Overview of Transversus Thoracic Muscle Plane Block (TTMPB)
The transversus thoracic muscle plane block (TTMPB) is a type of nerve block – a procedure to numb a specific area – that has become more popular recently. It’s typically used after surgeries involving the chest and heart, especially those needing an incision in the sternum (breastbone) region, to help relieve pain in the front part of the chest.
TTMPB, along with other types of thoracic fascial plane blocks, are being used more and more for quick recovery after chest and heart surgeries. Research has shown that these blocks can notably cut down the time until a patient can be taken off a ventilator and can decrease the occurrence of both severe short-term and long-term pain after surgery.
Anatomy and Physiology of Transversus Thoracic Muscle Plane Block (TTMPB)
The sternum, or breastbone, receives sensations through nerves known as the intercostal nerves. These originate from the spinal nerves in the chest area, specifically those between the second and sixth vertebrae of the thorax.
When it comes to the muscles, the front part of our chest is made up of different muscle groups. These include the external, internal, and innermost intercostal muscles, the transversus thoracis muscles, and the subcostales muscles. Among these, the transversus thoracis is a thin muscle that’s in the same layer as the innermost intercostal and subcostal muscles. These muscles act as a separator between the chest wall and the outer lining of the lungs, also known as the parietal pleura.
The transversus thoracis attaches to the bottom backside of the sternum, all the way down to the xiphoid process, which is the lowermost part of the sternum. It then spreads across the chest and attaches itself to the rib cage, typically to the second through sixth ribs.
A form of pain management called the TTMPB is designed to offer pain relief to these same corresponding areas of the chest. It’s interesting to note that the attachments of these muscles can vary from person to person and even between the left and right sides of the same person’s body.
The transversus thoracis helps in forced exhalation, meaning it helps you push air out of your lungs when you’re breathing out strongly. Another important part of this area is the internal thoracic artery, which is commonly used during bypass surgery for coronary artery disease. This artery typically runs in front of the transversus thoracis muscle.
Why do People Need Transversus Thoracic Muscle Plane Block (TTMPB)
The TTMPB, or Thoracic Transverse Musculocutaneous Pectoral Block, is a medical procedure often used in surgeries where the breastbone, also known as the sternum, needs to be cut into. This technique is particularly useful in heart surgeries where a cut into the sternum (median sternotomy) is usually made. This method was first explained in detail by a group of medical experts led by Ueshima in 2015. Since then, many studies have confirmed its usefulness in heart-related surgeries.
While it is especially beneficial for managing pain during and after a surgery involving a sternotomy, the TTMPB can be used for any surgery that needs pain relief in the front part of the upper body, defined by the T2-T6 dermatomes. In simpler terms, this includes multiple chest and breast surgeries, as well as comparatively minor procedures like the placement of a subcutaneous implantable cardioverter-defibrillator (S-ICD), a device planted under the skin to monitor and regulate heart rhythms. The TTMPB can also be combined with a pectoralis (PECS) nerve block for better results in certain cases.
It’s important to note that the TTMPB is not just limited to surgeries. It can be used for patients who have fractures in their sternum and has been proved as a good option for relieving pain in these situations.
When a Person Should Avoid Transversus Thoracic Muscle Plane Block (TTMPB)
There could be reasons why a patient cannot go through TTMPB (a type of regional nerve block procedure) which are common to other similar procedures. Some of these are:
- The patient doesn’t want to do it.
- The patient is allergic to the local anesthetics (medication that numbs a specific area).
- There is an infection or tumor at the place where the injection is supposed to be given.
In addition to these, special care needs to be taken for patients having liver problems. This is because the local amide anesthetic, a type of numbing medication, gets processed in the liver. Using such a medication in these patients could lead to a condition called Local Anesthetic Systemic Toxicity (LAST). This condition can result in neurological symptoms like numbness around the mouth, altered mental status and seizures. In severe cases, it can cause cardiac arrest or even death.
Further, performing the TTMPB procedure could potentially result in a pneumothorax, a condition where air gets into the space between the chest wall and the lung. This can pose a serious risk, especially for patients with compromised lung function where the development of pneumothorax can be particularly harmful.
Lastly, even if TTMPB is not a neuraxial technique (related to the spinal cord), doctors should also consider if a patient has a blood clotting disorder, known as coagulopathy, before performing a TTMPB. This procedure could be considered a deep nerve block in a non-compressible fascial space (an area where pressure cannot be applied to stop bleeding), so if any blood vessels are accidentally damaged, controlling the bleeding could be challenging.
Equipment used for Transversus Thoracic Muscle Plane Block (TTMPB)
A TTMPB is a procedure carried out with the help of an ultrasound, which helps reduce the chance of any issues happening during the process. Let’s break down what’s required to perform the block:
- An ultrasound machine with a special kind of scanner, known as a high-frequency linear transducer
- Sterile gloves
- A clean cover for the ultrasound and gel
- Chlorhexidine or another type of antiseptic to clean the skin
- A specific type of needle used for nerve blocks, usually around 80 mm to 100 mm long
- Two syringes (if the procedure is being done on both sides of the body), each filled with 20 to 30 mL of local anesthetic plus possibly some other drugs to aid in pain relief
- A local anesthetic, usually a long-lasting type like bupivacaine or ropivacaine
- Residents – Various types of vital sign monitors, including a pulse oximeter to measure blood oxygen levels, a blood pressure monitor, and an electrocardiogram to keep an eye on the heart’s electrical activity.
Who is needed to perform Transversus Thoracic Muscle Plane Block (TTMPB)?
The TTMPB, a type of anesthesia, should be done by a person trained in giving regional anesthesia, one who performs similar procedures often. This person is usually an anesthesiologist, a doctor specializing in relieving pain during surgeries. Before starting the process, another medical professional or a nurse needs to conduct a ‘universal timeout’ or similar routine. This simply means they pause to double-check everything is in order before the procedure begins.
This helper would also work alongside the anesthesiologist during the procedure, handling the local anesthetic solution that numbs the area. They will inject this solution when the anesthesiologist, using ultrasound imaging as their guide, signals that they’ve reached the correct layer of tissue with the needle. Ultrasound helps them visualize the body parts under the skin, making the procedure safer and more accurate.
Preparing for Transversus Thoracic Muscle Plane Block (TTMPB)
Before receiving regional anesthesia, a type of local anesthesia that blocks pain in a larger area of your body, your doctor would review your past health and surgical records. They will check your blood clotting status and ask if you’re taking any blood-thinning medicines. It’s crucial to have a conversation with your doctor about the procedure’s risks, benefits, and other options. You should fully understand and give consent before proceeding.
You should be connected to standard monitoring equipment during the procedure, including a device to check your blood pressure, a pulse oximeter to measure your oxygen saturation, and an electrocardiogram to monitor your heart rate. If you’re awake during the procedure, anxiety-relief medication or local anesthesia to numb the skin and tissues under the skin may be given to increase your comfort.
It’s also crucial to confirm the patient’s details and the surgical site before starting the procedure. This involves a “time-out” where your name, birth date, and the location and side of your body where the procedure will be performed, are verified by you, your doctor and a nurse or other healthcare provider. The procedure will only proceed when everybody agrees that the information matches.
How is Transversus Thoracic Muscle Plane Block (TTMPB) performed
The TTMPB is a medical procedure usually carried out at the area corresponding to the 4th and 5th spinal bones in your abdomen. During this procedure, your doctor will first prepare a solution that will numb the area where the procedure is to be done. Your skin is then carefully cleaned with a disinfectant to prevent infections.
After wearing all the necessary protective equipment, your doctor will use a sterile cover for the ultrasound device which helps to see the area they will be working on. This device is placed about a centimeter away from the middle of your chest. The area between the 4th and 5th ribs is then located using the ultrasound. The needle used for the procedure is then placed in that specific area using the help of the ultrasound.
The needle will then be moved into a layer of muscles in your chest, specifically between the transversus thoracis and the internal intercostal muscles. The numbing solution is then carefully injected into this area. It is a one-time injection, done in small amounts each time, and your doctor will be careful to draw back the needle before each injection, to make sure they aren’t injecting into a blood vessel or within the layers of the lung. A successful injection will be seen as a downward movement of the layer lining the lungs.
The TTMPB has been done in different ways and at different sites, but it’s usually carried out between the 4th and 5th ribs, with proof from both previous similar procedures and research on bodies donated for scientific study. These studies showed that the numbing solution effectively spreads within the chest area from the breastbone.
The idea of a numbing block near the breastbone, which numbs the same nerves and skin areas as the TTMPB has been written about in medical literature since as early as 2005.
Possible Complications of Transversus Thoracic Muscle Plane Block (TTMPB)
Complications related to a specific medical procedure known as TTMPB are quite rare. Generally, problems that can occur during or after anesthetic blocks include too much bleeding at the site where the needle was inserted, an infection developing at the site of the injection, damage to the nerves or blood vessels, and a syndrome called LAST which affects the brain and heart due to the high dose of local anesthetic.
In the TTMPB procedure, particular risks exist because of the surrounding body structures. Since the muscle nearest to the chest cavity (the transversus thoracis muscle) is close to a layer of the chest called the pleura, if the needle accidentally punctures this, it can cause a condition called pneumothorax, where air leaks into the space between the lung and chest wall. Also, the major blood vessel in the chest (the internal thoracic artery) and the sac surrounding the heart (the pericardium) are close to this area, so poor needle placement might damage these and lead to complications such as a blood-filled chest cavity (hemothorax) or blood around the heart (hemopericardium).
Using a technique called color wave doppler, doctors can get a visual of the internal thoracic artery, which lies in the same area as the transversus thoracis muscle. This helps guide their needle placement for safety.
What Else Should I Know About Transversus Thoracic Muscle Plane Block (TTMPB)?
As people worldwide are living longer, the demand for surgery is growing. This growth includes cardiothoracic surgery, which refers to surgeries involving the heart and lungs. There’s a need to improve pain relief during and after these surgeries because such procedures can often lead to unmanaged pain and the development of chronic pain conditions. One primary concern is managing pain safely, especially for patients who are taking blood thinners during surgery.
In this context, new techniques such as ‘fascial plane blocks,’ or TTMPB, are being used more often. They can provide pain relief without the risk associated with other methods and can generally be safely performed even if the patient is on blood thinners.
Pain after cardiothoracic surgery is a complex issue. It can include pain not just in the chest but also in the head, neck, upper body and back. Poorly managed post-surgery pain can lead to severe complications like heart problems and excessive bleeding. Uncontrolled persistent pain can also affect breathing, potentially requiring re-insertion of the breathing tube.
Historically, doctors often prescribed opioids (painkilling drugs) after surgery. Unfortunately, too many opioids can slow down recovery and even worsen the pain, leading to a condition known as opioid hyperalgesia. Surprisingly, inadequately treated pain may result in similar complications.
In such cases, TTMPBs and similar techniques are being increasingly used to lessen these issues following cardiothoracic surgery. TTMPB use has even allowed for some minimally invasive procedures to be done with little to no sedation.
Research shows TTMPB can reduce the need for opioids after surgery, which minimizes side effects like post-surgery nausea. TTMPB use has reduced pain after surgery, where patients needed less pain medication and felt less pain overall. These nerve blocks have lessened the time patients need lung machines to breathe for them after surgery and reduced their stay in intensive care units.
There’s strong evidence to support their use in children undergoing heart surgery, where TTMPBs shortened their time on a ventilator and brought down the levels of pain and the use of opioids.
This technique also decreases chronic pain caused by open heart or lung surgery and has been beneficial for patients living with lasting pain from surgical incisions.
In conclusion, TTMPBs are a promising tool for managing pain after cardiothoracic surgery. They can help in quicker recovery, reduce both immediate and lasting pain, and serve as a safe alternative to traditional pain management methods when these are not appropriate.
