Overview of Tracheal Reconstruction
Tracheal abnormalities, which require restructuring, are rare but can affect people of all ages. Tracheal stenosis, a condition where the trachea (the windpipe that carries air to the lungs) is narrow, makes up 1% of all such abnormalities related to the voice box and trachea. However, this condition can result in a fatality rate of 20 to 30% and can rise to 70% when it appears in the first month of a baby’s life.
Tracheal anomalies typically fall into two categories: congenital and acquired. Congenital lesions are present at birth and often come with other abnormalities. Up to 50% of patients have related heart and lung abnormalities. On the other hand, acquired tracheal stenosis can happen from various factors and is frequently a result of prolonged intubation (putting a tube down the throat), leading to injury of the trachea’s lining.
According to Poiseuille’s law, the flow of air is directly proportional to the to the fourth power of the radius of the trachea. This means that even a slight decrease in the size of the trachea can affect airflow significantly. Young children are at increased risk of having serious airway problems due to the small size of their trachea. Their trachea can be as small as 4 to 7 millimeters in diameter, and it does not reach 1 centimeter in diameter until around the age of 8. Therefore, children are less able to tolerate narrowing of the airway and often require surgery.
Congenital tracheal stenosis can emerge from abnormal formation in the womb, resulting in various abnormalities that are often associated with genetic changes or syndromes. Some of these include conditions like tracheomalacia (weak windpipe), complete tracheal rings (rings around the trachea), tracheal cartilaginous sleeve (entirely cartilaginous trachea), fistula (abnormal connection) between the trachea and esophagus, absence of the trachea and external compression due to veins and ligaments.
Acquired abnormalities can occur in both children and adults. These are often the result of medical procedures, but can also include injuries from intubation and high cuff pressure (pressure-induced ischemic necrosis), complications from tracheotomy tubes, inflammatory or infectious conditions, trauma, inhalation injury and both benign and malignant tumors.
Upon detecting tracheal stenosis, it is vital to accurately classify its severity. This classification generally separates it into long-segment (over a large area) or short-segment (over a small area) narrowing. Also, whether the narrowing is within the chest cavity or outside of it (above the breastbone) greatly alters surgical approaches and factors to consider during anesthesia.
Moreover, it’s essential to measure the extent of the narrowing of the airway. The original Cotton-Meyer scale, initially introduced for measuring stenosis under the voice box, is used to grade tracheal stenosis. The grades are based on the percentage of narrowing in the airway, with Grade I being 0 to 50%, Grade II 51 to 70%, Grade III 71 to 99%, and Grade IV where no airway can be detected.
Anatomy and Physiology of Tracheal Reconstruction
The trachea, also known as your windpipe, starts from the lower part of your voice box (specifically, from an area called the cricoid cartilage) and goes all the way down to a place called the carina, which is where it splits into your two bronchi that lead to your lungs. The trachea forms early during development in the womb, where it grows from a structure known as the laryngotracheal bud.
The trachea is important in separating the structures of the throat and esophagus, which is the tube that leads to the stomach. A newborn baby’s trachea usually has a diameter of about 4 to 7 millimeters and is about 4 centimeters long. For adults, the diameter of the trachea can range from 12 to 25 millimeters, and it can be as long as 13 centimeters.
The trachea has a very interesting structure. It’s made of stacked rings of cartilage that are shaped like a “C”. These sturdy cartilage rings keep the trachea from collapsing and allow it to expand when we breathe. The back part of these rings are not cartilage but muscle, which gives it flexibility. There are typically around 16 to 20 of these rings in the trachea.
If a part of the trachea needs to be reconstructed because of disease or injury (like in certain types of surgeries), doctors need to consider several factors. The trachea receives its blood supply from arteries that come from the neck and the bronchi. Preserving these arteries is very important during a surgery. Equally important is understanding how the trachea is connected to the surrounding structures. For instance, the trachea is located next to the esophagus and nerves that control your voice box, which run on either side of the trachea.
The thyroid gland, which is a butterfly-shaped gland located in the front of the neck, is also attached to the trachea. Furthermore, inside the chest cavity, the trachea is surrounded by the lungs and blood vessels that go in and out of the heart. When it comes to complex surgeries like this, it’s key that the doctors involved come from various specialties.
Why do People Need Tracheal Reconstruction
When a patient has symptoms relating to tracheal stenosis, which is a narrowing of the windpipe, they often need surgery to fix it. The type of treatment considered relies on judging the severity of the condition using the Cotton-Myer grading system, and recognizing if it’s a short-segment tracheal stenosis (SSTS), which affects a small portion of the trachea, or long-segment tracheal stenosis (LSTS), which impacts a more considerable portion of the windpipe. Patients usually have three treatment choices: watching and waiting with gentle care, endoscopic surgical repair (which is less invasive and done with a tube), and open surgical repair (which is more invasive). What treatment is best can depend on a number of factors:
If a patient is carefully observed without immediate surgery, this could be due to them being unsuitable for surgery, needing a ventilator because of lung disease, having a milder form of the disease that isn’t causing symptoms, or if the patient is a child who is still growing.
A less invasive surgical fix using an endoscope, which is a long, flexible tube with a camera and light at the end, could be used if a patient has mild to moderate symptoms. This is also the suggested method if the scar tissue causing the narrowing is thin, if fewer than one or two tracheal rings are affected, or as additional steps following an open repair.
A more extensive, open surgery may be needed if either SSTS or LSTS is present, if the less invasive repairs were not successful, if the tracheal narrowing involves complete rings of the trachea, or if there are other heart or lung problems that also need fixing.
When a Person Should Avoid Tracheal Reconstruction
It’s important to consider various factors before deciding to go for a tracheal reconstruction surgery. The patient’s overall health is the first point of consideration, as even a successful surgery might still necessitate a tracheostomy tube (a tube inserted in the neck to aid breathing) and breathing support in some cases. It’s essential that the patient, their family, and the surgical team understand and agree on the aims of the surgery and the expected outcomes.
It’s also crucial to evaluate whether the patient is healthy enough to tolerate the surgical procedure. If there’s doubt about their fitness for surgery, it might be safer to continue monitoring the patient instead of performing reconstruction. Conditions leading to narrowing of the voice-box, or laryngeal stenosis, need to be addressed before or in conjunction with tracheal reconstruction in selected patients.
The patient shouldn’t have any severe lung dysfunction and inflammation of the airways due to underlying lung or stomach-related conditions should be treated before surgery to ensure that the body heals well after the surgery. Conditions that interfere with the body’s natural ability to heal, such as an ongoing infection, diabetes, a history of radiation therapy, steroid use, or inflammatory conditions could also be a reason to avoid surgery.
Equipment used for Tracheal Reconstruction
To perform the necessary procedures, the doctor will use the following tools:
1. Laryngoscopy/bronchoscopy set: This includes a small tube-like instrument with a light at the end to help the doctor have a closer look at your larynx (your voice box) and bronchial tubes (connect your windpipe to your lungs).
2. Suspension laryngoscopy set: This is a set of specialized tools used to hold the larynx open for clear viewing and examination.
3. Microlaryngeal instrument set: These are tiny precision instruments used for surgery or treatment of the larynx.
4. Endoscopes and tower: Endoscopes are long, thin, flexible tubes with a light and camera at the end, to help the doctor clearly see the inside of your body. The tower is the stationary unit that supplies light and captures the images.
5. Airway LASER (typically CO2): A precise surgical tool that uses light energy to cut or remove tissue.
6. Endoscopic airway balloons: These are balloons that can be inflated inside the airway to clear obstructions. The size of the balloon is typically 2 mm larger than the tube that would be used for your age.
7. Head and neck soft tissue set: This contains various instruments meant for operating on the soft tissues of the head and neck.
8. Tracheotomy set: These are tools needed to perform a tracheotomy, a procedure where a hole is made in the windpipe to assist with breathing.
Who is needed to perform Tracheal Reconstruction?
For children going through surgery (especially those with various health issues), it’s essential to have a team of different healthcare experts ready to support them before and after the surgery. This team includes ear, nose, and throat specialists, heart and lung surgeons, lung doctors, digestive system doctors, intensive care doctors, anesthesiologists (who are responsible for making sure you’re not awake or in pain during the surgery), speech and language therapists, and health coordinators.
It’s crucial for these children to receive care in a special clinic called an aerodigestive clinic, which focuses specifically on children’s needs. This clinic promotes teamwork and effective communication among the doctors and healthcare personnel, ensuring quicker care, fewer risks, and less chance of complications. This way, everyone works together to help the child recover faster and more safely.
Preparing for Tracheal Reconstruction
If a person is going to have surgery on their airways, the doctor will first confirm the thickness and seriousness of the narrowing area, known as stenosis, in their airways. He or she uses special tools to look directly into the person’s throat or uses a tube to visualize the lungs, in a procedure performed by an ear, nose, and throat specialist (Otolaryngologist). In addition to this, the doctor often works with other specialists in matters related to stomach and lung health to make sure the entire breathing and digestion system (aerodigestive tract) is healthy.
If the person’s health allows them to have the surgery, their doctor will usually get some images of the inside of their body to help plan the surgery and confirm their findings. These images are often got from a special kind of X-ray scan that uses a computer to make detailed pictures of areas inside the body, called a high-resolution CT scan, with contrast of the neck and chest. The scan will show the narrowed part of the airway and any abnormal shapes that need to be addressed. Depending on the cause and nature of the abnormal shape, the doctor might also use pictures made by a CT angiogram (a type of X-ray that looks at blood vessels) and an MRI (a test that uses powerful magnets and radio waves to make pictures of organs and structures inside the body).
Many hospitals and clinics are starting to use 3-D printing and rapid prototyping technology to help plan and carry out operations. They use the images from a person’s high-resolution CT scan to make patient-specific 3-D models that allow the surgical team to better understand the stenosis and test out their ideas and techniques before the surgery. This boosts their confidence during the surgery. There have also been cases where patient-specific implants that dissolve on their own over time have been used to treat difficult narrowing in the main airways leading to the lungs (tracheobronchial stenosis) with promising results. Many people believe that in the future 3-D printing will allow for patient-specific printed replacements (grafts).
How is Tracheal Reconstruction performed
For those with tracheal stenosis (a narrowing of the windpipe), different procedures can be conducted based on the severity and location of the condition. Your specialists like an Otolaryngologist (an ear, nose, and throat doctor), along with other professionals, will choose the best approach for you. It’s highly important they understand your specific condition thoroughly, which may sometimes require input from a Cardiopulmonary specialist. If your condition is a bit complex, it may need an extra procedure called the sternotomy (a surgical operation by which the chest is opened).
Endoscopic Repair
This procedure involves inserting a tube with a camera into your throat to visually guide the surgical instruments. Your surgeon will inform your anesthesiologist (specialist responsible for pain management during surgery) about inserting the balloon into your windpipe, which might affect your oxygen levels. This method might also use heat or laser to cut or burn away the narrowed part of the trachea, which could increase the risk of fire. Thus, certain precautions are needed.
To ensure you’re comfortable during the procedure, you will be given intravenous (IV) steroids, and a local anesthesia will likely be put in your throat. Using specialized instruments, your surgeon makes a careful incision through the stenosis (narrowed part of the trachea) and places a balloon into the windpipe. Once placed properly, the balloon is inflated and keeps the narrowed part open. The inflation time is determined by your anesthesiologist. This procedure might have to be repeated depending on your condition.
Tracheal Resection and Reanastomosis
This approach is done often for complex stenosis and general anesthesia with a breathing tube can be used. If the problem area is found in the lower part of the body, it may require a process known as cardiopulmonary bypass.
Firstly, the blocked section of your windpipe is exposed while preventing harm to surrounding structures. The area of blockage is then removed with the help of a visualization method and the free ends of the trachea are joined together after the removal, ensuring there’s no tension. Post-surgery, you might be sedated for a short period of time to ensure proper healing.
Slide Tracheoplasty
This has become the preferred method for complex stenosis. It involves widening the narrowed segment while preserving as much of the trachea as possible. Because of the location of the blockage, it often requires a sternotomy for better exposure. Depending on the patient’s condition, cardiopulmonary bypass might also be required.
Closure proceeds in a water-tight, tension-free function. After a leak test, the chest is closed. Lastly, to make sure the trachea heals well post-surgery, you must avoid neck extension which can be achieved with sedation or chin-to-chest sutures.
Your doctors having open communication and understanding your individual case will guide them in choosing the most suitable techniques for your treatment.
Possible Complications of Tracheal Reconstruction
Tracheal reconstruction is a surgery that can often be successful; however, there’s about a 40% chance that some complications may arise. Spotting and taking care of these issues early helps ensure good long-term results. Apart from the complications you would expect with any kind of surgery, there are particular complications that might happen after tracheal reconstruction. These can be grouped into three categories.
The first kind of complications are known as anastomotic complications. These include granulation tissue, which is new connective tissue that forms on the surface of a wound during the healing process; restenosis or stricture, which is a narrowing that can occur in the trachea; tracheomalacia, a condition that causes the windpipe to collapse; leaks; and dehiscence, which happens when a wound splits open.
The second type of complications are fistulas, which are abnormal connections between the trachea and neighbouring structures. These can be tracheoinnominate, where a connection forms between the trachea and a large artery in the neck; tracheoesophageal, where a connection forms between the trachea and oesophagus; and tracheocutaneous, a connection between the trachea and the skin.
The third group includes miscellaneous complications, such as recurring injury to the nerve near the larynx, swallowing trouble or food accidentally entering the airway (dysphagia/aspiration), inflammation of the middle part of the chest (mediastinitis), air in the chest cavity (pneumomediastinum or pneumothorax), needing to use a ventilator for longer than expected, or, in very rare cases, death.
What Else Should I Know About Tracheal Reconstruction?
Tracheal stenosis is a rare health issue where your windpipe (trachea) becomes narrower than normal. This can happen because of birth defects or damage to the windpipe. The most common reasons for such damage can be long-term use of breathing tubes (prolonged intubation) and high pressure inside these tubes (high cuff pressure), resulting in a narrowed windpipe.
This condition can be very serious, especially for children, and could potentially lead to death if not identified and treated early. To successfully and correctly manage these patients, doctors categorize the severity of the condition which in turn guides the treatment approach.
It’s crucial that doctors and patients have a clear understanding of the treatment goals. After that, there are various surgical options to fix the narrowed windpipe through an endoscope (a thin tube with a camera) or using a traditional open surgery. These surgeries have generally been successful in treating this condition.
However, like with any surgeries, there can be complications, and these should be addressed quickly to prevent any unwanted results. This is why it’s important for the medical team and patient to communicate well, ensuring everyone is on the same page before, during, and after treatment.
