Neurosurgical forum Letters
to t h e e d i t o r
Cerebeilocerebral Pathways To THE EDITOR: We wish to clarify the statement in our article (Bantli H, Bloedel JR, Tolbert D: Activation of neurons in the cerebellar nuclei and ascending reticular formation by stimulation of the cerebellar surface. J Neurosurg 45:539-554, November, 1976) on page 542, third paragraph, "range in human studies: 0 to 71 mA/sq cm." This statement should not infer that the ranges of stimulus parameters were given for the activation of mossy fibers in humans. The current measurements were only quoted to indicate that the amount of current used in this study were comparable to the output parameters of cerebellar stimulation systems when measured in saline. HEINRICHBANTLI,PH.D. Minneapolis, Minnesota
Approach to Circle of Willis To THE EDITOR: I have noted the correspondence published in the Letters to the Editor in the Journal (Volume 46, January, 1977, p. 130) regarding the right frontal lateral osteoplastic flap for anterior communicating aneurysms. This flap for the purpose stated originated with Walter Dandy. He used it even before the introduction of angiography. Dandy explored the entire anterior circle of Willis by way of the right lateral frontal osteoplastic flap in case of subarachnoid hemorrhage. LUDWIGG. KEMPE, M.D.
Charleston, South Carolina
Alteration of Suction Tip Pressure To THE EDITOR: In the last few years several companies have produced suction tips, especially the Frazier suction tips, with
J. Neurosurg. / Volume 46/April, 1977
thumb suction-relief openings too small to allow the operator to lessen the suction at the tip of the tube sufficiently well. I have altered the suction tips in our department to allow adequate relief of the suction at the end of the tip so that the operator can, with his finger off the suction relief hole, still acquire minimal suction for light fluid. This maneuver is especially important when using suction around aneurysms and delicate vessels, and when doing suction-coagulation in the base of a tumor. We have had some serious nearaccidents when delicate tissues of this sort were sucked up into the sucker and held. Such relief is even more important when a less experienced assistant is handling the suction. Many suction tips now have a suction relief hole of approximately 1/16 in. diameter, no matter what the diameter of the suction tube tip. I have redrilled the No. 2 or No. 7 French sucker to 5/64 in. diameter, the No. 3 or No. 9 French sucker to 3/32 in. diameter, and the No. 4 or No. 11 Erench sucker to 7/64 in. diameter. Once these holes are enlarged, the outer portion of the hole is touched lightly to the tip of a turning IA-inch bit to remove the burrs. If greater relief is required, and we have not found this necessary, the No. 2 or No. 7 French sucker can be drilled to 3/32 in., the No. 3 or No. 9 French size to 7/64 in., and the No. 4 or No. 11 French size to 1/8 in. My first choice drills for hole sizes are as follows: No. 2 or No. 7 French sucker 5/64 in. drill; No. 3 or No. 9 French sucker 3/32 in. drill; No. 4 or No. 11 French sucker - - 7/64 in. drill. After a suction tip has been drilled, the cavity will contain drilling oil and metal fragments. These must be carefully removed with detergent, high-pressure washing, and final cleansing with an ultrasonic cleaner. CHARLESP. BONDURANT,M.D. Oklahoma City, Oklahoma
559
to t h e e d i t o r
Cerebeilocerebral Pathways To THE EDITOR: We wish to clarify the statement in our article (Bantli H, Bloedel JR, Tolbert D: Activation of neurons in the cerebellar nuclei and ascending reticular formation by stimulation of the cerebellar surface. J Neurosurg 45:539-554, November, 1976) on page 542, third paragraph, "range in human studies: 0 to 71 mA/sq cm." This statement should not infer that the ranges of stimulus parameters were given for the activation of mossy fibers in humans. The current measurements were only quoted to indicate that the amount of current used in this study were comparable to the output parameters of cerebellar stimulation systems when measured in saline. HEINRICHBANTLI,PH.D. Minneapolis, Minnesota
Approach to Circle of Willis To THE EDITOR: I have noted the correspondence published in the Letters to the Editor in the Journal (Volume 46, January, 1977, p. 130) regarding the right frontal lateral osteoplastic flap for anterior communicating aneurysms. This flap for the purpose stated originated with Walter Dandy. He used it even before the introduction of angiography. Dandy explored the entire anterior circle of Willis by way of the right lateral frontal osteoplastic flap in case of subarachnoid hemorrhage. LUDWIGG. KEMPE, M.D.
Charleston, South Carolina
Alteration of Suction Tip Pressure To THE EDITOR: In the last few years several companies have produced suction tips, especially the Frazier suction tips, with
J. Neurosurg. / Volume 46/April, 1977
thumb suction-relief openings too small to allow the operator to lessen the suction at the tip of the tube sufficiently well. I have altered the suction tips in our department to allow adequate relief of the suction at the end of the tip so that the operator can, with his finger off the suction relief hole, still acquire minimal suction for light fluid. This maneuver is especially important when using suction around aneurysms and delicate vessels, and when doing suction-coagulation in the base of a tumor. We have had some serious nearaccidents when delicate tissues of this sort were sucked up into the sucker and held. Such relief is even more important when a less experienced assistant is handling the suction. Many suction tips now have a suction relief hole of approximately 1/16 in. diameter, no matter what the diameter of the suction tube tip. I have redrilled the No. 2 or No. 7 French sucker to 5/64 in. diameter, the No. 3 or No. 9 French sucker to 3/32 in. diameter, and the No. 4 or No. 11 Erench sucker to 7/64 in. diameter. Once these holes are enlarged, the outer portion of the hole is touched lightly to the tip of a turning IA-inch bit to remove the burrs. If greater relief is required, and we have not found this necessary, the No. 2 or No. 7 French sucker can be drilled to 3/32 in., the No. 3 or No. 9 French size to 7/64 in., and the No. 4 or No. 11 French size to 1/8 in. My first choice drills for hole sizes are as follows: No. 2 or No. 7 French sucker 5/64 in. drill; No. 3 or No. 9 French sucker 3/32 in. drill; No. 4 or No. 11 French sucker - - 7/64 in. drill. After a suction tip has been drilled, the cavity will contain drilling oil and metal fragments. These must be carefully removed with detergent, high-pressure washing, and final cleansing with an ultrasonic cleaner. CHARLESP. BONDURANT,M.D. Oklahoma City, Oklahoma
559
