State of the art on endoscopic mucosal resection and endoscopic submucosal dissection

Evaluations on laser ablation of ex vivo porcine stomach tissue for development of Ho:YAG-assisted endoscopic submucosal dissection (ESD)

Endoscopic submucosal dissection (ESD) is clinically used to remove early gastric cancer in stomach. The aim of the current study is to examine a therapeutic capacity of pulsed Ho:YAG laser for the development of laser-assisted ESD under various surgical parameters. Ex vivo porcine stomach tissue was ablated with 1-J Ho:YAG pulses at 10 Hz at different number of treatments (NT = 1, 2, and 3) and treatment speeds (TS = 0.5, 1, and 2 mm/s) without and with saline injection. Regardless of saline injection, straight tissue ablation showed that ablation depth increased with increasing NT and decreasing TS. At NT = 3 and TS = 0.5 mm/s, no saline injection yielded the maximum ablation depth (3.4 ± 0.3 mm), partially removing muscularis propria. However, saline injection confined the tissue ablation within a submucosal layer (2.1 ± 0.3 mm). Thermal injury was found to be 0.7~1.1 mm in the adjacent tissue with superficial carbonization. Circular tissue ablation (2 cm in diameter) at NT = 3 and TS = 0.5 mm/s presented that no saline injection yielded a reduction in the lesion area, whereas saline injection maintained the ablated lesion area. Histological analysis revealed that unlike no saline injection, saline injection ablated the entire mucosal layer without perforation in the muscular propria. The pulsed Ho:YAG laser can be a potential surgical tool for clinical ESD to incise a target lesion without adverse perforation. Further investigations will validate the efficacy and safety of the Ho:YAG laser-assisted ESD in in vivo porcine stomach models for clinical translation.

Efficacy and Safety of a Novel Submucosal Injection Solution for Resection of Gastrointestinal Lesions

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are minimally invasive and efficient techniques for the removal of gastrointestinal (GI) mucosal polyps. In both techniques, submucosal injection solutions are necessary for complete effectiveness and safety during the intervention to be obtained. The main objective of this study was to evaluate the efficacy and safety of a new sterile submucosal injection solution for EMR/ESD used within a clinical protocol in patients with intestinal polyps. We carried out a prospective study between 2016 and 2017 with patients who attended the Endoscopy Consultation—Digestive Department of Primary Hospital. Patients were selected for EMR/ESD after the application of clinical protocols. Thirty-six patients were selected (≥ 66 years with comorbidities and risk factors). Lesions were located mainly in the colon. Our solution presented an intestinal lift ≥ 60 min in EMR/ESD and a high expansion of tissue, optimum viscosity, and subsequent complete resorption. The genes S100A9 and TP53 presented an expression increase in the distal regions. TP53 and PCNA were the only genes whose expression was increased in polyp specimens vs. the surrounding tissue at the mRNA level. In EMR/ESD, our solution presented a prolonged effect at the intestinal level during all times of the intervention. Thus, our solution seems be an effective and safe alternative in cases of flat lesions in both techniques.

Closing the Gaps: Endoscopic Suturing for Large Submucosal and Full-Thickness Defects

This article is a systematic review of relevant literature on endoscopic suturing as a primary closure technique for large submucosal and full-thickness defects after endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and endoscopic full-thickness resection (EFTR). A comprehensive literature search was conducted through 2016 by using PubMed, to find peer-reviewed original articles. The specific factors considered were the procedural indications and details, success rates, clinical outcomes including complications, and study limitations. Six original articles were included in the final review: two with non-human subjects and four with human subjects. The mean success rate of endoscopic suturing was 97.4% (100% for human subjects and 95.4% for non-human subjects). The procedural time ranged from 7 to 89 min. The average size and depth of lesions were 2.71 cm (3.74 cm [human] and 1.96 cm [non-human]) and 1.52 cm, respectively. The technique itself had no reported impact on mortality. In conclusion, endoscopic suturing is a minimally invasive technique for the primary closure of defects caused by EMR, ESD, and EFTR, with a high success and low complication rate.

Efficacy of a new hemostatic forceps during gastric endoscopic submucosal dissection: A prospective randomized controlled trial

BACKGROUND AND AIM

Currently, endoscopic submucosal dissection (ESD) is a widely accepted standard treatment for early gastric cancer, but one challenging aspect of ESD is hemostasis. We developed a new hemostatic forceps (FD-Y0007) with the aim of achieving more effective hemostasis and investigated the hemostatic ability of the FD-Y0007 during gastric ESD in humans.

METHODS

This study was a prospective randomized controlled trial, which was conducted at a cancer referral center. Sixty-six patients who were scheduled to undergo ESD were enrolled and randomly assigned to either the Coagrasper or the FD-Y0007, which was used for hemostasis throughout the case. The primary end point was the time required to obtain hemostasis, which was measured for the first episode of bleeding during each case.

RESULTS

Hemostasis time for the first bleeding episode during ESD was 73.0 s for the Coagrasper and 21.5 s for the FD-Y0007 (P < 0.001). When all episodes of bleeding were included, hemostasis time was 56.8 s in the Coagrasper group and 25.5 s in FD-Y0007group (P < 0.0001). The frequency of adverse events (perforation: 3.4% vs 7.1%; delayed bleeding: 0% vs 0%) was not significantly different between the two groups.

CONCLUSIONS

Compared with the Coagrasper, the FD-Y0007 efficiently reduces the hemostatic time during gastric ESD with no increase in adverse events.

Review article: the investigation and management of rectal neuroendocrine tumours

BACKGROUND

Rectal neuroendocrine tumours (NETs) are increasingly identified at endoscopy possibly as a result of bowel cancer screening programmes.

AIM

To present a review of the literature to aid clinicians in the diagnosis and management of rectal neuroendocrine tumours.

METHODS

A literature search was conducted through MEDLINE using search terms: rectal, rectum, carcinoid, NET, therapy, endoscopy, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles.

RESULTS

The incidence of rectal neuroendocrine tumours is approximately 1 per 100 000 population per year with the majority (80-90%) being <1 cm and localised to the submucosa. Metastatic disease is infrequent (<20%) with risk factors including size, atypical appearance, grade and depth of invasion. The primary resection modality influences complete resection rates and the need for secondary therapy. A thorough pre-resection diagnostic work up is required for lesions that are at higher risk of invasion and metastasis. Device-assisted endoscopic mucosal resection and endoscopic submucosal dissection are used to resect localised rectal neuroendocrine tumours <2 cm. Transanal surgery is also used to resect localised 1-2 cm rectal neuroendocrine tumours. Oncological surgical resection is used for rectal neuroendocrine tumours that are >2 cm or with invasion and regional disease. The treatment of advanced disease is multimodal.

CONCLUSIONS

The long-term tumour biology of small rectal neuroendocrine tumours remains unclear. There is uncertain impact from bowel cancer screening programmes on rectal neuroendocrine tumour incidence, morbidity and mortality. Referral to neuroendocrine tumour centres for patients with locally advanced disease or metastatic disease is recommended.

New endoscopic platform for endoluminal en bloc tissue resection in the gastrointestinal tract (with videos)

BACKGROUND

Endoscopic removal of gastrointestinal tract lesions is increasingly popular around the world. We evaluated feasibility, safety, effectiveness, and user learning curve of new endoscopic platform for complex intraluminal interventions.

METHODS

A novel system, consisting of expandable working chamber with two independent instrument guides (LIG), was inserted into colon. Simulated colonic lesions were removed with endoscopic submucosal (ESD) and submuscular (ESmD) dissection.

RESULTS

In all nine in vivo models, an intraluminal chamber and its dynamic tissue retractors (via LIG) provided a stable working space with excellent visualization and adequate access to target tissue. Endoscopic platform facilitated successful completion of 11 en bloc ESDs (mean size 43.0 ± 11.3 mm, mean time 46.3 ± 41.2 min) and eight ESmD (mean size 50.0 ± 14.1 mm, mean time 48.0 ± 21.2 min). The learning curve for ESD using this platform demonstrated three phases: rapid improvement in procedural skills took place during the first three procedures (mean ESD time 98.7 ± 40.0 min). A plateau phase then occurred (procedures 4-7) with mean procedure time 42.0 ± 13.4 min (p = 0.04), followed by another sharp improvement in procedural skills (procedures 8-11) requiring only 16.3 ± 11.4 min (p = 0.03) to complete ESD. Especially dramatic (p = 0.002) was the time difference between the first three procedures (mean time 98.7 ± 40.0 min) and subsequent eight procedures (mean time 29.1 ± 17.9 min).

CONCLUSIONS

A newly developed endoscopic platform provides stable intraluminal working space, dynamic tissue retraction, and instrument triangulation, improving visualization and access to the target tissue for safer and more effective en bloc endoscopic submucosal and submuscular dissection. The learning curve for ESD was markedly facilitated by this new endoscopic platform.

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.

Diagnostic Accuracy of Mucosal Biopsy versus Endoscopic Mucosal Resection in Barrett's Esophagus and Related Superficial Lesions

Background. Endoscopic surveillance for early detection of dysplastic or neoplastic changes in patients with Barrett's esophagus (BE) depends usually on biopsy. The diagnostic and therapeutic role of endoscopic mucosal resection (EMR) in BE is rapidly growing. Objective. The aim of this study was to check the accuracy of biopsy for precise histopathologic diagnosis of dysplasia and neoplasia, compared to EMR in patients having BE and related superficial esophageal lesions. Methods. A total of 48 patients with previously diagnosed BE (36 men, 12 women, mean age 49.75 ± 13.3 years) underwent routine surveillance endoscopic examination. Biopsies were taken from superficial lesions, if present, and otherwise from BE segments. Then, EMR was performed within three weeks. Results. Biopsy based histopathologic diagnoses were nondysplastic BE (NDBE), 22 cases; low-grade dysplasia (LGD), 14 cases; high-grade dysplasia (HGD), 8 cases; intramucosal carcinoma (IMC), two cases; and invasive adenocarcinoma (IAC), two cases. EMR based diagnosis differed from biopsy based diagnosis (either upgrading or downgrading) in 20 cases (41.67%), (Kappa = 0.43, 95% CI: 0.170–0.69). Conclusions. Biopsy is not a satisfactory method for accurate diagnosis of dysplastic or neoplastic changes in BE patients with or without suspicious superficial lesions. EMR should therefore be the preferred diagnostic method in such patients.

Endoscopic suturing closure of large mucosal defects after endoscopic submucosal dissection is technically feasible, fast, and eliminates the need for hospitalization (with videos)

BACKGROUND

Endoscopic submucosal dissection (ESD) is less invasive than surgical resection, but the large mucosal defects after ESD may lead to adverse events necessitating hospitalizations.

OBJECTIVE

To evaluate the use of an endoscopic suturing device for closure of large mucosal defects after ESD.

DESIGN AND SETTING

Retrospective, single-center study.

PATIENTS

Twelve consecutive patients underwent ESD.

INTERVENTIONS

All lesions were removed by using a previously described ESD technique. The large mucosal defects post-ESD were completely closed with the endoscopic suturing device, and all patients were discharged home with subsequent clinical and endoscopic follow-up.

MAIN OUTCOME MEASUREMENTS

Bleeding and perforation rates after ESD with mucosal defect closure.

RESULTS

ESD followed by endoscopic suturing of the mucosal defects was performed in 12 patients (mean age, 64.7 ± 11.2 years, 4 lesions in the stomach, 8 lesions in the colon; mean lesion size, 42.5 ± 14.8 mm) over a period of 8 months. All lesions (100%) were removed en bloc. Closure of post-ESD defects with an endoscopic suturing device was technically feasible and fast (mean closure time, 10.0 ± 5.8 minutes per patient). Only 1 stitch (continuous suturing line) was required for complete closure in 8 patients. In the other 4 patients, the mucosal defect was closed with 2 to 4 separate stitches (mean number of sutures per patient, 1.6 ± 1.0). There were no immediate or delayed adverse events in any of the study patients.

LIMITATIONS

Retrospective study.

CONCLUSIONS

Closure of large post-ESD defects with the Overstitch endoscopic suturing device is technically feasible and fast and can significantly decrease treatment cost by eliminating the need for hospitalization.

rhEGF-containing thermosensitive and mucoadhesive polymeric sol–gel for endoscopic treatment of gastric ulcer and bleeding

Gastrointestinal endoscopy is a standard diagnostic tool for gastrointestinal ulcers and cancer. In this study, we have developed recombinant human epidermal growth factor-containing ulcer-coating polymeric sol–gel for endoscopic application. Chitosan and pluronic F127 were employed for their thermoresponsive and bioadhesive properties. At temperatures below 21℃, polymeric sol–gel remains liquid during endoscopic application and transforms to gel at body temperature after application on ulcers. In an in vitro cellular wounding assay, recombinant human epidermal growth factor sol–gel significantly enhanced the cell migration and decreased the wounding area (68%) compared to nontreated, recombinant human epidermal growth factor solution, and sol–gel without recombinant human epidermal growth factor (42, 49, and 32 % decreased at day 1). The in vivo ulcer-healing study was performed in an acetic acid-induced gastric ulcer rat model and proved that our recombinant human epidermal growth factor endoscopic sol–gel facilitated the ulcer-healing process more efficiently than the other treatments. Ulcer sizes in the recombinant human epidermal growth factor sol–gel group were decreased 2.9- and 2.1-fold compared with those in the nontreated group on days 1 and 3 after ulceration, respectively. The mucosal thickness in the recombinant human epidermal growth factor sol–gel group was significantly increased compared to that in the nontreated group (3.2- and 6.9-fold on days 1 and 3 after ulceration, respectively). In a gastric retention study, recombinant human epidermal growth factor sol–gel stayed on the gastric mucosa more than 2 h after application. The present study suggests that recombinant human epidermal growth factor sol–gel is a prospective candidate for treating gastric ulcers via endoscopic application.

Endoscopic resection for gastrointestinal neuroendocrine tumors

Gastrointestinal (GI) and neuroendocrine tumors (NETs) can be treated by mini-invasive endoscopic resection when localized in the superficial layers of the bowel wall and their size is <20 mm. Endoscopic diagnosis of NETs is usually incidental or suspected after clinical, laboratory or imaging findings. Endoscopic mucosal resection is the most commonly used technique for NET removal, endoscopic submucosal dissection is indicated in selected cases, while papillectomy is feasible for ampullary lesions. Histopathologic assessment of the resection margin (circumferential and deep) is important for staging. Incidence of endoscopic mucosal resection-/endoscopic submucosal dissection-related complications for removal of GI NETs are similar to those reported for other GI lesions. Endoscopic follow-up is based on histopathologic characteristics of the resected NETs and its site. NETs >20 mm in size, with penetration of the muscle layer and/or serosa are at high risk for metastases and surgical approach is recommended when feasible.

Laterally spreading tumors in the colon and rectum

The large and relatively flat colorectal neoplastic lesions called laterally spreading tumors are classified as nonpolypoid despite some mixed patterns with protruding nodules. Large hyperplastic polyps and sessile serrated lesions are non-neoplastic lesions that also have this morphology and may potentially progress to neoplasia. All these large and relatively flat lesions are more frequent in the proximal colon and less conspicuous than polypoid lesions. Their underdiagnosis is a major factor in the failure of colonoscopy to prevent cancer in the proximal colon. The treatment of laterally spreading tumors by endoscopic resection (endoscopic mucosal resection, piecemeal endoscopic mucosal resection, endoscopic submucosal dissection), or by surgery is based on a careful morphologic analysis, taking into account the size and surface with nodules or depression. The technique of endoscopic submucosal dissection should be diffused because it reduces the number of surgical indications.

Clinical outcomes and factors related to resectability and curability of EMR for early colorectal cancer

BACKGROUND

EMR has emerged as an alternative therapeutic option for selected cases of early colorectal cancer (ECC). However, the factors associated with resectability and curability of EMR for ECC remain unknown.

OBJECTIVE

To investigate clinical outcomes and factors related to resectability and curability in ECC cases treated with EMR.

DESIGN

Retrospective study.

SETTING

Tertiary-care academic medical center.

PATIENTS

This study involved all patients in whom EMR was performed for ECC at Severance Hospital between March 1997 and August 2007. A total of 236 cases of ECC occurring in 231 patients (66.2% men) were enrolled.

INTERVENTION

EMR. Curative surgical resection and lymph node dissection were used in cases that were incompletely cured by EMR.

MAIN OUTCOME MEASUREMENTS

Resectability, curability, and recurrence.

RESULTS

Complete cure was achieved for 162 lesions (68.6%). Of the remaining 74 cases (31.4%), 69 (29.2%) were incompletely cured, and the other 5 (2.1%) had an undetermined resection status and ultimately required supplementary surgical resection for curative treatment. Location on the right side of the colon, piecemeal resection, and submucosal carcinoma were independently associated with incomplete resection, whereas depressed tumor type was independently related to incomplete cure. Among the ECC cases completely cured by EMR and followed for more than a year (n = 118), local recurrence was observed in one case (0.8%) during the median follow-up period of 39.4 months (range 12.4-123.1 months).

LIMITATIONS

Single-center, retrospective study.

CONCLUSION

Our data show that EMR is feasible and could be an effective option for treatment of ECC if the technique is applied with the appropriate indications.

Endoscopic submucosal dissection with a flexible Maryland dissector: randomized comparison of mesna and saline solution for submucosal injection (with videos)

BACKGROUND

Endoscopic submucosal dissection (ESD) is increasingly used for en bloc removal of GI lesions. Current ESD techniques have limitations including long procedure times, technical difficulty, and complications.

OBJECTIVE

To compare mesna with saline solution for ESD.

DESIGN

Blinded, randomized, controlled, porcine study in live animals.

SETTING

Animal laboratory.

INTERVENTION

Twelve gastric lesions were marked by using electrocautery. After submucosal injection, a circumferential mucosal incision was created, and ESD was performed by using a flexible Maryland dissector. Half of the ESDs were performed with submucosal injection of mesna.

MAIN OUTCOME MEASUREMENTS

Primary outcome was the time to dissect the submucosal plane. Secondary outcomes were total ESD time, specimen size, and procedure related complications.

RESULTS

The average (± SD) time for dissecting the submucosal plane was 15 minutes (range 10-22 ± 4.8 min) in the group with submucosal mesna injection and 16 minutes (range 8-29 ± 8.3 min) in the control group (P = 1.0). Complete en bloc resection including all of the electrocautery markings was achieved in all cases. Injection of mesna did not provide any benefit over saline solution in terms of overall ESD time (24 ± 7.3 min vs 28 ± 11 min; P = .42). There were no perforations. Four hemorrhages requiring intervention were encountered during the procedures in the control group, compared with no bleeding in the mesna group (P = .09).

LIMITATIONS

Animal model, limited sample size.

CONCLUSION

Submucosal mesna injection did not affect procedure times but was associated with a trend toward a lower incidence of intraprocedural bleeding.

Confocal endomicroscopy for in vivo prediction of completeness after endoscopic mucosal resection

BACKGROUND

Endoscopic mucosal resection (EMR) is an alternative to surgery for removal of superficial gastric neoplastic lesions. Residual neoplastic tissue of the resection interface is difficult to detect by conventional endoscopy. The aim of this study is to assess the efficacy of confocal laser endomicroscopy (CLE) in predicting complete resection margins after EMR.

METHODS

EMR was performed by using cap-assisted or "inject and cut" resection technique. Two weeks after EMR, the circumferential margins of the defect were inspected by using CLE, and completeness of excision was predicted from the CLE image. Additional EMR was performed if necessary. In vivo CLE diagnosis was validated against final histopathology.

RESULTS

Twenty-seven lesions were removed by EMR in 27 patients. After excluding 3 patients for gastrectomy, a total of 24 patients underwent CLE assessment, of whom 9 with indefinite lateral margins underwent at least two consecutive CLE follow-ups. A total of 19 lesions were regarded as complete remission, and 5 lesions (21.7%) were incompletely excised according to final pathologic diagnosis. Accuracy of CLE in predicting incomplete resection for original lesions was 91.7%, with sensitivity and specificity of 100.0 and 89.5%, respectively. The residual lesions were treated by additional EMR guided by CLE. There was no recurrence on endoscopic biopsies at mean (range) follow-up of 8.3 (4-15) months.

CONCLUSIONS

Confocal laser endomicroscopy has high accuracy for prediction of remnant tissue after EMR, and may lead to significant improvements in clinical surveillance after endoscopic resection.

Endoscopic mucosal resection in the management of esophageal neoplasia: current status and future directions

Endoscopic mucosal resection has expanded the role of the gastroenterologist in the management of esophageal neoplasia from screening and diagnosis to staging and endoscopic treatment. Its rise to prominence is a reflection of the long-identified need to obtain histologic information regarding depth of invasion and neoplastic margins during therapy that previously could not be achieved with ablative techniques. The resultant improvement in diagnosis and staging has allowed for better selection of patients for endoscopic therapy who may be spared invasive surgery. The clinical indications, endoscopic techniques, outcomes, and complications in the management of esophageal neoplasia are reviewed. Training requirements to achieve proficiency in endoscopic mucosal resection as well as potential quality measures to assess competence also are proposed in this review.

Comparative performance of novel solutions for submucosal injection in porcine stomachs: An ex vivo study

BACKGROUND

Submucosal injection of normal saline (NS) is commonly used during endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) but is quickly absorbed. Sodium hyaluronate (SH) produces longer lasting mucosal elevation but is expensive.

AIMS

To evaluate the performance of novel solutions for submucosal injection in comparison with NS and SH.

METHODS

One ml of the following solutions was injected in the submucosa of fresh specimens of porcine stomachs: NaCl 0.9%, SH 0.4%, human albumin 25%, two artificial tears solutions, namely, hydroxypropyl methylcellulose (HPMC) 0.3%/dextran 70.1% and polyvinyl alcohol (PVA) 1.4%, hydroxyethyl starch (HES) 6% and polyethylene glycol (PEG) 50%. The time until the disappearance of the mucosal elevation was recorded in a blind manner.

RESULTS

The median duration of mucosal elevation was significantly longer with HPMC/dextran, PVA, HES, PEG and SH (29, 26, 38, 31.5, and 41.5min, respectively) compared with NS (12min) (p<0.05 for each comparison). There were no significant time differences between SH and HPMC/dextran, HES and PEG (p>0.05).

CONCLUSIONS

Novel viscous or hypertonic solutions for submucosal injection, perform better than normal saline and equally well as sodium hyaluronate in porcine stomachs in vitro.

Endoscopic mucosal resection for staging and therapy of adenocarcinoma of the esophagus, gastric cardia, and upper gastric third

Minamally invasive endoscopic resection techniques allow definitive histological staging for dysplasia and early cancer and in many cases curative treatment. In Barrett's esophagus with High Grade Dysplasia (HGD) or early mucosal cancer, endoscopic mucosal resection (EMR) should be considered both as diagnostic and therapeutic first line procedure, with the possibility to repeat the procedure in case of residual Barrett's dysplasia or mucosal cancer. In early cancer of the the submucosa, surgical resection should be discussed. Endoscopic submucosal dissection (ESD) is a useful therapeutic option for HGD or early cancer in the squamous epithelium of the esophagus or in the stomach when en bloc resection is needed in large lesions.

Preemptive surgery for premalignant foregut lesions

INTRODUCTION

Preemptive surgery is the prophylactic removal of an organ at high risk for malignant transformation or the resection of a precancerous or "early" malignant neoplasm in an individual with a hereditary predisposition to cancer. Recent advances in molecular diagnostic techniques have improved our understanding of the biologic behavior of these conditions. Predictive testing is an emerging field that attempts to assess the potential risk of cancer development in predisposed individuals. Despite substantial improvement in these forms of testing, all results are imperfect. This information often becomes an important tool that is used by healthcare providers to evaluate the risk-benefit ratio of various risk modifying strategies (i.e., intensive surveillance or preemptive surgery).

METHODS

A systematic literature review was performed using Medline and the bibliographies of all referenced publications to identify articles relating to preemptive surgery for premalignant foregut lesions.

RESULTS AND DISCUSSION

In this review, we outline the controversies surrounding predictive risk assessment, surveillance strategies, and preemptive surgery in the management of high-grade dysplasia (HGD) in Barrett's esophagus (BE), hereditary diffuse gastric cancer (HDGC), bile duct cysts, primary sclerosing cholangitis (PSC), and pancreatic cystic neoplasms. Resection of BE is supported by the progressive nature of the disease, the risk of occult carcinoma, and the lethality of esophageal cancer. Prophylactic total gastrectomy for HDGC appears reasonable in the absence of accurate screening tests but must be balanced by the impact of surgical complications and altered quality of life. Surgical resection of biliary cysts theoretically eliminates the exposed epithelium to decrease the lifetime risk of cholangiocarcinoma. Liver transplantation for PSC remains controversial given the scarcity of donor organs and inability to accurately identify high-risk individuals. Given the uncertain natural history of pancreatic cystic neoplasms, the merits of selective versus obligatory resection will continue to be debated.

CONCLUSIONS

Preemptive operations require optimal judgment and surgical precision to maximize function and enhance survival. Ultimately, balancing the risk of surgical intervention with less invasive interventions or observation must be individualized on a case-by-case basis.

Randomized controlled study of EMR versus endoscopic submucosal dissection with a water-jet hybrid-knife of esophageal lesions in a porcine model

BACKGROUND

Endoscopic submucosal dissection (ESD) seems to be more effective than EMR for curative resection of GI mucosal neoplasia. However, ESD is technically difficult, hazardous, and time consuming. New technologies may overcome these drawbacks.

OBJECTIVE

Our purpose was to compare a new simplified ESD technique with conventional EMR.

DESIGN

Prospective, randomized, and controlled trial in anesthetized pigs.

METHODS

A total of 25 esophageal areas with a diameter of 20 mm were marked with coagulation points in 6 pigs under general anesthesia. These lesions were then randomized to either EMR by use of the cap technique or ESD. Submucosal injection of saline solution was used for both methods. ESD was performed with a hybrid-knife (ESDH), which allows cutting and coagulation as well as a needleless, tissue-selective hydrodissection through an axial water-jet channel with a preselected pressure by using a high-pressure water-jet system (ErbeJet 2). Intraoperative bleedings were treated with hemostatic forceps.

MAIN OUTCOME MEASUREMENTS

A comparison of the rates of complete resection of the lesions, the number and the size of resected specimens, the complication rate, and the procedural duration.

RESULTS

Thirteen lesions were randomized to EMR and 12 to ESDH. ESDH achieved complete resection significantly more frequently than EMR (10/12 vs 6/13; P = .05). All ESDH resections were performed as a single piece, whereas a mean (SD) of 2.5 +/- 0.9 resections were needed for EMR (P < .05). The mean (SD) areas of the specimen were 3.63 +/- 1.20 cm(2) in the ESDH group and 1.83 +/- 0.78 cm(2) in the EMR group (P < .0001). ESDH was performed with a larger amount of fluid for injection and hydrodissection compared with EMR (78.1 +/- 32.8 mL vs 20.9 +/- 7.6 mL; P < .001). The procedural duration was longer for ESDH than for EMR (28.2 +/- 11.9 minutes vs 12.2 +/- 4.9 minutes; P < .001). ESDH and EMR caused bleedings in 6 of 12 and 5 of 13 of the cases (P = .09), respectively. Hemostasis could be achieved in all cases. There was no perforation in either group.

LIMITATIONS

Resection of artificial non-neoplastic lesions, small numbers, an animal trial.

CONCLUSIONS

ESDH achieves complete resection of esophageal lesions significantly more frequently with a fewer number of specimens than EMR. ESDH is more time consuming, but the procedural duration seems to be shorter than conventional ESD because there is no need for exchange of devices for injection and cutting. The easy use of water-jet-assisted repeated injections of fluids may explain why ESDH was as safe as EMRC.

Endoscopic submucosal dissection in the upper gastrointestinal tract: present and future view of Europe

In Western countries endoscopic mucosal resection (EMR) has been widely accepted for treatment of early Barrett;s neoplasia and flat or depressed colorectal adenomas. In contrast endoscopic submucosal dissection (ESD) is infrequently performed for several reasons. It seems to be difficult to overcome the learning curve of this difficult technique because of the low case volume of early gastric cancer. On the other hand ESD of esophageal or colorectal lesions is even more challenging and is considered to be inappropriate for learning. In addition the indication for esophageal or colorectal ESD is controversial in view of excellent results of the well established EMR technique which is less time-consuming and safer than ESD. A recent survey of leading Western endoscopy centers indicated the limited experience with ESD with a low number of cases for all potential indications. Only a few training courses have been established and the number of ongoing clinical studies is limited. Only 12 out of 340 published articles on "endoscopic mucosal dissection" were reported from Western countries. A better acceptance of ESD requires improvement of the technique to allow an easier, faster and safer approach. There is a strong demand for structured training courses and limitations of human cases to selected centers which participate in prospective trials. A close collaboration between Western and Asian centers is recommended for improvement of the ESD technique and its clinical application.

Endoscopic mucosal resection of colonic lesions: current applications and future prospects

The introduction of submucosal fluid injection has remarkably extended the range of endoscopically resectable polyps. The limiting factor for endoscopic resection is not polyp size, but polyp depth. Endoscopic ultrasound is a useful adjunctive diagnostic tool to assess the depth of invasion. The success of are section ultimately depends on pathologic confirmation of a benign nature of this lesion or of a cancer limited to the mucosa. Selected well-differentiated cancers without lymphovascular invasion of the superficial submucosa can be successfully resected endoscopically.