The treatment of early-stage lung cancer has evolved, moving towards surgeries that preserve as much healthy lung tissue as possible. These procedures, known as sublobar resections, stand in contrast to more extensive operations like removing an entire lobe (lobectomy) or a whole lung (pneumonectomy). These approaches aim to balance effective cancer treatment with maintaining the patient’s quality of life and respiratory capacity.
Two primary types of lung-sparing surgery are the segmentectomy and the wedge resection. Both are designed for smaller, early-stage tumors, but they differ fundamentally in their surgical philosophy and execution. Understanding the distinction between them is useful for grasping how surgeons approach localized lung disease.
What is a Segmentectomy and Wedge Resection?
A wedge resection is a non-anatomical procedure. In this surgery, the surgeon removes a small, wedge-shaped piece of tissue that contains the tumor along with a narrow border of healthy tissue. This approach is often compared to cutting a slice from a cake’s edge, as the cut does not follow any of the lung’s natural internal boundaries. It is most suitable for tumors located on the periphery, or the outer surface, of the lung.
The procedure is relatively straightforward compared to more complex resections. Because it is a non-anatomical cut, the surgeon’s main goal is to ensure the tumor is excised with a sufficient margin of normal tissue. This makes it a less invasive option that removes a minimal amount of lung parenchyma, the functional tissue of the lung.
A segmentectomy, in contrast, is an anatomical resection. The lungs are organized into lobes, and each lobe is subdivided into distinct functional units called bronchopulmonary segments. Each segment has its own dedicated airway (a segmental bronchus) and its own arterial blood supply. A segmentectomy involves the precise removal of one or more of these entire segments, similar to removing an intact slice from an orange along its natural dividing planes.
This anatomical approach is more technically complex than a wedge resection. It requires the surgeon to carefully dissect and divide the specific bronchus and blood vessels that supply the targeted segment. Both segmentectomy and wedge resection can be performed using minimally invasive techniques, such as video-assisted thoracoscopic surgery (VATS) or robotic-assisted surgery, which involve smaller incisions and can lead to a quicker recovery.
Criteria for Choosing a Procedure
The decision between a wedge resection and a segmentectomy depends on several factors, with tumor location being a primary consideration. A wedge resection is reserved for tumors in the outer third of the lung. For deeper tumors, a wedge resection may not be feasible or could risk leaving cancer cells behind, making an anatomical segmentectomy the more appropriate choice.
Tumor size also influences the surgical approach. For very small tumors, less than two centimeters in diameter, either procedure might be effective. As a tumor increases in size, a segmentectomy is favored to ensure adequate surgical margins. Guidelines recommend a margin of at least two centimeters or a distance equal to the tumor’s diameter, which is more reliably achieved by removing an entire lung segment.
A significant advantage of segmentectomy is the ability to perform a more thorough lymph node assessment. Removing an entire lung segment allows the surgeon to also remove and examine the lymph nodes within that segment and its drainage path. This evaluation is important for accurately staging the cancer, as cancer in the lymph nodes indicates a more advanced disease that may require additional treatments. A wedge resection does not include such a comprehensive lymph node removal.
The patient’s overall health and lung function are also taken into account. For individuals with severely compromised pulmonary function from conditions like emphysema, a wedge resection might be selected to preserve the maximum amount of lung tissue possible. In these cases, the priority of preserving lung capacity may outweigh the oncological benefits of a more extensive resection, representing a calculated trade-off between cancer control and maintaining respiratory function.
Comparing Surgical Outcomes
Historically, segmentectomy has been associated with better long-term survival and lower rates of local cancer recurrence compared to wedge resection, particularly for tumors larger than two centimeters. This is attributed to the wider surgical margins and the more comprehensive lymph node dissection inherent in an anatomical segmentectomy. For very small tumors (less than 2 cm), some modern studies have shown that survival outcomes can be comparable between the two procedures.
While a wedge resection technically removes less total lung tissue, a segmentectomy respects the lung’s natural anatomical and functional planes. This can sometimes result in better preservation of the remaining lung’s mechanics. While some studies show segmentectomy preserves lung function better than a larger lobectomy, the difference in function between a segmentectomy and a wedge resection is not always clinically significant.
A common complication after lung surgery is a prolonged air leak, where air escapes from the raw lung surface. This issue can be more frequent after a segmentectomy because it creates a larger raw surface area compared to a wedge resection. Other surgical risks, such as infection or bleeding, are broadly similar between the two procedures, especially when performed using minimally invasive techniques.
The Recovery Process
Following either surgery, initial recovery takes place in the hospital for a few days, depending on the surgical method and healing progress. Patients will have one or more chest tubes in place to drain excess fluid and air from the chest cavity. This allows the remaining lung to fully expand and heal. The tubes are removed after one to five days, once drainage has subsided.
Pain management is a focus of post-operative care, as discomfort around the incision sites is common. The medical team provides medication to manage this and help the patient participate in recovery activities. Respiratory therapy is also initiated soon after surgery to prevent complications like pneumonia. This involves deep breathing exercises and using an incentive spirometer to keep the lungs active.
Returning to normal life is a gradual process that can take several weeks to months. Patients are encouraged to start walking as soon as possible to improve blood flow and lung function. Strenuous activities and heavy lifting are restricted for several weeks. The timeline for returning to work varies for each person, depending on the surgery, overall health, and lifestyle demands.