Flashcards
GI surgery 2
Cards in this deck (41)
- 1What is the issue with the SI?Has a long mesentery and so can get into places it shouldn't be
- 2What % of the SI can you exteriorise?~90%
(can't exteriorise the front or junction into the caecum) - 3Which of the 3 intestinal obstructions are surgical conditions?- Functional
- Strngulating - 4What is the prognosis with SI obstructions?- Simple obstructions – usually good once ressolved
- Strangulating lesions involving resection/ anastomosis involve increased risks of:
* contamination, and peritonitis
* endotoxic shock
* ileus
* Post-operative adhesions
- Prognosis of survival to 1 year is approx. 50% - 5What occurs to the area of the SI that is strangulated?Strangulated section goes maroon to purple to black as blood supply compromised. Mucosa becomes permeable to endotoxin which leaks into peritoneal cavity and circulation
- 6What is the effect to tissue either side of the SI strangulation?- Proximal to this in effect a simple obstruction with just distention as gas and fluid cannot pass the obstruction.
- Distention will however cause ileus if protracted which can be hard to reverse
- Distal to obstruction intestine will appear relatively normal - 7What are some specific conditions related to SI strangulating obstructions?1. Pedunculated lipomas
2. Herniation – epiploic foramen,
- inguinal,
- mesenteric defects
3. Intussusceptions - 8What is the most common cause of SI obstructions?Pedunculated lipoma
- 9How and why do pedunculated lipomas occur?- Small deposits of fat in mesentery
- These grow and stretch the mesentery
- Bigger is like a ball on a piece of string
- Wrap around the intestines - 10What are general features of pedunculated lipomas?- Classically occur in older fat ponies but can be seen in any adult horse
- Commonest cause of strangulating obstruction of SI in our clinic
- Develop as small fatty deposits in the mesentery of the SI which gradually grow into round lipomas
- As it grows the lipoma stretches the mesentery locally into a “string” with the lipoma constituting a ball on the end of it
- This may wrap around a loop of small intestine strangulating it and causing acute colic which requires surgical intervention
- Resection and anastomosis of the strangulated section of intestine is required in most cases - 11What are common complications of pedunculated lipomas?- Post-operative ileus is a common short term complication which may be challenging to resolve and may lead to euthanasia
- Adhesions and/or further strangulation by other lipomas often result in further colic and euthanasia in the next 6-18 months - 12What are the 2 types of inguinal hernias?- Congenital
- Acquired - 13What are features of congenital hernias?- Congenital herniation of small intestine through the inguinal canal into the vaginal tunic (so-called ‘indirect’ inguinal or scrotal hernia) is often observed in young colts and the contents are usually reducible.
- Intestinal obstruction is rare and the condition usually resolves spontaneously during the first few months of life.
- Occasionally intestine may herniate through a tear in the vaginal tunic distal to the vaginal ring or through a rent in the peritoneum and transverse fascia, adjacent to the vaginal ring (so-called ‘direct’ inguinal or scrotal hernia).
- The intestine lies in the subcutaneous space of the scrotum and prepuce, resulting in severe oedematous swelling and skin necrosis; although strangulation is uncommon this condition represents a surgical emergency - 14What are features of acquired inguinal hernias?- Acquired inguinal hernias in adult stallions usually result in strangulation obstructions and represent an important differential diagnosis for acute colic in entire males.
- Usually a small segment (10–15 cm) of ileum or jejunum is incarcerated and the testicle becomes enlarged and cold due to compression of the testicular vessels.
- Prompt surgical correction with or without resection of the affected intestine is indicated, and castration is usually performed. - 15When is it common to get inguinal hernias?- Occurs in stallions often after exercise or mating – intestine in scrotum
- As a complication of open castration – intestine protruding from scrotal incision - 16How can you diagnose inguinal hernias?- In spontaneous cases in stallions diagnosis by palpation of scrotum and rectal palpation of inguinal ring
- Asymmetry of testes –afflicted side distended, painful.
- Ultrasonography can distinguish entrapped intestine from testicle - 17What do "internal" hernias result from?Internal (intra-abdominal) hernias result from the protrusion of an abdominal organ or viscus through an aperture in the peritoneum or mesentery.
- 18What are intraperitoneal openings in the horse?From an anatomical perspective, intraperitoneal openings may be classified as normal or abnormal. Normal intra-abdominal apertures in the horse include the epiploic foramen and the nephrosplenic space
- 19What are included in abnormal or pathological openings?Defects or tears in the:
- Mesentery
- Greater omentum
- Intra-abdominal ligaments - 20Give 2 developmental abnormalities.1. Mesodiverticular band
2. Meckel's diverticulum - 21What is the mesodiverticular band?Residual persistent embryonic vitteline duct and associated mesentery which forms a mesenteric pouch which SI enters, perforates and then gets trapped
- 22What is Meckel's diverticulum?A remnant of the embryonic yolk sac which can form diverticulum off the jejunum which can entangle SI
- 23What is an epiploic foramen entrapment?- Most common cause of internal herniation in the horse and accounts for 5-23% of all strangulating lesions of the small intestine
- 24What is the epiploic foramen?Slit-like aperture that forms the entrance from the peritoneal cavity into the omental bursa and located in the right dorsal abdomen
- 25What are the anatomical boundaries of the epiploic foramen?The caudate lobe of the liver and the caudal vena cava form the dorsal anatomical boundary, whilst the pancreas, hepatoduodenal ligament and the portal vein contribute to the ventral border
- 26What passes through the epiploic foramen?Small intestine usually passes from left to right through the foramen, to lie in the right side of the abdomen above the duodenum.
- 27What are risk factors that are associated with development of epiploic foramen entrapment?- Crib-biting/windsucking behaviour
- Tall horses
- A previous episode of colic within the previous 12 months;
- Increased duration of stabling within the previous 28 days - 28Where is the gastrosplenic ligament?Broad attachment between the left part of the greater curvature of the stomach and the hilus of the spleen.
- 29What kind of herniation can occur with the gastrosplenic liagment?- Herniation of bowel (usually SI) through a defect in the ligament is occasionally encountered.
- Small intestine passes from caudal to cranial through the defect, resulting in the strangulated loop being located lateral to the stomach and craniolateral to the spleen. - 30Are intra-abdominal adhesions able to cause SI obstructions?Yes
- 31What kind of obstructions can adhesions lead to?- Simple obstructions can result from extraluminal compression or ‘kinking’ of the bowel, which leads to obstruction of intestinal transit .
- On rare occasions adhesions may form a hole, through which bowel can become incarcerated or strangulated. - 32When do adhesions form?- Adhesion formation is an important complication in all horses that have undergone previous colic surgery
- Adhesions can also be found in horses that have not undergone previous abdominal surgery. Intestinal inflammation is thought to be the most likely stimulus. Potential causes include: intra-abdominal abscesses; parasite migration or peritonitis (possibly following castration) - 33What are the 2 types of intussusceptions that can occur?1. Jejuno-jejunal
2. Ileocaecal - 34What are features of jejuno-jejunal intussusceptions?- Usually in foals with enteritis
- Can be imaged using ultrasonography
- Surgical reduction/resection - 35What is an ileocaecal intussusception?Invagination of the ileum into the caecum
- 36Give features of umbilical hernias.- Umbilical hernias are the most common type of external hernia in the horse and are estimated to occur in 0.5–2.0% of foals.
- Most umbilical hernias are congenital, but they may also develop within the first 2 months after birth.
- Most umbilical hernias are considered a cosmetic defect.
- Strangulation of the intestine in an umbilical hernia is rare - 37How is SI resected?- Isolate affected segment with two bowel clamps at either end
- Ligate blood vessels supplying affected segment
- Resect affected segment - 38What is done in SI anastomosis?- Anastamose intestine with sutures or staples in some situations
- Close defect in mesentery to prevent herniation
- Check patency of lumen and integrity of anastomosis (no leaks) and mesentery (no holes)
- Lavage and remove packing
- Decompress remaining bowel.
- Replace bowel in abdomen - 39What are features of the techniques for small intestine anastomosis?- Variety of techniques available - End to end, end to side, side to side techniques
- Anastomosis performed close to afferent artery so it has a good blood supply
- Continuous or interrupted patterns
- Single or two layer closures
- Appositional or inverting patterns
- Need to avoid restricting the lumen of the intestine at the anastomosis
- Avoid kinks or torsions at the anastomosis site - 40What are the indications for an intestinal biopsy?- Chronic inflammatory bowel disease
- Recurrent intermittent colic
- Malabsorption/weight loss syndromes
- Neoplasia.
- Equine grass sickness - 41How can intestinal biopsies be performed?- At laparotomy under general anaesthesia
- Laparoscopically assisted in sedated horse
- Biopsy 1x2cm suitable
- Full thickness preferable
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- 4. Gastrointestinal (Equine Gastrointestinal Surgery - Alistair Barr) Flashcards on GI surgery 2, created by Rachael Jones on 24/10/2018.
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