Surgical procedure
Each dog was slowly administered dexmedetomidine (1 µg/kg) and methadone
(0.2 mg/kg) intravenously. Anesthesia was induced intravenously with
propofol (initial bolus of 2 mg/kg over 60 seconds followed by
incremental bolus doses of 0.5 mg/kg) and maintained using isoflurane in
oxygen. A urinary catheter was placed and the metacarpal artery was
catheterized. The intraoperative blood pressure was monitored using both
invasive and noninvasive techniques. Cefazolin (22 mg/kg) was
administered intraoperatively at induction and every 90 minutes
thereafter. A loading dose of meloxicam (0.2 mg/kg) was administered
intravenously following induction. Intraoperatively, the dogs received a
loading dose of lidocaine (2 mg/kg) intravenously followed by lidocaine
CRI (33 µg/kg/min) and fluid therapy with lactated Ringer’s solution
(6-7 mL/kg/h).
Each dog was positioned in dorsal recumbency, and both the ventral
abdomen and the perineal area were prepared for surgery. A ventral
midline abdominal approach was used, starting from the xiphoid to the
pubis, and showed a moderate amount of peritoneal effusion.
To increase the colorectal exposure, bilateral pubic and ischial
osteotomies were carried out. The division between the right and left
adductor muscles was incised sharply, taking care to stay exactly on the
midline to minimize the risk of hemorrhage. The adductor muscles were
then elevated subperiosteally from the pubis and ischium with a
0.25-inch Key periosteal elevator. Then, elevation was continued until
the obturator nerves and approximately two-thirds of the obturator
foramina were visible. The prepubic tendon was incised along the pubis
to the level of the proposed pubic osteotomy sites, and a 2-mm pin chuck
was used to drill two holes on either side of the four proposed
osteotomy sites. The osteotomies of the right and left pubis and ischium
were then created using a sagittal oscillating saw. The internal
obturator nerves were protected with a malleable retractor while the
osteotomies were performed. The internal obturator muscle was elevated
subperiosteally from the right pubis and ischium, allowing for the
resection of the central bony plate to the left. Upon increased
colorectal exposure, an anastomotic dehiscence was evident (Figure 1A).
Initially, the dehiscence was isolated by sterile gauze. Debridement and
primary closure of the colon and rectal stumps were attempted, which
resulted in tension upon closure. To decrease the tension on the
anastomosis, a jejunal grafting technique was utilized. A 5-cm segment
of healthy jejunum (Figure 1B), including the jejunal artery and vein,
were isolated and mobilized from the middle of the jejunum. The graft
donor site was closed using an end-to-end anastomosis with a 4-0
polydioxanone suture (PDS) in a simple, continuous appositional pattern
(Figure 1C). The pedicled jejunal segment was transposed to the
anastomotic site. Cranially, the rectal and jejunal stumps were sutured
in place using an end-to-end anastomosis with a 4-0 PDS in a simple
interrupted pattern (Figure 2A). The rectal portion was hard to scarify
and anastomose using this approach. The use of a transanal technique was
thus necessary. The jejunal caudal stump was closed with a 4-0 PDS using
a continuous Parker-Kerr inverting suture technique. A Doyenne clamp was
inserted through the anus into the abdomen by a second surgeon to pull
out the caudal jejunal stump through the anus (Figure 2B). The abdomen
was lavaged with 5 L sterile saline, and a Jackson Pratt drain was
placed in the peritoneal cavity and was closed without complications.
The dog was then positioned in sternal recumbency and the perineal
surgical field was prepared using an external operator. The jejunal
caudal stump was externalized using a Doyenne clamp, and the Parker-Kerr
suture was removed. A transanal-rectal-jejunal end-to-end anastomosis
was performed using a 4-0 PDS in a simple continuous appositional
pattern. The jejunal-rectal anastomosis was then replaced through the
anus (Figure 2C).
Major complications were classified as a dehiscence of one or both of
the anastomotic sites and severe rectal bleeding, whereas minor
complications were classified as tenesmus, leakage, diarrhea, and fecal
incontinence.