- Email: [email protected]
Supraorbital eyebrow minicraniotomy for anterior circulation aneurysms
Surgical Neurology 63 (2005) 47 – 51 www.surgicalneurology-online.com
Technique
Supraorbital eyebrow minicraniotomy for anterior circulation aneurysms Patrick Mitchell, FRCSa,*, R.R. Vindlacheruvu, FRCSa, Khalid Mahmood, FRCSb, Richard D. Ashpole, FRCSc, Athanasios Grivas, FRCSd, A. David Mendelow, FRCSa a
Department of Neurosurgery, Newcastle General Hospital, NE4 6BE Newcastle, UK b King Edward Medical College Lahore, Pakistan c Department of Neurosurgery, Queen’s Medical Centre, Nottingham, UK d Neurosurgery Department, Hellenic Air Force Hospital, Athens, Greece Received 8 December 2003; accepted 23 February 2004
Abstract
Background: We report our experience with the minimally invasive supraorbital approach to aneurysms of the ipsilateral anterior cerebral circulation. Methods: A prospective review of all patients who underwent operations to clip aneurysms in Newcastle between 1993 and 2002. Results: Fifty-six aneurysms were clipped via minicraniotomy in 47 patients. Six patients presented with acute subarachnoid hemorrhage (SAH), 40 patients were admitted for elective clipping, and 1 patient presented with an SAH, had the responsible aneurysm clipped and was readmitted later for elective clipping of a further aneurysm. Bilateral supraorbital craniotomies were performed in 3 patients. In 6 patients, multiple aneurysms were clipped via a single craniotomy. All aneurysms were well visualized with the microscope. Endoscopic assistance was not found necessary. All were successfully clipped. Two aneurysms ruptured while being clipped. There was no direct mortality from surgery. One patient died later from a separate posterior circulation aneurysm. One patient had a significant long-term deficit but remained independent, and 1 had 3 seizures over the 12 months after surgery. This represents a 4% morbidity at 1 year. Conclusion: Selected anterior cerebral circulation aneurysms can be clipped with low morbidity, using an ipsilateral minicraniotomy preserving the orbital rim, and without using an endoscope. The types of aneurysm selection criteria and operative equipment used are described. D 2005 Published by Elsevier Inc.
Keywords:
Minicraniotomy; Cerebral aneurysm
1. Introduction There has long been an impetus to move toward less invasive surgery, and the introduction of improved equipment often leads to significant gains in this area. The availability of high performance operating microscopes and endoscopes has allowed a dramatic reduction in the size of the skull opening required to gain neurosurgical access. The supraorbital eyebrow minicraniotomy is a product of this process. The approach with reliance on endoscopic visualization has been used successfully for a wide range of skull base pathologies, including tumors [9,14,16], and
* Corresponding author. E-mail address: [email protected] (P. Mitchell). 0090-3019/$ – see front matter D 2005 Published by Elsevier Inc. doi:10.1016/j.surneu.2004.02.030
vascular access [2,5,11-13,17]. We have applied the approach to the clipping of aneurysms and from the outset have selected only those cases where the aneurysms and proximal feeding vessels could be visualized directly with a microscope. 2. Patients and methods 2.1. Selection criteria Only aneurysms of the anterior circulation were considered. They were excluded if it appeared from the angiogram that the neck could not be visualized from the front without significant retraction on the aneurysm. Thus, small aneurysms and those projecting laterally or posteriorly were included. Aneurysms projecting anteriorly were assessed on
48
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
Table 1 Patient outcomes at last follow-up (n = 47)
3. Operative technique
Outcome (GOS [8] )
Elective
Acute SAH
All
Good recovery Epilepsy only Moderate disability Severe disability Vegetative Dead (later)
40 0 1 0 0 0
5 1 0 0 0 1a
44 (one had both) 1 1 0 0 1a
a
Died of a subarachnoid hemorrhage from a different aneurysm.
angiography. If the fundus was found to lie directly anterior to the neck and was large enough to obscure it when viewed from an anterior direction, the approach was not used. All anterior communicating complex aneurysms were excluded because of the difficulty in controlling the contralateral proximal vessels. No contralateral clipping was undertaken. Forty-seven patients with anterior circulation aneurysms were treated with the supraorbital craniotomy between February 1993 and October 2002 by the senior author (ADM) at the Department of Neurosurgery, Newcastle General Hospital. Data from these patients were collected prospectively. Clinical presentation was recorded including World Federation of Neurosurgical Societies grading in patients presenting with subarachnoid hemorrhage (SAH). Aneurysm location and size, intraoperative and postoperative complications, and outcome were also recorded. Patients’ ages ranged from 29 to 72 years with mean of 51. There were 33 females and 14 males. Seven patients were admitted as bemergencies Q after SAH, 5 were in World Federation of Neurosurgical Societies grade 1, and 2 were in grade 2. Forty patients were admitted electively for clipping of aneurysms. Of these, 1 had suffered a confirmed SAH 7 years previously, and 2 others had suffered headaches compatible with SAH 3 and 4 years previously, but SAH had not been confirmed. The remaining 37 patients had unruptured aneurysms clipped. In addition to these, one patient fell into both emergency and elective groups, was admitted with an SAH, and found to have multiple aneurysms. The ruptured one was clipped acutely, and the patient was readmitted after 2 weeks for clipping of the remaining aneurysms. Of the 41 patients with aneurysms that had not ruptured acutely, 12 had a history of a previous SAH and operative treatment of another aneurysm, 4 had a strong family history of SAH, and 1 had polycystic kidney disease. The remaining 24 patients had aneurysms found on investigation of other conditions. Eight of these were for headaches not thought to be related to the aneurysms found, 7 were for transient ischemic attacks, 2 for multiple sclerosis, 2 for dizziness, 1 for trigeminal neuralgia, 1 for tinnitus, 1 for a cerebellar hematoma, and 1 after an intraventricular hemorrhage. Neither of the 2 hemorrhages was contiguous with the aneurysms found. The outcome at the last available follow-up was assessed according to the Glasgow Outcome Scale (GOS) [8] (Table 1).
The technique used was substantially similar to that used by van Lindert et al [17], except that no reliance was placed on endoscopy, and the clip applicator was a bMizuhoikaQ type (Aesculap). A lumbar drain was used in all cases. A Budde Halo retractor system was used in all cases. The patient was positioned supine with the neck extended and turned about 208 to the contralateral side. This allowed the subfrontal subdural space to open as the frontal lobe fell superiorly under gravity. The upper half of the eyebrow was shaved. The skin incision extended laterally from immediately lateral to the supraorbital notch to about 2 cm lateral to the superior temporal line (Fig. 1). The incision was placed in a skin crease or where it would later be hidden by the eyebrow. The temporalis fascia and muscle were incised in the line of the skin incision. The limited muscle incision appears to avoid postoperative pain on mastication. A mini– burr hole was made behind the superior temporal line just above the zygomatic process of the frontal bone. Occasionally, the orbit was inadvertently entered, but this led to no long-term ill effects. A free bone flap was turned using a fine craniotome (Fig. 2). The width of the craniotomy was approximately 3 cm (2.5 cm anteriorly and 1 cm toward sphenoid wing) and the height measured 1.5 to 2 cm. Inspection of the pre operative computed tomography (CT) scan allowed the craniotomy to be optimally placed to allow access to the particular aneurysm while avoiding the frontal
Fig. 1. The position of the skin incision in this case is in the left eyebrow.
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
49
Fig. 4. View of the middle cerebral artery complex once the sylvian fissure is opened in an approach to a middle cerebral aneurysm. If a posterior communicating artery aneurysm is being approached, the fissure is opened at its medial end rather than in the middle as shown here.
Fig. 2. The location, size, and shape of the craniotomy.
sinus. The approach was not used in cases where the frontal sinus was large enough to inevitably be involved in the craniotomy. Early in the series, we used endoscopes to assess their utility in the approach. Straight ahead, 308 and 708 rigid endoscopes as well as flexible endoscopes were tried. For middle cerebral artery aneurysms, the frontal lobe was retracted upward (Fig. 3). The lesser wing of the sphenoid was not removed. The sylvian fissure was entered in its middle portion and was split along a length of around 2.5 cm. In general, it was not split to its medial limit (Fig. 4).
For posterior communicating artery aneurysms, the optic nerve was located and the sylvian fissure was split from its medial end laterally for about 1.5 cm when the internal carotid became visible, allowing proximal control and navigation to the aneurysm site. The narrow craniotomy precludes the use of a standard clip applicator, so we used Mizuhoika type applicators as supplied by Aesculap. The dura was closed and the bone flap fixed with plates. The skin was closed with 4/0 interrupted Nylon sutures that were removed after 48 hours. 4. Results A total of 56 aneurysms were approached, and all were clipped successfully. The locations are given in Table 2. In 3 patients, middle cerebral and posterior communicating artery aneurysms on the same side were clipped through the same approach. In one patient, middle cerebral and internal carotid artery aneurysms on the same side were clipped through the same approach. Three patients underwent a second supraorTable 2 Summary of cases Total cases Male/female Total operations Total aneurysms Ages Emergency/elective Follow-up Locations
Fig. 3. View of the sylvian fissure through the space under the frontal lobe.
47 33:14 50 56 29-72 years; mean, 51 5:43 1-30 months; mean, 7 Posterior communicating: 13; middle cerebral: 40; anterior choroidal: 1; terminal carotid: 2
50
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
bital craniotomy on the other side at a later date. The timing of surgery in patients who presented with an acute SAH ranged from 2 to 10 days with a mean of 3.5 days from the hemorrhage. The aneurysms varied from 2 to 25 mm; 50 were small (size up to 10 mm) and 6 large (11-25 mm). Hospital stay ranged from 4 to 13 days (median of 8 days) for emergency cases, and from 3 to 23 days (median of 5 days) for elective cases. For comparison, there were 47 pterional craniotomies for aneurysms performed electively between 1995 and 2002 at the Newcastle General Hospital. Their stay ranged from 3 to 29 days with a median of 6, not significantly different from the lengths of stay of patients having elective supraorbital craniotomies. Two intraoperative ruptures occurred. One was of a posterior communicating artery aneurysm 7 days after an SAH. The rupture was controlled by placing a temporary clip on the internal carotid artery. The other aneurysm to rupture was of the middle cerebral artery, controlled by proximal temporary clipping. In neither case was it necessary to extend the craniotomy. Neither patient suffered long-term morbidity. One patient who was discharged fit and well after a clipping of a middle cerebral aneurysm later died from rupture of a posterior inferior cerebellar artery aneurysm that was not shown on the initial angiogram. Follow-up ranged from 1 to 30 months with a mean of 7 months. Complications related to this approach are listed in Table 3. Forty-four patients had good outcomes. One elective patient with a 9-mm left middle cerebral artery aneurysm had mild weakness of the arm 1 year postoperatively, but was living independently and was considered to be moderately disabled. Postoperatively, he developed an ipsilateral left hemiparesis. No cause for this could be found on CT or magnetic resonance imaging. One acute patient had 3 fits within 12 months of surgery that were well controlled with phenytoin. Morbidity including epilepsy at 1 Table 3 Adverse events Early complications
Acute/ elective
Outcome at last follow-up
Chronic subdural requiring drainage Chronic subdural requiring drainage Supraorbital numbness and epilepsy
A
Full recovery
E
Full recovery
A
Frontal intracerebral hemorrhage requiring drainage and epilepsy Dysphasia, small extra dural hematoma managed conservatively Left hemiparesis of unknown cause after clipping left MCA aneurysm
E
Recovery of numbness but epilepsy persisted. Good control with phenytoin Full recovery
E
Full recovery
E
Initial good recovery but later died from another aneurysm
A
Persistent left arm weakness (moderate disability) Delayed death
year was thus 4%. Two patients developed postoperative chronic subdural hematomas that required burr hole drainage. One of these was an elective admission; the other presented with an acute SAH. One elective patient had a postoperative intracerebral hematoma removed. All 3 of these patients made a full recovery. Thus, 40 out of 41 elective cases had a good outcome. The cosmetic results have been good, the scar being well hidden by the eyebrow. We have had no persistent woundrelated scalp symptoms. The incision and craniotomy are small when compared to the pterional approach and cause little postoperative pain. Postoperative comfort is subjectively better than with the pterional approach. We have not encountered any cases of pain on chewing or extra cranial collections. 5. Discussion The supraorbital approach was first described as applied to a pituitary tumor by Frazier [4] in 1913. A similar approach to the anterior fossa, midline structures, and orbit was described by Jane et al [7] in 1979. His aim was to gain good exposure while minimizing brain retraction. The operation successfully achieved this aim but was extensive. In the late 1980s and early 1990s, several surgeons began developing minimally invasive supraorbital approaches [3,6,9,10,12,13,15,17]. Many relied on endoscopic visualization. The present series spans 1993 to 2002. We have not used endoscopy to expand the reach of the approach but rather have selected only those cases where we felt microscopic visualization of the aneurysm and feeding vessels would be adequate. These are aneurysms associated with the middle cerebral and internal carotid arteries. Our approach fits into this picture as the least aggressive in exposure and use of equipment but the most limited in treatable lesions. Some justification for our narrow selection criteria comes from the experience of Brydon and Mileki [1] who clipped 41 aneurysms in 34 patients via a supraorbital minicraniotomy. Of the 41 aneurysms, 22 were of the anterior cerebral or anterior communicating arteries. All of his morbidity and mortality (2 deaths and 2 permanent motor deficits) occurred in this subgroup. One of the main advantages of the approach is the minimization of brain retraction. The forward projection of the sylvian fissure passes through the center of the craniotomy. Pterional approaches involve an approach path more lateral than this and thus tend to involve more temporal lobe retraction. The exposure is more restricted than that afforded by a pterional approach, and in the event of an inadvertent rupture, proximal internal carotid artery access could be difficult. This problem of limited access is likely to be aggravated by the presence of brain swelling. We have generally avoided the approach in acute cases for this reason, which means that we have limited experience under those circumstances.
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
The good cosmetic results partly result from using fine skin sutures and removing them early and cannot all be attributed to the minimally invasive nature of the approach. The wound is located on the face rather than behind the hair line, and so wound infection or poor healing are likely to have a worse cosmetic effect than with the pterional approach. The proximity of the frontal sinus is a concern. Some authors have used a pericranial flap to cover the frontal sinus, and we try to avoid it by noting its lateral extent on CT, but we suspect that neither measure totally eliminates the increase in infection rate that this proximity probably engenders. Another concern is that if the free craniotomy flap were to resorb, as sometimes happens, the cosmetic result would be much poorer than would be the result if a pterional flap were to resorb. We have been fortunate in not having encountered these complications.
51
[11] Paladino J, Pirker N, Stimac D, et al. Eyebrow keyhole approach in vascular neurosurgery. Minim Invasive Neurosurg 1998;41(4): 200 - 3. [12] Ramos-Zuniga R. The trans-supraorbital approach. Minim Invasive Neurosurg 1999;42(3):133 - 6. [13] Ramos-Zuniga R, Velazquez H, Barajas MA, et al. Trans-supraorbital approach to supratentorial aneurysms. Neurosurgery 2002;51(1):125 30 [discussion 130-1]. [14] Sanchez-Vazquez MA, Barrera-Calatayud P, Mejia-Villela M, et al. Transciliary subfrontal craniotomy for anterior skull base lesions. Technical note. J Neurosurg 1999;91(5):892 - 6. [15] Steiger HJ, Schmid-Elsaesser R, Stummer W, et al. Transorbital keyhole approach to anterior communicating artery aneurysms. Neurosurgery 2001;48(2):347 - 51 [discussion 351-2]. [16] Taniguchi M, Perneczky A. Subtemporal keyhole approach to the suprasellar and petroclival region: microanatomic considerations and clinical application. Neurosurgery 1997;41(3):592 - 601. [17] van Lindert E, Perneczky A, Fries G, et al. The supraorbital keyhole approach to supratentorial aneurysms: concept and technique. Surg Neurol 1998;49(5):481 - 9 [discussion 489-90].
6. Conclusion Selected aneurysms of the middle cerebral and internal carotid arteries can be clipped via a supraorbital minicraniotomy. Advantages of the approach are a straight bline of sight Q surgical route requiring minimal dissection and brain retraction and a small surgical incision with good cosmetic results. References [1] Brydon H, Mileki TA. Modified supraorbital microcraniotomy—a minimally invasive approach for open aneurysm surgery. Middlesbrough7 Society of British Neurological Surgeons; 2002. [2] Dare AO, Landi MK, Lopes DK, et al. Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation. Technical note. J Neurosurg 2001;95(4):714 - 8. [3] Delashaw Jr JB, Jane JA, Kassell NF, et al. Supraorbital craniotomy by fracture of the anterior orbital roof. Technical note. J Neurosurg 1993;79(4):615 - 8. [4] Frazier CH. An approach to the hypophysis through the anterior cranial fossa. Ann Surg 1913;57:145 - 50. [5] Fries G, Perneczky A, van Lindert E, et al. Contralateral and ipsilateral microsurgical approaches to carotid-ophthalmic aneurysms. Neurosurgery 1997;41(2):333 - 42 [discussion 342-3]. [6] Goel A. Supraorbital craniotomy. J Neurosurg 1994;81(4):642 - 3. [7] Jane JA, Park TS, Pobereskin LH, et al. The supraorbital approach: technical note. Neurosurgery 1982;11(4):537 - 42. [8] Jennett B, Bond M. Assessment of outcome after severe brain damage. Lancet 1975;1(7905):480 - 4. [9] Jho HD. Orbital roof craniotomy via an eyebrow incision: a simplified anterior skull base approach. Minim Invasive Neurosurg 1997;40(3): 91 - 7. [10] Ko Y, Yi HJ, Kim YS, et al. Eyebrow incision using tattoo for anterior fossa lesions: technical case reports. Minim Invasive Neurosurg 2001;44(1):17 - 20.
Commentary This report is a retrospective analysis of 56 aneurysm clippings in 47 patients performed by Dr Mendelow over a 10-year interval. Although this technique (usually combined with endoscopy) has been previously reported [1,2], this article makes some novel observations and confirms the potential utility of this approach for certain lesions of the anterior circulation. As the authors note, the supraorbital minicraniectomy is not well suited for anterior projecting, small or giant aneurysms, acute SAH, or anterior communicating artery aneurysms. On the other hand, for carefully selected aneurysms, the limited brain retraction and small incision may reduce morbidity and facilitate a faster recovery. Neurosurgeons should be familiar with this technique for minimally invasive approaches to paraclinoid lesions. Marc R. Mayberg, MD Department of Neurological Surgery Cleveland Clinic Foundation Cleveland, OH 44195, USA References [1] Brydon HTA, Mikleki A. Modified supraorbital microcraniotomy—a minimally invasive approach for open aneurysm surgery. Middlesbrough7 Society of British Neurological Surgeons; 2002. [2] Dare AO, Landi MK, Lopes DK. Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation. Technical note. J Neurosurg 2001;95:714 - 8.
Technique
Supraorbital eyebrow minicraniotomy for anterior circulation aneurysms Patrick Mitchell, FRCSa,*, R.R. Vindlacheruvu, FRCSa, Khalid Mahmood, FRCSb, Richard D. Ashpole, FRCSc, Athanasios Grivas, FRCSd, A. David Mendelow, FRCSa a
Department of Neurosurgery, Newcastle General Hospital, NE4 6BE Newcastle, UK b King Edward Medical College Lahore, Pakistan c Department of Neurosurgery, Queen’s Medical Centre, Nottingham, UK d Neurosurgery Department, Hellenic Air Force Hospital, Athens, Greece Received 8 December 2003; accepted 23 February 2004
Abstract
Background: We report our experience with the minimally invasive supraorbital approach to aneurysms of the ipsilateral anterior cerebral circulation. Methods: A prospective review of all patients who underwent operations to clip aneurysms in Newcastle between 1993 and 2002. Results: Fifty-six aneurysms were clipped via minicraniotomy in 47 patients. Six patients presented with acute subarachnoid hemorrhage (SAH), 40 patients were admitted for elective clipping, and 1 patient presented with an SAH, had the responsible aneurysm clipped and was readmitted later for elective clipping of a further aneurysm. Bilateral supraorbital craniotomies were performed in 3 patients. In 6 patients, multiple aneurysms were clipped via a single craniotomy. All aneurysms were well visualized with the microscope. Endoscopic assistance was not found necessary. All were successfully clipped. Two aneurysms ruptured while being clipped. There was no direct mortality from surgery. One patient died later from a separate posterior circulation aneurysm. One patient had a significant long-term deficit but remained independent, and 1 had 3 seizures over the 12 months after surgery. This represents a 4% morbidity at 1 year. Conclusion: Selected anterior cerebral circulation aneurysms can be clipped with low morbidity, using an ipsilateral minicraniotomy preserving the orbital rim, and without using an endoscope. The types of aneurysm selection criteria and operative equipment used are described. D 2005 Published by Elsevier Inc.
Keywords:
Minicraniotomy; Cerebral aneurysm
1. Introduction There has long been an impetus to move toward less invasive surgery, and the introduction of improved equipment often leads to significant gains in this area. The availability of high performance operating microscopes and endoscopes has allowed a dramatic reduction in the size of the skull opening required to gain neurosurgical access. The supraorbital eyebrow minicraniotomy is a product of this process. The approach with reliance on endoscopic visualization has been used successfully for a wide range of skull base pathologies, including tumors [9,14,16], and
* Corresponding author. E-mail address: [email protected] (P. Mitchell). 0090-3019/$ – see front matter D 2005 Published by Elsevier Inc. doi:10.1016/j.surneu.2004.02.030
vascular access [2,5,11-13,17]. We have applied the approach to the clipping of aneurysms and from the outset have selected only those cases where the aneurysms and proximal feeding vessels could be visualized directly with a microscope. 2. Patients and methods 2.1. Selection criteria Only aneurysms of the anterior circulation were considered. They were excluded if it appeared from the angiogram that the neck could not be visualized from the front without significant retraction on the aneurysm. Thus, small aneurysms and those projecting laterally or posteriorly were included. Aneurysms projecting anteriorly were assessed on
48
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
Table 1 Patient outcomes at last follow-up (n = 47)
3. Operative technique
Outcome (GOS [8] )
Elective
Acute SAH
All
Good recovery Epilepsy only Moderate disability Severe disability Vegetative Dead (later)
40 0 1 0 0 0
5 1 0 0 0 1a
44 (one had both) 1 1 0 0 1a
a
Died of a subarachnoid hemorrhage from a different aneurysm.
angiography. If the fundus was found to lie directly anterior to the neck and was large enough to obscure it when viewed from an anterior direction, the approach was not used. All anterior communicating complex aneurysms were excluded because of the difficulty in controlling the contralateral proximal vessels. No contralateral clipping was undertaken. Forty-seven patients with anterior circulation aneurysms were treated with the supraorbital craniotomy between February 1993 and October 2002 by the senior author (ADM) at the Department of Neurosurgery, Newcastle General Hospital. Data from these patients were collected prospectively. Clinical presentation was recorded including World Federation of Neurosurgical Societies grading in patients presenting with subarachnoid hemorrhage (SAH). Aneurysm location and size, intraoperative and postoperative complications, and outcome were also recorded. Patients’ ages ranged from 29 to 72 years with mean of 51. There were 33 females and 14 males. Seven patients were admitted as bemergencies Q after SAH, 5 were in World Federation of Neurosurgical Societies grade 1, and 2 were in grade 2. Forty patients were admitted electively for clipping of aneurysms. Of these, 1 had suffered a confirmed SAH 7 years previously, and 2 others had suffered headaches compatible with SAH 3 and 4 years previously, but SAH had not been confirmed. The remaining 37 patients had unruptured aneurysms clipped. In addition to these, one patient fell into both emergency and elective groups, was admitted with an SAH, and found to have multiple aneurysms. The ruptured one was clipped acutely, and the patient was readmitted after 2 weeks for clipping of the remaining aneurysms. Of the 41 patients with aneurysms that had not ruptured acutely, 12 had a history of a previous SAH and operative treatment of another aneurysm, 4 had a strong family history of SAH, and 1 had polycystic kidney disease. The remaining 24 patients had aneurysms found on investigation of other conditions. Eight of these were for headaches not thought to be related to the aneurysms found, 7 were for transient ischemic attacks, 2 for multiple sclerosis, 2 for dizziness, 1 for trigeminal neuralgia, 1 for tinnitus, 1 for a cerebellar hematoma, and 1 after an intraventricular hemorrhage. Neither of the 2 hemorrhages was contiguous with the aneurysms found. The outcome at the last available follow-up was assessed according to the Glasgow Outcome Scale (GOS) [8] (Table 1).
The technique used was substantially similar to that used by van Lindert et al [17], except that no reliance was placed on endoscopy, and the clip applicator was a bMizuhoikaQ type (Aesculap). A lumbar drain was used in all cases. A Budde Halo retractor system was used in all cases. The patient was positioned supine with the neck extended and turned about 208 to the contralateral side. This allowed the subfrontal subdural space to open as the frontal lobe fell superiorly under gravity. The upper half of the eyebrow was shaved. The skin incision extended laterally from immediately lateral to the supraorbital notch to about 2 cm lateral to the superior temporal line (Fig. 1). The incision was placed in a skin crease or where it would later be hidden by the eyebrow. The temporalis fascia and muscle were incised in the line of the skin incision. The limited muscle incision appears to avoid postoperative pain on mastication. A mini– burr hole was made behind the superior temporal line just above the zygomatic process of the frontal bone. Occasionally, the orbit was inadvertently entered, but this led to no long-term ill effects. A free bone flap was turned using a fine craniotome (Fig. 2). The width of the craniotomy was approximately 3 cm (2.5 cm anteriorly and 1 cm toward sphenoid wing) and the height measured 1.5 to 2 cm. Inspection of the pre operative computed tomography (CT) scan allowed the craniotomy to be optimally placed to allow access to the particular aneurysm while avoiding the frontal
Fig. 1. The position of the skin incision in this case is in the left eyebrow.
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
49
Fig. 4. View of the middle cerebral artery complex once the sylvian fissure is opened in an approach to a middle cerebral aneurysm. If a posterior communicating artery aneurysm is being approached, the fissure is opened at its medial end rather than in the middle as shown here.
Fig. 2. The location, size, and shape of the craniotomy.
sinus. The approach was not used in cases where the frontal sinus was large enough to inevitably be involved in the craniotomy. Early in the series, we used endoscopes to assess their utility in the approach. Straight ahead, 308 and 708 rigid endoscopes as well as flexible endoscopes were tried. For middle cerebral artery aneurysms, the frontal lobe was retracted upward (Fig. 3). The lesser wing of the sphenoid was not removed. The sylvian fissure was entered in its middle portion and was split along a length of around 2.5 cm. In general, it was not split to its medial limit (Fig. 4).
For posterior communicating artery aneurysms, the optic nerve was located and the sylvian fissure was split from its medial end laterally for about 1.5 cm when the internal carotid became visible, allowing proximal control and navigation to the aneurysm site. The narrow craniotomy precludes the use of a standard clip applicator, so we used Mizuhoika type applicators as supplied by Aesculap. The dura was closed and the bone flap fixed with plates. The skin was closed with 4/0 interrupted Nylon sutures that were removed after 48 hours. 4. Results A total of 56 aneurysms were approached, and all were clipped successfully. The locations are given in Table 2. In 3 patients, middle cerebral and posterior communicating artery aneurysms on the same side were clipped through the same approach. In one patient, middle cerebral and internal carotid artery aneurysms on the same side were clipped through the same approach. Three patients underwent a second supraorTable 2 Summary of cases Total cases Male/female Total operations Total aneurysms Ages Emergency/elective Follow-up Locations
Fig. 3. View of the sylvian fissure through the space under the frontal lobe.
47 33:14 50 56 29-72 years; mean, 51 5:43 1-30 months; mean, 7 Posterior communicating: 13; middle cerebral: 40; anterior choroidal: 1; terminal carotid: 2
50
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
bital craniotomy on the other side at a later date. The timing of surgery in patients who presented with an acute SAH ranged from 2 to 10 days with a mean of 3.5 days from the hemorrhage. The aneurysms varied from 2 to 25 mm; 50 were small (size up to 10 mm) and 6 large (11-25 mm). Hospital stay ranged from 4 to 13 days (median of 8 days) for emergency cases, and from 3 to 23 days (median of 5 days) for elective cases. For comparison, there were 47 pterional craniotomies for aneurysms performed electively between 1995 and 2002 at the Newcastle General Hospital. Their stay ranged from 3 to 29 days with a median of 6, not significantly different from the lengths of stay of patients having elective supraorbital craniotomies. Two intraoperative ruptures occurred. One was of a posterior communicating artery aneurysm 7 days after an SAH. The rupture was controlled by placing a temporary clip on the internal carotid artery. The other aneurysm to rupture was of the middle cerebral artery, controlled by proximal temporary clipping. In neither case was it necessary to extend the craniotomy. Neither patient suffered long-term morbidity. One patient who was discharged fit and well after a clipping of a middle cerebral aneurysm later died from rupture of a posterior inferior cerebellar artery aneurysm that was not shown on the initial angiogram. Follow-up ranged from 1 to 30 months with a mean of 7 months. Complications related to this approach are listed in Table 3. Forty-four patients had good outcomes. One elective patient with a 9-mm left middle cerebral artery aneurysm had mild weakness of the arm 1 year postoperatively, but was living independently and was considered to be moderately disabled. Postoperatively, he developed an ipsilateral left hemiparesis. No cause for this could be found on CT or magnetic resonance imaging. One acute patient had 3 fits within 12 months of surgery that were well controlled with phenytoin. Morbidity including epilepsy at 1 Table 3 Adverse events Early complications
Acute/ elective
Outcome at last follow-up
Chronic subdural requiring drainage Chronic subdural requiring drainage Supraorbital numbness and epilepsy
A
Full recovery
E
Full recovery
A
Frontal intracerebral hemorrhage requiring drainage and epilepsy Dysphasia, small extra dural hematoma managed conservatively Left hemiparesis of unknown cause after clipping left MCA aneurysm
E
Recovery of numbness but epilepsy persisted. Good control with phenytoin Full recovery
E
Full recovery
E
Initial good recovery but later died from another aneurysm
A
Persistent left arm weakness (moderate disability) Delayed death
year was thus 4%. Two patients developed postoperative chronic subdural hematomas that required burr hole drainage. One of these was an elective admission; the other presented with an acute SAH. One elective patient had a postoperative intracerebral hematoma removed. All 3 of these patients made a full recovery. Thus, 40 out of 41 elective cases had a good outcome. The cosmetic results have been good, the scar being well hidden by the eyebrow. We have had no persistent woundrelated scalp symptoms. The incision and craniotomy are small when compared to the pterional approach and cause little postoperative pain. Postoperative comfort is subjectively better than with the pterional approach. We have not encountered any cases of pain on chewing or extra cranial collections. 5. Discussion The supraorbital approach was first described as applied to a pituitary tumor by Frazier [4] in 1913. A similar approach to the anterior fossa, midline structures, and orbit was described by Jane et al [7] in 1979. His aim was to gain good exposure while minimizing brain retraction. The operation successfully achieved this aim but was extensive. In the late 1980s and early 1990s, several surgeons began developing minimally invasive supraorbital approaches [3,6,9,10,12,13,15,17]. Many relied on endoscopic visualization. The present series spans 1993 to 2002. We have not used endoscopy to expand the reach of the approach but rather have selected only those cases where we felt microscopic visualization of the aneurysm and feeding vessels would be adequate. These are aneurysms associated with the middle cerebral and internal carotid arteries. Our approach fits into this picture as the least aggressive in exposure and use of equipment but the most limited in treatable lesions. Some justification for our narrow selection criteria comes from the experience of Brydon and Mileki [1] who clipped 41 aneurysms in 34 patients via a supraorbital minicraniotomy. Of the 41 aneurysms, 22 were of the anterior cerebral or anterior communicating arteries. All of his morbidity and mortality (2 deaths and 2 permanent motor deficits) occurred in this subgroup. One of the main advantages of the approach is the minimization of brain retraction. The forward projection of the sylvian fissure passes through the center of the craniotomy. Pterional approaches involve an approach path more lateral than this and thus tend to involve more temporal lobe retraction. The exposure is more restricted than that afforded by a pterional approach, and in the event of an inadvertent rupture, proximal internal carotid artery access could be difficult. This problem of limited access is likely to be aggravated by the presence of brain swelling. We have generally avoided the approach in acute cases for this reason, which means that we have limited experience under those circumstances.
P. Mitchell et al. / Surgical Neurology 63 (2005) 47–51
The good cosmetic results partly result from using fine skin sutures and removing them early and cannot all be attributed to the minimally invasive nature of the approach. The wound is located on the face rather than behind the hair line, and so wound infection or poor healing are likely to have a worse cosmetic effect than with the pterional approach. The proximity of the frontal sinus is a concern. Some authors have used a pericranial flap to cover the frontal sinus, and we try to avoid it by noting its lateral extent on CT, but we suspect that neither measure totally eliminates the increase in infection rate that this proximity probably engenders. Another concern is that if the free craniotomy flap were to resorb, as sometimes happens, the cosmetic result would be much poorer than would be the result if a pterional flap were to resorb. We have been fortunate in not having encountered these complications.
51
[11] Paladino J, Pirker N, Stimac D, et al. Eyebrow keyhole approach in vascular neurosurgery. Minim Invasive Neurosurg 1998;41(4): 200 - 3. [12] Ramos-Zuniga R. The trans-supraorbital approach. Minim Invasive Neurosurg 1999;42(3):133 - 6. [13] Ramos-Zuniga R, Velazquez H, Barajas MA, et al. Trans-supraorbital approach to supratentorial aneurysms. Neurosurgery 2002;51(1):125 30 [discussion 130-1]. [14] Sanchez-Vazquez MA, Barrera-Calatayud P, Mejia-Villela M, et al. Transciliary subfrontal craniotomy for anterior skull base lesions. Technical note. J Neurosurg 1999;91(5):892 - 6. [15] Steiger HJ, Schmid-Elsaesser R, Stummer W, et al. Transorbital keyhole approach to anterior communicating artery aneurysms. Neurosurgery 2001;48(2):347 - 51 [discussion 351-2]. [16] Taniguchi M, Perneczky A. Subtemporal keyhole approach to the suprasellar and petroclival region: microanatomic considerations and clinical application. Neurosurgery 1997;41(3):592 - 601. [17] van Lindert E, Perneczky A, Fries G, et al. The supraorbital keyhole approach to supratentorial aneurysms: concept and technique. Surg Neurol 1998;49(5):481 - 9 [discussion 489-90].
6. Conclusion Selected aneurysms of the middle cerebral and internal carotid arteries can be clipped via a supraorbital minicraniotomy. Advantages of the approach are a straight bline of sight Q surgical route requiring minimal dissection and brain retraction and a small surgical incision with good cosmetic results. References [1] Brydon H, Mileki TA. Modified supraorbital microcraniotomy—a minimally invasive approach for open aneurysm surgery. Middlesbrough7 Society of British Neurological Surgeons; 2002. [2] Dare AO, Landi MK, Lopes DK, et al. Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation. Technical note. J Neurosurg 2001;95(4):714 - 8. [3] Delashaw Jr JB, Jane JA, Kassell NF, et al. Supraorbital craniotomy by fracture of the anterior orbital roof. Technical note. J Neurosurg 1993;79(4):615 - 8. [4] Frazier CH. An approach to the hypophysis through the anterior cranial fossa. Ann Surg 1913;57:145 - 50. [5] Fries G, Perneczky A, van Lindert E, et al. Contralateral and ipsilateral microsurgical approaches to carotid-ophthalmic aneurysms. Neurosurgery 1997;41(2):333 - 42 [discussion 342-3]. [6] Goel A. Supraorbital craniotomy. J Neurosurg 1994;81(4):642 - 3. [7] Jane JA, Park TS, Pobereskin LH, et al. The supraorbital approach: technical note. Neurosurgery 1982;11(4):537 - 42. [8] Jennett B, Bond M. Assessment of outcome after severe brain damage. Lancet 1975;1(7905):480 - 4. [9] Jho HD. Orbital roof craniotomy via an eyebrow incision: a simplified anterior skull base approach. Minim Invasive Neurosurg 1997;40(3): 91 - 7. [10] Ko Y, Yi HJ, Kim YS, et al. Eyebrow incision using tattoo for anterior fossa lesions: technical case reports. Minim Invasive Neurosurg 2001;44(1):17 - 20.
Commentary This report is a retrospective analysis of 56 aneurysm clippings in 47 patients performed by Dr Mendelow over a 10-year interval. Although this technique (usually combined with endoscopy) has been previously reported [1,2], this article makes some novel observations and confirms the potential utility of this approach for certain lesions of the anterior circulation. As the authors note, the supraorbital minicraniectomy is not well suited for anterior projecting, small or giant aneurysms, acute SAH, or anterior communicating artery aneurysms. On the other hand, for carefully selected aneurysms, the limited brain retraction and small incision may reduce morbidity and facilitate a faster recovery. Neurosurgeons should be familiar with this technique for minimally invasive approaches to paraclinoid lesions. Marc R. Mayberg, MD Department of Neurological Surgery Cleveland Clinic Foundation Cleveland, OH 44195, USA References [1] Brydon HTA, Mikleki A. Modified supraorbital microcraniotomy—a minimally invasive approach for open aneurysm surgery. Middlesbrough7 Society of British Neurological Surgeons; 2002. [2] Dare AO, Landi MK, Lopes DK. Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation. Technical note. J Neurosurg 2001;95:714 - 8.