Iliofemoral stenting for venous occlusive disease

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1 From the Society for Vascular Surgery Iliofemoral stenting for venous occlusive disease Jessica M. Titus, MD, Mireille A. Moise, MD, James Bena, MS, Sean P. Lyden, MD, and Daniel G. Clair, MD, Cleveland, Ohio Background: Venous hypertension is a significant cause of patient morbidity and decreased quality of life. Common etiologies of venous hypertension include deep venous thrombosis (DVT) or congenital abnormalities resulting in chronic outflow obstruction. We have implemented an aggressive endovascular approach for the treatment of iliac venous occlusion with angioplasty and stenting. The purpose of this study was to determine the patency rates with this approach at a large tertiary care center. Materials/Methods: All patients undergoing iliofemoral venous angioplasty and stenting over a 4-year period were identified from a vascular surgical registry. Charts were reviewed retrospectively for patient demographics, the extent of venous system involvement, the time course of the venous pathology, and any underlying cause. Technical aspects of the procedure including previous angioplasty or stenting attempts and presence of collaterals on completion venogram were then recorded. Patency upon follow-up was determined using primarily ultrasound scans; other imaging methods were used if patency was not clear using an ultrasound scan. Results: A total of 36 patients (40 limbs) were stented from January 2005 through December Of these patients, 27 were women (75%). Both lower extremities were involved in 4 patients. Thrombolysis was performed in 19 patients (52.8%). Thrombosis was considered acute (<30 days) in 13 patients (38%). The majority of patients who had a recognized underlying etiology were diagnosed with May-Thurner syndrome (15 patients; 42%). In 9 patients, an etiology was not determined (25%). The mean follow-up time period in the study population was 10.5 months. One stent in the study occluded acutely and required restenting. Primary patency rates at 6, 12, and 24 months were 88% ( ), 78.3% ( ), and 78.3% ( ), respectively. Secondary patency rates for the same time frames were 100% (100.0, 100.0), 95% (85.4, 100.0), and 95% (85.4, 100.0). Better outcomes were seen in stenting for May-Thurner syndrome and idiopathic causes, whereas external compression and thrombophilia seemed to portend less favorable outcomes (P <.001). Symptomatic improvement was reported in 24 of 29 patients (83%) contacted by telephone follow-up. Conclusion: Iliofemoral venous stenting provides a safe and effective option for the treatment of iliac venous occlusive disease. Acceptable patency rates can be expected through short-term follow-up, especially in the case of May-Thurner syndrome. Further experience with this approach and longer-term follow-up is necessary. Thrombophilia workup should be pursued aggressively in this population, and further studies should be undertaken to determine the optimal length of anticoagulation therapy after stent placement. (J Vasc Surg 2011;53: ) Venous outflow obstruction can lead to ambulatory venous hypertension and chronic venous insufficiency. 1-5 The symptoms of chronic venous insufficiency including ulcerations, chronic pain, and/or swelling, are a significant cause of morbidity and decreased quality of life for patients. Their treatment represents a large amount of health care expenditure, estimated at over 1 billion dollars per year. 6 Common causes of outflow obstruction include acute deep venous thrombosis (DVT) and extrinsic compression of the iliac vein. Chronic outflow obstruction after an episode of acute DVT manifests itself as a constellation of symptoms known as the postthrombotic syndrome (PTS). This includes From the Department of Vascular Surgery, Cleveland Clinic Foundation. Competition of interest: none. Presented as a poster at 2009 Vascular Annual Meeting of the Society of Vascular Surgery, June 2009, Denver, Colo. Reprint requests: Jessica M. Titus, MD, Cleveland Clinic Foundation, Department of Vascular Surgery, H32, 9500 Euclid Ave, Cleveland, OH ( titusj@ccf.org). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a competition of interest /$36.00 Copyright 2011 by the Society for Vascular Surgery. doi: /j.jvs symptoms of persistent pain, swelling, skin changes, and ulceration. As many as 29% to 82% of patients will develop PTS after an episode of DVT These symptoms are thought to result from the chronic outflow obstruction after thrombosis and occlusion of the venous lumen. During this process, inflammatory changes take place that can result in vein wall fibrosis, leading to valve dysfunction, reflux, and insufficiency. 8,11 Studies have shown that early thrombus removal and decreasing the incidence of recurrent thrombotic events can reduce the likelihood of developing PTS Chronic outflow obstruction can also result from extrinsic forces compressing the iliac vein. These include entities such as May-Thurner syndrome (compression of the left iliac vein from an overriding right common iliac artery) or pelvic tumors, fluid collections, or fibrosis. Regardless of the cause, interventional treatment of outflow obstruction in the form of angioplasty and stenting has been shown to relieve symptoms and improve quality of life It has also been found to have comparable if not better patency rates than the currently available open surgical alternatives (bypass). 20,21 Factors affecting stent patency rates still have not been clearly delineated. The purpose of this article is to evaluate the iliofemoral venous

2 JOURNAL OF VASCULAR SURGERY Volume 53, Number 3 Titus et al 707 stenting experience in our institution and review different technical and clinical factors in an effort to clarify risk factors for stent thrombosis. MATERIALS AND METHODS Patient factors. From January 2005 to December 2008, 36 patients were treated with venous stenting for symptomatic iliofemoral occlusive disease. The majority of these patients were treated within the main campus of the institution, which serves as a large tertiary care center for the region. A small number of patients were treated at satellite sites, and these were also included in the study. Both patients who presented acutely and those whose disease was chronic were included in this study. In addition, patients who had their initial stent placed at another hospital and subsequently presented to our institution after stent thrombosis for further care were included, provided that they required additional stenting. Those who did not require further stenting were not included. All patients were studied with duplex ultrasound scans before their operation to identify the extent of the thrombosis. The patients medical charts were reviewed for demographic data, significant medical history, the extent of the thrombosis, clinical factors, technical aspects of the surgery, postoperative complications, and follow-up visits. Significant medical history was divided into categories of significant comorbidities including coronary artery disease, chronic obstructive pulmonary disease, and renal disease. Other factors recorded were current tobacco use, use of exogenous hormones (OCPs), and a history of thrombophilia, malignancy, or prior vena cava filter placement. Thrombophilia workup was performed selectively based on surgeon evaluation for necessity. Other history reviewed was initial treatments at another hospital and history of a previous angioplasty attempt. Extent of the thrombosis was judged according to preoperative ultrasound scans and intraoperative venography findings. Clinical factors included clinical severity and time course of symptoms. Clinical severity was documented according to the CEAP classification before the procedure. Etiology of the patient s DVT was determined based on patient history, findings in the preoperative workup, and intraoperative data. These were divided into 4 classes: May- Thurner syndrome, external compression from another source, thrombophilia, and idiopathic/unknown DVT. The disease was considered acute if symptoms had been present for 30 days. Technical aspects recorded from the surgery were the use of intravascular ultrasound (IVUS) scan, number and size of stents used, location of stent placement, use of thrombolysis, and concurrent filter placement. In addition, postoperative complications were recorded. Length of follow-up was determined by the last imaging of the stent. Stent patency was recorded by date of loss of primary, primary-assisted, or secondary patency. Procedure. Access was gained proximal to the level of the obstruction from a venous flow standpoint. This was the popliteal vein in the majority of the patients (20 patients). Femoral access was used in 13 patients, and 3 patients had a combined femoral/jugular approach. Venography was then performed to discern the extent of the thrombosis or obstruction. In all patients, balloon angioplasty was attempted before stents were placed. After angioplasty, the presence of recoil or persistent obstruction prompted the use of stents. A variety of nitinol self-expanding stents were used in the majority of patients, and size was based on the vessel in which it was deployed. Two patients had steel self-expanding stents placed. Median stent diameter was 14 mm (range, 9-28). Completion venography was then obtained to identify the presence of persistent collaterals or the need for further stenting. Fig 1 shows a representative ultrasound scan and venograms. Inferior vena cava (IVC) filter placement was used selectively in patients who were felt to be at a very high risk for pulmonary embolus based on individual surgeon assessment. In these cases, retrievable filters were used. Postoperatively, all patients were started or continued on anticoagulation therapy with warfarin (goal-international normalized ratio 2-3) or Lovenox for at least 6 months. Follow-up imaging was primarily done with duplex ultrasound scan. A small number of patients were reimaged with computed tomography, magnetic resonance imaging, and/or repeat venography because of difficulty obtaining adequate imaging of the stents by ultrasound scan alone. No follow-up data were available for 3 patients. Patients were contacted by telephone at the time of this study. They were asked about their overall current symptoms, their edema on an average day, and if they had undergone any subsequent operations with respect to their venous occlusive disease. Statistical methods. Data were summarized using frequencies and percentages for categorical factors and mean, SD, and percentiles of interest for continuous measures. For purposes of analysis, the number of stents was reduced to 1, 2, and 3 or more. The stent size was evaluated as the maximum diameter. Measures of patency at 6 months, 1 year, and 2 years, were calculated using Kaplan- Meier estimation. Estimates and comparisons of risk across groups defined by baseline characteristics were evaluated using Cox proportional hazards models. Statistical analysis was performed using SAS software (version 9; Cary, NC), and plots were created using R Software (version 2; Vienna, Austria). A significance level of 0.05 was assumed for all tests. RESULTS During the time period listed, 88 iliofemoral venous angioplasties were performed. Of these, 36 patients underwent lower extremity venous stenting for occlusive disease. In total, 40 limbs were stented, as 4 patients (11%) had bilateral lower extremity involvement. Of these patients, 27 were women (75%). The average age was 45.6 years old (range, 17-73). The occlusion was considered acute in 14 of those patients (39%) presenting for treatment. In the categories of defined etiology of the occlusion (Fig 2), 15

3 708 Titus et al JOURNAL OF VASCULAR SURGERY March 2011 Fig 1. Ultrasound scans and venograms of a 49-year-old female smoker who presented with chronic left lower extremity swelling and pain. A, Initial ultrasound scan shows noncompression (left) and compression (right) views of left external iliac vein. B, Initial venogram shows stenoses of left common femoral vein and iliac system with filling of inferior vena cava (IVC) mainly through cross-pelvic collaterals. C, Collateral filling persisted on the postangioplasty films, and residual stenosis was noted as well. D, Poststent venogram shows resolution of collateral filling with good flow through the femoral and iliac system into the IVC. patients had May-Thurner syndrome (41.7%), 9 patients had an idiopathic/unknown cause (25%), 7 patients had external compression (19.4%), and 5 patients (13.9%) had a known underlying thrombophilia. Of those in the external compression category, 2 patients had postoperative lymphoceles after pelvic lymph node dissections for prostate cancer, 1 patient had retroperitoneal fibrosis, and 4 patients had malignancy-related compression. Of these 4 patients, 3 had mass effect from enlarged lymph nodes from testicular, prostate, or cervical cancer, and 1 had direct compression from a large sarcoma. In 14 patients (39%), thrombophilia workup was performed resulting in eight positive findings (22% of study patients, 57% of those checked). Of those positive findings, 4 patients had factor V Leiden heterozygosity, 2 patients had lupus anticoagulant, 2 patients were positive for prothrombin 20210A mutation, and 2 patients were found to have MTHFR factor II mutation. One of these patients had both factor V Leiden and lupus anticoagulant, and another had both a prothrombin gene mutation and factor V Leiden. Medical history and other demographic factors are shown in Table I. Mean CEAP clinical severity score on initial presentation was Actual distribution of the classes can be seen in Table II. Five patients (13.9%) had been seen and treated with stenting at another institution, and 9 patients (25%) had IVC filters placed before being seen by a vascular surgeon in our department. In this study, 12 patients (33%) had a previous angioplasty attempt (at either our institution or another hospital) that had failed. Clot burden was isolated to the left side in 24 patients (66.7%), the right side in 7 patients (19.4%), and bilateral in 4 patients (11%). IVC involvement was noted in 12 patients (33%), femoral veins were occluded in 26 patients (19 left, 6 right, and 1 bilateral),

4 JOURNAL OF VASCULAR SURGERY Volume 53, Number 3 Titus et al 709 Fig 2. Underlying etiology of venous occlusion. Table I. Demographic and comorbidities of patient population Demographic/comorbidity No. (%) CAD 7 (19%) COPD 3 (8%) Renal disease 2 (6%) Current smoker 9 (25%) Thrombophilia workup 14 (39%) Positive 8 (22%) Negative 6 (17%) Acute disease 14 (39%) Initial stent at other institution 5 (14%) On anticoagulation 23 (64%) CAD, Coronary artery disease; COPD, chronic obstructive pulmonary disease. Table II. CEAP clinical severity score comparison at presentation and follow-up poststent Presentation CEAP clinical severity score Follow-up Score No. (%) Score No. (%) (33%) 2 2 (6%) 2 2 (6%) 3 25 (69%) 3 19 (53%) 4 8 (22%) (3%) 6 1 (3%) 6 0 and the clot extended down to the popliteal vessel in 14 patients (38.9%). Initial thrombolysis was done in 19 patients (52.8%), which took place for 12 to 72 hours. Three of the 19 patients had residual clot present at the cessation of thrombolysis. In all, 73 stents were placed in 40 limbs. The largest number of stents in 1 patient was seven. One stent was placed in each of 13 patients (36.1%), 2 stents were placed in each of 14 patients (38.9%), and 3 stents were placed in each of 9 patients (25%). Stent placement involved the left common iliac in 24 patients, right common iliac in 6 patients, and bilateral common iliacs in 3 patients. Left, right, and bilateral external iliacs were stented in 19, 4, and 2 patients, respectively. In 20% of the patients, the femoral vein was also stented. IVUS was used in 10 cases (27.7%). Nine patients had previously placed IVC filters from other institutions; two of these were removed. Of the two IVC filters placed by our surgeons, one was removed with the patient being lost to follow-up before the filter could be removed. Postoperatively, one stent had early thrombosis and required acute reoperation. Otherwise, there were no complications associated with the stenting; no incidences of pulmonary embolus were recorded and no bleeding complications were noted. Primary patency rates (shown in Fig 3) at 6, 12, and 24 months were 88% ( ), 78.3% ( ), and 78.3% ( ), respectively. Secondary patency rates for the same time frames were 100% (100.0, 100.0), 95% (85.4, 100.0), and 95% (85.4, 100.0), respectively. Mean follow-up time was 10.5 months with a range of 0 to 38 months. At follow-up, mean CEAP clinical severity score had decreased to One patient in this study had venous ulceration preoperatively; upon followup, this had healed.

5 710 Titus et al JOURNAL OF VASCULAR SURGERY March 2011 Fig 3. In-graph patency estimates for the entire cohort are provided. Kaplan-Meier estimates of primary, assisted primary, and secondary patency are provided with 95% confidence intervals in parentheses are shown below. Measures Frequency Events 6 months 12 months 24 months Primary ( ) 78.3 ( ) 78.3 ( ) patency Assisted primary patency ( ) 82.7 ( ) 82.7 ( ) Secondary patency ( ) 95.0 ( ) 95.0 ( ) With regard to risk factors for in-stent stenosis or rethrombosis, only etiology of the obstruction was determined to be a statistically significant factor (Table III). Patients with external compression or associated thrombophilia were more likely to have a worse outcome than those with May-Thurner syndrome or idiopathic occlusion (P.001). Other variables measured that were not determined to be statistically significant were stent placement in the femoral system, stent diameter, stent placement into the IVC, the use of IVUS scan, number of stents, and acutevs-chronic disease presentation. On telephone call follow-up, 29 patients were reached. Three patients had expired and 4 patients were unavailable. All patients who were contacted elected to participate in this study. Of these 29 patients, 24 (83%) reported an overall improvement in their symptoms because they had undergone stenting. Two patients reported that their symptoms had not changed (7%), and 3 patients stated that their symptoms had become progressively worse (10%). With respect to edema, 7 patients (24%) rated it as none, 11 patients (40%) as mild, 8 patients (28%) as moderate, and 3 patients (10%) as severe. DISCUSSION Results from this small retrospective study show that excellent patency rates and symptomatic improvement can be obtained with stenting for venous outflow occlusion. Our primary and secondary patency rates at 2 years of 78% and 95%, respectively, are comparable to those found by previous studies. 17,22-25 Primary patency was lost in 5 patients at mean follow-up of 10 months, all but one of these stents were able to be reopened. In the last patient, another operation was refused by the patient and actually not recommended by the surgeon, as the patient s symptoms of edema, claudication, and skin changes were improving. Other studies have divided the etiologies into thrombotic and nonthrombotic disease, but to our knowledge, no study has looked at the different causes of thrombotic disease to discern its effect on stent outcome. This study showed a worse outcome with etiologic factors of diagnosed thrombophilia and external compression as opposed to May-Thurner syndrome or idiopathic causes. Of the stents that lost primary patency, 2 patients had diagnosed thrombophilia and 3 had external compression as the underlying etiologies. Two of the patients in the external compression group occluded their stents within a month of being taken off their anticoagulation. One of the 2 patients was subsequently found to have an underlying thrombophilia. Once anticoagulation was restarted, there were no further problems. This brings forward the question of how long to continue anticoagulation in people with venous stents and whether to pursue a hypercoagulable workup more frequently in this patient population. Limitations of the study were the small patient size and limited follow-up. Venous stenting is becoming more commonplace at our institution and with education of other specialists and primary care physicians, referrals should increase and allow us to gain better information with a larger patient pool. In addition, within our department, we have begun to implement specific guidelines for standard follow-up of these patients concerning office visits and imaging. This should ensure better follow-up. The small number of events of stent occlusion in the study also made it difficult to determine any statistically significant risk factors for stent occlusion. This highlights the need for additional studies, possibly multicenter with larger numbers of patients. Interestingly, all but 1 of the patients in this study were referred or seen for symptoms associated with current clot burden. Only 1 patient wasreferred solely for PTS evaluation. Studies have shown that PTS symptoms can be improved with stenting, as they usually have at least partial outflow occlusion and associated venous hypertension. The referral findings in this study highlight the need for education of other health professionals in this institution, as there are likely more patients that can be helped with this therapy. In summary, the results of this study indicate that venous stenting for iliofemoral occlusive disease is a safe and effective method of treatment. It can be done with excellent patency rates expected in cases of idiopathic occlusion and May-Thurner syndrome. However, in cases in which external compression or inherent thrombophilia is the cause of the underlying occlusion, poorer outcomes can be expected. Relief of patient symptoms continues to be the main goal of treatment. Venous stenting has been shown

6 JOURNAL OF VASCULAR SURGERY Volume 53, Number 3 Titus et al 711 Table III. Kaplan-Meier estimate of primary patency and hazard ratios from Cox proportional hazards models are shown by group defined by baseline measures Variable Levels Subjects 6 months 12 months 24 months Hazard ratio (95% CI) Overall Number of ( ) 68.2 ( ) 68.2 ( ) stents ( ) 87.5 ( ) 87.5 ( ) 0.37 ( ) ( ) 83.3 ( ) 83.3 ( ) 0.50 ( ) IVC No ( ) 78.0 ( ) 78.0 ( ) Yes ( ) 75.0 ( ) 75.0 ( ) 0.78 ( ). Etiology May-Thurner ( ) ( ) ( ) External ( ) 27.8 ( ) NA NA Thrombophilia ( ) 50.0 ( ) 50.0 ( ) NA Other/unknown ( ) ( ) NA NA IVUS No ( ) 84.0 ( ) 84.0 ( ) Common femoral Yes ( ) 53.3 ( ) 53.3 ( ) 2.79 ( ) No ( ) 83.3 ( ) 83.3 ( ) Yes ( ) 75.7 ( ) 75.7 ( ) 1.55 ( ) Acute No ( ) 79.4 ( ) 79.4 ( ) Yes ( ) 75.8 ( ) N/A 1.39 ( ) Max. stent diameter Sum stent length ( ) 0.51 a ( ) 0.65 a IVC, Inferior vena cava; IVUS, intravascular ultrasound; N/A, not applicable; Max., maximum. The P value is from the log-rank test except for continuous measures ( a ) in which the test of the hazard ratio was used. in this study to be a very good means of achieving that goal. In addition, perhaps a more aggressive approach toward hypercoagulability assessment should be pursued in this patient population and studies to determine the optimal duration of anticoagulation therapy after venous stenting are needed. AUTHOR CONTRIBUTIONS Conception and design: JT, MM, JB, SL, DC Analysis and interpretation: JT, JB, DC Data collection: JT, MM Writing the article: JT, MM, DC Critical revision of the article: DC, SL Final approval of the article: JT, DC, SL Statistical analysis: JB Obtained funding: JT, DC Overall responsibility: JT, DC REFERENCES 1. Burnand KG. The physiology and hemodynamics of chronic venous insufficiency of the lower limb. In: Bloviczki P, Yao JST, editors. Handbook of venous disorders. Guidelines of the American Venous Forum. 2nd ed. London: Arnold; pp Johnson BF, Manzo RA, Bergelin RO, Strandness DE Jr. Relationship between changes in the deep venous system and the development of the post-thrombotic syndrome after an acute episode of lower limb deep vein thrombosis: a one- to six-year follow-up. J Vasc Surg 1995;21:207-12; discussion Barnes RW, Collicott PE, Sumner DS, Strandness DE Jr. Noninvasive quantitation of venous hemodynamics in the postphlebitic syndrome. Arch Surg 1973;107: Markel A, Manzo RA, Bergelin RO, Strandness DE Jr. Valvular reflux after deep vein thrombosis: incidence and time of occurrence. J Vasc Surg 1992;15:377-82; discussion Meissner MH, Moneta G, Burnand K, Gloviczki P, Lohr JM, Lurie F, et al. The hemodynamics and diagnoses of venous disease. J Vasc Surg 2007;46 Suppl S:4S-24S. 6. US Department of Health and Welfare. The magnitude of chronic disease problems in the United States. National Health Survey Preliminary Reports. Washington, DC; Lindner DJ, Edwards JM, Phinney ES, Taylor LM Jr, Proter JM. Long-term hemodynamic and clinical sequelae of lower extremity deep vein thrombosis. J Vasc Surg 1986;4: Meissner MH, Wakefield TW, Ascher E, Caprini JA, Comerota AJ, Eklot B, et al. Acute venous disease: venous thrombosis and venous trauma. J Vasc Surg 2007;4]?(6 Suppl S):25S-53S/sb:comment 9. Strandness DE Jr, Langlois Y, Cramer M, Randlett A, Thiele BL. Long-term sequelae of acute deep vein thrombosis. JAMA 1983;250: Kahn SR. The post-thrombotic syndrome: the forgotten morbidity of deep vein thrombosis. J Thromb Thrombolysis 2006;21: Sevitt S. The mechanisms of canalisation in deep vein thrombosis. J Pathol 1973;110: Messner MH, Caps MT, Bergelin RO, Manzo RA, Strandness DE Jr. Propagation, rethrombosis and new thrombus formation after acute deep venous thrombosis. J Vasc Surg 1995;22: Beyth RJ, Cohen AM, Landefeld CS. Long-term outcomes of deepvein thrombosis. Arch Intern Med 1995;155: Plate G, Eklöf B, Norgren L, Ohlin P, Dahlstrom JA. Venous thrombectomy for iliofemoral vein thrombosis 10-year results of a prospective randomised study. Eur J Vasc Endovasc Surg 1997;14: Comerota AJ, Katz ML, White JV. Thrombolytic therapy for acute deep venous thrombosis: how much is enough? Cardiovasc 1996;4: Elsharawy M, Elzayat E. Early results of thrombolysis vs anticoagulation in iliofemoral venous thrombosis. A randomised clinical trial. Eur J Vasc Endovasc Surg 2002;24: Hartung O, Otero A, Boufi M, Decaridi G, Barthelemy P, Juhan C, Alimi YS. Mid-term results of endovascular treatment for symptomatic chronic nonmalignant iliocaval venous occlusive disease. J Vasc Surg 2005;42: ; discussion 1144.

7 712 Titus et al JOURNAL OF VASCULAR SURGERY March Neglen P, Raju S. Endovascular treatment of chronic occlusions of the iliac veins and the inferior vena cava. In: Rutherford RB, editor. Vascular Surgery. 6th ed. Philadelphia: Elsevier Saunders; pp Raju S, Owen S Jr, Neglen P. The clinical impact of iliac venous stents in the management of chronic venous insufficiency. J Vasc Surg 2002; 35: Gloviczki P, Delis KT, Bjarnason H. Endovascular treatment for major vein occlusion. In: Pearce WH, Matsumura JS, Yao JS, editors. Trends in vascular surgery. Evanston, (IL): Greenwood Academic; pp Jost CJ, Gloviczki P, Cherry KJ Jr, McKusick MA, Harmsen WS, Jenkins GD, Bower TC. Surgical reconstruction of iliofemoral veins and the inferior vena cava for nonmalignant occlusive disease. J Vasc Surg 2001;33:320-7; discussion Husmann MJ, Heller G, Kalka H, Savolainen H, Do DD, Schmidli J, Baumgartner I. Stenting of common iliac vein obstructions combined with regional thrombolysis and thrombectomy in acute deep vein thrombosis. Eur J Vasc Endovasc Surg 2007;34: Kölbel T, Lindh M, Holst J, Uher P, Eriksson KF, Sonesson B, et al. Extensive acute deep vein thrombosis of the iliocaval segment: midterm results of thrombolysis and stent placement. J Vasc Interv Radiol 2007;18: Kwak HS, Han YM, Lee YS, Jin GY, Chung GH. Stents in common iliac vein obstruction with acute ipsilateral deep venous thrombosis: early and late results. J Vasc Interv Radiol 2005;16: Neglén P, Hollis KC, Olivier J, Raju S. Stenting of the venous outflow in chronic venous disease: long-term stent-related outcome, clinical, and hemodynamic result. J Vasc Surg 2007;46: Submitted Jun 7, 2010; accepted Sep 2, REQUEST FOR SUBMISSION OF SURGICAL ETHICS CHALLENGES ARTICLES The Editors invite submission of original articles for the Surgical Ethics Challenges section, following the general format established by Dr. James Jones in Readers have benefitted greatly from Dr. Jones monthly ethics contributions for more than 6 years. In order to encourage contributions, Dr. Jones will assist in editing them and will submit his own articles every other month, to provide opportunity for others. Please submit articles under the heading of Ethics using Editorial Manager, and follow the format established in previous issues.