Infliximab's influence on anastomotic strength and degree of inflammation in intestinal surgery in a rabbit model

Impact of anti-TNF agents in postoperative complications in Crohn's disease: a review

The real impact of biological therapy (anti-TNF agents) in abdominal operations secondary to Crohn's disease is a matter of debate in the international literature. Several studies demonstrated that there can be an increase in postoperative complications in patients previously treated with these agents. On the other hand, the majority of studies published over the last years question this effect, and did not demonstrate any relationship between biologics and outcomes related to surgical postoperative complications. Some meta-analyses were published, with different outcomes and different conclusions. Experimental studies in animals were also recently published, with opposite results, despite similar methodology. In this review, the authors resume all the relevant papers in the international literature with respect to the theme, and demonstrate the heterogeneity of the studies, as well as the disparity of their results and outcomes. The real impact of anti-TNF agents on postoperative complications in Crohn's disease is still controversial, and needs to be better elucidated. Controlled trials must be performed to better address this issue.

Risk of postoperative complications among ulcerative colitis patients treated preoperatively with vedolizumab: a matched case-control study

Background

Although biologic agents have revolutionized the medical management of severe ulcerative colitis (UC), there is considerable controversy regarding adverse effects of vedolizumab on surgical outcomes. We evaluated 30-day postoperative morbidity in UC patients undergoing abdominal colectomy (AC) treated with vedolizumab before surgery.

Methods

From 2007 to 2017, 285 patients were enrolled in prospectively maintained database evaluating the role of clinical, serologic markers with clinical phenotypes in UC. The patients treated with vedolizumab within 12 weeks of AC was queried, then matched 1:3:3 into 3 preoperative treatment groups based on age, gender and surgical treatment of UC; ileal pouch-anal anastomosis (IPAA) with ileostomy vs total colectomy with end stoma: a) vedolizumab (n = 25); b) anti-tumor necrosis factor (anti-TNF) (n = 74); and c) no biologics (n = 54). Thirty-day postoperative complications among patient groups were compared.

Results

The 3 patient groups were well-matched in other characteristics including disease duration, disease extent, medication history and preoperative serological data. There were no significant differences in the overall incidence of postoperative complications among patients treated preoperatively with vedolizumab, anti-TNFs, or no biologics (44% vs. 45% vs. 37%; p = 0.67). Although there was no significant difference between patient cohorts in infectious complications (p = 0.20), postoperative ileus (POI) was significantly more common among the vedolizumab group (n = 9; 36%) compared to anti-TNF (n = 12; 16%) or no biologics (n = 5; 9%) (p = 0.01). Multivariable analysis showed that vedolizumab treatment prior to surgery was an independent risk factor for POI (OR: 5.16, 95% CI; 1.71–15.52; p = .004).

Conclusion

Although preoperative vedolizumab exposure did not influence the rate of overall 30-day postoperative complications, vedolizumab tends to increase incidence of POI.

Anti-TNF and Postoperative Complications in Abdominal Crohn's Disease Surgery

Background: :

Biological therapy with anti-Tumour Necrosis Factor (TNF)-α agents revolutionised the treatment of inflammatory bowel disease over the last decades. However, there may be an increased risk of postoperative complications in Crohn’s disease (CD) patients treated with anti-TNF-α agents prior to abdominal surgery.

Objective::

To evaluate the effects of preoperative anti-TNF-α therapy on the incidence of complications after surgery.

Methods: :

A critical assessment of the results of clinical trial outcomes and meta-analyses on the available data was conducted.

Results: :

Based on the outcomes of previous reports including meta-analyses, preoperative use of anti- TNF-α agents modestly increased the risk of overall complications and particularly infectious complications after abdominal surgery for CD. Nevertheless, previous studies have several limitations. The majority of them were retrospective research with heterogeneous outcome measures and single centre trials with relatively small sample size. In retrospective studies, the standard protocol for assessing various types of postoperative complications was not used. The most serious limitation of the previous studies was that multiple confounding factors such as malnutrition, use of corticosteroids, and preoperative sepsis were not taken into consideration.

Conclusion::

Among patients treated with preoperative anti-TNF-α therapy, the risk of overall complications and infectious complications may slightly increase after abdominal surgery for CD. Nevertheless, the previous reports reviewed in this study suffered from limitations. To rigorously evaluate the risk of anti-TNF-α therapy prior to surgery, large prospective studies with standardised criteria for assessing surgical complications and with proper adjustment for confounding variables are warranted.

Surgery in the age of biologics

Since the introduction of the first anti-tumor necrosis factor antibodies in the late 1990s, biologic therapy has revolutionized the medical treatment of patients with inflammatory bowel disease (IBD). Nevertheless, surgery continues to play a significant role in treating IBD patients. Rates of intestinal resection in patients with Crohn's disease or colectomy in ulcerative colitis are reducing but not substantially over the long term. An increasing variety of biologic medications are now available to treat IBD patients in various clinical situations. Consequently, a number of questions persist about how biologic medications affect the need for surgery and overall course in IBD patients. Given the trend for earlier and more frequent use of biologic medications in IBD patients, a working knowledge of the effects of these medications on surgical decision-making and outcomes is essential for the practicing colorectal surgeon and gastroenterologist. This review seeks to summarize the relevant literature surrounding biologic use and IBD surgery with a focus on the effect of biologics on the frequency, type and complications of surgery in this 'age of biologics'.

Surgery in the age of biologics

Since the introduction of the first anti-tumor necrosis factor antibodies in the late 1990s, biologic therapy has revolutionized the medical treatment of patients with inflammatory bowel disease (IBD). Nevertheless, surgery continues to play a significant role in treating IBD patients. Rates of intestinal resection in patients with Crohn's disease or colectomy in ulcerative colitis are reducing but not substantially over the long term. An increasing variety of biologic medications are now available to treat IBD patients in various clinical situations. Consequently, a number of questions persist about how biologic medications affect the need for surgery and overall course in IBD patients. Given the trend for earlier and more frequent use of biologic medications in IBD patients, a working knowledge of the effects of these medications on surgical decision-making and outcomes is essential for the practicing colorectal surgeon and gastroenterologist. This review seeks to summarize the relevant literature surrounding biologic use and IBD surgery with a focus on the effect of biologics on the frequency, type and complications of surgery in this 'age of biologics'.

Preoperative use of anti-tumor necrosis factor therapy in Crohn's disease: promises and pitfalls

Recent advances in medical and surgical therapy were achieved during the last two decades in the management of Crohn's disease (CD). Anti-tumor necrosis factor (anti-TNF) agents are widely used worldwide. However, a significant proportion of patients still need surgical resections. The impact of previous exposure to these agents on the perioperative and postoperative outcomes is still controversial. In this critical review, we aimed to position the strategy of intentional preoperative use of anti-TNF agents in the management of CD. The indications and contraindications for this strategy are detailed, and despite scarce evidence, the possible advantages and disadvantages of the intentional use of anti-TNF agents before abdominal surgery in CD are discussed.

The Effect of Infliximab on Intestinal Anastomosis Healing in Rats

Intestinal anastomosis healing is a complex physiological process in which many local and systemic factors play a role. One of the significant cytokines in this process is TNF-α. Infliximab is a chimeric monoclonal antibody which binds to TNF-α with high affinity. Although this agent is used in ulcerative colitis and Crohn’s disease, intestinal surgery may be required in these patients. In this study it was aimed to determine whether or not there was any negative effect of preoperative single dose infliximab treatment on intestinal anastomosis healing. Two groups of 10 rats were formed. One of these groups was administered with a single dose of infliximab 8 mg/kg as a 20-minute intravenous infusion from the femoral vein. Four days after the infusion, a full layer incision was made to the colon and anastomosis was applied to all the rats. At 7 days after anastomosis, the subjects were sacrificed. The anastomosis segment was removed and the bursting pressure was measured. Tissue samples were taken from this segment for hydroxyproline concentration and histopathological examination. A blood sample was taken to measure TNF-α values. No statistically significant difference was determined between the groups in terms of bursting pressure, tissue hydroxyproline concentration or histopathological scoring. A single dose of 8 mg/kg infliximab administered 4 days preoperatively was not found to have any negative effect on intestinal anastomosis healing in rats.

GM6001 Increases Anastomotic Leakage following Colonic Obstruction Possibly by Impeding Epithelialization

BACKGROUND

Emergency operations performed on an obstructed colon are accompanied by an increased risk of anastomotic insufficiency. Tissue-destructive matrix metalloproteinase (MMP) activity is elevated in the obstructed colon and contributes to a loss of suture-holding submucosal collagen, which may be mediated by tumor necrosis factor (TNF)-α. Our aim was to study the effect of the non-selective MMP and TNF-α converting enzyme (TACE) inhibitor GM6001 (30 mg/kg) on anastomosis repair in obstructed left colon. GM6001 has been proved to be highly efficacious in elective anastomosis rodent models.

METHODS

A partial obstruction of the distal colon was induced in male Sprague-Dawley rats. After 4 d the obstructed colonic segment was resected, and an end-to-end anastomosis was constructed. Seven days later, the anastomoses were evaluated for clinical leakage. Histopathological and immunohistochemical assessments were also performed. Finally, the direct effect of GM6001 on epithelialization was studied in cultured colonic epithelial cells.

RESULTS

Unlike the robust beneficial effect on anastomosis under uncomplicated conditions, here GM6001 had a negative impact on anastomotic wound healing following colonic obstruction and substantially (p=0.004) more rats in the GM6001 group (75%) than in the control group (11%) had developed anastomotic leakage. In the anastomotic wounds, the myofibroblast abundance and cell proliferation were similar in the two groups. Histologically, GM6001 treatment resulted in wider and minimally epithelialized wounds that were commonly necrotic on the luminal side and infiltrated with numerous granulocytes. In vitro, GM6001 also delayed (p=0.026) epithelialization of denuded intestinal epithelium grown on type I collagen.

CONCLUSIONS

Non-selective MMP/TACE inhibition with GM6001 increased the anastomotic complications following colon obstruction. Inhibition of epithelialization is one possible mechanism responsible for the increased leakage following GM6001 treatment.

The effect of gabapentin and pregabalin on intestinal incision wound healing in rabbits

AIM

To evaluate the macroscopic and histologic effects of pregabalin (PG) gabapentin (GB) on longitudinal intestinal wound healing in New Zealand rabbits.

MATERIALS AND METHODS

The animals were divided into three groups randomly; the control group (n=6), PG group (n=6) and GB group (n=6). All animals were premedicated with xylazine HCI, 5 mg/kg i.m. and general anaesthesia was performed by ketamine HCI 50 mg/kg i.m injection. A 4 cm incision in the caecum through median laparotomy was achieved under aseptic surgery. Intestinal wound was closed with double-sutured. All animals were received parenteral antibiotic treatment for 5 days. PG and GB groups were treated by PG (30 mg/kg, oral, daily) and GB (30 mg/kg, oral, daily) for 10 days respectively. Control group did not receive any treatment. The animals were euthanized on day 10 and the caecum was examined by laparotomy. Adhesion formation was observed, and tissue samples were taken from suture lines for histologic examination. Cellular infiltration (polymorphonuclear white blood cells and mononuclear cells), accumulation of connective tissue, vascularization and extent of necrosis were evaluated and scored separately for each of mucosal, submucosal, muscular and serosal layers of caecum.

RESULTS

Adhesions were more severe in the GB group compared to other groups. No statistically significant differences were detected among the three groups about the wound healing.

CONCLUSION

It was suggested that the use of gabapentinoids had no significant effect on wound healing in patients undergoing gastrointestinal surgery and further studies with treatment periods longer than 10 days are needed.