In a retrospective review of over 600 patients who underwent iliac vein stent placement, the development of back pain was found to be unrelated to stent type, diameter, length or covered vein territory.
Chloe Snow (Greenbelt, USA) and colleagues share this and other findings in a recent Phlebology paper. The review was a joint investigation by researchers at Greenbelt’s Center for Vein Restoration, to which Snow is affiliated, and the Center for Vascular Medicine, also in Greenbelt.
Snow et al write in their introduction that endovascular stenting is the standard of care for the management of symptomatic chronic venous obstruction. However, they note that the increased radial resistive force and longer lengths of nitinol stents often used have “led to questions over persistent postoperative back pain”. The purpose of this investigation, therefore, was to assess the incidence and severity of postoperative back pain associated with nitinol stents compared to Wallstents (Boston Scientific).
The researchers performed a retrospective review of data from the Center for Vascular Medicine, assessing patient demographics and preoperative, one-week, three-, six- and 12-month visual analog pain scores (VAS) for back pain, stent type, diameter, length, and vein locations.
In the period April 2014–November 2021, a total of 627 patients—comprising 412 women and 215 men—were assessed for the presence of postoperative back pain after an initial iliac vein stent placement. The authors detail that the stents utilized were Wallstents (n=114), Venovo (BD; n=342) and Abre (Medtronic; n=171). The most common nitinol stent diameter and lengths were 14mm, 16mm and 120mm, respectively, they add, noting a p-value of ≤0.03.
The Venovo venous stent was granted Food and Drug Administration (FDA) premarket approval in 2019. BD reported at the time that theirs was the first stent indicated to treat iliofemoral venous occlusive disease. The previous year, one-year results from the prospective, multicenter, single-arm VERNACULAR trial had been shared, demonstrating the safety and effectiveness of Venovo for the treatment of symptomatic iliofemoral venous outflow obstruction.
In 2020, Medtronic announced that the Abre venous self-expanding stent system had received FDA approval to treat venous outflow obstruction. The approval was based on 12-month results from the ABRE clinical study, which assessed the safety and effectiveness of the Abre stent in patients with iliofemoral venous outflow obstruction.
Results
Snow and colleagues report in Phlebology that the incidence of back pain at one week was 66%, occurring in 411 out of the 627 patients assessed in the review.
They add that VAS scores at one week and one, three and six months postoperatively were the following: Wallstents 2.6±3 (n=66), 1.7±2.6 (n=43), 0.7±2 (n=51), and 0±0 (n=27); Abre 3.5±3 (n=130), 3.8±3 (n=19), 1.2±2.5 (n=12), and 1±2 (n=5); and Venovo 2.5±3 (n=216), 2.4±3 (n=70), 0.9±2 (n=68), and 0.6±1.7 (n=49).
The authors state that there was no difference in the severity of back pain at any time point (p≥0.99) and that the development of back pain was unrelated to stent type, diameter, length or covered vein territory.
In their conclusion, Snow et al reiterate that postoperative back pain was observed in 66% of patients at one week, and that the average pain score at one week for the entire cohort was three, which declined to less than one at one month. Furthermore, they found that no difference in the severity of back pain between groups was observed at any time point, and that the development of back pain is unrelated to stent type, diameter, length or covered vein territory.
