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

Effects of CO(2) pneumoperitoneum on anastomotic healing in rats receiving preoperative 5-fluorouracil neoadjuvant chemotherapy

BACKGROUND

When used separately, antineoplastic agents and carbon dioxide (CO(2)) pneumoperitoneum have been reported to impair anastomotic healing in experimental animals. However, the effects of their combined use have not been previously investigated. The aim of this study was to investigate the possibility that neoadjuvant chemotherapy with 5-fluorouracil followed by CO(2) pneumoperitoneum would affect the healing of anastomoses in the colon.

METHODS

Sprague-Dawley rats (n = 48) were given 5-fluorouracil (20 mg/kg/day) for 5 days, and were then assigned to one of the three groups. Prior to surgery, the control group received no pneumoperitoneum. The other two groups received pneumoperitoneum at 6 and 12 mmHg, respectively, for 2 hr. The large intestine was transected and anastomosis was performed via median laparotomy. On postoperative days 3 and 7, relaparotomy was performed in half of the rats in each group. From the colon, a segment including the anastomosis was excised. Tissue hydroxyproline levels were measured. For histological evaluation, the Verhofstad scale was modified and used.

RESULTS

No significant differences in hydroxyproline levels were seen across the groups on postoperative days 3 or 7. However, by postoperative day 7, polymorphonuclear leukocytes and necrosis in the 6-mmHg group had decreased markedly, and granulation had improved.

CONCLUSION

Overall, these findings suggest that preoperative 5-fluorouracil therapy followed by pneumoperitoneum at 6 or 12 mmHg does not impair anastomotic healing.

Sciatic nerve resection in the thigh: a functional evaluation

Patients with a soft tissue malignancy involving the sciatic nerve who present with neurologic loss generally are advised to have an amputation. Twenty patients who underwent limb-sparing procedures with complete resection of the sciatic nerve as treatment for neurofibrosarcomas (12 patients), liposarcomas (four patients), malignant fibrous histiocytomas (two patients), recurrent desmoid tumor (one patient), and epithelioid hemangioendothelioma (one patient) were reviewed retrospectively. The mean age of these nine women and 11 men at the time of surgery was 51 years (range, 28-84 years). The right sciatic nerve was affected in 12 patients. These tumors were large and high grade. A mean of 22 cm of the nerve had to be resected (range, 8-42 cm). Ten patients received preoperative radiotherapy and 16 patients had intraoperative or postoperative radiotherapy. At a mean followup of 35 months (range, 7-97 months), 14 of the 20 patients were alive. Two patients had local recurrences develop (10%), whereas 12 patients had distant metastases. The function of the 10 patients as assessed by the Toronto Extremity Salvage Score averaged 74%. Most patients indicated that walking in the house is not difficult, but walking is compromised as soon as an effort is needed. Four patients walk without a cane, four needed one cane, and two needed two canes. The patients experienced stiffness, a sense of numbness, and premature fatigue. The use of analgesics was infrequent. Generally, patients rated themselves to be mildly to moderately disabled. From this small number of patients, it is shown that a tumor involving the sciatic nerve can be treated by limb-sparing surgery, including complete nerve resection, as an alternative to hip disarticulation or hindquarter amputation because the limb salvage option provides an acceptable functional outcome.

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.

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.

Effects of early postoperative 5-fluorouracil and ageing on the healing capacity of experimental intestinal anastomoses

BACKGROUND

Results from a previous study suggested that advanced age does not affect early repair of experimental intestinal anastomoses. The present study aimed to establish whether anastomotic healing is impaired more easily in old animals by immediate postoperative chemotherapy.

METHODS

Young adult (2-3 months) and old (27-30 months) rats underwent resection and anastomosis of both ileum and colon. Within each age group, subgroups received intraperitoneal saline or 5-fluorouracil in a dose of 15 or 20 mg per kg per day from the day of operation onwards. After 7 days, anastomotic healing was assessed by wound strength and collagen deposition in the wound area.

RESULTS

No differences were found between young and old control groups. The higher dose of fluorouracil induced severe loss of strength with concomitant reduction of wound collagen, which was similar in both age groups (ileum: from 52(13) to 24(8) volume per cent in young animals and from 56(10) to 20(9) volume per cent in old animals; colon: from 58(10) to 37(18) volume per cent in young animals and from 65(5) to 30(17) volume per cent in old animals). The lower dose of fluorouracil induced a significantly greater loss of strength, measured as the bursting pressure, in the old animals (150(49) versus 201(59) mmHg in colon of young rats).

CONCLUSION

In this model early anastomotic repair in older animals proceeds normally under optimal conditions, but it is more easily disturbed in the presence of fluorouracil.