Endoscopic Submucosal Dissection And Submucosal Tunneling Endoscopic Resection For Gastric Ectopic Pancreas

BackgroundEctopic pancreas, also called heterotopic or aberrant pancreas,is defined as pancreatic tissue lying outside its normal location and lacking anatomic or vascular connections with the pancreas. It is a congenital abnormality.It can manifest clinically in some rare diseases of the pancreas including pancreatic cyst,pancreatitis and carcinoma. Ectopic pancreas can lead to different complaints or complications as different part, intussusception as heterotopic pancrea in small intestine, thin and progressive jaundice from ectopic pancreatic cancer in ampulla, perforation or obstryuction in pancreas in colon, pyloric obstryuction and bleeding in pancreas in gastry were reported.A literature reported that about43.5%ectopic pancreas located at the stomach in domestic.Gastric ectopic pancreas is difficult to diagnose because lack of typical clinical symptoms, polytropic anatomical position,different sizes.Surgery and pathologic examination in operation were thinked to be the most important motheds before,but the surgery has risks and increase long-term complications.The characteristics of gastric ectopic pancreas are being know as the development of endoscope,it most located in gastric antrum and were showed hemispherical or umbilical form, different sizes and shapes, mucous membrane of the surface is normal,a few has congestion,edema and erosion,some has umbilical depression.Some scholars thinked that the umbilical depression has certain significance to the diagnosis, but there were another scholars reported it was not a specific change,thus gastric ectopic pancreas didn’t yet has specific performance except the submucosal lesion by common endoscopic,pathology still is the definitely method for diagnose.Endoscopic biopsy forceps for specimen pathological examination can help diagnose, but difficult to obtain the gastric ectopic pancreas as it is often located in the submucosa or deeper, so gastric ectopic pancreas preoperative diagnosis is still difficult at present.DL Magno and Green made Endoscopic ultrasonograpy (EUS) with endoscope and ultrasonic since1980, EUS is improved continuously. It combines the dual advantages of endoscope and the ultrasonic probe, to show the gastrointestinal structure and submucosal lesions clearly. Gastric ectopic pancreas can be originated in the second, third, fourth or multilayer layers of stomach wall, but the submucosa is most common. The characteristic EUS features including heterogeneous echogenicity,or low echo, equal echo, high echoor medium uneven echo, the clear or not clear boundary,a few has an anechoic area and fourth-layer thickening.48patients of early gastrointestinal tumor diagnosed with endoscopic received EUS examination before Endoscopic mucosal resection (EMR) were reported by Ohashi, the coincidence rate was100%. Dong Yup Ryu reported3in8patients with pathologically proven gastric ectopic pancreas were diagnosis with ultrasound (coincidence rate37.5%). Domestic Cheng Tianming, Guo Wen reported59patients were diagnosed with gastric ectopic pancreas by EUS,54cases were proved by pathology finally, the coincidence rate was91.5%.Shen yang, Wang Bangmao reported52patients were diagnosed with gastric ectopic pancreas by EUS,41were proved by pathology finally, the coincidence rate was78.9%. So that the diagnosis reliability of EUS is still uneven currently, so there has yet to be further research.There has not been determined about how to treat gastric ectopic pancreas.Many scholars advocate all should do surgery regardless of the presence of symptoms, other scholars tend to follow-up observation as patients life quality will be affected after operative and may increase the long-term complications. However, follow-up observations need gastroscope or endoscopic ultrasonography examination many times repeated,it increase the pressure in patients psychological and economic. With EUS and technology and equipment of endoscopic development, Endoscopic treatment has continuous improvement and innovation, such as high frequency electrocoagulation, Endoscopic mucosal resection (EMR), EMR with a ligation(EMRL),EMR with a cap(EMRC),piecemeal EMR(EPMR),Endoscopic submucosal dissection (ESD) as well as Submucosal tunneling endoscopic resection(STER) were could used to treat gastric ectopic pancreas. EMR has its limitations as hard for large lesions or mucosal fibrosis lesion, piece resection can cause not accurate histological diagnosis,thus the local recurrence rate will be high, and EMR is used for mucosa lesions but more tissue residual for submucosa,furthermore,repeated EMR can cause the submucous fibrosis to make treatment difficult, that increase the risk of perforation.ESD is a new technology for dissection early gastrointestinal tumors by special equipment on the basis of EMR,it dissects the submucosal layer directly. ESD expanded treatment indication range significantly, realized larger lesions and submucosa lesions dissection one-time, and provide complete pathological data to evaluation, so it can reduce the residue and recurrence effectively. Its efficacy equal with surgical, and has advantages like less trauma, faster recovery, and no change the gastrointestinal structure, lower medical costs.There had some papers about ESD treat ectopic pancreas at domestic and overseas,Dong Yup Ryu planned to use EMR for8gastric ectopic pancreas patients,4of these changed to receive ESD because negaitve lifting sign after submucosal injection,those lesions were successfully complete resection of no complication and no recurrence.Cheng Tianming used ESD for8gastric ectopic pancreas patients (including1had first EMR treatment), he also get complete resection of no perforation and other serious complications.As the development of Peroral endoscopic myotomy(POEM) and Submucosal tunnelling endoscopic resection (STER), the tunnel technology treat for gastric ectopic pancreas will be possible, but didn’t see the report.STER could separated mucosa and muscularis propria through the submucosa tunnel,to resect the lesions either in mucous side or muscularis propria side, clamps closed tunnel if lesion from the muscularis propria.Therefore,this research focuses on exploration using ESD and STER for diagnosis and treatment of gastric ectopic pancreas, in order to clear the characteristics of clinical and gastroscope and the image features with EUS of stomach ectopic pancreas, through the ESD complete resection to get pathology examination and reach the purpose of treatment, at the same time, explore the efficacy and safety of endoscopy resection through follow-up, so as to provide a new method for gastric ectopic pancreas.Objectives:To investigate the efficacy, safety, outcome of endoscopic submucosal dissection (ESD) and Submucosal tunnelling endoscopic resection (STER) for gastric ectopic pancreas.Patients and Methods:1. Patients We seleceted the patients suspected diagnosis of gastric ectopic pancreas as the finding of submucosal apophysis lesions by electronic gastroscopy examination and remand endoscopic resection in the Digestive endoscopy center of the Third Affiliated Hospital of Southern Medical University between December2010and March2013.A toal of40patients were included,26men and14women, ranged in age from15to72years(mean43.1years).Except for patients who with severe damage in cardiovascular,lung or brain, blood coagulation dysfunction not correct,refused endoscopic resection.Patients and relatives signed the informed consent.2. Methods2.1EUS examination:Compelte the relevant examinations before operation including EUS,sent the ultrasound gastroscope to lesions along the digestive tract,scan repeatedly with the ultrasonic probe,observe the origin layer, size, echo, boundary and peripheral lymph nodes to make a preliminary diagnosis.7.5～10MHZ ultrasonic probe was used.2.2ESD and STER:Patients performed ESD under the nasal or oral endotracheal intubation general anesthesia in the early stage(2010.12-2012.9),ESD steps include: make markers,submucosal injection,circular precut submucosal,dissection,wound treatment and specimen.ESD or STER were perfomed under the nasal or oral endotracheal intubation general anesthesia in the later stage(2012.10-2013.3),STER steps include:make markers,submucosal injection, set up the tunnel, dissect lesion in tunnel, wound treatment or close the tunnel and specimen.The lesions were definitely diagnosed by pathology, dyeing method was hematoxylin eosin stain (HE stain), and observed the cut edge residue and complete resection.Fast postoperative1～3days, intravenous use of proton pump inhibitors, hemostatic, nutritional support, take oral proton pump inhibitors4weeks after discharge. 2.3Follow-up:Patients reexaminated gastroscope in1,3,6,12months postoperative to observe the wound healing and whether relapse.Using SPSS13.0software for statistical analysis, The expression of measurement data use mean±standard deviation (x±s), With pathology as the gold standard, the lesion’s nature or origin level diagnosed by EUS compared with pathology using kappa coefficient and the McNemar test; the complete resection of ESD compared with STER using Fisher’s Exact Test,P≤0.05is assumed significant differences.Results:1.40patients suspected with gastric ectopic pancreas by electronic gastroscope were included,all patients accepted EUS examination and endoscopic resection.30ectopic pancreases,6stromal tumors,4leiomyoma with38originated in Submucosal,l part infiltrate the superficial of muscularis propria,1in muscularis propria according to EUS examination.25ectopic pancreases,5inflammatory lesions,4leiomyomas,2stromal tumors,2low grade intraepithelial neoplasias1nerve fiber sheath tumor,1lymphadenia with36originated in submucosal,3part infiltrate the superficial of muscularis propria,1in muscularis propria were final diagnosed by histology. The sensitivity and specificity of EUS in the diagnosis of gastric ectopic pancreas separately was80%and90%, EUS in the diagnosis of ectopic pancreas compared with pathology has no significant difference (P=0.125),consistent coefficient k=0.60,P<0.001.The sensitivity and specificity of EUS in the diagnosis of gastric submucosal lesion level separately was94.7%and100%, EUS in the diagnosis of lesion level compared with pathology has no significant difference (P=0.500), consistent coefficient k=0.643, P<0.001.2.32in40patients used ESD,29cases got complete resection(90.6%);8in40used STER,7cases got complete resection(87.5%), ESD compared STER in complete resection rate had no significant difference (P=1.000).The complete resection rate of all lesions was90%(36/40),1patient with stromal tumor changed to receive laparoscopic surgery cause the vascular of lesions hemorrhage blurry vision within STER, other3ectopic pancreases were not complete resection as the pancreas tissue infiltrating to the superfical muscularis propria lead to residue, so used the argon plasma coagulation (APC,60w power) coagulated residual organization to dark brown, no recurrence occured. The surgery took an average of52.1min(35-70min) and average5.2days hospitalization postoperative.3. There were15men and10women in25gastric ectopic pancreas,25cases had25lesions,15lesions with smooth surface,10lesions with central depression;Of the25patients,20lesions were located at the antrum,3fundus-body of stomach,2body of stomach;20pancreatic tissue were crumby,5were diffused distribution.The complete resection rate of ectopic pancreas was88%(22/25).4.1patient(2.5%) developed a massive delay-bleeding after the ESD which was stopped with hemoclips.None perforation occurred during operation and postoperation.The wound had healed in1-3months by reexamination endoscopy. No recurrence was observed in patients followed up1to30months.Conclusions:1. The apophysis lesions in the submucosal in gatric, especially in gastric antrum should be considered the possibility of ectopic pancreas regardless of whether has central depression, and should be differentiated with leiomyoma, stromal tumor, nerve fiber sheath tumor, lymphadenia;2. EUS play an important role in the diagnosis of gastric ectopic pancreas, the diagnosis of lesions level origin may be more accurate than nature,play an important guiding role in ESD or STER; 3. ESD could resect the whole lesion to offer an accurate pathology diagnosis, meanwhile good for treatment,ESD is an effective and relatively safe method for gastric ectopic pancreas;4. STER may be a new approach for gastric ectopic pancreas, the reseach is the first reported, but the cases are less at present and still need further study.