Experimental research of plastic surgery in China
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《中华医药杂志》英文版
【Abstract】 Plastic surgery is one of the most popular clinical specialties of general surgery. In the late twentith century, with the fast progress of global science and technology, plastic surgery has been involved with research works, and combined with experimental and lab study. We here review the stories briefly the progress of experimental plastic surgery works in China, involving microsurgery, skin flaps transfer, hypertrophic scar, lymph edema of extremities and tissue engineering and other subjects to the development of clinical plastic surgery of the world.
【Key words】 plastic and reconstructive surgery；experimental research；microsurgery；hypertrophic scar；lymph edema;flaps;tissue engineering
Plastic surgery is one of the specialities of surgery which mostly emphases on clinical works. People all over the world always admire a famous plastic surgeon for his wonderful artistic and operative technique. Since the late half of the twentith century, with the fast progress of global science and technology, plastic surgery has begun to be involved with research works and combined with experimental and lab study. Since then, plastic surgery has enlarged its range of therapy, reduced the period of treatment, improved the technique of repair and reconstruction and mixed with new technique of other fields. Therefore, the level of plastic surgery has been enhanced much more than before. Plastic surgery has improved and expanded itself in its content, so it can be accordingly named as “Plastic and Reconstructive Surgery” or “Reparative and Reconstructive Surgery”. The following stories review briefly the progress of experimental plastic surgery research works in China.
Pioneering works in development of microsurgery
Early in 1960, Jacobson and Suarez of USA firstly indicated the value of microsurgery. They reported the experimental microsurgical anastomosis on 0.8~1.0mm diameter vessels and performed kidney and heart transplantation in rats with success. This report had blazed a way in experimental surgery, but yet had not been utilized clinically. In 1964~1965, the first author started to replant free flap of dogs groin flap in situ with anastomosis of small vessel, and also transplanted this free flap from left side to right side, and even to replant rabbits ear with success. However at that time, our facilities were very bad. We could only use 4 times magnifying glasses, self made needles by stainless steel wire, and utilized nurses hair or split from 6~0 silk as suture material. Then, our works were interrupted by the Culture Revolution. In 1972, Harii of Japan and, Daniel of USA and Dongyue Yang from PRC in 1973 in turn reported successful free flap transplantation clinically.
These achievements then promoted the popular use and the progress of microsurgery in plastic surgery, traumatic orthopaedics and maxillofacial surgery, etc. Thereafter, with the development of experimental study of microanatomy, many other free skin flaps, musculocutaneous flaps and osteo-muscular-cutaneous flaps, etc, have been developed widely. They can be used in many different clinical conditions in order to achieve one stage repair and reconstruction. For example, in plastic and reconstructive surgery, we have transplanted free jejunum to repair esophagus stricture. We also have successfullyreplanted more than 25 cases of avulsion of the scalp. Hair can grow after the operation and to avoid balding for life. Now, in our unit, the number of success the avulsed patients may be one of the largest in the world. In orthopedic surgery, surgeons can use the technique in emergency patients with fracture and large soft tissue defect, thus the patient can be avoided to be handicapped for life after regular amputation of the limbs. Now the technique of microsurgery has become one of the basic techniques to be owned by most surgeons.
Experimental study of the ratio of length to width of skin flap Transposition of skin flap is one of the most commonly method used in plastic surgery. Transplantation of skin flap and conjoint superficial fascia and fat need a vascular pedicle which contains enough pedical arterial and veinous blood circulation. The ratio of the width of pedical to the length of flap must be suitable, otherwise the distal part of flap will be necrosed. For example, in a single random pedical flap, the ratio of length to width should be designed 1.5~2∶1(for example, if the width of the flap is 5cm, the flap can not be longer than 7.5~10.0cm). So many plastic surgeons over the world have tried to use medicine or other methods to improve this ratio limit. Now the hot point of study is reported that calcium contest substance may improve the ischemic endurance of the flap. Guohua Yang, et.al. in China have found that there is impactful effect of anti-lipid peroxidization when using verapamil on island flap in rats. Li Zhuang, et al have proved in animal experiment that verapamil can improve the ischemic endurance of flap as well. But in general, this medical treatment is still in exploring stage and not available for clinical use. Moreover after the development of microsurgical technique, anatomists have studied distribution of vessels in human skin, fascia and muscle in detail. At the same time, surgeons are also observing in practice and find in turn that the surface layer of human skin can be compartmentalized into many areas which have independent vascular supplies respectively. Therefore, axial flap, a new concept and classification has been established. This new finding has broken the idea that length and width of flap must be limited in a certain ratio. Since then, many new techniques have been developed, such as musculocutaneous flap, osteomuscular flap and neurosteomuscular flap etc. These new techniques make it possible to repair and reconstruct in one and primary stage after serious injury or reconstruct large defects after tumour resection. This kind of axial flap not only can be transplanted pediclely in all orientations, but also can be transplanted to other part of the body freely by microsurgical technique in one stage. This new method of repair pushes the technique of autologus transplantation of tissues to a higher level.
Experimental study of lymphedema of limbs Lymphatic system is the second circular system of body besides the blood circulation system. It can absorb the large molecules protein from tissue and interstitial space and finally transport back to veins. It is important to maintain the body fluid balance and substances exchange. In addition, local lymph nodes also have the function of filtration, defense and immunity. Once the lymph vessels were obstructed by occlusion, the extremities of limbs would be seen swollen with lymphedema (so called elephantiasis in late stage), because of the stasis of lymph fluid. Many factors can be involved in lymphedema, such as late stage of filariasis,infection,chronic inflammation,radiotherapy after removal of tumor,amputation because of trauma, congenital developmental dysplasia of lymphatic system etc. Lymphedema of limbs, especially late stage lymphedema, has always been difficult to treat. The first author invented the heat and bandage treatment by infrared ray in 1964, and later improved to use microwave heating. These treatments had been proved clincally with good therapeutic results. The excellent rate was up to 68%. But there was still not a good way to deal with those huge type of lymphedema(huge elephantiasis). Experimental studies of lymphedema had been studied early all over the world. Those experimental studies included such aspects as the establishment of animal model, the etiological diagnosis and the way to treatment.
The objective of the establishment of animal model of lymphedema is for the further study of diagnosis and treatment. Rats, rabbits and dogs were used mostly. During 1970s~1980s,the methods used included removal of part of skin,subcutaneous tissue,conjunctive tissue and lymph vessels around blood vessels and nerves or interval gap muscles and local popliteal lymph nodes in animals limbs. Later, in order to increase the successful rate, after the operation, radiotherapy was used. The latest study confirmed that the radiotherapy after operation could greatly increase the successful rate of establishment of lymphedema models. On the other hand, in the aspect of contrast medium in diagnosis, the earliest used was iodine. Since 1988, isotope(Isovist-300) has been used, which makes indirect lymph angiography come true. Now the application of radionuclide lymphoscintigraphy and 198Au lymphoscintigraphy in lower extremities had produced good results. All these techniques now used clinically came from animal experiment. Furthermore, CT, MRI,etc. are also helpful to diagnose all kinds of lymphedema.
As for the treatment of lymph edema, there are two conservative methods and surgical treatment. Besides the heating and bandaging treatment mentioned above, conservative treatment also includes the complex physical therapy(CPT) created by Mr. and Mrs. Fldi of Germany. Those two conservative methods have been officially recognized by the International Lymphological Society. Surgical treatment was greatly involved after the development of microsurgery. The principle of the surgery is end-to-end or end-to-side anastomosing of the distal ends of occlusion lymph vessels to the afferent local small veins in order to recover the lymph circulation. In 1970s~1980s, Obrien of Australia, Olszewski of Poland, Campisi of Italy and our Chinese team did much advanced works on the surgical treatment of lymph edema. Microlymphatic surgery has now become a specialty, which includes anastomosing of lymph vessels and veins, sectional lymph vessels transplantation and bridging, vein transplant bridging anastomosis, etc. These surgical techniques all underwent the course from animal experiment to clinical use. Now with this kind of bridging operation excellent results have been achieved in treating huge late stage lymphedema in our department.
The study on prevention and treatment of hypertroplic scar Scar formation is an inevitable result of wound healing. We may say that there is no wound healing without scar. However, if scar formation beyond normal range, complications can occur, such as disfiguration and functional handicap. The most awkward scar in clinic occurs on face and hands, but in fact, all kinds of scar and corresponding complication can occur were during the wound healing process. At present, the scar with which both doctors and patients mostly are puzzled is hyperplastic scar and keloid. The response of scar formation is variable from different races. Caucasians (White People)can hardly result hyperplastic incisional scar after operation. However, the Black people is so sensitive that any small wound may cause local obvious hyperplastic scar or even keloid. In orientals, the degree hyperplasia scar is in between those two races. Some peoples scar may disappear in six or eight months, but most people may prolong even for years together with pain, itching and disfiguration. Contracture of tissue around scar and functional handicap often occur. Experimental study of the scar has been carried on all over the world. The earliest finding was that in the microscope study the scar hyperplasia is caused by overly aggradation of fibrous cells and collagen. Now the observation has developed to the level of molecular cytology and immunohistochemistry.
The treatment of scar is still an unsolved problem. In the last ten years, not only the plastic surgeons but also research workers have found much for the forming mechanism and precaution of scar formation. Although many articles have been published, there was still not great breakthrough in effective restraining scar hyperplasia. In the last century, the results of animal experiments in lambs confirmed that skin wound can heal without scar in fetus. It was a hint that wound healing of mammals does not always lead to scar. After that, in many kinds of animal experiments, some different recovery mechanisms of fetal and adult animals were discoveried. Above all, the different concentration of transforming growth factor(TGF)-β may be the key factor. Fetal scar contains little TGF-β while in keloid and hyperplastic scar, the amount of TGF-β and its receptor is far more than that in normal tissue. Other difference is that of expression of genes which are correlative with regeneration and growth of tissues, such as the Wyn Genes, the Homeobox Genes, and so on. Based on the findings above, Shah, et al. creatively injected antibody to TGF-β into wounds of adult rats and found the scarring in adult wounds could be effectively controlled. This was the first step of interventional experimental study on scarring.
Ashcroft, et al. used mice as the model in which the Smad 3 gene was knocked out. This procedure showed that cutting off the signal transmit of TGF-β could accelerate wound healing, impair local inflammatory response, decrease wound excess secretion and reduce scar sige. These findings gave the feasibility that intervening the function of TGF-β in the genetic level could prevent scarring of the wound. In our unit, Lui Wei et al. had used gene therapy in inbibiting wound scarring in a recent study with hopeful result. Their study concluded that adenovirus mediated over-expression of tTGF-βRII can block TGF-β signaling and inhibit wound scarring, and thus can serve as a gene therapy strategy to control wound scarring. Suppose that the genetic therapy could be used in the future, it may bring a breakthrough in clinical prevention and treatment of scar. With the development of biological science and finding of new genes of tissue regeneration and using of cutaneous stem cells, it would be possible that skin could totally regenerate without scar during wound healing.
Tissue engineering:a hot spot in experimental study of plastic surgery
In plastic surgery, the main method of repairing defect of tissues is tissue transplantation. Up to now, the source of tissue is still autologous. The shortcoming is that while repairing one tissue defect, another wound must be sacrificed. The development of tissue engineering may change this conventional rule. Tissue engineering can reconstruct massive autologous tissue through ectogenesis from a few autologous cells. This imagmative idea has been proved in many experimental studies at our Shanghai Tissue Engineering Research Center and other centers in the world. The most used repairing tissues, such as bone, cartilage, tendor and skin, have been successfully reconstructed by tissue engineering in animals. Bone tissue cells have been used to repair cranial defect in lambs, joint cartilage defect in pigs, flexor tendon defect in hens and total layer of skin defect in pigs. Furthermore, tissue engineered peripheral nerve has been proved to have similar function as autologous nerve. Most importantly,some tissue engineering products have begun to be appid to clinical plastic surgery and achieved preliminary success. For instance, our team has successfully repaired massive cranial defect in a patient using bone marrow stem cells seeded decelluar bone matrix. The importance of this method is that massive tissue defect is repaired with autologous tissue without causing any donor tissue wound(only needs 5~10ml bone marrow). Similarly, its reasonable to believe that all kinds of tissue engineered organs could be produced in clinic in the future, and plastic surgeons can repair defects without causing other donor tissue wound. Recently, the new technology of inducing differentiation of fetal stem cells has provided a base for further development of tissue engineering. Therefore, the future is very encouraging.
At present, in China, the research of tissue engineering has been listed in as one of the National 973 Science and Technology Research Items. Yilin Cao of Shanghai and Zhiming Yang of Chengdu have established sweeping experimental centers with advanced devices and equipments. Acheivements have been obtained in last few years and have reached the advanced level in the world.
Anyway, any progress and advancement of science can not be separated from experimental study. The goal of medicine is to cure diseases and rescue peoples life.Years of clinical practice and experience accumulation are important. However, with the progress and new discovery of science, the general advancement of medical science will be inevitable in a special way of crossing, communication and cooperation with each other. From these points of view, any illumination, discovery and bold imaginination may induce instuctive experimental study. Then, any laboratory achievements may lead to improve the clinical practice. This kind of recycle may make the medical practice developing continuously and renew with time. Although plastic surgery in China is a new surgical specialty which develops rather lately, both clinical practice and experimental study have brought the development of plastic surgery to a quite high level.
REFERENCES
1. Converse JM. Reconstructive Plastic Surgery, Phila, Saunders Co,1964,1-16.
2. Marcarthy JG. Plastic Surgery, W. B. Saunders Co,1990.
3. Chang TS. Plastic Reconstructive Surgery, Shanghai Technology pub. Co,2002 (In Chinese).
4. Chang TS. The Princple, Practise and Application of Microsurgery. Singapore World pub. Co,1996.
5. Gan. CL. Experimental Study of lymph node autotransplantations in rats, Chinese Med,1998,111(3):239-241.
6. G. CL. Microwave heating in the Management of postmastectomy of upper lymph edema: Annals of Plastic Surgery,1998, 2-10.
7. Chang TS. Heating and Bandage Treatment for Lymphedema of the Extremities (1045cases). Thai J. of Surgery,1985,(1)
8. Degni M. New technique of lymphaticovenons Anastomosis, J Cardiovasc, Surg,1979,19:577.
9. Chu SS,et. al. The modern microsurgery.Hunan Science Press,1994.
10. Chen CW,et al. The Microsurgery, 1985, Peoples Health Pub.CO (in Chinese).
11. Radovan C. Breast reconstruction after mastectomy using the teacorary expander. Plascic and Reconstructive Surgery,1984,69,199.
12. Chang TS,et. al. Tissue Expander used to treat scaer alopisia, The Chinese J. of PRS,1985,1:241.
13. Cao YL,Vacanti, JP,et al. Transplantation of chondrocytes utilizing a polymer-cell construct to produce tissue engineered cartilage in the shape of a human ear. Plast Reconstr Surg,1997,100(2):297-302.
14. Yang CM. Basic And Chinical Research on Tissue Engineering.Sichuan Science Press，2000,
15. Cao YL, et al. Replantation of avulsion of the scalp. Chinese J Microsurgery,1991,14(4) :223.
16. Liu Wei, et al. Inhibiting scar formation in rat cutaneous wounds by blocking TGF-βsignaling. Natl Med J China,2003,83(1).
The 9th Peoples Hospital, Shanghai 210000,China
(Editor Shang Zhi-wei)(ZHANG Di-sheng，ZHOU Yi-qu)
【Key words】 plastic and reconstructive surgery；experimental research；microsurgery；hypertrophic scar；lymph edema;flaps;tissue engineering
Plastic surgery is one of the specialities of surgery which mostly emphases on clinical works. People all over the world always admire a famous plastic surgeon for his wonderful artistic and operative technique. Since the late half of the twentith century, with the fast progress of global science and technology, plastic surgery has begun to be involved with research works and combined with experimental and lab study. Since then, plastic surgery has enlarged its range of therapy, reduced the period of treatment, improved the technique of repair and reconstruction and mixed with new technique of other fields. Therefore, the level of plastic surgery has been enhanced much more than before. Plastic surgery has improved and expanded itself in its content, so it can be accordingly named as “Plastic and Reconstructive Surgery” or “Reparative and Reconstructive Surgery”. The following stories review briefly the progress of experimental plastic surgery research works in China.
Pioneering works in development of microsurgery
Early in 1960, Jacobson and Suarez of USA firstly indicated the value of microsurgery. They reported the experimental microsurgical anastomosis on 0.8~1.0mm diameter vessels and performed kidney and heart transplantation in rats with success. This report had blazed a way in experimental surgery, but yet had not been utilized clinically. In 1964~1965, the first author started to replant free flap of dogs groin flap in situ with anastomosis of small vessel, and also transplanted this free flap from left side to right side, and even to replant rabbits ear with success. However at that time, our facilities were very bad. We could only use 4 times magnifying glasses, self made needles by stainless steel wire, and utilized nurses hair or split from 6~0 silk as suture material. Then, our works were interrupted by the Culture Revolution. In 1972, Harii of Japan and, Daniel of USA and Dongyue Yang from PRC in 1973 in turn reported successful free flap transplantation clinically.
These achievements then promoted the popular use and the progress of microsurgery in plastic surgery, traumatic orthopaedics and maxillofacial surgery, etc. Thereafter, with the development of experimental study of microanatomy, many other free skin flaps, musculocutaneous flaps and osteo-muscular-cutaneous flaps, etc, have been developed widely. They can be used in many different clinical conditions in order to achieve one stage repair and reconstruction. For example, in plastic and reconstructive surgery, we have transplanted free jejunum to repair esophagus stricture. We also have successfullyreplanted more than 25 cases of avulsion of the scalp. Hair can grow after the operation and to avoid balding for life. Now, in our unit, the number of success the avulsed patients may be one of the largest in the world. In orthopedic surgery, surgeons can use the technique in emergency patients with fracture and large soft tissue defect, thus the patient can be avoided to be handicapped for life after regular amputation of the limbs. Now the technique of microsurgery has become one of the basic techniques to be owned by most surgeons.
Experimental study of the ratio of length to width of skin flap Transposition of skin flap is one of the most commonly method used in plastic surgery. Transplantation of skin flap and conjoint superficial fascia and fat need a vascular pedicle which contains enough pedical arterial and veinous blood circulation. The ratio of the width of pedical to the length of flap must be suitable, otherwise the distal part of flap will be necrosed. For example, in a single random pedical flap, the ratio of length to width should be designed 1.5~2∶1(for example, if the width of the flap is 5cm, the flap can not be longer than 7.5~10.0cm). So many plastic surgeons over the world have tried to use medicine or other methods to improve this ratio limit. Now the hot point of study is reported that calcium contest substance may improve the ischemic endurance of the flap. Guohua Yang, et.al. in China have found that there is impactful effect of anti-lipid peroxidization when using verapamil on island flap in rats. Li Zhuang, et al have proved in animal experiment that verapamil can improve the ischemic endurance of flap as well. But in general, this medical treatment is still in exploring stage and not available for clinical use. Moreover after the development of microsurgical technique, anatomists have studied distribution of vessels in human skin, fascia and muscle in detail. At the same time, surgeons are also observing in practice and find in turn that the surface layer of human skin can be compartmentalized into many areas which have independent vascular supplies respectively. Therefore, axial flap, a new concept and classification has been established. This new finding has broken the idea that length and width of flap must be limited in a certain ratio. Since then, many new techniques have been developed, such as musculocutaneous flap, osteomuscular flap and neurosteomuscular flap etc. These new techniques make it possible to repair and reconstruct in one and primary stage after serious injury or reconstruct large defects after tumour resection. This kind of axial flap not only can be transplanted pediclely in all orientations, but also can be transplanted to other part of the body freely by microsurgical technique in one stage. This new method of repair pushes the technique of autologus transplantation of tissues to a higher level.
Experimental study of lymphedema of limbs Lymphatic system is the second circular system of body besides the blood circulation system. It can absorb the large molecules protein from tissue and interstitial space and finally transport back to veins. It is important to maintain the body fluid balance and substances exchange. In addition, local lymph nodes also have the function of filtration, defense and immunity. Once the lymph vessels were obstructed by occlusion, the extremities of limbs would be seen swollen with lymphedema (so called elephantiasis in late stage), because of the stasis of lymph fluid. Many factors can be involved in lymphedema, such as late stage of filariasis,infection,chronic inflammation,radiotherapy after removal of tumor,amputation because of trauma, congenital developmental dysplasia of lymphatic system etc. Lymphedema of limbs, especially late stage lymphedema, has always been difficult to treat. The first author invented the heat and bandage treatment by infrared ray in 1964, and later improved to use microwave heating. These treatments had been proved clincally with good therapeutic results. The excellent rate was up to 68%. But there was still not a good way to deal with those huge type of lymphedema(huge elephantiasis). Experimental studies of lymphedema had been studied early all over the world. Those experimental studies included such aspects as the establishment of animal model, the etiological diagnosis and the way to treatment.
The objective of the establishment of animal model of lymphedema is for the further study of diagnosis and treatment. Rats, rabbits and dogs were used mostly. During 1970s~1980s,the methods used included removal of part of skin,subcutaneous tissue,conjunctive tissue and lymph vessels around blood vessels and nerves or interval gap muscles and local popliteal lymph nodes in animals limbs. Later, in order to increase the successful rate, after the operation, radiotherapy was used. The latest study confirmed that the radiotherapy after operation could greatly increase the successful rate of establishment of lymphedema models. On the other hand, in the aspect of contrast medium in diagnosis, the earliest used was iodine. Since 1988, isotope(Isovist-300) has been used, which makes indirect lymph angiography come true. Now the application of radionuclide lymphoscintigraphy and 198Au lymphoscintigraphy in lower extremities had produced good results. All these techniques now used clinically came from animal experiment. Furthermore, CT, MRI,etc. are also helpful to diagnose all kinds of lymphedema.
As for the treatment of lymph edema, there are two conservative methods and surgical treatment. Besides the heating and bandaging treatment mentioned above, conservative treatment also includes the complex physical therapy(CPT) created by Mr. and Mrs. Fldi of Germany. Those two conservative methods have been officially recognized by the International Lymphological Society. Surgical treatment was greatly involved after the development of microsurgery. The principle of the surgery is end-to-end or end-to-side anastomosing of the distal ends of occlusion lymph vessels to the afferent local small veins in order to recover the lymph circulation. In 1970s~1980s, Obrien of Australia, Olszewski of Poland, Campisi of Italy and our Chinese team did much advanced works on the surgical treatment of lymph edema. Microlymphatic surgery has now become a specialty, which includes anastomosing of lymph vessels and veins, sectional lymph vessels transplantation and bridging, vein transplant bridging anastomosis, etc. These surgical techniques all underwent the course from animal experiment to clinical use. Now with this kind of bridging operation excellent results have been achieved in treating huge late stage lymphedema in our department.
The study on prevention and treatment of hypertroplic scar Scar formation is an inevitable result of wound healing. We may say that there is no wound healing without scar. However, if scar formation beyond normal range, complications can occur, such as disfiguration and functional handicap. The most awkward scar in clinic occurs on face and hands, but in fact, all kinds of scar and corresponding complication can occur were during the wound healing process. At present, the scar with which both doctors and patients mostly are puzzled is hyperplastic scar and keloid. The response of scar formation is variable from different races. Caucasians (White People)can hardly result hyperplastic incisional scar after operation. However, the Black people is so sensitive that any small wound may cause local obvious hyperplastic scar or even keloid. In orientals, the degree hyperplasia scar is in between those two races. Some peoples scar may disappear in six or eight months, but most people may prolong even for years together with pain, itching and disfiguration. Contracture of tissue around scar and functional handicap often occur. Experimental study of the scar has been carried on all over the world. The earliest finding was that in the microscope study the scar hyperplasia is caused by overly aggradation of fibrous cells and collagen. Now the observation has developed to the level of molecular cytology and immunohistochemistry.
The treatment of scar is still an unsolved problem. In the last ten years, not only the plastic surgeons but also research workers have found much for the forming mechanism and precaution of scar formation. Although many articles have been published, there was still not great breakthrough in effective restraining scar hyperplasia. In the last century, the results of animal experiments in lambs confirmed that skin wound can heal without scar in fetus. It was a hint that wound healing of mammals does not always lead to scar. After that, in many kinds of animal experiments, some different recovery mechanisms of fetal and adult animals were discoveried. Above all, the different concentration of transforming growth factor(TGF)-β may be the key factor. Fetal scar contains little TGF-β while in keloid and hyperplastic scar, the amount of TGF-β and its receptor is far more than that in normal tissue. Other difference is that of expression of genes which are correlative with regeneration and growth of tissues, such as the Wyn Genes, the Homeobox Genes, and so on. Based on the findings above, Shah, et al. creatively injected antibody to TGF-β into wounds of adult rats and found the scarring in adult wounds could be effectively controlled. This was the first step of interventional experimental study on scarring.
Ashcroft, et al. used mice as the model in which the Smad 3 gene was knocked out. This procedure showed that cutting off the signal transmit of TGF-β could accelerate wound healing, impair local inflammatory response, decrease wound excess secretion and reduce scar sige. These findings gave the feasibility that intervening the function of TGF-β in the genetic level could prevent scarring of the wound. In our unit, Lui Wei et al. had used gene therapy in inbibiting wound scarring in a recent study with hopeful result. Their study concluded that adenovirus mediated over-expression of tTGF-βRII can block TGF-β signaling and inhibit wound scarring, and thus can serve as a gene therapy strategy to control wound scarring. Suppose that the genetic therapy could be used in the future, it may bring a breakthrough in clinical prevention and treatment of scar. With the development of biological science and finding of new genes of tissue regeneration and using of cutaneous stem cells, it would be possible that skin could totally regenerate without scar during wound healing.
Tissue engineering:a hot spot in experimental study of plastic surgery
In plastic surgery, the main method of repairing defect of tissues is tissue transplantation. Up to now, the source of tissue is still autologous. The shortcoming is that while repairing one tissue defect, another wound must be sacrificed. The development of tissue engineering may change this conventional rule. Tissue engineering can reconstruct massive autologous tissue through ectogenesis from a few autologous cells. This imagmative idea has been proved in many experimental studies at our Shanghai Tissue Engineering Research Center and other centers in the world. The most used repairing tissues, such as bone, cartilage, tendor and skin, have been successfully reconstructed by tissue engineering in animals. Bone tissue cells have been used to repair cranial defect in lambs, joint cartilage defect in pigs, flexor tendon defect in hens and total layer of skin defect in pigs. Furthermore, tissue engineered peripheral nerve has been proved to have similar function as autologous nerve. Most importantly,some tissue engineering products have begun to be appid to clinical plastic surgery and achieved preliminary success. For instance, our team has successfully repaired massive cranial defect in a patient using bone marrow stem cells seeded decelluar bone matrix. The importance of this method is that massive tissue defect is repaired with autologous tissue without causing any donor tissue wound(only needs 5~10ml bone marrow). Similarly, its reasonable to believe that all kinds of tissue engineered organs could be produced in clinic in the future, and plastic surgeons can repair defects without causing other donor tissue wound. Recently, the new technology of inducing differentiation of fetal stem cells has provided a base for further development of tissue engineering. Therefore, the future is very encouraging.
At present, in China, the research of tissue engineering has been listed in as one of the National 973 Science and Technology Research Items. Yilin Cao of Shanghai and Zhiming Yang of Chengdu have established sweeping experimental centers with advanced devices and equipments. Acheivements have been obtained in last few years and have reached the advanced level in the world.
Anyway, any progress and advancement of science can not be separated from experimental study. The goal of medicine is to cure diseases and rescue peoples life.Years of clinical practice and experience accumulation are important. However, with the progress and new discovery of science, the general advancement of medical science will be inevitable in a special way of crossing, communication and cooperation with each other. From these points of view, any illumination, discovery and bold imaginination may induce instuctive experimental study. Then, any laboratory achievements may lead to improve the clinical practice. This kind of recycle may make the medical practice developing continuously and renew with time. Although plastic surgery in China is a new surgical specialty which develops rather lately, both clinical practice and experimental study have brought the development of plastic surgery to a quite high level.
REFERENCES
1. Converse JM. Reconstructive Plastic Surgery, Phila, Saunders Co,1964,1-16.
2. Marcarthy JG. Plastic Surgery, W. B. Saunders Co,1990.
3. Chang TS. Plastic Reconstructive Surgery, Shanghai Technology pub. Co,2002 (In Chinese).
4. Chang TS. The Princple, Practise and Application of Microsurgery. Singapore World pub. Co,1996.
5. Gan. CL. Experimental Study of lymph node autotransplantations in rats, Chinese Med,1998,111(3):239-241.
6. G. CL. Microwave heating in the Management of postmastectomy of upper lymph edema: Annals of Plastic Surgery,1998, 2-10.
7. Chang TS. Heating and Bandage Treatment for Lymphedema of the Extremities (1045cases). Thai J. of Surgery,1985,(1)
8. Degni M. New technique of lymphaticovenons Anastomosis, J Cardiovasc, Surg,1979,19:577.
9. Chu SS,et. al. The modern microsurgery.Hunan Science Press,1994.
10. Chen CW,et al. The Microsurgery, 1985, Peoples Health Pub.CO (in Chinese).
11. Radovan C. Breast reconstruction after mastectomy using the teacorary expander. Plascic and Reconstructive Surgery,1984,69,199.
12. Chang TS,et. al. Tissue Expander used to treat scaer alopisia, The Chinese J. of PRS,1985,1:241.
13. Cao YL,Vacanti, JP,et al. Transplantation of chondrocytes utilizing a polymer-cell construct to produce tissue engineered cartilage in the shape of a human ear. Plast Reconstr Surg,1997,100(2):297-302.
14. Yang CM. Basic And Chinical Research on Tissue Engineering.Sichuan Science Press，2000,
15. Cao YL, et al. Replantation of avulsion of the scalp. Chinese J Microsurgery,1991,14(4) :223.
16. Liu Wei, et al. Inhibiting scar formation in rat cutaneous wounds by blocking TGF-βsignaling. Natl Med J China,2003,83(1).
The 9th Peoples Hospital, Shanghai 210000,China
(Editor Shang Zhi-wei)(ZHANG Di-sheng，ZHOU Yi-qu)