Split-lobe resections versus lobectomy for lung carcinoma of the left upper lobe: a pair-matched case-control study of clinical and oncological outcomes

Abstract

Objectives: To compare left upper split-lobe procedures, being upper trisegmentectomy and resection of the lingula, with left upper lobectomy for surgical treatment of lung carcinoma originating from the left upper lobe.

Methods: A pair-matched control study comparing the clinical and oncological outcomes of 22 consecutive patients after left upper split-lobe resections with those of 44 pair-matched controls that received left upper lobectomy for non-small-cell lung carcinomas. The control group was matched 1:2 for tumour diameter, histology, nodal status and patient age. In both groups, diagnosis and surgical treatment adhered to the principles of tissue-based preoperative mediastinal staging, intraoperative systematic nodal dissection, and gross surgical margins equal to the tumour diameter or at least 2 cm, a sufficient preoperative pulmonary function given.

Results: As intended by the study design, the split-lobe and lobectomy groups had similar median tumour diameters of 22.5 (range, 11-63) and 25 (range, 7-68) mm, respectively (P = 0.98), identical histologies (45.5% adenocarcinoma, 4.5% adenocarcinoma in situ, 45.5% squamous cell carcinoma and 4.5% neuroendocrine carcinoma) and identical pN stages (pN0 77.3%, pN1 9.1%, pN2 9.1% and ypN0 4.5%). In the split-lobe group, a lower preOP forced expiratory volume in one second (median 2.0 vs 2.3 l), a higher comorbidity (median Charlton score of 3 vs 2) and a preponderance of video-assisted thoracoscopy procedures (63.6 vs 27.3%) were prevalent (all P < 0.05). There were no significant outcome differences detected, neither with regard to the postoperative clinical course assessed by intra- and postoperative complications, operation time, tissue margins, duration of drainage and hospital stay and 30-day mortality, nor with regard to 5-year overall (0.89 vs 0.81, P = 0.90).

Conclusions: Left upper lobectomy might be an overtreatment for selected cases of lung carcinoma whose resection by a split-lobe procedure produces adequate margins and a complete lymphadenectomy. Tumour diameters exceeding 2 cm, nodal involvement and previous neoadjuvant treatment do not necessarily exclude this option for selected patients under the condition of a meticulous nodal dissection. In this context, we would like to suggest a translational research of the split-lobe concept to other large pulmonary lobes.

Keywords: Left upper lobe division; Lingula; Lung carcinoma; Lung resection; Pulmonary segmentectomy; Sublobar resection; Trisegmentectomy.