Respect the Middle Lobe: Perioperative Risk of Bilobectomy Compared With Lobectomy and Pneumonectomy

In some cases of right-sided lung cancer, tumor extension, bronchial involvement, or pulmonary artery infiltration may necessitate bilobectomy. Although the middle lobe is believed to represent a fraction of total lung function, the morbidity and mortality associated with bilobectomy is not well described.

We retrospectively identified patients in The Society of Thoracic Surgeons Database who underwent lobectomy, bilobectomy, or pneumonectomy for lung cancer from 2009 to 2017. The primary outcome was 30-day perioperative mortality. We performed propensity matching by patient demographics, comorbidities, and perioperative variables for each surgical type against bilobectomy and ran Cox proportional hazard models. Secondary outcomes of 30-day morbidity and mortality of upper vs lower bilobectomy were also compared.

Within the study period 2911 bilobectomy, 65,506 lobectomy, and 3370 pneumonectomy patients met the inclusion criteria. Patients undergoing pneumonectomy and bilobectomy had fewer comorbidities than lobectomy patients. After propensity matching 30-day mortality of bilobectomy was comparable with left pneumonectomy (hazard ratio [HR], 1.35; 95% CI, 0.95-1.91; P = .09) and significantly worse than left (HR, 0.40; 95% CI, 0.29-0.56; P < .0001) or right (HR, 0.43; 95% CI, 0.31-0.59; P < .0001) lobectomy. Bilobectomy was associated with a survival advantage compared with right pneumonectomy (HR, 2.54; 95% CI, 1.72-3.74; P < .0001). Thirty-day morbidity was higher for bilobectomy compared with lobectomy, and upper bilobectomy had a significant unadjusted 30-day mortality advantage compared with lower bilobectomy (98.3% vs 97%, P = .04).

The morbidity and mortality of bilobectomy is significantly worse than lobectomy and is comparable with left pneumonectomy. The addition of middle lobectomy to a pulmonary resection is not without risk and should be carefully considered during preoperative risk stratification.