Endoscopic Resection For Submucosal Tumors Of The Esophagogastric Junction Originating From Muscularis Propria

BackgroundSubmucosal tumors (SMTs) are a big family of benign tumors located in submucosa of digestive tract, including leiomyoma, stromal tumor, lipoma and neurogenic tumors. Based on originations, they could be classified to tumors from muscularis mucosa, from submucosa and from muscularis propria layer. Generally, patients shows no specific clinical manifestations. Most of SMTs are displayed with non-specific extrinsic features, and are difficultly undergone biopsy, due to a layer of mucosa covered on the surface of tumors. Leiomyoma and gastrointestinal stromal tumors (GISTs) are the two primary members. Leiomyomas are generally benign tumors, located in esophagus. GISTs are mainly located in stomach. They are derived from stromal tissue of muscularis propria layer, with malignant potential.The risk of malignant potential is associated with the diameter of tumors. Previous data revealed tumors smaller than 3 cm are generally benign tumors.Endoscopic ultrasonography (EUS) is a new technology to scan digestive tract, using the ultrasound probe fixed on the top of the endoscope. EUS could judge the disease by the depth of tumor, diameter and characteristic of echo. EUS-guided fine needle aspiration (EUS-FNA) could provide a basic result of pathology. Leiomyoma and GIST are displayed with non-specific extrinsic features under EUS, unless canceration of stromal tumors. The final decision should be based upon the immunohistology. Currently around the world, SMTs, smaller than 2cm, should be observed intensively. While, SMTs larger than 2cm, should be resected surgically. Now, increasing number of SMTs could be resected by way of endoscopy because of the development of new technologies.Esophagogastric junction (EGJ) is the region connects esophagus and stomach, covering the terminal portion of esophagus and the beginning of stomach at the cardiac orifice. Generally, EGJ has the following four signs:(1) the lower esophagus lower grid shaped vascular using endoscopy; (2) His angle along the gastric wall extension line; (3) the greater curvature of the stomach folds longitudinal towards the end;(4) specimens of changes in circumference. EGJ is the portal to control the food entering the stomach cavity. The lower esophageal sphincter (LES) is the ring of muscle in the esophageal and gastric junction, around 1cm-2cm mild thickening. In the resting state, intraluminal pressure of LES is higher than in intragastric pressure, preventing reflux of the stomach contents and gastric acid. In swallowing, LES relaxes, allowing food entering into the stomach, and then LES contracts to recovery pressure. In addition, His angle also has the functions of preventing the reflux of stomach contents. Therefore, resection of EGJ will lead to food reflux symptoms.Tunnel endoscopy (TE) emerged with the invention of new equipments and the development of new technologies. TE carries on the procedures by way of a tunnel between the mucosa and muscularis propria layer. TE technology builds the submucosal tunnel with the natural layer of the digestive tract, ensuring the integrity of the digestive wall. The area of wound will be smaller, and the requirement of endoscopic suturing technique and occurrence of gastrointestinal fistula will also be reduced.EGJ was thought to be the forbidden region because of the special anatomy, the sharp angle and narrow cavity. Surgical gastric cardia resection used to be the standard for SMTs lesions. After cardia excision, the valve will be lost connecting the gastroesophageal junction, resulting in to severe reflux. Submucosal tunelling endoscopic resection (STER) is firstly applied by Chinese scholar Meidong Xu in 2010 in treating SMTs of esophageal muscularis propria. This technology is operated by utilizing the tunnel space between the mucosa and muscularis propria, which can completely resect the tumor, and can greatly reduce the incidence of digestive tract fistula. Based on the previous data, STER could treat SMTs of esophageal, gastric fundus, cardia, small bend, gastric antrum and rectum. However the study samples were relatively small.Professors of Hongwei Xu and Jiyong Liu from the department of internal medicine in our hospital, firstly performed POEM and STER since 2011. The summarized data showed a fewer complications and better effect using STER in treating SMTs of muscularis propria of EGJ.ObjectiveTo evaluate the efficacy and safety of STER techniques for treating SMTs of the EGJ originating from the MP layer.MethodsFrom October 2011 to October 2014,40 patients were enrolled for STER surgery.ResultsThe 40 patients were categorized into three groups by tumor locations:esophagocardiac (n=14), cardiac dentate (n=12), and gastrocardiac (n=14) groups. The average resected lesion size was 2.2±0.8cm. The mean operation time was 105±50min. The esophagocardiac group had a lower complication rate (0/14) compared with the cardiac dentate group (6/12) and the gastrocardiac group (6/14). The mean operation time in the esophagocardiac (83±24 min) and cardiac (83±55 min) groups was significantly shorter than that of the gastrocardiac group (145±44 min) (P<0.05). The en bloc resection rate was 100% with no severe complications and no recurrence in follow-up.ConclusionsThe STER technique appears to be a feasible and safe minimally invasive approach for SMTs originating from the MP layer of the EGJ, with satisfying en-bloc resection, short operation time, and low rates of complications.BackgroundSince 1980s, digestive endoscopy have been developed rapidly, especially in Japan. The Japanese eating habits caused the high incidence of stomach cancer. In 1984 the Japanese professor Tada firstly used endoscopic mucosal resection to treat early gastric cancer. Compared to traditional surgery, EMR could greatly improve the quality of patients’life, hence, it is widely used. On the other hand, it is difficult to resect the lesion of which diameter is more than 1.5cm. And larger lesions often need 2-3 times to resect, as the known Endoscopic Piecemeal Mucosal Resection. After the lesion is resected to fragments, it is difficult to restore and assess the original lesion staging assessment.And it is difficult to assess the exact pathology of the original lesions, either. Some researches also showed that graded resection was easier than one-time removal of the lesion, which often resulted into incomplete resection or disease recurrence. The predictor of prognosis is that the adenocarcinoma is differentiated or not, with or without lymph vascular invasion, and if there is residual lesions. These factors are required exactly pathology assessment to determine whether patients need additional surgery or not. In order to effectively treat early cancer, Japanese professor Takekoshi invented insulated-tip knife in 1994. And in 1999 the Japanese professor Gotoda firstly used IT Knife to resect the early gastric cancer completely. With the constant invention of new endoscopic instruments, this new technology was improved continuously, and then in 2003 this technology was named endoscopic submucosal dissection (ESD).Compared with EMR technology, ESD has no limits on the size of the lesion, and higher en bloc and complete resection rate, but with the higher perforation rate. ESD technology opened a new era of endoscopic therapy. Endoscopic submucosal resection(ESMR), endoscopic submucosal excavation(ESE), endoscopic full-thickness resection(EFR) are widely used in clinical. For most gastrointestinal SMTs, they can completely resect the lesion. Especially to the SMTs from muscularis mucosa, submucosa, ESMR treatment did not undermine the integrity of the muscularis propria of the digestive tract, and is safer with lower complication rate. For the SMTs from muscularis propria, especially for those invaded to the cavity and adhesioned serosa closely, it’s difficult to resect by ESMR or ESE, and it maybe need EFR. According to current endoscopic instruments and technical conditions, as long as there are spaces for maneuver and good location, most gastrointestinal perforation can be successfully patched. However, with smaller space and poorer intraluminal conditions, it’s difficult or impossible to be closed completely.For the SMTs from the inherent parts of EGJ, if the tumor is located in the cardia dentate line, it is preferred to the ESE. However, due to physiological cardiac stenosis and rich blood, endoscopic treatment maybe easily caused bleeding. And if the tumor is large and across the cardia dentate line or even extends to the stomach cavity, the conventional endoscopic therapy is difficult to completely resect. For the SMTs below cardia, due to limitations of endoscopic manipulation, it’s often used reverse endoscopy. Since 2006, the department of gastroenterology in our hospital has been carrying out ESD treatment, such as ESE, EFR, ESMR, STER technology in treating SMTs, and we have accumulated a great deal of clinical experiences.PurposeDirect endoscopic resection techniques (ESD, ESMR, ESE, EFR, etc.) and endoscopic submucosal tunnel after resection (STER) are widely used in the gastrointestinal mucosa tumors. Because the injuries of ESD, ESMR are large, and gastroesophageal junction is in a unique position, conventional wound closure technique is difficult to close once perforation. For the submucosal tumor originated from the muscularis propria of the EGJ site, the first two are not the first choice of treatment. While EFR need to do full-thickness excision, which is commonly used in treating lower submucosal tumors, ESE could not completely remove the lesion. This study aimed to evaluate the efficacy and safety of mucosal inner excavation technique (ESE) and submucosal tunneling endoscopic resection technique in treating the gastroesophageal junction tumors under the muscularis propria.MethodsWe collected the clinical and pathological data of patients during October 2011 to October 2014 who accepted STER and ESE in Provincial Hospital Affiliated to Shandong University. A total of 90 cases whose SMTs from the gastroesophageal junction intrinsic myometrium met the inclusion criteria.50 patients received ESE treatments, and 40 patients received STER treatment. The main outcome measures included hours of operation, complete resection rate, tumor recurrence rates and adverse events.Results40 patients who accepted STER according to tumor location were divided into three subgroups:esophagus-cardia group(14 cases), cardiac group(12 cases), cardia-gastric/upper stomach group(14cases). And 50 patients who accepted ESE were divided into three subgroups:esophagus-cardia group (6 cases), cardiac group (6 cases), cardia-gastric/upper stomach group (38 cases). Overall, the rate of complete resection of STER group was higher than that of ESE group (100% VS 92%), while the rate of delayed bleeding, postoperative pneumothorax, pneumoperitoneum of STER group were lower than that of ESE group. All cases didn’t have tumor recurrence, chronic fistula formation or secondary infection. The data shows that, STER group spends more operation time than ESE group (1104.90±49.59min VS 69.40±39.68min,P<0.05), in the cardia-fundus/upper stomach subgroups it’s more obvious; the morbidity of STER group is higher than ESE group. For larger SMTs (diameter > 1.5cm), the rate of complete resection of STER group is higher than that of ESE group (31/31 VS 14/18), In addition to the complications of other gas into the tissue space such as pneumothorax, subcutaneous emphysema, pneumoperitoneum, the complication rate of STER group is less than ESE group (6/31 VS 6/18).ConclusionsSTER and ESE in treating SMTs of gastroesophageal junction muscularis propria are safe and effective. ESE is used more widely, and STER spends longer time than ESE but having lower perforation rate. Its complications mainly include mediastinal emphysema, pneumothorax or pneumoperitoneum. For smaller lesions (diameter≤1.5cm) ESE treatment is the first choice because of shorter operating time. While for larger and irregular lesions (diameter>1.5cm), for safer operation and complete resection of the tumor, we preferred to the STER treatment.