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.
What are the differential diagnosis of acute appendicits?
If there is a classic presentation:
Mesenterics adenitis, Meckel’s diverticulitis, Crohn’s diease, mesenteric embolus and right sided diverticulitis.
If atypical presentation need to consider:
Abdo: cholecysitis, gastroenteritis, pancreatitis, perfortaed DU, obstruction, diverticulits, non-specific abdo pain
Urinary: pyelonephritis, renal colic, cystitis
Gynae: salphingitis, ectopic, degenration fibroid, mitelschmerz, PID
Extra abdominal: referred pain from herpes zoster, lower lobe pneumonia, right sided testicular torsion
What aree the complications of an appendcectomy?
Wound infection
Intra-abdominal collections
Prolonged ileus
Fistula between the appendix stub and the woun
DVT, PE, pneumonia and atelectasis
Late: incisional hernia, adhesional obstruction
How does an appendix mass form?
Omentum and small bowel adhere to the inflammed appendix.
Usually 2-5 days after the onset of symptoms
need to treat conservatively - iv fluids, analgesia, antiboitics
carry out appendicetomy after 3months
What is an appendix abscess?
An appendix mass that continues to enlarge due to the appendix perforating within it.
The patient will be pyrexial and tacycardic.
It needs to be drained or removed.
What conditions need to be present for a closed loop large bowel obstruction to occur?
There needs to be a competent ileo-caecal valve. The gas can still pass through the valve but go back the otherway, so there are 2 points of obstruction. The caecum gets bigger and bigger and risks perforation.
What factors increase the risk of a pseudo-obstruction?
Trauma, severe infection, sugery, sepsis, metabolic abnormalitis, and drugs.
hypokalamia, hyponatreamia, uremia, TCAs
What happens to form a sigmoid volvulus?
The bowel twists on its mesentry.
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
What are the aetiological factors for anorectal abscesses?
Idiopathic
Crohn’s disease
Anarectal cancer
Anal fissure
Anal trauma/ surgery
Pelvic abscesses may arise secondary to IBD or diveritculitis
What percentage of patients with an anorectal abscess develop a anorectal fistula?
30 - 60%
What organisms are normally responsible for anorectal abscesses?
Gut - bacteroides fragilis, E.Coli, or enterococci
occasionally its staph aures from the skin
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.
What differentials need to be considered when someone presents in persistent drainage of pus, blood or fecal matter consistent with a ano - in - fistula?
Pilonidal sinus
Hidradenitis suppurativa - abscess in groin and armpits
incontinence
Crohn’s disease
trauma
What is the position of most anal fissures?
Posterior - anterior ones follow partuirtion normally.
usually due to hard faeces and then it causes discomfort so defecation becomes difficult causeing a vicious circle. Spasm may constrict the inferior rectal artery causing ischemia and making healing difficult.
What is a pilonidal sinus?
Obstruction of natal celft hair follicles approx 6cm above the anus with in growing of the hair causing a foreign body reaction and resulting in secondary tracking
What is the differential diagnosis for rectal bleeding?
Haemorrhoids - blood on toilet paper, dripping blood into the toilet
Fissure - blood on the toilet paper and pain
Carcinoma of the rectum - blood streaked on stool, blood and mucous on defecation
Colon cancer - bleeding assocaited with change in bowel habit and abdo pain
Diverticular disease - can be large amounts
IBD
Ischemic colitis - hx of CVD, pain and bleeding
Angiodusyplasia
Colitis (infectious)
Rectal prolapse
Meckel’s diverticulum
Intersussecption
aortoenteric fistula
massive GI haemorrhage
What are the differences between diverticulosis, diverticular disease and diverticulitis?
Diverticulosis is the presence of diverticula in the bowel. They are out pouchings in the gut wall that normally occur at hte site of entry of perforating arteries.
Diverticular disease suggests that patients are symptomatic. They often have lower abdominal pain relieved by defecation, nausea and flatulence.
Diverticulitis occurs when there is an inflammation of the diverticulum. Patients have abdominal pain, normally in the LIF, fever, diarhoea or constipation. Riased WCC and CRP.
How is acute diverticulitis treated?
NBM, IV fluids, antibiotics, analgesia
Do AXR and erect CXR to check for obstruction and perforation.
Where are the majority of diverticulum found?
simoid colon with 95% of complications occuring there.
What are the complications of diverticular disease?
Perforation - patients present with ileus and shock. A hartmanns procedure may need to be carried out.
Haemorrhage - sudden and painless.
Fistulae - enterocoloic, colovaginal, or colovesical
Abscesses - swinging fever, leucocytosis and localising signs
Post infectious strictures
What is angiodysplasia?
Submucousal ateriovenous malformations.
Present as PR bleeding in the elderly.
70-90% of lesions occur in the right colon, it is not know why they develop.
They can be treated with coagulation under direct visulisation at colonscopy or angiography, if there are extensive areas patients might need a colectomy.
What is pruitius ani?
An itch around the anus. Caused by the anus being moist or soiled, fissures, poor hygeine, thread worm, dermatoses, lichen sclerosis, anxiety and contact dermatitis.
Describe the two types of rectal prolapse
Type 1 = muscosa only
Type 2 = all the layer (the more common)
Incontinence is present in 75% of prolapses.
Is due to lax sphinchter - prolonged straining, chronic neurological conditions and psychaitric illness.
What is a Meckel’s diverticulum?
A remnant of the omphalomesenteric duct.
Present in 2% of population, is 2 inches long and is located 2 feet from the ileoceaceal valve.
Can present with:
Inflammation and perforation - mimicking an appendicitis
Rectal bleeding from ulceration - can have gastric mucosa lining it producing acid
Intestinal obstruction from intusssception
Due to a tumour
If you suspect a sigmid volvulus but the xray is not consistent what further imaging can you do?
water soluble contrast study - shows a birds beak sign where the lumen of hte colon is tapered.
What symptoms would make you think a stomach volvulus was occuring?
vomiting, pain and failed attempts to pass NG tube.
Reguritation, dysphagia and noisy gastric peristalisis may also occur in chronic volulus.
Risk factors: Congential - paraoesphageal hernia, congenitlal bands, bowel malformations, pylric stensois.
Acquired - gastric surgery
What is the treatment of sigmoid volvulus?
NBM
IV fluids
Fluid balance monitoring
Bloods and Xmatch
Erect CXR and AXR
Decompression with rigid sigmoidoscipy and insertion of a flatus tube
What medical treatment can be used for anal fissures?
laxatives, topical lcoal anasethetics, 0.2% GTN ointment
What are haemorroids?
Enlarged vascular cushions - NOT varicose veins
In what position are haemorroids normally found?
3, 7 and 11 o’clock
What are the indications for surgery in Crohn’s disease?
Bowel perforation
Massive hamorrhage
Colonic dilatation
Failure to respond to medical treament
Complicated fistula
Bowel stricturing and obstruction
Failure to thrive in children
How are haemorroids classified?
1st degree - remain in the rectum
2nd degree - prolapse through the anus on defecation but spontaneously reduce
3rd degree - as for second degree but need digital reduction
4th degree - remain persisitently prolapsed
They can also be internal (from the plexus above the dentate line) or external ( from the plexus below the dentate line) or moxed.
What are the treatment options for haemorroids?
Injections - 2-3mL of phenol in almond oil into the submucosa.
Rubber band ligation
Cryosurgery
photocoagulation
haemorroidectomy - in resistat to treament and 4th degree.
What is happening when haemorrhoids get painful?
They have thrombosed - normally painless due to no sensory fibres abve the dentate line.
What are the indications for surgery in UC?
Failure to respnd to treatment
Toxic dilation of the colon
Haemorrhage
Imminent perforation
Dysplasia on colonscopy
Can perform a subtotal colectomy, a proctectomy with a permanent ileostomy, or create an ilioanal pouch.
