Valve Formation during Colostomy by Means of Spherical Implants Based on Titanium Nickelide Both Wrapping and Non-Wrapping the Serous-Muscular Layer of the Intestine

Abstract

Imposition of a classic colostomy does not allow to control the passage of intestinal discharge. This shortcoming provides rationale for development of new materials for implants, as well as new techniques for valve formation. The aim of the study is to assess the possibility of using spherical implants based on titanium nickelide both wrapping and non-wrapping the serous-muscular layer of the intestine for valve formation during colostomy.

Materials and methods: Experiments were performed on 45 male Wistar rats with the average body weight of 587±10 g. Depending on the type of surgical intervention, all animals were divided into three groups. In the control group (n=15), a classic end colostomy was formed without spherical implants. In test group 1 (n=15), colostomy was formed using spherical implants made of titanium nickelide with wrapping the serous-muscular layer of the intestine; in test group 2 (n=15), the same procedure was performed without wrapping the serous-muscular layer. To assess the clinical condition of the animals, the authors monitored the body weight dynamics, food and water consumption, signs of discharge from the stoma, and recorded complications. The animals were euthanized on day 7, day 30, and day 60 of the experiment. During necropsy, the condition of the abdominal organs was assessed macroscopically with a special attention to the signs of adhesions. The severity of the inflammatory process in the area of surgical intervention was assessed histologically.

Results: The survival rate in three groups was 100%. In the group with the formation of a colostomy non-wrapping the serous-muscular layer, a good effect of regeneration in the stoma area was shown, the connection of the skin flap and the intestinal wall was complete. Macroscopically, adhesions and inflammatory processes of the peritoneum in the control and two test groups were minimal.

Conclusion: The present study shows the advantage of experimental modeling of colostomy using spherical titanium nickelide implants non-wrapping the serous-muscular layer of the colon compared to classical formation of colostomy. At that, wrapping the serous-muscular layer of the colon using spherical titanium nickelide implants is behind classical formation of a colostomy.

Keywords: colostomy; neosphincter; serous-muscular sphincter; titanium nickelide.

Figure 1.. Scheme of application of spherical implants based on titanium nickelide:

1 — a spherical implant; 2 — the serous-muscular layer of the intestine; (a)–(c) cases of using the spherical implant without wrapping the serous-muscular layer; (d) the case of using a spherical implant with wrapping the serous-muscular layer

Figure 2.. Deformation characteristics of biological tissue (1) and an alloy based on titanium nickelide (2)

Figure 3.. Stages of surgery:

(a) preparation of the surgical site; (b) detachment of the serous-muscular layer of the intestine; (c) wrapping the serous-muscular layer using spherical implants; (d) use of spherical implants without wrapping the serous-muscular layer; (e) wound suturing, final view on the formed colostomy

Figure 4.. Experimental design

Figure 5.. Dynamics of the animal body weight in the study groups (percentage of the body weight before surgery) on days 1, 2, 3, 4, 5, 7, 30, and 60 after surgery (p>0.05)

Figure 6.. Relative incidence of complications associated with the colostomy formation:

(a) abscess of a laparotomy wound; (b) bleeding on day 1 after surgery; (c) evagination of the stoma; (d) peristomal dermatitis; (e) stoma stenosis; (f) postoperative complications

Figure 7.. Day 7 of the experiment:

(a), (b) control group, areas of granulation tissue between the skin flap and the intestinal wall (arrow); availability of productive inflammation (asterisk); hematoxylin and eosin staining; (a) ×40; (b) ×100; (c), (d) test group 1, different angles, areas of granulation tissue between the skin flap and the intestinal wall (arrow); hematoxylin and eosin staining; ×40; (e) test group 2, a fragment of the intestinal wall with a transition to granulation tissue, on the surface of which fibrin with an admixture of neutrophils is seen (arrow); stained with hematoxylin and eosin; ×40

Figure 8.. Day 30 of the experiment:

(a), (b) control group, consistency of colostomy, boundary of skin flap and colon mucosa (arrows); hematoxylin and eosin staining; (a) ×40; (b) ×100; (c), (d) test group, areas of granulation tissue between the skin flap and the intestinal wall (asterisk) with dermal necrosis (arrow); stained with hematoxylin and eosin; (c) ×40; (d) ×100; (e), (f) test group 2; stained with hematoxylin and eosin; (e) ×40; (f) ×100

Figure 9.. Day 60 of the experiment:

(a), (b) control group, consistency of colostomy; edge of the skin flap and the colon mucous membrane stained with hematoxylin and eosin; (a) ×40; (b) ×100; (c), (d) test group 1, anastomosis zone, different angles; hematoxylin and eosin staining; ×40; (e), (f) test group 2, consistency anastomotic zone; hematoxylin and eosin staining; (e) ×40; (f) ×100

Figure 10.. Relative frequency of the inflammatory response intensity assessment:

(a) on day 7; (b) on day 30; (c) on day 60

Figure 11.. Macrostructure of the formed tissue in experimental specimens implanted with (a), (b) and without wrapping the serous-muscular layer (c), (d)

Covering with its own connective tissue (arrows)