Exam 1 Flashcards
Lecture 1-2
- List recommendations for clients to reduce the chance of their dog developing Gastric Dilatation and Volvulus.
What are some predisposing factors of GDV?
In what direction and how many degrees does the stomach rotate?
What effect does GDV have on cardiac flow and function?
What kind of tissue injury can occur after attempt in correction of GDV?
Gastric Dilation-Volvulus (GDV) is the enlargement of the stomach associated with rotation on its mesenteric axis. (Bloat or gastric torsion)
-A simple dilation: stomach is engorged with air or froth, but not malpositioned (no rotation)
-Early recognition and detection/intervention of GDVs is essential for survival.
- Feed several meals per day
- Avoid stress during feeding
- Restrict exercise before and after meals (~1 hour)
- Do not use elevated feeding bowls
- Do not breed dogs with first degree relatives with a H/O or GDV
- Prophylactic gastropexy in high-risk dogs
- Seek veterinary care at first sign of GDV
- Slow feeder bowls
Predisposing factors:
-Male gender
-Eating once a day
-Eating rapidly
-Stress
-Large volume feeding
-Increasing age
-Aerophagia (sucking air)
-Fearful temperament
-Anatomic predisposition: having a deeper thorax and narrower thorax
-Ileus
-Trauma
-Vomiting
-First Degree relative with GDV
-Dry food with oil and fat as main 4 ingredients
-Atmospheric influence in military working dogs
The stomach rotates in a clockwise direction when view from the surgeon’s perspective. Usually 220-270 degrees
Duodenum and pylorus move ventrally and to the left of midline between the esophagus and stomach.
Spleen usually displaced to the right ventral abdomen
Cardiac Function
-Cardiac Arrhythmias (especially if necrosis present)
-Caudal vena cava and portal vein compression reduces venous return and Cardiac Output, myocardial ischemia.
-Reduction of: central venous pressure, stroke volume and mean arterial pressure.
-Stomach necrosis, pressure on diaphragm, raptures etc.
Ischemia-Reperfusion injury and death
Obstructive shock: kidney, heart, pancreas, small intestine
Multi-organ/system failure
Multi-factorial process resulting in extensive tissue destruction
- Identify cardiac arrhythmias as common complication associated with Gastric Dilatation and Volvulus; develop a plan to identify this complication before, during, and after surgery; and given a clinical presentation that includes ECG findings, decide if medical intervention is warranted.
Cardiac Function
-Cardiac Arrhythmias (especially if necrosis present)
-Caudal vena cava and portal vein compression reduces venous return and Cardiac Output, myocardial ischemia.
-Reduction of: central venous pressure, stroke volume and mean arterial pressure.
-Stomach necrosis, pressure on diaphragm, raptures etc.
Ischemia-Reperfusion injury and death
Obstructive shock: kidney, heart, pancreas, small intestine
Multi-organ/system failure
Multi-factorial process resulting in extensive tissue destruction
- Identify plasma lactate levels as a laboratory value, when elevated, is associated with gastric necrosis and a poor prognosis.
Plasma Lactate is prognostic: higher values associated with gastric necrosis and poor prognosis
-Vascular Stasis resulting in Increased lactic acid = Metabolic acidosis
-Metabolic alkalosis from hydrogen ion sequestration may offset acidosis resulting in normal blood pH.
-CBC seldom informative
-Potassium may be normal or elevated
-Thrombocytopenia with DIC
-Hypokalemia more common
- Describe the anatomic displacement of the stomach (direction of rotation) that occurs during a Gastric Dilatation and Volvulus, when viewed from the surgeon’s perspective.
The stomach rotates in a clockwise direction when view from the surgeon’s perspective. Usually 220-270 degrees
Duodenum and pylorus move ventrally and to the left of midline between the esophagus and stomach.
Spleen usually displaced to the right ventral abdomen
- List the three primary goals of surgery on a patient with Gastric Dilatation and Volvulus, and recommend methods for achieving each of those goals.
Does decompression mean de-rotation?
-Free abdominal air suggests gastric rupture immediate surgery
-Air within the stomach indicates necrosis
Primary Goals
- Assess viability: inspect the stomach and spleen to identify and remove damaged or necrotic tissue
- Decompress/Derotation: decompress the stomach and correct the malposition
- Gastropexy: DO IT!: recurrence rate 80% without it
Objectives
- Stabilize patient
- Gastric decompression while treating for shock
-Needle decompression (18-14 g)
-Trocar
-Stomach tube (measure it!). Do not want to pass through necrotic tissue. - Oxygen therapy
-Nasal insufflation
-Mask
-Blow-by
Methods
1. IV fluids
2. Antibiotics
3. Oxygen
4. Correct electrolyte and acid-base imbalance
5. Gastric decompression as needed
6. ECG to monitor for cardiac arrhythmias
Decompression apparatus (does not mean de-rotation) Surgery still required
-60cc syringe
-Three-way stopcock
-Extension tube
-18 g needle
- Summarize the clinical findings in a classic case presentation for a dog with Gastric Dilatation and Volvulus, and relate each clinical sign to its potential cause.
Physical exam findings
-Abdominal pain at palpation, distention, tympany.
-Splenomegaly
-Clinical signs of shock: weak peripheral pulse, tachycardia, prolonged CRT, Pale MM, dyspnea.
Differential diagnosis
-Simple gastric dilation in puppies
-Small intestinal volvulus
-Primary splenic torsion
-Diaphragmatic herniation
-Ascites
You can not differentiate GDV from Simple Dilation just because you can pass a stomach tube
- Given a classic presentation for a dog with Gastric Dilatation and Volvulus, name the two radiographic views recommended to evaluate the stomach and make a radiographic diagnosis.
History
-Progressively distending and tympanic abdomen
-Painful: arched back, restless, grunting, panting
-“dog sitting” back end down, can’t get comfortable
-Hypersalivation
-Nonproductive retching
-Dyspnea
-Restlessness
-Atypical: may just not be doing ok as usual.
Radiographs
-Decompress before radiographs
-Take Right Lateral and Dorsoventral Radiographs
-Reverse C or Double Bubble
-Free abdominal air suggests gastric rupture
-Be cautious, gentle moving or may cause vomiting, unstable patient.
- Identify predisposing factors associated with the development of Gastric Dilatation and Volvulus in the dog.
Predisposing factors:
Deep Chested, Large-breed dogs
-Male gender
-Eating once a day
-Eating rapidly
-Stress
-Large volume feeding
-Increasing age
-Aerophagia (sucking air)
-Fearful temperament
-Anatomic predisposition: having a deeper thorax and narrower thorax
-Ileus
-Trauma
-Vomiting
-First Degree relative with GDV
-Dry food with oil and fat as main 4 ingredients
-Atmospheric influence in military working dogs
GDV Surgical procedure, Instruments
Instruments
-Foal nasogastric tube and stomach pump
-Suction machine and sterile tubing
-Poole suction tip
-Laparotomy pads
-“Spay pack”
-Balfour retractor
-TA Stapler
Procedure
-Initial assessment of gastric viability
-Gastric decompression
-Gastric derotation
-Abdominal exploratory
Assess vascular supply to the spleen
-Splenectomy if indicated
-Palpate the stomach, run the bowel, and assess other vicar.
-Check for torsion of gastrosplenic ligament
-Gastropexy
What arteries commonly rapture during GDV?
What are some key surgical anatomy aspects to remember?
-Short gastric arteries: derived from the splenic artery and supply the greater curvature of the stomach
-Blood loss
-Gastric infraction/necrosis
-Gastroepiploic (greater curvature) and gastric (lesser curvature) arteries derive from the celiac artery and supply the stomach
-80% arterial blood flow is to the mucosa, 20% is to the muscularis and serosa.
-Mucosal color alone is not a reliable indicator of gastric viability
Color of Seromucosal Layer
-Red to purple: consider viable
-Green to black: probably non-viable
-Palpate thickness: thin antrum and fungus = necrotic
-Bleeding is good in response to incision
Partial Gastrectomy and TA/GIA stapler
Gastropexy Technique
-If necrosis involves the esophagus = GAME OVER
-Remove all non-viable tissue
Gastropexy
-Recommend incisional gastropexy
-3-5 cm incision through the seromuscularis
-8-10 cm from the pylorus in avascular area of the pyloric antrum
-3-5 cm incision in the right ventrolateral abdominal wall caudal to the last rib
Always check if the gastric incision will reach the selected area of the abdominal wall before making that incision
-Drive the needle from the inside edge of your seromuscular layer incision out will minimize the chance for accidental needle entry in to the lumen of the stomach
-Continuous closure preferred
-Absorbable monofilament suture
Common Post-GDV Complications & Post-Operative Care
What is the prognosis?
- Cardiac arrhythmias VPC: ventricular premature contractions
- Shock
- Hypokalemia
- GI motility abnormalities
- Gastric necrosis
- Peritonitis
- Recurrent dilation
- Anemia
Other complications
-Acid-base disturbances
-Pancreatitis
-DIC
-Hepatic or renal failure
-Incisional dehiscence
-Intestinal volvulus/intessusception
-Esophagitis-Megaesophagus
Post Operative Care
-Continuous IV fluid 24-48 hours
-Electrolytes monitoring, supplement K if needed
-Low fat food
-Blood work
-EKG 75% arrhythmias occur post-op
-Antibiotics: cefazolin, ampicillin, gentamicin
Monitor for
-Gastric necrosis/peritonitis 2-5 days post-op
-Dehiscence 3-5 days
-Hypoalbuminemia
-Anemia
-Cardiac Arrhythmias: correct hypokalemia first (may interfere with lidocaine) Lidocaine CRI (toxicity signs: muscle tremors, vomiting, seizures)
-Most serious complications occur within 72 hours
Prognosis
-Poor if delayed surgery, necrosis present, perforation.
Increase survival by: early tx, aggressive fluid therapy, gastric decompression, early surgery.
Client education, prophylactic gastropexy.
Lecture 3
Some Anatomy
Cardia: esophagus enters stomach at the cardiac ostium
Fundus: dorsal to the cardiac osmium, small in carnivores, usually gas filled.
Body: middle 1/3 lies against the left liver lobes
Pyloric antrum: funnel-shape, opens into the pyloric canal
Pyloric canal
Pyloric Osmium: end of pyloric canal that empties into the duodenum
Hepatogastric ligament: portion of the lesser omentum that passes from the stomach to the liver.
How much does the mucosa account for of the stomach’s weight? = 1/2
Mucosa easily separated from submucosa and serosa
Perioperative Concerns
- Vomiting Animals * Dehydration
- Hypokalemia
- Aspiration pneumonia * Esophagitis
- Alkalosis – secondary to gastric fluid loss (may see metabolic acidosis)
*Hematemesis–may indicategastricerosion or (coffee grounds vomit) ulceration, but may also indicate a coagulopathy - Peritonitis from gastric perforation/rupture
- Withholding Food
- Normally ≥ 8 to 12 hours prior to surgery
- ≥ 18 hours (preferably 24) prior to gastroscopy
- 4 to 6 hours in pediatrics when hypoglycemia is a concern
- Surgery for gastric obstruction, distension, malpositioning, or ulceration should be performed as soon as the patient has been stabilized.
- Perioperative antibiotics may be used if the gastric lumen is to be entered however, this may not be necessary if
- Normal immune function
- Simple gastrotomy
- Proper aseptic technique
- No spillage of gastric contents
- List three steps taken when performing a gastrotomy to prevent contamination of the abdomen by gastric contents.
Where should you place the gastric incision?
Hypovascular area of the ventral aspect of the stomach, between the greater and lesser curvatures
-Ventral midline approach (exploratory celiotomy)
-Use Belfour retractors
-Perform exploratory before incising the stomach
-Isolate the stomach with moistened laparotomy pads
-Place stay sutures: assist with manipulation, prevent spillage of gastric contents.
-Make sure incision is not near the pylorus
- Given a Billroth I or a Billroth II surgery list and describe its individual component surgical procedures.
Indications for a Billroth I
-Neoplasia: 1-2 cm margins of normal tissue should be removed with abnormal tissue
-Outflow obstruction caused by muscular hypertrophy
-Ulceration of the gastric outflow tract
- Gastroduedenostomy
- Pylorectomy
Billroth II
-Neopplasia
-Outflow obstruction
-Ulceration of the gastric outflow tract
- Gastrojejunostomy
- Partial Gastrectomy (including pylorectomy)
-Distal stomach and proximal duodenum are closed after pylorectomy and the jejunum is attached with a side-to-side anastomosis
Y-U Plyroplasty
-Allows greater accessibility for the resection of the pyloric mucosa in dogs with mucosal hypertrophy
-Increase the luminal diameter of the outflow tract
Definitions
-Splenomegaly: enlargement of the spleen for any cause
-Splenectomy: surgical removal of the spleen
-Splenosis: congenital or traumatic presence of multiple nodules of normal splenic tissue in the abdomen
-Siderotic plaques: brown or rust-colored deposits of iron and calcium on splenic surface
-Splenorrhaphy: suturing of a raptured spleen
-Hemangiosarcoma (HSA): malignant neoplasm arising from blood vessels
-Hemangioma: benign tumors of dilated blood vessels
-Hematoma: swelling or mass of blood (usually clotted) confined to an organ, tissue, or space caused by seepage or any reason.
