Application of Self-Pulling and Latter Transection in Totally Laparoscopic Total Gastrectomy

Background: To investigate the safety and ecacy of self-pulling and latter transection in totally laparoscopic total gastrectomy (SPLT-TLTG). Methods: Eighty patients with gastric cancer who received either SPLT-TLTG or laparoscopic-assisted total gastrectomy (LATG) were enrolled for this study from January 2016 to June 2018. Clinical data including clinicopathologic parameters, postoperative conditions and long-term prognosis were collected and compared between patients received different types of surgeries. Results: Compared to LATG, patients who received SPLT-TLTG surgery were associated with shorter operation time, less intraoperative blood loss and smaller incision lesion. In addition, patients who received SPLT-TLTG surgeries spent signicantly less time in bed-rest post-surgically, to rst bowel movement, hospital stay and before rst oral food-intake (P < 0.05), as long as lower postoperative pain scores. However, no signicant difference was observed between SPLT-TLTG and LATG surgeries in terms of how many lymph nodes (LNs) were retrieved during operation, as well as the overall incidence of postoperative complications (P > 0.05). Conclusions: This pilot study provided primary evidence for the application of self-pulling and latter transection in totally laparoscopic total gastrectomy in the treatment of gastric cancer.


Introduction
The gastric cancer (GC) is the second most popular and the third lethal cancer among all malignant tumors in China [1] . Despite improvements in early diagnosis and systemic therapy [2] , gastrectomy is still recommended for patients with early and moderate stages of gastric cancer. Since the Laparoscopic gastrectomy (LG) was rst performed on early gastric cancer in 1991 [3] , it has been welcomed worldwide due to the minimal lesion and limited blood loss. Generally, LG includes totally laparoscopic total gastrectomy (TLTG) and laparoscopic-assisted total gastrectomy (LATG). Compared with LATG, TLTG surgery is less invasive and requires shorter operation time, in addition to faster postoperative recovery and shorter hospital stay. However, the technique di culties, especially during anastomose, impedes the wide use of this advanced surgery. A Chinese surgical team introduced a new anastomosis method, selfpulling and latter transection (SPLT) esophagojejunostomy after traction based on the overlap and functional end-to-end anastomosis (FETE) in TLTG [4] [5] . Their study indicated that SPLT is a simple and secure process that helped to apply TLTG surgery on patients with more advanced stages. Moreover, less than ve endoscopic linear staplers is required for lesion closure in this procedure, demanding much less in both clinical costs and surgical skills [5] . However, no comparison between SPLT-TLTG and LATG surgeries have been conducted to the best of our knowledge.
In this study, we examined and compared the safety and e cacy between SPLT-TLTG and LATG surgeries in patients with GC.

Inclusion and exclusion criteria:
Inclusion criteria as 1) The diagnosis was made based on electronic gastroscopy examination and con rmed by pathological examinations.
Exclusion criteria as 1) Established distant metastasis 2) Patients who received neoadjuvant radiotherapy and chemotherapy before the operation; 3) History of surgical treatments for gastric cancer.

Surgical procedures
Firstly,patients were intubated under general anesthesia and maintained a modi ed lithotomy position.
Five-hole Trocars were placed routinely at the preparatory stage. (Fig. A). Secondly, the liver, abdominal cavity, pelvic cavity and mesentery were examined carefully. Patients with distant metastasis and invasion of perigastric organs were exclude from further operation. Then laparoscopic gastrectomy (total gastrectomy + D2 lymph node dissection) was conducted. Thirdly, the esophagogastric junction was ligated with a sterilized rope in SPLT group to facilitate the traction of the esophagus. A small pinhole was made by ultrasonic scalpel on the right side of the esophagus, about 3cm above the ligation rope (Fig. B). Then the jejunum was lifted away for 30cm to ligament of the Treitz. Another 1cm pinhole was made at the mesenteric margin. A side-to-side esophagojejunostomy(E-J) was performed through these two holes (Fig. C) and the entry hole was closed with a linear stapler (Fig. D). Next, a side-to-side jejunojejunostomy was performed between the afferent loop stump and the roux limb 40cm below E-J, meanwhile another entry hole was formed and closed. A drainage tube near the upper abdominal duodenal stump was placed after anastomosis was conducted. The sample bag of the stomach was removed through a small incision in the navel (Fig. E).
LAG: laparoscopic gastrectomy was performed conventionally as introduced before. Brie y, 5cm incisions were made below the xiphoid process before the digestive tract reconstruction which was performed similarly as in open surgery (Fig. F).

Clinical parameters
Intraoperative and postoperative clinical parameters include total operation time, digestive tract reconstruction time, intraoperative blood loss, numbers of retrieved lymph nodes (LNs), postoperative offbed activities time, time to rst atus, time to rst oral food intake and total postoperative hospital stay were collected. Prognosis and complications include postoperative anastomotic leakage, anastomotic bleeding, anastomotic stricture, abdominal bleeding, intra-abdominal infection, disturbance of gastric emptying, pancreatic and biliary stula were also collected.

Follow up
All patients were followed up by outpatient clinic or telephone. Clinical parameters including imaging, blood routine test, serum biochemical test, tumor marker detection, abdominal CT and gastroscope were evaluated as appropriate.

Statistical analysis
All statistical calculations were conducted using Statistical Product and Service Solutions (SPSS) version 18.0 statistical software. Continuum data was described as means ± standard deviation and analyzed by Student t-test. Kaplan-Meier method was applied when depicting the survival curve. P values < 0.05 were considered as statistically signi cant.

Patient demographics and pathologic ndings
The baseline characteristics between two groups were comparable and no signi cant difference was identi ed. (Table 1)

Surgical outcomes
No signi cant difference in the numbers of retrieved LNs was identi ed between two groups. However, the operation time and digestive tract reconstruction time were signi cantly shorter in patients who received SPLT-TLTG group. In addition, patients in the SPLT-TLTG group suffered a smaller incision lesion than patients in the LATG group (P < 0.05). Moreover, the intraoperative blood loss was less severe in SPLT-TLTG group than in the LATG group. (Table 2).

Postoperative outcomes
Our results showed that patients who received SPLT-TLTG surgery covered faster than those who received LATG surgery. The time to off-bed rehabilitation, rst atus, rst oral food intake and total postoperative hospital stay were signi cantly shorter in the SPLT-TLTG group than in LATG group (P < 0.05). Meanwhile, the average pains score was also decreased in the SPLT-TLTG group. (Table 3)

Postoperative complications
There was no signi cant difference of postoperative complications between the 2 groups (P > 0.05). Among all patients, 2 cases of postoperative infection were reported in the laparoscopic assistant group and were successfully treated with third-generation cephalosporin antibiotics. Each group has 1 case of intra-peritoneal or digestive tract hemorrhage and was treated with hemostatic and somatostatin. Each group has 1 case of anastomotic stula and was treated conservatively with food restriction, acid inhibition and parenteral nutrition. Two patients in the laparoscopic group had disturbance of gastric emptying and were treated with traditional Chinese medicine and acupuncture. No pancreatic stula, biliary stula and esophageal re ux was reported in the two groups. (Table 4)

Prognosis of the two Groups
No patient died during the 18 months follow-up period. The median recurrence time was 16 months in SPLT-TLTG group and 15 months in LATG group, which was not signi cantly different. (Fig. G)

Discussion
Due to the limit of current technique, it is important to develop a safer and more reliable digestive tract reconstruction method after total laparoscopic radical resection [7] . It has been known that Roux-en-Y anastomosis can effectively reduce the occurrence of re ux esophagitis and maintain good nutritional status and is currently the main reconstruction method [8] . This study examined the e cacy and safety of SPLT-TLTG surgery compared to conventional LATG surgery. Consistent with other studies [4][5]9] , our study suggested that SPLT-TLTG surgery has the advantages of minimally invasive, reduced bleeding and rapid postoperative recovery. Meanwhile, avoid squeezing tumor tissue during the operation, which diminishes the risk of rupture and dissemination of the tumor during the operation [9] . Furthermore, the SPLT-TLTG is more suitable for patients who are obese and have narrow rib arch [11] . This case-control study compared and analyzed the clinical data intraoperative and postoperative of SPLT-TLTG and LATG gastric cancer surgery, and our results are consistent with the ndings that TLTG was safer and more bene cial to patients [10] [12]- [16] . Speci cally, compared to LATG, the advantage of SPLT-TLTG surgery includes: (1) Better visualization during operation. The direct use of linear cutting suture device in anastomosis is more accurate and can prevent secondary injury, anastomotic stenosis and stula induced by improper traction [17] . (2) The incision lesion is smaller compared to LATG surgery and does not require manual suture for lesion closure. (3) The operation process is less technique demanding. The procedure was completed under laparoscopic therefore has better visualization [18] . (4) The time to offbed rehabilitation, rst atus, rst oral food intake and total postoperative hospital stay were signi cantly shorter in patients who received SPLT-TLTG surgery (5) The SPLIT-TLTG surgery has a reliable safety pro le partially due to the side-to-side esophagojejunostomy during operation is much safer than conventional round anastomosis [19] [20] . Gong et al [21] suggested that linear stapler, but not circular stapler, should be used in TLTG surgery.
This study had several limitations. Firstly, the nature of the study was a retrospective analysis of prospectively collected data and might presented with some inherent biases. Secondly, the follow-up period was relatively short and long-term safety of this novel technique was not evaluated. Thirdly, other confounding factors that might exist in the baseline and affected the results. More studies include larger population are needed to better con rm the e cacy and safety pro le of this novel technique.

Conclusions
In conclusion, SPLT Roux-en-Y anastomosis with totally laparoscopic total gastrectomy has the advantages of shorter operation duration, minimally invasive, quick recovery and shorter hospitalization time compared with laparoscopic assistance gastrectomy, which is worthy of clinical popularization and application.
Declarations Acknowledgements Not applicable.

Availability of data and materials
All data generated and/or analyzed during this study are included in this article.

Authors' contributions
Yang Zhao and Tao Li performed the surgery. Dong Song and Tao Wang assisted in the surgery. Zhi-Xia Bai performed statistical analysis and assisted with drafting of the manuscript. Yang Zhao wrote the manuscript. All authors read and approved the nal manuscript.
Ethics approval and consent to participate Written informed consent was obtained from all patients for the use of their tissues for research purposes, and the study protocol was approved by General Hospital of Ningxia Medical University Ethics Committee (Yinchuan, China). Patient consent for publication Not applicable.

Competing interests
No potential con ict of interest relevant to this article was reported.
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