Duplex Ultrasound Surveillance after Transcarotid Artery Revascularization (TCAR) in Clinical Practice.

BACKGROUND: To propose a protocol for the routine clinical use of duplex ultrasound (DUS) assessment after transcarotid artery revascularization (TCAR) procedures, with its specific point of vascular access, based on DUS data from routine clinical practice. METHODS: DUS data were retrospectively collected at 2 centers from a total of 97 patients who underwent a TCAR procedure with at least 30-day and up to 12-month follow-up. Peak systolic velocity (PSV), end diastolic velocity (EDV), and the internal carotid artery (ICA)/common carotid artery (CCA) PSV ratio were collected at baseline (≤30 days after the procedure) and compared with subsequent measurements. RESULTS: Baseline data were established within 30 days after the procedure. There were no access site stenoses, pseudoaneurysms, or dissections detected in follow-up. Average hemodynamics measurements at 12 months after the procedure (36% of patients reached this time point to date) were PSV 167 ± 153 cm/sec, EDV 51 ± 55 cm/sec, and ICA/CCA PSV 2.3 ± 1.9. Five patients (5.2%) exhibited velocities indicative of ≥80% in-stent restenosis (ISR) at 12 months after the procedure. Two patients (2.1%) underwent repeat intervention for ISR based on high velocities and before significant clinical consequence. The other 3 patients (3.1%) were asymptomatic and are being managed medically and monitored for neurological symptoms. One intraprocedural stroke (1.0% of total treated) was observed. CONCLUSIONS: This protocol not only illustrates the utility of using the CCA for the arterial access sheath for carotid stenting, but also successfully identifies patients with clinically significant restenosis >80%-99%. A surveillance regimen of baseline at ≤30 days after the procedure, followed by assessment at 6 and 12 months, and yearly thereafter appears to be a safe and effective protocol, based on the data available to date. A PSV >340 cm/sec and ICA/CCA ratio >4.15 is consistent with an 80-99% restenosis after TCAR. Although a small number, this study serves as a starting point for those who perform TCAR to specifically look at the CCA access site to rule out these potential pitfalls which did occur in the early trials.

Transcarotid repair of carotid artery pseudoaneurysm after carotid artery endarterectomy with tandem distal internal carotid artery stenosis.

Pseudoaneurysm development after carotid endarterectomy is a rare occurrence. Even rarer is pseudoaneurysm formation associated with a distal carotid artery stenosis. We report the case of stent grafting of a carotid artery pseudoaneurysm and tandem high-grade distal stenosis through a transcarotid approach with active flow reversal. No reported cases of a transcarotid artery approach to address a carotid artery aneurysm with tandem stenosis were found in the literature. We show that it may be a safe alternative to a transfemoral artery approach or open surgery.

Initial Experiences with Endovascular Management of Submassive Pulmonary Embolism: Is It Safe?

BACKGROUND: Interventional strategies for massive and submassive pulmonary embolism (smPE) have historically included either systematic intravenous thrombolytic alteplase or surgical embolectomy, both of which are associated with significant morbidity and mortality. However, with the advent of endovascular techniques, recent studies have suggested that an endovascular approach to the treatment of acute smPE may be both safe and effective with excellent outcomes. The purpose of this study was to evaluate the outcomes of patients who have undergone catheter-directed thrombolysis (CDT) for smPE at our institution in an effort to determine the safety of the procedure. METHODS: A retrospective review was conducted from December 2012 to June 2015 to identify patients whom underwent CDT in the treatment of a smPE at our institution. Primary measure was safety of the procedure. Outcome variables were classified as serious or minor adverse events. Serious events included death, stroke, myocardial infarction, and bleeding complications requiring surgical intervention or transfusion. Minor events included groin hematoma, development of arteriovenous fistula, and bleeding requiring interruption or cessation of CDT. In addition, a secondary measure included effectiveness of CDT based on preinterventional and postinterventional clinical examination and radiographic findings. RESULTS: A total of 27 patients undergoing CDT for smPE at our institution were evaluated. The standard procedure included access via bilateral femoral veins and placement of bilateral EKOS catheters for ultrasound-assisted thrombolysis (USAT), with Activase (alteplase) at 1 mg per hour in each catheter for a total of 12 hr. There were no serious adverse events and only 4 patients (14.8%) had minor events, of which only 1 patient required premature termination of therapy due to bleeding resulting in a 3.7% clinically relevant bleeding rate. In addition, a reduction in a right-to-left ventricular end-diastolic diameter ratio (RV/LV ratio) on follow-up imaging was observed in each of the 18 patients where preinterventional and postinterventional imaging was available. Likewise, via chart review, all patients reported significant cessation of shortness-of-breath and resolution of chest pain with associated decrease in supplemental oxygen requirement. CONCLUSIONS: Current evidence, the majority of which has been industry funded, suggests that CDT should be considered as the first-line therapy for smPE. Our experience, in this single-institution retrospective review, demonstrates that CDT with USAT in the treatment of smPE is safe, while providing immediate resolution of both RV strain and clinical symptoms such as shortness-of-breath and chest pain. We hope that these data will allow other institutions to consider CDT as a plausible option in the treatment of smPE.

Venous duplex and pathologic differences in thrombus characteristics between de novo deep vein thrombi and endovenous heat-induced thrombi.

OBJECTIVE: Superficial venous reflux disease has been treated with endovenous ablation techniques for more than 15 years. Thrombi discovered in the postoperative period are referred to as endovenous heat-induced thrombi (EHIT). In spite of the few studies of the ultrasound differentiation between EHIT and deep vein thrombi (DVT), there remains a paucity of literature regarding the evaluation of ultrasound examination and pathologic differentiation. METHODS: Six Yorkshire cross swine underwent femoral vein thrombosis by suture ligation or endovenous radiofrequency ablation. At 1 week after the procedure, each femoral vein was imaged by color Duplex ultrasound and sent for histologic interpretation for differentiation between EHIT and DVT. Five blinded vascular surgery faculty, two vascular surgery fellows, and three vascular surgery residents reviewed the ultrasound images. RESULTS: Thrombi associated with radiofrequency ablation demonstrated a greater degree of hypercellular response, fibroblastic reaction, and edema (3.42 vs 2.92; 3.75 vs 2.42; 2.83 vs 1.33). Specimens harvested from the iatrogenic-induced DVT swine demonstrated a more prolific response to trichrome staining (3.42 vs 2.67). Evidence of revascularization was found in all of the EHIT specimens but in 33% of DVT specimens. On the basis of histologic findings, the pathologist predicted correct modality 92% of the time. Subgroup analysis comparing paired specimens from each swine failed to demonstrate any marked pathologic differences. Recorded ultrasound images from EHIT and DVT samples were reviewed by fellows, residents, and vascular surgery staff to determine whether clot was stationary or free-floating (n = 111; 93%), evidence of retracted or adherent vein (n = 105; 88%), and absence of color flow (n = 102; 85%). The degree of occlusion (partial vs total) and degree of distention of a visualized vein were least likely to be agreed on by reviewers (n = 95; 79% each, respectively). In subgroup (DVT vs EHIT) analyses, the percentage agreement was greatest among vascular surgery fellows (89% and 92%) compared with residents (82% and 79%) and faculty (78% and 77%). CONCLUSIONS: It is possible to differentiate the thrombus origin on pathologic examination but not clinically on ultrasound. Wide variability exists for ultrasound diagnosis of EHIT and de novo DVT. Care must be taken in evaluating post-treatment duplex scans to not assign diagnosis of EHIT when DVT may well be present and extending into the deep venous system. The modulation of collagen production in the treatment of DVT may be helpful in preventing vascular dysfunction and reducing the post-thrombotic changes. Further studies on injury after radiofrequency ablation and laser ablation are needed.

Predictors and outcomes of gastrointestinal complications in patients undergoing coronary artery bypass graft surgery: a prospective, nested case-control study.

BACKGROUND: The aim of this study was to assess risk factors and outcomes of gastrointestinal (GI) complications in patients undergoing coronary artery bypass surgery (CABG). STUDY DESIGN: We conducted a nested case-control study from a 9-year hospitalization cohort (n = 7,345) in which data were collected prospectively. Patients developed GI complications (n = 66) and controls did not (n = 330). Cases were matched to controls 1:5 on type of surgery. We examined 16 risk factors and 14 outcomes. RESULTS: Five risk factors proved significant in predicting GI complications. Patients were more likely to be older than age 70, to be on dialysis, to have left ventricular hypertrophy, and to be on anticoagulants; the procedure was also more likely to be urgent. There was no significant difference between the cases and controls for the remaining 11 risk factors. We also computed correlation coefficients among the significant variables; using regression analysis, we found that patients undergoing CABG had a threefold increase in the risk of GI complications if they were older than age 70 (odds ratio [OR] 1.06, 95% CI 1.03 to 0.97), if they were on dialysis (OR 1.87, 95% CI 1.98 to 1.22), and if their procedure was urgent (OR 1.91, 95% CI 1.07 to 3.4). Eleven outcomes proved significant. Patients with GI complications ran a greater risk of mortality; required more additional procedures; suffered arrhythmia that required treatment; and were more likely to have neurologic, pulmonary, renal, and sternal wound complications. They also had greater length of hospitalization, intensive care unit length of hospitalization, ventilator time, and postoperative creatine phosphokinase levels. CONCLUSIONS: In patients undergoing CABG surgery, urgency of the procedure, age greater than 70 years, and dialysis all significantly increased the risk of a GI complication. Patients with GI complications also experienced more negative outcomes.

Radiofrequency ablation of the porcine liver with complete hepatic vascular occlusion.

BACKGROUND: We studied the effects of radiofrequency ablation, relative to hepatic blood flow, on the volume and shape of the resulting tissue necrosis. The extent of necrosis is directly proportional to the size of the electrode and inversely related to blood flow, which dissipates the heat generated. METHODS: Two areas of necrosis were created in each of eight porcine livers, which were assigned to four groups according to blood flow occlusion: no occlusion, occlusion of the hepatic artery and portal vein, occlusion of the hepatic veins, and complete hepatic vascular occlusion. After 25 minutes of liver reperfusion, the animals were euthanized, and the livers were examined. RESULTS: Complete vascular occlusion resulted in the greatest area of necrosis (28.6 +/- 3.4 cm(3)), followed by occlusion of the hepatic artery and portal vein (19.2 +/- 5.9 cm(3)), occlusion of hepatic veins (14.4 +/- 2.6 cm(3)), and no occlusion (4.9 +/- 1.5 cm(3)). The volume of the necrotic areas created during complete vascular occlusion were significantly greater than those created with no occlusion, as well as those created with only the hepatic artery and portal vein occluded (P <.05). CONCLUSIONS: Complete vascular occlusion, combined with radiofrequency ablation, increases the volume of necrosis and creates a more spherical ablative area.