GI Flashcards
List and briefly explain 7 possible causes of perineal hernias in dogs
There are many proposed causes of perineal herniation in the dog. These include:
1) rectal abnormalities (rectal deviation, rectal diverticulum- likely a result of herniation but contributes to straining and further weakening of the pelvic diaphragm)
2) The effect of androgens (predominantly observed in intact males; neutering significantly decreases the chance of recurrence)
3) Gender-related anatomic differences (the female pelvic diaphragm is larger, broader and stronger than that of males)
4) Relaxin hormonal effect (affects collagen metabolism, causing relaxation and stretching of inelastic tissues. Affected dogs have higher expression of relaxin receptors within the pelvic canal)
5) Prostatic disease (Observed in 25 to 50% of dogs with perineal hernias. Possible due to prostatomegaly leading to increased abdominal pressure during urination, caudal displacement of the prostate or periprostatic cysts.
6) Testicular disease (observed in 69% of dogs with perineal hernias – cause-effect no established)
7) Neurogenic atrophy (neurogenic atrophy of the coccygeus and levator ani muscles due to nerve damage to the muscular branches of the pudendal and pelvic nerves. Possibly resulting from a degenerative neurogenic myopathy. Tenezmus from prostatic enlargement has been suggested as the cause of traction applied to the sacral plexus nerves.
A patient presents with a large perineal hernia. He is also unable to urinate. You perform a paracentesis and obtain fluid similar to urine, suggesting urinary bladder retroflexion into the hernia. How can you determine if the fluid is really urine?
Compare creatinine and potassium levels to that of peripheral blood. These values should be about twice as high in the urine.
You can also perform a positive contrast retrograde urethrocystogram
Vessels and nerves that must be preserved while performing a perineal herniorrhaphy
Internal pudendal and caudal rectal vessels
Caudal rectal nerve
What two major veins form the portal vein?
Cranial and caudal mesenteric veins
What are the major tributaries to the portal vein after its formation by the confluence of the cranial and caudal mesenteric veins?
Splenic, gastroduodenal and right gastric vein
What structures are drained by the portal vein?
“collects blood from the pancreas, spleen, and the entire gastrointestinal tract except the caudal rectum and anal canal. ”
Excerpt From
Miller’s Anatomy of the Dog
Howard E. Evans & Alexander de Lahunta
https://books.apple.com/us/book/millers-anatomy-of-the-dog/id875302085
This material may be protected by copyright.
Describe the blood supply to the maxilla and mandible
Maxilla: blood supply originates from the common carotid arteries. Paired major and minor palatine arteries emerge from the major Palatine foramen on the caudal edge of the fourth upper premolar. Major palatine arteries course rostrally, anastomosing caudal to the incisors. The minor palatine arteries enter the palate at the level of the last molar, caudal and slightly lateral to the major palatine foramen. The minor palatine arteries course caudomedially and ramify in the caudal hard palate and soft palate. The soft palate is also supplied by branches of the ascending pharyngeal artery.”
Mandible: the mandibular alveolar artery enters the mandibular canal on the medial surface of the mandible and ends at the middle mental foramen, where it branches to form the caudal, middle and rostral mental arteries which exit via the mental foramina.
What is known as the Von Langerbeck technique? What is the main disadvantage? What age consideration should be taken into account? What technique can be used instead and why?
“The two procedures most often used to repair secondary clefts are sliding bipedicle flaps and overlapping flap techniques. Sliding bipedicle flaps (von Langenbeck technique) are created to close hard palate defects. The disadvantage of this technique is that the repair is unsupported and directly over the defect. Staged repair can be done to increase coverage of palatal defects.
“Palatoplasty performed before 16 weeks of age may hinder maxillofacial growth and development. Although rare, a narrower maxilla and occlusal problems may result. ”
“An alternate technique for repair of hard palate defects is the overlapping “sandwich” technique (Figs. 18.19 and 18.20). This technique is advantageous because it does not place the repair over the palate defect.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What muscle must be apposed/included in the correction of a primary palatal defect to avoid premature dehiscence?
Orbicularis oris
Which axial pattern flap is considered the most robust choice for the repair of palatal fistulas ?
Angularis oris artery (A branch of the facial artery)
What mucosal flap technique is preferred for the repair of large, centrally located palatal fistulas? how is it performed?
Double flap technique
“A double-layer flap technique may be performed using tissue surrounding the fistula and a flap from the mucoperiosteum of the hard palate. Create the first flap (gingival dashed line) by rotating the gingival margins of the fistula medially and apposing with sutures (top inset). Cover this flap (bottom insert) with a rotational mucoperiosteal hard palate flap (palatal dashed line).”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What technique can be used in cats for the repair of small palatal fistulas?
Conchal cartilage graft repair
What cartilage based technique can be utilized for the repair of small, centrally located palate defects in dogs?
Vertical ear canal graft repair
Name 4 drugs associated with the development of esophageal strictures
“tetracycline, doxycycline, nonsteroidal antiinflammatory drugs, or ciprofloxacin”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Following injury caused by foreign body, what is the process by which an esophageal stricture will develop?
“To produce a stricture, esophageal damage must generally involve the muscular layers and affect most of the circumference in a focal area. The mucosal defect is then replaced by epithelial migration. The gap in the muscle is filled by fibrous connective tissue, and wound contraction and collagen remodeling reduce the width of the scar. This leads to narrowing of the esophageal lumen, which may cause obstruction.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
In what part of the esophagus are strictures most likely to be observed?
Lower 1/3 (high pressure zone)
Name 8 possible differentials for regurgitation other than esophageal strictures
“Vascular ring anomalies, extraluminal masses, esophageal neoplasia, foreign bodies, esophagitis, gastroesophageal intussusception, esophageal diverticulum, hiatal hernias, megaesophagus, and cricopharyngeal dysfunction are other possible causes of regurgitation that must be differentiated from esophageal stricture.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What are the two techniques most commonly utilized in the treatment of esophageal stricture’s?
Ballon dilation or bougienage
Explain the difference between a pulsion diverticulum and a traction esophageal diverticula
“A pulsion diverticulum is a herniation of the mucosa through the muscular layers of the esophagus. These diverticula are produced by exaggerated intraluminal pressure in association with abnormal regional peristalsis or when obstruction interferes with normal peristalsis. “The wall of a pulsion diverticulum consists of only esophageal epithelium and connective tissue.”
“Traction diverticula are distortions, angulations, or funnel-shaped bulges of the full-thickness wall of the esophagus caused by adhesions resulting from an external lesion. “The wall of a traction diverticulum consists of adventitia, muscle, submucosa, and mucosa.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What are the two most common sites for esophageal diverticula ?
Distal cervical esophagus cranial to the thoracic inlet or distal thoracic esophagus just cranial to the diaphragm
Diagnostic test most commonly utilized to diagnose esophageal strictures an diverticula
Esophagogram
What two conditions (1 pathologic and another breed related) can be misdiagnosed as esophageal diverticula?
“Dogs and cats with generalized megaesophagus tend to have greater outpouching of the esophageal wall cranial to the base of the heart. Brachycephalic dogs and shar peis often have a loop of redundant esophagus cranial to the base of the heart. Do not misdiagnose these animals as having diverticula.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
List three methods by which an esophageal diverticula might be surgically treated
“Position a thoracoabdominal (TA; linear) or GIA (gastrointestinal anastomosis) stapling device along the base of the diverticulum and fire. Transect and remove the diverticulum without contaminating the surgical site. If stapling equipment is not available, suction the esophageal lumen and place noncrushing forceps across the proposed transection site. Transect the diverticulum and appose the edges as for esophagotomy with a one- or two-layer simple appositional pattern”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What parasite is associated with the development of esophageal masses similar to neoplasia? What clinical findings may also be observed in these patients?
Spirocerca lupi
Intermediate host is a beetle which must be ingested for infection to occur.
Hypertrophic osteopathy maybe observed
Best diagnosed via CT scan or esophagoscopy