Endovascular Treatment as an Alternative to Bypass Surgery for Juxtarenal Aortic Occlusion: Results from the CHAOS (CHronic Abdominal Aortic Occlusion, ASian Multicenter) Registry.

BACKGROUND: Juxtarenal aortic occlusion (JRAO), in which the occlusion of the aorta extends to just below the renal artery, is often treated by bypass surgery because of concerns about the risk of procedural failure and fatal embolization to abdominal organs when treated with endovascular treatment (EVT). This study assessed the outcome of EVT for JRAO compared with aorto-biiliac /aorto-bifemoral (AOB) or axillo-bifemoral (AXB) bypass. METHODS: A retrospective review of an international database created by 30 centers in Asia (CHronic Abdominal Aortic Occlusion, ASian Multicenter registry) was performed for patients who underwent revascularization for chronic total occlusion of the infrarenal aorta from 2007 to 2017. Of the 436 patients, 130 with JRAO (Forty-seven AOBs, 32 AXBs, and 51 EVTs) from 25 institutions were included in this study. RESULTS: Patients were significantly older in the AXB and EVT groups and more malnourished in the EVT group than the AOB group. EVT was attempted but failed in 1 patient. Seven patients (1 [2.1%] in the AOB group, 1 [3.1%] in the AXB group, and 5 [9.8%] in the EVT group) died during hospitalization, but most of the causes in the EVT group were not related to the revascularization procedure. No visceral embolism was observed, which had been concerned, even though protection was performed only in 2 cases of the EVT group. At the latest follow-up (median duration 3.0 years), the ankle-brachial pressure index was significantly higher in the order of AOB, EVT, and AXB. At 4 years, the estimated primary and secondary patency rates of the AOB group (87.5% and 90.3%, respectively) were significantly higher than the AXB group (66.7% and 68.6%, respectively). CONCLUSIONS: AOB remains the gold standard and should be the first choice for acceptable risk patients. For frail patients, EVT is a good option and likely preferable as a first-line treatment compared to AXB.

Comparison of Aortobifemoral Bypass and Endovascular Treatment for Chronic Infrarenal Abdominal Aortic Occlusion From the CHAOS (CHronic Abdominal Aortic Occlusion, ASian Multicenter) Registry.

PURPOSE: To directly compare the clinical outcomes of aortobifemoral bypass surgery (ABF) and endovascular treatment (EVT) for chronic total occlusion (CTO) of the infrarenal abdominal aorta (IAA). MATERIALS AND METHODS: In this retrospective, multicenter study, we used an international database of 436 patients who underwent revascularization for CTO of the IAA between 2007 and 2017 at 30 Asian cardiovascular centers. After excluding 52 patients who underwent axillobifemoral bypass surgery, 384 patients (139 ABFs and 245 EVTs) were included in the analysis. Propensity score-matched analysis was performed to compare clinical results in the periprocedural period and the long-term. RESULTS: Propensity score matching extracted 88 pairs. Procedure time (ABF; 288 [240-345] minutes vs EVT; 159 [100-205] minutes, p<0.001) and length of hospital stay (17 [12-23] days vs 5 [4-13] days, p<0.001) were significantly shorter in the EVT group than in the ABF group, while the proportions of procedural success (98.9% versus 96.6%, p=0.620), complications (9.1% versus 12.3%, p=0.550), and mortality (2.3% versus 3.8%, p=1.000) were not different between the groups. At 1 months, ABI significantly increased more in the ABF group for both in a limb with the lower (0.56 versus 0.50, p=0.018) and the higher (0.49 versus 0.34, p=0.001) baseline ABI, while the change of the Rutherford category was not significantly different between the groups (p=0.590). At 5 years, compared with the EVT group, the ABF group had significantly better primary patency (89.4±4.3% versus 74.8±4.3%, p=0.035) and survival rates (86.9±4.5% versus 66.2±7.5%, p=0.007). However, there was no significant difference between the groups for secondary patency (100.0%±0.0% versus 93.5%±3.9%, p=0.160) and freedom from target lesion revascularization (TLR) (89.3±4.3% vs 77.3±7.3%, p=0.096). CONCLUSION: Even with recent advancements in EVT, primary patency was still significantly better for ABF in CTO of the IAA. However, there was no difference between the groups in terms of secondary patency and freedom from TLR at 5 years. Furthermore, there was no difference in procedural success, complications, mortality, and improvement in the Rutherford classification during the periprocedural period, with significantly shorter procedure time and hospital stay in the EVT group.

Characteristics, Antithrombotic Patterns, and Prognostic Outcomes in Claudication and Critical Limb-Threatening Ischemia Undergoing Endovascular Therapy.

PURPOSE: The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study aimed to clarify differences in clinical features and prognostic outcomes between IC and CLTI, and prognostic factors in patients undergoing endovascular therapy (EVT). MATERIALS AND METHODS: A total of 692 patients with 808 limbs were enrolled from 20 institutions in Japan. The primary measurements were the 3-year rates of major adverse cardiovascular event (MACE) and reintervention. RESULTS: Among patients, 79.0% had IC and 21.0% had CLTI. Patients with CLTI were more frequently women and more likely to have impaired functional status, undernutrition, comorbidities, hypercoagulation, hyperinflammation, distal artery disease, short single antiplatelet and long anticoagulation therapies, and late cilostazol than patients with IC. Aortoiliac and femoropopliteal diseases were dominant in patients with IC and infrapopliteal disease was dominant in patients with CLTI. Patients with CLTI underwent less frequently aortoiliac intervention and more frequently infrapopliteal intervention than patients with IC. Longitudinal change of ankle-brachial index (ABI) exhibited different patterns between IC and CLTI (pinteraction=0.002), but ABI improved after EVT both in IC and in CLTI (p<0.001), which was sustained over time. Dorsal and plantar skin perfusion pressure in CLTI showed a similar improvement pattern (pinteraction=0.181). Distribution of Rutherford category improved both in IC and in CLTI (each p<0.001). Three-year MACE rates were 20.4% and 42.3% and 3-year reintervention rates were 22.1% and 46.8% for patients with IC and CLTI, respectively (log-rank p<0.001). Elevated D-dimer (p=0.001), age (p=0.043), impaired functional status (p=0.018), and end-stage renal disease (p=0.019) were independently associated with MACE. After considering competing risks of death and major amputation for reintervention, elevated erythrocyte sedimentation rate (p=0.003) and infrainguinal intervention (p=0.002) were independently associated with reintervention. Patients with CLTI merely showed borderline significance for MACE (adjusted hazard ratio 1.700, 95% confidence interval 0.950-3.042, p=0.074) and reintervention (adjusted hazard ratio 1.976, 95% confidence interval 0.999-3.909, p=0.05). CONCLUSIONS: The CLTI is characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared with IC. Also, CLTI has approximately twice MACE and reintervention rates than IC, and the underlying inflammatory coagulation disorder per se is associated with these outcomes. CLINICAL IMPACT: The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study, JPASSION study found that CLTI was characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared to IC. Also, CLTI had approximately twice major adverse cardiovascular event (MACE) and reintervention rates than IC. Intriguingly, the underlying inflammatory coagulation disorder per se was independently associated with MACE and reintervention. Further studies to clarify the role of anticoagulation and anti-inflammatory therapies will contribute to the development of post-interventional therapeutics in the context of peripheral artery disease.

Endovascular Therapy Outcomes and Intravascular Ultrasound Findings in Thromboangiitis Obliterans (Buerger's Disease).

PURPOSE: To investigate outcomes of contemporary endovascular therapy and intravascular ultrasound (IVUS) findings in thromboangiitis obliterans (TAO) patients. METHODS: Between April 2007 and January 2016, 20 patients (mean age 45±8 years; 16 men) underwent endovascular therapy for TAO-related lesions in 25 consecutive limbs. Subjects exhibited a broad array of clinical symptoms, including critical limb ischemia (n=15) and claudication (10) in the lower (n=20) and upper (n=5) limbs. RESULTS: Procedure success was achieved in 24 (96%) limbs (complete success in 16 and partial success in 8), all of which exhibited improvements of at least 1 grade of the Rutherford category. Kaplan-Meier analysis showed that reintervention-free rates were 81.9% (95% CI 0.586 to 0.928) at 6 months and 71.7% at 10 months (95% CI 0.473 to 0.862). IVUS was performed in 20 limbs and revealed unique findings, including the "bull's-eye" appearance, "lotus-root" appearance, and "bunch of grapes" appearance. During a mean follow-up of 26±19 months, the limb salvage rate was 100% with no deaths. CONCLUSION: Contemporary endovascular therapy might be able to serve as a potential option for TAO patients with lower and upper limb symptoms. Liberal application of IVUS could help us understand the pathology of TAO to support endovascular therapy for TAO.

Potential of Using Occult Collateral Vessels for Transcollateral Intervention in Infrapopliteal Chronic Occlusion.

The transcollateral approach is a contemporary crossing technique for treating infrapopliteal chronic occlusion. However, in the setting of critical limb ischemia with multilevel disease, angiographically occult collateral vessels may be missed as a treatment opportunity. Herein, we report the potential of using occult collateral vessels for transcollateral intervention in infrapopliteal chronic occlusion.

Axillo-femoral bypass steal due to subclavian artery stenosis.

Subclavian artery stenosis can cause a flow reversal-so-called steal-not only in the ipsilateral vertebral artery, but also in the internal mammary artery in patients with a history of coronary-artery bypass grafting. Subclavian artery stenosis is also associated with peripheral artery disease elsewhere. We report a novel finding of axillo-femoral bypass steal due to subclavian artery stenosis identified by vascular ultrasonography.

Contemporary crossing techniques for infrapopliteal chronic total occlusions.

The synergism of technical refinement and advanced technology has significantly increased the popularity of infrapopliteal intervention. Since chronic total occlusion (CTO) is a common disorder among patients with symptomatic infrapopliteal artery disease, infrapopliteal CTO intervention is now evolving rapidly in the field of endovascular intervention. Guidewire crossing through the CTO is essential for a successful procedure. We review up-to-date infrapopliteal CTO crossing techniques based on the current literature.

Impact of aortorenal morphology on renal artery stent procedures: significance of aortic tortuosity and renal artery derivation.

PURPOSE: To clarify the impact of aortorenal morphology on renal artery stenting procedures. METHODS: A retrospective study evaluated 142 consecutive renal artery stenting procedures performed for de novo atherosclerotic renal artery stenosis in 119 patients (62 men; mean age 72±9 years, range 41-93). All procedures were done via a transfemoral approach without distal protection. Aortorenal morphology was classified into 3 types based on the relationship between abdominal aortic tortuosity and renal artery derivation. Using a straight reference line centered on the most angulated point of the inner curve of the infrarenal abdominal aorta, type 1 referred to a renal artery ostium that was more than half of the aortic diameter distance from the reference line in the greater curvature and less than half in the lesser curvature. Type 2 referred to a renal artery ostium that was less than half of the aortic diameter distant from the reference line in the greater curvature and more than half in the lesser curvature. Type 3 referred to a renal artery ostium that was beyond the reference line in the greater curvature or more than one aortic diameter from the reference line in the lesser curvature. The technical success rate, procedure time, final engagement technique, shape of the guide catheter used, and any adverse events were analyzed. RESULTS: Type 1 aortorenal morphology was observed in 91 cases, type 2 in 30, and type 3 in 21. All cases were successfully treated; there were no technical complications, in-hospital cardiovascular events, or deaths. Procedure time differed significantly (p<0.001) among the 3 types (type 1: 19.6±5.6 minutes, type 2: 23.3±6.8 minutes, and type 3: 32.3±9.6 minutes; p<0.05 for type 1 vs. 2, p<0.001 for type 2 vs. 3, and p<0.001 for type 1 vs. 3). There were also significant differences among types in terms of engagement technique and guide catheter shape. CONCLUSION: Aortorenal morphology was significantly associated with procedure time and the selection of engagement technique and guide catheter shape.

Contemporary infrapopliteal intervention for limb salvage and wound healing: harmonization of revascularization and wound management.

Infrapopliteal arterial disease is a significant cause of critical limb ischemia (CLI), whether single-segment or multisegment disease. The collaboration between the tremendous advancements in endovascular technology and the refinement of endovascular techniques has renewed the classic infrapopliteal interventions during the past decade. With this paradigm shift in the treatment of CLI, the role of a comprehensive approach of different disciplines for tissue loss is becoming greater. Given the increasing global burden of CLI, we review the cutting-edge diagnostic and endovascular approaches to infrapopliteal artery disease, and the importance of wound management in optimizing clinical outcomes.

Contemporary Infrapopliteal Intervention for Limb Salvage and Wound Healing.

Infrapopliteal arterial disease is a significant cause of critical limb ischemia (CLI), whether single-segment or multisegment disease. The collaboration between the tremendous advancements in endovascular technology and the refinement of endovascular techniques has renewed the classic infrapopliteal interventions during the past decade. With this paradigm shift in the treatment of CLI, the role of a comprehensive approach of different disciplines for tissue loss is becoming greater. Given the increasing global burden of CLI, we review the cutting-edge diagnostic and endovascular approaches to infrapopliteal artery disease, and the importance of wound management in optimizing clinical outcomes.

Variability in quantitative and qualitative analysis of intravascular ultrasound and frequency domain optical coherence tomography.

BACKGROUND: Frequency-domain optical coherence tomography (FD-OCT) is an intravascular imaging technique now available in the United States. However, the importance of level of training required for analysis using intravascular ultrasound (IVUS) and FD-OCT is unclear. The aim of this study was to evaluate inter- and intra-observer variability between expert and beginner analysts interpreting IVUS and FD-OCT images. METHODS AND RESULTS: Two independent expert analysts and two independent beginner analysts evaluated a total of 226 ± 2 stent cross-sections with IVUS and 232 ± 2 stent cross-sections with FD-OCT in 14 patients after stenting. Inter- and intra-observer variability for determining stent volume index (VI), as well as identifying incomplete stent apposition and dissection were assessed. The inter- and intra-observer variability of stent VI was minimal for both beginner and expert analysts regardless of imaging technology (random variability: 0.38 vs. 0.05 mm(3) /mm for IVUS, 0.26 vs. 0.08 mm(3) /mm for FD-OCT). Although qualitative IVUS analysis at the patient level revealed no significant difference between beginners and experts, this was not the case for FD-OCT. The number of overall qualitative findings noted by beginner and expert analysts were more variable (overestimated or underestimated) with FD-OCT. CONCLUSION: Despite varying levels of training, the increased resolution of FD-OCT compared to IVUS provides better detection and less variability in quantitative image analysis. On the contrary, this increased resolution not only increases the rate but also the variability of detection of qualitative image analysis, especially for beginner analysts.

Duplex criteria for in-stent restenosis in the superficial femoral artery.

OBJECTIVES: To elucidate the optimal cutoff and accuracy of duplex ultrasonography (DUS) parameters for in-stent restenosis (ISR) after nitinol stenting in the superficial femoral artery (SFA). BACKGROUND: Few data are available regarding the performance of DUS for binary ISR based on quantitative vessel analysis (QVA) in the era of SFA nitinol stenting. METHODS: This retrospective study included 74 in-stent stenoses of SFA who underwent DUS before follow-up angiography. DUS parameters, such as peak systolic velocity (PSV) and the peak systolic velocity ratio (PSVR), were compared with percent diameter stenosis (%DS) from a QVA basis. RESULTS: There was a statistically significant correlation (P < 0.001) between "%DS and PSV" and "%DS and PSVR," and the correlation with %DS proved to be stronger in PSVR (R = 0.720) than in PSV (R = 0.672). The best performing parameter for ISR (50% or greater stenosis) was revealed PSVR, as the areas under the receiver operator characteristics curves using PSVR and PSV were 0.908 and 0.832, respectively. A PSVR cut off value of 2.85 yielded the best predictive value with sensitivity of 88%, specificity of 84%, and accuracy of 86%. The positive predictive value was 85% and the negative predictive value was 88%. CONCLUSIONS: A PSVR of 2.85 is the optimal threshold for ISR after nitinol stenting in the SFA. Further large prospective studies are required for the validation and establishment of uniform criteria for DUS parameters.

Subintimal angioplasty of lengthy femorotibial total occlusion in Buerger's disease.

PURPOSE: To report successful subintimal angioplasty of a lengthy femorotibial occlusion in a patient with Buerger's disease, with wound healing and limb salvage. CASE REPORT: A 38-year-old female heavy smoker was referred to our hospital for treatment of extensive infectious tissue loss, with severe foot pain 1 month after early failure of a distal bypass graft. Angiography revealed total occlusion in the femoropopliteal and infrapopliteal arteries. Endovascular recanalization was attempted in order to establish "straight-line flow" to the foot on the verge of limb loss. The subintimal angioplasty technique with a 0.014-inch hydrophilic guidewire facilitated successful crossing of the occlusive femoropopliteal and posterior tibial arteries. The lesions were serially dilated (standard and cutting balloons). Angiography demonstrated antegrade flow to the foot without flow-limiting dissection, and the serious pain dramatically disappeared. Complete wound healing was observed 5 months after initial revascularization with the assistance of repeat angioplasty for restenosis. CONCLUSION: Contemporary endovascular therapy using the subintimal angioplasty technique could represent a viable option for Buerger's disease.

Heterogeneous vascular response after implantation of bare nitinol self-expanding stents in the swine femoropopliteal artery.

BACKGROUND: Mechanism of femoropopliteal in-stent restenosis has been underappreciated. AIM: The aim of this animal study was to elucidate vascular response after femoropopliteal bare nitinol self-expanding stents (SESs) implantation. METHODS: Misago, Smart Flex, or Innova stent was randomly implanted in 36 swine femoropopliteal arteries. At week 4, quantitative vessel analysis (QVA) was performed on 36 legs, of which 18 underwent histological evaluation after angiography. The remaining 18 legs underwent QVA and histological evaluation at week 13. RESULTS: Fibrin deposition was excessive at week 4. Internal elastic lamina (IEL) progressively enlarged over time, and vessel injury developed from mild level at week 4 to moderate level at week 13. Vessel inflammatory reaction was mild to moderate at week 4, and was moderate to severe at week 13. Increased fibrin deposition was an early-acting, IEL enlargement and increased vessel inflammation were long-acting, and increased vessel injury and giant cells infiltration were late-acting contributors to neointimal hyperplasia (NIH). Stent type altered time-dependent process of vessel injury, vessel inflammation, eosinophils and giant cells infiltration. Misago had less fibrin deposition and vessel enlargement, and less progressive vessel injury, vessel inflammation, and eosinophils and giant cells infiltration. Net lumen as assessed by percent diameter stenosis or minimum lumen diameter was preserved with Misago, but was not preserved with the other stents. CONCLUSIONS: In the context of bare nitinol SES platform with less progressive mechanical stress and inflammatory reaction, the advantage of less NIH outweighed the disadvantage of less vessel enlargement, leading to net lumen preservation.

Predictors of adverse clinical outcomes after successful infrapopliteal intervention.

OBJECTIVES: To clarify the clinical and angiographical variables related to delayed wound healing, major amputation and death after successful infrapopliteal intervention in critical limb ischemia patients with tissue loss. BACKGROUND: There is an underappreciation of adverse clinical outcomes after successful infrapopliteal intervention. METHODS: Stent-assisted infrapopliteal angioplasty was successful in 106 limbs in 85 patients. Successful intervention was defined as revascularization of at least one straight-line flow to the foot. RESULTS: At 6 months and 1, 2, and 5 years, the repeat intervention-free rates were 55.0, 49.6, 44.4, and 36.1%, respectively; the amputation-free survival rates were 85.7, 68.0, 54.5, and 39.8%, respectively; and the limb salvage rates were 96.0, 92.4, 86.3, and 86.3%, respectively. An infectious wound was an independent predictor of major amputation after successful intervention. The complete wound healing rates were 36.8, 57.5, 67.9, and 73.6% at 3, 6, 9, and 12 months, respectively. In stepwise multivariate Cox analysis, diabetes mellitus, an infectious wound, and the pedal arch classification were identified as independent predictors of wound healing. The long-term survival rates at 6 months and 1, 2, and 5 years were 89.5, 73.8, 62.0, and 43.4%, respectively. Stepwise multivariate Cox analysis indentified end-stage renal disease (ESRD) on hemodialysis to be an independent predictor of death. CONCLUSIONS: An infectious wound, comorbidities of diabetes mellitus and ESRD on hemodialysis and classification of pedal arch can be predictors of adverse clinical outcomes after successful infrapopliteal intervention.