Lung volume reduction surgery for native lung hyperinflation following single-lung transplantation for emphysema: which patients?

OBJECTIVES

Lung transplantation is an established treatment for patients with advanced emphysema. Double-lung transplantation is favoured to avoid complications following single-lung transplantation, including native lung hyperinflation. Nonetheless, single-lung transplantation continues due to limited donor organ availability. The aim of this study was to evaluate the pre-operative assessment, surgical techniques and outcomes in patients undergoing lung volume reduction surgery for native lung hyperinflation.

METHODS

Eight patients underwent lung volume reduction surgery for native lung hyperinflation between October 2008 and April 2011. Symptoms, pre-operative evaluation, peri-operative morbidity, length of stay, pulmonary function and survival were examined. The mean follow-up was 17 months.

RESULTS

Participants underwent high resolution CT and bronchoscopy with transbronchial biopsy and bronchial washings to exclude alternative causes for deterioration in pulmonary function tests. V/Q scan was performed to assess the contribution of each lung to overall function. Measurement of inspiratory airflow resistance in each lung was performed in one case. Seven patients underwent multiple wedge resections and one underwent bilobectomy. All patients survived to hospital discharge, and mean length of stay was 13.9 days. Functional improvement was demonstrated in all cases at follow-up, with a mean percentage increase of 29.3% in forced expiratory volume in one second and 21.6% in forced vital capacity. Symptomatic improvement was also reported by all patients post-operatively.

CONCLUSIONS

Lung volume reduction surgery for native lung hyperinflation is an effective treatment strategy with an acceptable level of surgical risk. Patient selection, however, remains vital. The non-anatomical multiple wedge excision technique used here was as effective as anatomical lung volume reduction surgery used in other series. With regard to pre-operative assessment, the measurement of single-lung inspiratory airflow resistance is of particular interest. We feel that this may provide an additional method of differentiating between native lung hyperinflation and obliterative bronchiolitis prior to surgery, thus improving patient selection.

Limitations of randomized clinical trials for evaluating emerging operations: the case of lung volume reduction surgery

Although unanswered questions remain, scores of observational studies and several small randomized clinical trials (RCTs) indicate that lung volume reduction surgery (LVRS) offers safe and effective palliation for a relatively well defined subset of patients with advanced emphysema. Nonetheless, Medicare and other insurers stopped reimbursement for the procedure. Subsequently, two multicenter RCTs on LVRS, the National Emphysema Treatment Trial (NETT) and the Overholt-BlueCross Emphysema Surgery Trial (OBEST), were launched with the stipulation that the procedure would not be paid for outside these trials. Thus access to LVRS has been denied to patients who could benefit but do not wish to participate in an RCT. Emerging operations, unlike new drugs or devices, pass through evolutionary changes and frequently fail to produce data that meet the scientific rigor required by randomized studies. In such a setting, the observational approach is more appropriate. Indeed, almost all operations in the present surgical armamentarium have been evaluated and have evolved through observational studies without the use of RCTs. By the time new operations are standardized and qualify for RCTs, benefits for certain patients may be demonstrated and randomization could involve unacceptable health hazards. Patients from this population should be offered the choice between participating in RCTs and having the operation outside the study. Imposition of financial restrictions that bars access to a therapy with known benefit is a questionable practice.