Protamine administration was shown to reduce bleeding after carotid surgery, but the role of protamine during peripheral vascular interventions (PVI) remains unknown. This study evaluates the trend and outcomes of protamine use in the Vascular Quality Initiative. Our hypothesis is that the use of protamine is associated with decreased bleeding after PVI.
Patients undergoing elective PVI in the Vascular Quality Initiative (2016-2020) for peripheral arterial disease were reviewed and use trend for protamine was derived. The characteristics of patients undergoing PVI with and without protamine were compared. After propensity matching based on patient as well as access site and procedural characteristics, the perioperative outcomes of both groups were compared.
A total of 92,120 PVI procedures were reviewed and 29.6% (n = 27,272) received protamine (Table). Protamine use significantly increased during the study period from 5.2% to 22.9%. (Figure). Patients receiving protamine were more likely to be White (78.9% vs 76.6%; P < .001), Hispanic (6.5% vs 5.9%; P = .003), and smokers (80.5% vs 78.4%; P < .001). Patients treated with protamine were more likely to have congestive heart failure (20.5% vs 19.8%; P = .006), chronic obstructive pulmonary disease (28.2% vs 26.5%; P < .001), diabetes mellitus (53.3% vs 54.4%; P = .002), and were more likely to be on aspirin (73.4% vs 73.6%; P = .596), anticoagulants (19.2% vs 18.4%; P = .005), statins (77.4% vs 76.5%; P = .001), and P2Y12 inhibitors (44.3% vs 45%; P = .013). After propensity matching, there was no significant difference in baseline characteristics. There was a significant decrease in bleeding during procedure where protamine was administered compared with no protamine (2% vs 2.2%; P = .032). Protamine was more likely to be given in procedures complicated by perforation (0.75% vs 0.52%; P < .0001) and less likely to be given during procedures with distal embolization (0.4% vs 0.7%; P < .0001). However, patients receiving protamine had significantly higher myocardial infarction (0.5% vs 0.4%; P = .002) and cardiac complications (1.4% vs 1.1%; P < .001). There was no significant difference in mortality between the two groups.
Protamine use is associated with decreased perioperative bleeding but increased cardiac complications. Protamine should be selectively administered to patients at high risk of bleeding during PVI.
Patients with chronic kidney disease (CKD) who undergo peripheral vascular interventions (PVI) with iodinated contrast are at higher risk of postcontrast acute kidney injury (PC-AKI). CO2 angiography can reduce iodinated contrast volume usage in this patient population, but its impact on PC-AKI has not been studied. This article examines the use of CO2 angiography during PVI in the VQI. We hypothesize that CO2 angiography is associated with a decrease in PC-AKI in patients with advanced CKD.
The Vascular Quality Initiative PVI dataset from 2010 to 2021 was reviewed. Only patients with advanced CKD (estimated glomerular filtration rate of <45 mL/min/1.73 m2) treated for PAD were included. Propensity matching based on demographics, comorbidities, CKD stage, and indications were used to compare the outcomes of patients treated with and without CO2.
There were 20,706 PVIs performed in patients with advanced CKD and only 22% utilized CO2 angiography. Patients who underwent CO2 angiography were younger and less likely to be women or white. However, they were more likely to have more advanced CKD stage, diabetes, and cardiac comorbidities, and be treated for tissue loss compared with patients treated without CO2. Propensity matching yielded 2 well-matched groups with 4396 patients each (Table I). The procedural details after matching demonstrated 50% reduction in the volume of contrast used (32.1 mL vs 63.4 mL; P < .001). PVI with CO2 angiography was associated with lower rates of PC-AKI (3.8% vs 5.1%; P = .01) and cardiac complications (2.1% vs 2.9%; P = .03) without a significant difference in technical failure rates or major/minor amputations (Table II).
CO2 angiography reduces contrast volume usage by 50% during PVI and is associated with decreased cardiac complications and PC-AKI. CO2 angiography is underutilized and should be considered for endovascular treatment of PAD in all patients with advanced CKD.
Endovenous therapy serves as the preferred treatment for patients with May–Thurner syndrome (MTS) who have significant symptoms. While stenting for MTS generally yields better results than for postthrombotic syndrome, it remains unclear whether the severity of stenosis specifically in MTS influences these outcomes. This study aims at assessing the effect of the degree of stenosis on endovascular therapy for MTS.
The retrospective study included 73 patients who presented for deep venous stenting of the lower limb at a tertiary center between 2018 and 2022. Based on the intravascular ultrasound (IVUS) use, patients were divided into two groups according to degree of stenosis: 50%–80% and >80% stenosis. Both groups were compared regarding demographics, clinical presentations, procedural details, and postoperative outcomes.
Significant >80% stenosis was detected in 45.2% of cases. There was no significant difference regarding demographics and comorbidities except for body mass index (BMI) as patients with >80% stenosis were more likely to have higher BMI (P = 0.05). Patients with >80% stenosis were more likely to have a prior history of DVT (21.2% vs. 5%; P = 0.036). There was no statistical difference in the clinical picture of both groups except for higher rates of active venous ulcer in patients with >80% stenosis (21% vs. 5%: P =0.001). Patients with 50%–80% stenosis were more likely to present with atypical varicosities (50% vs. 21%; P = 0.011). Patients with >80% stenosis were more likely to have venographic features of stenosis as pelvic collateral and ascending lumbar veins (P = 0.0007 and P < 0.0001, respectively). After a mean clinical follow-up of 414.6 ± 587.5, primary patency was higher for the 50%–80% stenosis, 90.9% versus 74.4% (Log-rank test = 0.012).
The severity of iliac vein stenosis/compression is associated with more advanced clinical presentations and more venographic signs of collateralizations. IVUS serves as a more sensitive tool than computed tomography venography in detecting left common iliac vein critical stenosis. More than 80% can serve as a proper cutoff point for critical venous stenosis that warrants more aggressive therapy and closer follow-up. A critical degree of stenosis was associated with lower patency rates when compared to 50%–80% stenosis.
This study aims to compare the immediate and mid-term outcomes of subintimal angioplasty (SIA) of chronic total occlusions (CTOs) of superficial femoral artery (SFA) versus popliteal artery (PA) and to identify possible predictors of loss of limb-based patency (LBP).
This is a retrospective analysis of chronic lower-limb ischemia (CLI) patients (Rutherford classes 3–6) presenting with CTO of SFA or PA treated by SIA and selective stenting in the period 2018 to 2021. Immediate outcomes were compared between the SFA and PA groups, including technical success, perioperative complications, and 30-day major amputation and mortality rates. Mid-term outcomes for technically successful procedures included limb-based patency (LBP), wound healing rate, amputation-free survival (AFS), and major adverse limb events (MALEs).
A total of 450 CLI patients underwent SIA of CTO at the SFA (n=260, 57.8%) and the PA (n=190, 42.2%). The indication for revascularization was chronic limb-threatening ischemia in 80.8% of SFA group and 84.2% of PA group. Technical success rate was higher in the PA group compared to the SFA group (96.3% vs 91.2%; p=0.03). The 30-day amputation rates were comparable between the SFA and PA groups (7.7% vs 6.8%, p=0.7, respectively). No perioperative mortality or systemic major complications occurred in the present study. Kaplan-Meier estimate of the 1-year rates were significantly better for SFA group regarding LBP (82% for SFA group vs 43% for PA group, p=0.006), AFS (88% vs 64%, p=0.02), and wound healing (79% vs 58%, p=0.027), respectively. The number of runoff vessels was the only factor associated with loss of LBP (hazard ratio [HR], 0.055; 95% confidence interval [CI]: 0.001–3.020, p=0.039).
Subintimal angioplasty is an effective and safe endovascular treatment option of CTO at SFA and PA with satisfactory immediate outcomes. The mid-term outcomes, however, are better for SFA lesions in terms of improved LBP, AFS, and wound healing rates.
The role of iliac vein stenosis (IVS) in the development of deep vein thrombosis (DVT) is poorly understood. This study determines the incidence of IVS in patients diagnosed with DVT and assesses its impact on presentation and outcomes. Our hypothesis is that the presence of IVS increases the risk of long-term ipsilateral DVT recurrence.
A retrospective study of the electronic medical records of consecutive adult patients treated for lower extremity DVT was performed. Only patients with cross-sectional imaging (computed tomography or magnetic resonance with intravenous contrast) were included. Patient and DVT characteristics were recorded. Cross-sectional imaging was reviewed for the presence or absence of ipsilateral IVS (≥50%). Patients were divided into 2 groups based on the presence or absence of IVS to compare characteristics and outcomes. Subgroup analyses on patients with provoked DVT, cancer-related DVT, and unprovoked DVT were performed.
There were 548 patients with DVT and 32% had evidence of ipsilateral IVS on cross-sectional imaging. There were no significant differences in baseline characteristics or treatment methods between the 2 groups. There was a trend toward patients with IVS having less incidence of pulmonary embolism on presentation (22.9% vs. 29.7%, P = 0.1) but that difference did not reach statistical significance in the overall comparison. Subgroup analysis in patients with cancer-related DVT (n = 227) showed that patients with IVS were significantly more likely to develop ipsilateral recurrent DVT compared to patients with no IVS (12.9% vs. 4.5%, P = 0.045). Patients with unprovoked DVT with IVS had significantly lower pulmonary embolism on presentation than patients with unprovoked DVT without IVS (24.2% vs. 39.8%, P < 0.03).
Ipsilateral ≥50% IVS is present in approximately a third of patients presenting with DVT. The presence of IVS seems to play a differential role in ipsilateral DVT recurrence and prevention of pulmonary embolization in different groups of patients presenting with DVT.
Do you have any questions? 
