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Bruno Migliara (Peschiera del Garda, Italy) views the Shockwave E8 as an essential part of his treatment algorithm for complex calcified lesions in patients with below-the-knee (BTK) chronic limb-threatening ischaemia (CLTI), here sharing a case report demonstrating his clinical experience with the device.
Clinical case
A 76-year-old male with arterial hypertension, diabetes, severe heart disease (previous coronary bypass and aortic valve stenosis) and chronic renal disease (Stage IV with eGFR=27) presented in the out-clinic department with an extensive dry gangrene of the second and third toes and distal gangrene of the fourth (Figure 1). Duplex scan showed diffuse calcification of the superficial femoral artery (SFA) and popliteal artery, but no haemodynamic stenosis. The scan also showed occlusion of the BTK arteries, with indirect flow at the dorsalis pedis (pedal acceleration time [PAT]=223msec, stage 4). Transcutaneous oxygen pressure (TcPO2) was 15mmHg and the Wound, Ischemia, and foot Infection (WIfI) class was 3-3-2.
Based on the clinical and noninvasive evaluation, we performed an angiographic study. This showed diffuse calcification, with short sub-occlusion of the distal popliteal artery (P3), total flush occlusion of the anterior tibial artery (ATA), total occlusion of the posterior tibial artery (PTA), and a patent but extensively diseased peroneal artery supplying the flow to the foot (Figures 2–4).
Treatment
Based on the location of the lesions and on the angiography, we decided to try to cross and treat the ATA in order to obtain a direct flow into the forefoot, improving oxygen and nutrition in the dorsum, where the lesion was more extensive.
Due to the heavily calcified, flush occlusion of the ATA, it was not crossable with antegrade access. Instead, we performed a retrograde puncture of the distal ATA using the Astato 20 0.014 guidewire (Asahi Intecc Medical). The occlusion was crossed in retrograde fashion, regaining the true lumen in the distal popliteal artery (Figure 5).
After that, the guidewire was externalised through the proximal sheath and a 2mm low-profile balloon was pulled through the occlusion utilising the BadForm technique (Figure 6). After pre-dilatation of the occlusion, we chose to treat with the 3mm Shockwave S4 catheter. The catheter was introduced and an attempt was made to cross the lesion and treat it in the ATA; however, the Shockwave S4 stopped in the proximal part of the ATA and would not advance across the lesion, highlighting a limitation of the Shockwave S4 catheter (Figure 7). At this time, the new 3.5mm Shockwave E8 catheter had entered the market. We decided to proceed with the Shockwave E8, as this case would provide a good test following the inability to cross with Shockwave S4. As you can see, Shockwave E8 was able to cross the length of occluded ATA from the origin to the distal third, treating a long and heavily calcified occlusion with the 400 pulses available on the new device (Figures 8–10). The final angiography showed complete recanalisation of the ATA, with significant improvement of the flow into the foot (Figure 11). At the end of the procedure, PAT was 84msec. After removal of the necrotic area, reconstruction was performed using autologous skin and complete healing was achieved in around three months (Figures 12–14).
Conclusion
In CLTI patients with heavily calcified BTK arteries, after crossing the lesion, it’s mandatory to perform an effective treatment to modify not only the superficial but also the deep calcium. The Shockwave E8’s mechanism of action enables calcium to be modified while preserving soft tissue, improving compliance of the artery wall, and attaining luminal gain with low barotrauma and minimal risk of dissection.
This case illustrated the significant benefits of the Shockwave E8 catheter versus the previous generation of tibial catheter: Shockwave S4. Indeed, the new generation of this catheter has significantly better trackability due to the improved tip configuration and hydrophilic coating, allowing it to cross complex lesions. The Shockwave E8 also enables treatment of longer lesions with an integrated balloon length of 80mm and 400 available pulses versus the Shockwave S4, with a 40mm integrated balloon length and 160 pulses, which reduced the device’s ability to treat complex BTK disease. The Shockwave E8 now provides a first-line tool to optimise the treatment of complex calcium in an extremely safe and effective way.
Case images
Bruno Migliara is chief of the Vascular and Endovascular Unit at Pederzoli Hospital in Peschiera del Garda, Italy and a paid Shockwave Medical consultant. The views expressed in this article are those of the physician and may not reflect the views of Shockwave Medical.
