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Macedo, Thanila A.

https://orcid.org/0000-0003-3556-1556

Mayo Clinic

Mayo Clinic

Citations 20

Novel Ultrasound Technique to Evaluate the Superior Segment of the Internal Jugular Vein in Normal Subjects
Macedo, Thanila A. , Claus, Luisa , Meixner, Duane D. , Hesley, Gina K. , Rooke, Thom W., Larson, Nicholas B. , Rooke, Thom W.

Ultrasound Quarterly | March 20, 2026 | Volume: 42 | Issue: 2 | Pages: No page available

10.1097/ruq.0000000000000724 Get It

A novel ultrasound technique was used to assess the superior segment of the internal jugular vein (IJV) in healthy individuals, evaluating the feasibility of visualizing this vein through the parotid gland and examining positional changes. Eighty-five patients undergoing unrelated carotid ultrasound were included, excluding those with headaches, migraines, or other neurological symptoms. A transducer was placed over the parotid gland, and gray scale images—with and without diameter measurement—and color and spectral Doppler of the IJV were obtained in neutral and head turned contralaterally. Technical feasibility and quantitative measurements with mean values and standard deviations were reported. Significant positional changes were assessed if paired data were available. Successful diameter measurements were obtained in at least one side in 79% to 80% of patients and bilaterally in 75%. Mean diameters were 5.5 cm (right) and 5 cm (left). Velocities were acquired in 82% (unilaterally) and 78% (bilaterally). Mean peak systolic velocities were 42 cm/s (right) and 32 cm/s (left). With head rotation, mean velocities were 46 cm/s (right) and 38 cm/s (left). In patients with paired measurements, velocities increased by over 50% in 19% to 28% of patients ( P <0.05 for both sides). There was no significant change in the diameter when the head was turned. Visualization of the superior IJV using a parotid window and evaluation of its diameter and internal velocities are feasible with the head in both neutral position and turned contralaterally.
Comparison of Bare Metal vs Covered Proximal Stent Fixation During Fenestrated Endovascular Aortic Repair of Complex Abdominal Aortic Aneurysms
Lima, Guilherme Baumgardt Barbosa , Huang, Ying , Kanamori, Lucas Ruiter , Saqib, Naveed, Macedo, Thanila A. , Mendes, Bernardo C. , Oderich, Gustavo S. , Lima, Guilherme B , Tenorio, Emanuel R , Oderich, Gustavo S , Tenorio, Emanuel R. , Schmid, Bruno , Maximus, Steven

Journal of Endovascular Therapy | November 10, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1177/15266028251388749 Get It

Purpose: Fenestrated stent-grafts with proximal bare-metal fixation stent (BMFS) may provide better rotational movement to facilitate vessel catheterization, but novel designs with covered fixation stents (CFSs) have been increasingly utilized with lower profile fabric. This study aimed to evaluate procedural metrics and outcomes of fenestrated endovascular repair (FEVAR) using BMFS and CFS devices. Methods: Clinical data of 502 consecutive patients enrolled in a prospective, non-randomized investigational device exemption (IDE) study were reviewed. Patients with 4-vessel fenestrated stent-grafts with BMFS or CFS for treatment of complex abdominal aortic aneurysms (CAAAs) and Extent IV thoracoabdominal aortic aneurysms (TAAAs) were included. Patients with Extent I-III TAAAs and stent-grafts designed with <4 fenestrations or scallops were excluded. Endpoints were technical success, radiation exposure, major adverse events (MAEs), patient survival, freedom from secondary interventions, and target artery instability (TAI). Results: There were 147 patients (29%; 85% male, median 75 years old) treated by FEVAR using 4-vessel fenestrated stent-grafts with BMFS in 79 patients or CFS in 68 patients. Patients treated with BMFS designs had significantly (p<0.05) higher prevalence of cigarette smoking and peripheral artery disease and less often had Extent IV TAAAs. Use of BMFS designs decreased from 88% (64/73) to 20% (15/74) after 2018 (p<0.001). Technical success was similar in patients treated with or without BMFS designs (99% vs 100%, p=0.47), but total operating time and cumulative air karma were significantly lower (p<0.05) in patients with CFS designs. Overall 30-day mortality was 1%, with no difference in mortality and MAEs among patients treated with or without BMFS (1% vs 1%, p=1.0 and 15% vs 12%, p=0.59), respectively. Patient survival at 1 and 3 years was 95%±2%, and 85%±4% for all patients with no difference between groups (p=0.51). Freedom from secondary interventions was 88%±3.6% for patients with BMFS and 86%±4.6% for those with CFS at 1 year (p=0.71), with also no difference at 3 years (p=0.55). Conclusion: FEVAR for CAAAs and Extent IV TAAAs was performed with high technical success, low mortality, and MAEs, independent of the use of BMFS. There is no difference in patient survival and freedom from secondary interventions in patients treated with or without BMFS. Clinical Impact One hundred forty-seven patients were treated with bare-metal fixation-stent (79) or covered fixation stents (68). Technical success was similar (p=.47). Overall 30-day mortality was 1%, with no difference in major adverse events (MAEs; p=.59). At 1- and 3-year, there was no difference in patient survival (p=.51), freedom from secondary intervention (p=.71). In conclusion, FEVAR for CAAAs and Extent IV TAAAs was performed with high technical success, low mortality and MAEs, independent of the use of bare-metal fixation stent.
Prospective Assessment of Changes in Target Vessel Peak Systolic Velocity Measurements After Fenestrated-Branched Endovascular Aortic Repair
Macedo, Thanila A. , Lima, Guilherme Baumgardt Barbosa , Hatz, Heather J., Hesley, Gina K. , Lekah, Alexander, Huang, Ying , Mendes, Bernardo C. , Sulzer, Titia A L , Tenorio, Emanuel R , Baumgardt Barbosa Lima, Guilherme, Hatz, Heather, Tallarita, Tiziano , Huang, Ying , Oderich, Gustavo S , Lima, Guilherme B , Mésnard, Thomas , Tenorio, Emanuel R. , Oderich, Gustavo S.

Journal of Endovascular Therapy | September 28, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1177/15266028251368250 Get It

Objective: Target vessel stenosis or occlusion is a common indication for secondary intervention after fenestrated-branched endovascular aortic repair requiring long-term imaging surveillance including duplex ultrasound (DUS). This study aimed to describe and compare longitudinal changes in peak systolic velocity (PSV) measurements for renal and mesenteric arteries targeted by directional branches (DBs) or reinforced fenestrations (RFs). Methods: Patients enrolled in a prospective, nonrandomized study (2013-2020) had DUS of celiac axis, superior mesenteric artery, and renal arteries (RAs) obtained preoperatively, at 6 to 8 weeks, 6 months, and annually. Vessels with preprocedural stenosis were excluded. Outcomes were variations in PSV over time for target vessels incorporated by DBs or RFs, differences in balloon-expandable stent-grafts (BESGs) and self-expandable stent-grafts (SESGs), PSV measurements prior to secondary interventions related to vessel stenosis, and a predictive value of PSV for stenosis requiring secondary intervention. Results: A total of 419 patients (292 male, mean age 74 ± 8 years old) were enrolled, with 1,311 target vessels analyzed preoperatively, including 607 mesenteric and 704 RAs. Over a median follow-up of 23 months (interquartile range [IQR], 7-36), PSV measurements decreased in the first 6 to 8 weeks after DB incorporation, remained stable, followed by a nonsignificant increase at 5 years. PSV increased in the first 6 months using RFs with postoperative velocities significantly higher ( P < .05) for RFs compared to DBs. Branched mesenteric vessels stented with BESGs had higher velocities than SESGs ( P < .05). Of the 23 target vessels treated by secondary intervention for stenosis, 19 (83%) had velocities above the thresholds for native, nonstented vessels. Furthermore, in RAs (n = 20) PSV effectively predicted clinically relevant stenosis, AUC was 0.98, with a 231 cm/s threshold offering 84% sensitivity with 100% specificity. Conclusion: Longitudinal follow-up shows that velocity changes vary depending on the type of incorporation, vessel, and bridging stent. For DBs, PSV decreased initially, stabilized, and showed a nonsignificant increase at 5 years. In contrast, PSV increased with RFs and remained higher than DBs. Despite these variations, velocities remained below established thresholds for clinically significant stenosis in nonstented vessels. Criteria for in-stent stenosis may differ, and PSV alone should not be the sole indicator for reintervention. Clinical Impact This study provides new insight into duplex ultrasound (DUS) surveillance after fenestrated and branched endovascular aneurysm repair (FB-EVAR). Peak systolic velocity (PSV) trends differed between fenestrations and branches, and stent type influenced flow dynamics. Importantly, most vessels with secondary interventions had elevated PSVs, but many others exceeded native stenosis thresholds without clinical consequence. Despite these variations, velocities remained below established thresholds for clinically significant stenosis in non-stented vessels. Criteria for in-stent stenosis may differ, and PSV alone should not be the sole indicator for reintervention.The reported PSV measurements served as a benchmark for DUS surveillance following FB-EVAR.
Modified Ex Vivo Renal Reconstruction to Facilitate Fenestrated-Branched Endovascular Repair of a Thoracoabdominal Aortic Aneurysm
Stutz, Jack , Lima, Guilherme Baumgardt Barbosa , Huang, Ying , Mendes, Bernado C., Macedo, Thanila A. , Oderich, Gustavo S. , Lima, Guilherme B , Oderich, Gustavo S

Journal of Endovascular Therapy | August 19, 2024 | Volume: 33 | Issue: 1 | Pages: 514-519

10.1177/15266028241270690 Get It

Purpose: To report the use of modified ex vivo renal artery (RA) reconstruction in a patient with 2 small right RAs (RRAs) in anticipation of planned fenestrated-branched endovascular aortic repair (FB-EVAR) of thoracoabdominal aortic aneurysm (TAAA). Case Report: A staged hybrid repair was utilized in a patient with Extent II TAAA involving celiac axis (CA), superior mesenteric artery (SMA), single left RA (LRA), and 2 small (<3 mm) RRAs. The first-stage operation consisted of hepato-renal bypass using modified ex vivo renal reconstruction with single end-to-end anastomosis to both RAs using a saphenous vein graft. A second stage FB-EVAR was performed using patient-specific manufactured stent-graft with 3 fenestrations for the CA, SMA, and LRA 6 weeks later. The patient recovered with no complications. At 4 years, the patient had widely patent hepato-renal bypass and target vessels with normal renal function. Conclusion: The use of adjunctive hybrid procedures may optimize or facilitate FB-EVAR. In this patient, salvage of 2 small RAs was not ideally suited for branch stenting but was possible using modified ex vivo RA reconstruction with preservation of kidney parenchyma and function. Clinical Impact This case report illustrates a hybrid approach to overcome one of the most frequent limitations to total endovascular incorporation of renal arteries, eg small diameter, early bifurcation and multiple vessels. The modified ex vivo technique allows meticulous renal artery reconstruction without the deleterious effect of warm ischemia and without the cumbersome reconstruction of ureter and vein that is needed with traditional on table ex vivo auto transplantation. The technique is used in a minority of cases and adds the morbidity of open approach. Case selection is of paramount importance.
Technical Pitfalls for Fenestrated-Branched Endovascular Aortic Repair Following PETTICOAT
Baghbani‐Oskouei, Aidin , Tenorio, Emanuel R. , Dias‐Neto, Marina , Vacirca, Andrea , Mirza, Aleem K. , Saqib, Naveed, Mendes, Bernardo C. , Ocasio, Laura , Macedo, Thanila A. , Oderich, Gustavo S. , Baghbani, Aidin , Tenorio, Emanuel R , Oderich, Gustavo S , Dias-Neto, Marina

Journal of Endovascular Therapy | March 30, 2023 | Volume: 31 | Issue: 5 | Pages: 790-796

10.1177/15266028231163439 Get It

Purpose: The Provisional Extension to Induce Complete Attachment Technique (PETTICOAT) uses a bare-metal stent to scaffold the true lumen in patients with acute or subacute aortic dissections. While it is designed to facilitate remodeling, some patients with chronic post-dissection thoracoabdominal aortic aneurysms (TAAAs) require repair. This study describes the technical pitfalls of fenestrated-branched endovascular aortic repair (FB-EVAR) in patients who underwent prior PETTICOAT repair. Technique: We report 3 patients with extent II TAAAs who had prior bare-metal dissection stents treated by FB-EVAR. Two patients required maneuvers to reroute the aortic guidewire, which was initially placed in-between stent struts. This was recognized before the deployment of the fenestrated-branched device. A third patient had difficult advancement of the celiac bridging stent due to a conflict of the tip of the stent delivery system into one of the stent struts, requiring to redo catheterization and pre-stenting with a balloon-expandable stent. There were no mortalities and target-related events after a follow-up of 12 to 27 months. Conclusion: FB-EVAR following the PETTICOAT is infrequent, but technical difficulties should be recognized to prevent complications from the inadvertent deployment of the fenestrated-branched stent-graft component in-between stent struts. Clinical Impact The present study highlights a few maneuvers to prevent or overcome possible complications during endovascular repair of chronic post-dissection thoracoabdominal aortic aneurysm following PETTICOAT. The main problem to be recognized is the placement of the aortic wire beyond one of the struts of the existing bare-metal stent. Moreover, encroachment of catheters or the bridging stent delivery system into the stent struts may potentially cause difficulties.
Characterization of Secondary Interventions After Fenestrated-branched Endovascular Repair of Complex Aortic Aneurysms and Its Effect on Quality of Life and Patient Survival
Tenorio, Emanuel R. , Mirza, Aleem K. , Lima, Guilherme Baumgardt Barbosa , Wong, Joshua , Mendes, Bernardo C. , Saqib, Naveed, Khan, Sophia, Macedo, Thanila A. , Tenorio, Emanuel R , Lima, Guilherme B , Marcondes, Giulianna B. , Wong, Joshua, Oderich, Gustavo S.

Annals of Surgery | July 8, 2022 | Volume: 278 | Issue: 1 | Pages: 140-147

10.1097/sla.0000000000005454 Get It

Objective: To assess the impact of secondary intervention (SI) on health-related quality of life (HR-QOL) after fenestrated-branched endovascular aortic repair (FB-EVAR) for complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysms. Background: The effect of SI after FB-EVAR on physical and mental HR-QOL has not been described. Methods: A cohort of 430 consecutive patients enrolled in a prospective, nonrandomized study to evaluate FB-EVAR (2013–2020) was assessed with 1325 short-form 36 HR-QOL questionnaires preoperatively and during follow-up visits. SIs were classified as major or minor procedures. Endpoints included patient survival, freedom from aortic-related mortality (ARM), freedom from SIs, and changes in HR-QOL physical component score (PCS) and mental component score. Results: There were 302 male with mean age 74±8 years treated by FB-EVAR for 133 complex abdominal aortic aneurysms and 297 thoracoabdominal aortic aneurysms. After a mean follow up of 26±20 months, 97 patients (23%) required 137 SIs. At 5 years, freedom from any SI was 64%±4%, including freedom from minor SIs of 77%±4% and major SIs of 87%±3%. There was no difference in patient survival and freedom from ARM at same interval. On adjusted analysis, minor SIs correlated with improved survival. SIs had a negative correlation with PCS (r=−0.8). There were no significant changes in mental component score with SIs. Predictors for SIs were fluoroscopy time, graft design, and aneurysm sac change. Conclusion: SIs were needed in nearly 1 out of 4 patients treated by FB-EVAR with no effect on patient survival or ARM. SI resulted in decline in PCS.
Midterm Outcomes of a Prospective, Nonrandomized Study to Evaluate Endovascular Repair of Complex Aortic Aneurysms Using Fenestrated-Branched Endografts
Oderich, Gustavo S. , Tenorio, Emanuel R. , Mendes, Bernardo C. , Lima, Guilherme Baumgardt Barbosa , Saqib, Naveed, Hofer, Jan , Wong, Joshua , Macedo, Thanila A. , Tenorio, Emanuel R , Lima, Guilherme B , Oderich, Gustavo S. , Marcondes, Giulianna B. , Wong, Joshua

Annals of Surgery | June 16, 2021 | Volume: 274 | Issue: 3 | Pages: 491-499

10.1097/sla.0000000000004982 Get It

Objective: The aim of this study was to investigate the midterm outcomes of fenestrated and branched endovascular aortic repair (FB-EVAR) of pararenal (PRA) and thoracoabdominal aortic aneurysms (TAAAs). Summary Background Data: FB-EVAR has been associated with decreased morbidity compared to open repair, but there is limited midterm data. Methods: A total of 430 patients (302 males, mean age 74 ± 8 years) treated by FB-EVAR were enrolled in a prospective, nonrandomized investigational device exemption study. Endpoints included 30-day mortality and major adverse events (MAEs), freedom from all cause and aortic-related mortality, target vessel patency, and freedom from secondary intervention and target vessel instability. Results: There were 133 PRAs and 297 TAAAs with 1673 renal-mesenteric arteries incorporated by fenestrations or directional branches (3.9 ± 0.5 vessels/patient). At 30 days or within the hospital stay if longer than 30 days, there were 4 (0.9%) deaths. MAEs included new-onset dialysis in 8 patients (2%), permanent paraplegia or stroke in 10 patients each (2%), and respiratory failure requiring tracheostomy in 2 patients (0.5%). After a mean follow-up of 26 ± 20 months, there were 3 (0.7%) aortic-related deaths from SMA stent occlusion, gastrointestinal hemorrhage, or complications of open arch repair. At 5 years, freedom from all-cause and aortic-related mortality were 57% ± 5% and 98% ± 1%, respectively. Freedom from secondary intervention was 64% ± 4%, primary target vessel patency was 94% ± 1%, and freedom from target vessel instability was 89% ± 2% at same interval. One patient (0.2%) had nonfatal aneurysm treated using endovascular repair. Conclusion: FB-EVAR is safe and effective for treatment of PRA and TAAAs with low rate of aortic-related mortality and aneurysm rupture on midterm follow-up.
Incorporation of Celiomesenteric Trunk With Double Kissing Directional Branches During Fenestrated-Branched Endovascular Aortic Repair
Marcondes, Giulianna B. , Tenorio, Emanuel R. , Lima, Guilherme Baumgardt Barbosa , Mendes, Bernardo C. , Saqib, Naveed, Khan, Sophia, Macedo, Thanila A. , Lee, Hansoo , Lima, Guilherme B , Mendes, Bernardo, Tenorio, Emanuel R , Oderich, Gustavo S.

Journal of Endovascular Therapy | May 17, 2021 | Volume: 28 | Issue: 4 | Pages: 636-641

10.1177/15266028211016430 Get It

Purpose: Common celiomesenteric trunk (CMT) is a rare anatomical variation that occurs in 0.5% to 3.4% of the general population. Its presence may complicate planning and implantation of fenestrated and branched stent-grafts because the wide diameter and short length of the CMT to its bifurcation does not allow sufficient sealing for placement of bridging stents. Case Report: We report a patient with thoracoabdominal aortic aneurysm (TAAA) and CMT treated by fenestrated-branched endovascular aortic repair (FB-EVAR) using double kissing directional branches to incorporate the celiac axis and superior mesenteric artery. Pitfalls of stent design and implantation are outlined. Conclusion: Double kissing directional branches should be considered as an alternative to incorporate vessels with early bifurcation such as a CMT.
1α,25-Dihydroxyvitamin D3 Encapsulated in Nanoparticles Prevents Venous Neointimal Hyperplasia and Stenosis in Porcine Arteriovenous Fistulas
Singh, Avishek , Cai, Chuanqi , Kilari, Sreenivasulu , Zhao, Chenglei , Simeon, Michael L. , Takahashi, Edwin A. , Kong, Hyunjoon , Macedo, Thanila A. , Misra, Sanjay , Singh, Avishek K, Takahashi, Edwin, Macedo, Thanila, Misra, Sanjay , Kong, Hyunjoon , Takahashi, Edwin A , Edelman, Elazer R. , Singh, Ravinder J. , Urban, Matthew W. , Kumar, Rajiv , Kilari, Sreenivasulu

Journal of the American Society of Nephrology | February 24, 2021 | Volume: 32 | Issue: 4 | Pages: 866-885

10.1681/asn.2020060832 Get It

Significance Statement Expression of immediate early response gene X-1 ( Iex-1 ), also known as Ier-3, is increased in venous neointimal hyperplasia (VNH) and stenosis in hemodialysis arteriovenous fistulas (AVF). In a porcine model, 1α,25(OH) 2 D 3 , an inhibitor of Ier3, reduced VNH/stenosis formation. The 1α,25(OH) 2 D 3 released in the perivascular AVF space from poly(lactic-co-glycolic acid) nanoparticles embedded in a Pluronic F127 hydrogel (1,25 NP) reduced Ier3 gene and protein expression, MCP-1, CD68, HIF-1α, and VEGF-A immunostaining. Concomitantly, blood flow, lumen area, pulse wave velocity, and Young’s modulus increased, and neointima area, peak systolic velocity, and wall shear stress decreased in 1,25 NP–treated vessels. RNA sequencing analysis identified 242 genes involved in inflammatory and apoptotic pathways that had decreased expression in 1,25 NP vessels. Background Few therapies prevent venous neointimal hyperplasia (VNH) and venous stenosis (VS) formation in arteriovenous fistulas (AVF). Expression of the immediate early response gene X-1 ( Iex-1 ), also known as Ier3, is associated with VNH and stenosis in murine AVFs. The study aimed to determine if local release of Ier3 long-acting inhibitor 1α,25(OH) 2 D 3 from poly(lactic-co-glycolic acid) (PLGA) nanoparticles embedded in a thermosensitive Pluronic F127 hydrogel (1,25 NP) could affect VNH/VS formation in a large animal model. Methods Immediately after AVF creation in a porcine model of renal failure, 1,25 NP or vehicle control was injected into the adventitia space of AVF outflow veins. Scanning electron microscopy and dynamic light scattering characterized drug and control nanoparticles. Animals were sacrificed 3 and 28 days later for gene expression, immunohistologic, magnetic resonance imaging and angiography, and ultrasound analyses. Whole transcriptome RNA sequencing with differential gene expression analysis was performed on outflow veins of AVF. Results Encapsulation of 1α,25(OH) 2 D 3 in PLGA nanoparticles formed nanoparticles of uniform size that were similar to nanoparticles without 1α,25(OH) 2 D 3 . The 1,25 NP–treated AVFs exhibited lower VNH/VS, Ier3 gene expression, and IER-3, MCP-1, CD68, HIF-1α, and VEGF-A immunostaining, fibrosis, and proliferation. Blood flow and lumen area increased significantly, whereas peak systolic velocity and wall shear stress decreased. Treatment increased Young’s modulus and correlated with histologic assessment of fibrosis and with no evidence of vascular calcification. RNA sequencing analysis showed changes in the expression of genes associated with inflammatory, TGFβ1, and apoptotic pathways. Conclusions Local release of 1,25 NP improves AVF flow and hemodynamics, and reduces stenosis in association with reduction in inflammation, apoptosis, and fibrosis in a porcine model of arteriovenous fistula.
Acute Deep Vein Thrombosis and Association with Popliteal Fossa (Baker's) Cysts in Patients with Lower Extremity Duplex Ultrasound Examination
Vlazny, Danielle T. , Meverden, Ryan A., Daniels, Paul R. , Bartlett, Matthew , Hesley, Gina K. , Macedo, Thanila A. , Lekah, Alexander, Houghton, Damon E. , Wysokiński, Waldemar E.

Blood | November 4, 2020 | Volume: 136 | Issue: Supplement 1 | Pages: 9-10

10.1182/blood-2020-134231 Get It

Background: Popliteal fossa cysts (PFCs aka Baker's cysts) are synovial cysts of the knee joint that can be symptomatic or asymptomatic and incidentally identified on ultrasound. Whether PFCs are associated with deep vein thrombosis (DVT) is unknown. Possible mechanisms for an association include direct compression of the popliteal vein, indirect compression on the popliteal vein with leg flexion, adjacent inflammation of the cyst, or relative immobility due to underlying joint disease itself. Methods: Lower extremity venous Duplex ultrasound radiology reports from the inception of electronic archiving through 11/14/2019 were evaluated across the Mayo Clinic Enterprise (Rochester MN, Jacksonville, FL, Scottsdale AZ, and Mayo Clinic Health System) in patients &gt;18 years of age. Natural language processing (NLP) algorithms were created and validated to identify acute DVT (proximal or distal) and PFCs. A random sample of 1,752 ultrasound reports underwent manual review to calculate the sensitivity and specificity of the NLP algorithm. Cases (ultrasounds with acute DVT) were compared to controls (ultrasound without acute DVT) to examine the frequency of PFCs. IRB approval was obtained and patients lacking Minnesota research authorization were excluded. Results: A total of 332,016 lower extremity venous ultrasounds were performed in 223,035 patients; 156,846 unilateral and 175,170 bilateral lower extremities exams. The mean age at ultrasound was 63.3 (SD 16.5) and 54.7% were female. Ultrasound reports were available for analysis starting in 1992 with a significant increase in the number of ultrasounds performed over the study period across the enterprise (Figure 1). Overall, acute DVT was identified in 24,179 (7.3%) of ultrasounds, and PFCs were identified in 32,427 (9.8%) of ultrasounds. The sensitivity and specificity of the NLP algorithm in the full dataset to identify acute DVT was 86.0% and 97.2%, respectfully. The sensitivity and specificity of the NLP algorithm to identify PFCs was 97.8% and 99.5%, respectively. PFCs were present in 9.3% of ultrasounds with acute DVT and 9.8% of ultrasounds without acute DVT (p=0.007), OR 0.94 (95% CI 0.90-0.98). In a multivariate logistic regression model, after adjusting for age and sex, results remained significant (aOR 0.95, 95% CI 0.91-0.995). Comparing ultrasounds before and after 2010, there was a higher percentage of PFCs and acute DVT reported after 2010 (p&lt;0.001 for both). Sensitivity analyses comparing results before or after 2010, by sex, and only in the first ultrasound performed per person, demonstrated similar results. Conclusions: PFCs are negatively associated with the presence of acute DVT on lower extremity venous Duplex ultrasound. This data does not support PFCs as a contributing or causative factor in the development of lower extremity DVT. Figure 1 Disclosures No relevant conflicts of interest to declare.