Nathan L. Liang

Comparative Outcomes of Ultrasound-Assisted Thrombolysis and Standard Catheter-Directed Thrombolysis in the Treatment of Acute Pulmonary Embolism

Objectives: The objective of this study was to compare the outcomes of patients undergoing ultrasound-accelerated thrombolysis (USAT) and standard catheter-directed thrombolysis (CDT) for the treatment of acute pulmonary embolism (PE). Methods: The records of all patients in our institution having undergone CDT or USAT for massive or submassive PE from 2009 to 2014 were retrospectively reviewed. Standard statistical methods were used to compare characteristics and to assess for longitudinal change in outcomes. Results: Sixty-three patients, 27 CDT and 36 USAT, were treated for massive (12.7%) or submassive (87.3%) PE. Of which, 96.8% were treated for bilateral PE. Baseline patient characteristics did not differ between the 2 treatment groups. There was no difference in total dose of lytic administered (CDT: 23.2 ± 13.7 mg; USAT: 27.5 ± 12.9 mg; P = .2). Two patients in the CDT and 1 in the USAT groups required conversion to surgical thrombectomy (CDT: 7.4%; USAT: 2.8%; P = .6). Rates of major and minor bleeding complications (CDT: 11.0%; USAT: 13.9%; P = .8) did not differ significantly between the CDT and USAT groups. Estimated survival at 90 days was 92% for CDT and 93% for USAT and 82% at 1 year for both groups (P = .8). All echocardiographic parameters improved significantly from baseline to 1-year follow-up, but quantitative improvement did not differ between groups. Conclusion: This study suggests no statistical differences in clinical and hemodynamic outcomes or procedural complication rates between USAT and standard CDT for the treatment of acute PE. Prospective studies are needed to further evaluate comparative and cost-effectiveness of different interventions for acute massive and submassive PE.

Catheter Interventions for Pulmonary Embolism: Are They Really that Safe?

Catheter-directed interventions (CDI) are increasingly used for the treatment of acute pulmonary embolism (PE), despite the scarcity of comparative prospective data. Although systemic thrombolysis improves the PE hemodynamic profile, this comes at the cost of a high major bleeding risk assumed to be negligible if CDIs are used. Mostafa et al are to be commended for thismuch needed review of the studies that summarize the technologies available for CDIs and the complications associated with this technique. The purpose of this letter is to call attention to the safety profile of CDIs. The conclusion of Mostafa et al that the pooled major bleeding complication rate of ultrasound assisted thrombolysis (USAT) is “below 1%” is a significant underestimation of the published data, given the variable definition of major bleeding as reported in each study. To be consistent with the reporting of major bleeding, a Prospective, Single-arm, Multi-center Trial of EkoSonic Endovascular System and Activase for Treatment of Acute Pulmonary Embolism (SEATTLE II) study reported a 15/ 150 (10.0%) and not 1/150 (0.7%) major bleeding rate. Apart from the 1 patient requiring vasopressor support,

Equivalent Outcomes Between Ultrasound-Assisted Thrombolysis and Standard Catheter-Directed Thrombolysis for the Treatment of Acute Pulmonary Embolism.

Methods: Patients with VLU were subdivided into INFL (n 1⁄4 32) or GRAN (n 1⁄4 16) on the basis of the clinical examination of an active INFL wound with sloughing, tissue necrosis, lack of granulating ulcer base, or active GRAN wound base. CVUWF was collected by applying cotton gauze to the ulcer bed until saturated. The CVUWF was transferred in a collecting tube without additives or antiproteases and centrifuged at 10,000 g, and the supernatant was stored at 80 C. Aliquots were then tested in duplicate, and the concentrations of MMP-1 (collagenase 1), MMP-2 (gelatinase A), MMP-3 (stromelysin 1), MMP-7 (matrilysin 1), MMP-8 (collagenase 2), MMP-9 (gelatinase B), MMP-10 (stromelysin 2), MMP-12 (metalloelastase), and MMP-13 (collagenase 3) were quantified by multiplex enzyme-linked immunosorbent assay. MMP concentration was expressed in pg/mL as mean 6 standard error of the mean. To determine pain in INFL and GRAN wounds, a visual analog scale was used. Nonparametric statistical tests were used to determine significance at P < .05. Results: The mean age of the INFL was 69.1 6 14.8 years (aged 4391 years), and the GRAN was 77.8 6 6.5 years (aged 65-85 years). The CVUWF from INFL VLU contained significantly higher levels of MMP2, MMP-9, and MMP-12, that is, characteristic of MMPs in a degrading wound; however, the CVUWF from GRAN VLU contained higher levels of MMP-1, MMP-7, and MMP-13, which are characteristic MMPs of a reparative and fibroblast proliferating wound (Table). There were no statistically significant differences in MMP-3, MMP-8, or MMP-10. Visual analog scale score of INFL VLU was significantly higher than that in GRAN VLU (5.0 6 0.24 vs 3.4 6 0.29; P 1⁄4 .0003). Conclusions: These data suggest the identification of different kinds of VLU microenvironments consisting of a harmful inflammatory phase with high expressionof degradingMMPsand a reparativemicroenvironment dominated by a granulating phase with expression of proliferating and remodeling MMPs. Consistent with INFL VLU stage, higher pain levels were observed. These results suggest a potential use of MMP panels as useful biomarkers to determine VLU wound condition and to guide best medical treatment. Further researchonMMPs inCVUWFis needed todetermine howMMPprofiles change in the microenvironment of healing vs nonhealing VLUs.

Midterm outcomes of catheter-directed interventions for the treatment of acute pulmonary embolism

Objective The hemodynamic benefits of catheter-directed thrombolysis for acute pulmonary embolism have not been clearly defined beyond the periprocedural period. The objective of this study is to report midterm outcomes of catheter-directed thrombolysis for treatment of acute pulmonary embolism. Methods Records of all patients undergoing catheter-directed thrombolysis for high- or intermediate-risk pulmonary embolism were retrospectively reviewed. Endpoints were clinical success, procedure-related complications, mortality, and longitudinal echocardiographic parameter improvement. Results A total of 69 patients underwent catheter-directed thrombolysis (mean age 59 ± 15 y, 56% male). Eleven had high-risk and 58 intermediate-risk pulmonary embolism. Baseline characteristics did not differ by pulmonary embolism subtype. Fifty-two percent of patients underwent ultrasound-assisted thrombolysis, 39% standard catheter-directed thrombolysis, and 9% other interventional therapy; 89.9% had bilateral treatment. Average treatment time was 17.7 ± 11.3 h with average t-Pa dose of 28.5 ± 19.6 mg. The rate of clinical success was 88%. There were two major (3%) and six minor (9%) periprocedural bleeding complications with no strokes. All echocardiographic parameters demonstrated significant improvement at one-year follow-up. Pulmonary embolism-related in-hospital mortality was 3.3%, and estimated survival was 81.2% at one year. Conclusions Catheter-directed thrombolysis is safe and effective for treatment of acute pulmonary embolism, with sustained hemodynamic improvement at one year. Further prospective large-scale studies are needed to determine comparative effectiveness of interventions for acute pulmonary embolism.

Comparative effectiveness of anticoagulation on midterm infrainguinal bypass graft patency

Objective: Therapeutic anticoagulation (AC) is used clinically for prolongation of infrainguinal bypass patency, but evidence for the efficacy of this practice is conflicting. The objective of our study was to determine the association of AC with bypass graft primary patency. Methods: Clinical and comorbid data of patients undergoing infrainguinal bypass grafts to a below‐knee target with at least 1 year of follow‐up performed from 2003 to 2015 were obtained from the Society for Vascular Surgery Vascular Quality Initiative. Inverse propensity of treatment‐weighted Cox regression was used to assess the effect of AC on patency in the total cohort while adjusting for clinical, operative, and comorbid differences between treatment groups. Subgroup analyses of distal targets and conduit type were performed. Perioperative complications were analyzed using propensity‐weighted logistic regression. Results: We identified 7612 bypass grafts with intact 1‐year follow‐up information from 2003 to 2015. The mean age was 67.5 ± 11.2 years; 30.5% (n = 2320) were female, and 28.6% (n = 2165) were discharged on therapeutic AC. The anticoagulated group had a higher rate of tibial, ankle, and pedal targets (52.1% [n = 1127] vs 47.6% [n = 2269]; P < .001), had a greater use of non‐single‐segment vein conduits (44.3% [n = 951] vs 26.5% [n = 1426]; P < .001), and was more likely to have had a previous ipsilateral bypass (27.2% [n = 589] vs 14.7% [n = 794]; P < .001) or stent (25.4% [n = 550] vs 20.9% [n = 1130]; P < .001). Estimated unadjusted primary patency was 70.8% ± 0.6% at 1 year and lower for anticoagulated bypasses (66.9% ± 1.2% vs 72.4% ± 0.7%; P < .001). Propensity‐weighted analysis showed no significant association of AC with primary patency in the overall cohort (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.86‐1.11; P = .8) but demonstrated a trend toward improvement of primary patency in those with a non‐single‐segment vein conduit to a below‐knee popliteal target (HR, 0.85; 95% CI, 0.80‐1.02; P = .09). AC was associated with significantly improved secondary patency in those with prosthetic bypass grafts (HR, 0.77; 95% CI, 0.62‐0.96; P = .02) or prosthetic bypasses to an infrapopliteal target (HR, 0.72; 95% CI, 0.54‐0.97; P = .02). Odds of postoperative wound complications were significantly higher in those receiving AC (odds ratio, 1.33; 95% CI, 1.11‐1.61; P = .002). Conclusions: This study does not demonstrate a significant impact of therapeutic AC on primary patency for infrainguinal bypass grafts. Treatment with AC may benefit secondary patency in those with a prosthetic bypass, especially to an infrapopliteal target, but at an increased risk of postoperative wound complications.

Comparable perioperative mortality outcomes in younger patients undergoing elective open and endovascular abdominal aortic aneurysm repair

Background: Evidence for benefit of endovascular aneurysm repair (EVAR) over open surgical repair for de novo infrarenal abdominal aortic aneurysms (AAAs) in younger patients remains conflicting because of heterogeneous study populations and small sample sizes. The objective of this study was to compare perioperative and short‐term outcomes for EVAR and open surgery in younger patients using a large national disease and procedure‐specific data set. Methods: We identified patients 65 years of age or younger undergoing first‐time elective EVAR or open AAA repair from the Vascular Quality Initiative (2003‐2014). We excluded patients with pararenal or thoracoabdominal aneurysms, those medically unfit for open repair, and those undergoing EVAR for isolated iliac aneurysms. Clinical and procedural characteristics were balanced using inverse propensity of treatment weighting. A supplemental analysis extended the study to those younger than 70 years. Results: We identified 2641 patients, 73% (n = 1928) EVAR and 27% (n = 713) open repair. The median age was 62 years (interquartile range, 59‐64 years), and 13% were female. The median follow‐up time was 401 days (interquartile range, 357‐459 days). Unadjusted perioperative survival was 99.6% overall (open repair, 99.1%; EVAR, 99.8%; P < .001), with 97.4% 1‐year survival overall (open repair, 97.3%; EVAR, 97.4%; P = .9). Unadjusted reintervention rates were five (open repair) and seven (EVAR) reinterventions per 100 person‐years (P = .8). After propensity weighting, the absolute incidence of perioperative mortality was <1% in both groups (open repair, 0.9%, EVAR, 0.2%; P < .001), and complication rates were low. Propensity‐weighted survival (hazard ratio, 0.88; 95% confidence interval, 0.56‐1.38; P = .6) and reintervention rates (open repair, 6; EVAR, 8; reinterventions per 100 person‐years; P = .8) did not differ between the two interventions. The analysis of those younger than 70 years showed similar results. Conclusions: In this study of younger patients undergoing repair of infrarenal AAA, 30‐day morbidity and mortality for both open surgery and EVAR are low, and the absolute mortality difference is small. The prior published perioperative mortality and 1‐year survival benefit of EVAR over open AAA repair is not observed in younger patients. Further studies of long‐term durability are needed to guide decision‐making for open repair vs EVAR in this population.

Endovascular Repair of an Iliac Ureteroarterial Fistula with Late Stent Thrombosis and Migration into the Bladder

BACKGROUND Ureteroarterial fistulas are rare. We describe a case of ureteral-arterial fistulas (UAF) repaired with an endovascular stent graft and examine late complications associated with the procedure. CASE REPORT A 37-year-old woman with a history of complicated locally invasive cervical cancer treated with chemoradiation presented initially with right leg rest pain and chronic intermittent gross hematuria. She was found to have an ureteroarterial fistula and underwent successful endovascular exclusion with a covered stent with resolution of her symptoms. She returned 1 year later with stent-graft thrombosis manifesting as lower extremity rest pain, requiring a femoral-femoral bypass. She then returned 6 months later with imaging evidence of extravascular migration of the stent graft into the bladder. Because of a poor prognosis of recurrent gynecologic cancer, extraction was not attempted, and she underwent complete urinary diversion. CONCLUSIONS UAFs are a rare occurrence but may be treated successfully with endovascular stent grafting. Despite technical success, late complications such as stent thrombosis may occur even with anticoagulation. Extravascular stent migration may occur in the presence of a chronically dilated ureter.

Endovascular Treatment of Pulmonary Embolism

Acute pulmonary embolism can result in high rates of morbidity and mortality. Traditional treatments for pulmonary embolism such as systemic thrombolysis and surgical thrombectomy are associated with high complication rates. Advances in endovascular therapy have allowed for usage of minimally invasive approaches such as catheter-directed thrombolysis, aspiration thrombectomy, and pharmacomechanical thrombectomy in the treatment of acute pulmonary embolism. These therapies may provide similar hemodynamic improvement to traditional techniques while decreasing risks of serious complications. Acute pulmonary embolism is classified into low, intermediate, and high-risk presentations based on the presence or absence of hemodynamic instability, clinical risk factors, and biomarkers or imaging evidence of right ventricular dysfunction. Patients with high and intermediate-high risk presentations may benefit from intervention, but the risks of complications including intracranial hemorrhage must be taken into account when determining the type of intervention. Catheter-directed interventions have demonstrated good clinical success and excellent published safety profiles, but head-to-head comparisons of different interventional techniques have not been well studied. Further study of catheter-directed interventions and their effect on short- and long-term physiologic, functional, and quality-of-life outcomes is needed.

VESS22. Implementation of Drug-Eluting Stents for the Treatment of Femoropopliteal Disease Provides Significant Cost-to-System Savings: A Single-State Outpatient Simulation

(12% vs 4.2%; P 1⁄4 .48), modified frailty index (8.39 6 0.99 vs 5.35 6 1.24; P < .001), lower preoperative hematocrit (31.01 6 7.42 vs 33.25 6 8.10; P 1⁄4 .05), dependent preoperative functional status (29% vs 2.1%; P < .01), lack of family support (66.3% vs 17.9%; P < .01), were less likely to be married (83.2% vs 35.8%; P < .01), and were more likely to have an AKA (20.8% vs 52.6%; P 1⁄4 .004). Nonambulatory patients had a lower estimated life expectancy (Fig). There were no statistically significant differences in age, insurance status, race, smoking, or diabetes between ambulatory and nonambulatory patients. Factors influencing ambulatory status after multivariate logistic regression analysis included male sex (odds ratio [OR], 0.65; P 1⁄4 .01), preoperative dependent status (OR, 9.03; P < .001), current marriage (OR, 8.86; P 1⁄4 .01), and BMI (OR, 0.42; P < .01). Conclusions: Patients should be counseled that <50% of those undergoing MLEA are ambulatory postamputation and on the negative effect of obesity on ambulatory status. Efforts to reduce obesity may further improve ambulatory status in these patients.