Smart hydrogels delivered by high pressure aerosolization can prevent peritoneal adhesions

Postoperative peritoneal adhesions occur in the majority of patients undergoing intra-abdominal surgery and are one of the leading causes of hospital re-admission. There is an unmet clinical need for effective anti-adhesive biomaterials, which can be applied evenly across the damaged tissues. We examined three different responsive hydrogel types, i.e. a thermosensitive PLGA-PEG-PLGA, a pH responsive UPy-PEG and a shear-thinning hexapeptide for this purpose. More specifically, their potential to be homogeneously distributed in the peritoneal cavity by high pressure nebulization and prevent peritoneal adhesions was evaluated. Solutions of each polymer type could be successfully nebulized while retaining their responsive gelation behavior in vitro and in vivo. Furthermore, none of the polymers caused in vitro toxicity on SKOV3-IP2 cells. Following intraperitoneal administration, both the PLGA-PEG-PLGA and the hexapeptide hydrogels resulted in local inflammation and fibrosis and failed in preventing peritoneal adhesions 7 days after adhesion induction. In contrast, the pH sensitive UPy-PEG formulation was well tolerated and could significantly reduce the formation of peritoneal adhesions, even outperforming the commercially available Hyalobarrier® as positive control. To conclude, local nebulization of the bioresponsive UPy-PEG hydrogel can be considered as a promising approach to prevent postsurgical peritoneal adhesions.

Variability in the management of adhesive small bowel obstruction in children

BACKGROUND

This study assessed inter-hospital variability in operative-vs-nonoperative management of pediatric adhesive small bowel obstruction (ASBO).

METHODS

A multi-institutional retrospective study was performed examining patients 1-21 years-of-age presenting with ASBO from 2010 to 2019 utilizing the Pediatric Health Information System. Multivariable mixed-effects logistic regression was performed assessing inter-hospital variability in operative-vs-nonoperative management of ASBO.

RESULTS

Among 6410 pediatric ASBO admissions identified at 46 hospitals, 3,239 (50.5%) underwent surgery during that admission. The hospital-specific rate of surgery ranged from 35.3% (95%CI: 28.5-42.6%) to 74.7% (66.3-81.6%) in the unadjusted model (p < 0.001), and from 35.1% (26.3-45.1%) to 73.9% (66.7-79.9%) in the adjusted model (p < 0.001). Factors associated with operative management for ASBO included admission to a surgical service (OR 2.8 [95%CI: 2.4-3.2], p < 0.001), congenital intestinal and/or rotational anomaly (OR 2.5 [2.1-3.1], p < 0.001), diagnostic workup including advanced abdominal imaging (OR 1.7 [1.5-1.9], p < 0.001), non-emergent admission status (OR 1.5 [1.3-1.8], p < 0.001), and increasing number of complex chronic comorbidities (OR 1.3 [1.2-1.4], p < 0.001). Factors associated with nonoperative management for ASBO included increased hospital-specific annual ASBO volume (OR 0.98 [95%CI: 0.97-0.99], p = 0.002), older age (OR 0.97 [0.96-0.98], p < 0.001), public insurance (OR 0.87 [0.78-0.96], p = 0.008), and presence of coinciding non-intestinal congenital anomalies, neurologic/neuromuscular disease, and/or medical technology dependence (OR 0.57 [95%CI: 0.47-0.68], p < 0.001).

CONCLUSIONS

Rates of surgical intervention for ASBO vary significantly across tertiary children's hospitals in the United States. The variability was independent of patient and hospital characteristics and is likely due to practice variation.

LEVEL OF EVIDENCE

III.

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.

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.

Peritoneal adhesions do not increase intra-operative organ injury or adverse neonatal outcomes during a repeated cesarean delivery

PURPOSE

To examine whether the presence of peritoneal adhesions at the second cesarean delivery (CD), attributable to the first CD, are associated with maternal intra-operative organ injury and adverse neonatal outcomes.

METHODS

A retrospective cohort study was conducted, comparing severe maternal intra-operative organ injury and adverse neonatal outcomes, between women with and without peritoneal adhesions. All women with two CDs during the follow-up period were included. Women with adhesions diagnosed during the first CD, history of other abdominal or pelvic surgery, pelvic infection or pelvic inflammatory disease, endometriosis, uterine Mullerian anomalies and newborns with known chromosomal or structural abnormalities were excluded, resulting in 7925 women. Intra-operative peritoneal organ injury was defined as a composite of bladder injury, ureteral injury, small bowel injury or hysterectomy. The examined adverse neonatal outcomes were low 1 and 5 min Apgar scores, intrapartum death (IPD) and postpartum death (PPD). Multivariate logistic regression was performed.

RESULTS

Peritoneal adhesions at the second CD, attributable to the first CD were diagnosed in 32.6% of patients (n = 2581). The presence of peritoneal adhesions was not found to be independently associated with intra-operative organ injury nor with 5 min Apgar scores, IPD and PPD. Second CDs complicated with adhesions were found to be associated with low (< 7) 1 min Apgar scores (adjusted OR 1.38, CI 1.20-1.58, p < 0.001).

CONCLUSION

Adhesions attributable to a previous CD do not seem to increase the risk for intra-operative organ injury and adverse neonatal outcomes. These findings may assist in reassuring patients who are facing a second CD.

Peritoneal adhesions during cesarean delivery are an independent risk factor for peri-partum hemorrhagic complications

OBJECTIVE

To investigate whether the presence of peritoneal adhesions at the second cesarean delivery (CD) are associated with peri-partum hemorrhagic complications.

STUDY DESIGN

A retrospective cohort study was undertaken, comparing hemorrhagic complications in the second CD, between women with and without adhesions. All women with two CDs who delivered a singleton in their second CD between the years 1988-2016 at a large regional medical center in Israel were included. Women with adhesions diagnosed at the first CD and women with a history of other abdominal or pelvic surgery, pelvic infection or inflammatory disease, endometriosis, uterine Mullerian anomalies and fetal chromosomal or structural abnormalities were excluded from the analysis, resulting in a sample of 7925 women. Peri-partum hemorrhagic complications were defined as a composite of vessel ligation, B lynch procedure during the CD or uterine rupture, third stage or immediate postpartum hemorrhage, blood component transfusion, hemorrhagic shock and maternal anemia [hemoglobin (Hb) levels prior to maternal discharge below 9.0 g\dl]. In order to identify variables that are independently associated with the composite peri-partum hemorrhagic complications a multivariate logistic regression analysis was performed, to control for potential confounders. In addition, a linear regression model was constructed with Hb levels as the outcome variable.

RESULTS

During the study period, 32.6 % of patients (n = 2581) suffered from adhesions during the second CD. After adjusting for potential confounders, peri-partum hemorrhagic complications were found to be significantly associated with the presence of peritoneal adhesions (adjusted OR 1.18, CI 1.04-1.33, P = 0.008). A multivariate linear regression analysis revealed that peritoneal adhesions were independently associated with a decline in post-partum Hb levels (β=-0.055, P < 0.001).

CONCLUSION

Adhesions attributable to a previous CD increase the risk for hemorrhagic complications. Interventions aimed at preventing adhesions formation during the primary CD may have a role in reducing hemorrhagic complications in subsequent CDs.

A new approach to avoid ovarian failure as well function-impairing adhesion formation in endometrioma infertility surgery

PURPOSE

Deep ovarian endometriosis surgery is likely to be associated with diffuse bleeding, intraoperative ovarian tissue destruction and perioperative adhesion formation. A new surgical approach is hereby proposed to avoid the negative short-term impact of classic laparoscopic cystectomy on ovarian reserve.

RESULTS

The need for intraoperative periovarian coagulation after endometrioma excision was avoided by combining the gold standard minimal-access endometrioma stripping technique with a purely plant-based medical product with high-hemostatic and antiadhesion barrier properties.

CONCLUSION

Endometrioma stripping followed by the application of a polysaccharide agent could avoid ovarian failure and at same time could reduce adhesion formation, thereby preserving tubo-ovarian function in endometrioma surgery. We encourage other surgically working groups to investigate middle- and long-term effects of this combined technique.

Adhesions and Anti-Adhesion Systems Highlights

The peritoneal and intrauterine cavities are lined by fragile membranes with a high-wound healing capacity, e.g. repairing the endometrium in its cyclical "injury and scar-free repair process" during menstruation. However, peritoneal and intrauterine fibrosis and adhesions can develop after surgical trauma through activation of molecular, immune and genetic mechanisms. During procedures with a high-risk of adhesions, the use of new peritoneal and intrauterine conditions in combination with anti-adhesion substances are promising measures to preserve peritoneal and endometrial function and avoid the most common complication of gynecological surgery. Highlights of adhesions and anti-adhesion prevention techniques in laparoscopic, laparotomic and hysteroscopic surgeries are discussed in this paper. Unfortunately, evidence is lacking to prove the superiority of one technique over its counterparts in terms of postoperative adhesions, such as instrumentation, type of energy, distending media, and intracavitary pressure. Additionally, there is limited evidence about the efficacy and outcomes of techniques and adjuvant measures used during adhesiolysis. The definition of a universal intrauterine adhesions classification scheme as well as a prognostic scoring system to identify women at high risk of postoperative adhesions are necessary for advising those who could benefit the most of the use of antiadhesion barriers.

Implementation of phospholipids as pharmacological modalities for postoperative adhesions prevention

Adhesions formation is considered a significant clinical entity implicating the healing process following major abdominal surgery, with serious clinical consequences and need for substantial health care expenditures. Several agents and substances applied either locally or systematically could potentially function as inhibitors of the formation of peritoneal adhesions endowed by limiting tissue apposition during the critical stages of mesothelial repair. Phospholipids are identified as surfactant-like substances, acting as a temporary membrane-like coverage of serosal defects. The experimental use of phospholipids for adhesions formation totals 24 publications. All retrieved studies, out of two, demonstrated the efficacy of phospholipids use in adhesions prevention. A single intraperitoneal dose of approximately 75 mg/kg of phosphatidylcholine, for a 30-min exposure time, emerges as the standard practice in terms of efficacy in both surgical alone or combined to peritonitis settings. The findings revealing an unimpeded healing of anastomoses and laparotomy wounds support the safety of this agent. The two additional properties of intraperitoneal use of phospholipids involve the inhibition of bacterial adherence/growth following impregnation of intra-abdominal drainages with phospholipids, without influencing bacterial translocation and the elimination of peritoneal carcinosis, through inhibition of intraperitoneal adhesion of tumor cells. The latter effect is achieved by a dose of phospholipids equal to 150 mg/kg. These experimental data, support that the intraperitoneal phospholipids administration can forestall adhesions formation following intra-abdominal surgical trauma, with no considerable overdosing-related adverse effects. Furthermore, these substances could possibly attenuate posttraumatic inflammation, and inhibit intraperitoneal tumor cell adhesion.

Prevention and treatment of peritoneal adhesions in patients affected by vascular diseases following surgery: a review of the literature

Intra-abdominal adhesions are the most frequently occurring postoperative complication following abdomino-pelvic surgery. Abdominal and pelvic surgery can lead to peritoneal adhesion formation causing infertility, chronic pelvic pain, and intestinal obstruction. Laparoscopy today is considered the gold standard of care in the treatment of several abdominal pathologies as well as in a wide range of vascular diseases. Laparoscopy has several advantages in comparison to open surgery. These include rapid recovery times, shorter hospitalisation, reduced postoperative pain, as well as cosmetic benefits. The technological improvements in this particular surgical field along with the development of modern techniques and the acquisition of specific laparoscopic skills have allowed for its wider utilization in operations with fully intracorporeal anastomoses. Postoperative adhesions are caused by aberrant peritoneal healing and are the leading cause of postoperative bowel obstruction. The use of anti-adherence barriers is currently being advocated for their prevention. The outcome of the investigation showed adhesion formation inhibition without direct detrimental effects on anastomotic healing. Poor anasto-motic healing can provoke adhesions even in the presence of anti-adhesion barriers. This review gives a short overview on the current evidence on the pathophysiology and prevention of peritoneal adhesions.

Pathobiological mechanisms of peritoneal adhesions: The mesenchymal transition of rat peritoneal mesothelial cells induced by TGF-β1 and IL-6 requires activation of Erk1/2 and Smad2 linker region phosphorylation

Peritoneal adhesions, primarily caused by surgical procedures, are the leading cause of pelvic pain, bowel obstruction, and infertility. TGF-β1 and IL-6 have been found to be elevated in the peritoneal fluid of patients during/after abdominal surgery. However, it remains to be determined whether these cytokines interact and facilitate adhesion formation by promoting mesothelial to mesenchymal transition (MMT). In the present study, isolated rat peritoneal mesothelial cells were treated with TGF-β1 and/or IL-6 which elicited MMT as determined by morphologic and biochemical techniques. During this transition, cellular morphology changed from that of cobblestone polygonal cells to elongated/spindle-shaped fibroblast-like cells. There was decreased expression of genes characteristic of mesothelial cells, such as E-cadherin, and increased expression of genes characteristic of the myofibroblast phenotype, including α-smooth muscle actin and the EDA form of fibronectin, both of which appear to mediate the transfer of force to the extracellular matrix. Partial characterization of relevant signaling pathways identified Erk1/2 activation, which was enhanced by combined TGF-β1/IL-6 administration, as a crucial necessary factor in the transition. Erk1/2 activation as well as the phosphorylation of the linker region of Smad2 and MMT could be blocked by the MEK inhibitor, U0126, suggesting that such activation may be a potential pharmaceutical target to prevent MMT. In addition, the phenotypic transition could be prevented by hydrocortisone.

Mutant matrix metalloproteinase-9 reduces postoperative peritoneal adhesions in rats

INTRODUCTION

Postoperative peritoneal adhesions continue to be a major source of morbidity and occasional mortality. Studies have shown that matrix metalloproteinase-9 (MMP-9) levels are decreased postoperatively which may limits matrix degradation and participate in the development of peritoneal adhesions. In this proof-of-principle study, we evaluated the effect of gene therapy with catalytically inactive mutant MMP-9 on postoperative peritoneal adhesions in rats.

METHODS

Adenovirus encoding mutant MMP-9 (Ad-mMMP-9) or saline was instilled in the peritoneal cavity after cecal and parietal peritoneal injury in rats. Expression of mutant MMP-9 transcript was verified by sequencing. Adenovirus E4 gene expression, adhesion scores, MMP-9, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-β1 (TGF-β1) expression were evaluated at sacrifice one week after treatment.

RESULTS

Both mutant MMP-9 transcripts and adenovirus E4 gene were expressed in Ad-mMMP-9 treated adhesions. Adhesions severity decreased significantly (p = 0.036) in the Ad-mMMP-9-treated compared with saline-treated adhesions. Expression of MMP-9 mRNA and protein were elevated (p = 0.001 and p = 0.029, respectively) in the Ad-mMMP-9-treated adhesions compared with saline-treated adhesions. While tPA levels were increased (p = 0.02) in Ad-mMMP-9 treated adhesions compared with saline-treated adhesions, TGF-β1 and PAI-1 levels were decreased (p = 0.017 and p = 0.042, respectively). No difference in mortality were found between groups (p = 0.64).

CONCLUSIONS

Mutant MMP-9 gene therapy effectively transduced peritoneal adhesions resulting in reduction of severity of primary peritoneal adhesions.

The Effects of Hydrophilic Polyethylene Glycol-Based Adhesion Barrier Use to Prevent Intra-abdominal Adhesions in Intra-abdominal Sepsis Model

Postoperative adhesion formation is still an important cause of morbidity and mortality. Hydrophilic polyethylene glycol-based adhesion barrier (SprayGel™, Confluent Surgical, Inc., Waltham, MA) is reported to prevent adhesion formation after gynecologic surgery. This study aims to determine the effectiveness of SprayGel™ on adhesion formation after laparotomy in an experimental septic peritonitis model. Wistar albino male rats with weights of 250-350 g were used in this study. Forty rats were grouped into four groups: group I (control), laparotomy and sham operation; group II, laparotomy and cecal ligation puncture (CLP); group III (SprayGel™), laparotomy, sham operation, and SprayGel™; group IV (CLP + SprayGel™), laparotomy, CLP, and SprayGel™. Intra-abdominal sepsis was achieved by perforating the cecum with a 26-gauge needle in selected groups. All animals were sacrificed after 10 days. The results were evaluated according to the score systems of Nair and Knightly. Kruskal-Wallis variance analysis was used for statistical analysis. There were significant differences for the development of adhesion between groups II (CLP) and III-IV (SprayGel™ - CLP + SprayGel™) (p < 0.02). Mortality and wound infection rates were significantly lower in the SprayGel™ treatment groups compared to control groups. Intraperitoneal administration of SprayGel™ significantly decreased the intraperitoneal adhesion formation, and it reduced mortality and wound infection as well.

Locally increased concentrations of inflammatory cytokines in an experimental intraabdominal adhesion model

BACKGROUND

Peritoneal adhesions may cause bowel obstruction, infertility, and pain. This study investigated cytokines, proteins and growth factors thought to promote formation of adhesions in an experimental intraabdominal adhesion model.

METHODS

Male Sprague-Dawley rats were subjected to laparotomy, cecal abrasion, and construction of a small bowel anastomosis and examined at various time points after surgery. Concentrations of cytokines and growth factors in plasma and peritoneal fluid were analyzed using electrochemoluminescence and quantitative sandwich enzyme immunoassay technique.

RESULTS

Concentrations of interleukin-6 (IL-6), interleukin-1beta (IL-1β), and tumor necrosis factor alpha (TNF-α) increased in peritoneal fluid from 6h after incision. Plasma concentrations of IL-6 increased at 6h, but plasma concentrations of IL-1β and TNF-α remained low. Peritoneal fluid concentrations of platelet-derived growth factor-BB (PDGF-BB), transforming growth factor beta1 (TGF-β1), vascular endothelial growth factor (VEGF), tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) were below detection levels at all time points.

CONCLUSION

Early elevations of IL-6, IL-1β, and TNF-α concentrations in peritoneal fluid correlated to adhesion formation in this rodent model. Our model is relevant and reproducible, suitable for intervention, and indicates that antiadhesion strategies should be early, local and not systemic.

Peritoneal adhesions after laparoscopic gastrointestinal surgery

Although laparoscopy has the potential to reduce peritoneal trauma and post-operative peritoneal adhesion formation, only one randomized controlled trial and a few comparative retrospective clinical studies have addressed this issue. Laparoscopy reduces de novo adhesion formation but has no efficacy in reducing adhesion reformation after adhesiolysis. Moreover, several studies have suggested that the reduction of de novo post-operative adhesions does not seem to have a significant clinical impact. Experimental data in animal models have suggested that CO₂ pneumoperitoneum can cause acute peritoneal inflammation during laparoscopy depending on the insufflation pressure and the surgery duration. Broad peritoneal cavity protection by the insufflation of a low-temperature humidified gas mixture of CO₂, N₂O and O₂ seems to represent the best approach for reducing peritoneal inflammation due to pneumoperitoneum. However, these experimental data have not had a significant impact on the modification of laparoscopic instrumentation. In contrast, surgeons should train themselves to perform laparoscopy quickly, and they should complete their learning curves before testing chemical anti-adhesive agents and anti-adhesion barriers. Chemical anti-adhesive agents have the potential to exert broad peritoneal cavity protection against adhesion formation, but when these agents are used alone, the concentrations needed to prevent adhesions are too high and could cause major post-operative side effects. Anti-adhesion barriers have been used mainly in open surgery, but some clinical data from laparoscopic surgeries are already available. Sprays, gels, and fluid barriers are easier to apply in laparoscopic surgery than solid barriers. Results have been encouraging with solid barriers, spray barriers, and gel barriers, but they have been ambiguous with fluid barriers. Moreover, when barriers have been used alone, the maximum protection against adhesion formation has been no greater than 60%. A recent small, randomized clinical trial suggested that the combination of broad peritoneal cavity protection with local application of a barrier could be almost 100% effective in preventing post-operative adhesion formation. Future studies should confirm the efficacy of this global strategy in preventing adhesion formation after laparoscopy by focusing on clinical end points, such as reduced incidences of bowel obstruction and abdominal pain and increased fertility.

Prevention of peritoneal adhesions using polymeric rheological blends

The effectiveness of rheological blends of high molecular weight hyaluronic acid (HA) and low molecular weight hydroxypropyl methylcellulose (HPMC) in the prevention of peritoneal adhesions post-surgery is demonstrated. The physical mixture of the two carbohydrates increased the dwell time in the peritoneum while significantly improving the injectability of the polymer compared with HA alone. HA-HPMC treatment decreased the total adhesion area by ∼ 70% relative to a saline control or no treatment in a repeated cecal injury model in the rabbit. No significant cytotoxicity and minimal inflammation were associated with the blend. Furthermore, no chemical or physical processing was required prior to their use beyond simple mixing.

Involvement of transforming growth factor-β3 and betaglycan in the cytoarchitecture of postoperative omental adhesions

BACKGROUND

Adhesions commonly appear in patients after abdominal surgery, with considerable individual variation in adhesion composition and severity of the repair process. Here, we address the influence of transforming growth factor (TGF)-β3 and betaglycan in this response, in relation to TGF-β1, in an adhesiogenic rabbit model.

MATERIALS AND METHODS

Omental adhesions were recovered 3, 7, 14, and 90 d after the implantation of a polypropylene mesh on the parietal peritoneum in New Zealand White rabbits. Omentum from nonoperated animals served as control. Tissue specimens were examined for TGF-β3 and TGF-β1 (Western blotting, reverse transcription-polymerase chain reaction), and TGF-β1:TGF-β3 messenger RNA and protein expression ratios were analyzed. Immunohistochemical detection of TGF-β3 and betaglycan was performed.

RESULTS

Injury to the omentum led to mobilization of TGF-β3 and betaglycan-expressing cells from milky spots. Fibrous zones in adhesions were simultaneous to the presence of TGF-β1 and the membrane-bound form of betaglycan (7-d adhesions), whereas soluble betaglycan appeared in TGF-β1-positive areas showing limited fibrosis (3-d adhesions). The elevated expression of TGF-β3 concurrent with the presence of membrane-bound form of betaglycan was observed in zones of adipose regeneration (14-d adhesions), whereas zones of fibrous consistency were negative for TGF-β3.

CONCLUSIONS

Milky spots on the omentum contain inflammatory/immune cells positive for TGF-β3, TGF-β1, and betaglycan, playing a role in the damaged omentum repair. Our observations support the contribution of TGF-β3 to tissue repair through adipose tissue regeneration and the profibrotic role of TGF-β1 and suggest that these effects on the local wound repair response could be driven by the expression of betaglycan in its soluble or membrane-bound form.

Current status of the use of antiadhesive agents for gastric cancer surgery: a questionnaire survey in South Korea

PURPOSE

The aim of this study was to investigate the current status of the use of antiadhesive agents (AAdAs) via a questionnaire and to discuss the availability of AAdAs.

METHODS

The survey was sent to a list of members that was approved by the Korean Gastric Association. The survey included questions on AAdA use by surgeons, the type of AAdAs used, and the reasons for not using AAdAs. Surgeons were also asked to describe complications related to AAdAs, and the reliability of its use.

RESULTS

The response rate was 21%. The rates of frequent use stratified by procedure were 26.9% (14/52) for open gastrectomy, 5.9% (3/51) for laparoscopic gastrectomy, and 31.5% (17/54) for surgery for postoperative bowel obstruction (P < 0.01). After including data from the occasional use group, the corresponding values were 51.9% (27/52), 19.6% (10/51), and 70.4% (38/54), respectively (P < 0.01). Sefrafilm and Guardix were most commonly used for open procedures. Guardix and Interceed were most commonly used for laparoscopic surgery. The primary reasons for nonuse of AAdAs were ineffectiveness and high cost. Ten percent (4/40) of surgeons observed complications associated with AAdAs. A minority (17.3%, 9/52) had positive attitudes toward AAdAs. The majority of respondents expressed neutral (73.1%, 38/52) or negative (9.6%, 5/52) attitudes toward AAdAs.

CONCLUSION

The low use rates of AAdAs in gastric cancer surgery may be attributable to perceptions that AAdAs are ineffective, unreliable, and costly. We anticipate the emergence of promising antiadhesive strategies that reach far beyond the limitations of current products.

Prevention of peritoneal adhesions: a promising role for gene therapy

Adhesions are the most frequent complication of abdominopelvic surgery, yet the extent of the problem, and its serious consequences, has not been adequately recognized. Adhesions evolved as a life-saving mechanism to limit the spread of intraperitoneal inflammatory conditions. Three different pathophysiological mechanisms can independently trigger adhesion formation. Mesothelial cell injury and loss during operations, tissue hypoxia and inflammation each promotes adhesion formation separately, and potentiate the effect of each other. Studies have repeatedly demonstrated that interruption of a single pathway does not completely prevent adhesion formation. This review summarizes the pathogenesis of adhesion formation and the results of single gene therapy interventions. It explores the promising role of combinatorial gene therapy and vector modifications for the prevention of adhesion formation in order to stimulate new ideas and encourage rapid advancements in this field.

The effect of Kombucha on post-operative intra-abdominal adhesion formation in rats

BACKGROUND

Peritoneal adhesions are fibrous bands of tissues formed between organs that are normally separated and/or between organs and the internal body wall after peritoneal injury. The aim of the study was to investigate the effect of intra-peritoneal administration of Kombucha on intra-peritoneal adhesions.

MATERIALS AND METHODS

Eighty Wistar rats were subjected to standardized lesion by scraping model and were randomly divided into two groups. Group I received no treatment, and Group II received 15 ml of Kombucha solution intra-peritoneally. On the post-operative 14th day adhesion intensity score, inflammatory cell reaction and number of adhesion bands were determined.

RESULTS

In the control group, there were no rats with grade 0 and I adhesions. In the group II, there were 26 rats (78.8%) with grade 0-2 adhesions. Adhesion intensity was significantly less in group II (P<0.0001). Number of adhesion bands was significantly less in group II (P<0.001).

CONCLUSION

It was concluded that intra-peritoneal administration of Kombucha might be useful for preventing peritoneal adhesions.

The effect of piroxicam on the formation of postoperative, intraabdominal adhesion in rats

BACKGROUND/AIMS

Peritoneal adhesions are fibrous bands of tissues formed between organs that are normally separated and/or between organs and the internal body wall after peritoneal injury. Antiinflammatory agents were used to reduce the initial inflammatory response to tissue injury and, hence, the subsequent formation of adhesion. The aim of this study was to investigate the effect of intraperitoneal instillation of piroxicam on intraperitoneal adhesions.

METHODS

Eighty Wistar rats were subjected to standardized lesion by using the scraping model and were randomly divided into four groups. Group I (control) received no treatment; groups II, III, and IV received 10-12.5 mL of 0.05, 0.1, and 0.2 mg/mL piroxicam solution, respectively, after surgery. On the 14th postoperative day, the adhesion intensity score, inflammatory cell reaction, and the number of adhesion bands were determined.

RESULTS

There were no rats with grade 0 adhesions in the control group. There were 10 rats (50%) with grade 2 and eight rats (40%) with grade 3 adhesions. The adhesion intensity (P < 0.0001) and the number of adhesion bands (P < 0.001) were significantly lower in groups III and IV. No significant difference was observed in the adhesion intensity or the number of adhesion bands between groups I and II.

CONCLUSIONS

Intraperitoneal instillation of piroxicam solution might be useful for preventing peritoneal adhesions.