- Email: [email protected]
Endovascular Strategy for Recanalization of Long-Segment Central Vein Occlusion With Concomitant Arteriovenous Fistula Creation
Endovascular Strategy for Recanalization of Long-Segment Central Vein Occlusion With Concomitant Arteriovenous Fistula Creation Rafael D. Malgor, Emily A. Wood, Antonios P. Gasparis, and Mazen Hashisho, Stony Brook, New York
Recanalization of long-segment central vein flush occlusion in hemodialysis patients has been advocated in lieu of central vein bypass and thoracotomy to restore arteriovenous access availability. We report a challenging case of complex central venous flush occlusion in a 50-year-old woman on hemodialysis who presented with right arm and facial swelling. A concise step-bystep description of endovascular strategy with retrograde and antegrade balloon angioplasty techniques for central vein recanalization with concomitant arteriovenous fistula creation is provided.
Autologous arteriovenous (AV) access remains a first-line definitive option for patients on hemodialysis (HD).1 An advantage of an arteriovenous fistula (AVF) compared with grafts is lower infection rates. Critical parameters for an effective AVF are hemodynamically intact inflow/outflow and a vein of acceptable quality that is greater than 2 to 2.5 mm in diameter with no vein wall abnormalities.1 Nonetheless, several patients need urgent dialysis, requiring temporary dialysis catheter placement in a central vein to bridge to AVF creation. Catheters are not exempt from complications, being one of the most common culprits of central vein occlusion, which increases with duration of catheter use.2 Frequently, a complex vein occlusion imposes a challenging scenario, leading to limited alternatives for upper-extremity AV access creation.2 Some options are available to treat central vein occlusion to restore upper-extremity AV access
Division of Vascular Surgery, Stony Brook University Medical Center, Stony Brook, NY. Correspondence to: Rafael D. Malgor, MD, Division of Vascular Surgery, Department of Surgery, Stony Brook University Medical Center, HSC T19 Room 90, Stony Brook, NY 11794-8191, USA; E-mail: [email protected] Ann Vasc Surg 2012; 26: 1012.e17e1012.e20 DOI: 10.1016/j.avsg.2012.02.024 Ó Annals of Vascular Surgery Inc.
availability. Regardless of its durability, open repair with central vein reconstruction requires a thoracotomy and all the risks of a major vascular surgery procedure.3 The advent of endovascular surgery has gained popularity in dialysis patients because of its minimally invasive approach and alleged expeditious recovery and lower morbidity and mortality.2,4 We report a challenging case of a 50-year-old female patient on HD presenting with right upperextremity and facial edema, failed upper-extremity AVF, and a long-segment central venous flush occlusion managed by endovascular treatment and concomitant AV access creation.
CASE REPORT A 50-year-old nondiabetic hypertensive female patient with a previously failed left upper-extremity AVF and a history of multiple permanent dialysis catheters presented with right facial and arm swelling. She also had a right radical nephrectomy for renal cell carcinoma. A permanent dialysis catheter was placed in the right jugular vein after diagnosis of bilateral subclavian occlusion in an outside facility. On admission at our institution, a computed tomography was done to investigate the extent of the central venous obstruction. The jugular, subclavian, and brachiocephalic veins and superior vena cava (SVC) occlusion were identified, with a large azygos vein as the main venous outflow from the upper extremity, head, 1012.e17
1012.e18 Case reports
Annals of Vascular Surgery
Fig. 1. Preoperative imaging workup of a 50-year-old woman on hemodialysis with a history of a failed arteriovenous fistula and multiple previous dialysis catheters, who now presents with right arm and facial edema secondary to central vein occlusion. (A) Computed tomography showing occlusion of the superior vena cava (SVC) and the innominate vein, with a dialysis
catheter in the SVC. (B) The tip of the functional dialysis catheter is seen in the inferior vena cava. (C) Right upper-extremity venography and cavography depicting extensive occlusion of the SVC and the right subclavian and innominate veins. (D) Preoperative right upperextremity duplex ultrasonography showing an adequate cephalic vein in the arm.
and neck (Fig. 1A). Remarkably, the catheter tip was found to be in the inferior vena cava (IVC) (Fig. 1B). A catheterbased venography was also performed to further delineate central venous anatomy, demonstrating right subclavian and internal jugular vein occlusion, flush long-segment right innominate and SVC occlusion, and a large azygos vein (Fig. 1C). A preoperative duplex ultrasonography showed a 4-mm right cephalic vein (Fig. 1D). Treatment options were discussed with the patient, who decided to undergo endovascular therapy. The patient was then taken to the operating room, and three distinct access sites were obtained. The first was gained in the right upper extremity, where an incision was carried out 1 cm above the antecubital fossa to isolate and control the right cephalic vein. A small counter incision was obtained 2 cm distal to the planned fistula site to accommodate a sheath that was carefully inserted in the cephalic vein. A second venous access site was gained through the right jugular vein, which already had the permanent dialysis catheter in place. This was divided at the jugular vein, and a stiff 0.035-inch guidewire was advanced into the IVC, followed by a short 7F sheath. The last venous access was obtained after dissection of the right common femoral vein (CFV). A 5F was initially inserted in the
CFV for diagnostic purposes. It was subsequently exchanged for a 16F Check-Flo introducer (Cook Medical, Bloomington, IN) to enable endovascular treatment. Initially, a 0.035-inch hydrophilic wire was advanced through the right cephalic vein to reach the SVC. Multiple balloon angioplasties were performed in the subclavian vein with an 8 40-mm balloon (Fig. 2A). A glide wire followed by an angled glide catheter was used to recanalize the innominate vein and SCV occlusion through the internal jugular vein. After verifying location in the IVC, the glide wire was exchanged to an Amplatz wire (Cook Medical, Bloomington, IN). An 8 40-mm balloon was then used to dilate the right internal jugular vein (Fig. 2B). The Amplatz wire was then snared through the CFV, establishing through-and-through access (‘‘body floss’’). Subsequently, a 20 40-mm balloon was inserted through the CFV and used to recanalize the right innominate vein and the SVC (Fig. 2C). At the end of the procedure, a right brachiocephalic fistula was created, and a new cuffed dialysis catheter was placed into the SVC through the right internal jugular vein to provide immediate HD access. A completion angiography is depicted in Figure 2D. The patient did well postoperatively, receiving dialysis through her catheter and maintaining a patent
Vol. 26, No. 7, October 2012
Case reports 1012.e19
Fig. 2. Recanalization of right subclavian, internal jugular, innominate veins and SVC. (A) Multiple balloon angioplasties using an 8 40-mm balloon are performed in the right subclavian vein. (B) Subsequent balloon angioplasty of the internal jugular and proximal innominate veins using the same 8 40-mm balloon is carried out. An angled glide catheter is left in place in the right subclavian vein to identify the jugulosubclavian confluence. (C) After snaring the Amplatz wire through the
groin and establishing a through-and-through access (‘‘body floss’’), a low pressure 20 40-mm balloon was parked in the right innominate and SVC with subsequent gentle dilation. (D) Completion venography showing a patent right subclavian and innominate vein and the SVC. Prompt contrast filling of the right ventricle is noted. Finally, a dialysis catheter is replaced through a now patent internal jugular vein.
brachiocephalic fistula. At 6-month follow-up the central veins were patent, and the patient was being dialyzed using the radiocephalic AVF.
For the sake of clarity, complex central vein occlusion may be defined as a long-segment occlusion of the SVC and the innominate veins in association with other venous occlusions, such as that of the subclavian, axillary, or internal jugular veins. Midand long-term outcome data on treatment of complex central vein occlusions related to HD access are still limited to a few series.2e4,8,9 Thus, it still remains controversial whether endovascular treatment should be attempted as first-line treatment for all patients with complex central vein occlusion, including young patients with no limiting cardiovascular risk factors. Other options were potential solutions for this case, including open procedure, endovascular treatment with central vein recanalization, and unusual AV access creation, such as an axillo-axillary or axillo-iliac AV graft.10,11 The latter option is based on few case series availability and should only be
DISCUSSION The number of cases of central vein stenosis and occlusion in patients on HD is expected to increase owing to increasing number of patients requiring HD and longer life expectancy in this subpopulation.5 The main risk factors for central vein occlusion remain central venous catheters and mediastinal and lung malignancies.6,7 The increased number and longevity of patients on HD will eventually lead to more complications related to catheters that are either inserted as a temporizing measure in an urgent dialysis setting to bridge to a more definitive AV access or because of multiple AV access failures and upper-extremity access exhaustion.
1012.e20 Case reports
used when all other efforts have been exhausted. Advocates of an open repair claim that procedure durability is the most significant advantage of this treatment modality. A series of 32 consecutive patients demonstrated primary, assisted primary, and secondary patency rates of 63%, 79%, and 85%, respectively, at 1 year, and 53%, 68%, and 80%, respectively, at 5 years.11 The drawbacks of open repair are the need for a thoracotomy, a longer procedure with either spiral vein creation or bypass, and the morbidity and mortality related to thoracotomy and a major vascular surgery. In addition, patients with limited cardiopulmonary reserve may not be candidates for open surgery. The durability of endovascular treatment is still emphasized as a significant disadvantage of this treatment modality; however, patient preference and decreased morbidity and mortality despite age or other comorbidities are significant advantages. Furthermore, a series from the Mayo Clinic demonstrated similar patency rates between endovascular and open central vein reconstructive surgery.8 In that series of 70 patients, primary, assisted primary, and secondary patency rates of surgical bypass grafts and endovascular treatment were 45%, 68%, and 75% versus 44%, 96%, and 96% at 3 years, respectively.8 Nonetheless, Bakken et al. analyzing 73 HD patients with central vein occlusion treated with angioplasty alone and angioplasty and stenting reported 29% and 21% primary patency rates for angioplasty and stenting at 12-month follow-up.4 In another series of 69 HD patients, a similar central vein primary patency rate of 22% after endovascular treatment at 1-year follow-up was reported.12 Despite lower primary patency rates, reasonable assisted primary and secondary patencies of balloon angioplasty of >60% at 1-year follow-up were reported in both of these series.4,12 Some remarkable points deserve attention in this challenging case. First, endovascular treatment should be attempted first in patients with central venous occlusion secondary to HD catheters before subjecting patients to a major thoracic surgery with central vein bypass. Endovascular therapy carries lower morbidity and excellent success rates, as reported in the literature.8 Second, angioplasty alone to treat complex central vein occlusion with concomitant AVF creation has several advantages, such as treatment of central vein obstructive symptoms, expeditious removal of a dialysis catheter, prompt restoration of upper-extremity AV access availability, one-stage treatment of central vein occlusion and AV access creation, and reduced length of hospital stay compared with either open surgery or endovascular intervention alone with a second-stage operation
Annals of Vascular Surgery
for AVF creation. As a result, patient satisfaction may be greatly improved. Third, AVF creation likely has the effect of increasing blood flow through the newly recanalized central veins, thereby improving venous outflow patency. Despite all these benefits, however, lengthy discussion regarding the longterm outcomes and likely reinterventions must be carried out with the patient before any endovascular procedure.
CONCLUSION Complex cases of central venous occlusion in HD patients who require AV access creation have become more frequent as both life expectancy and the number of patients on HD increase. This case outlines the safety and feasibility of a complex central vein recanalization with concomitant AVF creation to restore AV access availability and expedite patient recovery. REFERENCES 1. III. NKF-K/DOQI Clinical practice guidelines for vascular access: update 2000. Am J Kidney Dis 2001;37:S137e81. 2. Pikwer A, Acosta S, Kolbel T, Akeson J. Endovascular intervention for central venous cannulation in patients with vascular occlusion after previous catheterization. J Vasc Access 2010;11:323e8. 3. Anaya-Ayala JE, Bellows PH, Ismail N, et al. Surgical management of hemodialysis-related central venous occlusive disease: a treatment algorithm. Ann Vasc Surg 2011;25:108e19. 4. Bakken AM, Protack CD, Saad WE, et al. Long-term outcomes of primary angioplasty and primary stenting of central venous stenosis in hemodialysis patients. J Vasc Surg 2007;45:776e83. 5. Altman SD. A practical approach for diagnosis and treatment of central venous stenosis and occlusion. Semin Vasc Surg 2007;20:189e94. 6. Beathard GA. Percutaneous transvenous angioplasty in the treatment of vascular access stenosis. Kidney Int 1992;42: 1390e7. 7. Wilson LD, Detterbeck FC, Yahalom J. Clinical practice. Superior vena cava syndrome with malignant causes. N Engl J Med 2007;356:1862e9. 8. Rizvi AZ, Kalra M, Bjarnason H, et al. Benign superior vena cava syndrome: stenting is now the first line of treatment. J Vasc Surg 2008;47:372e80. 9. Anaya-Ayala JE, Smolock CJ, Colvard BD, et al. Efficacy of covered stent placement for central venous occlusive disease in hemodialysis patients. J Vasc Surg 2011;54:754e9. 10. Jakimowicz T, Galazka Z, Grochowiecki T, et al. Vascular access for haemodialysis in patients with central vein thrombosis. Eur J Vasc Endovasc Surg 2011;42:842e9. 11. Kalra M, Gloviczki P, Andrews JC, et al. Open surgical and endovascular treatment of superior vena cava syndrome caused by nonmalignant disease. J Vasc Surg 2003;38:215e23. 12. Nael K, Kee ST, Solomon H, Katz SG. Endovascular management of central thoracic veno-occlusive diseases in hemodialysis patients: a single institutional experience in 69 consecutive patients. J Vasc Interv Radiol 2009;20:46e51.
Recanalization of long-segment central vein flush occlusion in hemodialysis patients has been advocated in lieu of central vein bypass and thoracotomy to restore arteriovenous access availability. We report a challenging case of complex central venous flush occlusion in a 50-year-old woman on hemodialysis who presented with right arm and facial swelling. A concise step-bystep description of endovascular strategy with retrograde and antegrade balloon angioplasty techniques for central vein recanalization with concomitant arteriovenous fistula creation is provided.
Autologous arteriovenous (AV) access remains a first-line definitive option for patients on hemodialysis (HD).1 An advantage of an arteriovenous fistula (AVF) compared with grafts is lower infection rates. Critical parameters for an effective AVF are hemodynamically intact inflow/outflow and a vein of acceptable quality that is greater than 2 to 2.5 mm in diameter with no vein wall abnormalities.1 Nonetheless, several patients need urgent dialysis, requiring temporary dialysis catheter placement in a central vein to bridge to AVF creation. Catheters are not exempt from complications, being one of the most common culprits of central vein occlusion, which increases with duration of catheter use.2 Frequently, a complex vein occlusion imposes a challenging scenario, leading to limited alternatives for upper-extremity AV access creation.2 Some options are available to treat central vein occlusion to restore upper-extremity AV access
Division of Vascular Surgery, Stony Brook University Medical Center, Stony Brook, NY. Correspondence to: Rafael D. Malgor, MD, Division of Vascular Surgery, Department of Surgery, Stony Brook University Medical Center, HSC T19 Room 90, Stony Brook, NY 11794-8191, USA; E-mail: [email protected] Ann Vasc Surg 2012; 26: 1012.e17e1012.e20 DOI: 10.1016/j.avsg.2012.02.024 Ó Annals of Vascular Surgery Inc.
availability. Regardless of its durability, open repair with central vein reconstruction requires a thoracotomy and all the risks of a major vascular surgery procedure.3 The advent of endovascular surgery has gained popularity in dialysis patients because of its minimally invasive approach and alleged expeditious recovery and lower morbidity and mortality.2,4 We report a challenging case of a 50-year-old female patient on HD presenting with right upperextremity and facial edema, failed upper-extremity AVF, and a long-segment central venous flush occlusion managed by endovascular treatment and concomitant AV access creation.
CASE REPORT A 50-year-old nondiabetic hypertensive female patient with a previously failed left upper-extremity AVF and a history of multiple permanent dialysis catheters presented with right facial and arm swelling. She also had a right radical nephrectomy for renal cell carcinoma. A permanent dialysis catheter was placed in the right jugular vein after diagnosis of bilateral subclavian occlusion in an outside facility. On admission at our institution, a computed tomography was done to investigate the extent of the central venous obstruction. The jugular, subclavian, and brachiocephalic veins and superior vena cava (SVC) occlusion were identified, with a large azygos vein as the main venous outflow from the upper extremity, head, 1012.e17
1012.e18 Case reports
Annals of Vascular Surgery
Fig. 1. Preoperative imaging workup of a 50-year-old woman on hemodialysis with a history of a failed arteriovenous fistula and multiple previous dialysis catheters, who now presents with right arm and facial edema secondary to central vein occlusion. (A) Computed tomography showing occlusion of the superior vena cava (SVC) and the innominate vein, with a dialysis
catheter in the SVC. (B) The tip of the functional dialysis catheter is seen in the inferior vena cava. (C) Right upper-extremity venography and cavography depicting extensive occlusion of the SVC and the right subclavian and innominate veins. (D) Preoperative right upperextremity duplex ultrasonography showing an adequate cephalic vein in the arm.
and neck (Fig. 1A). Remarkably, the catheter tip was found to be in the inferior vena cava (IVC) (Fig. 1B). A catheterbased venography was also performed to further delineate central venous anatomy, demonstrating right subclavian and internal jugular vein occlusion, flush long-segment right innominate and SVC occlusion, and a large azygos vein (Fig. 1C). A preoperative duplex ultrasonography showed a 4-mm right cephalic vein (Fig. 1D). Treatment options were discussed with the patient, who decided to undergo endovascular therapy. The patient was then taken to the operating room, and three distinct access sites were obtained. The first was gained in the right upper extremity, where an incision was carried out 1 cm above the antecubital fossa to isolate and control the right cephalic vein. A small counter incision was obtained 2 cm distal to the planned fistula site to accommodate a sheath that was carefully inserted in the cephalic vein. A second venous access site was gained through the right jugular vein, which already had the permanent dialysis catheter in place. This was divided at the jugular vein, and a stiff 0.035-inch guidewire was advanced into the IVC, followed by a short 7F sheath. The last venous access was obtained after dissection of the right common femoral vein (CFV). A 5F was initially inserted in the
CFV for diagnostic purposes. It was subsequently exchanged for a 16F Check-Flo introducer (Cook Medical, Bloomington, IN) to enable endovascular treatment. Initially, a 0.035-inch hydrophilic wire was advanced through the right cephalic vein to reach the SVC. Multiple balloon angioplasties were performed in the subclavian vein with an 8 40-mm balloon (Fig. 2A). A glide wire followed by an angled glide catheter was used to recanalize the innominate vein and SCV occlusion through the internal jugular vein. After verifying location in the IVC, the glide wire was exchanged to an Amplatz wire (Cook Medical, Bloomington, IN). An 8 40-mm balloon was then used to dilate the right internal jugular vein (Fig. 2B). The Amplatz wire was then snared through the CFV, establishing through-and-through access (‘‘body floss’’). Subsequently, a 20 40-mm balloon was inserted through the CFV and used to recanalize the right innominate vein and the SVC (Fig. 2C). At the end of the procedure, a right brachiocephalic fistula was created, and a new cuffed dialysis catheter was placed into the SVC through the right internal jugular vein to provide immediate HD access. A completion angiography is depicted in Figure 2D. The patient did well postoperatively, receiving dialysis through her catheter and maintaining a patent
Vol. 26, No. 7, October 2012
Case reports 1012.e19
Fig. 2. Recanalization of right subclavian, internal jugular, innominate veins and SVC. (A) Multiple balloon angioplasties using an 8 40-mm balloon are performed in the right subclavian vein. (B) Subsequent balloon angioplasty of the internal jugular and proximal innominate veins using the same 8 40-mm balloon is carried out. An angled glide catheter is left in place in the right subclavian vein to identify the jugulosubclavian confluence. (C) After snaring the Amplatz wire through the
groin and establishing a through-and-through access (‘‘body floss’’), a low pressure 20 40-mm balloon was parked in the right innominate and SVC with subsequent gentle dilation. (D) Completion venography showing a patent right subclavian and innominate vein and the SVC. Prompt contrast filling of the right ventricle is noted. Finally, a dialysis catheter is replaced through a now patent internal jugular vein.
brachiocephalic fistula. At 6-month follow-up the central veins were patent, and the patient was being dialyzed using the radiocephalic AVF.
For the sake of clarity, complex central vein occlusion may be defined as a long-segment occlusion of the SVC and the innominate veins in association with other venous occlusions, such as that of the subclavian, axillary, or internal jugular veins. Midand long-term outcome data on treatment of complex central vein occlusions related to HD access are still limited to a few series.2e4,8,9 Thus, it still remains controversial whether endovascular treatment should be attempted as first-line treatment for all patients with complex central vein occlusion, including young patients with no limiting cardiovascular risk factors. Other options were potential solutions for this case, including open procedure, endovascular treatment with central vein recanalization, and unusual AV access creation, such as an axillo-axillary or axillo-iliac AV graft.10,11 The latter option is based on few case series availability and should only be
DISCUSSION The number of cases of central vein stenosis and occlusion in patients on HD is expected to increase owing to increasing number of patients requiring HD and longer life expectancy in this subpopulation.5 The main risk factors for central vein occlusion remain central venous catheters and mediastinal and lung malignancies.6,7 The increased number and longevity of patients on HD will eventually lead to more complications related to catheters that are either inserted as a temporizing measure in an urgent dialysis setting to bridge to a more definitive AV access or because of multiple AV access failures and upper-extremity access exhaustion.
1012.e20 Case reports
used when all other efforts have been exhausted. Advocates of an open repair claim that procedure durability is the most significant advantage of this treatment modality. A series of 32 consecutive patients demonstrated primary, assisted primary, and secondary patency rates of 63%, 79%, and 85%, respectively, at 1 year, and 53%, 68%, and 80%, respectively, at 5 years.11 The drawbacks of open repair are the need for a thoracotomy, a longer procedure with either spiral vein creation or bypass, and the morbidity and mortality related to thoracotomy and a major vascular surgery. In addition, patients with limited cardiopulmonary reserve may not be candidates for open surgery. The durability of endovascular treatment is still emphasized as a significant disadvantage of this treatment modality; however, patient preference and decreased morbidity and mortality despite age or other comorbidities are significant advantages. Furthermore, a series from the Mayo Clinic demonstrated similar patency rates between endovascular and open central vein reconstructive surgery.8 In that series of 70 patients, primary, assisted primary, and secondary patency rates of surgical bypass grafts and endovascular treatment were 45%, 68%, and 75% versus 44%, 96%, and 96% at 3 years, respectively.8 Nonetheless, Bakken et al. analyzing 73 HD patients with central vein occlusion treated with angioplasty alone and angioplasty and stenting reported 29% and 21% primary patency rates for angioplasty and stenting at 12-month follow-up.4 In another series of 69 HD patients, a similar central vein primary patency rate of 22% after endovascular treatment at 1-year follow-up was reported.12 Despite lower primary patency rates, reasonable assisted primary and secondary patencies of balloon angioplasty of >60% at 1-year follow-up were reported in both of these series.4,12 Some remarkable points deserve attention in this challenging case. First, endovascular treatment should be attempted first in patients with central venous occlusion secondary to HD catheters before subjecting patients to a major thoracic surgery with central vein bypass. Endovascular therapy carries lower morbidity and excellent success rates, as reported in the literature.8 Second, angioplasty alone to treat complex central vein occlusion with concomitant AVF creation has several advantages, such as treatment of central vein obstructive symptoms, expeditious removal of a dialysis catheter, prompt restoration of upper-extremity AV access availability, one-stage treatment of central vein occlusion and AV access creation, and reduced length of hospital stay compared with either open surgery or endovascular intervention alone with a second-stage operation
Annals of Vascular Surgery
for AVF creation. As a result, patient satisfaction may be greatly improved. Third, AVF creation likely has the effect of increasing blood flow through the newly recanalized central veins, thereby improving venous outflow patency. Despite all these benefits, however, lengthy discussion regarding the longterm outcomes and likely reinterventions must be carried out with the patient before any endovascular procedure.
CONCLUSION Complex cases of central venous occlusion in HD patients who require AV access creation have become more frequent as both life expectancy and the number of patients on HD increase. This case outlines the safety and feasibility of a complex central vein recanalization with concomitant AVF creation to restore AV access availability and expedite patient recovery. REFERENCES 1. III. NKF-K/DOQI Clinical practice guidelines for vascular access: update 2000. Am J Kidney Dis 2001;37:S137e81. 2. Pikwer A, Acosta S, Kolbel T, Akeson J. Endovascular intervention for central venous cannulation in patients with vascular occlusion after previous catheterization. J Vasc Access 2010;11:323e8. 3. Anaya-Ayala JE, Bellows PH, Ismail N, et al. Surgical management of hemodialysis-related central venous occlusive disease: a treatment algorithm. Ann Vasc Surg 2011;25:108e19. 4. Bakken AM, Protack CD, Saad WE, et al. Long-term outcomes of primary angioplasty and primary stenting of central venous stenosis in hemodialysis patients. J Vasc Surg 2007;45:776e83. 5. Altman SD. A practical approach for diagnosis and treatment of central venous stenosis and occlusion. Semin Vasc Surg 2007;20:189e94. 6. Beathard GA. Percutaneous transvenous angioplasty in the treatment of vascular access stenosis. Kidney Int 1992;42: 1390e7. 7. Wilson LD, Detterbeck FC, Yahalom J. Clinical practice. Superior vena cava syndrome with malignant causes. N Engl J Med 2007;356:1862e9. 8. Rizvi AZ, Kalra M, Bjarnason H, et al. Benign superior vena cava syndrome: stenting is now the first line of treatment. J Vasc Surg 2008;47:372e80. 9. Anaya-Ayala JE, Smolock CJ, Colvard BD, et al. Efficacy of covered stent placement for central venous occlusive disease in hemodialysis patients. J Vasc Surg 2011;54:754e9. 10. Jakimowicz T, Galazka Z, Grochowiecki T, et al. Vascular access for haemodialysis in patients with central vein thrombosis. Eur J Vasc Endovasc Surg 2011;42:842e9. 11. Kalra M, Gloviczki P, Andrews JC, et al. Open surgical and endovascular treatment of superior vena cava syndrome caused by nonmalignant disease. J Vasc Surg 2003;38:215e23. 12. Nael K, Kee ST, Solomon H, Katz SG. Endovascular management of central thoracic veno-occlusive diseases in hemodialysis patients: a single institutional experience in 69 consecutive patients. J Vasc Interv Radiol 2009;20:46e51.