Effects of intraperitoneal bevacizumab administration on colonic anastomosis and early postoperative adhesion formation

Pharmacological prevention of arthrofibrosis: a systematic review

BACKGROUND AND AIMS

Arthrofibrosis is a complication of intra-articular knee surgery which is caused by intra-articular fibrosis. To date, several preventive therapies for arthrofibrosis have been reported. This systematic review aims to summarize current knowledge about pharmacological arthrofibrosis prevention.

METHODS

A systematic literature search was conducted in Medline, Web of Science, and Cochrane library using the search term 'Arthrofibrosis AND prevention'. Subsequently, articles reporting the effects of a preventive pharmacological intervention against arthrofibrosis were included in this review.

RESULTS

16 studies investigated the pharmacological prevention of arthrofibrosis of which 13 were conducted in animal models. Several drugs improved the range of motion (ROM) in animal models. Bevacizumab (ROM +39.4 degrees), nonsteroidal anti-inflammatory drugs (ROM +18.0-31.2 degrees), and rosiglitazone (ROM +19.5 degrees) significantly increased the ROM. Artesunate, mitomycin c, bevacizumab, hyaloglide, and botulinum toxin A significantly reduced adhesion scores. None of the drugs tested in humans improved the functional outcomes after joint arthroplasty. Methodological differences limited the ability to compare outcomes and, due to poor reporting of methodology, many studies had an unclear risk of bias.

CONCLUSION

This review identified several drugs as potential candidates for arthrofibrosis prevention. These drugs modulate inflammation or alter the activity of fibroblasts. Most studies are conducted in experimental animal models and none of these results are currently translated into a clinical application. Moreover, the methodology and route of administration varied between studies. Nor were dose dependency studies conducted. Future studies should adopt a standardized approach to determine the effects of preventive pharmacological interventions on arthrofibrosis.

The anti-adhesive effect of anti-VEGF agents in experimental models: A systematic review

Adhesions constitute a major problem in abdominal-pelvic and thoracic surgery with significant impact in the postoperative quality of life and healthcare services utilization. Adhesiogenesis is the result of increased fibrin formation, impaired fibrinolysis, angiogenesis, and fibrosis. Despite the recent advancements, the ideal anti-adhesive agent remains to be determined. To this end, we performed a comprehensive literature search in PubMed, EMBASE, and Scopus databases to identify studies investigating the antiadhesive role of anti-VEGF agents in peritoneal, pleural, and pericardial experimental adhesion models. Fifteen studies were eligible for inclusion with a total population of 602 animals (334 rats, 180 rabbits, and 88 mice). The majority of included studies (11/15) used bevacizumab, while three studies used other anti-VEGF antibodies and one study used an anti-VEGFR-antibody. A rat model was used in nine studies, while rabbit (n = 3) or mouse (n = 3) models were used less frequently. Eleven studies used peritoneal models, three studies used pleural models, and one study used a pericardial model. The scales (n = 12) and interval (Range: 1-42 days) used for the evaluation of adhesions varied between the studies. All studies demonstrated a significant decrease in adhesion scores between the anti-VEGF and control groups up to 42 days postprocedure. VEGF blockade resulted in decreased fibrosis in four out of five studies that used peritoneal models, while the effect on pleural models depended on the pleurodesis agent and was significant between 7 and 28 days. The effect of anti-VEGF agents on anastomosis integrity depends on the dose and the model that is used (inconclusive results).Current data support the anti-adhesive role of Anti-VEGF agents in all three serosal surfaces up to 6 weeks postprocedure. Further studies are needed to confirm the anti-adhesive role of anti-VEGF agents in pleural and pericardial adhesion experimental models and investigate any effect on anastomosis integrity in peritoneal models.

Bevacizumab Allows Preservation of Liver Function and its Regenerative Capacity after Major Hepatectomy

BACKGROUND

Parallel to the safety of liver resections, new chemotherapy drugs have emerged for the control of liver metastases. However, there is unclear evidence about the combination of intensive BVZ-therapy and extended resections. The main aim was to analyse the impact of Bevacizumab (BVZ) in terms of liver safety and tolerability in two experimental models: a basal-toxicity situation and after major hepatectomy.

METHODS

Eighty male-Wistar rats were grouped as toxicity analysis (sham-operated rats-OS-) and regeneration after- surgery analysis (hepatectomy rats-H-). Eight further subgroups were created according to sacrifice (6- hours-6h- or 24-hours-24h-) and dose (μg) of BVZ (none, 100, 200, 400). Several measurements were performed, including biochemical serum samples, histopathological analysis, cytokines (IL-6, TNF-α, TGF-β), oxidative-stress (GSH/GSSG, ATP), lipid-peroxidation (TBARS) and epidermal and vascular endothelium growth-factors (EGF and VEGF).

RESULTS

In the toxicity analysis, safe results with BVZ were observed, with no significant differences among the groups. A trend towards a lower oxidative status was observed in the OS 6 h-100, -200 and -400 versus the OS 6 h-none group. Similar results were observed in the hepatectomy model, with stable oxidative-stress-index and IL-6, TNF- α, and TGF- β levels. Despite higher lipid peroxidation status, overall regeneration was preserved. As expected, VEGF was almost undetectable in BVZ-treated groups after resection, but not in the non-resection group.

CONCLUSION

It was concluded that liver status was not impaired by BVZ even at the high-dose. Similarly, liver regeneration after extended hepatectomy in BVZ-treated animals was well-preserved. Extended liver resections may be encouraged in BVZ-treated patients due to its excellent tolerability and good liver regeneration status.

Decrease in VEGF-Induced Pericardial Adhesion Formation Using Bevacizumab After Surgery

OBJECTIVES

Some degrees of postoperative cardiac adhesions occur in response to the first cardiac surgery in patients that may limit surgeons for subsequent operations and increase the risk of heart injury. In this article, we established a model of postoperative pericardial adhesions, and because vascular endothelial growth factor (VEGF) seems to initiate adhesion formation through inflammatory responses, we used an anti-VEGF antibody, that is, bevacizumab, to examine its effects on postoperative adhesion formation.

METHODS

Twenty Wistar rats were divided in 2 groups: control and bevacizumab. After chest opening, pericardial sac was opened and the heart was fully exposed. In the bevacizumab group, bevacizumab (2.5 mg/kg) was applied locally on the heart and then the chest was closed. The control group received saline solution as placebo. After 42 days, high-sensitivity C-reactive protein in peripheral blood was measured, and re-sternotomy was performed to measure severity of pericardial adhesions. Then, the hearts were collected from all rats to evaluate percentage of CD-31-positive cells (as a marker of angiogenesis) using immunohistochemical staining.

RESULTS

When the bevacizumab group was compared with the control group, we found that the mean score of adhesion (0.89 ± 0.38 vs 2.56 ± 0.41) and CD-31 expression (27.45 ± 3.75% vs 56.26 ± 1.98%) was decreased significantly after bevacizumab administration. However, we did not find any difference in high-sensitivity C-reactive protein levels of control and bevacizumab animals.

CONCLUSION

In the current study, bevacizumab administration could effectively reduce adhesion formation after first sternotomy by preventing VEGF-induced angiogenesis through CD-31 downregulation.

A Time Course of Bevacizumab (Anti-VEGF) Effect on Rat Peritoneum: Relations Between Antiadhesive Action and Fibrin Regulation Enzymes

BACKGROUND

To investigate the early and late antiadhesive effect and any changes of fibrin matrix regulation enzymes on rat peritoneum, after local administration of bevacizumab.

METHODS

Rats were subjected to cecal abrasion. Bevacizumab (5 mg/kg) against placebo was given intraperitoneally. On the 2nd, 14th, and 28th postoperative days adhesions were scored, and tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), degree of fibrosis, and angiogenesis were measured in abrased cecum and in intact parietal peritoneum.

RESULTS

Bevacizumab significantly reduced adhesions up to 15% on the 2nd, 52.5% on the 14th, and 55% on the 28th postoperative day, and significantly increased tPA concentrations in peritoneum. PAI-1 was decreased, and a significantly higher tPA/PAI-1 ratio along with an increase of MMP-9 was measured at all time points. Fibrosis and angiogenesis were significantly lower on the 14th and 28th postoperative days.

CONCLUSIONS

Local bevacizumab administration has a strong early and late antiadhesive action on rat peritoneum, mediated by changes in the tPA/PAI-1 and MMP balance in favor of fibrinolysis up to 28 days after operations.

Effect of intraperitoneal cetuximab administration on colonic anastomosis and early postoperative adhesion formation in a rat model

OBJECTIVE

We aimed to evaluate the effect of intraperitoneal cetuximab administration on the healing of anastomosis and development of early adhesion formation in a rat model.

MATERIALS AND METHODS

Twenty-four female rats were used. A colon segment was resected and end-to-end anastomosis was performed. The rats were randomized into three groups after the performance of colonic anastomosis and received 10 mL of intraperitoneal solution including study drugs after closure of abdominal cavity: normal saline was administered to the normal saline group (n=8), cetuximab (400 mg/m(2)) was administered to the postoperative 1 group (n=8) 1 day after surgery, and cetuximab (400 mg/m(2)) was administered to the peroperative group (n=8) during surgery.

RESULTS

The mean adhesion grade was 2.63±0.92, and 0.50±0.76 and 0.63±0.74 for control and test groups, respectively. Cetuximab reduced adhesion formation in test groups (p<0.05). When all groups were compared, it was found that vascular endothelial growth factor levels decreased significantly only in the abdomen (p<0.05). Hydroxyproline levels and anastomosis bursting pressure were examined, and a statistical difference was found between groups (hydroxyproline p<0.05, bursting pressure p<0.05). However, when postoperative 1 day group was compared with the control group, it was found that there was no difference between groups according to these parameters (p>0.05), but when peroperative group was compared with the control group a significant decrease was observed in both parameters. Histopathological healing score was also evaluated. No statistical difference between groups was found.

CONCLUSION

Twenty-four hours later from the operation, intraperitoneal cetuximab therapy may be a safe and feasible treatment for metastatic colorectal patients.

Intraperitoneal Vascular Endothelial Growth Factor: A Prognostic Factor and the Potential for Intraperitoneal Bevacizumab Use in Peritoneal Surface Malignancies

INTRODUCTION

Intraperitoneal (IP) vascular endothelial growth factor (VEGF) levels have been shown to vary in the peritoneal cavity of patients with peritoneal surface malignancies. Our purpose was to correlate levels of IP VEGF with overall and disease-free survival to identify whether IP VEGF can be used to prognosticate patients and the possible role of IP bevacizumab.

METHODS

From February to October 2012, 97 consecutive patients with peritoneal carcinomatosis were treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Intravenous (IV) VEGF levels were taken before surgery, whereas IP VEGF levels were taken at various time points during and after surgery.

RESULTS

Median follow-up was 19.48 months. On univariate analysis, a lower IP VEGF taken just after incision (T1) was associated with improved overall (P = 0.0004) and disease-free survival (P = 0.0006) at 2 years. A lower T1/IV VEGF ratio also was associated with improved overall (P = 0.004) and disease-free survival (P = 0.0051). On multivariate analysis, a lower T1 was associated with improved overall survival, whereas a lower T1/IV VEGF was associated with improved disease-free survival. On subset analysis, these two variables were associated with improved survival in colorectal cancers.

CONCLUSIONS

A lower IP VEGF level prior to surgery is associated with improved survival. The use of preoperative intraperitoneal bevacizumab for patients with a heavy disease load should be considered, especially in colorectal cancers.