This technology gives full play to the respective advantages of soft and hard mirrors, complementing each other’s strengths and creating favorable conditions for each other, making up for the shortcomings of a single endoscope or laparoscope, making certain difficult problems easy to solve and further expanding the application fields of minimally invasive technology. Laparoscopy has not only been limited to simple cholecystectomy, but also has been widely carried out in the treatment of common bile duct stones by combined laparoscopy (laparoscopy + choledochoscopy) and triple-laparoscopy (laparoscopy + choledochoscopy + duodenoscopy), and has obtained good results. At present, the combination of laparoscopy and gastroscopy or enteroscopy is also more mature in the treatment of benign lesions and early cancers of the gastrointestinal tract. Here, combining my own experience, I will mainly talk about the application and evaluation of the combination of laparoscopy and gastroscopy in the minimally invasive treatment of gastric tumors. The combination of laparoscopy and gastroscopy was initially applied to some gastric polyps that could not be removed by endoscopy. For example, wide based polyps with wide base, most of them cannot be completely resected at one time under endoscopy, and there is a high risk of bleeding and perforation in multiple resection tours; in addition, for laparoscopic early gastric benign tumor surgery, it is difficult to locate such lesions because the appearance of gastrointestinal wall is mostly unchanged and the simple laparoscopy lacks the sense of hand touch. In order to avoid unnecessary open surgery and ensure precise intraoperative positioning, the combined laparoscopic gastroscopic technique was born. In 2003, the author started to apply this technique to perform 26 cases of gastric mesenchymal tumor resection, and the operation was very smooth and the results were precise. Leng Meiqing et al. achieved good results in 15 cases of large gastric polyps resected by combined gastroscopic-laparoscopic bimicroscopy. Many foreign surgeons have also used this technique for the surgical resection of benign gastric tumors, and all of them have achieved good results, which indicates that there is a broad prospect for the application of combined bimicroscopic techniques in benign diseases. In the author’s opinion, with the emergence of endoscopic mucosal resection (EMR) and endoscopic mucosal dissection (ESD) in recent years, they have partly replaced the surgical treatment of benign and early tumors in the gastrointestinal tract, but there are still limitations and potential risks of pure endoscopic treatment. For polyps that are larger in size or have malignant changes, the pursuit of endoscopic treatment is associated with a high incidence of complications such as bleeding and perforation, and a high rate of postoperative recurrence, and these problems deserve the attention of the majority of endoscopists. For example, for some early-stage tumors with mucosal resection, partial gastrectomy can be performed with the support of bimicroscopic combination, which can effectively reduce various risks. Gastric Dieulafoy’s disease is a rare but not uncommon cause of upper gastrointestinal bleeding, and with increasing understanding, its diagnosis and treatment will become more mature, and minimally invasive treatment is the direction of its development. Gastric wedge resection using the combined double-scope technique for the treatment of gastric Dieulafoy’s disease not only ensures the accuracy and integrity of the lesion resection, but also reduces the chance of miscutting and abdominal contamination without the need to open the gastric wall for exploration, while shortening the operation time, reducing bleeding, reducing trauma and fast postoperative recovery. The author successfully treated a case of gastric Dieulafoy’s disease with the combined technique of dual scopes, and the results were very satisfactory, with effective and rapid hemostasis and elimination of the pain of open surgery. Zhang Peng et al. reported 20 cases of gastric Dieulafoy’s disease treated by combined bimicroscopy, all of which achieved excellent results. In addition, the combination of two scopes is also valuable for lower esophageal hemangioma. Application in early gastric cancer The application of combined bimicroscopic techniques in early gastric cancer includes two aspects: precise localization and endoscopic treatment. Compared with laparoscopic colorectal cancer surgery, gastric cancer surgery requires high surgical techniques due to rich blood supply, many anatomical levels and complex anastomosis, so laparoscopic surgery for gastric malignant tumors starts to develop slowly. For early gastric cancer that only invades the mucosal layer and has no lymph node metastasis, laparoscopic local gastric resection, such as laparoscopic wedge resection (LWR) and intragastric mucosal resection (IGMR), can be used. In Japan, 1428 cases of LWR and 260 cases of IGMR have been performed in the past 10 years with good short-term outcomes [10]. Ohgami et al [11] reported 111 patients with early gastric cancer who underwent laparoscopic partial gastrectomy, among which no major complications occurred in one case, and only two cases of recurrence (1.8%) were reported, demonstrating the safety and efficacy of this procedure for early gastric cancer. The safety and efficacy of this procedure in treating early gastric cancer are worthy of recognition. For early gastric cancer with suspected lymph node metastasis, laparoscopic assisted distal gastrectomy (LADG) should be chosen. The conclusion was made. However, the appearance of the gastric wall in early gastric cancer is mostly unchanged, and laparoscopic surgery lacks the sense of touch by hand, which makes it difficult to precisely locate the lesions in the stomach, and with the combination of gastroscopy and laparoscopy, this problem is well solved. Surgical modalities of combined bimicroscopy applied in gastric tumor The surgical modalities of combined bimicroscopy are diverse, including gastric wedge resection, intraluminal resection and partial gastric resection (Bi I or II type GI reconstruction), partial gastric resection, standard resection, early gastric cancer radical treatment, etc. The author believes that they are mainly divided into two aspects: first, gastroscopy-assisted laparoscopic surgery; second, laparoscopy-assisted gastroscopic subsurgery. Gastroscopy-assisted laparoscopic surgery Gastroscopy-assisted laparoscopic surgery includes: ① laparoscopic extragastric partial gastrectomy: it is more suitable for lesions in the fundus, anterior wall of the stomach and posterior wall of the stomach near the greater curvature side, and after first separating the lesions around the lesions and holding up the lesions with non-invasive forceps, a wedge-shaped partial gastrectomy can be performed directly with a cutting suture outside the stomach lumen under laparoscopy. For anterior wall lesions near the pyloric canal and cardia, the lesions can also be directly excised with ultrasonic knife around the base of the lesion for 1 week, and the gastric wall incision can be manually closed with sutures; ② laparoscopic intraluminal partial gastrectomy: for posterior wall lesions near the pyloric canal and cardia, especially for intraluminal lesions, it is easy to remove too much normal gastric wall tissue with cutting and suturing device via extraluminal gastrectomy, resulting in gastric stenosis, so for these locations The author used this procedure for a case of intraluminal growth type mesenchymal tumor in the posterior wall of the gastric sinus near the pylorus, but this procedure puts the general Trocar directly through the abdominal wall into the gastric cavity, which is prone to gas leakage out of the gastric cavity through the edge of the puncture site, resulting in unsatisfactory expansion of the gastric cavity and affecting the surgical operation, so it is recommended that a puncture trocar with a balloon at the end be used. Laparoscopic-assisted gastroscopic surgery Laparoscopic-assisted gastroscopic surgery mainly consists of gastroscopic high-frequency electrocautery resection combined with laparoscopic gastric wall suture reinforcement: for tumors with intracavitary growth in the antral wall of stomach, such as wide tip or large tumor, simple gastroscopic resection of the mass is prone to perforation, bleeding and other complications. The procedure requires close cooperation between gastroscopic and laparoscopic surgeons. Gastroscopic electrocautery resection should be performed in order to remove the lesion completely, without concern for perforation. After resection, the gastroscope should carefully check whether the resection is complete, the depth of resection and the degree of thermal damage to the tissue after electrocautery. If the electrocautery time is not long, the defect only involves the mucosa or submucosa after resection, or only involves the superficial muscle layer, the treatment ends here, and drugs to inhibit gastric acid secretion are given after the operation. If perforation occurs after resection or if the wound is deep and thermal damage to the trabecular tissue is obvious, laparoscopic repair or suture reinforcement of the gastric wall is required. The suture must be accurately positioned under gastroscopic guidance, and the scope of the suture must exceed the trauma and be examined completely in combination with gastroscopy. There is no authoritative classification of the combined procedure and further summary is needed. Clinical application value of combined laparoscopy and gastroscopy I. Combined laparoscopy and gastroscopy can broaden the scope of minimally invasive surgery: for smaller tumors or narrow-tipped polyps in the stomach, they can be removed by gastroscopy. If the tumor is larger or has a wider tip, complications such as perforation and bleeding are likely to occur when the mass is removed by gastroscopy alone. For gastric mesenchymal tumors that cannot be removed by gastroscopy or have risks such as perforation, open surgery was often required in the past. Laparoscopic surgery is often unable to accurately locate relatively small masses in the gastric cavity by instruments due to the loss of direct palpation by the hand, which is one of the problems of laparoscopic surgery. With the combined dual-scope technique, the endoscope can accurately suggest the lesion site for the laparoscope and assist it to complete the surgery, which is a good solution to the localization problem. In addition, for tumors in the posterior wall of the stomach, conventional laparoscopic exploration is difficult to find tumors directly and tissue separation is required. In contrast, gastroscopy not only can directly detect the tumor, but also can assist in performing gastric antral wall stoma gastrectomy wedge resection. In addition, after laparoscopic gastric mesenchymal resection is completed, gastroscopy can also examine the anastomosis for bleeding, stenosis, and distortion, and can directly observe the blood supply to the anastomosis to avoid the occurrence of related complications. Second, the combination of laparoscopy and gastroscopy can improve the safety and quality of surgery: ① laparoscopic surgery is performed under the direct vision positioning of gastroscope for complete resection of lesions, which avoids leaving behind lesions and also avoids removing too much normal stomach wall. ②With laparoscopy as a back-up, more patients can have the opportunity to try gastroscopic electrocautery for tumor removal without having to worry about complications such as perforation and bleeding, which improves the level of minimally invasive surgery. ③Laparoscopic suture reinforcement of gastric wall makes complications such as perforation and bleeding significantly reduced, while gas injection through gastroscope can be used to check for stenosis and air leakage, which ensures the quality of surgery. Problems of bimicroscopic combination in gastric tumor The bimicroscopic combination has various benefits, but some problems have been encountered in the current application. The operation requires multidisciplinary cooperation, and it is easy for surgeons, endoscopists, anesthesiologists and nurses to wait for each other, which prolongs the operation time. There are relatively more instruments such as anesthesia machine, laparoscope and endoscope in surgery, and when the operating room space is small, the placement may affect each other, but in recent years, there is an imaging work platform that integrates laparoscope and endoscope into one, which can effectively save the operating room space and will also promote the development of combined double-scope surgery. In addition, there is a lot of room for improvement for the combined bimicroscopic technique which mainly plays a role in intraoperative precise positioning. The author has also made an attempt in this regard by applying preoperative Melan and submucosal injection of activated charcoal masses for localization. Due to problems such as diffusion too fast no suitable dye has been found yet. We have reason to believe that finding a suitable preoperative localization dye is the future direction, because it can avoid the problems of time and resource wastage caused by intraoperative double-mirror combination.