Katsuyuki Suzuki

Spread Through Air Spaces Is a Prognostic Factor in Sublobar Resection of Non-Small Cell Lung Cancer

BACKGROUND Spread through air spaces (STAS) identified in lung cancer is considered to be a risk factor for recurrence after surgery. The purpose of this study is to clarify the prognostic impact of STAS in sublobar resections. METHODS We studied 514 patients with clinical stage IA cancers: 329 underwent lobectomies and 185 underwent sublobar resections. We assessed the prognostic impact of STAS in the cases with a sublobar resection for stage IA lung cancer versus the cases with a lobectomy. RESULTS STAS was found in 73 of 329 (22.2%) lobectomy cases and 31 of 185 (16.8%) sublobar resection cases. For overall survival, univariate analysis revealed that STAS was not a prognostic factor in the lobectomy group, but it was a significantly worse prognostic factor for the sublobar resection group in both univariate and multivariate analyses. For the recurrence-free rate, multivariate analysis showed STAS was not a risk factor in the lobectomy group, but it was a significant risk factor for the sublobar resection group in both univariate and multivariate analyses. Patients with STAS and sublobar resection had a significantly higher rate of pulmonary metastases than did patients with STAS and lobectomy (8 of 31 [25.8%] vs 6 of 73 [8.2%]). CONCLUSIONS STAS is a prognostic factor of poor outcomes for sublobar resection in patients with lung cancer. The worse prognosis for sublobar resection would be associated with STAS.

Hemorrhage of a pancreatic metastasis from lung adenocarcinoma after osimertinib therapy

Osimertinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). It is used as anti-cancer therapy in patients with EGFR-TKI sensitizing mutations and EGFR T790M mutations and is recommended for treatment of patients with EGFR T790M-positive advanced non-small cell lung cancer (NSCLC) after progression on first-line EGFR-TKIs or frontline treatment in EGFR mutation-positive (exon 19 deletion or L858R) advanced NSCLC (1,2). Common adverse effects of osimertinib are similar to other EGFR-TKIs and are generally mild in severity and reversible (1). Previous reports have suggested an association between gefitinib or erlotinib treatment and organ bleeding or tumor hemorrhage (3-8). But to date there have been no reports of a similar association between osimertinib and tumor hemorrhage. Herein, we report an unusual case of hemorrhage of a pancreatic metastasis from lung adenocarcinoma after osimertinib therapy.

Determination of the intersegmental plane using the slip-knot method

Background Visualization of intersegmental planes in the lung is desirable for precise anatomical lung segmentectomy. We developed the slip-knot method for creating inflation-deflation lines. This study aimed to assess relevant data for thoracoscopic segmentectomy performed using this method. Methods In the slip-knot method, the objective segmental bronchus is looped with a monofilament thread. One end of the thread is then pulled during temporary bilateral ventilation, causing the knot to slip toward the bronchus. Thereafter, bronchial ligation is tightened to block the outflow of segmental air, ensuring that the segment remains expanded while the other reserved segments collapse on resumption of unilateral ventilation. Data from 221 patients who underwent thoracoscopic pulmonary segmentectomy between 2010 and 2016 were analyzed. Results A total of 147 patients (67%) were indicated for the slip-knot method, and 74 cases (33%) were non-adaptive cases. Ninety six percent of 147 cases were well adapted to the slip-knot method, which allowed us to obtain good inflation-deflation line images to determine the intersegmental plane. The mean operative time was 171±51 min (range, 71-367 min). The mean duration of chest tube insertion was 1.5±1.2 days (range, 1-7 days). Three cases (2.0%) had prolonged air-leakage and one (0.7%) case had readmission for late air-leakage. Conclusions Our method enables determination of anatomical intersegmental planes using only one monofilament thread, thus facilitating thoracoscopic pulmonary anatomical segmentectomy.

How to demarcate intersegmental plane with resected-segments inflation method using the slip knot technique in thoracoscopic anatomic segmentectomy

Intersegmental demarcation line on the surface of the visceral pleura could not be found at thoracoscopic findings. The resected segments inflation (RSI) method has been reported as a useful technique for visualizing the intersegmental demarcation line during segmentectomy. Thoracoscopic anatomic segmentectomy is performed as follows: firstly, the pulmonary vein and artery of the segment planned for resection are dissected from the hilum in order to isolate the segmental bronchus located behind the pulmonary artery. Secondly, a monofilament non-absorbable suture is passed through the segmental bronchus, and a slip-knot is made outside the thorax. Thirdly, bilateral lung ventilation with pure oxygen is conducted. When the affected segment has inflated sufficiently, the slip knot suture is pulled and the segmental bronchus is ligated and collapse of the lung is made on reserved segments. Fourthly, as inflation of the affected segment and collapse of the reserved segments could be found, resection of intersegmental plane could be easily performed with the inflation-deflation line and the intersegmental pulmonary vein. If resected segmental bronchus could be identified, thoracoscopic segmentectomy with the slip-knot technique would be applicable. This slip-knot procedure is economical and is not need special instrument.

Swine model for training surgeons in minimally invasive anatomic lung segmentectomy

BACKGROUND Despite the increasing demand for thoracoscopic lung segmentectomy, the appropriate training method is not well established. Therefore, we developed a swine model for anatomical thoracoscopic lung segmentectomy training. METHODS Three-month-old pigs, weighing 40 to 45 kg, were used in this model. Anterior segmentectomy of the left cranial lobe and segmentectomy of the most anterior left caudal lobe were performed under general anesthesia and differential ventilation. Participants from several institutions participated in this program, which included training lectures and surgical skill drills. RESULTS From 2010 to 2015, 33 pigs were used for the lung segmentectomy training with 51 trainees. Eight pigs were operated on using the hybrid approach, and 25 pigs were operated on using the complete thoracoscopic approach. Among 25 pigs in which the complete thoracoscopic approach was used, conversion to thoracotomy was required in 3 pigs, owing to hemorrhage in two and failure of differential ventilation in one. The no-touch method in supine position provided sufficient intersegmental delineation of 20 (76%) planes among 26 left anterior segmentectomies in the cranial lobe. CONCLUSIONS Our live swine model of anatomical thoracoscopic lung segmentectomy is considered a good choice for training surgeons on how to perform minimally invasive lung segmentectomy in humans.