[Interdisciplinary neurovascular networks: state of the art]. / Interdisziplinäre neurovaskuläre Netzwerke: eine Standortbestimmung.

BACKGROUND: In order to treat the complete spectrum of neurovascular diseases at a high level of quality, which goes beyond the purely acute treatment of stroke, the German Stroke Society (DSG) together with the German Societies for Neurosurgery and Neuroradiology developed a certification procedure for neurovascular networks (NVN). Structurally, a NVN consists of a coordinating center with at least three neurovascular network partners with a certified stroke unit. From 2018 to 2020 a total of 15 NVN have so far been audited and certified according to this new standard. OBJECTIVE: How efficient are the NVN? Are high standards maintained? MATERIAL AND METHODS: The reports of the audits were analyzed. The data were taken from the period 2017-2019. RESULTS: The 15 NVN treated a total of 86,510 stroke patients in the years examined and were networked with a total of 107 partner clinics, which were situated an average of 25 km from the coordinating center and transferred a total of 2726 patients. The coordinating centers performed 2463 thrombectomies and treated 2383 patients with nontraumatic intracerebral bleeding. In 712 patients with acute aneurysmatic subarachnoid hemorrhages endovascular treatment was carried out and clipping in 401. The audit was successful in the majority of the NVN. CONCLUSION: The certification process of NVN has been successfully established and the audits proved to be a useful instrument for quality control and improvement. The 15 NVN are highly efficient and treat more than one quarter of stroke patients in German stroke units.

Impact of dexamethasone in patients with aneurysmal subarachnoid haemorrhage.

BACKGROUND AND PURPOSE: The role of corticosteroids in the treatment of patients with aneurysmal subarachnoid haemorrhage (SAH) has remained controversial for decades. Recent studies have suggested that the administration of corticosteroids in SAH patients is associated with favourable outcomes. Given their significant adverse effects, it is essential to identify those patients who will benefit from treatment with corticosteroids. METHODS: A retrospective analysis of a prospectively collected cohort (n = 306) with SAH who were treated by microsurgical clipping or endovascular intervention was performed. The role of dexamethasone administration was analysed with regard to clinical conditions and SAH-related complications. Outcome was assessed at discharge and during follow-up using the Glasgow Outcome Scale (GOS). RESULTS: Patients treated with dexamethasone presented with more episodes of hyperglycaemia (P < 0.001), more overall infections (P < 0.001) and more ventriculostomy-related infections (P = 0.004). Multivariate analysis demonstrated that treatment with dexamethasone was associated with an unfavourable outcome at discharge (GOS 1-3) [odds ratio (OR) 2.814, 95% confidence interval (CI) 1.440-5.497, P = 0.002]. In the subgroup of microsurgically treated patients, dexamethasone administration was associated with a favourable outcome at follow-up (OR 0.193, 95% CI 0.06-0.621, P = 0.006). A higher risk for unfavourable outcome (OR 3.382, 95% CI 1.67-6.849, P = 0.001) at discharge was observed in endovascularly treated patients who received dexamethasone but this had no impact on the outcome at follow-up. CONCLUSIONS: Treatment with dexamethasone seems to be associated with a risk reduction for an unfavourable outcome in those patients who underwent microsurgical clipping. Despite an increased frequency of adverse effects, glucocorticoids may have a potential benefit in this specific surgical subgroup compared to endovascularly treated SAH patients.

Changes to the cell, tissue and architecture levels in cranial suture synostosis reveal a problem of timing in bone development.

Premature fusion of cranial sutures is a common problem with an incidence of 3-5 per 10,000 live births. Despite progress in understanding molecular/genetic factors affecting suture function, the complex process of premature fusion is still poorly understood. In the present study, corresponding excised segments of nine patent and nine prematurely fused sagittal sutures from infants (age range 3-7 months) with a special emphasis on their hierarchical structural configuration were compared. Cell, tissue and architecture characteristics were analysed by transmitted and polarised light microscopy, 2D-histomorphometry, backscattered electron microscopy and energy-dispersive-x-ray analyses. Apart from wider sutural gaps, patent sutures showed histologically increased new bone formation compared to reduced new bone formation and osseous edges with a more mature structure in the fused portions of the sutures. This pattern was accompanied by a lower osteocyte lacunar density and a higher number of evenly mineralised osteons, reflecting pronounced lamellar bone characteristics along the prematurely fused sutures. In contrast, increases in osteocyte lacunar number and size accompanied by mineralisation heterogeneity and randomly oriented collagen fibres predominantly signified woven bone characteristics in patent, still growing suture segments. The already established woven-to-lamellar bone transition provides evidence of advanced bone development in synostotic sutures. Since structural and compositional features of prematurely fused sutures did not show signs of pathological/defective ossification processes, this supports the theory of a normal ossification process in suture synostosis - just locally commencing too early. These histomorphological findings may provide the basis for a better understanding of the pathomechanism of craniosynostosis, and for future strategies to predict suture fusion and to determine surgical intervention.

[Intraoperative electrophysiological monitoring with evoked potentials]. / Intraoperatives elektrophysiologisches Monitoring mit evozierten Potenzialen.

During the last 30 years intraoperative electrophysiological monitoring (IOEM) has gained increasing importance in monitoring the function of neuronal structures and the intraoperative detection of impending new neurological deficits. The use of IOEM could reduce the incidence of postoperative neurological deficits after various surgical procedures. Motor evoked potentials (MEP) seem to be superior to other methods for many indications regarding monitoring of the central nervous system. During the application of IOEM general anesthesia should be provided by total intravenous anesthesia with propofol with an emphasis on a continuous high opioid dosage. When intraoperative MEP or electromyography guidance is planned, muscle relaxation must be either completely omitted or maintained in a titrated dose range in a steady state. The IOEM can be performed by surgeons, neurologists and neurophysiologists or increasingly more by anesthesiologists. However, to guarantee a safe application and interpretation, sufficient knowledge of the effects of the surgical procedure and pharmacological and physiological influences on the neurophysiological findings are indispensable.

Occipital nerve block is effective in craniofacial neuralgias but not in idiopathic persistent facial pain.

Occipital nerve block (ONB) has been used in several primary headache syndromes with good results. Information on its effects in facial pain is sparse. In this chart review, the efficacy of ONB using lidocaine and dexamethasone was evaluated in 20 patients with craniofacial pain syndromes comprising 8 patients with trigeminal neuralgia, 6 with trigeminal neuropathic pain, 5 with persistent idiopathic facial pain and 1 with occipital neuralgia. Response was defined as an at least 50% reduction of original pain. Mean response rate was 55% with greatest efficacy in trigeminal (75%) and occipital neuralgia (100%) and less efficacy in trigeminal neuropathic pain (50%) and persistent idiopathic facial pain (20%). The effects lasted for an average of 27 days with sustained benefits for 69, 77 and 107 days in three patients. Side effects were reported in 50%, albeit transient and mild in nature. ONBs are effective in trigeminal pain involving the second and third branch and seem to be most effective in craniofacial neuralgias. They should be considered in facial pain before more invasive approaches, such as thermocoagulation or vascular decompression, are performed, given that side effects are mild and the procedure is minimally invasive.

Experiences with a 3D4K Digital Exoscope System (ORBEYE) in a Wide Range of Neurosurgical Procedures.

BACKGROUND: Exoscopic 3D4K video systems (EX) have recently been introduced as an alternative to conventional operating microscopes (OM). However, experience in handling and setup remains scarce. This study evaluated the practicability of exoscopic surgery in a wide range of procedures. MATERIAL AND METHODS: All EX operations performed between August 2018 and May 2020 were evaluated and compared with procedures using OM. A standardized questionnaire was used to evaluate surgeons' comfort, image quality (including fluorescence modes), and handling. RESULTS: In all, 513 EX operations were performed during the investigated period. EX was generally rated as a valuable surgical tool. In particular, the digital 5-aminolevulinic acid (5-ALA) fluorescence and the comfort level of posture during surgery were stated to be superior to OM (100 and 83%, respectively). CONCLUSION: EX has been used for a significant number of neurosurgical procedures. While presuming that the technical methodology as such will not influence outcome of glioma surgery, proof of equipoise between different techniques expands the spectrum of surgical environments giving neurosurgeons a choice to work according to their preferred ergonomics.

How to deal with incompletely treated AVMs: experience of 67 cases and review of the literature.

INTRODUCTION: Despite the availability of multimodal treatment options, some arteriovenous malformations remain difficult to treat, either for intrinsic reasons at initial presentation or for reasons evolving during the course of treatment. Frequently, such cases can be easily resolved with further therapy, but some become a continuously growing treatment dilemma while exhausting dwindling therapeutic options. PATIENTS AND METHODS: A retrospective analysis was performed to identify patients with cerebral AVM who were treated unsuccessfully. Treatment was termed "not successful" if (1) postoperative angiography showed a residual AVM or missing flow reduction after palliative embolization, (2) therapy was associated with a substantial deterioration of existing neurological deficits or death, or (3) rebleeding from residual AVM occurred after therapy. Special interest was focused on the angiographic appearance of residual AVMs, their characteristic features, and their follow-up regarding second and third therapies. RESULTS: According to these criteria we identified 46 internal patients from our own series of 474 patients and 21 external patients who were referred from other institutions or sought a second opinion after incomplete treatment elsewhere. Out of those 67 cases, 50 patients (74.6%) were diagnosed with a residual AVM. Eleven patients (16.4%) experienced a deterioration of their clinical condition under therapy. Six patients did not show a flow reduction after palliative embolization. Twenty-five of the 67 patients were readmitted because of an ICH, either originating from an AVM residual or under palliative embolization. Thus, an increased risk of re-hemorrhage was found for palliative embolization (n = 16) in partially treated lesions (n = 10) and in patients with AVM grade IV and V located in eloquent regions (n = 22). In dealing with residual AVMs, microsurgical resection alone or in combination was found to be the most efficient therapeutic option, being successful in 58.9% of cases. CONCLUSION: An estimated 10% of AVM treatments may fail because of inadequate selection of either patients or management. Besides, for thorough decision-making, angiographic follow-up in all AVM patients is mandatory to allow an early identification of patients with an incompletely treated AVM requiring a second attempt. Major attention should be focused especially on high-risk subgroups with complex AVMs, partially treated AVMs, or those treated by only a palliative regimen.

[Prognosis after surgical treatment of spinal metastases due to lung cancer]. / Prognose nach operativem Wirbelsäuleneingriff bei Bronchialkarzinommetastasen.

BACKGROUND: Patients with spine metastases due to lung cancer suffer from a reduced lifespan. For a more precise prognosis, it is important to define parameters which influence the individual survival time. This study reviewed the mean survival time of patients who had undergone surgery because of spine metastases due to lung cancer. It should be evaluated whether the postsurgical survival time is dependent on the length of time between diagnosis and surgery and from the histological type of the tumor. MATERIAL AND METHODS: Between January 1999 and December 2003, 68 patients had undergone spine surgery because of spine metastases due to lung cancer at the department of traumatology of the St. Georg General Hospital in Hamburg, Germany. Retrospective data were collected from the hospital documentary system regarding the period between diagnosis of lung cancer and date of surgical treatment, and regarding the histological type of the tumor. The postsurgical survival times were evaluated using data from the Hamburger Cancer Index and from general practitioners. These times were analysed afterward according to the defined parameters. RESULTS: The average age was 62.6 years, and 24 female and 44 male patients were included. It was possible to evaluate the survival time of 65 patients. The average survival time of those with preoperative unknown primary manifestation (20 patients) was 88 days, in the group of patients with lung cancer histories of less than 12 months (35 patients) 141 days, and with patients with lung cancer histories of lung cancer longer than 12 months (13 patients) it was 171 days. The mean survival times after surgical treatment were 122 days for patients suffering from non-small-cell lung cancer (45 patients), 128 days for those with small-cell lung cancer (20 patients), and 247 days for patients with other histological types (three patients). DISCUSSION: The prognosis of patients after spine surgery for lung cancer metastases is poor. The indication for surgical treatment of spinal metastases due to lung cancer should be critically discussed. Especially patients with unknown primary manifestation might benefit from a conservative approach. With respect to the patients' reduced lifespan, they, their relatives, and the nursing staff should be carefully informed.

[Surgical complications after metastatic infiltration of the spine]. / Komplikationen bei operativer Dekompression an der tumorinfiltrierten Wirbelsäule.

INTRODUCTION: This study evaluated the intra- and post-surgical complications on tumor affected spines. Complications were analyzed according to selected patient groups so that risk factors could be determined. MATERIAL AND METHODS: Between January 1999 and December 2004, 401 patients underwent surgery because of spinal metastases in the Department of Traumatology, General Hospital St. Georg in Hamburg. Data were obtained from the hospital's documentary system. The results of this study were compared to other published studies. RESULTS: The average age of patients was 63 years (24-88) and there were 172 (42.9%) females and 229 (57.1%) males. A total of 118 (29.4%) patients suffered from 235 complications and 22 (5.5%) died. DISCUSSION: Patient's age >70 years, patients with a preoperative neurological deficit, and patients with heavily bleeding metastases are at high risk for complications. The dorsoventral/dorsolateral approach had the highest complication rate.

Hollow mandrin facilitates external ventricular drainage placement.

BACKGROUND: Placement of ventricular catheters is a routine procedure in neurosurgery. Ventricle puncture is done using a flexible ventricular catheter stabilised by a solid steel mandrin in order to improve stability during brain penetration. A correct catheter placement is confirmed after removing the solid steel mandrin by observation of cerebrospinal fluid (CSF) flow out of the flexible catheter. Incorrect placement makes further punctures necessary. The newly developed device allows CSF flow observation during the puncture procedure and in addition precise intracranial pressure (ICP) measurement. METHOD: The developed mandrin is hollow with a blunt tip. On one side 4-5 small holes with a diameter of 0.8 mm are drilled corresponding exactly with the holes in the ventricular catheter, allowing CSF to pass into the hollow mandrin as soon as the ventricle is reached. By connecting a small translucent tube at the distal portion of the hollow mandrin ICP can be measured without loss of CSF. The system has been used in 15 patients with subarachnoid haemorrhage (SAH) or intraventricular haemeorrhage (IVH) and subsequent hydrocephalus. FINDINGS: The new system improved the external ventricular drainage implantation procedure. In all 15 patients catheter placement was correct. ICP measurement was easy to perform immediately at ventricle puncture. In 4 patients at puncture no spontaneous CSF flow was observed, therefore by connecting a syringe and gentle aspiration of CSF correct placement was confirmed in this unexpected low pressure hydrocephalus. Otherwise by using the conventional technique further punctures would have been necessary. CONCLUSIONS: Advantages of the new technique are less puncture procedures with a lower risk of damage to neural structures and reduced risk of intracranial haemorrhages. Implantation of the ventricular catheter to far into the brain can be monitored and this complication can be overcome. Using the connected pressure monitoring tube an exact measurement of the opening intracranial pressure can be obtained performed without losing CSF.

Classification of cerebral arteriovenous malformations and intranidal flow patterns by color-encoded 4D-hybrid-MRA.

BACKGROUND AND PURPOSE: 4D MRA has been evolving as a noninvasive supplement for DSA. The purpose of this study was to evaluate the feasibility of a newly developed blood flow visualization technique for the classification of cerebral AVMs. We hypothesized that 4D-hMRA allows detection of different flow patterns within the nidus as well as differentiation of feeders and draining veins and has very good agreement with DSA regarding the Spetzler-Martin grade. MATERIALS AND METHODS: Thirty-one consecutive patients with AVMs were evaluated by using 4D-hMRA and DSA by 2 blinded raters. Rating criteria included Spetzler-Martin score and other morphologic variables together with a new scale for 3 intranidal flow patterns (homogeneous = 1, unidirectional = 2, heterogeneous = 3). RESULTS: The Spetzler-Martin grades were rated different from DSA in 5 cases by rater 1 and in 3 cases by rater 2 with an excellent interrater reliability of κ = 0.96 (4/31, 1 by size and 3 by drainage). Each reader missed 5 feeders on 4D-hMRA. Draining veins were distinguished in the temporal course in 7 on DSA but in 8 and 12 on 4D-hybrid-MRA (raters 1 and 2 respectively), with κ = 0.79. A type 1 intranidal flow pattern was recognizable in 9 (30%) patients; type 2, in 19 (60%); and type 3, in 3 (10%). CONCLUSIONS: 4D-hMRA allows reliable Spetzler-Martin grading and detection of brain arteriovenous malformation feeding arteries and draining veins, with the drawback that for small vessels DSA is still needed. Draining veins might even be detected with higher sensitivity than on DSA. Discrimination of different intranidal flow patterns is possible, but their relevance for hemorrhage risk assessment and therapy planning requires further study.

Intranidal signal distribution in post-contrast time-of-flight MRA is associated with rupture risk factors in arteriovenous malformations.

PURPOSE: To evaluate if arteriovenous malformations (AVMs) that are associated with a high rupture risk (HRR) are represented by different intranidal Time-of-Flight (TOF) magnetic resonance angiography intensity distributions compared to those with presumably low rupture risk (LRR). METHODS: Fifty post-contrast TOF datasets of patients with an AVM were analyzed in this study. The patients were classified to the HRR group in case of a deep location, presence of exclusive deep venous drainage, previous hemorrhagic event or a combination thereof. For each TOF dataset, the AVM nidus was semi-automatically delineated and used for histogram extraction. Each histogram was analyzed by calculating the skewness, kurtosis, mean and median intensity and full-width-half-maximum. Statistical analysis was performed using parameter-wise two-sided t-tests of the parameters between the two groups. RESULTS: Based on morphological analysis, 21 patients were classified to the HRR and 29 patients to the LRR group. Statistical analysis revealed that TOF intensity distributions of HRR AVMs exhibit a significant higher skewness (p=0.0005) parameter compared to LRR AVMs. Contrary to these findings, no significant differences were found for the other parameters evaluated. CONCLUSION: Intranidal flow heterogeneity, for example, caused by turbulent flow conditions, may play an important role for risk of a hemorrhage. An analysis of post-contrast TOF intensities within the nidus of an AVM may offer simple and valuable information for clinical risk estimation of AVMs and needs to be tested prospectively.

[Functional and radiological outcome after ACDF in 67 cases]. / Funktionelles und radiologisches Outcome nach ACDF bei 67 Patienten.

INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) is an accepted technique for the treatment of symptomatic disc disease at the cervical spine. In this study the clinical outcome of 67 patients who underwent ACDF due to cervical disc herniation are presented. Based on the results of this study and those of other working groups the pros and cons of ACDF were analysed and discussed. METHODS: 67 patients with cervical disc herniation underwent ACDF of a single level. Clinical and/or radiological examination was performed immediately preoperatively, one day after surgery and 7 months postoperatively to assess the course of the examined parameters. RESULTS: The mean age of the patients was 53 years (range: 19-81). Seven months after surgery we observed pain reduction in 91% of the cases, range of motion in the neck improvement in 79%, motor function improvement in 78% and a function improvement in sensitivity in 78% of the cases. Analysis of the CT scans 7 months after surgery showed a fusion rate of 85% on the cervical spine segment that was treated. DISCUSSION: The results of this study demonstrate that ACDF is an effective surgical treatment for patients suffering from disc degeneration at the cervical spine. Over 80% of the patients showed an improved neurological status and had less pain than prior to surgery. It is a safe surgical technique with a low rate of complications and a high rate of bony consolidation on the treated level.

Non-conventional treatments sought by patients after surgery for intramedullary spinal cord tumors.

OBJECTIVE: Despite modern microsurgical techniques and interdisciplinary treatment options, intramedullary spinal cord tumors often lead to profound neurological deficits. Some patients may search for non-scientific or unconventional therapeutic options to treat the symptoms induced by the tumor itself or arising from treatment. The extent of non-scientific therapy use, the rationale behind it, and costs of these forms of therapy are unknown. METHODS: A questionnaire consisting of 20 questions was sent to 60 patients of a single neurosurgical center who had undergone surgery for an intramedullary spinal cord tumor. A retrospective study was carried out based on this data. Histological findings ranged from ependymoma (52.9%), hemangioblastoma (17.6%), cavernoma (14.7%), astrocytoma (8.8%), oligodendroglioma (2.9%) to ganglioglioma (2.9%). Non-scientific therapy was defined as a method not used in routine clinical practice for the treatment of symptoms induced by intramedullary spinal cord tumors. RESULTS: A total of 38 questionnaires was returned. About 55.3% of the patients claimed to use non-scientific therapies. No significant difference between histological types and the percentage of alternative therapy use was detected. There was a gender difference. One third (non user group) to one fourth (user group) did not feel adequately informed about their disease. The monthly costs for non-scientific therapies ranged from 50 to 500 Euros. The main motive for the use of non-scientific therapies was the wish to try everything possible. CONCLUSION: In the daily clinical routine, patients' use of non-scientific therapies may be largely overlooked and underestimated. Neurooncologists should be aware of this phenomenon and encourage an open but critical dialogue with their patients.

Training microneurosurgery - four years experiences with an in vivo model.

OBJECTIVE: Enquiries among surgical trainees revealed an increasing discontent regarding their quality of training. 40 % of young surgical trainees judge their training as inadequate and 70% are offered no structured training programme. Working time restrictions and economic pressure may be strong factors hindering residents from becoming skillful surgeons. Therefore, additional forms of training seem to be needed. METHOD: An in vivo swine model was evaluated for its practical use in training neurosurgical residents. Surgical procedures included craniotomy, dural opening, brain surgery and excision of an artificial tumour created by injection of coloured fibrin glue. Microscopy and bleeding management with bipolar cautery and haemostyptics were an integrated part of training. Supervision by experienced neurosurgeons with up to 3 trainees in a 2-day course was warranted. Standardised questionnairies before and after training were used to assess the quality and utility of the programme. RESULTS: 24 residents have participated in the course (1 (st)-5 (th) year of training). Minor experience with less than 100 conducting surgeries was seen in 59% of trainees. 14 residents had participated in more than 100 surgeries as first assistant. Spinal surgery was the predominant common experience. All participants judged their surgical training as insufficient. 77% had no microsurgical lab at their clinics. Expectations for the course were met for all trainees and the tutorials judged as excellent (65%) or good (35%). Positive evaluations of the in vivo model (97%), a realistic laboratory setup (94%), the working environment (94%) and close supervision (94%) showed that these were the most favourable aspects of the course. CONCLUSION: Educational training in surgical specialities is becoming a major problem in our daily practice and requires additional training facilities. In this context, in vivo models are an ideal opportunity for young neurosurgeons to train bleeding management and surgical complications in particular. This educational form is thought to be a unique training model which is now added by spinal and neurovascular courses.

Diagnostic and therapeutic considerations for "mycotic" cerebral aneurysms: 2 case reports and review of the literature.

OBJECTIVE: Cerebral aneurysms of an infectious etiology, so-called "mycotic" aneurysms, are rare neurovascular pathologies. Primary treatment may be targeted on the aneurysm, but care has to be driven by the underlying pathology to prevent an often fatal clinical course with a mortality rate reaching 90%. 2 case reports are presented, and the diagnostic and therapeutic issues outlined by reviewing the literature. CASE REPORT: A 33-year-old female was admitted to our hospital with a sudden left-sided hemiparesis following a 3-week history of fever. An atypical intracerebral hemorrhage of the right parietal lobe due to a ruptured aneurysm of the distal middle cerebral artery (MCA) was diagnosed. Blood cultures containing Streptococcus sanguinus were the only finding for an infectious origin. Antibiotic therapy was started, followed by neurosurgical evacuation of the hematoma and clipping of the aneurysm. In a second case, endovascular coiling was the choice of treatment in a 38-year-old male presenting with a distal bifurcation aneurysm of the frontal MCA insular branch. An aortic valve replacement had been previously performed due to a congenital heart condition. The primary site of infection remained unclear and a 4-week course of broad-spectrum antibiotics was given intravenously. DISCUSSION: Cerebral aneurysms far distal to the usual sites of congenital aneurysms, organisms in blood chemistry, endocarditis, symptoms of infection, atypically located intracerebral hemorrhages, and young patients with immunodeficiency are strong factors for an infectious aneurysm. Cerebral angiography is mandatory to exclude aneurysms at other sites and early targeted antimicrobial treatment is crucial in these cases. Elimination of the aneurysm itself should be evaluated carefully because treating these aneurysms remains challenging compared to the ordinary group of cerebral aneurysms. Reconstructive procedures without sacrificing the parent artery often fail due to the fusiform and fragile aneurysm wall. CONCLUSION: Cerebral aneurysms of an infectious origin often have a disastrous clinical course in which morbidity and mortality can be reduced by early diagnosis, appropriate antimicrobial therapy, and aneurysm elimination by an experienced team. Apart from the initial treatment, major attention should be focused on a thorough follow-up to confirm complete cure of the primary site of infection.

Therapeutic clues in spinal dural arteriovenous fistulas - a 30 year experience of 156 cases.

BACKGROUND: Spinal dural arteriovenous fistulae (SDAVF) are rare but remain the most common type of spinal vascular malformations. Treatment options for SDAVF include endovascular embolization, microsurgical dissection or a combination of both. But the optimal treatment paradigm has yet to be defined and may well be an individualized interdisciplinary combinatorial approach. MATERIAL AND METHODS: From 1980 to 2008, 156 patients with the diagnosis of SDAVF were treated by neuroradiological and neurosurgical means. Based on the procedure-related complications we retrospectively analyzed our data to elucidate the reasons for endovascular failure and the evolution of the surgical technique. RESULTS: 156 patients were included in this study. There were 31 (19.9%) female and 125 (80.1%) male patients. Average age at the time of diagnosis was 60.8 years. 102 out of 156 (65.4%) underwent endovascular obliteration, 54 (34.6%) patients were treated primarily by surgery. 134 (85.9%) underwent follow-up examination. A total of 29 (18.6%) out of 156 patients could not be treated successfully by endovascular (9.4%) or surgical (4.1%) means. CONCLUSION: Microsurgery can be recommended as the first choice treatment when the fistula's point is unmistakably identified intradurally. Endovascular obliteration may be justifiable in cases with an easy access to a monoradicular feeding artery during diagnostic angiography. Surgery is a definitive treatment with stable long-term results in which procedure-related morbidity is low. During evolution of the combined approach, endovascular coil placement for correct localization of the fistula and the use of intraoperative micro-Doppler was found to be very helpful in increasing the safety of the surgical procedure and minimizing surgical exposure.

Intracranial aneurysms in childhood: report of 8 cases and review of the literature.

OBJECTIVE: Subarachnoid haemorrhage (SAH) due to ruptured cerebral aneurysms is a rare diagnosis in childhood and is believed to differ from that in adults with regard to sex, aneurysm size and location, clinical appearance as well as outcome, suggesting that aneurysms in childhood are a distinct entity. PATIENTS AND METHODS: Seven children and young adults with a mean age of 13.6 years suffered from aneurysmal subarachnoid haemorrhage. On admission two patients were Hunt & Hess (HH) grade I, four were grade III and one was grade V. In addition, there was one 14-year-old boy who presented with seizures and was found to have a non-ruptured aneurysm of the basilar tip. Overall, there were two female and six male patients. Anterior circulation aneurysms were diagnosed in five patients whereas three patients suffered from posterior circulation aneurysm. Five large (10-25 mm) aneurysms and three smaller than 10 mm were found. Surgical clipping of the aneurysms was performed in all patients. RESULTS: Six patients showed no significant disability or no symptoms at all when evaluated with the modified Rankin Scale (mRS 0 or 1). One patient suffered from persisting nerve palsies (mRS 2) and one 6-year-old boy, admitted with HH grade V, died due to the initial poor clinical condition followed by severe brain oedema and secondary complications. CONCLUSIONS: Reviewing the literature, a male predominance, low rate of SAH, high percentage of complex aneurysms and of aneurysms located in the posterior circulation are characteristic features of aneurysms in childhood. Once a cerebral aneurysm is diagnosed in the younger age group, definite therapy should be performed soon as the outcome is expected to be more favourable than in adulthood.

Territorial and microvascular perfusion impairment in brain arteriovenous malformations.

BACKGROUND AND PURPOSE: Both the existence and clinical relevance of a steal phenomenon in brain arteriovenous malformations (AVMs) remains a matter of debate. This study aimed to assess perfusion in the brain adjacent to brain AVMs and to relate these to macrovascular blood flow in a single measurement. MATERIALS AND METHODS: Twenty consecutive patients with AVMs with a median age of 37 years were evaluated by 3T MR imaging by using 3D time-resolved MR angiography to determine blood flow and perfusion patterns. Cerebral perfusion was estimated by using an arterial spin-labeling technique in vascular territories around the nidus and in symmetric regions of interest in the ipsilateral and contralateral hemispheres. Mapping of concentric shells around the nidus was used to define the immediate and adjacent brain and relative perfusion reductions >20% of baseline, termed perinidal dip (PND). RESULTS: A significant reduction in perfusion ratios between ipsilateral and contralateral hemispheres remote to the AVMs was demonstrated in the middle and posterior cerebral artery territories. PND was detected in 5 patients, and 17 patients overall showed reduced perfusion in the perinidal region on visual inspection. There was a negative correlation of the hemispheric territorial perfusion with the affected/nonaffected inflow time ratio (R = -0.402, P = .015). CONCLUSIONS: The perfusion impairment in vascular territories adjacent to brain AVMs that we identified as PND may reflect the existence of 2 levels of perfusion impairment: a territorial and a microvascular perfusion disturbance. Although the hemispheric asymmetry in territorial perfusion seems the result of arterioarterial redistribution, the PND was inhomogeneously distributed within a single vascular territory and thus might result from low perfusion pressure in small arteries and arterioles.