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.     

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.     

Cranio-orbital approach for complex aneurysmal surgery

Certain aneurysms of the anterior circulation continue to offer a technical challenge for safe exposure and clipping. The purpose of this paper was to describe the cranio-orbital approach for surgical clipping of complex aneurysms and to evaluate prospectively the associated complications of this approach. Prospective audit of all patients undergoing cranio-orbital approach for aneurysm surgery from 1997 to 2004 by the senior author. Twenty-five patients, eight male and 17 female, median age of 52 years, range 28-73. All patients had a standard pterional approach supplemented by an orbital osteotomy. In the 7-year period 367 patients underwent treatment for their aneurysms (169 clipped and 198 coiled). Of the 169 patients who were operated on, 29 had a skull base approach, of which 25 were cranio-orbital. The aneurysm location was as follows: 16 middle cerebral artery (MCA), three carotid bifurcation, four anterior communicating artery (ACOMM), one ophthalmic and one basilar. There were no approach-related complications. The cranio-orbital craniotomy can be a useful adjunct in the surgical treatment of giant or complex aneurysms. It offers the following advantages over a standard pterional approach: reduces operative distance; allows easy splitting of the sylvian fissure; and provides a wide arc of exposure with multiple working corridors.     

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.     

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.     

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.     

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.     

Surgical treatment of bilateral multiple intracranial aneurysms. Review of a personal experience in 69 cases

AIM: There has been much controversy concerning the surgical treatment of bilateral multiple intracranial aneurysms. Some authors advocate the use of two-stage surgery by bilateral pterional craniotomies and others advocate the one stage complete repair of all lesions using the contralateral approach. We analyze the surgical experience of one neurosurgeon using both approaches. METHODS: Sixty nine patients operated on for bilateral multiple intracranial aneurysms were divided in three groups: group A comprised 43 patients (62.3%) in whom all bilateral aneurysms were treated by one stage operation; group B comprised 9 patients (13.0%) in whom the clipping of the contralateral aneurysm it was not possible through the same approach, needing a second operation; group C comprised 17 patients (24.7%) in whom all bilateral multiple intracranial aneurysms were treated by two stage operations. RESULTS: According to the Glasgow Outcome Scale 61 cases (88.4%) had excellent or good results (GOS V, IV), 2 cases (2.9%) had fair results (GOS III) and 6 patients have died (GOS I). The results of group A were significantly better than in-group B (p<0,05 Fisher test), but they were not different in relation to the group C (p=0,439 Fisher test). Among the six deaths, only one was related to the surgical procedure. CONCLUSIONS: Under favorable clinical situations, as patients in H&H I to III, good brain conditions during the surgical procedure and aneurysms smaller than 1,5 cm, the contralateral surgical approach for the treatment of patients with bilateral multiple intracranial aneurysms can be used with advantages over the two stage approach.     

Supraorbital microcraniotomy for acute aneurysmal subarachnoid haemorrhage: results of first 50 cases

For the past 50 years the pterional craniotomy has been the standard approach for anterior circulation aneurysms. However, this is a major procedure. As the trend is towards minimally invasive surgery generally, we have been developing a minimally invasive approach for anterior circulation aneurysms - the supraorbital microcraniotomy. We present first 50 patients who underwent this operation after an aneurysmal subarchnoid haemorrhage. The data were collected prospectively between 2001 and 2004. A total of 60 aneurysms were clipped (10 patients had two aneurysms). Forty-one of fifty patients (82%) were good grade (WFNS I and II) and 9/50 (18%) were poor grade (WFNS III - V) at the time of surgery. Anterior communicating aneurysms were the commonest (37%), but aneurysms at all of the usual anterior circulation sites were included, apart from ophthalmic aneurysms, as none presented during this period, and pericallosal aneurysms, which were not appropriate for it. Five patients (10%) also had an intracerebral haematoma on presentation. The overall management mortality for this series was 3/50 (6%) with 82% achieving a favourable outcome on the Glasgow Outcome Scale (GOS). For those in good grade at surgery, the mortality was 1/41 (2.4%) with 87.7% achieving a favourable outcome on the GOS.     

Pterional keyhole approach to middle cerebral artery aneurysms through an outer canthal skin incision.

OBJECT: The supraorbital keyhole approach via an eyebrow skin incision provides a method for the minimally invasive clipping of aneurysms located in the circle of Willis, but has disadvantages for aneurysms located in the lateral Sylvian fissure. The pterional keyhole minicraniotomy via an outer canthal skin incision is proposed for the clipping of unruptured aneurysms of the middle cerebral artery (MCA). METHODS: The procedure consists of a 35-mm outer canthal skin incision, partial temporal muscle dissection restricted in the pterion, a 20-25-mm keyhole minicraniotomy, and a 15-20-mm dural incision to expose the lateral Sylvian fissure. Twenty keyhole clipping procedures were performed in 20 patients with unruptured MCA aneurysms. RESULTS: Only one patient showed a temporary mild hemiparesis (reversible ischemic neurological deficit) due to lacunar infarction. No shaving of scalp hair, drain placement, or anticonvulsant drug administration were required. Most patients were discharged on the 2nd or 3rd postoperative day. One patient showed a weakness of the frontalis muscle, but this complication was eliminated by the definition of a safety zone to avoid damage to the frontal branch of the facial nerve. CONCLUSIONS: The pterional keyhole approach via outer an canthal skin incision is another treatment option for relatively small, unruptured MCA aneurysms.     

Is eyebrow approach suitable for ruptured anterior circulation aneurysms on early stage: a prospective study at a single institute

Objective  A prospective study was underway to evaluate the outcome of eyebrow keyhole approach for ruptured anterior circulation aneurysms on early stage. Methods  In the past 4 years, 88 patients with ruptured anterior circulation aneurysms, were operated on early stage by an experienced neurosurgical team through eyebrow craniotomy. The clinical data were analyzed. Results  Patients with Hunt and Hess Grade I–II (85.2%) or III (14.8%) were selected for eyebrow approach on early stage. All aneurysms were small (20.5%) or middle (79.5%) in size. All but seven (92.0%) aneurysms were clipped successfully. The opening of frontal sinus occurred in 11(12.5%) cases through eyebrow approach. Of all, 78 (88.6%) patients achieved favorable outcomes. Conclusions  Eyebrow keyhole approach for ruptured anterior circulation aneurysms on early stage might be in particular selected according to the Hunt and Hess Scale, the projection of aneurysm, the length of M1 segment, the location of cerebral hematoma, the size and complexity of aneurysm, as well as the preference and experience of the neurosurgical team.     

The impact of interventional neuroradiology on neurosurgical training

Aneurysmal subarachnoid haemorrhage carries a high mortality and morbidity. Surgical treatment (craniotomy and clipping of the aneurysm) has been, until recently, the gold standard treatment. Endovascular embolisation treatment has rapidly evolved and the evidence available suggests that the results are as good as surgery. Endovascular treatment successfully occludes the aneurysm to prevent re-haemorrhage, whilst reducing the procedural morbidity when compared to craniotomy and clipping. It is perceived to be of particular benefit for aneurysms in the posterior cerebral circulation where operative morbidity and mortality are significantly higher than for aneurysms on the anterior circle of Willis. The establishment of endovascular treatment has reduced the number of cases being treated surgically, and this has had a significant effect on surgical training. We analysed the management of all ruptured aneurysms treated in our unit over a 4-year period. During the same period, an endovascular service was established in the unit. We devised a novel system for the angiographic grading of aneurysms in order to evaluate the impact that coiling has had on surgical training. The results show that as few as four aneurysms per year would be appropriate for specialist registrars to operate upon. We propose some mechanisms for maintaining high quality surgical training.     

大脑中动脉巨大型动脉瘤的手术治疗

目的 探讨大脑中动脉巨大型动脉瘤的手术治疗方法.方法 回顾性分析2001年1月至2008年3月17例颅内大脑中动脉巨大型动脉瘤患者的手术方法和疗效.术前采用CT、CTA、MR、MRA、DSA及三维DSA检查,以了解动脉瘤的部位、大小,形状以及侧支代偿情况,制定个体化治疗方案.在手术入路上多采用改良翼点入路,其中行动脉瘤瘤颈直接或塑形夹闭者4例,动脉瘤孤立或孤立后切除4例,动脉瘤切除或孤立后血管重建7例,动脉瘤包裹2例.结果 CT和MRI能清楚地显示动脉瘤的形状、大小.DSA及三维DSA能显示瘤颈以及与附近血管和骨质的关系.根据格拉斯骨预后评分表评分,出院时恢复优良者12例,中度病残4例,重度病残1例,无死亡病例.结论 术前有必要进行详细的影像学检查,有助于术者规划手术方法,制定个体化治疗方案,采用不同术式取得良好预后.载瘤动脉暂时性阻断、动脉瘤切开血栓清除均有助于瘤颈夹闭.血管重建技术为大脑中动脉巨大型动脉瘤的手术治疗开辟了新途径,明显改善了手术效果.     

前循环动脉瘤的诊治(附56例报告)

目的探讨前循环动脉瘤的诊断方法,治疗时机的选择,术中注意事项及术后处理的相关问题。方法回顾性分析确诊为颅内前循环动脉瘤的56例患者的临床资料,包括检查手段、手术时机、手术方法、术后处理及预后。结果在56例患者61个动脉瘤中,直接手术夹闭57个,行载瘤动脉孤立术2例(均为眼动脉瘤),行动脉瘤包裹术2例(眼动脉瘤1例,前交通动脉瘤1例)。本组治愈40例(71.4%),轻残6例,重残4例,植物生存2例,死亡4例(7.1%)。结论三维DSA使动脉瘤的诊断更加准确;动脉瘤确诊后应尽早手术,翼点入路是治疗前循环动脉瘤行之有效的方法;手术后脑水肿和脑血管痉挛是致残和死亡的主要原因。     

Anterior subtemporal approach for posteriorly projecting posterior communicating artery aneurysms

We report our experience with the anterior subtemporal approach for the posterior communicating artery aneurysm protruding posteriorly. Between 2000 and 2005, seven patients with posterior communicating artery aneurysm were operated on through the anterior subtemporal approach. The approach provided a better view than the pterional approach. This approach seems to be suitable for posteriorly projecting posterior communicating artery aneurysms. The advantages of the anterior subtemporal approach are as follows: (1) It provides a short and a direct trajectory to the aneurysm. (2) Aneurysmal neck and surrounding structures can be easily identified and secured compared with the pterional approach. (3) A previously placed clip for a middle cerebral artery or internal carotid artery aneurysm through the pterional route does not interfere with the clipping surgery for regrown or de novo posterior communicating artery aneurysms.     

A transcavernous-transsellar approach to the basilar tip aneurysms

A series of 11 patients with a basilar tip aneurysm were treated operatively. The aneurysm had ruptured in all cases and caused at least one haemorrhage prior to surgery. Four patients harboured large aneurysms, while in the rest of them the aneurysms were small in size. In all the 11 patients a modified pterional transcavernous-transsellar approach was used which considerably facilitated clipping and secured complete exclusion of all aneurysms, including the large ones. Eight patients made a complete recovery and resumed their original occupation. One is hemiparetic but capable of self care, one is hemiplegic, and one died after surgery. The purpose of this report is to present our modified surgical approach to basilar tip aneurysms, which provides good exposure of the entire region of the bifurcation of the basilar artery and adjacent blood vessels as far as the anterior inferior cerebellar arteries, and requires but minimal retraction of the brain.     

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.     

Trans-supraorbital approach to supratentorial aneurysms

OBJECTIVE: The trans-supraorbital approach has the advantage of combining the keyhole principle with cranial base surgery. The anatomic fields that can be visualized with the use of this procedure have been demonstrated in cadavers, and the advantages and potential surgical applications of this procedure are described in this report. This article is the first to describe a group of intracranial supratentorial aneurysms. METHODS: We used the trans-supraorbital approach in 22 cases of supratentorial aneurysms. In this technique, an incision is made through the eyebrow, then a 3.5-cm craniotomy is performed with en bloc extension to the orbital arch, complemented by different drilling extensions of the orbital roof according to the surgical objective. We describe the anatomic details of the experimental work as well as the clinical results. RESULTS: The trans-supraorbital technique offers an unlimited wide exposure of neurovascular structures in this microsurgical corridor. The craniotomy extension allows greater exposure than the conventional keyhole supraorbital approach, which makes the technique safe for the patient and comfortable for the surgeon. All patient outcomes were successful; no serious complications from the surgical technique occurred. Our success was achieved through better microscopic illumination in the deep field and by gaining access to the complete supratentorial vascular territory with minimal cerebral retraction and an acceptable cosmetic result. CONCLUSION: The trans-supraorbital approach is effective for gaining access to and treating supratentorial aneurysms. Also, the microsurgical field is more convenient in microscope-assisted surgery because total reliance on the endoscope is not required, and minimal brain retraction is needed. This modification of the keyhole procedure also provides multiple surgical options in this microsurgical corridor, using the principles of minimal invasiveness in cranial base surgery.     

Characteristics and surgery of aneurysms of the proximal (A1) segment of the anterior cerebral artery

AIM: Proximal anterior cerebral artery (A1) aneurysms are considered to be rare or even unique. Proper surgical planning around A1 segment is particularly essential in order to avoid injury of tiny perforating arteries. METHODS: In 17 patients with angiographically or intraoperatively diagnosed A1 aneurysms, representing 0.8% of 2 124 aneurysm patients treated surgically at our institution between 1991 and 2003, clinical presentation, neuroradiological findings, surgical treatment methods and outcome were retrospectively analyzed. RESULTS: Sixteen patients presented with subarachnoid hemorrhage; A1 aneurysms were ruptured in 13 cases. Five patients (29%) had multiple aneurysms. In all cases A1 aneurysms were saccular and their maximum diameter ranged from 4 to 25 mm, average, 7.2 mm; in 4 cases they projected from the origin of the perforating artery, in 6 at the bifurcation of the internal carotid artery, in 5 at the anterior communicating artery and in 2 from the convexity of the parent artery. In 15 patients aneurysms were clipped via ipsilateral pterional approach and in the remaining 2, including a case with a second middle cerebral artery aneurysm, through contralateral approach. Eleven patients had excellent outcome, three good, and three died. CONCLUSIONS: Angiograms must be thoroughly analyzed to correctly assess origin of the aneurysmal neck, and to plan the operative procedure as radiological presentations of distal or proximal A1 lesions resemble those of anterior communicating artery and internal carotid artery bifurcation aneurysms, respectively. Contralateral approach may facilitate surgical elimination of selected A1 aneurysms or enable one-stage clipping in patients with multiple bilateral aneurysms.     

Combined endovascular and microsurgical approach in the treatment of giant paraclinoid and vertebrobasilar aneurysms

AIM: The aim of this study is to present the application of endovascular intraoperative occlusion of the parent artery during the microsurgical treatment of giant paraclinoidal internal carotid artery aneurysms (ICA) and of complex vertebrobasilar junction aneurysms . METHODS: Five cases of giant paraclinoidal ICA aneury-sms were treated by direct surgical approach. In the operatory room any patient underwent angiography and balloon occlusion test using a mobile digital subtraction angiograph. Thereafter the catheter was left in the aortic arch. Through an extended pterional craniotomy, it was possible to evidentiate the aneurismal sac. The proximal control of the vessel was achieved inflating a double-lumen balloon; clipping of the aneurysm was achieved, because of pressure lowering inside the aneurysm. Also a giant vertebrobasilar junction aneurysm was treated by this combined technique: using a posterolateral approach the control of the omolateral vertebral artery was obtained by temporary clipping above PICA's origin; the control of controlateral artery was obtained inflating a balloon introduced through the femoral artery. These combined manoeuvres determined sac deflation, allowing an easier clipping. RESULTS: Aneurysm obliteration was achieved with preservation of the circulation without complications in all cases. CONCLUSIONS: The endovascular procedure allows safer and reliable proximal control of paraclinoidal ICA and vertebral artery during the microsurgical treatment of paraclinoid and vertebrobasilar junction aneurysms.