6 - Lower GI Flashcards
What are the different classifications of inguinal hernias?
Hernias are a protrusion of part or all of an organ through the wall of the cavity that normally contains it
Direct Inguinal (20%) - Go through weakness in Hesselbach’s triangle. More common in older patients due to weaker abdominal wall or increased intrabdominal pressure
Indirect Inguinal (80%) - Bowel goes through inguinal canal through deep ring. Due to incomplete closure of processus vaginalis so congenital in origin
What are some risk factors for an inguinal hernia and what are the differential diagnoses?
Risk factors: male, increasing age, raised intraabdominal presure (chronic cough, heavy lifting, chronic constipation), obesity
Differentials: femoral hernia, saphena varix, inguinal lymphadenopathy, lipoma, internal iliac aneurysm, groin abscess, hydrocele
What are the clinical features of an inguinal hernia and how can you distinguish between a direct and indirect hernia?
- Lump in the groin that may reduce when lying down and gets worse on standing
- If incarcerated can be tender, swollen, irreducible and erythematous and can have signs of bowel obstruction. Pain out of proportion to clinical signs
- Reduce hernia and put pressure over deep inguinal ring (mid point of inguinal ligament). Ask to cough, if protrudes this is direct, if not this is indirect. Confirmed on surgery cannot be relied on
When a patient presents with a groin lump (suspected inguinal hernia), what are some things you should do on examination?
- Cough impulse
- Locaton (superomedial is inguinal, inferolateral is femoral)
- Reducible on lying down or with pressure
- Does it go into scrotum (can you get above it, is it separate from the tesyes)
How are inguinal hernias diagnosed?
- Usually clincial
- Only image if diagnostic uncertainty and give US in outpatient setting
- If incarcerated/strangulated use CT
How are inguinal hernias managed generally?
- If strangulated: urgent surgical exploration
- If symptomatic: offer surgical intervention due to risk of strangulation
- If asymptomatic: conservative but discuss risks of strangulation
How are symptomatic non-strangulated inguinal hernias surgically treated?
- Open Mesh Repair (Lichtenstein Technique): if unilateral
- Laparoscopic: for bilateral or recurrent inguinal hernias or can be used for primary hernia but high risk of chronic pain or females
Laparoscopic is a longer operating time but quicker post op recovery, fewer complications and less post-op pain
What type of patients are at high risk of chronic pain with an open inguinal mesh repair?
- Young and active
- Previous chronic pain
- Predominant symptom of pain
What are the complications of inguina hernias and post-operative complications for their repair?
Inguinal Hernia: incarceration, obstruction, strangulation
Post op: (see image)
What is the femoral canal made up of?
In the anteror thigh and contains lymph vessels, lymph nodes and loose connective tissue
Superior border is the femoral ring that is normal covered by a septum but some omentum or abdominal contents can get through and cause a hernia
What are some risk factors for a femoral hernia and why are they a high risk of strangulation?
- Risk Factors: female, pregnancy, raised intraabdominal pressure, increasing age
- More prone as narrow neck and rigid borders of femoral canal with concave lacunar ligament
- More common in women because of the wider anatomy of the pelvis
What are the clinical features of a femoral hernia?
- Small lump in the groin medial to femoral pulse
- Will present as emergency
- Vomiting
- Often irreducible due to tightness of femoral ring
Sometimes femoral hernia can roll above inguinal ligament and appear as inguinal hernia
What are some differential diagnoses for a femoral hernia?
- Inguinal hernia
- Femoral canal lipoma
- Lymph node
- Saphena varix (will disappear on lying and have palpable thrill)
- Athletic pubalgia
How are femoral hernias investigated?
- Clinical diagnosis
- Pre-op assessment as will need surgery
- Can do US or CT abdomen pelvis
How are femoral hernias managed?
- Surgery within 2 weeks of presentation due to risk of strangulation
- Operation involves reducing hernia and reducing size of femoral ring by suture pectineal and inguinal ligaments or putting in mesh plug
- High or Low approach (Inguinal ligament). Low less likely to damage inguinal structures but less space to remove any compromised bowel. High approach used in emergency
What are the complications with femoral hernias and complications with their surgical repaire?
- Strangulation
- Obstruction
- Bowel resection if strangulation
- Wound infection
- Cardiorespiratory complications
What is an epigastric hernia and what causes them?
- Occurs in the upper midline through the line albea
- Usually due to raised chronic intraabdominal pressure (obesity, pregnancy, ascites)
- Usually affect men and often asymptomatic
- Midline mass that disappears on lying back
How can you distinguish between divarication of the recti and an epigastric hernia?
Divarication is a cosmetic condition due to weakening and widening of the linea alba
Divarication is just stretched linea alba, no defect, so will not feel muscle tear
What is a paraumbilical hernia and how do they present?
Herniation through the linea alba around the umbilical region (not the actual umbilicus).
Due to chronic raised intraabdominal pressure and they have a lump around the umbilical region
Extremely common and often contain pre-peritoneal fat and sometimes bowel but rarely strangulate
What is a spigelian hernia?
- Hernia that occurs at the semilunar line around the level of the arcuate line (lateral border of the rectus where the aponeuroses fuse)
- Small tender mass at the lower lateral edge of the rectus abdominis
- High risk of strangulation so urgent surgical repair
What is an obturator hernia and how will they present?
- Hernia of the pelvic floor through the obturator foramen into the obturator canal
- Common in elderly women who have lost a lot of weight
- Mass in upper medial thigh and may have features of bowel obstrution
- May have positive Howship-Romberg sign due to compression of obturator nerve
What are Littre and Lumbar hernias?
Littre: herniation of a Meckels diverticulum, often into inguinal canal and often becomes strangulated
Lumbar: posterior hernia that occurs spontaneously or iatrogenically, posterior mass with back pain
What is a Richter’s hernia?
Any hernia site but the anti-mesenteric border becomes strangulated so only part of the lumen of the bowel is in the hernial sac
Tender irreducible mass and obstruction symptoms
Urgent surgical intervention
What are the contents of the inguinal canal in males?
What is the definition of the following terms:
- Diarrhoea
- Acute and Chronic diarrhoea
- Dysentry
- Traveller’s diarrhoea
Risk factors are poor food preparation, immunocompromised and poor personal hygeine
How can you tell what causative organism caused gastroenteritis?
Time between ingestion of food and symptoms
Bacterial toxins = hours
Virus = days
Bacteria = weeks
Parasites = months
What are the presenting features of gastroenteritis and what are some questions you should ask in the history of a patient presenting with this?
- Cramp-like abdominal pain and diarrhoea (with possible mucus and blood)
- May have vomiting, night sweats and weight loss
- May have pyrexia and dehydration
How is gastroenteritis investigated and managed?
Ix: none unless blood/mucus in stool, immunocompromised or persistent, then do a stool culture
Mx: rehydration, education to prevent in the future, exclusion from work for 48 hours from last episode of D+V, if food posioning report as notifiable disease
What are some important causes of dysentry you should consider when a patient presents with gastroenteritis?
- Campylobacter
- Shigella
- Salmonella
- Norovirus
What are some viral infective causes of gastroenteritis?
- Norovirus: most common viral gastroenteritis in adults, usually abdominal cramps, D+V and lasts 1-3 days
- Rotavirus: common in young children and resolves in about a week
- Adenovirus: common in kids
What are some bacterial infective causes of gastroenteritis?
- Campylobacter
- Shigella
- E.Coli
- Salmonella
ALL GRAM NEGATIVE
What are some bacteria that produce toxins that cause gastroenteritis?
Usually acute onset D+V lasting 24 hours
What are some parasitic causes of gastroenteritis?
More common in traveller’s diarrhoea
What is the most common cause of hospital-acquired gastroenteritis and how does this organism cause symptoms?
C.Difficile (Gram-positive) usually arising following use of broad spectrum abx that disrupts normal microbiota so C.Diff can overgrow
Produces exotoxin A and B that cause an immune response from the bowel so inflammatory exudate on colonic mucosa
Severe bloody diarrhoea and risk of toxic megacolon (dilated bowel with risk of perforation)
How is C.Diff investigated and managed?
Ix: stool culture and C.Diff Toxin (CDT) testing
Mx: IV fluid rehydration, oral metronidazole (or vancomycin in severe cases)
Have low threshhold for treatment with immunocompromised patients regardless of the cause of the gastroenteritis
What are some non-infective causes of gastroenteritis?
- Radiation colitis
- IBD (Crohn’s and UC)
- Microscopic colitis
- Chronic ischaemic colitis (usually affects watershed area around splenic flexure and is seen on endoscopy as blue swollen mucosa)
What is the pathophysiology of angiodysplasia?
Causes GI bleeds and it caused by formation of arteriovenous malformations between previously healthy blood vessels, usually in caecum and ascending colon
Most common cause of small bowel bleeds and second most common cause of rectal bleeding in over 60s
Can be acquired or congenital
What are the clinical features of angiodysplasia and what are some differential diagnoses?
- Painless rectal bleeding AND
- Anaemia
- If upper GI bleed melena and haematemesis
- If lower GI haematochezia
- Differentials: oesophageal varices, GI malignancies, diverticular disease, coagulopathies
How is suspected angiodysplasia investigated?
Lab tests: blood tests including FBC, U+E’s, LFTs, clotting, G+S or crossmatch
Imaging: endoscopy or colonoscopy to rule out malignancy. may need capsule endoscopy if in small bowel. can do mesenteric angiography to plan for intervention
How is angiodysplasia managed?
Conservative
- If haemodynamically stable
- Bed rest and IV fluids
- Potential tranexamic acid
Radiographically
- If persistent or severe
- Endoscopy that subjects bleeding vessel to argon and electrical current
- Mesenteric angiography for small bowel that cannot be reached on endoscopy. Embolisation of vessel after catheterisation
Surgically
- Bowel resection (high mortality so only do if necessary)
Patients with angiodysplasia are at risk of a major GI bleed, what are some risk factors associated with a poor outcome for a upper GI bleed?
- Advancing age
- Liver disease
- Patient present in hypovolemic shock
- Current inpatients
What are some complications of angiodysplasia treatment?
- Rebleeding post therapy
- Risk of small bowel perforation in endoscopy
- Risk of haematoma formation, arterial dissection, thrombosis and bowl ischaemia in mesenteric angiography
What are GEP-NETs and how are they classified?
Gastroenteropancreatic neuroendocrine tumours that originate from neuroendocrine cells in the tubular GI tract and pancreas and they have the potential to be malignant
Most located in small intestine, with the rest in the stomach and rectum
What are the risk factors for GEP-NETs?
- Genetic
- MEN1
- VHL disease
- Tuberous sclerosis complex (TSC)
How do GEP-NETs present?
- Non-specific symptoms like vague abdominal pain, N+V, andominal distension
- Unintentional weight loss
- Can be functioning or non functioning depending on hormonal hypersecretion
How are GEP-NETs investigated?
- Chromogranin A and 5-HIAA levels
- Routine bloods including FBC, LFTs, pancreatic peptides
- Genetic testing
- Endoscopy or CT enterocylsis depending on location
- If metastatic with unknown primary do whole body somatostatin receptor schintography SSRS
How are GEP-NETs managed?
Often palliative as metastatic on presentation
Poorly differentiated: surgical resection then chemo if localised or if metastatic just palliative chemo
Well differentiated: localised disease and any liver metastases should be resected
What is a carcinoid crisis?
What is the pathophysiology of appendicitis?
Usually affects people between aged 10-30
Usually due to luminal obstruction of appendix from a faecolith, lymphoid hyperplasia, impacted stool or rarely a tumour
When obstructed commensal bacteria in appendix multiply so acute inflammation. Reduced venous drainage and localised inflammation leads to increased pressure in the appendix and in turn ischaemia
If ischaemia untreated can lead to necrosis and then perforation
What are some risk factors for appendicitis and some differential diagnoses?
Risk factors: FHx, caucasian (but ethnic minorities more likely to perforate if get it), summer
Differentials: see image