Spinal meningiomas.

Spinal meningiomas (SM) are lesions with a mostly favorable oncological and surgical prognosis and a low incidence of tumor recurrence. SM account for approximately 1.2-12.7% of all meningiomas and 25% of all spinal cord tumors. Typically, SM are located in the intradural extramedullary space. SM grow slowly and spread laterally into the subarachnoid space, stretching and sometimes incorporating the surrounding arachnoid but rarely the pia. Standard treatment is surgery with the primary aims of achieving complete tumor resection as well as improving and recovering neurologic function. Radiotherapy may be considered in case of tumor recurrence, for challenging surgical cases, and for patients with higher-grade lesions (World Health Organization grade 2 or 3); however, radiotherapy is mostly used as an adjuvant therapy for SM. New molecular and genetic profiling increases the understanding of SM and may uncover additional treatment options.

The endogenous neuropeptide calcitonin gene-related peptide after spontaneous subarachnoid hemorrhage-A potential psychoactive prognostic serum biomarker of pain-associated neuropsychological symptoms.

Background: The pronociceptive neuromediator calcitonin gene-related peptide (CGRP) is associated with pain transmission and modulation. After spontaneous subarachnoid hemorrhage (sSAH), the vasodilatory CGRP is excessively released into cerebrospinal fluid (CSF) and serum and modulates psycho-behavioral function. In CSF, the hypersecretion of CGRP subacutely after good-grade sSAH was significantly correlated with an impaired health-related quality of life (hrQoL). Now, we prospectively analyzed the treatment-specific differences in the secretion of endogenous CGRP into serum after good-grade sSAH and its impact on hrQoL. Methods: Twenty-six consecutive patients (f:m = 13:8; mean age 50.6 years) with good-grade sSAH were enrolled (drop out n = 5): n = 9 underwent endovascular aneurysm occlusion, n = 6 microsurgery, and n = 6 patients with perimesencephalic SAH received standardized intensive medical care. Plasma was drawn daily from day 1 to 10, at 3 weeks, and at the 6-month follow-up (FU). CGRP levels were determined with competitive enzyme immunoassay in duplicate serum samples. All patients underwent neuropsychological self-report assessment after the onset of sSAH (t1: day 11-35) and at the FU (t2). Results: During the first 10 days, the mean CGRP levels in serum (0.470 ± 0.10 ng/ml) were significantly lower than the previously analyzed mean CGRP values in CSF (0.662 ± 0.173; p = 0.0001). The mean serum CGRP levels within the first 10 days did not differ significantly from the values at 3 weeks (p = 0.304). At 6 months, the mean serum CGRP value (0.429 ± 0.121 ng/ml) was significantly lower compared to 3 weeks (p = 0.010) and compared to the first 10 days (p = 0.026). Higher mean serum CGRP levels at 3 weeks (p = 0.001) and at 6 months (p = 0.005) correlated with a significantly poorer performance in the item pain, and, at 3 weeks, with a higher symptom burden regarding somatoform syndrome (p = 0.001) at t2. Conclusion: Our study reveals the first insight into the serum levels of endogenous CGRP in good-grade sSAH patients with regard to hrQoL. In serum, upregulated CGRP levels at 3 weeks and 6 months seem to be associated with a poorer mid-term hrQoL in terms of pain. In migraineurs, CGRP receptor antagonists have proven clinical efficacy. Our findings corroborate the potential capacity of CGRP in pain processing.

Incidence of medical and surgical complications after elective lumbar spine surgery.

INTRODUCTION: The demographic change results in an ever increasing number of older patients with pre-existing medical conditions who require spinal surgery, and recovery is often severely impaired by procedure-related complications. The purpose of this retrospective study was to determine patients at risk of medical and surgical complications. METHOD: Using our database, we reviewed 1244 patients with lumbar degenerative disk disease, spinal stenosis, and instability, who had undergone surgery at our department between 2009 and 2014. We screened for medical complications (thromboembolic and cardiac events, pneumonia, and sepsis) and surgical complications (hemorrhage, wound infection, and CSF fistula). Furthermore, a matched 1:1 control group consisted of 103 patients without any surgical and medical complications in the randomly selected period of May 2009 to October 2014. RESULTS: 93 patients (46 women, 47 men), mean age 70 years (range 33-86 years, median 67.4 years), with complications were identified (overall morbidity 7.6 %): 22.6 % (n = 26) had medical complications and 77.4 % (n = 89) surgical complications. In 93 patients (46 females, 47 males), mean age 70 years (range 33-86 years, median 67.4 years), a total of 115 complications were noted (overall morbidity of the 93 patients 7.6 %): 22.6 % (n = 26) medical complications and 77.4 % (n = 89) surgical complications. Age and pre-existing conditions were independently associated with medical complications (p < 0.001). Infections (pneumonia and sepsis) were correlated with multi-segmental interventions (p = 0.009), duration of surgery (p = 0.009), and pre-existing conditions (p = 0.014). Surgical complications were significantly correlated with age (p = 0.016) and duration of surgery (p = 0.014) and occurred significantly more often in patients with instability (p < 0.001). Wound healing disorders were associated with coagulopathy (p = 0.013) and transfusion (p < 0.001). CONCLUSIONS: We identified predictors that help identify patients at risk of medical and surgical complications. These correlations should be taken into account when advising older patients with pre-existing conditions on lumbar spine surgery.

Infectious Spondylodiscitis of the Lumbar Spine: Conservative Antibiotic Therapy vs. Antibiotic Therapy with Surgery, and the Time of Surgery.

Background: Infectious spondylodiscitis of the lumbar spine is a common serious disease for which evidence-based therapeutic concepts are still lacking. Objective: This retrospective study compared the impact of the health status of patients on the length of hospital stay with regard to the treatment concept, i.e., antibiotic therapy or antibiotic therapy in combination with fixation surgery. Patients and Methods: The study included 54 consecutive patients with infectious spondylodiscitis of the lumbar spine who had been treated at our clinic between 2004 and 2013. Records included patient demographics, concomitant diseases, the neurological status and treatment modality, and the length of hospital stay. Results: 40 men and 14 women with a mean age of 64.2 (30-89) years were included. 13 patients were only treated with antibiotics (group A), 7 patients with abscess decompression (group B), 18 patients with early dorsal fusion (<10 days after admission) (group C), and 16 patients with late dorsal fusion (≥10 days after admission; group D). Patients undergoing early dorsal fusion had a significantly shorter hospital stay (33.2 days) than patients undergoing late dorsal fusion (57.0 days), P = 0.016. Mean hospital stay of patients treated with antibiotics was 30.3 days, that of patients receiving abscess decompression 57.8 days. Patients receiving only antibiotics had a significantly lower CRP level at admission than patients undergoing early fusion, P < 0.05. Conclusion: Patients with one or more relevant chronic concomitant diseases showed faster recovery, shorter hospital stays, and earlier return to daily routine after early dorsal fusion than after late dorsal fusion or abscess evacuation alone.

Development of cerebrospinal fluid fistula after incidental durotomy in spinal decompression surgery.

BACKGROUND: Incidental durotomy (ID) during spinal surgery is a risk factor for the development of cerebrospinal fluid (CSF) fistula. The rates of ID with or without consecutive CSF fistula vary according to the extent of the surgical procedure. Revision surgery has the highest rates of dural tears. However, not every case of ID leads to CSF fistula requiring revision surgery. The objective of this study was to analyze the predictors for the development of CSF fistula after ID. METHODS: This retrospective study included 6024 consecutive patients who had been surgically treated for degenerative spinal disease at our clinic over the past 15 years. Patients who had undergone surgical revision for CSF fistula were assigned to the CSF fistula group. A matched 3:1 control group (ID group) was formed of patients with ID but without CSF fistula. Charts, surgical reports, and radiographic data were reviewed and statistically analyzed for demographics, duration of symptoms, comorbidities, surgical strategy, and pre- and postoperative neurological performance. RESULTS: The 15-year incidence of CSF fistula in the overall population was 0.36% (N.=22). The following locations were affected: N.=18 lumbar (81.8%), N.=2 cervical (9.1%), and N.=2 thoracic (9.1%). The extent of ID was similar in both groups. The two groups did not significantly differ with regard to the intraoperative management of dural repair with primary suturing (P=0.345), dural patches, sealant, or collagen matrix (P=0.228; P=0.081; P=0.081). In the postoperative period, bed rest in supine position for 48 hours (P=0.037) and laxative therapy (P=0.034) were the most beneficial treatment modalities for preventing CSF fistula. Patients with CSF fistula were hospitalized significantly longer (21 days vs. 10 days in the control group; P<0.001). CONCLUSIONS: This large test group showed a low incidence of postoperative CSF fistula after intraoperative ID. Bed rest and laxative treatment were important approaches to preventing CSF fistula.

Neurological outcome after resection of spinal schwannoma.

INTRODUCTION: Spinal schwannoma (SS) is the most frequently diagnosed benign spinal tumor, constituting approximately 25 % of all intradural tumors. Aim of our study was to identify factors that potentially affect immediate postoperative neurological outcome, and the rate of functional recovery within 12 months. METHODS: Screening of our institutional database yielded 90 consecutive patients (mean age 57.1 years, 39 women [43.3 %]) with newly diagnosed SS between March 1997 and October 2018. We pre- and postoperatively reviewed patient charts, surgical reports, radiographic data, use of IOM, duration of symptoms, histopathology, co-morbidities, radiographic extension, surgical strategy, neurological performance (Japanese Orthopedic Association Score [JOA score] and Frankel Grade Classification). RESULTS: Mean duration of preoperative symptoms was 3.6 ± 1.6 months. Most common symptoms were local pain (n = 77, 85.6 %). Macroscopic complete resection was achieved in 84 patients (93.3 %). During follow-up, complete recovery from local pain was documented for 41 patients (59.7 %), from radiating pain for 41 (69.5 %; p < 0.001). Postoperatively, 25 (27.7 %) patients developed a new neurological deficit (motor deficits n = 3 and sensory deficits n = 23; one patient developed both); after 12 months, however, motor deficits had abated in all patients, and 16 (69.5 %) patients had completely recovered from sensory deficits. Use of intraoperative monitoring (IOM) was a significant predictor for good functional outcome (p < 0.001). CONCLUSION: Resection of SS accompanied by IOM whenever feasible should be advocated. We achieved a high number of complete resections with a low rate of morbidity. New postoperative motor or sensory deficits had a very high rate of complete recovery within 12 months.

Functional outcome after surgical treatment of spinal meningioma.

OBJECTIVE: Space-occupying spinal meningiomas (SM), commonly diagnosed due to gradual neurological deterioration, are treated surgically by decompression and tumor resection. In this series of patients with surgically treated SM, we determined individual predictors of functional outcome in the context of intraoperative neuromonitoring (IOM). METHODS: This retrospective study included 45 patients (39 women, 6 men; mean age 63 years). We reviewed pre- and postoperative charts, surgical reports, radiographic data for demographics, use of IOM, duration of symptoms, histopathology, co-morbidities, radiographic extension, surgical strategy, neurological performance (Japanese Orthopedic Association Score [JOA score]. Median follow-up was 34 months (12-190 months). RESULTS: Most frequent surgical approaches were laminectomy (71.1%, n = 32) and hemi-laminectomy (28.9%, n = 13). Predominant SM site was the thoracic spine (55.6%, n = 25). Most common symptoms were sensory deficits (77.8%, n = 35), gait disorders (55.6%, n = 25), motor deficits (42.2%, n = 19), and radiating pain (37.8%, n = 17). Simpson grade 1 resection was achieved in 6 patients, most common type of resection was Simpson grade 2 in 36 patients. During follow-up, 80.0% of patients had fully recovered sensory deficits (p < 0.001), 76.0% of patients with preoperative gait disorders had been asymptomatic (p < 0.001), and motor deficits in 12/19 (63.1%). Pain had decreased significantly from admission to follow-up (p = 0.001). IOM was used in 20 (44.4%) patients. Postoperatively, 6(13.3%) patients had developed a new neurological deficit, 4 of them operated without IOM. CONCLUSION: Resection of SM with IOM showed good recovery, excellent functional results with low surgical morbidity.

Symptomatic Postoperative Spinal Epidural Hematoma after Spinal Decompression Surgery: Prevalence, Risk Factors, and Functional Outcome.

OBJECTIVE: Postoperative spinal epidural hematoma (pSEH) with symptomatic compression of nervous structures after spinal decompression surgery is a rare complication. Delayed evacuation may result in severe neurologic impairment. We present a large single-center analysis of the prevalence, potential risk factors, and functional recovery after pSEH. METHODS: A retrospective review of our institutional database of spinal decompression surgery over 15 years yielded 6,024 consecutive patients. A total of 42 patients who had undergone surgical revision due to postoperative neurologic deterioration or intractable radiating pain and radiographically confirmed pSEH were allocated to the pSEH group. A matched 3:1 control group was formed (126 patients with the same surgical procedure, same year, same sex, and similar age). Charts, surgical reports, and radiographic data were reviewed for demographics, duration of symptoms, history of medical treatment, medication, comorbidities, radiographic extension, surgical strategy, and pre- and postoperative neurologic performance. Median follow-up was 3 months. Risk factors for pSEH, complete recovery, and recovery of neurologic symptoms were analyzed with univariable and multivariable logistic regression models. RESULTS: The prevalence of pSEH in this population was 0.69% (n = 42) with these locations: 7 of 1,284 (0.54%) cervical, 1 of 774 (0.12%) thoracic, and 34 of 3,966 (0.85%) lumbar. Use of anticoagulants (p = 0.003), pathologic coagulation values in the preoperative blood test (p = 0.034), and cigarette smoking (p = 0.003) were identified as independent risk factors of pSEH. Surgery in more than one level showed a trend toward an increased risk of pSEH. Pain as the only symptom (p = 0.0001) was a significant predictor of complete recovery. Patients symptomatic with paraplegia (p = 0.026) had a significantly higher risk of a poor neurologic outcome without full recovery of neurologic symptoms. CONCLUSION: The prevalence of pSEH was lower than previously reported incidences. Use of anticoagulants, pathologic coagulation values, and cigarette smoking were identified as independent risk factors of pSEH. Functional outcome was related to the duration between hematoma evacuation and the clinical presentation of symptomatic pSEH.

Degenerative symptomatic spinal synovial cysts: Clinical presentation and functional outcome.

Spinal synovial cysts (SSC) are a rare but important differential diagnosis for degenerative or space-occupying spinal lesions. There is controversy about the most beneficial treatment, which can be conservative or surgical. We provide a review of our surgical data for purposes of quality assessment and improvement. 5313 patients with surgically treated degenerative spinal diseases were analyzed retrospectively. The incidence of SSC was 1.14%. 61 patients (31 women, 30 men; mean age 65.3 years) with SSC were included in this study. The charts, surgical reports, and radiographic data were reviewed for demographics, duration of symptoms, size of SSC, anatomical site, surgical approach, Visual Analog Scale (VAS), and neurological performance including the Japanese Orthopedic Association Score (JOA score) and the Frankel score. Laminotomy was the most common surgical approach in 93.4% of the patients followed by hemilaminectomy in 6.6%. The predominant site of SSC was the lumbar spine in 86.9%. 95.1% had experienced local and radicular pain as the predominant symptom and 47.5% preoperative sensory and motor deficits. At discharge, the JOA score was significantly increased compared to admission (median value of 17). At follow-up, 94.4% had normal neurological function and 5.6% showed grade 1 neurological deficits. Leg pain had decreased in 94.4% and back pain in 70.6%. At long-term follow-up, all patients presented neurologically stable. The median value for pain classified with the VAS had decreased from 6 at admission to 1 at long-term follow-up. During long-term follow-up, 6 patients (9.8%) had developed spinal instability requiring stabilization, 5 patients had received facet joint infiltration due to symptomatic facet joint syndrome. The epidemiological and clinical patterns of symptomatic SSC are similar to those of other degenerative spinal diseases. Thus, SSC should always be considered as a rare but important differential diagnosis. Surgical outcome was excellent with immediate symptom relief and recovery, which further improved over time. Our data support the benefit of surgical treatment and may be useful in recommending neurosurgical therapy to patients with SSC.

Effect of surgical decompression of spinal metastases in acute treatment - Predictors of neurological outcome.

OBJECTIVE: Space-occupying spinal metastases (SM), commonly diagnosed because of acute neurological deterioration, consequently lead to immediate decompression with tumor removal or debulking. In this study, we analyzed a series of patients with surgically treated spinal metastases and explicitly sought to determine individual predictors of functional outcome. PATIENTS AND METHODS: 94 patients (26 women, 68 men; mean age 64.0 years) with spinal metastases, who had been surgically treated at our department, were included retrospectively. We reviewed the pre- and postoperative charts, surgical reports, radiographic data for demographics, duration of symptoms, histopathology, stage of systemic disease, co-morbidities, radiographic extension, surgical strategy, neurological performance (Frankel Grade Classification), and the Karnofsky Performance Index (KPI). RESULTS: Emergency surgery within <24 h after discharge had been conducted in 33% of patients. Prostate carcinoma (29.5%) and breast carcinoma (11.6%) were the most common histopathologies. Median KPI was 60% at admission that had significantly improved at discharge (KPI 70%; p = 0.01). The rate of complications without revision was 4.3%, the revision rate 4.2%. From admission to discharge, pain had been significantly reduced (p = 0.019) and motor deficits significantly improved (p = 0.003). KPI had been significantly improved during in-hospital treatment (median 60 vs 70, p = 0.010). In the multivariable analysis, predictors of poor outcome (KPI < 70) were male sex, multiple metastases, and pre-existing bowel and bladder dysfunction. Median follow up was 2 months. DISCUSSION: In our series, surgery for spinal metastases (laminectomy, tumor removal, and mass reduction) significantly reduced pain as well as sensory and motor deficits. We identified male sex, multiple metastases, and pre-existing bowel and bladder dysfunction as predictors of negative outcome.

Outcomes of Cranioplasty with Preformed Titanium versus Freehand Molded Polymethylmethacrylate Implants.

OBJECTIVE: Cranioplasty reshapes the neurocranium and viscerocranium after craniectomy. Different materials have been used for cranioplasty. However, no consistent data are yet available comparing these different materials regarding indications, complications, and outcome. We report our experience with preformed titanium implants and freehand molded polymethylmethacrylate (PMMA) implants for cranioplasty. METHODS: This retrospective single-center analysis included 120 consecutive cranioplasty patients who had been operated between 2006 and 2013. A total of 60 patients (27 women, 33 men; mean age: 54 years) had received a preformed titanium implant and 60 patients (22 women, 38 men; mean age: 46 years) a freehand molded PMMA implant. We evaluated all demographic and procedure-related data, indications, and outcome. The longest follow-up was 5.5 years. RESULTS: The most frequent indications for cranioplasty were trauma (n = 48 [40%]), malignant infarction (n = 27 [23%]), tumor (n = 22 [18%]), spontaneous intracerebral or aneurysmal subarachnoid hemorrhage (n = 16 [13%]), revision surgery (n = 5 [4%]), and empyema (n = 2 [2%]). PMMA implants were more often associated with wound-healing disorders (p < 0.023; odds ratio [OR]: 10.53) and epidural hematoma (p < 0.03; OR: 8.46), resulting in a significantly higher re-operation rate (p < 0.005). Precise fitting was radiologically confirmed in 98% of titanium implants but in only 71% of PMMA implants (p < 0.001). Magnetic resonance imaging of patients with titanium implants (n = 4) did not show any relevant artifacts. CONCLUSION: Cranioplasty with preformed titanium implants seems to be superior to freehand molded PMMA implants regarding surgical morbidity, revision rate, and aesthetic results.

Fluorescein sodium-guided resection of cerebral metastases-an update.

BACKGROUND: Cerebral metastasis (CM) is the most common malignancy affecting the brain. In patients eligible for surgery, complete tumor removal is the most important predictor of overall survival and neurological outcome. The emergence of surgical microscopes fitted with a fluorescein-specific filter have facilitated fluorescein-guided microsurgery and identification of tumor tissue. In 2012, we started evaluating fluorescein (FL) with the dedicated microscope filter in cerebral metastases (CM). After describing the treatment results of our first 30 patients, we now retrospectively report on 95 patients. METHODS: Ninety-five patients with CM of different primary cancers were included (47 women, 48 men, mean age, 60 years, range, 25-85 years); 5 mg/kg bodyweight of FL was intravenously injected at induction of anesthesia. A YELLOW 560-nm filter (Pentero 900, ZEISS Meditec, Germany) was used for microsurgical tumor resection and resection control. The extent of resection (EOR) was assessed by means of early postoperative contrast-enhanced MRI and the grade of fluorescent staining as described in the surgical reports. Furthermore, we evaluated information on neurological outcome and surgical complications as well as any adverse events. RESULTS: Ninety patients (95%) showed bright fluorescent staining that markedly enhanced tumor visibility. Five patients (5%); three with adenocarcinoma of the lung, one with melanoma of the skin, and one with renal cell carcinoma) showed insufficient FL staining. Thirteen patients (14%) showed residual tumor tissue on the postoperative MRI. Additionally, the MRI of three patients did not confirm complete resection beyond doubt. Thus, gross-total resection had been achieved in 83% (n = 79) of patients. No adverse events were registered during the postoperative course. CONCLUSIONS: FL and the YELLOW 560-nm filter are safe and feasible tools for increasing the EOR in patients with CM. Further prospective evaluation of the FL-guided technique in CM-surgery is in planning.

Fluorescein Sodium-Guided Surgery of Malignant Brain Tumors: History, Current Concepts, and Future Project.

Fluorescein sodium (FL)-guided resection has become an important and beneficial treatment method for malignant brain tumors. FL-guided resection improves the rate of gross total resection in high-grade gliomas (HGG) and cerebral metastases (CM). FL sensitively visualizes the disruption of the blood-brain barrier in the area surrounding malignant lesions, similar to contrast-enhanced T1-weighted MR sequences. This review of the current literature summarizes the history of FL in neurosurgery from 1946 until today. We discuss the molecular mechanism of FL accumulation in cerebral malignant tumors and provide an overview of the current practice of using FL and applying a dedicated surgical microscope filter. Additionally, we outline and discuss ongoing trials and future projects.

Fluorescein sodium-guided surgery in cerebral lymphoma.

OBJECTIVES: Growth and progress of primary central nervous lymphoma (PCNSL) severely disrupt the blood brain barrier (BBB). Such disruptions can be intraoperatively visualized by injecting fluorescein sodium (FL) and applying a YELLOW 560 nm surgical microscope filter. Here, we report a small cohort of patients with PCNSL that mimicked high grade gliomas (HGG) or cerebral metastases (CM), who had been operated on with the use of FL. PATIENTS AND METHODS: Retrospectively, seven patients with PCNSL were identified, who had been operated on by means of microsurgery after intravenous FL injection. The surgical reports were screened for statements on the grade of fluorescent staining in the tumor area. One representative case was chosen to show the staining under white light as well as under filtered light at different distances to the tumor area. RESULTS: All patients had shown bright and homogenous fluorescent staining of the tumor (n=7. 100%). No adverse effects had been observed. CONCLUSION: Similar to patients with HGG or CM, patients with PCNSL may benefit from use of FL and the dedicated YELLOW 560 nm filter in open surgery.

Fluorescein sodium-guided resection of cerebral metastases­experience with the first 30 patients.

BACKGROUND: Surgical resection is a key element of the multidisciplinary treatment of cerebral metastases (CMs). Recent studies have highlighted the importance of complete resection of CMs for improving recurrence-free and overall survival rates. This study presents the first data on the use of fluorescein sodium (FL) under the dedicated surgical microscope filter YELLOW 560 nm (Zeiss Meditec, Germany) in patients with CM. METHODS: Thirty patients with CMs of different primary cancers were included (15 females, 15 males; mean age 61.1 years); 200 mg of FL was intravenously injected directly before CM resection. A YELLOW 560 nm filter was used for microsurgical tumor resection and resection control. Surgical reports were evaluated regarding the degree of fluorescent staining, postoperative MRIs regarding the extent of resection [gadolinium (Gd)-enhanced T1-weighted sequence] and the postoperative courses regarding any adverse effects. RESULTS: Most patients (90.0%, n = 27) showed bright fluorescent staining, which markedly enhanced tumor visibility. Three patients (10.0%) (two with adenocarcinoma of the lung and one with melanoma of the skin) showed no or only insufficient FL staining. Another three patients (10.0%) showed residual tumor tissue in the postoperative MRI examination. In two other patients, radiographic examination could not exclude the possibility of very small areas of residual tumor tissue. Thus, gross-total resection was achieved in 83.3% (n = 25) of patients. No adverse effects were registered over the postoperative course. CONCLUSIONS: FL and the YELLOW 560 nm filter are safe and practical tools for the resection of CM, but further prospective research is needed to confirm that this advanced technique will improve the quality of CM resection.

Sodium fluorescein-guided resection under the YELLOW 560 nm surgical microscope filter in malignant brain tumor surgery--a feasibility study.

OBJECTIVE: In glioma surgery, the extent of resection (EOR) is one important predictor of progression-free survival. In 2006, fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) was shown to improve the EOR in malignant gliomas. However, the use of 5-ALA is complex and causes certain side effects. Sodium fluorescein (FL) is a fluorescent dye that is used for angiography in ophthalmic surgery. FL accumulates in areas of the disturbed blood-brain barrier and can be visualized under a 560-nm wavelength fluorescent light source (YELLOW 560 nm, Carl Zeiss Meditec, Oberkochen, Germany). Here, we present the first experiences with low-dose FL and YELLOW 560 nm in 35 patients with malignant brain tumors. PATIENTS AND METHOD: A total of 200 mg of FL (3-4 mg/kg bodyweight) was administered in 35 patients during craniotomy as an off-label use between May and August 2012. We retrospectively analyzed the histology, pre-treatment, clinical parameters pre- and postoperatively and occurrence of any adverse effects. The feasibility and efficacy ('helpful,' 'not helpful') of FL under YELLOW 560 nm (demarcation of the tumor margin) was assessed by the responsible neurosurgeon (n = 5) for each surgical procedure. RESULTS: Twenty-six patients had gliomas (1 WHO grade I, 3 WHO grade II, 5 WHO grade III, 17 WHO grade IV), 5 patients had cerebral metastases, 2 had non-malignant astrogliosis and 2 had post-radiation necrosis. The fluorescence signal was detected in all patients immediately after the FL administration. FL application was classified as 'helpful' in 28 patients, implying improved visualization of the tumor margins. The intensity of the fluorescence signal seemed to be correlated to the histology and was strongly dependent on the pre-treatment status. We did not record any allergic reactions or any other adverse effects. CONCLUSION: The use of FL for the resection of brain tumors is safe and feasible. Presumably, the visualization of the tumor margin depends on the histopathology and on the pre-treatment status. A randomized evaluation of FL under the YELLOW 560 nm filter is planned to prospectively analyze the extent of resection in patients with malignant brain tumors.