Читать книгу Small Animal Surgical Emergencies - Группа авторов - Страница 183

When removing a discrete foreign body, the enterotomy incision should be made in the normal small intestine immediately distal (aboral) to the foreign body (Figure 5.7a). Incisions made directly over a discrete foreign body are contraindicated due to the impaired perfusion at the site of the foreign body. Incisions made proximal to the foreign body may be associated with a greater risk of spillage of ingesta secondary to the buildup of fluid proximal (orad) to the obstruction. This area of dilation is also associated with a secondary bacterial overgrowth making spillage of ingesta from this area even more concerning. Spillage of ingesta is also limited by using Doyen forceps or an assistant's fingers to atraumatically compress the intestine on either side of the enterotomy site. The length of the enterotomy incision required to remove a discrete foreign body, regardless of the nature of the foreign body, should be only minimally larger than the distance from the mesenteric border to the antimesenteric border as this is the maximum size of an object capable of creating an obstruction (Figure 5.7b). It is important when removing the foreign body to use an instrument to grasp the foreign body, decreasing glove contamination, and to remove that instrument from the sterile area with the foreign body.

As previously mentioned for gastrotomy, contaminated instruments should be replaced with sterile instruments for enterotomy closure. Gloves should also be changed. Following removal of a discrete foreign body, closure is performed using a simple interrupted or simple continuous appositional pattern using monofilament synthetic absorbable material (polydioxanone, polyglyconate, glycomer 631). Incorporation of the submucosal layer is critical for enteric closure, as this is the holding layer of the intestines. In cases of perforation or questionable intestinal viability, a resection and anastomosis may be necessary. Resection and anastomosis requires careful attention when assessing the blood supply to the area to be resected. Only those blood vessels directly supplying the area of resection should be ligated. The vessels should be triple ligated, allowing two ligations to stay in the body and one to stay on the resected intestine to prevent bleeding during resection. Carmalt forceps can be placed on the section of intestine that is being resected to prevent spillage of ingesta, and Doyen forceps or the fingers of an assistant surgeon can be used to atraumatically prevent ingesta spillage from the ends to be anastomosed. The anastomosis can be achieved with suturing in a simple interrupted pattern, simple continuous pattern, or a combination of both patterns using monofilament synthetic absorbable material (polydioxanone, polyglyconate, glycomer 631).

Figure 5.7 (a) and (b) Discrete foreign body lodged within the small intestine of a dog. The incision is made aboral (arrow) to the foreign body. Length of the incision (line B) is equal to the width of the foreign body in the intestine (line A).

As the mesenteric border is typically covered in fat, it is crucial that the first suture is placed at the mesenteric border in order to allow for appropriate visualization of the intestinal wall in that area. Another option for performing an anastomosis is to create a functional end‐to‐end anastomosis using GIA™ and TA™ staplers. Studies comparing dehiscence rates between sutured and stapled anastomoses have shown either no significant difference in dehiscence rates between the two options [60] or decreased risk of dehiscence with the stapled anastomoses [61].

In the ileum, identifying the appropriate location of the enterotomy incision for foreign body removal can be challenging. The standard duodenal or jejunal enterotomy incision is made on the antimesenteric border of the intestine. However, the antimesenteric vessel of the ileum precludes use of this site, and enterotomy incisions must be made between the mesenteric and antimesenteric borders. In cases of perforation or questionable intestinal viability in the region of the ileum, the decision to perform a resection and anastomosis frequently necessitates anastomosis of the distal jejunum or proximal ileum to the proximal colon. Disparity between the luminal diameters of these two segments precludes routine end‐to‐end anastomosis of small intestinal and colonic segments. Incising the small intestine at a greater angle and then correcting the remaining luminal disparity by incising the small intestine longitudinally at the antimesenteric border can address the discrepancy in lumen diameter (Figures 5.8 and 5.9). The combination of these techniques enlarges the opening of the small intestine to equal the size of the colon. Alternatively, the colon can be partially sutured to equal the lumen size of the small intestine.

After enterotomy or resection and anastomosis is completed, a leak test can be performed to evaluate the closure. This can be achieved by compressing the intestine with either Doyen forceps or an assistant surgeon's fingers 5 cm from each end of the enterotomy or anastomosis and using a small gauge needle to inject sterile saline into the intestine until the segment between the Doyens or fingers is taut. The suture line should be evaluated for any fluid leakage. Additional sutures should be placed at any site with fluid leakage. Afterwards, the peritoneal cavity should be lavaged thoroughly with warm sterile saline with the saline removed via suction. Following lavage, an omental wrap or serosal patch may be placed based on surgeon preference.