Chimeric efferocytic receptors improve apoptotic cell clearance and alleviate inflammation.

Our bodies turn over billions of cells daily via apoptosis and are in turn cleared by phagocytes via the process of "efferocytosis." Defects in efferocytosis are now linked to various inflammatory diseases. Here, we designed a strategy to boost efferocytosis, denoted "chimeric receptor for efferocytosis" (CHEF). We fused a specific signaling domain within the cytoplasmic adapter protein ELMO1 to the extracellular phosphatidylserine recognition domains of the efferocytic receptors BAI1 or TIM4, generating BELMO and TELMO, respectively. CHEF-expressing phagocytes display a striking increase in efferocytosis. In mouse models of inflammation, BELMO expression attenuates colitis, hepatotoxicity, and nephrotoxicity. In mechanistic studies, BELMO increases ER-resident enzymes and chaperones to overcome protein-folding-associated toxicity, which was further validated in a model of ER-stress-induced renal ischemia-reperfusion injury. Finally, TELMO introduction after onset of kidney injury significantly reduced fibrosis. Collectively, these data advance a concept of chimeric efferocytic receptors to boost efferocytosis and dampen inflammation.

Risk factors for lateral lymph node metastasis based on the molecular profiling of rectal cancer.

AIM: The association between molecular profiles and lateral lymph node metastasis (LLNM) in patients with rectal cancer remains unclear. Therefore, this study aimed to identify the molecular profiles of rectal cancer associated with LLNM. METHOD: We retrospectively examined patients who underwent rectal cancer surgery with lateral lymph node dissection without preoperative treatment and whose surgically resected specimens were evaluated using multiomics-based analyses from 2014 to 2019. We compared the clinical characteristics and molecular profiles of patients with pathological LLNM (pLLNM+) with those of patients without (pLLNM-) and identified risk factors for LLNM. RESULTS: We evaluated a total of 123 patients: 18 with and 105 without pLLNM. The accumulation of mutations in genes key for the development of colorectal cancer were similar between the groups, as was the tumour mutation burden. The distribution of consensus molecular subtypes (CMS) was significantly different between the groups (p = 0.0497). The pLLNM+ patients had a higher prevalance of CMS4 than the pLLNM- patients (77.8% vs. 51.4%). According to the multivariate analysis, the independent risk factors for LLNM were a short-axis diameter of the lateral lymph node of ≥6.0 mm and CMS4; furthermore, the presence of either or both had a sensitivity of 100% for the diagnosis of LLNM. CONCLUSION: Lateral lymph node size and CMS4 are useful predictors of LLNM. The combination of CMS classification and size criteria was remarkably sensitive for the diagnosis of LLNM.

Risk factors for stoma prolapse after laparoscopic loop colostomy.

BACKGROUND: Stoma prolapse (SP) is a common stoma-related complication, particularly in loop colostomies. This study aimed to investigate potential risk factors for SP development after laparoscopic loop colostomy. METHODS: In total, data from 140 patients who underwent laparoscopic loop colostomy were analyzed between September 2016 and March 2022. Risk factors for SP were investigated retrospectively. RESULTS: The median follow-up duration after colostomy was 12.5 months, and SP occurred in 33 (23.6%) patients. Multivariate analysis showed that being overweight (body mass index ≥ 25; odds ratio [OR], 8.69; 95% confidential interval [CI], 1.61-46.72; p = 0.012) and having a thin rectus abdominis penetration of the stoma (< 8.9 mm; OR, 8.22; 95% CI, 2.50-27.05; p < 0.001) were independent risk factors for SP. Other patient characteristics and surgical factors associated with stoma construction were unrelated to SP development. CONCLUSIONS: Being overweight and the route penetrating the thinner rectus abdominis during stoma construction was associated with a significantly higher incidence of SP after laparoscopic loop colostomy. Selecting a construction site that penetrates the thicker rectus abdominis muscle may be crucial for preventing SP.

Vagus nerve stimulation activates two distinct neuroimmune circuits converging in the spleen to protect mice from kidney injury.

Acute kidney injury is highly prevalent and associated with high morbidity and mortality, and there are no approved drugs for its prevention and treatment. Vagus nerve stimulation (VNS) alleviates inflammatory diseases including kidney disease; however, neural circuits involved in VNS-induced tissue protection remain poorly understood. The vagus nerve, a heterogeneous group of neural fibers, innervates numerous organs. VNS broadly stimulates these fibers without specificity. We used optogenetics to selectively stimulate vagus efferent or afferent fibers. Anterograde efferent fiber stimulation or anterograde (centripetal) sensory afferent fiber stimulation both conferred kidney protection from ischemia-reperfusion injury. We identified the C1 neurons-sympathetic nervous system-splenic nerve-spleen-kidney axis as the downstream pathway of vagus afferent fiber stimulation. Our study provides a map of the neural circuits important for kidney protection induced by VNS, which is critical for the safe and effective clinical application of VNS for protection from acute kidney injury.

Short-term and long-term outcomes after robotic radical surgery for rectal gastrointestinal stromal tumor.

BACKGROUND: The optimal approach for ensuring both complete resection and preservation of anal function in rectal gastrointestinal stromal tumor (GIST) remains unknown. The aim of this study was to clarify short-term and long-term outcomes after robotic radical surgery for rectal GIST. METHODS: A total of 13 patients who underwent robotic radical surgery for rectal GIST between December 2011 and April 2022 were included. All robotic procedures were performed using a systematic approach. A supplemental video of robotic radical surgery for rectal GIST is attached. The short-term outcome was the incidence of postoperative complications during the first 30 days after surgery. Surgical outcomes were retrieved from a prospective database. Long-term outcomes, including overall survival and recurrence-free survival, were determined in all patients. RESULTS: Median distance from the tumor to the anal verge was 4.0 cm. Surgical margins were negative in all patients. Two patients underwent neoadjuvant imatinib therapy. All patients underwent sphincter-preserving surgery. None underwent conversion to open or laparoscopic surgery. The incidence of postoperative Clavien-Dindo grade II and grade ≥ III complications was 7.7% and 0%, respectively. The median postoperative hospital stay was 7 days. Twelve patients (92.3%) underwent stoma closure within 5 months of the initial surgery. Median follow-up time was 76 months. The 5-year overall survival and recurrence-free survival rates were both 100%. None of the patients had recurrence. CONCLUSION: Short-term and long-term outcomes after radical robotic surgery for rectal GIST were favorable. Robotic surgery might be a useful surgical approach for rectal GIST.

Feasibility of two laparoscopic surgeries for colon cancer performed by the same surgeon on a single day.

BACKGROUND: Although the proportion of laparoscopic colectomies (LCs) for colon cancer is increasing, the feasibility of the same surgeon performing two LCs on a single day remains unknown. This study was conducted to clarify the feasibility of this practice by evaluating short-term and long-term outcomes. METHODS: This retrospective analysis enrolled patients with pathological stage I-III colon cancer who underwent LC at the Shizuoka Cancer Center between 2010 and 2020. Patients were divided into two groups based on the timing of the surgery for the surgeon. The first group (n = 1485) comprised patients who underwent LC as the first surgery of the day for the surgeon. The second group (n = 163) comprised patients who underwent LC as the second LC of the day for the surgeon. Propensity score matching was performed to balance the baseline characteristics of the first and second groups. The short-term and long-term outcomes of the two groups were compared. RESULTS: After propensity score matching, there were no significant differences in the incidence of postoperative complications of Clavien-Dindo classification grade II or higher between the first (10.4%, 17/163) and second groups (5.5%, 9/163). There were no significant differences in other perioperative outcomes, including operative time, intraoperative blood loss, and incidence of conversion to open surgery, between the two groups. Regarding long-term outcomes, there were no significant differences in overall survival or relapse-free survival between the two groups both in the full cohort and in the propensity score-matched cohort. In the propensity score-matched cohort, 5-year overall survival was 92.7% in the first group and 94.4% in the second group; 5-year relapse-free survival was 87.1% and 90.3%, respectively. CONCLUSION: Our results suggest that the same surgeon performing two LCs for colon cancer on a single day is feasible in terms of short-term and long-term outcomes.

Risk factors for and longitudinal course of male sexual dysfunction after robotic rectal cancer surgery.

AIM: The aim of this work was to investigate the risk factors associated with the incidence of sexual dysfunction in patients who underwent robot-assisted surgery with several treatment options, such as neoadjuvant chemoradiotherapy and lateral lymph node dissection, and clarify the longitudinal course of erectile function in risk groups. METHOD: A total of 203 male patients who underwent robot-assisted total mesorectal excision for rectal cancer between 2013 and 2019 were included. The risk factors for erectile and ejaculatory dysfunction as well as the longitudinal course of erectile function were retrospectively investigated in all cohorts and several risk groups, including those who underwent neoadjuvant chemoradiotherapy, lateral lymph node dissection and adjuvant chemotherapy. Erectile dysfunction was assessed using the International Index of Erectile Function and ejaculatory dysfunction was assessed using original questions. The survey was performed preoperatively and at 3, 6 and 12 months postoperatively. RESULTS: Erectile and ejaculatory dysfunction occurred in 46.8% and 15.7% of the patients, respectively. Multivariate analysis showed that neoadjuvant chemoradiotherapy was an independent risk factor for erectile dysfunction. Erectile function recovered longitudinally to the preoperative level overall, as well as in lateral lymph node dissection and postoperative adjuvant chemotherapy subgroups; however, recovery was poor in the neoadjuvant chemoradiotherapy group, even at 12 months postoperatively. CONCLUSION: Neoadjuvant chemoradiotherapy was found to be a risk factor for erectile dysfunction after robot-assisted surgery for rectal cancer. Erectile function recovered postoperatively in patients undergoing lateral lymph node dissection; however, those receiving neoadjuvant chemoradiotherapy showed poor recovery, even at 12 months postoperatively.

The impact of mesorectal fat area on recurrence following total mesorectal excision for lower rectal cancer.

BACKGROUND: The mesorectal fat area (MFA) at the tip of the ischial spines on magnetic resonance imaging has been used to characterize mesorectal morphology. Recent studies reported that a larger MFA correlated with difficulties in rectal cancer surgery. However, the relationship between MFA and rectal cancer prognosis remains unclear. This study evaluated the impact of MFA on recurrence following robotic total mesorectal excision (TME) for rectal cancer. METHODS: Patients who underwent robotic TME for lower rectal cancer from December 2011 to December 2016 were enrolled. Cox regression analysis was performed to determine variables associated with relapse-free survival (RFS). Patients were divided into groups based on MFA, and RFS was compared. RESULTS: Of 230 patients, 173 (75.3%) were male. The median age was 63 years, and median MFA was 19.7 cm2. In multivariate analysis, smaller MFA (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.88-0.97; p < 0.01), p/yp stage II (HR, 3.81; 95% CI, 1.40-10.35; p < 0.01), and p/yp stage III (HR, 5.35; 95% CI, 1.88-15.27; p < 0.01) were independently associated with worse RFS. Sex, body mass index, and visceral fat area were not correlated with RFS. In the median follow-up period of 60.8 months, patients with MFA < 19.7 cm2 had a significantly lower 5-year RFS rate (72.7%) than those with MFA ≥ 19.7 cm2 (85.0%). CONCLUSIONS: Smaller MFA was associated with worse RFS in patients undergoing robotic TME for lower rectal cancer. MFA is considered to be a prognostic factor in rectal cancer.

Incidence and clinical significance of 491 known fusion genes in a large cohort of Japanese patients with colorectal cancer.

BACKGROUND: The clinical significance of fusion genes in colorectal cancer remains unclear. The purpose of this study was to determine the incidence of fusion genes in colorectal cancer and explore their clinical significance by screening for common fusion genes in a large Japanese cohort. METHODS: This study involved 1588 patients. The incidence of 491 fusion genes was examined using a designed fusion panel. In addition, the patients were classified into two groups (RSPO fusion-positive or -negative) according to the presence of RSPO fusions, and the clinicopathological and genetic characteristics of both groups were compared. Long-term outcomes were analyzed in patients without distant metastases. RESULTS: Fusion genes were detected in 2% (31/1588) of colorectal cancers. The incidence of RSPO fusions (such as PTPRK-RSPO3 and EIF3E-RSPO2) was 1.5% (24/1588), making them the most common fusions, whereas the incidence of other fusion genes was extremely low. The distribution of consensus molecular subtypes and frequency of APC mutations were significantly different between the RSPO fusion-positive and -negative groups. The 3-year cumulative incidence rate of recurrence was higher in the RSPO fusion-positive group than in the RSPO fusion-negative group (positive, 31.2% vs. negative, 13.5%, hazard ratio = 2.357; p = 0.040). CONCLUSION: Broad screening for fusion genes showed that RSPO fusions were the most common in colorectal cancer, with an incidence of 1.5%. RSPO fusions may be clinically significant in identifying patients at a high risk of recurrence who would be responsive to specific treatments.

Long-term outcomes of upfront robotic rectal cancer surgery: a single-center, retrospective cohort study in Japan.

PURPOSE: The purpose of this study was to evaluate the long-term outcomes of robotic rectal cancer surgery and to examine the risk factors for recurrence. METHODS: In a high-volume center in Japan, we retrospectively enrolled patients with pStage I-III rectal cancer within 15 cm of the anal verge who underwent robotic surgery from 2011 to 2017. Almost all patients underwent upfront surgery, and lateral lymph-node dissection (LLND) was performed for patients with locally advanced lower rectal cancer. We evaluated the 5-year overall survival (OS), relapse-free survival (RFS), and cumulative local recurrence (LR) rates and examined the risk factors for the RFS. RESULTS: We evaluated 488 patients who underwent robotic rectal cancer surgery, including 5.1% who underwent preoperative chemoradiotherapy to obtain clear resection margins and 33.6% who underwent LLND. There were 203, 87, and 198 patients with pStage I, II, and III, respectively, and the positive resection margin rate was 1.0%. The 5-year OS, RFS, and LR rates were 95.5%, 81.7%, and 2.2%, respectively. The independent risk factors for the RFS were the presence of venous invasion, extramural tumor deposits without lymph-node structure, and pT ≥ 3. CONCLUSION: This study demonstrated the favorable long-term outcomes of robotic rectal cancer surgery.

Lymph node metastasis in T1 colorectal cancer with the only high-risk histology of submucosal invasion depth ≥ 1000 µm.

PURPOSE: The number of patients undergoing additional surgery after endoscopic resection (ER) for T1 colorectal cancer (CRC) is increasing. Regarding high-risk histology of lymph node metastasis (LNM) in T1 CRC, a submucosal invasion depth ≥ 1000 µm (T1b) alone may be related to a low incidence of LNM. This study was conducted to clarify the incidence of LNM and to identify factors associated with LNM in T1 CRC with high-risk histology characterized only by T1b. METHODS: We retrospectively investigated patients with pathological T1b CRC who underwent colorectal resection between 2010 and 2020. Patients were divided into two groups with high-risk histology: those in whom the only high-risk feature was T1b (low-risk T1b group, n = 263), and those with T1b as well as lymphovascular invasion, tumor budding, or poorly differentiated or mucinous adenocarcinoma (high-risk T1b group, n = 289). The incidences of LNM and recurrence were compared. Multivariate analysis was performed to identify factors associated with LNM in the low-risk T1b group. RESULTS: The incidences of LNM were 3.8% and 21.6% in the Low- and High-risk T1b groups, respectively (p < 0.01), while the 5-year recurrence rates in the two groups were 0.6% and 3.4%, respectively (p = 0.10). Multivariate analysis revealed that only a predominant histological type of moderately differentiated adenocarcinoma (p = 0.04) was independently associated with LNM in the low-risk T1b group. CONCLUSION: When considering the omission of additional surgery after ER in cases of T1 CRC whose only high-risk histological feature is T1b, attention should be paid to the predominant histological type.

Robotic surgery for clinical T4 rectal cancer: short- and long-term outcomes.

BACKGROUND: The optimal surgical approach for clinical T4 (cT4) rectal cancer is unknown. This study was conducted to clarify short- and long-term outcomes of robotic surgery for cT4 rectal cancer. METHODS: In our retrospective cohort study, we enrolled patients who underwent robotic surgery for cT4 rectal cancer within 15 cm from the anal verge between 2011 and 2018. The short- and long-term outcomes were evaluated. RESULTS: Of a total of 122 eligible patients, 70 (57%) had cT4a tumors and 52 (43%) had cT4b tumors. Thirty-five patients (29%) had distant metastasis and 21 (17%) underwent preoperative chemoradiotherapy. Thirty-four patients (28%) underwent combined resection of adjacent organs and 43 (35%) underwent lateral lymph node dissection. The median operative time was 288 min and the median blood loss was 11 ml. No patients required conversion to open surgery. The incidences of postoperative complications of grades II, III, and IV or more according to the Clavien-Dindo classification were 17.2%, 3.5%, and 0%, respectively. Seventy-three patients (60%) had pathological T4 tumors, and the incidence of positive resection margins was 4.9%. The median follow-up time was 42.9 months. The 3-year overall survival, disease-free survival, and cumulative local recurrence rates were 87.5%, 70.4%, and 4.0%, respectively. CONCLUSIONS: The short- and long-term outcomes of robotic surgery for cT4 rectal cancer were favorable. Robotic surgery is considered to be a useful approach for cT4 rectal cancer.

Clinical outcomes following colorectal resection of colorectal cancer with simultaneous hepatic and pulmonary metastases at the time of diagnosis.

PURPOSE: There are no established treatment strategies for patients with hepatic and pulmonary metastases at the time of primary colorectal cancer (CRC) diagnosis. This study assessed patients undergoing complete resection of primary CRC and hepatic and pulmonary metastases, to evaluate long-term outcomes and clarify clinicopathological factors associated with failure of complete resection. METHODS: This retrospective analysis enrolled patients at Shizuoka Cancer Center between 2002 and 2018 who underwent colorectal resection with curative intent for primary CRC with hepatic and pulmonary metastases. The curative resection (CR) group comprised patients who underwent complete resection of the primary tumor and metastatic lesions, and the non-curative resection (Non-CR) group consisted of those in whom resection of the metastatic lesions was not performed. Univariate and multivariate analyses were conducted to determine clinicopathological factors associated with non-curative resection. RESULTS: Of 26 total patients, the CR and Non-CR groups consisted of 14 (54%) and 12 patients (46%), respectively. In the CR group, the 3-year overall and relapse-free survival rates were 92.9% and 28.6%, respectively. Multivariate analysis showed that pathological stage T4 (odds ratio 8.58, 95% confidence interval 1.13-65.20, p = 0.04) was independently associated with non-curative resection. CONCLUSION: The percentage of patients undergoing complete resection of primary CRC and metastatic lesions was 56%, and the 3-year OS rate was 92.9%. Resection of primary CRC and metastatic lesions was considered to be appropriate in this population, and pathological stage T4 tumor was associated with incomplete resection of metastatic tumors.

Long-term outcomes of D2 vs. D3 lymph node dissection for cT2N0M0 colorectal cancer: a multi­institutional retrospective analysis.

BACKGROUND: According to Japanese guidelines, D2 or D3 lymph node dissection (LND) is indicated for cT2N0M0 colorectal cancer (CRC). In this study, we retrospectively compared the long-term outcomes between D2 and D3 LND among patients with cT2N0M0 CRC. METHODS: Our sample included 515 patients from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database, who underwent surgical resection for cT2N0M0 CRC between January 2009 and December 2012, 195 (37.9%) of whom underwent D2 LND and 320 (62.1%) D3 LND. The D2 and D3 groups were retrospectively compared in terms of long-term outcomes including overall survival (OS) and relapse-free survival (RFS). The prognostic factors for these outcomes were also evaluated. RESULTS: The D2 group had significantly older patients and higher proportion of men than the D3 group. The rates of OS (5-year OS; 94.8% in the D3 group vs. 93.4% in the D2 group, p = 0.38) and RFS (5-year RFS; 89.3% in the D3 group vs. 89.1% in the D2 group, p = 0.91) were comparable for both groups. On multivariate analysis, age ≥ 80 years was significantly associated with poor OS. The extent of LND was not associated with either OS or RFS. Long-term outcomes were similar between the two groups, independent of tumor location. CONCLUSION: The long-term outcomes did not differ between the D2 and D3 groups and the extent of LND was not associated with prognosis for cT2N0M0 CRC. Therefore, D2 LND may be sufficient for cT2N0N0 CRC treatment.

Neoadjuvant chemoradiotherapy for borderline resectable low rectal cancer: short- and long-term outcomes at a single Japanese center.

PURPOSE: Rectal cancers pose a threat to the mesorectal fascia or invade neighboring structures or organs. Some tumors are potentially resectable but are likely to be positive at the resection margin for cancer involvement and are thus recognized as "borderline resectable (BR)" tumors. This study aimed to clarify the short- and long-term outcomes of neoadjuvant chemoradiotherapy (nCRT) for BR low rectal cancer at a single Japanese center. METHODS: Data of 55 patients, who received nCRT followed by BR low rectal cancer surgery between April 2010 and December 2019, were evaluated for the short-term outcomes. The oncological outcomes of 42 patients who underwent surgery between April 2010 and December 2018 were evaluated. RESULTS: Thirty-six (65.5%) patients had cT4 tumors, and 53 (96.4%) patients had a clinical-stage III or IV. Lateral lymph node dissection was performed in 42 (76.4%) patients. The incidence of severe post-operative complications (Clavien-Dindo grade ≥ III) was 18.2%. Fifty-two (94.5%) patients had a pathological negative resection margin. The 3-year overall survival rate, disease-free survival rate, and cumulative incidence of local recurrence were 100%, 70.3%, and 5.3%, respectively. CONCLUSION: The short- and long-term outcomes of nCRT for BR low rectal cancer were acceptable. In particular, reasonable local control was achieved.

The Eastern Cooperative Oncology Group Performance Status as a prognostic factor of stage I-III colorectal cancer surgery for elderly patients: a multi-institutional retrospective analysis.

PURPOSES: The relationship between the general condition and long-term prognosis in elderly patients with colorectal cancer (CRC) undergoing curative surgery remains unclear. This study investigated the risk factors for poor long-term outcomes in elderly patients with CRC. METHODS: Data of pStage I to III patients with CRC ≥ 80 years old who underwent curative surgery were collected from a multi-institutional database of the Japanese study group for postoperative follow-up of CRC. We retrospectively investigated the poor prognostic factors for the overall survival (OS) and relapse-free survival (RFS). RESULTS: A total of 473 patients with a median age of 83 years were investigated (315, 121, 34, and 3 with an Eastern Cooperative Oncology Group Performance Status [ECOG-PS] 0, 1, 2, and 3, respectively). Multivariate Cox regression analysis showed that ECOG-PS ≥ 2 and positive lymph node metastasis were independently associated with a poor OS (both p < 0.01). Positive lymph node metastasis (p < 0.01) and tumor depth (T3 or T4) (p = 0.02) were independently associated with a poor RFS. In Stages I and II, but not Stage III patients, the OS was significantly worse in those with ECOG-PS ≥ 2 than in those with ECOG-PS ≤ 1. CONCLUSION: Preoperative ECOG-PS was a significant prognostic factor for elderly patients with CRC after curative surgery.

Advantages of robotic abdominoperineal resection compared with laparoscopic surgery: a single-center retrospective study.

PURPOSE: Although robotic surgery for rectal cancer can overcome the shortcomings of laparoscopic surgery, studies focusing on abdominoperineal resection are limited. The aim of this study was to compare the operative outcomes between robotic and laparoscopic abdominoperineal resection. METHODS: This retrospective cohort study was conducted from April 2010 to March 2020. Patients with rectal cancer who underwent robotic or laparoscopic abdominoperineal resection without lateral lymph node dissection were enrolled. The perioperative and oncological outcomes were compared. RESULTS: We evaluated 33 and 20 patients in the robotic and laparoscopic groups, respectively. The median operative time and blood loss were comparable between the two groups. No significant differences in the overall complication rates were noted, whereas the rates of urinary dysfunction (3% vs. 26%, p = 0.02) and perineal wound infection (9% vs. 35%, p = 0.03) in the robotic group were significantly lower in comparison to the laparoscopic group. The median postoperative hospital stay was significantly shorter in the robotic group (8 days vs. 11 days, p < 0.01). The positive resection margin rates were comparable between the two groups. CONCLUSION: Robotic abdominoperineal resection demonstrated better short-term outcomes than laparoscopic surgery, suggesting that it could be a useful approach.

Efficacy of a robotic stapler on symptomatic anastomotic leakage in robotic low anterior resection for rectal cancer.

PURPOSE: Clinical evidence demonstrating risk factors for anastomotic leakage including robotic staplers has remained limited, even though the use of robotic surgery has increased substantially. The purpose of this study was to evaluate the effects of robotic staplers on symptomatic anastomotic leakage in robotic low anterior resection for rectal cancer. METHODS: A total of 427 consecutive patients with primary rectal cancer who underwent robotic low anterior resection without diverting stoma were investigated retrospectively. Symptomatic anastomotic leakage was defined as anastomotic leakage of Clavien-Dindo Grade ≥ II. We compared the symptomatic anastomotic leakage rates between manual and robotic staplers using propensity score matching and investigated the risk factors for symptomatic anastomotic leakage. RESULTS: After propensity score matching, 168 pairs of manual and robotic stapler cases were selected. The symptomatic anastomotic leakage rate was significantly higher for manual staplers (6.5%) than for robotic staplers (1.2%, p = 0.02). In a multivariate analysis, the use of a manual stapler (p = 0.04, OR 4.86, 95% CI 1.08-21.8) and anastomosis < 4 cm from the anal verge (p < 0.01, OR 4.36, 95% CI 1.48-12.9) were identified as independent risk factors for symptomatic anastomotic leakage. CONCLUSIONS: Robotic stapler use was associated with a significantly decreased rate of anastomotic leakage in robotic low anterior resection without diverting stoma for rectal cancer.

Short- and Long-Term Outcomes of Robotic Surgery for Rectal Neuroendocrine Tumor.

Background. The optimal radical surgical approach for rectal neuroendocrine tumor (NET) is unknown. Methods. This study evaluated the short- and long-term outcomes of 27 patients who underwent robotic radical surgery for rectal NET between 2011 and 2019. Results. The median distance from the lower border of the tumor to the anal verge was 5.0 cm. The median tumor size was 9.5 mm. Six patients (22%) had lymph node metastasis. The incidences of postoperative complications of grade II and grade III or more according to the Clavien-Dindo classification were 11% and 0%, respectively. All patients underwent sphincter-preserving surgery, and no patients required conversion to open surgery. The median follow-up time was 48.9 months, and both the 3-year overall survival and relapse-free survival rates were 100%. Conclusions. Short- and long-term outcomes of robotic surgery for rectal NET tumor were favorable. Robotic surgery may be a useful surgical approach for rectal NET.

Minimally invasive surgery for colorectal cancer with persistent descending mesocolon: radiological findings and short-term outcomes.

BACKGROUND: Persistent descending mesocolon (PDM) is typically asymptomatic. However, features such as adhesion and variations in vessel anatomy could affect the surgical techniques for colorectal cancer (CRC). This study aimed to investigate the frequency and radiological features of PDM. Short-term outcomes after conventional laparoscopic surgery (CLS) for CRC with PDM were also investigated to assess the feasibility of CLS and identify strategies for minimally invasive surgery (MIS) in CRC with PDM. METHODS: Patients who underwent MIS, including CLS and robot-assisted laparoscopic surgery (RALS), for left-sided CRC between April 2016 and June 2019, were investigated. PDM was defined as the existence of the right border of the descending colon inside the right border of the left kidney based on preoperative computed tomography findings. RESULTS: Radiological findings of 837 patients were examined, and PDM was found in 19 (2.3%) patients. Radiality of the inferior mesenteric artery (IMA) was found in 5 of 19 (26.3%) PDM cases, which was significantly higher than that in non-PDM cases. The median lengths between the IMA and inferior mesenteric vein (IMV) and between the IMV and descending colon in PDM cases were 14.8 mm and 17.2 mm, respectively, which were significantly shorter than those in non-PDM cases. Short-term outcomes were evaluated only in CLS cases since the rate of hybrid surgery among RALS cases differed between non-PDM and PDM cases (0% vs. 44.4%), which would affect the surgical outcomes. The short-term outcomes in 447 CLS cases were similar between PDM and non-PDM cases. The frequency of extracorporeal division of the left colic artery (LCA) and IMV was significantly higher in PDM than in non-PDM cases (70.0% vs. 5.7%). CONCLUSIONS: This radiological definition of PDM was feasible. CLS for left-sided CRC with PDM was feasible, and dividing the LCA and IMV extracorporeally would be vital for safe surgery.