Surgery 2 Flashcards
Where should sutures be placed when closing intestinal surgery sites and why?
- Submucosal layer
- Will not tear
- Over time, other layers will close and restore near to normal bowel function
What suture patterns can be used for the closure of GIT or bladder surgery?
- Continuous
- Interrupted
What suture material should be used in the luminal side of the GIT and why?
- Monofilament
- Reduce drag on tissue
- Absorbable
- e.g. PDS (polydiaxonone)
How many layers should be included in the closure of GIT or bladder surgery?
- Can be single or 2 layer closure
- Layers tend to divide selves into mucosal +submucosal layer and muscular+serosal layer
Describe the closure of the small intestine following biopsy (suture pattern, thickness, suture material, additional steps)
- Continuous inverting pattern e.g. Cushing pattern
- Bring serosal layers together on both sides to form air and water tight seal
- Commonly full thickness suture
- Absorbable monofilament
- Omentalise the site by draping omentum over the top
What is the purpose of omentalising a surgery site?
- Keeps contamination in local area
- Supplies blood
- Supplies lymphatic drainage
- Seals off site and aids healing
Describe enterectomy closure (technique, suture pattern, additional steps)
- End to end anastomoses
- Multiple interrupted sutures or continuous pattern
- Drape omentalise (may or may not need to secure omentum)
Why are synthetic monofilament suture materials commonly used in GIT surgery?
- Synthetics have less risk of reaction
- Monofilaments reduce bacteria wicking
Name the suture materials commonly used in GIT closure and the sizes used
- Polydioxanone (PDS)
- Polyglyconate (Maxon)
- Glycomer 631 (Biosyn)
- Polyglecaprone 25 (monocryl)
- 3/0 or 4/0
What needles are used for GIT surgery?
- Atruamatic round bodied needle
- Or tapercut point needle
- Ideally swaged on material as eyes are traumatic
How can you check for leaks in the bowel following closure?
- Syringe with saline on 23G needle
- Insert into lumen, use finger to prevent saline moving past site
- Observe for leaks
- However leaks are common and will contaminate the surgical site, so forcing leakage is not recommended
What is serosal patching?
- Used instead of omental draping where no omentum is available
- Use neighbouring intestine to act as patch
Describe cystotomy closure (thickness, suture pattern, suture material, additional steps)
- Full thickness, generally single layer, simple continuous or interrupted can be used
- Classically use 2 layer closure in very inflamed bladder
- Absorbable sutures
- PDS, monocryl, vicryl, 3-0 to 5-0, swaged on taper-point needle
- Omentalise
What suture pattern may be used if concerned about leakage in a thin walled bladder?
Single layer continuous appositional closure +/- second layer of inverting suture
What are some key considerations when closing a cystotomy?
- Non-absorbable material leads to nidus formation (foreign point where crystals aggregate)
- Is weak tissue *but regains ~100% strength within 14-21 days)
- More rapid loss of suture strength in contact with urine, especially infected urine (PDS best)
Outline the key steps to take before abdominal closure
- Check integrity of repair
- Check for bleeding
- Lavage and suction if required
- Count swabs
- Change gloves and instruments (contaminated by bowel and would cause skin infection)
- Plan reconstructino of the original anatomy
What layer is critical in abdominal closure?
- External rectus sheath
- Easier to locate cranial to the umbilicus vs caudally
Describe the closure of the linea alba (suture pattern, tension, suture material, additional)
- Continuous suture patterns preferable
- 6 throws at each end
- Absorbable monofilament e.g. PDS, 3-3.5 metric max (dogs)
- Long acting as takes time to regain strength
Why are continuous suture patterns preferable in the closure of the linea alba?
- Even distribution of tension along the length of the closure
- More rapid closure
- Less suture material = less foreign body material and so less change of reaction
Describe the closure of the abdominal wall subcutaneous layer (suture pattern, material, additional considerations)
- Simple continuous
- PDS or monocryl
- Need to eliminate dead space, use tacking sutures if necessary
Outline the closure of the abdominal wall intradermal layer (suture pattern and material)
- Simple continuous
- PDS or monocryl
Outline the closure of the abdominal skin (pattern, material, additional considerations)
- Interrupted or continuous pattern
- Non-absorbable
- Usually nylon
- Do not pull sutures too tight as need to allow for some swelling
What are the layers that must be closed in abdominal wall closure?
- External rectus sheath
- Linea alba
- Subcutaneous layer
- Intradermal layer
- Skin
What is ileus?
Lack of movement in the bowel
How can ileus be prevented?
- Feed after surgery
- Starving leads to villous atrophy, ulcerations, breakdown in gut barrier
- Oral route best but other routes may be needed
- Early enteral nutrition is indicated in most circumstances
Describe post-operative care for intestinal/urinary/abdominal surgery
- Early enteral nutrition
- Cover wound before leaving theatre
- Analgesia
- Antibiotics when required (contaminated surgery)
- Check wound every 24 hours
- Verbal and written discharge instructions for the owner
What are the clinical signs of wound infection/peritonitis/uroabdomen?
- Vomiting
- Pyrexia
- Dull
- Lethargic
- Inappetant
- Pendulus abdomen
- Palor
- In shock
How can you differentiate between wound infection, peritonitis and uroabdomen?
Paracentesis to look at fluids and identify process and therefore treatment required
What management may be required following post-operative complications in intestinal, urinary or abdominal surgery?
- May require revision surgery
- Copious lavage and drainage
- Peritoneal drainage
- Proactive especially if suspect peritonitis
What is the purpose of patient prep before surgery?
Reduce contamination of surgical wounds
Outline patient prep
- Clipping, scrubbing, draping
- Prep should be carried out in separate room as clipping and scrubbing generate environmental contamination
- Final prep in theatre and should not be clipped once there
Describe the key points regarding scrubs
- Are clean but not sterile, reduce shedding of skin debris
- Shirt tucked into trousers
- Do not wear outside theatre (cover)
- Do not wear for examining cases, visiting wards, changing bandages etc
Describe the key points regarding surgery sews
- Prevent gross floor contamination
- E.g. Clogs, sandals or overshoes
- Ensure shoes are clean
Describe the key points regarding surgical hats
- Reduce bacteria shedding from hair
- Should always be worn in theatre
- Ideally disposable
- Hoods better than hats
Describe the key points regarding surgical masks
- Protect wound from saliva and microorganisms
- More bacteria expelled when talking
- Are not 100% effective , nearer to 80% for up to 8 hours
- Do not tie by crossing over head
- Do not wear untied
What is the purpose of surgical hand scrubbing?
Kills transient bacteria and produces prolonged depressant effect on resident bacteria
Describe the traditional scrub protocol (SHS)
- Pre-wash hands to remove gross debris
- Rinse with scrub solution
- Pay attention to nails, thumbs and ulnar surfaces
- Ensure all surfaces of hands and forearms are exposed to scrub for at least 2 mins
- Always keep hands above elbows
Describe the surgical hand rub
- Sterilium
- Kills >99.9% of pathogens within 15 seconds
- Kills bacteria, yeasts, TB, mycobacteria, viruses (including HIV)
- Non-irritating/moisturinsing
- Must wash hands and clean nails before, must not have organic debris on hands
- Apply to dry hands
- Rub fo 1.5 mins
Compare the SHR and SHS
- SHR = surgical hand rub (sterilium)
- SHS = surgical hand scrub (chlorhexidine or PI)
- SHR and SHS have similar efficacy
- SHR has more lasting effect
- SHR is cost and time saving
Describe the towel drying protocol following the hand scrub
- Open towel and keep at arms length
- Consider towel in quarters
- Dry hands in top quadrants then dry arms on lower quadrants
- Ensure do not go back to hands after arms
- Ensure wipe down arms and do not go back up
- Prevent towel touching front of scrubs
What are the 2 basic types of gowns and drapes?
- Reusable woven fabrics
- Disposable non-woven fabrics
Describe the reusable woven fabric gowns/drapes
- Ineffective when wet
- Tighter weave = more effective barrier
- 30-50% culture positive at the end of surgery
- Prone to bacterial penetration at seams and cuffs so require careful inspection at each laundering for organic material
- Lint production
Describe disposable non-woven drapes/gowns
- Polyesters, wood pulp, synthetic polymers etc
- Randomly orientated fibres prevent penetration of fluid and bacteria
- Lower numbers of positive cultures at end of surgery and lower particle counts vs woven fabrics
- More expensive
Describe the key points regarding surgical gloves
- Are not an absolute barrier
- Commonly get hole (more common in orthopaedic surgery)
- Change gloves as soon as notice rip
- Closed gloving better
Explain what is meant by the sterile field in surgery
- Surgical site, instrument trolley and surgeon
- On surgeon, is chest to level of the surgical field, sleeves from cuff to 5cm above elbow
- Nothing below height of table/instrument trolley is considered sterile
- Cannot lean over surgical field if are not sterile
What are potential sources of contamination in theatre?
- The patient
- The surgical team
- Equipment
- Operating room environment
- Talking
- Moving in and out
What are the ideal characteristics of an antiseptic agent?
- Rapid action
- persistent effect
- Residual action
- Active in organic matter
- Non-irritant/toxic
- Easy to use, cost effective and economical
- Bacteriocidal broad spectrum activity
What are the common antiseptic agents used in surgical prep. solutions?
- Povidone iodine
- Chlorhexidine gluconate
- ## Alcohol tinctures
What is the mechanism of action of povidone iodine?
Damages cell wall and inhibits protein synthesis
What is an iodophor?
Iodine complexed with a high molecular weight carrier to reduce staining and local tissue toxicity, is the active form that acts as the disinfectant agent in povidone iodine solutions
Explain the effect of dilution on bacteriocidal activity of povidone iodine
- Greater dilution leads to paradoxical increase in bacteriocidal activity
- Is due to increase in free iodine
Describe the activity of povidone iodine
- Rapid action
- Bacteriocidal, broad spectrum
- Active against fungi, most viruses, protozoa, yeasts, mycobacteria
- Poor against spores unless prolonged contact (15mins-2hours)
- Effective at reducing bacteria for 1 hour, some persistent activity for 4-6 hour, minimal residual activity
- Activity decrease in organic material
Describe the effects of povidone iodine solutions on the patient and staff
- High incidence of skin reactions (up to 50%)
- Acute contact dermatitis
- Sensitivity in people
- Systemic toxicity if used on open wounds, mucus membranes and peritoneal surfaces
What is the mechanisms of action of chlorhexidine gluconate?
Bisbiguanide compound that alters cell wall permeability and causes protein precipitation
Describe the activity of chlorhexidine gluconate
- Rapid action
- Bactericidal, broad spectrum (better for Gram +ve than -ve)
- Effective against some resistant bacteria incl, MRSA
- Good against most yeasts
- Variable against fungi and some viruses
- Minimal effect against spores
- No effect against Mycobacteria
- Active in organic matter
- Excellent persistent and residual activity (binds to stratum corneum so repeated applications have cumulative effect)
Describe the effects of chlorhexdine gluconate on the patient
- No staining issues as seen with povidone
- Skin reactions uncommon (sporadic with prolonged use e.g. photosensitivyt, contact dermatitis, hypersensitivity)
- Minimal skin absorption so ok for neonates
- Ototoxic, cannot be used in middle or inner ear (deafness)
- Neurotoxic: cannot be used on brain or meninges
- Concentrations >0.05% are toxic to cornea and conjunctiva
What is the role of alcohol tinctures in surgical prep?
- Part of 2 step procedure
- Increases effictiveness of chlorhexidine and iodophores (povidone)
Describe the activity of alcohol tinctures
- Broad spectrum bactericidal
- Good activity against bacteria and fungi, variable for viruses, poor against spores
- Rapid kill, max activity requires 2 mins contact
- Best is 60-70% concentration
- Efficacy decreased in presence of organic matter
Describe the effect of alcohol tinctures on the patient
- Relatively non-toxic except in newborns
- Avoid open wounds
- Skin drying and degree of hypothermia via evaporation
- Risk of explosion/fire with electrocautory
What surgical prep solutions have the highest and most rapid kill rates of bacteria?
Alcohol tinctures
Outline why chlorhexidine may be superior to povidone iodine
- Broader spectrum of antimicrobial activity
- Longer persistent and residual activity
- Minimal loss of activity in organic matter
- Fewer skin reactions and toxicity
Describe the surgical preparation of eyes
- Povidone iodine
- Gently flush 1:10 dilution around eyelids
- 1:50 dilution on ocular surfaces and conjunctival sav
- Remove residual solution with sterile saline or Hartmann’s
Describe the surgical preparation of ears
- Pinna and surrounding skin can be prepared routinely
- Ear canal use 1: dilution of povidone iodine to flush, no alcohol
Describe the surgical preparation of open wounds
- All antiseptics cause tissue damage in open wound
- Use chlorhexidine at 0.05%
- Pack wound with sterile KY jelly while clipping to prevent contamination of wound with hair
- Clip routinely
- Lavage copiously with several litres sterile warm Hartmann’s or saline
- Pack with moist swabs into site while rest of area is prepared
Define asepsis
Absence of pathogenic microbes or infection in living tissue
Define disinfection
Destruction of pathogenic microbes e.g. use of germicidal substances on inanimate objects
Define sterilisation
Desctruction of all microorganisms on inanimate objects
Why is hair removal important in preparation of surgical sites?
Hair is a gross contaminant and significant reservoir for microbes and organic debris
Describe the surgical site preparation in theatre
- Patient positioned on operating table
- Final stage of prep should always be “no-touch” technique with alcholic tincture
- Allow alcohol solutions to dry completely
- Wipe up any pools of fluid
- If contaminated at any stage, start again
- Do not extend clip in theatre
Outline the different hair removal techniques for surgery prep
- Clippers: best, must be clean and in good condition, wide clip around proposed surgical incision (10-15cm)
- Depilatory creams: messy, expensive, irritant, not good on coarse hair, frequent skin reactions but may be good for rabbits
- Razors should never be used, cause significant grazing and associated with 10x increase in surgical wound infection rate
Describe the surgical preparation of legs and paws
- Climb entire limb for orthopaedic procedures (handing limb prep
- Consider if bones grafts required
- Paws have lots of bacteria and difficult to deal with nail beds and pads
- Ideally cover paw with impermeable material e.g. surgical glove
Describe surgical skin preparation
- Remove gross dirt, transient microbes, reduce resident microbial count to pathogenic levels with minimal tissue irritation, inhibit rapid growth of microbes
- Skin is not made sterile, does not penetrate deeper layers of skin
- “clean prep” using non-sterile supplies
- Wear gloves, good quality scrubs, no brushes
- Warm water, avoid wetting patient excessively
- Gentle pressure, circular motion, from centre outwards, discard until swabs come back clean
- Contact time important
What is the purpose of surgical draping?
Prevents bacteria from contaminating the surgical wound and surgeon’s gloves
Describe surgical draping
- Must remain securely fastened and provide impermeable barrier when dry and wet
- Quarter draping is standard
- Do not move drape once positioned
- Towel clamps break sterile barrier of drape so used towel clamps are contaminated
- Never use tissue forceps to attach drapes
What are the 3 parts of a needle?
- Point
- Body
- Eye
What needle radii are most commonly used?
3/8 or 1/2
Outline the use of straight needles
- Manually handled (curved manipulated with needle holders)
- Classically used for skin closure
What are the different needle section shapes called?
- Blunt (circular or elliptic)
- Sharp (polygonal)
- Compound (tapercut)
Compare standard and reverse cutting needles
- Standard: sharp point is on the top of the needle, on the wound side
- Reverse: sharp point is on the underside of the needle, away from the wound
Compare swaged and eyed needles
- Swaged easier to use and have optimal penetration properties
- But more expensive
- Eyed can be fiddly, can blunt over time and lead to increased tissue trauma
Describe the composition of needles
- Made from stainless allows
- Must be sufficiently rigid to resist forces applied but must also be flexible enough to bend before breaking
- Bending property is called “ductility”
Outline the use of taperpoint needles
- Produce less tissue damage as there is little lateral damage
- May blunt quickly
- Poor for cartilaginous skin
Outline the use of cutting needles
- Good for subcuticular use
- 3 cutting edges around shaft, wider than main body of needle so end up with a lot of collateral damage
- Poor for bowel surgery as may lead to leakage
Outline the use of tapercut point needles
- Edges are no wider than body of needle so minimise lateral damage
- But some cutting properties so can go through tough tissue
What are the factors must be met when choosing a needle?
- Must be long enough to pass through 2 wound edges in a single movement
- Diameter must be as small and as near to that of the suture material as possible
- Curved proportionally to the wound depth
- Use blunt needles wherever possible, cutting needles only for very resistant tissues
List the different properties that can vary between suture materials
- Natural or synthetic
- Mono or multi filament
- Absorbable or non-absorbable (within 60 days)
- Composition
- Diameter
- Length
- Colour
- Memory
- Plasticity
- Elasticity
- Fluid absorption and capilarity
What is plasticity?
Can be stretched but will not return to its original shape
What is elasticity?
Can be stretched and will return back to its original shape
What does the suture composition determine?
- Tensile strength
- Biologic behaviour
- Handling
List the natural suture materials
- Catgut
- Silk
- Surgical steel
What are the 2 categorisations of suture size?
- USP (United States Pharmacopia)
- Metric
Outline USP classification of suture diameter
- Based on tensile strength rather than diameter
- Goes from 11-0 to 7 increasing in tensile stength
Outline metric classification of suture diameter
- Based on diameter in mm
- 1/10mm of diameter suture i.e. 2=0.2mm
- Ranges from 0.1-10
List monofilament suture materials
- Glycomer 631 (biosyn)
- Polyglecaprone 25 (Monocryl)
- Polydioxanone (PDS II)
- Polyclyconate (MAxon)
List multifilament suture materials
0 Polyglycolic acid (dexon)
- Lactomer 9.1 (polysorb)
- Polyglactin 910 (Vicryl)
- Polygactin 910, irradiated (Vicryl Rapide)
Compare the effective time and absorption time of suture materials
- Absorbable means are absorbed within 60 days
- Absorption time can be significant e.g. for PDS is up to 210 days
- Effective time is more important than absorption time, as suture loses strength before it is fully absorbed
- PDS has the longest effective time of 28 days
What are the consequences of suture material implantation?
- Foreign body reaction (dependent on absorption characteristics)
- Is either phagocystosed (higher reaction, natural materials) or hydrolysed (less reaction, synthetic materials)
- Increased reactivity where more material placed
- Infection may occur (increased risk with multifilament material)
What are the advantages of monofilament materials?
- Smooth surface so less friction
- Does not support bacterial growth
- No capillary action
What are the disadvantages of monofilament materials?
- Some can have high memory
- Stiff ends can cause irritation if the knot is not buried
What are the advantages of multifilament materials?
- Easy to handle, less likely to have memory
- Soft and pliable
- Well tolerated by patients
What are the disadvantages of multifilament materials?
- Rough surface can cause tissue drag
- Potential spaces between filaments can act as a nidus for infection
- Capillary action/wicking
