ABDOMINAL WALL Flashcards
3 main complications of hernias including features:
Incarceration - irreducible
Obstruction - blockage symptoms
Strangulation - ischaemia, significant pain
Which type of groin hernia has the highest risk of strangulation?
Femoral
Anatomy of direct vs indirect inguinal hernia:
Direct = through posterior wall and superficial ring
Indirect = through deep and superficial ring
Walls of the inguinal canal:
Anterior = aponeurosis of external oblique
Floor = inguinal and lacunar ligaments
Posterior = Transversalis fascia (Hesselbach’s triangle)
Roof = transversalis fascia, int oblique and transversus abdominis
Differentials for a lump in the inguinal region:
Femoral hernia
Inguinal hernia
Saphena varix (dilation of saphenous vein at junction with femoral vein)
Content of inguinal canal inc male vs female:
Ilioinguinal nerve - most common to be damaged?
Genital branch of the genitofemoral nerve
Round ligament to labia majora
Spermatic cord into scrotum
Failure of closure of which structure predisposes to an indirect inguinal hernia?
Processus vaginalis
Common congenital hernia
Hesselbach’s triangle RIP mnemonic for the borders:
Rectus abdominis medial border
Inferior epigastric vessels sup and lat
Poupart’s ligament ()inguinal = inf
How to tell difference between direct and indirect inguinal hernia:
Reduce hernia
Pressure on deep inguinal ring @midpoint between pubic symphysis and asis, ask patient to cough.
If indirect, should stay in.
If out, then direct as the break in the tissue is more medial.
Boundaries of the femoral canal using FLIP mnemonic:
Femoral vein lateral
Lacunar ligament med
Inguinal ligament ant
Pectineal posterior
Position of femoral vs inguinal hernia:
Femoral = inferolateral to pubic tubercle
Inguinal = superomedial to pubic tubercle
A femoral hernia is typically non -reducible due to the small size of the femoral ring. What other feature of a femoral hernia can be commented on that is caused by the small size of the femoral ring?
Non-reducible
High risk of strangulation
Cough reflex is often absent!
Epidemiology of inguinal vs femoral hernias broadly:
Inguinal = 95% of abdominal hernias, men more risk
Femoral = more female, 5%
Important differentials to exclude in a femoral hernia:
Lymphadenopathy
Abscess
Femoral aneurysm
Hydrocele, varicocele,
Risk factor for incisional hernias:
Medical comorbidities that reduce wound healing
Symptoms of strangulated hernias:
Severe pain
May look dusky if necrosed / ischaemic which may resent with bloody stools
?Fever
Erythema
May be guarding, tenderness
Obstruction symptoms with distension, n&v,
What is a Richter hernia?
Only part of the wall is herniated (antimesenteric border) through the fascial defect, so can be strangulated with obstruction symptoms.
What is a Spigelian hernia, where does it occur and what Ix can be done?
At site of lateral rectus abdominis and linea semilunaris aponeurosis.
Lower abdomen, non-specific abdominal pain, often with no lump.
US can be done
Spigelian hernias have a high risk of strangulation
An epigastric hernia is a lump in the midline between the umbilicus and the xiphisternum. Give 3 risk factors:
Chronic cough e.g. chronic lung disease
Obesity
Extensive physical training
What should be used to prepare skin for surgery that gives the lowest incidence of SSI:
Alcoholic chlorhexadine
3 factors that increase the risk of SSI:
Razor use for skin
Tissue hypoxia
Delayed antibiotics in tourniquet surgery (should be done earlier than in normal surgery )
Primary vs secondary intention wound healing:
Primary = dermal edges are together e.g. scalpel. Heals faster than secondary.
Stages = haemostasis, inflammation, proliferation, remodelling
Secondary heals from the bottom up, requires more granulation tissue etc, takes a lot longer
Local factors affecting wound healing:
Type of wound
Size of wound
Local blood supply
Infection
Foreign material ?mesh
Contamination
Radiation
Systemic factors affecting wound healing:
Age
Comorbidities e.g. DM and CV,
Nutrition def esp vit C
Obesity
Classification of wound contamination, ranging from clean - dirty:
Clean = elective
Clean-contaminated = urgent but otherwise clean, minimal spillage
Contaminated = gross spillage, chronic open wound, penetrating wound <4hrs
Dirty = penetrating wound >4 hours, abscess, purulent perf
SSIs can be classifiied depending on the tissues involved:
Superficial = skin and subcut
Deep = fascia and muscle
Cavity = abdo / joint
Patient risk factors for SSI:
Increased age
Glucose control reduced,
Obesity
Smoking
Immunosuppression
Renal failure
Operation risk factors (2) and 3 protective operation factors for SSI:
Pre-op shaving
Increased length
Proph abx
skin preparation
When do symptoms of a SSI typically appear?
5-7 days
If prosthetic, 3 weeks
Management of SSI:
Remove stuures / stitches,
empirical abx
?drain
Which type of surgery is wound dehiscence most common in?
Abdominal
Superficial vs full thickness dehiscence:
Superficial = skin wound alone, ?infection ?dm ?nutrition causing poor wound healing
Full thickness = rectus sheath involvement, ‘burst abdomen’, secondary to raised intrabdominal pressure e.g. post op ileus, or if criticall yunwell
The most common cause of wound dehiscence is SSI, but there are other patient, intra-operative and post-operative factors that can increase the risk as well. Discuss these.
Intra-op = increased length, emergency, ifection, poor surgical technique
Post-op = prolonged ventilation, post of tranfusion, poor tissue perfusion e.g. hypotension
Sign of full-thickness dehiscence , and what should you do immediately?
Bulge of wound, leakage of pink serous or bloody fluid.
Remove clips, sutures, physically examine rectus sheath with swab to see if still intact
After even superficial dehiscence, the wound will heal by secondary intention and there for can take several weeks, maybe even requiring negative pressure dressings. What is the management of full dehiscence?
A-E
Analgesia
Broad spec abx
Cover wound with saline soaked gauze
Urgent return to theatre
Pathophysiology of keloid scarring:
Prolonged inflammatory phase of wound healing (immune cell infiltration into scar tissue)
Excess fibroblast activityand increased ECM deposition, tissue projects beyond original margins
Risk factors for keloid formation:
Black ethnicity african caribbean, and Asian
20-30y
Burns highest risk injury
Shoulders, ear lobes, sternal notch
Previous keloid
Main differential for a keloid scar:
Hypertrophic scar
How does the presence of a spout on a stoma , and site help you to differentiate what kind of stoma it is?
Spout = small bowel as more acidic and fluid, and would cause skin irritation
RIF = ileostomy
LIF = colostomy
LUQ = jejunostomy
Complications of stomas:
Prolapse,
Retraction
Infarction
Parastomal hernia
Psychosocial
Local skin irritation
Obstruction
Bleeding
Which type of stoma is most commonly used to defunction the colon e.g. following rectal cancer surgery?
Loop ileostomy e.g. RIF
When is a gastrostomy used? Which other site can be used for one of the purposes?
for feeding and decompression
Jejunostomy can also be used for feeding purposes
When are loop colostomies / ileostomies generally reversed?
6-8 weeks after initial surgery
What operation would result in a permanent end colostomy?
Abdomino-perineal resection - entire rectum and anus removed
When are end-ileostomies permanent? What is an alternative option?
Panproctocolectomy = total colectomy with rectum and anus.
Indications for this would include severe IBD and FAP.
Alternative ?ileo-anal anastomotic pouch
