Intra-abdominal bleeding, particularly the bleeding caused by injury to large vessels, is a major complication during laparoscopic surgery and a vital reason for open conversion. Ryu et al. [4] summarized 347 patients who underwent LADG; the common hepatic artery (CHA) and splenic artery (SpA) were injured in two and one patients, respectively, and there were two cases of diffuse bleeding from the surgical field. The rate of bleeding requiring open conversion was 1.4 % (5/347). There are five main reasons for this complication. First, accidental injury to the adjacent vessels may occur during dissection of the lymph nodes (LNs) around the stomach. For instance, during the process of No. 8 and No. 11 LN excision, the CHA or splenic vein may be damaged; or injury to Helen’s trunk, anterior superior pancreaticoduodenal vein, or colonic vein may occur when dissecting the No. 6 or No. 14v LNs. Second, insufficient identification of the vascular variation could result in hemorrhage, such as injury to the portal vein when dissection is carried out in patients without CHA, or mistaken damage to the left gastric vein (LGV) which locates at the dorsal side of the SpA when dissection of suprapancreatic LNs is performed. Third, the relevant organs and vessels are torn secondary to the application of excessive tension. For example, the spleen is torn when the greater omentum is pulled or the gastrosplenic ligament (SGL) is divided; and the LGV may be torn if the gastropancreatic fold (GPF) is elevated violently. Fourth, the anatomical plane is entered incorrectly because the layer is indistinctly identified. For instance, during the dissection of No. 6 LNs, the colonic vessels may be damaged because of incorrect entry into the plane of the transverse mesocolon. Fifth, the ultrasonic scalpel is used in an inappropriate way, such as clamping an excessive amount of tissue at one time, shearing with immoderate speed, insufficient clamping of the vessel, and other factors.

In conclusion, we consider that familiarity with the anatomical landmarks and accurate selection of the anatomical plane are crucial in preventing hemorrhage in LG. During the entire dissection process, surgery should be gradually performed from shallow to deep, enabling easy and accurate exploration of the intrafascial space. Additionally, the swollen LNs should be excised entirely to avoid bleeding from its stump. However, if vessels are injured and resultant bleeding occurs, the surgical assistant should rapidly suction blood to expose the bleeding site, while the surgeon clamps the vessel with a vascular clip to control the hemostasis. Compression with gauze is helpful for diffuse bleeding on the material organs as the pancreas, spleen, the stump of the LNs, and so on, and in uncontrollable intra-abdominal bleeding conversion to open surgery should be conducted decisively.

The DF is a major complication after radical gastrectomy. A multicenter study in Italy [5] demonstrated that out of 3,785 gastrectomies for malignant disease, a total of 68 DFs were observed (1.8 %). In addition, Orsenigo et al. [6] reported that the incidence of DF was 2.5 % (32 patients) in a study involving 1,287 patients who underwent LG and mean postoperative onset was 6.6 days. In our department, DF was present in eight patients (0.4 %) within an overall population of 2,170 patients. The main reasons for DF are as follows: first, the wall of the duodenum may be burned by the ultrasonic scalpel during the process of denuding; second, excessive tension is applied when the duodenum is severed with a linear cut stapler, leading to dropping of the suturing nail; and third, obstruction in the input loops of the jejunum results in excessive high pressure in the duodenum. Most of the DF can be cured by conservative treatment, such as abdominal cavity drainage and the use of parenteral nutrition and somatostatin. Surgical treatment can be necessary when the DF cannot be managed by the above treatments or other complications such as intra-abdominal bleeding are encountered [7].

With the development of the anastomat, incidences of anastomotic complications have been significantly reduced. Currently, anastomotic leakage, stricture, and hemorrhage are major complications related to anastomosis after gastrectomy. Of the 1,400 patients with gastric cancer who underwent gastrectomy in a study carried out by Tanizawa et al. [8], postoperative anastomotic hemorrhage was observed in 0.4 % of patients (6/1,400). Additionally, Tanimura et al. [9] evaluated 235 patients who underwent LG with D2 lymph node dissection and reported that anastomotic complications were present in 1.7 %, including leakage in two patients, anastomotic bleeding in one patient, and stricture in one patient. Our studies have shown that 1.6 % (35/2,170) of patients have suffered anastomotic complications after LG. Among these patients, bleeding, leakage, and stricture were observed in 0.5 % (11/2,170), 1.0 % (21/2,170), and 0.1 % (21/2,170), respectively. The onset of anastomotic hemorrhage usually occurs within 72 h postoperatively, mostly within 12–24 h [10]. Most of the patients can be cured by conservative treatment, while massive hemorrhage should be decisively managed by surgery. Moreover, some researchers have demonstrated that laparoscopic surgery was superior in the identification of the bleeding site, achievement of hemostasis, and evaluation of the risk of recurrent hemorrhage; it is thus the recommended treatment [11]. It has been reported that anastomotic leakage occurs in 0.5–5.9 % of patients [12–14]. From our experience, anemia and hypoproteinemia should be corrected preoperatively, and adequate blood supply and proper tension in the anastomotic stoma should be confirmed; all of these approaches facilitate the prevention of leakage. If improper anastomosis is detected after using a liner stapler, further suturing by hand should be performed to enhance it. Among patients with leakage, the majority only suffer from minor leakage which can be cured by conservative treatment. A study conducted by Kim et al. [15] has shown that, for tissue defects smaller than 2 cm in size, complete closure by means of endoscopy can be achieved in 73.1 % of patients (19/33), with an effective rate of 92.4 % (31/33). The study thus demonstrated that endoscopic treatment for anastomotic leakage smaller than 2 cm in size should be recommended. Severe leakage usually occurs in combination with an intra-abdominal abscess. Under such circumstances, unobstructed drainage should be maintained. Simultaneously, the placement of an intestinal nutrition tube in the jejunum using a gastroscope or X-rays and enteral nutrition is preferable. Anastomotic stricture after Billroth I anastomosis has been reported to occur at a rate of 1.1–8.0 % [16–19]. In addition, stricture may be associated with anastomotic leakage [20]. However, the size of stapler seems to be irrelevant regarding the incidence of stricture [21]. We should thus pay more attention to the prevention of leakage. The preferred treatment for stricture is endoscopic balloon dilation or stent implantation. Additionally, in our opinion treatment of patients with nutritional deficiency should involve placement of an endoscopic nutrition tube in the jejunum for enteral nutrition.

Occasionally, postoperative PF and acute pancreatitis are encountered after LG. Jiang et al. [22] concluded that the incidence of postoperative PF was 0.9 % (10/1,026) in their large-scale study. Park et al. [23] reported only two patients (0.7 %) were with a fistula in a study consisting of 300 patients who underwent LG. These findings were consistent with our data (5/2,170; 0.23 %). PF and acute pancreatitis are directly related to intraoperative injury to the pancreas. For example, the lingular lobe of the pancreas or the pancreatic tail may be incorrectly regarded as LNs during the No. 6 or splenic hilar lymph node dissection, respectively. Additionally, if the functional face of the ultrasonic scalpel is placed close to the pancreas during the process of separating the pancreatic capsule, the pancreatic parenchyma may be injured. PF can cause intra-abdominal infection or an abscess with a low incidence rate, even leading to systemic infection or a massive intra-abdominal hemorrhage, endangering the patient’s life. It should thus be noted by surgeons. When fistula occurs, persistent peritoneal lavage with double-sheath tube should be applied, together with the inhibition of pancreatic secretion. Surgical treatment for drainage and lavage should be performed if necessary.

Because of the common use of the ultrasonic scalpel for shearing and separating, the incidence of postoperative LF should in theory be lower than that for conventional open surgery. In our data from 2,170 patients who had undergone LG, no major LF (with a volume >1,000 ml/24 h) was observed. We conducted a statistical analysis of the data from 1,366 patients and found that postoperative minor LF (with a volume of 30–100 ml/24 h) occurred in 4.2 % of patients (57/1,366). The occurrence of LF is strongly linked with ignorance regarding the correct management of the stump of the lymphatic vessel. Therefore, wounds in the region of the No. 7, 8, 9, and 12a LNs should be focused on and clearly checked. If ivory or gelatinous fluid is detected, meticulous suture and placement of the drainage tube is vital. LF in the majority of patients can be healed by conservative treatment, such as fluent drainage, the use of parenteral nutrition, and maintenance treatment regarding the water electrolyte balance. However, the necessity for surgical treatment should be considered with caution.