Lung Volume Reduction Surgery (COPD)

Emphysema is a type of chronic obstructive pulmonary disease (COPD) marked by an abnormal and persistent expansion of the airspaces distal to the terminal bronchioles, as well as alveolar wall damage. Dyspnea is caused by emphysema, which causes airflow restriction, hyperinflation, and the loss of gas-exchanging surfaces in the lungs (increased physiologic dead space).

Patients with chronic obstructive pulmonary disease (COPD) or severe emphysema may benefit from lung volume reduction surgery (LVRS). Despite being initially described in the 1950s, it was not widespread until the 1990s, thanks to advances in surgical technique and the management of consequences. The National Emphysema Treatment Trial (NETT), a major, multidisciplinary, multicenter, randomized control trial for LVRS, was published in 2003 to investigate the efficacy of LVRS on quality of life and survival benefit compared to existing medical therapy. The results of the comprehensive NETT study lead to current eligibility criteria for LVRS patients, and it is regarded as a landmark study. Long-term LVRS results, unilateral vs. bilateral operation, cost-effectiveness, and LVRS as a bridge to lung transplant are all fields of LVRS research that are still being investigated.

Anatomy and Physiology

COPD is a prominent cause of death worldwide, with an increasing incidence, and individuals with severe emphysema might have a poor quality of life due to symptoms that impair functionality. Emphysema causes minor airway disease and decreased lung elastic recoil, which makes lung hyperinflation from air trapping more likely. An increase in functional residual capacity (FRC) and a reduction in inspiratory capacity (IC) are two pulmonary function tests (PFT) that show this obstructive process. Early surgical approaches focused on modifying the chest wall or diaphragm, but modern surgical techniques for emphysema include transplantation, bullectomy, and lung volume reduction surgery (LVRS). The short- and long-term analyses show that LVRS positively affects respiratory mechanics and increases respiratory muscle strength in specific patient populations over months to years.

Lung Volume Reduction Surgery Indications

The NETT was a randomized control trial that included over 1,000 patients across 17 institutions in 2003 to see how medical therapy compares to medical therapy with LVRS. The following were among the NETT inclusion criteria:

• A BMI of lower than 32 kg/m2.
• FEV1 (forced expiratory volume in one second) expected to be lower than 45 percent
• PaCO2 (partial pressure of carbon dioxide in the blood) lower than 60 mmHg
• Arterial partial pressure of oxygen (PaO2) greater than 45 mm Hg
• A distance of more than 140 meters walked during the 6-minute walk test.
• Before the initial screening, you must not have smoked for at least 4 months.

PaO2 was 64 (plus/minus 10) mmHg and PaCO2 was 43 (plus/minus 6) mm Hg in surgical patients in NETT. They found that heterogeneous localization of upper lobe predominant emphysema and low baseline exercise performance predicted lower mortality after LVRS relative to no surgery in the non-high-risk category. Females' low exercise capacity was defined as less than 25 Watts and men's low exercise capacity was classified as less than 40 Watts.

Lung Volume Reduction Surgery Contraindications

The cut-off for terminating the protocol in the landmark NETT experiment was greater than a 10% 30-day death rate for individuals in the treatment arm of the research. This includes keeping track of the different subgroups of patients who were undergoing LVRS. After randomization, patients with an FEV1 less than 20% predicted and either a diffusion capacity for carbon monoxide (DLCO) less than 20% predicted or the presence of homogeneous emphysema had a 30-day mortality rate of 18 percent in the LVRS arm compared to zero percent in the medical therapy alone arm, according to the NETT Research Group. Even those who underwent surgery had a similar quality of life and just little functional improvements. Patients with this subgroup of LVRS were identified as having:

• FEV1 level lower than 20 percent predicted
• DLCO of lower than 20% predicted OR Homogeneous emphysema on computed tomography (CT) scan.

This subgroup of patients was more likely to be hurt by surgical treatment for severe emphysema than to benefit from it, with a greater risk of death after LVRS.

Depending on their disease pattern and exercise performance, the non-high-risk patients were separated into four categories. Patients in the non-high-risk category with non-upper lobe emphysema and low exercise performance did not benefit from LVRS relative to medical therapy in terms of survival. LVRS increased mortality and did not enhance exercise capacity in individuals in the non-high-risk category with solid exercise capacity and mostly non-upper lobe emphysema.

Equipment

The LVRS equipment required varies depending on the approach chosen. LVRS is often treated with one of two surgical methods, which vary by the institution:

• Sternotomy
• Video-assisted thoracic surgery (VATS)

Special surgical tools, such as a sternal saw for median sternotomy or insufflation/camera equipment for VATS, should be prepared in advance. A double-lumen tracheal tube, arterial line insertion/monitoring, and intra-operative/post-operative pain management measures (epidural, nerve block, patient-controlled analgesia pump) should all be decided ahead of time. Although some hospitals utilize buttressing material and a stapler to avoid air leaks, there is no evidence that this reduces postoperative air leaks in LVRS patients.

Personnel

A functional operation theater personnel is required for LVRS to conduct thoracic surgery. A thoracic surgeon, surgical assistant, operating theater nurses, and anesthesiologist are among those involved. Pain management, chest tube management, and an aggressive bowel regimen should all be part of the post-operative care provided by individuals who are familiar with postoperative thoracic surgery patients. Patients with severe emphysema are usually monitored by a pulmonologist and should be followed up both before and after surgery.

Preparation

Patients must have a complete preoperative workup before performing LVRS to guarantee correct patient selection and potential maximum benefit when compared to medical therapy for severe COPD. A chest radiograph and a high-resolution CT scan are examples of imaging. An arterial blood gas should be conducted as part of the laboratory workup. FEV1 and DLCO levels are measured during the pulmonary function test. To determine oxygen requirements and distance, a 6-minute walk test is commonly used. This statistic can also be used to measure progress after rehabilitation. If substantial coronary artery disease is suspected, patients should receive a cardiopulmonary checkup that includes an electrocardiogram (ECG) and a stress test.

The majority of patients join pulmonary rehabilitation programs for a few weeks to see if their functional status and exercise ability improve. Patients must also adhere to smoking cessation guidelines (usually more than 6 months). After LVRS, patients should participate in pulmonary postoperative rehabilitation programs.

Lung Volume Reduction Surgery Technique

With endotracheal intubation, all patients should be put under general anesthesia. NETT did not force hospitals to use uniform surgical methods and allowed reinforcing material to try to avoid air leaks. It encompassed both median sternotomy and video-assisted thoracic surgery (VATS). As a result, both approaches were used in this large randomized control study and assessed. LVRS tries to minimize the residual volume in pulmonary function tests and to mechanically improve respiratory function by modifying anatomic and physiologic lung biomechanics by surgically removing parts of the lung parenchyma (typically with a stapling instrument). The patient must be in lateral decubitus on one side and then shifted on the opposite side of the body when undergoing VATS for bilateral LVRS. median sternotomy should be carried out in the presence of the patient in the supine position.

There was no variation in 90-day mortality or intraoperative blood loss between median sternotomy and VATS, according to an updated evaluation of NETT and long-term follow-up. However, VATS appeared to reduce recovery time and hospital costs. Institutional policy and provider familiarity with the technique should guide the decision to conduct one operation or the other.

Other endobronchial procedures are still under investigation, and non-open surgical approaches like endobronchial valve implantation can be done with a bronchoscope to try to achieve the same goals without making a surgical incision.

Lung Volume Reduction Surgery Complications

The NETT experiment looked at surgical mortality and cardiopulmonary morbidity in patient groups. Cardiopulmonary morbidity remained significant, at around 5 percent, according to the sub-analysis. Major pulmonary and cardiovascular complications were also common, with 25 to 30 percent of patients in the non-high-risk subset of LVRS patients experiencing them. Patients with non-upper-lobe-predominant emphysema were one of the factors related to increased mortality, according to Naunheim et al.

Other issues to consider are:

• Air leak.
• Arrhythmias, myocardial infarction, or pulmonary embolus are all major cardiovascular problems.
• Hypoxia
• Pneumonia and other infections

Respiratory failure necessitating reintubation, extended intubation, or tracheostomy are major pulmonary problems.

Air leak is one of the most prevalent problems after LVRS, with 89 percent of NETT trial patients reporting it within the first 30 days. Only 13% of patients reported an air leak that lasted longer than 30 days. It was determined that the lack of an air leak following surgery had nothing to do with the surgical approach.

The thoracic surgery unit should conduct a specified number of cases each year to reduce postoperative problems after LVRS. Although there is no information on the specific number of operations performed per year or overall experience, a minimum of 30 procedures and an annual number of 20 should be expected, similar to technical difficult procedures such as video-assisted thoracoscopic surgery (VATS)-lobectomy. Furthermore, after a comprehensive discussion, thorough patient selection is required. Advanced age, hypercapnia, cachexia, homogeneous distribution of emphysema, pulmonary hypertension, low diffusion capacity, low forced expiratory volume, frequent hospitalizations owing to recurrent infection, and patients on steroid medication have all been linked to increased morbidity and death. Smoking has been shown to increase postoperative morbidity and mortality; thus, patients should quit smoking at least 6 to 12 weeks before LVRS. Prior to surgery, the NETT requires a four-month smoking-free period. Patients undergoing any type of interventional treatment for emphysema at our hospital must have quit smoking for at least six months prior to treatment.

Interdisciplinary patient care involving thoracic surgeons, anesthesiologists, pulmonologists, physiotherapists, and nursing personnel is required to ensure the best postoperative outcomes. Due to the high prevalence of comorbidities in COPD patients, preoperative medical therapy optimization, including pulmonary rehabilitation, may help to lower the risk of postoperative problems.

Lung Volume Reduction Surgery Postoperative care

Early Extubation

Extubation is only possible if there is no substantial bronchospasm, secretions, hypercapnia, or acidosis at the end of the procedure. If other criteria are met, patients with hypercapnia may still be extubated. With the patient in a head-up posture, bronchodilators must be nebulized frequently or continuously. If serial blood gases suggest growing hypercapnia, noninvasive ventilatory support can be provided to regulate gas exchange and reduce the work of breathing while the case is being investigated further.

Air Leak

In contrast to lung cancer surgery, the majority of patients who have LVRS experience an air leak throughout the recovery phase. 92 percent of patients in the NETT had an air leak during the first 30 days after LVRS. Patients with a primarily lower lobe pattern of emphysema had less air leakage than patients with other emphysema patterns. A limited diffusing capacity and the presence of significant adhesions were also substantially linked to the likelihood of air leaks.

In patients with underlying severe emphysema, the strategy has been to insert the chest tubes to water-seal rather than suction because current research suggests that this is the optimal approach.

Postoperative Respiratory Failure

Early mobilization, reduced use of narcotic analgesics, and proper and early antibiotic therapy will all assist to reduce the occurrence of respiratory failure. Noninvasive ventilation has been used routinely in the immediate postoperative period at several sites to prevent hypoventilation, atelectasis, and hypoxia.

Antibiotics should not be neglected if a respiratory infection is suspected. Antibiotic medications should be chosen based on the organisms found in this group. Once microbiologic information revealing an organism and antibiotic sensitivities is accessible, treatment should be narrowed quickly and a stop date set.

Early Mobilization

When possible, early postoperative mobilization after LVRS should be implemented to effectively decrease the occurrence of atelectasis, reduce the use of narcotic analgesics, speed up recovery, enhance mood, and prevent muscle atrophy.

Clinical Significance

In the NETT trial, patients with mostly upper lobe pattern of emphysema and inadequate exercise capacity exhibited lower mortality when compared to medical therapy alone. Despite research suggesting that LVRS is effective in treating certain types of severe emphysema patients, it is thought that LVRS is underutilized in the United States. According to Medicare data from 2004 to 2006, the number of LVRS operations appears to have stayed modest and stable. The cost-effectiveness of LVRS plus NETT in the subset of patients with upper lobe emphysema and low exercise performance was also better than the trial's overall cost-effectiveness. Patients must also be screened using imaging to see if they are suitable candidates.

LVRS can be used as a pre-transplant and post-transplant adjunct for adult and pediatric lung transplant recipients, in addition to becoming a surgical therapy choice for emphysema patients. Because of their medical complexity, post-operative care for patients with end-stage chronic obstructive pulmonary disease necessitates a multi-professional strategy to obtain the best possible results. Patients who benefit from an endoscopic approach to LVRS with endobronchial valves are currently being studied.

Bronchoscopic Lung Volume Reduction (BLVR) with Valves

Endobronchial valve placement is another name for bronchoscopy lung volume reduction (BLVR) with valves.

Small one-way valves are implanted into the airways that feed the most severely afflicted section of your lung (the target area). The valves are inserted using a bronchoscope, which is a fiberoptic camera. You will be asleep or given a general anesthetic for this procedure.

The valves prevent air from entering the lung's target location, causing the lobe to collapse. Instead of being large, saggy, and obstructing the airflow, the target area now takes up only a little amount of space in the chest, allowing healthy areas of the lung to expand. This can produce the same result as surgically removing the lung area, but it is not as invasive as surgery. It's also a technique that can be reversed.

The valve installation method takes less than one hour. However, you will be kept in the hospital for 3 nights to be monitored.

Who is Suitable for Treatment with Valves?

Valve placement and LVRS are both appropriate for similar populations.

The main difference is that valve treatment only functions if the target lung lobe can be completely blocked off. Even though the airways are blocked, if air can get into the target region from the lobe adjacent to it, it will not shrink. Collateral ventilation is the term for this. You may encounter the expressions "CV positive" and "CV negative" because this is commonly abbreviated to CV.

Valve installation is not recommended for people who have collateral ventilation. As a result, it's critical to recognize this by:

• CT scan is used to determine whether the lines that separate the lobes of the lung, known as fissures, are intact. This is named as "fissure integrity" occasionally.
• During a bronchoscopy, a specific balloon catheter is used to measure collateral ventilation. Chartis assessment is the name for this method.

Lung volume reduction surgery may be a substitute for valve therapy if there is collateral ventilation (CV positive).

Benefits and Risks of Bronchoscopic Lung Volume Reduction (BLVR)

Endobronchial valves can enhance lung function, exercise performance, and quality of life in properly selected persons.

When a minor tear or air leak develops during valve insertion, a significant challenge arises. This can result in a pneumothorax, which is when the lung on that side collapses. It happens in around a quarter of the time.

Pneumothorax can cause chest pain and make you feel short of breath. However, it can sometimes appear on a chest X-ray without causing any complaints. If this occurs, it may clear up on its own, or you may need a tube placed into the chest to allow the air to leave. It is possible that you will stay in the hospital for a couple of days.

If a pneumothorax occurs, it usually happens shortly after the surgery. As a result, you will be monitored in the hospital for three days. If it occurs after you have returned home, the team will provide you with written instructions on how to seek immediate professional care.

What is Better Valve or Surgery?

Both treatments have been shown to improve breathlessness and quality of life in carefully selected persons. Before recommending the best solution, the team of health care professionals will evaluate the lung function, emphysema distribution, and other aspects in your case.

There have been no trials that directly compare valves and surgery to date. For more than 25 years, lung volume reduction surgery has been performed, and there is a suggestion that it can help patients live longer. Valve therapy, according to experts, is expected to have a similar advantage. However, no long-term research has been done to back this up. Clinical study data are likely to be released soon, and they may aid in decision-making.

Conclusion

In emphysema, lung volume reduction surgery (LVRS) is still the most effective approach to reducing lung volume. There are several non-surgical approaches that are the subject of ongoing and substantial research to find the optimal approach, as none of them have demonstrated the same level of efficacy as the surgical process. In correctly selected individuals with moderate to severe emphysema, LVRS provides long-term relief of dyspnea. For an effective LVRS, proper patient selection and prior preparation are required. Professionals from pulmonary healthcare, thoracic surgery, thoracic anesthesiology, critical care medicine, rehabilitation medicine, respiratory therapy, chest imaging, nursing, and the patient are all required to participate and engage in an effective LVRS program.