Global trends in incidence and prevalence of achalasia, 1925-2021: A systematic review and meta-analysis

BACKGROUND

Achalasia poses a significant socioeconomic burden, yet global trends remain undocumented. This study aims to describe the worldwide trends in the incidence and prevalence of achalasia from 1925 to 2021 and explore their correlation with various factors through a comprehensive systematic review.

METHODS

We searched the PubMed/MEDLINE, Embase, and Cochrane databases from inception to 30 June 2023, to identify studies reporting the incidence or prevalence of achalasia in the general population. This study utilized pooled estimates with 95% confidence intervals (CI) to estimate the incidence and prevalence of achalasia, and conducted various subgroup analyses.

RESULTS

A total of 26 eligible studies covering approximately 269 million participants and 20,873 patients from 14 countries across five continents were included. Global pooled incidence and prevalence of achalasia were estimated to be 0.78 cases per 100,000 person-years (95% CI, 0.64-0.93; number of studies, 26; sample population, 269,315,171) and 10.82 cases per 100,000 person-years (95% CI, 8.15-13.48; number of studies, 14; sample population, 192,176,076), respectively. The incidence of achalasia was higher in Oceania (than Asia and Africa) and in adults (than children) after the introduction of the Chicago classification. Prevalence followed a similar pattern. The pooled incidence of achalasia showed an overall upward trend from 1925 to 2021 (1925-1999; 0.40 [0.32-0.49] vs. 2018-2021; 1.64 [1.33-1.95] cases per 100,000 person-years).

CONCLUSIONS

The incidence and prevalence of achalasia have notably increased, particularly with advancements in diagnosis, and show significant variation worldwide, despite the large heterogeneity within the sample population. Further studies are necessary to accurately assess the global incidence and prevalence of achalasia.

Inhibition of GLI Transcriptional Activity and Prostate Cancer Cell Growth and Proliferation by DAX1

The Hedgehog (Hh) signaling pathway plays an essential role in the initiation and progression of prostate cancer. This is mediated by transcriptional factors belonging to the GLI (glioma-associated oncogene) family, which regulate downstream targets to drive prostate cancer progression. The activity of GLI proteins is tightly controlled by a range of mechanisms, including molecular interactions and post-translational modifications. In particular, mitogenic and oncogenic signaling pathways have been shown to regulate GLI protein activity independently of upstream Hh pathway signaling. Identifying GLI protein regulators is critical for the development of targeted therapies that can improve patient outcomes. This study aimed to identify a novel protein that directly regulates the activity of GLI transcription factors in prostate cancer. We performed gene expression, cellular analyses, and reporter assays to demonstrate that DAX1 (dosage-sensitive sex reversal adrenal hypoplasia congenital critical region on X chromosome, gene 1) interacts with GLI1 and GLI2, the master regulators of Hh signaling. Interestingly, DAX1 overexpression significantly inhibited Hh signaling by reducing GLI1 and GLI2 activity, prostate cancer cell proliferation, and viability. Our results shed light on a novel regulatory mechanism of Hh signaling in prostate cancer cells. The interaction between DAX1 and GLI transcription factors provides insight into the complex regulation of Hh signaling in prostate cancer. Given the importance of Hh signaling in prostate cancer progression, targeting DAX1-GLI interactions may represent a promising therapeutic approach against prostate cancer. Overall, this study provides new insights into the regulation of the Hh pathway and its role in prostate cancer progression. The findings suggest that DAX1 could serve as a potential therapeutic target for the treatment of prostate cancer.

Effects of Mesenchymal Stem Cells Treatment on Radiation-Induced Proctitis in Rats

PURPOSE

There are no effective treatment methods with which to control complications of radiation proctitis with fistula or recurrent bleeding following radiation treatment for prostate, cervical, or rectal cancer. Mesenchymal stem cells (MSCs) can induce immune modification, resulting in tissue repair and regeneration. Therefore, we used a rat model of radiation-induced proctitis and observed the effects of using human placenta-derived (PD) and adipose tissue-derived (AD) MSCs.

MATERIALS AND METHODS

Female Sprague Dawley rats were irradiated at the pelvic area with 25 Gy. We injected 1×10⁶ cells of human PD-MSCs, human AD-MSCs, human foreskin fibroblasts, and control media into the rectal submucosa following irradiation. We sacrificed rats for pathologic evaluation.

RESULTS

Fibrosis on the rectum was reduced in both MSC groups, compared to the control group. Mucosal Ki-67 indices of both MSC injected groups were higher than those in the control group. Although caspase-3 positive cells in the mucosa gradually increased and decreased in the control group, those in both MSC injected groups increased rapidly and decreased thereafter.

CONCLUSION

We demonstrated the effects of regional MSC injection treatment for radiation-induced proctitis in rats. MSC injection reduced fibrosis and increased proliferation in rat mucosa. Human AD-MSCs and PD-MSCs had similar effectiveness.

A modified endoscopic full thickness resection for gastric subepithelial tumors from muscularis propria layer: Novel method

BACKGROUND AND AIM

The removal of subepithelial tumors (SETs) is challenging, particularly in tumors originating from the muscularis propria (MP) in the upper gastrointestinal (GI) tract, owing to the high risk of perforation. We developed mechanical spray lumpectomy (MSL), which is a novel method to safely and easily remove the tumor. This study aimed to evaluate the feasibility and safety of MSL as a novel endoscopic treatment for gastric subepithelial lesions.

METHODS

We performed MSL in a total of 13 patients with upper GI SETs originating from the MP layer. First, mucosectomy was performed using a conventional snare. Repeated injections were performed towards the subserosal layer. After injection, the lesion was mechanically pushed to separate the MP layer using an endoscopic cap. Finally, the mucosa, submucosa, and MP layer with SETs were completely dissected using the spray coagulation mode, and the remaining defect was closed with clipping.

RESULTS

All tumors were completely resected. The mean procedure time was 84.38 ± 41.73 min. There were four leiomyomas, six GI stromal tumors, one mucosa-associated lymphoid tissue lymphoma, and two ectopic pancreases. Although small perforation occurred in only one case, the defect was successfully closed using hemostatic clipping. Moreover, no serious complications related to MSL were encountered during or after the procedure. No residual lesion or recurrence was observed during the follow-up period.

CONCLUSIONS

Mechanical spray lumpectomy can be a novel method that provides a safe and minimally invasive endoscopic treatment for upper GI SETs originating from the MP layer.

The Usefulness of the Measurement of Esophagogastric Junction Distensibility by EndoFLIP in the Diagnosis of Gastroesophageal Reflux Disease

Background/Aims

Increased esophagogastric junction (EGJ) relaxation is the most important mechanism involved in gastroesophageal reflux disease (GERD). An endoscopic functional luminal imaging probe (EndoFLIP^Ⓡ) is a device used to quantify EGJ distensibility in routine endoscopy. The aim of the current study was to assess the usefulness of EndoFLIP^Ⓡ for the diagnosis of GERD compared to normal controls.

Methods

We analyzed EndoFLIP^Ⓡ data from 204 patients with erosive reflux disease (ERD), 310 patients with nonerosive reflux disease (NERD), and 277 normal subjects. EndoFLIP^Ⓡ uses impedance planimetry to measure 16 cross-sectional areas (CSAs) in conjunction with the corresponding intrabag pressure within a 4.6 cm cylindrical segment of a fluid-filled bag. The EGJ distensibility was assessed using 40 mL volume-controlled distensions.

Results

The mean distensibility index values were 13.98 mm²/mm Hg in ERD patients, 11.42 mm²/mm Hg in NERD patients, and 9.1 mm²/mm Hg in normal subjects. There were significant differences in EGJ distensibility among the three groups (p<0.001). In addition, the CSAs were significantly higher in the ERD (291.03±160.77 mm²) and NERD groups (285.87±155.47 mm²) than in the control group (249.78±144.76 mm², p=0.004). We determined the distensibility index cutoff value of EGJ as 10.95 for the diagnosis of GERD by receiver operating characteristic curve analysis.

Conclusions

The EGJ distensibilities of GERD patients were higher than those of normal subjects, regardless of the presence of reflux esophagitis. Thus, the measurement of EGJ distensibility using the EndoFLIP^Ⓡ system could be useful in the diagnosis of GERD.

Characteristics of a Subset of Achalasia With Normal Integrated Relaxation Pressure

Background/Aims

Integrated relaxation pressure (IRP) is a critical diagnostic criterion to define achalasia. However, there are some cases with typical symptoms and signs of achalasia but with normal IRP. The aim of this study is to evaluate the clinical characteristics of patients with achalasia with normal IRP and outcomes after peroral endoscopic myotomy (POEM).

Methods

Patients with achalasia were collected in whom POEM was performed from November 2014 to April 2018 at CHA Bundang Medical Center. Achalasia with normal IRP was defined by findings compatible to achalasia in Eckardt score, endoscopy with endoscopic ultrasound, high-resolution manometry, impedance planimetry (EndoFlip), and timed esophagogram.

Results

POEM was performed in 89 patients with achalasia; among them, 24 (27%) patients were diagnosed with achalasia with normal IRP. Patients with achalasia with normal IRP were older, had longer duration of symptom, and had a more tortuous esophagus. In EndoFlip, the distensibility index and cross-sectional area were higher in patients with normal IRP. Therapeutic outcomes showed no statistically significant differences. On correlation analysis, IRP had negative correlations with age, disease duration, and distensibility index.

Conclusions

Patients with achalasia of normal IRP value were older and had longer disease duration and higher distensibility index and cross-sectional area than patients with achalasia with abnormal relaxation of lower esophageal sphincter. Therapeutic outcomes were not different between the 2 groups.

Utility of EUS elastography in the diagnosis of gastric subepithelial tumors: a pilot study (with video)

BACKGROUND AND AIMS

EUS elastography is a real-time imaging technique that analyzes tissue elasticity. The aim of this study was to investigate the applicability of quantitative EUS elastography in the differential diagnosis of gastric subepithelial tumors (SETs).

METHODS

We prospectively registered 41 consecutive patients with gastric SETs and measured their strain ratios with EUS elastography. The strain ratios of gastric SETs were compared with the histopathologic diagnosis.

RESULTS

Thirty-one patients (mean age, 51.4 ± 12.6 years) were included in the analysis. The mean size of the SETs was 2.3 ± 0.7 cm. Lipomas had the lowest strain ratio of 1.6 (1.1-2.0), followed by leiomyomas 6.0 (2.0-29.0), ectopic pancreas 11.8 (1.7-29.3), gastrointestinal stromal tumors (GISTs) 51.1 (29.0-67.0), and schwannomas 62.0. With a cut-off value of 22.7, EUS elastography could differentiate GISTs from leiomyomas with sensitivity and specificity of 100% and 94.1%, respectively (P = .001; 95% confidence interval, 0.979-1.000).

CONCLUSIONS

EUS elastography could be a promising diagnostic adjunct for the assessment of gastric SETs, especially in differentiating GISTs from leiomyomas.

Dietary threonine prevented stress-related mucosal diseases in rats

Stress-related mucosal disease (SRMD), or stress ulceration, is a group of conditions ranging from stress-related superficial gastric mucosal damage to deep gastric ulcers that are primarily correlated with mucosal ischemia, and pharmacologic interventions that optimize tissue perfusion or preserve defensive mucus aim to decrease the occurrence of conditions, such as gastric acidity, or enhance gastric defenses. However, the identification of multifactorial pathogenesis may be effective in preventing SMRD, and the use of stress prophylaxis is generally preferred. Since threonine is a component in the polymerization and synthesis of gastric mucin and possibly enhanced defense actions and lignin may provide structural support for defense and antioxidative function, we hypothesized that dietary intake of threonine and/or lignin can enhance defense against SRMD. The water immersion-restraint stress (WIRS) was used in rats and additional groups were pretreated with threonine alone or the combination of threonine and lignin. Based on gross and microscopic evaluations, threonine alone or the combination of threonine and lignin, a natural antioxidant, significantly reduced the development of SRMD (P < 0.05). According to molecular explorations, the levels of inflammatory mediators, such as interleukin (IL)-8, IL-6, IL-1β, inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ), all of which are mediators that play a significant role in controlling WIRS, significantly decreased in the groups pretreated with either threonine alone or the combination of threonine and lignin (P < 0.01). WIRS significantly increased apoptosis in the stomach. However, the apoptotic index significantly decreased with threonine pretreatment. According to periodic acid Schiff staining results, the expression of gastric mucin was significantly preserved in groups pretreated with threonine but remarkedly decreased in the WIRS group. The gastric heme oxygenase-1 levels significantly increased in the group treated with threonine. In conclusion, the dietary intake of threonine or the combination of threonine and lignin is effective in preventing SRMD.

Umbilical cord/placenta-derived mesenchymal stem cells inhibit fibrogenic activation in human intestinal myofibroblasts via inhibition of myocardin-related transcription factor A

Background

The lack of anti-fibrotic agents targeting intestinal fibrosis is a large unmet need in inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis. Previous studies have found that perinatal tissue (umbilical cord, UC; placenta, PL)-derived mesenchymal stem cells (MSCs) reduce fibrosis in several organs. However, their effects on human intestinal fibrosis are poorly understood. This study investigated the anti-fibrogenic properties and mechanisms of MSCs derived from UC and PL (UC/PL-MSCs) on human primary intestinal myofibroblasts (HIMFs).

Methods

The HIMFs were treated with TGF-β1 and co-cultured with UC/PL-MSCs. We used a small molecular inhibitor CCG-100602 to examine whether serum response factor (SRF) and its transcriptional cofactor myocardin-related transcription factor A (MRTF-A) are involved in TGF-β1-induced fibrogenic activation in HIMFs. The anti-fibrogenic mechanism of UC/PL-MSCs on HIMFs was analyzed by detecting the expression of RhoA, MRTF-A, and SRF in HIMFs.

Results

UC/PL-MSCs reduced TGF-β1-induced procollagen1A1, fibronectin, and α-smooth muscle actin expression in HIMFs. This anti-fibrogenic effect was more apparent in the UC-MSCs. TGF-β1 stimulation increased the expressions of RhoA, MRTF-A, and SRF in the HIMFs. TGF-β1 induced the synthesis of procollagen1A1, fibronectin, and α-smooth muscle actin through a MRTF-A/SRF-dependent mechanism. Co-culture with the UC/PL-MSCs downregulated fibrogenesis by inhibition of RhoA, MRTF-A, and SRF expression.

Conclusions

UC/PL-MSCs suppress TGF-β1-induced fibrogenic activation in HIMFs by blocking the Rho/MRTF/SRF pathway and could be considered as a novel candidate for stem cell-based therapy of intestinal fibrosis.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1385-8) contains supplementary material, which is available to authorized users.

Combination Therapy with a PI3K/mTOR Dual Inhibitor and Chloroquine Enhances Synergistic Apoptotic Cell Death in Epstein-Barr Virus-Infected Gastric Cancer Cells

The phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway is a promising target for gastric cancer (GC) treatment; however the efficacy of PI3K/mTOR dual inhibitors in GC has not yet been maximized. Additionally, the effect of autophagy regulation by PI3K/mTOR dual inhibitors has not been clearly elucidated in GC treatment. We aimed to show that our newly developed PI3K/mTOR dual inhibitor, CMG002, when combined with an autophagy inhibitor, chloroquine (CQ), potently induces effective cancer cell death in Epstein–Barr virus (EBV)-associated gastric cancer (EBVaGC) cells, where both the PI3K/AKT/mTOR and autophagy pathways play important roles in disease pathogenesis. EBV- and mock-infected AGS and NUGC3 GC cell lines were treated with CMG002 +/− CQ. PI3K/AKT/mTOR signaling pathway mediators, cellular apoptosis and autophagy markers were confirmed by Western blot assay. Cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay. CMG002 effectively blocked the PI3K/AKT/mTOR pathway by markedly decreasing phosphorylation of AKT and its downstream mediator S6. CMG002 induced G0/G1 cell cycle arrest and enhanced apoptotic cell death in AGS and NUGC3 cells, particularly EBV-infected cells compared with mock-infected cells, as confirmed by flow cytometric analyses and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assays. The combination of CMG002 plus CQ synergistically increased apoptotic cell death in EBV-infected GC cell lines when compared with CMG002 alone (P < 0.05). Our results suggest that the new PI3K/mTOR dual inhibitor, CMG002, when used in combination with the autophagy inhibitor, CQ, provides enhanced therapeutic efficacy against EBVaGC.

Effectiveness of Autologous Platelet-Rich Plasma for the Healing of Ulcers after Endoscopic Submucosal Dissection

Background/Aims

Platelet-rich plasma (PRP) has been used for wound healing in various medical fields. The aim of this study was to evaluate the clinical efficacy and safety of local PRP injections after endoscopic submucosal dissection (ESD).

Methods

Patients were non-randomly divided into the following two groups: (1) control group in which patients were administered only an intravenous proton pump inhibitor (PPI), and (2) a study group in which patients were administered an intravenous PPI and a topical PRP injection. We assessed the reduction in the ulcer area and stage of the ulcer after the procedure (24 hours, 48 hours, and 28 days after endoscopic surgery).

Results

We enrolled 7 study and 7 control patients. In the study group, the rate of ulcer reduction was 59% compared to 52% in the control group (p=0.372), 28 days after ESD. There were 5 patients in the S stage and 2 patients in the H stage in the study group compared to no patient in the S stage and 7 patients in the H stage in the control group (p=0.05), 28 days after ESD. There were no serious complications in either group.

Conclusions

The local injection of PRP is a safe and effective procedure for ulcer healing after ESD.

Periodontitis is associated with an increased risk for proximal colorectal neoplasms

Interval colorectal cancers detected after colonoscopy are known to be highly associated with proximal colorectal neoplasms (CRNs). This cross-sectional study investigated whether periodontitis could be a risk factor for proximal CRNs in healthy individuals. A total of 2504 subjects who received a colonoscopy and dental exam were enrolled in this study. We divided the subjects into the periodontitis group (n = 216) and the control group (n = 2288). The periodontitis group was defined as subjects who had one or more teeth with a probing pocket depth (PPD) ≥4 mm. The prevalence of proximal CRNs was significantly higher in the periodontitis group (25.0%) than in the control group (12.3%) (P < 0.001). Independent risk factors for proximal CRNs in the multivariate analysis were periodontitis, smoking, age, waist circumference, and triglycerides, and those for proximal advanced CRNs were periodontitis, age, and family history of CRC. However, periodontitis was not a risk factor for overall CRNs and advanced CRNs. Periodontitis was associated with an increased risk of proximal CRNs (odds ratio [OR], 1.525; 95% confidence intervals [95% CI], 1.071–2.172) and proximal advanced CRNs (OR, 2.671; 95% CI, 1.088–6.560). Periodontitis might be associated with proximal CRNs and proximal advanced CRNs.

Assessment of Clinical Outcomes after Peroral Endoscopic Myotomy via Esophageal Distensibility Measurements with the Endoluminal Functional Lumen Imaging Probe

Background/Aims

Endoluminal functional lumen imaging probe (EndoFLIP) is a modality that enables clinicians to measure volume-controlled distension of the esophagus. This study aimed to assess the utility of EndoFLIP in patients who had achalasia treated with peroral endoscopic myotomy (POEM). We hypothesized that improvement in the distensibility index (DI) is correlated with the postoperative clinical outcome of POEM.

Methods

Patients who underwent POEM for achalasia at Cha Bundang Medical Center were included. Physiological measurements of the lower esophageal sphincter (LES) pressure before and after POEM were assessed using EndoFLIP. Patients’ symptoms were recorded using the Eckardt score.

Results

A total of 52 patients with achalasia were included in this study. Patients with a post-POEM DI below 7 (30 or 40 mL) had a significantly higher rate of incomplete response after POEM (p=0.001). Changes in LES pressure or integrated relaxation pressure after POEM were also significantly associated with an incomplete response (p=0.026 and p=0.016, respectively). Multivariate analysis showed that post-POEM DI <7 was the most important predictor of an incomplete response after POEM (p=0.004).

Conclusions

Lower post-POEM DI values were associated with an incomplete post-POEM response. Therefore, post-POEM DI at the esophagogastric junction using EndoFLIP is a useful index for predicting the clinical outcome of POEM in patients with achalasia.

Performance of disposable endoscopic forceps according to the manufacturing techniques

BACKGROUND/AIMS

Recently, to lower the production costs and risk of infection, new disposable biopsy forceps made using simple manufacturing techniques have been introduced. However, the effects of the manufacturing techniques are unclear. The aim of this study was to evaluate which types of biopsy forceps could obtain good-quality specimens according to the manufacturing techniques.

METHODS

By using an in vitro nitrile glove popping model, we compared the popping ability among eight different disposable biopsy forceps (one pair of biopsy forceps with cups made by a cutting method [cutting forceps], four pairs of biopsy forceps with cups made by a pressing method [pressing forceps], and three pairs of biopsy forceps with cups made using a injection molding method [molding forceps]). Using an in vivo swine model, we compared the penetration depth and quality of specimen among the biopsy forceps.

RESULTS

In the in vitro model, the molding forceps provided a significantly higher popping rate than the other forceps (cutting forceps, 25.0%; pressing forceps, 17.5%; and molding forceps, 41.7%; p = 0.006). In the in vivo model, the cutting and pressing forceps did not provide larger specimens, deeper biopsy specimen, and higher specimen adequacy than those obtained using the molding forceps (p = 0.2631, p = 0.5875, and p = 0.2147, respectively). However, the molding forceps showed significantly more common crush artifact than the others (cutting forceps, 0%; pressing forceps, 5.0%; and molding forceps, 43.3%; p = 0.0007).

CONCLUSION

The molding forceps provided lower performance than the cutting and pressing forceps in terms of crush artifact.

Huge Intramural Duodenal Hematoma Complicated with Obstructive Jaundice following Endoscopic Hemostasis

Intramural hematoma of the duodenum is a relatively unusual complication associated with the endoscopic treatment of bleeding peptic ulcers. Intramural hematomas are typically resolved spontaneously with conservative treatment alone. We report a case of an intramural duodenal hematoma following endoscopic hemostasis with epinephrine injection therapy, which was associated with transient obstructive jaundice in a patient undergoing hemodialysis. The patient developed biliary sepsis due to obstruction of the common bile duct secondary to the huge hematoma. He was treated with fluoroscopy-guided drainage catheter insertion, which spontaneously resolved the biliary sepsis through conservative treatment in 6 weeks. Fluoroscopy-guided drainage may impact the treatment of intramural hematomas that involve life-threatening complications.

Feasibility of intraperitoneal placental-derived mesenchymal stem cell injection in stomachs of diabetic mice

BACKGROUND AND AIM

Diabetic gastropathy is associated with loss of interstitial cells of Cajal and autonomic neuropathy. Effective management for diabetic gastropathy is still unavailable. This study was aimed to confirm the pathogenetic changes in diabetic gastropathy and to examine the effect of treatment with placental-derived mesenchymal stem cells (PDMSCs) in stomachs of animal models.

METHODS

Fourteen non-obese diabetic/ShiLtJ mice of 8 weeks were bled until week 30. Diabetes mellitus developed in 10 out of 14 mice, which all survived with insulin. The mice were grouped into three groups: nondiabetic group (n = 4), diabetic sham group (n = 5), and diabetic PDMSC group (n = 5) all of which were treated with intraperitoneal PDMSCs injection at week 30. All mice were killed at week 34, and the stomachs were examined by immunohistochemical stain with c-kit and neuronal nitric oxide synthase antibodies.

RESULTS

The number of c-kit positive cells in stomach decreased significantly in the diabetic sham group compared with that in the nondiabetic group (21.2 ± 6.7 vs 88.0 ± 29.3, P = 0.006) but increased with PDMSC treatment (21.2 ± 6.7 vs 64.0 ± 15.1, P = 0.02). The positive rate of neuronal nitric oxide synthase in neural plexus was also significantly lower in the diabetic sham group than in the nondiabetic group (22.3% ± 18.5% vs 48.0% ± 22.7%, P = 0.003) but increased with PDMSC treatment (22.3% ± 18.5% vs 43.3% ± 20.5%, P = 0.03).

CONCLUSIONS

Interstitial cells of Cajal and neural plexus decreased in stomachs of mice with diabetes mellitus but were significantly repaired with intraperitoneal injection of PDMSC.

Comparison of the Outcomes of Peroral Endoscopic Myotomy for Achalasia According to Manometric Subtype

Background/Aims

We evaluated whether manometric subtype is associated with treatment outcome in patients with achalasia treated by peroral endoscopic myotomy (POEM).

Methods

High-resolution manometry data and Eckardt scores were collected from 83 cases at two tertiary referral centers where POEM is performed. Manometric tracings were classified according to the three Chicago subtypes.

Results

Among the 83 cases, 48 type I, 24 type II, and 11 type III achalasia cases were identified. No difference was found in pre-POEM Eckardt score, basal lower esophageal sphincter (LES) pressure, or integrated relaxation pressure (IRP) among the type I, type II, and type III groups. All three patient groups showed a significant improvement in post-POEM Eckardt score (6.1±2.1 to 1.5±1.5, p=0.001; 6.8±2.2 to 1.2±0.9, p=0.001; 6.6±2.0 to 1.6±1.4, p=0.011), LES pressure (26.1±13.8 to 15.4±6.8, p=0.018; 32.3±19.0 to 19.2±10.4, p=0.003; 36.8±19.2 to 17.5±9.7, p=0.041), and 4s IRP (21.5±11.7 to 12.0±8.7, p=0.007; 24.5±14.8 to 12.0±7.6, p=0.002; 24.0±15.7 to 11.8±7.1, p=0.019) at a median follow-up of 16 months.

Conclusions

POEM resulted in a good clinical outcome for all manometric subtypes.

Suppressed Helicobacter pylori-associated gastric tumorigenesis in Fat-1 transgenic mice producing endogenous ω-3 polyunsaturated fatty acids

Dietary approaches to preventing Helicobacter pylori (H. pylori)-associated gastric carcinogenesis are widely accepted because surrounding break-up mechanisms are mandatory for cancer prevention, however, eradication alone has been proven to be insufficient. Among these dietary interventions, omega-3-polyunsaturated-fatty acids (ω-3 PUFAs) are often the first candidate selected. However, there was no trial of fatty acids in preventing H. pylori-associated carcinogenesis and inconclusive results have been reported, likely based on inconsistent dietary administration. In this study, we developed an H. pylori initiated-, high salt diet promoted-gastric tumorigenesis model and conducted a comparison between wild-type (WT) and Fat-1-transgenic (TG)-mice. Gross and pathological lesions in mouse stomachs were evaluated at 16, 24, 32, and 45 weeks after H. pylori infection, and the underlying molecular changes to explain the cancer preventive effects were investigated. Significant changes in: i) ameliorated gastric inflammations at 16 weeks of H. pylori infection, ii) decreased angiogenic growth factors at 24 weeks, iii) attenuated atrophic gastritis and tumorigenesis at 32 weeks, and iv) decreased gastric cancer at 45 weeks were all noted in Fat-1-TG-mice compared to WT-mice. While an increase in the expression of Cyclooxygenase (COX)-2, and reduced expression of the tumor suppressive 15-PGDH were observed in WT-mice throughout the experimental periods, the expression of Hydroxyprostaglandin dehydrogenase (15-PGDH) was preserved in Fat-1-TG-mice. Using a comparative protein array, attenuated expressions of proteins implicated in proliferation and inflammation were observed in Fat-1-TG-mice compared to WT-mice. Conclusively, long-term administration of ω-3 PUFAs can suppress H. pylori-induced gastric tumorigenesis through a dampening of inflammation and reduced proliferation in accordance with afforded rejuvenation.

A double blind, placebo-controlled, randomized clinical trial that breast milk derived-Lactobacillus gasseri BNR17 mitigated diarrhea-dominant irritable bowel syndrome

The exact pathogenesis of diarrhea-dominant irritable bowel syndrome (IBS) is not known, but the abnormal microbiota of the gastrointestinal tract is considered to be one of the important contributing factors as in other gastrointestinal diseases such as inflammatory bowel disease, antibiotic-associated diarrhea, and colorectal cancer as well as systemic diseases. Though diverse trials of probiotics had been continued in the treatment of diarrhea-IBS, only a few proved by randomized clinical trial. To prove the efficacy of Lactobacillus gasseri BNR17 isolated from breast milk in patients with diarrhea-IBS, prospective, randomized, placebo controlled clinical trial was done including health related-quality of life analysis, colon transit time, and the changes of fecal microbiota. BNR17 significantly improved the symptoms of diarrhea compared to control group. Health related-QOL analysis showed significant improvement of abdominal pain, distension, disturbed daily life, and mean defecation frequency with BNR17. On comparative CTT before and after BNR17, 6 out of 24 subjects showed significant correction of rapid colon transit pattern, while only 2 out of 24 in placebo (p<0.01). Upon fecal microbiota analysis, BNR17 significantly increased B. fecalis, E. rectale, C. aerofaciens, F. prausnitzil and B. steroris. Conclusively, Lactobacillus gasseri BNR17 can be a potential probiotics to ameliorate diarrhea-IBS.

Experimental study on the friction effect of plastic stents for biliary stone fragmentation (with video)

BACKGROUND AND AIM

In patients with irretrievable or intractable bile duct stone, temporary insertion of a plastic stent (PS) followed by further endoscopic retrograde cholangiopancreatography (ERCP) or surgery has been recommended as a 'bridge' therapy. However, the exact mechanism of stone fragmentation has not been discovered. The aim of the present study was to evaluate whether PS shape can facilitate stone fragmentation.

METHODS

Using a new in vitro bile flow phantom model, we compared the friction effect among three different PS groups (straight PS group, double pigtail-shaped PS group, and screw-shaped PS group) and a control group. Each group had 10 silicon tube blocks that separately contained one stone and two PS. The control group had 10 blocks each with only a stone and no PS. We carried out analysis of the friction effect by stone weight and volume changes among the groups, excluding fragmented stones.

RESULTS

After 8 weeks, complete fragmentation was noted in one out of 34 cholesterol stones (2.9%) and in four out of six pigmented stones (66.7%). Fragmentation tended to be more prominent in the screw-shaped PS group than in the straight PS group, double pigtail-shaped group, and control group (volume change: -11.33%, 7.94%, 4.43%, and 2.05%, respectively, P = 0.1390; weight change: -9.30%, 0.71%, -0.10%, and -1.23%, respectively, P = 0.3553).

CONCLUSION

Stone fragmentation may be induced by PS friction effect. Also, screw-shaped plastic stents may improve friction effect. These results may help guide future PS development and clinical decisions.

Bile Flow Phantom Model and Animal Bile Duct Dilation Model for Evaluating Biliary Plastic Stents with Advanced Hydrophilic Coating

Background/Aims

The efforts to improve biliary plastic stents (PSs) for decreasing biofilm formation and overcome short patency time have been continued. The aim of this study is to evaluate the effect of advanced hydrophilic coating for patency and biodurability of PS.

Methods

Using an in vitro bile flow phantom model, we compared patency between prototype PS with hydrophilic coating (PS+HC) and prototype PS without hydrophilic coating (PS−HC). We performed an analysis of the degree of luminal narrowing by microscopic examination. Using an in vivo swine bile duct dilation model made by endoscopic papillary closure and stent insertion, we evaluated biodurability of hydrophilic coating.

Results

In the phantom model, PS+HC showed less biofilm formation and luminal narrowing than PS−HC at 8 weeks (p<0.05). A total of 31 stents were inserted into the dilated bile duct of seven swine models, and 24 stents were successfully retrieved 8 weeks later. There was no statistical difference of stent patency between the polyethylene PS+HC and the polyurethane PS+HC. The biodurability of hydrophilic coating was sustained up to 8 weeks, when assessing the coating layer by scanning electron microscopy examination.

Conclusions

Advanced hydrophilic coating technology may extend the patency of PS compared to uncoated PS.

Anti-fibrogenic effect of PPAR-γ agonists in human intestinal myofibroblasts

Background

Intestinal fibrosis is a serious complication of inflammatory bowel disease, including Crohn’s disease and ulcerative colitis. There is no specific treatment for intestinal fibrosis. Studies have indicated that peroxisome proliferator-activated receptor- γ (PPAR-γ) agonists have anti-fibrogenic properties in organs besides the gut; however, their effects on human intestinal fibrosis are poorly understood. This study investigated the anti-fibrogenic properties and mechanisms of PPAR-γ agonists on human primary intestinal myofibroblasts (HIFs).

Methods

HIFs were isolated from normal colonic tissue of patients undergoing resection due to colorectal cancer. HIFs were treated with TGF-β1 and co-incubated with or without one of two synthetic PPAR-γ agonists, troglitazone or rosiglitazone. mRNA and protein expression of procollagen1A1, fibronectin, and α-smooth muscle actin were determined by semiquantitative reverse transcription-polymerase chain reaction and Western blot. LY294002 (Akt inhibitor) was used to examine whether Akt phosphorylation was a downstream mechanism of TGF-β1 induced expression of procollagen1A1, fibronectin, and α-smooth muscle actin in HIFs. The irreversible PPAR-γ antagonist GW9662 was used to investigate whether the effect of PPAR-γ agonists was PPAR-γ dependent.

Results

Both PPAR-γ agonists reduced the TGF-β1-induced expression of α-smooth muscle actin which was integrated into stress fibers in HIFs, as determined by actin microfilaments fluorescent staining and α-smooth muscle actin-specific immunocytochemistry. PPAR-γ agonists also inhibited TGF-β1-induced mRNA and protein expressions of procollagen1A1, fibronectin, and α-smooth muscle actin. TGF-β1 stimulation increased phosphorylation of downstream signaling molecules Smad2, Akt, and ERK. TGF-β1 induced synthesis of procollagen1A1, fibronectin, and α-smooth muscle actin through a phosphatidylinositol 3-kinase/Akt-dependent mechanism. PPAR-γ agonists down regulated fibrogenesis, as shown by inhibition of Akt and Smad2 phosphorylation. This anti-fibrogenic effect was PPAR-γ independent.

Conclusions

Troglitazone and rosiglitazone suppress TGF-β1-induced synthesis of procollagen1A1, fibronectin, and α-smooth muscle actin in HIFs and may be useful in treating intestinal fibrosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-017-0627-4) contains supplementary material, which is available to authorized users.

Tissue diagnosis of GI subepithelial tumor only through Trucut biopsy under a forward-viewing endoscope: applicability as newer diagnostic modality

BACKGROUND

Trucut biopsy (TCB) has been proposed to overcome the limitations of endoscopic ultrasonography (EUS)-guided fine-needle aspiration for the pathologic diagnosis of upper gastrointestinal (GI) subepithelial tumor (SET); however, it can be difficult to perform because the Trucut biopsy needle is very stiff. Although technical failures have been reported with the use of TCB, recently the forward-viewing echoendoscope showed a high diagnostic accuracy. We hypothesized that TCB under a conventional forward-viewing endoscope can be applied with higher yield of tissue diagnosis.

METHODS

To evaluate the feasibility of TCB under a forward-looking endoscopy without cumbersome EUS guidance, we introduced a 19-gauge TCB needle into the working channel of a conventional upper endoscope in 27 patients with GI SET to make tissue diagnosis. Prospectively collected data were analyzed, including technical success rate, pathologic result, and adverse events.

RESULTS

Twenty-seven patients with GI SET (18 esophageal tumors and nine gastric tumors) underwent TCB under a forward-looking endoscope. All procedures were performed safely without any TCB-related complications. Subsequently, histopathology examination revealed gastrointestinal stromal tumors (GISTs) in three cases and leiomyomas in 21 cases. Histologic assessment was completed in 24 out of 27 patients (88.9 %) because tissue obtained from three patients, whose tumors were located in the stomach, was not sufficient for the pathologic diagnosis.

CONCLUSIONS

TCB using a conventional forward-viewing endoscope without EUS guidance provided an excellent pathologic diagnosis of upper GI SET.

Endoscopic resection of early gastric cancer: current status and new approaches

Endoscopic resection (ER) of early gastric cancer (EGC) has been an optimal treatment for selected patients. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Moreover, a new microscopic imaging for precise endoscopic diagnosis of EGC is introduced. This review covers the current status and new approaches of ER of EGC.

Double-Scope Peroral Endoscopic Myotomy (POEM) for Esophageal Achalasia: The First Trial of a New Double-Scope POEM

With the accumulation of clinical trials demonstrating its efficacy and safety, peroral endoscopic myotomy (POEM) has emerged as a less invasive treatment option for esophageal achalasia compared with laparoscopic Heller myotomy. However, the difficulty in determining the exact extent of myotomy, a critical factor associated with the success and safety of the procedure, remains a limitation. Although the various endoscopic landmarks and ancillary techniques have been applied, none of these has been proven sufficient. As a solution for this limitation, the double-scope POEM technique with a second endoscope to assure the exact length of the submucosal tunnel has been applied since 2014. Before double-scope POEM was introduced, the second endoscope was applied only to confirm the accuracy of the procedure. In the present study, we performed double-scope POEM in the treatment of esophageal achalasia through a novel procedure of simultaneous application of the second endoscope to assist in the conventional POEM procedure.

Novel 3D-printing technique for caps to enable tailored therapeutic endoscopy

BACKGROUND AND AIM

To evaluate the feasibility of a tailored endoscopic cap created using 3D-printing technology that is customized according to esophagogastric lesions of each patient.

METHODS

Tailored endoscopic caps, which were designed and fabricated with a 3D printer, were inserted in 35 patients. The types of cap were side-hole cap made for cap-assisted endoscopic mucosal resection (EMRC), oblique-head cap designed for endoscopic submucosal dissection (ESD), wide-head cap used for Trucut biopsy (TCB), and narrow-tip cap to facilitate peroral endoscopic myotomy (POEM).

RESULTS

EMRC in the esophagus and gastroesophageal junction was carried out using a side-hole cap in seven patients. Median total procedure time for successful removal of lesions was 14 min (range 8-50 min). Gastric ESD was carried out using with an oblique-head cap in 16 patients, for which the median total procedure time was 53 min. TCB in the esophagus was done using a wide-head cap in eight patients. While carrying out POEM for tunneling, a narrow-tip cap was used in four patients with achalasia.

CONCLUSION

Based on the current proof-of-concept study, we anticipate that creating a tailored endoscopic cap is feasible for therapeutic endoscopy.

Optimal Methods for the Management of Iatrogenic Colonoscopic Perforation

Background/Aims:

Colonoscopic perforations have been managed with exploratory laparotomy, and have resulted in some morbidity and mortality. Recently, laparoscopic surgery is commonly performed for this purpose. The aim of this study was to compare the outcomes of several management strategies for iatrogenic colonoscopic perforations.

Methods:

We retrospectively reviewed the medical records of patients who had been treated for colonoscopic perforation between January 2004 and April 2013 at CHA Bundang Medical Center in Korea.

Results:

A total of 41 patients with colonoscopic perforation were enrolled. Twenty patients underwent conservative management with a success rate of 90%. Surgical management was performed in 23 patients including two patients who were converted to surgical management after the failure of the initial conservative management. Among 14 patients who underwent surgery at 8 hours after the perforation, there was no considerable difference in adverse outcomes between the laparotomy group and the laparoscopic surgery group. The medical costs and claim rate were 1.45 and 1.87 times greater in the exploratory laparotomy group, respectively.

Conclusions:

Conservative management of colonoscopic perforation could be an option for patients without overt symptoms of peritonitis or with a small defect size. If surgical management is required, laparoscopic surgery may be considered as the initial procedure even with a delayed diagnosis.

Image Quality Analysis of Various Gastrointestinal Endoscopes: Why Image Quality Is a Prerequisite for Proper Diagnostic and Therapeutic Endoscopy

Arising from human curiosity in terms of the desire to look within the human body, endoscopy has undergone significant advances in modern medicine. Direct visualization of the gastrointestinal (GI) tract by traditional endoscopy was first introduced over 50 years ago, after which fairly rapid advancement from rigid esophagogastric scopes to flexible scopes and high definition videoscopes has occurred. In an effort towards early detection of precancerous lesions in the GI tract, several high-technology imaging scopes have been developed, including narrow band imaging, autofocus imaging, magnified endoscopy, and confocal microendoscopy. However, these modern developments have resulted in fundamental imaging technology being skewed towards red-green-blue and this technology has obscured the advantages of other endoscope techniques. In this review article, we have described the importance of image quality analysis using a survey to consider the diversity of endoscope system selection in order to better achieve diagnostic and therapeutic goals. The ultimate aims can be achieved through the adoption of modern endoscopy systems that obtain high image quality.

Extragastroesophageal Malignancy-Associated Secondary Achalasia: A Rare Association of Pancreatic Cancer Rendering Alarm Manifestation

Secondary achalasia or pseudoachalasia is a rare esophageal motor abnormality, which mimics primary achalasia; it is not easily distinguishable from idiopathic achalasia by manometry, radiological examination, or endoscopy. Although the majority of reported pseudoachalasia cases are associated with neoplasms at or near the esophagogastric (EG) junction, other neoplastic processes or even chronic illnesses such as rheumatoid arthritis can lead to the development of pseudoachalasia, for example, mediastinal masses, gastrointestinal (GI) tumors of the liver and biliary tract, and non-GI malignancies. Therefore, even if a patient presents with the typical findings of achalasia, we should be alert to the possibility of other GI malignancies besides EG tumors. For instance, pancreatic cancer was found in the case reported here; only four such cases have been reported in the literature. A 47-year-old man was admitted to our center with a 3-month history of dysphagia. His endoscopic and esophageal manometric findings were compatible with primary achalasia. However, unresponsiveness to diverse conventional achalasia treatments led us to suspect secondary achalasia. An active search led to a diagnosis of pancreatic mucinous cystadenocarcinoma invading the gastric fundus and EG junction. This rare case of pseudoachalasia caused by pancreatic carcinoma emphasizes the need for suspecting GI malignancies other than EG tumors in patients refractory to conventional achalasia treatment.

Bio-sheet graft therapy for artificial gastric ulcer after endoscopic submucosal dissection: an animal feasibility study

BACKGROUND

Various bio-sheet grafts have been attempted either to accelerate healing of artificial ulcers or to prevent adverse events after endoscopic submucosal dissection (ESD), but neither prospective nor mechanistic studies were available.

OBJECTIVE

To evaluate the substantial effect of a bio-sheet graft on artificial ulcer healing and its feasibility as an endoscopic treatment modality.

DESIGN

Preclinical, in vivo animal experiment and proof-of-concept study.

SETTING

Animal laboratory.

SUBJECTS

Three mini-pigs, Sus scrofa, mean age 14 months.

INTERVENTION

Multiple ulcers sized 2.5 cm in diameter were generated by ESD in 3 mini-pigs and were assigned randomly into the following 3 groups; control group, bio-sheet group, or combination (bio-sheet plus drug) group. Bio-sheet grafts or bio-sheet plus drug combinations were applied on the artificial ulcers immediately after the ESD.

MAIN OUTCOME MEASUREMENTS

Feasibility and efficacy of endoscopic bio-sheet graft therapy for the management of artificial ulcers and the evaluation of healing conditions based on histology changes in the remaining gastric bed tissues harvested from the stomachs.

RESULTS

Thirty-three ESD specimens were obtained. On an image analysis of the ratio of healed area in the remaining gastric bed tissue compared with the matched dissected gastric mucosa, the control group showed the most significant improvement in healing activity among the 3 groups (P < .05), whereas the severity of inflammation in the remaining ulcer tissue was significantly attenuated in bio-sheet and combination groups (P < .05).

LIMITATIONS

Animal model.

CONCLUSION

Although the bio-sheet grafts provided physical protection from gastric acid attack as reflected in the attenuated inflammation on the ulcer beds, unexpected delayed ulcer healing was noted in the bio-sheet graft group because of its physical hindrance of the healing process.

Endoscopic Submucosal Dissection Using a Novel Versatile Knife: An Animal Feasibility Study (with Video)

Background/Aims

In order to reduce the procedure time and the number of accessory changes during endoscopic submucosal dissection (ESD), we developed a novel versatile knife, which has the combined advantages of several conventional knives. The aim of this study was to compare the efficacy, safety, and histological quality of ESD performed using this novel versatile knife and a combination of several conventional knives.

Methods

This was an in vivo animal study comparing two different modalities of ESD in mini-pigs. Completion time of each resection was documented, and the resected specimens were retrieved and evaluated for completeness. To assess the quality control of the procedures and adverse events, detailed histopathological examinations were performed.

Results

A total of 18 specimens were dissected by ESD safely and easily (nine specimens using the new versatile knife; nine specimens by mixing conventional knives). All resections were completed as en bloc resections. There was no significant difference in procedure time between the 2 modalities (456 seconds vs. 355 seconds, p=0.258) and cutting speed (1.983 mm²/sec vs. 1.57 mm²/sec, p=1.000). The rate of adverse events and histological quality did not statistically differ between the modalities.

Conclusions

ESD with a versatile knife appeared to be an easy, safe, and technically efficient method.

Short duration of lamivudine for the prevention of hepatitis B virus transmission in pregnancy: lack of potency and selection of resistance mutations

This study sought to assess the antiviral efficacy of lamivudine (LMV) administered during third trimester to reduce maternal viraemia and to identify the emergence of LMV resistance. A prospective observational analysis was performed on 26 mothers with high viral load (>10⁷ IU/mL). Twenty-one women received LMV (treated group) for an average of 53 days (range 22-88 days), and the remaining five formed the untreated control group. Serum samples from two time points were used to measure HBV DNA levels and antiviral drug resistance. The LMV-treated women achieved a median HBV DNA reduction of 2.6-log10 IU/mL. Although end-of-treatment (EOT) HBV DNA in four (18%) LMV-treated women remained at >10(7) IU/mL (± 0.5 log IU/mL), no mother-to-baby transmission was observed. In contrast, a baby from the untreated mother was HBsAg positive at 9 months postpartum. Four technologies were used for drug resistance testing. Only ultra-deep pyrosequencing (UDPS) was sufficiently sensitive to detect minor viral variants down to <1%. UDPS showed that LMV therapy resulted in increased viral quasispecies diversity and positive selection of HBV variants with reverse transcriptase amino acid substitutions at sites associated with primary LMV resistance (rtM204I/V and rtA181T) in four (19%) women. These viral variants were detected mostly at low frequencies (0.63-5.92%) at EOT, but one LMV-treated mother had an rtA181T variant that increased from 2.2% pretherapy to 25.59% at EOT. This mother was also infected with the vaccine escape variant (sG145R), which was inhibited by LMV treatment. LMV therapy during late pregnancy only reduced maternal viraemia moderately, and drug-resistant viral variants emerged.

Prevalence of occult hepatitis B virus infection in hemodialysis patients

BACKGROUND/AIMS

The prevalence of occult HBV infection depends on the prevalence of HBV infection in the general population. Hemodialysis patients are at increased risk for HBV infection. The aim of this study was to determine the prevalence of occult HBV infection in hemodialysis patients.

METHODS

Total of 98 patients undergoing hemodialysis in CHA Bundang Medical Center (Seongnam, Korea) were included. Liver function tests and analysis of HBsAg, anti-HBs, anti-HBc and anti-HCV were performed. HBV DNA testing was conducted by using two specific quantitative methods.

RESULTS

HBsAg was detected in 4 of 98 patients (4.1%), and they were excluded. Among 94 patients with HBsAg negative and anti-HCV negative, one (1.1%) patient with the TaqMan PCR test and 3 (3.2%) patients with the COBAS Amplicor HBV test were positive for HBV DNA. One patient was positive in both methods. Two patients were positive for both anti-HBs and anti-HBc and one patient was negative for both anti-HBs and anti-HBc.

CONCLUSIONS

The present study showed the prevalence of occult HBV infection in HBsAg negative and anti-HCV negative patients on hemodialysis at our center was 3.2%. Because there is possibility of HBV transmission in HBsAg negative patients on hemodialysis, more attention should be given to prevent HBV transmission.

Polymorphisms of folate metabolism-related genes and survival of patients with colorectal cancer in the Korean population

BACKGROUND

5-Fluorouracil (5-FU) is a cornerstone of chemotherapy for colorectal cancer (CRC), and the major targets of 5-FU are thymidylate synthase (TS), methylenetetrahydrofolate reductase (MTHFR), and reduced folate carrier 1 (RFC1). We hypothesized that polymorphisms in the genes encoding these proteins would be associated with CRC patient survival.

PATIENTS AND METHODS

We genotyped the following polymorphisms in 372 CRC patients: TS enhancer region (TSER), TS 1494del6, MTHFR 677C>T and 1298A>C, and RFC1 -43T>C, 80G>A, and 696C>T. Using Kaplan-Meier curves, log-rank tests, and Cox proportional hazard models, we evaluated associations between these polymorphisms and overall survival (OS).

RESULTS

The combined TS 1494 0bp6bp+6bp6bp genotype was associated with reduced OS compared to the TS 1494 0bp0bp genotype. Among rectal cancer patients, the RFC1 -43CC and 80AA genotypes were associated with favorable OS.

CONCLUSIONS

Our data suggest that TS and RFC1 polymorphisms are associated with CRC prognosis in Korean patients. Further studies are needed to verify these findings.

Clinical outcomes and risk factors of post-polypectomy coagulation syndrome: a multicenter, retrospective, case-control study

BACKGROUND AND STUDY AIMS

Post-polypectomy coagulation syndrome (PPCS) is a well known complication of colonoscopic polypectomy. However, no previous studies have reported on the clinical outcomes or risk factors of PPCS. The aim of the current study was to analyze the clinical outcomes and risk factors of PPCS developing after a colonoscopic polypectomy.

PATIENTS AND METHODS

Data for all patients who underwent colonoscopic polypectomies and required hospitalization in nine university hospitals were analyzed retrospectively. The incidence, clinicopathological characteristics, and clinical outcomes of PPCS cases were examined. Additionally, patients who developed PPCS were compared with controls who were matched by age and sex, in order to assess for possible risk factors.

RESULTS

The rate of PPCS that required hospitalization after colonoscopic polypectomy was 0.7/1000. All patients with PPCS were treated medically without the need for surgical interventions. The median durations of therapeutic fasting, hospitalization, and antibiotic use were 3 days, 5.5 days, and 7 days, respectively. The rates of major PPCS and mortality were 2.9 % and 0 %, respectively. On multivariate analysis, hypertension (OR = 3.023, 95 %CI 1.034 - 8.832), large lesion size (OR = 2.855, 95 %CI 1.027 - 7.937), and non-polypoid configuration (OR = 3.332, 95 %CI 1.029 - 10.791) were found to be independent risk factors related to the development of PPCS.

CONCLUSIONS

In this study, the rates of major PPCS and mortality were only 2.9 % and 0 %, respectively. Hypertension, large lesion size, and non-polypoid configuration of the lesion were independently associated with PPCS. Therefore, patients may be reassured by the excellent prognosis of PPCS, while endoscopists should be especially careful when performing colonoscopic polypectomies in patients with hypertension or large and non-polypoid lesions.