Postoperative management
The final stage in management of PSS varies considerably. Patients often
commence antiplatelet and anticoagulation therapy, with agents including
aspirin and rivaroxaban respectively. Follow-up investigations include
doppler ultrasound and venography to determine venous luminal patency in
terms of blood flow at the lesion site, and to detect any residual
stenosis or re-thrombosis that may require
reintervention.12
Because thoracic outlet decompression in PSS fails to address intrinsic
vessel wall lesions that may arise secondary to chronic anatomical
compression, residual SV lesions that cause stenosis or recurrent
thrombosis remain a particularly distinct cause for
reintervention.3 In cases where persistent venous
stenosis is detected on postoperative imaging, adjunctive percutaneous
transluminal angioplasty (PTA) or stenting is a well-documented approach
to improve long-term clinical outcomes and maintain the re-establishment
of the native luminal diameter.4 Schneider et al. note
that up to 60% of patients persistently exhibit recurrent thrombosis or
SV stenosis following surgical decompression, and that adjunctive
angioplasty in this setting was found to be highly effective. Indeed,
fibroelastic venous wall lesions in patients with PSS may necessitate
balloon inflation pressures exceeding 10 atmospheres (atm) to achieve
successful venous dilation.3, 11
Re-thrombosis in the SV lumen often occurs in the interval between
decompressive surgery and adjunctive intervention, especially in cases
where preoperative endovascular thrombolysis was not carried out, or
full thrombolysis was not achieved. This has led surgeons to advocate
for performing endovascular thrombolysis, decompression, and adjunctive
procedures within a single hospitalisation.3 This
approach would arguably speed up recovery time, and shorten the overall
duration of admission and treatment. As an alternative, Koury et al.
suggest prophylactic SVC filter placement prior to decompressive
surgery, in cases where endovascular or systemic thrombolysis has failed
or is contraindicated, especially when there is a backdrop of
thromboembolic risk. Placement of such a filter at the confluence of the
left and right innominate vein would therefore protect against cerebral,
azygous, or pulmonary embolisation.8
It must be stressed, however, that adjunctive angioplasty or
endovascular stenting does not serve to replace decompressive surgery
-Schneider highlights that PTA in PSS patients who have not undergone
decompressive surgery is especially ineffective.11Though lumen patency may temporarily be maintained by the stent,
anatomical compression during movement easily results in stent fracture
and re-thrombosis of the SV.3
Adjunctive stenting is less effective in patients with chronic PSS
because well-established thrombi typically respond poorly to balloon
dilation as well as endovascular thrombolysis. In such instances, venous
bypass using grafts from the saphenous or femoral veins, or indeed
internal jugular turndown, may be carried out.4