Frontolateral Approach Research Articles

Microsurgical resection of extensive craniopharyngiomas using a frontolateral approach: operative technique and outcome

An extensive craniopharyngioma is a tumor that extends into multiple compartments (subarachnoid spaces) and attains a size larger than 4 cm. A wide spectrum of approaches and strategies has been used for resection of such craniopharyngiomas. In this report the authors focused on the feasibility and efficacy of microsurgical resection of extensive craniopharyngiomas using a frontolateral approach. A retrospective analysis was performed on 16 patients with extensive craniopharyngiomas who underwent operations using a frontolateral approach at one institution. The preoperative and postoperative clinical and radiological data, as well as the operative videos, were reviewed. The main focus of the review was the extent of radical tumor removal, early postoperative outcome, and approach-related complications. Gross-total resection of craniopharyngioma was achieved in 14 (87.5%) of 16 cases. Early after surgery (within 3 months), 1 patient showed improvement in hormonal status, while in the remaining 15 patients it worsened. No major neurological morbidity was observed. Two patients experienced temporary psychotic disorders. Visual function improved in 6 patients and remained unchanged in 9. One patient experienced a new bitemporal hemianopsia. Three patients with features of short-term memory disturbances at presentation did show improvement after surgery. There were no deaths or significant approach-related morbidity in this patient series. Only 1 patient required revision surgery for a CSF leak. The safe and simple frontolateral approach provides adequate access even to extensive craniopharyngiomas and enables their complete removal with a reasonable morbidity and approach-related complication rate.

Electrophysiological Mapping of the Temporal Branch of the Facial Nerve

Minimized frontal and frontolateral approaches have been proposed for the clipping of aneurysms and for removal of deep-seated supra- and parasellar lesions. To avoid postoperative facial nerve palsy, anatomical studies have been conducted; however, only one electrophysiological investigation has been reported. We studied the course of the facial nerve in the temporal region and identify the optimal pterional keyhole craniotomy from the perspective of facial nerve protection. We stimulated the temporal branch of the facial nerve in nine healthy volunteers and identified its course electrophysiologically. Electromyographic (EMG) responses were recorded from the superior orbicularis oculi, corrugator, and frontal muscles. The course of the temporal branch of the facial nerve was identified by tracking the stimulation points that elicited the best EMG responses. The distances from the tragus to the canthus, the tragus to the point where the facial nerve crosses over the zygomatic arch, the tragus to the first nerve bifurcation, the tragus to the second nerve bifurcation, and from the orbit to the middle rami were 80.8 ± 1.8 mm, 40.2 ± 1.6 mm, 58.1 ± 2.8 mm, 79.1 ± 3.4 mm, and 16.4 ± 0.9 mm, respectively. We found that the temporal branch of the facial nerve innervates each muscle in posterior-anterior direction. Based on these results, we prefer the pterional keyhole approach and incise the skin at a site posterior to the temporal branch of the facial nerve.

Microsurgical Excision of Olfactory Groove Meningeomas, Comparative Studies of Different Surgical Approaches

To review the surgical approaches, techniques, outcomes, and recurrence rates in a series of 6 olfactory groove meningioma (OGM) patients operated from January 2010 to April 2011.Methods: Six patients underwent craniotomy and micro-neurosurgical removal of olfactory groove meningioma maximum. Tumor diameter varied from 5 to 8.5 cm among six cases, 2 cases underwent glabellar mini craniotomy another 2 by bifrontal approach and rest of them were by frontolateral approach. Result: Total removal was possible in all cases. Histopathology revealed typical meningioma (WHO grade 1). there was no operative mortality and no permanent focal neurological deficit except anosmia. One patient developed leak and two cases meningitis which was resolved by lumber drain and antibiotic therapy. No tumor recurrence within six months of followup. For the removal of large olfactory groove meningiomas we used three different surgical approaches: frontolateral approaches, bifrontal approach and glabellar mini craniotomy. We consider the frontolateral approach is an alternative, if not superior, to standard bifrontal approaches. DOI: http://dx.doi.org/10.3329/medtoday.v24i1.13942 Medicine TODAY Vol.24(1) 2012 pp.5-7

Preservation of olfaction in surgery of olfactory groove meningiomas

IntroductionOlfaction is commonly considered as secondary among the sensory functions, perhaps reflecting a lack of interest in sparing olfaction after surgery for the olfactory groove meningiomas (OGM). However, considering the repercussions of olfaction for the quality of life, the assessment of post-operative olfaction should be necessary. We retrospectively reviewed the olfactory outcome in patients with OGM and investigated the factors associated with sparing the post-operative olfaction. MethodsBetween 1993 and 2012, 40 patients with OGM underwent surgical resection and estimated the olfactory function using the Korean version of “Sniffin'Sticks” test (KVSS). Variable factors, such as tumor size, degree of preoperative edema, tumor consistency, preoperative olfactory function, surgical approaches, patient's age, and gender were analyzed with attention to the post-operative olfactory function. ResultsAnatomical and functional preservation of olfactory structures were achieved in 26 patients (65%) and 22 patients (55%), respectively. Among the variable factors, size of tumor was significant related to the preservation of post-operative olfaction. (78.6% in size <4cm and 42.3% in size >4cm, p=0.035). Sparing the olfaction was significantly better in patients without preoperative olfactory dysfunction (84.6%) compared with ones with preoperative olfactory dysfunction (40.7%, p=0.016). The frontolateral approach achieved much more excellent post-operative olfactory function (71.4%) than the bifrontal approach (36.8%, p=0.032). ConclusionsIf the tumor was smaller than 4cm and the patients did not present olfactory dysfunction preoperatively, the possibility of sparing the post-operative olfaction was high. Among the variable surgical approaches, frontolateral route may be preferable sparing the post-operative olfaction.

Surgical Removal of Giant Craniopharyngiomas via the Frontolateral Approach: Operative Technique and Analysis of the Outcome

Surgical Removal of Giant Craniopharyngiomas via the Frontolateral Approach: Operative Technique and Analysis of the Outcome

Expanded Endoscopic Endonasal Approaches to Skull Base Meningiomas

Anterior cranial base meningiomas have traditionally been addressed via frontal or frontolateral approaches. However, with the advances in endoscopic endonasal treatment of pituitary lesions, the transphenoidal approach is being expanded to address lesions of the petrous ridge, anterior clinoid, clivus, sella, parasellar region, tuberculum, planum, olfactory groove, and crista galli regions. The expanded endoscopic endonasal approach (EEEA) has the advantage of limiting brain retraction and resultant brain edema, as well as minimizing manipulation of neural structures. Herein, we describe the techniques of transclival, transphenoidal, transplanum, and transcribiform resections of anterior skull base meningiomas. Selected cases are presented.

Results after treatment of craniopharyngiomas: further experiences with 73 patients since 1997

The authors report surgical and endocrinological results of a series of 73 cases of craniopharyngioma that they treated surgically since 1997 to demonstrate their change in treatment strategy and its effect on outcome compared with a previous series and results reported in the literature. A total of 73 patients underwent surgery for craniopharyngiomas between May 1997 and January 2005. In patients with poor clinical or neuropsychological condition, even following pretreatment, only stereotactic cyst aspiration took place (8 cases). In the remaining patients, gross-total resection (GTR) was intended and appeared to be possible. The most frequent approaches were subfrontal (27 cases) and transsphenoidal (26 cases); in some cases, a multistep approach was used. The rate of GTR, complications, and functional outcome (comparing pre- and postoperative endocrine and neuropsychological testing) were evaluated. The mean duration of follow-up was 25.2 months. Gross-total resection was achieved in 88.5% of cases in which a transsphenoidal approach was used and 79.5% of those in which a transcranial approach was used (85.2% of those in which a subfrontal approach was used and 72.7% of those in which a frontolateral approach was used). In the total series, GTR was achieved in 83.1% of cases (vs 49.3% in the authors' former series). The complication rate was 13.8% without any mortality. New endocrine deficits were observed more frequently in patients treated with transcranial approaches over the years (16.3%-66.7% vs 2.6%-50.0%) but were less frequent after transsphenoidal approaches (5.2%-19.2% vs 2.9%-45.7%). Open surgery with intended total resection remains the treatment of choice in most patients. Initial stereotactic cyst aspiration or medical pretreatment to improve the patients' condition and adequate choice of surgical approach(es) are essential to achieve that goal. Nevertheless, a moderate increase in endocrinological deficits has to be accepted. The authors recommend using radiotherapy only in cases in which there are tumor remnants or disease progression after surgery.

Microneurosurgical treatment of massive tuberculum sellae meningiomas

To summarize the characteristics of the pathological anatomy and blood supply model of massive tuberculum sellae meningiomas (MTSM) and explore its corresponding microneurosurgical strategies. The clinical data of 16 MTSM patients were reviewed retrospectively. From January 1998 to January 2010, according to their unique pathological anatomy and blood supply model, all patients underwent microneurosurgical removal with induced hypotension through tumor corridor by the bi-subfrontal anterior longitudinal fission (n = 14), right frontolateral approach (n = 1) and pterional approach (n = 1). There were 5 males and 11 females with a mean age of 48.5 years old (range: 26 - 65). But the mean follow-up period was 74.9 months (range: 4 - 132) in 2/4 cases. Among all cases, the mean tumor diameter was 58.9 mm (range: 51.1 - 76.2 mm). Simpson grade I, II, III, IV removal of MTSMs were accomplished in 3, 9, 3 and 1 case respectively. One case died within 4 postoperative days. Visual acuity improved in 10 patients, remained unchanged in 2 and deteriorated in 2. Transient postoperative diabetes insipidus occurred in 9 cases. It is critical to understand the unique characteristics of pathological anatomy and blood supply model of MTSM so as to adopt proper microneurosurgical strategies to remove it in situ.

Frontolateral Approach for Anterior Cranial Fossa, Sellar, and Parasellar Tumors: Advantages and Technical Aspects

Introduction: Frontolateral craniotomy is a relatively small craniotomy is well established in skull base surgeries to deal with most of the anterior fossa, sellar, and parasellar lesions, providing adequate exposure and minimal brain retraction. Methods: A retrospective study was conducted of 83 cases, which occurred over the past 6 years, of different types of anterior cranial fossa, sellar, and parasellar tumors, which were approached through right frontolateral craniotomy. Discussion: A right frontolateral craniotomy that was 3 × 4 cm in dimension and flush with the roof of the orbit was used in all cases. We could achieve total resection in most of these tumors with minimal complications and good outcome. Different types of tumors were approached using this technique. Comparing our results with other approaches revealed better results with this minimally invasive technique regarding the total resection and follow-up. Conclusion: The frontolateral approach is minimally invasive, shortening operative time and minimizing morbidity.

Visualization of the Anterior Cerebral Artery Complex With a Continuously Variable-View Rigid Endoscope: New Options in Aneurysm Surgery

Neuroendoscopy is increasingly used as an adjunctive tool in intracranial aneurysm surgery. To assess the versatility of a prototype continuously variable-view rigid endoscope in visualizing the anterior cerebral artery complex. In 5 formaldehyde-fixed, arterially injected specimens, a standard frontolateral approach was used on both sides. After meticulous microsurgical dissection using this approach, the prototype of a multivariable rigid endoscope (EndoCAMeleon; Karl Storz GmbH & Co, Tuttlingen, Germany) was inserted. It is a rigid endoscope that is capable of changing its angle of view while remaining stationary and shape invariant. We inspected the anterior cerebral artery complex, using and testing the capabilities of the device. The continuously variable viewing mechanism enables the surgeon to adjust the field of view continuously and to optimize the visualization of the neurovascular structures. Because of the rigid tip combined with the continuously variable viewing mechanism, the need to move the endoscope within the surgical field was minimal. The field of view changes, but the tip itself hardly moves. The EndoCAMeleon was able to enhance both the visibility of the anterior cerebral artery complex and the accessibility of the A1 and A2 arterial walls to a range of approximately 270 degrees. The EndoCAMeleon enhances the visibility of the anterior cerebral artery complex and facilitates endoscope-assisted inspection, planning of clip application, and clip control.

Microsurgical management of tuberculum sellae meningiomas by the frontolateral approach: Surgical technique and visual outcome

Objectives The aim of this study was to evaluate visual outcome in patients with tuberculum sellae meningioma (TSM) treated microsurgically using the frontolateral or fronto-orbital approach and optic canal unroofing to resect tumor involvement of the optic canal. Methods Data from 67 patients with TSMs who underwent microsurgical treatment by a frontolateral approach ( n = 44) or fronto-orbital approach ( n = 23) between January 2002 and December 2008 were retrospectively collected and analyzed. Change in visual function was evaluated as the main outcome. Results Total tumor resection was achieved in 62 of 67 cases (92.4%). Postoperative, visual acuity was improved in 87 eyes (64.9%) and unchanged in 39 eyes (29.1%), and the optic nerve was therefore preserved in 126 of 134 eyes (94.0%). Visual field deficits were improved or stable in 65 eyes, no patient experienced worsening of vision in both eyes. There was no mortality in our series. Conclusions The frontolateral approach with microsurgical dissection of the Sylvian fissure provides quick access to TSMs, which can be resected safely and totally. Visual function is improved and neurological and ophthalmological morbidity is minimal. Optic nerve decompression by intradural clinoidectomy and optic canal unroofing is likely to increase the rate of reducing or eliminating preoperative visual symptoms.

Perspective of the frontolateral craniotomies

The pterional craniotomy is one of the most frequently surgical approaches used in neurosurgery and currently it has become a mainsteam. It allows excellent microsurgical exposure of anterior and posterior regions of the arterial circle of Willis, supra and paraselar regions, the superior orbital fissure of sphenoid bone, cavernous sinus, orbit, temporal lobe, midbrain and the frontal lobe. Like others techniques, the pterional craniotomy presented disadvantages related to dissection of the temporal muscle. From the first fronto lateral craniotomy described by Dandy to expose the optic chiasm and the pituitary we pass through the Yasargil's classical description of craniotomy centered in fronto-temporal sylvian fissure until reaching the recent"minipterional craniotomy", modifications of the pterional craniotomy were proposed to reduce the extra cranial tissue trauma and reduce the area of craniotomy without affecting the exposure of surgical targets, thus improving their aesthetic and functional results. An historical analysis of the frontolateral approaches has demonstrated that they have evolved from larger craniotomies to smaller ones, however only the minipterional craniotomy is able to offer similar surgical exposure.

Tuberculum sellar operation by frontolateral approach(32 cases report)

Objective To summary the methods in removing the tuberculum sellar menigiomas through frontolateral approach. Method 32 tuberculum sellar menigioma patients by frontolateral approach in the last 2.5 years in Beijing Tiantan Hospital were analyzed retrospectively . Simpson score were used to evaluate the tumor resection. Results Simpson score Ⅰ in 25 cases, Ⅱ in 5 cases, Ⅲ in 2 cases. Fever in 4 cases; Cerebrospinal fluid rhinorrhea in 1 case; electrolyte disturbances and hyperglucoses in 5 cases; visual deterioration in 2 cases. No dead patient was found. Follow up time was 1-28 months, mean 18 months. No recurrent tumor was observed. Conclusions The frontolateral approach has the advantage of shorter incision, less temporal muscle damage, integrity of frontal sinus, more olfactory nerve reservation, and better visual improvement Key words: Menigioma; Tuberculum sellar; Microsurgery

Validity of the frontolateral approach as a minimally invasive corridor for olfactory groove meningiomas

Several approaches are described for olfactory groove meningiomas (OGMs) varying from a very wide bifrontal craniotomy to minimally invasive endoscopic techniques. The goal of this study was to evaluate the results of the frontolateral approach for olfactory groove meningioma. Pitfalls related to this corridor will be described. The impact of tumor size and encasement of the anterior cerebral artery complex on the degree of tumor removal will be described on the basis of experience with 18 cases. Eighteen patients with OGM underwent microsurgical removal using the frontolateral approach. A retrospective study was conducted by analyzing clinical data, neuroimaging studies, operative findings, clinical outcome, and degree of tumor removal. The patients were classified into group A with tumor size less than 4 cm in diameter (7 out of 18 cases, 38.9%) and group B with tumor size more than 4 cm in diameter (11 out of 18 cases, 61.1%). CSF rhinorrhea was observed in three patients (16.7%). Postoperative left frontal intracerebral hematoma occurred in one patient (5.6%) belonging to group A. In another patient (5.6%) belonging to group B, marked right frontal lobe swelling was evident after dural opening, which necessitated partial right frontal pole resection. Total tumor removal (Simpson grade 1 and 2) was achieved in 14 out of 18 patients (77.8%), while subtotal removal (Simpson grade 3 and 4) was achieved in 4 patients (22.2%). In the 14 patients in whom total removal was achieved, 7 belonged to group A (all 7 patients of group A with 100% removal), while the remaining 7 patients belonged to group B (7 out of 11 patients, 63.6% removal; one of them had anterior cerebral artery complex encasement). The four patients in whom subtotal removal was achieved belonged to group B; three of them showed anterior cerebral artery complex encasement, and one elderly patient had non-extensive paranasal sinus involvement. One patient (5.6%) in group B died from cerebral infarction after subtotal tumor removal with anterior cerebral artery injury during its dissection from the tumor capsule. The frontolateral approach has the advantages of both the pterional and conventional bifrontal approaches. The frontolateral approach allows quick and minimally invasive access to OGMs less than 4 cm in diameter, and also to tumors more than 4 cm in diameter without encasement of the anterior cerebral artery complex. Tumor size more than 4 cm in diameter and encasement of the anterior cerebral artery complex are limiting factors for the frontolateral approach if radical tumor removal is considered.

Approaches and Results of Pituitary Surgery at King Hussein Medical Center and King Hussein Cancer Center in Amman, Jordan

Approximately 200 cases of pituitary adenomas and other rare pituitary tumors were operated on by a single surgeon at King Hussein Medical Center and King Hussein Cancer Center using the frontolateral approach, the direct endonasal transsphenoidal approach, and the endoscopic transsphenoidal approach. Good results were achieved, according to international standards. The approaches, surgical tricks, advantages, and disadvantages will be discussed and presented, stressing the fact that the first-mentioned approach (the frontolateral approach) provides the best opportunity to cure patients with Cushing's disease and acromegaly.

The Frontolateral Approach, Minicraniotomy Can Deal with Most Anterior Fossa, Sellar, and Parasellar Tumors with Minimal Brain Retraction, Good Surgical View, and Easy Handling

More than 100 cases of anterior cranial fossa sellar and parasellar region pathologies, including olfactory groove meningioma, craniopharyngioma, arachnoid cysts, and many others, were approached through a small 3 × 4-cm frontolateral craniotomy, which is simple, timesaving, and carries minimal risk of complications. This approach provides easy access to this region through which we can achieve total resection with minimal brain retraction and good outcome. It can also be performed through an eyebrow incision, which gives a good cosmetic result in some patients. Huge tumors like olfactory groove meningioma, of which we have 13 cases in our series, can be totally excised without complications. This work has been done by a single surgeon at King Hussein Medical Center and King Hussein Cancer Center.

OLFACTORY GROOVE MENINGIOMAS

Olfactory groove meningiomas account for 8 to 13% of all intracranial meningiomas. Surgical removal is often performed through the bifrontal, unilateral subfrontal (frontolateral), or pterional approach. We report on the clinical outcome and recurrence rate after surgical treatment of olfactory groove meningiomas in our neurosurgical department. A retrospective study was conducted by analyzing the charts of the patients, including surgical records, discharge letters, histological records, follow-up records, and imaging studies. A total of 1800 meningiomas were operated on between 1978 and 2002 in our department. There were 82 patients with olfactory groove meningiomas, including 63 women and 19 men with a mean age of 57.8 years (age range, 33-91 yr). Most patients presented with mental disturbance. Tumors were operated through the bifrontal (n = 46), frontolateral (n = 34), and pterional (n = 2) approaches. Total tumor removal (Simpson Grade 1 or 2) was achieved in most cases (91.2% frontolateral, 93.5% bifrontal). Perioperative mortality was 4.9% (four out of 82 patients, all operated through the bifrontal approach). The overall recurrence rate was 4.9%, with four patients requiring surgery. The mean follow-up period was 63.4 months (range, 4-270 mo). Olfactory groove meningiomas were removed mainly through two different surgical approaches. Even in large tumors, high rates of total tumor resection could also be achieved with low recurrence rates using the simple and minimally invasive frontolateral approach. In recent years, we have preferred to use the frontolateral approach, which provides quick access to the tumor with less brain exposure while still enabling total tumor removal with a low morbidity rate and no mortality.

Image-guided craniotomy for frontal sinus preservation during meningioma surgery

Objective Preservation of the frontal sinus (FS) during the frontolateral approach to the skull base reduces morbidity, enhances patient comfort, and speeds up the surgical procedure. Due to its irregular outline, mental reconstruction of the borders of FS from two-dimensional images is challenging during surgery. This study was designed to evaluate the impact of neuronavigation on identification and preservation of the FS during frontolateral craniotomies. Methods Forty-five patients with pathologies located in the anterior skull base and in the parasellar region were included. A standard computed tomography (CT) sequence was obtained from each patient and uploaded onto an image-guidance system for volumetric rendering of 3D images. The outline of the FS was visualized and the distance between its lateral border and the mid-pupillary line (MPL) was measured. The results were used for navigated craniotomies and compared to the intra-operative findings. Results The FS was located medial, on and lateral to the MPL in 32, 4 and 9 cases, respectively. The individual outline of the FS could be identified with a mean target registration error of 1.4 mm (±0.7 mm). The craniotomy could be custom-tailored for each patient according to the individualized landmarks while visualizing the lesion and the surgical landmarks simultaneously. Unintended opening of the frontal sinus or orbit did not occur in any of these cases. Conclusion Image-guided craniotomies based on 3D volumetric image rendering allow for fast and reliable demarcation of complex anatomical structures hidden from direct view in frontolateral approaches. The outline of the frontal sinus and the orbit can be appraised at a glance providing additional safety and precision during craniotomy.

OLFACTORY GROOVE MENINGIOMAS

Olfactory groove meningiomas account for 8 to 13% of all intracranial meningiomas. Surgical removal is often performed through the bifrontal, unilateral subfrontal (frontolateral), or pterional approach. We report on the clinical outcome and recurrence rate after surgical treatment of olfactory groove meningiomas in our neurosurgical department. A retrospective study was conducted by analyzing the charts of the patients, including surgical records, discharge letters, histological records, follow-up records, and imaging studies. A total of 1800 meningiomas were operated on between 1978 and 2002 in our department. There were 82 patients with olfactory groove meningiomas, including 63 women and 19 men with a mean age of 57.8 years (age range, 33-91 yr). Most patients presented with mental disturbance. Tumors were operated through the bifrontal (n = 46), frontolateral (n = 34), and pterional (n = 2) approaches. Total tumor removal (Simpson Grade 1 or 2) was achieved in most cases (91.2% frontolateral, 93.5% bifrontal). Perioperative mortality was 4.9% (four out of 82 patients, all operated through the bifrontal approach). The overall recurrence rate was 4.9%, with four patients requiring surgery. The mean follow-up period was 63.4 months (range, 4-270 mo). Olfactory groove meningiomas were removed mainly through two different surgical approaches. Even in large tumors, high rates of total tumor resection could also be achieved with low recurrence rates using the simple and minimally invasive frontolateral approach. In recent years, we have preferred to use the frontolateral approach, which provides quick access to the tumor with less brain exposure while still enabling total tumor removal with a low morbidity rate and no mortality.

Image-Guided Craniotomy for Frontal Sinus Preservation

Objective: Preservation of the frontal sinus (FS) during the frontolateral approach to the skull base reduces morbidity, enhances patient comfort, and speeds up the surgical procedure. Due to its irregular outline, mental reconstruction of the borders of FS from two-dimensional images is challenging during surgery. This study was designed to evaluate the impact of neuronavigation on identification and preservation of the FS during frontolateral craniotomies.