Development of a Non-Invasive Local Heating Load Test to Detect Severe Limb Ischemia Within 200 seconds.

PURPOSE: To establish a non-invasive test method for the rapid detection of severe ischemia (SI) in the limbs in patients with peripheral arterial disease (PAD). METHODS: Between November 2019 and May 2021, 22 patients admitted for PAD to 2 hospitals agreed to participate in the study. All patients underwent a local heating load (LHL) test. SI was defined as at least 1 ankle-brachial index value of <.4 and/or transcutaneous oximetry value of <30 mmHg. The other cases were classified as mild-to-moderate ischemia (MMI). The LHL test was performed simultaneously with 15 minutes of heating and measurement by attaching a blood flow meter measuring probe combined with a warmer to the patient's dorsal foot. Evaluation consisted of 200-s periods from the start of heating to 800 seconds. For each period, perfusion value (PV) was evaluated, and slope was calculated graphically based on linear regression as PV fluctuation per minute. Test accuracy was calculated using a receiver operating characteristic curve. RESULTS: Twenty-four limbs of 18 patients were finally evaluated; 4 patients (2 with missing data, 1 with collagen disease, and 1 with embolism) were excluded, with 13 and 11 limbs in the SI and MMI groups, respectively. The SI group showed a significantly lower slope value in the first 200 seconds and lower PV at 200 seconds and thereafter. From the slope value, it was possible to detect SI with 85% sensitivity and 73% specificity at 200 seconds. PV could be determined with higher accuracy in periods after 200 seconds, with 85% sensitivity and 82% specificity at 800 seconds. CONCLUSIONS: Our non-invasive LHL test could be used as a rapid screening test to detect SI in limbs within 200 seconds, as well as a more accurate test to detect ischemia within 800 seconds.

Safety and Ease of Sheath Insertion During Endovascular Treatment Via the Common Femoral Artery After Endarterectomy With Autologous Repair: A Retrospective Cohort Study.

Background Endovascular treatment (EVT) using the common femoral artery (CFA) for access after endarterectomy (EA) may result in sheath insertion difficulties because of subcutaneous scar tissue, as well as difficulties with hemostasis. We evaluated the safety of CFA access and the ease of sheath insertion over time after EA. Method We included 19 patients (21 limbs, 40 cases) in whom the CFA was used after EA with autologous repair as an access route in EVT for peripheral arterial disease in our institution from January 2013 to December 2020. Nine limbs underwent simple closure repair and 12 underwent autologous patch repair. Difficult sheath insertions were defined as those in which additional devices (stiff guidewire or a smaller diameter sheath for dilation) were used for scheduled sheath insertion. The inability to insert a sheath with the scheduled diameter was defined as a failed sheath insertion. We evaluated the EVT timing after EA for difficult sheath insertions, and whether the CFA was repaired with simple closure or autologous patch repair during EA surgery. Results There were 10 (25%) difficult sheath insertions, with one (2.5%) failure. The rate of difficult sheath insertions peaked from 6 months to 1 year after EA and gradually decreased (47% from 6 months to 3 years, 14% thereafter). There were more statistically significant difficult sheath insertions with simple closure repair (50%) than with autologous patch repair (12%) (P = 0.018). Hemostasis devices were used in 90% of EVT cases. The median maximum sheath diameter was 6 Fr (mean = 5.8 Fr). None of the cases required surgical procedures to achieve hemostasis after EVT. Conclusion EVT may be performed safely using the CFA after EA. The difficulty of sheath insertion may differ depending on the EVT timing after EA; it was more difficult with simple closure than with autologous patch repair, possibly related to scar formation.

A novel technique of reimplantation of a radial artery that makes a hairpin turn to reduce the excessive vascular access flow in a dialysis patient.

We report a new technique called "reimplantation of an artery with a hairpin turn (RAHT)" to reduce excessive vascular access flow. A 73-year-old woman on dialysis consulted us for vascular surgery because of an increased cardiac preload. Chest radiography and echocardiography revealed an excessive shunt flow in the brachial artery (flow rate, 2336 mL/min). Vascular echo-Doppler of the left upper limb showed that the radial artery made a hairpin turn at the arteriovenous fistula (diameter, 9 mm). Diameters of the radial artery proximal and distal to the arteriovenous fistula were 5.4 and 3.7 mm, respectively. We ligated and divided the juxta-anastomosis proximal radial artery and subsequently created an end-to-side anastomosis between the proximal radial artery and the distal radial artery. The anastomosis ostium in the distal radial artery (the recipient) was formed with a 4-mm longitudinal and gently curved incision. We performed RAHT so that the small anastomosis between both arteries and the small diameter of the distal radial artery juxta-anastomosis segment could reduce the vascular access flow. The flow rates in the brachial artery were 500 mL/min just after surgery and 560 mL/min at 2 months after surgery. Postoperative chest radiography and echocardiography confirmed a decrease in cardiac preload. We believe that this RAHT technique could be useful as one of the options to reduce the flow in patients who have excessive vascular access flow with a radial artery that makes a hairpin turn.

The Comparison between Axillofemoral Bypass and Endovascular Treatment for Patients with Challenging Aortoiliac Occlusive Disease as Alternative Treatment to Aortofemoral Bypass.

Objective: Although aortofemoral bypass (AoFB) is the standard treatment for challenging aortoiliac occlusive disease (AIOD), less-invasive treatments, such as axillofemoral bypass (AxFB) or endovascular treatment (EVT) have been conducted for patients with severe comorbidities. In this study, we compared the clinical outcomes between AxFB and EVT for AIOD. Materials and Methods: We retrospectively reviewed 9 patients with AxFB and 10 with EVT for challenging AIOD. The patients' information and operative results were evaluated. The rates of patency and limb salvage were analyzed according to the Kaplan-Meier method. Results: In the EVT group, 5 of 10 (50%) patients had aortic stenting alone, 3 (30%) received aorto-uniiliac stenting, and 2 (20%) received aorto-biiliac stenting. In the AxFB group, 2 cases (22.2%) showed acute graft thrombosis; however, in the EVT group, no acute thrombotic complications were seen. The primary patency rates in the AxFB and EVT groups at 5 years were 53.6% and 81.2%, respectively (log rank P=0.225), and the assisted primary patency rates at 5 years were 53.6% and 100%, respectively (log rank P=0.012). Conclusion: EVT exhibited a more durable, better long-term patency rate than AxFB. EVT may, therefore, be a viable treatment alternative to AoFB for challenging AIOD.

The Comparison of Long-Term Results between Aortofemoral and Axillofemoral Bypass for Patients with Aortoiliac Occlusive Disease.

PURPOSE: We evaluated the clinical outcomes of aortofemoral bypass (AoFB) and axillofemoral bypass (AxFB) surgeries for complex aortoiliac occlusive disease (AIOD) and compared them from the perspectives of safety and efficacy. METHODS: We retrospectively reviewed 21 patients with AoFB grafting and 9 patients with AxFB grafting. The demographic information of the patients was examined, and the intra-, peri-, and postoperative results as well as long-term outcomes were evaluated. RESULTS: In the AoFB, 2 of 21 (9.5%) cases had intra- and perioperative complications, and 4 of 21 (19.0%) cases had postoperative complications; however, there were no postoperative mortalities. In the AxFB, two of nine (22.2%) cases had postoperative graft thrombosis; however, again there were no postoperative mortalities. According to Kaplan-Meier analysis, the primary patency rates in the AoFB and AxFB groups at 5 years were 94.8% and 53.6%, respectively (P = 0.001), while the limb salvage rates at 5 years were 96.4% and 92.9%, respectively (P = 0.320). CONCLUSIONS: Even though the patency rates with AxFB grafting were inferior to those with AoFB grafting, AxFB was able to achieve equivalent limb salvage rates and should thus be considered as an alternative treatment method, especially when limb salvage is a goal.

A Case of Total Excision of a Thrombosed-Venous Aneurysm in the Sural Vein.

Venous aneurysm (VA) is an uncommon vascular disease; however, VA, especially in the lower extremities, can lead to critical complications, such as pulmonary embolism (PE). We report a case with a VA located in the sural vein (SV), which did not lead to PE; however, it had the potential to cause PE. Therefore, we treated this VA by total excision. The popliteal vein (PV) is the most common VA location in the lower extremities, but SV is extremely rare. We should always be aware that, in addition to the PV, VAs may also occur in the SV.

In Patients with Severe Peripheral Arterial Disease, Revascularization-Induced Improvement in Lower Extremity Ischemia Can Be Detected by Laser Speckle Contrast Imaging of the Fluctuation in Blood Perfusion after Local Heating.

BACKGROUND: We previously reported the utility of the perfusion value (PV) fluctuation slope for detecting severe ischemia in the lower limb. Our approach was based on a thermal load test mimicking the well-known physiological reaction termed "cold-induced vasodilation," which is known to occur as a 3-phase phenomenon. The slope parameter quantifies the decrease in PVs accompanying the relative cooling (third phase) following the transient increase in blood flow (second phase) induced by the applied thermal load. This phenomenon of "relative" cold-induced vasodilation (rCIVD) can be monitored using laser speckle contrast imaging (LSCI) after applying the thermal load (LTL test). Here, we aimed to determine whether the slope parameter obtained via the LTL test also reflects the improvement in hemodynamics after revascularization. METHODS: The study enrolled 16 patients (18 limbs), who underwent revascularization for peripheral arterial disease (PAD). The measurements were performed at 2 sites in each limb (in total, 34 sites; 2 sites in one patient were excluded because of significant movement during the measurement). For each site, we recorded the slope describing the behavior of PVs (decrease or plateau) in the third phase of rCIVD, following the initial, heating-induced increase in perfusion (second phase of rCIVD). The plateau group (group P), which included patients with an abnormal rCIVD, and the decrease group (group D), which included patients with a normal rCIVD, were defined based on perfusion slope values of <0.20 and ≥ 0.20 perfusion units/min, respectively. We also quantified the transient increase in perfusion (from baseline to peak) as a descriptor of perfusion behavior during the second phase of rCIVD. RESULTS: In group P, the change in median values (25-75%) of the slope, transcutaneous oxygen tension, and ankle-brachial index (ABI) from before to after operation was (-0.02 [-0.04 to 0.02]; 4 [1-11]; and 0.08 [0-0.27]) to (0.39 [0.32-0.59]; 46 [37-54]; and 0.81 [0.72-0.90]). Conversely, in group D, the change in the median values of the slope, transcutaneous oxygen tension, and ABI between before and after operation was (0.38 [0.32-0.49]; 40.5 [35-45]; and0.58 [0.57-0.65]) to (0.44 [0.30-0.64]; 52 [43-56]; and 0.92 [0.81-0.99]). Sites exhibiting perfusion pattern of group D in the third phase of rCIVD showed no significant change in slope after revascularization (P = 0.21), whereas the slope in group P increased significantly after revascularization, becoming similar to the postoperative slopes in group D (P = 0.81). The amount of transient increase in perfusion, which quantified the behavior in the second phase of rCIVD, showed a similar behavior. Preoperatively, all patients in group P had rest pain and/or ulcer of the foot, whereas only few patients in group D had such symptoms. CONCLUSIONS: Normal rCIVD response in the LTL test indicates less-than-severe ischemia, while abnormal rCIVD response measured via the LTL test indicates severe ischemic symptoms, such as critical limb ischemia. Notably, patients with an abnormal rCIVD response can develop a normal rCIVD response following revascularization, thereby reflecting an improvement in blood flow. The LTL test assessing rCIVD response can be useful for detecting severe limb ischemia, such as critical limb ischemia (CLI), and determining the departure from severe limb ischemia by revascularization.

Novel assessment tool based on laser speckle contrast imaging to diagnose severe ischemia in the lower limb for patients with peripheral arterial disease.

OBJECTIVE: We propose a new assessment tool to diagnose severe ischemia of the lower limb in peripheral arterial disease, using laser speckle contrast imaging to evaluate heating-induced microcirculatory fluctuations in the proximal and distal sites of the dorsal foot. STUDY DESIGN: A cross-sectional study. METHODS: We recorded the slope describing the behavior of perfusion values (decrease or plateau) following the initial, heating-induced increase in perfusion in 63 feet of patients with clinical signs of peripheral arterial disease. RESULTS: The plateau and decrease groups were defined as having perfusion slopes of <0.20 and ≥0.20 PU/min, respectively. Transcutaneous oxygen tension was significantly lower (P < 0.001) in the plateau than in the decrease group (8 vs. 45 mmHg), indicating more severe ischemia. The laser speckle contrast imaging thermal load test discriminated transcutaneous oxygen tension <30 mmHg with good sensitivity (78.7%) and specificity (96.2%), and an area under the curve of 0.908. CONCLUSIONS: Both transcutaneous oxygen tension and the laser speckle contrast imaging thermal load test are useful in diagnosing severe ischemia in the foot. Lasers Surg. Med. 49:645-651, 2017. © 2017. The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.