Deep Vein Thrombosis

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Provided by Elsevier - Publisher Connector Eur J Vasc Endovasc Surg (2010) 40, 521e527

Deep Vein Thrombosis (DVT) after Venous Thermoablation Techniques: Rates of Endovenous Heat-induced Thrombosis (EHIT) and Classical DVT after Radiofrequency and Endovenous Laser Ablation in a Single Centre*

P. Marsh, B.A. Price, J. Holdstock, C. Harrison, M.S. Whiteley*

The Whiteley Clinic, 1, Stirling House, Stirling Road, Guildford GU2 7RF, UK

Submitted 15 June 2009; accepted 8 May 2010 Available online 23 July 2010

KEYWORDS Abstract Introduction: Deep vein thrombosis (DVT) after varicose vein surgery is well recog- Varicose veins; nised. Less well documented is endovenous heat-induced thrombosis (EHIT), thrombus exten- Venous thrombosis; sion into a deep vein after superficial venous thermoablation. We examined the rates of DVT in Venous insufficiency; our unit after radiofrequency (RFA) and endovenous laser ablation (EVLA) with specific atten- Catheter ablation; tion to thrombus type. Laser therapy Method: Retrospective analysis of all cases of RFA under general anaesthesia and EVLA under local anaesthesia was performed. Cases of DVT were identified from the unit database and analysed for procedural details. Results: In total, 2470 cases of RFA and 350 of EVLA were performed. Post-RFA, DVT was identified in 17 limbs (0.7%); 4 were EHIT (0.2%). Concomitant small saphenous vein (SSV) ligation and stripping was a risk factor for calf-DVT (OR 3.4, 95%CI 1.2e9.7, P Z 0.036), possibly due to an older patient group with more severe disease. Post-EVLA, 4 DVTs were identified (1%), of which 3 were EHIT (0.9%). Conclusion: The DVT rate including EHIT was similar in patients treated with RFA and EVLA and was low. Routine post-operative duplex ultrasound scanning is recommended until the significance of EHIT is better understood, in accordance with consensus guidelines. DVT rates for both techniques compare favourably with those published for saphenous vein stripping. ª 2010 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

* Presented at the Annual Scientiﬁc Meeting of the Association of Surgeons of Great Britain and Ireland, Manchester 2007, Session W2c1 Venous Disease 0887 (ASGBI abstracts 2007 Oral presentations. Br J Surg 2007;94(S2): 1e78). * Corresponding author. Tel.: þ44 8707661234; fax: þ44 1483 477194. E-mail address: [email protected] (M.S. Whiteley).

Introduction was cannulated percutaneously just below the knee. A 0.025- inch guide-wire was then inserted proximally to the CFV using Deep vein thrombosis (DVT) after varicose vein surgery is the Seldinger technique. An RFA catheter, 6F or 8F according well recognised.1,2 With the growing popularity of endo- to the diameter of the GSV, connected to a pressurised hep- venous thermo-ablative techniques, there have been arinised saline infusion (5000 U in 500 ml of saline solution, numerous reports of the complication Endovenous Heat- 150 mmHg) was introduced as far as the saphenofemoral Induced Thrombosis (HIT).3,4 EHIT is thrombus extending junction (SFJ). The leg was then bound with an Esmarch from the superficial venous system into the deep venous bandage to ensure good contact between the vein wall and system at, or proximal to, a site of recent thermoablation, catheter electrodes by venous exsanguination. After con- most commonly thrombus extending from the great firming the proximal limit of the catheter to be within 2 cm of saphenous vein (GSV) into the common femoral vein (CFV, the SFJ, radiofrequency energy delivery was commenced with Fig. 1).5 The aim of this study was to compare rates of a temperature of 85 C. An initial “ring burn” was delivered for venous thromboembolism (VTE) after endovenous radio- 15 s, and the catheter was then withdrawn a distance of 1 cm e frequency (RFA) and laser ablation (EVLA) with specific in the first minute, 2 cm in the second minute, and 2.5 3cm/ attention to thrombus type and risk factors. min thereafter, depending on the diameter of the vein. Post- procedure, the vein was checked immediately with duplex ultrasound (DUS) for closure. Any incompetent tributaries of Method the GSV were treated concomitantly, as were incompetent perforator veins (IPV), either with DUS-guided perforator A retrospective analysis of all cases of RFA and EVLA performed ligation or TransLuminal Occlusion of Perforator (TRLOP) with in the unit from February 1999 to March 2007 was conducted. RFA.8 Adjunctive phlebectomies were also performed to Cases of DVT were identified from the unit database in which remove superficial varicosities which had been marked pre- patient demographics, severity of venous insufficiency operatively on the skin. Incompetent small saphenous veins 6 according to CEAP clinical classification, procedural details (SSV) were treated with concomitant DUS-guided sapheno- and all complications are prospectively recorded. For those popliteal ligation and strip as previously described.9 After the patients in whom post-operative DVT was identified, case procedure a creˆpe bandage was applied firmly to the leg and notes were examined for previous venous thromboembolism thigh over Velband (Johnson & Johnson Medical, Ascot, (VTE), VTE risk factors, history of varicose vein surgery and Berkshire). This was replaced the next day with a graduated procedural details. Redo procedures were classified as surgery compression stocking. to the same vein if any previous intervention had been performed (e.g. ligation or stripping procedure). Endovenous laser ablation Radiofrequency ablation EVLA was introduced as a treatment option to patients in Our technique for RFA has previously been described.7 Briefly, the unit in May 2005, and all cases performed to March 2007 all cases in this study were performed under general anaes- were included. All cases of EVLA were performed under thesia (GA) using the Closure system (VNUS medical tech- tumescent local anaesthesia as walk-in, walk-out proce- nologies, San Jose, California). Tumescent local anaesthesia dures. The GSV was cannulated percutaneously just below was not used. High resolution scanners (Acuson Cypress, the knee under ultrasound guidance using the Seldinger Siemens, Issaquah, USA) handled by experienced vascular technique. The laser sheath was advanced to the SFJ and technologists were used for all procedures. A linear 7 MHz the guide-wire removed. Tumescent anaesthesia was infil- probe (Acuson Cypress) was inserted in a sterile cover with trated in the perivenous space under ultrasound guidance acoustic coupling gel and using ultrasound guidance the GSV (Acuson Cypress) using an AutoFill syringe (Vascular Solutions Inc., Minneapolis, USA). 0.5 l of tumescent local anaesthesia was prepared using 500 ml 0.9% saline, 20 ml of 2% xylocaine and adrenaline and 5 ml of 8.4% sodium bicarbonate according to Klein’s formula.10 The laser fibre was inserted to a position within 2 cm of the SFJ with ultrasound guidance and connected to an 810 nm diode laser (Vari-Lase, Vascular Solutions Inc., Minneapolis, USA). Laser energy was then administered at 14 W power using a continuous setting, aiming for a linear energy delivery target of 70 J/cm. Refluxing tributaries were treated with EVLA concomitantly. Treatment of superficial varicosities and IPV was performed at a later date.

Pre-operative evaluation and post-operative follow-up Figure 1 Appearance of Endovenous Heat-induced thrombosis (EHIT) extending from the great saphenous vein (GSV) into the All patients were diagnosed pre-operatively with superﬁcial common femoral vein (CFV) on duplex ultrasound scan. venous insufﬁciency according to DUS (SONOLINE Antares, DVT and EHIT after Endovenous Thermoablation 523

Siemens, Issaquah, USA) using a standard protocol and Table 1 Patient characteristics. treatment was guided by DUS-directed vein mapping. Vein incompetence was assessed with reflux in response to RFA EVLA manual calf compression or Valsalva manoeuvre with the n Z 2470 n Z 350 patient standing and reflux was defined as evidence of Median age/y 53 (SD Z 13) 57 (SD Z 14) 11 reverse flow >500 ms in a vein segment. Any patients F/M 2.8/1 2.8/1 undergoing endovenous thermoablation procedures CEAP clinical score 2(1e6) 2 (1e6) routinely received one dose of low molecular weight (LMW) (median, range) heparin prophylaxis (4000 i.u. enoxaparin sodium, Sanofi- aventis, Guildford, UK), unless warfarinised for co-morbid % limbs in conditions (immediately post-operatively for EVLA, intra- CEAP Class 0 1 2 operatively for RFA). All patients were given 20e30 mm Hg 117 graduated compression stockings (Venosan, Saltzman, 27061 Switzerland) to wear 24 h a day for at least 3 days. Routine 363 mobilisation was encouraged for the post-operative period. 41821 A duplex ultrasound examination was performed within the 522 first two post-operative weeks, to assess the treated vein 613 segment and exclude DVT, with special attention paid to the RFA, radiofrequency ablation, EVLA, endovenous laser ablation, SFJ and calf muscle veins. EHIT was classified as previously SD, standard deviation. described. The presence of thrombus in gastrocnemius, posterior tibial or popliteal veins was classified as calf-DVT.

since this event occurred in very few patients no reliable Statistical analysis statistical analysis is possible (Table 2).

Statistical analysis was performed using Interstat 3 and Prism software (GraphPad Software, Inc., San Diego, California, Risk factors for DVT and EHIT USA). Intergroup comparisons were made with the Student t or ManneWhitney u test as appropriate for normally and non- There was no significant difference between the age of the normally distributed data, respectively (TT). Univariate patients who had a calf-DVTor EHIT post-RFA or EVLA and the analysis was performed to estimate the effect of selected population undergoing RFA as a whole, nor was there risk factors using the chi-squared test for contingency tables. a difference in the proportions of limbs in each clinical score. A P value <0.05 was considered statistically significant. Of the patients with calf-DVT post-RFA, 3 had previous DVT (21%). None of the patients with EHIT post-RFA had a history Results of DVT, in contrast with 2 of 3 patients with the condition post-EVLA, one of whom had evidence of this on pre-operative DUS. Other possible risk factors were present for 2 of the Patient characteristics calf-DVT post-RFA (no cessation of oral contraceptive pill, hormone replacement therapy use), though for none of the RFA was performed on 2470 limbs and EVLA on 350 limbs during EHIT in the series. All patients with calf-DVT or EHIT had the period examined. Patient demographics are summarised received heparin prophylaxis (Table 4). (Table 1). Basic patient characteristics were similar with the Post-RFA, the rate of calf-DVT for bilateral surgery exception of the higher median age in the EVLA group. compared with unilateral surgery was similar (P Z N.S.). Redo surgery compared with primary surgery did not cause Post-operative DVT and EHIT a higher rate of DVT. Concomitant small saphenous surgery (SST) with RFA was found to be a risk factor for calf-DVT Post-RFA, DVT was identified in 17 limbs (0.7%). Of these, 4 when compared with RFA and no small saphenous surgery were EHITand 14 were calf-DVT. In one patient, both types of (P Z 0.036). No significant difference was seen between thromboses were present, along with pulmonary embolism the rate of calf-DVT for concomitant RFA and SST proce- (PE). This was the only case of PE (confirmed on CT pulmonary dures, and small saphenous surgery procedures performed angiography) in the series (0.04%). The patient presented at in the same period alone (P Z N.S.) suggesting concomitant routine follow-up 8 days post-RFA complaining of foot drop small saphenous surgery itself to be a possible risk factor since the procedure and chest pain for 36-h. Nerve conduc- for calf-DVT post-RFA. Further analysis demonstrated that tion studies demonstrated no abnormality and the patient patients in the RFA and concomitant SST group were made a full recovery. Post-EVLA, 4 DVTs were identified (1%): significantly older, with limbs in a higher CEAP clinical class of these, 3 were EHIT and one a calf-DVT, all post-GSV abla- than patients who had RFA without SST (P Z 0.028 and tion. The calf-DVT presented after the patient underwent P 0.0001). When comparing those groups having any small subsequent treatment of an IPV. Length of GSV treated and saphenous surgery (RFA þ SST or SST alone), patients were energy applied in each case are described (Table 3). Of the similar for age and CEAP clinical class. limbs treated with EVLA, 48 cases were small saphenous The significance of treatment of IPVs with the TRLOP veins. There was no DVT or EHIT in this sub-group. The method was also examined. An increased OR of calf-DVT was frequency of EHIT was similar following RFA and EVLA but seen after RFA and TRLOP compared with RFA and no TRLOP 524 P. Marsh et al.

Table 2 DVT and HIT rates after RFA and EVLA. RFA EVLA P (c2)CI Total no. of limbs 2470 350 Any DVT (%) 17 (0.7) 4 (1) 0.55 (0.35) 0.20e1.80 Calf-DVT (%) 14 (0.57) 1 (0.3) 0.77 (0.08) 0.26e15 EHIT (%) 4 (0.16) 3 (0.9) 0.06 (3.5) 0.04e0.84 PE (%) 1 (0.04) 0 e CI, conﬁdence interval, DVT, deep vein thrombosis, EHIT, endovenous heat-induced thrombosis, PE, pulmonary embolism, RFA, radiofrequency ablation, EVLA, endovenous laser ablation, c2, chi-square.

(OR 5.8, P Z 0.02). No significant difference in the rate of post-EVLA (in whom the DVT resolved without treatment calf-DVT after RFA and TRLOP was seen compared with after 5 days), all patients with isolated calf-DVT post-RFA and TRLOP alone performed without RFA of a truncal vein in the EVLA were warfarinised (mean 10 weeks, range 3e14 weeks). same period (OR 3.4, P Z 0.28). It was noted that 6 of the No caval filters were utilised. calf-DVT seen after TRLOP were also associated with small saphenous surgery, and so these were analysed separately. Discussion There was no increased risk of calf-DVT after RFA and TRLOP and no small saphenous surgery compared with RFA alone We found a low incidence of DVT after EVLA and RFA in this (also excluding those with small saphenous surgery). retrospective analysis with no clear difference between However, the odds ratio of calf-DVTafter RFA and TRLOP with these treatments and very few EHITs were seen. The mech- small saphenous surgery was significantly elevated when anism of EHIT formation is not fully understood. Superficial compared with RFA and TRLOP and no small saphenous venous thrombus is expected following thermoablation, Z surgery (OR 3.5, P 0.03). Of the calf-DVT seen with whether this is by thrombotic vessel occlusion or local vessel concomitant small saphenous surgery, all patients also had injury from direct thermal damage or steam bubbles.12,13 Z concomitant treatment of an IPV in the same limb (n 7). Thrombus may form in the deep veins or propagate from Although 6 of these had the TRLOP procedure, 1 patient had treated superficial veins to the deep veins. duplex-guided perforator ligation. The OR of calf-DVT with Reported rates of DVT post-endovenous ablation tech- RFA and small saphenous surgery and treatment of an IPV was niques vary widely from 0 to 16% post-RFA and 0 to 7.7% significantly elevated compared with those who did not have post-EVLA.4 Rates after conventional surgery vary between Z IPV treatment (OR 14.7, P 0.015, Table 5). 0.4% historically and 5.7% with prospective ultrasound.1,2 The series reported here includes our learning curve for Management of DVT/EHIT EVLA but despite this we did not observe a difference in DVT rates between EVLA and RFA. The management of patients with EHIT evolved in the series Factors which may increase the risk of EHIT include: (Table 6). The first patient with EHIT post-RFA was managed patient age, undiagnosed hypercoagulable states and with open saphenofemoral thrombectomy, SFJ ligation and severity of chronic venous disease.14,15 Factors related to anticoagulation with warfarin for 6 weeks. Subsequently, the procedure include: the use of GA, maintenance of the patients with isolated EHIT post-RFA were treated patency of superficial venous tributaries at the most prox- medically with warfarin for a one-month period (3-months imal point of thermoablation, avoidance of catheterising the for the patient with PE). CFV to avoid intimal damage and the avoidance of propa- Similarly for patients with EHIT post-EVLA: one patient gation of steam bubbles (or thrombus) by compression or was warfarinised for a 1-month period, one patient was ligation of the SFJ, though a recent survey has indicated no treated with a therapeutic once e daily dose of low molec- difference in DVT rate of ligators and non-ligators.3,16e18 Our ular weight heparin and one patient was observed without practice was to perform RFA under GA using an Esmarch treatment, without consequence. Regression of thrombus bandage to exsanguinate the limb. We did not use tumescent from the deep vein was established on DUS before cessation anaesthesia in this group in order to avoid the “heat sink” of anticoagulation in all patients. With the exception of the effect, without adversely affecting the DVT rate. Addition- patient with calf-DVT thought to be related to IPV treatment ally, it has been our practice to perform concomitant

Table 3 Length of great saphenous vein treated with endovenous laser ablation and the amount of energy delivered in cases complicated by HIT or DVT. Case no. Type of thrombus Length of GSV treated (cm) Total laser energy (J) LEED (J/cm)) 1 EHIT 9 582 64.7 2 EHIT 22.8 1574 69.0 3 EHIT 31 2127 68.6 4 DVT 20 1446 72.3 GSV, great saphenous vein, DVT, deep vein thrombosis, EHIT, endovenous heat-induced thrombosis, LEED, linear endovenous energy density. DVT and EHIT after Endovenous Thermoablation 525

Table 4 Risk factors for venous thromboembolism and procedural factors for patients with DVT or HIT post-endovenous thermoablation. No. of Median Age C2 C3 C4 Previous Other Bilateral Redo SST TRLOP RFA of cases of (range) DVT RF surgery AAGSV DVT RFA Calf-DVT 14 47 (39e69) 10 0 4 3 2 2 4 7 12 4 EHIT 4 56 (42e69) 2 1 1 0 0 2 0 0 2 1 EVLA Calf-DVT 1 e 00 1 0 0 e 0 e 00 EHIT 3 58 (57e75) 1 0 2 2 0 e 0 e 00 DVT, deep vein thrombosis, EHIT, endovenous heat-induced thrombosis, PE, pulmonary embolism, RFA, radiofrequency ablation, EVLA, endovenous laser ablation, RF, risk factor, SST, small saphenous surgery, TRLOP, transluminal occlusion of perforator, AAGSV, anterior accessory great saphenous vein. phlebectomy in these patients. In the first 127 cases of RFA enabled further analysis of this sub-group. Surprisingly the rate performed in this series, we found that 57% of superficial of calf-DVT was reduced in patients having bilateral surgery epigastric veins (SEV) remained patent with no relationship compared with unilateral, contrary to expectation and findings with neovascularisation at the SFJ or GSV recanalisation, of others.20 The significantly increased rate of calf-DVTseen in a finding also seen post-EVLA.7,19 Nevertheless, it has not patients undergoing concomitant small saphenous surgery and been our practice to routinely commence ablation below this RFA is possibly attributable to the increased age and clinical vein in part due to the variability of its site. We commenced severity score in this group of patients, as their risk of calf-DVT thermoablation within 2 cm of the SFJ, regardless of SEV site was found to be similar to those undergoing small saphenous and routinely used a guide-wire, placing the catheter in the surgery alone. No DVT was seen following EVLA of small CFV and withdrawing the tip into the saphenofemoral hood. saphenous veins, although there were few of these cases. The small numbers of EHIT seen prevented meaningful Initially TRLOP appeared to be an isolated risk factor for analysis of risk factors but larger numbers of calf-DVT post-RFA calf-DVT but this was linked to concomitant small

Table 5 Risk factors for calf-DVT post-RFA. Risk factor N (%) DVT (%) OR (95%CI) Pa Bilateral surgery Bilateral RFA 1056 2 (0.2) 0.22 (0.05e0.99) 0.059 Unilateral RFA 1414 12 (0.8) ee

Redo surgery Redo surgery 597 4 (0.7) 1.26 (0.39e4.02) 0.94 Primary surgery 1873 10 (0.5) ee

Small saphenous surgery RFA þ SST 567 7 (1.3) 3.39 (1.18e9.70) 0.036 RFA no SST 1903 7 (0.4) ee SST no RFA 285 3 (1.0) 0.82 (0.22e3.32) 0.82

Treatment of IPV RFA þ TRLOP 1265 12 (0.9) 5.76 (1.29e25.8) 0.02 RFA no TRLOP 1205 2 (0.2) ee TRLOP no RFA 32 1 (3.2) 3.37 (0.42e26.7) 0.28 RFA þ TRLOP no SST 984 6 (0.6) 5.63 (0.68e46.9) 0.126 RFA no TRLOP no SST 919 1 (0.1) ee RFA þ TRLOP þ SST 289 6 (2.1) 3.46 (1.11e10.8) 0.03 RFA þ SST þ TRLOP 289 6 (2.1) 5.87 (0.70e49.1) 0.123 RFA þ SST no TRLOP 278 1 (0.4) ee RFA þ SST þ TIPV 290 7 (2.4) 14.7 (0.83e258) 0.015 RFA þ SST þ no TIPV 277 0 ee DVT, deep vein thrombosis, RFA, radiofrequency ablation, SST, small saphenous surgery, TIPV treatment of incompetent perforator vein TRLOP, transluminal occlusion of perforator, OR, odds ratio, CI, conﬁdence interval. a Univariate analysis using chi-square test. 526 P. Marsh et al.

Table 6 Treatment of venous thromboembolism post-RFA. Type of DVT Type of Deep vein Treatment Duration of thermoablation Number VTE containing treatment thrombus RFA 1 HIT CFV Thrombectomy, Warfarin 6 weeks 2 HIT CFV Warfarin 4 weeks 3 Calf DVT Gastroc. Warfarin 7 weeks 4 Calf DVT Gastroc. Observed e 5 Calf DVT Gastroc. Warfarin 12 weeks 6 Calf DVT PV Warfarin 12 weeks 7 Calf DVT Gastroc. Warfarin 12 weeks 8 Calf DVT Gastroc. Warfarin 4 weeks 9 Calf DVT PV Warfarin 14 weeks 10 Calf DVT Gastroc. Warfarin 12 weeks 11 Calf DVT, HIT, PE Gastroc. Warfarin 12 weeks 12 Calf DVT Gastroc. Warfarin 3 weeks 13 Calf DVT Gastroc. Warfarin 5 weeks 14 Calf DVT Gastroc. Warfarin 12 weeks 15 Calf DVT Gastroc. Warfarin 14 weeks 16 HIT CFV LMW heparin 5 days 17 Calf DVT Gastroc. þ PV Warfarin 12 weeks EVLA 1 HIT CFV Warfarin 4 weeks 2 HIT CFV Observed e 3 HIT CFV LMW heparin 1 week 4 Calf DVT PTV Observed e Gastroc., gastrocnemius vein, PV, popliteal vein, CFV, common femoral vein, PTV, posterior tibial vein.

saphenous surgery, with no increased risk of calf-DVT for would agree that such patients are probably most safely RFA with TRLOP in its absence. Any treatment of IPV with managed with LMW heparin until resolution on ultrasound in concomitant small saphenous surgery was associated with accordance with the suggested treatment algorithm Kabnick elevated risk of DVT. Whether this is a result of the small introduced with his classification system (Table 7).5 All cases saphenous surgical procedure itself or due to the increased of EHIT in this series were Kabnick class 2e4. age and more severe disease of these patients is unknown. The risk of pulmonary embolism from EHIT remains The number of IPVs present has been correlated with clin- undefined and is uncommon after open varicose vein ical severity and development of new IPV with worsening of surgery.28 We are unaware of any reports of patients with PE chronic venous disease.21,22 Varicose vein patients with directly in association with isolated EHIT, although there is more advanced disease appear to have a higher risk of DVT. a report where it is not clear if calf-DVT has been excluded.27 All patients with DVT or EHIT in this series received The patient in this study with PE had thrombus present in a single dose of prophylactic LMW heparin. Failure of this gastrocnemius veins as well as at the SFJ, similar to a previ- strategy for prophylaxis has been reported previously, ously described case.3 Routine post-operative DUS should be especially in patients with a history of VTE.1,23 This suggests performed specifically to seek the presence of EHIT in that a greater duration of prophylaxis may be appropriate accordance with consensus guidelines and therapeutic in patients with a history of VTE, as has been suggested management instigated and continued until absence of CFV previously.24 Pre-operative anticoagulation might interfere thrombus.5,29 with thrombotic vessel occlusion.25 A low DVT rate in a large series (0.1%) was attributed to post-operative Table 7 Classification system for endovenous heat- treatment with non-steroidal anti-inflammatory drugs for induced thrombosis described by Kabnick et al. their anti-platelet activity and analgesic effect.17 Class II graduated compression stockings may also be useful. Class Thrombus extension (from superficial EHIT management has evolved in published reports from vein) operative thrombectomy, and later anticoagulation was 1 Close proximity to superficial-deep introduced with or without saphenofemoral ligation.3,26 Caval venous junction filters and thrombolysis have also been used, though most 2 Extending beyond junction with authors now agree that treatment with low molecular weight cross-sectional diameter of <50% heparin is adequate for most cases.14,15,27 In this series, of the 3 Extending beyond junction with patients with EHIT post-EVLA, 2 were anticoagulated and one cross-sectional diameter of >50% was observed. The latter patient had a knuckle of thrombus 4 Totally occlusive deep venous protruding 1 cm into the femoral vein that was later seen to thrombosis have resolved with no adverse sequelae. Notwithstanding, we DVT and EHIT after Endovenous Thermoablation 527

The DVT rate including EHIT was similar in patients 11 Labropoulos N, Tiongson J, Pryor L, Tassiopoulos AK, Kang SS, treated with RFA and EVLA and was low. Calf-DVT occurred Ashraf Mansour M, et al. Definition of venous reflux in lower- in patients with a history of thromboembolism and in those extremity veins. J Vasc Surg 2003;38(4):793e8. being treated for more complex venous disease. DVT rates 12 Proebstle TM, Lehr HA, Kargl A, Espinola-Klein C, Rother W, for both endothermal ablation techniques compare Bethge S, et al. Endovenous treatment of the greater saphenous vein with a 940-nm diode laser: thrombotic occlusion after favourably with those published for saphenous vein endoluminal thermal damage by laser-generated steam stripping. bubbles. J Vasc Surg 2002;35(4):729e36. 13 Min RJ, Khilnani N, Zimmet SE. Endovenous laser treatment of saphenous vein reflux: long-term results. J Vasc Interv Radiol Funding 2003;14(8):991e6. 14 Puggioni A, Kalra M, Carmo M, Mozes G, Gloviczki P. Endovenous The Whiteley Foundation, registered charity 1099614, laser therapy and radiofrequency ablation of the great saphe- provided the funding for P. Marsh’s post. nous vein: analysis of early efficacy and complications. J Vasc Surg 2005;42(3):488e93. 15 Hingorani AP, Ascher E, Markevich N, Schutzer RW, Kallakuri S, Conflict of Interest Hou A, et al. Deep venous thrombosis after radiofrequency ablation of greater saphenous vein: a word of caution. J Vasc This study was not funded by any company nor was any Surg 2004;40(3):500e4. company informed of our work. 16 Gale SS, Dosick SM, Seiwert AJ, Comerota AJ. Regarding “Deep venous thrombosis after radiofrequency ablation of greater saphenous vein”. J Vasc Surg 2005;41(2):374. Month [author reply]. References 17 Bush RG. Regarding “Laser therapy and radiofrequency ablation of the great saphenous vein: analysis of early efficacy and compli- 1 van Rij AM, Chai J, Hill GB, Christie RA. Incidence of deep vein cations”. J Vasc Surg 2006;43(3):642 [author reply-3]. thrombosis after varicose vein surgery. Br J Surg 2004;91(12): 18 Gradman WS. Adjunctive proximal vein ligation with endove- 1582e5. nous obliteration of great saphenous vein reflux: does it have 2 Lofgren EP, Coates HL, O’Brien PC. Clinically suspect pulmonary clinical value? Ann Vasc Surg 2007;21(2):155e8. embolism after vein stripping. Mayo Clin Proc 1976;51(2): 19 Theivacumar NS, Dellagrammaticas D, Beale RJ, Mavor AI, 77e80. Gough MJ. Fate and clinical significance of saphenofemoral 3 Manfrini S, Gasbarro V, Danielsson G, Norgren L, Chandler JG, junction tributaries following endovenous laser ablation of Lennox AF, et al. Endovenous management of saphenous vein great saphenous vein. Br J Surg 2007;94(6):722e5. reflux. Endovenous Reflux Management Study Group. J Vasc 20 Defty C, Eardley N, Taylor M, Jones DR, Mason PF. A comparison of Surg 2000;32(2):330e42. the complication rates following unilateral and bilateral varicose 4 Mozes G, Kalra M, Carmo M, Swenson L, Gloviczki P. Extension of vein surgery. Eur J Vasc Endovasc Surg 2008;35(6):745e9. saphenous thrombus into the femoral vein: a potential 21 van Rij AM, Hill G, Gray C, Christie R, Macfarlane J, Thomson I. complication of new endovenous ablation techniques. J Vasc A prospective study of the fate of venous leg perforators after Surg 2005;41(1):130e5. varicose vein surgery. J Vasc Surg 2005;42(6):1156e62. 5 Kabnick LS, Ombrellino M, Agis H, Mortiz M, Almeida J, Baccaglini U, 22 Perrin MR, Labropoulos N, Leon Jr LR. Presentation of the et al. Endovenous heat induced thrombus (EHIT) at the superficial- patient with recurrent varices after surgery (REVAS). J Vasc Surg deep venous junction: a new post-treatment clinical entity, clas- 2006;43(2):327e34 [discussion 34]. sification and potential treatment strategies. 18th Annual Meeting 23 Enoch S, Woon E, Blair SD. Thromboprophylaxis can be omitted of the American Venous Forum, Miami, Florida; 2006. in selected patients undergoing varicose vein surgery and hernia 6 Porter JM, Moneta GL. Reporting standards in venous disease: repair. Br J Surg 2003;90(7):818e20. an update. International Consensus Committee on Chronic 24 Abbott D, Dharmarajah B, Davies A. Varicose vein surgery and Venous Disease. J Vasc Surg 1995;21(4):635e45. deep vein thrombosis prophylaxis. Phlebology 2007;22(1):1e2. 7 Fassiadis N, Kianifard B, Holdstock JM, Whiteley MS. Ultrasound 25 Gibson KD, Ferris BL, Polissar N, Neradilek B, Pepper D. Endo- changes at the saphenofemoral junction and in the long venous laser treatment of the short saphenous vein: efficacy saphenous vein during the first year after VNUS closure. Int and complications. J Vasc Surg 2007;45(4):795e803. Angiol 2002;21(3):272e4. 26 Merchant Jr R, Kistner RL, Kabnick LS. Is there an increased risk for 8 Bacon JL, Dinneen AJ, Marsh P, Holdstock JM, Price BA, DVT with the VNUS closure procedure? J Vasc Surg 2003;38(3):628. Whiteley MS. Five-year results of incompetent perforator vein 27 US FDA manufacturer user facility device experience (MAUDE) closure using TRans-Luminal Occlusion of Perforator. Phle- database [cited 05.07.07]. Available from: www.accessdata. bology 2009;24(2):74e8. fda.gov/scripts/cdrh/cfdocs/cfMAUDE. 9 Whiteley MS, Lewis G, Holdstock JM, Smith C, Harrisone CS, 28 Bounameaux H, Huber O. Postoperative deep vein thrombosis McGuinness CL, et al. Minimally invasive technique for ligation and surgery for varicose veins. BMJ (Clinical Research ed) 1996; and stripping of the small saphenous vein guided by intra- 312(7039):1158. operative duplex ultrasound. Surgeon 2006;4(6):372e3. 5e7. 29 Proebstle TM, Pannier FM, Schuller-Petrovic S, Offerman M, 10 Klein JA. Anesthesia for liposuction in dermatologic surgery. Hohenleutner U, Rabe E. Konsensus zur endovenoesen Laser- J Dermatol Surg Oncol 1988;14(10):1124e32. therapie der Varikose. Phlebologie 2004;33:106e9.