Neuroform Atlas Stent for Treatment of Middle Cerebral Artery Aneurysms

Neurosurgery 89:102–108, 2021

Heterogeneous effect of endovascular aneurysm therapy has been observed across different anatomic locations. There is a paucity of data for stent-assisted coiling of middle cerebral artery (MCA) aneurysms.

OBJECTIVE: To present the results of the MCA aneurysmgroup from the Neuroform Atlas (Stryker Neurovascular) investigational device exemption (IDE) trial.

METHODS: The Atlas IDE trial is a prospective, multicenter, single-arm, open-label study of wide-neck aneurysms (neck ≥ 4 mm or dome-to-neck ratio < 2) in the anterior circulation treated with the Neuroform Atlas Stent and approved coils. Follow-up was obtained immediately postprocedure and 2, 6, and 12 mo postoperatively.We herein describe safety and efficacy outcomes, and functional independence of the subjects with aneurysms from all segments of MCA.

RESULTS: A total of 35 patients were included (27 MCA bifurcation, 5 M1, 3 M2). The mean aneurysm size was 6.0 ± 1.8 mm, and the mean neck was 4.4 ± 1.2 mm. Technical procedural success was achieved in all patients. A total of 26 patients had follow-up digital subtraction angiography available at 12mo, with 80.8% (21/26) having complete aneurysm occlusion. Twelve-month safety data were collected for 91.4% (32/35), 8.5% (3/35) had primary safety endpoint, all 3 major ischemic strokes. Mortality occurred in 2 patients beyond 30 d unrelated to procedure (1 gallbladder cancer and 1 fentanyl intoxication). At 1 yr, modified Rankin Score was 0 to 2 in 84.4% (27/32), 3 in 9.4%, and 3 patientswere missing. Approximately 5.7% (2/35) of patients were retreated at 12 mo.

CONCLUSION: Stent-assisted coiling with the Neuroform Atlas Stent is a viable alternative to clipping for selected MCA aneurysms. Complete aneurysm occlusion rates have improved compared to historical data. Proper case selection can lead to acceptable endovascular results.

Comparison Between CTA and Digital Subtraction Angiography in the Diagnosis of Ruptured Aneurysms

Computerized tomography angiography (CTA) is commonly used to diagnose ruptured cerebral aneurysms with sensitivities reported as high as 97% to 100%. Studies validating CTA accuracy in the setting of subarachnoid hemorrhage (SAH) are scarce and limited by small sample sizes.

OBJECTIVE: To evaluate the diagnostic accuracy of CTA in detecting intracranial aneurysms in the setting of SAH.

METHODS: A single-center, retrospective cohort of 643 patients was reviewed. A total of 401 patients were identified whose diagnostic workup included both CTA and confirmatory digital subtraction angiography (DSA). Aneurysms missed by CTA but diagnosed by DSA were further stratified by size and location.

RESULTS: Three hundred and thirty aneurysms were detected by CTA while DSA detected a total of 431 aneurysms. False positive CTA results were seen for 24 aneurysms. DSA identified 125 aneurysms that were missed by CTA and 83.2% of those were <5 mm in diameter. The sensitivity of CTA was 57.6% for aneurysms smaller than 5 mm in size, and 45% for aneurysms originating from the internal carotid artery. The overall sensitivity of CTA in the setting of SAH was 70.7%.

CONCLUSION: The accuracy of CTA in the diagnosis of ruptured intracranial aneurysm may be lower than previously reported. CTA has a low sensitivity for aneurysms less than 5 mm in size, in locations adjacent to bony structures, and for those arising from small caliber parent vessels. It is our recommendation that CTA should be used with caution when used alone in the diagnosis of ruptured intracranial aneurysms.

Spontaneous subarachnoid hemorrhage and negative initial vascular imaging—should further investigation depend upon the pattern of hemorrhage on the presenting CT?

Spontaneous subarachnoid hemorrhage and negative initial vascular imaging—should further investigation depend upon the pattern of hemorrhage on the presenting CT?

Acta Neurochir (2015) 157:1477–1484

Multiple investigations are usually performed in patients with spontaneous SAH who have negative initial angiography. This study aimed to evaluate the most appropriate use of additional imaging studies and how this may be influenced by the findings of the initial CT.

Methods A retrospective analysis was performed on a prospectively collected cohort of patients referred with spontaneous SAH and negative initial angiography. The patients were divided into four categories based upon the distribution of blood on the initial CT: perimesencephalic (pSAH), diffuse (dSAH), sulcal (sSAH) and CT negative (CSF positive for xanthochromia) (nCT-pLP). The number and nature of the subsequent imaging investigations were reviewed, and the results were correlated with the findings of the presenting CT.

Results One hundred fourteen patients were included in the study. Repeat imaging found five relevant abnormalities. Three cases of vasculitis were diagnosed on the first DSA following a negative CTA. A case of dissecting aneurysm was revealed on the third neurovascular study. A hemorrhagic spinal tumor presented with xanthochromia. No subsequent abnormality was found on the third DSA or MRI head. No case of pSAH had a subsequent positive finding if the initial CTA was negative.

Conclusions Certain patterns of SAH are associated with a low yield of abnormalities on repeat imaging if the initial angiography is normal. The authors believe that the pattern of hemorrhage on the presenting CT should be used to guide the most appropriate use of further imaging modalities and present a diagnostic algorithm for this purpose.

Contralateral Approach to Internal Carotid Artery Ophthalmic Segment Aneurysms: Angiographic Analysis and Surgical Results for 30 Patients

oftalmic ICA an

Neurosurgery. 77(1):104-112, July 2015

Contralateral aneurysm clipping can be applied to bilateral intracranial aneurysms of the anterior circulation and to selected aneurysms on the medial wall of the internal carotid artery (ICA).

OBJECTIVE: To identify anatomic and radiological parameters that would favor a contralateral microsurgical approach to ICA–ophthalmic segment (ICA-opht) aneurysms.

METHODS: For the period January 1957 to December 2012, we retrospectively analyzed 268 patients with ICA-opht aneurysms treated in our institution. Of these patients, 30 underwent a contralateral approach; 15 patients (50%) had multiple intracranial aneurysms, and 15 patients had a single aneurysm on the contralateral side of the craniotomy.

RESULTS: Thirty saccular aneurysms located on the contralateral ICA were treated. Six aneurysms (20%) were present in patients with a subarachnoid hemorrhage due to associated aneurysms, whereas 24 aneurysms (80%) had no history of bleeding. Contralateral aneurysms were smaller than 14 mm and showed no wall irregularities, calcifications, or secondary pouches. Projections of the aneurysms were superomedial (n = 23, 77%), medial (n = 4, 13%), and superior (n = 3, 10%). The median prechiasmatic distance was 5.7 mm (range, 3.4-8.7 mm), the median interoptic distance was 10.5 mm (range, 7.6-15.9 mm), and the median distance between both ICAs was 14.7 mm (range, 10.4-21.4 mm).

CONCLUSION: The contralateral approach for ICA-opht aneurysms remains a treatment option for intracranial aneurysms. Its feasibility depends on specific anatomic parameters related to the aneurysm itself and to the prechiasmatic distance, interoptic distance, and relationship of the ICA with the anterior clinoid process.

Integration of Indocyanine Green Videoangiography With Operative Microscope: Augmented Reality for Interactive Assessment of Vascular Structures and Blood Flow

Integration of Indocyanine Green Videoangiography With Operative Microscope

Operative Neurosurgery 11:252–258, 2015

Preservation of adequate blood flow and exclusion of flow from lesions are key concepts of vascular neurosurgery. Indocyanine green (ICG) fluorescence videoangiography is now widely used for the intraoperative assessment of vessel patency.

OBJECTIVE: Here, we present a proof-of-concept investigation of fluorescence angiography with augmented microscopy enhancement: real-time overlay of fluorescence videoangiography within the white light field of view of conventional operative microscopy.

METHODS: The femoral artery was exposed in 7 anesthetized rats. The dissection microscope was augmented to integrate real-time electronically processed near-infrared filtered images with conventional white light images seen through the standard oculars. This was accomplished by using an integrated organic light-emitting diode display to yield superimposition of white light and processed near-infrared images. ICG solution was injected into the jugular vein, and fluorescent femoral artery flow was observed.

RESULTS: Fluorescence angiography with augmented microscopy enhancement was able to detect ICG fluorescence in a small artery of interest. Fluorescence appeared as a bright-green signal in the ocular overlaid with the anatomic image and limited to the anatomic borders of the femoral artery and its branches. Surrounding anatomic structures were clearly visualized. Observation of ICG within the vessel lumens permitted visualization of the blood flow. Recorded video loops could be reviewed in an offline mode for more detailed assessment of the vasculature.

CONCLUSION: The overlay of fluorescence videoangiography within the field of view of the white light operative microscope allows real-time assessment of the blood flow within vessels during simultaneous surgical manipulation. This technique could improve intraoperative decision making during complex neurovascular procedures.

Indocyanine Green Angiography in the Surgical Management of Cerebral Arteriovenous Malformations

Indocyanine Green Angiography in the Surgical Management of Cerebral Arteriovenous Malformations

Operative Neurosurgery 10:246–251, 2014

Indocyanine green (ICG) angiography is commonly used to map the vascular configuration of cerebral arteriovenous malformations (AVMs) during resection.

OBJECTIVE: To determine whether ICG improves rates of resection and clinical outcomes.

METHODS: A retrospective chart review was done for all patients undergoing resection of an AVM by the senior author (R.F.S.) between 2007 and 2011. Operative reports, hospital records, and radiographic imaging were used to determine the use of ICG, the incidence of residual disease, and clinical outcomes.

RESULTS: A total of 130 cases (56 ICG, 74 non-ICG) were identified. Average AVM grade (2.2 vs 2.4) and size (2.7 vs 2.7 cm) were similar between the ICG and non-ICG groups, respectively. ICG was more often used when the AVM nidus was close to the cortical surface (71.4% vs 17.6%; P = .001) or lobar (82.1% vs 54.1%; P = .008). Eighteen patients (13.8%) were noted to have residual disease. Reoperation rates and change in modified Rankin Scale score were not different between the 2 groups (12.5% vs 14.9%, P = .8; 0.6 vs 0.4, P = .17). There were no ICG-attributable complications.

CONCLUSION: ICG videoangiography is a quick and safe method of intraoperatively mapping the angioarchitecture of superficial AVMs, but it is less helpful for deep-seated lesions. This modality alone does not improve the identification of residual disease or clinical outcomes. Surgeon experience with extensive study of preoperative vascular imaging is paramount to achieving acceptable clinical outcomes. Formal angiography remains the gold standard for the evaluation of AVM obliteration.

Intraoperative rerupture during surgical treatment of aneurysmal subarachnoid hemorrhage is not associated with an increased risk of vasospasm

aneurysm

J Neurosurg 120:409–414, 2014

Intraoperative rerupture during open surgical clipping of cerebral aneurysms in subarachnoid hemorrhage (SAH)is a relatively frequent and potentially catastrophic occurrence. Patients who suffer rerupture have been shown to have worse outcomes at discharge compared with those who do not have rerupture. Perioperative injury likely plays a large part in the clinical worsening of these patients. However, due to the increased vessel manipulation and repeat exposure to acute hemorrhage, it is possible that secondary injury from increased incidence of vasospasm also contributes. Identifying an increased rate of vasospasm in these patients would justify early aggressive treatment with measures to prevent delayed cerebral ischemia. The authors investigated whether patients who suffer intraoperative rerupture during surgical treatment of ruptured cerebral aneurysms are at increased risk of developing vasospasm.

Methods. Five hundred consecutive patients treated with open surgical clipping for SAH were reviewed, and clinical and imaging data were collected. Angiographic vasospasm was defined as vessel narrowing believed to be consistent with vasospasm on angiography. Symptomatic vasospasm was defined as angiographic vasospasm in the setting of a clinical change attributable to vasospasm. Rates of angiographic and symptomatic vasospasm among patients with and without intraoperative rerupture were compared.

Results. There were no significant differences between the groups with and without rupture with respect to age, sex, modified Fisher grade, history of hypertension, or smoking. The group with intraoperative rupture had more patients with Hunt and Hess Grade I. Angiographic vasospasm was noted in 279 (66%) of the 425 patients without rerupture compared with 49 (65%) of the 75 patients with rerupture (p = 1.0, Fisher’s exact test). Symptomatic vasospasm was noted in 154 (36%) of the 425 patients without rerupture, compared with 31 (41%) of the 75 patients with rerupture (p = 0.44, Fisher’s exact test). In multivariate analysis, higher modified Fisher grade was significantly predictive of vasospasm, whereas older age and male sex were protective.

Conclusions. This study found no significant influence of intraoperative rerupture during open surgical clipping on the rate of angiographic or symptomatic vasospasm. Brief exposure to acute hemorrhage and vessel manipulation associated with rerupture events did not affect the rate of vasospasm. Risk of vasospasm was related to increased modified Fisher grade, and inversely related to age and male sex. These results do not justify early, targeted vasospasm therapy in patients with intraoperative rerupture.

Anatomy and morphology of giant aneurysms

Giant aneurysms

Acta Neurochir (2014) 156:1–10

Giant intracranial aneurysms are rare and heterogeneous lesions with complex vascular anatomy. The aim of this retrospective study was to provide a comprehensive description of the anatomical features of giant aneurysms.

Methods We identified 125 patients with 129 giant aneurysms (≥25 mm) who were treated between 1987 and 2007 at the Department of Neurosurgery of Helsinki University Central Hospital (HUCH). All the imaging studies and medical records were reviewed for relevant information.

Results The distribution of the giant aneurysms among regions was as follows: internal carotid artery (ICA) 39 %, middle cerebral artery (MCA) 32 %, vertebrobasilar and posterior cerebral artery (VB-PCA) region 25 %, and anterior cerebral artery (ACA) including the anterior communicating artery 5%. The cavernous ICA segment (n =21, 16 %) and the MCA bifurcation (n =25, 19 %) were the most frequent specific locations. Half (n =11) of all fusiform aneurysms were found in the VB-PCA region. As many as 41 % of the giant MCA aneurysms were ruptured. Major anatomic variations were found in three (2 %) and multiple giant aneurysms in three (2 %) patients.Wall calcification was noted in 24 % and intraluminal thrombosis in 33 % of ruptured giant aneurysms (n =42).

Conclusions The majority of giant aneurysms are located in the ICA and MCA regions, while the ACA region is an exceptional site. The MCA region is the most common site for ruptured giant aneurysms. Associated anatomic variations and the multiplicity of giant aneurysms are a rare finding.

Modern intraoperative imaging modalities for the vascular neurosurgeon treating intracerebral hemorrhage

modern OR

Neurosurg Focus 34 (5):E2, 2013

This paper reviews the current intraoperative imaging tools that are available to assist neurosurgeons in the treatment of intracerebral hemorrhage (ICH). This review shares the authors’ experience with each modality and discusses the advantages, potential limitations, and disadvantages of each.

Surgery for ICH is directed at blood clot removal, reduction of intracranial pressure, and minimization of secondary damage associated with hematoma breakdown products. For effective occlusion and safe obliteration of vascular anomalies associated with ICH, vascular neurosurgeons today require a thorough understanding of the various intraoperative imaging modalities available for obtaining real-time information. Use of one or more of these modalities may improve the surgeon’s confidence during the procedure, the patient’s safety during surgery, and surgical outcome.

The modern techniques discussed include 1) indocyanine green–based video angiography, which provides realtime information based on high-quality images showing the residual filling of vascular pathological entities and the patency of blood vessels of any size in the surgical field; and 2) intraoperative angiography, which remains the gold standard intraoperative diagnostic test in the surgical management of cerebral aneurysms and arteriovenous malformations. Hybrid procedures, providing multimodality image-guided surgeries and combining endovascular with microsurgical strategies within the same surgical session, have become feasible and safe. Microdoppler is a safe, noninvasive, and reliable technique for evaluation of hemodynamics of vessels in the surgical field, with the advantage of ease of use. Intraoperative MRI provides an effective navigation tool for cavernoma surgery, in addition to assessing the extent of resection during the procedure. Intraoperative CT scanning has the advantage of very high sensitivity to acute bleeding, thereby assisting in the confirmation of the extent of hematoma evacuation and the extent of vascular anomaly resection. Intraoperative ultrasound aids navigation and evacuation assessment during intracerebral hematoma evacuation surgeries. It supports the concept of minimally invasive surgery and has undergone extensive development in recent years, with the quality of ultrasound imaging having improved considerably.

Image-guided therapy, combined with modern intraoperative imaging modalities, has changed the fundamentals of conventional vascular neurosurgery by presenting real-time visualization of both normal tissue and pathological entities. These imaging techniques are important adjuncts to the surgeon’s standard surgical armamentarium. Familiarity with these imaging modalities may help the surgeon complete procedures with improved safety, efficiency, and clinical outcome

Cerebral arterial fenestrations: a common phenomenon in unexplained subarachnoid haemorrhage

Cerebral arterial fenestrations- a common phenomenon in unexplained subarachnoid haemorrhage

Acta Neurochir (2013) 155:217–222

Fenestrations of intracranial arteries are variants resulting from incomplete fusion of vessels during development with unknown clinical significance. They are best visualised with 3D rotational angiography (3DRA).

Objective In a prospective consecutive series of patients with suspected aneurysms, 3DRA was performed to identify not only the potential bleeding source but also to assess the frequency and location of any fenestrations of intracranial arteries.

Methods In 287 consecutive patients with possible intracranial aneurysms (accidental discovery or previous history of SAH), 3DRAs were prospectively performed, and the location of subarachnoid haemorrhage was assessed by CT.

Results Of 174 patients presenting with SAH, 153 had saccular aneurysms, and in 21 cases (12.1 %), no source of bleeding was found. In 20 of these 21 patients with “unexplained SAH” (95.2 %) an arterial fenestration was detected in the neighbourhood of the clot. The incidence of fenestration in the 153 aneurysmal SAH patients was 22.9 %, and it was 23.3 % in 266 patients with intracranial aneurysms (113 accidental and 153 ruptured).

Conclusions Arterial fenestration was detected in 22.9 % of ruptured cerebral aneurysms, in contrast with 95.2 % in patients with unexplained SAH, the difference being statisctically significant (p<0.01). Fenestration is a developmental defect, a structural wall weakness possibly making the vessel prone to rupture. Its incidence of nearly 100 % may suggest a connection with idiopathic SAH. The presented data indicate that arterial fenestrations are generally overlooked, and they can be considered as one of the candidates for the source of idiopathic SAH.

Ruptured Intracranial Aneurysms With Small Basal Outpouching

Neurosurgery 71:994–1002, 2012

Recognizing an aneurysmal basal rupture using angiographic evaluation is crucial for optimal treatment.

OBJECTIVE: To evaluate the incidence of a small basal outpouching (the most common angiographic configuration suggesting a basal rupture), the incidence of a ruptured basal outpouching, and the results of surgical and endovascular treatments.

METHODS: The occurrence of small basal outpouchings was determined in the initial angiographic examinations of 471 patients with a ruptured aneurysm. Information was also obtained from patient charts, surgical and interventional reports, operative video records, and reviews of radiological investigations.

RESULTS: A small basal outpouching was identified in 41 (8.7%) of the 471 ruptured aneurysms. In the surgical series (n = 286), a basal rupture was identified in 8 (30.8%) of the 26 cases of a basal outpouching and successfully treated by aneurysm clip placement. In the endovascular series (n = 185), intraprocedural aneurysm rebleeding developed in 5 of the 15 patients (33.3%) with a basal outpouching, which was most commonly observed with anterior communicating artery aneurysms.

CONCLUSION: The current surgical series included a 9% incidence of ruptured intracranial aneurysms with a small basal outpouching, and a 31% incidence of these basal outpouchings being identified as the rupture point. The results also suggested that endovascular coiling of a basal outpouching carries a high risk of intraprocedural aneurysm rebleeding, whereas surgical clipping is safer and provides more protection against rebleeding of aneurysms with a basal rupture.

The intermediate trunk of the middle cerebral artery

J Neurosurg 116:1024–1034, 2012

(http://thejns.org/doi/abs/10.3171/2012.1.JNS111013)

The branching structure of the middle cerebral artery (MCA) remains a debated issue. In this study the authors aimed to describe this branching structure in detail.

Methods. Twenty-seven fresh, human brains (54 hemispheres) obtained from routine autopsies were used. The cerebral arteries were first filled with colored latex and contrast agent, followed by fixation with formaldehyde. All dissections were done under a microscope. During examination, the trunk structures of the MCA and their relations with cortical branches were demonstrated. Lateral radiographs of the same hemispheres were then obtained and comparisons were made. Angles between the MCA trunks were measured on 3D CT cerebral angiography images in 25 patients (50 hemispheres), and their correlations with the angles obtained in the cadaver brains were evaluated.

Results. A new classification was made in relation to the terminology of the intermediate trunk, which is still a subject of debate. The intermediate trunk was present in 61% of cadavers and originated from a superior trunk in 55% and from an inferior trunk in 45%. Cortical branches supplying the motor cortex (precentral, central, and postcentral arteries) significantly originated from the intermediate trunk, and the diameter of the intermediate trunk significantly increased when it originated from the superior trunk. In measurements of the angles between the superior and intermediate trunks, it was found that the intermediate trunk had significant dominance in supplying the motor cortex as the angle increased. The intermediate trunk was classified into 3 types based on the angle values and the distance to the bifurcation point as Group A (pseudotrifurcation type), Group B (proximal type), and Group C (distal type). Group A trunks were seemingly closer to the trifurcation structure that has been reported on in the literature and was seen in 15%. Group B trunks were the most common type (55%), and Group C trunks were characterized as the farthest from the bifurcation point. Group C trunks also had the smallest diameter and fewest cortical branches. Similarities were found between the angles in cadaver specimens and on 3D CT cerebral angiography images. Beyond the separation point of the MCA, trunk structures always included the superior trunk and inferior trunk, and sometimes the intermediate trunk.

Conclusions. Interrelations of these vascular structures and their influences on the cortical branches originating from them are clinically important. The information presented in this study will ensure reliable diagnostic approaches and safer surgical interventions, particularly with MCA selective angiography.

Contrast-Enhanced Magnetic Resonance Characteristics of Arteriovenous Malformations After Gamma Knife Radiosurgery: Predictors of Post-Angiographic Obliteration Hemorrhage

Neurosurgery 67:101-109, 2010 DOI: 10.1227/01.NEU.0000370601.17570.4

The reported cumulative risk of post-angiographic obliteration (post-AO) hemorrhage from arteriovenous malformations (AVMs) following gamma knife radiosurgery (GKRS) over 10 years is 2.2%.

OBJECTIVE: To identify the warning signs of post-AO hemorrhage by analyzing the characteristics of enhancement on contrast-enhanced MRI magnetic resonance imaging (MRI) of AVMs with post-AO hemorrhage.

METHODS:We performed a retrospective analysis of 121 patients whose AVMs were angiographically obliterated within 5 years of GKRS without hemorrhage and who received at least 1 contrast-enhanced MRI after GKRS (group 1), and 7 patients who experienced post- AO hemorrhage (group 2). We analyzed the enhancement persistence ratio (the percentage of AVMs with persisting enhancement on contrast-enhanced T1-weighted image after obliteration) and the change in size of the enhanced region over time in each patient.

RESULTS: The enhancement persistence ratio showed no significant difference between the 2 groups (89.4% vs 100% for groups 1 and 2, respectively; P = .401). While most cases in group 1 showed a tendency to decrease in size and gradually stabilize following GKRS, there were significantly more cases in group 2 with obvious increment of the enhanced regions within 1 year of angiographic obliteration compared with the previous measurement (4.96% vs 71.4% for groups 1 and 2, respectively; P < .0001).

CONCLUSION: Our results suggest that AVMs that show an increase in the size of the enhanced region within 1 year of angiographic obliteration should be followed up with caution for post-AO hemorrhage. Persisting enhancement itself is not positively associated with subsequent hemorrhage.

Preliminary Personal Experiences With the Application of Near-Infrared Indocyanine Green Videoangiography in Extracranial Vertebral Artery Surgery

INTRODUCTION:We evaluated the feasibility, usefulness, and limitations of near-infrared indocyanine green (ICG) videoangiography during procedures involving the extracranial vertebral artery (VA).

METHODS: Nine patients (2 women, 7 men; mean age, 55 years) were evaluated at 2 neurosurgical centers. Near-infrared ICG videoangiography was applied during transposition and rerouting of the first segment of VA (V1; n = 6) and during resection of neurinomas near the second (V2; n = 1) and third (V3; n = 2) segments of VA.

RESULTS: Early after ICG injection, V1 fluoresced homogenously. The fluorescence of V2 and V3 varied. Without extrinsic compression, these segments appeared as noncontiguous hot spots because the VA runs freely in a periosteal sheath surrounded by a venous plexus that attenuates the fluorescent light. Hot spots corresponded to areas where the artery neared the surface. With extrinsic compression, VA enhanced homogenously because it was pushed against the periosteal layer. During the late phase, the V1 signal was attenuated, whereas the venous plexus surrounding V2 and V3 enhanced homogeneously, thereby masking the VA itself. Near-infrared ICG videoangiography helped to confirm VA patency during transposition and rerouting but was not helpful during VA exposure because the periosteal sheath must already be exposed to detect the VA or its surrounding plexus. After exposure, videoangiography can help to determine the position of the VA within its periosteal sheath.

CONCLUSION: Videoangiography can be used to provide information about the patency of the VA and its location within the periosteal sheath to prevent injury during resection of tumor adherent to the periosteal sheath.

Risk of Retreatment for Aneurysm Recurrence or Residual After Initial Treatment By Endovascular Coiling

Neurosurgery: August 2009 – Volume 65 – Issue 2 – p 311-315

Endovascular treatment of intracranial aneurysms is less invasive than surgical repair but poses a higher risk for aneurysm recurrence, which may necessitate retreatment, thus adding to the long-term risk. Cerebrovascular neurosurgeons from 8 institutions in the United States and Puerto Rico collaborated to assess the risk of retreatment for residual or recurrent aneurysms after the initial endovascular coiling.

Data were prospectively recorded for 311 patients with coiled intracranial aneurysms who underwent 352 retreatment procedures after angiographic or clinical recurrence (hemorrhage after initial coiling). Results analyzed included procedural complications and procedure-related morbidity. Morbidity was classified as major (modified Rankin scale score > 3) or minor, and temporary (<30 days) or permanent (>30 days).

Retreatment mortality was 0.85% per procedure and 0.96% per patient. Treatment-related rates were 0.32% per patient (0.28% per procedure) for permanent or temporary major disability; 1.29% for permanent minor disability (1.14% per procedure); and 1.61% for temporary minor disability (1.42% per procedure). Total risk for death or permanent major disability was 1.28% per patient and 1.13% per procedure.

Retreatment poses a low risk for patients with recurrences of intracranial aneurysms after initial coiling; this risk is smaller than that posed by the initial endovascular therapy. The risk of disability associated with retreatment for aneurysm recurrence after coiling must be considered prospectively in the choice of treatment but with the recognition that its effects are low in the overall management risk.