GI II Flashcards
He is taken to theatre and an EUA demonstrates the presence of a fistula to the abscess cavity. The abscess is situated to the left and posterior to the anus (5 o’clock position in the lithotomy position).
Where would you expect the internal opening to be located?
Directly posterior to the centre of the anus (6 o’clock)
Goodsall’s rule for fistula in ano states that if the external opening of a fistula lies behind a line drawn transversely across the anus the track should curve in a horseshoe manner towards an internal opening in the midline posteriorly.
If the external opening is in front of the transverse anal line the track tends to pass radially in a straight line towards the internal opening.
Gastroscopy and H.Pylori test
The rapid urease biopsy or Campylobacter-like organism (CLO) test is often used to test for Helicobacter pylori at endoscopy.
Histological biopsies are frequently obtained at the same time as the CLO.
Serology and breath tests may be performed independently of the endoscopy, for example, in the GP surgery or clinic.
A 76-year-old man presents with weight loss, dark urine, and pale stools which are difficult to flush away.
An excess of which of the following would account for this history?
The history is suggestive of obstructive jaundice. In this condition there is an excess of conjugated bilirubin in the plasma which is water soluble and can be excreted in the urine.
Reduced stercobilinogen causes the typical pale stools.
Unconjugated bilirubin is strongly bound to albumin and is not water soluble so is not excreted in the urine.
Urobilinogen is formed from stercobilinogen that escapes into the plasma from the colon and is colourless.
Blood supply to sigmoid colon
The blood supply to the sigmoid colon being predominantly from the inferior mesenteric artery (IMA).
We are therefore looking for the stem which describes the anatomy of the IMA. The coeliac, superior mesenteric artery (SMA) and IMA are ventral branches of the aorta arising at T12, L1 and L3 respectively.
Sigmoid volvulus
The loop of sigmoid colon has a classical bean shape, with the apex over the S2/3 junction in the left iliac fossa with the loop of sigmoid colon distending covering the liver and descending colon.
The most important feature of a sigmoid volvulus rather than a large redundant distended loop of sigmoid colon is the absence of haustra.
splenic rupture
High impact injuries to the left flank may cause damage the spleen or kidney as well as the ribs and soft tissue. If there are fractured ribs and the patient is hypotensive suspect rupture of the spleen.
If the patient responds to fluid resuscitation, an ultrasound can be arranged to confirm the diagnosis. If there is a subcapsular haematoma but no free rupture this may be managed conservatively.
If the patient remains hypotensive then a laparotomy is indicated.
Renal trauma rarely renders the patient hypotensive unless other organs are also injured, and more force would be required for aortic dissection.
Small bowel obstruction due to inguinal hernia
The history is consistent with small bowel obstruction secondary to an irreducible inguinal hernia (above and medial to tubercle).
This x ray actually shows a loop of small bowel leading towards the position of an inguinal hernia. The concern here is that the bowel is ischaemic and is at risk of perforation, which would put the patient at significant risk. Initial management should then aim to prepare him for emergency surgery on the day of presentation.
Bowel obstruction is initially managed by a ‘drip and suck’ approach. A nasogastric tube is placed to remove the stomach contents and prevent vomiting. Intravenous fluids are prescribed to make up the deficit from losses and provide maintenance requirements. The patient is allowed nil by mouth both to prevent vomiting and in preparation for surgery.
Ideally, patients are fluid resuscitated and optimised before theatre. CT scans are often obtained to get a more accurate picture of the intra-abdominal pathology.
sigmoid volvulus
The x ray shows the classical appearance of a sigmoid volvulus. A volvulus is defined as a rotation of an organ around its mesentery.
The sigmoid is the commonest site (75%) followed by caecum, transverse colon and splenic flexure. The stomach, gallbladder and small bowel may also be affected by the process.
Sigmoid volvulus is associated with chronic constipation and is not infrequent in institutionalised patients taking psychiatric or neurological medications, such as treatment for Parkinson’s disease.
It is far more common in Africa than the West.
colon cancer
Elderly patients with per rectal bleeding, change in bowel habits, and weight loss should be considered to have colonic cancer unless proven otherwise. Increase in age is a risk factor for developing colonic cancer. The other risk factors, among others, include
A family history of colon cancer
Familial adenomatous polyposis
Diet rich in red meat
Longstanding ulcerative colitis or Crohn’s disease.
The clinical presentation of patients with colonic malignancy depends on the site of the tumour.
Right-sided colonic carcinoma commonly presents with
Anaemia Tiredness Malaise Pallor Loss of weight. The left sided colonic carcinoma presents with
Change in the bowel habits
Bleeding per rectum
Intestinal obstruction.
Rectal carcinoma, in addition to the features seen in left-sided colonic carcinoma, is associated with a sense of incomplete evacuation of the bowel (tenesmus). Tumours of the caecum affecting the ileocaecal valve can also present with symptoms of lower small bowel obstruction.
Investigations for suspected colonic malignancy include
Full blood cell count
Renal function and electrolytes
Liver function tests (to rule out hepatic involvement)
Plain x ray of the abdomen
Ultrasound and CT scans.
Carcinoembryonic antigen (CEA) is the commonly used tumour marker to diagnose colonic malignancy and subsequently to assess the progress, including recurrence.
Surgery remains the mainstay of management of colonic tumours. Radiotherapy and chemotherapy have their roles in selected patients. A temporary or a permanent colostomy is frequently required following the surgical treatment of left-sided colonic tumours.
Crohns disease
The precise aetiology of Crohn’s disease remains unclear, however
An altered response by the body's immune system to normal intestinal bacteria Smoking Environmental factors Familial predisposition Pathogenic bacteria Viruses have all been implicated.
The most common presentation of patients with Crohn’s disease is related to a chronic inflammatory process involving the ileocaecal region which includes low-grade fever, loss of appetite, weight loss, anaemia and general fatigue.
The patients may have crampy or constant pain over the umbilical region or over the right iliac fossa. The pain may be relieved by defecation. Diarrhoea may be troublesome. This is usually non-bloody and intermittent. If the colon is involved, patients may present with diffuse abdominal pain accompanied by mucus, blood and pus in the stool. Perianal fissures or fistulae may be present.
Acute exacerbation of Crohn’s disease affecting the terminal ileum (terminal ileitis) may be difficult to differentiate from acute appendicitis, although the symptoms associated with Crohn’s disease tend to be of insidious onset.
Abdominal ultrasound, small bowel enemas and CT scan may help to establish the diagnosis. However, if the diagnosis remains uncertain and the patient becomes clinically unstable, a laparotomy may be indicated.
The management of Crohn’s disease depends on the severity and the stage of the disease. The treatment may be conservative (including medical) or surgical. Some important complications of Crohn’s disease include
Fistula formation (for example, entero-colic, entero-cutaneous)
Abscesses (for example, perianal)
Haemorrhage
Intestinal obstruction.
bowel cancer tumour pathology
The cyclin-dependent kinase inhibitor p27 is a negative regulator of the cell cycle and a potential tumour suppressor gene. Its down regulation is associated with occurrence of sporadic colon cancer.
ß-catenin accumulation, not suppression, initiates adenoma formation.
p53 is a tumour suppressor gene.
Activation of K ras oncogene is seen in sporadic colon cancer.
Bcl-2 is an oncogene first described in haemotological malignancies but also implicated in other malignancies such as breast and prostate. Its up regulation makes cells resistant to apoptosis.
Expression may be affected in colon cancer but it is not considered one of the key mutations in the tumourigenesis of sporadic colonic adenocarcinoma.
Cholangitis
Cholangitis is an acute infection of the biliary tree due to obstruction of the common bile duct, which subsequently becomes infected. The causative organisms are usually gut-derived coliform bacteria.
Obstructions result from:
Strictures
Stenosis
Tumours
Following endoscopic retrograde cholangiopancreatography (ERCP).
Cholangitis is treated with intravenous fluid resuscitation and broad-spectrum antibiotics while awaiting sensitivities from blood culture.
Emergency ERCP and decompression of the common bile duct is usually necessary to relieve the obstruction and to allow the drainage of pus from the bile ducts.
Left untreated the mortality from cholangitis is 100%.
Modified Glasgow score for pancreatitis
Acute pancreatitis is associated with alcohol or gallstones in more than 80% of patients, although the ratio of these two causes has a wide geographical variation. Gallstone disease predominates in the UK.
Acute pancreatitis is usually self-limiting, however 15-20% of patients develop severe acute pancreatitis (pancreatic necrosis and associated cytokine activation), which results in multiple organ dysfunction syndrome if not aggressively treated. Early identification of patients with a severe attack allows prompt treatment.
The modified Glasgow criteria are used to predict patients with severe acute pancreatitis and include:
Age >55 years Albumin 10 mmol/L Calcium 600 U/L Urea >16 mmol/L White cell count >15 ×109/L. Severe disease is present if three factors are detected within 48 hours.
oesophageal cancer and dysphagia
Patients with oesophageal cancer tend to present late with progressive dysphagia, weight loss and anaemia.
Oesophagectomy is reserved for early cancers which have not invaded locally.
Traditionally malignant dysphagia was treated with repeated endoscopic dilatations.
Endoscopic placement of self-expanding metal stents (SEMS) are now placed most frequently in patients presenting with malignant dysphagia. Early complications of SEMS are
Malposition Oesophageal perforation Bleeding Stent migration. Late complications are most frequently related to eating (food bolus) or tumour overgrowth.
Initially, management of a food bolus blocking a stent is for the patient to consume a fizzy drink, which helps to break up the food bolus, otherwise endoscopy is required to dislodge the food bolus.
mallory-weiss tears
Mallory-Weiss tears occur in the region of the gastro-oesophageal junction from forceful or prolonged coughing or vomiting, often after excessive alcohol intake. They may also be caused by epileptic convulsions. These tears result in vomiting bright red blood or by passing blood per rectum (melaena). Although bleeding can be profuse, it usually stops spontaneously.
Aortoduodenal fistula results from erosion of the duodenum into the aorta due to tumour or previous repair of the aorta with a synthetic graft.
Meckel’s diverticulum occasionally occurs in the ileum and may contain ectopic gastric mucosa, which may result in rectal bleeding.
Oesophageal varices represent dilated venous collaterals and result from portal hypertension in patients with liver cirrhosis.
Bleeding from peptic ulcers is the commonest cause of upper gastrointestinal bleeds. Mucosal erosions develop, commonly due to non-steroidal anti-inflammatory drugs, steroids or prolonged alcohol abuse.
pilonidal abscess
A sacrococcygeal pilonidal sinus is an inflammatory condition associated with hair producing a sinus.
Pilonidal abscesses are usually found in or adjacent to the midline close to the natal cleft. Pilonidal disease is more common in Caucasian males in their third decade of life. Generally the condition is more common in obese or hirsute individuals.
Pilonidal abscess are treated with incision and drainage procedures at the time of presentation, a more definitive procedure (for example, excision) is required if the disease becomes non-healing or recurrent.
Perianal and ischiorectal abscesses result from infection of the anal glands found in the intersphincteric space.
femoral hernia
This patient has developed a small bowel obstruction. The most likely diagnosis is an obstructed femoral hernia, as the irreducible lump in the left groin arises below and lateral to the pubic tubercle. An inguinal hernia would produce a lump above and medial to the pubic tubercle.
Femoral hernias are the third most common hernia with a male to female ratio of 1:4, with the hernia occurring most frequently in elderly multiparous women. All femoral hernias should be repaired, as 40% are strangulated on first presentation.
Erythema of the overlying skin occurs in strangulation and is a sign of poor outcome.
Obturator hernias are very rare and do not usually present with a lump.
perforated peptic ulcer
The classic presentation of a perforated peptic ulcer is a sudden onset of epigastric pain and peritonitis (usually upper abdominal).
In elderly patients, especially on steroids, there may be an absence of symptoms and signs initially.
The diagnosis is aided by the signs of gas under the diaphragm on an erect chest radiograph, although this may be absent. Radiological investigations where water-soluble contrasts are given orally also aid the diagnosis, but may also be negative if the ulcer has sealed.
The risk factors for peptic ulceration include
Non-steroid anti-inflammatory drugs
Steroids
Helicobacter pylori infection.
The optimum management is resuscitation, laparotomy and repair of the ulcer with an omental patch, and peritoneal lavage.
wilsons disease inheritance
Wilson’s disease which is inherited in an autosomal recessive fashion due to a mutation on the long arm of chromosome 13
UC
The patient has ulcerative colitis. The presence of distended small bowel loops would suggest incompetence of the ileocaecal valve, indicating right colonic involvement.
There is often constipation proximal to the inflammed bowel. The distal limit of contipation provides a crude estimate of the proximal limit of colonic inflammation.
Tachycardia
Hypoalbuminaemia and
A high C reactive protein level (particularly which does not respond to steroid therapy)
are markers of severe disease (which may fail medical therapy) but do not help define the anatomical extent of disease.
