J. Soleman

The role of intraoperative magnetic resonance imaging in complex meningioma surgery

Intraoperative magnetic resonance imaging (iMRI) has gained importance in the treatment of gliomas and sellar tumors. In intracranial meningiomas, the extent of surgical tumor removal is one of the most important factors in the prevention of tumor recurrence and patient survival. Complex meningiomas located at the skull base or near eloquent brain regions show higher recurrence rates, morbidity and mortality. The aim of this study was to evaluate whether iMRI contributes to more extensive surgical resection in these tumors. Patients undergoing complex meningioma resection using iMRI from January 2007 to January 2011 were included in this study. The indication for iMRI-guided tumor resection included patients presenting with meningiomas located in the skull base or compressing eloquent brain areas in whom a radical resection was considered to be difficult. Intraoperative 0.15-T MRI scan (PoleStar; Medtronic Navigation, Louisville, CO, USA) was performed before and after maximal possible resection using standard microsurgical and neuronavigation techniques. All patients underwent fluorescence-guided resection. The following data were analyzed: tumor localization, histological grade, Simpson resection grade, duration of the procedure, iMRI scan time, iMRI findings, resection extent based on postresection iMRI, hospitalization time, surgical complications and outcome, and MRI follow-up 2-27months postoperation. Twenty-seven consecutive patients undergoing complex meningioma resection using iMRI were included. In this series, only one patient (3.4%) underwent resection of tumor remnant after iMRI, although without improvement of the Simpson resection grade. Temporary neurologic deficits were found in 8 patients (27.6%) postoperatively, whereas 11 patients (37.9%) had permanent postoperative neurologic deficits. In one case (3.4%), fatal postoperative bleeding occurred which was not detected by iMRI. Our results show that iMRI has no influence on intraoperative strategy in terms of resection grade or detection of early postoperative complications. The benefits of iMRI in complex meningioma surgery are therefore doubtful; however, it may still prove to be effective in certain subsets of complex meningiomas.

Is the use of antibiotic-impregnated external ventricular drainage beneficial in the management of iatrogenic ventriculitis?

BackgroundProfound evidence substantiates significantly reduced risk of catheter-related infections with prophylactic use of rifampin- and clindamycin-impregnated silicone catheters (Bactiseal®, Codman Johnson & Johnson, Raynham, MA, USA) for external ventricular drainage (EVD). However, whether Bactiseal®-EVD (B-EVD) influences the treatment of EVD-related ventriculitis remains controversial.MethodsWe performed a retrospective analysis of patients who developed ventriculitis after EVD or ventriculoperitoneal (VP) shunt placement and consequently underwent either placement of B-EVD (group 1) or a standard non-antibiotic-impregnated EVD (group 2). Analyzed parameters included demographic and clinical data, hospitalization time, time until remission of the infection parameters, detection of new bacterial resistance on antibiograms, and clinical outcome in terms of the modified Rankin scale (mRS).ResultsTime until remission of cerebrospinal fluid (CSF) pleocytosis was significantly longer in patients undergoing B-EVD (8u2009±u20093.8xa0days; nu2009=u200915; group 1) than in patients who underwent standard EVD (5.1u2009±u20091.8xa0days; nu2009=u200910; group 2). There was no significant difference between both groups for the time until polymorphonuclear cells dropped below 50% of peak value (5.8u2009±u20091.6 vs. 4.1u2009±u20092.9xa0days), CRP dropped below 10xa0mg/l (4.2u2009±u20093.5 vs. 5.6u2009±u20093.3xa0days), the time of plasma neutrophil remission (5.7u2009±u20092.6 vs. 5.3u2009±u20093.2xa0days) and hospitalization time (28u2009±u200912.5 vs. 35u2009±u200919.4xa0days). The mRS for both groups was 2. Development of new antibiotic resistance did not occur in either group.ConclusionsThis retrospective pilot study indicates that B-EVD might have no major advantage in the management of EVD or VP-shunt-related ventriculitis. Based on published reports and the results of this study, data support only the prophylactic use of B-EVD for prevention of EVD-related infections. Prospective randomized clinical trials are warranted to further evaluate the role of B-EVD in the treatment of ventriculitis.

Outcome after In-Hospital Rebleeding of Rupture of Intracranial Aneurysms.

BACKGROUNDnAfter initial subarachnoidal hemorrhage (SAH), due to an intracranial aneurysm, rebleeding is known as a factor influencing the devastating outcome. This complication has been reported to occur in ∼ 4% of the patients admitted with aneurysmal SAH. Moreover, ultra-early rebleeding within the first 24 hours might occur in 9 to 17% of the cases (40-87% appearing in the first 6 hours). Risk factors influencing this situation include increasing aneurysm size, deterioration of neurologic deficits, angiography within 3 hours of bleeding, sentinel symptoms, and the loss of consciousness at initial bleeding. The aim of this retrospective study was to assess factors and potential risk factors related to rebleeding, specifically the interval from initial SAH to rebleeding.nnnMATERIAL AND METHODSnFrom a consecutive series of 243 patients who experienced aneurysmal SAH, we identified 28 patients (11.5%; 12 men, 16 women; mean age: 58u2009±u200910 years) who developed in-hospital rebleeding during this 49-month study (2009-2013). Demographic, radiologic, and clinical characteristics including hemodynamic parameters were analyzed.nnnRESULTSnRebleeding was fatal in 20 of the 28 patients (71%) and caused severe neurologic deficits (Glasgow Outcome Scale: 3; modified Rankin Scale: 5) in 3 (29%) of the remaining 8 survivors. Rebleeding occurred within the first 4 hours in 15 patients (54%) within 7, 24, and 48 hours in 17 (61%), 6 (21%), and 1 (4%) patient, respectively. In this series, the medium arterial blood pressure was 98u2009±u200911u2009mm Hg at arrival at the emergency department, 88u2009±u200910u2009mm Hg before rebleeding, and it dramatically increased to 124u2009±u200922u2009mm Hg at rebleeding. For the patients with rebleeding after aneurysmal SAH, initial sentinel headache (79%) and loss of consciousness (68%) were the common presenting symptoms. The World Federation of Neurological Societies grade was documented on admission as follows: 1-3 (nu2009=u200914 [50%]); 4-5 (nu2009=u200914 [50%]). A Fisher grade 4 was documented in 82% of the cases on the initial computed tomography (CT) scan. Overall, 42% of the cases underwent endovascular (nu2009=u20096) or microsurgical occlusion of the aneurysm (nu2009=u20096). The rest of the patients (nu2009=u200916, 58%) did not underwent occlusion of the aneurysm because of poor clinical status. Digital substraction angiography was performed in 61% of the cases.nnnCONCLUSIONnPossible factors increasing the risk of in-hospital rebleeding after aneurysmal SAH are high systolic blood pressure, sentinel headache, initial loss of consciousness, poor Hunt and Hess grade, high Fisher grade on initial CT, large aneurysm size, and the performance of angiography. Most of the rebleedings in patients in our center are likely to occur within 7 hours after admission. Based on our findings, we suggest that mobilization of the patient and maneuvers including invasive procedures should be restricted to a minimum during intensive care unit treatment prior to the occlusion of the ruptured aneurysm. Stabilization of blood pressure with adequate sedation and analgesia prior to occlusion can be considered preventive strategies against rebleeding.

An Interlaminotomy New Zealand White Rabbit Model to Evaluate Novel Epidural Strategies.

OBJECTIVEnThe New Zealand White (NZW) rabbit model is an established animal model for examining surgical methods to prevent epidural scar formation after spine surgery. As most approaches include complete laminectomy of the rabbit vertebra, this procedure is associated with high morbidity and mortality rates. We examined a less invasive technique, the microsurgical interlaminotomy, for testing epidural substance application in the rabbit spine.nnnMETHODSnSurgery was performed in the cadaver rabbit spine to evaluate the approach before performing it in NZW rabbits. All surgical procedures were performed under an operation microscope. Female rabbits with a mean weight of 4770u2009gu2009 ± u2009240u2009g were used. Neurologic symptoms were analyzed based on predefined scores. After resection of the spinal process, the caudal part of the upper lamina was resected using a drill and a 1-mm Kerrison punch. The yellow ligament was resected resulting in a dural exposure of ∼ 5u2009×u200910 mm.nnnRESULTSnEight pilot interlaminotomies were performed on three cadaveric spines to establish the surgical approach. Twenty-one NZW rabbits were then operated on using the interlaminotomy model. Three rabbits (14.3%) died during surgery due to anesthesia-related complications. Two rabbits (9.5%) showed partial paresis of the lower extremities and one (4.8%) a complete paraplegia. The remaining 15 rabbits (71.4%) had an uneventful recovery without neurologic symptoms. The mean surgical duration was 88 +/- 28 minutes.nnnCONCLUSIONnThe rabbit interlaminotomy model is associated with few neurologic deficits and a relatively short operating time.

Transforaminal Lumbar Interbody Fusion Using LOOPî PEEK CageImplants: Safety, Feasibility, Radiographic and Clinical Outcome

Objective: A variety of newly designed grafts for transforaminal lumbar interbody fusion (TLIF) have been introduced for clinical application. Biomechanical properties of the LOOP® PEEK cage (Medtronic GmbH, Meerbusch, Germany) have been shown in cadaver laboratory investigations, but not in clinical studies so far. In this study we analyze the safety, clinical and radiological outcome of the LOOP® PEEK cage implant in a clinical setting. nMethods: Forty one consecutive patients undergoing fluoroscopic-guided posterior pedicle screw fixation combined with TLIF using the LOOP® PEEK cage for degenerative spine diseases between January 2010 and December 2011 were included. Time intervals for follow-up, clinical and radiological outcome data collection were at 1, 3 and 12 months. Visual analog pain scales (VAS), neurological exam, patient-reported SF-12®, CT- scans and plain x-rays of the lumbar spine were used as clinical and radiologic outcome measures. Following data were recorded for safety evaluation: procedure duration, intraoperative blood loss, number of levels fused, intraoperative complications, hospitalization time, and postoperative complications. nResults: A total of 49 cages were implanted during 41 procedures with an average procedure time of 225.25 minutes. Four patients (9.8%) experienced a dural tear, While new sensory and motor deficits were seen in 2 (4.9%) and 1 (2.4%) patients respectively. complications were not associated with implant insertion. Significantly reduced pain scores (p<0.05, paired t-test) were reported by 29 patients (70%) at 1, 3 and 12 months. SF-12® results showed PCS and MCS scores below the healthy population average, one year post-op. Cage dislocation was observed in 2 (4.9%) patients, one required late revision. Implant fracture did not occur. Inchoate fusion of the vertebra was seen in 39 patients (95.1%) at one year. nConclusion: TLIF procedure combined with lumbar fusion using LOOP®-PEEK cage, provides a safe and feasible intraoperative alternative as well as good clinical and radiologic outcome, without increasing the overall complication rate of TLIF procedures.