Soft Tissue Surgery Flashcards
Percentage of surgical gastrointestinal biopsies resulting in a final diagnosis
94%
Specific indications for renal biopsy
Protein-losing nephropathy and acute renal failure unresponsive to treatment
Contraindications for renal biopsy
Bleeding disorders, anemia, hypertension, pyelonephritis / abscess, hydronephrosis
Kidney biopsy - recommended side for dogs versus cats; recommended biopsy device/size
Cats – either kidney since they can be manually stabilized.
Dogs - right kidney because in contact with the caudate liver lobe (less mobile)
TruCut needle; 16G
Complications of renal biopsy
Hemorrhage (most common - 10% of dogs and 15% of cats), followed by arteriovenous fistula’s, cysts, infarction, thrombosis infection and fibrosis. Occasionally death.
Objective of renal biopsy (target tissue). What are we trying to avoid?
Cortical tissue only, avoid the medulla due to the risk of hemorrhage
Pancreatic biopsy - which limb to biopsy, why?
Right limb, away from the pancreatic ducts and duodenal vasculature
Laparoscopic pancreatic biopsy - biopsy cup or punch? Why?
Punch because it cuts instead of tearing the tissue
Bone biopsy technique _ instruments, location, precautions
Jamshidi or Michele Trephine; aseptic technique, stabs skin incision, redirect needle multiple times, use trocar to push simple out of needle, roll simple one slide for cytology/fungal analysis. Close skin with simple interrupted sutures. obtain radiographs to rule out fractures.
Accuracy of Jamshidi needle biopsies; main advantage over Michele Trephine
82.3%
Lower chance of iatrogenic fractures in comparison to Michele trephine
List the factors responsible for a higher incidence of dehiscence in esophageal surgery
Factors that contribute to a higher risk of dehiscence include lack of a serosal layer, presence of saliva and food/water boluses and constant motion from head/neck motion and respiration.
List and describe the four main types of esophageal hernias
- Sliding/axial hiatal hernias – characterized by laxity of the phrenicoesophageal ligaments, allowing gradual protrusion and dilation of the gastroesophageal junction into the thorax.
- Paraesophageal or rolling hiatal hernia – part of the gastric fundus herniates into the thoracic cavity
- Combination Sliding and paraesophageal hernia – combo laxity of phrenicoesophageal ligaments amd herniation of part of the gastric fundus
- Gastroesophageal intussusception – intussusception of the gastric cardia into the gastroesophageal junction
Current pathogenesis of canine perianal fistulas. Predisposed breed
Currently believed to be a multifactorial immune-mediated disorder. Other theories include poor local conformation, crypt fecalith impaction and abscessation or spread of infection from anal sacs. Colitis and enteral triggers may initiate the disorder, which is complicated by abscessation of glands and hair follicles around the anus. Breeds with a higher density of perianal glands, like the German Shepherd, are thus more predisposed to the disorder.
List seven different types of portosystemic vascular anomalies reported in dogs
- Portal v. to Cd Vena Cava
- Portal v. to Azygous v.
- Left gastric to Cd Vena Cava
- Splenic V to Cd Vena Cava
- Cr Mesenteric to Cd Vena Cava
- Cd Mesenteric to Cr. Vena Cava
- Gastro-duodenal to Cd. Vena Cava
Discuss the aetiopathogenesis of multiple acquired PSS including the three most common causes
Acquired PSS are believed to occur as a result of persistent portal hypertension leading to opening of vestigial fetal blood vessels. These are typically multiple, tortuous and extra-hepatic. Most connect a portal tributary to a renal vein or directly to the Cd Vena Cava adjacent to the kidneys. The most common causes of increased hydrostatic pressure are hepatic fibrosis, congenital non-cirrhotic portal hypertension and hepatic arteriovenous malformations.
Briefly describe what is known and the Zepp procedure
The Zapp procedure is a lateral ear canal ablation with the establishment of a “drain board“ to prevent the growth of hair into the ear canal
What are the three most common procedures utilized to treat refractory otitis externa
Lateral ear canal resection
Vertical ear canal ablation
Total ear canal resection
Most common neoplasm to arise from the ear canal of a dog with chronic otitis externa. What surgical procedures indicated for treatment?
Ceruminous gland adenocarcinoma; TECA
What procedure should always be performed at the same time as a TECA And why?
A ventral bulla osteotomy should always be performed to allow drainage. Patient with chronic otitis externa who require TECA Typically have concurrent otitis media. Not performing a ventral bulla osteotomy can be disastrous.
List the most common complications with TECA procedures (8)
Infection
Hemorrhage
Ipsilateral head tilt ( aggressive curettage of epitympanic recess and promoltory of the tympanic cavity). Resolves in 2-3 weeks
Facial nerve paralysis (excessive traction applied to the facial nerve during surgery). May lead to dry eye, requiring the application of lubricant for several weeks
Horner’s syndrome (Maybe present preop or occur as a result of trauma to the facial nerve)
Abscess
Chronic fistulas (Incomplete removal of ear canal epithelium)
Avascular necrosis of the pinna (caused by inadvertent occlusion of branches of the caudal auricular artery by sutures. Possibly avoided by placing simple interrupted sutures instead of continuous or horizontal mattress patterns)
Muscles used by brachycephalic animals to facilitate breathing
Geniohyoid, genioglossus and sternohyoid,
T2-weighed MRI Appearance of the bulla in a patient with otitis media
Otitis media is easily recognized on MRI images as a hyperintensity with the bulla on T2-weighted images
Explain the basic biologic rationale for the use of porcine submucosal membrane in surgical wounds (BioSIS)
“Small intestinal submucosa provides a scaffold of biocompatible material that promotes cellular ingress of fibroblasts and neovascularization from adjacent tissue.”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
What are the 4 naturally encountered cells in the dermis?
Fibroblasts, macrophages, plasma cells and mast cells
What are the 6 panniculus muscles of the dog?
cutaneous trunci, platysma, sphincter colli superficialis, sphincter colli profundus, preputialis, supramammarius muscles),
What are the four phases of wound healing?
Inflammation, debridement, repair maturation
What range (days) is considered the “lag phase” wound healing? Why
The first 3 to 5 days are the lag phase of wound healing because inflammation and debridement predominate and wounds have not gained appreciable strength
Are both neutrophils and monocytes essential for wound healing? Explain
Monocytes are essential for wound healing; neutrophils are not. Monocytes are major secretory cells synthesizing growth factors that participate in tissue formation and remodeling. Monocytes become macrophages in wounds at 24 to 48 hours. Macrophages secrete collagenases, which remove necrotic tissue, bacteria, and foreign material.
Are lymphopenia or neutropenia likely to affect wound healing? How about impaired macrophage function?
Although healing is severely impaired when macrophage function is suppressed, neutropenia and lymphopenia do not inhibit healing or the development of wound tensile strength in sterile wounds.
When does the repair phase of healing begin? Name the crucial steps of this phase
3 to 5 days post-injury
Macrophages stimulate DNA and fibroblast proliferation
Fibroblasts originate from mesenchymal cells and migrate along fibrin strands ahead of new capillary beds, depositing collagen, elastin and proteoglycans to form fibrous tissue. collagen deposition is originally haphazard but begins to follow skin tension lines after the 5th day. Wound fibrin disappears as collagen is deposited.
Capillaries invade wounds behind migrating fibroblasts (angiogenesis), leading to the formation of granulation tissue.
Epithelialization begins within 4 to 5 days in wounds with adequate granulation bed (or immediately in well-apposed surgical wounds) under the influence of growth factors produced by platelets, macrophages and fibroblasts. Epithelial cells follow collagen fibers.
Wound contraction begins after significant fibroblastic invasion of the wound, but is independent of epithelialization. It stops when wound edges meet, tension is excessive or myofibroblasts are inadequate. If contraction stops before granulation tissue is covered, epithelialization may continue and cover the wound.
Where can myofibroblasts be found?
Granulation tissue
When does the debridement phase of healing begin? Name the crucial events of this phase
Hours to 3-5 days
 Chemoattractants encourage neutrophils (6 hours) and monocytes (12 hours) to appear in the wound, preventing infection and phagocytizing organisms and debris.
Monocytes synthesize growth factors that participate in tissue formation and remodeling (essential cell line for healing). They also recruit mesenchymal cells, stimulate angiogenesis and modulate matrix production in wounds.
Platelets release growth factors important for fibroblastic activity
Lymphocytes appear late in the debridement phase and improve the rate and quality of tissue repair
When does the inflammatory phase of healing begin? What are the crucial events?
Begins immediately after injury and lasts 3 to 5 days
Characterized by increased vascular permeability, chemotaxis of circulatory cells, release of cytokines and growth factors and cell activation (macrophages, neutrophils, lymphocytes and fibroblasts)
Blood vessels initially constrict to limit hemorrhage (5 to 10 minutes), then dilate to leak fibrinogen and clotting elements.
Platelets release potent chemo attractant in the growth factors necessary for later stages of healing
Favorite and plasma translates fill wounds and plug lymphatics, localizing inflammation and “gluing“ wound edges together.
A blood clot offers a low degree of world strength but acts as a barrier for infection
Platelets, mast cells and macrophages continue to secrete growth factors and cytokines and initiate/maintain the proliferative phase of healing
Epithelial migration also occurs along suture tracts, which may lead to a foreign body reaction, sterile abscess, scarring, or all of these. How can this be avoided?
Early removal of sutures
What factors are responsible for stopping wound contraction?
Wound contraction stops when wound edges meet, when tension is excessive, or when myofibroblasts are inadequate
When does the maturation phase of healing begin? What are the crucial events?
It begins when collagen has been adequately deposited in the wound (typically around 20 days) and may continue for years.
Granulation tissue cellularity and collagen content decrease.
Collagen fibers remodel and re-orient improving wound strength along the lines of stress
Non-functional oriented collagen fibers are degraded by proteolytic enzymes (MMPs) secreted by macrophages and other cells
The most rapid gain and wound strength occurs between seven and 14 days after injury, balloons only ringing about 20% of their final strength in the first three weeks. Only 80% of the original strength will be ever regained.

When does the quickest gain in wound strength occur in the healing process? What is the maximum strength (percentage) wound will ever regain?
During the maturation phase, between 7 and 14 days post wound
80%
What are the main advantages of a moist wound environment? Any disadvantages?
1) promotes granulation tissue and faster epithelialization
2) promotes autolytic debridement by endogenous enzymes (does not affect healthy tissue); occurs within 72 to 96 hours
3) Low oxygen environment promotes macrophage penetration and activity, as well as angiogenesis and reepithelialization
4) resists infection because white blood cells are abundant in better able to promote phagocytosis. If receiving antibiotics, the drug concentrates in the fluid environment
5) no scab formation, therefore white blood cells are not trapped in the scab but rather migrate freely within the wound bed
6) faster epithelialization. Epithelial cells have a shorter distance to travel and do not dissicate.
7) moist wounds are less painful and pruritic and form less scar.
Disadvantages: bacterial colonization (not infection), folliculitis and a maceration of the wound border
What are the two main advantages associated with the use of bandages in the context of wound care?
Warmth (30°C [86°F]) allows wounds to heal more quickly and with greater tensile strength than if they are at room temperature. A moist wound promotes recruitment of vital host defenses and cells, encouraging wound healing. Bandages help keep wounds warm and moist.
Poor wound blood supply, such as caused by trauma, tight bandages or wound movement slows wound healing. This is also the case for fluid accumulation (seromas). Explain how this occurs
Macrophages resist hypoxia, but epithelialization and fibroblastic protein synthesis are oxygen dependent. Collagen synthesis requires 20 mm Hg partial pressure of oxygen (pO2). HBOT increases tissue oxygen and produces more rapid gains in wound strength. Accumulation of fluid in dead space delays healing because the hypoxic fluid environment of a seroma inhibits migration of reparative cells into wounds. Fluid mechanically prevents adhesion of flaps or grafts to the wound bed.
Name four types of growth factors identified in the process of wound healing
platelet-derived growth factor
epidermal growth factor
fibroblast growth factor
type-transforming growth factor.
Describe the role of fibronectin in the process of wound healing
Fibronectins are glycoproteins critical to wound healing. They stimulate cell attachment and migration and are found in soluble form in plasma and in insoluble form in connective tissue matrix. Macrophages, endothelium, fibroblasts, and epithelium synthesize and release fibronectin.
Describe the effect of chemotherapeutic drugs and radiation in the context of wound healing. How long should these therapeutic modalities be avoided after a surgical procedure?
Most chemotherapeutic drugs (e.g., cyclophosphamide, methotrexate, and doxorubicin) inhibit wound healing. Radiation therapy can profoundly inhibit wound healing, depending on dose and time of exposure relative to the time of injury. It reduces the quantity of blood vessels, affects collagen maturation, and causes increased dermal fibrosis. Therefore chemotherapeutic drugs and radiation therapy should be avoided for 2 weeks after surgery.
Describe the “golden period” in the context of wound healing and how it relates to infection.
The “golden period” is the first 6 to 8 hours between wound contamination at injury and bacterial multiplication to greater than 10 ^5CFU per gram of tissue. A wound is classified as infected rather than contaminated when bacterial numbers exceed 105 CFU per gram of tissue.
Define an avulsion skin wound
Avulsion wounds are characterized by the tearing of tissues from their attachments and the creation of skin flaps
Describe the ideal approach to a severely traumatized and contaminated wound older than 8 hours
Severely traumatized and contaminated wounds, wounds older than 6 to 8 hours, or infected wounds should be treated as open wounds to allow debridement and reduction of bacterial numbers. Most wounds are surgically apposed after infection has been controlled; however, some wounds heal by contraction and epithelialization (healing by secondary intention).
Explain the advantage of adding Tris-EDTA to a 0.05% chlorhexidine solution for wound lavage. what are the potential disadvantages of the solution?
Makes bacteria more susceptible to destruction by lysozymes, antiseptics, and antibiotics. Rapidly lyses P. aeruginosa, E. coli, and Proteus vulgaris
Increases antimicrobial effectiveness approximately 1000-fold
Precipitates in electrolyte solutions
More concentrated solutions are cytotoxic and may slow granulation tissue formation
Corneal toxicity
0.05% Chlorhexidine (1 part stock solution to 40 parts sterile water or LRS) or (~25 mL stock solution per liter) is frequently added to wound lavage solutions. What are the advantages and disadvantages of this practice?
Wide antimicrobial spectrum
Good residual activity
Not inactivated by organic matter
Precipitates in electrolyte solutions
More concentrated solutions are cytotoxic and may slow granulation tissue formation
Proteus, Pseudomonas, and Candida are resistant
Corneal toxicity
Bacteria are effectively removed from the wound surface by high-pressure lavage. What is the currently recommended pressure and method for a small animal practice setting?
The most consistent delivery method to generate 7 to 8 psi is a 1-L bag of fluid within a cuff pressurized to 300 mm Hg; 18G needle.
What are the proposed benefits associated with the use of low level laser therapy for the treatment of wounds?
Low-level laser therapy (LLLT) has been advocated to stimulate wound healing in chronic wounds by shortening the inflammatory phase and enhancing the release of factors that stimulate the proliferative stage of repair. Increased collagen deposition and endothelial cell, fibroblast, and myofibroblast proliferation are the most significant effects.
Describe the advantages of autolytic debridement of wounds. How is it done and what is the main disadvantage?
Autolytic Debridement
Autolytic debridement is accomplished through creation of a moist wound environment to allow endogenous enzymes to dissolve nonviable tissue. It is often preferred over surgical or bandage debridement in wounds with questionable tissue viability, as it is highly selective for devitalized tissue and markedly less painful than other methods of debridement; however, it is a much slower process. Autolytic debridement is accomplished with hydrophilic, occlusive, or semiocclusive bandages (see pp. 195–196), which allow wound fluid to remain in contact with nonviable tissue.
What are the 5 categories of wound debridement?
Surgical debridement
Autolytic debridement
Bandage (mechanical) debridement
Enzymatic debridement
Biosurgical debridement
Ideally, what criteria should be utilized to decide on the timing of skin grafting as it pertains to infection?
Ideally, quantitative bacterial counts should be performed before grafts or flaps are placed over granulating wounds. Reconstruction should be delayed if bacterial counts are greater than 105 CFU per gram of tissue.
Describe the criteria for the use of antibiotics in minimally or moderately contaminated wounds less than 6–8 hours old versus severely contaminated wounds
Selective use of antibiotics may help prevent or control integument infections after injury or surgery. Minimally or moderately contaminated wounds less than 6 to 8 hours old may be cleaned and closed or treated without antibiotics. Severely contaminated, crushed, or infected wounds, or wounds older than 6 to 8 hours, typically benefit from antibiotic therapy. Contaminated wounds and those with established infection should be cultured before antibiotics are given, and antibiotic selection should ultimately be based on culture and susceptibility testing.
What are the advantages and disadvantages associated with the use of topical antibiotics versus anti-septic‘s in wound management?
Advantages of topical antibiotics over antiseptics in wound management include selective bacterial toxicity, efficacy in the presence of organic material, and combined efficacy with systemic antibiotics. Disadvantages include expense, narrower antimicrobial spectrum, potential for bacterial resistance, creation of superinfections, systemic or local toxicity, hypersensitivity, and increased nosocomial infections. Antibiotic solutions are preferable to ointments and powders. Ointments liberate antibiotics slowly and may be occlusive, promoting growth of anaerobic bacteria. Powders act as foreign bodies and should not be used.
Advantages and disadvantages of triple antibiotic ointment; typical formulation; Roll of zinc
Triple antibiotic ointment (bacitracin, neomycin, polymyxin) is effective against a broad spectrum of pathogenic bacteria commonly infecting superficial skin wounds. However, its efficacy against pseudomonads is poor. Zinc bacitracin is responsible for enhancing reepithelialization of wounds but can retard wound contraction. Because these drugs are poorly absorbed, systemic toxicosis (nephrotoxicity, ototoxicity, neurotoxicity) is rare. The ointment is more effective for preventing infections and treating mildly infected wounds.
Advantages of Silver Sulfadiazine dressings
Effective against gram-positive, gram-negative and fungi
Serves as anti-microbial barrier, penetrates necrotic tissue
Enhances epithelialization
Better is combined with aloe vera (less suppression of fibroblasts and polymorphonuclear cells)
Can be left in place for seven days
Promotes a hydrophilic environment conducive to face healing
Absorbs exudate
Describe the role of gentamicin sulfate in the treatment of infected wounds in on wounds to be grafted
Gentamicin sulfate is available as a 1% ointment or powder (Garamycin), but solutions are preferred. Products with an oil-in-water cream base slow wound contraction and epithelialization. It is especially effective in controlling gram-negative bacterial growth (Pseudomonas spp., Escherichia coli, Proteus spp.). It is often used before and after grafting and for wounds that have not responded to triple antibiotic ointment. However, gentamicin in an isotonic solution does not inhibit contraction, and it promotes epithelialization.
Describe the use of cefazolin as a topical agent in Infected wounds
 effective against gram-positive and some gram-negative organisms
Provides a high-level of antibiotic in wound fluid
Prolonged minimum inhibitory concentration in wounds in comparison to systemic administration
95% bioavailable and rapidly absorbed, systemic levels equal wound fluid levels within one hour
What is the most common use and advantages of Mafenidine
Mafenide (hydrochloride or acetate) is a topical sulfa compound available as an aqueous spray most commonly used for burn wounds in humans. It has a broad spectrum against many gram-positive and gram-negative bacteria, including Pseudomonas spp., Clostridium spp., and methicillin-resistant Staphylococcus aureus; it is particularly useful on severely contaminated wounds.
List the potential benefits of aloe vera in the treatment of wounds; when should not be applied
Effective against pseudomonas
Antifungal
Anti-prostaglandin and anti-thromboxane properties help maintain vascular patency
Stimulates fibroblastic replication
Penetrates tissue and provides analgesia
Active ingredients such as allantoin stimulate epithelial growth
Counteract the inhibitory effects of Silver sulfadiazine when combined
Should not be applied to full thickness wounds because it suppresses inflammation
Proposed benefits of Acemannan
Acemannan stimulates macrophages to secrete interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF-α), which enhance fibroblast proliferation, neovascularization, epidermal growth and motility, and collagen deposition to form granulation tissue. Acemannan may also bind growth factors, prolonging their stimulating effect on formation of granulation tissue.
The greatest effects are seen in the first 7 days of application. Excess granulation tissue can occur, especially with the freeze-dried form, which inhibits wound contraction.
List 6 benefits associated with the use of honey in the treatment of wounds
Reduces edema
•
Reduces inflammation
•
Accelerates wound debridement
•
Promotes granulation tissue formation
•
Accelerates epithelization
•
Antimicrobial
When and how should honey be used for the treatment of wounds?
Should be applied early in the course of wound healing and discontinued once a healthy granulation bed is present.
Medical grade unpasteurized honey should be used, ideally as an impregnated sterile gauze covered by thick absorbent bandage. Bandages should be replaced once to three times daily depending on the amount of Strikethrough.
What is the proposed rationale (mechanism) that justifies the use of hydrolyzed bovine collagen in the treatment of wounds? In what phase is it best utilized and for what purpose?
Hydrolyzed bovine collagen (Woun’Dres Collagen Hydrogel, Collasate) has hydrophilic properties that help create a moist environment for autolytic debridement in early phases of wound healing and an optimal environment for epithelialization in latter stages. The collagen matrix provided serves as a lattice for ingrowth of fibroblasts, thus facilitating the repair phase of wound healing. It is probably most effective when used in the late inflammatory and early repair phases of healing to accelerate epithelialization.
What is the recommended dilution of chlorhexidine for wound lavage? How to prepare it?
0.05%
What part of 2% stock solution to 40 parts of wound lavage fluid (add 25 ML of 2% stock solution to 1 L of LRS)
What are the three main types of bacteria known to be resistant to chlorhexidine?
Pseudomonas, Proteus and candida
Chlorhexidine solution is known to be toxic to this tissue at any concentration. What is it?
Cornea
Name seven disadvantages associated with the use of povidone iodine for the treatment of wounds
Strongly acidic (pH 3.2)
Requires frequent reapplication, residual effect 4 to 6 hours
Inactivated buy organic matter such as blood or serous exudate
Absorbed through the skin and mucous membranes. Frequently application may lead to transient thyroid dysfunction
Damages tissue and potentiates infection
Causes contact hypersensitivity in over 50% of dogs
Toxic to fibroblasts
What is the role of hydrogen peroxide in the management of wounds ?
SHOULD NOT BE USED
Hydrogen peroxide, even in low concentrations, damages tissue and is a poor antiseptic. It is an effective sporicide; therefore it may be beneficial if clostridial spores are suspected. Hydrogen peroxide dislodges bacteria and debris from wounds by effervescent action.
What is Dakins solution? What is its role in the management of wounds?
SHOULD NOT BE USED
Dakin’s solution is a 0.5% solution of sodium hypochlorite (1 : 10 dilution of laundry bleach). It releases free chlorine and oxygen into tissue, killing bacteria and liquefying necrotic tissue. However, even at half or quarter strength, Dakin’s solution is detrimental to neutrophils, fibroblasts, and endothelial cells and should not be used as a wound lavage solution.
What are the five cutaneous muscles encountered in the dog?
panniculus, preputialis, supramammarius, platysma, and sphincter colli muscles
List 5 advantages associated with the use of negative pressure wound therapy
Increases blood flow
•Reduces edema
•Increases rate of granulation tissue formation
•More rapid reduction in numbers of microorganisms
•Removal of exudate
•Greater flap survival
Regarding the use of Tourniquets– what criteria should be observed regarding pressure and duration?
Pneumatic tourniquets with pressures below 300 mm Hg for less than 3 hours should be used.
List 4 contraindications to the use of tourniquets
Local separation
Deep venous thrombosis
Neoplasia
Trauma
Vascular injury or circulatory compromise
List 5 potential complications associated with the use of tourniquets
Ischemia, hypoxia, tissue acidosis, neurapraxia, muscle damage
List 8 factors that may affect the decision not to close wounds following injury
- Amount of time that has elapsed since injury. Wounds older than 6 to 8 hours are initially treated with bandages.
- Degree of contamination. Obviously contaminated wounds should be thoroughly cleansed and initially treated with bandages.
- Amount of tissue damage. Wounds with substantial tissue damage have reduced host defenses and are more likely to become infected; therefore they initially should be treated with bandages.
- Completeness of debridement. Wounds should remain open if the initial debridement was conservative and if further debridement is necessary.
- Status of the wound’s blood supply. A wound with questionable blood supply should be observed until the extent of nonviable tissue is determined.
- The animal’s health. Animals unable to tolerate prolonged anesthesia are best treated with bandages until their health improves.
- Extent of tension or dead space. If excessive tension or dead space is present, wounds should be bandaged to prevent dehiscence, fluid accumulation, infection, and delayed wound healing.
- Location of the wound. Large wounds in some areas (e.g., limbs) are not amenable to closure.
List six desirable characteristics of wound dressings
Removes exudates and toxic components
•Maintains high humidity at the wound-dressing interface
•Allows gaseous exchange
•Provides thermal insulation
•Relieves pain
•Protects from secondary infection
•Protects from particulate or toxic contaminants
•Allows dressing removal without wound trauma
Give five examples of hydrophilic contact layers that can be used in bandages
Hypertonic saline
•Calcium alginate
•Polyurethane foam
•Hydrogel
•Hydrocolloid
•Some topical medications
List three products or treatment modalities known to enhance wound contraction
Acemannan
Tripeptide copper complex
Occlusive hydrogel dressings
Equine amnion
Pulsed electromagnetic field radiation
Adjustable horizontal mattress sutures
Skin stretchers
List five products or treatment methods known to inhibit wound contraction
Corticosteroids
Silver sulfadiazine
Mafenide acetate
Hydrocolloid dressings
Porcine small intestine submucosa
Thick skin grafts or flaps
Name three products that can be added to a wound that is already dry
Hydrogel
Hypertonic saline dressing
Medicinal Honey
What product can be added to a wound in order to reduce swelling and Improve perfusion?
Hypertonic saline dressing
Name four methods that can be utilized to protect the skin surrounding a wound from moisture and trauma
Moisture barrier ointment
Skin sealant
Transparent film dressing
Bandage
Discuss the recommended use for hypertonic saline bandages. What’s the best application, for how long? What is it typically followed by?
These dressings quickly convert necrotic wounds to moderately exudating and granulating wounds. Debridement is nonselective, so use is limited to one or two applications; these dressings are usually followed with placement of alginate, hydrogel, or foam dressings once granulation tissue has begun to form. Hypertonic saline bandages should be changed at least every 24 hours to prevent saline dilution and wound desiccation.
Which nonocclusive, non-adherent, hydrophilic, moisture retaining dressing has good hemostatic properties but should not be applied directly over muscle or tendon?
Calcium alginate
How much lengthening (in percentage) can be gained when he Z-plasty with 45° limbs is used versus the recommended 60° limbs?
The angles of the Z can vary between 30 degrees and 90 degrees, but 60 degrees is advised. Larger angles give more length gain (45 degrees gives approximately a 50% increase; 60 degrees approximately a 75% increase). Length is gained along the original central limb of the Z when the flaps of the Z are transposed
Name two different methods for closure or a circular skin defect
Combined V technique (Does not remove additional normal skin)
Bowtie technique (removes 36% additional skin, so adequate when dog ears are present)
Explain the difference between a subdermal plexus flap and a Axial Pattern flap
A specific flap may be classified in more than one way. Most flaps are called subdermal plexus flaps; however, those with direct cutaneous vessels are called axial pattern flaps.
What is the difference between a transposition flap and an interpolation flap?
The flap is created in the same way as a transposition flap except that the length of the interpolation flap must include the length of the intervening skin segment
Name 5 muscles that can be sacrificed in the making of a myocutaneous or muscular flap without functional deficits
latissimus dorsi
trapezius
cutaneous trunci
gracilis
semitendinosus
What most important criteria must a surgeon observe when preparing a myocutaneous flat? (As it pertains to assuring skin survivability).
Development of myocutaneous flaps requires the presence of direct cutaneous arteries exiting the muscle surface to supply the overlying skin.
Which muscles can be easily used to create muscle flaps for the repair of esophageal and laryngeal defect?
Sternohyoideus and sternothyroideous muscles
What muscle flap can be used in the repair of pre-pubic tendon ruptures or femoral hernias when tissue trauma, retraction and fibrosis preclude adequate anatomic reposition?
Cranial sartorius muscle flap
What muscle can be used to create a muscle flap to repair femoral trochanteric ulcers? This muscle has two bellies in the dog but only one belly in the cat
Cranial sartorius muscle flap
The caudal sartorius muscle flap can be used to repair tibial or metatarsal area defects. What is the difference in blood supply between this valley and its cranial counterpart?
The caudal sartorius receives its blood supply from the Saphenous artery and medial saphenous vein, while the cranial sartorius derives its entire blood supply from the femoral artery/vein
What muscle flap can be used to repair injuries affecting the antebrachial, carpals and metacarpals areas?
The humeral head of the flexor carpi ulnaris muscle
What muscle flap can be used to close orbital nasal defects or to improve cosmesis after orbital exenterations?
Temporalis muscle flap
What is the origin and attachment of the greater omentum? Where does it derive its blood supply?
It attaches ventrally to the greater curvature of the stomach and dorsally to the pancreas and spleen. The omental blood supply is from peripheral vessels of the right and left gastroepiploic arteries.
Describe the Plasmatic Imbibition phase of grafting
The process by which graft or nourished immediately after implantation. Graft vessels dilate and pull fibrinogen-free, Serum like fluid and cells from the graft bed into the dilated vessels of the graft. Absorption of hemoglobin containing cells give the graft a bluish black color. Edema peaks at 72 hours and improves as lymphatic drainage/venous return are reestablished.
Describe inosculation
Second phase of grafting, when blood vessels from the graft bed and the graft itself anastomose. This may begin as early as the first day of grafting. Vascular buds from the graft bed follow the fibrin scaffold to meet pre-existing severed graft vessels. Blood flow is initially sluggish but approach is normal by the 5-6 day.
What are the most common causes of graft failure?
Separation from the graft bed, infection and movement
Explain how infection is detrimental to graft survival. Include the role of specific bacteria commonly associated with infection/graft failure
Infection is detrimental to graft survival because bacteria may cause dissolution of fibrin attachments or produce sufficient exudate to lift a graft from the recipient bed. Plasminogen activators and proteolytic enzymes released by bacteria disrupt the fibrin seal. β-Hemolytic streptococci and pseudomonads produce large amounts of plasmin and proteolytic enzymes. Pseudomonas spp. also produce elastase, which breaks down elastin; elastin adheres to fibrin, facilitating graft adhesion.
What ointment is frequently used for the care of burns for It’s excellent activity against gram-positive and gram-negative bacteria and candida?
Silver sulfadiazine
What topical product is frequently used on partial thickness burns for its ability to promote reepithelization?
Aloe vera
What kind of contact layer would you recommend for a burn with thick/dry Eschar?
Hypertonic saline for hydrogel dressing with silver sulfadiazine and biguanide impregnated gauze
What contact layer would you recommend for a burn without eschar but still requiring granulation?
Hydrogel or calcium alginate and biguanide impregnated gauze
What contact layer would you recommend for a burn with healthy granulation bad but that still requires epithelization?
What are urethane foam and biguanide impregnated gauze
Describe the typical treatment of acute frost bite. Describe the typical appearance of a frozen versus thawed tissue in the expected timeline for the healing process
The affected body parts should be rapidly rewarmed in warm water (39°C–42°C [102°F–107.6°F]) for approximately 20 minutes to improve circulation. Affected areas become erythematous and edematous, form large vesicles, and are often painful, necessitating analgesics (see Chapter 13). Topical aloe vera or silver sulfadiazine should be applied to the affected areas. Bandages are used to prevent self-trauma. Conservative therapy should be continued until viable tissue can be distinguished from nonviable tissue (i.e., 3–6 weeks). Necrotic tissue should then be debrided and the area reconstructed if necessary. Healing may be complete beneath the mummified tissue.
What are the four degrees of radiation injury?
cutaneous erythema, (2) superficial epidermal (dry) desquamation, (3) moist desquamation from loss of basal layers of epidermis, and (4) necrosis with dermal destruction and irreversible ulceration.
What main considerations should be made when managing a burn wound caused by external beam radiation?
Manage burn wounds in the usual manner for the first 14 days (hydrophilic bandages, hydrocolloid with acemannan, silver sulfadiazine)
Debride chronic radiation injury areas conservatively, removing only necrotic tissue. Submit all tissue for histopathology.
Avoid free grafts as the vascular supply of the recipient bed may not be healthy enough to support inosculation. Favor vascularized myocutaneous, cutaneous, muscle, or omental flaps.
List the five most common aerobic and two most common anaerobic bacterial isolates from dog-bite wounds
BEPES-CC
Pasteurella multocida, Staphylococcus spp., Enterococcus spp., Bacillus spp., and E. coli; common anaerobic isolates include Clostridium spp. and Corynebacterium spp
What are the general guidelines regarding the management of dog bite wounds?
Thoroughly lavage and explore puncture wounds to determine depth/extent. Explore body cavities if wounds penetrate. Ultrasonography and radiography can help but may also grossly underestimate the extent of the injury.
Manage with hydrophilic bandages for 3 to 5 days before closure.
Make sure to debride all divided lysed and necrotic tissue before closure. Consider the use of active or passive drains.
Obtain cultures if signs of infection are present. Otherwise provide coverage with beta-lactam antibiotics for approximately 14 days.
Explain the reasons why the oral cavity and oropharyngeal mucosa heal more rapidly than skin
The oral cavity and oropharyngeal mucosa heal more rapidly than skin because phagocytic activity (primarily monocytes rather than polymorphonuclear leukocytes) and epithelialization are more extensive and occur earlier in mucosa. An excellent mucosal blood supply, warmer temperatures, higher metabolic activity, and a higher mitotic rate contribute to rapid healing of mucosa. Apposed wounds reepithelialize within a few days, and defects heal by second intention.
Explain the anatomic difference between the primary and secondary palate; What are the names given to the incomplete closure of each of those anatomical regions?
The primary palate consists of the lip and pre-maxilla. Incomplete closure is known as primary cleft or cleft lip (harelip). The secondary palate consists of the hard palate and soft palate. Incomplete closure is known as cleft palate.
Give 5 possible causes for incomplete closure of either the primary or secondary palate.
Genetics (recessive or irregular dominant, polygenic traits)
Nutritional (inadequate Folic acid)
Hormonal (steroids)
Mechanical (in utero trauma)
Toxic (including viral)
List four dog breeds predisposed to primary or secondary palatal defects
Boston terriers, Pekingese, Lhasa apso, bulldog
What cat breed has a higher incidence of primary or secondary palatal defects?
Siamese
What conditions are frequently observed in association with primary or secondary palatal defects?
Aspiration pneumonia, middle ear disease
Describe the technique for a mandibular and sublingual salivary gland excision
“Locate the mandibular salivary gland between the linguofacial and maxillary veins as they join the external jugular vein (Fig. 18.36A). Incise the skin, subcutaneous tissue, and platysma muscle from the angle of the mandible caudally to the external jugular vein to expose the fibrous capsule of the mandibular gland (see Fig. 18.36B). Avoiding the branch of the second cervical nerve that crosses the capsule, incise the capsule and dissect it away from the mandibular and monostomatic sublingual salivary glands. Ligate the artery (branch of the great auricular artery) and vein as they are “encountered on the dorsomedial aspect of the gland. Continue dissecting cranially, following the mandibular duct, sublingual duct, and polystomatic sublingual glands toward the mouth (see Fig. 18.36B). Incise the fascia between the masseter and digastricus muscles. Expose the entire mandibular and sublingual salivary gland complex by retracting the digastricus muscle and applying caudal traction on the mandibular gland. If necessary, perform digastricus muscle myotomy or tunnel the caudal sublingual gland duct complex under the digastricus muscle to improve visualization. Dissect (digital and sharp) rostrally until the lingual branch of the trigeminal nerve is identified and only ducts remain in the complex. Avoid traumatizing the lingual or hypoglossal nerves. Try to identify the gland-duct defect causing the mucocele, because failure to identify this defect may indicate that the mucocele originated from the contralateral gland-duct complex (Fig. 18.37). Ligate and transect the mandibular sublingual gland-duct complex just caudal to the lingual nerve. “Lavage the surgical site before closure. Appose the digastricus muscle if it has been incised with horizontal mattress or cruciate sutures. Close the dead space with a few sutures in the capsule and deep tissue. Routinely appose superficial muscles, subcutaneous tissue, and skin. Following excision, submit the glands and ducts to rule out neoplasia and submit a portion of the mucocele wall to rule out congenital cysts.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Describe the blood supply to the esophagus
“The vascular supply of the cervical esophagus is from branches of the thyroid and subclavian arteries. Bronchoesophageal arteries and segmental branches from the aorta supply the thoracic esophagus. The abdominal esophagus is supplied by branches from the left gastric and left phrenic arteries. Intramural branches ramify and anastomose in the submucosal layer. ”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
List 4 reasons why healing of the esophagus can be challenging
no serosa
no Omentum
segmental blood supply
constant motion and bolus distention
intolerance to longitudinal stretching”
List 8 ways to decrease the chance of complications during/after esophagotomies
“• Choose the most advantageous approach
• Preserve vasculature; dissect sparingly
• Suction the lumen prior to incising
• Make incision through healthy tissue
• Make longitudinal esophagotomy incisions
• Inspect for contralateral perforations or necrosis
• Resect only 3 to 5 cm during esophagectomy
• Incorporate submucosa with all sutures
• One-layer closure—keep knots extraluminal
• Two-layer closure—inner layer: intraluminal knots; outer layer: extraluminal knots
• Tension-relieving techniques: circumferential myotomy, gastric advancement, phrenic nerve interruption, pexy sutures
• Seal and support with a harvested omental flap or muscle flap
• Treat esophagitis with proton pump inhibitors and/or gastric prokinetics”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What are the 4 main factors necessary for optimal healing of enterotomies and intestinal anastomosis?
Preservation of blood supply
Avoidance of tension
Maintenance of adequate cardiac output
Optimal oxygen saturation levels
What are the key differences between the healing of the skin versus the G.I. tract?
Shearing forces
Bacterial burden
Blood supply during shock (PaO2)
“Gastrointestinal wound healing differs from healing of the skin in several other ways as well. First, in cutaneous wounds, shear stress is either minimal or can be minimized by bandaging or activity restriction. In the gastrointestinal tract, however, increased intraluminal pressure during peristalsis can inflict significant shear forces upon the healing intestinal wound. Second, the bacterial flora of the gastrointestinal tract is polymicrobial, containing both aerobic and anaerobic bacteria that can significantly and adversely impact anastomotic healing. Skin flora is largely aerobic, and numbers can be reduced by cleansing; thus, healing will not be as negatively impacted. Third, during states of hypovolemic shock, vascular perfusion to the gastrointestinal tract decreases, and this may negatively impact anastomotic healing; vascular perfusion to the skin, however, is relatively constant.62,147 In a retrospective study of 225 dogs undergoing surgery of the gastrointestinal tract, intraoperative hypotension was identified as being significantly associated with the development of septic peritonitis and death following surgery.62 In addition to vasomotor control of perfusion, arterial tissue oxygen pressure (PaO2) is critical for wound tissue oxygenation. Mature collagen formation fails when PaO2 is below 40 mm Hg. Below 10 mm Hg, impairment of the critical components of wound healing (i.e., angiogenesis, epithelialization[…]”
Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.
Name for tension relieving techniques that can be utilized in the esophagus
Circumferential myotomy
Gastric advancement
Phrenic nerve interruption
Pexy sutures
Briefly describe the approach to the esophagus at the level of the heart
“Make an incision through the right fourth or fifth intercostal space. Identify and transect or retract the latissimus dorsi, serratus ventralis (dashed line), scalenus, and external abdominal oblique muscles. (B) Incise the intercostal muscles. (C) Expose the thoracic viscera.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Describe the approach to the caudal esophagus via left caudal lateral approach
“Position the patient in lateral recumbency as described previously for cranial lateral thoracotomy. Perform a caudal lateral thoracotomy (Fig. 18.45A). Although the caudal esophagus can be approached through an incision in either the left or right eighth or ninth intercostal space, the left ninth space is preferred. Expose the caudal esophagus by transecting the pulmonary ligament and packing the caudal lung lobes cranially. Identify the esophagus, which is just ventral to the aorta (see Fig. 18.45B). Identify the dorsal and ventral vagal nerve branches on the lateral aspect of the esophagus and protect them.
”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What is the preferred side and intercostal space to approach the caudal esophagus?
“left ninth space is preferred”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
Describe the placement of a two layer simple interrupted closure pattern for Esophagotomy. Include which layers must be included in in what sequence
“Place each suture approximately 2 mm from the edge and 2 mm apart. Incorporate the mucosa and submucosa in the first layer of a two-layer simple interrupted closure. Place sutures so that the knots are within the esophageal lumen (Fig. 18.46A–B). Incorporate the adventitia, muscularis, and submucosa in the second layer of sutures with the knots tied extraluminally”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
List some of the techniques utilized to support or patch an esophageal surgery site
“Augmentation of esophagotomy or esophagectomy sites with omentum or muscle can aid healing by supporting, sealing, and revascularizing the surgical site. Muscle pedicles from the sternohyoid, sternothyroid, intercostal, diaphragm, or epaxial muscles can be mobilized and sutured over the primary repair or esophageal defect (Fig. 18.50A). As an alternative, omentum can be mobilized from the abdomen, brought through a rent in the diaphragm, and sutured over the esophageal site (see Fig. 18.50B). Pedicles from the gastric wall and pericardium have also been used.”
Excerpt From
Small Animal Surgery E-Book
Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS
https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984
This material may be protected by copyright.
What is the most common clinical signs associated with esophageal obstruction?
Acute onset of regurgitation
Describe the most adequate contact layers for burn wounds with the following characteristics: 1) Eschar present; needs softening and debridement 2) Eschar gone; needs further debridement 3) Eschar gone; needs granulation 4) Needs epithelialization
Define primary wound closure, delayed primary closure, Secondary closure, and second intention healing
Primary closure - Also known as first-intention healing. Involves immediate
apposition of wound edges
Delayed primary closure - Closure within 3-5 days of wounding, before granulation tissue is visible in the wound bed
Secondary closure- Closure 5 or more days after wounding, once a healthy granulation bed is developing over the wound surface
Second intention healing - Wound heals by contraction and epithelialization, without surgical closure
