Search

Background: Indocyanine green (ICG), an agent for measuring liver function, becomes fluorescent under near-infrared (NIR) light after binding to serum proteins. Hepatocellular carcinoma (HCC) with a deposit of preoperatively administered ICG becomes clearly detectable under ICG fluorography; however, it remains unclear whether this detection method is always reliable. This case series study was designed to clarify the reliability of this method., Methods: ICG (0.5 mg/kg) was injected from the 3rd to 28th preoperative day to evaluate hepatic function in 58 patients with HCCs. Preoperative imaging modalities identified 76 HCC foci. The operative fields and resected specimens were observed with an NIR camera system. Preoperatively detected lesions and lesions newly detected by the ICG fluorography were histologically investigated., Results: ICG fluorography identified 73 of 76 preoperatively diagnosed HCC lesions. Intraoperative ICG fluorography visualized 47 lesions in 40 patients. The other 26 lesions showing emission were found in the sectioned specimens under NIR observation. Other than preoperatively diagnosed foci, ICG fluorography visualized 35 new lesions, including 6 HCCs, 2 dysplastic nodules and 27 non-neoplastic lesions, such as bile plugs and cysts. The sensitivity of ICG fluorography for HCCs was 96% and its positive predictive value was 71.5%., Conclusions: Indocyanine green fluorography is useful to detect HCCs; however, attention should be paid to the fact that HCCs may be occasionally overlooked by this imaging method and that lesions detected by this method are not always neoplastic lesions.

Objectives: Lymph transportation through the body is partly controlled by the intrinsic pumping of lymphatic vessels. Although an understanding of this process is important for medical application, little is currently known because it is difficult to measure. Here, we introduce an easy, safe, and cost-effective technique for measuring lymphatic pumping in leg superficial lymphatic vessels. Readings obtained with this technique were compared with values obtained with dynamic lymphoscintigraphy. Differences in lymphatic pumping between healthy volunteers and patients with lymphedema were also investigated., Methods: Indocyanine green (ICG) fluorescence lymphography was performed by subcutaneously injecting 0.3 mL of ICG (0.5%) into the dorsum of the foot. Real-time fluorescence images of lymph propulsion were obtained with an infrared-light camera system with the individual supine or sitting. A custom-made transparent sphygmomanometer cuff was wrapped around the lower leg and connected to a standard mercury sphygmomanometer. The cuff was inflated to 60 mm Hg and then gradually deflated at 5-minute intervals to lower the pressure by 10-mm Hg steps until the fluorescence contrast agent exceeded the upper border of the cuff, indicating that the lymphatic contraction had overcome the cuff pressure. Lymph pumping pressure (P(pump)) was defined as the value of the cuff pressure when the contrast agent exceeded the upper border of the cuff. We measured P(pump) among healthy volunteers who maintained a supine position and compared these values with measurements obtained from lymphoscintigraphy. P(pump) values while sitting were also compared between 30 legs from healthy volunteers and 30 legs from lymphedematous patients., Results: Among healthy, supine participants, P(pump) was 25.2 ± 16.7 mm Hg (mean ± standard deviation [SD]) when measured by ICG fluorescence lymphography. These values were significantly correlated with values taken using dynamic lymphoscintigraphy (r(2) = 0.54, p < .01), while 2 SDs of the mean were approximately 20 mm Hg, suggesting a substantial disagreement between the two methods (Bland-Altman plots). In the comparison of seated measurements, readings for healthy participants (P(pump) = 29.3 ± 16.0) were higher than those for lymphedematous participants (13.2 ± 14.9)., Conclusion: ICG fluorescence is an accurate-as well as a safe, easy, and economical-method of measuring lymphatic pumping. Therefore, it may develop as a vital tool for diagnosing lymphatic malfunctions even when they are only in their formative stages. Studies that use this technique may increase our knowledge of the lymphatic system as a whole, allowing us to develop better treatments for lymphatic disorders., (Copyright © 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Bile leak remains a serious complication after hepatectomy. The conventional leak test by intrabiliary injection of normal saline solution is not sensitive. The authors present a new bile leak test using indocyanine green (ICG) fluorescence. After hepatic transection, ICG solution (.05 mg/mL) was intrabiliarily injected through a transcystic tube under distal common bile duct clamping, and fluorescent images were visualized using an infrared camera system. The ICG leak test was performed in 27 patients undergoing hepatectomy without biliary reconstruction. Bile leaks were intraoperatively found in 8 patients and fixed, resulting in no postoperative leaks. There was no adverse reaction to ICG. In contrast, postoperative bile leaks occurred in 2 of 32 patients who received the conventional leak test with normal saline solution between April 2007 and March 2008. The new bile leak test by ICG fluorography is useful to prevent postoperative bile leak., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

Intraoperative indocyanine green (ICG) lymphography was performed on a 62-year-old man, who was diagnosed to have chylothorax after an esophagectomy for esophageal cancer. After exploration of the thorax, a slowly increasing effusion was identified in the mediastinal space above the diaphragm, but the exact site of the lymph fistula could not be identified. By injecting 1.5 ml of ICG subcutaneously at the bilateral inguinal region, fluorescence images of the lymph flow in the thoracic cavity were obtained using a near-infrared camera system. The detected leakage point was sutured and the chyle ooze stopped. The postoperative course was uneventful. The patient was discharged on the 16th postoperative day. This is the first report using ICG fluorescence lymphography for the successful intraoperative detection of the exact site of a fistula causing chylothorax.

Objectives: A new diagnostic imaging technique that can assess lymph function is needed as a screening test in daily practice. This study assessed the use of indocyanine green (ICG) fluorescence lymphography in subjects without leg oedema., Methods: 0.3ml of ICG (0.5 %) was injected subcutaneously at the dorsum of the foot. Subsequently, the movement of ICG dye from the injection site to the groin was traced by visualizing its fluorescence signal with an infrared light camera. The time for the dye to reach the knee and groin were measured (Transit time to knee: TT(K), Transit time to groin: TT(G)). TT(G) was measured while standing, lying at a supine position, standing with massage, and sitting while using a cycle ergometer exercise at an intensity of 50W at 50rpm in ten healthy volunteers at intervals of 14 days., Results: Mean TT(G) during standing was 357+/-289 and 653+/-564 seconds for the right and left legs respectively. Compared to TT(G) in the standing position, all other conditions shortened TT(G). In another seventeen subjects without leg oedema, we compared transit time obtained with ICG fluorescence lymphography to that with dynamic lymphoscintigraphy. A significant correlation between transit time measured with ICG lymphography and dynamic lymphoscintigraphy was identified (r(2)=0.64, p<0.01)., Conclusions: ICG fluorescence lymphography has the potential to become an alternative lymphatic imaging technique to assess lymph function.

Objective: To introduce our preliminary experience with indocyanine green (ICG) fluorescence angiography for the assessment of lower leg bypasses., Methods: 1ml of 0.5% indocyanine green was intravenously injected in 9 patients with PAD who underwent paramalleolar artery bypass using saphenous vein grafts. A newly developed near-infrared camera system (PDE; Hamamatsu Photonics K.K. Hamamatsu, Japan) was used for this study., Results: ICG fluorescence angiography was performed without any adverse events. Fluorescence images of ICG angiography could be viewed as real-time images of the angiography in eight patients, while one patient underwent graft revision with the absence of fluorescence in ICG angiography., Conclusion: ICG fluorescence angiography is clinically feasible and may help surgeons assess the quality of lower leg bypasses.

Background: Lymphoscintigraphy has largely been performed to diagnose lymphedema. It is, however a time-consuming and expensive technique, which has not been covered by Japanese medical insurance since the year 2002. In this report we introduce a new imaging technique of fluorescent lymphography to diagnose lymphedema., Methods: Fluorescence images of subcutaneous lymphatic drainage after subcutaneous injection of indocyanine green (ICG) at the foot were obtained using a newly developed near-infrared camera system. ICG fluorescent lymphography was performed in 12 patients with secondary lymphedema and 10 healthy volunteers. The 12 patients were diagnosed with secondary lymphedema according to the medical history and lymphoscintigram, of which 11 had a history of hysterectomy with extended lymph node dissection and local radiation therapy for uterine cancer. Lymphedema developed in one patient after femorotibial artery bypass for peripheral artery occlusive disease., Results: Four abnormal fluorescent patterns of the lymph drainage were observed in lymphedema: dermal backflow (an abnormal filling of the lymph capillaries), extended fluorescent signal at the dorsum and plantar region of the foot, dilated lymph channels with proximal obliteration, and diffuse glittering of fluorescent signals with scattered twinkling of the dye. Continuous lymph channels from the injection site of the foot to the groin were observed along the medial aspect of thigh in healthy subjects., Conclusion: ICG fluorescence lymphography is safe, simple, and minimally invasive. The device is portable and easy to use. The technique may be useful in clinical practice to identify presence of lymphatic disorder.