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