6.4 Algorithm for fluid resuscitation in patients with intussusception. IV, intravenous; GI, gastrointestinal; BW, body weight; pRBCs, packed red blood cells; FFP, fresh frozen plasma.
Many animals presenting with intussusceptions will have moderate to severe abdominal discomfort and nausea. Nausea may be addressed with injectable antiemetics, such as the neurokinin‐1 antagonist maropitant, or 5‐HT3 serotonin receptor antagonists like dolasetron or ondansetron. Metoclopramide administration is not recommended, as its prokinetic properties may contribute to exacerbation of intussusception.
Level of comfort via pain scoring should be determined to develop an optimal analgesic plan. Opioid analgesics are an excellent choice, and may be selected based on availability, degree of pain and likelihood of adverse effects, such as vomiting and respiratory depression. For example, for mild to moderate abdominal pain, an agonist–antagonist opioid such as buprenorphine may be chosen, whereas for severe discomfort, a more potent analgesic such as methadone may be administered.
Patients with devitalized segments of intestine secondary to intussusception are at risk and may develop septic peritonitis secondary to necrosis and breakdown of the GI tract. These patients will frequently present with signs consistent with shock and sepsis, such as a fever, injected mucous membranes, brisk capillary refill time, and bounding pulses, and will require aggressive resuscitation and supportive care. If septic peritonitis is suspected, broad‐spectrum antibiotic therapy should be instituted as soon as possible, as it has been shown to improve outcome in patients with sepsis (see Chapter 11; Peritonitis) [18]. Antibiotics are also recommended if aspiration pneumonia is identified on thoracic radiographs.
Surgical Management
After appropriate stabilization, an abdominal exploratory laparotomy is warranted. Prior to surgery, owners should be counseled on the surgical risks to include general anesthesia, negative exploratory, hemorrhage, dehiscence, incisional complications, reoccurrence, and need for additional surgical procedures. Full assessment of the intestinal tract should be performed to evaluate for any underlying causes such as foreign material or neoplasia. The most common reported sites are enterocolic or enteroenteric (Figure 6.5), and multiple intussusceptions in one patient have been documented [19]. Gastroesophageal, pylorogastric, and colocolic intussusceptions have also been reported [20, 21]. Gastroesophageal intussusception is typically addressed with manual reduction and either a left or bilateral gastropexy. Bilateral gastropexy may potentially limit reoccurrence and prevent future gastric dilatation and volvulus. However, in one study of 36 dogs with gastroesophageal intussusception, reoccurrence had been reported in no dogs following either unilateral or bilateral gastropexy, so unilateral gastropexy may be sufficient. Surgical correction was noted to be difficult in 24% of dogs, with opening of the diaphragm or esophageal hiatus required in some patients [8]. Endoscopy‐assisted correction of gastroesophageal and pylorogastric intussusception has been described but has been reported to have limited success [8,22–24]. Concurrent percutaneous gastrostomy tube placement may aid in securing the stomach in place, providing nutritional support and reducing the chance of reintussusception.
Figure 6.5 Intraoperative photograph of a jejunojejunal intussusception in a cat. Intussusceptum (yellow arrow); intussuscipiens (black arrow).
In the case of intestinal intussusception, manual reduction may be attempted with very gentle traction on the intussusceptum, but in general, resection and anastomosis is recommended, as portions of the intestines are likely to be necrotic or non‐viable (Figure 6.6). After identification of the segment to be removed, the bowel is isolated from the remaining viscera. To perform the resection and anastomosis, jejunal vessels are ligated and divided and the isolated segment of bowel is removed with several millimeters of viable bowel on either side of the intussusception. Anastomosis is performed with 3‐0 or 4‐0 monofilament suture with a hand sewn single layer simple interrupted or simple continuous suture pattern. Alternatively, a 35‐mm skin stapler or mechanical stapling device may be used. After completion of the anastomosis, the suture or stapler line is leak tested and the mesenteric defect is carefully repaired. Following lavage of the anastomosis, omentum may be placed or sutured over the incision.
Figure 6.6 Intraoperative photograph of a small intestinal intussusception in a three‐year‐old female spayed German Shepherd. The dog had surgery one month ago for an intussusception and reintussuscepted at the site of the previous intestinal resection and anastomosis. No enteroplication was performed at the initial surgery. Note areas of devitalized bowel as well as multiple serosal tears of the intussuscipiens.
Source: Reproduced with permission from L.R. Aronson, University of Pennsylvania, Philadelphia, PA, USA, 2014.
In previous reports involving intussusception in 88 dogs, 72 (82%) required resection and anastomosis due to necrosis of involved intestine and/or inability to manually reduce the affected bowel [25]. Laparoscopic management of intussusception has been reported in pediatric patients [26, 27]. In a series of 22 children, 91% were managed entirely laparoscopically, while 2 patients required conversion to open laparotomy. In this series, 46% of patients underwent a bowel resection [26]. In veterinary medicine, use of laparoscopy to identify bowel loops affected by an intussusception and then perform extra corporeal resection and anastomosis has been documented [28, 29]. Another reported method for reduction in an experimental setting has been described using laparoscopic assisted pneumatic reduction. An intussusception was experimentally created in 27 dogs and under laparoscopic observation, CO2 was insufflated into the rectum and the bowel was successfully reduced with grasping forceps in 94% of the dogs [27].
Although the majority of cases require surgical intervention, spontaneous reduction of intestinal intussusception is known to occur in people [30] and has been reported in dogs [31]. In these dogs, clinical signs and imaging were consistent with intussusception but were not confirmed on exploratory laparotomy. Additionally, the duration of clinical signs in these dogs was shorter (median two days), and on ultrasound examination, the intussusception was smaller in diameter and shorter in length, compared with those dogs in which surgery confirmed the presence of an intussusception. It is suggested that analgesia or general anesthesia may allow for relaxation and spontaneous reduction of an intussusception, so it may be advisable to repeat imaging after induction of anesthesia but prior to abdominal exploration.
After reduction or resection of the intussusception, enteroplication may reduce the incidence of future occurrence (Figure 6.7). This procedure is performed by arranging the small intestine in gentle loops side by side from the duodenal colic ligament to the level of the ileum. Adjacent loops of intestine are sutured together, engaging the submucosa [32]. Enteroplication has also been reported using cyanoacrylate tissue adhesive in a series of cats but was reportedly associated with adverse clinical signs and was therefore not recommended for clinical use [33]. In a series of 31 dogs, intussusception reoccurred in 6 of 22 dogs without enteroplication but 0 of 9 dogs that underwent enteroplication, suggesting that enteroplication decreases the probability of reoccurrence with no apparent adverse effects [34].
Complications of enteroplication have been reported and include intestinal volvulus, intestinal perforation with abscess formation, as well as peritonitis [35–38]. To investigate the complications and reoccurrence rates, a study of 35 dogs found that there were no significant differences