Clinical Evaluation of Computer-Aided Colorectal Neoplasia Detection Using a Novel Endoscopic Artificial Intelligence: A Single-Center Randomized Controlled Trial.

INTRODUCTION: Computer-aided diagnostic systems are emerging in the field of gastrointestinal endoscopy. In this study, we assessed the clinical performance of the computer-aided detection (CADe) of colonic adenomas using a new endoscopic artificial intelligence system. METHODS: This was a single-center prospective randomized study including 415 participants allocated into the CADe group (n = 207) and control group (n = 208). All endoscopic examinations were performed by experienced endoscopists. The performance of the CADe was assessed based on the adenoma detection rate (ADR). Additionally, we compared the adenoma miss rate for the rectosigmoid colon (AMRrs) between the groups. RESULTS: The basic demographic and procedural characteristics of the CADe and control groups were as follows: mean age, 54.9 and 55.9 years; male sex, 73.9% and 69.7% of participants; and mean withdrawal time, 411.8 and 399.0 s, respectively. The ADR was 59.4% in the CADe group and 47.6% in the control group (p = 0.018). The AMRrs was 11.9% in the CADe group and 26.0% in the control group (p = 0.037). CONCLUSION: The colonoscopy with the CADe system yielded an 11.8% higher ADR than that performed by experienced endoscopists alone. Moreover, there was no need to extend the examination time or request the assistance of additional medical staff to achieve this improved effectiveness. We believe that the novel CADe system can lead to considerable advances in colorectal cancer diagnosis.

Metformin changes the immune microenvironment of colorectal cancer in patients with type 2 diabetes mellitus.

Accumulating evidence suggests that metformin reduces the incidence and mortality of colorectal cancer (CRC). However, underlying mechanisms have not been fully clarified. The aim of this study was to examine the pathological characteristics of resected CRC from patients treated with metformin for type 2 diabetes mellitus (DM). In total, 267 patients with DM underwent curative colectomy for Stage I-III CRC and 53 (19.9%) patients had been treated medically including metformin. Pathological N-stage was significantly lower in metformin-treated patients (P < .05) with prolonged disease-free survival (DFS) (P < .05). Immunohistochemistry showed that the densities of CD3(+) and CD8(+) tumor-infiltrating lymphocytes (TILs) in the invasive front area were significantly higher in 40 patients treated with metformin compared with propensity score matched cases without metformin (P < .05). The density of tertiary lymphoid structures (TLS) in tumor stroma was markedly increased in metformin-treated patients (P < .001). In those tumors, there were more CD68(+) tumor-associated macrophages (TAM) infiltrated (P < .05), while the ratio of CD163(+) M2-phenotype was markedly reduced (P < .001). Stromal fibrosis tended to be suppressed by metformin intake (P = .051). These findings suggested that metformin drastically changes the characteristics of infiltrating immune cells in CRC and reprograms the tumor microenvironment from immunosuppressive to immunocompetent status, which may lead to suppression of microscopic tumor spread and improve the outcomes of patients with CRC and type 2 DM.

Endoscopic three-categorical diagnosis of Helicobacter pylori infection using linked color imaging and deep learning: a single-center prospective study (with video).

BACKGROUND: Helicobacter pylori (H. pylori) eradication is required to reduce incidence related to gastric cancer. Recently, it was found that even after the successful eradication of H. pylori, an increased, i.e., moderate, risk of gastric cancer persists in patients with advanced mucosal atrophy and/or intestinal metaplasia. This study aimed to develop a computer-aided diagnosis (CAD) system to classify the status of H. pylori infection of patients into three categories: uninfected (with no history of H. pylori infection), currently infected, and post-eradication. METHODS: The CAD system was based on linked color imaging (LCI) combined with deep learning (DL). First, a validation dataset was formed for the CAD systems by recording endoscopic movies of 120 subjects. Next, a training dataset of 395 subjects was prepared to enable DL. All endoscopic examinations were recorded using both LCI and white-light imaging (WLI). These endoscopic data were used to develop two different CAD systems, one for LCI (LCI-CAD) and one for WLI (WLI-CAD) images. RESULTS: The diagnostic accuracy of the LCI-CAD system was 84.2% for uninfected, 82.5% for currently infected, and 79.2% for post-eradication status. Comparisons revealed superior accuracy of diagnoses based on LCI-CAD data relative based on WLI-CAD for uninfected, currently infected, and post-eradication cases. Furthermore, the LCI-CAD system demonstrated comparable diagnostic accuracy to that of experienced endoscopists with the validation data set of LCI. CONCLUSIONS: The results of this study suggest the feasibility of an innovative gastric cancer screening program to determine cancer risk in individual subjects based on LCI-CAD.

Endoscopic Diagnostic Support System for cT1b Colorectal Cancer Using Deep Learning.

OBJECTIVE: This study aimed to use convolutional neural network (CNN), a deep learning software, to assist in cT1b diagnosis. METHODS: This retrospective study used 190 colon lesion images from 41 cases of colon endoscopies performed between February 2015 and October 2016. Unenhanced colon endoscopy images (520 × 520 pixels) with white light were used. Images included 14 cTis cases with endoscopic resection and 14 cT1a and 13 cT1b cases with surgical resection. Protruding, flat, and recessed lesions were analyzed. AlexNet and Caffe were used for machine learning. Fine tuning of data to increase image numbers was performed. Oversampling for the training images was conducted to avoid impartiality in image numbers, and learning was carried out. The 3-fold cross-validation method was used. Sensitivity, specificity, accuracy, and area under the curve (AUC) values in the receiver operating characteristic curve were calculated for each group. RESULTS: The results were the average of obtained values. With CNN learning, cT1b sensitivity, specificity, and accuracy were 67.5, 89.0, and 81.2%, respectively, and AUC was 0.871. CONCLUSION: Quantitative diagnosis is possible using an endoscopic diagnostic support system with machine learning, without relying on the skill and experience of endoscopists. Moreover, this system could be used to objectively evaluate endoscopic diagnoses.

A standing posture support device that reduces laparoscopic surgeons' occupational lower limb stress.

BACKGROUND: We developed a surgical knee rest (SKR) that can be used to decrease the stress placed on the lower half of the body when surgeons work in the standing position. We tested the effectiveness of this device in the context of laparoscopic surgery. MATERIAL AND METHODS: Five healthy, right-handed male surgeons participated, and we recorded surface electromyography (sEMG) signals from the two heads of the left and right gastrocnemius (Gc) muscles during laparoscopic resections of colorectal cancer. The outcome variable was the percentage of maximum Gc muscle effort generated, reported as percent maximal isometric voluntary contraction (%MVC), and this variable was compared between surgeries performed with and without use of the SKR. Assessment covered the first 100 min of surgery, subdivided into two 50-min periods. RESULTS: Mean %MVC of the left Gc muscle for the full 100-min test period was significantly decreased when the SKR was used (p = .027, vs. SKR not used). Notably, mean %MVC of both Gc muscles was significantly decreased during the first 50 min of surgery (p = .008 and p = .0046). CONCLUSION: The SKR is useful for decreasing physical stress incurred by laparoscopic surgeons when working in the standing position.

Laparoscopic and luminal endoscopic cooperative surgery can be a standard treatment for submucosal tumors of the stomach: a retrospective multicenter study.

Background and study aims We have developed a combined laparoscopic and luminal endoscopic surgery technique for resection of gastric submucosal tumors (SMTs) that can be performed without excessive resection of the stomach. In a multicenter retrospective study we aimed to evaluate the feasibility and safety of laparoscopic and endoscopic cooperative surgery (LECS) for gastric SMT resection. Patients and methods Between October 2007 and December 2011, 126 patients with gastric SMTs underwent LECS at 8 institutions. Patient demographics, tumor histopathologic characteristics, and operative and follow-up data were reviewed. Results 16 tumors (12.7 %) were located in the upper third of the stomach, 88 (69.8 %) in the middle third, 5 (4.0 %) in the lower third, and 17 (13.5 %) at the esophagogastric junction. The mean (standard deviation [SD]) operation time for LECS was 190.2 (66.8) min, with a mean estimated blood loss of 15.1 (38.6) mL. In 2 cases (1.6 %), the procedure was converted to open surgery because of intra-abdominal adhesions or stenosis. Morbidity was found in 6 cases (4.8 %), including 2 leakage, 2 gastric stasis, 1 fever, and 1 cystitis. Histologically, a gastrointestinal stromal tumor (GIST) was found in 86 (68.3 %) cases. The median follow-up period was 54.7 months; no local or distant tumor recurrence was observed and all patients were alive. Conclusions LECS proved to be a safe and feasible procedure for the resection of gastric SMTs, with a reasonable operation time, low bleeding, and an acceptable complication rate in this multicenter study in Japan.

Gastric Resection Under Retroflexed Endoscopic Guidance: A Reliable Procedure for Totally Laparoscopic Subtotal Gastrectomy.

BACKGROUND/AIMS: Totally laparoscopic distal gastrectomy (TLDG) has become a feasible and safe surgical option for early gastric cancer. However, determining the transection line of the stomach without palpation is still difficult. This study aimed to assess the efficacy of TLDG for gastric resection under retroflexed endoscopic guidance (GRREG) in patients with gastric cancer in the middle third of the stomach. METHODS: Fifteen patients with gastric cancer underwent TLDG using GRREG. Preoperative tumor localization using endoscopic metal clips was performed in all cases. After lymphadenectomy, two-thirds of the estimated transection line was occluded by an endoscopic stapler, beginning at the lesser curvature. Under gastric occlusion, the gastroscope was passed via the narrow lumen along the greater curvature followed by retroflexion to reveal the occlusion line, marking clips, and tumor in the same field of view. This view verified the safe oncological transection line. RESULTS: All patients had cancer-free margins and did not require additional surgery. The mean (±SD) proximal margin was 23.5 ± 10.4 mm. There were no procedure-related complications. CONCLUSIONS: GRREG was a safe and effective technique for TLDG. Ideal transection of the stomach was achieved using a combination of an endoscopic stapler and gastroscope retroflexion.

Specific Features of Dumping Syndrome after Various Types of Gastrectomy as Assessed by a Newly Developed Integrated Questionnaire, the PGSAS-45.

AIM: Dumping syndrome is a well-known adverse outcome after gastrectomy, but the precise clinical features have not been described. The aim of this study was to examine global aspects of dumping syndrome and to explore factors affecting the intensity of dumping syndrome in a large cohort using a newly developed integrated questionnaire, the Post-Gastrectomy Syndrome Assessment Scale (PGSAS)-45. METHODS: Eligible questionnaires retrieved from 2,368 patients after 6 types of gastrectomy were analyzed. The incidence, intensity and number of symptoms of early general, early abdominal and late dumping syndrome were examined across various types of gastrectomy, and clinical factors affecting the intensity of each category of dumping syndrome were identified by multiple regression analysis. RESULTS: Dumping syndromes occurred most frequently and strongly in patients who underwent total gastrectomy with Roux-en-Y (TGRY), followed by proximal gastrectomy (PG), distal gastrectomy with Billroth-I, distal gastrectomy with Roux-en-Y, pylorus-preserving gastrectomy (PPG) and local resection (LR), in that order. Significant positive correlations among different categories of dumping syndromes were observed. TGRY, female sex, younger age, division of the celiac branch of the vagus nerve, PG and shorter postoperative period were independently related to worse dumping syndrome. CONCLUSIONS: Dumping syndromes were most common after TGRY and least common after PPG and LR among the various gastrectomy procedures. Type of gastrectomy and several clinical factors were related to the intensity of dumping syndrome. PGSAS-45 could offer a useful tool for evaluating dumping syndrome after gastrectomy.

Eradication of esophageal varices by sclerotherapy combined with argon plasma coagulation: Effect of portal hemodynamics and longitudinal clinical course.

BACKGROUND AND AIM: To demonstrate the effect of endoscopic injection sclerotherapy (EIS) with argon plasma coagulation (APC) as a primary/secondary prophylaxis for esophageal varies (EV) on portal hemodynamics and long-term outcomes in cirrhosis. METHODS: This prospective study included 48 cirrhotic patients (64.5 ± 11.4 years; 26 bleeders, 22 non-bleeders). Post-treatment outcomes (EIS and APC; median observation period, 12.8 months for recurrence and 21.1 months for prognosis) were evaluated with respect to the findings of hepatic venous catheterization, Doppler ultrasound, and endoscopic ultrasonography (EUS). RESULTS: All patients showed EV eradication after endoscopic treatment, and a decreased frequency of a patent left gastric vein (pre: 83.3%, post: 27.1%, P < 0.001). However, hepatic venous pressure gradient (HVPG, mmHg) remained unchanged after the treatment, pre: 16.1 ± 3.6, post: 15.6 ± 3.8 (P = 0.269). Cumulative variceal recurrence/rebleeding rates were 25.5%/5.6% and 62.4%/23.1% at 1 and 3 years, respectively. Post-treatment EUS finding, area of submucosal vessels in the cardia ≥12 mm2 was the only significant factor for variceal recurrence (hazard ratio 9.769, 95% confidence interval 3.046-31.337; P < 0.001). Cumulative recurrence rate was significantly higher in patients with area of submucosal vessels in the cardia ≥12 mm2 (58.3% at 1 year and 100% at 3 years) than in those without (11.4% at 1 year and 40.9% at 3 years, P < 0.001). Cumulative overall survival rates were 95.2% and 71.9% at 1 and 3 years, respectively, showing no significant relationship with HVPG. CONCLUSION: EIS with APC for EV is unlikely to have a significant influence on portal pressure.

Ergonomic design and evaluation of the handle for an endoscopic dissector.

The purpose of this study was to design an endoscopic dissector handle and objectively assess its usability. The handles were designed with increased contact area between the fingers and thumb and the eye rings, and the eye rings were modified to have a more perpendicular insertion angle to the finger midline. Four different handle models were compared, including a conventional product. Subjects performed dissection, exclusion, grasping, precision manipulation and precision handling tasks. Electromyography and subjective evaluations were measured. Compared to conventional handles, the designated handle reduced the muscle load in the extensor and flexor muscles of the forearm and increased subjective stability. The activity of the first dorsal interosseous muscle was sometimes influenced by the shape of the other parts. The ergonomically designed endoscopic dissector handle used in this study achieved high usability. Medical instrument designs based on ergonomic concepts should be assessed with objective indices. Practitioner Summary: The endoscopic dissector handles were designed with increased contact area and more suitable insertion angle between the fingers and thumb and the eye rings. Compared to conventional handles, the designated handle reduced the muscle load in the extensor and flexor muscles of the forearm and increased subjective stability.

Factors that minimize postgastrectomy symptoms following pylorus-preserving gastrectomy: assessment using a newly developed scale (PGSAS-45).

BACKGROUND: Pylorus-preserving gastrectomy (PPG) is sometimes performed as a function-preserving surgery for the treatment of early gastric cancer. The aim of this study was to use an integrated assessment scale for postgastrectomy syndrome to determine the appropriate indicators and optimal methods for PPG. METHODS: The Postgastrectomy Syndrome Assessment Study (PGSAS) is a multicenter survey based on an integrated questionnaire (PGSAS-45) consisting of 45 items. Questionnaire responses were retrieved from a total of 2,520 patients, each of whom had undergone one of six different types of gastrectomy procedures; 313 responses from patients who had received PPG were analyzed here. RESULTS: The size of the proximal gastric remnant (less than one-quarter, about one-third, or more than one-half of the original size) significantly influenced the change in body weight, the scores for dissatisfaction at the meal, and dissatisfaction for daily life subscale (P = 0.030, P = 0.005, P = 0.034, respectively). The nausea score in patients who underwent hand-sewn anastomosis was significantly lower than in those who underwent anastomosis with a linear stapler (P = 0.006). The scores for diarrhea subscale, increased passage of stools, and sense of foods sticking differed significantly depending on the length of the preserved pyloric cuff (P = 0.047, P = 0.021, P = 0.046, respectively). CONCLUSIONS: The results suggest that preservation of a sufficient proximal gastric remnant is recommended when utilizing PPG as function-preserving surgery.

Synthetic polyglycomer short-term absorbable sutures vs. polydioxanone long-term absorbable sutures for preventing incisional hernia and wound dehiscence after abdominal wall closure: a comparative randomized study of patients treated for gastric or colon cancer.

PURPOSE: To compare the results of abdominal wall closure using interrupted synthetic short-term vs. long-term tensile strength-retaining absorbable sutures. METHODS: The subjects were 55 patients undergoing elective laparotomy through a midline vertical incision for gastric or colon cancer surgery between November 2008 and August 2010, at our hospital. After providing informed consent, the patients were randomized for suturing with Polysorb(®), which provides short-term tensile strength, or with PDS(®)II, which provides long-term strength. The primary outcome analyzed was the incidence of incisional hernia or wound dehiscence. RESULT: There were 28 patients allocated to the Polysorb group and 27 to the PDS II group. Postoperative wound dehiscence was noted in two patients (3.6%). Five of 51 patients (9.8%) suffered incisional hernia within 1 year after surgery, 6 of 41 patients (14.6%) within 2 years, and 6 of 35 patients (17.1%) within 3 years. There was no significant per year difference in the incidence of incisional hernia or wound dehiscence between the groups. CONCLUSION: Outcomes were favorable in both groups and not inferior to reported outcomes of larger-scale studies. Verification of the equivalence between the two types of suture material necessitates larger-scale studies that adopt the same suture methods.

Optimal Roux-en-Y reconstruction after distal gastrectomy for early gastric cancer as assessed using the newly developed PGSAS-45 scale.

PURPOSE: The optimal surgical procedure for distal gastrectomy with Roux-en-Y reconstruction (DGRY) remains to be determined. Recently, a self-report assessment instrument, the Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45), was compiled to evaluate symptoms, the living status and the quality of life of patients who have undergone gastrectomy. We used this scale to evaluate procedures used for DGRY. METHODS: The subjects included 475 patients who underwent DGRY for stage IA/IB gastric cancer. We evaluated whether the size of the remnant stomach, length of the Roux limb, reconstruction route and anastomotic procedure affected the patients' symptoms, living status and quality of life assessed using the PGSAS-45. RESULTS: Patients with a residual stomach of more than half had significantly worse esophageal reflux scores than the patients with a smaller residual stomach (P = 0.0462); a residual stomach of one-third or one-fourth was favorable. A shorter length of the Roux limb was shown to be preferable to a longer Roux limb based on the results of the PGSAS-45. In addition, antecolic reconstruction and the anastomotic procedure using a linear stapler were found to be more favorable. CONCLUSIONS: The size of the remnant stomach and the length and route of the Roux limb significantly influence the patient-reported DGRY outcomes.

Postgastrectomy Syndrome Assessment Scale (PGSAS)-45 and changes in body weight are useful tools for evaluation of reconstruction methods following distal gastrectomy.

BACKGROUND: Billroth-I (BI) and Roux-en-Y (RY) are well-known reconstruction methods that are conducted following distal gastrectomy. However, the relative merits of these 2 methods are not well documented. The newly developed Postgastrectomy Syndrome Assessment Scale (PGSAS)-45 is an integrated questionnaire consisting of 45 items, including 8 items from the 8-Item Short-Form Health Survey (SF-8), 15 items from the Gastrointestinal Symptom Rating Scale, and 22 items selected by gastric surgeons. Postoperative QOL ratings were evaluated for each reconstruction method using PGSAS-45. METHODS: The PGSAS-45 questionnaire was distributed to 2,922 patients who underwent gastrectomies at 52 medical institutions. Among the questionnaires distributed, 2520 (86 %) were retrieved and 2368 (81 %) met eligibility requirements. Statistical analyses were conducted to compare 1,384 of the eligible questionnaires, including responses from patients who underwent BI (n = 909) and RY (n = 475) procedures. RESULTS: BI procedures were associated with significantly longer postoperative periods, a significantly greater size of gastric remnants, and a higher frequency of laparoscopic approaches and celiac branch preservation. Postoperative QOL analysis indicated that BI procedures resulted in significantly lower postoperative weight loss and significantly higher esophageal reflux symptoms than RY procedures. There was no significant difference between the two groups on other outcome measures. CONCLUSIONS: Although weight loss was significantly lower following BI procedures, esophageal reflux symptoms were significantly higher. Either BI or RY procedures may be recommended based on the individual patient's condition after distal gastrectomy. The newly developed QOL questionnaire, PGSAS-45 and changes in body weight proved useful for evaluation of QOL following gastrectomy.

Evaluation of Scissor Glide Characteristics Through Surgeons' Subjective Assessment: The Application of Nitriding in Scissor Hardening Tests.

INTRODUCTION: In robotic surgery, studies on providing tactile feedback to users are ongoing. However, the accuracy of the subjective sensations of surgeons, as users, has been largely unassessed. This study aimed to assess the validity of surgeons' subjective evaluations of scissors resistance through interindividual, inter-surgeon, and objective evaluations. Furthermore, in this study, we explored the possibility of using nitriding to increase the hardness of the scissors and assessed changes in subjective resistance values before and after nitriding using this approach. METHOD: Five surgeons conducted validation of five curved surgical scissors (145 mm; Arakawa Seisakujyo Co., Ltd., Tokyo, Japan) and assessed their subjective resistance using a scale from 0 to 10, where a rating of 10 signified significant resistance impeding the scissors' closure. The temporal changes in subjective resistance values, from maximum open to close, were graphically recorded. To demonstrate the reproducibility of subjective resistance values, the subjective resistance values of the same control scissors were measured at intervals of at least two weeks, and the correlation coefficient was calculated. To analyze the closing characteristics of subjective resistance values between different pairs of scissors, the effect of scissor type and scissor closure position was compared as two independent variables using a two-factor analysis of variance. A comparative evaluation was conducted to assess the frictional properties of scissors after nitriding, comparing the subjective assessment by surgeons with the objective assessment using a digital force gauge. RESULTS: The correlation coefficient of subjective resistance values measured by surgeons demonstrated a high reproducibility of 0.746. A two-factor analysis of variance conducted on subjective resistance values demonstrated the presence of a primary effect for the sample factor (scissors), as well as for the position factor (closing process), with the additional observation of the interaction between these two factors. The results from the two-factor analysis of variance above provide evidence supporting the validity of the subjective resistance measurements. There was a significant increase in subjective resistance after the nitriding process. The graph of subjective resistance values and objective resistance values showed similarity. CONCLUSIONS: The surgeons' subjective assessment of scissors resistance showed high reproducibility and validity, as evidenced by distinguishable differences in scissor movement interactions and pre- and post-nitriding resistance. Further studies are warranted to expand on these findings.

Laparoscopic distal gastrectomy skill evaluation from video: a new artificial intelligence-based instrument identification system.

The advent of Artificial Intelligence (AI)-based object detection technology has made identification of position coordinates of surgical instruments from videos possible. This study aimed to find kinematic differences by surgical skill level. An AI algorithm was developed to identify X and Y coordinates of surgical instrument tips accurately from video. Kinematic analysis including fluctuation analysis was performed on 18 laparoscopic distal gastrectomy videos from three expert and three novice surgeons (3 videos/surgeon, 11.6 h, 1,254,010 frames). Analysis showed the expert surgeon cohort moved more efficiently and regularly, with significantly less operation time and total travel distance. Instrument tip movement did not differ in velocity, acceleration, or jerk between skill levels. The evaluation index of fluctuation ß was significantly higher in experts. ROC curve cutoff value at 1.4 determined sensitivity and specificity of 77.8% for experts and novices. Despite the small sample, this study suggests AI-based object detection with fluctuation analysis is promising because skill evaluation can be calculated in real time with potential for peri-operational evaluation.

A Low Mean Closing Load and a Decrease in Load Change at the Tip Increase the Comfort of Scissors.

Introduction During surgery, surgeons intuitively recognize when they are using dull scissors and find them difficult to use. The purpose of this study was to objectively evaluate the physical characteristics of scissors and the comfort reported by surgeons to develop objective quality control standards for scissors used in surgery. Methods Sensory and measurement tests were conducted to evaluate the comfort and physical characteristics of ten pairs of Cooper scissors. As a sensory test, thirty-one volunteer surgeons opened and closed the scissors and selected three that felt comfortable and three that were uncomfortable. The results were scored. For measurement, a load was applied to the handle of the scissors. The load pressure and displacement of the width between each handle when the scissors were closed were measured. Results A strong negative correlation was found between the total comfort score and the mean load value between sensory and measurement tests (r=-0.717, p=0.0195). The correlation between the total score and the change in load at the tip showed a moderate negative correlation (r=-0.687, p=0.0282). Multiple regression analysis showed that the change in load at the tip was an independent factor affecting the total score. Conclusions Surgeons consider scissors with a low mean load required to close the scissors and a small change in load at the tip to be comfortable. The mean load on scissors and the change in load at the tip should be considered in the development of quality control standards for scissors used in surgery.

A flexible-arm liver retractor that provides an optimal surgical field without postoperative liver dysfunction.

BACKGROUND/AIMS: It is important to retract the lateral liver segment during laparoscopic gastrectomy to achieve an optimal surgical field. Few retractors cause transient liver dysfunction after surgery; therefore, for an easier and safer procedure, we devised a new liver retractor and implemented a trial clinical application. METHODOLOGY: The novel liver retractor comprises a metallic, flexible arm retractor attached to the operating table and an air compressor which pneumatically moves and fixes the retractor. It was inserted directly into the abdominal cavity just below the xiphisternum to retract the left lobe of the liver anterosuperiorly, thereby exposing the hiatus. Blood samples were collected from the patients on days 1, 3, and 7 after surgery to assess the levels of the liver enzymes AST and ALT. RESULTS: During laparoscopic gastrectomy, no liver damage was observed macroscopically. The surgical fields obtained were optimal and efficient for laparoscopic surgery. Notably, it was possible to retract the liver as often as needed. Further, none of the patients developed postoperative liver dysfunction. CONCLUSIONS: The novel flexible-arm retractor provided an optimal surgical field without inducing liver dysfunction.

The effect of refresher training on fact description in medical incident report writing in the Japanese language.

To maintain the effectiveness of the training (1st-Training Session: 1st-TS) to accurate describe facts in the medical incident reports (IRs) in Japanese, a refresher TS was designed and its effectiveness was examined. First, textual analysis showed that IRs' accuracy significantly decreased six months after the 1st-TS. Based on this result, the refresher TS was designed and conducted with 64 residents. To verify the refresher TS' effectiveness, IRs after the 1st-TS, six months later, and after the refresher TS were compared via text analysis. The results showed that the refresher TS restored the description rate of patient's background, safety check procedures, original work procedures, information on equipment used, reporter's actions, and post-incident response. The questionnaire was also administered and showed that the refresher TS contributed to residents' motivation to learn about IRs. In conclusion, the refresher TS contributed to sustaining the effect of the 1st-TS on accurately describing IRs.

Pancreas Ligation Device for Distal Pancreatectomy: An Ex Vivo Follow-Up Porcine Study.

Introduction Postoperative pancreatic fistula (POPF) is a critical complication occurring with a high incidence after distal pancreatectomy. To minimize the risk of POPF, we developed an innovative pancreas ligation device capable of closing the pancreatic stump without causing traumatic injury to the pancreatic duct and artery. We conducted an ex vivo follow-up study to compare the pressure resistance of the pancreas ligation device with that of a regular linear stapler. Materials and methods The pancreases were excised from 20 pigs and divided into two groups: ligation group (n = 10) and stapler group (n = 10). Distal pancreatectomy was performed, and the pancreatic stump was closed using either a pancreas ligation device or a regular linear stapler. The main pancreatic duct was cannulated with a 4-French catheter connected to a cannula and syringe filled with contrast medium. Using fluoroscopy detection, pressure resistance was defined as the maximum pressure without leakage from the pancreatic stump. Results No significant differences were found between the two groups regarding sex, age, body weight, or pancreatic thickness. In the ligation group, no leakage was observed at the stump in any pancreas. However, in the stapler group, six of 10 pancreases showed leakage at the staple line or into the parenchyma. Pressure resistance was significantly higher in the ligation group than in the stapler group (median: 42.8 vs. 34.3 mmHg, P = 0.023). Conclusions These findings suggest the effectiveness of a pancreas ligation device in reducing the incidence of POPF after distal pancreatectomy. Our ligation device is expected to be a useful alternative to a linear stapler for pancreatic stump closure.