Gastrotomy and Partial Gastrectomy Flashcards
Otomy define
Incise into organ
Ectomy define
Removal of part of organ
What is the initial/main clinical sign associated with a gastric foreign body?
V+
Why do gastric FB often have intermittent clinical signs?
Peristalsis will naturally move the foreign body towards the pylorus, but generally gastric foreign bodies move around in the stomach so that they do not cause a complete obstruction all of the time
Other than V+:
Gastric FB clinical signs?
- Reduced appetite
- Cranial abdo pain
- Haematemesis
- Regurgitation
How common is cranial abdo pain with gastirc FB?
Unusual
How does haematemsis occur with gastric FB?
Haematemesis occurs in conditions where there is sufficient mucosal trauma such that there is enough bleeding that the blood can be visible in the gastric contents AND where there is vomiting.
How could a gastric FB cause regurgitation?
- Oesophageal irritation 2ry to V+
+/- distended stomach
Which of the following clinical signs is the most reliable in differentiating between vomiting and regurgitation?
A) Timing of vomiting/regurgitation in relation to feeding
B) pH of the vomitus/regurgitated food
C) Appearance of the vomit/regurgitated food
D) Presence of absence of abdominal contractions
D) Presence of absence of abdominal contractions
How likely are you to be able to feel a gastric foreign body on a clinical examination?
Unlikely
What clinical exam findings may be consistent with a gastric FB?
- Dehydration (from V+)
- tacky mm
- tachycardia
- Skin tent
Generally unremarkable
Why should a suspected gastric FB have haem and biochem? (3)
- Rule out metabolic causes
- Concurrent dx
- Baseline bloods (assess further tx response)
Electrolyte and acid-base disturbances are common in dogs with gastric foreign bodies secondary vomiting gastric fluids and inappetence.
What biochem abnormality is noted in more than 50% of gastrointestinal foreign bodies (regardless of the site of obstruction)?
Hypochloraemia
Initial imaging recommendation for a possible gastric FB?
- x rays
- Ultrasound
Xray positions for gastric FB?
Plain R lateral
Ventrodorsal
What is a gravel sign indicative of on xray?
Chronic partial GI obstruction.
If you can only take a R or L lateral x ray for a gastric FB - which one do you choose?
Right
What does a gravel sign look like? Where?
small radio-opaque fragments collected together at one location either at the pyloric antrum/pylorus in the case of a partial obstruction of the pylorus, or within a distended loop of small intestines close and proximal to the point of a partial intestinal obstruction.
What causes the “radio opaque” nature of the gravel sign?
Fragments of mineralised material in the food that accumulate proximal to a GI obstruction if they are too large and/or inflexible to pass through the narrowed lumen.
In which recumbency will the pyloric antrum and pylorus be full of fluid?
Right lateral
How is a gastric FB seen on u/s?
Distal shadowing
What i seen on U/S of gastric FB? (2)
- Gastric dilation - fluid + gas
- Demonstrate FB
If a metabolic cause has been ruled out and the reason for vomiting has not been determined on radiography and ultrasonography the next step is
Gastroscopy
If gastroscopy is used and no gastric FB seen. What should be done?
Biopsies! - abnormal areas, but also if normal- biopsies!
Where on the stomach wall is a gastrotomy incision made?
Ventral surface of the stomach midway between the greater and lesser curvatures in an area of least vascularity.
What size gastrotomy incision?
Depends on size of FB
How many layers is the stomach closed in?
2
Following gastrotomy to remove a gastric foreign body the stomach should be closed in two layers. Which of the following suture patterns are suitable for closing the stomach?
A) Simple continuous pattern in the mucosa/submucosa and simple continuous pattern in the seromuscular layer
B) Simple continuous pattern in the mucosa/submucosa and an inverting continuous pattern in the seromuscular layer
C) Inverting continuous pattern in the mucosa/submucosa and simple continuous pattern in the seromuscular layer
D) Inverting continuous pattern in the mucosa/submucosa and inverting continuous pattern in the seromuscular layer
E) Any of the above
E) Any of the above
Most common reason for a partial gastrectomy? (3)
= To resect necrotic gastric wall that can occur following compromise of blood supply to the stomach wall secondary to gastric dilation/volvulus (GDV);
= To remove gastric tumours;
= To remove non or perforated gastric ulcers.
Where is the most common location for a gastric tumour and why is surgery difficult?
- Lesser curvature; difficult area to access and especially to take margins
Where does gastric necrosis of a GDV normally effect?
Fundus
Why is the lesser curvature more difficult to access? (2)
- Cranial
- Short hepatogastic ligament
Where do gastric ulcers occur? (3)
Mostly the gastric body near the greater curvature or near pylorus
- can also occur in proximal duodenum
What is the first step to a surgical GDV? how?
Decompress the stomach!!
= Orogastric tube
= Large bore needle/catheter
Then correct torsion
How do we assess tissue viability with a GDV? (4)
- Prescence of peristalsis
- Gastric wall thickness
- Serosal surface colour
- Evidence of serosal capillary perfusion
What stomach thickness indicates non viability?
Thin (dark)
What colour stomach is non viable?
Black +/- green
How to assess stomach capillary perfusion?
Prick with a needle.
After how long do you make a decision on gastric viability - why?
5-10 mins
For example, extensive bruising/hyperaemia and absence of peristalsis does not necessarily indicate non-viability.
What indication means necrotic - without having to wait?
Black/green + thin
How far away do stay sutures need to be placed compared to gastric necrosis due to be removed?
3-5cm +
What happens to the blood vessels if they are to be resected with greater curvature?
ligated
If resection involves fundus or the body of the stomach; what NEEDS to be assessed?
The spleen should be assessed to ensure the splenic blood supply has not been compromised
How is stomach defect closed?
Two layers using a monofilament absorbable suture material (2 metric) placed in a simple continuous pattern in the submucosa/mucosa.
What “Type” of pattern should be used to close the stomach sub/mucosa where a large resection has happened? Why?
Appositional pattern is probably preferable to an inverting pattern in cases where a large resection has been performed because an appositional pattern will not narrow the gastric lumen.
How should the seromuscular layer be closed after ectomy?
A simple continuous appositional or inverting pattern using 2 or 3 metric monofilament absorbable suture material.
Instead of a linear manner, what may reduce the lumen reduction in closure?
Transverse
Which staplers can be used for gastrectomy? (2)
Thoracoabdominal (TA)
Gastrointestinal anastomotic (GIA)
Main issue of staplers for gastrectomy?
Expense
Following the use of a gastrectomy with a stapler; the tissue is excised with a blade. Then how is it closed?
Oversewn with continuous inverting pattern
Other than a gastrectomy; what can be used for necrotic areas with a GDV?
Gastric wall invagination
How is gastric wall invagination performed?
- A continuous inverting suture pattern is placed in healthy tissue on each side of the necrotic portion of stomach wall. (This invaginates the necrotic portion of stomach into the gastric lumen.)
A second continuous inverting line of sutures is placed alongside the first to further invaginate the stomach. An absorbable monofilament suture material, size 3 metric, should be used for this. The necrotic portion of the stomach sloughs into the gastric lumen and the stomach heals along the double layer of inverting sutures that were placed in healthy tissue.
Can you think of any advantages of performing gastric wall invagination for managing a necrotic portion of stomach? (2)
- Apposition of healthy tissue over necrotic stomach wall without penetration into the gastric lumen and therefore with no risks of spillage of gastric contents.
- Quicker than performing a partial gastrectomy; it is beneficial to minimise the anaesthetic time in patients that are cardiovascularly unstable.
What is a BIG thing you have to check once performed a gastric invagination?
Risk of gastric outflow obstruction by the invaginated portion occupying and obstructing the gastric lumen. If performing this technique, you should check that the invaginated portion of stomach will not obstruct the stomach.
What is the most common gastric tumour in dogs accounting for 70-80% of cases?
Adenocarcinoma
Which 2 breeds are predisposed to gastric adenocarcinoma?
- Staffie
- Sheltie
How many of dogs will have mets to LN at ime of diagnosis of adenocarcinoma?
70-80%
What does a gastric adenocarcinoma look like typically?
scirrhous causing a firm non-distensible texture (“leather bottle”) appearing firm and white/pale from the serosal surface.
Other than adenocarcinomas, other tumour types in dogs? (7)
Lymphomas, leiomyomas, leiomyosarcomas, gastrointestinal stromal tumours (GIST), mast cell tumours, plasmacytomas and fibrosarcomas
How common is the stomach to be involved in tumour for cats?
Least likely area of GIT
Most common feline gastric tumour?
Lymphoma
How common is it for the stomach to be affected by adenocarcinoma in cats?
Rare.
Clinical signs of gastric neoplasia (4)
Chronic, progressive vomiting
Reduced appetite
Weight loss
Abdominal pain
If there is mucosal ulceration with gastric tumours; what colour may the V+ be?
blood tinged or contain “coffee ground
What is seen on haematology with gastric neoplasia?
Microcytic hypochromic anaemia
What is seen on biochem with gastric neoplasia?
Hypoproteinaemia
- Electrolytes can change due to V+
What can leiomyomas and leiomyosarcomas do to biochem?
Hypoglycaemia (paraneoplastic)
How can positive contrast agent be used with gastric neoplasia?
May reveal a mass lesion projecting into the gastric lumen, gastric ulceration or abnormal/delayed gastric emptying.
What is looked for with ultrasound and gastric neoplasia? (2)
- Mass lesion
- Altered wall thickness
What will CT identify with gastric neoplasia? (4)
- Gastric lesion
- enlarged LN
- Abdo abnormalities
- Pulmonary mets
What is the aim of medical with gastric neoplasia?
Alleviate 2ry effects
Reducing gastric pain and blood loss from ulceration and reducing oesophagitis from chronic vomiting. How can this be done? (2) Include medication(2,1) and the effect
- Reducing gastric acid secretion
=Antacids
*Histamine H2 receptor blockers: famotidine, ranitidine, cimetidine
= Proton pump inhibitors (inhibition of H+/K+-ATPase)
*Omeprazole - Protecting gastric and oesophageal mucosas
=Sucralfate (polyaluminium sucrose)
Reducing vomiting from gastric retention:
What med and modification can be used for this?
Prokinetics
Dietary modification
most malignant gastric tumours affect the greater curvature where access for surgery is difficult and a wide margin of excision (necessary for treating malignant disease to avoid local recurrence) is rarely possible.
Is this statement true or false?
FALSE- most malignant gastric tumours affect the lesser curvature where access for surgery is difficult and a wide margin of excision (necessary for treating malignant disease to avoid local recurrence) is rarely possible.
If the mass is located at the lesser curvature, the gastric wall is thickened with an abnormal texture and there is no clear distinction between the margin of the mass and normal tissue
How to approach this?
Biopsy only
How do prokinetics reduce V+ from gastric retention? (2)
What meds? (2)
=enhance gastric emptying rate
= increase lower oesophageal sphincter tone
E.g. cisapride, metoclopramide
How can you use dietary modification reduce V+ from gastric retention? (4)
= feeding low-fat diet
= slurry/soft consistency
= small frequent meals
= postural feeding
Where and how are biopsies taken of gastric masses?
Centre of mass; incisional; full thickness
It is common for the normal layers of the stomach wall to have been lost and replaced by a markedly thickened and abnormal tissue.
How to suture?
simple interrupted appositional sutures using a monofilament absorbable suture material.
Single layer
True or false:
With gastric mass biopsy; No attempt should be made to invert the suture line and a single layer of sutures should be placed.
True
If the tissue is very thick and abnormal there is a risk that the sutures could “cheese wire” through, with a gastric mass. How would you close this?
Thicker suture material (3 metric) should be used, large/deep bites of tissue taken, and the sutures tightened and tied very carefully.
Resection of a malignant gastric tumour by partial gastrectomy can be performed for what reason? (2)
excisional biopsy and palliation
with curative intent
in the rare event that the mass is of a limited size and at a location such that it can be resected with a gross margin of..?
3-5cm
What surgical approach can be used for resection of a tumour in:
Non-circumferential tumours of the body, fundus, or antrum
Partial gastrectomy
What surgical approach can be used for resection of a tumour in:
Mucosal/submucosal tumours?
Submucosal resection technique
When is Submucosal resection technique appropriate?
ONLY for benign
What surgical approach can be used for resection of a tumour in:
Distal stomach/pylorus ?
Pylorectomy and gastroduodenostomy (challenging!!)
What surgical approach can be used for resection of a tumour in:
Distal stomach/pylorus and proximal duodenum
Partial gastric and duodenal resection, gastrojenunostomy and biliary rerouting procedures
Partial gastric and duodenal resection, gastrojenunostomy and biliary rerouting procedures are particularly challenging.
What is the morbidity and mortality?
HIGH
Submucosal resection of a mass is achieved as follows:
1 Place stay sutures around the proposed gastrotomy site in the stomach wall on the opposite side to the mass.
2. Make a gastrotomy incision.
Next step?
Place a traction suture through the mass to elevate it towards the gastrotomy site and incise halfway around the mass with an elliptical incision including a margin of 1-2 cm of grossly “normal” tissue.
How is the defect closed with a submucosal resection?
Close the defect using a simple continuous monofilament absorbable suture material (1.5, 2 or 3 metric) placed in the mucosa/submucosa.
Following defect closure with a submucosal resection; how is the mass removed?
Complete the elliptical incision to remove the mass and continue suturing as above to close the mucosal defect.
How to close gastrotomy incision with a submucosal resection?
Close the gastrotomy incision using 1.5-3 metric monofilament suture material in a two-layer pattern.
Causes of gastric ulcers? (9)
NSAIDS
Glucocorticoids
Renal dx
Hepatic dx
Neoplasia
FB
MCT
Gastrinoma
Exogenous toxins
What is the theory behind NSAIDS -> ulcer?
- a direct topical effect of the weakly acidic and lipid soluble NSAID on the gastric mucosa;
- a systemic inhibition of cyclooxygenase resulting in decreased gastroprotective prostaglandin production. This will result in reduced gastric mucosal blood flow, epithelial mucus production, bicarbonate secretion and epithelial turnover.
The reason as to why glucocorticoids cause ulcers is unknown. But what is proposed? (3)
- Decreased mucus production,
- Decreased mucosal cell renewal
- Changes in gastric mucus composition
Proposed theory for renal dx - ulcers?
increased gastric acid secretion secondary to hypergastrinemia (because of reduced renal gastrin clearance)
Proposed theory for hepatic dx - ulcers? (2)
increased gastric acid production stimulated by increased circulating levels of gastrin and histamine secondary to the reduced hepatic metabolism of these compounds;
derangement of mucosal blood flow that can occur with portal hypertension and thrombosis of gastric vessels.
How FB cause ulcers?
These cause physical erosion or abrasive trauma to the gastric mucosal surface.
How to MCT cause gastric ulcers?
Affected animals can have increased circulating histamine levels that will stimulate gastric acid production and predispose to gastric ulcers.
How do gastrinoma cause gastric ulcers?
Excessive production of gastrin by this tumour will increase gastric acid production.
What may prevent peritonitis with a gastric ulcer rupture?
Omental adhesions
Signs of gastric ulcer? (4)
- Lethargy
- Anorexia
- Abdo pain
- V+
How can x-rays be used to diagnose gastric ulcers?
- Likely to look normal (unless underlying FB/mass)
- If perforates; free abdo gas may be identified
What may be seen on ultrasound with gastric ulcers? (6)
- FB
- Mass
- Thickening; loss of layers
- Bright mesenteric fat
- Free peritoneal air
- Fluid
What may support evidence of peritonitis with abdocentesis + gastric ulcer? (4)
- Neutrophils
- Extra/intracellular bacteria
- Blood -peritoneal fluid glucose
- Blood-peritoneal lactate
Where to sample for gastric ulcers with gastroscope?
Centre + periphery
If permitted; abnormal tissue should be removed by gastrectomy with what margin?
2-3cm
Where are gastric perforations asscoiated with NSAID use located? (3)
- Proximal duodenum
- Pylorus
- Pyloric antrum
The pylorus and proximal duodenum are anchored to the liver by (2)
Hepatogastric + hepatoduodenal ligament
What are the hepatogastric and hepatoduodenal ligaments formed from?
Lesser omentum
What ligament can partially be cut to aid accessibility to the pylorus?
Hepatoduodenal
What structure runs in the hepatoduodenal ligament that we must take great care not to cut?
Common bile duct
At surgery pyloric and proximal duodenal ulcers are difficult to remove, what should happen with these?
These ulcers should be debrided and sutured (full-thickness simple interrupted sutures using 2 or 3 metric monofilament absorbable suture material) or resected with closure as above.
What should happen with debrided/resected tissue?
Histopath
Which is the simplest gastropexy?
Incisional
Before pexy - how do you know the stomach is in the right place?
Pylorus - RHS
Where is the incision for an incisional pexy and how long?
A 3-5 cm incision is made in the ventral surface of the pyloric antrum midway between the greater and lesser curvatures of the stomach.
What happens to the seromuscular layers during an incisional pexy?
The 0.5 cm area adjacent to the incision are bluntly dissected from the deeper submucosal/mucosal layers to encourage lifting and separation of the seromuscular layer for ease and accuracy of subsequent suturing to the body wall.
Following gastric incision, what incision is then made during a pexy? Where? Orientation?
Corresponding incision - through the peritoneum and transverse abdominal oblique muscle just behind the last rib
Approx one third of the distance from the ventral to the dorsal midline.
Orientation perpendicular to the midline coeliotomy incision or parallel to the last rib.
Following muscle + gastric incision, what happens next during a pexy? Include suture pattern + size
- The seromuscular layer of the stomach along the cranial aspect of the incision made in the pyloric antrum is then sutured to the cranial part of the incision made in the body wall using either simple interrupted or a simple continuous pattern and monofilament slowly absorabable suture material. Suture one side then the other
Three metric suture material would be a suitable size to use in a large or giant breed of dog. The suture is continued so that the seromuscular layer along the caudal edge of the incision in the stomach is sutured to the caudal edge of the incision in the body wall.
What term is used if the stomach is fixed on the LHS?
Fundopexy
When is a fundopexy common?
Conjunction with a hiatal hernia repair
Post op care following gastrotomy/gastrectomy (5)
- IVFT
- Nutrition
- Analgesia
- PPI/Histamine antagonise
- Prokinetic
Which of the following drugs has a prokinetic effect at the stomach?
Erythromycin
Ranitidine
Maropitant
Metoclopramide
Cimetidine
Famotidine
Erythromycin
Metoclopramide
Cimetidine
What dose of erythromycin is used for prokinetic and how does this work? (cat vs dog)
Subtherapeutic antimicrobial
Motilin agonist - CATS
5HT3 antagonist - DOG
Where does ranitidine act and what is the effect?
H2 antagonist - inhibit gastric acid
Where does metoclopromide act? (2)
-Dopamine antagonist
- 5-HT4 agonist
How does motilin prokinetic?
- Enteric nuerons
- Smooth muscle
- Vagal
What does 5-HT3 inhibit?
Myenteric plexus
Ranitidine prokinetic is due to what inhibition?
Acetylcholiinesterase
Where does ranitidine have greatest effect in GIT?
Proximal GIT
The increased availability of acetylcholine that accompanies ranitidine use allows greater activity of what muscle?
Gastric smooth muscle
Where does maropitant act?
NK1 antagonist
Where does cimetidine act?
H2 antagonist
inhibits gastric acid secretions
Where does cimetidine act?
histamine H2-receptor antagonist that inhibits gastric acid secretions
What is the preferable imaging modality if you are concerned that your gastrotomy/gastrectomy patient could have peritonitis and/or gastric distension?
Ultrasound
