RETROSPECTIVE STUDIES

Gastrointestinal Perforation Associated With Endoscopy in Cats and Dogs Sara Irom, MS, DVM*, Robert Sherding, DVM, DACVIM, Susan Johnson, DVM, DACVIM, Paul Stromberg, PhD, DVM, ACVP (Veterinary Pathology)

ABSTRACT Gastrointestinal endoscopy is a minimally invasive diagnostic tool for cats and dogs with signs of gastrointestinal disease. This retrospective study examined the case records of six cats and one dog diagnosed with perforation secondary to gastrointestinal endoscopy. Gastrointestinal perforation occurred in 1.6% of cats and 0.1% of dogs that underwent endoscopy during the 17 yr study period (from 1993 to 2010). It can be difficult to predict what animals are at risk for gastrointestinal perforation but possible risk factors suggested by this study include small intestinal infiltrative disease in cats and preexisting gastrointestinal ulceration in both cats and dogs. Overall, gastrointestinal endoscopy is associated with a low rate of gastrointestinal perforation. (J Am Anim Hosp Assoc 2014; 50:322–329. DOI 10.5326/JAAHA-MS-5727)

Introduction

retrospective study was to evaluate the prevalence, associated

Gastrointestinal endoscopy is commonly performed for the di-

underlying disease, anatomic location, and outcome of gastroin-

agnosis and treatment of gastrointestinal disease in cats and dogs.

testinal perforations associated with diagnostic endoscopy in cats

Endoscopy is a minimally invasive diagnostic procedure that is

and dogs.

used to evaluate the mucosal surfaces of the esophagus, stomach, small intestine, and colon. Endoscopy can also be used to obtain

Materials and Methods

specimens for histopathology, cytology, and microbial analysis.1,2

Medical records of cats and dogs with gastrointestinal perforation

Endoscopes are also used to assist in removal of esophageal and

that occurred during endoscopy at the authors’ hospital between

gastric foreign bodies and to assist in dilation of esophageal and

April 1993 and March 2010 were reviewed. Those dates were

1,2

Complications secondary to gastrointestinal

chosen to include all searchable gastrointestinal and colonoscopic

endoscopy are rare, but can include gastrointestinal perforation,

examinations in the study authors’ endoscopy database. Perfo-

hemorrhage from laceration of major blood vessels, and anes-

rations that occurred as a result of either foreign body manipu-

thetic complications associated with gastric over distension and

lation or dilation of esophageal strictures were excluded because

colonic strictures.

2

decreased venous return. Perforation during endoscopy is a rec-

published retrospective studies have addressed complication rates

ognized complication of endoscopic foreign body retrieval and

associated with those procedures.3–5 Information from medical

esophageal stricture dilation.3–5 However, gastrointestinal perfo-

records included signalment, clinical signs at the time of hospital

ration occurs rarely in cats and dogs undergoing routine diag-

admission, duration of clinical signs, physical examination

nostic endoscopy and biopsy. Either poor biopsy technique or

findings, results of clinical laboratory tests, diagnostic imaging

forceful insertion of the endoscope without visualization of the

findings, endoscopic findings, location of perforations, histo-

lumen have been cited as risk factors. The ob jective of this

pathological findings, and clinical diagnosis. Perforation was

From the Great Lakes Veterinary Specialists, Cleveland, OH (S.I.); and Department of Veterinary Clinical Sciences (R.S., S.J.) and Department of Veterinary Biosciences (P.S.), The Ohio State University, Columbus, OH.

*S. Irom’s updated credentials since article acceptance are DVM, MS,

6

DACVIM.

Correspondence: [email protected] (S.I.)

322

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ª 2014 by American Animal Hospital Association

Gastrointestinal Perforation with Endoscopy in Cats and Dogs

defined as iatrogenic if it occurred either during endoscopic

Treatments, outcome, and survival times were recorded for all

maneuvering or biopsy. Perforation was defined as secondary to

cats and dogs discharged from the hospital, and the cause of death

chronic ulceration if it occurred during insufflation, an ulcer was

and results of postmortem examinations were recorded when

detected at laparotomy, and the ulcer was determined to be pre-

available. Histological slides of sections of biopsy specimens from

existing based on histologic evidence of fibrosis around the ulcer

each case were reviewed by a single pathologist for confirmation of

margins.7 The presence of fibrosis indicates chronic ulceration of

the histopathological diagnosis using published standards.8

.3–5 days in duration.7 In preparation for gastrointestinal endoscopy, food was

Results

withheld for a minimum of 12 hr. In preparation for colonoscopy,

A total of 377 cats and 1240 dogs were identified by a retrospective

food was withheld for a minimum of 24 hr and at least 2 warm-

search of medical records as undergoing gastrointestinal endos-

water enemas were administered, and some dogs had two doses of

copy, colonoscopy, or both procedures during the 17 yr study

polyethylene glycol colonic lavage solutiona (20 mL/kg per os) at

period. This included 267 cats and 812 dogs each undergoing

least 2 hr apart on the afternoon of the day before the procedure.

a single gastrointestinal endoscopy, 37 cats and 249 dogs under-

Gastrointestinal endoscopy and colonoscopy were performed in

going a single colonoscopy, and 73 cats and 179 dogs undergoing

left lateral recumbency under inhalant general anesthesia. Pre-

both procedures. No cases had repeated endoscopic procedures.

medications varied, and were chosen by the preference of the

Six cats and one dog were identified as having gastric or

attending anesthesiologist. A flexible videoendoscope (8.5 mm in

intestinal perforation associated with upper gastrointestinal en-

diameter, 2.2 mm channel, 103 cm in length) was used for gas-

doscopy (Table 1). Perforations occurred in the stomach (fundus

troduodenoscopy in cats. A flexible videoendoscope (9.4 mm

and body) and duodenum only. No patients were identified as

in diameter, 2.8 mm channel, 103 cm in length) was used for

having perforation associated with colonoscopy. Gastrointestinal

gastroduodenoscopy in dogs, and a flexible videoendoscope

d

perforation occurred in 1.6% of cats and 0.1% of dogs that

(8.6 mm in diameter, 2.8 mm channel, 140 cm in length) was

underwent endoscopy. In three of seven cases (cases 1, 2, and 3),

used for colonoscopy in cats and dogs. Isotonic electrolyte solu-

the perforations were associated with preexisting ulcers. In four

tion was administered by indwelling IV catheter throughout each

of seven cases (cases 4–7), the perforations were considered

procedure, and routine cardiovascular and respiratory parameters

iatrogenic.

b

c

were monitored.

Of the six cats with perforation associated with endoscopy,

For gastrointestinal endoscopy, the esophagus, stomach body,

three were castrated males and three were spayed females.

angularis, antrum, pylorus, and duodenum were systematically

Breeds included domestic shorthair (n ¼ 3), Siamese (n ¼ 2), and

visualized as the scope was advanced to several centimeters past the

Himalayan (n ¼ 1). The mean age of the cats was 12.3 yr (range,

duodenal bile duct papilla. As the endoscope was withdrawn back

8–17 yr). The mean body weight of the cats was 3.3 kg (range,

into the stomach, it was retroflexed to view the cardia, the fundus,

2.2–4.9 kg). The dog was a 10 yr old spayed female cocker spaniel

and lesser curvature. For colonoscopy, the endoscope was advanced

weighing 10.3 kg.

from the rectum to the cecocolic region. The distal ileum was

Clinical signs reported by owners at presentation included

examined whenever possible. Insufflation was used as needed to

vomiting (n ¼ 5), inappetence (n ¼ 4), weight loss (n ¼ 4),

optimize viewing of mucosal surfaces during the exam. Distilled

lethargy (n ¼ 4), diarrhea (n ¼ 2), and melena (n ¼ 1) as

water was infused through the irrigating channel of the endoscope

summarized in Table 1. The mean duration of clinical illness was

as needed to clear mucus, bile, hair, food particles, or feces that

10 mo (range, 3 days to 2 yr). The physical examination abnor-

obscured the mucosa. Endoscopic mucosal biopsies were obtained

malities were also listed in Table 1 and included cachexia (n ¼ 4),

using flexible forceps passed through the endoscope’s operating

dehydration (n ¼ 4), gas-filled intestinal loops (n ¼ 2), heart

channel from each region, including the duodenum, pyloric

murmur (n ¼ 2), palpably thickened intestinal loops (n ¼ 1), pale

antrum, gastric body, and cardia/fundic region for gastro-

mucous membranes (n ¼ 1), and renal asymmetry (n ¼ 1). One

duodenoscopies, and the colon and ileum for colonoscopies.

cat defecated during abdominal palpation.

Supervision of inexperienced endoscopists consisted of close ob-

Complete blood cell counts and serum biochemical evalua-

servation and instruction during the procedure by an experienced

tion were performed at the time of hospital admission in four cats

endoscopist. When necessary, control and advancement of the

and one dog. The remaining two cats (cases 1 and 6) had a

endoscope was performed by an experienced endoscopist if the

complete blood cell count performed within 1 wk prior to ad-

inexperienced endoscopist was unable to do so safely.

mission. Clinically relevant laboratory abnormalities for each case

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kocytosis (n ¼ 3), thrombocytosis (n ¼ 1), thrombocytopenia

Unknown

(n ¼ 1), as well as hypoalbuminemia (n ¼ 3), hypoglobulinemia (n ¼ 3), and hypocalcemia (n ¼ 2). Serum cobalamin and folate

Heart failure

Euthanasia at surgery

N/A

Unknown

Euthanasia

N/A

Cause of Death

have been listed in Table 2. Those include anemia (n ¼ 3), leu-

concentrations were measured in two cats (cases 2 and 4) and were abnormal in case 4. Increased serum gastrin concentrations

324

.6 yr

.4 mo

0

8 mo

Unknown

3 wk

17 mo

Follow-up Time

published studies.9–11 Abdominal radiographs were taken prior to endoscopy in one cat (case 7) and the dog, and were suggestive of gastric foreign

JAAHA |

doscopy, and exploratory laparotomy in each case have been listed doscopy in three cats and the dog. Abnormalities included altered

Iatrogenic

Iatrogenic

Iatrogenic

in Table 3. Abdominal ultrasound was performed prior to enIatrogenic

Preexisting ulcer site

Preexisting ulcer site

Preexisting ulcer site

body in both. Pertinent findings for abdominal ultrasound, enPerforation Type (Preexisting or Iatrogenic)

layering of the small intestinal wall (n ¼ 1), diffusely thickened gastric and small intestinal walls (n ¼ 1), thickened and corru-

50:5 Sep/Oct 2014

effusion (n ¼ 1). Endoscopic examination findings were reported in the medical record for the stomach (n ¼ 6) and for the duoCM, castrated male; DSH, domestic shorthair; IBD inflammatory bowel disease; N/A, not applicable; SF, spayed female.

Lymphoma Vomiting

Vomiting, inappetence, lethargy, dehydration, heart murmur 14 yr old SF DSH

12 yr old CM Himalayan 6

IBD, lymphocytic portal hepatitis

larged mesenteric lymph nodes (n ¼ 1), and trace peritoneal

7

Large (B) cell lymphoma Vomiting, weight loss, cachexia, palpably thickened intestine 8 yr old SF DSH 5

Small cell lymphoma Weight loss, diarrhea, cachexia, gas-filled intestine, defecated during exam 10 yr old SF Siamese

10 yr old CM cocker spaniel 3

4

Chronic duodenal ulcer, gastrinoma Chronic duodenal ulcer, gastrinoma Inappetence, lethargy, dehydration, heart murmur, renal asymmetry Vomiting, inappetence, weight loss, lethargy, diarrhea, melena, cachexia, dehydration, gas-filled intestine 17 yr old CM Siamese 2

Chronic duodenal ulcer, IBD Vomiting, inappetence, weight loss, lethargy, cachexia, dehydration, pale mucous membranes 13 yr old CM DSH 1

Signalment

Clinical Signs and Physical Examination Abnormalities

Clinical Diagnosis

gated duodenum (n ¼ 1), gas in the intestinal wall (n ¼ 1), en-

Case

Summary of Clinical Signs, Diagnoses, and Outcomes of Six Cats and One Dog With Gastrointestinal Perforation Associated With Endoscopy

TABLE 1

were found in cases 2 and 3. Reference ranges were based on

denum (n ¼ 5), and visible lesions were found in all animals examined. Abnormal findings in the stomach included thickened gastric folds (n ¼ 2), gastric mass (n ¼ 1), irregular gastric mucosa (n ¼ 1), multiple gastric nodules (n ¼ 1), and thickened gastric folds with nodular appearance (n ¼ 1). Abnormal findings in the duodenum included thickened duodenal folds (n ¼ 2), hyperemic duodenal mucosa (n ¼ 1), multifocal duodenal ulcers (n ¼ 1), irregular mucosa with nodules (n ¼ 1), and multifocal hemorrhages (n ¼ 1). Full endoscopic examination was not completed in case 2 because of severe abdominal distension (pneumoperitoneum) on initial insufflation of the stomach. Duodenoscopy was not completed in case 5 because the gastric mass prevented entry through the pylorus. In all cases, perforation was diagnosed either during or immediately after the endoscopic procedure. Abdominal distension, which did not decrease with suctioning air from the stomach, was observed during the endoscopic procedure in all cases, and tense pneumoperitoneum was noted in three cats (cases 1, 2, and 4). The perforation site was visualized during endoscopy in two cases. In case 4, a full-thickness tear was identified at a duodenal biopsy site, and in case 6, the peritoneal cavity was visualized through a tear in the wall of the gastric fundus as the endoscope was withdrawn from the duodenum into the stomach. In five cases, perforation was diagnosed by abdominocentesis, which yielded air, indicative of pneumoperitoneum. Abdominal radiographs confirmed pneumoperitoneum in the three cases in which they were performed (Figure 1). The endoscopic manipulations that were associated

Gastrointestinal Perforation with Endoscopy in Cats and Dogs

TABLE 2 Selected Results of Complete Blood Cell Count and Serum Biochemical Analysis in Six Cats and One Dog With Gastrointestinal Perforation Associated With Endoscopy Case

PCV (%)

Reticulocytes (3109/L)

WBCs (3109/L)

Platelets (3109/L)

Albumin (gm/L)

Globulin (gm/L)

Calcium (mmol/L)

Cobalamin (pmol/L)

Folate (nmol/L)

Gastrin (pmol/L)

Feline reference ranges*

25–46%

,60

4.0–14.5

150–600

25–35

31–41

2.10–2.52

214–1106

22.0–48.9

4.8–19.2

15 17

183 106

34.6 26.5

830 146

24 27

30 28

1.77 2.40

NP 284

NP 44.4

NP 140.5

1 2 4

37

NP

10.8

234

33

37

2.42

,111

85.6

NP

5

34

NP

14.4

NP

20

33

2.17

NP

NP

NP

6

36

NP

8.3

NP

35

32

2.37

NP

NP

NP

7

37

NP

4.9

168

35

39

2.40

NP

NP

NP

35–50

,60

4.1–15.2

150–450

29–42

31–41

2.32–2.89

N/A

N/A

4.8–19.2

24

NP

41.1

254

26

27

1.82

NP

NP

439.6

Canine reference ranges 3

*Reference ranges for gastrin levels were based on previously published reference ranges.9–11 N/A, not applicable; NP, not performed; PCV, packed cell volume.

with perforation in each case have been listed in Table 3 and

vincristine, cytosine arabinoside, and prednisolone based on the

included initial gastric insufflation at entry into the stomach (n ¼

thickened appearance of the gastric walls and the high clinical

1), insufflation of the duodenum during duodenoscopic examina-

suspicion for lymphoma. Two cats (cases 1 and 2) were also

tion (n ¼ 2), endoscopic maneuver of withdrawing the endoscope

managed with esophageal tube feedings. The mean duration of

from the duodenum back into the pylorus (n ¼ 1), biopsy of

hospitalization, including the day of the endoscopic procedure,

a gastric mass (n ¼ 1), and biopsy of the duodenum (n ¼ 1). The

was 8.3 days (range, 5–17 days).

specific endoscopic manipulation associated with the perforation was not recorded in one case.

Histopathological diagnoses were based on surgical biopsies (all cases), necropsy (cases 2 and 5), and immunohistochemistry

Following a diagnosis of pneumoperitoneum, immediate

(case 5) and included severe inflammatory bowel disease (case 1);

exploratory laparotomy and resection (cases 1–5) or repair (cases

small cell (low-grade) lymphoma (case 4); gastric B cell (high-grade

6 and 7) of the perforation was performed in all cases. Findings at

immunoblastic) lymphoma with transmural infiltration (case 5);

exploratory laparotomy were included in Table 3. The perfo-

chronic lymphoplasmacytic, eosinophilic and neutrophilic gastritis

rations were located in the duodenum (n ¼ 4), gastric fundus

(case no.6); severe inflammatory bowel disease with lymphocytic

(n ¼ 1), gastric body (n ¼ 1), and both gastric fundus and du-

portal hepatitis (case 7); multifocal duodenal ulcers with no

odenum (n ¼ 1). Additional abnormal findings at exploratory

underlying etiology apparent (case 2); and chronic pancreatitis

laparotomy included multifocal duodenal ulcers (n ¼ 2), a gastric

(case 3). In both cats diagnosed with severe inflammatory bowel

mass (n ¼ 1), evidence of chronic ulceration with gray fibrous

disease, the reviewing pathologist’s opinion was that small cell

tissue surrounding the duodenal perforation (n ¼ 3), focal peri-

lymphoma could not be definitively excluded but that histopa-

tonitis (n ¼ 3), a nodular pancreas (n ¼ 1), and a pancreatic mass

thology was most consistent with inflammatory bowel disease.

(n ¼ 1).

The final clinical diagnosis differed from the histopathological

All cases were treated as hospital inpatients. Case 5 was di-

diagnosis in three cases. Case 6 re-presented 5 mo after the original

agnosed with large cell lymphoma, based on impression smear

diagnosis for anorexia, weight loss, and lethargy, and was diag-

cytology of the gastric mass, and was euthanized intraoperatively

nosed with lymphoma based on cytology obtained via ultrasound-

due to the perceived poor prognosis. Postoperative treatments in

guided aspirate of a gastric mass. Case 2 was originally diagnosed

the five other cats and the dog included IV fluids (n ¼ 6), opioid

with multifocal duodenal ulcers with no underlying etiology ap-

pain medications (n ¼ 4), antibiotics (enrofloxacin in four cases,

parent from surgical biopsies, but was later diagnosed with gas-

ampicillin Na/sulbactam Naf in three cases, ampicilling in two

trinoma based on an increased serum gastrin concentration and

e

h

i

pancreatic carcinoma found at necropsy. The dog (case 3) was

in five cases. Case 6 was also treated with cyclophosphamide,

histologically diagnosed with chronic pancreatitis based on surgical

cases, and cefoxitin in one case), and an H2-receptor blocker

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Gastric fundus and duodenal perforations

peritoneum immediately following endoscopy. Abdominocentesis

Gastric fundus perforation Endoscopic visualization, abdominocentesis

Left lateral abdominal radiograph showing pneumo-

biopsies of a pancreatic mass visualized during exploratory laparotomy, but had a clinical diagnosis of gastrinoma based on markedly increased serum gastrin concentration. Final clinical diagnoses included lymphoma (cases 4–6), severe inflammatory bowel disease (cases 1 and 7), and gastrinoma (cases 2 and 3). Five cats and one dog (six of seven patients included in the study) survived the initial hospitalization and were discharged. Longterm follow-up data were available for five cats (Table 1).

NR

Endoscope maneuver

Gastric body mass with focal perforation Abdominocentesis, radiography Biopsy of gastric mass

Duodenal perforation Endoscopic visualization, abdominocentesis

Discussion Gastrointestinal perforation is a rare complication of routine diagnostic endoscopy. In the current study, the prevalence of perforation associated with endoscopy was 1.6% in cats and 0.1% in dogs. Gastrointestinal perforation has been reported infrequently veterinary endoscopy mentions a small cat that developed an 8 cm

Normal

Normal

in the veterinary literature. An article that reviews the history of NP

Biopsy of duodenum Irregular mucosa with nodules

Multifocal chronic duodenal ulcers, focal peritonitis, pancreatic mass Radiography Duodenal insufflation

Initial gastric insufflation NP

Thickened folds, hyperemic mucosa, multiple ulcers

Multifocal chronic duodenal ulcers, focal peritonitis, nodular pancreas

duodenal tear following forceful insertion of the endoscope. That cat recovered uneventfully with surgical repair, but no further

50:5 Sep/Oct 2014

lymphoma.13 Previous retrospective studies and review articles on NP, not performed; NR, not recorded; SI, small intestine.

NP

Thickened folds

doscopic biopsy was reported previously in a cat with intestinal

7

Thickened folds with nodular appearance NP 6

Gastric mass NP 5

Normal

Multiple nodules Gastric and SI wall thickened, gas in SI wall

Enlarged mesenteric lymph nodes 4

2

Duodenum thickened, corrugated

NP

details were provided.12 Pneumoperitoneum associated with en-

3

Chronic duodenal ulcer, focal peritonitis

Abdominocentesis

Exploratory Laparotomy Perforation Diagnosis

Abdominocentesis, radiography Duodenal insufflation

Perforation Occurrence Duodenal Endoscopy

Thickened folds, multifocal hemorrhages Irregular mucosa, thickened folds folds

Gastric Endoscopy Abdominal Ultrasound

Altered wall layering of SI, trace peritoneal effusion 1

Case

Results of Abdominal Ultrasound, Endoscopy, and Surgery in Six Cats and One Dog With Gastrointestinal Perforation Associated With Endoscopy

TABLE 3

326

FIGURE 1

endoscopy in cats and dogs allude to the large number of patients endoscoped without complication. In the first published review of veterinary endoscopy, 350 consecutive endoscopies (285 upper gastrointestinal exams and 66 colonoscopies) were performed without perforations.14 Two other studies in dogs reported .90 and .50 gastrointestinal endoscopies, respectively, without perforation as a complication.15,16 The most common site of perforation in the current study was the duodenum, but perforation also occurred in the gastric body and gastric fundus. Perforations during endoscopic procedures in the current study were associated with insertion and manipulation of the endoscope, insufflation, and biopsy. Colonic perforation did not occur in any animal in this study population.

Gastrointestinal Perforation with Endoscopy in Cats and Dogs

Risk analysis was not performed in the current study due to

The current study suggests cats may be at increased risk for

small case numbers, but the majority of endoscopy-associated

perforation associated with endoscopy compared with dogs and

perforations at the authors’ institution occurred in cats, even

that duodenal perforation is the most common location for

though more endoscopic exams were performed in dogs. Perfo-

perforation. Earlier studies may have a lower incidence of per-

ration occurred only in cats with severe infiltrative small intestinal

foration because of a lower number of duodenoscopies performed

disease (lymphoma, inflammatory bowel disease) and in cats and

and a lower number of cats undergoing endoscopy. A higher

dogs with preexisting gastrointestinal ulceration. Although the

number of duodenal exams were performed in the current study

cause was unknown, the authors speculated that unique charac-

compared with the published literature, and the previous retro-

teristics of feline anatomy, tissue tensile strength, and elasticity

spectives focused mainly on dogs.14–16 For example, in one series,

may have contributed to predisposition to perforation. It was also

esophagoscopy and gastroscopy were performed in all cases, but

possible that increased tissue friability contributed to iatrogenic

the duodenum was entered in only 6 cats and 30 dogs (13% of

perforation in four cats with underlying diffuse small intestinal

gastrointestinal exams).14 In a study of 90 dogs, esophagoscopy

infiltrative disease (inflammatory bowel disease, lymphoma).17–19

and gastroscopy were performed, but no duodenal exams were

Perforation of preexisting duodenal ulcers during endoscopy

performed.15 In another study of 50 dogs, the rate of successful

was identified in two cats and one dog, suggesting that duodenal

entry into the duodenum was higher, at an estimated 85%.16 Thus,

ulceration increases the risk for endoscopy-associated perforation.

the authors of this report suspect that patient factors were more

In each of those cases, the ulcers were determined to be preexisting

likely than operator factors to contribute to the perforation rate in

based on histopathological evidence of marked fibrosis around the

the current study. As previously discussed, the authors suspect

7

ulcer margins, indicating chronicity of the lesions (.3–5 days).

that diseased gastrointestinal tissue, especially in cats, may pre-

All cases with chronic duodenal ulceration developed pneumo-

dispose to perforation despite appropriate endoscopic technique.

peritoneum secondary to routine insufflation during endoscopy.

The lack of colonic perforations in the current study may be

Due to evidence of chronic fibrosis around the ulcer margins, as

related to anatomic characteristics of the colon, such as elasticity

well as surrounding focal peritonitis, the study authors speculated

and luminal diameter, and to the distribution of infiltrative diseases

that in each of those cases, the ulcer perforated prior to endoscopy

in cats. Inflammatory bowel disease and small cell lymphoma are

but was likely covered by an omental seal that became disrupted

common diagnoses in cats undergoing gastrointestinal endoscopy,

when the gastrointestinal tract was distended with air during

and both diseases more commonly affect the small intestine than

20

Animals with chronic ulcers in the

the colon.21,22 Iatrogenic perforations during colonoscopy have

current study either had underlying infiltrative intestinal disease

been rarely reported in cats and dogs. One author reported three

(severe inflammatory bowel disease) or gastrinoma, known risk

colonic perforations over a 17 yr period.23 Another study reported

endoscopic insufflation.

factors for gastroduodenal ulceration.

17–20

one perforation out of 355 flexible colonoscopic procedures.24

Compared with the published literature, this study revealed

That dog had a strictured region, and perforation occurred as the

a higher perforation rate. Previously cited risk factors for perfo-

endoscope was being passed in an orad direction without direct

ration during endoscopy include use of excessive force in ma-

visualization of the lumen. The authors state that the perforation

nipulating the scope around corners or use of poor biopsy

may have been avoided if less force and a smaller diameter

technique. Increased risk of perforation can also occur with deep

colonoscope had been used, underlying granulomatous colitis

gastric ulcers, especially if biopsies are taken from the center of an

may have also been a factor in the perforation.24

ulcer crater.2 It is feasible that the variable experience level of

Endoscopy-associated gastrointestinal perforation caused

trainee endoscopists at a teaching hospital such as the authors’

pneumoperitoneum to develop during the endoscopic procedure

may increase the perforation rates associated with endoscopic

in all seven cases reported herein. Gastrointestinal perforation was

manipulation and biopsy. However, all endoscopic procedures

diagnosed based on endoscopic visualization, abdominocentesis,

reported herein were supervised by experienced endoscopists, and

abdominal radiography, or a combination of these diagnostic

perforation also occurred in one case during manipulation by an

findings. These results suggest that endoscopic visualization of the

endoscopist with .20 yr experience. Furthermore, those original

perforation is less likely than detection of unexplained abdominal

retrospective studies on diagnostic endoscopy were published in

distention during the procedure that is unassociated with gastric

the 1970s and early 1980s, when endoscopes were less maneu-

distention and does not decrease with suctioning of air from the

verable and endoscopy was a new diagnostic technique in veter-

stomach. In this situation, abdominocentesis should be performed

inary gastroenterology.14–16

immediately to determine if free abdominal air is present, which

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327

indicates gastrointestinal perforation. Any cat or dog with pneumoperitoneum associated with endoscopy should be suspected of perforation. Overdistension of the stomach with air can occur during endoscopic insufflation, and can cause abdominal distension, which can mimic pneumoperitoneum. For that reason it is important to evacuate air from the stomach prior to abdominocentesis. In the current study, either abdominocentesis or abdominal radiographs were diagnostic for pneumoperitoneum in all cases evaluated. All animals in the current study had immediate surgery following gastrointestinal tract perforation, and six of the seven animals survived postoperatively. One cat was euthanized intraoperatively due to anticipated poor prognosis following

FOOTNOTES a GoLYTELY; Braintree Laboratories Inc., Braintree, MA b GIF-P140 Pediatric Video Gastroscope; Olympus America Inc., Center Valley, PA c GIF XQ140 Video Gastroscope; Olympus America Inc., Center Valley, PA d VQ 8143A Video Colonoscope; Olympus America Inc., Center Valley, PA e Baytril injectable solution 2.27%; Bayer Animal Health, Shawnee Mission, KS f Unasyn; Pfizer, New York, NY g Polyflex injectable suspension; Fort Dodge Animal Health, Fort Dodge, IA h Mefoxin; Merck & Co., Whitehouse Station, NJ i Famotidine 10 mg/mL; Bedford Laboratories, Bedford, OH

a cytologic diagnosis of gastric large cell lymphoma. The animals with evidence of chronic gastrointestinal perforation had no fatal endoscopic complications. Nevertheless, the cat with gastrinoma and chronic duodenal ulceration was euthanized 3 wk after hospital release due to recurrence of clinical signs, as reported by the owner. The dog with gastrinoma was lost to follow-up. The remaining four of six animals that survived to hospital release had either long-term survival .8 mo or later died of unrelated causes. Perforation associated with endoscopy has a good prognosis in the current study with a survival rate of 86% to hospital discharge and 57% to .8 mo. Reasons for the high survival rate to hospital discharge may include the prompt surgical correction and the supportive care that all seven cases received. Thus, risk factors for perforation at endoscopy may not necessarily be a contraindication to endoscopy, but prompt diagnosis and emergency surgery are essential if perforation occurs. Gastrointestinal perforation at endoscopy may have an excellent long-term prognosis when associated with benign or treatable underlying disease. Limitations of this study include the retrospective nature, the small number of cases identified, and the lack of standardization of diagnostics and treatment.

Conclusion Diagnostic endoscopy is associated with a low incidence of gastrointestinal perforation. With prompt recognition and surgical repair, gastrointestinal perforation associated with endoscopy has a good prognosis. Infiltrative small intestinal disease in cats and preexisting duodenal ulceration in both species may predispose to gastrointestinal perforation. Gastrointestinal endoscopy is not contraindicated in patients with a higher risk of endoscopic perforation as long as the patient can be treated with immediate surgical repair.

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JAAHA |

50:5 Sep/Oct 2014

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Gastrointestinal Perforation with Endoscopy in Cats and Dogs

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