The trans-supraorbital approach.

The trans-supraorbital approach represents the advantage of combining the keyhole principle and skull base surgery. In cadaveric work the author shows the anatomic fields visualized with this procedure, advantages and potential surgical applications. The experimental surgical procedure was performed on 8 adult skulls and on 3 cadavers with intact cerebral structures. First, a 2 cm supraorbital approach for endoscopic exploration was used. The basic anatomic landmarks and corresponding dimensions of the microsurgical field were recorded and then compared with those from the trans-supraorbital approach, after removing the orbital arch and other parts of the orbital ceiling. This technique offers a 0.5 cm average increase in surgical field from the craniotomy. The surgical distance that results is shorter (about 2 cm), as well as the length of the surgical instruments required. A better microscope illumination in the deep fields, and the possibility of access to the intraorbital region, the superior orbital fissure, the optic foramen, and the cavernous sinus through the clinoid space are also obtained, with minimal cerebral retraction and similar advantages as through the pterional trans-sylvian approach. The author concludes that by extending the craniotomy and decreasing the surgical distance, the microsurgical field is more convenient for microscope-assisted surgery without totally relying on the endoscope, and with minimal brain retraction. It also provides multiple options to approach vascular and tumor lesions found in these microsurgical corridors, combining principles of minimal invasion and skull-base surgery.     

The keyhole concept in aneurysm surgery--a comparative study: keyhole versus standard craniotomy.

OBJECTIVE: The purpose of the study is to compare the results of minimally invasive keyhole craniotomy and standard larger craniotomies in the surgical treatment of patients with intracranial aneurysms. METHODS: In the past eight years 628 patients were operated by two experienced neurosurgical teams. The first group of 482 patients with 565 aneurysms were operated through a small keyhole craniotomy, using the eyebrow keyhole approach in particular. The remaining 146 patients with 167 aneurysms were operated using a standard craniotomy that included pterional/frontotemporal, frontoparietal parasagittal, and retrosigmoid suboccipital craniotomies. All operations were performed in the standard microsurgical technique using intraoperative evoked potential monitoring and endoscopic assistance in selected cases. RESULTS: Most supratentorial aneurysms and basilar tip aneurysms were successfully operated through an eyebrow keyhole craniotomy. Distal MCA aneurysms as well as aneurysms on the MCA with a long M1 segment were operated through a temporal keyhole, and aneurysms of the distal PCA (P2-P3) segment subtemporally. The frontoparietal parasagittal keyhole approach was used only for pericallosal artery aneurysms. Infratentorial aneurysms of the VA/PICA complex were operated via a retrosigmoid approach. On comparing the surgery results in patients with a keyhole craniotomy and those with standard craniotomy, similar outcomes were found for both groups, with excellent or very good outcomes (GOS 5 and 4) in 398 (82.57%) patients from the keyhole craniotomy group, and in 116 (79.45%) patients from the standard craniotomy group. The mortality rate in the keyhole group was 0.83% (4 patients) and 2.05% (3 patients) in the standard craniotomy group. CONCLUSION: Parallel treatment results in using two options--keyhole craniotomy and standard larger craniotomy--were analysed in the past eight years. Two experienced neurosurgical teams in performing both surgical approaches have reached almost similar morbidity and mortality rates, and overall surgical results. The type of craniotomy is selected according to the experience of the surgical team, and familiarity with certain approach. The authors have good experience with the minimally invasive approach for different intracranial pathology and recommend it especially in neurovascular surgery.     

A temporal transsylvian approach to anterior circulation aneurysms.

Operative management of cerebral aneurysms remains a technically challenging problem in modern neurosurgery despite major advances in microsurgical techniques. This is largely caused by the difficulty of exposing and handling these aneurysms, which are located around the circle of Willis at the base of the brain. Large cranial windows, generous brain retraction, and local brain resection have, at times, been employed to overcome these difficulties. In the present report, an exclusively temporal approach to the anterior aspect of the circle of Willis for surgical treatment of aneurysms arising from the anterior circulation is described. This approach limits the surgical preparation and the craniotomy to the temporal area, protects the temporal branch of the facial nerve from injury, and provides a superior cosmetic appearance soon after surgery. It provides a lateral transsylvian exposure to the base of the brain and thus permits the safe dissection and exposure of the aneurysms using microsurgical techniques with minimal, if any, retraction of the frontal lobe. The need for routine resection of the gyrus rectus for exposure of anterior communicating artery aneurysms is alleviated. This approach can be considered in patients harboring large or small incidental or acutely ruptured anterior circulation aneurysms. The outcome of 96 consecutive patients who underwent this procedure is described to illustrate its safety and effectiveness.     

Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation. Technical note

A modification of the supraorbital keyhole approach, the eyebrow incision-minisupraorbital craniotomy with orbital osteotomy, is described. Unique to this approach is a one-piece supraorbital craniotomy, measuring 2.5 x 3.5 cm, that incorporates the orbital rim and roof and the frontal process of the zygomatic bone through an eyebrow incision. The orbital osteotomy facilitates view of the anterior and middle cranial fossa through the operating microscope, as well as the maneuverability of instruments through a small craniotomy. A pericranial flap is elevated with its base at the orbit and used for closure of the frontal sinus, if necessary. The approach was used successfully in elective surgery of 10 aneurysms of the anterior circulation. The mean aneurysm size was 5.9 mm, with a range of 4 to 10 mm. Advantages of this approach include minimal disruption and exposure of normal brain tissue, reduced frontal lobe retraction, and an excellent postoperative cosmetic result. The approach is performed quickly by virtue of a limited skin incision with minimal temporalis muscle dissection and a small bone flap. The neuroendoscope, although helpful at times, is not essential and no special instruments or intraoperative image guidance is required. Relative contraindications include the presence of a large frontal sinus, severe brain edema, and recent subarachnoid hemorrhage. In addition, this approach has not been used for the treatment of giant intracranial aneurysms.     

眶上锁孔入路显微手术治疗前循环动脉瘤

目的 探讨眶上锁孔人路、神经内镜辅助显微手术治疗前循环动脉瘤的手术方法。方法 对12例前循环动脉瘤患者,依据手术前诊断性影像资料,制订个体化手术计划;手术行眉部皮肤切口,于眶上作直径2cm左右骨窗开颅,采用内镜辅助的显微外科技术夹闭动脉瘤。结果 12例5种不同类型动脉瘤患者经该方法治愈,其中1例患者术中动脉瘤破裂,经阻断载瘤动脉12min,妥善分离动脉瘤后,在内镜辅助下准确夹闭瘤颈,术后对侧肢体有暂时性轻瘫,经治疗1周后肌力恢复正常。本组病例均未出现与手术人路相关的并发症。结论 采用眶上锁孔入路、内镜辅助的显微外科技术治疗前循环动脉瘤,是一种安全、微侵袭和有效的途径。     

Surgical experience with frontolateral keyhole craniotomy through a superciliary skin incision

OBJECTIVE: The purpose of this study was to evaluate the results of 173 frontolateral keyhole minicraniotomies performed on 155 patients with aneurysms of the anterior or posterior cerebral circulation and for supratentorial tumors. METHODS: The frontolateral keyhole craniotomy is a modification of the generally used pterional approach. Of the 155 patients studied, 102 harbored saccular arterial aneurysms in the vessels of the anterior or posterior cerebral circulation, and 53 had various tumors in the frontal base, suprasellar, or parasellar region. The operations were carried out through an approximately 2.5- x 3-cm frontolateral miniaturized craniotomy after a skin incision just above the eyebrow. RESULTS: Despite the small size of the craniotomy, the exploration allows enough room for intracranial manipulation with maximal protection of the brain and other intracranial structures. The presented series of patients did not have any craniotomy-related complications. CONCLUSION: In our experience, the frontolateral keyhole craniotomy, together with the advent of the modern neuroanesthesia, cerebrospinal fluid drainage, and microsurgical techniques, is a safe approach for an experienced neurosurgeon to use in the treatment of supratentorial aneurysms or tumors of the anterior fossa and sellar regions.     

Orbitocraniobasal approach for anterior communicating artery aneurysms

We describe an orbitofrontotemporobasal craniotomy technique that allows excellent access to anterior communicating artery aneurysms. This orbitocraniobasal approach is particularly useful for the surgical treatment of ruptured aneurysms in the acute stage of subarachnoid hemorrhage, when retraction of the brain needs to be kept to a minimum. With this approach, retraction of the orbital contents decreases the amount of retraction of the brain to such an extent that a brain spatula is not necessary for access to the anterior communicating artery complex. The procedure is described, as is a modification of the approach for removal of large tumors on the skull base.     

Pterional craniotomy without keyhole to supratentorial cerebral aneurysms: technical note

BACKGROUND: Patients who have pterional craniotomy occasionally complain of scalp deformity at the frontotemporal area because of craniotomy site. Especially, this occurs as a result of inappropriate repair of the bony defect at the keyhole with the complex curvature of the surrounding bone, although burr holes buttons are used. The author presents results of pterional craniotomy that is performed without keyhole to supratentorial cerebral aneurysms. METHODS: The temporal muscle was incised a few millimeters before its insertion at the superior temporal line, leaving a small fascial cuff for anatomic reattachment during closure. Only one burr hole was placed on the superior temporal line 3 to 4 cm posteriorly from the frontal base. After clipping of aneurysm, the bone flap was fixed using a titanium clamp (CranioFix) for a burr hole and 2 miniplates. RESULTS: Postoperative three-dimensional computerized tomography scans and photographs reveal excellent cosmetic results with the smooth cranial surface without scalp deformity at 6-month follow-up. Dural laceration developed in two cases, but there was no cerebral spinal fluid leakage after repair. CONCLUSION: Our technique offers good cosmetic results and less risk of disaster by intraoperative rupture of aneurysm than the keyhole surgery.     

Efficacy and safety of the pterional keyhole approach for the treatment of anterior circulation aneurysms

Keyhole surgery is partly replacing the standard pterional approach in patients undergoing surgery to treat aneurysms of the anterior circulation. We describe the pterional keyhole approach for the clipping of anterior circulation aneurysms and discuss the efficacy and safety of our keyhole craniotomy procedure. We treated 103 patients with 111 intracranial aneurysms by surgical clipping via the pterional keyhole approach and retrospectively compared the characteristics and clinical outcomes of the keyhole procedure and the standard pterional approach. We also compared the surgical results of the keyhole approach when the operator was an experienced neurosurgeon or a less experienced neurosurgeon guided by an experienced colleague. All keyhole operations were carried out successfully without enlargement of the craniotomy or a change to a different approach. The outcomes of the keyhole and the standard pterional approach in patients with subarachnoid hemorrhage were not significantly different. Favorable outcomes were obtained in patients with unruptured aneurysms treated by either experienced or less experienced surgeons. The pterional keyhole approach offers the same surgical possibilities as conventional pterional approaches for the treatment of anterior circulation aneurysms. It is safe and simple and yields favorable outcomes even if the operators are less experienced neurosurgeons. Careful patient selection and sufficient opening of the sylvian fissure are the key points for good outcomes and the prevention of intraoperative complications.     

Bilateral supraorbital keyhole approach for multiple aneurysms via superciliary skin incisions

BACKGROUND: Considering that multiple aneurysms carry a high risk for fatal rupture, there is a need for complete treatment of all lesions in one surgical session using either unilateral-contralateral or bilateral approaches. Contralateral approaches have been used mainly for small anteriorly projecting middle cerebral and medially expanding ophthalmic types of aneurysms. They are limited by the narrow space for surgical manipulation, forced elevation of frontal lobes, and stretching of the olfactory nerves. These problems might result in damage to structures along the unusually long intracranial way of the approach. The complications associated with the unnecessarily large conventional fronto-temporal and bifrontal craniotomies, and the developments in visualization, neuroanaesthesia, microneurosurgery, cerebrospinal fluid (CSF) drainage, and brain protection have led to less invasive methods in cerebral base surgery. These achievements have supplied the background for the supraorbital keyhole approach to aneurysms of the anterior circulation or basilar tip. Because the supraorbital keyhole approach offers several advantages over the classic fronto-temporal craniotomies to the anterior skull base, it was extended for both sides in one surgical session to treat bilateral multiple aneurysms as well. METHODS: Out of a series of 150 patients harboring 188 saccular aneurysms operated on via a supraorbital keyhole approach with a superciliar skin incision, 36 had multiple aneurysms. Thirty patients with multiple aneurysms underwent surgery for their ruptured aneurysms (17 cases in the acute phase and 13 patients during the chronic stage); in 6 cases silent aneurysms were operated on. The multiple aneurysms were managed from one side in 18 cases. A bilateral supraorbital keyhole approach was performed during one surgical session in 11 patients, and in 7 cases the unilateral supraorbital keyhole approach was combined with contralateral fronto-temporal (3 cases), suboccipital (2 cases), or frontal-parasagittal (2 cases) exploration. The operations were carried out through an approximately 2.5 x 3 cm supraorbital keyhole craniotomy following a skin incision just above the eyebrow. The roughly 4 cm superciliar skin incision begins medial to the supraorbital nerve and ends 3 to 10 mm beyond the lateral edge of the eyebrow. The technical details of the method are presented, and the benefits, limitations, and complications are discussed. RESULTS: In the 36 patients operated on via the supraorbital keyhole approach 74 aneurysms were clipped successfully. In 2 cases premature intraoperative rupture of the aneurysms occurred, but these events were managed successfully. Despite the small size of the craniotomy the approach allows enough room for intracranial manipulation with maximal protection of the brain and other intracranial structures. One patient died because of pulmonary embolism. There were no craniotomy-related complications in the present series. CONCLUSION: The supraorbital keyhole approach together with the advent of the modern neuroanaesthesia, CSF drainage, and microsurgical techniques is a safe approach in the hands of experienced neurosurgeons for the treatment of supratentorial or basilar tip aneurysms. Because the approach is simple and swift, the bilateral single-session craniotomy does not have any disadvantages compared to two-stage procedures. However, the one-sitting surgery reduces the high risk of fatal rupture in the perioperative period associated with multiple aneurysms.     

A pterion keyhole approach for the treatment of anterior circulation aneurysms.

The supraorbital keyhole approach is most frequently used in treatment for lesions within the anterior cranial base. However, it has some drawbacks, including cosmetically poor appearance of the scar, forehead deformity, and difficulty in dealing with some kinds of middle cerebral artery (MCA) and internal carotid artery (ICA) aneurysms. Therefore, we have developed a small pterion keyhole approach for an alternative access to treat anterior circulation aneurysms. An oblique skin incision about 3-5 cm in length was made just from 1.0 cm anterior to the superficial temporal artery at the level of the zygomatic arch, curved just below the temporal line to the forehead, and stopped at the hairline over the sylvian fissure. Then a small craniotomy (2-3 cm) was made just over the sylvian fissure and the aneurysms were exposed through the lateral cerebral fissure. We used this approach to treat 40 patients with aneurysms located in posterior communicating arteries (n=14), the MCA (n=10), the anterior communicating arteries (n=9), the anterior cerebral artery (n=1), the ophthalmic arteries (n=3), and the ICA (n=3). The general outcome of all patients was good without serious complications from the surgical technique even though 3 cases underwent intraoperative premature rupture of the aneurysms. No approach-related complication occurred except that one patient had vasospasm 2 days after the aneurysm clipping. In conclusion, this pterion keyhole approach can achieve the best operative effect for the treatment of intracranial anterior circulation aneurysms in a selective group of patients with several advantages over traditional craniotomy including minor tissue damage, less brain retraction, a superior cosmetic result, and shorter duration of surgery. Moreover, the operative field becomes wider in the deep area, providing sufficient space for microscope-assisted surgery without the need for highly specialized instruments.     

The One-Piece Orbitozygomatic Approach: The MacCarty Burr Hole and the Inferior Orbital Fissure as Keys to Technique and Application

Summary  Objective. Use of the MacCarty keyhole burr hole and the inferior orbital fissure provides simplicity and safety to perform the one-piece frontotemporal orbitozygomatic (FTOZ1) approach.  Methods. We performed the FTOZ1 approach with its three subtypes (i.e., total, temporal, and frontal) in cadaveric head specimens in the Goodyear Laboratory and subsequently in surgical cases.  Results. The orbitozygomatic osteotomy, when added to a frontotemporal craniotomy, comprises the frontotemporal orbitozygomatic (FTOZ) approach, provides an expanded exposure to the anterior and middle cranial fossae, and enables the surgeon to create a window to the posterior cranial fossa. The MacCarty burr hole is used to facilitate orbital cuts, and the anterolateral portion of the inferior orbital fissure connects the orbital cuts to the zygomatic cuts. This allows the FTOZ1 craniotomy flap to be “out-fractured” with ease. The three types of FTOZ1 approach, i.e., the total, the temporal, and the frontal, are described step by step.  Conclusions. Understanding the MacCarty keyhole burr hole and the microsurgical anatomy of the inferior orbital fissure is essential to performing the FTOZ1 approach. The three types of FTOZ1 approach enable the surgeon to tailor the approach according to the surgical exposure needed for each lesion.     

Eyelid approach to the anterior cranial base

Skull base approaches play a fundamental role in modern neurosurgery by reducing surgical morbidity. Increasing experience has allowed surgeons to perform minimally invasive approaches without straying from the premises of skull base surgery. The eyelid approach has evolved from the orbitopterional osteotomy into a more effective and targeted approach to disease of the anterior cranial fossa. In this technique, after an incision is made on the supratarsal fold, the orbicularis oculi muscle is incised, and a myocutaneous flap composed of the elements of the anterior lamella is elevated. Subperiosteal dissection is used to expose the superior and lateral walls of the orbit, the superior and lateral orbital rim, and the frontosphenoidal suture. A MacCarty bur hole is drilled, and a frontal osteotomy is fashioned medial to the supraorbital notch and extending through the orbital roof back toward the orbital half of the MacCarty bur hole, exposing the frontobasal brain. A conventional microsurgical technique is used to treat tumors and aneurysms of the anterior cranial fossa under the operative microscope. Five patients were treated for unruptured aneurysms of the anterior circulation (3 anterior communicating artery aneurysms, 1 ophthalmic artery aneurysm, and 1 posterior communicating artery aneurysm) using the eyelid approach. The mean aneurysm size was 5 mm, and all aneurysms were approached from the right side. Three tumors in the anterior fossa (2 suprasellar pituitary adenomas and 1 craniopharyngioma) were also excised using this approach. There was no surgical morbidity. Three months after surgery all patients presented excellent cosmetic results. The eyelid approach may be considered as an effective, cosmetically beneficial, and minimally invasive skull base approach to selected aneurysms and tumors of the anterior circulation.     

锁孔微创入路手术治疗颅内动脉瘤的风险因素及对策分析

目的 探讨颅内动脉瘤在锁孔手术中破裂的风险因素、适应证选择、手术难点、预防动脉瘤破裂的方法及应急处理措施.方法 回顾性分析1999年至2005年115例动脉瘤患者的临床资料.将动脉瘤破裂风险较低的43例患者通过锁孔微创入路手术治疗（锁孔组）,其余72例患者采用常规开颅手术治疗（常规组）.锁孔组43例患者手术中翼点锁孔入路20例,眶上锁孔入路18例,纵裂锁孔入路5例.常规组72例患者风险高而采用常规翼点开颅31例,额下开颅11例,纵裂开颅7例,翼点-额下联合10例,翼点-纵裂联合6例,额下-纵裂联合4例,翼点-额下-纵裂联合3例.结果 锁孔组术中动脉瘤渗漏6例,破裂出血3例,发生率为7%,无手术死亡.2例在锁孔手术中无法夹闭动脉瘤而改为常规开颅.常规组术中发生动脉瘤渗漏18例,破裂出血9例,发生率为13%,手术后死亡2例.结论 尽管锁孔手术有微创、伤口美观、术后恢复快等优点,但在风险低的患者中动脉瘤渗漏和破裂的风险仍然不能忽视.     

Management of anesthesia in awake craniotomy

The awake craniotomy technique was originally introduced for the surgical treatment of epilepsy and has subsequently been used in patients undergoing surgical management of supratentorial tumors, arteriovenous malformation, deep brain stimulation, and mycotic aneurysms near critical brain regions. This surgical approach aims to maximize lesion resection while sparing important areas of the brain (motor, somatosensory, and language areas). Awake craniotomy offers great advantages with respect to patient outcome. In this type of procedure, the anesthetist's goal is to make the operation safe and effective and reduce the psychophysical distress of the patient. Many authors have described different anesthetic care protocols for awake craniotomy based on monitored or general anesthesia; however, there is still no consensus as to the best anesthetic technique. The most commonly used drugs for awake craniotomies are propofol and remifentanil, but dexmedetomidine is beginning to be used more commonly outside of Europe. Personal experience, careful planning, and attention to detail are the basis for obtaining good awake craniotomy RESULTS: Additional studies are necessary in order to optimize the procedure, reduce complications, and improve patient tolerance. The aim of this review is to present a thorough report of the literature, with particular attention to neuro-oncology surgery.     

The endoscopic supraorbital approach to tumors of the middle cranial base

BACKGROUND: Access to tumors of the middle cranial base has traditionally required wide surgical exposures via open craniotomies. These open techniques often require the use of potentially disfiguring skin incisions and are often associated with a significant degree of brain retraction and potential morbidity. We report our experience with the use of a minimally invasive supraorbital endoscopic approach through the eyebrow for excision of middle cranial base tumors in 2 cases. METHODS: We describe 2 patients with large-sized middle cranial fossa tumors (a medial sphenoid wing meningioma measuring 6 x 4 cm and a recurrent right cavernous sinus meningioma measuring 4 x 3.5 cm) that were entirely removed via a fully endoscopic supraorbital approach using a 1.5-cm keyhole craniotomy. CONCLUSION: These cases demonstrate how the application of endoscopic techniques to surgery of the middle cranial base can eliminate the need for traditional open techniques without compromising surgical success.     

Simple anterior orbitotomy.

OBJECTIVE: Simple anterior orbitotomy is one of the popular surgical procedures through the orbital cavity. In this approach no bony orbitotomy is required so very satisfactory cosmetic results should be achieved. The authors of this paper report on three patients with space-occupying lesions in orbital cavity which were operated by anterior orbitotomy techniques without craniotomies. METHODS: Three patients with space-occupying lesions in the orbital cavity underwent a microsurgical procedure with simple anterior orbitotomy. RESULTS: No bony orbitotomy was used in this technique and the cosmetic results were very satisfactory. Although the surgical area is very narrow, no neurological deficit has appeared after this procedure using microsurgical operative procedures. CONCLUSION: Although the orbital cavity is very narrow, multiple neurological important structures occur in this area. Traction of the ocular bulb and optic nerve can be harmful for the patient. Therefore, many the surgeons prefer the transfrontal intracranial approach with superior orbital craniotomy for wide exposure. One of these three cases is a typical example for the simple anterior orbitotomy which is a useful operative approach for patients with solid space-occupying lesions in the superior part of the orbital cavity. Another patient with a hydatid cyst in orbital cavity was operated successfully via a simple anterior orbitotomy. The third patients was 6 years old and shows that the procedure can be used easily in children as well.     

Supraorbital craniotomy for parasellar lesions. Technical note

The authors present a modification to a previously reported supraorbital craniotomy procedure that is smaller, simpler, safe, and cosmetically pleasing. Minimal brain retraction is used without compromising the surgical exposure of the orbital roof, floor of the anterior fossa, and the parasellar region to treat tumoral lesions that are located medial to the ipsilateral optic nerve as well as aneurysms of the anterior communicating artery.     

Transorbital keyhole approach to anterior communicating artery aneurysms

OBJECTIVE: The transorbital keyhole approach to anterior communicating artery aneurysms was developed as a minimally invasive method for safe control of the anterior communicating artery complex. This approach does not necessitate resection of the gyrus rectus. METHODS: The technique is described in detail. The transorbital keyhole approach provides more ventral access than the supraorbital approaches, and the anterior communicating artery complex can be controlled by splitting the basal aspect of the interhemispheric fissure. RESULTS: Since late 1998, the authors have used the transorbital keyhole approach routinely. During the initial experience with 33 patients, the only observed complication specific to this approach was transient diplopia in one patient. At follow-up examinations 2 to 15 months after surgery, the cosmetic results were favorable as compared with those of standard pterional craniotomy. CONCLUSION: We have designed a small, custom-tailored approach to the anterior communicating artery complex for routine use. The small orbitocranial approach is a step toward the ideal of purely extra-axial safe control of anterior communicating artery aneurysms. The orbitocranial keyhole approach seems to be substantially better than the craniotomy, although it requires additional effort and time.