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Biomedical subjects

W Dietrich

Publications and source records attributed to W Dietrich.

At least 19 recordsLinked to original sources
PubMed2000

Drew-Anderson technique attenuates systemic inflammatory response syndrome and improves respiratory function after coronary artery bypass grafting.

BACKGROUND: Cardiopulmonary bypass causes inflammatory reactions leading to organ dysfunction postoperatively. This study was undertaken to determine whether using patients' own lungs as oxygenator in a bilateral circuit (Drew-Anderson Technique) could reduce systemic inflammatory response to cardiopulmonary bypass, improving patients clinical outcome following coronary artery bypass grafting. METHODS: A prospective randomized controlled trial involving 30 patients, divided in two groups of 15 patients each, undergoing elective coronary artery bypass grafting, was undertaken. In the Drew-group bilateral extracorporeal circulation using patient's lung as oxygenator was performed. The other patients served as control group, where standard cardiopulmonary bypass procedure was used. RESULTS: Pro-inflammatory and anti-inflammatory mediators were measured. Peak concentrations of proinflammatory interleukin-6, interleukin-8, were significantly lower in 15 patients undergoing Drew-Anderson Technique compared with the concentrations measured in 15 patients treated with standard cardiopulmonary bypass technique. Differences in patient recovery were analyzed with respect to time of intubation, blood loss, intrapulmonary shunting, oxygenation, and respiratory index. In patients undergoing uncomplicated coronary artery bypass grafting procedures bilateral extracorporeal circulation using the patients' own lung as oxygenator provided significant biochemical and clinical benefit in comparison to the standard cardiopulmonary bypass procedure. CONCLUSIONS: This prospective randomized clinical study has demonstrated that exclusion of an artificial oxygenator from cardiopulmonary bypass circuit significantly decreases the activation of inflammatory reaction, and that interventions that attenuate this response may result in more favorable clinical outcome.

Aged↗
PubMed1999

ORSAT and modifications of SEFT and APT.

Up to now, three subspectra are usually needed for the complete assignment of all signals in 13C spectrum: two DEPT spectra (phi = 90 degrees and phi = 135 degrees) and a proton decoupled spectrum. In this paper, we present a method in which a complete assignment becomes possible with merely two spectra. For this purpose, a new pulse sequence (ORSAT) has been elaborated by using off-resonance irradiation. The method described here is a further development of SEFT and APT. The second required spectrum is a DEPT (phi = 135 degrees). Signal assignment of cholesteryl acetate is demonstrated as an example. 13C routine spectroscopy can be significantly accelerated by applying this method.

Benzene Derivatives↗
PubMed1999

[Intraoperative blood requirements and allogeneic blood transfusion in cardioanesthesia. Data analysis of 7729 patients in 12 cardiac surgical clinics].

UNLABELLED: Allogeneic blood requirements in cardiac surgery shows a wide variation even for comparable procedures. The aim of the present study was to compare the intraoperative allogeneic blood requirement in defined cardiac operations among 12 cardiac centers in Germany. METHOD: A data set with 25 variables concerning the intraoperative course in adult cardiac patients with myocardial revascularization, valve replacement (aortic or/and mitral valve) or combined procedures was distributed to the participating centers. The data of all patients between January 1th 1998 and June 30th 1998 were included. Besides demographic data, the intraoperative transfusion of allogeneic and autologous blood, fresh frozen plasma and the concomitant hematocrit values were registered. Data were analyzed for all centers and separated for each center. RESULTS: The data of 7,729 patients were analyzed. The intraoperative allogeneic blood requirement was 0.6 +/- 1.3 units for all patients. It varied among the centers from 0.25 +/- 0.6 units to 0.97 +/- 1.6 units (P < 0.05). The percentage of patients receiving allogeneic blood was 27% and differed among the centers from 17% to 35%. Female patients were transfused in 53% (36-39%) compared to male patients with 16% (9-20%) (P < 0.05). The rate of autologous blood predonation varied from 0.5% to 23%. Patients without autologous predonation were transfused in 28% compared to 4% in patients with predonation (P < 0.05). In patients with autologous predonation the intraoperative transfusion of allogeneic blood was significantly reduced (0.1 +/- 0.39 vs 0.6 +/- 1.4 units, P < 0.05). However, some centers with a high percentage of autologous predonation also demonstrated a high rate of perioperative allogeneic transfusion. CONCLUSION: The incidence of allogeneic blood transfusion in cardiac surgery depends on the institution and not on the surgical procedure. A common threshold value of hemoglobin for the transfusion of blood trigger even for comparable procedures could not be detected among the centers. Especially in female patients, there was a wide variation in allogeneic blood transfusion. Autologous blood predonation reduces blood requirement significantly, however, it is practiced with variing intensity. The data set did not include information about transfusion regimen in the postoperative period, thus, these data do not allow to draw conclusions for the whole perioperative period.

Adult↗
PubMed1999

Expression of BCL-2 oncoprotein on tumor cells and tumor-infiltrating lymphocytes (TIL) in meningiomas.

The Expression of the antiapoptotic oncoprotein BCL-2 and its correlation to tumor grade in 62 meningiomas (48 classic, 9 atypical, and 5 anaplastic) using single and double immunohistochemistry was investigated. BCL-2 expression was found in two different cell populations identified as lymphocytes (BCL-2+CD3+) and tumor cells (BCL+/CD3-). Tumor-infiltrating lymphocytes (TIL) (CD3+) were found within classic (9.5% of cells), atypical (2.4% of cells), and anaplastic (1.8% of cells) meningiomas. In classic meningiomas, 66.5% of TIL were BCL-2-positive, in atypical meningiomas 79.2%, and in anaplastic meningiomas 37.9%. In 33 (68.8%) of the classic meningiomas, medium to high counts of BCL-2+ tumor cells were detected. Atypical meningiomas showed nearly equal percentages of high (two patients), medium (five patients), and low (two patients) BCL-2+ tumor cell counts, whereas anaplastic meningiomas showed only medium (two patients) and low (three patients) BCL-2 tumor cell counts or were BCL-2-negative (one patient). In summary, a significant inverse correlation between the number of BCL-2-positive tumor cells and tumor grade in meningiomas was found. These findings support the hypothesis of cell survival prolongation by the antiapoptotic ability of BCL-2 proto-oncogenes and demonstrate the prognostic relevance of BCL-2 immunoreactivity in meningiomas.

CD3 Complex↗
PubMed1999

Multiple spinal "miliary" hemangioblastomas in von Hippel-Lindau (vHL) disease without cerebellar involvement. A case report and review of the literature.

We report on a 57-year-old male presenting with radicular pain in the nerve roots of L5 and S1 on the right side and dysuria. Magnetic resonance imaging (MRI) of the lumbar spine showed multiple (up to 20) small, intradural enhancing nodules attached to the cauda equina down to the sacrum, the largest 1 cm in diameter at the level Th12/L1 compressing the conus. Additionally, small nodules in the cervico-thoracal region adjacent to the cord, but no cerebellar or cerebral abnormalities, were detected in a consecutive MRI of the remaining neuroaxis. The histology of a resected lesion at Th12/L1 revealed hemangioblastoma of the reticular type. Together with a history of left eye enucleation performed 17 years ago for angiomatosis of the retina and the immunohistochemical detection of von Hippel-Lindau (vHL) protein within the removed spinal hemangioblastoma, a diagnosis of vHL disease was established. Family history and screening for visceral manifestations of vHL disease were negative. In contrast to cerebellar or solitary spinal hemangioblastomas, multiple spinal hemangioblastomas without cerebellar involvement in vHL represent unusual manifestations. Unlike the case for solitary lesions in non-syndromic patients, a surgical cure does not seem feasible in this case. The role of treatment modalities is discussed.

Biomarkers, Tumor↗
PubMed1999

Latex sensitization in spina bifida appears disease-associated.

OBJECTIVE: The high prevalence of latex sensitization (up to 80%) in patients with spina bifida (SB) has been attributed to repeated exposure to latex products, whereas disease-associated factors have not been considered. METHODS: We compared children with SB (n = 21) and children with posthemorrhagic or congenital hydrocephalus (PH, n = 32), all of whom had a ventriculoperitoneal shunt since young age. Latex sensitization, number of operations, atopic history, and total IgE levels were evaluated. RESULTS: The following characteristics were recorded: age (SB: 52 months, range 1 to 264 months; PH: 71 months, range 1 to 192 months) and mean number of operations (SB: 2. 09; PH: 2.53). Of the SB group, 43% (9 of 21) showed elevated latex-specific IgE antibodies in contrast to 6% (2 of 32) in the PH group (P <.01). Latex-specific IgE antibodies were detected by 1 year of age, and one surgical operation was sufficient to induce latex-specific IgE-antibody production in patients with SB. CONCLUSIONS: The results suggest that the SB population bears a disease-associated propensity for latex sensitization. Sensitization to latex antigens may occur after the very first contact, arguing for latex avoidance measures from the very beginning of life.

Adolescent↗
PubMed1999

Proliferative activity as measured by MIB-1 labeling index and long-term outcome of visual pathway astrocytomas in children.

Although most visual pathway tumors are low-grade gliomas their biologic behavior is highly unpredictable. In order to determine whether assessment of proliferative activity can assist in predicting tumor behavior, we studied the MIB-1 labeling indices (MIB-1 LIs) in surgical specimens and monitored tumor growth in 31 consecutive children operated on between 1978 and 1997. The MIB-1 LIs at diagnosis varied from 0-10.6% (mean +/- SD, 3.27 +/- 2.49%). Tumor progression occurred in 19 patients leading to death in seven, three of whom had neurofibromatosis type 1 (NF1). No association between MIB-1 LI at initial diagnosis and both progression free and overall survival was apparent. However, the MIB-1 LIs increased to 15.2% and 18% in two patients with NF1 who developed highly malignant gliomas 6 and 6.5 years after irradiation. In the remaining patients the MIB-1 LIs did not change significantly over time in a total of 17 repeat surgeries. Three patients with LIs of 6.8%, 10.6% and 8.8% are stable after 6, 4.5 and 3.5 years with partial resection, biopsy and subtotal resection, respectively, and no further therapy in the first two and chemotherapy in the latter. Three patients (10%) with LIs of 6.4%, 4.8% and 2.2% either presented with or developed leptomeningeal spread during follow-up. While MIB-1 LI does not appear to assist in clinical decision making patient numbers were too small to find out whether response to chemotherapy varies with proliferative potential.

Adolescent↗
PubMed1999

Histopathological findings in experimental aneurysms embolized with conventional and thrombogenic/antithrombolytic Guglielmi coils.

We studied the short- and long-term histological responses induced by conventional and modified electronically detachable coils (GDCs) in experimental aneurysms. Eighteen carotid bifurcation aneurysms were produced microsurgically in rabbits. Six animals each were treated either with conventional or with GDCs coated with a mixture of tissue-thromboplastin to enhance intra-aneurysmal thrombus formation and of plasminogen activator inhibitor type-1 (PAI-1) in inhibit intra-aneurysmal clot fibrinolysis. Six served as untreated controls. Follow-up angiograms were obtained immediately and at 3, 6, 9, 12, 17, and 24 weeks after embolization prior to sacrifice of the animals. All aneurysms were studied macroscopically and histopathologically with the coils in situ. Five of six control aneurysms remained patent. Endovascular occlusion rates between > 90% and 100% were achieved in nine of twelve coiled aneurysms. Follow-up angiography demonstrated recanalization and coil compaction in 5 of them. Gross and microscopic histopathological examination revealed a membrane covering the orifice, intra-aneurysmal scar formation, and development of a neo-intima in both treatment groups at 17 and 24 weeks postembolization. The granulation tissue response appeared to be equally distributed in aneurysms treated with either uncoated or coated coils. Further quantitative morphometric studies are needed to prove if a thrombogenic/antithrombolytic coil-coating might be of value in providing a more enduring anatomic result after GDC-treatment of human brain aneurysms.

Aneurysm↗
PubMed1999

Extracerebral organ dysfunction and neurologic outcome after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: To analyze the influence of extracerebral organ system dysfunction after aneurysmal subarachnoid hemorrhage (SAH) on mortality and neurologic outcome. DESIGN: Observational study with retrospective data extraction. SETTING: Neurosurgical intensive care unit (NICU) at a primary level university hospital, supervised and staffed by both members of the Clinic of Neurosurgery and the Clinic of Anesthesiology and General Intensive Care. PATIENTS: Two hundred forty-two patients treated for intracranial aneurysm rupture within 7 days of the most recent SAH. INTERVENTIONS: Routine neurosurgical interventions for obliteration of the ruptured aneurysm (microsurgery, Guglielmi Detachable Coils embolization) and for treatment of posthemorrhagic hydrocephalus (ventriculostomy, cerebrospinal fluid shunt implantation). MEASUREMENTS AND MAIN RESULTS: Respiratory, renal, hepatic, cardiovascular, and hematologic organ system functions were evaluated both individually and in aggregate by using a modified version of the Multiple Organ Dysfunction (mMOD) score. Of 1,452 organ system functions assessed in 242 patients during their NICU stay, 714 organ system functions were intact (cerebral: 0, extracerebral: 714), 556 organ systems had mild-to-moderate dysfunctions (mMOD scoremax 1-2 for the affected organ system; cerebral: 153, extracerebral: 403), and 182 organ systems failed (mMOD scoremax 3 for the affected organ system; cerebral: 89, extracerebral: 93). Severity of extracerebral organ system dysfunctions correlated with the degree of neurologic impairment (Hunt and Hess [H&H] score) in a graded fashion. Similarly, the chance to develop systemic inflammatory response syndrome (SIRS) during the NICU stay increased with increasing admission H&H grade. The incidence of SIRS and septic shock was 29% and 10.3%, respectively. The mortality rate was 40.2% in patients with SIRS and 80% for patients suffering septic shock. Seventy-seven percent of extracerebral organ system failures (OSFs) occurred in conjunction with SIRS: 51% of respiratory OSFs, 97% of renal OSFs, 100% of hepatic OSFs, 96% of cardiovascular OSFs, and 73% of hematopoietic OSFs. Both CNS dysfunction and extracerebral organ system dysfunctions were significantly related to neurologic outcome. The probability of unfavorable neurologic outcome significantly increased with both decreasing cerebral perfusion pressure (CPP) and increasing severity of extracerebral organ dysfunction. CONCLUSION: Aneurysmal SAH and its neurologic sequelae accounted for the principal morbidity and mortality in the current series. Development of extracerebral organ system dysfunction was associated with a higher probability of unfavorable neurologic outcome. Systemic inflammation (SIRS) and secondary organ dysfunction were the principal non-neurologic causes of death.

Adult↗
PubMed1999

Growing blood clot mimicking an aneurysm on postoperative computerized tomography and magnetic resonance imaging studies. Case report and review of the literature.

The authors describe the case of a 15-year-old boy who underwent resection of a large left temporal tumor. During a normal postoperative course, computerized tomography (CT) scanning demonstrated a spherically hyperdense structure near the internal carotid artery, enlarging on a control CT scan. A suspected false aneurysm was confirmed on magnetic resonance imaging; angiographic studies were negative. The authors believed they were dealing with a thrombosed false aneurysm and they performed operative revision. Intraoperatively the "aneurysm" could be dissected off the internal carotid artery and no lesion of the arterial wall was obvious. Histological findings showed a fresh blood clot. This case demonstrates that a blood clot may mimic an aneurysm on CT and magnetic resonance studies, which has not been described earlier. The origin of the blood clot remains unclear.

Adolescent↗
PubMed1999

[Effect of stomach motility on measuring stomach permeability with saccharose in vivo].

Determination of the urinary excretion of sucrose after an oral dose has been used as a noninvasive test to measure gastric permeability in several clinical studies. Regarding different contact times of sucrose solution within the gastric mucosa, the present study investigates a possible influence of the gastric emptying rate on the sucrose permeability test. Urinary sucrose excretion and the gastric emptying rate of liquids using 13C-acetate breath test were determined in twelve healthy volunteers. Furthermore, in seven volunteers gastric emptying was accelerated by intravenous erythromycin and prolongated by oral anticholinergic propantheline in nine healthy controls. Breath samples were measured using infrared spectroscopy. The half-emptying time and Lag-phase were correlated with the urinary sucrose excretion. Erythromycin caused a significant (p = 0.02) reduction of the half-emptying time (median 35.0 min) compared with untreated controls (median 59.9 min), whereas propantheline significantly increased the half-emptying time (median 69.4 min, p = 0.01). After pharmacological increase of the half-emptying time the urinary sucrose excretion only slightly differs from the sucrose excretion of controls (median [range] 0.057 [0.034-0.106]% versus 0.031 [0.017-0.162]%), but there was an increase of urinary sucrose excretion in probands following reduction of the half-emptying time with erythromycin (0.077 [0.023-0.221]%. The present study shows that gastric motility has a possible influence on the sucrose permeability test. The sucrose permeability has to be interpreted critically concerning its clinical use especially in patients with altered gastric motility.

Adult↗
PubMed1998

Influence of high- and low-dose aprotinin on activation of hemostasis in open heart operations.

BACKGROUND: The protease inhibitor aprotinin reduces hemostatic activation and blood loss after cardiac operations. The aim of the present study was to investigate the influence of two different aprotinin doses on hemostatic activation and to identify the most effective dose to reduce the postoperative bleeding tendency. METHODS: In a prospective, randomized, double-blind clinical trial, 230 patients scheduled for routine open heart operations received either high-dose (group H) or low-dose (group L) aprotinin. Primary outcome measures were the level of F(1+2) prothrombin fragments as a marker of thrombin generation, the level of D-dimers as an indicator of fibrinolysis, and the amount of postoperative blood loss. Allogeneic blood transfusion was recorded as a secondary outcome measure. RESULTS: Aprotinin plasma concentrations 5 minutes after the onset of cardiopulmonary bypass were 166 +/- 45 kallikrein inactivator units per milliliter in group H and 118 +/- 30 kallikrein inactivator units per milliliter in group L (p < 0.05). Fibrinolytic activation was reduced significantly in group H compared with group L: the level of D-dimers at the end of CPB was 1,027 +/- 781 ng/mL and 1,977 +/- 1,001 ng/mL, respectively, in the two groups (p < 0.05). However, thrombin generation (F(1+2) fragments) did not differ between the two groups (7.4 +/- 3.5 nmol/L in group H and 8.6 +/- 4.3 nmol/L in group L). Twenty-four-hour postoperative blood loss was 663 +/- 461 mL in group H compared with 877 +/- 513 mL in group L (p < 0.05), and the corresponding allogeneic blood requirement was 1.3 +/- 1.9 U in group H and 1.9 +/- 2.3 U in group L (p < 0.05). CONCLUSIONS: A high-dose aprotinin regimen was significantly more effective than a low-dose regimen in attenuating fibrinolysis and reducing the bleeding tendency and allogeneic blood requirements, but not in reducing F(1+2) prothrombin fragments. High-dose aprotinin therapy appears to be superior to low-dose therapy.

Aprotinin↗
PubMed1998

Activation of hemostasis during cardiopulmonary bypass and pediatric aprotinin dosage.

BACKGROUND: Cardiopulmonary bypass results in inappropriate activation of the coagulation and fibrinolytic systems. Factors such as a greater degree of hemodilution, use of deep hypothermic circulatory arrest, the impact of cyanosis on coagulation, and the immature coagulation system of the newborn will increase the risk of problematic perioperative bleeding. METHODS: This article describes the characteristics of the hemostatic system in children undergoing cardiac operations and addresses the effect of aprotinin on hemostasis. Hemostatic parameters were measured in 96 pediatric patients using three different doses of aprotinin. The high-dose group (group 1) received 30,000 KIU/kg (4.2 mg/kg) of aprotinin after induction of anesthesia and an additional bolus of 30,000 KIU/kg (4.2 mg/kg) into the pump prime. In the low-dose group (group 2), both the initial bolus and the pump-prime dose of aprotinin were halved to 15,000 KIU/kg (2.1 mg/kg). Group 3 received the high dose with an additional bolus of aprotinin to the pump prime. RESULTS: Plasma levels of aprotinin in both groups 1 and 2 were lower than the 200 KIU/mL (0.03 mg/mL) value usually reached in adults with high-dose aprotinin treatment. Group 3 patients had levels greater than 200 KIU/mL (0.03 mg/mL) throughout the procedure. Biochemical indices of fibrinolysis (fibrin[ogen] degradation products, D-dimers) revealed significant and dose-dependent inhibition at all three aprotinin concentrations. In contrast, significant changes in coagulation activation markers (prothrombin fragments F1.2, thrombin-antithrombin III complex, and fibrin monomers) were found only in group 3. CONCLUSIONS: The inverse relationship between a small patient's blood volume and the large pump-prime volume requires additional aprotinin to be added to the prime to achieve plasma levels sufficient to inhibit activation of the coagulation cascade.

Age Factors↗
PubMed1998

Incidence of hypersensitivity reactions.

BACKGROUND: Aprotinin is a naturally occurring serine protease inhibitor derived from bovine lung. In common with all foreign proteins, it possesses antigenic properties and has the possibility of allergic reactions on reexposure. METHODS: Data are presented on the incidence of adverse reactions to aprotinin and the time course of antibody development after initial exposure. Recommendations for reducing the risk and sequelae of these adverse reactions are emphasized and case reports are reviewed. RESULTS: The incidence rates of aprotinin-related reactions to date (May 1997) at the German Heart Center are 2.7% in the adult population in reexposures (5/183) and 1.2% in the pediatric population (3/254), with an overall incidence of 1.8% (8/437). CONCLUSIONS: With the recommended precautions, reexposure to aprotinin in patients with a high risk of bleeding is justified, and the benefits of aprotinin treatment outweigh the relative risk of a serious allergic reaction.

Adolescent↗
PubMed1998

Frameless stereotactic lesion contour-guided surgery using a computer-navigated microscope.

BACKGROUND: The Zeiss MKM System is a recently developed computerized operating microscope for image-guided neurosurgery. The clinical advantages, reliability, accuracy, and limitations of this technique were investigated. METHODS: Since February 1995, 78 consecutive frameless stereotactic image-guided procedures were performed in 73 patients (30 males, 43 females; mean age, 46.9 years; range, 16-77 years) for tumor surgery (50/64.1%), cavernoma removal (16/20.5%), and functional procedures (12/15.4%). Skin markers (74 cases) or bone markers (4 cases) and a standard imaging protocol (2-mm cranial computed tomography (CCT) in 59 cases/1.5-mm magnetic resonance imaging (MRI) in 19 cases) were used. RESULTS: The main advantages were pre-operative skin incision, craniotomy and corticotomy planning, and determination of lesion boundaries. Useful registration and system reliability were noted in 97% (76/78) of the procedures. A significant improvement in registration accuracy was observed over the test period from a mean of 4.8 mm (SD = 3.36; Cases 1-25) to a mean of 2.2 mm (SD = 0.86; Cases 26-78). This resulted in an improvement in application accuracy from <5 mm in 71% (Cases 1-25) to <2 mm in 95% (Cases 26-78) of cases, and the accuracy led to successful localization of the lesion in every case. Accuracy was reliable at the beginning of every procedure, but degraded to values >5 mm by the end of the procedure in 29% (22/78) of cases. MRI cases achieved higher application accuracy values (2.1 mm mean) than CT cases (3.7 mm mean). CONCLUSIONS: The system offers a reliable alternative to frame-assisted stereotactic craniotomies in lesion targeting, but would need an intraoperative image update for resection guidance.

Adolescent↗
PubMed1998

Image-guided neurosurgery comparing a pointer device system with a navigating microscope: a retrospective analysis of 208 cases.

A retrospective analysis of neuronavigation procedures performed at the Vienna Neurosurgical Clinic was undertaken to elucidate the advantages of 2 technically different navigation systems in clinical use. In a 30-month period, 208 frameless stereotactic procedures were performed using a stereotactic microscope (MKM System, Zeiss; 92 procedures in 87 patients; 47 female, 40 male; mean age, 46 yrs) and a light emitting diode (LED) based pointer navigation device (Easy Guide Neuro (EGN), Philips; 116 procedures in 114 patients; 63 female, 51 male; mean age 46.4 yrs). The navigating microscope was exclusively used for cranial navigation, the pointer device system in 107 cases for cranial and in 9 cases for spinal navigation. Procedures were CCT-guided in 109 cases, MRI-guided in 95, and both CT/MRI guided in 4 cases. Skin fiducials were used in all these procedures. The MKM system provided coordinate-based navigation, similar to frame systems. This allowed surgical planning and performance using stereotactic coordinates for target calculation. Additionally, tumor volumes were defined by contours and projected into the ocular of the microscope, allowing guidance during targeting and resection of lesions. Both of these features proved beneficial in tumor surgery (60.8% MKM cases), cavernoma surgery (21.8% MKM cases), and epilepsy surgery (14.1% MKM cases). In contrast to the microscope, the pointer navigation system could be employed for intuitive correlation of image points with points of interest in the operating field by using a LED-equipped pointer device. This permitted image guidance during a wide spectrum of neurosurgical procedures, in tumor surgery (68.1% EGN cases), cavernoma surgery (5.1% EGN cases), epilepsy surgery (14.1% EGN cases), vascular surgery (3.4% EGN cases), spinal surgery (7.8% EGN cases), and guidance for burr holes and drainages (6.9% EGN cases), without calculating stereotactic coordinates. This analysis showed clear differences in the application of the two systems and may facilitate the decision as to which system best meets the individual demands of a neurosurgical department.

Adult↗
PubMed1998

Frameless stereotactic-directed tissue sampling during surgery of suspected low-grade gliomas to avoid histological undergrading.

Detection of anaplastic tumor foci for precise grading of gliomas is crucial for prognostic assessment and appropriate postoperative treatment planning. To avoided undergrading in large suspected low-grade gliomas, we employed frameless sterotaxy during open surgery for tissue sampling of radiologically suspected anaplastic foci. In nine patients (mean age 44 years, range 10-67) with large supratentorial suspected low-grade gliomas (32.4 ccm mean vol, range 17.9-68.6 ccm) with small contrast enhancing areas (7.7% mean of total volume, range 0.7-15.3%), a neuronavigation system with a pointer device (Easy Guide System Philips) or a navigating microscope (MKM System Zeiss) was used to target small enhancing tumor parts for cytological investigation during open surgery. Consecutive cytological smears revealed anaplastic tumor foci in all patients, correlating with neuroradiologically demonstrated small contrast enhancing areas, although biopsies from all other tumor parts showed low-grade tumors. Final neuropathological diagnosis confirmed anaplasia within the neuroradiologically suspected low-grade gliomas in all patients (2 grade IV, 5 WHO grade III and 2 grade II-III tumors, WHO classification). In our experience frameless stereotactic-directed intraoperative tissue sampling during open surgery of large suspected low-grade gliomas helps to identify small anaplastic areas in mostly large low-grade tumors, and therefore, permits optimum planning of postoperative treatment.

Adolescent↗