BackgroundCombined subsegmental surgery (CSS) is considered to be a safe and effective resection modality for early-stage lung cancer. However, there is a lack of a clear definition of the technical difficulty classification of this surgical case, as well as a lack of reported analyzes of the learning curve of this technically demanding surgical approach.MethodsWe performed a retrospective study of single-port thoracoscopic CSS performed by the same surgeon between April 2016 and September 2019. The combined subsegmental resections were divided into simple and complex groups according to the difference in the number of arteries or bronchi which need to be dissected. The operative time, bleeding and complications were analyzed in both groups. Learning curves were obtained using the cumulative sum (CUSUM) method and divided into different phases to assess changes in the surgical characteristics of the entire case cohort at each phase.ResultsThe study included 149 cases, including 79 in the simple group and 70 in the complex group. The median operative time in the two groups was 179 min (IQR, 159-209) and 235 min (IQR, 219-247) p < 0.001, respectively. And the median postoperative drainage was 435 mL (IQR, 279-573) and 476 mL (IQR, 330-750), respectively, with significant differences in postoperative extubation time and postoperative length of stay. According to the CUSUM analysis, the learning curve for the simple group was divided by the inflection point into 3 phases: Phase I, learning phase (1st to 13th operation); Phase II, consolidation phase (14th to 27th operation), and Phase III, experience phase (28th to 79th operation), with differences in operative time, intraoperative bleeding, and length of hospital stay in each phase. The curve inflection points of the learning curve for the complex group were located in the 17th and 44th cases, with significant differences in operative time and postoperative drainage between the stages.ConclusionThe technical difficulties of the simple group of single-port thoracoscopic CSS could be overcome after 27 cases, while the technical ability of the complex group of CSS to ensure feasible perioperative outcomes was achieved after 44 operations.

Background In clinical practice, combined segmental resection (CSS) can avoid resection of multiple segments to preserve lung function. When two or more distant lung segments or subsegments of the same lobe present with a ground glass opacity (GGO) that meets the indications for sublobar resection, conventional CSS or wedge resection could not remove all the nodules, and lobectomy is performed in most of these patients. For these particular types of nodules, we perform a single lobe noncombined subsegmental resection, or “separated” precise subsegmentectomy, to preserve more lung tissue. This study was designed to initially assess the feasibility and safety of “separated” precise subsegmentectomy. Methods Selected cases of specific GGO were subjected to “separated” precise subsegmentectomy and the results of general clinical data, perioperative operative time, bleeding, length of stay, computed tomography (CT) review, lung function and its dynamic changes were collected and analyzed in these patients. Results “Separated” precise subsegmentectomy was performed in 12 patients and successfully completed. The median operation time, bleeding amount, and length of hospital stay were 96 min, 50 ml and 4 days, respectively. There was one case of pulmonary infection and one case of persistent air leakage, no death or pulmonary torsion, bronchopleural fistula and other pulmonary complications occurred. After 3 months, the median percentage of lung function retention was 91.7%, and the CT scan showed that the reserved lung tissue of 12 patients was well inflated and there was no obvious imaging manifestation of atelectasis. Conclusion “Separated” precise subsegmentectomy is a novel and safe surgical method that provides a more optimized way for patients with specific multiple nodules to preserve lung function. Further prospective large studies are needed to verify this finding.