Percent Thrombus Predicts Popliteal Artery Aneurysm Related Limb Threatening Events.

OBJECTIVE: The objective of this study was to identify clinical and anatomic characteristics of Popliteal artery aneurysms (PAAs) associated with acutely limb threatening events. SUMMARY BACKGROUND DATA: Popliteal artery aneurysms (PAAs) are associated with high morbidity and mortality. Current guidelines recommend operative repair for PAAs with a diameter greater than 20 mm based on very limited evidence. METHODS: This retrospective cross-sectional cohort was derived from a multi-institutional database queried for all patients with a PAA from 2008 to 2022. Duplex ultrasound (DUS) characteristics of PAAs were abstracted by registered physicians in vascular interpretation. Symptom status at the time of DUS was divided into three categories: asymptomatic PAA, symptomatic PAA with claudication or chronic limb ischemia, and acutely limb threatening PAAs with a thromboembolic event, acute limb ischemia, or rupture. RESULTS: There were 470 PAAs identified in 331 patients. The mean age was 74 years at diagnosis, 94% of patients were white, and 97% of patients were male. In a univariate analysis, patient comorbidities and medications were not associated with symptom status. In a multivariate analysis including age, higher percent thrombus was significantly associated with symptomatic PAAs (RRR 15.2; CI 2.69-72.3; P<0.01) and PAAs with an acutely limb threatening event (RRR 17.9; CI 3.76-85.0; P<0.01). All other anatomic characteristics were not associated with symptom status. CONCLUSION: Percent thrombus was significantly associated with symptomatic PAAs and acutely limb threatening events, whereas diameter was not significantly associated with any symptom group. This analysis supports the use of percent thrombus in identifying high risk PAAs that warrant repair.

Popliteal artery aneurysm ultrasound criteria for reporting characteristics.

INTRODUCTION: Duplex ultrasound (DUS) is the modality of choice for surveillance of popliteal artery aneurysms (PAAs). However, noninvasive vascular laboratories have no standard guidelines for reporting results. This study assessed reports of PAA DUS for inclusion of information pertinent to operative decision-making and timing of surveillance. METHODS: This study was a retrospective review of a multi-institutional repository that was queried for all patients with a PAA from 2008 to 2022 and confirmed via manual chart review. DUS reports were abstracted and images were individually annotated for features of interest including dimensions, flow abnormalities, and percent thrombus burden. RESULTS: A total of 166 PAAs in 130 patients had at least one DUS available for viewing. Postoperative surveillance of PAAs was performed at several intervals: the first at 30 months (IQR 3.7-113, n = 44), the second at 64 months (IQR 20-172, n = 31), and the third at 152 months (IQR 46-217, n = 16) after the operation. The largest diameter of operative PAAs (median 27.5 mm, IQR 21.8-38.0) was significantly greater than nonoperative PAAs (median 20.9 mm, IQR 16.7-27.3); p < 0.01. Fewer than 33 (21%) reports commented on patency of distal runoff. We calculated an average percent thrombus of 60% (IQR 19-81) in nonoperative PAAs, which is significantly smaller than 75% (IQR 58-89) in operative PAAs; p < 0.01. CONCLUSION: In this multi-institutional retrospective study, PAAs are often not followed at intervals recommended by the Society for Vascular Surgery guidelines and do not include all measurements necessary for clinical decision-making in the multi-institutional repository studied. There should be standardization of PAA DUS protocols performed by all noninvasive vascular laboratories to ensure completeness of PAA DUS images and inclusion of characteristics pertinent to clinical decision-making in radiology reports.

Utilization of Thromboelastography with Platelet Mapping to Predict Infection and Poor Wound Healing in Postoperative Vascular Patients.

BACKGROUND: Postoperative infection and wound dehiscence rates are higher than expected in peripheral artery disease and contribute significantly to limb loss and mortality. Microvascular pathology characterized by microthrombi and increased platelet aggregation have been cited as contributing factors to poor wound healing and infection. The emergence of viscoelastic assays, such as thromboelastography with platelet mapping (TEG-PM), have been utilized to identify prothrombotic states and may provide insight into a patient's microvascular coagulation profile. This prospective, observational study aimed to determine if TEG-PM could predict poor wound healing or infection following lower extremity revascularization. METHODS: All patients undergoing revascularization between December 2020 and January 2022 were prospectively included and followed for wound complications or non-surgical site infections of the index limb. TEG-PM metrics at the first postoperative follow-up in the nonevent group was compared to the TEG-PM sample preceding the diagnosis of infection/dehiscence in the event group. Cox proportional hazards (PH) regression was used to model the predictive value of viscoelastic parameters. Cut-point analysis to determine high-risk groups was determined by performing receiver operating characteristic curve analysis. RESULTS: Of the 102 patients, 18.6% experienced infection/dehiscence. The TEG-PM sample analyzed in the event group was, on average, 19.5 days prior to the diagnosis of an event. The event group had significantly higher maximum clot amplitude (MA) (47.3 mm ± 16.0 vs. 30.6 mm ± 15.3, P < 0.01), higher platelet aggregation (71.3% ± 27.7 vs. 31.2% ± 24.0, P < 0.01), and lower platelet inhibition (28.7% ± 27.7 vs. 68.7% ± 24.1, P < 0.01). Cox PH analysis identified platelet aggregation as an independent and consistent predictor of infection (hazard ratio = 1.04, 95% confidence interval 1.03-1.06, P < 0.01). An optimal cut-point of > 33.2 mm MA, > 46.6% platelet aggregation, or < 55.8% platelet inhibition identifies those with infection/dehiscence with 79.0-89.5% sensitivity. CONCLUSIONS: These are the first data to provide a quantitative link between prothrombotic viscoelastic coagulation profiles with the development of infection/dehiscence. Based on the cut-points of > 33.2 mm MA, > 46.6% platelet aggregation, or < 55.8% platelet inhibition, we recommend consideration of an enhanced antimicrobial or antithrombotic approach for these high risk groups.