Exploiting potency of negative pressure in wound dressing using limited access dressing and suction-assisted dressing

Role of negative pressure dressing and moist wound healing are well established in the treatment of both acute and chronic wounds with certain advantages and disadvantages in both the techniques. Both these techniques prevents wound colonization, but the negative pressure dressing method has proved to have a greater potency to remove secretions, prevent wound invasion and eradication established infection. In both these techniques there is no accessibility to wound environment. Limited access dressing (LAD) is a moist wound dressing with negative pressure. It provides limited access to the wound through two small ports for both dressers and pathogens. The LAD design has notable advantages like wound isolation that reduces chance of wound colonization and safe disposal of infected materials (important factor to reduce hospital-acquired infections), while avoiding some major disadvantages such as opacity of dressing materials, inaccessible offensive smelling wound environment, and relatively high treatment costs. In LAD a definite intermittent negative pressure regimen is followed. The intermittent negative pressure (cycle of 30 minutes suction and 3½ hours rest) is effective. Overall, the LAD is a safe and effective alternative to conventional dressing methods. LAD is an excellent research tool for wound healing as frequent/continuous record of wound healing is possible without disturbing the wound healing process. LAD is an effective dressing for limb salvage in cases of acute and chronic complex wounds. Leech effect prevents wound related systematic response syndrome and sepsis. Suction-assisted dressing (SAD) is a combination of semiocclusive dressing with negative pressure. It works by removal of fluids by intermittent (like LAD) negative pressure and preventing bacterial invasion. SAD is especially advantageous where soakage is less, there is no dead tissue covering the wound (e.g., following skin grafting), superficial skin wounds (e.g., donor area) and also where LAD is technically difficult to apply over circumferential trunk and neck dressings under anesthesia.KEY WORDS: Limited access dressing, negative pressure wound therapy, suction-assisted dressing     

A liposome hydrogel with polyvinyl-pyrrolidone iodine in the local treatment of partial-thickness burn wounds

Local treatment of burn injuries with conventional anti-infective preparations does not provide the moist environment that promotes fast wound healing. In a randomized controlled trial the effects of liposome polyvinyl-pyrrolidone-iodine (PVP-I) hydrogel, a novel formulation of PVP-I in a liposome hydrogel with high water-binding capacity, were investigated in 43 patients with partial-thickness burn wounds in an intraindividual comparison with a conventional silver-sulfadiazine cream. Treatment with liposome PVP-I hydrogel resulted in significantly faster complete healing of the burn wounds compared with silver-sulfadiazine cream (9.9 +/- 4.5 days versus 11.3 +/- 4.9; P < 0.015). The cosmetic result (smoothness, elasticity, appearance) was rated as excellent for 37.0% of study wounds with liposome PVP-I hydrogel compared with 13.0% of wounds treated with silver-sulfadiazine cream. Local tolerability was good; handling and change of dressing were rated as easy. Local treatment with liposome PVP-I hydrogel thus provides fast wound healing with a favorable cosmetic result.     

Evaluation of a bi-layer wound dressing for burn care I. Cooling and wound healing properties

Severe burns remain a significant cause of morbidity and mortality despite the availability of numerous therapies. We assessed the wound healing and skin-cooling properties of a DRDC hydrogel/polyurethane wound dressing using different pre-clinical models. Our results show that 85% of partial-thickness, non-contaminated porcine wounds treated with our dressing healed within 6 days. In contrast, 85% of the wounds treated with commercial dressings healed within 8 days. Application of a moist DRDC dressing (to simulate a condition of exudate absorption) on a scald burn covering 25% of the dorsal area in rats reduced skin temperature by 1.70 +/- 0.14 degrees C for 5 min, the skin temperature being comparable to that of control burned rats after 20 min. The application of a moist DRDC dressing did not induce significant differences in body temperatures compared with that of burned animals without dressing coverage throughout the 90-min experiment. While no change in body temperatures were observed when standard dressings (i.e., not pre-moistened) were applied, skin temperature increased gradually. These data show that our dressing is effective in promoting faster healing of the treated wound; and providing a transient, but beneficial cooling effect to the skin contact-site, without the adverse effect of inducing whole-body hypothermia.     

NF-κB and COX-2 repression with topical application of hesperidin and naringin hydrogels augments repair and regeneration of deep dermal wounds

IntroductionWound injury is common and causes serious complications if not treated properly. The moist dressing heals wounds faster than other dressings. Therefore, we sought to study the effect of hesperidin/naringin hydrogel wound dressing or their combinations on the deep dermal wounds in mice.MethodsA rectangular full thickness skin flap of 2.5 × 1.5 cm was excised from depilated mice dorsum and the wound was fully covered with 5% hesperidin/5% naringin hydrogel or both in the ratio of 1:1, 2:1, or 1:2, respectively once daily until complete healing of the wound. Data were collected on wound contraction, mean wound healing time, collagen, DNA, and nitric oxide syntheses, glutathione concentration, superoxide dismutase activity, and lipid peroxidation throughout healing. Expression of NF-κB and COX-2 were also estimated in the regenerating granulation tissue using Western blot.FindingsDressing of wounds with 5% hesperidin hydrogel led to a higher and early wound contraction and significantly reduced mean wound healing time by 5.7 days than 5% naringin or combination of hesperidin and naringin hydrogels in the ratio of 1:1, 2:1, or 1:2. Hesperidin hydrogel wound dressing caused higher collagen and DNA syntheses than other groups at all times after injury. Glutathione concentration and superoxide dismutase activity increased followed by a decline in lipid peroxidation in regenerating wounds after hesperidin/naringin hydrogel application and a maximum effect was observed for hesperidin alone. The hesperidin/naringin hydrogel suppressed NF-κB and COX-2 expression on days 6 and 12.ConclusionsApplication of 5% hesperidin hydrogel was more effective than 5% naringin or combination of hesperidin and naringin gels (1:1, 2:1 or 1:2) indicated by a greater wound contraction, reduced mean wound healing time, elevated collagen and DNA syntheses, rise in glutathione concentration, and superoxide dismutase activity followed by reduced lipid peroxidation, and NF-κB, and COX-2 expression.     

The effect of moist and moist exposed dressings on healing and barrier function restoration of partial thickness wounds

Improved healing of full- and partial-thickness cutaneous wounds in wet and moist environments is due primarily to retention of biological fluids over the wound preventing desiccation of denuded dermis or deeper tissues. This also allows faster and unimpeded migration of keratinocytes over the wound surface and enables the naturally occurring cytokines and growth factors to exert their beneficial effect on wound contracture and reepithelialization. Despite all these documented benefits creating and maintaining a sealed moist environment over large surface areas such as large skin graft donor sites or extensive burns is technically difficult if not impossible. The preliminary investigation carried out between 1999 and 2000 studied the healing of a split-thickness skin graft (STSG) following application of moist exposed burn ointment (MEBO). This compound provides a moist environment without the need of an overlying occlusive dressing, and compares favorably with Sofra-Tulle semi-open dressing. Healing of STSG donor sites was then evaluated from January to September 2001 in a prospective study comparing the effect of Tegaderm, a semipermeable membrane occlusive dressing, and MEBO, two different types of moist dressings. Wound healing was evaluated by measuring transepidermal water loss (TEWL), and scar quality was assessed by two independent observers using a visual analogue scale. Faster healing was observed clinically with MEBO application. Physiological healing as determined by TEWL measurements occurred at an extremely significant earlier stage for MEBO, and this was associated with better scar quality demonstrating a positive relationship between function and cosmetic appearance. Moreover, simple ointment application was definitely more practical than application of the occlusive self-adhesive membrane.     

Enhanced healing of mitomycin C‐treated healing‐impaired wounds in rats with hydrosheets composed of chitin/chitosan,fucoidan, and alginate as wound dressings

To create a moist environment for rapid wound healing, a hydrosheet composed of alginate, chitin/chitosan, and fucoidan (ACF‐HS) has been developed as a functional wound dressing. The aim of this study was to evaluate the accelerating effect of ACF‐HS on wound healing for rat mitomycin C‐treated healing‐impaired wounds. Full‐thickness skin defects were made on the back of rats and mitomycin C was applied onto the wound for 10 minutes to prepare a healing‐impaired wound. After thoroughly washing out the mitomycin C, ACF‐HS was applied to the healing‐impaired wounds. The rats were later euthanized and histological sections of the wounds were prepared. The histological examinations showed significantly advanced granulation tissue and capillary formations in the healing‐impaired wounds treated with ACF‐HS on days 7 and 14, in comparison with that in alginate fiber (Kaltostat^®), hydrogel wound dressing (DuoACTIVE^®), and nontreatment (negative control). Furthermore, in cell culture studies, ACF‐HS‐absorbed serum and fibroblast growth factor‐2 was found to be proliferative for fibroblasts and endothelial cells, respectively, and ACF‐HS‐absorbed serum was found to be chemoattractive for fibroblasts. However, our results may not be strictly comparable with general healing‐impaired wound models in humans because of the cell damage by mitomycin C. In addition, more biocompatibility studies of fucoidan are essential due to the possibility of renal toxicity.     

Biodegradable hydrogel‐based biomaterials with high absorbent properties for non‐adherent wound dressing

Dressing materials involve conventional gauzes and modern materials such as hydrogels and foam‐based biomaterials. Although the choice of dressing material depends on the type of wound, a dressing material is expected to be non‐cytotoxic. Additionally, moist dressing is considered appropriate to accelerate epithelialisation, while dry dressing may cause tissue damage during removal. An ideal dressing material is expected to provide a moist environment and degrade and release the drug for faster wound healing. Thus, we have designed a hydrogel‐based biodegradable dressing material to provide the moist environment with no cytotoxic effect in vitro. The design of the hydrogel involved alginate–collagen reinforced with whisker cellulose derived from cotton. The hydrogel was prepared via amide linkage in the presence of 1‐ethyl‐(dimethylaminopropyl) carbodiimide (EDC) and N‐hydroxysulfosuccinimide (NHS), followed by divalent cationic cross‐linking of alginate and hydrogen bonding with cellulose. The high water retention capability of the hydrogel enables a moist environment to be maintained in the wounded area. The constituents of the hydrogel provided a microenvironment that was suitable for cell proliferation in the vicinity of the hydrogel but inhibited cell attachment on it. The MTT assay results indicated a higher fibroblast proliferation and viability in the presence of the hydrogel.     

Development of a PHMB hydrogel‐modified wound scaffold dressing with antibacterial activity

Current wound scaffold dressing constructs can facilitate wound healing but do not exhibit antibacterial activity, resulting in high infection rates. We aimed to endow wound scaffold dressing with anti‐infective ability by polyhexamethylenebiguanide (PHMB). We prepared PHMB hydrogel at varying concentrations (0.25%, 0.5%, 1%, 2%) and assessed release and cytotoxicity. PHMB hydrogel was added to the wound scaffold dressing to generate a PHMB hydrogel‐modified wound scaffold dressing. Wound healing and infection prevention were evaluated using a full‐thickness skin defect model in rats. In vitro, the hydrogel PHMB release time positively correlated with PHMB concentration, with 1% allowing sufficiently long release time to encompass the high‐incidence period (3‐5 days) of infection following wound scaffold dressing implantation. Implantation of 1% PHMB hydrogel into the skin did not cause adverse responses. in vitro cytotoxicity assays showed the PHMB hydrogel‐modified wound scaffold dressing did not significantly affect proliferation of fibroblasts or vascular endothelial cells, 99.90% vs 99.84% for fibroblasts and 100.21% vs 99.28% for vascular endothelial cells at 21 days. Transplantation of PHMB hydrogel‐modified wound scaffold dressing/unmodified wound scaffold dressing on the non‐infected wounds of rats yielded no significant difference in relative vascularization rate, 47.40 vs 50.87 per view at 21 days, whereas bacterial content of the wound tissue in the PHMB hydrogel‐modified wound scaffold dressing group was significantly lower than the unmodified wound scaffold dressing group, (1.80 ± 0.35) × 10³ vs (9.34 ± 0.45) × 10³ at 14 days. Prevalence of persistent wound infection in the rats receiving PHMB hydrogel‐modified wound scaffold dressing transplantation onto infected wounds was significantly lower than the unmodified wound scaffold dressing group, 30% vs 100%. PHMB hydrogel‐modified wound scaffold dressing exhibited suitable antibacterial ability, and its biological activity did not significantly differ from that of the unmodified wound scaffold dressing, thereby allowing it to effectively prevent infection following wound scaffold dressing implantation.     

Clinical evaluation of hydrocolloidal dressing in 147 patients undergoing cardiovascular surgery

Recent evidence has suggested that a moist environment plays an important role in wound healing. Karayahesive, one type of hydrocolloidal dressing, contains natural karaya gum as a hydrophilic gel. We applied hydrocolloidal dressing to operative wounds in 147 patients who underwent cardiovascular surgery from April 2001 through August 2002 to evaluate its clinical usefulness. The dressing was kept on the wounds for 7 days after operation, but was immediately switched to conventional dressing with gauze if there was any problem. A total of 144 patients (98%) had no wound chest infections. Good wound healing was obtained with only 1 dressing, removed 7 days after operation, in 128 patients (87%). In 19 patients (13%), the hydrocolloidal dressing was switched to conventional dressing. In 13 of these patients the hydrocolloidal dressing dissolved naturally or exudation occurred; clinically, there were no local problems; however, 3 patients had infection, 2 had fat necrosis, and 1 had burn injury caused by electrocautery. No patients had skin problems caused by this dressing. We conclude that hydrocolloidal dressing can be used safely and effectively in patients undergoing cardiovascular surgery and reduce the workload of healthcare workers.     

Recent advances in topical wound care

There are a wide variety of dressing techniques and materials available for management of both acute wounds and chronic non-healing wounds. The primary objective in both the cases is to achieve a healed closed wound. However, in a chronic wound the dressing may be required for preparing the wound bed for further operative procedures such as skin grafting. An ideal dressing material should not only accelerate wound healing but also reduce loss of protein, electrolytes and fluid from the wound, and help to minimize pain and infection. The present dictum is to promote the concept of moist wound healing. This is in sharp contrast to the earlier practice of exposure method of wound management wherein the wound was allowed to dry. It can be quite a challenge for any physician to choose an appropriate dressing material when faced with a wound. Since wound care is undergoing a constant change and new products are being introduced into the market frequently, one needs to keep abreast of their effect on wound healing. This article emphasizes on the importance of assessment of the wound bed, the amount of drainage, depth of damage, presence of infection and location of wound. These characteristics will help any clinician decide on which product to use and where,in order to get optimal wound healing. However, there are no ‘magical dressings’. Dressings are one important aspect that promotes wound healing apart from treating the underlying cause and other supportive measures like nutrition and systemic antibiotics need to be given equal attention.KEY WORDS: Moist healing, topical wound care, wet dressings     

A polyurethane dressing is beneficial for split-thickness skin-graft donor wound healing

Few comparative studies have been performed on the various wound-dressing materials or methods proposed for use. To clarify the efficacy of wound dressing, 35 patients (17 females, aged 44.8+/-26.86 years and 18 males, aged 35.4+/-29.70) were subjected to a prospective study comparing a polyurethane dressing and a hydrogel dressing for split-thickness skin donors from the lateral thighs. We examined their clinical usefulness such as accelerated healing time, frequency of changing the dressing, degree of pain, or amount of exudates, and performed moisture meter analysis at 1 month and 1 year after re-epithelialization, which reflects the quality of the stratum corneum and subsequent scarring. The polyurethane dressing was superior to hydrogel in the wound healing time, amount of exudates, and frequency of dressing changes: the hydrogel was better for regulating the degree of pain. There was a positive correlation between transepidermal water loss and the effective contact coefficient, which indicates skin barrier function and affected by skin surface electrolytes and reflects water content, in moisture meter analysis (r(2)=0.32, p<0.01). Transepidermal water loss returned to the control level at 1 year after healing with both dressings. The effective contact coefficient of the polyurethane wound was significantly lower than that of hydrogel at 1 month (p<0.01), while both dressing wounds demonstrated significantly higher values at both 1 month and 1 year compared to the control (p<0.01). The polyurethane dressing is therefore superior both clinically and in moisture meter analysis.     

Scar Quality and Physiologic Barrier Function Restoration After Moist and Moist-Exposed Dressings of Partial-Thickness Wounds

BACKGROUND: There is growing evidence of improved healing of full- and partial-thickness cutaneous wounds in wet and moist environments. Retention of biologic fluids over the wound prevents desiccation of denuded dermis or deeper tissues and allows faster and unimpeded migration of keratinocytes over the wound surface. It allows also the naturally occurring cytokines and growth factors to exert their beneficial effect on wound contracture and re-epithelialization. Despite all of these documented benefits, applying the moist healing principles to large surface areas, in particular to large burns, is hindered by the major technical handicap of creating and maintaining a sealed moist environment over these areas. METHODS: From January to September 2001, healing of partial-thickness skin graft donor sites was studied in a prospective comparative study of two types of moist dressings, Tegaderm (3M Health Care, St. Paul, MN), a semipermeable membrane occlusive dressing, and moist exposed burn ointment (MEBO) (Julphar; Gulf Pharmaceutical Industries, United Arab of Emirates), an ointment that can provide a moist environment without the need of an overlying occlusive dressing. Healing was assessed both clinically and with serial measurements of transepidermal water loss (TEWL) and moisture. Following healing, scar quality was evaluated by two members of the team separately using a visual analog scale. Results were statistically analyzed. RESULTS: Faster healing was observed clinically with MEBO application. Physiologic healing as determined by TEWL measurements occurred at an extremely significant earlier stage for MEBO, and this was associated with better scar quality, demonstrating a positive relationship between function and cosmetic appearance. Moreover, the ointment is definitely easier to apply than the occlusive self-adhesive membrane, which requires some degree of dexterity and expertise. CONCLUSION: MEBO application is an effective and valid alternative to conventional occlusive dressings. Moreover, the observed improved anatomic and physiologic healing indicates that MEBO may have a positive effect on healing more that the mere fact of passive moisture retention.     

乳猪皮生物敷料对创面愈合的影响

目的:探讨乳猪皮生物敷料促进创面愈合的机理。方法:用凡士林纱布做对照,将乳猪皮生物敷料覆盖猪皮肤缺损创面,观察创面面积、愈合时间、炎性反应及肉芽生长等组织学改变。结果:乳猪皮生物敷料较对照组凡士林纱布能加速创面愈合(P<0.01),减少炎性细胞浸润和肉芽生长。结论:乳猪皮生物敷料促进创面愈合并提高愈合的质量,并可在常温下较长时间保存,是创面修复的一种较理想的生物敷料。     

Effects of nitric oxide releasing poly(vinyl alcohol) hydrogel dressings on dermal wound healing in diabetic mice

Healing of chronic wounds such as diabetic foot ulcers is a significant clinical problem. Methods of accelerating healing in these difficult lower extremity sites include use of growth factor-loaded gels, hyperbaric oxygen, grafts, and artificial skin replacements. Nitric oxide (NO) has been proposed as a possible active agent for enhancing wound healing. This study examines the in vitro and in vivo responses to a novel hydrogel that produces therapeutic levels of NO. A hydrogel wound dressing was fabricated using ultraviolet light-initiated polymerization from poly(vinyl alcohol) with a NO donor covalently coupled to the polymer backbone. NO release from the NO-modified hydrogel was shown to occur over a time period of up to 48 hours, and there was no associated decrease in fibroblast growth or viability in vitro associated with NO hydrogels. Fibroblasts in culture with NO hydrogels had an increased production of extracellular matrix compared with cells cultured without the NO hydrogels. Preliminary animal studies in a diabetic mouse, impaired wound healing model were conducted comparing low (0.5 mM) and high (5 mM) doses of NO. Time to complete closure was similar in control wounds and NO-treated wounds; however, at 8 days control wounds were significantly smaller than NO-treated wounds. By days 10 to 13 this delay was no longer apparent. Granulation tissue thickness within the wounds at days 8 and 15 and scar tissue thickness after wound closure were increased in animals exposed to higher dose NO hydrogels. The results of this study suggest that exogenous NO released from a hydrogel wound dressing has potential to modulate wound healing.     

An evidence‐based review of split‐thickness skin graft donor site dressings

This evidence‐based review aimed to identify and evaluate current existing evidence relating to the efficacy of dressing materials for spit‐thickness skin graft donor site wounds in relation to promoting rapid healing and reducing patient pain. A comprehensive systematic search of the literature between 2006 and 2016 identified 35 publications that were included in the review.Based on the results of the review, it was found that moist wound‐healing products have a clear advantage over non‐moist products in the reduction of pain and increased healing rates. This review concluded that moist wound‐healing products are more effective than non‐moist wound‐healing products in reducing pain and promoting healing in split‐thickness skin graft donor site wounds. A recommendation based on this review is that further research examine the role of secondary dressing usage in donor site wound management, and the consideration of using more than one primary dressing product during the donor site wound‐healing process should be undertaken.     

Taking the trauma out of wound care: the importance of undisturbed healing

Significant advances in wound dressing technology have resulted in a myriad of dressing choices for wound-care clinicians, providing more than just an inert wound cover. The establishment of a moist wound environment under modern wound dressings and the optimisation of the healing response are now the goals expected of these dressings. However, the use of wound dressings, particularly traditional dressings such as gauze, frequently results in wound and peri-wound tissue damage that impairs the wound healing response, counteracting any of the dressings' healing benefits. Therefore, in order to maximise the healing benefits wounds covered by today's wound dressings must minimise tissue disturbance (physical as well as chemical). This review aims to consider the ways traditional, as well as modern, wound dressings may disturb wounds, summarising the potential areas of wound disturbance, and suggesting how best to address this aspect of the use of wound dressings to treat acute as well as chronic wounds.     

重组人表皮生长因子凝胶（易孚）在压疮创面床准备中的临床观察

目的：探讨重组人表皮生长因子（rhEGF）凝胶（易孚）在手术修复复杂压疮（Ⅲ期与IV期）前期创面床准备阶段的疗效。方法：将80例压疮患者随机分为治疗组及对照组,各组40例,在常规清创及生理盐水冲洗创面后,治疗组将重组人表皮生长因子凝胶（易孚）置于湿纱布上;对照组用碘伏纱布湿敷创面,换药均为1次/天。观察创面床改善情况。结果：实验组的创面床改善时间与手术后恢复时间较对照组明显缩短,差异有显著性。结论：重组人表皮生长因子凝胶（易孚）在复杂压疮创面床准备阶段疗效显著,可促进肉芽组织生长,炎症消失,有利于创面的内源性愈合并增加后续治疗的有效性。     

重组人粒细胞/巨噬细胞集落刺激因子联合水凝胶敷料治疗深Ⅱ度烧伤创面临床观察

目的:观察外用重组人粒细胞/巨噬细胞集落刺激因子(rhGM-CSF)联合水凝胶敷料治疗深Ⅱ度烧伤创面的临床效果.方法:选择四肢部位有深Ⅱ度烧伤创面的住院患者24例,48处研究创面,每例患者2个创面,分别位于不同肢体.研究分为4组.随机选取12例患者,每例患者随机选取一个创面作为rhGM-CSF联合外用水凝胶敷料治疗组(联合治疗组,创面清创后外涂外用重组人粒细胞巨噬细胞刺激因子凝胶,覆盖医用水凝胶敷料),另一个创面作为rhGM-CSF联合外用凡士林油纱治疗组(rhGM-CSF对照组,创面清创后外涂外用重组人粒细胞巨噬细胞刺激因子凝胶,覆盖凡士林油纱);余12例患者每例随机选择一处创面作为水凝胶敷料治疗组(水凝胶对照组,创面直接覆盖医用水凝胶敷料);另一处创面作为凡士林油纱对照组(凡上林对照组,创面直接覆盖凡士林油纱).每组12处创面.观察各组创面愈合时间及创面感染情况,创面分泌物行细菌培养,比较创面细菌感染阳性率.结果:联合治疗组创面愈合时间较其他3组明显缩短(P＜0.05);rhGM-CSF对照组和水凝胶对照组创面愈合时间较凡士林对照组缩短(P＜0.05).rhGM-CSF联合外用水凝胶敷料治疗组创面洁净,细菌检出率低(16.7％):rhGM-CSF治疗组感染状况也较轻,细菌检出率较低(25.0％),凡士林对照组感染状况重,细菌检出率最高(83.3％,P＜0.01).结论:深Ⅱ度烧伤创面外用rhGM-CSF联合水凝胶敷料治疗,可以明显减少创面细菌感染概率,缩短创面愈合时间.     

密闭液性环境干燥环境下供皮区创面愈合的比较研究

目的比较研究密闭液性环境和干燥环境下供皮区创面的愈合过程. 方法 1996年7月～1997年3月以13例成人断层供皮区创面为研究对象,其中男9例,女4例,年龄20～50岁,创面面积(100～400) cm2,取皮深度中厚,约0.44 mm.同一个创面分为实验组(密闭液性环境)和对照组(干燥环境),采用自身对照法.应用大体、组织学及电镜观察等方法进行观察. 结果密闭液性环境下创面愈合较快,创面组织中成纤维细胞较早活跃、且持续时间较长,再血管化和再上皮化均较早和较快发生. 结论密闭液性环境下创面愈合较快,与组织修复细胞较为活跃、再血管化和再上皮化较快发生有关.