Pretemporal Transcavernous Approach Research Articles

The Eyelid Trans-orbital Trans-cavernous Approach to the Basilar Apex: A Cadaveric Proof-of-Concept Study

Abstract Objective The pretemporal transcavernous approach is an elegant technique that provides exposure to the basilar apex, which is conventionally completed with a frontotemporal incision. This can also be performed via a minimally invasive eyelid transorbital approach, which has unique attributes. This is a proof-of-concept cadaveric study to demonstrate details of the combination of these two approaches. Design This study is a proof-of-concept study using cadaveric heads. Setting This study is a proof-of-concept study in a cadaveric laboratory. Participants A latex-injected cadaveric head. Main Outcome Measures Detailed dissection was performed and demonstrated in a step-by-step fashion. Results The eyelid transorbital approach provides the exact exposure required to complete the pretemporal osteotomy including an anterior clinoidectomy and dissection, so that a transcavernous approach can be completed. The basilar apex and its branches can also be accessed via the eyelid transorbital approach, with comparable exposure to the traditional approach; however, the access trajectory is much narrower. It takes advantages of the inferior corridor with a more medial access angle and provides a complementary perspective to the cavernous sinus contents and basilar apex complex. Conclusion The combination of an eyelid transorbital and pretemporal transcavernous approaches can achieve a deep exposure via a minimally invasive incision, which may add an additional approach to the cavernous sinus and basilar apex regions.

The learning curve for cavernous sinus surgery illustrated by symptomatic intracavernous aneurysm clipping through a pretemporal transcavernous approach.

The anatomy of the cavernous sinus (CS) has been well studied in the laboratory for decades; however, performing surgery in and around the CS is still a challenge. To reveal the learning curve for CS surgery via the pretemporal transcavernous approach (PTTC), surgical procedures were examined. The authors proposed 4 levels of surgical difficulty in opening the walls of the CS through this approach. Details of the approach were illustrated by surgical videos of symptomatic intracavernous aneurysm clipping. Four levels of surgical difficulty were proposed. The higher the level, the more the CS walls were opened. Pathologies corresponding to each level of difficulty in and around the CS were categorized in each level together with explanations. From 2015 to 2021, 5 patients with symptomatic intracavernous aneurysms (diplopia due to compressive cranial neuropathy) underwent the PTTC at the authors' institute and served as representative cases in opening the walls of the CS. All CS cases from 2009 to 2021 were reviewed and categorized to demonstrate the learning curve. Four levels of surgical difficulty are as follows: level 1, a basic Dolenc extradural approach, which involves opening the anterior third of the superior and lateral walls of the CS; level 2, mobilizing the internal carotid artery (ICA) and opening the proximal dural ring to enter the roof of the CS and treat lesions around the clinoid and upper cavernous ICA; level 3, opening the entire aspect of the superior and lateral walls of the CS, which involves opening the oculomotor triangle and peeling the lateral wall of the CS to the tentorial incisura; and level 4, mobilizing cranial nerves III, IV, and V1 to gain access to the supra-/infratrochlear triangles to have proximal ICA control and opening the posterior wall as the last step to enter the posterior fossa. Surgical steps were described and illustrated with surgical videos of symptomatic intracavernous aneurysm clipping. The learning curve for CS surgery is long. The authors use 4 levels of surgical difficulty to describe applications of the PTTC in CS surgery. This approach serves as an effective workhorse in treating CS pathologies with low morbidity and high success rates when performed by experienced neurosurgeons.

Pretemporal Transcavernous Approach for Resection of Non-meningeal Tumors of the Cavernous Sinus: Single Center Experience.

ObjectivesTo study the outcomes of the pretemporal transcavernous approach in the treatment of non-meningeal tumors involving cavernous sinus and to investigate the surgical strategy for these lesions.MethodsWe conducted a retrospective study of 45 patients with non-meningeal tumors involving cavernous sinus. All 45 patients received microsurgical resection via the pretemporal transcavernous approach from April 2012 to January 2019 by the same neurosurgeon. We analyzed clinical manifestations, image data, perioperative complications, surgical outcomes, functional outcomes, and follow-up data of these patients.ResultsGross total resection was achieved in 38 cases (84.4%) of the 45 patients. Preoperatively, a total of 64 individual cranial nerves were affected. Postoperatively, 92.2% of 64 impaired cranial nerves completely or partially restored function, 7.8% had worsened function compared with their preoperative statuses, and 5 new cranial nerve deficits (CNV) were observed in five patients during the last follow-up. Seven patients presented transient new cranial nerve deficits (5 CNIII and 2 CNVI), three cases suffered transient worsen cranial nerve deficits (3 CNIII and 1 CNVII). There were no cases of intracranial hematoma, intracranial infection, cerebrospinal fluid leaks, and death. The progression of residual tumor was observed in two patients (1 chordoma and 1 pituitary adenoma).ConclusionsNon-meningeal tumors involving cavernous sinus can be safely and radically removed with less morbidity and mortality. Pretemporal transcavernous approach is an ideal approach to the cavernous sinus and can be tailored individually.

Recurrent meningiomas within and around the cavernous sinus after radiosurgery: the pretemporal transcavernous approach

Recurrent meningiomas within and around the cavernous sinus after radiosurgery: the pretemporal transcavernous approach

Recurrent Sphenocavernous Meningioma.

A case of a recurrent sphenocavernous meningioma is presented. The patient is a 42-year-old male who presented with an episode of transient right-sided numbness. A magnetic resonance imaging (MRI) revealed a large left sphenocavernous meningioma. The patient underwent a frontotemporal craniotomy for tumor resection. Near total resection was achieved with minimal residual in the left cavernous sinus (CS) and orbital apex. The pathology was consistent with meningioma, World Health Organization (WHO) grade I. A follow-up MRI was done 9 months after surgery and showed a growth of the residual tumor, which was treated with intensity modulated radiotherapy. Tumor growth was detected on serial imaging over a 4-year period. Surgical resection was offered. A left frontotemporal craniotomy with pretemporal transcavernous approach was performed. The bone flap was reopened and the dura was opened in a Y-shaped fashion. The roof of the optic canal was drilled off, and the falciform ligament was opened to decompress the optic nerve. The tumor was disconnected from the anterior clinoid region (the anterior clinoid process was eroded by the tumor) and reflected off the wall of the lateral CS. Tumor was adherent to the V2 fascicles (the lateral CS wall was resected in the first surgery) and was sharply dissected off. Gross total resection was achieved. The pathology was consistent with meningioma, WHO grade I. The patient had an unremarkable postoperative course without any new neurological deficits. The link to the video can be found at: https://youtu.be/KVBVw_86JqM .

Pretemporal Transcavernous Approach for Resection of an Orbito-Cavernous Oculomotor Schwannoma.

The following operative video demonstrates surgical tenets and nuances of the pretemporal transcavernous approach in an unusual case of a 33-year-old patient suffering new onset diplopia and a third nerve palsy due to an orbito-cavernous oculomotor schwannoma. Near total resection was accomplished through an extended pterional craniotomy with pretemporal transcavernous exposure of her lesion, resulting in resolution of her preoperative oculomotor palsy and visual dysfunction. When combined with extended pterional and modified frontotemporal orbitozygomatic approaches, the pretemporal transcavernous approach provides excellent surgical access to the parasellar region including the superior orbital fissure and cavernous sinus. Meticulous dissection and early identification of tissue planes, including cranial nerve and vascular anatomy, allows for safe removal of tumors arising in this region. The link to the video can be found at: https://youtu.be/EuIRTP7wWBQ .

Tailoring the surgical corridor to the basilar apex in the pretemporal transcavernous approach: morphometric analyses of different neurovascular mobilization maneuvers.

The pretemporal transcavernous approach (PTA) provides optimal exposure and access to the basilar artery (BA); however, the PTA can be invasive when vital neurovascular structures are mobilized. The goal of this study was to evaluate mobilization strategies to tailor approaches to the BA. After an orbitozygomatic craniotomy, 10 sides of 5 cadaveric heads were used to assess the surgical access to the BA via the opticocarotid triangle (OCT), carotid-oculomotor triangle (COT), and oculomotor-tentorial triangle (OTT). Measurements were obtained, and morphometric analyses were performed for natural neurovascular positions and after each stepwise expansion maneuver. An imaginary line connecting the midpoints of the limbus sphenoidale and dorsum sellae was used as a reference to normalize the measurements of BA exposure and to facilitate the clinical applicability of this technique. In the OCT, the exposed BA segment ranged from - 1 ± 3.9 to + 6 ± 2.0mm in length in its natural position. In the COT, the accessible BA segment ranged from - 4 ± 2.3 to - 2 ± 3.0mm in length in its natural position. Via the OTT, the accessible BA segment ranged from - 7 ± 2.6 to - 5 ± 2.8mm in length in its natural position. In the OCT, COT, and OTT, a posterior clinoidectomy extended the exposure down to - 6 ± 2.7, - 8 ± 2.5, and - 9± 2.9mm, respectively. This study quantitatively evaluated the need for the expansion maneuvers in the PTA to reach BA aneurysms according to the patient's anatomical characteristics.

Tailoring the surgical corridor to the basilar apex in the pretemporal transcavernous approach: morphometric analyses of different neurovascular mobilization maneuvers.

Tailoring the surgical corridor to the basilar apex in the pretemporal transcavernous approach: morphometric analyses of different neurovascular mobilization maneuvers.

The pretemporal trans-cavernous trans-Meckel's trans-tentorial trans-petrosal approach: a combo skill in treating skull base meningiomas.

Surgical treatments for skull base meningiomas are challenging. We found that most of these lesions (75%), despite locating at the anterior, middle or posterior fossa, could be dealt with a combo skill-the pretemporal trans-cavernous trans-Meckel's trans-tentorial trans-petrosal approach (PCMTP), which adopted the same curvilinear skin incision as for the classic pterional approach. Our aim of this study is to validate the application of this technique in treating skull base meningiomas. Patients underwent surgical intervention at our institute during 2010-2018 were retrospectively reviewed. We statistically analyzed the clinical, radiological, and pathological outcomes. In total, 109 patients operated with at least part of the PCMTP combo technique were included. The median follow-up time was 26.6months. Tumor locations were categorized into: Zone I-sphenoid ridge, olfactory groove, and juxtasellar meningiomas which could be dealt with pterional approach. Zone II-clinoidal and cavernous sinus meningiomas which could be dealt with pretemporal trans-cavernous approach. Zone III-Meckel's and Incisura meningiomas which could be dealt with trans-Meckel's trans tentorial approach. Zone IV-petroclival menigiomas which could be dealt with trans-petrosal approach. When an extensive tumor occupied the anterior, middle, and posterior fossa, the whole combination of the PCMTP technique was applied. The mortality rate is 3.7% (4 patients). Three patients (2.8%) suffered from postoperative deterioration and required occasional assistance. The location of tumor was associated with different Simpson grade removal (p = 0.0015) and resection rate (p < 0.001). The PCMTP is effective in treating skull base meningiomas.

The side door and front door to the upper retroclival region: a comparative analysis of the open pretemporal and the endoscopic endonasal transcavernous approaches.

The pretemporal transcavernous approach (PTA) and the endoscopic endonasal transcavernous approach (EETA) are both used to access the retroclival region. A direct quantitative comparison of both approaches has not been made. The authors compared the technical nuances of, and surgical exposure afforded by, each approach and identified the key elements of the approach selection process. Fourteen cadaveric specimens underwent either PTA (group A) or EETA with unilateral (group B) followed by bilateral (group C) interdural pituitary gland transposition. The percentage of drilled clivus; length of exposed oculomotor nerve (cranial nerve [CN] III), posterior cerebral artery (PCA), and superior cerebellar artery (SCA); and surgical area of exposure of both cerebral peduncles and the pons for the 3 groups were measured and compared. Group A had a significantly lower percentage of drilled area than group B (mean [SD], 35.6% [11.2%] vs 91.3% [4.9%], p < 0.01). In group C, 100% of the upper third of the clivus was drilled in all specimens. Significantly longer segments of the ipsilateral PCA (p < 0.01) and SCA (p < 0.01) were exposed in group A than in group B. There was no significant difference in the length of the ipsilateral CN III exposed among the 3 groups. There was also no significant difference between group A and either group B or group C for the contralateral CN III or PCA exposure. However, longer segments of the contralateral SCA were exposed in group C than in group A (p = 0.02). Furthermore, longer segments of CN III (p < 0.01), PCA (p < 0.01), and SCA (p < 0.01) were exposed in group C than in group B. For brainstem exposure, there was greater exposure of the pons in group C than in group A (mean [SD], 211.4 [19.5] mm2 vs 157.7 [25.3] mm2, p < 0.01) and group B (211.4 [19.5] mm2 vs 153.9 [34.1] mm2, p < 0.01). However, significantly greater exposure of the ipsilateral peduncle was observed in group A (mean [SD], 125.6 [43.1] mm2) than in groups B and C (56.3 [6.0] mm2, p < 0.01). Group C had significantly greater exposure of the contralateral peduncle than group B (p = 0.02). This study is the first to quantitatively identify the advantages and limitations of the PTA and EETA from an anatomical perspective. Understanding these data may help the skull base surgeon design a maximally effective yet minimally invasive approach to individual lesions.

Pretemporal transcavernous approach tailored surgery of cavernous sinus tumors: a consecutive series of 31 cases report

To investigate the indications of the pretemporal transcavernous approach for cavernous sinus tumors resection and design individually tailored surgery according to the extent of tumors and operation requirements. A retrospective analysis of clinical data, surgical outcomes and complications in a series of 31 cases with cavernous sinus tumor operated via the individually tailored pretemporal transcavernous approach between May 2012 and September 2015 in Department of Neurosurgery, Xiangya Hospital, Central South University. There were 13 male and 18 female patients, aging from 17 to 67 years with a mean of (41±14) years. The patients included 18 cases of shwannomas, 4 cases of meningiomas, 3 cases of cavernous hemangiomas, 2 cases of invasive pituitary adenomas, 1 case of chordoma, 1 case of chondroma, 1 case of recurrent teratoma, 1 case of metastatic nasopharyngeal carcinoma. The first followed-up visit was on the 3(rd) month after surgery, and if tumor progression or recurrence was observed on MRI, the Gamma knife treatment was recommended, the patient was followed up every 6 months, otherwise the patient was followed up again 6 months later, then, every 12 months. Gross total removal of tumors was achieved in 22 cases of 31 patients (71.0%), containing 17 cases of shwannomas, 3 cases of hemangiomas, 1 case of chondroma, 1 case of teratoma; subtotal removal in 6 cases (19.3%), including 3 cases of meningiomas, 1 case of pituitary adenoma, 1 case of chordoma, 1 case of metastatic carcinoma; partial removal in 3 cases (9.7%), comprising 1 case of meningioma, 1 case of recurrent shwannoma, 1 case of recurrent pituitary adenoma. The symptoms of cranial never aggravated in 5 cases, the new postoperative cranial never palsy was observed in 7 cases. There was no surgical mortality, intracranial hematoma, intracranial infection and cerebrospinal fluid leakage cases, ect. Twenty-eight cases were followed up for more than 3 months (3 to 40 months), 1 case of chordoma had tumor progression; the nerve function was restored in 5 cases, among the 12 cases with postoperatively new occurred or deteriorated cranial nerve paralysis. The pretemporal transcavernous approach can be used to resect tumors limited in cavernous sinus or tumors simultaneously involving the cavernous sinus and its vicinity areas, it can be individually tailored based on the extent and exposure of the tumor. This approach can improve the surgical results in terms of high tumor resection rate, less complication, is an ideal approach for cavernous sinus tumor resection.

Mobilization of the Transcavernous Oculomotor Nerve During Basilar Aneurysm Surgery

The transcavernous approach adds a significant exposure advantage in basilar aneurysm surgery. However, one of its frequently reported side effects is postoperative oculomotor nerve palsy. To present the technique of mobilizing the oculomotor nerve throughout its intracranial course and to analyze its consequences on the nerve tension and clinical outcome. The oculomotor nerve is mobilized from its mesencephalic origin to the superior orbital fissure. Its degree of mobility, related to the imposed pulling force, was measured in 11 cadaveric nerves. Tension was mathematically deduced and compared before and after mobilizing of the cavernous segment. One hundred four patients treated for basilar aneurysms with the orbitozygomatic pretemporal transcavernous approach were followed up for a 1-year period and evaluated for postoperative oculomotor nerve palsy. Releasing the transcavernous segment compared to cisternal mobilization alone resulted in a significant increase in freedom of mobility from 4 to 7.9 mm (P < .001) and in a significant decrease in tension from 0.8 to 0.5 N (P = .006). Ninety-nine percent of aneurysms treated with this technique were amenable to neck clipping, and a total of 84% of patients had a good postoperative outcome (modified Rankin Scale score, 0-2). All patients showed direct postoperative palsy; however, 97% had a complete recovery by 9 months. Only 3 patients had a persistent diplopia on medial gaze, which was corrected with prism glasses. Mobilization of the transcavernous oculomotor nerve results in better maneuverability and less tension on the nerve, which lead to successful surgical treatment and favorable oculomotor outcome.

Pretemporal Transcavernous Approach for Microsurgical Clipping of Giant, Embolized, and Lower Basilar Tip Aneurysms

Pretemporal Transcavernous Approach for Microsurgical Clipping of Giant, Embolized, and Lower Basilar Tip Aneurysms

Nuances and technique of the pretemporal transcavernous approach to treat low-lying basilar artery aneurysms

Basilar artery bifurcation aneurysms (BAAs) constitute a major surgical challenge, due to the depth of the target anatomy and narrowness of field, the close relationship with thalamoperforating arteries, and difficulty in obtaining proximal control. Moreover, to treat these aneurysms may be especially technically demanding when situated in a low-lying basilar apex configuration. The most used approaches to treat BAA are the subtemporal approach and the pterional approach. The advantages and disadvantages of these techniques are very well known. Variations of these approaches were created attempting to overcome the limitations imposed by the limited deep operative area. They have not been able to improve the working space in the depths of the interpeduncular and prepontine cisterns. The transcavernous approach was devised as a means of enlarging the area of exposure around the interpeduncular and prepontine cisterns. It involves the removal of the anterior clinoid process, cutting distal and proximal dural rings, opening the cavernous sinus, and drilling varied extension of dorsum sellae and clivus. The senior author (EdO) has used a pretemporal approach to deal with BAAs. The authors have added a transcavernous approach in a pretemporal perspective to treat low-lying, complex, or giant basilar artery aneurysms. In this paper, the authors detail its anatomical principles and technical nuances and present the clinical experience with using this technique.

Long-Term Outcome of Microsurgical Treatment of Symptomatic Cavernous Sinus Meningiomas

Objective: Most cavernous sinus meningiomas (CSMs) not only cause severe cranial nerve (CN) neuropathy, but also carry the high risk of occluding the internal carotid artery. The treatments for CSM are difficult and still controversial. We report our experience with the pretemporal transcavernous approach for resection of CSMs.

THE PERFORATOR-FREE ZONE OF THE POSTERIOR COMMUNICATING ARTERY AND ITS RELEVANCE IN APPROACHES TO THE INTERPEDUNCULAR CISTERN, ESPECIALLY THE TRANSCAVERNOUS APPROACH

Because the microsurgical working space in the interpeduncular fossa is very narrow, using different surgical approaches such as the pterional approach and/or the pretemporal transcavernous approach in combination with a division of the posterior communicating artery (PComm) at the longest perforator-free zone (PFZ) can help to enlarge the microscopic field of view and the working space in this area of the brain. In this microanatomic study, the variability of several parameters of the PComm, especially the location of the longest PFZ of the PComm, was examined and described in 23 cadaveric heads. In most cases, the mean length of the longest PFZ was found to be between 2 and 6 mm. In 80% of the cases, the longest PFZ was located closer to the posterior cerebral artery than to the internal carotid artery. A total of 82.5% of all the PComms measured were of the adult type. In 55% of all arteries, a premamillary artery was identified. When a short and adult-type PComm obscures the microscopic view of the operative field, dividing the PComm is mandatory. In other situations, dividing the PComm is facultative. Because the PComm is usually predominantly irrigated by the internal carotid artery, it is of hemodynamic advantage that the longest PFZ is typically located closest to the posterior cerebral artery. On the basis of this descriptive anatomic study, we conclude that when it is needed, division of an adult-type PComm at the longest PFZ is usually feasible and results in a low risk of compromising the blood flow to the branching perforators of the PComm.

The Pretemporal Transcavernous Approach to the Interpeduncular and Prepontine Cisterns: Microsurgical Anatomy and Technique Application

The Pretemporal Transcavernous Approach to the Interpeduncular and Prepontine Cisterns: Microsurgical Anatomy and Technique Application

The pretemporal transcavernous approach to the interpeduncular and prepontine cisterns: microsurgical anatomy and technique application.

To illustrate in a stepwise fashion the microsurgical anatomy of the transcavernous approach to the interpeduncular and prepontine cisterns and to discuss our initial results with 15 basilar tip aneurysms managed through that approach. Using 10 embalmed cadaveric heads perfused with colored silicon, we performed bilateral stepwise dissections of the transcavernous approach via an orbitozygomatic pretemporal craniotomy. Measurements of the exposure of the basilar artery obtained along the dorsum sellae and upper clivus were taken. Our clinical data were derived from a series of 15 patients with large basilar tip aneurysms treated surgically via the transcavernous approach between 1997 and 1999. Indications for surgery were based on the size of the aneurysm (all were large) and its position in relation to the dorsum sellae (eight were more than 5 mm below the level of the dorsum sellae). Good exposure of the neurovascular structures of the interpeduncular and prepontine cisterns (namely, the basilar artery) was obtained in all cases as compared with other well-established approaches to the area. All patients in our surgical series did well except that all incurred an expected third nerve palsy, caused by surgical manipulation, which resolved over the course of 2 weeks to 3 months. Although technically difficult, the transcavernous approach provides better exposure of the interpeduncular and prepontine cisterns relative to that afforded by other, more conventional approaches. The satisfactory results obtained in our preliminary series of patients greatly support the use of this approach for complex basilar tip aneurysms.