Intraperitoneal cytostatics impair healing of experimental intestinal anastomoses

Effect of growth hormone on colonic anastomosis after intraperitoneal administration of 5-fluorouracil, bleomycin and cisplatin: An experimental study

BACKGROUND

Growth hormone (GH) plays a crucial role in wound healing and tissue repair in postoperative patients. In particular, colonic anastomosis healing following colorectal surgery is impaired by numerous chemotherapy agents.

AIM

To investigate whether GH can improve the healing of a colonic anastomosis following the adverse effects of intraperitoneal administration of 5-fluorouracil (5-FU), bleomycin and cisplatin.

METHODS

Eighty Wistar rats underwent laparotomy and a 1 cm-resection of the transverse colon, followed by an end-to-end anastomosis under general anesthesia. The rats were blindly allocated into four equal groups and administered a different daily intraperitoneal therapeutic regimen for 6 days. The control group (A) received normal saline. Group B received chemotherapy with 5-FU (20 mg/kg), bleomycin (4 mg/kg) and cisplatin (0.7 mg/kg). Group C received GH (2 mg/kg), and group D received the aforementioned combination chemotherapy and GH, as described. The rats were sacrificed on the 7th postoperative day and the anastomoses were macroscopically and microscopically examined. Body weight, bursting pressure, hydroxyproline levels and inflammation markers were measured.

RESULTS

All rats survived until the day of sacrifice, with no infections or other complications. A decrease in the body weight of group D rats was observed, not statistically significant compared to group A (P = 1), but significantly different to groups C (P = 0.001) and B (P < 0.01). Anastomotic dehiscence rate was not statistically different between the groups. Bursting pressure was not significantly different between groups A and D (P = 1.0), whereas group B had a significantly lower bursting pressure compared to group D (P < 0.001). All groups had significantly more adhesions than group A. Hydroxyproline, as a measurement of collagen deposition, was significantly higher in group D compared to group B (P < 0.05), and higher, but not statistically significant, compared to group A. Significant changes in group D were recorded, compared to group A regarding inflammation (3.450 vs 2.900, P = 0.016) and fibroblast activity (2.75 vs 3.25, P = 0.021). Neoangiogenesis and collagen deposition were not significantly different between groups A and D. Collagen deposition was significantly increased in group D compared to group B (P < 0.001).

CONCLUSION

Intraperitoneal administration of chemotherapy has an adverse effect on the healing process of colonic anastomosis. However, GH can inhibit the deleterious effect of administered chemotherapy agents and induce colonic healing in rats.

Covering the colon anastomoses with amniotic membrane prevents the negative effects of early intraperitoneal 5-FU administration on anastomotic healing

PURPOSE

This study investigated whether covering the colonic anastomoses with amniotic membrane (AM) protects the anastomotic healing from the adverse effects of immediate 5-fluorouracil (5-FU) administration.

METHODS

One hundred twenty wistar albino rats were randomized to one of four groups (I-IV, 30 rats in each) and underwent a standardized left colon resection and anastomoses. The anastomoses of the rats in groups II (AM) and IV (5-FU + AM) were covered with AM. Saline solution (2 ml/day; groups I (control) and II) or 5-FU (20 mg/kg/day; groups III (5-FU) and IV) was administered to the rats intraperitoneally once daily from the day of operation until sacrificed. Half of each group was sacrificed on the postoperative day 4 (IA, IIA, IIIA, and IVA) and other half on the postoperative day 8 (IB, IIB, IIIB, and IVB), and their anastomoses were evaluated when sacrificed.

RESULTS

The dehiscence rate of anastomotic dehiscence and adhesion formation were significantly higher in groups IIIA and IIIB compared with groups IVA and IVB, respectively. Bursting pressure was significantly higher in the 5-FU + AM groups than in the 5-FU groups. The inflammatory cell infiltration was significantly lower in groups IIIA and IVA compared with group IA, in groups IIIB and IVB compared with group IB, and in group IVA compared with group IIIA. Neoangiogenesis, fibroblast activity, collagen deposition, and hydroxyproline levels were significantly higher in the 5FU + AM groups compared with control and 5-FU groups. Malondialdehyde levels were significantly higher in the 5-FU groups than in the 5-FU + AM groups.

CONCLUSION

Covering colon anastomoses with AM protects them, preventing leakage and reversing the negative effects of 5-FU administration.

Effects of oxaliplatin and 5-fluorouracil on the healing of colon anastomoses

PURPOSE

Oxaliplatin (OX) and 5-fluorouracil (5-FU) are the most widely used chemotherapeutic agents in the adjuvant treatment of colon cancer. Although the early initiation of adjuvant chemotherapy can improve the outcome of surgery, it carries potentially fatal risks. This experimental study investigates the effects of 5-FU and OX on colon anastomoses.

METHODS

We used 60 rats, divided into six groups. After being subjected to bowel resection and anastomosis, the rats were given 5-FU on days 1-3, or OX 130 mg/m(2) on days 1 or 5, or 5% dextrose as a control. The bursting pressures and hydroxyproline content of the anastomoses were measured, and complications and adhesions were recorded.

RESULTS

There were no major complications in the treatment groups. The bursting pressures of the 5-FU group were significantly lower than those of the control and OX groups. The bursting pressures of the OX groups were not significantly different from those of the control groups. The hydroxyproline levels of the rats treated with OX on day 1 were significantly lower than those of the rats treated with OX on day 5 and the 5-FU groups.

CONCLUSION

Oxaliplatin and 5-FU did not compromise wound healing of the colon significantly. Our results indicate that OX is less detrimental to the healing of colonic anastomoses, when administered on days 1 and 5 after resection, than 5-FU.

Mycophenolate mofetil impairs healing of left-sided colon anastomoses

INTRODUCTION

Inadequate healing and consequent leakage from bowel anastomoses are a significant cause of postoperative morbidity and mortality. Immunosuppressive drugs are known to disturb healing processes and to impair the mechanical stability of bowel anastomosis. Mycophenolate mofetil (MMF) is an immunosuppressive agent that selectively inhibits the proliferation of T and B lymphocytes and has been shown to be effective in preventing allograft rejection after organ transplantation. Adverse effects are few; however, nothing is known in regard to possible adverse effects of MMF administration on the healing of bowel anastomosis. The aim of the present study was to evaluate the effect of systemic MMF administration on the healing of colon anastomoses in rats.

METHODS

Rats underwent laparotomy, division of the left colon, and sigmoidostomy. MMF (25 mg/kg) or vehicle was administered intraperitoneally in two groups (n=21 per group) 3 days before surgery and then once daily until euthanization (7 animals per group; 2, 4, and 6 days after surgery). Bursting pressure measurements, histologic evaluation, morphometric analysis, mucin and collagen staining, and BrdU immunohistochemistry of the anastomotic site were performed. Furthermore, matrix protein expression at the anastomotic site was determined by collagen I and fibronectin Western blots.

RESULTS

Administration of MMF significantly decreased anastomotic bursting pressure postoperatively. Accordingly, histology, mucin staining, and BrdU immunohistochemistry and measurements of the colonic crypt depth showed more extended inflammation, a significantly lower proliferation rate, and a significantly thinned mucosal layer in the MMF-treated groups when compared to control animals, whereas matrix synthesis at the anastomotic site was not different.

CONCLUSIONS

The administration of the immunosuppressive agent MMF significantly impairs healing and mechanical stability of colon anastomosis in rats during the early postoperative period. MMF act to disturb host reparative processes mainly by impairment of reparative colonic epithelium proliferation and less by a disturbance of matrix synthesis.

Comparison of the effects of various anticancer agents on intestinal anastomosis after intraperitoneal administration

In this study, the effects of intraperitoneal 5-fluorouracil (5-FU), cisplatinum (Cis), adriamycin (Adr), and methotrexate (MTX) administration on rat intestinal anastomosis were compared. Cis and MTX led to significant weight loss in the first 5 days compared with the control group. Within 14 days all rats except the MTX group nearly reached their preoperative weight. No remarkable weight loss or systemic toxicity was observed among the 5-FU and Adr groups. The anastomosis bursting pressure (ABP) at 1 week was significantly lower than that of the control group (P < 0.01 and P < 0.005, respectively). On day 14 the anastomosis bursting pressure in the Cis group was similar to that of the control group but was significantly lower in the MTX group (P < 0.002). Histopathologically, MTX avoided the development of a mucosal layer at the anastomosis site and led to ulcer formation in some of the rats. The ABPs at 7 and 14 days were similar to those in the control group. Neither of the agents had any significant mechanical or histopathologic adverse effects on anastomosis. According to the results of our study, MTX impaired the healing of the anastomosis, and we thus conclude that the intraperitoneal administration of this agent is not safe. On the other hand, Cis showed a detrimental effect on the anastomosis, particularly in the early phase, but this effect disappeared in the late phase. Cis thus should not be administered in the early postoperative phase. As a result, 5-FU and Adr were found to be the safest agents as they did not delay wound healing and did not reduce the anastomotic strength.

Beneficial effect of Iloprost on impaired colonic anastomotic healing induced by intraperitoneal 5-fluorouracil infusion

PURPOSE

5-Fluorouracil is the most effective chemotherapeutic agent in the management of patients with systemic colorectal cancer. Studies in recent years discussed the gradually increasing benefits of 5-fluorouracil within adjuvant chemotherapy protocols after complete surgical resections. However, many studies also have demonstrated that 5-fluorouracil impairs wound-healing on colonic anastomoses.

METHODS

In our experimental study, we examined the influence of intraperitoneal 5-fluorouracil on healing of colonic anastomoses and, also, attempted to discover whether Iloprost (PGI2 analog, a potent vasodilator with confirmed cytoprotectivity and inhibitor of thrombocyte aggregation) counteracts impaired wound-healing induced by 5-fluorouracil. A total of 80 Wistar-Albino male rats were separated into four groups. From the day of the operation, Group A received intraperitoneal saline solution, Group B received 20 mg/kg 5-fluorouracil intraperitoneally, Group C received 20 mg/kg 5-fluorouracil plus 2 microg/kg Iloprost intraperitoneally, and Group D received 2 microg/kg Iloprost intraperitoneally. Each group was divided into two subgroups, and both subgroups were killed on the third and seventh postoperative days, respectively. The subjects were measured for anastomose bursting pressures and tissue hydroxyproline levels, and wound-healing was evaluated histopathologically. Statistical evaluations among each group were made with Student's t-test and Pearson's chi-squared tests.

RESULTS

Iloprost had an accelerating effect on normal colonic anastomose wound-healing histopathologically, had no significant difference on bursting pressures and hydroxyproline levels, and significantly improved the impaired healing effect of 5-fluorouracil.

CONCLUSIONS

Our study showed a positive effect of Iloprost on the healing of colon anastomosis and, more importantly, if wound-healing is impaired by a chemotherapeutic agent, Iloprost counteracts and reverses the effect. [Key words: 5-Fluorouracil; Healing of colon anastomoses; Iloprost

The effects of 5-fluorouracil and interferon-alpha on early healing of experimental intestinal anastomoses

The continuing search for effective adjuvant therapy after resection of intestinal malignancies has prompted a growing interest in both immediate post-operative regional chemotherapy and the combination of 5-fluorouracil (5-FU) and interferon-alpha as drugs of choice. We have compared the effects of both compounds, alone and together, on early healing of intestinal anastomoses. Four groups (n = 26 each) of rats underwent resection and anastomosis of both ileum and colon: a control group and three groups receiving intraperitoneal 5-FU, interferon-alpha or both on the day of surgery and the next 2 days. Animals were killed 3 or 7 days (n = 10 each) after operation in order to measure anastomotic strength and hydroxyproline content. The remaining six animals in each group were used to study anastomotic collagen synthetic capacity at day 3. Three days after operation, ileal anastomotic bursting pressure was lowered by 37% in the 5-FU/interferon-alpha group (P = 0.0104). At day 7, anastomotic breaking strength was reduced significantly in ileum (P = 0.0221) and colon (P = 0.0054) of the 5-FU/interferon-alpha group and in colon of the interferon-alpha group (P = 0.0221). Collagen synthetic capacity was strongly suppressed by 5-FU but not by interferon-alpha. However, no differences in anastomotic hydroxyproline content were observed between groups at both days 3 and 7. Thus, post-operative use of interferon-alpha, in particular in combination with 5-FU, may be detrimental to anastomotic repair in the intestine.

Anastomotic leak after double-stapled low colorectal resection

PURPOSE

Anastomotic leaks after double-stapled low anterior resection were associated with a number of factors related to patient condition, level of anastomosis, and variety of surgery-related and antitumor therapy-related factors. This retrospective analysis of a group of patients with consistent length of rectal stump was undertaken to determine the risk factors of anastomotic leak after low colorectal resection related to surgery and to intraperitoneal chemotherapy.

METHODS

A group of 165 patients treated with surgery only, surgery with early postoperative intraperitoneal chemotherapy, and surgery with hyperthermic intraoperative and early postoperative intraperitoneal chemotherapy. All patients underwent surgery that used the double-stapled technique with transection of the rectum through its middle third. In univariate and multivariate analysis, the relationship between anastomotic leak rate and extent of colon resection, length of residual colon, presence of left colon, and type of applied treatment was studied.

RESULTS

With a full length of residual colon, leak rate was 1 percent but increased progressively with the extent of proximal colon resection. Removal of the left colon was associated with the 2.7 odds ratio for anastomotic disruption. Leak rate after surgery only was 6 percent; surgery with normothermic intraperitoneal chemotherapy was 5 percent; and surgery with heated intraperitoneal chemotherapy was 20 percent.

CONCLUSIONS

In this group of patients with consistent length of residual rectum, the incidence of anastomotic disruption was related to extent of proximal colon resection. Anastomotic integrity was not compromised by normothermic intraperitoneal chemotherapy. Hyperthermic intraperitoneal chemotherapy was associated with high leak rate only when extensive resection of the colon was performed. Variables other than extent of rectal excision are important in causing a leak of colorectal anastomosis.

Analysis of morbidity and mortality in 60 patients with peritoneal carcinomatosis treated by cytoreductive surgery and heated intraoperative intraperitoneal chemotherapy

BACKGROUND

Peritoneal carcinoma has been regarded as a uniformly lethal clinical entity. A treatment plan combining cytoreductive surgery and heated intraoperative intraperitoneal chemotherapy (HIIC) was devised and tested to treat such patients. The purpose of this study was to evaluate the morbidity and mortality associated with this treatment approach.

METHODS

Sixty patients with peritoneal carcinomatosis from adenocarcinoma of the colon or appendix were included in the study. Extensive cytoreductive surgery was combined with heated intraperitoneal mitomycin in an intraoperative lavage technique followed by one cycle of early postoperative intraperitoneal 5-fluorouracil. Eleven clinical variables were selected and statistically correlated with morbidity and mortality.

RESULTS

Twenty-five complications occurred in 21 patients (morbidity = 35%). Morbidity related to gastrointestinal function included anastomotic leak (n=6), bowel perforations (n=5), bile leak (n=3), and pancreatitis (n=2). Four patients presented with severe hematologic toxicity (Grade 3 or 4). There were three cases of postoperative bleeding, one case of abdominal wound dehiscence, and one case of pulmonary embolism. Morbidity was significantly associated with three clinical factors: male sex, high intraabdominal temperature during HIIC, and duration of the surgical procedure. Enteral complications (bowel fistula and anastomotic leak) occurred in patients with a significantly higher number of peritonectomy procedures and a significantly longer operation. Three patients died within 8 weeks after the procedure (mortality = 5%). Mortality was significantly associated with age and intraabdominal temperature.

CONCLUSIONS

Cytoreductive surgery combined with HIIC is associated with a 35% morbidity rate and a 5% mortality rate. Extensive surgery (duration and number of peritonectomy procedures) and high intraabdominal temperature represent the major risk factors for postoperative morbidity and mortality of patients treated with this new therapeutic approach.

Effect of 5-fluorouracil and leucovorin on the integrity of colonic anastomoses in the rat

PURPOSE

This study was designed to determine the effects of 5-fluorouracil and leucovorin on the healing of colonic anastomoses and assess the safety of conducting a colonic resection and anastomosis during and shortly after a course of this chemotherapy in a rat model.

METHODS

Fifty-six male Wistar rats, weighing 200 to 250 gm, were divided into four groups, each consisting of 14 animals. Animals in Group I (control group) underwent colon resection and primary anastomosis. Animals in Group II received 10 mg/kg intravenous 5-fluorouracil and 10 mg/kg leucovorin once a week for four weeks and then underwent the same operation. Animals in Groups III and IV received the same drug dosage for six weeks and were operated at different intervals: Group III at one week and Group IV at two weeks after completion of chemotherapy. Within each group, one-half of the animals were sacrificed on the third postoperative day and one-half on the seventh postoperative day, and anastomotic bursting pressure measurements were performed.

RESULTS

At three and seven days, mean bursting pressure of the anastomoses were determined: 98 mmHg and 180.7 mmHg in Group I, 95 and 197.8 in Group II, 85.7 and 189.2 in Group III, and 98.6 and 179.2 in Group IV, respectively. There was no significant difference in bursting pressure between treated animals and controls by the third postoperative day or by the seventh day. The burst occurred at the anastomosis in all specimens tested on the third postoperative day and in the bowel wall adjacent to the anastomosis in all specimens tested on the seventh postoperative day.

CONCLUSION

This study demonstrates that the above regimen of chemotherapy has no effect on the healing of colonic anastomoses and that surgery can be performed safely during and shortly after this regimen of chemotherapy.

Post-operative levamisole may compromise early healing of experimental intestinal anastomoses

There exists growing interest in immediate post-operative local adjuvant therapy after resection of intestinal malignancies. It is therefore necessary to assess it potential effect on the healing of intestinal anastomoses. Five groups (n = 20) of rats underwent resection and anastomosis of both ileum and colon: a control group and four experimental groups receiving intraperitoneal 5-fluorouracil (5-FU), 5-FU plus leucovorin, 5-FU plus levamisole or levamisole alone, on the day of surgery and the next 2 days. Animals were killed 3 or 7 days after operation. Another three groups (n = 6) of animals were used to compare anastomotic collagen synthetic capacity in control rats or rats receiving 5-FU or 5-FU plus levamisole. On the third post-operative day, the average anastomotic bursting pressure in the 5-FU/levamisole group was reduced by 36% as compared with the control group, both in ileum (P = 0.02) and in colon (P = 0.01). Values in the other groups were similar to those in the control group. Anastomotic breaking strength was significantly (P < 0.025) lowered in the ileum from the levamisole group at both days 3 and 7. Anastomotic collagen synthetic capacity was strongly reduced in the 5-FU and 5-FU/levamisole groups. However, there was no significant difference between the control group and the four experimental groups with regard to anastomotic hydroxyproline concentration and content, either 3 or 7 days after operation. Thus, limited use of levamisole, alone or in combination with intraperitoneal 5-FU, may compromise intestinal healing.

Early post-operative 5-fluorouracil does not affect the healing of experimental intestinal anastomoses

5-Fluorouracil (5-FU) remains the mainstay for systemic treatment of colorectal cancer. In view of the increasing interest in peri-operative administration of antineoplastic agents, we have investigated the effects of early postoperative 5-FU on the healing of intestinal anastomoses in the rat. Animals underwent resection and anastomosis of both ileum and colon and 5-FU (20 mg/kg body weight) was given, either intravenously or intraperitoneally, on the day of surgery and the two subsequent days. Healing was assessed three and seven days after operation. Administration of 5-FU led to a reduced white blood cell count. However, anastomotic strength was not significantly reduced at either time point and anastomotic hydroxyproline content was not significantly affected. We suggest that limited use of 5-FU during or immediately after operation does not necessarily affect early anastomotic healing in the intestine.

Inhibition of basal and TGF beta-induced fibroblast collagen synthesis by antineoplastic agents. Implications for wound healing

Antineoplastic drugs, given in the perioperative period, are thought to be a hazard to wound repair. Since fibroblast collagen synthesis is crucial to healing, we examined the effects of bleomycin, cisplatin and 5-fluorouracil on collagen synthesis in confluent cultures of fibroblasts from human colon and skin. The drugs were added in final concentrations between 0.1 and 50 microM. Bleomycin did not affect collagen synthesis in colon fibroblasts but inhibited synthesis in skin fibroblasts. Collagen synthesis in colon fibroblasts was strongly, and specifically, inhibited by cisplatin while synthesis in skin fibroblasts was affected only slightly. 5-Fluorouracil had no effect whatsoever on the collagen synthetic capacity in either colon or skin fibroblasts. If skin fibroblasts were cultured in the presence of transforming growth factor beta (TGF beta), the antineoplastic agents inhibited the TGF beta-stimulated collagen synthesis at far lower concentrations than those needed to suppress non-stimulated synthesis. This effect was not observed in fibroblasts from colon. The possible implications of these observations, as pertain to the use of perioperative chemotherapy, are discussed. Since 5-fluorouracil did not directly affect collagen synthesis in colon fibroblasts under any of the conditions tested it is suggested that the data support the contention that this drug is relatively harmless for intestinal healing.

Collagen synthetic capacity throughout the uninjured and anastomosed intestinal wall

The capacity to synthesize collagen was measured throughout the intestinal tract of the rat, using an in vitro technique. In addition, the effect of anastomotic construction in either the ileum or the colon on collagen synthetic capacity at specific distant locations both 1 and 4 days after operation was investigated. Collagen synthetic capacity is relatively uniform throughout the large bowel. However, in the small bowel in which synthesis is lower than in the large bowel, synthesis is significantly higher in the most proximal and distal segments than in the intermediate tissue. Anastomotic construction in either part of the bowel strongly increases collagen synthetic capacity at the immediate wound site. The synthetic response is not restricted to the anastomotic site but appears to be more generalized and is, in the small bowel, to some extent specific for collagen since the collagen synthetic capacity is increased far more than the capacity to produce noncollagenous protein. Anastomotic construction in the colon has only minor, although sometimes significant, effects on collagen synthetic capacity in the ileum, and vice versa.

Intraperitoneal cytostatics impair early post-operative collagen synthesis in experimental intestinal anastomosesP6

Collagen synthesis in intestinal anastomoses has been measured in rats after in vivo administration of cytostatics. The cytostatics were administered during 5 consecutive days either intravenously or intraperitoneally. On day 3 of the course the rats received both an ileal and a colonic anastomosis. The animals were sacrificed 3 and 7 days after operation. The cytostatics regimen used was a combination of 5-fluorouracil, bleomycin and cisplatinum in a dose of 10, 2 and 0.35 mg kg-1 day-1, respectively. In an additional group, a twice higher dose was given intraperitoneally. Three days after operation a severe inhibition of the collagen synthesis was observed in all the cytostatics treated groups, both in ileum and in colon. The effects of intraperitoneal administration were much more pronounced than those observed after an equal dose given intravenously. Seven days after operation the collagen synthesis in the intravenously treated groups was restored to the level of the control group. However, in the intraperitoneal groups the collagen synthesis in ileal anastomoses was still inhibited. Thus, cytostatics suppress collagen synthesis in intestinal anastomoses. The effect is more severe after intraperitoneal than after intravenous administration, confirming our earlier hypothesis that the former mode of administration comprises a higher risk for anastomotic integrity.