Lateral Supraorbital Approach Research Articles

Anterior clinoidectomy for paraclinoid aneurysms in Helsinki Neurosurgery.

Background:In this video abstract, we present an intradural anterior clinoidectomy for management of some paraclinoid aneurysms. Quick adenosine cardiac arrest performed instead of an anterior clinoidectomy and proximal temporary clipping usually allows us a proximal control of aneurysms in Helsinki Neurosurgery. However, when the neck of the aneurysm remains hidden under the anterior clinoid process, or when some complex aneurysms have reduced space for placing temporary clips obstructing the definitive clipping, anterior clinoidectomy is the most available option.Technique:The patient with multiple intracranial aneurysms had a ruptured anterior cerebral artery aneurysm associated with a right middle cerebral artery aneurysm and a right small paraclinoid aneurysm. The patient underwent surgical clipping of all aneurysms by a right lateral supraorbital approach at one-stage surgery. After the associated aneurysms were clipped, the hidden paraclinoid aneurysm required an anterior clinoidectomy for definitive clipping. A small durotomy over the anterior clinoid process was made with microscissors after bipolar coagulation. Subsequently, the anterior clinoidectomy was performed under visual control with the use of an electric high-speed diamond drill (3 mm diameter). The direction and size of the drilling were performed according to the anatomical configuration and exact location of the aneurysm determined by the preoperative radiological analysis of the case. A definitive clip was applied after complete visualization of aneurysm. Postoperative computed tomography angiography demonstrated absence of complications.Conclusion:Anterior clinoidectomy is a useful procedure aiming at a proper definitive clipping of paraclinoid aneurysms with challenging locations and configurations.Videolink:http://surgicalneurologyint.com/videogallery/right-clinoidectomy/

Double-clip technique: An effective clipping technique for small and very small aneurysms.

Background:In this video abstract, we present a double-clip technique for the management of small (≤5 mm) and very small (≤3 mm) aneurysms with a suitable configuration to apply two clips. This is a parallel duplication clipping technique of booster clipping which uses mini-clips that have a smaller closing force compared to standard clips. This technique prevents the slippage of the applied clips, was developed along the career of the senior author (Juha Hernesniemi), and has been previously proved to be safe and effective for aneurysm clipping.Technique:The patient with a familial left small (4 × 3 mm) unruptured paraclinoid aneurysm is placed in the supine position. A left lateral supraorbital approach is performed. After opening the carotid cistern, the aneurysm is discovered under a careful microsurgical dissection. With an exposed aneurysm, cardiac arrest and hypotension produced by adenosine intravenous administration reduces the intravascular and intra-aneurysmatic pressure, and allow us a proximal control of the aneurysm without the use of the conventional temporary clipping (TC). In this regard, quick adenosine cardiac arrest is performed instead of an anterior clinoidectomy and proximal TC, whether the neck of the small paraclinoid aneurysm remains visible, but the space for placing TC is too reduced that may difficult the definitive clipping. According to our experience, the use of adenosine (0.2–0.4 mg/kg/dose) in multiple doses up to 87 mg/patient/surgery did not have any effect on the patient outcome. However, a very close collaboration between the surgeon and the anesthesiologist is required. After vascular control is ensured, an initial definitive mini-clip is applied, and a small residual neck sufficient for application of the second mini-clip is left. A second mini-clip with similar morphology to the first one is applied on the residual neck parallel and running in the same direction to the initial clip. With this, the slippage of the proximal mini-clip is prevented. Moreover, the synergic force of both clips ensures a proper occlusion of the aneurysm. Postoperative computed tomography angiography demonstrated absence of complications.Conclusion:The double-clip technique, a variation of booster clipping is an effective procedure to ensure a proper occlusion of small and very small aneurysms.Videolink:http://surgicalneurologyint.com/videogallery/double-clipping-technique/

Microsurgical clipping of a large ruptured anterior communicating artery aneurysm.

Background:Anterior communicating artery (AComA) aneurysms are the most complex aneurysms of the anterior cerebral circulation. They mostly arise between the dominant A1 and the AComA, and are associated with intraventricular hemorrhage or other aneurysms in around 20%–30% of the cases. Giant and fusiform aneurysms are rare in this location in contrast to the common small ruptured aneurysms. Throughout the treatment, branches of A1–A2 complex such as the orbitofrontal artery, the frontopolar artery, the recurrent artery of Heubner, medial lenticulostriate arteries, and small perforators from the A1–A2 junction should be preserved. The orientation of the aneurysm, undefined in case of tortuous A1, but usually to the contralateral side of the dominant A1, might be downward, forward, upward, backward, or even of a complex morphology. Moreover, the evaluation of the chiasm and skull base, the site of possible rupture, the presence of intraluminal thrombosis, vascular calcifications, or anatomic variations of A1 and A2 segments is required. Since the angle between the AComA perforators and the A2s varies between 30° and 180°, parallel application of the clip along the AComA is unrecommended.Technique:The patient with large ruptured AComA aneurysm underwent supine position. The head, placed above the cardiac level, was minimal extended, and slightly tilted and rotated to the opposite side according to the projection of the aneurysm dome. A left lateral supraorbital approach was performed. The carotid cistern and the lamina terminalis were opened to release cerebrospinal fluid. Arachnoid bands extending from the olfactory triangle to the lateral side of the optic nerve were carefully dissected to find the ipsilateral A1 and the aneurysm. Skillful dissection of the AComA complex under repeated temporary and pilot clips allowed a safe definitive clipping. Occasionally, aneurysm remodeling and shrinking under bipolar coagulation might be required. Intraoperative angiography and/or Doppler ultrasound determine complete occlusion of the aneurysm and patency of the vessels.Conclusion:Skillful microneurosurgery is required for the management of challenging ruptured AComA aneurysms.Videolink:http://surgicalneurologyint.com/videogallery/ruptured-acoma-aneurysm-14

The modified lateral supraorbital approach

Purpose: Lateral supraorbital approach is a simpler and quicker method than pterional approach. It provides a more anterior projection when compared to the pterional approach. There are some minor differences of the modified lateral supraorbital approach when compared to lateral supraorbital approach. It is directed more subfrontally and anterior than the pterional and lateral supraorbital approach.Material and methods: We used modified lateral supraorbital approach in 100 cases between 2012 and 2015 in Medical Park İzmir Hospital/Turkey. The assessed data were as follows: age, gender, Glasgow coma scale at admission, the localization of pathology, the condition of surgical obliteration for aneurysm, excision grade for meningioma, length of stay in the hospital and Glasgow outcoma scale at discharge.Results: Of all patients, 58 (58%) were men and 42 (42%) were women. Our cases were anterior communicating artery aneurysms (41 cases), tuberculum sella and medial sphenoid wing meningiomas (22 cases), middle cerebral artery aneurysms (15 cases), olfactory groove meningiomas (15 cases), anterior choroidal artery aneurysms (4 cases) and posterior communicating artery aneurysms (3 cases). 4 patients died and the mortality rate of the study cohort was 4%.Conclusions: The MLSA is faster, simpler and less invasive than the PA and LSA.

Clinical analysis of lateral supraorbital microsurgical approach for ruptured anterior circulation aneurysm

Objective: To explore the safety and efficiency of lateral supraorbital (LSO) approach for the ruptured anterior circulation aneurysm. Methods: The clinical data of 23 patients with grade Ⅰ-Ⅲ ruptured anterior circulation aneurysm via LSO at the Second Hospital of Shandong University from February 2016 to December 2016 were retrospectively analyzed. The clinical data included their clinical manifestations, radiological finding, microsurgical techniques and follow-up results. Results: All patients were diagnosed as anterior circulation aneurysm by preoperative CT angiography (CTA) or Digital Subtraction Angiography (DSA). They all accepted aneurysm clipping via LSO. The operations carried out smoothly, with no operation related complications. They were followed up for 2 to 12 months, and the Glasgow outcome scales (GOS) were 5 in 18 patients (78.3%), 4 in 2 patients (8.7%), 3 in 2 patients (8.7%), and 1 in 1 patient (4.3%). Conclusion: LSO could provide adequate exposure for the anterior circulation aneurysm, so the clipping could be carried out safely and effectively. LSO is a simple and minimally invasive surgical approach, and when it is used by the skilled master of pterion approach, its advantage could be fully played.

Anterior Midline Skull Base Meningiomas: Interhemispheric Approach versus the Different Classical Surgical Approaches—Clinical Outcomes

Backgrounds: Different surgical approaches have been used to remove anterior skull base meningiomas (ASBMs) such as olfactory groove (OG) and tuberculum sellae (TS) meningiomas. These tumors are traditionally resected through pterional (PT), lateral supraorbital (LS) approaches. The endonasal endoscopic (EE) approach has gained some attention in recent years. The interhemispheric (IH) approach represents another option that has been rarely described and even more rarely compared with other approaches.

A 16 Year Experience with Modified Lateral Supraorbital Approach for Ruptured Cerebral Aneurysms

Objectives: Upto now, most authors reported the supraorbital approach for unruptured aneurysm and small and less complex aneurysm. The authors devised the Modified Lateral Supraorbital (MLSO) approach. We present a 16 year experience with MLSO approach for ruptured anterior circulation aneurysms and some parts of posterior circulation aneurysms. Materials and Methods: Aneurysm clipping surgery through the MLSO approach was performed on a total 323 patients. Baseline demographics, operative time, procedural complications, and clinical outcomes at 6 months and 1 year were retrospectively analyzed. Results: For patients treated MLSO approach, 293 had single aneurysms and 30 had multiple aneurysms. The proportion of small, medium, large, and giant aneurysms were 64% (206/323), 31% (101/323), 4.7% (15/323), and 0.3% (1/323). Mean operation time was 219.6 minutes. Procedural complications occurred in 21 cases (6.5%). Five patients died from severe brain swelling and refusal of additional treatment, while 1 patient died from tonsilar herniation due to lumbar catheter drainage. Favorable clinical outcomes, Glasgow Outcome Scale IV or V, were observed in 82.6% (267/293) and 83.6% (270/293) at 6 months and one year follow-up. The MLSO approach has the following advantages: less brain retraction, good surgical field for high positioned A-com or basilar tip aneurysm surgery, short operation time, small skin incision, minimizing temporal muscle manipulation and good cosmetic appearance. Conclusions: The MLSO approach can be considered as a useful approach for neurosurgeons for cases of general ruptured aneurysm, except those with a large amount of intracerebral hemorrhage and severe brain swelling.

Early postoperative results of surgical treatment of patients with anterior clinoidal meningiomas

To evaluate the radicalness of microsurgical removal and a neurological deficit in the early postoperative period in patients with anterior clinoidal meningiomas. A total of 35 patients with anterior clinoidal meningiomas underwent surgery at the Department of Neurooncology of the Novosibirsk Federal Neurosurgical Center in the period from 2013 to July 2016. There were 29 (82.9%) females and 6 (17.1%) males. The mean patient age was 50.1 years (31-72 years). According to the Al-Mefty classification (1990), type 1 tumors occurred in 10 (28.6%) patients, type 2 tumors were in 22 (62.8%) patients, and type 3 tumors were in 3 (8.6%) patients. Twenty four (68.6%) patients had large (greater than 4.0 cm) tumors, 7 (20.0%) patients had medium (2.0-4.0 cm) tumors, and 4 (11.4%) patients had small (less than 2.0 cm) meningiomas. The tumor involved the major arteries in 21 (60.0%) patients. The lateral supraorbital approach was used in 26 (74.3%) patients, and the pterional approach was used in 9 (25.7%) cases. The tumor was resected totally (Simpson II) in 25 (71.4%) cases and subtotally (Simpson IV, subtype A and B) in 10 (28.6%) patients. In the early postoperative period, cerebral symptoms regressed in 20 (57.1%) patients; visual acuity improved in 2 of 13 (15.4%) patients. Four (11.4%) patients developed IIIrd nerve palsy; 2 (5.7%) patients developed severe hemiparesis. The mortality rate was 2.9%. The completeness of resection directly depends on the tumor consistency: soft meningiomas can be totally resected (Simpson II) with a good functional outcome. In the case of solid tumors, total resection may lead to serious ischemic disorders with a high risk of death.

The Extended Lateral Supraorbital Approach and Extradural Anterior Clinoidectomy Through a Frontopterio-Orbital Window: Technical Note and Pilot Surgical Series

Lateral approaches to treat anterior cranial fossa lesions have evolved since the first frontotemporal approach described by Dandy in 1918. We describe a less invasive approach to perform extradural anterior clinoidectomy through a lateral supraorbital (LSO) approach for anterior circulation aneurysms and anterolateral skull base lesions. The extended LSO approach involves performing a standard lateral supraorbital craniotomy followed by drilling of the sphenoid wing and lateral wall of the orbit through the frontal bony opening of the LSO approach, without any temporal extension of the craniotomy. This creates a frontopterio-orbital window exposing the periorbita; superior, medial, and anterior aspect of the temporal dura mater; and superior orbital fissure. After unroofing the superior orbital fissure, the meningo-orbital fold is cut, and the temporal dura mater is peeled from the lateral wall of the cavernous sinus to expose the anterior clinoid process allowing a standard opening of the optic canal and anterior clinoidectomy. The extended LSO approach and extradural anterior clinoidectomy allowed access to 4 sphenoid wing/anterior clinoidal meningiomas, 5 anterior circulation aneurysms, 2 temporomesial lesions, and 1 orbital/cavernous sinus abscess. Postoperatively, 2 patients had transient hemiparesis, 2 patients had transient third nerve palsy, and 1 patient had minimal visual field deterioration. All patients had a modified Rankin Scale score ≤1 at 8-week follow-up. The extended LSO approach opens a new route (frontopterio-orbital window) to perform extradural anterior clinoidectomy safely and increases surgical exposure, angles, and operability of a less invasive keyhole craniotomy (LSO approach) to treat anterior cranial fossa lesions.

The modified lateral supraorbital approach for tumors of the petroclival junction extending into the anterior cerebellopontine area.

Various surgical approaches for the removal of meningioma and trigeminal schwannoma in the petroclival junction (PCJ) and anterior cerebellopontine area (CPA) have been described previously. In this study, we compared the surgical outcomes of the combined petrosal approach and a modified lateral supraorbital (MLSO) approach and evaluated the reliability and safety of the MLSO approach. Fifty patients underwent surgical treatment using the combined petrosal or MLSO approach between 1996 and 2011. We retrospectively analyzed the clinical data and compared the two approaches. Among 50 patients, 27 patients underwent operation through the combined petrosal approach and 23 underwent operation through the MLSO approach. The operation time of the MLSO approach was significantly shorter than that of the combined petrosal approach (p = 0.03). There was no significant difference in the gross total resection rate between the two approaches (p = 0.67). After the operation, the improvement in Karnofsky performance score and Mean Glasgow outcomes scales were better in the MLSO approach, but without statistical significance (p = 0.723, p = 0.20 respectively). Complications occurred more often with the combined petrosal approach than with MLSO. Facial nerve palsy was the most common complication, followed by hearing difficulty. The frequency of these two complications was higher in the combined petrosal approach. Various tumors occurring in the PCJ and anterior CPA remain a challenging problem for neurosurgeons. The new modified approach of MLSO yielded good surgical results for these tumors compared to the combined petrosal approach. Therefore, the MLSO approach might be a good option for removal of tumors in the PCJ including anterior CPA.Electronic supplementary materialThe online version of this article (doi:10.1007/s11060-016-2061-9) contains supplementary material, which is available to authorized users.

Clinical analysis of resecting anterior cranial fossa meningiomas via lateral supraorbital approach

Objective To investigate the advantages and significance of the lateral supraorbital approach in the surgical treatment of anterior cranial fossa meningiomas. Methods From June 2011 to June 2014, the clinical data of 47 patients resected anterior cranial fossa meningiomas via lateral supraorbital approach at the Department of Neurosurgery, Qilu Hospital of Shandong University were analyzed retrospectively. According to the radiological findings and the symptoms improvement of the nervous system, the reliability of the surgery program before treatment in anterior cranial fossa meningiomas was evaluated. Results Forty-five patients had Simpson Ⅰ grade resection and 2 had Simpson Ⅱ grade resection. The pathology showed 46 patients with meningiomas WHO grade Ⅰ and 1 with meningioma WHO grade Ⅱ (atypical meningioma). Four patients had fever after procedure, 5 had hyponatremia, 9 had psychiatric symptoms, 1 had cerebral edema, and 7 had seizures. No incision infection and cerebrospinal fluid rhinorrhea occurred, and none of the patients died. They were followed up for 3 to 36 months after procedure. Imaging examination revealed no recurrence. Conclusion The treatment of anterior cranial fossa meningiomas via lateral supraorbital approach has the advantages of complete resection of tumors, less trauma, and fewer complications. Key words: Lateral supraorbital approach; Anterior cranial fossa meningiomas; Microneurosurgery

The orbitozygomatic stich: A technical modification of the lateral supraorbital approach.

Background:The lateral supraorbital approach (LSO) provides access to a variety of pathologies including anterior and some posterior circulation aneurysms, sellar and suprasellar lesions, and anterior fossa tumors. Technical modifications of LSO improve the surgical exposure of the skull base.Methods:We retrospectively analyzed 73 consecutive patients treated by the senior author (Juha A. Hernesniemi), at the Department of Neurosurgery, Helsinki University Hospital in Helsinki, Finland from May 2013 to October 2013. This study cohort underwent a modified LSO to access anterior circulation aneurysms, sellar and suprasellar tumors, and anterior fossa tumors. The studied population comprised 30 men and 43 women, with a mean age at treatment of 54 years (9–83 years).Results:LSO was successfully used to access anterior circulation aneurysms in 59 (81%) patients, 10 (14%) patients with anterior cranial fossa tumors, and 4 (5%) patients with suprasellar tumors. The skull base drilling provided a mean of 6.8 mm (1.7–22 mm) in increased exposure.Conclusion:LSO provides adequate access to vascular and neoplastic lesions of the anterior cranial fossa, by drilling approximately 6.8 mm (1.7–22 mm) of the lateral orbital wall and sphenoid wing. This enhances surgical exposure and trajectory. An additional trick while performing an LSO is to place a single or multiple stiches (orbitozygomatic stich) at the base of the dura once opened, eliminating the dead space between the dura and anterior skull base.

Surgical treatment of anterior circulation aneurysms via lateral supraorbital approach

To evaluate the efficacy of the surgery with lateral supraorbital approach for clipping anterior circulation aneurysms. The clinical data of 99 patients with anterior circulation aneurysms who underwent a clipping via lateral supraorbital approach from October 2012 to September 2014 and 75 patients, who underwent a clipping via pterional approach from January 2010 to December 2011 in the second Affiliated Hospital, Zhejiang University School of Medicine were reviewed. The operative duration, prognosis, residual rate and rupture rate during surgery were compared between two groups. The patients by lateral supraorbital approach had a shorter operative duration, namely 37~61 min less than that in the patients by pterional approach. No difference were found in residual rate and rupture rate between two groups. The Glasgow Outcome Scale (GOS) at 3 months after surgery showed no significant difference between two groups. The lateral supraorbital approach can be used safely and effectively with shorter operative duration and less tissue damage for treatment of patients with anterior circulation aneurysms.

Validity of the Lateral Supraorbital Approach as a Minimally Invasive Corridor for Orbital Lesions

Many approaches were recommended for surgical treatment of orbital lesions via either transorbital or transcranial routes. The frontolateral craniotomy through eyebrow skin incision (lateral supraorbital approach) is a combined cranio-orbital approach that could be used in different orbital lesions. To evaluate the efficacy and safety of the lateral supraorbital approach for resection of orbital lesions. Ten patients with different orbital lesions were treated by this minimally invasive technique. The technique is described in details. The postoperative outcome was evaluated with casting light on the specific parameters related to this approach. This study included 6 females and 4 males, ranging in age from 2 years to 65 years with mean age of 37.3 years. Proptosis was the most common presenting complaint. Six patients were operated on via the right supraorbital approach, and 4 patients via the left supraorbital approach. Various pathological lesions were treated. The excision was total in 7 patients, subtotal in 1 patient, and partial in 2 patients. Two patients suffered transient supraorbital hypothesia, 1 patient showed temporary superficial wound infection with CSF leak and 1 patient died within 6 months. The lateral supraorbital approach is a minimally invasive approach that provides excellent exposure of the superior, lateral, and medial orbit, as well as the orbital apex.

The extended transorbital craniotomy: an anatomic study.

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. 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. 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). 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. 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.

Keyhole concept in cerebral aneurysm clipping and tumor removal by the supraciliary lateral supraorbital approach.

The keyhole concept in neurosurgery is designed to minimize the craniotomy needed for the access route to deep intracranial pathologies. Such keyhole surgeries cause less trauma and can be less invasive than conventional surgical techniques. Among the various types of keyhole mini-craniotomy, supraorbital or lateral supraorbital mini-craniotomy is the standard and basic keyhole approaches. The lateral supraorbital keyhole provides adequate working space in the suprasellar to parasellar areas and planum sphenoidale area including the anterior communicating artery complex. Despite the development of neuro-endoscopic techniques and intra-operative assistant methods, the limited working angle to manipulate and observe deeply situated pathologies is a major disadvantage of the keyhole approaches. Neurosurgeons should understand that keyhole mini-craniotomy surgeries aim at “minimally invasive neurosurgery” but still carry the risks of malpractice unless we understand the advantages and disadvantages of these keyhole concepts and strategies.

“Extra-Dural Anterior Clinoidectomy through the Lateral Supraorbital Approach: Surgical Anatomy and Initial Clinical Experience”

“Extra-Dural Anterior Clinoidectomy through the Lateral Supraorbital Approach: Surgical Anatomy and Initial Clinical Experience”

Lateral supraorbital approach applied to sellar tumors in 23 consecutive patients: the Suzhou experience from China.

BackgroundPituitary adenoma, craniopharyngioma and meningioma are common sellar lesions, accounting for more than 90% of sellar tumors. The aim of this study is to assess the reliability and safety of the lateral supraorbital (LSO) approach to remove sellar tumors.MethodsBetween June 2011 and December 2011, 23 patients with neoplastic lesions underwent surgery by the corresponding author (ZW) via the LSO approach. The clinical presentations, neuroradiological findings, microsurgical techniques, and outcome at discharge of these patients were analyzed. In addition, the clinical series in the available literature written in English were also extensively reviewed. Eleven (48%) patients were treated for pituitary adenoma; six (26%) patients for tuberculum sellae meningioma; and six (26%) patients for craniopharyngioma.ResultsSeemingly complete tumor removal was achieved in 21 patients (91%); surgical mortality was one patient (4.3%). Postoperatively, no patient had developed cerebrospinal fluid leakage or new visual deficits. One (4%) patient had intracranial infection, and one (4%) had a postoperative hematoma. The median Karnofsky score at discharge was 87.4 (range, 0 to 100). The Glasgow outcome scale at discharge was 4.6 (range, 1 to 5). Of all, 21 (91.3%) patients achieved favorable outcomes.ConclusionSellar tumors can be removed via the LSO approach with relatively low morbidity and mortality. Surgical results with this fast and simple approach are similar to those obtained with more extensive, complex, and time-consuming approaches.

Unilateral subfrontal approach to anterior communicating artery aneurysms: A review of 28 patients

Dear Editor, The authors present the named “unilateral subfrontal approach” for anterior communicating aneurysms, analyzed in a small clinical series. The authors present this approach mainly as an alternative to the pterional approach. This approach was previous described as the “superciliar keyhole approach” or the “lateral supraorbital approach” for the treatment not only of vascular disease but also for tumors.[2] The authors present their approach as a “tailored” pterional approach. Nevertheless, there are some aspects that are subject of criticism as the rutinary use of external ventriculostomy or lumbar drainage; these are procedures that carry additional risks: Intraoperative rebleeding, frontal lobe lesion among others. We strongly recommend the microsurgical wide opening of the basal cisterns and the fenestration of the lamina terminalis to obtain CSF drainage and brain relaxation during the surgery, we do not see the silvian fissure opening as an additional source of complications as the authors pointed out. Additionally, these microsurgical simple procedures are implicated in the prevention of the hydrocephalus and vasospasm in the subarachnoid hemorrhage secondary to ruptured aneurysms.[1] The four advantages that the authors provided are at least uncertain. In the number 4 we can say that the pterional approach provide a corridor to see up to the contralateral middle cerebral artery bifurcation. Another important issue is that they have a 50% of resection of the gyrus rectus in unruptured and 61% in ruptured aneurysms, so the approach does not avoid this designed resection of the frontal lobe; we only use a small gyrus rectus resection in the anterior communicating artery (ACoA) aneurysms superiorly projected located between the two A2 segments, especially in the large or giant lesions, in all the other cases we split the interhemispheric cistern, which is possible using the pterional approach. The authors point out that the pterional approach leave a cosmetic defect at the level of the pterion, but in their own series the leave two burr holes in the frontal bone visible in the forehead. Salma et al.[3] recently published a cadaveric anatomical study comparing this two approaches, in their paper they analyzes the qualitative and quantitative anatomic evaluation between this two approaches, showing that this kind of approach can eventually reduce the temporalis muscle trauma, and offers and equivalent access and exposure of the anterior communicating artery complex, optic nerve, optic chiasm, and sellar areas. However, like all the anatomical cadaveric models, they do not consider the role of the cisternal and ventricular opening using these anatomical corridors as the natural pathways to reach the pathology, in this case ACoA aneurysms. We think that in patient's ruptured aneurysms with hematoma or subarachnoid hemorrhage (SAH) of high Fisher grade this approach is not a good choice, because it does not allow a wide opening of the sylvian fissure for cleansing the blood clots and relaxing the brain. Hence, this approach would be useful just for treating the aneurysm, but not to deal with the SAH, without reducing neither the risk of vasospasm nor the hydrocephalus.

Microscopic and endoscopic anterior communicating artery complex anatomy as seen through keyhole approaches

The purpose of this anatomical study is to illustrate the microscopic and endoscopic anatomy of the anterior communicating artery complex as viewed through three keyhole approaches (keyhole pterional, lateral supraorbital and supraorbital) and to compare them. Each approach was carried out once on each side in five glutaraldehyde-fixed human cadaveric heads. A microscope and microscope–endoscope combination were used to grade access and visualization of the structures qualitatively using a previously published surgical exposure grading system. All three approaches provided good access and visualization of ipsilateral structures in the anterior communicating artery complex, but the pterional keyhole and the lateral supraorbital approaches gave the best access. Exposure of contralateral structures was limited overall, but was enhanced somewhat by the use of the endoscope.