Long-term outcomes of robot-assisted versus minimally invasive esophagectomy in patients with thoracic esophageal cancer: a propensity score-matched study.

BACKGROUND: Recently, robot-assisted minimally invasive esophagectomy (RAMIE) has gained popularity worldwide. Some studies have compared the long-term results of RAMIE and minimally invasive esophagectomy (MIE). However, there are no reports on the long-term outcomes of RAMIE in Japan. This study compared the long-term outcomes of RAMIE and MIE. METHODS: This retrospective study included 86 patients with thoracic esophageal cancer who underwent RAMIE or MIE at our hospital from June 2010 to December 2016. Propensity score matching (PSM) was employed, incorporating co-variables such as confounders or risk factors derived from the literature and clinical practice. These variables included age, sex, body mass index, alcohol consumption, smoking history, American Society of Anesthesiologists stage, comorbidities, tumor location, histology, clinical TNM stage, and preoperative therapy. The primary endpoint was 5-year overall survival (OS), and the secondary endpoints were 5-year disease-free survival (DFS) and recurrence rates. RESULTS: Before PSM, the RAMIE group had a longer operation time (min) than the MIE group (P = 0.019). RAMIE also exhibited significantly lower blood loss volume (mL) (P < 0.001) and fewer three-field lymph node dissections (P = 0.028). Postoperative complications (Clavien-Dindo: CD ≥ 2) were significantly lower in the RAMIE group (P = 0.04), and postoperative hospital stay was significantly shorter than the MIE group (P < 0.001). After PSM, the RAMIE and MIE groups consisted of 26 patients each. Blood loss volume was significantly smaller (P = 0.012), postoperative complications (Clavien-Dindo ≥ 2) were significantly lower (P = 0.021), and postoperative hospital stay was significantly shorter (P < 0.001) in the RAMIE group than those in the MIE group. The median observation period was 63 months. The 5-year OS rates were 73.1% and 80.8% in the RAMIE and MIE groups, respectively (P = 0.360); the 5-year DFS rates were 76.9% and 76.9% in the RAMIE and MIE groups, respectively (P = 0.749). Six of 26 patients (23.1%) in each group experienced recurrence, with a median recurrence period of 41.5 months in the RAMIE group and 22.5 months in the MIE group. CONCLUSIONS: Compared with MIE, RAMIE led to no differences in long-term results, suggesting that RAMIE is a comparable technique.

[A Case of Early-Stage Cecal Cancer with Mesenteric Phlebosclerosis Requiring Laparoscopic Right Hemicolectomy of the Colon].

The patient was a 71-year-old woman diagnosed with mesenteric phlebosclerosis(MP)2 years earlier. CT performed to investigate her abdominal pain revealed an ascending colon obstruction. Colonoscopy(CS)revealed MP extending to the ascending colon hepatic flexure with stenosis and a cecal tumor(biopsy tub1). Although the cancerous lesion itself was potentially curable by endoscopic treatment, it was surgically resected because of the ascending colon stenosis caused by the MP that had also caused intestinal obstruction. Intraoperative findings revealed wall thickening and stiffening from the cecum to the ascending colon hepatic flexure. Postoperative pathological examination revealed cecal carcinoma pTis, N0, M0, pStage 0. The background mucosal tissue was consistent with MP, but no findings suggested a relationship between the MP and tumor. Although the relationship between MP and carcinogenesis is unknown, and no such relationship was identified in this case, we report this case because a further accumulation of cases of MP and carcinoma is necessary, considering the rarity of MP itself and the non-negligible number of cases with carcinoma.

A case of premortem diagnosis of cardiac tamponade due to pericardial metastasis of rectal cancer.

Colorectal cancer rarely develops pericardial metastasis, and it is an extremely rare case that cardiac tamponade due to the metastasis of colorectal cancer during life. Our case is of a 50-year-old woman who underwent laparoscopic lower anterior resection for the rectal cancer with lung metastasis 4 years ago developed cardiac tamponade due to pericardial metastasis of rectal cancer. We performed pericardiocentesis as a temporary life-saving procedure, but pericardial fluid re-accumulated within a few days. She died 23 days after admission. When a patient with advanced colorectal cancer complains dyspnea, we should consider the pericardial metastasis, and perform the proper treatment as this case.

[Preoperative Prognostic Factors in CRS plus HIPEC for Patients with Peritoneal Dissemination of Colorectal Cancer].

Peritoneal dissemination of colorectal cancer has the poorest prognosis among metastatic sites, with an average overall survival of less than 6 months. Various treatment methods have been reported for these patients, and recently there have been several reports showing the usefulness of cytoreductive surgery(CRS)combined with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the studies on this treatment are limited. In this study, we retrospectively reviewed cases of CRS plus HIPEC. Twenty-one patients who underwent CRS plus HIPEC at Tokyo Medical University Hospital and Toda Central General Hospital between August 2014 and December 2017 were included in this study. The long-term and short-term survival groups were analyzed separately, and predictors of preoperative treatment efficacy were examined. The surgical approach was open in 16 cases and laparoscopic in 5 cases. Complete resection was achieved in 10 of these patients. Postoperative complications occurred in 6 patients. There were no deaths within 90 days of surgery. The median overall survival was 17.0 months, and the 1-year survival rate was 65%. Median progression-free survival was 11.0 months. In a multivariate analysis predicting long-term versus short-term survival groups, sex, primary tumor location, and P factor were independent predictors of treatment response. CRS plus HIPEC therapy is considered an effective treatment option. The predictors of preoperative treatment response include sex, primary tumor location, and P factor.

[A Case of Rectal Cancer with Solitary Lymph Node Metastasis in the Stomach after Hepatectomy for Liver Metastasis].

A 44-year-old woman had undergone a laparoscopic low anterior resection and lymph node dissection for rectal cancer (pT4aN2aH0P0M0, pStage Ⅲc)in 20XX. Six months postoperatively, a CT scan revealed recurrent liver metastasis. She underwent surgery and adjuvant chemotherapy. Three years after the initial surgery, her liver metastasis recurred again, and the patient underwent another cycle of surgical treatment and adjuvant chemotherapy. Five years after the initial surgery, a lesion was found in a gastric lesser curvature lymph node. Gastric kyphosis lymph node dissection was performed under the suspicion of a solitary lymph node metastasis. The resected lymph node was diagnosed as a medium-differentiated adenocarcinoma, with findings consistent with a lymph node metastasis from the initial rectal cancer. Postoperative adjuvant chemotherapy was administered. No recurrence was noted 6 years and 6 months after the initial surgery. Rectal cancer rarely metastasizes to the gastric lymph nodes in a solitary fashion. We describe a case of a solitary gastric regional lymph node metastasis observed after the resolution of previous liver metastases.

Effectiveness of a new triple-row circular stapler in reducing the risk of colorectal anastomotic leakage: A historical control and propensity score-matched study.

Anastomotic leakage (AL) after colorectal surgery is a serious complication. This study aimed to evaluate the effectiveness of the EEA™ circular stapler, a new triple-row circular stapler (TCS), relative to a conventional, double-row circular stapler (DCS). A total of 285 patients who underwent anastomosis with the double stapling technique at the Tokyo Medical University Hospital between 2017 and 2021 were included in this nonrandomized clinical trial with historical controls using a propensity score (PS) analysis. The primary endpoint was the risk of AL. We performed a 1:2 PS matching analysis. Before case matching, AL occurred in 15 (7.4%) and 2 (2.4%) patients in the DCS and TCS groups, respectively, with no significant difference (P = .17). After case matching, AL occurred in 13 patients (11.6%) and 1 patient (1.8%) in the DCS and TCS groups, respectively, revealing a significant difference (P = .04). Cox models were created by applying PS to adjust for group differences via regression adjustment. Odds ratios for AL in the DCS group versus the TCS group were 0.31 (95% confidence interval [CI]: 0.07-1.38) in the entire cohort, 0.15 (95% CI: 0.02-0.64) in the regression adjustment cohort, and 0.14 (95% CI: 0.02-1.09) in the 1:2 PS-matched cohort. PS analysis of clinical data suggested that the use of TCS contributes to a reduced risk of AL after colorectal anastomosis CTwith the double stapling technique.

Comparison of pressure resistance of double-rows and triple-rows circular stapler in rectal double stapling technique: In vitro study.

BACKGROUND: Anastomotic leak after gastrointestinal anastomosis is a serious complication. Anastomotic failure depends on various parameters. The aim of our study was to evaluate the pressure resistance of a new device, EEA™ circular stapler with Tri-Staple™ technology 28 mm Medium/Thick (Triple-rows circular stapler; TCS) compared with EEA™ circular stapler with DST series™ technology 28 mm, 4.8 mm staples (double-rows circular stapler; DCS). PATIENTS AND METHODS: We performed 30 anastomoses (DSC: 15, TCS: 15) of DST with porcine colon model in vitro. We performed following 3 comparative experiences; Experiment 1: observation of staple shape with a colonoscopy, Experiment 2: comparison of the pressure resistance, Experiment 3: comparison of leakage points. RESULTS: There was no hypoplasia of staples and the shapes were well-formed by colonoscopy. The leakage pressure of DCS was 19.6 ±â€…4.4 mm Hg (mean ±â€…standard deviation) and that of TCS was 38.6 ±â€…10.2 mm Hg (mean ±â€…standard deviation). There was a significantly difference between 2 groups (P < .001). 12 cases of DCS (80%) and 10 cases of TCS (66.7%) had leakages from Circular stapler point. 2 cases of DCS (13.3%) and 5 cases of TCS (33.3%) had leakages from Crossing points. Only 1 case of DCS had leakages from Dog ear point (6.7%). There was no significantly difference in leakage site between 2 groups (P = .195). CONCLUSIONS: TSC showed high pressure resistance during DST compared with that of DCS. It was suggested that TCS may contribute to the reduction of anastomotic leakage rate.

Salivary metabolomics with machine learning for colorectal cancer detection.

As the worldwide prevalence of colorectal cancer (CRC) increases, it is vital to reduce its morbidity and mortality through early detection. Saliva-based tests are an ideal noninvasive tool for CRC detection. Here, we explored and validated salivary biomarkers to distinguish patients with CRC from those with adenoma (AD) and healthy controls (HC). Saliva samples were collected from patients with CRC, AD, and HC. Untargeted salivary hydrophilic metabolite profiling was conducted using capillary electrophoresis-mass spectrometry and liquid chromatography-mass spectrometry. An alternative decision tree (ADTree)-based machine learning (ML) method was used to assess the discrimination abilities of the quantified metabolites. A total of 2602 unstimulated saliva samples were collected from subjects with CRC (n = 235), AD (n = 50), and HC (n = 2317). Data were randomly divided into training (n = 1301) and validation datasets (n = 1301). The clustering analysis showed a clear consistency of aberrant metabolites between the two groups. The ADTree model was optimized through cross-validation (CV) using the training dataset, and the developed model was validated using the validation dataset. The model discriminating CRC + AD from HC showed area under the receiver-operating characteristic curves (AUC) of 0.860 (95% confidence interval [CI]: 0.828-0.891) for CV and 0.870 (95% CI: 0.837-0.903) for the validation dataset. The other model discriminating CRC from AD + HC showed an AUC of 0.879 (95% CI: 0.851-0.907) and 0.870 (95% CI: 0.838-0.902), respectively. Salivary metabolomics combined with ML demonstrated high accuracy and versatility in detecting CRC.

A new technique for robotic lateral pelvic lymph node dissection for advanced low rectal cancer with emphasis on en bloc resection and inferior vesical vessel preservation.

BACKGROUND: Lateral pelvic lymph node (LPLN) dissection is becoming increasingly important in the treatment of advanced low rectal cancer patients. However, the surgery has several disadvantages, including its technical complexity and high risk of urinary dysfunction. Herein, we report a new technique for robotic lateral pelvic lymph node dissection for advanced low rectal cancer with emphasis on en bloc resection and inferior vesical vessel preservation. METHODS: Robotic LPLN dissection was performed in 12 consecutive patients between April 2020 and December 2021. Six surgical ports were placed in the abdomen under general anesthesia. Fascia-oriented LPLN dissection of the internal iliac region and obturator region was performed using the ureterohypogastric nerve fascia, vesicohypogastric fascia, and internal obturator muscles as anatomical landmarks. Lymph nodes were resected en bloc via the caudal side of the inferior vesical vessels. The inferior vesical vessels were spared to prevent urinary dysfunction. RESULTS: The median patient age was 62 years (range, 43-82 years), and eight patients were male. The median operative time was 498 min (range, 424-661 min), the median bleeding volume was 56 ml (range, 13-467 ml), and the median number of harvested LPLN was 16 (range, 1-70). The conversion rate to open surgery was 0%. Clavien-Dindo Grade ≥ II urinary dysfunction rated was not observed. CONCLUSION: A new technique for robotic LPLN dissection for advanced low rectal cancer with emphasis on en bloc resection and inferior vesical vessel preservation can be safely performed, making it a promising surgical procedure.

Nucleic Acid Metabolizing Enzyme Levels Predict Chemotherapy Effects in Advanced and Recurrent Colorectal Cancer.

BACKGROUND: Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) predict the effects of fluoropyrimidine. However, the effects of FOLFOX therapy from the perspective of fluorouracil plus leucovorin (FL) remain underexplored. Hence, the relationship between mFOLFOX6 therapy (mFOLFOX6) and therapeutic efficacy was evaluated in patients with advanced/recurrent colorectal cancer (CRC). METHODS: Correlations between TS and DPD and primary and metastatic lesions in recurrent CRC were analyzed. Univariate and multivariate analyses of TS and DPD in combination with response rate (RR), progression-free survival (PFS), and overall survival (OS) were performed. RESULTS: A positive correlation between DPD and primary and metastatic lesions; correlations between TS and RR, DPD and RR, and PFS and OS; and significant differences for RR and DPD and TS, PFS and DPD, and OS and DPD were obtained. CONCLUSION: Nucleic acid metabolizing enzymes in primary lesions can be used to predict mFOLFOX6 efficacy in patients with recurrent CRC.

Predictors of Lateral Pelvic Lymph Node Metastasis in Advanced Low Rectal Cancer Treated With Neoadjuvant Chemotherapy.

BACKGROUND/AIM: This retrospective study used magnetic resonance imaging to identify clinicopathological predictors of lateral pelvic lymph node metastasis in patients with advanced low rectal cancer treated with neoadjuvant chemotherapy; only few such studies have been reported. PATIENTS AND METHODS: Sixty-one patients with advanced low rectal cancer who underwent total mesorectal excision and lateral pelvic lymph node dissection after neoadjuvant chemotherapy between April 2013 and December 2019 were included in this study. Univariate and multivariate analyses were used to analyze the relationship between lateral pelvic lymph node metastasis and clinicopathological factors, such as lateral pelvic lymph node size, measured before and after neoadjuvant chemotherapy using magnetic resonance imaging. RESULTS: The short-axis diameter of lateral pelvic lymph nodes before neoadjuvant chemotherapy (p=0.003, odds ratio: 2.898, 95% confidence interval=1.534-9.143) was the only identified independent preoperative predictor. Based on the receiver operating characteristic curve analysis, the cut-off value of the short-axis diameter of lateral pelvic lymph nodes before neoadjuvant chemotherapy was 6.8 mm. The area under the curve was 0.761 (95% confidence interval=0.723-0.932). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 77.8%, 72.1%, 53.8%, 88.6%, and 73.8%, respectively. CONCLUSION: The preoperative predictor of lateral pelvic lymph node metastasis in advanced low rectal cancer treated with neoadjuvant chemotherapy was the short-axis diameter of lateral pelvic lymph nodes before neoadjuvant chemotherapy. When lateral pelvic lymph nodes with short-axis diameters above 6.8 mm are present, lateral pelvic lymph node dissection may be necessary.

Validation of Urinary Charged Metabolite Profiles in Colorectal Cancer Using Capillary Electrophoresis-Mass Spectrometry.

This study aimed to validate and reanalyze urinary biomarkers for detecting colorectal cancers (CRCs). We previously conducted urinary metabolomic analyses using capillary electrophoresis-mass spectrometry and found a significant difference in various metabolites, especially polyamines, between patients with CRC and healthy controls (HC). We analyzed additional samples and confirmed consistency between the newly and previously analyzed data. In total, we included 36 HC, 34 adenoma (AD), and 214 CRC samples, which were used for subsequent analyses. Among the 132 quantified metabolites, 16 exhibited consistent differences in both datasets, which included polyamines, etc. Pathway analyses of the integrated data revealed significant differences in many metabolites, such as glutamine, and metabolites of the TCA (tricarboxylic acid cycle) and urea cycles. The discrimination ability of the combination of multiple metabolites among the three groups was evaluated, which yielded higher sensitivity than tumor markers. The Mann-Whitney test was employed to evaluate the prognosis predictivity of the assessed metabolites and the difference between the patients with or without recurrence, which yielded 16 significantly different metabolites. Among these 16 metabolites, 11 presented significant prognosis predictivity. These data indicated the potential of metabolite-based discrimination of patients with CRC and AD from HC and prognosis predictivity of the monitored metabolites.

Postoperative complications, bowel function, and prognosis in restorative proctocolectomy for ulcerative colitis-a single-center observational study of 320 patients.

PURPOSE: To determine the selection criteria, postoperative complications, bowel function, and prognosis of stapled ileal pouch-anal anastomosis (IPAA) and hand-sewn IPAA for ulcerative colitis (UC). METHODS: We defined our surgical indications and strategy, and compared the postoperative complications, bowel function, and prognoses between patients who underwent stapled and hand-sewn IPAA for UC at the Yokohama City University Medical Center between 2004 and 2017. RESULTS: Among 320 patients enrolled, 298 patients underwent stapled IPAA while 22 underwent hand-sewn IPAA. There was no significant difference in the postoperative complications between the two groups. Regarding postoperative bowel function, stapled IPAA caused significantly less soiling (stapled vs hand-sewn: 9.1% vs 41.0%, odds ratio (OR) = 0.14, p < 0.0002), spotting (stapled vs hand-sewn: 23.2% vs 63.6%, OR = 0.17, p < 0.0001), and difficulty in distinguishing feces from flatus (stapled vs hand-sewn: 39.9% vs 63.6%, OR = 0.36, p < 0.026). No postoperative neoplasia was observed at the final follow-up in all patients. CONCLUSION: In this study, there was no clear difference in the postoperative complications between stapled and hand-sewn IPAA, but stapled IPAA resulted in better postoperative bowel function. Postoperative oncogenesis from the residual mucosa is rare. However, future cancer risk remains; thus, careful follow-up is required.

Significance of Radiofrequency Ablation for Unresectable Colorectal Cancer With Liver Metastases.

BACKGROUND/AIM: We aimed to investigate the prognosis of patients who received radiofrequency ablation (RFA) for liver metastases of unresectable colorectal cancer (CRC). PATIENTS AND METHODS: We retrospectively compared 147 patients treated for CRC liver metastases, who underwent RFA (n=26), resection (n=92), and chemotherapy (n=29) between 2001 and 2021. RESULTS: RFA and chemotherapy were performed for unresectable or non-operable cases, and resection was performed for suitable cases. The median overall survival (OS) was 44.9, 49.5, and 11.6 months for patients who underwent RFA, resection, and chemotherapy, respectively. RFA led to a significantly shorter OS compared to resection (p=0.027) but to a longer OS compared to chemotherapy (p=0.003). The 5-year survival rates were 34.6% and 42.4% for patients who underwent RFA and resection, respectively (p=0.508). CONCLUSION: RFA has the potential to achieve long-term survival or radical cure, even for unresectable or non-operable cases of CRC with liver metastasis.

A Novel Predictive Model for Anastomotic Leakage in Colorectal Cancer Using Auto-artificial Intelligence.

AIM: Anastomotic leakage (AL) in left-sided colorectal cancer is a serious complication, with an incidence rate of 6-18%. We developed a novel predictive model for AL in colorectal surgery with double-stapling technique (DST) anastomosis using auto-artificial intelligence (AI). PATIENTS AND METHODS: A total of 256 patients who underwent curative surgery for left-sided colorectal cancer between 2017 and 2021 were included. In addition to conventional clinicopathological factors, we included the type of circular stapler using DST, conventional double-row circular stapler (DCS) or EEA™ circular stapler with Tri-Staple™ technology, 28 mm Medium/Thick (Covidien, New Haven, CT, USA) which had triple-row circular stapler (TCS) as a covariate. Auto-AI software Prediction One (Sony Network Communications Inc.) was used to predict AL with 5-fold cross validation. Predictive accuracy was assessed using the area under the receiver operating characteristic curve. Prediction One also evaluated the 'importance of variables' (IOV) using a method based on permutation feature importance. RESULTS: The area under the curve of the AI model was 0.766. The type of circular stapler used was the most influential factor contributing to AL (IOV=0.551). CONCLUSION: This auto-AI predictive model demonstrated an improvement in accuracy compared to the conventional model. It was suggested that use of a TCS may contribute to a reduction in the AL rate.

Sporadic intra-abdominal desmoid tumor with a very unusual onset: two case reports.

BACKGROUND: Intra-abdominal desmoid tumors are rare soft tissue tumors that arise mainly in the mesentery and pelvis. Their etiology may include genetic mutations, estrogen-associated changes after childbirth, and mechanical factors such as a history of abdominal surgery. However, there are cases of intra-abdominal desmoid tumors that develop in the absence of such causes. Since they are rare, diagnosis is often difficult based on clinical findings. We encountered two cases of patients with sporadic intra-abdominal desmoid tumors with a very unusual onset and contrasting features. CASE PRESENTATION: The first patient was a 51-year-old asian man who presented with sudden onset of abdominal pain. He was referred to our department because of a giant tumor detected on abdominal ultrasonography. Imaging revealed a 19-cm tumor with internal tumoral hemorrhage; however, no definitive diagnosis was made. Tumor resection was performed for diagnostic and therapeutic purposes. The second patient was a 41-year-old asian man, and right hydronephrosis was detected on abdominal ultrasonography during a periodic medical checkup. We diagnosed invasion of the primary mesenteric tumor into the right ureter using diagnostic imaging and performed ileocecal resection with partial right ureteral resection for a definitive diagnosis and therapeutic purposes. Although the tumors of both patients had developed from the ileal mesentery, the tumors were substantially different from each other based on their imaging findings, macroscopic morphology, and progression pattern. Meanwhile, they showed similar pathological characteristics. Both consisted of bundles of collagen fibrils of spindle-shaped fibroblasts with low cell atypia. Moreover, they were diagnosed as desmoid tumors using positive immunohistochemical staining for ß-catenin. CONCLUSIONS: Neither patient had susceptibility factors for desmoid tumors, and to our knowledge, there have been very few reports to date of intra-abdominal desmoid tumors that were diagnosed because of acute abdominal pain caused by tumoral hemorrhage or asymptomatic obstructive uropathy. Furthermore, it is clinically interesting that the two patients showed contrasting progression patterns and imaging findings. Intra-abdominal desmoid tumors are rare and may present with various symptoms and findings similar to those observed in our patients. Diagnosis therefore requires experience and knowledge that is not bound by preconceptions.

Neutrophil-to-lymphocyte Ratio as a Prognostic Factor for Colon Cancer in Elderly Patients: A Propensity Score Analysis.

AIM: This study aimed to evaluate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in elderly patients with Stage I-III colon cancer for long-term oncologic outcomes. PATIENTS AND METHODS: We retrospectively reviewed 175 patients aged >75 years who underwent radical surgery for Stage I-III colon cancer between 2000 and 2015 at our institute. Overall survival (OS), cancer-specific survival (CSS), and relapse-free survival (RFS) were evaluated according to NLR values using propensity score analysis. Patients were allocated to the higher NLR (H-NLR) or the lower NLR (L-NLR) group with a cut-off value of 2.3, based on receiver operating characteristic curve. RESULTS: Before case matching, there were significant differences between the two groups for CSS (p=0.023) and RFS (p<0.001), but not for OS (p=0.069). Similar results were obtained after case matching, with significant differences observed for CSS (p=0.003) and RFS (p=0.027), but not for OS (p=0.145). CONCLUSION: NLR may be a prognostic factor in elderly patients with colon cancer.

A Novel Prediction Model for Colon Cancer Recurrence Using Auto-artificial Intelligence.

BACKGROUND/AIM: We aimed to develop a novel recurrence prediction model for stage II-III colon cancer using simple auto-artificial intelligence (AI) with improved accuracy compared to conventional statistical models. PATIENTS AND METHODS: A total of 787 patients who had undergone curative surgery for stage II-III colon cancer between 2000 and 2018 were included. Binomial logistic regression analysis was used to calculate the effect of variables on recurrence. The auto-AI software 'Prediction One' (Sony Network Communications Inc.) was used to predict recurrence with the same dataset used for the conventional statical model. Predictive accuracy was assessed by the area under the receiver operating characteristic curve (AUC). RESULTS: The AUC of the multivariate model was 0.719 (95%CI=0.655-0.784), whereas that of the AI model was 0.815, showing a significant improvement. CONCLUSION: This auto-AI prediction model demonstrates improved accuracy compared to the conventional model. It could be constructed by clinical surgeons who are not familiar with AI.

Laparoscopic middle colic artery-preserved right hemicolectomy with true D3 lymph node dissection for right-sided colon cancer: modified complete mesocolic excision.

BACKGROUND: Complete mesocolic excision (CME) has been demonstrated to be a useful surgical procedure for advanced colon cancer. We previously reported on laparoscopic (Lap) CME with true central vascular ligation (CVL) for advanced right-sided colon cancer. Lap CME with true CVL is highly plausible from the perspective of surgical oncology. However, true CVL of the middle colic artery (MCA) may require extensive resection of the transverse colon. The Japanese Classification of Colorectal Cancer defines D3 as main lymph node dissection around the superior mesenteric artery (SMA), and true CVL is not listed as a required condition. Our institution has been performing a Lap procedure (Lap D3/modified CME) that consists of the dissection of main lymph nodes around the root of the MCA (#223LNs) while preserving the left branch of the MCA. Two videos of a Lap D3/modified CME are presented, and the short-term outcome is reported. METHODS: Lap D3/modified CME was defined as Lap ligation surgery at the root of the right branch of the MCA that preserves the MCA with #223LNs on the resection side. The present study retrospectively examined 11 cases of Lap D3/modified CME performed at the Tokyo Medical University Hospital between 2015 and 2020. When the SMA is difficult to visualize in Type V/A cases, the SMV is pulled using some silicone string, and the surrounding lymph nodes are dissected while visualizing the SMA. RESULTS: The median operating time was 289 min, and the median blood loss was 57 ml. The median total number of dissected lymph nodes was 38, and the median number of dissected #223LNs was three. No metastasis was found in the dissected #223LNs. CONCLUSION: Although this surgery can be performed safely, we believe that this surgery needs to be performed for suitable cases by a highly experienced and skilled surgical team.