Application of Traditional Chinese Medicines in Postoperative Abdominal Adhesion

Effects of linalool on postoperative peritoneal adhesions in rats

The current study examines the effects of linalool in preventing postoperative abdominal adhesions. Twenty male Wistar rats were randomly divided into four groups. (1) Sham: in this group, the abdomen was approached, and without any manipulations, it was sutured. (2) Control: rats in this group underwent a surgical procedure to induce adhesions. This involved making three incisions on the right abdominal side and removing a 1×1-cm piece of the peritoneum on the left abdominal side. (3) Treatment groups: these groups underwent the same surgical procedure as the control group to induce adhesions. Animals in these groups received linalool orally with doses of 50 and 100 mg/kg, respectively, for a period of 14 days. Moreover, rats in the sham and control groups received normal saline via gavage for 14 days. The evaluation of TNF-α, TGF-β, VEGF, and caspase 3 was performed using western blot and IHC methods. Furthermore, oxidative stress biomarkers such as MDA, TAC, GSH, and NO were assessed in the peritoneal adhesion tissue. The findings revealed that linalool significantly reduced peritoneal adhesions by reducing TNF-α, TGF-β, VEGF, and caspase 3 levels. Moreover, MDA concentration was significantly decreased, while NO, TAC, and GSH levels were notably increased. Overall, linalool was effective in preventing adhesion formation and reduced inflammation, angiogenesis, apoptosis, and oxidative stress. Therefore, linalool as a potent antioxidant is suggested for reducing postoperative adhesions in rats.

Inhibition of chemokine receptor CXCR2 attenuates postoperative peritoneal adhesion formation

BACKGROUND

Postoperative peritoneal adhesions remain a problem after general and gynecological surgery.

METHODS

Hematoxylin and eosin and Masson's trichrome staining of ischemic buttons were performed 6, 12, 24 hours, and 7 days after button induction. Scanning electron microscopy, ribonucleic acid sequencing, quantitative real-time polymerase chain reaction, immunohistochemical staining, and flow cytometry were used to elucidate the pathophysiology of postoperative peritoneal adhesions.

RESULTS

The results showed that thickening of the peritoneum and abscission of mesothelial cells and collagen fibers increased significantly on the surface of the "button" in the control groups at 24 hours postoperatively. Scanning electron microscopy revealed a large number of granulocytes on the button surface in the control group at 24 hours. Ribonucleic acid sequencing and quantitative real-time polymerase chain reaction also revealed that CXCR2 expression was significantly upregulated. In addition, danirixin, a CXCR2 inhibitor, reduced abdominal adhesion in the injured area by inhibiting the infiltration of inflammatory cells and collagen production. Immunohistochemical staining showed decreased expression of CXCR2 in the adhesion area 7 days after surgery in the treatment group. Flow cytometry showed a significantly decreased neutrophil ratio in the treatment group compared with that in the control group 24 hours after the operation.

CONCLUSIONS

Inflammation plays an important role in the early stages of postoperative peritoneal adhesion formation, whereas collagen fibers and angiogenesis play important roles in the late stages. The CXCL2-CXCL3-CXCR2 signaling axis is an important link in the mechanism of postoperative peritoneal adhesion formation, and the application of CXCR2 inhibitors can alleviate the formation of postoperative peritoneal adhesions.

Efficacy and Mechanisms of Silybum Marianum, Silymarin, and Silibinin on Rheumatoid Arthritis and Osteoarthritis Symptoms: A Systematic Review

BACKGROUND

Rheumatoid arthritis (RA) and osteoarthritis (OA) are the most common forms of skeletal disease worldwide.

OBJECTIVE

The current systematic review investigated the mechanisms of Silybum marianum, silymarin, and silibinin on RA and OA symptoms.

METHODS

The PRISMA 2020 statement was used for reporting Items in this systematic review. The result was a list of five databases, including Web of Science, Cochrane Library, Embase, PubMed, and Scopus. After determining the inclusion and exclusion criteria, of 437 records identified, 21 studies were eligible. The data were extracted from the studies and imported into an Excel form, and finally, the effects, outcomes, and associated mechanisms were surveyed.

RESULTS

Silybum marianum and its main constituents revealed immunomodulatory, anti-inflammatory, antioxidant, and anti-apoptotic properties in humans and laboratory animals. Moreover, they protect the joints against the cartilage matrix's hypocellularity and fibrillation, reduce synovitis, and inhibit degeneration of aggrecan and collagen-II in human chondrocytes. They also, through reducing inflammatory cytokines, show an analgesic effect. Although silymarin and silibinin have low absorption, their bioavailability can be increased with nanoparticles.

CONCLUSION

In experimental studies, Silybum marianum, silymarin, and silibinin revealed promising effects on RA and OA symptoms. However, more clinical studies are needed in this field to obtain reliable results and clinical administration of these compounds.

Research on Mechanisms of Chinese Medicines in Prevention and Treatment of Postoperative Adhesion

Postoperative adhesion (PA) is currently one of the most unpleasant complications following surgical procedures. Researchers have developed several new strategies to alleviate the formation of PA to a great extent, but so far, no single measure or treatment can meet the expectations and requirements of clinical patients needing complete PA prevention. Chinese medicine (CM) has been widely used for thousands of years based on its remarkable efficacy and indispensable advantages CM treatments are gradually being accepted by modern medicine. Therefore, this review summarizes the formating process of PA and the efficacy and action mechanism of CM treatments, including their pharmacological effects, therapeutic mechanisms and advantages in PA prevention. We aim to improve the understanding of clinicians and researchers on CM prevention in the development of PA and promote the in-depth development and industrialization process of related drugs.

Research progress of Astragalus membranaceus in treating peritoneal metastatic cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Peritoneal metastasis is a manifestation of advanced cancer often associated with a poor prognosis and poor response to treatment. Astragalus membranaceus (Fisch.) Bunge is a commonly used medicinal material in traditional Chinese medicine with various biological activities. In patients with cancer, Astragalus membranaceus has demonstrated anti-tumor effects, immune regulation, postoperative recurrence and metastasis prevention, and survival prolongation.

AIM OF THE STUDY

Peritoneal metastasis results from tumor cell and peritoneal microenvironment co-evolution. We aimed to introduce and discuss the specific mechanism of action of Astragalus membranaceus in peritoneal metastasis treatment to provide a new perspective for treatment and further research.

MATERIALS AND METHODS

We consulted reports on the anti-peritoneal metastases effects of Astragalus membranaceus from PubMed, Web of Science, China National Knowledge Infrastructure, and Wanfang databases, as well as Google Scholar. Meanwhile, we also obtained data from published medical works and doctoral and master's theses. Then, we focused on the research progress of Astragalus membranaceus in peritoneal metastatic cancer treatment. Plant names are provided in accordance with "The Plant List" (www.theplantlist.org).

RESULTS

To date, more than 200 compounds have been isolated from Astragalus membranaceus. Among them, Astragalus polysaccharides, saponins, and flavonoids are the main bioactive components, and their effects on cancer have been extensively studied. In this review, we systematically summarize the effects of Astragalus membranaceus on the peritoneal metastasis microenvironment and related mechanisms, including maintaining the integrity of peritoneal mesothelial cells, restoring the peritoneal immune microenvironment, and inhibiting the formation of tumor blood vessels, matrix metalloproteinase, and dense tumor spheroids.

CONCLUSIONS

Our analysis demonstrates that Astragalus membranaceus could be a potential therapeutic for preventing the occurrence of peritoneal metastasis. However, it might be too early to recommend its use owing to the paucity of reliable in vivo experiment, clinical data, and evidence of clinical efficacy. In addition, previous studies of Astragalus membranaceus report inconsistent and contradictory findings. Therefore, detailed in vitro, in vivo, and clinical studies on the mechanism of Astragalus membranaceus in peritoneal metastatic cancer treatment are warranted.

Piperine Liposome-Embedded in Hyaluronan Hydrogel as an Effective Platform for Prevention of Postoperative Peritoneal Adhesion

This study aimed to prepare piperine (PIP) loaded liposomes in hyaluronic acid (HA) hydrogel to provide a hybrid superstructure for postoperative adhesion prevention. Liposomes were prepared using thin-film hydration method. The optimised formulation was characterised by size, SEM, TEM, FTIR, encapsulation efficiency (EE)% (w/w), and release pattern. Liposome-in-hydrogel formulation was investigated by rheology, SEM, and release studies. The efficacy was evaluated in a rat peritoneal abrasion model. EE% (w/w) increased with increasing lipid concentration from 10 to 30; however, a higher percentage of Chol reduced EE% (w/w). The optimised liposome (EE: 68.10 ± 4.18% (w/w), average diameter: 513 ± 14.67 nm, PDI: 0.15 ± 0.04) was used for hydrogel embedding. No sign of adhesion in 5/8 rats and no collagen deposition confirmed the in vivo effectiveness of the optimised formulation. Overall, providing a sustained delivery of PIP, the developed liposome-in-hydrogel formulation can be a promising carrier to prevent postoperative adhesion.

Herbal formula Jiawei Xiaochengqi decoction prevents postoperative abdominal adhesion in a rat model through inhibition of CXCL2-CXCR2 pathway

BACKGROUND

Postoperative abdominal adhesion (PAA) is the most common complication after abdominal surgeries, which can lead to intestinal obstruction, chronic abdominal pain or female infertility. Jiawei Xiaochengqi decoction (JWXCQ) is a hospital preparation widely used for PAA treatment in Nanfang Hospital of Southern Medical University for more than twenty years.

PURPOSE

This study aimed to investigate the therapeutic effects and potential mechanism of JWXCQ against PAA and provide beneficial information for its clinical application.

METHODS

The main active components of JWXCQ were identified using ultra high performance liquid chromatography (UHPLC) combined with standard substance comparison. The efficacy and underlying mechanism of JWXCQ were evaluated through in vivo experiments with a postsurgical-induced peritoneal adhesion rat model, and in vitro studies with LPS-stimulated Raw 264.7 macrophages and primary fibroblasts. H&E and Masson staining were performed to assess histopathological changes. The levels of cytokines/proteins-associated with inflammation and degradation of extracellular matrix as well as CXCL2-CXCR2 pathway-related proteins were determined by ELISA, qRT-PCR, western blot assays or immunohistochemistry, respectively. Furthermore, siCXCR2 transfection was used to validate the mechanism of action of JWXCQ.

RESULTS

JWXCQ treatment significantly reduced the formation of PAA, inhibited the inflammation and collagen deposition, and facilitated the secretion of MMP9, decreased the levels of IL-1β, IL-6, TIMP1, COL-1, and suppressed the CXCL2-CXCR2 pathway in PAA rats. Furthermore, JWXCQ inhibited its downstream pathways, the JAK2-STAT3 and PI3K-AKT signaling, as indicated by the suppression of the phosphorylation levels of STAT3 and AKT. In vitro cell experiments revealed that JWXCQ reduced IL-1β and IL-6 secretion in Raw 264.7 macrophages and COL-1 in primary fibroblasts. The CXCL2-CXCR2, JAK2-STAT3 and PI3K-AKT pathways were also inhibited after JWXCQ treatment, which were consistent with the in vivo results. More importantly, silence of CXCR2 eliminated the regulatory effects of JWXCQ.

CONCLUSION

JWXCQ could effectively prevent the PAA formation by alleviating inflammation and collagen deposition, which was associated with the inhibition of CXCL2-CXCR2 pathway. This study investigated the relevant pharmacological mechanisms of JWXCQ, providing further evidence for the application of JWXCQ in clinical PAA treatment.

Effect of intradermal needle therapy at combined acupoints on patients’ gastrointestinal function following surgery for gastrointestinal tumors

BACKGROUND

Postoperative gastrointestinal function recovery is critical for rapid rehabilitation of patients with gastrointestinal tumors. Traditional Chinese medicine offers considerable advantages for gastrointestinal disease treatment. However, no study has reported the clinical efficacy of intradermal needle therapy (INT) at the Yuan-source, Luo-connecting, and He-sea points of the corresponding meridian for gastrointestinal function in patients following surgery for gastrointestinal tumors.

AIM

To investigate the effect of INT at combined acupoints on patients’ gastrointestinal function following surgery for gastrointestinal tumors.

METHODS

This randomized controlled trial was conducted at the Second Affiliated Hospital of Xi’an Jiaotong University on patients with diagnosed gastrointestinal cancer, no distant metastases or organ failure, and hospitalized for elective radical tumor resection, who did not receive preoperative radiotherapy or chemotherapy. Participants were randomly allocated to either the intervention (n = 32) or the control (n = 32) group. Participants in the control group received enhanced recovery care, while those in the intervention group received enhanced recovery care combined with INT at the Yuan-source, Luo-connecting, and He-sea points. After surgery, INT was performed immediately upon the patient's return to the ward, and continued for seven consecutive days. The independent samples t-test, chi-square test, and generalized estimating equations were used for data analysis.

RESULTS

The participants’ ages ranged from 40 to 80 years (average 63 ± 10.1 years). Most participants underwent surgery for either gastric (43.8%) or colon cancer (39.1%) and had adenocarcinoma (87.5%). Significant differences were noted in time to first postoperative flatus passage (66 ± 27 h vs 103 ± 41 h, P < 0.001), time to first defecation (106 ± 44 h vs 153 ± 50 h, P < 0.001), and time to first oral feeding (73 ± 30 h vs 115 ± 38 h, P < 0.001) between the intervention and control groups. Gastrointestinal symptoms, including abdominal distension, nausea, and fatigue 48 h and 72 h after surgery, were significantly alleviated in the intervention group compared with that observed in the control group (P < 0.05).

CONCLUSION

INT at the Yuan-source, Luo-connecting, and He-sea points can promote recovery of gastrointestinal function and ease gastrointestinal symptoms in patients following surgical resection of gastrointestinal tumors.

Jiuzhuan Huangjing Pills relieve mitochondrial dysfunction and attenuate high-fat diet-induced metabolic dysfunction-associated fatty liver disease

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common global chronic liver disease. Jiuzhuan Huangjing Pills (JHP) have been used for the treatment of human disease for over a thousand years, but their efficacy and underlying mechanism(s) of action against MAFLD are unknown. We investigated the alleviating effects of JHP on high-fat diet (HFD)-induced MAFLD.

METHODS

In vitro and in vivo methods were used to evaluate the effects of JHP on MAFLD. L02 adipocyte models were induced by fat emulsion and adipocytes were treated with JHP for 24 h. MAFLD rat models were induced by HFD-feeding and were intragastrically administered JHP for 12 weeks. Changes in fat accumulation, L02 cell damage, body weight, food intake, histological parameters, organ indexes, biochemical parameters, and mitochondrial indicators including ultrastructure, oxidative stress, energy metabolism, and fatty acid metabolism were investigated.

RESULTS

JHP attenuated the increase in levels of total cholesterol, triglyceride, low density lipoprotein cholesterol, alanine transaminase, and aspartate transaminase levels, and significantly increased high density lipoprotein cholesterol. JHP up-regulated levels of glutathione (GSH) and superoxide dismutase (SOD), and down-regulated malondialdehyde (MDA). JHP afforded protection to the mitochondrial ultrastructure, and inhibited the HFD-induced increase in MDA and the reduction of SOD, GSH, ATP synthase, and complex I and II, in liver mitochondria. JHP regulated the expression of β-oxidation genes, including acyl-CoA dehydrogenase, cyl-CoA dehydrogenase long chain, carnitine palmitoyltransferase 1A, carnitine palmitoyltransferase 1B, peroxisomal proliferator-activated receptor-gamma coactivator-1α and peroxide proliferator activated receptor α.

CONCLUSION

JHP alleviates HFD-induced MAFLD through the protection of mitochondrial function.

Gastrointestinal Motility and Gut Hormone Secretion in response to Shenhuang Plaster in a Postoperative Ileus Rat Model

Postoperative ileus (POI), a gastrointestinal function disorder, is a complication that arises from surgery. Shenhuang plaster (SHP) application to the Shenque acupoint (CV8) to promote the recovery of gastrointestinal function has achieved definite curative effects in clinical settings; however, the underlying pharmacological mechanism remains unknown. In this study, we evaluated the effects of SHP using a Sprague Dawley rat POI model. Then, gastrointestinal transit in different rat groups was evaluated by the movement of fluorescein-labelled dextran. Ghrelin, obestatin, motilin (MTL), and vasoactive intestinal peptide (VIP) plasma concentrations were measured via a radioimmunoassay. The expression of the ghrelin and obestatin receptors (GHS-R1α and GPR39) in the intestinal muscularis of rats in different groups was comparatively identified via western blotting. The results indicated that SHP application improved gastrointestinal motility in POI model rats. SHP application significantly increased ghrelin concentration and the expression of its receptor and inhibited obestatin concentration and the expression of its receptor in blood. Further, ghrelin concentration and the capability of gastrointestinal transit were positively correlated. Simultaneously, SHP application also promoted the secretion of other gastrointestinal motility hormones, such as MTL and VIP. Hence, these results provide evidence that SHP can promote the recovery of gastrointestinal transmission in POI rat models through regulation of ghrelin and other intestinal hormones.

Musk ketone induces apoptosis of gastric cancer cells via downregulation of sorbin and SH3 domain containing 2

Musk ketone exerts antiproliferative effects on several types of cancer, such as lung and breast cancer. However, the effects and underlying mechanisms of action of musk ketone in gastric cancer (GC) are poorly understood. The present study aimed to investigate the effects of musk ketone in GC cells. The present study indicated that musk ketone exerted significant anticancer effects on GC cells. The IC₅₀ values of musk ketone were 4.2 and 10.06 µM in AGS and HGC-27 cells, respectively. Low dosage of musk ketone significantly suppressed the proliferation and colony formation of AGS and HGC-27 cells. Cell cycle arrest and apoptosis were induced by musk ketone. Furthermore, microarray data indicated that musk ketone treatment led to downregulation of various genes, including sorbin and SH3 domain containing 2 (SORBS2). Reverse transcription-quantitative PCR and immunoblotting results indicated that musk ketone repressed mRNA and protein expression levels of SORBS2. It was also shown that knockdown of SORBS2 inhibited the proliferation and colony formation of HGC-27 cells. The antiproliferative effects of musk ketone were decreased in HGC-27 cells with SORBS2 silencing. In summary, the present study indicated that musk ketone suppressed the proliferation and growth of GC partly by downregulating SORBS2 expression.

Salvia miltiorrhiza hydroalcoholic extract inhibits postoperative peritoneal adhesions in rats

Background

One of the most prevalent postoperative complications is believed to be intra-abdominal peritoneal adhesions, which is followed by several complications. Several adhesion prevention products have been examined, yet none of them were found to be completely effective. The current research is conducted to evaluate the beneficial effects of Salvia miltiorrhiza hydroalcoholic extract in inhibiting postoperative peritoneal adhesions in rats.

Methods

Forty rats were randomly classified into five equal groups (n = 8): 1) the normal group did not undergo surgical operations, 2) the control group in which the adhesion was induced, and which did not receive any treatment, 3) distilled water group that received distilled water, and 4,5) treatment groups treated with 1 and 5% of Salvia miltiorrhiza hydroalcoholic extract. The rats were euthanized 14 days following the surgery and the macroscopic score, the microscopic score of granulomatous inflammation and granulation tissue formation, IHC markers (vimentin, CD31, IL-1β, COX-2, and iNOS), and oxidative stress biomarkers (MDA, GPx, CAT, and TAC) were assessed in the experimental groups of the study.

Results

The difference between the control group and other groups for the adhesions macroscopic score, microscopic score, IHC markers, and oxidative stress biomarkers was significant (p < 0.05). Distilled water had no protective effect on the formation of peritoneal adhesions. Salvia miltiorrhiza treatment in two different doses significantly reduced macroscopic and microscopic scores, MDA concentration, Vimentin, IL-1β, COX-2, and iNOS compared to the control group (p < 0.05). The levels of GPx, CAT, and TAC in the treatment groups increased significantly compared with the control group (p < 0.05). Our findings revealed that a higher dose of Salvia miltiorrhiza was more effective in reducing peritoneal adhesions, proinflammatory and mesenchymal cell markers, and oxidative stress.

Conclusions

Salvia miltiorrhiza extract, owing to its strong antioxidant and anti-inflammatory properties, could effectively reduce peritoneal adhesions. Therefore, Salvia miltiorrhiza is recommended to be used as an effective anti-peritoneal post-operative adhesive agent.

Facile fabrication of phospholipid-functionalized nanofiber-based barriers with enhanced anti-adhesion efficiency

Electrospun nanofibrous membranes (NFMs) have attracted considerable attention as a potential physical barrier for reducing postoperative adhesion. However, no anti-adhesion barrier can completely prevent adhesion formation. In this study, phospholipid-functionalized NFMs were readily fabricated by one-step electrospinning to obtain nanofiber-based barriers with enhanced wettability and anti-adhesion efficiency. The optimized phospholipid NFMs were shown to have a fiber diameter of 831 nm ± 135 nm that is drastically decreasing, high porosity of 87.6 % ± 1.1 %, and superior hydrophilicity. Moreover, the phospholipid NFMs with excellent cytocompatibility exhibited fibroblasts being significantly reduced (≈ 51 %) after incubation of 3 days compared to that of the NFMs (≈ 96 %), confirming long-lasting anti-adhesion capability against fibroblasts. Meanwhile, less cell adhesion and proliferation of Raw 264.7 macrophages on NFM-10Lec indicated its superior anti-inflammatory effects. Thus, the facile phospholipid-functionalized nanofibers provided a promising strategy for anti-adhesion applications.

A review: progress in preventing tissue adhesions from a biomaterial perspective

Postoperative adhesions (POA) are one of the main problems suffered by patients and are a common complaint. It is considered to be closely associated with the healing mechanism of damaged tissues. Tissue adhesions accompany other symptoms such as inflammation, pain, and even dyskinesia under certain conditions, compromising the patients' quality of life. On the other hand, common treatments involve high costs, re-surgery or long-term hospital stays. Therefore, alternative approaches need to be formulated so that aforementioned problems can be resolved. To this end, a review of recent advances in this context is imperative. In this review, we have highlighted the mechanism of adhesion formation, advances in common therapeutic approaches, and prospective treatments in preventing tissue adhesions. Based on the literature, it can be determined that the disadvantages of available commercial products in the treatment of tissue adhesion have led researchers to utilize alternative methods for designing anti-adhesive products with different structures such as electrospun fibrous mats, hydrogels, and nanospheres. These studies are on the fast track in producing optimal anti-adhesion materials. We hope that this article can attract attention by showing various mechanisms and solutions involved in adhesion problems and inspire the further development of anti-adhesion biomaterials.

Peritoneal adhesions: Occurrence, prevention and experimental models

Peritoneal adhesions (PA) are a postoperative syndrome with high incidence rate, which can cause chronic abdominal pain, intestinal obstruction, and female infertility. Previous studies have identified that PA are caused by a disordered feedback of blood coagulation, inflammation, and fibrinolysis. Monocytes, macrophages, fibroblasts, and mesothelial cells are involved in this process, and secreted signaling molecules, such as tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), tissue plasminogen activator (tPA), and type 1 plasminogen activator inhibitor (PAI-1), play a key role in PA development. There have been many attempts to prevent PA formation by anti-PA drugs, barriers, and other therapeutic methods, but their effectiveness has not been widely accepted. Treatment by biomaterial-based barriers is believed to be the most promising method to prevent PA formation in recent years. In this review, the pathogenesis, treatment approaches, and animal models of PA are summarized and discussed to understand the challenges faced in the biomaterial-based anti-PA treatments.

Postoperative peritoneal adhesion: an update on physiopathology and novel traditional herbal and modern medical therapeutics

Postoperative peritoneal adhesion (PPA) is a serious clinical condition that affects the high percentage of patients after abdominal surgery. In this review, we have tried to focus on pathophysiology and different underlying signal pathways of adhesion formation based on recent progress in the molecular and cellular mechanisms. Also, the strategies, developed based on traditional herbal and modern medicines, to prevent and treat the PPA via regulation of the molecular mechanisms were investigated. The search engines such as Google Scholar, PubMed, Scopus, and Science Direct have been used to evaluate the current literature related to the pathogenesis of adhesion formation and novel products. Recently, different mechanisms have been defined for adhesion formation, mainly categorized in fibrin formation and adhesion fibroblast function, inflammation, and angiogenesis. Therefore, the suppression of these mechanisms via traditional and modern medicine has been suggested in several studies. While different strategies with encouraging findings have been developed, most of the studies showed contradictory results and were performed on animals. The herbal products have been introduced as safe and effective agent which can be considered in future preclinical and clinical studies. Although a wide range of therapeutics based on traditional and modern medicines have been suggested, there is no agreement in the efficacy of these methods to prevent or treat adhesion formation after surgeries. Further basic and clinical researches are still needed to propose the efficiency of recommended strategies for prevention and treatment of PPA.