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Summary: Background: The involvement of Mediterranean fever (MEFV) gene mutations in patients with inflammatory bowel disease unclassified (IBDU) remains unclear. This study aimed to determine the clinical characteristics and responsiveness to colchicine in Japanese patients with IBDU carrying MEFV mutations. Methods: In this retrospective cohort study, we examined MEFV mutations using gene analysis, clinical information, and colchicine responsiveness. Furthermore, we examined cytokine production in exon 2-mutated THP-1 cells (a monocytic cell line) and microbiome analysis. Findings: Of the 396 patients diagnosed with IBDU, 60.1% had MEFV mutations. Exon 2 mutations were the most common (83.7%). Among patients with available clinical information, 43.3% of patients with IBDU had typical Familial Mediterranean fever (FMF). The efficacy of colchicine in patients with IBDU carrying MEFV mutations was 84.6%. Significant differences were noted in the production of inflammatory; cytokines between THP-1 cells with and without MEFV mutations. Microbial compositions differed between patients with IBDU carrying MEFV mutations and patients with IBD and healthy controls. Interpretation: Patients with IBDU carrying MEFV mutations responded well to colchicine treatment. A notable subset of patients met the criteria for typical FMF. Alterations in intestinal microbiota may contribute to disease pathogenesis. Funding: This work was supported by the Japan Agency for Medical Research and Development (21ek0410057h0003), a grant from the Uehara Memorial Foundation, and the Health and Labour Sciences Research Grants for research on intractable diseases from the Ministry of Health, Labour and Welfare (MHLW) of Japan (Investigation and Research for Intractable Inflammatory Bowel Disease; Grant Number 20316729).

Abstract Background Carbohydrate sulfotransferase 15 (CHST15) is an enzyme biosynthesizing matrix glycosaminoglycan that modulates tissue remodeling. We evaluated the efficacy of add-on submucosal injections of GUT-1, the RNA oligonucleotide inhibitor of CHST15, to ongoing anti-tumor necrosis factor (TNF) antibody treatment in patients with moderate-to-severe ulcerative colitis (UC). Methods This was an open-label study of 250 nM of GUT-1 by endoscopic submucosal injections at weeks 0, 2, 4 in five UC patients who lost response during maintenance treatment to anti-TNF antibodies. The primary endpoint was the rate of endoscopic improvement at week 6 and secondary endpoints included the rates of clinical remission by modified Mayo Score (mMS). Patients received follow-up observation with continuous maintenance treatment by the same anti-TNF antibody till the time of clinical recurrence or for overall 52 weeks. Results At week 6, rates of endoscopic improvement and clinical remission were 80% (n = 4/5) and 60% (n = 3/5), respectively. The mean Endoscopy Subscore was reduced from 2.4 (95%CI: 1.7 to 3.1) at baseline, to 1.0 (95%CI: 0.1 to 1.9) at week 6. The mean mMS was reduced from 7.8 (95%CI: 6.2 to 9.4) to 1.3 (95%CI: 2.9 to 4.3). GUT-1 was well tolerated. Three patients did not show clinical recurrence for 52 weeks. All three corticosteroid-dependent patients showed no corticosteroid exposure for at least 24 weeks after achieving clinical remission. Multiple dosing was also well tolerated. Conclusions Add-on multiple injections of GUT-1 to ongoing anti-TNF antibody was able to induce rapid and durable clinical responses in UC patients who lost response to anti-TNF therapy. Trial registration Clinical trial Registration Number (Japan): UMIN000020900.

Abstract Chronic intestinal pseudo-obstruction (CIPO) is a severe and refractory intestinal motility disorder whose diagnosis currently relies on subjective imaging assessments. Cine magnetic resonance imaging (MRI) may potentially improve the quantitative analysis of gastrointestinal motility; however, suitable CIPO detection parameters should be determined. Cine MRI was performed in seven patients with CIPO and 11 healthy controls. The logarithm of the Mahalanobis distance (x1) and distance variation per time (x2) were used as the original parameters to determine CIPO diagnostic thresholds. Furthermore, the correlation between cine MRI findings and CIPO severity was investigated. Threshold values of α = 1.10 and β = 0.15 for x1 and x2, respectively, produced a CIPO diagnosis sensitivity of 1.00 (7/7) and specificity of 0.82 (9/11). The resulting error was 0.11 (2/18). The two parameters were correlated (Pearson’s correlation coefficient: − 0.52). Any of the intestinal tracts of patients with severe CIPO requiring home parenteral nutrition belonged to the region defined by x1 ≥ 1.10 and x2 ≤ 0.15. Cine MRI is effective for the quantitative evaluation of small intestinal motility and CIPO diagnosis when using the abovementioned parameters and can be useful for treatment decision-making. However, these parameters have a wide distribution in healthy volunteers; this may complicate the detection of other disorders.

Abstract Background Involuntary weight loss related to cachexia is common in patients with advanced cancer, but the association between body composition changes and survival is still unclear in pancreatic cancer. Methods We retrospectively reviewed the clinical outcomes of 55 patients with advanced pancreatic cancer undergoing palliative therapy or best supportive care (BSC). The skeletal muscle index (SMI), visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI), and visceral to subcutaneous adipose tissue area ratio (VSR) were calculated based on the cross‐sectional area on two sets of computed tomography images obtained at cancer diagnosis and 1 month later before treatment. The prognostic value of body composition indexes at diagnosis and the changes in those indexes over 1 month was then evaluated. Results In total, 45 patients (81.8%) received chemotherapy, chemoradiation, or radiation therapy, whereas the remaining patients underwent BSC. There were 27 patients (49.1%) who had low SMI at cancer diagnosis. Univariate analysis showed no significant associations between the baseline body composition indexes including SMI, VATI, SATI, and VSR and survival. Meanwhile, male sex (HR, 2.79; 95% CI, 1.16–6.71, p = 0.022) and higher decrease in VATI over 1 month (HR, 2.41; 95% CI, 1.13–5.13, p = 0.023) were identified as independent risk factors for mortality in multivariate analysis. Conclusion Rapid decline in VAT over 1 month is closely associated with poorer survival in unresectable advanced pancreatic cancer. A short‐term assessment of body composition changes may be a rational approach to predict prognosis in these patients.

Abstract Objectives Diversion colitis (DC) is an inflammatory disorder caused by interruption of the fecal stream and subsequent nutrient deficiency from luminal bacteria. The utility of fecal microbiota transplantation (FMT) for DC was recently investigated; however, the precise pathogenesis of this condition remains unclear. This study aimed to evaluate the utility of autologous FMT in DC and to determine the related changes in the intestinal microbiota. Methods Autologous FMT was performed to reestablish the intestinal microbiota in five patients (average age, 64.6 ± 8.3 years) with DC. They underwent double‐ended colostomy. We assessed the diverted colon by endoscopy and evaluated the microbiota before and after FMT using the 16S rRNA gene sequencing method. Results All five patients had mild inflammation (ulcerative colitis endoscopic index of severity [UCEIS] 2–3) in the diverted colon based on the colonoscopic findings. Three patients presented with symptoms, such as tenesmus, mucoid stool, and bloody stool. With FMT treatment, all patients achieved endoscopic remission (UCEIS score of 0 or 1) and symptomatic improvement. We observed a significantly decreased α‐diversity in DC patients compared to healthy controls. The frequency of aerobic bacteria, such as Enterobacteriaceae, in the diverted colon decreased after autologous FMT. Conclusions This study was the first to show that the microbiota in the diverted colon was significantly affected by autologous FMT. Since interruption of the fecal stream is central to the development of DC, FMT can be considered a promising treatment.

Abstract A 64‐year‐old woman was receiving oral methotrexate (MTX) for rheumatoid arthritis (RA) for 15 years. She underwent esophagogastroduodenoscopy because of discomfort in the chest. Endoscopic findings revealed an ulcer in the lower esophagus extending to the gastroesophageal junction (EGJ). The ulcer occupied half of the esophageal lumen and had a sharp and clear margin. Magnifying narrow‐band imaging endoscopy revealed the deposition of white plaque, and there were few microvessels in the edge and bottom of the ulcer. Histologic examination of the biopsy specimens from the oral edge of the lesion revealed proliferation of atypical lymphoid cells (immunophenotype results: CD20 [+], CD3 [partially +], CD5 [−], and BCL‐2 [−]]. The patient was diagnosed with methotrexate‐associated lymphoproliferative disorder (MTX‐LPD) and was advised to stop MTX intake. After 2 months of stopping MTX, the ulcer was found to be almost regressed and showed signs of healing. MTX‐LPD in the lower esophagus extending to the EGJ is extremely rare. This case can help in expanding the understanding of esophageal MTX‐LPD.

The incidence of gastric tube carcinoma (GTC) after esophagectomy for esophageal carcinoma has increased in recent years. Surgical removal of the reconstructed gastric tube is associated with high mortality, and endoscopic submucosal dissection (ESD) is a promising alternative. There are limited reports of ESD for GTC. This study investigated the efficacy and safety of ESD in GTC. This single-center retrospective study examined patients who underwent ESD for GTC after esophagectomy at our institution between 2003 and 2018. The curability of GTC with ESD was evaluated histologically according to the Japanese Gastric Cancer Treatment Guidelines. Patient characteristics and procedural and long-term outcomes were analyzed. Overall, 31 patients (29 men and 2 women; median age, 73 years) with 45 GTC lesions underwent ESD. The mean period between primary esophagectomy and the diagnosis of GTC was 10.6 years. Bleeding during ESD was noted in two patients (6.5%). No other adverse or fatal events such as perforation were noted. Complete resection and curative resection were documented in 80.6% and 48.4% of cases, respectively. The 3-year and 5-year overall survival rates were 67.6% and 47.7%, respectively. The 3-year and 5-year disease-specific survival rates were 100% and 92.9%, respectively. One patient died of GTC, and fourteen patients died of other diseases, including primary carcinoma in five cases. ESD was safe and provided good long-term outcomes in patients with GTC. Regular long-term gastroscopy is required for the early detection of GTC. Patients with GTC after esophagectomy for esophageal carcinoma have a high risk of other primary carcinomas or comorbidities after ESD.

Overt hepatic encephalopathy (HE) is one of the complications of liver cirrhosis (LC), which negatively affects the prognosis and quality of life of patients. Small intestinal bacterial overgrowth (SIBO) is significantly associated with LC and its complications, including HE. We investigated the relationship between SIBO and LC, and the difference between hydrogen-producing and methane-producing SIBO (H-SIBO and M-SIBO, respectively). This is a prospective cohort study of 107 cases. Breath measurements of hydrogen and methane concentrations were performed for the diagnosis of SIBO. The study cohort included 81 males with a median age of 70 (40-86) years, and SIBO was detected in 31 cases (29.0%). There were no significant differences between the SIBO positive and SIBO negative groups. Reclassification into H-SIBO (16 cases) and others (91 cases) was performed, and the Child-Pugh score was only derived in the multivariate logistic analysis (P = 0.028, odds ratio 1.39, 95% confidence interval 1.04-1.85). Furthermore, H-SIBO was significantly associated with covert HE in chi-square test (50.0% vs. 24.2%, P = 0.034). In addition, we evaluated the therapeutic response on SIBO of rifaximin in eight covert HE patients. 20% patients with M-SIBO and 67% patients with H-SIBO showed an improvement of the breath test. In conclusion, H-SIBO, but not M-SIBO, is significantly associated with liver function, and rifaximin might be more effective for covert HE with H-SIBO. Therefore, the diagnosis of SIBO, including the classification as H-SIBO and M-SIBO, might help to determine the choice of treatment for HE.

Abstract This report highlights the easy peeling of the esophageal epithelium with Nikolsky phenomenon after swallowing the foreign body and the healing status of the esophagus only 3 days later in a patient of pemphigus vulgaris.

Introduction: Triamcinolone acetonide (TA), a steroid, is often used clinically to prevent dysfunctions associated with fibrosis. The objective of this study was to examine whether TA can be suspended in a gelatin sheet for tissue engineering using a mouse skin wound model. Methods: TA was suspended in biodegradable gelatin and freeze-dried in a sheet form. The sheet was analyzed for homogeneity and controlled release of TA by high-performance liquid chromatography. We made two skin wounds on the dorsal side of mice. Gelatin sheets with TA (TA sheet) and without TA (control sheet) were attached to each skin wound. To determine the efficacy of the prepared TA sheet on the skin wounds, TA-sheet versus TA-injection experiments were conducted. Hematoxylin and eosin staining was performed to assess the grade of epithelialization and alpha smooth muscle actin (α-SMA) immunohistochemical staining was conducted to evaluate myofibroblast infiltration. Results: In the TA-release test in vitro, 7.7 ± 2.3% of TA was released from the sheet by 24 h. After replacing the initial phosphate-buffered saline (PBS) with collagenase PBS, the amount of released TA increased over time. The wound area/original skin wound area after 15 days with the TA sheet was significantly larger than that with the control sheet (26.9 ± 5.5% vs 10.7 ± 2.6%, p = 0.023). The α-SMA positive area/whole area with the TA sheet was significantly lower than that with the control sheet (4.65 ± 0.66% vs 7.24 ± 0.7%, p = 0.023). Furthermore, the α-SMA positive area/whole area with the TA sheet was significantly lower than that with TA injection (5.32 ± 0.45% vs 7.93 ± 0.75%, p = 0.013). Conclusions: We developed a TA sheet and confirmed both the homogeneity of the suspended TA and controlled-release of the TA in the presence of collagenase in vitro. The TA sheet caused less myofibroblast infiltration into the tissue than the control sheet or TA injection did. Keywords: Fibrosis, Triamcinolone acetonide, Drug delivery systems, Gelatin, Biodegradable

A 40-year-old man with slightly depressed (0-IIc) type gastric cancer of the pyloric anterior gastric area underwent pre-operative screening for tetralogy of Fallot and endoscopic submucosal dissection (ESD) and was tested for Helicobacter pylori antigens and antibodies. Both tests were negative. He did not have a history of eradication. Pathological diagnosis of ESD showed a well-differentiated adenocarcinoma. The tumor was CD10-positive, MUC5AC-negative, and MUC6-confocal positive; it showed differentiation with gastrointestinal phenotype. Moreover, the tumor cells were lysozyme-positive, resembling Paneth cells. Mucosal glands exhibited intestinal metaplasia on the anal side of the tumor lesion. On the oral side of the tumor, metaplasia was non-existent, with normal pyloric glands present in the mucosal layer. The patient was not infected with H. pylori; however, intestinal metaplasia existed around the early gastric cancer. This suggested that the intestinal metaplasia occurred due to bile reflux, and the gastric neoplasia arose with the metaplasia without an H. pylori infection. This case may potentially help explain gastric cancer development in the absence of H. pylori infection.

It is reported that an increase in aerobic bacteria, a lack of short-chain fatty acids (SCFAs), and immune disorders in the diverted colon are major causes of diversion colitis. However, the precise pathogenesis of this condition remains unclear. The aim of the present study was to examine the microbiota, intestinal SCFAs, and immunoglobulin A (IgA) in the diverted colon. Eight patients underwent operative procedures for colostomies. We assessed the diverted colon using endoscopy and obtained intestinal samples from the diverted colon and oral colon in these patients. We analyzed the microbiota and SCFAs of the intestinal samples. The bacterial communities were investigated using a 16S rRNA gene sequencing method. The microbiota demonstrated a change in the proportion of some species, especially Lactobacillus, which significantly decreased in the diverted colon at the genus level. We also showed that intestinal SCFA values were significantly decreased in the diverted colon. Furthermore, intestinal IgA levels were significantly increased in the diverted colon. This study was the first to show that intestinal SCFAs were significantly decreased and intestinal IgA was significantly increased in the diverted colon. Our data suggest that SCFAs affect the microbiota and may play an immunological role in diversion colitis.

Alpha-fetoprotein (AFP)-L3 was originally reported as a hepatocellular carcinoma (HCC)-specific tumor marker, and recent accumulation of evidence has revealed that AFP-L3 frequency predicts the biological malignancy potential of HCC. However, AFP-L3 elevation from undetectable levels after curative treatment could not be discussed due to the difficulties of calculating AFP-L3 concentrations when serum AFP levels were low. Here, as a novel method, we used highly sensitive AFP-L3 frequency to predict HCC recurrence after curative treatment. Our cases illustrate that recognizing elevation of AFP-L3 from undetectable levels led to the early detection of recurrent HCC due to more careful surveillance.

Background and study aims Several previous reports indicate that endoscopic injection of triamcinolone acetonide (TA) after widespread endoscopic submucosal dissection (ESD) is effective for preventing esophageal stricture. We investigated the efficacy of injecting TA in two sessions for preventing stricture formation post-ESD. Patients and methods Sixty-six consecutive patients with widespread mucosal defects that affected more than three-fourths of the circumference of the esophagus were included. The study group (n = 40) received TA injections over two sessions: immediately after and 14 days after ESD. The control group (n = 26) did not receive a TA injection. This study was performed retrospectively against historical controls. The primary endpoint of this study was frequency of stricture after TA injection. The secondary endpoint was number of required endoscopic balloon dilations (EBDs) after TA injection. Results The post-ESD stricture rate among patients who had subcircumferential mucosal defects was 45.7 % in the study group (16/35 patients), which was significantly lower than the rate of 73.9 % in the control group (17/23 patients; P = 0.031). The number of EBD procedures required was significantly lower in the study group (median 0, range 0 – 7) than in the control group (median 4, range 0 – 20; P

Hepatocellular carcinomas (HCCs), which often arise from chronic liver damage, have poor conditional 5-year survival and are recognized as heterogeneous tumors. Considering the heterogeneity of HCCs, diverse perspectives need to be addressed for treating such tumors, besides the findings of conventional imaging modalities and tumor markers. Data from the latest technologies, such as liquid biopsy, and the detection of the presence of cancer cells with stem/progenitor cell markers, gene mutations and diverse pathways, crosstalk with immune cells and cancer-associated fibroblasts, and mechanisms of epithelial–mesenchymal transition provide diverse lines of information. Integration of these data with clinical data might be necessary to develop effective therapies for precision medicine. Here, we review several aspects of dealing with the complexity of heterogeneous HCCs.

Achalasia is an esophageal motility disorder characterized by impaired lower esophageal sphincter (LES) relaxation. On high-resolution manometry (HRM), impaired LES relaxation is defined by elevated integrated relaxation pressure (IRP). However, a new category of achalasia within the normal IRP range has been suggested.HRM was performed using a Starlet device and an IRP threshold of 26 mmHg. Peroral endoscopic myotomy (POEM) was performed for cases of achalasia diagnosed using established methods. During POEM, the histology of the LES was assessed. Follow-up was performed 2 months post-operatively.Forty-one patients with achalasia (18 women, mean age 53 ± 18.6 years) were included. Among them, 27 were placed in the IRP > 26 mmHg subgroup (impaired LES relaxation on HRM) and 14 in the IRP ≤ 26 mmHg subgroup (normal LES relaxation on HRM). In the IRP ≤ 26 mmHg subgroup, patients were older, had longer symptom duration, and had more esophageal dilation. The IRP ≤ 26 mmHg subgroup had the same symptom severity as the higher IRP subgroup and POEM significantly improved symptoms and IRP, although four patients still had severe LES fibrosis.The clinical presentation of achalasia has a gap between a HRM-defined impaired LES relaxation, with aging or disease progression considered reasons for a lowered LES pressure. POEM can be a feasible treatment option, even for cases of achalasia with a normal IRP. However, patients with severe LES fibrosis need more attention for the therapeutic indication.

Abstract Although linear mucosal tears have been reported, we found a relatively rare case of wavy mucosal tear in collagenous colitis. This may be related to the mutual weak adhesiveness between the epithelium and collagen band. This complication necessitates great care to be taken while performing colonoscopy in patients suspected of collagenous colitis.

Background. Dentures and dental instruments are frequently encountered ingested foreign bodies. The aim of the present study was to assess the safety and efficacy of endoscopically removing ingested dental objects. Methods. Twenty-nine consecutive patients with 29 dental objects who were treated at the Niigata University Medical and Dental Hospital from August 2009 to December 2015 were retrospectively reviewed. Characteristics of the patients and the ingested dental objects, the clinical features and findings of radiological imaging tests, and outcomes of endoscopic removal were analyzed. Results. Patients’ mean age was 62.9±21.0 years. The ingested dental objects included 23 dentures (13 crowns, 4 bridges, 4 partial dentures, and 2 other dentures) and 6 dental instruments. Twenty-seven upper gastrointestinal endoscopies and 2 colonoscopies were performed, and their success rates were 92.6% and 100%, respectively. There were 2 cases of removal failure; one case involved an impacted partial denture in the cervical esophagus, and this case required surgical removal. Conclusions. Endoscopic removal of ingested dentures and dental instruments is associated with a favorable success rate and acceptable complications. The immediate intervention and appropriate selection of devices are essential for managing ingested dental objects.

Induction of mucosal healing (MH) is an important treatment goal in inflammatory bowel disease (IBD). Although the molecular mechanisms underlying MH in IBD is not fully explored, local fibrosis would contribute to interfere mucosal repair. Carbohydrate sulfotransferase 15 (CHST15), which catalyzes sulfation of chondroitin sulfate to produce rare E-disaccharide units, is a novel mediator to create local fibrosis. Here we have used siRNA-based approach of silencing CHST15 in dextran sulfate sodium (DSS) induced colitis in mice, human colon fibroblasts and cancer cell lines. In a DSS-induced acute colitis model, CHST15 siRNA reduced CHST15 mRNA in the colon, serum IL-6, disease activity index (DAI) and accumulation of F4/80+ macrophages and ER-TR7+ fibroblasts, while increased Ki-67+ epithelial cells. In DSS-induced chronic colitis models, CHST15 siRNA reduced CHST15 mRNA in the colon, DAI, alpha-smooth muscle actin+ fibroblasts and collagen deposition, while enhanced MH as evidenced by reduced histological and endoscopic scores. We also found that endoscopic submucosal injection achieved effective pancolonic delivery of CHST15 siRNA in mice. In human CCD-18 Co cells, CHST15 siRNA inhibited the expression of CHST15 mRNA and selectively reduced E-units, a specific product biosynthesized by CHST15, in the culture supernatant. CHST15 siRNA significantly suppressed vimentin in both TGF-ß-stimulated CCD18-Co cells and HCT116 cells while up-regulated BMP7 and E-cadherin in HCT116 cells. The present study demonstrated that blockade CHST15 represses colonic fibrosis and enhances MH partly though reversing EMT pathway, illustrating a novel therapeutic opportunity to refractory and fibrotic lesions in IBD.

Bezoars are relatively rare foreign bodies of gastrointestinal tract and often cause ileus and ulcerative lesions in the stomach and subsequent bleeding and perforation due to their size and stiffness. Therefore, the removal of bezoars is essential and recent development of devices, the endoscopic removal procedure, is often applied. However, due to their stiffness, simple endoscopic removal failed in not a few cases, and surgical removal has also been used. Recently, the efficacy of a combination therapy of endoscopic procedure and dissolution using carbonated liquid has been reported. To develop the safe and effective removal procedure, we carefully reviewed a total of 55 reported cases in this study including our 3 additional cases, successfully treated with dissolution with endoscopic fragmentation. In summary, the data showed the efficiency in the combination therapy, treating the larger size of bezoar and reducing the length of hospital stay. To the best of our knowledge, this is the largest pragmatical and clinical review for the combination therapy of dissolution and endoscopic treatment for bezoars. This review should help physicians to manage bezoars more efficiently.

Background/Aim: Transarterial chemoembolization (TACE) is the standard treatment for patients with hepatocellular carcinoma in the intermediate stage; however, with advances in systemic therapy, the indications for TACE have gained significance. While lenvatinib (LEN)-TACE offers the potential for good outcomes, local recurrence has not yet been adequately investigated. Therefore, this study investigated local recurrence factors for each type of TACE, focusing on the lipiodol (Lip) value in LEN-TACE and conventional TACE. Patients and Methods: Fifty patients (50 nodes) with hepatocellular carcinoma and a tumor size <7 cm who underwent LEN-TACE or TACE between January 2022 and June 2023 were included in this study to investigate local recurrence and its influencing factors. Results: The local recurrence rate after LEN-TACE was 5.6% at 6 months and 11.5% at 12 months, whereas those after TACE were 6.4% at 6 months and 13.2% at 12 months (p=0.028). There were no significant differences in local recurrence rates according to background liver factors, alpha-fetoprotein (AFP), des-γ-carboxy prothrombin (DCP) values, sex, age, and albuminbilirubin (ALBI) score. Lipiodol (Lip) values immediately after LEN-TACE were significantly higher than those after TACE alone (p=0.021). Multivariate analysis showed that LEN-TACE had a recurrence hazard ratio of 0.184. Conclusion: LEN-TACE provided good local tumor control. Local recurrence factors included LEN pretreatment, and Lip CT values were higher immediately after LEN-TACE. Thus, LEN-TACE after upfront LEN administration may increase the effectiveness of TACE. [ABSTRACT FROM AUTHOR]

Background/Aim: Ablating a spherical area during hepatocellular carcinoma ablation therapy is a very important issue. We aimed to determine the ablation area of bovine liver using various radiofrequency ablation (RFA) protocols. Materials and Methods: Bovine liver (1-2 kg) was placed in an aluminum tray, which was punctured with STARmed VIVA 2.0 17-gauge (G) and 15-G electrodes using a current-carrying tip. Under the step-up or linear method, with an ablation time up to one break and RFA output stop, the size of the color change area (representing the thermally coagulated area) of the bovine liver was measured along the vertical and horizontal axes, and the ablated volume and total heat generated were calculated. Results: 5-W per minute increases protocol resulted in greater horizontal and vertical diameters of the ablated area than 10-W per minute increases protocol under the step-up method. For 5-W and 10-W per minute increases under the step-up method, the aspect ratio was 0.81 and 0.67 with a 17-G electrode, and 0.73 and 0.69 with a 15-G electrode, respectively. For 5-W and 10-W increases under the linear method, the aspect ratio was 0.89 and 0.82, respectively. Sufficient ablation was obtained, with vertical and horizontal diameters of 50 mm and 43.50 mm, respectively. Although the ablation time was long, the watt output value at the break and average watt value were low. Conclusion: Gradual increase in output (5 W) using the step-up method yielded a more spherical ablation area, and longer ablation time in the linear method with a 15-G electrode could result in a more spherical ablation area in real clinical practice in humans. Future studies should examine concerns regarding long ablation times. [ABSTRACT FROM AUTHOR]