Silicone oil insulation effects on flash electroretinogram and visual evoked potential in patients with retinal detachment / Efectos del aislamiento del aceite de silicona sobre el electrorretinograma flash y el potencial evocado visual en pacientes con desprendimiento de retina

Background: Silicone oil is used as endotamponade following vitreoretinal surgery to maintain the retina reattached when indicated. This study investigates the hypothesis that silicone oil causes insulation effects on the retina by affecting its response to light. Methods: Electrophysiological responses to a flash stimulus were recorded using full-field electroretinography (ERG) and visual evoked potentials (VEP). Recordings were performed in 9 patients who underwent surgery for retinal detachment, before (1–2 days) and after (2–3 weeks) silicone oil removal (SOR) in both the study and the control eye. Flash ERG and VEP recordings were performed according to the ISCEV standard protocol. Results: Statistically significant differences were found in the study eye in the amplitudes of the ERG responses and their corresponding ratios, i.e. the amplitude after SOR over the amplitude before SOR, in all conditions tested. No differences were observed in the control eye. The mean ratio of photopic ERG response was 3.4 ± 2.4 for the study and 1.0 ± 0.3 for the control eye (p<0.001). The mean ratio of ERG flicker response was 3.1 ± 2.4 and 1.0 ± 0.3, respectively (p = 0.003). Scotopic flash ERG ratio was 5.0 ± 4.4 for the study and 1.3 ± 0.6 for the control eye (p = 0.012). No differences were observed for the amplitude and latency of flash VEP response after SOR. Conclusions: Silicone oil causes a reduction in flash ERG responses; no effect was found on flash VEP responses. ERGs in eyes filled with silicone oil should not be considered representative of retinal functionality, in contrast to VEPs, which are not affected by silicone oil presence.(AU)

The trans-sylvian trans-petrosal "half & half" approach-a how I do it.

BACKGROUND: Petroclival meningiomas are one of the most challenging tumors to be operated in the realm of neurosurgery. Many approaches have been developed over the years. METHOD: The authors describe the Half & Half (H&H) approach whose main indication is petroclival meningiomas with suprasellar extension. The part of the tumor located above CN III and in the retrochiasmatic space is addressed through a trans-sylvian, while the petroclival portion is through an extradural anterior petrosectomy approach. The wide surgical corridor given by this approach allows extensive tumor resection while avoiding the risk associated with the manipulation of intracavernous neurovascular structures. CONCLUSION: The H&H approach is an effective strategy to maximize the safe resection of petroclival meningiomas.

Behaviour, barriers and facilitators of shared decision making in breast cancer surgical treatment: A qualitative systematic review using a 'Best Fit' framework approach.

BACKGROUND: Due to the diversity and high sensitivity of the treatment, there were difficulties and uncertainties in the breast cancer surgical decision-making process. We aimed to describe the patient's decision-making behaviour and shared decision-making (SDM)-related barriers and facilitators in breast cancer surgical treatment. METHODS: We searched eight databases for qualitative studies and mixed-method studies about breast cancer patients' surgical decision-making process from inception to March 2021. The quality of the studies was critically appraised by two researchers independently. We used a 'best fit framework approach' to analyze and synthesize the evidence. RESULTS: Twenty-eight qualitative studies and three mixed-method studies were included in this study. Four themes and 10 subthemes were extracted: (a) struggling with various considerations, (b) actual decision-making behaviours, (c) SDM not routinely implemented and (d) multiple facilitators and barriers to SDM. CONCLUSIONS: Patients had various considerations of breast surgery and SDM was not routinely implemented. There was a discrepancy between information exchange behaviours, value clarification, decision support utilization and SDM due to cognitive and behavioural biases. When individuals made surgical decisions, their behaviours were affected by individual-level and system-level factors. Therefore, healthcare providers and other stakeholders should constantly improve communication skills and collaboration, and emphasize the importance of decision support, so as to embed SDM into routine practice. PATIENT AND PUBLIC CONTRIBUTION: This systematic review was conducted as part of a wider research entitled: Breast cancer patients' actual participation roles in surgical decision making: a mixed method research. The results of this project helped us to better analyze and generalize patients' views.

Peripheral nerve stimulation (PNS): A valid and definitive therapeutical option for a case of anterior cutaneous nerve entrapment syndrome (ACNES).

Anterior cutaneous nerve entrapment syndrome (ACNES) is a cause of moderate to severe chronic pain, hyperesthesia/hypoesthesia, and altered perception of heat/cold in a specific region of the anterior abdominal wall, referable to the territory of innervation of one or more anterior branches of the intercostal nerves. None of the therapeutic options currently available has proved to be effective in the long term or decisive. In recent years, we have begun to treat purely sensory neuropathies, such as this, with the implantation of wireless peripheral nerve stimulators (PNS), achieving the safety of modular and personalized analgesia. We report the case of a 41-year-old man suffering from ACNES of the 8th intercostal nerve for two years. We first performed two consecutive ultrasound-guided diagnostic blocks of the anterior cutaneous branch of the 8th intercostal right nerve and then elected the patient for ultrasound-guided nerve decompression followed by neuromodulation and pulsed-radiofrequency (PRF). Taking into account full employment, young age, and the likelihood of having to repeat the treatment several times, we considered him for Peripheral Nerve Stimulation (PNS) implantation under ultrasound guidance, and we implanted the wireless lead at the anterior branch of the right 8th intercostal nerve, and programmed tonic stimulation 100 Hz PW 200 ms. The patient reported immediate pain relief and never took medication for this problem again, at two years follow-up. PNS has had an increasing role in the management of chronic neuropathic pain, especially in merely sensitive neuropathies like ACNES. We support future research on this theme.

Percutaneous pulsed radiofrequency ablation of articular nerves of the hip joint in patients with chronic hip pain refractory to conventional analgesics.

OBJECTIVES: Total Hip Arthroplasty (THA) may be a risky proposition in patients with comorbidities, and they may require systemic analgesics for chronic hip pain (CHP). Since traditional pain medications may not provide complete pain relief or carry prohibitive adverse effects, pulsed radiofrequency (PRF) treatment of the hip articular nerves (HAN) has been proposed for effective clinical outcomes. We determined the efficacy of PRF-HAN in improvement in CHP compared to baseline pain on conventional systemic analgesics. METHODS: Between August 2015 and December 2021, 31 adult patients with severe comorbid conditions and excruciating chronic hip pain were subjected to a PRF-HAN procedure following a diagnostic block. All 31 patients received PRF of the articular branches of the femoral and obturator nerves. Demographic parameters, numerical rating scale (NRS), Harris Hip Score (HHS), WOMAC scores, the change of these scores from baseline, and any adverse effects were recorded before treatment and on day 1, 1st week, 6 weeks, and 6 months after treatment. RESULTS: All the patients who underwent the PRF-HAN reported a significant improvement in NRS, HHS, and WOMAC scores compared to the baseline values on day 1, at the end of the 1st week, and the 6th week (p<0.001). No adverse events were documented in the study post-procedure until the end of 6 months. CONCLUSION: PRF-HAN is a strong alternative for chronic pain management and augments physical functioning and a return to daily activity in patients who would be deprived of arthroplasty considering associated comorbid conditions.

Botox in below knee amputation for the management of post-operative contracture: a systematic review.

During the 1970s, scientists first used botulinum toxin to treat strabismus. While testing on monkeys, they noticed that the toxin could also reduce wrinkles in the glabella area. This led to its widespread use in both medical and cosmetic fields. The objective of the study was to evaluate the potential use of Botox in managing post-operative contracture after below-knee amputation. We conducted a systematic review In Pubmed, Cochrane Library, Embase, and Google Scholar using the MESH terms Botox, botulinum toxin, post-operative contracture, amputation, and below knee amputation. Our goal was to evaluate the potential use of Botox to manage post-operative contracture in patients who have undergone below-knee amputation. Our findings show evidence in the literature that Botox can effectively manage stump hyperhidrosis, phantom pain, and jumping stump, but no clinical trial has been found that discusses the use of Botox for post-operative contracture. Botox has been used in different ways to manage spasticity. Further studies and clinical trials are needed to support the use of Botox to manage this complication.

Ureteral duplicity with a left ureterocele: a case report.

An intravesical ureterocele is a rare condition in which a terminal ureter terminates in a cystic dilation of the bladder. We present the case of a 42-year-old female who presented with irritative lower urinary tract symptoms and left lower back pain. Computed tomography (CT) urography revealed ureteral duplication with a ureterocele complicated by upper tract obstruction. Treatment involved endoscopic ureterocelotomy, which successfully relieved symptoms and resolved renal obstruction.

Prognostic Value of Complete Resection of the High-Frequency Oscillation Area in Intracranial EEG: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVES: High-frequency oscillations (HFOs; ripples 80-250 Hz; fast ripples [FRs] 250-500 Hz) recorded with intracranial electrodes generated excitement and debate about their potential to localize epileptogenic foci. We performed a systematic review and meta-analysis on the prognostic value of complete resection of the HFOs-area (crHFOs-area) for epilepsy surgical outcome in intracranial EEG (iEEG) accessing multiple subgroups. METHODS: We searched PubMed, Embase, and Web of Science for original research from inception to October 27, 2022. We defined favorable surgical outcome (FSO) as Engel class I, International League Against Epilepsy class 1, or seizure-free status. The prognostic value of crHFOs-area for FSO was assessed by (1) the pooled FSO proportion after crHFOs-area; (2) FSO for crHFOs-area vs without crHFOs-area; and (3) the predictive performance. We defined high combined prognostic value as FSO proportion >80% + FSO crHFOs-area >without crHFOs-area + area under the curve (AUC) >0.75 and examined this for the clinical subgroups (study design, age, diagnostic type, HFOs-identification method, HFOs-rate thresholding, and iEEG state). Temporal lobe epilepsy (TLE) was compared with extra-TLE through dichotomous variable analysis. Individual patient analysis was performed for sex, affected hemisphere, MRI findings, surgery location, and pathology. RESULTS: Of 1,387 studies screened, 31 studies (703 patients) met our eligibility criteria. Twenty-seven studies (602 patients) analyzed FRs and 20 studies (424 patients) ripples. Pooled FSO proportion after crHFOs-area was 81% (95% CI 76%-86%) for FRs and 82% (73%-89%) for ripples. Patients with crHFOs-area achieved more often FSO than those without crHFOs-area (FRs odds ratio [OR] 6.38, 4.03-10.09, p < 0.001; ripples 4.04, 2.32-7.04, p < 0.001). The pooled AUCs were 0.81 (0.77-0.84) for FRs and 0.76 (0.72-0.79) for ripples. Combined prognostic value was high in 10 subgroups: retrospective, children, long-term iEEG, threshold (FRs and ripples) and automated detection and interictal (FRs). FSO after complete resection of FRs-area (crFRs-area) was achieved less often in people with TLE than extra-TLE (OR 0.37, 0.15-0.89, p = 0.006). Individual patient analyses showed that crFRs-area was seen more in patients with FSO with than without MRI lesions (p = 0.02 after multiple correction). DISCUSSION: Complete resection of the brain area with HFOs is associated with good postsurgical outcome. Its prognostic value holds, especially for FRs, for various subgroups. The use of HFOs for extra-TLE patients requires further evidence.

A quantitative comparative surgical analysis of the endoscopic transorbital approach and frontotemporal-orbitozygomatic approach for extradural exposure of the cavernous sinus.

OBJECTIVE: Recently, the endoscopic superior eyelid transorbital approach (SETA) has emerged as a potential alternative to access the cavernous sinus (CS). Several previous studies have attempted to quantitatively compare the traditional open anterolateral skull base approaches with transorbital exposure; however, these comparisons have been limited to the area of exposure provided by the bone opening and trajectory, and fail to account for the main avenues of exposure provided by subsequent requisite surgical maneuvers. The authors quantitatively compare the surgical access provided by the frontotemporal-orbitozygomatic (FTOZ) approach and the SETA following applicable periclinoid surgical maneuvers, evaluate the surgical exposure of key structures in each, and discuss optimal approach selection. METHODS: SETA and FTOZ approaches were performed with subsequent applicable surgical maneuvers on 8 cadaveric heads. The lengths of exposure of cranial nerves (CNs) II-VI and the cavernous internal carotid artery; the areas of the space accessed within the supratrochlear, infratrochlear, and supramaxillary (anteromedial) triangles; the total area of exposure; and the angles of attack were measured and compared. RESULTS: Exposure of the extradural CS was comparable between approaches, whereas access was significantly greater in the FTOZ approach compared with the SETA. The lengths of extradural exposure of CN III, V1, V2, and V3 were comparable between approaches. The FTOZ approach provided marginally increased exposure of CNs IV (20.9 ± 2.36 mm vs 13.4 ± 3.97 mm, p = 0.023) and VI (14.1 ± 2.44 mm vs 9.22 ± 3.45 mm, p = 0.066). The FTOZ also provided significantly larger vertical (44.5° ± 6.15° vs 18.4° ± 1.65°, p = 0.002) and horizontal (41.5° ± 5.40° vs 15.3° ± 5.06°, p < 0.001) angles of attack, and thus significantly greater surgical freedom, and provided significantly greater access to the supratrochlear (p = 0.021) and infratrochlear (p = 0.007) triangles, and significantly greater exposure of the cavernous internal carotid artery (17.2 ± 1.70 mm vs 8.05 ± 2.37 mm, p = 0.001). Total area of exposure was also significantly larger in the FTOZ, which provided wide access to the lateral wall of the CS as well as the possibility for intradural access. CONCLUSIONS: This is the first study to quantitatively identify the relative advantages of the FTOZ and transorbital approaches at the target region following requisite surgical maneuvers. Understanding these data will aid in selecting an optimal approach and maneuver set based on target lesion size and location.

Endoscopic transorbital approach in children: surgical technique and early results.

OBJECTIVE: In this study, the authors aimed to describe the endoscopic transorbital approach (ETOA) in children. METHODS: Six pediatric patients (2 girls and 4 boys) underwent the ETOA for paramedian skull base lesions at a single institution between September 2016 and February 2023. RESULTS: The median age at the time of surgery was 7.5 (range 4-18) years. The median follow-up period was 33 (range 9-60) months. In this series, the ETOA level of difficulty included stage 1 (n = 2, 33.3%), stage 3 (n = 3, 50%), and stage 5 (n = 1, 16.7%). The ETOA was performed for tumor resection in 4 cases; the final pathology consisted of fibrous dysplasia, pilocytic astrocytoma, metastatic neuroblastoma, and choroid plexus papilloma. The procedure was also performed for repair of a petrous apex meningocele and for lateral orbital wall decompression of traumatic lateral rectus muscle entrapment. One patient experienced a transient cranial nerve III palsy after the procedure. There were no operative deaths in this series. CONCLUSIONS: In select cases, the ETOA can be considered a minimally invasive alternative for conventional skull base approaches in the armamentarium of pediatric skull base surgery. Further investigation and the accumulation of experience are warranted in the future to enhance the efficacy and applicability of the ETOA in pediatric patients.

Improved optic nerve visualization and treatment planning through a dedicated optic nerve MRI protocol.

OBJECTIVE: This study describes an innovative optic nerve MRI protocol for better delineating optic nerve anatomy from neighboring pathology. METHODS: Twenty-two patients undergoing MRI examination of the optic nerve with the dedicated protocol were identified and included for analysis of imaging, surgical strategy, and outcomes. T2-weighted and fat-suppressed T1-weighted gadolinium-enhanced images were acquired perpendicular and parallel to the long axis of the optic nerve to achieve en face and in-line views along the course of the nerve. RESULTS: Dedicated optic nerve MRI sequences provided enhanced visualization of the nerve, CSF within the nerve sheath, and local pathology. Optic nerve sequences leveraged the "CSF ring" within the optic nerve sheath to create contrast between pathology and normal tissue, highlighting areas of compression. Tumor was readily tracked along the longitudinal axis of the nerve by images obtained parallel to the nerve. The findings augmented treatment planning. CONCLUSIONS: The authors present a dedicated optic nerve MRI protocol that is simple to use and affords improved cross-sectional and longitudinal visualization of the nerve, surrounding CSF, and pathology. This improved visualization enhances radiological evaluation and treatment planning for optic nerve lesions.

Transpalpebral mini-orbitozygomatic approach for nonvascular skull base lesions: a single neurosurgeon's experience.

OBJECTIVE: The authors aim to describe the advantages, utility, and disadvantages of the transpalpebral mini-orbitozygomatic (MOZ) approach for tumors of the lateral and superior orbit, orbital apex, anterior clinoid, anterior cranial fossa, middle cranial fossa, and parasellar region. METHODS: The surgical approach from skin incision to closure is described while highlighting key technical and anatomical considerations, and cadaveric dissection demonstrates the surgical steps and focuses on important anatomy. Intraoperative images were included to supplement the cadaveric dissection. A retrospective review of adults who had undergone the MOZ approach for nonvascular pathology performed by a single neurosurgeon from 2017 to 2023 was included in this institutional review board-approved study. Descriptive statistics was used to summarize the data. Four representative cases were included to demonstrate the utility of the MOZ approach. RESULTS: The study included 65 patients (46 female, 19 male), average age 54.84 years, who had undergone transpalpebral MOZ surgery. Presenting symptoms included visual changes (53.8% of cases), vision loss (23.1%), diplopia (21.8%), and proptosis (13.8%). The optic nerve and optic chiasm were involved in 32.3% and 10.8% of cases, respectively. The most common pathology was meningioma (81.5% of cases), and gross-total resection was achieved in 50% of all cases. Major complications included an infection and a carotid injury. Improvement of preoperative symptoms was reported in 92.2% of cases. Visual acuity improved in 12 patients. The mean follow-up was 8.57 ± 8.45 months. CONCLUSIONS: The MOZ approach is safe and durable. The transpalpebral incision provides better cosmesis and functional outcomes than those of standard anterolateral approaches to the skull base. Careful consideration of the limits of the approach is paramount to appropriate application on a case-by-case basis. Further quantitative anatomical studies can help to define and compare the utility of the approach to open cranio-orbital and endoscopic transorbital approaches.

Clinical outcomes and complications of eyelid versus eyebrow approaches to supraorbital craniotomy: systematic review and indirect meta-analysis.

OBJECTIVE: Eyebrow supraorbital craniotomy is a versatile keyhole technique for treating intracranial pathologies. The eyelid supraorbital approach, an alternative approach to an eyebrow supraorbital craniotomy, has not been widely adopted among most neurosurgeons. The purpose of this systematic review and meta-analysis was to perform a pooled analysis of the complications of eyebrow or eyelid approaches for the treatment of aneurysms, meningiomas, and orbital tumors. METHODS: A systematic review of the literature in the PubMed, Embase, and Cochrane Review databases was conducted for identifying relevant literature using keywords such as "supraorbital," "eyelid," "eyebrow," "tumor," and "aneurysm." Eyebrow supraorbital craniotomies with or without orbitotomies and eyelid supraorbital craniotomies with orbitotomies for the treatment of orbital tumors, intracranial meningiomas, and aneurysms were selected. The primary outcomes were overall complications, cosmetic complications, and residual aneurysms and tumors. Secondary outcomes included five complication domains: orbital, wound-related, scalp or facial, neurological, and other complications. RESULTS: One hundred three articles were included in the synthesis. The pooled numbers of patients in the eyebrow and eyelid groups were 4689 and 358, respectively. No differences were found in overall complications or cosmetic complications between the eyebrow and eyelid groups. The proportion of residuals in the eyelid group (11.21%, effect size [ES] 0.26, 95% CI 0.12-0.41) was significantly higher (p < 0.05) than that in the eyebrow group (6.17%, ES 0.10, 95% CI 0.08-0.13). A subgroup analysis demonstrated significantly higher incidences of orbital, wound-related, and scalp or facial complications in the eyelid group (p < 0.05), but higher other complications in the eyebrow group. Performing an orbitotomy substantially increased the complication risk. CONCLUSIONS: This is the first meta-analysis that quantitatively compared complications of eyebrow versus eyelid approaches to supraorbital craniotomy. This study found similar overall complication rates but higher rates of selected complication domains in the eyelid group. The literature is limited by a high degree of variability in the reported outcomes.

Transorbital neuroendoscopic surgery for treatment of sphenoid wing meningiomas extending to the cavernous sinus: clinical implications and a technical illustration.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of transorbital neuroendoscopic surgery (TONES) in the management of sphenoid wing meningiomas (SWMs) with cavernous sinus and orbital invasion. METHODS: The authors conducted a retrospective review of 32 patients with SWMs treated at Gazi University using TONES from October 2019 to May 2023. The study includes clinical applications to elucidate the endoscopic transorbital approach. Surgical techniques focused on safe subtotal resection, aiming to minimize residual tumor volume for subsequent radiosurgery. Data were collected on patient demographics, tumor characteristics, surgical procedures, complications, and postoperative outcomes, including radiological imaging and ophthalmological evaluations. RESULTS: Surgical dissections delineated a three-phase endoscopic transorbital approach: extraorbital, intraorbital, and intracranial. In the clinical application, gross-total resection was not achieved in any patient because of planned postoperative Gamma Knife radiosurgery. The mean follow-up period was 16.3 months. Of 30 patients with preoperative proptosis, 25 experienced postoperative improvement. No new-onset extraocular muscle paresis or visual loss occurred postoperatively. The average hospital stay was 1.15 days, with minimal complications and no significant morbidity or mortality. CONCLUSIONS: Total resection of SWMs invading the cavernous sinus and orbit is associated with substantial risks, particularly cranial nerve deficits. TONES offers a minimally invasive alternative, reducing morbidity compared with transcranial approaches, and represents a significant advancement in the surgical management of SWMs, especially those extending into the cavernous sinus and orbit. The approach provides a safe, effective, and patient-centric approach, prioritizing subtotal resection to minimize neurological deficits while preparing patients for adjunctive radiosurgery. This study positions TONES as a transformative surgical technique, aligning therapeutic efficacy with neurovascular preservation and postoperative recovery.

Open-door extended endoscopic transorbital technique to the paramedian anterior and middle cranial fossae: technical notes, anatomomorphometric quantitative analysis, and illustrative case.

OBJECTIVE: The superior eyelid endoscopic transorbital approach (SETOA) provides a direct and short minimally invasive route to the anterior and middle skull base. Nevertheless, it uses a narrow corridor that limits its angles of attack. The aim of this study was to evaluate the feasibility and potential benefits of an "extended" conservative variant of the "standard" endoscopic transorbital approach-termed "open-door"-to enhance the exposure of lesions affecting the paramedian aspect of the anterior and middle cranial fossae. METHODS: First, the authors described the technical nuances of the open-door extended transorbital approach (ODETA). Next, they documented its morphometric advantages over standard SETOA. Finally, they provided a clinical-anatomical application to demonstrate enhanced exposure and better angles of attack to treat lesions occupying the paramedian anterior and middle cranial fossae. Five adult cadaveric specimens (10 sides) initially underwent standard SETOA and then extended open-door SETOA (ODETA to the paramedian anterior and middle fossae). The adjunct of hinge-orbitotomy, through three surgical steps and straddling the frontozygomatic suture, converted conventional SETOA to its extended open-door variant. CT scans were performed before dissection and uploaded to the neuronavigation system for quantitative analysis. The angles of attack on the axial plane that addressed four key landmarks, namely the tip of the anterior clinoid process (ACP), foramen rotundum (FR), foramen ovale (FO), and trigeminal impression (TI), were calculated for both operative techniques and compared. RESULTS: Hinge-orbitotomy of the extended open-door SETOA resulted in several surgical, functional, and esthetic advantages: it provided wider axial angles of attack for each of the target points, with a gain angle of 26.68° ± 1.31° for addressing the ACP (p < 0.001), 29.50° ± 2.46° for addressing the FR (p < 0.001), 19.86° ± 1.98° for addressing the FO (p < 0.001), and 17.44° ± 2.21° for addressing the lateral aspect of the TI (p < 0.001), while hiding the skin scar, avoiding temporalis muscle dissection, preserving flap vascularization, and decreasing the rate of bone infection and degree of orbital content retraction. CONCLUSIONS: The extended open-door technique may be specifically suited for selected patients affected by paramedian anterior and middle fossae lesions, with prevalent anteromedial extension toward the anterior clinoid, the foremost compartment of the cavernous sinus and FR and not completely controlled with the pure endoscopic transorbital approach.

Anterolateral keyhole transorbital routes to the skull base: a comparative anatomical study.

OBJECTIVE: Although keyhole transorbital approaches are gaining traction, their indications have not been adequately studied comparatively. In this study the authors have defined them also as transwing approaches-meaning that they use the different facies of the sphenoid wing for cranial entry-and sought to compare the four major ones: 1) lateral orbitocraniotomy through a lateral canthal incision (LatOrb); 2) modified orbitozygomatic approach through a palpebral incision (ModOzPalp); 3) modified orbitozygomatic approach through an eyebrow incision (ModOzEyB); and 4) supraorbital craniotomy through an eyebrow incision (SupraOrb), coupled with its expanded version (SupraTransOrb). METHODS: Cadaveric dissections were performed at the neuroanatomy lab. To delineate the skull base exposure, four formalin-fixed heads were used, with two sides dedicated to each approach. The outer limits were assessed via image guidance and were mapped and illustrated accordingly. A fifth head was dissected purely endoscopically, just to facilitate an overview of the transwing concept. Qualitative features were also rigorously examined. RESULTS: The LatOrb proves to be more versatile in the middle cranial fossa (MCF), whereas the anterior cranial fossa (ACF) exposure is limited to a small area above the sphenoid ridge. An anterior clinoidectomy is possible; however, the exposure of the roof of the optic canal is suboptimal. The ModOzPalp adequately exposes both the ACF and MCF. Its lateral trajectory allows the inferior to superior view, yet there is restricted access to the medial anterior skull base (olfactory groove). The ModOzEyB also provides extensive exposure of the ACF and MCF, but has a more superior to inferior trajectory compared to the ModOzPalp, making it more appropriate for pathology reaching the medial anterior skull base or even the contralateral side. The anterior clinoidectomy is performed with improved visualization of the optic canal. The SupraOrb provides mainly anterior cranial base exposure, with minimal middle fossa. An anterior clinoidectomy can be performed, but without any direct observation of the superior orbital fissure. Some MCF access can be accomplished if the lateral sphenoid wing is drilled inferiorly, leading to its highly versatile variant, the SupraTransOrb. CONCLUSIONS: All the aforementioned approaches use the sphenoid wing as skull base corridor from a specific orientation point; hence these are designated as transwing approaches. Their peculiarities mandate careful case selection for the effective and safe completion of the surgical goals.

360° around the orbit: key surgical anatomy of the microsurgical and endoscopic cranio-orbital and orbitocranial approaches.

OBJECTIVE: Several pathologies either invade or arise within the orbit. These include meningiomas, schwannomas, and cavernous hemangiomas among others. Although several studies describing various approaches to the orbit are available, no study describes all cranio-orbital and orbitocranial approaches with clear, surgically oriented anatomical descriptions. As such, this study aimed to provide a comprehensive guide to the microsurgical and endoscopic approaches to and through the orbit. METHODS: Six formalin-fixed, latex-injected cadaveric head specimens were dissected in the surgical anatomy laboratory at the authors' institution. In each specimen, the following approaches were modularly performed: endoscopic transorbital approaches (ETOAs), including a lateral transorbital approach and a superior eyelid crease approach; endoscopic endonasal approaches (EEAs), including those to the medial orbit and optic canal; and transcranial approaches, including a supraorbital approach, a fronto-orbital approach, and a 3-piece orbito-zygomatic approach. Each pertinent step was 3D photograph-documented with macroscopic and endoscopic techniques as previously described. RESULTS: Endoscopic endonasal approaches to the orbit afforded excellent access to the medial orbit and medial optic canal. Regarding ETOAs, the lateral transorbital approach afforded excellent access to the floor of the middle fossa and, once the lateral orbital rim was removed, the cavernous sinus could be dissected and the petrous apex drilled. The superior eyelid approach provides excellent access to the anterior cranial fossa just superior to the orbit, as well as the dura of the lesser wing of the sphenoid. Craniotomy-based approaches provided excellent access to the anterior and middle cranial fossa and the cavernous sinus, except the supraorbital approach had limited access to the middle fossa. CONCLUSIONS: This study outlines the essential surgical steps for major cranio-orbital and orbitocranial approaches. Endoscopic endonasal approaches offer direct medial access, potentially providing bilateral exposure to optic canals. ETOAs serve as both orbital access and as a corridor to surrounding regions. Cranio-orbital approaches follow a lateral-to-medial, superior-to-inferior trajectory, progressively allowing removal of protective bony structures for proportional orbit access.

Endoscopic precaruncular medial transorbital and endonasal multiport approaches to the contralateral skull base: a clinicoanatomical study.

OBJECTIVE: Minimally invasive endoscopic endonasal multiport approaches create additional visualization angles to treat skull base pathologies. The sublabial contralateral transmaxillary (CTM) approach and superior eyelid lateral transorbital approach, frequently used nowadays, have been referred to as the "third port" when used alongside the endoscopic endonasal approach (EEA). The endoscopic precaruncular contralateral medial transorbital (cMTO) corridor, on the other hand, is an underrecognized but unique port that has been used to repair CSF rhinorrhea originating from the lateral sphenoid sinus recess. However, no anatomical feasibility studies or clinical experience exists to assess its benefits and demonstrate its potential role in multiport endoscopic access to the other contralateral skull base areas. In this study, the authors explored the application and potential utility of multiport EEA combined with the endoscopic cMTO approach (EEA/cMTO) to three target areas of the contralateral skull base: lateral recess of sphenoid sinus (LRSS), petrous apex (PA) and petroclival region, and retrocarotid clinoidocavernous space (CCS). METHODS: Ten cadaveric specimens (20 sides) were dissected bilaterally under stereotactic navigation guidance to access contralateral LRSS via EEA/cMTO. The PA and petroclival region and retrocarotid CCS were exposed via EEA alone, EEA/cMTO, and EEA combined with the sublabial CTM approach (EEA/CTM). Qualitative and quantitative assessments, including working distance and visualization angle to the PA, were recorded. Clinical application of EEA/cMTO is demonstrated in a lateral sphenoid sinus CSF leak repair. RESULTS: During the qualitative assessment, multiport EEA/cMTO provides superior visualization from a high vantage point and better instrument maneuverability than multiport EEA/CTM for the PA and retrocarotid CCS, while maintaining a similar lateral trajectory. The cMTO approach has significantly shorter working distances to all three target areas compared with the CTM approach and EEA. The mean distances to the LRSS, PA, and retrocarotid CCS were 50.69 ± 4.28 mm (p < 0.05), 67.11 ± 5.05 mm (p < 0.001), and 50.32 ± 3.6 mm (p < 0.001), respectively. The mean visualization angles to the PA obtained by multiport EEA/cMTO and EEA/CTM were 28.4° ± 3.27° and 24.42° ± 5.02° (p < 0.005), respectively. CONCLUSIONS: Multiport EEA/cMTO to the contralateral LRSS offers the advantage of preserving the pterygopalatine fossa contents and the vidian nerve, which are frequently sacrificed during a transpterygoid approach. This approach also offers superior visualization and better instrument maneuverability compared with EEA/CTM for targeting the petroclival region and retrocarotid CCS.

Endoscopic transorbital approach bone pillars: a comprehensive stepwise anatomical appraisal.

OBJECTIVE: The endoscopic superior eyelid transorbital approach has garnered significant consideration and gained popularity in recent years. Detailed anatomical knowledge along with clinical experience has allowed refinement of the technique as well as expansion of its indications. Using bone as a consistent reference, the authors identified five main bone pillars that offer access to the different intracranial targeted areas for different pathologies of the skull base, with the aim of enhancing the understanding of the intracranial areas accessible through this corridor. METHODS: The authors present a bone-oriented review of the anatomy of the transorbital approach in which they conducted a 3D analysis using Brainlab software and performed dry skull and subsequent cadaveric dissections. RESULTS: Five bone pillars of the transorbital approach were identified: the lesser sphenoid wing, the sagittal crest (medial aspect of the greater sphenoid wing), the anterior clinoid, the middle cranial fossa, and the petrous apex. The associations of these bone targets with their respective intracranial areas are reported in detail. CONCLUSIONS: Identification of consistent bone references after the skin incision has been made and the working space is determined allows a comprehensive understanding of the anatomy of the approach in order to safely and effectively perform transorbital endoscopic surgery in the skull base.