Case 12 SBA Flashcards
Name the layers of the anterior abdominal wall
Skin
Camper’s fascia
Scarpa’s fascia
External oblique
Internal oblique
Transversus abdominus
Transversalis fascia
Extraperitoneal fat
Parietal peritoneum
Origin of external oblique muscles
Muscular slips from outer surfaces of lower eight ribs
Insertions of external oblique muscles
Lateral lip of iliac crest
Aponeurosis ending in midline raphe
Direction of external oblique muscles
Down and out, hands in pockets
Origin of internal oblique muscles (TIL)
Thoracolumbar fascia
Iliac crest between origins of external and transversus
Lateral two-thirds on inguinal ligament
Insertion of internal oblique muscles
Inferior border of lower three or four ribs
Aponeurosis ending in lines alba
Pubic crest and pectineal line
Direction of internal oblique muscles
Diagonally up and in, hands on heart
Transversus abdominus origin
Thoracolumbar fascia
Medial lip of iliac crest
Lateral one-third of inguinal ligament
Costal cartilages of lower six ribs
Insertion of transversus abdominus
Aponeurosis ending in linea alba
Pubic crest and pectineal line
Direction transversus abdominus
Horizontal
Rectus sheath
Covering which encloses the rectus abdominus muscle and the pyramidalis muscle
What forms the rectus sheath?
Aponeuroses external oblique, internal oblique, and transversus abdominus
Linea alba
Midline where rectus sheath fuses
Linea semilunaris
Lateral edge of rectus sheath on each side
Anterior portion of superior rectus sheath
Aponeuroses of external oblique and half of internal oblique
Posterior portion of superior rectus sheath
Aponeuroses of half of internal oblique and transversus abdominus
Anterior portion inferior rectus sheath
Aponeuroses of external oblique, internal oblique, transversus abdominus
Posterior portion inferior rectus sheath
None as in direct contact with transversalis fasci
Tendinous intersection
Fibrous bands separating rectus abdominus muscle
Arcuate line
5-6cm below umbilicus
Posterior wall of rectus sheath finishes
What is a hernia?
Protrusion of an organ or tissue through its covering into an abnormal position outside its normal compartment
What causes hernias?
Weak muscle/surrounding tissue
Increased intra-abdominal pressure
Reducible hernia
Can be pushed back into place
Incarcerated hernia
Unable to be pushed back to original place
Obstructed hernia
Contents compacted
Lumen not patent
Strangulated hernia
Squeezing causes ischaemia due to lack of blood flow
Where does a spigelian hernia occcur?
Linea semilunaris, around the level of the arcuate line
Describe presentation and risk of spigelian hernia
Small tender mass at lower lateral edge of the rectus abdominus
High risk of strangulation
Location of epigastric hernia
Midline between xiphoid process and umbilicus
What causes epigastric hernia?
Defect in linea alba
What is omphalocele?
Defect in abdominal wall
Infantile omphalocele
Prematurity
Adult omphalocele
Pregnancy, obesity, ascites
Paraumbilical hernia
Central swelling above or below umbilicus
Associations with paraumbilical hernias
Adults
Women
Obesity
Weak abdominal muscles
What can the sac contain in paraumbilical hernias?
Bowel and omentum
Where is the inguinal ligament?
From ASIS to pubic tubercle
What forms the inguinal ligament?
Formed from the aponeurosis of the external oblique muscle
Clinical significance of midpoint of the inguinal ligament
Landmark to find the femoral nerve
Mid-inguinal point location
Half-way between the pubic symphysis and anterior superior iliac spine (ASIS)
Significance of the mid-inguinal point
Femoral pulse palpation
Anterior boundary inguinal canal
Aponeuroses of external and internal oblique
Roof inguinal canal
Aponeurotic arching of transversus abdominus and internal oblique
Posterior wall inguinal canal
Transversalis fascia
Floor inguinal canal
Inguinal and lacunar ligaments
What does the inguinal canal contain?
Spermatic cord/round ligament of uterus
Genital branch of genitofemoral nerve
Ilio-inguinal nerve
Which is the more common inguinal hernia type?
Indirect
Indirect inguinal hernia
Peritoneal sac and potentially bowel enter the inguinal canal via the deep inguinal ring
What dictates the degree of herniation of an indirect inguinal hernia?
Amount of processus vaginalis still present
Where does an indirect inguinal hernia occur?
Lateral to inferior epigastric vessels
What can indirect inguinal hernias cause?
Bowel obstruction and strangulation
Direct inguinal hernia
Peritoneal sac bulges into the inguinal canal via the posterior wall and can enter the superficial inguinal ring
Where does a direct inguinal hernia occur?
Medial to inferior epigastric vessels
What causes direct inguinal hernias?
Weakened musculature
Femoral hernia
Abdominal viscera or omentum pass through femoral ring into femoral canal. Rare.
Where does a femoral hernia occur?
Inferolateral to the pubic tubercle
Routes of IBD treatment
Oral, rectal, systemic
What do aminosalicates contain?
5-ASA and sulfasalazine/mesalazine
Action of aminosalicates in IBD
Limit inflammation to mucosa
Why are aminosalicates less useful in Crohn’s?
Just limit mucosal inflammation
Aminosalicate dosing in IBD
2.4g per day
Continue as maintenance
What effects do aminosaliates have on developing cancer?
Chemopreventative so reduce risk
Aminosalicates in proctitis?
1g suppository at night
Which corticosteroid is used in IBD?
Prednisolone
Corticosteroid dosing in IBD
40mg initially weaning over 6-8 weeks
Corticosteroid use in UC?
Clipper/cortiment in moderate/severe
Corticosteroid use in Crohn’s
Budesonide in colonic Crohn’s
What is taken as an accompaniment with corticosteroids in IBD?
Calcium and vitamin D twice daily
Administration corticosteroids in IBD
Oral
Are corticosteroids good for long-term use in IBD
No
Actions of thiopurine and methotrexate
Modify immune activity or reduce cell number to decrease inflammatory response
Which IBD is methotrexate used for?
Crohn’s
Monotherapy thiopurine/methotrexate use in IBD?
Induction and maintenance of remission
Why are thiopurines and methotrexate used with anti-TNF drugs?
Protect from immunogenicity
Combination of what with thiopurine leads to higher remission rates in IBD?
Infliximab
Biologic drugs action
Bind to target and make it harmless
Infliximab
Anti-TNF monoclonal antibody, chimeric
Vedolizumab action
Gut-selective anti alpha-4 beta-7 integrin therapy
Pros of using Vedolizumab in IBD
Favourable safety profile
Low immunogenicity
Cons of using Vedolizumab in IBD
Expensive compared to biosimilar drugs
Biologics used in IBD
Infliximab, Vedolizumab, Ustekinumab
What is ustekinumab used for?
Crohn’s
UC
psoriasis
Psoriatic arthritis
Pros of ustekinumab in IBD
Favourable safety profile
Low immunogenicity
Cons of ustekinumab in IBD
Lack of safety data in pregnancy
Expensive compared to biosimilar drugs
JAK inhibitors in UC
Tofactinib and filgotinib
How to JAK inhibitors act?
With variable affinities for JAK1, JAK2, and JAK3 pathways
Non-selective JAK inhibitor
Tofactinib
Risks associated with tofactinib
Shingles
Venous thromboembolism (VTE)
What are the risk factors for shingles and VTE in tofactinib use?
Major surgery
Immobilisation
MI in previous three months
Heart failure
HRT
Combined pill
Coagulation disorder
Malignancy
Non-pharmacological treatments of IBD
Research studies, clinics, nurse specialist appointments
Definition of diarrhoea
three or more loose stools per day with >500ml fluid and electrolytes lost
Causes of osmotic diarrhoea
laxatives, non-absorbable food, congenital/acquired disorders of digestion
what is osmotic diarrhoea?
malabsorption
what is secretory diarrhoea?
ion transport defect, imbalance between secretion and absorption
causes of secretory diarrhoea
enterotoxins, laxatives, hormone secreting tumours, medication, allergy
how does motility disturbance cause diarrhoea?
insufficient time for absorption