Perioperative management and treatment for complications during and after peroral endoscopic myotomy (POEM) for esophageal achalasia (EA) (data from 119 cases)

BACKGROUND

The aim of this study was to investigate the management and treatment for complications during and after peroral endoscopic myotomy (POEM) for patients suffering from esophageal achalasia (EA).

METHODS

The data of 119 cases of EA patients who underwent POEM from October 2010 to July 2011 and the complications that arose during the operation, after the operation, and during follow-up were analyzed.

RESULTS

Complications that occurred during the operation included cutaneous emphysema (22.7 %, 27/119) and pneumothorax (2.5 %, 3/119). Postoperative complications included pneumothorax (25.2 %, 30/119), subcutaneous emphysema (55.5 %, 66/119), mediastinal emphysema (29.4 %, 35/119), delayed hemorrhage (0.8 %, 1/119), pleural effusion (48.7 %, 58/119), minor inflammation or segmental atelectasis of the lungs (49.6 %, 59/119), and gas under diaphragm or aeroperitoneum (39.5 %, 47/119). Complications that occurred during follow-up included one case of difficulty eating caused by the stricture of mucosa and one case of dehiscence at the mouth of the tunnel created during surgery, with food retention. No deaths occurred. All complications were resolved through traditional treatment. No additional surgery was needed.

CONCLUSION

Complications arising during and after POEM should be treated quickly and can be resolved by using traditional treatment. POEM can be expected to become the preferred treatment for EA.

Complete closure of large gastric defects after endoscopic full-thickness resection, using endoloop and metallic clip interrupted suture

BACKGROUND AND STUDY AIM

Successful closure of wall defects is the key procedure following endoscopic full-thickness resection (EFTR). In this report we describe a new method similar to interrupted suture to repair gastric defects by means of endoloops and metallic clips.

PATIENTS AND METHODS

We retrospectively analyzed 20 patients who presented at our institute between March 2011 and February 2012 with gastric submucosal tumors and who consequently underwent EFTR, with the resulting large gastric defects being closed using endoloops and metallic clips. Tumor characteristics, en bloc resection rates, and postoperative complications were evaluated in all the patients.

RESULTS

The median age of the 20 patients was 47 years. The mean maximum size of lesions was 1.47 ± 0.72 cm (range 0.4 - 3 cm). All lesions were diagnosed by endoscopic ultrasound as tumors in the muscularis propria layer. The en bloc resection rate was 100 %. Five patients developed fever and complained of slight abdominal pain in the first day after treatment. No patient had severe complications such as peritonitis or abdominal abscess. In all cases, wounds healed after 1 month. We observed the persistence of the clips for over 3 months in 6 out of 19 cases without any clinical manifestations or large injury to the intestine.

CONCLUSIONS

Our study provides evidence that the use of metallic clips and endoloops is a relatively safe, easy, and feasible method for repairing gastric defects resulting from EFTR.

Risk factors for postoperative stricture after endoscopic submucosal dissection for superficial esophageal carcinoma

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) is accepted as an established treatment modality for superficial esophageal carcinoma (SEC). The aim of this study was to identify risk factors for postoperative stricture after ESD for SEC.

PATIENTS AND METHODS

This was a retrospective study at a single institution. A total of 362 patients with SEC treated by ESD at Zhongshan Hospital, Shanghai, were enrolled between January 2007 and February 2012. Demographic and clinical parameters, including patient-, lesion-, and procedure-related factors, were analyzed for postoperative stricture risk factors.

RESULTS

The postoperative stricture rate was 11.6 % (42/362). The mean and median time from ESD to stricture was 58.5 ± 12.3 days (range 21 - 90 days) and 28 days, respectively. Mild, median, and severe stricture were observed in 16.7 % (7/42), 38.1 % (16 /42), and 45.2 % (19/42) of patients, respectively. Multivariate analysis revealed that circumferential extension of > 3/4 (odds ratio [OR] 44.2, 95 % confidence interval [CI] 4.4 - 443.6) and the depth of invasion above m2 (OR 14.2, 95 %CI 2.7 - 74.2) were independent risk factors for stricture. The degree of stricture was also related to lesion circumferential extension (relational coefficient φ = 0.47; P < 0.05) and histological depth (relational coefficient φ = 0.647; P < 0.05).

CONCLUSIONS

Circumferential extension and histological depth were reliable risk factors for postoperative stricture.

Endoscopic submucosal dissection for treatment of esophageal submucosal tumors originating from the muscularis propria layer

BACKGROUND

The technique of endoscopic submucosal dissection (ESD), which was developed for en bloc resection of large lesions in the stomach, has been widely accepted for the treatment of early gastric cancer. It is being used for muscularis propria tumors of the digestive tract and has produced positive therapeutic effects.

OBJECTIVE

To study the feasibility of ESD for the removal of esophageal muscularis propria tumors and to evaluate the efficacy and safety of ESD for this treatment.

DESIGN

Single-center, retrospective study.

SETTING

University hospital.

PATIENTS

Thirty esophageal muscularis propria tumors from 28 patients were treated with ESD between December 2008 and December 2010. We defined esophageal muscularis propria tumors as esophageal submucosal tumors originating from the muscularis propria layer.

INTERVENTION

ESD.

MAIN OUTCOME MEASUREMENTS

Tumor characteristics, complications, en bloc resection rate, and local recurrence rate were evaluated.

RESULTS

Among the 28 patients, 11 were women (39.3%). The median age was 49.32 years (range 22-62 years). Mean (± SD) tumor size was 1.25 ± 0.70 cm (range 0.5-3.0 cm). Except for 2 failed cases (one changed to surgery and the other changed to nylon ligation), 26 cases with 28 tumors (2 cases had 2 tumors) originating from the muscularis propria of the esophagus were successfully resected by ESD. The en bloc resection rate was 93.3% (28/30). The median ESD procedure time was 73.5 minutes (range 30-120 minutes). Perforation occurred in 2 cases during dissection of the lesion, which was closed with metal endoclips. Pneumothorax occurred after the treatment in both cases. Closed thoracic drainages were initiated, and the patients recovered quickly without surgery. Pathological examination confirmed 27 leiomyomas and 1 GI stromal tumor. The curative resection rate was 100% (28/28). There was no recurrence during a 3 to 27-month follow-up period.

LIMITATIONS

The limitation of the study was its retrospective design.

CONCLUSION

ESD offers the promise of localized treatment of esophageal muscularis propria tumors with relatively few complications and low mortality. It makes the resection of whole lesions possible and provides precise histologic information.

NLRP7 deubiquitination by USP10 promotes tumor progression and tumor-associated macrophage polarization in colorectal cancer

BACKGROUND

NOD-like receptors affect multiple stages of cancer progression in many malignancies. NACHT, LRR, and PYD domain-containing protein 7 (NLRP7) is a member of the NOD-like receptor family, although its role in tumorigenesis remains unclear. By analyzing clinical samples, we found that NLRP7 protein levels were upregulated in colorectal cancer (CRC). We proposed the hypothesis that a high level of NLRP7 in CRC may promote tumor progression. Here, we further investigated the role of NLRP7 in CRC and the underlying mechanism.

METHODS

NLRP7 expression in human CRC and adjacent non-tumorous tissues was examined by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry. The effect of NLRP7 in CRC progression was investigated in vitro and in vivo. Proteins interacting with NLRP7 were identified by immunoprecipitation and mass spectrometry analysis while immunofluorescence staining revealed the cellular location of the proteins. Cellular ubiquitination and protein stability assays were applied to demonstrate the ubiquitination effect on NLRP7. Cloning and mutagenesis were used to identify a lysine acceptor site that mediates NLRP7 ubiquitination. Cytokines/chemokines affected by NLRP7 were identified by RNA sequencing, qRT-PCR, and enzyme-linked immunosorbent assay. Macrophage phenotypes were determined using qRT-PCR, flow cytometry, and immunohistochemistry.

RESULTS

NLRP7 protein levels, but not mRNA levels, were upregulated in CRC, and increased NLRP7 protein expression was associated with poor survival. NLRP7 promoted tumor cell proliferation and metastasis in vivo and in vitro and interacted with ubiquitin-specific protease 10, which catalyzed its deubiquitination in CRC cells. NLRP7 stability and protein levels in CRC cells were modulated by ubiquitination and deubiquitination, and NLRP7 was involved in the ubiquitin-specific protease 10 promotion of tumor progression and metastasis in CRC. K379 was an important lysine acceptor site that mediates NLRP7 ubiquitination in CRC cells. In CRC, NLRP7 promoted the polarization of pro-tumor M2-like macrophages by inducing the secretion of C-C motif chemokine ligand 2. Furthermore, NLRP7 promoted NF-κB nuclear translocation and activation of C-C motif chemokine ligand 2 transcription.

CONCLUSIONS

We showed that NLRP7 promotes CRC progression and revealed an as-yet-unidentified mechanism by which NLRP7 induces the polarization of pro-tumor M2-like macrophages. These results suggest that NLRP7 could serve as a biomarker and novel therapeutic target for the treatment of CRC.

MicroRNA-31 contributes to colorectal cancer development by targeting factor inhibiting HIF-1α (FIH-1)

The molecular mechanisms underlying colorectal cancer (CRC) tumorigenesis remain incompletely understood, partially contributing to the mortality of CRC. Advances in identification of novel mechanisms are therefore in an urgent need to fill the gap of our knowledge in CRC development. Here, we performed both in vitro and in vivo experiments along with in silico analysis to identify a new regulatory circuit that stimulated CRC tumorigenesis. In this report, we, for the first time, analyzed the correlation of FIH-1 level with clinicopathological features of CRC. The finding that FIH-1 was not only significantly decreased in tumor tissue as compared with the adjacent normal tissue but also was significantly correlated with tumor T stage status, indicated the role of FIH-1 as a tumor suppressor in CRC development. Moreover, we found the expression of miR-31, a short non-coding RNA which played a critical role in CRC development, was negatively correlated with FIH-1 expression in CRC samples and cell lines. Together with the result from luciferase report assay, it was demonstrated that miR-31 could directly regulate FIH-1 expression in CRC. This miR-31/FIH-1 nexus was further shown to control cell proliferation, migration and invasion in vitro and to control tumor growth in vivo. Additionally, correlation of the miR-31 expression with clinicopathologic features in CRC samples was examined in support of the driving role of newly identified miR-31/FIH-1 nexus in CRC tumorigenesis. These findings highlight the critical role of miR-31/FIH-1 nexus in CRC and reveal the contribution of miR-31 to CRC development by targeting FIH-1.

Efficacy and Safety of Endoscopic Submucosal Dissection for Colorectal Carcinoids

BACKGROUND & AIMS

Although endoscopic submucosal dissection (ESD) of colorectal carcinoids is increasing, little is known about long-term outcomes of patients. We investigated the efficacy and safety of ESD of colorectal carcinoids and evaluated long-term outcomes, including local recurrence and metastasis.

METHODS

We performed a retrospective analysis of data collected from 239 consecutive patients with colorectal carcinoids <20 mm who underwent endoscopic ultrasonography (to evaluate the size of tumor and the depth of invasion), followed by ESD from January 2007 through October 2012 at the Zhongshan Hospital of Fudan University. Histology and patient data were collected during a median follow-up period of 52 months (range, 25-94 months) to determine tumor stage and type, completeness of resection, complications, tumor recurrence, and distant metastasis.

RESULTS

En bloc resection was achieved for all of the 239 treated lesions; tumor tissues were completely resected for 216 of the lesions (90.38%). Eight patients had ESD-related complications (3.35%). As more ESDs were performed by endoscopists, the rate of complete tumor resection increased, and the rate of complications decreased. ESD of carcinoids in colon increased the risk of non-R0 resection and the rate of complications. During the follow-up period, all patients remained free from local recurrence. However, distant metastases were detected in 6 patients (2.51%); lymphovascular invasion was a risk factor for metastasis.

CONCLUSIONS

ESD is effective for the resection of rectal carcinoids <20 mm and causes complications in less than 4% of patients. ESD for colonic carcinoids is feasible but associated with a higher non-R0 resection rate and a trend toward higher complications risk. Tumor features and stage determine risk for distant metastasis, so long-term follow-up is essential.

Factor inhibiting HIF1α (FIH-1) functions as a tumor suppressor in human colorectal cancer by repressing HIF1α pathway

Colorectal cancer (CRC) is one of the most common cancers worldwide. The molecular mechanisms underlying CRC development involve a multistep process with the accumulation of both genetic and epigenetic changes. To deeply understand CRC tumorigenesis and progression, advances in identification of novel mechanisms and key factors are therefore in an urgent need. Here, we examined the correlation of factor inhibiting HIF-1α (FIH-1) expression with clinicopathological features of CRC. The finding that FIH-1 was not only significantly decreased in tumor tissue but also was significantly correlated with tumor invading depth, lymph node involvement, and metastasis suggested the role of FIH-1 as a tumor suppressor in CRC development. To further support the above hypothesis, we performed both in vitro and in vivo experiments to identify the role of FIH-1 in CRC development. FIH-1 was found to inhibit CRC cell proliferation, migration, invasion, and colony formation in vitro. FIH-1 was also shown to repress LOVO xenograft tumor growth in vivo. To decipher the mechanism, we examined the expression level of HIF-1α and its target genes. We found that FIH-1 was able to inhibit HIF1α mediated transcription of GLUT1 and VEGF in CRC cells. The above observation points to the possibility that loss or decreased expression of FIH-1 gene may lead to a constitutive activation of HIF1α and an alteration of HIF-1 targets such as GLUT-1 and VEGF. These findings highlight the critical role of FIH-1 in CRC and indicate FIH-1 functions as a tumor suppressor in human CRC by repressing HIF1α pathway.

Efficacy and safety of endoscopic resection for small submucosal tumors originating from the muscularis propria layer in the gastric fundus

BACKGROUND

Gastric small submucosal tumors (SMTs) are becoming increasingly common. However, the fundus of stomach is regarded as a difficult area for endoscopic resection (ER). In this study, we investigated the efficacy, safety, and long-term outcomes of ER for small SMTs of the gastric fundus in a large series of patients, research that was previously lacking.

METHODS

537 consecutive patients with SMTs no more than 20 mm in diameter, occurring in the gastric fundus and originating from the muscularis propria layer, which were treated with endoscopic submucosal excavation or endoscopic full-thickness resection (EFTR) were included in this retrospective study at Zhongshan Hospital of Fudan University from January 2013 to September 2016. Clinicopathological, endoscopic, and follow-up data were collected and analyzed.

RESULTS

En bloc resection was achieved in 100% of patients, and complete resection was achieved for 530 (98.7%) lesions. Although the total rate of complications was 9.3%, few serious adverse events occurred in only three (0.6%) patients, including major pneumoperitoneum, major hydrothorax, and bleeding. Unlike lager tumor sizes and longer procedure times, endoscopist experience had a positive impact on decreasing the likelihood of complications. Based on statistical analysis, tumors with greater size near the cardia, which were treated by EFTR, were the significant contributors to longer operative times. A median follow-up of 32 months was available, and all patients were free from local recurrence or distant metastasis during the study period.

CONCLUSIONS

Although the gastric fundus presents technical difficulties, ER is effective for the resection of small gastric SMTs with a high complete resection rate and rare serious adverse events.

Endoscopic management of impacted esophageal foreign bodies

There are many reports on the endoscopic management of ingested foreign bodies in the upper gastrointestinal tract, however, little is known about the management of a specific subset of esophageal foreign bodies - impacted esophageal foreign bodies (IEFBs), especially perforating esophageal foreign bodies (PEFBs). The aim of this retrospective study on 78 cases was to report experience and outcome in the endoscopic management of the IEFBs in Chinese patients. From January 2006 to July 2011, a total of 750 patients with suspected upper gastrointestinal foreign bodies were admitted to the endoscopy center. Among these 750 patients, 78 cases that met the defined criteria of IEFBs were retrospectively enrolled in the present study, including 12 cases (12/78, 15.4%) with PEFBs. The major types of IEFBs were poultry bones (35.9%) and fish bones (17.9%). Most of the IEFBs (80.8%) were located in the upper esophagus, as were two thirds (66.7%) of the PEFBs. Foreign-body retrieval forceps were the most frequently used accessory devices. Extraction of IEFBs failed in eight patients (10.3%) during the endoscopic procedure. The difficult points in endoscopic management were PEFBs, IEFBs with sharp points, and those with impaction for more than 24 hours. IEFBs should be treated as early as possible, and their endoscopic management is safe and effective. Endoscopic management is the first choice for PEFBs when the duration of impaction is less than 24 hours and there are no abscesses outside of the esophageal tract as determined by a computed tomography scan.

Endoscopic submucosal dissection for early esophageal cancer in elderly patients with relative indications for endoscopic treatment

BACKGROUND

According to the Japanese Esophageal Society (JES) guidelines, early esophageal squamous cell carcinoma (SCC) involving the muscularis mucosae (M3) or upper submucosal (SM1) layers are relative indications for endoscopic submucosal dissection (ESD). Additional esophagectomy or chemoradiotherapy is recommended for patients with relative indications after evaluation. However, elderly patients (≥ 60 years) with relative indications in China often refuse additional treatment because of the debilitating side effects. The aim of this study was to evaluate the long-term outcomes of elderly patients with relative indications who did not undergo additional treatment after ESD.

METHODS

Data from elderly patients with relative indications who underwent ESD for early esophageal SCC between January 2008 and December 2013 were reviewed retrospectively. Stricture and recurrence, and 5-year progression-free survival (PFS) and overall survival rates were compared with patients with absolute indications for ESD.

RESULTS

158 elderly patients were included and analyzed (89 in the absolute indications group and 69 in the relative indications group). The baseline characteristics were balanced between the two groups. During 56 months (range 1 - 108) of follow-up, the postoperative stricture rates were similar in the absolute and relative indications groups (21.3 % vs. 31.9 %; P  = 0.13). The hazard ratio (HR) for PFS in the absolute vs. the relative indications groups was 1.025 (95 % confidence interval [CI] 0.36 - 2.95; P = 0.96). The 5-year PFS rates were 90.5 % (95 %CI 83.44 - 97.56) and 90.8 % (95 %CI 83.74 - 97.86) for the absolute and relative indications groups, respectively. The HR for overall survival in the absolute vs. the relative indications groups was 0.564 (95 %CI 0.13 - 2.52; P = 0.45). The 5-year overall survival rates were 96.6 % (95 %CI 92.88 - 100) and 95.6 % (95 %CI 90.70 - 100) for the absolute and relative indications groups, respectively.

CONCLUSIONS

Based on this study, regular follow-up without additional treatment may be considered as another choice for elderly patients with early esophageal SCC and relative indications after ESD.

Prediction of technically difficult endoscopic submucosal dissection for large superficial colorectal tumors: a novel clinical score model

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a promising technique for removing superficial GI tumors, but ESD is technically difficult. The aim of this study was to establish a clinical score model for grading technically difficult colorectal ESD.

METHODS

Data on patients, lesions, and outcomes of colorectal ESD at 2 centers were analyzed. The objective parameter of successful ESD within 60 minutes was set as an endpoint to evaluate the difficulty. Independent predictors of difficulty in the derivation cohort were identified by multiple logistic regression analysis and used to develop a clinical score. We validated the score model in the validation cohort.

RESULTS

The clinical score comprised tumor size of 30 to 50 mm (1 point) or ≥50 mm (2 points), at least two-thirds circumference of the lesion (2 points), location in the cecum (1 point), flexure (2 points) or dentate line (1 point), and laterally spreading tumor nongranular lesions (1 point). Areas under the receiver operator characteristic curves for the score model were comparable (derivation [.70] vs internal validation [.69] vs external validation [.69]). The probability of successful ESD within 60 minutes in easy (score = 0), intermediate (score = 1), difficult (score = 2-3), and very difficult (score ≥4) categories were 75.0%, 51.3%, 35.6%, and 3.4% in the derivation cohort; 73.3%, 47.9%, 31.8%, and 16.7% in the internal validation cohort; and 79.5%, 66.7%, 43.3%, and 20.0% in the external validation cohort, respectively.

CONCLUSIONS

This clinical score model accurately predicts the probability of successful ESD within 60 minutes and can be applied to grade the technical difficulty before the procedure.

Silencing of RhoA and RhoC expression by RNA interference suppresses human colorectal carcinoma growth in vivo

BACKGROUND

RhoA and RhoC have been proved to be over-expressed in many solid cancers, including colorectal cancer. The reduction of RhoA and RhoC expression by RNA interference (RNAi) resulted growth inhibition of cancer cells. The present study was to evaluate the effect of silencing of RhoA and RhoC expression by RNAi on growth of human colorectal carcinoma (CRC) in tumor-bearing nude mice in vivo.

METHODS

To establish HCT116 cell transplantable model, the nude mice were subcutaneously inoculated with 1.0 × 10(7) HCT116 cells and kept growing till the tumor xenografts reached 5-7 mm in diameter. Then the mice were randomly assigned to three groups(seven mice in each group): (1) normal saline(NS) group, (2)replication-defective recombinant adenovirus carrying the negative control shRNA (Ad-HK) group and (3)replication-defective recombinant adenovirus carrying the 4-tandem linked RhoA and RhoC shRNAs (Ad-RhoA-RhoC) group. Ad-HK (4 × 10(8) pfu, 30 ul/mouse), Ad-RhoA-RhoC (4 × 10(8) pfu, 30 ul/mouse) or PBS (30 ul/mouse) was injected intratumorally four times once every other day. The weight and volumes of tumor xenografts were recorded. The levels of RhoA and RhoC mRNA transcripts and proteins in tumor xenografts were detected by reverse quantitative transcription polymerase chain reaction (QRT-PCR) and immunohistochemical staining respectively. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to detect the death of cells.

RESULTS

The xenografts in mice could be seen at 5th day from the implantation of HCT116 cells and all had reached 5-7 mm in size at 9th day. After injection intratumorally, the growth speed of tumor xenografts in Ad-RhoA-RhoC group was significantly delayed compared with those in NS and Ad-HK group(P < 0.05). The results of QRT-PCR showed that mRNA levels of RhoA and RhoC reduced more in Ad-RhoA-RhoC group than those in NS and Ad-HK group. The relative RhoA and RhoC mRNA transcripts were decreased to 48% and 43% respectively (P < 0.05). Immunohistochemical analyses of tumor xenograft sections also revealed the decreased RhoA and RhoC expression in Ad-RhoA-RhoC group. TUNEL assay also showed higher death of tumor xenograft tissue cells in Ad-RhoA-RhoC group.

CONCLUSION

Recombinant adenovirus mediated RhoA and RhoC shRNA in tandem linked expression may inhibit the growth of human colorectal tumor xenografts in vivo. These results indicate that RhoA and RhoC might be potential targets for gene therapy in colorectal cancer.

Angiopoietin-like 4 enhances metastasis and inhibits apoptosis via inducing bone morphogenetic protein 7 in colorectal cancer cells

Angiopoietin-like 4 (ANGPTL4), a secretory glycoprotein, plays an important role in cancer metastasis. In the present study, we aim to investigate the roles and mechanisms of ANGPTL4 in the regulation of colorectal cancer metastasis. We found that expression level of ANGPTL4 was increased in colorectal cancer tissues, compared with that in normal tissues. Moreover, liver metastasis was significantly associated with higher expression of ANGPTL4. In vitro studies further showed that overexpression of ANGPTL4 enhanced cell migration, invasion and inhibited apoptosis. At the molecular level, ANGPTL4 overexpression resulted in an up-regulation of bone morphogenetic protein 7 (BMP7). Indeed, knockdown of BMP7 by small interfering RNA (siRNA) oligos reversed the roles of ANGPTL4 overexpression in HCT116 cells. Finally, in vivo studies further confirmed the metastatic roles of ANGPTL4 by inducing BMP7. Therefore, our study demonstrated that ANGPTL4 might promote metastasis and might inhibit apoptosis of colorectal cancer cells by up-regulation of BMP7.

The efficacy of dental floss and a hemoclip as a traction method for the endoscopic full-thickness resection of submucosal tumors in the gastric fundus

BACKGROUND

Endoscopic full-thickness resection (EFTR) provides a significant advancement to the treatment of gastrointestinal submucosal tumors (SMTs). However, technological challenges, particularly in the gastric fundus, hinder its wider application. Here, we investigated the efficacy of a simple traction method that used dental floss and a hemoclip (DFC) to facilitate EFTR.

METHODS

Between July 2014 and December 2016, we retrospectively reviewed data from all patients with SMTs in the gastric fundus originating from the muscularis propria layer that were treated by EFTR at Zhongshan Hospital of Fudan University. Baseline characteristics and clinical outcomes, including procedure time and complications rate, were compared between groups of patients receiving DFC-EFTR and conventional EFTR.

RESULTS

A total of 192 patients were included in our analysis (64 in the DFC-EFTR group and 128 in the conventional EFTR group). Baseline characteristics for the two groups were similar. The mean time for DFC-EFTR and conventional EFTR was 44.2 ± 24.4 and 54.2 ± 33.2 min, respectively (P = 0.034). Although no serious adverse events presented in any of our cases, post-EFTR electrocoagulation syndrome (PEECS), as a minor complication, was less frequent in the DFC-EFTR group (3.1% vs. 12.5%, P = 0.036). Univariate and multivariate analysis identified that DFC, when used in EFTR, played a significant role in reducing procedure time and the rate of PEECS. The mean procedure time was significantly shorter in the DFC-EFTR group for lesions over 1.0 cm (P = 0.005), when the lesions were located in the greater curvature of the gastric fundus (P = 0.025) or when the lesions presented with intraluminal growth (P = 0.032). Moreover, when EFTR was carried out by experts, the mean procedure time was 20.4% shorter in the DFC-EFTR group (P = 0.038).

CONCLUSIONS

This study indicated that DFC-EFTR for SMTs in the gastric fundus resulted in a shorter procedure time and reduced the risk of PEECS, a minor complication.

Endoscopic resection for the treatment of duodenal Brunner's adenomas

OBJECTIVES

Brunner's adenoma is a rare benign tumor of the duodenum. The traditional management option was close follow-up and surgical tumor resection. With the development of endoscopy devices and techniques, endoscopic resection is considered an alternative treatment option. However, whether small lesions require treatment has been controversial. We planned to study the feasibility, efficacy, and safety of endoscopic resection for the treatment of Brunner's adenomas.

SUBJECTS AND METHODS

In total, 30 Brunner's adenomas from 29 patients were treated with endoscopic resection between August 2007 and June 2011 in our hospital. Endoscopic ultrasonography (EUS) was performed preoperatively to evaluate tumor origin and size. Tumor characteristics, complications, en bloc resection rate, and local recurrence rates were evaluated.

RESULTS

Of the 29 patients, 13 (44.8%) were men. The median age was 55 years (range, 29-72 years). The mean maximal dimension of the lesions was 1.7±0.1 cm (range, 0.6-7 cm). Overall, 9 lesions were treated with snare resection, 12 lesions were treated with conventional endoscopic mucosal resection (EMR), and 9 lesions were treated with endoscopic submucosal dissection (ESD). Only 1 case of delayed bleeding occurred on Day 2 after EMR. The en bloc resection rate was 100% (30/30). One lesion resected by EMR exhibited indeterminate tumor margins. The overall curative resection rate was 96.7% (29/30). During the follow-up period (median time, 13 months; range, 2-39 months), 1 patient, whose tumor exhibited indeterminate margins, showed recurrence 1 year after EMR; ESD was recommended. No recurrence was observed during the subsequent follow-up period.

CONCLUSIONS

Our study provides evidence of the efficacy of endoscopic resection for the localized treatment of duodenal Brunner's gland adenomas with relatively few complications and a low mortality rate.

Risk factors for delayed bleeding after endoscopic submucosal dissection of colorectal tumors

AIM

To investigate the risk factors for delayed bleeding following endoscopic submucosal dissection (ESD) for colorectal neoplasms.

METHODS

We retrospectively reviewed the medical records of 991 consecutive patients who underwent ESD for colorectal neoplasms at our hospital from January 2007 to November 2016. Delayed post-ESD bleeding was defined as bleeding within 6 h to 30 days after ESD that resulted in either of the three situations: overt hematochezia, bleeding spots confirmed by repeat colonoscopy, or the requirement of a blood transfusion. Delayed bleeding was furtherly separated into early and late delayed bleeding by the end of post-ESD day 2. We analyzed the relationship between delayed bleeding and candidate factors including patient-, lesion-, and treatment-related details.

RESULTS

Delayed post-ESD bleeding was found in 47 patients (4.7%), of which 18 cases were late delayed bleeding. Among all patients, 14 patients required a second colonoscopy, and 2 other patients were transferred to surgery. Univariate analysis revealed that patients with hypertension (p = 0.017) and using hot biopsy forceps for wound management (p = 0.028) were significantly associated with late delayed bleeding. Both risk factors remained significant after multivariate analysis: hypertension (OR 2.829, 95% CI 1.101-7.265, p = 0.031), hot biopsy forceps (OR 2.873, 95% CI 1.013-8.147, p = 0.047). Using hot biopsy forceps was also the significant risk factor for late delayed bleeding compared with early delayed bleeding.

CONCLUSION

Patient with hypertension and using hot biopsy forceps for wound management during procedure call for attention on high risk of delayed post-ESD bleeding. Therefore, additional perioperative treatment is recommended in patients with these risk factors.

Endoscopic resection of colorectal granular cell tumors

AIM

To determine the feasibility and effectiveness of endoscopic resection for the treatment of colorectal granular cell tumors (GCTs).

METHODS

This was a retrospective study performed at a single institution. From January 2008 to April 2015, we examined a total of 11 lesions in 11 patients who were treated by an endoscopic procedure for colorectal GCTs in the Endoscopy Center, Zhongshan Hospital of Fudan University, Shanghai, China. Either endoscopic mucosal resection or endoscopic submucosal dissection (ESD) was performed by three surgeons with expertise in endoscopic treatment. The pre- and post-operative condition and follow-up of these patients were evaluated by colonoscopy and endoscopic ultrasonography (EUS).

RESULTS

Of these 11 lesions, 2 were located in the cecum, 3 were in the ileocecal junction, 5 were in the ascending colon, and 1 was in the rectum. The median maximum diameter of the tumors was 0.81 cm (range 0.4-1.2 cm). The en bloc rate was 100%, and the complete resection rate was 90.9% (10/11). Post-operative pathology in one patient showed a tumor at the cauterization margin. However, during ESD, this lesion was removed en bloc, and no tumor tissue was seen in the wound. No perforations or delayed perforations were observed and emergency surgery was not required for complications. All patients were followed up to May 2015, and none had recurrence, metastasis, or complaints of discomfort.

CONCLUSION

Endoscopic treatment performed by endoscopists with sufficient experience appears to be feasible and effective for colorectal GCTs.

The laparoscopic-endoscopic cooperative surgery for the colonic calcifying fibrous tumor: one case report

Abstract The calcifying fibrous tumor (CFT) is classified as a benign fibrous lesion, and it is a rare pathologic entity. Local excision is the preferred therapeutic approach in treating CFTs. We present the first reported case in the literature of a CFT found in the colon, and this is the first time the way we did the laparoscopic-endoscopic cooperative surgery has been introduced.

A SAM-I riboswitch with the ability to sense and respond to uncharged initiator tRNA

All known riboswitches use their aptamer to senese one metabolite signal and their expression platform to regulate gene expression. Here, we characterize a SAM-I riboswitch (SAM-IXcc) from the Xanthomonas campestris that regulates methionine synthesis via the met operon. In vitro and in vivo experiments show that SAM-IXcc controls the met operon primarily at the translational level in response to cellular S-adenosylmethionine (SAM) levels. Biochemical and genetic data demonstrate that SAM-IXcc expression platform not only can repress gene expression in response to SAM binding to SAM-IXcc aptamer but also can sense and bind uncharged initiator Met tRNA, resulting in the sequestering of the anti-Shine-Dalgarno (SD) sequence and freeing the SD for translation initiation. These findings identify a SAM-I riboswitch with a dual functioning expression platform that regulates methionine synthesis through a previously unrecognized mechanism and discover a natural tRNA-sensing RNA element. This SAM-I riboswitch appears to be highly conserved in Xanthomonas species.

Self-expandable metallic stenting as a bridge to elective surgery versus emergency surgery for acute malignant right-sided colorectal obstruction

BACKGROUND

The use of a self-expandable metallic stent (SEMS) as a bridge to surgery has increased for patients with obstructing colorectal cancer. However, relatively few reports have compared SEMS as a bridge to elective surgery for acute malignant obstruction of the right-sided colon (MORC) vs. emergency surgery (ES). This study aimed to evaluate the benefits of elective surgery after SEMS placement vs. ES for patients (including stage IV cases) with acute MORC.

METHODS

Patients with acute MORC who underwent radical resection for a primary tumour from July 2008 to November 2016 at Zhongshan Hospital of Fudan University were retrospectively enrolled. Postoperative short-term outcomes, progression-free survival (PFS), and overall survival (OS) were compared between the SEMS and ES groups.

RESULTS

In total, 107 patients with acute MORC (35 in the SEMS group and 72 in the ES group) were included for analysis. The Intensive Care Unit admission rate was lower (11.4% vs. 34.7%, P = 0.011), the incidence of complications was reduced (11.4% vs. 29.2%, P = 0.042), and the postoperative length of hospitalisation was significantly shorter (8.23 ± 6.50 vs. 11.18 ± 6.71 days, P = 0.033) for the SEMS group. Survival curves showed no significant difference in PFS (P = 0.506) or OS (P = 0.989) between groups. Also, there was no significant difference in PFS and OS rates between patients with stage II and III colon cancer. After colectomy for synchronous liver metastases among stage IV patients, the hepatectomy rates for the SEMS and ES groups were 85.7% and 14.3%, respectively (P = 0.029). The hazard ratio for colectomy alone vs. combined resection was 3.258 (95% CI 0.858-12.370; P = 0.041).

CONCLUSION

Stent placement offers significant advantages in terms of short-term outcomes and comparable prognoses for acute MORC patients. For synchronous liver metastases, SEMS placement better prepares the patient for resection of the primary tumour and liver metastasis, which contribute to improved survival.

Image enhancement based on in vivo hyperspectral gastroscopic images: a case study

Hyperspectral imaging (HSI) has been recognized as a powerful tool for noninvasive disease detection in the gastrointestinal field. However, most of the studies on HSI in this field have involved ex vivo biopsies or resected tissues. We proposed an image enhancement method based on in vivo hyperspectral gastroscopic images. First, we developed a flexible gastroscopy system capable of obtaining in vivo hyperspectral images of different types of stomach disease mucosa. Then, depending on a specific object, an appropriate band selection algorithm based on dependence of information was employed to determine a subset of spectral bands that would yield useful spatial information. Finally, these bands were assigned to be the color components of an enhanced image of the object. A gastric ulcer case study demonstrated that our method yields higher color tone contrast, which enhanced the displays of the gastric ulcer regions, and that it will be valuable in clinical applications.

Clinical Values of Dental Floss Traction Assistance in Endoscopic Full-Thickness Resection for Submucosal Tumors Originating from the Muscularis Propria Layer in the Gastric Fundus

BACKGROUND

Endoscopic full-thickness resection (EFTR) derived from endoscopic submucosal dissection has gradually been accepted and even promoted for the treatment of submucosal tumors (SMTs) originating from the muscularis propria (MP) layer. However, there are some difficulties when EFTR is used to treat MP lesions in the gastric fundus. This study intends to explore whether EFTR can be made simpler, safer, and more effective with the traction assistance of dental floss.

METHODS

The clinical data of patients (trial group) with lesions in the MP layer in the gastric fundus undergoing EFTR with traction assistance of dental floss at Zhongshan Hospital, in 2016, were reviewed retrospectively. The control group was matched with the trial group according to tumor size. The differences in tumor resection time, patient hospitalization time, and complication rate were evaluated.

RESULTS

There was no significant difference in the average age of the two groups, each of which comprised 24 cases (58.7 ± 11.8 years versus 56.6 ± 7.9 years, t = 0.663, P = .511). However, there was a statistically significant difference in the operative time between the two groups (10.8 ± 2.8 minutes versus 19.0 ± 4.7 minutes, t = 7.298, P < .05). There was no statistically significant difference in the length of the postoperative hospital stay (3.2 ± 0.5 days versus 3.2 ± 0.5 days, t = 0.291, P = .772). In the trial group, there were 19 cases of gastrointestinal stromal tumors (group 1) and 5 cases of leiomyoma. The control group had similar results. Neither group experienced postoperative delayed bleeding, perforation, or other complications.

CONCLUSIONS

When EFTR is used to treat SMTs originating from the MP in the gastric fundus, dental floss traction assistance can relieve the tumor boundary to simplify the surgical procedure and save the operation time.

Long-term clinical outcomes of endoscopic submucosal dissection in rectal neuroendocrine tumors based on resection margin status: a real-world study

BACKGROUND

Endoscopic submucosal dissection (ESD) has been widely adopted in treating rectal neuroendocrine tumors (NETs). However, clinical outcomes in rectal NETs after ESD with different resection margin status remain scanty, particularly in patients with positive resection margins. This study aimed to evaluate the long-term clinical outcomes of ESD in rectal NET based on the resection margin status.

METHODS

This retrospective study included 436 patients diagnosed with rectal NET who had undergone ESD. Clinical data, including age, sex, tumor size, stage, invasion, and the resection margin status, were collected. Further, the patients were assessed for complications, recurrence, distant metastasis, and long-term outcomes.

RESULTS

Among all 436 patients, 395 patients had their primary ESD in our hospital. Complete resection was achieved in 319 patients. Patients who did not achieve complete resection opted for follow-up (n = 73), salvage surgery (n = 1) and salvage ESD (n = 2). Another 41 had their primary ESD in other hospital with incomplete resection and had salvage ESD in our hospital. All 436 patients had a median follow-up period of 61.4 months (range 33.4-125.3 months). During the follow-up period, two patients developed recurrences, while three patients developed metastasis. There were no significant differences in the 5-year progression-free survival and overall survival between patients with incomplete resection opting for follow-up compared to the other two groups (P = 0.5/0.8). However, the complication rates were significantly higher in patients who received salvage ESD.

CONCLUSION

This study demonstrated that positive resection margins have no influence on survival in patients with rectal NET treated using ESD.

Self-expandable metallic stent placement plus laparoscopy for acute malignant colorectal obstruction

AIM

To investigate the clinical advantages of the stent-laparoscopy approach to treat colorectal cancer (CRC) patients with acute colorectal obstruction (ACO).

METHODS

From April 2008 to April 2012, surgery-related parameters, complications, overall survival (OS), and disease-free survival (DFS) of 74 consecutive patients with left-sided CRC presented with ACO who underwent self-expandable metallic stent (SEMS) placement followed by one-stage open (n = 58) or laparoscopic resection (n = 16) were evaluated retrospectively. The stent-laparoscopy group was also compared with a control group of 96 CRC patients who underwent regular laparoscopy without ACO between January 2010 and December 2011 to explore whether SEMS placement influenced the laparoscopic procedure or reduced long-term survival by influencing CRC oncological characteristics.

RESULTS

The characteristics of patients among these groups were comparable. The rate of conversion to open surgery was 12.5% in the stent-laparoscopy group. Bowel function recovery and postoperative hospital stay were significantly shorter (3.3 ± 0.9 d vs 4.2 ± 1.5 d and 6.7 ± 1.1 d vs 9.5 ± 6.7 d, P = 0.016 and P = 0.005), and surgical time was significantly longer (152.1 ± 44.4 min vs 127.4 ± 38.4 min, P = 0.045) in the stent-laparoscopy group than in the stent-open group. Surgery-related complications and the rate of admission to the intensive care unit were lower in the stent-laparoscopy group. There were no significant differences in the interval between stenting and surgery, intraoperative blood loss, OS, and DFS between the two stent groups. Compared with those in the stent-laparoscopy group, all surgery-related parameters, complications, OS, and DFS in the control group were comparable.

CONCLUSION

The stent-laparoscopy approach is a feasible, rapid, and minimally invasive option for patients with ACO caused by left-sided CRC and can achieve a favorable long-term prognosis.