Influence of intraperitoneal 5-fluorouracil plus folinic acid on the healing of colonic anastomoses in rats

We studied the effects of intraperitoneal 5-fluorouracil (5-FU) administration with or without the addition of folinic acid (FA) on the healing of colonic anastomoses in rats immediately after surgery. Sixty-three male Wistar rats were subjected to colonic anastomosis. During surgery, the rats were randomized into one of three groups. Therapy was administered as an intraoperative intraperitoneal injection which was repeated once daily for the first 2 postoperative days. A 0.9% NaCl solution was administered to the rats in the control group. In group 2, we injected 5-FU (20 mg/kg/day) and in group 3 5-FU (20 mg/kg/day) plus FA (2 mg/kg/day). The rats were sacrificed on postoperative days 3, 5 or 8. Rupture of the anastomosis was significantly higher in the rats of groups 2 and 3, compared with the control group (p < 0.05). There were, however, no differences between groups 2 and 3. Formation of adhesions and abscesses was more common in groups 2 and 3 than in the control group for all study days. A significant difference in the anastomotic bursting pressure was measured for the control group in comparison to groups 2 and 3 on days 5 and 8 (p < 0.05). Histologic evaluation also showed a more profound inflammatory reaction and delayed healing of the anastomoses in groups 2 and 3, compared to the control group. Therefore, the perioperative intraperitoneal administration of 5-FU can inhibit the healing of colonic anastomoses in rats. The addition of an intraperitoneal injection of FA does not aggravate this negative effect.     

Intraoperative bowel irrigation improves anastomotic collagen metabolism in the left-sided colonic obstruction but not covering colostomy

This study investigated the effects of intraoperative colonic irrigation and proximal diverting end colostomy after segmental bowel resection in experimental left-colonic obstruction on anastomotic healing. Simple obstruction of descending colon was performed in male Sprague-Dawley rats. After 24 h we performed segmental colonic resection and anastomosis in the control group (n = 15); resection, anastomosis, and covering colostomy in the colostomy group (n = 14); resection and anastomosis after antegrade colonic lavage through cecum by using isotonic saline solution in the irrigation group (n = 13). In rats that were killed 7 days later anastomotic dehiscence and bursting pressure and tissue hydroxyproline concentration at the anastomosis were measured. No significant differences were observed between groups in terms of anastomotic dehiscence, bursting site, or pressure. The hydroxyproline concentration was significantly higher in the irrigation group than the control group (P = 0.025) and the colostomy group (P = 0.029), but no difference was noted between the control group and the colostomy group. These findings suggest that intraoperative antegrade colonic irrigation in the acute left-sided colonic obstruction positively affects collagen metabolism at the anastomotic site; if the anastomosis is performed without bowel cleansing, covering colostomy does not improve collagen metabolism.     

Effect of growth hormone treatment on the healing of left colonic anastomoses in protein-malnourished rats

BACKGROUND: Malnutrition is known to affect wound healing but it is not known with certainty whether or not postoperative hyperalimentation can reverse this defect. The present study was designed to examine the effects of recombinant human growth hormone (hGH) on left colonic anastomoses in malnourished rats. METHODS: Experimental animals were allocated randomly into four groups. In groups 1 and 2 animals were fed with normal diet for 10 days before surgery. In groups 3 and 4 animals were fed with a low-protein diet. Left colonic anastomoses were performed in all animals. Following surgery, rats in groups 1 and 3 received hGH whereas rats in groups 2 and 4 were injected with saline as control. Bursting pressure and hydroxyproline levels on day 4 after operation were used to determine anastomotic healing. Results: Bursting pressure was lower in the malnourished rats than those fed with normal diet (P< 0.05). Bursting pressure was higher in normally fed rats which were given hGH. No significant differences could be noted between malnourished control rats and those receiving hGH. CONCLUSION: These results suggest that hGH strengthened the left colonic anastomoses in rats fed a normal diet, but could not reverse the negative effects of malnutrition on colonic anastomoses.     

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.     

Effect of fibrin sealant on the integrity of colonic anastomoses in rats with faecal peritonitis

OBJECTIVE: To assess the influence of fibrin adhesive on the healing of colonic anastomoses in rats with and without faecal peritonitis. DESIGN: Controlled study. SETTING: Laboratory for experimental surgery, Erasmus University Rotterdam, The Netherlands. MATERIAL: 120 male Wag/Rij rats. INTERVENTIONS: All rats had a single layer end-to-end anastomosis fashioned with 7/0 polypropylene. Faecal peritonitis was then induced in half of the rats by placement of 200 mg powdered autoclaved rat faeces in the peritoneal cavity near the anastomosis. Rats were allocated to one of four groups (n = 30 in each): 1--control; 2--additional sealing with fibrin glue; 3--peritonitis alone; and 4--peritonitis with fibrin glue. MAIN OUTCOME MEASURES: Body weight, adhesion formation, anastomotic bursting pressure and collagen concentration around the anastomosis on days 2, 4, and 7 in 10 rats from each group. RESULTS: 11 rats died of peritonitis before the experiment was completed. Peritonitis caused increased formation of adhesions and abscesses, with or without fibrin sealant. Bursting pressure at the anastomosis was significantly reduced in peritonitis compared with controls on days 4 and 7, and this was not prevented by fibrin. Sealing of anastomoses resulted in lower bursting pressures on day 4 in control animals. Collagen concentration was significantly reduced in peritonitis with or without fibrin sealant on days 4 and 7, and after fibrin sealing of control anastomoses. CONCLUSION: Faecal peritonitis reduced mechanical strength and collagen concentration of colonic anastomoses, and this was not prevented by additional sealing of the anastomosis with fibrin sealant.     

Intra-operative irradiation prolongs the presence of matrix metalloproteinase activity in large bowel anastomoses of the rat

There exists a growing interest in intra-operative radiation therapy as a treatment modality for large bowel cancer. In a previous experimental study we showed that high-dose intra-operative irradiation delays the healing of colonic anastomoses. However, the contribution of proteases is unknown. In the present study, the gelatinolytic and collagenolytic activity in the healing anastomoses is investigated. After a resection of a 1-cm length of colon (uninjured colon), the rats were irradiated with a single dose of 25 Gy, either to the proximal limb, referred to as the proximal group, or to both proximal and distal limbs of the bowel, referred to as the combined group, before anastomotic construction. Both groups were compared to a control group with anastomoses which were sham-irradiated. The animals were killed 1, 3 or 7 days after operation. The gelatinolytic activity in uninjured and anastomotic tissue was quantified by gelatin zymography and the collagenolytic activity by an assay using a fibrillar rat collagen substrate. Compared with resected uninjured colon, most of the gelatinolytic activities were markedly increased in anastomotic tissue of all groups during the first postoperative week, and new additional activities were detected. The additional metalloproteinases (the 95-kDa family) of both irradiated groups were significantly elevated compared to the anastomoses of the sham-irradiated control group at 7 days after operation. In anastomotic tissue of all groups, the collagenolytic activity of the tissue was also significantly increased at 1 and 3 days after construction with respect to the resected, uninjured colon. After 7 days this effect had disappeared for the sham-irradiated anastomoses, but the activity in the anastomoses in both the proximal and combined groups remained significantly elevated. The findings provide evidence that intra-operative irradiation prolongs the presence of elevated gelatinolytic and collagenolytic activities in colon anastomoses. It may contribute to a reduced or delayed accumulation of collagen and other matrix proteins that supply anastomotic strength.     

Jejunoileal atresia: a 27-year experience

PURPOSE: In this study, the authors review cases of jejunoileal atresia (JIA) to evaluate their surgical treatment strategy. METHODS: Eighty-eight neonates who underwent surgical repair for JIA were divided into four groups for the type of lesion: group 1, membranous (n = 23), group II, interrupted (n = 49), group III, multiple (n = 9), and group IV, apple-peel (n = 7). Group I patients were treated with membranectomy or bowel resection and anastomosis, group II with resection of the dilated bowel and one anastomosis, group III with two to six multiple anastomoses to preserve bowel length, and group IV with minimal bowel resection and bowel anastomosis. During surgery a uniform protocol was used to minimize bowel resection and to perform an end-to-end single layer anastomosis using either Halsted horizontal mattress or conventional interrupted sutures. Mortality, morbidity, days for functional recovery, and central venous nutrition (CVN) were included in the review. RESULTS: Of 88 patients, three died of causes unrelated to operation for JIA. Nine patients underwent an additional laparotomy for leakage (n = 4) and obstruction (n = 5). Oral feeding was allowed on day 5.4+/-4.3 and full caloric intake via the enteric route on day 12.5+/-10.0. Twenty-one patients required CVN for 32.4+/-19.1 days. None required a long-term treatment for the short bowel syndrome. CONCLUSION: This study concludes that efforts to preserve bowel length are laudable to avoid the short bowel syndrome and that an end-to-end single layer anastomosis contributes to early recovery of bowel function.     

Second generation hepatitis C virus antibody-positive rate in children: investigation of the route of hepatitis C virus infection in children with no history of transfusion

BACKGROUND: Proponents of laparoscopic colectomy claim a more rapid return of gastrointestinal function, but objective data supporting this contention are lacking. Our aim was to compare the duration of delay in gastrointestinal transit after total laparoscopic, laparoscopic-assisted, and open colonic resection. METHODS: Thirty-nine female dogs were assigned to three groups: group 1, laparoscopic colectomy; group 2, laparoscopic-assisted colectomy; and group 3, open colectomy. Transit studies were performed before operation and on days 1, 2, 3, and 5 after a mid-descending colectomy with end-to-end anastomosis. Gastric emptying of liquids and small bowel transit of liquids were determined by means of radionuclide techniques. Gastric emptying of solids and colonic transit were measured by following transit of radiopaque spheres instilled into the stomach and proximal colon, respectively. RESULTS: With each dog as its own control, gastric emptying returned to preoperative values by 2 days in group 1, 3 days in group 2, and 5 days in group 3. Small bowel transit returned to preoperative values on day 3 for groups 1 and 2 and on day 5 for group 3. Gastric emptying of solids and colonic transit returned to preoperative values on day 3 for group 1 and on day 5 for groups 2 and 3. CONCLUSIONS: These observations show that laparoscopic resection techniques in this canine model resulted in a more rapid return to normal gastrointestinal transit compared with open colectomy.     

Decrease in contents of pancreatic carboxyl ester lipase, phospholipase A2, and lingual lipase in rats with streptozotocin-induced diabetes

Fibrin glue has been used as a protective seal in normal and high-risk anastomoses to prevent leakage. The influence of fibrin adhesive on the healing colonic anastomosis in a control and high-risk model was tested. Resection and anastomosis of the left colon was performed in rats. In group Ia an end-to-end anastomosis was constructed with 12 7-O polypropylene sutures; in group Ib the anastomosis was sealed with fibrin adhesive. In group II an incomplete anastomosis was constructed with only 4 sutures at 90 degrees, therefore potentially leaking. In group IIb additional sealing with fibrin glue was performed. On Days 2, 4, and 7 body weight, adhesion formation, anastomotic bursting pressure, and collagen concentration were measured. The results showed increased adhesion formation after fibrin sealing. The anastomotic bursting pressure of incomplete anastomoses showed a significant increase after sealing on Day 2 only; on Day 4 and 7 no differences were found. Sealing of control anastomoses caused lower bursting pressures on Day 4. Collagen concentration is significantly reduced after fibrin sealing of normal anastomoses. We conclude that fibrin sealing of control anastomoses inhibits wound healing. Incomplete anastomoses are temporarily protected by fibrin glue sealing. Finally, fibrin sealing of the colon wound does not prevent adhesion formation.     

Secure anastomoses of the large intestine (especially with transanal drainage

The results of colonic resections were investigated in 356 patients in a retrospective analysis. Special attention was directed to the effectiveness of a transrectal tube, leading to decompression of the anastomosis for the first five days. Under elective conditions, the overall complication-rate was 12.7%. In emergency cases, these complications were 51.5% (one third of these cases had a decompression-tube). The clinical relevant leakage-rate under elective conditions ranged to 1.7%. Postoperative mortality related to surgical complications turned out to be 1.5% under elective conditions. The emergency operations had a high mortality which ranged to approximately 15.2%. No patient with leakage of a colorectal anastomosis died when the transrectal decompression-tube was applied. Such a safety in anastomotic healing of colon and rectum anastomoses can otherwise only be achieved by using the protection of a diverting colostomy or ileostomy. The use of the transrectal decompression-tube also avoids stomal complications and the second operation. There is no indication for the decompression-tube in emergency operations with purulent or faecal peritonitis. In these cases a fundamentally different treatment is mandatory.     

Usefulness of ultrasound-guided prostate biopsy in the diagnosis and treatment of localized prostate cancer

OBJECTIVE: To evaluate the safety and efficacy of stapled anastomosis in left sided colorectal reconstructions. DESIGN: Prospective study. SETTING: District hospital, UK. SUBJECTS: 218 Consecutive patients who underwent elective colorectal reconstructions with stapled anastomoses between July 1980 and July 1994. INTERVENTIONS: 154 Anterior resections of the rectum using single or double stapled anastomoses, 37 rejoining after Hartmann's operations, and 28 restorative proctocolectomies with formation of J pouch ileoanal anastomoses. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: There were 5/154 clinical anastomotic leaks after anterior resection of the rectum and 1/28 after stapled J pouch ileoanal anastomoses. There were no leaks after rejoining of Hartmann's. The overall clinical leak rate was therefore 3%. 11/154 tumours recurred locally after anterior resection of the rectum (7%) during a mean follow up of 18 months, and 8 (73%) developed within 2 years of operation. All but one recurrence developed after single stapled anastomosis. Dukes' staging remains the most reliable prognostic indicator of the local recurrence of the tumour. There were five postoperative deaths after anterior resection but none after Hartmann's procedure or J pouch ileoanal anastomosis, giving an overall postoperative mortality of 2.3%. CONCLUSION: The use of stapling instruments in left sided colorectal anastomosis is safe and technically easy, with a low clinical anastomotic leak rate and an acceptable rate of local recurrence after anterior resection of the rectum.     

Healing of colonic ischemic anastomoses in the rat: role of superoxide radicals

PURPOSE: The aim of this study was to evaluate the role of superoxide radicals in the healing of ischemic colonic anastomoses in the rat. METHODS: Adult male Wistar rats were used in a factorial design with two factors (normal or ischemic colonic anastomoses) each having two levels (treatment with saline or allopurinol). Colonic anastomoses were performed either in normal or previously devascularized colons (ischemic anastomoses) at identical locations, using the same technique. On the fourth postoperative day, animals were killed, and specimens were taken for determinations. RESULTS: Ischemic anastomoses displayed significant increases in superoxide radical (assayed as superoxide anion), superoxide dismutase, and glutathione peroxidase concentrations. Bursting strength and hydroxyproline levels were also significantly lower in these anastomoses. Allopurinol administration elicited a significant decrease in superoxide anions and raised both bursting strength and hydroxyproline levels only in ischemic anastomoses. CONCLUSIONS: Superoxide radicals are involved in the delay in healing of ischemic anastomoses. Allopurinol lowers superoxide anion production and has beneficial effects on the cicatrization of ischemic anastomoses.     

Effects of hyaluronic acid/carboxymethylcellulose gel on bowel anastomoses in the New Zealand white rabbit

Intra-abdominal adhesions form in more than 90% of patients undergoing major abdominal surgery and can lead to significant complications. Application of a bioresorbable gel consisting of chemically modified hyaluronic acid (HA) and carboxymethylcellulose (CMC) has shown promise as a means of preventing intra-abdominal adhesions, but there have been concerns that the presence of the gel might interfere with the integrity and healing of bowel anastomoses. We tested the effects of HA/CMC gel on adhesion formation and anastomotic healing in 60 New Zealand white rabbits after transection and complete (100%) or incomplete (90%) anastomosis of the ileum. Half of the animals underwent application of HA/CMC gel and half served as control subjects. Animals were killed at 4, 7, or 14 days after surgery. Anastomotic adhesions were scored in a blinded fashion. Integrity of the anastomosis was tested by measuring bursting pressure at the anastomotic site and in an adjacent section of intact bowel. With complete anastomosis, HA/CMC gel significantly reduced adhesion formation at 7 and 14 days after surgery (P<0.05), but gel application did not inhibit adhesion formation when the anastomosis was incomplete. Anastomosed segments of bowel burst at a lower pressure than intact bowel 4 days after surgery, but bursting pressures were normal at 7 and 14 days. Burst pressures of anastomoses receiving an application of HA/CMC gel were nearly identical to control anastomoses at all three time points. HA/CMC gel did not interfere with the normal healing process of bowel anastomoses. Furthermore, HA/CMC gel decreased adhesion formation after complete anastomoses, yet it did not affect adhesion formation in the presence of anastomotic disruption.     

Intracorporeal colorectal anastomosis following laparoscopic left colon resection

BACKGROUND: The aim of this study was to assess the impact of an intracorporeal double-stapled colorectal anastomosis upon the outcome of laparoscopic left colon resection. METHODS: Fifty-four selected patients underwent elective laparoscopic left colon resection for benign disease. Once resection was completed, a 33-mm suprapubic port allowed insertion of the anvil of a circular stapler into the colon, which was closed by a handsewn purse-string suture using the T-needle technique. The circular stapler was passed transanally to perform a double-stapled anastomosis. Specimens were delivered in a plastic bag via the suprapubic port. RESULTS: There were no deaths. Minor intraoperative and postoperative complications occurred in 3.7% and 9.2% of the patients, respectively. Median operating time was 125 min (range 80-210 min). Complete proximal and distal doughnuts were obtained in all patients and anastomoses were all methylene blue tight. Median hospital stay was 4 (range 3-7) days. CONCLUSIONS: Fashioning double-stapled colorectal anastomoses intracorporeally is feasable and safe.     

Primary resection with antegrade colonic irrigation and peritoneal lavage versus subtotal colectomy in the management of obstructed left colon cancer

Between 1980 and 1996 122 patients with acutely obstructed resectable carcinomas of the colon and rectum were treated in our hospital. Ninety-four has undergone one stage operation of immediate resection and primary anastomosis without proximal colostomy. Intraoperative colonic irrigation was performed in 34 patients, subtotal/total colectomy in 30 patients, right hemicolectomy in 30 patients. There were 2.3 and 1 operative deaths, respectively. The average hospital stay for the survivors was 19.8 days in the primary resection and anastomosis group, and 41.0 days in staged operation group. Concerning the possibility of multiple lesions the authors recommend subtotal/total colectomy except for tumours localized in the sigma where they apply total colectomy only when the proximal part of the colon is necrotized or filled with solid stool.     

Model of implantation of tumor cells simulating recurrence in colonic anastomosis in mice

PURPOSE: Local recurrence after colorectal cancer surgery is usually perianastomotic. An experiment was designed to investigate whether free intraluminal cells can penetrate through a colonic anastomosis and thereby cause local recurrence. METHODS: BALB/c and C57/BL mice underwent ascending colotomy followed by watertight anastomosis. Thereafter, CT-26 murine colon carcinoma cells were injected into the cecal lumen 2 cm proximal to the anastomosis of syngeneic BALB/c mice, whereas B-16 murine melanoma cells were injected in the same fashion into C57/BL mice. Control animals without anastomosis received similar injections. Animals were killed 24 hours, 72 hours, and 30 days after surgery and were checked for tumorigenesis. RESULTS: Results of peritoneal fluid cytology were negative after 24 hours, whereas after 72 hours cancer cells were identified in the peritoneal fluid of 80 percent of mice with colotomy and anastomosis compared with 20 percent of control mice. Thirty days after surgery, 11.1 percent of the control BALB/c mice developed pericecal tumor growth, similar to the overall rate of murine melanoma in C57/BL. In mice with anastomoses, perianastomotic tumor growth was observed in 47.5 percent of BALB/c mice (P < 0.001) and was correlated with the number of injected cells. Tumor growth reached approximately 75 percent tumor take with high cell densities, whereas in C57/BL mice no difference was found between the experimental and control groups. CONCLUSIONS: The findings suggest that free intraluminal cancer cells of colonic origin may penetrate through watertight anastomoses and implant on the anastomotic or peritoneal surface and initiate tumor growth. This anastomotic penetration is cell-mass dependent. The reported experimental model is simple, reproducible, and advantageous for studies of colonic anastomosis.     

The prevalence and severity of cancer pain: a study of newly-diagnosed cancer patients in Taiwan

In current clinical practice the "double-stapling technique" is the standard for reanastomosis following minimally invasive sigmoid resection. In the present study, we compared the TESA technique (transient endoluminally stented anastomosis) with conventional stapled anastomosis and evaluated the effect of remnant foreign material on follow-up examination with endosonography. Laparoscopic sigmoid resection was performed in 12 pigs (mean weight 63+/-5.9 kg). Animals were randomly divided into two groups: In Group A, reanastomosis was performed following a standard technique using a 29-mm circular stapler. In Group B, the TESA technique using a resorbable radiopaque stent of polyglycolic acid was applied. The anastomosis was examined by plain x-ray on days 1, 7, and 14, and by contrast enema on day 42, respectively. Endosonography, macroscopic inspection, and histological evaluation of the anastomosis were performed on day 42. All anastomoses in group A were patent. In one animal in Group B stent displacement with subsequent leak of the anastomosis was observed. Circumferential length of the anastomosis on day 42 did not differ between the groups (Group A: 8.00+/-0.45 cm vs. Group B: 7.8+/-2.0 cm, p = 0.82). The duration of the operation was 130+/-27 minutes in Group A and 100+/-18 minutes in Group B (p = 0.06). Weight gain was equal: Group A: 24+/-9.6 kg vs. Group B: 24+/-5.0 kg, p = 0.74. Endosonography on day 42 postoperatively in the area of the anastomosis in group A was impaired due to metallic staples. TESA is a competitive method for reanastomosis following laparoscopic sigmoid resection. In contrast to the conventional technique, the anastomosis is free of foreign material 1 month after the operation, which facilitates follow-up examinations with endosonography as well as other imaging diagnostics.     

Glutamine dipeptide attenuate mucosal atrophic changes and preservation of gut barrier function following 5-FU intervention

Traditional parenteral nutrition (PN) and chemotherapy may lead to changes mucosal morphology and gut barrier function. To investigate the effects of alanyl-glutamine on intestinal mucosal morphology and gut barrier function in PN-fed rats challenged with 5-FU male Wistar rats were central catheterized and randomily divided into two groups: PN group (n = 10) that received traditional parenteral nutrition solution only, and Ala-Gln group (n = 10) that received glutamine dipeptide enriched nutritional solution (3% Ala-Gln). The rats were maintained on their respective diets for 7 days. 5-FU (75 mg/kg) was injected intraperitoneally at 8 am on day 4. All rats were gavaged with lactulose (100 mg) and mannitol (50 mg) in 2ml before and three days after administration of 5-FU. Ala-Gln group maintained serum glutamine concentration, intestinal mucosal morphology. While bacterial translocation rates in ala-Gln group was 30%, in PN group was 90% (P < 0.05). Similar intestinal permeability was observed on day 3 in both groups. The control group had a significantly increased intestinal permeability on day 7 (P < 0.05), while Ala-Gln group maintained the intestinal permeability. It was suggested that alanyl-glutamine maintained intestinal morphology and gut barrier function in PN-fed rats challenged with 5-FU.     

The effect of recombinant growth hormone on the strength of ileal anastomoses in a rat model

OBJECTIVE: In gynecologic surgery, the ileum is the primary site of bowel injury. Recombinant growth hormone (rGH) has been shown to improve the strength of colonic anastomoses in experimental models. The purpose of this study is to evaluate the effect of rGH on small bowel anastomoses, specifically in the ileum. METHODS: Twenty large female rats underwent segmental ileal resections and end-to-end ileoileostomies. The rats were randomized to be treated for 7 postoperative days with either rGH (2.0 mg/kg/day) or placebo starting on the day of surgery. On the seventh postoperative day, a segment of ileum surrounding the anastomosis was resected. The anastomoses were tested for breaking strength on a tensiometer and for tissue concentrations of hydroxyproline. RESULTS: The ileal anastomotic breaking strength in the rGH group was 163.5 +/- 6.0 g (mean +/- standard error). In the placebo group, the breaking strength of ileal anastomoses was 125.0 +/- 3.0 g (P < .001). No significant difference was demonstrated with respect to the hydroxyproline concentration between the rGH group (15.2 +/- 2.0 micrograms/mg) and the placebo group (14.6 +/- 1.0 micrograms/mg). CONCLUSION: In an animal model, a 31% increase in ileal anastomotic breaking strength was induced by rGH administration. With further research this may translate into decreases in the surgical complications that occur in ileal anastomoses. Furthermore, these serve as preliminary data to a study that evaluates the effect of rGH on ileal anastomoses in radiation-injured bowel.     

The leaching of nickel from new and used metal spectacle frames

Hyperthermia is a promising method for increasing the efficacy of radiation therapy of colorectal cancer. To study the histological aspects of healing of an anastomosis in the colon, after combined preoperative (sham) irradiation and (sham) hyperthermia treatment, 48 male Wistar rats were divided randomly into four groups. In each animal, a segment of the colon was treated successively by (sham) irradiation (single dose of 25 Gy X rays) and/or (sham) hyperthermia (44 degrees C, 30 min). After 5 days, a resection of the colon was performed by construction of an anastomosis: The distal limb consisted of (sham-) irradiated and/or (sham-) hyperthermia-treated bowel. Rats were killed 3 or 7 days after the surgical procedure. Evaluation of healing of the anastomosis was made by: (1) histological analysis of sections stained with hematoxylin and eosin, (2) semiquantitative measurement of collagen in the area of the anastomosis and (3) semiquantitative analysis of the number of macrophages by immunocytochemistry. Healing of the anastomoses in animals receiving irradiation or hyperthermia alone and in control animals was relatively uneventful. There were no differences between groups in formation of collagen or infiltration by macrophages in the area of the anastomosis. Animals treated with both radiation and hyperthermia showed marked necrosis, infiltration by polymorphonuclear leukocytes and rupture of the anastomosis. It is concluded that preoperative irradiation with a single dose of 25 Gy in combination with local hyperthermia at 44 degrees C for 30 min leads to disturbed repair of anastomoses.