Christian Dorfer

Prospective Comparison of Intraoperative Vascular Monitoring Technologies During Cerebral Aneurysm Surgery

BACKGROUND:Microscope integrated intraoperative near-infrared indocyanine green angiography (ICGA) provides assessment of the cerebral vasculature in the operating field. OBJECTIVE:To prospectively compare the value of ICGA-derived information during cerebral aneurysm surgery with data simultaneously generated from other intraoperative monitoring and vascular imaging techniques. METHODS:Data from 104 patients with 123 cerebral aneurysms who were operated on were prospectively recorded. Results of intraoperative vascular monitoring and descriptions of how this information influenced intraoperative decision making were analyzed. RESULTS:Clip repositioning was necessary in 30 of 123 aneurysms (24.4%) treated. Parent artery occlusion was documented by microvascular Doppler ultrasound in 4 aneurysms. ICGA disclosed parent artery stenoses not detected by sonography in 7 cases. Neuroendoscopy was used in 13 cases of midline aneurysms to confirm perforator patency after clipping, and disclosed aneurysm misclipping undetected by ICGA and digital subtraction angiography in 1 aneurysm. The information from DSA and ICGA corresponded in 120 of 123 aneurysms operated on (97.5 %). In 1 patient, ICGA underestimated a relevant parent artery stenosis detected by digital subtraction angiography. In 2 patients with relevant aneurysmal misclipping, digital subtraction angiography and ICGA led to conflicting results that could be clarified only when both methods were used and interpreted together. CONCLUSION:The intraoperative monitoring and vascular imaging methods compared were complementary rather than competitive in nature. None of the devices used were absolutely reliable when used as a stand-alone method. Correct intraoperative assessment of aneurysm occlusion, perforating artery patency, and parent artery reconstruction was possible in all patients when these techniques were used in combination.

Management of Residual and Recurrent Aneurysms After Initial Endovascular Treatment

BACKGROUND Coil instability possibly translating into higher delayed rebleeding rates remains a concern in the endovascular management of cerebral aneurysms. OBJECTIVE To report on 127 patients with endovascular aneurysmal remnants who underwent re-treatment over an 18 year period. METHODS Patients presenting with aneurysm residuals >20% of the original lesion, unstable neck remnants, aneurysmal regrowth, or new aneurysmal daughter sacs were treated by an individualized approach, using both endovascular and surgical techniques. RESULTS Seventy-five aneurysmal remnants (59.1%) were treated by further re-embolization. Standard coil embolization was used in 65 cases, stent-protected coiling in 9 cases, and balloon remodeled coiling in 1 case, respectively. Fifty-two (40.9%) aneurysmal remnants were treated surgically. Standard microsurgical clipping was used in 44 patients, parent artery occlusion or trapping under bypass protection in 5 cases, deliberate clipping of the basilar artery trunk in 2 cases, and aneurysm wrapping in one case, respectively. Mechanisms of aneurysm recurrence were coil compaction in 93 cases and regrowth in 34 cases. A single reembolization was sufficient to occlude 78.7% of recurrences from coil compaction, but only 14.3% of recurrences from aneurysm regrowth. CONCLUSION The individualized approach resulted in complete occlusion of 114 aneurysms (89.7%), with neck remnants and residual aneurysms detectable in 11 (8.7%) and 2 (1.6%) cases, respectively. Treatment morbidity was 11.9%, without significant differences between surgical (15.6%) and endovascular (9.3%) patients (P = .09). Recurrences from coil compaction were safely treated by re-embolization, whereas recurrences from aneurysmal regrowth may best be managed surgically when technically feasible.

Atypical teratoid rhabdoid tumor: improved long-term survival with an intensive multimodal therapy and delayed radiotherapy. The Medical University of Vienna Experience 1992-2012.

Atypical teratoid rhabdoid tumors (ATRTs) are recently defined highly aggressive embryonal central nervous system tumors with a poor prognosis and no definitive guidelines for treatment. We report on the importance of an initial correct diagnosis and disease‐specific therapy on outcome in 22 consecutive patients and propose a new treatment strategy. From 1992 to 2012, nine patients initially diagnosed correctly as ATRT (cohort A, median age 24 months) were treated according to an intensive multimodal regimen (MUV‐ATRT) consisting of three 9‐week courses of a dose‐dense regimen including doxorubicin, cyclophosphamide, vincristine, ifosfamide, cisplatin, etoposide, and methotrexate augmented with intrathecal therapy, followed by high‐dose chemotherapy (HDCT) and completed with local radiotherapy. Thirteen patients were treated differently (cohort B, median age 30 months) most of whom according to protocols in use for their respective diagnoses. As of July 2013, 5‐year overall survival (OS) and event‐free survival (EFS) for all 22 consecutive patients was 56.3 ± 11.3% and 52.9 ± 11.0%, respectively. For MUV‐ATRT regimen‐treated patients (cohort A) 5‐year OS was 100% and EFS was 88.9 ± 10.5%. For patients treated differently (cohort B) 5‐year OS and EFS were 28.8 ± 13.1%. All nine MUV‐ATRT regimen‐treated patients are alive for a median of 76 months (range: 16–197), eight in first complete remission. Our results compare favorably to previously published data. The drug combination and sequence used in the proposed MUV‐ATRT regimen appear to be efficacious in preventing early relapses also in young children with M1–M3 stage disease allowing postponement of radiotherapy until after HDCT.

Ruptured carotid artery aneurysms of the ophthalmic (C6) segment: clinical and angiographic long-term follow-up of a multidisciplinary management strategy

Background: The management of ruptured C6 aneurysms remains controversial. Detailed long-term outcome data are still lacking. Thus the present study provided a detailed long term follow-up for a multidisciplinary approach combining microsurgical clipping, endovascular embolisation and parent artery occlusion with/without bypass protection. Methods: In our single centre analysis of 64 consecutive patients, indications for microsurgery were: superior aneurysm projection, giant/large or wide necked aneurysms and aneurysms at branching sites. Indications for embolisation were: narrow necks, neck calcification, close aneurysm relation to the clinoid process or adhesion to the distal dural ring, and aneurysm location in the concavity of the carotid siphon curve. Results: 23 patients (35.9%) underwent microsurgery, 38 patients (59.4%) embolisation and three patients (4.7%) parent artery occlusion under bypass protection. Retreatment was required in 20.9% (surgery 8.7%, endovascular 31.6%). Procedure related transient complications occurred in 10.9% (surgery 13.0%, endovascular 10.5%). Procedure related permanent morbidities occurred in 6.3% (surgery 8.7%, endovascular 5.3%), including visual deficits in 4.7% (surgery 4.4%, endovascular 5.3%). One endovascular patient died. Angiographic follow-up (29.2 (SD 31.9) months) revealed total aneurysm occlusion in 94.4% of the surgical and 82.9% of the endovascular patients. Clinical follow-up (58.7 (SD 47.6) months) showed 73.4% of the population reaching Glasgow Outcome Scale 4–5, these data being equivalent to the International Subarachnoid Aneurysm Trial (ISAT) outcomes. Conclusions: Based on favourable neuroradiological and ophthalmological outcomes, microsurgery is recommended for superiorly projecting aneurysms, especially aneurysms involving the ophthalmic artery, and for giant/large or wide necked aneurysms. Based on stable aneurysm occlusion and excellent clinical outcomes, embolisation can be recommended for inferiorly/medially projecting small, narrow necked aneurysms.

Decompressive Hemicraniectomy After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND The aim of this study was to document the effects of decompressive hemicraniectomy (DHC) on neurologic outcome in patients treated for aneurysmal subarachnoid hemorrhage (SAH) and developing otherwise uncontrollable intracranial hypertension. METHODS Sixty-six of the 964 patients (6.8%) treated for aneurysmal SAH underwent DHC and were stratified as follows: Group 1, patients undergoing aneurysm clipping and DHC in one surgical sitting (i.e., primary DHC). Group 2, patients receiving aneurysm embolization and thereafter undergoing DHC. Group 3, patients undergoing standard aneurysm surgery and requiring DHC later in the post-SAH period. Group 4, patients with insufficient primary DHC and later requiring surgical enlargement of the craniectomy. RESULTS Outcome was not influenced by the timing of DHC, but depended on the pathology underlying intracranial hypertension (i.e., whether lesions were primary hemorrhagic or secondary ischemic in origin). Patients with large hematomas, undergoing primary, secondary, or repeat DHC (46/66) had significantly better outcomes than the 20 patients treated for edema and delayed ischemic infarctions. There were 16 (34.8%) of the 46 patients in the hematoma group, but only 2 (10.0%) of the 20 patients in the ischemia group had favorable neurologic outcomes, defined as modified Rankin Scale scores 0-3 (P value = 0.038). CONCLUSIONS In the largest series of SAH patients to date who received both microsurgical and endovascular treatment of ruptured aneurysms, and who underwent DHC for otherwise uncontrollable intracranial hypertension. Neurologic outcome was significantly correlated with the pathology underlying intracranial hypertension. DHC beneficially affected neurologic outcomes in patients with space-occupying hematomas, whereas patients suffering delayed ischemic strokes did not benefit to the same extent.

Epilepsy surgery in children and adolescents with malformations of cortical development—-Outcome and impact of the new ILAE classification on focal cortical dysplasia

UNLABELLED To determine long-term efficacy and safety of epilepsy surgery in children and adolescents with malformations of cortical development (MCD) and to identify differences in seizure outcome of the various MCD subgroups. Special focus was set on the newly introduced International League Against Epilepsy (ILAE) classification of focal cortical dysplasia (FCD). STUDY DESIGN This is a single center retrospective cross-sectional analysis of prospectively collected data. INCLUSION CRITERIA age at surgery <18 years, pre-surgical evaluation and epilepsy surgery performed at the Vienna pediatric epilepsy center, histologically proven MCD, complete follow-up data for at least 12 months. Clinical variables evaluated: type and localization of MCD, type of surgery and a variety of clinical characteristics reported to be associated with (un-)favorable outcomes. MCD were classified following the existing classification schemes (Barkovich et al., 2012. Brain. 135, 1348-1369; Palmini et al., 2004. Neurology. 62, S2-S8) and the ILAE classification for FCD recently proposed by Blümcke in 2011. Seizure outcome was classified using the ILAE classification proposed by Wieser in 2001. RESULTS 60 Patients (51.7% male) were included. Follow up was up to 14 (mean 4.4 ± 3.2) years. Mean age at surgery was 8.0 ± 6.0 (median 6.0) years; mean age at epilepsy onset was 2.9 ± 3.2 (median 2.0) years; duration of epilepsy before surgery was 4.8 ± 4.4 (median 3.0) years. 80% of the patients were seizure free at last follow-up. AEDs were successfully withdrawn in 56.7% of all patients. Extended surgery, lesion localization in the temporal lobes and absence of inter-ictal spikes in postsurgical EEG recordings were predictive of favorable seizure outcomes after surgery. However, no association was found between outcome and MCD sub-types. Epilepsy surgery is highly effective in carefully selected drug-resistant children with MCD. Surrogate markers for complete resection of the epileptogenic zone remain the only significant predictors for seizure freedom after surgery.

Vertical perithalamic hemispherotomy: A single‐center experience in 40 pediatric patients with epilepsy

The current concept for hemispherotomy includes various lateral techniques and the vertical perithalamic hemispherotomy introduced by Delalande in 1992. We have chosen the vertical approach because of advantages that possibly influence outcome: the possibility to completely disconnect the hemisphere at the level of the thalamus obviating both the need to resect the insula and the need to open and dissect the subarachnoid space of the Sylvian fissure.

Computerized assessment of angiographic occlusion rate and coil density in embolized human cerebral aneurysms.

BACKGROUND AND PURPOSE: Computerized methods have been introduced for more objective quantification of angiographic occlusion rate and coil density as parameters of successful embolization. This study aimed 1) to evaluate this new computerized method for angiographic occlusion rating and coil density calculations by comparison with corresponding histometric parameters from retrieved human aneurysms, and 2) to compare the new computerized method with the present standard of subjective angiographic occlusion rating. MATERIALS AND METHODS: From 14 postmortem-retrieved human aneurysms, angiographic occlusion rate was determined by contrast medium attenuation-gradient distinction on digital subtraction angiographs after Guglielmi detachable coil (GDC) embolization. Angiographic coil density was calculated, approximating aneurysms as ellipsoid and coils as cylindric volumes. On surface-stained histologic ground sections of the respective aneurysms, the occluded aneurysm area and coil area were measured. Then, we calculated and compared the histometric occlusion rates and coil densities with the corresponding angiographic parameters by using the Wilcoxon paired signed-rank test and the Spearman rank correlation. RESULTS: Computerized angiographic occlusion rates (75%–100%) showed good correlation (r = 0.799; P < .01) with histometric occlusion-rates (61%–100%), resulting in no statistically significant differences (P = .2163). With 5.1% (±3.8), the mean difference between computerized angiographic occlusion rates and histometry was substantially lower compared with 10.7% (±8.7) mean difference between subjective angiographic estimations and histometry. Calculated angiographic coil density (13%–32%) significantly differed from histometric coil density (8%–35%; P < .05). CONCLUSIONS: For recanalized aneurysms, computerized angiographic occlusion rating showed better correspondence with histometry compared with subjective angiographic occlusion rating. Clinical application of this new tool may lead to more objective cutoff values for re-embolization indications. The value of coil density calculations seems limited by the approximation of the aneurysms as ellipsoid volumes.

Embryonal tumor with abundant neuropil and true rosettes (ETANTR) with loss of morphological but retained genetic key features during progression

Embryonal tumor with abundant neuropil and true rosettes (ETANTR) is a recently recognized, rare embryonal CNS tumor, which predominantly occurs in young children and is associated with a highly aggressive disease course [1–3, 5–8, 13, 14, 18, 19, 23]. The histopathological diagnosis of ETANTR is based on the presence of primitive neuroectodermal tumor cells forming distinct multilayered ‘ependymoblastic’ rosettes and characteristic neuropil islands. Recently, genome-wide analyses have revealed a novel amplification at 19q13.42 [16, 19], which is meanwhile considered the genetic hallmark of ETANTR [13, 16]. The characteristic clinical, morphological, and genetic features support the concept of a distinct CNS PNET variant and suggest its introduction to the WHO classification of Tumors of the Central Nervous System [17]. As the amplification at 19q13.42 has also been found in the vast majority of ependymoblastomas analyzed to date [13, 16], the common genetic background suggests the fusion of these two tumor types to a single entity. Herein, we report for the first time the evolution of morphological features and genetic aberrations during the disease course in a patient with ETANTR. A 33-monthold girl presented with a 6-month history of episodic headaches, increased head circumference and mild gait disturbance. Magnetic resonance (MR) imaging showed a 9.6 9 8.6 9 11.7 cm left parieto-occipital, space-occupying, partly cystic lesion displaying T1-weighted hypoto isointense signals (Fig. 1a) with cerebrospinal fluid-intense cysts on FLAIR sequence (Fig. 1b), and marked choline/ creatine increase as a sign of cell proliferation on single voxel spectroscopy (Fig. 1c). Near-total surgical resection was performed. Histopathology revealed a primitive neuroectodermal tumor with highly cellular areas. Furthermore, hypocellular neuropil islands and multilayered rosettes were

Superselective Indocyanine Green Angiography for Selective Revascularization in the Management of Peripheral Cerebral Aneurysms

SUMMARY: This report describes the management of a fusiform peripheral middle cerebral artery aneurysm by endovascular parent artery occlusion under bypass protection. Localization of the recipient cortical artery was accomplished after craniotomy by superselective injection of diluted ICG dye via a microcatheter positioned proximal to the aneurysm. This report demonstrates that superselective ICG angiography can be a beneficial alternative technique to identify the best anastomosis site intraoperatively.