須田 康一

BACKGROUND: Minimally invasive surgery for gastric cancer (GC) has gained widespread use as a safe curative procedure especially for early GC. AIM: To determine risk factors for postoperative complications after minimally invasive gastrectomy for GC. METHODS: Between January 2009 and June 2019, 1716 consecutive patients were referred to our division for primary GC. Among them, 1401 patients who were diagnosed with both clinical and pathological Stage III or lower GC and underwent robotic gastrectomy (RG) or laparoscopic gastrectomy (LG) were enrolled. Retrospective chart review and multivariate analysis were performed for identifying risk factors for postoperative morbidity. RESULTS: Morbidity following minimally invasive gastrectomy was observed in 7.5% of the patients. Multivariate analyses demonstrated that non-robotic minimally invasive surgery, male gender, and an operative time of ≥ 360 min were significant independent risk factors for morbidity. Therefore, morbidity was compared between RG and LG. Accordingly, propensity-matched cohort analysis revealed that the RG group had significantly fewer intra-abdominal infectious complications than the LG group (2.5% vs 5.9%, respectively; P = 0.038), while no significant differences were noted for other local or systemic complications. Multivariate analyses of the propensity-matched cohort revealed that non-robotic minimally invasive surgery [odds ratio = 2.463 (1.070-5.682); P = 0.034] was a significant independent risk factor for intra-abdominal infectious complications. CONCLUSION: The findings showed that robotic surgery might improve short-term outcomes following minimally invasive radical gastrectomy by reducing intra-abdominal infectious complications.

食道悪性腫瘍に対するロボット支援手術について以下の項目で概説した。1)内視鏡手術支援ロボットの歴史、2)ロボット支援下食道悪性腫瘍手術の現状、3)当科におけるロボット支援下食道悪性腫瘍手術、3)ロボット支援下手術の今後の展望。ロボット支援下食道悪性腫瘍手術は世界的にみても普及しているとは言いがたく、ある程度まとまった症例の報告例は少ない。当科ではロボットのもつ高い潜在能力に着目し、国内でいち早く2008年12月にda Vinci Surgical Systemを導入した。さらに近年では、頭頸部外科領域で有用性が示されている神経刺激装置を使用した術中神経刺激モニタリングをロボット手術に取り入れることにより、さらなる合併症軽減にむけて取り組んでいる。今後の手術施行数の増加に伴い、ロボット手術の有用性、従来の胸腔鏡手術との優越性を支持するエビデンスの集積が期待される。

BACKGROUND: Esophagectomy is associated with a high risk of postoperative complications, and the respiratory complications are the most common. Therefore, stratification of patients based on preoperative risk factors is essential. This study aimed to identify the risk of postoperative pneumonia (POP) based on the preoperative factors and determine the optimal perioperative surgical management strategy. METHODS: This retrospective study involved 207 patients who underwent esophagectomy. The patients were divided into two groups, namely, with POP and without POP. To identify the risk factors for POP, the pre- and perioperative characteristics were analyzed. A receiver operating characteristics curve was used to determine a cutoff value of 2.40 L for the forced expiratory volume in 1 s (FEV1.0) and the cohort was divided into a high- and low-FEV1.0 group. A second analysis was then performed to determine the optimal surgical management for patients at a high risk for POP. RESULTS: POP occurred in 45 (21.7%) patients. A multiple logistic regression analysis showed that FEV1.0 was significantly lower in the POP (+) group (P = 0.020); thus, a low FEV1.0 was found to be a risk factor for POP. Multiple logistic regression analysis showed that open thoracotomy was a significant risk factor for POP in low FEV1.0 patients (P = 0.013). CONCLUSIONS: A low FEV1.0 and an open thoracotomy are risk factors for POP. Therefore, patients with low FEV1.0 should be managed carefully and video-assisted thoracic surgery should be considered.

BACKGROUND: Although chemotherapy is a core treatment for esophageal cancer, some patients develop drug resistance. Gene screening with transposons (i.e. mobile genetic elements) is a novel procedure for identifying chemotherapy-resistant genes. Transposon insertion can randomly affect nearby gene expression. By identifying the affected genes, candidate genes can be found. The present study aimed to identify cisplatin (CDDP)/5-fluorouracil (5-FU)-resistant genes in in vitro human esophageal squamous cell carcinoma with transposons. METHODS: After establishing transposon-tagged cells, we obtained CDDP/5-FU-resistant colonies. A polymerase chain reaction and sequencing were used to identify the transposon inserted site and candidate CDDP/5-FU resistant genes. Focusing on one candidate gene, we confirmed CDDP/5-FU resistance by comparing the IC50 between drug-resistant and wild-type cells. Furthermore, we investigated gene expression by a real-time polymerase chain reaction. Finally, we mediated the candidate gene level with small interfering RNA to confirm the resistance. RESULTS: Thirty-nine candidate genes for CDDP/5-FU resistance were identified. Nineteen were for CDDP resistance and 27 were for 5-FU resistance. Seven genes, THUMP domain-containing protein 2 (THUMPD2), nuclear factor interleukin-3-regulated protein (NFIL3), tyrosine-protein kinase transmembrane receptor 2 (ROR2), C-X-C chemokine receptor type 4 (CXCR4), thrombospondin type-1 domain-containing protein 2 (THSD7B) alpha-parvin (PARVA) and TEA domain transcription factor 1 (TEAD1), were detected as candidate genes in both colonies. Regarding THUMPD2, its expression was downregulated and knocking down THUMPD2 suggested drug resistance in both drugs. CONCLUSIONS: Thirty-nine candidate genes were identified with transposons. The downregulation of THUMPD2 was suggested to play a role in multidrug resistance in in vitro esophageal squamous cell carcinoma.

A 69-year-old woman, who complained of loss of appetite, was admitted to our hospital and diagnosed with clinical Stage Ⅳgastric cancer and paraaortic lymph node metastases(cT4aN3M1[#16b1LYM], cStage Ⅳ). She underwent 2 cycles of SP therapy(combination of S-1 and CDDP). A partial response of the primary tumor was noted, with no distant metastases, except for the paraaortic lymph nodes. She underwent robotic total gastrectomy with D2 plus paraaortic lymph node dissection. Histopathology showed no residual tumor cells in the stomach or lymph nodes. Postoperatively, the patient underwent 3 cycles of SOX therapy(combination of S-1 and oxaliplatin)and survived for over 6 postoperative months, with no recurrences. For advanced gastric cancers with paraaortic lymph node dissection with no evidences of other distant metastases, gastrectomy with paraaortic lymph node dissection combined with chemotherapy could be a therapeutic option to achieve R0 resection.

＜文献概要＞患者は74歳,男性.41歳時,進行胃癌に対し開腹胃全摘を行った.経過観察中に表在型食道癌を認め,内視鏡的切除を施行した.病理診断はpT1b(SM2),ly0,v0であったが,本人希望で追加治療なしで経過観察した.術後3ヵ月のCT検査で肝門部に18mmのリンパ節を認め,PET-CT検査で同部だけにFDG集積を認めた.治療方針を決めるうえで病理学的診断が必要と判断し,手術を施行した.初回手術時に剥離操作が及んでいない部位を辿り,比較的容易に腹腔鏡下にリンパ節を切除し,食道癌リンパ節再発と診断した.これまで開腹既往例で腹腔鏡下に肝門部リンパ節生検を行った報告はなく,若干の文献的考察を加えて報告する.

BACKGROUND: This study aimed to clarify the relationship between frailty and postoperative outcomes of laparoscopic gastrectomy for old-old patients with resectable gastric cancer. METHODS: The study retrospectively analyzed 96 consecutive patients (age ≥ 80 years) who had undergone R0 resection by laparoscopic gastrectomy for gastric cancer between 2006 and 2012. The patients were retrospectively scored using the clinical frailty scale (CFS) and categorized based on their scores (1-2, 3-4, and 5-7). Postoperative complications, 5-year survival rate, risk factors for morbidity, and prognosis were analyzed. RESULTS: The morbidity rate for Clavien-Dindo grades 2 or higher and 3a or higher were respectively 27.1% and 12.5%. Operative complications, especially systemic complications, were positively associated with an increase in CFS scores (p = 0.026). The overall 5-year survival rate was 59.8%, and the 5-year survival rates for those with a CFS score of 1-2, 3-4, and 5-7 were respectively 70.9%, 59.8%, and 35.1%. Specifically, the prognosis for the patients with a CFS score of 5-7 with stage 2 or 3 disease was significantly worse than for those with a lower CFS score (p = 0.009). The multivariate analysis showed that a total gastrectomy or blood loss of 200 g or more was a significant risk factor for morbidity (both p = 0.004), and that the independent risk factors for overall survival were a CFS score of 5-7 (p = 0.006), a body mass index lower than 18.5 kg/m2 (p = 0.039), and morbidity (grade ≥ 3a; p = 0.002). CONCLUSIONS: Frailty has a great impact on operative morbidity and prognosis in the elderly, and the CFS score could be a promising prognostic predictor, especially for frail patients with advanced gastric cancer.

＜文献概要＞ポイント ◆残胃の癌の手術では,初回胃切除後の癒着,再建による解剖学的変化を考慮して,手術手順を症例ごとに工夫する必要がある.◆内視鏡外科手術は,水平視や拡大視による良好な視野を活用した,手前から奥,内から外の操作を得意とする.◆網嚢左界,膵下縁,右横隔膜脚と尾状葉の間に癒着が比較的緩やかな部位があることが多い.

BACKGROUND: The surgical Apgar score (SAS) has been a useful predictor of postoperative complications in several types of cancer. However, there are few reports about the correlation of SAS and esophageal cancer. This study aimed to examine the utility of SAS as a predictor of major complications, particularly anastomotic leakage, in patients who underwent transthoracic esophagectomy, and investigate the correlation between SAS and patient prognosis. METHODS: This is a single-center, retrospective observational study. A total of 190 patients who underwent esophagectomy for esophageal cancer in 2012-2016 were reviewed to find the correlation between SAS and postoperative complications (Clavien-Dindo classification III or higher). SAS was calculated based on intraoperative estimated blood loss, lowest mean arterial pressure, and lowest heart rate. Major complications included anastomotic leakage, respiratory, cardiac, recurrent nerve palsy, chylothorax, and other complications. We also reviewed how SAS was correlated with 3 year overall survival (OS) and recurrence-free survival (RFS). A high SAS was defined as ≥ 6, and a low SAS as < 6. RESULTS: On univariate analysis, SAS showed a statistical significance in all major complications and anastomotic leakage. On multiple logistic regression analysis, a low SAS was detected as a risk factor of the major complications and anastomotic leakage, with a significant difference. Moreover, we conducted survival analysis with SAS; however, we could not detect that a low SAS had a negative impact on OS and RFS. CONCLUSIONS: A low SAS can be a predictor of postoperative complications, especially anastomotic leakage. However, SAS was not correlated with OS or RFS.

BACKGROUND: Cervical esophageal cancer (CEC) patients whose larynx function cannot be preserved often undergo chemoradiotherapy, whereas those with residual or recurrent lesions undergo a pharyngo-laryngo-esophagectomy (PLE); however, some need to undergo a pharyngolaryngectomy with total esophagectomy (PLTE) for synchronous or metachronous esophageal cancer. We retrospectively evaluated the relationship between preoperative irradiation (or the extent of esophageal resection) and postoperative endocrine complications in CEC, including hypothyroidism and hypoparathyroidism. METHODS: The cancers of 35 (5.4%) of 678 esophageal cancer patients with esophagectomy treated in 2000-2017 were CECs. We also analyzed the 17 cases of CEC patients who underwent PLE with thyroid lobectomy-11 with irradiation before PLE and 6 without irradiation. Seven patients underwent a PLTE. RESULTS: Hypothyroidism and hypoparathyroidism occurred in 14 and 12 patients, respectively. The hypothyroidism rate was significantly higher in patients with irradiation versus those without irradiation (100% vs. 50%; p = 0.010), and the hypoparathyroidism rate was significantly higher in the PLTE versus non-PLTE patients (100% vs. 50%; p = 0.026). The mean levothyroxine dosage was 1.60 μg/kg/day in the PLE patients post-irradiation. CONCLUSIONS: Irradiation appears to be a risk factor for hypothyroidism after PLE with thyroid lobectomy, while PLTE might have some effect on hypoparathyroidism. Due to vocal function loss, PLE patients may experience symptoms from endocrine complications. Levothyroxine treatment soon after PLE for post-irradiation patients and patients requiring as-needed calcium or vitamin D supplementation based on biochemical hypocalcemia for PLE (especially PLTE), may be effective in preventing symptomatic endocrine complications.

近年、腹腔鏡下膵頭十二指腸切除術(LPD)やロボット支援下膵頭十二指腸切除術(RPD)などの低侵襲膵頭十二指腸切除術(MIPD)が導入されつつある。しかし、MIPDは狭いワーキングスペースでの血管処理や動作制限を伴う膵空腸吻合などにおいて開腹下膵頭十二指腸切除術(OPD)以上に高難度で発展途上の術式である。当科では2008年よりLPDを20例、2009年よりRPDを20例に実施し、その過程で切除と血管処理においてはSemi-derotation technique、膵空腸吻合においてはWrapping double mattress anastomosis(Kiguchi-method)等の手技の工夫で術式の定型化を図ってきた。定型化後のLPD 13例、RPD 8例では共にISGPF grade B以上の膵液瘻(CR-POPF)は認めなかった。現時点でLPDとRPDの優劣は不明であるが、今後RPDにおける課題が克服されれば、より高難度な症例でRPDの優位性が発揮されるものと期待される。(著者抄録)

BACKGROUND: Although some predictive factors of long-term survival after a distal gastrectomy for gastric cancer have been reported, only few studies have predicted long-term outcomes based on preoperative parameters. We aimed to evaluate the reliability of perioperative risk calculator for predicting overall survival (OS) after distal gastrectomy in patients with gastric cancer. METHODS: Overall, 337 patients (225 males, 112 females) who had undergone a distal gastrectomy for gastric cancer at the Keio University Hospital, Tokyo, Japan, between January 2009 and December 2013 were enrolled in this study. We investigated the reliability of a risk calculator for the prediction of OS. RESULTS: In multivariate analysis, the risk models for operative mortality and 30-day mortality were identified as predictors of death. Time-dependent receiver operating characteristics (ROC) curve analysis indicated that the estimated area under the curve (AUC) value of the risk model for operative mortality was > 0.870 during the first postoperative 3 years. We set optimal cutoff values of the risk model operative mortality for OS using the Cutoff Finder online tool. The cutoff values of 4.117% were significant risk factors of death. Similar results were observed in the external validation set. CONCLUSIONS: We elucidated the associations among risk calculator values and OS rates of patients with gastric cancer. Time-dependent ROC curve analysis suggested that the AUC value of the risk model for operative mortality was high, indicating that this risk calculator would be useful for not only short-term outcomes, but also long-term outcomes.

＜文献概要＞ポイント ◆ロボット支援下胃切除は胃癌に対する腹腔鏡下手術に伴う術後合併症を有意に軽減する可能性が示唆され,2018年4月から保険収載された.◆学会指針や保険診療の要件を遵守し,ロボットの特性を熟知したうえで,安全に導入することが望まれる.◆外科医,麻酔科医,看護師,臨床工学技士などによる&quot;ロボット手術チーム&quot;で取り組むことが重要である.

BACKGROUND: Based on the sentinel node (SN) concept, function-preserving surgery with SN basin dissection (SNBD) can be performed for SN-negative early gastric cancers. Particularly, a resection area can be minimized when the SN basin and primary site are closely localized. The aim of this study was to compare probabilities of being candidates for local resection with SNBD based on tumor location among patients with early gastric cancer. METHODS: We retrospectively analyzed 358 patients who underwent surgery with SN mapping for gastric cancer in our institution from November 1999 to April 2014. The proportion of patients who had a localized single basin and the distributions of the SN basins and primary sites were investigated. Patients with single basin drainage excluding remote sentinel node basin were considered as candidates for local resection with SNBD. RESULTS: Of the 358 patients, 191 (53%) patients were considered eligible for local resection with SNBD. Patients with tumors located in the upper third of the stomach were more likely candidates for local resection than those with tumors in other locations (upper third, 68%; middle third, 50%; and lower third, 51%), whereas patients with tumors located in the anterior wall were less likely candidates than those with tumors other locations (anterior wall, 31%; posterior wall, 58%; greater curvature, 55%; and lesser curvature, 57%). CONCLUSION: We found that > 50% of the patients indicated for SN navigation surgery, particularly those with tumors in the upper third of the stomach, potentially could undergo partial resection with SNBD.

BACKGROUND: Robotic gastrectomy (RG) for gastric cancer (GC) has been increasingly performed for a decade; however, evidence for its use as a standard treatment has not yet been established. The present study aimed to determine the safety, feasibility, and effectiveness of RG for GC. METHODS: This multi-institutional, single-arm prospective study, which included 330 patients from 15 institutions, was designed to compare morbidity rate of RG with that of a historical control (conventional laparoscopic gastrectomy, LG). This trial was approved for Advanced Medical Technology ("Senshiniryo") B. The included patients were operable patients with cStage I/II GC. The primary endpoint was morbidity (Clavien-Dindo Grade ≥ IIIa). The specific hypothesis was that RG could reduce the morbidity rate to less than half of that with LG (6.4%). A sample size of 330 was considered sufficient (one-sided alpha 0.05, power 80%). RESULTS: Among the 330 study patients, the protocol treatment was suspended in 4 patients. Thus, 326 patients fully enrolled and completed the study. The median patient age and BMI were 66 years and 22.4 kg/m2, respectively. Distal gastrectomy was performed in 253 (77.6%) patients. The median operative time and estimated blood loss were 313 min and 20 mL, respectively. No 30-day mortality was seen, and morbidity showed a significant reduction to 2.45% with RG (p = 0.0018). CONCLUSIONS: RG for cStage I/II GC is safe and feasible. It may be effective in reducing morbidity with LG.

BACKGROUND: Although esophagectomy is the only curative option for esophageal cancer, the associated invasiveness is high. Nasogastric (NG) tube use may prevent complications; however, its utility remains unclear, and the decompression period depends on the doctor. This study aimed to reveal the effect of conventional versus early NG tube removal on postoperative complications after esophagectomy. METHODS: This single-center prospective randomized controlled clinical trial enrolled patients aged 20-80 years with histologically proven primary esophageal squamous cell carcinoma. Eighty patients admitted for transthoracic first-stage esophagectomy reconstructed with gastric conduit were randomly assigned (1:1) to the conventional and early NG tube removal groups. In the conventional NG tube removal group, the tube was removed on postoperative day (POD) 7; in the other, it was removed on POD 1. The occurrence rate of major complications, length of postoperative hospital stay, and NG tube reinsertion rate were compared between the groups. RESULTS: The incidence of postoperative major complications such as pneumonia, anastomotic leakage, recurrent nerve palsy and gastrointestinal bleeding, and the NG tube reinsertion rate was not different between the groups. However, recurrent nerve palsy was more commonly observed in the conventional removal group; this difference was not significant. In terms of postoperative pneumonia, tumor location and field of lymph node dissection were significant risk factors. CONCLUSION: Although early NG tube removal did not reduce the rate of postoperative pneumonia, it could be performed safely. Hence, the NG tube can be removed earlier than conventional methods.

OBJECTIVES: Current evidence regarding metabolic surgery suggests that different types of digestive tract reconstruction can result in differences in postoperative glucose tolerance. This study evaluated the impact of Billroth I (B-I), Billroth II (B-II), and Roux-en-Y (R-Y) procedures on peri-operative glucose tolerance in patients with gastric carcinoma who had diabetes mellitus. METHODS: A single-institution, retrospective cohort study was conducted using data from patients who underwent totally laparoscopic distal gastrectomy. These patients were grouped according to the type of reconstruction (B-I, B-II, or R-Y). After the operation, we addressed the changes in glucose tolerance-including changes in HbA1c levels, remission of diabetes, and overall effects of the treatment. RESULTS: We studied 57 patients (B-I, n=32; B-II, n=17; R-Y, n=8). B-II and R-Y reconstruction improved HbA1c levels more than B-I. Notably, R-Y improved tolerance the most (B-I vs. B-II, p<0.001; B-I vs. R-Y, p<0.001; B-II vs. R-Y, p<0.001). The type of reconstruction (B-II and R-Y vs. B-I) and a pre-operative HbA1c ≥7% were the two significant independent contributing factors determining postoperative improvement in HbA1c, with odds ratio (OR) 8.437, 95% confidence interval (CI) 1.635-43.527, p=0.011; OR 16.5, 95% CI 3.361-81.011, p=0.001, respectively. CONCLUSIONS: Either R-Y or B-II should be considered the primary option for patients with gastric carcinoma and diabetes when glycemic control is insufficient.

OBJECTIVES: Anastomotic leak is a common complication after esophagectomy for esophageal cancer. This study evaluated the impact of the Kocher maneuver on the incidence of anastomotic leak following esophagogastrostomy using a 3-cm-wide gastric conduit. METHODS: This single-institution, retrospective, cohort study included 43 patients who underwent thoraco-laparoscopic esophagectomy. The Kocher maneuver was not performed in the first half of the study period between April 2014 and May 2015 (first half group, n=14), but was performed in the second half between May 2015 and January 2017 (second half group, n=29). Primary endpoint was the incidence of anastomotic leak. Metrological values of the gastric conduit were postoperatively assessed on computed tomography. Blood perfusion of the gastric conduit was prospectively examined using the indocyanine green fluorescence method. RESULTS: The incidence of anastomotic leak was 14%; the incidence was significantly lower in the second half group than in the first half group (3.4% vs. 35.7%, p=0.01). The Kocher maneuver was the only significant independent risk factor associated with anastomotic leak (OR 0.064, 95% CI 0.007-0.625, p=0.018). The postoperative length of the entire gastric conduit was significantly shorter in the second half group than in the first half group. A more anal location of the 3-cm-wide gastric conduit was associated with better blood perfusion. CONCLUSIONS: The Kocher maneuver may enable shortening of the gastric conduit, leading to better blood perfusion of the tip of the gastric conduit, and a significant reduction in the occurrence of anastomotic leak.

BACKGROUND: Sentinel node (SN) concept is being applied to early gastric cancer. However, when SNs are positive for metastasis, it is unclear how often LNs in other LN basins show metastasis. We aimed to investigate LN metastasis possibility in LN basins without SNs (non-SN basins). We determined risk factors for metastasis in non-SN basins and identified a prediction model for non-SN basin metastasis using classification and regression tree (CART) analysis. METHODS: We enrolled 550 patients who were diagnosed with cT1N0M0 or cT2N0M0 gastric cancer with a single lesion and underwent SN mapping. We adopted a dual-tracer method using a radioactive colloid and blue dye to detect SNs. RESULTS: Of all, 45 (8.2%) patients had SN metastasis; we divided them into two groups: LN metastasis positive and LN metastasis negative in non-SN basins. Univariate analysis showed that the groups differed significantly regarding lymphatic invasion (p = 0.007), number of identified SNs (p = 0.032), and macrometastasis in SN basins (p = 0.005). The CART decision tree for predicting LN metastasis in non-SN basins had area under the curve value of 0.86. Moreover, there were significantly differences in cancer-specific survival (CSS) between the two groups (p = 0.028). CONCLUSIONS: Macrometastasis in SN basins, lymphatic invasion, and number of identified SNs ≥ 5 are risk factors for LN metastasis in non-SN basins among gastric cancer patients. We identified a prediction model with CART analysis; patients with macrometastasis in SN basins and lymphatic invasion were considered to be at the highest risk for LN metastasis.

BACKGROUND: Radical esophagectomy for esophageal cancer is associated with high morbidity, especially with pulmonary complications. Mediastinoscopic esophagectomy via a small left neck incision combined with the esophageal hiatus, without using transthoracic approach, has been reported to reduce pulmonary complication; however, from technical point of view, this approach using non-articulating, straight, long forceps is extremely challenging, especially in the middle mediastinal area. Its technical difficulties may be attenuated using da Vinci Surgical System. The aim of this study was to evaluate the feasibility and safety of robot-assisted mediastinoscopic esophagectomy. METHODS: Robot-assisted mediastinoscopic esophagectomy was performed in six patients between October 2016 and May 2017. Robotic esophageal mobilization with upper and middle mediastinal lymphadenectomy was performed via the three da Vinci Xi (Intuitive Surgical, Inc. Sunnyvale, CA) trocars placed on the 5-cm left cervical incision. Thereafter, the remaining part of radical esophagectomy was completed via a transhiatal approach. RESULTS: Upper and middle mediastinal lymphadenectomy was robotically completed via the transcervical approach in all cases without conversion to transthoracic approach. No postoperative complications (Clavien-Dindo classification grade ≥ III) were observed. CONCLUSIONS: Robot-assisted mediastinoscopic esophagectomy was technically feasible and safe. Use of da Vinci Surgical System may help attenuate technical difficulties in transcervical middle mediastinal lymph node dissection.

当施設では早期胃癌に対するセンチネルリンパ節(SN)理論を用いた個別化縮小手術の確立に向けて研究を行っている。胃癌におけるSN理論によると、SN転移陰性であれば他のリンパ節への転移はないと考えることができるが、SN転移陽性例において、SNを含まないbasin(Non-SN basin)への転移がどの程度あるかは知られていない。今回、SN転移陽性であっても症例によってはSN basinの切除のみを行う縮小手術が可能であるという仮説を立て、SN転移を有する患者を対象に、Non-SN basin転移の危険因子について検討した。結果、有意な危険因子として「リンパ管浸潤」「SN同定個数5個以上」「SN basin内のマクロ転移」が抽出された。

BACKGROUND OR PURPOSE: As we previously indicated, postoperative pneumonia has a negative impact on the overall survival after planned esophagectomy. However, the impact of postoperative pneumonia after salvage esophagectomy on long-term oncologic outcomes still remains unclear. This study aimed to indicate the association between postoperative pneumonia and long-term outcomes of definitive chemoradiotherapy followed by salvage esophagectomy. Furthermore, we determined a prediction model for overall survival (OS) and disease-free survival (DFS) using a survival classification and regression tree (CART). METHODS: Ninety-three patients who underwent CRT followed by esophagectomy for thoracic esophageal cancer were identified for this study. Forty-nine patients and 44 patients were included in the salvage and neoadjuvant groups, respectively. We investigated the association between postoperative pneumonia and long-term oncologic outcomes following salvage esophagectomy. RESULTS: Patients from the salvage group tended to have a lower OS compared to neoadjuvant group (median survival: salvage, 24 months vs neoadjuvant, 43 months, p = 0.117). Multivariate analyses revealed that postoperative pneumonia adversely affected both OS (p < 0.001) and DFS (p = 0.044) after salvage esophagectomy. We generated the prediction model for OS and DFS in the salvage group using survival CART. Postoperative pneumonia was the most important parameter for predicting the OS. DISCUSSION: The present study demonstrates the long-term outcomes and risk factors for mortality of salvage esophagectomy. To improve OS after salvage surgery, the development of a means of decreasing pulmonary complications is needed.

Aim: The aim of the present study was to clarify esophagogastric junction (EGJ) carcinoma patients who are at high risk of upper and middle mediastinal lymph node (MLN) metastasis. Methods: This was a retrospective study and included 110 consecutive patients with EGJ carcinoma who underwent R0/R1 resection at Keio University Hospital between January 2000 and December 2013. Results: Of the 110 patients, 18 (16.3%) had MLN metastasis, and the number increased to 23 (20.9%) when recurrence cases were added (adenocarcinoma, N = 11; squamous cell carcinoma, N = 12). Patients whose tumor epicenter was located above the EGJ had a significantly higher incidence of MLN metastasis/recurrence (18/51 [35.3%]) than those whose tumor epicenter was located below the EGJ (5/59 [8.5%]). The MLN metastasis/recurrence rate was particularly high when the distance from the EGJ to the proximal edge of the primary tumor was >3 cm for the upper and middle mediastinum (18.8%). Patients in a selected group (≥T2 and tumor epicenter located above the EGJ or below the EGJ with ≥3 cm esophageal invasion) showed 17.9% and 15.4% upper and middle MLN metastasis/recurrence rates, respectively. Therapeutic value of MLN dissection was relatively high (#105 + 106: 8.9, #110: 12.2). Conclusions: Therapeutic value of MLN dissection to treat EGJ carcinomas was relatively high in patients with MLN metastasis. Our algorithm could select patients at high risk for MLN metastasis.

＜文献概要＞point ・頸部アプローチ視野における気管・食道・血管・神経の解剖学的位置の把握・気縦隔の利点と単孔式デバイスの特徴を考慮した剥離操作

BACKGROUND: Little is known about hyponatremia in patients with esophageal cancer treated with cisplatin-based chemotherapy. The aim of this study was to analyze the risk factors for hyponatremia and its effect on outcomes in patients with esophageal cancer treated with chemotherapy including cisplatin. METHODS: We retrospectively analyzed the records of 137 patients with esophageal cancer who received chemotherapy including cisplatin for the first time between January 2011 and December 2014. RESULTS: Hyponatremia (Na < 135 mEq/L) was seen in 77 patients (59%), of whom 29 had Grade 3 (120 ≤ Na < 130 mEq/L) or Grade 4 (Na < 120 mEq/L) hyponatremia. We divided patients into the hyponatremia group (patients with Na < 130 mEq/L) and the control group (patients with Na ≥ 130 mEq/L), and compared the results between the two groups. Three patients (2%) were diagnosed with the syndrome of inappropriate secretion of antidiuretic hormone. The serum sodium level before starting chemotherapy was significantly lower and white blood cell count was significantly higher in the hyponatremia group. Appetite loss was seen significantly more often in the hyponatremia group as the chemotherapy-related adverse effect. There was no significant difference in overall survival between the two groups. CONCLUSIONS: Hyponatremia is a common adverse effect induced by cisplatin. Caution should be exercised with patients with a low sodium level before starting chemotherapy. Hyponatremia can be associated with other chemotherapy-related adverse effects, and it should therefore be treated correctly.

Background: Oesophagectomy has a high risk of postoperative morbidity. The impact of postoperative complications on overall survival of oesophageal cancer remains unclear. This meta-analysis addressed the impact of complications on long-term survival following oesophagectomy. Methods: A search of PubMed and Cochrane Library databases was undertaken for systematic review of papers published between January 1995 and August 2016 that analysed the relation between postoperative complications and long-term survival. In the meta-analysis, data were pooled. The main outcome was overall survival (OS). Secondary endpoints included disease-free (DFS) and cancer-specific (CSS) survival. Results: A total of 357 citations was reviewed; 21 studies comprising 11 368 patients were included in the analyses. Overall, postoperative complications were associated with significantly decreased 5-year OS (hazard ratio (HR) 1·16, 95 per cent c.i. 1·06 to 1·26; P = 0·001) and 5-year CSS (HR 1·27, 1·09 to 1·47; P = 0·002). Pulmonary complications were associated with decreased 5-year OS (HR 1·37, 1·16 to 1·62; P < 0·001), CSS (HR 1·60, 1·35 to 1·89; P < 0·001) and 5-year DFS (HR 1·16, 1·00 to 1·33; P = 0·05). Patients with anastomotic leakage had significantly decreased 5-year OS (HR 1·20, 1·10 to 1·30; P < 0·001), 5-year CSS (HR 1·81, 1·11 to 2·95; P = 0·02) and 5-year DFS (HR 1·13, 1·02 to 1·25; P = 0·01). Conclusion: Postoperative complications after oesophagectomy, including pulmonary complications and anastomotic leakage, decreased long-term survival.

BACKGROUND AND AIMS: Active use of endoscopic resection (ER) for cM3-SM2 esophageal cancer may enable sufficient extent of esophageal resection and help determine the need for lymph node dissection based on histopathologic findings. However, ER preceding esophagectomy may have an adverse impact on outcomes. This study was designed to determine the technical feasibility and oncologic safety of diagnostic ER. METHODS: A single-institution retrospective cohort study was performed between July 2008 and June 2014. During this period, 135 consecutive patients with clinical T1a-M3N0M0, T1b-SM1N0M0, and T1b-SM2N0M0 primary esophageal cancer were referred to our division. Eight patients who underwent chemoradiotherapy as primary treatment were excluded because of inadequate pathologic findings. Based on oncologic and physical factors, we categorized the remaining 127 patients into 2 groups: primary esophagectomy (n = 54) and primary ER (n = 73). RESULTS: In all 127 patients, the 3-year overall survival (OS) and disease-free survival (DFS) rates were 95.7% and 87.6%, respectively. No adverse event requiring surgical intervention was observed after ER. Diagnostic ER had no negative impact on surgical outcomes, DFS, and OS after esophagectomy. Fourteen patients (19.2%) of those who received primary ER underwent curative resection, whereas 11 (20.4%) who had pT1a disease, no lymphovascular invasion, and no pathologic lymph node metastasis underwent primary esophagectomy. CONCLUSIONS: Diagnostic ER for cM3-SM2 esophageal cancer with or without subsequent esophagectomy was feasible and safe, not only from a surgical perspective but also an oncologic perspective. Approximately 20% of cM3-SM2N0M0 patients can potentially avoid undergoing additional treatment including esophagectomy using diagnostic ER.

BACKGROUND: Inflammatory myofibroblastic tumor is an uncommon soft tissue neoplasm rarely reported in the stomach. CASE PRESENTATION: We identified a tumor highly suggestive of poorly differentiated gastric adenocarcinoma in the lesser curvature of the stomach of a 53-year-old female during screening endoscopy. Although the patient's gastric biopsy did not reveal cancer, the tumor configuration was strongly suspicious for malignancy, and we performed a gastric wedge resection using a combined laparoscopic and endoscopic method. The lesion was diagnosed as inflammatory myofibroblastic tumor based on its morphological and immunohistological features. CONCLUSIONS: Inflammatory myofibroblastic tumor should be considered in the differential diagnosis of soft tissue tumors in the stomach. We present a case of inflammatory myofibroblastic tumor safely treated with combined laparoscopic and endoscopic gastric wedge resection.

＜文献概要＞切除可能進行食道癌に対しては手術を治療の軸として,本邦では5-FU+cisplatin併用術前化学療法が標準治療として位置づけられている.現在,術前化学療法・化学放射線療法を比較する3アームの第III相試験(JCOG1409)が進行中である.一方,切除不能局所進行食道癌に対しては根治的化学放射線療法が選択される.さらなる治療成績の向上をめざして5-FU+cisplatin+docetaxelによる導入化学療法の有効性を検証する第III相試験(JCOG1510)が開始された.

PURPOSE: This study aimed to evaluate the feasibility and safety of intracorporeal anastomosis with Billroth I, Billroth II, or Roux-en-Y reconstructions in totally laparoscopic distal gastrectomy. MATERIALS AND METHODS: A single-institution, retrospective, cohort study including 553 patients was conducted. Intracorporeal isosceles right triangle-shaped anastomosis without slack and torsion was created using linear staplers. Billroth I was primarily used. Surgical outcomes and perioperative nutritional status were assessed. RESULTS: Morbidity was 11.5%. Postoperative early complications related to anastomosis occurred in 13 patients (2.4%). Operative time and reconstruction type (Billroth I vs. others) were the only significant independent risk factors determining postoperative early and late complications, respectively. No difference was observed in postoperative changes in nutritional status across the groups, although Billroth II increased reflux esophagitis requiring medication. CONCLUSIONS: Intracorporeal isosceles right triangle-shaped anastomosis using linear staplers in totally laparoscopic distal gastrectomy, in combination with our selection algorithm for type of reconstruction, is feasible and safe.

＜文献概要＞内視鏡的切除適応外の早期胃癌の外科治療として腹腔鏡下胃切除術が急速に普及しつつある.腹腔鏡下手術は開腹手術と比べて創縮小,術後疼痛軽減,出血軽減,早期回復など複数の利点を有する一方,技術的困難性,手術時間延長,長期予後に関するエビデンスの不足などの欠点も指摘されている.cStageI遠位側胃癌を対象とした多施設共同前向き非対照第II相試験(JCOG0703)で熟練者による腹腔鏡下幽門側胃切除術,D1+郭清の安全性が示され,「胃癌治療ガイドライン第4版」で日常診療の選択肢の一つとされた.また,低侵襲性向上,機能温存の試みとして,ロボット支援手術や腹腔鏡下センチネルリンパ節生検が行われ,先進医療Bとしてその臨床的有用性が検証されている.

BACKGROUND: Based on our experience of suprapancreatic nodal dissection in laparoscopic gastrectomy, we developed an outermost layer-oriented medial approach for infrapyloric nodal dissection. The objective of this single-institution retrospective study was to determine the feasibility, safety, and reproducibility of this novel and unique dissection procedure. METHODS: This approach can be performed in the same manner as suprapancreatic nodal dissection but by replacing the left gastric artery with the right gastroepiploic artery (RGEA), the common hepatic artery with the anterior superior pancreaticoduodenal artery (ASPDA), and the splenic artery with the gastroduodenal artery. It comprises five steps: (1) mobilization of the transverse mesocolon along the prepancreatic membrane, (2) medial dissection along the dissectable layer between the pancreatic head and the dorsal side of the right gastroepiploic vein (RGEV), (3) division of the RGEV and determination of the lateral and cranial borders, (4) dissection along the outermost layer of the RGEA and ASPDA and transection of the infrapyloric artery and RGEA, and (5) transection of the duodenal bulb. RESULTS: This novel method was applied in 112 patients who underwent laparoscopic distal gastrectomy from 2014 to 2015. The anatomical landmarks that we determined to appropriately identify the outermost layer were highly reproducible, and our novel procedure based on these landmarks was successfully completed in all cases, without any intraoperative complications. Furthermore, in all cases, no. 6 lymph nodes were fully and adequately dissected within the infrapyloric area anatomically defined in the Japanese Classification of Gastric Carcinoma ver. 14. Pancreatic fistula occurred only in 1.8% cases. CONCLUSIONS: This novel outermost layer-oriented medial approach is a robust procedure that may help laparoscopic surgeons in performing safe and reproducible infrapyloric nodal dissection.

BACKGROUND: Few risk models have been provided to predict long-term prognosis after esophagectomy. This study investigated the reliability of a risk calculator as well as classification and regression trees analysis for predicting long-term prognosis after esophagectomy for esophageal cancer. METHODS: The study enrolled 438 patients who underwent esophagectomy at Keio University Hospital, Tokyo, Japan, between July 2000 and June 2016. Patients who underwent R0 or R1 resection or esophagectomy with combined resection of other organs were included. The authors investigated the usefulness of a risk model for 30-day mortality and operative mortality described in their previous report for predicting long-term prognosis after esophagectomy. RESULTS: The 438 patients (377 men and 61 women) in this study had a 5-year overall survival (OS) rate of 62.8% and a disease-free survival rate of 54.3%. The OS was higher for the patients with 30-day mortality risk model values lower than 0.675% than for those with values higher than 0.675% (p < 0.001). The cutoff values for prediction were shown to be significant risk factors in the multivariate analysis. The risk calculator was validated by comparing the cutoff values with Harrell's C-index values of clinical stage. For overall risk, the C-index of operative mortality was 0.697, and the C-index of cStage was 0.671. CONCLUSIONS: The risk calculator was useful for predicting recurrence and death after esophagectomy. Furthermore, because the C-index of the risk model for operative mortality was higher than for clinical tumor-node-metastasis stage, this risk-scoring system may be more useful clinically.