Modified Laparoscopic Intragastric Surgery And Endoscopic Full-thickness Resection For Gastric Stromal Tumor Originating From The Muscularis Propria

BackgroundsGastrointestinal stromal tumors (GIST) are the most common mesenchymal and potentially malignant tumors of the gastrointestinal tract. Presently, it is considered that GISTs originate from stem cells that differentiate toward interstitial Cajal expressing tyrosine kinase receptors KIT or platelet-derived growth factor receptor alpha (PDGFRA). GISTs can arise anywhere along the gastrointestinal tract but are most common in the stomach, and gastric stromal tumor (GST) accounts for60%-70%.Currently, the annual incidence of GST in America is about0.7per100,000. But in China, the incidence and survival have not been clear. Most of GSTs originate from the muscularis propria, rarely from muscularis mucosa. The symptoms, which depend on tumor size, location and malignant degree, are usually nonspecific. Incidental discovery accounts for approximately one third of the cases. The clinical symptoms including hematemesis, melena, abdominal distension, abdominal pain, abdominal mass, nausea, vomiting and other symptoms. The commonest presentation is bleeding related to mucosal erosion (approximately50%). There are no obvious clinical symptoms, if the tumor is small.Based on tumor size and mitotic rate, Fletcher et al. defined the risk of aggressive-behaviour of GIST. The prognostic scales including:very low risk (tumor diameter≤2cm, mitotic count<5/50high power field); low risk (tumor diameter2-5cm, mitotic count<5/50high power field); intermediate risk (tumor diameter<5cm, mitotic count5-10/50high power field or tumor diameter5-10cm, mitotic count<5/50high power field); high risk (tumor diameter>10cm, any mitotic count or>10/50high power field, any tumor diameter).Surgery remains the mainstay of therapy for patients with primary GST with no evidence of metastasis, and should be initial therapy if the tumor is technically resectable and associated with acceptable risk for morbidity. The goal is complete gross resection with an intact pseudocapsule and negative microscopic margins. Because GST rarely metastasizes to local lymph nodes, there is no need for subtotal gastrectomy or lymphadenectomy. GST should be handled with care to avoid tumor rupture. If the pseudocapsule is torn, bleeding and tumor rupture may ensue. At present, the operation methods for GST include:laparotomy, laparoscopic surgery, laparoscopic and endoscopic cooperative surgery (LECS) and endoscopic resection. Compared with the laparotomy, laparoscopic surgery has the advantages of minimally invasive and rapid recovery, the clinical application is more and more widely. Most tumors are laparoscopically resected with a linear stapler. Tumors involving the esophagogastric junction and pylorus are removed by laparoscopic proximal gastrectomy and laparoscopic distal gastrectomy. Laparoscopic surgery can be used to remove exogenous or larger stromal tumor. But for endogenous or smaller tumors, laparoscopy is difficult to precise positioning and resection. Laparoscopic and endoscopic cooperative surgery not only can located the tumor, but also can resect the GST completely. Conventional LECS is mainly divided into2types according to the different locations of GSTs:laparoscope-assisted endoscopic technique (LAET) and endoscope-assisted laparoscopic technique (EALT). The LAET technique mainly uses laparoscopy to monitor the endoscopic resection of tumors closely throughout the surgical process and timely treatment of perforation, bleeding, and other complications. However, when a tumor is too large or located in the posterior wall or gastric fundus, gastroscopy is very difficult to achieve. The EALT technique uses laparoscopic wedge resection with a linear stapler, with the gastroscopy playing an important role in locating the tumor. When the lesions are near to the cardia or pylorus, local excision can pose the risk of making passageways stenotic. Furthermore, it inevitably excises excessive normal tissue.With the development of endoscopic technology, endoscopic submusocal excavation (ESE) and endoscopic full-thickness resection (EFR) have been used for resection of the gastric tumors originating from muscularis propria. They are all minimal invasive, but they are too difficult for many endoscopist to master.In recent years, we have been trying to improve the deficiency of the traditional LECS and seek for a safe, effective and minimally invasive surgery. In the work, we developed a new type of LECS-modified laparoscopic intragastric surgery (MLIGS) for the treatment of GSTs originating from the muscularis propria.ObjectiveThis study aimed to introduce a new type of laparoscopic and endoscopic cooperative surgery (LECS)-modified laparoscopic intragastric surgery (MLIGS), and evaluate the feasibility and security of MLIGS and the endoscopic full-thickness resection (EFR) for the treatment of gastric stromal tumors (GSTs) originating from the muscularis propria.Methods1. From January2011to October2012,18cases of GSTs originating from the intraluminal muscularis propria layer were confirmed by endoscopic ultrasound (EUS) and computed tomography (CT) at Qianfoshan Hospital. No metastasis of GST was found. The patients consisted of7men and11women ages32-74years. All the cases were single occurrences. The tumors were0.8-4.5cm in size and located in the fundus (n=11), the posterior wall of the gastric corpus (n=2), the gastric cardia (n=3), the anterior wall of the gastric corpus (n=1), and the antrum (n=1). The patients voluntarily chose the operation method. Of the18cases,8were managed by MLIGS and10cases by EFR.2. MLIGS performed according to the following procedures:(1) The surgeon made a curved incision of approximately0.5cm at the superior border of the umbilicus. A carbon dioxide (CO2) pneumoperitoneum with a pressure of12mmHg was established, and a0.5cm laparoscope was inserted for observation.(2) The location of the tumor was determined by the endoscopist. Two punctures of approximately0.5cm were placed in the left upper quadrant of the abdomen then the pneumoperitoneum established.(3) Two sutures were placed in the avascular area of the stomachs anterior wall and exported from one of the puncture holes to pull the anterior stomach wall close to the abdominal wall.(4) The stomach was inflated during gastroscopy. Under laparoscope monitoring, the surgeon inserted two ordinary0.5cm puncture cannulas into the stomach from the anterior wall at a distance of more than3cm.(5) Under gastroscope guidance, the surgeon used an ultrasound knife to resect the tumor completely.(6) The specimen was removed via the mouth using grasping forceps.(7) If no perforation occurred, the two puncture cannulas in the gastric lumen were pulled out one by one, and the puncture holes were closed using titanium clips via the gastroscope. Otherwise, the perforation was clipped from the edge to the center using clips. The puncture cannulas then were pulled out, and the puncture holes were closed by clips. If the stomach was repeatedly inflated without a leak, the gas was emptied, and a gastric tube was inserted.(8) The pneumoperitoneum was reestablished, and the hanging lines in the stomach wall were removed. Intraperitoneal exudate and blood were fully sucked out. The pneumoperitoneum was removed when the surgeon pulled the puncture cannulas out of the abdominal wall, and the punctures were sutured subcutaneously.3. EFR performed according to the following procedures:(1) Marked dots around the lesion with APC.(2) A mixture solution (including100ml of normal saline, and1ml of epinephrine,1ml of indigo carmine) was injected into the submucosa.(3) Precutting of the mucosal and submucosal layers around the tumor was performed.(4) A circumferential incision was made as deep as the muscularis propria around the tumor using the standard endoscopic submucosal dissection (ESD) technique.(5) An incision into the serosal layer around the tumor, and active perforation around the tumor was performed. The gastric fluid and blood in stomach was sucked away, and the full-thickness incision to the tumor was completed.(6) The gastric wall was clipped defect.(7) The tumor was took out from mouth. 4. A20-gauge needle was used to relieve the pneumoperitoneum during and after the EFR procedure. A gastric tube was placed after the operation. Both antibiotics and proton pump inhibitors were used in two groups. Patients with bearable pain after the operation could be observed. Otherwise, painkillers were used. Every patient in the two groups received contrast roentgenography on postoperative day three. If neither contrast leakage nor disturbance of gastric emptying was found, the patient could take a liquid diet and a semiliquid diet one week later.Results1. The GSTs all were resected completely in the two groups. There is no severe postoperative complications in the MLIGS group, but one patient in the EFR group had peritonitis and peritoneal abscess, the other9patients had no postoperative complications.2. No significant difference was observed in tumor size (mean size,2.75vs1.65cm; t=1.727; P>0.05), hospital stay (mean days,7.5vs10.2days; t=0.832; P>0.05), or abdominal pain time (mean time,1.88vs7.2days; t=1.832; P>0.05) between the MLIGS and EFR groups. But compared with EFR group, the operation time and blood loss were significantly decreased in the MLIGS group (mean operation time,85vs120min; t=2.371; P<0.05; mean blood loss,20vs48ml; t=2.372; P<0.05).3. The pathologic results all indicated GSTs, and the structures of basal and cutting edge were normal. There were including:eight very low risk GSTs, seven low risk GSTs and three intermediate risk GSTs.4. During the first year after the initial procedure, follow-up gastroscopies were performed every3months. After1year, follow-up gastroscopies were performed every6months. All the patients received abdominal CT scan every6months for the first2years and yearly thereafter. The follow-up examinations showed no tumor recurrence in any of the18patients.ConclusionsBoth MLIGS and EFR are feasible and effective treatments for GSTs from the muscularis propria. EFR is more minimally invasive than MLIGS. On the other hand, the advantages of MLIGS over EFR are a shorter operation time; less risk of bleeding; use of laparoscopy in the event of perforation to suck out exudate and blood or to execute peritoneal washing, thereby reducing the chance of intraabdominal infection and other complications; and ability to observe the exterior of the gastral cavity by laparoscopy and the interior of the gastral cavity by gastroscopy, thus decreasing the incidence of postoperative complications.