Measurement of changes in serum-based inflammatory indicators to monitor response to nivolumab monotherapy in advanced gastric cancer: a multicenter retrospective study.

BACKGROUND: Nonresectable gastric cancer develops rapidly; thus, monitoring disease progression especially in patients receiving nivolumab as late-line therapy is important. Biomarkers may facilitate the evaluation of nivolumab treatment response. Herein, we assessed the utility of serum-based inflammatory indicators for evaluating tumor response to nivolumab. METHODS: This multicenter retrospective cohort study included 111 patients treated with nivolumab monotherapy for nonresectable advanced or recurrent gastric cancer from October 2017 to October 2021. We measured changes in the C-reactive protein (CRP)-to-albumin ratio (CAR), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) in serum from baseline to after the fourth administration of nivolumab. Furthermore, we calculated the area under the receiver operating characteristic curves (AUC ROCs) for CAR, PLR, and NLR to identify the optimal cutoff values for treatment response. We also investigated the relationship between clinicopathologic factors and disease control (complete response, partial response, and stable disease) using the chi-squared test. RESULTS: The overall response rate (complete and partial response) was 11.7%, and the disease control rate was 44.1%. The median overall survival (OS) was 14.0 (95% CI 10.7‒19.2) months, and the median progression-free survival (PFS) was 4.1 (95% CI 3.0‒5.9) months. The AUC ROCs for CAR, PLR, and NLR before nivolumab monotherapy for patients with progressive disease (PD) were 0.574 (95% CI, 0.461‒0.687), 0.528 (95% CI, 0.418‒0.637), and 0.511 (95% CI, 0.401‒0.620), respectively. The values for changes in CAR, PLR, and NLR were 0.766 (95% CI, 0.666‒0.865), 0.707 (95% CI, 0.607‒0.807), and 0.660 (95% CI 0.556‒0.765), respectively. The cutoff values for the treatment response were 3.0, 1.3, and 1.4 for CAR, PLR, and NLR, respectively. The PFS and OS were significantly longer when the treatment response values for changes in CAR, PLR, and NLR were below these cutoff values (CAR: OS, p < 0.0001 and PFS, p < 0.0001; PLR: OS, p = 0.0289 and PFS, p = 0.0302; and NLR: OS, p = 0.0077 and PFS, p = 0.0044). CONCLUSIONS: Measurement of the changes in CAR, PLR, and NLR could provide a simple, prompt, noninvasive method to evaluate response to nivolumab monotherapy. TRIAL REGISTRATION: This study is registered with number K2023006.

Safety and feasibility of minimally invasive gastrectomy following preoperative chemotherapy for highly advanced gastric cancer.

BACKGROUND: This study aimed to determine the safety and feasibility of minimally invasive gastrectomy in patients who underwent preoperative chemotherapy for highly advanced gastric cancer. METHODS: Preoperative chemotherapy was indicated for patients with advanced large tumors (≥ cT3 and ≥ 5 cm) and/or bulky node metastasis (≥ 3 cm × 1 or ≥ 1.5 cm × 2). Between January 2009 and March 2022, 150 patients underwent preoperative chemotherapy followed by gastrectomy with R0 resection, including conversion surgery (robotic, 62; laparoscopic, 88). The outcomes of these patients were retrospectively examined. RESULTS: Among them, 41 and 47 patients had stage IV disease and underwent splenectomy, respectively. Regarding operative outcomes, operative time was 475 min, blood loss was 72 g, morbidity (grade ≥ 3a) rate was 12%, local complication rate was 10.7%, and postoperative hospital stay was 14 days (Interquartile range: 11-18 days). Fifty patients (33.3%) achieved grade ≥ 2 histological responses. Regarding resection types, total/proximal gastrectomy plus splenectomy (29.8%) was associated with significantly higher morbidity than other types (distal gastrectomy, 3.2%; total/proximal gastrectomy, 4.9%; P < 0.001). Specifically, among splenectomy cases, the rate of postoperative complications associated with the laparoscopic approach was significantly higher than that associated with the robotic approach (40.0% vs. 0%, P = 0.009). In the multivariate analysis, splenectomy was an independent risk factor for postoperative complications [odds ratio, 8.574; 95% confidence interval (CI), 2.584-28.443; P < 0.001]. CONCLUSIONS: Minimally invasive gastrectomy following preoperative chemotherapy was feasible and safe for patients with highly advanced gastric cancer. Robotic gastrectomy may improve surgical safety, particularly in the case of total/proximal gastrectomy combined with splenectomy.

Standardized procedure for preventing late intestinal complications following minimally invasive total gastrectomy for gastric cancer: a single-center retrospective cohort study.

BACKGROUND: Although minimally invasive total gastrectomy for gastric cancer is commonly performed, reports regarding late complications are limited. We have made several improvements each time we experienced severe late complications since 2009. This study aimed to evaluate the clinical efficacy of these improved procedures in preventing late complications. METHODS: Between January 2009 and December 2019, 302 patients who underwent laparoscopic or robotic total gastrectomy for gastric cancer were enrolled. The patients were divided into two groups: Period-I (2009-2013, before established standardization of procedure, 166 patients) and Period-II (2014-2019, after established standardization of procedure, 136 patients). The standardized procedure comprised four major steps, including closure of the mesentery defects and diaphragm crus, circumferential fixation of the anastomotic site into the diaphragm, and linearization around the anastomotic site of esophagojejunostomy. The incidence of late complications was retrospectively compared between the two groups. RESULTS: Late overall complications that occurred over 30 days after surgery were observed in 19 (6.3%) patients. In all, 14 of 24 (58.3%) patients admitted due to late intestinal complications eventually required reoperation for treatment. The most frequent complication was nonstenotic outlet obstruction of the distal jejunal limb. The incidence of late overall complications was significantly lower in Period-II than in Period-I (2.9 vs 9.0%, p = 0.030). Intestinal complications were reduced considerably in Period-II. The 3-year cumulative incidence rate of late overall complications was significantly lower in Period-II than in Period-I (0.03 vs 0.10, p = 0.035). Period-I as the only independent risk factor for the development of late intestinal complications. CONCLUSION: Late complications after laparoscopic total gastrectomy sometimes occurred, and more than half of the patients with intestinal complications required reoperation. Our standardized procedure was associated with a lower risk of late intestinal complications after minimally invasive total gastrectomy followed by intracorporeal esophagojejunostomy using linear staplers in a cohort of patients with gastric cancer.

Task division by multiple console surgeons is beneficial for safe robotic pancreaticoduodenectomy implementation and education.

BACKGROUND: The optimal approach for the safe implementation and education of robotic pancreaticoduodenectomy (RPD) remains unclear. Prolonged operation time may cause surgeon fatigue and result in perioperative complications. To solve this issue, our department adopted task division by the console surgeon turnover between resection and reconstruction in 2022. METHODS: This study retrospectively investigated consecutive patients who underwent RPD from November 2009 (initial introduction of RPD) to December 2023. The analysis excluded patients who underwent concomitant resection of other organs. The cases performed by a single console surgeon (single approach) were compared with those performed by two or more console surgeons (multiple approach). RESULTS: This study analyzed 85 consecutive RPD cases, including 51 with the single approach and 34 with the multiple approach. The operation time was significantly shorter (832 vs. 618 min, p < 0.001), and the postoperative major complication was less frequent (45% vs. 12%, p = 0.003) in the multiple approach group, although less experienced surgeons performed the multiple approach (number of RPD experiences: 19 cases vs. 5 cases, p < 0.001). The console surgeon turnover between the resection and reconstruction resulted in a safe pancreatojejunostomy performed by the less experienced surgeon (number of pancreatic reconstruction experiences: 6.5 vs. 14 cases, p = 0.010). Surgeons who started RPD with a multiple approach observed a reduction in surgical time and a lower incidence of complications earlier than those who started with a single approach. CONCLUSION: Task division during the early introduction phase of RPD using the multiple approach demonstrated potential contributions to improved surgical outcomes and enhanced educational benefits.

Impact of the endoscopic surgical skill qualification system on the oncological safety of laparoscopic gastrectomy for gastric cancer: A single-center retrospective cohort study.

BACKGROUND: This study aimed to investigate the laparoscopic gastrectomy (LG) performance of non-Endoscopic Surgical Skill Qualification System (ESSQS)-qualified surgeons under the ESSQS-qualified surgeon guidance and compare oncological outcomes of gastric cancer to LG performed by the ESSQS-qualified surgeons. METHODS: This study enrolled 1,030 patients diagnosed with both clinical and pathological stage ≤ III gastric cancer and undergoing LG from January 2009 to June 2019. ESSQS-qualified surgeons served as the operator or the instructive assistant in all LG procedures involving them. A propensity score-matched analysis was used to retrospectively compare the long-term outcomes between the ESSQS-qualified and non-ESSQS-qualified surgeons. RESULTS: Each group included 315 pairs after propensity score matching. The 3-year recurrence-free survival rates were 84.4% and 81.7% in the non-ESSQS and ESSQS groups, respectively. The difference was 2.7% (95% confidence interval: - 3.20%-8.44%, P < 0.001), and the non-ESSQS group statistically demonstrated noninferiority as the lower 95% confidence limit was greater than the prespecified margin of -10%, indicating the achieved primary endpoint. No significant differences in 5-year recurrence-free survival (non-ESSQS: 78.5% vs. ESSQS: 77.4%, P = 0.627) and 5-year overall survival (non-ESSQS: 80.9% vs. ESSQS: 79.3%, P = 0.475) were found between the two groups. The oncological outcomes stratified according to the presence of pathological stage I, II, and III disease did not significantly differ between the two groups. CONCLUSIONS: LG performed by non-ESSQS-qualified surgeons achieved comparable oncological outcomes to the ESSQS-qualified surgeons, as long as ESSQS-qualified surgeons provided intraoperative instructions, in a high-volume center.

First clinical experiences of robotic gastrectomy for gastric cancer using the hinotori™ surgical robot system.

BACKGROUND: Although the da Vinci™ Surgical System is the most predominantly used surgical robot worldwide, other surgical robots are being developed. The Japanese surgical robot hinotori™ Surgical Robot System was launched and approved for clinical use in Japan in November 2022. We performed the first robotic gastrectomy for gastric cancer using hinotori in the world. Here, we report our initial experience and evaluation of the feasibility and safety of robotic gastrectomy for gastric cancer using hinotori. METHODS: A single-institution retrospective study was conducted. Between November 2022 and October 2023, 24 patients with gastric cancer underwent robotic gastrectomy with hinotori. Five ports, including one for an assistant, were placed in the upper abdomen, and gastric resection with standard lymphadenectomy and intracorporeal reconstruction were performed. The primary endpoint was the postoperative complication rate within 30 days after surgery. The secondary outcomes were surgical outcomes, including intraoperative adverse events, operative time, blood loss, and the number of dissected nodes. RESULTS: Of the 24 patients, 16 (66.7%) were male. The median age and body mass index were 73.5 years and 22.9 kg/m2, respectively. Twenty-three patients (95.8%) had tumors in the middle to lower stomach. Sixteen (66.7%) and seven (29.2%) patients had clinical stage I and II diseases, respectively. Twenty-three (95.8%) patients underwent distal gastrectomy. No patient had postoperative complications of Clavien-Dindo classification IIIa or higher, whereas two (8.3%) had the grade II complications (enteritis and pneumonia). No intraoperative adverse events, including conversion to other approaches, were observed. All patients received R0 resection. The median operative and console times were 400 and 305 min, respectively. The median blood loss was 14.5 mL, and the number of lymph nodes dissected was 51.5. CONCLUSIONS: This study found that robotic gastrectomy with standard lymphadenectomy for gastric cancer using hinotori can be safely performed.

Challenge in optimizing robotic pancreaticoduodenectomy including nerve plexus hanging maneuver: a Japanese single center experience of 76 cases.

BACKGROUND: Robotic pancreaticoduodenectomy (RPD) is technically demanding, and 20-50 cases are required to surpass the learning curve. This study aimed to show our experience of 76 cases from the introduction of RPD and report the changes in surgical results owing to the accumulation of cases and optimization of surgical techniques. METHODS: A total of 76 patients who underwent RPD between November 2009 and May 2023 at the Fujita Health University Hospital were divided into three groups: competency (n = 23, Nov 2009-Mar 2020), proficiency (n = 31, Apr 2020-Jun 2022), and mastery (n = 22, Jul 2022-May 2023) phases. In the mastery phase, for the education of new surgeons and maintenance of surgical quality, optimization of the procedure, including hanging maneuver with or without stapling transection of the retropancreatic tissue was implemented. The surgical outcomes were compared between the groups. RESULTS: The mean operation time decreased over time despite of the participation of newly started operators in mastery phase [competency: 921.5 min (IQR 775-996 min) vs. proficiency: 802.8 min (IQR 715-887 min) vs. mastery: 609.2 min (IQR 514-699 min), p < 0.001]. Additionally, Clavien-Dindo ≥ grade IIIa complications decreased from 52.2% in competency phase to 35.5% and 9.1% in proficiency and mastery phases, respectively (p = 0.005). CONCLUSION: Operation time and major complications decreased along the learning curve from the introduction of RPD. In addition, optimization of the procedure, including hanging maneuver of the retropancreatic tissue seemed to be effective in reducing operation time and educating new RPD surgeons.

Technical details of robotic pancreatojejunostomy using a modified Blumgart anastomosis: Thread manipulation using gauze and an assisted port.

BACKGROUNDS: Pancreatojejunostomy is a technically demanding procedure during robotic pancreaticoduodenectomy (RPD). Modified Blumgart anastomosis (mBA) is a common method for the pancreatojejunostomy; however, the technical details for robotic mBA are not well established. During RPD, we performed a mBA for the pancreatojejunostomy using thread manipulation with gauze and an additional assist port. METHODS: Patients who underwent robotic pancreatoduodenectomy at Fujita Health University from November 2009 to May 2023 were retrospectively investigated, and technical details for the robotic-modified Blumgart anastomosis were demonstrated. RESULTS: Among 78 patients who underwent RPD during the study period, 33 underwent robotic mBA. Postoperative pancreatic fistula (POPF) occurred in six patients (18%). None of the patients suffered POPF Grade C according to the international study group of pancreatic surgery definition. The anastomotic time for mBA was 80 min (54-125 min). CONCLUSION: Robotic mBA resulted in reasonable outcomes. We propose that mBA could be used as one of the standard methods for robotic pancreatojejunosotomy.

The safe implementation of peripherally inserted central catheters by nurse practitioners for patients with gastroenterological diseases in Japan: a single-center retrospective study.

PURPOSE: As a safe and reliable alternative to central venous catheters (CVCs), peripherally inserted central catheters (PICCs) are commonly used in clinical practice. However, the insertion of PICCs by nurse practitioners (NPs), especially in Japan, has not been reported extensively. Thus, we investigated the safety and efficiency of PICC insertions by NPs. METHODS: The participants were 1322 patients who underwent PICC insertion by NPs at Fujita Health University Hospital (FNPs). The basilic vein in the brachium was the preferred vein for insertion; the brachial vein was the alternative. Patients were monitored from the time of PICC insertion until its removal. Ultrasonography-guided puncture was used for all catheter insertions, and the catheter tip was replaced into the superior vena cava under fluoroscopic imaging with maximal sterile barrier precautions. The outcomes of the PICC insertions by the FNPs were evaluated retrospectively. RESULTS: Overall, 23 FNPs inserted a collective total of 1322 PICCs, which remained in place for a collective total of 23,619 catheter days. The rate of successful PICC insertion was 99% (1310 patients). The median time taken for PICC insertion was 12 min (interquartile range, 10-15 min). Intraoperative complications occurred in two patients (0.2%). The confirmed incidence of central line-associated bloodstream infection was 3.4% (45 patients), and these infections occurred on 1.9 per 1000 catheter days. The median duration of PICC placement was 15 days (range, 10-23 days). CONCLUSION: PICC insertion by NPs is safe and a potential alternative to CVC insertion by surgeons.

Robotic gastrectomy for gastric cancer: systematic review and future directions.

BACKGROUND: Robotic gastrectomy (RG) using the da Vinci Surgical System for gastric cancer was approved for national medical insurance coverage in Japan in April 2018, and its number has been rapidly increasing since then. AIM: We reviewed and compared current evidence on RG and conventional laparoscopic gastrectomy (LG) to identify the differences in surgical outcomes. METHODS: Three independent reviewers systematically reviewed the data collected from a comprehensive literature search by an independent organization, focusing on the following nine endpoints: mortality, morbidity, operative time, estimated blood loss volume, length of postoperative hospital stay, long-term oncologic outcome, quality of life, learning curve, and cost. RESULTS: Compared to LG, RG has lower intraoperative blood loss volume, shorter length of hospital stay, and shorter learning curve, but both procedures have similar mortality. Contrarily, its disadvantages include longer procedural time and higher costs. Although the morbidity rate and long-term outcomes are almost comparable, RG showed superior potentials. Currently, the outcomes of RG are considered comparable to or better than LG. CONCLUSION: RG might be applicable to all gastric cancer patients who fulfill the indication of LG at institutions that meet specific criteria and are approved to claim the National Health Insurance costs for the use of the surgical robot in Japan.

Robotic esophagectomy with outermost layer-oriented dissection for esophageal cancer: technical aspects and a retrospective review of a single-institution database.

BACKGROUND: Systematic lymph node dissection in patients with gastric cancer could be sufficiently and reproducibly achieved along the outermost layer of the autonomic nerves and similar concept has been extensively used for robotic esophagectomy (RE) since 2018. This study aimed to determine the surgical and oncological safety of RE using the outermost layer-oriented approach for esophageal cancer (EC). METHODS: Sixty-six patients who underwent RE with total mediastinal lymphadenectomy for primary EC between April 2018 and December 2021 were retrospectively reviewed. All underwent the outermost layer-oriented approach with intraoperative nerve monitoring (IONM). Postoperative complications within 30 days were analyzed. RESULTS: Among the patients, 51 (77.3%) were male. The median age was 64 years, and the body mass index was 21.8 kg/m2. Furthermore, 58 (87.9%) patients had squamous cell carcinoma and eight (12.1%) patients had adenocarcinoma. Clinical stages I, II, and III were seen in 23 (34.8%), 23 (34.8%), and 16 (24.2%) patients, respectively. Thirty-four (51.5%) patients received preoperative treatment. No patient shifted to conventional thoracoscopic or open procedure intraoperatively. The median operative time was 716 min with 119 mL of blood loss. Additionally, 64 (97%) patients underwent R0 resection. The morbidity rates based on Clavien-Dindo grades ≥ II and ≥ IIIa were 30.3% and 10.6%, respectively, within 30 postoperative days. None died within 90 days postoperatively. Three (4.5%) patients exhibited recurrent laryngeal nerve (RLN) palsy (CD grade ≥ II). The sensitivity and specificity of IONM for RLN palsy were 50% and 98.3% at the right RLN and 33.3% and 98.0% at the left RLN, respectively. CONCLUSION: RE with the outermost layer-oriented approach can provide safe short-term outcomes.

Muscle mass ratio in male gastric cancer patients as an independent predictor of postoperative complications after minimally invasive distal gastrectomy.

BACKGROUND: The current study aimed to investigate the relationship between muscle mass proportion and the incidence of total complications in male gastric cancer (GC) patients after minimally invasive distal gastrectomy (MIDG). METHODS: Between March 2017 and March 2020, 152 male GC patients with clinical stage III or lower GC who underwent MIDG were enrolled in this study. The muscle mass ratio (MMR) was calculated by dividing the total muscle weight obtained from bioelectrical impedance analysis by the whole-body weight. Thereafter, the association between MMR and surgical outcomes was determined. RESULTS: Based on the optimal MMR cutoff value of 0.712 obtained using the receiver operating characteristic (ROC) curve, patients were divided into two groups (69 and 83 patients in the MMR-L and MMR-H groups). The MMR-L group had a significantly higher total complication rate compared to the MMR-H group (MMR-L, 24.6% vs. MMR-H, 7.2%; P = 0.005). Multivariate analysis also identified MMR-L as a significant independent risk factor for total complications and intra-abdominal infectious complications after MIDG. CONCLUSIONS: The MMR calculated using bioelectrical impedance analysis can be a useful predictor for postoperative complications after MIDG in male GC patients.

Efficacy of minimally invasive proximal gastrectomy followed by valvuloplastic esophagogastrostomy using the double flap technique in preventing reflux oesophagitis.

BACKGROUND: Valvuloplastic esophagogastrostomy (VEG) using the double flap technique (DFT) after proximal gastrectomy (PG) represents a promising procedure for the prevention of reflux oesophagitis. We aimed to retrospectively investigate the efficacy of minimally invasive PG followed by VEG-DFT in preventing reflux oesophagitis among patients who require intra-mediastinal anastomosis. METHODS: A total of 80 patients who underwent reconstruction with DFT after LPG from November 2013 to January 2021 were enrolled in the present study. Data were obtained through a review of our prospectively maintained database. At 1 year after surgery, multivariate analyses were performed to identify risk factors for gastroesophageal reflux disease of Los Angeles (LA) classification grade B or higher. RESULTS: The incidence of LA grade B or higher reflux oesophagitis 1 year after surgery was 10%. Multivariate analyses revealed that the longitudinal length of the resected oesophagus of > 20 mm was the only significant risk factor for reflux oesophagitis. Patients with a longitudinal length of the resected oesophagus > 20 mm (group-L, n = 35) had a significantly longer total operative time and a higher rate of complications within 30 days of surgery than those with a length of ≤ 20 mm (group-S, n = 45). LA grade B or higher reflux oesophagitis was significantly higher in group-L than in group-S (20% vs. 2.2%; P = 0.011). CONCLUSIONS: There is a need for surgical procedures with improved efficacy for the prevention of reflux oesophagitis in patients requiring oesophageal resection of > 20-mm.

Three-year outcomes of robotic gastrectomy versus laparoscopic gastrectomy for the treatment of clinical stage I/II gastric cancer: a multi-institutional retrospective comparative study.

BACKGROUND: Oncological benefits of robotic gastrectomy (RG) remain unclear. We aimed to determine and compare the 3-year outcomes of RG and laparoscopic gastrectomy (LG) for the treatment of gastric cancer. METHODS: This was a multi-institutional retrospective study of patients who prospectively underwent RG in a previous study (UMIN000015388) and historical controls who underwent LG. Operable patients with cStage I/II primary gastric cancer were enrolled. The inverse probability of treatment weighting method based on propensity scores was used to balance patient demographic factors and surgeon volume between the RG and LG groups. The primary outcome measure was the 3-year overall survival rate (3yOS). RESULTS: Of the 1,127 patients in the previous study, 326 and 752 patients in the RG and LG groups, respectively, completed the study. The standardized difference of all confounding factors was reduced to 0.09 or less after weighting. In the weighted population, 3yOS was 96.3% and 89.6% in the RG and LG groups, respectively (hazard ratio [HR] 0.34 [0.15, 0.76]; p = 0.009), whereas there was no difference in 3-year recurrence-free survival rate (3yRFS) between the two groups (HR 0.58 [0.32, 1.05]; p = 0.073). Sub-analyses showed that RG improved 3yOS (HR 0.05 [0.01, 0.38]; p = 0.004) and 3yRFS (HR 0.05 [0.01, 0.34]; p = 0.003) in patients with pStage IA disease. Recurrence rates and patterns were similar between the RG and LG groups. RG did not improve the morbidity rate, however, it attenuated some of the adverse events, including anastomotic leakage and intra-abdominal abscess. RG improved estimated blood loss and duration of postoperative hospitalization. CONCLUSION: This study showed surgical and oncological safety of RG for cStage I/II gastric cancer considering the 3-year outcomes, compared with those of LG.

Incidence and clinical relevance of postoperative diarrhea after minimally invasive gastrectomy for gastric cancer: a single institution retrospective study of 1476 patients.

PURPOSE: Postoperative diarrhea (PD) remains one of the significant complications. Only a few studies focused on PD after minimally invasive surgery. We aimed to investigate PD after minimally invasive gastrectomy for gastric cancer. METHODS: A total of 1476 consecutive patients with gastric cancer undergoing laparoscopic or robotic gastrectomy between 2009 and 2019 at our institution were retrospectively reviewed. PD was defined as continuous diarrhea for ≥ 2 days, positive stool culture, or positive clostridial antigen test. The incidence, causes, and related clinical factors were analyzed. RESULTS: Of the 1476 patients, the median age was 69 years. Laparoscopic and robotic approaches were performed in 1072 (72.6%) and 404 (27.4%), respectively. Postoperative complications with Clavien-Dindo classification grade of ≥ IIIa occurred in 108 (7.4%) patients. PD occurred in 89 (6.0%) patients. Of the 89 patients with PD, Clostridium difficile, enteropathogenic Escherichia coli, and methicillin-resistant Staphylococcus aureus were detected in 24 (27.0%), 16 (33.3%), and 7 (14.6%) patients, respectively. Multivariate analysis revealed that age ≥ 75 years (OR 1.62, 95% CI [1.02-2.60], p = 0.042) and postoperative complications (OR 6.04, 95% CI [3.54-10.32], p < 0.001) were independent risk factors for PD. In patients without complications, TG (OR 1.88) and age of ≥ 75 years(OR 1.71) were determined as independent risk factors. CONCLUSION: The incidence of PD following minimally invasive gastrectomy for gastric cancer was 6.0%. Older age and TG were obvious risk factors in such a surgery, with the latter being a significant risk even in the absence of complications.

Safe implementation of robotic distal gastrectomy performed by non-endoscopic surgical skill qualification system-qualified surgeons.

PURPOSE: Robotic gastrectomy (RG) for gastric cancer (GC) was approved for national medical insurance coverage in April, 2018, since when its use has increased dramatically throughout Japan. However, the safety of RG performed by surgeons who are not Endoscopic Surgical Skill Qualification System (ESSQS)-qualified has yet to be established. We conducted this study to verify the short-term outcomes of the initial series of RG procedures performed by non-ESSQS-qualified surgeons. METHODS: Between January, 2020 and December, 2021, 30 patients with clinical Stage I and II GC underwent RG performed by four non-ESSQS-qualified surgeons according to the Japan Society for Endoscopic Surgery guideline. We evaluated, retrospectively, the morbidity rates according to Clavien-Dindo (CD) classification grade II or higher. RESULTS: Each operating surgeon completed all procedures without any serious intraoperative adverse events. The median operative time, console time, and estimated blood loss were 413 (308-547) min, 361 (264-482) min, and 25.5 (4-167) mL, respectively. No patient required conversion to laparoscopic or open surgery. Three (10%) patients suffered CD grade II complications postoperatively. The median postoperative hospitalization was 11 (8-51) days. CONCLUSION: Non-ESSQS-qualified surgeons trained by expert RG surgeons could perform robotic distal gastrectomy safely for initial cases.

Circular-stapled esophagogastrostomy using the keyhole procedure after radical esophagectomy for esophageal cancer.

BACKGROUND: Anastomotic leakage of cervical esophagogastrostomy following radical esophagectomy for esophageal cancer has reduced over time; however, postoperative anastomotic stricture still occurs at a considerably high rate. We developed a novel method of circular-stapled esophagogastrostomy by employing the keyhole procedure, which uses a linear stapler to enlarge the anastomotic opening made with a circular stapler (CS). METHODS: We retrospectively reviewed 70 patients with esophageal cancer who underwent transthoracic esophagectomy and reconstruction via cervical CS-mediated anastomosis with or without the keyhole procedure between 2018 and 2020. The primary outcome was postoperative anastomotic stricture incidence within 180 days after surgery. RESULTS: Among 70 patients, 22 underwent the keyhole procedure (CS + K group) and the remaining did not (CS group). No differences were observed in patients' age, sex, body mass index, performance status, American Society of Anesthesiologists physical status, Charlson's comorbidity index, tumor histological type, tumor location, clinical stage, or preoperative treatment. A smaller stapler was used in the CS + K group (p < 0.001). Incidence of anastomotic stricture was significantly different (CS vs. CS + K, 18.8 vs. 0%, p = 0.049), especially when a 21 or 23 mm CS was used (CS vs. CS + K, 50.0 vs. 0%, p = 0.005). Univariate analysis confirmed that CS ≤ 23 without keyhole was a significant risk factor (p = 0.001). CONCLUSIONS: The keyhole procedure could be a simple and useful alternative technique that reduces the risk of stricture formation in cervical esophagogastric anastomosis, especially when using the smaller-sized CS.

Early Elevation of Cell-Free DNA After Acute Mesenteric Ischemia in Rats.

BACKGROUND: Acute mesenteric ischemia (AMI) is challenging to diagnose in the early phase. We tested the hypothesis that blood levels of cell-free DNA would increase early after AMI. In addition, proteome analysis was conducted as an exploratory analysis to identify other potential diagnostic biomarkers. METHODS: Mesenteric ischemia, abdominal sepsis, and sham model were compared in Sprague-Dawley rats. The abdominal sepsis model was induced by cecum puncture and mesenteric ischemia model by ligation of the superior mesenteric artery. Blood levels of cell-free DNA were measured 2 h and 6 h after wound closure. Shotgun proteome analysis was performed using plasma samples obtained at the 2 h timepoint; quantitative analysis was conducted for proteins detected exclusively in the AMI models. RESULTS: Blood cell-free DNA levels at 2 h after wound closure were significantly higher in the AMI model than in the sham and the abdominal sepsis models (P < 0.05). Cell-free DNA was positively correlated with the pathologic ischemia severity score (correlation coefficient 0.793-0.834, P < 0.001). Derivative proteome analysis in blood at 2-h time point revealed higher intensity of paraoxonase-1 in the AMI models than in the abdominal sepsis models; the significantly high blood paraoxonase-1 levels in the AMI models were confirmed in a separate quantitative analysis (P = 0.015). CONCLUSIONS: Cell-free DNA was demonstrated to be a promising biomarker for the early diagnosis of mesenteric ischemia in a rat model of AMI. Paraoxonase-1 may also play a role in the differential diagnosis of mesenteric ischemia from abdominal sepsis. The current results warrant further investigation in human studies.

Clinical advantage of standardized robotic total gastrectomy for gastric cancer: a single-center retrospective cohort study using propensity-score matching analysis.

BACKGROUND: Although recent studies have shown that robotic gastrectomy offers clinical advantages over laparoscopic gastrectomy in decreasing gastric cancer (GC) morbidity, studies focusing on robotic total gastrectomy (RTG) remain limited. The current study aimed to clarify whether the use of a robotic system could clinically improve short-term outcomes. METHODS: Between January 2009 and June 2021, 371 patients diagnosed with both clinical and pathological Stage III or lower GC and underwent RTG or laparoscopic total gastrectomy (LTG) were enrolled in this study. The primary outcome was the incidence of intra-abdominal infectious complications over Clavien-Dindo classification grade IIIa. Demographic characteristics of those who underwent the RTG and LTG were matched using propensity-score matching (PSM), after which short-term outcomes were compared retrospectively. RESULTS: After PSM, 100 patients were included in each group. The RTG group had a significantly shorter duration of hospitalization following surgery [RTG 13 (11-16) days vs. LTG 14 (11-19) days; p = 0.032] and a greater number of dissected LNs [RTG 48 (39-59) vs. LTG 43 (35-54) mL; p = 0.025], despite having a greater total operative time [RTG 511 (450-646) min vs. LTG 448 (387-549) min; p < 0.001]. In addition, the RTG group had significantly fewer total complications (3% vs. 13%, p = 0.019) and intra-abdominal infectious complications (1% vs. 9%; p = 0.023). CONCLUSIONS: The current study showed that robotic surgery might improve short-term outcomes following minimally invasive radical total gastrectomy by reducing intra-abdominal infectious complications.

Safe implementation of robotic gastrectomy for gastric cancer under the requirements for universal health insurance coverage: a retrospective cohort study using a nationwide registry database in Japan.

BACKGROUND: Robotic gastrectomy (RG) has increased since being covered by universal health insurance in 2018. However, to ensure patient safety the operating surgeon and facility must meet specific requirements. We aimed to determine whether RG has been safely implemented under the requirements for universal health insurance in Japan. METHODS: Data of consecutive patients with primary gastric cancer who underwent minimally invasive total or distal gastrectomy-performed by a surgeon certified by the Japan Society for Endoscopic Surgery (JSES) endoscopic surgical skill qualification system (ESSQS) between October 2018 and December 2019-were extracted from the gastrointestinal surgery section of the National Clinical Database (NCD). The primary outcome was morbidity over Clavien-Dindo classification grade IIIa. Patient demographics and hospital volume were matched between RG and laparoscopic gastrectomy (LG) using propensity score-matched analysis (PSM), and the short-term outcomes of RG and LG were compared. RESULTS: After PSM, 2671 patients who underwent RG and 2671 who underwent LG were retrieved (from a total of 9881), and the standardized difference of all the confounding factors reduced to 0.07 or less. Morbidity rates did not differ between the RG and LG patients (RG, 4.9% vs. LG, 3.9%; p = 0.084). No difference was observed in 30-day mortality (RG, 0.2% vs. LG, 0.1%; p = 0.754). The reoperation rate was greater following RG (RG, 2.2% vs. LG, 1.2%; p = 0.004); however, the duration of postoperative hospitalization was shorter (RG, 10 [8-13] days vs. LG, 11 [9-14] days; p < 0.001). CONCLUSIONS: Insurance-covered RG has been safely implemented nationwide.