Historical Background
Subclavian-axillary vein thrombosis, also referred to as Paget-Schroetter syndrome or “effort thrombosis,” refers to primary thrombosis of the subclavian vein at the costoclavicular junction. Primary subclavian-axillary vein thrombosis is relatively rare, with a yearly incidence in the United States of 3000 to 6000 cases. A recent analysis suggests that less than 1000 first rib resections are performed for venous thoracic outlet syndrome yearly. This is a disorder of the anterior part of the thoracic outlet region, where the subclavian vein passes through the intersection of the clavicle and first rib ( Fig. 17-1 ), often seen in young, healthy patients who participate in vigorous activity that involves raising the arm above the head.
Paget was the first to describe “gouty phlebitis” of the upper extremity in 1875, which was a spontaneous thrombosis of the subclavian vein. von Schroetter postulated in 1884 that this entity resulted from a direct stretch injury to the vein caused by muscular strain. Hughes termed the condition Paget-von Schroetter syndrome in 1949.
Leaving this condition untreated results in residual upper extremity venous obstruction in up to 78% of cases and persistent symptoms and permanent disability in 41% to 91% and 39% to 68% of cases, respectively. Anticoagulation alone results in “excellent or good” long-term results in only 10 of 35 (29%) patients. Although significant differences exist, most recommend thrombolysis, followed by thoracic outlet decompression, most often by first rib resection. Decompression was initially thought best performed after an interval of a few months, but many now advocate immediate surgery to reduce the risk of rethrombosis. Secondary venous thrombosis is typically associated with a central catheter, with recommended treatment including anticoagulation and catheter removal.
Preoperative Preparation
- •
True effort thrombosis almost always produces acute symptoms, and the patient usually presents to the clinic or emergency department with a swollen, blue, painful arm. Clinical clues include a history of vigorous activity, often with the affected arm overhead, and even if the onset of swelling is acute, a history of intermittent swelling, discoloration associated with activity, or both is common. Patients may have prominent chest wall or shoulder collaterals.
- •
Duplex imaging should be performed to confirm the diagnosis.
- •
If duplex is negative or equivocal, computed tomography or magnetic resonance venography can be considered. The patient with a duplex ultrasound venous thrombosis should be anticoagulated, with intravenous access established in the contralateral extremity.
- •
Success of catheter-directed thrombolytic therapy rapidly decreases from onset of symptoms to intervention. Therefore, although not an emergency, treatment should be initiated within hours to a day or so after diagnosis unless contraindications exist. Although algorithms differ, pharmacologic or pharmacomechanical thrombolysis followed by transaxillary first rib resection during the same admission is an accepted approach. If thrombolysis is planned, pregnancy testing should be performed and renal function should be assessed.
Pitfalls and Danger Points
- •
Pulmonary embolism
- •
Vessel perforation
- •
Bleeding risk after thoracic outlet decompression is increased if surgery is performed within hours to days after thrombolysis.
- •
Venous occlusion while awaiting thoracic outlet decompression may occur in 10% to 33% of patients if surgery is delayed for months, but is uncommon (5%) if surgery is performed within several days of thrombolysis.
Endovascular Strategy
Angiographic Anatomy and Collaterals
- •
The true deep system consists of the paired forearm veins that unite to form the paired brachial veins, surrounding the brachial artery in the antecubital fossa ( Fig. 17-2 ). These vessels are the anatomic analogue of the tibial and popliteal veins in the leg. At the midupper arm or axilla, this system is usually joined by the basilic vein; at the lower border of the teres minor, this becomes the axillary vein; and at the lateral border of the first rib, it becomes the subclavian vein. The deep brachial vein joins the axillary vein in the axilla.
Figure 17-2
Anatomy of the veins of the arm. The basilic veins in the antecubital fossa and brachial vein just medial to it both provide access to the axillary-subclavian vein complex, whereas the cephalic vein does not enter the deep system until the deltopectoral groove is reached.
- •
The superficial system consists of the cephalic vein, which communicates with the deep system at the antecubital fossa and then joins the subclavian vein at the deltopectoral groove, and the basilic vein, which, as noted earlier, joins the deep system in the midupper arm or axilla after penetrating the superficial fascia and axillary sheath.
- •
Two main collateral pathways exist, collectively described as “first rib bypass collaterals,” which become prominent in patients with subclavian-axillary vein thrombosis. The more prominent tend to occur cephalad to the costoclavicular junction and connect branches of the cephalic vein to the external and internal jugular veins, whereas the second pathway consists of branches of the deep brachial veins that connect to veins caudal to the junction, typically branches of the pectoral veins and intercostals ( Fig. 17-3 ).
Figure 17-3
Venogram illustrating the “first rib bypass collaterals” connecting branches of the subclavian vein with the external jugular and jugular veins (arrow 1), pathognomic of hemodynamically significant venous occlusion (arrow 2) at this level.
- •
The presence or absence of these collaterals on venography is a critically important marker for residual obstruction or successful thrombolysis, respectively.
Timing
- •
Thrombolysis—initiation. Catheter-directed thrombolysis is most effective if performed as soon after thrombosis as possible. The success rate nears 100% if initiated within a few days of symptom onset but drops significantly if initiated after 7 to 14 days. In three series, no patient with symptoms persisting for longer than 7, 8, and 10 days, respectively, had successful lysis. The success rate in patients at the University of Rochester with symptoms of less than 14 days’ duration has been 84% over the past decade.
- •
Thrombolysis—duration. Thrombolysis should be continued for approximately 48 hours before concluding that no further clot lysis can be achieved. Recent reports have demonstrated that pharmacomechanical lysis may be highly beneficial using the AngioJet (Medrad Interventional/Possis; Minneapolis, Minn.), EkoSonic (EKOS, Bothell, Wash.), or Trellis (Bacchus Vascular, Santa Clara, Calif.) systems with recanalization of the occluded vein within minutes to hours. If residual thrombus remains, a trial of standard catheter-based lytic infusion can be continued.
- •
Decompression. After clot dissolution, the thoracic outlet must be decompressed to relieve compression at the costoclavicular junction, although the timing of the second procedure has been the subject of debate. It was originally recommended that thoracic outlet decompression be delayed 3 months to allow the vessel to heal and to lessen the risk of surgical complications. However, it was later recognized that rethrombosis occurs in up to one third of patients so treated. Most now recommend that decompression follow thrombolysis as soon as possible—ideally during the same admission. This may result in a somewhat higher complication rate but better long-term success; modern series following this algorithm show long-term symptom-free status in 95% to 100% of patients.
- •
Angioplasty and stenting before bony decompression. After thrombolysis a significant number of patients are shown to have intrinsic venous defects, and essentially all have extrinsic compression at the costoclavicular junction. Angioplasty and even stenting of these patients is tempting, but the costoclavicular junction is unyielding, and angioplasty before decompression will commonly fail. It has been suggested that angioplasty prior to decompression may worsen venous patency by further damaging the vein wall. Stenting of the vein may also be complicated by stent fracture in some, deformation in nearly all, and rethrombosis rates as high as 40%. Stents complicate subsequent repair and therefore should be avoided.
- •
Angioplasty and stenting after bony decompression. It is tempting to perform angioplasty, stenting, or both when residual defects are seen after thoracic outlet decompression. In one recent study stent patency was 64% at 3.5 years in 14 patients who were stented after decompression, compared with 100% at 4 years in 9 patients undergoing angioplasty alone. Although this may simply represent selection of more extensive residual lesions, some evidence suggests that postdecompression balloon angioplasty and observation alone for residual defects yield good long-term results. Anecdotal experience suggests that many “intrinsic” defects result from residual external scarring and that external venolysis can eliminate the need for endoluminal intervention in at least some cases ( Fig. 17-4 ). Molina advocates aggressive direct venous reconstruction at the time of thoracic outlet decompression, which eliminates the need for angioplasty and stenting. Many clinicians simply leave such lesions alone, citing the very high, long-term symptom-free status in almost all cases.
