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May-Thurner syndrome in an adolescent: Persistence despite operative management
May-Thurner syndrome in an adolescent: Persistence despite operative management Cristina Simon, MD, José Alvarez, Jr, MD, Gary J. Becker, MD, Barry T. Katzen, MD, James F. Benenati, MD, and Gerald Zemel, MD, Miami, Fla We describe a patient with May-Thurner syndrome who underwent operative transection and transposition of the right common iliac artery without direct venous repair, because preoperative and intraoperative intravascular ultrasound scans were negative for “spurs” in the left common iliac vein. When symptoms and signs persisted, a postoperative magnetic resonance venogram (MRV) showed severe stenosis in the left common iliac vein. Progressive, but incomplete, clinical improvement occurred with conservative management. (J Vasc Surg 1999;30:950-3.)
The predominance of left-sided over right-sided iliofemoral venous thrombosis is a result, at least in part, of compression of the left common iliac vein by the right common iliac artery at Cockett’s point (their crossing point). This venous compression combined with focal intimal hyperplasia of the left common iliac vein was first described by May and Thurner1 in 1956. In 22% of cases, they discovered an intraluminal “spur” in the left common iliac vein segment underlying the right common iliac artery. This abnormality was nicely depicted diagrammatically in a subsequent article by Ferris et al.2 May and Thurner also showed that spurs are not congenital variants, as was previously thought,3 but develop during life, and they noted a preponderance in females. The purpose of our report is to provide an opportunity for the reader to reason his or her way through the clinical decision-making in a surgical case with a suboptimal clinical outcome to elucidate proper measures for similar future cases. CASE REPORT A 15-year-old girl gave a 4-month history of left leg swelling and pain in the upper thigh. There was no history of injury or deep vein thrombosis, and the right lower extremity was asymptomatic. The patient had been wearing a knee-high support stocking because the swelling
From the Division of Vascular and Interventional Radiology and Division of Vascular Surgery (Dr Alvarez), Miami Cardiac and Vascular Institute. Reprint requests: Dr Gary J. Becker, Miami Cardiac and Vascular Institute, 8900 N. Kendall Dr, Miami, FL 33176. Copyright © 1999 by the Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter. 0741-5214/99/$8.00 + 0 24/4/100901
950
worsened during her regular dance and gymnastic activities. On physical examination, the left ankle was edematous, but neither the calf nor the thigh was enlarged. A color Doppler flow imaging study revealed patency of the entire left lower extremity venous system but decreased phasicity in the left common and external iliac veins. May-Thurner syndrome was suspected. To confirm the diagnosis anatomically, we obtained a magnetic resonance venogram (MRV), which disclosed a patent venous system with an hourglass deformity at Cockett’s point (Fig 1). No significant collateral flow was observed. In the final preoperative planning, a transfemoral left iliocaval contrast venogram showed marked extrinsic compression of the left common iliac vein, but no spurs. The intraluminal pressure was 12 mm Hg in the external iliac vein and 6 mm Hg in the inferior vena cava. During the same procedure, an intravascular ultrasound scanning (IVUS) study was performed with a Hewlett-Packard ultrasound scanning system and a 20-MHz rotating mechanical catheter transducer (Fig 2). The crossing point of the right common iliac artery and the left common iliac vein was easily depicted, as was the extrinsic compression of the vein by the artery. However, no spurs or intraluminal abnormalities of any kind were found. After considerable discussion of treatment options, the patient was taken to the operating room, where, through a left retroperitoneal incision, the following vessels were exposed: the distal abdominal aorta; the right common, external, and internal iliac arteries; the inferior vena cava; and the left common, external, and internal iliac veins. Intraoperative IVUS once again showed the extrinsic compression at Cockett’s point but showed no intraluminal spurs or other abnormalities. Therefore, the left common iliac vein was not entered. Instead, care was taken not to injure the vein as the right common iliac artery was isolated between proximal and distal clamps, then transected and transposed to a posterior position behind the left common iliac artery (Fig 3). Because the vein was not entered, a decision was made not to patch it. The postoperative period was uncomplicated, and the
JOURNAL OF VASCULAR SURGERY Volume 30, Number 5
Simon et al
951
Fig 1. Magnetic resonance venogram (MRV). Encoded for direction of flow, this magnetic resonance study depicts both arterial and venous structures with opposite signals. The left common iliac vein has an hourglass deformity at Cockett’s point (the crossing point of the right common iliac artery and left common iliac vein).
Fig 2. Intravascular ultrasound scan. The probe is positioned in the left common iliac vein at Cockett’s point. The vein is compressed by the right common iliac artery; however, the lumen is open and there is no evidence of an intimal spur.
patient was discharged 3 days later with good peripheral pulses. The swelling of the left calf had not resolved completely, and the patient was still wearing her support stocking at the time of discharge. On physical examination 6 weeks later, the leg swelling had decreased slightly, but the patient still required support stockings to manage the increase in swelling that was occurring with exercise. A follow-up MRV with the same scan parameters and regions of interest as those of the preoperative study showed a 3cm, high-grade stenosis of the left common iliac vein with an irregular mural contour (Fig 4). The peripheral veins of the left lower extremity were patent. Oral anticoagulant therapy with warfarin was initiated, and conservative management with the compression stocking was continued. At the 6-month postoperative follow-up visit, the patient showed clinical improvement, but the leg swelling had not completely resolved.
venectomy and patch angioplasty or direct venous bypass has been the favored approach, and the operative techniques have been described elsewhere.4,5 Recently, a number of authors have reported reasonable safety and efficacy of transluminal venous stenting for both benign and malignant venous stenoses.6-13 Most important among these for purposes of the present discussion is the report of Binkert et al,6 in which eight patients with May-Thurner syndrome, four of whom had surgical thrombectomy before definitive management, were treated with transluminal WallStent (Boston Scientific Vascular, Natick, Mass) placement. All eight patients experienced immediate relief of leg swelling, and patency at follow-up of 10 to 121 months (mean, 3 years) was 100% by color Doppler flow imaging (n = 6) or venography (n = 2). There were no procedural or stent-related complications. Stenting smoothed the intimal abnormalities in these cases and improved venous outflow. The hoop strength inherent to the self-expanding stent also limited compression by the overlying right common iliac artery. Importantly, although no complications have been reported to date, the long-term efficacy in the left common iliac vein, long-term structural integrity of the stent in this position, and potential ill effects of the stent on the overlying artery are still uncertain.
DISCUSSION In human vessel entrapment syndromes—including May-Thurner syndrome, thoracic outlet and inlet syndromes, the “nutcracker” syndrome, and the popliteal entrapment syndrome—the common pathophysiologic basis is as follows: extrinsic compression leads to injury of intimal endothelial cells and medial myocytes. The result is mural thickening and intimal hyperplasia. Surgical decompression with or without endo-
952 Simon et al
JOURNAL OF VASCULAR SURGERY November 1999
A
B
Fig 3. Intraoperative photographs. Before (A) and after (B) transposition of the right common iliac artery posteriorly.
In our case, these uncertainties, the patient’s youth, and the additional potential complications that future pregnancies might engender all led to the decision not to treat the patient with transluminal stenting. Nevertheless, a decision to treat aggressively was still dictated by the increase in symptoms occurring with the patient’s dance and gymnastic activities. The decision not to enter the left common iliac vein at surgery was based solely on the lack of a demonstrable web on either the preoperative venogram or the IVUS studies (both preoperative and intraoperative). The operators have a high level of experience with IVUS and a high level of confidence
Fig 4. Follow-up magnetic resonance venogram (MRV). This single image from the follow-up MRV 6 weeks after surgery reveals marked narrowing of the left common iliac vein lumen, with an irregular mural contour. The irregular contour may be a result of actual structural abnormality such as perivenous scar or intimal hyperplasia, but this signal abnormality may also be a result of complex or turbulent flow in this vein segment.
in IVUS and, in particular, its ability to depict bloodflow in the lumen and detailed anatomy at or near the luminal surface. The anatomic abnormalities (intraluminal spurs) sought in this case, if actually present, would have been seen easily with the 20-MHz rotating mechanical transducer and ultrasound scanning system that were used. The follow-up MRV was valuable in the depiction of the irregular mural contour and luminal narrowing of the left common iliac vein and in the avoidance of more invasive testing. However, MRV cannot be relied on for identification and characterization of intimal abnormalities because signal abnormalities in the vein may be caused by complex or turbulent flow. To
JOURNAL OF VASCULAR SURGERY Volume 30, Number 5
what, then, can the persistent edema and abnormal MRV be attributed? In the absence of further invasive testing, the best possibilities are either continued extrinsic compression by the (now posterior) right common iliac artery, perivenous scarring resulting from surgery, or intimal hyperplasia in the vein as a result of manipulation at surgery. One other, less likely possibility is a focal thrombosis that did not propagate retrograde, was not associated with clinical worsening, and partially recanalized in the first 6 weeks after surgery. Because the edema persisted throughout the postoperative period, rather than resolving and then recurring, the most likely cause is ongoing extrinsic compression by the right common iliac artery. As far as our patient’s ongoing management is concerned, although it might appear logical to restudy her with transfemoral iliocaval venography and IVUS, we would still choose, no matter what the findings, not to re-operate and not to place a WallStent for all of the reasons mentioned above. Thus, we made the decision to initiate oral anticoagulation therapy and continue with the compression stockings. A glimpse of how we might approach a newly diagnosed case of May-Thurner syndrome serves to highlight the teaching points of this case. Although in an adult, we would likely resort to transluminal stenting as a first-choice therapy, we would still choose an operative approach for young, active females of childbearing potential and thereby avoid stenting. However, we would also definitely enter the left common iliac vein at surgery. In each case, this would be beneficial in at least one of two ways. First, in cases with a clearly defined spur on preoperative and intraoperative studies, entering the vein is necessary to perform endovenectomy and patching. Second, in cases with no spur seen on imaging studies, entering the vein provides the means for patch angioplasty, a procedure that should do the most we can to minimize luminal compromise caused by ongoing compression, extrinsic perivenous scarring, or intimal hyperplasia.
Simon et al
953
REFERENCES 1. May R, Thurner J. Ein Gefässporn in der Vena iliaca communis sinistra als wahrscheinliche Ursache der überwiegende linksseitigen Beckenvenenthrombose. Ztschr. Fuer Kreislaufforschg 1956;45:912. 2. Ferris EJ, Lim WN, Smith PL, Casali R. May-Thurner syndrome. Radiology 1983;147:29-31. 3. McMurich JP. Congenital adhesion in the common iliac veins. Anat Record 1906;1:78-9. 4. Alimi YS, DiMauro P, Fabre D, Juhan C. Iliac vein reconstruction to treat acute and chronic venous disease. J Vasc Surg 1997;25:673-81. 5. Lalka SG. Management of chronic obstructive venous disease of the lower extremity. In: Rutherford RB, editor. Vascular surgery. Vol 2. 4th ed. Philadelphia: WB Saunders, 1995; p. 1862-82. 6. Binkert CA, Schoch E, Stuckmann G, et al. Treatment of pelvic venous spur (May-Thurner syndrome) with selfexpanding metallic endoprostheses. Cardiovasc Intervent Radiol 1998;21:22-6. 7. Rilinger N, Görich J, Mickley V, et al. Endovascular stenting in patients with iliac compression syndrome: experience in three cases. Invest Radiol 1996;31:729-33. 8. Berger A, Jaffe JW, York TN, et al. Iliac compression syndrome treated with stent placement. J Vasc Surg 1995;21:510-4. 9. Elson JD, Becker GJ, Wholey M, et al. Vena caval and central venous stenoses: management with Palmaz balloon-expandable intraluminal stents. J Vasc Intervent Radiol 1991;2:215-23. 10. Antonucci F, Salomonowitz E, Stuckmann G, Stiefel M, Largadier I, Zollikofer CL. Placement of venous stents: clinical experience with a self-expanding prosthesis. Radiology 1992;183:493-7. 11. Rösch J, Petersen BD, Lakin PC. Venous stents: indications, technique, results. In: Perler and Becker, editors. Vascular intervention: a clinical approach. New York: Thieme; 1998. p. 705-10. 12. Gray RJ. Central venous stenosis in hemodialysis patients. In: Trerotola SO, Savader SJ, and Durham JD, editors. Venous interventions. Fairfax: The Society of Cardiovascular and Interventional Radiology; 1995. p. 123-35. 13. Semba CP. Central venous stents: an overview. In: Trerotola SO, Savader SJ, and Durham JD, editors. Venous interventions. Fairfax: The Society of Cardiovascular and Interventional Radiology; 1995. p. 1136-51.
Submitted Jul 9, 1998; accepted Apr 19, 1999.
The predominance of left-sided over right-sided iliofemoral venous thrombosis is a result, at least in part, of compression of the left common iliac vein by the right common iliac artery at Cockett’s point (their crossing point). This venous compression combined with focal intimal hyperplasia of the left common iliac vein was first described by May and Thurner1 in 1956. In 22% of cases, they discovered an intraluminal “spur” in the left common iliac vein segment underlying the right common iliac artery. This abnormality was nicely depicted diagrammatically in a subsequent article by Ferris et al.2 May and Thurner also showed that spurs are not congenital variants, as was previously thought,3 but develop during life, and they noted a preponderance in females. The purpose of our report is to provide an opportunity for the reader to reason his or her way through the clinical decision-making in a surgical case with a suboptimal clinical outcome to elucidate proper measures for similar future cases. CASE REPORT A 15-year-old girl gave a 4-month history of left leg swelling and pain in the upper thigh. There was no history of injury or deep vein thrombosis, and the right lower extremity was asymptomatic. The patient had been wearing a knee-high support stocking because the swelling
From the Division of Vascular and Interventional Radiology and Division of Vascular Surgery (Dr Alvarez), Miami Cardiac and Vascular Institute. Reprint requests: Dr Gary J. Becker, Miami Cardiac and Vascular Institute, 8900 N. Kendall Dr, Miami, FL 33176. Copyright © 1999 by the Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter. 0741-5214/99/$8.00 + 0 24/4/100901
950
worsened during her regular dance and gymnastic activities. On physical examination, the left ankle was edematous, but neither the calf nor the thigh was enlarged. A color Doppler flow imaging study revealed patency of the entire left lower extremity venous system but decreased phasicity in the left common and external iliac veins. May-Thurner syndrome was suspected. To confirm the diagnosis anatomically, we obtained a magnetic resonance venogram (MRV), which disclosed a patent venous system with an hourglass deformity at Cockett’s point (Fig 1). No significant collateral flow was observed. In the final preoperative planning, a transfemoral left iliocaval contrast venogram showed marked extrinsic compression of the left common iliac vein, but no spurs. The intraluminal pressure was 12 mm Hg in the external iliac vein and 6 mm Hg in the inferior vena cava. During the same procedure, an intravascular ultrasound scanning (IVUS) study was performed with a Hewlett-Packard ultrasound scanning system and a 20-MHz rotating mechanical catheter transducer (Fig 2). The crossing point of the right common iliac artery and the left common iliac vein was easily depicted, as was the extrinsic compression of the vein by the artery. However, no spurs or intraluminal abnormalities of any kind were found. After considerable discussion of treatment options, the patient was taken to the operating room, where, through a left retroperitoneal incision, the following vessels were exposed: the distal abdominal aorta; the right common, external, and internal iliac arteries; the inferior vena cava; and the left common, external, and internal iliac veins. Intraoperative IVUS once again showed the extrinsic compression at Cockett’s point but showed no intraluminal spurs or other abnormalities. Therefore, the left common iliac vein was not entered. Instead, care was taken not to injure the vein as the right common iliac artery was isolated between proximal and distal clamps, then transected and transposed to a posterior position behind the left common iliac artery (Fig 3). Because the vein was not entered, a decision was made not to patch it. The postoperative period was uncomplicated, and the
JOURNAL OF VASCULAR SURGERY Volume 30, Number 5
Simon et al
951
Fig 1. Magnetic resonance venogram (MRV). Encoded for direction of flow, this magnetic resonance study depicts both arterial and venous structures with opposite signals. The left common iliac vein has an hourglass deformity at Cockett’s point (the crossing point of the right common iliac artery and left common iliac vein).
Fig 2. Intravascular ultrasound scan. The probe is positioned in the left common iliac vein at Cockett’s point. The vein is compressed by the right common iliac artery; however, the lumen is open and there is no evidence of an intimal spur.
patient was discharged 3 days later with good peripheral pulses. The swelling of the left calf had not resolved completely, and the patient was still wearing her support stocking at the time of discharge. On physical examination 6 weeks later, the leg swelling had decreased slightly, but the patient still required support stockings to manage the increase in swelling that was occurring with exercise. A follow-up MRV with the same scan parameters and regions of interest as those of the preoperative study showed a 3cm, high-grade stenosis of the left common iliac vein with an irregular mural contour (Fig 4). The peripheral veins of the left lower extremity were patent. Oral anticoagulant therapy with warfarin was initiated, and conservative management with the compression stocking was continued. At the 6-month postoperative follow-up visit, the patient showed clinical improvement, but the leg swelling had not completely resolved.
venectomy and patch angioplasty or direct venous bypass has been the favored approach, and the operative techniques have been described elsewhere.4,5 Recently, a number of authors have reported reasonable safety and efficacy of transluminal venous stenting for both benign and malignant venous stenoses.6-13 Most important among these for purposes of the present discussion is the report of Binkert et al,6 in which eight patients with May-Thurner syndrome, four of whom had surgical thrombectomy before definitive management, were treated with transluminal WallStent (Boston Scientific Vascular, Natick, Mass) placement. All eight patients experienced immediate relief of leg swelling, and patency at follow-up of 10 to 121 months (mean, 3 years) was 100% by color Doppler flow imaging (n = 6) or venography (n = 2). There were no procedural or stent-related complications. Stenting smoothed the intimal abnormalities in these cases and improved venous outflow. The hoop strength inherent to the self-expanding stent also limited compression by the overlying right common iliac artery. Importantly, although no complications have been reported to date, the long-term efficacy in the left common iliac vein, long-term structural integrity of the stent in this position, and potential ill effects of the stent on the overlying artery are still uncertain.
DISCUSSION In human vessel entrapment syndromes—including May-Thurner syndrome, thoracic outlet and inlet syndromes, the “nutcracker” syndrome, and the popliteal entrapment syndrome—the common pathophysiologic basis is as follows: extrinsic compression leads to injury of intimal endothelial cells and medial myocytes. The result is mural thickening and intimal hyperplasia. Surgical decompression with or without endo-
952 Simon et al
JOURNAL OF VASCULAR SURGERY November 1999
A
B
Fig 3. Intraoperative photographs. Before (A) and after (B) transposition of the right common iliac artery posteriorly.
In our case, these uncertainties, the patient’s youth, and the additional potential complications that future pregnancies might engender all led to the decision not to treat the patient with transluminal stenting. Nevertheless, a decision to treat aggressively was still dictated by the increase in symptoms occurring with the patient’s dance and gymnastic activities. The decision not to enter the left common iliac vein at surgery was based solely on the lack of a demonstrable web on either the preoperative venogram or the IVUS studies (both preoperative and intraoperative). The operators have a high level of experience with IVUS and a high level of confidence
Fig 4. Follow-up magnetic resonance venogram (MRV). This single image from the follow-up MRV 6 weeks after surgery reveals marked narrowing of the left common iliac vein lumen, with an irregular mural contour. The irregular contour may be a result of actual structural abnormality such as perivenous scar or intimal hyperplasia, but this signal abnormality may also be a result of complex or turbulent flow in this vein segment.
in IVUS and, in particular, its ability to depict bloodflow in the lumen and detailed anatomy at or near the luminal surface. The anatomic abnormalities (intraluminal spurs) sought in this case, if actually present, would have been seen easily with the 20-MHz rotating mechanical transducer and ultrasound scanning system that were used. The follow-up MRV was valuable in the depiction of the irregular mural contour and luminal narrowing of the left common iliac vein and in the avoidance of more invasive testing. However, MRV cannot be relied on for identification and characterization of intimal abnormalities because signal abnormalities in the vein may be caused by complex or turbulent flow. To
JOURNAL OF VASCULAR SURGERY Volume 30, Number 5
what, then, can the persistent edema and abnormal MRV be attributed? In the absence of further invasive testing, the best possibilities are either continued extrinsic compression by the (now posterior) right common iliac artery, perivenous scarring resulting from surgery, or intimal hyperplasia in the vein as a result of manipulation at surgery. One other, less likely possibility is a focal thrombosis that did not propagate retrograde, was not associated with clinical worsening, and partially recanalized in the first 6 weeks after surgery. Because the edema persisted throughout the postoperative period, rather than resolving and then recurring, the most likely cause is ongoing extrinsic compression by the right common iliac artery. As far as our patient’s ongoing management is concerned, although it might appear logical to restudy her with transfemoral iliocaval venography and IVUS, we would still choose, no matter what the findings, not to re-operate and not to place a WallStent for all of the reasons mentioned above. Thus, we made the decision to initiate oral anticoagulation therapy and continue with the compression stockings. A glimpse of how we might approach a newly diagnosed case of May-Thurner syndrome serves to highlight the teaching points of this case. Although in an adult, we would likely resort to transluminal stenting as a first-choice therapy, we would still choose an operative approach for young, active females of childbearing potential and thereby avoid stenting. However, we would also definitely enter the left common iliac vein at surgery. In each case, this would be beneficial in at least one of two ways. First, in cases with a clearly defined spur on preoperative and intraoperative studies, entering the vein is necessary to perform endovenectomy and patching. Second, in cases with no spur seen on imaging studies, entering the vein provides the means for patch angioplasty, a procedure that should do the most we can to minimize luminal compromise caused by ongoing compression, extrinsic perivenous scarring, or intimal hyperplasia.
Simon et al
953
REFERENCES 1. May R, Thurner J. Ein Gefässporn in der Vena iliaca communis sinistra als wahrscheinliche Ursache der überwiegende linksseitigen Beckenvenenthrombose. Ztschr. Fuer Kreislaufforschg 1956;45:912. 2. Ferris EJ, Lim WN, Smith PL, Casali R. May-Thurner syndrome. Radiology 1983;147:29-31. 3. McMurich JP. Congenital adhesion in the common iliac veins. Anat Record 1906;1:78-9. 4. Alimi YS, DiMauro P, Fabre D, Juhan C. Iliac vein reconstruction to treat acute and chronic venous disease. J Vasc Surg 1997;25:673-81. 5. Lalka SG. Management of chronic obstructive venous disease of the lower extremity. In: Rutherford RB, editor. Vascular surgery. Vol 2. 4th ed. Philadelphia: WB Saunders, 1995; p. 1862-82. 6. Binkert CA, Schoch E, Stuckmann G, et al. Treatment of pelvic venous spur (May-Thurner syndrome) with selfexpanding metallic endoprostheses. Cardiovasc Intervent Radiol 1998;21:22-6. 7. Rilinger N, Görich J, Mickley V, et al. Endovascular stenting in patients with iliac compression syndrome: experience in three cases. Invest Radiol 1996;31:729-33. 8. Berger A, Jaffe JW, York TN, et al. Iliac compression syndrome treated with stent placement. J Vasc Surg 1995;21:510-4. 9. Elson JD, Becker GJ, Wholey M, et al. Vena caval and central venous stenoses: management with Palmaz balloon-expandable intraluminal stents. J Vasc Intervent Radiol 1991;2:215-23. 10. Antonucci F, Salomonowitz E, Stuckmann G, Stiefel M, Largadier I, Zollikofer CL. Placement of venous stents: clinical experience with a self-expanding prosthesis. Radiology 1992;183:493-7. 11. Rösch J, Petersen BD, Lakin PC. Venous stents: indications, technique, results. In: Perler and Becker, editors. Vascular intervention: a clinical approach. New York: Thieme; 1998. p. 705-10. 12. Gray RJ. Central venous stenosis in hemodialysis patients. In: Trerotola SO, Savader SJ, and Durham JD, editors. Venous interventions. Fairfax: The Society of Cardiovascular and Interventional Radiology; 1995. p. 123-35. 13. Semba CP. Central venous stents: an overview. In: Trerotola SO, Savader SJ, and Durham JD, editors. Venous interventions. Fairfax: The Society of Cardiovascular and Interventional Radiology; 1995. p. 1136-51.
Submitted Jul 9, 1998; accepted Apr 19, 1999.