Anastomotic Tissue Research Articles

1339 Gastro-Colic Fistula: A Delayed Complication of Whipple's Procedure for Tropical Pancreatitis

INTRODUCTION: Gastrointestinal (GI) fistula is a serious condition that can lead to electrolyte disturbance, severe debility and even death. It occurs as a complication of gastrointestinal surgery mostly involving malignancies. We present a case of a gastro-colic fistula (GCF) occurring six years after Whipple's procedure. CASE DESCRIPTION/METHODS: A 58 years old Guyanese male with current alcohol abuse was admitted for 2 months of diarrhea. He reported more than 2 dozen watery bowel movements a day including nocturnal episodes, fecal incontinence, chills and a 15 lbs weight loss. Lab work showed significant hypoalbuminemia, hypokalemia and normal anion gap metabolic acidosis. He reported a history of tropical pancreatitis complicated by acute necrotizing pancreatitis followed by Whipple's procedure 6 years ago. Patient underwent CT abdomen which showed diffuse wall thickening of the ascending colon while colonoscopy revealed circumferential ulcerated mucosa in the same area. The colonoscope was not advanced further due to high risk of perforation. Biopsies from ulcer base and margin showed benign colonic mucosa with regenerative changes. An EGD was performed that revealed a 3 cm peri-anastomotic gastric ulcer and a large GCF in ulcer base. Fecal material was found in stomach and fistula was easily traversed with gastroscope. Patient was put on TPN and underwent exploratory laparotomy with partial greater omentectomy, distal gastrectomy with Roux-en-Y gastrojejunostomy, transverse colectomy with end colostomy, long Hartmann's pouch and a partial small bowel resection. Post-procedure he was slowly advanced to a regular diet with resolution of his diarrhea. DISCUSSION: GCF happens most commonly in surgeries involving GI malignancies. Imaging of choice is barium enema with barium seen in the stomach via a pressure gradient created from the colon to the stomach. GCF can be diagnosed endoscopically but may be missed if the fistula opening is small or obscured by adjacent mucosal changes as we encountered during colonoscopy in this case. Risk factors for developing GCF after Whipple's procedure include infection, sepsis, breakdown of intestinal anastomosis due to ischemia, tension in anastomotic tissue, distal obstruction hypoproteinemia, radiation injury and underlying IBD. Controlling fistula output by keeping patient NPO, proton pump inhibitors and maintaining adequate nutrition are key factors in healing GCF. Endoscopic or surgical approaches for fistula closure should be considered on individual basis.

Mucus Microbiome of Anastomotic Tissue During Surgery Has Predictive Value for Colorectal Anastomotic Leakage.

The aim of the present study is to investigate the association of gut microbiota, depending on treatment method, with the development of colorectal anastomotic leakage (AL). AL is a major cause for morbidity and mortality after colorectal surgery, but the mechanism behind this complication still is not fully understood. Bacterial DNA was isolated from 123 "donuts" of patients where a stapled colorectal anastomosis was made and was analyzed using 16S MiSeq sequencing. In 63 patients, this anastomosis was covered with a C-seal, a bioresorbable sheath stapled to the anastomosis. In non-C-seal patients, AL development was associated with low microbial diversity (P = 0.002) and correspondingly with a high abundance of the dominant Bacteroidaceae and Lachnospiraceae families (P = 0.008 and 0.010, respectively). In C-seal samples, where AL rates were slightly higher (25% vs 17%), an association with the gut microbiota composition was almost undetectable. Only a few opportunistic pathogenic groups of low abundance were associated with AL in C-seal patients, in particular Prevotella oralis (P = 0.007). AL in patients without a C-seal can be linked to the intestinal microbiota, in particular with a low microbial diversity and a higher abundance of especially mucin-degrading members of the Bacteroidaceae and Lachnospiraceae families. In C-seal patients, however, it seems that any potential protective benefits or harmful consequences of the gut microbiota composition in regard to wound healing are negated, as progression to AL is independent of the initially dominant bacterial composition.

Colonic anastomosis can be protected from ischemia reperfusion injury with intra-peritoneal Montelukast treatment

Ischemia reperfusion injury is unavoidable in the setting of transplantation and may lead to primary dysfunction of the transplanted organ. Similarly, intestinal ischemia reperfusion injury may have deleterious effects causing intestinal failure. Montelukast is a selective reversible cysteinyl-leukotriene type 1 receptor antagonist used in clinical practice for its anti-inflammatory effects. In this study, we investigated the effects of Montelukast on colon anastomosis performed after intestinal ischemia reperfusion injury. 40 adult male Wistar Albino rats were used. All rats underwent intestinal ischemia reperfusion injury. Afterwards, the entire group was divided into two for either right or left colonic resection and anastomosis. Rats in the control groups were given intra-peritoneal normal saline for 1 week while the animals in the treatment groups were given intra-peritoneal Montelukast (10mg/kg; 1ml). All animals were subjected to ischemia reperfusion injury followed by either right or left colonic segmental resection and anastomosis in the first day of the experiment. On postoperative day 7 adhesion scoring, anastomotic bursting pressure, anastomotic tissue hydroxyproline content were assessed for all groups. Significant differences were detected in adhesion scores between the treatment and control groups regardless of the colonic resection site. Anastomotic bursting pressures and hydroxyproline content of the anastomotic sites were significantly higher in the treatment groups when compared with the control groups. Anastomotic tissues treated with Montelukast showed more prominent vascularization in histopathological examinations. Montelukast has a potential to attenuate the detrimental effects of ischemia reperfusion injury on intestinal anastomosis.

Optimized force range of magnetic compression anastomosis in dog intestinal tissue

BackgroundMagnetic compression anastomosis (MCA) is a commonly used anastomosis method. MCA was widely used in tissues repair, gastroenterostomy, choledochoenterostomy, and so on. It is safer and more effective than stapler and manual surgical suturing. However, there are few detailed studies on the biomechanical characteristics and tissue transformation mechanisms of the anastomosis process. In this research, taking intestinal tissue as research object, we need to determine an optimal compressive force range to provide a biomechanical reference for the design of anastomats. MethodsMagnets with different magnetic force groups (2.06, 3.21, 6.27, 13.3 and 19.2 N) were implanted into each dog to form intestinal tissue side-to-side anastomoses. Five dogs were euthanized on each of postoperative day 1, day 3, and day 7. Anastomoses were then harvested and compared with respect to postoperative complications, histology and tear-resistance load capacity (TRLC). ResultsThe TRLC of anastomotic tissue formed by magnets with different magnetic forces differed markedly, but with the tissue growth, the TRLC differences between groups were decreased. Histology of anastomotic tissue showed that, in the initial stage, the anastomoses compressed by 2.06-N magnets did not form effectively, while the leakage appeared in the anastomoses compressed by 19.2-N magnets, in the rest groups, with magnetic force increasing, severity of ischemia and necrosis of compressed tissue increased and healing speed of anastomotic tissue improved. In the late stage, the influence of magnetic force for anastomotic tissue was gradually diminished. ConclusionsThe magnetic force applied on the magnetic compression anastomats affects the necrosis speed of compressed tissue and the healing speed of anastomotic tissue. The optimal compressive force range for intestinal compression anastomosis is 6.27 N to 13.3 N, and the actual optimal compression pressure is 79.8 kPa - 169 kPa. Level of EvidenceMagnetic compression anastomosis (MCA) is a commonly used anastomosis method. MCA was widely used in tissues repair, gastroenterostomy, choledochoenterostomy, and so on. It is safer and more effective than stapler and manual surgical suturing. However, there are few detailed studies on the biomechanical characteristics and tissue transformation mechanisms of the anastomosis process. In this research, taking intestinal tissue as research object, we need to determine an optimal compressive force range to provide a biomechanical reference for the design of anastomats.

Recurring Anastomotic Leak—A Prospective Clinicopathological Investigation of a Distinct Disease Pattern

BackgroundIntestinal anastomotic insufficiency (AI) is a common problem in visceral surgery associated with overexpression of matrix metalloproteinases (MMPs). In some patients it occurs more than once. The etiology of recurring anastomotic insufficiency (RAI) is not understood yet and should be addressed as an independent disease entity. Materials and methodsThirty nine consecutive patients with AI were treated at our university center and were included in this prospective study. Clinical data were evaluated by correlative statistical analysis to identify independent risk factors for RAI. Patients were divided in two groups: 18 patients had a single operative revision until restoration (group SAI), and 21 patients had two or more revisions (group RAI). Anastomotic tissue samples as well as untouched bowel wall were collected during reoperations for analysis of MMPs and tissue inhibitor of metalloproteinases (TIMP2). Clinical data were correlated with pathological observations. ResultsSignificant differences of clinical and molecular pathological data were found between the two groups. Transfusion of red blood cells until the first reoperation and alcohol abuse led to RAI and were the only independent risk factors for RAI in multivariate analysis. Overexpression of MMP-8, -9, and -13 in anastomotic tissue correlated with the administration of red blood cells during initial operation. Reduced expression of TIMP2 was frequent in nearly all patients without differences throughout the subgroups. ConclusionsRAI seems to have an independent disease pattern. Transfusion of blood products is not only a known risk factor for AI but seems to significantly disturb the anastomotic healing process leading to RAI.

Biomechanical and Performance Evaluation of Magnetic Elliptical-Ring Compressive Anastomoses

BackgroundAfter magnetic compressive anastomosis, anastomat passage through the narrow channels of the digestive tract is difficult owing to the device's large volume. Such passage can lead to mechanical damage to the digestive tract or anastomat's unstable excretion time. This article presents a new magnetic compressive anastomotic approach. MethodsA magnetic elliptical-ring compressive anastomat was designed and evaluated for placement and passage in vitro. Nine young adult dogs underwent laparotomy with intestinal tissue side-to-side anastomosis. Four different groups of magnetic compressive anastomats of two different magnetic force levels (20 N or 30 N) and shapes (round or elliptical) were implanted into each dog simultaneously. Three dogs were euthanized on each of postoperative day 1, day 4, and day 7. Anastomoses were then compared with respect to histology and tensile fracture force. ResultsThe magnetic elliptical-ring compressive anastomat was functional but produced less obstruction compared to its round counterpart during passage through the esophagus and intestine. Nine dogs underwent successful surgery and harvesting of 30 total anastomoses. Histology of anastomotic tissue showed that, along the newly formed tunnel connecting the two sides of anastomotic tissues, compressed tissues became thinner and fell off, and initial anastomoses formed on the seventh postoperative day. There were large differences in tensile fracture force among the anastomoses formed by magnets with different magnetic forces of the same structure. However, the magnetic compressive anastomat structure did not affect anastomotic repair during magnetic compression anastomosis. ConclusionsThe magnetic elliptical-ring compressive anastomat is an efficient anastomotic device that can be used easily and with good passage. The device has good biomechanical properties and can be used with endoscopy to reduce operative time.

Comparison of the effects of two different marine-derived omega-3 fatty acid sources, krill oil, and fish oil, on the healing of primary colonic anastomoses after colectomy applied Wistar albino rat model.

Oils from marine organisms have a different fatty acid composition. Fish oil (FO) has a high content of eicosapentaenoic and docosahexaenoic acids esterified to triacylglycerols; while in krill oil (KO), fatty acids are primarily esterified to phospholipids. This study aimed to compare the efficacy of two different, marine-derived omega-3 fatty acid sources in the wound healing of colon anastomoses rat model. For the study, we used 42 male Wistar albino rats. The rats were divided into six groups with seven rats in each group-CO3: left colonic anastomosis (control group), sacrificed on the third day; KO3: left colonic anastomosis + oral KO, sacrificed on the third day; FO3: left colonic anastomosis + oral FO, sacrificed on the third day; CO7: left colonic anastomosis (control group), sacrificed on the seventh day; KO7: left colonic anastomosis + oral KO, sacrificed on the seventh day; FO7: left colonic anastomosis + oral FO, sacrificed on the seventh day. Peritoneal adhesions, anastomotic bursting pressures, hydroxyproline levels, and histological examination of the anastomotic tissue were evaluated. On day 7, bursting pressure and hydroxyproline measurements of the KO group was significantly higher than the FO group (p=0.012; p=0.002, respectively). Also, on day 7, a statistically significant difference was observed between the groups according to inflammatory cell infiltration, fibroblast activity, neoangiogenesis, and collagen deposition in favor of the KO group (p=0.023; p=0.028; p=0.016; p=0.012, respectively). Both KO and FO supplementation in patients before colorectal surgery may reduce some risk of anastomotic leakage; and KO might be a better alternative and excellent omega-3 source.

Effects of Ghrelin on the Oxidative Stress and Healing of the Colonic Anastomosis in Rats

BackgroundAnastomotic leakage is the deadliest complication of colonic procedures. Ghrelin is an orexigenic hormone with potent actions on growth hormone release and functions in the processes of growth, tissue inflammation, repair, and oxidative stress. We evaluated the hypothesis that the exogenous administration of ghrelin causes beneficial effects on the healing of colonic anastomosis. Materials and methodsSixty-four male Wistar rats were randomly assigned to eight subgroups receiving postoperative intraperitoneal administration of ghrelin (23 μg/kg/d) or saline after a colonic anastomosis. The anastomotic tissue was evaluated on the third, seventh, and 14th postoperative days. Anastomotic bursting pressure, histological parameters, hydroxyproline content, and tissue oxidative stress markers were compared. ResultsThere was a significant increase in the mean anastomotic bursting pressure in the ghrelin subgroup on the seventh postoperative day (P = 0.035). Histological evaluation demonstrated a significant difference in the neutrophilic infiltrate (P = 0.035) on the third and 14th d and in apoptosis (P = 0.004), granulation tissue (P = 0.011) and peritoneal inflammation (P = 0.014) on the 14th postoperative day. There was a statistically significant increase in the hydroxyproline content in the ghrelin subgroup on the 14th postoperative day (P = 0.043). There were significant differences in the nitrite tissue levels (P = 0.021) on day 3 and in reactive oxygen species (P = 0.012) on day 14. ConclusionsThe administration of ghrelin had beneficial anti-inflammatory and antioxidant effects, increasing the resistance of the anastomosis and the hydroxyproline tissue content in the postoperative period.

FA05.03: EFFECT OF EPHEDRINE ON GASTRIC CONDUIT PERFUSION MEASURED BY LASER SPECKLE CONTRAST IMAGING (LSCO) AFTER ESOPHAGECTOMY: A PROSPECTIVE IN-VIVO COHORT STUDY

Abstract Background Compromised perfusion due to ligation of arteries and veins in esophagectomy with gastric tube reconstruction often (5–20%) results in necrosis and anastomotic leakage, which relate to high morbidity and mortality (3–4%). Ephedrine is used widely in anesthesia to treat intra-operative hypotension and may improve perfusion by the increase of cardiac output (CO) and mean arterial pressure (MAP). This study tests the effect of ephedrine on perfusion of the future anastomotic site of the gastric conduit, measured by Laser Speckle Contrast Imaging (LSCI). Methods This prospective, observational, in-vivo pilot study includes 26 patients undergoing esophagectomy with gastric tube reconstruction from October 2015 to June 2016 in the Academic Medical Center (Amsterdam). Perfusion of the gastric conduit was measured with LSCI directly after reconstruction and after an increase of MAP by ephedrine 5 mg. Perfusion was quantified in flux (LSPU) in four perfusion locations, from good perfusion (base of the gastric tube) towards decreased perfusion (fundus). Intra-patient differences before and after ephedrine in terms flux were statistically tested for significance with a paired t-test. Results LSCI was feasible to image gastric microcirculation in all patients. Flux (LSPU) was significantly higher in the base of the gastric tube (791 ± 442) compared to the fundus (328 ± 187) (P < 0.001). After administration of ephedrine, flux increased significantly in the fundus (P < 0·05) measured intra-patients. Three patients developed anastomotic leakage. In these patients, the difference between measured flux in the fundus compared to the base of the gastric tube was high. Conclusion This study presents the effect of ephedrine on perfusion of the gastric tissue measured with LSCI in terms of flux (LSPU) after esophagectomy with gastric tube reconstruction. We show a small but significant difference between flux measured before and after administration of ephedrine in the future anastomotic tissue (313 ± 178 vs. 397 ± 290). We also show a significant decrease of flux towards the fundus. Disclosure All authors have declared no conflicts of interest.

Oral Polyphosphate Suppresses Bacterial Collagenase Production and Prevents Anastomotic Leak Due to Serratia marcescens and Pseudomonas aeruginosa.

The objective of this study was to determine the effect of polyphosphate on intestinal bacterial collagenase production and anastomotic leak in mice undergoing colon surgery. We have previously shown that anastomotic leak can be caused by intestinal pathogens that produce collagenase. Because bacteria harbor sensory systems to detect the extracellular concentration of phosphate which controls their virulence, we tested whether local phosphate administration in the form of polyphosphate could attenuate pathogen virulence and prevent leak without affecting bacterial growth. Groups of mice underwent a colorectal anastomosis which was then exposed to collagenolytic strains of either Serratia marcescens or Pseudomonas aeruginosa via enema. Mice were then randomly assigned to drink water or water supplemented with a 6-mer of polyphosphate (PPi-6). All mice were sacrificed on postoperative day 10 and anastomoses assessed for leakage, the presence of collagenolytic bacteria, and anastomotic PPi-6 concentration. PPi-6 markedly attenuated collagenase and biofilm production, and also swimming and swarming motility in both S. marcescens and P. aeruginosa while supporting their normal growth. Mice drinking PPi-6 demonstrated increased levels of PPi-6 and decreased colonization of S. marcescens and P. aeruginosa, and collagenase activity at anastomotic tissues. PPi-6 prevented anastomotic abscess formation and leak in mice after anastomotic exposure to S. marcescens and P. aeruginosa. Polyphosphate administration may be an alternative approach to prevent anastomotic leak induced by collagenolytic bacteria with the advantage of preserving the intestinal microbiome and its colonization resistance.

Letter to the Editor for “Mucus Microbiome of Anastomotic Tissue During Surgery Has Predictive Value for Colorectal Anastomotic Leakage”

Letter to the Editor for “Mucus Microbiome of Anastomotic Tissue During Surgery Has Predictive Value for Colorectal Anastomotic Leakage”

Novel de novo synthesized phosphate carrier compound ABA-PEG20k-Pi20 suppresses collagenase production in Enterococcus faecalis and prevents colonic anastomotic leak in an experimental model.

Previous work has demonstrated that anastomotic leak can be caused by collagenolytic bacteria such as Enterococcus faecalis via an effect on wound collagen. In humans, E. faecalis is the organism cultured most commonly from a leaking anastomosis, and is not routinely eliminated by standard oral or intravenous antibiotics. Novel strategies are needed to contain the virulence of this pathogen when present on anastomotic tissues. Polyphosphorylated polymer ABA-PEG20k-Pi20 was tested in mice for its ability to prevent anastomotic leak caused by collagenolytic E. faecalis. The study design included a distal colonic resection and anastomosis followed by introduction of E. faecalis to anastomotic tissues via enema. Mice were assigned randomly to receive either ABA-PEG20-Pi20 or its unphosphorylated precursor ABA-PEG20k in their drinking water. The development of anastomotic leak was determined after the animals had been killed. Overnight incubation of two different E. faecalis collagenolytic strains with 2 mmol/l of ABA-PEG20k-Pi20 led to near complete inhibition of collagenase production (from 21 000 to 1000 and from 68 000 to 5000 units; P < 0·001; 6 samples per group) without suppressing bacterial growth. In mice drinking 1 per cent ABA-PEG20k-Pi20, the phosphate concentration in the distal colonic mucosa increased twofold and leak rates decreased from eight of 15 to three of 15 animals (P < 0·001). In mice drinking ABA-PEG20k-Pi20, the percentage of collagenolytic colonies among E. faecalis populations present at anastomotic tissue sites was decreased by 6-4800-fold (P = 0·008; 5 animals). These data indicate that oral intake of ABA-PEG20k-Pi20 may be an effective agent to contain the virulence of E. faecalis and may prevent anastomotic leak caused by this organism. Clinical relevance Progress in understanding the pathogenesis of anastomotic leak continues to point to intestinal bacteria as key causative agents. The presence of pathogens such as Enterococcus faecalis that predominate on anastomotic tissues despite antibiotic use, coupled with their ability to produce collagenase, appears to alter the process of healing that leads to leakage. Further antibiotic administration may seem logical, but carries the unwanted risk of eliminating the normal microbiome, which functions competitively to exclude and suppress the virulence of pathogens such as E. faecalis. Therefore, non-antibiotic strategies that can suppress the production of collagenase by E. faecalis without affecting its growth, or potentially normal beneficial microbiota, may have unique advantages. The findings of this study demonstrate that drinking a phosphate-based polymer can achieve the goal of preventing anastomotic leak by suppressing collagenase production in E. faecalis without affecting its growth.

Effect of ephedrine on gastric conduit perfusion measured by laser speckle contrast imaging after esophagectomy: a prospective in vivo cohort study.

Compromised perfusion due to ligation of arteries and veins in esophagectomy with gastric tube reconstruction often (5-20%) results in necrosis and anastomotic leakage, which relate to high morbidity and mortality (3-4%). Ephedrine is used widely in anesthesia to treat intraoperative hypotension and may improve perfusion by the increase of cardiac output and mean arterial pressure (MAP). This study tests the effect of ephedrine on perfusion of the future anastomotic site of the gastric conduit, measured by laser speckle contrast imaging (LSCI). This prospective, observational, in vivo pilot study includes 26 patients undergoing esophagectomy with gastric tube reconstruction from October 2015 to June 2016 in the Academic Medical Center (Amsterdam). Perfusion of the gastric conduit was measured with LSCI directly after reconstruction and after an increase of MAP by ephedrine 5 mg. Perfusion was quantified in flux (laser speckle perfusion units, LSPU) in four perfusion locations, from good perfusion (base of the gastric tube) toward decreased perfusion (fundus). Intrapatient differences before and after ephedrine in terms flux were statistically tested for significance with a paired t-test. LSCI was feasible to image gastric microcirculation in all patients. Flux (LSPU) was significantly higher in the base of the gastric tube (791±442) compared to the fundus (328±187) (P<0.001). After administration of ephedrine, flux increased significantly in the fundus (P<0.05) measured intrapatients. Three patients developed anastomotic leakage. In these patients, the difference between measured flux in the fundus compared to the base of the gastric tube was high. This study presents the effect of ephedrine on perfusion of the gastric tissue measured with LSCI in terms of flux (LSPU) after esophagectomy with gastric tube reconstruction. We show a small but significant difference between flux measured before and after administration of ephedrine in the future anastomotic tissue (313±178 vs. 397±290). We also show a significant decrease of flux toward the fundus.

Assessment of MMP-2/-9 expression by fluorescence endoscopy for evaluation of anastomotic healing in a murine model of anastomotic leakage.

BackgroundDisturbance of intestinal wound closure leads to insufficient anastomotic healing and is associated with considerable morbidity following colorectal resections. Matrix metalloproteinases (MMPs) play a crucial role in regulation of wound closure. Here fluorescence endoscopy was evaluated for assessment of MMP-2/-9 expression during failed intestinal anastomotic healing.MethodsDistal colonic anastomoses were performed as a model for disturbed healing in 36 Balb/c mice. Healing was evaluated endoscopically, macroscopically, and histologically after 1, 3 and 5 days. For detection of MMP-2/-9 expression fluorescence endoscopy (FE) was used following i.v.-administration of a Cy5.5-labeled MMP-2/-9 specific tracer. FE was complemented by quantification of the fluorescence signal using the MS-FX PRO Optical Imaging System. An overall leakage score was calculated and correlated with the results of FE.ResultsWith increasing incidence of anastomotic leakage from POD1 (17%) to POD5 (83%) the uptake of the MMP tracer gradually increased (signal-to-noise ratio (SNR), POD1: 17.91 ± 1.251 vs. POD3: 30.56 ± 3.03 vs. POD5: 44.8 ± 4.473, P<0.0001). Mice with defective anastomotic healing showed significantly higher uptake compared to non-defective (SNR: 37.37± 3.63 vs. 26.16± 3.635, P = 0.0369). White light endoscopy and FE allowed evaluation of anastomotic healing and visualization of mucosal MMPs in vivo. Using FE based detection of MMPs in the anastomosis, an overall positive predictive value of 71.4% and negative predictive value of 66.6% was calculated for detection of anastomotic leakage.ConclusionDuring disturbed anastomotic healing increased expression of MMP-2/-9 was observed in the anastomotic tissue. Fluorescence endoscopy for detection of MMP-2/-9 during the healing process might be a promising tool for early identification of anastomotic leakage.

The effects of NF-κB signal pathway on the process of anastomotic stricture after the radical resection of esophageal carcinoma

The aim of this article is to identify the relationship between the nuclear factor κB (NF-κB) signal pathway expression and the anastomotic stricture. It particularly focuses on the expression of p65, bcl-2, and cIAP-1 in the anastomotic stricture formation after radical resection of esophageal cancer. A total of 82 esophageal squamous carcinoma patients who had undergone esophagectomy by Ivor Lewis procedure were enrolled in the study. Tissues were collected from the patients who developed the anastomotic stricture after the operation, while para anastomotic tissues served as the control. The protein expression of p65, bcl-2, and cIAP-1 was analyzed by immunohistochemistry and western blot analyses, while the messenger RNA (mRNA) levels of p65, bcl-2, and cIAP-1 were evaluated by reverse transcription polymerase chain reaction (RT-PCR). The results showed that lower expression of p65, bcl-2, and cIAP-1 proteins was observed in the para anastomotic tissue; in the esophageal stricture’s tissue, the expression of these proteins was significantly higher ( P &lt; 0.05). The mRNA levels of P56, bcl-2, and cIAP-1 in the stricture tissue were remarkably increased ( P &lt; 0.05) compared with the para anastomotic tissues, and the mRNA levels in the sample of grade 3 dysphagia were higher ( P &lt; 0.05) than the levels of grade 1 and 2. In the normal esophageal epithelial cell of stricture patients was upregulated compared with that of no stricture patients. We can confirm that the anastomotic stricture has the relationship with the NF-κB signal pathway. The bcl-2 and cIAP-1, located downstream of NF-κB signal pathway, could be a new preventive and therapeutic target for the anastomotic stricture.

Effects of thyroid hormone supplementation on oxidative stress after sleeve gastrectomy in rats

Aim: Sleeve gastrectomy has been used for the surgical treatment of morbid obesity. The aim of the present study was to determine the effects of triiodothyronine supplementation on oxidative stress parameters in anastomotic tissue level. Material and Methods: Twenty-four male Wistar albino rats were divided into control (n:12), and experimental (n:12) groups and underwent sleeve gastrectomy. Experimental group rats received a single dose of triiodothyronine (400 mg/100 g) in the operation day. Rats were sacrificed on postoperative day 7. Serum thyroid hormones were analysed. The supernatants were used to measure total oxidant status, total antioxidant status, nitric oxide and malondialdehyde levels. All tissue parameters were analysed by spectrophotometric methods. Oxidative stress index values were calculated. Results: Thyroid stimulating hormone levels in both the control and triiodothyronine group did not significantly change on the 7th postoperative day (p=0.663). Free triiodothyronine levels were significantly higher in triiodothyronine group rats than in control group rats (triiodothyronine vs control: p=0.004). Although total oxidant status levels did not altered by thyroid hormone treatment (p>0.05), total antioxidant status levels significantly decreased (p0.05). Tissue nitric oxide levels were also similar in both groups (p>0.05). Malondialdehyde levels increased in triiodothyronine given rats compared with the control group (p

Upregulation of VEGFR1 in a rat model of esophagogastric anastomotic healing

Introduction: Anastomotic leakage after gastrointestinal surgery is a significant cause of morbidity and mortality. Esophagogastric and colorectal anastomoses are vulnerable to leakage. Extended knowledge of growth factors and their receptors is needed to understand anatomic healing.Methods: The expression pattern of vascular growth factor receptor (VEGFR1-3), epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFRα/β) and keratinocyte growth factor receptor (KGFR) were analyzed by semiquantitative-PCR in the rat intestinal tract and in esophagogastric anastomosis 5d after surgery.Results: VEGFR1, VEGFR2, EGFR, KGFR and PDGFRα expression was observed throughout the intestinal tract including esophagus, stomach, small bowl and colon. VEGFR3 was not found in gastric samples and PDGFRβ expression was not detected in the small bowl.Semiquantitative analyses of the VEGFR1, PDGFRα and EGFR expression in esophagogastric anastomotic tissues revealed a 2-fold upregulation of the VEGFR1 in gastric samples, while no change was observed in the esophageal anastomotic side.Conclusion: Our results revealed a distinct expression pattern of the investigated growth factor receptors in rat intestinal tract. Showing higher expression levels of growth factor receptors at the gastric anastomotic tissue at the fifth postoperative day suggests a different contribution of the gastric and the esophageal side to the anastomotic healing.

Long-term anti-inflammatory efficacy in intestinal anastomosis in mice using silver nanoparticle-coated suture

BackgroundIn our previous study, we coated silver nanoparticles (AgNPs) onto the surface of absorbable braided suture using layer-by-layer deposition and demonstrated significant anti-inflammatory property during the early phase of intestinal anastomosis healing in mice. The present study aimed to further investigate the long-term anti-inflammatory efficacy. MethodsAgNP-coated suture, antibiotic coated suture, and normal suture were respectively used for single layered, interrupted intestinal anastomosis. The anastomotic segments in each group were harvested on day 14, day 21, and day 28 postoperation and investigated for the degree of inflammation by cell infiltration and expression of cytokines as well as collagen deposition. ResultsWhen compared with the control groups, the AgNP-coated suture group showed better histological appearance in the intestinal anastomotic segments at each time point. Immunohistochemistry staining and quantitative evaluation further indicated less macrophage infiltration and decreased production of IL-6, IL-10, and TNF-α (p<0.05). Masson staining showed normal collagen deposition and remodeling at intestinal anastomotic tissue in the AgNP-coated suture group. ConclusionOur study shows that AgNP-coated suture provides better long-term anti-inflammatory efficacy and ideal tissue remodeling in intestinal anastomosis. Despite these findings, clinical trials are still needed for evaluation before medical application.

Lack of evidence for tissue hypoxia as a contributing factor in anastomotic leak following colon anastomosis and segmental devascularization in rats.

Current surgical dogma dictates that tissue ischemia and hypoxia are major contributing factors in anastomotic leak despite scant evidence. The aim of this study was to determine if tissue hypoxia is a feature of anastomotic leakage in rats following colon resection and segmental devascularization. Rats were randomly assigned to undergo sham operation, segmental colon devascularization alone, colectomy alone, or segmental devascularization plus colectomy. Tissue hypoxia present at the colon anastomosis site across the various treatment groups was determined at sacrifice on postoperative day 6. Pimonidazole HCl was injected 30min prior to sacrifice. Anastomotic tissues were examined and scored for healing versus leakage using an anastomotic healing score (AHS). Collagen content, hypoxia, enteric smooth muscle and periendothelial stromal patterning, and apoptosis were evaluated histologically. No differences in tissue hypoxia were noted in the 16% of anastomotic tissues with poor healing compared to the remaining 84% of rats whose anastomoses healed well. No significant changes were found in cell death in the submucosa of any group. Consistent with previous findings, poor healing was associated with lower collagen content. Submucosal thickness correlated with increased arteriole diameter (R 2=0.25, p<0.005). These results demonstrate that tissue hypoxia is not a distinctive feature of anastomotic tissues that fail to heal and leak, even when their blood supply is interrupted. These findings suggest that compensatory factors may mitigate the effects of ischemia and hypoxia during healing of anastomotic tissues and that the process of leakage involves factors beyond their acute effects.

Tannin-based adhesive for protection of colonic anastomosis in the open abdomen

This study was aimed to evaluate the effect of tannin acid- polyethylene glycol (TP) adhesive on the wound healing process of primary colonic anastomosis in the open abdomen (OA). Adhesion strength test, degradation and hemostatic ability of TP were investigated. In a rat model, after standard colonic anastomoses, rats were divided into three groups: OA group; OA + FG (fibrin glue) group; OA + TP group. Five days after surgery, body weight, anastomotic bursting pressure (ABP), and histology of anastomotic tissue were evaluated. Performance of adhesion strength and hemostatic ability of TP was better than that of FG. The weight of TP decreased by over 50% after 11-day incubation. All rats survived well after surgery. Compared to OA group and OA + FG group, OA + TP group showed a significant improvement in body weight, ABP and healing state. Application of TP adhesive, used as an auxiliary treatment of colonic anastomosis operation, improved the wound strength and promoted the anastomotic healing after OA.