NZ Bowel Obstruction · PDF file Mechanical vs. Paralytic Ileus Mechanical Usually two...

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Transcript of NZ Bowel Obstruction · PDF file Mechanical vs. Paralytic Ileus Mechanical Usually two...

  • Bowel Obstruction

    Donald E Thrall, DVM, PhD

    Ross University

    School of Veterinary Medicine

    Basseterre, St. Kitts

  • Bowel Obstruction

    Considered commonly

    Important for patient that we be

    correct

     Seasoned radiologists sometimes

    wrong

    Many times patient not

    obstructed…in my practice anyway

  • 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

  • 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?

  • Canine

  • Feline

  • Bowel Obstruction

    Hallmark sign is enlarged bowel

     Is the enlarged bowel small intestine?

     Is the problem due to mechanical vs.

    paralytic bowel obstruction?

  • 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

  • PARALYTIC ILEUS (peritonitis)

    A167198

  • A121444

    PARALYTIC ILEUS (endotoxemia)

  • Two Populations  The presence of some small bowel segments that are normal in diameter and

    others that are significantly larger…2-3X

    A173605

  • Gravel Sign  Opaque ingested particulate matter

    collecting proximal

    to obstruction

     More common

    in chronic

    partial

    obstruction

     Overall, not

    common

     Just something

    to look for

  • I1031690

    MECHANICAL: foreign material in S.I.

  • I1031690

    MECHANICAL: foreign material

  • A85613

    MECHANICAL: stacking Stacking

  • 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

  • •Enlarged bowel segment

    1.5

    0.5

    Colon

    •Not colon

    Contents

    •Gas and solids

    What is this?

    Normal bowel •Two Populations

    Obstructed Cat

  • Learning Points

    Problem started when small bowel

    misidentified as colon

     Small bowel can have fecal-like contents

     Anatomy was misinterpreted

  • 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

    112554

  • R

  • • Two

    Populations

    • Foreign

    Material in

    S.I.

  • 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

    112801

  • • Plication

    • Crescents

  • • Plication and crescents

    Courtesy Dr. W.R.Widmer

  • Some patients

    where obstruction

    was considered

  • 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

    113468

  •  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

  • Cat, 15y

    Progressive weight loss over

    3 years

    Seems to vomit when fed

    treats

    Lethargy

    Abdomen not painful

  • 113669

  •  No obstruction apparent with

    sonography

     Biopsy dx: Lymphoplasmocytic and

    eosinophilic enteritis

     Learning points

     Chronic history

     Intermittent vomiting

     No abdominal pain

     No bowel fluid

  • What to do if

    you’re confused

  • Get Both L and R lateral

    Jamie’s case

    R

  • L

    L

  • Pneumocolon

  • Re-Radiograph

    After 4-24 hrs.

    M152609

    R

    L

    Initial Radiographs

    Obstruction…can’t be sure.

  • L

    R

    24h Later

    Signs have not abated

    O refused US; took dog

    to rDVM for xlap;

    nylabone fragment

  • Obstruction???

    24 hrs

    No M158414

  • 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

  • Ultrasound

  • Teleradiology