Surgical conditions of the respiratory tract - SA 1&2 Flashcards
What divides the airway into URT and LRT?
junction between the cricoid cartilage and the trachea (larynx is therefore URT)
Why aren’t any surgical interventions of the airways considered D1Ss?
all have the potential to cause life-threatening inflammation or haemorrhage that can obstruct the airway
Name 3 conditions of the rhinarium
- congenital deformities (stenotic nares and cleft lip)
- lacerations/trauma
- neoplasia (SCC and MCT)
What raises your index of suspicion for SCC in rhinarium?
non-healing ulcers here
What are broad causes of nasal discharge? 6
- chronic hyperplastic rhinitis
- trauma
- dental disease
- intranasal neoplasia
- mycotic rhinitis
- FBs
Breed predisposition - chronic hyperplastic rhinitis
Whippets, Dachshunds and cats
Tx - severe and intractable chronic hyperplastic rhitinits
rhinotimy and turbinectomy
What should you do if a patient has trauma-induced nasal discharge? 4
- little need for orthopaedic fixation
- ensure maxillary fractures are reduced to maintain dental occlusion
- check later fro acquired palatine clefts
- occasionally as sequestrum may form so check radiographs for this and also osteomyelitis
Describe nasal discharge associated with dental disease
- mucopurulent, occasional epistaxis
- unilateral
- periapical lucency on radiography (occasionally these are incidental)
- lesions
What tumours are most common in the nose?
Most are malignant - solid carcinoma or adenocarcinoma, chrondo/fibro/osteo-sarcoma
What is a benign polypoid rhinitis?
very rare but clinically indistinguishable from nasal malignancies except histopath. Good prognosis following polyp removal
What causes mycotic rhinitis 2
Aspergillus and Penicillium
Define sinusotomy
surgical incision into a skull sinus
Treatment - mycotic rhinitis
If non-surgical treatment fails, surgical placement of irrigation tubes via sinusotomy may facilitate successful Enilconazole (imidazole fungicide) therapy
CS -FBs in nose
sudden onset sneezing. serous discharge, may progress to mucoid/purulent discharge if chronic
How common are nasal FBs?
not as common as many clients suspect!
How are defects in the secondary palate (hard and soft palate) characterised?
Congenital or acquried
Clinical signs - congenital defects of the secondary palate
- noticed early in life
- fail to thrive
- unable to suckle succesfully
- often have nasal return of milk
- aspiration pneumonia signs
- mild cases may only show chronic nasal discharge
Clinical signs - acquired defects of the secondary palate
- chronic nasal discharge and sneezing due to constant impaction of food material in nasal cavity*
- aspiration pneumonia
Treatment - secondary palate defects
surgical repair when CS present. often complicated
Define BAOD
Brachycephalic Airway Obstruction Syndrome
What is BAOD
a group of conditions commonly found amongst brachycephalic breeds. Abnormalities are often present at birth but clinical disease may not become a problem until middle age.
What are the primary and secondary BAOD pathologies?
PRIMARY - stenotic nares, long soft palate
SECONDARY - eversion of the lateral laryngeal ventricles, laryngeal collapse, others (tracheal hypoplasia, redundant pharyngeal mucosa, scrolling of the epiglottis)
CS - BAOD
MILD: execise intolerance or dyspnoea following stress or excitement, exacerbation by heat and stress
SEVER: loud noise on inspiration and expiration (steror) and visibly small external nares, poor heat dissipation (–> pyrexia) and vicious cycle develops
What is an acute obstructive crisis?
precipitated by heat or extreme stress in BAOD dogs, causes cyanosis and collapse
Diagnostic considerations BAOD
Rule out other causes fo inadequate ventilation/tissue perfusion
- PE - rule out CV and pulmonary disease (auscultation difficult because of referred URT noise)
- Haematology and serum biochemistry
- thoracic radiographs
- lateral radiograph of larynx
- pharyngeal and laryngeal exam
Treatment - BAOD
- early in day (full day supervision after)
- best to follow examination of URT with surgery if necessary rather than giving a second anaesthetic
- rhinoplasty
- staphylectomy
- resection of everted mucosa of lateral laryngeal ventricles
- temporary tracheostomy (optional)
Post-op care - BAOD treatmetn
- routine tracheostomy management (if used)
- intensive observation and care
- keep animal as quiet as possible for following 7-10 days
What is tracheal hypoplasia? Breed predisposition?
- narrowed trachea
- bulldogs
- generally can live a normal life providing upper airway is in good condition. occasionally very severely affects animals
Define tracheotomy
a temporary tracheostomy
Indications - tracheotomy (temporary tracheostomy)
- precaution prior to some upper airway surgery or in an emergency situation to bypass life threatening upper airway obstruction
- constant supervision
- selection of tubes available (low pressure cuffed type is best for animals to be maintained under anaesthesia or on a ventilator. Non-cuffed type that have a removable central sleeve to facilitate cleaning for chronic use. Selection of sizes).
Outline placement of a tracheotomy (temporary tracheostomy) tube
- septic (if non-emergency)
- ventral midline incision (neck), 2-4cm caudal to larynx
- long stay sutures placed around tracheal rings with a separation of two tracheal rings (2-0 monofilament)
- transverse incision between 4th and 5th tracheal rings between the stay sutures
- tube placed in tracheal lumen
- skin closed around the trachoestomy tube and the tube is secured by passing umbilical tape or similar around the dog’s neck. The pre-placed stay sutures are tied in a loose bow.
How does a tracheotomy animal need to be cared for? 5
- constant monitoring
- insert sleeve removed and cleaned every 2 hours
- nebulisation every 4 hours
- limit physical activity
- suction tube (if plugged but increases inflammation)
When is a tracheotomy tube removed?
once the dog has demonstrated adequate upper airway air movement (air around tube)
How is the tracheotomy tube removed?
with the dog conscious and the hole left to heal by 2nd intention
What are the 3 main conditions of the larynx?
- laryngeal paralysis
- laryngeal neoplasia
- granulomatous laryngitis
What are the 3 aetiopathologies for laryngeal paralysis?
- CONGENITAL - Bouvier des Flandres, Husky
- ACQUIRED (KNOWN) - trauma, neoplasia, secondary to polyneuropathy/polymyopathy (hypothyroidism etc)
- ACQUIRED (IDIOPATHIC) - labrador, retriever
CS - laryngeal paralysis
- chronic progressive exercise intolerance
- dysphonia
- increased resp. noise (especially inspiratory, stridor)
- chronic cough
- cyanosis and collapse (heat, stress, excitement)
What should you do in an obstructive crisis of laryngeal paralysis 5
- often hyperthermic –> cool IV fluids, external body cooling
- sedation
- oxygen supplementation
- occasionally rapid anaesthetic induction and orotracheal intubation
- tube tracheostomy will permit complete patient evaluation prior to definitive treatment.
How should you further investigate a stable patient with laryngeal paralysis? 4
- careful PE
- haematology and biochemistry (con/intercurrent disease)
- thoracic radiographs (pulmonary disease, mediastinal mass)
- careful evaluation of laryngeal function under light plane of anaesthesia
What should you do if you localise the laryngeal paralysis to the left arytenoid?
suture the arytenoid to teh thyroid (lateralisation) or cricoid (formation of prosthetic cricoarytenoid dorsalis muscle = laryngoplasty)
Post - op care after laryngeal paralysis treatment. 4
- avoid excitement
- keep tracheostomy tube handy in case post-op oedema causes further obstruction
- typically cough for 2-3 weeks following this procedure
- risk of aspiration pneumonia (greater with bilateral surgery)
What is the treatmetn for laryngeal paralysis?
left arytenoid lateralisation
Outline laryngeal neoplasia
rare, mostly malignant
- Congenital rhabdomyosarcoma (oncocytoma)
- SCC
- adenocarcinoma
- fibrosarcoma
- lymphoma (cat)
CS - laryngeal neoplasia
- dysphonia
- sonorous respiration
- exercise intolerance
- respiratory distress
- may be indistinguishable from laryngeal paralysis*
What is granulomatous laryngitis?
dog and cat
affected animals present in similar way to laryngeal paralysis and laryngeal tumours
presence of this disease mandates BIOPSY
Name 2 surgical conditions of the trachea
- tracheal collapse
- tracheal trauma
What breeds does tracheal collapse tend to affect?
toy and small terrier (esp. YT)
What is tracheal collapse the result of? 3
poor tracheal cartilage development and poor tracheal conformation (low GAGs and low cellularity). May be exacerbated by LRT infections, heart disease and/or laryngeal dysfunction.
When does tracheal collapse cause a problem?
although present from birth, the disease causes a clinical problem in mid to late life (4-7 years). collapse is worsened by obesity.
CS - tracheal collapse
- vibrant inspiratory and expiratory noise (exacerbated by exercise, excitement)
- goose honk cough
- cyanosis and collaspe (extremes)
- DV flattening of trachea can be palpated in neck and gentle pressure can completely occlude the airway (harder if obese)
Investigative steps - tracheal collaspe
- plain radiographs misleading
- thoracic radiographs - heart and lungs
- fluoroscopy - much better for demonstration of tracheal collapse because this is a dynamic condition
- endoscopy
- laryngoscopy (to determine if normal, especially if considering surgery)
What part of the trachea is affected by tracheal collapse?
most commonly the entire trachea is affected, even if only cervical tracheal collapse can be documented by investigation
Treatment - tracheal collapse
- older dogs are likely to have other important diseases at the same time (heart, larynx, metabolic/endocrine - cushings)
- 1st line tx - medical (treat respiratory infection, steroids to control oedema of respiratory tract, weight loss programme)
- 2nd line tx (where tracheal collapse is the primary disease or where conservative management has failed) - salvage procedure, technically demanding surgery, place prosthetic rings around trachea (ventral midline approach), may need to be combined with arytenoid lateralisation with laryngeal function is poor prior to or as a result of surgery)
When are intralumenal stents indicated?
older dogs with co-morbid disease as a palliative measure (long term complications associated with this method means it is contra-indicated in young dogs)
What are the commonest causes of tracheal laceration?
neck bite wounds, traumatic intubation. In cats, blunt trauma to the chest may cause tracheal rupture/avulsion, most commonly just cranial to the carina ‘ intrathoracic tracheal avulsion’
CS - tracheal trauma -4
- SC emphysema which can become generalised over teh whole body
- pneumomediastinum
- pneumothorax
- respiratory distress (varies with head position)
Diagnosis - tracheal trauma
- can be challenging
- cerivcal and thoracic radiographs may show peri-tracheal, IM and SC emphysema. Pneumomediastinum and pneumothorax may be present too.
- positive contrast studies may be useful
- bronchoscopy (diagnose and locate teh lesion)
- exploratory surgery
Where are tracheal tears from intubation most commonly found?
dorsal wall of the cervical trachea
Tx - tracheal tauma -2
- conservative therapy with strict cage rest and observation (if stable and non-progressive)
- surgical therapy warranted if CS are progressive and if respiratory distress is severe
How are tracheobronchial FBs dealt with?
usually removed endoscopically or using fluoroscopic guidance, these cases are rarely surgical.
List 3 surgical conditions of the lung
- primary lung tumour
- spontaneous pneumothorax
- lung lobe torsion
How common are primary lung tumours in dogs?
Uncommon. Most are malignant, adenocarcinoma is the most common type.
CS - lung tumour
- cough (50%)
- dyspnoea (23%)
- lethargy (18%)
- weight loss (12%)
- no CS (25%)
Diagnosis - lung tumoour
- thoracic radiographs and/or CT (when a mass lesion is detected on thoracic radiography, every effort should be made to exclude the existence of a primary tumour elsewhere in the animal)
Treatment - lung tumour
- exploratory thoracotomy and lung lobectomy (if no other disease found)
Prognosis - differentiated lung adenocarcinomas without local LN involvement
longest post-op survival times
How often should lung cancer dogs be rechecked?
every 3-6 months after surgery and thoracic radiographs made to check for recurrent disease
When does a pneumothorax occur and how is a spontaneous pneumothorax different?
Pneumothorax - when atmospheric air enters the pleural space. Spontaneous pneumothorax - this is a ‘closed’ pneumothorax in which the lung is suspected as the source of the leakage and the animal has no hx of trauma.
Aetiology - pneumothorax - 5
- ruptured pulmonary bullae or blebs
- migrating inhaled plant material
- bacterial pneumonia
- chronic obstructive lung diseases (emphysema and chronic bronchitis)
- asthma, TB, pulmonary neoplasia airway parasites (filaroides)
CS - pneumothorax
- tachypnoea
- dyspnoea
- exercise intolerance
- absence of lung sounds on auscultation and thoracic resonance on percussion
- radiography/ CT (care dyspnoeic animal, single DV?)
Treatment - pneumothorax - 3
- stabilise - thoracocentesis or chest tube indicated
- exploratory thoracotomy via median sternotomy and removed of disease lobe(s)
- prolonged pleural evacuation using a chest drain
How common is lung lobe torsion?
uncommon but is reported in both dogs and cats. dogs with narrow, deep chests appear to be more frequently affected. The middle and right cranial lung lobes are most frequently involved.
What can lung lobe torsion be association with?
This condition can be associated with pleural effusions, trauma, thoracic surgery, neoplasia and chronic respiratory disease.
CS - lung lobe torsion
depressed inappetant febrile dyspnoea + cough muffled lung sounds thoracocentesis, thoracic ultrasound, radiography, CT Repeat imaging once drained
Treatment - lung lobe torsion
lobectomy of the affected lobe
Outline the surgical approach to the diaphragm
the most versatile approach to the diaphragm is the VENTRAL MIDLINE CELIOTOMY which can be extended into a CAUDAL MIDLINE STERNOTOMY if further exposure is needed
Define DR
diaphragmatic rupture
Pathogenesis - DR
blunt abdominal trauma causes a sudden elevation in intra-abdominal pressure that results in rupture of the weakest (muscular) portion
What does the pathophysiology of DR focus on?
Acute and chronic consequences of this?
loss of diaphragmatic contribution to pulmonary ventilation and the resulting dyspnoea. Also migration of abdominal organs into thoracic cavity.
ACUTE - pulmonary contusions (bruises), rib fractures, pneumothorax, haemothorax and pain all exacerbate poor pulmonary function
CHRONIC - effusion from surface of entrapped or strangulated organs –> hydrothorax which also compromises lung function. GIT disease signs
Diagnosis - diaphragmatic rupture -3
- PE - muffled heart sounds, loss of lung sounds, dull thoracic percussion, empty abdomen on palpation.
- Radiography - confirms acute DR (may be obscured chronically by pleural effusion)
- OTHERS: repeat thoracic radiographs, ultrasound, GIT contrast studies, positive contrast peritoneography
What should the acute DR trauma patient be checked for?
multi-system onvolvement
Treatment - DR
acute versus chronic
ACTUE CASES: 24-48hrs medical stabilisation prior to surgical repair of the rupture BUT immediate action if radiography reveals a dilated stomach within thoracic cavity (trans-thoracic gastrocentesis). If gastric decompression can be maintained by NGT, continue non-surgical therapy.
- CHRONIC - fluid removal prior to surgery
Outline surgical repair of DR
Expose diaphragm - examine defect - remove abdominal organs from thorax (enlarge defect sometimes) - adhesions to be gently broken down - thoracostomy tube placed prior to closure of defect (large dogs or where ongoing effusion is anticipated) - debride edges of DR (chronic cases only) - closure achieved using a simple interrupted or continuous sutures incorporating a rib where avulsion from the lateral thoracic wall has occurred - full abdominal exploration - repair anything necessary - abdominal closure is routine.
Define PPDH
Peritoneopericardial diaphragmatic hernia
Pathogenesis - PPDH - 3
EITHER failure of septum transversum to advance OR failure of the lateral pleuroperitoneal folds to unite OR a result of intrauterine trauma
What other developmental abnormalities may PPDH be associated with? 2
- sternal and ventral abdominal wall fusion defects
- intracardiac defects (VSD, PS, ASD)
- PSS
Pathophysiology - PPDH - 4
- loss of intrapleural volume causing reduction in lung volume
- displaced GIT organs
- primary signs of CV compromise
- other vascular defects –> CNS, urinary and GIT signs
Diagnosis - PPDH
AS FOR DR:
- PE - muffled heart sounds, loss of lung sounds, dull thoracic percussion, empty abdomen on palpation.
- Radiography - confirms acute DR (may be obscured chronically by pleural effusion)
- OTHERS: repeat thoracic radiographs, ultrasound, GIT contrast studies, positive contrast peritoneography
Outline treatment - PPDH
- young patients asap (reduces risk of adhesion formation)
- older patients - incidental - manage conservatively
- surgery (most important if showing CS)
Outline PPDH surgery
Approach diaphragm and ID defect - return abdominal organs - break down any adhesions carefully - repair defect (without separation of pericardial membrane - simple interrupted or continuous sutures
Define EHH
Eosphageal Hiatal Hernia
What is Eosphageal Hiatal Hernia (EHH)
A congenital diaphragmatic disease
Pathogenesis - EHH
defect in the formation of the oesophageal hiatus, from the embryonic megaoesophagus
Which breed has hereditary EHH?
Chinese Shar-Pei
Pathophysiology - EHH
laxity in oesophageal hiatus –> allows abdominal oesophagus and stomach cardia to slide into thorax OR permits a portion of the stomach to enter the thorax adjacent to the abdominal oesophagus.
The problem relates to the impairement of the ‘high pressure zone’ of the caudal oesophagus resulting in chronic GIT reflux, regurgitation and/or vommitting –> chronic oesophagitis, oesophageal hypomobility and aspiration pneumonia.
Diagnosis - EHH - 4
- History
- PE - highlights secondary disease processes
- PLAIN FILM RADIOGRAPHY - shows a gas-filled viscus in the dorsocaudal thorax, alveolar pattern in CrV lung fields due to aspiration pneumonia
- OTHERS: barium paste oesophagram and fluoroscopy of the caudal thorax
Outline surgical treatment - EHH - 3
- ) STOMACH RETURNED TO ABDOMEN by gentle traction on phrenicosophageal ligament gently dissected free to improve ID of hiatal defect
- ) DEFECT CLOSED - begin dorsal to oesophagus and proceed ventrally with simple interrupted or continuous sutures. Include 4 interrupted ‘oesophagopexy’ sutures between the ventrolateral abdominal oesophagus and the diaphragmatic hiatu. Hiatus should be closed to a diameter of 2-3cm.
- ) GASTRIC FUNDUPEXY - either a tube gastrostomy or belt-loop gastropexy
List 3 surgical conditions of the diaphragm
ACQUIRED - DR
CONGENITAL - PPDH and EHH
Outline the general approach to treating thoracic wall trauma cases
global approach - immediate aim is to confirm adequate airway and effective ventilation - detect deficits in circulating blood volume and replace with ongoing circulatory support - analgesia - cover external wounds with sterile bandages - immobilise fractures limbs - thoracic radiographs to evaluate intrathoracic pathology and determine need for pleural drainage - frequent re-evluation of patient with objective and subjective measurements - BS AB cover for bite wound or massive trauma patients - specific therapy for thoracic wall is postponed - temporary thoracostomy tubes with LA - rapid surgical thoracic exploration if massive, uncontrollable haemorrhage or pneumothorax exceeds capacity of thoracostomy tube drainage
What are the 2 types of thoracic wall trauma
Non-penetrating and penetrating thoracic trauma
How can you manage non-penetrating thoracic trauma?
manage conservatively. superficial bite wounds or skin avulsion wounds should undergo surgical exploration and wound debridement
How can you manage penetrating thoracic trauma?
exploratory thoracotomy around the traumatic thoracic opening - aim of surgery should be to remove injured or devitalised tissue, provide pleural drainage and closure of thoracic walls using either native tissue or if tissue loss is extensive, synthetic (polypropylene) mesh
What effect will stabilising loose ribs and flail segments have?
unusual to normalise pulmonary function but will relieve pain and thereby improve ventilation
Why might a patient be stabilised for 24-48 hours prior definitive rib repair?
because of the progressive nature of massive pulmonary contusions, a period of mechanically assisted ventilation (24-48 hrs) and medical therapy may be beneficial.
How might flail segments and unstable ribs be immobilised?
by percutaneously placed circumcostal sutures secured to an external splint
How may ribs be stabilised?
suturing to adjacent ribs or resected if damage is severe. closure of the wound with native tissues is ideal but massive trauma may necessitate reconstruction with synthetic implants
What are the most common malignant primary tumours of the thoracic wall?
- Most commonly OSA and chondrosarcoma arising from the costochondral junction.
- Tumours of the chest wall such as HSA, MCT and infiltrative lipomas can also occur.
CS - tumours of thoracic wall
- palpable mass
- occasionally lameness (pulmonary osteoarthropathy)
Diagnosis - thoracic wall tumours
- Plain film radiography –>intrathoracic extent of tumour
- Thoracic CT and MRI - to document disease and plan surgery
Treatment - thoracic wall tumours
Because the biological behaviour of various tumours differ, an incisional biopsy should be performed. The definitive plan should be based on anatomical location, presence or absence of metastatic disease and the tissue diagnosis. Treatment = full thickness thoracic wall resection followed by reconstruction.
What is the rhinarium?
the moist, naked surface around the nostrils
Treatment - SCC of rhinarium
Wide local surgical excision (REFERRAL)
Treatment - MCT of rhinarium - 3
- Wide local surgical excision
- Adjunctive radiation therapy
- Chemotherapy (depending on histological grade and clinical stage)
Outline primary and secondary pathology of BAOD
PRIMARY - stenotic nares, long soft palate, ethmoid turbinates filling the meatus
SECONDARY - eversion of the mucosa of the lateral laryngeal ventricles, laryngeal collapse
Why does the larynx become oedematous in BAOD?
exercise –> mouth breathing –> soft palate vibration –> inflammation –> airway closes down –> vicious cycle. Larynx becomes oedematous because of inflammation and leads to laryngeal collapse.
Name 5 treatment options for laryngeal collapse
- orotracheal intubation
- emergency tracheostomy
- partial laryngectomy
- arytenoid lateralisation
- permanent tracheostomy
What does stridor indicate?
URT obstruction which is usually either:
- laryngeal collapse *
- laryngeal neoplasia
- laryngeal FB
Describe treatment objectives for laryngeal paralysis
- relieve obstructive crisis
- permanent increase in glottic diameter (intralaryngeal or extralaryngeal)
Outline the steps in unilateral arytenoid lateralisaion
- surgical treatment of laryngeal paralysis
- disarticulate arytenoid from thyroid and cricoid
- laryngoplasty sutures secure arytenoid, in abducted position, to thyroid and/or cricoid cartilage
- unilateral procedure.
What is the success of unilateral arytenoid lateralisation to treat laryngeal paralysis?
- overall 85-90% improved long-term
- short term complications in 30% (poor arytenoid abduction, haematoma formation, laryngeal penetration, aspiration pneumonia)
When is a tube tracheostomy indicated? 4
- when an ETT can’t be placed
- temporary airway diversion to permit oral cavity surgery
- long term ventilatory support
- emergency provision of airway
What size should a tracheostomy tube be?
50-60% internal lumenal diameter of the trachea (this means tube blockage is not life-threatening as air can pass round it)
What should you try not to damage when placing a tracheostomy tube?
parotid, vagus, oesophagus, recurrent laryngeal nn.
Indications for lung lobectomy 6
- primary lung tumour
- metastatic pulmonary mass
- lung lobe torsion
- pulmonary abscess/infection
- bullous damage
- trauma
Lung lobectomy - technique
- lateral 5th or 6th ICS thoracotomy
- isolate lung lobe (cut pulmonary ligament)
- identify PA, PV and bronchus
- clamp, divide and oversew bronchus
- check for leaks
- use US Surgical TA 30 vascular staple gun.
