[Clinical effects of negative pressure wound therapy in treating the poor healing of incisions after different abdominal operations].

Objective: To investigate the clinical effects of negative pressure wound therapy (NPWT) in treating the poor healing of incisions after different abdominal operations. Methods: The retrospective observational study was conducted. From June 2019 to December 2020, 42 patients with poor healing of incisions after abdominal surgery were admitted to Center of Burns and Trauma of the First Affiliated Hospital of Naval Medical University, including 29 males and 13 females, aged 23-81 years. The disease course of poor healing of abdominal incision was 3-60 d. The preoperative examination of patients was completed after admission, and NPWT was used after debridement. According to the dehiscence level of incision, the negative pressure value of -10.64 to -6.65 kPa was set. The incisions were sutured in the second stage when the incisions had good blood circulation. The cause of abdominal surgery, the dehiscence level and the cause of poor healing of abdominal incision were investigated, and the final healing of abdominal incision and the occurrence of complication were observed. Results: The causes of abdominal operations in this group of patients who ocurred poor healing of abdominal incisions were ranked according to the composition ratio, with the top 4 causes being colon cancer (9 cases, accounting for 21.4%), bile duct disease (8 cases, accounting for 19.0%), liver cancer (5 cases, accounting for 11.9%), and appendicitis (4 cases, accounting for 9.5%). There were 25 cases (59.5%) with dehiscence of abdominal incision in the deep fascia layer, and the other 17 cases (40.5%) with dehiscence of abdominal incision in the superficial fascia layer. The causes of poor healing of abdominal incision were ranked according to the composition ratio, with the top 3 causes being infection (24 cases, accounting for 57.1%), fat liquefaction (11 cases, accounting for 26.2%), and suture reaction (5 cases, accounting for 11.9%). The blood circulation in 40 patients was improved after being treated with NPWT, and the incisions were sutured in the second stage. The incisions healed well when the suture lines were removed in the second to third week. Intestinal fistula and bile leakage developed during the NPWT treatment, respectively in the other 2 patients, in which negative pressure equipment was removed subsequently, and the incisions healed after adequate drainage and conventional dressing changes. Conclusions: NPWT is effective in treating poor healing of abdominal incision after different abdominal surgeries. The clinicians need to comprehensively assess the patient's condition to determine when and how to use NPWT to avoid the occurrence of intestinal fistula, bile leakage, and other complications.

[Debridement combined with vacuum sealing drainage in the treatment of severe infection in abdominal wall due to allogeneic umbilical cord embedded in abdominal wall for immunotherapy].

Objective: To explore the effect of debridement combined with vacuum sealing drainage (VSD) on the treatment of severe infection in abdominal wall due to allogeneic umbilical cord embedded in abdominal wall for immunotherapy. Methods: From January 2015 to December 2016, 12 patients with severe infection in abdominal wall due to allogeneic umbilical cord embedded in abdominal wall for immunotherapy were admitted to our department. They were conducted with systemic anti-infective treatment, local debridement, and VSD. The wounds were continuously washed for 3 to 5 days after the VSD device installed, with negative pressure value from -16.0 to -12.0 kPa. The VSD device was removed 5 to 7 days later. Continue wound dressing by aseptic ribbon gauze was stuffed in the cavity, and the incision was sutured after the granulation tissue grew well in the cavity. Results: In all patients, allogeneic umbilical cords were completely removed and abdominal infection was cured. The wounds healed well, the sensory function of abdominal was normal, and the activity was not restricted. All the patients were followed up for 3 to 6 months with no reinfection or incisional hernia. Conclusions: Embeding the whole allogeneic umbilical cord in abdominal wall for immunotherapy can lead to severe infection in abdominal wall. Abdominal infection can be cured by debridement combined with VSD with good clinical results.

Inhibition of activin receptor-like kinase 5 induces matrix metallopeptidase 9 expression and aggravates lipopolysaccharide-induced pulmonary injury in mice.

BACKGROUND: TGF-ß (Transforming Growth Factor-ß) mediates its biological effects through members of activin receptor-like kinase (ALK) family and TGF-ß/Smad3 signaling link inflammation to pulmonary fibrosis. AIM: The aim of this study was to evaluate the role of SB431542 as a specific inhibitor of Activin receptor-Like Kinase 5 (ALK5) in pneumonic injury. MATERIALS AND METHODS: Anesthetized and endo-tracheally intubated C57BL/6 mice were randomized to three groups: the control group with intra-tracheal instillation of 1.5 mg/kg normal saline (NS); LPS stimulation group with intra-tracheal instillation of 3 mg/kg LPS (lipopolysaccharide); and LPS+SB431542 group with intra-peritoneal (i.p.) injection of 4.2 mg/kg SB431542 1 h before intra-tracheal instillation of 3 mg/kg LPS. The lung tissue was obtained 6 h after injury, and the degree of pulmonary injury was evaluated by pathologic scoring. The lung wet/dry weight ratio was measured. TNF-α, IL-1ß, and MMP-9 (matrix metallopeptidase-9) mRNA expression levels were assayed by real time PCR (polymerase chain reaction). The content of MMP-9 total protein was measured by Western blotting. The content of active MMP-9 was detected by gelatin zymography. Location of MMP-9 in mouse lung tissue was monitored by immunohistochemistry. RESULTS: The results showed that (1) pathologic changes including interstitial pulmonary edema, neutrophil infiltration, alveolar edema and hemorrhage were observed 6 h after LPS instillation. The lung wet/dry weight rate and pathologic scores confirmed that SB431542 administration aggravated LPS injury to the mouse lung; (2) the amount of TNF-α and IL-1ß mRNA expression in LPS groups was significantly higher than that in the control group, and the highest in LPS+SB431542 group; (3) the amount of MMP-9 mRNA and MMP-9 protein expression and active MMP-9 in the lung tissue of LPS groups was significantly higher than that in the control group 6 h after injury, and the highest in LPS+SB431542 group; and (4) MMP-9 expression was mainly observed in the airway epithelial cells, vascular smooth muscle cells and cytoplasm of inflammatory cells as shown by immunohistochemistry, and brownish yellow uniformed stained areas were also seen in the exudate from part of the alveoli. CONCLUSIONS: These results indicate that blocking the activity of TGF-ß/Smad pathway by specific inhibitor SB431542 of ALK5 promoted the releaser of large amounts of TNF-α, IL-1ß and other pro-inflammatory cytokines from the lung tissue of mice sustaining acute lung injury (ALI). At the same time, the amount and activity of MMP-9 expression in the lung were increased, and MMP-9 expression was mainly located in the airway epithelial cells, vascular smooth muscle cells and inflammatory cells, causing increased permeability of the pulmonary blood vessels, degradation of the extracellular matrix and destruction of the normal lung tissue structures, which directly or indirectly promotes the progression of pulmonary inflammatory responses and aggravates ALI.

The role of pores in acellular dermal matrix substitute.

To promote the engraftment rate of autologous skin combined with acellular dermal matrix (ADM), ADM was punched to produce regular pores from 500 to 800 µm in diameter, separated by a distance of 3 to 5 mm. The porous ADM was then implanted beneath the flap and transplanted onto an open full-thickness defect wound combined with autografts about 0.2 mm thick in a rat model. The change in diameter of pores in ADM and the neovascularization of ADM matrix were evaluated, and the take rate of porous ADM combined with overlying autologous skin was compared with that of non-porous ADM. The results showed that when porous ADM was grafted onto the full-thickness skin excised wound, plasma penetrated from the wound bed to the surface of ADM through these pores, i.e. the pores punched on ADM were responsible for the imbibition function. Subdermal implantation of ADM indicated that one week post-operation the pores in ADM were still detectable, and some of them contained red blood cells. Two to three weeks after grafting the pores became smaller, partly because of newly synthesized collagen matrix deposition. In Sprague-Dawley rats the engraftment rate of autologous sheet skin graft placed over ADM with pores was 89.5%, which was significantly higher than ADM without pores (63.2%). It is concluded that porous ADM could serve as a good dermal substitute.

Transplantation of Composite Skin Containing Keratinocytes Cultured on a Fibroblast-conditioned Acellular Dermal Matrix.

To evaluate the role of fibroblasts in composite skin reconstructed in vitro, four different types of composite skin (A, B, C, and D) were prepared. Human keratinocytes were seeded onto the epidermal side of an acellular dermal matrix (ADM) in type A. Keratinocytes were seeded onto the epidermal side of an ADM and human fibroblasts onto the dermal side in type B. Both keratinocytes and fibroblasts were seeded onto the epidermal side in type C. Type D consisted of fibroblasts on both sides of the ADM and keratinocytes on the epidermal side. The adherence of keratinocytes to the ADM was observed. The composite skin was then transplanted onto full-thickness skin defect wounds in nude mice. Results showed that the adherence of keratinocytes to the ADM was improved when fibroblasts were pre-seeded onto the epidermal side of the ADM. The composite skin was able to close full-thickness skin defect wounds. The take rates were respectively 44.1 ± 7.8%, 47.3 ± 5.4%, 75.2 ± 8.8%, and 81.2 ± 8.1% for types A, B, C, and D. The take rates of types C and D were significantly higher than those of types A and D. There was no significant difference in take rate between types C and D. In conclusion, composite skin consisting of keratinocytes cultured on a fibroblast-conditioned ADM was a good skin substitute.