Adrian J. Maurer

Aggressive repeat surgery for focally recurrent primary glioblastoma: outcomes and theoretical framework.

OBJECT The relative benefit of repeat surgery for recurrent glioblastoma is unclear, in part due to the very heterogeneous nature of the patient population and the effect of clinician philosophy on the duration and aggressiveness of treatment. The authors sought to investigate the role of time to last recurrence on patient outcomes following aggressive repeat surgery for recurrent glioblastoma. METHODS The authors present outcomes in 104 patients undergoing repeat surgery for focally recurrent glioblastoma with at least 95% resection and adjuvant treatment at most recent prior surgery. In addition to common variables, they provide data regarding the period of progression-free survival (PFS) following an aggressive lesionectomy for focally recurrent primary glioblastoma (T2) and the time the tumor took to recur since the previous surgery (T1). They term the ratio T1/T2 the relative aggressivity index (RAI). RESULTS The median PFS was 7.8 months, 6.0 months, and 4.8 months following the second, third, and fourth-sixth craniotomies, respectively. Importantly, there was a wide range of outcomes, with time to postoperative recurrence ranging from 1 to 24 months in this group. Analysis showed no meaningful relationship between T1 and T2, meaning that previous PFS is entirely unable to predict the PFS that another surgery will provide the patient. CONCLUSIONS Repeat surgery for glioblastoma is beneficial in many cases, however this is hard to predict preoperatively. Often, surgery can provide the patient with a good period of disease freedom, but this is variable and in general it is not possible to reliably predict who these patients are.

Retrievable inferior vena cava filters in trauma patients: factors that influence removal rate and an argument for institutional protocols.

BACKGROUND Trauma patients at risk for pulmonary embolism, but with contraindications for anticoagulation therapy, often have retrievable inferior vena cava filters (RIVCF) placed. This study evaluated factors associated with the recovery rate of the device (RIVCFs) with the goal of developing an institutional protocol to ensure timely removal. METHODS This was a case-control study of 88 trauma patients who underwent RIVCF placement at a level 1 trauma center between 2006 and 2010. RESULTS The overall retrieval rate was 58%, declining from 89% in 2006 to 50% in 2009. Factors independently associated with filter nonretrieval included increasing age, increase in number of providers, comorbidity, hospital discharge from the intensive care unit, and discharge to a long-term acute care facility or skilled nursing facility. In 2010, a protocol was implemented and the retrieval rate increased to 73%. CONCLUSIONS In a large institution where a number of providers may be responsible for filter management, implementation of a protocol appears to improve retrieval rates.

Management of Petroclival Meningiomas: A Review of the Development of Current Therapy

The surgical management of petroclival meningioma remains challenging, due to the difficulty of accessing the region and the vital structures adjacent to the origin of these tumors. Petroclival meningiomas were originally considered largely unresectable. Until the 1970s, resection carried a 50% mortality rate, with very high rates of operative morbidity if attempted. However, in the past 40 years, advances in neuroimaging and approaches to the region were refined, and results from resection of petroclival meningiomas have become more acceptable. Today, the developments of a multitude of surgical approaches as well as innovations in neuroimaging and stereotactic radiotherapy have proved powerful options for multimodality management of these challenging tumors.

Minimally invasive treatment of multilevel spinal epidural abscess

The use of minimally invasive tubular retractor microsurgery for treatment of multilevel spinal epidural abscess is described. This technique was used in 3 cases, and excellent results were achieved. The authors conclude that multilevel spinal epidural abscesses can be safely and effectively managed using microsurgery via a minimally invasive tubular retractor system.

Brainstem cavernous malformations resected via miniature craniotomies: Technique and approach selection

Brainstem cavernous malformations can cause devastating neurologic disability when they hemorrhage, which occurs at a higher rate in the brainstem than in other locations. Traditional access to these lesions requires a large craniotomy with extensive exposure and manipulation of vital structures. We present a case series of patients who underwent surgical resection of brainstem cavernous malformations using minimally invasive approaches at our institution from January 2012 to August 2014, all of whom had experienced at least one hemorrhage prior to presentation. Approach choice was determined by location of the cavernous malformation in relation to the brainstem surface. Resection occurred through our described standardized method. Postoperatively, there were three instances of transient neurologic symptoms, all of which resolved at time of last follow-up. All eight patients experienced neurologic improvement after surgery, with four patients showing no deficits at last follow-up. Approach selection rationale and technical nuances are presented on a case-by-case basis. With carefully planned keyhole approaches to cavernous malformations presenting to the brainstem surface, excellent results may be achieved without the necessity of larger conventional craniotomies. We believe the nuances presented may be of use to others in the surgical treatment of these lesions.

Dramatic response to temozolomide, irinotecan, and bevacizumab for recurrent medulloblastoma with widespread osseous metastases

There is little evidence to guide the choice of chemotherapeutic agents for osseous metastases in medulloblastoma. Recently, triple therapy with temozolomide, irinotecan, and bevacizumab has been reported to have efficacy in recurrent medulloblastoma, and this regimen alone and in combination with other agents has been tested in several early-phase clinical trials. Here we report a 20-year-old woman with multiply-relapsed medulloblastoma with numerous osseous metastases 8 years after original diagnosis who responded dramatically to temozolomide, irinotecan, and bevacizumab therapy. This case highlights the potential for this regimen in treating osseous metastases in medulloblastoma.

Endoscopic Endonasal Infrapetrous Transpterygoid Approach to the Petroclival Junction for Petrous Apex Chondrosarcoma: Technical Report

Chondrosarcomas of the skull base are rare tumors that present difficult management considerations due to the pathoanatomical relationships of the tumor to adjacent structures. We present the case of a 25-year-old female patient presenting with a chondrosarcoma of the right petrous apex extending inferiorly, medial to the cranial nerves. The tumor was resected via an endoscopic endonasal infrapetrous transpterygoid approach that achieved complete resection and an excellent long-term outcome with no complications. Technical nuances and potential pitfalls of the case are discussed in depth including measures to protect the carotid artery while performing the required drilling of the skull base to access the lesion.

Operative results of keyhole supracerebellar-infratentorial approach to the pineal region

The supracerebellar-infratentorial approach to the pineal region is typically accomplished with a craniotomy that extends to at least the rim of the foramen magnum. Minimally invasive techniques that limit the inferior extent of the craniotomy have been described for this approach but, to our knowledge, no operative results have been published demonstrating the feasibility and safety of such techniques. We present a series of patients who underwent surgical resection of pineal region lesions using the minimally invasive method at our institution. Clinical, radiologic, and operative data were prospectively collected on patients treated for lesions of the pineal region by the senior author from January 2012 to July 2014. Seven patients were identified. The sitting position was employed in each patient. Keyhole craniotomies were limited to a maximum diameter of 2.5 cm. Adequate working corridors were attained, and in no patient was resection limited by the exposure. No neurological or systemic complications were seen in the perioperative and early follow-up periods. In this feasibility study, we demonstrate that it is not necessary to extend a craniotomy inferiorly to the rim of the foramen magnum in order to gain access to the pineal region via relaxation of the cerebellum. The same surgical goals can be safely accomplished with a smaller craniotomy.

Clinical significance of changes in pB-C2 distance in patients with Chiari Type I malformations following posterior fossa decompression: a single-institution experience.

OBJECT The coexistence of Chiari malformation Type I (CM-I) and ventral brainstem compression (VBSC) has been well documented, but the change in VBSC after posterior fossa decompression (PFD) has undergone little investigation. In this study the authors evaluated VBSC in patients with CM-I and determined the change in VBSC after PFD, correlating changes in VBSC with clinical status and the need for further intervention. METHODS Patients who underwent PFD for CM-I by the senior author from November 2005 to January 2013 with complete radiological records were included in the analysis. The following data were obtained: objective measure of VBSC (pB-C2 distance); relationship of odontoid to Chamberlains, McGregors, McRaes, and Wackenheims lines; clival length; foramen magnum diameter; and basal angle. Statistical analyses were performed using paired t-tests and a mixed-effects ANOVA model. RESULTS Thirty-one patients were included in the analysis. The mean age of the cohort was 10.0 years. There was a small but statistically significant increase in pB-C2 postoperatively (0.5 mm, p < 0.0001, mixed-effects ANOVA). Eleven patients had postoperative pB-C2 values greater than 9 mm. The mean distance from the odontoid tip to Wackenheims line did not change after PFD, signifying postoperative occipitocervical stability. No patients underwent transoral odontoidectomy or occipitocervical fusion. No patients experienced clinical deterioration after PFD. CONCLUSIONS The increase in pB-C2 in patients undergoing PFD may occur as a result of releasing the posterior vector on the ventral dura, allowing it to relax posteriorly. This increase appears to be well-tolerated, and a postoperative pB-C2 measurement of more than 9 mm in light of stable craniocervical metrics and a nonworsened clinical examination does not warrant further intervention.

Keyhole Transsylvian Resection of Infiltrative Insular Gliomas: Technique and Anatomic Results.

AIM Insular gliomas have traditionally been approached through variations of large frontotemporal craniotomies exposing much of the Sylvian fissure. Due to the importance of many structures exposed by such an approach, a less-invasive approach to these lesions is a viable alternative for resection. We present the technique and results of our keyhole transsylvian approach to remove infiltrating insular tumors. MATERIAL AND METHODS A small linear incision and keyhole craniotomy is planned under image guidance to open a transsylvian window. Using a combination of the microscope and endoscope, we remove the insula circumferentially outward. We present our results of 20 patients with gliomas confined to the insula evaluated with volumetric imaging analysis. RESULTS There were 12 right-sided and 8 left-sided tumors. The median skin-to-skin operative time was 215 minutes. 15/20 patients were discharged from the hospital on or before post-operative day 3, with 5 of those going home the day after surgery. Greater than 90% of the tumor was removed in 18 of 20 cases, with an additional case achieving 89.5% resection. In no case was the residual tumor volume greater than 3 cc. Permanent weakness occurred in 2 patients (10%). Despite a significant number of left-sided tumors, temporary dysphasia occurred in only 1 patient (12.5%), which resolved by first follow up. CONCLUSION Localized insular gliomas can be effectively removed through a minimally invasive approach without increasing the risk of neurological morbidity. This minimizes manipulation of uninvolved, potentially eloquent cortices, and minimizes damage to the overlying soft tissue.