Terasaki et al from Japan report on reoperations in a selected series of patients with glioblastoma multiforme. After repeated surgery, the authors gave their patients temozolomide chemotherapy. The authors fully acknowledge that their series is small and with possible biases. What is interesting is that the median survival was 15 months after reresection and chemotherapy. This survival is longer than that reported in other studies on reoperation for these tumors. Furthermore, the extent of resection for the second surgery did not seem to affect the outcome. For neurosurgeons, this is a frustrating disease to treat. In the 40 years in which I have worked on this disease in the laboratory and in the clinic, these are the most promising results I have seen for recurrent glioblastoma. If a relative of yours had this problem, what would you do?
Olivier et al from France have performed a complex but elegant study evaluating the use of photodynamic therapy on rats with implanted brain tumors. The authors gave the rats a chemical that is taken up by the brain tumor cells. This chemical sensitized the tumor cells to the laser beam. The laser beam was introduced through the cranial hole used to inject the tumor cells, and then, the tumor mass with the sensitizer chemical it had attracted was irradiated with the laser. The survival of the animals with the new treatment was longer than they found in animals with previously used sensitizers, by 75%. Read the abstract first and then the introduction. The discussion provides more detail if you want it. How would this treatment be if added to that of the previous article?
Kim et al from Japan use a bioabsorbable screw in anterior cervical fusions. It sounds like a good idea. In her comments, Nancy Epstein also believes that the bioabsorbable screw may be useful in this surgery.
Ammerman et al from the United States report on a simple technique for monitoring urinary bladder detrusor activity during cauda equina surgery. It is easy to use. It consists of placing a Foley catheter in the bladder without letting any urine escape and then adding a manometer to the end of the Foley. Then, during surgery with stimulation of the sacral roots, the bladder detrusor will contract, and the urine level in the manometer will increase. This article is brief, practical, and the comments are good.
The article by Ishikawa et al from Japan on the discovery of arteriovenous (AV) shunts in normal dura adjacent to the large venous sinuses is a nice article to read before the article that follows, by Kojima et al, on how these shunts may expand into AV fistulas. Ishikawa et al show that these shunts are present normally but must need some stimulus to increase in size.
Kojima et al from Japan have performed an interesting study in rats with clinical implications, coupled with the previous article by Ishikawa et al. After creating an internal carotid-to-jugular vein AV anastomosis and fistula in the neck plus some other maneuvers, the authors were able to produce intracranial venous hypertension. They found that vascular endothelial growth factor was produced in the sinus immediately and gradually decreased over time. They also measured the cerebral perfusion pressure in these animals. This is not an easy experiment to do, but what the experiment shows is that with venous hypertension, molecular signals are produced to cause proliferation of the endothelium of the sinus as a protective measure until other venous channels develop to produce alternate draining veins. As Macdonald says in his comments, this is the beginning of studies to understand the molecular factors involved in blood vessel changes in pathologic states. In this article, read the abstract and then the discussion. These 2 articles together provide a credible answer to the formation of dural AV fistulas.
Chen et al from Germany have written a detailed case report on the use of fiber tract imaging in brain tumors. The images are terrific and alone indicate the potential of this technology in approaching brain stem lesions.
Kashiwazaki et al from Japan used near-infrared transcutaneous spectroscopy to measure brain tissue oxygenation in a patient experiencing transient cerebral ischemia. This is an interesting report. Read the comments that are both critical and supportive. I asked Ron Widman of the Somanetics Corporation (Troy, MI), which makes a US-produced cerebral oximeter, to provide some comments and more background data on this technology. The authors do not state which oximeter device they used of those on the market. By the way, I am on the Board of Directors of Somanetics Corporation and have done research with cerebral oximeters.
Sönmez et al from Turkey were looking for a way to protect the spinal cord from ischemic injury. Erythropoietin (EPO), the drug used to boost red cell production, has been found to have a neuroprotective effect. It is not certain how this protection occurs, but the authors describe evidence that the EPO and ischemia stimulate the production of a protein in the nucleus of the neuron called cyclic adenosine monophosphate–responsive element-binding protein. When CREB is activated, it causes the production of a factor, brain-derived neurotrophic factor, which acts on neurons to promote their survival. This molecular cascade leading to cell death after ischemia can be stopped by giving EPO. The authors showed that compared with controls, in which they produced ischemic spinal cord injury by inflation of a balloon in the proximal aorta, the animals treated with EPO after balloon occlusion had only temporary neuronal damage. They also measured the signaling agent CREB in the spinal cords of the sacrificed animals and found that CREB was increased in the ischemic controls and even more so in the EPO-treated animals. EPO stimulated production of CREB and presumably led to the formation of brain-derived neurotrophic factor, which has a neuroprotective effect. The EPO-treated animals had less neurologic spinal cord injury. So, that is what this article is about. Many investigators are trying to find neuroprotective agents, and this is a good model in which to test them. The practical value in this article is in its use in preventing spinal cord injury in aortic aneurysm surgery. We recently had a similar clinical situation in which the vascular surgeons asked us to put in a lumbar drain before aortic aneurysm surgery to reduce the CSF pressure and to prevent spinal cord ischemia that followed the cross-clamping of the aorta. I was skeptical of this idea until I read the literature that indicated that a lumbar drain is helpful in increasing prevention of spinal cord injury. Read the abstract of this article with my remarks. Then, you can read the introduction and the discussion and understand better what they are saying. To me, this approach sounds promising.
Lönnrot et al from Finland have an excellent report on their experience with a rare tumor, desmoplastic infantile ganglioglioma. Because patients in a wide referral area come to major hospitals in Finland, the Finnish neurosurgeons have a concentrated experience with many neurologic diseases and also do an excellent scientific job in assessing their work. This report is worth reading not only for the information but also as an example of how to write an excellent article.
There are a number of interesting case reports to read. At the end, there is a historical article on the first xenograft (use of dog or goat skull bone) in a cranioplasty and the history of cranioplasty as a procedure. It is a very interesting article to read and provides for us a humility lesson of what others before us had to do to cure disease. In 500 years, what will those who follow us think of what we are doing now?
Cappabianca and Magro have written a short editorial stimulated by my editorial in a previous issue on leadership vs consensus.
I have written the first in a series of editorials on how physicians lost power. It will be followed in future issues by articles on what we have to do to get it back, worldwide.
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