Bovine abdominal surgery 4 Flashcards
small intestinal lesions
* Right flank approach
- standing vs GA?
- Standing vs GA depends on degree of pain cow is in & whether able to stand
- In addition, intra-operative pain from manipulation of mesentery may cause cow to go down
- If doing recumbent, GA is preferable to sedation to prevent aspiration pneumonia
Small intestinal accidents
- types?
- is it easy to ddx pre-operatively?
o Non strangulating (simple and functional) vs strangulating
> Simple obstruction: enterolith or accumulation of hair and debris
> Functional: ileus, often associated with inflammation and infection
o Difficult to ddx an obstruction pre-operatively vs functional disorder eg enteritis
Clinical signs of strangulating obstruction
- what parts of intestines affected? consequence?
o Commonly distal jejunum and ileum affected, so fluid sequestrates in proximal intestine
o Results in dehydration, and because outflow of abomasal fluid rich in HCl is impeded,
hypochloremic metabolic alkalosis normally ensues
* Also hypokalemic from lack of dietary intake
Clinical signs of strangulating obstruction
- pain and signs?
- tension on what structure?
- bowel / abdominal distension?
- Severe abdominal pain – stretching out, treading, kicking at abdomen, recumbency
- Tension on mesentery
- Bowel distension proximal to lesion, low and bilateral abdominal distension, succussion shows fluid wave
Clinical signs of strangulating obstruction
- fecal signs? what to measure in abdominal fluid?
- important diagnostic exams?
o Scant manure, maybe melena from sloughing of devitalized intestine
o Abdominal fluid analysis if can be obtained – measure cells and lactate
* Ultrasound and rectal examination
Duodenal outflow obstruction
- causes? does presentation differ with cause?
- Foreign bodies, intraluminal or extraluminal masses, adhesions in sigmoid flexure, duodenal sigmoid flexure volvulus
- Similiarities between cases regardless of cause
Duodenal outflow obstruction
- common clinical signs
o Common clinical signs: anorexia, decreased milk and fecal production, tachycardia, varying degrees of depression, decreased ruminal contractions
o Also, abdominal distension, colic, scant feces, ruminal distension
Duodenal outflow obstruction
- fluid & electrolyte disturbances?
- More severe fluid & electrolyte disturbances than cows with abomasal volvulus
- Dehydration, hyponatremia, hypokalemia, hypochloremia, hyperphosphatemia, hyperglycemia, hyperproteinemia, metabolic alkalosis, elevated anion gap
Duodenal outflow obstruction
- characteristic distension pattern? effect on abomasum?
- Characteristic is distension of the cranial portion of the duodenum with a flaccid descending duodenum
- Abomasum may be dilated and dorsally displaced
Duodenal outflow obstruction
- treatment
o Treatment: removal of any obstruction
o Duodenal bypass if necessary – cranial part anastomosed to descending duodenum in side to side manner
Duodenal outflow obstruction
- should be considered if what type of DA? what should we do?
o Should be considered if RDA found without volvulus
> Reexplore cow for definitive treatment if the signs were treated with omentopexy and fluid and electrolyte disturbances progress
Intussusception
- wut dis
- anatomic location where most common
- untreated cattle outcome?
- Invagination of a portion of intestine into the lumen of adjacent bowel
- Drags mesentery and blood vessels with it, creating strangulating obstruction
- Most commonly small intestinal, also cecocolic or ileocolic
- Untreated cattle die 5-8 days after onset of clinical signs
Intussusception clinical signs, U/S signs
- Cattle exhibit mild to moderate pain, anorexic, lethargic, tachycardic, melena
- Rectal and ultrasound show distended small intestine
Intussusception - surgical approach - how to find location
- Right paralumbar fossa celiotomy, more thorough if GA
- Cecum identified, exteriorized & traced to ileum, leads to jejunum
Intussusception
- how to correct surgically? prognosis?
- Intussusceptum identified but unsafe to reduce
- Resection and anastomosis: one layer inverting
continuous pattern, such as Lembert - End – to – end anastomosis
> Ligate vessels close to bowel
> No serosa at mesentery Þ rotate bowel 30o
> 2.0 absorbable suture
> Close mesenteric defect
> Lavage - Post op survival of 40%
Intestinal volvulus
- whats this? where is common?
- Twisting of a segment of bowel upon itself
- Long mesentery of distal jejunum and ileum makes this more prone to volvulus
Intestinal volvulus
- surgical approach? position? how do we find it? prognosis?
- Right paralumbar fossa celiotomy
- Standing or recumbent
- In situ feel for tight bands or masses
- Proximal intestine gas distended
- Bowel is untwisted & brought to incision
- Run hand straight up to root of mesentery
- Prognosis depends on duration of obstruction and viability of intestine
- Resection and anastomosis if necessary
Torsion of the mesenteric root
- what is this? signs? what should we do?
- Volvulus of the entire small intestinal tract
- Profound pain
- Bilateral abdominal distension, tachycardic, and tachypneic
- Tight bands and distended viscera on palpation per rectum
- Prompt surgical intervention
Torsion of the mesenteric root
- how to correct? surgical position? careful about what during surgery? prognosis?
- By following the mesenteric root the twist is identified and corrected
- Standing or lateral recumbency – surgeons preference
- Untwisting such a large amount of intestine can lead to endotoxic shock
- Rapid progression of signs makes the prognosis grave
Herniation
- common tissues involved? clinical signs? how to correct?
- Herniation – omental bursa, mesenteric rents, persistent entrapping umbilical structures, epiploic foramen entrapment, scrotum
- Clinical signs similar to those of cow with intussusception with moderate abdominal pain
- Right paralumbar fossa celiotomy – if entrapping band, should be transected blindly with scissors
Jejunal hemorrhage syndrome
- another name
- when do we see it?
- sometimes what serious outcome?
- consistnet finding?
- case fatality?
o Also called hemorrhagic bowel syndrome
o Presents in early lactation
o Sometimes acute death
o Consistent finding of intraluminal blood clot
o Case fatality rate of 85%
Jejunal hemorrhage syndrome
- can cows be saved?
- treatments?
- what makes prognosis worse?
- likely pathogen?
o Early diagnosis and immediate intervention may save some cows
o Medical therapy, blood transfusion, fluid therapy, anti-inflammatory and analgesic,
antimicrobials
o Manual clot breakdown in surgery
o Multiple affected segments worsens prognosis o Likely from Clostridium perfringens Type A
Cecal Dilation & Volvulus
- etiology
- Unclear ~ abomasal problem
- Decreased exercise
- High concentrate/low fiber rations
<><>
o Causes are not clear: hypocalcemia, diets rich in starch, abrupt increase in concentration of volatile fatty acids
cecal dilation vs dislocation vs torsion vs volvulus
o Cecal dilation is distension of cecum without a twist
o Rotation along its long axis is a torsion, rotation in the area of the ileocecocolic junction is a volvulus. The term dislocation encompasses torsion, volvulus, twist or retroflexion
what is cecal volvulus?
Volvulus: cecum + proximal & spiral loops of ascending colon > twist
Cecal Torsion - what is this, where does it occur?
- Rotation along the axis of the cecum > occurs right at the ileocecal fold
cecal dilation clinical signs
- Mild signs:
> decreased appetite,
> decreased milk production,
> decreased fecal output,
> ± abdominal distension -
Ping in R paralumbar fossa
o More caudal in abdomen than RDA - Gas-distended tubular viscus in pelvis (apex)!
- Ketonuria, chronic case > metabolic alkalosis
- Clinical signs – Cecal Volvulus
More severe signs
* Anorexia & sudden drop in milk
production
* abdominal pain & distention & no feces
* increased HR, dehydration
* ping in R paralumbar fossa & fluid on succussion
Cecal Dilation & Volvulus
- what do we feel on palpation per rectum?
- SI distention
- Body of cecum palpated, apex rotated forward
o On rectal examination, body of cecum not apex can be palpated
Cecal Dilation & Volvulus
- blood work?
- Hemoconcentration
- Cl down, K down, metabolic alkalosis > metabolic acidosis > duodenal obstruction or back-up of abomasal contents
cecal dilation medical treatment
- correction of ketosis & electrolytes imbalance
- diet modification
- increase exercise
- parasympatomimetics
cecal volvulus medical treatment
- IV fluids prior SX
surgical treatment for Cecal Dilation & Volvulus? when apropriate? what approach?
- For dilation if not responsive to medical Tx
- A must for volvulus/torsion
- R-flank celiotomy
> cecal decompression
=> Gas: needle
=> Fluid: typhlotomy
Cecal Dilation & Volvulus
- typhlotomy - how to perform?
o Right flank approach, ideally standing
o If simply dilated, cecal apex found in pelvic inlet
o Apex directed cranially if retroflexed
o Dislocations are carefully corrected intraabdominally
Cecum and PLAC are exteriorised
May need to do typhlotomy prior to untwisting
* Apex isolated, and typhlotomy performed at most ventral aspect
* Lavaged with saline and closed with double inverting 2-0 absorbale suture pattern
Cecum returned to abdomen, and if refilled, a second typhlotomy is performed
when is typhlotomy indicated?
- Recurrent dilation
- Cecum remains compromised
- Cecal infarction
- Ileocecocolic junction needs to be unaffected!
<><>
o Medical treatment if cecal dilation if normal or mildly affected general condition
o If unsuccessful after 24 h, or condition is more profound, typhlotomy is indicated
Cecal Dilation & Volvulus: Cecal amputation only indicated if
if recurrence or devitalization of cecal wall
Typhlotomy post op care?
o Post-operatively, motility agents, such as bethanecol or neostigmine
o Antimicrobials due to contamination
o Analgesics
o IV or oral rehydration
o Restricted diet for 48 hours
typhlotomy complications? recurrence? long term survival?
o Complications: septic peritonitis and persistent motility disorder
o Recurrence of 10-20%
o Long term survival of 70%
Amputation of cecum - when is it appropriate? how to perform?
o If recurrence or devitalization of cecal wall
o Cecum exteriorised and emptied via typhlotomy
o Ileocecocolic ligament is blocked with lidocaine
o Cecal branches of cecal artery and vein are ligated close to attachment of ligament to cecum to preserve blood supply to ileum
o Intestinal clamps placed across cecum prior to transection
o Closure with 2 inverting seromuscular suture patterns with 2-0 absorbable suture material
o Complete typhlectomy has been reported with ileocolic anastomosis
