Influence of adalimumab treatment on anastomotic strength, degree of inflammation, and collagen formation: an experimental study on the small intestine of rabbits

Ileocolonic Healing After Extended Small Bowel Resection in Mice: NOD2 Deficiency Impairs Anastomotic Healing and Postoperative Outcome

BACKGROUND

Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) mutations are a genetic risk factor for Crohn disease. Ileocecal resection is the most often performed surgery in Crohn disease. We investigated the effect of Nod2 knockout (KO) status on anastomotic healing after extended ileocecal resection (ICR) in mice.

METHODS

Male C57BL6/J wild-type and Nod2 KO mice underwent an 11 cm resection of the terminal ileum including the cecum. An end-to-end jejuno-colostomy was performed. Animals were killed after 5 days investigating bursting pressure, hydroxyproline content, and expression of matrix metabolism genes, key cytokines, and histology of the anastomosis.

RESULTS

Mortality was higher in the Nod2 KO group but not because of local or septic complications. Bursting pressure was significantly reduced in the Nod2 KO mice (32.5 vs 78.0 mmHg, P < 0.0024), whereas hydroxyprolin content was equal. The amount of granulation tissue at the anastomosis was similar but more unstructured in the Nod2 KO mice. Gene expression measured by real-time polymerase chain reaction showed significantly increased expression for Collagen 1alpha and for collagen degradation as measured by matrix metalloproteinase-2, -9, and -13 in the Nod2 KO mice. Gelatinase activity from anastomotic tissue was enhanced by Nod2 status. Gene expression of arginase I, tumor necrosis factor-α, and transforming growth factor-ß but not inducible nitric oxide synthase were also increased at the anastomosis in the Nod2 KO mice compared with the control mice.

CONCLUSIONS

We found that Nod2 deficiency results in significantly reduced bursting pressure after ileocecal resection. This effect is mediated via an increased matrix turnover. Patients with genetic NOD2 variations may be prone to anastomotic failure after bowel resection.

Biological Treatment and the Potential Risk of Adverse Postoperative Outcome in Patients With Inflammatory Bowel Disease: An Open-Source Expert Panel Review of the Current Literature and Future Perspectives

Background

There is widespread concern that treatment with biologic agents may be associated with suboptimal postoperative outcome after surgery for inflammatory bowel diseases (IBD).

Aim

We aimed to search and analyze the literature regarding the potential association of biologic treatment on adverse postoperative outcome in patients with IBD. We used the subject as a case in point for surgical research. The aim was not to conduct a new systematic review.

Method

This is an updated narrative review written in a collaborative method by authors invited through Twitter via the following hashtags (#OpenSourceResearch and #SoMe4Surgery). The manuscript was presented as slides on Twitter to allow discussion of each section of the paper sequentially. A Google document was created, which was shared across social media, and comments and edits were verified by the primary author to ensure accuracy and consistency.

Results

Forty-one collaborators responded to the invitation, and a total of 106 studies were identified that investigated the potential association of preoperative biological treatment on postoperative outcome in patients with IBD. Most of these studies were retrospective observational cohorts: 3 were prospective, 4 experimental, and 3 population-based studies. These studies were previously analyzed in 10 systematic/narrative reviews and 14 meta-analyses. Type of biologic agents, dose, drug concentration, antidrug antibodies, interval between last dose, and types of surgery varied widely among the studies. Adjustment for confounders and bias control ranged from good to very poor. Only 10 studies reported postoperative outcome according to Clavien–Dindo classification.

Conclusion

Although a large number of studies investigated the potential effect of biological treatment on postoperative outcomes, many reported divergent results. There is a need for randomized controlled trials. Future studies should focus on the avoiding the weakness of prior studies we identified. Seeking collaborators and sharing information via Twitter was integral to widening the contributors/authors and peer review for this article and was an effective method of collaboration.

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'.

No effect of anti-TNF-α agents on the surgical stress response in patients with inflammatory bowel disease undergoing bowel resections: a prospective multi-center pilot study

BACKGROUND

TNF-α plays a role in angiogenesis and collagen synthesis, both essential in the wound healing process. There are concerns that pre-operative anti-TNF-α treatment may influence the surgical stress response and increase the risk of surgical complications. The aim of this study was to describe the surgical stress response in patients with inflammatory bowel disease (IBD) and to investigate whether the pre-operative administration of anti-tumor necrosis factor alpha (anti-TNF-α) agents modify the surgical stress response.

METHODS

This was a prospective, multi-center cohort pilot study. The primary outcome was the change in concentration of immunological biomarkers of the surgical stress response (TNF-α, IL-6, and IL-10). Secondary outcome measures were changes in IL-8, IL-17A, C-reactive protein, white blood cells, cortisol, transferrin, ferritin, and D-Dimer in addition to 30 days' post-operative complications and length of post-operative stay in the hospital (LOS).

RESULTS

Forty-six patients with IBD undergoing major abdominal surgery were included, and 18 received anti-TNF- α treatment pre-operatively. Peak increase of most of the immunological biomarkers occurred 6 hours after surgical incision. Then the concentration decreased after 24 h followed by a plateau at 48 h. After adjusting for confounders including detectable blood concentrations, no difference in the concentrations of immunological, endocrinological or haematological biomarkers of stress was found between anti-TNF-α treated and anti-TNF-α naïve patients. No increase in post-operative complications or LOS was noticed in patients who received anti-TNF-α treatment.

CONCLUSIONS

Anti-TNF-α did not affect surgical stress response in this pilot study. Withdrawal of anti-TNF-α drugs prior to surgical intervention in IBD patients might not be justified without measurement of drug concentration and drug antibodies.

TRIAL REGISTRATION

Clinicaltrails.gov.: NCT01974869 .

Evaluating the effect of infliximab on the healing of left colonic anastomosis in the presence of intra-abdominal sepsis

BACKGROUND AND STUDY AIMS

Infliximab (IFX) is a chimeric anti-TNF-α body which is effectively used in the treatment of inflammatory bowel diseases and a variety of autoimmune diseases. The effect of IFX on the healing of intestinal anastomosis has been evaluated in several studies, however with conflicting results. Furthermore, the effect of IFX on colonic anastomosis in sepsis has not been evaluated to date. In this study, we aimed to investigate whether IFX has an adverse effect on the healing process of colonic anastomosis either under normal or septic condition.

MATERIAL AND METHOD

The efficiency of IFX was assessed with respect to anastomotic bursting pressure (ABP), tissue hydroxyproline levels (THL) and histopathological examination of left colonic anastomosis in 40 male rats. The rats were randomly allocated into four groups of 10 rats each as control (C), septic control (SC), control IFX (C-IFX) and septic IFX (S-IFX).

RESULTS

The anastomotic bursting pressure was measured at 182±19.1, 158±15.4, 161±26.8 and 100±10.3mm/Hg, in C, SC, C-IFX and S-IFX; respectively. IFX administration did not influence the anastomotic strength under normal condition whereas in sepsis significantly induced the reduction of APB. The mean THL was almost similar in both control groups (p=0.87), whilst IFX reduced the level of TH in sepsis comparing with control groups (p=0.01). IFX significantly impaired immune response in sepsis resulting in poor anastomotic healing in S-IFX group.

CONCLUSION

Our study demonstrated that IFX had no detrimental effect on the healing of colonic anastomosis under normal condition whilst significantly impaired the healing process in sepsis.

Effect of Humira® on Intestinal Anastomotic Response in Rabbits

AIM

The aim of this study was to compare the strength and degree of inflammation in small intestinal anastomoses in rabbits after repeated preoperative treatment with the TNF-α antibody, adalimumab (Humira®), compared to placebo.

METHOD

Thirty-three New Zealand white female rabbits were randomized to three weeks of weekly subcutaneous injections of adalimumab (n = 24) or placebo (n = 9). After this treatment regime, two end to end anastomoses were performed in the ileum. Following euthanasia on postoperative day 5 the anastomoses were evaluated for minimal tensile strength (MITS) and histological parameters of wound healing using a modified Verhofstad Scale.

RESULTS

There were no statistically significant differences between the adalimumab and placebo groups in terms of MITS or histological parameters. Multiple regression analyzes revealed that there was no association between MITS and treatment, numbers of sutures, length of surgery, preoperative weight gain, postoperative weight loss or histological score. On the day of surgery the median serum concentration of adalimumab was 5.4 μg/ml (3.4-8.6).

CONCLUSION

Repeated preoperative treatment with adalimumab had no significant influence on MITS or histological score in anastomoses in the small intestine of the rabbits.

Infliximab treatment reduces tensile strength in intestinal anastomosis

BACKGROUND

The antitumor necrosis factor (infliximab [IFX]) has gained widespread use in the treatment of inflammatory bowel disease. However, several patients must undergo surgical treatment due to treatment failure and there is a potential risk that preoperative IFX treatment may have a negative effect on the healing process in intestinal anastomosis. The objective of this study was to examine the effect of repeated IFX treatment on anastomotic strength and degree of inflammation in the anastomotic line in the small intestine of rabbits.

METHODS

Thirty-two rabbits were randomized (2:1) to receive either repeated IFX treatment or placebo. On day 15, three separate end-to-end anastomoses were performed on the jejunum. On postoperative day 5, tensile strength and bursting pressure for the anastomoses were tested and histologic changes examined.

RESULTS

We found a significantly reduced tensile strength in the IFX group (1.94 ± 0.44 N) compared with the placebo group (3.33 ± 0.39 N), (P < 0.001). Calculation of Spearman correlation coefficients showed a positive significant correlation between minimal tensile strength and serum values of IFX (coefficient = -0.63; P = 0.003) as well as number of sutures in the tested anastomosis (coefficient = 0.51; P = 0.024). The general histologic score was significantly higher in the placebo group (5.00 ± 1.26 versus 3.31 ± 1.65, P = 0.03).

CONCLUSIONS

Repeated high-dose IFX treatment reduces tensile strength significantly in rabbits and should be investigated further as a potential risk factor of anastomotic dehiscence in inflammatory bowel disease surgery.

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

BACKGROUND

Infliximab, a TNF-α inhibitor, is a potent anti-inflammatory drug in the treatment of inflammatory bowel diseases. Recent studies have investigated the effect of infliximab treatment on postoperative complications such as anastomotic leakage, however, with conflicting results and conclusions. The purpose of this study was to investigate whether a single dose infliximab has an adverse effect on the anastomotic healing process, observed as reduced anastomotic breaking strength and histopathologically verified lower grade of inflammatory response, in the small intestine of a rabbit.

METHODS

Thirty New Zealand rabbits (median weight 2.5 kg) were allocated to treatment with an intravenous bolus of either 10 mg/kg infliximab (n = 15) or placebo (n = 15). One week later all rabbits underwent two separate end-to-end anastomoses in the jejunum under general anesthesia. At postoperative day three, the anastomotic breaking strength was determined and histopathological changes were examined.

RESULTS

The mean value of anastomotic breaking strength in the placebo group was 1.89 ± 0.36 N and the corresponding value was 1.81 ± 0.33 N in the infliximab treated rabbits. There was no statistically significant difference between the groups (p = 0.51). The infliximab-treated rabbits had a significant lower degree of inflammatory infiltration response compared to the placebo group (p = 0.047).

CONCLUSIONS

Our conclusion, limited by the small sample sizes in both groups, is that a single dose of infliximab, given one week prior to surgery, does not have an impact on the anastomotic breaking strength on the third postoperative day in the small intestine of rabbits.