"If we can standardize the DSA acquisition and evaluation method, syngo iFlow is a powerful imaging tool for peripheral intervention procedures, not only for the assessment of the outcome, but also for intra-procedural decision making."1
Jianping Gu, M.D.
Department of Interventional Radiology, Nanjing, No.1 Hospital, China
A 75-year-old male patient with a 8-year history of hypertension suffered from lower extremity arterial occlusive disease. He was treated with the implantation of a stent three years ago. After two years, the symptoms of intermittent claudication emerged and gradually progressed. Half a month ago, the patient revisited the hospital, presenting with severe pain and numbness in his right lower limb, causing his maximum walking distance to fall below 20-30 meters.
The middle and upper segments of the right superficial femoral artery were occluded, while the lower segment still showed sufficient perfusion due to collateral flow. The popliteal, peroneal, anterior tibial, and posterior tibial arteries were not obstructed but presented with localized plaque formations. A severe stenosis existed at the bifurcation of the posterior tibial artery.
A balloon dilatation (5F, 4x120 mm, Admiral, Invatec, Italy) and a following thrombolysis therapy were performed at the upper segment of the right superficial femoral artery. The DSA examination performed after nine days showed a minor improvement of circulation, but the occlusion still existed. In the next few days, two stents (6x150 mm, Protege, EV3) were implanted into the right superficial femoral artery to reopen the vessel. However, the post-DSA showed a new occlusion at the bifurcation of the popliteal artery, presumably due to an embolus from the superficial femoral artery. A careful analysis of pre- and post-syngo iFlow measurements, which can be seen in figures 1-5, indicated that the perfusion and circulation around the distal arteries were sufficient. After a risk-benefit analysis, the physician decided that no further treatment would be needed. After the procedure, the patient was asymptomatic.
In most cases syngo iFlow was used as an offline tool to post-process the DSA images and to help the physician for diagnosis or assessment. This case demonstrated the capabilities of syngo iFlow to evaluate the perfusion and circulation in and around distal arteries during the interventional procedure. The functional information was very valuable for choosing the right treatment strategy for the next step. syngo iFlow images were able to achieve precise measurements concerning time-to-peak of contrast medium flow in distal arteries. The case demonstrates that syngo iFlow provides essential hemodynamic and perfusion information to support the decision making for the management of intra-procedural complications during a peripheral vascular intervention.
[left] syngo iFlow image before treatment of the stenosed superficial femoral artery. [right] During stenting of the superficial femoral artery an occlusion of the popliteal bifurcation was caused by an embolus (A). syngo iFlow shows the hemodynamic changes in the distal vessels. Time-to-peak (TTP) analysis based on the syngo iFlow images showed an increased flow in a collateral branch (D). At the same time blood flow within the anterior (B) and posterior tibial arteries (C) slowed down.
A: Bifurcation of popliteal artery
B: Anterior tibial artery TTP (up) 2.5 s
C: Posterior tibial artery TTP (up) 1.5 s
D: Collateral branch artery TTP (down) 2.5 s
syngo iFlow measurement shows improved distal blood flow after intervention despite the embolus. [left] syngo iFlow image before treatment [right] syngo iFlow image after treatment TTP shows that (E) the blood flow in the malleoar artery was almost the same as before (TTP (up) 0.5 s) and that (F) the blood flow in the dorsalis pedis artery was improved (TTP (down) 3.5 s).
The statements by Siemens' customers described herein are based on results that were achieved in the customer's unique setting. Since there is no "typical" hospital and many variables exist (e.g., hospital size, case mix, level of IT adoption) there can be no guarantee that other customers will achieve the same results.