Introduction to Endoscopic Submucosal Surgery

Strategies for Resection of Esophageal and Gastroesophageal Junction Submucosal Tumors

Background: Submucosal tumors (SMT) of the esophagus and gastroesophageal junction (GEJ) are rare entities, which often present a significant challenge to surgeons. Prior studies have reported only single-modality approaches. We report our experience with SMTs using multiple surgical techniques with the intent of margin-negative resection and organ preservation. Methods: Between 2001 and 2022, a total of 55 patients underwent surgical resection for SMT of the esophagus or GEJ at our institution. We reviewed the electronic medical records to obtain demographic information and details of the operation. We also report peri- and early (<30 days) postoperative outcomes. Results: Median age at operation was 62 years (22-93), and 54.5% were male. Endoscopic ultrasound was used in 45 (81.8%) patients preoperatively to classify tumors as possibly amenable for enucleation versus requiring mucosal resection. Forty-eight (87.3%) patients underwent minimally invasive procedures. Enucleation was performed in 23 (41.8%) patients, whereas 32 (58.2%) required full-thickness resection (wedge: 18; segmental: 11) or tumor resection with mucosectomy. One patient experienced Clavien-Dindo grade III or greater complications. There were no reoperations or postoperative mortality. Pathology revealed gastrointestinal stromal tumor in 25 (45.5%) patients, leiomyoma in 22 (40%), and other histology in 8 (14.5%). Negative surgical margins were achieved in 100% of the cases. Involvement of the cardia was associated with the need for full-thickness or tumor resection with mucosectomy (68.4% versus 31.5%, P = .0214). Surveillance was conducted in 20 (36.4%) patients with a median follow-up of 656 days (210-3091). One patient had progressive multifocal disease, and another went on to develop metastatic disease. Conclusion: Minimally invasive approaches are appropriate in most esophageal and GEJ SMTs and are associated with low complication rates and disease recurrence. Involvement of the gastric cardia increases the likelihood of requiring full-thickness resection or tumor resection with mucosectomy rather than enucleation.

Design and validation of performance-oriented injectable chitosan thermosensitive hydrogels for endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is a challenging procedure. The use of biomaterials to improve the operator's convenience (operating affinity) has received little attention. We prepared two thermosensitive hydrogels, lactobionic acid-modified chitosan/chitosan/β-glycerophosphate thermosensitive hydrogel (hydrogel 1) and its lyophilized powders (hydrogel 2), characterized their physicochemical properties and evaluated their performance in ESD experiments on large animals, by comparing with the commonly used normal saline (NS) and glycerin fructose (GF). These hydrogels showed good low-temperature fluidity; their viscosities at 4 °C were 92.2 mPa.s and 26.9 mPa.s, respectively. The hydrogels provided significantly better viscoelastic properties than NS and GF. The relaxation moduli of hydrogels were higher than those of NS and GF when the strains were 1 %, 5 %, and 10 %. The hydrogels can be maintained for seven days, even at pH 1, after which they degrade entirely. In pig model experiments, we performed submucosal injection and ESD procedures in the stomach and esophagus. The cushion height produced by the hydrogels was higher than those of NS and GF 30 min after injection. The ESD operation time for hydrogels was significantly shorter. Postoperative wound observation and histological analysis showed that the hydrogels promoted wound healing. The two hydrogels differed in fluidity, viscoelasticity, and other properties, which makes it possible to select the hydrogels according to the size and location of the lesion during ESD operation, and hydrogel 2 may be more suitable for use in lengthier procedures. In general, the hydrogels showed good performance, facilitated the intraoperative operation of ESD, shorten the operation time and promoted wound healing, which is of great significance for reducing the complications and reducing the threshold of ESD operation and further promoting the popularity of ESD.

Comparison of peroral endoscopic myotomy between de-novo achalasia and achalasia with prior treatment

Peroral endoscopic myotomy has been recognized as an effective treatment for patients with achalasia. Prior treatment may affect the outcome of subsequent treatment. We aimed to compare the safety and efficacy of POEM in treatment-naive patients vs. those with prior treatment failure. We retrospectively analyzed the data of achalasia patients who underwent POEM from November 2011 to January 2018. A comparative analysis was performed between De-Novo (DN) and Prior Treatment Failure (PTF) cases. Technical and clinical success, adverse events, operative time for POEM, hospital stay were compared between the two groups Overall, 209 patients with achalasia underwent POEM during the studied period, including 113 patients (54%) in the DN group and 96 patients (45%) in the PTF group. The baseline characteristics of the DN and PTF groups were not significantly different except for duration of disease. The PTF group had longer disease duration than the DN group. (7.92 ± 9.28 vs 4.45 ± 5.67 years, respectively, p = 0.005). Both groups were technically successful. Operative time was longer in the PTF group than that in the de-novo group, but the difference was not significant. The occurrence rates of complications were similar in both groups. Changes in the Eckardt score were comparable in the DN and PTF cases. IRP and LES pressure decreased after POEM. After 6 months, more patients suffered from reflux symptoms in the PTF group, but DeMeester score and endoscopic evaluation were not significantly different POEM is safe and equally effective for patients with prior treatment failure as well as de-novo patients up to 6 months post treatment.