The Abdominal Wall Flashcards
What is a hernia?
the protrusion of an organ or part of an organ through a defect in the wall of the cavity containing it, into an abnormal position
What is a reducible hernia?
Contents can be completely replaced into the cavity
What is an irreducible hernia?
contents of the hernia cannot be completely replaced into the cavity
What is an obstructed hernia?
Bowel contents cannot pass through the herniated bowe
What is a strangulated hernia?
There is ischaemia of the contents of the hernia (due to obstructed venous return), which unless relieved will lead to gangrene and perforation
What is an incarcerated hernia?
The contents of the hernia sac are stuck inside by adhesios
How are patients with hernias managed?
hernia tried to be reduced to prevent obstruction/strangulation
If hernia is irreducible, elective surgery ‘Lichtenstein repair’ mesh technique
Describe surgial repair of hernias
Open or laparoscopic (both generally offered), true indications for laparoscopic repairs are bilateral or recurrent
Done as day case
If obstructed/strangulated, an emergency Hartmann’s procedure is performed
How are hernias in children managed?
Herniotomy and ligation of the processes vaginalis about the age of 1 year
What is the inguinal canal formed by?
Relocation of the testes during foetal development
About 4cm long and lies parallel and medial to the first part of the inguinal ligament
What does the inguinal canal contain?
Three arteries: testicular/ovarian artery, artery to the vas deferens, cremasteric
Three nerves: genital branch of genitofemoral, ilioinguinal and sympathetic nerves
Three other structures: Vas deferens, round ligament of the uterus, pampiniform plexus and testicular lymphatics
What are the three fascial coverings of the inguinal canal?
Internal spermatic fascia (from the transversals fascia)
the cremasteric fascia (from internal oblique fascia)
The external spermatic fascia (from external oblique fascia)
Where is the deep inguinal ring?
1cm superior to the midpoint of the inguinal ligament.
midpoint: halfway from ASIS to PT
What is the entrance to the inguinal canal?
Deep inguinal ring
What is the exit from the inguinal canal?
Superficial inguinal ring
Where is the superficial inguinal ring found?
1cm superior and lateral to the pubic tubercle
What are the boundaries of the inguinal ligament?
MALT
Superior 2muscles - internal oblique and transversals abdominus
Anterior: 2 aponeuroses: aponeuroses of ext/internal oblique
Inferior: 2 ligaments (inguinal ligament/lacunar ligament)
Posterior wall: 2 Ts (transversals fascia, conjoint tendon)
What is an indirect inguinal hernia?
(congenital)
Contents of the hernia pass through the inguinal canal due to a patent processes vaginalis
Who gets indirect inguinal hernias?
Young patients
What is an indirect hernia covered by?
Processus vaginalis and all three fascial coverings
Exits the superficial ring inside the cord, frequently passing into the scrotum / labia majors
Why are indirect hernias more likely to strangle than direct hernias?
Superficial ring is not dilated
How do direct inguinal hernias occur?
Contents pass through a weakness of the anterior abdominal wall in the inguinal triangle
What is the cause of direct inguinal hernias?
Due to factors increasing intra-abdominal pressure (chronic cough, straining at micturition/defecation, heavy lifting, smoking)
Make up 1/3 inguinal hernias
What are direct hernias covered by?
peritoneum and transversalis fascia, as they lie outside the inner coverings of the cord
How are hernias diagnosed?
Generally clinical examination is sufficient, and further not necessary
Can use USS
How is the difference between hernias made?
in theatre: Inferior epigastric arteries demarcate MEDIAN edge of the superficial ring
Indirect hernia passes LATERAL to these vessels
Direct hernia is MEDIAL to these vessels
Which types of hernia are more common in which sex?
Inguinal hernias are more common in males, with indirect hernias affecting a younger population
Femoral hernias are more common in women than men, however the most common type of hernia in a women is indirect
What is the femoral triangle formed by?
Inguinal ligament superiorly, medial border of the sartorious laterally and lateral border of adductor longs medially
What are the contents of the femoral triangle?
Femoral nerve, femoral artery and femoral vein from lateral to medial:
NAVY (nerve to Y fronts medially)
What is the femoral sheath?
Inferior prolongation of the transversals/iliapsoas fascia that passes deep to the inguinal ligament to allow the passage of the femoral artery/vein into the femoral triangle
Where does the femoral canal lie?
At the medial extremity of the femoral sheath, and is the site of femoral hernia
How does a femoral hernia occur?
the bowel exits the abdominal cavity through the femoral ring, a week point in the anterior abdominal wall
As the hernia enlarges, it can pass out of the saphenous opening and into the deep fascia
Femoral opening is relatively small - high risk of obstruction/strangulation
What is a Richter’s hernia?
A hernia involving only one sidewall of the bowel and not the bowel lumen, which can result in bowel strangulation and perforation without causing obstruction or any of its warning signs
Particularly likely in the femoral sac
What is the presentation of a patient with a femoral hernia?
50% = surgical emergency, due to obsctructed contents, with the others presenting as a globular lump below and lateral to the pubic tubercle
What are the differentials for a lump in the groin?
Inguinal hernia Lipoma Femoral artery aneurysm Saphenous Ovarix Psoas abscess Lymph node
What is the cause of a true umbilical hernia?
Defect in the transversals fascia at the umbilical ring (where the umbilical vessels passed), specifically incomplete closure of the umbilical cicatrix
Covered by skin
In which babies are umbilical hernias more common?
Black, male, premature babies
What are the symptoms of umbilical hernias?
Generally asymptomatic, more prominent on coughing, laughing but reducing easily and rarely becoming obstructed
At what age should repair be considered?
If still present at 2 years old (90% retract by the age of 2)
What is a paraumbilical hernia?
An acquired hernia that occurs just above/below the umbilicus
Caused by raised IAP, so more common in obese, middle aged, multiparous women
What is the presentation of paraumbilical hernia?
Localised dragging pain and enlarging hernia over time
Often tender with colic from intermittent obstruction of the bowel
Mainly reducible, but due to the small neck, they commonly stranglate/obstruct
What is the surgical management of paraumbilical hernias?
Early operative management
Excision of the sac and stitching of the rectus sheath (Mayo’s operation)
Mesh repairs for larger defects
What are the risk factors for incisional hernia?
Pre-op factors: old age, poor nutrition sepsis, uraemia, jaundice, obesity and steroids
Operative factors: Vertical incision, knots that are too loose/too tight and presence of drains
Post-op factors: post operative ileus, coughing and obesity all increase IAP, and wound infection slows the healing process
What are the symptoms of incisional hernia?
Bulge in the scar and local discomfort
Subacute bowel obstruction = common as the hernia enlarges
There is usually a wide neck so strangulation is generally uncommon
BUT as contents accumulate,, adhesions often develop so the hernia becomes irreducible (with obstruction, strangulation then more likely)
How is surgical repair of incisional hernia done?
Dissecting out the hernia and then individual closure of each abdominal layer
What is the recurrence risk of incisional hernia?
small - 2-5%
Large - 10-20%
What are the common presenting features of epigastric herniae?
One or more small protrusions through the linea alba above the umbilicus, usually only containing extraperitoneal fat
Over 75% may be asymptomatic, but some are surprisingly painful with the pain worse on physical exertion or after meals
How is an epigastric hernia managed if there are symptoms of pain?
Surgially - indicates some degree of strangulation of the peritoneum
What is a diversification of the rectus muscle
Where the rectus muscles do not meet in the midline at the linea alba, and thus split apart when the patient flexes the abdominal muscles (such as doing a sit up)
Common in obese men, parous women and people with chronic raised IAP
No indication for surgical management
