Surgery Flashcards
What are properties of the “ideal” suture (which doesnt exist)?
- maintain tensile strength
- absorbed predictably
- Bio-inert
- Sterilized
- monofilament
- economical
Absorbable suture loses tensile strength in _____ days due to phagocytosis by macrophages or enzymatic hydrolysis.
60
Non-absorbable suture retains tensile strength for greater than _______ days.
60
________ suture has the most unpredictable tensile strength loss
natural
__________ suture has better predictability of tensile strength loss, however the downside is that it has a lot of memory.
synthetic
Multifilament suture is created by twisting or braiding multiple strands together to make a single strand. It is coated which improves its handling properties, however the biggest downside to multifilament suture is …
the filaments create a nidus for infection
A suture that is ________ absorbs fluid and transports bacteria. This is a common property of multifilament suture.
capillary
If you are suturing skin, what is the best suture property to have – capillary or non-capillary?
non-capillary – because this suture will not absorb water and transport bacteria. the skin has normal flora or even pathogenic flora if wounded. if you pass a capillary suture through the skin into inner tissues, you can transfer bacteria from the outside into clean tissues and create infection.
Name this suture:
Natural, multifilament, absorbable suture
absorbed by macrophages. Major downside to this suture is that is causes a severe foreign body reaction
Surgical Gut (catgut)
Surgical gut suture causes major foreign body reaction, so __________ was developed. This suture decreases tissue reaction, increases tensile strength and has increases resistance to being degraded.
chromic gut
Chromic gut has good handling, minimal capillary action, good knot security when its dry, and is relatively inexpensive. What are the downsides to this suture type?
its still reactive and its packaged in alcohol-based liquids that are irritating.
the knot security will be poor when its wet
it is NOT autoclavable
if the wound is infected, the suture will lose tensile strength
why does chromic gut suture lose tensile strength when it is used in infected wounds?
macrophages absorb this suture. In a state of infection, more macrophages will be present, therefore the suture is more vulnerable to absorption
___________ is a synthetic, multifilament, absorbable suture that is degraded by hydrolysis. Half of its tensile strength is lost within 14 days. This suture is coated which decreases wicking and tissue drag.
Vicryl (polyglactin-910)
Vicryl has tissue drag and is multifilament so it can serve as a nidus for urinary calculi.
Advantages of vicryl include…
minimal reactivity
good handling and knot security
stable in contaminated wounds
predictable absorption
soft and easy to bury
A patient presents to your clinic after being hit by a car what looks like 3-4 days ago. A large laceration on the hind limb appears to be infected but needs to be cleaned and sutured. What are the best suture types to use that will be minimally reactive, stable in contaminated wounds, and wont stick around for too long?
Vicryl or monocryl
vicryl is cheaper ($5), monocryl is ~$15 per pack.
However, monocryl has more suture within an individual pack, so if the laceration is large, then that may be a better option.
___________ is a synthetic, monofilament, absorbable suture. It has high initial tensile strength, but loses 40-50% by 7 days, and has no tensile strength by 21 days. It gets absorbed within 90-120 days by hydrolysis.
Monocryl (poliglecaprine 25)
Monocryl suture is monofilament, has good handling (considered the most pliable monofilament suture), good strength, and absorbs predictably. Since it is degraded by hydrolysis and has all of the advantages listed above, this suture is commonly used for what procedures?
Dentals
it is minimally reactive and is able to be used in contaminated wounds.
________ is a monofilament, synthetic, absorbable suture degraded by hydrolysis. It loses almost half of its tensile strength within 4 weeks, but then absorption completes within ~ 6 months.
PDS (polydioxanone)
PDS suture is commonly used in closure of ___________ because it is minimally reactive, has no capillarity or drag, has good handling and knot security, predictable absorption, and can be used in contaminated sites.
linea alba during a spay
Why would you not use monocryl in a spay linea closure?
monocryl loses half of tensile strength in 7 days. The linea alba takes at least 2 weeks to gain only 50% of its original strength back. You need to choose a suture that will uphold tensile strength past that 2 week mark at least, but longer is more ideal to cover for any potential delays in the healing process.
What are the 3 disadvantages of PDS?
its expensive, tends to kink, and can be more reactive if used intradermally.
You perform a spay and used PDS to do the closure. The dog presents 1 month post-op because there is a inflammed, elevated red bump that resembles a pimple on top of the incision site. How do you explain this to the owner and what do you do to treat it?
This is a PDS reaction. PDS suture caused a tissue reaction at the end of the suture where the knot was buried. This is not a serious complication. It can be popped and will heal!
_______ is a multifilament, natural, non-absorbable suture that has good initial tensile strength. It loses 50% by 1 year and 100% by 2 years. It is degraded by phagocytosis
silk
Silk suture is inexpensive and beneficial because of what property?
excellent handling
Silk does cause a moderate tissue reaction and has capillarity so it can lead to infection. This suture also can lose tensile strength if it gets wet. What is the knot security of this suture?
poor to fair
__________ is a monofilament, synthetic, non-absorbable suture that has LOTS of memory and poor knot security.
Nylon
Nylon has lots of memory, poor handling, poor knot security, low COF, and can be irritating d/t being prickly. This suture does not sound desirable at all… what are the advantages to it?
it is minimally reactive, biologically inert, non-capillary, inexpensive, and the byproducts from breakdown are antibacterial.
_______________ is a monofilament, synthetic, non-absorbable suture. It is minimally reactive, but has lots of memory. It is known for being the least thrombogenic suture.
polypropylene
Polypropylene is slippery and has lots of memory which makes handling difficult. However, it has 3 main advantages:
- its inert – minimal tissue reaction elicited
- excellent knot security
- can use in contaminated wounds
What suture type is non-absorbable, multifilament, and is considered non-sterile because it comes on reel?
braunamid
________ suture has good handling, is inexpensive, and has good tensile strength. However, its extremely tissue reactive and not sterile so it should never be buried!
braunamid
A _________ needle is where the suture is attached directly to the needle. This is much less traumatic than eyed needles.
swaged
_______ needles tend to be dull and cause tissue trauma because they are reused.
eyed needles
_________ needle is sharp, has a non-cutting point, and a cylindrical body. This type of needle is used for viscera, muscle, and subcutaneous tissues (all considered to be “softer” tissues).
taper
_________ needle has a triangular point with 3 cutting edges
cutting
__________ needle has a flat concave surface which minimizes cutting through tissue as you go through it. It is used for tougher tissues like the skin, subcutaneous, and intradermal layers.
reverse cutting.
A patient presents to you with a large mass on the flank. What type of incision will you choose that will successfully remove the mass but adhere to halsteds principles of closure.
elliptical incision
Your incision should be (parallel/perpendicular) to the lines of tension on the animal
parallel
To reduce tension during closure, you can use this closing technique FIRST:
closure by halves
When you are doing a scrotal ablation and you are attempting to close the incision, you find that the tension is not allowing for adequate closure without tension. What can you do to relieve this tension?
positional tension relief – have the assistant untie one or both of the patients legs to position them in the more “natural” position so you can suture the incision closed with the appropriate amount of tension.
___________ is the separation of the skin from the subcutaneous tissue. This allows you to free up the tissue, avoiding the subdermal plexus, and makes it more mobile for closure with minimal tension.
undermining
If undermining is not enough to relieve tension during closure, you can use tension relieving sutures to attempt to relieve additional tension. Describe how the tension relieving sutures reduce tension.
bonus if you can name what pattern is typically used for this
they make a broader area that the tension of closure will pull against, making it less likely for the sutures to break through the skin as a result of excess tension.
Mattress patterns are used.
T/F: you can add a stent underneath of tension-relieving sutures to relieve tension even further.
true
____________ is a rare technique used to decrease tension during closure. This technique requires making 2 cuts in order to pull the tissue forward over the incision and it will lay flatter with less tension exerted.
simple advancement flap
what is the blood supply to the cranial and caudal thoracic mammary glands?
lateral thoracic and intercostal arteries
What is the blood supply to the caudal thoracic and the cranial abdominal mammary glands?
cranial superficial epigastric artery (which is a branch of the internal thoracic artery)
What is the blood supply to the caudal abdominal and inguinal mammary glands?
caudal superficial epigastric artery (which is a branch of the external pudendal artery)
What is the main lymphatic drainage for cranial and caudal thoracic mammary glands?
What about the cranial and caudal abdominal mammary glands?
thoracic – axillary LN
abdominal – superficial inguinal LN
note: there is overlap between the mammary glands and their lymph drainage
What is the most common tumor of intact female dogs and has increasing incidence with age, but is preventable with OHE?
mammary tumors
T/F: most (50%) of canine mammary tumors are benign, the other 50% are malignant.
true
T/F: As long as you completely resect a canine mammary tumor, there is no difference in the outcome based on surgical procedure.
true
T/F: it is common for mammary tumors to recur after resection so monitoring is suggested.
true
T/F: mammary tumors in cats are common, but good news is most are benign
false - they are less common but majority are malignant (adenocarcinoma)
A 1 year old cat presents to you with enlarged mammary glands that have distal ulcerations. Your 2 differentials should include what?
- fibromatous hyperplasia
- mammary neoplasia
What are the key prognostic factors for mammary tumors in cats?
- tumor size – smaller = better
- extent of surgery – more aggressive = better
It is critical to do radiographs and/or abdominal ultrasound prior to deciding a treatment plan for a cat with suspected mammary neoplasia. Why?
radiographs (thoracic) and ultrasound will detect any metastasis. If there is cancer within the lungs or abdomen (medial iliac LN), then surgery is likely not an option because the cancer has gone too far and survival is very low.
T/F: you should FNA and do cytology on canine mammary neoplastic masses in order to differentiate malignant vs benign
FALSE – it will only tell you if its a mammary tumor vs inflammatory skin condition vs different type of tumor. It cannot differentiate between malignant or benign mammary tumors.
A 9 yo DSH cat presents to you with what you suspect to be a mammary tumor. What is your diagnostic and treatment protocol?
biopsy is rarely indicated because >90% are malignant
TOC is radical mastectomy with LN staging
Surgery is the TOC for ALL mammary tumors except ____________ or if there is the presence of distant metastasis because in these cases, it is too late.
inflammatory carcinoma
A ___________ is an excisional biopsy to remove the tissue around the mass. It is not recommended unless there is at least 1-2 cm or normal tissue removed with the mass and the mass itself is small and benign. It is not an option for cats.
lumpectomy
What is the best way to sample and stage a canine mammary tumor?
biopsy – incisional or excisional
A ___________ is the removal of either 1 or multiple mammary glands (1-3 or 3-5). This is a procedure for dogs with mammary tumors, not cats. The advantage to this procedure is the ability to also remove the lymph nodes and take multiple glands at once (en-bloc).
mastectomy
A ___________ is the removal of ALL mammary glands, SQ tissue, and associated lymphatics. This is indicated for cats, if there are mutliple tumors present, tumors that involve the central or third glands, or if the tumor is > 1 cm or malignancy is suspected.
radical chain masectomy
Why do we start with a unilateral radical chain masectomy and then go back and do the other side after healing?
because its much harder to close if you do bilateral at one time and there are less healing complications.
During mastectomy, you should tack down the subcutaneous fat to the rectus fascia to close dead space and …
reduce chance of seroma formation
Why would a vet choose to do OHE at the time of mastectomy in dogs but not cats?
in dogs, it has been shown to reduce the risk of new mammary tumors by 50%
in cats, it is not protective when it is performed at the time of tumor removal
What are the most common complications of mastectomies? (hint there are 9 and most are complications of any surgery)
- pain
- inflammation
- blood loss
- seroma formation
- infection
- ischemia
- dehiscence
- hind limb edema
- tumor recurrance
