Case of the Disappearing Heat-Induced Thrombus Causing Pulmonary Embolism During Ultrasound Evaluation

Case of the disappearing heat-induced thrombus causing pulmonary embolism during ultrasound evaluation

Shekeeb Suﬁan, MD, Alejandro Arnez, MD, and Sanjiv Lakhanpal, MD, Glenn Dale, Md

We report a case of a 58-year-old male patient who underwent successful endovenous radiofrequency ablation of the left great saphenous vein for CEAP class 4a venous disease. On the third postoperative day, he had a duplex ultrasound scan for evaluation which showed successful occlusion of the great saphenous vein (GSV) with class 2 endovenous heat- induced thrombus (EHIT) that disappeared during the evaluation and caused a pulmonary embolism. To our knowledge, no case of pulmonary embolism has been reported to occur during postoperative follow-up duplex scanning. Relevant literature is reviewed and a possible mechanism for thrombus dislodgement is entertained. (J Vasc Surg 2012;55: 529-31.)

Endovenous thermal ablation of the saphenous veins blood pressure was 110 over 68, his pulse rate was 82/minute, and using radiofrequency ablation (RFA) or endovenous laser his respiratory rate was 16/minute. The general physical examina- ablation has become the most common method of treat- tion was essentially negative. The right leg had no evidence of ment for varicose veins and symptomatic venous reflux varicose veins or stigmata of venous insufficiency. On the left leg, disease, and is getting wide acceptance.1,2 Minor compli- there was an area of skin hyperpigmentation in the distal medial cations such as skin bruising/hematoma, bleeding, tran- calf. There were also obvious varicosities in the medial and poste- sient paresthesias, and skin burns have been reported in 3% rior calf regions. His CEAP class was 4a and the Venous Clinical to 20% of patients.3 Major complications which include Severity Score was 6. The patient used compression stockings in deep venous thrombosis (DVT) and pulmonary embolism the past for about 3 months without significant improvement. (PE) are rare. Extension of thrombus from the saphenous Duplex ultrasound scan evaluation was performed in our to the femoral or popliteal veins have been reported to Intersocietal Commission for the Accreditation of Vascular Labo- occur in 0% to 6% of patients.4 The term endovenous ratories which showed reflux in the left great saphenous vein (GSV) heat-induced thrombus (EHIT) was introduced by Kab- with a maximum reflux of 3.5 seconds near the confluence of the nick4 who also classified the level of thrombus from 1 to 4 saphenous vein. The maximum diameter of the GSV was 11 mm classes.4 Hingorani et al5 reported extension of thrombus above the knee and 5 mm below the knee. The deep veins were all in 16% of limbs treated with RFA, and raised caution about normal. The patient underwent RFA of the left GSV using Clo- the procedure and recommended early postoperative du- sureFAST (VNUS MEDICAL Technologies Inc, San Jose, Calif) plex scan evaluation. Most of these thrombi retract or in a standard technique, with the head down position using tumes- absorb, but they theoretically can also detach and cause cent anesthesia totaling 290 mL. The vein was accessed below the a PE. knee. The catheter tip was 2.8 cm from the saphenofemoral junction and 2.3 cm from the superficial epigastic vein. No pro- CASE REPORT phylactic anticoagulation or aspirin was given to the patient. Post- A 58-year-old man was referred to our office by his primary operatively, the patient was active and walking, and used elastic physician with symptoms of left calf pain and progressive edema stockings. The patient was re-evaluated 3 days later in our vascular which had gradually gotten worse over the previous 3 months. The laboratory, and the GSV was noted to be completely occluded. symptoms were more prominent at the end of the day. There was There was EHIT class 2 in the left saphenofemoral junction. The no family history of thrombophilia and his medical history was common femoral vein was compressible and had flow but there was negative. He had no history of DVT and no history of smoking. He thrombus protruding into the lumen filling Ͻ50% of the lumen was taking no medications. On examination, his weight was 134 (Fig 1). There was no loose tail or floating thrombus. The evalu- pounds, height was 5=6Љ, with a body mass index of 21.63. His ation was done in a routine fashion and no excessive compression was used. When the saphenofemoral region was re-evaluated after From the Center for Vein Restoration. the compression test, the thrombus, which was protruding into the Competition of interest: none. femoral vein, disappeared (Fig 2). The patient was immediately Reprint requests: Shekeeb Sufian, MD, Center for Vein Restoration, 12200 Annapolis Road, Suite 225, Glenn Dale, MD 20769 (e-mail: shekeeb. referred to the hospital for PE workup. A computed tomography sufi[email protected]). (CT) scan of the chest with contrast was obtained. This was The editors and reviewers of this article have no relevant financial relationships positive for acute bilateral small segmental pulmonary emboli (Fig to disclose per the JVS policy that requires reviewers to decline review of any 3). The patient had no symptoms of cough, chest pain, or shortness manuscript for which they may have a competition of interest. of breath. His vital signs were normal except for a heart rate of 116. 0741-5214/$36.00 Copyright © 2012 by the Society for Vascular Surgery. The pulse oximetry was 100% on room air. He was admitted to the doi:10.1016/j.jvs.2011.07.070 hospital and treated with enoxaparin sodium (lovenox) 1 mg/kg 529 JOURNAL OF VASCULAR SURGERY 530 Sufian et al February 2012

Fig 3. Computed tomography (CT) of the chest showing acute bilateral small segmental pulmonary emboli.

until the international normalized ratio (INR) was therapeutic. He was discharged from the hospital after 3 days on 7.5 mg of warfarin Fig 1. Duplex ultrasound scan of the left saphenofemoral junc- daily by mouth and followed as an out-patient. Follow-up duplex tion (SFJ) with thrombus protruding from the great saphenous scans done after 1 week, 1 month, 2 months, and 6 months showed vein (GSV) into the common femoral vein (CFV) (endovenous no evidence of DVT and the GSV remained occluded. The oral heat-induced thrombus [EHIT] class 2). anticoagulation was discontinued after 4 months. The Venous Clinical Severity Score improved from 6 to 4.

DISCUSSION DVT and PE are rare complication of EHIT. Kabnick4 introduced the term EHIT and noted that this is more benign than the spontaneously occurring thrombosis, in that it is stable and usually regresses or shows complete resolution. He also made the observation that EHIT dis- plays a different sonographic echogenicity and becomes echogenic in Ͻ24 hours. The EHIT in our case does show increased echogenicity. He classified EHIT from class 1 to class 4. Another classification system was recently introduced by Lawrence et al6 from level 1 to 6. The Interna- tional Endovascular Working Group registry shows that DVT/EHIT occurred in 0.27% (10 of 3696 cases) and PE occurred in 0.023% (1 of 3696) after endovenous laser ablation.4 In a review of 11 articles, Mozes et al7 reported 21 case of DVT and 2 cases of PE after the VNUS Closure (VNUS MEDICAL Technologies Inc) procedure.7 At the Arizona Heart Institute, with Ͼ1000 cases of venous ablation, only 1 case of pulmonary embolism was reported.8 To decrease the risk of EHIT formation, several suggestions have been offered: the position of the catheter tip should be Fig 2. Duplex ultrasound scan of the saphenofemoral junction (SFJ) at least 2 cm from the saphenofemoral or saphenopopliteal after compression, showing disappearance of thrombus from the com- junction, reduce the thrombus load by elevation of the leg mon femoral vein (CFV) and distal great saphenous vein (GSV). during ablation, and also by using adequate tumescent anesthesia.7 A recent article showed that a GSV diameter of Ͼ8 mm and history of DVT were associated with EHIT subcutaneously twice a day and then converted to warfarin. The class 2 or greater.6 But another study which evaluated the admission was made necessary because he could not be treated as influence of procedural factors concluded that there was no an outpatient over the weekend. The enoxaparin was continued difference in catheter tip position or mean diameter of the JOURNAL OF VASCULAR SURGERY Volume 55, Number 2 Sufian et al 531

treated vein between the EHIT and non-EHIT groups.9 blinded, randomized study (RECOVERY Study). J Vasc Interv Radiol There is no report on association of EHIT with hyperco- 2009;20:752-9. agulable states. 2. Lurie F, Creton D, Eklof B, Kabnick LS, Kistner RL, Pichot O, et al. Prospective randomised study of endovenous radiofrequency oblitera- Our patient had no history of DVT or family history of tion (closure) versus ligation and vein stripping (EVOLVeS): two-year thrombophilia, and the catheter tip was definitely identified follow-up. Eur J Vasc Endovasc Surg 2005;29:67-73. at 2.8 cm from the saphenofemoral junction and 2.3 cm 3. Merchant RF, Pichot O, Closure Study Group. Long-term outcomes of from the superficial epigastic vein. The diameter of his GSV endovenous radiofrequency obliteration of saphenous reflux as a treatment for superficial venous insufficiency. J Vasc Surg 2005;42:502-9; was 11 mm, which may have contributed to the EHIT. We discussion 509. hypothesize that the standard technique of compression of 4. Kabnick LS. Complications of endovenous therapies: statistics and the superficial and deep veins10 used to evaluate for DVT at treatment. Vascular 2006;14:S31-32. the saphenofemoral junction may have contributed to the 5. Hingorani AP, Ascher E, Markevich N, Schutzer RW, Kallakuri S, Hou dislodgement of the thrombus causing PE. To our knowl- A, et al. Deep venous thrombosis after radiofrequency ablation of greater saphenous vein: a word of caution. J Vasc Surg 2004;40:500-4. edge, there has been no report of PE caused during ultra- 6. Lawrence PF, Chandra A, Wu M, Rigberg D, DeRubertis B, Gelabert sound scan evaluation of EHIT. H, et al. Classification of proximal endovenous closure levels and We recommend that when thrombus protrusion into treatment algorithm. J Vasc Surg 2010;52:388-93. the femoral or popliteal vein is observed after endovenous 7. Mozes G, Kalra M, Carmo M, Swenson L, Gloviczki P. Extension of saphenous thrombus into the femoral vein: a potential complication of ablation, one should not use compression of the femoral new endovenous ablation techniques. J Vasc Surg 2005;41:130-5. vein, to avoid dislodgement and possible PE. Instead, a 8. Ravi R, Rodriguez-Lopez J, Ramaiah V, Diethrich EB. Regarding Valsalva maneuver should suffice. The treatment of asymp- “Extension of saphenous thrombus into the femoral vein: a potential tomatic PE after venous ablation is controversial, but it may complication of new endovenous ablation techniques.” J Vasc Surg not be necessary when the thrombus load is small. Further 2005;42:182; author reply 182-3. 9. Rhee SJ, Stoughton J, Cantelmo NL. Procedural factors influencing the clinical study is needed to clarify this point. incidence of endovenous heat induced thrombosis (EHIT). J Vasc Surg 2011;53:555. 10. Raghavendra BN, Horii SC, Hilton S, Subramanyam BR, Rosen RJ, REFERENCES Lam S. Deep venous thrombosis: detection by probe compression of 1. Almeida JI, Kaufman J, Göckeritz O, Copra P, Evans MT, Hoheim DF, veins. J Ultrasound Med 1986;5:89-95. et al. Radiofrequency endovenous Closure FAST versus laser ablation for the treatment of great saphenous reflux: a multicenter, single- Submitted May 25, 2011; accepted Jul 13, 2011.