Automated Surgical Approach Planning for Complex Skull Base Targets: Development and Validation of a Cost Function and Semantic At-las.

Successful multidisciplinary treatment of skull base pathology requires precise preoperative planning. Current surgical approach (pathway) selection for these complex procedures depends on an individual surgeon's experiences and background training. Because of anatomical variation in both normal tissue and pathology (eg, tumor), a successful surgical pathway used on one patient is not necessarily the best approach on another patient. The question is how to define and obtain optimized patient-specific surgical approach pathways? In this article, we demonstrate that the surgeon's knowledge and decision making in preoperative planning can be modeled by a multiobjective cost function in a retrospective analysis of actual complex skull base cases. Two different approaches- weighted-sum approach and Pareto optimality-were used with a defined cost function to derive optimized surgical pathways based on preoperative computed tomography (CT) scans and manually designated pathology. With the first method, surgeon's preferences were input as a set of weights for each objective before the search. In the second approach, the surgeon's preferences were used to select a surgical pathway from the computed Pareto optimal set. Using preoperative CT and magnetic resonance imaging, the patient-specific surgical pathways derived by these methods were similar (85% agreement) to the actual approaches performed on patients. In one case where the actual surgical approach was different, revision surgery was required and was performed utilizing the computationally derived approach pathway.

Quantitative Analysis of Transnasal Anterior Skull Base Approach: Report of Technology for Intraoperative Assessment of Instrument Motion.

OBJECTIVE: To develop a method to measure intraoperative surgical instrument motion. This model will be applicable to the study of surgical instrument kinematics including surgical training, skill verification, and the development of surgical warning systems that detect aberrant instrument motion that may result in patient injury. DESIGN: We developed an algorithm to automate derivation of surgical instrument kinematics in an endoscopic endonasal skull base surgery model. Surgical instrument motion was recorded during a cadaveric endoscopic transnasal approach to the pituitary using a navigation system modified to record intraoperative time-stamped Euclidian coordinates and Euler angles. Microdebrider tip coordinates and angles were referenced to the cadaver's preoperative computed tomography scan allowing us to assess surgical instrument kinematics over time. A representative cadaveric endoscopic endonasal approach to the pituitary was performed to demonstrate feasibility of our algorithm for deriving surgical instrument kinematics. CONCLUSIONS: Technical feasibility of automatically measuring intraoperative surgical instrument motion and deriving kinematics measurements was demonstrated using standard navigation equipment.

Learning curve for use of the sonopet ultrasonic aspirator in endoscopic dacryocystorhinostomy.

PURPOSE: The Sonopet Ultrasonic Aspirator is a surgical tool that uses low-frequency ultrasonic vibrations to fragment tissue while simultaneously irrigating and aspirating the surgical field. This technology is becoming more widely used in orbital, lacrimal, neurological, and skull base surgery, but few studies have examined the learning curve associated with adoption of this technology. We present our surgical learning curve, pearls, and pitfalls using the newest generation Sonopet Ultrasonic Aspirator Universal handpiece in endoscopic dacryocystorhinostomy (eDCR) surgery. METHODS: Retrospective chart review of consecutive eDCR surgeries performed by a single surgeon adopting the Sonopet Universal handpiece. Data collected include demographic information, indications for surgery, surgical time, intraoperative findings, anatomic and functional results, and complications. RESULTS: Twenty-six eDCR surgeries in 20 patients were performed from October 2011 - May 2013. Most patients were female (85.7%) with mean age 53.6 years (range 4-84) and mean follow up of 378 days (range 7-761). For routine unilateral and bilateral surgeries, surgery time decreased by 36.4% and 33.9% before reaching a plateau of 67.2 and 80.7 minutes per case, respectively. Mean surgery time for non-sequential unilateral complex cases was 85.1 minutes, which did not vary significantly over the learning curve. We achieved 100% anatomic success and 84.6% functional success. CONCLUSIONS: The Sonopet Ultrasonic Aspirator Universal handpiece can be used safely and effectively for eDCR surgery. A significant learning curve exists for adoption of this technology. Appropriate handpiece tip selection and machine setting adjustments are crucial for successful adoption of this technology and avoidance of complications.

Reducing annotating load: Active learning with synthetic images in surgical instrument segmentation.

Accurate instrument segmentation in the endoscopic vision of minimally invasive surgery is challenging due to complex instruments and environments. Deep learning techniques have shown competitive performance in recent years. However, deep learning usually requires a large amount of labeled data to achieve accurate prediction, which poses a significant workload. To alleviate this workload, we propose an active learning-based framework to generate synthetic images for efficient neural network training. In each active learning iteration, a small number of informative unlabeled images are first queried by active learning and manually labeled. Next, synthetic images are generated based on these selected images. The instruments and backgrounds are cropped out and randomly combined with blending and fusion near the boundary. The proposed method leverages the advantage of both active learning and synthetic images. The effectiveness of the proposed method is validated on two sinus surgery datasets and one intraabdominal surgery dataset. The results indicate a considerable performance improvement, especially when the size of the annotated dataset is small. All the code is open-sourced at: https://github.com/HaonanPeng/active_syn_generator.

Multiportal Retrograde Endoscopy to Enhance Surgical Target Visualization: A Pilot Study.

Objective Current transnasal endoscopic techniques for sinus and skull base surgery use a single endoscope to provide visualization from one perspective curtailing depth perception and compromising visualization of the instrument-target interface. The view can be blocked by instruments, and collisions between instruments often occur. The objective of this study was to investigate the use of multiportal retrograde endoscopy to provide more accurate manipulation of the surgical target. Design Maxillary antrostomy and frontal sinusotomy were performed on three different cadavers by three different surgeons. A zero-degree rigid endoscope was introduced through the nose for the standard transnasal approach. A flexible endoscope was introduced transorally, directed past the palate superiorly, and then flexed 180 degrees for the retrograde view. Videos of the standard transnasal view from the rigid endoscope and retrograde view from the flexible endoscope were recorded simultaneously. Results All surgeries were able to be performed with dual-screen viewing of the standard and retrograde view. The surgeons noted that they utilized the retrograde view to adjust the location of ends/tips of their instruments. Four surgeons reviewed the videos and individually agreed that the visualization achieved provided a perspective otherwise not attainable with rigid transnasal endoscopy alone. Conclusion High-quality visualization of surgical targets such as the frontal or maxillary ostia can be challenging with rigid endoscopes alone. Multiportal retrograde endoscopy provides proof of concept that additional views of a surgical target can be achieved. Additional work is needed to further develop indications, techniques, and generalizability to targets beyond those investigated here.

Operative Technique and Complication Management in a Case of Giant Esthesioneuroblastoma Resected by a Combined Transcranial and Endonasal Endoscopic Approach: Technical Case Report.

BACKGROUND AND IMPORTANCE: Esthesioneuroblastoma (ENB) is a rare anterior skull base tumor derived from olfactory epithelium. There are very few operative videos in the literature demonstrating the surgical resection techniques for giant ENB because of their rarity and complexity. In this technical report, we demonstrate the microsurgical resection of a very large and complex high-grade ENB, initially deemed unresectable, through a bifrontal craniotomy and extended subfrontal approach combined with an endonasal endoscopic approach. CLINICAL PRESENTATION: A 34-year-old woman presented with headaches, nasal congestion, and bloody nasal drainage. MRI showed a large nasal cavity mass with extension into the anterior cranial fossa and bifrontal lobes. There was significant bifrontal edema causing headaches and abutting the optic nerves. Initial management with surgical resection was offered to the patient for local tumor control and to preserve her vision. A combined bifrontal craniotomy and endonasal transsphenoidal approach was used for resecting this giant tumor. After achieving gross total resection, we reconstructed the anterior skull base in layers. She developed several postoperative complications which were appropriately managed. CONCLUSION: We demonstrate the surgical resection of a giant ENB through a combined transcranial and endonasal endoscopic approach. We discuss the several postoperative complications in this complex case and the lessons learned.

Five-year outcome of a staged giant Shamblin type III carotid body tumor excision.

Giant carotid body tumors, defined as those >8 cm in size, are extremely rare. Definitive surgical management is a complex undertaking because these large tumors tend to have grown to envelop cranial nerves and the carotid artery, and few data exist regarding the long-term outcomes for these patients. We present the case of a patient with bilateral giant carotid body tumors who underwent staged embolization and excision of a >10-cm carotid body tumor. After 5 years of follow-up, we demonstrated that elective open repair can provide long-term symptomatic relief. We describe and illustrate the crucial steps and considerations regarding the excision of complex Shamblin type III carotid body tumors.

The "Crista Ovale": A Reliable Anatomical Landmark in Transorbital Endoscopic Approaches to the Middle Cranial Fossa.

BACKGROUND: Transorbital endoscopic approaches (TOEAs) have emerged as adjunct and alternatives for accessing the middle cranial fossa (MCF). Nuances of the skull base anatomy from a ventral transorbital endoscopic viewpoint remain to be fully described. OBJECTIVE: To assess the anatomy of the "crista ovale" (COv), described transcranially as the midsubtemporal ridge (MSR), from a ventral transorbital perspective and evaluate its role as a landmark in TOEA to the MCF. METHODS: Lateral TOEAs to the MCF were performed in 20 adult cadaveric heads (40 sides). The presence of the COv/MSR was evaluated under endoscopic visualization. Anatomic relationships between COv/MSR and surrounding structures were assessed. The presence of COv/MSR was also examined in 30 cadaveric head computed tomography (CT) scans (60 sides). RESULTS: The COv/MSR was identified in 98% (39/40) of sides at the MCF, as 1 of 4 major configurations. The COv/MSR was found anterolateral to the foramen ovale and foramen spinosum (mean distance: 9.2 ± SD 2.4 mm and 12.3 ± SD 2.6 mm, respectively) directly anterior or anteromedial to the petrous apex (mean distance: 26.2 ± SD 2.6 mm) and at a mean 47.6 ± SD 4.7 mm from the approach's surgical portal. It was recognized in 95% (57/60) of CT scans. CONCLUSION: The COv/MSR can be readily identified during TOEA to the MCF and on CT. It serves as a reliable landmark to localize the foramen ovale, foramen spinosum, and petrous apex. Further studies may confirm its surgical significance in transorbital endoscopic procedures.

Frontal Sinus Fractures.

Management of frontal sinus fractures is controversial with no universally accepted treatment protocol. Goals of management are to correct aesthetic deformity, preserve sinus function when it is deemed salvageable, prevent sequela related to the injury, and minimize complications associated with intervention. Studies suggest that frontal sinus injuries, including disruption of the nasofrontal outflow tract (NFOT), can be managed nonoperatively in many cases. Advances in the utilization of endoscopic techniques have led to an evolution in management that reduces the need for open procedures, which have increased morbidity compared with endoscopic approaches. We employ a minimally disruptive protocol that treats the majority of fractures nonoperatively with serial clinical and radiographic examinations to assess for sinus aeration. Surgical intervention is reserved for the most severely displaced and comminuted posterior table fractures and unsalvageable NFOTs utilizing endoscopic approaches whenever possible.

Computer-Aided Rhinoplasty Using a Novel "navigated" Nasal Osteotomy Technique: A Pilot Study.

OBJECTIVE: To describe the surgical technique of navigation-guided nasal osteotomies and assess feasibility of this technique for treating complex nasal bone deformities in reconstructive rhinoplasty. METHODS: A retrospective chart review was performed in order to identify patients who underwent computer-aided rhinoplasty from August 2014 to February 2017. Inclusion criteria were nasal bone deformities on computed-tomography (CT) that correlated with specific nasal complaints. All patients underwent computer-aided rhinoplasty with navigation-guided nasal osteotomies using a standard navigation system. Osteotomies were performed using real-time visualization on the navigation screen. Additional soft tissue procedures were performed as needed. Medical records were reviewed for presenting symptoms, radiologic and operative findings, and postoperative course. Cosmetic outcomes were subjectively based on patients' standard 6-view photo-documentation from pre- and post-operative timepoints. RESULTS: Twenty-one patients were included in the study; 8 were revision cases and 3 had mild-to-moderate hemifacial microsomia. Fifteen were completely closed procedures. No cases were opened because of inadequate visualization or difficulty accessing bony pathology. Mean (range) follow up was 98.6 (6-559) days. There were no intra-operative complications, unplanned admissions or re-admissions, or iatrogenic cosmetic complications (ie, "inverted V" or "saddle nose" deformities). Two patients required revision. One was after suffering nasal trauma within 4 weeks of initial rhinoplasty. The second underwent further correction of a deformity that required a costochondral graft. Both experienced good final results. CONCLUSIONS: Computer-aided rhinoplasty is safe and feasible for treating complex nasal deformities using standard navigation systems.

Factors Associated with Ocular Injury in Orbital Fracture Patients: Who Requires Urgent Ophthalmic Evaluation?

Importance: Create validated criteria to identify orbital fracture patients at higher risk for significant ocular injuries. Objective: Determine history and physical examination findings in orbital fracture patients who are associated with ocular injury and warrant urgent assessment by an ophthalmologist. Design, Setting, and Participants: Retrospective chart review of 535 adult orbital fracture patients evaluated at a Level I emergency department between 2014 and 2017, without prior history of orbital fracture, ocular injury, or ocular/orbital surgery. Main Outcomes and Measure: Presence of ocular injury. Results: In total, 195 (36%) patients had an ocular injury. Those with and without ocular injury were compared in a multivariate logistic regression model including demographics, fracture characteristics, injury mechanism, and physical examination findings. Visual acuity change, radiographic retrobulbar hemorrhage, abnormal pupillary reaction, and inability to open the injured eye all had significant associations with ocular injury when other findings were controlled. Conclusion: This study shows a significant association between ocular injury and visual acuity change, retrobulbar hemorrhage, abnormal pupillary reaction, and inability to open the injured eye. These factors can help triage when to obtain an urgent ophthalmology consult.

Endoscopic Orbital and Periorbital Approaches in Minimally Disruptive Skull Base Surgery.

Endoscopic surgery of the orbit, periorbital region, and adjacent areas of the anterior and middle cranial fossae and brain has gained significant popularity over the last decade. These procedures are now being used at multiple institutions internationally with a success and safety record that has been demonstrated to be at par with or better than other techniques. The approaches provide minimally disruptive, scarless access to regions that previously required extensive open operations with significant retraction of critical neurovascular structures leading to prolonged morbidity and hospitalization. This paper will describe the basic techniques of these approaches, how they can be used alone or in multiportal (para- and contraportal) technique and guide the reader to resources for further learning.

Quantifying Eye Alignment in Orbital Fracture Patients: The Digital Hess Screen.

Background: Quantifying diplopia to determine management and track outcomes for orbital fracture patients is vital for standardization between visits, physicians, and coordination among the multiple specialties that manage these patients. However, standardization is challenging, as diplopia is often reported subjectively. This study sought to describe the utility of the digital Hess screen in patients with orbital fractures compared with a control group. Materials and Methods: A prospective pilot study was designed in which adult patients who presented with orbital fractures between November 2017 and January 2019 without prior history of orbital pathology were recruited. Subjects underwent digital Hess screen testing, in which they wore anaglyph glasses and aligned targets on a computer screen to quantify static eye alignment. The degree of any eye misalignment was analyzed and compared with controls. Results: Ninety-one patients and 35 controls were enrolled. All participants were able to complete the digital Hess screen. Average cumulative deviation score of orbital fracture patients within 1 month of injury was 0.65°, compared with 0.28° in controls. This was a statistically significant difference (p < 0.01, 95% confidence interval -0.18 to 0.18). Conclusion: The Hess screen has been used to quantify phoria as a correlate of eye alignment and diplopia, but older versions were cumbersome and difficult to analyze. This study is the first to report on using the digital Hess screen to quantify phoria in orbital fracture patients and provides a more concise and standardized means to track clinical and surgical outcomes of eye alignment.

Modiolar rotational cheiloplasty: Addressing the central oval in facial paralysis.

OBJECTIVES/HYPOTHESIS: Current static reanimation of the midface fails to provide adequate functional and aesthetic improvement; there is a need for more effective static correction of the ptotic midface. Our objective herein was to describe a novel method of static midface suspension that produces improved functional and aesthetic outcomes compared to previous techniques. Specifically, our goal was to describe the technique of alar and oral commissure repositioning via modiolar rotational cheiloplasty with alar base transposition, and gingivobuccal sulcoplasty. STUDY DESIGN: Retrospective case series. METHODS: We retrospectively reviewed the results of a series of adult patients desiring surgical intervention for paralysis of the central oval of the face at a tertiary care referral center. We present our technique of modiolar rotational cheiloplasty first with an example case, including subjective outcomes reported by the patient and objective improvements in facial appearance using Massachusetts Eye and Ear Infirmary Facial Assessment by Computer Evaluation Program (MEEI FACE-Gram) software, then demonstrate long-term outcomes from the series. RESULTS: Clinically, patients noted subjective improvement in drooling, buccal stasis of food, dysarthria, nasal obstruction, and overall appearance. Patients with significant atrophy and lateral displacement of the lower lip underwent concomitant wedge resection, which further improved the symmetry and position of the lips. The MEEI FACE-Gram software demonstrated objective improvement in symmetry of smile and position of the philtrum and nasal base in an example case. CONCLUSIONS: Modiolar rotational cheiloplasty with alar base transposition is an effective and efficient static procedure for midface palsy that improves both function and appearance. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:2262-2268, 2019.

Transorbital Approach for Improved Access in the Management of Paranasal Sinus Mucoceles.

Introduction Paranasal sinus mucoceles result from obstruction of mucous glands resulting in a cystic fluid collection that expands and encroaches upon surrounding structures. Transnasal endoscopic marsupialization has largely replaced open resection. However, mucoceles located in the orbital region or the lateral frontal sinus continue to be difficult to approach via the transnasal approach alone and often require additional approaches, such as the frontal trephine. This study sought to investigate the feasibility of the transorbital technique as an adjunct to traditional transnasal approaches in the management of paranasal sinus mucoceles. Methods A retrospective case series of paranasal sinus mucoceles approached with a transorbital technique from a tertiary care center. Results From 2008 to 2016, 17 patients were treated with a transorbital approach for 20 mucoceles. Of note, 24% of the patients in our series had undergone previous surgical management of the mucocele (nontransorbital approach), representing revision cases. Most mucoceles involved the frontal sinus (82%). The total complication rate was 6%. We observed no new or worsened diplopia, ptosis, or permanent visual loss. Recurrence rate was 6%. Conclusions The endoscopic transorbital approach is a feasible complement to transnasal approaches for treatment of mucoceles located in technically challenging locations. We have demonstrated that transorbital approaches can be performed with no resultant orbital damage, visual change, ptosis, or permanent diplopia. While most patients can be treated with a standard transnasal approach, the transorbital approach can be used as part of a multiportal strategy for those with difficult to access mucoceles. Future prospective studies are needed to further characterize patient selection and outcomes.

Comparison of Micro-Computed Tomography and Clinical Computed Tomography Protocols for Visualization of Nasal Cartilage Before Surgical Planning for Rhinoplasty.

IMPORTANCE: There is no imaging standard to model nasal cartilage for the planning of rhinoplasty procedures. Preoperative visualization of cartilage may improve objective evaluation of nasal deformities, surgical planning, and surgical reconstruction. OBJECTIVES: To evaluate the feasibility of visualizing nasal cartilage using high resolution micro-computed tomography (CT) compared with the criterion standard of pathologic findings in a cadaveric specimen and to evaluate its accuracy compared with various clinical CT protocols. DESIGN, SETTING, AND PARTICIPANTS: Anatomic study at the University of Washington using single human cadaveric nasal specimens performed from July 10, 2017, to March 30, 2018. INTERVENTIONS: A micro-CT acquisition with 60-micron resolution was obtained of a nasal specimen. The specimen was then scanned with 5 different clinical CT protocols to span both clinical care and machine limits. The specimen was then sectioned in 5-mm axial slices for pathologic analysis. MAIN OUTCOMES AND MEASURES: Micro-CT images were registered to pathologic specimen cross-sections using a graphite fiducial system. Cartilage substructures were manually segmented and analyzed. A library of matched images across the micro-CT and various clinical CT protocols was then developed. Region of interest analysis was performed for each of the cartilage structures and their boundaries on clinical CT protocols and micro-CT, with the outcome of mean (SD) density using Hounsfield units. RESULTS: A single human cadaveric nasal specimen was used to obtain the following results. Lower lateral cartilage, upper lateral cartilage, and septal cartilage were accurately delineated on the micro-CT images compared with pathologic findings. The mean absolute deviation from pathologic findings was 0.30 mm for septal cartilage thickness, 0.98 mm for maximal upper lateral cartilage length, and 1.40 mm for maximal lower lateral cartilage length. On clinical CT protocols, only septal cartilage was well discriminated from boundary. Higher radiation dose resulted in more accurate density measurements of cartilage, but it did not ultimately improve ability to discriminate cartilage. CONCLUSIONS AND RELEVANCE: The results of this anatomic study may represent a notable step toward advancing knowledge of the capabilities and pitfalls of nasal cartilage visualization on CT. Nasal cartilage visualization was feasible on the micro-CT compared with pathologic findings. Future research may further examine the barriers to accurately visualizing upper lateral cartilage and lower lateral cartilage, a prerequisite for clinical application. LEVEL OF EVIDENCE: NA.

Development of the international orbital Cavernous Hemangioma Exclusively Endonasal Resection (CHEER) staging system.

BACKGROUND: Orbital cavernous hemangiomas (OCH) are the most common adult orbital tumor and represent an ideal index lesion for endonasal orbital tumor surgery. In order to standardize outcomes reporting, an anatomic-based staging system was developed. METHODS: An international, multidisciplinary panel of 23 experts in orbital tumor surgery was formed. A modified Delphi method was used to develop the cavernous hemangioma exclusively endonasal resection (CHEER) staging system with a total of 2 rounds being completed. RESULTS: Tumors medial to a plane along the long axis of the optic nerve may be considered amenable for an exclusively endonasal resection. In select cases, tumors may extend inferolaterally if the tumor remains below a plane from the contralateral naris through the long axis of the optic nerve (ie, plane of resectability [POR]). This definition reached consensus with 91.3% of panelists in agreement. Five stages were designed based on increasing technical resection difficulty and potential for morbidity. Stages were based on the relationship of the tumor to the extraocular muscles, the inferomedial muscular trunk of the ophthalmic artery (IMT), and orbital foramina. Staging by anatomic location also reached consensus with 87.0% of panelists in agreement. Size was not included in the staging system due to the lack of agreement on the contribution of size to resection difficulty. CONCLUSION: Endoscopic orbital tumor surgery is a nascent field with a growing, yet heterogeneous, body of literature. The CHEER staging system is designed to facilitate international, high-quality, standardized studies establishing the safety, efficacy, and outcomes of endonasal resection of OCH.

Surgical anatomy of the face: implications for modern face-lift techniques.

OBJECTIVE: To delineate the anatomic architecture of the melolabial fold with surrounding structures and to elucidate potential implications for face-lift techniques. METHODS: A total of 100 facial halves (from 50 cadaveric heads) were studied, including gross and microscopic dissection and histologic findings. Laboratory findings were correlated with intraoperative findings in more than 150 deep-plane face-lift dissections (300 facial halves) performed during the study period. RESULTS: In contrast to previous reports, the superficial musculoaponeurotic system (SMAS) was not found to form an investing layer in the midface. The SMAS, zygomatici muscles, and levator labii superioris alaeque nasi were found to be located in corresponding anatomic layers and to form a functional unit. Additional findings of the present study include the description of 3 structurally different portions of the melolabial fold, of an anatomic space below the levator labii superioris alaeque nasi (sublevator space), and of extensions of the buccal fat pad into the sublevator space and the middle third of the melolabial fold. CONCLUSIONS: The findings of the present study may contribute to augment our understanding of the complex anatomy of the midface and melolabial fold. Potential implications for modern face-lift techniques are discussed.

Bilateral Transorbital and Transnasal Endoscopic Resection of a Frontal Sinus Osteoblastoma and Orbital Mucocele: A Case Report and Review of the Literature.

OBJECTIVE: Describe a novel treatment approach to a rare bony neoplasm in the frontal sinus. STUDY DESIGN: Case report. METHODS: Retrospective chart review of an osteoblastoma of the frontal sinuses complicated by a right orbital mucocle. Demographic, endoscopic, radiographic, pathologic, and surgical data were collected for synthesis and review. MEDLINE, Embase, and Cochrane databases were searched from 1977 to 2017 to review publications of surgical management of frontal sinus neoplasms. RESULTS: A single female patient with a large frontal sinus osteoblastoma was successfully treated with a bilateral transorbital and transnasal approach. The right orbital mucocele was marsupialized into the frontal sinus. Gross total resection of the tumor was achieved, with complete resolution of the presurgical morbidity. The surgery was tolerated well without iatrogenic injury or sequela. CONCLUSION: Frontal sinus osteoblastoma is a rare condition. Complete surgical excision is considered curative. Various endoscopic and open approaches have been described. Here we show the feasibility and efficacy of a multiportal strategy in the successful management of a large frontal sinus osteoblastoma complicated by a right orbital mucocele.

Orbital Fractures.

Anatomic, rather than volumetric, reconstruction leads to improved outcomes in orbital reconstruction. Endoscopic visualization improves lighting and magnification of the surgical site and allows the entire operative team to understand and participate in the procedure. Mirror-image overlay display with navigation-guided surgery allows in situ fine adjustment of the implant contours to match the contralateral uninjured orbit. Precise exophthalmometry is important before, during, and after surgery to provide optimal surgical results.