1. The following are absorbable sutures a. Catgut b. Silk c. Polyamide (Nylon) d. Polyglyconate (Maxon) e. Polyglactin (Vicryl)
Suture materials The purpose of a suture
to hold a wound together in good apposition until such time as the natural healing process is sufficiently well established to make the support from the suture material unnecessary and redundant.
Choice of a suture
Choice of suture depends on: o
Properties of suture material
o
Absorption rate
o
Handling characteristics and knotting properties
o
Size of suture
o
Type of needle
Natural suture materials
Absorbable o
Catgut - Plain or chromic
Non-Absorbable o
Silk
o
Linen
o
Stainless Steel Wire
Synthetic suture materials
Absorbable
o
Polyglycolic Acid (Dexon)
o
Polyglactin (Vicryl)
o
Polydioxone (PDS)
o
Polyglyconate (Maxon)
Non-Absorbable o
Polyamide (Nylon)
o
Polyester (Dacron)
o
Polypropylene (Prolene)
Absorbable suture are broken down by either:
Proteolysis (e.g. Catgut)
Hydrolysis (e.g. Vicryl, Dexon)
Catgut
Made from the submucosa of sheep gastrointestinal tract
Broken down within about a week
Chromic acid delays hydrolysis
Even so it is destroyed before many wounds have healed
Strong and handles well but induces strong tissue reaction
Capillarity encourages infection causing suture sinuses and abscesses
Silk
Vicryl
Tensile strength o
65% @ 14 days
o
40% @ 21 days
o
10% @ 35 days
Absorption complete by 70 days
Polydioxone
Tensile strength
o
70% @ 14 days
o
50% @ 28 days
o
14% @ 56 days
Absorption complete by 180 days
Common errors of suture use
Too many throws. Increases foreign body size. Causes stitch abscesses
Intra-cuticular rather than subcuticular sutures ca using hypertrophic scars
Holding monofilament sutures with instruments reduces tensile strength by over 50%
Holding butt of needle causes needle and suture breakage
2. Peutz Jeghers Syndrome a. Is an autosomal recessive condition b. Often presents with anaemia in childhood c. Is characterised by circumoral mucocutaneous pigmented lesions d. Is associated with adenomatous polyps of the small intestine e. Malignant change occurs in 2-3% of polyps Benign colonic polyps
A polyp is a pedunculated lesion
Not all polyps are tumours
Not all polypoid tumours are benign
Not all benign tumours are polypoid
3. Regarding peptic ulceration a. H. pylori is a gram-positive bacillus b. Duodenal is more common than gastric ulceration c. Zollinger-Ellison syndrome is associated with gastrin hyposecretion d. H2-blockers will heal 85-95% of duodenal ulcers in 8 weeks e. Triple therapy can eradicate H. pylori in 80% of patients in one week
4. Head Injuries a. More than 1 million people are seen in UK hospitals each year with head injuries b. Skull X-rays can exclude an intracerebral haematoma c. Raised intracranial pressure is associated with an increase in cerebral perfusion d. Cushing's response consists of a rise in blood pressure and fall in heart rate
e. Pupillary dilatation usually occurs on the same side as the intracerebral haematoma
5. During surgery on the submandibular gland a. An incision on the lower border of the mandible is safe b. The submandibular gland is seen to wrap around the posterior border of m ylohyoid c. The facial artery and vein are divided as they course through the deep part of the gland d. The hypoglossal nerve is seen to loop under the submandibular duct e. Damage to the lingual nerve will cause loss of sensation to the posterior third of the tongue
6. Regarding pancreatic carcinoma a. 90% are ductal adenocarcinomas b. Less than 20% occur in the head of the gland c. The usual presentation is with pain, weight loss and obstructive jaundice d. Ultrasound has a sensitivity of 80-90% in the detection of the tumour e. Less than 20% of patients are suitable for curative surgery
7. Regarding the management of major trauma a. Deaths follow a trimodal distribution b. X-rays after the primary survey should be of AP Cervical spine, chest and pelvis c. Cardiac tamponade is characterised by raised BP, low JVP and muffled heart sounds d. Assessment of uncomplicated limb fractures should occur during the primary survey e. Deterioration of the casualty during the primary survey should lead to the secondary survey
8. Regarding appendicitis a. The risk of developing the illness is greatest in childhood b. Mortality increases with age and is greatest in the elderly c. 20% of appendices are extraperitoneal in a retrocaecal position d. Faecoliths are present in 75-80% of resected specimens e. Appendicitis is a possible diagnosis in the absence of abdominal tenderness
9. Regarding stones in t he gallbladder a. Cholesterol stones are the most common
b. Pigment stones are due increased excretion of polymerised conjugated bilirubin c. Are not a risk factor f or the development of gallbladder carcinoma d. 90% of gallstones are radio-opaque e. A mucocele of the gallbladder is caused by a stone impacted in Hartmann's pouch
10. Stones in the common bile duct a. Are found in 30% of patients undergoing cholecystectomy (Without pre-op ERCP) b. Can present with Charcot's Triad c. Are suggested by an bile duct diameter >8mm on ultrasound d. ERCP, sphincterotomy and balloon clearance is now the treatment of choice e. If removed by exploration of the common bile duct the T -tube can be removed after 3 days
Peptic ulcer disease
Number of admissions for uncomplicated disease is falling
Incidence of complications rated to NSAID use is increasing
Helicobacter pylori
H. pylori is gram-negative spiral flagellated bacterium
Produces urease
Important in the aetiology of peptic ulcers and gastric cancer
Found in: o
90% patients with duodenal ulceration
o
70% patients with gastric ulceration
o
60% patients with gastric cancer
Investigation
The organism can be detected by
Microscopy – silver or Giemsa staining of antral biopsies
Culture – difficult and requires special culture techniques
Rapid urease test – colour changes due to change in pH
13
14
C or C breath test – Ingested radioactive urea is broken down to carbon dioxide
Serology – detected immunologically using an ELISA
Sensitivity and specificity of H. pylori diagnostic tests Test
Sensitivity (%)
Specificity (%)
Rapid urease
90
90-95
Culture
80
100
Microscopy
90
90
Carbon breath test
95
95
Serology
98
100
Medical management of peptic ulcer disease H2 Antagonists
65% healing at one month
85% healing at two months
If stop treatment - 90% recurrence at 2 years
If maintenance therapy - 20% recurrence at 5 years
Proton Pump inhibitors
90 - 100% healing at 2 months
Low recurrence on long term maintenance
H. Pylori eradication
80% cured with dual or triple therapy
Two weeks amoxycillin, metronidazole and omeprazole
Short term recurrence rates low
Long term recurrence rates are at present unknown
Drugs have changed the need for ulcer surgery over last 20 years
Admissions for elective surgery have significantly reduced
The number of complications however remain unchanged
May be increasing due to increased NSAID use in elderly
Bleeding and perforation still have mortality of >10%
History of peptic ulcer surgery
Harberer (1882) - First gastric resection for benign ulcer
Billroth (1885) - Billroth II Gastrectomy
Von Fiselberg (1889) - 'Valve' to prevent bile reflux through gastroenterostomy
Mutation induces proliferation of mucosa throughout GI tract
Develop colonic polyps in teens or early 20’s
Untreated progresses to cancer by 30’s
Screening – by rigid or flexible sigmoidoscopy
Safe alternative to colonoscopy as rectal sparing rarely seen
Start late teens and continue until 40 yrs and polyp free.
Extra-colonic manifestations:
o
Osteomas. epidermoid cysts = Gardener’s Syndrome
o
Gastroduodenal polyps
o
Desmoid tumours
o
Congenital hypertrophy of retinal pigmented epithelium
Surgical options: o
Panproctocolectomy and ileostomy
o
Restorative panproctocolectomy
o
Subtotal colectomy and ileorectal anastomosis
o
NB will require surveillance of rectal stump
Hereditary non-polyposis colorectal cancer syndrome
Accounts for 5-10% of colorectal cancers
Results in mainly right sided cancers
Increased risk of other gastrointestinal, urological and gynaecological malignancy
Diagnosed by having 3 affected relatives, in 2 generations and one patient <50 years
Recommend to start colonoscopic screening starting 5 years before youngest affected relative.
Bibliography Campbell W J, Spence R A J, Parks T G. Familial adenomatous polyposis. Br J Surg 1994; 81: 1722 - 33.
Questions 11-20
11. Regarding crystalloid solutions a. Normal saline contains 154 mmol sodium and 154 mmol of chloride b. 3 litres of dextrose saline in a day will provide 90 mmol of sodium c. 2 grams of potassium chloride is equal to 57 mmol of the salt d. Hartmann's solution contains calcium and bicarbonate e. The daily maintenance potassium requirement of a 40 Kg woman is about 40 mmol
12. Regarding colloid solutions a. Human albumin has a molecular weight of 69 kDa b. Albumin has a half life in the circulation of about 15 hours c. Gelatins (e.g. Haemaccel®) are polysaccharides with a MW of about 35 kDa d. Dextrans reduce platelet aggregation and can induce anaphylaxis e. 6% Hydroxylethyl Starch (HES) is synthetic polysaccharide derived from amylopectin
13. Central parenteral nutrition a. Is a hypo-osmolar solution b. Typically contains 14-16g nitrogen as D-amino acids c. Typically contains about 250g glucose d. Is associated with metabolic disturbances in about 5% patients e. Can induce derangement of liver function tests
14. Solitary thyroid nodules a. Are more prevalent in women b. In the adult population less than 10% are malignant c. More than 50% of scintigraphically cold nodules are malignant d. The risk of a hot module being malignant is negligible e. Should be surgically removed in all patients
15. Regarding abdominal wall hernias a. Almost 100,000 hernia operations are performed annually in the United Kingdom b. 20% of inguinal hernias are indirect c. In women inguinal hernias are as common as femoral hernias d. The mortality assocaited with strangulation is over 10% e. The mortality has reduced dramatically over the past 30 years
16. The femoral canal a. Lies lateral to the femoral vein b. Has the inguinal ligament as its anterior border c. Has the lacunar ligament as its lateral border d. Has the pectineal ligament as its posterior border e. Contains the lymph node of Cloquet
17. Intermittent claudication
a. Affects less than 1% of men over the age of 50 years b. At 5 years 10% of claudicants will have progressed to an amputation c. At 5 years 20% of claudicants will have died from ischaemic heart disease d. Is usually associated with an ankle / brachial pressure index (ABPI) > 0.7 e. Is associated with a fall in the ABPI on exercise with delayed recovery
18. The pathology of ulcerative colitis a. Shows full thickness inflammation b. The rectum is almost always involved c. 10% patients have terminal ileal disease d. Enterocutaneous or intestinal fistulae are common e. The serosa is usually normal
19. Regarding surgery for ulcerative colitis a. 30% patients with total colitis will require surgery within 5 years b. Panproctocolectomy and pouch formation is appropriate as an emergency operation c. Pouches can be fashioned as 'S' 'J' or 'W' loops d. Over 90% patients with a pouch have perfect continence e. With a pouch the mean stool frequency is about 6 times per day
20. Regarding benign breast disease
a. Cyclical mastalgia is the commonest reason for referral to the breast clinic b. Fibroadenomas are derived from the breast lobule c. Lactational breast abscesses are usually due to Staph aureus d. Duct ectasia is more common in smokers e. Atypical lobular hyperplasia is associated with an increased risk of breast cancer
