Clinical validity of the Japanese below-the-knee chronic total occlusion scoring system for the prediction of successful guidewire crossing.

OBJECTIVE: To validate the Japanese below-the-knee (J-BTK) chronic total occlusion (CTO) score for the prediction of successful guidewire crossing (S-GC) in angiographic evaluation. METHODS: A prospective, multicenter, nonrandomized study examined 751 consecutive BTK CTOs in 497 patients treated with endovascular therapy in 16 Japanese medical centers from April 2021 to March 2022. The cohort was classified into 2 groups: an S-GC group and a failed guidewire crossing group. RESULTS: The J-BTK CTO score, which assigned one point to "Blunt type at the proximal entry point," one point to "Calcification at the proximal entry point," one point to "Reference vessel diameter <2.0 mm," one point to "CTO length ≥200 mm," and two points to "No outflow of the target vessel," was used to categorize BTK CTOs into 4 grades with varying probabilities of S-GC: grade A (J-BTK CTO score of 0 and 1), grade B (score of 2 and 3), grade C (score of 4 and 5), and grade D (score of 6). Rates of S-GC in each grade (grades A, B, C, and D) were 97.5%, 89.1%, 62.5%, and 27.3%, respectively. The area under the receiver-operating characteristic curve for S-GC was 0.8304. Although the previous J-BTK CTO study enrolled only de novo lesions, both de novo and restenotic lesions were evaluated in this study. De novo lesions have a lower chance of S-GC (odds ratio: 0.24, 95% confidence interval: 0.09-0.67) in the multivariate analysis, and the area under the receiver-operating characteristic curve of the modified J-BTK CTO score, which additionally assigned two points to "De novo lesion," was 0.846. The modified J-BTK CTO score showed an appropriate calibration (Hosmer-Lemeshow P = .957). CONCLUSIONS: The J-BTK CTO score and the modified J-BTK CTO score predict the probability of an S-GC of BTK CTOs and stratify the difficulty of endovascular therapy for BTK CTOs in angiographic evaluation.

Evaluation of the efficacy of combined device strategies for long femoropopliteal artery disease.

One of the major problems associated with bare nitinol stent implantation is stent fracture, particularly in the popliteal artery. The purpose of this study was to determine whether drug coated balloons (DCB), interwoven stents (IWS), or plain old balloon angioplasty (POBA) would be suitable for use in distal femoropopliteal (FP) long lesions when an Eluvia stent was implanted proximal to a lesion. This was a multi-center retrospective study enrolling patients undergoing concomitant use of Eluvia with DCB, IWS or POBA for symptomatic atherosclerotic femoropopliteal disease (lesion length > 15 cm) [Rutherford category 2-6] between January 2018 and September 2021. 79 patients with 89 femoropopliteal lesions were enrolled in this study. The mean lesion length and the percentage of the popliteal artery involvement was 24.3 ± 6.4 cm vs 24.0 ± 9.0 cm vs 26.6 ± 6.2 cm and 65.8% vs 89.4% vs 67.8% for the Eluvia + DCB, Eluvia + IWS, and Eluvia + POBA groups, respectively. The 1-year Kaplan-Meier estimates of primary patency and freedom from major adverse limb events (MALEs) were 53.3% vs 44.1% vs 24.2% and 62.4% vs 51.0% vs 28.1%, respectively. Eluvia + POBA was associated with a lower rate for 1-year primary patency (HR 2.49; 95% confidence interval (CI): 1.28-4.87; p = 0.007 and HR 2.38; 95% CI: 1.13-5.77; p = 0.04). In SFA long lesions with proximal Eluvia implantation, distal implantations of either a DCB or IWS were comparable, as opposed to POBA alone which generated worse results.

One-Year Clinical Outcomes and Prognostic Factors Following Revascularization in Patients With Acute Limb Ischemia　- Results From the RESCUE ALI Study.

BACKGROUND: Acute limb ischemia (ALI) is a limb- and life-threatening condition and urgent treatment including revascularization should be offered to patients unless the limb is irreversibly ischemic. The aim of this study was to investigate 1-year clinical outcomes and prognostic factors following revascularization in patients with ALI.Methods and Results: A retrospective, multicenter, nonrandomized study examined 185 consecutive patients with ALI treated by surgical revascularization (SR), endovascular revascularization (ER), or hybrid revascularization (HR) in 6 Japanese medical centers from January 2015 to August 2021. The 1-year amputation-free survival (AFS) rate was estimated to be 69.2% (95% confidence interval [CI], 62.8-76.2%). There were no significant differences among SR, ER, and HR regarding both technical success and perioperative complications. Multivariate analysis revealed that Rutherford category IIb and III ischemia (hazard ratio [HR]: 1.86; 95% CI: 1.06-3.25), supra- to infrapopliteal lesion (HR: 2.06; 95% CI: 1.08-3.95), and technical failure (HR: 2.58; 95% CI: 1.49-4.46) were independent risk factors for 1-year AFS. CONCLUSIONS: Rutherford category IIb and III ischemia, supra- to infrapopliteal lesions, and technical failures were identified as independent risk factors for 1-year AFS. Furthermore, patients with multiple risk factors had a lower AFS rate.

A novel endovascular method of atherectomy for calcified common femoral and popliteal disease using the crosser system: Crossbow and Rambow techniques.

OBJECTIVES: This study aims to report the efficacy and safety of new atherectomy methods using the Crosser system for calcified lesions in the common femoral and popliteal artery: the Crosser system supported by bended 0.014 wire (Crossbow) technique and retrograde approach of sheathless Crosser system supported by bended 0.014 wire (Rambow) technique. MATERIALS AND METHODS: This report describes a single-center, retrospective study. A total of 23 patients (mean ± SD age, 73 ± 10 years; 19 men) with symptomatic peripheral artery disease received the Crossbow technique and Rambow technique for treatment of calcified common femoral and popliteal disease; these patients were enrolled between October 2013 and October 2015. The primary efficacy outcome was acute technical success, defined as achievement of residual stenosis < 30% for stenting and < 50% for angioplasty or atherectomy. The primary safety outcome was assessed on the basis of angiographic complications. RESULTS: The Crossbow and Rambow techniques were undertaken in 100% and 17% of the patients, respectively. Acute technical success was achieved in 96% of the patients. There were two embolic events. CONCLUSION: Crossbow and Rambow techniques could be effective atherectomy methods of calcified common femoral and popliteal disease. Regarding safety, embolic protection devices may be needed for our atherectomy methods.

Prediction of Technical Failure of Inframalleolar Angioplasty in Patients with Chronic Limb Threatening Ischaemia.

OBJECTIVE: This study sought to: determine anatomically evaluated predictors of the technical failure of inframalleolar angioplasty (IMA), develop a predictive model for unsuccessful IMA, and investigate the effect of IMA on clinical outcomes in patients with chronic limb threatening ischaemia (CLTI). METHODS: This single centre retrospective observational study enrolled 159 patients with CLTI who underwent IMA for de novo occluded lesions between November 2017 and May 2021. These patients were divided into two groups: the Failed IMA group (n = 62) and the Successful IMA group (n = 97). RESULTS: In multivariable analysis, no target vessel outflow (OR 39.8, 95% CI 10.7 - 148, p < .001), medial artery calcification (MAC) grade (OR 4.91, 95% CI 1.40 - 17.3, p = .010), and occluded pedal arch (OR 5.2, 95% CI 1.2 - 22.7, p = .030) were identified as independent predictors of IMA technical failure. The risk prediction model had an area under the receiver operating characteristic curve (AUC) of 0.93; after bootstrapping adjustment for optimism, this value represented a corrected AUC of 0.95. The patients in the Successful IMA group had a significantly higher proportion of wound healing at 12 months than those in the Failed IMA group (log rank p = .030). IMA technical failure was associated with a significant change in the proportion of wound healing (HR 0.59, 95% CI 0.37- 0.94, p = .030). CONCLUSION: No target vessel outflow, MAC grade, and occluded pedal arch were independent predictors of IMA technical failure. Additionally, successful IMA was associated with better wound healing outcomes at 12 months. Furthermore, a model incorporating these three predictors precisely predicted IMA technical failure.

Three-Year Clinical Outcomes Following Implantation of LifeStent Self-Expanding Nitinol Stents in Patients With Femoropopliteal Artery Lesions.

The aim of this study was to evaluate midterm clinical outcomes after implantation of LifeStent self-expanding nitinol stents for the treatment of femoropopliteal lesions. This retrospective, multicenter, non-randomized study examined 260 femoropopliteal lesions in 250 consecutive patients with peripheral artery disease implanted with LifeStents from April 2016 to April 2017. The prevalence of chronic total occlusion (CTO), lesion length ≥25 cm, and distal reference vessel diameter (RVD) <5 mm was 58%, 35%, and 50%, respectively. The 3-year restenosis rate in the overall population was estimated to be 72.9% and a major adverse limb event was observed in 36.9%. Multivariate analysis revealed that chronic limb-threatening ischemia (CLTI) (odds ratio [OR]: 8.04; 95% confidence interval [CI]: 1.86-34.7), CTO (OR: 4.87; 95% CI: 1.43-16.6), lesion length ≥25 cm (OR: 5.95; 95% CI: 1.11-32.0), and distal RVD <5 mm (OR: 4.43; 95% CI: 1.34-14.6) were independent risk factors for 3-year restenosis. The present study demonstrated the midterm clinical outcomes and risk factors for restenosis after implantation of the LifeStent in femoropopliteal artery lesions. CLTI, CTO, lesion length ≥25 cm, and distal RVD <5 mm predicted decreased patency after a 3-year follow-up.

Mortality risk after use of a paclitaxel-coated stent in femoropopliteal peripheral artery disease.

Although paclitaxel-based devices which demonstrated improved outcomes in the treatment of lower-extremity peripheral artery disease (PAD) have been used worldwide, Katsanos et al. reported a systematic review and summary-level meta-analysis of RCTs in which application of paclitaxel-based devices in the femoropopliteal artery was associated with an increased mortality risk. The purpose of this study was to describe the safety of endovascular therapy (EVT) using paclitaxel-coated stents for femoropopliteal disease by evaluating the mortality risk compared with patients treated with paclitaxel-free devices. A retrospective, multicenter, non-randomized study examined 481 de-novo symptomatic PAD patients treated in 13 Japanese medical centers from January 2011 to December 2015. The risk of all-cause mortality was analyzed between the 65 patients treated with a paclitaxel-coated stent (PTX-coated group) and 416 patients treated with an uncoated balloon or bare nitinol stent (PTX-free group). Overall survival of the PTX-coated group and the PTX-free group were compared after propensity score matching. The 2-year overall survival estimates were 87.7% in the PTX-coated group vs 88.7% in the PTX-free group. There were no significant differences in the mortality risk between the groups through a full follow-up of 2 years (p = 0.80). The multivariate cox proportional hazards model identified three significant predictors of mortality; age (HR, 1.08; 95% CI, 1.03-1.13; p = 0.002), hemodialysis (HR, 3.16; 95% CI, 1.34-7.42; p = 0.008), and albumin (g/dl) (HR, 0.46; 95% CI, 0.25-0.85; p = 0.01).

Parallel Wiring Using a Single Intravascular Ultrasound Catheter with Double Rapid Exchange Lumens Technique for Chronic Total Occlusions in Peripheral Artery Disease.

PURPOSE: To describe a parallel wiring using a single intravascular ultrasound catheter with double rapid exchange lumens (PASSABLE) technique for peripheral CTOs. TECHNIQUE: The technique is demonstrated in a 73-year-old patient with CTOs of the superficial femoral and popliteal artery. Intravascular ultrasound (IVUS) examination revealed the first guidewire was advanced to the intramedial space of the popliteal artery. Following insertion of the first guidewire into only the distal rapid exchange lumen of the IVUS catheter and a second guidewire into the proximal rapid exchange lumen, a guidewire torquer was passed over it and tightened close to an exit port of the proximal rapid exchange lumen to prevent it from exiting an entry port while advancing the IVUS catheter. The IVUS catheter was advanced to the intraplaque region using only the distal rapid exchange lumen and the second guidewire was then advanced to the intraplaque region under IVUS guidance. The IVUS-guided wiring using the second guidewire on both the distal and proximal rapid exchange lumen was continued and resulted in a successful guidewire crossing into the distal true lumen. CONCLUSION: This novel technique may prove beneficial in enabling operators to perform IVUS-guided parallel wiring more easily and efficiently.

Combined Treatment With Hyperbaric Oxygen Therapy and Endovascular Therapy for Patients With Chronic Limb-Threatening Ischemia　- Study Protocol for the HOTFOOT Multicenter Randomized Controlled Trial.

Background: Hyperbaric oxygen therapy (HBOT) is regarded as one of the therapeutic options added to standard care to improve lower-limb outcomes in patients with chronic limb-threatening ischemia (CLTI). However, the current guidelines specify that HBOT should not be offered instead of revascularization to prevent limb loss in CLTI patients. The aim of the HOTFOOT study is to examine the impact of HBOT on wound healing in CLTI patients after successful endovascular therapy (EVT). Methods and Results: The HOTFOOT study is a multicenter prospective randomized open blinded-endpoint trial that is to be conducted at 10 trial centers in Japan between February 2021 and February 2022. This study will enroll 140 patients with CLTI receiving successful EVT. Eligible participants will be allocated 1 : 1 to either the EVT+HBOT or EVT group; participants in the EVT+HBOT group will receive 30 HBOT sessions. The primary outcome is the time to complete wound healing over the 6-month follow-up. Secondary outcomes during the 6-month follow-up are the proportion of patients who achieved complete wound healing, freedom from major lower-limb amputation, amputation-free survival, and freedom from target lesion reintervention. Conclusions: This study is expects to assess whether HBOT, in combination with successful EVT, can improve lower-limb outcomes in CLTI patients.

Prediction of successful guidewire crossing of below-the-knee chronic total occlusions using a Japanese scoring system.

OBJECTIVE: To develop a scoring system that can adequately predict a successful guidewire crossing (S-GC) of below-the-knee (BTK) chronic total occlusions (CTOs) in angiographic evaluation. METHODS: A retrospective, multicenter, nonrandomized study examined 448 consecutive BTK CTOs in 299 patients treated with endovascular therapy in seven Japanese medical centers from April 2012 to April 2020. The cohort was classified into two groups: an S-GC group and a failed guidewire crossing group. RESULTS: The final logistic regression model created by a backward stepwise multivariate logistic regression model included five variables: "No outflow of the target vessel," "CTO length ≥200 mm," "Reference vessel diameter <2.0 mm," "Calcification at the proximal entry point," and "Blunt type at entry point." Optimisms were adjusted using 1000 bootstrap samples with replacement and candidate's risk score models developed according to optimism-adjusted correlation coefficients of risk factors. Choosing the best model as the Japanese-BTK (J-BTK) CTO score by comparing the optimism-adjusted area under receiver-operating characteristic curves it was decided to assign one point to "Blunt type at the proximal entry point," one point to "Calcification at the proximal entry point," one point to "Reference vessel diameter <2.0 mm," one point to "CTO length ≥200 mm," and two points to "No outflow of the target vessel." This rule was then used to categorize BTK CTOs into four grades with varying probabilities of S-GC: grade A (J-BTK CTO score of 0 and 1), grade B (score of 2 and 3), grade C (score of 4 and 5), and grade D (score of 6). Rates of S-GC in each grade (grades A, B, C, and D) were 97.3%, 76.8%, 19.3%, and 0%, respectively. Lesions categorized as grade C or D have a lower chance of S-GC. Internal validation was performed using the Hosmer-Lemeshow test (P = .99). CONCLUSIONS: The J-BTK CTO score predicts the probability of an S-GC of BTK CTOs and stratifies the difficulty of endovascular therapy for BTK CTOs in angiographic evaluation.

Effect of Target Lesion Revascularization on Restenosis Lesions of the Superficial Femoral Artery without Recurred Symptoms after Endovascular Therapy.

AIM: This study aims to elucidate the effects of early application of target lesion revascularization (TLR) to restenosis lesions of the superficial femoral artery (SFA) without recurrence of symptoms. Despite recent improvements in endovascular therapy (EVT) for the SFA, restenosis remains to be a problem. However, restenosis is not always associated with the recurrence of limb symptoms. Although early application of TLR is not generally approved for restenosis lesions of the SFA without recurred symptoms, it is expected to contribute to long-term patency and other favorable outcomes. Nonetheless, its effectiveness remains to be determined. METHODS: We retrospectively analyzed 616 patients who developed restenosis after undergoing femoro-popliteal EVT for claudication (Rutherford category 1 to 3) due to de novo femoro-popliteal lesions between January 2010 and December 2016 at 11 centers in Japan. Recurred symptoms were defined as symptoms of the same or higher Rutherford categories than those immediately before the initial EVT. RESULTS: Of the patients, 291 (47 %) lacked recurred symptoms; 69 (24 %) underwent TLR for restenosis. After propensity matching, the risk of occlusion was determined to be not significantly different between the TLR and observation groups; the 3-year occlusion-free rate was 68 % and 62 %, respectively (P=0.84). The risk of recurring symptoms, critical limb ischemia, and all-cause death was also found to be comparable between groups. The incidence of target vessel revascularization was significantly higher in the TLR than in the observation group (1.55 [95 % confidence interval: 1.25-1.93] vs. 0.59 [0.41-0.85] per 3 person-years). CONCLUSIONS: In patients with SFA restenosis without recurred symptoms, early application of TLR showed no advantages.

Insufficient recovery of fractional flow reserve even after optimal implantation of drug-eluting stents: 3-year outcomes from the FUJI study.

BACKGROUND: Adequate improvement in fractional flow reserve (FFR) is not necessarily achieved in some cases of drug-eluting stent (DES) implantation, even when imaging confirms successful placement. We hypothesized that post-stent FFR may be associated with advanced diffuse atherosclerotic condition. We explored the relationships between FFR values after DES implantation (post-stent FFR). METHODS: A total of 218 patients were included in this prospective, multicenter study and were divided into two groups: adequate FFR group (post-stent FFR >0.80, n=176) and inadequate FFR group (post-stent FFR ≤0.80, n=42). The primary endpoint was a major adverse cardiovascular event (MACE) including cardiac death, non-fatal myocardial infarction (MI), unplanned coronary revascularization, and hospitalization for heart failure. The secondary endpoints were event rate of all-cause death, non-fatal MI, unplanned coronary revascularization, non-fatal stroke, and hospitalization for heart failure. RESULTS: During follow-up of 31.4±8.7 months, 34 patients (16%) had cardiovascular events. Inadequate FFR group was significantly associated with higher risk of MACE (hazard ratio: 3.86; 95% confidence interval: 1.17-12.76, p=0.026; log-rank p=0.027). In particular, the incidence of unplanned coronary revascularization on non-target lesions was significantly higher in the inadequate FFR group (log-rank p=0.031). CONCLUSIONS: Post-stent FFR ≤0.80 was associated with a high incidence of non-target lesion revascularization and could be a surrogate marker for advanced atherosclerotic condition in the vessels of the entire coronary artery.

Thrombectomy Using Myocardial Biopsy Forceps in Acute Limb Ischemia Patients.

PURPOSE: To evaluate the efficacy and safety of thrombectomy using myocardial biopsy forceps for the treatment of acute limb ischemia (ALI). MATERIALS AND METHODS: A retrospective review of 11 ALI patients (12 affected limbs, 18 affected vessels) who underwent thrombectomy using biopsy forceps between November 2011 and April 2016 was performed. Of the 12 affected limbs, 2 limbs had stent thrombosis, 1 limb had thrombotic occlusion at a de novo stenosis site, and 9 limbs had embolic ALI. Biopsy forceps were used for angiographically limited arterial flow that persisted after the use of an aspiration catheter and conventional balloon angioplasty. The general technique for use of the biopsy forceps included advancement in parallel to a guidewire to the thrombus site, grasping of the thrombus with the forceps, and confirmation of grasping the thrombus with injection of a contrast medium prior to thrombus extraction. RESULTS: Partial or total retrieval of the thrombus was angiographically confirmed in 12 of the 18 affected vessels, with restoration of normal blood flow in 11 vessels. Unsuccessful results in the remaining 6 affected vessels appeared to be due to friction at the aortoiliac bifurcation caused by the contralateral approach, small vessel size, or curvature of the anterior tibial artery. None of the 18 treated vessels had any complications such as dissection or perforation of the target vessel wall and distal emboli. None of the surviving patients required major or minor amputation. CONCLUSIONS: Thrombectomy using biopsy forceps is a feasible technique for removal of an arterial thrombus in patients with ALI.

Comparison of Angiographic Dissection Patterns Caused by Long vs Short Balloons During Balloon Angioplasty of Chronic Femoropopliteal Occlusions.

PURPOSE: To describe the feasibility of balloon angioplasty using a long balloon for chronic femoropopliteal occlusions by evaluating angiographic dissection patterns for optimization of outcomes in balloon angioplasty. METHODS: A retrospective, single-center analysis examined 101 symptomatic patients (mean age 75.6±9.9 years; 65 men) with single de novo femoropopliteal occlusive lesions treated with balloon angioplasty between August 2012 and October 2016. The patients were classified into 2 groups for comparison of angiographic dissection patterns: 51 patients were treated with balloon angioplasty using long balloons (L-BA; defined as ≥220 mm in length) and 50 patients were treated with short balloon angioplasty (S-BA; defined as <150-mm-long balloons). RESULTS: Severe vessel dissection patterns, defined as type C or higher, were fewer in the L-BA group (47.1% vs 70.0% in the S-BA group, p=0.019) and the total dissection length was shorter (92.7±72.6 vs 160.4±84.6 mm in the S-BA group, p<0.001). Although the results showed no significant differences between the two groups regarding the length of chronic total occlusions (L-BA: 228.6±73.2 vs S-BA: 226.0±53.8 mm, p=0.83), inflation pressure (L-BA; 8.2±2.6 vs S-BA: 8.1±2.9 atm, p=0.86), and the other lesion characteristics, inflation time was significantly longer in the L-BA group (161.2±68.7 seconds vs 51.1±54.0 seconds in the S-BA group, p<0.001). Multivariate analysis identified a balloon length ≥220 mm as an independent negative predictor of severe vessel dissection (odds ratio 0.29, 95% confidence interval 0.11 to 0.83, p=0.02). CONCLUSION: Using long balloons for balloon angioplasty may help prevent severe vessel dissection in chronic femoropopliteal occlusions.

Evaluation for the efficacy and safety of the crosser catheter as a CTO crossing device and a flossing device.

The Crosser catheter is a unique device that facilitates antegrade intraluminal recanalization by high-frequency vibration energy and cavitation. We used this device not only as a chronic total occlusion (CTO) crossing device, but also as a flossing device in stenotic lesions and we also evaluated the efficacy of this device when used with both the "Crosser preceding" and the "Guidewire preceding" in CTOs. Complications related to this device were investigated, too. We retrospectively analyzed a total of 90 consecutive patients with peripheral artery disease in the femoropopliteal artery and below-the-knee artery (BTA). Primary technical success was defined as the successful delivery of this device into the distal true lumen. Secondary technical success was defined as successful revascularization. The safety endpoints were events of angiographic complications, including the occurrence of detachment of the metal tip from the shaft, slow flow, dissections, and perforations. Overall primary technical success rate was 93.3% and the secondary technical success rate was 96.7%. Detachment and slow flow occurred 14.4 and 4.4%, respectively, with no occurrences of either dissection or perforation. A predictor of detachment was Proposed Peripheral Arterial Calcium Scoring System (PACSS) grade 4 (OR 14.6; CI 1.26-168.5; P = 0.032). The Crosser catheter is useful not only as a CTO crossing device used with both the "Crosser preceding" and the "Guidewire preceding", but also as a flossing device in stenotic lesions. But we have to pay attention to complications related to the Crosser.