Prognostic significance of immunohistochemical expression of VEGFR2 and iNOS in spinal chordoma.

PURPOSE: To clarify whether vascular endothelial growth factor receptor 2 (VEGFR2) and inducible nitric oxide synthase (iNOS) are involved in the angiogenesis and recurrence of spinal chordoma tissues and influence the overall survival. METHODS: All patients affected by a spinal chordoma surgically treated between 1986 and 2007 were reviewed. We examined the expression of VEGFR2 and iNOS with immunohistochemistry using a tissue microarray containing 120 chordoma samples. Local recurrence and overall survival (OS) were analyzed. RESULTS: A series of 40 chordoma patients who underwent surgery for a total of 120 lesions (including 80 recurrent lesions) were identified (sacrum 77.5 %, lumbar spine 17.5 %, cervical/thoracic spine 5 %). Surgical margins were wide in 30 (75 %), marginal in 8 (20 %) and intralesional in 2 (5 %) patients. Median follow-up was 120 months. The 5- and 10-year OS of the entire series of patients was 78.6 and 30 %, respectively. There were five primary chordomas (12.5 %) with moderate and 35 (87.5 %) with strong expression of VEGFR-2. All recurrent spinal chordomas displayed strong expression of VEGFR-2. The expression of iNOS was predominately moderate to high in primary chordomas: There were 15 tumors (37.5 %) with moderate and 25 tumors (62.5 %) with strong expression. All recurrent chordomas displayed strong expression of iNOS. CONCLUSION: The high expression of VEGFR-2 and iNOS affected the OS. The OS at 10 years was only 30 %.

Expression of PDGFR-α, EGFR and c-MET in spinal chordoma: a series of 52 patients.

AIM: To investigate the expression of platelet-derived growth factor (PDGF) receptor-A (PDGFRα), epidermal growth factor receptor (EGFR) and c-Met in spinal chordoma. To the authors' knowledge, little is known regarding the prognostic significance of receptor tyrosine kinase in spinal chordoma. MATERIALS AND METHODS: Using immunohistochemical techniques, the authors investigated PDGFR-α, EGFR and c-MET expression in 52 primary and 104 recurrent lesions, and compared these data with clinicopathological parameters. RESULTS: PDGFR-α, EGFR and c-MET were found to be expressed in 75.0%, 83% and 77% of primary, and in 97.0% of recurrent lesions in all investigated receptor tyrosine kinases. Higher PDGFR-α and c-MET expression was found to be correlated with younger patient age. Lesions with a higher expression of PDGFR-α demonstrated significantly higher EGFR scores in both primary and recurrent lesions compared to those with lower PDGFR-α expression. In recurrent lesions, higher c-MET expression was found to be associated with significantly better prognosis than those with lower c-MET expression (p=0.033). Lesions with a higher level of PDGFR-α expression were found to have significantly poorer prognosis than those with lower PDGFR-α expression (p=0.024). Those patients with lower EGFR expression were found to have significantly better prognosis than those with higher EGFR expression (p=0.005). CONCLUSION: In the current study, c-MET expression in patients with spinal chordoma was found to be correlated with a younger patient age and a favorable prognosis. Patients with a higher level of PDGFR-α and EGFR expression were found to have a significantly poorer prognosis than those with lower PDGFR-α and EGFR expression.

Endoscopic endonasal transsphenoidal approach to sellar lesions: a detailed account of our mononostril technique.

Objective The endonasal endoscopic approach is currently under investigation for perisellar tumor surgery. A higher resection rate is to be expected and nasal complications should be minimized. Here, the authors report their technique of transnasal endoscopic neurosurgery after 218 procedures. Methods Between October 2000 and September 2011, 210 patients received 218 endoscopic endonasal transsphenoidal procedures for perisellar lesions. Procedures were video recorded. The surgical technique was carefully analyzed. These cases were prospectively followed. Results Standard technique was mononostril approach with 0-degree optics. 30-degree and-after availability-45-degree optics were used for assessment of radicality. On follow-up, magnetic resonance imaging revealed radical tumor resection in 94 out of 104 cases (90.3%). Recurrent tumor growth was observed in five younger patients (2.2%). There was no mortality and a low complication rate. Three patients (1.4%) complained postoperatively of nasal congestion or reduced nasal air flow; however, no complaints were considered to be severe. Conclusion In comparison with other literature reports, the results are comparable or even better with respect to surgical radicality. The very low rate of nasal complaints is particularly remarkable. The technique has been shown to be safe and successful with a high radicality and only minor complications.

Waterjet dissection of the vestibulocochlear nerve: an experimental study.

OBJECT: Waterjet dissection has been shown to protect intracerebral vessels, but no experience exists in applying this modality to the cranial nerves. To evaluate its potential, the authors examined waterjet dissection of the vestibulocochlear nerve in rats. METHODS: Lateral suboccipital craniectomy and microsurgical preparation of the vestibulocochlear nerve were performed in 42 rats. Water pressures of 2-10 bar were applied, and the effect was microscopically evaluated. Auditory brainstem responses (ABRs) were used to define nerve function compared with preoperative values and the healthy contralateral side. The final anatomical preparation documented the morphological and histological effects of waterjet pressure on the nerve. RESULTS: In using up to 6 bar, the cochlear nerve was preserved in all cases. Eight bar moderately damaged the nerve surface. A 10-bar jet markedly damaged or even completely dissected the nerve. Time course analysis of the ABR demonstrated complete functional nerve preservation up to 6 bar after 6 weeks in all rats. Waterjet dissection with 8 bar was associated with a 60% recovery of ABR. In the 10-bar group, no recovery was seen. CONCLUSIONS: Microsurgical dissection of cranial nerves is possible using waterjet dissection while preserving both morphology and function. The aforementioned jet pressures are known to be effective in neurosurgical treatment of tumors. Thus, waterjet dissection may be useful in skull base surgery including dissection of cranial nerves from tumors. Further studies on this subject are encouraged.

Ultrasonic aspiration in neuroendoscopy: first results with a new tool.

Neuroendoscopic techniques are often considered inapplicable to lesion resection because most lesions are too large for effective endoscopic resection in an appropriate time frame. To evaluate the potential of ultrasonic aspiration in neuroendoscopic procedures, the authors developed a new handpiece for endoscopic application. The instrument was subsequently tested in 10 cadaveric pig brains and applied in 5 clinical cases. In the pig brain, a precise and accurate aspiration of ventricular ependyma and brain parenchyma was obtained. Clinically, the device was applied in 3 patients with obstructive hydrocephalus, and via an endonasal transsphenoidal approach in 2 patients with pituitary macroadenomas. In all cases, the lesion was effectively aspirated without complications. Ultrasonic aspiration can be applied safely and successfully in selected endoscopic procedures. The use of this technique could expand the indications for endoscopic approaches to include intraventricular lesions and in minimally invasive transsphenoidal endonasal approaches.

Waterjet dissection versus ultrasonic aspiration in epilepsy surgery.

OBJECTIVE: Waterjet dissection is currently under close investigation in neurosurgery. Experimentally, precise brain parenchyma dissection with vessel preservation has been demonstrated. Clinically, the safety of the instrument has already been proved. However, precise data demonstrating that waterjet dissection indeed reduces surgical blood loss are still missing. METHODS: The authors applied the waterjet device in a prospective randomized study in comparison with the ultrasonic aspirator. Because there is little variability in the procedure, 30 patients with temporal lobe epilepsy receiving a tailored temporal lobe resection between December 1999 and October 2002 were selected for this study. Intraoperative vessel preservation, intraoperative blood loss, surgical complications, and epilepsy outcome were evaluated. All patients were followed at 3-month intervals. RESULTS: During surgery, both instruments were easy to handle. Only with the waterjet dissector, however, were even small intraparenchymal blood vessels preserved. Intraoperative blood loss was significantly reduced with the waterjet (mean, 70 +/- 46 ml) compared with the ultrasonic aspirator (mean, 121 +/- 48 ml). However, no difference in the necessity for blood transfusion occurred. No difference was observed with respect to operation time (238.6 +/- 37.0 min with the waterjet, 247.5 +/- 41.5 min with the ultrasonic aspirator), surgical complications, and outcome. CONCLUSION: The waterjet dissector enables a significant reduction of intraoperative blood loss in the investigated setting. However, further studies are needed to confirm these results with a larger number of patients. Studies also are needed to prove that the reduction of blood loss is of clinical relevance for the outcome of the patients.

Prognosis of gliomas in the 1970s and today.

The benefit of the current strategy for diagnosis (magnetic resonance, [MR] imaging) and treatment (surgery, chemotherapy, radiotherapy) of gliomas, in contrast to the standard treatment in use before MR imaging and the microsurgical era, has not yet been determined. A retrospective statistical analysis was performed for all patients with glioma who underwent surgery at a single institution between 1965 and 1974 (Group I, 88 patients) or 1986 and 1995 (Group II, 249 patients). There were no major differences in symptomatology, tumor localization, and number of surgical procedures. The mean time until tumor diagnosis was significantly shorter in Group II (Group I, 48 weeks; Group II, 19.5 weeks). Also, the mean time from initial symptoms to surgery was significantly shorter for high-grade gliomas in Group II (Group I, 16.3 weeks; Group II, 11.7 weeks). For high- as well as low-grade gliomas, there was a clear reduction of the perioperative morbidity and mortality rates in Group II. Nevertheless, for the postoperative duration of survival, no significant differences were demonstrated for high- or low-grade gliomas. Based on the results of this study, the perioperative morbidity and mortality rate as well as the time from diagnosis to treatment have been remarkably reduced within the last 30 years. Nevertheless, the overall prognosis for patients with gliomas has not changed from the 1970s until today. Thus, the introduction of modern diagnostic modalities and surgical procedures has not improved the outcome in patients with glioma. Further research to improve the treatment of this disease is urgently needed.

Neuronavigation and complication rate in epilepsy surgery.

The role of neuronavigation for complications in temporal lobe epilepsy surgery was evaluated. Thirty-seven patients operated on with neuronavigation (group N: 38 operations; mean age 33.9 years; etiology: cryptogenetic 31, symptomatic 7; lateralization: 22 right, 16 left) and 22 patients operated on without neuronavigation (group NN: 23 operations; mean age 29.7 years; etiology: cryptogenetic 9, symptomatic 14; lateralization: 13 right; 10 left) were analyzed. The minimal follow-up time was 2 years. There was a clear difference in the number of complications (N 7.9%; NN 21.7%), which consisted of hemiparesis (N: 1; NN: 2), cranial nerve palsy (N: 1; NN: 2), aphasia (N: 1; NN: 0), and postoperative infection (N: 0; NN: 1). In addition, there was a reduced need for temporal re-resection after intraoperative electrocorticography (N 30.6%; NN 47.1%). Operation time (N: 239+/-9.4 min; NN: 208+/-12.1 min), duration of postoperative in-hospital and in-ICU stay [N: 16.9+/-1.1 days (1.0+/-0.0 days); NN: 17.2+/-2.8 days (1.1+/-0.1 days)], extension of temporal lobe resection from polar (N: 41.2+/-1.5 cm; NN: 42.9+/-3.9 cm), and postoperative seizure frequency reduction (N 90.4%; NN 94.7%) were not different. Because of the trend towards a reduction of complications and re-resections after electrocorticography, the authors recommend neuronavigation despite its higher costs as an additional tool in epilepsy surgery.

Comparison of waterjet dissection and ultrasonic aspiration: an in vivo study in the rabbit brain.

OBJECT: The waterjet method of dissection has been shown to enable the precise dissection of the parenchyma vessels while preserving blood in cadaveric pig brains. The waterjet device has also been applied clinically to treat various diseases and disorders without complications. Evidence still remains to be gathered as to how the instrument performs in reducing surgical trauma, intraoperative blood loss, and postsurgical brain edema. In the present study the authors investigate these parameters in a comparison between waterjet dissection and ultrasonic aspiration in the rabbit brain in vivo. METHODS: Thirty-one rabbits received identical bilateral frontal corticotomies, which were created using the waterjet device or an ultrasonic aspirator. The animals were killed 1, 3, or 7 days, or 6 weeks after surgery and their brains were processed for immunohistological analysis. Blood vessel preservation, intraoperative hemorrhage, postsurgical brain edema, and posttraumatic microglial and astoglial reactions were evaluated. Only in animals subjected to waterjet dissection were preserved vessels observed within the corticotomies. In addition, less intraoperative bleeding occurred in animals in which the waterjet was used. The microglial reaction was significantly reduced by waterjet dissection compared with ultrasonic aspiration; however, no difference in edema formation or astrocytic reactivity was observed. CONCLUSIONS: These results demonstrate that waterjet dissection appears to be less traumatic than ultrasonic aspiration with respect to intraoperative hemorrhage and postoperative microglial reactivity in the rabbit model. Nevertheless, no difference in edema formation could be demonstrated. It remains to be proven that the observed differences are of clinical relevance.

Waterjet dissection in the brain: review of the experimental and clinical data with special reference to meningioma surgery.

Waterjet dissection enables precise parenchymal dissection under preservation of vessels and reduction of intraoperative blood loss in general surgery. The present study reports our experimental and clinical results with this device in neurosurgery. Our experimental studies in the porcine cadaver brain show that the device allows very accurate, precise, and reliable dissection of the brain. A linear relationship between waterjet pressure and dissection depth was demonstrated. Vessel preservation was observed at pressures below 20 bar. Clinically, precise dissection of brain parenchyma and various tumors was performed without complications. Even in meningiomas, with their very variable firmness, vascularization, and adherence to the surrounding brain, accurate dissection could be achieved. However, while tumor separation from the brain was attained with high accuracy and vessel preservation in all cases, only in softer lesions resection by aspiration under vessel preservation was possible with pressures below 20 bar. In all, the waterjet device enables precise tissue dissection and vessel preservation in various pathologies including meningiomas. It could represent an addition to the neurosurgical armamentarium. Further studies will have to show dissection qualities of this device that are superior to conventional methods.

Water jet dissection in neurosurgery: experimental results in the porcine cadaveric brain.

OBJECTIVE: Water jet dissection is currently under investigation as a new tool for use in neurosurgical procedures. The safety of this instrument has already been demonstrated. However, precise data demonstrating highly accurate tissue dissection in the brain in combination with vessel preservation are still missing. METHODS: In this study, 50 porcine cadaveric brains were dissected with the use of several nozzle types (80-150 in microm diameter, coherent straight or helically turned jet) and several levels of water jet pressure (1-40 bars). The dissection characteristics in various brain regions and the basilar artery were evaluated morphologically. RESULTS: The best results regarding reliable function, dissection accuracy, and the correlation of water jet pressure with dissection depth were obtained with the 120-microm Helix Hydro-Jet nozzle. An almost linear relationship of pressure increase with dissection depth was demonstrated. The dissection depth varied significantly up to threefold, depending on the area investigated (greatest resistance was in the brainstem, followed by hemispheres and then the cerebellum). Vessels including the basilar artery resisted pressure up to 15 bars in most cases, whereas the basilar artery was dissected significantly more often with higher pressure. CONCLUSION: The results indicate that 1) use of the water jet enables very precise and reliable brain parenchyma dissection with vessel preservation under conditions corresponding to the clinical situation, and 2) the nozzle type and water jet pressure must be selected carefully according to the brain area and tissue targeted. This study provides the morphological basis for further research with the use of the water jet technique in the brain. The water jet's characteristics may make this device a useful addition to the neurosurgical armamentarium.

Waterjet dissection in neurosurgical procedures: clinical results in 35 patients.

OBJECT: Waterjet dissection represents a new minimally traumatic surgical method for dissection that can be used in various parenchymal organs, in which it allows highly precise parenchymal dissection while preserving blood vessels, resulting in reduced intraoperative blood loss. This study was performed to investigate the clinical application of this new technique in neurosurgical procedures, such as brain tumor resection and epilepsy surgery. METHODS: Thirty-four patients with gliomas (Grades II-IV), cerebral metastases, temporal lobe epilepsy, or cerebellar hemangioblastomas, and one patient with internal carotid artery (ICA) stenosis were treated surgically with the aid of the waterjet. Resection was performed using waterjet dissection in combination with conventional neurosurgical procedures. Intraoperatively, the waterjet was easy to handle, and no complications due to the device were observed. Dissection of tissue was possible for all pathological conditions, and pressures between 3 and 45 bars were used. In gliomas, metastases, epilepsy surgery, and hemangioblastoma, the tissue was dissected at pressures between 3 and 17 bars, which preserved blood vessels. Dissection of meningiomas and the ICA stenosis required higher pressures (between 20 and 45 bars); with these pressures, blood vessels were also dissected. CONCLUSIONS: These results indicate that the waterjet dissection procedure can be used intraoperatively without complications. This device appears to be particularly suitable for the dissection of highly vascularized gliomas or normal brain tissue, in which tissue dissection with sparing of blood vessels can be achieved. To prove that this is a useful addition to the neurosurgical armamentarium, reduction of blood loss or postoperative brain edema compared with conventional methods should be demonstrated in future studies.