Transciliary Supraorbital Approach Research Articles

Exploring optimal microscopic keyhole access to the skull base: an anatomical evaluation of transciliary supraorbital and transpalpebral orbitofrontal craniotomy approaches

Purpose: The past two decades have witnessed the rise of keyhole microscopic minimally invasive surgeries, including the transciliary supraorbital approach (TCA) and transpalpebral approach (TPA), commonly known as the transorbital approach. This study aims to elucidate the nuances, specific indications, and advantages of each approach. Methods: A series of dissections were conducted on five formalin-fixed, alcohol-preserved cadaver heads. The TCA was performed on one side, and the TPA on the other. Virtual measurements of working angles for both approaches were recorded. Additionally, three clinical cases were presented to illustrate the practical application of the techniques. Results: For TCA, the craniotomy dimensions were 1.7 cm x 2.5 cm (Cranial-Caudal (CC) x Lateral-Lateral (LL)), while for TPA, they measured 2.1 cm x 2.9 cm (CC x LL). The measurements of anterior clinoid processes (ACP) were obtained and compared between approaches. In the TCA, the mean ipsilateral ACP measurement was 62 mm (Range: 61 –63 mm), and the mean contralateral ACP measurement was 71.2 mm (Range: 70 –72 mm). In TPA, these measurements were 47.8 mm (Range: 47 –49 mm) and 62.8 mm (Range: 62 –64 mm), respectively. TCA exhibited an average cranial-caudal angle of 14.9°, while TPA demonstrated an average of 8.3°. Conclusion: The anterior cranial fossa was better exposed by a TCA, which also featured shorter operative times, enhanced midline visualization, and a quicker learning curve. Conversely, the middle fossa was better exposed by a TPA, making it an excellent option for middle fossa pathologies, including those in the anterior temporal lobe. After sphenoid bone wing drilling, the TPA offers superior visualization from the lateral to the medial aspect and enhances the CC angle. Additionally, the TPA reduces the risk of postoperative frontalis palsy based on anatomic landmarks. However, the TPA requires a greater cranial osteotomy, and due to unfamiliarity with eyelid anatomy, the learning curve for most neurosurgeons is lengthier for this procedure.

HP43: Electrophysiological reactions to intraoperative irritation of the optic nerve: A clue for intraoperative optic nerve mapping?

Intraoperative control of optic nerve function preservation during neurosurgical operations currently relies mainly on monitoring of visual evoked potentials. Unfortunately, they detect peril only when the visual pathways are already compromised, sometimes irreversibly. In contrast, electrophysiological stimulation mapping of the nerves can be a fully preventive measure. However, direct sensory nerve mapping requires the patient to be awake during surgery, which is hardly feasible for surgeries targeting the optic nerve area. Another possible approach to sensory nerve mapping involves unconditioned electrophysiological responses evoked by sensory nerve stimulation. The necessary prerequisites for this approach are existence and stability of such responses for a particular sensory nerve in conditions of surgical anesthesia. Case report . A 52-year-old woman presented with meningioma in the area of right optic nerve and chiasm. She underwent microsurgical removal of the tumor through a transciliary supraorbital approach. Total intravenous anesthesia with propofol was used throughout the surgery. During the surgery, electrodes at the inferior margin of the right orbit repeatedly recorded electrophysiological reactions following touches, tractions and releases of tractions of the right optic nerve by the surgical instruments. Conclusions . The observed reactions suggest that either the unconditioned blink reflex or antidromic electroretinographic response to optic nerve irritation was conserved under the total intravenous anesthesia. This observation might be of value for development of intraoperative optic nerve mapping. This in turn could increase patients safety by identifying the optic nerve location without negative impacts on it. This report is accepted for publication in the Neurochirurgie journal: https://doi.org/10.1016/j.neuchi.2021.03.014.

Electrophysiological reactions to intraoperative irritation of the optic nerve. Case report and review of possible mechanisms

BackgroundIntraoperative control of optic nerve function conservation during neurosurgical operations currently relies mainly on visual evoked potential monitoring. Unfortunately, this detects peril only when the visual pathways are already compromised, sometimes irreversibly. In contrast, electrophysiological stimulation mapping of the nerves can be a fully preventive measure. However, direct sensory nerve mapping requires the patient to be awake during surgery, which is unfeasible for surgeries targeting the optic nerve area. Another possible approach to sensory nerve mapping involves unconditioned electrophysiological responses evoked by sensory nerve stimulation. The key point for this approach is the possibility of obtaining such responses for a particular sensory nerve under surgical anesthesia. Case reportA 52-year-old woman presented with meningioma in the area of right optic nerve and chiasm. She underwent microsurgical removal of the tumor through the transciliary supraorbital approach. During surgery, electrodes at the inferior margin of the right orbit repeatedly recorded electrophysiological reactions following contacts and displacements of the right optic nerve by the surgical instruments. ConclusionsThe observed reactions suggest that either the unconditioned blink reflex or antidromic electroretinographic response to optic nerve irritation was conserved under total intravenous anesthesia. This observation might be of value for development of intraoperative optic nerve mapping. This in turn could increase patient safety by identifying the exact optic nerve location before any negative impact on it.

REMOVAL OF SUPRASELLAR MENINGIOMAS VIA THE TRANSCILIARY SUPRAORBITAL APPROACH

The study objective is to compare the outcomes of surgeries performed via the transciliary supraorbital approach and traditional lateral supraorbital approach in patients with suprasellar meningiomas. Material and methods. The experimental group included 17 patients (8 males and 9 females aged between 38 and 67 years (mean age 48.7 ± 5.9 years)) with meningotheliomatous meningiomas (size between 15 and 46 mm (mean size 24.5 ± 5.7 mm) that underwent surgery via the transciliary supraorbital approach. All surgeries were performed by one surgeon. The control group included 20 patients (10 males and 10 females) that underwent surgery via the lateral supraorbital approach. These surgeries were also performed by one surgeon. The 2 groups were matched for size and location of meningiomas. We compared the extent of surgery, frequency of complications, severity of cosmetic defects, and other parameters between the groups. Preoperative examination, microsurgical removal of the tumor, anesthesia, and postoperative management were the same in both groups. Results. We observed no differences in the extent of surgery, frequency of complaints, complications, and neurological status between participants in the experimental and control groups. There were no deaths in either group. Patients that underwent surgery via the transciliary supraorbital approach had lower blood loss than those who underwent surgery via the lateral supraorbital approach (145 ± 18 mL vs 186 ± 24 mL). The duration of surgery was also lower in the experimental group than in the control group (145 ± 24 min vs 167 ± 32 min). Cosmetic outcomes were evaluated using the Cosmetic Visual Analogue Scale. Participants in the experimental group had higher score (>90) than controls (2 patients reported scores of 70 and 80). Possible negative effects of the transciliary supraorbital approach include the risk of scarring in the eyebrow area, skin numbness in the frontal area, paralysis of the frontalis muscle, and the need for more accurate preoperative markings using neuronavigation. Conclusion. In general, the therapeutic effect of surgeries via the transciliary supraorbital and lateral supraorbital approaches do not differ. However, the use of the transciliary supraorbital approach allowed smaller incisions (in both skin and dura mater) and smaller trepanation holes (and as a result minimal displacement of brain structures during surgery). It also ensured lower blood loss and duration of surgery and improved the cosmetic effect. The decision on the surgical approach should be based on tumor characteristics with the consideration of patient’s opinion.

Transciliary Supraorbital Approach (Eyebrow Approach) for Resection of Retrochiasmatic Craniopharyngiomas: An Alternative Approach, Case Series, and Literature Review

Craniopharyngiomas are known for an irregular growth pattern and extension into the retrochiasmatic space with adherence to adjacent structures. We describe the use of the transciliary supraorbital approach (eyebrow approach) for resection of craniopharyngiomas with retrochiasmatic extension. Our clinical database was reviewed to identify operative cases of craniopharyngiomas between July 1998 and January 2011. Only patients who had retrochiasmatic extension and underwent an eyebrow approach were included in this analysis. Endoscopy was used to aid surgical resection at the discretion of the surgeon. Six patients were identified (three from a retrospective review and three during the course of prospective follow-up evaluation). The group included three men and three women (mean age: 41.2 years; range: 28-57 years). All patients had visual and hormonal deficits at presentation. Complete resection was achieved in four patients. Endoscopic assistance was used in three patients. Opening of the frontal sinus occurred in two cases during surgery; an additional surgical procedure was required for repair of a cerebrospinal fluid leak in one of these cases. The duration of clinical follow-up ranged from 18 to 97 months. All patients had excellent cosmetic results, visual improvement to a serviceable level, and a Karnofsky performance scale score ≥ 80. The eyebrow approach is safe for resection of craniopharyngiomas with retrochiasmatic extension. This approach offers a reasonable surgical corridor for resection of the retrochiasmatic tumor component and can be enhanced using endoscopic assistance.

Review of "Quantitative Anatomic Study of the Transciliary Supraorbital Approach: Benefits of Additional Orbital Osteotomy?"

Review of "Quantitative Anatomic Study of the Transciliary Supraorbital Approach: Benefits of Additional Orbital Osteotomy?"

Transciliary Supraorbital Approach: Some Practical Considerations

Transciliary Supraorbital Approach: Some Practical Considerations

Quantitative Anatomic Study of the Transciliary Supraorbital Approach

The transciliary supraorbital approach (TCSO) provides an anterior view for visualizing sellar, parasellar, and suprasellar structures. Whether an orbital osteotomy adds to this exposure has not been quantified. We quantitatively evaluated the TCSO and benefits of an additional orbital osteotomy for exposing common sites of anterior circulation aneurysms. Under image guidance, TCSO and orbital osteotomy were performed on 10 sides of 5 cadaver heads to quantify exposures of 4 surgical targets: (1) the junction of the anterior cerebral and anterior communicating arteries (ACoA); (2) the internal carotid artery (ICA) at the level of the posterior communicating artery (PCoA); (3) the bifurcation of the ICA; and (4) the middle cerebral artery (MCA) bifurcation. Horizontal and vertical angles of attack and surgical freedom for instrument manipulation were measured before and after the orbital rim and roof were removed. An orbital osteotomy significantly increased surgical freedom to the ACoA (from 471.15 +/- 182.14 mm2 to 683.35 +/- 283.78 mm2, P = .021); PCoA (from 746.58 +/- 242.78 mm2 to 966.23 +/- 360.22 mm2, P = .007); ICA bifurcation (from 616.08 +/- 310.95 mm2 to 922.38 +/- 374.88 mm2, P = .002); and MCA bifurcation (from 1160.77 +/- 412.03 mm2 to 1597.71 +/- 733.18 mm2, P = .004). There were no significant differences in horizontal angles of attack. The vertical angles of attack were significantly greater after orbital osteotomy, principally with the ACoA and ICA bifurcation as targets. TCSO combined with orbital osteotomy improves exposure. Removing the orbital rim and roof increases the area for instrument use and improves the vertical angle of attack to common sites in the anterior circulation involving aneurysms.

Transciliary supraorbital keyhole approach in the management of aneurysms of anterior circulation: Operative nuances

With improvement in neuroimaging, instrumentation and operative microscope optics, and with better understanding of microneuroanatomy, it is now possible to approach intracranial aneurysms of anterior circulation through a small eyebrow incision. The objective of the study is to highlight the advantages and limitations of transciliary supraorbital keyhole craniotomy for clipping of these aneurysms. We present our experience with 55 intracranial aneurysms in the anterior circulation in 52 consecutive patients (23 females and 29 males, age range 22-70 years) operated between 2003 and 2009. All these aneurysms were clipped by a supraorbital transciliary incision and a craniotomy measuring 2.5 x 1.5 cm. One patient required bilateral keyhole craniotomies for bilateral aneurysms. Of the 52 patients, 37 patients were in Grade I/II, and the rest were in Grade III-IV. Clipping could be done in all the patients, and in twelve patients there was intraoperative rupture of the aneurysm. While there was a learning curve, no limitations were apparent, and none of the patients required revision of the procedure or wrapping. None of the patients had suboptimal clip application. Postoperative check angiogram showed obliteration of the aneurysm in all the patients. Patients with preoperative Grade I/II could be discharged from the hospital within seven days, and cosmetic result was excellent in all the patients. Four patients with preoperative Grade IV died in the postoperative period due to vasospasm. The transciliary supraorbital approach offers clipping of intracranial aneurysm in anterior circulation with low approach related morbidity as compared to standard approach.