須田 隆

BACKGROUND: Lung cancer frequently occurs in lungs with background idiopathic interstitial pneumonias (IIPs). Limited resection is often selected to treat lung cancer in patients with IIPs in whom respiratory function is already compromised. However, accurate surgical margins are essential for curative resection; underestimating these margins is a risk for residual lung cancer after surgery. We aimed to investigate the findings of lung fields adjacent to cancer segments affect the estimation of tumor size on computed tomography compared with the pathological specimen. METHODS: This analytical observational study retrospectively investigated 896 patients with lung cancer operated on at Fujita Health University from January 2015 to June 2020. The definition of underestimation was a ≥10 mm difference between the radiological and pathological maximum sizes of the tumor. RESULTS: The lung tumors were in 15 honeycomb, 30 reticulated, 207 emphysematous, and 628 normal lungs. The ratio of underestimation in honeycomb lungs was 33.3% compared to 7.4% without honeycombing (P=0.004). Multivariate analysis showed that honeycombing was a significant risk factor for tumor size underestimation. A Bland-Altman plot represented wide 95% limits of agreement, -40.8 to 70.2 mm, between the pathological and radiological maximum tumor sizes in honeycomb lungs.

We report a lateral approach using the grasping technique for uniportal major lung resection. Grasping dissected tissue with grasping forceps enables the dissected surface to be three-dimensionally dissected from important organs, such as blood vessels, which, therefore, makes the procedure safe. Furthermore, there is an incision wound on the middle axillary line at the 6th intercostal space, and therefore, either the anterior or posterior side of the hilum can be easily observed, and a stapler can pass through all structures of the hilum easily.

OBJECTIVE: To determine whether robotic-assisted lobectomy (RAL) affects perioperative outcomes and long-term efficacy in non-small cell lung cancer (NSCLC) patients, compared with traditional video-assisted lobectomy (VAL). SUMMARY BACKGROUND DATA: RAL is a promising treatment for NSCLC. However, its efficacy has not been fully evaluated. METHODS: A single-center, open-labeled prospective randomized clinical trial was launched in May 2017 to compare the efficacy of RAL and VAL. By May 2020, 320 patients were enrolled. The perioperative results of RAL and VAL were compared. RESULTS: The 320 enrolled patients were randomly assigned to the RAL group (n = 157) and the VAL group (n = 163). Perioperative outcomes were comparable between the two groups, including the length of hospital stay (P = 0.76) and the rate of postoperative complications (P = 0.45). No perioperative mortality occurred in either group. The total amount of chest tube drainage (830 ml [IQR, 550-1130 ml] vs. 685 ml [IQR, 367.5-1160 ml], P = 0.007) and hospitalization costs ($12821 [IQR, $12145-$13924] vs. $8009 [IQR, $7014-$9003], P < 0.001) were significantly higher in the RAL group. RAL group had a significantly higher number of lymph nodes (LNs) harvested (11 [IQR, 8-15] vs. 10 [IQR, 8-13], P = 0.02), higher number of N1 LNs (6 [IQR, 4-8] vs. 5 [IQR, 3-7], P = 0.005), and more LN stations examined (6 [IQR, 5-7] vs. 5 [IQR, 4-6], P < 0.001). CONCLUSIONS: Both RAL and VAL are safe and feasible for the treatment of NSCLC. RAL achieved similar perioperative outcomes, together with higher LN yield. Further follow-up investigations are required to evaluate the long-term efficacy of RAL. (ClinicalTrials.gov identifier: NCT03134534).

INTRODUCTION: Thoracoscopic lobectomy for primary lung cancer is performed at many institutions. However, few reports are available on postoperative prognosis for progressive stages. In 2004, we adopted lobectomy by video-assisted thoracoscopic surgery (VATS), which would be applicable to the clinical stages up to stage IIIA. This study reports long-term outcomes of surgery for primary lung cancer at several stages, including IIIA. METHODS: We compared the long-term outcomes of 315 VATS cases with those of 159 open thoracotomy cases. RESULTS: The overall 5-year survival rate was 78.1% for the VATS group and 61.9% for the open thoracotomy group. A statistically significant difference between the survival curves of the two groups was observed (P = .001). When analyzing the survival curves for both groups by pathological (p) stage, significant differences were observed for p-stages IB and IIIA, with the VATS group producing better results than the open thoracotomy group. CONCLUSION: The long-term outcomes of patients with primary lung cancer at our institution were more favorable in the group undergoing VATS lobectomy than in the group undergoing open thoracotomy.

症例は36歳,男性.健康診断で胸部異常陰影を指摘され受診した.胸部CT上,両側下葉優位に小葉中心性の粒状影を認めた.診断目的に気管支鏡検査を施行したが確定診断に至らず,胸腔鏡下肺生検を施行した.病理組織学的には,肺胞壁隔壁に沿って分岐するような形態を示す径0.5mm大の石灰沈着と脂肪髄を伴う骨組織を認めたため,樹枝状肺骨化症と診断した.本疾患は,肺組織に異所性の骨化巣を生じる非常に稀な疾患であり,自覚症状に乏しく剖検で発見されることが多い.また,長期に経過観察された報告はほとんどなく予後も明らかではない.本症例は,術後4年を経過して画像上の変化なく生存中である.(著者抄録)

OBJECTIVES: The aim of the present study was to examine some initial results and learning curves concerning subxiphoid single-port thymectomy (SSPT), thereby clarifying the safety of this surgical approach and describing the precautions for adopting it. METHODS: From March 2011 to August 2019, a total of 203 patients underwent thymectomy for either anterior mediastinal tumours or myasthenia gravis at Fujita Health University Hospital. Of these 203 patients, 147 patients who had undergone SSPT were selected as participants for the present study. RESULTS: Of the 147 cases, transition to a different approach was required in three (2.0%) cases: two (1.3%) cases transitioned to median sternotomy, whereas one (0.7%) case transitioned to the side chest trans-intercostal approach. The two cases that transitioned to median sternotomy were the second cases for different operators after they began performing this technique. There were six (4.0%) cases with complications and no deaths. The operation time cumulative summation learning curve analysis revealed that the curves descended from the 38th case. In the 83 cases handled by one surgeon, the learning curves descended from the 31st case. CONCLUSIONS: SSPT is a safe modality with few complications and no associated cases of mortality reported. Operators are required to experience 31-38 cases until the operation time for SSPT was stabilized. Special care should be exercised to prevent vascular damage in the vicinity of the innominate veins during the early stages after SSPT introduction.

Subxiphoid uniportal bilateral lung wedge resection, in which all manipulations are performed via a 3-cm wound positioned below the xiphoid process, can be performed in the supine position without the patient having to change positions. It also enables one-stage bilateral lung resection. We report the surgical procedure and initial results of subxiphoid uniportal bilateral lung wedge resection. A 3-cm transverse incision was made 1 cm caudally below the xiphoid process. A port for uniportal surgery was inserted. After CO2 insufflation at 8 mmHg, the lung was grasped and lifted with bent grasping forceps, and by bending the tip of a stapler, the surgeon resected the affected portion of the bilateral lungs. In this approach, there is one incision, no intercostal nerve damage and bilateral surgery can be performed in the same procedure; therefore, the technique may have the benefit of lesser invasiveness for the patient. Furthermore, a detailed comparison of subxiphoid uniportal bilateral lung wedge resection with the one-stage lateral intercostal approach with a larger subject sample is needed.

In recent years, uniportal video-assisted thoracoscopic surgery, which performs all surgical procedures from 1 wound, has been spreading for the purpose of performing less invasive surgery. The uniportal surgery requires a device because it interferes with instruments, but is a surgical technique that is cosmetically excellent and can be expected to reduce postoperative pain. This new minimally invasive surgical technique is now widely spread, especially in Asia and Europe. In addition, uniportal surgery using the subxiphoid approach has attracted attention. This method has an advantage that intercostal neuropathy does not occur because it does not pass through the intercostal space, and is a useful method for patients. These uniportal surgery is expected to be further developed as a new minimally invasive surgery. In the future, it is necessary to develop more operable devices and instruments, including robot systems, and to prove the usefulness of uniportal surgery.

Background: This study aimed to investigate the initial results of an endoscopic surgical approach for the treatment of intramediastinal ectopic parathyroid adenoma and to evaluate the effectiveness of a single-incision resection using the subxiphoid approach. Methods: Five cases of patients (1.89%) were diagnosed with ectopic mediastinal parathyroid tumor and underwent resection from 2008 to 2017 in Fujita Health University Hospital. They were retrospectively analyzed. Results: Four patients underwent single-port mediastinal tumor resection using the subxiphoid approach and 1 patient underwent multi-port mediastinal tumor resection using the lateral thoracic approach. The operation time was 134±83.52 min, and the amount of blood loss was 81.8±173.41 mL. The rate of conversion to thoracotomy was 0%, and no intraoperative or postoperative complications were observed. The amount of postoperative oral analgesics was 112.83±209.12 tablets, and their administration period was 561.6±1,229.5 days. The length of hospital stay was 4±2.35 days, and the duration of chest tube drainage was 1.33±1.95 days. The patient who underwent multi-port mediastinal tumor resection using the lateral thoracic approach reported postoperative pain. Serum calcium levels decreased from 10.56±1.52 mg/dL preoperatively to 8.96±0.5 mg/dL postoperatively, and serum phosphorous levels increased from 2.84±0.42 mg/dL preoperatively to 3.6±0.51 mg/dL postoperatively. Intact-PTH hormone levels decreased from 221±169.84 pg/dL preoperatively to 70.2±44.28 pg/dL postoperatively. No recurrence of hyperparathyroidism has been observed in any patient. Conclusions: The single-incision mediastinal tumor resection via the subxiphoid approach, without going through the intercostal space, is considered as a useful endoscopic surgical approach for the treatment of mediastinal ectopic parathyroid adenomas due to the limited occurrence of post-thoracotomy pain syndrome and the superior esthetic outcomes associated with the procedure as compared to thoracotomy and median sternotomy.

The advantages of robot-assisted surgery include true 3-dimensional imaging with binocular glasses and the use of multiarticular forceps that allow the performance of high-precision operations. This report described the surgical techniques of robot assisted major pulmonary resection and subxiphoid robot-assisted thymectomy. Future developments in the field of robotic engineering will lead to the creation of systems that allow for more advanced surgical techniques. We hope that robotic assisted surgery will be safely introduced into many medical facilities.

Background: We have used a promising, minimally invasive thoracoscopic technique of extended thymectomy for patients with myasthenia gravis (MG). The aim of this study was to report our promising technique, a modified single-port trans-subxiphoid approach (MTXA) and to compare perioperative outcomes and effects on MG between our approach and sternotomy. Methods: We retrospectively reviewed records of all patients undergoing extended thymectomy for MG and/or thymoma between January 1, 2010 and December 31, 2016. The patients were divided into the MTXA group and Sternotomy group. Results: Of the 50 consecutive patients undergoing extended thymectomy for MG, finally, 13 patients undergoing our MTXA extended thymectomy technique were compared with 20 patients undergoing extended thymectomy via sternotomy. Intraoperative blood loss, postoperative length of stay, and C-reactive protein value on postoperative day 1 were significantly more favorable in the MTXA group than the Sternotomy group (P<0.0001, P=0.0040 and P=0.0073, respectively). Furthermore, no significant differences in the frequency of patients with improvement of their Quantitative Myasthenia Gravis score and/or MG-Activities of Daily Living scale, decrease in the serum level of acetylcholine receptor antibody, and dose reduction of oral prednisone were seen between the two groups. Conclusions: Our approach to extended thymectomy might be more favorable than sternotomy in patients with MG.

In recent years, the subxiphoid approach has been used to avoid intercostal nerve damage in the field of thoracic surgery. A subxiphoid single-port thymectomy does not require sternotomy; it is associated with lesser pain because there is no intercostal nerve damage; and it provides excellent cosmetic outcomes. Furthermore, in 2014, the author and colleagues reported synchronous resection of bilateral pulmonary metastases by bilateral lung-wedge resection for bilateral metastatic lung tumors with a single 3-cm subxiphoid incision. In this method, a bilateral lung-wedge resection is performed synchronously without an intercostal approach and, thus, does not cause intercostal nerve damage and excels in aesthetic outcomes.

<p>症例は59歳の男性．健診で胸部異常陰影を指摘され，原発性肺癌の疑いで当院紹介となった．胸部X線写真上，右胸心と左中肺野に径3.0×2.5 cmの腫瘤影を認めた．胸腹部CTでは，両肺とも2分葉で，気管支と肺動脈の形態は左右反転していた．また，右側大動脈弓，右胸心，上大静脈遺残，多脾症，対称肝，上腸間膜回転異常および膵尾部低形成を認めた．内臓錯位症例に発症した左中葉肺癌c-T2aN0M0 stageIBと診断した．3D-CTを含む画像により解剖学的位置関係を十分に評価した上で，胸腔鏡下左肺中葉切除術＋リンパ節郭清を施行した．しかし，術中に左反回神経を同定できず，一部の縦隔リンパ節はサンプリングに留めた．</p><p>内臓錯位症候群は，血管・気管支走行異常や合併奇形を認めることが多いため，総合的に術式決定することが重要であり，3D-CTを含む十分な術前精査を行っておくことが肝要である．</p>

<p>症例は55歳女性．胸部CT上，心膜と肺動脈幹左側に接する径11.2×9.3 cmの前縦隔腫瘍を認め，胸部造影MRI上，腫瘍の心膜と肺動脈幹への浸潤が疑われた．CTガイド下針生検により胸腺腫WHO分類type ABと診断．完全切除は困難と判断し，腫瘍縮小効果を期待してステロイドパルス療法を施行したところ，腫瘍は径8.5×6.2 cmまで縮小，肺動脈幹との境界が明瞭となり左胸水は消失した．ステロイドパルス療法開始28日後に胸骨正中切開による胸腺胸腺腫摘出術を施行した．術中，腫瘍の左肺上葉と心膜への癒着を認めたが，左肺および心膜合併切除により完全切除が可能であった．術前ステロイドパルス療法により著明な腫瘍縮小効果を認め，完全切除可能と判断するに至った胸腺腫の1例を経験した．抗悪性腫瘍薬よりも副作用の少ないステロイドパルス療法は，局所進行胸腺腫において，完全切除の可否判断のための有用なツールとなり得る．</p>

BACKGROUND: The objective of this study was to assess the preoperative serum carcinoembryonic antigen (CEA) level in patients with clinical stage IA non-small cell lung cancer (NSCLC) and to evaluate its clinical significance. METHODS: Between January 2005 and December 2014, a total of 378 patients with clinical stage IA NSCLC underwent complete resection with systematic node dissection. The survival rate was estimated starting from the date of surgery to the date of either death or the last follow-up by the Kaplan-Meier method. Univariate analyses by log-rank tests were used to determine prognostic factors. Cox proportional hazards ratios were used to identify independent predictors of poor prognosis. Clinicopathological predictors of lymph node metastases were evaluated by logistic regression analyses. RESULTS: The 5-year survival rate of patients with an elevated preoperative serum CEA level was significantly lower than that of patients with a normal CEA level (75.5% vs. 87.7%; P=0.02). However, multivariate analysis did not show the preoperative serum CEA level to be an independent predictor of poor prognosis. Postoperative pathological factors, including lymphatic permeation, visceral pleural invasion, and lymph node metastases, tended to be positive in patients with an elevated preoperative serum CEA level. In addition, the CEA level was a statistically significant independent clinical predictor of lymph node metastases. CONCLUSIONS: The preoperative serum CEA level was not an independent predictor of poor prognosis in patients with pathological stage IA NSCLC but was an important clinical predictor of tumor invasiveness and lymph node metastases in patients with clinical stage IA NSCLC. Therefore, measurement of the preoperative serum CEA level should be considered even for patients with early-stage NSCLC.

The "da Vinci Surgical System" is a robotic surgical system that utilizes multi-jointed robotic arms and a high-resolution three-dimensional video-monitoring system. We report on the state of transition from video-assisted thoracoscopic surgery (VATS) to robotic pulmonary surgery, the surgical outcomes of robotic surgery compared to VATS, and the future of robotic surgery. Surgery utilizing the da Vinci Surgical System requires a console surgeon and assistant who have been certified by Intuitive Surgical, Inc., the system manufacturer. On the basis of the available medical literature, a robotic lobectomy has a learning curve that extends over approximately 20 cases for a surgeon who has mastered VATS. Surgery using the da Vinci System is safe, is associated with lower morbidity and mortality rates than thoracotomy, leads to shorter postoperative hospital stays, and ensures improved postoperative quality of life. Currently, no prospective studies comparing it to VATS have been conducted. The various studies that have compared robotic surgery and VATS have reported different results. At the present time, the benefits to patients of robotic surgery compared to VATS remain unclear. Areas in which robotic surgery may be superior to VATS include the superior operability of robotic surgery that improves safety and decreases the incidence of complication. To show that the costly robotic surgery is superior to VATS, prospective multicenter randomized studies need to be conducted. The da Vinci robot-assisted surgical system has already been highly evaluated for its safety, with recent studies reporting satisfactory outcomes. It remains necessary to verify whether the benefits to patients justify the higher cost of robotic surgery. Future developments in the field of robotic engineering will likely lead to the creation of systems that are even less invasive and allow for more advanced surgical techniques.

Currently, surgical techniques that are less invasive than conventional median sternotomy are used for thymectomy in the treatment of myasthenia gravis and anterior mediastinal tumors as no sternal incision is required. We reported on a subxiphoid single-port thymectomy using CO2 insufflation, which has the following advantages: (I) the field of view offered by the camera scope inserted from the midline of the body helps confirm the location of the superior pole of the thymus and bilateral phrenic nerves; (II) there is minimal pain and no intercostal neuropathy occurs as intercostal spaces are not traversed; and (III) cosmetic outcomes are excellent. However, a drawback of this approach is that it requires familiarity with the single-port surgical procedure. Various surgical modifications have been suggested for the subxiphoid approach, which we currently use for thymectomy. These include subxiphoid single-port thymectomy; subxiphoid dual-port thymectomy (DPT) wherein an additional lateral thoracic intercostal port is added, which is used for more complicated surgeries; and subxiphoid robotic thymectomy using the da Vinci Surgical System. Here we report on these techniques. A subxiphoid approach in thymectomy is advantageous to patients as it minimizes or avoids the occurrence of intercostal neuropathy. Moreover, a subxiphoid approach provides the surgeon with a good field of view of the cervical region and helps confirm the location of the bilateral phrenic nerves. Therefore, thymectomy using a subxiphoid approach should be considered an option for a minimally invasive surgery.