Diagnosis Of Tracheal Collapse Research Articles

Radiographic evaluation of tracheal collapse in dogs by compressive technique

ABSTRACT The purpose of this study was to verify the applicability of the compressive radiographic technique (pressures of 5, 10, 15 and 20mmHg) in the diagnosis of tracheal collapse in small breed dogs, in lateral cervicothoracic radiography. Out of the 50 dogs evaluated, 25 presented tracheal collapse (TG group), 23 did not present tracheal collapse (CG) and two were excluded because they did not tolerate a pressure of 20 mmHg. The TG group presented a smaller internal diameter of the trachea in the region of the fourth cervical vertebra (D4) and at the entrance of the thorax (TDE) compared to the CG group, in all the radiographic projections performed, as well as within the TG group where the compressive technique differed from conventional. Furthermore, there was a correlation between the clinical sign of coughing during cervical collar use and the presence of radiographic tracheal collapse at a pressure of 20 mmHg. It was concluded that the compressive radiographic technique was feasible and efficient in confirming the diagnosis of tracheal collapse in dogs, especially in the pressure of 20 mmHg, where it was associated with clinical signs, and can be used in isolation or complementary to the conventional technique.

Tracheal Collapse in the dog: step by step from pathophysiology to management

Tracheal collapse (TC) is one of the most common causes of cough in small and toy breed dogs. Collapse typically occurs in a dorsoventral direction with prolapse of the flaccid dorsal tracheal membrane into the lumen. TC may affect just a part of the trachea or its entire length. Collapse of the cervical trachea occurs on inspiration, while thoracic part collapses on expiration. Tracheal collapse is a chronic multifactorial disease. It has been suggested that genetic, nutritional, neurologic and inflammatory factors contribute to its pathophysiology. Cartilage rings appear hypocellular, while the dorsal tracheal membrane becomes thicker. The disease is most commonly recognized in middle-aged small and toy breed dogs. No sex predilection has been established. Dogs can be obese or not. Tracheal collapse has been rarely reported in large breed dogs, cats, horses and goats. Tracheomalaciarepresents the analogous disease in humans. In 81% of cases the presenting complaint is a dry, high pitched, goose honking, paroxysmal cough that worsens over time (chronic form), which may be accompanied by exercise intolerance and cyanosis. Various factors could exacerbate clinical signs, such as barking, excitement, drinking or eating. Few cases are presented with the acute form of the disease. Concurrent diseases may worsen or exacerbate clinical signs. The most common finding upon physical examination is the goose honking dry cough that is elucidated on tracheal palpation; flattened and collapsible tracheal rings may be also detected. A concurrent disorder may contribute to physical examination findings. Plain lateral radiographs of the neck and thorax contribute to the diagnostic evaluation of TC in dogs. Their sensitivity varies from 42,8% to 82%. Tangenital radiographs of the neck, as well as tracheal fluoroscopy and ultrasound, may be helpful in the diagnosis of TC. The gold standard method for the diagnosis and staging of TC is tracheoscopy. According to an established grading system it is divided into four stages, which are characterized by the degree of reduction (25%, 50%, 75% and 90%) of the dorsoventral diameter of the tracheal lumen. The major advantage of tracheoscopy is that it can also evaluate the morphology and function of other organs of the respiratory system and it can contribute to the diagnosis of a concurrent disease. Tidal breathing Flow - Volume loop acquisition is a recently standardized diagnostic method that seems to be a quick and reliable diagnostic tool for the diagnosis and staging of TC in dogs. One of its major advantages is that it is performed in alert and untrained dogs. Dogs that are presented with the acute form of the disease must be handled with caution and clinical evaluation should be postponed until their stabilization. Dogs with TC may respond to medical management, surgical correction or to the use of intraluminal stents. Physical examination findings, history and the general condition of the dog will all contribute to the decision of the appropriate therapeutic modality.

Use of a double-wire woven uncovered nitinol stent for the treatment of refractory tracheal collapse in a dog: a case report

A 2.7 kg, 11-year-old, castrated male Maltese dog was presented for evaluation of a 2-year history of intractable coughing, dyspnoea and cyanosis. A diagnosis of tracheal collapse with myxomatous mitral valve disease was made on the basis of inspiratory and expiratory thoracic radiographs, fluoroscopy and echocardiography. Measurement for stent size selection was performed on thoracic radiographs. A 10 mm (diameter) × 70 mm (length) self-expanding double-wire woven uncovered nitinol stent was used for intratracheal implantation and was deployed under fluoroscopic guidance. On thoracic radiography seven days after surgery, the position of the stent remained unchanged. On presentation six months after surgery, the owner reported that the dog was doing well without medical management. Although studies of various intraluminal stents have been reported in dogs, to the authors’ knowledge, use of a double-wire woven uncovered nitinol stent has not been reported previously for the management of a dog with tracheal collapse. Since this particular type of stent with unfixed individual cells provided proper airway patency without stent fracture in the dog in this report, this stent might be used as an alternative to other commercially available nitinol stents in cases of thoracic inlet collapse.

Tracheal collapse diagnosed by multidetector computed tomography: evaluation of different image analysis methods

ABSTRACT Background: The gold standard for diagnosing excessive tracheal collapse is still evaluation during bronchoscopy. Today, multidetector computed tomography (MDCT) is used to confirm a suspicion of abnormal tracheal collapse. There is no gold standard for computed tomography (CT) image analysis of tracheal collapse. Purpose: To evaluate four different methods for the diagnosis of tracheal collapse using the images obtained through MDCT to help clinicians evaluate the images in daily practice. Objectives: 374 consecutive high-resolution CT scans with full inspiratory and end-expiratory CT scans were retrospectively analyzed. Methods: The images were analyzed in four different ways. The degree of collapse was based on cross-sectional areas of individual locations or volumes of entire regions: (1) 1 cm above the carina, (2) the level of maximal collapse of the trachea, (3) the entire region from the carina to the thoracic inlet, and (4) the trachea and bronchial region as defined by the software. Results: We compared three existing and one new method for image analysis of tracheal collapse by MDCT. The prevalence of tracheal collapse varied from 10.7% to 19.5% in this cohort of patients suffering from mixed lung diseases when using an expiratory collapse of ≥50% as a threshold. The four methods were comparable with highly significant Pearsons correlation coefficients (0.764–0.856). However, the four methods identified different patients with collapse of ≥50%. There was no correlation between symptoms and the degree of collapse. Conclusion: The different methods identify tracheal collapse in different patients. Hence, the diagnosis of excessive tracheal collapse can not rely solely on MDCT images. Generally, there is a poor correlation between symptoms and the degree of collapse in the different methods. However, when using the maximal collapse, there is some correlation with symptoms. When in doubt regarding the diagnosis, further investigations, such as bronchoscopy, should be carried out.

Use of Nitinol Stents for End‐Stage Tracheal Collapse in Dogs

To report bronchoscopic placement of nitinol stents (Vet Stent-Trachea®) for improvement of end-stage clinical signs in dogs with tracheal collapse. Case series. Dogs (n = 18). Medical records (January 1, 2004-October 31, 2008) were searched for dogs with a diagnosis of tracheal collapse; 18 dogs met inclusion criteria. Tracheal diameter was compared before and after stent deployment. Stent dimensions were compared after stent deployment and at radiographic follow-up. There was a significant difference in the minimum tracheal diameter when initial and post deployment tracheal diameters were compared (P = .003). Stent length was significantly shorter at follow-up when compared to post deployment measurements (P = .004). Owner assessment of outcome was available for all dogs with 11.1% mortality within 60 days. Complications were documented in 9 dogs. Use of a nitinol stent (Vet Stent-Trachea®) in dogs with end-stage tracheal collapse is associated with a fair to good outcome despite significant temporal stent fore shortening after bronchoscopic placement.

Tidal Breathing Flow-Volume Loop Analysis for the Diagnosis and Staging of Tracheal Collapse in Dogs

Tracheoscopy is generally used for the diagnosis of tracheal collapse (TC) in dogs; yet, it is costly, requires anesthesia, and can irritate the airway. The tidal breathing flow-volume loop (TBFVL) is a safe, quick, and noninvasive pulmonary function test currently used in humans. TBFVL will differentiate dogs with TC from healthy controls and contribute to disease grading. Twenty-eight dogs with naturally occurring TC and 10 healthy controls. Cross-sectional, prospective clinical study: The 38 dogs were assigned to one of 4 groups based on tracheoscopy results: group A (n=10, healthy controls), group B (n=10, grade I TC), group C (n=10, grade II TC), and group D (n=8, grade III TC). The TBFVL measurement was performed on all dogs and loops were assessed for their shape. Forty-four TBFVL parameters were calculated. Two types of TBFVL shapes were identified: Type I, representative of the 10 healthy controls, and Type II, representative of the 28 dogs with TC. Statistical analysis showed the dogs could be differentiated into healthy or affected by TC by 3 indices, TE/TI (expiratory time divided by inspiratory time), TI/TTOT (inspiratory time divided by total respiratory time), and EF75/IF75 (expiratory flow at end tidal volume plus 75% end tidal volume divided by inspiratory flow at end tidal volume plus 75% end tidal volume). The TC could also be graded as mild-moderate (grades I and II) or severe (grade III), showing a diagnostic value of 97.4%. TBFVL is accurate, quick, noninvasive, and safe and can contribute to the diagnosis of TC in dogs.

A case of tracheal collapse in the dog

An eight-year-old male Yorkshire terrier which had had a cough for two years was presented and a diagnosis of tracheal collapse was made after examination with a bronchoscope. It was decided to try to correct the tracheal defect by plication. Two weeks after the operation the dog was examined under general anaesthesia. Although traction had exposed a part of the thoracic trachea it was not sufficient in this case to achieve a complete repair. In view of a grave prognosis, the dog was destroyed.