Lung Volume Reduction Surgery

Anatomy and Physiology

LVRS primarily targets patients with severe emphysema, a subtype of chronic obstructive pulmonary disease (COPD). With a rising incidence, COPD is a leading cause of mortality worldwide, and patients who have severe emphysema can have a poor quality of life with symptoms that affect functionality.[8] The destruction of alveoli characterizes emphysema, the tiny air sacs where gas exchange occurs in the lungs. This damage leads to the formation of large, nonfunctional air spaces called bullae, which reduce the surface area available for gas exchange and trap air, leading to hyperinflation of the lungs. The hyperinflated lungs hinder the diaphragm's ability to contract and relax properly, thus impairing the mechanics of breathing and reducing the overall efficiency of the respiratory system. The changes in pulmonary function tests that demonstrate this obstructive process include an increase in functional residual capacity and a decrease in inspiratory capacity.[9] 

Early surgical approaches were focused on altering the chest wall or diaphragm, but modern surgical interventions for emphysema include transplantation, bullectomy, and LVRS.[8] Bullectomy and LVRS are designed to decrease hyperinflation, enhancing lung function, exercise capacity, and survival rates. Research data has shown that while bullectomy can temporarily relieve dyspnea and improve some respiratory function indicators, these benefits may diminish over time.[10] The short-term and long-term analysis demonstrates that LVRS increases respiratory muscle strength over months to years and improves respiratory mechanics in specific patient populations.[9] 

The anatomy relevant to LVRS includes the upper lobes of the lungs, which are often more affected by emphysematous changes than the lower lobes. The surgery typically involves resecting approximately 20% to 30% of the most diseased lung tissue, usually from these upper lobes. By removing the nonfunctional, hyperinflated areas, LVRS attempts to decrease the residual volume in PFTs and mechanically improve respiratory functionality by altering anatomic and physiologic lung mechanics, which has several physiological benefits.[9] The physiological effects of LVRS are multifaceted:

• Improved lung mechanics
  • Removing the hyperinflated, nonfunctional lung tissue allows the remaining healthier lung tissue to expand more effectively. This reduces the lung volume and helps the diaphragm to a more optimal position, improving its ability to contract and enhance ventilatory efficiency.
• Enhanced gas exchange
  • By reducing the volume of dead space in the lungs, LVRS can improve gas exchange efficiency. This can lead to better oxygenation and carbon dioxide removal from the blood.
  • The surgery helps to decrease the work of breathing by improving the mechanical properties of the lungs and reducing the resistance encountered during respiration. Patients often experience less breathlessness and an increased capacity for physical activity.
• Improved cardiac function
  • Severe lung hyperinflation can adversely affect the heart by compressing it and reducing cardiac output. By reducing lung volume, LVRS can alleviate this compression, potentially improving cardiac function and overall hemodynamics.

In summary, LVRS anatomically targets the most diseased areas of the lungs, typically the upper lobes, to improve respiratory mechanics and physiological function. The surgery alleviates lung hyperinflation, enhances diaphragm efficiency, improves gas exchange, reduces the work of breathing, and may positively affect cardiac function. These anatomical and physiological improvements can significantly improve a patient's quality of life and exercise capacity with severe emphysema.

Indications

The National Emphysema Treatment Trial, NETT, published in 2003, was a randomized control trial across 17 institutions with over 1000 patients enrolled to determine the effect of medical therapy compared to medical treatment and LVRS. As previously stated, this study now guides our inclusion criteria for LVRS today. These criteria include:

• Body mass index less than 32 kg/m²
• Forced-expiratory volume in 1 second (FEV₁) of less than 45% predicted
• PaCO₂ less than 60 mm Hg
• PaO₂ greater than 45 mm Hg
• A 6-min walk test distance of greater than 140 m
• No smoking for at least 4 months before initial screening [8]

Surgical patients in NETT had an average PaO2 of 64 mm Hg (plus or minus 10) and PaCO₂ of 43 mm Hg (plus or minus 6).[3] In the non-high-risk group, they demonstrated that heterogeneous distribution of upper lobe predominant emphysema and low baseline exercise capacity predicated decreased mortality after LVRS compared to no surgery. Low exercise capacity was defined as less than 25 workloads (W) for women and less than 40 W for men.[8]

Contraindications

In the landmark NETT trial, the cut-off for stopping the protocol was greater than an 8% 30-day mortality rate for patients enrolled in the treatment arm of the study. This included monitoring the subgroups of patients undergoing LVRS. The NETT research group found that, after randomization, patients with an FEV₁ less than 20% predicted and either a diffusion capacity for carbon monoxide (DLCO) of less than 20% predicted or the presence of homogenous emphysema had a 30-day mortality rate of 16% in the LVRS arm (69 patients) compared to 0% medical therapy alone arm (70 patients). Even those who survived surgery had similar quality of life and only minor improvements in functional tests. This particular subgroup of LVRS patients was defined as those with:

• A low FEV1 (less than 20% predicted) AND
• A DLCO of less than 20% predicted OR
• Homogenous emphysema on computed tomography scan

This subgroup of patients was more likely to be harmed than to benefit from surgical intervention for the treatment of severe emphysema, with a higher risk for death after LVRS (high-risk group).[11] The non-high-risk patients were subdivided into 4 groups based on their disease pattern and exercise capacity. Patients in the non-high-risk subgroup with primarily nonupper lobe emphysema and low exercise capacity did not gain any increased survival with LVRS compared to medical therapy. Among patients in the non-high-risk subgroup with high exercise capacity and primarily nonupper lobe emphysema, LVRS increased mortality compared with medical treatment and did not improve exercise capacity.[8] 

Equipment

The equipment necessary for LVRS depends on the type of approach used. Typically, 2 different surgical techniques for LVRS are used and are institution-dependent:

• Median sternotomy
• Video-assisted thoracoscopic surgery (VATS) [8] 

Special surgical equipment, such as a sternal saw for median sternotomy or insufflation/camera equipment for VATS, should be prepared ahead of time. Special anesthesia considerations, including a double-lumen endotracheal tube, arterial line insertion/monitoring, and intraoperative/postoperative pain-control methods, such as an epidural, nerve block, or patient-controlled analgesia pump, should be determined ahead of time. Although some institutions use buttressing material with their stapler to try and prevent air leaks, there has been no evidence to suggest that this decreases postoperative air leaks in LVRS patients.[12] 

Personnel

Personnel necessary for LVRS include functional operating room staff to perform thoracic surgery. This includes a thoracic surgeon, surgical assistant, operating room nurses, and anesthesiologist. Postoperative care should be performed by those experienced in caring for individuals after thoracic surgery, which usually includes pain control, chest tube management, and an aggressive bowel regimen. A pulmonologist generally follows patients with severe emphysema and should maintain preoperative and postoperative follow-up.

Preparation

Before undergoing LVRS, patients require an extensive preoperative workup to ensure the proper patient selection and potential maximal benefit compared to medical therapy for severe COPD. This includes imaging: a chest radiograph and a high-resolution CT scan. Laboratory workup, including an arterial blood gas should also be performed. Pulmonary function tests include values for FEV₁ and DLCO. A 6-minute walk test is standard to observe oxygen requirements and distance. This is also a baseline metric to assess improvement after rehabilitation. Patients should also have a cardiopulmonary workup, including an electrocardiogram and a stress test if significant coronary artery disease is suspected. Most patients enroll in pulmonary rehabilitation programs for several weeks to observe whether their functional status and exercise capacity improve. They must also comply with smoking cessation requirements (usually over 6 months). Pulmonary postoperative rehabilitation programs are also recommended for patients after they undergo LVRS. 

Technique or Treatment

NETT did not require institutions to comply with uniform surgical approaches, including median sternotomy or VATS, and allowed buttressing material to prevent air leaks.[8] Thus, this large randomized control trial performed and analyzed both techniques. According to an updated NETT and long-term follow-up review, median sternotomy and VATS did not differ in 90-day mortality or intraoperative blood loss.[12] However, recovery time and hospital costs appeared lower with VATS (about $10,000).[8] Whether to perform 1 procedure or the other should be guided by institutional policy and provider comfort with the technique. The techniques through which LVRS can be performed are briefly described below: 

Median Sternotomy 

The median sternotomy approach for LVRS involves making a vertical incision along the midline of the chest to gain access to the lungs. This procedure starts with the patient in a supine position under general anesthesia. The surgeon makes an incision from the sternal notch to just above the xiphoid process, dividing the sternum longitudinally to expose the thoracic cavity. Retractors hold the sternum open, providing a clear view and access to both lungs. The surgeon identifies the most diseased, nonfunctional areas of the lungs, typically in the upper lobes, and resects approximately 20% to 30% of this tissue. Stapling devices and electrocautery ensure precise cutting and sealing of lung tissue to prevent air leaks. After the diseased tissue is removed, the lungs are reexpanded, and the surgeon checks for air leaks. Chest tubes are placed to facilitate postoperative drainage and reexpansion of the lungs. Finally, the sternum is closed with wires, and the incision is sutured. This technique allows for a bilateral approach, addressing both lungs in a single operation, which benefits patients with widespread emphysema.

VATS

The VATS technique for LVRS is a minimally invasive alternative to median sternotomy. Under general anesthesia, the patient is put into a lateral decubitus position to allow access to the thoracic cavity. The surgeon makes several small incisions, typically 3 to 4, between the ribs on one side of the chest. A thoracoscope is inserted through 1 of the incisions, providing a video feed to a monitor, which guides the surgeon during the procedure. Additional ports are used for surgical instruments. The surgeon identifies the diseased areas of the lung and uses endoscopic stapling devices to resect the nonfunctional tissue. The staples both cut and seal the lung tissue to prevent air leaks. The excised tissue is then removed through one of the ports. After resection, the lung is reexpanded, and the surgeon checks for air leaks using a saline solution. Chest tubes are placed to manage postoperative drainage and ensure proper lung reexpansion. The small incisions are then closed with sutures. If the contralateral side is also going to be addressed, the patient is then repositioned to the other side, and the procedure is repeated. VATS is associated with less postoperative pain, shorter hospital stays, and quicker recovery compared to median sternotomy. However, it may not be suitable for all patients, depending on the extent and location of lung disease.

Alternative Techniques

Due to LVRS limitations, less invasive alternatives have been developed. Using 1-way endobronchial valves (EBVs) for LVRS was first reported in 2003 and subsequently investigated in the EBV for Emphysema Palliation Trial (VENT) trial. Results from multiple randomized controlled trials have since confirmed the effectiveness of EBVs for patients with severe emphysema characterized by gas trapping, hyperinflation, reduced exercise capacity, and intact interlobar fissures. Endoscopic lung volume reduction has now become an established, guideline-recommended treatment for individuals with severe COPD.[13]

Complications

In NETT, patient cohorts were analyzed for operative mortality and cardiopulmonary morbidity. The subanalysis found that cardiopulmonary morbidity remained high at approximately 5.5%. Major pulmonary and cardiovascular complications were also relatively high, occurring in 20% to 30% of patients (out of 511) who were considered a non-high-risk subset of LVRS patients. Naunheim et al found that patients with non-upper-lobe-predominant emphysema were 1 of the factors associated with increased mortality.[14]

Other complications include:

• Air leaks
  • The most common complication of LVRS is prolonged air leaks, which occur when the lung tissue does not seal appropriately after resection. This can lead to persistent pneumothorax and may require extended use of chest tubes or additional surgical interventions. 
  • Prolonged air leaks can lead to extended hospital stays, higher readmission rates, increased intensive care unit admissions, and a greater risk of postoperative pneumonia.[15]
  • NETT estimated that 90% of patients had an air leak in the 30-day postoperative period. However, only 12% of patients had an air leak over 30 days. NETT also concluded that not having a postoperative air leak was not associated with the specific surgical technique.[16]
• Infection
  • Postoperative infections, including pneumonia, wound infections, and empyema (infection of the pleural space), are significant risks. These infections can prolong hospital stays and require aggressive antibiotic therapy or surgical drainage.
• Cardiovascular complications
  • These include myocardial infarction, arrhythmias, or pulmonary embolism. 
• Pulmonary complications
  • These include hypoxia and respiratory failure requiring reintubation, prolonged intubation, or tracheostomy.[12][14]
• Bleeding
  • Intraoperative or postoperative bleeding is a potential complication that may require blood transfusions or additional surgical intervention to control.
• Atelectasis
  • Partial or complete collapse of the lung can occur postoperatively, leading to reduced lung function and increased risk of infection.
• Pleural effusion
  • This fluid accumulation in the pleural space may require drainage and can affect lung reexpansion.
• Death
  • Although rare, mortality is a serious risk associated with LVRS, particularly in patients with severe comorbidities or poor overall health.

Clinical Significance

LVRS holds significant clinical importance for patients with severe emphysema, particularly those with an upper lobe distribution of the disease and low exercise capacity. NETT demonstrated that such patients experienced improved mortality rates compared to those receiving medical therapy alone.[3] Despite this, LVRS remains underutilized in the United States. Medicare data from 2004 through 2006 indicate that the number of LVRS procedures has remained low and stagnant.[4][12] This underutilization persists despite evidence from NETT indicating that LVRS improves survival and has favorable cost-effectiveness in patients with upper lobe emphysema and low exercise capacity.[17] Effective patient screening through imaging and referral to specialized NETT centers are crucial to identifying appropriate candidates for LVRS.[8] 

In addition to its role as a surgical treatment for emphysema, LVRS can serve as an adjunctive therapy for both adult and pediatric lung transplant patients before and after transplant.[7][18] Given the medical complexity of end-stage COPD patients, postoperative care requires an interprofessional approach to optimize outcomes. Research continues to explore the benefits of endoscopic approaches to LVRS, such as using EBVs. Several randomized controlled trials have evaluated EBVs, using benchmarks like a minimum clinically important difference of at least a 12% improvement in FEV₁ or a reduction of at least 350 mL in residual volume (RV). The multicenter TRANSFORM randomized controlled trial showed that patients treated with EBVs experienced significant improvements, with a mean FEV₁ increase of 140 mL (a 20.7% change) and an average RV reduction of 660 mL after 6 months. These findings underscore the potential of EBVs as a minimally invasive alternative to LVRS, although differences in methodologies across studies can make direct comparisons challenging.[13]

Enhancing Healthcare Team Outcomes

Effective management and successful outcomes of lung volume reduction surgery (LVRS) necessitate a comprehensive and coordinated approach by a multidisciplinary team. Physicians, including pulmonologists and thoracic surgeons, must collaborate closely to identify suitable candidates through detailed assessment and imaging studies, ensuring patients meet the criteria established by the National Emphysema Treatment Trial. Advanced clinicians and nurses play crucial roles in preoperative education, helping patients understand the procedure, potential risks, and postoperative care requirements. They also provide continuous monitoring and support during recovery, ensuring early detection and management of complications.

Pharmacists contribute by optimizing medication management, addressing preexisting conditions, and ensuring appropriate use of antibiotics and pain management strategies. Respiratory therapists are integral in preoperative and postoperative pulmonary rehabilitation, helping improve patients’ lung function and exercise capacity. Effective interprofessional communication and care coordination are paramount, involving regular team meetings, shared electronic health records, and clear protocols to facilitate seamless transitions between different stages of care. This collaborative approach enhances patient-centered care and outcomes and improves patient safety and overall team performance, ultimately leading to more successful LVRS procedures and better long-term patient health.

Nursing, Allied Health, and Interprofessional Team Monitoring

Patients with LVRS are at high risk for cardiopulmonary morbidities. There is about a 20% to 30% morbidity rate. Since the complications are multifactorial in patients already at risk for cardiac and pulmonary complications, a well-prepared interprofessional healthcare team can improve outcomes and patient safety through appropriate monitoring, including pulse oximetry and telemetry monitoring. Interprofessional teams need to be educated about potential complications and treatment. For example, a postoperative LVRS may require pain medication, but this may also worsen respiratory status through respiratory depression that may be poorly tolerated.[14]