Palate Flashcards
According to Fenner 2020 in Vet Surg, what were 2 risk factors associated with post-operative regurgitation following BOAS surgery?
History of regurgitation and age (for every 1 year increase in age the odds of experiencing post-op regurgitation were reduced by 28.8%)
According to Franklin 2021 in Vet Surg, what was the effect of epinephrine nebulization in BOAS patients pre- and post-operatively?
Reduction in BOAS index, particularly in patients with a pre-operative BOAS index >70%.
In a study by Fracka 2024 in Vet Surg, what were 4 risk factors identified for complicated perioperative recovery in dog undergoing either staphylectomy or folded flap palatoplasty?
Increasing age, staphylectomy (rather than FFP), increased anesthesia length, laryngeal collapse grade >2
In a study by Jones 2024 in Vet Surg, what 2 factors were associated with an increased risk of mortality in dogs undergoing staphylectomy with a variety of devices?
Use of a bipolar vessel sealing device (as compared to incisional or CO2 laser), higher grade of laryngeal collapse.
In a study by Miller 2024 in Vet Surg, what was the difference in complications between folded flap palatoplasty and staphylectomy for treatment of BOAS?
No difference in complications. Folded flap had a longer anesthetic and operative times.
The addition of what to a maxillary nerve block resulted in less hemorrhage during staphylectomy in a study by Williams 2024 in Vet Surg?
Adrenaline added to lidocaine
In a study by Carabolana 2022 in JAVMA, what was the overall mortality rate following H-pharyngoplasty and ala-vestibuloplasty for BOAS? What was associated with an increased risk of death? What percentage of dogs had an improvement in respiratory and digestive signs?
2% mortality
Age was associated with an increased risk of death (30% increase for every year of age).
Improvements were seen in respiratory signs for 72% of dogs, and digestive signs for 34%.
What technique was described by Pavletic 2023 in JAVMA for closure of wide palatal defects in dogs?
Modified Lagenbeck technique using bilateral bipedicle mucoperiosteal flaps.
In a study by Castejon-Gonzalez 2024 in JAVMA, what was used to augment palatal closure in dogs with wide clefts?
Autologous auricular cartilage from the pinna or allogenous fascia (used in conjunction with the Lagenbeck or 2-flap palatoplasty technique)
In a study by Holloway 2022 in JSAP, what was the overall complication rate in patients undergoing split staphylectomy? What is the proposed benefit of this procedure?
8% complication rate (3% major, and none life threatening).
Proposed benefit of this technique is the ability to address both excessive palatal length and thickness.
What surgical technique is depicted, which can be used for the temporary management of dogs with BOAS in respiratory distress as described by Sun 2022 in JSAP?
Temporary palatopexy procedure
In a study by Filipas 2024 in JSAP, what were 4 post-operative respiratory complications seen in BOAS dogs undergoing surgical correction? What increased the risk of requiring post-operative tracheostomy?
The four most common post-operative respiratory complications were hypoxemia, dyspnea requiring tracheal reintubation or tracheostomy, and aspiration pneumonia.
Risk factors for tracheostomy were increasing BOAS grade and peri-operative aspiration pneumonia.
In a study by Camarasa 2023 in JSAP, what was the difference in post-operative complications in BOAS patients undergoing owner assisted or standard recovery?
Owner assisted had a complication rate of 2%, compared to standard which had a complication rate of 28%.
In a study by Gilman 2023 in JSAP, use of a harmonic scalpel for staphylectomy resulted in reductions in what two factors compared to traditional staphylectomy in dogs?
Hemorrhage and surgical time.
There was an average of 0.68mm of thermal necrosis.
In a study by Tarricone 2019 in Vet Surg, how much more likely were dogs undergoing BOAS surgery t have a negative outcome with a BRisk score >3?
9 times as likely.
What bones comprise the hard palate?
Incisive, maxillary, palatine. Covered with mucoperiosteum.
At what level are the major palatine foramina located?
Medial to the maxillary fourth premolar tooth.
What is the main blood supply to the hard and soft palate?
The major and minor palatine arteries (branches of the maxillary artery).
What is the innervation to the hard and soft palate?
Major and minor palatine nerves (branches of the maxillary division of the trigeminal nerve). Travel in conjunction with the major and minor palatine arteries.
What is the innervation to the pterygopharyngeus and palatopharyngeus muscles?
Vagus and glossopharyngeal nerves.
What are the muscles of the soft palate?
Tensor and levator veli palatini, palatinus.
During swallowing the levator veli palatini muscle draws the soft palate dorsally to prevent aspiration. The palatopharyngeal also draws the palatopharyngeal arches and caudal pharynx together.
What are potential causes of congenital cleft palate formation?
Inherited or secondary to intrauterine stress or trauma.
Are unilateral cleft lips more commonly left or right sided?
Left sided
At what age is surgery of palatal defects typically performed?
2-4 months. Postponing surgery until after 5 months might result in a larger cleft.
Midline clefts of the hard palate are often seen in cats following what events?
Falling from a height or motor vehicle accident.
Often have bilateral epistaxis or dried blood at the nostrils, visible malalignment of the maxillary dental arch, and a midline hard palate defect.
What clinical sign is common with oronasal fistula following tooth removal?
Unilateral epistaxis.
How much larger should flaps be than the palatal defect they are going to repair?
1.5 x larger
If teeth are likely to impede palatal defect repair or traumatize tissue flaps, how long prior to the procedure should they be extracted?
6-8 weeks prior to definitive closure.
How are rostral palatal defects repaired?
Simple sliding procedures often unsuccessful due to the absence of a connective tissue bed to support the flaps. Repair generally achieved with advancement, rotation, transposition, or over-lapping flaps.
What are the surgical repair techniques for closure of midline hard palate defects?
- Overlapping flaps
- Medially positioned flap
- Rotational flap
What are the advantages of the overlapping flap over the medially positioned flap for palatal repair?
With the overlapping flap sutures are not directly over the defect and the area of opposing connecting tissues is larger.
Repair of large defects with the medially positioned flap might result in formation of lateral oronasal fistulas.
Overlapping flap has more reliable results than the medially positioned flap.
What surgical repair technique can be used for repair of midline soft palate defects?
Medially positioned flap technique.
Congenital hypoplasia of the soft palate can be treated using bilateral buccal mucosal flaps or creation of dorsal and ventral flaps after tonsillectomy.
What palatal repair technique is shown?
What palatal repair technique is shown?
What palatal repair technique is shown?
During creation of medially positioned and overlapping flaps for repair of midline hard palate defects, care should be taken to preserve what structure?
Major palatine artery.
What repair technique is typically used for repair of oronasal fistulae in the region of the canine tooth?
Labial based mucoperiosteal flap
What repair technique can be used for correction of large caudal hard palate defects?
Split palatal U-flap technique
What axial pattern flaps might be used for repair of large palatal defects?
Angularis oris, superficial temporal, caudal auricular, superficial cervical (omocervical).
Local axial pattern flaps using the major palatine and infraorbital arteries have also been described.
What is a palatal obturator?
A prosthesis designed to fill palatal defects. Can be made from a metal alloy, non-aqueous elastomeric impression material, or synthetic resin.
Should be removed and cleaned every 6-12 months.
What is a major complication after palate defect surgery?
Wound dehiscence
What percentage of airway resistance does the nose contribute in normal dogs?
80%
According to Poiseuille’s law, a reduction in airway diameter results in a reduction in airway flow proportional to what?
The radius of the airway to the power of 4.
What are some pathophysiologic changes associated with overlong soft palate as a part of BOAS?
- Longer contraction of the inspiratory muscles (vagal reflex) and expiration below the functional reserve to increase elastic energy in the chest for inspiration.
- Chronic hypoxemia, (+/- increased PaCO2) stimulating respiratory effort.
- Hyperthermia due to respiratory work.
- Fibrosis of the pharyngeal dilator muscles (thought to be secondary to bursts of dilator muscle activity during apnoeic episodes).
- Pharyngeal collapse.
- Non-cardiogenic pulmonary edema: inspiration against upper airway obstruction results in flux of fluid from the pulmonary capillaries to the interstitium.
- Moderate to severe gastrointestinal signs (may contribute to worsened respiratory signs). Include esophageal deviation, gastroesophageal reflux, hiatal hernia, esophagitis, pyloric mucosal hyperplasia.
What treatments should be instituted in a patient presenting in respiratory distress due to BOAS?
Oxygen, sedation (acepromazine), cooling, intravenous fluids, dexamethasone +/- emergency intubation or tracheostomy.
When treating BOAS what pre-medication should be administered to help prevent vagal discharge?
Atropine or glycopyrrolate.
What is the normal tracheal diameter at the thoracic inlet as measured as a percentage of the thoracic inlet?
20% (13% in bulldogs).
What is the level of resection suggested for resection of the soft palate?
Caudal border of the palatine tonsils. Caudal edge should slightly overlap the epiglottis.
What are surgical options for palatal resection in cases of overlong soft palate?
Staphylectomy (CO2 laser, cut and sew, bipolar vessel sealing device), folded flap palatoplasty, H-plasty.
What post-operative medications might be useful in the management of BOAS patients?
Dexamethasone, oxygen supplementation, withholding of food (24-48 hours), GI medications (pantoprazole, metoclopramide, famotidine).
What are some complications associated with soft palate resection?
Aspiration pneumonia, failure to recover, post-operative swelling, dyspnea, cyanosis, death.
Temporary tracheostomy may be required in some instances.
