Changes in renal-mesenteric duplex ultrasound velocities after fenestrated and branched endovascular aortic aneurysm repair.

OBJECTIVE: Stenting of renal and mesenteric vessels may result in changes in velocity measurements due to arterial compliance, potentially giving rise to confusion about the presence of stenosis during follow-up. The aim of our study was to compare preoperative and postoperative changes in peak systolic velocity (PSV, cm/s) after placement of the celiac axis (CA), superior mesenteric artery (SMA) and renal artery (RAs) bridging stent grafts during fenestrated-branched endovascular aortic repair (FB-EVAR) for treatment of complex abdominal aortic aneurysms (AAA) and thoracoabdominal aortic aneurysms. METHODS: Patients were enrolled in a prospective, nonrandomized single-center study to evaluate FB-EVAR for treatment of complex AAA and thoracoabdominal aortic aneurysms between 2013 and 2020. Duplex ultrasound examination of renal-mesenteric vessels were obtained prospectively preoperatively and at 6 to 8 weeks after the procedure. Duplex ultrasound examination was performed by a single vascular laboratory team using a predefined protocol including PSV measurements obtained with <60° angles. All renal-mesenteric vessels incorporated by bridging stent grafts using fenestrations or directional branches were analyzed. Target vessels with significant stenosis in the preoperative exam were excluded from the analysis. The end point was variations in PSV poststent placement at the origin, proximal, and mid segments of the target vessels for fenestrations and branches. RESULTS: There were 419 patients (292 male; mean age, 74 ± 8 years) treated by FB-EVAR with 1411 renal-mesenteric targeted vessels, including 260 CAs, 409 SMAs, and 742 RAs. No significant variances in the mean PSVs of all segments of the CA, SMA, and RAs at 6 to 8 weeks after surgery were found as compared with the preoperative values (CA, 135 cm/s vs 141 cm/s [P = .06]; SMA, 128 cm/s vs 125 cm/s [P = .62]; RAs, 90 cm/s vs 83 cm/s [P = .65]). Compared with baseline preoperative values, the PSV of the targeted vessels showed no significant differences in the origin and proximal segment of all vessels. However, the PSV increased significantly in the mid segment of all target vessels after stent placement. CONCLUSIONS: Stent placement in nonstenotic renal and mesenteric vessels during FB-EVAR is not associated with a significant increase in PSVs at the origin and proximal segments of the target vessels. Although there is a modest but significant increase in velocity measurements in the mid segment of the stented vessel, this difference is not clinically significant. Furthermore, PSVs in stented renal and mesenteric arteries were well below the threshold for significant stenosis in native vessels. These values provide a baseline or benchmark for expected PSVs after renal-mesenteric stenting during FB-EVAR.

Popliteal cysts are not a risk factor for lower extremity deep vein thrombosis.

BACKGROUND: Popliteal cysts (PC) result from distension of the gastrocnemio-semimembranosous bursa. Published reports indicate coincident PC and deep vein thrombosis (DVT). Whether the presence of PC increase the risk of deep vein thrombosis (DVT) remains unclear. METHODS: Lower extremity venous Duplex ultrasound (DUS) reports were evaluated across the Mayo Clinic Enterprise (Rochester, Minnesota, Jacksonville, Florida, Scottsdale, Arizona, and the Mayo Clinic Health System) in patients ≥ 18 years of age. Natural language processing (NLP) algorithms were created and validated to identify acute lower extremity DVT and PC from these reports. To determine whether there is a link between PC and lower extremity DVT, the frequency of PC among cases (ultrasounds with acute DVT) were compared to controls (ultrasounds without acute DVT). RESULTS: A total of 357,703 lower extremities venous DUS were performed in 237,052 patients (mean age 63.3 ± 16.6, 54.4% were female) between 1992 and 2021. Acute DVT was identified in 32,572 (9.1%) DUS, and PC in 32,448 (9.1%). PC were seen in a lower frequency (8.0%) of ultrasounds with acute DVT than those without (9.2%) acute DVT (OR: 0.85, 95% CI: 0.82 to 0.89, p < 0.001). In a multivariate logistic regression model after adjusting for age, sex, and race, PCs were not positively associated with acute DVT (adjusted OR: 0.84, 95% CI: 0.81 to 0.88). CONCLUSIONS: PC are an incidental finding or an alternative diagnosis on lower extremity venous DUS, a finding that increases significantly with age. PC were not a risk factor in the development of lower extremity DVT.

Resolution of acute lower extremity deep vein thrombosis with rivaroxaban compared to warfarin.

Thrombosis resolution is an important component of treatment for deep vein thrombosis (DVT) and multiple anticoagulants are now available. It is unknown whether rivaroxaban contributes to a higher degree of thrombus resolution compared to conventional anticoagulation with warfarin. Our objective was to compare thrombus resolution for rivaroxaban versus warfarin treated patients with acute lower extremity DVT. Consecutive patients treated for proximal or distal lower extremity DVT with rivaroxaban were identified from the Mayo Thrombophilia Clinic Anticoagulants Registry (November 2015-June 2016) and compared to patients treated with warfarin. Ultrasonography/Doppler images were analyzed by two independent radiologists blinded to anticoagulant and using a standardized assessment algorithm. A total of 111 patients with DVT were studied. Sixty-three rivaroxaban treated patients were compared to 48 warfarin treated patients over a median follow up of 92 and 97 days, respectively. Percentage of patients with total or partial resolution of thrombosis was similar in rivaroxaban and warfarin treated groups (95.2% vs. 91.7%, p = 0.46, respectively); also the proportion of patients with total thrombus resolution was not significantly different (38.1% vs. 29.2%, p = 0.42, respectively). There was no significant difference in the proportion of patients with no thrombus resolution between rivaroxaban and warfarin treated groups either (4.8% vs. 2.1%, p = 0.63). Thrombus propagation with warfarin therapy was observed in 6.3% of patients treated with warfarin and in none of the patients from the rivaroxaban group (p = 0.08). Resolution of acute lower extremity DVT in patients treated with rivaroxaban is similar to those treated with warfarin.

Bleeding Rate for Ultrasound-Guided Paracentesis in Thrombocytopenic Patients.

OBJECTIVES: The purpose of this study was to determine the rate of major bleeding complications for ultrasound-guided paracentesis performed in thrombocytopenic patients. METHODS: We retrospectively reviewed the electronic medical records of patients with platelet counts of less than 50,000/µL who had ultrasound-guided paracenteses performed in the Department of Radiology without correcting preprocedural platelet transfusions between 2005 and 2011. Medical records were evaluated for evidence of major bleeding complications (grade 3 or higher as defined by the National Institutes of Health's Common Terminology Criteria for Adverse Events, version 4.03) and their clinical sequelae. Platelet count and bleeding complications were evaluated for an association, and a sensitivity analysis was performed to determine whether analysis of a control group of patients without thrombocytopenia would yield added confidence in this assessment. RESULTS: Among 304 procedures in 205 thrombocytopenic patients (69% male; mean age ± SD, 56.6 ± 11.9 years), the mean platelet count was 38,400 ± 9300/µL (range, 9000-49,000/µL). Three major bleeding complications requiring red blood cell transfusion were observed in patients with platelet counts of 41,000 to 46,000/µL, for a complication rate of 0.99% (95% confidence interval, 0.3%-2.9%). No patient required an additional procedure or died because of the bleeding complication. There was no association of platelet count with bleeding complications. The sensitivity analysis showed that further evaluation of patients with normal platelet counts would not add to the conclusion. CONCLUSIONS: The risk of major bleeding after ultrasound-guided paracentesis in thrombocytopenic patients is very low. In most patients, routine assessment of the preprocedural serum platelet concentration is not necessary, and correction of such an abnormal laboratory value is not indicated.

Critical care ultrasonography differentiates ARDS, pulmonary edema, and other causes in the early course of acute hypoxemic respiratory failure.

BACKGROUND: Pathogenic causes of acute hypoxemic respiratory failure (AHRF) can be difficult to identify at early clinical presentation. We evaluated the diagnostic utility of combined cardiac and thoracic critical care ultrasonography (CCUS). METHODS: Adult patients in the ICU were prospectively enrolled from January through September 2010 with a Pao2/Fio2 ratio < 300 on arterial blood gas (ABG) analysis within 6 h of a new hypoxemic event or the ICU admission. Focused cardiac and thoracic CCUS was conducted within 6 h of ABG testing. Causes of AHRF were categorized into cardiogenic pulmonary edema (CPE), ARDS, and miscellaneous causes after reviewing the hospitalization course in electronic medical records. RESULTS: One hundred thirty-four patients were enrolled (median Pao2/Fio2 ratio, 191; interquartile range, 122-253). Fifty-nine patients (44%) received a diagnosis of CPE; 42 (31%), ARDS; and 33 (25%), miscellaneous cause. Analysis of CCUS findings showed that a low B-line ratio (proportion of chest zones with positive B-lines relative to all zones examined) was predictive of miscellaneous cause vs CPE or ARDS (receiver operating characteristic area under the curve [AUC], 0.82; 95% CI, 0.75-0.88). For further differentiation of CPE from ARDS, left-sided pleural effusion (> 20 mm), moderately or severely decreased left ventricular function, and a large inferior vena cava minimal diameter (> 23 mm) were predictive of CPE (AUC, 0.79; 95% CI, 0.70-0.87). CONCLUSIONS: Combined cardiac and thoracic CCUS assists in early bedside differential diagnosis of ARDS, CPE, and other causes of AHRF.

Safety of ultrasound-guided thoracentesis in patients with abnormal preprocedural coagulation parameters.

BACKGROUND: Despite a low incidence of hemorrhagic complications following thoracentesis, correction or attempted correction of abnormal preprocedural coagulation parameters is still commonly performed. We aimed to assess hemorrhagic complications following ultrasound-guided thoracentesis in patients with abnormal preprocedural coagulation parameters. METHODS: We analyzed 1,009 ultrasound-guided thoracenteses performed between January 2005 and September 2011 on patients with international normalized ratio (INR) > 1.6, serum platelet values < 50 × 109/L, or both. Procedures were divided into two groups: those in whom abnormal preprocedural coagulation parameters were not corrected before the thoracentesis (group 1) and a second group in which patients received a transfusion of platelets or fresh frozen plasma prior to thoracentesis (group 2). All procedures were evaluated for hemorrhagic complications as defined by the National Institutes of Health Common Terminology Criteria for Adverse Events. RESULTS: A total of 1,009 ultrasound-guided thoracenteses were included in our study, consisting of 706 procedures in 538 patients in group 1 and 303 procedures in 235 patients in group 2. There were four hemorrhagic complications out of 1,009 procedures (0.40%; 95% CI, 0.15%-1.02%): zero in group 1 (0 of 706 or 0.0%; 95% CI, 0%-0.68%) and four in group 2 (four of 303 or 1.32%; 95% CI, 0.51%-3.36%). CONCLUSIONS: Hemorrhagic complications are infrequent after ultrasound-guided thoracentesis, and attempting to correct an abnormal INR or platelet level before the procedure is unlikely to confer any benefit. We consider the procedure safe in patients with abnormal preprocedural parameters when performed by expert personnel.