Mudasir BashirDIVISION OF SURGERYAND RADIOLOGY-IVRI

Blockage of aborad flow of intestinal contents (chyle).

Classification (etiological)

Intestinal Obstruction

Mechanical Functional

Intraluminal(foreign bodies)

Intramural(tumors and polyps)

Intussusception Volvulus

Hypodynamic state (ileus) Strangulation/ incarceration

Congenital

Clinical Signs

Depend upon :-1. Location

More orad –more acute signs (secretion- absorption)

More aborad – mild, non specific and chronic signs

Animals with more orad obstruction respond better to fluid and electrolyte therapy.

Obstruction in duodenum and proximal jejeunum-

* Acute vomition especially post-prandial.

* Praying posture Obstruction in mid and caudal jejeunum

– *mild, non specific and chronic signs. *Letharginess, anorexia, oligodipsia

and scanty stool Intussusception – Bloody, fetid smelling

feces

2. Severity Complete – significant and early signs Partial – few or no signs (in later

stages)

3. Duration Long standing obstruction – severe

signs Early obstruction – few non specific

signs.

General signs

Depression Lack of responsiveness Halitosis Dehydration with dry mucosa Moaning Painful abdomen (treading and stretching

out, kicking at belly, lying on ground) Retching Bilateral lower abdominal distention at later

stages

Pathogenesis Obstruction Bowel distention (increased secretion

reduced absorption, hypomotility)

Gas production, lack of absorption

Progressive distention, fluid accumulation, emesis

Systemic dehydration

Reduced venous return

Poor tissue perfusion

Obstruction of venules and lymphatics in bowel wall

Edema of bowel wall

Ischaemia of bowel wall

Necrosis of bowel wall

Enterotoxemia

Death

Rupture of bowel wall

Peritonitis

Sepsis and septic shock sepsis with septic shock occurs as a result of host

response to bacterial signal molecules-endotoxin of gram negative,exotoxins of peptidoglycan,lipotechoic acid,etc.

Toll-like receptors –essential in innate recognition of microbial signal molecules in triggering acquired immunity.

Ten types of TLRs have been found.TLR-4 is essential for lps signelling.

Biological effects of LPS-induced host immunolgical responses are-

Increased vascular permeability

Extensive microvascular thrombosis disseminated intravascular coagulation.

Vasodilatation. Decreased myocardial contractility. Fever.

No organ is left by sepsis-multiple organ dysfunction syndrome.

Following are the effects of sepsis and septic shock on different organs:-

Lung-increased alveolar permeability---increased pulmonary fluid----decreased oxygen exchange.

GIT-haemorrhagic necrosis of mucosa due to ischaemia.

Kidney-acute tubular necrosis---acute renal failure.

Liver-stasis of bile,focal necrosis and jaundice. Endocrine and metabolic effects-increased

levels of cortisol,catecholamines and glucagon—increased proteolysis,lipolysis and gluconeogenesis.

Heart-decreased myocardial function--increased

Systolic and diastolic ventricular volume with a decreased ejection fraction.

strangulation obstruction Strangulation—intestinal wall integrity

disturbance—ischaemia/haemorrhagic intestinal wall infarction—anoxia and necrosis of bowell wall—bacterial growth and multiplication{bacteroids,clostridium,coliforms}—penetration of bacterial products into peritonium—through portal lymphatic—blood stream—septic shock.

Diagnosis

History Clinical findings Physical examination – abdominal

palpation Imaging

Radiography Ultrasonography Laparoscopy

Measurement of diameters Laboratory examination

1. Radiography a) Plain Dilated and gas filled loops of bowel Identifiable foreign body Clumping of bowel + intestinal gas

pattern resembling rows of tear drops shaped lucencies arranged in palisades = linear foreign body

b) Contrast radiography May take 6-24 hrs

Barium (insoluble contrast agent) Adv. - more details - soothing effect on irritated bowel Disadv. – very irritating to peritoneum if spilled

out Diatrizoate meglumine (soluble contrast agent) Adv. – less likely to cause peritonitis Disadv. – poorer details - increases dehydration (hypertonic).

Linear foreign body

2. Ultrasonography More rapid method More chances of false -ve and false +ve Technique of choice for intussusception

3. Laparoscopy

4. Measurement of diameters Max. SI diameter:L5body ht. At narrowest

point = 1.6 (normally) >2 = obstruction

5. Laboratory findings (abdominal fluid)• Increased total protein (>2.5 g/dl)• Increased cell count (> 10000 cell/cmm.)

Intussusception-Radiographic trident appearance

Transverse Longitudinal

Laparoscopy (Intestinal polyps)

Foreign bodies Most common cause of intestinal

obstruction in animals.1. Space occupying

Round smooth Complete obstruction Trail of distended bowel (aborad

propulsion) Pressure necrosis

Sharp edged Partial obstruction Perforates bowel wall

2. Linear foreign body Thread, nylon stockings, rope, string,

carpet etc. Most frequent in cats One end – tongue base, pharynx, pylorus Other end – carried to intestine through

peristalsis Mesenteric side – perforations Oral examination – most important Abdominal examination – pain, pleating

and clumping of intestine Radiography Rx - surgical emergency - enterotomy (multiple or single)

Tumors Mostly malignant (thoracic radiography

and hepatic ultrasonography).

1. Adenocarcinoma bowel stricture Most common – distal jejunum and

ileum Treatment unrewarding

2. Leiomyoma/ Leiomyosarcoma Impinge on bowel lumen Leiomyoma- good prognosis Leiomyosarcoma- grave prognosis

3. Lymphosarcoma Protein losing enteropathy – most

common Chemotherapy is treatment of choice

4. Adenoma Also known as polyps Partial obstruction Irritation - intussussception

Polyps

Intestinal tumors

Intussusception Invagination or telescopy of intestines Intussusceptum – intussuscipiens Hypermotility (irritataed bowel) Partial obstruction – complete obstruction Ileo-caeco-colic junction – most common

site Common in young pups

Rx Laparotomy – release of invagination with

or without intestinal resection and anastomosis.

Intussusception ant ileo-caeco-colic junction

Volvulus

Twisting of intestine on its mesenteric axis

Susceptibility – GSD – dogs with GSD blood – other

breeds. Radiograph – massive dilation of

multiple loops of bowel in stellate pattern originating from a central focus.

Prognosis – very grave.

Intestinal volvulus

Intestinal volvulus

Congenital defects

Atresia of intestinal segments Signs visible in neonatal life Intestinal resection and anastomosis -

only cure.

Ileus / Pseudo- obstruction

Def. – ineffective aborad intestinal propulsion Occurs – (a) after surgery (b) secondary to diseases (uremia, peritonitis, pancreatitis) Mainly due to electrolyte disturbances Usually transient Rx – (a) prokinetic drugs (b) correction of electrolyte disturbance (c) correction of underlying disease

Strangulation / Incarceration

Entrapment of intestines in traumatic wall hernia, omental tears, congenital hernia, mesenteric rents, volvulus and intussusception.

Compression of intestinal veins – inhibition of arterial flow – mucosal degeneration – endotoxemic shock and peritonitis (perforation)

Stabilize the animal – enterotomy / anastomosis

Prognosis - grave

Causes of strangulation

Appearance of strangulated intestines in a horse suffering from colic

Intestinal Surgery GENERAL PRINCIPLES

1. Maintenance of fluid and electrolyte imbalance (hypokalemia, hypochloremia, hyponatremia and metabolic acidosis)

2. Antibiotic prophylaxis (contaminated or clean contaminated surgery)

3. Assessment of intestinal viability4. Choice of suture material Monofilament synthetic absorbable

(polydioxanone, polyglyconate)

5. Choice of suture pattern Submucosa (incorporation)

A. * Single layer – preferred * Double layered – Avascular necrosis of

inverted cuff of tissues - Narrowing of lumen.inadequate submucosal apposition.

.

B. * Apposition – preferred method * Eversion - adhesions * Inversion – reduced intestinal lumen

Interrupted single layered serosubmucosal suture pattern – gold standard

6. Suture line enforcement Prevention of leakage Revascularization A. Omental wrappingB. Serosal patching (surgical parachute)

Enterotomy and Anastomosis