Mean Occlusion Length Research Articles

Retrograde Transpopliteal Recanalization of Chronic Superficial Femoral Artery Occlusion After Failed Re-Entry During Antegrade Subintimal Angioplasty

To evaluate the acute success and clinical impact of retrograde transpopliteal access for subintimal recanalization of superficial femoral artery (SFA) and proximal popliteal artery (PA) occlusions after failed attempts to re-enter the true lumen in the antegrade femoral approach. From 2002 to 2007, 56 patients (43 men; mean age 68+/-9 years, range 43-87) with stable chronic peripheral artery disease (Rutherford category 2 to 5) were treated with antegrade subintimal angioplasty that could not be completed owing to re-entry failure. Mean occlusion length was 17+/-7 cm (range 4-32), including 13 TASC II A (23.2%), 10 TASC II B (17.8%), 16 TASC II C (28.5%), and 17 TASC II D (30.3%) lesions. After re-entry to the true lumen failed in the antegrade approach, including predilation of the false channel, all patients were turned to a prone position, and a 5-F or 6-F sheath was placed into the mid segment of the PA under fluoroscopic guidance. Retrograde wire passage was attempted with a 0.035-inch hydrophilic guidewire. Fifty-five (98.2%) of 56 procedures were finished successfully with a residual stenosis of <30%; the 1 failure was due stent deformation within the occluded segment that could not be passed from either an antegrade or retrograde access. In all interventions, balloon angioplasty was performed; provisional stenting was done in 40 (71.4%). In 3 (5.3%) lesions, additional excimer laser atherectomy were performed. Six (10.7%) complications occurred, including 1 arteriovenous fistula from the PA to the popliteal vein and 1 sealing device induced PA occlusion. The mean ankle-brachial index increased from 0.44+/-0.26 to 0.86+/-0.23. The restenosis rate after 12 months was 54.9%. Failed antegrade attempts to recanalize chronic total occlusions of the SFA and proximal PA can be salvaged using a retrograde popliteal access, with a low complication rate, as an alternative to using a re-entry device. However, durability of the intervention using current interventional tools is limited.

Below-knee Bare Nitinol Stent Placement in High-risk Patients with Critical Limb Ischaemia and Unlimited Supragenicular Inflow as Treatment of Choice

Purpose: To evaluate the effectiveness of nitinol stent placement in long infrapopliteal lesions in patients with critical limb ischaemia. Materials and methods: Between January 2005 and January 2008, 34 high-risk patients (18 female; mean age: 73.8 ± 6.1 years) with critical limb ischaemia underwent infragenicular stenting. They had serious cardiovascular co-morbidities (>3, such as chronic obstructive pulmonary disease (COPD), congestive heart failure and coronary artery occlusive disease), American Society of Anaesthesiologists score of 3 or more, previous myocardial infarction, coronary stent or bypass. The mean stenosis length was 6.5 ± 0.9 cm (range: 2.2–8 cm), and the mean occlusion length was 7.5 ± 2.9 cm (range: 3–9.6 cm). Primary stent implantation was performed for long stenosis or occlusion based on the TransAtlantic InterSociety Consensus (TASC) C and D classification, secondary stenting for flow-limiting dissections or elastic recoil after balloon dilatation. All patients who returned to the outpatient clinic were assessed for claudication by clinical examination, ankle–brachial index (ABI) measurements, colour flow and duplex Doppler ultrasound (US). Digital subtraction angiography was performed if restenosis or re-occlusion was identified by Doppler US or transcutaneous measurement of partial oxygen pressure (TcpO2) measurements, when appropriate. Results: The technical success rate was 97.1% (33 of 34 cases). The crude rate of primary patency rate was 91.1% during a follow-up period of 10.4 ± 7.3 months. The mean ankle–brachial index increased significantly following intervention (0.45 ± 0.25–0.92 ± 0.13, p < 0.001). Two patients underwent successful redo angioplasty after tibioperoneal interventions due to in-stent restenosis (>70%) with relevant limitation of pain-free walking distance. In another patient, bypass surgery to the anterior tibial artery 6 months after primary intervention was necessary due to rest pain. Two patients required surgical revision of the femoral artery after antegrade access. No procedure-related death was recorded in the entire follow-up period. Conclusions: The mid-term outcome underscores infrapopliteal stent placement as a reliable treatment option in patients with critical limb ischaemia. In patients at high risk for crural bypass, with no flow-limiting supragenicular lesions, below-knee stent-supported angioplasty should be considered as a first choice of treatment.

Clinical outcomes after percutaneous peripheral intervention for chronic total occlusion of superficial femoral arteries: Comparison between self-expandable nitinol stent and stainless steel stent

It has been reported that nitinol stents provide higher patency in chronic phase than stainless steel stents after intervention to superficial femoral artery (SFA). However, there are few reports about stent patency for chronic total occlusion of SFA (SFA CTO). To compare clinical outcomes of self-expanding nitinol stents and stainless steel stents after percutaneous peripheral intervention (PPI) for SFA CTO. Between April 2004 and August 2007, a total of 25 SFA CTO lesions (nitinol stent group, 13; stainless steel stent group, 12) in 21 patients were treated with PPI, all patients were followed clinically, and 21 lesions (nitinol, 9; stainless steel, 12) received follow-up angiography. There was no significant difference in baseline characteristics, mean stent diameter (7.3+/-0.7 mm vs. 6.9+/-1.2 mm, p=0.32), pre-ankle-brachial index (ABI), and Fontaine stage between groups. Mean occlusion length and stent length were significantly longer (129.5+/-54.9 mm vs. 39.0+/-20.6 mm, 250.8+/-90.0 mm vs. 145.2+/-64.6 mm, respectively, p<0.01) and number of stents was significantly larger (2.8+/-0.9 vs. 1.6+/-0.5, p<0.01) in the nitinol stent group. At follow-up, ABI was significantly lower (0.73+/-0.20 vs. 0.95+/-0.13, p=0.04), restenosis rate and target lesion revascularization was significantly higher (58.3% vs. 15.4%, p=0.03; 50.0% vs. 7.7%, p=0.02, respectively) in the stainless steel stent group. Our study demonstrates the superiority of nitinol stent implantation compared with stainless steel stent implantation for SFA CTO.

Below-knee Bare Nitinol Stent Placement in High-risk Patients with Critical Limb Ischaemia and Unlimited Supragenicular Inflow as Treatment of Choice

To evaluate the effectiveness of nitinol stent placement in long infrapopliteal lesions in patients with critical limb ischaemia. Between January 2005 and January 2008, 34 high-risk patients (18 female; mean age: 73.8+/-6.1 years) with critical limb ischaemia underwent infragenicular stenting. They had serious cardiovascular co-morbidities (>3, such as chronic obstructive pulmonary disease (COPD), congestive heart failure and coronary artery occlusive disease), American Society of Anaesthesiologists score of 3 or more, previous myocardial infarction, coronary stent or bypass. The mean stenosis length was 6.5+/-0.9 cm (range: 2.2-8 cm), and the mean occlusion length was 7.5+/-2.9 cm (range: 3-9.6 cm). Primary stent implantation was performed for long stenosis or occlusion based on the TransAtlantic InterSociety Consensus (TASC) C and D classification, secondary stenting for flow-limiting dissections or elastic recoil after balloon dilatation. All patients who returned to the outpatient clinic were assessed for claudication by clinical examination, ankle-brachial index (ABI) measurements, colour flow and duplex Doppler ultrasound (US). Digital subtraction angiography was performed if restenosis or re-occlusion was identified by Doppler US or transcutaneous measurement of partial oxygen pressure (TcpO(2)) measurements, when appropriate. The technical success rate was 97.1% (33 of 34 cases). The crude rate of primary patency rate was 91.1% during a follow-up period of 10.4+/-7.3 months. The mean ankle-brachial index increased significantly following intervention (0.45+/-0.25-0.92+/-0.13, p<0.001). Two patients underwent successful redo angioplasty after tibioperoneal interventions due to in-stent restenosis (>70%) with relevant limitation of pain-free walking distance. In another patient, bypass surgery to the anterior tibial artery 6 months after primary intervention was necessary due to rest pain. Two patients required surgical revision of the femoral artery after antegrade access. No procedure-related death was recorded in the entire follow-up period. The mid-term outcome underscores infrapopliteal stent placement as a reliable treatment option in patients with critical limb ischaemia. In patients at high risk for crural bypass, with no flow-limiting supragenicular lesions, below-knee stent-supported angioplasty should be considered as a first choice of treatment.

The Results of a New Distal Protection Method in Intervention for Chronic Total Occlusion of the Superficial Femoral Artery

Aims. To determine the efficacy of a new distal protection method in SFA CTO interventions. Methods and Results. From June 2003 to February 2009, ninety-two consecutive, chronic total occlusions of superficial femoral arteries were treated with catheter-based intervention using a bidirectional approach. Nine of these cases were managed with our original, distal protection method, based on symptoms, angiographic images, wire resistance, and intravascular ultrasound images. The average age was 73 years; eight patients were male. The mean occlusion length was 17.1 cm. A distal protection balloon was inserted from the retrograde sheath in the popliteal artery and placed distal to the occluded lesion after successful wire crossing. Lesion dilatation with a balloon was performed antegradely and debris was removed by 6Fr. guiding catheter. Debris was retrieved from all lesions, consisting mainly of thrombus. Where we decided not to use the distal protection method, there was no distal thromboembolism. Conclusion. In SFA-CTO intervention, the risk of distal embolization is 10%, which can be anticipated and eliminated by the distal protection method.

Behandlung akuter Okklusionen von femoropoplitealen Bypässen: Vergleich der mechanischen Rotationsthrombektomie mit der ultraschallgestützten Lyse

Mechanical thrombectomy has become a viable alternative to intra-arterial thrombolysis for the treatment of acute infrainguinal occlusion. The aim of this prospective study was to evaluate the safety and effectiveness of a mechanical thrombectomy system in comparison with ultrasound-enhanced thrombolysis. From April 2005 to March 2007, 20 patients, mean age 67.4+/-13.6, with acute occlusions of the femoropopliteal bypass graft were treated with either a rotational thrombectomy system (Straub Rotarex, n=10) or with 1.0 mg/h Actilyse using an ultrasound-enhanced lysis system (EKOS Lysus Peripheral Catheter System, n=10). The mean occlusion length was 33.1 cm (range 28-40 cm) in the thrombectomy group and 33.7 cm (11-50 cm) in the lysis group. The technical success rate was 100% in the thrombectomy group and 90 % in the lysis group. The mean treatment time was significantly lower with 64.5 min (45-90 min) in the thrombectomy group in comparison with 904.0 min (120-1350 min) in the lysis group. The ankle brachial index (ABI) improved in the thrombectomy group from 0.41+/-0.09 to 0.86+/-0.10 at discharge and 0.85+/-0.07 after 1 month (p<0.05) and in the lysis group from preinterventional 0.37+/-0.15 to 0.82+/-0.16 at discharge and 0.80+/-0.24 after 1 month (p<0.05). In one case lysis had to be stopped after two hours because of dislocation of the introducer sheath which was then treated by open surgery. Mechanical-rotational thrombectomy with the Rotarex system and lysis with the ultrasound-enhanced catheter from Ekos were very safe and effective treatment options for acute occlusion. Blood flow is restored much faster with mechanical thrombectomy.

Mechanische Rotationsthrombektomie zur Behandlung von akuten und subakuten Okklusionen der femoropoplitealen Arterien: Retrospektive Auswertung der Ergebnisse von 1999 bis 2005

Direct intra-arterial thrombolysis is the standard of care over acute surgical intervention for acute infrainguinal occlusion. However, several mechanical thrombectomy devices can be utilized as a less invasive alternative to rapid reperfusion of the acutely threatened limb. Retrospective analysis of 265 patients treated from 1999 to 2005, mean age 65+/-8.4 (range from 47 to 75) years, with acute (85 patients, 32.1 %, group 1) or subacute (180 patients, 67.9 %, group 2) occlusions of the femoropopliteal artery with a rotational thromboembolectomy system (Straub Rotarex). The mean occlusion length was 25 (range 2 - 40) cm. The technical success rate was 94.7 % (251 / 265). In the additional 14 patients, no complete clot removal (n = 9) or intraluminal guidewire passage was able to be achieved (n = 5). After a mean follow-up of 12 +/-3 months, the restenosis rate was 49 % in group 1 and 54 % in group 2. The ankle-brachial index improved in group 1 from 0.32 +/- 0.17 to 0.78+/- 0.24 at discharge and 0.71 +/- 0.23 after 12 months (p < or =0.001) and in group 2 from preinterventional 0.47+/- 0.24 to 0.81 +/- 0.19 at discharge and 0.74 +/- 0.24 after 12 months (p < or = 0.001). There were 16 (6 %) distal embolizations and 3 (1.2 %) perforations. There were no cases of amputation or death during follow-up. The mechanical rotational thrombectomy is a very safe and effective alternative to local lysis. The only limitation is that there is no treatment possible in the infrapopliteal artery.

Comparison of 1% and 3% Polidocanol Foam in Ultrasound Guided Sclerotherapy of the Great Saphenous Vein: A Randomised, Double-Blind Trial with 2 Year-Follow-up. “The 3/1 Study”

Objectives: To compare 1% and 3% POL foam in treating the great saphenous vein (GSV) by ultrasound guided sclerotherapy. Design: Multicentre, prospective, randomised, double-blind trial with 2 year-follow-up. Patients and methods: 148 patients with GSV reflux (saphenous trunk diameter 4–8 mm) were randomised to undergo ultrasound guided foam sclerotherapy using either 1% or 3% POL foam in a single session. Foam production was standardised using a sterile disposable syringe kit including sterile air and the Turbofoam® machine. Duplex ultrasonography was used to assess the outcome at 3 weeks, 6 months, 1 year, 18 months and 2 years. The main criterion of success was the disappearance of the venous reflux. The length of occlusion of the vein (only measured at 3 week-echography assessment) was a secondary criterion. Side effects were assessed. Results: 74 patients were included in each group. The mean volume of foam injected was 4.4 ml for the 3% group and 4.6 ml for the 1% group. After 3 weeks, reflux was abolished in 96% (71 patients) of the 3% group and 88% (68 patients) of the 1% group (NS). The mean occlusion length of the vein was 38 cm for the 3% group and 34 for the 1% group (NS). After 2-years, reflux was absent in 69% of the 3% group and 68% of the 1% group (NS). 14 patients were lost to follow-up at 2 years. Conclusion: This study demonstrates equivalent efficacy for 1% POL and 3% POL foam in sclerotherapy of the GSV where the trunk is less than 8 mm in diameter. These data obtained two years of follow-up confirm our previously reported 6 month-follow-up data published in 2005.

Comparison of 1% and 3% Polidocanol Foam in Ultrasound Guided Sclerotherapy of the Great Saphenous Vein: A Randomised, Double-Blind Trial with 2 Year-Follow-up. “The 3/1 Study”

To compare 1% and 3% POL foam in treating the great saphenous vein (GSV) by ultrasound guided sclerotherapy. Multicentre, prospective, randomised, double-blind trial with 2 year-follow-up. 148 patients with GSV reflux (saphenous trunk diameter 4-8 mm) were randomised to undergo ultrasound guided foam sclerotherapy using either 1% or 3% POL foam in a single session. Foam production was standardised using a sterile disposable syringe kit including sterile air and the Turbofoam machine. Duplex ultrasonography was used to assess the outcome at 3 weeks, 6 months, 1 year, 18 months and 2 years. The main criterion of success was the disappearance of the venous reflux. The length of occlusion of the vein (only measured at 3 week-echography assessment) was a secondary criterion. Side effects were assessed. 74 patients were included in each group. The mean volume of foam injected was 4.4 ml for the 3% group and 4.6 ml for the 1% group. After 3 weeks, reflux was abolished in 96% (71 patients) of the 3% group and 88% (68 patients) of the 1% group (NS). The mean occlusion length of the vein was 38 cm for the 3% group and 34 for the 1% group (NS). After 2-years, reflux was absent in 69% of the 3% group and 68% of the 1% group (NS). 14 patients were lost to follow-up at 2 years. This study demonstrates equivalent efficacy for 1% POL and 3% POL foam in sclerotherapy of the GSV where the trunk is less than 8 mm in diameter. These data obtained two years of follow-up confirm our previously reported 6 month-follow-up data published in 2005.

Rheolytic thrombectomy, angioplasty, and selective stenting for subacute isolated popliteal artery occlusions

We have observed that some patients with isolated popliteal artery occlusions (PAOs) harbor varying degrees of organized clot, as suggested by the rapidity with which these occlusions are traversed with the Glidewire. We hypothesized that debulking such PAOs by using rheolytic thrombectomy without adjunctive thrombolysis before percutaneous transluminal angioplasty and selective stenting (PTA/S) is safe and enables single-session treatment with minimal risk of embolization. Between February 2004 and January 2007, 16 male patients (mean age, 68.9 +/- 11.1 years; range, 54-84 years) presenting with disabling claudication (n = 1), rest pain (n = 5), and tissue loss (n = 10; mean duration, 11 +/- 8 weeks; range, 4-26 weeks) were prospectively followed up after rheolytic thrombectomy and angioplasty and selective stenting of their PAO. The mean occlusion length was 11.6 +/- 4.5 cm. After rheolytic thrombectomy, the occlusions were converted to long stenoses (mean length of 7.6 +/- 3.6 cm). Self-expanding stents were used in 10 of 16 (mean length of 8.3 +/- 4.4 cm). Additional recanalizations of occlusions of the iliac artery and proximal superficial femoral artery were performed before popliteal artery recanalizations in two patients. Ankle-brachial indexes increased from 0.27 +/- 0.22 to 0.94 +/- 0.13. No case of distal embolization was observed. Adjuvant thrombolysis was used in only one case to improve runoff. Inline flow to the foot was achieved in 15 of 16 cases. Three occlusions occurred at 3, 6, and 20 months after surgery (mean follow-up, 15.7 +/- 10.0 months), and two patients underwent successful thrombolysis. The third patient refused further intervention and remains a claudicant. One-year primary and secondary patency rates were 84% and 92%, respectively. Two limb losses occurred at 7 and 9 months as a result of recurrent foot infection in patients with diabetes, both with patent popliteal arteries (1-year limb salvage rate, 83%). We advocate debulking isolated subacute PAOs with rheolytic thrombectomy when they are easily crossed, because this enables recanalization of these lesions in a single setting, thus obviating the additional need for thrombolysis in most cases, with seemingly minimal risk of distal embolization. This simple approach is effective and widely available.

Treatment of Critical Limb Ischemia Using Ultrasound-Enhanced Thrombolysis (PARES Trial): Final Results

To evaluate the safety and performance of ultrasound-enhanced thrombolysis in the treatment of acute thrombotic or embolic occlusion of the lower limb arteries. From April 2005 to July 2006, 25 patients (15 men; mean age 64.1 years, range 37-82) presenting with acute (<14 days old) occlusions of the lower limb arteries were treated with local thrombolysis [recombinant tissue plasminogen activator (rtPA)] in a dosage of 1.0 mg/h using the EKOS Lysus Peripheral Catheter System with an ultrasound core. No bolus injection of rtPA was given. The mean occlusion length was 25.1 cm (range 2-70). The technical success rate was 100%. Total clot removal was achieved in 22 (88%) patients after 16.9 hours (range 5-24) using a mean 17 mg (range 5-25) of rtPA. In 8 cases, total clot removal of the main lesion was achieved after 6 hours (6 mg of rtPA). In 1 patient, lysis was stopped after 2.5 hours because of bleeding due a dislocation of the introducer sheath. In 2 cases, total clot removal could not be achieved; these patients were successfully treated with thromboaspiration. At the 1-month follow-up, the treated vessel was still patent in 20 patients. Two reocclusions occurred; 1 was treated with a bypass graft and the other with conservative therapy. There were no cases of amputation or death during follow-up. There were no side effects related to rtPA or the catheter system. This study demonstrates that local lysis of acute arterial occlusions using the Lysus Peripheral Catheter System is safe and effective. Blood flow is restored quickly.

Improved Technical Success and Midterm Patency with Subintimal Angioplasty Compared to Intraluminal Angioplasty in Long Femoropopliteal Occlusions

To compare the efficacy of subintimal angioplasty combined with primary stenting to intraluminal angioplasty with stenting for revascularization of long (>10 cm) femoropopliteal arterial occlusions. Baseline characteristics and outcomes of 52 patients (40 men; mean age 65.6+/-9.7 years) with superficial femoral artery (SFA) occlusions in 61 limbs (mean occlusion length 22.7+/-9.9 cm) treated with subintimal angioplasty and primary stenting were compared with a 54-patient control group (46 men; mean age 64.8+/-8.2 years) from our registry database who had intraluminal angioplasty with stenting in 60 limbs (mean occlusion length 22.0+/-8.5 cm). All baseline clinical and angiographic characteristics showed no differences. In all patients, at least 1 self-expanding nitinol stent was implanted. Subintimal angioplasty was successful in 58 (95.1%) of 61 limbs, whereas technical success for the conventional approach was 86.7% (52/60 limbs; p = 0.11). In both groups, there were no major complications requiring surgery. Primary patency at 12 months for successful cases was 76.4% for subintimal angioplasty and 59.2% for conventional angioplasty (p = 0.06); on an intention-to-treat basis, including technical failures, the rates were 72.4% and 50.9%, respectively (p = 0.02). Subintimal angioplasty combined with stenting was feasible, with a high technical success rate and better short and midterm results for revascularization of long femoropopliteal occlusions than the conventional intraluminal approach.

Laser Atherectomy for Lower Extremity Revascularization: An Adjunctive Endovascular Treatment Option

Excimer laser atherectomy (LA) employs precision laser energy control (shallow tissue penetration) and safer wavelengths (ultraviolet as opposed to the infrared spectra in older laser technology), which decreases perforation and thermal injury to the treated vessels. Though extensively used by cardiologists for severe obstructive coronary artery disease, peripheral interventionalists have not accepted LA as a routine adjunctive technique for stenotic or occluded vessels. We report herein the technical and clinical outcomes with LA for complex peripheral vascular disease in patients deemed high-risk for conventional surgical revascularization. Over a 6-month period, 19 lesions in 15 high-risk patients (mean age 72 +/-10 years) were treated with LA (308-nm spectral wavelength) followed by balloon angioplasty for limb-threatening ischemia (n = 10) and severe disabling claudication (n = 5). The lesions were located at the superficial femoral artery (n = 8), popliteal artery (6), and/or tibial vessels (5). The mean occlusion length was 10.3 +/-2.3 cm. Laser catheter choice ranged from 1.4 to 2.5 mm depending on the target vessel diameter. Clinical examination, duplex ultrasound, and ankle-brachial indices were performed in follow-up visits. Immediate technical success was achieved in 16 (84%) lesions. In the 3 technical failures, inability to cross the lesion with a wire (n = 2) or vessel perforation (n = 1) precluded successful LA. Overall, primary patency as assessed by duplex was 57% (superficial femoral artery 71%, popliteal 60%, tibial vessels 25%). Clinical improvement was seen in 10 lesions (77%) that were successfully treated initially. One patient required below-knee amputation. At an average of 2-year follow-up, 6 patients who were initially successfully treated were alive (46%), including 3 patients (50%) with stable symptoms without the need for major amputation. Laser atherectomy is a useful adjunctive revascularization technique for high-risk patients with limb-threatening ischemia. This technique is especially beneficial in the treatment of ostial lesions, which may be prone to distal embolization, as well as total occlusions that can be traversed by a guide wire but not a balloon. Vascular surgeons should add LA to their endovascular armamentarium for the treatment of complex peripheral vascular disease in the high surgical risk patients. Further study of clinical outcome measures and comparison to other interventional techniques are warranted.

Endovascular Recanalization of Chronic Long-Segment Occlusions of the Inferior Vena Cava:Midterm Results

To report the midterm results of endovascular recanalization of chronic long-segment (> 5 cm) occlusions of the inferior vena cava (IVC) with stent placement. Nine patients (5 men; median age 30 years, range 14-58) with disabling complaints for more than 6 months caused by IVC occlusions were treated by endovascular recanalization. Mean occlusion length was 11 cm (range 6-22); some occlusions extended to the iliac (n = 3) or common femoral (n = 2) veins. All procedures were performed under local anesthesia via a bilateral femoral (n = 7) or popliteal (n = 2) approach. In 3 patients, combined access to the brachial or internal jugular vein was necessary. Patients with acute-on-chronic thrombosis were pretreated with urokinase. After guidewire recanalization, the chronic occlusions were predilated and self-expanding Wallstents were implanted. The initial technical and clinical success was 100%. The venous clinical severity score (pain, venous edema, inflammation, and active ulceration) decreased from a mean 8 +/- 2 to 5 +/- 1 after the procedure. Over a median follow-up of 9 months (mean 21, range 4- 110), 3 patients died. One rethrombosis occurred, and an asymptomatic restenosis was discovered on routine imaging. The primary patency rate was 78%, and the 9-month occlusion-free survival rate was 56%. Endovascular recanalization of chronic long-segment occlusions of the IVC is a safe and worthwhile technique to offer patients with debilitating symptoms.

Technical Report and Preliminary Clinical Data of a Novel Catheter for Luminal Re-Entry After Subintimal Dissection

The objective of this study was to evaluate the safety and the effectiveness of the Outback catheter for intraluminal re-entry after subintimal dissection in the crossing of chronic arterial occlusions. This study was a proof-of-concept feasibility. Ten patients with totally occluded arteries in the iliac artery to the distal femoral artery (mean occlusion length, 13.1 cm; range, 5-25 cm) were treated with the novel catheter. After successful re-entry, PTA or PTA plus stenting was performed. No perforations, dissections, lacerations, or device complications occurred. The procedural re-entry success rate with the Outback catheter was 50% (5/10 patients). Although the Outback catheter is safe, the percentage of intraluminal reaccess should be ameliorated through engineering improvements because there is some evidence to suggest that subintimal recanalization could produce improved long-term results.

Initial clinical experience with an IVUS-guided transmembrane puncture device to facilitate recanalization of total femoral artery occlusions.

Failure to recanalize chronic superficial femoral artery occlusions is frequently caused by subintimal passage of the occlusion with inability to re-enter the true lumen with the guide-wire. The present study details our initial experience with the Pioneer crossing device (Medtronic, Menlo Park, CA) to facilitate recanalization of total femoral artery occlusions. 25 consecutive patients (18 male, mean age 63 years) whose failed recanalization attempts of chronic superficial femoral artery occlusions (mean occlusion length 12.7 cm) with standard techniques were re-scheduled for a secondary recanalization procedure. The Pioneer crossing device is a 6.2F rapid exchange catheter, which tracks over a 0.014"-wire. A 20MHz phased array IVUS transducer is integrated into the tip of the catheter allowing visualization of the vessel morphology. Using the guidance of the IVUS cross-sectional image supported by colour-flow imaging, the true lumen is punctured with an integrated 24G needle allowing delivery of a second 0.014"-wire. Re-entry into the true lumen was successfully accomplished in all cases without complications. In 8 cases with severe calcification predilatation of the false channel was necessary to allow advancement of the Pioneer crossing device. Furthermore, in 7 patients with severe calcification multiple puncture attempts were necessary to penetrate the dissection membrane. A procedural success (<25% residual stenosis) could be achieved in all cases after predilatation and stenting of the occlusion with self-expanding nitinol stents. The Pioneer crossing device is an effective and save tool to facilitate true lumen re-entry during recanalization of total superficial femoral artery occlusions.

Percutaneous revascularization of long-standing chronic occlusion of the superficial femoral artery. A pilot study

The treatment of long chronic occlusion of peripheral arteries remains unsatisfactory. In particular occlusions of the superficial femoral artery (SFA) are not considered suitable for percutaneous interventions. It was the aim of our study to evaluate this technique, the initial technical success and the follow-up patency rates after percutaneous revascularization of long chronic occlusion of the the SFA. 58 consecutive patients (mean age 64.8 +/- 9.7/40-80 years, 40 men/69.0%) were included. Of these patients 15 had bilateral SFA-occlusions and 14 showed additional disease in the popliteal artery. The mean occlusion length was 21.9 +/- 14.8 cm. At baseline absolute treadmill walking distance was 125 +/- 61 m. in all cases a balloon angioplasty was performed, additional excimer laser in 80.8% and stenting in 50.9%. A primary technical success was achieved in 89.0%. According to the American Heart Association guidelines a markedly clinical improvement was shown: +3 in 16.2%, +2 in 74.4%, +1 in 9.3% of the patients. The 12-months cumulative primary patency rate was 43.6%, primary assisted patency and secondary patency rate was 85.5% and 69.1% respectively. Long chronic occlusion can be successfully treated by percutaneous techniques. To maintain a high patency rate frequent clinical follow-up is mandatory.

Angioplasty and Stent Placement in Chronic Occlusion of the Superficial Femoral Artery: Technique and Results

To improve the patency rate for angioplasty in chronic occlusion of the superficial femoral artery by deploying stents after angioplasty. Angioplasty and stent placement were performed in 61 arteries in 48 male patients. The mean occlusion length was 13.5 cm and the mean stent length was 30 cm. Patency rates were analyzed at 6 months and at 1, 2, 3, and 4 years. The predictors of restenosis were analyzed by univariate and multiple logistic regression. Patency rates were 87% at 6 months, consisting of 74% primary, 6% primary assisted, and 7% secondary; 79% at 1 year, consisting of 47% primary, 19% primary assisted, and 13% secondary; 72% at 2 years, consisting of 36% primary, 26% primary assisted, and 10% secondary; 70% at 3 years, consisting of 26% primary, 22% primary assisted, and 22% secondary; and 63% at 4 years, consisting of 25% primary, 0% primary assisted, and 38% secondary. There was a 15% morbidity rate and one mortality as a result of retroperitoneal bleeding. Better patency rates were noted at all time intervals in diabetic limbs, 7-mm-diameter versus 10-mm-diameter stents, shorter obstructions and shorter stents, nonsmokers, in limbs in which urokinase was not necessary after stent deployment, and in limbs with an International Society of Cardiovascular Surgery (ISCVS) classification under 3. Patency rates were not affected by age, race, number of trifurcation vessels patent, experience in performing the procedures, and procedures requiring less time. By multivariate logistic analysis, the independent predictors of patency at 6 months were postprocedure ankle/brachial index (ABI) and shorter stent length; at 1 year, preprocedure ABI, shorter stent length, and the presence of diabetes; at 2 years, preprocedure ABI and the presence of diabetes; and at 3 years, the preprocedure ABI. The techniques used to reestablish antegrade flow in these superficial femoral arteries yielded a high success rate. In addition, the use of angioplasty with stents may improve patency rates over angioplasty without stents.

Initial experience with a hydrophilic-coated guidewire for recanalization of chronic coronary occlusions.

Chronic coronary occlusions are still a therapeutic challenge to the interventional cardiologist. New techniques such as laser wire have improved recanalization rates, but outcomes are still far from satisfactory. We report the results of a nonrandomized single-center investigation using a hydrophilic-coated guidewire (Terumo Crosswire). Between September 1996 and September 1998, 107 chronic occlusions in 106 patients were approached when previous attempts with conventional guidewires failed. Median occlusion duration in these cases was 4 months (range, 0.5-122); mean occlusion length was 19 +/- 11 mm (range, 5-60). Forty-five (42%) of these attempts were successful. Attempts were successful in 42% in the left anterior descending artery, in 30% in the left circumflex artery, in 48% in the right coronary artery, and in 43% in coronary artery bypass grafts. Success rates ranged from 56% for occlusions of less than 4-month duration to 18% for occlusions of more than 36-month duration. The success rate in TIMI 1-flow lesions was significantly higher than in TIMI 0 flow lesions, 85% vs. 36%. In a multivariate regression analysis, TIMI flow grade and occlusion age were independent predictors of success. There were no deaths or Q-wave myocardial infarctions; two cases of hemopericardium were treated successfully. In five cases, pericardial contrast staining due to vessel perforation occurred. Our results indicate that the Crosswire is an effective tool in the treatment of chronic coronary occlusions, even when recanalization attempts with conventional guidewires fail. Cathet. Cardiovasc. Intervent. 49:45-50, 2000.

Short-Term Results and Intermediate-Term Follow-Up of Laser Wire Recanalization of Chronic Coronary Artery Occlusions: A Single-Center Experience

Objectives. This study sought to elucidate the short-term efficacy and intermediate-term outcome of excimer laser recanalization of chronic coronary artery occlusions in patients in whom attempts at mechanical revascularization had failed.Background. Recanalization of chronic coronary occlusions with the use of a mechanical guide wire fails in 30% to 50% of cases, mostly because of inability to pass the wire through the lesion. The value of using excimer laser energy in this setting has not yet been determined.Methods. The study group comprised 66 consecutive patients with 68 chronic coronary occlusions. Patients were eligible for inclusion in the study if a previous attempt at mechanical revascularization had failed and if their angiographic status was such that 1) the vessel segment distal to the occlusion could be visualized by way of collateral vessels, 2) the entry point of the occlusion was clearly outlined, and 3) not more than one anatomic bend was expected within the occlusion. Excimer laser energy was applied to the lesion through a 0.018-in. (0.046 cm) fiber-optic guide wire. Adjunctive balloon angioplasty and stenting were performed in all successfully treated patients but one.Results. Thirty-four occlusions (50%) in 32 patients (48%) could be crossed with the laser wire. Location and age of the occlusion had no adverse influence on the outcome of laser wire recanalization, nor did the presence of bridging collateral vessels, a major side branch at the site of the lesion or a blunt stump of the occlusion. An inverse relation was found between the success rate and the length of the occlusion, such that a 19% reduction of the success rate accompanied each 10-mm increment of the mean occlusion length. Thus, the success rate was 68% for lesions ≤10 mm but only 25% for lesions >30 to ≤40 mm. The presence of a bend in the lesion exceeding 60° was strongly related to procedural failure. During a median angiographic follow-up period of 18 weeks, restenosis >50% (n = 6) or reocclusion (n = 4) was found in 10 of the 32 successfully treated patients, for an intermediate-term success rate of 33% (22 of 66). Clinical follow-up revealed improved anginal status in 21 patients (66%) after a median of 24 weeks. Major complications (death, myocardial infarction, emergency operation) were not encountered.Conclusions. Successful recanalization of a chronic coronary occlusion by using currently available laser wires can be expected in 50% of selected patients in whom attempts at mechanical revascularization fail. Restenosis or reocclusion accounts for an overall 6-month success rate of 35%.