Intraoperative portable abdominal radiograph for tumor localization: a simple and accurate method for laparoscopic gastrectomy

Development and evaluation of RFID-integrated endoscopic clips for laparoscopic surgery marking

BACKGROUND

As advancements in surgical instruments and techniques continue to evolve, minimally invasive surgery has become increasingly preferred as a means of reducing patient pain and recovery time. However, one major challenge in performing minimally invasive surgery for early gastrointestinal cancer is accurately identifying the location of the lesion. This is particularly difficult when the lesion is confined to the lumen of the intestine and cannot be visually confirmed from the outside during surgery. In such cases, surgeons must rely on CT or endoscopic imaging to locate the lesion. However, if the lesion is difficult to identify with these images or if the surgeon has less experience, it can be challenging to determine its precise location. This can result in an excessive resection margin, deviating from the goal of minimally invasive surgery. To address this challenge, researchers have been studying the development of a marker for identifying the lesion using a radio-frequency identification (RFID) system. One proposed method for clinical application of this detection system is to attach an RFID tag to an endoscopic hemostatic clip and fix it to the intended position, providing a stable marker for the inner wall of the organ. This approach has the potential to improve the accuracy and effectiveness of minimally invasive surgery for early gastrointestinal cancer.

METHODS

In the development of a marker for identifying gastrointestinal lesions using a radio-frequency identification (RFID) system, the shape of the clip and suitable materials for attaching the RFID tag were determined through finite element method (FEM) analysis. A prototype of the clip was then fabricated and ex-vivo experiments were conducted using porcine intestine to evaluate the stability of the clip in relation to its position. To further evaluate the performance of the RFID-integrated clip in vivo, the clip was placed in the gastric wall of the stomach of anesthetized porcine using an endoscopic instrument. The clip was then detected using a RFID detector designed for laparoscopic approach. And later, the accuracy of detection was confirmed by incising the lesion.

RESULTS

The design and fabrication of a clip with varying thicknesses using STS316 and STS304 stainless steel were accomplished using the results of finite element method analysis. The stability of the clip was evaluated through ex-vivo experiments, showing it to be a viable option. In-vivo experiments were performed on anesthetized porcine, in which the RFID-integrated clip was placed in the gastric wall and detected using a custom-made RFID detector. The resection margin, measured at about 30 mm from the detector position, was accomplished with low error. These findings indicate the feasibility and efficacy of using an RFID-integrated clip as a marker in minimally invasive surgery for the identification of gastrointestinal lesions.

CONCLUSIONS

The study evaluated the feasibility of using stainless steel clips for lesion detection in endoscopic surgery using computer-aided engineering analysis and ex-vivo experimentation. Results showed that STS304 was suitable for use while STS316L was not. The ex-vivo experiments revealed that the clip holding force and tissue retention length varied depending on the location of attachment. In-vivo experiments confirmed the accuracy and usefulness of the RFID lesion detection system. However, challenges remain for its use in clinical field, such as ensuring the stability of the clip and the safe attachment of the RFID tag, which requires further research for commercialization.

Clinical strategies for securing negative proximal margin in early gastric cancer

Securing an appropriate proximal resection margin (PRM) is crucial for oncological safety in treating gastric cancer. This study investigated the clinicopathological characteristics of patients with incomplete PRM length of <2 cm in early gastric cancer. Clinicopathological data of 1,493 patients who underwent subtotal gastrectomy for early gastric cancer in 2012 to 2021 were retrospectively reviewed. Patients were divided into the PRM length of <2 cm and ≥2 cm groups based on pathological results. Univariate and multivariate analyses evaluated factors for incomplete PRM length. Factors related to patients with a relative PRM positive were also analyzed. The proportion of patients with a PRM length of <2 cm was 17.9% (267/1,493). Multivariate regression analysis revealed that age <50, preoperative endoscopic size of ≥3 cm, size discrepancy of ≥2 cm, and midbody tumor with a lesser curvature significantly contributed to the PRM length of <2 cm. Twenty-four patients had a relative PRM positive (24/1493, 1.6%). An incomplete PRM was the only risk factor for a positive relative PRM. Surgical treatment for early gastric cancer requires an accurate preoperative endoscopic tumor size and location evaluation. A more aggressive resection is recommended for patients with age <50, preoperative endoscopic size of ≥3 cm, size discrepancy of ≥2 cm, and midbody tumor with a lesser curvature.

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.

Experimental Study on Gastric Labeling by Magnetic Detector Combined With Magnetic Bead

OBJECTIVE

Preoperative labeling of gastric cancer is an important means to determine the surgical margin. At present, there are many commonly used labeling methods. However, which is more accurate and has fewer complications remains to be studied. Through animal experiments, this study explored the feasibility, accuracy, and safety of a magnetic detector combined with magnetic beads for the preoperative labeling of gastric cancer.

METHODS

A total of 10 beagle dogs were included in the study. Each dog was randomly labeled with magnetic beads in the gastric body and antrum. After labeling, the magnetic detector was used to explore the gastric serosa surface, and the positioning titanium clip was released at the detected magnetic bead. The main monitoring index was to measure the distance between the labeled magnetic beads and the positioning titanium clamped. The secondary indexes were detection time, magnetic induction intensity, magnetic bead shedding rate, mucosal injury rate, bleeding, and leukocyte and C-reactive protein levels before and 24 hours after the operation.

RESULTS

All 10 beagle dogs completed the marking and exploration successfully. The average distance between the magnetic beads and the positioning titanium clip in 20 cases was 5.90±2.36 mm. The average detection time was 1.60±0.69 min, and the average magnetic induction intensity was 3.76±1.11 mT. No magnetic beads were found to fall off, 1 case had a mild mucosal injury, and 2 cases had a small amount of bleeding when releasing the positioning titanium clip. The white blood cells before and 24 hours after the operation were 7.43±0.94(×10 9 /L) versus 7.79±0.67(×10 9 /L) ( P =0.34). The C-reactive protein before and 24 hours after the operation were 5.24±0.97 µg/mL versus 5.95±1.02 µg/mL ( P =0.13).

CONCLUSION

A magnetic detector combined with magnetic beads for gastric cancer labeling is feasible, accurate, and safe. It is expected to be further applied in the clinic.

Preoperative indocyanine green fluorescence injection to accurately determine a proximal margin during robotic distal gastrectomy

INTRODUCTION

Adequate surgical margins following gastrectomy for gastric cancer are required. In addition, a method for accurately detecting tumor location without palpation is needed during robotic surgery. Although several methods have been reported, most of these either lack accuracy or require increased time and effort during intraoperative detection. Herein, we introduce a new method for detecting tumor location using preoperative indocyanine green (ICG) marking and the built-in ICG detection system of the da Vinci Xi Surgical System in robotic gastrectomy to determine appropriate surgical margins.

MATERIALS AND SURGICAL TECHNIQUE

We used this method to determine the resection line in six patients who underwent robotic distal gastrectomy for clinical T1 gastric cancer. One to three days before surgery, ICG was diluted to 1.0 mg/mL, and 0.1 mL of this diluted ICG solution was endoscopically injected at one site into the submucosal layer of the stomach, 1 cm proximal to the tumor edge. Gastrectomy was performed using the da Vinci Xi surgical platform, equipped with a near-infrared fluorescence imaging system (Firefly®). The diameter of the fluorescent signal during gastrectomy was estimated to be approximately 2 cm. The resection line was determined on the outer edge of the fluorescent signal, which ensured a tumor-free margin of ≥2 cm. Fluorescent signals were successfully observed in all cases. Moreover, the required 2-cm surgical margin was achieved in all cases.

DISCUSSION

We could successfully determine proximal margins using preoperative ICG injection marking during robotic distal gastrectomy for gastric cancer.

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.

Securing Resection Margin Using Indocyanine Green Diffusion Range on Gastric Wall during NIR Fluorescence-Guided Surgery in Early Gastric Cancer Patients

Near-infrared (NIR) fluorescence lymphography-guided minimally invasive gastrectomy using indocyanine green (ICG) is employed to visualize draining lymphatic vessels and lymph nodes. Endoscopically injected ICG spreads along the gastric wall and emits fluorescence from the serosal surface of the stomach. We aimed to assess the efficacy of ICG diffusion in securing the resection margin. We retrospectively analyzed 503 patients with early gastric cancer located in the body of the stomach who underwent fluorescence lymphography-guided gastrectomy from 2018 to 2021. One day before surgery, ICG was endoscopically injected into four points of the submucosal layer peritumorally. We measured the extent of resection and the resection line based on the ICG diffusion area from the specimen using NIR imaging. The mean area of the ICG diffusion was 82.7 × 75.3 and 86.7 × 80.2 mm2 on the mucosal and serosal sides, respectively. After subtotal gastrectomy, the length of the proximal resection margin was 38.1 ± 20.1, 33.4 ± 22.2, and 28.7 ± 17.2 mm in gastroduodenostomy, loop gastrojejunostomy, and Roux-en-Y gastrojejunostomy, respectively. The ICG diffusion area along the gastric wall secured a resection margin of >28 mm. The ICG diffusion range can be used as a simple and easy method for determining the resection margin during gastrectomy using NIR imaging.

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

Clinical Significance of Intra-operative Gastroscopy for Tumor Localization in Totally Laparoscopic Partial Gastrectomy

BACKGROUND

Tumor localization during totally laparoscopic gastrectomy is challenging owing to the invisibility of tumors on the serosal surface. We aimed to evaluate the clinical significance of intra-operative gastroscopy in totally laparoscopic partial gastrectomy.

METHODS

We reviewed 1084 gastric cancer patients who underwent either intra- or extracorporeal partial gastrectomy between 2014 and 2018. The intracorporeal group with intra-operative gastroscopy (intra-operative gastroscopy group, n = 187), the intracorporeal group without intra-operative gastroscopy (non-intra-operative gastroscopy group, n = 267), and the extracorporeal group (n = 630) were evaluated for the adequacy of surgical resection margins. We assessed whether total gastrectomy could be avoided according to the performance of intra-operative gastroscopy if the tumor was located within 3-5 cm away from the gastroesophageal junction.

RESULTS

The proximal margin positivity was lesser in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (0% versus 2.2%; P = 0.045) but similar to that in the extracorporeal group (0% versus 0.6%; P = 0.579). The number of cases with proximal resection margins < 1 cm was lower in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (3.7% versus 9.4%; P = 0.025) but comparable with that in the extracorporeal group (3.7% versus 4.1%; P = 0.815). Among 94 patients with lesions located within 3-5 cm apart from the gastroesophageal junction, the intra-operative gastroscopy group (n = 47) had fewer patients who underwent total gastrectomy than the non-intra-operative gastroscopy group (n = 47) (12.8% versus 44.7%; P = 0.001). Intra-operative gastroscopy was the only independent factor that prevented total gastrectomy (P = 0.001).

CONCLUSION

Intra-operative gastroscopy can provide margin safety during intracorporeal partial gastrectomy, avoiding unnecessary total gastrectomy.

Intraoperative Tumor Localization of Early Gastric Cancers

Recently, endoscopic screening systems have enabled the diagnosis of gastric cancer in the early stages. Early gastric cancer (EGC) is typically characterized by a shallow invasion depth and small size, which can hinder localization of EGC tumors during laparoscopic surgery. Here, we review nine recently reported tumor localization methods for the laparoscopic resection of EGCs. Preoperative dye or blood tattooing has the disadvantage of spreading. Preoperative 3-dimensional computed tomography reconstruction is not performed in real time during laparoscopic gastrectomy. Thus, they are considered to have a low accuracy. Intraoperative portable abdominal radiography and intraoperative laparoscopic ultrasonography methods can provide real-time feedback, but these methods require expertise, and it can be difficult to define the clips in some gastric regions. Despite a few limitations, intraoperative gastrofibroscopy provides real-time feedback with high accuracy. The detection system using an endoscopic magnetic marking clip, fluorescent clip, and radio-frequency identification detection system clip is considered highly accurate and provides real-time feedback; we expect a commercial version of this setup to be available in the near future. However, there is not yet an easy method for accurate real-time detection. We hope that improved devices will soon be developed and used in clinical settings.

Wireless Light-emitting Marker Using Magnetic Field Resonance for Laparoscopic Gastrointestinal Surgery

BACKGROUND

In laparoscopic gastrointestinal surgery, the location of the tumor is identified mainly with marking methods, such as ink tattooing and intraoperative gastrointestinal endoscopy and marking with a metal clip followed by confirmation with intraoperative x-ray fluoroscopy. Each method has disadvantages, such as complexity, instability of ink sticks, and radiation exposure. Thus, a simple and less-invasive marking method is needed.

METHODS

We developed a wireless light-emitting marker with a miniature light-emitting diode that uses a magnetic field resonance mechanism. It emits 4 individual colors-red, blue, green, and white. We confirmed the usefulness of this marker system in ex vivo and in vivo animal experiments.

RESULTS

In the ex vivo experiment in porcine intestines, use of the wireless marker was successful, as each color of emitted light was recognized from outside the intestine. In the live animal experiment, it was confirmed that the light emitted by the marker system was visible in the porcine intestinal tract during laparoscopic surgery. The light emitted by the wireless marker in the intestinal tract was confirmed with a laparoscope in a simulated animal surgery.

CONCLUSION

We have developed an innovative, radiation-free and reliable light-emitting marker system that uses a magnetic field resonance mechanism that emits four colors of light during laparoscopic surgery.

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.

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.

Fluorescent Lymphography-Guided Lymphadenectomy During Robotic Radical Gastrectomy for Gastric Cancer

Importance

Fluorescent imaging with indocyanine green can be used to visualize lymphatics. Peritumoral injection of indocyanine green may allow for visualization of every draining lymph node from a primary lesion on near-infrared imaging.

Objectives

To evaluate the role of fluorescent lymphography using near-infrared imaging as an intraoperative tool for achieving complete lymph node dissection and compare the number of lymph nodes retrieved with the use of near-infrared imaging and the number of lymph nodes retrieved without the use of near-infrared imaging.

Design, Setting, and Participants

This prospective single-arm study was conducted among 40 patients who underwent robotic gastrectomy between August 30, 2013, and July 21, 2014, at a single-center, tertiary referral teaching hospital. After propensity score matching, the results of these 40 patients were compared with the results of 40 historical control patients who underwent robotic gastrectomy without indocyanine green injection between January 1, 2012, and August 31, 2013. Statistical analysis was performed from January 1, 2015, to July 31, 2016.

Interventions

Robotic gastrectomy with systemic lymphadenectomy and retrieval of lymph nodes under near-infrared imaging after peritumoral injection of indocyanine green to the submucosal layer 1 day before surgery.

Main Outcomes and Measures

The primary outcome was the number of retrieved lymph nodes in each nodal station.

Results

Among the 40 patients in the study (19 women and 21 men; mean [SD] age, 52.2 [11.7] years), no complications related to indocyanine green injection or near-infrared imaging were observed. On completion of the lymphadenectomy, the absence of fluorescent lymph nodes in the dissected area was confirmed. A mean (SD) total of 23.9 (9.0) fluorescent lymph nodes were recorded among a mean (SD) total of 48.9 (14.6) overall lymph nodes retrieved. The mean number of overall lymph nodes retrieved was larger in the near-infrared group than in the historical controls (48.9 vs 35.2; P < .001), with a significantly greater number of lymph nodes retrieved at stations 2, 6, 7, 8, and 9. In the near-infrared group, 5 patients exhibited lymph node metastases, and all metastatic lymph nodes were fluorescent.

Conclusions and Relevance

This study's findings suggest that fluorescent lymphography may be useful intraoperatively for identifying and retrieving all necessary lymph nodes for a complete and thorough lymphadenectomy.

Laparoscopic Partial Sleeve Duodenectomy for the Infra-Ampullary Gastrointestinal Stromal Tumors of the Duodenum

BACKGROUND

Although organ-preserving operations are regarded as effective strategies for duodenal gastrointestinal stromal tumors (GISTs), laparoscopic partial sleeve duodenectomy (lap PSD) has not been fully evaluated. The aims of this study were to evaluate the effectiveness and technical feasibility of lap PSD.

STUDY DESIGN

Between January 2011 and March 2016, we reviewed 13 patients who underwent laparoscopic approach among 22 patients who underwent PSD. PSD for the infra-ampullary lesions was defined as infra-ampullary duodenal resection including the first portion of the jejunum. After resection, all patients underwent reconstruction via side-to-side duodenojejunostomy.

RESULTS

The total mean operation time was 273 min (range 160-346 min), and estimated mean blood loss was 80 ml (range scanty-200 ml). One patient was converted to open laparotomy because of mesocolonic tumor involvement. The median postoperative hospital stay was 10.5 days (range 4-36 days). There were no postoperative mortalities. Postoperative complications included 2 instances of delayed gastric emptying (DGE), 1 duodenojejunostomy stricture, and 2 intestinal obstructions. No patient was treated with adjuvant therapy. One patient experienced hepatic metastasis 28 months after surgery during a mean follow-up period of 48.6 months.

CONCLUSION

Lap PSD might be an oncologically effective strategy for duodenal GIST, and the laparoscopic approach is a technically feasible and appealing surgical modality in terms of safety and perioperative results. However, DGE and anastomosis strictures are concerns for postoperative complications, which need to be further investigated.

Laparoscopic Proximal Gastrectomy Maintains Body Weight and Skeletal Muscle Better Than Total Gastrectomy

BACKGROUND

Laparoscopic proximal gastrectomy (LPG) is performed as a function-preserving surgery for patients with early proximal gastric malignant tumors; however, whether LPG has advantages postoperatively compared with laparoscopic total gastrectomy (LTG) is debatable, especially with regard to nutritional outcomes.

METHODS

We evaluated 20 patients who underwent LTG and 10 patients who underwent LPG with double tract reconstruction (LPG-DT) who were diagnosed preoperatively with T1a or T1b N0 Stage IA gastric cancer in our department in the same time period. The statistical relevance of complications, surgical maneuvers, clinical factors and changes in weight, skeletal muscle index (SMI) and serum albumin levels after surgery was compared between the LPG-DT group and the LTG group.

RESULTS

No differences between groups were observed in patient demographics, operation time, blood loss, complications, number of dissected lymph nodes and pathological stage. The body weight reduction rate was significantly lower in the LPG-DT group compared with the LTG group at 6 months (5.7 vs. 14.9%, respectively; p = 0.0045) and 1 year after surgery (9.6 vs. 17.9%, respectively; p = 0.0042). The SMI reduction rate of the LPG-DT group in the first postoperative year was significantly lower than that of the LTG group (9.3 vs. 18.3%, respectively; p = 0.0057).

CONCLUSIONS

Patients with early gastric cancer who underwent LPG-DT had acceptable morbidity and mortality, similar to those who underwent LTG. Body weight and SMI reduction rates were lower in the LPG-DT group than in the LTG group. Thus, LPG-DT is an appropriate procedure for patients with clinical Stage IA proximal gastric cancer.

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.

Real-time detection system for tumor localization during minimally invasive surgery for gastric and colon cancer removal: In vivo feasibility study in a swine model

BACKGROUND AND OBJECTIVES

During minimally invasive surgery (MIS), it is impossible to directly detect marked clips around tumors via palpation. Therefore, we developed a novel method and device using Radio Frequency IDentification (RFID) technology to detect the position of clips during minimally invasive gastrectomy or colectomy.

METHODS

The feasibility of the RFID-based detection system was evaluated in an animal experiment consisting of seven swine. The primary outcome was to successfully detect the location of RFID clips in the stomach and colon. The secondary outcome measures were to detect time (time during the intracorporeal detection of the RFID clip), and accuracy (distance between the RFID clip and the detected site).

RESULTS

A total of 25 detection attempts (14 in the stomach and 11 in the colon) using the RFID antenna had a 100% success rate. The median detection time was 32.5 s (range, 15-119 s) for the stomach and 28.0 s (range, 8-87 s) for the colon. The median detection distance was 6.5 mm (range, 4-18 mm) for the stomach and 6.0 mm (range, 3-13 mm) for the colon.

CONCLUSIONS

We demonstrated favorable results for a RFID system that detects the position of gastric and colon tumors in real-time during MIS.

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.

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.

A Promising Method for Tumor Localization during Total Laparoscopic Distal Gastrectomy: Preoperative Endoscopic Clipping based on Negative Biopsy and Selective Intraoperative Radiography Findings

PURPOSE

Precise localization of tumors and creation of sufficient proximal resection margins are complicated processes during total laparoscopic distal gastrectomy (TLDG) for clinical T1/T2 gastric cancers. Various solutions to this problem have also yielded many disadvantages. In this study, we reviewed a preoperative endoscopic clipping method based on the results of negative biopsy and selective intraoperative radiography.

MATERIALS AND METHODS

A retrospective review of 345 consecutive patients who underwent TLDG and preoperative endoscopic clipping for tumor localization was conducted. During preoperative endoscopy, the endoscopists performed negative biopsies just 1-2 cm selectively above the tumor's upper limit. After confirming the biopsy results, endoscopic metal clips were applied just proximal to the negative biopsy site the day before surgery. Selective intraoperative tumor localization using portable abdominal radiography was performed only when we could not ensure a precise resection line.

RESULTS

Negative biopsy was performed in 244 patients. Larger tumor size (P=0.008) and more distally located tumors (P=0.052) were observed more frequently in the negative biopsy group than in the non-negative biopsy group. The non-negative biopsy group had significantly higher frequencies of differentiated tumor types than the negative biopsy group (P=0.003). Of the 244 patients who underwent negative biopsies, 6 had cancer cells in their biopsy specimens. We performed intraoperative radiography in 12 patients whose tumors had difficult-to-determine proximal margins. No tumors were found in the proximal resection margins of any patients.

CONCLUSIONS

Our tumor localization method is a promising and accurate method for securing a sufficient resection margin during TLDG.

Robotic gastrectomy for gastric cancer: Current evidence

The robotic system has gained wide acceptance in specialties such as urological and gynecological surgery. It has also been applied in the field of upper gastrointestinal surgery. Since the first implementation of the robotic system for the treatment of gastric adenocarcinoma, the procedure has been found to be safe and feasible. Although robotic gastrectomy does not meet our expectations and yield better results than laparoscopic gastrectomy, this procedure seems to provide several advantages over laparoscopy such as reduced blood loss, shorter learning curves and increased number of retrieved lymph nodes. However, as many case series, including a recent multicenter study, have revealed, higher cost and longer operation time are the major limitations of robotic gastrectomy. Furthermore, there are no results from well-designed randomized clinical trials comparing the two procedures. New procedures in much more technically demanding cases will test the genuine benefits of robotic 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.

A novel option for preoperative endoscopic marking with India ink in totally laparoscopic distal gastrectomy for gastric cancer: A useful technique considering the morphological characteristics of the stomach

In totally laparoscopic distal gastrectomy (TLDG) for gastric cancer, accurately determining the proximal resection line may be difficult. This is because identifying the lesion intracorporeally is impossible, due to the lack of tactile sense, and, in addition, unlike the intestine, the most proximal site of the lesion is often different from the main site due to the distorted shape of the stomach. The aim of this study was to introduce a novel method of preoperative endoscopic marking with India ink, taking into consideration the morphological characteristics of the stomach. Between July, 2013 and April, 2016, 20 patients who underwent TLDG were enrolled in this study. Within the 3 days preceding the operation, after identifying the most proximal site of the lesion on the overlooking image of an endoscope, India ink was injected into the spot on the oral side of this site. The stomach was transected along the proximal border of the marked area. In all cases, the marked sites were localized and clearly identified during the operation, and the proximal resection margins were found to be negative on postoperative pathological examination. The mean length of the proximal margin was 46.0±14.0 mm. In conclusion, this preoperative endoscopic marking method may be useful in TLDG for gastric cancer.

A comparison between two methods for tumor localization during totally laparoscopic distal gastrectomy in patients with gastric cancer

Purpose

The aim of this study was to compare two methods of tumor localization during totally laparoscopic distal gastrectomy (TLDG) in patients with gastric cancer.

Methods

From March 2014 to November 2014, patients in whom TLDG had been engaged for middle third gastric cancer enrolled in this study. The patients were allocated to either the radiography or endoscopy group based on the type of tumor localization technique. Clinicopathologic outcomes were compared between the 2 groups.

Results

The accrual was suspended in November 2014 when 39 patients had been enrolled because a failed localization happened in the radiography group. The radiography and endoscopy groups included 17 (43.6 %) and 22 patients (56.4 %), respectively. Mean length of the proximal resection margin did not differ between the radiography and endoscopy groups (4.0 ± 2.6 and 2.8 ± 1.2 cm, respectively; P = 0.077). Mean localization time was longer in the radiography group than in the endoscopy group (22.7 ± 11.4 and 6.9 ± 1.8 minutes, respectively, P < 0.001). There were no statistically significant differences in the incidence of severe complications between the 2 groups (5.9% and 4.5%, respectively, P = 0.851).

Conclusion

As an intraoperative tumor localization for TLDG, radiologic method was unsafe even though other comparable parameters were not different from that of endoscopy group. Moreover, intraoperative endoscopic localization may be advantageous because it is highly accurate and contributes to reducing operation time.

Intraoperative Gastroscopy for Tumor Localization in Laparoscopic Surgery for Gastric Adenocarcinoma

Determining resection margins for gastric cancer, which are not exposed to the serosal surface of the stomach, is the most important procedure during totally laparoscopic gastrectomy (TLG). The aim of this protocol is to introduce a procedure for intraoperative gastroscopy, in order to directly mark tumors during TLG for gastric cancer in the middle third of the stomach. Patients who were diagnosed with adenocarcinoma in the middle third of the stomach were enrolled in this case series. Before surgery, additional gastroscopy for tumor localization is not performed. Under general anesthesia, laparoscopic mobilization of the stomach is performed first. After the first portion of the duodenum is mobilized from the pancreas and clamped, the surgeon moves to the other side for the gastroscopic procedure. On the insertion of a gastroscope through the oral cavity into the stomach, 2 - 3 cc of indigo carmine is administered via an endoscopic injector into the gastric muscle layer at the proximal margin of the stomach. The location of stained serosa in the laparoscopic view is used to guide distal subtotal gastrectomy, however, total gastrectomy is performed if the tumor is too close to the esophagogastric junction. A specimen is sampled after distal gastrectomy to confirm sufficient length from resection margin to tumor before reconstruction. In our case series, all patients had tumor-free margins and required no additional resection. There was no morbidity related to the gastroscopic procedure, and the time required for the procedure has gradually decreased to about five minutes. Intraoperative gastroscopy for tumor localization is an accurate and tolerated method for gastric cancer patients undergoing totally laparoscopic distal gastrectomy.

Linear-shaped gastroduodenostomy (LSGD): safe and feasible technique of intracorporeal Billroth I anastomosis

BACKGROUND

Although delta-shaped gastroduodenostomy (DSGD) is used increasingly as an intracorporeal Billroth I anastomosis after distal gastrectomy, worries about anatomical distortion always exist in twisting stomach and making an oblique incision on duodenum. We developed a new method of intracorporeal gastroduodenostomy, the linear-shaped gastroduodenostomy (LSGD), in which anastomosis is done using endoscopic linear staplers only without any complicated rotation. In this report, we introduced LSGD and compared its short-term and long-term outcomes with DSGD.

METHODS

We analyzed 261 consecutive gastric cancer patients who underwent the intracorporeal gastroduodenostomy between January 2009 and May 2014 (LSGD: 190, DSGD: 71), retrospectively. All of them underwent a laparoscopic or robotic distal gastrectomy with regional lymph node dissection. Early surgical outcomes such as operation time, postoperative complications, days until soft diet began, length of hospital stay, and endoscopic findings in postoperative 6 and 12 months were evaluated.

RESULTS

Although the proportion of robotic approach and D2 lymphadenectomy were significantly higher in LSGD group, the rates for overall complications (13.2 % [LSGD] vs. 9.9 % [DSGD], p = 0.470) and major complications (5.8 vs. 5.6 %, p = 1.0) were similar between two groups. There were no differences in anastomotic bleeding (1.1 vs. 1.4 %, p = 1.0), stenosis (3.2 vs. 2.8 %, p = 1.0), and leakage (0.5 vs. 0.0 %, p = 1.0). Endoscopy performed 6 months postoperatively showed that residual food (p = 0.022), gastritis (p = 0.018), and bile reflux (42.0 vs. 63.2 %, p = 0.003) were significantly decreased in LSGD and there were no significant differences in postoperative 12 months.

CONCLUSION

LSGD is an innovative reconstruction technique with comparable short-term outcomes to DSGD. In addition, reduced residual food, gastritis, and bile reflux were seen in LSGD.

Robotic gastrectomy for gastric cancer

Robotic surgery for gastric cancer overcomes technical difficulties with laparoscopic gastrectomy. Its benefits include reduced intraoperative bleeding and shorter hospital stays; it is also easier to learn. Because accuracy increases during lymphadenectomy, a larger number of lymph nodes is likely to be retrieved using robotic gastrectomy. Higher costs and longer operation times have hindered the widespread adaptation and use of robotic surgery. In this review, we summarize the current status and issues regarding robotic gastrectomy.

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.

A Simplified Technique for Tumor Localization Using Preoperative Endoscopic Clipping and Radio-opaque Markers during Totally Laparoscopic Gastrectomy

Tumor localization during intracorporeal anastomosis after totally laparoscopic distal gastrectomy (TLDG) is challenging. The aim of this study was to assess the simplicity and feasibility of locating tumors in the stomach using radio-opaque markers and preoperative endoscopic clipping. The intra- and postoperative findings of 29 patients who underwent TLDG with intracorporeal anastomosis between January 2012 and March 2013 were reviewed. Preoperative endoscopic clips were applied just proximal to the tumor by specialized endoscopists, and surgical gauze with an attached radio-opaque marker (3 mm x 60 mm) was prepared. The marker was fixed to either the anterior or posterior of the stomach, above the predicted site of the tumor, using suture ties. Portable abdominal radiography was used during the laparoscopic surgery, and the stomach was resected using guidance by the radiomarker. The radio-opaque marker and the endoscopic clips were clearly visible by intraoperative abdominal radiography. All patients received curative resection. No complications or deaths were encountered. The mean distance between the endoscopic clips and the radiomarker by portable intraoperative radiography was 21.3 ± 18.3 mm, whereas the actual in situ mean distance was 20.7 ± 17.6 mm. This difference was not statistically significant ( P > 0.05). It is imperative that preoperative endoscopic clips are applied just proximal to the tumor by specialized endoscopists. The use of a radio-opaque marker is a simple and feasible way to locate tumors during totally laparoscopic gastrectomy.

Laparoscopic gastric surgery for cancer: Where do we stand?

Gastric cancer poses a significant public health problem, especially in the Far East, due to its high incidence in these areas. Surgical treatment and guidelines have been markedly different in the West, but nowadays this debate is apparently coming to an end. Laparoscopic surgery has been employed in the surgical treatment of gastric cancer for two decades now, but with controversies about the extent of resection and lymphadenectomy. Despite these difficulties, the apparent advantages of the laparoscopic approach helped its implementation in early stage and distal gastric cancer, with an increase on the uptake for distal gastrectomy for more advanced disease and total gastrectomy. Nevertheless, there is no conclusive evidence about the laparoscopic approach yet. In this review article we present and analyse the current status of laparoscopic surgery in the treatment of gastric cancer.

A noble method for intraoperative fine localization during laparoscopic gastric local resection: endoscopic submucosal cutting and light transmission

BACKGROUND

The main requirements when performing laparoscopic local resection for early mucosal tumors of the stomach are a clearly defined cancer-free margin and precise tumor localization. In this study, a novel method for precise intraoperative tumor localization and appropriate resection in a porcine model is introduced: endoscopic submucosal cutting and light transmission (ESCLT).

METHODS

A total of 15 cases of laparoscopic local resection were performed in 6 pigs. The size of the target lesions was approximately 20 mm. The imaginary lesions were located in the high body anterior wall, posterior wall, lower body posterior wall, angle, and antrum anterior wall of the stomach. Mucosal marking around the lesions, mucosal precutting surrounding the marking, and submucosal cutting along the precutting line using white light endoscopy were sequentially performed. Next, an endoscopic light source was placed directly in front of the lesion. Exact oval-shaped submucosal cutting margins were identified via laparoscopy. Laparoscopic local resection was performed after the minimal distance from the stapler line to the submucosal cutting line was confirmed. The sizes of the mucosal marking, submucosal cutting line, and the entire resected mucosa and serosa were measured.

RESULTS

The procedure was completed successfully in all pigs. Local resection was completed on all of the lesions. The mean endoscopic and laparoscopic procedure times were 26.1 and 12.7 min, respectively. The mean size of the resected specimens was: (i) marking lesion, 22 × 19.5 mm; (ii) submucosal cutting line, 26.7 × 23.2 mm; (iii) entire resected mucosa, 37 × 31 mm; and (iv) entire resected serosa, 41.7 × 33.1 mm. There was no intraoperative morbidity.

CONCLUSION

ESCLT provides a precise and useful method of intraoperative tumor localization during laparoscopic local resection of the stomach in terms of minimizing the resection of normal stomach tissue and guaranteeing adequate mucosal safety margins.

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.

Long-term outcomes of laparoscopic gastrectomy for gastric cancer

BACKGROUND

Laparoscopic gastrectomy (LG) has been established as a procedure for the treatment of gastric cancer. However, there have been few reports on the long-term outcomes of LG for gastric cancer. The aim of this study is to investigate the long-term outcomes of LG for gastric cancer.

METHODS

A total of 278 consecutive patients who underwent LG in our unit between January 1999 and December 2006 were included in this study. Survival, recurrence, and late gastrointestinal complications were analyzed.

RESULTS

The median follow-up period was 73.7 mo (6-165 mo). Distal gastrectomy was performed in 229 patients, total gastrectomy in 23 patients, proximal gastrectomy in 15 patients, and pylorus-preserving gastrectomy in 11 patients. Five-year overall and disease-specific survival rates were 91% and 99% for stage IA, 75% and 91% for stage IB, 72% and 88% for stage II, and 40% and 50% for stage III, respectively. Recurrences were detected in 15 (5.4%) patients, including 5 distant lymph node, 5 peritoneal, 4 hematogenous, and 1 locoregional recurrences. Bowel obstruction occurred in 4 (1.4%) patients, and gallstones developed in 37 (15%) patients.

CONCLUSIONS

This follow-up investigation suggested that LG for gastric cancer is a feasible procedure from the standpoint of long-term oncological outcome and postoperative complications.

Development of a novel marking system for laparoscopic gastrectomy using endoclips with radio frequency identification tags: feasibility study in a canine model

BACKGROUND

Intraoperative identification of early gastric cancer is difficult to conduct during laparoscopic procedures. In this study, we investigated the feasibility and accuracy of a newly developed marking system using endoclips with radio frequency identification (RFID) tags in a canine model.

METHODS

RFID is a wireless near field communication technology. Among the open frequency bands available for medical use, 13.56 MHz is suitable for a surgical marking system because of the similar and linear signal decay both in air and in biological tissues. The proposed system consists of four parts: (a) endoclips with RFID tags, (b) endo-clip applier equipment, (c) laparoscopic locating probe, and (d) signal processing units with audio interface. In the experimental setting using canine models, RFID-tagged endoclips were applied to the mucosa of each dog's stomach. During the subsequent operation, the clips with RFID tags placed in five dogs were located by the detection of the RFID signal from the tag (RFID group), and the conventional clips in the other six dogs were located by finger palpation (FP group). The detected sites were marked by ablation on the serosal surface. Distance between the clips and the metal pin needles indicating ablated sites were measured with X-ray radiographs of the resected specimen.

RESULTS

All clips were successfully detected by the marking system in the RFID group (10/10) and by finger palpation in the FP group (17/17). The medians of detection times were 31.5 and 25.0 s, respectively; the distances were 5.63 and 7.62 mm, respectively. The differences were not statistically significant. No adverse event related to the procedures was observed.

CONCLUSIONS

Endoclips with RFID tags were located by our novel marking system in an experimental laparoscopic setting using canine stomachs with substantial accuracy comparable to conventional endoclips located by finger palpation through an open approach.

Application of a novel near infrared-fluorescence giant vesicle- and polymerasome-based tissue marker for endoscopic and laparoscopic navigation

In this study, we describe the development of a novel tissue marker that can be injected from within the digestive tract by using an endoscopic instrument, and visualized using near-infrared (NIR) fluorescence imaging. The marker was prepared in three steps, (i) mixing NIR-fluorescent indocyanine green (ICG) with giant vesicles (GVs) of lecithin, (ii) suspending the ICG-containing giant vesicles (ICG-GV) in an oil phase dissolving polyglycerol-polyricinoleate (PGPR), and (iii) centrifugation of the suspension layered on a buffered solution to obtain a giant polymer vesicle (polymerasome) containing ICG-GV. We injected the tissue marker into the inner gastric surface of an anesthetized pig using an endoscopic syringe, and observed the injection site using a fluorescence laparoscopic camera. The diameter of the spot blur was approximately 2 cm over a 5-h period, demonstrating the utility of this procedure as a tissue marker for tumor marking, and suggesting its potential for assisting navigation during surgical procedures.

Modified fusion imaging combining CT gastrography and CT angiography: an initial experience of preoperative mapping prior to laparoscopic exogastric wedge resection of small (<3 cm) gastric submucosal lesions

PURPOSE

To evaluate the feasibility of modified fusion imaging (MFI) combining CT gastrography (CTG) and CT angiography (CTA) in the preoperative mapping and intraoperative localization of small (<3 cm) submucosal lesions (SMLs) during laparoscopic exogastric wedge resection.

METHODS

Thirty consecutive patients scheduled for laparoscopic wedge resection of small SMLs (<3 cm) were enrolled. MFI was reconstructed using a volume rendering of the arterial phase CT data acquired after gastric distension. With MFI, the possibility of preoperative mapping and feasibility for successful intraoperative localization was evaluated using intraoperative findings as the reference standard.

RESULTS

In 21 of 30 patients (70%), preoperative mapping was possible. Preoperative mapping was feasible for successful intraoperative localization in 13 of 14 patients (93%) who underwent exogastric resection.

CONCLUSIONS

MFI combining CTG and CTA is a feasible method for developing preoperative and intraoperative "road maps" for performing laparoscopic exogastric wedge resection of small SMLs.

Efficacy of intraoperative gastroscopy for tumor localization in totally laparoscopic distal gastrectomy for cancer in the middle third of the stomach

BACKGROUND

Determining resection margins for gastric cancer, which generally is not exposed to the serosal surface of the stomach, is the most important priority during totally laparoscopic gastrectomy (TLG). This study aimed to evaluate the usefulness of intraoperative gastroscopy for direct marking of tumors during TLG for gastric cancer in the middle third of the stomach.

METHODS

From May 2011 through July 2012, 20 patients with a diagnosis of adenocarcinoma in the middle third of the stomach were enrolled in this case series. Preoperative gastroscopy for tumor localization was not performed for these patients. After the first portion of the duodenum was mobilized from the pancreas and clamped with a laparoscopic intestinal clamp, 2-3 ml of indigo carmine was administered through an endoscopic injector into the gastric muscle layer at the proximal margin of the tumor.

RESULTS

Based on intraoperative gastroscopic findings, distal subtotal gastrectomy was performed for 18 patients, with the authors deciding to perform total gastrectomy for two patients. A specimen was extracted after distal gastrectomy to confirm sufficient distance from the resection margin to the tumor before reconstruction. All the patients had tumor-free margins and required no additional resection. No morbidity related to gastroscopic procedure occurred, and the time required has been gradually decreased to about 5 min.

CONCLUSIONS

Intraoperative gastroscopy for tumor localization is an accurate and comfortable method for gastric cancer patients undergoing totally laparoscopic distal gastrectomy.

Totally laparoscopic distal gastrectomy after learning curve completion: comparison with laparoscopy-assisted distal gastrectomy

Purpose

The aims are to: (i) display the multidimensional learning curve of totally laparoscopic distal gastrectomy, and (ii) verify the feasibility of totally laparoscopic distal gastrectomy after learning curve completion by comparing it with laparoscopy-assisted distal gastrectomy.

Materials and Methods

From January 2005 to June 2012, 247 patients who underwent laparoscopy-assisted distal gastrectomy (n=136) and totally laparoscopic distal gastrectomy (n=111) for early gastric cancer were enrolled. Their clinicopathological characteristics and early surgical outcomes were analyzed. Analysis of the totally laparoscopic distal gastrectomy learning curve was conducted using the moving average method and the cumulative sum method on 180 patients who underwent totally laparoscopic distal gastrectomy.

Results

Our study indicated that experience with 40 and 20 totally laparoscopic distal gastrectomy cases, is required in order to achieve optimum proficiency by two surgeons. There were no remarkable differences in the clinicopathological characteristics between laparoscopy-assisted distal gastrectomy and totally laparoscopic distal gastrectomy groups. The two groups were comparable in terms of open conversion, combined resection, morbidities, reoperation rate, hospital stay and time to first flatus (P>0.05). However, totally laparoscopic distal gastrectomy had a significantly shorter mean operation time than laparoscopy-assisted distal gastrectomy (P<0.01). We also found that intra-abdominal abscess and overall complication rates were significantly higher before the learning curve than after the learning curve (P<0.05).

Conclusions

Experience with 20~40 cases of totally laparoscopic distal gastrectomy is required to complete the learning curve. The use of totally laparoscopic distal gastrectomy after learning curve completion is a feasible and timesaving method compared to laparoscopy-assisted distal gastrectomy.

Comparison of laparoscopy-assisted and totally laparoscopic distal gastrectomy: the short-term outcome at a low volume center

Purpose

Laparoscopic gastrectomy has been adopted for the treatment of gastric cancer, and despite the technical difficulties, totally laparoscopic distal gastrectomy has been considered less invasive than laparoscopy-assisted distal gastrectomy. Although there have been many reports regarding the feasibility and safety of totally laparoscopic distal gastrectomy at large volume centers, few reports have been conducted at low-volume centers. The purpose of this study is to try to assess the feasibility and safety of totally laparoscopic distal gastrectomy at a low volume center through the analysis of short-term outcomes of totally laparoscopic distal gastrectomy compared with laparoscopy-assisted distal gastrectomy.

Materials and Methods

The clinical data and short-term surgical outcomes of 35 patients who had undergone laparoscopy-assisted distal gastrectomy between April 2007 and March 2010, and 37 patients who underwent totally laparoscopic distal gastrectomy between April 2010 and August 2012 were retrospectively reviewed.

Results

There was no significant difference in the demographic and clinical data. However the reconstruction method and extent of lymphadenectomy showed statistically significant differences. Operation time and estimated blood loss did not show significant differences. Surgical and medical complications did not show significant differences but postoperative courses including time-to-first oral intake and postoperative hospital stay were significantly increased.

Conclusions

Our study shows that totally laparoscopic distal gastrectomy is technically feasible at a low volume center. Therefore, totally laparoscopic distal gastrectomy can be considered as one of the surgical treatment for early gastric cancer. However the possibility that totally laparoscopic distal gastrectomy may have less benefit should also be considered.