Memory clip for intracranial aneurysm surgery Technical note
TAKASH! IWABUCHI,M.D., SHIGEHARUSUZUKI, M.D., KUNIHIKO EBINA, M.D., AND TOSHIO HONMA, D.Sc. Department of Neurosurgery, Hirosaki University School of Medicine, Hirosaki, Japan w, The authors have devised a malleable V-shaped removable clip with mechanical memory effect or shape memory. This clip is easily removed by heating part of it to 79~ to 107~ causing the closed clip to return to its original V shape. KEYWORDS memory clip
9 Nitinol 9 surgery
9 aneurysm
9
CLIP for use in intracranial aneurysm "mechanical memory effect, shape memory, surgery should not only be nontoxic, or m e m o r y . ' " small, light, effective, reliable, and This clip has been successfully used in easy to handle, but also removable, a-a,5-12 animal experiments and in a series of clinical Recently we have devised a malleable, V- cases. An example of the value of the clip is shaped, removable clip made of Nitinol, an shown in Fig. 3. This patient, a 43-year-old alloy endowed with mechanical memory effect.' The clip is hand made at a temperature of 510 ~ to 593~ it is 0.4 • 0.7 mm in cross section, and 9 mm in length along the side of the V shape (Fig. 1). A
Technique
This clip can be applied at room temperature on a small artery or a narrow neck of an aneurysm using a slim clip applier. If removal is necessary, a part of the clip is heated to 79 ~ to 107~ by a sterilized smalltipped electric heater (Fig. 2); at this temperature range the clip returns to its original g shape; this process is called
J. Neurosurg. / Volume 42 /June, 1975
Ft~. 1. The clip applier and the hand-made memory clip. 1 = tips of the clip applier; 2 = front view of the open clip; 3 = front view of the closed clip; 4 = side view of the clip. 733
T. Iwabuchi, S. Suzuki, K. Ebina and T. Honma
FIG. 2. Diagram of the small-tipped electric heater. A = screw-in tip of nichrome wire heater; B = grip with flexible portion; C = on-off switch; D = plug-and-jack connecting cord; E = power source, 3-V battery. In surgical use, this is sterilized with ethylene oxide gas. Note: This model is a prototype, made by hand from a commercially available lighter for gas heaters. man, had an anterior communicating artery aneurysm. A right-sided unilateral craniotomy revealed the aneurysm, with a fragile thin-walled bleb threatening premature rupture, directly upon the optic chiasm and touching the A1 portion of the contralateral anterior cerebral artery. A small, light, aneurysm clip was required to avoid pressure from the weight of the clip on the optic chiasm. On the first attempt the opposite A1 portion was clipped together with the aneurysmal neck. The clip was removed and successfully placed on the second attempt.
The patient suffered no undesirable effects and was doing well 10 months postoperatively.
Comment Nitinol, m o r e precisely called "55 Nitinol," is a stainless nickel-titanium alloy that was developed at the U.S. Naval Ordnance L a b o r a t o r y . 4 In our animal experiments, clips in place for more than 2 months showed no unfavorable change of the brain or other i m p o r t a n t tissue either morphologically or neurophysiologically. The Nitinol presently available seems to be less malleable and less resistant to arterial tension than traditional silver clips, and we are at present working on a more suitable alloy for neurosurgical use.
References
FIG. 3. An anterior communicating aneurysm treated with a hand-made memory clip of Nitinol. At the first attempt the contralateral Ax portion was clipped together with the aneurysm neck. The clip was removed and the aneurysm neck was successfully clipped on the second attempt. I = left optic nerve; 2 = right optic nerve; 3 = the optic chiasm; 4 = anterior communicating artery aneurysm; 5 = thin-walled bleb; 6 = opposite A2 portion; 7 = right A1 portion; 8 = memory clip snugly applied on the aneurysm neck. 734
1. Alexander E Jr, Adams JE, Davis CH Jr: Complications in the use of temporary intracranial arterial clip. J Neurosurg 20:810-811, 1963 2. Black SPW, German W,I: A clamp for temporarily occluding small blood vessels. J Neurosurg 11:514-515, 1954 3. Heifetz MD: A new intracranial aneurysm clip. J Neurosurg 30: 753, 1969 4. ,iackson CM, Wagner H J, Wasilewski R.I: 55-
Nitinol. The Alloy with a Memory. Its Physical Metallurgy, Properties, and Applications. A Report. NASA SP 5110. NASA, 1972
J. Neurosurg. / Volume 42 / June, 1975
Memory clip for aneurysm surgery 5. Lougheed WM, Khodadad G: A new clip for surgery of intracranial and small blood vessels. J Neurosurg 22:397-398, 1965 6. Mayfield FH, Kees G Jr: A brief history of the development of the Mayfield clip. Technical note. J Neurosurg 35:97-100, 1971 7. Samuels PB, Roedling H, Katz R, et al: A new hemostatic clip. 2-year review of 1007 cases. Ann Surg 163:427-431, 1966 8. Scoville WB: Miniature torsion bar spring aneurysm clip. J Neurosurg 25:97, 1966 9. Sundt TM Jr: Clip-gra• for aneurysm and small vessel surgery. Part 4: Relative application to various aneurysms and repair of anterior communicating aneurysms using right-angle clip holder. Technical note. J Neurosurg 37:753-758, 1972 10. Sundt TM Jr, Nofzinger JD: Clip-grafts for aneurysm and small vessel surgery. Part 1: Repair of segmental defects with clip-grafts; laboratory studies and clinical correlations.
J. Neurosurg. / Volume 42 / June, 1975
Part 2: Clinical application of clip-grafts to aneurysms: technical considerations. J Neurosurg 27:477-489, 1967 I I. Wilkins RH: Neurosurgical classics XXI. J Neurosurg 21:713-723, 1964 12. Wise BL, Green ED: A new type of tantalum clip for occluding cerebral blood vessels. J Neurosurg 11:633-634, 1954
This paper was presented in part at the meeting of the Hirosaki Medical Society, Hirosaki, Japan, December 20, 1973. Address for Dr. Honma: The Research Institute of Mineral Dressing and Metallurgy, Tohoku University, Sendai, Japan. Address reprint requests to: Takashi Iwabuchi, M.D., Department of Neurosurgery, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki-shi, 036 Japan.
735
TAKASH! IWABUCHI,M.D., SHIGEHARUSUZUKI, M.D., KUNIHIKO EBINA, M.D., AND TOSHIO HONMA, D.Sc. Department of Neurosurgery, Hirosaki University School of Medicine, Hirosaki, Japan w, The authors have devised a malleable V-shaped removable clip with mechanical memory effect or shape memory. This clip is easily removed by heating part of it to 79~ to 107~ causing the closed clip to return to its original V shape. KEYWORDS memory clip
9 Nitinol 9 surgery
9 aneurysm
9
CLIP for use in intracranial aneurysm "mechanical memory effect, shape memory, surgery should not only be nontoxic, or m e m o r y . ' " small, light, effective, reliable, and This clip has been successfully used in easy to handle, but also removable, a-a,5-12 animal experiments and in a series of clinical Recently we have devised a malleable, V- cases. An example of the value of the clip is shaped, removable clip made of Nitinol, an shown in Fig. 3. This patient, a 43-year-old alloy endowed with mechanical memory effect.' The clip is hand made at a temperature of 510 ~ to 593~ it is 0.4 • 0.7 mm in cross section, and 9 mm in length along the side of the V shape (Fig. 1). A
Technique
This clip can be applied at room temperature on a small artery or a narrow neck of an aneurysm using a slim clip applier. If removal is necessary, a part of the clip is heated to 79 ~ to 107~ by a sterilized smalltipped electric heater (Fig. 2); at this temperature range the clip returns to its original g shape; this process is called
J. Neurosurg. / Volume 42 /June, 1975
Ft~. 1. The clip applier and the hand-made memory clip. 1 = tips of the clip applier; 2 = front view of the open clip; 3 = front view of the closed clip; 4 = side view of the clip. 733
T. Iwabuchi, S. Suzuki, K. Ebina and T. Honma
FIG. 2. Diagram of the small-tipped electric heater. A = screw-in tip of nichrome wire heater; B = grip with flexible portion; C = on-off switch; D = plug-and-jack connecting cord; E = power source, 3-V battery. In surgical use, this is sterilized with ethylene oxide gas. Note: This model is a prototype, made by hand from a commercially available lighter for gas heaters. man, had an anterior communicating artery aneurysm. A right-sided unilateral craniotomy revealed the aneurysm, with a fragile thin-walled bleb threatening premature rupture, directly upon the optic chiasm and touching the A1 portion of the contralateral anterior cerebral artery. A small, light, aneurysm clip was required to avoid pressure from the weight of the clip on the optic chiasm. On the first attempt the opposite A1 portion was clipped together with the aneurysmal neck. The clip was removed and successfully placed on the second attempt.
The patient suffered no undesirable effects and was doing well 10 months postoperatively.
Comment Nitinol, m o r e precisely called "55 Nitinol," is a stainless nickel-titanium alloy that was developed at the U.S. Naval Ordnance L a b o r a t o r y . 4 In our animal experiments, clips in place for more than 2 months showed no unfavorable change of the brain or other i m p o r t a n t tissue either morphologically or neurophysiologically. The Nitinol presently available seems to be less malleable and less resistant to arterial tension than traditional silver clips, and we are at present working on a more suitable alloy for neurosurgical use.
References
FIG. 3. An anterior communicating aneurysm treated with a hand-made memory clip of Nitinol. At the first attempt the contralateral Ax portion was clipped together with the aneurysm neck. The clip was removed and the aneurysm neck was successfully clipped on the second attempt. I = left optic nerve; 2 = right optic nerve; 3 = the optic chiasm; 4 = anterior communicating artery aneurysm; 5 = thin-walled bleb; 6 = opposite A2 portion; 7 = right A1 portion; 8 = memory clip snugly applied on the aneurysm neck. 734
1. Alexander E Jr, Adams JE, Davis CH Jr: Complications in the use of temporary intracranial arterial clip. J Neurosurg 20:810-811, 1963 2. Black SPW, German W,I: A clamp for temporarily occluding small blood vessels. J Neurosurg 11:514-515, 1954 3. Heifetz MD: A new intracranial aneurysm clip. J Neurosurg 30: 753, 1969 4. ,iackson CM, Wagner H J, Wasilewski R.I: 55-
Nitinol. The Alloy with a Memory. Its Physical Metallurgy, Properties, and Applications. A Report. NASA SP 5110. NASA, 1972
J. Neurosurg. / Volume 42 / June, 1975
Memory clip for aneurysm surgery 5. Lougheed WM, Khodadad G: A new clip for surgery of intracranial and small blood vessels. J Neurosurg 22:397-398, 1965 6. Mayfield FH, Kees G Jr: A brief history of the development of the Mayfield clip. Technical note. J Neurosurg 35:97-100, 1971 7. Samuels PB, Roedling H, Katz R, et al: A new hemostatic clip. 2-year review of 1007 cases. Ann Surg 163:427-431, 1966 8. Scoville WB: Miniature torsion bar spring aneurysm clip. J Neurosurg 25:97, 1966 9. Sundt TM Jr: Clip-gra• for aneurysm and small vessel surgery. Part 4: Relative application to various aneurysms and repair of anterior communicating aneurysms using right-angle clip holder. Technical note. J Neurosurg 37:753-758, 1972 10. Sundt TM Jr, Nofzinger JD: Clip-grafts for aneurysm and small vessel surgery. Part 1: Repair of segmental defects with clip-grafts; laboratory studies and clinical correlations.
J. Neurosurg. / Volume 42 / June, 1975
Part 2: Clinical application of clip-grafts to aneurysms: technical considerations. J Neurosurg 27:477-489, 1967 I I. Wilkins RH: Neurosurgical classics XXI. J Neurosurg 21:713-723, 1964 12. Wise BL, Green ED: A new type of tantalum clip for occluding cerebral blood vessels. J Neurosurg 11:633-634, 1954
This paper was presented in part at the meeting of the Hirosaki Medical Society, Hirosaki, Japan, December 20, 1973. Address for Dr. Honma: The Research Institute of Mineral Dressing and Metallurgy, Tohoku University, Sendai, Japan. Address reprint requests to: Takashi Iwabuchi, M.D., Department of Neurosurgery, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki-shi, 036 Japan.
735
