Future Of RF Ablation: Continuous Or Segmental? Alan M Dietzek, MD, RVT, RPVI, FACS Alan M Dietzek, MD, RVT, RPVI, FACS Clinical Associate Professor of Surgery Clinical Associate Professor of Surgery University of Vermont College of Medicine University of Vermont College of Medicine Chief, Section of Vascular and Endovascular Surgery Chief, Section of Vascular and Endovascular Surgery Linda and Stephen R Cohen Chair in Vascular Surgery Linda and Stephen R Cohen Chair in Vascular Surgery Danbury Hospital- Western CT Health Network Danbury Hospital- Western CT Health Network 12 th International Varicose Vein Congress: In-Office Techniques Lowes Hotel Miami Beach, Fla. April 24-26, 2014
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Future Of RF Ablation: Continuous Or Segmental?
Alan M Dietzek, MD, RVT, RPVI, FACSAlan M Dietzek, MD, RVT, RPVI, FACSClinical Associate Professor of SurgeryClinical Associate Professor of Surgery
University of Vermont College of MedicineUniversity of Vermont College of MedicineChief, Section of Vascular and Endovascular SurgeryChief, Section of Vascular and Endovascular Surgery
Linda and Stephen R Cohen Chair in Vascular SurgeryLinda and Stephen R Cohen Chair in Vascular SurgeryDanbury Hospital- Western CT Health NetworkDanbury Hospital- Western CT Health Network
12th International Varicose Vein Congress:In-Office Techniques
Lowes Hotel Miami Beach, Fla.April 24-26, 2014
Research Grant - CovidienResearch Grant - Covidien
At The StartContinuous RF Bipolar Ablation (VNUS Medical)
Next Generation VNUS RF Continuous Bipolar RF Closure and ClosurePlus•Electrodes transfer RF energy (= electromagnetic energy with freq range 300kHz – 1MHz) by direct contact with vein wall
– EM waves vibrate atoms in vein wall releasing thermal energy heats vein wall to 850C (Resistive Heating)
•Continuous catheter pullback during treatment
•Two catheter sizes • 6F and 8F
Bipolar Continuous Pullback Technology
0.0250.025”” lumen lumen
Continuous RF Bipolar Technology Limitations
Operator Dependent • Treatment variability 20 to inadequate energy transfer:
• Withdraw catheter too quickly (>2-3cm/min)• speed - energy delivery
• Too little tumescence - • Poor vein wall compression -
• Poor electrode contact with wall
• Poor result with large (>12mm) veins
•
• Small Treatment Area• Only small area of vein is treated at any
RF Energy heats Catheter tip (7cm heating element) to 120° C
Conductive Heat Transfer (electromagnetic radiation) from heating element to vein wall achieves temperatures of 100-110°C Vein wall heating only when catheter is stationary
Direct contact with vein wall not necessary
Segmental Ablation Tecnology- CLFAdvantages vs Bipolar
Not operator dependentNo impedance monitoring
- No generator shut-offsOne size catheter fits all vein diameters but not all lengths
Large treatment area:- 6.5cm segment of vein in 20s
Olympus Celon RFiTT ProcedureOlympus Celon RFiTT ProcedureDeveloped in 2007 as alternative Developed in 2007 as alternative to VNUS bipolar RFto VNUS bipolar RFUses Bipolar technologyUses Bipolar technology
Resistive heatingResistive heating of the vein wall of the vein wall 20 J/cm vs 60-80 J/cm with CLF20 J/cm vs 60-80 J/cm with CLF
• Power is adjustable
953 patients (1172 GSV/228 SSV)953 patients (1172 GSV/228 SSV) 462 patients completed study (569 GSV and 103 SSV)462 patients completed study (569 GSV and 103 SSV) Prospective; multicenter - EuropeanProspective; multicenter - European f/u between 180 and 360 days (mean 290 f/u between 180 and 360 days (mean 290 ++ 84d) 84d) Mean vein treatment length – 50 cm Mean vein treatment length – 50 cm ++ 20cm 20cm All patients treated with bipolar Celon lab RFITT systemAll patients treated with bipolar Celon lab RFITT system Mean treatment time: 89sec Mean treatment time: 89sec ++ 66 (1.8cm/sec) 66 (1.8cm/sec)
Phlebology 2013;28: 38-46
ResultsResultsOcclusion rate at mean f/u 290 days - 92%; partial Occlusion rate at mean f/u 290 days - 92%; partial occlusion 4%; failure 3%occlusion 4%; failure 3%
Occlusion rate 98.4% with Occlusion rate 98.4% with lower power 18-20 Wlower power 18-20 W Catheter withdrawal rate >1.5s/cm (no failures >2.5s/cm)Catheter withdrawal rate >1.5s/cm (no failures >2.5s/cm) Experienced (>20 cases) operatorExperienced (>20 cases) operator
Pain scores (visual analog scale)Pain scores (visual analog scale) 2/10 at day 1; 1 after 7d; 0 on all subsequent visits2/10 at day 1; 1 after 7d; 0 on all subsequent visits
Complications - Sensory disturbance 5.8%Complications - Sensory disturbance 5.8%Tumescence not used in 27% of limbsTumescence not used in 27% of limbs
EVRF Early and Midterm ResultsSzabo A and Danciu P: Vein Therapy News Feb/March 2013
150 limbs in 150 pts150 limbs in 150 pts Single center, Prospective?Single center, Prospective? Output power – 25W; 4 beeps/0.5cm?Output power – 25W; 4 beeps/0.5cm? f/u at 1d, 1wk, 1 to 2 monthsf/u at 1d, 1wk, 1 to 2 months 129 GSV, 15 SSV and 6 GSV + SSV129 GSV, 15 SSV and 6 GSV + SSV High ligation in 6 limbs with SFJ > 20mmHigh ligation in 6 limbs with SFJ > 20mm Concomitant phlebectomy in all casesConcomitant phlebectomy in all cases
ResultsResults Complete occlusion in 99% (149/150) at 1moComplete occlusion in 99% (149/150) at 1mo Postop pain score (VAS) - 2/10 (when?)Postop pain score (VAS) - 2/10 (when?)
VNUS Closure Plus – bipolar technology Vein Occlusion Rates – single center results
1. Weiss RA, Weiss MA. Controlled radiofrequency endovenous occlusion using a unique radiofrequency catheter under duplex guidance to eliminate saphenous varicose vein reflux: a 2-year follow-up. Dermatol Surg. 2002;28:38-42.
2. Kistner RL. Endovascular obliteration of the greater saphenous vein: The Closure procedure. Jpn J Phlebol 2002;13: 325-33.
3. Whiteley MS, Holdstock J, Price B, Gallagher T, Scott M. Radiofrequency ablation of refluxing superficial and perforating veins using VNUS Closure and TRLOP technique. Abstract presented at the XVII Annual meeting of the European Society for Vascular Surgery, Dublin, Ireland, Sept. 6-8, 2003.
Future Of RFA: Continuous Or Segmental? Summary New Continuous RF caths are smaller and more New Continuous RF caths are smaller and more
flexible than present Segmental cathsflexible than present Segmental caths Continuous RF still operator dependent, but with Continuous RF still operator dependent, but with
faster pullback times – may lead to less variable faster pullback times – may lead to less variable resultsresults
Published data for alternative RF devices is sparse, Published data for alternative RF devices is sparse, short term and of poor quality short term and of poor quality
Segmental ablation is still the Segmental ablation is still the Gold StandardGold Standard for for endovenous ablation but new Continous RF endovenous ablation but new Continous RF technologies show promisetechnologies show promise
Catheter cost may dictate the future Catheter cost may dictate the future
Go Knicks!
2013
Thank You
2014
Go Brooklyn
First Generation RFA Device Results: How Good Was It?
Substantial Body of Clinical Evidence Over 60 publications
Mechanism of action and pathophysiological
outcomes well understood
4 randomized trials comparing RFA with vein stripping
with 1222 limbs/1005 pts treated proven the durability
of the treatment with 5-year follow-up data
Multiple independent reports validated the results of
major trials
First Generation RFA DeviceAll Randomized Trials: RFA vs. Stripping
1. Rautio T, Ohinmaa A, Perala J, Ohtonen P, Heikkinen T, Wiik H, Karjalainen P, Haukipuro K, Juvonen T. Endovenous obliteration versus conventional stripping operation in the treatment of primary varicose veins: a randomized controlled trial with comparison of the costs. J Vasc Surg. 2002; 35: 958-65.
2. Lurie F, Creton D, Eklof B, Kabnick LS, Kistner RL, Pichot O, Schuller-Petrovic S, Sessa C. Prospective randomized study of endovenous radiofrequency obliteration (closure procedure) versus ligation and stripping in a selected patient population (EVOLVeS Study). J Vasc Surg. 2003; 38: 207-14.
3. Lurie F, Creton D, Eklof B, Kabnick LS, Kistner RL, Pichot O, Sessa C, Schuller-Petrovic S. Prospective Randomised Study of Endovenous Radiofrequency Obliteration (Closure) Versus Ligation and Vein Stripping (EVOLVeS): Two-year Follow-up. Eur J Vasc Endovasc Surg. 2005;29:67-73.
4. Stoetter L, Schaaf I, Bockelbrink A. Invaginating stripping, kryostripping or endoluminal radiofrequency obliteration to treat GSV insufficiency: duplex ultrasound findings and clinical outcome postoperatively and at 1-year follow up. 17th annual meeting of American Venous Forum. San Diego, Feb, 2005
5. Hinchliffe RJ, Ubhi J, Beech A, Ellison J, Braithwaite BD. A Prospective Randomised Controlled Trial of VNUS Closure versus Surgery for the Treatment of Recurrent Long Saphenous Varicose Veins. Eur J Vasc Endovasc Surg. 2005 Aug 30; [Epub ahead of print]
Summary Summary RFA patients - significantly less pain and RFA patients - significantly less pain and post-op morbidity, faster recovery and better post-op morbidity, faster recovery and better quality of life than stripping patientsquality of life than stripping patients
First Generation RFA DeviceVNUS Clinical Registry – ResultsMulticenter (>30 centers);1006 patients and 1222 limbs treated
1. Merchant RF, et al. Long-term outcomes of endovenous radiofrequency obliteration of saphenous reflux as a treatment for superficial venous insufficiency. J Vasc Surg 2005, 42(3): 502-509
1 Yr 2 Yrs 3 Yrs 4 Yrs 5 Yrs
Absence of reflux417/473
88%
232/263
88%
117/133
88%
103/119
87%
98/117
84%
First Generation RFA DeviceVNUS Clinical Registry - Results
1. Merchant RF, et al. Long-term outcomes of endovenous radiofrequency obliteration of saphenous reflux as a treatment for superficial venous insufficiency. J Vasc Surg 2005, 42(3): 502-509
1 Yr 2 Yrs 3 Yrs 4 Yrs 5 Yrs
Absence of reflux417/473
88%
232/263
88%
117/133
88%
103/119
87%
98/117
84%
First Generation RFA DeviceVNUS Clinical Registry - Results
1. Merchant RF, et al. Long-term outcomes of endovenous radiofrequency obliteration of saphenous reflux as a treatment for superficial venous insufficiency. J Vasc Surg 2005, 42(3): 502-509
1 Yr 2 Yrs 3 Yrs 4 Yrs 5 Yrs
Absence of reflux417/473
88%
232/263
88%
117/133
88%
103/119
87%
98/117
84%
Vein occlusion( 3 cm patent stump)
412/473412/473
87%87%
232/263
88%
111/133
84%
101/119
85%
102/117102/117
87%87%
New Generation RFA Device ClosureFAST Study
Multicenter (13 Study Centers in Europe and the US) 326 patients; 396 limbs treated Percent Female = 73.3% Average Age = 47.2 ± 12.4 years Average Height = 170.0 cm ± 8.4 cm Average Weight = 74.2 kg ± 16.9 kg All veins treated were GSV from groin to knee Average vein diameter at 3 cm from SFJ 5.5 ± 2.1 mm (2.0 - 18.0mm ) Average length of veins treated: 36.9 ± 10.6 cm Average energy delivery time: 2.2 ± 0.6 min Average procedure time (cath in to cath out): 15.2 ± 7.5m
CLF Occlusion Rate at 3 Years - 92.9%Kaplan Meier Analysis
•0 •5 •10 •15 •20 •25
•100
•99
•98
•97
•96
•95
•94
•93
•92
Time (months)
Occlusion Rate (%)
1 month
99.7%
n=337 6 Months
98.5%
n=317
1 Year
96.4%
n=286 2 Year
94.7%
n=286
•30 •35 •40
3 Year
92.9%
n=255
ClosurePlus 3 year Occlusion Rate - 84% 1 1. Merchant RF, et al. J Vasc Surg 2005; 42: 502-509
CLF Reflux Free Rate at 3 Years– 96.0%Kaplan Meier Analysis
1. Patient had foam sclerotherapy and phlebectomy between years 2 and 3
2. Before recommendation to place catheter ≥ 2 cm from the SFJ
Evolution of RF Endovenous AblationSummary
ClosureFAST ClosureFAST More efficient design and reliable mode of action than More efficient design and reliable mode of action than
older RF devicesolder RF devicesMore User FriendlyMore User FriendlyBetter Vein Occlusion and Reflux Free ratesBetter Vein Occlusion and Reflux Free ratesSimilar mild recovery and long term symptom relief Similar mild recovery and long term symptom relief
profileprofileEquivalent or lower complication ratesEquivalent or lower complication rates
Evolution of Endovenous Ablation: Closure and ClosurePlus (CLP) – 1st Generation
Design and Mode of Action• Electrodes for transfer of RF energy to vein wall (bipolar technology)– Heats vein wall to 850C
• Continuous catheter pullback during treatment
• Thermocouple monitors vein wall temperature and impedance with feedback loop to generator
• Saline drip required
• Two catheter sizes • 6F and 8F
Bipolar Continuous Pullback Technology
RF Ablation How the Device has Evolved
VNUS MedicalTechnologies is founded - 1995
RF energy: Restore catheter
0.0250.025”” lumen lumen
Closure Catheter - 2001
ClosurePlus – 2003Integrated handle
First Generation RF DeviceLimitations
Operator Dependent treatment variability Inadequate Transfer of Energy• Pullback too fast (>2-3cm/min)
• speed – decrease energy delivery
• Inadequate tumescent compression
•Poor Electrode Contact with vein wall
• Especially vein diameters >12mm (supine)
• Only small area of vein is treated at any given time
2–3cm/min
First Generation Device - CLPEase of Use
Slow pullback speeds 2-3cm/min
Impedance monitoring
Generator Shut-off
Clean electrodes
High Impedance
Char buildup
Start Again!!!
First Generation RFA Devices – Closure and
ClosurePlusDesign and Mode of ActionElectrodes for transfer of
RF energy to vein wall (bipolar technology)– Heats vein wall to 850C
Continuous catheter pullback during treatment
Thermocouple monitors vein wall temperature and impedance with feedback loop to generator
Saline drip requiredTwo catheter sizes
6F and 8F
New Generation RF - ClosureFAST Design and Mode of Action
RF Energy heats Catheter tip (7cm heating element) to 120° C
Conductive Heat Transfer from heating element to vein wall achieves temperatures of 100-110°C Vein wall heating only when catheter is stationary (energy dosage not physician-dependant)
No impedance monitoring No saline drip
Small saphenous
Intersaphenous
Anterior accessory saphenous
Posterior accessory saphenous
Source: Laredo, J, et al. Endovenous Thermal Ablation of the Anterior Accessory Great Saphenous Vein
18%
10%
Great saphenous
70%
Various Sources of Superficial Venous Reflux
What’s Next in RF?Back to the futureOlympus Celon RFiTT ProceduOlympus Celon RFiTT ProcedurereDeveloped in 2007 as alternative to VNUSDeveloped in 2007 as alternative to VNUSUses Bipolar technologyUses Bipolar technology
Resistive heating of the vein wallResistive heating of the vein wall 20 J/cm vs 60-80 J/cm with CLF20 J/cm vs 60-80 J/cm with CLF
Olympus Celon RFiTT ProcedureOlympus Celon RFiTT ProcedureDeveloped in 2007 as alternative Developed in 2007 as alternative to VNUSto VNUSUses Bipolar technologyUses Bipolar technology
Resistive heatingResistive heating of the vein wall of the vein wall 20 J/cm vs 60-80 J/cm with CLF20 J/cm vs 60-80 J/cm with CLF
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Continuous Bipolar RF Technology Limitations
2–3cm/min
Rx area
• Based on the same technology as the ClosureFast™ catheter with a 4cm shorter heating element
• Shorter segmental ablation with the versatility to treat various sources of superficial venous reflux
7cm
3cm
ClosureFAST 3cm
Segmental RF AblationMost Recent Improvement
Rx 3 - 5cm vein segments
Continuous Monopolar RF
AdvantagesAdvantagesCatheters are thin (5Fr sheath) and pliableCatheters are thin (5Fr sheath) and pliable
Better for tortuous veins?Better for tortuous veins?
Significantly cheaper catheters than Significantly cheaper catheters than Segmental cathetersSegmental catheters
DisadvantagesDisadvantagesMay take longer than Segmental RFMay take longer than Segmental RFPull back technology – may lead to Pull back technology – may lead to
inconsistent resultsinconsistent results
Pain Score at follow-up visits1
(Scale: 0 none to 10 max)p < 0.0001 p < 0.0001 p < 0.0001 NS