皮下埋没縫合および皮下閉鎖式陰圧ドレーン挿入による、回腸人工肛門閉鎖術後創部感染の減少効果について

Purpose: The purpose of this study was to evaluate the effectiveness of a wound closure method using a combination of subcuticular sutures and subcutaneous closed-suction drainage (SS closure) for preventing incisional surgical site infection (SSI) in loop ileostomy closure. Methods: A total of 178 consecutive patients who underwent loop ileostomy closure at Nara Medical University Hospital between 2004 and 2018 were retrospectively assessed. The patients were divided into 2 groups: the conventional skin closure (CC) group from 2004 to 2009 (75 patients) and the SS closure (SS) group from 2010 to 2018 (103 patients). The incidence of incisional SSI was compared between the two groups, and the factors associated with incisional SSI were examined by univariate and multivariate analyses. Results: Incisional SSI occurred in 7 cases (9.3%) in the CC group but was significantly reduced to only 1 case (0.9%) in the SS group (p = 0.034). In the univariate analysis, the hemoglobin levels, serum creatinine levels, and SS closure were associated with incisional SSI. SS closure was the only independent preventive factor for incisional SSI according to the multivariate analysis (hazard ratio = 0.24, p = 0.011). Conclusion: The combination of subcuticular sutures and subcutaneous closed-suction drainage may be a promising way of preventing incisional SSI in loop ileostomy closure.博士（医学）・乙第1496号・令和3年3月15日© Springer Nature Singapore Pte Ltd. 2020This is a post-peer-review, pre-copyedit version of an article published in Surgery today. The final authenticated version is available online at: https://doi.org/10.1007/s00595-020-02128-x

無症候性腎機能障害が結腸癌術後の臨床経過に及ぼす影響

Purpose: To evaluate the effect of mild renal dysfunction on the clinical course after colectomy in patients with colon cancer. Methods: The subjects of this retrospective study were 263 patients who underwent surgical resection for colon cancer at our hospital between 2011 and 2015. Renal function was assessed based on preoperative estimated glomerular filtration rate (eGFR) values. Patients were divided into groups based on their eGFR value of 55 ml/min/1.73 m2. The Mann-Whitney U test, chi-square or Fisher exact test, and log-rank test were used in the data analysis. Results: There were 59 patients (22.4%) in the low eGFR group and 204 patients in the normal eGFR group. There were differences between the groups in age, comorbidities, and the levels of hemoglobin, albumin, and serum creatinine. The overall postoperative complication rate, frequency of severe complications, and length of stay were significantly higher in the low eGFR group than in the normal eGFR group. Multivariate analysis revealed that low eGFR was the only independent risk factor for severe complications (Clavien-Dindo classification III/IV). There were no differences in survival between the groups. Conclusion: Preoperative asymptomatic renal dysfunction may be correlated with the development of postoperative complications and a possible significant risk factor for severe complications after colon cancer surgery.博士（医学）・甲第804号・令和3年12月21日© 2021. Springer Nature Singapore Pte Ltd.The version of record of this article, first published in Surgery Today, is available online at Publisher’s website: http://dx.doi.org/10.1007/s00595-021-02363-w.発行元が定める登録猶予期間終了の後、本文を登録予定（2021.01

下部直腸癌における側方リンパ節転移に関して、造影MRI で描出される中直腸動脈の転移予測因子に関する検討

Purpose: Lateral lymph node (LLN) metastasis is one of the leading causes of local recurrence in patients with lower rectal cancer. Unfortunately, no diagnostic biomarkers are currently available that can predict LLN metastasis preoperatively. Accordingly, we investigated the relationship between the middle rectal artery (MRA) identified by contrast-enhanced magnetic resonance imaging (ceMRI) and LLN metastases. Methods: Data from 102 patients with lower rectal cancer who underwent surgery, and were evaluated by preoperative ceMRI, between 2008 and 2016 were reviewed retrospectively. Two expert radiologists evaluated the MRA findings. The diagnostic performance of MRA for LLN metastasis was evaluated by a multivariate analysis with conventional clinicopathological factors. Results: The MRA was detected in 67 patients (65.7%), including 32 (31.4%) with bilateral MRA and 35 (34.3%) with unilateral MRA. The tumor size, presence of the MRA, and clinical LLN status were significantly correlated with LLN metastasis. A multivariate analysis demonstrated that the presence of MRA (P = 0.045) and clinical LLN status (P = 0.001) were independent predictive factors for LLN metastasis. Furthermore, the sensitivity and negative predictive value of MRA for LLN metastasis were 95% and 97.1%, respectively. Conclusion: We successfully demonstrated that MRAs could be clearly detected by ceMRI, and the presence of MRA robustly predicted LLN metastasis in patients with lower rectal cancer, highlighting its clinical significance in the selection of more appropriate treatment strategies. Trial registration: Trial registration number: retrospectively registered 2126 Trial registration date of registration: August 23, 2019.博士（医学）・乙第1512号・令和3年12月21日© 2021. The Author(s). Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/

根治切除後の結腸癌StageⅡ、StageⅢ、及び大腸癌肝転移における原発部位が与える影響

Purpose: Primary tumor location of colon cancer has been reported to affect the prognosis after curative resection. However, some reports suggested the impact was varied by tumor stage. This study analyzed the prognostic impact of the sidedness of colon cancer in stages II, III, and liver metastasis after curative resection using propensity-matched analysis. Methods: Right-sided colon cancer was defined as a tumor located from cecum to splenic flexure, while any more distal colon cancer was defined as left-sided colon cancer. Patients who underwent curative resection at Nara Medical University hospital between 2000 and 2016 were analyzed. Results: There were 110 patients with stage II, 100 patients with stage III, and 106 patients with liver metastasis. After propensity matching, 28 pairs with stage II and 32 pairs with stage III were identified. In the patients with stage II, overall survival (OS) and recurrence-free survival (RFS) were not significantly different for right- and left-sided colon cancers. In the patients with stage III, OS and RFS were significantly worse in right-sided colon cancer. In those with liver metastasis, OS of right-sided colon cancer was significantly worse than left-sided disease, while RFS was similar. Regarding metachronous liver metastasis, the difference was observed only in the patients whose primary colon cancer was stage III. In each stage, significantly higher rate of peritoneal recurrence was found in those with right-sided colon cancer. Conclusion: Sidedness of colon cancer had a significant and varied prognostic impact in patients with stage II, III, and liver metastasis after curative resection.博士（医学）・乙第1495号・令和3年3月15日Copyright © 2021 The Korean Society of Coloproctology.This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited

Fabrication of a Visualization Equipment for Scattered X-rays in the Diagnosis Domain and Proposal of a Practical Training

We have built equipment that can visualize the angle distributions of scattered X-rays. The main body of the equipment is made of a lead-shielded box 340 mm long, 300 mm wide and 270 mm high. The collimated X-rays are introduced into the equipment from the front face, then scattered by the sample located in the center of the equipment. The X-rays scattering toward the upper side are detected by the phosphor plate. To verify the usability of the equipment, an experiment using diagnostic X-rays was carried out. X-rays with a tube voltage of 100 kV were narrowed down to 6 mmφ and a 2 mm-thick acrylic sample was irradiated. The experimental conditions with a tube current-time product of 300 mAs to 1500 mAs proved appropriate for obtaining suitable images on a 10 inch×12 inch phosphor plate. The obtained images were analyzed using ImageJ. The experimental values were in good agreement with the theoretical distribution calculated by Klein and Nishina. Because the distribution of the scattered X-rays can be visualized in relatively simple experiments using the developed equipment, it is hoped that it will be of use for the practical training of beginners

結腸直腸内視鏡的粘膜下層剥離術後腸管内洗浄液中遊離腫瘍細胞に対する in vitro 解析

Purpose: Colorectal endoscopic submucosal dissection (ESD) produces exfoliated tumor cells that occasionally cause local recurrence. However, the biological characteristics of these tumor cells have not been clarified. The aim of this study was to clarify the genetic background and viability of exfoliated tumor cells in colorectal ESDs, as well as possible method for their elimination. Methods: Post-ESD intraluminal lavage samples from 19 patients who underwent colorectal ESDs were collected. In four patients with adenocarcinoma, gene mutations in the primary tumors and exfoliated cells in lavage samples were analyzed using a next-generation sequencer (NGS). In 15 patients with adenoma or adenocarcinoma, the viability of exfoliated cells and the cell-killing effect of povidone-iodine on exfoliated cells were evaluated. Results: The analysis using a NGS demonstrated that tumors targeted for ESD had already acquired mutations in many genes involved in cell proliferation, angiogenesis, and invasions. Furthermore, gene mutations between the exfoliated tumor cells and tumors resected by ESDs showed a 92 to 100% concordance. The median viable cell counts and the median viability of exfoliated cells in intraluminal lavage samples after ESDs were 4.9 × 105 cells/mL and 24%, respectively. The viability of the exfoliated cells did not decrease even 12 h after ESD. However, contact with 2.0% povidone-iodine solution reduced both viable cell counts and viability, significantly. Conclusion: A large number of tumor cells exfoliated during colorectal ESDs had acquired survival-favorable gene mutations and could survive for some time. Therefore, a lavage using a solution of 2.0% povidone-iodine may be effective against such cells. Trial registration: The prospective study registered 1317, and the retrospective study registered 2729. The prospective study approved on June 20, 2016, and the retrospective study approved on October 6, 2020.博士（医学）・乙第1520号・令和4年3月15日© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00384-021-04037-y.発行元が定める登録猶予期間終了の後、本文を登録予定（2023.01