Thermal Ablation 101: Basics of RF and Laser

Transcription

1 1:48-2:00 Now 11 min flying Thermal ablation indications, contraindications, results, complications (30 min) Thermal Ablation 101: Basics of RF and Laser Nick Morrison, MD, FACPh, FACS, RPhS President, International Union of Phlebology Past-President, American College of Phlebology Member, American College of Phlebology Foundation Grand Canyon, Arizona NOT Utah, Nevada, Colorado!

2 Saguaro Ski Resort, Cactus Superstition Northern Arizona Mts., (10,500 ) Arizona Disclosures Educational Grant, Speakers Bureau mediusa Consultant Merz SAB, Research Grant Speakers Bureau Medtronic Speakers Bureau Pierre-Fabre Speakers Bureau Craveri Medical Director Morrison Vein/Training Institute

3 Historical Information Important For Thermal Ablation History of STP or DVT Technical limitations if truncal STP Compromised outflow Prior Rx Even visual sclerotherapy may damage truncal veins and hinder access or catheter advancement Pt or Family Hx of thrombosis, multiple miscarriages, cryptogenic stroke Workup/possible Rx of thrombophilia Stirling M, Shortell C. Endovascular techniques for superficial vein ablation in treatment of venous ulcers. In: Bergan J, Shortell C, editors.venous Ulcers. San Diego: Elsevier: p

4 Important Physical Findings for Thermal Ablation Examine patient in the standing position, from the groin to the ankle Inspect and palpate for varicose and telangiectatic veins tortuosity medial thigh? Inspect the abdomen for enlarged superficial veins if ilio-femoral thrombosis is suspected Healed surgical incisions clues to previous Rx Watch patient walk for calf pump dysfunction It is NOT true that lower CEAP classification patients (C2,C3) are predominantly secondary to superficial venous insufficiency and higher CEAP classification patients (C4-C6) patients are primarily associated with deep venous disease. Thus, the need for detailed deep AND superficial duplex information Marston W. Conventional Surgery for Chronic Venous Insufficiency. In: Bergan J, ed. The Vein Book, 1 st ed. San Diego, Elsevier, p

5 Indications for Thermal Ablation Symptoms and physical signs of venous insufficiency Standing Duplex scan, performed by a fully qualified sonographer, showing a patent vein with reflux > 0.5sec Patent deep venous system Vein conducive to catheterization or injection Adequate patient mobility Morrison N. VNUS Closure of the Saphenous Vein. In: Bergan J, ed. The Vein Book, 1 st ed. San Diego, Elsevier, p

6 Indications for Thermal Ablation +/- Deep venous reflux +/- Hx of sclerotherapy or phlebectomy +/- Chronic anticoagulant therapy or hormone replacement therapy Age: minimal restrictions, given adequate mobility +/- Mildly tortuous or large diameter GSV s Proebstle T. Endovenous Laser (EVL) for Saphenous Vein Ablation. In: Bergan J, ed. The Vein Book, 1 st ed. San Diego, Elsevier, p Morrison N. VNUS Closure of the Saphenous Vein. In: Bergan J, ed. The Vein Book, 1 st ed. San Diego, Elsevier, p

7 Indications for Thermal Ablation Which veins? Incompetent Great Saphenous Vein Small Saphenous Vein Accessory Saphenous Vein Vein of Giacomini Cranial Extension of SSV Perforators

8 Indications for Thermal Ablation Where To Treat?? Below knee Risk of Paresthesia Small saphenous vein Avoid most proximal portion Tributaries, cranial extension of SSV If non-tortuous Perforators Technically more difficult

9 THERMAL ABLATION: CONTRAINDICATIONS Absolute Acute DVT, SVT Acute infection Deep venous obstruction Relative Immobile ABI < 0.5 Lidocaine sensitivity VTE risk Pregnancy Edema Severe Systemic Illness Tortuous Vein Sclerotic Vein <3mm??

10 Preoperative Assessment Signs and symptoms of CVI Duplex scan with GSV Reflux (>0.5sec) MANDATORY ABI if any indication of significant PAD CWD for screening? Other physiologic testing largely research tools Marston W. Conventional Surgery for Chronic Venous Insufficiency. In: Bergan J, ed. The Vein Book, 1 st ed. San Diego, Elsevier, p

11 Endovenous Thermal Ablation Procedures RF and Laser Electromagnetic energy destroys vein wall Steam Direct thermal injury water heated to 120 C Source: The Vein Book Chapter 17

12 Endovenous Thermal Ablation Radiofrequency ClosureFast segmental heating Olympus RFTT bipolar continuous heating Venclose selective sectional heating Laser-mediated 808 nm (Eufoton) 810 nm (Varilase) 940 nm (Dornier) 980 nm (Bio-Med USA, Angiodynamics) 1319nm (Sciton) 1320 nm (CoolTouch) 1470 nm (Angiodynamics) 1500 nm (Inter-Medic) 1560nm (IRE-Polus)

13 Endovenous Thermal Ablation Principles RF (USA - 2, European) direct contact 120 C Laser - Variable wavelength/absorption near infrared spectral field ( nm) Fibers µm Recently trend higher wavelength lasers Blood primary target up to 1000nm steam vs direct contact for wall destruction Water primary target above 1300nm wall is direct target Higher vs lower wavelength lasers fewer side effects

14 Thermal Ablation Procedure Ultrasound Guided GSV Access

15 Thermal Ablation Procedure Ultrasound-guided Vein Access

16 Thermal Ablation Procedure Guide Wire Insertion Guide Wire Insertion Caution

17 Thermal Ablation Procedure Sheath over guide wire Guide wire removed Fiber through sheath and advanced

18 Thermal Ablation Procedure Position of fiber tip in GSV

19 Thermal Ablation Procedure Ultrasound-Guided Tumescent Anesthesia Video clip courtesy: Rob Min, MD

20 Thermal Ablation Procedure Tumescence Anesthesia Longitudinal view Tumescent Anesthesia Injection Transverse View

21 Thermal Ablation Procedure Laser activation RF Activation

22 Thermal Ablation Follow-Up Duplex scan immediately postop to ensure patency of SFJ, CFA, CFV, Popliteal vein, deep venous system Patient Interview, examination, and Duplex Scan (?): 1 wk, 3-6 mos, 12 mos, yearly thereafter??

23 Post Thermal Ablation Patient Care Compression: Immediate, prior to ambulation Evidence: sketchy 30-40mm Hg thigh/panty? Short stretch wraps? Duration (1-3 wks)? Days only

24 Thermal Ablation Follow-Up Incompetent distal saphenous vein, incompetent tributaries and persistently incompetent perforators MUST be eliminated to avoid high rate of recurrent patency in saphenous vein Personal Opinion - NM

25 Thermal Ablation Follow-Up Adjuntive Treatment Options: Ambulatory Phlebectomy Concurrent vs. delayed Ultrasound-Guided Foam Sclerotherapy Traditional Surgical Ligation of Perforators Subfascial Endoscopic Perforator Surgery Transilluminated Powered Phlebectomy Surface Sclerotherapy Source: The Vein Book Chapter 55

26 Endovenous Thermal Ablation - Results Results reported in literature: RF 83-90% 2-5 years Laser % 1-5 years

27 Endovenous Thermal Ablation - Results RF vs Laser - Results/Complications Prospective randomized study 131 pts RF (ClosureFast) vs 980nm postoperative pain analgesic requirements Results: RF 3 and 10-day pain scores lower (p=0.010, p=0.001) RF 3 and 10-day analgesic lower (p=0.003, p=0.001) Shepherd A, et al. Br J Surg Jun;97(6):810-8

28 Thermal Ablation (Steam) Proof-of-principle study of steam ablation as novel thermal therapy for saphenous varicose veins. INTRODUCTION: Endovenous Thermal Ablation - Results Works by heating the vein with steam at 120 C AIM: assess the effectiveness of steam ablation of varicose veins in sheep and in humans. METHODS: Safety in sheep assessed by cardiovascular monitoring during treatment Ultrasound imaging to examine occlusion Changes in treated veins examined microscopically Pilot study, 20 veins in 19 patients - great or small saphenous vein treated with pulsated steam ablation Anatomic success, patient satisfaction, and complications for 6 months van den Bos R, Milleret R, et al. J Vasc Surg 2011 Jan;53(1):181-6.

29 Endovenous Thermal Ablation - Results Thermal Ablation (Steam) RESULTS: All sheep veins occluded No cardiovascular changes Histologic examination of treated veins showed changes of vein wall typical for thermal ablation Steam ablation effective in the 19 patients 13 of 20 veins completely closed 7 showed a very small segment of recanalization at 6 months No serious side effects (deep vein thrombosis, nerve injury, skin burns, infections) Patients very satisfied with treatment CONCLUSIONS: In this proof-of-principle study, pulsated steam ablation was an effective treatment for saphenous varicose veins van den Bos R, Milleret R, et al. J Vasc Surg 2011 Jan;53(1):181-6.

30 Endovenous Thermal Ablation - Results RF vs Laser vs Surgery vs Foam (low/high wavelength lasers combined) 580 GSVs randomized Duplex 3 days, 1 month, 1 year, 3 years Results: GSV Patent w/ reflux: laser 7% RF 7% Foam 26% (technical success < with foam: P < 0 001) Surgery 6% (P < 0 001). Rasmussen L, et al. Randomized clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins with 3-year follow-up. J Vasc Surg Venous and Lym Dis 2013;1:

31 Aim - to establish whether increasing energy results in greater peri-procedural morbidity or complications Outcomes: pain and analgesia requirement in week 1 change in disease specific quality of life (AVVQ) change in generic quality of life (SF-36) and Euroqol at week 1 and 6 complication rates 232 patients Mean (range) energy delivery was 89.8 ( ) J/cm 810nm laser Conclusion: Endovenous Thermal Ablation - Results Laser Energy Delivered Up to 160J/cm, increasing energy delivery has no significant effect upon the morbidity or complications of EVLT for superficial venous insufficiency Carradice D, et al. Eur J Vasc Endovasc Surg (2010) 40,

32 Endovenous Thermal Ablation - Results Lower vs Higher Wavelength Higher wavelengths Water vs Hb chromophore Less early postoperative bruising/pain Covered/radial fiber more uniform energy distribution less perforation Energy delivered joules/cm lower wavelength 30-70joules/cm higher wavelength Single use fibers beware repeated use fiber fracture

33 Endovenous Thermal Ablation - Complications Intra-operative Complications Retained/migrating catheter/fiber Prevention: Pay attention to Fiber/sheath retraction! Treatment: Pt awareness Removal AP with ultrasound If migrated, IR

34 Endovenous Thermal Ablation - Complications Intra-operative Complications Transient Heat Prevention: Avoid inadequate anesthesia Better placement in saphenous sheath Treatment: More local volume

35 Endovenous Thermal Ablation - Complications Intra-operative Complications Technical Challenges Difficulty advancing wire/catheter Prevention: Leg straightening Treatment: Ultrasound probe compression External manipulation 2 nd site cephalad

36 Endovenous Thermal Ablation - Complications Postoperative complications DVT ~1% Most calf -? Clinical significance Proximal aggressive Rx IR - thrombolytic/thrombectomy +/- anticoagulation The Vein Book Thrombotic Risk Assessment: A Hybrid Approach, Caprini J Venous thromboembolism Prophylazxis in the General Surgical Patient, Caprini J, Arcelus JI

37 Endovenous Thermal Ablation - Complications GSV Thrombus Extending Into CFV (? Clinical Significance)

38 Endovenous Thermal Ablation - Complications Post-Op Complications Paresthesia Prevention: Well-placed, adequate volume of local anesthetic in saphenous sheath Treatment: Time will likely resolve in 3-4 months

39 Lidocaine Toxicity Endovenous Thermal Ablation - Complications 7mg/kg 1-560mL of 0.1% in 80 kg pt 45mg/kg mL Targeted to saph sheath 0.1% lidocaine w/o epinephrine for EVLT 3 up to 655mL injected No adverse reactions 1 Klein JA. Dermatol Clin Oct;17(4): Klein JA. Lidocaine dosage for tumescent anesthesia. Presentation, UIP Monaco, Sept Hudson A, et al. Tumescent technique without epinephrine for EVLT and serum lidocaine concentration. J Vasc Surg Venous and Lym Dis 2015;3(1):48-53.

40 Endovenous Thermal Ablation - Complications Recanalization Treatment Failures What to do? Repeat treatment for persistent incomplete ablation Follow-up ultrasound-guided foam sclerotherapy to patent segment of great saphenous vein at the time identified

41 Endovenous Thermal Ablation - Complications Aim Recanalization Methods Results Assess significance of recanalization following laser ablation of GSV 27 legs 6-12 wks Duplex, 1 yr ALL remained 1 yr with or w/o reflux (41% vs 59%) AVVSS remained improved Competent tributaries following EVLA do not adversely impact clinical outcome Theivacumar NS, et al. Eur J Vasc Endovasc Surg (2008) 36,

42 Endovenous Thermal Ablation - Complications Case Report 32 y/o woman 3 wks post GSV laser Presents with leg swelling, pain, and high output cardiac failure Dx by Hx, auscultation, and CT angio revealed EIA-EIV fistula and CFA-CFV fistula Rx CFA/EIA stent w/ complete resolution of symptoms Ziporin S, et al. Case of external iliac arteriovenous fistula and high-output cardiac failure after EVLT of GSV.J Vasc Surg 2010;51:715-9

43 Endovenous Thermal Ablation - Complications 59 y/o female previous hx of breast ca Negative for thrombophilia endovenous laser local anesthesia, mild sedation 5 days post procedure Rt. Hemiparesis, global aphasia permanent at 1 year US complete Lt. MCA occlusion 2 weeks Duplex of LE s no DVT 1 month TEE shows PFO with Grade 3 shunt Caggiati A, Franceschini M. Stroke following endovenous laser treatment of varicose veins. J Vasc Surg 2010;51:

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45 Thank you for your kind attention