Small Animal Surgical Emergencies. Группа авторов

mucosa and submucosa followed by an inverting pattern in the seromuscular layer. Monofilament absorbable suture materials such as polydioxanone, polyglyconate, and glycomer 631 are most commonly used.

Figure 5.4 (a) Foreign body within the stomach. The stomach has been packed off using laparotomy sponges from the remainder of the abdomen and a foreign body is palpable within the stomach. (b) Stay sutures are utilized to prevent spillage of gastric content. Length of incision is based on the size of the foreign body being removed.

In the case of a linear foreign body, the anchored foreign material must be released from its location before attempts to remove the foreign body are made. In cats, the most common anchor site is under the tongue (Figure 5.5), while in dogs, it is at the pylorus [11]. If the material is anchored at the pylorus, a gastric incision may be made in the pyloric antrum in order to better facilitate release of the material as it extends into the duodenum. In some cases, it may be possible through combined gentle external manipulation of the duodenum and gentle traction on material in the stomach, to manipulate the material back into the stomach, forgoing the need for additional surgical incisions in the GI tract. It is ideal if the gastrotomy incision does not involve the pylorus, as outflow may be reduced by the presence of inversion or swelling at the site of closure. Contaminated instruments should be replaced with sterile instruments in the surgical field to close the gastric incision. The surgeon should also replace their gloves with a sterile pair. Following gastrotomy closure, the abdomen should be lavaged and suctioned thoroughly followed by standard closure of the abdominal cavity.

      Small Intestine

      Anatomy

Even though many discrete small intestinal foreign bodies are easily removed, the nature of the foreign body and the location of the obstruction can present a surgical challenge. Removal of foreign bodies within the duodenum demands knowledge of the regional anatomy including the entrance of normal anatomic structures, such as the bile and pancreatic ducts, into the proximal duodenum (Figure 5.6). The intimate association of the duodenal and pancreatic blood supply is also important to consider when incising the duodenum. In addition, the distal duodenum turns at a sharp angle at the caudal duodenal flexure. This bend is created by the duodenocolic ligament, which tethers the distal duodenum to the colon. Careful excision of this ligament allows this area of the small intestine to be exteriorized and more adequately visualized during foreign body removal.

Figure 5.5 A string foreign body under the tongue of a cat.

Minimally invasive options for exploratory laparoscopy in patients with GI obstruction recently have been evaluated. One study performed laparoscopy followed by open laparotomy in dogs to assess if laparoscopy was feasible in cases of suspected GI obstruction. The results indicated that laparoscopy was equivalent to open laparotomy in regard to ability to diagnose an obstruction, with laparoscopy having a significantly smaller incision length; however, the time for laparoscopic explore was longer than for open abdominal explore. Additionally, complete laparoscopic explore was not possible in 3 of 16 cases, and conversion to a much longer incision length would have been needed to treat the obstruction in 4 of 13 cases where laparoscopic explore was feasible [58]. In another study, dogs undergoing single incision laparoscopic‐assisted intestinal surgery (SILAIS) were retrospectively compared with dogs undergoing open laparotomy for simple intestinal foreign body removal. Three of thirteen dogs in the SILAIS group required conversion to open laparotomy, but no postoperative complications occurred in either group. No significant differences were found in recovery time, surgical time, or duration of hospitalization between the two groups [59]. The results of these studies show promise for minimally invasive options for use in simple GI obstructions; however, more research is needed to determine if these options provide a benefit to the patient over traditional open procedures for intestinal foreign body cases.

Figure 5.6 Anatomy of the stomach and duodenum including the entrance of normal anatomic structures, such as the bile and pancreatic ducts, into the proximal duodenum.

      Discrete Foreign Body

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