Comparison of Retroflexed and Forward Views for Colorectal Endoscopic Submucosal Dissection

Background: The use of a retroflexed view exposes the entire tumor surface, which is obscured in the forward view, and contributes to complete tumor resection when combined with forward views. However, the efficacy and safety of using the retroflexed view for colorectal endoscopic submucosal dissection (ESD) are poorly understood.Methods: In this study, we assessed the efficacy and safety of the retroflexed view in colorectal ESD. From April 2009 to December 2013, 130 colorectal tumors were examined in 128 patients treated with ESD. A total of 119 patients with a mean tumor size of 27.2 mm were enrolled in the study, and these patients were assigned to undergo colorectal ESD with or without a retroflexed view.Results: The use of retroflexion was successful in 84.2% of patients. There were no perforations in the study and no complications related to the use of retroflexed views. The mean procedure time was 103.6±55.8 min in the retroflexed group, as compared with 108.0±66.5 min in the forward view group. The mean procedure time for resecting tumors >40 mm was significantly shorter in the retroflexed group relative to the forward group. Additionally, the mean dissection speed per unit area was significantly faster in the retroflexed group, as compared with the forward group.Conclusions: Retroflexed views can be used to remove lesions >40 mm and shorten procedure times. Retroflexion may also contribute to an improved en bloc resection rate.     

内镜超声指导下食管黏膜下切除术的疗效研究

目的探讨在内镜超声指导下的食管黏膜下肿瘤切除术的应用。方法 2010年1月至2013年5月79例疑为上消化道黏膜下肿瘤患者进行内镜超声检查,并行内镜下黏膜下肿块切除和病理学检查,对比内镜超声检查与病理学检查结果,分析治疗效果及并发症情况。结果内镜超声检查准确提示了肿瘤所在层次,通过内镜下黏膜下肿瘤切除术切除了所有病变,术后5例发生少量出血,6例因切除黏膜较多造成食管狭窄,经处理后预后可。结论内镜超声检查能够准确判断黏膜下肿瘤,可用于指导黏膜下肿瘤切除术。     

消化内镜黏膜下剥离术治疗早期食管癌的疗效分析

目的分析消化内镜黏膜下剥离术(ESD)治疗早期食管癌的疗效及安全性。方法纳入早期食管癌患者99例,将其中以ESD为治疗方案的52例患者纳入ESD组,同期实施内镜下黏膜切除术(EMR)的47例患者纳入EMR组,分析患者手术情况、术后情况、病灶切除效果、并发症及复发情况。结果与EMR组比较,ESD组手术时间和术后禁食时间较长,最大病灶直径较大,组间比较差异均有统计学意义(P<0.05);2组患者术后抗生素使用时间和住院时间比较,差异无统计学意义(P>0.05)。ESD组病灶整块切除率及病灶完全切除率均高于EMR组,差异有统计学意义(P<0.05)。2组患者并发症发生率比较,差异无统计学意义(P>0.05)。ESD组患者术后12个月复发率低于EMR组,差异有统计学意义(P<0.05)。结论ESD治疗直径较大的早期食管癌具有剥离病灶彻底、复发率较低的优势。     

应用内镜黏膜下剥离术处理食管黏膜病变疗效评价

目的应用内镜黏膜下剥离术(ESD)处理食管早癌及癌前病变,评价其疗效和安全性。方法回顾性分析2008年10月至2009年10月分别于复旦大学附属中山医院和新疆医科大学第六附属医院内镜检查及病理诊断为早期食管癌及癌前病变35例患者,其中男性24例,女性11例;年龄38～78岁,平均年龄60岁。对患者行内镜下治疗,观察术中出血、穿孔及术后食管狭窄的发生情况,统计病灶完整大块切除率与组织学完全切除率,通过随访评价复发或转移情况,对内镜治疗短期效果进行初步评价。结果完成ESD操作28例,7例(20.0%)改为内镜下黏膜切除术(EMR)切除,手术耗时20～125min,平均耗时65 min。颈部气肿1例,术中穿孔2例(5.7%),术中少量出血8例(22.9%),术后延迟性出血1例。组织学治愈26例(74.3%)。除2例手术治疗外,32例完成随访,1例(3.3%)失访。随访4～26个月,中位随访时间10个月。随访中,3例复发,复发率9.4%(3/32),3例发生术后食管狭窄包括1例复发病例。结论 ESD治疗早期食管癌及癌前病变具有较好的疗效和安全性。     

超声内镜精准评估肿瘤起源及组织学特征可提高食管平滑肌瘤的手术疗效

目的 探讨超声内镜评估肿瘤起源及组织学特征能否提高内镜下切除食管平滑肌瘤的手术疗效。 方法 回顾性分析2016年1月～2020年6月因食管黏膜下肿瘤于消化内科治疗并经病理证实为平滑肌瘤患者的临床资料。共58例食管平滑肌瘤患者接受术前超声内镜检查评估后进行内镜下切除。统计患者的肿瘤完整切除率、手术时间、住院时长及并发症发生情况。 结果 术前超声内镜提示,平滑肌瘤起源于黏膜肌层39例,固有肌层19例。瘤体平均直径1.50（0.2～6.5）cm,其中20例行内镜黏膜切除术(EMR),32例行内镜黏膜下挖除术(ESE),6例行黏膜下隧道内镜肿瘤切除术(STER)。总体完整切除率为96.6%。平均手术时间为38.29（15～100）min。术后并发症发生率15.5%（9/58）,均经保守治疗后好转。在39例黏膜肌层起源平滑肌瘤中,20例行EMR,19例行ESE,两组患者的肿瘤大小及并发症发生上差异不显著,但EMR组的手术时间及患者术后住院天数明显更短（P<0.05）。在19例固有肌层起源平滑肌瘤中,13例行ESE,6例行STER,两组患者在肿瘤大小、手术时间、术后住院天数及并发症发生上差异均无显著统计学意义。 结论 术前超声内镜精准评估肿瘤起源及组织学特征可提高食管平滑肌瘤手术疗效。     

Feasibility of endoscopic submucosal dissection for gastric and colorectal lesions: Initial experience from the Gastrocentro – Unicamp

OBJECTIVE:

Endoscopic submucosal dissection is a technique developed in Japan for en bloc resection with a lower rate of recurrence. It is considered technically difficult and performed only in specialized centers. This study sought to report the initial experience from the Gastrocentro – Campinas State University for the treatment of gastric and colorectal lesions by endoscopic submucosal dissection.

MATERIALS AND METHODS:

The guidelines of the Japanese Association of Gastric Cancer were used as evaluative criteria. For colorectal lesions, the recommended standards proposed by Uraoka et al. and Saito et al. were employed. The practicability of the method, the development of complications and histological analysis of the specimens were evaluated.

RESULTS:

Sixteen patients underwent endoscopic submucosal dissection from June 2010 to April 2011; nine patients were treated for gastric lesions, and seven were treated for colorectal lesions. The average diameter of the gastric lesions was 28.6 mm, and the duration of resection was 103 min without complications. All lesions presented lesion-free margins. Of the seven colorectal tumors, four were located in the rectum and three were located in the colon. The average size was 26 mm, and the average procedure time was 163 min. Two complications occurred during the rectal resection procedures: perforation, which was treated with an endoscopic clip, and controlled bleeding. One of the lesions presented a compromised lateral margin without relapse after 90 days. Depth margins were all free of lesions.

CONCLUSION:

Endoscopic submucosal dissection at our institution achieved high success rates, with few complications in preliminary procedures. The procedure also made appropriate lesion staging possible.     

Comparison of the haemostatic properties of conventional monopolar and bipolar transurethral resection of the prostate in patients on oral anticoagulants

Introduction

The aim of study is comparing the haemostatic properties of conventional monopolar resection (TURP) and bipolar transurethral resection in saline (TURIS) of the prostate in patients under chronic oral anticoagulants.

Material and methods

Out of a cohort group of 550 endoscopic resections for bladder outlet obstruction, 176 patients on chronic oral anticoagulant therapy required endoscopic resection either by monopolar TURP or bipolar TURIS technology. Changes in haemoglobin, blood transfusion, and clot retention were compared between both groups.

Results

Mean postoperative change in haemoglobin level was –1.21 ±0.92 mg/dl in the TURP group compared to –1.29 ±0.99 mg/dl in the TURIS group (p = 0.603). The need for blood transfusions and the mean numbers of units transfused did not significantly differ between the 2 groups. Clot retention appeared in 12 patients (15%) in the TURP group compared to 13 patients (13%) in the TURIS group (p = 0.828).

Conclusions

Despite promising experimental results of better haemostasis and deeper coagulation depth, bipolar technology does not permit one to reduce the amount of blood loss when compared to patients treated by conventional monopolar technology in this study group of patients on oral anticoagulation therapy. Patients on oral anticoagulants suffer more incidents of clot retention, which sometimes results in re-hospitalisation.     

Efficacy and Safety of Endoscopic Resection Therapies for Rectal Carcinoid Tumors: A Meta-Analysis

Purpose

Several endoscopic resection therapies have been applied for the treatment of rectal carcinoid tumors. However, there is currently no consensus regarding the optimal strategy. We performed a meta-analysis to compare the efficacy and safety of endoscopic mucosal resection (EMR) or modified EMR (m-EMR) versus endoscopic submucosal dissection (ESD) for the treatment of rectal carcinoid tumors.

Materials and Methods

PubMed, Web of Science, Medline, Embase and CNKI were searched up to the end of January 2014 in order to identify all studies on the effects of EMR (or m-EMR) and ESD on rectal carcinoid tumors.

Results

A total of fourteen studies involving 782 patients were included. The pooled data suggested a significantly higher rate of pathological complete resection among patients treated with ESD or m-EMR than those treated with EMR [odds ratio (OR)=0.42, 95% confidence interval (CI): 0.25-0.71; OR=0.10, 95% CI: 0.03-0.33, respectively], while there was no significant difference between the m-EMR group and ESD group (OR=1.19, 95% CI: 0.49-2.86); The procedure time of ESD was longer than EMR or m-EMR groups [mean differences (MD)=-11.29, 95% CI: -14.19 - -8.38, MD= -10.90, 95% CI: -18.69 - -3.11, respectively], but it was insignificance between the EMR and m-EMR groups. No significant differences were detected among the treatment groups with regard to complications or recurrence.

Conclusion

The results of this meta-analysis suggest that treatment of rectal carcinoid tumors with ESD or m-EMR is superior to EMR, and the efficacy of m-EMR is equivalence to ESD treatment. However, more well-designed studies are needed to confirm these findings.     

Correlation between Soluble Triggering Receptor Expressed on Myeloid Cells-1 and Endoscopic Activity in Intestinal Beh?et's Disease

Purpose

The serum levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) have recently been shown to be correlated highly with disease activity in patients with intestinal Behçet''s disease (BD). However, it remains unclear whether sTREM-1 levels reflect endoscopic activity in intestinal BD. This study aimed to evaluate the correlation of sTREM-1 levels with endoscopic activity in intestinal BD.

Materials and Methods

A total of 84 patients with intestinal BD were enrolled. Endoscopic activity was compared with sTREM-1 levels as well as other laboratory findings, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).

Results

sTREM-1 levels were significantly increased in intestinal BD patients compared with controls (37.98±27.09 pg/mL vs. 16.65±7.76 pg/mL, p=0.002), however, there was no difference between endoscopically quiescent and active diseases (43.53±24.95 pg/mL vs. 42.22±32.68 pg/mL, p=0.819). Moreover, serum sTREM-1 levels did not differ in terms of number, shape, depth, size, margin, or type of ulcer in patients with intestinal BD. However, mean ESR and CRP levels in patients with active disease were significantly higher than those in patients with quiescent disease (p=0.001, p<0.001, respectively). In addition, endoscopic activity scores for intestinal BD were correlated significantly with both CRP levels (γ=0.329) and ESR (γ=0.298), but not with sTREM-1 levels (γ=0.166).

Conclusion

Unlike CRP levels and ESR, serum sTREM-1 levels were not correlated with endoscopic activity in patients with intestinal BD.     

Prognostic significance of intestinal claudins in high-risk synchronous and metachronous multiple gastric epithelial neoplasias after initial endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is useful in en bloc curative resection and enables patients with early gastric carcinoma (GC) to have a better quality of life. But metachronous recurrence of GC at other sites in the stomach has become a major issue after initial ESD. The purpose of the present paper was to examine gastric (claudin-18) and intestinal claudin (claudin-3 and claudin-4) expression in early GC on immunohistochemistry to clarify the association with clinicopathology, mucin phenotypes, microsatellite instability (MSI) status and the incidence of synchronous and metachronous gastric epithelial neoplasias after initial ESD. According to intestinal claudin expression, a total of 73 early GC were divided into two groups: intestinal claudin-positive (I-CLDN(+)) phenotype ( n  = 52; 71%); and intestinal claudin-negative (I-CLDN(–)) phenotype ( n  = 21; 29%). Although no significant association was found with clinicopathology and the MSI status, the I-CLDN(+) early GC correlated with the mucin phenotypes and had a significantly higher incidence of synchronous and metachronous multiple GC and gastric adenomas ( P  = 0.049). These results indicate that early GC demonstrating I-CLDN(+) phenotype have a high risk of synchronous and metachronous secondary gastric epithelial neoplasias.     

Challenges in pathological assessment of endoscopic resections

Endoscopic resections (ERs) are performed for early (T1) cancers mostly of the esophagus, stomach and colorectum, offering a minimally invasive and tissue-preserving alternative to traditional surgical resection. Proper preparation and handling of these specimens is key to allow accurate histological assessment of parameters which will dictate the curative, or non-curative, nature of the procedure. Many histological features have been identified which correlate with risk of recurrence and/or nodal metastases, thereby dictating the need for further management. These include histological subtype of the lesion, grade, depth of invasion, margin status, tumor size, lymphovascular invasion and tumor budding [at least in the colon]. This review article will discuss the ideal specimen preparation and discuss each of these histological parameters in turn, as they pertain to the esophagus, stomach and colorectum, highlighting potential caveats and pitfalls to be aware of when reporting these specimens.     

Gastric lymphangioma

Gastric lymphangioma is a rare benign gastric tumor composed of unilocular or multilocular lymphatic spaces. On gastrofiberscopy a submucosal tumor covered with smooth transparent normal mucosa is revealed in the stomach with or without a stalk. Endoscopic ultrasonography has become an indispensable tool for differentiating these gastric tumors. Treatment of lymphangioma depends on its size, location, and presence of complications. Endoscopic resection is safe and easy and plays an important role in confirming the diagnosis and treatment of the tumors especially of small-sized ones. We report a case of gastric lymphangioma in a 68-yr-old woman who presented with nausea and vague epigastric discomfort for two months. She was diagnosed by gastrofiberscopy with endoscopic ultrasonography and treated successfully with endoscopic resection by strip biopsy method.     

Meta-analysis of Predictive Clinicopathologic Factors for Lymph Node Metastasis in Patients with Early Colorectal Carcinoma

The objective of this study was to conduct a meta-analysis to determine risk factors that may facilitate patient selection for radical resections or additional resections after a polypectomy. Eligible articles were identified by searches of PUBMED, Cochrane Library and Korean Medical Database using the terms (early colorectal carcinoma [ECC], lymph node metastasis [LNM], colectomy, endoscopic resection). Thirteen cohort studies of 7,066 ECC patients who only underwent radical surgery have been analysed. There was a significant risk of LNM when they had submucosal invasion (≥ SM2 or ≥ 1,000 µm) (odds Ratio [OR], 3.00; 95% confidence interval [CI], 1.36-6.62, P = 0.007). Moreover, it has been found that vascular invasion (OR, 2.70; 95% CI, 1.95-3.74; P < 0.001), lymphatic invasion (OR, 6.91; 95% CI, 5.40-8.85; P < 0.001), poorly differentiated carcinomas (OR, 8.27; 95% CI, 4.67-14.66; P < 0.001) and tumor budding (OR, 4.59; 95% CI, 3.44-6.13; P < 0.001) were significantly associated with LNM. Furthermore, another analysis was carried out on eight cohort studies of 310 patients who underwent additional surgeries after an endoscopic resection. The major factors identified in these studies include lymphovascular invasion on polypectomy specimens (OR, 5.47; 95% CI, 2.46-12.17; P < 0.001) and poorly or moderately differentiated carcinomas (OR, 4.07; 95% CI, 1.08-15.33; P = 0.04). For ECC patients with ≥ SM2 or ≥ 1,000 µm submucosal invasion, vascular invasion, lymphatic invasion, poorly differentiated carcinomas or tumor budding, it is deemed that a more extensive resection accompanied by a lymph node dissection is necessary. Even if the lesion is completely removed by an endoscopic resection, an additional surgical resection should be considered in patients with poorly or moderately differentiated carcinomas or lymphovascular invasion.

Graphical Abstract

相似文献   

Endoscopic ultrasonography‐guided fine‐needle aspiration for diagnosing upper gastrointestinal submucosal lesions: A prospective study of 50 cases

The objective was to assess EUS‐FNA for diagnosing intramural upper GI tract lesions. The subjects were 50 patients (21M/29F) with upper GI submucosal lesions who underwent EUS‐FNA at a referral center for GI system over a 12‐month period. All cases were followed for 1 year after initial EUS‐FNA. Cytologic diagnoses were categorized as benign, malignant, suspicious for malignancy, mesenchymal tumor, endocrine tumor, or nondiagnostic. All tumors were assessed for various cytomorphologic features. The accuracy of the initial FNA diagnoses was evaluated for each patient who also underwent subsequent histopathological examination of a core biopsy and/or surgical biopsy/resection material of the same lesion. According to the site of the lesions; while 84% of all esophageal lesions were diagnosed as mesenchymal; 67% of all gastric lesions were mesenchymal. The sole lesion was nonmesenchymal (benign cyst) in duodenum. The sensitivity, specificity, positive and negative predictive values, and accuracy of EUS‐FNA for diagnosing submucosal mesenchymal tumors of the upper GI tract were 82.9, 73.3, 87.9, 64.7, and 80%, respectively. The corresponding values for nonmesenchymal lesions were 100, 85.7, 80, 100, and 90.9%. Our experience confirms that EUS‐FNA is an extremely valuable tool for diagnosing submucosal lesions of the upper GI, and is particularly useful in cases where endoscopic forceps biopsy does not lead to diagnosis. Optimal results can be yielded by a close working relationship between the gastroenterologist and pathologist. Diagn. Cytopathol. 2011. © 2010 Wiley‐Liss, Inc.     

The Efficacy of Endoscopic Palliation of Obstructive Jaundice in Hepatocellular Carcinoma

Purpose

Obstructive jaundice in patients with hepatocellular carcinoma (HCC) is uncommon (0.5-13%). Unlike other causes of obstructive jaundice, the role of endoscopic intervention in obstructive jaundice complicated by HCC has not been clearly defined. The aim of this study was to evaluate the clinical characteristics of obstructive jaundice caused by HCC and predictive factors for successful endoscopic intervention.

Materials and Methods

From 1999 to 2009, 54 patients with HCC who underwent endoscopic intervention to relieve obstructive jaundice were included. We defined endoscopic intervention as a clinical success when the obstructive jaundice was relieved within 4 weeks.

Results

Clinical success was achieved in 23 patients (42.6%). Patients in the clinical success group showed better Child-Pugh liver function (C-P grade A or B/C; 17/6 vs. 8/20), lower total bilirubin levels (8.1±5.3 mg/dL vs. 23.1±10.4 mg/dL) prior to the treatment, and no history of alcohol consumption. The only factor predictive of clinical success by multivariate analysis was low total bilirubin level at the time of endoscopic intervention, regardless of history of alcohol consumption [odds ratio 1.223 (95% confidence interval, 1.071-1.396), p=0.003]. The cut-off value of pre-endoscopic treatment total bilirubin level was 12.8 mg/dL for predicting the clinical prognosis. Median survival after endoscopic intervention in the clinical success group was notably longer than that in the clinical failure group (5.6 months vs. 1.5 months, p≤0.001).

Conclusion

Before endoscopic intervention, liver function, especially total bilirubin level, should be checked to achieve the best clinical outcome. Endoscopic intervention can be helpful to relieve jaundice in well selected patients with HCC.     

How Much Colonic Redundancy Could Be Obtained by Splenic Flexure Mobilization in Laparoscopic Anterior or Low Anterior Resection?

Background and Objectives: Splenic flexure mobilization (SFM) is performed to ensure a tension free anastomosis with an adequate resection margin in laparoscopic anterior resection (AR) or low anterior resection (LAR). This retrospective study was performed to determine the amount of colonic redundancy that can be expected by SFM.Methods: Retrospective review of medical record for a total of 203 patients who underwent SFM during laparoscopic AR or LAR for the treatment of sigmoid colon or rectal cancer was performed.Results: The obtained redundancy of the colon by SFM was 27.81 ± 7.29 cm from the sacral promontory. The redundancy of the colon by SFM with high ligation of the inferior mesenteric vein (IMV) (29.54 ± 7.17 cm from the sacral promontory) was greater than that with low ligation of the IMV (24.94 ± 6.07 cm from the sacral promontory, P < 0.0001). It took about 9.82% of the total operation time to perform SFM. There was no intraoperative complication during SFM.Conclusions: SFM during laparoscopic AR or LAR is a safe and feasible option. Based on the result of this study, one can gain about 27.81 cm redundancy of the colon by SFM.     

Predictive Role of Endoscopic Surveillance after Total Gastrectomy with R0 Resection for Gastric Cancer

BackgroundEndoscopic surveillance after total gastrectomy (TG) for gastric cancer is routinely performed to detect tumor recurrence and postoperative adverse events. However, the reports on the clinical benefits of endoscopic surveillance are ambiguous. We investigated the clinical benefit of endoscopic surveillance after TG for gastric cancer.MethodsWe analyzed 848 patients who underwent TG with R0 resection for gastric cancer between 2011 and 2012 (380 early gastric cancer and 468 advanced gastric cancer) and underwent regular postoperative surveillance with endoscopy and abdominopelvic computed tomography (CT) with contrast.ResultsMedian follow-up periods were 58 months for both endoscopy (range, 3–96) and abdominopelvic CT (range, 1–96). Tumor recurrence occurred in 167 patients (19.7%), of whom seven (4.2%) were locoregional recurrences in the peri-anastomotic area (n = 5) or regional gastric lymph nodes (n = 2). Whereas the peri-anastomotic recurrences were detected by both endoscopy and abdominopelvic CT, regional lymph node recurrences were only detected by abdominopelvic CT. Out of the 23 events of postoperative adverse events, the majority (87%) were detected by radiologic examinations; three events of benign strictures in the anastomotic site were detected only by endoscopy.ConclusionEndoscopic surveillance did not have a significant role in detecting locoregional tumor recurrence and postoperative adverse events after TG with R0 resection for gastric cancer. Routine endoscopic surveillance after TG may be considered optional and performed according to the capacities of each clinical setting.     

Splenosis in gastric fundus mimicking gastrointestinal stromal tumor: a report of two cases and review of the literature

Splenosis refers to heterotopic autotransplantation and implantation of splenic tissue following splenic trauma or surgery. Splenosis in gastric fundus is rare and difficult to diagnose, since splenosis has similar manifestation with gastrointestinal stromal tumor (GIST) under routine endoscopy examination. In this report, we present two quite rare case of splenosis. Both of their pre-operative diagnose under endoscopic ultrasonography was considered as GIST. Finally, one in the abdominal cavity, adhering closely to the gastric fundus, measuring 20 mm × 15 mm, was resected by surgical operation, and one in the gastric fundus, measuring 20 mm × 20 mm, was resected by endoscopic surgery. The precise diagnosis of splenosis was distinct by post-operative histopathologic examination. In addition, we also made a mini review of previously published articles, in order to provide indication to solve future doubts in diagnosing and treating splenosis.     

Endoscopic ultrasound‐guided fine‐needle aspiration biopsy of gastric schwannoma: Cytomorphologic features and diagnostic pitfalls

Schwannoma rarely occurs in the stomach. We present a case of gastric schwannoma, which was initially evaluated by endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) biopsy and confirmed by surgical resection. The patient was a 57‐years‐old woman with history of dyspepsia, who was found to have a large submucosal mass in the stomach. EUS‐FNA showed scant spindle cells with abundant lymphocytes. The spindle cells were immunoreactive with S100, while negative for CD117, desmin, and CD34. The lymphocytes were mixed B‐cells and T‐cells. Immunostaining, flow cytometry, and molecular testing showed no evidence of B‐cell lymphoma. The diagnosis of gastric schwannoma was confirmed by histopathological evaluation of the resected tumor. Gastric schwannoma has unique features of mixed spindle cells and lymphocytes. The tumor should be differentiated from other gastric mesenchymal tumors, and lymphoproliferative disorder is a pitfall.     

Poly(lactic acid-co-glycolic acid)–poly(ethylene glycol)–poly(lactic acid-co-glycolic acid) thermogel as a novel submucosal cushion for endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is a clinical therapy for early stage neoplastic lesions in the gastrointestinal tract. It is, however, faced with a crucial problem: the high occurrence of perforation. The formation of a submucosal fluid cushion (SFC) via a fluid injection is the best way to avoid perforation, and thus an appropriate biomaterial is vital for this minimally invasive endoscopic technique. In this study, we introduced an injectable thermogel as a novel submucosal injection substance in ESD. The hydrogel synthesized by us was composed of poly(lactic acid-co-glycolic acid)–poly(ethylene glycol)–poly(lactic acid-co-glycolic acid) (PLGA–PEG–PLGA) triblock copolymers. The polymer/water system was a low-viscosity fluid at room temperature and thus easily injected, and turned into a non-flowing gel at body temperature after injection. The submucosal injection of the thermogel to create SFCs was performed in both resected porcine stomachs and living minipigs. High mucosal elevation with a clear margin was maintained for a long duration. Accurate en bloc resection was achieved with the assistance of the thermogel. The mean procedure time was strikingly reduced. Meanwhile, no obvious bleeding, perforation and tissue damage were observed. The application of the thermogel not only facilitated the ESD procedure, but also increased the efficacy and safety of ESD. Therefore, the PLGA–PEG–PLGA thermogel provides an excellent submucosal injection system, and has great potential to improve the ESD technique significantly.