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Rectal gastrointestinal stromal tumors (GISTs) surgery is often challenging owing to the anatomical constraints of the narrow pelvis and tumor hugeness. Despite the increasing number of patients undergoing trans-anal total mesorectal excision (taTME) globally, the feasibility of trans-anal surgery with the taTME technique for rectal GISTs remains unclear. We aimed to evaluate the feasibility of trans-anal surgery with the taTME technique for rectal GISTs.Using a prospectively collected database, we retrospectively analyzed the clinical findings, surgical outcomes, pathological outcomes, urinary and anal functions, and prognoses of patients who underwent trans-anal surgery with the taTME technique for primary rectal GISTs at the National Cancer Center Hospital East from September 2014 to March 2020.Twenty-one patients with primary rectal GISTs were included in this study. The median distance from the anal verge to the lower edge of the tumor was 40 mm (range, 15-60 mm), and the median tumor size was 59 mm (range, 11-175 mm). Moreover, seven and 14 patients underwent one-team and two-team surgeries, respectively, with curative intent. Nineteen patients (90.5%) underwent anus-preserving surgery, and the urinary tracts were preserved in all cases. Two-team surgery showed a significantly lower blood loss volume and shorter operation time than one-team surgery (58 vs. 222 mL, P = 0.017; 184 vs 356 min, P = 0.041, respectively). The pathological negative-margin resection rate was 100%. During the follow-up period, no patient developed local GIST recurrence and one (4.8%) developed distant metastasis.Trans-anal surgery with the taTME technique is feasible for rectal GISTs, and two-team surgery may be more advantageous than one-team surgery in terms of operation time and blood loss.

The Japanese operative-rating scale for laparoscopic distal gastrectomy (JORS-LDG) was developed through cognitive task analysis together with the Delphi method to measure intraoperative performance during laparoscopic distal gastrectomy. This study aimed to investigate the value of this rating scale as an educational tool and a surgical outcome predictor in laparoscopic distal gastrectomy.The surgical performance of laparoscopic distal gastrectomy was assessed by the first assistant, through self-evaluation in the operating room and by video raters blind to the case. We evaluated inter-rater reliability, internal consistency, and correlations between the JORS-LDG scores and the evaluation methods, patient characteristics, and surgical outcomes.Fifty-four laparoscopic distal gastrectomy procedures performed by 40 surgeons at 16 institutions were evaluated in the operating room and with video recordings using the proposed rating scale. The video inter-rater reliability was 0.8. Participating surgeons were divided into the low, intermediate, and high groups based on their total scores. The number of laparoscopic surgeries and laparoscopic gastrectomy procedures performed differed significantly among the groups according to laparoscopic distal gastrectomy skill levels. The low, intermediate, and high groups also differed in terms of median operating times (311, 266, and 229 min, respectively, P 0.001), intraoperative complication rates (27.8, 11.8, and 0%, respectively, P = 0.01), and postoperative complication rates (22.2, 0, and 0%, respectively, P = 0.002).The JORS-LDG is a reliable and valid measure for laparoscopic distal gastrectomy training and could be useful in predicting surgical outcomes.

BackgroundPurse-string suture in transanal total mesorectal excision is a key procedural step. The aims of this study were to develop an automatic skill assessment system for purse-string suture in transanal total mesorectal excision using deep learning and to evaluate the reliability of the score output from the proposed system.MethodsPurse-string suturing extracted from consecutive transanal total mesorectal excision videos was manually scored using a performance rubric scale and computed into a deep learning model as training data. Deep learning-based image regression analysis was performed, and the purse-string suture skill scores predicted by the trained deep learning model (artificial intelligence score) were output as continuous variables. The outcomes of interest were the correlation, assessed using Spearman’s rank correlation coefficient, between the artificial intelligence score and the manual score, purse-string suture time, and surgeon’s experience.ResultsForty-five videos obtained from five surgeons were evaluated. The mean(s.d.) total manual score was 9.2(2.7) points, the mean(s.d.) total artificial intelligence score was 10.2(3.9) points, and the mean(s.d.) absolute error between the artificial intelligence and manual scores was 0.42(0.39). Further, the artificial intelligence score significantly correlated with the purse-string suture time (correlation coefficient = −0.728) and surgeon’s experience (P< 0.001).ConclusionAn automatic purse-string suture skill assessment system using deep learning-based video analysis was shown to be feasible, and the results indicated that the artificial intelligence score was reliable. This application could be expanded to other endoscopic surgeries and procedures.

In abdominoperineal excision (APE), the advantages of the "down-to-up" approach are expected to be more obvious when performed as a two-team approach, including transperineal minimally invasive surgery (TpMIS). We investigated the efficacy of TpMIS with laparoscopic APE for lower rectal cancer.Patients who underwent laparoscopic APE with (n = 20) or without (n = 30) TpMIS between December 2013 and April 2020 were retrospectively reviewed. Patient and tumor characteristics, intraoperative outcome, short-term outcome, and pathological findings were compared. Additional subgroup analyses were performed in technically challenging cases, including male patients, obese patients, and patients with tumors located at the anterior wall.There was no marked difference in the patient or tumor characteristics or short-term outcomes, including morbidity and mortality between the two groups. Pathological results were comparable, and the circumferential resection margin (CRM) positive rate was 10% in both groups. TpMIS achieved a significant reduction in operative time (p = 0.02). In a subgroup analysis, the amount of blood loss was also smaller in males (p = 0.02) and patients with a high BMI ( 25) (p = 0.005) than in others.Simultaneously performing TpMIS and laparoscopic APE is feasible owing to the favorable complication and CRM-positive rates. In terms of operative time and blood loss, TpMIS is expected to be advantageous in both easy and challenging cases.

Mucosal prolapse at the site of anastomosis is a long-term complication unique to ISR. It reduces the QOL of patients due to a worsened anal function and local symptoms around the anus. We herein sought to assess the surgical outcomes after Delorme surgery for these patients. ISR was performed in 720 patients with low rectal cancer between January 2001 and March 2019 at the National Cancer Center Hospital East. Among these patients, the 33 (4.5%) who underwent initial Delorme surgery for postoperative colonic mucosal prolapse were identified from the medical records and then were analyzed retrospectively. We estimated the anal function using Wexner’s incontinence score and assessed whether local anal symptoms due to the prolapse improved postoperatively. Stoma closure was performed before Delorme surgery in 15 (45.5%) patients, and we compared the preoperative and postoperative anal function in these patients. The average Wexner’s incontinence score changed from 15.1 before to 12.9 after Delorme surgery. Local symptoms around the anus improved in all 33 (100%) patients. Recurrence of colonic mucosal prolapse occurred in 5 patients (15%), and Delorme surgery was reperformed in these cases. Delorme surgery for colonic mucosal prolapse following ISR has clinical benefits for both improving anal local symptoms and slightly improving the anal function.

Urethral injuries (UIs) are significant complications pertaining to transanal total mesorectal excision (TaTME). It is important for surgeons to identify the prostate during TaTME to prevent UI occurrence; intraoperative image navigation could be considered useful in this regard. This study aims at developing a deep learning model for real-time automatic prostate segmentation based on intraoperative video during TaTME. The proposed model’s performance has been evaluated. This was a single-institution retrospective feasibility study. Semantic segmentation of the prostate area was performed using a convolutional neural network (CNN)-based approach. DeepLab v3 plus was utilized as the CNN model for the semantic segmentation task. The Dice coefficient (DC), which is calculated based on the overlapping area between the ground truth and predicted area, was utilized as an evaluation metric for the proposed model. Five hundred prostate images were randomly extracted from 17 TaTME videos, and the prostate area was manually annotated on each image. Fivefold cross-validation tests were performed, and as observed, the average DC value equaled 0.71 ± 0.04, the maximum value being 0.77. Additionally, the model operated at 11 fps, which provides acceptable real-time performance. To the best of the authors’ knowledge, this is the first effort toward realization of computer-assisted TaTME, and results obtained in this study suggest that the proposed deep learning model can be utilized for real-time automatic prostate segmentation. In future endeavors, the accuracy and performance of the proposed model will be improved to enable its use in practical applications, and its capability to reduce UI risks during TaTME will be verified.

This study aimed to investigate the potential of the size and aspect ratio of metastatic and non-metastatic lateral pelvic lymph nodes (LPLNs) as low-risk markers for locally advanced lower rectal cancer, without treatment by neoadjuvant chemoradiation therapy or LPLN dissection.This single-center, retrospective cohort study evaluated 310 consecutive patients diagnosed with lower rectal cancer (T: T3/T4, N: any, and M: M0) who underwent curative surgery without neoadjuvant therapies between 2010 and 2018. The harvested LPLNs were categorized into groups A (metastasis-positive lymph nodes), B (metastasis-negative lymph nodes in the area bearing metastasis-positive lymph nodes), C (metastasis-negative lymph nodes in a metastasis-negative area in metastasis-positive patients), and D (lymph nodes in non-metastatic patients). The main outcome measure was the relationship among lymph node size, aspect ratio, and metastasis in the LPLNs.Overall, 3962 LPLNs were harvested. The long and short axes and the aspect ratio were significantly longer and higher, respectively, in group A than in the other groups (Metastatic LPLNs in patients with lower rectal cancer are significantly larger and have a higher aspect ratio. Lymph nodes with aspect ratios of0.4 were metastasis negative.

Highlights • Laparoscopic perineal hernia repair using a soft and large synthetic mesh is useful. • Using a large mesh could cover the hernial orifice with a sufficient margin. • Cone-shaped implantation is easy by folding a large mesh in the pelvic cavity., Introduction Perineal hernia after abdominoperineal resection (APR) is a rare complication, and no standard surgical procedures are established. We describe a simple laparoscopic mesh implantation technique utilizing a large synthetic flat mesh. Presentation of Case We report a case of perineal hernia after APR. We performed laparoscopic repair using a soft and large synthetic mesh with simple technique. The essence of this technique is that mesh is inserted into the abdominal cavity without trimming and it forms in a conical shape to better adjust to the pelvic cavity. Discussion The perineal and laparoscopic approaches for perineal hernia repair have been performed most commonly in recent years, but the recurrence rate after repair remains high (24.1%). Using a large mesh could cover the hernial orifice with a sufficient margin, reducing a risk of recurrence caused by shrinkage and slippage of the mesh. Conclusion Our technique utilizing a large, lightweight, synthetic mesh can be practical and useful for perineal hernia repair after laparoscopic APR.

Background The surgical indications for patients with pancreatic head cancer (PHC) with clinical portal vein (PV) invasion (cPV) remain controversial. The present study aimed to determine the ability of computed tomography (CT) to diagnose pathological PV involvement (pPV) in PHC. Patients and Methods We evaluated the morphological features (length and circumference) and two sets of diagnostic criteria for cPV determined from preoperative CT findings of 112 consecutive patients who underwent pancreatoduodenectomy for PHC. This study is listed in the UMIN Clinical Trials Registry (UMIN-CTR; No: UMIN000016827). Results Five patients were excluded because enhanced CT data were missing. Morphological features have low diagnostic ability for pPV. We diagnosed 67 patients with cPV based on our diagnostic criteria and those of Klauss, and 42 of them had pPV. The negative predictive values of these diagnostic criteria for pPV were satisfactory (>95%) and the positive predictive value was relatively low (61.2%). Postoperative survival could be predicted based on the cPV type. Conclusion An accurate diagnosis of pPV based on morphological features determined by preoperative CT is difficult. However, preoperative CT appears useful for selecting patients with PHC who could be candidates for pancreaticoduodenectomy with or without PV resection. This article is protected by copyright. All rights reserved.

The surgical indications for patients with pancreatic head cancer (PHC) with clinical portal vein (PV) invasion (cPV) remain controversial. The present study aimed to determine the ability of computed tomography (CT) to diagnose pathological PV involvement (pPV) in PHC.We evaluated the morphological features (length and circumference) and two sets of diagnostic criteria for cPV determined from preoperative CT findings of 112 consecutive patients who underwent pancreatoduodenectomy for PHC. This study is listed in the UMIN Clinical Trials Registry (UMIN-CTR; No: UMIN000016827).Five patients were excluded because enhanced CT data were missing. Morphological features have low diagnostic ability for pPV. We diagnosed 67 patients with cPV based on our diagnostic criteria and those of Klauss, and 42 of them had pPV. The negative predictive values of these diagnostic criteria for pPV were satisfactory (95%) and the positive predictive value was relatively low (61.2%). Postoperative survival could be predicted based on the cPV type.An accurate diagnosis of pPV based on morphological features determined by preoperative CT is difficult. However, preoperative CT appears useful for selecting patients with PHC who could be candidates for pancreaticoduodenectomy with or without PV resection.

結腸癌の消化管内瘻形成は稀な病態である．当科で経験した3例について報告する．症例1は61歳の女性．S状結腸癌，結腸小腸瘻，肝転移の診断でS状結腸切除，小腸合併切除，肝部分切除術を施行した．開腹時に単発の腹膜播種を認めた．腫瘍は回腸と瘻孔を形成していた．術後3年9カ月で肝転移と腹膜播種再発を認めた．症例2は78歳の女性．S状結腸癌の診断で手術施行．腫瘍は空腸に浸潤しておりS状結腸切除，空腸合併切除を行った．摘出標本では腫瘍は空腸に瘻孔を形成していた．術後11カ月で肝・肺転移再発を認めた．症例3は71歳の女性．S状結腸癌，結腸十二指腸瘻と診断し，S状結腸切除，十二指腸合併切除術を施行した．術後3カ月で肝転移再発を認めた．瘻孔形成大腸癌は腹膜播種，肝転移，リンパ節転移の頻度が低く，根治切除で良好な予後が見込めるとする報告が多いが，経験した3例とも再発を認めており，進行度に準じた慎重な経験観察が必要である．

Limited pulmonary resection is performed mostly based on the size of lung cancer and ground-glass opacity (GGO). It has been proposed to determine the indication of segmentectomy according to hilar lymph node involvement. There is a potential risk of underestimation for lymph node involvement since there may be a skip mediastinal lymph node metastasis without hilar involvement. We propose to use standardized uptake value( SUV) max of primary lung cancer as an indicator of non-invasive lung cancer. None of 44 small-sized lung cancers with SUVmax lower than 1 had lymph node metastasis or vessel invasion. A small-sized lung cancer ≤ 2 cm with SUVmax ≤ 1 is indicated wedge resection if GGO area is greater than 75% of tumor. Segmentectomy is indicated if the GGO area is less than 75%. We also propose selective lymphadenectomy for small-sized lung cancer. The lower mediastinal lymphadenectomy may be omitted if a small-sized tumor is located in the right upper lobe or the left upper segment. The upper mediastinal lymphadenectomy may be omitted if a small-sized lung cancer is located in the lower lobe and if the lower mediastinal lymph node involvement is excluded.

It is recognized that hormone receptors and HER2 are important as prognostic factors in breast cancer. Moreover, it seems likely that hormone receptors and HER2 are important predictive factors for response to chemotherapy in breast cancer. We report a case of bilateral T4 breast cancer with different expression for hormone receptors and HER2. The patient was a 67-year-old woman. The Stage was T4bN2aM0, respectively. The right tumor was negative for hormone receptors and positive for HER2, while the left tumor was positive for hormone receptors and negative for HER2. After primary chemotherapy with FEC, paclitaxel and docetaxel, the efficacy for the right local tumor was judged as cCR. However, brain metastases appeared and were treated by resection and radiation. The efficacy for the left tumor was judged as PR. Modified radical mastectomy with axillary lymph node dissection was performed. The patient has survived with no recurrence.