Lipomas and SI surgical colic Flashcards
What are the most common surgical lesion in the SI?
Strangulations are the most common surgical lesion
Discuss SI surgical colic?
- The majority of SI causes of colic require surgery
- palpable SI distension is an indication for surgery alone
- Remember SI should not be palpable in the normal horse
The small intestine is involved in the rapid transfer of ingesta towards the caecum anything that obstructs that ingesta will cause?
fluid to back up
Obstructions may be:
- physical: the most common cause
- neurological e.g. equine grass sickness
- vascular e.g. non strangulating infarction due to cyathostomes
What kinds of intestinal obstruction are there?
- Complete or partial
- Simple (wrapped around not occlude BS) or strangulating (occluding BS)
What is a simple obstruction?
Simple Obstruction
partial or complete obstruction of the lumen but, initially, no interference with the blood supply.
What is a strangulating obstruction?
Strangulating Obstruction
- blood supply to intestine is obstructed from the outset
- Won’t resolve even if you remove the obstruction
Define sequelae?
A sequela usually used in the plural, sequelae is a pathological condition resulting from a disease, injury, therapy, or other trauma. Typically, a sequela is a chroniccondition that is a complication which follows a more acute condition. It is different from, but is a consequence of, the first condition. Timewise, a sequela contrasts with a late effect, where there is a period, sometimes as long as several decades, between the resolution of the initial condition and the appearance of the late effect.
Discuss how pathological sequelae occur in simple obstruction of SI?
Simple obstruction of the small intestine
- Complete obstruction leads to sequestration of fluid oral to the obstruction in the intestine and eventually the stomach.
- >100 litres per day of fluid (saliva 10-15litres, gastric/intestinal/pancreatic secretions) pass through the small intestine
- If you obstruct anywhere along this it is no longer absorbed in hindgut. Moment you obstruct the SI you start a timer where horse starts loosing 4litres an hour of circulating volume
Depending on where obstruction occurs along SI depends how long it will take for stomach to fill up .
If we obstruct at ileum will take longer for stomach to fill as can fill SI space first
If we obstruct nearer stomach will fill much quicker
Depending where the lesion is is very important as more rostral lesion stomach will fill quicker and may rupture more acutely
Show this in a diagram?
What does a sequestration result in?
This sequestration results in
- reduction in circulating blood volume
- leading to increase in HR and PCV
- leading to hypovolaemic shock.
Progressive increase in intraluminal pressure causes
- hydrostatic loss of protein through the gut wall
- impaired blood supply leading to ischaemia
What are the causes of simple obstructions?
There are several causes of simple obstructions
- Adhesions (surgical, trauma, parasites)
- Neoplasia (leiomyomas)
- Abscesses
Discuss types of strangulation?
Depending upon the degree of compression of the intestinal blood supply, the strangulating obstruction is described as:
- Venous
- Arterial
Blood going in and not going out = Venous
Gut wall thickness does not change as no congestion but onset of clinical signs more rapid= Arterial
Discuss venous strangulation further?
- Arterial supply unaffected initially
- Venous occlusion leads to rapid mural congestion
- Intestine becomes dark red and oedematous
- Red blood cells present in all layers and quickly diapedese into the peritoneal cavity
- A sample of peritoneal fluid at this point would show RBCs a serosanguinous sample
Discuss venous strangulation further?
Increase in mural thickness and luminal distension increases pressure against the constricting structure
- e.g. the hernial ring, lipoma stalk, epiploic foramen
Eventually the pressure applied to the vessels exceeds the arterial pressure
Once the artery is occluded no further blood enters the strangulated segment
Discuss damage to the mucosa caused by venous strangulation?
The mucosa receives 80% of the intestinal blood supply
Therefore is most susceptible to damage after loss of BS
- begins to become necrotic within 1 hour
- necrosis commences at the apices of the villi
- extends to the crypts by approximately 4 hours
Discuss arterial strangulation?
- The pressure on the intestinal vessels from the outset obstructs both the veins and arteries
- Intestine wall does not increase in thickness
- Rapidly developing ischaemic changes result in the wall becoming paper-thin
- Very easy to rupture it therefore
- Shock develops very rapidly in this situation
Look at this arterial strangulation?
Discuss wound infections post colic surgery?
Preceded by massive oedema
- Management
- Regular cleaning, remove encrustation
- Remove skin suture
Usually resolves in 7-10 days
Discuss incisional hernias post colic surgery?
Discuss the complication of jugular thrombosis?
Management
- remove catheter (conservative)
- (hot-pack)
- +/-DMSO
Risk factors for it:
- PCV on admission
- Heart rate > 60 bpm
Discuss ileal impaction?
Thickening and hypertrophy of ileum
- Physical obstruction of ingesta
- Typically easily resolved
Associated with Anoplocephala burden
- Useful to perform ELISA and treat accordingly
Tapeworms also associated with ilealand caecal intussusceptions
Discuss idiopathic focal eosinophillic enteritis?
Very difficult to distinguish from SI strangulation
- present with often very elevated PCV
- severe pain
- reflux
- possibly some differences may yet be determined on peritoneal fluid analysis
Discuss Epiploic foramen entrapment?
Epiploic foramen:
- caudate lobe of the liver
- the hepatic portal vein
- the gastropancreatic fold
Epiploic refers to the greater omentum –in Greek epipleo means to float upon –the omentum floats upon the abdominal contents and peristalsis exacerbates the milking into the foramen
Discuss pendunculated lipomas?
- A pedunculated lipoma is a benign fatty mass originating from the mesentery and is the most-common intra-abdominal tumour of the geriatric horse. A lipoma may lead to obstruction or strangulation of the small intestine, occasionally affecting the small colon. The tumours are seen in all types of horses but mostly in ponies and cob-types. Geldings appear to be at a higher risk compared to mares and stallions, suggesting a possible endocrine aetiology. It is unclear whether the risk of lipoma formation is associated with body condition.
- Lipomas are often multiple in number and attach to the mesentery of the intestine via a stalk or pedicle of varying length. The stalk becomes wrapped around a segment of small intestine, causing compression of the intestinal lumen and corresponding mesenteric vessels. Longer stalks are associated with more severe and complete intestinal strangulation. More rarely, broad-based tumours arising close to the intestine can occur causing periodic restriction of ingesta without intestinal compromise. Lipomas may also be incidental findings at post mortem or exploratory laparotomy.
