Development of an ultralow-latency communication system using shared internet access: promoting the implementation of telemedicine.

Telemedicine is becoming increasingly important to address the shortage of gastrointestinal surgeons and disparities in domestic and international treatment outcomes for patients with colorectal cancer. The development of a low-latency communication system using existing communication infrastructure (shared internet access: SIA) is necessary to promote the use of telemedicine. The aim of this study was to develop a low-latency communication system using SIA. We conducted an experiment between Sapporo and Tokyo using an ultralow-latency communication system for remote medical education (TELEPRO®). The latency was measured using 2000 annotations from a monitor in Sapporo, which confirmed a median latency of 27.5 ms. A low-latency communication system based on SIA with latency lower than the maximum allowable latency for telemedicine was developed successfully.

Clinical Utility and Characteristics of the LARS Score Compared to the CCIS.

PURPOSE: The low anterior resection syndrome (LARS) score (LS) has been widely validated and has become an international tool for evaluating postoperative bowel dysfunction. However, many physicians still use the conventional incontinence scores in LARS treatment. Moreover, interpretation of LS and its relationship with conventional incontinence scores are not yet well understood. Here we compared the LS with the Cleveland Clinic Incontinence Score (CCIS) to clarify the clinical utility and characteristics of the LARS score. METHODS: We performed a multicentre observational study, recruiting 246 rectal cancer patients following sphincter-preserving surgery. Patients completed the LS, CCIS, and SF36 questionnaires. RESULTS: The response rate was 76.4%, and a total of 180 patients were analysed. The LS was strongly correlated with the CCIS (P < 0.001, rs = 0.727). However, among 116 patients determined to not have incontinence (CCIS 0-5), 51 (44%) were diagnosed with LARS (29 with minor LARS and 22 with major LARS). Among 68 patients without LARS, only 3 were diagnosed as having incontinence (CCIS > 6). In comparison with background factors, aging and elapsed time were associated with only LS. High LS and CCIS both showed significant quality-of-life impairment as assessed by the SF-36. CONCLUSION: This is the first study to determine the difference in the numeric values between the CCIS and LS. The LS can be a convenient tool for LARS screening, identifying a wide range of patients with LARS, including those with incontinence evaluated by CCIS. Assessment using the CCIS may often underestimate LARS.

Timing of indocyanine green injection prior to laparoscopic colorectal surgery for tumor localization: a prospective case series.

BACKGROUND: Accurate identification of tumor sites during laparoscopic colorectal surgery helps to optimize oncological clearance. We aimed to assess the timing of the local injection preoperatively and clarify the usefulness and limitation of tumor site marking using indocyanine green (ICG) fluorescence imaging. METHODS: Consecutive patients who underwent primary colorectal cancer surgery from September 2017 to January 2019 were included. Preoperatively, lower endoscopy was used to inject the ICG solution into the submucosal layer near the tumor. During laparoscopic surgery, ICG fluorescence marking as the tumor site marking was detected using a laparoscopic near-infrared camera system. The detection rate and factors associated with successful intraoperative ICG fluorescence visualization including the interval between local injection and surgery were evaluated. RESULTS: One hundred sixty-five patients were enrolled. Using the laparoscopic near-infrared system, the intraoperative detection rates of ICG marking were 100% for ICG injection within 6 days preoperatively, 60% for injection between 7 and 9 days preoperatively, and 0% for injection earlier than 10 days preoperatively. There were no complications associated with ICG marking. Additionally, this method did not disturb the progress of the surgical procedure because injected ICG in the submucosal layer did not cause any tissue inflammation, and if ICG spilled into the serosa, it was invisible by white light. CONCLUSION: Advantages of ICG fluorescence tumor site marking were high visibility of infrared imaging during laparoscopic colorectal surgery and minimal adverse events of surgery. One of the most important findings regarding practical use was a rapid decrease in fluorescence marking visibility if one week passed from the time of ICG local injection.

MRI-detected extramural vascular invasion potentiates the risk for pathological metastasis to the lateral lymph nodes in rectal cancer.

PURPOSE: Multidisciplinary treatment for locally advanced rectal cancer requires an accurate assessment of the risk of metastasis to the lateral lymph nodes (LNs). We herein aimed to stratify the risk of pathological metastasis to lateral LNs based on the preoperatively detected malignant features. METHODS: All patients with rectal cancer who underwent surgery from January 2016 to July 2020 were identified. We recorded the TNM factors; perirectal and lateral LN sizes; and MRI findings, including mesorectal fascia involvement, extramural vascular invasion (EMVI), tumor site, and tumor distance from the anal verge. RESULTS: 101 patients underwent rectal resection with lateral lymph node dissection, of whom 16 (15.8%) exhibited pathological metastases to the lateral LNs. Univariate analyses demonstrated that lateral LN metastasis was significantly correlated with mrEMVI positivity (p = 0.0023) and a baseline lateral LN short-axis length of ≥ 5 mm (p < 0.0001). These significant associations were confirmed by a multivariate analysis (p = 0.0254 and 0.0027, respectively). The lateral LN metastasis rate was as high as 44% in cases bearing both risk factors, compared to 0% in cases lacking both risk factors. CONCLUSION: The results elucidated in this study may contribute to risk stratification, which can be used when determining the indications for lateral lymph node dissection.

Efficacy of indocyanine green fluorescence angiography in preventing anastomotic leakage after laparoscopic colorectal cancer surgery.

PURPOSE: Some recent studies have suggested that fluorescence angiography with indocyanine green (ICG) might be useful for preventing anastomotic leakage (AL) after laparoscopic colorectal surgery. However, its efficacy has not been proven. We evaluated whether intraoperative ICG fluorescence angiography could decrease the AL rate with laparoscopic colorectal cancer surgery. METHODS: This retrospective study included patients with colorectal cancer who underwent laparoscopic surgery at our institution between March 2014 and December 2018. Patients were divided into two groups: with or without ICG fluorescence angiography. The primary outcome was the rate of AL. RESULTS: A total of 488 patients were included: 223 patients in the ICG group and 265 patients in the no-ICG group. In the ICG group, the transection line was changed to a more proximal location in seven patients (3.1%), including one patient with transverse colon surgery and six with rectal surgery. None of these seven patients developed AL. There were 18 ALs (3.7%) overall. The AL rate was 1.8% in the ICG group and 5.3% in the no-ICG group. For colon cancer, there were no significant differences in the AL rate between the groups (p = 0.278). In rectal cancer, the AL rate was significantly lower in the ICG group than in the no-ICG group (3.5% vs. 10.5%, p = 0.041). After propensity score matching, the AL rate was also significantly lower in the ICG group for rectal cancer (p = 0.044). CONCLUSION: ICG fluorescence angiography can potentially reduce the AL rate with laparoscopic rectal cancer surgery.

Evaluation of negative-pressure wound therapy for surgical site infections after ileostomy closure in colorectal cancer patients: a prospective multicenter study.

PURPOSE: Surgical site infection (SSI) occurs at a high rate after ileostomy closure. The effect of preventive negative-pressure wound therapy (NPWT) on SSI development in closed wounds remains controversial. We conducted a prospective multicenter study to evaluate the usefulness of preventive NPWT for SSI after ileostomy closure. METHODS: From January 2018 to November 2018, 50 patients who underwent closure of ileostomy created after surgery for colorectal cancer participated in this study. An NPWT device was applied to each wound immediately after surgery and then treatment was continued for 3 days. The primary endpoint was 30-day SSI, and the secondary endpoints were the incidence of seroma, hematoma, and adverse events related to NPWT. RESULTS: No patients developed SSI, seroma, or hematoma. Adverse events that may have been causally linked with NPWT were contact dermatitis in two patients and wound pain in one patient, and there were no cases of discontinuation or decompression of NPWT. CONCLUSION: The use of NPWT following ileostomy closure may be useful for reducing the development of SSI in colorectal cancer patients. This is a prospective multicenter pilot study and we are planning a comparative study based on these successful results. TRAIL REGISTRATION: Registration number: UMIN000032053 ( https://www.umin.ac.jp/ ).

Validation of the Japanese Version of the Low Anterior Resection Syndrome Score.

BACKGROUND: The low anterior resection syndrome (LARS) score is a patient-reported outcome measure to evaluate the severity of bowel dysfunction after rectal cancer surgery by scoring the major symptoms of LARS. The aim of this study was to translate the English version of the LARS score into Japanese and to investigate the validity and reliability of the LARS score. METHODS: The LARS score was translated in Japanese following current international recommendations. A total of 149 rectal cancer patients completed the LARS score questionnaire and were also asked a single question assessing the impact of bowel function on quality of life (QoL). A total of 136 patients answered the LARS score questionnaire twice. RESULTS: The Japanese LARS score showed high convergent validity, based on its good correlation between the LARS score and QoL (p < 0.001). The LARS score was able to discriminate between patients according to the tumor distance to anal verge (p < 0.001), type of surgery (p < 0.001), and time since surgery (p = 0.001). Patients after ultra-low anterior resection and intersphincteric resection showed especially high scores. The score also had high test-retest reliability (intraclass correlation coefficient: 0.87). CONCLUSION: The Japanese LARS score is a valid and reliable tool for measuring LARS. The LARS score is appropriate for assessments in postoperative bowel function and international comparison. Using this score, patient-reported outcome measures of LARS in Japanese patients can be shared internationally. Additional validation reports from non-English speaking countries can support the LARS score as a worldwide assessment tool for postoperative bowel dysfunction.

Clinical feasibility of laparoscopic lateral pelvic lymph node dissection following total mesorectal excision for advanced rectal cancer.

PURPOSE: To evaluate the technical feasibility, safety and oncological outcomes of laparoscopic lateral pelvic lymph node dissection in patients with advanced low rectal cancer. METHODS: Laparoscopic lateral pelvic lymph node dissection was performed in 18 patients from November 2009 to September 2012. The data regarding the patient demographics, surgical outcomes and short-term oncological outcomes were analyzed. RESULTS: In all 18 patients, the procedures were completed without conversion to open surgery. The mean length of the operation was 603.7 min (473-746 min). The mean number of harvested lateral pelvic lymph nodes was 16.9 (7-27), and five patients (27.8 %) had lymph node metastases. The postoperative mortality and morbidity rates were 0 and 16.7 %, respectively. Three patients developed Grade 2 urinary retention. No local recurrence had developed after a mean follow-up period of 23.6 months. CONCLUSION: Laparoscopic lateral pelvic lymph node dissection is technically feasible, safe and oncologically acceptable within the limitations of the short-term follow-up period.

Hybrid Abdominal Robotic Approach Using the hinotori™ Surgical Robot System with Transanal Total Mesorectal Excision for Rectal Cancer: The First Ever Case Report for Rectal Cancer.

In Japan, the hinotori™ Surgical Robot System obtained pharmaceutical approval for use in colorectal cancer surgery in October 2022. This system has an operating arm with eight axes, adjustable arm base, and flexible three-dimensional viewer, which are expected to be advantageous in colorectal cancer surgery. A 55-year-old man presented to our hospital with melena and was diagnosed with cStage IIA (cT3N0M0) rectal cancer. The patient underwent intersphincteric resection using hinotori™ Surgical Robot System. Appropriate port placement was available for rectal manipulation, lymph node dissection, and arm base angle adjustment. Herein, we report the world's first rectal cancer surgery using the hinotori™ Surgical Robot System with TaTME by two teams.

Cylindrical abdominoperineal resection for rectal cancer using the Hugo RAS system: The first ever case report for rectal cancer.

In May 2023, the Hugo RAS system obtained pharmaceutical approval for use in gastroenterological surgery in Japan. It is expected to be particularly effective in rectal cancer surgery, which require the manipulation of the deep pelvic cavity and communication with surgeons operating from the intraperitoneal and anal approaches. A 68-year-old woman presented to our hospital with bloody stools and was diagnosed with cStage I (cT2N0M0) rectal cancer and underwent abdominoperineal resection employing the Hugo RAS system. Two arm carts were placed on the left and right lateral sides with an interleg space, and trocars were placed in a straight line between the right superior iliac spine and umbilicus. Herein, we report the first abdominoperineal resection for rectal cancer using the Hugo RAS system.

A first report of right-hemicolectomy for ascending colon cancer in Japan with the da Vinci SP surgical robot system.

BACKGROUND: The da Vinci SP robotic surgical system received regulatory approval for use in colorectal cancer surgery in Japan in April 2023. Given the advantages of the precision of a robot and the postoperative cosmesis of single-site surgery, the system is expected to be further utilized for minimally invasive surgeries, in addition to the curative and safety-assured laparoscopic technique. CASE PRESENTATION: A 73-year-old man presented at our hospital with positive fecal occult blood. He was diagnosed with cT2N0M0 (Stage I) ascending colon cancer and underwent a right hemicolectomy, which was performed with the da Vinci SP system. The operation was performed safely, and the patient was discharged without complications. Pathology findings showed that complete mesocolic excision was achieved. CONCLUSIONS: Herein, we report the first colorectal cancer surgery performed using the da Vinci SP system in Japan. The use of this robotic surgical system with access forms for right hemicolectomy is safe and oncologically appropriate.

Tele-proctoring for minimally invasive surgery across Japan: An initial step toward a new approach to improving the disparity of surgical care and supporting surgical education.

Aim: The aim of this study was to verify the clinical feasibility of tele-proctoring using our ultra-low latency communication system with shared internet access. Methods: Connections between two multiple remote locations at various distances were established through the TELEPRO® tele-proctoring system. The server records the latency between the two locations for tele-proctoring using the annotations. Questionnaires were administered to the surgeons, assistants, and medical staff. Respondents rated the quickness and quality of communication in terms of latency and disturbances in the audio, video, and usefulness of the live telestrations with annotation. Results: Seven hospitals tele-proctored with Sapporo Medical University between January 2021 and September 2022. The median latency of annotation between the two locations ranged from 24.5 to 48.5 ms. No major technological problems occurred, such as streaming interruption, loss of video or audio, poor resolution. The video encoding time was 10 ms, and its decoding time was 0.8 ms. The total latency positively correlated with the distance between two locations (R = 0.55, p < 0.01). The quality of communication regarding latency, disturbance, and surgical education with intraoperative annotative instructions showed similar trends, with perfectly fine being the most common response. No significant differences in surgical quality, educational effect, or social impact were observed between the latency ≥30 and <30 ms groups for whether the size of latency affects surgical education. Conclusion: The feasibility of the tele-proctoring system is expected to be a sustainable approach to help education for young surgeons and surgical supports in rural areas, thereby reducing disparities in health care.

CD8-positive T Cell Infiltration With Human Leukocyte Antigen Class 1 Expression Predicts Patients With Stage IV Colorectal Cancer Survival.

BACKGROUND/AIM: The immune microenvironment in cancer correlates with cancer progression and patient prognosis. Cancer immune microenvironment evaluation, based on CD3+ and CD8+ T cell infiltration at the center and invasive margin of the tumor, is defined as the immunoscore. An international multicenter analysis revealed that the immunoscore can accurately predict the prognosis of patients with colorectal cancer (CRC) (stage I, II, and III). However, no markers are currently available to predict the prognosis in patients with stage IV CRC. We thus aimed to analyze the immune microenvironment in patients with stage IV CRC in this study. PATIENTS AND METHODS: We analyzed the immune microenvironment of patients with stage IV CRC using immunohistochemical (IHC) staining. We evaluated the expressions of CD8 and the cases were divided into CD8 high (CD8Hi) and CD8 low (CD8Low) groups according to median CD8 expression. HLA class 1 (HLA1) expression was also evaluated using IHC staining and the cases were divided into HLA1Hi group and HLA1Low group according to 50% of HLA1 expression rate. CD8×HLA1 score was defined by the combination of CD8 and HLA1 expressions. RESULTS: CD8Hi and HLA1Hi cases were associated with better prognosis compared with CD8Low and HLA1Low cases according to a log-rank test, respectively. We defined a novel biomarker by combining CD8+ T-cell infiltration and HLA1 expression, referred to as the CD8×HLA1 score. We found that CD8×HLA1Hi cases predicted patient prognosis better than CD8×HLA1Int and CD8×HLA1Low according to a log-rank test. CONCLUSION: The combination of CD8+ T cell infiltration and HLA1 expression is crucial for cancer immune microenvironment evaluation in CRCs.

Essential updates 2020/2021: Advancing precision medicine for comprehensive rectal cancer treatment.

In the paradigm shift related to rectal cancer treatment, we have to understand a variety of new emerging topics to provide appropriate treatment for individual patients as precision medicine. However, information on surgery, genomic medicine, and pharmacotherapy is highly specialized and subdivided, creating a barrier to achieving thorough knowledge. In this review, we summarize the perspective for rectal cancer treatment and management from the current standard-of-care to the latest findings to help optimize treatment strategy.

Right hemicolectomy for ascending colon cancer using the hinotori surgical robot system: The first ever case report for colon cancer.

The hinotori Surgical Robot System obtained pharmaceutical approval for use in colorectal cancer surgery in October 2022 in Japan, and its advantages, including its operating arm with eight axes, adjustable arm base, and flexible 3D viewer, are expected to be utilized in colon cancer surgery. A 68-year-old woman presented to our hospital with abdominal pain and was diagnosed with cStageIIa (cT3N0M0) ascending colon cancer and underwent right hemicolectomy using the hinotori Surgical Robot System with the appropriate port placement on the arc around the hepatic flexure, which was available for both ileocecal manipulation and lymph node dissection, and adjustment of the angle of the arm base to further reduce interference. Herein we report the world's first surgery for colorectal cancer using the hinotori Surgical Robot System.

World-first report of low anterior resection for rectal cancer with the hinotori™ Surgical Robot System: a case report.

BACKGROUND: The hinotori™ Surgical Robot System was approved for use in colorectal cancer surgery in Japan in 2022. This robot has advantages, such as an operation arm with eight axes, an adjustable arm base, and a flexible three-dimensional viewer, and is expected to be utilized in rectal cancer surgery. Herein, we report the world's first surgery for rectal cancer using the hinotori™ Surgical Robot System. CASE PRESENTATION: A 71-year-old woman presented to our hospital with bloody stools. A colonoscopy revealed type 2 advanced cancer in the rectum, and a histological examination exposed a well-differentiated adenocarcinoma. Abdominal enhanced computed tomography divulged rectal wall thickening without significant swelling of the lymph nodes or distant metastasis. Pelvic magnetic resonance imaging showed tumor invasion beyond the intrinsic rectal muscle layer. The patient was diagnosed with cStage IIa (cT3N0M0) rectal cancer and underwent low anterior resection using the hinotori™ Surgical Robot System. Based on an adequate simulation, surgery was safely performed with appropriate port placement and arm base-angle adjustment. The operating time was 262 min, with a cockpit time of 134 min. Subsequently, the patient was discharged 10 days postoperatively without complications. The pathological diagnosis was pStage IIA (cT3N0M0) and the circumferential resection margin was 6 mm. CONCLUSIONS: We report the first case of low anterior resection for rectal cancer using the hinotori™ Surgical Robot System, in which a safe and appropriate oncological surgery was performed.

Short-Term Outcomes with Standardized Transperineal Minimally Invasive Abdominoperineal Excision for Rectal Cancer.

BACKGROUND: Transperineal abdominoperineal excision (TpAPE) is an emerging approach for low rectal cancers but is technically challenging. Based on an anatomical study we conducted previously, we have standardized the TpAPE procedure. Here, we aimed to validate the feasibility of the standardized TpAPE by investigating the short-term outcomes. METHODS: From January 2018 to November 2020, a total of 405 patients underwent laparoscopic or robotic rectal resection for rectal cancer in our institution. For the current study, we analyzed data for the 31 patients who underwent TpAPE. The abdominal phase was performed synchronously with the perineal phase using either a laparoscopic or robotic approach. Short-term outcomes included operative and pathological results. RESULTS: Of the 31 cases, we identified anterior quadrant tumor invasion in 21. Most of the cases were advanced, with 6 staged as cT3 and 20 as T4. Of the 27 cases not involving distant metastasis, neoadjuvant therapy was performed in 19. No inadvertent rectal perforation or urethral injury was found intraoperatively. The median procedural duration to specimen removal was 250 min (interquartile range, 204-287), and the median intraoperative blood loss was 10 ml (interquartile range, 5-40). Regarding postoperative complications, perineal wound infection developed in 11 cases. A positive circumferential resection margin was found in 3, corresponding to the positive rate of 9.7%. These three cases were among the first 12 cases involving standardized TpAPE. CONCLUSIONS: The current results indicate that TpAPE can be performed safely and might represent a useful option for low rectal cancer resection.

Artificial intelligence-based technology to make a three-dimensional pelvic model for preoperative simulation of rectal cancer surgery using MRI.

Aim: A new technique that allows visualization of whole pelvic organs with high accuracy and usability is needed for preoperative simulation in advanced rectal cancer surgery. In this study, we developed an automated algorithm to create a three-dimensional (3D) model from pelvic MRI using artificial intelligence (AI) technology. Methods: This study included a total of 143 patients who underwent 3D MRI in a preoperative examination for rectal cancer. The training dataset included 133 patients, in which ground truth labels were created for pelvic vessels, nerves, and bone. A 3D variant of U-net was used for the network architecture. Ten patients who underwent lateral lymph node dissection were used as a validation dataset. The correctness of the vascular labelling was assessed for pelvic vessels and the Dice similarity coefficients calculated for pelvic bone. Results: An automatic segmentation algorithm that extracts the artery, vein, nerve, and pelvic bone was developed, automatically producing a 3D image of the entire pelvis. The total time needed for segmentation was 133 seconds. The success rate of the AI-based segmentation was 100% for the common and external iliac vessels, but the rates for the vesical vein (75%), superior gluteal vein (60%), or accessory obturator vein (63%) were suboptimal. Regarding pelvic bone, the average Dice similarity coefficient between manual and automatic segmentation was 0.97 (standard deviation 0.0043). Conclusion: Though there is room to improve the segmentation accuracy, the algorithm developed in this study can be utilized for surgical simulation in the treatment of advanced rectal cancer.

Defecation disorder and anal function after surgery for lower rectal cancer in elderly patients.

AIM: This study aims to investigate the association of patient age with defecation disorders and anal function after lower rectal cancer surgery. METHODS: We retrospectively reviewed the data of 141 consecutive patients with lower rectal cancer who underwent sphincter-preserving operation. The patients were classified into five categories by age thresholds at 65, 70, 75, 80, and 85 years, for disaggregate analysis. Anal manometry was used for measuring the maximum resting pressure, high-pressure zone, and maximum squeeze pressure. Anal manometry was performed preoperatively and at 3, 6, 9, and 12 months postoperatively. The Wexner and low anterior resection syndrome scores were assessed at 1, 3, 6, 9, and 12 months after rectal surgery or stoma closure for patients with ileostomy. RESULTS: The data of 117 patients were reviewed. No significant differences were found between the younger and elderly groups in any characteristics across the six age groups. The preoperative intra-anal pressures of the elderly patients were slightly lower than those of the younger patients; however, there was no significant difference in the course of postoperative intra-anal pressures. Defecation disorder, as measured by the Wexner and low anterior resection syndrome scores, improved significantly in elderly patients compared to younger patients. CONCLUSION: There was no significant difference in the course of postoperative intra-anal pressures between the elderly and younger patients. However, defecation disorders in elderly patients significantly improved compared with younger patients. Sphincter-preserving operation can be a viable treatment option for active elderly patients.

A modified method for resected specimen processing in rectal cancer: Semi-opened with transverse slicing for measuring of the circumferential resection margin.

Circumferential resection margin (CRM) is essential for oncological quality assessment in rectal cancer surgery. CRM represents a surrogate parameter for oncological outcomes and is important for stratifying treatment strategies in Western nations. In Japan, the mesentery is removed for specimen processing in order to extract as many lymph nodes (LNs) as possible; consequently, CRM cannot be measured. Given the diversification of treatment strategies for rectal cancer, the lack of measurement of CRM to assess surgical outcomes is a crucial issue that must be resolved. Therefore, it is necessary to establish a method enabling measurement of CRM while enjoying the advantages of the Japanese method. In the method we developed, the mesentery is removed from the rectum more than 2 cm away from the tumor, and the vicinity of the tumor is circularized. It is necessary to investigate the usefulness of this method prospectively in a multi-center study.