Endoscopic endonasal skull base surgery: past, present and future

Long-Term Outcomes of Endoscopic Resection versus Open Surgery for Locally Advanced Sinonasal Malignancies in Combination with Radiotherapy

Objective  Our objective was to compare the long-term outcomes of endoscopic resection versus open surgery in combination with radiotherapy for locally advanced sinonasal malignancies (SNMs). Methods  Data for continuous patients with sinonasal squamous cell carcinoma and adenocarcinoma who received surgery (endoscopic or open surgery) combined with radiotherapy in our center between January 1999 and December 2016 were retrospectively reviewed. A 1:1 matching with propensity scores was performed. Overall survival (OS), progression-free survival (PFS), and local recurrence rate (LRR) were evaluated. Results  We identified 267 eligible patients, 90 of whom were included after matching: 45 patients in the endoscopy group and 45 in the open group. The median follow-up time was 87 months. In the endoscopic group, 84.4% of patients received intensity-modulated radiotherapy (IMRT), with a mean gross tumor volume (GTV) dose of 68.28 Gy; in the open surgery group, 64.4% of patients received IMRT, with a mean GTV dose of 64 Gy. The 5-year OS, PFS, and LRR were 69.9, 58.6, and 24.5% in the endoscopic group and 64.6, 54.4, and 31.8% in the open surgery group, respectively. Multivariable regression analysis revealed that the surgical approach was not associated with lower OS, PFS, or LRR. The overall postoperative complications were 13% in the endoscopic group, while 21.7% in the open group. Conclusion  For patients with locally advanced SNMs, minimally invasive endoscopic resection, in combination with a higher radiation dose and new radiation techniques such as IMRT, yields survival outcomes similar to those of open surgery in combination with radiotherapy.

Endoscopic Study of Ethmoidal Canals in Cadavers, Including a Histological Analysis of Their Contents

Introduction The advent of the endoscope has enabled the use of the endonasal approach for a variety of diseases. Studying the ethmoidal canals is important for surgeries of the paranasal sinuses and the anterior base of the skull. Objective To investigate the ethmoidal canals and evaluate their structure, the presence of vessels and nerves, their location, and to perform an anatomopathological study of their contents. Methods We evaluated 20 cadavers (20 left and 20 right nasal cavities) through endoscopic dissection of the anterior base of the skull and exposure of the medial periorbita and dura mater; then, the ethmoidal canals were located and measured in relation to the anterior wall of the sphenoid sinus and between the ethmoidal canals, followed by removal of their content for histological analysis. Results Vessels were present in 75% of the left anterior ethmoidal canals, 70% of the left posterior ethmoidal canals, 75% of the left middle ethmoidal canals, 85% of the right anterior ethmoid canals, and 64.5% of the right posterior ethmoid canals; 50% of the right middle ethmoidal canals contained one vessel. Conclusion The ethmoidal canal does not necessarily contain an ethmoidal artery. Studies with a larger sample should be performed to quantify the correct proportion of arteries and ethmoidal canals.

360 Degrees Endoscopic Access to and Through the Orbit

The treatment of pathologies located within and surrounding the orbit poses considerable surgical challenges, due to the intricate presence of critical neurovascular structures in such deep, confined spaces. Historically, transcranial and craniofacial approaches have been widely employed to deal with orbital pathologies. However, recent decades have witnessed the emergence of minimally invasive techniques aimed at reducing morbidity. Among these techniques are the endoscopic endonasal approach and the subsequently developed endoscopic transorbital approach (ETOA), encompassing both endonasal and transpalpebral approaches. These innovative methods not only facilitate the management of intraorbital lesions but also offer access to deep-seated lesions within the anterior, middle, and posterior cranial fossa via specific transorbital and endonasal corridors. Contemporary research indicates that ETOAs have demonstrated exceptional outcomes in terms of morbidity rates, cosmetic results, and complication rates. This study aims to provide a comprehensive description of endoscopic-assisted techniques that enable a 360° access to the orbit and its surrounding regions. The investigation will delve into indications, advantages, and limitations associated with different approaches, while also drawing comparisons between endoscopic approaches and traditional microsurgical transcranial approaches.

Evaluation of sinonasal-related quality of life of 49 patients undergoing endoscopic skull base surgery

OBJECTIVE

This study aimed to evaluate the sinonasal-related Quality of Life (QoL) in patients undergoing endoscopic skull base surgery.

METHODS

A retrospective study was performed, including patients with benign and malignant tumors at a single institution. Each patient completed the 22-Item Sino-Nasal Outcome Test (SNOT-22) and the Empty Nose Syndrome 6 Item Questionnaires (ENS6Q) to assess their perceived QoL at least 2-months after treatment.

RESULTS

Forty-nine patients were enrolled in this study. The average score was 25.1 (Stander Deviation [SD] 14.99) for SNOT-22 and 6.51 (SD=5.58) for ENS6Q. Analysis of the overall results for the SNOT-22 showed that olfactory damage was the most serious syndrome. The most frequently reported high-severity sub-domains in SNOT-22 were nasal symptoms and sleep symptoms. Nasal crusting was the most severe item in ENS6Q according to the report. Nine patients (18.4%) had a score higher than 10.5 which indicates the high risk of Empty Nose Syndrome (ENS). SNOT-22 score was related to the history of radiotherapy (p< 0.05), while the ENS6Q score was not.

CONCLUSIONS

The possibility of patients suffering from ENS after nasal endoscopic skull base surgery is at a low level, although the nasal cavity structure is damaged to varying degrees. Meanwhile, patients undergoing endoscopic skull base surgery were likely to suffer nasal problems and sleep disorders. Patients who had received radiotherapy have a worse QoL than those without a history of radiotherapy.

LEVEL OF EVIDENCE

Level 3.

Small spheno-ethmoidal meningoencephalocele versus ethmoidal mucocele in spontaneous intracranial hypotension

Background

Meningoencephalocele is defined as an abnormal sac of brain tissue and meninges extending beyond natural skull margins, often leading to cerebrospinal fluid (CSF) leakage. When this condition arises in the spheno-ethmoidal region, the diagnosis becomes more challenging as it can be mistaken for other nasal pathologies, such as mucocele.

Research question

We show in this case report a non-congenital sphenoethmoidal meningoencephalocele causing rhinoliquoral fistula and spontaneous intracranial hypotension.

Results

this 65-year-old woman presented with sporadic rhinoliquorrhoea associated with orthostatic headache, nausea and dizziness. Brain MRI revealed a small lesion of an ethmoidal sinus, which was successfully treated with endoscopic endonasal surgery. Histology confirmed the presence of meningoencephalic tissue positive for S100 protein on immunohistochemistry.

Conclusions

When dealing with lesions of the paranasal sinuses in contact with the anterior skull base, rhinoliquorrhoea presence suggests meningoencephalocele. In dubious cases, a proper workup, including a thorough clinical history and neurological examination, specific imaging, and a direct search of CSF-like markers, is essential to support the differential diagnosis. In such cases, a transnasal endoscopic surgical approach is recommended to obtain a final histological diagnosis and to perform eventual dural plastic surgery.

Skull base reconstruction using in situ bone flap in patients with pituitary adenomas treated by endoscopic endonasal approach

Objective

The objective of this study is to study the effect of in situ bone flap (ISBF) repositioning, a recently proposed rigid skull base reconstruction technique, on patients diagnosed with pituitary adenoma undergoing endoscopic endonasal approach (EEA).

Method

A retrospective analysis was conducted on 188 patients with pituitary adenomas who underwent EEA from February 2018 to September 2022. Patients were divided into the ISBF group and non-ISBF group, according to whether ISBF was used during skull base reconstruction.

Results

Of the 75 patients in the non-ISBF group, 6 had postoperative cerebrospinal fluid (CSF) leakage (8%), while only 1 of 113 patients in the ISBF group (0.8%) had postoperative CSF leakage, indicating that the incidence of postoperative CSF leakage in the ISBF group was significantly lower than that in the non-ISBF group (P = 0.033). In addition, we also found that the postoperative hospitalization days of patients in the ISBF group (5.34 ± 1.24) were significantly less than those in the non-ISBF group (6.83 ± 1.91, P = 0.015).

Conclusion

ISBF repositioning is a safe, effective, and convenient rigid skull base reconstruction method for patients with pituitary adenoma treated by EEA, which can significantly reduce the rate of postoperative CSF leakage and shorten postoperative hospital stays.

Efficacy of a Novel Augmented Reality Navigation System Using 3D Computer Graphic Modeling in Endoscopic Transsphenoidal Surgery for Sellar and Parasellar Tumors

In endoscopic transsphenoidal skull base surgery, knowledge of tumor location on imaging and the anatomic structures is required simultaneously. However, it is often difficult to accurately reconstruct the endoscopic vision of the surgical field from the pre-surgical radiographic images because the lesion remarkably displaces the geography of normal anatomic structures. We created a precise three-dimensional computer graphic model from preoperative radiographic data that was then superimposed on a visual image of the actual surgical field and displayed on a video monitor during endoscopic transsphenoidal surgery. We evaluated the efficacy of this augmented reality (AR) navigation system in 15 consecutive patients with sellar and parasellar tumors. The average score overall was 4.7 [95% confidence interval: 4.58-4.82], which indicates that the AR navigation system was as useful as or more useful than conventional navigation in certain patients. In two patients, AR navigation was assessed as less useful than conventional navigation because perception of the depth of the lesion was more difficult. The developed system was more useful than conventional navigation for facilitating an immediate three-dimensional understanding of the lesion and surrounding structures.

Discontinuation of Postoperative Prophylactic Antibiotics for Endoscopic Endonasal Skull Base Surgery

Background  Postoperative prophylactic antibiotic usage for endoscopic skull base surgery varies based on the institution as evidence-based guidelines are lacking. The purpose of this study is to determine whether discontinuing postoperative prophylactic antibiotics in endoscopic endonasal cases led to a difference in central nervous system (CNS) infections, multi-drug resistant organism (MDRO) infections, or other postoperative infections. Methods  This quality improvement study compared outcomes between a retrospective cohort (from September 2013 to March 2019) and a prospective cohort (April 2019 to June 2019) after adopting a protocol to discontinue prophylactic postoperative antibiotics in patients who underwent endoscopic endonasal approaches (EEAs). Our primary end points of the study included the presence of postoperative CNS infection, Clostridium difficile ( C. diff ), and MDRO infections. Results  A total of 388 patients were analyzed, 313 in the pre-protocol group and 75 in the post-protocol group. There were similar rates of intraoperative cerebrospinal fluid leak (56.9 vs. 61.3%, p  = 0.946). There was a statistically significant decrease in the proportion of patients receiving IV antibiotics during their postoperative course ( p  = 0.001) and those discharged on antibiotics ( p  = 0.001). There was no significant increase in the rate of CNS infections in the post-protocol group despite the discontinuation of postoperative antibiotics (3.5 vs. 2.7%, p  = 0.714). There was no statistically significant difference in postoperative C. diff (0 vs. 0%, p  = 0.488) or development of MDRO infections (0.3 vs 0%, p  = 0.624). Conclusion  Discontinuation of postoperative antibiotics after EEA at our institution did not change the frequency of CNS infections. It appears that discontinuation of antibiotics after EEA is safe.

Radiological relationship of the ethmoid slit with the frontal sinus and the anterior ethmoidal artery and applications to the frontal sinus drillout

PURPOSE

To compare two types of CT acquisition parameters: CT scan of the facial bone and CT scan of the sinuses, for studying the ethmoidal slit and its relationship with the frontal sinus and anterior ethmoidal artery.

MATERIALS AND METHODS

Retrospective study of 145 scans of the sinuses and 79 of the facial bones performed between 2012 and 2016. On each scan, the visibility of the ethmoidal slits, their length, their distance from the ethmoidal artery, and their relationship with the anterior and posterior wall of the frontal sinus were studied.

RESULTS

The ethmoidal slit was better visualized on CT scans of the facial bone (58.2%) than on those of the sinuses (43.1%) (p = 0.02). The distance between the anterior ethmoidal artery and the anterior part of the cribriform plate was 9.3 mm for CT scans of the facial bone and 8.4 mm for CT scans of the sinuses. The theoretical risk of damaging the glabellar soft tissue and that of damaging the meninges during a frontal sinusotomy was evaluated, respectively, at 9.6% and 26.1% for CT scans of the facial bone, and at 6.2% and 21.5% for sinus scans.

CONCLUSIONS

CT scans of the facial bone are better than CT scans of the sinuses for identifying ethmoidal slits and their distance from the canal of the anterior ethmoidal artery. The identification of these elements is relevant for the surgeon during frontal sinus surgery and makes it possible to assess the risk of damaging the glabellar soft tissue or meninges. Performing a CT scan of the facial bone seems preferable to that of a CT scan of the sinuses in certain pathological situations, such as cerebrospinal rhinorrhea or revision surgeries of the frontal sinus.

Historiographies of surgical innovation: endoscopic endonasal pituitary surgery

The historiography of medicine has shifted from narratives of inevitable progress, authored mainly by the medical profession, to a more complex, analytical approach in which historians place medicine in its social context. However, the history of surgery has lagged behind somewhat; Christopher Lawrence suggests this is because the recent focus on the construction of medical knowledge does not incorporate the practical aspects of surgery, which are difficult to extract from their previous linear narrative. Thomas Schlich likewise recognises that surgery is both knowledge and skill-therefore more of a 'craft' than medicine. A possible solution is aligning the history of surgery with the history of technology: analysing the interplay of instruments and human activity.This case study uses the history of endoscopic endonasal pituitary surgery to explore the historiography of surgical innovation, in the context of its heavy reliance on both technology and interdisciplinary divisions of labour. Re-enactment, evolutionary frameworks and using Social Construction of Technology methods all require close collaboration between historian and surgeon to bridge the gap between scholarship and tacit knowledge.

Extended endoscopic endonasal approach for resecting anterior intrinsic third ventricular craniopharyngioma

Background

The surgical treatment of the extended endoscopic endonasal approach (EEEA) is a safe and effective treatment for suprasellar craniopharyngiomas. However, due to damage to the hypothalamus and third ventricle floor (TVF), EEEA is generally regarded as unsuitable in treating intrinsic third ventricle craniopharyngioma (ITVC) that is entirely within the third ventricle. Until now, there have been only a small number of reports using EEEA to treat TVC via a supra-infrachiasmatic approach. Given that the translamina terminalis (TLT) corridor was used in the transcranial subfrontal approach, EEEA via a suprachiasmatic approach may be feasible and practical to treat ITVC. In the current study, we accumulated experience applying the suprachiasmatic translamina terminalis (STLT) corridor for anterior treatment of ITVC.

Methods

From March 2016 to December 2020, 14 patients with ITVC in our center were analyzed retrospectively. All patients underwent surgery by EEEA via an STLT corridor. The multilayer reconstruction technique was adopted to achieve skull base reconstruction. Data concerning the patient’s tumor resection, vision, hypophyseal hormone, and complications were collected.

Results

Gross-total resection was achieved in 13 (92.8%) of14 patients, with achievement of near-total (90%) resection in the remaining 1 patient. Nine cases (64.3%) were papillary craniopharyngiomas, and the other 5 cases were adamantinomatous subtypes. Postoperatively, 3 patients with pituitary insufficiency received hormone replacement therapy. No permanent diabetes insipidus or hypothalamic obesity was found. All pairs showed significant improvement or stability in vision except 1 patient who encountered visual deterioration. No other neurological deficit occurred postoperatively. Observation results for the exudation of nasal tissue and the length of hospitalization were satisfactory. After a mean follow-up period of 26.2 months, tumor recurrence was not observed.

Conclusion

TLT is a minimally invasive corridor used in EEEA for treating anterior ITVC without increasing risks of visual and hormonal deficits. The multilayered reconstruction technique we used is a safe and effective method for achieving watertight closure and avoiding cerebrospinal fluid leaks and infection. The endonasal approach via STLT provides a new, safe and efficacious operative strategy that should be considered a surgical alternative in treating ITVC.

Endoscopic transoral approach to the parapharyngeal space: technical nuances and preliminary results

OBJECTIVE

Surgical management is the mainstay of treatment for tumours in the parapharyngeal space. This study aimed to evaluate the indications, limits and technical nuances of the endoscopic transoral approach.

METHOD

Thirteen patients with parapharyngeal space tumours that were treated between May 2017 and November 2020 were included in this retrospective study.

RESULTS

All patients underwent surgery for complete oncological resection except one patient who received treatment for diagnostic purposes. No major complications were reported, with excellent control of the vital structures of the parapharyngeal space.

CONCLUSION

The endoscopic transoral approach to the parapharyngeal space is a promising alternative approach for selected parapharyngeal space tumours with satisfactory outcomes.

Clinical Efficacy of the Multilayered Skull Base Reconstruction Using In Situ Bone Flap in Endoscopic Endonasal Approach for Craniopharyngioma

Objective  The aim of the study is to summarize and analyze the efficacy of the multilayered skull base reconstruction using in situ bone flap in endoscopic endonasal approach (EEA) for craniopharyngiomas. Methods  A retrospective review of 65 patients who underwent resection of their histopathology confirmed craniopharyngiomas performed at a single institution. Based on the team's understanding and mastery of skull base reconstruction techniques, patients were divided into two groups according to the methods of reconstruction in two periods. First (March 2015 through August 2016), osseous reconstruction was not adopted and served as the control group (34 cases). Second (September 2016 through July 2019), in situ bone flap repair of the skull base (complete osseous reconstruction) served as observation group (31 cases). The length of hospitalization and nasal exudation, bed rest time of hospital discharge, the incidence of cerebrospinal fluid leaks, lumbar drainage, and intracranial/pulmonary infections were collected and compared. Results  Compared with the control group, patients in the observation group had obviously less lumbar drainage and CSF leakage ( p  < 0.05), but had no significant difference in cases of re-operation, meningitis, and pulmonary infection. At the meantime, cases of nasal exudation, bed rest, and hospitalization of the observation group were significantly reduced ( p  < 0.05) in the observation group. Conclusion  The multilayered reconstruction technique (especially using in situ bone flap, combined with vascularized pedicled nasoseptal flap) is a safe and effective method in achieving watertight closure after EEEA, and can significantly reduce the incidence of cerebrospinal fluid leaks, and facilitate rehabilitation in skull base reconstruction of craniopharyngiomas.

Infra-Temporal and Pterygo-Palatine Fossae Tumors: A Frontier in Endoscopic Endonasal Surgery—Description of the Surgical Anatomy of the Approach and Report of Illustrative Cases

Infratemporal and pterygopalatine fossae (ITF and PPF) represent two complex paramedian skull base areas, which can be defined as jewelry boxes, containing a large number of neurovascular and osteomuscular structures of primary importance. They are in close communication with many craniofacial areas, such as nasal/paranasal sinuses, orbit, middle cranial fossa, and oral cavities. Therefore, they can be involved by tumoral, infective or inflammatory lesions spreading from these spaces. Moreover, they can be the primary site of the development of some primitive tumors. For the deep-seated location of ITF and PPF lesions and their close relationship with the surrounding functional neuro-vascular structures, their surgery represents a challenge. In the last decades, the introduction of the endoscope in skull base surgery has favored the development of an innovative anterior endonasal approach for ITF and PPF tumors: the transmaxillary-pterygoid, which gives a direct and straightforward route for these areas. It has demonstrated that it is effective and safe for the treatment of a large number of benign and malignant neoplasms, located in these fossae, avoiding extensive bone drilling, soft tissue demolition, possibly unaesthetic scars, and reducing the risk of neurological deficits. However, some limits, especially for vascular tumors or lesions with lateral extension, are still present. Based on the experience of our multidisciplinary team, we present our operative technique, surgical indications, and pre- and post-operative management protocol for patients with ITF and PPF tumors.

Treatment strategies for inverted papillomas with intracranial or intraorbital involvement

OBJECTIVE

Sinonasal inverted papillomas are challenging benign tumours of the nasal cavity because of their high recurrence rates and the lifetime malignant transformation risk of 10 per cent as well as their locally aggressive behaviour. This study aimed to describe treatment strategies for inverted papillomas with intracranial or intraorbital involvement.

METHOD

This was a prospective case series study of 18 patients with inverted papilloma with intracranial or intraorbital involvement. Patient demographic data, imaging, pathology, surgical technique and recurrences were recorded prospectively over a period of seven years.

RESULTS

A total of 83 per cent of the patients in this study had been previously operated on, consisting of 8 cases with intracranial involvement, 1 case with intraorbital involvement and 9 with both. During follow up with a medium of 37 months (range, 13-115 months) there were two recurrences.

CONCLUSION

It was postulated that intracranial or intraorbital involvement observed in this series was the result of multiple revisions. However, using accurate imaging protocols and the pedicle-oriented approach for tumour excision, complete tumour removal was achieved in most cases with minimal post-operative complications.

Endoscopic Endonasal Prelacrimal Approach: Radiological Considerations, Morbidity, and Outcomes

OBJECTIVE/HYPOTHESIS

This study describes a multicentric experience with the use of prelacrimal approach (PLA), focusing on preoperative radiological parameters potentially associated with surgical outcomes and postoperative morbidity.

STUDY DESIGN

Retrospective case-series.

METHODS

A retrospective review of patients undergoing PLA in three European referral centers was performed. The post-operative morbidity was analyzed in relation to two radiological parameters: width of prelacrimal recess (WPR) and internal angle of pyriform notch (APN).

RESULTS

The study included 28 patients affected by Schneiderian papilloma (20 cases), inflammatory disease (6 cases), schwannoma (1 case), and osteoma (1 case). The most reported sequela was paresthesia of ipsilateral anterior superior alveolar process (25% of the cases). An association between post-operative morbidity and APN was observed (P = .047).

CONCLUSIONS

Preoperative radiological evaluation of WPR is crucial in understanding the feasibility of the approach, while APN measurement may predict postoperative morbidity, which is paramount in the patients' counseling.

LEVEL OF EVIDENCE

4 case-series Laryngoscope, 131:1715-1721, 2021.

The Application of Three-Dimensional Technology Combined With Image Navigation in Nasal Skull Base Surgery

Three-dimensional (3D) technology including 3D reconstruction and 3D printing technology, has been widely used in clinical treatment, especially in surgical planning, and image navigation technology, which can make surgical procedures more accurate, now is also increasingly favored by surgeons. But the combination of those 2 technologies was rarely reported. Thus, this study will preliminarily investigate the feasibility and the effect of the combination of 2 technologies in endonasal skull base surgery. Eight patients were involved in this study (from October 2016 to July 2017 at The Affiliated Hospital of Qingdao University), 5 cases of nasal skull base tumors and 3 cases of foreign body perforation. All operations were done under the assistance of 3D technology and image guidance system. Surgical discussion with patient, preoperative planning and clinical teaching were investigated between 2D images and 3D models by voting. For all cases, 3D reconstruction model and 3D printed model were deemed to be more helpful than CT/MRI images in surgical discussion with the patient; surgical simulation on 3D model in preoperative planning was largely deemed to be helpful and very helpful; and in clinical teaching, 3D models combined with image guidance system were deemed to be more helpful in understanding the disease than using 2D images. Besides, all patients recovered well after surgery, no recurrence and complications were found in the follow-up. The combination of 3D technology and electromagnetic image guidance system could improve surgical efficiency and the quality of clinical teaching.

Endoscopic endonasal and transorbital routes to the petrous apex: anatomic comparative study of two pathways

BACKGROUND AND OBJECTIVE

Surgical approaches to the petrous apex region are extremely challenging; while subtemporal approaches and variations represent the milestone of the surgical modules to reach such deep anatomical target, in a constant effort to develop minimally invasive neurosurgical routes, the endoscopic endonasal approach (EEA) has been tested to get a viable corridor to the petroclival junction. Lately, another ventral endoscopic minimally invasive route, i.e., the superior eyelid endoscopic transorbital approach, has been proposed to access the most lateral aspect of the skull base, including the petrous apex region. Our anatomic study aims to compare and combine such two endoscopic minimally invasive pathways to get full access to the petrous apex. Three-dimensional reconstructions and quantitative and morphometric data have been provided.

MATERIAL AND METHODS

Five human cadaveric heads (10 sides) were dissected. The lab rehearsals were run as follows: (i) preliminary pre-operative CT scans of each specimen, (ii) pre-dissection planning of the petrous apex removal and its quantification, (iii) petrous apex removal via endoscopic endonasal route, (iv) post-operative CT scans, (v) petrous apex removal via endoscopic transorbital route, and (v) final post-operative CT scan with quantitative analysis. Neuronavigation was used to guide all dissections.

RESULTS

The two endoscopic minimally invasive pathways allowed a different visualization and perspective of the petrous apex, and its surrounding neurovascular structures. After both corridors were completed, a communication between the surgical pathways was highlighted, in a so-called connection area, surrounded by the following important neurovascular structures: anteriorly, the internal carotid artery and the Gasserian ganglion; laterally, the internal acoustic canal; superiorly, the abducens nerve, the trigeminal root, and the tentorium cerebelli; inferomedially, the remaining clivus and the inferior petrosal sinus; and posteriorly, the exposed area of the brainstem. Used in a combined fashion, such multiportal approach provided a total of 97% of petrous apex removal. In particular, the transorbital route achieved a mean of 48.3% removal in the most superolateral portion of the petrous apex, whereas the endonasal approach provided a mean of 48.7% bone removal in the most inferomedial part. The difference between the two approaches was found to be not statistically significant (p = 0.67).

CONCLUSION

The multiportal combined endoscopic endonasal and transorbital approach to the petrous apex provides an overall bone removal volume of 97% off the petrous apex. In this paper, we highlighted that it was possible to uncover a common path between these two surgical pathways (endonasal and transorbital) in a so-called connection area. Potential indications of this multiportal approach may be lesions placed in or invading the petrous apex and petroclival regions that can be inadequately reached via transcranial paths or via an endonasal endoscopic route alone.

Nasolacrimal duct stenosis-Surgery with a novel robotic endoscope positioning system

BACKGROUND

Distal nasolacrimal duct stenosis is usually treated by head and neck surgeons with transnasal endoscopic dacryocystorhinostomy (DCR). The presented clinical study discusses advantages and drawbacks of a robot-assisted endoscope positioning system, which allows for hands-free visualization of the surgical field.

MATERIAL AND METHODS

Two patients were treated by surgical DCR. The endoscopic positioning system (Medineering^® ) features a mechatronic holding arm with four segments and seven degrees of freedom. It is driven by using a foot pedal.

RESULTS

Visualization and instrumentation of the surgical field including the relevant anatomical landmarks were feasible. The endoscope position could be controlled with sufficient precision. The surgeon was able to maintain bimanual instrumentation.

CONCLUSION

The endoscope positioning system allows for two-handed surgery, which facilitates the essential steps of the surgical procedure. If the benefit of the system is sufficient for the use in clinical routine, it has to be evaluated in repeated applications.

A Rare Case of Sphenoid Encephalocoele Presenting with Fifth Cranial Nerve Involvement

A 14-year-old girl presented with chronic headache, recurrent episodes of vomiting, fever, and two episodes of generalized tonic clonic seizure in the past 2 months. Neuroimaging revealed herniation of the brain along with the dura through a defect in the left greater wing of the sphenoid. Left pterional craniotomy was carried out. Herniation of the dural sac along with its contents through the bony defect in the greater sphenoid wing was identified lateral to the V2 nerve passing through the foramen rotundum. The dural defect was repaired. Bony defect was covered with a circular titanium plate. The patient did not have cerebrospinal fluid rhinorrhea postoperatively. At 6-month follow-up, she was asymptomatic.

The effect of three-dimensional visualisation on performance in endoscopic sinus surgery: A clinical training study using surgical navigation for movement analysis in a randomised crossover design

OBJECTIVES

Endoscopic imaging techniques and endoscopic endonasal surgery (EES) expertise have evolved rapidly. Only few studies have assessed the effect of three-dimensional (3D) endoscopy on endoscopic sinus surgery (ESS). The present study aimed to objectively and subjectively assess the additional value of 3D high-definition (HD) endoscopy in ESS.

DESIGN

A randomized crossover study of endoscopic surgery performance, using five ESS tasks of varying complexity, performed on Thiel embalmed human specimens.

SETTING

Simulated surgical environment.

PARTICIPANTS

Thirty participants, inexperienced in ESS.

MAIN OUTCOME MEASURES

Performance was assessed using video imaging, surgical navigation and questionnaires. Main outcome measures were as follows: efficiency (defined by time to task completion), distance covered inside the nose, average velocity towards target, accuracy (measured by error rate), and subjective assessment of endoscope characteristics.

RESULTS

During ESS tasks, both efficiency and accuracy did not differ significantly between 2D HD and 3D HD endoscopy. Subjectively, imaging characteristics of the 3D HD endoscope were rated significantly better.

CONCLUSIONS

ESS performance of inexperienced participants was not significantly improved by the use of 3D HD endoscopy during ESS tasks, although imaging characteristics of the 3D HD endoscope were rated significantly better. Surgical field characteristics and surgical techniques are likely to influence any additional value of 3D HD endoscopy.

Endoscopic Endonasal Transsphenoidal Surgery: History and Evolution

In previous decades, extensive and disfiguring transfacial and/or transcranial approaches were used to reach the sellar and parasellar areas. However, these surgical routes were burdened by severe complications and high mortality rates. Recently, the development of endoscopic endonasal techniques has revolutionized the surgical strategies for approaching the sella and adjacent areas and increased the development of transsphenoidal surgery. With these techniques, surgeons have been able to overcome the visual limitations of the open surgical approaches and access areas previously hidden from view. After the contributions of the Pittsburgh duo, Carrau and Jho, pioneers of pure endoscopic surgery, our school began to implement this technique, introducing technical innovations and variations, describing the anatomical details and defining new routes, and playing a key role in its widespread clinical application.

Endoscopic Resection of Sinonasal Inverted Papilloma: A Multivariate Retrospective Analysis of Factors Affecting Recurrence and Persistence

Sinonasal inverted papilloma (IP) is the most common benign epithelial tumor in the nasal cavity and paranasal sinuses, with a worldwide incidence between 0.6 and 1.5/100 000 persons per year. However, only a few studies have investigated patient-dependent factors related to IP recurrence and persistence. According to available evidence, these factors are still debated, and results are contradictory. In this multicenter retrospective study, we analyzed the clinical records of 130 patients who were surgically treated for sinonasal IP to evaluate the factors affecting recurrence and persistence of IP and compared the curative rates of different surgical approaches. Our analysis showed that IP recurrence is strongly related to specific risk factors including incomplete surgical removal, stage of disease, site of the lesion, surgical technique, and malignancy rate. In conclusion, the recurrence of IP may be affected by several risk factors; these factors must be carefully considered during clinical evaluation and especially during the follow-up of patients with IP.

Anatomical Workspace Study of Endonasal Endoscopic Transsphenoidal Approach

Purpose

To determine the workspace through an anatomical dimensional study of the skull base to further facilitate the design of the robot for endonasal endoscopic transsphenoidal (EET) surgery.

Methods

There were 120 cases having a paranasal sinus CT scan in the database. The internal volumes of the nasal cavities (NC), the volumes of the sphenoid sinuses (SS), and the distance between the anterior nasal spine and base of the sellar (d-ANS-BS) were measured.

Results

The Pearson correlation coefficient (PCC) between the relevant distances and the volumes of the right NC was 0.32; between the relevant distances and the volumes of the left NC was 0.43; and between the relevant distances and volumes of NC was 0.41; with a statistically significant difference (p < 0.001). All PCCs had a statistically significant meaningful difference (p < 0.05).

Conclusion

The volume of NCs were significantly correlated with distances (p < 0.05). The safest and shortest distance to guide the robotic arm length in the EET approach could be represented by d-ANS-BS. This result was also used as primary information for further robotic design.

Anatomo-radiological study supporting the use of ipsilateral nasoseptal flap for the transpterygoid management of temporo-sphenoidal meningoceles. A review of 21 cases

OBJECTIVES

Surgical treatment of temporo-sphenoidal meningoceles involves the reduction of the meningocele, watertight closure and defect coverage with a nasoseptal flap (NSF). It can be performed contralaterally or ipsilaterally: in the latter situation, the pedicle of the flap must be dissected into the pterygopalatine fossa. The objective of this study was to evaluate the benefit of using an ipsilateral NSF in transpterygoid approaches for the management of temporo-sphenoidal meningoceles, compared to a contralateral NSF, based on a radiological study.

MATERIAL AND METHODS

Retrospective monocentric study of 21 cases, between 2002 and 2018. Measurement of the NSF lengths, and lengths needed to cover the defect were evaluated on the preoperative scanner. Early and later failure and complication rates were evaluated.

RESULTS

Seventeen cases of temporo-sphenoidal meningoceles with available CT scan were identified. The mean duration of follow up was 27.9 months [1-147]. Theoretical lengths of the ipsi and contralateral NSF were comparable: 71.4±7.8mm vs. 78.8±8mm, P=0.729. In 8 cases/18 (42%), the theoretical length of the contralateral NSF was not long enough to cover the defect beyond the V2 (mean lack of 8.87±6.6mm). In all cases, the theoretical length of the ipsilateral NSF was sufficient to cover the defect. In the case series, failure and complication rates were similar.

CONCLUSION

The use of an ipsilateral NSF for the transpterygoid management of temporo-sphenoidal meningoceles, although more complex, allows a better coverage of the defect, compared to the contralateral NSF, which is not long enough in 42% of cases.

Translational genomics of sinonasal cancers

The sinonasal cavities harbor a wide variety of histologically distinct cancers, the majority very aggressive with 5-year survival rates between 30-60% and local recurrence as the main cause of death. This is a complex anatomic area, close to structures such the eyes and the brain, which is of special relevance for surgery and postoperative radiotherapy. The low incidence of these rare tumors hampers accumulation of experience with diagnosis and clinical managment as well as knowledge on recurrent genetic aberrations or testing of new treatment strategies. However, recent years have seen a growing number of publications on genetic aberrations providing data that can aid or fine-tune classification and provide molecular targets for treatment with specific inhibitors. In addition, new sinonasal cancer models are created that enable preclinical testing of candidate inhibitor drugs. With more and more novel targeted therapies being developed, options for personalized treatment of sinonasal cancer patients are now opening up.

Audit of Complications in an Otolaryngology Led Skull-Base Surgical Practice

Objective  This study was aimed to classify and study complications of surgery of the cranial base, primarily from an otorhinolaryngology perspective. Design  This study was designed with consecutive cohort of skull base surgical cases. Setting  Tertiary referral academic center. Participants  Patients having skull-base surgery at a otorhinolaryngology based skull-base unit, from 2002 to 2015. Main Outcome Measures  Enumeration of complications is the main outcome of this study. Surgical procedures, categorized for complexity as per a unified system, are applicable to endoscopic and open procedures. Complications were categorized as per the British Association of Otolaryngologists coding of surgical complications. Complication classified as major if life-threatening, causing permanent disability, or compromising the result of surgery. Results  A total of 342 patients ( n  = 342) were operated; 13 patients' records were excluded due to < 6 months posttreatment follow-up. The study group constituted 204 anterior skull-base (endoscopic, 120; open/external, 84) and 125 lateral skull-base procedures. Complication rates noted to increase in both groups with increasing complexity of surgical intervention. Anterior skull-base surgery (total complications, 11%; major, 3%; death, 0.5%) noted to have significantly less surgical complications than lateral skull-base surgery (total complications, 33%; major, 15%; death, 1.6%; p  < 0.001). Among the anterior procedures no significant difference noted among endoscopic and external approaches when compared across similar surgical complexity. Conclusion  Despite improvement in surgical and perioperative care, the overall major complication rate in a contemporary otolaryngology led, primarily extradural, skull-base practice is noted at 8%. Perioperative mortality, though rare, was encountered in 1%. A standard method for categorization of surgical complexity and the grade of complications as reported here is recommended.

Treatment Outcomes and Prognostic Factors of Adult Sinonasal Sarcomas: A Single-Institution Case Series

BACKGROUND The purpose of this study was to investigate the treatment outcomes and evaluate the prognostic factors of adult sinonasal sarcomas. MATERIAL AND METHODS A retrospective review was performed on consecutive patients with adult sinonasal sarcomas treated in our institution from 2005 to 2016. The Kaplan-Meier method was used to evaluate local recurrence-free survival (LRFS), distant metastases-free survival (DMFS), and overall survival (OS). Univariate and multivariate analyses using Cox proportional hazard models were performed to determine the prognostic factors associated with survival outcomes. RESULTS A total of 49 patients were followed up for 6-122 months, with a median time of 36 months. The 5-year LRFS, DMFS, and OS rates of all patients were 68.3%, 62.8%, and 43.2%, respectively. The results of univariate analysis revealed that patients with an advanced stage of primary tumor and those who received incomplete surgical resection had worse LRFS (p=0.013; p=0.026). Patients with the histological type rhabdomyosarcoma (RMS) and existing regional lymph node metastasis had worse DMFS (p=0.000; p=0.001). The histological type RMS, advanced stage of primary tumor, existing regional lymph node metastasis, and receiving incomplete surgical resection had an unfavorable effect on OS (p=0.001; p=0.002; p=0.008; p=0.011). The results of multivariate analysis showed that histological type and degree of surgical resection were the independent prognostic factors for OS. CONCLUSIONS Our results suggest that the histological type RMS and receiving incomplete surgical resection are independent prognostic factors for worse OS.

Mucosal melanoma of the cranio-facial region: Surgical challenges and therapeutic options

OBJECTIVE

Although current therapeutic options for cutaneous melanoma (CM) are constantly improving survival, mucosal melanoma (MM) remains a rare tumor disease with a poor clinical outcome. While radical surgery is the gold standard, clear margin resections in the head and neck area are particularly critical due to high density of vulnerable structures. Adjuvant therapeutic options increases local control and data on the effect of systemic agents is sparse. The aim of this study was to elucidate surgical challenges in the craniofacial area and to evaluate the effect of local and systemic therapy in Head and Neck Mucosal Melanoma (HNMM).

METHODS

In total, 21 patients with nasal mucosal malignant melanoma were included in this study over the course of 20 years in two German tertiary referral centers. Patient characteristics and conducted therapy as well as clinical outcomes were analyzed retrospectively.

RESULTS

By performing survival analysis for multimodal therapies, we observed a superiority effect of interferon therapy compared to surgery with radiation and surgery alone in the first therapeutic approach. However, patients treated with surgery alone in a recurrent setting showed the best outcome.

CONCLUSION

Both, Interferon and radiation as adjuvant therapies, demonstrated survival benefits in initial treatment compared to surgery alone. Analysis after recurrence, however, revealed salvage surgery as a reliable and powerful tool to prolong post-recurrence survival without exposing palliative patients to the risk of severe adverse events from systemic therapies.

Transorbital endoscopic eyelid approach for resection of sphenoorbital meningiomas with predominant hyperostosis: report of 2 cases

Sphenoorbital meningiomas (SOMs) are slow-growing tumors that originate from the sphenoidal wing and are associated with visual deterioration, extrinsic ocular movement disorders, and proptosis caused by hyperostosis of the lateral wall of the orbit. In some cases, the intracranial component is quite small or “en plaque,” and the majority of the symptoms arise from adjacent hyperostosis. Craniotomy has traditionally been the standard of care, but new minimally invasive multiportal endoscopic approaches offer an alternative. In the current study, the authors to present their experience with the transorbital endoscopic eyelid approach for the treatment of 2 patients with SOMs and sphenoid wing hyperostosis.

Clinical and radiological data for patients with SOMs who underwent a transorbital endoscopic eyelid approach were retrospectively reviewed. Surgical technique and clinical and radiographic outcomes were analyzed.

The authors report the cases of 2 patients with SOMs and proptosis due to sphenoid wing hyperostosis. One patient underwent prior craniotomy to debulk the intracranial portion of the tumor, and the other had a minimal intracranial component. Both patients were discharged 2 days after surgery. MR images and CT scans demonstrated a large debulking of the hyperostotic bone. Postoperative measurement of the proptosis with the aid of an exophthalmometer demonstrated significant reduction of the proptosis in one of the cases. Persistence of intraconal tumor in the orbital apex limited the efficacy of the procedure in the other case. A review of the literature revealed 1 publication with 3 reports of the transorbital eyelid approach for SOMs. No measure of relief of proptosis after this surgery had been previously reported.

The transorbital endoscopic approach, combined with endonasal decompression of the medial orbit, may be a useful minimally invasive alternative to craniotomy in a subset of SOMs with a predominantly hyperostotic orbital wall and minimal intracranial bulky or merely en plaque disease. In these cases, relief of proptosis and optic nerve compression are the primary goals of surgery, rather than gross-total resection, which may have high morbidity or be unachievable. In cases with significant residual intraconal tumor, orbital bone removal alone may not be sufficient to reduce proptosis.

Analysis of the far-medial transoral endoscopic approach to the infratemporal fossa

OBJECTIVES/HYPOTHESIS

To demonstrate anatomic relationships of the far-medial transoral endoscopic assisted approach (FMT-EAA) to the infratemporal fossa (ITF) and define the corridor dimensions, surgical freedom, and limitations associated with this approach.

STUDY DESIGN

Cadaveric study.

METHODS

Twenty ITFs (10 specimens) were dissected with the assistance of 0 °, 30 °, and 45 ° rod-lens endoscopes. Image guidance was used to confirm and measure the corridors' structural boundaries and document the anatomical relationships encountered in this approach.

RESULTS

Access to the ITF via the FMT-EAA can be divided into two secondary surgical corridors: the superomedial and inferolateral triangles, each of which provides access to different areas. The superomedial triangle is bounded medially by the lateral pterygoid plate and posterolateral maxillary sinus wall, superiorly by the greater sphenoid wing, and inferolaterally by the lateral pterygoid muscle. The inferolateral triangle is bounded superiorly by the lower head of the lateral pterygoid muscle, inferiorly by the medial pterygoid muscle, and laterally by the mandible. Using a standard 19-mm endoscope, the FMT-EAA achieves a mean surgical freedom of 231 mm and 161 mm in the vertical and horizontal planes, respectively.

CONCLUSIONS

FMT-EAA adequately exposes critical structures of the ITF. This technique is a viable option for the management of selected ITF lesions, either alone or in combination with alternative minimally invasive approaches to the region.

LEVEL OF EVIDENCE

NA Laryngoscope, 128:2273-2281, 2018.

Defining the lateral limits of the endoscopic endonasal transtuberculum transplanum approach: anatomical study with pertinent quantitative analysis

OBJECTIVE

The extended endoscopic endonasal transtuberculum transplanum approach is currently used for the surgical treatment of selected midline anterior skull base lesions. Nevertheless, the possibility of accessing the lateral aspects of the planum sphenoidale could represent a limitation for such an approach. To the authors' knowledge, a clear definition of the eventual anatomical boundaries has not been delineated. Hence, the present study aimed to detail and quantify the maximum amount of bone removal over the planum sphenoidale required via the endonasal pathway to achieve the most lateral extension of such a corridor and to evaluate the relative surgical freedom.

METHODS

Six human cadaveric heads were dissected at the Laboratory of Surgical NeuroAnatomy of the University of Barcelona. The laboratory rehearsals were run as follows: 1) preliminary predissection CT scans, 2) the endoscopic endonasal transtuberculum transplanum approach (lateral limit: medial optocarotid recess) followed by postdissection CT scans, 3) maximum lateral extension of the transtuberculum transplanum approach followed by postdissection CT scans, and 4) bone removal and surgical freedom analysis (a nonpaired Student t-test). A conventional subfrontal bilateral approach was used to evaluate, from above, the bone removal from the planum sphenoidale and the lateral limit of the endonasal route.

RESULTS

The endoscopic endonasal transtuberculum transplanum approach was extended at its maximum lateral aspect in the lateral portion of the anterior skull base, removing the bone above the optic prominence, that is, the medial portion of the lesser sphenoid wing, including the anterior clinoid process. As expected, a greater bone removal volume was obtained compared with the approach when bone removal is limited to the medial optocarotid recess (average 533.45 vs 296.07 mm2; p < 0.01). The anteroposterior diameter was an average of 8.1 vs 15.78 mm, and the laterolateral diameter was an average of 18.77 vs 44.54 mm (p < 0.01). The neurovascular contents of this area were exposed up to the insular segment of the middle cerebral artery. The surgical freedom analysis revealed a possible increased lateral maneuverability of instruments inserted in the contralateral nostril compared with a midline target (average 384.11 vs 235.31 mm2; p < 0.05).

CONCLUSIONS

Bone removal from the medial aspect of the lesser sphenoid wing, including the anterior clinoid process, may increase the exposure and surgical freedom of the extended endoscopic endonasal transtuberculum transplanum approach over the lateral segment of the anterior skull base. Although this study represents a preliminary anatomical investigation, it could be useful to refine the indications and limitations of the endoscopic endonasal corridor for the surgical management of skull base lesions involving the lateral portion of the planum sphenoidale.

Endoscopic Approach to Remove Intra-extracranial Tumors in Various Skull Base Regions: 10-year Experience of a Single Center

Background:

Some problems have been found in the usually adopted combined approach for the removal of intra-extracranial tumors in skull base. Herein, we described a pure endoscopic transnasal or transoral approach (ETA) for the removal of intra-extracranial tumors in various skull base regions.

Methods:

Retrospectively, clinical data, major surgical complications, pre- and postoperative images, and follow-up information of a series of 85 patients with intra-extracranial tumors in various skull base regions who were treated by surgery via ETA in our skull base center during the past 10 years were reviewed and analyzed.

Results:

Gross total tumor removal was achieved in 80/85 cases (94.1%) in this study. All 37 cases with tumors in anterior skull base and all 14 cases with tumors in jugular foramen received total tumor removal. Thirteen and three cases with tumors in clivus received total and subtotal tumor removal, respectively. Total and subtotal tumor removal was performed for 16 cases and 2 cases in lateral skull base, respectively. The complications in this study included: cerebrospinal fluid leakage (n = 3), meningitis (n = 3), and new cranial nerve deficits (n = 3; recovered in 3 months after surgery). In the follow-up period of 40–151 months (median: 77 months), seven patients (8.8%) out of the 80 cases of total tumor removal experienced recurrence.

Conclusions:

Complete resection of intra-extracranial growing tumors in various skull base regions can be achieved via the pure ETA in one stage in selected cases. Surgical procedure for radical removal of tumors is feasible and safe.

An Innovate Robotic Endoscope Guidance System for Transnasal Sinus and Skull Base Surgery: Proof of Concept

Objective  Advanced transnasal sinus and skull base surgery remains a challenging discipline for head and neck surgeons. Restricted access and space for instrumentation can impede advanced interventions. Thus, we present the combination of an innovative robotic endoscope guidance system and a specific endoscope with adjustable viewing angle to facilitate transnasal surgery in a human cadaver model. Materials and Methods  The applicability of the robotic endoscope guidance system with custom foot pedal controller was tested for advanced transnasal surgery on a fresh frozen human cadaver head. Visualization was enabled using a commercially available endoscope with adjustable viewing angle (15-90 degrees). Results  Visualization and instrumentation of all paranasal sinuses, including the anterior and middle skull base, were feasible with the presented setup. Controlling the robotic endoscope guidance system was effectively precise, and the adjustable endoscope lens extended the view in the surgical field without the common change of fixed viewing angle endoscopes. Conclusion  The combination of a robotic endoscope guidance system and an advanced endoscope with adjustable viewing angle enables bimanual surgery in transnasal interventions of the paranasal sinuses and the anterior skull base in a human cadaver model. The adjustable lens allows for the abandonment of fixed-angle endoscopes, saving time and resources, without reducing the quality of imaging.

Transorbital endoscopic approach for exposure of the sylvian fissure, middle cerebral artery and crural cistern: an anatomical study

BACKGROUND

The availability of minimal access instrumentation and endoscopic visualization has revolutionized the field of minimally invasive skull base surgery. The transorbital endoscopic approach using an eyelid incision has been proposed as a new minimally invasive technique for the treatment of skull base pathology, mostly extradural tumors. Our study aims to evaluate the anatomical aspects and potential role of the transorbital endoscopic approach for exposure of the sylvian fissure, middle cerebral artery and crural cistern.

METHODS

An anatomical dissection was performed in four freshly injected cadaver heads (8 orbits) using 0- and 30-degree endoscopes. First, an endoscopic endonasal medial orbital decompression was done to facilitate medial retraction of the orbit. An endoscopic transorbital approach through an eyelid incision, with drilling of the posterior wall of the orbit and lesser sphenoidal wing, was then performed to expose the sylvian fissure and crural cisterns. A stepwise anatomical description of the approach and visualized anatomy is detailed.

RESULTS

A superior eyelid incision followed by orbital retraction provided a surgical window of approximately 1.2 cm (range 1.0-1.5 cm) for endoscopic transorbital dissection. The superior (SOF) and inferior (IOF) orbital fissures represent the medial limits of the approach and are identified in the initial part of the procedure. Drilling of the orbital roof (lateral and superior to the SOF), greater sphenoidal wing (lateral to the SOF and IOF) and lesser sphenoidal wing exposed the anterior and middle fossa dura. A square-shaped dural opening provided visualization of the posterior orbital gyri, sylvian fissure and temporal pole. Intradural dissection allowed exposure of the sphenoidal portion of the sylvian fissure, M1, MCA bifurcation and M2 branches and lenticulostriate perforators. Dissection of the medial aspect of the sylvian and carotid cisterns with a 30-degree endoscope allowed exposure of the mesial temporal lobe and crural cistern.

CONCLUSIONS

The transorbital endoscopic approach allows successful exposure of the sphenoidal portion of the sylvian fissure and M1 and M2 segments of the middle cerebral artery. Angled endoscopes may provide visualization of the mesial temporal lobe and crural cistern. Although our anatomical study demonstrates the feasibility of intradural dissection and closure via an endoscopic transorbital approach, further studies are necessary to evaluate its role in the clinical scenario.

Management of Cavernous Sinus Involvement in Sinonasal and Ventral Skull Base Malignancies

Cavernous sinus (CS) involvement by sinonasal and ventral skull base malignancies is infrequently encountered in neurosurgical practice. Despite advancements in skull base microneurosurgery and endoscopic techniques, detailed knowledge and experience of the surgical management of these lesions are limited. This article elaborates on surgical strategies and approaches for CS involvement of malignant ventral skull base tumors. The article discusses the indications, techniques, nuances, advantages, limitations, and complications of minimally invasive CS biopsy, transcranial microscopic, and transfacial endoscopic approaches to the CS using illustrative diagrams and operative videos. The principles and nuances of a high-flow cerebral revascularization procedure are mentioned.

[Choosing an anterior midline approach to skull base tumors]

The purpose of this review is to analyze used anterior midline approaches to the skull base, identify their advantages and disadvantages, and, after reviewing the literature data, submit a developed algorithm for choosing an optimal approach to the approval of colleagues. We provide brief information on approach techniques, indications and contraindications, and advantages and disadvantages as well as analyze international experience of using the discussed approaches. On the basis of literature data, we have developed a prototype algorithm for choosing an optimal approach to medial tumors of the anterior skull base. The situation of choosing an optimal approach reveals the absence of a clear understanding of the boundaries between capabilities and limitations of approaches. To solve this problem, an original prospective study is required.

Minimally invasive endoscopic resection for the treatment of sinonasal malignancy: the outcomes and risk factors for recurrence

Purpose

The role of minimally invasive endoscopic resection (MIER) in the treatment of sinonasal malignancy is controversial. Herein, we performed a retrospective review of a large case series of sinonasal malignancy patients treated with MIER aimed at evaluating the outcomes and identifying the risk factors for recurrence.

Methods

Patients with sinonasal malignancy who underwent MIER from March 2000 to May 2015 were enrolled, and their clinical data were collected. The clinical outcomes were evaluated by determining the 5-year overall survival (OS) and disease-free survival (DFS). The predictive factors for survival and potential independent risk factors for recurrence were explored.

Results

A total of 120 patients were enrolled, including 62 males and 58 females. The mean follow-up period was 51.4 (95% confidence interval: 44.0–59.1) months. The most frequent histological type was mucosal malignant melanoma. The positive margin rate was 19.2% (23/120). Seventy-one patients had the safety anatomic plane (SAP). Age ≥50 years, nodal metastasis, and not having the SAP were found to be predictive factors for survival, and absence of SAP was found to be an independent risk factor for recurrence.

Conclusion

Our study indicated that MIER is an effective and safe surgical procedure in appropriately selected patients. Tumor resection with a safety anatomic boundary is likely to lead to improved survival and decreased recurrence. However, a larger sample and long-term prospective observation are still required to establish the role of MIER in treatment of sinonasal malignancy.

Endoscopic surgery of a sinonasal inverted papilloma: Surgical strategy, follow-up, and recurrence rate

BACKGROUND

Sinonasal inverted papilloma (SNIP) is noted for its high rate of recurrence and malignant transformation. Although many clinical studies have demonstrated the effectiveness of the endoscopic approach for SNIP, the surgical strategy has been the subject of much debate.

OBJECTIVE

To evaluate the effectiveness of the endoscopic endonasal approach in SNIP.

METHODS

A systematic review of patients with a diagnosis of SNIP and who had surgery at our institution from June 2005 to March 2013 was performed. All the patients who had postoperative follow-up for >2 years were enrolled. Each case was categorized into one of four stages as reported by Krouse. Demographic and tumor date, operative approach, complications, and recurrence rates were collected.

RESULTS

A total of 125 patients were included in this study. There were 17 patients in stage 1, 40 in stage 2, 57 in stage 3, and 11 in stage 4. The overall recurrence rate was 8.0%. There was no significant difference in recurrence among the stages (all p > 0.05). Recurrence after endoscopic endonasal approach (8.4%) and a combined endoscopic and open exposure procedure (5.6%) were not significantly different (p > 0.05). The recurrence rate was significantly (p < 0.05) higher in patients with revision (15.6%) than in patients in the primary cases (3.8%). A common site of tumor origin was recorded to be from the maxillary sinus (40.2%). Twenty percent of recurrences were observed up to 5 years after surgery.

CONCLUSION

Endoscopic surgery may be preferred for treating SNIP. The elevated recurrence rate after revision emphasized the significance of the first surgery. We encourage a follow-up period of at least 5 years.

Transnasal endoscopic partial maxillectomy: Operative nuances and proposal for a comprehensive classification system based on 1378 cases

BACKGROUND

Despite the development of functional endoscopic endonasal surgery, there are still areas of the maxillary sinus that remain technically difficult to access using a standard middle meatal antrostomy as well as deep-seated skull base lesions requiring expanded transmaxillary approaches.

METHODS

All patients who underwent transnasal endoscopic partial maxillectomy (TEPM) in a single institution from 2000 to 2014 were retrospectively reviewed. The TEPM was classified into 5 types according to the anatomic structures progressively removed and to the access provided.

RESULTS

The TEPM was performed in 1378 patients for the management of: inflammatory diseases in 513 cases (37%), benign sinonasal tumors in 425 cases (31%), skull base malignancies in 285 cases (21%), and as a corridor to address deep-seated skull base lesions in 155 cases (11%).

CONCLUSION

The TEPM is a stepwise approach offering increasing access that can be tailored to different maxillary, sinonasal, and skull base pathologies with minimal morbidity for patients. © 2016 Wiley Periodicals, Inc. Head Neck 39: 754-766, 2017.

Infraorbital nerve transposition to expand the endoscopic transnasal maxillectomy

BACKGROUND

The infraorbital nerve (ION) is a terminal branch of the maxillary nerve (V2) providing sensory innervation to the malar skin. It is sometimes necessary to sacrifice the ION and its branches to obtain adequate maxillary sinus exposure for radical resection of sinonasal tumors. Consequently, patients suffer temporary or permanent paresthesia, hypoestesthia, and neuralgia of the face. We describe an innovative technique used for preservation of the ION while removing the anterior, superior, and lateral walls of the maxillary sinus through a medial endoscopic transnasal maxillectomy.

METHODS

All patients who underwent transnasal endoscopic maxillectomy with ION transposition in our institute were retrospectively reviewed.

RESULTS

Two patients were identified who had been treated for sinonasal cancers using this approach. No major complications were observed. Transient loss of ION function was observed with complete recovery of skin sensory perception within 6 months of surgery. One patient referred to a mild permanent anesthesia of the upper incisors. No diplopia or enophthalmos were encountered in any of the patients.

CONCLUSION

The ION transposition is useful for selected cases of benign and malignant sinonasal tumors that do not infiltrate the ION itself but involve the surrounding portion of the maxillary sinus. Anatomic preservation of the ION seems to be beneficial to the postoperative quality of life of such patients.

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.

Management Strategies for Skull Base Inverted Papilloma

Objective

Inverted papilloma attached to the ventral skull base presents a surgical dilemma because surgical removal of the bony pedicle is critical to decrease risk of recurrence. The objective of this study is to evaluate the effectiveness of endoscopic management of skull base inverted papilloma.

Study Design

Case series with planned data collection.

Setting

Tertiary medical center.

Subjects

Patients with skull base inverted papilloma.

Methods

Over 7 years, 49 patients with skull base inverted papilloma were referred for surgical resection. Demographics, operative technique, pathology, complications, recurrence, and postoperative follow-up were evaluated.

Results

Average age at presentation was 57 years. Twenty-six patients (53%) had prior attempts at resection elsewhere, and 5 had squamous cell carcinoma (SCCA) arising in an inverted papilloma. Six patients (12%) suffered major complications, including skull base osteomyelitis in 2 previously irradiated patients, cerebrospinal fluid leak with pneumocephalus (n = 1), meningitis (n = 1), invasive fungal sinusitis (n = 1), and cerebrovascular accident (n = 1). The mean disease-free interval was 29 months (range, 10-78 months). One patient with SCCA recurred in the nasopharynx (overall 2% recurrence rate). He is disease-free 3 years following endoscopic nasopharyngectomy. Three patients with SCCA had endoscopic resection of the skull base, while 1 subject with inverted papilloma pedicled on the superior orbital roof had an osteoplastic flap in conjunction with a Draf III procedure. All others received endoscopic resection.

Conclusions

Removal of the bony pedicle resulted in excellent local control of skull base inverted papillomas. Our experience demonstrates that disease eradication with limited morbidity is attainable with this approach.

Systematic Review of the Effectiveness of Perioperative Prophylactic Antibiotics for Skull Base Surgeries

Background

Perioperative antibiotics are commonly used in endoscopic skull base surgeries as prophylaxis for infectious complications, e.g., meningitis. The role of perioperative prophylactic antibiotics in endoscopic sinus surgery is unclear, and the routine use of prophylactic antibiotics in endoscopic skull base surgery is also highly debated. Currently, there is no formal recommendation for perioperative antibiotic use in skull base surgery, and regimens vary greatly from one institution to the next.

Objective

To assess perioperative antibiotics as prophylaxis against infectious complications in patients who underwent endoscopic skull base surgery.

Data Sources

PubMed, Ovid EMBASE, and the Cochrane Library.

Methods

A systematic review that examined perioperative antibiotic use in endoscopic skull base and craniofacial surgeries was conducted. Inclusion criteria were prospective or retrospective study design and clinical trials related to the use of antibiotics within 30 days of skull base surgery. End points included infectious complications such as (1) meningitis and (2) sinusitis.

Results

A total of 2543 articles were identified by the initial search, and 5 articles met inclusion criteria. The five eligible trials were all observational and involved different types of skull base surgical procedures and antibiotic regimens.

Conclusions

Despite institutional variability in antibiotic regimens, meningitis rarely occurs after skull base procedures and seems to be encountered most frequently in open craniofacial surgeries. A systematic review revealed a limited number of published studies, all observational in study design, which precluded a formal meta-analysis. A novel large-scale randomized-controlled clinical trial is needed to evaluate antibiotic selection and need in endoscopic skull base surgery.

Endonasal Endoscopic Surgery in the Management of Sinonasal and Anterior Skull Base Malignancies

Sinonasal malignancies represent a rare subset of tumors with a wide variety of histopathologic diagnoses and overall poor prognosis. These tumors tend to have an insidious onset with non-specific symptoms which often leads to delayed diagnosis and advanced local disease at presentation. The principal goal of surgery is to obtain a negative margin resection. Open craniofacial techniques are well established in the management of sinonasal malignancies and remain the treatment of choice for many advanced tumors. Over the past couple of decades, there has been tremendous application of endoscopic techniques to skull base pathologies including sinonasal malignancies. For selected cases, endonasal endoscopic techniques can be performed with curative intent and reduced surgical morbidity and mortality. Here we discuss principles of surgical management of sinonasal malignancies, review the techniques of endonasal endoscopic resection of sinonasal malignancies, and highlight the importance of pathology in the multi-disciplinary management of patients with these complex lesions.

Role of endoscopic surgery in the management of sinonasal and skull base schwannomas

BACKGROUND

The purpose of this study was to report our experience with the endoscopic management of sinonasal schwannomas, analyzing the advantages, limitations, and outcomes of the technique.

METHODS

A retrospective analysis was carried out on 11 patients treated endoscopically between 2000 and 2014 at a single institution.

RESULTS

Eight patients underwent an exclusive endoscopic endonasal approach, whereas, in 3 patients, an osteoplastic flap was combined because of massive or lateral frontal sinus involvement. The tumor extended into the orbit in 5 cases, and involved the skull base in 5 patients who required a concomitant endoscopic duraplasty. No evidence of disease was observed in 10 patients after a mean follow-up of 90.1 months (range, 14-189 months). One patient was alive with persistence of disease, although asymptomatic.

CONCLUSION

The endoscopic endonasal approach is a valid alternative for the vast majority of sinonasal schwannomas with minimal morbidity for the patient. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2074-E2082, 2016.