Below-the-Knee Endovascular Revascularization: A Position Statement

Patients with chronic limb-threatening ischemia, the terminal stage of peripheral artery disease, are frequently afflicted by below-the-knee disease. Although all patients should receive guideline-directed medical therapy, restoration of inline flow is oftentimes necessary to avoid limb loss. Proper patient selection and proficiency in endovascular techniques for below-the-knee revascularization are intended to prevent major amputation and promote wound healing. This review, a consensus among an international panel of experienced operators, provides guidance on these challenges from an endovascular perspective and offers techniques to navigate this complex disease process.

Endovascular and Surgical Venous Arterialization for No-Option Patients With Chronic Limb-Threatening Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is known for its high rates of major amputation and mortality. Conventional revascularization techniques often fail in CLTI patients due to the heavily diseased arteries. Foot vein arterialization (FVA) has been proposed as an alternative technique to provide arterial blood to the foot by using the disease-free venous bed.

OBJECTIVES

This systematic review and meta-analysis aimed to determine outcomes of surgical FVA (sFVA) and percutaneous FVA (pFVA) at 6 and 12 months post-procedure.

DATA SOURCES

PubMed, Scopus, Web of Science, and the Cochrane Library databases were searched to identify papers reporting clinical outcomes of sFVA and pFVA published between January 1966 and March 2023.

METHODS

Databases were searched for eligible studies. A meta-analysis was performed to evaluate the limb salvage rate, overall survival rate, and wound healing rate at 6 and 12 months.

RESULTS

A total of 27 studies were included, with 753 patients and 793 limbs. Of the included studies, 16 analyzed the sFVA technique and 11 the pFVA technique. Of the included patients, 86.3% were Rutherford 5/6 in the sFVA group versus 98.4% in the pFVA group. The pooled limb salvage rate at 6 and 12 months was 78.1% and 74.1% in the sFVA group and 81.7% and 78.6% in the pFVA group, respectively. Wound healing rates were not reported in the sFVA group. In the pFVA group, the pooled wound healing rates were 48.1% and 64.5% at 6 and 12 months, respectively.

CONCLUSION

This study showed promising results after FVA among a large population of CLTI patients. In high-risk patients, pFVA is a feasible option with favorable limb salvage and wound healing rates.

Postprocedural Management in Patients After Percutaneous Deep Venous Arterialization: An Expert Opinion

CLINICAL IMPACT

After percutaneous deep venous arterialization (pDVA), the created arteriovenous circuit needs time to develop. Postprocedural care in patients after pDVA is essential in order to create optimal conditions for maturation of the circuit, and thus save the limb. However, current literature mainly focusses on the procedure itself, making postprocedural care an underexposed topic. Therefore, this study presents an overview of the available literature of postprocedural care of pDVA patients and provides recommendations based on expert opinion when current knowledge is limited.

Clampless 2 Device: Experimental Study of a Lateral Aorto-Prosthetic Anastomosic Device Without Clamping or Suturing

BACKGROUND

To offer an alternative to conventional techniques of lateral prosthetic anastomosis on arteries which require a long training, and impose an extensive open surgery, we are proposing the clampless 2 device (C2D) implanted by a simple arterial puncture and allows a lateral implantation of a polytetrafluoroethylene (PTFE) vascular graft in an artery, without arterial clamping or suture.

METHODS

C2D is a "T" shaped 25-mm long and 8-mm diameter Nitinol stent with a 6-mm PTFE graft prosthesis mounted laterally on the stent, and implanted in an artery, via a 21-French sheath, and a compliant balloon inflation. In vitro testing of the C2D was first performed on a bench including a segment of a 7-mm internal diameter pig abdominal aorta. A series of 5 consecutive C2D implantation was analyzed with evaluation of the implantation time and the fluid losses at a fluid pressure of 80 and 150 mm Hg. The C2D implantation was finally controlled by angioscopy. An aorto-iliac bypass was then secondly performed on 8 living sows, with a side-to-end C2D implantation in the infrarenal abdominal aorta, followed by a conventional end-to-end prosthetic left iliac trunk anastomosis. The C2D and distal conventional anastomotic times were evaluated, as well as the total operative time and blood loss. A postoperative angiogram was systematically performed.

RESULTS

The C2D was successfully implanted in all 5 in vitro tests, with an average implantation time of 2'58 (range: 2'25-3'22). The mean value of fluid losses was 84 ml (range: 67-94 ml), with no fluid leakage occurring at 80- and 150-mm Hg pressure. All anastomoses were patent after macroscopic study by angioscopy with a perfect application of the stent in the aortic wall. In 8 living sows (mean weight: 42 kg, 37-50 kg), an aorto-left iliac bypass was successfully implanted in all cases, with a total mean procedure time of 101 min (range: 90-130 min), and an average fluid loss of 77 ml (range:20-120 ml). The mean implantation time was 4'39 (range 3'29-5'52) for C2D and 16 min (range 12-17 min) to perform the conventional distal prosthetic-iliac anastomosis. Systematic arteriographic and angioscopy control showed perfect patency of the C2D implantations.

CONCLUSIONS

Preliminary in vitro and acute in vivo testing of C2D implantation show good early results, allowing further long-lasting pig experiments on the way to human homologation.

Long-term outcomes after paclitaxel-coated balloon angioplasty of femoropopliteal arteries in Asian patients of the IN.PACT Global Study

OBJECTIVES

The long-term data on the use of drug-coated balloons (DCBs) for femoropopliteal atherosclerotic lesions in the real-world setting are limited, even more so for racially and geographically distinct populations. The present analysis reports the 5-year safety and effectiveness outcomes of a DCB in the Asian subset of the prospective, real-world IN.PACT Global Study.

METHODS

The IN.PACT Global Study was a prospective, multicenter, international, single-arm study designed to assess the long-term safety and effectiveness of the IN.PACT Admiral DCB in real-world participants with femoropopliteal artery disease. The present analysis included 114 Asian participants (138 lesions) treated in South Korea and Singapore. Assessments through 5 years included freedom from clinically driven target lesion revascularization, the safety endpoint (a composite of freedom from device- and procedure-related mortality through 30 days; and freedom from major target limb amputation and clinically driven target vessel revascularization within 60 months after the index procedure) and major adverse events.

RESULTS

In this prespecified Asian subset, there was a high incidence of diabetes mellitus (54.4%), hypertension (78.1%), coronary artery disease (43.9%), and concomitant below-the-knee vascular disease of target leg (39.5%). Mean lesion length was 17.4 ± 12.4 cm; 26.8% were in-stent restenosis, and more than half of the lesions were totally occluded (51.4%) and calcified (54.3%). The 5-year Kaplan-Meier estimate of freedom from clinically driven target lesion revascularization was 77.1% (95% confidence interval: 67.0%-84.5%). The safety composite endpoint was 76.0%; the cumulative incidence of all-cause mortality was 19.9%, and no major target limb amputations were reported through 5 years.

CONCLUSIONS

This subset analysis of Asian participants from the IN.PACT Global Study demonstrated consistent results with the previously reported data of the IN.PACT Admiral DCB. The data confirm the durable clinical effectiveness and safety profile of the DCB through 5 years for femoropopliteal atherosclerotic disease in this real-world population.

The Retrograde Basilic Approach for Balloon-Assisted Maturation of Brachiocephalic Arteriovenous Fistulas

PURPOSE

To assess the feasibility and outcomes of an approach utilizing transbasilic access for balloon-assisted maturation (BAM) of brachiocephalic arteriovenous fistulas (BCAVF).

MATERIALS AND METHODS

This retrospective analysis comprised 28 patients (mean age 63 years ± 10.8) who underwent endovascular treatment of their immature BCAVFs via a basilic approach from December 2016 to December 2018. The mean age of the BCAVF was 3.3 months ± 1.4 at time of BAM. Other demographic data, vascular access characteristics, procedural data, technical and clinical success rates and adverse events were also evaluated.

RESULTS

All patients had inflow juxta-anastomotic stenoses, with 4 patients (14%) having concomitant outflow tract stenoses, and 1 patient (4%) having a short segment occlusion at the stenotic juxta-anastomotic segment. Technical success was achieved in 27 patients (96%). The mean diameter of the largest balloon used was 5.7mm ± 0.6. Clinical success was achieved in 22 patients (79%), with 6 patients (21%) requiring a subsequent additional intervention before successful cannulation. No perioperative adverse events were observed.

CONCLUSION

The retrograde basilic approach is feasible, safe and effective for balloon-assisted maturation of BCAVFs.

Development of a Prediction Model for the Occurrence of Stenosis or Occlusion after Percutaneous Deep Venous Arterialization

Percutaneous deep venous arterialization (pDVA) is a promising treatment option in patients with chronic limb-threatening ischemia. Stenosis and occlusions, which are the Achilles’ heel of every revascularization procedure, can be treated when detected early. However, frequent monitoring after pDVA is required because when stenosis or occlusions develop is unknown. Therefore, patients currently need to visit the hospital every 2 weeks for surveillance, which can be burdensome. Accordingly, we aimed to develop a model that can predict future stenosis or occlusions in patients after pDVA to be able to create tailor-made follow-up protocols. The data set included 343 peak systolic velocity and 335 volume flow measurements of 23 patients. A stenosis or occlusion developed in 17 patients, and 6 patients remained lesion-free. A statistically significant increase in the risk of stenosis or occlusion was found when duplex ultrasound values decreased 20% within 1 month. The prediction model was also able to estimate a patient-specific risk of future stenosis or occlusions. This is promising for the possibility of reducing the frequency of follow-up visits for low-risk patients and increasing the frequency for high-risk patients. These observations are the starting point for individual surveillance programs in post-pDVA patients. Future studies with a larger cohort are necessary for validation of this model.

Outcomes of the paclitaxel-eluting Eluvia stent for long femoropopliteal lesions in Asian patients with predominantly chronic limb-threatening ischemia

The fluoropolymer-coated, paclitaxel-eluting Eluvia stent has shown promising results for the endovascular treatment of femoropopliteal artery lesions in patients with claudication. The aim of the current study was to evaluate efficacy and safety outcomes of the Eluvia stent for the treatment of long femoropopliteal lesions in Asian patients. This is a single-center, retrospective study. The primary endpoint was primary patency at 1 year. Secondary outcomes were 30-days complication rate, technical success, 1-year freedom from clinically driven target lesion revascularization (CD-TLR), limb salvage, survival, amputation-free survival (AFS), wound healing, and clinical improvement. A total of 64 patients with 67 femoropopliteal lesions were included; 78% suffered from diabetes and 84% had chronic limb-threatening ischemia (CLTI). Of those with ischemic wounds, 79% did not have run-off to the foot. Mean lesion length was 193 ± 128 mm and 52% were severely calcified. Primary patency at 1 year was 84% in the overall cohort and 91% in patients with complete lesion coverage with the Eluvia stent. Technical success was achieved in 100% of the cases and 30-day complications occurred in six patients. Twelve-month freedom from CD-TLR, limb salvage, survival, and AFS were 92%, 93%, 85%, and 80%, respectively. In 80% of patients, complete wound healing was experienced and 84% had clinical improvement after 1 year. The Eluvia stent showed promising 12-month patency and clinical results for femoropopliteal treatment in this CLTI-dominant patient population with severely calcified, long lesions. Patient numbers were, however, small; larger trials are required to validate these findings. Aneurysmal change seen in some cases also needs further investigation.

Mid-term outcomes of an everolimus-eluting bioresorbable vascular scaffold in patients with below-the-knee arterial disease: A pooled analysis of individual patient data

Previous studies on everolimus-eluting bioresorbable vascular scaffolds (BVS) have shown promising 1-year primary patency rates in infrapopliteal arteries. Literature from large cohorts on long-term outcomes with the infrapopliteal Absorb BVS (Abbott Vascular) is lacking. The aim of this study is to pool published and unpublished data to provide a more precise estimate of the 24-month outcomes of Absorb BVS for the treatment of infrapopliteal disease. For the pooled analysis, updated original and newly collected data from three cohorts on treatment with the Absorb BVS for de novo infrapopliteal lesions were combined. The primary endpoint was freedom from restenosis. Secondary endpoints were freedom from clinically driven target lesion revascularization (CD-TLR), major amputation and survival. The pooled analysis included a total of 121 patients with 161 lesions, treated with 189 Absorb BVS in 126 limbs. The mean age of the patients was 73 years, 57% had diabetes mellitus, and 75% were classified as Rutherford-Becker class 5 or 6. Of the 161 lesions, 101 (63%) were calcified and 36 (22%) were occlusions. Successful deployment was achieved with all scaffolds. Freedom from restenosis was 91.7% and 86.6% at 12 and 24 months, respectively, and freedom from CD-TLR was 97.2% and 96.6%. Major amputation occurred in 1.6% of the limbs. Overall survival was 85% at 24 months. In conclusion, this pooled analysis represents the largest reported analysis of mid-term results of the Absorb BVS for the management of chronic limb-threatening ischemia. At 24 months, the Absorb BVS was safe with promising clinical outcomes for the treatment of infrapopliteal disease.

A systematic review and meta-analysis of bioresorbable vascular scaffolds for below-the-knee arterial disease

INTRODUCTION

Different types of bioresorbable vascular scaffolds (BVSs) have been developed and used in below-the-knee (BTK) arterial diseases. This is the first study reviewing and analyzing the literature on BVS treatment for BTK arterial disease.

EVIDENCE ACQUISITION

MEDLINE, Embase, and Cochrane were searched for studies published until October 21, 2019. The search, study selection, quality assessment, and data extraction were performed by 2 authors independently. Articles that studied the treatment of BTK arterial disease by using BVSs were eligible. Exclusion criteria were studies with a variant design (e.g. case reports <5 patients), non-BTK indications for BVS use, and nonhuman studies. Primary endpoint was 12-month primary patency. Secondary endpoints were 12-month freedom from clinically driven target lesion revascularization (CD-TLR), limb salvage, survival, and amputation-free survival (AFS). Study quality was assessed by the Methodological Index for Non-randomized Studies score.

EVIDENCE SYNTHESIS

Five studies representing 155 patients with 160 treated limbs met the inclusion criteria. Pooled 12-month primary patency per limb was 90% (143/160; 95% confidence interval [CI]: 0.84-0.95), freedom from CD-TLR 96% (124/130; 95% CI: 0.91-0.99), limb salvage rate 97% (156/160; 95% CI: 0.94-1.00), survival rate 90% (112/125; 95% CI: 0.82-0.96), and AFS rate 89% (110/125; 95% CI: 0.81-0.94). Subgroup analyses of included Absorb BVS studies showed similar results. All studies were assessed as moderate quality.

CONCLUSIONS

This meta-analysis of case series showed good 12-month patency and clinical results with BVSs for BTK arterial disease, even in patients with multimorbidity and short but complex lesions. These results encourage a revival of this scaffold.

Volume Flow and Peak Systolic Velocity of the Arteriovenous Circuit in Patients after Percutaneous Deep Venous Arterialization

Percutaneous deep venous arterialization (pDVA) is a developing technique for limb salvage in patients with chronic limb-threatening ischemia by creating an arteriovenous (AV) circuit. After pDVA, patency of the AV circuit is evaluated using duplex ultrasound (DUS) imaging. Peak systolic velocity (PSV) and volume flow (VF) values for maintaining a patent AV circuit are undefined; therefore, guidance about when a reintervention should be performed is lacking. The objective of this study was to interpret post-pDVA PSV and VF values in relation to AV circuit preservation. This was performed by analyzing DUS results of 22 post-pDVA patients. A total of 670 PSV and 623 VF measurements were collected. A PSV value of ≤55 cm/s and a VF value of ≤195 mL/min were found predictive for failure. The reliability of PSV and VF measurements in patent AV-circuits was good (intraclass correlation coefficient; PSV, 0.85; VF, 0.88). In conclusion, this study is the first to analyze DUS measurements in post-pDVA patients and showed that DUS can be used to anticipate for failure. The thresholds found can be used to help interpret DUS measurements in post-pDVA patients. More research in a larger patient population is needed to prospectively validate these thresholds.

Novel technique of percutaneous bypass in a brachiocephalic arteriovenous fistula with cephalic arch occlusion: A case report

OBJECTIVE

Arteriovenous fistulas are a principal mainstay of long-term dialysis access for patients with end stage renal failure. However, the patency of arteriovenous fistulas is limited, often requiring percutaneous transluminal angioplasty as a salvage procedure. We report a case of percutaneous method of arteriovenous fistula salvage.

METHODS

A gentleman with brachiocephalic arteriovenous fistula created in 2015 was admitted under us for dialysis access issue. His fistula history was notable for recurrent and refractory venous outflow stenosis of the cephalic vein and the cephalic arch with multiple previous interventions. Ultrasound showed cephalic arch occlusion with high venous pressures. He underwent left brachicephalic fistula percutaneous bypass. We describe the percutaneous creation of a brachial-subclavian arteriovenous fistula via a bypass graft from a worsening brachial-cephalic fistula with cephalic arch occlusion that is not amendable to angioplasty.

RESULTS

Final angiogram showed smooth flow to central vein. He is 2 years post procedure, and his fistula remained patent with no interventions required.

CONCLUSION

Percutaneously created jump bypass grafts can reliably produce sustained long-term patency.

The direct extravascular calcium interruption arterial procedure technique for heavily calcified vessels

Severely calcified lesions continue to plague endovascular interventions by negatively affecting the acute and long-term results. A new technique was developed to allow balloon crossing or to treat persistent recoil. In the direct extravascular calcium interruption arterial procedure technique, an artery forceps is percutaneously introduced to modify the plaque after conventional techniques have failed. In this initial experience, the direct extravascular calcium interruption arterial procedure technique was successful as a bailout option in patients in whom balloon crossing was impossible or recoil was untreatable even with high-pressure balloons.

Early and Midterm Experience With the Absorb Everolimus-Eluting Bioresorbable Vascular Scaffold in Asian Patients With Chronic Limb-Threatening Ischemia: One-Year Clinical and Imaging Outcomes From the DISAPEAR Registry

Purpose: To report an experience with the Absorb bioresorbable vascular scaffold (BVS) in an Asian cohort with chronic limb-threatening ischemia (CLTI) from the DISAPEAR ( Drug Impregnated Bioresorbable Stent in Asian Population Extremity Arterial Revascularization) registry. Materials and Methods: A retrospective analysis was conducted of 41 patients (median age 64 years; 23 men) with CLTI owing to >50% de novo infrapopliteal lesions (n=53) treated with the Absorb BVS between August 2012 and June 2017. The majority of patients (37, 90%) had diabetes, 24 (59%) had ischemic heart disease, and 39 (95%) had Rutherford category 5/6 ischemia with tissue loss. The mean lesion length was 22.7±17.2 mm; 10 (24%) lesions were severely calcified. Assessments included technical success, primary patency, freedom from clinically-driven target lesion revascularization (CD-TLR), amputation-free survival, limb salvage, complete wound healing, resolution of rest pain, and resolution of CLTI without TLR at 6 and 12 months after the index intervention. Results: Overall, 69 scaffolds were implanted in the 53 lesions, with 100% technical success. There were no deaths within 30 days of the index procedure. The primary patency rates at 6 and 12 months were 95% and 86%, respectively. The corresponding rates of freedom from CD-TLR were 98% and 93%, respectively. Freedom from major amputation was 98% at both time points, and amputation-free survival was 93% and 85% at 6 and 12 months after the index procedure. Wound healing occurred in 31 patients (79%) with Rutherford category 5/6 ischemia by the end of 12 months. Conclusion: The Absorb BVS demonstrated good 1-year patency and clinical outcomes in CLTI patients with complex infrapopliteal disease.

Midterm Outcomes of Percutaneous Deep Venous Arterialization With a Dedicated System for Patients With No-Option Chronic Limb-Threatening Ischemia: The ALPS Multicenter Study

Purpose: To evaluate the midterm results of patients suffering from no-option chronic limb-threatening ischemia (CLTI) treated with a dedicated system for percutaneous deep venous arterialization (pDVA). Materials and Methods: Thirty-two consecutive CLTI patients (mean age 67±14 years; 20 men) treated with pDVA using the Limflow device at 4 centers between 11 July 2014 and 11 June 2018 were retrospectively analyzed. Of all patients, 21 (66%) had diabetes, 8 (25%) were on immunosuppression, 4 (16%) had dialysis-dependent renal failure, 9 (28%) had Rutherford category 6 ischemia, and 25 (78%) were deemed at high risk of amputation. The primary outcome was amputation-free survival (AFS) at 6 months. Secondary outcomes were wound healing, limb salvage, and survival at 6, 12, and 24 months. Results: Technical success was achieved in 31 patients (96.9%). The median follow-up was 34 months (range 16-63). At 6, 12, and 24 months, estimates were 83.9%, 71.0%, and 67.2% for AFS, 86.8%, 79.8% and 79.8% for limb salvage, and 36.6%, 68.2%, and 72.7% for complete wound healing, respectively. Median time to complete wound healing was 4.9 months (range 0.5-15). The DVA circuit occluded during follow-up in 21 patients; the median time to occlusion was 2.6 months. Reintervention for occlusion was performed in 17 patients: 16 because of unhealed wounds and 1 for a newly developed ulcer. Conclusion: This study represents the largest population of patients with no-option CLTI treated with pDVA using the LimFlow device with midterm results. In this complex group of patients, pDVA using the LimFlow device has been shown to be feasible, with a high technical success rate and AFS at 6 up to 24 months coupled with wound healing. In selected patients with no-option CLTI, pDVA could be a recommended treatment to prevent amputation and heal wounds.

High-pressure, non compliant balloon angioplasty for long and calcified infrapopliteal and inframalleolar lesions is feasible

BACKGROUND

To evaluate the safety, feasibility and effectiveness of high-pressure, noncompliant balloon angioplasty in the management of long infrapopliteal calcified lesions.

METHODS

Consecutive patients, presenting with chronic limb-threatening ischemia (CLTI) and long (>100 mm) calcified infrapopliteal lesions who were treated with a high pressure, noncompliant balloon (JADE, OrbusNeich, Hong Kong) between January 2016 and July 2016 were retrospectively analyzed. Angioplasty was performed by inflating the balloon to a pressure of 22 to 24 atm for 90 seconds. Primary outcome was technical success. Secondary outcomes were procedure-related complications, limb salvage, amputation-free survival (AFS), wound healing, overall survival, freedom from clinically driven target lesion reintervention (CD-TLR), and resolution of CLTI at 2 and 3 years.

RESULTS

Overall, 23 lesions in 21 limbs of 20 patients were treated. All patients had tissue loss (Rutherford 5 or 6). The mean lesion length was 374.8 mm. Of all lesions, 56.5% were occlusions, 91.3% were classified as TransAtlantic Inter-Society Consensus (TASC) C and D lesions, and 78.3% had severe calcification classification. Of all lesions, 52.2% extended into the below-the-ankle arteries. Technical success was achieved in 22 lesions (95.7%). There were no procedure-related complications. No bailout stenting was required. At 2 and 3 years, limb salvage was 84.7% and 78.7%, AFS was 71.4% and 56.1%, wound healing was 81.0% and 85.7%, overall survival was 75.0% and 64.3% and freedom from CD-TLR was 77.6% and 63.5%, respectively. Resolution of CLTI without TLR was 81.0% at 2 and 3 years.

CONCLUSIONS

This study is the first to analyze safety and feasibility of a high-pressure, noncompliant balloon for long, calcified infrapopliteal and inframalleolar lesions.

PROMISE international; a clinical post marketing trial investigating the percutaneous deep vein arterialization (LimFlow) in the treatment of no-option chronic limb ischemia patient

BACKGROUND

Critical limb ischemia (CLI) is the clinical end stage of peripheral artery disease and is associated with high amputation, mortality rates and poor quality of life. For CLI patients with no revascularization options, venous arterialization could be an alternative technique for limb salvage. A systematic review and meta-analysis published in 2017 concluded that venous arterialization may be considered a viable alternative. A recent development, is the Percutaneous Deep Vein Arterialization (pDVA), that is CE-marked and currently under investigation of the FDA. This procedure, called LimFlow, is a novel, minimally invasive, endovascular approach to perform a venous arterialization procedure. The limited evidence for its use necessitates a scientific judgement of the pDVA. Therefore, we initiated a prospective clinical post market trial to investigate the outcome of the pDVA in no-option critical limb ischemia.

METHODS/DESIGN

The objective of this prospective study is to collect "real-life" clinical data among a population of patients treated with the pDVA in order to evaluate the clinical effectiveness and safety of the LimFlow System in patients with no-option critical limb ischemia. This study is a single-arm, open-label, prospective, post-market follow-up study to be conducted on up to fifty (50) eligible patients with a twelve-month follow-up period. The Primary endpoint is measured by amputation free survival. Secondary endpoints are complete wound healing, primary and secondary patency, limb salvage, renal function and technical and procedural success. Patients will be assessed at regular intervals during one year after the initial percutaneous deep vein arterialization procedure through clinical evaluation and self-completed questionnaires.

DISCUSSION

The last decade several studies have been published with promising results and the number of treated patients has considerably grown. Venous arterialization could be a valuable treatment option in patients with often no other options than amputation of the affected limb. The first results in men are promising although more research and long term follow up is needed to establish the efficacy of this new treatment modality. With this prospective study, we evaluate the clinical effectiveness and safety in patients with no-option CLI treated with the pDVA (LimFlow System).

TRIAL REGISTRATION

NCT03321552 .

Novel Use of Capturex Device and Reliant Balloon for Inferior Vena Cava Tumor Thrombectomy: A Case Report and Review of Literature

Introduction:

Most common tumor extending into the inferior vena cava (IVC) are renal carcinomas, such extension have been noted in nearly one-fifth of tumors. Tumor thrombectomy improves the prognosis of patients including those with extension of tumor as far as supra hepatic vena cava. In contrast, if radical nephrectomy is performed as the sole procedure, the prognosis is reduced drastically.

Case Presentation:

We present a case of a 42-year-old male who presented to us with renal cell carcinoma with tumor thrombus extending to IVC. We performed a hybrid endovascular and open procedure using novel surgical techniques to obtain proximal vena caval control and to remove the tumor thrombus—Capturex filter which was placed endovascularly 1 cm above the thrombus via the right internal jugular vein and reliant balloon was placed above the capturex below the hepatic veins. At this position, when the reliant balloon was inflated, it acted as a retro hepatic IVC control. Following vascular control, we proceeded to tumor thrombectomy and radical nephrectomy using transperitoneal approach. Patient made an uneventful recovery and was subsequently referred for medical oncology service for consideration of targeted therapy. Detailed description of the procedure is followed by the discussion of the literature.

Hybrid Foot Vein Arterialization in No-Option Patients With Critical Limb Ischemia: A Preliminary Report

PURPOSE

To describe a preliminary experience in treating no-option critical limb ischemia (CLI) patients with a hybrid foot vein arterialization (HFVA) technique combining open plus endovascular approaches.

MATERIALS AND METHODS

Between May 2016 and January 2018, 35 consecutive patients (mean age 68±12 years; 28 men) with 36 no-option CLI limbs underwent HFVA in our center. All limbs had grade 3 WIfI (Wound, Ischemia, and foot Infection) ischemia, and the wound classification was grade 1 in 4 (11%) limbs, grade 2 in 4 (11%), and grade 3 in 28 (78%). Surgical bypass was done on the medial marginal vein or a posterior tibial vein, followed by endovascular removal of foot vein valves and embolization of foot vein collaterals. A "tension-free" surgical approach was used to treat foot lesions.

RESULTS

At a mean follow-up of 10.8±2 months, limb salvage was achieved in 25 (69%) limbs and wound healing in 16 (44%); 9 patients presented an unhealed wound. Eleven (31%) patients underwent a major amputation (2 below the knee and 9 thigh). One patient with an unhealed wound and open bypass died of myocardial infarction.

CONCLUSION

HFVA is a promising technique able to achieve acceptable rates of limb salvage and wound healing in no-option patients generally considered candidates for an impending major amputation. Further studies are needed to standardize the technique and better identify patients who can benefit from this approach.

Correction to: Percutaneous Deep Venous Arterialization for Severe Critical Limb Ischemia in Patients With No Option of Revascularization: Early Experience From Two European Centers

The fifth author's name was incorrectly published as "M. Messas". The correct name is "E. Messas". The original article has been corrected.

Percutaneous deep venous arterialization in patients with critical limb ischemia

BACKGROUND

Critical limb ischemia (CLI) is the presentation of end stage peripheral arterial disease and typically presents with rest pain, ulceration and gangrene. The outcome of conservative treatment is poor and often leads to amputations. Arterial revascularization plays an important role in amputation prevention. Unfortunately, a significant percentage of CLI patients cannot be revascularized and subsequently end up with a palliative amputation. This has led to the need and exploration of new treatment options in this no option subgroup of CLI. Deep venous arterialization (DVA) is one of them and has been reported as a save and feasible novel and promising alternative to amputation. The goal of DVA is to provide arterialized blood in significant volumes and pressure to the plantar venous arch and ischemic tissue to enable wound healing. Selecting the right patients is critical for successful DVA and requires that extra attention is paid to the wounds as well as arterial and venous vascular status.

METHODS

The procedure was previously described in our initial experience in the first-in-man study performed on 7 patients with NOP-CLI. The angiographic goal of the procedure is to deliver arterialized blood to the plantar venous arch in significant volumes and pressure, circumventing the numerous valves in the process. The clinical goal is to achieve wound healing.

RESULTS

Technical success was achieved in all patients. Flow in the plantar arch was achieved in 5 of the 7 patients. One patient with chronic rest pain became pain free within 48 hours after the procedure. Complete wound healing was achieved at 12 months in 5 of the 7 patients. Reinterventions were performed in 5 of 7 patients to maintain patency. Of the 7 study patients, five underwent minor amputation of one or more toes, and two underwent major amputations within 12 months (limb salvage, 71%).

CONCLUSIONS

The LimFlow system is currently the only registered device a total percutaneous DVA can be performed with. In addition to the percutaneous creation of an arteriovenous fistula (AVF), it also allows disruption of the veins with a dedicated valvulotome.

Complete resolution of extensive thrombosis of atheromatous non-aneurysmal descending aorta and pulmonary embolism with warfarin therapy

A 54-year-old man underwent decompressive craniectomy following a stroke. He further developed right lower limb ischaemia, and CT aortography revealed extensive aortic atherosclerotic disease. Urgent embolectomy prevented him from having a major amputation. He subsequently developed pulmonary embolism. This was initially treated with heparin followed by warfarin apart from antiplatelets and statin. A follow-up aortography at 3 months interval showed near complete resolution of atheromatous disease of the aorta. This report raises the possibility that apart from antiplatelets and lipid-lowering agents, anticoagulation may be responsible for resolution of such an extensive atheromatous disease and whether this can be considered as part of regular treatment.

ClariVein™ - One year results of mechano-chemical ablation for varicose veins in a multi-ethnic Asian population from Singapore

OBJECTIVES

This study assessed the effectiveness and patient experience of ClariVein for varicose veins and chronic venous insufficiency (CVI) in a multi-ethnic Asian population from Singapore.

METHODS

A total of 121 patients underwent mechano-chemical ablation. Patients were reviewed at an interval of one week, and at 3, 6 and 12 months post procedure and underwent Duplex ultrasound with patient satisfaction assessment.

RESULTS

At three months of follow-up, the great saphenous vein and short saphenous vein occlusion rates were 90.8% and 96.0%, respectively. At six months of follow-up, the GSV and short saphenous vein occlusion rates were 86.9% and 90.9%, respectively. At one year, great saphenous vein and short saphenous vein occlusion rates were 84.8% and 94.3%, respectively.

CONCLUSIONS

Early results are similar to what is described so far in the mechano-chemical ablation literature but recurrences are more than expected at one year. This is disappointing but is tempered by the fact that the majority of patients were asymptomatic and required no reintervention.

Surgical and endovascular venous arterialization for treatment of critical limb ischaemia

Patients with critical limb ischaemia have a poor life expectancy. Aggressive revascularization is accepted in order to preserve their independence in the final phase of their lives. Bypass surgery and more recently endovascular interventions with angioplasty and stenting have become the treatment of choice to prevent amputation and to resolve pain. However, as many as 20 % of patients with critical limb ischaemia are unsuitable candidates for a vascular intervention because of extensive occlusions of outflow in the crural and pedal vessels. Such "no-option critical limb ischaemia" may be treated with venous arterialization. In the present review, we discuss the history of the venous arterialization procedure, the mechanisms, the different techniques, and complications of venous arterialization.

Midterm Outcomes From a Pilot Study of Percutaneous Deep Vein Arterialization for the Treatment of No-Option Critical Limb Ischemia

PURPOSE

To report the initial clinical experience with percutaneous deep vein arterialization (PDVA) to treat critical limb ischemia (CLI) via the creation of an arteriovenous fistula.

METHODS

Seven patients (median age 85 years; 5 women) with CLI and no traditional endovascular or surgical revascularization options (no-option CLI) were recruited in a pilot study to determine the safety of PDVA. All patients were diabetic; 4 had Rutherford category 6 ischemia. Six were classified at high risk of amputation based on the Society for Vascular Surgery WIfI (wound, ischemia, and foot infection) classification. The primary safety endpoints were major adverse limb events and major adverse coronary events through 30 days and serious adverse events through 6 months. Secondary objectives included clinical efficacy based on outcome measures including thermal measurement, transcutaneous partial pressure of oxygen (TcPO₂), clinical improvement at 6 months, and wound healing.

RESULTS

The primary safety endpoints were achieved in 100% of patients, with no deaths, above-the-ankle amputations, or major reinterventions at 30 days. The technical success rate was 100%. Two myocardial infarctions occurred within 30 days, each with minor clinical consequences. All patients demonstrated symptomatic improvement with formation of granulation tissue, resolution of rest pain, or both. Complete wound healing was achieved in 4 of 7 patients and 5 of 7 patients at 6 and 12 months, respectively, with a median healing time of 4.6 months (95% confidence interval 84-192). Median postprocedure peak TcPO₂ was 61 mm Hg compared to a preprocedure level of 8 mm Hg (p=0.046). At the time of wound healing, 4 of 5 of patients achieved TcPO₂ levels of >40 mm Hg. There were 2 major amputations, 1 above the knee after PDVA thrombosis and 1 below the knee for infection. Three patients died of causes unrelated to the procedure or study device at 6, 7, and 8 months, respectively. Limb salvage was 71% at 12 months.

CONCLUSION

PDVA is an innovative approach for treating no-option CLI and represents an alternative option for the "desert foot," potentially avoiding major amputation. Our results demonstrate its safety and feasibility, with promising early clinical results in this small cohort.

Lessons Learned Regarding Handling and Deployment of the Absorb Bioresorbable Vascular Scaffold in Infrapopliteal Arteries

Purpose: To describe relevant technical details with which to facilitate safe and effective use of the Absorb coronary bioresorbable vascular scaffold (BVS) in lower extremity arteries. Technique: The Absorb BVS is a balloon-expandable, poly-l-lactide structure covered in a poly-d,l-lactide bioresorbable polymer that contains the antiproliferative drug everolimus. As a polymeric structure, it has a number of unique physical, handling, and imaging properties that may differ from metallic stents and pose a challenge to the interventionist. Attention must be paid to lesion selection, preparation, scaffold sizing, deployment, and postdilation to achieve optimal outcomes. A detailed description of these issues and deployment techniques is offered based on experience using this BVS in below-the-knee arteries. Conclusion: The Absorb BVS may have application in the infrapopliteal circulation; however, its unique properties warrant careful consideration before use in the lower limb.

Surgical and endovascular venous arterialization: ready to take the "desert" by storm?

Patients with critical limb ischemia have a poor life expectancy, and aggressive revascularization is accepted to maintain their independence in the end stage of life. Bypass surgery and, more recently, endovascular interventions with angioplasty and stenting have become the treatment of choice to prevent amputation and resolve rest pain. Up to 20% of patients with critical limb ischemia are not suitable candidates for a vascular intervention because of extensive occlusions of the outflow in the crural and pedal vessels. This "desert foot" can be treated with a venous arterialization. In this review, we discuss the mechanism, the techniques, outcome, and complications of venous arterialization.

Venous Arterialisation for Salvage of Critically Ischaemic Limbs: A Systematic Review and Meta-Analysis

BACKGROUND

Critical limb ischaemia (CLI) is the end stage of peripheral artery disease (PAD) and is associated with high amputation and mortality rates and poor quality of life. For CLI patients with no revascularisation options, venous arterialisation could be a last resort for limb salvage.

OBJECTIVE

To review the literature on the clinical effectiveness of venous arterialisation for lower limb salvage in CLI patients with no revascularisation options.

METHOD

Different databases were searched for papers published between January 1966 and January 2016. The criteria for eligible articles were studies describing outcomes of venous arterialisation, published in English, human studies, and with the full text available. Additionally, studies were excluded if they did not report limb salvage, wound healing or amputation as outcome measures. The primary outcome measure was post-operative limb salvage at 12 months. Secondary outcome measures were 30 day or in-hospital mortality, survival, patency, technical success, and wound healing.

RESULTS

Fifteen articles met the inclusion criteria. The included studies described 768 patients. According to the MINORS score, methodological quality was moderate to poor. The estimated pooled limb salvage rate at one year was 75% (0.75, 95% CI 0.70-0.81). Thirty day or in-hospital mortality was reported in 12 studies and ranged from 0 to 10%. Overall survival was reported in 10 studies and ranged from 54% to 100% with a mean follow-up ranging from 5 to 60 months. Six studies reported on patency of the venous arterialisations performed, with a range of 59-71% at 12 months.

CONCLUSION

In this systematic review on venous arterialisation in patients with non-reconstructable critical limb ischaemia, the pooled proportion of limb salvage at 12 months was 75%. Venous arterialisation could be a valuable treatment option in patients facing amputation of the affected limb; however, the current evidence is of low quality.

Effects of formaldehyde and xylene on CD4- and CD8-positive T cells in bronchus-associated lymphoid tissue in rats

The aim of this study was to determine the localization and number of CD4- and CD8-positive T lymphocytes in bronchus-associated lymphoid tissue (BALT) of the embryos and newborns or young and adult rats exposed to formaldehyde (6 ppm), technical xylene (300 ppm), or a combination of these two agents (3 ppm + 150 ppm) for 6 weeks (8 h/day). A total of 96 female Sprague-Dawley rats were used. The CD4-positive cells were localized predominately in area under the epithelium and in the periphery of BALT follicles after the exposure period. However, CD8-positive cells were localized mainly in the periphery of BALT follicles after the exposure period. The number of CD4- and CD8-positive lymphocytes significantly increased in exposed young and adult rats compared to the respective controls. These results suggest that formaldehyde and/or xylene may affect the local immunity in BALT particularly in young and adult rats.

The several elements of intestinal innate immune system at the beginning of the life of broiler chicks

Functional capacity of digestive system and intestinal adaptive immunity are immature at hatching of broiler chicks. Therefore, intestinal innate immunity after hatching is vital to young chicks. The purpose of this study was to investigate expression and tissue distributions of several elements of the innate immune system (i.e., TLR2, TLR4, CD83, and MHC class II expressing cells) in the intestine of one-day-old chicks. For this purpose, ileum and cecum were examined the under different conditions, which included the control and 1, 3, 6, 12, or 24 h after injection of lipopolysaccharide (LPS) and phosphate buffered saline. The findings indicated that regardless of the antigenic stimulation, Toll-like receptor (TLR) 2 and TLR4 expressing cells were present in the intestinal tissues of one-day-old chicks. We noticed that the intestinal segments have different TLR expression levels after LPS stimulation. Dendritic cells were identified, and they left the intestinal tissue after LPS treatment. MHC class II molecules were diffusely present in both the ileum and cecum. This study demonstrates that the intestinal tissue of one-day-old chicks has remarkable defensive material, including histological properties and several elements of the innate immune system. Microsc. Res. Tech. 79:604-614, 2016. © 2016 Wiley Periodicals, Inc.

The open retrograde approach as an alternative for failed percutaneous access for difficult below the knee chronic total occlusions-A case series

Retrograde puncture via patent pedal vessels can be attempted in failed antegrade approach for infrapopliteal long chronic total occlusion. However in cases where the pedal vessels are unable to be visualized via duplex ultrasonography or fluoroscopy an open approach offers an additional option to a vascular surgeon for successful recanalization. Our case report highlights 3 cases where successful hybrid open retrograde approach was able to achieve recanalization of long chronic total occlusion.

Presentation of cases

The three cases in our series presented with critical limb ischaemia. All three cases had undergone duplex imaging of the affected arterial system. As the antegrade approach to cross the lesion failed a retrograde approach was attempted in all 3 cases. However when the usual modality of retrograde puncture via the use of ultrasound or fluoroscopy failed we proceeded with an open approach.

Discussion

Retrograde approach usually offers a better chance of successfully crossing a chronic total occlusion lesion. However puncturing a distal vessel successfully and traversing a catheter or guidewire across proves to be a challenge. An open approach offers an additional pathway for puncturing the target vessel when duplex imaging or fluoroscopic guidance fails.

Conclusion

Open approach is usually attempted as a last resort by many endovascular surgeons. However procedural time, contrast and radiation usage could have been cut short in cases where the distal target vessels pose a technical challenge for approach via a percutaneous method.

A Histochemical Investigation of Different Distribution of TSH Cells in Adenohypophsis of Female and Male Rats

The aim of the present study was to investigate histochemically the localization of thyroid-stimulating hormone (TSH) cells and the number of TSH cells in adenohypophysis of ovariectomized adult females, intact females at estrous and diestrous phase of sexual cycles and castrated and non-castrated adult male rats. TSH cells, distributed throughout the pars distalis in all groups, were observed more frequent in areas near to the pars intermedia than other regions. The cells were round, ovoid, stellar-shaped and had contacts with sinusoids. Their nuclei were large and round-shaped. The cells were found mostly single or occasionally in groups of double and triple. The number of TSH cells was higher in estrous than diestrous phase in intact rats. In adenohypophysis of ovariectomized rats, their numbers were less than that of intacts in estrous, but higher than that of found in diestrous phases. Furthermore, the numbers of TSH cells in intact females during estrous phase was higher than those found in intact and castrated male rats. On the other hand, castration reduced the number of TSH cells while ovariectomy had no effect in this respect.