lower airway and pleural space sx

what are considered part of the lower respiratory system?

• trachea/bronci

• lungs

• pleural sapce

• thoracic wall

what is the anatomy of the trachea?

• 34-44 C shaped cartilagnious rings

• annular ligaments

• dorasl tracheal membrane

• vascular supply - segmental

• recurrent laryngeal nerves

what is the dorsal tracheal membrane made up of?

• mucosa

• connective tissue

• trachealis muscle

what is the vascular supply of the trachea?

• cranial and caudal thyroid arteries

• bronchial arteries

where do the recurrent laryngeal nerves span?

from dorsolateral edges of trachea cranial to heart

what is the common surgical approach to the cervical trachea?

• ventral midline skin incision and spread the muscles apart

what is the surgical approach to the thoracic trachea?

right 3rd or 4th intercostal thoracotomy

why do we go on the right side of the thorax?

to avoid the esophagus

what are the congential diseases of the tracheal and bronchi?

• tracheal collapse

• tracheal hypoplasia

what is the signalment and clinical signs of tracheal collapse?

• primarily miniature and toy breeds

• typical age at dx = 7 years old

• coughing

• dyspnea

on inhalation, what section of the tracheal collapses?

cervical

on exhalation, what part of the trachea collapses?

thoracic

what is the pathology of tracheal collapse?

• congenitally hypoplastic or fibrodystrophic cartilaginous rings

• redundant or weak dorsal tracheal membrane

• may involve both cervical and thoracic trachea

• may extend to mainstem bronchi (and lower)

• four grades of tracheal collapse based on % of lumen reduction

what are the grades of tracheal collpase?

• grade 1 = 25% lumen reduction

• grade 2 = 50% lumen reduction

• grade 3 = 75% lumen reduction

• grade 4 = almost no lumen

how to dx tracheal collapse?

• cervical palpation

• radiography

  • inspiratory/expiratory cervical and thoracic rads

  • fluoroscopy

• tracheoscophy (with bronchoscopy)

  • grade collapse

  • rule out concurrent disease (cytology and culture)

• laryngoscopy

  • rule out concurrent laryngeal paralysis

what is the tracheoscopic appearance of tracheal collapse?

C or D shape to lumen

what is the medical treatment of tracheal collapse?

• typically preferred vs sx, esp for grade 1 and 2

• cough suppressants

• bronchodilators

• antibiotics → if complicated by bacterial infection

• control complicating factors

  • obesity

  • heat stress

  • leash irritation

when is surgical correction indicated for tracheal collapse?

when medical treatment cannot control clinical signs

what is the caveat to surgical treatment for tracheal collapse?

limited ability to alleviate bronchial collapse

what is sx treatment for tracheal collapse?

intraluminal stents or extraluminal prostheses

how is an intraluminal stent placed?

placed with aid of fluoroscopy or tracheoscopy

What is dorsal tracheal membrane plication?

plicating the dorsal portion of the trachea, HOWEVER not typically performed because it requires relatively normal tracheal cartilages

what are extraluminal prostheses made from?

polypropylene syringe or syringe cases

what is tracheal hypoplasia?

• dorsally closed tracheal rings

• small, firm trachea on palpation

• small diameter trachea on radiographs

• english bulldogs predominately

• no surgical cure and no treatment

what are the consequences of injury to trachea and bronchi?

may result in air leakage and/or stenosis

what causes internal injury?

• intubation

• foreign bodies

what causes external injury?

blunt or penetrating trauma

what is tracheal stenosis?

narrowing of the trachea from scar tissue due to trauma

how to dx tracheal stenosis?

• radiography

• tracheoscopy

tracheal stenosis treatment options?

• bougienage → dilation

• balloon dilatation

• stent → scar tissue may be too mature

• resection/anastomosis

tracheal and bronchial foreign bodies

• clinical signs = acute cough, sometimes dyspnea

• dx = radiography and tracheobronchoscopy

• treatment = endoscopic retrieval, tracheotomy or bronchotomy, lung lobectomy

tracheal blunt or penetrating clinical signs

persistent peritracheal, subcutaneous, and/or mediastinal emphysema

what is the treatment of tracheal trauma?

most tears resolve without surgical intervention

what is the emergency care of cervical trachea trauma?

• may require orotracheal intubation or intubation through tracheal defect

• wound management

what is the emergency care of thoracic trachea (and bronchi) trauma?

monitor for pneumothorax and treat as indicated

T/F most tracheal lacerations are self-limiting

true

what are the surgical treatment options for tracheal lacerations when needed?

• can perform primary repair if there is reason to surgically expose the affected area

• consider temp tracheostomy to decrease airway resistance → rarely necessary

• resection/anastomosis if severe trauma or if stenosis results

• exploratory thoracotomy if unable to resolve pneumothorax

what is a tracheal transection?

near the carina, the trachea is ripped off the lungs

this occurs in cats

what is the surgical treatment of tracheal transection?

• right 3rd and 4th intercostal thoracotomy for anastomosis

• requires delicate maneuvering of endotracheal tube and trachea

T/F neoplasia of the trachea and bronchi is very common

FALSE → uncommon

what are the complications that neoplasia of the trachea and bronchi?

• intraluminal and/or extraluminal obstruction

• progressive dyspnea

what is the highest number of tracheal rings successfully resected in a dog?

17

what are the 3 anastomotic techniques for tracheal anastomosis?

• split-cartilage technique

• annular ligament-cartilage technique

• interannular technique

need tension-relieving sutures

what is partial replacement of tracheal reconstruction sx?

• periosteum, polypropylene mesh, silicone rubber, vascularized pedicle flaps (diagram, stomach, sternohyoideus muscle)

what is segmental replacement of the tracheal?

• 1-4 cm circumferential segment

• rib periosteum, auricular cartilage

are synthetic replacement of tracheal sucessful?

tend to fail due infection and stenosis

what are the 2 types of tracheostomy?

• temporary tracheostomy

• permanent tracheostomy

what are the indications of tube tracheostomy?

• life-threatening upper airway obstruction

• ventilatory assistance

• removal of secretions and aspirated material

• inhalation anesthesia for upper respiratory and intraoral surgery

what is a tube tracheostomy that is with or without inflatable cuff?

• cuff needed for anesthesia and ventilatory assistance

• tube without cuff preferred (safer) for simple maintenance of patent airway

tube tracheostomy with detachable inner tube

• facilitates cleaning, suctioning

• not available in small-sized tubes

what is a “home-made” tube for a tracheostomy?

fashioned from standard endotracheal tube

what is the prep for tube tracheostomy?

• capture airway with endotracheal tube

  • prepare patient for controlled surgical approach

  • “slash” tracheostomy rarely necessary

• dorsal recumbence

• standard aseptic preparation of neck from chin to manubrium

tube tracheostomy surgical technique

• ventral midline incision from cricoid cartilage to about 3-4 cm caudally

• separate sternohyoiedus muscles on midline

• transverse interannular incision between tracheal rings 2 and 3

• knotted stay sutures around rings 2 and 3

• insert and secure tube with umbilical tapes tied behind the neck

tube tracheostomy skin incision

interannular incision

introduction of tracheostomy tube with aid of stay sutures

what are the 3 main tracheostomy tube care?

• humidification = humified air and saline injection

• frequent aseptic cleaning = q 1hr, sanitize materials (chlorhexidine), gloves, sterile supplies as much as is practical

• airway suctioning = avoid mucosal injury

how is a tracheostomy tube removed?

• removal after effective breathing around tube

• allow wound to heal by second intention

what are the indications for permanent tracheostomy?

• salvage procedure

• untreatable upper airway obstruction

• upper airway treatment failure

what is the surgical technique of permanent tracheostomy?

permanent tracheostomy suturing stoma

what is an alternative location for permanent tracheostomy?

cricotracheostomy

what is the long term care of a permanent tracheostomy?

• maintenance of opening → clipping hair as needed

• no swimming

• protection from foreign bodies → plant material

• can be surgically reversed if warranted → incise skin-mucosa junction and suture skin edges

what are the surgical conditions of the lungs?

• pulmonary cyst

• pulmonary bullae/blebs

• pulmonary abscess

• restrictive pleuritis

• bronchiectasis

• bronchial foreign bodies

• lung laceration

• lung lobe torsion

• pulmonary neoplasia

what are pulmonary cysts, bullae, and blebs?

• congential or acquired

• may contain fluid or air

cysts are lined with

epithelium

what might cause spontaneous (idiopathic) pneumothorax?

bullae and bleds and a median sternotomy recommended

what is a bulla?

deep in lung, sometimes requiring attentive palpation to locate

what is a bleb?

located peripherally in the lung and is easily seen

what are pulmonary abscesses?

• uncommon

• can cause chronic debilitating disease

• rupture could result in pneumothorax or pyothorax

what are pulmonary abscesses secondary to?

• foreign body obstruction or migration

• chronic lung infection

• neoplastic disease

what is the medical treatment for pulmonary abscesses?

• appropriate antibiotic therapy

• pleural drainage if pyothorax

what is the surgical treatment of pulmonary abscesses?

• if medical management ineffective

• exploratory thoracotomy and (partial) lung lobectomy

what is restrictive pleuritis?

• heavy fibrin deposition after trauma or inflammation of the pleura

• sequela to chylothorax

• restricts lung expansion

what is the surgical treatment of restrictive pleuritis?

• lung decortication

• poor results

bronchiectasis

• congenital or acquired dilation of bronchi and bronchioles

• contributes to recurrent respiratory infections

what is the surgical treatmnent for bronchiectasis?

lobectomy of affected lung lobes if only one or two lobes are involved

what might bronchial foreign bodies require?

may require lung lobectomy if foreign body cannot be removed endoscopically or if it migrates through lung

lung lacerations are usually

small and resolves spontaneously with aid of thoracic drainage

what are the causes of lung lacerations?

• iatrogenic

  • thoracocentesis

  • thoracostomy tube

  • inadvertent cur during thoracotomy

• rib fractures

• penetrating trauma → often fatal

what are the indications for lung laceration surgical treatment?

• uncontrollable or unresolving penumothorax

• ongoing intrathoracic hemorrhage > 2ml/kg/hr

what are the techniques for surgical treatment for lung lacerations?

• continuous inverting suture pattern → lembert

• deep hemostatic mattress suture with simple continuous closure of laceration

• partial or complete lobectomy

lung lobe torsion

• uncommon

• deep, narrow-chested dogs

• right middle lobe most common → followed by right cranial and left cranial

• congested, consolidated lobe

• pleural effusion → serosanguinous or chylous

what is the treatment of a lung lobe torsion?

lobectomy → do not untwist

what form of pulmonary neoplasia is most common?

metastatic

T/F some survival benefit to pulmonary metastsectomy in dogs with less than 3 pulmonary metastatic osteosarcoma lesions

true

what is the most common primary pulmonary neoplasia?

pulmonary adenocarcinoma → sometimes amenable to excision

surgical lung biopsy is essentially the same as what?

partial lung lobectomy

how is a partial lung lobectomy with sutures performed?

1) clamps proximal to lesions

2) continuous horizontal mattress pattern proximal to clamps

3) incision between clamps and horizontal mattress, or between clamps and lesion as illustrated

4) simple continuous oversew of incised edge

how is a complete pulmonary lobectomy performed?

• dissect hilus to identify pulmonary artery, bronchus. and pulmonary

• ligate/divide artery, then vein, then bronchus

pneumonectomy

• excision of entire lung on one side of thorax

• can remove 50% of lung acutely → probably more if non-diseased lung already compensanting

• technique similar to complete lobectomy → multuple lobectomies on one side

what are the indications for thoracostomy tube?

• postoperative throacotomy → manage residual air and fluid

• management of pneumothorax

• management of pleural effusions

thoracostomy tube placement closed thorax

• special tube with trochar stylet → alternative = tube tip in tips of hemostatic forceps

• stab skin incision (as small as possible) → doral 1/3 of lateral thorax near 10th to 12th ICS

• sub-latissimal tunnel → cranioventrally to 7th or 8th ICS at mid-thorax

• controlled “thrust” into thorax → or puncture ICS with forceps before introducing tube

thoracostomy tube placement open thorax

• placed at time of thoraotomy closure of thorax

• trochar-type not necessary

thoracostomy tube optimal placement

thoracostomy tube → securing the tube

what are the surgical approaches to the pleural space?

• intercostal thoracotomy

• rib osteotomy thoracotomy

• rib pivot thoractomy

• rib resection thoractomy

• transternal thoracotomy

• median sternotomy (or paramedian sternotomy)

• transdiaphragmatic approach

intercostal thoracotomy

• preferred surgical approach because of simplicity

• left or right, 3rd to 10th ICS

• limited access → appropriate approach when surgically correctable abnormality is localized and defined

• postoperative morbidity (lameness) can be minimized by retraction (rather than incision) of the latissimus dorsi muscle

left 4th ICS thoracotomy → latissimus dorsi muscle retraction

methods to increase exposure for intercostal thoracotomy

• rib osteotomy

• rib pivot

• rib resection