Validity of a novel ex vivo porcine liver perfusion model for studying haemostatic products.

Introduction: We developed a novel normothermic ex vivo porcine liver perfusion model with whole blood in order to have alternatives for animal experiments in the research and development of new local haemostatic agents. This study aims to assess the construct and content validity of this model.

Methods: In this study we performed two ex vivo experiments using nine livers and one in vivo experiment using six female Norsvin Topigs pigs: (1) ex vivo liver perfusion for establishing physiological blood parameters of the perfused liver and controlled heparinization, (2) ex vivo liver perfusion with a surgical injury and (3) a surgical liver injury in anaesthetized pigs with and without heparin.

Tubular collagen scaffolds with radial elasticity for hollow organ regeneration.

Unlabelled: Tubular collagen scaffolds have been used for the repair of damaged hollow organs in regenerative medicine, but they generally lack the ability to reversibly expand in radial direction, a physiological characteristic seen in many native tubular organs. In this study, tubular collagen scaffolds were prepared that display a shape recovery effect and therefore exhibit radial elasticity. Scaffolds were constructed by compression of fibrillar collagen around a star-shaped mandrel, mimicking folds in a lumen, a typical characteristic of empty tubular hollow organs, such as ureter or urethra.

Repeated remote ischemic preconditioning and isoflurane anesthesia in an experimental model of renal ischemia-reperfusion injury.

Background: In animal studies, remote ischemic preconditioning (RIPC) and anesthetic preconditioning are successful in reducing renal ischemia reperfusion injury (IRI), however the protective effect of RIPC may be improved by repeating the RIPC stimulus.

Methods: Sprague-Dawley rats underwent unilateral nephrectomy followed by 30 min of renal pedicle clamping. Animals were allocated into six groups: sham, control (IRI), RepISO (daily isoflurane anesthesia), RIPC (single dose isoflurane anesthesia and single dose RIPC), RepISO + RIPC (7-day isoflurane anesthesia and single dose RIPC) and RepISO + RepRIPC (7-day isoflurane anesthesia with 7-day RIPC).

Design of an elasticized collagen scaffold: A method to induce elasticity in a rigid protein.

Unlabelled: Type I collagen is widely applied as a biomaterial for tissue regeneration. In the extracellular matrix, collagen provides strength but not elasticity under large deformations, a characteristic crucial for dynamic organs and generally imparted by elastic fibers. In this study, a methodology is described to induce elastic-like characteristics in a scaffold consisting of solely type I collagen.

The Effect of Mycophenolate Mofetil on Early Wound Healing in a Rodent Model.

Background: Immunosuppressant agents are inevitable for solid organ recipients, but may have a negative effect on wound healing that is difficult to measure because of clinical use of a polydrug regime. The evidence on mycophenolate mofetil (MMF) is scarce and contradictory. This study aims to investigate the effect of MMF administration on wound healing.

Efficacy and Safety of Ultrapure Alginate-Based Anti-Adhesion Gel in Experimental Peritonitis.

Background: Intra-abdominal infection may lead to adhesion and abscess formation. An adhesion barrier can reduce these complications but also aggravate intra-peritoneal infection, causing the opposite effects. The fear of infection propagation has limited clinical adhesion barrier use in a contaminated or infected abdomen.

ARE INTRAVITREAL INJECTIONS WITH ULTRATHIN 33-G NEEDLES LESS PAINFUL THAN THE COMMONLY USED 30-G NEEDLES?

Purpose: This study investigated whether pain from intravitreal injections (IVIs) can be reduced by injecting with a 33-G needle instead of the commonly used 30-G needle. Additionally, several pain-related psychological factors were explored as predictors of outcome.

Methods: This randomized crossover trial included 36 patients who received injections with both needles in randomized order.

Diclofenac causes anastomotic leakage in the proximal colon but not in the distal colon of the rat.

Background: Nonsteroidal anti-inflammatory drugs have been associated with anastomotic leakage. It was studied if diclofenac affects anastomoses differently depending on the location in the gut.

Methods: Ninety-five rats were randomized to 6 groups with an anastomosis in either ileum (IL), proximal colon (PC), or distal colon (DC).

Serosal abrasion of bowel ends does not enhance anastomotic healing.

Background: Anastomotic leakage rates remain unacceptably high, warranting reconsideration of current anastomotic technique. Anastomotic healing may improve by abrading the serosal surface of bowel ends that are invertedly anastomosed, based on the concept that serosal damage evokes inflammatory adherent processes. It is studied if local abrasion leads to stronger anastomoses and reduces leakage.

Ultrapure alginate gel reduces adhesion reformation after adhesiolysis.

Purpose: Adhesiolysis at repeat surgery induces adhesion reformation which seems more virulent than development of de novo adhesions. We studied the effect of a new ultrapure alginate gel on adhesion reformation.

Methods: In 46 male Wistar rats, adhesion formation was induced using the cecal abrasion and peritoneal sidewall excision procedure.

Ultrapure alginate anti-adhesion gel does not impair colon anastomotic strength.

Background: Ultrapure alginate gel is promising in terms of adhesion prevention. Because anti-adhesive barriers have been shown to disturb healing of bowel anastomoses, the effect of ultrapure alginate gel on the repair of colon anastomoses was studied.

Materials And Methods: In 102 male Wistar rats, a 0.

Tacrolimus does not affect early wound healing in a rodent model of bowel anastomoses and abdominal wall closure.

Background: Use of immunosuppressant drugs has been associated with complications in wound healing. The calcineurin inhibitor tacrolimus is thought to have a relatively low complication rate, but preclinical research has yielded contradictory data, prompting the current comprehensive study.

Methods: Three groups of 33 male Wistar rats received a daily subcutaneous dose of 0,5, 2 or 5 mg/kg tacrolimus.

Carprofen for perioperative analgesia causes early anastomotic leakage in the rat ileum.

Background: There is increasing evidence that perioperative use of NSAIDs may compromise the integrity of intestinal anastomoses. This study aims to characterize the negative effects of carprofen on early anastomotic healing in the rat ileum.

Results: In 159 male Wistar rats an anastomosis was constructed in the ileum.

Paracetamol does not compromise early wound repair in the intestine or abdominal wall in the rat.

Background: Paracetamol is a cornerstone for perioperative pain relief. Its mechanism of action may include a local anti-inflammatory effect with inhibition of cyclooxygenase isoenzymes. The scarce literature available on its effects on wound healing consists of preclinical studies into the effect of paracetamol on healing of the musculoskeletal system.

The effect of fibrin glue on the early healing phase of intestinal anastomoses in the rat.

Purpose: Protecting the anastomotic integrity using suture or staple line reinforcement remains an important goal for ongoing research. The present comprehensive study aims to establish the effects of fibrin glue on the early phase of anastomotic healing in the rat intestine.

Methods: One hundred and eight young adult male Wistar rats underwent resection and anastomosis of both the ileum and colon.

Everolimus-induced loss of wound strength can be prevented by a short postoperative delay in its administration.

The use of mammalian target of rapamycin inhibitors coincides with an increased incidence of surgical complications. In previous experiments, serious negative effects of postoperative everolimus on anastomotic strength were found. This study aims to investigate if delayed drug administration can prevent loss of wound strength.

Intraoperative versus early postoperative intraperitoneal chemotherapy after cytoreduction for colorectal peritoneal carcinomatosis: an experimental study.

Background: Perioperative intraperitoneal chemotherapy is used as an adjunct to cytoreductive surgery (CS) for peritoneal carcinomatosis (PC) in order to prolong survival. Worldwide, hyperthermic intraperitoneal chemotherapy (HIPEC), early postoperative intraperitoneal chemotherapy (EPIC), and combinations of the two are used. It remains unclear which regimen is most beneficial.

Hyperthermia and intraperitoneal chemotherapy for the treatment of peritoneal carcinomatosis: an experimental study.

Objective: Hyperthermic intraperitoneal chemotherapy (HIPEC) with mitomycin C can improve survival if used as an adjunct to cytoreductive surgery (CS) for treatment of peritoneal carcinomatosis (PC). It remains unclear if both hyperthermia and chemotherapy are essential for the reported survival benefit.

Methods: Eighty WAG/Rij rats were inoculated intraperitoneally with the rat colon carcinoma cell line CC-531.

Peritoneal cytokines predict mortality after surgical treatment of secondary peritonitis in the rat.

Background: The study aimed to analyze if peritoneal cytokine levels can predict survival in an experimental model for peritonitis. Early identification of patients most at risk for adverse outcomes would facilitate the decision for aggressive therapy in order to maximally exploit their chance for survival.

Study Design: Peritonitis was induced by intraperitoneal injection of a feces/bacteria mixture in 175 rats.

Persistent effects of everolimus on strength of experimental wounds in intestine and fascia.

The introduction of mTOR-inhibitors in transplantation surgery has been associated with an increase in wound complications. We have previously reported a massive negative effect of everolimus on anastomotic strength in rat intestine at 7 days postoperatively. Because it is clinically important to know if this effect persists and occurs generally, repair in both intestine and abdominal wall has been investigated over a period of 4 weeks.

Reduction of oxygenation and blood flow in pedicled bowel segments in the rat and its consequences for anastomotic healing.

Purpose: Experimental studies indicate that perioperative hypoperfusion impairs anastomotic healing. In bowel surgery, the part of bowel that will be anastomosed is often pedicled, leaving the blood supply dependent on the marginal artery only. Little is known about the blood supply in such a segment, and whether anastomotic strength is affected when flow would be reduced.

Tissue-type plasminogen activator prevents abscess formation but does not affect healing of bowel anastomoses and laparotomy wounds in rats with secondary peritonitis.

Background: Intra-abdominal application of recombinant tissue-type plasminogen activator (rtPA) can decrease the rate of abscess formation in a rat peritonitis model. Before using rtPA clinically, its effects on healing of bowel anastomoses and laparotomy wounds should be investigated.

Methods: Peritonitis was induced in 148 male Wistar rats via intra-abdominal injection of a feces/bacteria mixture.

Intercellular adhesion molecule-1 and gelatinase expression in human peritoneal mesothelial cells during propagation in culture.

Mesothelial cells are involved in a variety of biological processes, which include the formation of peritoneal adhesions. The cultures of human peritoneal mesothelial cells comprise an important tool to investigate the behavior and functions of mesothelial cells. Very little is known about the differences among mesothelial cells isolated from different sources and about the changes in specific functions as caused by cell propagation in vitro or that result from storage of cells at low temperatures.

Everolimus interferes with healing of experimental intestinal anastomoses.

Background: Although clinical data suggest its existence, little is known about the effect of rapamycin derivatives on wound repair. This study aims to delineate the influence of the mammalian target of rapamycin inhibitor everolimus on wound healing in the rat intestine.

Methods: Four groups of 26 male Wistar rats received everolimus in daily oral dosages of 0 (controls), 0.

Changes in gelatinase activity in the gastrointestinal tract after anastomotic construction in the ileum or colon.

Purpose: The strength of the uninjured and anastomosed intestinal wall is determined by its submucosal connective tissue. Matrix degradation by matrix metalloproteinases may result in loss of strength. It is known that anastomotic construction leads to up-regulation of matrix metalloproteinase activity in the wound area, but no quantitative data are available as to the extent of this effect throughout the intestinal wall.