Lower GI Flashcards
What are the three different types of irreducible hernia?
Incarcerated: adhesions between the sac and the contents, but no obstruction or interference with blood supply. the hernia will simply not reduce. Obstructed: A hollow viscus is trapped within the sac and obstruction occurs. This is a common cause of small bowel obstruction. Strangulated: The arterial blood supply to the contents of the sac is compromised. If surgical relief is not taken the contents will become gangrenous.
List some aetioloigcal factors for acquired hernia:
Loss of tissue strength and elasticity Surgical trauma Enlargement of a foramen ( enlarged oesophageal hiatus allowing development of a hiatus hernia) Nerve damage causing weakness of the muscles (development of an inguinal hernia post appendicecotmy due to damage to the ilio-inguinal nerve)
Describe an indirect inguinal hernia
A peritoneal sac protrudes through the deep inguinal ring and down the inguinal canal. Due to a persistent processus vaginalis.
Describe a direct inguinal hernia:
It is acquired. There is a defect in the anterior abdominal wall in Hesselbach’s triangle:
ingunial ligament inferiorly, inferior epigastric artery laterally, and lateral border of rectus muscle medially.
Weakness in transversalis fascia in the posterior wall of the inguinal canal.
Need to check other side as often bilateral.
On examination how can you tell an indirect from a direct inguinal hernia?
Inguinal hernias are above and medial to the pubic tubercle.
When applying pressure over the inguinal ring (1cm above the midpoint of the inguinal ligament) if the hernia appears medial to the point of pressure it is likely to be direct. if the hernia only appears when pressure is relased from the inguinal ring it is likely to he indirect.
What are the complications of a hernia repair?
Recurrence in 2%.
infection, ilioinguinal nerve entrapment, testicular ischemia (higher incidence in repair of recurrent herniae)
Describe a femoral hernia
A defect in the transversalis fascia overlying the femoral ring at the entry to the femoral canal. It passes through the femoral canal and bulges below and lateral to the pubic tubercle.
More common in females and higher risk of strangulation.
What are the boundaries of the femoral canal?
Anterior: inguinal ligament
Posterior: superior ramus of the pubis and pectineus muscle
Medial: body of pubis, and pubic part of the inguinal ligament
Lateral: femoral vein
Describe an umbilical hernia
Occurs because of incomplete closure of the umbilical orrifice. More common in afro caribbeans.
Only operate if still present at 3yrs and defect is >1.5m in diameter.
What are the borders of the inguinal canal?
Floor: Inguinal ligament
Roof: fibres of tranvsersailas and inferior oblique muscles
Anterior: external oblique
Posterior: transvesalis fascia
Describe a paraumbillical hernia:
Just above or below or to the side of the umbilicus.
More common in females - main factors are mutliple preganancies and obesity
Commonly contains omentum, then transverse colon and then small bowel.
Describe an epigastric hernia:
Protrusion through the linear alba in the upper part of the abdomen.
Generaly only contains extraperitoneal fat.
Describe an Richter’s hernia:
Just affects the bowel wall, not the whole loop.
The gangrenous area can reduce spontaneously and then perforate at a later date resulting in peritonitis
Describe a spigelian hernia
A hernia through the linear semilunaria at the lateral border of the rectus sheath.
Usually a hands breadth above the pubic symphysis at the level of the linear semicircularis - where the posterior rectus sheath becomes deficient and all aponeurosis of the abdominal muscles pass infront of the rectus muscle.
requires surgical repair
What is a Littre’s hernia?
A hernia that contains a Meckle’s diverticulum in the sac
Describe an obturator hernia
A hernia that occurs through the obturator foramen.
it is diffcult to feel as it occurs deep to pectanieus.
May result in pressure on the obturator nerve causing referred pain down the medial side of the thigh - Howship Romberg sign.
Where do lumbar hernias protrude through?
One of two places:
Grynfeltt’s space (superior lumbar triangle):
roof: external oblique, floor: transversalis fascia, medial edge: quadratus lumborum, lateral edge: internal oblique
Petit’s triangle (inferior lubar triangle)
Anterior: external oblique, posterior: lat doris, inferior: iliac crest, floor: internal oblique.
often mistaken for lipomas
What is an umbilical lymph node called?
Sister Mary Joseph’s node - associated with cancer of the stomach, colon, ovary or breast.
What are the differentials for a lymph in the groin?
Inguinal ligament
Femoral ligament
Hydrocoele of the cord
Hydrocoele of the cnal of Nuck
Lipoma
Undescended testicle
Ectopic testicle
Saphena varix
Iliofemoral aneurysm
lymph nodes
psoas abscess
What are the causes of small bowel obstruction?
Luminal causes: gallstone ileus
Wall causes: congenital atresia, crohn’s disease, tumors (lymphoma or carcinoma)
Outside of the wall: herniae, adhesions, intussusception, volvulus
What are the symptoms and signs of small bowel obstruction?
Colicky abdominal pain - cannot get comfortable
vomiting and constipation - symptoms depend on how high the obstruction is
distension (especially with low obstruction), tympanitic abdomen and high pitched bowel sounds.
Pyrexia, tachycardia, and continuus pain may indicate that strangulation has occured.
AXR: distended loops of small bowel, centrally - if erect can show air/ fluid levels. Absent or diminished colonic gas. Valvulae conniventes seen.
How do you manage small bowel obstruction?
Drip and suck - IV fluids and NG tube and NBM.
surgery if: strangulatig obstruction, drip and suck has not resolved the obstruction.
What are the symptoms and signs of an appendicitis?
Central abdominal pain with nausea that moves to the RIF after 8ish hours. Vomiting is uncommon and is diarrhoea.
The pain in the RIF is made worse by moving, jumping, coughing, laughing.
May have a low grade temp and be slightly tachycardic.
Tender in the RIF over McBurney’s point. Rovsing’s +ve (pain in RIF when press in the LIF). Psoas sign (pain on extending hip). Cope sign (pain on flexion and internal rotation of right hip)
WCC raised and CRP raised.
Where do anal abcesses usually arise from?
The cryptoglandular epithelium - lines the anal canal.
They can be:
Perianal - hair follicle or sebaceous gland,
Ischiorectal - in the ischiorectal fossa
Intermuscular - between the internal and external spincters. The internal sphincter is breached through the crypts of Morgagni.
or Pelvirectal - spreading from a pelvic abcess
How are fistula - in - ano classified?
Subcutaneous
Submucous
Low anal - below puborectalis
High anal - opening in close relation to the anorectal junction
Pelvirectal - penetrating levator ani
How would you determin the course of an ano fistula?
Goodsall’s rule:
If the external opening lies anterior to a line drawn straight across the centre of the anus the track will pass radially throigh a straight line towards the interal opening .
If the extrnal opening lies posterior to the transverse line the track will curve in a horse shoe mannor to open in the midline posteriorly.
