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Osteoclast-mediated bioresorption can be an efficient means of incorporating the dissolution of biomaterials in the bone remodeling process. Because of the compositionally and structurally close resemblance of biomaterials with the natural mineral phases of the bone matrix, synthetic carbonate-substituted apatite (CA) is considered as an ideal biomaterial for clinical use. The present study therefore investigated the effects of electrical polarization on the surface characteristics and interactions with human osteoclasts of hydroxyapatite (HA) and CA. Electrical polarization was found to improve the surface wettability of these materials by increasing the surface free energy, and this effect was maintained for 1 month. Analyses of human osteoclast cultures established that CA subjected to a polarization treatment enhanced osteoclast resorption but did not affect the early differentiation phase or the adherent morphology of the osteoclasts as evaluated by staining. These data suggest that the surface characteristics of the CA promoted osteoclast resorption. The results of this work are expected to contribute to the future design of cell-mediated bioresorbable biomaterials capable of resorption by osteoclasts and of serving as a scaffold for bone regeneration.

Background One of the primary treatment for resectable advanced esophageal squamous cell cancer (ESCC) is neoadjuvant chemotherapy (NAC) followed by minimally invasive esophagectomy (MIE). Because the neutrophil-to-lymphocyte ratio (NLR) is a widely reported prognostic factor in several cancers, we investigated whether the preoperative NLR is a biomarker in ESCC patients treated with NAC and MIE. Methods In this study, we investigated 174 ESCC patients who underwent MIE from January 2010 to December 2015, including 121 patients who received NAC. The cutoff value of the NLR was analyzed using the receiver operating characteristic curve. Multivariate analyses were performed to clarify independent prognostic factors for overall survival (OS). Results The cutoff value of the NLR for OS in 121 patients who received NAC was 2.5 ng/ml, and the area under the curve was 0.63026 (p = 0.0127). The 5-year OS rate was 64% in those with an NLR 415 ml were independent poor prognostic factors. Conclusions NLR is a biomarker of prognosis in ESCC patients who undergo MIE after NAC.

Whether surgical device usage in laparoscopic gastrectomy differs with respect to operator’s skill levels is unknown. Further, device usage analysis using artificial intelligence has not been reported to date. Herein, we compared the patterns of surgical device usage during laparoscopic gastrectomy for gastric cancer among surgeons at different skill levels. The data of device usage was acquired from laparoscopic video recordings using an automated surgical-instrument detection system. In total, 100 video recordings of infrapyloric lymphadenectomy and 33 of D2 suprapancreatic lymphadenectomy during laparoscopic gastrectomy for gastric cancer were analyzed in this retrospective study. The system’s accuracy was evaluated by comparing the automatic and the manual usage time. Surgical device usage patterns were compared between qualified and nonqualified surgeons of The Japan Society for Endoscopic Surgery Endoscopic Surgical Skill Qualification System. For every device, the automatic detection time and manual detection time were consistent with each other. In infrapyloric lymphadenectomy, the usage time proportions of dissector forceps and clip applier were higher among nonqualified operators than among qualified operators (dissector, 5.1% vs. 2.3%, P

Background Esophagectomy with lymphadenectomy is the principal treatment for localized esophageal cancer. Conventional minimally invasive esophagectomy (C-MIE) in prone position has spread worldwide as it is less invasive. However, its efficacy remains controversial. Robot-assisted MIE (RAMIE) can have more advantages than C-MIE. Therefore, the current study aimed to validate whether RAMIE is associated with lower incidence of left recurrent laryngeal nerve (RLN) palsy compared with C-MIE in prone position. Patients and Methods In total, 404 patients with esophageal carcinoma underwent MIE (353 C-MIEs and 51 RAMIEs) in prone position at Kobe University between 2010 and 2020. Then, propensity score matching was performed, and results showed that 51 patients should be included in each group. Thereafter, the perioperative outcomes between the two groups were compared. Results The RAMIE group had a significantly longer operative time than the C-MIE group (P < 0.0001). However, the number of lymph nodes resected along the left RLN was similar in both groups. Moreover, the incidence of left RLN palsy was significantly lower in the RAMIE group than in the C-MIE [Clavien-Dindo classification grade II; 0 (0%) versus 32 (9%), P = 0.022 in entire cohort, and 0 (0%) versus 5 (10%), P = 0.022 in matched cohort. Esophagectomy Complications Consensus Group definitions type I; 8 (16%) versus 101 (29%), P = 0.041 in entire cohort and 8 (16%) versus 18 (35%) in matched cohort, P = 0.023]. Conclusion RAMIE is superior to C-MIE in prone position in decreasing the incidence of left RLN palsy.

Ceramics electrets of hydroxyapatite (HAp) have been developed for both power generators and artificial bones. However, the formation mechanisms of the HAp electrets have not yet been completely understood. In particular, it is unclear how the OH− ion-dipoles in HAp lattices contribute to electret performance. Herein, we show that HAp with controlled OH− ion content exhibits excellent performance as an electret. We prepare OH−-defect-controlled HAp samples either by restricted dehydration during thermal process or by valence control through the substitution of Ca2+ with Nd3+. The experimental results prove that the electrets prepared by partially dehydrated HAp and Nd-substituted HAp with a small number of OH− ions showed better performance. Our results suggest that the OH− ion-dipole polarization contributes negatively to the electret performance.

Rectal or anal canal adenocarcinoma with inguinal lymph node metastasis (ILNM) is rare and is associated with poor prognostic outcomes. This study aimed to elucidate the clinical significance of neoadjuvant therapy followed by selective inguinal lymph node dissection and total mesorectal excision for rectal or anal canal adenocarcinoma with clinically suspected ILNM.This study enrolled 15 consecutive patients who underwent neoadjuvant therapy and curative resection for rectal or anal canal adenocarcinoma with clinically suspected ILNM between 2005 and 2019 at a single institution. Inguinal lymph node dissection was selectively performed on the side of suspected metastasis before neoadjuvant therapy. Short- and long-term outcomes were retrospectively reviewed.Out of the15 patients, 11 were treated with neoadjuvant chemoradiation, three with chemotherapy, and one with chemoradiation followed by chemotherapy. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) scans were performed after neoadjuvant therapy in 14 patients. Five patients had negative FDG accumulation in inguinal lymph nodes on FDG-PET scan, and their inguinal lymph nodes were also pathologically negative for metastasis. Of the nine patients who had positive FDG accumulation, four had pathologically positive inguinal lymph nodes. Seven patients (46.7%) had inguinal seroma postoperatively. Five-year-overall survival was 77.5%, and 5-year-relapse-free survival was 64.2%. No patient had a recurrence in the inguinal region.In patients with rectal or anal canal adenocarcinoma associated with clinical ILNM, radical resection with neoadjuvant therapy provides a good long-term survival.

INTRODUCTION Although lateral pelvic lymph node dissection is considered as a treatment option for advanced rectal cancer, it is technically demanding. Recently, the transanal approach for total mesorectal excision has become increasingly used. In this Technical Note, we describe lateral pelvic lymph node dissection using a 2-team method that was assisted by the transanal approach. TECHNIQUE First, the lateral pelvic area was entered from the anal side by dissection between the S4 sacral splanchnic nerve and levator ani muscle. Then, the fatty tissues including the obturator compartment and the distal part of the internal iliac compartment were separated from the inferior and superior vesical vessels and the bladder wall. Next, the fatty tissues were separated from the lateral pelvic wall. The obturator nerve was isolated and preserved, whereas the obturator vessels were resected at their peripheral end. Then, the fatty tissues were dissected from the bottom plane. Finally, the fatty tissues were dissected from the ventral bladder wall and were completely isolated from the obturator nerve in cooperation with the transabdominal team. RESULTS The 2-team method shortened the operative time dramatically and decreased mental and physical burden on the operators during lateral dissection. Assistance with the transanal approach helped with a secure and effective dissection, especially of the most distal parts, such as around the internal pudendal and inferior vesical arteries, because substantial skill is required for the transabdominal approach alone. CONCLUSIONS This procedure is useful for the safe and effective performance of lateral pelvic lymph node dissection for patients with rectal cancer.

Laparoscopic local resection for gastrointestinal stromal tumors (GISTs) near the esophagogastric junction (EGJ) increases the risk of injuring the EGJ. We investigated the safety of laparoscopic local resection for GISTs near the EGJ according to the distance from the EGJ to the tumor edge. We retrospectively evaluated 40 patients who had undergone laparoscopic local resection for GISTs near the EGJ between January 2009 and December 2019. After excluding 1 patient who had undergone right colectomy at the same time, 39 patients were classified according to distance of the GIST from the EGJ in the Near group (0–2.0 cm; n = 16) and the Far group (2.1–5.0 cm; n = 23). We found no marked differences in the operation time, blood loss, length of postoperative hospital stay, or postoperative complication rate in the two groups. Anastomotic leakage occurred with a tumor located on the EGJ. Three tumors recurred in the Near group, and all of them were located on the EGJ. Except for GISTs located on the EGJ, laparoscopic local resection for GISTs near the EGJ can be performed safely with few postoperative complications and a low risk of recurrence.

Background/aim Cancer stem cells (CSCs) contribute to resistance against neoadjuvant chemotherapy (NAC) in esophageal squamous cell carcinoma (ESCC). We conducted a retrospective observational study for the relationship between the expression levels of CSC markers in biopsy specimens prior to 5-fluorouracil plus cisplatin (FP)-NAC and the pathological responses. Patients and methods We included 171 patients with ESCC who underwent the FP-NAC followed by radical resection. Biopsy specimens prior to the FP-NAC were obtained and immunochemically stained for CD44, CD133, and CD24. Results The biopsy specimens of the non-responders had the CD44high/CD24low expression at high levels, which was found as an independent predictor of not only FP-NAC resistance but also poor overall survival by multivariate analyses. Conclusion CD44high/CD24low expression in the biopsy specimens prior to FP-NAC may be a predictor of FP-NAC resistance and poor prognosis of ESCC patients.

Despite the increasing utilization of transanal total mesorectal excision as a promising approach for low rectal cancer, the feasibility and safety of transperineal minimally invasive abdominoperineal resection (tp-APR) remain unclear. In total, 25 patients who underwent tp-APR between April 2017 and May 2020 (tp-APR group) and 27 patients who underwent conventional laparoscopic APR between May 2009 and September 2016 (lap-APR group) for low rectal cancer were enrolled in this retrospective study. Clinical outcomes were compared between the groups before and after propensity score matching. The primary outcome was the incidence of the overall postoperative complications with Clavien–Dindo grade II or above. Standardized technique of tp-APR was also demonstrated. On comparison, operative time, intraoperative blood loss, and overall postoperative complications with Clavien–Dindo grade II or above were significantly less in the tp-APR group both before and after propensity score matching. The rates of urinary disturbance and perineal wound infection were significantly less in the tp-APR group after matching. Further, postoperative hospital stay was significantly shorter in the tp-APR group both before and after matching. However, pathological outcomes did not differ between the groups before and after matching. There has been no local recurrence in the tp-APR group with a median follow-up period of 18 months. Standardized tp-APR for low rectal cancer is feasible and seems superior to conventional laparoscopic APR in terms of short-term outcomes. Further larger-scale studies with a longer follow-up period are required to evaluate oncological outcomes.

Aim The outcomes of gastrectomy for gastric cancer in patients at each severity of chronic kidney disease (CKD) remain unknown. Methods We retrospectively analyzed the outcomes of 560 patients who underwent distal or total gastrectomy for gastric cancer between 2009 and 2018. We classified the patients into four groups based on estimated glomerular filtration rate: stage 1/2 (normal to mild, n = 375), stage 3a (mild to moderate, n = 122), stage 3b (moderate to severe, n = 43), and stage 4/5 (severe to end‐stage, n = 20) CKD. The relationship between CKD stage and the incidence of postoperative morbidity was analyzed. Results CKD was a predictor of overall morbidity independent of age, gender, American Society of Anesthesiologists Performance Status, pulmonary comorbidity, extent of lymphadenectomy, and operation time in a multivariate analysis. The incidences of overall and severe morbidity were significantly increased with CKD progression (both P, Chronic kidney disease (CKD) progression increases the risk of morbidity following gastrectomy in gastric cancer patients. The risk elevates substantially at moderate CKD with an eGFR ≤ 45 ml/min/1.73 m2.

Purpose Rectal or anal canal adenocarcinoma with inguinal lymph node metastasis (ILNM) is rare and is associated with poor prognostic outcomes. This study aimed to elucidate the clinical significance of neoadjuvant therapy followed by selective inguinal lymph node dissection and total mesorectal excision for rectal or anal canal adenocarcinoma with clinically suspected ILNM. Methods This study enrolled 15 consecutive patients who underwent neoadjuvant therapy and curative resection for rectal or anal canal adenocarcinoma with clinically suspected ILNM between 2005 and 2019 at a single institution. Inguinal lymph node dissection was selectively performed on the side of suspected metastasis before neoadjuvant therapy. Short- and long-term outcomes were retrospectively reviewed. Results Out of the15 patients, 11 were treated with neoadjuvant chemoradiation, three with chemotherapy, and one with chemoradiation followed by chemotherapy. Six patients had negative fluorodeoxyglucose (FDG) accumulation in inguinal lymph nodes on preoperative FDG-positron emission tomography (FDG-PET) scan, and their inguinal lymph nodes were also pathologically negative for metastasis. Of the nine patients who had positive FDG accumulation, four had pathologically positive inguinal lymph nodes. Seven patients (46.7%) had inguinal seroma postoperatively. Five-year-overall survival was 77.5%, and 5-year-relapse-free survival was 64.2%. No patient had a recurrence in the inguinal region. Conclusion In patients with rectal or anal canal adenocarcinoma associated with clinical ILNM, radical resection with neoadjuvant therapy provides a good long-term survival.

Nonoperative management (NOM) has been widely accepted as one of the standard treatments for patients with acute appendicitis. However, predictive factors for the failure of NOM have not been thoroughly investigated. A total of 196 patients with acute appendicitis underwent NOM between April 2014 and December 2020. Of these 196 patients, 24 patients failed NOM and required emergency surgery (failure group: n = 24), while the other 172 patients were successfully treated with NOM (success group: n = 172). These two groups were compared, and the predictive factors for the failure of NOM were investigated. The number of patients who had a previous history of stroke was significantly increased in the failure group (12.5% vs. 2.9%, p = 0.026). Incarceration of an appendicolith on CT images was significantly associated with the failure group (20.8% vs. 1.7%, p

Situs inversus totalis (SIT) is a rare condition in which the internal organ's position is a mirror image of normal anatomy. Although several investigators reported laparoscopic surgery for colorectal cancer in patients with SIT, it is considered difficult even for an experienced surgeon because of the mirror position. We show a case report of laparoscopic sigmoidectomy with the splenic flexure mobilization (SFM) procedure in SIT. A 79-year-old woman with SIT was referred to our hospital for a locally advanced sigmoid cancer (cT3N1M0, cStageIIIB). We safely performed the laparoscopic sigmoidectomy with SFM, as shown in detail below. No postoperative complication occurred, and the patient is in good health with no recurrences 30 months after surgery, as of the writing this report. We propose three critical points; checking the CT angiography to understand the anatomy; using flip-horizontal video of "normal" laparoscopic sigmoidectomy to confirm an unfamiliar situation; adding the epigastric trocar to make SFM procedures safe and comfortable.

Given the worldwide popularization of conventional minimally invasive esophagectomy (C-MIE), robot-assisted MIE (RAMIE) can be expected to provide a finer procedure. However, controversy remains regarding whether RAMIE is superior to C-MIE in preventing recurrent laryngeal nerve (RLN) palsy. Considering the shallow learning curve for RAMIE, a novel procedure for lymphadenectomy along the RLN during RAMIE is needed. Based on a logical and simple understanding of the left upper mediastinum anatomy, the authors developed a novel “modified bascule method” for RAMIE that could simplify lymphadenectomy along the left RLN and prevent it from being touched and stretched. Between 2018 and 2020, 46 patients with esophageal carcinoma underwent RAMIE using this method at Kobe University. The modified bascule method was used to perform RAMIE for 29 men and 17 women with a median age of 67 years (range, 49–82 years). The median thoracoscopic procedure time was 438 min (range, 344–625 min), and the median console time was 351 min (range 273–518 min). The study harvested a median of 24 (range, 8–34) lymph nodes from the thoracic portion and 4 (range, 0–10) lymph nodes from along the left RLN. The mortality rate was 0%. Postoperative left RLN palsy classified as Clavien–Dindo (C–D) grade 1 or higher was observed for 9 patients (19%), whereas grade 2 or higher was not seen (0%). Pneumonia and anastomotic leakage rates higher than C–D grade 2 were respectively 13% and 19%. The novel modified bascule method for RAMIE can promote feasible lymphadenectomy along the left RLN even when performed during the learning period.

BACKGROUND/AIM The safety of neoadjuvant chemoradiotherapy (NACRT) combined with total mesorectal excision (TME) and selective lateral pelvic lymph node dissection (LLND) is unclear in elderly patients with locally advanced rectal cancer (LARC). PATIENTS AND METHODS Forty-two patients with LARC underwent TME and selective LLND following NACRT at Kobe University Hospital. The clinical outcomes were retrospectively compared between the elderly (aged ≥70 years, n=13) and non-elderly patients (aged

Background/aim Biomarkers for immune-related adverse events (irAEs) induced by immune checkpoint inhibitors (ICIs) are required. We encountered a patient whose skin irAE fluctuated in parallel with serum soluble interleukin-2 receptor (sIL-2R). Patients and methods We examined 15 patients with cancer who received ICIs. Serum sIL-2R levels before and during ICI treatment were measured. The sIL-2R levels of preserved serum samples from another five patients who developed grade 3 irAEs were measured. Results Twelve patients showed no significant changes in sIL-2R levels during ICI treatment. Baseline serum sIL-2R levels in three patients increased beyond the normal range before the second cycle. These three patients had grade ≥2 irAEs at the second cycle treatment visit, supporting our hypothesis. Furthermore, at diagnosis of irAEs, the sIL-2R levels of all preserved samples from patients with grade 3 irAEs were significantly elevated. Conclusion Serum sIL-2R is a promising biomarker for the diagnosis of irAEs.

Esophageal squamous cell cancer (ESCC) is one of the deadliest cancers in the world. Esophagectomy remains the principal treatment, and minimally invasive esophagectomy (MIE) has been performed worldwide. This study aimed to clarify whether the lymph node ratio (LNR), defined as the ratio of metastatic lymph nodes (LNs) to examined, is a prognostic factor for ESCC after MIE. This study included 327 MIEs with the patient in the prone position at two institutions from 2010 to 2015. Cox proportional hazards regression analyses using clinicopathologic characteristics and the LNR were performed for the pN1 patients and the whole cohort. In the multivariate analysis for all stages, independent prognostic factors were depth of tumor invasion (P

We developed herein photoluminescent glass ceramics based on rare-earth ion-doped Na5YSi4O12-type materials according to the Na3+3xY1−x−yRySi3O9 (R: Sm3+, Eu3+, Dy3+, Tb3+) composition. Glass ceramics generally have the advantages of excellent chemical durability, heat resistance, and moldability over sintered ceramics. Upon irradiation with near-ultraviolet light, Sm3+-, Eu3+-, Dy3+-, and Tb3+-doped glass ceramics emit purplish orange, reddish orange, yellow, and green lights, respectively. The photoluminescent emission intensity of glass ceramics is higher than that of the original glasses, and the emission intensity depends on the crystalline phase. The highest emission intensity of various rare-earth ion-doped glass ceramics is obtained when the parameter y is equal to 0.03, 0.16, and 0.02 for the Sm3+-, Eu3+-, and Dy3+-doped glass ceramic samples, respectively. The internal quantum efficiency is 3%, 37%, 7% and 23% for the Sm3+-, Eu3+-, Dy3+-, and Tb3+-doped samples, respectively. Thus the Na superionic conducting Na5YSi4O12-type glass-ceramics were proved to have potentiality as novel phosphors.

Purpose: Despite the increasing incidence of adenocarcinoma of the esophagogastric junction, laparoscopic proximal gastrectomy with lower esophagectomy (PGLE) is not widely accepted owing to the lack of standardized reconstruction techniques. In this study, we developed a new reconstruction method named y-shaped overlap esophagogastric tube reconstruction, which reproduces an angle of His and a pseudo-fornix, to be used in laparoscopic transhiatal PGLE. This study aimed to determine the feasibility of this novel reconstruction method.Methods: This retrospective study included the analysis of short- and mid-term surgical outcomes of 30 consecutive patients with Siewert type II esophagogastric junction adenocarcinoma who underwent laparoscopic PGLE with y-shaped overlap esophagogastric tube reconstruction from April 2015 to August 2020. A novel method was used to form a 6-cm pseudo-fornix and an angle of His using the distal esophagus and a long gastric tube.Results: The median operation time was 369 min, and the median blood loss was 28 mL. The median follow-up period after surgery was 37 months. Although two patients experienced postoperative anastomotic leakage, none of the patients developed stenosis. One patient experienced moderate reflux symptoms, whereas four patients developed moderate reflux esophagitis based on the 1-year follow-up endoscopic examination; the condition of all patients could be efficiently controlled with medication.Conclusion: The short- and mid-term surgical outcomes of y-shaped overlap esophagogastric tube reconstruction reflected the feasibility of this simple technique and suggested its potential utility as a reconstruction alternative for Siewert type II tumors.

No study has focused on the safety and feasibility of our previously developed open-window suturing technique to close mucosal defects on the pancreatic side after endoscopic submucosal dissection from the opened duodenal wall. This study aimed to evaluate the safety and usefulness of laparoscopic endoscopic cooperative surgery for duodenal tumors for treating superficial non-ampullary duodenal epithelial tumors on the pancreatic side of the duodenum.This retrospective study included 61 consecutive patients who underwent surgery during August 2014-November 2021. After dissection when the tumor was on the pancreatic side, we sutured the mucosal defect from the opened duodenal wall. A preoperative endoscopic pancreatic stent was placed for tumors within 1 cm of the ampulla of Vater. The surgical outcomes were compared between tumors on the pancreatic and non-pancreatic sides.There were 27 and 34 patients with tumors on the pancreatic and non-pancreatic sides, respectively. The patient characteristics were similar. Preoperative pancreatic stents were placed in four patients in the pancreatic side group. The median operative time was significantly longer on the pancreatic side than in the non-pancreatic side group (241 vs. 209 min, P = 0.02). In one patient in the pancreatic side group, an intraoperative injury of the ampulla of Vater was successfully treated with intraoperative management. There were no significant differences in the incidence of postoperative grade II or higher complications between the groups.Laparoscopic endoscopic cooperative surgery for duodenal tumors for treating superficial non-ampullary duodenal epithelial tumors on the pancreatic side is safe and feasible.

Subtotal cholecystectomy (SC) is a useful procedure for avoiding bile duct injury in patients with difficult gallbladder. However, risk factors for conversion to SC, especially preoperative magnetic resonance cholangiopancreatography (MRCP) findings that predict conversion to SC, have not been investigated in detail. A total of 290 patients with acute cholecystitis who underwent laparoscopic cholecystectomy at our hospital between November 2011 and March 2020 were included. Patient characteristics and perioperative outcomes were reviewed, and preoperative clinical factors predicting conversion to SC were investigated. Forty-three patients underwent SC, whereas the remaining 247 patients underwent total cholecystectomy. An American Society of Anesthesiologists (ASA) score of 3 or greater (p = 0.011), surgery on or after 9 days from symptom onset (p

Purpose Minimally invasive esophagectomy (MIE) has been increasingly used, but many reports have stated that recurrent laryngeal nerve (RLN) palsy after MIE is a major complication associated with postoperative pneumonia. Prevention of RLN palsy clearly has been a challenging task. The study aim was to determine if a three-dimensional (3-D) stereoscopic vision system can reduce the RLN palsy rate after MIE. Methods This was a retrospective study of MIE (McKeown esophagectomy) using a 3-D or 2-D stereoscopic vision system to treat 358 patients in the prone position between April 2010 and March 2019. The patients who underwent 3-D MIE (3-D group) or 2-D MIE (2-D group) were matched by using propensity score matching. After matching, the perioperative outcomes were compared between the groups. Results After propensity score matching, 154 patients were analyzed (77 patients, 3-D group; 77 patients, 2-D group). There were no significant differences in the patients’baseline characteristics in the matched cohort. There were no significant differences in the rates of pneumonia (Clavien–Dindo (C–D) grade ≥ II, 3-D vs. 2-D, 11 (14%) vs. 12 (16%)), anastomotic leakage (C–D grade ≥ II, 10 (13%) vs. 18 (23%)) and mortality. The rates of left RLN palsy (C–D grade ≥ IIIa, 1 (1.3%) vs. 7 (9.1%), P = 0.029), right RLN palsy (C–D grade ≥ I, 2 (3%) vs. 8 (10%), P = 0.049), comprehensive complication index (CCI®) (8.5 vs. 14.3, P = 0.011), and postoperative hospital stay period (median: 25 vs. 30 days, P = 0.034) were significantly lower in the 3-D group than in the 2-D group, respectively. Conclusions In MIE, the 3-D viewing system was one of the factors that reduced postoperative morbidities such as the rates of each RLN palsy and CCI®, leading to shorter postoperative hospital stay.

Although transanal total mesorectal excision (ta-TME) is adopted for rectal cancer surgery by an increasing number of surgeons, it is still technically challenging. We have employed a lateral-first approach for ta-TME to overcome technical difficulties. However, its outcomes and advantage over conventional laparoscopic TME remain unclear. Thirty-five consecutive patients who underwent ta-TME using a lateral-first approach (the ta-TME group) and 53 consecutive patients who underwent conventional laparoscopic TME (the lap-TME group) for low rectal cancer were included. Propensity score matching (PSM) was used to create balanced cohorts of ta-TME (n = 28) and lap-TME (n = 28). Their clinical outcomes were compared after PSM. The operative time and intraoperative blood loss were significantly lower in the ta-TME group than in the lap-TME group (P = 0.042 and P

Laparoscopic right hemicolectomy (LRH) is utilized worldwide as one of the standard surgical treatments for right‐sided colon cancer. However, there have been issues concerning its applicability, techniques, and trend. The present study aimed to elucidate the current status and trend of LRH by reviewing literature focusing on important issues associated with this surgery. Based on previous studies, LRH most likely provides better short‐term outcomes and similar oncological outcomes compared to open surgery. Despite the increasing use of robotic approach in this surgery, it seems to have always been associated with longer operative times and greater hospital cost with limited advantage. Intracorporeal anastomosis seems to improve short‐term outcomes, such as quicker recovery of bowel function, compared to extracorporeal anastomosis. However, it does not contribute to shorter hospital stay. With regard to dissection technique, various approaches, and landmarks have been advocated to overcome the technical difficulty in LRH. This difficulty is likely to be caused by anatomical variation, especially in venous structures. The superiority of one approach or landmark over another is still argued about due to the lack of large‐scale prospective studies. However, deep understanding both of anatomical variation and characteristics of each approach would be of extreme importance to minimize adverse effects and maximize patient benefit after LRH., The present study aimed to elucidate the current status and trend of laparoscopic right hemicolectomy by reviewing literature focusing on important issues associated with this surgery.

Objectives: Dissection of the No. 11p lymph nodes is technically challenging because of variations in anatomical landmarks. This study aimed to determine the accuracy and efficacy of predicting the dorsal landmark of No. 11p lymph node using three-dimensional computed tomography simulation. Methods: Laparoscopic gastrectomy with No. 11p lymph node dissection with preoperative simulation using three-dimensional computed tomography was performed in 24 patients at our institution from October 2016 to May 2018. Initially, preoperative three-dimensional computed tomography findings with operative videos in these 24 patients were compared. The dorsal landmark was defined as an anatomical structure behind the splenic artery on preoperative three-dimensional computed tomography and operative videos. The dorsal landmark of No. 11p lymph node was divided into four types: (1) splenic vein type, (2) splenic vein and pancreas type, (3) pancreas type, and (4) unclear type. Then, to investigate the efficacy of three-dimensional computed tomography, we compared the clinical and pathological features and surgical outcomes of nine patients who underwent preoperative three-dimensional computed tomography simulation (three-dimensional computed tomography group) and 23 patients who did not undergo three-dimensional computed tomography simulation from August 2014 to September 2016 (non-three-dimensional computed tomography group). All procedures were performed by one surgeon certified by the Endoscopic Surgical Skill Qualification System in Japan. Results: The concordance rate between three-dimensional computed tomography and operative videos of the dorsal landmark using three-dimensional computed tomography was 79% (19/24). The operative time of No. 11p lymph node dissection was significantly shorter in the three-dimensional computed tomography group than in the non-three-dimensional computed tomography group (7.7 versus 15.8 min, P = 0.044). Conclusion: The accuracy of predicting the dorsal landmark of No. 11p lymph node using three-dimensional computed tomography was extremely high. Preoperative simulation with three-dimensional computed tomography was useful in shortening the operative time of No. 11p lymph node dissection.

This study was conducted to determine whether establishing the proximal resection line using India ink tattooing can ensure safe resection margins during totally laparoscopic distal gastrectomy. This retrospective study included 81 patients who underwent totally laparoscopic distal gastrectomy for gastric cancer on the lower two-thirds of the stomach. The proximal resection margins were analyzed with respect to the macroscopic type and clinical T stage, and the intraoperative appearance of the stain on the serosa was classified by reviewing surgical videos. R0 resection was performed in all patients. The rates of the intended margins were 89.2% in patients without a frozen section diagnosis and 84.2% in patients with differentiated type lesions who underwent a frozen section diagnosis; however, most patients with undifferentiated advanced lesions failed to achieve the intended resection margins. Intraoperative appearance revealed that 85.2% of patients had localized type stains, whereas 11.1% had widespread-type stains. Our procedure to determine the proximal resection line in totally laparoscopic distal gastrectomy is oncologically safe. However, careful observation of the resected specimen and a frozen section analysis should be performed for undifferentiated advanced lesions.

Inguinal bladder hernia is a rare clinical condition, and only a small number of reported cases have been treated by laparoscopic surgery. In the present case, the patient was a 78-year-old man who presented to our emergency department with a chief complaint of right inguinal bulge and pain. CT imaging revealed an incarcerated right inguinal hernia containing the small intestine and a portion of the urinary bladder. We performed manual reduction of the incarcerated intestine, and he was admitted to the surgical ward for follow-up. On the 19th day after discharge, recurrence of incarceration developed, and he was readmitted after manual reduction. A laparoscopic transabdominal preperitoneal repair was performed. After careful reduction of the protruding bladder from the hernial orifice, we repaired the right inguinal hernia with a mesh prosthesis. We experienced a rare case of right indirect inguinal bladder hernia that was treated successfully with laparoscopic repair.

The influence of anastomotic leakage on long-term survival in patients with rectal cancer is debatable. The aim of this study was to evaluate relationships between anastomotic leakage and long-term survival. In this multicenter retrospective cohort study, 395 consecutive stage I to III rectal cancer patients underwent anterior resection between 2007 and 2012. Five-year overall survival, 5-year disease-free survival, and 5-year local recurrence-free survival were compared between patients with leakage (Leakage (+)) and patients without leakage (Leakage (−)). Of 395 patients, 50 (12.7%) had anastomotic leakage. Of these 50, 34 (68.0%) required urgent surgery and 16 (32.0%) could be managed by watchful waiting or with percutaneous drainage. The median follow-up period was 62.6 months. Five-year overall survival did not differ between the two groups (Leakage (+) 93.8% vs. Leakage (−) 89.0%, P = 0.121). Five-year disease-free survival also did not differ between the two groups (81.6% vs. 80.3%, P = 0.731), and neither did 5-year local recurrence-free survival (91.9% vs. 86.1%, P = 0.206). In a multivariable Cox regression model, BMI > 25, preoperative CA19-9 > 37, pathological T stage, pathological N stage, and circumferential resection margin (CRM) positive were independent predictors of disease-free survival. Moreover, pathological T stage, pathological N stage, and CRM positive were the only independent predictors of overall survival and local recurrence-free survival. Anastomotic leakage was not a risk factor for overall survival, disease-free survival, or local recurrence-free survival. Anastomotic leakage is not associated with a significant decrease in long-term survival in rectal cancer patients.

We succeeded in the electrical polarization of β-tricalcium phosphate (β-TCP) granules and performed an unprecedented attempt to implant them into maxillary bone defects in canines to confirm their ability to facilitate new bone formation. Two holes were drilled into each maxilla half of a canine and filled with electrically polarized and nonpolarized β-TCP granules (grouping assignment was decided randomly). The implanted specimens were dissected en bloc and used for microcomputed tomography (μCT) observations and histological analyses 4 and 8 weeks after the operation. New bone ingrowth in the bone hole progressed over time from the superficial layer of the cortex toward the inner cancellous bone. The percentage area of new bone in the bone hole, as measured by μCT in the sagittal plane, was significantly larger after 4 and 8 weeks, and that measured by H&E-stained specimens in the transverse plane after 4 weeks was significantly larger in the polarized group than in the nonpolarized group. In addition to the structural stability and chemical characteristics of the β-TCP granules, electrical stimulation bears influence not indirectly but directly on osteogenic and vessel cells, which might work cooperatively for the early initiation of the bone formation process.

Background/aim To investigate the outcomes of laparoscopic surgery in colorectal cancer patients with dialysis. Patients and methods Fourteen dialysis (dialysis group) and 567 non-dialysis (non-dialysis group) patients who underwent laparoscopic and open surgery for colorectal cancer between April 2008 and December 2015 were included. Short-term and long-term outcomes were compared between the groups. A 1:2 propensity score matching was performed to compare long-term outcomes. Results All the dialysis patients underwent laparoscopic surgery. There were no significant differences in operative outcomes and postoperative short-term outcomes between the two groups. In the whole cohort, overall survival of dialysis patients was shorter than that in the non-dialysis ones (p=0.020), while disease-free survival did not differ between the two groups. After matching, there was no significant difference between the groups in overall or disease-free survival. Conclusion Laparoscopic colorectal cancer surgery for dialysis patients seems safe and feasible and associates with comparable short-term outcome and recurrence rate to non-dialysis patients.

Background For patients with Grade III acute cholecystitis (AC), several factors have been proposed in the 2018 Tokyo guidelines as caution signs in performing early surgery. However, these factors have not been externally validated in detail. Methods This retrospective study examined 35 patients who had been diagnosed with Grade III AC and treated with laparoscopic cholecystectomy between January 2008 and July 2019. The patients were allocated into an early group (patients who underwent surgery within 7 days of admission, n = 28) and a delayed group (patients who underwent surgery at least 8 days after admission, n = 7). Comparisons were made between these groups. Results No patients died. Significantly more patients required a conversion to open surgery (0% vs 28.5%, P = .003) or conversion to subtotal cholecystectomy (25.0% vs 71.4%, P = .020) in the delayed group than in the early group, and the total length of postoperative stay was significantly longer in the delayed group (11.4 vs 27.2 days, P = .001). The presence of negative predictive factors or risk factors listed in the 2018 Tokyo guidelines was not associated with death or postoperative complications. Conclusions Early surgery was considered appropriate and feasible for select patients who had Grade III AC and preoperative risk factors.

In recent years, the usefulness of neoadjuvant chemotherapy for resectable advanced gastric cancer, particularly stage III, has been reported. Preoperative staging is mainly determined by computed tomography (CT), and the usefulness of 18F-fluoro-2-deoxyglucose positron emission tomography/CT (FDG-PET/CT) for gastric cancer remains unclear. The study aimed to evaluate the usefulness of FDG-PET/CT in preoperative diagnosis of advanced gastric cancer. We retrospectively enrolled 113 patients with gastric cancer who underwent preoperative FDG-PET/CT. All patients underwent gastrectomy with lymph-node dissection. The maximum standardized uptake value (SUVmax) of the primary tumor (T-SUVmax) and lymph nodes (N-SUVmax) were measured for all patients. The cutoff values of T-SUVmax for pathological T3/4 from receiver operating characteristic analysis were 8.28 for differentiated and 4.32 for undifferentiated types. The T-SUVmax and N-SUVmax cutoff values for pathological lymph-node metastasis were 4.32 and 1.82, respectively. Multivariate analysis showed that T-SUVmax for differentiated types was a significant predictor of pathological T3/4, and N-SUVmax was a significant predictor of lymph-node metastasis. In conclusion, the SUVmax of FDG-PET/CT was a useful predictor of pathological T3/4 and lymph-node metastasis in gastric cancer. The diagnosis by preoperative FDG-PET/CT allowed a more accurate staging of gastric cancer than by CT scan alone.

Esophageal squamous cell carcinoma (ESCC) is a deadly malignant disease. This study examined whether the platelet-to-lymphocyte ratio (PLR) can be used as a biomarker to evaluate prognosis in patients with advanced ESCC following neoadjuvant chemotherapy (NAC) and undergoing minimally invasive esophagectomy (MIE).We examined 174 patients between January 2010 and December 2015 at the Kobe University. Of these, 121 were treated with NAC. The PLR cutoff was determined through receiver-operating characteristic curve analysis. Univariate and multivariate analyses were conducted to identify prognostic factors for overall survival (OS).The PLR cutoff for OS in 121 patients was 169.6. Patients with PLR ≥169.6 had worse 5-year OS rates (31.1%) than those with a PLR169.6 (61.1%, p=0.001). Multivariate analysis revealed that a PLR of ≥169.6 was an independent factor for poor prognosis.PLR is an independent prognostic factor for patients with ESCC after NAC and MIE.

Purpose This study aimed to compare motions of the laparoscope tip during a laparoscopic task in a training box using a recent joystick-guided robotic scope holder to those manipulated by human scopists. We hypothesized that laparoscopic manipulation could be positively affected by robotic scope holders due to the elimination of unintentional movement. Methods Twelve surgeons participated as operators, and eight medical doctors participated in this study. Among the human scopists, five were trained surgeons and three were novices who had no experience with laparoscopic surgery. A validated laparoscopic task was used to evaluate the path length of the laparoscope tip using an optical position tracker and operative time. The operators performed the designated camera task under three different laparoscopic manipulations: using a joystick-guided robotic scope holder, expert human scopists, and novice scopists. Results The median path lengths (cm) of the laparoscopic tip were 94.0, 110.0, and 122.2 in the robotic scope holder, expert, and novice groups, respectively. The path lengths in the robotic scope holder group were significantly shorter than those in the other groups (P < .01). The median operative times (seconds) were 136.6, 66.4, and 62.3 in the robotic scope holder, expert, and novice groups, respectively. The operative time of the robotic scope holder group was significantly longer than that of the other groups (P < .001). Conclusion A robotic scope holder can provide shorter camera movement owing to the stable holding and intentional scope manipulation by the operator, although it requires a longer operative time than a human assistant.

This study aimed to identify prognostic factors for adenocarcinoma of the esophagogastric junction (AEG) in Siewert type II and characterize the population whose prognosis is expected to improve.We retrospectively reviewed a database of 68 AEG type II patients who had undergone surgical curative resection without preoperative treatment.Although patients with pathological N0 (pN0) showed favorable 3-year disease-free survival (91%), patients with pN1-3 had poor outcomes (42%, 23%, and 10%). Multivariate analyses showed that the only independent prognostic factor was lymph node metastasis, and that tumor depth (cT3-4) and tumor size (≥4 cm) were correlated closely with lymph node metastasis.Surgical curative resection without preoperative treatment is insufficient to treat AEG type II with lymph node metastasis. Among AEG patients, those with the high-risk factors of preoperative tumor depth (T3-4) or/and size (≥4 cm) might need intensive multimodal treatment, including perioperative adjuvant chemotherapy.

Background: With the aging population, more patients are expected to receive antithrombotic treatment. Although many studies have investigated the perioperative management of antithrombotic therapy, few have targeted gastrectomy. Hence, the safety of gastrectomy for patients receiving antithrombotic agents remains unclear. This retrospective cohort study sought to compare outcomes between patients who did and did not receive antithrombotic agents.Methods: This single-center retrospective cohort study included 548 patients who underwent gastrectomy for primary gastric adenocarcinoma from January 2011 to December 2019. Patients were subsequently classified into two groups according to whether they received antithrombotic therapy (n = 121) or not (n = 427), after which surgical outcomes were compared. Propensity score analysis was performed based on age, sex, body mass index, open versus laparoscopic surgery, and total versus distal gastrectomy. After propensity score matching, 121 patients were included in each group.Results: Among the entire cohort, receiving antithrombotic therapy group was significantly older than those who did not (age ≥ 75 years, 48% vs. 33%; p ≤ 0.0001). Those receiving antithrombotic therapy had significantly higher postoperative complication rates than those who did not (33.1% vs. 23.9%; p = 0.046). After matching, no significant difference in the postoperative complication rate was observed between both groups.Conclusion: Despite having a high risk for postoperative complications, patients receiving antithrombotic therapy can safely undergo gastric resection.

Context: Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immune cells of myeloid lineage. Recent reports have suggested that human MDSC are divided into three subsets: monocytic MDSC (M-MDSC), granulocytic MDSC (G-MDSC), and immature MDSC (I-MDSC). However, the characteristics of each human MDSC subset still remain unclear. Materials and Methods: To evaluate the immunosuppressive effects and mechanisms, we first performed a T-cell suppression assay using cells obtained from healthy donor peripheral blood samples. The levels of immune inhibitory molecules in the culture supernatant of each MDSC subset were measured to reveal the T-cell suppressive mechanisms. Then, we compared these results with the results from cells obtained from cancer patient blood samples. Finally, we investigated the difference in the frequency of each MDSC subset between the healthy donors and the cancer patients. Results: Although M-MDSC and G-MDSC suppressed T-cell activation, I-MDSC had no T-cell suppressive effect. We found that the culture supernatant of M-MDSC and G-MDSC contained high levels of interleukin-1 receptor antagonist (IL-1RA) and arginase, respectively, in both healthy donors and cancer patients. No inhibitory molecules were detected in the culture supernatant of I-MDSC. The population of functional MDSC (M-MDSC and G-MDSC) in the total MDSC was significantly increased in cancer patients compared with that in healthy donors. Conclusions: Although M-MDSC and G-MDSC, which released IL-1RA and arginase, respectively, suppressed T-cell activation, I-MDSC did not have an immunosuppressive effect. The population of functional MDSC was increased in cancer patients compared with that in healthy donors.

The eighth edition of the American Joint Committee on Cancer (AJCC) tumor node metastasis (AJCC-TNM 8th) system adopted the newly separate post-neoadjuvant pathologic stage group (ypTNM). However, it is not compatible with the Japanese pathologic classification after neoadjuvant chemotherapy (JPN-CT-pTNM). The aim of this study is to clarify the subjects of the AJCC-ypTNM 8th and propose a unification of the AJCC and Japanese systems to create novel AJCC-CT-pTNM 8th.Participants were 304 esophageal squamous cell carcinoma (ESCC) patients who underwent neoadjuvant chemotherapy followed by 3 stage esophagectomy between 2010 and 2019. Predictive probabilities of pN, pM in AJCC-ypTNM 8th and JPN-CT-pTNM 11th systems were evaluated to propose novel system.In training data from 234 patients, the overall survival rate was statistically better for ypStage IIIA than ypStage II (P = 0.040) resulting in staging inversion in AJCC-ypTNM 8th. Predictive probability of pathological N status in AJCC-ypTNM 8th (Akaike Information Criterion: AIC = 979.53) was superior to that in JPN-CT-pTNM 11th (AIC = 999.07). In AJCC-ypTNM 8th, 71% (15/21) of ypM1 diseases were supraclavicular lymph nodes (No. 104 L/N as regional in JPN-CT-pTNM 11th) metastases with considerably good prognosis. The predictive probability of the novel AJCC-CT-pTNM 8th [unification of ypStage II and IIIA, conversion of supraclavicular L/Ns metastases from ypM to ypN] (AIC = 1054.24) was superior to that of the existing AJCC-ypTNM 8th (AIC = 1070.74). The feasibility of novel system was validated using test data from 70 patients.Unification of the AJCC and Japanese systems yields a simpler and more precise predictive system after neoadjuvant chemotherapy.