Background

Protamine administration was shown to reduce bleeding after carotid surgery but the role of protamine during peripheral vascular interventions (PVIs) remains unknown. This study evaluates the trend and outcomes of protamine use in the Vascular Quality Initiative (VQI). Our hypothesis is that the use of protamine is associated with decreased bleeding after PVI.

Methods

Patients undergoing elective PVI in the VQI (2016–2020) for peripheral arterial disease were reviewed and the utilization trend for protamine was described. The characteristics of patients undergoing PVI with and without protamine use were compared. After propensity score matching based on the patient's comorbidities, access site, and procedural characteristics, the perioperative outcomes of both groups were compared using multivariable Poisson regression to estimate adjusted rate ratios (aRRs) and 95% confidence intervals (95% CIs).

Results

The total number of patients was 131,618 and patients who received protamine constituted 29.8% of the sample (N = 38,191). After propensity matching, the total number of patients was 94,582, and patients who received protamine constituted 28.8% of the sample (N = 27,275). Protamine use significantly increased during the study period from 5.2 to 22.9%. Before propensity score matching, patients who received protamine were more likely to be white (79% vs. 76.8, P ≤ 0.001), smokers (80.5% vs. 78.5%, P ≤ 0.001), with medical comorbidities including hypertension (88.9% vs. 88.5%, P = 0.074), congestive heart failure (20.5% vs. 19.8%, P = 0.006), and chronic obstructive pulmonary disease (28.2% vs. 26.5%). They were also more likely to be on perioperative medications such as P2Y12 inhibitors (44.3% vs. 45, P = 0.013%) and statin (77.4% vs. 76.5%, P = 0.001) compared to patients who did not receive protamine. After propensity matching, there were no significant differences between the 2 groups. There was a significant decrease in bleeding during procedures where protamine was administered compared to no protamine (2.0% vs. 2.2%) (aRR, 0.89 [95% CI 0.80, 0.98]). Protamine was more likely to be given in procedures complicated by perforation (0.8% vs. 0.5%) (aRR, 1.48 [95% CI 1.24, 1.76]) and less likely to be given during procedures with distal embolization (0.4% vs. 0.7%) (aRR, 0.59 [95% CI 0.49, 0.73]). However, patients receiving protamine had significantly higher cardiac complications (1.4% vs. 1.1%) (aRR, 1.27 [95% CI 1.12, 1.43]). There was no significant difference in mortality between the 2 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.

Varicose veins are commonly due to saphenous vein reflux, but they can manifest more complex venous pathologies. A 45-year-old woman presented with painful leg varicosities and pelvic pain. Duplex examination showed bilateral superficial venous reflux, and, on further interrogation, cross-sectional imaging demonstrated enlarged ovarian veins and nonthrombotic iliac vein compression. Ovarian vein embolization followed by iliac vein stenting and bilateral lower extremity venous ablations and sclerotherapy was performed. After 5 years, she reports no pelvic symptoms and minimal leg symptoms. This case highlights the complex interplay of these venous pathologies and their successful treatment.

Balloon rupture during angioplasty can with calcified or recalcitrant lesions. A 61-year-old woman presented with worsening arm and facial swelling. She had a history of left upper extremity thrombolysis and stenting of the innominate vein 6 years prior. Venography showed severe in-stent stenosis. After crossing the lesion, a 12-mm balloon was inflated, which ruptured at nominal pressure. The balloon became stuck and could not be moved over the wire even after retraction of the sheath. A limited surgical cutdown was performed, and the balloon and the wire were removed together. The ruptured balloon part was found to be everted and circumferentially wrapped around the wire, preventing the wire exchange. After cutting the everted portion of the balloon, the catheter was removed without losing wire access. A high-pressure balloon was subsequently used to treat the lesion successfully. Her symptoms had resolved on follow-up, and the stent remained patent after 6 months.

Objective

Patients with chronic kidney disease (CKD) who undergo peripheral vascular interventions (PVI) with iodinated contrast are at higher risk of post-contrast acute kidney injury (PC-AKI). Carbon dioxide (CO₂) angiography can reduce iodinated contrast volume usage in this patient population, but its impact on PC-AKI has not been studied. 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 glomular filtration rate <45 ml/min/1.73 m²) treated for peripheral arterial disease were included. Propensity matching and multivariate logistic regression 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. Compared with patients treated without CO₂, patients who underwent CO₂ angiography were younger and less likely to be women or White, and more likely to have poor renal function, diabetes, cardiac comorbidities, and present with tissue loss. Propensity matching yielded well-matched groups with 4472 patients in each group. The procedural details after matching demonstrated 50% reduction in the volume of contrast used (32±33 vs 65±48 mL; P < .01). PVI with CO₂ angiography was associated with lower rates of PC-AKI (3.9% vs 4.8%; P = .03) and cardiac complications (2.1% vs 2.9%; P = .03) without a significant difference in technical failure or major/minor amputations. Low contrast volumes (≤50 mL for CKD3, ≤20 mL for CKD4, and ≤9 mL for CKD5) are associated with reduced risk of PC-AKI (hazard ratio, 0.59; P < .01).

Conclusions

CO₂ angiography reduces iodinated contrast volume usage during PVI and is associated with decreased cardiac complications and PC-AKI. CO₂ angiography is underutilized and should be considered for patients with advanced CKD who require endovascular therapy.