Objectives

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.

Methods

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.

Results

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.

Conclusions

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.

Objectives

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.

Methods

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.

Results

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).

Conclusions

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.

Objectives:

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).

Methods:

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).

Results:

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).

Conclusions:

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.

Objectives

Intravascular ultrasound (IVUS) is the preferred method for diagnosing iliocaval deep venous stenosis (DVS). Preoperative cross-sectional imaging (CSI) is used to screen for DVS in selected patients, but there is no current standardization of radiological measurement and reporting. Our hypothesis is that discordance in CSI interpretation between vascular specialists and radiologists could impact patient care and outcomes.

Methods

A retrospective analysis of patients who underwent deep venous stenting after CSI for chronic venous symptoms was performed. Vascular specialists reviewed all CSI scans for significant DVS (≥50%) and compared them with the official radiologist reports. Patients were divided into two groups based on the interpretation of CSI: discordant reading (DR) and concordant reading (CR). The DR group consisted of cases where the vascular specialists' interpretation differed from that of the radiologist, whereas the CR group included cases where there was agreement.

Results

Ninety-three patients underwent stenting for DVS with preoperative CSI, and 27% had DR. There were more female patients in the CR group, with no other demographic differences. There were significantly more patients in the CR group with a history of anticoagulation use than patients with DR. There was no difference in presenting symptoms based on CEAP clinical classification between the two groups. MRI was the most used CSI modality (64.5%), with no difference between the groups. There was a significantly higher proportion of patients with common iliac vein (CIV) stenosis in the DR group compared with the CR group reaching up to 96%, suggesting that the interpretation of significant CIV stenosis is the source of most discordances. IVUS revealed significant iliac vein stenosis in the majority of patients (96.8%) regardless of CSI. After a mean follow-up of 2.5 years, both groups had similar symptomatic relief (95% vs 98%; P = .5) (Table) and primary patency (Fig).

Conclusions

This study reveals significant discordance between vascular specialists and radiologists in the interpretation of CSI of DVS related mostly to measurement of the CIV. Even though patients had excellent outcomes in both groups, standardization of measurement and reporting of DVS on CSI could improve patient selection for therapy.

Objective

Venous stent migration to the heart is a potentially life-threatening complication and has recently led to device withdrawal from the market. A review of the literature was conducted to better characterize factors associated with this serious complication and its management.

Methods

A systematic review of the literature using the term “venous stent migration” was performed. All articles describing patients with this complication were reviewed. Patient characteristics, indication, time to discovery of migration, and management were summarized. Venous stents that migrated from the lower body to the heart were compared with venous stents that migrated from the upper body.

Results

A total of 73 papers with 84 patients reported venous stent migration to the heart or through the heart to the pulmonary artery. The number of papers reporting this phenomenon increased from 6 in the period of 1991-1995 to 20 in the period of 2016-2020 (Fig). The incidence of venous stenting migration varied mostly between 0.4% and 4.5%. Patients with migration from lower body were significantly younger (49.1 vs 56.9, P = .05). There were significant differences in indications for stenting with most patients with upper body migration being treated for dialysis access maintenance while patients with lower body migration treated for venous insufficiency/thrombosis (P < .001). Of the cases of venous stent migrations from lower body, 20% (8 of 41) were due to Nutcracker syndrome as an indication. There was no difference in stent characteristics in terms of type (86% self-expanding) or size. The implanted stents were relatively small (mean diameter = 14 mm) and short (mean length = 4.5 mm). After venous stent migration, most patients presented with symptoms (60%), with no difference in mean time to presentation. Patients with upper body stent migration were significantly more likely to be treated with no surgery or endovascular intervention compared with those with lower body stent migration, which was more likely to be treated with an open surgery (P = .014) (Table). At least 12% (n = 3 of 25) of patients requiring open surgery required valve replacement. The overall mortality related to stent migration to the heart was 3.6% (n = 3 of 84).

Conclusions

There is a rise in reporting of venous stent migration to the heart in the literature. Stent migration from the lower body seems to be less amenable to endovascular therapy compared with migration from the upper body. This complication carries significant mortality likely in excess of 3.6% because of underreporting.