American Association of Neurological Surgeons, May 1-5, 2010
The 78th Annual Meeting of the American Association of Neurological Surgeons took place May 1 to 5 in Philadelphia and attracted more than 7,000 attendees from around the world. The conference focused on the latest research in neurosurgery, and was the first paperless medical meeting in North America conducted via the Apple iPod touch.
"The big news of this conference was that it was the first paperless conference in the history of medicine in the United States, as all registrants received an iPod touch to communicate with other attendees and obtain electronic maps, as well as find exhibitors, posters and abstracts, without even having to cut down one tree," said AANS vice-president, Mitchel S. Berger, M.D., of the University of California in San Francisco.
Key highlights included advances in minimally invasive approaches such as radiosurgery, cost-effective therapies for patients, and evidence-based studies focusing on prevalent neurosurgical disease states. In addition, presentations focused on surgical management of glioblastoma, use of combination approaches for malignant brain tumors, surgical and medical management of pituitary tumors, and the use of brain mapping technology to aid in preserving brain function during surgery.
Nader Sanai, M.D., of the University of California in San Francisco, presented a study showing that nearly complete surgical resection is not necessary to see improvement in outcomes in patients with newly-diagnosed glioblastomas, but greater extent of resection is linked to improvement in overall survival.
The researchers identified 500 consecutive, newly-diagnosed supratentorial glioblastoma patients who underwent resection followed by chemotherapy and radiation. The researchers demonstrated a significant survival advantage with as little as 78 percent extent of resection, and stepwise improvement in survival was apparent in the 95 to 100 percent range.
"In essence, what the study found was that, in patients diagnosed with glioblastoma, unlike what we previously thought -- that we needed to resect 98 percent of the tumor, 78 percent gave enough benefit in terms of overall survival to the patient," said Berger, a study co-author. "Based on the results of this study, a paradigm shift in thought is occurring, where we now know that we don't have to do an 'all or nothing' resection."
In another study, presented at the conference by John S. Yu, M.D., of Cedars-Sinai Medical Center in Los Angeles, researchers found that the use of intracranial chemotherapy and a vaccine approach provided improved outcomes in patients with malignant brain tumors.
In the phase I study, the researchers aimed to validate whether using intracranial chemotherapy with biodegradable carmustine wafer placement in combination with dendritic cell vaccination would generate a cytotoxic effect, while inducing immunosuppression. Of nine patients, for whom immunologic data were available, the researchers showed that 67 percent demonstrated at least a 1.5-fold increase in immune response, compared to 50 percent in previous dendritic cell vaccine trials. In addition, patients with the greatest immune response also experienced the longest survival times.
The study was funded by MGI Pharma (Eisai Co. Ltd.). Two authors disclosed financial ties to ImmunoCellular Therapeutics; some ImmunoCellular Therapeutics patents pending may have some relevance to concepts from the trial.
Jason P. Sheehan, M.D., of Brigham and Women's Hospital in Boston, presented a study on Gamma Knife radiosurgery. The researchers evaluated the efficacy and safety of the surgery in 418 patients with pituitary adenomas. They found tumor control in 90.3 percent of patients, with a higher radiation dose significantly affecting control of tumor growth. In addition, smaller adenoma size was associated with improved endocrine remission in those with secretory pituitary adenomas.
"Better outcomes following stereotactic radiosurgery were achieved in patients with a smaller tumor size of less than 1.6 cc and those in whom anti-secretory medications were temporarily withheld around the time of delivery of the stereotactic radiosurgery," Sheehan said. "The temporary cessation of anti-secretory medications likely made the tumor cells more sensitive to the beneficial effects of the radiosurgery."
Another study presented at the meeting focused on research by Muhammad Sami Walid, Ph.D., of the Medical Center of Central Georgia in Macon, and colleagues, who retrospectively evaluated 578 patients who underwent spine surgery to evaluate the cost associated with the presence of certain comorbidities.
In patients undergoing lumbar decompression and fusion, the researchers found that comorbidities had an additive effect on length of hospital stay and hospital costs. The average hospital cost in patients with diabetes mellitus/elevated HbA1c or hypothyroidism was higher than the average hospital cost in patients without one of these comorbidities ($54,228 versus $46,360). The cost was even higher in patients with both diabetes mellitus/elevated HbA1c and hypothyroidism ($61,221), increasing further in patients who also had depression ($68,203).
"Comorbidities, including obesity, diabetes and hypertension, ran the costs associated with spine surgery up substantially," said Joe S. Robinson Jr., M.D., of the Georgia Neurosurgical Institute in Macon, and co-author of the study. "Surgeons need to pay attention to the presence of comorbid conditions and get them under control, as they can substantially increase the costs of surgery."
Kai Miller, Ph.D., of the University of Washington in Seattle, presented a study in which the researchers evaluated the efficacy of broadband electrocorticography in brain mapping in 11 patients with epilepsy awaiting brain surgery.
With this technique, "we are potentially able to more rapidly establish margins around the tumor, so when we remove the tumor, we cut out as little [as possible of the] tissue surrounding the tumor that affects speech or movements," Miller said. "It will allow us to move easily and identify functional areas of the brain, aiding us in preserving function in patients with brain tumors."
AANS: Findings Shed Light on Surgical Treatment of Dementia
WEDNESDAY, May 5 (HealthDay News) -- Many patients with normal pressure hydrocephalus (NPH) experience clinical declines similar to those of Alzheimer's disease (AD) patients, and newly discovered cerebrospinal fluid (CSF) biomarkers may help better diagnose forms of early dementia, as well as better identify patients who may benefit from surgical implantation of a shunt, according to research presented at the annual meeting of the American Association of Neurological Surgeons, held from May 1 to 5 in Philadelphia.