Paget-Schroetter syndrome: An unfamiliar cause of upper-limb deep venous thrombosis.

Paget-Schroetter syndrome (PSS), which is also called "effort thrombosis," is a venous variant of thoracic outlet syndrome. We report a rare case of upper-limb deep venous thrombosis (ULDVT) in a young patient who was later diagnosed as PSS. PSS is a rare cause of ULDVT, and it is usually seen in young adults who are involved in strenuous physical activity. PSS is either due to anatomical abnormality of the thoracic outlet or due to repeated microtrauma to the endothelium of the subclavian/axillary vein. Clinically, the patient usually presents with signs and symptoms of ULDVT. Noninvasive Doppler ultrasonography is the initial investigation of choice, but computerized tomography and digital subtraction angiography are the gold standards for diagnosis. Treatment consists of therapeutic anticoagulation, catheter-directed thrombolysis, first rib resection, and postoperative oral anticoagulation. Although the PSS less likely causes pulmonary embolism, it can contribute to postthrombotic syndrome. PSS is a rare and distinct clinical entity, and most emergency care or primary care physicians are unaware of this condition. PSS requires rapid diagnosis, timely thrombolysis, and prompt referral to a vascular and thoracic surgeon. Copyright:

INTRODUCTION

The incidence of upper-limb deep vein thrombosis (ULDVT) currently accounts for about 1%−4% of all DVT cases.[1] ULDVT is uncommon as compared to lower-limb DVT because of relatively high blood flow rates, less venous walls, gravitational advantage, and less stasis in the upper-limb venous system.[1] About 70%−80% of cases of ULDVT are due to underlying causes such as indwelling hardware (central venous catheter, ports, and pacemakers), occult or overt malignancy, and acquired or congenital thrombophilic state called “secondary ULDVT.” The remaining 20%−30% of cases are idiopathic and are referred to as “primary ULDVT.”[1] We report an unfamiliar clinical entity Paget−Schroetter syndrome (PSS), which is also called “effort thrombosis” in a patient who presented with ULDVT.

CASE REPORT

A 34-year-old male patient, who was a regular gymnasium trainee and nurse by occupation, was admitted to our hospital with complaints of swelling, heaviness, and discoloration of the skin in the left upper limb for 1 day. Although there was no significant history of trauma, clinical features developed 6−8 h after a moderate-intensity workout in the gym. He was a nonsmoker, nonethanolic, and with no other significant medical history. On examination, he was found to have athletic built with a weight of 78 kg and a height of 178 cm (body mass index of 24.7 kg/m2). His vitals were temperature 37.6°C, pulse rate 100 beats/min, blood pressure 107/68 mmHg, respiratory rate 18 breaths/min, and oxygen saturation 99% on room air. Local examination of the left upper limb revealed obvious swelling in the left upper limb, dusky appearance of the skin, and no neurological deficit. Other systemic examinations were normal. His complete blood count, renal, liver function, and coagulation profile all were within normal limits. Thrombophilia was screened by ordering protein C, protein S, antithrombin-III, activated protein resistance, factor V Leiden, and antiphospholipid antibodies which were within acceptable limits. Ultrasonography with Doppler study of the left upper limb was done which was suggestive of DVT in the left axillary and subclavian vein. This was later confirmed by computed tomography (CT) venography which also showed the extension of thrombus from the left subclavian vein into an innominate vein [Figure 1]. CT of the neck, chest, and abdomen was also done to rule out any occult malignancy. Depending on clinical presentation, laboratory, and radiological investigation, he was diagnosed as a case of PSS. He was started with therapeutic anticoagulation enoxaparin 80 mg subcutaneously twice daily. Subsequently, digital subtraction angiography (DSA) and catheter-directed thrombolysis with alteplase was attempted over the next 24 h [Figure 2]. Postthrombolysis, the limb venogram was repeated which was suggestive of stenosis in distal subclavian vein and overlapping the first rib. Therefore, balloon-assisted angioplasty of stenotic subclavian vein was performed which resulted in moderate vessel opening with residual stenosis due to overlapping first rib and mild residual filling defect [Figures 3 and 4]. Eight days after thrombolysis, first rib resection was done. The operative findings were fibrotic bands around the left subclavian vein. The patient was discharged on the 7th postoperative day in stable condition on non-Vitamin K-dependent oral anticoagulant apixaban 10 mg once a day (direct factor Xa inhibitor). The patient was followed after 2 weeks and showed satisfactory resolution of all symptoms.

Figure 1

Computed tomography venography showing thrombosis in the left subclavian vein (T)

Figure 2

Digital subtraction angiography showing thrombus in the left subclavian vein (T) and catheter for local thrombolysis (C)

Figure 3

Limb venography showing balloon angioplasty (B)

Figure 4

Limb venography showing partial thrombosis and F (fibrous band)

DISCUSSION

PSS was independently described by James Paget in 1875 and von Schroetter in 1884, but later English surgeon Hughes renamed it as PSS in 1949.[2] PSS is more commonly seen in younger patients (in a second or third decade) with a male-to-female ratio of 2:1.[3] The incidence ranges from 1 to 2 per 100,000 individuals per year. It is more commonly encountered on the active right side.[3] PSS is a venous variant of thoracic outlet syndrome (TOS). TOS constitutes a group of diverse disorders that result in compression of the neurovascular bundle exiting the thoracic outlet.[4] The subclavian/axillary vein enters the chest through a narrow space between the first rib and the clavicle which is further reinforced by scalenus anticus muscle posteriorly and subclavius muscle and tendon anteriorly. This relation between bones and muscle to vein creates a “nutcracker-like” compression effect on the vein.[3] There are two proposed theories in the etiopathogenesis of PSS. First, the microtrauma to the endothelium and activation of the coagulation cascade occur following sporting activities such as wrestling, playing ball, gymnastics, and swimming because these activities involve vigorous and sustained upper-extremity movements such as retroversion, hyperabduction, and extension of the arm. Thrombosis may result from a single insult or the cumulative effect of chronic insult. Second, anatomical abnormalities involve the thoracic outlet (cervical rib, congenital bands, hypertrophy of scalenus tendons, and abnormal insertion of the costoclavicular ligament) which reduces costoclavicular space and leads to decrease mobility, compression, and stasis in blood flow and increases the susceptibility of the vein to trauma following vigorous arm movements.[35] Some authors also suggest the role of thrombophilia state in the pathogenesis of PSS, but this correlation is not conclusive.[6] Clinically, ULDVT due to PSS is always symptomatic as compared to secondary ULDVT.[5] In 80%−85% of cases, patients present within 24 h after vigorous upper-limb activity, but this correlation to activity is not always found, and in about 15%−20% of patients, no history of inciting event is present.[35] Patients usually complain of sudden onset of the blue, swollen, heavy, painful arm. On examination, a prominent venous pattern consists of dilated superficial collateral veins over the upper arm (Urschel's sign), the base of the neck, and the anterior chest wall.[35] Ultrasonography with color Doppler is the investigation of choice in the initial setting[7] as it is noninvasive, rapid, and easy to perform. Radionuclide magnetic resonance (MR) and CT venography are superior to ultrasonography.[5] MR venography has the highest sensitivity (100%) and specificity (97%).[8] These tests are the second line and reserved for patients with a high clinical probability of PSS and negative ultrasound. DSA-contrast venography is the gold standard for diagnosis.[5] It is not always indicated but done as a part of a multimodal treatment strategy to deliver catheter-directed thrombolysis. In addition to the abovementioned imaging study, all patients should be investigated for inherited and acquired thrombophilic states. This will help to predict postoperative complications and recurrence rates and determine the need for long-term anticoagulation.[56] In the past, PSS was managed with limb elevation and anticoagulation alone, but now, most of the researchers recommend aggressive and invasive treatment strategy. These consist of local catheter-directed thrombolysis with newer fibrinolytic such as alteplase and reteplase for 24−48 h and thoracic outlet decompression by first rib resection depending on the duration of symptoms.[359] If the duration of symptoms is <2 weeks, the first step is to attempt venography and local thrombolysis and to repeat venography to see the success of thrombolysis. If the vein is recanalized completely, it is recommended to proceed with early first rib resection. However, if thrombolysis yields partial recanalization of the vein, in addition to resection of rib, either open repair of vein or angioplasty with or without stenting is indicated. If the duration of symptoms is more than 2 weeks, these patients are less likely to be recanalized with local thrombolytic therapy and they will require venous reconstruction or venous bypass along with first rib resection.[3] Postprocedure anticoagulation is indicated in all patients irrespective of the treatment strategy.[35] Complications of PSS include pulmonary embolism (PE), postthrombotic syndrome (PTS), and recurrent thrombosis.[35] The incidence of PE after PSS is 6%−15%.[5] PTS is more frequent with an incidence of around 45% as compared to PE, and it is a major contributor to the morbidity associated with the disease. PTS is characterized by pain, heaviness, swelling, and residual deformity which can be troublesome in young active patients.[5] Prognosis is good with the combination of local catheter-directed thrombolysis and thoracic outlet decompression, especially when patients report early and PSS is diagnosed and managed promptly.[35]

CONCLUSION

PSS is an unusual cause of ULDVT. PSS has entirely different pathogenesis, clinical presentation, and treatment strategy compared to secondary ULDVT or lower-limb DVT. Although the PSS less likely causes PE, it can cause PTS contributing to morbidity in the form of residual deformity in young active patients. Prognosis is usually good with multimodal treatment modalities. Therefore, it can be concluded that PSS requires rapid diagnosis, timely thrombolysis, and prompt referral to a vascular and thoracic surgeon for thoracic outlet decompression.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Research quality and ethics statement

This case report did not require approval by the Institutional Review Board / Ethics Committee. The authors followed applicable EQUATOR Network (http://www.equator-network.org/) guidelines, specifically the CARE guideline, during the conduct of this research project.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.