Zachary Litvack

Indocyanine green fluorescence endoscopy for visual differentiation of pituitary tumor from surrounding structures

OBJECT As demonstrated by histological and neuroimaging studies, pituitary adenomas have a capillary vascular density that differs significantly from that of surrounding structures. The authors hypothesized that intraoperative indocyanine green (ICG) fluorescence endoscopy could be used to visually differentiate tumor from surrounding tissues, including normal pituitary gland and dura. METHODS After institutional review board approval, 16 patients undergoing endoscopic transsphenoidal surgery for benign pituitary lesions were prospectively enrolled in the study. A standard endoscopic endonasal approach to the sella was completed. Each patient then underwent endoscopic examination of the sellar dura and then the exposed pituitary adenoma after ICG bolus injection (12.5-25 mg). This examination was performed using a custom endoscope with a near-infrared light source and excitation wavelength filter. RESULTS The authors successfully recorded ICG fluorescence from sellar dura, pituitary, and surrounding structures in 12 of 16 patients enrolled. There were 3 technical failures of intraoperative ICG endoscopy, and 1 patient was excluded following discovery of a dye cross-allergy. A standard dose of 25 mg of ICG in 10 ml of aqueous solution optimized visualization of sellar region microvasculature within 45 seconds of peripheral bolus injection. Adenoma was less fluorescent than normal pituitary gland. Dural invasion by tumor was identifiable by a marked increase in fluorescence compared with native dura. The ICG endoscopic examination added 15-20 minutes of operative time under general anesthesia. There were no complications that resulted from use of ICG or the fluorescent light source. CONCLUSIONS Indocyanine green fluorescence endoscopy shows promise as an intraoperative modality to visually distinguish pituitary tumors from normal tissue and to visually identify areas of dural invasion, thereby facilitating complete tumor resection and minimizing injury to surrounding structures. These results support the continued development of fluorescence endoscopic resection techniques.

Dura splitting decompression for Chiari I malformation in pediatric patients: Clinical outcomes, healthcare costs, and resource utilization

BACKGROUND Dural splitting decompression may be an effective and safe treatment for Chiari I malformation. OBJECTIVE To compare clinical outcomes, complications, and resource utilization for patients undergoing Chiari I decompression with or without duraplasty. METHODS Between 2000 and 2009, the senior author performed 113 Chiari I decompression operations with dural splitting or duraplasty in children less than 18 years of age; 110 were included in a retrospective cohort analysis of safety, efficacy, and treatment cost. Patients without significant syringomyelia underwent dural splitting decompression, and patients with syringomyelia underwent duraplasty. RESULTS : Sixty-three patients without significant syringomyelia (57%) underwent dural splitting decompression. They were significantly younger than patients undergoing duraplasty (8.3 ± 4.9 years vs 10.4 ± 4.4 years; P < .05). Headaches improved or resolved in most patients in both groups (90.5% vs 93.6%; P = .59). Dysphagia, long tract signs, cranial nerve, and bulbar symptoms also improved similarly in both groups. Three duraplasty patients were treated medically for aseptic meningitis; one underwent reoperation for a symptomatic pseudomeningocele. No patient undergoing dural splitting decompression experienced a cerebrospinal fluid-related complication. Extradural decompression required less operative time than duraplasty (105.5 vs 168.9 minutes, P < .001), a shorter length of stay (2.4 vs 2.8 days, P = .011), and lower total cost for the primary hospitalization (

Magnetic resonance approaches to brain aging and Alzheimer disease-associated neuropathology.

26 837 vs

DURAL AUGMENTATION: PART I—EVALUATION OF COLLAGEN MATRIX ALLOGRAFTS FOR DURAL DEFECT AFTER CRANIOTOMY

29 862, P = .015). CONCLUSION In this retrospective cohort study, dural splitting decompression was equally effective, safer, and lower cost for treatment of Chiari I malformation without syringomyelia. A multicenter trial with groups balanced for the presence of syringomyelia is necessary to determine whether these results are generalizable.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Surgical Techniques and Technologies for the Management of Patients With Nonfunctioning Pituitary Adenomas

The noninvasive, nonradioactive, quantitative nature of magnetic resonance techniques has propelled them to the forefront of neuroscience and neuropsychiatric research. In particular, recent advances have confirmed their enormous potential in patients with Alzheimer disease (AD). Structural and functional magnetic resonance (MR) imaging have demonstrated significant correlation with clinical outcomes and underlying pathology and are used increasingly in the AD clinic. This review will highlight the role of high-resolution structural MR imaging and functional magnetic resonance imaging in the identification of atrophic and hemodynamic changes in AD and their potential as diagnostic biomarkers and surrogates of therapeutic response. Advanced MR techniques based on diffusion, perfusion, and neurochemical abnormalities in the aging brain will be presented briefly. These newer techniques continue to expand our understanding of neuropathology in the aging brain and are likely to play an important clinical role in the future.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Posttreatment Follow-up Evaluation of Patients With Nonfunctioning Pituitary Adenomas.

OBJECTIVEPrimary closure of the dura remains difficult in many neurosurgical cases. One option for dural grafting is the collagen sponge, which is available in multiple forms, namely, monolayer collagen and bilayer collagen. Our primary goal was to assess differences in the incidence of postoperative cerebrospinal fluid (CSF) leak, including fistula and pseudomeningocele, and postoperative infection between monolayer collagen and bilayer collagen grafts. METHODSA single-center retrospective analysis of 475 consecutive neurosurgical procedures was performed. Primary endpoints were CSF leak and infection, adjusting for the impact of additional nonautologous materials. Multivariate regression analysis was used to identify predictors of postoperative CSF leak and infection. RESULTSThe overall frequency of postoperative CSF leak was 6.7%. There was no significant difference in the incidence of CSF leak based on the type of collagen sponge (monolayer versus bilayer) used (5.5% versus 7.5%, respectively; P = 0.38). The overall frequency of postoperative infection was 4.2%. There was no significant difference in the incidence of infection between groups (4.9% versus 3.8%; P = 0.54). Bilayer sponges were associated with a significantly lower incidence of CSF leak than monolayer sponges (odds ratio, 0.09; 95% confidence interval, 0.01–0.73). CONCLUSIONBilayer collagen sponges are associated with a reduction in postoperative CSF leak, notably in posterior fossa surgery. The need for additional non-native materials is predictive of postoperative CSF leak, along with location and type of procedure. Intrinsic patient characteristics (e.g., age, diabetes, smoking) do not seem to affect the efficacy of collagen sponge dural grafts.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Primary Management of Patients With Nonfunctioning Pituitary Adenomas.

BACKGROUND Numerous technological adjuncts are used during transsphenoidal surgery for nonfunctioning pituitary adenomas (NFPAs), including endoscopy, neuronavigation, intraoperative magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) diversion, and dural closure techniques. OBJECTIVE To generate evidence-based guidelines for the use of NFPA surgical techniques and technologies. METHODS An extensive literature search spanning January 1, 1966, to October 1, 2014, was performed, and only articles pertaining to technological adjuncts for NFPA resection were included. The clinical assessment evidence-based classification was used to ascertain the class of evidence. RESULTS Fifty-six studies met the inclusion criteria, and evidence-based guidelines were formulated on the use of endoscopy, neuronavigation, intraoperative MRI, CSF diversion, and dural closure techniques. CONCLUSION Both endoscopic and microscopic transsphenoidal approaches are recommended for symptom relief in patients with NFPAs, with the extent of tumor resection improved by adequate bony exposure and endoscopic visualization. In select cases, combined transcranial and transsphenoidal approaches are recommended. Although intraoperative MRI can improve gross total resection, its use is associated with an increased false-positive rate and is thus not recommended. There is insufficient evidence to recommend the use of neuronavigation, CSF diversion, intrathecal injection, or specific dural closure techniques. The full guidelines document for this chapter can be located at https://www.cns.org/guidelines/guidelines-management-patients-non-functioning-pituitary-adenomas/Chapter_6. ABBREVIATIONS CSF, cerebrospinal fluidNFPA, nonfunctioning pituitary adenoma.

The future of practice science: challenges and opportunities for neurosurgery

BACKGROUND Nonfunctioning pituitary adenomas (NFPAs) are among the most common pituitary lesions and may present with hypopituitarism and/or hyperprolactinemia. OBJECTIVE To review the existing literature as it pertains to preoperative endocrine assessment in the workup for NFPAs. METHODS A systematic review methodology was utilized to identify and screen articles assessing the role and results of preoperative laboratory assessment in patients with NFPAs. The prevalence of individual pituitary hormonal axis deficiencies was reviewed. RESULTS Twenty-nine studies met inclusion criteria for analysis. No class I evidence was available, and all studies met criteria for class II evidence. Baseline serum laboratory assessment showed a prevalence of overall hypopituitarism in 37% to 85% of patients. The most common hormonal axis deficiency was growth hormone deficiency, prevalent in 61% to 100% of patients. The next most common deficit was hypogonadism, seen in 36% to 95% of patients. Adrenal insufficiency was diagnosed in 17% to 62% of patients. Finally, hypothyroidism was seen in 8% to 81% of patients. Hyperprolactinemia was seen in 25% to 65% of patients, with a mean level of 39 ng/mL and with a minority of patients exceeding a serum prolactin level of 200 ng/mL. No evidence supporting routine biomarker testing (eg, α-subunit or chromogranin A) or genetic testing in patients with sporadic NFPAs was available. CONCLUSION Despite a paucity of class I evidence, multiple retrospective studies have demonstrated a high prevalence of hypopituitarism in patients with NFPAs. Routine endocrine analysis of all anterior pituitary axes to assess for hypopituitarism is recommended, with prolactin and insulin-like growth factor 1 evaluation also valuable to assess for hypersecretion states that might not be clinically suspected. The full guidelines document for this chapter can be located at https://www.cns.org/guidelines/guidelines-management-patients-non-functioning-pituitary-adenomas/Chapter_3. ABBREVIATIONS GH, growth hormoneIGF-1, insulin-like growth factor 1NFPA, nonfunctioning pituitary adenoma.

Intracranial injectable tumor model: technical advancements.

BACKGROUND Nonfunctioning pituitary adenomas (NFPAs) are among the most common pituitary lesions and may present clinically with vision loss and hypopituitarism. OBJECTIVE To characterize the existing literature as it pertains to the initial management of NFPAs. METHODS A systematic literature review was conducted to identify and screen articles assessing primary treatment options (surgical, medical, radiation based, or observation) for NFPAs. Outcomes assessed included vision-, endocrine-, and headache-related symptoms, as well as tumor response to therapy. Twenty-five studies met inclusion criteria for analysis. RESULTS A considerable amount of class II evidence (14 studies) was identified supporting primary surgical intervention in patients with symptomatic NFPA macroadenomas, resulting in immediate tumor volume reduction in nearly all patients and a residual tumor rate of 10% to 36%. One prospective, observational cohort study and multiple retrospective studies showed improved visual function in 75% to 91% of surgically treated patients and improved hypopituitarism in 35% to 50% of patients. Limited class II evidence showed inconsistent benefits for observation alone (1 study), primary radiation-based treatment (3 studies), or primary medical treatment (8 studies) for improving vision, headaches, hypopituitarism, or tumor volume. One retrospective study implementing observation alone showed tumor progression in 50% of patients and a requirement for surgery in 21% of patients. Eight studies assessing primary medical therapy for NFPAs showed inconsistent tumor response rates using somatostatin analogs (12%-40% response rate), dopamine agonist therapy (0%-61% response rate), or combination therapy (60% response rate). Three studies reporting primary radiosurgery for NFPAs showed decreased tumor size in 38% to 60% of patients. CONCLUSION Multiple retrospective and some prospective studies have demonstrated consistent effectiveness of primary surgical resection of symptomatic NFPAs with acceptable morbidity rates. Limited and inconsistent reports are available for alternative treatment strategies, including radiation, medical treatment, and observation alone; these modalities may, however, play a valid role in patients who are not surgical candidates. Based on the available evidence, the authors recommend surgical resection as the preferred primary intervention for symptomatic NFPAs. The full guidelines document for this chapter can be located at https://www.cns.org/guidelines/guidelines-management-patients-non-functioning-pituitary-adenomas/Chapter_5. ABBREVIATION NFPA, nonfunctioning pituitary adenoma.

The utility of high-resolution intraoperative MRI in endoscopic transsphenoidal surgery for pituitary macroadenomas: early experience in the Advanced Multimodality Image Guided Operating suite

Outcomes-directed approaches to quality improvement have been adopted by diverse industries and are increasingly the focus of government-mandated reforms to health care education and delivery. The authors identify and review current reform initiatives originating from agencies regulating and funding graduate medical education and health care delivery. These reforms use outcomes-based methodologies and incorporate principles of lifelong learning and patient centeredness. Important new initiatives include the Accreditation Council for Graduate Medical Education Milestones; the pending adoption by the American Board of Neurological Surgery of new requirements for Maintenance of Certification that are in part outcomes based; initiation by health care systems and consortia of public reporting of patient outcomes data; institution by the Centers for Medicare & Medicaid Services of requirements for comparative effectiveness research and the physician quality reporting system; and linking of health care reimbursement in part to patient outcomes data and quality measures. Opportunities exist to coordinate and unify patient outcomes measurement throughout neurosurgical training and practice, enabling effective patient-centered improvements in care delivery as well as efficient compliance with regulatory mandates. Coordination will likely require the development of a new science of practice based in the daily clinical environment and utilizing clinical data registries. A generation of outcomes science and quality experts within neurosurgery should be trained to facilitate attainment of these goals.