Search

Objective According to consensus guidelines, eosinophilic esophagitis (EoE) is defined as a clinicopathological entity whose symptoms and histology must always be considered together. However, endoscopic findings typical of EoE are often seen in asymptomatic esophageal eosinophilia (aEE). We aimed to clarify the clinicopathological features of aEE. Methods We retrospectively compared cases of aEE and those of symptomatic EoE. Patients or Materials We reviewed 146 patients who underwent upper gastrointestinal endoscopy and were confirmed histopathologically to have esophageal eosinophil infiltration of at least 15 eosinophils per high-power field. They were divided into the aEE group (n=75) and the EoE group (n=71). Patients' clinicopathological findings were then collected and examined. Results The EoE group experienced dysphagia (47.9%), heartburn (40.8%), food impaction (40.8%), chest pain (16.9%), and other symptoms (8.5%). There was no significant difference between the two groups with regard to age, sex, current smoking status, or alcohol consumption. The aEE group had a significantly higher body mass index (p

Pharyngeal squamous cell carcinoma (PSCC) is associated with a high likelihood of metachronous carcinogenesis, which is known to have a poor prognosis. This study aimed to identify comprehensive risk evaluation indicators for metachronous carcinogenesis after endoscopic submucosal dissection (ESD) of superficial PSCC.The risk of metachronous carcinogenesis was evaluated in 144 patients with superficial PSCC (with no history of PSCC or esophageal squamous cell carcinoma) who underwent initial ESD from 2008 to 2020. Multiple lugol-voiding lesions (LVLs) in the background pharyngeal and esophageal epithelium were evaluated as endoscopic indicators. The hemoglobin, albumin, lymphocyte, and platelet (HALP) score was analyzed as a serum marker.The median follow-up period was 4.3 years. The coincidence rate for pharyngeal and esophageal LVL grade was 55%. The cumulative 3-year metachronous PSCC rate was 18.9%. The cumulative 3-year second metachronous PSCC rate was 43.9%. Forward stepwise multivariate Cox proportional hazards regression analysis identified pharyngeal LVL grade and a lower HALP score as significant independent predictors. Pharyngeal LVL grade was superior to esophageal LVL grade as a predictor of metachronous PSCC. A lower HALP score was significantly associated with younger age in forward stepwise multivariate logistic regression analysis.Patients with a history of superficial PSCC remain at risk for metachronous carcinogenesis over time, and long-term follow-up is imperative. Comprehensive evaluation of endoscopic features with a novel serum marker, namely, the HALP score, can help predict metachronous carcinogenesis.

Helicobacter pylori (H. pylori) is an important risk factor for gastric cancer and is a recognized carcinogen. Although eradication of H. pylori reduces the incidence of gastric cancer, cases can still occur after eradication therapy. A number of such cases have been reported, and their early clinicopathological characteristics are becoming clearer. Some reports mention that endoscopic diagnosis of gastric cancer may be difficult after eradication therapy, because the cancer is covered by non-cancerous epithelium. However, there are few reports on advanced gastric cancer after eradication therapy, and its characteristics remain poorly understood. In view of the predicted increase in frequency of advanced gastric cancer after eradication therapy in the near future, it is important to be aware of these cases. In this report, we describe three cases of advanced gastric cancer detected during routine follow-up after eradication.

Introduction: Few studies have focused on bleeding following endoscopic submucosal dissection (ESD) in surgically altered stomach. We aimed to reveal the bleeding risk in surgically altered stomach following ESD for early gastric cancer (EGC). Methods: We enrolled patients with ESD for EGC at 33 institutions between 2013 and 2016. In study 1, we evaluated bleeding risk following ESD in surgically altered stomach, compared with whole stomach. In study 2, we evaluated factors associated with bleeding following ESD in patients with surgically altered stomach. Results: Of 11,452 patients, 445 patients had surgically altered stomach with the bleeding rate following ESD of 4.9%. In study 1, the bleeding risk in surgically altered stomach was not significant (odds ratio [OR], 1.37; 95% confidence interval [CI], 0.87–2.17) in the multivariate logistic regression analysis. No significant results were obtained when the surgically altered stomach was subdivided into various types. In study 2, the multivariate logistic regression analysis revealed that independent risk factors for bleeding following ESD were ischemic heart disease (OR, 7.52; 95% CI, 2.00–28.25) and P2Y12 receptor antagonist (OR, 4.81; 95% CI, 1.21–19.14). Discussion/Conclusion: In this nationwide study, we found that the bleeding risk of surgically altered stomach following ESD for EGC did not significantly differ from that of whole stomach. The risk factors for ESD in patients with surgically altered stomach were ischemic heart disease and P2Y12 receptor antagonist.

Background Although almost all cases of gastric cancer are caused by Helicobacter pylori (HP) infection, there are some rare exceptions. Furthermore, the clinicopathological characteristics of gastric cancer may differ depending on HP infection status. This study aimed to determine the clinicopathological characteristics of undifferentiated-type gastric cancer (UD-GC) according to HP status. Methods The study involved 83 patients with UD-GC who were selected from 1559 patients with gastric cancer who underwent endoscopic resection at our hospital and whose HP infection status was confirmed. Clinicopathological characteristics were evaluated according to HP status (eradicated, n = 28; infected, n = 32; not infected, n = 23). Results In patients without HP infection, UD-GCs were Conclusion The clinicopathological characteristics of UD-GC were similar between HP-infected patients and HP-eradicated patients. Three of four patients with eradicated HP whose UD-GC developed ≥ 10 years after eradication were not eligible for endoscopic treatment and required additional surgery resection. In contrast, UD-GC was curable by endoscopic resection in all patients without HP infection.

The coronavirus pandemic significantly impacted endoscopic practice. During lower gastrointestinal endoscopy, infectious substances disseminate; therefore, we developed an infection control device (STEP-L) for lower gastrointestinal endoscopy and examined its usefulness.STEP-L wraps around the patient's buttocks and covers the endoscope. Using lower endoscopy training models, three endoscopists performed 18 colonoscopies with STEP-L (group S) and without (group C). Endoscopic insertion time and pigmented areas of ​​gloves and diapers after the examination were compared between both groups.Insertion of the endoscope up to the cecum was possible in all 18 examinations. The insertion time to the cecum was 52.4 ± 19.0 s in group S and 53.9 ± 13.3 s in group C. The pigmented areas of the ​​gloves measured 39,108.0 ± 16,155.3 pixels in group C, but were significantly reduced to 2610.5 ± 4333.8 pixels in group S (Using STEP-L does not change the insertion time, and is technically feasible. STEP-L significantly reduces the adhesion of virtual pollutants to the surroundings, suggesting that this device is useful for infection control during lower gastrointestinal endoscopy.

Background and study aims Endoscopic submucosal dissection (ESD) is widely performed for superficial esophageal cancer, but stricture after extensive resection is a major clinical problem. Using an ultrathin endoscope would enable endoscopists to approach lesions beyond the stricture. We evaluated the feasibility of an ultrathin endoscope for esophageal ESD. Methods To perform ESD with an ultrathin endoscope, we developed a transparent hood and ESD knife. A total of 24 esophageal ESDs were performed by two endoscopists with excised and live porcine esophaguses. A GIF-Q260 J and Dual knife were used in the conventional group and the GIF-XP260NS and a newly developed knife were used in the ultrathin group. En bloc resection rates, perforation rates, and procedure times were compared. Results All 24 lesions were resected en bloc without perforation. The mean procedure time was longer in the ultrathin group, although not significantly so (274.3 ± 81.8 s vs 435.8 ± 313.9 s, respectively; P = 0.22). Conclusion Although the procedure time was longer in the ultrathin group, en bloc resection was performed without any perforation. The findings indicate that esophageal ESD with an ultrathin endoscope is feasible.

Background and study aimsTreatment of superficial cancer in the remnant esophagus after esophagectomy is highly invasive, and early detection and minimally invasive treatment are considered necessary. We performed endoscopic submucosal dissection (ESD) for superficial cancer in the remnant esophagus and evaluated its safety and efficacy.Patients and methodsThis study involved 28 patients (33 lesions) who underwent ESD for superficial esophageal cancer in the remnant esophagus after esophagectomy from January 2007 to December 2018. The safety and efficacy of ESD were evaluated retrospectively.ResultsThe average age of all 28 cases (24 men and 4 women) was 69.6 ± 5.3 years. The average duration of ESD from esophagectomy was 2826 ± 2197 days. Twenty-six of the 28 cases were treated under general anesthesia. All 33 lesions were resected en bloc. The complete resection rate was 81.8% (27/33). There were no serious adverse events such as perforation, intraoperative bleeding, postoperative bleeding, and pneumonia. The overall survival rate was 78.6% (22/28) with a mean observation period post-ESD of 1793 ± 1148 days. There was no local recurrence, lymph node metastasis, or distant metastasis.ConclusionsThe ESD procedure for superficial cancer of the remnant esophagus was performed with high rate of complete resection without serious complications. In addition, there was no local recurrence and lymph node metastasis, and so ESD for superficial cancer of the remnant esophagus can be considered a safe and effective treatment.

Objective Clipping is a common technique for managing colonic diverticular bleeding (CDB), despite the lack of published evidence regarding its effectiveness. We aimed to evaluate the effectiveness of clipping for CDB in preventing early recurrent bleeding. Methods This dual-center retrospective study included 93 patients who underwent emergency hospitalization for bloody stool, diagnosed with definitive CDB, and treated with clipping or conservative treatment. The primary outcome was early recurrent bleeding. A logistic regression analysis was performed to assess the association between the occurrence of early recurrent bleeding and clipping with adjustment for propensity scores. Secondary outcomes included death, transfusion, length of hospitalization, need for transcatheter arterial embolization or surgery, and adverse events. Results The patient characteristics were similar between the clipping (n=85) and conservative treatment (n=8) groups. The rate of early recurrent bleeding was significantly lower in the clipping group than in the conservative treatment group [23.5% (20 cases) vs. 75% (6 cases), p=0.005]. In the propensity score-adjusted logistic regression analysis, the odds ratio for early recurrent bleeding in the clipping group was 0.094 (95% confidence interval, 0.008-0.633, p=0.026). Secondary outcomes were not significantly different between the two groups. Stigmata of recent hemorrhage (SRH) at the time of recurrent bleeding was identified in 79.2% of patients (19/24). In the clipping group, recurrent bleeding was observed in 62.5% of cases (10/16) from the same diverticulum. However, early recurrent bleeding tended to be less likely with direct clipping (p=0.072). Conclusion Clipping for definite CDB was more effective in preventing early recurrent bleeding than conservative treatment.

Background. Gastroesophageal reflux disease is diagnosed endoscopically based on the presence of mucosal breaks. However, mucosal breaks can be judged differently depending on the endoscopist, even in the same image. We investigated how narrow-band imaging (NBI) and magnified endoscopy affect the judgment of mucosal breaks. Methods. A total of 43 consecutive patients were enrolled who had suspected mucosal breaks on white-light images (WLI) and underwent nonmagnified NBI (N-NBI) and magnified NBI (M-NBI) by a single endoscopist. From WLI, N-NBI, and M-NBI, 129 image files were created. Eight endoscopists reviewed the image files and judged the presence of mucosal breaks. Results. The 8 endoscopists determined mucosal breaks were present in 79.4 ± 9.5% (67.4%–93.0%) on WLI, and 76.7 ± 12.7% (53.5%–90.7%) on N-NBI. However, the percentage of mucosal breaks on M-NBI was significantly lower at 48.8 ± 17.0% (18.6%–65.1%) ( p < 0.05 ). Intraclass correlation between observers was 0.864 (95% CI 0.793–0.918) for WLI and 0.863 (95% CI 0.791–0.917) for N-NBI but was lower for M-NBI at 0.758 (95% CI 0.631–0.854). Conclusion. Rates of detection and agreement for mucosal breaks on WLI and N-NBI were high among endoscopists. However, these rates were lower on M-NBI.

Objective Esophagogastric junction outflow obstruction (EGJOO) is a diagnosis of unclear significance that has become increasingly common with recent advances in high-resolution manometry (HRM). EGJOO can be divided into mechanical or functional obstruction. Functional EGJOO is considered an incomplete phenotype or an early stage of achalasia. However, little is known about the endoscopic findings in patients with functional EGJOO. Thus, we aimed to elucidate the endoscopic findings in patients with functional EGJOO and to identify patients at high risk for achalasia. Methods This was a single-center retrospective study. A total of 259 patients underwent esophagogastroduodenoscopy (EGD) along with HRM for upper gastrointestinal symptoms without any obstructive lesions or stricture between July 2013 and September 2019 in our institute. Among them, 31 patients were diagnosed with EGJOO. After excluding patients who had undergone previous endoscopic treatment, those who were diagnosed with eosinophilic esophagitis and those who had undergone EGD at other institutes, 23 patients were finally included with a diagnosis of functional EGJOO. The endoscopic findings were evaluated by three endoscopists. Results Five patients (21.7%) had an esophageal rosette sign (ERS). No patients had grade IV gastroesophageal flap valve, esophageal mucosal breaks, or abnormal retention of liquid or food in the esophagus. Manometric findings revealed that the median distal contractile integral value was significantly higher in patients with an ERS (n=5) than in those without it (n=18). Conclusion There were some patients with functional EGJOO who had an ERS, which is the characteristic endoscopic finding in achalasia.

This study aimed to reveal long-term outcomes, such as incidence of metachronous esophageal and head and neck squamous cell carcinomas and overall survival rate, through long-term observation of patients with esophageal carcinoma post-endoscopic submucosal dissection. Risk of metachronous carcinogenesis was evaluated in 88 patients with intramucosal esophageal carcinoma (without history of metachronous esophageal or head and neck squamous cell carcinomas) who underwent endoscopic submucosal dissection from 2007 to 2008 and were endoscopically observed for > 3 years. Histologically, the papillary vessel is defined as the clock gear-like structure composed of capillaries directly penetrating the epithelium (starting from the lamina propria) and covering at least two-thirds of it, around which the tumor cells are arranged in a spiral pattern. Median endoscopic follow-up period was 11.0 years. Cumulative 2-, 5-, and 10-year metachronous esophageal carcinoma rates were 11.4%, 20.6%, and 39.3%, respectively. Stepwise multivariate Cox proportional hazard regression analysis identified multiple Lugol-voiding lesions (LVLs) as the single significant independent predictor. Cumulative 2-, 5-, and 10-year metachronous head and neck squamous cell carcinoma rates were 6.9%, 10.4%, and 19.6%, respectively. Stepwise multivariate Cox proportional hazard regression analysis identified multiple LVLs, Brinkman index, papillary vessel, and younger age as significant predictive factors. Overall post-endoscopic submucosal dissection survival rates were 98.8% and 87.5% at 5 and 10 years, respectively. Patients with a history of esophageal carcinoma remain at risk for metachronous carcinogenesis even > 5 years after endoscopic submucosal dissection. Thus, long-term follow-up is important.

Background: Refractory reflux esophagitis (RRE), unresponsive to conventional proton-pump inhibitors (PPIs), is a complication in esophagectomy with gastric pull-up. Vonoprazan (VPZ), a novel potassium-competitive acid blocker, has been available in Japan since 2015. Here, we investigated the efficacy of VPZ on PPI-resistant RRE after esophagectomy with gastric pull-up. Methods: This was a single-center retrospective study. We used the revised Los Angeles (r-LA) classification based on the Los Angeles classification and the modified Los Angeles classification to evaluate abnormal forms of mucosal breaks such as lateral spreading consistently. Patients who underwent esophagectomy with gastric pull-up and had RRE grade B–D as per the r-LA classification, despite using standard-dose PPIs or double dose of rabeprazole, were included. Sixteen patients who switched to VPZ (20 mg/day) and 14 patients who continued PPIs were assigned to the VPZ and PPI groups, respectively. Endoscopic observations were reviewed by 3 endoscopists using the r-LA classification to ensure consistent diagnosis, while the treatment arm and patient information were blinded to evaluators. We defined mucosal breaks that improved by at least one grade after treatment as improved mucosa and recovery to grade M or N as mucosal healing. Results: The percentage of patients with improved mucosa in the VPZ and PPI groups was 81.3 and 14.3%, respectively (p < 0.001). The rate of mucosal healing was 68.8 and 7.1%, respectively (p = 0.001). Conclusion: VPZ significantly improved PPI-resistant RRE after esophagectomy with gastric pull-up.

Introduction: Patients with ulcerative colitis (UC) have an increased risk of colorectal cancer. Some studies have recently investigated endoscopic resection of UC-associated neoplasia (UCAN), but the indications for endoscopic resection of UCAN remain controversial. This study sought to clarify the problems encountered in endoscopic submucosal dissection (ESD) for UCAN. Methods: Seventeen lesions in 12 patients with UCAN (UCAN group) and 913 epithelial lesions in 824 control patients without UC (non-UC group) were evaluated. Both groups underwent ESD between January 2010 and December 2017 at Toranomon Hospital, Tokyo, Japan. Treatment outcomes of the 2 groups were compared retrospectively. Results: Univariate analysis showed that the mean tumor size was significantly smaller in the UCAN group than in the non-UC group (25.1 ± 26.7 mm vs. 31.9 ± 19.0; p = 0.0023); however, the R0 resection rate was significantly lower in the UCAN group (70.6 vs. 92.9%; p = 0.001). Multivariate analysis showed a significantly lower negative horizontal margin rate in the UCAN group (odds ratio 11.3, 95% confidence interval 3.588–34.525; p = 0.000). Discussion/Conclusion: ESD for UCAN is associated with a low-negative horizontal margin rate. When performing ESD for UCAN, it is important to evaluate the accuracy of the UCAN demarcation line, especially for flat lesions, using white-light imaging and chromoendoscopy as well as other modalities, including biopsy of surrounding tissues.

Introduction: Multiple Lugol-voiding lesions (LVLs) in the esophagus increase the risk of synchronous and metachronous development of esophageal squamous cell carcinoma (ESCC). Chemoradiotherapy (CRT) following endoscopic submucosal dissection (ESD) may reduce the incidence of metachronous ESCC, but few studies have investigated this. Therefore, we retrospectively examined the effect of CRT on metachronous ESCC and multiple esophageal dysplasias visible as multiple LVLs. Methods: This study reviewed 146 patients who underwent esophageal ESD and were determined pathologically to have noncurative resection. They were divided into 2 groups: those who received additional CRT (CRT group; n = 64) and those without additional treatment (control group; n = 82). Incidence of metachronous ESCC was analyzed using propensity scores to adjust for patient characteristics. The number of multiple LVLs was also examined. Results: The CRT group was significantly younger than the control group (mean 66.6 vs. 70.6 years, p = 0.011), had significantly deeper tumor invasion (p = 0.013), and had a significantly higher rate of lymphovascular invasion (47.8 vs. 12.2%, p < 0.001). The CRT group also had a significantly higher improvement rate of multiple LVLs (58.1 vs. 2.0%, p < 0.001). The LVLs after CRT had a distinctive irregular crack-shaped appearance. Metachronous ESCC was found in 7 patients (10.9%) in the CRT group and in 17 patients (20.7%) in the control group (p = 0.113). In propensity score-adjusted logistic regression analysis, the odds ratio for metachronous ESCC in the CRT group was 0.316 (p = 0.023). The occurrence rate was significantly lower in the CRT group than in the control group. Discussion/Conclusion: CRT may be effective in preventing metachronous ESCC.

Background and Aims. Endoscopic submucosal dissection (ESD) is widely performed for early gastric cancer (EGC). We have sometimes encountered gastric cancer lesions for which ESD was performed and at which pathologically advanced cancer was found. In this study, we performed clinicopathological examination of lesions whose endoscopic diagnosis and pathology differed substantially. Methods. ESD was performed for 2,194 gastric cancer lesions (1,753 cases) in our institute from April 2005 through March 2015. The vertical margin was positive or status unknown in 51 lesions (2.3%); among these, muscularis propria (MP) or deeper infiltration was identified in 6 lesions from specimens obtained during subsequent surgery. In 1 lesion with MP invasion, the vertical margin was negative. We evaluated the clinicopathological features of these 7 lesions and retrospectively reviewed endoscopic indicators of submucosal invasion for EGC on white light imaging (WLI), narrow-band imaging magnifying endoscopy (NBI-ME), and endoscopic ultrasonography (EUS) performed previously. Results. Average age was 73.2±7.2 years, and all cases were men. The 7 lesions diagnosed as advanced cancer were 0.32% of 2,194 lesions and were all located in the U region (fundus). On retrospective review of endoscopic findings, 2 of 7 lesions on WBI, 3 of 6 lesions on NBI-ME, and 2 of 5 lesions on EUS met the criteria for indicating submucosal invasion of EGC. No lesions had findings on all 3 modalities. Conclusion. In rare cases, advanced gastric cancer could not be accurately diagnosed by endoscopy using various modalities. Each case had special characteristics making identification of deep infiltration difficult.

Background and study aims Esophageal endoscopic submucosal dissection (ESD) has gradually acquired popularity as a minimally invasive surgery for early cancers not only in Japan, but also in other countries. However, most reported outcomes have been based on relatively small samples of patients from specialized centers. Therefore, the association between hospital volume and the rate of adverse events following esophageal ESD has been poorly understood. Patients and methods Using a nationwide administrative database in Japan, we identified patients who underwent esophageal ESD between 1 July 2007 and 31 March 2013. Hospital volume was defined as the number of esophageal ESD procedures performed per year at each hospital and was categorized into quartiles. Results In total, 12 899 esophageal ESD procedures at 699 institutions were identified during the study period. Perforation and perforation-related disorders were observed in 422 patients (3.3 %), and one patient died after perforation. There was a significant association between a lower hospital volume and a higher proportion of adverse events following esophageal ESD. Although not statistically significant, a similar tendency was observed in the occurrence of blood transfusion within 1 week after ESD and all-cause in-hospital death. Multivariable logistic regression analysis showed that hospitals with very high case volumes were less likely to experience adverse events following esophageal ESD than hospitals with very low volumes. Conclusions The proportion of perforation and perforation-related disorders following esophageal ESD was permissibly low, and there was a linear association between higher hospital volume and lower rates of adverse events following esophageal ESD.

Background and study aims Delayed bleeding is one of the most serious adverse events of gastric endoscopic submucosal dissection (ESD), especially in patients taking antithrombotic therapy. This study aimed to evaluate the utility and safety of a shielding method with autologous fibrin glue and polyglycolic acid (PGA) sheets for patients undergoing gastric ESD who are receiving antithrombotic therapy. Patients and methods One hundred twenty-three patients who were treated with gastric ESD while receiving antithrombotic therapy between December 2014 and September 2017 were enrolled in this study. Patients who received the shielding method were classified into the shielding group. Others were classified into the conventional group. Various clinico-pathological factors were retrospectively compared between the two groups. Results The shielding group consisted of 38 patients, and the conventional group consisted of the remaining 85 patients. In the shielding group, the rate of continuation of antithrombotic therapy was significantly higher (68.4 % vs 41.2 %). Incidence of delayed bleeding was lower in the shielding group (2.6 %, 1/38) than in the conventional group (14.1 %, 12/85). In the propensity score-adjusted logistic regression analysis, the delayed bleeding rate in the shielding group tended to be lower than in the conventional group (P = 0.070). Allogeneic transfusion was performed in eight patients (8/85, 9.4 %) in the conventional group and none in the shielding group (P = 0.047). No adverse event associated with endoscopic shielding were observed in the shielding group. Conclusions This study suggests that a shielding method with autologous fibrin glue and PGA sheet effectively prevents delayed bleeding after gastric ESD in patients receiving antithrombotic therapy.

Background/Aims: Almost all previous studies related to rectal foreign bodies were based on bizarre and striking cases, resulting in a reporting bias. Our aim was to clarify the clinico-epidemiological findings of rectal foreign body (RFB) in a general population. Methods: Using a national administrative database in Japan, we identified patients who underwent in-hospital treatment for rectal foreign bodies from 1 July 2007 to 31 March 2013. Results: A total of 648 RFB patients with 666 presentations were identified during the study period. The number of male patients was 526 (81.1%). The incidence of a RFB was most frequently seen in males who were in their 60s and in females who were in their 80s. The overall in-hospital mortality was 1.2%. Compared with males, females had a significantly higher proportion of in-hospital death (0.4 vs. 4.8%, p = 0.001), perforation and peritonitis (5.2 vs. 12.8%, p = 0.004), and sepsis (1.1 vs. 4.0%, p = 0.04). Conclusion: This study showed the clinico-epidemiological findings of rectal foreign bodies in a general population, and established that there was a low mortality rate. It was also found that females were significantly more likely to have a severe outcome following a RFB than males.

This study gives, first, an introductory account of competition policy in Japan, both from a legal and economic standpoint, and provides several illustrative actual cases. The aim is to present a general introduction, from an economist’s perspective, of Japanese competition policy and the associated law, the Antimonopoly Act, without excessive legal detail. Second, this study shows how competition policy can be implemented in a way that promotes innovation and dynamic competition. Certain forms of collaboration among competitors may be beneficial to competition, such as joint research and development (R&D), patent pooling, and standard setting. The study discusses how these forms of collaboration should be assessed from the perspective of competition policy.

OBJECTIVES To evaluate the accuracy of vascular diameter measurement on computed tomographic (CT) angiography using adaptive statistical iterative reconstruction (ASIR). METHODS We scanned 9 vascular models with 3 wall thicknesses and filled with 3 densities of contrast material using a 64-detector CT unit, reconstructed images using ASIR (0%, 20%, 40%, 60%, 80%, and 100%), and repeated 20 separate diameter measurements for each model. We evaluated the distribution of image noise for the 0% and 100% ASIR. RESULTS For all vascular models, measurement errors differed significantly (P < 0.0001) among the percentages of ASIR, tending to increase as the percentage of ASIR increased for models filled with 246 and 354 Hounsfield units of contrast medium. The degree of image noise depended on the substance within the model with 100% ASIR. CONCLUSIONS Adaptive statistical iterative reconstruction can enhance errors in diameter measurement on CT angiography and should be applied carefully to evaluate small vessels.

How are new university educational programs established in response to expanding sciences and how do they promote university–industry (UI) joint research? To study these questions in relation to life sciences and biotechnology, we first compiled the data on the establishment of new undergraduate and graduate programs on these fields in Japanese universities since the 1950s. We then analyzed statistically whether and how such establishment contributed to the occurrence and frequency of UI joint research in biotechnology. We found that the expansion of such university programs in fact contributed to the promotion of UI joint research. We also confirmed that, even with this contribution controlled, UI joint research projects increased following the 1998 legislation to promote technology transfer from universities (the so-called TLO Act) and the 1999 legislation to allow universities to retain rights on their inventions made with government research funds (the so-called Japanese Bayh–Dole Act).

To discuss the role of bank-dispatched directors in the governance of Japanese firms, it has to be noted that the board is heterogeneous and only senior directors, including presidents and managing directors, are likely involved in major management decisions. With a panel of about 1150 firms in 1990–98, we find that, when bank loans constitute a significant portion of the firm's assets, the low industry-adjusted profitability increases the probability that a new (or additional) director is dispatched from the bank at a senior level but not at a junior level. This dispatch improves the firm's performance provided it does not merely replace the predecessor.

Previous studies reported that endoscopic resection is effective for the treatment of superficial pharyngeal cancers, as for digestive tract cancers. However, the optimal treatment for superficial cancer of the uvula has not been established because of the rarity of this condition. We present two male patients in their 70s with superficial cancer of the uvula, detected with upper gastrointestinal endoscopy. Both patients underwent surgical resection of the uvula under general anesthesia. The extent of the lesions was determined by means of gastrointestinal endoscopy by using magnifying observation with narrow-band imaging, enabling the performance of minimally invasive surgery. Endoscopic submucosal dissection was performed to achieve en bloc resection of the intramucosal carcinoma that had infiltrated the area adjacent to the uvula. Gastrointestinal endoscopists should carefully examine the laryngopharynx to avoid missing superficial cancers. Our minimally invasive treatment for superficial cancer of the uvula had favorable postoperative outcomes, and prevented postoperative loss of breathing, swallowing, and articulation functions.

BACKGROUND Colorectal endoscopic submucosal dissection has gained popularity as a minimally invasive technique for the treatment of colorectal neoplasms in many countries, including Japan. However, most previous studies of endoscopic submucosal dissection had relatively small sample sizes and only included patients treated at specialized centers. Associations between hospital volume and complication rates after colorectal endoscopic submucosal dissection are still poorly understood. OBJECTIVE Our aim was to clarify the relationships between hospital volume and the occurrence rates of bleeding and perforation after colorectal endoscopic submucosal dissection. DESIGN This was a retrospective cohort study. Hospital volume was defined as the number of colorectal endoscopic submucosal dissections performed at each hospital between April 2012 and March 2013 and was categorized into the following quartiles: 1) very low-volume (18 or less patients during the year), 2) low-volume (19-35 patients), 3) high-volume (36-58 patients), and 4) very high-volume (59 or more). SETTINGS This study was based on a national inpatient data from the Japanese Diagnosis Procedure Combination database. PATIENTS A total of 7567 patients with colorectal endoscopic submucosal dissection were included. MAIN OUTCOME MEASURES Severe postoperative bleeding requiring endoscopic hemostasis or blood transfusion within 1 week after endoscopic submucosal dissection and perforation requiring open surgery were the main outcomes measured. RESULTS Severe postoperative bleeding and perforation occurred in 331 (4.4%) and 13 patients (0.2%). Multivariable logistic regression analysis showed that the very high hospital volume group had a significantly lower proportion of severe postoperative bleeding than the very low hospital volume group (OR = 0.48 [95 % CI, 0.27-0.83]; p = 0.009). LIMITATIONS This study lacked some information on clinicopathologic features including en bloc resection, curative resection, and relapse. Individual endoscopist experience could not be analyzed. CONCLUSIONS The present study clearly showed a significant association between higher hospital volume and lower occurrence of severe postoperative bleeding.