Accurate, safe, and rapid method of intraoperative tumor identification for totally laparoscopic distal gastrectomy: injection of mixed fluid of sodium hyaluronate and patent blue

Release of liposomally formulated near-infrared fluorescent probes included in giant cluster vesicles by ultrasound irradiation

Detection of tumors and regional lymph nodes during surgery has been proposed in the diagnosis of lymphatic metastasis and the surgical treatment of malignant diseases. Giant cluster vesicles (GCVs), including liposomally formulated indocyanine green (LP-ICG) derivatives, are a possible candidate for agents to realize the two contradictory properties, i.e., retention in tissue for lesion-marking and trace for sentinel lymph nodes (SLNs) identification. We attempted to release the LP-ICG derivatives from GCVs using ultrasound contrast agents (UCAs) under ultrasound irradiation. An absorption spectrophotometer quantitatively evaluated the amounts of released LP-ICG derivatives. As a result, we demonstrated that it depended on conditions for sound pressure, burst length, and number density of UCAs, and had a sound pressure threshold independent of burst length and number density of UCAs. The results will aid to determine appropriate conditions to maximize the released amount of LP-ICG derivatives while keeping safety.

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.

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.

Short- and long-term oncological outcomes of totally laparoscopic gastrectomy versus laparoscopy-assisted gastrectomy for clinical stage I gastric cancer

BACKGROUND

Totally laparoscopic gastrectomy (TLG), which involves a complete intracorporeal gastric transection and the creation of an anastomosis, has been gradually adopted. However, a potential limitation of intracorporeal transection is the lack of tactile feedback, and whether this limitation influences oncological outcomes is unclear. The aim of this study is to evaluate the short- and long-term oncological safety of TLG using endoscopy-guided intracorporeal gastric transection for clinical stage (cStage) I gastric cancer.

METHODS

A total of 1875 consecutive patients who underwent laparoscopic gastrectomy for cStage I gastric cancer between January 2007 and March 2015 were enrolled in this study. Marking clips were preoperatively placed and a transection line was determined by perceiving it tactually in laparoscopy-assisted gastrectomy (LAG) or endoscopically in TLG. After propensity score matching, 1366 patients (683 each for LAG and TLG groups) were selected to primarily test the non-inferiority of TLG to that of LAG for relapse-free survival (RFS).

RESULTS

In the propensity-matched population, the 5-year RFS rates of the LAG and TLG groups were 94.3% (95% confidence interval (CI) 92.2-95.8%), and 95.6% (95% CI 93.8-96.9%), respectively. The hazard ratio (TLG/LAG) was 0.77 (95% CI 0.48-1.24, P for non-inferiority < 0.01). There were no significant differences in the recurrence profiles. The incidence of the remnant of marking clips or tumor tissue did not differ (LAG: 1.0% vs. TLG: 1.9%, P = 0.177).

CONCLUSIONS

TLG using preoperative markings and intraoperative endoscopic guidance provides cStage I gastric cancer patients with comparable oncological outcomes to the conventional method.

Intraoperative gastroscopy to determine proximal resection margin during totally laparoscopic gastrectomy for patients with upper third gastric cancer

Background

In totally laparoscopic gastrectomy (TLG), it is usually difficult to determine the proximal margin. Therefore, the present study evaluated the usefulness of intraoperative gastroscopy for direct marking of the tumor proximal margin during TLG for cancer in the upper third of the stomach.

Methods

This retrospective cohort study included 52 patients with gastric cancer who underwent TLG from January 2018 to May 2020. The proximal margin of tumors was determined by intraoperative gastroscopic methods.

Results

Patients were divided into short (1 cm) and long (2 cm) groups according to the distance to the proximal margin of the tumor. Participants consisted of 41 males and 11 females with a median age of 63.5 years. Tumors involving the esophagogastric junction (EGJ) occurred in 27 patients. Siewert type II and III tumors were present in 42 and 10 patients, respectively. The median operative time was 244 min. The long group had a statistically significant lower frequency of positive margin than the short group (0% vs. 17.4%, P=0.033). Total gastrectomy was performed in 35 patients, and 17 patients received proximal gastrectomy. No complications associated with the procedure occurred in any patient.

Conclusions

Intraoperative endoscopic views for tumor proximal localization can be used effectively during TLG for patients with upper third gastric cancer. Our results indicate that a distance of ≥2 cm from the proximal resection margin to the tumor was necessary to achieve a negative resection margin. In the future, this may be used as an alternative to frozen section diagnosis.

Use of endoscopy to determine the resection margin during laparoscopic gastrectomy for cancer

Background

It can be difficult to determine the transection line during totally laparoscopic surgery for early gastric cancer owing to lack of tactile feedback. This retrospective cohort study aimed to assess the role of intraoperative endoscopy in determining the resection margin in totally laparoscopic gastrectomy.

Methods

Consecutive patients with histologically confirmed gastric cancer who underwent laparoscopic gastrectomy between March 2012 and July 2015 were eligible. Preoperative placement of marking clips and intraoperative endoscopy were performed to determine the resection margin. Frozen-section analyses were also performed to confirm the absence of cancer cells at the surgical margin. Success was defined as the proportion of specimens with all clips present and by the proportion of resections with a negative surgical margin following initial transection.

Results

Total laparoscopic gastrectomy with intraoperative endoscopy was performed in 522 patients; a total of 662 surgical margins were analysed. The overall success rate was 99·8 per cent (661 of 662 margins). The success rate of achieving a negative surgical margin during the initial transection was 98·9 per cent (550 of 556 margins).

Conclusion

Preoperative placement of marking clips and intraoperative endoscopy is helpful in the determination of a safe surgical margin in patients with gastric cancer who undergo laparoscopic gastrectomy.

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.

Three-dimensional fusion images combining CT gastrography and CT angiography for early gastric cancer: pilot experiences of preoperative simulation prior to totally laparoscopic gastrectomy

We herein report two cases of gastric cancer in which preoperative 3-D CT gastrography and CT angiography fusion images enabled totally laparoscopic gastrectomy. Case 1 involved a 60-year-old woman with a superficial depressed lesion on the greater curvature of the middle gastric body. Case 2 involved a 64-year-old woman with a superficial depressed lesion on the posterior wall of the upper gastric body. In both cases, 3-D fusion images were prepared from enhanced CT scans after the area near the lesions was clipped under preoperative gastroendoscopy. Based on the relative position between the clips and nearby vessels, a resection line was preoperatively determined in each case. Totally laparoscopic distal gastrectomy and totally laparoscopic proximal gastrectomy were performed in cases 1 and 2, respectively, with safe surgical margins. Three-dimensional fusion images can help in preoperative simulation of totally laparoscopic gastrectomy.

Development of a non-blurring, dual-imaging tissue marker for gastrointestinal tumor localization

BACKGROUND

Knowing the exact location of gastrointestinal tumors both preoperatively and intraoperatively is essential for planning and performing laparoscopic surgery. Different techniques have been introduced to ascertain tumor locations during surgery, but none of these are fully satisfactory at establishing the minimum margins for organ resection while retaining curability. A new, non-blurring tissue marker, detectable by both X-ray computed tomography (CT) and near-infrared (NIR) fluorescence laparoscopy, has been developed, and we here examine its utility using an animal model.

METHODS

Liposomes, comprised phospholipids and an NIR fluorescent dye (an indocyanine green derivative), and emulsions, consisting of phospholipids and oily radiographic contrast medium, were combined with polyglycerol-polyricinoleate to form giant cluster-like vesicles. This vesicular dispersion (300 μl) was administered into the porcine gastric submucosa using a gastroendoscope, and the detectability of the marker was examined using X-ray CT and NIR fluorescence laparoscopy.

RESULTS

One hour after the administration of the vesicular dispersion, X-ray CT identified four individual injection sites, each at a 1-cm radius of a metal hemostasis clip. NIR fluorescence laparoscopy detected individual fluorescent spots 18 hours after the administration of the vesicular dispersion.

CONCLUSION

We anticipate that this newly developed tissue marker will contribute to the preoperative simulation of laparoscopic gastrointestinal cancer surgery and its intraoperative navigation.