Yamada Type Research Articles

Clinical Characteristics and Endoscopic Management of Duodenal Lipomas: 10-Year Experience from a Tertiary Center in China.

Duodenal lipomas are rarely found in the gastrointestinal tract. Most published literature referring to the tumors is limited to case series. There remained issues about the understanding and management of duodenal lipomas to be clarified. We aimed to investigate the clinical and endoscopic features of duodenal lipomas. Additionally, outcomes of endoscopic resection for duodenal lipomas were evaluated. A total of 29 duodenal lipomas resected endoscopically from December 2011 to October 2021 were included. Clinical characteristics, endoscopic features, and endoscopic ultrasound findings were analyzed retrospectively. The endoscopic resection was performed in 3 ways: hot snare polypectomy, endoscopic mucosa resection, and endoscopic submucosal dissection. Of the 29 duodenal lipomas, 21 were located at the second portion with a mean size of 25.8 mm (range, 7-60 mm). Yamada type IV was the most common macroscopic type in 14 lesions, exhibiting a tendency of forming large peduncles. Seven patients had digestive symptoms. The occurrence of symptoms is associated with the tumor size. Endoscopic ultrasound was performed on 23 duodenal lipomas, of which 20 demonstrated homogenous echogenicity and 3 presented heterogeneous with tubular anechoic region. The endoscopic resection operation was successfully conducted on 29 patients without severe adverse events. The rate of en bloc and endoscopic complete resection was 93.1% and 86.2%, respectively. Recurrence was noted in 1 patient. Clinical characteristics with typical endoscopic ultrasound features are helpful in duodenal lipomas diagnosis. The endoscopic resection is a safe and effective treatment for duodenal lipomas with considerable long-term outcomes.

Image Mosaic Algorithm-Based Analysis of Pathological Characteristics of Gastric Polyp Patients Using Computed Tomography Images.

The application value of image mosaic algorithm (IMA) based CT imaging technology in the analysis of pathological characteristics of gastric polyp (GP) patients was explored in this work. 588 cases of GP patients in the hospital were selected as the research objects, and CT images based on IMA were adopted for examination. The patient's basic information, image performance, and gastroscopy results were recorded. The results showed that the absolute mean bright error (AMBE) index and information entropy of the IMA are 0.0625 and 7.0385, respectively. The clinical symptoms of patients were mostly abdominal pain (21.4%), abdominal distension (15.6%), and sour regurgitation (17.8%). The common size of GP was no more than 0.5 cm, and the common type was Yamada type II. There were notable differences between single and multiple GPs of different pathological types (P < 0.05). Proliferative polyps were mostly found in the stomach and antrum, while fundus gland polyps were mostly in the stomach and fundus. There was significant difference between the growth location of the hyperplastic polyp and basal gland polyp (P < 0.05). In summary, the CT images of IMA proposed in this paper can not only realize image splicing effectively but also were superior to the traditional SIFT method in the quality of splicing image and were conducive to the analysis of the pathological characteristics of GP patients, which had significant clinical promotion value.

Analysis of 234 cases of colorectal polyps treated by endoscopic mucosal resection.

BACKGROUNDColorectal polyps refer to all neoplasms that protrude into the intestinal cavity. Researchers believe that 50%-70% of colorectal cancers originate from adenomatous polyps.AIMTo investigate the endoscopic morphologic features, pathologic types, and clinical situation; evaluate the efficacy and safety of endoscopic mucosal resection (EMR); and guide clinicians in their daily practice.METHODSTwo hundred thirty-four patients who underwent EMR in our hospital from January 1, 2018 to December 31, 2019 were recruited. Data including sex, age, endoscopic morphology of the polyps, and pathological characteristics were analyzed among groups.RESULTSA total of 295 polyps were resected from the 234 subjects enrolled in the study, of which 4 (1.36%) were Yamada type I. There were 75 (25.42%) type II, 101 (34.24%) type III, and 115 (38.98%) type IV adenomas. Among them, 41 were non-adenomas, 110 were low-risk adenomas, 139 were high-risk adenomas, and 5 were carcinomas. The differences in distribution were not statistically significant, with P values greater than 0.05. The risk of cancer significantly increased for polyps ≥ 1 cm in diameter (c2 = 199.825, P = 0.00). Regarding the endoscopic morphological features, congestion, erosion, and lobulation were more common on the surface morphology of high-risk adenomas and cancerous polyps (c2 = 75.257, P = 0.00), and most of them were Yamada types III and IV. In all, 6 of the 295 polyps could not be removed completely, with a one-time resection rate of 97.97%. There were two cases of postoperative bleeding and no cases of perforation, with an overall complication rate of 0.09%. CONCLUSIONColorectal polyps ranging from non-adenomatous polyps, low-risk adenomas, and high-risk adenomas to adenocarcinomas each has their own endoscopic features, while EMR, as a mature intervention, has good safety and operability and should be promoted clinically, especially at the primary care level.

Characteristics of benign and malignant lesions of ampullary polyps and the accuracy of forceps biopsy

OBJECTIVE To distinguish the endoscopic and clinical features of ampullary polyps, to investigate the endoscopic cancer risk factors of ampullary polyps based on the compared differences of benign lesions and adenocarcinoma, and to assess the accuracy of forceps biopsy. METHODS Authors retrospectively analyzed the data extracted from patients treated with endoscopic papillectomy (EP) from January 2009 to May 2019 in the Department of Gastroenterology, Peking University Third Hospital. Endoscopic pictures and pathology reports were reevaluated and analyzed. Differences between benign and cancer groups were conducted. RESULTS In the study, 42 cases were involved, 35 to 83 years old, containing 83.3% older than 50 years old patients. The histological types were as follows, 2 for inflammatory polyps (4.8%), 1 for neuroendocrine tumor (2.4%), 1 for hyperplastic polyp (2.4%), 5 for grade Ⅰ adenoma (11.9%), 10 for grade Ⅱ adenoma (23.8%), 4 for grade Ⅲ adenoma (9.5%) and 19 for adenocarcinoma (45.2%), and 90.5% were adenoma or adenocarcinoma. The average age of benign group (inflammatory polyps and adenomas) was (56.7±9.2), which was significantly younger than that of adenocarcinoma group [(66.0±9.8), P=0.004]. Tumor diameter in adenocarcinoma group[(2.3±0.8) cm] was significantly larger than that in benign group[(1.6±0.6) cm, P=0.002]. Benign lesions only showed Yamada type Ⅰ(57.1%)and type Ⅱ(42.9%). The percentage of Yamada type Ⅰ (36.8%)and type Ⅱ(31.6%) in adenocarcinoma group was lower than that in benign group. Moreover, Yamada type Ⅲ (31.5%) was only found in the adenocarcinoma group. Significant differences were observed between the two groups in Yamada types (P=0.046). Most of the benign lesions had clear boundary(18/21, 85.7%). The percentage of clear boundary in adenocarcinoma group (2/19, 10.5%) was significantly lower than that in the benign group (P < 0.001). No significant differences were investigated in color (P=0.353) and surface (P=0.324) between benign and adenocarcinoma lesions. Pooling age, lesion diameter, Yamada type and clear boundary into Logistic regression analysis, only age (OR=1.186, 95%CI 1.025-1.373, P=0.022) and clear boundary (OR=66.218, 95%CI 3.421-1 281.840, P=0.006) were the independent cancer risk factors. Only 2 (10.5%) in the 19 cancer patients had positive biopsy results before EP. As compared with post-EP, 55.3% (21/38) biopsies were under-estimated, including 17 (17/19, 89.5%) adenocarcinomas and 4 (4/10, 40%) grade Ⅱ adenomas. CONCLUSION adenoma and adenocarcinoma were the major histological type of ampullary po-lyps. Age and unclear boundary were the independent risk factors of ampullary adenocarcinoma. Forceps biopsy was not enough for ampullary polyp differentiation.

A novel summary report of colonoscopy: timeline visualization providing meaningful colonoscopy video information.

The colonoscopy adenoma detection rate depends largely on physician experience and skill, and overlooked colorectal adenomas could develop into cancer. This study assessed a system that detects polyps and summarizes meaningful information from colonoscopy videos. One hundred thirteen consecutive patients had colonoscopy videos prospectively recorded at the Seoul National University Hospital. Informative video frames were extracted using a MATLAB support vector machine (SVM) model and classified as bleeding, polypectomy, tool, residue, thin wrinkle, folded wrinkle, or common. Thin wrinkle, folded wrinkle, and common frames were reanalyzed using SVM for polyp detection. The SVM model was applied hierarchically for effective classification and optimization of the SVM. The mean classification accuracy according to type was over 93%; sensitivity was over 87%. The mean sensitivity for polyp detection was 82.1%, and the positive predicted value (PPV) was 39.3%. Polyps detected using the system were larger (6.3 ± 6.4 vs. 4.9 ± 2.5mm; P = 0.003) with a more pedunculated morphology (Yamada type III, 10.2 vs. 0%; P < 0.001; Yamada type IV, 2.8 vs. 0%; P < 0.001) than polyps missed by the system. There were no statistically significant differences in polyp distribution or histology between the groups. Informative frames and suspected polyps were presented on a timeline. This summary was evaluated using the system usability scale questionnaire; 89.3% of participants expressed positive opinions. We developed and verified a system to extract meaningful information from colonoscopy videos. Although further improvement and validation of the system is needed, the proposed system is useful for physicians and patients.

Endoscopic resection for duodenal subepithelial tumors: a single-center experience.

Subepithelial tumors (SETs) in the gastrointestinal tract are often incidentally found during endoscopic examinations. Although the utility and safety of endoscopic resection (ER) of SETs in the esophagus and stomach have been described, data about the ER of duodenal SETs remain scant. Therefore, we aimed to investigate the clinical outcomes associated with the ER of duodenal SETs and to assess possible predictive factors for incomplete resection. We conducted a retrospective observational study of 62 patients (64 lesions) that underwent ER of duodenal SETs between June 2005 and December 2015 at the Pusan National University Hospital. The therapeutic outcomes from ER and procedure-related complications were analyzed. Endoscopic mucosal resection (EMR) was performed in 38 tumors, EMR with a ligation device (EMR-L) in 18 and endoscopic submucosal dissection (ESD) in 8. The overall en bloc resection and complete ER rates were 96.9% (62/64) and 100% (64/64), respectively. The complete pathologic resection rate was 76.6% (49/64). Multivariate logistic regression analyses determined that the macroscopic type (Yamada type I or II; odds ratio [OR] 6.460, 95% confidence interval [CI] 1.569-37.458, p=0.027) and the treatment method (ESD; OR 7.178, 95% CI 1.291-39.323, p=0.024) were independently associated with incomplete pathologic resection. The procedure-related bleeding and perforation rates were 6.3% and 4.7%, respectively. No recurrences were observed in patients who had undergone complete ER at a median follow-up period of 20months (range 6-112months). ER is an effective, safe, and feasible treatment for duodenal SETs, especially when the SET is located in the deep mucosal layer and/or the submucosal layer.

Endoscopic findings of colonic polyps with different pathological types

The endoscopic findings of 884 cases of colonic polyps with different pathological types were retrospectively analyzed.Among all cases,there were 418 cases of tubular adenoma (47.3％ ),92 cases of fluff tubular adenoma ( 10.4％ ),334 cases of inflammatory polyps ( 37.8％ ) and 40 cases of hyperplastic polyps (4.5％ ).There were significant differences in age,location,polyp surface morphology and Yamada grouping among colonic polyps with different pathological types (P ＜0.05).The average age of fluff tubular adenoma group [ (64 ± 12)y] was the highest among all patients; and the average diameter of polyps was the largest [ ( 1.38 ± 1.09 ) cm ],lobulated and mulbenry,polyps were the most common forms; and the majority of fluff tubular adenoma was Yamada type Ⅲ or Ⅳ.The results indicate that fluff tubular adenoma was associated with higher age,larger polyp size,surface morphology and Yamada grouping (P ＜0.05). Key words: Intestinal polyps; Endoscopy,gastrointestinal

Turbulence characteristics in the bottom layer of a shallow tidal channel

Observation of a shallow tidal channel was executed to examine turbulent evolution in ideal condition of weak, stratified flow for a complete cycle of semi-diurnal tide. Duration of this study allows a maximum velocity variation and therefore gives comprehensive interpretation of the relevant processes such as momentum and heat transfer, turbulent kinetic energy (TKE) production and dissipation rates. Under weak stratification condition dominant through the observation period testing the parameterization of dissipation rate in the Mellor–Yamada type models revealed that close to the bed perhaps due to boundary effects experimental dissipation closure constant values were remarkably larger than commonly used value of 16.6. Also, the effect of extending critical Richardson number Ricr to infinity on parameterization of stability functions, eddy viscosity, and turbulent Prandtl number in Kantha–Carniel model was also examined. It was found that despite Kantha–Carniel model reconstructed bottom boundary layer (BBL) turbulence characteristics well during the flooding tide, it underestimates those parameters during the ebbing tide partially due to underestimation of turbulence macroscale.

Spectrum of final pathological diagnosis of gastric adenoma after endoscopic resection

To investigate how many discrepancies occur in patients before and after endoscopic treatment of referred adenoma and the reason for these results. We retrospectively reviewed data from 554 cases of 534 patients who were referred from primary care centres for adenoma treatment and treated for endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) at Chungnam National University Hospital, from July 2006 to June 2009. Re-endoscopy was examined in 142 cases and biopsy was performed in 108 cases prior to treatment. Three endoscopists (1, 2 and 3) performed all EMRs or ESDs and three pathologists (1, 2 and 3) diagnosed most of the cases. Transfer notes, medical records and endoscopic pictures of these cases were retrospectively reviewed and analyzed. Adenocarcinoma was 72 (13.0%) cases in total 554 cases after endoscopic treatment of referred adenoma. When the grade of dysplasia was high (55.0%), biopsy number was more than three (22.7%), size was no smaller than 2.0 cm (23.2%), morphologic type was depressed (35.8%) or yamada type IV (100%), and color was red (30.9%) or mixed-or-undetermined (25.0%), it had much more malignancy rate than the others (P < 0.05). All 18 cases diagnosed as adenocarcinoma in the re-endoscopic forceps biopsy were performed by endoscopist 1. There were different malignancy rates according to the pathologist (P = 0.027). High grade dysplasia is the most important factor for predicting malignancy as a final pathologic diagnosis before treating the referred gastric adenoma. This discrepancy can occur mainly through inappropriately selecting a biopsy site where cancer cells do not exist, but it also depends on the pathologist to some extent.

A note on modeling double diffusive mixing in the global ocean

Though ubiquitous in the global oceans, double diffusive mixing has been largely ignored or poorly represented in the models of turbulent mixing in the ocean and in 3-D ocean models, until recently. Salt fingers occur in the interior of many marginal seas and ocean basins, the Tyrrhenian Sea and the subtropical Atlantic being two examples. Diffusive convection type of double diffusion occurs in the upper layers of many sub-polar seas and polar oceans due to cold melt water from sea ice. Consequently, it is important to be able to properly parameterize double diffusive mixing in basin scale and global ocean models, so that the water mass structure in the interior of the ocean can be properly simulated. This note describes a model for double diffusive mixing in the presence of background shear, based on Mellor–Yamada type second moment closure, more specifically Kantha (2003), Kantha and Clayson (2004) second moment closure models of resulting turbulence, following Canuto et al. (2008a) but employing a different strategy for modeling the pertinent terms in the second moment equations. The resulting model is suitable for inclusion in ocean general circulation models.

Brunner's Gland Hamartoma

To describe the computed tomographic (CT) features of Brunner's gland hamartoma with histopathologic correlation. The CT images of 9 patients with pathologically proven Brunner's gland hamartoma were reviewed retrospectively. All patients underwent CT performed on multidetector-row CT scanner with various protocols, all of which included portal venous phase. Brunner's gland hamartomas presented as small (mean, 1.9 cm) Yamada type II or III (67%, 6/9) polyps with frequent internal cyst (33%, 3/9). They were isoattenuated on unenhanced CT (83%, 5/6) and hypoattenuated in portal phase (56%, 5/9) when compared with the pancreas. Peripheral rimlike enhancement in earlier phase was commonly found (67%, 6/9) and most of them enhanced homogeneously in the later phase (100%, 4/4). In a patient with asymptomatic small submucosal mass in the duodenal first or second portion, hypoattenuated mass with peripheral rimlike enhancement or internal cystic change suggests the possibility of Brunner's gland hamartoma.

Hematochezia with Colonic Polypoid Angiodysplasia in a Young Female Patient

A 18-year-old girl visited the hospital due to hematochezia. Colonoscopy revealed a 6-mm Yamada type II polyp with stigmata of bleeding, and a shallow ulcer on top was found at the cecum base. The polyp was removed by snare polypectomy, and hematochezia stopped thereafter. Angiodysplasia was diagnosed histopathologically. Generally, angiodysplasia appears as a flat or elevated, bright-red lesion on endoscopy, with a polypoid shape being extremely rare. This case is significant because the lesion occurred at the youngest reported age and was the smallest that has been reported, and is the only polypoid arteriovenous malformation to be discovered in the cecum.

On an Improved Model for the Turbulent PBL

Abstract Cheng, Canuto, and Howard have presented a second-moment closure PBL model that appears to overcome some of the shortcomings of the existing Mellor and Yamada–type closure models. This note demonstrates that with a slight readjustment in the closure constants of the latter, more specifically the Kantha and Clayson closure model, they can be made to yield results very much similar to that of the Cheng et al. model.

An Improved Model for the Turbulent PBL

Second-order turbulence models of the Mellor and Yamada type have been widely used to simulate the planetary boundary layer (PBL). It is, however, known that these models have several deficiencies. For example, assuming the production of the turbulent kinetic energy equals its dissipation, they all predict a critical Richardson number that is about four times smaller than the large eddy simulation (LES) data in stably stratified flows and are unable to distinguish the vertical and lateral components of the turbulent kinetic energy in neutral PBLs, and they predict a boundary layer height lower than expected. In the present model, three new ingredients are employed: 1) an updated expression for the pressure–velocity correlation, 2) an updated expression for the pressure–temperature correlation, and 3) recent renormalization group (RNG) expressions for the different turbulence timescales, which yield 1) a critical Richardson number of order unity in the stably stratified PBL (at level 2 of the model), 2) different vertical and lateral components of the turbulent kinetic energy in the neutral PBL obtained without the use of the wall functions, 3) a greater PBL height, 4) closer comparisons with the Kansas data in the context of the Monin–Obukhov PBL similarity theory, in both stable and unstable PBLs, and 5) more realistic comparisons with the LES and laboratory data.

A Case of Disappearance of Yamada's Type II Multiple Hyperplatic Polyps of Stomach by Eradication of &lt;i&gt;Helicobacter Pylori&lt;/i&gt;

A 69-year-old woman who had underwent endoscopic polypectomy of stomach before 4 years was admitted to my clinic for endoscopy. In endoscopic examination, five polyps classified Yamada's type II were located on greater curvature of antrum, anterior wall of angulus and greater curvature of upper body. Histological findings of biopsied specimens from these polyps revealed hyperplasia of the foveolar epithelium with moderate infiltration of inflammatory cells which was consistent with hyperplastic polyp. These polyps were unchanged during 2 years and Helicobacter pylori (H. pylori) was found by the CLO test and cultures of biopsied specimens. She was treated with one week course of lansoprazole, amoxicillin and clarithromycin. About 14 months later, all polyps were disappeared and eradication of H. pylori was confirmed by biopsy, cultures and Urea breath test. These result suggests that eradication of H. pylori may be expected as a useful treatment to hyperplastic polyp of stomach.

A RESECTED CASE OF RECURRENT MINUTE CARCINOID OF THE DUODENUM AFTER OPERATION

This paper report a case of recurrent minute carcinoid of the duodenum after operation in a 44-year-old woman. The patient had undergone a partial resction of the duodenum for minute carcinoid (5mm in size, sm) in the descending part of the duodenum in 1993, and then was followed up in the outpatient clinic. In January, 1997, she was found having a Yamada's type 2 tumor about 1cm oral from the duodenal papilla. With a biopsy, carcinoid was diagnosed. The patient was admitted to the hospital for operation with a diagnosis of recurrence of duodenal carcinoid. At operation, an ill-defined indulation about 2cm in size infiltrating into the pancreatic head was seen, and a pancreatico duodenectomy was performed. In general, carcinoids of the duodenum which are less than 20mm in size and submucosal or shallower in tumor invasion are indicated local resection. In our case, however, despite the primary duodenal tumor was 5mm in size with the depth of tumor invasion of sm which fulfilled the conditions, the recurrece had occurred after operation, that was thought very rare. We decide that local resection can be indicated for minute carcinoids, but preoperative close examination of the depth of tumor invasion, intraoperative exploration of lymph nodes, and postoperative clinical observation may be important.

GANGLIOCYTIC PARAGANGLIOMA ON THE SECOND PORTION OF DUODENUM-A CASE REPORT-

A 45-year-old man was found to have a large polyp in the desending colon, and was admitted to the hospital for resection at laparotomy. Preoperatic endoscopy revealed a submucosal polyp of Yamada type III in the second portion of duodenum. Abdominal CT findings were negative and an endoscopic biopsy did not show malignancy. Surgical resections for these tumors were performed on an one-step approach. Immunohistochemically NSE, chromogranin A and S-100 protein stainings of this duodenal tumor were positive. Histology revealed gangliocytic paraganglioma and no malignancy. Among duodenal submucosal tumors which are believed to be relatively rare, those arising in the second portion of duodenum are so rare that only 18 cases including ours have been reported in Japan.

A CASE OF GASTRIC LEIOMYOMA CLOSE TO THE ESOPHAGOCARDIAC JUNCTION (EC-JUNCTION) WHICH WAS COMPLETELY RESECTED BY LAPAROSCOPIC WEDGE RESECTION METHOD

A 64-year-old woman was under observation for a submucosal tumor on the anterior wall of the stomach close to EC-junction which was detected 2 years before. The tumor rapidly enlarged in these several months. Upper gastrointestinal series and endoscopy revealed a submucosal tumor of Yamada's type II 2.5cm in longer diameter in the vicinity of the EC-junction with bridging fold. The tumor was shown as homogeneous mass connecting to the proper muscle layer in endoscopic ultrasonography. The patient underwent a laparoscopic wedge resection of the stomach after cutting of serosa surface on the tumor to prevent post-operative stenosis. The tumor was completely resected and histologically diagnosed as cellular leiomyoma. This procedure may be superior therapeutic method to the conventional laparotomy approach in the good curability, less post operative pain and excellent cosmetic benefit.

A CASE OF INTUSSUSCEPTION OF THE DUODENUM CAUSED BY A TUBULOVILLOUS ADENOMA

A 64-year-old woman was admitted to the hospital because of repeated periumbilical, pain. Fluoroscopic examination of the duodenum visualized a 6×4cm pedunculated polyp in the descending portion of the duodenum of which peduncle existed in the vicinity of the superior flexure. Duodenoscopy revealed no peduncle. Biopsy indicated adenoma. CT revealed a tumor of lamellar structure presenting an incomplete circumference proliferation with a low-density area at the descending portion of the duodenum. Gastroduodenal angiography showed a homogenous slight tumor stain. Based on these findings, the patient was diagnosed as having the peduculated adenoma in the upper region of the duodenum that headed intussusception, and was operated on. On laparotomy, the superior portion of the duodenum prolapsed into the descending portion causing the intussusception, and a tumor was palpated in the head. The intussusception was relieved and the duodenum was incised, when it was revealed that the tumor was Yamada's type III polyp and the peduncle-like existence was duodenal mucosa pulled by the polyp. The polyp was excised. Histopathologically it was tubulovillous adenoma without coexistence of any malignantcy. Postoperative course has been uneventful, as of 2 years and 6 months after the operation.

A CASE OF MULTIPLE CARCINOID OF THE STOMACH WITH HYPERGASTRINEMIA AND TYPE A GASTRITIS

We experienced a case of multiple carcinoid of the stomach with hypergastrinemia and type A gastritis in a 35-year-old man. Upper gastrointestinal series revealed an about 1cm polyp of Yamada's type II or III in the posterior wall of the upper body of the stomahc adjacent to the greater curvature and multiple minute polyps ranging from the upper body to fornix. All polyps were diagnosed as carcinoid on endoscopic biopsy. Ultrasonic endoscopy revealed that the lesions were localized in the submucosal layer. Serum gastrin level was as high as 1, 950pg/ml.Total gastrectomy was carried out and multiple gastric carcinoids (sm, n0) with type A gastritis were histologically confirmed. After the operation, serum gastrin level was normalized and the patient has been doing well as of 3 years or more after the operation. In the treatment of multiple gastric carcinoid with type A gastritis, total gastrectomy with lymph node dissection would have to be the standard operative procedure, in order to resect the fundic gland area completely which can be the origin of carcinoids and endocrine cell micronest.