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Background Alcohol consumption has been reported to deteriorate surgical performance both immediately after consumption as well as on the next day. We studied the early effects of alcohol consumption on microsurgical manual dexterity in a laboratory setting. Method Six neurosurgeons or neurosurgical residents (all male) performed micro- and macro suturing tasks after consuming variable amounts of alcohol. Each participant drank 0–4 doses of alcohol (14 g ethanol). After a delay of 60–157 min, he performed a macrosurgical and microsurgical task (with a surgical microscope). The tasks consisted of cutting and re-attaching a circular latex flap (diameter: 50 mm macrosuturing, 4 mm microsuturing) with eight interrupted sutures (4–0 multifilament macrosutures, 9–0 monofilament microsutures). We measured the time required to complete the sutures, and the amplitude and the frequency of physiological tremor during the suturing. In addition, we used a four-point ordinal scale to rank the quality of the sutures for each task. Each participant repeated the tasks several times on separate days varying the pre-task alcohol consumption (including one sober task at the end of the data collection). Results A total of 93 surgical tasks (47 macrosurgical, 46 microsurgical) were performed. The fastest microsurgical suturing (median 11 min 49 s, [interquartile range (IQR) 654 to 761 s]) was recorded after three doses of alcohol (median blood alcohol level 0.32‰). The slowest microsurgical suturing (median 15 min 19 s, [IQR 666 to 1121 s]) was observed after one dose (median blood alcohol level 0‰). The quality of sutures was the worst (mean 0.70 [standard deviation (SD) 0.48] quality points lost) after three doses of alcohol and the best (mean 0.33 [SD 0.52] quality points lost) after four doses (median blood alcohol level 0.44‰). Conclusions Consuming small amount of alcohol did not deteriorate microsurgical performance in our study. An observed reduction in physiological tremor may partially explain this.

The far lateral approach has been developed to access lesions at the craniocervical junction and upper cervical spinal canal. Associated morbidity triggered the development of less invasive tailored approaches.In this lateral approach to the craniocervical junction, the occipital condyle is kept intact, vertebral artery manipulation is minimized, and the sigmoid sinus is not skeletonized. A linear incision through skin and muscles and use of an abdominal wall fat graft minimize the risk of cerebrospinal fluid leakage.The exposure provided is sufficient for the majority of tumors in this region and allows for low complication rates.

The literature on exoscope use in cerebrovascular neurosurgery is scarce, mainly comprising small case series and focused on visualization quality and ergonomics. As these devices become widely used, direct comparison to the operating microscope regarding efficacy and patient safety is necessary.Fifty-two consecutive clipping procedures, performed by 1 senior vascular neurosurgeon, were analyzed. Either an operating microscope with a mouth switch (25 cases with 27 aneurysms; 13 ruptured) or a three-dimensional exoscope with a foot switch (27 cases with 34 aneurysms; 6 ruptured) were used. Durations of major surgical stages, number of device adjustments, numbers of clip repositionings and clips implanted were extracted from surgical videos. Demographic data, imaging characteristics, clinical course and outcomes were extracted from digital patient records.Duration of surgery and different stages did not differ between devices, except for final site inspection. The number of device adjustments was higher with the exoscope. With progressive experience in exoscope use, the number of device adjustments increased significantly, whereas surgery duration remained unchanged. Favorable outcome (modified Rankin Scale score 0-2) was observed in 80% and 88% of patients in the microscope and exoscope groups, respectively. Ischemic events were found in 2 patients in each group; no other complications occurred.In aneurysm clipping, three-dimensional exoscopes are noninferior to operating microscopes in terms of surgery duration, safety, and outcomes, based on our limited series. Progressive experience enables the surgeon to perform significantly more device adjustments within the same amount of surgical time.

BACKGROUND: The use of a digital three-dimensional (3D) exoscope system in neurosurgery is increasing as an alternative to the operative microscope. The objective of this study was to compare a digital 3D exoscope system with a standard operating microscope as a neurosurgical visualization tool in a highly challenging experimental setting. METHODS: End-to-side bypass procedures, each at a depth of 9 cm, were performed in a simulation setting. The quality of the task and the depth effect, visualization, magnification, illumination, and ergonomics were evaluated. RESULTS: No major differences were noted between the microscope and the 3D exoscope in terms of the quality of the work. Working with the 3D exoscope was more time-consuming than working with the microscope. Changing the depth and focus was faster using the operative microscope. The 3D exoscope enabled higher magnification and offered better ergonomic features. CONCLUSIONS: In a highly challenging experimental setting, comparable procedural quality was found for the microscope and the 3D exoscope. Each visualization tool had advantages and disadvantages. Over time and with technologic advances, the digital 3D exoscope may become the main operative visualization system in microneurosurgery.

Inferior vena cava atresia (IVCA) is a rare vascular condition that may be treated by venous stenting. The authors report on the microsurgical removal of an intraspinally misplaced stent causing nerve root compression and neurological deficits.A 42-year-old patient with IVCA and painful cutaneous collaterals had been scheduled for treatment by stenting of the iliocaval confluence and associated venous collaterals. Initial stenting of the right iliac vein was successful; however, during recanalization of the left paravertebral plexus, the stent entered the spinal canal via extraspinal-to-intraspinal venous collaterals. Because of the use of monoplanar angiography, the stent misplacement was not seen during the procedure. Postinterventionally, the patient experienced a foot elevation weakness (grade 1/5) as well as pain and hypesthesia corresponding to the L5 dermatome. Ultrasonography ruled out a lumbosacral plexus hematoma. CT angiography showed that a stent had entered the spinal canal through the left S1 neuroforamen causing nerve root compression. The intraspinal portion of the stent was removed piecemeal via a left-sided hemilaminectomy. Venous bleeding due to the patient’s anticoagulation therapy, the stent’s sharp mesh wire architecture, and the proximity to nerve roots complicated the surgery. Postoperatively, the foot elevation improved to grade 4/5.

Acta neurochirurgica (2022). doi:10.1007/s00701-022-05458-6, Published by Springer, Wien [u.a.]

Background: Intracranial intraparenchymal schwannomas (IS) are rare tumors that have mainly been described in case reports. Here, we report on a case of a brainstem IS and included a comprehensive literature review. Case Description: A 74-year-old man presented with progressive gait disturbances. CT- and MRI-imaging revealed a contrast-enhancing mass accompanied by a cyst in the dorsolateral pons. Hemangioblastoma was suspected and surgery was advised. During surgery, gross total resection of a non-invasive tumor was performed. Postoperative recovery was uneventful. Based on histopathological examination, the intraparenchymal brainstem tumor was diagnosed as schwannoma. Conclusion: Our extensive review illustrates that ISs are benign tumors that most often present in relatively young patients. Malignant cases have been described but form an extremely rare entity. Preoperative diagnosis based on radiological features is difficult but should be considered when peritumoral edema, calcifications, and cysts are noted. In benign cases, gross total resection of the lesion is curative. To adequately select this treatment and adjust the surgical strategy accordingly, it is important to include IS in the preoperative differential diagnosis when the abovementioned radiological features are present.

OBJECTIVEOcclusive treatment of posterior communicating artery (PCoA) aneurysms has been seen as a fairly uncomplicated procedure. The objective here was to determine the radiological and clinical outcome of patients after PCoA aneurysm rupture and treatment and to evaluate the risk factors for impaired outcome.METHODSIn a retrospective clinical follow-up study, data were collected from 620 consecutive patients who had been treated for ruptured PCoA aneurysms at a single center between 1980 and 2014. The follow-up was a minimum of 1 year after treatment or until death.RESULTSOf the 620 patients, 83% were treated with microsurgical clipping, 8% with endovascular coiling, 2% with the two procedures combined, 1% with indirect surgical methods, and 6% with conservative methods. The most common procedural complications were treatment-related brain infarctions (15%). The occurrence of artery occlusions (10% microsurgical, 8% endovascular) was higher than expected. Most patients made a good recovery at 1 year after aneurysmal subarachnoid hemorrhage (modified Rankin Scale [mRS] score 0–2: 386 patients [62%]). A fairly small proportion of patients were left severely disabled (mRS score 4–5: 27 patients [4%]). Among all patients, 20% died during the 1st year. Independent risk factors for an unfavorable outcome, according to the multivariable analysis, were poor preoperative clinical condition, intracerebral or subdural hematoma due to aneurysm rupture, age over 65 years, artery occlusion on postoperative angiography, occlusive treatment–related ischemia, delayed cerebral vasospasm, and hydrocephalus requiring a shunt.CONCLUSIONSEven though most patients made a good recovery after PCoA aneurysm rupture and treatment during the 1st year, the occlusive treatment–related complications were higher than expected and caused morbidity even among initially good-grade patients. Occlusive treatment of ruptured PCoA aneurysms seems to be a high-risk procedure, even in a high-volume neurovascular center.

BACKGROUND: Mirror distal anterior cerebral artery aneurysms (DACAAs) are a rare finding in patients with subarachnoid hemorrhage, with only a few cases reported. CASE DESCRIPTION: A 40-year-old man was admitted for sudden-onset headache, nausea and vomiting, and transient right arm hypoesthesia. Computed tomography scan showed a subarachnoid hemorrhage with intracerebral hemorrhage within the interhemispheric fissure, but computed tomography angiography failed to identify any aneurysms. Subsequent digital subtraction angiography with three-dimensional reconstructions revealed 1.5-mm-diameter mirror DACAAs on the A3 segments. However, the definite rupture site remained unidentifiable. After interdisciplinary consultation, endovascular treatment was favored, and complete occlusion of both DACAAs was achieved by coiling without stent placement. During coiling of the right DACAA, a thrombus in the right callosomarginal artery formed, and treatment with abciximab (ReoPro) was initiated to dissolve the thrombus. After treatment, the patient presented with right leg paresis; however, computed tomography did not show any ischemia, intracerebral hemorrhage increase, or vasospasm. Over the following days, the leg paresis improved, and the patient achieved increased mobilization. He was transferred for further rehabilitation 16 days after hemorrhage. The leg paresis had recovered to a grade 3/5. CONCLUSIONS: Rapid identification of the rupture site in patients with subarachnoid hemorrhage and multiple aneurysms is crucial for initiating optimal treatment. In patients with mirror aneurysms in close proximity to each other, this is not easily accomplished, complicating treatment decisions. Although clipping has been the standard for DACAA occlusion, coiling should be taken into consideration as a viable alternative.

Neurosurgeons are vulnerable to additional noise in their natural operating environment. Noise exposure is associated with reduced cognitive function, inability to concentrate, and nervousness. Mediation music provides an opportunity to create a calmer environment which may reduce stress during surgery. A pilot study was performed to find a suitable task, meditation music of surgeon’s choice, and operation noise and to reach a certain level of training. For the main experiment, two neurosurgeons with different microsurgical experience used real operation noise and meditation music with delta waves as mediating music. Each surgeon performed 10 training bypasses (five with noise and five with music) with 16 stitches in each bypass. The total time to complete 16 stitches, a number of unachieved movements (N.U.Ms), length of thread consumed, and distribution of the stitches were quantified from the recorded videos and compared in both groups. A N.U.Ms were significantly reduced from 109 ± 38 with operation room (OR) noise to 38 ± 13 (p

Background The microscope is the standard tool for microneurosurgery worldwide. However, the reduced illumination of the surgical field with the use of a conventional microscope during surgeries of deeply located pathologies remains unaddressed. Accordingly, different exoscope systems have recently been introduced in clinical practice. Here, we report our initial experience with the digital 2-dimensional Synaptive Modus V exoscope system in spinal and cranial surgery. Methods During a 2-week period between 27 September to 11 October 2018, we used the Synaptive Modus V exoscope system and performed eight neurosurgical procedures including spine (n = 4) and cranial procedures (n = 4). Visual quality, depth perception, complications, switching to microscope comfort level of the surgeon, and learning curve during surgery were evaluated. Results A total of eight procedures were performed, namely, vestibular schwannoma (n = 1), skull base meningioma (n = 1), olfactory groove meningioma (n = 1), tentorial meningioma (n = 1), anterior cervical discectomy (n = 1), cervical laminectomy (n = 1), and lumbar disc herniation (n = 2). The overall results were comparable to the operative microscope with better visual quality and greater comfort for the surgeon. Conclusion The Synaptive Modus V system is a safe tool to perform common spinal surgeries and intracranial tumor resection. Image quality is better than a microscope but with slightly less depth perception. Vigorous training in the laboratory may be helpful before clinical use. Electronic supplementary material The online version of this article (10.1007/s00701-019-03953-x) contains supplementary material, which is available to authorized users.

Outcome and treatment-associated morbidity analysis of trigone meningioma surgery. We retrospectively assessed 27 neurosurgically treated patients (median age 63 years, range 15–84) between 1999 and 2019. The median preoperative Karnofsky Performance Scale (KPS) was 80 (range 20–100), and the majority (78%) suffered from tumour-specific symptoms. The most frequent symptoms were aphasia (n = 6), visual field deficits (n = 5), and increased intracranial pressure (n = 5). The median tumour volume was 11.2 cm3 (range 3.9–220.5). The most common approaches were the transtemporal (n = 17) and transparietal routes (n = 5). At last follow-up (median follow-up 35 months, range 3–127), the median KPS was 90 (range 30–100); eleven (42%) patients had improved, nine (35%) were unchanged, six (23%) had worsened, and one was lost to follow-up. One year after surgery, 18/21 (86%) patients had retained an activity level similar or improved compared with preoperatively. No surgery-related mortality was recorded. Postoperative new neurological deficits were seen in 13 (48%) patients; eight suffered from permanent, most commonly motor deficits (n = 4), and five of transient deficits. Permanent new motor deficits improved in the majority of affected patients (3/4) over time. New deficits were more often seen for transtemporal (8/17) than transparietal approaches (1/5). Patients with postoperative permanent new deficits had a significantly worse KPS at last follow-up (p < 0.001). The transtemporal and transparietal approaches provide good access, but the latter might provide for a better risk profile. Patients show favourable outcome, but there is a considerable risk for new neurological deficits. This must be taken into consideration for oligosymptomatic patients.

Background Previous studies have consistently demonstrated gaze behaviour differences related to expertise during various surgical procedures. In micro-neurosurgery, however, there is a lack of evidence of empirically demonstrated individual differences associated with visual attention. It is unknown exactly how neurosurgeons see a stereoscopic magnified view in the context of micro-neurosurgery and what this implies for medical training. Method We report on an investigation of the eye movement patterns in micro-neurosurgery using a state-of-the-art eye tracker. We studied the eye movements of nine neurosurgeons while performing cutting and suturing tasks under a surgical microscope. Eye-movement characteristics, such as fixation (focus level) and saccade (visual search pattern), were analysed. Results The results show a strong relationship between the level of microsurgical skill and the gaze pattern, whereas more expertise is associated with greater eye control, stability, and focusing in eye behaviour. For example, in the cutting task, well-trained surgeons increased their fixation durations on the operating field twice as much as the novices (expert, 848 ms; novice, 402 ms). Conclusions Maintaining steady visual attention on the target (fixation), as well as being able to quickly make eye jumps from one target to another (saccades) are two important elements for the success of neurosurgery. The captured gaze patterns can be used to improve medical education, as part of an assessment system or in a gaze-training application.

Recently, the use of digital exoscopes has been increasingly promoted as an alternative to microscopes. The aim of this study is to compare experimental bypass quality in both visualization methods.This study used two hundred 1-mm chicken wing vessels, which were used for either exoscopic or microscopic (100 samples each) bypass procedures. All procedures were recorded between July 2018 and September 2018. The bypass quality was evaluated according to our published practical scale (time, stitch distribution, intima-intima attachment, and orifice size).Both methods are effective in doing bypass suturing (practical scale score was good, 86% vs. 85%; P = 0.84). There were no significant differences regarding intima-intima attachment (P = 0.26) and orifice size (P = 0.25). However, suturing time (P0.001) was less using the microscope, whereas stitch distribution (P = 0.001) was better using the exoscope. Different suturing techniques (interrupted vs. continuous) had overall comparable results (P = 0.55).Both methods produced equally satisfactory results in experimental bypass procedures. The exoscope has the potential for better 3-dimensional visualization and sharing the surgeon's view with others for teaching purposes.

Resection of brain arteriovenous malformation (AVM) is challenging, particularly if the feeder arteries and draining vein are not directly visible on the surface. Indocyanine green video angiography can assist in detection of the connecting point of the draining vein with the superficial vein and can thus localize the cortical entry point for AVM resection. Here, we present a case of a 27-year-old man with headache. Computed tomography scan showed right occipital atypical bleeding. Computed tomography angiography and digital subtraction angiography confirmed the cortical AVM fed by the posterior cerebral artery branches. We decided on surgical treatment because the small posterior cerebral artery feeders were not easily accessible for endovascular treatment. We used an OPMI PENTERO 900 microscope to perform microsurgical resection of AVM. We present an illustrative video showing the surgical approach, microsurgical anatomy, and technical aspects of the utility of video indocyanine angiography (video-ICG) in deep cortical small AVM surgery. Video-ICG assisted detection of the cortical arterialized draining vein that was anastomosed with a sprawled superficial vein. This enabled a customized approach for the AVM resection ( Video 1 ). Postsurgical video-ICG showed normalized flow in the superficial vein supporting the complete resection of AVM. ICG is potentially helpful for detecting the cortical entry point of a deep draining vein with a sprawled superficial vein. ICG should be used as an adjunct to better understand the microvascular anatomy that may aid decision making during AVM surgery.

Objective Flow diversion is a popular technique used to treat ordinary small, as well as complex internal carotid artery (ICA) aneurysms. We describe aneurysm occlusion rates, complications and patient outcomes in patients with ICA aneurysms treated with flow diverter stents. Patients and methods We identified all consecutive patients with ICA aneurysms that were treated with flow diverter stents between 2014 and 2019 at our institution. We divided the aneurysms into two anatomic subgroups (cavernous and supraclinoid segments). All the imaging studies and medical records were reviewed for relevant features in relation to aneurysms, complications and patient outcomes. Results A total of 62 patients with 76 ICA aneurysms (72 unruptured; 4 ruptured) were treated with 70 flow diversion procedures, including six re-treatments. Complete aneurysm occlusion was achieved in 61 % of patients at 6-month follow-up (cavernous 69 %, supraclinoid 58 %), and in 69 % at the latest follow-up (mean of 18 months). Postprocedural intracranial ischemia or hemorrhage was seen in 24 % of patients, including two aneurysm ruptures after flow diversion, and related major long-term functional decline or mortality was seen in 6% of patients. Preprocedural dysfunction of extraocular muscles or vision disturbance improved moderately at best (40–60 %). At the latest follow-up, 54 patients (87 %) were functionally independent (mRS ≤2). Conclusion Flow diversion for cavernous and supraclinoid ICA aneurysms demonstrated acceptable results, but complex aneurysm features cause uncertainty in predicting aneurysm occlusion probability. Patients should be informed of the non-negligible rate of complications, and of only moderate improvement rate of cranial nerve dysfunctions.

Aneurysmal subarachnoid hemorrhage (aSAH) is a complex and potentially deadly disease. Neurosurgical clipping or endovascular coiling can successfully obliterate ruptured aneurysms in almost every case. However, despite successful interventions, the clinical outcomes of aSAH patients are often poor. The reasons for poor outcomes are numerous, including cerebral vasospasm (CVS), post-hemorrhagic hydrocephalus, systemic infections and delayed cerebral ischemia. Although CVS with subsequent cerebral ischemia is one of the main contributors to brain damage after aSAH, little is known about the underlying molecular mechanisms of brain damage. This review emphasizes the importance of pharmacological interventions targeting high mobility group box 1 (HMGB1)-mediated brain damage after subarachnoid hemorrhage (SAH) and CVS. We searched Pubmed, Ovid medline and Scopus for “subarachnoid hemorrhage” in combination with “HMGB1”. Based on these criteria, a total of 31 articles were retrieved. After excluding duplicates and selecting the relevant references from the retrieved articles, eight publications were selected for the review of the pharmacological interventions targeting HMGB1 in SAH. Damaged central nervous system cells release damage-associated molecular pattern molecules (DAMPs) that are important for initiating, driving and sustaining the inflammatory response following an aSAH. The discussed evidence suggested that HMGB1, an important DAMP, contributes to brain damage during early brain injury and also to the development of CVS during the late phase. Different pharmacological interventions employing natural compounds with HMGB1-antagonizing activity, antibody targeting of HMGB1 or scavenging HMGB1 by soluble receptors for advanced glycation end products (sRAGE), have been shown to dampen the inflammation mediated brain damage and protect against CVS. The experimental data suggest that HMGB1 inhibition is a promising strategy to reduce aSAH-related brain damage and CVS. Clinical studies are needed to validate these findings that may lead to the development of potential treatment options that are much needed in aSAH.

Prior to the routine use of vertebral angiography, posterior fossa AVMs were usually found unexpectedly during the evacuation of posterior fossa hematomas [1]. In 1932 (May 5th), Olivecrona had reported their first successful radical removal of a left cerebellar AVM in a 37-year-old male who was misdiagnosed of having a posterior fossa tumor. After an 8-h-long marathon surgery under local anesthesia and with a blood transfusion of 2000 ml, the AVM was removed. The postoperative course was uneventful and the patient left the hospital 3 months later [2]. As vertebral angiography became more widely used, the preoperative diagnosis of posterior fossa AVMs became possible. Even so, at that time, neurosurgeons thought that it was possible to operate on small-to-moderate-sized AVMs in silent areas of the brain but were reluctant to touch AVMs in nonsilent areas [2], including the more demanding posterior fossa. Neurosurgeons were, however, disappointed that only very few AVMs could be removed entirely without great risk, which led to the development of other, ineffectual techniques, such as vertebral artery or feeder ligation [1].

Posterior communicating artery (PcomA) aneurysms are frequently encountered, but there are few publications on their morphology. A growing number of aneurysms are incidental findings, which makes evaluation of rupture risk important. Our goal was to identify morphological features and anatomical variants associated with PComA aneurysms and to assess parameters related to rupture. We studied CT angiographies of 391 consecutive patients treated between 2000 and 2014 at a single institution. We determined clinically important morphological parameters and performed univariate and multivariate analysis. There were a total of 413 PComA aneurysms: 258 (62%) were ruptured and 155 (38%) unruptured. Ruptured PComA aneurysms had the potential to cause severe bleeding with IVH and/or temporal ICH (n = 170, 66% of ruptured). The main types of PComA origin were classified as follows: (1) separate (32%), (2) side by side (21%) and (3) a joint neck with the aneurysm (6%). After the multivariate logistic regression, the morphological parameters related to PComA aneurysm rupture were an irregular aneurysm dome, neck diameter, and aspect ratio > 1.5. The most marked morphological features of the PComA aneurysms were: saccular nature (99%), infero-posterior dome orientation (42%), infrequency of large or giant aneurysms (4%), narrow neck compared to the aneurysm size, PComA originating directly from the aneurysm neck or the dome (28%), and fetal or dominant PComA on the side of the aneurysm (35%). There were location-related parameters that were more strongly associated with PComA aneurysm rupture than aneurysm size: an irregular aneurysm dome, larger diameter of the aneurysm neck and aspect ratio > 1.5.

Object The object of this study was to describe the authors' institutional experience in the treatment of complex middle cerebral artery (MCA) aneurysms necessitating bypass and vessel sacrifice. Methods Cases in which patients with MCA aneurysms were treated with a combination of bypass and parent artery sacrifice were reviewed retrospectively. Results The authors identified 24 patients (mean age 46 years) who were treated with bypass and parent artery sacrifice. The aneurysms were located in the M1 segment in 7 patients, MCA bifurcation in 8, and more distally in 9. The mean aneurysm diameter was 30 mm (range 7–60 mm, median 26 mm). There were 8 saccular and 16 fusiform aneurysms. Twenty-one extracranial-intracranial and 4 intracranial-intracranial bypasses were performed. Partial or total trapping (only) of the parent artery was performed in 17 cases, trapping with resection of aneurysm in 3, and aneurysm clipping with sacrifice of an M2 branch in 4. The mean follow-up period was 27 months. The aneurysm obliteration rate was 100%. No recanalization of the aneurysms was detected during follow-up. There was 1 perioperative death (4% mortality rate) and 6 cerebrovascular accidents, causing permanent morbidity in 5 patients. The median modified Rankin Scale score of patients with an M1 aneurysm increased from 0 preoperatively to 2 at latest follow-up, while the score was unchanged in other patients. Most of the permanent deficits were associated with M1 aneurysms. Twenty-one patients (88%) had good outcome as defined by a Glasgow Outcome Scale score of 4 or 5. Conclusions Bypass in combination with parent vessel occlusion is a useful technique with acceptable frequencies of morbidity and mortality for complex MCA aneurysms when conventional surgical or endovascular techniques are not feasible. The location of the aneurysm should be considered when planning the type of bypass and the site of vessel occlusion. Flow alteration by partial trapping may be preferable to total trapping for the M1 aneurysms.

The retrosigmoid approach for vestibular schwannoma surgery has remained the standard approach by most neurosurgeons. Drilling the posterior wall of the internal auditory meatus (IAM) is an essential step in removing the intrameatal tumor. During IAM drilling, three anatomical structures can be encountered, including the posterior semicircular canal, vestibular aqueduct, and jugular bulb. Any of these can be injured during drilling, especially if the jugular bulb lies above the inferior edge of the IAM. Although IAM drilling is performed in most vestibular schwannoma surgeries, information on how to manage complications such as jugular bulb injury is lacking. Here we use an intraoperative video to demonstrate how to manage the inadvertent injury to the jugular bulb in order to avoid massive blood loss. We present a case of a 39-year-old woman with hearing loss, diagnosed with a cerebellopontine angle mass extending into the IAM. Surgery was required due to tumor progression. We used the retrosigmoid approach to access the tumor. During IAM drilling, the jugular bulb was injured. A thin layer of bone wax was applied under continuous suction. The margins of the wax were then gently compressed with a dissector; great care was taken to avoid pushing the wax into the jugular bulb. Excess bone wax was removed (video 1). A small diamond drill (2 mm) was used for further drilling. Our instructional video shows the surgical approach, microsurgical anatomy, and technical aspects of managing massive bleeding from jugular bulb injury. It should therefore be helpful for young neurosurgeons.

Background Classification of middle cerebral artery (MCA) aneurysms is sometimes difficult because the identification of the main MCA bifurcation, the key for accurate classification of MCA aneurysms, is inconsistent and somewhat subjective. Objective To use the meeting point of the M1 and M2 trunks as an objective, generally accepted, and angiographically evident hallmark for identification of MCA bifurcation and more accurate classification of MCA aneurysms. Methods We reviewed the computed tomographic angiography data of 1009 consecutive patients with 1309 MCA aneurysms. The M2 trunks were followed proximally until their meeting with the M1 trunk at the main MCA bifurcation. The aneurysms were classified according to their relative location: proximal, at, or distal to the MCA bifurcation. The M1 aneurysms were further subgrouped into M1 early cortical branch aneurysms and M1 lenticulostriate artery aneurysms, extending the classic 3-group classification of MCA aneurysms into a 4-group classification. Results The main MCA bifurcation was the most common location for MCA aneurysms, harboring 829 aneurysms (63%). The 406 M1 aneurysms comprised 242 M1 early cortical branch aneurysms (60%) and 164 M1 lenticulostriate artery aneurysms (40%). We found 106 MCA aneurysms (8%) at the origin of large early frontal branches simulating M2 trunks liable to be misclassified as MCA bifurcation aneurysms. Even though 51% of the 407 ruptured MCA aneurysms were associated with an intracerebral hematoma, this did not affect the classification. Conclusion Studying MCA angioarchitecture and applying the 4-group classification of MCA aneurysms is practical and facilitates the accurate classification of MCA aneurysms, helping to improve surgical outcome.

Aneurysms of the posterior cerebral artery (PCA) are uncommon. Because of their low incidence, only 5 series with more than 30 patient cases have been reported. The treatment of PCA aneurysms is challenging because of the high frequency of fusiform aneurysms and closeness to important neuroanatomic structures.A total of 121 patients with 135 PCA aneurysms were reviewed. The clinical and radiologic data, treatment strategies, and 1-year outcomes were analyzed. Patients with giant aneurysms, associated aneurysms, and aneurysms on arteriovenous malformation-feeding PCAs were considered as complex cases. Outcomes were categorized into 3 groups: good (modified Rankin Scale [mRS], score 0-1), moderate (mRS score, 2-4), and poor (mRS score, 5-6).There were 52 ruptured (39%) and 83 unruptured (61%) PCA aneurysms in 121 patients, with the following distribution: P1 (n = 53), P1/2 (n = 39), P2 (n = 28), and P3 (n = 15). The incidence of fusiform PCA aneurysms was high (24%). Microsurgical treatment was applied to 63 aneurysms and endovascular treatment to 19 aneurysms; 55 aneurysms were treated conservatively. The following treatment results were achieved: for patients with unruptured PCA aneurysms, n = 19; 12 good outcomes, 63%; 6 moderate, 31%; 1 poor, 1%; for patients with ruptured PCA aneurysms, n = 27; 10 good, 37%; 9 moderate, 33%; 8 poor, 30%; and for patients with complex neurovascular diseases and PCA aneurysms, n = 96; 42 good, 43%; 40 moderate, 42%; 14 poor, 15%.Aneurysms of the PCA are infrequent and often associated with other vascular diseases. Microsurgery and endovascular treatment are effective for the occlusion of PCA aneurysms. The preservation or reconstruction of the parent vessel is crucial for favorable treatment outcomes.

Background Anterior clinoidal meningiomas (ACMs) are a subgroup of meningiomas accounting for less than 10% of supratentorial meningiomas. Objective To assess the reliability and safeness of the lateral supraorbital approach (LSO) to remove ACMs. Methods Between September 1997 and October 2009, a total of 73 ACM patients were operated on at the Department of Neurosurgery, Helsinki University Central Hospital, by the senior author (J.H.). We retrospectively analyzed the clinical data, radiological findings, surgical treatment, histology, and outcome of patients, and discuss the operative technique. Results Seventy-three patients were operated on by applying the LSO approach. Apparently complete removal was achieved in 57 patients (78%). Anterior clinoidectomy was performed in 21 cases. Preexisting visual deficit improved in 11 of 39 patients and worsened in 4; 3 had de novo visual deficit. At 3 months after discharge, 60 (82%) patients had a good recovery, 9 (12%) patients were moderately disabled, 1 presented with severe disability, and 3 (4%) patients died of surgery-related causes. Sixteen (22%) patients had residual tumors, 6 of which required reoperation. During the median follow-up of 36 months (range, 3-146), tumor recurred in 3 patients: 2 were followed-up and 1 was reoperated on. Conclusion ACMs can be removed via the LSO approach with relatively low morbidity and mortality. Anterior clinoidectomy is required only in selected cases, and we prefer the intradural approach during the LSO approach. High-power coagulation should be avoided in proximity of the optic nerve.

Cavernomas of the temporal lobe occur in 10–20% of patients with cerebral cavernomas. They frequently cause epileptic seizures, some of which tend to become refractory to medical therapy. Surgical removal of safely achievable symptomatic lesions has been frequently consistent with good long-term outcome. In the present study, a postoperative outcome is assessed. Of our 360 consecutive patients with cerebral cavernomas, 53 (15%) had a single cavernoma in the temporal lobe. Forty-nine patients were treated surgically and were included in the study. All data were analyzed retrospectively. The cavernomas were allocated into three groups based on the temporal lobe site: medial, anterolateral, and posterolateral. To collect follow-up data, all available patients were interviewed by phone. Seizure outcome was assessed using the Engel classification and general outcome using the Glasgow Outcome Scale (GOS). Patients’ median age at presentation was 37 (range, 7–64) years, with a female/male ratio of 2.5:1. Epileptic seizures occurred in 40 patients (82%). Median duration of seizures preoperatively was 3 (range, 0.1–23) years. In addition, four patients (10%) had memory disorder. Three patients without history of seizures (6%) complained of headache and two (4%) had memory problems. Three patients (6%) had an incidental cavernoma. Hemorrhage occurred in nine patients (18%) preoperatively. Median postoperative follow-up time was 6 (range, 0.2–26) years. Favorable seizure outcome (Engel class I and II) was registered in 35 patients (90%). Ten patients (25%) who had only a single seizure before surgery were seizure free during postoperative follow-up. Good general outcome (GOS, 4.5) was detected in 46 patients (96%). Two patients (4%) developed a new mild memory deficit after surgery, and in two patients existing memory deficits worsened. Microsurgical removal of temporal lobe cavernomas is a safe and effective method to improve seizure outcome in patients with medically intractable epilepsy and to prevent deterioration caused by hemorrhage.

Objective Anterior choroid artery aneurysms (AChAAs) constitute 2%-5% of all intracranial aneurysms. They are usually small, thin walled with one or several arteries originating at their base, and often associated with multiple aneurysms. In this article, we review the practical microsurgical anatomy, the preoperative imaging, surgical planning, and the microneurosurgical steps in the dissection and the clipping of AChAAs. Methods This review, and the whole series on intracranial aneurysms (IAs), are mainly based on the personal microneurosurgical experience of the senior author (J.H.) in two Finnish centers (Helsinki and Kuopio) that serve, without patient selection, the catchment area in Southern and Eastern Finland. Results These two centers have treated more than 10,000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 IAs, 831 patients (28%) had altogether 980 internal carotid artery (ICA) aneurysms, of whom 95 patients had 99 (2%) AChAAs. Ruptured AChAAs, found in 39 patients (41%), with median size of 6 mm (range = 2-19 mm), were associated with intracerebral hematoma (ICH) in only 1 (3%) patient. Multiple aneurysms were seen in 58 (61%) patients. Conclusions The main difficulty in microneurosurgical management of AChAAs is to preserve flow in the anterior choroid artery originating at the base and often attached to the aneurysm dome. This necessitates perfect surgical strategy based on preoperative knowledge of 3 dimensional angioarchitecture and proper orientation during the microsurgical dissection.

We report two cases of operative intervention that was beneficial in the treatment of delayed symptomatic radionecrotic masses that had developed following stereotactic radiosurgery (SRS) using the gamma knife (GK) for the treatment of cerebral arteriovenous malformations (AVM). Case 1 involved a small craniotomy for decompression of a large cerebral multiloculated cyst, which had become symptomatic 84 months following gamma knife treatment for a left frontal lobe AVM. Case 2 involved surgical excision of an occipital radionecrotic mass 72 months following GK treatment for an occipital AVM. This patient had suffered from longstanding symptomatic cerebral oedema, which on occasions had become life threatening. Case 2 is also the first report of a radionecrotic mass occurring post-SRS for an AVM, which conversely appeared to demonstrate increased uptake on single photon emission computed tomography (SPECT) scan. The first literature review of such delayed symptomatic radionecrotic lesions is presented. There appears to be a late onset of symptoms (average 55 months, range 12–111 months) associated with such radionecrosis. Drainage of such cysts or excision of the mass lesion appears to be consistently beneficial to the patients and appears to be uncomplicated. We recommend early surgical intervention for such delayed symptomatic radionecrotic masses that do not resolve following non-operative management. We also recommend caution in interpretation of SPECT scan results when attempting to differentiate radionecrosis from neoplasia.

Background Aneurysms originating from the A2 segment of ACA and its frontobasal branches are rare, forming less than 1% of all IAs. There are only few reports on management of A2As. In this article, we review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of A2As. Methods This review, and the whole series on IAs, is mainly based on the personal microneurosurgical experience of the senior author (JH) in two Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland. Results These two centers have treated more than 10000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients and 4253 IAs, there were 35 patients carrying 35 A2As, forming 1% of all patients with IAs, 0.8% of all IAs, and 3% of all ACA aneurysms. Twenty-one (60%) patients presented with ruptured A2As with ICH in 11 (52%) and IVH in 7 (33%). Nineteen patients (54%) had multiple aneurysms. Conclusions A2As are often small, even when ruptured, with relatively wide base, and they are frequently associated with ICHs of IVHs. Our data suggest that A2As rupture at smaller size than IAs in general. The challenge is to select appropriate approach, locate the aneurysm deep inside the interhemispheric fissure, and to clip the neck adequately without obstructing branching arteries at the base. Unruptured A2As also need microneurosurgical clipping even when they are small.

Background Aneurysms originating from the A3 segment of anterior cerebral artery (A3A) form about 5% of all IAs. They are the most common among distal anterior cerebral artery aneurysms. There are relatively few reports on management of A3As. In this article, we review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of A3As. Methods This review, and the whole series on IAs, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland. Results These 2 centers have treated more than 10000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients and 4253 IAs, there were 163 patients carrying 174 A3As, forming 5% of all patients with IAs, 4% of all IAs, and 15% of all ACA aneurysms. Ninety-seven (60%) patients presented with ruptured A3As with ICH in 27 (28%) and IVH in 26 (27%). Ninety-four (58%) patients had multiple aneurysms. Conclusions Aneurysms of A3 segment of ACA are often small, even when ruptured, with relatively wide base, and they are frequently associated with ICHs of IVHs. Our data suggest that A3As rupture at smaller size than IAs in general. The challenge is to select appropriate approach, to locate the aneurysm deep inside the interhemispheric fissure, and to clip the neck adequately without obstructing branching arteries at the base. Unruptured A3As also need microneurosurgical clipping even when they are small.

OBJECTIVE: Distal anterior cerebral artery (DACA) aneurysms have special anatomic features such as small size, broad base with originating branches, association with anterior cerebral artery (ACA) anomalies, and multiple aneurysms. Our aim is to evaluate incidences of these findings from pretreatment angiograms to help both microsurgical and endovascular treatment planning. METHODS: We performed detailed angiographic analysis of 101 consecutive patients diagnosed with DACA aneurysms from 1998 to 2007 in the Department of Neurosurgery at the Helsinki University Central Hospital in Helsinki, Finland. All patients underwent either digital subtraction angiography (n = 39) or computed tomographic angiography (n = 62). RESULTS: Of the 101 patients, 50 patients (50%) had multiple aneurysms, 7 patients (7%) had multiple DACA aneurysms, and 1 patient (1%) had an associated arteriovenous malformation. The 108 DACA aneurysms were found in seven different locations: frontobasal branches (n = 2); A2 segment (n = 5); A3 segment inferior to genu of corpus callosum (n = 19), anterior to genu of corpus callosum (n = 70), and superior to genu of corpus callosum (n = 1); A4 or A5 segments (n = 7); and distal branches (n = 4). Mean sizes were 7.4 mm (range, 2-35 mm) and 4.2 mm (range, 1-9 mm) for the 67 ruptured and 41 unruptured aneurysms, respectively. A broad base, wider than the parent artery, was seen in 68% of patients, and 94% of patients had a branch origin at the base. The neck-to-dome ratio was 1:1 in 25% of patients. Anomalies of the ACA were seen in 23 patients (23%): azygos ACA in 4 patients (4%), bihemispheric ACA in 15 patients (15%), and triplication of ACA in 4 patients (4%). CONCLUSION: The special neurovascular features and frequent ACA anomalies, best identified from computed tomographic angiography or rotational digital subtraction angiography, must be taken into account when planning occlusive treatment of DACA aneurysms.

Background Anterior communicating artery complex is the most frequent site of intracranial aneurysms in most reported series. Anterior communicating artery aneurysms are the most complex aneurysms of the anterior circulation due to the angioarchitecture and flow dynamics of the ACoA region, frequent anatomical variations, deep interhemispheric location, and danger of severing the perforators with ensuing neurologic deficits. The authors review the practical microsurgical anatomy, importance of preoperative imaging in surgical planning, and microneurosurgical steps in dissection and clipping of ACoAAs. Methods This review, and the whole series on intracranial aneurysms, are mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland. Results These 2 centers have treated more than 10 000 patients with aneurysm since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 aneurysms, 1145 patients (38%) had altogether 1179 ACA aneurysms; of them, 898 patients harbored 921 (78%) ACoAAs. In this series, 715 patients (80%) presented with ruptured ACoAAs with the median diameter of 7 mm. Giant ACoAAs were present in 15 (2%), whereas only 3 (0.3%) were classified as fusiform. Conclusions Anterior communicating artery aneurysms present frequently with SAH at small size. Furthermore, unruptured ACoAAs may have increased risk of rupture regardless of size, also as an associated aneurysm, and require treatment. The aim in microneurosurgical management of an ACoAA is total occlusion of the aneurysm sac with preservation of flow in all branching and perforating arteries. This demanding task necessitates perfect surgical strategy based on review of the 3D angioarchitecture and abnormalities of the patient's ACoA complex with its ACoAA and to orientate accordingly during the microsurgical dissection. The surgical trajectory should provide optimal visualization of the ACoA complex without massive brain retraction. Precise dissection in the 3D anatomy of the ACoA complex and perforators requires not only experience and skill but patience to work the dome and base under repeated protection of temporary clips and pilot clips. This is particularly important with the complex, large, and giant aneurysms.

Objective This study presents the combined experience of two Finnish neurosurgical centers in the treatment of 501 consecutive patients with distal anterior cerebral artery (DACA) aneurysms. Our aim was to compare treatment outcomes of these lesions with intracranial aneurysms in general and to identify factors predicting the outcome. Methods We analyzed the clinical and radiological data of all 501 patients and focused on the 427 patients treated between 1980 and 2005, the era of microsurgery and computed tomographic imaging. No patients were lost to follow-up. We compared treatment and outcome of ruptured DACA aneurysms (n = 277) with all consecutive ruptured aneurysms from the Kuopio Cerebral Aneurysm Database (n = 2243) and used multivariate analysis to identify factors predicting 1-year outcome. Results DACA aneurysms accounted for 6% of all intracranial aneurysms. They were smaller (median, 6 versus 8 mm), more frequently associated with multiple aneurysms (35 versus 18%), and presented more often with intracerebral hematomas (53 versus 26%) than ruptured aneurysms in general. Their microsurgical treatment showed the same complication rates (treatment morbidity, 15%; treatment mortality, 0.4%) as for other ruptured aneurysms. At 1 year after subarachnoid hemorrhage, they had similar favorable outcome (Glasgow Coma Scale score >or=4) as other ruptured aneurysms (74 versus 69%), but their mortality rate was lower (13 versus 24%). Factors predicting unfavorable outcome for ruptured DACA aneurysms were advanced age, Hunt and Hess grade greater than or equal to III, rebleeding before treatment, intracerebral hematoma, intraventricular hemorrhage, and severe preoperative hydrocephalus. Conclusion Despite their specific features, with modern treatment methods, ruptured DACA aneurysms have the same favorable outcome and lower mortality at 1 year as ruptured aneurysms in general.

Background Distal middle cerebral artery aneurysms originate from branches of MCA distal to its main bifurcation or the peripheral branches. Distal middle cerebral artery aneurysms are the least frequently seen among the middle cerebral artery aneurysms. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MdistAs. Methods This review, and the whole series on intracranial aneurysms, are mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in Southern and Eastern Finland. Results These 2 centers have treated more than 10 000 aneurysm patients since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 aneurysms, 69 patients carrying altogether 78 MdistAs formed 5% of all MCA aneurysms. Among the 18 patients with ruptured MdistAs (23%), an ICH occurred in 9 (50%). Conclusions Distal middle cerebral artery aneurysms are rare. The microneurosurgical treatment of MdistAs is challenging. They are often difficult to localize during the operation, and lack of collateral circulation makes their occlusion more demanding. High rate of ICH and high tendency of rebleeding urge acute or emergency surgery in most of ruptured cases. Microneurosurgical clipping is the most effective treatment of MdistAs.

Background The M1As are located in the main trunk (M1) of the MCA, between the bifurcation of the ICA and the main bifurcation of M1. Proximal MCA aneurysms are often small and thin-walled, which makes their proper clipping tedious. There are few reports on their microsurgery. Methods This review, and the whole series on intracranial aneurysms, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without selection, the catchment area in the southern and eastern Finland. Results These 2 centers have treated more than 10 000 patients with aneurysm since 1953. We review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of M1As which form 7.4% of all intracranial and 14% of all MCA aneurysms in our patients. Conclusions Proximal MCA aneurysms are often wide-necked and intimately connected to an M1 branch at its origin on M1, features that favor exosurgery rather than endosurgery. The direction and course of the parent and branching arteries and the orientation of the fundus are the most important factors affecting the efficacy and safety of clipping.

BACKGROUND: Giant intracranial aneurysms (GIAs), which are defined as intracranial aneurysms (IAs) with a diameter of ≥25 mm, are most likely associated with the highest treatment costs of all IAs. However, the treatment costs of unruptured GIAs have so far not been reported. OBJECTIVE: To examine direct costs of endovascular and surgical treatment of unruptured GIAs. METHODS: We retrospectively examined 55 patients with unruptured GIAs treated surgically (37 patients) or endovascularly (18 patients) between April 2004 and March 2014. We analyzed the costs of all hospital stays, interventions, and imaging with a median follow-up of 46 months. RESULTS: There was no difference in the costs of hospital stay between surgical and endovascular treatment groups ($10,565 vs. $14,992; P = .37). Imaging costs were significantly higher in the surgical group than in the endovascular treatment group ($2890 vs. $1612; P < .01), as were the costs of the intervention room and personnel involved in the intervention ($5566 vs. $1520; P < .01). Implants used per patient were more expensive in the endovascular group than in the surgical treatment group ($20,885 vs. $167). The total direct treatment costs were higher in the endovascular group ($52,325) than in the surgical treatment group ($20,619; P < .01). Treatment costs were associated with the type of treatment and GIA location but not with patient age, sex, or GIA size. CONCLUSION: Endovascular GIA treatment produced higher direct costs than surgical GIA treatment mainly due to higher implant costs. Reducing endovascular implant costs may be the most effective tool to decrease direct costs of GIA treatment.

BACKGROUND: The Giant Intracranial Aneurysm Registry is a multicenter observational trial exclusively focusing on giant intracranial aneurysms (GIA). As no data exist on the interobserver variability in the radiological description of GIA, there is some uncertainty concerning the reliability of the GIA characteristics included in the registry. We have therefore designed a study to test the interobserver variability in the description of the specific GIA characteristics that are examined in the GIA registry. METHODS: Six different raters analyzed imaging of five GIA concerning GIA location, GIA size, GIA shape, GIA thrombosis, and the presence of perianeurysmal edema. Interobserver variability was examined using intraclass correlation and Fleiss' kappa analysis. RESULTS: The intraclass correlation coefficient was 0.99 (95 % CI 0.97-1.0) for the largest GIA diameter and 0.98 (95 % CI 0.94-1.0) for the largest GIA diameter in an axial imaging slice. We found perfect interobserver agreement (Fleiss' kappa 1.00)in the characterization of GIA location and the presence of perianeurysmal edema and almost perfect interobserver agreement for GIA thrombosis (Fleiss' kappa 0.86, 95 % CI 0.63-1.00). Only moderate interobserver agreement was found in the description of GIA shape (Fleiss' kappa 0.50, 95 % CI 0.27-0.73). CONCLUSIONS: While GIA size, location, thrombosis, and the presence of perianeurysmal edema showed excellent interobserver agreement, the description of GIA shape was achieved with only moderate agreement. Data on GIA shape in multicenter studies, like the GIA registry, should therefore be discussed with caution and potentially reassessed in a centralized fashion.

Background and Purpose— There is high case-fatality rate and loss of productive life-years related to aneurysmal subarachnoid hemorrhage (aSAH) but data on long-term survival of patients with aSAH are scarce. We aim to evaluate long-term excess mortality and related risk factors after an aSAH event. Methods— Survivors (n=3078) of aSAH who had survived for ≥1 year were reviewed for this retrospective follow-up study, which was conducted in the Department of Neurosurgery in Helsinki between 1980 and 2007. Follow-up started 1 year after the aSAH and continued until death or the end of 2012 (48 918 patient-years). Mortality and relative survival ratios were derived using a matched general population. Results— Survivors of aSAH after 20 years showed 17% excess mortality compared with the general population. Even young patients and patients with good recovery showed excess mortality. The highest excess mortality was among patients with multiple aneurysms, old age, poor preoperative clinical condition, conservative aneurysm treatment, and unfavorable clinical outcome at 1 year. Conclusions— Even after initially favorable recovery from an aSAH, survivors experience excess mortality in the long run in comparison to a matched general population. Cardiovascular disease at younger age and cerebrovascular events were overrepresented as causes of death, which indicates the importance of treatment of vascular risk factors. Young patients and patients with multiple aneurysms who are recovering from an aSAH should be followed-up and treated most actively.

Indocyanine green (ICG) is a fluorescent dye that has been used in medical diagnostics for almost six decades. It was first used clinically to evaluate liver function and later in cardiology and retinal angiography. The binding and spectral properties of ICG have enabled the development of new imaging systems for several surgical specialities. The introduction of new clinical applications has been especially rapid during the last few years. Here ICG fluorescence imaging described in publications during the last couple of years (January 2012–March 2014) is reviewed in the areas of plastic and reconstructive surgery, neurosurgery, cardiac, vascular, oncological, and hepatic surgery. In addition to clinical applications, some technical aspects and potential future developments of ICG-based fluorescent imaging are discussed.

Activation of peripheral mixed and cutaneous nerves activates a distributed cortical network including the second somatosensory cortex (SII) in the parietal operculum. SII activation has not been previously reported in the stimulation of the dorsal penile nerve (DPN). We recorded somatosensory evoked fields (SEFs) to DPN stimulation from 7 healthy adults with a 122-channel whole-scalp neuromagnetometer. Electrical pulses were applied once every 0.5 or 1.5 sec to the left and right DPN. For comparison, left and right median and tibial nerves were stimulated alternatingly at 1.5-sec intervals. DPN stimuli elicited weak, early responses in the vicinity of responses to tibial nerve stimulation in the primary somatosensory cortex. Strong later responses, peaking at 107-126 msec were evoked in the SII cortices of both hemispheres, with left-hemisphere dominance. In addition to tactile processing, SII could also contribute to mediating emotional effects of DPN stimuli.

Background The A5 segment aneurysms of the anterior cerebral artery are rare, approximately 0.5% of all intracranial aneurysms. They are small with a wide base located in the midline, with the domes mostly projecting upward or backward. Case description The authors describe a unique case of A5 segment aneurysm, with the dome embedded into the body of the corpus callosum. This 41-year-old female was admitted to the neurology department for possible multiple sclerosis investigation. Computed tomography angiogram (CTA) revealed a 4-mm right-sided pericallosal artery aneurysm, with rare configuration, which was caudally projected, embedded into the body of the corpus callosum. Considering the family history, patient underwent a prophylactic ligation surgery. The postoperative CT and CTA showed no complication and successful occlusion of the aneurysm with no ischemia or hemorrhage in the corpus callosum. Conclusion To the best of our knowledge, this is the first case of an aneurysm with this configuration. Our rare case of A5 segment aneurysm demonstrates the importance of planning of the surgery, choosing the appropriate approach, and knowing the detailed anatomy of the region, as well as the necessity of microsurgical clipping of small unruptured AdistAs.

Saccular aneurysms are frequently associated with arteriovenous malformations (AVMs) probably due to hemodynamic stresses exerted on an arterial wall. The incidence of such an association has been reported between 5.5% and 12% [1,2]. Most of these aneurysms are small or medium sized, giant aneurysms are very rare with only few cases published. Some of the associated aneurysms located on the arterial feeders of the AVM may decrease in size or even disappear completely after the AVM treatment [3]. However, intranidal aneurysms usually venous in origin, require treatment and when treated microsurgically, they should be removed together with the AVM nidus. If the intranidal aneurysm is giant, the complete removal of the AVM becomes even more challenging. Microscope integrated nearinfrared indocyanine green videoangiography (ICG) can be useful in such a situation mainly for intraoperative orientation. Here we present a case report of an AVM associated with giant intranidal aneurysm, which was treated successfully with the aid of intraoperative ICG.

Objective Aneurysms of the posterior cerebral artery (PCA) are rare, and therefore the individual and institutional experience of their microsurgical management is usually limited. In the present article, we describe our experience with the subtemporal approach to aneurysms arising from the PCA. Methods We reviewed 34 patients diagnosed with 37 PCA aneurysms, all microsurgically managed using the subtemporal approach between 1980 and 2012 at 2 Finnish neurosurgical centers (Helsinki and Kuopio). The following procedures were applied using the subtemporal approach: neck clipping (n = 24); proximal occlusion (n = 7); trapping (n = 2); wrapping (n = 1); aneurysmoraphy (n = 1); bypass bridging/trapping (n = 1); and a complex excimer laser-assisted nonocclusive anastomosis procedure (n = 1). Results Of these 34 patients, 16 presented with acute subarachnoid hemorrhage as a result of PCA aneurysm rupture, and 11 of the 16 had good outcome (modified Rankin scale 0–2) at 3 months The remaining 18 patients were treated microsurgically for incidentally diagnosed unruptured aneurysms, and 14 of the 18 had a good outcome. The most common serious complication in this series was an ipsilateral PCA infarction (12/34; 35%), mostly after proximal occlusion (n = 7) and/or trapping (n = 2). Conclusions The subtemporal approach is a suitable approach to aneurysms of the segments P1, P1–P2 junction, and P2, as well as the anterior P3 segment of the PCA. Using the subtemporal approach, the cerebrospinal fluid is released before retraction is necessary to prevent temporal lobe injury. The subtemporal approach can provide enough space for revascularization procedures. The most encountered complications were not related to the subtemporal approach but to the specific nature of PCA aneurysms.