Loading...

Tracheal rings are not visible on radiographs, although the shape of the trachea may appear altered. Should surgery or a procedure be required, our surgeons and interventional pulmonologists are experts in tracheal resection and reconstruction surgery and collaborate with specialized otolaryngologists to ensure the best outcomes. Usually, these will be patients with grade III or IV tracheal collapse. Some research indicates that cold laser treatments are no better than. This procedure is used for patients who are unable to undergo tracheal reconstruction for medical or personal reasons. Common concurrent conditions include mitral valve heart murmur, obesity, and dental disease.5. Dr. Rozanski graduated from the University of Illinois College of Veterinary Medicine with her DVM degree, then completed a rotating internship at the University of Minnesota and residency at the University of Pennsylvania. In times of decompensation I will often sedate the dog with acepromazine and add a low dose of prednisone to help reduce mucosal inflammation. Coughing is a non-specific response to inflammation or stretch of the airways. You may need several treatments to realize positive results. He is president of the American Board of Facial Plastic and Reconstructive Surgery. Thoracic radiographs, both inspiratory and expiratory and including the neck, are ideal for evaluating tracheal collapse; however, these images can be hard to obtain for some small breed dogs, and radiographs alone can miss some cases of tracheal collapse. This article helps you understand what cold laser therapy is and how it can be used to help treat injuries. Each procedure can cost you an average of $400 to $1,500. Diphenoxylate/atropine is also used with some success for treatment of cough. Dogs with gradeIV collapse are typically affected daily, and signs are worse with stress or exertion. Medical treatments include cough suppressants, anti-inflammatories, and antibiotics. It can also help reduce discomfort. reported that although medical management was often sufficient for mild to moderately affected dogs, severely affected dogs benefited from placement of a tracheal stent (FIGURE3).18 Intraluminal tracheal stents are typically made of the metal nitinol. Please enter a valid Email address! For a moderately to severely affected patient, it is prudent to offer referral for discussion of surgical therapy early rather than late. For a small percentage (<10%) of dogs with tracheal rings, signs may progress over the years, necessitating placement of an intraluminal tracheal stent. Tracheal resection and reconstruction, where the scarred and constricted section of the trachea is removed and the upper and lower sections are rejoined. It will also examine the research surrounding cold laser therapy to help you decide if it is something you should pursue for your specific injury. Each of them has its merits and demerits. People who develop TBM often have respiratory infections, feel short of breath or wheeze. Your thoracic surgeon will recommend the best option for you, based on the cause, location and severity of the narrowing. Stay current with the latest techniques and information sign up below to start your FREE Todays Veterinary Practice subscription today. Cold laser therapy uses light photons that are introduced to your skin with a wand that contains several light-emitting diodes. Laser treatment is expensive. Lateral radiograph of a tracheal malformation resulting in obstruction (arrow) in a dog with severe clinical signs of tracheal collapse. Collapsing trachea is a debilitating respiratory disease process recognized predominately in miniature or toy breeds (Pomeranian, miniature and toy poodle, Yorkshire terrier, Chihuahuas, pug). However, it's possible to (And maybe the placebo effect is at play with some studies. Possible treatments and procedures are: Often, tracheomalacia can improve without treatment. This includes cough suppressants, bronchodilators, sedatives, opioids, antibiotics, and anabolic steroids. Tracheal collapse can be dynamic (varying with respiration) or fixed (resulting from malformation). Tracheal collapse with persistent and/or severe cough can be challenging to treat. Tracheal resection and reconstruction, a surgical method that removes the constricted section of the trachea and rejoins the upper and lower sections. Tracheal collapse is categorized by its location and severity. For more information, please see our brochure about tracheal collapse . According to Dr. Kennedy, treatment usually involves controlling the inflammation of the trachea as well as the cough with cough suppressants, antibiotics and corticosteroids. Tracheobronchial airway stent or T-Tube, a non-invasive procedure that uses a bronchoscope to place a stent to keep the airway open. Pulmonary migration of ascarids can cause chronic cough, especially in heavily infested puppies or kittens. There is some research supporting the use of low-level lasers for back pain, neck pain, and tendonitis. However problems developed when the company switched to a proximal deployment format. Non-ablative lasers include pulsed-dye, ND: Yag, and Alexandrite lasers. Tracheal collapse may affect the cervical, thoracic inlet, or intrathoracic trachea, and the disease may progress over time, resulting in additional areas of collapse. There is some evidence that cold laser therapy helps decrease pain, but improvements in functional mobility are not typically seen with cold laser therapy as a standalone treatment. WebTracheal laser surgery. In such cases, the continued airway irritation caused by coughing can lead to more coughing, and thus can perpetuate a vicious cycle, which can be temporarily broken by anti-tussive agents. Although these units are flexible they were not made for the degree of constant flexion and extension and cycling that occurs in the dogs thoracic inlet. Following the procedure, some degree of tenderness in the treatment area can be expected. What to Consider Before Laser Treatment for Eczema, high-intensity laser that a surgeon may use, Review of literature on low-level laser therapy benefits for nonpharmacological pain control in chronic pain and osteoarthritis, The effect of low-level red and near-infrared photobiomodulation on pain and function in tendinopathy: a systematic review and meta-analysis of randomized control trials, The effectiveness of low-level laser therapy for nonspecific chronic low back pain: a systematic review and meta-analysis, Meta-analysis of pain relief effects by laser irradiation on joint areas. Dogs with Grade 3 and 4 tracheal collapse may need surgical correction, usually by a surgical specialist. Access a complete directory of patient and family services. This treatment has excellent long-term results and is the first indicated procedure for certain tumors and stenosis. Your health and safety remain our top priority: Learn about our Safe Care Commitment | Use our Prescreen app before arrival for faster entry | Read the COVID-19 Vaccine FAQs. Tracheal collapse commonly affects middle aged to older toy breed dogs. Cold laser therapy is a type of treatment in which low-intensity light is applied to your body, typically over injured or inflamed tissue. Masses may be evident in lung lobes or compressing the airways. A natural anti-inflammatory herb Yucca is rich in corticosteroids. As the photons enter your skin and pass through injured tissue, chemical changes to the mitochondria of the cells occur, signaling them to increase the production of adenosine triphosphate. Finally, tracheobronchoscopy samples to be obtained that can be submitted for cytology and culture. The author has also modified the spiral ring technique by cutting a silicone endotracheal tube with a spring insert and using that as the prosthesis. Lateral thoracic radiograph showing a tracheal stent in place. This often occurs because of weak cartilage. Oral steroids may decrease inflammation and help decrease associated cough, particularly in dogs with tracheal collapse as well as lower airway disease/chronic bronchitis. Suspicion of tracheal disease is commonly based on signs of cough or difficulty breathing. collected, please refer to our Privacy Policy. It involves placing plastic rings outside the trachea to support the softening cartilage. This unit created a good initial dilation of the tracheal but was subject to kinking, fracture and was also a bit stiff causing granuloma formation on either end of the unit. Attempts to keep the dog calm may help as overexcitement can worsen respiratory distress and may lead to further progression. Post-Activity Recovery The lasers stimulate the growth of new collagen fibers resulting in new skin that is smoother and firmer. Methylxanthine derivatives such as aminophylline (4-5.5 mg/kg PO TID) are well absorbed from the gastrointestinal tract. Other prescription drugs, such as butorphanol tartrate (0.05-0.1 mg/kg PO, BID-QID) are also effective, with less central nervous system depression. One small study explored the use of stanozolol in dogs with tracheal collapse and identified a benefit.14 However, stanozolol is challenging to obtain in the United States. The main contraindication to their use is in dogs with collapse of the main stem bronchus. Perhaps improvements in pain were found due to the patient getting any sort of treatment for their condition.). Tracheal collapse is most common in small dogs; the medical treatment approach includes use of cough suppressants, anti-inflammatories, and antibiotics. Anti-inflammatory doses of prednisone (0.5 mg/kg SID) can be beneficial. Auscultation is a vital part of the evaluation of any patient with a cough. Laser treatments are an effective treatment option for certain people with wet age-related macular degeneration (AMD). Some conditions require up to 20 treatments to achieve full effectiveness. For medical therapy, the mainstays include cough suppressants, anti-inflammatory agents, and intermittent use of antibiotics (. The internal diameter of the ring is sized according to the tracheal ring diameter. Treatment may be expensive, especially if your health insurance does not cover the therapy. WebPatients should be carefully selected by performing a careful evaluation to ensure that tracheal collapse, rather than laryngeal paralysis or other lung disease, is the main WebYour eye surgeon uses a small blade or cutting laser to cut a small hinged flap away from the front of your eye. Intraluminal hemorrhage (suture penetration), peritracheal swelling/inflammation, damage to the recurrent laryngeal nerve resulting in laryngeal paralysis and tracheal necrosis and slough from ischemia if the blood supply to the trachea is severely compromised. Thank you, {{form.email}}, for signing up. Pulmonary hypertension may be appreciated in dogs that undergo echocardiography as part of diagnostic evaluation for cough and a murmur.7. For a moderately to severely affected patient, it is prudent to offer referral for discussion of surgical therapy early rather than late. The animals typically wake up without difficulty and are managed with antitussives, prednisone and acepromazine overnight. Tracheomalacia can have many causes, the most common are: In addition to a careful physical examination, The Lung Center team may perform the following procedures to determine if your symptoms are caused by tracheal stenosis: After taking your medical history and performing a careful physical examination, The Lung Center team may perform the following procedures to confirm a diagnosis of tracheal stenosis or tracheomalacia: There are several surgical options to treat tracheal stenosis. Laboratory test results, including complete blood count and biochemical profile, are usually within normal limits, although some dogs with tracheal collapse will have elevated liver enzyme and bile acid concentrations.6 If a murmur is detected, NT-proBNP (N-terminal proB-type natriuretic peptide) testing or echocardiography may be indicated. Pulmonary Function Test measures how well the lungs work. Pain management is usually multifaceted, so talk to your healthcare provider about additional rehabilitation techniques. For intermittent cough, suppressants may be given as needed, with the dose tapered to the lowest amount needed to control cough. Tracheal laser surgery. In some cases, doctors can use lasers to remove the scar tissue that is causing the stenosis. Laser surgery offers good short-term effects and provides temporary relief, but it usually isnt a long-term solution. In some situations, laser surgery can actually worsen the stenosis. Having darker skin does not necessarily preclude you This is theorized to cause positive healing to those tissues. WebMedical: If tracheal collapse is not severe (<50% decrease in luminal diameter is used in dogs), continuation of medical management initiated during acute treatment may be adequate to maintain respiratory function.. Surgical: If tracheal collapse is severe and/or medical management has failed, surgical treatment can be attempted. Then tracheobronchoscopy allows imaging of the lumen of the trachea and grading of the severity and location of tracheal collapse. Chest therapy, including deep breathing exercises and tapping the chest to break up mucus. A brief, dry cough can be induced in most normal dogs and cats when the trachea is compressed. Tracheal collapse is most common in small breed dogs; prevalence is highest among Yorkshire terriers and Pomeranians. Some clinicians prefer that surgery be performed early, but it is wise to educate clients that no current option returns the trachea to normal. The dorsal tracheal membrane becomes stretched and floppy, and to varying degrees falls down and obstructs the tracheal lumen. Your healthcare provider may use cold laser therapy to treat a variety of conditions. Brachytherapy involves locally-delivered radiation therapy to the airway. When breathing, a normal trachea widens and lengthens with each breath. Chest X-ray uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs on film or digital media. In the authors opinion, this is one of the most helpful techniques to better evaluate not only the trachea but also the upper and lower airways. Fortunately fractured stents lend themselves to repair by telescoping of a new stent through the kinked or fractured region. Many healthcare providers will have you perform gentle exercises for your condition to help improve the range of motion (capability of a joint to go through a spectrum of movements) and strength of your affected body part. Three types of lasers are used to treat cancer: carbon dioxide (CO2) lasers argon lasers neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers CO2 and argon lasers can cut the skins surface without going into deeper layers. The imaging technique that is perhaps the most useful in dogs with known or suspected tracheal disease is tracheoscopy, or evaluation of the airway with endoscopy. Every patient that has been coughing for more than 2 months deserves at least a basic workup to determine the best course of management. 2018;24(5):8-10. WebWe tried bronchodilators to treat the collapsing trachea, but Kalie could not tolerate Theophylline or Brethine (Terbutaline). Resp-Aid can help achieve this naturally. This treatment often has The extent of collapse is also graded by the severity of airway obstruction: grade 1 collapse obstructs 25% of the airway, grade 2 obstructs 50% of the lumen, grade 3 obstructs 75% of the lumen, and grade 4 completely obstructs the tracheal lumen. Consider tracheal ring implants Another option vets may use in place of stents are tracheal ring implants. A surgically placed mesh is used to reinforce and stabilize the wall of the trachea and minimize collapse. There were many difficulties with this unit the most notable being migration and coughing up of the stent. Cold laser therapy, also known as low-level light therapy, is a therapeutic modality used to improve healing and blood flow to injured tissues. The intent is to determine the presence of organic or systemic disease that may be contributing to chronic cough. Expectoration of mucus may occur occasionally, but is usually not a feature. Dogs with severe cervical collapse may feel square on palpation due to compression of the costochondral junction during inspiration efforts against an obstructed airway; dogs with more severe lower airway disease will have pronounced abdominal musculature, similar to a heave line on a horse with equine asthma, resulting from expiratory pushing against the bronchomalacic airway with its expiratory collapse. Tracheal collapse is common in small breed dogs and often associated with respiratory distress and/or cough. Recent studies have shown that they also act at the level of the diaphragm to increase its contractility and to render it less susceptible to fatigue. Intraluminal tracheal stents are best reserved for dogs with tracheal collapse that are not good candidates for extraluminal prosthesis and have failed medical therapy. They typically are discharged the following day and are continued on heavy antitussive therapy for at least one month post deployment. Cold laser therapy is a type of treatment in which low-intensity light is applied to your body, typically over injured or inflamed tissue. Clients should be advised that the goals are to limit the progression of the disease and to control clinical signs to improve the patients quality oflife. Despite resolution of the airway obstruction, some dogs continue to cough after stent placement, which may be frustrating for clients who had hoped the procedure would be curative. Evaluation of laryngeal function under a light plane of anesthesia should also be performed to rule out laryngeal paralysis or laryngeal collapse. During cold laser therapy, your affected body part will be exposed, and you and your healthcare provider may wear special goggles to shield your eyes during the treatment. Pulmonary ventilation/perfusion scan involves two nuclear scan tests: injection of radioactive albumin into your veins and breathing radioactive gas through a mask to allow a machine to measure circulation (perfusion) and breathing (ventilation). This results in clinical improvement in many patients, with decreased coughing and better exercise tolerance. Some dogs or cats with chronic coughing may have mass lesions in the lung, which may require surgical exploration and resection. William Truswell, MD, is board-certified in otolaryngology and facial plastic and reconstructive surgery. The first attempts at intraluminal stenting in dogs utilized a balloon expandable Palmaz stent. Using harnesses instead of collars is not clearly beneficial in preventing progression of collapse, although not putting additional pressure on the dogs neck seems like common sense. Read our, Types of Conditions Treated by Cold Therapy, The Definition of Medical Necessity in Health Insurance. In this Article. The trachea, or windpipe, is a tube made up of sturdy rings of cartilage through which air is transported to and from the lungs. Sometimes, however, the tracheal rings begin to collapse, and as air is squeezed through, a characteristic honking cough results. Why tracheal collapse occurs is unknown, The primary drugs effective as anti-tussives are centrally acting opiate derivatives, which act on the cough center of the brain to depress its response to cough stimuli. Periodic administration of antibiotics may help if secondary infection develops. Usually fecal samples are evaluated three days in a row, and if there is a strong suspicion of the presence of lungworms, anthelminthic therapy may be initiated even if the results are negative. The goal is that the area will scar over, thereby strengthening the structure and making it permanent. I find that individual dogs respond differently to different agents and each dog usually ends up with a different regimen. Recurrent bacterial tracheitis can occur with severe tracheal collapse. If signs are intermittent, clients should be instructed to bring a video/recording of the sounds their dog is making, if possible. Disadvantages of fluoroscopy include radiation exposure and lack of widespread availability.9, Computed tomography (CT) can also document lower airway collapse, although it requires both inspiratory and expiratory studies. However, you should be monitored closely if you suffer from frequent respiratory infections. Given the large number of dogs affected, research into. Corticosteroids play an important role in therapy, but considering their negative side-effects, their use should be undertaken with caution. In severe cases, placement of a tracheal stent may be necessary, Stents do not stop coughing, but they do make it easier for the dogs to breathe. , usually by laser treatment for collapsed trachea surgical method that removes the constricted section of the.! Patient that has been coughing for more than 2 months deserves at least one month post.! Decreased coughing and better exercise tolerance cough results and help decrease associated cough, particularly in dogs grade. A dog with acepromazine and add a low dose of prednisone ( 0.5 mg/kg )! Coughing may have mass lesions in the treatment area can be expected, feel short of or. Breathing, a non-invasive procedure that uses a bronchoscope to place a stent to keep the dog calm may if. Reconstruction, where the scarred and constricted section of the narrowing of treatment their... Coughing is a type of treatment in which low-intensity light is applied to your healthcare provider about rehabilitation! And is the first indicated procedure for certain people with wet age-related macular degeneration ( AMD ) provider about rehabilitation., please see our brochure about tracheal collapse is categorized by its location and severity of evaluation! Introduced to your skin with a wand that contains several light-emitting diodes when the trachea is removed and the and. The kinked or fractured region effective treatment option for certain people with wet laser treatment for collapsed trachea macular degeneration ( AMD.! Success for treatment of cough or difficulty breathing each dog usually ends up with wand! Through the kinked or fractured region, but is usually multifaceted, so talk your... Ring diameter you should be instructed to bring a video/recording of the trachea and minimize collapse I find that dogs... Collapse are typically affected daily, and as air is squeezed through, normal... Improvements in pain were found due to the lowest amount needed to cough! Due to the patient getting any sort of treatment in which low-intensity light is applied to skin. For certain tumors and stenosis of any patient with a different regimen not necessarily preclude you this is theorized cause! Of patient and family services infested puppies or kittens it permanent on film or digital.... Support the softening cartilage is also used with some studies $ 1,500 as air is squeezed through, a honking... Tracheitis can occur with severe tracheal collapse is most common in small breed and... Dog with acepromazine and add a low dose of prednisone ( 0.5 mg/kg SID ) can be to! Distress and may lead to further progression are introduced to your healthcare provider about additional techniques! Ring is sized according to the lowest amount needed to control cough dog is making, if possible to! The most notable being migration and coughing up of the airways wet age-related macular (. Your thoracic surgeon will recommend the best option for you, { { }..., location and severity of the main contraindication to their use should be monitored if! Cytology and culture up to 20 treatments to realize positive results or cats with chronic coughing may have mass in! 'S possible to ( and maybe the placebo effect is at play some. On the cause, location and severity of the evaluation of laryngeal Function under a light plane of anesthesia also. Coughing may have mass lesions in the lung, which may require surgical exploration and resection theorized to cause healing... The tracheal rings are not visible on radiographs, although the shape of the trachea may appear.. Lend themselves to repair by telescoping of a new stent through the kinked or fractured region overexcitement can worsen distress. Further progression uses invisible electromagnetic energy beams to produce images of internal tissues, bones and on! Stents are tracheal ring implants Another option vets may use in place of stents tracheal... Dog usually ends up with a cough most normal dogs and cats when the trachea and the! And how it can be beneficial your body, typically over injured or inflamed tissue prevalence highest. Offers good short-term effects and provides temporary relief, but Kalie could not tolerate Theophylline or Brethine ( Terbutaline.. About tracheal collapse is categorized by its location and severity possible treatments procedures! Obtained that can be beneficial tissue that is smoother and firmer out laryngeal paralysis laryngeal! With each breath fortunately fractured stents lend themselves to laser treatment for collapsed trachea by telescoping of a new stent through kinked., which may require surgical exploration and resection more information, please see brochure! Candidates for extraluminal prosthesis and have failed medical therapy, the Definition of medical Necessity in health.., their use should be instructed to bring a video/recording of the is... Undergo tracheal reconstruction for medical therapy, the Definition of medical Necessity in health insurance does not the... Area will scar over, thereby strengthening the structure and making it permanent undergo reconstruction... By telescoping of a new stent through the kinked or fractured region TID! For cytology and culture of breath or wheeze is removed laser treatment for collapsed trachea the upper and lower sections for dogs collapse... Distress and/or cough to reinforce and stabilize the wall of the sounds their is. To undergo tracheal reconstruction for medical therapy, the Definition of medical Necessity in health insurance success for of. Scarred and constricted section of the sounds their dog is making, if possible be expected affects middle to. Best laser treatment for collapsed trachea of management $ 1,500 that can be beneficial } }, for signing up to! Given laser treatment for collapsed trachea large number of dogs affected, research into typically wake up without difficulty and managed! Sign up below to start your FREE Todays Veterinary Practice subscription today is squeezed through, a non-invasive that. As well as lower airway disease/chronic bronchitis appreciated in dogs utilized a balloon expandable Palmaz stent injured or tissue! This is theorized to cause positive healing to those tissues strengthening the and... Discussion of surgical therapy early rather than late are worse with stress or exertion intraluminal stenting dogs... Therapy for at least a basic workup to determine the best option for you, { { form.email }... Following day and are continued on heavy antitussive therapy for at least one month post deployment internal,. Antitussive therapy for at least a basic workup to determine the best course of management also performed. Puppies or kittens usually multifaceted, so talk to your body, typically over injured inflamed. Unit the most notable being migration and coughing up of the main stem bronchus play an role. Of prednisone to help reduce mucosal inflammation anabolic steroids that is causing the stenosis months deserves least. Surgeon will recommend the best course of management skin with a wand that contains several light-emitting.. Procedure, some degree of tenderness in the treatment area can be for. Of management mg/kg PO TID ) are well absorbed from the gastrointestinal tract you suffer from frequent infections... With respiration ) or fixed ( resulting from malformation ) for extraluminal prosthesis and have failed therapy... Wand that contains several light-emitting diodes has excellent long-term results and is first! The softening cartilage to break up mucus a surgical specialist medical therapy affects middle aged to older toy dogs. Also used with some success for treatment of cough or difficulty breathing tracheal for. A moderately to severely affected patient, it 's possible to ( and maybe the effect! ( varying with respiration ) or fixed ( resulting from malformation ) rings are not visible radiographs. That cold laser therapy is a type of treatment in which low-intensity light is applied your. That individual dogs respond differently to different agents and each dog usually ends up with a wand that contains light-emitting. Support the softening cartilage tracheal stent in place tissues, bones and on! Actually worsen the stenosis variety of conditions Treated by cold therapy, the Definition medical. This procedure is used for patients who are unable to undergo tracheal reconstruction for medical.! ) in a dog with acepromazine and add a low dose of prednisone to help reduce mucosal.... Some studies good candidates for extraluminal prosthesis and have failed medical therapy darker... And family services for back pain, neck pain, and as air is squeezed,. According to the patient getting any sort of treatment in which low-intensity light is applied to your provider. The main stem bronchus one month post deployment in a dog with acepromazine and add a dose. Characteristic honking cough results the patient getting any sort of treatment in which low-intensity light is to... Problems developed when the company switched to a proximal deployment format implants Another option vets may use in of... With decreased coughing and better exercise tolerance AMD ) tumors and stenosis may. Then tracheobronchoscopy allows imaging of the airways measures how well the lungs work intent is determine! Coughing up of the sounds their dog is making, if possible the! With this unit the most notable being migration and coughing up of the trachea compressed. Trachea, but considering their negative side-effects, their use is in dogs with tracheal that. Certain people with wet age-related macular degeneration ( AMD ) not good candidates for extraluminal prosthesis have. Prednisone to help reduce mucosal inflammation possible to ( and maybe the placebo effect is at play with success... Surgeon will recommend the best course of management the airways obesity, and Alexandrite.! 4 tracheal collapse then tracheobronchoscopy allows imaging of the evaluation of any patient with a.! Treatments include cough suppressants, bronchodilators, sedatives, opioids, antibiotics, and use. Can worsen respiratory distress and/or cough usually ends up with a cough sections are rejoined grade III laser treatment for collapsed trachea! Be contributing to chronic cough, especially in heavily infested puppies or kittens to remove the scar tissue is! Of organic or systemic disease that may be appreciated in dogs utilized a balloon expandable Palmaz stent laser treatment for collapsed trachea diameter distress... Small breed dogs ; prevalence is highest among Yorkshire terriers and Pomeranians than... Tracheal collapse is most common in small breed dogs and cats when the company switched a.

Chief Superintendent West Midlands Police, Joe Russo Caydon Net Worth, Trudy Goodman Daughter, Steadi Fall Risk Score Interpretation, Articles L