Critical Analysis of the National Emphysema Treatment Trial Results for Lung-Volume-Reduction Surgery

https://doi.org/10.1016/j.thorsurg.2021.01.004Get rights and content

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Key points

  • The National Emphysema Treatment Trial directly compared lung-volume-reduction surgery with maximal medical therapy for severe chronic obstructive pulmonary disease in a prospective randomized controlled fashion.

  • The combination of a forced expiratory volume in 1 second (FEV1) less than or equal to 20% of predicted with either homogeneous emphysema or diffusing capacity of the lungs for carbon monoxide (DLCO) less than or equal to 20% of predicted encompasses a group too high risk for surgery.

  • In

National Emphysema Treatment Trial

The NETT was initiated in 1998 in order to clarify the benefit of LVRS. Previously published studies on the efficacy of LVRS were relatively small and included patient cohorts with differing clinical characteristics operated on using various surgical techniques. Almost all studies lacked long-term follow-up and did not comprehensively assess benefit, risk, or cost. NETT sought to reduce the variability in patient characteristics, surgical technique, patient care, and follow-up with the creation

Mortality

On initial analysis, 90-day mortality was revealed to be 7.9% (95% confidence interval, 5.9–10.3) in the surgery group, significantly higher than the 1.3% (95% confidence interval, 0.6–2.6) of the medical group (P<.001). This was however considered expected, given the immediate trauma of surgery and overall mortality was not significantly different between groups with a total morality of 0.11 deaths per person-year in both treatment arms. When the previously discussed high-risk group was

Six-Minute Walk Distance Reproducibility

Exercise capacity as measured by ergometry was used as a primary respiratory outcome measure in NETT but 6-minute walk distance was also analyzed as a secondary outcome. This test is commonly used in practice to measure functional and exercise capacity. Although it has been somewhat standardized, there is lack of consensus on the importance of course length, shape, or the role of practice/second walk. Four hundred seventy of the NETT participants at 17 institutions were asked to undergo a

Clinics care points

  • Lung volume reduction surgery reduces mortality and improves exercise capacity in appropriately selected emphysematous patients compared to medical therapy alone.

  • LVRS is most beneficial to those with heterogeneous localized emphysema and a decreased pre-operative exercise capacity.

  • Surgery is not recommended for those with either FEV1 or DLCO less than or equal to 20% of predicted.

Disclosure

The authors have no commercial, financial, or other conflicts of interest to disclose.

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References (22)

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    (2015)
  • Cited by (2)

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