Separation Surgery, Fixation With Carbon-Fiber Implants, and Stereotactic Body Radiotherapy for Oligometastatic Spinal Disease.

The management of spinal metastases focuses on reducing symptoms and protecting the spinal cord, historically involving extracorporeal radiotherapy alone. The use of separation surgery techniques alongside high-dose radiotherapy to treat spinal metastases is a novel concept and has changed the treatment paradigm. Additionally, titanium implants have been increasingly used in cases of metastatic spinal tumours requiring adjuvant stereotactic radiotherapy (SBRT). We present the case of a 48-year-old female patient who was diagnosed with a metastatic deposit of breast cancer within L1 with an Epidural Spinal Cord Compression score greater than 1a. At the time of the diagnosis, her prognosis was estimated to be more than two years. She underwent a posterior instrumented fusion of T11-L3 vertebrae with a carbon-fibre fixation system and separation surgery (debulking of the tumour around the spinal cord). The patient was discharged on the second postoperative day achieving complete resolution of the mechanical back pain. SBRT was performed 12 weeks after the surgery. The patient regained ECOG status of 1 shortly after but sadly passed away due to multiple brain metastases 36 months following posterior fixation. Her spinal disease remained well-controlled throughout the follow-up. Carbon-fibre implants appear to be safe and relatively easy to apply. Their use, due to limited artefacts in both computed tomography and magnetic resonance imaging, makes SBRT much more straightforward and follow-up imaging easier to be interpreted. Our experience demonstrates that, in conjunction with separation surgery, the translucent, low perturbing properties of these implants can improve SBRT intervention and detection of recurrence on follow-up imaging.

Spinal Tumour en Bloc Surgery: A Series of Abandoned Surgical Cases.

Select spinal tumors can be treated with en bloc spondylectomy (EBS) but the surgical complexity and relatively low frequency of eligible tumors render EBS an uncommon procedure. The expanded surgical access encompasses acceptance of relatively high morbidity as a trade-off against improved oncological results and survival. EBS durations can be long with dynamic changes affecting the risk-benefit ratio as the surgery proceeds.  We present a series of cases where we have elected to "abandon" EBS due to adverse findings or rising intraoperative risk along with our lessons learned.  A search of our surgical database for all "en bloc" spinal tumor procedures over a three-year period was performed and 27 operations were identified. Of these, four were abandoned. Two of the four surgeries were halted owing to adverse anatomical findings. One involved significant tumor growth from the interval imaging bringing into question disease control and the other displayed tumor adherence to the lung requiring significant dissection. The further two cases incurred significant blood loss and associated physiological complications of end-organ dysfunction.  Pre-operative embolization (POE), anesthetic monitoring, controlled hypotension, volume replacement, and transfusion optimize our chance of achieving the surgical plan. However, cardiovascular instability must be managed promptly and early warning signs of end-organ injury (lactate, renal output) should not be overlooked. In some situations abandoning the procedure may be in the best interests of the patient.

Factors Influencing Surgical Outcomes for Intradural Spinal Tumours: A Single-Centre Retrospective Cohort Study.

Introduction Intradural spinal tumours are relatively uncommon tumours of the central nervous system. In this study, we sought to assess our current practice and determine the factors which affect the surgical outcomes of intradural spinal tumour resection. Methods All consecutive patients who underwent surgical resection of intradural spinal tumours from December 2011 to November 2018 were retrospectively reviewed. The Modified McCormick Scale (MMS) was used to grade patients' neurological status both pre-operatively and at the latest follow-up. The associations between changes in MMS and variables such as patient demographics, tumour location, number and experience of consultants involved in the procedure, use of intraoperative neuro-monitoring, bony spinal exposure and dural closure methods were assessed. A multivariable binary logistic regression model was performed to identify independent predictors of improvements in MMS. All analyses were performed using IBM SPSS 22 (IBM Corp. Armonk, NY), with p<0.05 deemed to be indicative of statistical significance throughout. Results A total of 145 patients met the inclusion criteria, with a median age of 56.5 years; of whom 119 had extramedullary tumours and 26 had intramedullary tumours. Methods of dural closure were variable, and there was an increasing trend over time towards using the laminoplasty approach for bony exposure. Neither the experience of consultants (p=0.991) nor the number of consultants involved (p=0.084) was found to be significantly associated with the change in MMS, with the strongest predictor being the baseline MMS (p<0.001). Patients who had adjuvant therapy were also significantly more likely to have a poorer neurological outcome (p=0.001). Conclusion A good neurological baseline is a significant positive predictor of an improved functional outcome. The number and seniority of consultant surgeons involved in intradural spinal tumour resections did not significantly alter the postoperative outcomes of patients in our single-unit retrospective study.

En Bloc Resection of Tumors of the Lumbar Spine: A Systematic Review of Outcomes and Complications.

BACKGROUND: The literature on total en bloc spondylectomy (TES) of bone tumors of the lumbar spine is sparse and heterogeneous. Therefore, the aim was to systematically pool the data from the published studies to quantitatively summarize the morbidity and mortality and to identify factors associated with favorable outcomes and complications. METHOD: A systematic literature search for studies with individual patient-level data was conducted using specific medical subject heading(MeSH) terms. The outcome measures assessed included complications, tumor recurrence, survival, and function. Individual patient data were pooled from all the studies and quantitatively analyzed to assess the association of different factors with outcomes and complications. RESULTS: Twelve studies were included in this review with a total of 145 TES cases. Of all patients, 50% had at least 1 reported complication post surgery and this was associated with advancing age (OR 1.04, P < 0.001), metastatic disease (OR 5.61, P < 0.001), and adjuvant chemo and/or radiotherapy (OR 20.3, P = 0.001). Intralesional excision (OR 5.2, P = 0.01) and primary malignant tumors (OR 3.3, P = 0.02) were associated with a high recurrence rate. However, the surgical approach was not associated with differences in survival (P = 0.874) or recurrence (P = 0.525) rates. L5 tumor resection was associated with excessive bleeding. Postoperatively, there was an overall improvement in the Frankel grades in most patients. CONCLUSION: TES is associated with high rates of complications especially in association with primary malignant and metastatic diseases. However, the number of publications on this topic remain scarce and heterogeneous. Hence, there is a need for standardization in the reporting of the outcomes and complications to help with decision-making and consenting for this procedure.

Should Denosumab or Radical Surgery Be Recommended for a Spinal Giant Cell Tumour in a Fertile Female?

Giant cell tumour (GCT) of the spine is a benign aggressive tumour with high recurrence rates. Patients can be asymptomatic due to the slow growth rate and present with localized pain or neurological dysfunction. Current management strategies include intralesional curettage, total en-bloc resection (TER) and denosumab therapy. Treatment strategies can be particularly challenging in women of childbearing age who wish to conceive, as the risks of tumour recurrence need to be balanced against the fetal complications associated with adjuvant denosumab therapy. This case report discusses the management options and controversies for women of childbearing age with GCT of the thoracic spine. Clinicians need to be aware of the complications associated with TER and denosumab treatment when managing GCTs of the spine in young females.

Metastatic Pituitary Carcinoma Causing Cord Compression.

A 39-year-old man with a history of recurrent pituitary tumor, Cushing disease, and Nelson syndrome presented with neck stiffness. He previously had bilateral adrenalectomy and hypophysectomy 27 years ago. He subsequently had repeat pituitary surgery, stereotactic radiosurgery, and chemotherapy for recurrent pituitary tumor. During follow-up, he was noted to have rising basal adrenocorticotrophin (ACTH) level. On examination, he was neurologically intact with no signs of myelopathy. Magnetic resonance imaging of the spine showed a large intradural extramedullary lesion causing cord compression at the C2-3 level. He underwent a cervical laminectomy and debulking of the lesion under continuous monitoring of motor-evoked and somatosensory-evoked potentials. He remained neurologically intact postoperatively. Histologic analysis revealed a tumor of pituitary origin with synaptophysin and ACTH expression. Pituitary drop metastasis is a rare entity and should raise a high index of suspicion given this clinical presentation. The radiologic appearance can mimic benign lesions such as meningioma or schwannoma.

Tumours of the odontoid peg revisited.

INTRODUCTION: Tumours of the odontoid peg are rare but can potentially cause significant morbidity and mortality. METHODS: A retrospective review of oncology and radiology database of tertiary orthopaedic oncology centre for all lesions affecting the odontoid peg over the last 12 years was performed. RESULTS: We identified a total of 15 tumours involving the odontoid peg, majority being malignant. Myeloma was the most common tumour. CONCLUSION: Tumours of the odontoid peg are rare. Spinal surgeons and Radiologists need to be aware of them.

Navigated neuroendoscopy combined with intraoperative magnetic resonance cysternography for treatment of arachnoid cysts.

Endoscopic cystocysternostomy or cystoventriculostomy is the treatment of choice in patients with symptomatic intracranial arachnoid cysts. There are no objective diagnostic tests for reliable intraoperative evaluation of the effectiveness of performed stomies. The aim of this prospective open-label study is to demonstrate for the first time the usefulness of intraoperative cysternography performed with the low-field 0.15-T magnetic resonance imager Polestar N20 during endoscopic cysternostomies. The study was performed in patients operated for middle fossa arachnoid cysts (n = 10), suprasellar cysts (n = 4), paraventricular or intraventricular cysts (n = 6), and a pineal cyst (n = 1). The operations were performed with use of a navigated neuroendoscope. Intraoperative magnetic resonance (iMR) cysternography was performed before and after the cystostomy. In each case, iMR cysternography was safe and could show clearly the cyst morphology and the effectiveness of performed endoscopic cystostomies. In six cases, iMR cysternography had a significant influence of the surgical decision (p = 0.027). The rate of inconsistency between the intraoperative observations and iMR imaging-based findings was 29%. A good contrast flow through the fenestrated cyst walls correlated with a good long-term clinical outcome (ρ = 0.54, p < 0.05) and good long-term radiological outcome (ρ = 0.72, p < 0.05). Intraoperative low-field MR cysternography is a safe and reliable method for assessment of the efficacy of performed endoscopic cystostomies and has significant influence on the surgical decision. It may be reliably used for prediction of the long-term clinical and radiological outcome.

Oblique corpectomy in the cervical spine.

STUDY DESIGN: A narrative review. OBJECTIVES: A literature review of studies reporting on the application of oblique corpectomy (OC) in various pathologies of the cervical spine. SETTING: UK. METHODS: A search was carried out using the PubMed and Google Scholar up to 18 March 2017. Finally, 26 studies met the inclusion criteria. RESULTS: A multilevel OC shows good clinical outcomes in various pathologies in the cervical spine. The clinical improvement in cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament was found to be over 70%. OC allows wide anterior decompression of the spinal cord and complete unilateral nerve root decompression. The approach carries a risk of Horner's syndrome, vertebral artery and accessory nerve injury. OC does not compromise spine stability and osteoarthrodesis with bone grafting is not necessary. Spinal motions are preserved and appear close to normal. OC can be applied in patients with a low fusion rate such as the elderly, diabetics, and heavy smokers. Furthermore, OC was found to be an optimal approach for exta-intradural tumors of the cervical spine. CONCLUSIONS: OC seems to be a valid alternative for the management of multisegmental CSM in selected cases. It should not be considered a first-line treatment strategy due to the relatively high morbidity. There are no studies comparing OC without fusion to other treatment options in CSM. Therefore, rigorous prospective studies using validated outcome measures with long-term follow-up are required.

HBcAg produced in transgenic tobacco triggers Th1 and Th2 response when intramuscularly delivered.

Hepatitis B core Antigen (HBcAg) assembled into Capsid-Like Particles (CLPs) is investigated as a therapeutic vaccine in treatment of chronic hepatitis B (CHB) and in diagnostic tests or as a carrier for various epitopes. While the expression of HBcAg has been thoroughly clarified in E. coli and yeast, it has also been investigated in other expression systems. Stably transformed tobacco expressed HBcAg at a level of 110-250µg/g fresh weight, therefore in view of its large leaf biomass it offers a production platform comparable with transient expression systems regarding the final yield of HBcAg. Several extraction and purification methods were tested and finally the antigen was purified up to 43% using sucrose density gradient centrifugation. The purified HBcAg retained its antigenicity, as confirmed by ELISA and western blot, while maintaining its CLP-structure as observed in TEM. In mice HBcAg intramuscularly delivered at 2×10µg triggered a significant response (serum anti-HBc titre around 150,000), being statistically equivalent to that induced by the reference antigen. Among anti-HBc IgG isotypes, IgG2a and then IgG1 were increasing during immune response. However IgG2b and IgG3 were also induced, especially in mice immunised with the plant-derived antigen. Analysis of the isotype profile indicates mainly Th1 polarisation, but completed with Th2 response. Obtained results indicate a considerable potential of plant-derived HBcAg as a therapeutic vaccine, since a mixed immune response with a stronger Th1 component is particularly required for treatment of CHB.

The computed tomography-based fractal analysis of trabecular bone structure may help in detecting decreased quality of bone before urgent spinal procedures.

BACKGROUND CONTEXT: To date, no reliable method is available to determine the parameters of bone density based on the routine spinal computed tomography (CT) in the emergency setup. We propose the use of fractal analysis to detect patients with poor quality of bone before urgent or semi-urgent spinal procedures. PURPOSE: This study aimed to validate the hypothesis that the CT-based fractal analysis of the trabecular bone structure may help in detecting patients with poor quality of bone before urgent spinal procedures. STUDY DESIGN: This is a retrospective analysis of prospectively collected data. METHODS: Patients in whom the dual-energy x-ray absorptiometry (DEXA) scan and lumbar spine CT were performed at an interval of no more than 3 months were randomly selected from a prospectively collected database. Diagnostic axial CT scans of L2, L3, and L4 vertebrae were processed to determine the fractal dimension (FD) of the trabecular structure of each spinal level. Box-count method and ImageJ 1.49 software were used. The FD was compared with the results of the DEXA scan: bone mineral density (BMD) and T-score by mean of correlation coefficients. Receiver operating characteristic curve analysis was later performed to determine the cutoff value of FD. RESULTS: A total of 102 vertebral levels obtained from 35 patients (mean age 60±18 years; 29 female) were analyzed. The FD was significantly higher in the group of patients with decreased bone density (DBD) (T-score<-1.0) (1.67 vs. 1.43; p<.0001) and negatively correlated with BMD (R Spearman, -0.53; p<.0001) and T-score (-0.49; p<.0001). Receiver operating characteristic curve analysis revealed that a cutoff value of FD>1.53 indicates DBD (p<.0001; area under the ROC curve [AUC], 0.84; 95% confidence interval [CI], 0.76-0.91). CONCLUSIONS: This study shows that fractal analysis of the lumbar spine CT images may be used to determine bone density before spinal instrumentation (eg, metastatic or traumatic cord compression). Further prospective studies comparing results of the fractal analysis of CT scans with quantitative CT (qCT) are warranted.

Fractal Analysis May Improve the Preoperative Identification of Atypical Meningiomas.

Background: There is no objective and readily accessible method for the preoperative determination of atypical characteristics of a meningioma grade. Objective: To evaluate the feasibility of using fractal analysis as an adjunctive tool to conventional radiological techniques in visualizing histopathological features of meningiomas. Methods: A group of 27 patients diagnosed with atypical (WHO grade II) meningioma and a second group of 27 patients with benign (WHO grade I) meningioma were enrolled in the study. Preoperative brain magnetic resonance (MR) studies (T1-wieghted, post-gadolinium) were processed and analyzed to determine the average fractal dimension (FDa) and maximum fractal dimension (FDm) of the contrast-enhancing region of the tumor using box-count method. FDa and FDm as well as particular radiological features were included in the logistic regression model as possible predictors of malignancy. Results: The cohort consisted of 34 women and 20 men, mean age of 62 ± 15 yr. Fractal analysis showed good interobserver reproducibility (Kappa >0.70). Both FDa and FDm were significantly higher in the atypical compared to the benign meningioma group (P < .0001). Multivariate logistic regression model reached statistical significance with P = .0001 and AUC = 0.87. The FDm, which was greater than 1.31 (odds ratio [OR], 12.30; P = .039), and nonskull base localization (OR, .052; P = .015) were confirmed to be statistically significant predictors of the atypical phenotype. Conclusion: Fractal analysis of preoperative MR images appears to be a feasible adjunctive diagnostic tool in identifying meningiomas with potentially aggressive clinical behavior.

Chest wall reconstruction after en bloc Pancoast tumour resection with the use of MatrixRib and SILC fixation systems: technical note.

STUDY DESIGN: Technical note. OBJECTIVE: In cases in which partial resection of the rib cage is accomplished with vertebrectomy, reconstruction of the chest wall may be challenging. That is because of lack of the anchor point which normally would be a proximal end of a rib or transverse process. We report a straightforward technique for chest wall reconstruction with the novel use of two systems of fixation commonly applied in spinal practice. METHODS: The operation of a squamous cell carcinoma (Pancoast tumour) of the right lung infiltrating T2, T3 and T4 vertebrae was performed though T4 lateral thoracotomy. Posterior instrumentation with transpedicular screws T1-3-5 on the left and T1-5 on the right side was followed with the right upper lobectomy and hemivertebrectomy. The laminae and facet joints of T2-T4 vertebrae were removed on the side of the tumour. An osteotomy was performed medial to the pedicle at the lateral aspect of the dural sac on the side of the tumour. Proximal parts of four adjacent ribs were removed allowing radical en bloc resection with tumour-free margins. The distal end of each of four rib plates used (MatrixRib Precontoured Plate system) was attached to the proximal end of the rib. The proximal end of the plate was then attached to the rod of posterior fixation construct with the use of a flexible polyethylene terephthalate (PeT) band of the SILC™ fixation system. The other end of the PeT band was then passed through the top-loading clamp subsequently attached to the rod of the posterior fixation. RESULTS: The patient did not require additional procedures for chest wall reconstruction. On the 7-month follow-up, in chest CT he was found with satisfactory expansion of the remaining lung tissue with proper spinal alignment and anatomical shape of the rib cage. CONCLUSIONS: The reported technique can be applied for chest wall reconstruction in cases of total or subtotal vertebrectomy accomplished with the resection extending towards rib cage. It appears to be straightforward, safe and effective allowing good cosmetic and functional outcome.

Posterior lumbar fixation in a kidney transplant recipient: logistics and perioperative challenges.

BACKGROUND: Kidney transplantation has become the ideal and successful treatment for medically suitable patients with established kidney disease. This results in increased likelihood of these patients developing unrelated conditions requiring surgery, including spinal surgery. There are only a few publications available regarding spinal patients with renal transplants. CASE REPORT: A 67-year-old patient presented with recurrent sciatica. Four years prior to this, he received a living donor kidney transplant. He was diagnosed with right L4 radiculopathy due to recurrent foraminal stenosis as a result of the grade I L4/5 spondylolisthesis. He was offered a reoperation including microdecompression and postero-lateral fixation and fusion. The renal transplant necessitated specific pre- and intraoperative considerations. The knee-chest position with extra padding was used to maintain the region of the renal transplant free from any pressure. The renal care was planned in detail by the transplant surgeons and nephrologists and shared with the ward doctors and on-call teams. The procedure was uneventful; there were no signs of intraoperative or postoperative acute renal injury. The patient was discharged 5 days postoperatively; all renal parameters remained within normal ranges and the postoperative plain films demonstrated satisfactory surgical results. CONCLUSIONS: The key to success was a multidisciplinary approach and detailed planning regarding pre-, intra- and postoperative care. The presented scheme of care might be useful when considering the posterior approach and prone positioning in kidney transplant recipients with spinal pathologies requiring surgical treatment.

Four-year trends in the treatment of cerebral aneurysms in Poland in 2009-2012.

BACKGROUND: The dilemma concerning the appropriate treatment of the intracranial aneurysms (IAs) has not yet been resolved and still remains under fierce debate. This study refers to the recent trends in the use of and outcomes related to coiling compared with clipping for unruptured and ruptured IAs in Poland over a 4-year period. METHODS: The analysis refers to treatment of IAs performed in Poland between 2009-2012. Patients' records were cross-matched by ICD-9 codes for ruptured SAH (430) or unruptured cerebral aneurysm (437.3) along with codes for clipping (39.51) and coiling (39.79, 39.72, or 39.52). Multivariable logistic regression was used to compare in-hospital deaths, hospital length of stay (LOS), therapy allocation and aneurysm locations in unruptured vs. ruptured and clipped vs. coiled groups. Differences in the number of procedures between 16 administrative regions were standardized per 100,000 people. RESULTS: In 2009-2012, 11,051 procedures were identified, including 5,968 ruptured and 5,083 unruptured aneurysms. Overall increase was 2.3 % in clipping and 13.1 % in coiling; a significant trend was found in endovascular procedures (p = 0.044). Ruptured aneurysms were clipped more frequently (OR = 1.66;); in unruptured IAs, endovascular procedure was preferred 3.5 times more than clipping. The annual in-hospital mortality was 7.6 % in clipping and 6.7 % in endovascular treatment. LOS was two times longer after clipping in unruptured aneurysms (OR = 2.013). After the procedures were standardized per 100,000 people, the average for Poland was established as 9.09 in 2009, 10.86 in 2010, 10.55 in 2011, and 11.49 in 2012. This index had the highest values in Mazovia (12.9, 2009; 15.4, 2010; 17.4, 2011; 18.6, 2012. CONCLUSIONS: Data analysis revealed an increase in overall number of IAs treated in Poland between 2009-2012. A significant upward trend of endovascular procedures was found, whereas the number of clipped aneurysms remained relatively steady over the study period.

The supraorbital keyhole approach via an eyebrow incision applied to obtain the olfactory bulb as a source of olfactory ensheathing cells--radiological feasibility study.

BACKGROUND. The purpose of the study was to test the suitability of supraorbital keyhole craniotomy with an eyebrow incision for obtaining olfactory bulb for therapeutic purposes. METHODS. Fifty three high-resolution axial head computed tomography images of patients with a mean age of 55 ± 15 years were used. The exclusion criterion was a pathology of the anterior skull base. The virtual keyhole supraorbital craniotomy was placed on each side of a three-dimensional skull model with respect to the anatomical landmarks. Trajectories of neurosurgical instrument transitions to the anterior and posterior aspects of olfactory grooves (OGs) were subsequently designed with the use of a neuronavigation planning station and measured with correction allowing the avoidance of collisions with skull base structures. Three types of anatomical configuration were divided, reflecting the extent of the correction needed to reach the bottom of OG. RESULTS. Simulation of the surgical access and consequent metrological analysis was performed on 97 skull sides - 9 (8.5%) sides were excluded due to the large frontal sinus. The mean length of the craniotomy basis was 30.71 mm, lengths of the anterior and posterior trajectories were 53.25 and 58.24 mm, respectively (p < 0.0001). In 37% of cases the value of the corrections exceeded the depth of OG. CONCLUSIONS. The supraorbital keyhole approach via an eyebrow incision may be applied to obtain the olfactory bulb as a source of olfactory ensheathing cells in over 60% of cases. Further verification and evaluation of the surgical handiness based on cadaver specimens is justifiable.

Transplantation of autologous olfactory ensheathing cells in complete human spinal cord injury.

Numerous studies in animals have shown the unique property of olfactory ensheathing cells to stimulate regeneration of lesioned axons in the spinal cord. In a Phase I clinical trial, we assessed the safety and feasibility of transplantation of autologous mucosal olfactory ensheathing cells and olfactory nerve fibroblasts in patients with complete spinal cord injury. Six patients with chronic thoracic paraplegia (American Spinal Injury Association class A-ASIA A) were enrolled for the study. Three patients were operated, and three served as a control group. The trial protocol consisted of pre- and postoperative neurorehabilitation, olfactory mucosal biopsy, culture of olfactory ensheathing cells, and intraspinal cell grafting. Patient's clinical state was evaluated by clinical, neurophysiological, and radiological tests. There were no adverse findings related to olfactory mucosa biopsy or transplantation of olfactory ensheathing cells at 1 year after surgery. There was no evidence of neurological deterioration, neuropathic pain, neuroinfection, or tumorigenesis. In one cell-grafted patient, an asymptomatic syringomyelia was observed. Neurological improvement was observed only in transplant recipients. The first two operated patients improved from ASIA A to ASIA C and ASIA B. Diffusion tensor imaging showed restitution of continuity of some white matter tracts throughout the focus of spinal cord injury in these patients. The third operated patient, although remaining ASIA A, showed improved motor and sensory function of the first spinal cords segments below the level of injury. Neurophysiological examinations showed improvement in spinal cord transmission and activity of lower extremity muscles in surgically treated patients but not in patients receiving only neurorehabilitation. Observations at 1 year indicate that the obtaining, culture, and intraspinal transplantation of autologous olfactory ensheathing cells were safe and feasible. The significance of the neurological improvement in the transplant recipients and the extent to which the cell transplants contributed to it will require larger numbers of patients.

Usefulness of intraoperative magnetic resonance ventriculography during endoscopic third ventriculostomy.

BACKGROUND: Endoscopic third ventriculostomy (ETV) is the preferred method for the treatment of noncommunicating hydrocephalus. The different success rates of ETV indicate the difficulties in predicting the success of this procedure. OBJECTIVE: To show the usefulness of intraoperative ventriculography performed by the low-field 0.15-T magnetic resonance imager Polestar N20 during ETV. METHODS: The study was conducted in 11 patients with noncommunicating hydrocephalus caused by tumors or cysts of the third ventricle (n = 5), nontumoral stenosis of the sylvian aqueduct (n = 3), and fourth ventricle outlet obstruction (n = 3). Intraoperative magnetic resonance (iMR) ventriculography was performed before and after the ETV. RESULTS: In each case, iMR-ventriculography was a safe procedure and determined the exact site of obstruction of cerebrospinal fluid flow. In all cases, iMR-ventriculography performed after ETV showed with the greatest accuracy the patency of the performed fenestrations, demonstrating in 9 patients good flow of the contrast from the third ventricle to the basal cisterns, restricted flow in 1 patient, and no flow in 1 patient. The results of ventriculography were consistent with the postoperative neurological status of operated-on patients. In 3 patients, the opinion of the surgeons about the patency of endoscopic fenestration, based on intraoperative observation of the third ventricle floor, was inconsistent with the results from iMR-ventriculography. CONCLUSION: Low-field iMR-ventriculography is a safe procedure that can be successfully applied during ETV to determine the site of obstruction in hydrocephalus and the patency of performed ventricle fenestration.

Usefulness of perfusion weighted magnetic resonance imaging with signal-intensity curves analysis in the differential diagnosis of sellar and parasellar tumors: preliminary report.

PURPOSE: The most common pituitary tumors are adenomas, which however may be mimicked by other tumors that can show a very similar appearance in plain MRI. The aim of our study was to evaluate the usefulness of perfusion weighted MR imaging (PWI), including signal-intensity curves analysis in the differential diagnosis of sellar/parasellar tumors. METHODS: Forty-one patients with sellar/parasellar tumors (23 macroadenomas, 10 meningiomas, 5 craniopharyngiomas, 1 intrasellar hemangioblastoma, 1 intrasellar prostate cancer metastasis, 1 suprasellar glioma), underwent plain MRI followed by PWI using a 1.5T unit. In each tumor, the mean and maximum values of relative cerebral blood volume (rCBV), as well as the relative peak height (rPH) and the relative percentage of signal intensity recovery (rPSR) were calculated. RESULTS: The high perfusion tumors were: macroadenomas, meningiomas, squamous-papillary type of craniopharyngiomas, hemangioblastoma, glioma and metastasis. The low perfusion neoplasms included adamantinomatous type of craniopharyngiomas. By comparing adenomas and meningiomas, we found statistically significant differences in the mean and maximum rCBV values (p=0.026 and p=0.019, respectively), but not in rPH and rPSR. The maximum rCBV values >7.14 and the mean rCBV values >5.74 with the typical perfusion curve were very suggestive of the diagnosis of meningioma. There were differences between adenomas and other high perfusion tumors in rPH and rPSR values. CONCLUSIONS: PWI can provide additional information helpful in differential diagnosis of sellar/parasellar tumors. In our opinion PWI, as an easy to perform and fast technique should be incorporated into the MR protocol of all intracranial neoplasms including sellar/parasellar tumors.