E2: Stomach and GDV Flashcards
What are the gastric layers? Which is strongest?
From outside to inside: Serosa - Muscle - Submucosa - Mucosa
Submucosa is the strongest (holdng layer)
Pica predisposes animals to gastric foreign bodies. Name some conditions that predispose an animal to pica.
Iron deficiency
Hepatic encephalopathy
Pancreatic exocrine insufficiency
Which of these is not a clinical sign associated with a gastric foreign body?
Vomiting
Fever
Lethargy
Abdominal pain
Anorexia
Fever
Which of these are possible lab findings for an animal with a gastric foreign body?
Anemia
Leukocytosis
Leukopenia
Neutropenia
Renal azotemia
Pre-renal azotemia
Metabolic alkalosis
Metabolic acidosis
Hyperkalemia
Hypokalemia
Hyperchloremia
Hypochloremia
Anemia
Leukocytosis
Pre-renal azotemia
Metabolic alkalosis
Metabolic acidosis
Hypokalemia
Hypochloremia
If you decide to medically manage a foreign body, what do you need to include in your therapy?
If you needed to induce vomiting, what would you use?
Fluid therapy: rehydrate, correct electrolyte imbalances
Monitor using serial rads
Induce vomiting in dog- Apomorphine
Cat- Xylazine
T/F: Many gastric foreign bodies can be removed endoscopically.
True
Where should you make your surgical approach for gastric foreign body removal?
Ventral midline celiotomy (from xiphoid to pubis)
Incision in hypovascular aspect of stomach between greater and lesser curvature
To reduce contamination during a gastrotomy, isolate the stomach from the remaining abdominal contents with moistened _________. Place _________ to assist in manipulation of the stomach and help prevent spillage of gastric contents.
Laparotomy sponges
Stay sutures
How do you close a gastrotomy incision- what pattern(s) could you use in the first layer and what tissue(s) will this layer incorporate? Second layer?
What alternative method could you use to reduce post-op bleeding?
First layer: Cushing or simple continuous pattern
Tissues: Serosa, muscularis, and submucosa
Second layer: Lembert/Cushing pattern
Tissues: Serosa, muscularis and submucosa
Alternative: Close mucosa in simple continuous pattern as separate layer followed by inverting pattern including all other tissue layers
(Cushing then Cushing/Lembert = Double layer inverting
Simple then another simple followed by Cushing/Lembert= Double layer appositional then inverting)
What clinical signs are associated with gastric outflow obstruction?
Chronic intermittent vomiting of partially digested food hours after feeding
(If congenital signs seen at weaning)
What congenital abnormality causes benign gastric outflow obstruction?
Pyloric stenosis
What artery supplies the lesser curvature of the stomach? What is/are the parent artery/arteries?
Greater curvature? What is/are the parent artery/arteries?
Lesser- Gastric arteries (left and right)- parent- Celiac artery
Greater- Gastroepiploic arteries (left and right)- parent = Celiac A
Short gastric arteries - parent= Splenic A
What breeds are predisposed to congenital pyloric stenosis?
Brachiocephalic dog breeds (Boxers, bulldogs)
Siamese cats
What is the suspected etiology for congenital pyloric stenosis?
Excess gastrin production
(trophic for gastric smooth muscle and mucosa)
Also possible cause of Chronic Hypertrophic Pyloric Gastropathy
What are the diagnostic modalities for determining pyloric stenosis?
Radiographs- to look for gastric distenssion or delayed gastric emptying (evidenced by a not-empty stomach after 8 or more hours of fasting)
Contrast radiography- to look for ‘beak’ or ‘apple core’ sign
Ultrasonography-
What surgeries can you perform to correct congenital pyloric stenosis?
Pyloromyotomy (Fredet-Ramstedt procedure)
Transverse pyloroplasty (Heineke-Mikulicz procedure)
Aquired hypertrophy of which layer or layers of the pyloris causes CHPG (chronic hypertrophic pyloric gastropathy)? Which breeds are predisposed? Is there a sex or age prediliction?
Mucosa and or muscular hypertrophy
Small breed dogs (<10kg) such as Shih-tse, Lhasa apso, Maltese
Males predisposed
Middle aged to older
What diagnostic tool can be used to evaluate the middle and pyloric wall thickness to diagnose CHPG? What alernative modality can you use if you also need to take biopsies?
Ultrasound
Endoscopy
In addition to a Heineke-Mikulicz pyloroplasty, which 2 other surgical techniques can you use to manage CHPG? What are advantages and disadvantages of each?
Y- U Pyroplasty
_Advantages:_Increase diameter of pylorus, access to excise hypertrophied mucosa
Disadvantages: Potential flap tip necrosis, possible side effect of rapid gastric emptying
Pylorectomy w/Gastroduedenostomy (Bilroth I)
Advantages: All diseased tissue can be removed
Disadvantages: technically more demanding, increased risk of “dumping” syndrome and reflux gastritis (due to direct connection between duodenum and stomach)
_________ tumors are commonly found near the cardia.
_________ tumors are commonly found in the pyloric antrum or the lesser cuvature of the stomach.
Leiomyoma, LSA
Adenocarcinoma
What are the sigalment, physical finding, treatment options and prognosis for gastric adenocarcinoma?
Signalment: Male, 8-10yo, Staffies, Belgian shepherds
Physical findings: plaque-like mucosal lesions with ulcers, raised sessile or polypoid lesions, diffuse infiltration (linitis plastic, scirrhous stomach wall), on US see mural thickeing and loss of normal gastric wall
Treatment options: aggresive sx exision via gastrectomy, 5cm margins
Pallitative tx: By-pass procedure (Bilroth I or II), chemotherapy?
Prognosis: Guarded to poor, no sx= 2-4mo, aggressive therapy= 10mo
What are the sigalment, physical finding, treatment options and prognosis for gastric leiomyosarcoma?
Signalment: 7-8 yo
Physical findings: ulceration, mass near cardia protruding into the gastric lumen
Treatment options: submucosal resection, Partial gastrectomy (if extensive or ulcerated)
Prognosis: median survival 21 mo, good to guarded, recurrence possible
What are the sigalment, physical finding, treatment options and prognosis for gastric leiomyoma?
Signalment:older dogs, INCIDENTAL finding
Physical findings: mass near cardia protruding into the gastric lumen
Treatment options: submucosal resection, Partial gastrectomy (if extensive)
Prognosis: Good to guarded
How would you describe this stomach wall that has been affected by a gastric adenocarcinoma?
Scirrhous
What are the sigalment, physical finding, treatment options and prognosis for Pythiosis?
Signalment: Young dogs, Labrador Retrievers, Cavalier King Charles Spaniels and German Shepherd Dogs predisposed (highest incidence in Gulf Coast States in fall or early winter and usually after a summer of flooding and large amounts of precipitation)
Physical findings: severe inflammation and infiltration (submucosa and muscularis affected), intense fibrotic reaction, transmural thickening (esp gastric outflow area), vomiting, inappetence, weight loss, diarrhea
Treatment options: Wide surgical excision (antifungals INEFFECTIVE)
Prognosis:Guarded to poor, MST 26.5 days
What type of suture should be avoided in gastric surgery?
Chromic gut
What is a Bilroth II and what are the indications to perform it?
What are some disadvantages of using this procedure?
Gastroenterostomy- partial gastectomy followed by gastroenterostomy
Indications: Extensive gastric resection making gastroduodenostomy impossible
Disadvantages: A LOT of complications - Alkaline gastritis (bile and pancreatic secretions flow into stomach), “Blind loop” syndrome (gastric contens move orally and putrefy), Marginal ulceration (of jejunal mucosa due to acid)
What is a Bilroth I and what are the indications to perform it?
What are some advantages and disadvantages of using this procedure?
Pylorectomy Gastroduodenostomy
Indications: neoplasia, outflow obstruction caused by muscular hypertrophy, ulceration of gastric outflowtract
Advantage: All dieased tissue can be removed
Disadvantages: difficulty, risk for “dumping” syndrome and reflux gastritis (must use extreme care when incising in pyloric area to avoid damaging COMMON BILE DUCT where it traverses lesser omentum)
How does a Bilroth I differ from a Bilroth II?
In Bilroth II the distal stomach and proximal duodenum are closed after pylorectomy, and the jejunum is attached with a side-to-side anastomosis to the diaphragmatic surface of the stomach
In Bilroth I stomach and duodenum are connected where the pylorus has been removed
_________ is the distension of the stomach with fluid, food, and/or gas. Treatment is _______ (medical/surgical).
_________ is the enlargement of the stomach associated with rotation on its medenteric axis. Treatment is _______ (medical/surgical).
Dilation/ dilatation - Medical
Dilation-Volvulus - Surgical
What risk factors for developing GDV have been identified?
Exercise: following large meals? - largely disproven
Diet: highly processed food?, lots of water before exercising? large volume once daily, eating rapidly, feeding from raised feed bowl, dry kibble, fats/oils in 1st 4 ingredients (fish or egg supplements decreased risk)
Age: older=higher risk
Weight: UNDERweight
Body confirmation: Deep, narrow thorax
History: Having a 1st degree relative with hx of GDV, being stressed, vomiting, fearfulness, anxiety, spending 5 hours/day with owner
Genetics: Irish Setters, Great Danes, GSD, males
Gastric enlargement is thought to be associated with ___________ obstruction.
Gastric outflow
(mechanical or functional)
Once the stomach dilates, normal physiologic means of ______________ are hindered because the esophageal and pyloric portals are obstructed.
Removing air
Generally, with GDV the stomach rotates in a ______direction when viewed from the surgeon’s perspective (with the dog on its back and the clinician standing at the dog’s side, facing cranially)
Clockwise
(usually 220-270 deg, but may be 90-360)
In what direction/where are the duodenum, pylorus, and spleen displaced with GDV?
Duodenum and pylorus move ventrally, left of midline (end up between stomach and esophagus)
Spleen is usually displaced to right ventral side of abdomen
Why does myocardial ischemia occur following GDV?
Caudal vena cava and portal vein are compressed by distended stomach leading to decreaed venous return and decreased cardiac output
T/F: Arrhythmias occur in many dogs with GDV, particularly those with gastric necrosis.
True
Fill in the blanks
Blue: Gas accumulation
Red: Abnormal gastroesophageal function and Delayed gastric emptying
What contributes to the gas which collects in the stomach during GDV?
Aerophagia
Bacterial fermentation of carbs
Diffusion from bloodstream
Metabolic reactions
What has been implicated as causing much of the tissue damage that ultimately results in death after correction of GDV?
Reperfusion injury
The term “torsion” implies a ______ (clockwise/counter-clockise) rotation of less than ____ degrees while the term volvulus implies a ______ (clockwise/counter-clockise) rotation of more than ____ degrees.
The term “displacement” implies a _______(clockwise/counter-clockise) rotation of less than _____degrees.
Torsion: (less than) 180 clockwise
Volvulus: (more than) 180 clockise
Displacement: (less than) 90 counter-clockwise
What covers the stomach when it is displaced clockwise but not when it is displaced counter-clockwise?
Omentum
What are the typical clinical signs associated with GDV? Which is most common?
Most common: Nonproductive retching
Restlessness
Hypersalivation
“Praying” position
Vomiting
Weakness
Collapse
(note- acute)
What diagnostic modality do you use to differentiate dilation from dilation + volvulus? What views are warrented and why?
Radiographs
Right lateral + DV: to facilitate filling the abnormally displaced pylorus with air so it can be easily identified
(Rlat w/GDV pylorus lies cranial from body and separate from rest of stomach by soft tissue = Reverse C Sign/Double bubble
DV w/GDV pylorus is gas-filled structure to left of midline)
You take rads of a dog with suspected GDV and in addition to noting the classically reverse-C sign, you also see free abdominal air and air within the wall of the stomach. What does this suggest?
Free air -Gastric rupture
Air in stomach wall- Necrosis
SURGICAL EMERGENCY (both or either)
Which type of GDV is most commonly associated with a history of chronic GI signs?
Counterclockwise displacement
(Partial GDV)
T/F: You can differentiate GDV from gastric dilatation without volvulus if you are able to pass a stomach tube.
False, stomach tubes canf requently be passed in dogs with twisted stomachs
What are the key components of pre-op stabilization of GDV patients and in what order do you want to perform these treatments?
-
Fluids, pain meds and monitoring
Cystalloid slns or hypertonic saline + colloids
Full mu
EKG/BP - Decompression via tube (1st choice) or trocharization then tube
- Radiographs and CBC/Chem: Correct and A/B or significant e-lyte disturbances, especially LACTATE
- Antimicrobials and Free radical scavengers
- Pre-oxygenate, rapid induction (Etomidate, Alfaxalone, Propofol)
What are the options for correcting the hypovolemic shock often associated with GDV?
Isotonic fluids (90 ml/k/hr)
Hypertonic (7%) saline (4-5 ml/kg q5-15min)
Hetastarch (5-10ml/kg q10-15min)
7.5% Saline + Hetastarch (7.5% sln) 4 ml/kg q5min
What methods can be used to decompress the stomach? Describe them as well, including precautions that must be taken.
Preferred method: Orogastric intubation- use bite block, measure and mark tube length using xiphoid as landmark, advance tube slowly while rotating. After removing air, lavage with warm water.
Trocharization- use large bore needle/catheter at most tympanic site which has been clipped and cleaned, followed with tube
What are the potential complications associated with trocharization?
Hitting the spleen causing hemorrhage
Leakage of gastric contents into abdominal cavity resulting in infalmmatory response/damage
What are some examples of free radical scavengers and why are they potentially beneficial in treating GDV patients?
Acetylcysteine
Vitamine C and E
Selenium
Desferoxamine (iron chelator)
Lidocaine
Purpose: prevent damage caused by reperfusion which releases ROS into circulation
What are the advantages of early surgical correction in the management of GDV?
Improves bloodflow (prevent gastric necrosis)
Prevent arrhythmias
Why must the stomach be lavaged following decompression?
Otherwise the stomach will redilate after the tube is withdrawn
What area of the stomach is most commonly affected by vascular compromse?
Greater curvature near short gastric arteries (junction between fundus and body)
How is viability of the stomach typically assessed? How can palpation of the stomach wall be helpful in assessing viability?
Color
Pulsation of blood vessels
Bleeding from cut surface
Peristalsis (should resume almost immediatly after respositioning)
Surface oximetry
Palpation is helpful becasue a thinned wall indicates vascular compromise and potential necrosis (now or in the future)
What abnormalities in the spleen may occur with GDV and how are they managed?
Venous congestion- is self-limiting and tends to resolve when stomach is derotated
Vessel thrombosis- Splenectomy
Splenic torsion- Splenectomy
What is a disadvantage of using a double inverting pattern to close a lesion? Where would you never want to use an inverting pattern?
It decreases the lumen
Close to the pylorus (or cardia)
What layer(s) of the stomach are affected by congenital pyloric stenosis?
Only the muscularis
What layers can be affected with aquired pyloric stenosis?
Muscularis
Mucosa
What pathologic classification would you give a dog with CHPG if muscular and mucosal hypertrophy are present?
Grade II
T/F: If only muscular hyperplasia is present with CHPG, its pathologic classification is Grade I.
FALSE, muscular HYPERTROPHY
What are the 2 pathologies that indicate you have a grade III CHPG?
HyperPLASIA of the mucosa
Inflammation of the mucosa and submucosa
What is the difference between hypertrophy and hyperplasia?
Hypertrophy- increase in cell SIZE
Hyperplasia- increase in cell NUMBER
The higher the grade of CHPG, the more invasive the procedure to correct it needs to be. Name 2 surgeries you could do for a low classification and 1 you could do for a higher classification.
Low: Heineke-Mikulicz Pyroplasy or Y-U pyroplasty
High: Bilroth I gastroduodenostomy
What type of suture pattern would you use to close an incision close to the pylorus?
Single layer appositional
What are the goals of a gastropexy?
Inspect the stomach and spleen to identify and remove damaged tissues
Decompres the stomach and correct any malpositioning
Adhere stomach to body wall to prevent subsequent malpositioning (doesn’t prevent dilation)
To create a permanent adhesion, the gastric muscle must be in contact with the muscle of the body wall. Why?
Intact gastric serosa does not form permanent adhesions to an intact peritoneal surface.
Describe the technique, advantages and disadvantages of an incisional/muscular flap gastropexy.
Technique:
- Make incision in seromuscular layer of gastric antrum
- Make another incision in right ventrolateral abdominal wall through peritineum and internal facia of rectus abdominis or trasnverse abdominis muscles
- Suture edges of incision in simple continuous pattern (2.0 absorbable or non-abs)
- Ensure contact between muscularis layer and abdominal wall muscle
- Suture cranial margin first, then caudal margin (or can raise flaps in stomach and body wall to increase tissue contact)
Advantages: Easier than circumcostal, quicker, gastric lumen not opened
Disadvantages: less strong than circumcostal, no direct access to gastric lumen if need post-op decompression
Describe the technique, advantages and disadvantages of a Belt Loop gastropexy.
Technique:
- Elevate a seromuscular flap in gastric antrum and make 2 transverse incision in ventrolateral abdominal wall through peritoneum and abdominal musculature (2.5-4cm appart 3-5cm long)
- Create a tunel under abdominal musculature with forceps
- Place stay sutures in edge of antral flap and use them to pass flap from cranial to caudal under the muscular flap
- Suture flap to original gastric margin in simple continuous pattern (2.0 abs or non-abs) or use skin staples
Advantages: Easier than circumcostal, quicker, gastric lumen not opened
Disadvantages: less strong than circumcostal, no direct access to gastric lumen if need post-op decompression
Describe the technique, advantages and disadvantages of a circumcostal gastropexy.
Technique:
- Make either 1 or 2-layer hinged flap by incising through seromuscular layer of pyloric antrum (dont incise gastic mucosa)
- Elevate flap by dissecting under muscularis (if 1-hinged flap place hinge toward lesser curvature)
- make 5-6cm incision over 11th or 12th rib at costochondral junction (do not penetrate diaphragmatic attachments to body wall)
- Form tunnel under rub using Carmalt/hemostat
- Place stay sutures in flap (if 2-flap technique on flap closest to lesser curvature)
- Pass gastric antral flap craniodorsal under rib and suture to original gastric margin
Advantages: stronger adgesion than most other techniques, dimished risk of gastric leakage and abdominal contamination (gastric lumen not opened)
Disadvantages: technically challenging, complications include pneumothorax and rib fracture, no direct access to gastric lumen if need post-op decompression
Describe the technique, advantages and disadvantages of a tube gastropexy.
Technique:
- Stab incision into R abdominal wall caudal to last rib, 4-10cm from midline
- Foley catheter through incision
- Place purse-string sutures (2.0 absorbable) so catheter/balloon is in hypovascular region of seromuscular layer of ventral surface of pyloric antrum (where it won’t obstruct gastric outflow)
- Inflate balloon with SALINE and secure purse-string sutures
- Preplace 3-4 absorbable sutures between pyloric antrum and body wall where tube exits
- Draw stomach to body wall and tie preplaced sutures
- Secure tube to skin using Roman sandle suture pattern (DO NOT PENETRATE TUBE)
- Leave tube in place 7-10days
- To remove delfate baloon, leave skin incision open to facilitate drainage
Advantages: Quick, simple, allows post-op gastric decompression and placement of meds directly into stomach
Disadvantages: Longer hospitalization (must allow adhesions to form), peritonitis if improperly placed
Describe the technique, advantages and disadvantages of an incorporating/ laproscopic-assisted gastropexy.
Technique:
- Place first cannula just caudal to umbilicus
- Place second cannula jusr right of midline, 2-4cm behind last rib (incision parallel to rib)
- Pull stomach through incision
- Place stay sutures between stomach adn body wall
- Perform muscular flap/incisional pexy
Advantages: Pyloric antrum accurately visualized, don’t need special instruments
Disadvantages: Expertise in gastrscopy required, potential organ trauma
What is the most critical time period for post-op GDV patients?
The first 4 days after surgery
What types of arrhythmias are most common with GDV? When do these usually occur?
Ventricular arrhythmias:
V-tac
VPCs
Paroxysmal runs
Idioventricular rhythm (slow v-tach)
Mutifocal VPCs
Begin 12-36hrs after surgery (usually abate 24-72 hrs post-op)
What are the potantial causes of arrhythmias with GDV?
Myocardial ischemia (decreased venous supply and thus CO)
E-lyte abnormalities (Hypokalemia very common)
A/B alterations
Vasoactive substances
Imbalance of autonomic nervous system
T/F: Lidocaine as an antiarrhythmic is ineffective if the patient is hypokalemic.
True
When should arrhythmias be treated? With what? What if you give too much?
Treat if arrythmias is interfering with cardiac output = Poor peripheral pulses, pulse deficits, weakness
Mutiform arrythmias/VPCs
R-on-T
Sustained ventricular rate >160bpm
Treatment: IV lidocaine, first bolus and if respond well then CRI (start with low dose)
Alternatives: Procainamide, Sotalol
Lidocaine toxicity: muscle tremors, vomiting, seizures
What is the prognosis for GDV patients?
Uncomplicated cases: 80-90% survival rate
Lower suvival if: Pre-op arrhythmias (38% mortality), Gastric necrosis (46%), patrial gastrectomy (35%), splenectomy (32%), partial gastrectomy + splenectomy (55%)
