Application of double needle-double layer continuous manual suture to complete digestive tract reconstruction in totally laparoscopic distal gastrectomy CURRENT

Retrospectively register the clinical data of distal gastric cancer patients who received surgical treatment, discuss the safety and feasibility of double needle-double layer continuous manual suture to complete digestive tract reconstruction in totally laparoscopic distal gastrectomy. Review the clinical data of 41 patients with distal gastric cancer from the gastroenterology department from 2018 to August 2019, were accepted the totally laparoscopic distal gastrectomy. During the operation, the method of double needle-double layer continuous manual suture was used for Billroth I type anastomosis to complete digestive tract reconstruction. The peri-operative clinical information and postoperative follow-up information were collected for analysis, and the clinical application value was evaluated. ; ± ± Positive


Background
In recent years, with the advanced development of laparoscopic techniques, totally laparoscopic gastrectomy has proven to be safe and feasible, especially, Totally Laparoscopic Distal Gastrectomy (TLDG) [1] . Choosing the ideal method for digestive tract reconstruction in distal gastrectomy is still the focus of controversy. Various methods of anastomoses by stapler has been heavily reported in previous researches such as using linear staplers to perform Delta-shaped anastomosis, Billroth II anastomosis or Roux-en-Y anastomosis [2][3][4] . However, there are still many problems, such as high anastomotic tension, inaccurate tumor margins and large expenses. Therefore, we started to perform totally laparoscopic hand-sewn Billroth I anastomosis with a new application of double needle-double layer continuous manual suture to complete digestive tract reconstruction and have finished 41 cases by far. We intend to analyze these cases and discuss the relevant issues about the new application in totally laparoscopic distal gastrectomy based on previously published researches and our own experiences.

Materials
Retrospectively register the clinical data of 41 patients with distal gastric cancer from the gastroenterology department of the Second Affiliated Hospital of Dalian Medical University, from September 2018 to August 2019, were accepted the totally laparoscopic distal gastrectomy. During the operation, the method of double needle-double layer continuous manual suture was used for Billroth I type anastomosis to complete digestive tract reconstruction.

Statistical method
All data analysis was done by SPSS 24.0 statistical software. The count data was measured by χ 2 test, the normal distribution measurement data was described by`x ± s, and the skewed distribution measurement data was described by median M (range), and the standard level α is 0.05, the difference was statistically significant when p < 0.05.   .88) The data were expressed as mean ± SD or number (%), as appropriate a The time from suturing the seromuscular layer of posterior duodenal wall and gastric wall to the seromuscular suture completed of the anterior wall of anastomotic stoma

Postoperative Follow-up Information
All the patients returned visit in the outpatient department when the 1st and 3th month after operation. All Patients exhibited a satisfactory appetite, and there was no discomfort symptom such as abdominal pain and bloating. The upper gastrointestinal imaging showed that the anastomosis was unobstructed as the contrast agent smoothly entered the duodenum (Fig. 4). Gastroscope examination 3 months after the operation showed that the anastomosis was well healed and there was no stenosis (Fig. 5).

Discussion
Totally laparoscopic gastrectomy has shown distinct advantages comparing to laparoscopic-assisted gastrectomy [4][5][6] . In totally laparoscopic distal gastrectomy, digestive tract reconstruction has been a key and difficult part of the surgery. At present, various anastomotic methods have their own advantages and disadvantages. For patients with lower gastric cancer, most of them underwent Delta-shaped anastomosis, Billroth II anastomosis or Roux-en-Y anastomosis by stapler [1,7,8] . The Billroth I anastomosis is considered to be more in line with the human physiology and anatomy, so it has been favored by surgeons. So far, triangle-shaped anastomosis or modified triangle-shaped anastomosis by stapler is the mostly chosen kind of Billroth I anastomosis [7,9] . Totally laparoscopic triangle-shaped anastomosis by stapler requires overlapping the remnant stomach wall and duodenum, theoretically wasting part of the remnant stomach wall and duodenal wall and increasing the anastomotic tension. At the same time, dissecting tumors located higher or near the gastric body is prone to cause insufficient margins, thus greatly limiting the indications for totally laparoscopic Billroth I anastomosis [10] . Billroth II anastomosis can lead to reflux gastritis due to bile reflux, which could increase the incidence of remnant gastric cancer [11] . As a result, it has fallen out of favor for digestive tract reconstruction. Roux-en-Y anastomosis requires two anastomoses, and thus increases the number of intestinal stumps, which requires rather complicated steps. Also, like Billroth II anastomosis, Roux-en-Y anastomosis does not highly conform to the human physiology and anatomy [8,12] .

Safety And Feasibility
In our study, the mean duration of the operation was 154.51 ± 33.37 min and the mean time to complete the anastomosis was26.88 ± 5.11 min (Fig. 3). The amount of intraoperative bleeding was 66.34 ± 48.81 mL. There was no significant statistical difference in terms of operation time between anastomosis by stapler vs by hand [13] . Lymph node dissection was performed strictly according to the standard radical (D2) lymphadenectomy. The number of lymph nodes was 32.76 ± 13.16, of which the number of positive ones was 2.39 ± 4.06, accounting for 7.47%. The number of dissected lymph nodes was much more than that required by Japanese Classification of Gastric Carcinoma. The pathological examination of the proximal and distal margins of the specimens was negative, also, tumor-free distance of both proximal and distal margins is within the required range (Table 2).
Therefore, radical dissection could be guaranteed. Gastrointestinal imaging showed normal gastric emptying on the 6th postoperative day (Fig. 4). Only 1 patient developed pulmonary infection and received anti-infective treatment. One patient developed anastomotic leakage, received unobstructed surgical drainage and placed into nasoenteral nutrition tube for enteral nutrition support, and recovered 2 weeks later. There was two cases of gastroparesis who recovered on the 18th and 25th day after operation respectively by gastrointestinal decompression and nasoenteral nutrition tube through gastroscope for enteral nutrition. All the above patients recovered after conservative nonoperative treatment. All 41 patients recovered well and were follow up after surgery, no serious complications or perioperative death occurred The patient returned visit at the 3th months after surgery and gastroscopic results showed unobstructed anastomosis and smooth mucosa (Fig. 5). In addition, total hospitalization cost for this group of patients was (70804.00 ± 14282.05)RMB yuan, which was significantly lower than that reported by Shinohara T, Wang Y and others [14,15] . The results above indicate that totally laparoscopic hand-sewn Billroth I anastomosis is a safe and feasible method for digestive tract reconstruction.

Advantages
Totally laparoscopic hand-sewn Billroth I anastomosis has the following advantages: (1) It conforms to human anatomy and physiology. Totally laparoscopic hand-sewn Billroth I anastomosis manages to save the continuity of digestive tract and the feedback mechanism of autocrine and paracrine, which are more consistent with the normal physiological structure. Therefore, reflux gastritis caused by bile reflux can be avoided [3] . (2) A clear field of vision during totally laparoscopic hand-sewn Billroth I anastomosis is guaranteed. Compared with other anastomotic methods, this one is limited to the right upper abdomen. There is no need to frequently change the field of vision, which can decrease the difficulty of assistant coordination. (3) The number of anastomoses is decreased, which reduces complications such as anastomotic bleeding and leakage. Under skilled cooperation of teamwork, time of total operation and time of anastomosis by hand were not significantly longer than those by staplers [13] . Besides, the operation time was gradually reduced with the extension of the learning curve (Fig. 4). (4) The hand-sewn anastomosis is relatively smooth comparing to anastomosis by stapler which is prone to have overlapped corners or "Dog ear"causing higher risk of anastomotic leakage as well as adhesion. (5) Fully ensure the resection range and reduce anastomotic tension.
Hand-sewn Billroth I anastomosis is a standard end-to-end anastomosis, which could reserve the overlapped gastroduodenal wall wasted in triangle-shaped anastomosis by stapler. (6) Mesenteric hiatal hernia and Peterson hernia can be avoided in hand-sewn Billroth I anastomosis. (7) Decreased complications such as adhesive ileus. This procedure is limited to the right upper abdomen, which could reduce potential mechanical stimulation and mucosal damage to jejunum therefore decreasing the incidence rate of postoperative intestinal adhesion.

Difficulties And Countermeasures
Although totally laparoscopic hand-sewn Billroth I anastomosis has many advantages, it is still a very difficult technique for some surgery teams that newly start practicing totally laparoscopic hand-sewn Billroth I anastomosis. For example, it has been previously reported that intra-abdominal anastomosis can increase the incidence rate of abdominal infection [16] . In our study, bulldog clamp was used to block the gastric and duodenal stumps respectively to avoid intestinal fluid leakage, and not removed until full-thickness anastomosis was completed. Also, the surgical team needs to discuss in advance about the specific anastomosis steps in great details to achieve perfect cooperation [17] .

Consent for publication
All authors agreed with the content and all gave explicit consent for publication.

Availability of data and materials
All data generated or analyzed during this study are included in this published article and its supplementary information files.

Competing interests
There is no conflict of interest in this research.    Upper gastrointestinal imaging 6 days and 1 month after operation. A X-ray performed 6 days after the operation shows that the anastomotic stoma was unobstructed and there was no anastomotic leakage. B X-ray imaging performed 1 month after the operation.

Supplementary Files
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