skinner

what is the #1 cause of death for animals?

cancer

what does distal metastasis indicate?

systemic neoplasia

what is a common location for metastasis to occur from the primary site of a tumor?

the draining lymph node

what is the burden of neoplasia on a patient?

can impact how a patient feels based on the substances produced by the mass

if a mass rapidly changes from small → large, what are we more concerned about?

that this mass is a malignant form

what is key information from the PE that can help narrow down the dx of a mass?

• tissues involved

• movable or adhered

• painful to touch?

• pt BCS

• location

are skin or SQ masses “actually” encapsulated?

no, a pseudocapsule tends to form, therefore they are not actually limited to a local area

why is it so important to ID what type of tumor it is?

so we can understand prognosis and extent that the tumor is present to make a plan of action

what is the reactive zone of a mass?

the zone around the tumor where the immune system is interacting with it

is this mobile or fixed?

mobile

is this mobile or fixed?

fixed

what is the major concern when a tumor is presenting as fixed?

we don’t know how far the tumor goes inward in the body and how many structures it is actually interacting with

what are the techniques we use to dx a mass?

• aspirate → poke with a stick

• body map

• ultrasound guidance → for deeper aspirations

• biopsy → will given definitive dx

what are the two biopsy techniques?

• incisional

• excisional

what is incisional biopsy?

• taking out a chunk of the mass to send out

• get more reliable info without disturbing the margins of the tumor

what is excisional biopsy?

• removing the entirety of the mass and sending it

• this can be therapeutic → however commits to an approach of dealing with the mass before knowing exactly what it is

• this method messes with the margins of the mass → letching potential cancer cells into neighboring tissues

if you suspect feline injection site sarcoma, how should you biopsy it?

you should ONLY ever use incision because it is super aggressive and excisional can make it far worse condition

what are the pros and cons of biopsy?

pros

• allows more definitive dx

• better planning

cons

• two procedures will need to be done = 1 for biopsy + 1 for removal once dx comes back

• may increase risk of recurrence → seeding the biopsy track with cancer cells

what are the two types of incisional biopsy methods?

• punch biopsy → great for skin/SQ masses

• wedge biopsy →

pick the best area to biopsy from?

B

when would excisional biopsy be preferred to incisional?

• no benefit of pre-op biopsy

• potential for hemorrhage

• easy curative resection

• **potential for seeding**

what are examples of excisional over incisional?

• thyroid

• lung mass

• intestine

• splenic

what if we don’t get good margins with the first surgery?

must take HUGE margins to be safe if any spread occurred from aggravating the mass

what are the % of pre-op diagnosis of masses?

• cytology = 17%

• incisional biopsy = 4%

if we know what we are dealing with before committing to surgical removal, we can have better prognosis outcomes

what are the two forms of metastasis?

• vascular spread

• lymphatic spread

what is staging of neoplasia?

• define extent of the disease

• tumor-specific

• BEFORE major intervention

generally, more involved = greater stage

how can lymph nodes be helpful in staging/dx of a cancer?

• palpation not senstive

• aspirates are 66% sensitive

• CT is 12% sensitive

• sites of drainage are variable

• can use contrasts to see where draining may occur

in what 2 cancers can lymphadenectomy be beneficial?

• AGASACA

• MCT

what are the two forms of surgical intent with masses/tumors?

palliative or curative

what are the questions we should ask ourselves before surgical management of a mass/tumor?

• can this disease be cured or managed with surgery?

• can I manage this disease with surgery? = do I have the skills/equipment necessary

• what effects will resection have if full removal can’t be achieved?

• is (neo)adjuvant therapy helpful? → chemo

when planning surgery for onco, we need to?

make a plan for both resection and closure based on the margins we need to achieve

what are the enneking classificaiton of surgical margins?

• intralesional

• marginal

• wide

• radical

what are intralesional margins?

taking out bits of the tumor, not used much

more likely in neuro

what are marginal margins?

• just taking out the tumor whole

• not for infiltration

when is marginal margins considered?

• benign/low-grade lesions → low risk of reccurrence

• anatomically encapsulated masses

• adjuvant therapy

what are wide margins?

taking out disease and its possible extensions from the main tumor in the surrounding tissues

• often 2-3 cm lateral margin

• fascial plan deep

if you can’t go deep don’t go ____

wide

what are radical margins?

taking the entire body part that the tumor is involved with

• 5 cm lateral

• 2 fascial planes deep

what is considered a fascial plane?

• fascial sheet

• muscle

• bone

• body wall

when is a revision necessary?

when incomplete margins occur

what are surgical considerations that need to be addressed pre-op?

• clip WIDE

• plans for management of site

• check availability of skin for closure

during surgery, what are the considerations that need to be made?

• treat cancer like infection and DO NOT SPREAD IT

• change gloves and instruments when working on multiple sites

• take care with drains → close to main site

how do submit a sample of a mass?

• leave ink margins if relevant → help to prove that all was removed

• formalin = 10:1

• framing notes that give details of patient and condition

after onco sx, what do you do?

• follow up with client and patient

• further treatment may be necessary based on what submission report says

what is primary wound closure?

surgical closure of a wound that has edges apposed and will heal by 1st intention healing

what are the main goals of wound closure?

• closure

• no complications

• cosmesis

what are required to achieve the goals of wound closure?

planning and proper technique

primary wound closure

close a site right after it is damaged

delayed primary closure

delaying when to close a wound but closing before any granulation tissue forms

secondary closure

manage a wound open until it is clean and healthy with granulation tissue to then close

second intention healing

leaving a wound to close overtime on its own

what are Halsted’s 7 principles of surgery?

1) strict aseptic technique

2) gentle tissue handling

3) meticulous hemostasis

4) preservation of blood supply

5) obliteraction of dead space

6) accurate anatomic apposition

7) minimisation of tension

what area of tissue that supply blood to skin and SQ tissues?

deep or subdermal plexus

why to use primary closure?

• simple

• rapid wound healing

• reduce pain

• minimise scarring

• protect underlying tissues

• cosmesis?

• cost? → may be less than second intention healing with visits and bandage changes

what are the patient characteristics that you must consider when deciding on how to close a wound?

• systemic condition

  • immunosuppression → reduced wound healing, more prone to infection

  • metabolic disease → reduced wound healing = diabetes or cushings

  • cancer

  • radiation → causes delayed healing

• temperament

• species?

what are the wound factors that must be considered when deciding on how to close a wound?

• location → higher area or contamination or highly mobile area?

• configuration → is it even possible to close this?

• tension

• blood supply → a traumatic wound can have degloving that doesn’t declare itself for a number of days

what contamination levels are okay to close?

clean and clean-contaminated

what type of contamination is questionable to close?

contaminated wound → your judgement call/ on a case by case basis

how long does it roughly take for bacteria to grow enough in a wound to produce infeciton?

6 hours

what is the level of growth in bacteria that can occur in 6 hours?

10⁵ bacteria per g tissue

what other wound factors can cause you to question whether to close or not?

extent of tissue trauma

• tissue loss

• crushing/shearing/burn

• lag time

what is the general guidelines of skin tension lines?

• on trunk = tension runs parallel

• on limbs = perpendicular

in what oriention to the tension lines do you want to close a wound?

parallel to tension lines

how to help to promote apposition with deep lesions?

• multiple layer closures

• muscle movement can be used to decrease space superficially

what do we want to use to create good apposition of the SQ?

• distribute tension

• decrease dead space

• cruciate or mattress sutures

• can also take wider bites that and into the fascial plane

  • can then add an additional suture in the skin to fully close - intradermal

continuous horizontal intradermal pattern

• ~50% overlap of bites

• small bites

what happens with an intradermal pattern that has no overlap or larger bites?

gapping of the incision

simple interrupted

• poor tension relief

• slow to do

cruciate mattress

• some tension relief

• faster to put in

simple continuous

• fast

• not for high tension/motion

ford interlocking

• fast

• more secure if broken compared to simple continuous as it grabs onto itself

what are dog ears created by suturing a wound close?

folding up of skin after suturing an awkward wound

what are the reasons for dog ear formation?

• unequal suture spacing

• non-linear wound

are dog ears really a problem?

no more a cosmetic problem and will diminish with time

what is a technique you can use to close a very large wound?

halving to help guide your suturing placement

can halving work on a curved wound?

yes! suture bits need to be placed at different lengths across the curve so halving can help guide

how can you close a rectangular lesion?

close corners to bring middle closer together then

triangular closure

close up each side of triangle until meet in middle

what component of a primarily closed skin incision is most likely to fail with excess tension?

tissue

excessive tension of skin can lead to what?

dehiscence and tissue necrosis

what is another aspect that can cause dehiscence?

excessive activity that puts too much motion and tension on healing wound

what are the two methods of tension relief?

• redistribution

• creep

what are the two forms of creep?

• mechanical

• biological

what is mechanical creep?

• stretching/breaking collagen and elastin

• takes hours to days

• common to use with larger defects

what is biological creep?

• allowing new skin to grow

• takes weeks

what is undermining?

mobilizing skin by separating it from deeper levels but going deep to the cutaneous trunci

why do keeping the cutaneous trunci with the tissue in undermining important?

• preserves subdermal plexus

• preserve vessel

all this keeps the skin viable

walking sutures

• tension relieving

• move skin across a defect → offset deep and superficial bites

• stretching skin out

• close dead space

what are the types of external sutures that help to relieve tension?

• mattress sutures (horizontal, vertical, cruciate)

• far-far-near-near/far-near-near-far

bolster/stent sutures

• pre-place with wide bites

• padding to distribute tension

what are releasing incisions?

• incisions in healthy skin

• heal by second intention

• distal limbs is an optimal area to use this technique

mesh releasing incisions

~ 1 cm or less incisions parallel to the closure and staggered

what is another way to close a large defect?

skin stretching

what are the options of skin stretching?

• commerical/homemade

• velcro/suture

• adjusting the tension over time

what are flaps used for?

to fill large defects

what are the options for flaps?

• skin

• mucosa

• muscle

• composite

when creating a flap, what will you inevitably do?

cut off some blood supply to the flap, making the tip slightly ischemic

what occurs at the base of the flap to blood vessels?

those vessels in line with the flap will become engorged to supply the area

what are the dimensional limitations of creating a skin flap?

the length should not be 2x greater than the width

how can you make a flap longer than 2x the width?

by making a delayed flap that is where you cut the lengths (2 parallel incisions) you want but wait to cut the width part