Continuous intraventricular pressure monitoring for diagnosis of normal-pressure hydrocephalus.

OBJECTIVES: Normal-pressure hydrocephalus (NPH) syndrome is treatable by implantation of a cerebrospinal fluid (CSF) shunt. However, diagnosis of NPH by clinical and radiological findings alone is unreliable, and co-existing structural dementia can contribute to low success rates after shunt implantation. The aim of our study was to investigate whether long-term results after shunt implantation in NPH improve when surgical candidates are selected by continuous intraventricular pressure monitoring (CIPM). PATIENTS AND METHODS: Ninety-two consecutive patients who were admitted with suspected NPH received CIPM for 48 h including an intraventricular steady-state infusion test to determine the resistance outflow. With positive CIPM, shunt implantation was performed and the patients were prospectively followed up for 1 to 10 years (median 6.5 years). RESULTS: CIPM was negative in 37 patients. Fifty-five patients had a positive CIPM and received CSF shunt. 96.1% of them improved from gait disturbance, 77.1% from cognitive impairment and 75.7% from urinary dysfunction. Clinical improvement remained during long-term follow-up in all but 3 patients who showed a decline at 4, 5 and 7 years, respectively. CIPM-related complications (ventriculitis) occurred in only one patient. CONCLUSION: CIPM is a safe and valuable tool to establish a reliable diagnosis of NPH and to identify promising surgical candidates.

Minimally invasive retroperitoneal approach for lumbar corpectomy and anterior reconstruction. Technical note.

The anterior decompressive procedure in which spinal fusion is performed is considered an effective treatment for thoracolumbar fractures and tumors. However, it is also known to be associated with considerable surgery-related trauma. The purpose of this study was to show that lumbar corpectomy and anterior reconstruction can be performed via a minimally invasive retroperitoneal approach (MIRA) and therefore the surgical approach-related trauma can be reduced. The authors studied retrospectively the hospital records and radiological studies obtained in five patients (mean age 67.4 years, range 59-76 years) who underwent lumbar corpectomy and spinal fusion via an MIRA followed by posterior fixation. Four patients presented with osteoporotic compression fractures at L-2 and L-3, and one patient presented with metastatic disease in L-4 from prostate cancer. Neurological deficits due to cauda equina compression were demonstrated in all patients. The MIRA provided excellent exposure to facilitate complete decompression and anterior reconstruction in all patients, as verified on follow-up radiographic studies. All patients improved clinically. A 1-year follow-up record is available for four patients and a 6-month follow-up record for the fifth patient; continuing clinical improvement has been observed in all. Radiography demonstrated anatomically correct reconstruction in all patients, as well as a solid fusion or a stable compound union in the four patients for whom 1-year follow-up records were available. The MIRA allows the surgeon to perform anterior lumbar spine surgery via a less invasive approach. The efficacy and safety of this technique and its potential to reduce perioperative morbidity compared with conventional retroperitoneal lumbar spine surgery should be further investigated in a larger series.

Minimally invasive retroperitoneal approach for lumbar corpectomy and reconstruction. Technical note.

Anterior decompressive surgery with spinal fusion is considered an effective treatment for thoracolumbar fractures and tumors. However, it is also known to be associated with considerable surgical approach-related trauma. The purpose of this study was to show that lumbar corpectomy and spinal reconstruction can be performed via a minimally invasive retroperitoneal (MIR) approach and therefore, the surgical approach-related trauma can be reduced. The hospital records and radiological studies obtained in five patients (mean age 67.4 years, range 59-76 years) who underwent lumbar corpectomy and spinal fusion via an MIR approach were studied retrospectively. Four patients presented with osteoporotic compression fractures at L-2 and L-3 and one patient with metastatic disease at L-4 from prostate cancer. In all patients neurological deficits due to cauda equina compression were demonstrated. The MIR approach provided excellent exposure to facilitate complete spinal decompression and reconstruction in all patients, as verified on follow-up x-ray studies. All patients improved clinically. A 1-year follow-up record, available for four patients, showed evidence of continuing clinical improvement and, radiographically, a solid fusion or a stable compound union and anatomically correct reconstruction. The MIR approach allows anterior lumbar spine surgery to be performed less invasively. The efficacy and safety of this technique compared with the conventional retroperitoneal approach to lumbar spine surgery should be further investigated in a larger series.

Tumor growth of suspected meningiomas in clinically healthy 80-year-olds: a follow up five years later.

BACKGROUND: The incidence of clinically silent meningiomas in 75-year-old individuals was determined five years ago in the Vienna Transdanube Ageing Study (VITA). At the time a watch-and-wait approach was recommended in cases of incidentally discovered meningiomas. METHODS: 420 out of the initial cohort of 532 test persons underwent control investigations after 2.5 and 5 years. Six of the nine known tumors were measured again and the patients underwent clinical, neurological and psychological tests. Changes in tumor size were determined and all new tumors seen on MRI investigation were carefully reviewed. RESULTS: Tumor growth was minimal in all six cases that were followed over the entire period. Two of the original meningioma patients had died and one patient had undergone tumor resection. CONCLUSIONS: The watch-and-wait approach recommended after the VITA study was confirmed by the present investigation. Tumor growth was slow in all cases; no clinical symptoms have been registered thus far. The intervals between control investigations may even be prolonged depending on the location of the tumor. In this age group the operation appears to pose a greater risk than the presence of an asymptomatic tumor.

Noncontiguous spinal metastases and plasmocytomas should be operated on through a single posterior midline approach, and circumferential decompression should be performed with individualized reconstruction.

BACKGROUND: In noncontiguous spinal metastatic disease, anterior or combined anterior-posterior surgery is an effective treatment. The objective of this study is to investigate whether circumferential decompression through a single-stage posterior midline approach with individualized spinal reconstruction can still achieve comparable results for functional improvement and for maintenance of spinal alignment in the absence of the risks associated with the more invasive transcavitary or combined approaches. METHOD: Seventeen patients with noncontiguous spinal metastases and plasmocytomas at one or two adjacent levels were included in this series. Circumferential decompression was obtained with anterior reconstruction and posterior fixation in ten patients, and with posterior instrumentation alone in seven patients. Postoperatively the patients were prospectively followed, and their functional status and spinal alignment were periodically evaluated. FINDINGS: Fourteen patients died from progression of their underlying cancer. Their mean survival time was 8 months (range: 1 to 21 months). Three survivors were evaluated at 10, 4 and 3 months respectively. At one month after surgery, 14 patients (82%) showed neurological improvement. Of 10 preoperative nonambulators, seven regained walking capacity. Five patients who were ambulatory with assistance improved to full functional independence. Local tumour recurrence was recorded in one patient after subtotal vertebrectomy for a plasmocytoma at L5. No other tumour recurrences were noted. In one patient a partial loss of correction occurred at T6 - without functional deterioration, however. Spinal alignment was maintained in all other patients who became or remained ambulatory. No major intra-operative complications or peri-operative deaths occurred. CSF leakage was recorded as the most common complication in four patients. INTERPRETATION: Circumferential decompression and spinal reconstruction through a single-stage posterior midline approach is feasible and effective. The extent of surgery can be individualized by means of this technique to the patient's specific problem. In patients with limited life expectancy from metastatic neoplastic disease, the results compare favourably with the more invasive anterior or combined antero-posterior procedures.

Early diagnosis of external ventricular drainage infection: results of a prospective study.

OBJECTIVES: The aim of this study was to evaluate the influence of total drainage time on the risk of catheter infection, and the predictive value of standard laboratory examinations for the diagnosis of bacteriologically recorded cerebrospinal fluid (CSF) infection during external ventricular drainage. METHODS: During a three year period, all patients of the neurosurgical intensive care unit (ICU), who received an external ventricular drain, were prospectivly studied. Daily CSF samples were obtained and examined for cell count, glucose and protein content. Bacteriological cultures were taken three times a week, and serum sepsis parameters were determined. RESULTS: 130 patients received a total of 186 external ventricular drains. The ventricular catheters were in place from one to 25 days (mean 7.1 days). In 1343 days of drainage, the authors recorded 41 positive bacteriological cultures in 21 patients between the first and the 22nd drainage day (mean 6.4). No significant correlation was found between drainage time and positive CSF culture. The only parameter that significantly correlated with the occurrence of a positive CSF culture was the CSF cell count (unpaired t test, p<0.05). CONCLUSIONS: Drainage time is not a significant risk factor for catheter infection. Increasing CSF cell count should lead to the suspicion of bacteriological drainage contamination. Other standard laboratory parameters, such as peripheral leucocyte count, CSF glucose, CSF protein, or serum sepsis parameters, are not reliable predictors for incipient ventricular catheter infection.

Penetration failure and misdiagnosis of stereotactic biopsy caused by the uncommonly firm tissue of a gliomyosarcoma.

OBJECTIVE AND IMPORTANCE: We report the very rare case of a gliomyosarcoma that caused penetration failure in stereotactic biopsy and therefore led to misdiagnosis. This complication should be considered as a potential reason for diagnostic failure with uncommonly firm tumors in frame-based stereotactic biopsy. CLINICAL PRESENTATION: An 83-year-old women presented with a 4-week history of right hemiparesis. Computed tomography (CT) demonstrated a left precentral lesion of 1 cm in diameter with moderate contrast uptake and perifocal edema. INTERVENTION: Stereotactic biopsy was performed using the Cosman-Robert-Wells (CRW) system and a side-aspirating biopsy needle. Six tissue samples were taken; however, histopathologic examination remained non-diagnostic. Because the hemiparesis had worsened, a magnetic resonance tomography (MRT) was taken four weeks later and clearly demonstrated an increase in size of the lesion. Neuronavigation-guided open surgery revealed a very firm, well-delimited tumor that was classified in the pathologic examination as a gliomyosarcoma. Repeated recalculations of the target coordinates, analysis of the CT scan that was taken 4 days after the stereotaxy, and finally, recognition of the extraordinary firmness of this gliomyosarcoma allowed us to presume with certainty that we had not penetrated the lesion with the biopsy cannula, but rather had merely pushed it ahead of the instrument while the tissue samples were taken. CONCLUSION: The reported case is both unique for its histopathologic diagnosis and for the complication it caused in stereotactic biopsy. The case also supports the implementation of image-guided interventions for diagnostic biopsy, rather than frame-based stereotaxy in the future.

[Behavior of cerebral blood flow velocity in conventional ventilation and superimposed high frequency jet ventilation]. / Das Verhalten der zerebralen Blutflussgeschwindigkeit unter konventioneller Beatmung und unter superponierter Hochfrequenz-Jet-Ventilation.

OBJECTIVE: Patients with increased intracranial pressure or vasospasm after subarachnoidal haemorrhage with decreased cerebral perfusion present a special problem on developing respiratory insufficiency, since kinetic therapy or extracorporal life support are contraindicated. Superimposed High Frequency Jet Ventilation (SHFJV) has been shown to be of benefit in ventilating patients with pulmonary insufficiency. The aim of this study was to evaluate if SHFJV could be safely applied in patients with critical cerebral blood flow; if so, SHFJV might be beneficial when pulmonary insufficiency occurs concomitantly. METHODS: The study was performed in 14 patients (3 with pulmonary insufficiency) applying first moderate hyperventilation (paCO2 31 to 36 mmHg) followed by increased hyperventilation (paCO2 27 to 30 mmHg) with CMV and SHFJV and measuring intracranial pressure (ICP), cerebral perfusion pressure (CPP) and blood flow velocity (BFV) of the middle cerebral artery. BFV of the middle cerebral artery which correlates closely to the cerebral blood flow, was measured continuously with transcranial Doppler ultrasound. RESULTS: CMV: Increased hyperventilation leads to a statistically significant increase in paO2 (121.3 to 147.2 mmHg, p < 0.05), SaO2 (98.5% to 99.2%, p < 0.05) and decrease in BFV (systole 115.9 to 89.6 cm/s, diastole 44.6 to 31.8 cm/s, p < 0.05). Heart rate, mean arterial blood pressure, ICP and ventilation parameters did not show any statistically significant differences. SHFJV: During SHFJV the parameters demonstrated similar patterns as during CMV. However, none of the changes were statistically significant (paO2 111.9 to 125.9 mmHg, SaO2 97.9 to 98.8, BFV systole 106 to 95 cm/s, diastole 52.7 to 42.4 cm/s, n.s.). After calculating the mean BFV according to the Markwalder formula to a standard paCO2 of 40 mmHg CMV and SHFJV were compared to one another. No statistical difference was seen between the two different ventilation techniques. CONCLUSION: In patients with increased ICP, pulmonary complications such as pneumonia or ARDS are frequently observed. Since there are indications that SHFJV is of benefit in pulmonary insufficiency, the study was conducted to demonstrate that SHFJV can be safely applied in patients with increased ICP.

Fine needle cholangiography in the diagnosis of persistent jaundice. A case report.

The fine needle technic utilizes a sleeveless, thin, flexible needle for transhepatic cholangiography. This needle can enter small or normal bile ducts in a high percentage of patients. The value of fine needle cholangiography is illustrated in a patient with a stenosis of the common hepatic duct and a left hepatodochalduodenal fistula which eluded diagnosis by all other methods. The use of this technic is described as an alternative procedure to endoscopic retrograde cholangiography when the latter is technically impossible or as an adjunct to intraoperative extrahepatic cholangiography.

Chiba percutaneous transhepatic cholangiography. A valuable method for visualizing the nondilated biliary tract.

Percutaneous transhepatic cholangiography with the Chiba needle has had remarkable results in cannulating small bile ducts. We have roentgenographically visualized a nondilated biliary system in the first five out of seven cases attempted. Including our series, there have been 71 successful Chiba studies in 107 nondilated or presumed normal biliary tracts with only one questionable major complication. The technique is simple to learn, particularly in comparison with endoscopic retrograde cholangiography. Since the incidence of complications is low, surgical standby should seldom be necessary. The value of the Chiba percutaneous transhepatic cholangiogram is described via four unusual case reports.

Gamma knife radiosurgery of skull base meningiomas.

BACKGROUND: The standard surgical treatment of meningiomas is total resection of the tumour. The complete removal of skull base meningiomas can be difficult because of the proximity of cranial nerves. Stereotactic radiosurgery (SRS) is an effective therapy, either for adjuvant treatment in case of subtotal or partial tumour resection, or as solitary treatment in asymptomatic meningiomas. METHOD: Between September 1992 and October 1995. SRS using the Leksell Gamma Knife was performed on 46 patients (f:m 35:15), ranging in age from 35 to 81 years, with skull base meningiomas at the Neurosurgical Department of the University of Vienna. According to the indication of gamma knife radiosurgery (GKRS) the patients (n = 46) were divided into two subgroups. Group I (combined procedure: subtotal resection followed by GKRS as a planned procedure or because of a recurrent meningioma), group II (GKRS as the primary treatment). Histological examination of tumour tissue was available for 31 patients (67%) after surgery covering 25 benign (81%) and 6 malignant (19%) meningioma subtypes. FINDINGS: The overall tumour control rate after a mean follow-up period of 48 months (ranging from 36 to 76 months) was 96% (97.5% in benign and 83% in malignant meningiomas). Group I displayed a 96.7% tumour control rate, followed by group II with 93.3% respectively. Neurological follow-up showed an improvement in 33% stable clinical course in 58%) and a persistent deterioration of clinical symptoms in 9%. Remarkable neurological improvement after GKRS was observed in group II (47%), whereas in group I (26%) the amelioration of symptoms was less pronounced. INTERPRETATION: GKRS in meningiomas is a safe and effective treatment. A good tumour control and low morbidity rate was achieved in both groups (I, II) of our series, either as a primary or adjunctive therapeutic approach. The planned combination of microsurgery and GKRS extends the therapeutic spectrum in the treatment of meningiomas. Reduction of tumour volume, increasing the distance to the optical pathways and the knowledge of the actual growing tendency by histological evaluation of the tumour minimises the risk of morbidity and local regrowth. Small and sharply demarcated tumours are in general ideal candidates for single high dose-GKRS, even after failed surgery and radiation therapy, and in special cases also in larger tumour sizes with an adapted/reduced margin dose.