Key Points

 Gastrointestinal (GI) exploratory laparoscopy can be performed safely in dogs and cats provided that the minimally-invasive surgeon is thorough and possesses sound decision making ability.

 Laparoscopic-assisted GI surgery is ideal for a subset of dogs and cats suspected of inflammatory bowel disease or alimentary neoplasia and for dogs and cats with jejunal segment obstruction due to a foreign body.

 Contraindications to laparoscopic GI surgery include: septic peritonitis, linear foreign body and intestinal adhesions.

Minimally invasive gastrointestinal (GI) surgery is indicated when information gathered by visualization and/or sampling of the gastrointestinal tract will help with therapeutic decision making in veterinary patients. Gastrointestinal disease in dogs and cats is common and the specific indications for diagnostic and therapeutic GI laparoscopy are not well defined but are increasing. Gastrointestinal diseases for which laparoscopy is reported for diagnosis and treatment include: foreign bodies, neoplasia, inflammatory, immune-mediated and infectious processes. Dogs and cats with obstructive or nonobstructive GI disease can benefit from exploratory laparoscopy.

Patient Selection

Diagnostic laparoscopic GI exploratory selection criteria have not been determined for dogs and cats. However, a recent study looking at conversion rates from diagnostic laparoscopy to laparotomy found that a low preoperative total solids, presence of a solitary liver tumor and diagnosis of neoplasia were associated with an increased risk of conversion to laparotomy (Buote et al. 2011). In the same study, a total conversion rate of 21% was determined. There are currently only two clinical reports describing the use of diagnostic and therapeutic GI laparoscopy in dogs and cats (Gower, Mayhew 2011; Case, Ellison 2013). Both of these studies utilized a laparoscopic-assisted technique to explore the GI tract and reported excellent outcomes with few complications. However, conversions were reported in both case series, and a number of limitations and potential contraindications were speculated at. For example, lesion diameter appears to be important and the author considers an intestinal lesion diameter of ∼5 cm to be a reasonable upper limit when considering a laparoscopic-assisted approach in most dogs and cats (Case, Ellison 2013). Similar lesion sizes have been proposed in human laparoscopic-assisted GI surgery but there are conflicting recommendations. Large diameter lesions require significant enlargement of the port incision and may obviate some of the benefits of a minimal approach. The specific region of the affected bowel also appears to be important when considering patients as candidates for laparoscopic-assisted GI exploration. Dogs and cats with GI lesions affecting the stomach, orad duodenum or bowel aborad to the ICJ may not be ideal candidates for a laparoscopic-assisted approach if significant exteriorization is required for complete evaluation and treatment (Gower, Mayhew 2011; Case, Ellison 2013). Adhesions of the GI tract appear to be a contraindication to laparoscopic-assisted GI exploration in dogs and cats as well. Adhesions tether bowel to the mesentery and to other bowel segments, which results in the inability to safely exteriorize bowel from the peritoneal cavity without significant lengthening of port incisions (Case, Ellison 2013). Other potential contraindications for GI laparoscopy in dogs and cats include: GI perforation, septic peritonitis, linear foreign bodies, association with adjacent structures such as the common bile duct or pancreas, and inexperience of the surgery team.

Patient Position

Patients are positioned in dorsal recumbency and prepared using standard aseptic technique. An operating table with the capacity for Trendelenburg and reverse Trendelenburg position is recommended. Additionally, a laparoscopic positioner or motorized float table is recommended when performing exploratory GI laparoscopy as alteration of the patient's position is often necessary. In small patients (cats and dogs <10 kg), however, the mechanical tilt table can be cumbersome and its use is not necessary. Rather, the patient's position can be altered intermittently by the operating room technician and the dog or cat can be stabilized in lateral recumbency using sand bags. The surgeon and assistant should stand on the left or right of the patient towards the foot of the table. Video monitors should be available at the head of the table on the right and left side (Figure 1). A single monitor is acceptable as long as it can easily be moved to the opposite side of the surgeon performing the exploration.

Figure 1. Schematic illustration of the OR set up during GI laparoscopic surgery

Ports and Placement

Port type and position depends on the technique to be performed (single versus multiple cannula) and the anticipated location of the lesion within the abdominal cavity. With single port procedures, a 20–30 mm skin incision is made 1–2 cm caudal to the umbilicus on midline. Threaded cannulas are recommended for multiport procedures to prevent slippage of the cannula from within the peritoneum. The cannulas are placed either after peritoneal insufflation using a Veress needle or by the Hasson method.

Laparoscopic-Assisted GI Exploratory

The gastrointestinal tract can be challenging to explore completely and accurately using laparoscopy due to its length as well as its variation in size and location within the peritoneal cavity. For example, the stomach and orad duodenum are relatively deep and fixed within the cranial abdomen, which makes extracorporeal evaluation impractical. In contrast, the small intestine just aborad to the duodenocolic ligament through the ileocecocolic junction is ideal for extracorporeal evaluation and is easily accomplished with a minimal assist incision. Because GI disease often affects the upper and lower GI tract of dogs and cats, the operating surgeon must pay careful attention to technique when performing laparoscopic-assisted GI exploratory and ensure that all regions are adequately examined. Otherwise, GI lesions will be missed and an unacceptable level of morbidity may result. Gastrointestinal laparoscopy should be performed systematically and in the same manner between patients. A cranial-to-caudal and side-to-side approach has been most useful in the author's experience.

Laparoscopic & Laparoscopic-Assisted Gastrotomy

Laparoscopic gastrotomy for the removal of gastric foreign bodies has been described in 20 clinical dogs (Lew et al. 2005). In this report a midline, 3-port technique was utilized and gastrotomy was closed in a single inverted pattern or with an endoscopic surgical stapler. Foreign bodies were removed using an endoscopic retrieval bag and contamination was minimal. Clinical outcome was good in all dogs with no complications reported.

Enterotomy and Intestinal Biopsy

Laparoscopic-assisted enterotomy has been described using a two-port (Gower, Mayhew 2011) and single port (Case, Ellison 2013) technique with or without a wound retractor device. Both techniques require laparoscopic exploration. Once the intracorporeal exploratory is completed a segment of jejunum is exteriorized from the peritoneum and the small intestine is ran through eventually leading to extracorporeal isolation of the affected segment of bowel. The assist incision may need to be minimally enlarged to facilitate exteriorization and to prevent strangulation of the mesenteric vasculature. A baby Gelpi or polyurethane wound retractor is used to maintain retraction of the abdominal wound during the extracorporeal enterotomy and the affected bowel is isolated and packed off using laparotomy sponges. Use of a polyurethane wound retractor is preferable in cases of suspected or documented GI neoplasia in order to minimize the risk of port site metastasis (Gower, Mayhew 2011).

Enterectomy & Anastomosis

Laparoscopic-assisted, intestinal resection and anastomosis is performed in humans for small bowel obstruction of various causes including, small bowel tumors, inflammatory bowel disease and postoperative adhesion formation. In most instances, resection and anastomosis is performed extracorporeally using standard techniques after the affected bowel has been exteriorized via the extraction incision. In veterinary surgery, laparoscopic-assisted enterectomy and anastomosis has been performed for small intestinal intussusception (Case, Ellison 2013) and neoplasia (Gower, Mayhew 2011). This approach appears to minimize tissue trauma, visceral manipulation and peritoneal contamination.

Complications

Reported complications associated with laparoscopic GI surgery in veterinary surgery are limited to inability to evaluate specific regions of the intestinal tract and necessity for conversion to laparotomy, 13% (Gower, Mayhew 2011; Case, Ellison 2013) or minor incisional alteration, 38% (Case, Ellison 2013). Although the efficacy of laparoscopic-assisted exploration has not been evaluated in a controlled manner, preliminary results are excellent assuming appropriate case selection and decision making by the operating surgeon. Complications reported in human laparoscopic GI surgery include: perforation of viscera with laparoscopic instrumentation, hemorrhage and wound infection.

References

1.  Buote NJ, Kovak-McClaran JR, Schold JD. Conversion from diagnostic laparoscopy to laparotomy: risk factors and occurrence. Vet Surg. 2011;40(1):106–114.

2.  Sharma A, Thompson MS, Scrivani PV, et al. Comparison of radiography and ultrasonography for diagnosing small-intestinal mechanical obstruction in vomiting dogs. Vet Radiol Ultrasound. 2011;52(3):248–255.

3.  Fields EL, Robertson ID, Brown JC Jr. Optimization of contrast-enhanced multidetector abdominal computed tomography in sedated canine patients. Vet Radiol Ultrasound. 2012;53(5):507–512.

4.  Gower SB, Mayhew PD. A wound retraction device for laparoscopic-assisted intestinal surgery in dogs and cats. Vet Surg. 2011;40(4):485–588.

5.  Case JB, Ellison G. Single incision laparoscopic-assisted intestinal surgery (SILAIS) in 7 dogs and 1 cat. Vet Surg. 2013;42(5):629–634.

6.  Lew M, Jalynski M, Brzeski W. Laparoscopic removal of gastric foreign bodies in dogs - comparison of manual suturing and stapling viscerosynthesis. Pol J Vet Sci. 2005;8(2):147–153.