Linear-Stapled Gastrointestinal Anastomosis

In human and veterinary medicine, stapling devices have been developed for GI surgery, and a variety of different stapling techniques for intestinal anastomosis have been described, including^1-10:

• Everting, triangulating end-to-end anastomosis (EEA) using a thoracoabdominal linear stapler 
• Inverting EEA using an EEA circular stapler
• EEA using a skin stapler 
• Antiperistaltic side-to-side (ie, functional end-to-end) anastomosis using a GI anastomosis (GIA) linear and/or cutting stapler

Stapled GIA in dogs and cats and, more recently, a technique in dogs for a stapled functional end-to-end anastomosis (SFEEA) using only a GIA stapler have also been reported.^10,11 Ideally, SFEEA is used following enterectomy of the jejunum and/or ascending duodenum based on the mobility of this portion of the small intestine. Other portions of the intestine (eg, duodenum, large intestine) are more fixed because of the short mesentery, precluding the use of this technique. 

Studies have been conducted to evaluate the technique and outcome of SFEEA in veterinary medicine.^1,12-14 Potential benefits of SFEEA as compared with hand-sewn anastomosis include reduced procedure time, decreased tissue trauma, decreased intraoperative contamination, consistency and repeatability of the anastomosis, and preservation of blood supply.^13-15 In addition, severe luminal disparity between 2 cut bowel ends (eg, severe segmental dilation orad to an obstructive foreign body) can be readily resolved via SFEEA. A multi-institutional retrospective study in dogs demonstrated no significant difference in anastomosis dehiscence rates or decreased procedure time with SFEEA as compared with hand-sewn anastomosis.¹² 

Disadvantages of SFEEA as compared with hand-sewn anastomosis include the learning curve required to perform the procedure and the inability to perform this procedure in areas of the GI tract other than the jejunum and ascending duodenum. An additional limiting factor of stapled anastomosis may be financial investment, with SFEEA instruments and staple cartridges costing 15 to 25 times more than suture costs.¹⁴ However, in some institutions, the total procedural time saved may result in equivalent overall costs between SFEEA and hand-sewn anastomosis.

Preoperative peritonitis, a serum albumin concentration less than 2.5 g/dL (25 g/L), and presence of an intestinal foreign body are classically reported risk factors for intestinal anastomosis dehiscence following hand-sewn anastomosis.¹⁶ In a retrospective study examining risk factors specifically related to SFEEA dehiscence, preoperative presence of inflammatory bowel disease, intraoperative hypotension, and resection and anastomosis involving the large intestine were identified as risk factors.¹⁴ 

Preoperative peritonitis was examined and was not an identified risk factor for SFEEA, contrary to previous reports.¹⁴ Furthermore, in another retrospective study, SFEEA was found to be less likely to undergo dehiscence as compared with hand-sewn intestinal anastomosis in dogs with preoperative septic peritonitis.¹

With proper instruction, SFEEA has been demonstrated to be a reliable tool for surgeons and may be useful during emergency situations to decrease operative time in unstable patients when a rapid anastomosis is required and to potentially decrease dehiscence risk in patients with septic peritonitis.^13,14

• Standard surgical instrument kit
• Balfour retractor
• GIA stapler (60-mm and/or 80-mm or 100-mm for medium-to-large–breed dogs) and blue staple cartridges that correspond in length to the stapler
• Doyen intestinal forceps (atraumatic; 2 pairs)
• DeBakey thumb forceps (2 pairs)
• Traumatic forceps (eg, Rocheter-Carmalt; 1 pair)
• Suture material (3-0 monofilament, absorbable)

Anesthetize the patient and place in dorsal recumbency. Administer antimicrobial therapy (eg, cefoxitin [30 mg/kg IV for clean-contaminated surgery]) 30 minutes before incision and every 90 minutes thereafter until skin closure; of note, recent data suggest that q4h administration of cefoxitin is also acceptable.¹⁷ Clip, prepare, and drape the ventral abdomen for aseptic surgery.

Perform a ventral midline exploratory laparotomy and remove the falciform ligament to improve abdomen exposure, then place a Balfour retractor. Explore the abdomen thoroughly in a systematic fashion, and isolate the affected intestinal segments with multiple layers of saline-soaked laparotomy sponges. Perform an enterectomy and, if indicated, submit for histopathologic evaluation.

After resecting the affected intestine, milk the intestinal contents orally and aborally to the Doyen forceps (A). Place a second pair of Doyen forceps approximately 10 cm orally and aborally to the first set of Doyen forceps (B). This technique is employed to minimize contamination when using the stapling devices for anastomosis, as the initially placed pair of forceps will be removed on staple application.

Place 2 stay sutures (eg, 3-0 polydioxanone) into the cut ends of each intestinal segment on the mesenteric border. Once the stay sutures have been applied, remove the first pair of Doyen forceps directly at the cut bowel ends; leave the second pair in place until the stapled anastomosis is complete. Use the stay sutures to elevate the bowel ends and to facilitate insertion of each fork of the GIA stapler (A). It is important to ensure symmetrical apposition of the antimesenteric border of the intestine before locking the stapler. The authors recommend apposition of the antimesenteric borders of the bowel because this can help minimize incidence of trauma to the vascular supply on the mesenteric border.

When placement is deemed adequate, lock and fire the forks, creating the side-to-side opening between the bowel lumens (B). After firing, disengage and remove the forks. Carefully inspect the anastomosis site to ensure proper staple placement, which is dependent on passage of the staple fully through both layers of the adjacent intestinal wall and on consistent closure of the B-shaped staple on the opposite tissue edge. 

Using the previously placed stay sutures for handling the intestinal segments, place the GIA stapler (with a new loaded cartridge) perpendicular to the lumen of the intestine. Before locking, offset the staple rows from the lumens portion using 2 pairs of DeBakey thumb forceps. This prevents the initial staple lines from being stacked on top of each other, which could prevent complete engagement of the staples through both walls of the terminal end of the SFEEA. Lock and fire the stapler. The authors generally aim to leave 1 mm to 3 mm of tissue beyond the edge before firing the GIA stapler. The GIA stapler will automatically transect the bowel, resulting in a 2-row stapled edge creating the “waist.” The remaining tissue at the terminal end of the SFEEA does not need to be oversewn.

Two simple interrupted, prolonged absorbable monofilament sutures should be placed just below the base (ie, point of the “V” intersecting GIA staple line) of the anastomosis to minimize tension on the staple line (A). These sutures should aim to capture submucosa for holding power (B).

Remove the laparotomy sponges from the surgical field. With a new pair of sterile surgery gloves, use a separate sterile closure pack to complete the laparotomy. Lavage the abdomen thoroughly with sterile saline. Using a monofilament absorbable suture, close the mesenteric defect in either an interrupted, cruciate, or continuous pattern. Avoid damaging adjacent vasculature supplying the anastomosed bowel in the mesentery. Drape the omentum over the anastomosis site before closing the abdominal incision in a routine fashion, and perform a routine closure of the abdomen.