Microsurgical experience with supraorbital keyhole operations on anterior circulation aneurysms

'What's in a name', a systematic review of the pterional craniotomy for aneurysm surgery and its many modifications with a proposal for simplified nomenclature

BACKGROUND

The pterional or frontosphenotemporal craniotomy has stood the test of time and continues to be a commonly used method of managing a variety of neurosurgical pathology. Already described in the beginning of the twentieth century and perfected by Yasargil in the 1970s, it has seen many modifications. These modifications have been a normal evolution for most neurosurgeons, tailoring the craniotomy to the patients' specific anatomy and pathology. Nonetheless, an abundance of variations have appeared in the literature.

METHODS

A search strategy was devised according to the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. To identify articles investigating the variations in the pterional approach, the following search terms were applied: (pterional OR minipterional OR supraorbital) AND (approach OR craniotomy OR technique).

RESULTS

In total, 3552 articles were screened with 74 articles being read in full with 47 articles being included for review. Each article was examined according the name of the technique, temporalis dissection technique, craniotomy technique and approach.

CONCLUSION

This systematic review gives an overview of the different techniques and modifications to the pterional craniotomy since it was initially described. We advocate for the use of a more standardised nomenclature that focuses on the target zone to simplify the management approach to supratentorial aneurysms.

Cosmetic Outcomes of Supraorbital Keyhole Craniotomy Via Eyebrow Incision: A Systematic Review and Meta-Analysis

Background  Supraorbital eyebrow craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor and vascular pathologies. The purpose of this study was to investigate how patient cosmetic outcomes are affected by technique variations of this approach. Methods  PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to PRISMA guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used, and the primary end points were patient satisfaction and percentage of permanent cosmetic complications. Results  A total of 2,629 manuscripts were identified. Of those, 124 studies (8,241 surgical cases) met the inclusion criteria. Overall, 93.04 ± 11.93% of patients reported favorable cosmetic outcome following supraorbital craniotomy, and mean number of cases with permanent cosmetic complications was 6.62 ± 12.53%. We found that vascular cases are associated with more favorable cosmetic outcomes than tumor cases ( p  = 0.0001). Addition of orbital osteotomy or use of a drain is associated with adverse cosmetic outcomes ( p  = 0.001 and p  = 0.0001, respectively). The location of incision, size of craniotomy, utilization of an endoscope, method of cranial reconstruction, skin closure, use of antibiotics, and addition of pressure dressing did not significantly impact cosmetic outcomes ( p  > 0.05 for all). Conclusions  Supraorbital craniotomy is a minimally invasive technique associated with generally high favorable cosmetic outcomes. While certain techniques used in supraorbital keyhole approach do not pose significant cosmetic risks, utilization of an orbital osteotomy and the addition of a drain correlate with unfavorable cosmetic outcomes.

Supraorbital vs pterional keyhole for anterior circulation aneurysms: A systematic review and meta-analysis

Background

The supraorbital approach is a modification of the traditional pterional approach, and it offers the benefits of a shorter skin incision and a smaller craniotomy than the pterional approach. The purpose of this systemic review study was to compare the two surgical approaches for raptured and unruptured anterior cerebral circulation aneurysms.

Methods

We searched PubMed, EMBASE, Cochrane Library, SCOPUS, and MEDLINE, up to August 2021, for published studies on the supraorbital vs pterional keyhole approach for anterior cerebral circulation aneurysms, and reviewers performed a brief qualitative descriptive analysis of both approaches.

Results

Fourteen eligible studies were included in this systemic review. Results indicated that the supraorbital approach for anterior cerebral circulation aneurysms had fewer ischemic events compared to pterional approach. However, no significant difference between both groups in terms of complications such as intraoperative aneurysm rupture, brain hematoma, and postoperative infections for ruptured aneurysms.

Conclusion

The meta-analysis suggests that the supraorbital method for clipping anterior cerebral circulation aneurysms might be a viable alternative to the traditional pterional method as the supraorbital group had decreased ischemic events compared to the pterional group, however, the associated difficulties in utilizing this approach among ruptured aneurysms with cerebral oedema and midline shifts further needs to be understood.

Minimally invasive craniotomies for lesions of the anterior and middle fossa

Minimally invasive craniotomies are the subject of increasing attention over the last two decades in neurosurgery, following the current trend of attempting to increase patient safety by providing surgeries with less tissue disruption, blood loss, and decreased operative time. However, a significant information overlap exists among the various keyhole approaches regarding their indications and differences with more invasive techniques. Therefore, the present study aims to comprehensively review, illustrate, and describe the potential benefits and disadvantages of minimally invasive techniques to access the anterior and middle fossa, including the mini-pterional, mini orbito-zygomatic, supraorbital, lateral supraorbital, and extended lateral supraorbital approaches while comparing them to classic, more invasive approaches.

Factors affecting global neurocognitive status and frontal executive functions in the early stage after surgical clipping of unruptured anterior circulation aneurysms with respect to keyhole clipping and conventional clipping

PURPOSE

This study investigated the most significant factor for the preservation of the global neurocognitive status and frontal executive functions in the surgical clipping of unruptured anterior circulation aneurysms, specifically in keyhole and conventional clipping procedures.

METHODS

The prospective study that was performed to examine the effects of aneurysm surgery on the patient's global neurocognitive status and frontal executive functions started on April 2016. After exclusion posterior circulation aneurysms, anterior communicating aneurysms treated by interhemispheric approach, giant aneurysms, and paraclinoid aneurysms, 23 patients who were enrolled before May 2017 were treated by conventional clipping, and 18 patients who were enrolled after June 2017 were treated by keyhole clipping. Two patients were excluded from each group due to missing data. Finally, 21 and 16 patients in each group were analyzed, respectively. Three-tesla magnetic resonance imaging was performed before and after surgery to detect the presence of perioperative cerebral infarctions and brain edema. The Mini-Mental State Examination, Frontal Assessment Battery, and Self-Rating Depression Scale scores were obtained before and 1 month after surgery.

RESULTS

Logistic regression analyses indicated that anterior communicating and internal carotid artery aneurysms were the most significant factors for poor outcomes and that keyhole clipping for these two types of aneurysm was the most significant factor for the preservation of patient global neurocognitive status. Keyhole clipping was also the most significant factor for the preservation of frontal executive functions in patients.

CONCLUSIONS

Keyhole clipping may be more favorable than conventional clipping for the preservation of the global neurocognitive status and frontal executive functions. Moreover, it may be the most effective factor for preservation of global neurocognitive status when it is indicated for anterior communicating or internal carotid artery aneurysms.

Keyhole approach in anterior circulation aneurysm: Current indication, advantages, technical limitations, complications and their avoidance

Keyhole surgery recently evolved as a minimal invasive surgical approach for treatment of anterior circulation aneurysm. This review was done to evaluate the keyhole approach for anterior circulation aneurysms, their indications, advantages, technical limitations, complications and their avoidance. The literature review was performed with the phrase "keyhole approach for anterior circulation aneurysm" as a search term in PubMed central, Medline, Google scholar and Embase data base to identify all the articles published till December 2020. Out of 113 articles searched, 22 were included in this review after screening for eligibility. On analyzing these articles, there was total 2058 aneurysm in 1871 patients. Out of 2058 aneurysm, 988 were ruptured and 547 unruptured. In 5 studies, which include 344 aneurysms in 344 cases, aneurysm ruptured or unruptured status was not specified. The most frequent aneurysm site was anterior communicating artery (n=573). The size of the aneurysm mentioned in most of the study was <15 mm. The rate of complete occlusion was ranged from 93.6-100%. The range of intra operative rupture (IOR) was 0-28.6%. The mean operative time was ranged from 70 min-5.34 hours as reported in 13 studies. Good outcome [Glasgow outcome scale (GOS): 4-5] were seen in 75-100% cases. The frontalis muscle weakness has been reported in 3 studies and ranged from 0-1.99%. Keyhole surgery can be a safe and effective treatment modality for treatment of a selected anterior circulation aneurysm. In the experienced hand it has certain advantages over standard pterional craniotomy.

Supraorbital Keyhole Craniotomy via Eyebrow Incision: A Systematic Review and Meta-Analysis

BACKGROUND

Supraorbital eyebrow keyhole craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor resection and aneurysm clipping. The purpose of this study is to provide a contemporary review on the outcomes related to this approach and to determine whether they vary with the type of pathology and the addition of an endoscope.

METHODS

PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used.

RESULTS

A total of 2629 manuscripts were identified. of those, 124 studies (8241 surgical cases) met the inclusion criteria. Mean total complication rate was 26.7 ± 25.7% and the mean approach-related mortality rate was 1.3 ± 2.8%. Technical success, defined as gross total tumor resection or complete aneurysm clipping, was achieved in 83.6 ± 21.5% of the cases. Vascular pathologies were associated with greater technical success, lower total complications, and longer length of hospital stay compared with tumor cases (P < 0.05 for all). For vascular cases, addition of the endoscope yielded lower technical success (P = 0.001) and lower complication rate (P = 0.041). The use of the endoscope for tumor pathologies did not affect technical success, complications, mortality, length of hospital stay, operative time, or reoperation rate (P > 0.05).

CONCLUSIONS

The supraorbital craniotomy via an eyebrow incision is a feasible minimally invasive approach with an overall high technical success rate for both vascular and tumor pathologies.

The Supraorbital Approach via an Eyebrow Incision: Analysis of Cosmetic Outcomes Using the Scar Cosmesis Assessment Rating Scale

ABSTRACT

The supraorbital craniotomy through an eyebrow incision, referred to as the suprabrow approach, may be used to access intracranial lesions. Though offering good surgical exposure for anterior base cranial lesions, the suprabrow approach has a paucity of studies on its cosmetic outcomes. In this study, we aimed to assess the cosmetic outcomes of suprabrow approach using validated Scar Cosmesis Assessment Rating (SCAR) scale for the first time. Three patients underwent a suprabrow approach for resection of a suprasellar or frontal mass. Their postoperative courses were followed, with specific attention to the cosmetic outcome of their procedures. The SCAR scale was used to determine the cosmetic success of the approach. We found that all 3 patients scored ≤ 5 on the SCAR scale. All 3 resections were successful with no major postoperative complications. The only minor complication was transient hypoesthesia of the ipsilateral forehead that was noted in all 3 patients.This study quantified the positive cosmetic outcomes of a minimally invasive suprabrow approach. The suprabrow approach provides acceptable surgical exposure and access in an appropriately selected patient with anterior cranial base lesions and results in favorable cosmesis. Although transient hypoesthesia in the distribution of the ophthalmic branch of the trigeminal nerve occurs, the overall benefits of the approach and desirable cosmetic outcomes make the suprabrow approach a good technique to access intracranial lesions in appropriate cases.

How Safe and Effective Is Shifting from Pterional to Supraorbital Keyhole Approach for Clipping Ruptured Anterior Circulation Aneurysms? A Surgeon's Transition Phase Comparative Study

Background  Comparative studies between standard pterional and supraorbital keyhole approaches for aneurysms had potential biases with the heterogeneity of patient selection, differences among surgeons, or varying expertise across the surgeon's learning curve. This is a study of a surgeon's transition from pterional to keyhole approach for early clipping of selected consecutive ruptured anterior circulation aneurysms. Methods  Patients more than 18 years, presenting within 72 hours of ictus, in good clinical grades 1 to 3, no midline shift, with saccular aneurysms less than 25 mm at either communicating segment of internal carotid artery, anterior communicating artery, or middle cerebral artery segment till bifurcation were studied between the last 25 cases of pterional and first 25 cases of the keyhole, for the intraoperative and postoperative surgical outcome parameters. Results  There was no significant difference among baseline parameters, including the location of aneurysms across both groups. While only four cases of pterional had an intraoperative ventricular puncture, the lumbar drain was electively inserted in all keyhole patients. The intraoperative parameters, such as a dural tear, adequate parent vessel exposure, temporary clipping, and intraoperative rupture, did not show any significant difference. None had immediate postoperative deficits. While delayed cerebral ischemia and wound complaints were similar in both groups, temporal hollowing and chewing difficulty were significantly more in pterional patients( p = 0.01). Conclusion  A surgeon experienced in pterional approach can comfortably and safely shift to the keyhole for early clipping of selected ruptured aneurysms less than 25 mm, with a comparable surgical outcome but better cosmesis and mastication.

Orbital Rim Sparing Single-piece Fronto-orbital Keyhole Craniotomy Through Eyebrow Incision: A Technical Report and Comparative Review

Background

The classical eyebrow supraorbital keyhole craniotomy has limited working volume due to the thick incurving of the frontal bone necessitating generous drilling of the frontal base. However, the basal variant with sectioning of the orbital rim results in increased periorbital edema.

Objective

We describe a novel orbital rim sparing single-piece fronto-orbital keyhole approach, probably the first such report with a comparative review of relevant literature.

Methods

Following eyebrow incision, bidirectional drilling with a ball tip behind the fronto-zygomatic suture exposes the periorbita and frontal dura, with orbital roof in-between. The craniotomy is fashioned with an angled fronto-orbital cut parallel to and sparing the orbital rim with dura-guard over the periorbita, a frontal cut over the dura, and an optional cut along the lateral orbital roof from within the burr hole. A comparative review of this technique with traditional methods is also carried out.

Results

Compared to the classical supraorbital keyhole, this minimally invasive approach yields a wider basal exposure with greater working volume for intracranial and orbital lesions. Compared to the basal variant of keyhole fronto-orbital approach, this technique results in the least disturbance to periorbita's attachment with the orbital margin, maintenance of orbital contour, better cosmesis with use of simple tools and self-fitting flap.

Conclusion

The orbital rim sparing single-piece fronto-orbital keyhole craniotomy is an easy and novel minimally invasive approach with greater working volume without the disadvantages of sectioning the orbital rim.

Comparative study between minimally invasive supraorbital craniotomy and pterional craniotomy for treating anterior circulation cerebral aneurysms in a low-resource setting

The challenges encountered in performing minimally invasive approaches, such as supraorbital minicraniotomy (SOMC), in services without adequate equipment are rarely reported in the literature. This study analyzes the viability of SOMC in the treatment of cerebral aneurysms, using exactly the same resources as pterional craniotomy (PC). The results of these two techniques are compared. 35 patients underwent SOMC, compared to 50 patients underwent CP (100 aneurysms in total), using the same microsurgical instruments. The following variables were compared: operative time, angiographic cure, length of intensive care unit stay during the post-operative period, surgical complications, length of hospital stay after surgery until hospital discharge, intraoperative aneurysm rupture, aesthetic satisfaction with the scar, and neurological status at discharge. SOMC had a significantly shorter operative time in relation to PC (213.9 ± 11.09 min and 268.6 ± 15.44 min, respectively) (p = 0.0081).With respect to the cosmetic parameters assessed by the Visual Analog Scale, the average for SOMC was 94.12 ± 1.92 points, and the average for PC was 83.57 ± 4.75 points (p = 0.036). SOMC was as effective as PC in relation to successful aneurysm clipping (p = 0.77). The SOMC technique did not show advantages over PC in any other variable. Even in a general neurosurgery service lacking a specific structure for minimally invasive surgeries, SOMC was feasible and effective for treating intracranial aneurysms, using the same set of microsurgical instruments used for PC, obtaining better results in operating time and cosmetic satisfaction.

Eyebrow supraorbital keyhole craniotomy for olfactory groove meningiomas with endoscope assistance: case series and systematic review of extent of resection, quantification of postoperative frontal lobe injury, anosmia, and recurrence

BACKGROUND

Olfactory groove meningiomas (OGMs) are commonly treated with open craniotomy. Endonasal approaches have also been described.

OBJECTIVE

To present clinical and radiographic outcomes for the minimally invasive eyebrow incision supraorbital keyhole approach with endoscopic assistance for OGMs.

METHODS

We performed a retrospective single-center cohort study and a systematic literature review.

RESULTS

Fifteen patients were identified, all with Grade I meningiomas. Radiographic gross total resection of enhancing tumor was achieved in all patients. Mean frontal lobe fluid-attenuated inversion recovery volume decreased from 11.1 ± 18.3 cm³ preoperatively to 9.9 ± 11.4 cm³ immediately postoperatively, and there was minimal new restricted diffusion (3.2 ± 2.2 cm³; max 7.5 cm³). Median length of stay was 3 days (range 2-8). Vision was improved in 4 (80%) and stable in 1 (20%) of 5 patients with a preoperative deficit. New postoperative anosmia occurred in 3 (23%) of 13 patients with any preoperative olfaction. All patients were satisfied with their cosmetic result at 3 months. After a median follow-up of 32.2 months, there were 2 (13.3%) asymptomatic radiographic recurrences, 1 treated with radiosurgery and the other with endoscopic endonasal approach (EEA). No patients required further craniotomy. Systematic review revealed the present series to be the largest to date reporting disaggregated outcomes for the eyebrow approach to OGM.

CONCLUSION

The eyebrow incision supraorbital keyhole craniotomy with endoscopic assistance is a safe and effective approach to OGM with tumor control rates similar to more invasive open approaches and better than the endonasal approach. Rates of frontal lobe injury, CSF leak and anosmia are comparatively low.

[Bilateral supraorbital keyhole approach in surgery of multiple cerebral aneurysms: a case report and literature review]

The choice of an approach in surgery of bilateral multiple aneurysms is a complex and topical issue. According to the literature data, the occurrence rate of multiple aneurysms varies between 6.5 and 33%. Many authors have proposed various modern microsurgical approaches to reduce the risk of adverse surgical outcomes. The need for surgery in several vascular territories requires a detailed assessment of the topographo-anatomical relationships upon choosing a surgical approach. An important issue is preliminary planning and personalization of an approach for a particular patient.

MATERIAL AND METHODS

We report a case of clipping of mirror middle cerebral artery aneurysms using a minimally invasive bilateral approach.

RESULTS

The presented case demonstrates successful clipping of middle cerebral artery aneurysms in different vascular territories using the bilateral supraorbital approach: a skin incision along the eyebrow followed by supraorbital keyhole craniotomy. Follow-up CT angiography in the postoperative period demonstrated elimination of aneurysms from the bloodstream. The cosmetic effect after the intervention was evaluated as excellent.

CONCLUSION

The bilateral supraorbital approach in surgery of multiple mirror aneurysms may be recommended as an alternative to the contralateral or bilateral pterional approach. The bilateral supraorbital approach avoids additional traction of the frontal lobes, provides a focused personalized approach, and is a safe and effective approach with excellent cosmetic results.

Craniotomy Size for Subdural Grid Electrode Placement in Invasive Epilepsy Diagnostics

BACKGROUND

Traditionally, for subdural grid electrode placement, large craniotomies have been applied for optimal electrode placement. Nowadays, microneurosurgeons prefer patient-tailored minimally invasive approaches. Absolute figures on craniotomy size have never been reported. To elucidate the craniotomy size necessary for successful diagnostics, we reviewed our single-center experience.

METHODS

Within 3 years, 58 patients with focal epilepsies underwent subdural grid implantation using patient-tailored navigation-based craniotomies. Craniotomy sizes were measured retrospectively. The number of electrodes and the feasibility of the resection were evaluated. Sixteen historical patients served as controls.

RESULTS

In all 58 patients, subdural electrodes were implanted as planned through tailored craniotomies. The mean craniotomy size was 28 ± 15 cm2 via which 55 ± 16 electrodes were implanted. In temporal lobe diagnostics, even smaller craniotomies were applied (21 ± 11 cm2). Craniotomies were significantly smaller than in historical controls (65 ± 23 cm2, p < 0.05), while the mean number of electrodes was comparable. The mean operation time was shorter and complications were reduced in tailored craniotomies.

CONCLUSION

Craniotomy size for subdural electrode implantation is controversial. Some surgeons favor large craniotomies, while others strive for minimally invasive approaches. For the first time, we measured the actual craniotomy size for subdural grid electrode implantation. All procedures were straightforward. We therefore advocate for patient-tailored minimally invasive approaches - standard in modern microneurosurgery - in epilepsy surgery as well.

Supraorbital Keyhole Approach for Intracranial Aneurysms : Transitioning from Concerns to Confidence

For surgical minimalism to reduce iatrogenic traumatization, a supraorbital keyhole approach has already been successfully applied to treat many unruptured anterior circulation aneurysms. However, using this minimal approach also raises several technical concerns due to the small cranial opening and cosmetic impact of a facial incision. Yet, such technical limitations can be overcome by using favorable surgical indications, slender surgical instruments, and optimized surgical techniques, while excellent cosmetic outcomes can be achieved using a short skin incision located <1 cm from the supraorbital margin, reconstruction of any bone defects around the bone flap, and meticulous wound closure. Thus, given such reassuring surgical results, in terms of the clipping status, neurological effects, and cosmetic outcomes, any concerns can be transitioned into confidence.

A Comparative Study between Supraorbital Keyhole and Pterional Approaches on Anterior Circulation Aneurysms

Background

Many different conventional approaches such as the frontal and pterional approaches are used to access anterior circulation aneurysms. Recently, the supraorbital approach has been widely applied to the treatment of anterior circulation aneurysms. This study was done to evaluate which approach (pterional or supraorbital) has better outcomes in terms of residual neck post-clipping, cosmetic satisfaction, scar tenderness, complications and functional outcomes.

Methodology

A total of 123 patients were recruited into this study, comprising 82 patients who underwent a pterional approach and 41 patients who underwent a supraorbital approach. Computed tomography angiograms, the modified Rankin Scale, and the visual analogue scale were administered at 6 months to look for residual aneurysm, functional outcomes, scar tenderness, and cosmetic satisfaction. Complication data were collected from patients' case notes.

Results

The mean operating time for the pterional group was 226 min, compared to supraorbital group, which was 192 min (P = 0.07). Cosmetic satisfaction was significantly higher (P = 0.001) in the supraorbital group. There was no significant difference between the supraorbital and pterional groups' scar tenderness (P = 0.719), residual aneurysm (P = 0.719), or functional outcomes (P = 0.137), and there was no significant difference between the groups in terms of intra-operative and post-operative complications.

Conclusions

The supraorbital group had better cosmetic outcomes and shorter operating times compared to the pterional group.

Keyhole approaches for surgical treatment of intracranial aneurysms: a short review

Objective: To clarify the reported experience with keyhole approaches for the treatment of intracranial aneurysms. Methods: The PubMed and Embase databases were searched up to December 2017 for full-text publications that report the treatment of aneurysms with the eyebrow variant of the supraorbital craniotomy (SOC), the minipterional craniotomy, or the eyelid variant of the SOC. The anatomical distribution of aneurysms, the postoperative aneurysm occlusion rate, and the type and rate of complications were examined using univariate analysis. Results: Sixty-seven publications covering treatment of 5770 aneurysms met the eligibility criteria. The reported experience was the largest for the eyebrow variant of the SOC (69.4% of aneurysms), followed by the minipterional approach (28.2%), and the eyelid variant of the SOC (2.4%). The anterior communicating artery (ACoA) was the most frequent aneurysm location for the SOC (eyebrow variant: 33.2%; eyelid variant: 31.2%). The middle cerebral artery (MCA) was the most frequent aneurysm location in the minipterional cohort (55.2%). In the eyelid variant of the SOC cohort, the rate of complete aneurysm occlusion was the lowest (eyelid variant: 90.8%; eyebrow variant: 97.8%, p < 0.001; minipterional approach: 97.9%, p < 0.001), and the postoperative infarction rate was the highest (eyelid variant: 7.2%; eyebrow variant: 3.5%, p = 0.025; minipterional approach: 2.6%, p = 0.003). Conclusion: Each approach has a specific safety and efficacy profile. Surgeons selected the eyebrow variant of the SOC for many aneurysm locations including in particular the ACoA. There is a recent tendency however to opt for the minipterional approach above all for MCA aneurysms. Abbreviations: SOC: Supraorbital Craniotomy; MPT: Minipterional; MCA: Middle Cerebral Artery; ACoA: Anterior Communicating Artery; PCoA: Posterior Communicating Artery; aSAH: Aneurysmal Subarachnoid Hemorrhage; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; MINORS: Methodological Index For Non-Randomized Studies.

Minimally invasive medial supraorbital, combined subfrontal-interhemispheric approach to the anterior communicating artery complex-a cadaveric study

INTRODUCTION

In selected cases, microsurgical clipping remains a valuable treatment alternative to endovascular occlusion of anterior communicating artery (AComA) aneurysms. Their clipping is challenging and carries a risk of postsurgical cognitive impairment. We evaluate the microsurgical anatomy of a new, minimally invasive combined interhemispheric-subfrontal approach to the AComA complex via a medial supraorbital craniotomy.

METHODS

In this descriptive anatomic study, four alcohol-embedded, silicon-injected human cadaver heads were used. In each of the two cadavers, the AComA complex was approached from either the right or left side. An operating microscope and standard microsurgical instruments were used.

RESULTS

After a medial eyebrow incision, a medial supraorbital minicraniotomy was performed. The frontal sinus was opened and cranialized. Following the dural opening, a subfrontal arachnoid dissection was performed to identify the optico-carotid complex. By following the A1 segment, a low-lying AComA complex could be visualized. Shifting the corridor towards the midline enabled an interhemispheric dissection. This dissection resulted in a wide superior-inferior corridor. Higher-lying AComA complexes could also be visualized. The achieved exposure of the AComA complex would allow safe dissection and clipping of low- and high-lying AComA aneurysms, with minimal retraction and preservation of the surrounding anatomical structures, in particular the perforators.

CONCLUSIONS

We demonstrate the anatomy of a novel approach for surgical clipping of AComA aneurysms. Our study suggests that this approach provides good exposure without concomitant structural and vascular injury and thus might reduce the risk of procedure-related morbidity.

[Supraorbital keyhole craniotomy in surgery of anterior circle of willis aneurysms]

The progress in surgical treatment of intracranial aneurysms is based on the introduction of modern minimally invasive techniques. Among the variety of keyhole approaches, supraorbital craniotomy is most often used in surgical treatment of anterior circle of willis aneurysms. The authors present the preliminary results of application of supraorbital keyhole craniotomy for anterior circle of willis aneurysms in 27 patients. Most of the patients had unruptured aneurysms (18 patients). Nine patients had SAH, and 4 of them were operated on in the acute period. The patients' condition was assessed as a grade 1-2 (Hunt-Hess scale) and grade 1-3 (Fisher scale). There were no intraoperative aneurysm ruptures, other serious complications, and deaths. Postoperative complications were assessed at 2 weeks and 6 months. The postoperative cosmetic outcome was assessed by patients as excellent.

Influencing Factors Analysis of Facial Nerve Function after the Microsurgical Resection of Acoustic Neuroma

Objective

To explore and analyze the influencing factors of facial nerve function retainment after microsurgery resection of acoustic neurinoma.

Methods

Retrospective analysis of our hospital 105 acoustic neuroma cases from October, 2006 to January 2012, in the group all patients were treated with suboccipital sigmoid sinus approach to acoustic neuroma microsurgery resection. We adopted researching individual patient data, outpatient review and telephone followed up and the House-Brackmann grading system to evaluate and analyze the facial nerve function.

Results

Among 105 patients in this study group, complete surgical resection rate was 80.9% (85/105), subtotal resection rate was 14.3% (15/105), and partial resection rate 4.8% (5/105). The rate of facial nerve retainment on neuroanatomy was 95.3% (100/105) and the mortality rate was 2.1% (2/105). Facial nerve function when the patient is discharged from the hospital, also known as immediate facial nerve function which was graded in House-Brackmann: excellent facial nerve function (House-Brackmann I–II level) cases accounted for 75.2% (79/105), facial nerve function III–IV level cases accounted for 22.9% (24/105), and V–VI cases accounted for 1.9% (2/105). Patients were followed up for more than one year, with excellent facial nerve function retention rate (H-B I–II level) was 74.4% (58/78).

Conclusion

Acoustic neuroma patients after surgery, the long-term (≥1 year) facial nerve function excellent retaining rate was closely related with surgical proficiency, post-operative immediate facial nerve function, diameter of tumor and whether to use electrophysiological monitoring techniques; while there was no significant correlation with the patient’s age, surgical approach, whether to stripping the internal auditory canal, whether there was cystic degeneration, tumor recurrence, whether to merge with obstructive hydrocephalus and the length of the duration of symptoms.

Minimally Invasive Supraorbital Key-hole Approach for the Treatment of Anterior Cranial Fossa Meningiomas

The most important target of minimally invasive surgery is to obtain the best therapeutic effect with the least iatrogenic injury. In this background, a pivotal role in contemporary neurosurgery is played by the supraorbital key-hole approach proposed by Perneczky for anterior cranial base surgery. In this article, it is presented as a possible valid alternative to the traditional craniotomies in anterior cranial fossa meningiomas removal. From January 2008 to January 2012 at our department 56 patients underwent anterior cranial base meningiomas removal. Thirty-three patients were submitted to traditional approaches while 23 to supraorbital key-hole technique. A clinical and neuroradiological pre- and postoperative evaluation were performed, with attention to eventual complications, length of surgical procedure, and hospitalization. Compared to traditional approaches the supraorbital key-hole approach was associated neither to a greater range of postoperative complications nor to a longer surgical procedure and hospitalization while permitting the same lesion control. With this technique, minimization of brain exposition and manipulation with reduction of unwanted iatrogenic injuries, neurovascular structures preservation, and a better aesthetic result are possible. The supraorbital key-hole approach according to Perneckzy could represent a valid alternative to traditional approaches in anterior cranial base meningiomas surgery.

Endoscopic Fluorescence Angiography with Indocyanine Green : A Preclinical Study in the Swine

OBJECTIVE

Microscopic indocyanine green (ICG) angiography is useful for identifying the completeness of aneurysm clipping and the preservation of parent arteries and small perforators. Neuroendoscopy is helpful for visualizing structures beyond the straight line of the microscopic view. We evaluated our prototype of endoscopic ICG fluorescence angiography in swine, which we developed in order to combine the merits of microscopic ICG angiography and endoscopy.

METHODS

Our endoscopic ICG system consists of a camera, a light source, a display and software. This system can simultaneously display real-time visible and near infrared fluorescence imaging on the same monitor. A commercially available endoscope was used, which was 4 mm in diameter and had an angle of 30°. A male crossbred swine was used.

RESULTS

Under general anesthesia, a small craniotomy was performed and the brain surface of the swine was exposed. ICG was injected via the ear vein with a bolus dose of 0.3 mg/kg. Visible and ICG fluorescence images of cortical vessels were simultaneously observed on the display monitor at high resolution. The real-time merging of the visible and fluorescent images corresponded well.

CONCLUSION

Simultaneous visible color and ICG fluorescent imaging of the cortical vessels in the swine brain was satisfactory. Technical improvement and clinical implication are expected.

Keyhole Approach Combined With External Ventricular Drainage for Ruptured, Poor-Grade, Anterior Circulation Cerebral Aneurysms

Poor-grade ruptured anterior circulation cerebral aneurysms are frequently associated with severe vasospasm and high morbidity rates despite recent remarkable advances in endovascular coiling.Here, we explored the feasibility of keyhole approach combined with external ventricular drainage for ruptured, poor-grade, anterior circulation cerebral aneurysms. We retrospectively assessed the records of 103 patients with ruptured, Hunt and Hess grade IV or V, anterior circulation cerebral aneurysms. The patients were divided into 2 groups (conservative group and surgical group). In surgical group, patients were divided into 2 subgroups according to surgical time (within 24 hours and at 24-48  hours). Clinical outcome was assessed at the 6-month follow-up and categorized according to modified Rankin Scale (mRS) score.Twenty percent of patients (9/44) in conservative group obtained good outcome, while 54% (32/54) in surgical group (P < 0.05). Mortality was 73% in conservative group and 40% in surgical group, respectively. In surgical group, age, Hunt and Hess grade (IV or V), and timing of intervention (<24  hours or later) influenced the clinical outcome of the patients (P < 0.05), while sex, Fisher grade, hydrocephalus, the location of aneurysms, and cerebral vasospasm (CVS) not (P > 0.05). Furthermore, 65% of patients (22/34) operated within 24  hours after onset of hemorrhage had a good outcome compared with 20% of patients (5/25) operated at 24 to 48  hours in surgical group (P < 0.05).The results indicate that keyhole approach combined with external ventricular drainage is a safe and reliable treatment for ruptured, poor-grade, anterior circulation cerebral aneurysms in early stage, which will reduce mortality.

The extended transorbital craniotomy: an anatomic study

BACKGROUND

Supra-/transorbital approaches are mostly limited to suprasellar and anterior fossa pathologies, whereas lateral supraorbital approaches provide less retrosellar exposure and less overall operative volume, especially in the temporal region.

OBJECTIVE

Our cadaveric study proposes removal of the lesser and greater wings of the sphenoid bone to increase both the lateral angle typically achieved with pterional approaches and exposure to the temporal lobe and perisellar region.

METHODS

In 5 cadaveric specimens, our 3 steps to expand transorbital exposures included the following: step 1, standard transorbital craniotomy via a 3-cm supra-eyebrow incision; step 2, removal of the lesser sphenoid wing completed extradurally; and step 3, partial removal of the greater sphenoid wing. Operative extension in sylvian, parasellar, and anterolateral temporal exposures were quantified for each step (t test).

RESULTS

Step 2 provided the greatest increased exposure in the sylvian and parasellar regions compared with step 3, whereas step 3 provided a significant proportion of the exposure in the lateral temporal region. Finally, the lateral view progressively increased with each subsequent step.

CONCLUSION

Our 3-step removal of the lesser and greater wings of the sphenoid bone quantified increased sylvian, anterior temporal, and parasellar exposures for this minimally invasive approach with excellent cosmesis. Its increases the anterolateral view (similar to a subfrontal pterional approach) and offers potential applications to vascular and neoplastic (ie, sphenoid meningiomas) pathologies classically treated via a pterional or frontotemporal orbitozygomatic approach.

Tumors of the anterior skull base

A variety of histologic tumor types are present in the anterior skull base. Primary tumors of this area may be derived from the bone, paranasal sinuses, nasopharynx, dura, cranial nerves, pituitary gland and brain. Symptoms are caused mostly through mass effect but, if the tumor becomes aggressive, also through invasion. Selection of surgical approaches to the anterior skull base is based upon balancing risk reduction with maximizing extent of resection. Here we review a spectrum of neoplastic entities found in the anterior skull base in adults and discuss clinical and radiographic presentation, treatment options, and outcomes. Surgical resection remains the mainstay in treatment of these tumors, particularly in the hands of experienced surgeons exercising proper patient and case selection.

What is the Best Route to the Meckel Cave? Anatomical Comparison between the Endoscopic Endonasal Approach and a Lateral Approach

Background Traditionally, a pterional approach is utilized to access the Meckel cave. Depending on the tumor location, extradural dissection of the Gasserian ganglion can be performed. An endoscopic endonasal access could potentially avoid a craniotomy in these cases. Methods We performed an endoscopic endonasal approach as well as a lateral approach to the Meckel cave on six anatomic specimens. To access the Meckel cave endoscopically, a complete sphenoethmoidectomy and maxillary antrostomy followed by a transpterygoid approach was performed. For lateral access, a pterional craniotomy with extradural dissection was performed. Results The endoscopic endonasal approach allowed adequate access to the Gasserian ganglion. All the relevant anatomy was identified without difficulty. Both approaches allowed for a similar exposure, but the endonasal approach avoided brain retraction and improved anteromedial exposure of the Gasserian ganglion. The lateral approach provided improved access posterolaterally and to the superior portion. Conclusion The endoscopic endonasal approach to the Meckel cave is anatomically feasible. The morbidity associated with brain retraction from the open approaches can be avoided. Further understanding of the endoscopic anatomy within this region can facilitate continued advancement in endoscopic endonasal surgery and improvement in the safety and efficacy of these procedures.

Comparative Analysis of the Mini-pterional and Supraorbital Keyhole Craniotomies for Unruptured Aneurysms with Numeric Measurements of Their Geometric Configurations

Objective

Keyhole craniotomy is a modification of pterional craniotomy that allows for use of a minimally invasive approach toward cerebral aneurysms. Currently, mini-pterional (MPKC) and supraorbital keyhole craniotomies (SOKC) are commonly used. In this study, we measured and compared the geometric configurations of surgical exposure provided by MPKC and SOKC.

Methods

Nine patients underwent MPKC and four underwent SOKC. Their postoperative contrast-enhanced brain computed tomographic scans were evaluated. The transverse and longitudinal diameters and areas of exposure were measured. The locations of the anterior communicating artery, bifurcation of the middle cerebral artery (MCAB), and the internal carotid artery (ICA) terminal were identified, and the working angles and depths for these targets were measured.

Results

No significant differences in the transverse diameters of exposure were observed between MPKC and SOKC. However, the longitudinal diameters and the areas were significantly larger, by 1.5 times in MPKC. MPKC provided larger operable working angles for the targets. The angles by MPKC, particularly for the MCAB, reached up to 1.9-fold of those by SOKC. Greater working depths were required in order to reach the targets by SOKC, and the differences were the greatest in the MCAB by 1.6-fold.

Conclusion

MPKC provides larger exposure than SOKC with a similar length of skin incision. MPKC allows for use of a direct transsylvian approach, and exposes the target in a wide working angle within a short distance. Despite some limitations in exposure, SOKC is suitable for a direct subfrontal approach, and provides a more anteromedial and basal view. MCAB and posteriorly directing ICA terminal aneurysms can be good candidates for MPKC.

The quality of life of patients with good outcomes after anterior circulation aneurysm surgery assessed by the world health organization quality of life instrument-korean version

Objective

Even in the patients with neurologically good outcome after intracranial aneurysm surgery, their perception of health is an important outcome issue. This study aimed to investigate the quality of life (QOL) and its predictors of patients who had a good outcome following anterior circulation aneurysm surgery as using the World Health Organization Quality of Life instrument-Korean version.

Methods

We treated 280 patients with 290 intracranial aneurysms for 2 years. This questionnaire was taken and validated by 99 patients whose Glasgow Outcome Scale score was 4 and more and Global deterioration scale 3 and less at 6 months after the operation, and 85 normal persons. Each domain and facet was compared between the two groups, and a subgroup analysis was performed on the QOL values and hospital expenses of the aneurysm patients according to the type of craniotomy, approach, bleeding of the aneurysm and brain injury.

Results

Aneurysm patients showed a lower quality of life compared with control patients in level of independence, psychological, environmental, and spiritual domains. In the environmental domain, there were significant intergroup differences according to the type of craniotomy and the surgical approach used on the patients (p<0.05). The hospital charges were also significantly different according to the type of craniotomy (p<0.05).

Conclusion

Despite good neurological status, patients surgically treated for anterior circulation aneurysm have a low quality of life. The craniotomy size may affect the QOL of patients who underwent an anterior circulation aneurysm surgery and exhibited a good outcome.

Minimally invasive approaches to the anterior skull base

The use of minimally invasive approaches to the anterior skull base is a valuable tool to improving the treatment in patients with aggressive anterior skull base neoplasms. This article discusses the history, advantages and disadvantages relative to open approaches, the corridors and pathways used in approach, the equipment and operating room setup, perioperative care, and complication avoidance. Although outcomes are difficult to compare to open approaches, due to often small and varying patient cohorts, these approaches continue to gain acceptance as an effective treatment of anterior skull base tumors in the experienced surgeon's hands with proper patient selection.