Superior lymph node harvest by fluorescent lymphography during minimally invasive gastrectomy for gastric cancer patients with high body mass index.

BACKGROUND: Fluorescent lymphography (FL) using indocyanine green (ICG) allows for the visualization of all draining lymph nodes (LNs), thereby increasing LN retrieval. However, no studies have assessed the efficacy of FL in high body mass index (BMI) gastric cancer patients, even as LN yield decreases with increasing BMI in gastrectomy. This study aimed to investigate the influence of FL on LN retrieval in high BMI gastric cancer patients. METHODS: Gastric cancer patients who underwent laparoscopic or robotic gastrectomies from 2013 to 2021 were included. Patients were classified into two groups, with FL (FL group) or without FL (non-FL group). The effect of FL on LN retrieval was assessed by BMI. Inverse probability of treatment weighting (IPTW) was used to ensure comparability between groups. RESULTS: Retrieved LN number decreased as BMI increased regardless of FL application (P < 0.001). According to the IPTW analysis, the mean retrieved LN number was significantly higher in the FL group (48.4 ± 18.5) than in the non-FL group (39.8 ± 16.3, P < 0.001), irrespective of BMI. The FL group exhibited a significantly higher proportion of patients with 16 or more LNs (99.5%) than the non-FL group (98.1%, P < 0.001). The FL group also had a significantly higher proportion of patients with 30 or more LNs (86.6%) than the non-FL group (72.2%, P < 0.001). In both the normal and high-BMI patients, the FL group had a significantly larger percentage of patients with a higher nodal classification than the non-FL group. CONCLUSION: FL resulted in more LN retrieval, even in high BMI patients. FL ensures accurate staging by maintaining the appropriate retrieved LN number in high BMI gastric cancer patients.

Assessment of indocyanine green fluorescence lymphography on lymphadenectomy during minimally invasive gastric cancer surgery: a systematic review and meta-analysis.

BACKGROUND: In recent years, indocyanine green fluorescence lymphography has been introduced for lymphatic mapping in gastric cancer surgery. The aim of this study was to investigate the efficacy of ICGFL in lymph node dissection during minimally invasive surgery for gastric cancer. METHODS: A systematic review of electronic databases including PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Infrastructure was performed from the inception to January 2021 for all studies comparing ICGFL with non-ICGFL in GC patients undergoing minimal access gastrectomy. The primary outcome was the total number of harvested lymph nodes. The secondary endpoints were the number of metastatic LNs, operative time, estimated blood loss, and postoperative complications. The registration number of this protocol is PROSPERO CRD42020203443. RESULTS: A total of 13 studies including 1882 participants were included. In this meta-analysis, the use of ICGFL was associated with a higher number of harvested LNs (40.33 vs. 33.40; MD = 6.93; 95%CI: 4.28 to 9.58; P < 0.0001; I2 = 86%). No significant difference was found between the ICGFL and control groups in terms of metastatic LNs (2.63 vs. 2.42; MD = 0.21; 95%CI: -0.46 to 0.87; P = 0.54; I2 = 0%). In addition, the use of ICGFL could be safely performed without increasing the operative time (P = 0.49), estimated blood loss (P = 0.26) and postoperative complications (P = 0.54). CONCLUSION: The use of ICGFL may be a useful tool facilitating complete lymph node dissection during minimally invasive GC resection. However, more high-quality RCTs with large sample size are needed to validate this issue.

Fluorescent lymphography during minimally invasive total gastrectomy for gastric cancer: an effective technique for splenic hilar lymph node dissection.

BACKGROUND: Fluorescent lymphography is an excellent technique for complete lymph node dissection during minimally invasive surgery for gastric cancer. This study aimed to evaluate the role of fluorescent lymphography in splenic hilar lymph node dissection during minimally invasive total gastrectomy. METHODS: We retrospectively analyzed 168 gastric cancer patients who underwent minimally invasive total gastrectomy with D2 + No. 10 lymph node dissection from 2013 to 2018. Fluorescent lymphography was used whenever it is possible. However, when near-infrared imaging system and endoscopic indocyanine green injection were not available, we performed surgery without fluorescent lymphography. A total of 74 patients underwent surgery with fluorescent lymphography (FL group) and 94 underwent surgery without it (non-FL group). Perioperative and long-term outcomes including the number of retrieved lymph nodes at each nodal station were compared between groups. RESULTS: The median number of retrieved lymph nodes at the splenic hilum was larger in the FL group {2.5 [Interquartile range (IQR), 1-5]} than in the non-FL group [1 (IQR, 1-3); P = 0.012]. The negative predictive value of fluorescent lymphography for lymph node metastasis at the splenic hilum was 97.1%, although the sensitivity was 66.7%. The overall survival (FL: 96.9% vs. non-FL: 88.9%; P = 0.334) and relapse-free survival (FL: 90.5% vs. non-FL: 65.5%; P = 0.054) were higher in the FL group, although there were no statistical differences. However, among the patients without lymph node metastasis, the relapse-free survival was significantly higher in the FL group (100%) than in the non-FL group (67.1%; P = 0.017). CONCLUSIONS: Fluorescent lymphography is an effective tool for complete lymph node dissection at the splenic hilum. Moreover, it may help select patients who do not need splenic hilar lymph node dissection during a total gastrectomy.

Fluorescent Lymphography-Guided Lymphadenectomy during Minimally Invasive Completion Total Gastrectomy for Remnant Gastric Cancer Patients.

No study has evaluated fluorescent lymphography for lymphadenectomy in remnant gastric cancer (RGC). This study aimed to assess the clinical application of fluorescent lymphography in minimally invasive completion total gastrectomy for RGC. Patients who had undergone minimally invasive completion total gastrectomy for RGC from 2013 to 2020 were retrospectively reviewed. The perioperative outcomes and long-term prognosis were compared between patients who had undergone minimally invasive completion total gastrectomy with fluorescent lymphography (the FL group) and those without fluorescent lymphography (the non-FL group). The FL group comprised 32 patients, and the non-FL group comprised 36 patients. FL visualized lymphatics in all 32 patients without complications related to the fluorescent injection. The median number [the interquartile range] of LN retrieval was significantly higher in the FL group (17 [9.3-23.5]) than in the non-FL group (12.5 [4-17.8]); p = 0.016). The sensitivity of fluorescent lymphography in detecting metastatic LN stations was 75%, and the negative predictive value was 96.9% in the FL group. The overall relapse-free survivals were comparable between the groups (p = 0.833 and p = 0.524, respectively). FL is an effective tool to perform a more thorough lymphadenectomy during minimally invasive completion total gastrectomy for RGC. Using FL in RGC surgery may improve surgical quality and proper staging.

HAMAMATSU-ICG study: Protocol for a phase III, multicentre, single-arm study to assess the usefulness of indocyanine green fluorescent lymphography in assessing secondary lymphoedema.

INTRODUCTION: Secondary lymphoedema of the extremities is an important quality-of-life issue for patients who were treated for their malignancies. Indocyanine green (ICG) fluorescent lymphography may be helpful for assessing lymphoedema and for planning lymphaticovenular anastomosis (LVA). The objective of the present clinical trial is to confirm whether or not ICG fluorescent lymphography using the near-infrared monitoring camera is useful for assessing the indication for LVA, for the identification of the lymphatic vessels before the conduct of LVA, and for the confirmation of the patency of the anastomosis site during surgery. METHODS AND ANALYSIS: This trial is a phase III, multicentre, single-arm, open-label clinical trial to assess the efficacy and safety of ICG fluorescent lymphography when assessing and treating lymphoedema of patients with secondary lymphoedema who are under consideration for LVA. The primary endpoint is the identification rate of the lymphatic vessels at the incision site based on ICG fluorescent lymphograms obtained before surgery. The secondary endpoints are 1) the sensitivity and specificity of dermal back flow determined by ICG fluorescent lymphography as compared with 99mTc lymphoscintigraphy-one of the standard diagnostic methods and 2) the usefulness of ICG fluorescent lymphography when confirming the patency of the anastomosis site after LVA. ETHICS AND DISSEMINATION: The protocol for the study was approved by the Institutional Review Board of each institution. The trial was filed for and registered at the Pharmaceuticals and Medical Devices Agency in Japan. The trial is currently on-going and is scheduled to end in June 2020. TRIAL REGISTRATION NUMBER: jRCT2031190064; Pre-results.

Correlation of L-Dex Bioimpedance Spectroscopy with Limb Volume and Lymphatic Function in Lymphedema.

Background: Bioimpedance spectroscopy (BIS) is an established tool for the measurement of extracellular fluid in lymphedema. This study assesses the validity of BIS measurements using the l-Dex® for evaluating the effectiveness of interventions to treat lymphedema. Measurements are correlated with limb volume, assessment of pitting edema, physiologic measures of lymphatic function, and response to surgical intervention. Three l-Dex BIS metrics are compared. Methods and Results: This retrospective study of prospectively collected data identified consecutive patients with lymphedema. l-Dex BIS measurements, limb volume measurements using perometry, transport index (TI) evaluation using radioisotope lymphoscintigraphy, staging using indocyanine green (ICG) fluorescent lymphography, and clinical evaluation of degree of pitting edema were compared to examine correlations. l-Dex BIS metrics included the l-Dex ratio, absolute difference between the affected and unaffected extremities, and their unadjusted ratio. The study included 26 patients with 70 sets of evaluations. There were significant correlations between the l-Dex ratio and limb volume ratio (LVR) using perometry, the degree of pitting edema, TI evaluation using lymphoscintigraphy, and staging using ICG lymphography. Of the l-Dex BIS metrics, the l-Dex ratio correlated most closely with all measures (ρ = 0.71-0.94, p < 0.0001). Following complete decongestive therapy, the mean decrease in the l-Dex ratio was 48.3% whereas the corresponding mean reduction in limb volume was 13.8% (ρ = 0.19; p = 0.65); subsequent physiological surgery including lymphovenous bypass and vascularized lymph node transfer resulted in an average reduction in l-Dex ratio of 36.1% and mean limb volume reduction of 25.2% (ρ = 0.38; p = 0.27). Conclusions: L-Dex BIS measurements demonstrate face, construct, and criterion validity, and correlate with clinical assessment, LVR, physiologic measures of lymphatic function, and response to conservative and surgical intervention. The L-Dex ratio correlates most closely with all measures and is the recommended metric when using BIS.

Novel thoracoscopic navigation surgery for neonatal chylothorax using indocyanine-green fluorescent lymphography.

BACKGROUND: Postoperative chylothorax after surgery for esophageal atresia/tracheoesophageal fistula (TEF) is a rare but serious complication, especially in neonates. This study aimed to identify the thoracic duct and ligate chylous leakage sites, using thoracoscopic navigation of an indocyanine-green (ICG)-based near-infrared (NIR) fluorescence imaging system. METHODS: From November 2014 to April 2017, thoracoscopic intraoperative ICG-NIR imaging was performed in 10 newborns (11 surgeries) with first TEF operation or with persistent postoperative chylothorax after TEF operation. NIR imaging was performed 1h after an inter-toe injection of ICG. Thoracoscopic ligations against the NIR-detected leakage sites were performed with sutures. RESULTS: The thoracic duct or lymphatic leakage was directly visualized in each patient. In 8 surgeries with first thoracoscopic TEF operation, one case had suspected minor chylous leakage without postoperative chylothorax. Another case with no chylous leakage at the first operation resulted in chylothorax at postoperative day 11. In three neonates with postoperative chylothorax, leakage points were detected near the ablation site of the azygos vein during the first operation. These points were properly ligated, and postoperative chylous leakage ceased with no adverse events. CONCLUSIONS: Thoracoscopic ICG-NIR imaging encourages the repair of refractory chylothorax and seems reliable. LEVEL OF EVIDENCE: IV.