Two-stage endoscopic assisted approach for large pineal region and falcotentorial meningioma: first stage paramedian supracerebellar infratentorial approach, second stage interhemispheric occipital transtentorial approach: surgical cases and anatomical study.

Resection of complex falcotentorial meningiomas, growing along the pineal region (PR), and posterior incisural space (PIS) represents a neurosurgical challenge. Here, we present our strategy for effective resection of large falcotentorial meningiomas applying a paramedian supracerebellar infratentorial and interhemispheric occipital transtentorial approach in staged surgeries. We further systematically compared the effectiveness of midline (MSIA) and paramedian (PSIA) supracerebellar infratentorial, as well as interhemispheric occipital transtentorial approaches (IOTA) to operate along the PR and PIS in 8 cadaveric specimens. The staged PSIA and IOTA enabled successful resection of both falcotentorial meningiomas with an uneventful postoperative course. In our anatomo-morphometrical study, superficial vermian veins at an average depth of 11.38 ± 1.5 mm and the superior vermian vein (SVV) at 54.13 ± 4.12 mm limited the access to the PIS during MSIA. MSIA required sacrifice of these veins and retraction of the vermian culmen of 20.88 ± 2.03 mm to obtain comparable operability indexes to PSIA and IOTA. Cerebellar and occipital lobe retraction averaged 14.31 ± 1.014 mm and 14.81 ± 1.17 mm during PSIA and IOTA respectively, which was significantly lower than during MSIA (p < 0.001). Only few minuscule veins were encountered along the access through PSIA and IOTA. The application of PSIA provided high operability scores around the pineal gland, ipsilateral colliculus and splenium, and acceptable scores on contralateral structures. The main advantage of IOTA was improving surgical maneuvers along the ipsilateral splenium. In summary, IOTA and PSIA may be advantageous in terms of brain retraction, vein sacrifice, and operability along the PR and PIS and can be effective for resection of complex falcotentorial meningiomas.

An age-dependent outcome analysis of microvascular decompression and percutaneous thermocoagulation in trigeminal neuralgia.

BACKGROUND: Trigeminal neuralgia (TN) is a severe pain condition and the most common facial neuralgia. While microvascular decompression (MVD) presents an excellent treatment in neurovascular compression cases, percutaneous thermocoagulation (PT) of the ganglion Gasseri is an alternative option. This study aimed to evaluate post-operative complication rate and outcome of both treatment strategies related to the patient's age. METHODS: The medical records of all patients with the diagnosis of trigeminal neuralgia undergoing an MVD or PT of the ganglion Gasseri (between January 2007 and September 2017) were reviewed to determine the efficacy and the complication rate of both methods in regard to the patient's age. RESULTS: Seventy-nine patients underwent MVD surgery and 39 a PT. The mean age of patients in the MVD group was 61 years and 73 years in the PT group. There were 59 (50%) female patients. Nerve-vessel conflict could be identified in 78 (98.7%) MVD and 17 (43.6%) PT patients on preoperative MRI. Charlson comorbidity index was significantly higher in PT group (2.4 (1.8) versus 3.8 (1.8) p < 0.001). The Barrow pain score (BPS) at the last follow-up demonstrated higher scores after PT (p = 0.007). The complication rate was markedly higher in PT group, mostly due to the facial hypesthesia (84.6% versus 27.8%; p < 0.001). Mean symptom-free survival was significantly shorter in the PT group (9 vs. 26 months, p < 0.001). It remained statistically significant when stratified into age groups: (65 years and older: 9 vs. 18 months, p = 0.001). Duration of symptoms (OR 1.005, 95% CI 1.000-1.010), primary procedure (OR 6.198, 95% CI 2.650-14.496), patient age (OR 1.033, 95% CI 1.002-1.066), and postoperative complication rate (OR 2.777, 95% CI 1.309-5.890) were associated with treatment failure. CONCLUSION: In this patient series, the MVD is confirmed to be an excellent treatment option independent of patient's age. However, while PT is an effective procedure, time to pain recurrence is shorter, and the favorable outcome (BPS 1 and 2) rate is lower compared to MVD. Hence MVD should be the preferred treatment and PT should remain an alternative in very selected cases when latter is not possible but not in the elderly patient per se.

Evaluation of robot-guided minimally invasive implantation of 2067 pedicle screws.

Objective Recent studies have investigated the role of spinal image guidance for pedicle screw placement. Many authors have observed an elevated placement accuracy and overall improvement of outcome measures. This study assessed a bi-institutional experience following introduction of the Renaissance miniature robot for spinal image guidance in Europe. Methods The medical records and radiographs of all patients who underwent robot-guided implantation of spinal instrumentation using the novel system (between October 2011 and March 2015 in Mainz and February 2014 and February 2016 in Regensburg) were reviewed to determine the efficacy and safety of the newly introduced robotic system. Screw position accuracy, complications, exposure durations to intraoperative radiation, and reoperation rate were assessed. Results Of the 413 surgeries that used robotic guidance, 406 were via a minimally invasive approach. In 7 cases the surgeon switched to conventional screw placement, using a midline approach, due to referencing problems. A total of 2067 screws were implanted using robotic guidance, and 1857 screws were evaluated by postoperative CT. Of the 1857 screws, 1799 (96.9%) were classified as having an acceptable or good position, whereas 38 screws (2%) showed deviations of 3-6 mm and 20 screws (1.1%) had deviations > 6 mm. Nine misplaced screws, implanted in 7 patients, required revision surgery, yielding a screw revision rate of 0.48% of the screws and 7 of 406 (1.7%) of the patients. The mean ± SD per-patient intraoperative fluoroscopy exposure was 114.4 (± 72.5) seconds for 5.1 screws on average and any further procedure required. Perioperative and direct postoperative complications included hemorrhage (2 patients, 0.49%) and wound infections necessitating surgical revision (20 patients, 4.9%). Conclusions The hexapod miniature robotic device proved to be a safe and robust instrument in all situations, including those in which patients were treated on an emergency basis. Placement accuracy was high; peri- and early postoperative complication rates were found to be lower than rates published in other series of percutaneous screw placement techniques. Intraoperative radiation exposure was found to be comparable to published values for other minimally invasive and conventional approaches.

In vivo multiphoton tomography and fluorescence lifetime imaging of human brain tumor tissue.

High resolution multiphoton tomography and fluorescence lifetime imaging differentiates glioma from adjacent brain in native tissue samples ex vivo. Presently, multiphoton tomography is applied in clinical dermatology and experimentally. We here present the first application of multiphoton and fluorescence lifetime imaging for in vivo imaging on humans during a neurosurgical procedure. We used a MPTflex™ Multiphoton Laser Tomograph (JenLab, Germany). We examined cultured glioma cells in an orthotopic mouse tumor model and native human tissue samples. Finally the multiphoton tomograph was applied to provide optical biopsies during resection of a clinical case of glioblastoma. All tissues imaged by multiphoton tomography were sampled and processed for conventional histopathology. The multiphoton tomograph allowed fluorescence intensity- and fluorescence lifetime imaging with submicron spatial resolution and 200 picosecond temporal resolution. Morphological fluorescence intensity imaging and fluorescence lifetime imaging of tumor-bearing mouse brains and native human tissue samples clearly differentiated tumor and adjacent brain tissue. Intraoperative imaging was found to be technically feasible. Intraoperative image quality was comparable to ex vivo examinations. To our knowledge we here present the first intraoperative application of high resolution multiphoton tomography and fluorescence lifetime imaging of human brain tumors in situ. It allowed in vivo identification and determination of cell density of tumor tissue on a cellular and subcellular level within seconds. The technology shows the potential of rapid intraoperative identification of native glioma tissue without need for tissue processing or staining.

Medication reconciliation for patients undergoing spinal surgery.

PURPOSE: In recent years, a marked increase of spinal operations prompted a debate on quality issues. Besides obvious factors, such as the surgical technique, medication safety has been identified as one of the major risk factors for patients undergoing anesthesia and surgery. While the issue has already been addressed by hospital pharmacist and anesthesiologists, the prescription of correct medication remains within the surgeons' responsibility. We, therefore, investigated medication-related errors in spinal instrumentation patients and applied current medication reconciliation strategies. METHODS: We performed a data survey on all patients undergoing spinal instrumentation in 2011. Risk factors for medication safety were identified and prioritized. Specific counter-measures were introduced in 2012 and evaluated in 2013. RESULTS: 147 patients were included in the 2011 and 162 in the 2013 survey. As top five risk factors we identified the preoperative stopping of medication, recording the medication history, prescription process of postoperative analgetics and anticoagulants and the medication list at discharge. Specific counter-measures included standardization of preparations, doses and the prescription process and improving access to this information (online and via a smartphone application). In elective patients, recording the medication histories was delegated to a hospital pharmacist and informative flyers and posters were used to integrate the patients themselves into the process. Counter-measures directed against the first four risk factors resulted in a significant reduction of medication errors. The last risk factor was targeted by instructing the responsible staff only, which proved to be a rather ineffective measure. CONCLUSIONS: Medication safety could be significantly improved by implementation of counter-measures specific to the identified risk factors.

Minimally invasive instrumentation of uncomplicated cervical fractures.

PURPOSE: Many authors favor conservative treatment options in oligo-symptomatic non-dislocated cervical fractures. This is mainly because of adverse events, anesthesia times and blood loss associated with surgical treatment of these injuries. We, therefore, sought to minimize the invasiveness of the surgical treatment of simple cervical fractures using image-guidance and a percutaneous approach. METHODS: Iso-C3D-based image guidance was used to place unilateral lag screws and conventional screws in pedicles, isthmi and lateral masses C1-C6. The navigation reference marker array was attached to the Mayfield clamp avoiding any additional skin incisions. Drilling of the screws trajectories was performed using a high speed drill with diamond tip, minimizing the risk of dislocations of cervical vertebrae and/or bone fragments relative to the iso-C3D scan to which the navigation system was registered. RESULTS: Image-guided percutaneous placement of cervical pedicle, isthmic and lateral mass screws resulted in correct screw placement in all six cases (three hangman fractures, three odontoid fracture Anderson 2 in elderly patients and one C6 posttraumatic pedicular pseudoarthrosis). Average blood loss was 194 ml, total average operating time 106 min and average X-ray time 3.8 min (395 cGy/cm(2)) including iso-C3D imaging. CONCLUSION: The technique presented here was found to be a feasible minimally invasive treatment option for uncomplicated cervical fractures. Besides to our best knowledge, we here present the first percutaneous implantation of lateral mass screws.

Interface transition checklists in spinal surgery.

ISSUE: Recently, quality tools have been promoted to improve patient safety and process efficiency in healthcare. While surgeons primarily focused on surgical issues, like infection rates or implant design, we introduced pre-admission and preoperative checklists in the early 2000s. INITIAL ASSESSMENT: To assess the efficiency of these tools in a neurosurgical department, we performed a survey of all spinal instrumentation patients operated in 2011 (n = 147). The results revealed several problems. CHOICE OF SOLUTION: We consequently redesigned the checklists accompanied by flanking measures, such as written  and online accessible standards. Furthermore, the staff was trained to use the updated quality tools. IMPLEMENTATION: The measures were implemented in 2012. EVALUATION: Results were re-evaluated in a second survey in 2013 (n = 162). We found that the use of pre-admission checklists significantly increased from 47 to 96%, while the use of preoperative checklists significantly decreased from 86 to 75%. Within the same period, the quality and completeness of the checklists did, however, increase, so that in 2013, 43% of the patients had a completely processed preoperative checklist, compared to 29% in 2011. LESSONS LEARNED: The introduction of checklists alone did not in itself guarantee an improved workflow. The introduction must be accompanied by other measures, like written standards and regular training of employees. Otherwise, the positive effect wears off quickly. Nevertheless, we could show that the stringent application of quality tools can induce a sustainable change. Our data further suggest that the clear and traceable delegation of responsibilities is of high importance.

Combined suture and clipping for the reconstruction of a ruptured blister-like aneurysm.

Blister-like aneurysms of the internal carotid artery (ICA) present a severe therapeutical challenge. While several reconstructive techniques are in use in case of acute rupture sacrifice of the parent vessel may be required. We present a combined technique of micro-sutures and clip application to repair the parent vessel in an intraoperatively ruptured blister-like aneurysm. Following temporary trapping of an intraoperatively ruptured 7-mm blister-like aneurysm four 8-0 nylon sutures were applied to adapt the vessel walls and support the branches of subsequently applied mini-clips. The combination of micro-sutures and mini-clips might be a valuable alternative to direct clipping or suturing in some cases with intraoperative rupture of blister-like aneurysms.

Variants of the Anterior Subtemporal Approach to the Gasserian Ganglion and Related Structures: An Anatomical Study With Relevant Implications for Keyhole Surgery.

BACKGROUND: The advantages and limitations of different craniotomy positions and approach trajectories to the gasserian ganglion (GG) and related structures using an anterior subtemporal approach have not been studied systematically. Knowledge of these features is of importance when planning keyhole anterior subtemporal (kAST) approaches to the GG to optimize access and minimize risks. METHODS: Eight formalin-fixed heads were used bilaterally to assess temporal lobe retraction (TLR), trigeminal exposure, and relevant anatomical aspects of extra- and transdural classic anterior subtemporal (CLAST) approaches compared with slightly dorsally and ventrally allocated corridors. RESULTS: TLR to the GG and foramen ovale was found to be lower via the CLAST approach (P < 0.001). Using the ventral variant, TLR to access the foramen rotundum was minimized (P < 0.001). The overall TLR was maximal using the dorsal variant (P < 0.001) owing to interposition of the arcuate eminence. An extradural CLAST approach required wide exposure of the greater petrosal nerve (GPN) and middle meningeal artery (MMA) sacrifice. Both maneuvers were spared using a transdural approach. Using CLAST, medial dissection >39 mm can enter the Parkinson triangle, jeopardizing the intracavernous internal carotid artery. The ventral variant enabled access to the anterior portion of the GG and foramen ovale without the need for MMA sacrifice or GPN dissection. CONCLUSIONS: The CLAST approach provides high versatility to approach the trigeminal plexus, minimizing TLR. However, an extradural approach jeopardizes the GPN and requires MMA sacrifice. The risk of cavernous sinus violation exists when progressing medially beyond 4 cm. The ventral variant has some advantages to access the ventral structures and avoid MMA and GPN manipulation. In contrast, the usefulness of the dorsal variant is rather limited owing to the greater TLR required.

Management of C2 fractures using Iso-C(3D) guidance: a single institution's experience.

BACKGROUND: About 20 % of cervical fractures involve the C2 vertebra. Many surgical techniques have been proposed according to the type of fracture. However, morbidity and mortality of these procedures is often high, which can be attributed to the old age and significant co-morbidities of the affected population and the complex anatomy of C2. To target the latter, several authors have applied iso-C(3D) guidance for most of the common techniques. We here present our experience using a fixed protocol and iso-C(3D) guidance in all cases of traumatic C2 fractures. METHODS: Sixteen patients were operated upon between April 2011 and April 2012 using Iso-C(3D) guidance, following a fixed routine protocol. The screw position was verified by CT-scanning. Intraoperative and clinical parameters were evaluated. RESULTS: Six patients received anterior lag-screw fixation of odontoid fractures. Two underwent isolated posterior lag-screw fixation of hangman's fracture. C1 and/or C3 lateral mass, and/or C2 isthmic screws were placed in eight patients. No screw had to be revised, 3 minor breachings of the cortical bone of <2 mm were observed.The same standard protocol for draping, registration of the navigation and Iso-C(3D) guided drilling could be applied for anterior and posterior procedures, leaving only two variables. This led to rapid acceptance of the technique among OR-staff and surgeons, who felt comfortable with iso-C(3D) guidance after only five cases. CONCLUSIONS: Iso-C(3D) guidance is a safe and straightforward technique for anterior and posterior screw placement in the upper cervical spine.

Endoscopic-assisted paramedian supracerebellar infratentorial approach to the posterior portion of the third ventricle. Anatomical study and surgical cases.

BACKGROUND: To date, morphometrical data providing a systematic quantification of accessibility and operability parameters to the boundaries of the posterior portion of the third ventricle (PTV) when applying an endoscopic-assisted paramedian supracerebellar infratentorial approach (EPSIA) are lacking. We performed an anatomical study and complemented our findings with surgical cases. METHODS: Eight EPSIAs towards the PTV were performed in cadaveric specimens. Optimal approach angles (OA), surgical freedom (SF) and operability indexes (Oi) to the PTV boundaries were assessed. Additionally, a 54-year-old man and 33-year-old woman were operated on PTV tumors applying the EPSIA. RESULTS: Sagittal OA to ventricle's roof and floor was 36±1.4° and 25.5±3.5° respectively, axial OA to the ipsilateral and contralateral ventricle's wall were 9.5±1.3° and 28.5±1.6°. SF was maximal on the contralateral wall (121.2±19.3mm2), followed by the roof (112.7±18.8mm2), floor (106.6±19.2mm2) and ipsilateral wall (94.1±15.7mm2). SF was significantly lower along the ipsilateral compared the contralateral wall (p<0.01) and roof (p<0.05). Facilitated surgical maneuvers with multiangled exposure were possible up to 8.5±1.07mm anterior to ventricle's entrance, whereas surgical maneuvers were possible but difficult up to 15.25±3.7mm. Visualization of more anterior was possible up to a distance of 27±2.9mm, but surgical maneuvers were barely feasible. EPSIA enabled successful resection of both PTV tumors and postoperative course was uneventful. CONCLUSIONS: EPSIA can be effective for approaching the PTV, enabling surgery along all boundaries, but especially on its roof and contralateral wall. In the not-enlarged ventricle, surgical maneuvers are feasible up to the level of the Monro foramen, becoming more limited anteriorly.

Microsurgical fenestration of perineural cysts to the thecal sac at the level of the distal dural sleeve.

BACKGROUND: Surgery for symptomatic sacral perineural cysts remains an issue of discussion. Assuming micro-communications between the cyst and thecal sac resulting in a valve mechanism and trapping of CSF as a pathomechanism, microsurgical fenestration from the cyst to the thecal sac was performed to achieve free CSF communication. METHODS: In 13 consecutive patients (10 female, 3 male), MRI revealed sacral perineural cysts and excluded other pathologies. Micro-communication between the thecal sac and the cysts was shown by delayed contrast filling of the cysts on postmyelographic CT. Surgical fenestration achieved free CSF communication between the thecal sac and cysts in all patients. The patient histories, follow-up examinations and self-assessment scales were analyzed. Symptoms at initial presentation included lumbosacral pain, pseudoradicular symptoms, genital pain and urinary dysfunction. Mean follow-up was 10.7 ± 6.6 months. FINDINGS: Besides one CSF fistula, no surgical complications were observed. Five patients did not improve after surgery; in four of these cases multiple cysts were found, but small and promptly filling cysts remained untreated. Seven patients reported lasting benefit following surgery; three of these had single cysts, and all had cysts >1 cm. One patient initially benefited from cyst fenestration but experienced recurrent pain within 2 months postoperatively. Re-myelography revealed delayed contrast filling of the recurrent cyst; however, surgical revision did not lead to an improvement despite successful fenestration and collapse of the cyst revealed by postoperative imaging. CONCLUSIONS: Microsurgical fenestration of sacral perineural cysts to the thecal sac is a surgical approach that has shown success in the treatment of lumbosacral pain, pseudoradicular symptoms, genital pain and urinary dysfunction associated with sacral perineural cysts. Our analysis, however, shows that mainly patients with singular large cysts benefit from this treatment.

Muscle-driven and torque-driven centrodes during modeled flexion of individual lumbar spines are disparate.

Lumbar spine biomechanics during the forward-bending of the upper body (flexion) are well investigated by both in vivo and in vitro experiments. In both cases, the experimentally observed relative motion of vertebral bodies can be used to calculate the instantaneous center of rotation (ICR). The timely evolution of the ICR, the centrode, is widely utilized for validating computer models and is thought to serve as a criterion for distinguishing healthy and degenerative motion patterns. While in vivo motion can be induced by physiological active structures (muscles), in vitro spinal segments have to be driven by external torque-applying equipment such as spine testers. It is implicitly assumed that muscle-driven and torque-driven centrodes are similar. Here, however, we show that centrodes qualitatively depend on the impetus. Distinction is achieved by introducing confidence regions (ellipses) that comprise centrodes of seven individual multi-body simulation models, performing flexion with and without preload. Muscle-driven centrodes were generally directed superior-anterior and tail-shaped, while torque-driven centrodes were located in a comparably narrow region close to the center of mass of the caudal vertebrae. We thus argue that centrodes resulting from different experimental conditions ought to be compared with caution. Finally, the applicability of our method regarding the analysis of clinical syndromes and the assessment of surgical methods is discussed.

Comparison of Unruptured Intracranial Aneurysm Treatment Score and PHASES Score in Subarachnoid Hemorrhage Patients With Multiple Intracranial Aneurysms.

Objective: Unruptured Intracranial Aneurysm (UIA) Treatment Score (UIATS) and PHASES score are used to inform treatment decision making for UIAs (treatment or observation). We assessed the ability of the scoring systems to discriminate between ruptured aneurysms and UIAs in a subarachnoid hemorrhage (SAH) cohort with multiple aneurysms. Methods: We retrospectively applied PHASES and UIATS scoring to the aneurysms of 40 consecutive patients with SAH and multiple intracranial aneurysms. Results: PHASES score discriminated better between ruptured aneurysms and UIAs than UIATS. PHASES scores and the difference between the UIATS subscores were higher for ruptured aneurysms compared with UIAs, which reached significance for the PHASES score. PHASES score estimated a low 5-year rupture risk in a larger proportion of the UIAs (≤0.7% in 62.3%, ≤1.7% in 98.4%) than of the ruptured aneurysms (≤0.7% in 22.5%, ≤1.7% in 82.5%). In the 40 ruptured aneurysms, UIATS provided recommendation for treatment in 11 (27.5%), conservative management in 14 (35.0%), and was inconclusive in 15 cases (37.5%). In the 61 UIAs, UIATS recommended treatment in 16 (26.2%), conservative management in 29 (47.5%), and was inconclusive in 16 (26.2%) cases. Conclusion: Similar to previous SAH cohorts, a significant proportion of the ruptured aneurysms exhibited a low-rupture risk. Nevertheless, PHASES score discriminated between ruptured aneurysms and UIAs in our cohort; the lower discriminatory power of UIATS was due to high weights of aneurysm-independent factors. We recommend careful integration of the scores for individual decision making. Large-scale prospective trials are required to establish score-based treatment strategies for UIAs.

Load Distribution in the Lumbar Spine During Modeled Compression Depends on Lordosis.

Excessive or incorrect loading of lumbar spinal structures is commonly assumed as one of the factors to accelerate degenerative processes, which may lead to lower back pain. Accordingly, the mechanics of the spine under medical conditions, such as scoliosis or spondylolisthesis, is well-investigated. Treatments via both conventional therapy and surgical methods alike aim at restoring a "healthy" (or at least pain-free) load distribution. Yet, surprisingly little is known about the inter-subject variability of load bearings within a "healthy" lumbar spine. Hence, we utilized computer tomography data from 28 trauma-room patients, whose lumbar spines showed no visible sign of degeneration, to construct simplified multi-body simulation models. The subject-specific geometries, measured by the corresponding lumbar lordosis (LL) between the endplates of vertebra L1 and the sacrum, served as ceteris paribus condition in a standardized forward dynamic compression procedure. Further, the influence of stimulating muscles from the M. multifidus group was assessed. For the range of available LL from 28 to 66°, changes in compressive and shear forces, bending moments, as well as facet joint forces between adjacent vertebrae were calculated. While compressive forces tended to decrease with increasing LL, facet forces were tendentiously increasing. Shear forces decreased between more cranial vertebrae and increased between more caudal ones, while bending moments remained constant. Our results suggest that there exist significant, LL-dependent variations in the loading of "healthy" spinal structures, which should be considered when striving for individually appropriate therapeutic measures.

First-line treatment of malignant glioma with carmustine implants followed by concomitant radiochemotherapy: a multicenter experience.

Randomized phase III trials have shown significant improvement of survival 1, 2, and 3 years after implantation of 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) wafers for patients with newly diagnosed malignant glioma. But these studies and subsequent non-phase III studies have also shown risks associated with local chemotherapy within the central nervous system. The introduction of concomitant radiochemotherapy with temozolomide (TMZ) has later demonstrated a survival benefit in a phase III trial and has become the current treatment standard for newly diagnosed malignant glioma patients. Lately, this has resulted in clinical protocols combining local chemotherapy with BCNU wafers and concomitant radiochemotherapy with TMZ although this may carry the risk of increased toxicity. We have compiled the treatment experience of seven neurosurgical centers using implantation of carmustine wafers at primary surgery followed by 6 weeks of radiation therapy (59-60 Gy) and 75 mg/m(2)/day TMZ in patients with newly diagnosed glioblastoma followed by TMZ monochemotherapy. We have retrospectively analyzed the postoperative clinical course, occurrence and severity of adverse events, progression-free interval, and overall survival in 44 patients with newly diagnosed glioblastoma multiforme. All patients received multimodal treatment including tumor resection, BCNU wafer implantation, and concomitant radiochemotherapy. Of 44 patients (mean age 59 ± 10.8 years) with glioblastoma who received Gliadel wafer at primary surgery, 28 patients (64%) had died, 16 patients (36%) were alive, and 15 patients showed no evidence of clinical or radiographic progression after a median follow-up of 15.6 months. At time of analysis of adverse events in this patient population, the median overall survival was 12.7 months and median progression-free survival was 7.0 months. Surgical, neurological, and medical adverse events were analyzed. Twenty-three patients (52%) experienced adverse events of any kind including complications that did not require treatment. Nineteen patients (43%) experienced grade 3 or grade 4 adverse events. Surgical complications included cerebral edema, healing abnormalities, cerebral spinal fluid leakage, meningitis, intracranial abscess, and hydrocephalus. Neurological adverse events included newly diagnosed seizures, alteration of mental status, and new neurological deficits. Medical complications were thromboembolic events (thrombosis, pulmonary embolism) and hematotoxicity. Combination of both treatment strategies, local chemotherapy with BCNU wafer and concomitant radiochemotherapy, appears attractive in aggressive multimodal treatment schedules and may utilize the sensitizing effect of TMZ and carmustine on MGMT and AGT on their respective drug resistance genes. Our data demonstrate that combination of local chemotherapy and concomitant radiochemotherapy carries a significant risk of toxicity that currently appears underestimated. Adverse events observed in this study appear similar to complication rates published in the phase III trials for BCNU wafer implantation followed by radiation therapy alone, but further add the toxicity of concomitant radiochemotherapy with systemic TMZ. Save use of a combined approach will require specific prevention strategies for multimodal treatments.

Multicolor 3D Printing of Complex Intracranial Tumors in Neurosurgery.

Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. The model can be used for planning and simulating critical steps of a surgical approach. Therefore, it is important that anatomical structures such as blood vessels inside a tumor can be printed to be colored not only on their surface, but throughout their whole volume. During simulation this allows for the removal of certain parts (e.g., with a high-speed drill) and revealing internally located structures of a different color. Thus, diagnostic information from various imaging modalities (e.g., CT, MRI) can be combined in a single compact and tangible object. However, preparation and printing of such a fully colored anatomical model remains a difficult task. Therefore, a step-by-step guide is provided, demonstrating the fusion of different cross-sectional imaging data sets, segmentation of anatomical structures, and creation of a virtual model. In a second step the virtual model is printed with volumetrically colored anatomical structures using a plaster-based color 3D binder jetting technique. This method allows highly accurate reproduction of patient-specific anatomy as shown in a series of 3D-printed petrous apex chondrosarcomas. Furthermore, the models created can be cut and drilled, revealing internal structures that allow for simulation of surgical procedures.

Image-Guided Transcranial Doppler Ultrasound for Monitoring Posthemorrhagic Vasospasms of Infratentorial Arteries: A Feasibility Study.

BACKGROUND: A considerable number of patients with subarachnoid hemorrhage (SAH) develop vasospasms of the infratentorial arteries. Transcranial Doppler sonography (TCD) is used to screen for vasospasm. In this study, we used a technical modification that combines TCD with an image guidance device that the operator can use to navigate to the ultrasonic window and to predefined intracranial vascular targets. Our aim was to analyze the feasibility, spatial precision, and spatial reproducibility of serial image-guided TCD of infratentorial and-for comparison-supratentorial arteries in the clinical setting of monitoring for vasospasm after SAH. METHODS: The study included 10 SAH patients, who each received 5 serial image-guided TCD examinations. Using computed tomography angiography data, trajectories to the infratentorial and supratentorial cerebral arteries were planned and loaded into an image guidance device tracking the Doppler probe. As a measure of spatial precision and spatial reproducibility, we analyzed the distances between the positions of preplanned vascular targets and optimal Doppler signals. RESULTS: The mean distance between preplanned and optimal target points was 4.8 ± 2.1 mm (first exam), indicating high spatial precision. The spatial precision decreased with increasing depth of the vascular target. In all patients, image-guided TCD detected all predefined supratentorial and infratentorial vascular segments. There were no significant changes in spatial precision in serial exams, indicating high reproducibility. CONCLUSIONS: Image-guided TCD is feasible for supratentorial and infratentorial arteries. It shows high spatial precision and reproducibility. This study provides a basis for future clinical studies on image-guided TCD for post-SAH vasospasm screening.

Automated Grading of Cerebral Vasospasm to Standardize Computed Tomography Angiography Examinations After Subarachnoid Hemorrhage.

Background: Computed tomography angiography (CTA) is frequently used with computed tomography perfusion imaging (CTP) to evaluate whether endovascular vasospasm treatment is indicated for subarachnoid hemorrhage patients with delayed cerebral ischemia. However, objective parameters for CTA evaluation are lacking. In this study, we used an automated, investigator-independent, digital method to detect vasospasm, and we evaluated whether the method could predict the need for subsequent endovascular vasospasm treatment. Methods: We retrospectively reviewed the charts and analyzed imaging data for 40 consecutive patients with subarachnoid hemorrhages. The cerebrovascular trees were digitally reconstructed from CTA data, and vessel volume and the length of the arteries of the circle of Willis and their peripheral branches were determined. Receiver operating characteristic curve analysis based on a comparison with digital subtraction angiographies was used to determine volumetric thresholds that indicated severe vasospasm for each vessel segment. Results: The automated threshold-based volumetric evaluation of CTA data was able to detect severe vasospasm with high sensitivity and negative predictive value for predicting cerebral hypoperfusion on CTP, although the specificity and positive predictive value were low. Combining the automated detection of vasospasm on CTA and cerebral hypoperfusion on CTP was superior to CTP or CTA alone in predicting endovascular vasospasm treatment within 24 h after the examination. Conclusions: This digital volumetric analysis of the cerebrovascular tree allowed the objective, investigator-independent detection and quantification of vasospasms. This method could be used to standardize diagnostics and the selection of subarachnoid hemorrhage patients with delayed cerebral ischemia for endovascular diagnostics and possible interventions.

Volumetric analysis of intracranial vessels: a novel tool for evaluation of cerebral vasospasm.

PURPOSE: Together with other diagnostic modalities, computed tomography angiography (CTA) is commonly used to indicate endovascular vasospasm treatment after subarachnoid hemorrhage (SAH), despite the fact that objective, user-independent parameters for evaluation of CTA are lacking. This exploratory study was designed to investigate whether quantification of vasospasm by automated volumetric analysis of the middle cerebral artery M1 segment from CTA data could be used as an objective parameter to indicate endovascular vasospasm treatment. METHODS: We retrospectively identified SAH patients who underwent transcranial Doppler sonography (TCD), CTA, and CT perfusion (CTP), with or without subsequent endovascular treatment. We determined vessel volume/vessel length of the M1 segments from CTA data and used receiver operating characteristic curve analysis to determine the optimal threshold of vessel volume to predict vasospasm requiring endovascular treatment. In addition, blinded investigators independently analyzed TCD, CTA, and CTP data. RESULTS: Of 45 CTA examinations with corresponding CTP and TCD examinations (24 SAH patients), nine indicated the need for endovascular vasospasm treatment during examination. In our patients, vessel volume < 5.8 µL/mm was moderately sensitive but fairly specific to detect vasospasm requiring endovascular treatment (sensitivity, 67%; specificity, 78%; negative predictive value (NPV), 89%; positive predictive value (PPV), 46%). For CTA, CTP, and TCD, we found NPVs of 96%, 92%, and 89%, PPVs of 40%, 35%, and 35%, sensitivities of 89%, 78%, and 67%, and specificities of 67%, 64%, and 69%, respectively. CONCLUSION: Vessel volumes could provide a new objective parameter for the interpretation of CTA data and could thereby improve multimodal assessment of vasospasm in SAH patients.