Tony Lu

Single-center retrospective review of ultrasound-accelerated versus traditional catheter-directed thrombolysis for acute lower extremity deep venous thrombosis:

Objective Systemic anticoagulation remains the standard for acute lower extremity (LE) deep venous thrombosis (DVT), but growing interest in catheter-directed thrombolysis (CDT) and its potential to reduce the incidence of post-thrombotic syndrome (PTS) has led to advent of ultrasound-accelerated CDT (US-CDT). Few studies to date have examined the outcomes of US-CDT against traditional CDT (T-CDT). Methods This is a retrospective, single-center review of all patients treated for acute LE DVT over a five-year period with either US- and T-CDT. Patients were stratified based on demographics, presentation, co-morbidities, risk factors, and peri-procedural data. Results Seventy-six limbs in 67 patients were treated; 51 limbs in 42 patients were treated with US-CDT, and 25 limbs in 25 patients were treated with T-CDT. Adjuncts include: pharmacomechanical thrombolysis (n = 28 vs. 20, p = 0.04), angioplasty (n = 22 vs. 18, p = 0.11), stenting (n = 30 vs. 6, p ≤ 0.001), and IVC filter insertion (n = 5 vs. 0, p = 0.07). Mean lysis times were 21 ± 1.7 and 24 ± 1.8 h for US- and T-CDT, respectively (p = 0.26). Thirty (25 ultrasound, 5 traditional) limbs had complete lysis. Thirty-one (22 ultrasound, 9 traditional) limbs had incomplete lysis. Fifteen (4 ultrasound, 11 traditional) limbs had ineffective lysis (p = 0.002 in favor of ultrasound). Four patients (3 US-CDT, 1 T-CDT) had recurrent ipsilateral thrombosis within 30 days (p = 0.60). By Kaplan-Meier analysis, there were no significant difference between primary patency, primary-assisted patency, secondary patency, re-thrombosis, and recurrent symptoms at 6, 12, and 24 months. Conclusion US-CDT does not significantly improve mid-term patencies but results in greater acute clot burden reduction in patients with acute LE DVTs compared to T-CDT, which may be beneficial in reducing the long-term incidence of PTS.

Robotic-Assisted Inferior Vena Cava Filter Retrieval

Although anticoagulation remains the mainstay of therapy for patients with venous thromboembolism, guidelines recommend the use of inferior vena cava (IVC) filters in those who fail anticoagulation or have contraindications to its use. Short-term use of filters has proven effective in reducing the rate of pulmonary embolism. However, their extended use is associated with a variety of complications such as thrombosis, filter migration, or caval perforation, thus making a case for timely filter retrieval. This is the case of a 68-year-old female with a history of chronic oral anticoagulation use for multiple deep venous thrombi (DVT) and pulmonary emboli (PE) who required cervical and thoracic spinal intervention for spondylosis and foramina stenosis. Given her increased risk of recurrent DVT and PE perioperatively, we elected to place a Cook Celect™ IVC filter (Cook Medical, Bloomington, IN) after oral anticoagulation was stopped for the procedure. Her treatment course was prolonged due to wound-healing complications. We elected to use the Magellan Robotic Catheter System (Hansen Medical, Mountain View, CA) for filter retrieval when she presented 6 months later with caval perforation from the filter struts. With its ease of use, superior mechanical stability, and maneuverability, robot-assisted IVC filter retrieval may be a safer and more reliable substitute for traditional navigation techniques when presented with challenging filter retrievals.

DynaCT angiography for the diagnosis of bilateral bow hunter's syndrome

We herein present a rare case of bilateral positional vertebrobasilar insufficiency secondary to mechanical obstruction of the V2 segment of the vertebral artery in a 71-year-old patient presenting with vertigo, occipital headache, tremors and respiratory irregularities. Two-dimensional digital subtraction angiography is the traditional diagnostic imaging standard but does not capture any peri-vascular bony or soft tissue abnormalities that are important to understand the three-dimensional pathophysiology. Intra-procedural cone-beam computed tomography (CT) is an increasingly used diagnostic adjunct, available in most modern angiographic suites that allows for the three-dimensional visualization of the vasculature as well as CT-like soft tissue visualization of its surrounding anatomy. In this case, we report the additional value of three-dimensional reconstructed cone-beam CT angiographic imaging that led to the successful diagnosis of bilateral positional vertebrobasilar disease. The patient subsequently received C4–C6 cervical decompression and fusion and remains symptom free at 1 year follow-up.

Right Brachial to Atrial Xenograft Conduit for Hemodialysis Access: A Case Report

Biologic grafts may be a viable alternative to their prosthetic counterparts in the patients who have exhausted conventional access alternatives given their superior patency rates and possible resilience to infection. This is a case report of a 66-year-old woman with end-stage renal disease and human immunodeficiency virus who has had multiple failed peripheral arteriovenous (AV) fistulas and grafts as well as inferior vena caval obstruction necessitating a transhepatic catheter for hemodialysis (HD). Given the patients comorbidities and history, a right brachial artery-to-atrial conduit was created for long-term access. Biologic bovine carotid artery was used given its decreased susceptibility to infection and favorable patency rates. The AV access continues to function at 3.5-year follow-up and remains her primary means of HD. We present this novel use of a biologic graft as an option in patients with central venous obstruction and high risk of infection requiring exotic dialysis access.

Short- and midterm results for internal jugular vein extension for short right renal vein kidney transplant

Renal transplantation remains the definitive treatment for end‐stage renal disease (ESRD). The shorter renal vein in right donor nephrectomies is associated with higher incidence of technical failure. We present here our experience with autologous internal jugular vein (IJV) conduits to facilitate living‐donor transplants. Six patients underwent right, living‐donor kidney transplant with simultaneous IJV harvest over a 1‐year period. All had bilateral jugular duplex scans preoperatively and were placed on aspirin 81 mg postoperatively. Patient demographics, comorbidities, and laboratories were retrospectively queried. Postoperative follow‐up and examination were performed per institutional protocol. The mean age and BMI were 51 ± 4.6 years and 30 ± 1.4 kg/m2, respectively. An average 4.5 ± 0.5 cm of IJV was taken, and anastomosed exsitu, end to end to the renal vein. One patient developed a perinephric hematoma requiring reexploration and another expired during follow‐up from septic shock of unknown etiology; there were no harvest site complications or deep vein thrombosis. All had immediate and stable graft function at 3.8 ± 1.7 (range: 0.7‐11.3) months follow‐up. Mean serum creatinine and estimated glomerular filtration rate were 1.3 ± 0.1 mg/dL and 55 ± 2.4 mL/min/1.73 m2, respectively. Internal jugular vein extension of short right renal veins for kidney transplant is a viable technique for ESRD patients with promising results.

Surgical Reconstruction of the Cephalic Arch for the Management of Dysfunctional Brachiocephalic Arteriovenous Fistulas

ultrasound imaging at 1 year, 10 patients have no follow-up data (three of whom surgery was recently completed, seven of which were lost to followup), and eight patients experienced thrombosis. Stents extended into the inferior vena cava crossing the normal contralateral side in 45 of 66 patients (68%). Seven of these patients (15%) suffered new thrombosis of the nonstented contralateral side. Three of these seven patients were totally noncompliant with their postoperative anticoagulation; thus, 8% of compliant patients had new contralateral thrombosis after stenting across a normal contralateral common iliac vein and into the vena caval wall. Conclusions: To date, there is no consensus whether to stent across the thrombosed common iliac vein into the cava or completely across and into the vena cava. From these data it appears that stenting across the iliocaval confluence can result in a small percentage of contralateral thrombosis despite chronic therapeutic anticoagulation. This data will help us move forward in the development of new technologies and in the treatment of these patients.