Imaging mass spectrometry reveals unique lipid distribution in primary varicose veins.

BACKGROUND: The lipid metabolism of varicose veins (VVs) remains unknown. To elucidate the pathogenesis of VV, we utilized the novel technique of imaging mass spectrometry (IMS). MATERIALS AND METHODS: We obtained VV tissues from 10 limbs of 10 VV patients who underwent great saphenous vein stripping. As control vein samples, we harvested segmental vein tissues from 6 limbs of 6 patients with peripheral artery occlusive disease who underwent infra-inguinal bypass with reversed saphenous vein grafting. To identify the localisation of lipid molecules in the VV tissues, we performed matrix-assisted laser desorption/ionization IMS (MALDI-IMS). We also performed MS/MS analyses to identify the structure of each molecule. RESULTS: We obtained mass spectra directly from control vein tissues and VV tissues and found a unique localisation of lipid molecules in the VV tissues. We localised lysophosphatidylcholine (LPC) (1-acyl 16:0), phosphatidylcholine (PC) (1-acyl 36:4) and sphingomyelin (SM) (d18:1/16:0) at the site of the VV valve. CONCLUSION: MALDI-IMS revealed the distribution of various lipid molecules in normal veins and VVs both. Accumulation of LPC (1-acyl 16:0), PC (1-acyl 36:4) and SM (d18:1/16:0) in the VV tissues suggested that inflammation associated with abnormal lipid metabolism may contribute to the development of VV.

Quantitative lymph imaging for assessment of lymph function using indocyanine green fluorescence lymphography.

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.

Indocyanine green fluorescence angiography for intraoperative assessment of blood flow: a feasibility study.

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.

Intraoperative monitoring of penile and buttock blood flow during endovascular abdominal aortic aneurysm repair.

OBJECTIVE: The purpose of this study was to assess the pelvic circulation during endovascular abdominal aortic aneurysm repair (EVAR) with a new monitoring system measuring penile and buttock blood flow. METHODS: We measured penile brachial pressure index (PBI) during EVAR by pulse-volume-plethysmography (form PWV/ABItrade mark). We also measured bilateral gluteal tissue oxygen metabolism with near-infrared spectroscopy to provide a gluteal tissue oxygenation index (TOI). Twenty-two men who underwent aortouni-iliac stentgraft with crossover bypass for exclusion of abdominal aortic aneurysm were studied. Twelve patients underwent aorto-uni-common iliac artery stentgraft (CIA) and ten underwent aorto-uni-external iliac artery stentgraft (EIA). RESULTS: In all patients, there was an immediate reduction in PBI during the EVAR procedure. After revascularization of the ipsilateral limb of the stent graft, the recovery of PBI was significantly less in EIA group. After the completion of crossover bypass, PBI in both groups recovered to the baseline values. In both groups there was a bilateral reduction in gluteal TOI during malperfusion of the internal iliac artery. After revascularization of ipsilateral limb of the stent graft, the ipsilateral TOI recovered to the baseline level in CIA patients, but recovery was incomplete in EIA patients. In contrast, contra-lateral TOI remained low in both groups after revascularization of ipsilateral limb of the stent graft. Only after completion of crossover bypass did the contra-lateral TOI recover to baseline level in both groups. CONCLUSIONS: Both TOI at the buttocks and PBI are a sensitive reflection of pelvic haemodynamics. Penile blood flow and bilateral gluteal blood flow are supplied via different circulations and both should be monitored for full assessment of the pelvic circulation.