Ch 101 Larynx Flashcards

Question

What are the options for a patient with laryngeal collapse who does not respond to surgical management of BOAS and medical management? | 3

Answer 1

- Permanent tracheostomy - Laryngeal tieback - Epiglottectomy and Ablation of Unilateral Arytenoid Cartilage

Answer 2

In a study of 15 brachycephalic dogs with severe laryngeal collapse receiving permanent tracheostomy, there was a high risk of severe complications and postoperative death; however, a long-term (>5 years) good quality of life was reported in 5 of those dogs. **Gobbetti 2018**: Long-term outcome of permanent tracheostomy in 15 dogs with severe laryngeal collapse secondary to brachycephalic airway obstructive syndrome. Veterinary Surgery. - median survival time was 100 days. Major complications were diagnosed in 12 of 15 (80%) dogs, resulting in death in 8 (median survival time 15 days) and revision surgery in 4 dogs - long-term survival (exceeding 5 years) with a good quality of life was documented in 5 of 15 dogs.

Answer 3

- technique should be used with caution because the opposite cartilage may continue to collapse medially postoperatively leading to progressive airway obstruction. - 12 dogs with stage II or stage III collapse with continued airway obstruction after primary sx, a left unilateral combined cricoarytenoid and thyroarytenoid lateralization - Ten of the dogs survived to discharge and were alive and well at the time of follow-up (median, 3.5 years) - Consider Tokunaga 2020 where abnormal cartilage may be reason why tie-back may fail in brachycephalics

Answer 4

aim of increasing the air passage through the larynx, decreasing negative intraglottic pressure, and reducing airway resistance. Collivignarelli 2022: Subtotal Epiglottectomy and Ablation of Unilateral Arytenoid Cartilage as Surgical Treatments for Grade III Laryngeal Collapse in Dogs. Animals - One year after surgery, the owners of 12 patients rated their dogs as follows: excellent in five cases, good in five cases, and fair in two cases. - epiglottectomy associated with the photoablation of unilateral arytenoid cartilage increases airway flow, and thus may be considered a valid surgical procedure to treat dogs affected by grade III laryngeal collapse.

Answer 5

- - vagus nerve (originates from caudal nucleus ambiguus in the medulla) and its branches (recurrent laryngeal nerves) provide motor function to laryngeal muscles. - recurrent laryngeal > caudal laryngeal > cricoarytenoideus dorsalis contraction and abduction of arytenoid during inspiration. - - dogs and cats, unilateral or bilateral and congenital or acquired. Male dogs are approximately two to three times more affected than female dogs

Answer 6

Nucleus ambiguus Vagus nerve or its branches Cricoarytenoideus dorsalis muscle

Answer 7

Congenital trauma surgical trauma (v-slot, cranial thoracic sx, thyroidectomy) cervival/thoracic neoplasia neuromuscular disease (GOLPP, endocrine, myasthenia gravis, polyneuro)

Answer 8

Progressive degeneration of neurons within the nucleus ambiguus and Wallerian degeneration of laryngeal nerves - Bouvier des Flandres, Bull terriers, dalmations, Rottweilers, Leonberger - onset of clinical signs > usually before 1 year of age

Answer 9

Lab and Golder Retrievers St Bernards Irish Setters

Answer 10

possible causes - chronic endocrine (hypothyroidism – atrophy type II twitch fibres) > concurrently in 30%, although a direct causal link has not been established - infectious, or immune-mediated polyneuropathy, - surgical or traumatic damage to the vagus or recurrent laryngeal nerve, - lead or organophosphate toxicity, - retropharyngeal infection, - polyradiculoneuritis, - cranial mediastinal mass GOLPP (stanley 2010) - In many dogs the cause remains undetermined and traditionally classified as idiopathic; - recently been shown that many dogs with acquired laryngeal paralysis develop systemic neurologic signs within 1 year following diagnosis which is consistent with a progressive generalized neuropathy - Abnormalities of electrodiagnostic tests and histopathology of nerve and muscle biopsy reflecting generalized polyneuropathy

Answer 11

- - reported in cats (median age, 10 to 16 years) - - Cats >bilateral thyroidectomy, PDA ligation, cervical bite wounds, and head trauma

Answer 12

- acute is usually secondary to exacerbation of chronic disease (heat stroke) - change in voice, gagging + coughing - Progression slow, months-years > exercise intolerance + laryngeal stridor is noted during inspiration > develops severe respiratory distress. - accompanied by dysphagia and megaesophagus which significantly enhance the probability of aspiration after surgical correction of laryngeal paralysis - - unilateral laryngeal paralysis are usually asymptomatic unless they are exercising heavily. - Cats > tachypnea or dyspnea most common, dysphonia, inspiratory stridor - - Because cats and dogs with acquired laryngeal paralysis are old, concurrent disease is common - - polyneuropathy > muscle atrophy or peripheral neurologic abnormalities (decreased postural reactions, spinal reflex deficits, and cranial nerve abnormalities) lab - - heatstroke > coagulation panels and immediate evaluation of packed cell volume, glucose, and electrolytes + supportive treatment. Heatstroke can progress to DIC, multiorgan failure, and death - myasthenia gravis is suspected, acetylcholine receptor antibody titers are measured (association not clear)

Answer 13

Aspiration pneumonia 7.9% Oesophageal dysfunction 11.4% - assoc with an increased risk of post-op complications

Answer 14

- - rule out other causes of dyspnea, detect underlying etiologies (cranial mediastinal masses); and search for concurrent pathology such as aspiration pneumonia, noncardiogenic pulmonary edema, megaesophagus. - - In cats > hyperinflation of the lungs; caudal displacement of the larynx; and air in the pharynx, larynx, esophagus, and stomach - - Dogs that developed aspiration pneumonia also had worse esophageal function Stanley 2010

Answer 15

- Aspiration pneumonia >7.9% of dogs with laryngeal paralysis.82 If present, surgical intervention should be delayed until the aspiration pneumonia is resolved because it increases the risk of postoperative complications

Answer 16

1. direct visualization of the larynx with a simple laryngoscope, 2. oral video-endoscopic laryngoscopy, 3. transnasal laryngoscopy (TNL), 4. ultrasonography (echolaryngography), 5. computed tomography (CT).

Answer 17

- failure to abduct the arytenoid cartilages and collapse into the rima glottis on presumed inspiration, stenosis of the laryngeal inlet,and air-filled lateral ventricles.19 - Regardless of method, false-positive results are common because of the influence of anesthetic agents on laryngeal function. Ultrasound, Transnasal Laryngoscopy, and CT avoid the need for heavy sedation and general anesthesia; however, methods not shown to be superior to traditional oral laryngeal examination for definitive diagnosis

Answer 18

- A videoendoscope is useful for examination because it is less likely to require ventral epiglottic retraction - The animal should be anesthetized to the point at which the mouth can be easily opened but a laryngeal reflex is still present. - - Edema and erythema of the arytenoid cartilage mucosa are usually present on the dorsal part of the larynx dx - lack of arytenoid abduction during inspiration. - confounded by paradoxic movement of the arytenoids, resulting in a false-negative result. - The arytenoid cartilages move inward during inspiration because of negative intraglottic pressure created by increased respiratory effort against an obstruction

Answer 19

propofol - significant respiratory depression often occurs, with apnea related to dose, speed of injection, and use of concurrent premedications. ketamine - shown to preserve laryngeal function better in people, a study in dogs found no benefit for laryngeal examination when combining propofol and ketamine; Alfaxalone - Although causes respiratory depression, apnea has been shown to be less likely compared with propofol.23 propofol versus alfaxalone vs premeds - propofol or alfaxan induction for laryngeal examination in healthy dogs, the addition of premedications (acepromazine and butorphanol) improved the quality of the laryngeal examination regardless of the induction agent. This study did not recommend the use of propofol or alfaxalone alone - in contrast, alfaxalone alone resulted in the best respiratory function and quality of examination compared with propofol alone and alfaxalone or propofol used with premedications. - Another study, established that alfaxalone impacted laryngeal motion significantly more than propofol

Answer 20

- increase respiratory rate and effort and improve intrinsic laryngeal motion (central nervous stimulant) and may improve the ability to determine normal versus abnormal function, - results are mixed in studies regarding these benefits

Answer 21

improving ventilation, reducing laryngeal edema, and minimizing stress. treatment - oxygen supplementation, - short-acting steroids (dex 0.1–1 mg/kg IV) - sedatives (eg, ace0.02 mg/kg IV or butorphanol 0.2 mg/kg IV), - appropriate cooling procedures to redcue temp 38.9 temporary tracheostomy - negative prognostic indicator following definitive surgery >were more likely to experience major complications - Tube requires intensive monitoring to avoid life-threatening complications. - Complications: 86% of cases Translaryngeal percutaneous arytenoid lateralization - alternative to temporary tracheostomy - a mattress suture is placed through 1 arytenoid cartilage via an oral approach and exited through the skin ventral to the jugular Further studies are needed to determine the clinical utility of this method. Hardie 2016

Answer 22

- dogs with unilateral laryngeal dysfunction are typically not surgical candidates. - bilateral > decision to recommend surgery is based on the quality of life of the dog, severity of clinical signs, and time of year. - conservative management: environmental changes, reduction of daily exercise, owner education, weight loss - medical treatment is insufficient for long-term management.

Answer 23

- Clinical presentation is similar to that in dogs in that it occurs most often in middleaged to older cats (mean, 9–14 years), and both unilateral and bilateral conditions have been documented. - - Unlike dogs, cats with unilateral dysfunction can have significant clinical signs and require surgical intervention. - cause often remains undetermined > trauma, neoplastic invasion, and iatrogenic damage assessment: - alfaxalone has been evaluated compared with propofol and midazolam/ketamine, All 3 protocols provided similar conditions to evaluate laryngeal motion Conservative management: weight loss and minimization of excitement and rigorous exercise. Surgical: - successful unilateral arytenoid lateralization has been described in several small studies. - Complications are noted in 50% to 54% of cats after unilateral or bilateral arytenoid lateralization - aspiration pneumonia (15%), postoperative dyspnea requiring temporary tracheostomy, increased inspiratory noise, Horner’s syndrome, pulmonary edema, and laryngeal stenosis - Few studies of long-term results are available. In one study, the mean and median survival times of 10 cats 406 and 150 days

Answer 24

Unilateral or bilateral arytenoid lateralisation Ventricular cordectomy and partial arytenoidectomy Modified castellated laryngofissure Permanent tracheostomy stent

Answer 25

- very consistent outcome - - Bilateral seems to be associated with more complications than unilateral, and the latter technique is sufficient to resolve clinical signs - - Several variations of unilateral arytenoid lateralization have been described. The most common technique involves suturing the cricoid cartilage to the muscular process of the arytenoid cartilage, which mimics the directional pull of the cricoarytenoideus dorsalis muscle and rotates the arytenoid cartilage laterally. - the thyropharyngeus muscle is transected. - Some clinicians separate the cricothyroid junction; however, this is not usually necessary and may destabilize the larynx, decreasing the glottic diameter - nonabsorbable suture (2-0 polypropylene on a taper needle in dogs; 3-0 in cats) - Some surgeons pass two sutures before tying.74 If cartilage is calcified or friable, holes for needle passage can be predrilled with 18 gauge hypodermic needles - the final glottic opening will be no larger than that of the animal with the endotracheal tube in place. Assistant can observe per os

Answer 26

with or without cricoarytenoid lateralization has also been described. The purpose of the thyroarytenoid suture is to achieve lateral displacement of the arytenoid without caudal displacement. - one study of clinical cases, the rima glottidis area was significantly greater after cricoarytenoid lateralization (207%) than thyroarytenoid lateralization (140%); however, there was no difference clinically in dogs treated with either technique - Drudi 2022

Answer 27

Cricoarytenoid - 207% Thyroarytenoid - 140%

Answer 28

- increasing the surface area of the rima glottidis beyond the edges of the epiglottis could put the animal at higher risk of aspiration. - According to Poiseuille’s law, resistance to flow is inversely related to the radius to the fourth power. Because of this, a small increase in glottic area dramatically reduces airway resistance and improves airflow - Limited lateral displacement of the arytenoid might decrease the risk of postoperative aspiration pneumonia. - Experimental cadaver study: recommend sutures be tied without overabduction and caudodorsal displacement > primary functions are to keep the arytenoid in a normal position at rest

Answer 29

- - A recent surgical description >less invasive approach to include less than 25% transection in length of the thyropharyngeus muscle and preservation of the cricopharyngeus muscle, cricothyroid articulation, and sesamoid bands Von Pfeil 2014 - - However, in a separate study, there was no significant difference in risk of aspiration pneumonia or survival times between a standard technique and one that preserves laryngeal anatomy Perez Lopez 2019

Answer 30

- **Improvement is expected in 90%** of animals undergoing unilateral arytenoid lateralization, and **70% of dogs are still alive 5 years** after surgery - quality of life 6 months after surgery was thought to be improved by 93% of owners of large dogs and 55% of owners of small dogs

Answer 31

**10% to 58% of dogs (7-23% perez lopez 2019)** - seroma, - intramural hematoma, - aspiration pneumonia (**8% to 21%** of dogs, days to years after unilateral arytenoid lateralization ) - persistent coughing or gagging, - persistent or recurrent signs (up to **33%** ) - residual stridor on auscultation, - surgical failure from suture breakage or arytenoid cartilage fragmentation, - laryngeal webbing - progression of generalized neurologic signs

Answer 32

- depend on the type of surgery performed - one study, the complication rate 89%, with 8 of 9 dogs developing aspiration pneumonia or respiratory distress - study of 67 dogs with bilateral and vocal fold excision, major complication 12% and minor 33%. long-term follow-up, 3 of 40 dogs developed aspiration, and 6 of 40 dogs had recurrence of clinical signs that required additional surgery

Answer 33

- various techniques for vocal cord excision and partial arytenoidectomy (only corniculate process) to increase the diameter of the glottis > transoral, ventral approaches, laser - Unilateral usually adequate (and reduce aspiration) - High complication rates have been reported by some investigators; however, bilateral vocal fold resection alone resulted in fewer complications and better postoperative outcome than other partial laryngectomy techniques - Electrocautery is avoided because of the risk of postoperative swelling and granulation tissue formation.101 - Bilateral ventriculocordectomy > reasonable longterm (>6 months) outcome with a low incidence of major complication (7%) - a direct comparison of outcomes between dogs treated with either unilateral arytenoid lateralization or bilateral ventriculocordectomy found that dogs undergoing bilateral ventriculocordectomy were more likely to have chronic (lifelong) respiratory complications - - a small cadaveric study of canine larynges, bilateral ventriculocordectomy did not seem to reduce laryngeal airway resistance

Answer 34

Outcome - In general, the outcome is good - Satisfactory in 86% and in the long term in 90% - Complications: 40-50% > laryngeal webbing, scarring + aspiration pneumonia (6-33%). - 25 dogs that underwent bilateral ventriculectomy via oral approach, 48% of dogs had long-term complications, primarily respiratory distress from cicatrix formation

Answer 35

- Offset closure of a stepped, or castellated, incision of the thyroid cartilage results in enlargement of the ventral laryngeal ostium. Use for treatment of laryngeal paralysis is rare because of the difficulty of the procedure and the lack of additional benefits to the patient compared with other techniques - opens the rima glottidis as much as a bilateral arytenoid lateralization but does not reduce postoperative airway resistance to the same degree - severe postoperative laryngeal bleeding and edema that may require a temporary tracheostomy tube for 2 to 3 days

Answer 36

- is considered a salvage procedure for dogs most at risk of aspiration pneumonia (myopathy, megaesophagus, hiatal hernia etc) - associated with a high rate of major and minor complications and requires diligent postoperative and long-term care. - 21 dogs with permanent tracheostomies: 50% major complications 20% required revision surgery 26% acutely died at home, most likely from airway obstruction

Answer 37

- In the absence of surgical complications, unilateral arytenoid lateralization results in reduced respiratory distress and stridor and improved exercise tolerance. Owner satisfaction with this procedure is excellent, with most owners believing that the quality of the dog’s life was improved dramatically. - One-year 93% + 4 yr 75% (83% and 25% if aspiration post-op) Aspiration pneumonia - most common 10% to 21% (arytenoid lateralization) - most likely in the first few weeks following surgery - at risk for the rest of their lives - megaesophagus and post-op opioid = significant risk factors for development of aspiration pneumonia. gastrointestinal motility modifiers - Metoclopramide increases lower esophageal sphincter (LES) tone - prospective multicenter clinical trial >perioperative administration of metoclopramide did not affect the incidence of aspiration pneumonia in the short-term post-op postoperative period - A retrospective evaluation of a cisapride infusion suggested a positive effect on postoperative aspiration pneumonia, but definitive conclusions not drawn because of low numbers in the study

Answer 38

* preoperative aspiration pneumonia * oesophageal dysfunction * progression of generalized neurologic signs Stanley 2010 * temporary tracheostomy placement * concurrent neoplastic disease.

Answer 39

- use of laryngeal silicone stents to treat canine laryngeal paralysis in dogs - Results - Six dogs > showed improvement in clinical signs immediately after the procedure. - One dog was suspected of aspirating water while drinking, but the signs disappeared after repositioning the stent. - One dog relapse of stridor due to caudal migration of the stent. This dog underwent arytenoid lateralization surgery because larger stents are not commercially available. - between 7-13 month, four dogs owners report a satisfactory quality of life. - Conclusions - alternative for treating dogs with acquired laryngeal paralysis - stent placement can be a temporary solution to stabilize these dogs until a permanent surgical treatment can be performed. Théron 2022:

Answer 40

- normal dog, epiglottic tip rests on the dorsal surface of the soft palate - hyoepiglotticus muscle (innervated by the hypoglossal nerve) - draws the epiglottis downward >bkeeping the nasopharyngeal airway patent. pathophys - Muscle laxity + combined with extreme inspiratory effort, may result in retroversion of the epiglottis into the laryngeal ostium and subsequent airway obstruction. Dx - Epiglottic entrapment > coughing, gagging, dyspnea, and collapse - detected on inspiratory cervical fluoroscopy and confirmed on laryngoscopy. Treatment: - epiglottopexy (temporary or permanent) or partial/subtotal epiglottectomy - Epligottopexy failure is reportedly common - Pexy post-op complications 54% vs ectomy 25%, intra-op complications uncommon - Good long term survival (median >700d) MULLINS 2019

Answer 41

- cause of dyspnea and wheezing in cats.112 - diagnosis > ultrasound + histologic analysis - Treatment > surgical excision. completely excised. No recurrence was noted

Answer 42

Cats - partial airway obstruction from lymphoplasmacytic inflammation and lymphoid hyperplasia of the laryngeal mucosa over the arytenoids or vocal folds.21,66 - cause unknown - On laryngoscopy, laryngeal inflammation may appear as a discrete mass or diffuse vocal fold thickening - biopsy samples to differentiate from lymhoma - Treatment: glucocorticoids and antibiotics. - Temporary tracheostomy is often required until inflammation resolves - Prognosis is considered poor for cats that are presented with severe clinical signs. Granulomatous laryngitis (dogs) - Brachycephalic dogs - vocal folds concurrent with other conditions of BOAS. - recurred after resection with a CO2 laser/topical treatment with mitomycin or corticosteroids - Surgical resection may therefore require ventral laryngotomy, vocal fold removal, and primary mucosal closure. - Antacid therapy may be beneficial in some animals

Answer 43

- Causes: bite wounds, choke collars, foreign bodies, gunshot wounds, and traumatic or long-term intubation. - Dyspnea and exercise intolerance > acutely (swelling or cartilage displacement) or develop over time dt stenosis - Diagnosis> examination, laryngoscopy, radiography, and computed tomography Treatment - Conservative if minimal displacement may require partial arytenoidectomy or tie-back traumatic wounds > intubation or tracheostomy tube placement, wound exploration, debridement, drainage or managed open. - evaluated for secondary laryngeal paralysis or stenosis - stents has been reported - Fractures of the laryngeal cartilages may result in acute or insidious onset of clinical signs. - Iatrogenic cuneiform process fracture, hit by a car cricoid cartilage fracture (Dx on CT)

Answer 44

- Stenosis secondary to laryngeal web formation - causes included oral ventriculocordectomy (10 of 15 dogs), arytenoid lateralization, unilateral arytenoidectomy, and bilateral laryngeal sacculectomy - Clinical signs developed 1 to 4 months after sx - Treatment > transoral laser or blade excision or bougienage of scar tissue was unsuccessful Tube tracheostomy was required perioperatively in 5 dogs. ventral laryngotomy for web transection/resection and primary mucosal closure One dog required permanent tracheostomy. All dogs survived the immediate postoperative period, and 6 of 9 dogs were free of clinical signs at long-term follow-up (mean, 2.7 years)

Answer 45

- When commercially available tubes are not available, an endotracheal tube can be trimmed to an appropriate size - - multiple variations in tracheal incisions and flaps - None has been shown to be particularly advantageous - Successful use of silicone tracheal stoma stents was in 18 dogs - - either between two tracheal rings in a horizontal (transverse) manner or through 2-3 rings in a vertical (longitudinal) manner. - The length of the transverse > not exceed half the circumference of the trachea - stay sutures are placed - An appropriate tube > outer diameter of the tracheostomy tube not exceed 75% of tracheal diameter - tube size should be large enough to provide flow through the tube but small enough to allow ample room for airflow around the tube. This helps to prevent silent death from occlusion of the tube lumen - intensive management and 24-hour observation of the patient are essential >a nurse should be designated

Answer 46

- The cuff should not be inflated - Cuffed result in a significant increase in airway pressure compared to uncuffed tubes. - tracheostomy results in inspiration of cool, dry air (bypasses the upper airway,) - Tracheobronchial tree responds > increasing mucus > collects around and within the tube and stoma. - single-lumen tubes must be removed and replaced every time - double-lumen tubes have a removable cannula that can simply be exchanged. - tubes should be replaced twice daily; exchange can be required as frequently as every 4 to 6 hours - cleaned and soaked in 2% chlorhexidine and rinsed with sterile saline before replacement. - Airway suctioning is another means used to keep the tube patent and is performed as frequently as necessary - no more than 10 to 12 seconds > Uninterrupted suction can lead to severe atelectasis and hypoxia. A vagal response may also be elicited, resulting in gagging, retching, or bradycardia - adequate humidification of the airway saline or nebulization The decision to remove the tube - typically coincides with resolution of the inciting event - prudent to occlude the tube and stoma with an occlusive dressing for 15 to 20 minutes under direct observation to ensure that respiratory distress does not ensue. - Tracheostomy wounds heal by second intention within 7 to 10 days

Answer 47

Acute complications - 50% - plugging with debris, inadvertent tube removal, gagging, coughing, vomiting, subcutaneous emphysema, pneumothorax, infection, and respiratory distress - plugging of the tube 18% to 25% of cases. - Cats > higher risk of occlusion because of greater mucus production. 87% had complications. However, 91% of cats with benign disease were discharged long-term complication - stenosis. - Two areas > at the stoma site itself and at the level of the cuff or tube tip - The advent of high-volume, low-pressure cuffs has reduced the incidence - documented in dogs > average loss of 18% to 24.7% of luminal area has been noted, regardless of the type of tracheostomy created. Overall - complications as high as 86% in dogs – 81% management but only 60% dogs survived discharge. - The outcome for cats is more guarded, with only 43% of cats being discharged from the hospital in one study

Answer 48

Surgery technique - The sternohyoideus muscles can be apposed dorsally to the trachea using mattress sutures to help elevate the trachea - The ventral half of the cartilage of **3 or 4 tracheal rings** is removed with a #11 blade - simple interrupted or continuous pattern of fine (3-0 or 4-0) absorbable suture material is used to appose the mucosa to the skin. - Dahm and Paniello documented significantly higher mortality rates (57%) when the stoma was **placed below the 12th tracheal ring** - skin fold occlusion is a prime concern > excise excessive skin Management - Care = temporary tube tracheostomies - cleaning, humidification, and suctioning every 4 to 6 hours - skin surrounding the site is protected from secretions by applying a thin layer of antibiotic ointment - healing occurs typically over 2 weeks - undergoes squamous metaplasia > excessive mucus production can result in obstruction - should be cleaned frequently - Typically, secretions are minimal 1 month after surgery.

Answer 49

Dehiscence change in phonation aspiration pneumonia need for revision death (obstruction) stenosis tracheal collapse - Immediate similar to tube tracheostomy - most common: aspiration pneumonia and the need for revision surgery - study of 21 cats > mucus plugs > death by asphyxiation in 5 cats. - median survival times for cats 20.5 - 42 days. - major complications in 10 of 20 dogs 4 dogs requiring revision of the stoma site. - median survival time 328 days. - Acute death following discharge > 26% and presumed to be the result of airway obstruction. Stenosis - less than 10% significant - Hedlund et al, all animals affected to some degree - tracheal collapse may occur if the stoma is too large - preexisting collapse > reinforced with extraluminal polypropylene rings. - The tracheal mucosa undergoes squamous metaplasia > inflammatory infiltrates 0 - 4 weeks - - more normal by 16 weeks environmental modifications - necessary for a successful outcome: - healthy weight to ease exercise and reduce excess folds, - keep the hair clipped around the stoma - no swimming.

Answer 50

Two dogs in each treatment group developed moderate to severe cervical esophageal paresis. This did not occur in control dogs. no evidence to support our hypothesis that muscle-sparing laryngoplasty results in less severe changes in swallowing function compared to a standard technique

Answer 51

Results indicated that head posture significantly affected the laryngopharyngeal structures in dogs. Fluoroscopic examination of the upper respiratory tract of a dog should be performed with an NHP to minimize posture-induced changes in measurements

Answer 52

Left cricoarytenoid abduction (lateralisation) was performed in 20 ex vivo cat larynges; 10 following complete cricoarytenoid disarticulation (group LAA-dis) and 10 following no cricoarytenoid disarticulation The mean percentage increase in LAA - 311.5% (complete disarticulation) - 199.4% no cricoarytenoid disarticulation - no evidence of a lack of epiglottic coverage of the entrance of the larynx for any of the postoperative larynges. The clinical significance of the difference in outcome between left cricoarytenoid abduction following complete cricoarytenoid disarticulation and abduction following no cricoarytenoid disarticulation remains unclear, and both might be considered appropriate for the surgical management of laryngeal paralysis in the cat.

Answer 53

retrospective multicentre study Debulking surgery was performed in 26% of cases. All cats received chemotherapy 35% had a partial response and 65% a complete response Median PFS and OS were 909 days (range 23–1484) and 909 days (range 23–2423), respectively. B-cell phenotype, could be of a low-to-medium grade, and may respond to surgical and medical treatment with a longer survival time than has previously been reporte

Answer 54

Bilateral laryngeal paralysis was identified in three dogs and unilateral laryngeal paralysis in two dogs via endoscopic assessment of laryngeal function. The primary concomitant lesions included tracheal injury in 3/5 dogs and oesophageal injury in 1/5 dogs. Clinicians should be aware of this pathology and the importance of investigating laryngeal function in dogs presenting with cervical bites, particularly those with inspiratory dyspnoea

Answer 55

44 client-owned dogs. PROCEDURES Medical records were retrospectively reviewed The overall complication rate was 22.7% (10/44), with 35% (7/20) being in the inpatient group and 12.5% (3/24) being in the outpatient group. The overall mortality rate was 6.8% (3/44). outpatient management of dogs with laryngeal paralysis treated with elective unilateral arytenoid lateralization is an appropriate method of postoperative management with no difference in complication or mortality rates. Further prospective studies with standardized surgical, sedative, and antiemetic protocols are warranted to evaluate more definitely. Another multicenter randomized clinical trial found no significant differences in the rate of development of aspiration pneumonia when a metoclopramide constant rate infusion was used.16 Given the minimal effects that prokinetic therapy had on the incidence of aspiration pneumonia, patients without a history of frequent regurgitation or vomiting likely wouldn’t benefit from hospitalization. Instead, it is possible that hospitalization may cause anxiety and distress, did any almost die before disharge?

Answer 56

cricotracheostomy technique for permanent tracheostomy 8 dogs The stomata did not show any evidence of dorsal wall collapse or stenosis. 4 > required further skin fold resection. Comparative clinical investigation with traditional is indicated The high position > very functional, easy to maintain and may even be less prone to obstruction than the traditional The importance of bilateral cervical skin fold resections cannot be overemphasized brachycephalic breeds, with tracheal hypoplasia, may be at higher risk of obstruction?

Answer 57

novel transoral endoscopic arytenopexy in canine cadavers rima glottis area (RGA) and laryngeal epiglottic-glottic seal (LEGS) suturing the lateral aspect of the left arytenoid soft tissues to adjacent pharyngeal wall across the piriform recess. The LEGS remained intact. The mean percent change in RGA 157.00% ideal increase in RGA to decreased resistance without increasing risk of aspiration unknown literature has shifted practice away from dramatically increase the RGA > lessen the risk of aspiration through better preservation of the LEGS Hagen-Poiseuille> airway resistance is inversely proportional to the airway radius to the fourth power.

Answer 58

prospective, 14, Comparison and thyroarytenoid lateralization thyroarytenoid rima glottidis area 152% at t0 and 127% at t1 cricoarytenoid 205% at t0 and 199% at t1 Cricoarytenoid lateralization and TAL were both effective short-term reduction in area occurred in the TAL > no associated clinical signs. CAL resulted in a larger increase > provided no short- or medium-term advantage over TAL CAL may increase the risk of aspiration pneumonia because the epiglottis does not cover the entire rima glottidis.

Answer 59

In all cats, a full-thickness portion of one or several laryngeal cartilages was resected, including thyroid cartilage alone (n = 2), thyroid cartilage and arytenoid (n = 2), and arytenoid cartilage and epiglottis (n = 2). Four cats showed varying degrees of respiratory distress in the short-term postoperative period. A temporary tracheostomy tube was placed in two cats. No other postoperative complications were noted in the short or long term. Four cats were still alive at the time of writing. These cats survived at least 252 days.

Answer 60

Study Design: Experimental study. Animals: Six healthy adult dogs. An intermittent tachycardic effect of up to 79% increase in HR was observed with doxapram. However, anesthetic drugs such as propofol decrease laryngeal motion,4 and this introduces a confounding factor to the examination, potentially creating a false positive diagnosis for laryngeal paralysis All treatments were effective respiratory stimulants in anesthetized dogs; however, doxapram caused hypertension and tachycardia Neither hypertension nor tachycardia was observed with I-CO2 The combination of acepromazine and dexmedetomidine as a sedative combined with propofol has not been previously evaluated; however, our results align with the previous findings that some dogs had absent or insufficient arytenoid motion prior to each respiratory stimulation Respiratory stimulants, such as doxapram and carbon dioxide, improve the quality of the laryngoscopy5,6; however, they can cause adverse cardiovascular effects.7

Answer 61

lesions were exclusively unilateral, exophytic, approximately 3-mm wide ulcerated mucosal nodules, arising from the vocal cord. Histopathological examination mainly revealed chronic inflammatory changes In brachycephalic breeds, chronic inspiratory efforts and air turbulences and gastro-esophageal reflux are suspected to result in chronic laryngeal inflammation. All dogs were assigned a respiratory clinical score of 1 which corresponds to a marked clinical improvement. No dog required additional surgical or medical treatment. one had local recurrence on EUS

Answer 62

Randomized, crossover, blinded study. Animals: Eight adult research hounds weighing 8 to 22.5 kg. Dogs were sedated with propofol, dexmedetomidine, dexmedetomidine and butorphanol, or dexmedetomidine and hydromorphone propofol, which resulted in two false positive results Postdoxapram GGAn was greater than predoxapram GGAn for all four sedation protocol Dexmedetomidine sedation does not inhibit normal laryngeal motion. Laryngeal examination with propofol alone can produce false positive results Dexmedetomidine is reversible, can be titrated to the desired level of sedation, does not cause significant respiratory depression, and allows opening of the mouth and exteriorization of the tongue Future studies examining the use of dexmedetomidine for laryngeal function examinations in dogs with confirmed laryngeal paralysis are warranted Twenty-three of 24 examinations performed with dexmedetomidine protocols resulted in a “pin and pant” phenomenon after doxapram administration. > assume maximum abduction indicated laryngeal function

Answer 63

serotonin 5-HT4 receptor agonist, cisapride One of 50 dogs in the cisapride group and six of 52 dogs in the historical group developed aspiration pneumonia within the immediate postoperative period Preoperative treatment with a cisapride CRI does not appear to dramatically influence the rate of postoperative aspiration pneumonia but further stud ies are needed.. study supports the use of butorphanol with acepromazine in the preoperative period and buprenorphine for postoperative analgesia, because these therapies appeared associ ated with lower rates of aspiration pneumonia

Answer 64

Conclusions In this study, there was no significant difference in risk of aspiration pneumonia or survival time following arytenoid lateralisation by either an ST or an APT.

Ch 101 Larynx Flashcards

(96 cards)