Tracers in Gastric Cancer Surgery

The treatment of gastric cancer mainly depends on radical gastrectomy. Determination of appropriate surgical margins and adequate lymph node (LN) resection are two major surgical steps that directly correlate with prognosis in gastric cancer. Due to the expanding use of minimally invasive procedures, it is no longer possible to locate tumors and LNs through touch. As an alternative, tracers have begun to enter the field due to their capacities for intraoperative visualization. Herein, we summarize the application of contemporary tracers in gastric cancer surgery, including isosulfan blue, methylene blue, patent blue, indocyanine green, carbon particles, and radioactive tracers. Their mechanisms, administration methods, detection efficiency, and challenges, as well as perspectives on them, are also outlined.

Laparoscopic Gastrectomy with ICG Guided D2 Lymph Node Dissection – A Case Report and Review of the Literature

Radical surgery for gastric cancer remains the only reliable therapeutic tool and cornerstone for definitive treatment. With improving resectability, patients are given a better opportunity for long-term survival. Indocyanine green (ICG) is able to define more precisely the boundaries of the tumor in early and advanced gastric cancer. In addition, it can noticeably improve lymph node dissection and reduce the risk of subsequent complications. In this paper we present our experience with laparoscopic gastrectomy together with a review of the available literature.

Intraoperative Tumor Identification During Laparoscopic Distal Gastrectomy: a Novel Fluorescent Clip Marking Versus Metal Clip Marking and Intraoperative Gastroscope

BACKGROUND

In complete laparoscopic distal gastrectomy, the gastric resection line is difficult to determine due to a lack of tactile sensation. The use of intraoperative gastroscopy and intraoperative radiography has been reported, but the burden on personnel and technical complexity present impediments. In our department, based on lesion extent determined with preoperative gastroscopy, a fluorescent clip is used to mark the oral side of the lesion, which is resected after confirmation with a fluorescent laparoscopic system. In this study, we investigated the efficacy of fluorescent clip marking (FCM) in achieving an accurate resection line and reducing the operative time.

METHODS

Fifty-six patients with gastric cancer who underwent complete laparoscopic distal gastrectomy from January 2018 to March 2021 were divided into two groups: the FCM group (n = 32) and the conventional metal clip marking and intraoperative gastroscopy (MCMG) group (n = 24). Short-term outcomes, including the resection margins, gastric resection time, and operative time, were compared and examined.

RESULTS

The fluorescent clips were visible in all cases, and all stumps were negative according to permanent preparations. The operative times for FCM and MCMG were 350 (216-533) vs. 373.5 (258-651) min, respectively, with no significant difference (p = 0.316), while the gastric resection times were 636.5 (321-2572) vs. 1457.5 (843-4973) s, respectively, and were significantly shorter in the FCM group (p < 0.0001).

CONCLUSIONS

FCM shortened the gastric resection time and could possibly shorten the operative time. FCM is feasible and safe and can potentially be used as a tumor-marking agent to determine accurate surgical resection lines.

CLINICAL TRIAL REGISTRATION

Examination of Gastric Cancer, Research Ethics Committee of the Kawaguchi Municipal Medical Centre (Saitama, Japan), approval number: 2019-33. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

Transpyloric optic navigation of tumor using a laparoscope during totally laparoscopic distal gastrectomy for gastric cancer

Purpose

Methods

Results

Conclusion

Regional Lymph Node Dissection as an Additional Treatment Option to Endoscopic Resection for Expanded Indications in Gastric Cancer: a Prospective Cohort Study

Purpose

Expanded indications for endoscopic submucosal dissection (ESD) in early gastric cancer (EGC) remain controversial due to the potential risk of undertreatment after adequate lymph node dissection (LND). Regional LND (RLND) is a novel technique used for limited lymphadenectomy to avoid gastrectomy. This study established the safety and effectiveness of RNLD as an additional treatment option after ESD for expanded indications.

Materials and Methods

A total of 69 patients who met the expanded indications for ESD were prospectively enrolled from 2014 to 2017. The tumors were localized using intraoperative esophagogastroduodenoscopy (EGD) before RLND. All patients underwent RLND first, followed by conventional radical gastrectomy with LND. The locations of the preoperative and intraoperative EGD were compared. Pathologic findings of the primary lesion and the RLND status were analyzed.

Results

The concordance rates of tumor location between the preoperative and intraoperative EGD were 79.7%, 76.8%, and 63.8% according to the longitudinal, circumferential, and regional locations, respectively. Of the 4 patients (5.7%) with metastatic LNs, 3 were pathologically classified as beyond the expanded indication for ESD and 1 had a single LN metastasis in the regional lymph node.

Conclusions

RLND is a safe additional option for the treatment of EGC in patients meeting expanded indications after ESD.

Application of Near-Infrared Fluorescence Imaging with Indocyanine Green in Totally Laparoscopic Distal Gastrectomy

Purpose

Recently, totally laparoscopic gastrectomy has been gradually accepted by surgeons worldwide for gastric cancer treatment. Complete dissection of the lymph nodes and the establishment of the surgical margin are the most important considerations for curative gastric cancer surgery. Previous studies have demonstrated that indocyanine green (ICG)-traced laparoscopic gastrectomy significantly improves the completeness of lymph node dissection. However, it remains difficult to identify the tumor location intraoperatively for gastric cancers that are staged ≤T3. Here, we investigated the feasibility of ICG fluorescence for lymph node mapping and tumor localization during totally laparoscopic distal gastrectomy.

Materials and Methods

Preoperative and perioperative data from consecutive patients with gastric cancer who underwent a totally laparoscopic distal gastrectomy were collected and analyzed. The patients were categorized into the ICG (n=61) or the non-ICG (n=75) group based on whether preoperative endoscopic mucosal ICG injection was performed.

Results

The ICG group had a shorter operation time and less intraoperative blood loss. Moreover, significantly more lymph nodes were harvested in the ICG group than the non-ICG group. No pathologically positive margin was found and there was no significant difference in either the proximal or distal surgical margins between the 2 groups.

Conclusions

Near-infrared fluorescence imaging with ICG can be successfully used in totally laparoscopic distal gastrectomy, and it contributes to both the completeness of D2 lymph node dissection and confirmation of the gastric transection line. Well-designed prospective randomized studies are needed in the future to fully validate our findings.

Detection of indocyanine green fluorescence to determine tumor location during laparoscopic gastrectomy for gastric cancer: Results of a prospective study

INTRODUCTION

In laparoscopic gastrectomy, a method to locate the margin of an early-stage cancerous lesion that is invisible from the serosal surface and impalpable during laparoscopic procedures is needed to determine an appropriate transection line. We conducted a prospective study to develop a new marking method using preoperative submucosal injection of indocyanine green (ICG).

METHODS

Patients undergoing laparoscopic gastrectomy for T1 gastric cancer were recruited. The first 11 patients comprised the learning set and the subsequent 18 patients the validation set. ICG was endoscopically injected in the submucosal layer of the stomach approximately 1 cm away from the tumor edge 1 or 3 days before surgery. The diameters of the visualized ICG were compared with those of a conventional marking method using India ink in 10 historical controls.

RESULTS

In the learning set, the optimal amount of ICG was determined to be 0.1 mL at a concentration of 0.5 mg/mL. In the validation set, the same procedure was repeated. No technical problems or adverse reactions related to ICG injection were observed. In all cases, ICG was successfully detected, and negative surgical margins were pathologically confirmed. The mean long diameter of the visualized ICG fluorescence measured at the mucosal surface of the stomach was significantly smaller in the current study than in the historical controls in whom India ink was used (21 vs 52 mm, P < 0.0001).

CONCLUSIONS

The preoperative submucosal ICG marking was safely performed and successfully detected without excessive blurring during laparoscopic gastrectomy.

Role of preoperative endoscopic clipping in laparoscopic distal gastrectomy for early gastric cancer

In this study, we evaluate the usefulness of preoperative endoscopic clipping for early gastric cancer (EGC) localization in laparoscopic distal gastrectomy.We retrospectively screened all consecutive patients who underwent laparoscopic distal gastrectomy for EGC by 1 surgeon at Chungnam National University Hospital between January 2014 and December 2016. Patients who underwent combined surgery and patients who had tumors at the lower third of the stomach were excluded. Endoscopic clipping was performed prior to surgery by specialized endoscopists. During the operation, endoscopic metal clips were found using surgical devices, and laparoscopic vessel clips were attached on the presumed site; thereafter, intraoperative radiographs were obtained for confirmation.We analyzed a total of 196 patients; of them, 101 were classified into the clipping group (CG) and 95 into the non clipping group (NCG). The 2 groups were comparable regarding their demographic characteristics. The CG showed less additional resection (2 of 101 patients [2.0%] vs 9 of 95 patients [9.4%], P = .021) and better outcomes in terms of the operation time (P = .000), duration of hospital stay (P = .036), and postoperative atelectasis (P = .001) than the NCG.Preoperative endoscopic clipping was helpful in determining the exact resection margin in laparoscopic distal gastrectomy for EGC.

Tumor localization using radio-frequency identification clip marker: experimental results of an ex vivo porcine model

PURPOSE

With the widespread use of minimally invasive surgery, tumor detection is becoming more difficult. We present the experimental results of a radio-frequency identification (RFID) lesion detection system in an ex vivo porcine model.

METHODS

The efficacy and feasibility of a newly developed RFID lesion detection system were examined. It was applied to the stomach and colon of pigs weighing 40 kg. The RFID clip was attached to the upper and lower mucosal sides of the stomach. Colon specimens with thin and thick walls were used. The clipped sites were marked on the serosa by a pin. The longest distance from the pin the RFID tag could be detected was measured 25 times in each direction.

RESULTS

In the upper gastric wall, the RFID tag detection distance was 4.5 ± 0.9 mm, 5.6 ± 0.7 mm, 12.5 ± 0.7 mm, and 5.3 ± 0.5 mm in the four directions, respectively (right, left, upper, and lower). In the antrum, the RFID tag detection distance was 5.8 ± 0.7 mm, 6.9 ± 0.5 mm, 5.6 ± 0.5 mm, and 3.7 ± 0.5 mm in the four directions. In the thin colon, the RFID tag detection distance was 6.3 ± 0.5 mm, 5.0 ± 0.5 mm, 9.7 ± 0.7 mm, and 6.4 ± 0.4 mm in the four directions. In the thick colon, the RFID tag detection distance was 3.5 ± 0.8 mm, 6.6 ± 0.5 mm, 8.4 ± 0.6 mm, and 9.8 ± 0.5 mm in the four directions. The area of detection was smallest for the antrum (83.7 mm²) and similar for the other sites (150.6, 154.7 and 157.7 mm² for the upper body, thin colon, and thick colon, respectively).

CONCLUSIONS

The distance at which the RFID tag was detected was usually within 10 mm. These results indicate the feasibility of the clinical application of the add-on clip and RFID tag as a marker for identifying the location of various gastrointestinal tumors.

Preoperative endoscopic titanium clip placement facilitates intraoperative localization of early-stage esophageal cancer or severe dysplasia

Background

Accurate intraoperative localization of esophageal lesions is essential for successful surgical resection. We tested whether preoperative endoscopic placement of titanium clips could facilitate intraoperative localization of early-stage esophageal cancer or severe dysplasia.

Methods

A prospective randomized clinical trial was performed between May 2012 and July 2014. All enrolled patients received preoperative endoscopy and esophageal endoscopic ultrasound, as well as pathological study on the biopsy specimen, to confirm early stage esophageal cancer or severe dysplasia. One day before the surgical operation, patients in the experimental group received the preoperative endoscopic titanium labeling of esophageal lesions. Then, during the surgical operation, palpitation of titanium clips was used to localize the lesions in these patients. In patients in the control group, palpitation of nodules or esophageal wall mucosal thickening, together with the consideration of the results from preoperative endoscopic and ultrasound studies, was applied to estimate the location of the esophageal lesions. Study outcomes included the proportions of patients having successful intraoperative pre-resection lesion localization, post-esophagectomy lesion visualization, negative upper surgical margin, change of surgical approaches, and positive postoperative pathological diagnosis.

Results

A total of 27 patients were enrolled into the study, with 14 in the experimental group and 13 in the control group. Compared to the patients in the control group, a higher proportion of patients in the experimental group had statistically significant successful intraoperative esophageal lesion localization (100 versus 15.3% in the experimental versus control group).

Conclusions

Preoperative endoscopic titanium clip placement could facilitate intraoperative localization of early-stage esophageal cancer or severe dysplasia.

Trial registration

Current study was registered in Chinese Clinical Trial Registry and World Health Organization International Clinical Trials Registry Platform, ChiCTR-INR-17010949. Registered 22 March 2017, retrospectively registered.

Simple and reliable method for tumor localization during totally laparoscopic gastrectomy: intraoperative laparoscopic ultrasonography combined with tattooing

We have developed a new method to localize a tumor during totally laparoscopic gastrectomy that uses intraoperative laparoscopic ultrasonography combined with preoperative clipping and tattooing. One or 2 days before the surgery, endoscopic clipping was performed just proximal to the tumor, followed by tattooing with India ink at the clipping site. Examination by intraoperative laparoscopic ultrasonography was performed at the tattooed site to detect the clips. The resection line of the stomach was determined with use of the detected clips as a marker of the proximal margin of the tumor. This method was attempted in 14 patients who underwent totally laparoscopic gastrectomy, and the clips were successfully identified in all patients. The clips were visualized as several layers of a hyperechoic bar, which was termed a "ladder sign." The mean time from insertion of the laparoscopic probe to identification of the clips was 2 min. The ladder sign is an important finding in this method.