Multiscope Technique Combining an Endoscope and Exoscope for Neck Clipping of Cerebral Aneurysms.

OBJECTIVE: In aneurysm clipping, the use of an endoscope improves the visualization of the anatomic structures around the aneurysm, allowing for improved dissection and clipping techniques. Furthermore, it makes the surgery less invasive. The disadvantage of using the endoscope and microscope together is that the surgeon must move the line of sight significantly between viewing the operative field through the eyepiece of the microscope and viewing the endoscope monitor. This disadvantage makes it difficult for the surgeon to safely insert the endoscope in the optimal position. This study presents a new method for observing the surgical field with a picture-in-picture system using both an endoscope and an exoscope that can overcome the disadvantage of multiscope surgery. METHODS: The endoscope was used when the anatomic structures around the aneurysm could not be observed with the exoscope only. An image from the endoscopic monitor was inserted into the exoscopic monitor. The surgeon inserted the endoscope in the optimal position while viewing the endoscope monitor and ensured that the structures in the path of the endoscope were not damaged while they viewed the exoscope monitor. RESULTS: Three patients underwent aneurysm clipping. The use of an endoscope made the procedure less invasive, and the surgeon was able to safely insert the endoscope in the optimal position. Only slight movement of the line of sight was required to view the 2 monitors. CONCLUSIONS: The endoscope and exoscope multiscope picture-in-picture system can facilitate safer aneurysm clipping compared with combined microscopic and endoscopic surgery.

Outcomes and complications of cerebral aneurysms operated on by eyebrow incision according to aneurysm type and location.

OBJECTIVE: Trans-eyebrow supraorbital aneurysmal neck clipping, also known as keyhole surgery, have many advantages of minimal invasive surgery. However, there are few studies on whether there is a difference in keyhole surgery according to the location of the aneurysm, and how the complications after keyhole approach differ from the conventional approach. The authors investigated the surgical outcome of keyhole aneurysmal surgery for clarify the characteristics of keyhole surgery. METHODS: A retrospective study was performed with review of medical records and images of patients with anterior circulation aneurysm undergoing aneurysmal clipping with keyhole surgery. The patient's clinical condition, imaging, surgical condition, and outcome were investigated. RESULTS: As a result of analysis about the location of the aneurysm, middle cerebral artery (MCA) aneurysm group had a longer operation time than internal carotid artery and anterior cerebral artery aneurysm groups, but there was no significant difference in complication rate. The olfactory dysfunction occurred more than that of conventional surgery and occurred less in MCA aneurysm group than others. Scalp sensory change in the surgical site was more common in patients with unruptured aneurysms. CONCLUSION: By accurately investigating the frequency and severity of complications associated with trans-eyebrow aneurysmal neck clipping surgery, it can help to select a surgical approach considering risk versus benefit. In addition, patient's satisfaction can be increased by providing information to patients and caregivers in advance about the outcome of this approach and the anticipated complications.

Usefulness of Orbitocranial Approach in Neck Clipping of Aneurysms Arising from Middle Cerebral Artery Proximal to the Limen Insulae: A Case Series.

BACKGROUND: Neck clipping of the aneurysms arising from the middle cerebral artery (MCA) proximal to the limen insulae is often difficult because of difficulties in securing a bright and wide operative field to observe the aneurysms and surrounding structures, such as the anterior perforated substance, lenticulostriate arteries, and early frontal branch. Our objective was to determine the usefulness of the orbitocranial approach in neck clipping of the aneurysms arising from the MCA proximal to the limen insulae. METHODS: This prospective study included 7 patients who underwent neck clipping of aneurysms arising from the MCA proximal to the limen insulae through the orbitocranial approach. In addition to conventional pterional craniotomy, the superiolateral orbital rim was resected with a 1-piece fashion. Its procedures, complications, and outcomes were reviewed. RESULTS: Removal of the superolateral orbital rim facilitated a bright and wide observation from the skull base side. It was much easier to identify the anterior perforated substance, lenticulostriate arteries, and early frontal branch around the aneurysm through the orbitocranial approach than through the conventional pterional approach. Neck clipping could be performed completely and safely in all cases. CONCLUSIONS: The orbitocranial approach to aneurysms arising from the MCA proximal to the limen insulae provides us a bright and wide operative field compared with the conventional pterional approach, which is useful to secure complete and safe neck clipping by avoiding cerebral contusion and unexpected obstruction of the early frontal branch.

Incidental Microaneurysms During Microvascular Surgery: Incidence, Treatment, and Significance.

BACKGROUND: Although new imaging tools have been developed for the detection of smaller aneurysms, angiographically negative microaneurysms are still encountered during cerebral microsurgery. Currently, only limited information regarding incidence and efficacy of treatment of these microaneurysms is available. METHODS: We investigated the incidence and treatment of incidental microaneurysms (IMAs) in the last 5 years. IMAs are unidentifiable and invisible on preoperative angiography, but are detected during microvascular surgery. The inclusion criteria were aneurysm cases treated with microsurgery via transsylvian approaches, and those undergoing preoperative digital subtraction angiography. RESULTS: This study enrolled 484 surgical cases (248 cases of subarachnoid hemorrhage and 236 cases of unruptured aneurysms) in 460 patients, and 33 tiny aneurysms were found in 31 operative cases (6.4% incidence per operation). The most typical type was located on another branching site of the middle cerebral artery found during neck clipping of the middle cerebral artery bifurcation aneurysm. A patient with multiple aneurysms presented a statistically significant risk (375/78 vs. 15/16; P < 0.001) of IMA identification. IMAs were treated by clipping and wrapping in 18 and 15 cases, respectively, without complications. CONCLUSIONS: This study revealed a 6.4% incidence of IMAs; however, this could be underestimated because of the limited range of inspection. Early detection of an IMA through careful inspection during microvascular surgery could be beneficial, especially in patients with multiple aneurysms.

Superficial Temporal Artery to Anterior Cerebral Artery Hemi-bonnet Bypass Using Radial Artery Graft for Prevention of Complications after Surgical Treatment of Partially Thrombosed Large/Giant Anterior Cerebral Artery Aneurysm.

BACKGROUND: Partially thrombosed large/giant aneurysm of the anterior cerebral artery is still challenging because this complex aneurysm requires arterial revascularization in the deep operation field. Therefore, direct neck clipping is often impossible. We describe our experiences with extracranial-intracranial bypass as an insurance bypass prior to clipping of partially thrombosed anterior cerebral artery aneurysms, and discuss the microsurgical technique and strategy. CLINICAL PRESENTATION: Consecutive, single-surgeon experience with the surgical treatment of partially thrombosed anterior cerebral artery aneurysms was retrospectively reviewed. Three cases of partially thrombosed anterior cerebral artery aneurysms, 2 anterior communicating artery aneurysms, and 1 postcommunicating artery (A2 segment of the anterior cerebral artery) aneurysm, presented as mass effect symptoms from giant aneurysms in 2 patients and incidentally discovered aneurysm in one patient. Superficial temporal artery-radial artery graft-anterior cerebral artery hemi-bonnet bypass was performed as an insurance bypass prior to clipping of the partially thrombosed anterior cerebral artery aneurysms. Complete aneurysm obliteration and bypass patency were demonstrated in all 3 patients. No neurological sequelae occurred. CONCLUSIONS: Superficial temporal artery-radial artery graft-anterior cerebral artery hemi-bonnet bypass prior to aneurysm dissection can avoid ischemic complication during temporary occlusion and secures permanent revascularization after complete obliteration of partially thrombosed large/giant anterior cerebral artery aneurysm.

Microsurgical Clipping of Basilar Apex Aneurysms: A Systematic Historical Review of Approaches and their Results.

OBJECTIVE: Neck clipping remains a valuable treatment option for basilar apex aneurysms, especially in those with complex morphology, such as incorporation of branching vessels or large size, and young patient age. Several approaches have proved to give effective exposure for various types of lesion morphologies. Our historic literature review from 1976 to the present systematically compares the outcomes and complications of the key surgical approaches in the treatment of basilar apex aneurysms. METHODS: We searched PubMed for articles with at least 5 patients, data on neurologic outcome, and procedure-associated complications for the following approaches: pterional or orbitozygomatic transsylvian, subtemporal (with or without zygomatic osteotomy), pretemporal (with or without transcavernous extension), and transpetrous. n-Weighted averages for clinical outcome, aneurysm occlusion rates, morbidity, mortality, and aneurysm morphology were compared. RESULTS: Of 35 articles selected, 2041 patients with 722 ruptured aneurysms underwent microsurgery, including 1131 transsylvian, 241 pretemporal, 375 subtemporal, and 17 transpetrous approaches. Comparing these 4 approaches in n-weighted averages, respectively, we noted good neurologic outcomes (81%, 85%, 81%, and 58%), surgical morbidity (14%, 10%, 34%, and 53%), surgical mortality (4%, 1%, 0, and 1%), and complete occlusion rates (95%, 94%, 86%, and 75%). CONCLUSIONS: Transsylvian, pretemporal, and subtemporal approaches showed favorable neurologic outcomes at similar rates and were applied for aneurysms located between -1mm and +7mm in relation to the posterior clinoid process. The pretemporal approach was preferably applied to large and giant aneurysms with good outcome; the transsylvian approach was most frequently used for ruptured aneurysms.

A technique for sequential, progressive clipping for a giant thrombosed distal anterior cerebral artery aneurysm: Technical note.

BACKGROUND: Giant thrombosed aneurysms often present with thickened walls and a hard thrombus, including in the near-neck aneurysmal sac. These usually make it difficult to achieve complete neck clipping with preservation of local branch patency. Here, we demonstrate a simple but safe and effective technique to overcome these problems in a patient with a 6-cm giant thrombosed distal anterior cerebral artery aneurysm. CASE DESCRIPTION: A 77-year-old-man suffered from loss of volitional activity due to the frontal mass effect. The aneurysm was exposed with unilateral paramedian craniotomy and an interhemispheric approach. The clip was applied to the aneurysmal neck but it slipped onto the parent artery, which caused branch artery occlusion. Intra-aneurysmal thrombectomy was immediately performed near the aneurysmal neck with ultrasonic aspiration. The next clip was added along the aneurysm side of the preceding clip, which was then removed. This procedure was repeated twice so that complete neck clipping was achieved while preserving the branch patency. All the residual thrombus and aneurysmal wall were subsequently removed. Postoperatively, there was no additional neurological deficit. The patient's mental function was significantly improved. CONCLUSIONS: We conclude that the sequential, progressive clipping technique is a robust option for successful neck clipping of giant thrombosed aneurysms.

A case of unruptured aneurysm of the internal carotid artery presenting as olfactory hallucinations.

BACKGROUND: Olfactory hallucination, a symptom of medial temporal lobe epilepsy, is rarely associated with unruptured intracranial aneurysms. CASE DESCRIPTION: We encountered this situation in a 70-year-old woman with an unruptured aneurysm at the bifurcation of the internal carotid and posterior communicating artery. We were able to achieve epileptic control by craniotomy clipping and medial temporal lesionectomy. CONCLUSION: According to our knowledge, previous reports are limited to cases of large middle cerebral artery aneurysms compressing the lateral orbitofrontal cortex, and this is apparently the first report of a case where olfactory hallucinations occurred from direct stimulation of the entorhinal cortex by an internal carotid and posterior communicating artery bifurcation aneurysm. We examined the pathophysiology underlying the development of olfactory hallucinations. We found craniotomy clipping and focal resection to be useful from the standpoint of seizure control. Whether seizure control can also be obtained with intracranial aneurysm coiling should be investigated in the future.

Risk Factors for Visual Impairments in Patients with Unruptured Intradural Paraclinoid Aneurysms Treated by Neck Clipping without Bypass Surgery.

OBJECTIVE: Although paraclinoid aneurysms are now frequently referred for endovascular treatment, the durability of obliteration is still to be determined. Therefore, direct surgery for paraclinoid aneurysms still remains indispensable. The present study aimed to evaluate the risk factors for the visual impairments in patients with unruptured intradural paraclinoid aneurysms. METHODS: The data of 133 patients with 136 aneurysms treated by neck clipping without bypass surgery was evaluated. Visual impairments included decreased visual acuity and visual field defect. The aneurysm was classified into superior projecting aneurysm, ventral projecting aneurysm, and carotid cave aneurysm. Plug-in method was defined as filling interspace, which was formed between the internal carotid artery and the sutured dura in case of detachment of the dural ring. RESULTS: Postoperative new visual impairments were observed in 30 aneurysms (22%). During the follow-up period (median, 600 days), postoperative new visual impairments continued in 23 aneurysms (17%). Multivariate analysis showed that carotid cave location and plug-in method were related to new visual impairments at 30 days (odds ratio [OR], 2.6; 95% confidence interval [CI] 1.1-6.1; P = 0.031 and OR, 4.1; 95% CI 1.4-12; P = 0.008) and at 6 months (OR, 4.1; 95% CI 1.5-11; P = 0.005 and OR, 3.3; 95% CI 1.1-11; P = 0.045). CONCLUSIONS: The present study showed that carotid cave location and plug-in method during dural closures were related to postoperative continued visual impairments. Neurosurgeons should carefully consider the surgical indication for unruptured carotid cave aneurysms and avoid plug-in methods.

MicroRNA-29a: A potential biomarker in the development of intracranial aneurysm.

AIM: To identify serum microRNA-29a (miR-29a) level in patients with intracranial aneurysm and its role in the development of intracranial aneurysm (IA). METHODS: Case group included 165 IA patients hospitalized in the department of neurosurgery between January 2010 and January 2012 while control group enrolled 220 healthy volunteers. Morning fasting blood samples were collected from peripheral vein. RT-PCR was used for miR-29a detection. Receiver Operating Characteristic (ROC) curve was drawn. Survival curves were drawn for survival analysis with Kaplan-Meier method and Long-rank test was conducted. MiR-29a expression Glasgow Prognosis Score (GOS) was used for prognosis scaling. Multivariate Cox proportional hazards regression analysis was performed for prognosis analysis. Results Cases had significantly higher miR-29a expressions than controls (P<0.05). ROC curve analysis indicated that miR-29a expression in IA had high effectiveness in IA diagnosis. Close associations were identified between miR-29a expression and rupture, Hunt-Hess level and surgical timing (all P<0.05). GOS strongly associated with history of hypertension, aneurysm location, rupture, Hunt-Hess level and miR-29a expression. Patients with low miR-29a expression had longer disease-free survival (DFS) and overall survival (OS) than those with high miR-29a expression (both P<0.05). MiR-29a expression, tumor aneurysm, rupture and Hunt-Hess were risk factors to the prognosis of IA (all P<0.05). CONCLUSION: MiR-29a may be closely related to IA development and therefore could be a useful predicator of IA prognosis, providing a new target for IA therapy.

Spontaneous Regression of Aneurysm Remnant after Incomplete Surgical Clipping in a Patient with Ruptured Cerebral Aneurysm.

Cases of spontaneous regression of cerebral aneurysm remnant after incomplete surgical clipping have been rarely reported. This paper reports the regression of an aneurysm remnant after incomplete surgical clipping during postsurgical follow-up. A 50-year-old male presented with subarachnoid hemorrhage because of rupture of an anterior communicating artery aneurysm. An emergency clipping of the aneurysm was performed. A cerebral angiography, which was performed two weeks postoperatively, revealed an aneurysm remnant. The patient refused additional treatment and was discharged without apparent neurological deficit. One-year follow up cerebral angiography demonstrated a partially regressed aneurysm remnant.

Ruptured aneurysm at the cortical segment of the distal posterior inferior cerebellar artery associated with hemodynamic stress after basilar artery occlusion.

BACKGROUND: A distal posterior inferior cerebellar artery (PICA) de novo aneurysm at the cortical segment after atherosclerotic basilar artery occlusion is extremely rare. Here, we report the case of a ruptured distal PICA de novo aneurysm 8 years after basilar artery occlusion. CASE DESCRIPTION: A 75-year-old man experienced sudden disturbance of consciousness; computed tomography demonstrated cerebellar and subarachnoid hemorrhage due to a ruptured distal PICA aneurysm. Neck clipping of the aneurysm prevented re-rupture initially, and superficial temporal artery-superior cerebellar artery (STA-SCA) bypass was performed 3 months after admission. Postoperative angiography confirmed patency of the bypass, and the patient was discharged without any new neurological deficits. CONCLUSION: This report describes a case of de novo development of a saccular distal PICA aneurysm after atherosclerotic basilar artery occlusion. We believe that increased hemodynamic stress at the PICA might have contributed to the occurrence and rupture of the aneurysm. STA-SCA bypass, introduced in the territory of the cerebellar hemisphere, reduces hemodynamic stress, which would prevent the occurrence of de novo aneurysm and recurrent bleeding.

Spontaneous Regression of Aneurysm Remnant after Incomplete Surgical Clipping in a Patient with Ruptured Cerebral Aneurysm

Cases of spontaneous regression of cerebral aneurysm remnant after incomplete surgical clipping have been rarely reported. This paper reports the regression of an aneurysm remnant after incomplete surgical clipping during postsurgical follow-up. A 50-year-old male presented with subarachnoid hemorrhage because of rupture of an anterior communicating artery aneurysm. An emergency clipping of the aneurysm was performed. A cerebral angiography, which was performed two weeks postoperatively, revealed an aneurysm remnant. The patient refused additional treatment and was discharged without apparent neurological deficit. One-year follow up cerebral angiography demonstrated a partially regressed aneurysm remnant.

Subarachnoid hemorrhage caused by a traffic accident: de novo aneurysm ruptured 30 years after surgical neck clipping.

A man, who had a medical history of surgical neck clipping 30 years previously, died of traffic accident. The medico-legal autopsy showed subarachnoid hemorrhage and ruptured aneurysm on the lateral side of the clip. Microscopic examination showed the aneurysm was not to be regeneration, but a new de novo aneurysm. We diagnosed the cause of death was traumatic aneurysmal rupture. In addition, we discussed the cause of a newly formed de novo aneurysm which may be affected by past surgical neck clipping.

Mortality and Morbidity of Aneurysmal Neck Clipping during the Learning Curve

OBJECTIVE: Young neurosurgeons need to focus on the mortality and morbidity of aneurysmal neck clipping to develop a personal experience with an initial series. METHODS: Total 88 aneurysms from 75 patients who underwent neck clipping by the same operator from 2001 to 2004 were reviewed. Patients were divided into three groups: first year (Group I), second year (Group II), and third year (Group III) in each group. Location of aneurysm, age, Fisher grade, Hunter-Hess grade (H-H grade), postoperative Glasgow outcome scale (GOS), and complications related to surgical procedures were evaluated with Chi-square and logistic regression analyses. RESULTS: Fourteen patients had complications related to surgery (18.7%). The major causes of mortality and morbidity related to surgery were cerebral infarction, hemorrhage and brain swelling due to intraoperative rupture, brain retraction and vasospasm. Among the 4 cases of mortality were 2 patients in Group I, 1 patient in Group II and 1 patient in Group III, and location of aneurysms were 2 internal carotid artery(ICA) and 2 posterior communicating artery(PCoA) aneurysms. There were 4 morbidity and new neurological deficits in Group I, 4 in Group II and 2 in Group III. Although mortality and morbidity during the learning curve had a statistical significance in H-H grade, age (>60 years old), and aneurysm location (especially ICA aneurysm) as variables, mortality mainly occurred in ICA and PCoA aneurysms. CONCLUSION: Experienced supervision or endovascular approach should be considered for the treatment of ICA and PCoA aneurysms during the learning curve.

Surgical Experience of Recurrent Hemorrhage from the Regrowth Cerebral Aneurysm after Initial Neck Clipping: Case Report / 대한뇌혈관외과학회지

The neck clipping of cerebral aneurysm is a well established treatment for the subarachnoid hemorrhage caused by aneurysmal rupture. However, incomplete clipping of an aneurysm may result in recurrent hemorrhage with serious or fatal consequence. Recently, two patients underwent reoperation for recurrent hemorrhage from the regrowth aneurysm after previous clipping operation. The technical obstacles to surgical treatment of these two patients were perianeurysmal adhesion or scar formation, presence of clip and coating agents and so on. One patient showed good outcome, another patient was dead by pneumonia. In order to detect regrowth of aneurysm, periodic examination is very important for the patient with remnant neck after aneurysm clipping operation.

Comparative Study of Treatment Results between Surgical Neck Clipping and Endovascular Coiling on the Ruptured Middle Cerebral Artery Aneurysms

OBJECTIVE: The treatment modalities of cerebral aneurysms mainly consist of surgical neck clipping of aneurysms and endovascular embolization. Through comparing of the treatment results between two methods especially focused on their complicatons, the authors present the efficacy of the treatment modality in ruptured middle cerebral artery aneurysms. METHODS: Patients who admitted due to ruptured middle cerebral artery aneurysm between January 1998 and December 2002 were selected. They have done surgical neck clipping or endovascular embolization which employed platinum coil. Treatment methods were chosen in random fashion. The patient's clinical state were determined before, during, and after the treatment by using Hunt and Hess grade and Glasgow outcome scale(GOS). According to Fisher grade was classified based on the amount of hemorrhage. Statistical analyses were done with Student t-test, Pearson's correlation coefficient, and Mann-Whitney U test. RESULTS: Average follow-up period was 24 months(5 days-36 months) in surgery group and 26 months(8 days-36 months) in endovascular embolization group. There was no statistical significance regard to sex, age, patient's Hunt and Hess grade on admission, the Fisher grade, and aneurysmal size. There was no significant difference between GOS of two groups in statistically(p>0.05). CONCLUSION: This comparative study of reveals no significant difference in neurologic outcomes between two treatment modalities.

Clinical Analysis and Surgical Treatment of Vertebral Aneurysm

Aneurysms of the vertebral artery are relatively uncommon. Diagnois and treatment of such condition aneurysm has a potentially higher degree of technical difficulty. We retrospectively analyzed the clinical features and therapentic outcomes of 12 consecutive patients with vertebral aneurysms that we have encountered during the last 11 years. Most of these aneurysms occured in females (9 of 12). Eight patients presented as classic subarachnoid hemorrhage, three were diagnosed incidentally, and the other one patient had fusiform aneurysm presented with mass effect. Among the 12, there were 7 saccular aneurysms, 2 fusiform aneurysms, and 3 dissecting aneurysms. Eight of these were located at the origin of the posterior inferior cerebellar artery(PICA), two were at the junction of the vertebral and basilar arteries, and two were at the distal portion of PICA. Direct neck clipping was performed in 8 patients and proximal ligation of the vertebral artery was done in 4 patients due to the impossibility of direct neck clipping. Eleven of them experienced no major morbidity. However, one patient with fusiform aneurysm treated by vertebral artery clipping developed right cerebellar hemispheric infarction. Unfortunately this patient died 10 months after surgery due to lung abscess related to Behcet's disease.

Outcome of Ruptured Intracranial Aneurysms Treated by Coating

In rare occasions in which aneurysmal neck clipping is nearly impossible, coating is employed. During the period from 1985 to 1992, 312 patients with aneurysm underwent surgery;aneurysmal neck clipping were performed in 284 cases while coating only in 28. The reasons that coating was required were;wide and broad neck in 13, perforators arising from the neck in 4, neck tearing during dissection in 3, very friable neck in 2, severe adhesion with surrounding structures in 3, and small aneurysm without enough room for clipping in 3. In twenty-three cases, cotton wisp and bioglue were used as coating materials. In another five cases, the aneurysmal wall was reinforced using Surgical or Gelfoam. Patients were followed for 24 months on average of all the patients. Four had last contack. Six died(4 due to rebleeding and 2 due to pneumonia). Fourteen were good and 4 were moderately disabled. There were no rebleeding incidences during first three months' follow-up after coating. We thus concluded that coating an aneurysm offers some protection from rebleeding, particularly when the rebleeding risk period is over.