A prospective, randomized, double-blind, controlled trial on the efficacy of carbon dioxide insufflation in gastric endoscopic submucosal dissection

A prospective randomized controlled trial of the safety and efficacy of carbon dioxide insufflation compared with room air insufflation during gastric endoscopic submucosal dissection

BACKGROUND AND AIM

Carbon dioxide (CO₂ ) insufflation during gastric endoscopic submucosal dissection (GESD) under sedation can be used instead of room air insufflation. Appropriate monitoring of the partial pressure of CO₂ during GESD is necessary due to the impaired respiration. The aim of this study was to assess the safety and efficacy of CO₂ insufflation during GESD compared with conventional room air insufflation.

METHODS

Patients with a gastric epithelial neoplasm or early gastric cancer were enrolled. A total of 76 consecutive patients were randomly assigned to the CO₂ insufflation group (CO₂ group) or the room air insufflation group (air group). The primary outcome was the mean difference of end-tidal CO₂ (EtCO₂ ) between two groups.

RESULTS

The upper bound of the 95% CI for the mean EtCO₂ difference between the two groups before the procedure and at 15, 30 and 45 min after insufflation met the criteria for noninferiority. In a subgroup analysis of patients 70 years and older, the mean difference of EtCO₂ was not significantly different between two groups. However, the air group received more analgesics than the CO₂ group after the procedure (67.6% vs 35.1%, P = 0.005). In addition, in terms of improvement of abdominal pain or bowel gas after 24 h of GESD, CO₂ group showed better results than air group (both P < 0.05).

CONCLUSIONS

CO₂ insufflation during GESD is as safe as using room air, and patients, including elderly patients, receiving CO₂ achieve more rapid relief of abdominal pain and intra-abdominal residual gas during and after the procedure.

Relief Effect of Carbon Dioxide Insufflation in Transnasal Endoscopy for Health Checks-A Prospective, Double-Blind, Case-Control Trial

CO2 insufflation has proven effective in reducing patients’ pain after colonoscopies but has not been examined in esophagogastroduodenoscopies. Therefore, we examined the effect of CO2 insufflation in examinees who underwent transnasal endoscopies without sedation. This study is a single-center, prospective, double-blind, case-control trial conducted between March 2017 and August 2018. Subjects were assigned weekly to receive insufflation with either CO2 or air. The primary outcome was improvement of abdominal pain and distension at 2 h and 1-day postprocedure. In total, 336 and 338 examinees were assigned to the CO2 and air groups, respectively. Visual analog scale (VAS) scores for abdominal distension (15.4 vs. 25.5; p < 0.001) and distress from flatus (16.0 vs. 28.8; p < 0.001) at 2 h postprocedure were significantly reduced in the CO2 group. VAS scores for pain during the procedure (33.5 vs. 37.1; p = 0.059) and abdominal pain after the procedure (3.9 vs. 5.7; p = 0.052) also tended to be lower at 2 h postprocedure, but all parameters showed no significant difference at 1-day postprocedure. All procedures were safely completed through the planned program, and no apparent adverse events requiring treatment or follow-up occurred. In conclusion, CO2 insufflation may reduce postprocedural abdominal discomfort from transnasal esophagogastroduodenoscopies. (UMIN000028543).

Incidence rates, risk factors, and outcomes of aspiration pneumonia after gastric endoscopic submucosal dissection: A systematic review and meta-analysis

BACKGROUND AND AIM

The risk and prognosis of aspiration pneumonia (AP) after endoscopic submucosal dissection (ESD) are inconsistent among studies. We aim to estimate the incidence, risk factors, and outcome of AP in patients after gastric ESD.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Knowledge were searched for relevant articles from inception until April 2020. Data involving the incidence, risk factors, and outcomes were extracted. Pooled incidence, odds ratios (ORs), or standardized mean difference (SMD) and 95% confidence intervals (CIs) were calculated.

RESULTS

Forty records involving 48 674 subjects were finally included. The pooled incidence of AP after gastric ESD was 1.9% (95% CI, 1.2-2.7) via the double arcsine transformation method and 1.6% (1.1-2.5%) via the logit transformation method. Risk factors analyses revealed that old age (OR, 2.52; 95% CI, 1.99-3.18), comorbid pulmonary disease (2.49; 1.66-3.74), comorbid cerebrovascular disease (2.68; 1.05-6.85), remnant stomach (4.91; 1.83-13.14), sedation with propofol (2.51; 1.48-4.28), and long procedural duration (count data: 5.20, 1.25-21.7; measurement data: 1.01, 1.01-1.02) were related to the occurrence of AP. Patients with AP had a longer hospital stay (SMD, 0.56; 95% CI, 0.25-0.87) than those without AP.

CONCLUSIONS

About 1.9% (1.2-2.7%) of the patients who receive gastric ESD may develop AP, resulting in prolonged hospital stay. More attention should be paid in patients who are older; have comorbidities such as pulmonary diseases, cerebrovascular diseases, or gastric remnant; or require a long procedural duration or deep sedation with propofol.

Clinical value of submucosal tunneling endoscopic resection in submucosal tumors of the esophagus and cardia derived from the muscularis propria

BACKGROUND

Submucosal tunneling endoscopic resection (STER) is a new method for treating submucosal tumor in recent years, which is minimally invasive, with few complications and rapid recovery for patients. This study analyzed the data of patients who underwent this surgery at our hospital and explored the feasibility, effectiveness, and safety of this procedure for submucosal tumors.

AIM

To evaluate the efficacy, safety, and clinical value of STER in the treatment of submucosal tumors of the esophagus and cardia derived from the muscularis propria.

METHODS

Sixty patients who underwent STER for submucosal tumors of the esophagus and cardia derived from the muscularis propria were included. The results of endoscopic ultrasonography, procedure success rate, postoperative complications, postoperative pathological results, and postoperative follow-up data were recorded and analyzed statistically.

RESULTS

All of the cases completed the STER, with a success rate of 100%. The diameter of submucosal tumors was 1-5 cm. The operation took 31 to 123 min, and the average operation time was 81.73 min ± 23.23 min. The length of submucosal tunnel was 4-8 cm, with an average value of 5.88 cm ± 1.17 cm. Postoperative pathology confirmed that there were 42 cases of leiomyoma and 18 cases of stromal tumor. Two patients developed subcutaneous emphysema and right-side pneumothorax post operation, who were cured with conservative treatment. All cases were followed for 3 mo without any residual or recurrence of the lesion and no complications such as esophageal stenosis.

CONCLUSION

STER is effective in the treatment of submucosal tumors of the esophagus and cardia derived from the muscularis propria, with few complications and high safety.

Anesthetic Consideration for Peroral Endoscopic Myotomy

A recent achalasia guideline suggests that peroral endoscopic myotomy (POEM) is a safe option for achalasia that is as effective as Heller myotomy. It is recommended that POEM should be performed under general anesthesia. The incidence of adverse events such as bleeding, perforation, and carbon dioxide insufflation-related complications was lower in POEM under endotracheal general anesthesia than in POEM under sedation. Subcutaneous emphysema, pneumothorax, pneumomediastinum, pneumoperitoneum, and accompanying hemodynamic instability can be caused by carbon dioxide insufflation. Treatment of possible physiological changes and adverse events during the POEM procedure from the point of view of anesthesiologists may give endoscopists a new perspective on improving patient safety. The territory of therapeutic endoscopy can be expanded through cooperation with other departments, including anesthesia services. Efforts to understand different perspectives will certainly help not only secure patient safety but also expand the area of treatment.

Efficacy of submucosal bupivacaine injection for pain relief after endoscopic submucosal dissection: A multicenter, prospective, randomized controlled, and double-blind trial

BACKGROUND AND AIM

Although abdominal pain is a common adverse event related to endoscopic submucosal dissection (ESD), it can be sometimes underestimated by endoscopists. There are some endoscopic interventions available for the prevention of post-ESD pain, but their efficacy has not been established. We investigated whether a submucosal injection of bupivacaine (BP) can reduce procedure-related abdominal pain compared with the standard method.

METHODS

We performed a multicenter, double-blinded, randomized controlled trial of 86 adult patients referred for ESD as treatment for gastric neoplasms. Patients were randomly assigned to either the BP submucosal or conventional solution group. Questionnaires were collected when the study began (baseline) and immediately after ESD, as well as at 6, 12, and 24 hours post-operatively. The primary outcome was indicated by the visual analog scale (VAS) evaluated at 6 hours after procedure.

RESULTS

There were no significant differences in primary outcomes between groups and among all time points (immediately, 12, and 24 hours after ESD). The VAS and short-form McGill pain (SF-MP) scores were higher immediately after ESD than at 6, 12, or 24 hours post-operatively. The incidence of abdominal pain immediately after ESD was 94.0% (78/83) for all patients of both groups, and there was no significant difference between the 2 groups in the rate of abdominal pain immediately after ESD (BP group 37/40 [92.5%] versus non-BP group 41/43 [95.3%], P = .934). In univariable and multivariable analyses, BP did not have protective effect on post-ESD abdominal pain.

CONCLUSIONS

Submucosal BP injection does not promote pain relief or mitigate the effects of post-ESD abdominal pain.

Mallory-Weiss tear as a rare complication during esophageal endoscopic submucosal dissection

There are no previous reports of Mallory-Weiss tears occurring as complications during esophageal endoscopic submucosal dissection (ESD). We present 3 cases of Mallory-Weiss tears occurring during treatment of superficial squamous cell neoplasms through ESD. Carbon dioxide was used for air insufflation, and the patient was adequately sedated without retching or struggling during the operation. No significant bleeding from the lesion was observed during ESD; however, active bleeding caused by the Mallory-Weiss tear was identified endoscopically. Bleeding was controlled by closure of the tear with metal clips or repeated flushing with adrenaline saline. Hemorrhage did not recur until completion of the operation. Therefore, during the operation, it is necessary to maintain adequate depth of anesthesia and reduce the operation time, and also reduce air and water injections, to avoid occurrence of such complications.

COLONOSCOPY: RANDOMIZED COMPARATIVE STUDY OF INSUFFLATION WITH CARBON DIOXIDE VERSUS AIR

Background:

In Brazil, an increasing number of people are submitted to colonoscopy, either for screening or for therapeutic purposes.

Aim:

To evaluate whether there are advantages of using carbon dioxide (CO₂) over air for insufflation.

Methods:

Two hundred and ten of 219 patients were considered eligible for this study and were randomized into two groups according to the gas insufflation used: Air Group (n=104) and CO₂ Group (n=97). The study employed a double-blind design.

Results:

The Air and CO₂ Groups were similar in respect to bowel preparation evaluated using the Boston scale, age, gender, previous surgery, maneuvers necessary for the advancement of the device, and presence of polyps, tumors or signs of diverticulitis. However, “waking up with pain” and “pain at discharge” were more prevalent in the Air Group, albeit not statistically significant, with post-exam bloating seen only in the Air Group. The responses to a questionnaire, applied to analyze the late post-exam period, showed more comfort with the use of CO₂.

Conclusions:

The use of CO₂ is better than air as it avoids post-examination bloating, thereby providing greater comfort to patients.

CO2 insufflation versus air insufflation for endoscopic submucosal dissection: A meta-analysis of randomized controlled trials

Background

Carbon dioxide (CO₂) insufflation is increasingly used for endoscopic submucosal dissection (ESD) owing to the faster absorption of CO₂ as compared to that of air. Studies comparing CO₂ insufflation and air insufflation have reported conflicting results.

Objectives

This meta-analysis is aimed to assess the efficacy and safety of use of CO₂ insufflation for ESD.

Methods

Clinical trials of CO₂ insufflation versus air insufflation for ESD were searched in PubMed, Embase, the Cochrane Library and Chinese Biomedical Literature Database. We performed a meta-analysis of all randomized controlled trials (RCTs).

Results

Eleven studies which compared the use of CO₂ insufflation and air insufflation, with a combined study population of 1026 patients, were included in the meta-analysis (n = 506 for CO₂ insufflation; n = 522 for air insufflation). Abdominal pain and VAS scores at 6h and 24h post-procedure in the CO₂ insufflation group were significantly lower than those in the air insufflation group, but not at 1h and 3h after ESD. The percentage of patients who experienced pain 1h and 24h post-procedure was obviously decreased. Use of CO₂ insufflation was associated with lower VAS scores for abdominal distention at 1h after ESD, but not at 24h after ESD. However, no significant differences were observed with respect to postoperative transcutaneous partial pressure carbon dioxide (PtcCO₂), arterial blood carbon dioxide partial pressure (PaCO₂), oxygen saturation (SpO₂%), abdominal circumference, hospital stay, white blood cell (WBC) counts, C-Reactive protein (CRP) level, dosage of sedatives used, incidence of dysphagia and other complications.

Conclusion

Use of CO₂ insufflation for ESD was safe and effective with regard to abdominal discomfort, procedure time, and the residual gas volume. However, there appeared no significant differences with respect to other parameters namely, PtcCO₂, PaCO₂, SpO₂%, abdominal circumference, hospital stay, sedation dosage, complications, WBC, CRP, and dysphagia.

Carbon Dioxide versus Air Insufflation in Gastric Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background/Aims

Endoscopic submucosal dissection (ESD) with air insufflation is commonly used for the staging and treatment of early gastric carcinoma. However, carbon dioxide (CO₂) use has been shown to cause less post-procedural pain and fewer adverse events. The objective of this study was to compare the post-procedural pain and adverse events associated with CO₂ and air insufflation in ESD.

Methods

A systematic search was conducted for randomized control trials (RCTs) comparing the two approaches in ESD. The Mantel-Haenszel method was used to analyze the data. The mean difference (MD) and odds ratio (OR) were used for continuous and categorical variables, respectively.

Results

Four RCTs with a total of 391 patients who underwent ESD were included in our meta-analysis. The difference in maximal post-procedural pain between the two groups was statistically significant (MD, -7.41; 95% confidence interval [CI], -13.6 – -1.21; p=0.020). However, no significant differences were found in the length of procedure, end-tidal CO₂, rate of perforation, and postprocedural hemorrhage between the two groups. The incidence of overall adverse events was significantly lower in the CO₂ group (OR, 0.51; CI, 0.32–0.84; p=0.007).

Conclusions:

CO₂ insufflation in gastric ESD is associated with less post-operative pain and discomfort, and a lower risk of overall adverse events compared with air insufflation.

Tips for safety in endoscopic submucosal dissection for colorectal tumors

In Japan, endoscopic submucosal dissection (ESD) becomes one of standard therapies for large colorectal tumors. Recently, the efficacy of ESD has been reported all over the world. However, it is still difficult even for Japanese experts in some situations. Right-sided location, large tumor size, high degree of fibrosis, difficult manipulation is related with the difficulty. However, improvements on ESD devices, suitable strategies, and increase of operators' experiences enable us to solve these problems. In this chapter, we introduce recent topics about various difficult factors of colorectal ESD and the tips such as strategy, devices, injection, and traction method [Pocket-creation method (PCM) etc.].

Updated evidence on endoscopic resection of early gastric cancer from Japan

BACKGROUND

Endoscopic resection for early gastric cancer (EGC) plays a central role in the treatment of EGC in Japan. However, there is still room for improvement, and it is necessary to summarize the recently obtained knowledge from Japan for further improvement.

METHODS

We conducted a PubMed search to select relevant articles in the 5 years until September 18, 2016, using the keywords "gastric cancer" and "endoscopic treatment," "endoscopic submucosal dissection," "endoscopic mucosal resection," or "polypectomy" and filtering article types as "clinical study" or "clinical trial."

RESULTS

Among the 329 articles selected automatically from the keywords "polypectomy" (1 article), "endoscopic mucosal resection" (29 articles), "endoscopic submucosal dissection" (77 articles), and "endoscopic treatment" (222 articles) in combination with "gastric cancer," 32 relevant articles from Japanese investigators were chosen. Seven articles were categorized into "equipment," 4 into "preparation and sedation," 17 into "complications and their prevention," and 4 into "therapeutic outcomes." Among them, CO₂ insufflation, propofol sedation, and how to prevent post-endoscopic submucosal dissection (ESD) ulcer bleeding and achieve post-ESD ulcer healing were intensively investigated. Long-term outcomes of endoscopic mucosal resection and ESD were also reported as favorable outcomes.

CONCLUSIONS

Endoscopic resection for EGC is still developing toward an ideal form, pursuing a more reliable, safer, and faster minimally invasive treatment.

Complications of endoscopic resection techniques for upper GI tract lesions

Adverse events can occur during and after the endoscopic resection of upper gastrointestinal lesions. Their incidence can be minimized through the adoption of preventive measures and their final outcomes can be optimized through prompt identification and adequate treatment. In this evidence-based review we describe the risk factors for adverse events, preventive measures to avoid them and their management when they occur. Algorithms of action are also provided. Oesophageal strictures can be prevented with corticosteroids (either locally injected or systemically administered) and treated with endoscopic dilatation. Bleeding can be minimized through the adoption of prophylactic coagulation and novel preventive measures are emerging and being evaluated. Bleeding management includes coagulation therapy, clips and haemostatic powders. Perforations can nowadays be successfully treated endoscopically in the majority of the cases and conservative treatment is associated with favourable outcomes although optimal management is unclear.

Carbon dioxide insufflation in esophageal endoscopic submucosal dissection reduces mediastinal emphysema: A randomized, double-blind, controlled trial

AIM

To assess the efficacy of CO₂ insufflation for reduction of mediastinal emphysema (ME) immediately after endoscopic submucosal dissection (ESD).

METHODS

A total of 46 patients who were to undergo esophageal ESD were randomly assigned to receive either CO₂ insufflation (CO₂ group, n = 24) or air insufflation (Air group, n = 22). Computed tomography (CT) was carried out immediately after ESD and the next morning. Pain and abdominal distention were chronologically recorded using a 100-mm visual analogue scale (VAS). The volume of residual gas in the digestive tract was measured using CT imaging.

RESULTS

The incidence of ME immediately after ESD in the CO₂ group was significantly lower than that in the Air group (17% vs 55%, P = 0.012). The incidence of ME the next morning was 8.3% vs 32% respectively (P = 0.066). There were no differences in pain scores or distention scores at any post-procedure time points. The volume of residual gas in the digestive tract immediately after ESD was significantly smaller in the CO₂ group than that in the Air group (808 mL vs 1173 mL, P = 0.013).

CONCLUSION

CO₂ insufflation during esophageal ESD significantly reduced postprocedural ME. CO₂ insufflation also reduced the volume of residual gas in the digestive tract immediately after ESD, but not the VAS scores of pain and distention.

Effectiveness of clip-and-snare method using pre-looping technique for gastric endoscopic submucosal dissection

AIM: To evaluate efficacy and safety of clip-and-snare method using pre-looping technique (CSM-PLT) for gastric endoscopic submucosal dissection (ESD).

METHODS: In the CSM-PLT method, a clip attached to the lesion side was strangulated with a snare, followed by application of an appropriate tension to the lesion independent of an endoscope. Twenty consecutive lesions were resected by ESD using CSM-PLT (CSM-PLT group) and compared with a control group, including 20 lesions that were resected by conventional ESD. The control group was matched based on the size and location of the lesion, presence of pathologic fibrosis, and experience of endoscopists. Total procedure time of ESD, proportion of en bloc resection, and complications were analyzed.

RESULTS: The total procedure time for the CSM-PLT group was significantly shorter than that for the control group (38.5 min vs 59.5 min, P = 0.023); all lesions were resected en bloc by ESD. There was no significant difference in complications between the two groups. Moreover, there was no complication in the CSM-PLT group. In one large lesion (size: 74 mm) that underwent extensive CSM-PLT during ESD, we used an additional CSM-PLT on another edge of the lesion after achieving submucosal resection to the maximum extent possible during initial CSM-PLT. In two lesions, the snare came off the lesion together with the clip after a sudden pull; nevertheless, ESD was successful in all lesions.

CONCLUSION: CSM-PLT was an effective and safe method for gastric ESD.

Submucosal tunneling endoscopic resection for gastrointestinal submucosal tumors originating from the muscularis propria layer

Submucosal tunneling endoscopic resection (STER) is a novel endoscopic technique for gastrointestinal submucosal tumors (SMT) originating from the muscularis propria layer, and has been proved to be effective by clinical studies. STER was initially created for esophageal and cardia SMT, but its indications have expanded due to the implication and modification of this technique. Herein, we review the indications, procedure, efficacy and complications of STER.

Clinical outcomes of and management strategy for perforations associated with endoscopic submucosal dissection of an upper gastrointestinal epithelial neoplasm

INTRODUCTION

Perforation is one of the major complications of endoscopic submucosal dissection (ESD). In the present study, we investigated the clinical outcomes of and management strategies for ESD-related perforations.

METHODS

Between February 2010 and April 2014, a total of 3821 patients who underwent ESD for an upper gastrointestinal epithelial neoplasm were analyzed using the Yonsei University Severance Hospital database. Clinical outcomes of and management strategies for perforations in 90 patients (2.4 %) were analyzed. The risk factors for the development of perforation were also investigated.

RESULTS

The mean age of our subjects was 64.7 ± 12.2 years (male to female ratio, 3.2:1), and the mean size of the resected specimens was 39.4 ± 12.5 mm. Endoscopically visible perforations (visible perforation group) were noted in 74 of the 90 patients (82.2 %), and clinically suspected perforations (suspected perforation group) were noted in 16 patients (17.8 %). Immediate closure with endoclips was attempted in cases with a visible perforation and was successful in 72 (97.3 %) cases. Two patients in whom endoscopic closure failed underwent surgery. Conservative care, including fasting and intravenous antibiotic administration, was attempted in the suspected perforation group, and all the patients were treated successfully without surgery. The mean durations of fasting, antibiotic treatment, and hospital stay were 3.8 ± 3.1, 6.8 ± 4.2, and 8.7 ± 5.3 days, respectively. Subgroup analysis of perforation type (visible perforation vs. suspected perforation) revealed no significant difference in the clinical course. Tumor location at the upper or middle third of the stomach was significantly associated with perforation.

CONCLUSION

Most of the ESD-related perforations in upper gastrointestinal epithelial neoplasm could be managed successfully in a non-surgical manner under strict monitoring.

Percutaneous endoscopic gastrostomy under steady pressure automatically controlled endoscopy: First clinical series

AIM: To elucidate the safety of percutaneous endoscopic gastrostomy (PEG) under steady pressure automatically controlled endoscopy (SPACE) using carbon dioxide (CO₂).

METHODS: Nine patients underwent PEG with a modified introducer method under conscious sedation. A T-tube was attached to the channel of an endoscope connected to an automatic surgical insufflator. The stomach was inflated under the SPACE system. The intragastric pressure was kept between 4-8 mmHg with a flow of CO₂ at 35 L/min. Median procedure time, intragastric pressure, median systolic blood pressure, partial pressure of CO₂, abdominal girth before and immediately after PEG, and free gas and small intestinal gas on abdominal X-ray before and after PEG were recorded.

RESULTS: PEG was completed under stable pneumostomach in all patients, with a median procedural time of 22 min. Median intragastric pressure was 6.9 mmHg and median arterial CO₂ pressure before and after PEG was 42.1 and 45.5 Torr (NS). The median abdominal girth before and after PEG was 68.1 and 69.6 cm (NS). A mild free gas image after PEG was observed in two patients, and faint abdominal gas in the downstream bowel was documented in two patients.

CONCLUSION: SPACE might enable standardized pneumostomach and modified introducer procedure of PEG.

Efficacy of carbon dioxide insufflation during gastric endoscopic submucosal dissection: a randomized, double-blind, controlled, prospective study

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is commonly performed under air insufflation and is often accompanied by abdominal discomfort. CO2 is absorbed more rapidly by the body than is air; however, the use of CO2 insufflation in ESD remains controversial. This randomized, double-blind, controlled, prospective study was designed to assess the efficacy of CO2 versus air insufflation in gastric ESD.

METHODS

Between May 2012 and August 2014, a total of 110 patients with gastric tumors were randomly assigned to the CO2 insufflation (CO2 group, n = 54) or air insufflation group (air group, n = 56). Abdominal pain after ESD was chronologically recorded via visual analog scale (VAS) scores. Secondary outcome measurements were adverse events, abdominal circumference, amount of sedatives prescribed, and use of analgesics.

RESULTS

Neither the baseline patient characteristics nor the mean procedural time differed between the groups. The VAS score for abdominal pain was 35.2 in the CO2 insufflation group versus 48.5 in the air insufflation group 1 hour after ESD (P = .026), 27.8 versus 42.5 three hours after ESD (P = .007), 18.4 versus 34.8 six hours after ESD (P = .001), and 9.2 versus 21.9 one day after ESD (P < .001). Changes in abdominal circumference, the amounts of sedative drugs taken, and the adverse events did not differ between the groups. However, the air insufflation group required more analgesics than did the CO2 insufflation group (CO2 group, 22.0% [11/50]; air group, 42.3% [22/52]; P = .028).

CONCLUSIONS

CO2 insufflation during gastric ESD significantly reduced abdominal pain and analgesic usage compared with air insufflation. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01579071.)

Circumferential distribution and location of Mallory-Weiss tears: recent trends

BACKGROUND AND STUDY AIMS

Mallory-Weiss tears (MWTs) are not only a common cause of acute nonvariceal gastrointestinal bleeding but also an iatrogenic adverse event related to endoscopic procedures. However, changes in the clinical characteristics and endoscopic features of MWTs over the past decade have not been reported. The aim of this study was to investigate recent trends in the etiology and endoscopic features of MWTs.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of patients with a diagnosis of MWT at our university hospital between August 2003 and September 2013. The information regarding etiology, clinical parameters, endoscopic findings, therapeutic interventions, and outcome was reviewed.

RESULTS

A total of 190 patients with MWTs were evaluated. More than half (n = 100) of the cases occurred during endoscopic procedures; cases related to alcohol consumption were less frequent (n = 13). MWTs were most frequently located in the lesser curvature of the stomach and right lateral wall (2 - to 4-o'clock position) of the esophagus, irrespective of the cause. The condition of more than 90 % of the patients (n = 179) was improved by conservative or endoscopic treatment, whereas 11 patients (5.8 %) required blood transfusion. Risk factors for blood transfusion were a longer laceration (odds ratio [OR] 2.3) and a location extending from the esophagus to the stomach (OR 5.3).

CONCLUSIONS

MWTs were frequently found on the right lateral wall (2 - to 4-o'clock position) of the esophagus aligned with the lesser curvature of the stomach, irrespective of etiology. Longer lacerations extending from the esophagus to the gastric cardia were associated with an elevated risk for bleeding and requirement for blood transfusion.

Safety and efficacy of carbon dioxide insufflation during gastric endoscopic submucosal dissection

AIM: To compare the safety and efficacy of carbon dioxide (CO₂) and air insufflation during gastric endoscopic submucosal dissection (ESD).

METHODS: This study involved 116 patients who underwent gastric ESD between January and December 2009. After eliminating 29 patients who fit the exclusion criteria, 87 patients, without known pulmonary dysfunction, were randomized into the CO₂ insufflation (n = 36) or air insufflation (n = 51) groups. Standard ESD was performed with a CO₂ regulation unit (constant rate of 1.4 L/min) used for patients undergoing CO₂ insufflation. Patients received diazepam for conscious sedation and pentazocine for analgesia. Transcutaneous CO₂ tension (PtcCO₂) was recorded 15 min before, during, and after ESD with insufflation. PtcCO₂, the correlation between PtcCO₂ and procedure time, and ESD-related complications were compared between the two groups. Arterial blood gases were analyzed after ESD in the first 30 patients (12 with CO₂ and 18 with air insufflation) to assess the correlation between arterial blood CO₂ partial pressure (PaCO₂) and PtcCO₂.

RESULTS: There were no differences in respiratory functions, median sedative doses, or median procedure times between the groups. Similarly, there was no significant difference in post-ESD blood gas parameters, including PaCO₂, between the CO₂ and air groups (44.6 mmHg vs 45 mmHg). Both groups demonstrated median pH values of 7.36, and none of the patients exhibited acidemia. No significant differences were observed between the CO₂ and air groups with respect to baseline PtcCO₂ (39 mmHg vs 40 mmHg), peak PtcCO₂ during ESD (52 mmHg vs 51 mmHg), or median PtcCO₂ after ESD (50 mmHg vs 50 mmHg). There was a strong correlation between PaCO₂ and PtcCO₂ (r = 0.66; P < 0.001). The incidence of Mallory-Weiss tears was significantly lower with CO₂ insufflation than with air insufflation (0% vs 15.6%, P = 0.013). CO₂ insufflation did not cause any adverse events, such as CO₂ narcosis or gas embolisms.

CONCLUSION: CO₂ insufflation during gastric ESD results in similar blood gas levels as air insufflation, and also reduces the incidence of Mallory-Weiss tears.

Peroral endoscopic myotomy: an evolving treatment for achalasia

Peroral endoscopic myotomy (POEM) was first performed in Japan in 2008 for uncomplicated achalasia. With excellent results, it was adopted by highly skilled endoscopists around the world and the indications for POEM were expanded to include advanced sigmoid achalasia, failed surgical myotomy, patients with previous endoscopic treatments and even other spastic oesophageal motility disorders. With increased uptake and performance of POEM, variations in technique and improved management of adverse events have been developed. Now, 6 years since the first case and with >3,000 procedures performed worldwide, long-term data has shown the efficacy of POEM to be long-lasting. A growing body of literature also exists pertaining to the learning curve, application of novel technologies, extended indications and physiologic changes with POEM. Ultimately, this once experimental procedure is evolving towards becoming the preferred treatment for achalasia and other spastic oesophageal motility disorders.

Risk of lens cloudiness during colorectal endoscopic submucosal dissection and ability of a novel lens cleaner to maintain and restore endoscopic view

BACKGROUND AND AIM

Generally, colorectal endoscopic submucosal dissection (ESD) cannot be carried out with severe lens cloudiness. We examined the occurrence of lens cloudiness during ESD as well as the efficacy of a novel cleaner for it.

METHODS

This study was a prospective study compared to historical control. First, we analyzed 103 ESD cases using standard cleaner at the Kyoto Prefectural University of Medicine in 2012. Relationship between lens cloudiness and clinical characteristics of lesions was analyzed. Lens cloudiness was recorded as grade 0 (clear) to grade 2 (very unclear). Then, we recruited 92 consecutive patients who underwent colorectal ESD using the novel cleaner from August 2013 to July 2014. The cleaner was applied on top of the lens before procedure and ability to prevent lens cloudiness was tested. Additionally, the novel cleaner was injected from endoscopic channel into a space created by endoscopic hood and colonic wall in seven cases with grade 1 or 2 of lens cloudiness and the ability to clean lens cloudiness inside the colon was tested.

RESULTS

Rate of severe lens cloudiness was 8.7%. Multivariate analysis showed that severe lens cloudiness was related with severe submucosal fatty tissue (P < 0.001). The novel cleaner had significantly less cloudiness cases compared to the standard cleaner (14.1% vs 33.0%, P = 0.002). Additionally, the novel cleaner enabled us to clean lens cloudiness in all seven cases.

CONCLUSION

Lens cloudiness during ESD was associated with submucosal fatty tissue. Effective lens cleaner should be used to prevent and clean lens cloudiness.

Future directions of duodenal endoscopic submucosal dissection

Endoscopic therapies for lesions of the duodenum are technically more difficult than those for lesions of the other parts of the gastrointestinal tract due to the anatomical features of the duodenum, and the incidence rate of complications such as perforation and bleeding is also higher. These aforementioned trends were especially noticeable for the case of duodenal endoscopic submucosal dissection (ESD). The indication for ESD of duodenal tumors should be determined by assessment of the histopathology, macroscopic morphology, and diameter of the tumors. The three types of candidate lesions for endoscopic therapy are adenoma, carcinoma, and neuroendocrine tumors. For applying endoscopic therapies to duodenal lesions, accurate preoperative histopathological diagnosis is necessary. The most important technical issue in duodenal ESD is the submucosal dissection process. In duodenal ESD, a short needle-type knife is suitable for the mucosal incision and submucosal dissection processes, and the Small-caliber-tip Transparent hood is an important tool. After endoscopic therapies, the wound should be closed by clipping in order to prevent complications such as secondary hemorrhage and delayed perforation. At present, the criteria for selection between ESD and EMR vary among institutions. The indications for ESD should be carefully considered. Duodenal ESD should have limitations, such as the need for its being performed by experts with abundant experience in performing the procedure.

Safety of carbon dioxide insufflation during gastric endoscopic submucosal dissection in patients with pulmonary dysfunction under conscious sedation

BACKGROUND

Carbon dioxide (CO2) insufflation is effective for gastric endoscopic submucosal dissection (ESD). However, its safety is unknown in patients with pulmonary dysfunction. This study aimed to investigate the safety of CO2 insufflation during gastric ESD in patients with pulmonary dysfunction under conscious sedation.

METHODS

We analyzed 322 consecutive patients undergoing ESD using CO2 insufflation (1.4 L/min) for gastric lesions. Pulmonary dysfunction was defined as a forced expiratory volume in 1.0 s/forced vital capacity (FEV1.0%) <70% or vital capacity <80%. Transcutaneous partial pressure of CO2 (PtcCO2) was recorded before, during, and after ESD.

RESULTS

In total, 127 patients (39%) had pulmonary dysfunction. There were no significant differences in baseline PtcCO2 before ESD, peak PtcCO2 during ESD, and median PtcCO2 after ESD between the pulmonary dysfunction group and normal group. There was a significant correlation between PtcCO2 elevation from baseline and ESD procedure time (r = 0.22, P < 0.05) only in the pulmonary dysfunction group. In patients with FEV1.0% <60%, the correlation was much stronger (r = 0.39, P < 0.05). Neither the complication incidences nor the hospital stay differed between the two groups. CO2 narcosis or gas embolism was not reported in either group.

CONCLUSIONS

CO2 insufflation during gastric ESD in patients with pulmonary dysfunction under conscious sedation is safe with regard to complication risk and hospital stay. However, in patients with severe obstructive lung disease, especially in those with FEV1.0% <60%, longer procedure time may induce CO2 retention, thus requiring CO2 monitoring.

Endoscopic therapy for early gastric cancer: Standard techniques and recent advances in ESD

The technique of endoscopic submucosal dissection (ESD) is now a well-known endoscopic therapy for early gastric cancer. ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate. However, the drawback of ESD is its technical difficulty, and, consequently, it is associated with a high rate of complications, the need for advanced endoscopic techniques, and a lengthy procedure time. Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks.

A double-blind, block-randomized, placebo-controlled trial to identify the chemical assistance effect of mesna submucosal injection for gastric endoscopic submucosal dissection

BACKGROUND

Previous animal studies and a pilot clinical trial demonstrated that submucosal injection of a thiol compound called mesna could chemically soften connective tissues and thus facilitate endoscopic submucosal dissection (ESD).

OBJECTIVE

To evaluate whether mesna injection could reduce procedural times for gastric ESD.

DESIGN

Double-blind, block-randomized, controlled trial.

SETTING

University hospital.

PATIENTS

A total of 101 patients with superficial gastric cancer indicated for ESD were enrolled and randomly assigned to either the mesna or control (saline solution) group.

INTERVENTION

Traditional ESD was performed with a single bolus injection of mesna or saline solution.

MAIN OUTCOME MEASUREMENTS

Time for submucosal dissection (TSD).

RESULTS

En bloc resection was achieved for all lesions in the mesna group (53/53) and 51 of 52 lesions (98.08%) in the control group. TSD was not statistically different between the groups (18.62 ± 13.9 [mean ± SD] minutes for the mesna group and 24.58 ± 24.55 [mean ± SD] minutes for the control group; P = .128), and there were fewer time-consuming cases (times over 30 minutes) in the mesna group compared with controls (7/53 vs 15/52; P = .049). Multivariate regression analysis demonstrated that use of mesna, specimen size, and the presence of fibrous scars were significantly correlated with TSD (P < .05).

LIMITATIONS

Single-center study.

CONCLUSION

TSD was not significantly different between the mesna and control injection groups, but multivariate analysis indicated that mesna injection reduced procedural challenges associated with the submucosal dissection. (

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000003786.).

Is the type of insufflation a key issue in gastro-intestinal endoscopy?

Endoscopic procedures continue to play an emerging role in diagnosing and treating upper and lower gastrointestinal (GI) disorders. In particular, the introduction of colonoscopy in bowel cancer screening has underlined its promising role in decreasing the incidence of colorectal cancer and reducing tumour related mortality. To achieve these goals patients need to contemplate endoscopic examinations as painless and fearless procedures. The use of carbon dioxide (CO₂) as an alternative insufflation gas in comparison to air has been considered as an essential key to improving patients' acceptance in undergoing endoscopic procedures. CO₂ is absorbed quickly through the bowel mucosa causing less luminal distension and potentially less abdominal pain. However, its exact role has not been defined completely. In particular, the beneficial use of CO₂ in upper GI endoscopy and in sedated patients is still conflicting. In the present review, we aimed to assess the current evidence for using CO₂ in endoscopy and to evaluate its potential role in the future.