Hernias Flashcards
congenital hernia locations
- umbilical
- inguinal
- scrotal
- femoral
- peritoneal-pericardial diaphragmatic
- hiatal
traumatic/acquired hernia locations
- abdominal
- incisional
- diaphragmatic
3 parts of the hernia
- The ring: defect in the wall
- The sac: peritoneum lining the hernia contents
- Contents: organ/tissue that has moved into the hernia ring
What is a true vs false hernia?
True hernia = w/ peritoneal lining
False hernia = no peritoneal lining
why are incarcerated and strangulated hernias considered non-reducible?
Incarcerated = adhesions have formed which prevents reduction Strangulated = blood supply to a herniated organ is compromised
what makes up the internal inguinal ring?
internal abdominal oblique + inguinal ligament + rectus abdominis
what makes up the external inguinal ring?
longitudinal slit in aponeurosis + external abdominal oblique muscle
structures in the inguinal canal
- genital branch of genitofermoral a., v., n.
- external pudendal vessels
- spermatic cord (m)/ round lig(f)
what other congenital abnormalities are associated with umbilical hernias?
- cryptorchid
- peritoneal-pericardial diaphragmatic
- ventricular septal defect
umbilical hernia sx
- incision avoiding hernia contents
- Amputate hernia sac
- Reduce contents
* do at same time as spay/castrate - Close ex. rectus sheath
what dog breed is predisposed to scrotal hernias?
chondrodystrophic dogs esp. Shar peis
emergency sx of traumatic hernias is indicated when…
- animal cannot be adequately stabilised due to hernias
- herniated organs progressively turgid or incarcerated
- penetrating wounds explored after emergency resus
what is the most important strength layer when closing the ventral abdominal wall?
external rectus fascia
77-85% of traumatic diaphragmatic hernias are due to?
blunt force - automobile accidents, kicks, falls
PE findings assoc. w/ a diaphragmatic hernia
- resp. signs and exercise intolerance
- muffled or asymmetric thoracic auscultation
- hyporesonance (pleural effusion)
- hyperresonance (gastric tympany)
how can traumatic diaphragmatic hernias lead to cardiac dysrhythmias?
ventilation perfusion mismatch
all patients experiencing significant trauma should get what radiograph?
a lateral thoracic and abdominal rad.
radiographic findings w/ thoracic hernia
- partial loss of the normal line of the diaphragm
- obscured or displaced cardiac shadow
- abdominal viscera w/in the thoracic cavity
- cranial displacement of pylorus or duodenum: traction on gastro-hepatic ligament
which diaphragmatic muscles are usually ruptured in a thoracic hernia?
costal muscles (85% unilateral)
what precautions do you have in mind when ventilating a dog w/ chronic diaphragmatic herniation?
- do not force reinflation – barotrauma, re-expansion pulmonary oedema + reperfusion injury risks
- thus low pressure ventilation
approach to repair a thoracic hernia?
ventral midline coeliotomy w extension to median sternotomy
closure technique of thoracic hernias
- debride sparingly
- interrupted sutures aid in reconstruction
- simple cont. pattern best = min. suture materials and fewer stiff cut ends
- start dorsally and progress ventrally
- correct pneumothorax w/ thoracostomy tube
indications for AB in post-op tx of a traumatic diaphragmatic hernia
- liver herniation
- perforation of the GIT
what is a congenital PPDH?
congenital peritoneo- pericardial-diaphragmatic hernia
= communication btwn abdomen and pericardial sac
concurrent defects assoc. w/ PPDH
- sternal defects
- cranial midline abdominal wall hernia
- umbilical hernia
- intracardiac defects (VSD)
breeds predisposed to PPDH
Weimaraners and cocker spaniels
thoracic rad findings of congenital PPDH
- enlarged cardiac silhouette
- dorsal elevation of trachea
- overlap of heart and diaphragmatic borders
- discontinuity of diaphragm
- gas-filled structures in pericardial sac
+/- sternal defects
prognosis of PPDH w/ surgical correction
excellent UNLESS re-expansion/reperfusion pulmonary oedema (poor)
define type 1 hiatal hernia
sliding protrusion through oesophageal hiatus of gastroesophageal junction +/- gastric fundus
breeds predisposed to hiatal hernias
shar peis, bulldogs, brachys
CS of hiatal hernias
- regurgitation
- oesophagitis, megaO
- v+, haematemesis, anorexia, weight loss (poor BCS)
cause of hiatal hernia
an anatomical oesophageal hiatal malformation - loose connection w/ diaphragm
sx treatment of hiatal hernias
dorsal hiatal herniorrhaphy
post op support of hiatal hernias
- Metoclopramide: sensitizes upper GIT to acetylcholine –> inc. prssure of gastro-oesophageal junction + a prokinetic
- Erythromycin: increases lower oesophageal sphincter pressure and stim. migrating motility complexes + peristalsis
- PPIs
- Anti-emetic: maropitant/ondansetron
- No food for 12h post op
erythromycin dose as GIT support
1mg/kg q8h slow IV over 30min
metoclopramide dose
1mg/kg IV
2mg/kg/hr CRI
