A circulatory collagenase inhibitor

[Determination of fibrin glue with antibiotics on collagen production in colon anastomosis]

BACKGROUND/AIM

Fibrin glue is used as a matrix for local application of antibiotics. The aim of this study was to determine whether application of fibrin glue in combination with antibiotics can strengthen collagen production, prevent dehiscence of colon anastomoses due to infection, and reduce frequency of mortality and morbidity comparing to the control group and the group with fibrin glue application.

METHODS

The adult male Wistar rats divided into three groups were used in the experiment. The group 1 was the control one (after partial colon resection, colonic anastomoses performed were not treated), while to the group 2 and the group 3 were applied fibrin glue and fibrin glue with antibiotics (clindamycin and ceftriaxon) on the site of anastomoses, respectively. Quality of colonic anastomoses were estimated by means of determination of collagen (L-hydroxyproline) amount in the collon wall with anastomoses and histological analysis of this colon segment using light and electronic microscope on the days 5, 7 and 13 postoperatively.

RESULTS

The highest morbidity rate was registered in the group 1 (30%), then in the group 2 (13.3%) and the lowest one in the group 3 (3.33%; p < 0.05 vs group 1). Mortality rate was significantly higher in the group 1 than in the group 3 (20% and 0%, respectively; p < 0.05). In the postoperative course, the highest concentrations of collagen in the colon wall on the site of anastomoses, which was confirmed by both light and electronic microscopy, were found in the group 3.

CONCLUSION

The application of fibrin glue with antibiotics on colon anastomoses reduces the number of dehiscence, provides good mechanical protection and shorten the time of anastomoses healing.

Endoluminal prosthesis in protecting high-risk colonic anastomosis: an experimental study

An experimental study was carried out to evaluate the protective role of an endoluminal prosthesis on high risk colo-colonic anastomoses. One hundred and fifty rats were divided into two groups: Group E with endoluminal latex prosthesis and Group C without. Bursting pressure and collagen concentration in the perianastomotic tissue were tested, respectively, on the 4th, 7th and 12th, and 4th, 7th, 12th, 18th and 38th postoperative days. Bursting pressure was significantly higher in Group E on the 4th postoperative day. There was no significant difference in the anastomotic collagen concentration between the two groups. The presence of the prosthesis did not produce any macroscopic or microscopic evidence of impaired healing or stricture at the suture line. Death due to anastomotic dehiscence occurred in 11/75 (15%) in Group C and in 1/75 (1.3%) in Group E (p less than 0.01). Endoluminal prosthesis appears to have a protective effect on anastomotic healing. The mechanism is probably due to mechanical protection and not to differences in collegen concentration.

The place of intraoperative antegrade colonic irrigation in emergency left-sided colonic surgery

The healing of colonic or colorectal anastomoses depends, at least partially, on the volume of fecal residue. Intraoperative antegrade colonic irrigation enables the surgeon to prepare the colon adequately at the time of surgery and to perform safely an immediate resection and primary anastomosis in obstructive lesions of the left colon. Its indications have been extended to other left-sided colonic emergencies, especially perforation and hemorrhage. The technique is described in this study and its value is assessed in the light of available experimental and clinical evidence.

Colorectal anastomotic healing and intracolonic bypass procedure

Intestinal anastomoses continue to be complicated by leakages even in the best of hands despite the development of new surgical techniques, suture materials, devices, and stapling instruments. One may explain such persistence of anastomotic leakage on the basis of the dynamic effect that multiple factors have on the healing of an anastomosis. Awareness of these factors and proper precautions by the surgeon can make a high-risk anastomosis less prone to leakage. The intracolonic bypass procedure is an alternative to a temporary colostomy. It does not prevent an anastomotic dehiscence but can prevent anastomotic leakage with its associated complications in those situations where dehiscence is most likely to occur.

Intestinal suturing. Review of the experimental foundations for traditional doctrines

The doctrines of intestinal suturing have been handed down from the 19th century. It has been widely accepted that intestinal wounds heal most reliably when an inverting suture line is constructed. The serosal surfaces of the bowel should be apposed by sutures, anchored in the submucosa, forming an inverting suture line. The wound should be kept free of hematoma, necrotic tissue, or infection. Intestinal wounds heal with a pattern similar to that of wounds in other tissues. During the lag period of repair, the wound is cleansed of debris. Excessive tissue injury, foreign body, or infection incite inflammation, prolonging this period of wound healing. Cellular elements proliferate during the phase of fibroplasia. Collagen within the wound assumes its mature form only during the prolonged phase of maturation. The return of wound integrity can be quantified by measuring its tensile strength, bursting strength, or collagen content. Such measurements have shown that, during the lag period, sutures provide almost the entire strength of the wound. During the phase of fibroplasia, new collagen adds to the suture line integrity. The contribution of new collagen to wound strength soon overtakes that of sutures. It is only during the first week of wound healing, the lag period, that surgical technique plays a significant role in ensuring intestinal wound integrity. Surgical techniques developed during the 19th century provide secure closure of intestinal wounds during the lag period of wound healing. After the onset of the period of fibroplasia, newly formed collagen replaces sutures in ensuring wound integrity.

The effect of faecal loading on colonic anastomotic healing

The effect of faecal loading of the colon on the healing of rat colonic anastomoses has been investigated in a prospective randomized and controlled study. Anastomotic dehiscence occurred significantly more often when the bowel was loaded with faeces at the time of operation than when it was empty. Suture line cultures bore no relationship to the outcome of the anastomosis. This result emphasizes the importance of an empty colon as a contributory factor in successful colonic healing in the rat.

The effect of uraemia upon wound healing: an experimental study

Acute uraemia was induced in rats by performing a 70 per cent nephrectomy. Uraemia was shown to delay the healing of intestinal anastomoses and abdominal wounds in rats as judged by bursting strength tests. Cellular proliferation was depressed at wound edges but there was no reduction in the total amount of hydroxyproline present in the wounds. Fibroblast growth in tissue culture was affected by the addition both of uraemic plasma and of urea solution to the culture medium. The possible causes of these effects are discussed.

[Bursting pressure of colon in the rats and proteinase inhibition (author's transl)]

In the early postoperative period (third postoperative day) the colonic enterotomies show 45 per cent higher bursting pressure following administration of Aprotinin than the control group (p less than 0,02). On the fifth postoperative day no difference was noted between both groups. The interpretation of the results is difficult because specific parameters such as collagen content and collagenase activity were not determinated. The relationship between colonic anastomotic breakdown and collagenase and therefore the question of collagenase inhibition have to be discussed. It is suggested that activation of procollagenase is prevented because trypsin and kallikrein are inhibited by Aprotinin.

Collagenase activity in the gastro-intestinal tract

An experimental study in rabbits demonstrates that a significant postoperative decrease in bursting wall pressure is associated with a similar reduction in the colonic collagen from around the anastomosis.

Mature collagen is broken down by the action of specific enzyme collagenase. This has been estimated by a tissue-culture method and is produced by viable explants of mucosa. There is a significant increase in the amount of this enzyme produced post-operatively and it is suggested that this is responsible for the decrease in collagen and weakness of the colon.

An increased amount of enzyme is produced by explants from the colon than from those of other parts of the gastro-intestinal tract. This is regarded as an important reason for the high incidence of colonic and rectal anastomotic breakdown compared with breakdown of anastomoses in other parts of the gastro-intestinal tract.

Following colonic anastomosis there is increased collagenase production not only locally but throughout the gastro-intestinal tract, suggesting that wound healing is not only under local control.