Sentinel node mapping guided by indocyanine green fluorescence imaging in gastric cancer. Ann Surg. 2009;249:58-62. [PMID: 19106676 DOI: 10.1097/sla.0b013e3181927267]

Minimally invasive surgery in gastric cancer

Minimally invasive surgery for gastric cancer has rapidly gained popularity due to the early detection of early gastric cancer. As advances in instruments and the accumulation of laparoscopic experience increase, laparoscopic techniques are being used for less invasive but highly technical procedures. Recent evidence suggests that the short- and long-term outcomes of minimally invasive surgery for early gastric cancer and advanced gastric cancer are comparable to those of conventional open surgery. However, these results should be confirmed by large-scale multicenter prospective randomized controlled clinical trials.

New approaches to gastric cancer staging: Beyond endoscopic ultrasound, computed tomography and positron emission tomography

Currently, there is no single gold standard modality for staging of gastric cancer and several methods have been used complementarily in the each clinical situation. To make up for the shortcomings of conventional modalities such as endoscopic ultrasound, computed tomography and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography, numerous attempts with new approaches have been made for gastric cancer staging. For T staging, magnifying endoscopy with narrow-band was evaluated to differentiate mucosal cancer from submucosal cancer. Single/double contrast-enhanced ultrasound and diffusion-weighted magnetic resonance imaging were also tried to improve diagnostic accuracy of gastric cancer. For intraoperative staging with sentinel node mapping, indocyanine green infrared and fluorescence imaging was introduced. In addition, to detect micrometastasis, real-time reverse transcription-polymerase chain reaction system with multiple markers was studied. Staging laparoscopy using 5-aminolevulinic acid-mediated photodynamic diagnosis and percutaneous diagnostic peritoneal lavage were also evaluated. However, most studies reporting new staging methods is preliminary and further studies for validation in clinical practice are needed. In this mini-review, we discuss new progress in gastric cancer staging. Especially, we focus on new diagnostic approach to gastric cancer staging beyond the conventional modalities and briefly review the remarkable clinical results of the studies published over the past three years.

Clinical significance of molecular diagnosis for gastric cancer lymph node micrometastasis

Advances in molecular diagnostic tools have allowed the identification of lymph node micrometastasis (LNM), including isolated tumor cells, in cancer patients. While immunohistochemistry and reverse transcription-polymerase chain reaction have been used to identify LNM in patients with gastric cancer, the clinical significance of this finding remains unclear. Recently, minimally invasive treatments, such as endoscopic submucosal dissection and laparoscopic surgery, are widely performed to help improve postsurgical quality of life (QOL). However, it is important to maintain the balance between QOL and curability when making treatments decision for patients with gastric cancer. If minimally invasive surgery based on accurate intraoperative LNM diagnosis was established, it could be performed safely. Therefore, we reviewed the clinical significance of LNM detected by molecular techniques as an important target for treatment decision making with gastric cancer patients.

Intraoperative imaging-guided cancer surgery: from current fluorescence molecular imaging methods to future multi-modality imaging technology

Cancer is a major threat to human health. Diagnosis and treatment using precision medicine is expected to be an effective method for preventing the initiation and progression of cancer. Although anatomical and functional imaging techniques such as radiography, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) have played an important role for accurate preoperative diagnostics, for the most part these techniques cannot be applied intraoperatively. Optical molecular imaging is a promising technique that provides a high degree of sensitivity and specificity in tumor margin detection. Furthermore, existing clinical applications have proven that optical molecular imaging is a powerful intraoperative tool for guiding surgeons performing precision procedures, thus enabling radical resection and improved survival rates. However, detection depth limitation exists in optical molecular imaging methods and further breakthroughs from optical to multi-modality intraoperative imaging methods are needed to develop more extensive and comprehensive intraoperative applications. Here, we review the current intraoperative optical molecular imaging technologies, focusing on contrast agents and surgical navigation systems, and then discuss the future prospects of multi-modality imaging technology for intraoperative imaging-guided cancer surgery.

Sentinel node navigation surgery in gastric cancer: Current status

The theory behind using sentinel node mapping and biopsy in gastric cancer surgery, the so-called sentinel node navigation surgery, is to limit the extent of surgical tissue dissection around the affected organ and subsequently the accompanied morbidity. However, obstacles on the clinical correspondence of sentinel node navigation surgery in everyday practice have occasionally alleviated researchers’ interest on the topic. Only recently with the widespread use of minimally invasive surgical techniques, i.e., laparoscopic gastric cancer resections, surgical community’s interest on the topic have been unavoidably reflated. Double tracer methods appear superior compared to single tracer techniques. Ongoing research is now focused on the invention of new lymph node detection methods utilizing sophisticated technology such as infrared ray endoscopy, florescence imaging and near-infrared technology. Despite its notable limitations, hematoxylin/eosin is still the mainstay staining for assessing the metastatic status of an identified lymph node. An intra-operatively verified metastatic sentinel lymph node will dictate the need for further conventional lymph node dissection. Thus, laparoscopic resection of the gastric primary tumor combined with the appropriate lymph node dissection as determined by the process of sentinel lymph node status characterization represents an option for early gastric cancer. Patients with T3 or more advanced disease should still be managed conventionally with resection plus standard lymph node dissection.

Visualization of blood supply route to the reconstructed stomach by indocyanine green fluorescence imaging during esophagectomy

Background

Ensuring an adequate blood supply is essential to the safe performance of an anastomosis during esophagectomy and the prevention of anastomotic leakage. Recently, indocyanine green (ICG) fluorescence imaging has been used to visualize the blood supply when anastomosis is performed in vascular surgery. We used ICG fluorescence imaging to visualize the blood supply for reconstruction during esophagectomy.

Methods

Since January 2009, we have performed ICG fluorescence imaging in 33 patients with thoracic esophageal cancer who underwent thoracic esophagectomy. After pulling up the reconstructed stomach, 2.5 mg of ICG was injected as a bolus. ICG fluorescence imaging was performed with a near-infrared camera, and the images were recorded.

Results

ICG fluorescence was easily detected in all patients 1 min after injection. Vascular networks were well visualized in the gastric wall and omentum. The blood supply route was located in the greater omentum beside the splenic hilum in 22 (66.7%) of the 33 patients.

Conclusions

ICG fluorescence can be used to evaluate the blood supply to the reconstructed stomach in patients undergoing esophagectomy for esophageal cancer. On ICG fluorescence imaging, the splenic hiatal vessels were the major blood supply for the anastomosis in most patients.

Sentinel lymph node navigation surgery for early stage gastric cancer

We attempted to evaluate the history of sentinel node navigation surgery (SNNS), technical aspects, tracers, and clinical applications of SNNS using Infrared Ray Electronic Endoscopes (IREE) combined with Indocyanine Green (ICG). The sentinel lymph node (SLN) is defined as a first lymph node (LN) which receives cancer cells from a primary tumor. Reports on clinical application of SNNS for gastric cancers started to appear since early 2000s. Two prospective multicenter trials of SNNS for gastric cancer have also been accomplished in Japan. Kitagawa et al reported that the endoscopic dual (dye and radioisotope) tracer method for SN biopsy was confirmed acceptable and effective when applied to the early-stage gastric cancer (EGC). We have previously reported the usefulness of SNNS in gastrointestinal cancer using ICG as a tracer, combined with IREE (Olympus Optical, Tokyo, Japan) to detect SLN. LN metastasis rate of EGC is low. Hence, clinical application of SNNS for EGC might lead us to avoid unnecessary LN dissection, which could preserve the patient's quality of life after operation. The most ideal method of SNNS should allow secure and accurate detection of SLN, and real time observation of lymphatic flow during operation.

Indocyanine green angiography in endoscopic third ventriculostomy

BACKGROUND

Endoscopic third ventriculostomy (ETV) has become a well-established method for the treatment of noncommunicating hydrocephalus with a high success rate and a relatively low morbidity rate. However, vessel injury has been repeatedly reported, often with a fatal outcome. Vessel injury is considered to be the most threatening complication. The use of indocyanine green (ICG) angiography has become an established tool in vascular microneurosurgery.

OBJECTIVE

We report our initial experience with endoscopic ICG angiography in ETV for intraoperative visualization of the basilar artery and its perforators to reduce the risk of vascular injury.

METHODS

Eleven patients with noncommunicating hydrocephalus underwent ETV. Before opening of the third ventricular floor, ICG angiography was performed using a prototype neuroendoscope for intraoperative visualization of ICG fluorescence.

RESULTS

In 10 patients, ETV and ICG angiography were successfully performed. In 1 case, ICG angiography failed. Even in the presence of an opaque floor of the third ventricle (n = 5), ICG angiography clearly demonstrated the course of the basilar artery and its major branches and was considered useful.

CONCLUSION

ICG angiography has the potential to become a useful adjunct in ETV for better visualization of vessel structures, especially in the presence of aberrant vasculature, a nontranslucent floor of the third ventricle, or in case of reoperations.

Design and characterization of an optimized simultaneous color and near-infrared fluorescence rigid endoscopic imaging system

We report the design, characterization, and validation of an optimized simultaneous color and near-infrared (NIR) fluorescence rigid endoscopic imaging system for minimally invasive surgery. This system is optimized for illumination and collection of NIR wavelengths allowing the simultaneous acquisition of both color and NIR fluorescence at frame rates higher than 6.8 fps with high sensitivity. The system employs a custom 10-mm diameter rigid endoscope optimized for NIR transmission. A dual-channel light source compatible with the constraints of an endoscope was built and includes a plasma source for white light illumination and NIR laser diodes for fluorescence excitation. A prism-based 2-CCD camera was customized for simultaneous color and NIR detection with a highly efficient filtration scheme for fluorescence imaging of both 700- and 800-nm emission dyes. The performance characterization studies indicate that the endoscope can efficiently detect fluorescence signal from both indocyanine green and methylene blue in dimethyl sulfoxide at the concentrations of 100 to 185 nM depending on the background optical properties. Finally, we performed the validation of this imaging system in vivo during a minimally invasive procedure for thoracic sentinel lymph node mapping in a porcine model.

Analysis of the lymphatic stream to predict sentinel nodes in gastric cancer patients

PURPOSE

To investigate the pattern of lymphatic drainage in gastric cancer patients to predict sentinel node placement according to tumor location.

METHODS

A total of 462 pT1 or T2 gastric adenocarcinoma patients with metastasis to 1-3 lymph nodes (LNs) who had undergone lymphadenectomy greater than D1+β were included in the study. The distribution of metastatic LNs was evaluated according to tumor longitudinal and circumferential location. The incidence rate of atypical metastasis (skip or transversal metastasis) and related clinicopathologic factors were analyzed.

RESULTS

The rates of skip and transversal metastasis were 15.8 % (73 of 462) and 10.3 % (23 of 224), respectively. Atypical metastasis was observed regardless of tumor location. Tumors that showed the most frequent atypical metastasis were located in the lower third and lesser curvature (LC) of the stomach (29.0 % for skip metastasis and 18.0 % for transversal metastasis). In uni- and multivariate analyses, an LC tumor was a risk factor for skip metastasis, and tumor located circumferentially in the LC or longitudinally in the lower third of the stomach was an independent risk factor for transversal metastasis. There was no correlation between tumor aggressiveness and atypical metastasis.

CONCLUSIONS

Tumors at any location had a chance of atypical metastasis; however, those located longitudinally in the lower or circumferentially at the LC had a significantly higher chance of atypical metastasis compared to other locations. When sentinel node navigation surgery is applied, special care should be taken with tumors at these locations to prevent false-negative results.

Feasibility of sentinel node navigation surgery after noncurative endoscopic resection for early gastric cancer

BACKGROUND AND AIM

Recently, the use of additional surgery after noncurative endoscopic resection has gradually increased due to the rapid spread of endoscopic treatments in selected patients with early gastric cancer. Sentinel node navigation surgery (SNNS) has also been recognized as a minimally invasive surgery with personalized lymphadenectomy in early gastric cancer. Here, we assessed the feasibility of SNNS after noncurative endoscopic resection for early gastric cancer.

METHODS

Sixteen patients with early gastric cancer, in whom additional surgery had been indicated due to noncurative endoscopic resection, were enrolled. They underwent a gastrectomy with standard lymphadenectomy. One day before surgery, (99m) technetium-tin colloid was endoscopically injected into the submucosa around the tumor. After surgery, the uptake of radioisotope in dissected lymph nodes was measured using Navigator GPS. Then, all dissected lymph nodes were investigated by hematoxylin-eosin staining and immunohistochemistry using an antihuman cytokeratin monoclonal antibody.

RESULTS

Hematoxylin-eosin staining demonstrated lymph node metastasis in two (12.5%) of 16 patients and in three (0.8%) of 382 nodes. However, immunohistochemistry showed that none of the patients had lymph node micrometastasis. Sentinel nodes (SNs) were identified in all patients. The mean number of SNs was 3.1 (range, 1-6). Among two patients with lymph node metastasis, the SNs, at least, contained positive nodes. Accordingly, the false-negative and accuracy rates were 0% and 100%, respectively.

CONCLUSION

Our results indicate that SNNS may have potential as a further minimally invasive surgery in early gastric cancer patients after noncurative endoscopic resection.

Image-guided cancer surgery using near-infrared fluorescence

Paradigm shifts in surgery arise when surgeons are empowered to perform surgery faster, better and less expensively than current standards. Optical imaging that exploits invisible near-infrared (NIR) fluorescent light (700-900 nm) has the potential to improve cancer surgery outcomes, minimize the time patients are under anaesthesia and lower health-care costs largely by way of its improved contrast and depth of tissue penetration relative to visible light. Accordingly, the past few years have witnessed an explosion of proof-of-concept clinical trials in the field. In this Review, we introduce the concept of NIR fluorescence imaging for cancer surgery, examine the clinical trial literature to date and outline the key issues pertaining to imaging system and contrast agent optimization. Although NIR seems to be superior to many traditional imaging techniques, its incorporation into routine care of patients with cancer depends on rigorous clinical trials and validation studies.

Laparoscopic gastrectomy for gastric cancer

Laparoscopic gastrectomy for gastric cancer is rapidly becoming popular because of the technical developments and the accumulated data of laparoscopic surgery in gastric cancer patients. The aim of this review is to present the current body of evidence and to highlight controversial issues of laparoscopic gastrectomy for gastric cancer. Laparoscopic distal gastrectomy (LDG) provides better or comparable outcomes compared to conventional open distal gastrectomy (ODG) in terms of short-term results. The long-term survival of LDG is expected to be comparable to that of ODG in early-stage gastric cancer, and an ongoing Korean multicenter randomized controlled trial (KLASS-01) will provide more clear evidence. Laparoscopic total gastrectomy is still selectively performed compared to LDG, and there is still debate on the safety of the laparoscopic esophagojejunostomy technique. Laparoscopic pylorus-preserving gastrectomy seems to be preferred for early gastric cancer in the middle third of the stomach in terms of functional advantages and comparable oncologic outcome. Evidence for LDG for advanced gastric cancer is still insufficient and the issue of lack of generalization still remains, even after ongoing multicenter randomized controlled trials have revealed clinical evidence. Laparoscopic sentinel node navigation surgery is still experimental and the surgical procedure has yet to be standardized. Robotic gastrectomy is feasible for early gastric cancer in terms of similar outcome, but is much more expensive in comparison to laparoscopic surgery. Its benefit over the conventional laparoscopic gastrectomy has not yet been proven.

Sentinel node navigation surgery in patients with early gastric cancer

Clinical application of sentinel node (SN) mapping in patients with early gastric cancer has been a controversial issue for years. However, a recent meta-analysis and a prospective multicenter trial of SN mapping for early gastric cancer have shown acceptable SN detection rates and accuracy of determination of lymph node status. A dual-tracer method that utilizes radioactive colloids and blue dyes is currently considered the most reliable method for the stable detection of SNs in patients with early gastric cancer. However, new technologies such as indocyanine green infrared or fluorescence imaging might revolutionize the SN mapping procedures in gastric cancer. For early-stage gastric cancer such as cT1N0, for which a better prognosis can be potentially achieved through conventional surgical approaches, the establishment of individualized, minimally invasive treatments that may retain the patients' quality of life should be the next surgical challenge. Although there are many unresolved technical issues, laparoscopic SN biopsy with laparoscopic minimized gastrectomy or endoscopic mucosal resection/endoscopic submucosal dissection could be a promising strategy to achieve this goal.

Is a fluorescence navigation system with indocyanine green effective enough to detect liver malignancies?

BACKGROUND

Although several reports have shown the efficacy of a fluorescence navigation system (FNS) with indocyanine green (ICG) to detect liver malignancies during hepatectomy, the real accuracy of this procedure is not yet clear. This study aimed to analyze the actual efficacy of ICG-FNS in cirrhotic and non-cirrhotic livers.

METHODS

Ten cirrhotic whole livers explanted from liver transplant recipients and 23 non-cirrhotic livers from patients who underwent hepatectomy for various kinds of liver tumors were investigated with ICG-FNS. All surgical specimens were analyzed macroscopically and pathologically.

RESULTS

In the patients with a cirrhotic liver, most nodules illuminated by ICG-FNS were diagnosed as regenerative nodules pathologically. The positive predictive value was 5.4%. There was a significant difference in positive predictive value to detect malignant liver tumors between cirrhotic liver and non-cirrhotic liver (5.4% vs 100%, P < 0.0001). In the non-cirrhotic livers, 11 of 33 (32.4%) tumors were not recognized by ICG-FNS through the liver surface before resection. There was a significant difference in the depth from the liver surface to tumor between illuminated nodules and non-illuminated nodules (1.5 mm vs 11.6 mm, P < 0.01).

CONCLUSIONS

It is necessary to know the limitation of ICG-FNS when detecting liver malignancies in both cirrhotic and non-cirrhotic livers.

Dual-modality imaging with 99mTc and fluorescent indocyanine green using surface-modified silica nanoparticles for biopsy of the sentinel lymph node: an animal study

Background

We propose a new approach to facilitate sentinel node biopsy examination by multimodality imaging in which radioactive and near-infrared (NIR) fluorescent nanoparticles depict deeply situated sentinel nodes and fluorescent nodes with anatomical resolution in the surgical field. For this purpose, we developed polyamidoamine (PAMAM)-coated silica nanoparticles loaded with technetium-99m (^99mTc) and indocyanine green (ICG).

Methods

We conducted animal studies to test the feasibility and utility of this dual-modality imaging probe. The mean diameter of the PAMAM-coated silica nanoparticles was 30 to 50 nm, as evaluated from the images of transmission electron microscopy and scanning electron microscopy. The combined labeling with ^99mTc and ICG was verified by thin-layer chromatography before each experiment. A volume of 0.1 ml of the nanoparticle solution (7.4 MBq, except for one rat that was injected with 3.7 MBq, and 1 μg of an ICG derivative [ICG-sulfo-OSu]) was injected submucosally into the tongue of six male Wistar rats.

Results

Scintigraphic images showed increased accumulation of ^99mTc in the neck of four of the six rats. Nineteen lymph nodes were identified in the dissected neck of the six rats, and a contact radiographic study showed three nodes with a marked increase in uptake and three nodes with a weak uptake. NIR fluorescence imaging provided real-time clear fluorescent images of the lymph nodes in the neck with anatomical resolution. Six lymph nodes showed weak (+) to strong (+++) fluorescence, whereas other lymph nodes showed no fluorescence. Nodes showing increased radioactivity coincided with the fluorescent nodes. The radioactivity of 15 excised lymph nodes from the four rats was assayed using a gamma well counter. Comparisons of the levels of radioactivity revealed a large difference between the high-fluorescence-intensity group (four lymph nodes; mean, 0.109% ± 0.067%) and the low- or no-fluorescence-intensity group (11 lymph nodes; mean, 0.001% ± 0.000%, p < 0.05). Transmission electron microscopy revealed that small black granules were localized to and dispersed within the cytoplasm of macrophages in the lymph nodes.

Conclusion

Although further studies are needed to determine the appropriate dose of the dual-imaging nanoparticle probe for effective sensitivity and safety, the results of this animal study revealed a novel method for improved node detection by a dual-modality approach for sentinel lymph node biopsy.

Molecular imaging of experimental abdominal aortic aneurysms

Current laboratory research in the field of abdominal aortic aneurysm (AAA) disease often utilizes small animal experimental models induced by genetic manipulation or chemical application. This has led to the use and development of multiple high-resolution molecular imaging modalities capable of tracking disease progression, quantifying the role of inflammation, and evaluating the effects of potential therapeutics. In vivo imaging reduces the number of research animals used, provides molecular and cellular information, and allows for longitudinal studies, a necessity when tracking vessel expansion in a single animal. This review outlines developments of both established and emerging molecular imaging techniques used to study AAA disease. Beyond the typical modalities used for anatomical imaging, which include ultrasound (US) and computed tomography (CT), previous molecular imaging efforts have used magnetic resonance (MR), near-infrared fluorescence (NIRF), bioluminescence, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). Mouse and rat AAA models will hopefully provide insight into potential disease mechanisms, and the development of advanced molecular imaging techniques, if clinically useful, may have translational potential. These efforts could help improve the management of aneurysms and better evaluate the therapeutic potential of new treatments for human AAA disease.

Clinical significance of lymph node micrometastasis in gastric cancer

Recently, the existence of lymph node micrometastasis (LNM), including isolated tumor cells, has been focused on during the development of molecular diagnostic tools for lymph node metastasis in various malignant neoplasms. In particular, immunohistochemistry and reverse transcription-polymerase chain reaction have been reported to be available for the detection of LNM in gastric cancer. However, at present, the clinical significance of LNM remains unclear in patients with gastric cancer. Therefore, we cannot strategically make light of this issue in clinical management. Currently, minimally invasive treatments, such as endoscopic submucosal dissection and laparoscopic surgery with personalized lymphadenectomy, are widely performed in consideration of postsurgical quality of life (QOL). However, it is important to maintain the balance between QOL and curability when selecting surgical treatments for patients with gastric cancer. If minimally invasive surgery based on LNM status was established for patients with early gastric cancer, it could be performed safely. We reviewed the clinical significance of LNM as an important strategic target in patients with gastric cancer.

An experimental study to evaluate the Fluobeam 800 imaging system for fluorescence-guided lymphatic imaging and sentinel node biopsy

BACKGROUND

Visualization of the lymphatic system is challenging. Lymphatic imaging is a crucial diagnostic tool for benign and malignant lymphatic pathologies. Fluorescence-guided imaging allows selective lymphatic mapping and sentinel lymph node (SLN) identification. There are a few fluorescence systems, but some drawbacks remain due to technical and ergonomic aspects. The aim of this study was to evaluate the feasibility of the new Fluobeam 800 imaging system.

METHODS

After approval by the ethics committee, the system was evaluated for lymphography and SLN biopsy in an animal model. Five pigs each with 4 lymph node (LN) stations (n = 20 LN stations) were subjected to lymphatic imaging using indocyanine green (ICG). Additionally, the use of ICG was compared with ICG adsorbed to human serum albumin (ICG-HSA). Lymphatic vessels and SLN identification rates were measured.

RESULTS

After injection, a clear fluorescence signal of the lymphatic vessels was visualized leading to the LN station. Overall, ICG fluorescence imaging identified a mean of 2.0 lymphatic vessels and 1.1 (range = 1-2) SLN in 20 of 20 LN stations. Reverse lymphography was feasible. A clinical difference in resolution was not detected between use of ICG-HSA and ICG.

CONCLUSION

This is the first study analyzing the feasibility of the Fluobeam 800 imaging system allowing transcutaneous real-time imaging. It enables detection of the SLN by fluorescence retention with increased detection depth and resolution. After fixation to the ceiling, the ergonomics advanced for simultaneous field navigation and dissection. The new system can be applied for lymphatic imaging for lympatico-reconstructive surgery and SLN biopsy.

Near-infrared emitting polymer nanogels for efficient sentinel lymph node mapping

Sentinel lymph node (SLN) mapping has been widely used to predict the metastatic spread of primary tumor to regional lymph nodes in clinical practice. In this research, a new near-infrared (NIR)-emitting polymer nanogel (NIR-PNG) having a hydrodynamic diameter of about 30 nm, which is optimal for lymph node uptake, was developed. The NIR-emitting polymer nanoprobes were designed and synthesized by conjugating IRDye800 organic dye to biodegradable pullulan-cholesterol polymer nanogels. The NIR-PNG nanoprobes were found to be photostable compared with the IRDye800-free dye at room temperature. Upon intradermal injection of the NIR-PNG into the front paw of a mouse, the nanoprobes entered the lymphatic system and migrated to the axillary lymph node within 2 min. The NIR fluorescence signal intensity and retention time of NIR-PNG in the lymph node were superior to the corresponding properties of the IRDye800-free dye. A immunohistofluorescence study of the SLN resected under NIR imaging revealed that the NIR-PNG nanoprobes were predominantly co-localized with macrophages and dendritic cells. Intradermal injection of NIR-PNG nanoprobes into the thigh of a pig permitted real-time imaging of the lymphatic flow toward the SLN. The position of the SLN was identified within 1 min with the help of the NIR fluorescence images. Taken together, the experimental results demonstrating the enhanced photostability and retention time of the NIR-PNG provide strong evidence for the potential utility of these polymer probes in cancer surgery such as SLN mapping.

What is the accuracy of sentinel lymph node biopsy for gastric cancer? A systematic review

BACKGROUND

In gastric cancer, the utility of sentinel lymph node (SLN) biopsy has not been established. SLN may be a good predictor of the pathological status of other lymph nodes and thus the necessity for more extensive surgery or lymph node dissection. We aimed to identify and synthesize findings on the performance of SLN biopsies in gastric cancer.

METHODS

Electronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from 1998 to 2009. Titles and abstracts were independently rated for relevance by a minimum of two reviewers. Techniques, detection rates, accuracy, sensitivity, specificity, and false-negative rates (FNRs) were analyzed. Analysis was performed based on the FNR.

RESULTS

Twenty-six articles met our inclusion criteria. SLN detection using the dye method (DM) was reviewed in 18 studies, the radiocolloid method (RM) was used in 12 studies, and both dye and radiocolloid methods (DUAL) were used in 5 studies. The DM had an overall calculated FNR of 34.7% (95% confidence interval [CI] 21.2, 48.1). The RM had an overall calculated FNR of 18.5% (95% CI 9.1, 28.0). DUAL had an overall calculated FNR of 13.1% (95% CI -0.9, 27.2).

CONCLUSION

Application of the SLN technique may be practical for early gastric cancer. The use of DUAL for identifying SLN may yield a lower FNR than either method alone, although statistical significance was not met.

Diagnostic value of sentinel lymph node biopsy in gastric cancer: a meta-analysis

BACKGROUND

The possible application and validity of the sentinel lymph node (SLN) concept in gastric cancer (GC) is still debated. A systematic review to evaluate the diagnostic value of SLN biopsy (SLNB) in GC is urgently needed.

METHODS

A systematic review of relevant literatures was performed in PubMed, Embase, and The Cochrane Library. A random-effect model was used to pool the data, and subgroup analysis was used to explain the heterogeneities.

RESULTS

A total of 38 included studies (2,128 patients) were included. The pooled SLN identification rate, sensitivity, negative predictive value, and accuracy were 93.7% (95% confidence interval [95% CI]: 91.1-95.6%), 76.9% (95% CI: 71.6-81.4%), 90.3% (95% CI: 86.9-92.9%), and 92.0% (95% CI: 89.9-93.7%), respectively. Subgroup analysis showed that early T stage, combined tracers, submucosal injection method, conventional open surgery, and usage of immunohistochemistry were associated with higher SLN identification rate and sensitivity.

CONCLUSIONS

SLNB in GC is technically feasible with an acceptable sensitivity. However, further studies are needed to confirm the best procedure and standard criteria.

[Prospective comparative study of sentinel lymph node mapping in gastric cancer -- submucosal versus subserosal marking method]

BACKGROUND

Forty percent of patients with gastric cancer undergo unnecessary extended lymph node dissection which may result in higher rate of morbidity and mortality. Successful sentinel lymph node (SLN) mapping may help to reduce the number of extended lymphadenectomy. Various marking methods are in use to detect the sentinel lymph node in gastric cancer.

METHODS

Forty consecutive patients underwent open gastric resection with blue dye mapping and modified D2 lymph node dissection. Sixteen patients (group A) were marked submucosally with endoscopy and 24 patients (group B) were labelled by the surgeon subserosally. The staining method and the lymphadenectomy were supervised by the same surgeon.

RESULTS

A total of 795 lymph nodes were removed and examined. The mean number of blue nodes was 4.1 per patient in group A and 4.8 in group B. The false negative rate was 0% in group A and 7.7% in group B. The sensitivity and specificity of SLN mapping was 100% in the submucosal group. The specificity of subserosal marking method was 100%, while the seínsitivity was 92.3%. Submucosal and subserosal marking methods were proven to be equivalent in detection rate, sensitivity and specificity based on 90% confidence interval of the ratio of indicators.

CONCLUSIONS

Our results suggest that sentinel lymph node mapping with blue dye alone represents a safety procedure and seems to be adaptable with high sensitivity and specificity, especially in cases of T1 and T2 tumors.

Identification of the lymphatic drainage pathways from the pancreatic head guided by indocyanine green fluorescence imaging during pancreaticoduodenectomy

AIMS

We identified the lymphatic drainage pathways from the pancreatic head guided by indocyanine green (ICG) fluorescence imaging to analyze optimal lymphadectomy for pancreatic cancer.

METHODS

The lymphatic pathways in 20 patients undergoing pancreaticoduodenectomy were analyzed. We injected ICG into the parenchyma in the anterior (n = 10) or posterior surface (n = 10) of the pancreas head and observed the intraoperative lymphatic flows by ICG fluorescence imaging.

RESULTS

The seven main lymphatic drainage pathways were identified: (1) along the anterior or posterior pancreaticoduodenal arcade, (2) running obliquely down behind the superior mesenteric vein (SMV), (3) reaching the left side of the superior mesenteric artery (SMA), (4) running longitudinally upward between the SMV and SMA, (5) along the middle colic artery toward the transverse colon, (6) reaching the paraaortic (PA) region, and (7) reaching the hepatoduodenal ligament. The lymphatic pathway reaching the left side of the SMA was observed in 4 patients (20%), while that reaching the PA region in 17 patients (85%). The mean time to reach around the SMA was longer than that to reach the PA region.

CONCLUSIONS

We found that several lymphatic drainage routes were observed from the pancreatic head, suggesting that a lymphadectomy around the SMA might have a similar oncological impact as that of the PA region.

A review of indocyanine green fluorescent imaging in surgery

The purpose of this paper is to give an overview of the recent surgical intraoperational applications of indocyanine green fluorescence imaging methods, the basics of the technology, and instrumentation used. Well over 200 papers describing this technique in clinical setting are reviewed. In addition to the surgical applications, other recent medical applications of ICG are briefly examined.

Indocyanine green injection for detecting sentinel nodes using color fluorescence camera in the laparoscopy-assisted gastrectomy

BACKGROUND AND AIM

We seek for the accurate and simple method for detecting sentinel nodes of gastric cancer which can be popularized in community hospitals. The indocyanine green (ICG) fluorescence-guided method is reported to be sensitive. However, the ordinal fluorescence cameras have gray scale imaging and require a dark room. We have developed a new device, Hyper Eye Medical System (HEMS) which can simultaneously detect color and near-infrared rays and can be used under room light. This study was planned to examine whether submucosal injection of 0.5 mL × 4 of 50 µg/mL ICG on the day before operation is the adequate administration for detecting sentinel nodes using HEMS in the gastric cancer surgery.

METHODS

The patients underwent gastrectomy for clinical T1a (mucosa)-T2 (muscularis propria) and clinical N0 were enrolled in the present study. As a preliminary trial, one case each of the ICG 25 and 100 µg/mL, injected on the day before operation and intraoperative injection, was examined. Then, 10 cases injected 50 µg/mL ICG on the day before operation were examined.

RESULTS

The ICG fluorescence of the patient injected 100 µg/mL was too intense and that of the patient injected 25 µg/mL was too faint. Sentinel lymph nodes were detected in all of 10 cases injected 50 µg/mL, the day before operation and number of sentinel lymph nodes per patient was 3.6 ± 2.1. Metastasis was observed in one case. All of ICG fluorescence-positive sentinel nodes were positive for the metastasis. In the patient who underwent intraoperative injection, sentinel lymphatic basins could be identified.

CONCLUSION

The present study shows that HEMS-guided abdominal surgery is feasible under room light. Submucosal injection of 0.5 mL × 4 of 50 µg/mL ICG on the day before operation is the adequate administration for detecting sentinel nodes using HEMS in the gastric cancer surgery.

Ultrastaging of colon cancer by sentinel node biopsy using fluorescence navigation with indocyanine green

PURPOSE

Lymph node status is the most important prognostic factor in colon cancer, but the role of sentinel lymph node biopsy (SLNB) as a tool for identification of micrometastatic disease and extraanatomical lymph nodes for adjuvant strategies and a tailored approach still remains unclear. Indocyanine green (ICG) fluorescence detection is a new method for SLNB allowing real-time lymphography and lymph node detection. This study was designed to evaluate the feasibility of fluorescence-guided sentinel lymph node detection in colon carcinoma.

METHODS

Twenty six patients with colon adenocarcinoma were prospectively included in this study. Intraoperatively, a peritumorous injection with a mean of 2.0 ml ICG was performed, followed by lymphatic mapping and SLNB. Clinical feasibility, detection rate, and sensitivity of the method were analyzed.

RESULTS

No adverse reactions occurred due to the injection of ICG. Overall, ICG fluorescence imaging identified 1.7 sentinel lymph node (SLN) in average in 25 out of 26 patients (detection rate, 96%). Metastatic involvement of the SLN was found in nine out of 11 nodal positive patients by conventional histopathology. The sensitivity of the method was 82% for colon carcinoma, respectively.

CONCLUSION

ICG fluorescence imaging is a new, feasible method for SLNB of colon carcinoma and enables ultrastaging with improved accuracy but with limited validity due to the small number of cases. One advantage of this technique is real-time visualization of lymphatic vessels and SLNB without radiation exposure. Further, larger series are necessary to analyze the role of fluorescence-guided SLNB for colon cancer.

Subtotal gastrectomy for gastric tube cancer after esophagectomy: a safe procedure preserving the proximal part of gastric tube based on intraoperative ICG blood flow evaluation

Recent improvements in the survival of patients after esophagectomy have led to an increase in the occurrence of gastric tube cancer (GTC). Total resection of the gastric tube with lymphadenectomy is a standard and reliable treatment for GTC, but problems may arise during or after surgery, such as laryngeal nerve injury, reduced selection of organs for reconstruction, and impaired swallowing function. We recently performed a less invasive procedure, subtotal gastrectomy with preservation of the upper region of the gastric tube, in two patients. In these patients, blood supply to the gastric tube was evaluated by indocyanine green fluorescence imaging. Blood flow was confirmed as passing from the remnant esophagus to the upper region of the gastric tube through the esophago-gastric anastomotic site by indocyanine green fluorescence imaging. Therefore, we resected the gastric tube while preserving the upper region of the gastric tube. There was no necrosis of the remnant gastric tube or anastomotic leakage postoperatively, and postoperative swallowing and eating functions were quite good in both patients. In summary, subtotal gastrectomy as a treatment for GTC is potentially safe, curative, and beneficial for the patient's quality of life.

Monomer adsorption of indocyanine green to gold nanoparticles

NIR-dye encoded gold nanoparticles (GNP) are rapidly emerging as contrast agents in many bio-imaging/sensing applications. The coding process is usually carried out without control or a clear understanding of the metal-liquid interface properties which, in contrast, are critical in determining the type and extension of dye-metal interaction. In this paper, we investigated the effect of gold surface composition on the adsorption of indocyanine green (ICG) on GNP, simulating the surface conditions of gold nanorods on citrate-capped gold nanospheres. These substrates allowed a careful control of the metal-liquid interface composition and, thus, detailed absorption and fluorescence concentration studies of the effects of each individual chemical in the colloidal solution (i.e. bromide anions, cetyl trimethylammonium ions and Ag(+) ions) on the ICG-gold interaction. This study reveals the drastic effect that these experimental parameters can have on the ICG adsorption on GNP.

Value of sentinel lymph node mapping using a blue dye-only method in gastric cancer: a single-center experience from North-East Hungary

BACKGROUND

Forty percent of patients with gastric cancer have unnecessarily extended lymph node dissections with higher rates of morbidity and mortality than those in non-extended procedures. Successful sentinel lymph node (SLN) mapping may help to reduce the number of extended lymphadenectomies.

METHODS

SLN mapping was investigated by a blue dye-only method in patients with gastric cancer. The first cohort of patients (n = 16) were marked submucosally by an endoscopist and in the second cohort of patients (n = 23) a subserosal injection was performed by the surgeon.

RESULTS

Thirty-nine patients, all Caucasians, underwent gastric resection or total gastrectomy with SLN biopsy using patent blue-dye mapping and modified D2 lymphadenectomy. The mapping procedure and the lymphadenectomy were supervised by the same surgeon. A total of 770 lymph nodes were removed and examined. The mean number of blue nodes was 4.3 per patient. In 22/23 cases at least one SLN showed tumor involvement. The sensitivity of SLN mapping was 95.7%, the false-negative rate was 4.3%, and the specificity was 100%. The negative predictive value was 93.8% and the positive predictive value was 100%. In cases of T1 and T2 tumors the sensitivity was 100%. We found the two marking methods (submucosal vs. subserosal) to be equivalent and there was no side-effect of the blue-dye mapping.

CONCLUSIONS

Our results suggest that SLN mapping with blue dye alone represents a safe procedure that seems to be adaptable for non-obese patients undergoing open surgery for gastric cancer in the Eastern European region. The procedure has high sensitivity and specificity, especially in cases of T1 and T2 tumors.

Sentinel lymph node biopsy for gastric cancer: Where do we stand?

Development of sentinel node navigation surgery (SNNS) and advances in minimally invasive surgical techniques have greatly shaped the modern day approach to gastric cancer surgery. An extensive body of knowledge now exists on this type of clinical application but is principally composed of single institute studies. Certain dye tracers, such as isosulfan blue or patent blue violet, have been widely utilized with a notable amount of success; however, indocyanine green is gaining popularity. The double tracer method, a synchronized use of dye and radio-isotope tracers, appears to be superior to any of the dyes alone. In the meantime, the concepts of infrared ray electronic endoscopy, florescence imaging, nanoparticles and near-infrared technology are emerging as particularly promising alternative techniques. Hematoxylin and eosin staining remains the main method for the detection of sentinel lymph node (SLN) metastases. Several specialized centers have begun to employ immunohistochemical staining for this type of clinical analysis but the equipment costs involving the associated ultra-rapid processing systems is limiting its widespread application. Laparoscopic function-preserving resection of primary tumor from the stomach in conjunction with lymphatic basin dissection navigated by SLN identification represents the current paramount of SNNS for early gastric cancer. Patients with cT3 stage or higher still require standard D₂ dissection.

The clinical use of indocyanine green as a near-infrared fluorescent contrast agent for image-guided oncologic surgery

Optical imaging using near-infrared (NIR) fluorescence provides new prospects for general and oncologic surgery. ICG is currently utilised in NIR fluorescence cancer-related surgery for three indications: sentinel lymph node (SLN) mapping, intraoperative identification of solid tumours, and angiography during reconstructive surgery. Therefore, understanding its advantages and limitations is of significant importance. Although non-targeted and non-conjugatable, ICG appears to be laying the foundation for more widespread use of NIR fluorescence-guided surgery.

Real-time imaging of the lymphatic channels and sentinel lymph nodes of the stomach using contrast-enhanced ultrasonography with Sonazoid in a porcine model

The contrast-enhanced ultrasound (CEUS)-guided method in combination with Sonazoid has not been clinically or experimentally evaluated with regard to its use for identifying sentinel lymph node (SLN) in the stomach. Therefore, we attempted to evaluate the usefulness of the CEUS-guided method with Sonazoid for imaging of the lymphatic channels and SLN of the stomach in a porcine model by comparing it with the conventional Evans blue dye-guided method. Twenty-eight 2 to 3-month-old swine weighing 17-30 kg were used in this experiment. Anesthesia was maintained with 2.0-3.0% isoflurane/O(2) inhalation. Sonazoid was injected into the intra- and sub-mucosal layers of the stomach. The intragastric or transcutaneous CEUS-guided method was used to identify the lymphatic channels and SLN of the stomach. Contrast imaging using the CEUS-guided method with Sonazoid enabled us to produce clear images of the afferent lymph vessel and SLN of the stomach until 2 h after the injection of Sonazoid. In addition, intranodal flow of the microbubble agent could be clearly identified using tissue linear harmonic images of the SLN. The SLN detection rate was not significantly different between the CEUS- and dye-guided methods. However, the Evans blue dye flowed out quickly (≈ 15 min after the injection) through the true SLN into the next LN of stomach. In conclusion, the use of the CEUS-guided method with Sonazoid might be the most useful clinical procedure for producing real-time images of the SLN of the stomach, and the linear harmonic images are also useful for evaluating intranodal structure within the SLN.

Sentinel lymph node biopsy using intraoperative indocyanine green fluorescence imaging navigated with preoperative CT lymphography for superficial esophageal cancer

BACKGROUND

The sentinel lymph node (SLN) concept has been gaining attention for gastrointestinal neoplasms but remains controversial for esophageal cancer. This study evaluated the feasibility of SLN identification using intraoperative indocyanine green (ICG) fluorescence imaging (IGFI) navigated by preoperative computed tomographic lymphography (CTLG) to treat superficial esophageal cancer.

METHODS

Subjects comprised 20 patients clinically diagnosed with superficial esophageal cancer. Five minutes after endoscopic submucosal injection of iopamidol around the primary lesion using a four-quadrant injection pattern with a 23-gauge endoscopic injection sclerotherapy needle, three-dimensional multidetector computed tomography was performed to identify SLNs and lymphatic routes. ICG solution was injected intraoperatively around the tumor. Fluorescence imaging was obtained by infrared ray electronic endoscopy. Thoracoscope-assisted standard radical esophagectomy with lymphadenectomy was performed to confirm fluorescent lymph nodes detected by CTLG.

RESULTS

Lymphatic vessels and SLNs were identified preoperatively using CTLG in all cases. Intraoperative detection rates were 100% using CTLG and 95% using IGFI. Lymph node metastases were found in four cases, including one false-negative case with SLNs occupied by bulky metastatic tumor that were not enhanced with both methods. The other 19 cases, including three cases of metastatic lymph nodes, were accurately identified by both procedures.

CONCLUSIONS

Preoperative CTLG visualized the correct number and site of SLNs in surrounding anatomy during routine computed tomography to evaluate distant metastases. Referring to CTLG, SLNs were identified using IGFI, resulting in successful SLN navigation and saving time and cost. This method appears clinically applicable as a less-invasive method for treating superficial esophageal cancer.

Is the sentinel node biopsy clinically applicable for limited lymphadenectomy and modified gastric resection in gastric cancer? A meta-analysis of feasibility studies

BACKGROUND

Sentinel node biopsies (SNBs) have been clinically applied in melanoma and breast cancer for limited lymphadenectomy. However, the use of SNB remains controversial in gastric cancer due to unsatisfactory sensitivity and variability. This meta-analysis was performed to determine the sensitivity of SNB in gastric cancer and to identify factors that improve its sensitivity.

METHODS

Feasibility studies on SNB in gastric cancer were searched for from 2001 to 2009 in Pubmed, Cochrane, and Embase. Forty-six reports, which included 2,684 patients, were found. Estimated sensitivities, detection rates, and negative (NPV), and positive predictive values (PPV) were calculated using a random effects model. Inter-study heterogeneity, meta-regression, and subgroup analysis for sensitivity was performed.

RESULTS

The estimated sensitivity, detection rate, NPV, and PPV were 87.8%, 97.5%, 91.8%, and 38.0%, respectively, with significant inter-study heterogeneity (P < 0.0001). However, no significant contributor to heterogeneity was identified. By subgroup analysis, sensitivity was found to depend significantly on the number of SNs harvested.

CONCLUSIONS

SNB in gastric cancer is probably not clinically applicable for limited lymphadenectomy due its unsatisfactory sensitivity and heterogeneity between practicing surgeons. To improve sensitivity, more than four SNs should be harvested, and a tumor specific SNB method should be developed.

Enhancement of the photostability and retention time of indocyanine green in sentinel lymph node mapping by anionic polyelectrolytes

Sentinel lymph node (SLN) biopsy techniques have been widely used in the diagnosis of cancer metastasis because lymph node metastasis is one of the most important prognostic signs. Indocyanine green (ICG) has potential application as a molecular imaging probe for SLN mapping due to its fluorescent properties emitting in the near-infrared (NIR) region, where light transmission through biological tissue is maximized. However, its low photostability in an aqueous solution at the physiological temperature and its rapid diffusion behavior through SLN into the second lymph node have limited its wide use in real clinical fields. In this study, we developed a new NIR imaging contrast system consisting of ICG and poly (γ-glutamic acid) (γ-PGA) polymers for efficient sentinel lymph node mapping. By a combination of clinically used ICG and the biocompatible anionic polyelectrolyte, γ-PGA, the photostabilities of aqueous ICG solutions at room and body temperatures were drastically enhanced. When the ICG/γ-PGA complex was injected subcutaneously into the front paw of a mouse, it entered the lymphatics and migrated to the axillary sentinel lymph node (SLN) within 2 min. Furthermore, the NIR fluorescent signal intensity and retention time of ICG/γ-PGA complex in lymph node were superior to those of ICG only. In addition, a histofluorescentstudy of the SLN resected under NIR imaging revealed that ICG and γ-PGA were co-localized in the lymph node.Taken together, the experimental results on the enhanced photostability and retention time of the ICG/γ-PGA complex provide strong evidence that it has promising potential for improved sentinel lymph node mapping.

Combined intraoperative use of contrast-enhanced ultrasonography imaging using a sonazoid and fluorescence navigation system with indocyanine green during anatomical hepatectomy

PURPOSE

The clear demarcation line is ideal for real-time surgical navigation imaging during hepatectomy.

METHODS

The study population was comprised of 22 patients with moderate liver cirrhosis scheduled to undergo an anatomical liver resection for the treatment of hepatocellular carcinoma. This study set out to assess the clinical value of the concomitant intra-operative use of contrast-enhanced intra-operative ultrasound using Sonazoid™, and a fluorescence navigation system (PDE) with ICG, as a novel tool for patients undergoing an anatomical liver resection.

RESULTS

Following portal pedicle ligation for anatomical resection, 2 min after injection of ICG, the segments to be resected were detected as a negative-brightness area using PDE fluorescence. Sonazoid™ administration provides a parenchymal transectional line, as the margin of a loss of blood flow shows a hypo-enhanced image, and the resectional line of the parenchyma can be confirmed by CE-IOUS. Although the demarcation line of the liver surface after the portal pedicle ligation was apparent in 17 patients, the resection line using PDE was clearly detected in all 22 patients (p < 0.018).

CONCLUSIONS

The combined use of these methods is therefore considered to be useful and safe for surgeons, as an additional tool for performing a liver resection.

Tracer agents for the detection of sentinel lymph nodes in breast cancer: current concerns and directions for the future

Tracer agents play a central role in axillary lymphatic mapping for sentinel node identification during breast cancer surgery. This article reviews the data concerning safety, efficacy, and availability of tracers currently in use. Alternate tracer materials are introduced, with review of the current literature.

Treatment strategy for early gastric cancer

Gastric cancer ranks the second leading cause of cancer-specific mortality worldwide. With a poor prognosis, 5-year survival rate of gastric cancer is less than 20%-25% in the USA, Europe, and China [1]. However, early gastric cancer(EGC) offers an excellent (over 90%) chance of cure based on surgical resection [2]. As the increasing detection of EGC, more treatment options have been developed both curatively and minimally invasively to maintain a good quality of life(QOL). One of the advanced therapeutic techniques is endoscopic dissection. Improvements in surgical treatment include minimizing lymph node dissection, reconstruction methods, laparoscopy-assisted surgery, and sentinel node navigation surgery(SNNS) [3]. With technological advances, even Natural Orifice Transluminal Endoscopy Surgery (NOTES) and robotic surgery are expected to represent the next revolution [4]. However, there still remains much dispute among these treatments, which arouses further clinical trials to verify. Update of the treatments, controversial indications, prognosis and current strategies for EGC are discussed in this review.

A novel insight of sentinel lymph node concept based on 1-3 positive nodes in patients with pT1-2 gastric cancer

Background

Sentinel node (SN) biopsy has been practiced in gastric cancer in recent years, and many studies focused on the distribution of solitary lymph node metastasis (SLM) to assess the pattern of SN. In fact, there is usually more than one SN existing in gastric cancer. The distribution of SNs needs to be further re-evaluated.

Methods

A total of 289 patients in pT1-2 stage with 1-3 positive nodes confined to same compartment were included in this study with informed consents. The primary lesion was solitary (≤ 5.0 cm in diameter) and D2 or D3 lymph node dissection had been performed. The location of metastatic lymph nodes was analyzed retrospectively.

Results

Most positive nodes occurred in N1 compartment, with frequency of 79.6% to 85.7% based on site of tumor. In the lower third of stomach, no. 6 was the most common metastatic site and no. 3 was the second; the order was reversed for SLM. With increasing depth of tumor invasion, a progressively augmented nodal involvement was shown. Nearly a half appeared transverse metastasis when the tumor located at the lesser or greater curvature. Among skip metastasis, no. 7, 8a, 9 and 11p were the most common metastatic sites and the prognosis was as similar as that of patients with N1 involved only.

Conclusions

The 1-3 positive nodes in the same compartment should be possible SNs, and most of which are restricted in N1 in pT1-2 gastric cancer. Transversal and 2 stations lymph node metastasis are common.

Usefulness of blood supply visualization by indocyanine green fluorescence for reconstruction during esophagectomy

BACKGROUND: Adequate blood supply for the reconstructed organ is important for safe esophagogastric anastomosis during esophagectomy. Recently, indocyanine green (ICG) has been used for visualization of the blood supply when anastomosis is performed in vascular surgery. To visualize the blood supply for reconstruction, we employed ICG fluorescence during esophagectomy. METHODS: From August 2008, 40 patients received cervical or thoracic esophagectomy. They consisted of 33 patients having esophagectomy for thoracic esophageal cancer, 3 being treated for cervical esophageal cancer, and 4 with double cancer of the thoracic and cervical regions. Before and after pulling up the reconstructed organ, 2.5 mg of ICG was injected as a bolus. Then ICG fluorescence was detected by a camera and recorded. RESULTS: ICG fluorescence was easily detected in all patients at 1 min after injection. The vascular network was well visualized in the gastric wall, colonic grafts, and free jejunal grafts. In five patients, we also performed anastomosis between the short gastric vein and the external cervical vein or superficial cervical vein. The intraoperative and postoperative course of all patients was uneventful apart from three anastomotic leakages. CONCLUSIONS: ICG fluorescence can be employed to evaluate the blood supply to reconstructed organs and can be useful in selecting the patients who do not need additional vessel anastomosis. However, anastomotic leakage was not reduced, so the microcirculation detected by ICG fluorescence did not necessarily provide appropriate blood supply for a viable anastomosis.

Segmental gastrectomy with radical lymph node dissection for early gastric cancer

AIM: To describe a new surgical technique and evaluate the early results of segmental gastrectomy (SG) with modified D2 lymph node (LN) dissection for early gastric cancer (EGC).

METHODS: Fourteen patients with EGC underwent SG with modified D2 dissection from 2006 to 2008. Their operative results and postoperative courses were compared with those of 17 patients who had distal gastrectomy (DG) for EGC during the same period.

RESULTS: Operating time, blood loss, and hospital stay were similar between the 2 groups. Postoperative complications developed significantly more frequently in the DG group than in the SG group. Mean number of dissected LNs per each station in the SG group was comparable with that in the DG group. Postoperative recovery of body weight was significantly better in the SG group than in the DG group. The incidence of reflux esophagitis and gastritis after surgery was less frequent in the SG group than in the DG group.

CONCLUSION: SG with modified D2 LN dissection may be a new function-preserving gastrectomy that is feasible for treatment of EGC with possible LN involvement.