and reconstructive surface have been reported, the arterial supply to the LNW flap and its clinical implications is not well defined. This study presents anatomical dissections to clarify the vascular supply to this flap, and the associated clinical outcomes from this reconstructive technique.

METHODS

The course and branching pattern of the sphenopalatine artery (SPA) to the LNW were studied in 6 vascular latex-injected heads (11 LNW flaps total). Patients undergoing an LNW flap since 2008 were identified and the underlying pathology, indication, flap viability, and clinical outcomes were retrospectively analyzed.

RESULTS

The inferior turbinate artery arises from the LNW artery and divides into 2 branches at the most posterior aspect of the inferior turbinate bone. A smaller-caliber superficial branch travels anteriorly and branches to the LNW. A larger dominant branch travels into the inferior meatus and tangentially supplies the nasal floor. Twenty-four patients with sellar or posterior cranial fossa (PCF) defects were reconstructed with an LNW flap. Postoperative contrast enhancement of the LWN flap was identified in 95.5% of cases. Postoperative cerebrospinal fluid (CSF) leaks were identified in 6 cases.

CONCLUSION

Blood supply to the nasal floor by the dominant inferior meatus branch is more robust than the supply to the anterior LNW by the superficial arterial branch. The LNW flap is the preferred vascularized reconstructive option to the PCF and sella in the absence of a nasoseptal flap (NSF).

[Modern aspects of surgical treatment of nasal liquorrhea with localization of defect in frontal sinus]

Defects localized in the frontal sinus are difficult for surgical treatment, since there is a large number of anatomical variations in the structure of the naso-frontal canal and the sinus itself. With the development of endoscopic technology and paying attention to the modern tendency of minimal invasive surgery, new invasive approaches to reach frontal sinus, such as endoscopic approach according to Draf I-III and combined approaches were developed and put into practice.

OBJECTIVE

To summarize and to analyze the results of treatment of nasal liquorrhea with localization of the defect in the frontal sinus using endoscopic endonasal and combined intra-extranasal approaches.

MATERIAL AND METHODS

A retrospective analysis of a series of 43 cases of nasal liquorrhea with a frontal sinus defect being treated at the NMRCN Burdenko during the period from 2001 to 2017. To select access, a classification of frontal sinus defects according to their localization was developed. The analysis of demographic and clinical data of patients, as well as intraoperative and postoperative data analysis were done.

RESULTS

In the series of 43 patients, endoscopic endonasal approach was performed in 28 (65%) cases. Combined approach was performed at 15 (35%) patients. The success rate of plastic surgery with endoscopic endonasal approach was 86% (24 of 28), with combined approach - 93% (14 of 15).

CONCLUSION

Endoscopic endonasal and combined approaches are the methods of choice for plastic surgery of defects of the skull base in the frontal sinus as they are effective and safe. The choice of approach depends on anatomical features of the frontal sinus and on the localization of defect.

Locating and Preserving the Sphenopalatine Ganglion in Endoscopic Endonasal Pterygopalatine Fossa Surgery: An Anatomical Study

Background

The pterygopalatine fossa (PPF) contains numerous important neurovascular structures; notably, the sphenopalatine ganglion (SPG), the maxillary branch of the trigeminal nerve (V2), and the internal maxillary artery. With the advent of extended endoscopic endonasal surgery, the surgical anatomy of the PPF warrants increased investigation. Intraoperative dissection and preservation of the SPG is essential to prevent postoperative xeropthalmia and facial hypoesthesia.

Objective

This study aims to (1) describe a novel dissection technique for identifying the SPG and (2) define the SPG location relative to the sphenopalatine foramen (SPF), which is a consistently identifiable landmark.

Methods

Eight cadaveric PPFs were dissected in step-wise fashion. An endoscopic medial maxillectomy was performed, the SPF was identified, and the posterior maxillary wall was resected. The maxillary branch of the trigeminal nerve (V2) was identified anterolaterally in its infraorbital canal and traced medially to identify the pterygopalatine nerve to the SPG. The lateral distance and superior/inferior distance from the SPG to the fixed SPF was measured.

Results

The surgical technique described allowed for reliable identification of the SPG. The SPG was located on average 4.5 ± 1.1 mm lateral and 1 ± 1.4 mm inferior to the SPF.

Conclusion

Identification and preservation of the SPG is necessary to prevent complications in endoscopic endonasal PPF surgery. The SPG can be reliably located near the SPF by following the pterygopalatine nerve branch of V2.

Endoscopic endonasal cyst fenestration into the sphenoid sinus using the mucosa coupling method for symptomatic Rathke's cleft cyst: a novel method for maintaining cyst drainage to prevent recurrence

OBJECTIVE

Rathke's cleft cyst (RCC) is a benign cystic lesion with a relatively high incidence of local recurrence that occasionally requires repeat surgery. To prevent recurrence, simple cyst fenestration and drainage of the cyst contents to the sphenoid sinus is recommended, but it occasionally recurs. The authors postulated that obstruction of fenestration is a main cause of recurrence, and they developed a method, named the "mucosa coupling method (MC method)," that maintains persistent drainage. In this method, the RCC epithelium and the mucosa of the sphenoid sinus are connected, which promotes re-epithelialization between the two epithelia, maintaining persistent drainage. The outcome of this method was compared with that of conventional cyst fenestration.

METHODS

In a consecutive series of 40 patients with RCC, the surgical strategy was changed during the study period: from December 2009 to September 2014 (the conventional period), 24 patients were scheduled to be treated using the conventional fenestration method, whereas from September 2014 to September 2017 (the MC period), 16 patients were scheduled to be treated using the MC method. However, because of an intraoperative CSF leak, the fenestration was closed during surgery in 3 patients in the conventional period and 2 in the MC period; therefore, these 5 patients were excluded from the analysis. Twenty-one patients treated with the conventional fenestration method (conventional group) and 14 patients treated with the MC method (MC group) were analyzed. All patients regularly underwent MRI after surgery to detect reaccumulation of cyst contents. The rate of reaccumulation with and without reoperation, visual outcomes, endocrinological outcomes, and postoperative complications were compared between these two groups.

RESULTS

The median follow-up period in all 35 patients was 48.0 months (range 1-96 months), 54.0 months (range 1-96 months) in the conventional group and 35.5 months (range 12-51 months) in the MC group. No reaccumulation was detected on MRI in the 14 patients in the MC group, whereas it was noted in 9 (42.9%) of 21 patients in the conventional group, and 2 of these 9 patients required repeat surgery. There were no significant differences in visual and endocrinological outcomes and complications between these two groups.

CONCLUSIONS

The MC method for RCC is effective for preventing obstruction of cyst fenestration, which contributes to preventing cyst reaccumulation. Furthermore, this method is equivalent to the conventional fenestration method in terms of visual and endocrinological outcomes and the complication rate.

Management of Noncatastrophic Internal Carotid Artery Injury in Endoscopic Skull Base Surgery

Arterial injuries are the most feared complication of endoscopic skull base surgery. During resection of the middle fossa component of a large ventral skull base chondrosarcoma, arterial bleeding was encountered near the right internal carotid artery (ICA). Durable hemostasis could not be achieved with packing and the patient was taken for an emergent angiogram that revealed a pseudoaneurysm of the proximal intradural ICA. Given the presence of good collateral flow through the anterior and posterior communicating arteries, the right ICA was sacrificed by coil embolization. The patient was taken back to the operating room for closure then transferred to the intensive care unit and maintained on vasopressors for five days to ensure adequate perfusion. The right ICA was coil embolized and the patient was taken back to the operating room for closure. The patient recovered without complication. Arterial injuries, although serious, are not always catastrophic. Critical steps are immediate recognition of bleeding, vascular imaging, and vessel sacrifice if necessary.

[Experience of treating patients with lateral sphenoid sinus recess CSF leak]

According to various authors, the rate of sphenoid sinus defects ranges from 15 to 26%. In the sphenoid sinus, the most common defect localization is the lateral recess - 35.3%. Regardless of the etiology and pathogenesis of lateral sphenoid sinus recess cerebrospinal fluid (CSF) leak, the treatment approach is aimed at plastic closure of the defect. Surgery in this area is associated with a high rate of recurrences (25%) due to a complex anatomical landscape and inapplicability of a direct approach.

PURPOSE

The study purpose was to analyze our own experience in treating patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess and, based on the obtained results, develop an algorithm for the treatment of this pathology.

MATERIAL AND METHODS

We retrospectively reviewed a series of 89 patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess who were treated at the Burdenko Neurosurgical Institute in the period between 2001 and 2017. The demographic characteristics of patients, clinical data, and aspects of surgical treatment were analyzed. Treatment outcomes were assessed based on analysis of recurrences and postoperative complications. The obtained data were compared to the literature data.

RESULTS

In the series of 89 patients with CSF leak and meningoencephalocele in the lateral sphenoid sinus recess, the mean age was 49 years. Surgery through the transsphenoid approach was performed in 89 (74%) patients. There were 25 (28%) recurrences in this group. Nine (7%) patients underwent repair of a complex skull base defect using the transethmoidal approach; there were 3 (33%) recurrences. The transpterygoid approach was used in 22 (17%) patients; there were 3 (14%) recurrences in this group.

CONCLUSION

Endoscopic endonasal repair is an effective technique for treating complex skull base defects in the lateral sphenoid sinus recess. The choice of an approach to the defect depends on the degree of pneumatization of the sphenoid sinus, surgeon's experience, and availability of the necessary equipment and tools. The endoscopic transpterygoid approach is advisable to use in cases of excessive pneumatisation of the sinus with developed lateral processes and recurrent nasal CSF leak. This enables visualization of the defect edges in this hard-to-reach area and adequate repair.

[Management of complex skull base defects accompanied by pneumocephalus]

AIM

The study aim was to analyze our own experience in treating patients with complex skull base defects accompanied by pneumocephalus and, based on the findings, to develop an optimal treatment approach for this pathology.

MATERIAL AND METHODS

We retrospectively reviewed a series of 30 patients with complex skull base defects accompanied by pneumocephalus who underwent inpatient treatment at the Burdenko Neurosurgical Institute in the period from 2001 to 2017. We analyzed demographic characteristics of patients (gender, age), clinical data (etiology, somatic and neuropsychiatric status, radiological data), and treatment aspects (conservative or surgical treatment, used approach, defect characteristics, reconstructive materials). Treatment outcomes were assessed based on analysis of changes in clinical manifestations, postoperative complications, and recurrences. The obtained data were compared to the results of literature review.

RESULTS

In the series of 30 patients with complex skull base defects accompanied by pneumocephalus, the mean age was 41 years (range, 17-68 years); there were 17 (59%) males and 13 (41%) females. Etiologically, there were 17 (59%) traumatic cases, 11 (36%) iatrogenic cases, and 2 (5%) spontaneous cases. Clinically, the patients presented with the following manifestations: psycho-neurological symptoms (41%), nasal cerebrospinal fluid (CSF) leak (36%), impaired consciousness (27%), and meningitis (23%). Eight patients with acute injuries underwent complex conservative treatment that included infusion, and anti-edema, vascular, metabolic, anticonvulsant, and antibacterial therapy. In cases of conservative treatment failure or tension pneumocephalus accompanied by abrupt worsening of the patient's condition, surgical treatment was used. A total of 24 interventions (including revision surgery) were performed in 22 patients. All patients underwent endoscopic endonasal reconstruction of complex skull base defects. Tissues used for reconstruction included the fascia lata and adipose tissue (77%), fascia lata and cartilage/bone from the nasal septum (14%), and a pedicled nasoseptal flap (9%). The success rate of reconstructive interventions was 91%. There were 2 (9%) recurrences. Postoperative complications in the form of meningitis occurred in 4 (18%) patients.

CONCLUSION

In the case of a nasal cerebrospinal leak history and worsening of the patient's condition accompanied by common cerebral and psychiatric symptoms, the development of pneumocephalus should be considered first, the early diagnosis of which will facilitate choosing the correct treatment approach. In the case of acute injury in patients with the established diagnosis of pneumocephalus caused by gas-forming infection, conservative therapy is indicated in the early period after neurosurgical interventions with opening of the meninges. Tension pneumocephalus together with a skull base bone defect (according to CT) and a nasal CSF leak history is the indication for surgical treatment. In this case, the endoscopic endonasal technique is the method of choice.

[Nasal schwannoma with skull base destruction in a child (a case report and literature review)]

Schwannomas (neurinomas) are benign, encapsulated, and slow-growing neoplasms developing from any peripheral, cranial, or vegetative nerve that has the Schwann sheath. Schwannomas of the nasal cavity and paranasal sinuses in adults occur rarely, less than 4% of cases. The world literature lacks similar data for the pediatric age group because these tumors in children are unique and extremely rare. The most common clinical symptoms of sinonasal schwannoma are nasal breathing disorders, hyposmia or anosmia, and snoring at night. Other symptoms are associated with intranasal schwannoma invasion of neighboring organs and tissues and include exophthalmos, epiphora (lacrimation), headaches, and anesthesia in the facial area. In this article, we describe a rare case of diagnosis and successful surgical treatment of a child with intranasal schwannoma destructing the skull base.

Sellar Diaphragm Reconstruction with Tachosil During Endoscopic Endonasal Surgery: Technical Note

This report introduces a new closure technique for the management of intraoperative cerebrospinal fluid (CSF) leakage during endoscopic endonasal surgery. The procedure is based on the combination of a traditional autologous tissue flap with a heterologous fibrin graft (TachoSil). We performed a retrospective analysis on 121 patients with pituitary adenomas treated in our center by the senior neurosurgeon (author V.R.B) in the previous 4 years. Only one patient (0.8%) developed a CSF leakage and no adverse events were found related to the use of TachoSil. Compared with other techniques used previously, sellar diaphragm reconstruction with TachoSil seems to be an effective and inexpensive alternative.

Multidisciplinary treatment algorithm for the management of sinonasal cancers with orbital invasion: A retrospective study

BACKGROUND

Sinonasal cancers frequently involve the orbit with resulting controversies on whether to remove or preserve the orbital contents.

METHODS

Retrospective review of patients with primary sinonasal cancer involving the orbit, treated according to a multidisciplinary protocol tailored to tumor histology and extent of orbital invasion in two tertiary care referral centers over a 20-year period.

RESULTS

The oncological and functional outcomes of 163 patients were analyzed. The degree of orbital involvement significantly affected both overall (P < .0001) and disease-free (P < .0001) survival. Orbital apex invasion was an independent negative prognostic factor (5-year overall survival, 14.6% ± 7.5%), with dismal prognosis regardless of the treatment adopted. An appropriate use of induction chemotherapy and endoscopic-assisted surgery allowed for orbital preservation in 76.6% of cases; 96% of patients treated using an orbit-sparing approach maintained a functional eye after treatment.

CONCLUSION

The multimodal treatment algorithm herein proposed was able to maximize orbital preservation rates with acceptable oncological and functional outcomes.

Validation of training levels in endoscopic endonasal surgery of the skull base

OBJECTIVE

A five-level training program was first proposed 10 years ago for surgeons learning endoscopic endonasal surgery (EES) of the skull base. Levels were based on the complexity of anatomy, risk of neurovascular injury, intradural dissection, technical difficulty and vascularity of tumors.

METHOD

A three-phase validation concept is proposed: 1) face validity (the classification is related to clinically significant elements), 2) construct validity (the classification predicts the outcome), and 3) inter-team validation (the classification applies to other surgical teams). Consecutive cases over a 1-year time span were retrospectively classified. Primary outcome measures included: complication rates (cranial nerve injury, stroke and vascular injury, cerebrospinal fluid [CSF] leak and infection), estimated blood loss and duration of surgery.

RESULTS

Two hundred and nine consecutive cases were analyzed. The distribution of cases for each category was: 63 cases in level II, 70 cases in level III, 66 cases in level IV, and 10 cases in level V. Construct validity demonstrated statistical difference with increasing rate of complications from level II to level III and from level III to level IV; also, specific rates of cranial nerve injury and CSF leak increased between levels III and IV. Face validity identified 162 citations since publication of the original article. Inter-team validation demonstrated no difference between two teams of surgeons.

CONCLUSION

This study provides a three-phase validation of training levels for endoscopic skull base surgery. Adoption of a progressive systematic approach to learning EES from least complex to advanced procedures is expected to minimize the risks while surgical teams gain experience.

LEVEL OF EVIDENCE

3 Laryngoscope, 129:2253-2257, 2019.

Development and validation of a multi-color model using 3-dimensional printing technology for endoscopic endonasal surgical training

BACKGROUND

The teaching of endoscopic endonasal surgery has always been difficult because of the complex structure of the nasal cavity, and the unique endoscopic view angle and endoscopic surgical tools. In this study, we have designed a 3D printed multi-color model for training of endoscopic endonasal surgery, and obtained preliminary application results.

METHODS

The 3D printed model contained facial skin, bony skeleton, internal carotid artery, turbinate, optic chiasm, and a special sellar base with appropriate colors. After it was printed, six otolaryngologists and neurosurgeons assessed the model. Twenty graduate students and residents from otolaryngology or neurosurgery, without prior experience in endoscopic endonasal surgery were recruited and consented for the training. The training results were recorded. The subjective feeling of participants in terms of using 3D printed model in surgical training was investigated after training.

RESULTS

All experts strongly agreed or agreed that the 3D printed model has realistic anatomical structure of nasal passage and appropriate colors for different parts, and is a good teaching tool. As the trainees practiced more, the rate and quality of endoscopic operation increased gradually. Compared to the first practice, all recorded training parameters were improved significantly (all P < 0.05). All participants strongly agreed or agreed that they benefited from the training and the 3D printed model can inspire interest and enthusiasm of endoscopic endonasal surgical training.

CONCLUSION

This 3D printed model has realistic anatomical structure of nasal passage and appropriate colors for different parts, and could be a good teaching tool of endoscopic endonasal surgery.

Intractable Rathke's cleft cyst hidden behind co-existing giant pituitary adenoma - Case report

BACKGROUND

Although pituitary adenoma (PA) and Rathke's cleft cyst (RCC) share a common embryological origin, concurrent appearances have rarely been reported. We present a case of intractable RCC hidden behind a co-existing giant PA.

CASE DESCRIPTION

A 39-year-old female visited an ophthalmologist with visual disturbance. Brain MRI findings showed a giant mass in the intra- and supra-sellar portion, with a cystic portion contained in the posterior part. Endoscopic endonasal surgery was performed to remove the tumor and histopathology findings revealed a non-functioning pituitary adenoma. Furthermore, another brain MRI procedure showed the appearance of a residual cyst. A second endonasal endoscopic surgery was performed to decompress the growing cyst for the optic chiasma, with cyst drainage and irrigation performed, and portions of the cyst walls obtained. The histopathological diagnosis was RCC with inflammation. Over the course of 1 year, 3 separate recurrences of the growing cyst were noted, with cyst drainage and irrigation performed each time. Finally, ethanol cauterization was used, which stopped the symptomatic RCC recurrence. Eight years after the final procedure, there was no cyst recurrence, and the patient showed a good condition with improved visual acuity and normal pituitary function.

CONCLUSIONS

The presence of a non-enhanced cyst with a PA shown by MRI suggests the possibility of coexisting RCC and PA.

Respiratory epithelial adenomatoid hamartoma - typical but underdiagnosed pathology of nasal cavity and sinuses

Respiratory epithelial adenomatoid hamartoma (REAH) is relatively new diagnosis, firstly described in WHO tumour classification in 2005. It is a benign lesion affecting nose and paranasal sinuses. Although REAH was considered a rare entity, it is recently more frequently revealed in histopathological exam in patients undergoing endoscopic surgery for nasal polyposis. There have been so far operated two patients with diagnosis of REAH in our department. Both were solitary lesions, and both were resected endoscopically. Definitive histopathological examination confirmed the finding of preoperative biopsy under local anesthesia. No recurrent disease has been observed. Considering quite frequent occurrence of REAH in patients with nasal polyposis and low awareness of the disease itself among ENT specialists, pathologists and radiologists it is still relatively underdiagnosed lesion. The possibility of misdiagnosis and confusion with other more serious diseases like inverted papilloma or low-grade adenocarcinoma is of clinical importance. It may lead to overtreatment and too aggressive surgical therapy.

Recurrence Rate after Endoscopic vs. Open Approaches for Juvenile Nasopharyngeal Angiofibroma: A Meta-analysis

Context  The effect on recurrence rate between patients with juvenile nasopharyngeal angiofibroma (JNA), treated by an endoscopic versus open approach, has not been well established. Objective  A meta-analysis of the available literature concerning recurrence rate in patients who underwent surgery for JNA. Methods  A retrospective meta-analysis of studies analyzing recurrence rate after endoscopic or open surgery for patients with JNA was performed using the DerSimonian-Laird random-effects method. English and non-English articles were reviewed using Embase, Medline, and Cochrane databases. Results  Among nine studies, including 362 patients from 1981 to 2015, with a mean follow-up of 49.4 months, a total of 89 patients (24.5%) had recurrence. Our analysis revealed a total effect size of -0.16 in favor of endoscopic approach (-0.25 to -0.06, CI [confidence interval] 95%). When analyzing tumor by stage (Radkowski's IA-IIIB n  = 299), the endoscopic approach proved to be superior independent of tumor stage (2 vs. 17% for tumors stage IA-IIA, and 26 vs. 32% for tumor stage IIB-IIIB for endoscopic and open approaches respectively; p  < 0.05). The endoscopic approach has a statistical significant lower recurrence rate in patients without intracranial compromise when compared with the open approach (13 vs. 28%; p  < 0.02). No statistical difference was seen in patients with intracranial compromise ( p  = 0.5) Conclusion  The use of an endoscopic approach to treat JNA has a significantly lower recurrence rate when compared with open approaches. Independent of disease stage, an endoscopic approach should be the standard of care to surgically treat JNA. For cases with intracranial compromise, either approach can be used for surgical resection.

Endoscopic Endonasal Surgery for the Resection of a Cavernous Hemangioma with a Sellar Extension

Cavernous hemangiomas with an intrasellar extension are very rare, generally benign lesions that manifest by the compression of nearby structures. The presenting symptoms usually range from visual disturbances to an endocrine imbalance. Occasional extension into the cavernous sinus has been reported, which can cause cranial nerve compression. We present the case of a 69-year-old man presenting with facial pain and decreased libido. On investigation, a lesion was identified and the parasellar region was homogeneously hyper-intense on gadolinium-enhanced magnetic resonance imaging (MRI). Endoscopic endonasal surgery remains one of the favored approaches for the resection of sellar lesions. Such pathology needs to remain on the neurosurgeon’s differential diagnosis, making an intraoperative frozen section of these lesions a useful tool in the surgeon's armamentarium, to guide further surgical resection.

The Endoscopic Endonasal Management of Anterior Skull Base Meningiomas

Introduction  The endoscopic endonasal approach (EEA) might seem an "unnatural" route for intradural lesions such as meningiomas. The aim of this study is to critically revise our management of anterior skull base meningiomas to consider, in what cases it may be advantageous. Material and Methods  Each consecutive case of anterior skull base meningioma operated on through an EEA or combined endoscopic-transcranial approach at our institution, between 2003 and 2017, have been included. Tumors were classified on the basis of their location and intra or extracranial extension. Follow-up consisted of an MRI (magnetic resonance imaging) and a clinical examination 3 months after the surgery and then repeated annually. Results  Fifty-seven patients were included. The most common location was the tuberculum sellae (62%), followed by olfactory groove (14%), planum sphenoidale (12%), and frontal sinus (12%). Among these, 65% were intracranial, 7% were extracranial, and 28% both intra and extracranial. Radical removal was achieved in 44 cases (77%). Complications consisted in 10 CSF (cerebrospinal fluid) leaks (17.6%), 1 overpacking (1.7%), and 1 asymptomatic brain ischemia (1.7%). Visual acuity and campimetric deficits improved respectively in 67 and 76% of patients. Recurrence rate was of 14%. Conclusions  EEA presents many advantages in selected cases of anterior skull base meningioma. However, it is hampered by the relevant risk of CSF leak. We consider that it could be advantageous for planum/tuberculum sellae tumors. Conversely, for olfactory groove or frontal sinus meningiomas, it can be indicated for tumors with extracranial extension, while its role is still debatable for purely intracranial forms as considering our surgical results, it could be advantageous for midline planum/tuberculum sellae tumors. Conversely, it can be of first choice for olfactory groove or frontal sinus meningiomas with extracranial extension, while its role for purely intracranial forms is still debatable.

The Difficult Airway after Endoscopic Endonasal Skull Base Surgery: A Case Series and Management Algorithm

OBJECTIVES

To analyze difficult airway situations affecting patients after endoscopic endonasal surgery (EES) for skull base tumors and to develop an airway management algorithm.

STUDY DESIGN

Case series with chart review.

SETTING

Single tertiary care center.

SUBJECTS AND METHODS

Eleven difficult airway events occurred among patients after EES for skull base tumors, as identified through a retrospective review of our institutional Difficult Airway Management Team registry from January 2008 to March 2016. Data from these events included patient demographics, event characteristics, airway management techniques, and outcomes. Results were used to design a difficult airway protocol.

RESULTS

The majority of patients were obese (63.6%) and had a dural defect (90.9%), each of which was repaired with a vascularized flap. The most common reasons for the difficult airway call were concern for using mask ventilation in a patient with a dural defect (27.3%) and difficult airway anatomy (27.3%). Two patients did not require airway intervention; 8 were intubated; and 1 underwent cricothyroidotomy. Videolaryngoscopy was the most common first-attempt intubation technique, followed by conventional direct laryngoscopy. Effective adjunctive techniques included intubation through a laryngeal mask airway and bougie-guided intubation. As compared with simple mask ventilation, laryngeal mask airway-assisted ventilation was associated with a decreased incidence of postevent cerebrospinal fluid leak. There were no incidences of postevent pneumocephalus, cardiopulmonary arrest, or mortality.

CONCLUSIONS

We propose a difficult airway algorithm for patients following EES of the skull base, with sequential recommendations for airway management methods and commentary on adjunctive techniques.

Large cell neuroendocrine carcinoma of the nasal cavity: an extremely rare and new distinct entity

Large cell neuroendocrine carcinoma (LCNEC) is a rare but distinct entity of nasal cavity carcinomas. Only a very few cases have been reported in the nasal cavity. Its treatment is not well established. We report the case of a LCNEC in a 70 years old patient who presented with right nasal obstruction and epistaxis since 2 months. Diagnosis was confirmed by histological and immunohistochemical study. The patient underwent complete endoscopic removal of the tumor combined to adjuvant chemoradiotherapy. After 6 month follow-up, the patient was in complete clinical and radiological remission. We will discuss in this paper the various epidemiology, clinical features, pathological findings, differential diagnosis, and evolution of treatment of this uncommon malignancy in the light of current knowledge. Optimal treatment strategies are yet to be determined for this rare malignancy with poor prognosis including surgery and chemoradiotherapy.

Endoscopic Endonasal Surgery for Subdiaphragmatic Type Craniopharyngiomas

Subdiaphragmatic type craniopharyngiomas are tumors that originate within the sella. They are divided into two types; those localized within an enlarged sella (intrasellar type) and those accompanying a suprasellar extension (suprasellar extended type). The clinicopathological features and the recent outcomes of endoscopic endonasal surgery were retrospectively reviewed in 32 patients, with 11 surgeries for recurrence. These tumors showed a preponderance in young patients (19 patients were younger than 18-year-old) and suprasellar extended type (25 cases), were mostly composed of a large cyst (96.9%) and were frequently adamantinomatous type (68.8%). Combined transcranial-endoscopic endonasal surgery was applied in three patients with extremely large tumors and significant frontal extension. Total tumor resection and stalk preservation were achieved in 26 and 17 patients, respectively. No complications developed after surgery apart from pituitary dysfunction and visual deterioration. 5 of 6 patients with subtotal tumor resection and 6 of 7 patients with no improvement or deterioration of visual function were in the recurrent cases. Although this type is basically an extraarachnoidal tumor, the suprasellar portion of the tumor showed adherence to important tissues in some patients with recurrence. Pituitary function remained normal in only one third of patients with stalk preservation. To avoid pituitary dysfunction after surgery, sharp excision of firm adherence to the stalk should be considered in some patients.

Endoscopic Endonasal Approach for Complex Macroadenoma with Suprasellar and Retrochiasmatic Extension

In this video, we describe the technical nuances of an endoscopic endonasal approach (EEA) for a complex macroadenoma with suprasellar and retrochiasmatic extension. The patient is a 51-year-old male with several years' history of progressive visual loss. Neuro-ophthalmology assessment revealed a profound visual loss with homonymous hemianopsia and left optic nerve atrophy. His pituitary hormonal profile was normal. The options for surgical approach included transcranial, endoscopic endonasal, or a combination of both. An EEA was the preferred surgical option, because it allows for early identification of the pituitary gland, and provides access to the suprasellar region including pre- and retrochiasmatic spaces, which facilitates tumor removal while minimizing manipulation of the optic apparatus. While most pituitary adenomas do not require extracapsular subarachnoidal dissection, there are complex adenomas with subarachnoidal invasion and multilobulated morphology, such as the one presented here, that require a combination of internal debulking, extracapsular and subarachnoidal dissection. The technique presented here allows for complete tumor resection, avoiding the risk of postoperative apoplexy of residual adenoma, and facilitates identification of perforating branches and neural structures that require meticulous preservation. Here, we also illustrate the proper management of reconstruction-related complications. Postoperative course was complicated with meningitis with necrotic nasoseptal flap and required surgical debridement, new inferior turbinate flap, fascia lata, lumbar drain, and 6-week antibiotic treatment. Imaging follow-up showed complete removal of tumor. The patient had significant improvement in visual fields and left visual acuity, and no postoperative hormonal dysfunction.

The link to the video can be found at: https://youtu.be/9T5b167bVJA .

Universal Sellar Anatomical Reconstruction Using the Sellar Floor Flap after Endoscopic Pituitary Adenoma Surgery

Postoperative cerebrospinal fluid (CSF) leaks still occur in patients without intraoperative CSF leaks after endoscopic endonasal pituitary adenoma surgery. We propose a reconstructive technique, the sellar floor flap (SFF), for universal sellar anatomical reconstruction. A total of 113 patients without intraoperative CSF leaks after endoscopic endonasal pituitary adenoma surgery from July 2013 to June 2016 were reviewed: 43 underwent sellar reconstruction with the SFF (the SFF group) and 70 underwent sellar packing only (the nonreconstruction group). No case of postoperative CSF leak was reported in the SFF group, whereas 7 cases were reported in the nonreconstruction group ( P < .05). The SFF is suitable for universal reconstruction after endoscopic endonasal pituitary adenoma surgery and may decrease postoperative CSF leak.

Fibro-Osseous Lesions of the Skull Base in the Pediatric Population

Fibro-osseous lesions of the skull base include a variety of lesions with different biologic behavior. The most common lesions include fibrous dysplasia, osteoma, aneurysmal bone cyst, and juvenile ossifying fibroma. The diagnosis can usually be established with radiographic imaging. In the absence of symptoms, slow-growing lesions can often be observed. When surgery is indicated for relief of symptoms, endoscopic endonasal techniques are well suited for all age groups.

Early Stage olfactory neuroblastoma and the impact of resecting dura and olfactory bulb

OBJECTIVE

Compare outcomes of patients with olfactory neuroblastoma (ONB) without skull base involvement treated with and without resection of the dura and olfactory bulb.

METHODS

Retrospective review of ONB patients treated from 1992 to 2013 at the MD Anderson Cancer Center (The University of Texas, Houston, Texas, U.S.A.). Primary outcomes were overall and disease-free survival.

RESULTS

Thirty-five patients were identified. Most patients had Kadish A/B. tumors (97%), Hyams grade 2 (70%), with unilateral involvement (91%), and arising from the nasal cavity (68%). Tumor involved the mucosa abutting the skull base in 42% of patients. Twenty-five patients (71%) received surgery and radiation, whereas the remainder had surgery alone. Five patients (14%) had bony skull base resection, and eight patients (23%) had resection of bony skull base, dura, and olfactory bulb. Surgical margins were grossly positive in one patient (3%) and microscopically positive in four patients (12%). The 5- and 10-year overall survival were 93% and 81%, respectively. The 5- and 10-year disease-free survival (DFS) were 89% and 78%, respectively. Bony cribriform plate resection was associated with better DFS (P = 0.05), but dura and olfactory bulb resection was not (P = 0.11). There was a trend toward improved DFS in patients with negative resection margins (P = 0.19). Surgical modality (open vs. endoscopic) and postoperative radiotherapy did not impact DFS.

CONCLUSION

Most Kadish A/B ONB tumors have low Hyams grade, unilateral involvement, and favorable survival outcomes. Resection of the dura and olfactory bulb is not oncologically advantageous in patients without skull base involvement who are surgically treated with negative resection margins and cribriform resection.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:1274-1280, 2018.

Is the chiasm-pituitary corridor size important for achieving gross-total resection during endonasal endoscopic resection of craniopharyngiomas?

OBJECTIVE Craniopharyngiomas arise from the pituitary stalk, and in adults they are generally located posterior to the chiasm extending up into the third ventricle. The extended endonasal approach (EEA) can provide an ideal corridor between the bottom of the optic chiasm and the top of the pituitary gland (chiasm-pituitary corridor [CPC]) for their removal. A narrow CPC in patients with a prefixed chiasm and a large tumor extending up and behind the chiasm has been considered a contraindication to EEA, with a high risk of visual deterioration and subtotal resection. METHODS A database of all patients treated in the authors' center (Weill Cornell Medical College, NewYork-Presbyterian Hospital) between July 2004 and August 2016 was reviewed. Patients with craniopharyngiomas who underwent EEA with the goal of gross-total resection (GTR) were included in the study. Patients with postfixed chiasm or limited available preoperative imaging were excluded. Using preoperative contrast-enhanced T1-weighted sagittal midline MR images, the authors calculated the CPC as well as the distance from the chiasm to the top of the tumor (CTOT). From these numbers, they calculated a ratio of the CPC to the CTOT as a measure of difficulty in removing the tumors through the EEA and called this ratio the corridor index (CI). The relationship between the CI and the ability to achieve GTR and visual outcome were measured. RESULTS Thirty-four patients were included in the study. The mean CPC was 10.1 mm (range 5.2-19.1 mm). The mean CTOT was 12.8 mm (range 0-28.3 mm). The median CI was 0.8; the CI ranged from 0.4 to infinity (for tumors with a CTOT of 0). Thirty-two patients had GTR (94.1%) and 2 had subtotal resection. The CPC value had no relationship with our ability to achieve GTR and no effect on visual or endocrine outcome. CONCLUSIONS EEA for craniopharyngioma is generally considered the first-line surgical approach. Although a narrow corridor between the top of the pituitary gland and the bottom of the chiasm may seem to be a relative contraindication to surgery for larger tumors, the authors' data do not bear this out. EEA appears to be a successful technique for the majority of midline craniopharyngiomas.

Suprasellar and third ventricular cavernous malformation: Lessons learned in differential diagnosis and surgical planning

Background:

While craniopharyngiomas (CPs) are the most common cystic suprasellar lesions in adults, cavernous malformations (CMs) only exceptionally occur in this location and are seldom considered in the differential diagnosis of such lesions. However, unlike CPs, suprasellar CMs are not typically approached via an endoscopic endonasal approach.

Case Description:

We present a unique clinical case of suprasellar and third ventricular CM mimicking a CP, posing a major decision-making dilemma at the levels of both preoperative diagnosis and surgical planning.

Conclusion:

This case highlights the importance of carefully considering all the differential diagnoses of sellar pathology to select the most appropriate management strategy and surgical approach.

Endoscopic endonasal surgery for pituitary adenomas extending to the oculomotor cistern

BACKGROUND

Extension of a pituitary adenoma to the oculomotor cistern harbors the risk of oculomotor nerve impairment and further extension into the interpeduncular cistern. The role of endoscopic endonasal surgery for those lesions was investigated.

METHODS

The medical records were retrospectively analyzed. Attention was paid to the oculomotor nerve function and removal rate of the tumor within the oculomotor and interpeduncular cisterns.

RESULTS

Six patients were eligible for the study, including 2 with oculomotor nerve palsy. The tumor from the oculomotor and interpeduncular cistern was removed in all except on one side of the case with bilateral tumor extension. The oculomotor nerve palsy demonstrated partial recovery in both cases during the 3-month follow-up.

CONCLUSION

The pituitary adenoma extending to the oculomotor cistern can be removed under the endoscope. Improvement of oculomotor nerve palsy can be achieved, and further tumor extension into the interpeduncular cistern can be prevented.

Contralateral transmaxillary corridor: an augmented endoscopic approach to the petrous apex

OBJECTIVE The endoscopic endonasal approach (EEA) has been shown to be an effective means of accessing lesions of the petrous apex. Lesions that are lateral to the paraclival segment of the internal carotid artery (ICA) require lateralization of the paraclival segment of the ICA or a transpterygoid infrapetrous approach. In this study the authors studied the feasibility of adding a contralateral transmaxillary (CTM) corridor to provide greater access to the petrous apex with decreased need for manipulation of the ICA. METHODS Using image guidance, EEA and CTM extension were performed bilaterally on 5 cadavers. The anterior wall of the sphenoid sinus and rostrum were removed. The angle of the surgical approach from the axis of the petrous segment of the ICA was measured. Five illustrative clinical cases are presented. RESULTS The CTM corridor required a partial medial maxillectomy. When measured from the axis of the petrous ICA, the CTM corridor decreased the angle from 44.8° ± 2.78° to 20.1° ± 4.31°, a decrease of 24.7° ± 2.58°. Drilling through the CTM corridor allowed the drill to reach lateral aspects of the petrous apex that would have required lateralization of the ICA or would not have been accessible via EEA. The CTM corridor allowed us to achieve gross-total resection of the petrous apex region in 5 clinical cases with significant paraclival extension. CONCLUSIONS The CTM corridor is a feasible extension to the standard EEA to the petrous apex that offers a more lateral trajectory with improved access. This approach may reduce the risk and morbidity associated with manipulation of the paraclival ICA.

Training model for control of an internal carotid artery injury during transsphenoidal surgery

OBJECTIVES

As the adoption of endoscopic endonasal approaches (EEA) continues to proliferate, increasing numbers of internal carotid artery (ICA) injuries are reported. The objective of this study was to develop a synthetic ICA injury-training model that could mimic this clinical scenario and be portable, repeatable, reproducible, and without risk of biological contamination.

METHODS

Based on computed tomography of a human head, we constructed a synthetic model using selective laser sintering with polyamide nylon and glass beads. Subsequently, the model was connected to a pulsatile pump using 6-mm silicon tubing. The pump maintains a pulsatile flow of an artificial blood-like fluid at a variable pressure to simulate heart beats. Volunteer surgeons with different levels of training and experience were provided simulation training sessions with the models. Pre- and posttraining questionnaires were completed by each of the participants.

RESULTS

Pre- and posttraining questionnaires suggest that repeated simulation sessions improve the surgical skills and self-confidence of trainees.

CONCLUSION

This ICA injury model is portable; reproducible; and avoids ethical, biohazard, religious, and legal problems associated with cadaveric models. A synthetic ICA injury model for EEA allows recurring training that may improve the surgeon's ability to maintain endoscopic visualization, control catastrophic bleeding, decrease psychomotor stress, and develop effective team strategies to achieve hemostasis.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:38-43, 2017.

Sphenoid sinus organized hematoma with cranial neuropathies masquerading as a malignancy: A case report

Sinonasal organized hematoma (SNOH) is rarely encountered in clinical practice. The disease demonstrates a high tendency for occurrence in East Asian individuals, and in the majority of cases, is located in the maxillary sinus. The current report presents the case of an 81-year-old female who developed a space-occupying lesion, which masqueraded as a skull base malignancy, following surgery for the treatment of isolated sphenoid sinus aspergilloma. Subsequent endoscopic endonasal surgery confirmed the diagnosis of an OH of the sphenoid sinus. The patient recovered from all neurological deficits within two months, with the exception of the loss of visual perception. Although SNOH presents a diagnostic challenge, when physicians possess knowledge of its typical imaging features, this facilitates the achievement of a correct diagnosis and the prescription of optimal treatment.

Intraoperative neurophysiological monitoring during endoscopic endonasal surgery for pediatric skull base tumors

OBJECT The aim of this study was to evaluate the value of intraoperative neurophysiological monitoring (IONM) using electromyography (EMG), brainstem auditory evoked potentials (BAEPs), and somatosensory evoked potentials (SSEPs) to predict and/or prevent postoperative neurological deficits in pediatric patients undergoing endoscopic endonasal surgery (EES) for skull base tumors. METHODS All consecutive pediatric patients with skull base tumors who underwent EES with at least 1 modality of IONM (BAEP, SSEP, and/or EMG) at our institution between 1999 and 2013 were retrospectively reviewed. Staged procedures and repeat procedures were identified and analyzed separately. To evaluate the diagnostic accuracy of significant free-run EMG activity, the prevalence of cranial nerve (CN) deficits and the sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS A total of 129 patients underwent 159 procedures; 6 patients had a total of 9 CN deficits. The incidences of CN deficits based on the total number of nerves monitored in the groups with and without significant free-run EMG activity were 9% and 1.5%, respectively. The incidences of CN deficits in the groups with 1 staged and more than 1 staged EES were 1.5% and 29%, respectively. The sensitivity, specificity, and negative predictive values (with 95% confidence intervals) of significant EMG to detect CN deficits in repeat procedures were 0.55 (0.22-0.84), 0.86 (0.79-0.9), and 0.97 (0.92-0.99), respectively. Two patients had significant changes in their BAEPs that were reversible with an increase in mean arterial pressure. CONCLUSIONS IONM can be applied effectively and reliably during EES in children. EMG monitoring is specific for detecting CN deficits and can be an effective guide for dissecting these procedures. Triggered EMG should be elicited intraoperatively to check the integrity of the CNs during and after tumor resection. Given the anatomical complexity of pediatric EES and the unique challenges encountered, multimodal IONM can be a valuable adjunct to these procedures.

ACTH adenomas transforming their clinical expression: report of 5 cases

OBJECT Adrenocorticotropic hormone (ACTH) adenomas have been recognized as a more aggressive and invasive subtype of pituitary adenomas. An additional and clinically relevant peculiarity of these tumors is their ability to modify their clinical expression from a silent form to Cushing disease or vice versa. The aim of this study was to review a series of patients with pituitary adenomas and analyze the clinical implications of the transformation of clinical expression in 5 cases that showed this phenomenon. METHODS The authors retrospectively reviewed a series of patients with pituitary adenoma and collected clinical, biohumoral, and neuroradiological data of those who presented with a transformation from silent ACTH adenomas to functioning tumors or vice versa. In all the cases, preoperative assessment consisted of brain MRI, ophthalmological examination, and complete baseline endocrinological investigation. In patients with clinical and/or biochemical findings suspicious for Cushing syndrome, a low-dose dexamethasone suppression test was performed to rule in or out this diagnosis. Endocrinological evaluations were repeated 1 month after surgery, 3 months after surgery, and every 6 months or annually thereafter. Ophthalmological evaluations and brain MRIs were repeated after 3 months and then every 6 or 12 months thereafter. RESULTS Five patients (2 men and 3 women) included in this series had corticotropic tumors that showed transformation from an endocrinologically silent form to manifest Cushing disease and vice versa. The mean age at presentation was 40 years (range 18-51 years). In 3 of these patients, a transformation from silent to functioning ACTH adenoma with manifest Cushing disease occurred. In 1 patient, the authors observed the transition from a functioning to a silent adenoma with spontaneous resolution of hypercortisolism. Another patient's silent adenoma "shifted" to a functioning adenoma and then regressed back to a silent form with spontaneous resolution of Cushing disease. This patient again developed hypercortisolism, which finally resolved spontaneously. In this series, the transformation occurred after a mean of 3.5 years (range 6 months to 7 years). The shift from an ACTH-silent to a functioning adenoma was observed in 9% of the ACTH-silent adenomas in this series (4 of 44 cases), and the spontaneous remission of Cushing disease to a silent corticotroph cell adenoma occurred in 1.5% of cases of this series (2 of 132 functioning ACTH adenomas). At follow-up (mean 107 months; range 60-177 months), cortisol levels were within normal limits in all 5 cases. However, 1 patient required Gamma Knife radiosurgery and eventually adrenalectomy for disease control to be achieved. CONCLUSIONS The ability of silent ACTH adenomas to transform their secretion pattern poses a challenge for neurosurgeons and endocrinologists. Because the transformation is often unexpected, the clinical and biochemical data can be underestimated. Furthermore, this bizarre and unpredictable postoperative tumor behavior can lead to misinterpretation of clinical and endocrinological outcomes. Even if these cases are very rare, they are not anecdotal in large series. Thus, ACTH adenomas require careful biohumoral and neuroradiological follow-up to detect possible transformations.

The expanding role of the endonasal endoscopic approach in pituitary and skull base surgery: A 2014 perspective

BACKGROUND

The past two decades have been the setting for remarkable advancement in endonasal endoscopic neurosurgery. Refinements in camera definition, surgical instrumentation, navigation, and surgical technique, including the dual surgeon team, have facilitated purely endonasal endoscopic approaches to the majority of the midline skull base that were previously difficult to access through the transsphenoidal microscopic approach.

METHODS

This review article looks at many of the articles from 2011 to 2014 citing endonasal endoscopic surgery with regard to approaches and reconstructive techniques, pathologies treated and outcomes, and new technologies under consideration.

RESULTS

Refinements in approach and closure techniques have reduced the risk of cerebrospinal fluid leak and infection. This has allowed surgeons to more aggressively treat a variety of pathologies. Four main pathologies with outcomes after treatment were identified for discussion: pituitary adenomas, craniopharyngiomas, anterior skull base meningiomas, and chordomas. Within all four of these tumor types, articles have demonstrated the efficacy, and in certain cases, the advantages over more traditional microscope-based techniques, of the endonasal endoscopic technique.

CONCLUSIONS

The endonasal endoscopic approach is a necessary tool in the modern skull base surgeon's armamentarium. Its efficacy for treatment of a wide variety of skull base pathologies has been repeatedly demonstrated. In the experienced surgeon's hands, this technique may offer the advantage of greater tumor removal with reduced overall complications over traditional craniotomies for select tumor pathologies centered near the midline skull base.

Impact of Dynamic Endoscopy and Bimanual-Binarial Dissection in Endoscopic Endonasal Surgery Training: A Laboratory Investigation

Objective The lack of a standard technique may be a relevant issue in teaching endoscopic endonasal surgery (EES) to novice surgeons. The objective of this article is to compare different endoscope positioning and microsurgical dissection techniques in EES training. Methods A comparative trial was designed to evaluate three techniques: group A, one surgeon performing binarial two-hands dissection using an endoscope holder (rigid endoscopy); group B, two surgeons performing a combined binarial two- and three-handed dissection with one surgeon guiding the endoscope (dynamic endoscopy); and group C, two surgeons performing a binarial two-hands dissection with one surgeon dedicated to endoscope positioning and the other dedicated to a two-handed dissection. Trainees were randomly assigned to these groups and oriented to complete surgical tasks in a validated training model for EES. A global rating scale, and a specific-task checklist for EES were used to assess surgical skills. Results The mean scores of the global rating scale and the specific-task checklist were higher (p = 0.001 and 0.002, respectively) for group C, reflecting the positive impact of dynamic endoscopy and bimanual dissection on training performance. Conclusions We found that dynamic endoscopic and bimanual-binarial microdissection techniques had a significant positive impact on EES training.

Hemostasis in Endoscopic Endonasal Skull Base Surgery

William Halsted established the basic principles of modern surgical technique highlighting the importance of meticulous hemostasis and careful tissue handling. These concepts hold true today and are even more critical for endoscopic visualization, making hemostasis one of the most relevant cornerstones for the safe practice of endoscopic endonasal surgery (EES) of the skull base. During preoperative assessment, patients at higher risk for serious hemorrhagic complications must be recognized. From an anatomical point of view, EES can be grossly divided in two major components: sinonasal surgery and sellar-cranial base surgery. This division affects the choice of appropriate technique for control of bleeding that relies mainly on the source of hemorrhage, the tissue involved, and the proximity of critical neurovascular structures. Pistol-grip or single-shaft instruments constitute the most important and appropriately designed instruments available for EES. Electrocoagulation and a variety of hemostatic materials are also important tools and should be applied wisely. This article describes the experience of our team in the management of hemorrhagic events during EES with an emphasis on technical nuances.

Sphenoid sinus mucocele caused by a completely thrombosed intracavernous carotid artery aneurysm: an unusual association

Background Mucocele is an inflammatory disease caused by the retention of mucoid secretions within a paranasal sinus. Although rare, the presence of a vascular lesion inside the sphenoid sinus could determine ostium obstruction, thus causing mucocele development.

Clinical Presentation An 84-year-old woman was referred to our institution due to a lesion abutting into the sphenoid sinus; she was complaining of constrictive frontal headache, progressive worsening of visual acuity in the left eye; later, sudden homolateral ptosis and diplopia occurred. The radiologic evidence was consistent with the diagnosis of thrombosed aneurysm of the right intracavernous carotid artery, surrounded by sphenoidal mucocele. The patient underwent an endoscopic endonasal transsphenoidal approach exclusively for sphenoid mucocele drainage.

Conclusion Although rare, the presence of a vascular lesion inside the sphenoid sinus has to be considered among the possible diagnostic hypotheses of masses abutting in this cavity; the association with mucocele is even more rare and, to date, has not been described.

A case of spontaneous cerebrospinal fluid rhinorrhea: Accurate detection of the leak point by magnetic resonance cisternography

Background:

Spontaneous cerebrospinal fluid (CSF) rhinorrhea is a rare entity. The accurate preoperative localization of the leak point is essential for planning surgical treatment, but is sometimes difficult. To localize the leak point, magnetic resonance cisternography (MRC) is the method of choice, but its effectiveness remains unclear.

Case Description:

A 34-year-old mildly obese female experienced spontaneous CSF rhinorrhea after an attack of bronchial asthma. High-resolution computed tomography (CT) failed to reveal the leak point, while MRC demonstrated an arachnoid herniation at the olfactory cleft. The patient underwent endoscopic endonasal repair of the CSF leak with success. There has been no recurrence of CSF rhinorrhea for 14 months after surgery followed by the administration of acetazolamide.

Conclusion:

We report a rare case of spontaneous CSF rhinorrhea associated with benign intracranial hypertension, in which the leak point was successfully detected by MRC. The CSF leak was completely repaired by minimally invasive endoscopic endonasal surgery. MRC may be a reliable method for detecting CSF leak points.

Endoscopic endonasal repair of spontaneous sphenoid sinus lateral wall meningocele presenting with cerebrospinal fluid leak

Spontaneous sphenoid sinus lateral wall meningoceles are rare lesions with an unknown etiology. Endoscopic endonasal technique is a considerable route in the treatment of this condition. The aim of this paper is to report the etiology, surgical technique, and outcome in a patient repaired via endoscopic endonasal approach. A 51-year-old male patient applied with rhinorrhea started three months ago after an upper respiratory infection. There were no history of trauma or sinus operation. Biochemical analysis of the fluid was positive for beta-2-transferrin. This asypthomatic patient had undergone for repairment of lateral sphenoid sinus meningocele with endoscopic endonasal transsphenoidal approach. After endoscopic endonasal meningocele closure procedure no complications occured and a quick recovery was observed. Endoscopic endonasal approach is an effective and safe treatment modality of spontaneous lateral sphenoid sinus meningoceles and efficient in anterior skull base reconstruction.

Endoscopic endonasal surgery for suprasellar meningiomas: experience with 75 patients

OBJECT

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Anatomy and surgery of the endoscopic endonasal approach to the skull base

The midline skull base is an anatomical area, which extends from the anterior limit of the anterior cranial fossa down to the anterior border of the foramen magnum. For many lesions of this area, a variety of skull base approaches including anterior, antero-lateral, and postero-lateral routes, have been proposed over the last decades, either alone or in combination, often requiring extensive neurovascular manipulation. Recently the endoscopic endonasal approach to the skull base has been introduced to access the midline skull base. The major potential advantage of the endoscopic endonasal technique is to provide a direct anatomical route to the lesion since it does not traverse any major neurovascular structures, thereby obviating brain retraction. The potential disadvantages include the relatively restricted exposure and the higher risk of CSF leak. In the present study we report the endoscopic endonasal anatomy of different areas of the midline skull base from the olfactory groove to the cranio-vertebral junction and accordingly describe the main features of the surgical approaches to each of these regions.