Stomach resection with intraoperative fluoroscopy in laparoscopic distal gastrectomy for early gastric cancer.

BACKGROUND: In Japan, laparoscopic distal gastrectomy (LDG) is common for early gastric cancer. Formerly, we used to verify the location of the marking clip to decide the proximal incisional line with our hand, through a small epigastric incision. In 2015, we introduced intracorporeal reconstruction and started to decide the incisional line using intraoperative fluoroscopy. Herein, we aimed to evaluate the efficacy and safety of intraoperative fluoroscopy in LDG. PATIENTS AND METHODS:: A total of 19 patients were included in this retrospective observational study. On the day before operation, we endoscopically clipped several points located 2 cm proximal to the tumour edge to cover about half of the tumour. After lymph node dissection, we incised the stomach with an endoscopic linear stapling device, including the previously placed clips, guided by intraoperative fluoroscopy. Reconstruction was performed in all patients who underwent Billroth I and Roux-en-Y procedures.
RESULTS: No complications were observed during pre-operative endoscopic clipping or intraoperatively. On pathological examination, all resected specimens had negative margins, and the mean distance from the tumour edge was 28.5 ± 16.5 (13-60) mm.
CONCLUSION: Stomach resection with intraoperative fluoroscopic guidance was safe and effective.

INTRODUCTION

Recently, laparoscopic surgery for early gastric cancer is increasingly being performed[1] and shows good oncological outcome.[2] Compared with open surgery, laparoscopic surgery provides a better quality of life.[3] As for distal gastrectomy, the trend is changing from laparoscopy-assisted distal gastrectomy (LADG) to laparoscopic distal gastrectomy (LDG), in which gastrointestinal anastomosis is performed intracorporeally. LDG is less invasive than LADG.[45] Delineation of the proximal incision line is the key for distal gastrectomy. In the era of LADG, direct contact with the clips placed pre-operatively is possible through a small epigastric wound. In LDG, direct contact with the clips is not possible because of intra-abdominal reconstruction. Although several methods for identification of the tumour have been suggested, it is unclear which method is the best. This study aimed to evaluate the efficacy and safety of intraoperative fluoroscopy to identify the clips placed pre-operatively to delineate the proximal resection line during LDG.

PATIENTS AND METHODS

From January 2015 to December 2016, retrospective review of 19 patients who underwent LDG under intraoperative fluoroscopic guidance was performed. The inclusion criterion was tumour stage T1N0M0. Patients with advanced gastric cancer, lymph node metastasis, and those requiring additional resection post-endoscopic submucosal dissections were excluded.

The institutional ethics committee approved this study, allowing patients to opt-out instead of providing informed consent.

Pre-operative marking

On the day before operation, several clips (HX-600-090 L, Olympus, Tokyo) were endoscopically placed at 2 cm from the tumour edge to cover its proximal half [Figure 1].

Figure 1

Endoscopic pre-operative clipping

Operative details

Under general and epidural anaesthesia, LDG was performed with 5 ports (two 12-mm trocars and three 5-mm trocars). After lymph node dissection and incision of the duodenum, the C-arm (OEC 9900 Elite, GE Healthcare UK Ltd, Little Chalfont, Buckinghamshire, England) was positioned as shown in Figure 2. Surgeons, nurses, and anaesthesiologists were shielded with protectors. The proximal gastric incision line was marked with 1% Crystal violet on the serosal surface of the stomach, with the aid of clips under fluoroscopic guidance, followed by incision with a linear stapling device (Endo GIA™ 60 mm Reload with Tri-Staple™ Technology, Medtronic plc, Dublin, Ireland), using 2 or 3 cartridges from the left lower port [Figures 3 and 4]. After removal of the stomach through the small umbilical incision and confirming that all clips were included in the resected stomach [Figure 5], intracorporeal gastrointestinal reconstruction was performed. Billroth I (B-I) or Roux-en-Y (R-Y) method was selected, depending on the size of the remnant stomach. As for R-Y reconstruction, jejunojejunostomy was performed extracorporeally through the small umbilical incision. D1+ lymph node dissection was done, according to the Japanese guideline for gastric cancer.[6]

Figure 2

C-arm setting during operation

Figure 3

Stomach resection with linear stapling device

Figure 4

Resection under intraoperative fluoroscopy

Figure 5

Resected specimen with clips

Statistics

All statistical analyses were performed with EZR (Saitama Medical Center, Jichi Medical University, Japan, version 1.32), which is a graphical interface for R, version 3.2.2 (The R Foundation for Statistical Computing, Vienna, Austria). For continuous variables, we calculated descriptive statistics, including the number of patients, mean and standard deviation, minimum, maximum and median. Student's t-test and one-way analysis of variance were used for comparing means. A two-tailed P = 0.05 was considered statistically significant.

RESULTS

The mean age of the 19 patients (8 men and 11 women) was 68.2 ± 13 years [Table 1]. No complications were observed during pre-operative clipping. The mean operative time (11 B-I and 8 R-Y) was 275.5 ± 38.5 min, and the mean blood loss was 34.4 ± 38.4 ml. Mean length of hospital stay was 12.8 ± 2.6 days. Complications included wound infection (n = 1), paralytic ileus (n = 1) and delayed gastric empting (n = 1), which were managed conservatively.

Table 1

Demographic and clinical characteristics of patients

Although the indication for operation was T1N0M0, more advanced cases (pT2: n = 3, pT3: n = 2, and pT4: n = 1) were seen. The mean longest-diameter of the tumour was 37.8 ± 25.4 mm. The margins of all resected specimens were negative, and the mean proximal-margin length was 28.5 ± 16.5 (range: 13 − 60) mm.

Tumour size [≧40 mm, ≦30 mm, Figure 6], differentiation [differentiated, undifferentiated: Figure 7], and depth [pT1a, pT1b, ≦ pT2: Figure 8] were not associated with tumour margins, respectively.

Figure 6

Size and margin

Figure 7

Differentiation and margin

Figure 8

Depth and margin

DISCUSSION

The trend in surgery for early gastric cancer is shifting from LADG to LDG.[7] We had been performing LADG since 2008. We manually check for the correct location of clips around a tumour through a small epigastric incision. Since 2015, we have been performing LDG, which comprises intracorporeal gastrointestinal reconstruction. At first, we used Chinese ink that was endoscopically injected pre-operatively to delineate the proximal incision line. However, the ink was sometimes invisible or too widely distributed. Then, we surmised that intraoperative fluoroscopy might be useful to identify clips that were endoscopically placed pre-operatively to obtain an oncological safety margin. In this study, all resected specimens had negative margins. In the Japanese guidelines for gastric cancer, a margin >2 cm for T1 cancer is recommended. In this study, we placed the clips 2 cm from the proximal edge pre-operatively. The mean pathological margin was 28.5 mm, which was considered adequate.

A negative margin is important in distal gastrectomy because it affects local recurrence and prognosis.[89] Many methods of identifying a tumour have been reported, including methylene blue injection,[10] indigo carmine injection,[11] intraoperative laparoscopic ultrasonography,[12] intraoperative portable radiography,[13] and intraoperative endoscopy.[1415] Intraoperative endoscopic determination of a resection line with adequate margin may sometimes be difficult for the surgeon. We believe it is better for the endoscopist to determine the incision line in a properly equipped room, especially for undifferentiated early cancers. Intraoperative ultrasonography requires practice, and intraoperative endoscopy requires adequate space for instruments to be placed near the anaesthesiologist. Our method is simple and easy. Moreover, C-arms are usually used in operating rooms.

Study limitation

This was a retrospective observational study with a small sample size. An additional disadvantage of this method is radiation exposure. Unfortunately, this was not investigated in this study. The duration of radiation exposure was about 30 s, and the organ dosage was about 3 or 4 mGy. Surgeons, scrub nurses and anaesthesiologists were shielded with protectors. As for the patient, the field was limited around the stomach. We believe that this is not excessive exposure when obtaining a safe oncological margin, but further studies are needed.

In conclusion, intraoperative fluoroscopy with pre-operative clipping is simple, easy and effective and enables determination of the proper proximal resection line for LDG. Further, studies should be conducted to evaluate radiation exposure in comparison with other methods.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.