Javier Fandino

Dynamic neutralization of the lumbar spine after microsurgical decompression in acquired lumbar spinal stenosis and segmental instability.

Study Design. Prospective clinical study. Objective. To report the outcome, radiologic findings, and complications in patients undergoing microsurgical radicular decompression and implantation of Dynesys (Zimmer Spine, Münsingen, Switzerland). Summary of Background Data. The currently available peer-reviewed English-language medical literature addressing the use of the dynamic stabilization systems is limited. Indications, clinical results, and implant failure of Dynesys after microsurgical decompression are still controversial. Methods and Results. This study included a total of 37 consecutive patients (mean age 58 years) presenting with acquired lumbar stenosis, signs of segmental instability, and degenerative disc disease underwent lumbar microsurgical decompression and implantation of Dynesys in 1 (n = 11), 2 (n = 17), 3 (n = 9), and 4 segments (n = 1). One patient was lost to follow-up. Lumbar and radicular pain was present in 33 patients (92%). Clinical evaluation included visual analogue scale (leg and back), distribution and severity of pain (%), Prolo Functional and Economic Status, Stauffer Coventry Scale, patients self evaluation, and radiologic assessment preoperative and postoperative at 3 and 12 months. Leg and back pain (visual analogue scale) improved at 12 months from 8.4 ± 2.1 to 3.1 ± 1.4 and from 6.7 ± 2.8 to 4 ± 2.8, respectively. Overall pain severity improved due to reduction of radicular pain from 59.2% to 27.3% after microsurgical decompression. Meanwhile, lumbar pain deteriorated from 40.8% to 47.8%. Twenty-seven percent (patients self-evaluation) and 29.7% (Stauffer Coventry Scale) of the patients described a fair or poor outcome. Moreover, 51% and 54% of the patients had a Prolo Economic Status and Prolo Functional of 4 or 5, respectively. Complications included 4 broken and 2 misplaced screws from a total of 224 screws implanted, 2 loosen systems, and 1 cerebrospinal fistula. At 1-year, a total of 7 patients (19%) required surgical revision. Conclusion. The reported biomechanical principles of Dynesys do not reflect advantages in outcome compared with none or others stabilization systems after microsurgical radicular decompression reported in the literature.

Decompressive craniectomy in severe cerebral venous and dural sinus thrombosis

OBJECTIVE To evaluate the outcome of patients with most severe cerebral venous and dural sinus thrombosis (CVT) after decompressive craniectomy. Indications and techniques for decompressive craniectomy and intensive care regimen are discussed. METHODS Between 2000 and 2004 15 patients with CVT and intracerebral hemorrhage were treated at the Department of Neurosurgery, University Hospital Zurich. Among them, four patients with the most severe illness course were treated with decompressive craniectomy. Indications for decompressive craniectomy were deterioration of level of consciousness with CT signs of space occupying brain edema, venous infarction and congestional bleeding with mass effect, midline shift and obliteration of the basal cisterns. RESULTS Among 15 patients with CVT and intraparenchymatous hemorrhage four patients were treated with decompressive craniectomy. Glasgow Coma Scale (GCS) immediately before the operation was in mean 10.2 (range 6 to 13). No patient showed signs of unilateral or bilateral third nerve palsy before surgery. No surgical complications were observed. All four patients who underwent decompressive craniectomy recovered with favourable functional outcome (Glasgow Outcome Scale; GOS 4 and 5). Anticoagulation therapy with heparin was reconvened 12 hours postoperatively with half dosage and 12 hours later with full dosage. No enlargement of existing intraparenchymatous hematoma or other intracranial bleeding complications occurred. CONCLUSIONS Favorable functional outcome in selected patients with most severe courses of CVT can be achieved after decompressive craniectomy. Postoperative anticoagulation therapy with full dose heparin 24 hours after craniotomy seems to be safe. Precise indications and techniques for combined surgical decompression and thrombectomy deserve to be evaluated in future studies.

First noninvasive thermal ablation of a brain tumor with MR-guided focusedultrasound

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) allows for precisethermal ablation of target tissues. While this emerging modality is increasinglyused for the treatment of various types of extracranial soft tissue tumors, ithas only recently been acknowledged as a modality for noninvasive neurosurgery.MRgFUS has been particularly successful for functional neurosurgery, whereas itsclinical application for tumor neurosurgery has been delayed for varioustechnical and procedural reasons. Here, we report the case of a 63-year-oldpatient presenting with a centrally located recurrent glioblastoma who wasincluded in our ongoing clinical phase I study aimed at evaluating thefeasibility and safety of transcranial MRgFUS for brain tumor ablation. Applying25 high-power sonications under MR imaging guidance, partial tumor ablationcould be achieved without provoking neurological deficits or other adverseeffects in the patient. This proves, for the first time, the feasibility ofusing transcranial MR-guided focused ultrasound to safely ablate substantialvolumes of brain tumor tissue.

Number of burr holes as independent predictor of postoperative recurrence in chronic subdural haematoma.

Chronic subdural haematoma (cSDH) is one of the most frequent neurosurgical entities. Current treatment options include burr hole craniostomy, twist drill craniostomy or craniotomy. While burr hole craniostomy is the most often used technique, there are no studies analysing the use of one vs. two burr holes in respect to recurrence rates and complications. This retrospective study included 76 (age: 60 ± 12 years) patients presenting with cSDH admitted in our institution from January 2004 to December 2005. A total of 21 (27%) patients underwent bilateral craniostomy. The patients were assessed using the Markwalder Scale (2 ± 0.71), Glasgow Coma Scale (14 ± 1) and measuring the haematoma thickness (1.8 ± 0.7 cm). The decision to perform one or two burr hole was made according to the personal preference of the treating neurosurgeon. All patients underwent irrigation and placement of closed-system drainage. Out of the 97 haematoma, 63 (65%) haematomas were treated with two burr holes, whereas 34 (35%) were treated with one burr hole. Patients with one burr hole had a statistically significant (p < 0.05) higher recurrence rate (29 vs. 5%), longer average hospitalization length (11 vs. 9 days) and higher wound infection rate (9% vs. 0%). A multivariate regression analysis identified the number of holes as single predictor for postoperative recurrence rate (r2 = 0.12; p < 0.001). In this study, the treatment of cSDH with one burr hole only is associated with a significantly higher postoperative recurrence rate, longer hospitalization length and higher wound infection rate.

Standard intracranial in vivo animal models of delayed cerebral vasospasm

Object. Animal models provide a basis for clarifying the complex pathogenesis of delayed cerebral vasospasm (DCVS) and for screening of potential therapeutic approaches. Arbitrary use of experimental parameters in current models can lead to results of uncertain relevance. The aim of this work was to identify and analyze the most consistent and feasible models and their parameters for each animal. Methods. An online search of the MEDLINE PubMed and EMBASE medical databases (1969 to week 21 of 2007) was performed using the key words “canine”, “mice”, “rabbit”, “pig”, “rat”, “cat”, and “primate” in combination with “subarachnoid hemorrhage”, “model”, and “vasospasm”. Cross references of each model were checked. Analysis of identified publications was considered in accordance with predetermined eligibility criteria. Results. 1254 abstracts were reviewed and 516 studies were included in the analysis. Then, 66 models in 7 animals were identified. Most often used blood amounts (ml) lead to degree (% vessel narrowing) and peak onset (day) of DCVS within animal models as follows: mice endovascular puncture (various, day 3, 20–62%); rat single injection (0.3 ml, day 2, 19–29%); rat double injection (2x0.3 ml, day 7, 28–47%); rabbit single injection (3 ml, day 3, 19–55%); rabbit double injection (not established, day 5, not established); dog double injection (2x4–5 ml, day 7, 45–66%); primate clot placement (5 ml, day 7, 32–52%). Conclusions. Among the great number of experimental SAH methods and associated parameters only a fistful reliable and consistent models can be identified and recommended. Implementation of more standardized experimental techniques could increase the relevance of future experimental studies.

Use of Fluorescence to Guide Resection or Biopsy of Primary Brain Tumors and Brain Metastases

OBJECT The accurate discrimination between tumor and normal tissue is crucial for determining how much to resect and therefore for the clinical outcome of patients with brain tumors. In recent years, guidance with 5-aminolevulinic acid (5-ALA)-induced intraoperative fluorescence has proven to be a useful surgical adjunct for gross-total resection of high-grade gliomas. The clinical utility of 5-ALA in resection of brain tumors other than glioblastomas has not yet been established. The authors assessed the frequency of positive 5-ALA fluorescence in a cohort of patients with primary brain tumors and metastases. METHODS The authors conducted a single-center retrospective analysis of 531 patients with intracranial tumors treated by 5-ALA-guided resection or biopsy. They analyzed patient characteristics, preoperative and postoperative liver function test results, intraoperative tumor fluorescence, and histological data. They also screened discharge summaries for clinical adverse effects resulting from the administration of 5-ALA. Intraoperative qualitative 5-ALA fluorescence (none, mild, moderate, and strong) was documented by the surgeon and dichotomized into negative and positive fluorescence. RESULTS A total of 458 cases qualified for final analysis. The highest percentage of 5-ALA-positive fluorescence in open resection was found in glioblastomas (96%, n = 99/103). Among other tumors, 5-ALA-positive fluorescence was detected in 88% (n = 21/32) of anaplastic gliomas (WHO Grade III), 40% (n = 8/19) of low-grade gliomas (WHO Grade II), no (n = 0/3) WHO Grade I gliomas, and 77% (n = 85/110) of meningiomas. Among metastases, the highest percentage of 5-ALA-positive fluorescence was detected in adenocarcinomas (48%, n = 13/27). Low rates or absence of positive fluorescence was found among pituitary adenomas (8%, n = 1/12) and schwannomas (0%, n = 0/7). Biopsies of high-grade primary brain tumors showed positive rates of fluorescence similar to those recorded for open resection. No clinical adverse effects associated with use of 5-ALA were observed. Only 1 patient had clinically silent transient elevation of liver enzymes. CONCLUSIONS Study findings suggest that the administration of 5-ALA as a surgical adjunct for resection and biopsy of primary brain tumors and brain metastases is safe. In light of the high rate of positive fluorescence in high-grade gliomas other than glioblastomas, meningiomas, and a variety of metastatic cancers, 5-ALA seems to be a promising tool for enhancing intraoperative identification of neoplastic tissue and optimizing the extent of resection.

Intraoperative magnetic resonance imaging and early prognosis for vision after transsphenoidal surgery for sellar lesions

OBJECT Sellar lesions with suprasellar extension may cause loss of visual acuity and visual field damage due to compression of the optic chiasm. Using intraoperative MR (iMR) imaging to detect symptomatic lesion remnants adjacent to the optic chiasm (that may be resected in the same procedure) may positively affect the functional outcome of patients with these lesions. The aim of this study was to evaluate the correlation between visual improvement and optic nerve decompression detected by iMR imaging in patients undergoing transsphenoidal resection of pituitary lesions. METHODS A total of 32 patients (23 men and 9 women) who underwent transsphenoidal resection of sellar lesions causing visual impairment were included in this study. Tumor volume ranged from 0.9 cm(3) to 55.7 cm(3) (mean 9.8 ± 11.7 cm(3)). Preoperative assessment showed visual field damage in 31 patients (97%) and loss of visual acuity in 28 patients (88%). The latency period between the appearance of symptoms and transsphenoidal decompression was 14.9 ± 19.5 weeks. RESULTS Intraoperative MR imaging was performed after the resection was believed to be complete, or if further tumor removal was not safely possible due to changed conditions in the surgical field. Complete resection was detected on these initial scans in 17 patients (53%). Partial resection was achieved in 9 patients (28%) and tumor debulking in 6 (19%). Additional resection was possible in 8 (53%) of these 15 patients. Four (50%) of these 8 cases had suprasellar remnants and the optic chiasm was subsequently decompressed. In 5 cases optimal decompression of the optic chiasm was not possible. On early follow-up within 1 month after surgery, overall improvement of visual field damage was observed in 27 patients (87%). In 23 patients (74%), the Goldmann perimetry demonstrated complete recovery. Improvement of visual acuity was noted in 24 patients (86%). Eighteen patients (64%) regained full visual acuity. Identification of a decompressed optic chiasm on iMR imaging was significantly correlated with visual field improvement (p = 0.0007; positive predictive value 0.96, 95% CI 0.81-0.99) and relief of visual acuity deficits (p = 0.0002; positive predictive value 0.96, 95% CI 0.79-0.99). Two patients needed transcranial procedures for symptomatic tumor remnants detected on iMR imaging. CONCLUSIONS Intraoperative MR imaging findings correlate with prognosis of visual deficits after transsphenoidal decompression of the anterior optic pathways. The use of iMR imaging may prevent revision surgery for unexpected symptomatic remnants.

Age and salvageability: Analysis of outcome of patients older than 65 years undergoing craniotomy for acute traumatic subdural hematoma

BACKGROUND We are in an aging population and many elderly people are prone to falling and suffering an acute traumatic subdural hematoma (aSDH). Yet, the operative treatment of patients older than 65 years of age for aSDH remains controversial, and very limited data exists with regard to expected outcome in this elderly patient group. METHODS We retrospectively analyzed 37 consecutive patients (all >65 years) who underwent craniotomy for aSDH in our department between January 1, 2002 and December 31, 2007. RESULTS Thirty-seven consecutive patients (54% women, 46% men) were treated for aSDH by means of craniotomy and duraplasty. Median age was 73 years (interquartile range, 10 years). Thirty patients (81%) had significant comorbidities and 43% of patients were treated by anticoagulation or thrombocyte aggregation inhibitors. Median initial Glasgow coma scale score was 8 (interquartile range, 7), and 51% had pupillary abnormalities. Perioperative morbidity occurred in 12 of 37 patients (32%), and 13 patients died in the postoperative period (35%). Overall outcome according to Glasgow outcome scale (GOS) was favorable (GOS, 4 and 5) in 15 of 37 patients (41%); severely disabled (GOS, 3) in 8 of 37 (22%), and unfavorable (GOS, 1 and 2) in 14 of 37 (38%). CONCLUSIONS Craniotomy for patients older than 65 years of age remains controversial, and our case series seems to support the notion that surgical treatment is associated with significant postoperative morbidity, mortality, and adverse outcome. However, selected patients benefit from an intervention, with a good outcome in 41% of patients.

Correlation between jugular bulb oxygen saturation and partial pressure of brain tissue oxygen during CO2 and O2 reactivity tests in severely head-injured patients.

Summary Purpose. To correlate the jugular bulb oxygen saturation (SjvO2) and brain tissue oxygen pressure (PbtO2) during carbon dioxide (CO2) and oxygen (O2) reactivity tests in severely head-injured patients. Methods and Results. In nine patients (7 men, 2 women, age: 26±6.5 years, GCS of 6.5±2.9), a polarographic microcatheter (Clark-type) was inserted into nonlesioned white matter (frontal lobe). PbtO2 and SjvO2 were monitored simultaneously and cerebral vasoreactivity to CO2 and O2 was tested on days three, five and seven after injury. Simultaneous measurements of vasoreactivity by transcranial Doppler (TCD) were undertaken. A total of twenty-one CO2 and O2 reactivity tests were performed. Critical values of PbtO2 (<15 mm Hg) during induced hyperventilation could be observed four times in two patients. High PbtO2 values up to 80 mm Hg were observed during hyperoxygenation (FiO2 100%). CO2 vasoreactivity by means of PbtO2 was absent in four tests in which measurements by TCD showed intact responses. A stronger correlation between SjvO2 and PbtO2 during the O2 reactivity tests was observed (r=0.6, p<0.001), in comparison to values obtained during the CO2 reactivity tests (r=0.33, p<0.001). In addition, there was no statistically significant correlation (r=0.22, p=0.26) between CO2 reactivity values measured by TCD (4.5±5.7%) and PbtO2 (3±2.8%). Conclusions. Correlation between SjvO2 and PbtO2 during CO2 reactivity test is low, even if significant differences between normo- and hyperventilation values are present. In comparison to SjvO2, monitoring of PbtO2 might more accurately detect possible focal ischaemic events during rapidly induced hyperventilation in severely head-injured patients. The CO2 vasoreactivity by means of changes in Vm MCA seems to be higher in comparison to changes of PbtO2. These observations lead to the hypothesis that vasoreactivity measured by TCD overestimates the cerebrovascular response to CO2.

Monitoring of the Inflammatory Response After Aneurysmal Subarachnoid Haemorrhage in the Clinical Setting: Review of Literature and Report of Preliminary Clinical Experience

BACKGROUND Clinical and experimental studies showed a marked inflammatory response in aneurysmal subarachnoid haemorrhage (SAH), and it has been proposed to play a key role in the development of cerebral vasospasm (CVS). Inflammatory response and occurrence of CVS may represent a common pathogenic pathway allowing point of care diagnostics of CVS. Therefore, monitoring of the inflammatory response might be useful in the daily clinical setting of an ICU. The aim of the current report is to give a summary about factors contributing to the complex pathophysiology of inflammatory response in SAH and to discuss possible monitoring modalities. METHODS Review and analysis of the existing literature and definition of own study protocols. RESULTS In cerebrospinal fluid, interleukin (IL)-6 has been found to be significantly higher in patients with CVS during the peri-vasospasm period. While systemic inflammatory response syndrome, high C-reactive protein levels and leukocyte counts has been linked with the occurrence of CVS, less has been reported about cytokines levels in the jugular bulb of the internal jugular vein and in the peripheral blood. Preliminary evaluation of own data suggests, that IL-6 values in the peripheral blood and the arterio-jugular differences of IL-6 are increased with the inflammatory response after SAH. CONCLUSION Monitoring of the inflammatory response, in particular IL-6, might be a useful tool for the daily clinical management of patients with SAH and CVS.