Other options include esophagostomy, gastrostomy, or enterostomy tubes (see Chapter 21, Feeding tubes). Ideally, placement of a feeding tube should be considered at the time of the initial surgery, depending on the patient's nutritional status, healing potential, and appearance of the GI tract at surgery. Parenteral nutrition should be considered in patients who have refractory enteral feeding intolerance or in those who are severely malnourished and may have delayed ability to achieve full resting energy requirements solely via enteral route. Important surgical complications to monitor for include dehiscence, peritonitis, and short‐bowel syndrome if a large portion of intestine is resected, as well as reoccurrence of intussusception or obstruction secondary to enteroplication [41].
Prognosis
Prognosis is favorable following uncomplicated reduction or resection. Reoccurrence rates range from 3% to 27% [2, 21] and are usually noted within three days of surgery but have been reported to occur up to three weeks following the procedure in dogs and 12 months after the initial surgery in cats [2, 7]. It appears that reoccurrence may be more frequent in patients undergoing manual reduction rather than resection and anastomosis but no other specific risk factors for reoccurrence have been identified [21]. Persistent regurgitation may occur in animals with gastroesophageal intussusception, in part because of megaesophagus, and adjustments to the feeding regimen may be required to decrease the chance of aspiration. Treatment for any underlying disease process identified should be addressed to minimize reoccurrence of intussusception. Enteroplication may diminish this risk but is not without the potential for serious complications.
7 Rectal Prolapse
Jennifer L. Huck
School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
Etiology
Rectal prolapse is an uncommon condition in dogs and cats. While young animals may be overrepresented [1], there is no documented age, breed, or sex predilection in dogs. Manx cats may be predisposed because of their altered anatomy [2]. Generally, rectal prolapse occurs secondary to an underlying gastrointestinal or urogenital condition (Box 7.1). Both anatomic and functional abnormalities of the anorectal region have been associated with rectal prolapse in small animals [3, 4].
Clinical Evaluation
Evaluation of patients with rectal prolapse begins with a thorough medical history which frequently includes signs such as tenesmus, diarrhea, constipation, or stranguria. Additional required information should include diet, deworming history, concurrent medical problems, and current medications. This information is integral to determining a primary cause for the prolapse [5].
A thorough physical exam will readily lead to a diagnosis of rectal prolapse. Rectal prolapse is considered to be partial when only the rectal mucosa protrudes from the anus whereas a complete prolapse occurs when all layers of rectum are protruding through the anal orifice [6, 7]. A digital rectal exam is a critical part of the physical but may be impossible in more severely affected patients at the time of presentation. Additionally, a complete prolapse must be differentiated from a prolapsed intussusception which is a surgical emergency. To differentiate the two conditions, the clinician should pass a blunt, lubricated instrument or thermometer between the prolapsed tissue and the anal wall. The instrument tip cannot be advanced due to the presence of the fornix between the rectum and the anus in cases of rectal prolapse (Figure 7.1) [5].
Depending on the underlying cause of the prolapse, patients may present dehydrated, hypovolemic, hypotensive, tachycardic, painful, and exhibiting other signs consistent with shock. These patients should be stabilized with intravenous fluids and pain medications prior to pursuing additional diagnostics or treatment. In many cases, patients are relatively stable, even when suffering with large, complete prolapses. The affected tissues can exhibit severe edema, swelling, and congestion. Viability of the prolapsed tissues must be determined; evidence of significant trauma or necrosis are both indications for urgent surgical intervention for rectal resection and anastomosis.
Diagnostics should be tailored toward each patient based on the history and physical exam findings. At a minimum, fecal flotation, fecal culture, complete blood count, serum chemistry, urinalysis with or without urine culture, and abdominal radiography or ultrasonography should be recommended. Abdominal computed tomography, thoracic radiographs, and endoscopic imaging and biopsies can also be considered, especially in cases of recurrent prolapse or when a neoplastic process is suspected.
Treatment
Correction of the rectal prolapse is only the first step in providing appropriate treatment for these patients. Underlying diseases that contributed to prolapse formation must also be addressed as failure to do so may increase the risk of prolapse recurrence [1, 5].
Box 7.1 Conditions Associated with Rectal Prolapse in Small Animals
Gastrointestinal parasitism
Intestinal neoplasia
Colitis
Proctitis
Intestinal foreign body obstruction
Colonic duplication
Rectal polyps
Rectal sacculation following perineal hernia repair
Dysuria
Urolithiasis
Vaginal prolapse
Dystocia
Prostatitis/prostatic disease
Figure 7.1 Cat with rectal prolapse. Note the minimal ability to insert hemostats along the prolapsed tissue. This is in contrast to colorectal or jejunorectal intussusception, where the hemostat would be able to slide easily into the space between the mucosal layers.
Source: Image courtesy of L. Aronson.
Reduction of Prolapse
Prolapse reduction should be attempted in any patient where the exposed tissue is deemed viable. Most prolapses can be reduced with appropriate interventions.
For partial and smaller, acute complete prolapses, reduction can typically be achieved with the patient heavily sedated. Tissues should be thoroughly lavaged with warm, sterile, isotonic solution and sterile lubrication generously applied. Application of gentle, continuous pressure to the prolapse should result in reduction at which point a purse‐string suture can be placed at the anal mucocutaneous junction, taking care to avoid the anal sac
