Chronic Obstructive Lung Disease

Description

Alternative Names

Surgical Procedures

Surgical procedures for emphysema are still investigative. They are all very expensive and often not covered by insurance. The great majority of patients cannot be helped by surgery, and no single procedure is ideal for those that can be helped.

Lung and Liver Transplantation

Advanced emphysema is responsible for over half of the lung transplants performed. Three-year survival rates after a lung transplantation are about 60% for patients with either emphysema or AAT deficiencies. Techniques have been developed so that both lungs may be replaced in sequence. The increasingly long waiting time and the extraordinary expense are both significant problems.

Candidates. The best candidates are under 65 and have good general health aside from lung disease. A lung or liver transplantation may be the only hope for some patients with the inherited disease alpha 1-antitrypsin (AAT) deficiency-related emphysema. AAT is produced in the liver, so a healthy transplanted liver may produce adequate supplies of the protein.

Waiting Time. Unfortunately, up to a third of patients awaiting lung transplantation die before a suitable donor is available. There were 1042 lung transplantation operations in 2002, and as of this report there are nearly 4,000 people waiting for the operation. Not all lung transplant centers, even in major cities like New York, accept Medicare patients. The system is currently operated on a first-come first-served basis (rather than by urgency).

Complications. Drugs that suppress the immune system must be taken life-long after a transplantation to prevent the body from rejecting the transplanted organ. Nevertheless, rejection is the primary cause of late complications and death. The mortality rate from the procedure itself is about 10%.

Lung Volume-Reduction Surgery

Lung volume-reduction surgeries (LVRS) remove over 30% of severely diseased lung tissue and the remaining parts of the lung are joined together. Improvement in breathing after surgery appears to be largely due to the following factors:

• An improvement in the lung and chest wall's elastic recoil (its ability to spring back during breathing).
• Improvement in function of the muscles, such as the diaphragm, involved with breathing.

Outcomes. Two-year results of the largest study to date, called the National Emphysema Treatment Trial (NETT), indicate that patients who are good candidates for LVRS have better function and no higher risk for death than those on medical therapy. Mortality rates within 90 days of surgery are almost 8% compared to about 1% in patients on medical therapy. However, in spite of the early spike in deaths after surgery, there are no overall differences in long-term survival rates.

When the operation is successful, patients report significant improvement in walking distance, weight, and quality of life. Many patients can engage in active daily events, such as golf or climbing stairs, without oxygen. Even in carefully selected candidates, however, about 15% of patients derive little or no benefit from the procedure. (And about 4% become worse.) Furthermore, even in successful cases, the improvement is most notable within the first six months, after which the condition progresses again. Beyond two years, lung function deteriorates to the same level as it was before the procedure. It is not clear yet if surgery is cost effective over time compared to medical therapy.

Possible Candidates. For now, the procedure is used only in people who have severe emphysema and not chronic bronchitis. And, it is applicable only to a minority of these patients. Appropriate candidates are those with the following characteristics:

• Under 75 years old.
• Having severe obstruction (FEV1 less than 40% but higher than 20% of expected value).
• Carbon monoxide diffusing capacity of more than 20% of expected value.
• Hyperinflated lungs (total lung capacity greater than 120% of the predicted value).
• Appropriate candidates who have deficiency of alpha 1-antitrypsin, even if they have disease in the lower lobe, may do well.

The most recent NETT results indicate that surgical patients who had emphysema in the upper lungs and a low exercise capacity may have better survival rates and outcome than the same patient group given medical therapy. More research is needed to confirm these findings.

Poor Candidates for Surgery. Early results from NETT suggest that the following patients have a high risk for a poor outcome and are generally not good candidates:

• Those with a very low FEV1 (less than 20% of expected value), plus
• Those with carbon monoxide diffusing capacity of less than 20% of expected value, or
• Those with uniform distribution of emphysema in the lungs.

In the study, patients with these characteristics had a 16% mortality rate at 30 days after surgery compared to no deaths in similar patients who were treated with medications only. Such high-risk patients accounted for about 12.5% of the patient population in the study.

Patients may also be excluded if they have severe medical conditions that limit their life span; severe psychological problems; recent tobacco, drug, or alcohol dependence; chest wall deformity; corticosteroid dependence; or scarring around the membrane of the lung. Other indicators for a poor outlook include severe lung complications and isolated bullae (air pockets in diseased area of the lungs).

Specific Techniques. At this time, the preferred technique is bilateral lung volume reduction. To accomplish it, surgeons use either an open approach, which uses a large incision in the chest area, or video-assisted thoracoscopy (VATS), which is less invasive. Either method is effective and has similar complication rates. Lines of staples are typically used to reduce lung volume.

The alternative technique is unilateral lung volume reduction. Some centers believe this approach may cause fewer complications and slower decline in benefits, although not all evidence supports its use over the bilateral method.

Bullectomy

Another option for COLD is bullectomy, in which giant air pockets and surrounding lung tissue are removed. It is generally limited to younger patients, particularly those with 1-antitriptase deficiency.