Malte Ottenhausen

Functional preoperative and intraoperative mapping and monitoring: increasing safety and efficacy in glioma surgery

Greater extent of resection (EOR) of low-grade gliomas is associated with improved survival. Proximity to eloquent cortical regions often limits resectability and elevates the risk of surgery-related deficits. Therefore, functional localization of eloquent cortex or subcortical fiber tracts can enhance the EOR and functional outcome. Imaging techniques such as functional MRI and diffusion tensor imaging fiber tracking, and neurophysiological methods like navigated transcranial magnetic stimulation and magnetoencephalography, make it possible to identify eloquent areas prior to resective surgery and to tailor indication and surgical approach but also to assess the surgical risk. Intraoperative monitoring with direct cortical stimulation and subcortical stimulation enables surgeons to preserve essential functional tissue during surgery. Through tailored pre- and intraoperative mapping and monitoring the EOR can be maximized, with reduced rates of surgery-related deficits.

Endoscopic Endonasal Resection of Suprasellar Meningiomas: The Importance of Case Selection and Experience in Determining Extent of Resection, Visual Improvement, and Complications

OBJECTIVE Suprasellar meningiomas have been resected via various open cranial approaches. During the past 2 decades, the endoscopic endonasal approach has been shown to be an option in selected patients. We wished to examine the learning curve for parameters such as extent of resection, visual outcome, and complications. METHODS We retrospectively reviewed a consecutive series of patients in whom suprasellar meningiomas were resected via an endonasal endoscopic approach between 2005 and 2013 at our institution. After June 2008, our surgical technique matured. Using this time point, we divided our case series into 2 chronological groups, group 1 (n=8) and group 2 (n=12). This cut-off also was used to examine rates of gross total resection (GTR) and visual improvement. Case selection criteria in successful and unsuccessful cases were examined to determine important principals for case selection. RESULTS Mean patient age at surgery was 57.05 years (range, 31-81 years). Mean tumor volume was 11.98 cm3 (range, 0.43-28.93 cm3). Overall, GTR was achieved in 80%, and vision improved or normalized in 14 patients (82.4%) with no occurrence of postoperative visual deterioration. Rates of GTR increased from 62.5% (group 1) to 91.7% (group 2). Visual improvement increased from 75% (group 1) to 88.9% (group 2). Rates of cerebrospinal fluid leak were 25% in group 1 and 0% in group 2. Average follow-up was 51.5 month (range, 3-96 months). CONCLUSION Once the learning curve is overcome, surgeons performing endonasal endoscopic resection of suprasellar meningiomas can achieve high rates of GTR with low complication rates in well-selected cases.

Results and risk factors for recurrence following endoscopic endonasal transsphenoidal surgery for pituitary adenoma.

BACKGROUND Endoscopic endonasal (EE) transsphenoidal surgery is an important surgical approach to the treatment of sellar pathology, particularly for pituitary adenomas. Risk factors for the radiographic recurrence of pituitary adenomas resected using a purely endoscopic approach have not been established. This study investigates outcomes and identifies risk factors for recurrence following EE transsphenoidal surgery for pituitary adenoma. METHODS We performed a retrospective review of 64 patients with pituitary adenomas undergoing EE surgery by a single, right-handed surgeon preferentially operating through the right nares. Post-operative MRI studies were utilized to monitor for residual disease or disease recurrence. RESULTS Residual tumor was found in 31.2% of patients. Over a median follow-up period of 23.1 months (range 4-62.5), 4 (20%) of these patients showed recurrence. Two patients with inconclusive post-operative imaging had subsequent imaging consistent with recurrence, making the total recurrence in our series 9.4%. While no statistically significant effects of gender, age or history of previous treatment were seen, amenorrhea on presentation and maximum tumor diameter >10 mm were significant risk factors for radiographic recurrence (p = 0.044 and 0.005, respectively). No predominant side of residual tissue was identified in these tumors operated through the right nares. CONCLUSIONS Only 20% of patients with residual tumor developed recurrent disease over a median follow up of 23.1 months. This recurrence rate may be an important consideration in cases where gross total resection is not feasible. Preferentially operating from the right does not seem to influence the location of residual tumor.

Expanding the borders: the evolution of neurosurgical approaches.

In this article the authors discuss the development of neurosurgical approaches and the advances in science and technology that influenced this development throughout history. They provide a broad overview of this interesting topic from the first attempts of trephination by ancient cultures to the work of the pioneers of neurosurgery and the introduction of microsurgery.

Industry progress report on neuro-oncology: Biotech update 2013

For the second time, The Brain Tumor Center of the Weill Cornell Brain and Spine Center, in collaboration with Voices Against Brain Cancer, hosted The Brain Tumor Biotech Summit in New York City in June 2013. After a very successful first summit in 2012, this innovative event has established a platform for intensive networking between neuro-oncologists, neurosurgeons, neuroscientists, members of the biotechnology and pharmaceutical communities, members of the financial community and leaders of non-profit organizations. This year’s summit highlighted dendritic cell vaccines, novel antibody, heat shock protein and targeted therapies as well as exosome technologies, MRI-guided therapies and other novel drug delivery tools. This report presents a short overview of the current progress in brain tumor research and therapy as presented at the 2013 Brain Tumor Biotech Summit.

Vincent du Vigneaud: following the sulfur trail to the discovery of the hormones of the posterior pituitary gland at Cornell Medical College

In 1955, Vincent du Vigneaud (1901-1978), the chairman of the Department of Biochemistry at Cornell University Medical College, was awarded the Nobel Prize for Chemistry for his research on insulin and for the first synthesis of the posterior pituitary hormones-oxytocin and vasopressin. His tremendous contribution to organic chemistry, which began as an interest in sulfur-containing compounds, paved the way for a better understanding of the pituitary gland and for the development of diagnostic and therapeutic tools for diseases of the pituitary. His seminal research continues to impact neurologists, endocrinologists, and neurosurgeons, and enables them to treat patients who had no alternatives prior to du Vigneauds breakthroughs in peptide structure and synthesis. The ability of neurosurgeons to aggressively operate on parasellar pathology was directly impacted and related to the ability to replace these hormones after surgery. The authors review the life and career of Vincent du Vigneaud, his groundbreaking discoveries, and his legacy of the understanding and treatment of the pituitary gland in health and disease.

Decision-making algorithm for minimally invasive approaches to anterior skull base meningiomas

OBJECTIVE Anterior skull base meningiomas are benign lesions that cause neurological symptoms through mass effect on adjacent neurovascular structures. While traditional transcranial approaches have proven to be effective at removing these tumors, minimally invasive approaches that involve using an endoscope offer the possibility of reducing brain and nerve retraction, minimizing incision size, and speeding patient recovery; however, appropriate case selection and results in large series are lacking. METHODS The authors developed an algorithm for selecting a supraorbital keyhole minicraniotomy (SKM) for olfactory groove meningiomas or an expanded endoscopic endonasal approach (EEA) for tuberculum sella (TS) or planum sphenoidale (PS) meningiomas based on the presence or absence of olfaction and the anatomical extent of the tumor. Where neither approach is appropriate, a standard transcranial approach is utilized. The authors describe rates of gross-total resection (GTR), olfactory outcomes, and visual outcomes, as well as complications, for 7 subgroups of patients. Exceptions to the algorithm are also discussed. RESULTS The series of 57 patients harbored 57 anterior skull base meningiomas; the mean tumor volume was 14.7 ± 15.4 cm3 (range 2.2-66.1 cm3), and the mean follow-up duration was 42.2 ± 37.1 months (range 2-144 months). Of 19 patients with olfactory groove meningiomas, 10 had preserved olfaction and underwent SKM, and preservation of olfaction in was seen in 60%. Of 9 patients who presented without olfaction, 8 had cribriform plate invasion and underwent combined SKM and EEA (n = 3), bifrontal craniotomy (n = 3), or EEA (n = 2), and one patient without both olfaction and cribriform plate invasion underwent SKM. GTR was achieved in 94.7%. Of 38 TS/PS meningiomas, 36 of the lesions were treated according to the algorithm. Of these 36 meningiomas, 30 were treated by EEA and 6 by craniotomy. GTR was achieved in 97.2%, with no visual deterioration and one CSF leak that resolved by placement of a lumbar drain. Two patients with tumors that, based on the algorithm, were not amenable to an EEA underwent EEA nonetheless: one had GTR and the other had a residual tumor that was followed and removed via craniotomy 9 years later. CONCLUSIONS Utilizing a simple algorithm aimed at preserving olfaction and vision and based on maximizing use of minimally invasive approaches and selective use of transcranial approaches, the authors found that excellent outcomes can be achieved for anterior skull base meningiomas.

Clinical Use of Navigation in Lateral Skull Base Surgery: Results of a Multispecialty National Survey among Skull Base Surgeons in Germany

Abstract Objective To analyze the current clinical use of navigation at the lateral skull base among skull base surgeons in Germany. Methods A web‐based questionnaire was provided to surgeons being head of the department and member of one of the following scientific societies: German Society of Head and Neck Surgery, Maxillo‐Facial Surgery, Neurosurgery, and German Skull Base Society. Replies were recorded anonymously. The questionnaire included the estimated case load per year and percent of surgery performed with navigation (middle and posterior fossa), type of navigation, estimates of intraoperative inaccuracy, and reasons for not using navigation. Results Eighty nine out of 99 replies met requirements for final analysis. Overall, 37% of skull base surgeons use navigation on a regular basis (15% use no navigation). Optical tracking is more frequently used than magnetic tracking (71 vs 19). At the middle fossa, ENT surgeons split into routine users (n = 10/36) and rare users (n = 16/36), the latter stating navigation inaccuracy as a major reason for neglecting navigation. Neurosurgeons use navigation at the middle fossa significantly more often and criticize navigation inaccuracy less. At the posterior fossa, navigation is used less frequently by both ENT and neurosurgeons with similar rates of estimated inaccuracy. Conclusions A moderate use of navigation at the lateral skull base was demonstrated. Insufficient accuracy causes ENT surgeons to frequently omit navigation at the middle fossa (not neurosurgeons) and posterior fossa (also neurosurgeons). Higher intraoperative navigation accuracy is needed to enhance the use of navigation at the lateral skull base.

Intradural spinal tumors in adults—update on management and outcome

Among spinal tumors that occur intradurally, meningiomas, nerve sheath tumors, ependymomas, and astrocytomas are the most common. While a spinal MRI is the state of the art to diagnose intradural spinal tumors, in some cases CT scans, angiography, CSF analyses, and neurophysiological examination can be valuable. The management of these lesions depends not only on the histopathological diagnosis but also on the clinical presentation and the anatomical location, allowing either radical resection as with most extramedullary lesions or less invasive strategies as with intramedullary lesions. Although intramedullary lesions are rare and sometimes difficult to manage, well-planned treatment can achieve excellent outcome without treatment-related deficits. Technical advances in imaging, neuromonitoring, minimally invasive approaches, and radiotherapy have improved the outcome of intradural spinal tumors. However, the outcome in malignant intramedullary tumors remains poor. While surgery is the mainstay treatment for many of these lesions, radiation and chemotherapy are of growing importance in recurrent and multilocular disease. We reviewed the literature on this topic to provide an overview of spinal cord tumors, treatment strategies, and outcomes. Typical cases of extra- and intramedullary tumors are presented to illustrate management options and outcomes.

Predictors of postoperative motor function in rolandic meningiomas

OBJECTIVEResection of supratentorial meningiomas is generally considered a low-risk procedure, but tumors involving the rolandic cortex present a unique challenge. The rate of motor function deterioration associated with resecting such tumors is not well described in the literature. Thus, the authors sought to report the rates and predictors of postoperative motor deficit following the resection of rolandic meningiomas to assist with patient counseling and surgical decision-making.METHODSAn institutions pathology database was screened for meningiomas removed between 2000 and 2017, and patients with neuroradiological evidence of rolandic involvement were identified. Parameters screened as potential predictors included patient age, sex, preoperative motor severity, tumor location, tumor origin (falx vs convexity), histological grade, FLAIR signal (T2-weighted MRI), venous involvement (T1-weighted MRI with contrast), intratumoral hemorrhage, embolization, and degree of resection (Simpson grade). Variables of interest included preoperative weakness and postoperative motor decline (novel or worsened permanent deficit). The SPSS univariate and bivariate analysis functions were used, and statistical significance was determined with alpha < 0.05.RESULTSIn 89 patients who had undergone resection of convexity (80.9%) or parasagittal (19.1%) rolandic meningiomas, a postoperative motor decline occurred in 24.7%. Of 53 patients (59.6%) with preoperative motor deficits, 60.3% improved, 13.2% were unchanged, and 26.4% worsened following surgery. Among the 36 patients without preoperative deficits, 22.2% developed new weakness. Predictors of preoperative motor deficit included tumor size (41.6 vs 33.2 cm3, p = 0.040) and presence of FLAIR signal (69.8% vs 50.0%, p = 0.046). Predictors of postoperative motor decline were preoperative motor deficit (47.2% vs 22.2%, p = 0.017), minor (compared with severe) preoperative weakness (25.6% vs 21.4%, p < 0.001), and preoperative embolization (54.5% vs 20.5%, p = 0.014). Factors that trended toward significance included parafalcine tumor origin (41.2% vs 20.8% convexity, p = 0.08), significant venous involvement (44.4% vs 23.5% none, p = 0.09), and Simpson grade II+ (34.2% vs 17.6% grade I, p = 0.07).CONCLUSIONSResection of rolandic area meningiomas carries a high rate of postoperative morbidity and deserves special preoperative planning. Large tumor size, peritumoral edema, preoperative embolization, parafalcine origin, and venous involvement may further increase the risk. Alternative surgical strategies, such as aggressive internal debulking, may prevent motor decline in a subset of high-risk patients.