Surgery of the stomach Flashcards
1
Q
What are the (general) treatment options for foreign bodies?
A
- Stabilize the patient FIRST (don’t stop the vomiting)
- Fluids/lytes/analgesics
- Gastroprotectants
- Specific therapies (toxins)
- FB removal options:
- Conservative
- Endoscopy
- Gastrotomy
- Induce emesis
2
Q
What are the indications for conservative management of foriegn body ingestion?
A
Patient consumes something small and benign (not sharp) that is likely to just pass through
3
Q
How is endoscopy used and when is it indicated for foreign body removal? What about gastrotomy?
A
- Endoscopy: use graspers on scope for small, regular FBs
- Can’t use for sharp objects (i.e., bone)
- Gastrotomy: open up stomach and remove object
- Large or sharp objects (unable to be removed via endoscopy)
4
Q
When should you induce emesis following a foreign body ingestion?
A
Toxins–want to get rid of them ASAP
(Also small objects that could cause obstruction if passed through)
5
Q
What are some examples of specific therapies for FB ingestion?
A
Lead: chelation with EDTA
Zinc: transfusion
6
Q
What are the predisposing factors for gastric foreign body?
A
- Younger animals (“not as smart”)
- Previous history of FB ingestion
- Conditions that predispose to PICA (eating everything)
- Pancreatic exocrine insufficiency
- Hepatic encephalopathy
- Iron deficiency
7
Q
What are clinical signs associated with gastric outflow obstruction?
A
- Intermittent vomiting
- Dietary modification alters signs
- Normal to decreased body condition
- Abdominal distension but no pain
8
Q
What are the causes of gastric outflow?
A
- Congenital pyloric stenosis
- Acquired outflow obstruction
- FBs
- Chronic hypertrophic pyloric gastropathy
- Neoplasia
- Inflammatory/infiltrative disease
- Motility disorders
- Ulceration with scarring
- Extraluminal masses
9
Q
Describe the blood supply to the stomach
A
R and L gastric arteries
Greater curvature: epiploic arteries
Fundic area: nerve bundle/fibers–gastric pacemaker (initiates normal contractions); avoid gastrotomy incision through pacemaker
10
Q
Differentiate between congenital and acquired pyloric stenosis
A
- Congenital
- Hypertrophy of circular muscles
- Brachycephalic breeds (Boston terrier)
- Siamese cats (rare)
- Etiology unknown (excess gastrin?)
- Signs start at weaning
- Acquired
- Chronic hypertrophic pyloric gastropathy
- Stress major factor (along w/ any drug that mimics CNS)
- Mucosal and/or muscular hypertrophy
- Usually both tissue layers affected (unlike congenital)
- Small breeds–Lhaso apso, Shih Tzu
- Excitable or vicious
- Middle aged males
- Chronic hypertrophic pyloric gastropathy
11
Q
What pathology is associated with congenital and acquired pyloric stenosis?
A
Hypertrophy of the muscular layer of the pylorus (and/or mucosal layer for acquired); etiology is unknown (excess gastrin?)
12
Q
Is pyloric stenosis the same in cats and dogs?
A
Not completely
- Both species have vomiting as the major sign
- Cats can also have regurgitation due to secondary esophagitis and esophageal dysfunction
13
Q
Which digestive hormone has been implicated in the etiology of both congenital and acquired pyloric stenosis?
A
Gastrin
14
Q
What diagnosis modality can be used to differentiate congenital and acquired pyloric stenosis? How?
A
Ultrasound
- Congenital
- Layer thickness
- Differentiate neoplasia
- U/S confirms diagnosis
- Acquired
-
Pyloric wall and muscle thickness
- Muscularis < 4mm
- Pyloris < 9mm
-
Pyloric wall and muscle thickness
15
Q
What are the pathological classifications of acquired pyloric stenosis?
A
- Grade 1 = muscular hypertrophy
- Rare
- Can look like congenital (use age + signalment to differeniate)
- Grade 2 = muscular and mucosal hypertrophy
- Most common
- Grade 3 = mucosal hyperplasia and muscular and submucosal inflammation
16
Q
What are the specific goals of surgical correction of acquired pyloric stenosis? What treatments are available?
A
- Goal: reduce stenosis/increase gastric outflow
- Treatments
- Transverse pyloroplasty
- Y-U pyloroplasty
- Billroth 1
- Biopsy
17
Q
What is a Fredet-Ramstedt pyloromyotomy? What are the advantages/disadvantages?
A
- 2cm incision through seromuscular layers of pylorus
- Advantages
- Quick and easy
- Lumen unopened–no risk of spilling abdominal contents
- Disadvantages
- Congenital pyloric stenosis only
- Stenosis may reoccur
18
Q
What is a Heineke-Mikulicz pyloroplasty? What are the advantages/disadvantages?
A
- (Transverse pyloroplasty)
- 3-5cm full thickness, going into lumen
- Suture transversely–will significantly widen pyloric area
- Simple interrupted or continuous
- Advantages
- Mucosa exposed–can take biopsy
- Reoccurrence unlikely
- Disadvantages
- Lumen opened–risk of abdominal spillage
- Not usually effective with acquired pyloric stenosis (usually only works with grade 1)
19
Q
What is a Y-U pyloroplasty? What are the advantages/disadvantages?
A
- Transport antral wall to pyloric region–>wider pylorus
- Advantages
- Will resolve grade 2 (most common)
- Allows mucosal resection
- Disadvantages
- Shortens gastric emptying time
- Must avoid hepatoduodenal ligament as can damage common bile duct
20
Q
What is the Billroth 1 procedure? What are the advantages/disadvantages?
A
- Complete removal of the pylorus (pylorectomy with gastroduodenostomy)
- Very severe grade 3’s
- Advantages
- Abnormal tissue completely removed
- Larger increase in gastric outflow
- Disadvantages
- Technically difficult–much more advanced/complicated
- Longer procedure
- Increased risk of leakage
21
Q
Where should gastrotomy incisions for exploration and removal of FBs be made? Why?
A
- Ventral midline approach from xyphoid to pubis
- Want to avoid vessels in the lesser curvature of the stomach that might be hit if you don’t stay along midline
- Want to avoid gastric pacemaker
- Stab incision in center of vessels
22
Q
What are the principles/goals of suturing a gastrotomy incision? What factors influence closure choices?
A
- Submucosa is the holding layer–apposition of submucosa results in strong closure
- If you can invert the tissue (serosa-serosa contact) you can form a fibrin seal that will aid in a water-tight closure (required)
- Reduced gastric volume or tissue pliability complicate closure
- Closure technique is influenced by the pathology (if any) in the stomach wall and surgeon preference
23
Q
What are the indications for a gastrectomy?
A
- Neoplasia
- Ischemic injury (GDV)
- Ulcer
- Trauma
24
Q
What are the advantages/disadvantages of suturing the stomach with inverting suture patterns?
A
- Advantages
- Will allow fibrin seal formation which facilitates water-tight closure
- Disadvantages
- Impossible to do with very thickened walls
- Don’t get submucosa-to-submucosa contact (though should still be strong enough)
- Will not use in resection situations–length of stomach wall has already been shortened enough
25
Differentiate between the Cushing, Lembert, and Connell suture patterns
* Cushing = goes through submucosa but doesn't go through mucosa or into the lumen
* Connell = same as Cushing but goes full thickness
* Lembert = double inverting
26
T/F: 60-70% of all gastric neoplasias are gastric adenocarcinomas
TRUE
27
What is the signalment of gastric adenocarcinomas?
* 2.5:1 male:female
* 7-10yrs
* Rare in cats
* Rough collie, Staff terrier, Belgian shepherd
28
What are the physical findings/pathology for gastric adenocarcinomas?
* Usually found at pyloric antrum and lesser curvature
* Metastasis--regional LN, liver
* Diffuse, thickened, and non-distensible
* Linitis plastica (leather bottle stomach)
* Ulcerated mucosal plaques
* Discrete polyploid
29
What are the treatment options for gastric adenocarcinomas?
* Aggressive surgical excision (\> 5cm margins, remove regional LN for staging/biopsy)
* Palliative bypass procedure (non-resectable obstructive lesions)
* Chemotherapy (?)
* Gastrectomy
* Billroth 1
* Billroth 2
* Cholecystoenterostomy
30
What is the prognosis for gastric adenocarcinomas?
Poor, even with sx treatment
31
What is the signalment for leiomyosarcomas?
Usually middle aged--approx. 7yrs
32
What are the physical findings of leiomyosarcomas?
* Smooth muscle origin
* More common in cardia vs. pylorus
* Single or multiple
* Often ulcerate into gastric lumen
33
What is the prognosis for leiomyosarcomas?
MST = 21mo
Have high metastatic potential
34
What is the signalment for leiomyomas?
* Often in older patients (\> 15yrs)
* Very slow growing
* Often incidental finding
35
T/F: Leiomyomas are benign
TRUE
36
What is the treatment and prognosis for gastric leiomyomas?
* Gastrotomy approach
* Submucosal resection --\> resect tumor and take minimal margins --\> good to go
* Prognosis = good--resection eliminates all signs
37
What is the signalment of pythiosis?
* Young, large breed working dogs
* Southeast U.S. (gulf states)
38
What are the clinical signs of pythiosis?
* Wt. loss
* Vomiting
* Diarrhea
* Hematochezia
* Sometimes palpable abdominal mass and increased mesenteric lymph nodes
39
T/F: Pythiosis has a slow growth rate but an extensive nature
FALSE--has a fast growth rate
40
What does pythiosis infiltrate?
Submucosa and muscularis layers of stomach and small intestines
41
How can you diagnose pythiosis (oomycosis/pythium insidiosum)?
* Endoscopy--difficult to find organism
* Histo
* Eosinophilic pyogranulomatous inflammation
* Deep tissue samples of fibrotic material can reveal organism
* ELISA tests for P. insidiosum antibodies
42
How is pythiosis treated? What is the prognosis?
* Surgical excision with 3-4cm borders
* Combined with medical treatment
* Itraconazole and terbinafine
* Immunotherapy--P. insidiosum vaccine
* Monitor for recurrence w/ ELISA 2-3mo post-op
* Prognosis: guarded to poor
43
What is a Billroth II gastroenterostomy? When is it indicated?
* Remove part of the proximal duodenum and stomach (gastrojejunostomy)
* Indicated when resection of the stomach is so proximal to limit end to end anastomosis
* Allows extensive gastrectomy without tension on suture
44
What are some complications of the Billroth II procedure?
* Alkaline gastritis (bile and pancreatic secretions flow into stomach)
* "Blind loop" syndrome--gastric contents move orally and putrefy
* Marginal ulceration--ulceration of jejunal mucosa (not used to seeing acidic contents)
45
What is the difference between acute gastric dilation, chronic gastric volvulus, and acute gastric dilation + volvulus?
* Acute gastric dilation
* **No volvulus seen**
* Distended stomach but in a **normal position**
* Chronic gastric volvulus
* Slight malposition
* Vomiting and eructation
* Gastropexy
* Acute GDV
* Distension of the stomach and **rotation** of the stomach on its mesenteric axis
* Surgical disease
* Also called gastric torsion
46
What are the predisposing factors for GDV?
* Large/giant breeds (G. dane, St. Bernard, S. poodle)
* Deep chested dogs
* Inc. depth to width ratio
* Harder to eructate
* 1st degree relative
* Faster eating
* Larger volumes daily
* Raised food bowls
* Post prandial activity
* Fats and oils
* Restricting water before/after feeding
* Age--ligaments
* Post splenectomy (?)
* Underweight dogs
* Intact females
* Males \>\> females
* Temperament
47
What foods decrease the risk of GDV?
Eggs or fish--very easily digested proteins
48
What is the pathophysiology leading up to gastric dilation and volvulus (GDV)?
* Distension from gas/fluid
* Distension alters pyloric/esophageal sphincter position
* Limited eructation and bacterial fermentation causes further distension
* Further distension --\> body of stomach rotates clockwise along the long axis of the esophagus
* Rotation of the body causes pylorus to rotate cranioventrally from right to left
* Pylorus will rest along the left body wall on top of the esophagus and the gastric body to the right
49
What are the 2 types of rotation in GDV?
* Clockwise
* **Much more common**
* 70-360 degree rotation
* Greater omentum covers stomach
* Counterclockwise
* Limited to 90 degree rotation
* Greater omentum will not be visible
50
What are the cardiovascular effects of GDV?
* Increased intra-abdominal pressure
* Compression of low pressure veins
* Cd vena cava, portal and splenic veins
* Poor venous return
* Decreased preload, perfusion, CO and BP
* Patients go into shock--need fluids ASAP
* Catecholamines
* Vasoconstriction--\>dec. perfusion
* Tachycardia, tries to inc. BP
* Arrhythmias (40-50%)
* Myocardial hypoxia
* Metabolic acidosis--\> dec. contractility
* Myocardial depressant
* Reperfusion
51
What are the respiratory effects of GDV?
* Gastric distension--\>impingement on diaphragm
* Decreased excursions
* Dec. tidal volume
* Inc. CO2
* Resp. acidosis
52
What are the GI effects of GDV?
* Vascular compromise of stomach mucosa
* Mucosal hemorrhage and necrosis
53
What are the metabolic effects of GDV?
* Poor tissue perfusion
* Cellular hypoxia
* Anaerobic metabolism
* Inc. lactate
* Metabolic acidosis
* Liver/kidney buffer
* Convert lactate to pyruvate
* Organs compromised from poor perfusion
* Compounds acidosis
54
What are the immune effects of GDV?
* Source of pathogenic bac. is GIT
* Hypoxemia--\>mucosal ischemia
* Loss of protective barrier
* Bacterial translocation
* Damage to mucosal-assoc. lymphatics (ischemia from obstruction)
* Portal hypertension--compromised reticular endothelium
55
What are the renal effects of GDV?
* Profound vasoconstriction attempting to increase blood pressure decreases GFR
* Oliguria/anuria
* Acute renal failure
56
What is reperfusion injury? What is its role in GDV?
* Tissue flow absent, then returned when GDV is corrected
* Anaerobic metabolism
* Accumulation of waste products + toxic oxygen radicals
* Toxins released into general circulation
* Capillary permeability
* Altered vascular tone
* Platelet activation
* Vascular occlusions
* Fever
* Negative inotrope
* Neutraphils
* No reflow phenomenon
57
What are the clinical signs of GDV?
* Distended painful tympanic abdomen
* Active retching
* Hypersalivation
* Tachypnea
* Tachycardia
* Collapse
58
How do you diagnose GDV?
* Signalment (large breed dogs 10mo-14yr)
* History
* Looking/biting abdomen
* Preying posture
* Non-productive retching
* Distended abdomen
59
When you perform radiographs for a GDV patient, what is the patient's position and what are the findings?
* **Do not perform until medical stabilization**
* Do NOT take a VD view--may predispose to reflux and aspiration
* **Right lateral is most diagnostic**
* Gastric dilation with compartmentalization
* Malposition of pylorus
* Double bubble
60
In which direction does the stomach most commonly move with GDV?
Clockwise
61
What is the most common presentation for a GDV (rotation of stomach) and how is it confirmed?
* 180 degrees clockwise rotation most common
* Can confirm rotation is clockwise because the omentum will be covering the stomach (isn't visible in the counterclockwise direction)
62
What are the key components of pre-operative stabilization of GDV patients (in the correct order)?
* Goal is to stabilize CV, resp, and renal systems initially
* Fluids
* Crystalloids 45-90ml/kg IV
* Crystalloids 10-40ml/kg + colloids 10-20ml/kg/day **increases survival**
* 7% hypertonic saline
* **Blood sample**
* Decompression
* Pain management
* Antimicrobials and free radical scavengers
* Sx and post-sx treatment
63
What are free radical scavengers (examples) and what is their potential benefit in treating GDV?
* Free radical scavengers
* Acetylcysteine
* Vitamins C and E, selenium
* Deferoxmaine--ferric iron chelator
* Lidocaine--also drug of choice if VPCs develop and provide analgesia
* Scavenger of ROS
* Help to prevent reperfusion injury
64
What methods can be used to decompress the stomach?
* Orogastric intubation
* Usually try first, may require sedation
* Trocharization
* Done when unable to pass orgastric tube
* Emergency gastrostomy
65
Why is the stomach decompressed prior to GDV sugery?
* Improves CV and resp function
* Done prior to surgery because the more stabilized patients are when they go into sx, the better off they'll be
* \*Perform AFTER fluid/volume support
* Can cause CV instability from endotoxins
66
How do you perform orogastric decompression?
* Stiff but flexible large bore tube with bite block
* Nose to last rib
* Gavage pump
* 2 buckets
* Lubricate tube
* Blow in tube to help through esophageal sphincter (but do NOT force it)
67
How do you perform trocharization decompression?
* 10-14g catheter or needle
* Clip and sx prep 6cm patch in cranial abdomen
* Find tympanic area
* Insert catheter firmly
* Gently decompress
* Remove when stops
68
When/how do you perform an emergency gastrotomy for treatment of GDV?
* If unable to decompress by OG tube or trocharization and other surgical treatment must be delayed
* Requires sedation and local block over right paracostal region
* 10cm skin incision through abdominal muscle
* Isolate stomach and suture stomach to incision on abdominal wall
* Incision into stomach
69
What treatment is used for GDV (other than surgical)?
* Oxygen therapy
* Helps offset poor ventilation
* Pain control
* Drugs with minimal CV effect
* Correct electrolyte/acid-base imbalances
* **Glucocorticosteroids contraindicated--NEVER give to GDV patients**
70
T/F: Arrhythmias occur in 40-50% of GDV patients and can contribute to mortality
TRUE
Usually VPC's
71
What causes VPCs in GDV patients?
* Etiology is unknown
* Myocardial hypoxia decreases CO and tachycardia decreases coronary blood flow
* Metabolic acidosis decreases myocardial contractility and CO
* Myocardial depressant factor--cellular ischemia from decreased organ perfusion and (-) inotropic effects
* Reperfusion injury compromises cardiac function
72
What are the advantages of early surgical correction in the management of GDV?
* May complete surgery before arrhythmias emerge
* Gastric repositioning improves bloodflow
73
Which area of the stomach is most commonly affected by vascular compromise?
Greater curvature
(Gastric necrosis occurs in 10% of GDV patients)
74
How is gastric necrosis due to GDV managed? How does this affect prognosis?
* Partial gastrectomy
* Techniques
* Cut and sew
* Stapling
* Partial invagination
* Ligate vessels
* Remove necrotic tissue
* **Significantly worsens prognosis**
75
How is viability of the stomach typically assessed?
* Peristalsis--dead stomach wall loses its ability to contract
* Serosal color
* Pink/red = good
* Black, green, gray = bad
* Palpate for thinning or friability
* Pulsation of vessels
* Bleeding cut surfaces suggests that blood supply to the area is still viable
76
How is intestinal viability typically assessed?
* Peristalsis
* **Important**
* If moving = (probably) still alive
* Pinch test: see if it stimulates contraction
* Color: pink, glistening = good
* Pulsation of mesenteric vessels
* Bleeding of cut surface
* Wall thickness and texture
* Fluorescin infusion
* Woods lamp shows fluorescence if blood supply patent
* Oximetry probe--check for oxygenation and perfusion
77
What are the goals of a gastropexy?
* Prevent volvulus from recurring
* \> 50% recurrence rate normally
* **Does not prevent dilation**
* Provide relatively anatomic position for pylorus
78
What abnormalities in the spleen can occur with GDV and how are they treated?
* Venous congestion--usually self-limiting
* Vessel thrombosis--splenectomy
* Splenic torsion--splenectomy if severe
* Can usually detorse and it will return to normal
* If clots, reperfusion, and platelet circulation spleen will appear black = dying --\> splenectomy
79
What is the technique for an incisional gastropexy?
* **Most common**
* 3-6cm incision right ventro-lateral wall
* Perpendicular to and 6-8cm lat to celiotomy
* Through peritoneum and T. abdominal m.
* Incision pyloric antrum/stomach
* Serosal and muscular layer
* Suture far incision first
* Suture 2/0 or 3/0 abs
80
Describe the technique for a belt loop gastropexy
* Parallel incisions 2cm apart to create tunnel
* Right abdominal wall
* **Peritoneum**/muscle
* Parallel 4cm incisions 3cm apart through serosa/muscular near pyloric antrum
* Base at G. curvature
* Pull suture through 'belt loop' incision on abdominal wall
* Creates **very good adhesion--strong and effective**
81
What is the technique for a circumcostal gastropexy?
* Create tunnel around right 11th-12th rib
* **Must palpate--**don't want to go into thoracic cavity (BAD)
* Create stomach flap with base near **lesser** curvature
* Suture with 2/0 or 3/0
* **Very strong**
82
Describe the technique for a tube gastropexy/gastrostomy
* Incision through R abdominal wall caudal to last rib
* Purse string suture in stomach
* 14-20 fr foley or mushroom tip catheter
* Suture tube to pyloric antrum area with mattress sutures
* Suture stomach to abdominal wall
* Secure with a finger trap
* Inflate with saline
* Tube is clamped and bandaged; usually removed in 5-10days
* Heals by second intention
* Advantages: prevents recurrent dilation, allows feeding
* Disadvantage: not as strong as other methods (but usually strong enough)
83
What is the technique for an incorporating gastropexy?
* Stomach wall incorporated into linea alba incision (celiotomy incision)
* **Not recommended**--surgical nightmare if you have to go back into the abdomen later--stomach and adhesions in the way
* **Only indicated** if patient requires abrupt discontinuation of anesthesia (crashing/complications)
84
How is a laparoscopic-assisted gastropexy performed?
* Dorsal recumbency
* 2 ports
* Camera port--midline
* Instrument port--R abdominal wall
* ID pyloric antrum
* Grasp with laparoscopic Babcock forceps
* Extend working port incision to exteriorize stomach
* Place stay sutures in stomach
* Confirm orientation of stomach
* Perform incisional gastropexy
* Advantage: less invasive, can be done prophylactically
* Disadvantage: need equipment, not done to treat GDV
85
How is an endoscopically-assisted gastropexy performed?
* Use endoscope to find pyloric antrum
* Manipulate to R ventral lateral abdomen
* Will see light through skin
* Place stay suture
* Make incision and perform incisional gastropexy
86
When is the most critical time period for postoperative GDV patients? Why?
The 1st 4 days post-op are the most critical--when 95% of deaths following GDV occur
87
When do GDV-associated arrhythmias usually occur?
12-36hrs after presentation
Usually VPCs and will subside 24-72hrs after surgery
88
When should GDV-associated arrhythmias be treated?
* Associated w/ weakness or syncope
* Persistent tachycardia \>150bpm
* Pulse deficits or poor pulse quality
* Multifocal VPCs
* Will not always treat--drug of choice is lidocaine (can be arrhythmogenic and problematic)
89
How are GDV-associated arrhythmias treated?
* Lidocaine is drug of choice for initial management
* Bolus 1-2mg/kg IV q5min
* CRI (maintenance)
90
What is the prognosis for GDV patients?
* 10-33% mortality rate
* One of the leading causes of death in large/giant breed dogs
* Can correlate duration and severity of signs with survival
* Recumbant patients = higher mortality
* 44x more likely to die
* \< 10% recurrence rate w/ gastropexy (very high w/o it)
91
Explain the prognosis-based lactate levels of GDV patients
* Lactate \> 6mmol/L = higher incidence of gastric necrosis
* 50% mortality w/ gastric necrosis
* Lactate \< 6mmol/L = 99% survival
* Lactate \> 6mmol/L = 58% survival
* Percentage changes in lactate in response to treatment may be a better indicator of survival rates
