Mesenchymal tumors of the gastrointestinal tract originate from the mesenchymal tissue of the GI tract and are tumors of primitive mesenchymal stem cells with multidirectional differentiation potential and potentially malignant biological behavior. Mesenchymal tumors can occur in any part of the GI tract, with the stomach being the best site for mesenchymal tumors, accounting for 50%-60% of this disease. For mesenchymal tumors that have not metastasized, surgical resection is currently considered to be the treatment of choice. Since mesenchymal tumors tend to grow exophytically and expansively rather than diffusely and infiltratively, the prognosis is not affected by extended excision of the lesion or lymph node dissection, so complete local excision is currently recognized as the most effective treatment worldwide. These biological characteristics of mesenchymal tumors allow the advantages of minimally invasive surgical techniques to be fully realized. In recent years, with the continuous development and maturation of minimally invasive surgical techniques such as laparoscopic surgery and endoscopic surgery, and the continuous improvement of surgical concepts, “safe, effective, rational and minimally invasive” surgery has become the mainstream of modern surgical development. The combined laparoscopic and endoscopic technique has emerged as a more mature minimally invasive surgical approach in the treatment of mesenchymal tumors. Early detection and early treatment is the only effective way to improve the prognosis of mesenchymal stromal tumor. With the advances in gastrointestinal endoscopic techniques and instruments, most of the microscopic mesenchymal tumors can be treated by endoscopy to avoid unnecessary trauma. When endoscopic treatment of mesenchymal tumors is not possible, laparoscopy is another important means of minimally invasive treatment. Laparoscopic surgery has the advantages of less trauma, less patient pain and faster recovery. Nowadays, laparoscopic techniques have been maturely applied to the surgical treatment of gastric mesenchymal tumors and become one of the important surgical procedures. However. Both endoscopic treatment and laparoscopic surgery inevitably have certain limitations. The limitations of endoscopic treatment alone are: (1) for mesenchymal tumors of large size (>5 cm in diameter) in the stomach, endoscopic treatment is difficult to operate; (2) because most gastric mesenchymal tumors originate from the intrinsic muscular layer, and only a few originate from the mucosal muscular layer, and are rich in blood vessels, safe and complete resection of the tumor under endoscopy is more difficult. In addition, endoscopic treatment usually relies on energy cutting to complete, but it is difficult to find the balance point of energy cutting, which is easy to cause too much or too little energy, so the risk of complications such as bleeding and perforation is relatively high, which is also the main reason leading to intermediate open surgery. Moreover, it is difficult to fully judge the infiltration depth of gastric mesenchymal tumor under direct endoscopy, and there is a possibility of insufficient resection scope and positive cutting edge; (3) for some special sites, such as mesenchymal tumor in the area of gastric cardia and pyloric duct. Endoscopic treatment is more difficult to be removed by trapping and electrocautery. The main limitations of laparoscopic surgery are: (1) due to the lack of “tactile feedback” from the hand, it is difficult to localize the tumor when using this technique alone for intracavitary type, especially for small gastric mesenchymal tumors; (2) laparoscopic resection of mesenchymal tumors close to the cardia may cause postoperative cardia stenosis. In recent years, the combined technique has gradually become an important surgical modality for the treatment of gastric mesenchymal tumors. The combined technique can not only accurately locate the tumor, but also observe whether the resection is complete, whether there is bleeding in the cavity after resection, whether the closure is tight and whether the gastric cavity is stenosed after closure, thus avoiding the missed diagnosis or delayed treatment of related complications, increasing the safety and effectiveness of surgery and improving the quality of life of patients after surgery. The combined bimicroscopic technique is safe and effective in the treatment of mesenchymal tumor and has a good development prospect, which not only ensures complete resection of the tumor, but also preserves the normal gastric wall tissue to the maximum extent. According to the different localization of gastric mesenchymal tumor, there are 2 main forms of combined bimicroscopic techniques: laparoscopic-assisted endoscopic surgery and endoscopic-assisted laparoscopic surgery. Among them, endoscopy-assisted laparoscopic surgery can be subdivided into: endoscopy-assisted wedge resection, endoscopy-assisted transgastric resection endoscopy-assisted laparoscopic non-excisional surgery. Clinical application of combined bimicroscopic techniques in the treatment of gastric mesenchymal tumor The accuracy of gastric mesenchymal tumor localization depends on preoperative examination, especially the localization of the level of mesenchymal tumor origin, which is important for the choice of surgical approach. Gastroscopy is the preferred method for examining gastric mesenchymal tumors. Under the direct view of endoscopy, the lesion site and morphology can be clearly seen, and supplemented by CT and MRI, the localization of mesenchymal tumors and the presence of distant metastases can be more precisely determined. For mesenchymal tumors originating from the submucosa and muscular layer, the depth of invasion cannot be judged by direct endoscopy, and the determination of malignancy depends more on immunohistochemical examination (split count, CDIl7, etc.), therefore, for these cases, preoperative ultrasound endoscopy is very helpful for tumor localization and initial characterization. Laparoscopic-assisted endoscopic surgery The laparoscope closely monitors the endoscopic resection of the tumor during the entire procedure and can promptly manage possible complications such as perforation and bleeding. In addition, during the endoscopic resection of tumor, the laparoscope is used to push and pull the stomach wall, which can make the tumor more obviously exposed to the endoscope for resection. Laparoscopic-assisted endoscopic surgery is mainly suitable for mesenchymal tumors that are resectable endoscopically, do not infiltrate deeper than the submucosa, and are difficult or risky to treat endoscopically alone. The conventional treatment modalities of laparoscopic-assisted endoscopic surgery include loop ligation, endoscopic mucosal resection (EMR), and endoscopic submucosaldissection (ESD). It is usually considered that the appropriate margin should be 1-2 cm from the tumor, and this increases the risk of endoscopic resection alone. With the aid of laparoscopy, the additional trauma to patients due to complications caused by endoscopic resection can be significantly reduced, increasing the safety of endoscopic resection and the resection rate of the tumor. In conclusion, endoscopy still dominates the treatment in laparoscopic-assisted endoscopic surgery technique, and the laparoscope only plays an auxiliary and surveillance role, so the surgical trauma is similar to that of endoscopy, which achieves the effect of reducing trauma and avoiding overtreatment. Endoscopic-assisted laparoscopic surgery Endoscopic-assisted wedge resection Intraoperative tumor resection is mainly performed by laparoscopy, and the endoscope mainly plays the role of tumor localization, usually being used for mesenchymal tumors in the antrum and large and small curves of the stomach. After combined dual-scope localization, resection of mesenchymal tumors in the anterior wall of the stomach can be performed by pulling up the diseased gastric wall around the tumor using tissue forceps or suture traction, and then placing the cutter at the posterior part of the tumor to cut down the tumor completely. It is also necessary to ensure the negative cut margin; after the incision is sutured, the anastomosis can be checked again under endoscopy to clarify whether there are complications such as bleeding and stenosis at the anastomosis. During tumor resection, no matter endoscopic or laparoscopic, it is necessary to avoid touching the tumor as much as possible to prevent tumor rupture and cause abdominal implantation and metastasis. In endoscopic-assisted transgastric resection, after locating the tumor endoscopically, the antral wall of the stomach is incised laparoscopically and the gastric cavity is reached. The stomach wall with the tumor is lifted with sutures or tissue forceps and the tumor is finally removed. This is usually indicated for patients with mesenchymal tumors located in the posterior wall of the stomach where endoscopic-assisted wedge resection is not possible. The endoscope plays an important role in this procedure for laparoscopic access to the gastric cavity. The location of the posterior gastric wall where the tumor is located can first be clarified by looking at the endoscopic screen, and then using fluoroscopic techniques. This allows the laparoscope to avoid the large blood vessels when cutting through the anterior wall of the stomach. After tumor resection, endoscopic observation of the anterior-posterior wall anastomosis is required. Endoscopic-assisted laparoscopic non-excisional surgery For non-excisional surgery requiring endoscopic assistance, including laparoscopic fundoplication, laparoscopic sleeve resection, and laparoscopic gastric diversion. In this operation, the laparoscope completes the main part of the operation, and the endoscope plays the role of guidance, support and positioning as an auxiliary. Summary and outlook As an emerging minimally invasive surgical technique in recent years, the combined bimicroscopic technique has high application value in gastric mesenchymal tumor, and endoscopy and laparoscopy can complement each other’s advantages, compared with simple laparoscopic surgery, endoscopic treatment and open surgery. It brings higher safety, less trauma, lower postoperative complications and recurrence rate for patients, and also provides new ideas and treatment means for minimally invasive treatment of gastric mesenchymal tumor. It is believed that with the continuous exploration and practice of clinical surgeons at home and abroad, the combined dual-scope technique will have a wider application prospect.