The influence of NSAIDs on experimental intestinal anastomoses

Risk of NSAID-associated anastomosis leakage after colorectal surgery: a large-scale retrospective study using propensity score matching

PURPOSE

NSAIDs are commonly used as opioid-sparing analgesics in colorectal surgery. Many efforts are made to elucidate the risk of NSAID-associated anastomotic leakage after colorectal surgery. However, these results still remain controversial. In this study, we applied large-scale retrospective analysis using propensity score matching to fully clarify the association between risk of anastomotic leakage and use of NSAID after colorectal surgery.

METHODS

All colorectal cancer patients receiving operation during February 2008 to August 2018 in our multi-institution medical organization research database were enrolled. It is worthy to mention that only patients requiring re-operation within 21 days after colorectal surgery due to anastomotic leakage were counted as anastomosis leakage. Furthermore, a propensity score TriMatch analysis was performed to prevent from interference of confounding factors.

RESULTS

A total of 10,584 patients were included in this study and divided into three groups, no NSAIDs group, non-selective NSAIDs group, and selective COX-2 inhibitors group, respectively. Before tri-matching analysis, significant differences in anastomotic leakage rate were observed. After propensity score matching analysis, the ratio of anastomotic leakage requiring re-operation occurred in 2.0%, 3.6%, and 2.0% in no NSAIDs, non-selective NSAIDs, and selective COX-2 inhibitors group, respectively. No significant difference was observed in these three groups.

CONCLUSION

These results suggest that NSAIDs are not associated with incidence of anastomosis leakage following colorectal surgery. To our knowledge, it is the first study demonstrating that NSAIDs is not associated with incidence of anastomosis leakage following colorectal surgery using propensity score matching at a larger-scale retrospective study.

The effects of steroidal and non-steroidal anti-inflammatory drugs on tracheal wound healing in an experimental rat model

OBJECTIVES

The effect of non-steroidal anti-inflammatory drugs (NSAID), mostly used for postoperative analgesic purposes for wound healing, is still a matter of debate. Our goal was to evaluate the effects of the most widely used NSAID and corticosteroids after surgical operations on tracheal wound healing in an experimental rat model.

METHODS

Thirty-nine male Wistar albino rats were included in this study. Tracheotomy was performed in 32 rats; then they were divided into 3 groups. After the first day, the animals in group 1 were treated with an NSAID (diclofenac 10 mg/kg/day) (NSAID, n = 12) for 7 days; the animals in group 2 were treated with a corticosteroid (dexamethasone, 2 × 0.1 mg/kg/day) (steroid, n = 10) for 7 days; the animals in group 3 (control, n = 10) were not given any medications. For a fourth group (histological control, n = 7), in order to evaluate normal morphological and histological characteristics, neither surgery nor medication was used. Five rats were eliminated from the study (2 rats in the NSAID group died and 3 rats in the steroid group developed local wound infections). The drop-out rate was 12.8%. Histological characteristics, inflammation, fibrosis, necrosis, neochondrogenesis, neovascularization and epithelization were evaluated in 34 rats. Non-parametric tests were used for statistical analysis.

RESULTS

Inflammation, vascularization and number of fibroblasts and chondrocytes were significantly higher in the control group than in the histological control group. There was some reduction in all parameters except vascularization in the NSAID group (P > 0.05). When the steroid group was compared to the NSAID group, inflammation (P < 0.05), vascularization and number of chondrocytes (P > 0.05) were more suppressed in the steroid group. The number of fibroblasts increased in the steroid group (P > 0.05).

CONCLUSIONS

Steroids and NSAID may have negative effects on tracheal wound healing, probably by suppressing inflammation and fibroblast proliferation. NSAID was mostly used postoperatively for analgesic purposes and should be avoided.

Anastomotic healing in a rat model of peritonitis after non-steroidal anti-inflammatory drug administration

The tissue inflammatory response can influence the outcome of anastomotic healing. Anastomotic leakage represents a dreadful complication after gastrointestinal surgery, in particular sepsis and intra-abdominal infections impair the restorative process of colic anastomoses. It has been debated whether the administration of nonsteroidal anti-inflammatory drugs (NSAIDs) is a risk factor for dehiscence, since many patients receive NSAIDs in the early postoperative period. Our aim was, for the first time, to analyze the morpho-functional effects of postoperative administration of two commonly used NSAIDs, Diclofenac and Ketorolac, on the healing process of colo-colic anastomoses constructed under condition of fecal peritonitis in a rat model. Sixty adult male rats underwent two surgical procedures: peritonitis induction and colo-colic anastomosis, and were divided into three groups: 20 rats received saline; 20 rats 4 mg/kg Diclofenac and 20 rats 5 mg/kg Ketorolac. We assessed anastomosis strength, morphological features of tissue wound healing, immunohistochemical metalloproteinase 9 (MMP9) expression and collagen deposition and content by Sirius red staining and hydroxyproline level. We found no significant difference in bursting pressure, collagen content and organization and morphological features between the groups, except a significantly reduced presence of inflammatory cells and MMP9 expression in the groups treated with NSAIDs. Our findings showed that Diclofenac and Ketorolac administration did not affect post-surgical healing and did not increase the leakage risk of colo-colic anastomoses during peritonitis.

Postoperative non-steroidal anti-inflammatory drugs and anastomotic leakage after gastrointestinal anastomoses: Systematic review and meta-analysis

AIM

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to control postoperative pain; however, their postoperative use has been associated with anastomotic leakage after gastrointestinal surgery. This systematic review and meta-analysis aimed to determine the correlation between the use of NSAIDs and anastomotic leakage.

METHODS

We conducted a comprehensive electronic literature search up to August 2018 to identify studies comparing anastomotic leakage in patients with and without postoperative NSAID use following gastrointestinal surgery. We then carried out a meta-analysis using random-effects models to calculate odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Twenty-four studies were included in this meta-analysis, including a total of 31 877 patients. Meta-analysis showed a significant association between NSAID use and anastomotic leakage (OR 1.73; 95% CI = 1.31-2.29, P < .0001). Subgroup analyses showed that non-selective NSAIDs, but not selective cyclooxygenase-2 inhibitors, were significantly associated with anastomotic leakage. However there was no significant subgroup difference between selective and non-selective NSAIDs.

CONCLUSION

Results of this meta-analysis indicate that postoperative NSAID use is associated with anastomotic leakage following gastrointestinal surgeries. Caution is warranted when using NSAIDs for postoperative analgesic control in patients with gastrointestinal anastomoses.

Scar management in burn injuries using drug delivery and molecular signaling: Current treatments and future directions

In recent decades, there have been tremendous improvements in burn care that have allowed patients to survive severe burn injuries that were once fatal. However, a major limitation of burn care currently is the development of hypertrophic scars in approximately 70% of patients. This significantly decreases the quality of life for patients due to the physical and psychosocial symptoms associated with scarring. Current approaches to manage scarring include surgical techniques and non-surgical methods such as laser therapy, steroid injections, and compression therapy. These treatments are limited in their effectiveness and regularly fail to manage symptoms. As a result, the development of novel treatments that aim to improve outcomes and quality of life is imperative. Drug delivery that targets the molecular cascades of wound healing to attenuate or prevent hypertrophic scarring is a promising approach that has therapeutic potential. In this review, we discuss current treatments for scar management after burn injury, and how drug delivery targeting molecular signaling can lead to new therapeutic strategies.

Effect of Postoperative Diclofenac on Anastomotic Strength and Histologic Healing in Rabbit Small Intestine

In this experimental study, we investigated the effects of a 5-day postoperative treatment with the nonsteroidal anti-inflammatory drug (NSAID) diclofenac on anastomotic healing in rabbits. NSAIDs are widely used analgesics in today's “fast-track surgery,” raising concerns about their potential negative effects on healing in humans. A total of 33 New Zealand White female rabbits underwent laparotomy and 2 separate end-to-end anastomoses of the ileum.. The animals were randomized to receive subcutaneous diclofenac 4 mg/kg/d (17 experimental rabbits) or subcutaneous isotonic saline 0.1 mL/kg/d (16 control rabbits) postoperatively. On the fifth postoperative day, the animals were humanely killed, and anastomotic leakage, anastomotic breaking strength, and histopathologic changes were evaluated. Breaking strength in the diclofenac group was 21% lower than in the placebo group (P = 0.027). Anastomotic leakage was found in 4 rabbits in the diclofenac group (26.7%). The rabbits treated with diclofenac demonstrated a 16% lower collagen deposition compared with the placebo group (P = 0.008). In our study, postoperative treatment with diclofenac had a negative effect on the anastomotic healing and strength in the ileum of rabbits. Caution should be taken in the use of diclofenac after gastrointestinal surgery.

Postoperative nonsteroidal anti-inflammatory drugs and risk of anastomotic leak: meta-analysis of clinical and experimental studies

BACKGROUND

Enhanced recovery programs following colorectal resection recommend the use of nonsteroidal anti-inflammatory drugs (NSAIDs) as part of multimodal analgesia. The present study aimed to assess whether postoperative NSAID use increased the risk of anastomotic leak.

METHODS

A systematic review of published literature was performed for studies comparing anastomotic leak following NSAID administration versus control. Meta-analysis was conducted for studies in human patients and experimental animal models. The primary endpoint was anastomotic leak.

RESULTS

The final analysis included 8 studies in humans and 12 experimental animal studies. Use of NSAIDs was significantly associated with anastomotic leak in humans (8 studies, 4,464 patients, odds ratio [OR] 2.14; p < 0.001). This effect was seen with nonselective NSAIDs (6 studies, 3,074 patients, OR 2.37; p < 0.001), but not with selective NSAIDs (4 studies, 1,223 patients, OR 2.32; p = 0.170). There was strong evidence of selection bias from all clinical studies, with additional inconsistent definitions and outcomes assessment. From experimental animal models, anastomotic leak was more likely with NSAID use (ten studies, 575 animals, OR 9.51; p < 0.001). Bursting pressures at day 7 were significantly lower in NSAID versus controls (7 studies, 168 animals, weighted mean difference -35.7 mmHg; p < 0.001).

CONCLUSIONS

Emerging data strongly suggest that postoperative NSAIDs are linked to anastomotic leak, although most studies are flawed and may be describing pre-existing selection bias. However, when combined with experimental data, these increasing concerns suggest caution is needed when prescribing NSAIDs to patients with pre-existing risk factors for leak, until more definitive evidence emerges.

Diclofenac causes more leakage than naproxen in anastomoses in the small intestine of the rat

BACKGROUND

Non-steroid anti-inflammatory drugs such as the cyclooxygenase isoenzyme inhibitors diclofenac and naproxen are increasingly used for perioperative pain relief, while their potential effects on wound healing are scarcely investigated.

METHODS

In 104 male Wistar rats, an anastomosis was constructed in both colon and ileum. The rats were divided into groups who received diclofenac (4 mg kg(-1) day(-1)) or naproxen (10 mg kg(-1) day(-1)) daily from the day of surgery or from day 3 after surgery. Animals were killed on day 3 or 7 and analysed for signs of anastomotic dehiscence and wound strength of anastomoses and abdominal fascia.

RESULTS

Anastomotic leakage in the ileum (p < 0.0001) and mortality rates (p = 0.001) were significantly increased in the diclofenac group. On day 7, the anastomotic bursting pressure in the ileum remained below that of the controls in the diclofenac- and naproxen-treated rats. When administration of diclofenac was postponed to day 3 after surgery, anastomotic dehiscence was almost absent. The colonic anastomosis and abdominal wall always remained unaffected.

CONCLUSIONS

This study implies that immediate postoperative administration of diclofenac and, to a far lesser extent, naproxen can affect healing in the ileal anastomosis in the rat. This negative effect can be prevented by a short postoperative delay in administration. On steroid anti-inflammatory drugs such as the cyclooxygenase isoenzyme inhibitors diclofenac and naproxen are increasingly used for perioperative pain relief, while their potential effects on wound healing are scarcely investigated.

Increased risk for complications after colorectal surgery with selective cyclo-oxygenase 2 inhibitor etoricoxib

BACKGROUND

Cyclo-oxygenase 2 inhibitors can be used for pain treatment after colorectal surgery.

OBJECTIVE

The aim of this study was to investigate whether the use of etoricoxib has negative effects on the perioperative outcome in colorectal surgery.

DESIGN

Complication data from an advanced medical database system were sampled prospectively, and patient records were reviewed retrospectively.

PATIENTS

All patients with elective colorectal surgery within an enhanced recovery after surgery protocol from 2008 to 2009 were selected.

INTERVENTION

The nonrandomized use of perioperative etoricoxib treatment was compared with a control group.

MAIN OUTCOME MEASURES

The primary outcome measured was the number of patients with postoperative complications according to the Dindo-Clavien classification.

RESULTS

One hundred one patients received etoricoxib treatment, whereas 104 did not. The patient groups were very comparable. We observed a significant increase in the number of patients with postoperative complications with etoricoxib treatment (43 vs 30 patients; 42.6% vs 28.8%, p = 0.041) due to an increase in patients with a major complication (Dindo-Clavien complication grade III-V: 22.8% vs 9.6%, p = 0.01). Patients with etoricoxib treatment and a complication needed a longer recovery period than patients with a complication in the control group (18 (17; 20) vs 14 (13; 15) days, p = 0.05). We observed an increased level of postoperative serum creatinine with etoricoxib treatment (105 (98; 112) vs 82 (78; 85), p = 0.003), which was more pronounced in patients with a complication (141 (127; 155) vs 91 (83; 98), p = 0.002; 25 vs 8 patients with serum creatinine >100 μmol/L, p = 0.008). In multivariate analysis, etoricoxib was identified as an independent risk factor for experiencing a major complication with a risk increase of approximately 2.5-fold (p = 0.03).

LIMITATIONS

This study was limited by the nonrandomized use of perioperative etoricoxib and the retrospective nature of its review of patient records.

CONCLUSIONS

Etoricoxib increased the number of patients with postoperative complications and should be considered carefully in colorectal surgery.

Nonsteroidal anti-inflammatory drugs and anastomotic dehiscence in bowel surgery: systematic review and meta-analysis of randomized, controlled trials

BACKGROUND

Nonsteroidal anti-inflammatory drugs are a key component of contemporary perioperative analgesia. Recent experimental and observational clinical data suggest an associated increased incidence of anastomotic dehiscence in bowel surgery.

OBJECTIVE

The aim of this study was to conduct a systematic review and meta-analysis of anastomotic dehiscence in randomized, controlled trials of perioperative nonsteroidal anti-inflammatory drugs.

DATA SOURCES

Published and unpublished trials in any language reported 1990 or later were identified by searching electronic databases, bibliographies, and relevant conference proceedings.

STUDY SELECTION

Trials of adults undergoing bowel surgery randomly assigned to perioperative nonsteroidal anti-inflammatory drugs or control were included. The number of patients with a bowel anastomosis and the incidence of anastomotic dehiscence had to be reported or be available from authors for the study to be included.

INTERVENTION

At least 1 dose of a nonsteroidal anti-inflammatory drug was given perioperatively within 48 hours of surgery.

MAIN OUTCOME MEASURES

The primary outcome measured was 30-day incidence of anastomotic dehiscence as defined by authors.

RESULTS

Six trials comprising 480 patients having a bowel anastomosis met inclusion criteria. In 4 studies, anastomotic dehiscence rates were higher in the intervention groups. Overall rates were 14/272 participants (5.1%) in intervention arms vs 5/208 (2.4%) in control arms. Peto OR was 2.16 (95% CI 0.85, 5.53; p = 0.11), and there was no heterogeneity between studies (I statistic 0%).

LIMITATIONS

Sizes of available trials were small, preventing firm conclusions and subset analysis of drugs of different cyclooxygenase specificity. A precise and consistent definition of anastomotic dehiscence was not used across trials.

CONCLUSIONS

A statistically significant difference in incidence of anastomotic dehiscence was not demonstrated. However, the Peto OR of 2.16 (0.85, 5.53) and lack of heterogeneity between trials suggest that this finding may be due to a lack of power of the available data rather than a lack of effect.

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. In experiment 1 eighty-four rats were divided over control and experimental groups, which received daily buprenorphine or carprofen, respectively, as an analgesic and were killed on day 1, 2 or 3 after surgery. In experiment 2 three groups of 15 rats received carprofen either immediately after surgery or with a delay of 1 or 2 days. Animals were killed after 3 days of carprofen administration. In experiment 3 three groups of 10 rats received different doses (full, half or quarter) of carprofen from surgery.

In significant contrast to buprenorphine, which never did so, carprofen induced frequent signs of anastomotic leakage, which were already present at day 1. If first administration was delayed for 48 hours, the leakage rate was significantly reduced (from 80 to 20%; p = 0.0028). Throughout the study, the anastomotic bursting pressure was lowest in animals who displayed signs of anastomotic leakage. Loss of anastomotic integrity did not coincide with reduced levels of hydroxyproline or increased activity of matrix metalloproteinases.

Conclusions

Carprofen interferes with wound healing in the rat ileum at a very early stage. Although the mechanisms responsible remain to be fully elucidated, one should be aware of the potential of NSAIDs to interfere with the early phase of wound repair.

Perioperative pain relief by a COX-2 inhibitor affects ileal repair and provides a model for anastomotic leakage in the intestine

The authors examined the potential of the cyclooxygenase 2 (COX-2) inhibitor carprofen to reproducibly induce anastomotic leakage. In experiment 1, an anastomosis was constructed in both ileum and colon of 20 rats, and they were given carprofen (5 mg/kg subcutaneously every 24 hours) or buprenorphine (0.02 mg/kg subcutaneously every 12 hours). In another 20 rats an anastomosis was constructed in either ileum or colon, and all received carprofen (experiment 2). Animals were sacrificed after 3 days. In experiment 1, the ileal dehiscence rate was 60% in the carprofen group and 0% in the buprenorphine group (P = .0108). Colonic anastomoses in both groups remained patent. In experiment 2, the anastomotic leakage rate was 80% in ileum and 0% in colon. Thus, COX-2 inhibitors can severely interfere with intestinal healing, particularly in the ileum. Perioperative administration of carprofen yields a unique model for anastomotic leakage, which allows translational research on the effectiveness of perisuture line reinforcement.

Effect of postoperative diclofenac on anastomotic healing, skin wounds and subcutaneous collagen accumulation: a randomized, blinded, placebo-controlled, experimental study

BACKGROUND

Retrospective studies have drawn attention to possible detrimental effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the anastomotic leakage rate after colorectal resection. In this study, we examined the effects of the NSAID diclofenac on the breaking strength of an experimental colonic anastomosis and a skin incision as well as subcutaneous collagen accumulation.

METHODS

This was a randomized, blinded, placebo-controlled experimental study in 60 male Wistar rats treated with diclofenac 4 mg/kg/day or placebo. In each rat, a colonic anastomosis was performed and an expanded polytetrafluoroethylene (ePTFE) tube was placed subcutaneously. Incisional and anastomotic wound breaking strength and hydroxyproline content in the ePTFE tubes were measured 7 days after the operation.

RESULTS

We found no significant differences in any of the breaking strength measurements, but showed a median 38% reduction in hydroxyproline deposition as a result of diclofenac treatment (p = 0.03). In the placebo group, subcutaneous collagen deposition tended to correlate positively with skin incisional but negatively with anastomotic bio-mechanical strength.

CONCLUSION

Postoperative diclofenac treatment significantly inhibited collagen deposition in subcutaneous granulation tissue. Anastomotic strength and skin wound strength were not significantly affected. The ePTFE model is suitable for assessing the effect of various drugs on collagen formation and thus on wound healing.

Risk of anastomotic leakage with use of NSAIDs after gastrointestinal surgery

PURPOSE

Analgesic regimes to avoid opioid-related adverse effects have been recommended in gastrointestinal surgery. Non-steroidal anti-inflammatory drugs (NSAIDs) are an important component of opioid sparing regimes in that these drugs indirectly reduce pain by inhibiting inflammation. Although beneficial for most surgical patients, animal studies and recent clinical studies suggest a harmful effect on new intestinal anastomoses by increasing the rate of leakage. NSAIDs may indirectly disturb anastomotic healing by inhibiting inflammation as an integrated part of the wound healing process in an early, critical phase after surgery.

METHODS

A literature review based on a structured search in PubMed of clinical and experimental studies investigating the effects of NSAIDs on anastomotic healing and leakage rates after intestinal surgery, as well as proposed mechanisms and effects studied in animal models.

RESULTS

Three recent observational cohort studies (accumulated n = 882) indicate an increased rate of anastomotic leakages (15-21%) associated with cyclooxygenase-2 (COX-2) selective NSAIDs after intestinal surgery compared to the leakage rates in controls or historical cohorts (1-4%). Three prospective studies on related topics contain relevant data on NSAIDs and are compared to these studies. Several experimental animal studies support an increased risk for anastomotic leakage with the use of NSAIDs.

CONCLUSION

The reported effects of NSAIDs on anastomotic healing suggest an increased risk for leakage. A better understanding of the complex interactions of NSAID-induced inhibition on anastomotic healing is a prerequisite for the safe use of NSAIDs. Until more data are available, a careful use of NSAIDs may be warranted in gastrointestinal anastomotic surgery.

The effect of glucagon-like Peptide-2 receptor agonists on colonic anastomotic wound healing

Background. Glucagon-like peptide 2 (GLP-2) is an intestinal specific trophic hormone, with therapeutic potential; the effects on intestinal healing are unknown. We used a rat model of colonic healing, under normoxic, and stress (hypoxic) conditions to examine the effect of GLP-2 on intestinal healing. Methods. Following colonic transection and reanastomosis, animals were randomized to one of six groups (n = 8/group): controls, native GLP-2, long-acting GLP-2 (GLP-2- MIMETIBODY, GLP-2-MMB), animals were housed under normoxic or hypoxic (11%  O₂) conditions. Animals were studied five days post-operation for anastomotic strength and wound characteristics. Results. Anastomotic bursting pressure was unchanged by GLP-2 or GLP-2-MMB in normoxic or hypoxic animals; both treatments increased crypt cell proliferation. Wound IL-1β increased with GLP-2; IFNγ with GLP-2 and GLP-2-MMB. IL-10 and TGF-β were decreased; Type I collagen mRNA expression increased in hypoxic animals while Type III collagen was reduced with both GLP-2 agonists. GLP-2 MMB, but not native GLP-2 increased TIMP 1-3 mRNA levels in hypoxia. Conclusions. The effects on CCP, cytokines and wound healing were similar for both GLP-2 agonists under normoxic and hypoxic conditions; anastomotic strength was not affected. This suggests that GLP-2 (or agonists) could be safely used peri-operatively; direct studies will be required.

Cyclo-oxygenase 2 inhibitors and the risk of anastomotic leakage after fast-track colonic surgery

BACKGROUND

Anastomotic leakage occurs after 3-6 per cent of colonic resections. The influence of analgesic agents is largely unknown. This study determined the rate of anastomotic leakage in a series of patients who had colonic surgery over a 9-year period with or without use of a cyclo-oxygenase inhibitor for postoperative analgesia.

METHODS

Patients with anastomotic leakage following a standard fast-track procotol between April 1997 and May 2006 were identified from a prospective, consecutive database. During this period there were two changes in perioperative management: cessation of preoperative oral bowel preparation in August 2002 and the use of celecoxib for postoperative analgesia between May 2003 and November 2004. Rates of anastomotic leakage during the various periods were determined and compared.

RESULTS

Some 28 (5.6 per cent) of 502 patients had an anastomotic leak. The incidence of leakage increased significantly during the period of celecoxib use (15.1 per cent), versus 3.3 and 1.5 per cent respectively before and after celecoxib use (P < 0.001). Leakage rates were similar with or without oral bowel preparation (3.5 versus 1.7 per cent respectively; P = 0.346) when celecoxib was not used.

CONCLUSION

A detrimental effect of celecoxib on anastomotic healing is suggested, and requires further evaluation.

Effects of cyclooxygenase inhibition on anastomotic healing following large bowel resection in a rabbit model--a randomized, blinded, placebo-controlled trial

PURPOSE

We performed an experimental study in a rabbit model to investigate the effects of a selective Cox-2 inhibitor (Valdecoxib) on anastomotic healing following large bowel resection after 1 week.

MATERIALS AND METHODS

Eighty New Zealand white rabbits were randomized into four groups and underwent a colon resection with end-to-end anastomosis. Group 1 (n = 20) was treated with Valdecoxib, group 2 with Metamizole (Novalgin), group 3 with Resveratrol (specific Cox-1 inhibitor), or a placebo vehicle with similar volume (group 4). Anastomotic healing was tested at the seventh postoperative day by measurement of the bursting pressure in vitro. Immunohistochemical staining of the anastomotic site was performed with polyclonal antibodies (CD31).

RESULTS

There were no significant differences in anastomotic dehiscence, bursting pressure, or vessel density between the treatment and control groups.

CONCLUSION

The application of Valdecoxib does not influence anastomotic healing or new vessel formation in the anastomotic region following large bowel resection.

Selective cyclo-oxygenase 2 inhibition affects ileal but not colonic anastomotic healing in the early postoperative period

BACKGROUND

Selective cyclo-oxygenase 2 (COX-2) inhibitors are increasingly prescribed in the perioperative period. Recent recognition of a possible role for COX-2 in wound healing has raised concerns about the safety of their use in surgical practice. Therefore, the influence of celecoxib, a selective COX-2 inhibitor, on early anastomotic healing was investigated.

METHODS

Celecoxib, in doses of 15, 50 or 200 mg per kg per day, was given daily from the day before operation onwards to male Wistar rats that received both ileal and colonic anastomoses. Anastomotic strength was assessed by measuring the breaking strength and bursting pressure on the third day after operation. A second group received a dose of 50 mg per kg per day and a colonic anastomosis only, and healing was assessed on the third and fifth day after surgery.

RESULTS

Expression of COX-2 protein was upregulated in the anastomotic area. Administration of celecoxib, at all doses tested, resulted in a significantly higher ileal dehiscence rate than in control rats (P = 0.002). In contrast, colonic anastomoses healed normally within the same animals. The latter was confirmed in rats with colonic anastomoses only.

CONCLUSION

In this model, administration of the COX-2 inhibitor celecoxib affected ileal but not colonic anastomotic healing in the early postoperative period.

Clinical review: Healing in gastrointestinal anastomoses, Part I

Gastrointestinal healing is a topic rarely reviewed in the literature, yet it is of paramount importance to the surgeon. Failure of anastomotic healing may lead to life-threatening complications, additional surgical procedures, increased length of stay, increased cost, long-term disability, and reduced quality of life for the patient. The goal of this article is to review the biological response to wounded tissue, to outline discrete differences between skin and gastrointestinal healing, to discuss local and systemic factors important to gastrointestinal healing, and to compare methods of measuring collagen content and strength of the newly formed anastomosis. Part II of this review will focus on techniques and therapies available to optimize anastomotic healing.

Effects of the intraperitoneal lornoxicam on the formation of intraperitoneal adhesions in rat peritonitis model

BACKGROUND

To investigate the effects of intraperitoneally administered lornoxicam on adhesion formation, bursting pressure, tissue antioxidant levels, morbidity and mortality after ileocolic anastomosis in a rat bacterial peritonitis model.

METHODS

Thirty-six rats were divided into three random groups. Bacterial peritonitis was induced by performing a cecal ligation and puncture, then the cecal was resected and ileocolic anastomosis was performed. Rats of groups 1, 2 and 3 were given 2 mL normal saline, 2 mL lornoxicam, and nothing, respectively. All groups were killed at day 14. Adhesions were scored, and the presence of intra-abdominal abscesses and fistulas were noted. Anastomotic healing was assessed by bursting pressure. Tissue antioxidant levels were tested from left abdominal walls.

RESULTS

One day after cecal ligation and puncture, microbiological examination showed polymicrobial bacterial peritonitis. The rats treated with lornoxicam had significantly lower adhesion scores than did the saline and nothing treated rats (P = 0.007). Bursting pressures of groups were unaffected by the treatment. Tissue antioxidant levels of groups were affected by the treatment. Morbidity and mortality were similar in all groups.

CONCLUSIONS

The present study demonstrated that a single intraperitoneal instillation of lornoxicam in buffer solution at the end of the surgery reduces adhesion formation in rats bacterial peritonitis model. It was also determined that lornoxicam had no negative effect on the healing of intestinal anastomosis, abscess and anastomotic leakage. Use of lornoxicam in peritonitis was effective in decreasing the oxidative stress of tissue during peritonitis.

Efeitos do Tenoxicam sobre a cicatrização da parede abdominal: estudo experimental em ratos

OBJETIVO: Analisar os efeitos do tenoxicam, um antiinflamatório não hormonal, na cicatrização da parede abdominal de ratos. MÉTODOS: Foram utilizados 40 ratos adultos, submetidos à laparotomia mediana e distribuídos, aleatoriamente, em um grupo controle (C), constituído de 20 animais que receberam solução de NaCl a 0,9 %; e um grupo tratado (T), constituído de 20 animais que receberam o tenoxicam. Os animais de cada grupo foram divididos, conforme a data de sacrifício, em subgrupos de 10 animais, denominados C7, C14, T7 e T14. As inscrições 7 e 14 determinaram o sacrifício dos animais no sétimo e décimo quarto dia pós-operatório, respectivamente. As soluções de tenoxicam (1mg/ml) e de NaCl a 0,9% foram administradas no pós-operatório imediato e nos quatro dias seguintes, por via intramuscular, na dose volume de 0,6 ml/kg/dia. No dia do sacrifício, realizou-se a ressecção de dois fragmentos da parede abdominal (1cm x 3cm), que foram utilizados para determinação da concentração de hidroxiprolina e avaliação da força de ruptura. RESULTADOS: Não foram observadas complicações da ferida operatória, incluindo infecção ou deiscência, nos quatro subgrupos de animais. Na análise comparativa dos quatro subgrupos de animais, não foi evidenciada diferença estatisticamente significante no estudo da força de ruptura (p=0,262) e na concentração de hidroxiprolina (p=0,392). CONCLUSÃO: A administração de tenoxicam, por via intramuscular, não interfere na cicatrização da parede abdominal de ratos.

Análise histológica da cicatrização da anastomose colônica, em ratos, sob ação de enema de Aroeira-do-sertão (Myracrodruon urundeuva fr. all.) a 10%

OBJETIVO: Avaliar, do ponto de vista histológico, a ação do extrato aquoso da aroeira-do-sertão na cicatrização da anastomose colônica, em ratos Wistar. MÉTODOS: Foram utilizados 48 ratos da linhagem Wistar, machos, com peso médio de 320g, distribuídos em dois grupos, com 24 animais, cada. Todos os animais foram submetidos à secção transversa completa do cólon descendente, seguida de anastomose colônica. Os ratos do grupo A receberam diariamente no pós-operatório enemas de veículo à base de carboximetilcelulose (CMC). Os animais do grupo B receberam no pós-operatório enemas de extrato aquoso de aroeira-do-sertão a 10% em veículo à base de CMC, até a data da eutanásia. Nas datas 3, 7, 14 e 21 do experimento, seis ratos de cada grupo foram submetidos à remoção de segmento colônico, incluindo a anastomose, destinado à apreciação histológica e análise qualitativa da resposta celular inflamatória e cicatricial. RESULTADOS: A análise morfológica revela diferença significante entre os grupos, no dia 7 (ñ < 0,05), quando o grupo estudado apresentou menor escore que o grupo controle. A deposição do colágeno no grupo aroeira foi menor, nos dias 3, 7 e 14 (ñ < 0,05), em relação ao grupo controle. CONCLUSÃO: O extrato aquoso da aroeira-do-sertão tem ação antiinflamatória. Também possui efeito inibitório na deposição do colágeno nas fases inflamatória e de fibroplasia no processo cicatricial de anastomoses colônicas, em ratos Wistar, porém em fases avançadas (dia 21) a cicatrização se dá de forma semelhante aos animais do grupo controle.

Effects of a selective cyclo-oxygenase 2 inhibitor on colonic anastomotic and skin wound integrity

BACKGROUND

Selective inhibitors of inducible cyclo-oxygenase (COX-2) are of potential benefit in the perioperative period for both their analgesic and, perhaps, antineoplastic actions. However, their effects on laparotomy and intestinal wound healing are unknown.

METHODS

Forty adult Sprague-Dawley rats underwent laparotomy, descending colonic transection and handsewn reanastomosis. The animals were randomized to receive either a selective COX-2 inhibitor (rofecoxib, 10 mg/kg) or an equal volume of water by gavage before operation and then daily after surgery. Animals were killed after 3 or 7 days, and their wounds were evaluated by means of tensiometry (skin and colonic wounds) and bursting pressure measurement (colonic anastomoses). In addition, haematoxylin and eosin-stained intestinal sections were examined and scored by a blinded independent observer.

RESULTS

Five animals that received rofecoxib had anastomotic leaks by day 7 compared with none in the control group (P = 0.048). Intact colonic suture lines were also significantly weaker in this group (tensile strength at day 3, P = 0.043; bursting pressure on days 3 and 7, both P = 0.019). Skin wound strengths were similar in the two groups at both time points.

CONCLUSION

Although beneficial in the treatment of pathological inflammation, selective COX-2 inhibitors may adversely affect colonic anastomotic healing.

Edema quantification by computerized morphometry as an evaluation parameter for the resistance of colon anastomoses

PURPOSE: This work had the objective of verifying the validity of using computerized morphometry as a method of quantitative analysis of the interference of edema in scar formation following colon anastomosis. METHODS: Forty-five adult female Wistar rats were utilized, divided into three groups of 15 animals according to whether sacrifice was performed on the first, second or seventh postoperative day. Each group was subdivided into a main group consisting of 10 animals, and a control group consisting of five animals. In the main group, in addition to the quantitative computerized morphometric analysis of the edema in the submucosal layer, the resistance of the colon anastomosis to bursting strength was verified. In the control group, edema quantification was studied alone. RESULTS: The results found via the computerized morphometry method showed that there is a 7% decrease in the presence of edema during the first postoperative week. They confirmed that there is an inverse statistically significant relationship (p< 0.001) between edema presence and the resistance of the anastomosis to bursting strength. CONCLUSION: The use of computerized morphometry is a reliable, fast, objective and low-cost methodology for the quantification of edema in colon anastomoses.

Impairments to wound healing

Impaired wound healing is a complication faced by all physicians, regardless of their field of practice. Plastic surgeons are frequently called on to help treat patients who fail to heal properly. Therefore, plastic surgeons must be well versed in the intrinsic and extrinsic factors that can impair wound healing, such as nutrition, drugs, radiation, smoking, and hypoxia. Only by limiting detrimental factors can wound healing progress in a beneficial fashion.

Effects of antiadhesive agents on the healing of intestinal anastomosis

PURPOSE

The effects of antiadhesive agents on the healing of intestinal anastomosis were investigated.

METHODS

Eighty rats were divided into eight groups. Colotomy and anastomosis were performed to all rats. Saline solution (control), carboxymethylcellulose, aprotinin, verapamil, tenoxicam, cyclosporine, and dextran 70 were administered intraperitoneally. Vitamin E was administered intramuscularly. The rats were killed 15 days later. Anastomotic healing was assessed by bursting pressure and the hydroxyproline content of the anastomotic tissues. The results were evaluated by Mann-Whitney U test.

RESULTS

The mean (+/- standard deviation) bursting pressures of carboxymethylcellulose, cyclosporine, and aprotinin groups (108 +/- 6.73, 122.5 +/-14.39, and 127 +/- 20.23, respectively) were significantly lower than those of the control group (234 +/- 6.19). The mean level of hydroxyproline in the anastomotic tissues was significantly lower in the carboxymethylcellulose and cyclosporine groups (8.92 +/- 0.6 and 8.32 +/- 0.63) than that in the control group (16.33 +/- 0.68).

CONCLUSION

These findings indicate that carboxymethylcellulose and cyclosporine had adverse effects on intestinal anastomosis in rats.

EFEITO DO DICLOFENACO DE SÓDIO NA CICATRIZAÇÃO DA PAREDE ABDOMINAL DE RATOS

O objetivo deste trabalho foi avaliar o efeito do diclofenaco de sódio na cicatrização da parede abdominal de ratos. Foram utilizados 40 (quarenta) ratos machos Wistar, submetidos a laparotomia com técnica padronizada, distribuidos em dois grupos, um grupo controle e outro onde se administrou o diclofenaco de sódio - 3 mg/kg/dia, via intramuscular durante 4 (quatro) dias consecutivos. Ao sétimo e ao décimo quarto dias de pós operatório, respectivamente, fora realizada a eutanásia, retirando-se a camada músculo-facial abdominal envolvendo a cicatriz operatória para a realização do estudo histológico. Os segmentos foram corados por Hematoxilina-Eosina e Picrosirius Red F3BA, sendo feita observação qualitativa do processo cicatricial e quantitativa do colágeno. Os resultados encontrados foram analisados estatisticamente. Concluiu-se que a cicatriz da parede abdominal de rato tratado com o diclofenaco de sódio apresenta menor quantidade de fibras colágenas no 7<FONT FACE="Symbol">°</font> e 14<FONT FACE="Symbol">°</font> dias de pós-operatório, quando comparado a animal do grupo controle.

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The effect of the diclofenac sodium (DS) on the healing of anastomosis carried- out in the ileum of rats was studied. Five- hundred and nineteen Wistar rats were randomly assigned to the 4 experimental groups: Group I included 52 rats treated with 3 mg/kg/day of saline, administered intramusculary during 4 days, group II included 110 rats submitted to ileal anastomosis and treated with saline as described previously, group III included 52 rats treated with DS in a dose of 3 mg/kg/day, administered IM during 4 days, and group IV included 295 rats submitted to ileal anastomosis and treated with DS as prior described. In all rats from the 4 experimental groups clinical parameters and measurements of tensile strength, tissue collagen and histological analyses were documented at 4, 7, 14, and 21 postoperative days. There are no clinical alterations in group I rats all over the study. Diarrhoea was observed in 8 rats (15,4%) from group III. In this group both tensile strenght and tissue collagen were descrease when compared with group I rats. Mortality in DS treated rats submitted to ileal anastomosis was higher than those of control groups. In group IV we also observed reard in the healing, with intense PMN inflamatory response, decrease of macrophages and of tissue collagen, and mucosae regeneration. We concluded that DS is deleterious on the healing of anastomosis performed in the ileum of rats

Necrotizing soft tissue infections reported with nonsteroidal antiinflammatory drugs

BACKGROUND

Recent reports of necrotizing fasciitis in children with varicella who received a nonsteroidal antiinflammatory drug (NSAID) recall earlier concerns regarding the possibility of relationships between infections and NSAIDs. We searched the Food and Drug Administration's Spontaneous Reporting System (SRS) for necrotizing soft tissue infections reported in conjunction with the use of NSAIDs, to identify common features.

METHODS

A computer search of NSAID listings in the adverse event database recovered reports with codes for selected infection and necrosis-related diagnostic categories. From review of individual reports classified under these codes, cases were selected if the terms "necrotizing fasciitis," "necrotic," or "gangrenous" appeared in the adverse drug reaction description. Demographic, drug use, and disease course information were gathered.

FINDINGS

Thirty-three cases were identified, of which 10 were fatal. Over two-thirds of the patients were younger than 40 years. Thirty (91%) had a possible portal of entry for infection. Most received NSAIDs for acute conditions including varicella, trauma, and postoperative or postpartum pain; 7 received an NSAID by intramuscular injection. Specific NSAIDs accounting for most reports were also among those likely to be most heavily used in the relevant populations.

INTERPRETATION

Common features of these rare case reports of necrotizing soft tissue infections with NSAID use include characteristics such as age, portal of infection entry, indication for NSAID use, route of administration, and individual NSAIDs. The total number of SRS cases does not suggest that necrotizing infection is frequent with NSAIDs or likely without other risk factors. Controlled observational studies would help to define any causal contribution of these factors to the evolution of severe infection.

Healing in the gastrointestinal tract

Healing in the GI tract is rapid when free of complications: Unlike cutaneous healing, in which progress can be observed on a daily basis and intervention instituted early if necessary, healing of the intestinal anastomosis is anatomically obscured from inspection, allowing the surgeon only the patient's parameters of general well-being to judge the success of the operation. For the same reason, complications usually require re-operation, with the associated morbidity of a laparotomy and additional general anesthetic. This places a great responsibility on the surgeon to be cognizant of all the preoperative, intraoperative, and postoperative factors relating to anastomotic healing that might compromise the healing process. Bearing these in mind, along with attention to technical detail, should limit complications to an acceptable level. Patients most at risk are (1) those who perioperatively develop physiologic problems that lead to shock, hypoxia, and resultant anastomotic ischemia, (2) those with radiation-induced tissue injury, (3) those with sepsis, and (4) those with preoperative bowel obstruction. Malnourishment, malignancy, diabetes, steroids, and age also influence outcome to varying degrees. Future advancement in the field of GI healing lies in our ability to manipulate the early struggle between collagen synthesis and collagen breakdown. A profound understanding of the molecular and biochemical pathways and the factors that control them will bring us closer to this goal. Clinically, this may be accomplished by the introduction of wound healing enhancers into the anastomotic site, possibly by incorporating them into suture materials, biofragmentable anastomotic rings, or staple materials. Already much is known about the influence of different cytokines and growth factors on collagen regulation, knowledge that will help resolve many of the long-standing problems associated with GI surgery.

Healing process of laser-welded intestinal anastomosis

Intestinal welding by means of low-power laser has been reported as an efficient method for intestinal anastomosis. We designed an experimental model in rats to investigate collagen and DNA concentrations in CO2 laser-welded anastomoses as compared with those in sutured anastomoses on the 4th, 7th, and 10th postoperative days. The results revealed that DNA, total collagen, and insoluble collagen concentrations were significantly lower in the lased anastomoses than in the sutured anastomoses on the 4th postanastomotic day. On the 7th and 10th postanastomotic days, collagen concentrations increased in the laser-treated group attaining significantly higher levels than in the sutured group at that time. These findings are compatible with other studies demonstrating that laser-welded intestinal anastomoses are more prone to dehiscence during the first 4 postanastomotic days, but become at least as effective as the sutured ones with passage of time.

Aspirin use, cancer, and polyps of the large bowel

BACKGROUND

The effect of aspirin use on 490 patients with cancer of the colon, 340 with cancer of the rectum as the first primary site, and 212 patients with polyps having no coexisting malignancies was compared with that of two groups of control subjects that consisted of 524 hospital patients having no cancers and no diseases of the digestive organs and 1138 healthy visitors to the screening clinic. All subjects entered Roswell Park Cancer Institute between 1982 and 1991.

METHODS

After adjustment for adulthood lifetime duration of aspirin use, sex, age, residence, and education, the risk of having cancers and polyps of the colon or the rectum among people who had been using aspirin at least for 1 year before the illness relative to that of nonusers was estimated using multiple logistic regression procedure.

RESULTS

The odds ratio estimates showed that the risk of colorectal cancers declined progressively as the frequency of aspirin use increased compared with control groups. Among patients reporting use of aspirin two or more times a day, the odds ratio estimates for colorectal cancers were 0.33 (95% confidence interval [CI], 0.72-0.15) and 0.44 (95% CI, 1.10-0.18) compared with those of screening clinic visitors and hospital control subjects, respectively. The odds ratio for patients with polyps who had used aspirin less than once a day relative to that of nonusers was 0.28 (95% CI, 0.62-0.13) and 0.43 (95% CI, 1.09-0.17) compared with screening clinic visitors and hospital control subjects, respectively.

CONCLUSIONS

There is a risk reduction effect of aspirin use on the incidence of colorectal cancers and polyps, and this effect is dose related.

Do the pharmacodynamics of the nonsteroidal anti-inflammatory drugs suggest a role in the management of postoperative pain?

Until recently, nonsteroidal anti-inflammatory drugs (NSAIDs) were regarded as weak analgesic agents with a potent antiplatelet effect that severely limited their perioperative usefulness. However, the recent development of injectable NSAIDs has stimulated a re-evaluation of the potential role of this class of drugs in postoperative pain management. In general surgery, NSAIDs have been shown to be effective analgesics when administered after surgery, as judged by either a reduction in pain scores and/or by an opioid sparing effect. Parenteral NSAIDs alone, notably ketorolac and diclofenac, may be adequate or even preferred analgesic agents after minor surgery. In dental surgery, NSAIDs produce greater initial analgesia than steroids, although the latter produce greater suppression of swelling and less functional loss. NSAID pretreatment results in only modest suppression of swelling compared with placebo. These data suggest that the acute analgesic effects of NSAIDs in oral surgery and probably other models result from suppression of a nociceptive process, rather than a generalised anti-inflammatory effect. This view challenges the traditional association between inhibition of prostaglandin synthesis and the therapeutic effects of these drugs. The variety of NSAIDs leads to a range in half-lives from short, e.g. diclofenac (1 h), intermediate, e.g. ketorolac (5h), to long, e.g. tenoxicam (60h), which has implications for both convenience of the dosage regimen and drug accumulation. For some racemic NSAIDs (e.g. ibuprofen), metabolic 'activation' of the inactive R-enantiomer to the active S-enantiomer occurs. Renal dysfunction may increase both the plasma concentration and body residence time of NSAIDs, thereby increasing the risk of adverse effects. The concomitant effects of anaesthesia have not yet been studied. The principal concern regarding the use of perioperative NSAIDs is the risk of decreased haemostasis and wound healing. Although it has been found that NSAIDs prolong bleeding times in patients, values generally remain below the upper limits of those in generally healthy patients. Healing of gastrointestinal anastomoses may be compromised by NSAID administration but corneal healing and bone remodelling are not. There is a need for further research into the potential for renal side effects with NSAIDs in the perioperative setting, where the effects of anaesthesia and surgery may increase the risk of side effects, particularly in elderly patients. The main benefits of NSAIDs derive from opioid sparing (e.g. reduction in perioperative nausea and vomiting and improvement in ventilation), although some studies allude to an enhanced quality of analgesia from the combination compared with either NSAID or opioid alone. The question of pre- vs postinjury treatment with NSAIDs remains unresolved.