Surgery Flashcards
4 diseases requiring castration as treatment
Testicular neoplasia
Orchitis
Testicular torsion
Cryptorchidism
6 complications of castration
Scrotal bruising and oedema
Swelling
Seroma
Haemorrhage
Haematoma
Infection
1 advantage and disadvantage of open castration
Better ligature security
More bleeding
Steps for open castration
- Prescrotal incision made and advance testes by applying pressure through drape
- Scrotal ligament (remnant of gubernaculum) removed by gripping tail of epididymis with fingers and thumb, grasping ligament with haemostats and shear force
- 3 ligatures made around vasculature using rochester carmalts
Closed castration process
Ensure no abdominal contents in vaginal canal
Palpate cremaster muscle and anchor stitch through it, continue around the cord (vascular plexus and vas deferens)
A transfixing ligature is used
5 reasons for scrotal ablation
Neoplasia (sometimes with urethrostomy) -> Remove the good testicle first, closed for neoplastic testicle
Trauma
Abscess
Ischaemia
Pendulous (appearance)
Process of scrotal ablation
- Elevate scrotum & testes from wall
- Elliptical incision around the scrotum, being mindful of leaving skin for closure
- Can be open or closed
What is cryptorchidism?
Failure of one or both testes to descend into the scrotum
Inherited defect
Spermatogenesis is absent
Treatment of cryptorchidism
Castration - inguinal approach, laparotomy
What causes testicular torsion?
Mobility of vesskes
Often abdominal when they torse
3 types of testicular neoplasia and prognosis
Seminoma
Interstitial cell
Sertoli cell
Often same numbers and may cause feminising signs
Good prognosis <10% metastases prior to detection
What can testicular trauma cause?
- Significant bleeding (castrate)
- Sperm granuloma
- Fibrosis
- Possible infertility
What is hypospadias?
Developmental abnormality
Failure of fusion of the genital folds
If severe perform a urethrostomy (persistant open stoma)
Common in Boston terriers
What is persistent penile frenulum and how is it treated?
Fibrous band from the central penis to the prepuce
Usually ruptures at puberty
If persistent – resect
What is a bifid penis? What is the treatment?
Congenital abnormality
The smaller organ often does not contain a urethra
Treatment = amputate and suture the defect formed in the
urethra, tunica albuginea and mucosa
What are some examples of penile trauma?
- Stick injuries
- Wire fences
- Mating injuries
- Kicks
- Bite wounds
- Strangulation
- Severe haemorrhage
- Fracture of os penis
- Urethral prolapse
Treatment of penile trauma
Suture fresh lacerations
Antibiotics – topical and systemic
Amputation if severe
Urethrostomy
8 steps of penile amputation**
- Catheterise urethra
- Apply tourniquet
- Incise penis as bilateral flaps
- Remove catheter and transect the urethra
- Ligate the major vessels
- Incise urethra and spatulate
- Suture to penile mucosa using 4/0 absorbable suture material
- May need to shorten urethra
What is phismosis?
inability to protrude the penis beyond the preputial opening (restricted by
exteriorisation)
Causes of phismosis
Persistent frenulum
Hypoplasia of preputial opening
Trauma with secondary scarring
Often distended prepuce and don’t urinate with a normal steady stream
Treatment of phismosis
- Resect fibrous tissue
- Widen preputial opening - Wedge resection from the dorsal prepuce then suture preputial mucosa to the skin
- Circumferential excision and suture
What is paraphimosis?
permanent protrusion of the flaccid penis
4 causes of paraphimosis
Small preputial opening
Matted preputial hair
Congenitally short prepuce
May have self-trauma to the penile tip
treatment of paraphimosis
Surgically enlarge preputial opening
Amputate distal end of penis (small fluffies)
Preputial advancement
Structure of the prostate gland - blood supply and nervous supply
- Bi-lobed gland
- Vasa deferentia enter dorso-caudally
- Blood supply – dorsolateral capsule
- Hypogastric nerve (sympathetic)
- Pelvic nerve (parasympathetic)
Benign prostatic hyperplasia signalment and clinical signs
Benign enlargement of
the prostate
* Intact male
* 60% incidence in
dogs > 5 years
Constipation, tenesmus, haematuria, urethral bleeding, may have prostatic cysts, ribbon like stool
BPH DDx
Squamous metaplasia
Prostatic cyst or paraprostatic cyst
Prostatitis or abscess
Neoplasia
Diagnosis of BPH
Rectal examination: nonpainful, smooth, symmetrical enlargement of the prostate
Radiographs, Ultrasound, CT
Histopathology
Treatment of BPH
Castration
Faecal softeners
Oestrogen therapy
Anti-androgens
Prostatitis/abscessation signalment and clinical signs
Intact males
Depression, pain, vomiting, polyuria, polydipsia, haematuria, incontinence, stragnurai, UTA, pyuria, tenesmus, irregular bowel movement
Prostatitis/abscessation diagnosis
Rectal palpation (enlarged, painful)
* Radiology
* Prostatic wash
* FNA
* Ultrasonography
Treatment of prostatitis/abscessation
Castration
Antibiotics 4-6wks
Drainage = evacuate cavities, breakdown septae within gland, get samples for bacteriology, histology
Types of drains = penrose, foley, mushroom
Subtotal or total prostatectomy
Omentalisation - omentum provides drainage, adhesions, induces neovascularisation, functions in presence of infection
Signalment of prostatic neoplasia - population and types of cancers
Rare - older dogs and cats, entire and neutered
Mostly adenocarcinoma
Can be poorly differentiated, SCCs, transitional cell carcinomas
Early metastases to lymph nodes, bladder, lungs, rectum , bone
Early diagnosis hard, prognosis 3 months
Clinical signs of prostatic neoplasia
Tenesmus
Dysuria
Stranguria
Urethral bleeding
Lumbar pain
Lameness
Emaciation
Treatment of prostatic neoplasia
Total prostatectomy
Inoperative radiotherapy
Permanent tube cystostomy
Castration
Oestrogen therapy
Parenchymal Prostatic cysts Signalment
May be associated with BPH
Common
Fluid filled, non-septic, within or communicate with the prostate
Paraprostatic cyst signalement
Unknown aetiology
Adjacent and attached to prostate
Entire males
Large breeds
Calcified walls, fluid colourless-brown
Pyrexia
Diagnosis and treatment of paraprostatic cysts
Ultrasound, FNA, Rectal
Castration, drainage, excision, marsupialisation (create a pouch to allow draining outside abdomen following surgery), omentalisation
4 reasons for elective desexing
Reduction of mammary neoplasia risk
Treatment of behavioural conditions
Treatment of other medical conditions
Council registration
7 diseases prevented by OH
Pyometra
Metritis, subinvolution of placental sites
Uterine torsion
Uterine prolapse
Uterine rupture
Uterine neoplasia
Persistent pseudopregnancy
Best time to desex a female
Standard 6 months or before first or second oestrus
Shelters 8-12 weeks
Considerations for spaying a female
Decreased stress and operative time
Assurance animal is desexed when rehomed
Anaesthetic risk
Decreased maturation of external genitalia
Increased incidence of oestrogen responsive urinary incontinence
Increased risk of bony neoplasia in giant breeds?
Reasons a spay should be avoided on in season dogs
How long after a litter should be left for mammary involution?
- Uterus is more friable and increased blood supply
- Oestrogen can have detrimental effect on haemostatic mechanisms
- Delay for 4 weeks after the onset of pro-oestrus
- Desexing an early pregnant bitch is easier than in season
After a litter, wait 3 weeks after weaning to allow mammary involution
Risk of mammary neoplasia if spayed before first oestrus or after first and second
Before first = 0.5%
After first = 8%
After second = 26%
No decrease if spayed after 4th cycle
Entire cats have 7x the risk of mammary tumours
What are the broad ligaments?
Double folds of peritoneum that suspend the uterus and ovary
- The mesovarium - suspends ovaries
- The mesosalpinx - suspends oviducts
- The mesometrium - majority of broad ligament
What is the suspensory ligament?
Cranial continuation of broad ligament from the ovary that comes together in a distinct band which inserts on the middle and ventral thirds of the last two ribs
What is the proper ligament?
Continuation of suspensory caudally
Attaches the ovary to the uterine body/horn - continuous caudally as the round ligament that goes within the broad ligament, through the inguinal canal and ends subcutaneously near the vulva
Where is the ovarian arteriovenous complex?
Medial to the broad ligament and caudal to the suspensory
Convuluted - especially closer to the ovary
What is the ovarian artery? What does it supply?
A branch of the aorta - supplies the ovary and cranial aspect of the uterus
What does the right ovarian vein drain into?
Caudal vena cava
What does the left ovarian vein drain into?
Left renal vein
What is the uterine artery a branch of? Where is it located?
The internal pudendal artery
Positioned at the lateral aspect of the uterine body bilaterally
Enters the mesometrium at the level of the cervix
Where do the lymphatics of the uterus drain to?
Hypogastric and lumbar lymph nodes
Innervation of the female repro tract
Hypogastric plexus - sympathetic and visceral
Pelvic nerves - parasympathetic and visceral
Which ovary is more difficult to exteriorise?
Right
Steps for spay to removing the ovaries
- Exteriorise right ovary
- Break suspensory
- Ligate pedicle - make window in mesovarium caudal to ovarian vessels and triple clamp with carmalt rochester proximal to ovary
- Tie into crush of most proximal (PDS 0-3/0 for dogs)
- Transect the ovarian pedicle and hold in forceps without tension before releasing
- broad ligament broken or cut avoiding uterine vessels
Steps for spay from exposing uterine body
- Expose uterine body
- Single clamp cranial to cervix
- Remove as much uterine tissue as possible to avoid stump pyometra
- Single encircling ligature or transfixing if enlarged uterus
- Uterine vessels can be ligated independent to uterus
- Check abdominal cavity for haemorrhage
- close linea alba
- Close skin or do intradermal
What is used for linea alba closure?
Independent or continuous monofilament absorbable (1-3/0)
Complications of spay
Haemorrhage
Wound healing - suture reactions, seroma, fistulous tracts
Stump pyometra -> progesterone from remnants cause inflammation or granuloma from non-absorbable material or poor asepctic technique
Ureteral ligation, ovarian remnant syndrome, incontinence (11-20% desexed females)
Weight gain
Laparoscopic advantages in spay
Minimally invasive - maximises post op comfort
Great visualisation of structures
Laparoscopic disadvantages in spay
Cost of equipment and processing
Learning curve
Indications for caesarean
> 70d gestation (should be 63+/-2
Primary or secondary uterine inertia
Maternal pelvic abnormalities
Foetus oversized
Small litter - large foetuses and primary inertia from lack of hormonal initiation from foetus
Foetal malpresentation
Foetal death - ultrasound to detect if unresponsive to oxytocin and supportive care
Preop considerations for caesarean
If emergency compromised pateint, consider circulatory status and sepsis
Crystalloid replacement
Desex or not - controversy as prolonges anaesthesia but saves a procedure
Risk of aspiration pneumonia as food rarely withheld - careful ET tube cuff inflation and removal and prokinetic metoclopramide to increase lower oesophageal tone
Make induction to delivery as fast as possible
Where is initial incision for caesarean?
Ventral midline
2-3cm cranial and 5-6cm caudal to umbilicus
Large enough for uterus to be out quickly
What needs to be done prior to removing the uterus in a caesar?
Take care not to damage abdominal contents and gravid uterus
Pack off uterus from abdominal cavity with laparotomy sponges
Take care not to tear uterine vessels or uterus
Where should the uterus be incised for caesarean?
Avascular area within the body that allows for the removal of foetuses from both horns
Sometimes will need multiple incisions
Process of removing puppies in caesarean
Milk each foetus to uterine incision
Break through foetal membranes and clamp the umbilicus 2-3cm from the base
Rub vigorously to stimulate breathing - avoid swinging in an arc (brain damage)
Give sublingual dopram 0.2-1mg and check all pups are removed
Process of closing the uterus after a caesar
Single or double layer uterine closure - simple continuous inner of submucosa and not into the lumen
Continuous inverting outer such as cushing
3/0 or 4/0 monofilament absorbable taper-point needle
Uterus thoroughly lavaged before returning to abdomen, change gloves and instruments to close abdomen
Complications of caesar
Haemorrhage - intrauterine (oxytocin or OH) or peritoneal (ligature failure)
Infection - long or contamination
Foetal or maternal death
What is a pyometra a disease of?
the dioestrus phase of ovarian cycle while the CL is actively secreting progesterone
Ovarian or exogenous progesterone is required for it to exist
Pathophysiology of pyometra
Progesterone increases secretions of the uterine glands, inhibits myometrial contraction and closes the cervix - this causes cystic endometrial hyperplasia and inhibits leukocyte response, facilitating bacterial colonisation
Signalment of pyometra
Older entire bitches >6yo
Within 8-12wks of previous season - 4wks in cats
Increased risk with exogenous progesterone being given (oestrogen increases sensitivity of uterus to progesterone)
Is infection the primary cause of pyometra? What bacteria is most common?
No - usually present secondarily
E.coli with strep, staph, enterococci, klebsiella, proteus and psuedomonas
Anaerobes like clostridium with secondary toxaemia have been reported
Clinical signs of pyometra
Normothermic
Anorexia/depression
Vomiting/diarrhoea
PU/PD (e.coli affecting tubular function)
Vaginal discharge maybe
Poorly contaminated urine <1.030
Clin path of pyometra
Leukocytosis
Left shift and toxic change
Anaemia masked by dehydration
Azotaemia
Low USG
Diagnostic imaging for pyometra
Abdominal palpation
Rads - soft tissue density, displacement of GI structures
U/S most sensitive - uterine size, thickness of wall and fluid presence in peritoneal cavity
Medical treatment for pyometra
PGF2a luteolysis and BS antibiotics
Lower progesterone to open cervix and allow drainage
Re-infection likely so breed on following cycle
Surgical treatment for pyometra
OVH
Don’t rupture uterus
Remove all infected tissue and stabilise pre-op and AB
Omentalise stump and lavage
What is vaginal oedema and when does it occur?
Formerly vaginal hyperplasia
During oestrus and proestrus
Vaginal mucosa swells allowing transverse fold (arising from floor of vagina cranial to urethral orifice) to rupture through vulva - large mass protruding out
Mass exposed - ulceration, trauma,
When does vaginal hyperplasia regress?
Luteal phase - but will keep recurring and interfere with breeding and can recur in partruition causing dystocia
Other treatments of vaginal hyperplasia than OVH
Excision of prolapse
Lubrication and protection
Pharmacologic induction of ovulation using GnRH and hCG
Megestrol acetate -> Synthetic progesterone inhibits oestrogen in target tissue but also prevents ovulation
Vaginal prolapse - what is it similar to, when does it occur and treatment
Differentiate from vaginal hyperplasia by circumferential prolapse of vagina, also differentiate from tumour with biopsy adn exam
OCcurs after forced separation of mating or in advanced stages of parturition due to excess straining
Recognise early - reduce prolapse, or amputate
When is episioplasty used?
Treating perivulvular dermatitis
Changes in anatomy of perivulvar region
Neoplasia of the vulva/vagina
70-80% benig - Most common - leiomyoma, fibroma, lipoma
Malignant -> leiomyosarcoma
Surgical excision
Exposure can be improved by episiotomy
What is the definition of aseptic technique?
A set of techniques and practices designed to prevent or minimise microbiological contamination of the surgical wound
Factors associated with infection
Bacterial numbers >10^5
Bacterial type
Host resistance
Presence of foreign bodies
Interaction between host and bacteria
Sepsis definition
Presence of pathogens or their toxic products in tissues of patient
Asepsis definition
The absence of pathogenic microbes in living tissue
Sterilisation definition
Destruction of all microbes and living organisms, including spores (inanimate objects only) by physical or chemical means
Antisepsis definition
Use of antimicrobial chemicals on living tissues
Surgical infection time period
30d-2 months
12 months for orthopaedic
Goal of aspetic technique
Prevent surgical infection and encourage wound healing
Sources of bacterial contamination
Surgical personnel
patient
Theatre
Instrumentas and biomaterials
Aseptic technique -> surgical site, faciliates and environment
Prevention fo surgical infections factors:
Selection and prep of patient:
History, physical exam, CBC and biochem,, urine SG, treat underlying disease or remote infection
Factors increasing surgical risk
BCS
Age - old or young
Brachycephalic
Type of surgery
Hypoalbuminaemia
Anaemia
Ideal antiseptic agent should be:
Non-irritant
Bactericidal
Broad spectrum
Long residual activity
Not inactivated in the face of organic material
Economical
MoA iodophors, action time
eg Povidone-iodine
Penetrates cell wall and displaces molecules with free iodine
Broad spectrum, bactericidal
4-6h action
Toxicity of iodophores
thyroid dysfunction, acute contact dermatitis
Activity decreased by organic material
Bisbiguanide moA, spectrum, immediate action and persistent action
eg Chlorhex
Increase cell wall permeability, precipitates cellular contents
Broad spectrum, bactericidal or static depending on conc.
Persistnet action >6h and residual 1-2d
Chlorhex toxicity
Ototoxic, corneal toxic, neurotoxic
Alcohols moA, spectrum, action
Cell lysis, protein denaturation, metabolic interruption
Broad spectrum
Bactericidal rapid
No residual action
Corneal and neurotoxic
Bacteria found on skin and hair
Staph, micrococcus, strep, clostridium and bacillus
Clipping protocol
good area each side of incision
Nicks and grazes are focus for bacterial contamination
Clipping day before increases risk of infection 3x
Water soluble gel like ky jelly placed in open wounds prior to clipping
Initial, second and tertiary scrub agents
Initial - antiseptic/detergent mix
Second - alcohol wipe
Tertiary - antiseptic agent
Prep of surgeons skin principles
Mechanical removal of dirt
Reduction in transient microbial count to as close to 0 as possible
Prolonged depressant effect on resident microflora of hands and arms
Purpose of scrub suit
Not impermeable to bacteria, reduces particulate shedding in theatre
Scrub cap - hair bacteria
Shoe covers - external bacteria and hair being tracked in to surgery then out to clinic
Mask - aerosol drops directed to the side
Advantages and disadvantages of disposable scrub suit
Water repellent
Always in good condition
Less laundry
Resterilised
But expensive, less conforming, large stock required
Advantages and disadvantages of resuable scrubs
Cheaper, less waste
But poor barrier properties, labour intensive, threads can detach and lint into wound, reduced quality with repeated washing
Patient draping - four quadrant method
Keep hands covered
Do side closest to surgeon, adjacent quadrant, opposite quadrant then final quadrant placed by opposite surgeion and secured with towel clamp
how many organisms fall int site in an hour?
75,000
Theatre parameters
should be out of high traffic area
only necessary people enter and attired correcrtly
Not used for examinations
Mild pos pressure laminar air flow
Clean operations first
Damp dust all surfaces and disinfect surfaces and equipment, once weekly scrub of floors and walls
Methods of sterilisation
Physical - heat, filtration, radiation
Chemical - ethylene oxide, alcohols
Indicators of sterilisation
Chemical indicators - colour at temperature but does not show time of exposure or if items are sterile
chemical indicators - tape (class 1) and bowie dick indicator strips (class 2)
Then biological indicators
Consequences of post surgical wound infection
Wound breakdown or delayed healing - sepsis from implants, haemorrage from lysis around infected ligatures, evisceration, hernia repair failure
Septicaemia
Pain
Increased hospitalisation
All wounds become contaminated
Antibiotic prophylaxis - when to give
Perioperative antibotics buttress immune defence
More efficacious given prior to surgery - IV 20-30mins before first cut and repeated at 60-90min intervals
Post op indicated when: comorbidites, excess time in surgery, trauma, risk like orthopaedics
Duration of antibiotic therapy depends on:
Wound classification and individual patient
When are host tissues most susceptible to bacterial lodgement?
within first 3 hours of contamination
Class 1 surgical wound classification
Clean -> uninfected operative wound which no inflammation encountered and respiratory, alimentary, genital or uninfected urinary tract is not entered
Primarily closed or if needed drained with closed drainage.
Incisional wounds which follow non-penetrating trauma can be included here
Class 2 wounds
Clean - contaminated
Resp, alimentary or urinary tracts entered under controlled conditions and without usual contamination
Operations with biliary tract, appendix, vagina, and oropharynx included provided no evidence of infection
Class 3 wounds
Contaminated
Open, fresh, accidental wounds
Operations with major breaks in sterile technique or gross spillage from GIT, and incisions where acute, non-purulent inflammation is encountered
Class IV
Dirty-infected
Old traumatic wounds with retained devitalised tissue and those with existing clinical infection or perforated viscera
Organisms causing post op infection present in operative field before operation
Affect of wound ischaemia on infection
potentiate by 10,000 fold
Low tissue oxygen affect
predispose infection
Halsteds principles
- aseptic technique
- sharp anatomic dissection
- Gentle tissue handling
- Careful haemostasis
- Avoid tension
- Obliterate dead space
A Sharp Gentle Cut Avoids Obstacles
4 layers of the abdominal wall
From exterior to interior, they are:
- external abdominal oblique (fibers run caudoventrally)
- internal abdominal oblique (fibers run cranioventrally)
- rectus abdominis (fibers run parallel to the linea alba)
- surrounded by fibrous sheath made up of aponeuroses from other abdominal muscles - transversus abdominis (fibers run transverse to linea)
What is the rectus abdominis layer surrounded by?
Internal and external rectus sheath.
Which layer of the abdomen holds sutures?
External rectus sheath of the rectus abdominis muscle
What structures are included in the spermatic cord?
Ductus deferens + its artery
Testicular artery
Pampiniform plexus of testicular veins
Cremaster artery and nerves
What is the pampiniform plexus?
Network of veins draining the testis located in the spermatic cord
Wraps around testicular artery
What is the vas deferens?
Takes sperm from epidiymis to external
Process of opening for a spey
- Cranial to caudal incision
- 10 blade through skin
- 15 blade through rest subcut (change blades, decrease staph infection)
- Get to abdominal wall and identify linea alba, pick it up with adson tissue forceps
- Reverse blade and stab into it to make a hole
- Switch to mayo scissors, gently lift and curt cranial then cut caudal
- Then in abdomen to find ovaries
- Tie off ligatures
- Do uterine body check for bleeders
- Close by linea alba to linea alba
a. But mostly we wont cut it straight
Strength holding layer of the muscle
Strength holding layer of muscle -> external layer
- Pointless grabbing internal layer and can enhance scar tissue
- Only need to get external sheath to external sheath together - exam
○ This is the holding layer
- Greyhounds that bleed -> we can get internal sheath and sandwich close to stop bleeding but very rare
How to search for a haemorrhage
Alert the anethetist and nurse and then move on to identify the source of the
bleeding
- Examine each pedicle first then move to the stump
- Incision extension may be necessary cranially and caudally to allow for better visualisation
- LEFT – identify the descending colon and grab the mesocolon to form a basket of the intestine and
move across to the right and visualise the dorsal abdomen, left ovarian pedicle and kidney. Inspect
for bleeding - RIGHT – identify the proximal or descending duodenum and create a basket with the mesoduodenum and lift intestines to the left and visualise the dorsal abdomen inspect the right
pedicle and kidney - The uterine stump is between the neck of the bladder and rectum so retrofex the bladder externally
to visualise the stump - once a region of interest is exposed then use suction or swabs to gently remove the excess blood
from the field. - Once located apply pressure with gauze for several minutes (up to 5 minutes) to reduce the rate of
haemorrhage and assist in maximising visualisation – correct the haemorrhage as necessary –
clamp and ligate - ALWAYS check for a secondary source of haemorrhage once fixed
