2013年6月15日 星期六

雷射光束傷口縫合術

雷射光束傷口縫合術
      據國外媒體報道﹐科學家現成功測試了一種含有黃金納米棒的焊接材料﹐它可以被用來激光焊接患者的手術傷口﹐從而替代傳統的針線縫合技術。

  這種焊料包含著黃金納米棒顆粒﹐可形成在身體中移動的彈性封條。美國化學研究所的科學家現已在豬腸道上測試了這種縫合材料﹐認為它可以替代傳統的針線縫合技術。他們發現這種技術可產生“液密和彈性封條”﹐並且能夠縮短手術操作時間。此外﹐對比針線縫合傷口﹐這種最新技術可以減少疤痕。


  該技術被稱為“激光組織焊接(LTW)”﹐美國化學研究所的科學家希望能夠進一步改良激光組織焊接技術﹐產生更加結實的傷口縫合。考沙爾-雷格和同事決定使用一種叫做等離子納米材料的焊料﹐它包含著黃金納米棒。
 
傳統傷口縫合使用消毒的縫針﹐但有時該方法會導致傷口破裂和感染。目前﹐美國化學研究所的科學家最新研製一種傷口縫合技術﹐使用激光進行焊接傷口﹐可形成液密性較強的彈性封條

  焊料中包裹著黃金納米棒將更具有彈性﹐這意味著焊料可在身體中移動﹐從而降低了縫合開裂的可能性。科學家發現當這種材料作為光激活焊料對豬腸道切口進行激光焊接時﹐可以形成一種較結實的液密封條結構﹐並具有一定的彈性﹐它能夠避免有害細菌感染。

 “激光組織焊接”技術可改進手術治療時間﹐減少永久性疤痕的形成。目前科學家使用黃金納米棒作為焊接成分可形成較結實的傷口縫合

  雷格說﹕“總而言之﹐等離子納米材料帶給科學家們驚喜﹐可用於激光人體組織修復手術。”研究人員計劃進一步調查動物腸道傷口的縫合情況﹐從而確定是否在某些狀態下替代傳統針線縫合傷口。

以色列雷射光束傷口縫合術
http://english.tau.ac.il/


國外媒體報導 近日,以色列科學家開發出一種鐳射焊接術來縫合病人手術後的傷口,這樣可使皮膚和內部組織癒合得更快。不久的將來,醫生為病人做完手術後,不是用針線為他們縫合傷口,而是用鐳射焊接術使傷口縫合。以色列特拉維夫大學亞伯拉罕-卡茨爾教授領導的研究小組負責這一研究。 


早在幾十年前,就有人提議採用鐳射手術進行傷口癒合,但是由於產生的溫度太高造成皮膚或人體組織燒傷而被遺棄。新技術採用了智慧鐳射,在工作的時候可以調整自己的溫度。從而能夠避免這一問題的出現。研究人員使用以色列歐姆雷克斯生物技術公司生產的一種特殊白蛋白作為生物黏合劑,把這種特殊生物膠塗在切口的兩側。用鐳射把它加熱到適當的溫度,使膠濃縮並產生硬殼,從而能夠保護傷口,使其能夠更快癒合,又能阻止細菌感染。

醫務救護人員可以把這種新的技術應用到事故現場,使救護病人的傷口更快更安全的癒合。 新方法與傳統的縫合術相比能減少疤痕,並能更好地保護傷口,使傷口免受感染。研究人員認為將一方法將在整形外科和戰場上發揮用武之地。在整形外科方面,新技術可以為全世界的愛美人士帶來福音;未來戰場上,士兵可以使用雷射器進行相互救治,從而大大減少戰爭傷亡,提高戰鬥能力。 

卡茨爾教授稱,針線逢合術已經存在了1000多年,是一項歷史悠久的外科手術縫合方法。它是目前治療外傷、腫瘤、感染、畸形等眾多疾病的重要方法,有些甚至是唯一的方法。而止血、縫合是手術的基本技術。止血的目的就是減少術中、術後的出血並防止形成血腫。血腫容易引起繼發感染並妨礙纖維母細胞移動和毛細血管再生,影響傷口的癒合。縫合是使傷口的間隙消失有助術後傷口的癒合。止血、縫合均離不開縫線。嚴格地說,任何一種縫線對人體都是一種異物,它可引起組織的非細菌性炎症反應及排斥反應。這些反應都客觀地存在於每一個人體內。這種方法不僅需要很好的技術,操作不當很容易產生傷疤和感染。近年來,醫學領域獲得了長足發展,現在該是對傷口縫合術這種最普通和最常見的外科手術方法進行改造的時候了,而他們的研究成果正是這方面的一個突破。 

這一新技術得到了以色列衛生部的審核批准,研究人員已經對10位實施膽囊手術的患者進行臨床試驗,並取得了成功。因為傳統縫合技術不防水,而且血液或尿液可以從傷口處通過,容易造成嚴重的感染。與傳統縫合技術相比照,採用鐳射焊接技術,手術傷口癒合得更快,效果也更為理想。研究人員下一步計畫在剖腹產等產生較長傷口的手術上進行試驗,如果取得預期效果,將在幾年內投入商業應用。

Laser Tissue Bonding
Abstract Scientific Research

   Laser heating can be used to bond tissues. The exact mechanism of such laser welding or solding is not fully understood, but it has been found that it is critically dependent on the temperature of the tissue to be bond. We have developed a bonding system based on two optical fibers. One fiber is used to carry laser energy to heat a spot on tissue. The other fiber is part of a fiberoptic radiometer that is being used to determine the exact temperature of the heated spot. A computerized system makes use of the signal obtained from the radiometer to control the temperature. The temperature of a spot on a living tissue can be controlled to within 3°C .
   We have conducted theoretical and experimental studied of the heating of tissues by both CO2 laser (10.6µm) and GaAs diode laser(830nm). We found the optimal laser soldering conditions for cuts in tissues. Histological studies showed better results than standard suturing of cuts. Research is being continued now with different configuration of the laser soldering system in order to expend the capability of the system to solder tissues which we couldn't bond in the previous system configuration. In addition, research is being conducted on the soldering.
Selected Recent Applications: 
Laparoscopic Laser Soldering of Ureter
   We have developed a fiberopic CO2 laser system designed to operate through a rigid or a flexible endoscope. We tested the system for the laparoscopic repair of Ureteral Pelvic Junction obstructions in the porcine model. The system worked well in a complicated surgical procedure and in a difficult environment, in the presence of blood and urine. The experiments in all pigs were successful, there were no any significant complications, and we obtained good physiologic and anatomic results. This is the first time that such a system has been used for endoscopic laser bonding of tissues in animal models.

Repair of Dura by Laser Soldering
   We have developed a novel technique for dural reconstruction. This technique involves the soldering of a fascia patch to dura, and it would be useful for closing cuts or holes in the dura. The mean burst pressure was roughly 190 mm Hg, in comparison to the maximal pressure of CSF liquid in the brain, which is 15 mm Hg. A series of experiments on pig corpses clearly demonstrated that the method is very suitable for dural reconstruction. Long-term in vivo experiments were then successfully carried out on farm pigs. The animals were observed for a period of 10 days and no complications were noted. The histopathological results did not show any sign of thermal damage to the soldered tissue or to the underlying brain.

Laser Welding of the Skin
   Skin laser soldering research is carried out by our group for several years. We already successfully soldered rat, rabbit and farm pig skin in-vivo. We now conduct a clinical trial on human skin in a after gall bladder laparotomy at HaEmek Hospital (Afula).























Project Information
    Surgical cuts may be bonded if heated by a laser beam. There are two main methods of laser tissue bonding: 1. Laser welding that based on heating of the approximated edges of a tissue ; 2. Laser soldering that based on applying some soldering material (such as albumin) onto the edges of the incision and heating the solder (and the underlying tissues) by a laser beam. One might unify both these techniques. Both laser welding and laser soldering are inherently non-tactile techniques, welding does not involve a foreign body (i.e. sutures, clips, staples or synthetic glues) and soldering engages a solder substance only. Both procedures offer, in principle, many advantages with respect to standard techniques: (1) a watertight bond; (2) a faster wound healing process; (3) potentially reduced scar formation; (4) easier accessibility to some specific areas in a body and (5) a procedure is both faster to apply and easier to master.
    Even though laser soldering of tissue seems like a promising tissue bonding technique, it has problems that prevent it from being accepted as a common clinical practice. One of the main problems that should to be addressed is temperature control of bonded area. Another issue is reproducibility of the procedure. In order to achieve the satisfactory results, optimal soldering parameters have to be predetermined (i.e. laser power, temperature, solder type/thickness/concentration and so on). Further more, the use of this system in endoscopic application is limited by the dimension and configuration of the system.
    In earlier work we found that to obtain reliable and strong bonding of cuts in tissues one has to apply biological solder, such as albumin, and heat the tissues under temperature control to roughly 60-65°C. The Applied Physics Group at Tel Aviv University has developed a several fiberoptic laser systems which can heat a spot on tissue (or on a solder layer) and keep its temperature constant to within 3-5°C. The principles of all of our systems are as follows:
(a) Laser Based Heating: The laser (either CO2 laser or GaAs Diode laser or both) output power is
    coupled to a fiber whose distal end is fixed in a hand-piece. The laser energy absorbs either in the
    solder or in the tissue and rise its temperature.
(b) Temperature Monitoring: The heated spot emits infrared radiation, whose intensity I is proportional
     to the temperature - T of the heated spot (according to Stefan-Boltzman law). For modest heating
    (less than 100°C) most of the radiation is in the mid-IR. This radiation is picked up by a AgClBr fiber
    ("sensor" fiber") and transmits to a pyroelectric IR detector. The signal V generates by the detector is
   proportional to the temperature T. The temperature measurements are carried out by this fiberoptic
    infrared radiometer in a non-contact fashion.
(c) Temperature Control: The signal V is read by a PC. A dedicated computer program is used to
    determine the temperature T. The PC modifies the laser power in order to maintain the predetermined
   set-point temperature. The temperature controlled laser soldering system is depicted schematically in
    the following picture.
Those systems have already been successfully used for laser soldering of different tissue types, including skin‎ (1), cornea(2), conjunctiva, trachea(3,4), bowel(5), urinary bladder(6), ureter(7), blood vessels(8) and dura(‎9,‎10). Examples of our work on bowel (movie 1) and conjunctiva (movie 2) is presented below.

Chronology
• 1994-2000: urinary bladder welding and soldering (in vitro and in vivo, CO2) in rats and rabbits
• 1997: ocular tissue (cornea and choroid) welding (in vitro and in vivo, CO2) pig
• 2001-2004: skin soldering (in vivo, CO2 and GaAs), rat, rabbit pig. A clinical trial is permitted.
• 2001: closure of arteriotomy incisions in femoral vein of rat (in vivo, CO2 )
• 2002: laparoscopic procedure for repair of ureteropelvic junction obstruction in the porcine model
               (in vivo, CO2)
• 2004: end-to-end small bowel anastomoses in rabbit model
• 2005: pig trachea soldering using flexible albumin bands (in vitro, CO2 and GaAs)
• 2005: reconstruction of dural defects by laser soldering of fascia patches to dura in porcine model
               (in vivo, CO2)
• 2006: end-to-end colon anastomoses (in vivo, CO2; in vitro, GaAs)
• 2006: end-to-end conjunctiva soldering ( in vitro, GaAs)

Current Research
• Human clinical trials of skin cut soldering.
• Setting up new principle based temperature controlled laser soldering system.
• Tissue bonding mechanism research.
• Albumin characterization.
• Fiber optic based laser tissue ablation system.

References
1. Simhon, D., Halpern, M., Brosh, T., Vasilyev, T., Ravid, A., Tennenbaum, T., Nevo, Z., and Katzir,
  A., "immediate tight sealing of skin incisions using an innovative temperature controlled laser
  soldering device: in-vivo study in porcine skin," Ann.Surg., vol. 245, no. 2, pp. 206-213, 2007
2. Strassmann, E., Loya, N., Gaton, D., Ravid, A., Kariv, N., Weinberger, D., and Katzir, A.,
   "temperature controlled CO2 laser soldering of pig cornea," Proc.SPIE, vol. 4609, pp. 222-228, 2002.
3. Shapira, L., Rabi, Y., Vasserman, I., Vasilyev, T., Sharvit, D., Hardy, A., and Katzir, A., "icg dyed
    albumin and diode laser heating for soldering of the trachea," Proc.SPIE, vol. 6078, pp. 172-176,
   2006.
4. Sharvit, D., Vasilyev, T., Vasserman, I., Simhon, D., Kariv, N., DeRowe, A., and Katzir, A., "CO2
    temperature controlled laser soldering of pig trachea incisions in vitro using flexible albumin bands,"
    Proc.SPIE, vol. 5686, pp. 242-247, 2005.
5. Simhon, D., Kopelman, D., Hashmonai, M., Vasserman, I., Dror, M., Vasilyev, T., Halpern, M.,
    Kariv, N., and Katzir, A., "end-to-end small bowel anastomosis by temperature controlled CO2 laser
    soldering and an albumin stent - a feasibility study," Proc.SPIE, vol. 5312, pp. 176-185, 2004.
6. Lobel, B., Eyal, O., Kariv, N., and Katzir, A., "temperature controlled CO2 laser welding of soft
   tissues: urinary bladder welding in different animal models (rats, rabbits, and cats)," Lasers Surg.Med.,
    vol. 26, pp. 4-12, 2000.
7. Shumalinsky, D., Lobik, L, Cytron, S., Halpern, M., Vasilyev, T., Ravid, A., and Katzir, A.,
   "laparoscopic laser soldering for repair of ureteropelvic junction obstruction in the porcine model,"
   J.of Endourology, vol. 18, no. 2, pp. 177-181, 2004.
8. Leshem, D., Vasilyev, T., Ravid, A., Gat, A., Kariv, N., Katzir, A., and Gur, E., "CO2 laser soldering
   of arteriotomy incisions in blood vessels of rats, using a temperature-controlled fiber optic system,"
   Proc.SPIE, vol. 4949, pp. 199 -206, 2003.
9. B. Forer, T. Vasilyev, T. Brosh, N. Kariv, Z. Gil, D. M. Fliss, and A. Katzir. Repair of Pig Dura In
   Vivo Using Temperature Controlled CO2 Laser Soldering. Lasers in Surgery and Medicine 37 (4):286-
   292, 2005.
10. B. Forer, T. Vasilyev, T. Brosh, N. Kariv, L.L. Trejo, Z. Gil, A. Katzir and D. M. Fliss. Dural defect
    repair with fascia by a CO2 laser system in a porcine model. Laryngoscope. 116(6), pp.1002-6, 2006.

A new laser technique from TAU seals and heals wounds 
     Not much has changed in the last 2,000 years when it comes to suturing together cuts and wounds. Even with microsurgery techniques, infection and permanent scarring remain major concerns. To minimize these dangers, doctors tried using a carbon dioxide laser to seal wounds, but without the ability to control the heat of the laser, the technique created even greater risks. Until now.
 Using carbon dioxide lasers to seal wounds inside the body and out with a technique known as “laser welding,” a team of Tel Aviv University researchers have perfected a new device to heat body tissue in a precisely controlled manner. The work of the research team, headed by Prof. Abraham Katzir from
TAU’s Applied Physics Group in the School of Physics and Astronomy at Tel Aviv University,

   could change the way surgeons bond cuts on the surface of our skin and inside our bodies during surgery.

   With the new device, if the laser begins to overheat and risks burning the tissue, laser power is reduced, and if the temperature is too low to complete a closure, laser power in increased appropriately.

Getting the Temperature Just Right

   Earlier attempts to use carbon dioxide lasers for bonding of cuts in the operating room or in clinics were not very successful. Causing thermal damage, the lasers either “undercooked” or “overcooked” the patient’s delicate tissues.

   Prof. Katzir set out to find the right temperature for optimal wound healing, and to perfect a device that could maintain this temperature. He is the first to apply the carbon dioxide laser, coupled to optical fibers, for wound closure under a tight temperature control. His innovation is in the use of unique optical fibers made from silver halide developed at Tel Aviv University. The fibers deliver the laser’s energy to heat the bonded cut and are used for controlling the temperature. They also make it possible to bond tissues inside the body.

“Sutures or stitches are not water tight, and blood or urine can pass through cuts, causing severe infection,” he says. “Also, in many cases, a surgeon needs great skill to perform internal stitching, or in bonding tiny blood vessels, or in mending cuts on the skin so there will be no trace left on the body.”

Inside and Out

  Prof. Katzir and his colleagues have carried out successful clinical trials on people undergoing gall bladder removal surgery. At the close of the surgery, four cuts were left on the skin of the abdomen, two of which were sutured and two laser-bonded. The results of the trials suggest that the laser-bonded tissues heal faster, with less scarring.

   Successful preliminary experiments demonstrated that the new technique can be used to bond cuts on the cornea, bladder, intestines, blood vessels or trachea. It may also be used for bonding tissues inside the body on organs such as the kidney, and even in brain surgery. Perfect for healing soft tissues, the laser may prevent an enormous amount of trauma when used for closing internal wounds.

Heading for the FDA

Working with the permission of Israel’s Ministry of Health, the team will soon be treating longer cuts, such as in the case of hernia operations, and is expected to apply to the FDA in the U.S. for larger-scale trials. If successful in these larger tests, the basic research could be developed into a commercial product within a few years.

“We think plastic surgeons will especially love this invention. Bonding tissues that heal well without scarring is a true art that few people possess,” says Prof. Katzir. This method, he says, will be much easier to master than suturing and will generate a watertight bond, preventing infections and accelerating healing.

“It could also become a device for the battlefield, allowing soldiers to heal each other on contact with a laser wand,” says Prof. Katzir, who currently holds the Carol and Mel Taub Chair in Applied Medical Physics in the School of Physics and Astronomy at Tel Aviv University.


Wound Healing 发布人 SMIRAMIS150

Healing Wound with Laser Stitches




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