Endoscopic submucosal dissection for superficial esophageal neoplasms

Experimental study of magnetic hydrogel assisted magnetic anchorguided endoscopic submucosal dissection in colonic tumors

BACKGROUND

Endoscopic submucosal dissection (ESD) is a well-established treatment for gastrointestinal tumors and enables en bloc resection. Adequate counter traction with good visualization is important for safe and effective dissection.

OBJECTIVE

Based on magnetic anchor-guided endoscopic submucosal dissection (MAG-ESD), we would like to explore the feasibility of magnetic hydrogel as an internal magnetic anchor that can be injected into the submucosa through an endoscopic needle to assist colonic endoscopic submucosal dissection.

METHODS

This prospective trial was conducted on 20 porcine colons ex vivo. We injected magnetic hydrogel into submucosa of the porcine colons ex vivo for MAG-ESD to evaluate the traction effect and operation satisfaction.

RESULTS

Magnetic hydrogel assisted ESD was successfully performed on 20 porcine colons ex vivo. Adequate counter traction with good visualization was successfully obtained during the procedure of dissection.

CONCLUSION

Magnetic hydrogel assisted MAG-ESD is feasible and effective.

Repeated steroid injection and polyglycolic acid shielding for prevention of refractory esophageal stricture

BACKGROUND

Postoperative stricture and refractory stricture are severe adverse events which occur after expansive esophageal endoscopic submucosal dissection (ESD). The aim of this study was to assess the efficacy of steroid injection, polyglycolic acid (PGA) shielding, and of additional steroid injection thereafter for the prevention of refractory esophageal stricture.

METHODS

This is a retrospective cohort study of 816 consecutive cases of esophageal ESD performed between 2002 and 2021 at the University of Tokyo Hospital. After 2013, all patients with a diagnosis of superficial esophageal carcinoma covering over 1/2 the esophageal circumference underwent preventive treatment immediately after ESD with either "PGA shielding", "steroid injection", or "steroid injection + PGA shielding". Additional steroid injection was performed for high-risk patients after 2019.

RESULTS

The risk of refractory stricture was especially high in the cervical esophagus (OR 24.77, p = 0.002) and after total circumferential resection (OR 894.04, p < 0.001). "Steroid injection + PGA shielding" was the only method significantly effective in preventing stricture occurrence (OR 0.36; 95% CI 0.15-0.83, p = 0.012). This method also decreased the risk of refractory stricture (OR 0.38; 95% CI 0.10-1.28, p = 0.096), but additional steroid injection was the only significantly effective method for prevention of refractory stricture (OR 0.42; 95% CI 0.14-0.98, p = 0.029).

CONCLUSION

Combining steroid injection and PGA shielding is effective for preventing post-ESD stricture and refractory stricture. Additional steroid injection is a viable option for patients at high-risk for refractory stricture.

Red dichromatic imaging reduces bleeding and hematoma during submucosal injection in esophageal endoscopic submucosal dissection

BACKGROUND

Bleeding and hematoma formation during submucosal injection in esophageal endoscopic submucosal dissection (ESD) reduce the visibility of the submucosa. Red dichromatic imaging (RDI) is an endoscopic technique that provides better visualization of the deep submucosal blood vessels. We speculated that blood vessel injury could be avoided with RDI. This pilot study evaluated the role of RDI in preventing bleeding and hematoma formation during esophageal ESD.

METHODS

This was a single-center retrospective observational study. We examined 60 patients who underwent ESD with white light imaging (WLI) and RDI. A single endoscopist reviewed all of the surgical videos to document the incidence and severity of bleeding episodes. Eighteen videos provided adequate quality and detail, and the number of blood vessels traversing the mucosal incision lines of the lesions in these videos was evaluated under WLI and RDI.

RESULTS

The WLI group had a significantly higher incidence of hematomas per unit area compared to the RDI group (0.18/cm² [range 0-0.38] vs. 0 [0-0.18]/cm², p = 0.024). The WLI group also had a significantly higher incidence of total bleeding episodes compared to the RDI group (42.9% [range 21.7-60.4] vs 16.7% [range 13.8-22.9], p < 0.001). Significantly more blood vessels were visible under RDI compared to WLI (5 [range 4-8] vs. 2 [range 1-5], p = 0.0020).

CONCLUSION

RDI reduced the incidence of bleeding and hematoma formation during submucosal injection in esophageal ESD. It was assumed that the improvement of blood vessel visibility by RDI might have contributed to the result.

Factors of technical difficulty in conventional and traction-assisted esophageal endoscopic submucosal dissection

BACKGROUND

The traction assisted (TA) method has reduced the technical difficulty associated with esophageal endoscopic submucosal dissection (ESD). However, it is unclear which factors associated with difficulty have been improved by the TA-ESD method. We aimed to evaluate and compare difficulty factors between conventional and TA-ESD.

METHODS

We retrospectively enrolled patients treated by ESD from Apr 2010 to Jun 2014 for the conventional ESD cohort and from Jan 2016 to Dec 2019 for the TA-ESD cohort. Difficult cases were defined as; (1)  ≥ 120 min ESD procedure time, (2) intraoperative perforation, or (3) piecemeal resection. We explored and compared the factors associated with technical difficulty in each cohort.

RESULTS

The conventional and TA-ESD cohorts included 285 (299 lesions) and 387 (421 lesions) patients, respectively. For difficult cases, the conventional and TA-ESD cohorts had 91 (30%) and 71 (17%) lesions, respectively. Multivariate logistic regression showed that ≥ 30 mm lesion length (odds ratio (OR) 6.85, 95% confidence interval (CI) 3.47-13.50), lower esophagus (OR 2.37, 95% Cl 1.34-4.21), > 1/2 circumference (OR 2.26, 95% CI 1.28-3.99), and left wall (OR 2.72, 95% CI 1.42-5.20) in the conventional ESD cohort, and ≥ 30 mm lesion length (21.30, 95% CI 4.75-95.30), lower esophagus (OR 3.05, 95% CI 1.52-6.13), and > 1/2 circumference (OR 6.40, 95% CI 3.06-13.40) in the TA-ESD cohort, were independently associated with technical difficulty.

CONCLUSIONS

TA-ESD can reduce the difficulty in cases including lesions in the left wall; however, cases in the lower esophagus and large lesions were still difficult to simplify.

Steroid injection and polyglycolic acid shielding to prevent stricture after esophageal endoscopic submucosal dissection: a retrospective comparative analysis (with video)

BACKGROUND AND AIMS

Postoperative stricture after expansive esophageal endoscopic submucosal dissection (ESD) is a severe adverse event. Previous single-arm reports have suggested that polyglycolic acid (PGA) shielding may prevent stricture. This study was performed to assess the efficacy of this method through a comparative analysis.

METHODS

This is a retrospective analysis of 500 consecutive cases of esophageal ESD performed between 2002 and 2018 at the University of Tokyo Hospital. After 2013, patients with a diagnosis of superficial esophageal carcinoma covering more than half of the esophageal circumference underwent preventive treatment with either PGA shielding or steroid injection + PGA shielding after ESD. The efficacy of these methods for preventing post-ESD stricture was assessed through multivariable logistic regression analysis.

RESULTS

The risk of postoperative stricture was especially high in the cervical esophagus (odds ratio [OR], 4.60; 95% confidence interval [CI], 0.65-61.09) and after total circumferential resection (OR, 3.58×103; lower bound of 95% CI, >185). Steroid injection + PGA shielding was the only method significantly effective in preventing stricture (OR, 0.30; 95% CI, 0.10-0.78; P = .009). In the relatively low-risk subgroup (excluding cervical esophageal cancer and complete circumferential resection), the postoperative stricture rates for steroid injection + PGA shielding versus PGA shielding versus control were 18.9% versus 41.4% versus 51.7%, respectively (P = .015). However, the efficacy of this was limited in extremely high-risk cases.

CONCLUSION

The combination of steroid injection and PGA shielding is effective for preventing post-ESD stricture. There is a need for even more effective methods for cervical esophageal cancer and complete circumferential resection.

Long-Term Outcomes of Endoscopic Submucosal Dissection for Superficial Esophageal Squamous Cell Carcinoma

In this review, we summarize up-to-date reports with 5-year survival after endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell carcinoma. In ESD for the depth of the epithelium (m1) or lamina propria (m2), the 5-year cause-specific survival and 5-year overall survival rates were reported to be 98-100%, and 85-95%, respectively. In cases with submucosal invasion or vascular involvement, additional prophylactic treatment such as chemoradiotherapy or surgery was recommended, and the 5-year cause-specific survival and 5-year overall survival rates were reported to be 85-100%, and 56-84%, respectively. Additional treatment might be too invasive for the elderly or patients with severe comorbidities. The risk of additional therapy should be balanced against the risk of lymph node metastasis, considering the life expectancy of such patients.

Hybrid Argon Plasma Coagulation for Treatment of Gastric Intestinal Metaplasia

Hybrid argon plasma coagulation (HybridAPC® [HAPC]) is an evolution of the standard argon plasma coagulation (APC) technology, where the application of APC is preceded by high-pressure needleless submucosal injection. APC is indicated for the ablation of benign and dysplastic mucosal lesions, such as vascular malformations or Barrett's mucosa. HAPC offers safety and efficacy advantages over standard APC because the submucosal injection acts as a heat sink that disperses energy. This ensures that the underlying muscularis propria remains unaffected, and only the mucosal layer is coagulated in its entirety. An 81-year-old Hispanic male was found to have a 1.2-cm mucosal nodule along the incisura of the stomach. Pathology of the biopsy specimen revealed high-grade dysplasia, and he subsequently underwent endoscopic ultrasound examination, which confirmed the presence of an isolated gastric nodule with no deep invasion of the muscularis propria, consistent with a uT1N0Mx endosonographic staging. He then underwent endoscopic submucosal dissection of the lesion. Pathology of the excised specimen confirmed the presence of multifocal high-grade dysplasia, arising in the background of extensive intestinal metaplasia. The deep margin was clear; however, the lateral resection margins showed focal involvement of intestinal metaplasia with low-grade dysplasia. Surveillance endoscopy confirmed the persistence of diffuse intestinal metaplasia. He was then treated with widespread HAPC due to the presence of underlying diffuse intestinal metaplasia in the stomach. HAPC is an effective and efficient treatment modality for mucosal lesions. In one series of 50 patients, 96% achieved complete macroscopic remission of Barrett's mucosa after a median of 3.5 APC sessions, and 85% achieved complete histological remission. HAPC is a promising therapeutic modality as a thermal injury is targeted, and the depth of injury is contained. This provides immediate procedural efficacy and safety benefits, and reduces subsequent complications when compared with standard APC. We anticipate that the applications of HAPC will continue to grow, as this modality is adopted into common procedural parlance. This case appears to be the first to describe the use of HAPC for definitive treatment of diffuse intestinal metaplasia.

Discrepancy Between the Clinical and Final Pathological Findings of Lymph Node Metastasis in Superficial Esophageal Cancer

BACKGROUND

Recent advances in endoscopic examinations have resulted in the detection of a larger number of early esophageal cancers; however, there have been many cases with clinically negative but pathologically positive lymph node metastasis (LNM). In this study, we aimed to evaluate the discrepancy between the clinical and pathological diagnoses of LNM in patients with cT1a-MM/cT1b N0M0 esophageal cancer, and assess LNM size in these patients to clarify the presence of LNM that cannot be detected with current modalities.

METHODS

This study included 50 patients who underwent surgery for cT1a-MM/cT1b N0M0 thoracic esophageal squamous cell carcinoma between January 2012 and November 2016 at our institution. The maximum size of involved LNs and metastatic nests were measured, and the distribution of LNM was investigated.

RESULTS

Of the 50 patients, 13 (26%) had LNM on pathological examination. Lymphatic invasion was significantly more frequent in the LNM-positive group than in the LNM-negative group (p = 0.005). The median sizes of 28 involved LNs and metastatic nests were 3 and 1.6 mm, respectively. Of these LNs, 20 (71%) were classified as micrometastases (≤ 2 mm). The involved nodes were distributed across three fields.

CONCLUSIONS

There was a discrepancy between the clinical and final pathological findings of LNM in patients with cT1a-MM/cT1b N0M0 esophageal cancer. The detection of involved nodes with current modalities in these patients was difficult because of the small size of LNM. Therefore, continued strong consideration for extended LN dissection is necessary in these patients to ensure appropriate diagnosis and treatment.

Outcomes of endoscopic submucosal dissection in esophageal adenocarcinoma staged T1bN0 by endoscopic ultrasound in non-surgical patients

Patients with esophageal adenocarcinoma (EAC) invading submucosa (T1b) are traditionally treated with esophagectomy and with chemoradiotherapy in poor surgical patients. Endoscopic submucosal dissection (ESD) has emerged as an alternative treatment in these patients. In this case series, we analyzed the outcomes of ESD in EAC staged T1bN0 by endoscopic ultrasound (EUS). Patients with EAC staged T1bN0M0 by EUS and PET scan who underwent ESD by a single operator (MS) between 2014 and 2017 at our institution were included. They were deemed as poor surgical candidates and ESD was considered as the most appropriate treatment option after a multi-disciplinary evaluation. There were 8 patients (male =5; female =3) with average age of 70.5 years old (range, 53-84 years old). ESD was completed in 7 and aborted in 1 patient due to tumor invasion into muscularis propria. En bloc, R0 and curative resection rates were 86% (6/7), 86% (6/7) and 71% (5/7) respectively. Final histology was intramucosal (T1a) in 4 and submucosal (T1b) in 3. One patient (14%) developed stricture requiring balloon dilation. Mean follow-up duration was 10 months (range, 3-15 months) and 71% (5/7) remain in clinical remission. Two patients required CRT, one with T1a who developed recurrence and another with T1b with lymphovascular invasion. In poor surgical candidates, ESD was associated with accurate staging and favorable outcomes in EAC staged T1bN0 by EUS. We suggest considering ESD in EAC staged T1bN0 for accurate histological staging, curative potential and also to help determine further course of treatment.

Inadequate steroid injection after esophageal ESD might cause mural necrosis

Background and study aims  Locoregional triamcinolone acetonide (TAC) injection is increasingly used for prevention of stricture after extensive endoscopic submucosal dissection (ESD) for superficial esophageal neoplasia. However, the safety of intramural TAC injection has not been elucidated. The aim of this study was to assess the clinical courses and histopathological changes after TAC injection into the muscle layer in a porcine model. Methods  Three pigs were subjected to ESD under general anesthesia. Two artificial 30-mm lesions were created at the oral and anal ends of the esophagus in each pig. TAC was injected into the muscle layer of the artificial oral ulcers (TAC group) and saline was injected into the muscle layer of the artificial anal ulcers (control group). Endoscopic, macroscopic, and histopathological evaluations were performed. Results  The artificial ulcers remained open at sacrifice on day 28 post-ESD in the three ulcers injected with TAC. Esophageal wall perforation and abscess spreading to the mediastinum were observed in two of the three ulcers in the TAC group. The abscesses involved the lungs, bronchi, and aortic adventitia. Severe inflammatory cell infiltration in the muscularis propria layer and significant muscularis propria degradation were observed in all three ulcers in the TAC group. Conclusions  This study suggests that TAC may cause deep mural damage when it is injected into the muscularis propria. Care should be taken not to inject TAC into the muscle layer when it is used to prevent post-ESD stricture formation.

Role of endoscopic therapy in early esophageal cancer

Esophageal carcinoma is a highly lethal cancer associated with high morbidity and mortality. Esophageal squamous cell carcinoma and esophageal adenocarcinoma are the two distinct histological types. There has been significant progress in endoscopic diagnosis and treatment of early stages of cancer using resection and ablation techniques, as shown in several trials in the recent past. Earlier detection of esophageal cancer and advances in treatment modalities have lead to improvement in the 5-year survival from 5% to about 20% in the past decade. Endoscopic eradication therapy is the preferred modality of treatment in cancer limited to mucosal layer of the esophagus as there is very low risk of lymph node metastasis, leading to high cure rates, low risk of recurrence and with few adverse effects. The most common adverse events seen are strictures, bleeding and rarely perforation which can be endoscopically managed. In patients with recurrent advanced disease or invasive tumor, esophagectomy with lymph node dissection remains the mainstay of treatment. There is debate on post-endoscopic surveillance with some studies suggesting closer follow up with upper endoscopy every 6 mo for the first 1-2 years and then annually for the 3 years while others recommending the appropriate action only if symptoms or other abnormalities develop. Overall, the field of endoscopic therapy is still evolving and focus should be placed on careful patient selection using a multidisciplinary approach.

Quality in upper gastrointestinal endoscopic submucosal dissection

Progress in the endoscopy technology field led to an increase in the diagnosis of early gastrointestinal (GI) superficial lesions and to an improvement of their treatment. Endoscopic submucosal dissection (ESD) has been developed in Japan with the aim of removing such lesions in one piece, in order to obtain a curative resection and to minimize the risk of local recurrence, and to preserve the native organ. ESD is widely used in Asia for the treatment of early upper and lower GI lesions and is currently gaining attention in Western countries too. However, ESD can be safely performed only by expert endoscopists and in specific clinical settings. Therefore, prior to decide whether ESD is feasible or not, the target lesion must be carefully assessed, in order to understand whether or not it is eligible for submucosal dissection. The aim of this paper is to review indications, limitations and technical aspects of upper GI ESD.

Evaluation of endoscopic submucosal dissection using a new endosurgical knife DN-D2718B: a first clinical feasibility study

BACKGROUND AND STUDY AIMS

Endosurgical devices with injection function have been reported to decrease endoscopic submucosal dissection (ESD) operation times for experts, but the efficacy of these devices for inexperienced endoscopists is unclear. The aim of this study was to evaluate the feasibility of ESD using a novel ESD knife (DN-D2718B).

PATIENTS AND METHODS

This is a single-center prospective pilot clinical feasibility study. Patients diagnosed with superficial gastrointestinal neoplasms were enrolled. A pre-specified group of ESD trainees with ESD experience on a porcine gastric model and fewer than 30 cases of ESD in their selected fields performed ESD under expert supervision, using the DN-D2718B. En bloc resection rates, R0 resection rates, procedure times, and incidence of intra-operational/post-operational adverse events were assessed.

RESULTS

Between June 2015 and January 2016, 13 esophageal, 27 gastric, and 14 colorectal ESD cases were performed per-protocol with mean resection speeds of 10.2, 12.0, and 15.5 mm 2 /min, respectively. There were no intra-operational complications.

CONCLUSION

ESD with this novel knife is feasible even when performed by non-experts.

Magnetic anchor guidance for endoscopic submucosal dissection and other endoscopic procedures

Endoscopic submucosal dissection (ESD) is a well-established, minimally invasive treatment for superficial neoplasms of the gastrointestinal tract. The universal adoption of ESD has been limited by its slow learning curve, long procedure times, and high risk of complications. One technical challenge is the lack of a second hand that can provide traction, as in conventional surgery. Reliable tissue retraction that exposes the submucosal plane of dissection would allow for safer and more efficient dissection. Magnetic anchor guided endoscopic submucosal dissection (MAG-ESD) has potential benefits compared to other current traction methods. MAG-ESD offers dynamic tissue retraction independent of the endoscope mimicking a surgeon's "second hand". Two types of magnets can be used: electromagnets and permanent magnets. In this article we review the MAG-ESD technology, published work and studies of magnets in ESD. We also review the use of magnetic anchor guidance systems in natural orifice transluminal endoscopic surgery and the idea of magnetic non-contact retraction using surface ferromagentization. We discuss the current limitations, the future potential of MAG-ESD and the developments needed for adoption of this technology.

Endoscopic submucosal dissection and endoscopic mucosal resection for early stage esophageal cancer

Mortality from esophageal cancer remains high despite advances in medical therapy. Although the incidence of squamous cell carcinoma of the esophagus remains unchanged, the incidence of the esophageal adenocarcinoma has increased over time. Gastroesophageal reflux disease (GERD and obesity are contributing factors to the development of Barrett's esophagus and subsequent development of adenocarcinoma. Early recognition of the disease can lead to resection of esophageal cancer prior to the development of lymphovascular invasion. Various modalities have been implemented to aid identification of precancerous lesions and early esophageal cancer. Chromoendoscopy, narrowband imaging and endoscopic ultrasound examination are typically used for evaluating early esophageal lesions. Recently, confocal laser endomicroscopy (CLE) and volumetric laser scanning were implemented with promising results. Endoscopic management of early esophageal cancer may be done using endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). Both techniques allow resection of the mucosa (and possibly a portion of the submucosa) containing the early tumor without interruption of deeper layers. A submucosal injection creating a cushion coupled with snare resection or cap assisted mucosal suction followed by ligation and snare resection are the most common techniques of EMR. EMR can remove lesions less than 2 cm in size en bloc. Larger lesions may require resection in piecemeal fashion. This may limit assessment of the margins of the lesion and orienting the lesion's border. ESD offers en bloc dissection of the lesion regardless of its size. ESD is performed with specialized needle knives, which allow incision followed by careful dissection of the lesion within the submucosal layer. Tumor recurrence after ESD is rare but the technique is labor intensive and has an increased risk of perforation. Esophageal stenosis remains a concern after extensive EMR or ESD. Dilation with balloon or stent placement is usually sufficient to treat post-resection stenosis.

Risk factors for intraoperative perforation during endoscopic submucosal dissection of superficial esophageal squamous cell carcinoma

AIM

To identify the risk factors and clarify the subsequent clinical courses.

METHODS

This study retrospectively analyzed consecutive patients with esophageal squamous cell carcinoma (ESCC) treated using endoscopic submucosal dissection (ESD) between April 2008 and October 2012. We divided the ESCC lesions into perforation cases and non-perforation cases, and compared characteristics and endoscopic findings between the two groups. "Intraoperative perforation" was defined as the detection of a perforation site during ESD and the presence of mediastinal emphysema.

RESULTS

In total, 147 patients with 156 ESCC lesions were treated by ESD. Intraoperative perforation was recorded for nine lesions (5.8%) from nine patients. Multivariate analysis identified mucosal deficiency larger than 75% of the circumference of the esophagus as an independent risk factor for intraoperative perforation (OR = 7.37, 95%CI: 1.45-37.4, P = 0.016). The predominant site of perforation was the left wall [6/9 (67%)]. Six of nine perforation sites were successfully closed by clips during the procedures. Two of nine cases required drainage for pleural effusions; however, all nine cases recovered with conservative treatment and without surgical intervention. At the median follow up of 42 mo after ESD, no cases of local recurrence or distant organ metastasis had been observed.

CONCLUSION

This study suggests that mucosal deficiency larger than 75% of the luminal circumference is a risk factor for intraoperative perforation during ESD for ESCC.

Esophageal Endoscopic Submucosal Dissection Assisted by an Overtube with a Traction Forceps: An Animal Study

Esophageal endoscopic submucosal dissection (ESD) is technically difficult. To make it safer, we developed a novel method using overtube with a traction forceps (OTF) for countertraction during submucosal dissection. We conducted an ex vivo animal study and compared the clinical outcomes between OTF-ESD and conventional method (C-ESD). A total of 32 esophageal ESD procedures were performed by four beginner and expert endoscopists. After circumferential mucosal incision for the target lesion, structured as the isolated pig esophagus 3 cm long, either C-ESD or OTF-ESD was randomly selected for submucosal dissection. All the ESD procedures were completed as en bloc resections, while perforation only occurred in a beginner's C-ESD procedure. The dissection time for OTF-ESD was significantly shorter than that for C-ESD for both the beginner and expert endoscopists (22.8 ± 8.3 min versus 7.8 ± 4.5 min, P < 0.001, and 11.3 ± 4.4 min versus 5.9 ± 2.5 min, P = 0.01, resp.). The frequency and volume of the submucosal injections were significantly smaller for OTF-ESD than for C-ESD (1.3 ± 0.6 times versus 2.9 ± 1.5 times, P < 0.001, and 5.3 ± 2.8 mL versus 15.6 ± 7.3 mL, P < 0.001, resp.). Histologically, muscular injury was more common among the C-ESD procedures (80% versus 13%, P = 0.009). Our results indicated that the OTF-ESD technique is useful for the safe and easy completion of esophageal ESD.

Endoscopic submucosal tunnel dissection for large superficial esophageal squamous cell neoplasms

Endoscopic submucosal dissection (ESD) is a well-established treatment for superficial esophageal squamous cell neoplasms (SESCNs) with no risk of lymphatic metastasis. However, for large SESCNs, especially when exceeding two-thirds of the esophageal circumference, conventional ESD is time-consuming and has an increased risk of adverse events. Based on the submucosal tunnel conception, endoscopic submucosal tunnel dissection (ESTD) was first introduced by us to remove large SESCNs, with excellent results. Studies from different centers also reported favorable results. Compared with conventional ESD, ESTD has a more rapid dissection speed and R0 resection rate. Currently in China, ESTD for large SESCNs is an important part of the digestive endoscopic tunnel technique, as is peroral endoscopic myotomy for achalasia and submucosal tunnel endoscopic resection for submucosal tumors of the muscularis propria. However, not all patients with SESCNs are candidates for ESTD, and postoperative esophageal strictures should also be taken into consideration, especially for lesions with a circumference greater than three-quarters. In this article, we describe our experience, review the literature of ESTD, and provide detailed information on indications, standard procedures, outcomes, and complications of ESTD.

Superficial Esophageal Neoplasms Overlying Leiomyomas Removed by Endoscopic Submucosal Dissection: Case Reports and Review of the Literature

The coexistence of an epithelial lesion and a subepithelial lesion is uncommon. In almost all such cases, the coexistence of these lesions appears to be incidental. It is also extremely rare to encounter a neoplasm in the surface epithelium that overlies a benign mesenchymal tumor in the esophagus. Several cases of a coexisting esophageal neoplasm overlying a leiomyoma that is treated endoscopically or surgically have been reported previously. Here, three cases of a superficial esophageal neoplasm that developed over an esophageal leiomyoma and was then successfully removed by endoscopic submucosal dissection are described.

Indications and Techniques for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) allows for curative resection of superficial neoplasms of the gastrointestinal tract. Although ESD is the standard of care in Japan, its adoption in the West has been slow. Recent studies have shown the advantages of ESD over endoscopic mucosal resection, and as many of the barriers to ESD have been overcome, we are seeing an increasing interest in this technique. ESD can be used to treat superficial gastric, esophageal, and colorectal lesions. The most important pre-procedure step is estimating the depth of invasion of a lesion and by proxy the risk of lymph node metastasis. After a lesion has been resected, the histopathological analysis will determine whether the resection was curative or whether further surgery is needed. In conclusion, ESD is being more widely used in the West, and it is important to understand the indications, limitations, and techniques of ESD.

Lymph Node Metastases in Esophageal Carcinoma: An Endoscopist's View

One of the most important prognostic factors in esophageal carcinoma is lymph node metastasis, and in particular, the number of affected lymph nodes, which influences long-term outcomes. The esophageal lymphatic system is connected longitudinally and transversally; thus, the pattern of lymph node metastases is very complex. Early esophageal cancer frequently exhibits skipped metastasis, and minimal surgery using sentinel node navigation cannot be performed. In Korea, most esophageal cancer cases are squamous cell carcinoma (SCC), although the incidence of adenocarcinoma has started to increase recently. Most previous reports have failed to differentiate between SCC and adenocarcinoma, despite the fact that the Union for International Cancer Control (7th edition) and American Joint Committee on Cancer staging systems both consider these separately because they differ in cause, biology, lymph node metastasis, and outcome. Endoscopic tumor resection is an effective and safe treatment for lesions with no associated lymph node metastasis. Esophageal mucosal cancer confined to the lamina propria is an absolute indication for endoscopic resection, and a lesion that has invaded the muscularis mucosae can be cured by local resection if invasion to the lymphatic system has not occurred.

Single center experience of endoscopic submucosal dissection (ESD) in early Barrett's adenocarcinoma

BACKGROUND

Endoscopic mucosal resection (EMR) or radical surgical resection are the standard treatment options for patients with early Barrett's adenocarcinoma (EBAC). Endoscopic submucosal dissection (ESD) is a new endoscopic technique, which allows--in contrast to EMR--endoscopic en-bloc resection of neoplastic lesions greater than 2 cm with complete histological evaluation of the resected specimen. In contrast to Western countries, Barrett's esophagus is less common in Asia indicating the low volume of published data of ESD in EBAC in Japanese series. Therefore, the aim of the present study is to describe the results of ESD in patients with EBAC performed in a German tertiary referral center.

METHODS

Between November 2009 and April 2014 ESDs were performed in 22 patients with histologically proven EBAC. Data were given for the en-bloc, the R0, the R0 en-bloc, and the curative resection rate as well as for the complication and the local recurrence rate.

RESULTS

ESD was technically possible in all of the 22 patients. 20 of the resected EBAC were mucosal carcinomas, whereas in two patients the tumor showed submucosal invasion. The en-bloc, R0, R0 en-bloc, and curative resection rates were 95.5, 81.8, 81.8 %, and 77.3 %, resp. Complication rate was 27.3 % (perforation n = 1, bleeding n = 2, stenosis n = 3). In case of curative tumor resection, only one local tumor recurrence (5.9 %) occurred after a medium follow-up of 1.6 years.

CONCLUSIONS

Despite the small number of patients and a relatively short follow-up, the present data underline the value of ESD, especially in case of curative resections in the definite and less invasive therapy of EBAC. Attention should be drawn toward subsquamous extension of EBAC requiring a sufficient safety margin as an obligate condition for curative R0 resections. Due to the required learning curve and the management of potential complications, ESD should be restricted to greater endoscopic centers.

Development of novel treatment with a bioabsorbable esophageal patch for benign esophageal stricture

Using a large animal model, we examined whether circumferential stricture after esophageal endoscopic submucosal dissection (ESD) can be treated by grafting a bioabsorbable esophageal patch. Circumferential ESD was performed on the thoracic esophagus in pigs (n = 6) to create a stricture, for which one of the following interventions was performed: (1) the stricture site was longitudinally incised, and an artificial esophageal wall (AEW) was grafted after placing a bioabsorbable stent (AEW patch group, n = 3); (2) endoscopic balloon dilation (EBD) was performed every other week after stricture development (EBD group, n = 3). In both groups, esophageal fluoroscopy was performed 8 weeks after the interventions, and the esophagus was excised for histological examination of the patched site. In the AEW patch group, esophageal fluoroscopy revealed favorable passage through the patched site. Histologically, the mucosal epithelium and lamina propria had regenerated as in the normal area. In the EBD group, the circumferential stricture site showed marked thickening, and there were hypertrophic scars associated with epithelial defects on the luminal surface. Histologically, defects of the mucosal epithelium and full-thickness proliferation of connective tissue were observed. AEW patch grafting was suggested to be a potentially novel treatment strategy for post-ESD esophageal circumferential stricture.

Endoluminal resection and tissue acquisition

Endoscopic resection as curative treatment is feasible and indicated for gastrointestinal adenomas and early cancer limited to the mucosal layer and submucosal layers, where the risk for nodal and distant metastases is minimal. The initial technique of endoscopic resection, endoscopic mucosal resection, was limited by the inability to have en bloc resections for lesions larger than 2 cm. This meant that proper assessment of resection margins and depths was not possible in these cases, with the risk of incomplete resection and remnant lesions. In the last decade, the technique of endoscopic submucosal dissection was introduced, and this has allowed en bloc resection of superficial cancers of the esophagus, stomach, and colon. Cumulative data have shown high en bloc resection rates and excellent short-term and long-term outcomes when treatment inclusion criteria are adhered to. Endoscopic resection techniques were recently applied in the context of submucosal lesions. In the case of lesions located in the muscularis mucosa and submucosal layers, the gastrointestinal wall is not breached during endoscopic resection. However, in the case of submucosal lesion located in the muscularis propria layer, endoscopic mucosal resection or endoscopic submucosal dissection would result in perforation which may not be easily closed endoscopically. The technique of endoscopic submucosal tunneling was introduced in the context of peroral endoscopic myotomy for the treatment of achalasia. The principle was extended to the resection of tumors arising from the muscularis propria layer, with promising results.

New progress in endoscopic treatment of esophageal diseases

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 the entire gastrointestinal tract. Many minimally invasive endoscopic therapies based on ESD have been developed recently. Endoscopic submucosal excavation, submucosal tunneling endoscopic resection and laparoscopic-endoscopic cooperative surgery have been used to remove submucosal tumors, especially tumors which originate from the muscularis propria of the digestive tract. Peroral endoscopic myotomy has recently been described as a scarless and less invasive surgical myotomy option for the treatment of achalasia. Patients benefit from minimally invasive endoscopic therapy. This article, in the highlight topic series, provides detailed information on the indications and treatments for esophageal diseases.

Preoperative iodine staining may complicate the demarcation of esophageal carcinoma

A 53-year-old man was suspected of having an esophageal neoplasm. An endoscopic examination including Lugol chromoendoscopy suggested an esophageal squamous cell neoplasm limited to the lamina propria. A targeted biopsy showed atypical squamous cells, and an endoscopic submucosal dissection was performed 22 days after the previous endoscopy. Although a single 40 mm unstained area was observed by preoperative Lugol chromoendoscopy, intraoperative endoscopy revealed a 25 mm iodine-unstained area, with small unstained areas scattered on the oral side. We included the small unstained areas in the extent of the resection through assessment by preoperative endoscopy. Histopathologically, the tumor extent appeared to coincide with the preoperative assessment. Tumor cells were found in the basal-parabasal layers of the mucosa, in which small unstained areas were scattered, although the superficial layers exhibited well-differentiated cells containing glycogen in the cytoplasm. Although Lugol chromoendoscopy, which can induce chemical esophagitis, is widely used, re-epithelialization after mucosal damage by preoperative iodine staining may complicate the intraoperative demarcation of tumors.

Management of complications associated with endoscopic submucosal dissection/ endoscopic mucosal resection for esophageal cancer

Endoscopic resection of early esophageal cancer (EEC) is an established therapy in Japan and is increasingly becoming accepted and used regularly in other countries. Endoscopic submucosal dissection (ESD), an application of conventional endoscopic mucosal resection (EMR), has been developed to allow the resection of larger lesions in an en bloc manner; the earliest results so far have been promising even in EEC. ESD allows precise assessment of the histopathological curability of resected specimens, reducing local recurrence. However, ESD has relatively high complication rates; notification of perforation risk is essential especially in the esophagus. Bleeding during ESD can be managed by endoscopic closure with endoclips, and delayed bleeding is rare. Esophageal stricture following semicircular or complete circular esophageal ESD was relatively frequent even when treated by multiple pre-emptive endoscopic balloon dilation. Endoscopic triamcinolone injection, temporal stenting and innovative transplantation of autologous tissue-engineered epithelial cell sheets have shown promising results for the prevention of luminal stricture following semicircular esophageal ESD. In cases of circumferential ESD, however, giving oral prednisolone can offer a unique treatment option for the prevention of intractable post-procedural stricture of the esophagus.

Current treatment options for the management of esophageal cancer

In recent years, esophageal cancer characteristics and management options have evolved significantly. There has been a sharp increase in the frequency of esophageal adenocarcinoma and a decline in the frequency of squamous cell carcinoma. A more comprehensive understanding of prognostic factors influencing outcome has also been developed. This has led to more management options for esophageal cancer at all stages than ever before. A multidisciplinary, team approach to management in a high volume center is the preferred approach. Each patient should be individually assessed based on type of cancer, local or regional involvement, and his or her own functional status to determine an appropriate treatment regimen. This review will discuss management of esophageal cancer relative to disease progression and patient functional status.