Bowel Obstruction. Donald E Thrall, DVM, PhD Ross University School of Veterinary Medicine Basseterre, St. Kitts

Transcription

1 Bowel Obstruction Donald E Thrall, DVM, PhD Ross University School of Veterinary Medicine Basseterre, St. Kitts

2 Bowel Obstruction Considered commonly Important for patient that we be correct Seasoned radiologists sometimes wrong Many times patient not obstructed in my practice anyway

3 Radiographic technique No preparation advised Views LL, RL, VD Take advantage of gas as contrast medium Technique Analog: Hi mas, low kvp Maximizes contrast Digital: Technique less critical

4 Checklist Learn normal anatomy Are there enlarged bowel segments? Roughly height of L2 in dogs 2x height of central part of L4 in cats, or 12mm These are guidelines! Is it colon? Distribution of enlarged segments Are there normal segments too? Contents? Gas and solids Gravel sign Bowel gas pattern? Crescents Commas Paisley Wall thickness Free peritoneal gas?

5 Canine

6 Feline

7 Bowel Obstruction Hallmark sign is enlarged bowel Is the enlarged bowel small intestine? Is the problem due to mechanical vs. paralytic bowel obstruction?

8 Mechanical vs. Paralytic Ileus Mechanical Usually two populations of bowel Normal and Enlarged Enlargement usually greater in mechanical Leads to stacking Usually fluid and gas in lumen Sometimes foreign material in mechanical Cloth Gravel sign Often just gas in paralytic ileus These are only guidelines and there is overlap

9 PARALYTIC ILEUS (peritonitis) A167198

10 A PARALYTIC ILEUS (endotoxemia)

11 Two Populations The presence of some small bowel segments that are normal in diameter and others that are significantly larger 2-3X A173605

12 Opaque ingested particulate matter collecting proximal to obstruction More common in chronic partial obstruction Overall, not common Just something to look for Gravel Sign

13 MECHANICAL: foreign material in S.I. I

14 MECHANICAL: foreign material I

15 MECHANICAL: stacking Stacking A85613

16 Cat, 1y Vomiting for one week Treated symptomatically 2 sets of radiographs declared normal except for fecal accumulation Emergency radiographs declared no evidence of obstruction 91495

17 0.5 Obstructed Cat Colon 1.5 What is this? Contents Normal bowel Enlarged bowel segment Not colon Gas and solids Two Populations

18 Learning Points Problem started when small bowel misidentified as colon Small bowel can have fecal-like contents Anatomy was misinterpreted

19 German shepherd, 8y 3 day history of anorexia One day history of vomiting Taken to rdvm Referring radiograph report: Foreign material (bone) and intestines seemed displaced Given fluids and sent home Vomiting continued; went back to rdvm Referred Dog is indiscriminant eater (paper, cans) Mostly an indoor dog

20 R

21 Two Populations Foreign Material in S.I.

22 Staffordshire, 2y Began vomiting 4d ago after shredding and eating a sock Became anorexic the following day Currently vomiting approximately 4 to 5 times daily Evaluated by local veterinarian 1d ago and no diagnostics were performed Now has intractable vomiting

23

24 Plication Crescents

25 Plication and crescents Courtesy Dr. W.R.Widmer

26 Some patients where obstruction was considered

27 Labrador retriever, 7y Acute anorexia and vomiting for one day Vomited brown fluid on way to ER Hypovolemic shock Soft/pliable abdomen Mildly resents palpation No overt organomegaly or masses

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29 No obstruction seen with US WOW!!! Septic effusion on peritoneal tap Surgery Jejunal perforation Foreign material but no obstruction Died Learning points None Would call obstruction again

30 Cat, 15y Progressive weight loss over 3 years Seems to vomit when fed treats Lethargy Abdomen not painful

31 113669

32 No obstruction apparent with sonography Biopsy dx: Lymphoplasmocytic and eosinophilic enteritis Learning points Chronic history Intermittent vomiting No abdominal pain No bowel fluid

33 What to do if you re confused

34 Get Both L and R lateral R Jamie s case

35 L L

36 Pneumocolon

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38 R Initial Radiographs Obstruction can t be sure. L Re-Radiograph After 4-24 hrs. M152609

39 R L 24h Later Signs have not abated O refused US; took dog to rdvm for xlap; nylabone fragment

40 Obstruction??? M No 24 hrs

41 Upper GI Examination Rarely done or done well in practice Not enough barium Wrong type of barium Stopping too soon Anti-motility drugs on board

42 Ultrasound

43 Teleradiology