Effect of Pirfenidone on Vascular Proliferation,Inflammation and Fibrosis in an Abdominal Adhesion Rat Model

Aim: To study the efficacy of pirfenidone for prevention of postoperative adhesion formation in an adhesion rat model. Materials and Methods: Eighteen female Wistar rats were subjected to right-sided parietal peritoneum and right uterine horn adhesion model. Rats were randomized into three groups: group 1 (control) (closure of midline abdominal incision without any agent administration), group 2 (closure of incision after intraperitoneal administration of pirfenidone), and group 3 (closure of incision and only oral administration of pirfenidone for 14 days). Relaparotomy was performed 14 days after the first surgery. Effect of pirfenidone on adhesion formation was assessed on light microscopy by scoring vascular proliferation, inflammation, fibrosis, and collagen formation in the scarred tissue. Effect of pirfenidone on inflammation was assessed by measurement of transforming growth factor-β and interleukin-17 levels in scarred tissue. Results: The degree of vascular proliferation (1.32 ± 0.39 versus 2.34 ± 0.46, p < 0.001), inflammation (1.60 ± 0.70 versus 2.60 ± 0.52, p < 0.01), and fibrosis (1.50 ± 0.53 versus 2.40 ± 0.52, p < 0.01) were less prominent in group 2 compared to group 1, respectively. Only vascular proliferation was found to be less prominent in group 3 compared to group 1 (1.60 ± 0.42 versus 2.34 ± 0.46, p < 0.01). Intraperitoneal and oral administration of pirfenidone reduced tissue levels of inflammatory markers (TGF-β and IL-17) in parietal and visceral peritoneum compared to control group. Intraperitoneal administration of pirfenidone compared to oral administration was more effective in reducing tissue levels of inflammatory markers. Conclusion: Pirfenidone is an effective agent on the prevention of postoperative vascular proliferation, inflammation and fibrosis in scarred tissue particularly with intraperitoneal administration.     

Prevention of Adhesion Formation with Intraperitoneal Administration of Tolmetin and Hyaluronic Acid

Adhesion formation after peritoneal surgery is a major source of postoperative complications and pain. Previous studies showed that intraperitoneal administration of the nonsteroidal anti-inflammatory drug tolmetin reduced adhesion formation after two types of peritoneal surgery. The effect of tolmetin combined with hyaluronic acid (HA), a high-molecular-weight glucosaminoglycan found in the extracellular matrix, on the formation of adhesions was examined. In this study, the effect of tolmetin in HA on adhesion formation was evaluated in a standardized rabbit model. The medicament was administered intraperitoneally at the end of surgery. One week after surgery, a second laparotomy was performed and the extent of adhesion formation was determined. A range of molecular weights (7.5 × 10⁵-2 × 10⁶ Da) and viscosities (1000–25,000 centapoise) of HA in combination with tolmetin was effective in reducing adhesion formation. However, low viscosity HA solutions in combination with tolmetin, 0˙5–2˙0 mg/mL, were most efficacious in reducing adhesion formation. These data suggest that HA, in combination with tolmetin, acts as an effective carrier to reduce adhesion formation in the abdominal cavity after surgery.     

Influence of Hydroxyethyl Starch on Healing of Colonic Anastomosis in a Rat Model of Peritonitis

Background: This study was designed to evaluate the role of different intravascular volume replacement regimens of HES 130/0.4 on wound healing process in left colonic anastomoses in the presence of intra-abdominal sepsis induced by murine model of cecal ligation and puncture (CLP). Methods: The left colonic anastomosis was performed in 40 rats that were divided into five groups (n = 8/group): saline controls (30 ml/kg); CLP plus saline (30 ml/kg); CLP plus HES (7.5, 15, or 30 ml/kg, respectively). Saline or HES was treated before the construction of left colonic anastomosis and on a regular daily basis. Anastomotic bursting pressures were measured in vivo on day 5. Tissue samples were obtained for analyses of hydroxyproline (HP) contents, myeloperoxidase (MPO) acivity, malondialdehyde (MDA), reduced glutathione (GSH) levels, and nuclear factor-κ B (NF-κ B) activation. The plasma levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 were also measured. Results: Intra-abdominal sepsis led to significant decreases in colonic anastomotic bursting pressures, and perianastomotic tissue HP contents and GSH levels, along with increases in perianastomotic tissue MPO activity, MDA levels and NF-κ B activation and plasma levels of TNF-α and IL-6. After treated with HES, these provoked perianastomotic tissue MPO activity, MDA levels, NF-κ B activation, and plasma levels of TNF-α and IL-6 were suppressed and GSH levels were restored, especially in 15 ml/kg HES group. Without obvious influence on systemic nutritional condition, HES 15 ml/kg but not HES 7.5 ml/kg significantly increased anastomotic bursting pressures, and perianastomotic tissue HP contents. However, HES 30 ml/kg even led to adverse effects on anastomotic bursting pressures. Conclusions: This study showed that moderate doses (15 ml/kg) of HES 130/0.4 administration significantly prevented this intraperitoneal sepsis-induced impaired anastomotic healing of the left colon. It also suggested the possibility of poorer anastomotic healing receiving HES at higher doses (30 ml/kg). Clearly, HES 130/0.4 now should not be recommended to use at a high doses postoperatively in sepsis.     

Spiral Tacks May Contribute to Intra-Abdominal Adhesion Formation

Purpose With the inception of laparoscopic ventral hernia repair came a novel device not used in conventional hernia repair; the spiral tack. We conducted an experimental study on pigs to determine whether spiral tacks contribute to adhesion formation.Methods Using a standard laparoscopic technique in pigs, pieces of polypropylene mesh were fixed to the fascia on the upper abdominal wall, with polypropylene sutures on a randomly chosen side (side 1), and with 5-mm spiral tacks on the opposite side (side 2). The extent, type, and tenacity of the adhesions were assessed on postoperative days (PODs) 30 and 90.Results The mesh fixed to the abdominal wall with spiral tacks tended to increase the extent, type, and tenacity of adhesions more than the mesh fixed with polypropylene sutures (P < 0.05).Conclusions Spiral tacks contributed to the formation of adhesions more than polypropylene mesh did. Although this was a small-scale animal study, our findings suggest that the effect of spiral tacks used in laparoscopic ventral hernia repair should be assessed and the consequences monitored more closely.This study was presented at the joint meeting of the Turkish National Surgery Congress, Antalya, Turkey, 15–19 May, 2002     

Adhesion Formation: Intraperitoneal Catheters in Surgical Practice

To compare the adhesion formation, in a rat model, of commercially available materials used as intraperitoneal catheters in clinical practice, pieces of polyurethane, Teflon, silicone, and polyvinyl chloride (PVC) were placed intraperitoneally in 36 female Wistar rats randomly assigned into four groups. Adhesion development was quantitated according to Nair's classification system (NCS). According to NCS, polyurethane showed the least adhesion formation, while the highest scores were found in the PVC group. Comparing the thickness and the firmness of adhesions in the four groups, significant differences were found, with the polyurethane group developing none or filmy and mild adhesions. In contrast, almost all the rats in the Teflon group developed thick and dense adhesions. Thus, polyurethane caused the least adhesion formation among the four materials evaluated, and can be used more extensively for the construction of catheters for prolonged intraperitoneal use.     

Smokers, Risks, and Complications in Abdominal Dermolipectomy

Cigarette smoke has many detrimental effects on health, with consequences such as cardiovascular diseases, respiratory diseases, and tumors. In plastic surgery, these effects appear during the wound healing process. This retrospective study showed wound healing in 57 patients who had undergone abdominal dermolipectomy surgery. The patients were divided into two groups: smokers and nonsmokers. According to the results, smokers face a great complication risk for surgical wounds, which cause aesthetically more undesirable scars than observed in nonsmokers. The authors hypothesize that abstinence from smoking for 4 to 12 weeks before surgery would improve the quality of the scars.     

Optimal Timing and Temperature for Hyperthermic Preconditioning in an Animal Model of Fecal Peritonitis

The impact of immune parameters in the mechanism of hyperthermia is yet to be explained. In this study, the optimal timing and temperature of thermal treatment for reversing the abnormal immunologic parameters obtained in a rat model of peritonitis were planned to be determined. Male Sprague-Dawley rats were grouped as sham, control peritonitis, and thermally treated rats at the time of peritonitis or 4 h prior to induction of peritonitis both at 40 and 42°C. Peritonitis was induced by the cecal ligation and perforation model. Eight hours after the induction of peritonitis, rats were sacrified and samples were taken for measurements of CD 4 + , CD 8 + , CD 11b , B cells, NK cells, and tumor necrosis factor &#102 (TNF &#102 ) and thiobarbituric acid-reactive substances (TBARS) levels. CD 4 + expression and B cell amount were decreased whereas TNF &#102 levels, CD 8 + and CD 11b expression, and NK cell amount were found to be increased in the control peritonitis group when compared to the sham group. Peritonitis induction also increased TBARS levels in liver tissue. Hyperthermic preconditioning at either 40 or 42°C applied 4 h prior to peritonitis induction returned all parameters to their normal levels, which is similar to the results of the sham laparotomy group. The results of TNF &#102 values in preconditioned rats were varied according to the temperature that was applied. The levels were increased at 40°C, whereas they showed a decline at 42°C. Hyperthermic preconditioning prevented the oxidative damage in liver as well as TNF &#102 elevation, particularly at 42°C. Results from this study suggest that hyperthermic preconditioning 4 h prior to the onset of septic events may improve the adverse outcome in sepsis.     

Effects of Hypertension on Abdominal Wall Healing: Experimental Study in Rats

Purpose The aim of this study was to investigate the effects of untreated and treated hypertension on abdominal wall healing. Methods Thirty-two spontaneously hypertensive rats (SHR) were randomly allocated into two groups: H (n = 16), untreated and E (n = 16), treated with enalapril (40 mg/kg per day). Group C (n = 16) was a nonhypertensive control group. The animals of each group were submitted to a midline laparotomy and randomly divided, according to the day on which they were killed (7th or 14th postoperative day), into subgroups of 8 animals, as follows: H-7, H-14, E-7, E-14, C-7 and C-14. On the day of their deaths, two strips of the anterior abdominal wall were collected. One strip was submitted to breaking strength measurement and the other to hydroxyproline determination. Results No mortalities or complications were observed in the six subgroups. The breaking strength in E-7 subgroup was significantly lower than in C-7 (P < 0.05). The tissue hydroxyproline levels were similar in all six subgroups (P > 0.05). Conclusions Untreated hypertension had no effect on the abdominal wall healing of rats. Hypertensive animals treated with enalapril showed a significant decrease in abdominal wound-breaking strength on the 7th postoperative day.     

Reduction of adhesion formation and promotion of wound healing after laminectomy by pharmacological inhibition of pro-inflammatory cytokines: an experimental study in the rat

In a previous experiment using TNF inhibition in the rat it was accidentally found that adhesion and scar formation was reduced compared to previous experience. Wound and bone healing also seemed enhanced. The present study was conducted to assess if this observation could be verified in a controlled setting using a standardized laminectomy in the rat. Five rats received doxycycline and five other rats received saline and served as control. Macroscopic blinded evaluation 1 week after the laminectomy revealed that adhesion and scar formation was less in doxycycline-treated animals than in control animals. Wound and bone healing was found to be better in doxycycline-treated animals. The mechanisms for the observed effects cannot be fully understood but the data indicate that further research may lead to opportunities to design pharmacological modalities to reduce adhesion and scar formation, maybe in combination with suitable barriers.     

The Effects of Adjuvant Experimental Radioimmunotherapy and Hyperthermic Intraperitoneal Chemotherapy on Intestinal and Abdominal Healing after Cytoreductive Surgery for Peritoneal Carcinomatosis in the Rat

Background  Cytoreductive surgery (CS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) results in limited survival benefit and high morbidity and mortality rates in patients with peritoneal carcinomatosis (PC). Radioimmunotherapy (RIT) after CS of experimental PC has been shown to increase survival and compare favorably to HIPEC. The effects of RIT and HIPEC on wound healing after CS need to be determined. Methods  PC was induced by intraperitoneal inoculation of CC-531 colon carcinoma cells in Wag/Rij rats. Animals were subjected to CS and anastomotic construction only or followed by RIT or HIPEC. RIT consisted of 74 MBq ¹⁷⁷lutetium-labeled anti-CC531 antibody MG1. HIPEC was performed by a closed abdominal perfusion technique using mitomycin-C during 60 minutes. Anastomotic and abdominal wall strength measurements were performed 3 and 5 days after surgery. Results  At day 5, bursting pressure in ileum and colon anastomoses in the CS + HIPEC group, but not in the CS + RIT group, was lower (P < .01) than in the CS group. In the CS group, the colonic bursting site was more often outside the true anastomotic area (8 of 12 animals) than in the CS + HIPEC (1 of 12) and CS + RIT (5 of 12) groups. Abdominal wall strength in the CS + HIPEC group was significantly (P < .01) lower, at both measuring points, than that in both the CS group and the CS + RIT group. There was no difference between the latter. Conclusion  As adjuvant to CS, HIPEC showed a decrease in anastomotic and abdominal wall wound strength in a model of PC of CRC, whereas RIT did not.     

三种新型复合材料修补大鼠腹壁缺损的研究

目的观察三种新型国产复合补片修补腹壁缺损的效果,客观评价三种补片的防粘连效果。方法 Wistar大鼠120只,采用完全随机方法随机分为4组:①聚丙烯(PP)+聚丙交己内酯(PLC)组;②PP+透明质酸(HA)/PLC组;③PP+胶原/PLC组;④PP+膨体聚四氟乙烯(e-PTFE)组,每组30只。切除直径约1cm的大鼠全层腹壁,以直径1.5cm的补片进行修补,分别于术后30、60、90及180d处死,每次处死5只,根据Nair评分标准进行粘连评分,并进行组织学检查。结果术后各组大鼠均未出现死亡,在各时间点均出现腹腔粘连,主要为网膜、肠管。术后各时间点,PP+胶原/PLC组粘连评分均低于PP+e-PTFE组(P<0.05)。PP+HA/PLC组和PP+PLC组粘连评分与PP+e-PTFE组相比差异无统计学意义(P>0.05)。组织学检查显示,术后各时间点,各组补片周围均有炎性细胞浸润和成纤维细胞出现及胶原分泌,随时间推移炎症细胞逐渐减少,成纤维细胞逐渐增多,胶原分泌增多。术后30d胶原及HA层消失,PLC层出现断裂,在术后180dPLC层尚未被完全吸收,在4种补片腹腔面均有细胞或组织覆盖,将补片与腹腔内容物隔离,胶原/PLC复合补片的隔离层的连续性最好。结论 PLC、HA/PLC和胶原/PLC三种国产复合补片在动物实验中均具有良好的防粘连效果,其中胶原/PLC复合补片的防粘连效果最佳,且价格低廉,适于大众普遍使用,临床应用前景良好。     

The Effect of Granulocyte Colony-Stimulating Factor in the Treatment of <Emphasis Type="Italic">Escherichia coli</Emphasis> Peritonitis With or Without Ceftriaxone in a Nonneutropenic Rat Model

PURPOSE: To investigate the effect of granulocyte colony-stimulating factor (G-CSF) in the treatment of Escherichia coli peritonitis with and without ceftriaxone in a nonneutropenic rat model. METHODS: The rats were divided into five groups: control group (C) receiving physiological saline; peritonitis group (P) infected intraperitoneally with a live bacterial suspension of E. coli; peritonitis and antibiotic group (PA) receiving ceftriaxone 3 h after being infected; peritonitis, antibiotic, and G-CSF group (PAG) receiving G-CSF and antibiotic 3 h after infection; and peritonitis and G-CSF group (PG). RESULTS: All rats in group C survived. Any animals which did not survive died within 24h after inoculation. A significantly higher rate of survival, 95%, was observed with antibiotic treatment alone (PA), in comparison to the G-CSF-treated groups, PAG and PG, 52% and 57%, respectively. CONCLUSION: No beneficial effect of G-CSF treatment was seen in the E. coli peritonitis and antibiotic therapy remains the basic treatment for this disease.     

Aortic Length Changes During Abdominal Aortic Aneurysm Formation,Expansion and Stabilisation in a Rat Model

BackgroundDeterminants of extracellular matrix (ECM) destruction/reconstruction balance influencing abdominal aortic aneurysm (AAA) diameter may impact length.ObjectiveDocument aortic lengthening, its correlation to diameter, and determine how treatments that impact diameter also affect length.MethodsThree hundred and fifty-five diameter and length measurements were performed in 308 rats during AAA formation, expansion and stabilisation in guinea pig aortas xenografted in rats. Impact of modulation of ECM destructive/reconstructive balance by endovascular Vascular Smooth Muscle Cell (VSMCs) seeding, TIMP-1, PAI-1 and TGF-beta1 overexpression on length has been assessed.ResultsLength increased in correlation with diameter during formation (correlation coefficient (cc): 0.584, P < 0.0001) and expansion (cc: 0.352, P = 0.0055) of AAAs. Overexpression of TIMP-1 and PAI-1 decreased lengthening (P = 0.02 and 0.014, respectively) demonstrating that elongation is driven by matrix metalloproteinases and their activation by the plasmin pathway. Overexpression of TGF-beta1 controlled length in formed AAAs (17.3 ± 9.6 vs. 5.9 ± 7.4 mm, P = 0.022), but not VSMC seeding, although both therapies efficiently prevented further diameter increase. Length and diameter correlation was lost after biotherapies.ConclusionLength increases in correlation with diameter during AAA formation and expansion, as a consequence of ECM injury driven by MMPs activated by the plasmin pathway. Correlation between length and diameter increases is not universally preserved.     

Pilot study to evaluate a novel three‐dimensional wound measurement device

As the burden of diabetes continues to grow and treatment standards require careful tracking of wound progress, clinicians increasingly need to rely on technological improvements in wound measurement technologies to track the progress of their treatments. This study aims to determine the accuracy of a new three‐dimensional wound measurement (3DWM) device against laser‐assisted wound measurement (LAWM) devices and traditional methods of wound measurement. Using several wound models, we demonstrate that the 3DWM device measures wound area, depth and volume similarly to the other methods tested. This is especially apparent when changes in wound measurements were compared between the two devices. Differences between the two technologies were apparent when analysing wound measurement time and measurement repeatability. There was a significantly lower incidence of error in measurements between the 3DWM device and the LAWM device. Finally, the measurement time was significantly faster with the 3DWM device compared to the LAWM device. Together, these data demonstrate that the 3DWM device provides an accurate and reproducible method for measuring changes in wound healing similar to other available technologies. Further, the use of the 3DWM device provides a faster and more consistent measurement, which is critical for clinical application and use.     

Rat skin wound healing induced by alternagin-C, a disintegrin-like, Cys-rich protein from Bothrops alternatus venom

Alternagin‐C (ALT‐C) is a disintegrin‐like, Cys‐rich protein isolated from Bothrops alternatus snake venom, which has been shown to induce in vivo angiogenesis. Therefore, this protein could be interesting as a new approach for tissue regeneration studies. Here the effects of ALT‐C on fibroblasts and inflammatory cells, collagen type III and type I and TGF‐α expression in a rat wounded skin model were studied. Thirty‐five male Wistar rats (weight 270 ± 20 g) were divided into seven groups with five animals in each of the following groups: a control group which wounded animals received treatment with natrozol^® gel only; ALT‐C10, ALT‐C60 and ALT‐C100 groups of wounded animals that were treated with the same amount of gel containing 10, 60 and 100 ng of ALT‐C, respectively. Animals were treated once a day with 20 µl of gel associated or not with ALT‐C for 1, 3, 5 or 7 days. ALT‐C treatment increased the fibroblast density, collagen deposition and accelerated the inflammatory process, mostly in the ALT‐C60 group. These results indicate that ALT‐C improves wound repair process in rat skin. Thus, ALT‐C could be a candidate to the development of a novel therapeutic strategy for wounded skin repair.     

Listeria Monocytogenes Peritonitis in a Peritoneal Dialysis Patient with Severe Heart Failure

Listeria monocytogenes has rarely been reported to cause peritonitis in peritoneal dialysis (PD) patients. Listeriosis is usually a severe disease with a mortality rate of 20 to 40% in humans despite early antibiotic treatment. In this report we present the first case in Greece of peritonitis caused by L. monocytogenes, in a chronic PD patient with severe cardiac failure. The patient received prolonged antibiotic therapy with vancomycin and netilmicin which resulted in peritonitis resolution. Unfortunately however, the listeria infection caused decompensation of the patient’s cardiac failure and led to his death, despite appropriate antibiotic treatment. When peritoneal fluid cultures yield gram positive rods in an immune-compromised patient or on a patient with severe underlying diseases who regularly consumes dairy products, the clinical suspicion of this rare infection must be immediately evaluated. Listeriosis can be fatal despite effective antibiotic therapy, since it affects patients with severe underlying pathologies.     

The Effect of Intraperitoneal Catalase on Prevention of Peritoneal Adhesion Formation in Rats

The objective of our study was to investigate the efficacy of catalase in preventing the formation of peritoneal adhesions induced by cecal serosal laceration in rats. A research study was set up using a randomized complete block design. This study was performed in the Experimental Surgical Research Center, Kahramanmaras Sutcuimam University, Kahramanmaras, Turkey. Thirty Wistar albino rats were assigned to 3 groups of 10 animals each. The animals were anesthetized, a median laparotomy was performed, and the cecum was traumatized. In the final stages of surgery, the first group received 30,000 U of catalase intraperitoneally (ip) (catalase group), the second group received 2 mL of saline solution ip (isotonic group), and the last group received no treatment (control group). All rats were sacrificed on day 14. Adhesions were counted and blood samples were taken for measuring the catalase level. There were significant differences between the adhesion scores among all groups (p <. 05, Kruskal–Wallis test). The catalase group had significantly lower adhesion scores than the other groups (post hoc Mann–Whitney test). At day 14, blood catalase levels in the catalase group were significantly lower than in the other groups (p <. 05). We conclude that introduction of catalase into the peritoneal cavity during surgery inhibited adhesion formation.     

Expectation‐induced placebo responses fail to accelerate wound healing in healthy volunteers: results from a prospective controlled experimental trial

Placebo responses have been shown to affect the symptomatology of skin diseases. However, expectation‐induced placebo effects on wound healing processes have not been investigated yet. We analysed whether subjects' expectation of receiving an active drug accelerates the healing process of experimentally induced wounds. In 22 healthy men (experimental group, n = 11; control group, n = 11) wounds were induced by ablative laser on both thighs. Using a deceptive paradigm, participants in the experimental group were informed that an innovative ‘wound gel’ was applied on one of the two wounds, whereas a ‘non‐active gel’ was applied on the wound of the other thigh. In fact, both gels were identical hydrogels without any active components. A control group was informed to receive a non‐active gel on both wounds. Progress in wound healing was documented via planimetry on days 1, 4 and 7 after wound induction. From day 9 onwards wound inspections were performed daily accompanied by a change of the dressing and a new application of the gel. No significant differences could be observed with regard to duration or process of wound healing, either by intraindividual or by interindividual comparisons. These data document no expectation‐induced placebo effect on the healing process of experimentally induced wounds in healthy volunteers.