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

The integrity of colonic anastomoses following the intraperitoneal administration of oxaliplatin

INTRODUCTION

The purpose of this experimental study was to determine the effect of oxaliplatin on the integrity of colonic anastomoses which were under oxaliplatin administration.

MATERIALS AND METHODS

Thirty rats were randomized to two groups. After resection of a 1-cm segment of the transverse colon, an end-to-end sutured anastomosis was performed. Rats of the control group were injected with 3 ml of 0.9% sodium chloride solution and in the oxaliplatin group with 2.4 mg/kg of oxaliplatin intraperitoneally immediately after surgery and for seven postoperative days. All rats were sacrificed on the tenth postoperative day, and the anastomoses were examined macroscopically and graded histologically. Rats were measured for anastomotic bursting pressures and tissue hydroxyproline levels.

RESULTS

The body weight changes were significantly greater in the oxaliplatin group (p = 0.005). Anastomotic dehiscence occurred only in the oxaliplatin group. The adhesion formation was significantly increased in the group of oxaliplatin compared to the control group (p = 0.001). The colonic bursting pressure was significantly lower in the oxaliplatin group compared to the control group (p < 0.001). The mean inflammatory cell infiltration was significantly lower in the oxaliplatin group (1.00 vs. 2.33, p < 0.001). The mean neoagiogenesis was significantly lower in the oxaliplatin group (0.80 vs. 2.20, p < 0.001). The mean collagen deposition was significantly lower in the oxaliplatin group and the mean fibroblast activity was significantly lower in the oxaliplatin group (1.27 vs. 2.53, p < 0.001). Hydroxyproline concentration was significantly lower in the oxaliplatin group (p < 0.001).

CONCLUSION

Intra- and postoperative intraperitoneal administration of oxaliplatin definitely impairs healing of colonic anastomoses in rats.

Changes in bowel mucosal permeability and wound healing after neoadjuvant chemotherapy

Neoadjuvant chemotherapy (NAC) with 5-fluorouracil (5-FU) and cisplatin (CDDP) is a promising approach for locally advanced gastric cancer. We investigated the influence of NAC with 5-FU/CDDP on the permeability of intestinal mucosa and wound healing. Male Sprague Dawley rats were divided into four groups (n=6). Group 1 received saline (control group) and Groups 2-4 were administered preoperative 5-FU/CDDP (NAC groups). The NAC consisted of daily intraperitoneal administration of 5-FU from day 1 to 5 and from day 8 to 12 and intravenous administration of CDDP on days 2 and 9. The rats underwent gastrotomy (1.0 cm) with a laparotomy of 3 cm in length, under general anesthesia. Seven days after surgery, the rats were orally administered with phenolsulfonphthalein (PSP), and the 24-h urinary excretion of PSP was quantified. On postoperative day 8, the bursting pressure (BP) of the gastric suture line and the tensile strength of the abdominal wound were measured. The hydroxyproline (HP) content in the tissue of the abdominal suture line was then measured, and the number of fibroblast cells in the tissue of the gastric suture line was calculated by histopathological examination. The PSP urinary excretion rate was significantly higher in Group 2 in comparison with the other groups (P<0.05), while the BP of a selected gastrorrhaphy region was significantly lower in Group 2 (P<0.05). No significant differences were noted in the HP content. NAC with 5-FU/CDDP disturbs the healing of intestinal anastomoses when the interval between chemotherapy and surgery is insufficient. Neither HP content nor fibroblast counts were correlated with BP. Consequently, NAC appeared to affect the remodeling of collagen fiber. Thus, the integrity of the intestine may play a role in intestinal wound healing.

Effect of early preoperative 5-fluorouracil on the integrity of colonic anastomoses in rats

AIM: To determine the effect of chemotherapy on wound healing by giving early preoperative 5-fluorouracil (5-FU) to rats with colonic anastomoses.

METHODS: Sixty Albino-Wistar male rats (median weight, 235 g) were used in this study. The rats were fed with standard laboratory food and given tap water ad libitum. The animals were divided into three groups: Group 1: Control group (chemotherapy was not administered), Group 2: Intraperitoneally (IP) administered 5-FU group (chemotherapy was administered IP to animals at a dose of 20 mg/kg daily during the 5 d preceeding surgery), Group 3: Intravenously (IV) administered 5-FU group. Chemotherapy was administered via the penil vein, using the same dosing scheme and duration as the second group. After a 3-d rest to minimize the side effects of chemotherapy, both groups underwent surgery. One centimeter of colon was resected 2 cm proximally from the peritoneal reflection, then sutured intermittently and subsequently end-to-end anastomosed. In each group, half the animals were given anaesthesia on the 3rd postoperative (PO) day and the other half on the 7th PO day, for in vivo analytic procedures. The abdominal incisions in the rats were dissected, all the new and old anastomotic segments were clearly seen and bursting pressures of each anastomotic segment, tissue hydroxyproline levels and DNA content were determined to assess the histologic tissue repair process.

RESULTS: When the IV group was compared with the IP group, bursting pressures of the anastomotic segments on the 3rd and 7th PO days, were found to be significantly decreased, hydroxyproline levels at the anastomotic segment on the 7th PO day were significantly decreased (P < 0.01).

CONCLUSION: In this study, we conclude that early preoperative 5-FU, administered IV, negatively affects wound healing. However, IP administered 5-FU does not negatively affect wound healing.

Healing of colonic anastomoses after immediate postoperative intraperitoneal administration of oxaliplatin

AIM

The aim of this experimental study was to investigate the effect of intraperitoneal administration of oxaliplatin on the healing of colonic anastomoses when injected immediately after colon resection.

MATERIALS AND METHODS

Thirty male Wistar rats were used. During the operation, the rats were randomized to two groups of 15 rats each. Immediately after colonic anastomoses were performed, the rats were injected intraperitoneally with either 3 ml of 0.9% NaCl solution or oxaliplatin (2.4 mg/kg body weight) depending on their group. All rats were killed on the eighth postoperative day. The anastomoses were examined macroscopically. The anastomotic bursting pressures were recorded, the anastomoses graded histologically, and the hydroxyproline tissue contents determined.

RESULTS

Anastomotic leakage was noted in four rats (26.7%) of the oxaliplatin group, whereas no anastomotic dehiscence was detected among rats of the control group (p = 0.016). The adhesion formation at the anastomotic sites and the inflammatory cell infiltration were significantly higher in the oxaliplatin group than in the control group (p = 0.001). The bursting pressures (p = 0.001), the hydroxyproline tissue content (p = 0.001), the neoangiogenesis (p = 0.033), the fibroblast activity (p = 0.001), and the collagen deposition (p = 0.001) were significantly lower in the oxaliplatin group in comparison to the control group.

CONCLUSION

The immediate postoperative intraperitoneal administration of oxaliplatin seems to impair healing of colonic anastomoses in rats.

Effect of IGF-I on healing of colonic anastomoses in rats under 5-FU treatment

BACKGROUND

The aim of this experimental study was to investigate whether insulin-like growth factor I (IGF-I) can protect the colonic healing from the adverse effects of intraperitoneal administration of 5-fluorouracil (5-FU).

MATERIALS AND METHODS

Eighty male Wistar rats were randomized into four groups of 20 rats each. Immediately after anastomoses were performed, rats in the control group were injected with 1 mL/100 gr of intraperitoneal saline solution, which was repeated daily until killed. Rats in the 5-FU and IGF-I +5-FU groups received 5-FU in a dose of 20 mg/kg body weight intraperitoneally, from the day of operation until killed. Rats in the IGF-I and IGF-I +5-FU groups received IGF-I in a dose of 2 mg/kg body weight intraperitoneally, immediately after the colonic anastomosis was performed and on 2nd, 4th, and 6th postoperative day. Rats were sacrificed on the 7th postoperative day.

RESULTS

The dehiscence rate in the 5-FU group was 30% and it was significantly higher compared with the control and the IGF-I group (P = 0.020 for both comparisons). However, in the IGF-I +5-FU group, the dehiscence rate decreased to 10%. The administration of IGF-I resulted in a significant rise of bursting pressure in the IGF-I +5-FU group compared with the 5-FU group (P < 0.001). There was no statistical difference in bursting pressure between the IGF-I +5-FU and control groups (P = 1.000). The hydroxyproline levels were higher in the IGF-I and the IGF-I +5-FU groups as a result of the stimulating act of IGF-I.

CONCLUSION

IGF-I, when given intraperitoneally, seems to mediate some of the adverse effects of 5-FU on the colonic healing in rats.

Effects of granulocyte-colony stimulating factor on peritoneal defense mechanisms and bacterial translocation after administration of systemic chemotherapy in rats

AIM: To investigate the effects of granulocyte-colony stimulating factor (G-CSF) on peritoneal defense mechanisms and bacterial translocation after systemic 5-Fluorouracil (5-FU) administration.

METHODS: Thirty Wistar albino rats were divided into three groups; the control, 5-FU and 5-FU + G-CSF groups. We measured bactericidal activity of the peritoneal fluid, phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid, total peritoneal cell counts and cell types of peritoneal washing fluid. Bacterial translocation was quantified by mesenteric lymph node, liver and spleen tissue cultures.

RESULTS: Systemic 5-FU reduced total peritoneal cell counts, neutrophils and macrophage numbers. It also altered bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. 5-FU also caused significant increase in frequencies of bacterial translocation at the liver and mesenteric lymph nodes. G-CSF decreased bacterial translocation, it significantly enhanced bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. It also increased total peritoneal cell counts, neutrophils and macrophage numbers.

CONCLUSION: Systemic 5-FU administration caused bacterial translocation, decreased the bactericidal activity of peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid. G-CSF increased both bactericidal activity of the peritoneal fluid and phagocytic activity of polymorphonuclear leucocytes in the peritoneal fluid, and prevented the bacterial translocation. We conclude that intraperitoneal GCSF administration protects the effects of systemic 5-FU on peritoneal defense mechanisms.

Effects of induction therapy on wound healing at bronchial anastomosis sites in rats

OBJECTIVES

Preoperative chemotherapy is frequently used for advanced lung cancer. As a valid alternative to pneumonectomy, bronchoplasty has the advantage of enabling lung parenchyma function to be preserved. The effects of antineoplastic agents on healing bronchial anastomosis remain unclear. We studied the effects of preoperative chemotherapy on wound healing in bronchial anastomoses and clarified causes of wound healing impairment in rats.

METHODS

In experiment I, at 3 days before surgery, rats were injected with cyclophosphamide, doxorubicin, and vincristine (CAV group) or cisplatin and etoposide (PVP treated rats). In experiment II, at 48 hrs before surgery, rats were treated with rabbit antirat macrophage serum and antirat monocyte chemoattractant protein-1 antibody to inhibit macrophage infiltration. On days 3, 5, and 7 after bronchus anastomosis, wound healing was assessed by examining bursting strength and hydroxyproline tissue content.

RESULTS

CAV-treated rats showed significant impaired wound healing, marked severe leucopenia, and reduced macrophage infiltration. The PVP group showed no significant changes. In experiment II, rats exhibited inhibited macrophage infiltration, which is associated with significantly impaired of wound healing.

CONCLUSIONS

Our study suggests that induction chemotherapy, associated with leukopenia in the early phase of wound healing, increases the risk of bronchial anastomosis leakage. Postoperative macrophage depletion is one of the most important causes of impaired wound healing.

Influence of 5-fluorouracil on colonic healing and expression of transforming growth factor-beta 1

BACKGROUND

Administration of chemotherapeutic agents in the immediate postoperative period may have beneficial effects by decreasing local cancer recurrence rates, but this must be weighed against possible impairment of wound healing. Since local expression of transforming growth factor-beta1 (TGF-beta1) is normally upreglated following creation of experimental colonic anastomoses, this study examines the effects of 5-fluorouracil (5-FU) on colonic healing and on the local expression of TGF-beta1.

MATERIALS AND METHODS

Forty-eight male Sprague-Dawley rats underwent transection of the descending colon with primary anastomosis and were then randomly assigned to receive either intraperitoneal 5-FU (20 mg/kg/day) or saline (SAL). On Postoperative Days (PODs) 3, 5, and 7, bursting pressure (BP, mm Hg) and bursting energy (BE, mm Hg xs) were determined in situ. Anastomotic and nonoperated segments of colon were harvested and analyzed using the semiquantitative reverse transcriptase-polymerase chain reaction to determine the relative expression of TGF-beta1 normalized to that of a constitutive gene.

RESULTS

Progressive increases in BP and BE were observed in both the 5-FU and the SAL groups, across the time course examined. Overall, these measures were decreased in the 5-FU groups compared to SAL, significantly so on PODs 5 and 7; BP, 127.8 +/- 7.6 vs 161.1 +/- 7.2 and 139.9 +/- 10.9 vs 186.0 +/- 8.6; BE, 1093.6 +/- 190.0 vs 2207.9 +/- 308.2, and 1518.5 +/- 326.5 vs 3279.3 +/- 225.7, respectively. Anastomotic TGF-beta1 expression also increased progressively in both groups over the postoperative time course. Expression in the 5-FU group, however, was significantly decreased compared to that in the SAL group on POD 3; 0.42 +/- 0.05 vs 0.84 +/- 0.04. Interestingly, this preceded the reduction in BP and BE in the 5-FU group on PODs 5 and 7. TGF-beta1 expression in nonoperated colonic segments did not change during the time points studied or in response to 5-FU administration.

CONCLUSIONS

Wound healing following a colonic anastomosis is associated with local increases in TGF-beta1 expression, which in turn is diminished by the administration of 5-FU. If this deleterious effect on wound healing could be counteracted, then chemotherapy administration in the immediate postoperative period may become safer.

Immediate postoperative 5-FU does not decrease colonic anastomotic strength

BACKGROUND AND OBJECTIVES

The use of continuous infusion 5-Fluorouracil (5-FU) immediately after surgery may improve the adjuvant treatment of resected colon cancer and is the subject of a national phase III trial (Intergroup no. 0136). The aim was to determine the effect of continuous infusion 5-FU on the bursting pressure of a colon anastomosis.

METHODS

Twenty Lewis rats weighing approximately 300 g were subject to sigmoid colectomy and single-layer anastomosis. Ten rats received 5-FU continuously at 600 mg/m2 per day for 7 days; 10 rats served as controls. Ten days postoperatively, the rats were sacrificed and bursting pressure of the colon containing the anastomosis was determined.

RESULTS

No anastomotic leaks or intra-abdominal abscesses were identified. Burst pressure of the colon in controls (124+/-13 mm Hg; mean+/-SEM) was not significantly different from those animals receiving 5-FU (115+/-9, P > 0.05). The control rats gained weight (13+/-7 g), which is significantly different from the rats receiving 5-FU (-19+/-13, P=0.04).

CONCLUSIONS

Continuous infusion 5-FU postoperatively results in weight loss, but does not affect anastomotic bursting strength in rats. This evidence supports the safety of continuous infusion 5-FU postoperatively in humans.

Experimental study of the effect of preoperative 5-fluorouracil on the integrity of colonic anastomoses

BACKGROUND

Despite curative resection for colorectal cancer, many patients develop recurrence at the primary site or distant organs. These patients are candidates for (neo)-adjuvant chemotherapy. Very little is known about the effect of preoperative 5-fluorouracil (FU) on the healing of colonic anastomoses. The aim of this study was to assess this in a rat model.

METHODS

Eighty male Wistar rats, weighing 160-215 g, were divided into three groups; (1) a control group underwent left colon resection and primary anastomosis (n = 20); (2) a sham group received 1 ml saline intraperitoneally (n = 30); (3) a study group received 5-FU intraperitoneally (20 mg kg-1). Both saline and 5-FU injections were given intraperitoneally for 5 days before operation.

RESULTS

There was no difference in the rate of wound complications, intraperitoneal adhesions and anastomotic complications among the groups. Three and seven days after operation, mean bursting pressure of the anastomosis was 36.5 and 198 mmHg in group 1, 34 and 200 mmHg in group 2, and 39 and 190 mmHg in group 3 respectively (P not significant). Although the myeloperoxidase and hydroxyproline content were significantly lower after 5-FU therapy (P < 0.01, compared with others), the clinical outcome was similar.

CONCLUSION

Preoperative 5-FU consecutive days before operation had no effect on the healing of colonic anastomoses.

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.