Overview of Segmental Lung Resection
Lung cancer is the second most common type of cancer found in men and women in the United States. What’s more, it causes more deaths than any other cancer around the world. One of the main ways to treat lung cancer is by doing surgery to take out all or part of the lung that’s diseased.
In the early days of these types of surgeries, doctors didn’t have the advanced types of anesthesia (medicine to make you asleep or numb) that we have now, so these procedures weren’t always easy. Sometimes this meant that doctors accidentally removed some healthy lung tissue during the surgery. The original method was a pneumonectomy, which is a medical term for the removal of a whole lung. But since this method had high rates of other diseases and deaths related to the surgery, doctors started to develop procedures that were less extreme.
In 1962, a study by a researcher named Shimkin showed that doing a lobectomy, which is the removal of just a section or “lobe” of the lung, could be just as effective as a pneumonectomy when it came to helping patients survive. But it also had lower rates of additional diseases and problems caused by the surgery. So it became the preferred method for removing lung cancer.
Then in 1995, a study by a group called the North American Lung Cancer Study Group found that doing a sublobar resection – which is the removal of an even smaller part of the lung – led to more cancers coming back and worse outcomes overall. Because of these findings, this technique is usually only used for patients who wouldn’t be able to tolerate a lobectomy. But doctors are still interested in this method, especially in light of new advancements in chest surgery since the time of this study.
In 1973, a process called segmentectomy was described by Jensik. A segmentectomy is a surgery where a doctor takes out a specific part or “segment” of the lung. Even now, physicians are researching how segmentectomy could fit into lung cancer treatments.
Anatomy and Physiology of Segmental Lung Resection
The right lung is made up of three sections, known as lobes: upper, middle, and lower. The left lung has two lobes: upper and lower. The lungs are divided into 10 segments each; these are determined by their connected bronchi (airways leading to the lungs) and blood supply. Each segment has its own code for its bronchial, arterial, and venous anatomy, represented as B#, A#, and V# respectively.
The upper lobe of the right lung has three segments: the apical, posterior, and anterior. These segments can be removed individually or together during surgery. The middle lobe has two segments: the lateral and the medial. It’s uncommon to remove individual middle lobe segments. The lower lobe of the right lung also has two main segments: the superior and the basilar. The basilar segment is further divided into four subsegments. Removing individual basilar subsegments can be complex and is not frequently done; instead, the entire basilar segment is often removed.
The left lung’s upper lobe is divided into two main segments: the apicoposterior and anterior. There is also a lingular segment that corresponds to the right middle lobe, divided into superior and inferior segments. It’s common to perform segment removing procedures in the left upper lobe. The lower lobe of the left lung has two main segments: the superior and the basilar, with the later divided into three subsegments. It’s common for surgical procedures to involve the removal of the entire superior or basilar segments instead of individual subsegments.
In the mediastinum (the area between the lungs), there are lymph nodes that are crucial for diagnosing and treating lung cancer. These are identified by numbers and are sorted by their locations. Some of the lymph nodes are in the superior (upper) mediastinum, including highest mediastinal nodes, upper paratracheal nodes, prevascular and retrotracheal nodes, and lower paratracheal nodes. In the aortic nodes, there are subaortic (aortopulmonary window) nodes and paraaortic nodes. In the inferior (lower) mediastinum, the nodes include subcarinal nodes, paraesophageal nodes (below carina), and pulmonary ligament nodes.
Additionally, there are nodes inside and around the lungs called N1 nodes, including hilar nodes, interlobar nodes, lobar nodes, segmental nodes, and subsegmental nodes. N2 nodes are located outside the lung tissue but within the central chest area. They are classified further according to their specific locations in the mediastinum. N3 nodes, which indicate a more advanced stage of lymph node involvement in lung cancer, are located further away from the primary tumor than N1 and N2 nodes.
Why do People Need Segmental Lung Resection
Anatomic segmental resection can be used in the treatment of several conditions, both malignant and benign. This procedure essentially involves removing part of an organ where the disease is located. Here are some examples:
Malignant Conditions
In specific patients with a form of lung cancer called non-small cell lung cancer, segmental resection can be an appropriate treatment. The National Comprehensive Cancer Network recommends this treatment for patients who have a poor lung capacity or other conditions that would make a full lobectomy (removal of a lung lobe) risky. Additionally, it is recommended for patients with peripheral nodules (small growths) that are made of pure adenocarcinoma and:
- are less than or equal to 2 cm in size,
- appear more than 50% as ground glass (hazy, non-solid) on a CT scan, and
- takes a long time to grow, as confirmed by radiologic surveillance.
In these cases, the removed portion should be at least 2 cm and include appropriate lymph node stations (N1 and N2). This is where cancer could spread.
Metastatic Conditions
Segmental resection can also assist in treating lung metastases (cancer that has spread from another part of the body to the lung). This procedure has shown to help improve survival in colon cancer, for instance. The resection may involve removing single or multiple lesions (abnormal tissue) to preserve as much healthy lung as possible.
Benign Conditions
Segmental resection can also be used in treating various non-cancerous conditions, including:
- Congenital deformities such as bronchial atresia (blockage of the airway), bronchiectasis (widening of the bronchial tubes), arterial malformations, and sequestrations (an isolated part of the lung that does not function normally),
- Infections like aspergilloma (fungal infection in the lung) and non-tuberculosis mycobacterium, and
- Other lung diseases such as bronchiectasis and inflammatory pseudotumors (abnormal growth that resembles a tumor but isn’t cancerous).
When a Person Should Avoid Segmental Lung Resection
Segmental sublobar resection, a surgery that only removes a small part of the lung, is generally not considered sufficient treatment for patients who can handle a lobectomy, where a whole lobe of the lung is removed. Additionally, no studies have been done to see if this less invasive surgery works for patients with small-cell lung cancer. Certain barriers to the procedure also exist, like severe emphysema (a lung condition that causes shortness of breath), interstitial pneumonia (a type of lung disease), and having had many previous surgeries that have caused the tissues to stick together. These conditions can make it too difficult to carry out the operation.
Equipment used for Segmental Lung Resection
The type of equipment your doctor needs for your surgery will depend on the type of surgery they’re performing. No matter the type of surgery, there are common tools they’ll need. This includes basic surgical tools, devices used to cut and control bleeding, and materials for closing up the wound like stitches, staples, and bandages. They’ll also need tubes to drain fluid from your chest.
If you’re having an open surgery, the specific tools your doctor will need are:
- A double-lumen endotracheal tube: this is a special type of breathing tube.
- An airplane splint for the arm: a device used to hold your arm in the correct position during the surgery.
- A rib spreader: a tool to separate your ribs to gain access to your chest.
- Various stapling tools: these are used for different purposes, like closing up the wound.
If your doctor is using a method called video-assisted thoracoscopic surgery (VATS), they will need:
- A double-lumen endotracheal tube and airplane splint for your arm, just like in open surgery.
- A video system with screens, lighting, and a scope: this equipment lets your doctor see inside your chest without having to make a large cut.
- Endoscopic tools: these are special instruments that can be used through small cuts in your skin.
If your surgery involves a robot, your doctor will need similar tools as in the VATS method. In addition, they’ll need the robot and special instruments that the robot can use.
Who is needed to perform Segmental Lung Resection?
Every patient’s condition should be reviewed by a multidisciplinary team of medical experts specialized in different aspects of care to decide on the best treatment plan. This team should include specialists in cancer treatment (oncology), disease diagnosis (pathology), lung diseases (pulmonology), cancer treatment using radiation (radiation therapy), and lung surgery (thoracic surgery). The surgeon, who is trained specifically in treating lung cancer, will perform an operation if necessary to remove a section of the lung (called a ‘segmental lung resection’).
In the operating room, the surgeon will be joined by a team of other medical professionals who provide additional support. This includes another surgeon to assist, an anesthesiologist experienced in one-lung breathing (a method used during lung surgeries), a scrub nurse who knows the specific procedures used in lung surgery, and a circulating nurse who is familiar with the surgical tools used in lung operations. This team makes sure that every step of the surgery goes smoothly, ensuring the best possible outcome for the patient.
Preparing for Segmental Lung Resection
Programs that screen for lung cancer are very important because they help identify people who are at high risk and monitor them closely. This way, if lung cancer is detected, it is often caught at a stage where it can still be cured. Right now, the U.S. Preventive Services Task Force advises that adults between the ages of 55 and 80 who have a history of smoking (defined as 30 pack-years) and either are still smoking or stopped within the last 15 years should get a special type of low radiation CT scan every year. There is a conversation about whether to start these screenings at age 50 and include those with only 20 pack-year smoking history.
If doctors think a patient might have lung cancer (or if a sample of their tissue, called a biopsy, proves they do), it’s essential to figure out what stage the cancer is in. To do this, they will typically perform a variety of tests, including a chest and abdomen CT scan (which uses x-rays to create detailed images of the body), counseling on quitting smoking, breathing tests, possibly a bronchoscopy (an examination of the airways using a flexible tube passed down the throat), a PET-CT scan (which shows how the tissues and organs are functioning), and they might also look at the lymph nodes to see if the cancer has spread there. Once doctors decide that lung surgery is needed, they will do additional tests to make sure the patient’s lungs and heart are strong enough for surgery.
How is Segmental Lung Resection performed
A thoracotomy is a type of surgical procedure where doctors make a large incision in the chest to gain access to the heart, lungs, esophagus, and other organs in the chest. There are three approaches to doing this: the open thoracotomy approach, the VATS approach, and the robotic-assisted VATS approach.
In the open thoracotomy approach, you are positioned on your side with your chest stretched out. The surgeon makes a large incision on your side and uses instruments known as rib-spreaders to give them a clear view of the inside of your chest. They often use a method called single-lung ventilation, which means they ‘turn off’ one lung to make the surgery easier. The surgeon carefully cuts away and removes any unhealthy tissue.
In the VATS (Video-Assisted Thoracoscopic Surgery) approach, the setup is similar to the open approach as you’re still on your side with your chest extended. However, instead of making a large incision, the surgeon makes a small one (3-4 cm) on your side. They then insert a thin tube with a camera and light on the end, known as a thoracoscope, into this incision. This gives the surgeon a clear internal view without needing to make a large cut. They also insert other surgical tools through this small hole. The surgeon is then able to operate by watching what they’re doing on a video screen.
The robotic-assisted VATS approach also involves small incisions but uses a surgeon-controlled robot to perform the operation. The robotic system allows the surgeon to move with more precision and control. This type of surgery can result in less pain after surgery and a shorter hospital stay. However, it requires advanced training for the surgeon and specialized equipment.
Your doctor will decide which approach is best for you based on your individual situation and their expertise.
Possible Complications of Segmental Lung Resection
Early Complications
Complications that happen within 30 days after surgery are termed “early complications.” These are usually managed in a hospital with close observation, additional treatment if needed, and care to make recovery comfortable. Some common complications include:
* Fluid build-up in the lungs (Pulmonary edema)
* Lung infection (Pneumonia)
* Severe lung condition that affects oxygen flow (Adult respiratory distress syndrome)
* Breakdown of repair site in the lungs (Bronchial dehiscence)
* Abnormal connection between the bronchus and pleural cavity (Bronchopleural fistula)
* Twisting of a lung lobe (Lobar torsion)
* Collection of blood in the space between the chest wall and lung (Hemothorax)
* Collection of lymphatic fluid in the space between the chest wall and lung (Chylothorax)
Late Complications
Complications that happen 30 days or more after surgery are termed “late complications.” These are often managed outside the hospital with regular check-ups, additional treatment if necessary, and continued care to improve the patient’s comfort and normal body function. Some of these complications include:
* Narrowing of the bronchus, the main airway into the lung (Bronchial stenosis)
* Pus build-up in the pleural cavity, the area between the lungs and chest wall (Empyema)
* Series of symptoms that occur after removal of a lung (Postpneumonectomy syndrome)
* Blood clot in the stump of the remaining lung tissue (Stump thrombus)
* Unnatural connection between the esophagus and pleural cavity (Esophagopleural fistula)
Significantly, if a part of the lung (called a segment) is removed, there is a higher chance of cancer coming back and the lymph nodes (small glands that are part of your immune system) not being adequately inspected. This is important information that patients considering this type of lung surgery need to be aware of.
What Else Should I Know About Segmental Lung Resection?
Lung cancer is the second most common type of cancer in American men and women and it’s also the most deadly. Usually, the recommended treatment for most stages of this disease is a surgical procedure known as lobectomy, which involves removing a section of the lung.
However, some patients may find it difficult to cope with having a large portion of their lung removed. In such cases, these patients might have a less invasive procedure called segmental lung resection, where only a small part of the lung is removed instead.
Moreover, experts continue to explore the use of segmental lung resection as the main surgical method to fight off early-stage non-small cell lung cancer, which is a type of lung cancer.