Sidhartha Tavri

Catheter-Directed Intraarterial Thrombolysis as Part of a Multidisciplinary Management Protocol of Frostbite Injury

PURPOSE To evaluate intraarterial catheter-directed thrombolysis for prediction and prevention of delayed surgical amputation as part of multidisciplinary management of frostbite injury. MATERIALS AND METHODS A retrospective review was performed of 13 patients (11 men, 2 women; median age, 33.4 y; range, 8-62 y) at risk of tissue loss secondary to frostbite injury and treated with catheter-directed tissue plasminogen activator (t-PA) thrombolysis. Amputation data were assessed on follow-up (mean, 23 mo; range, 9-83 mo). Angiographic findings were classified into complete, partial, and no angiographic response and assessed for association with follow-up amputation rates. Correlation between amputation outcome and duration of cold exposure (mean, 23 h; range, 5-96 h), time between exposure and rewarming therapy (mean, 25.5 h; range, 7-95 h), and time between exposure and t-PA thrombolysis (mean, 32 h; range, 12-96 h) was assessed. Complications were recorded. RESULTS Of 127 digits at risk on baseline angiography that were treated with catheter-directed thrombolysis, complete recovery was seen in 106 (83.4%). Total mean t-PA dose per extremity was 27.5 mg (range, 12-48 mg) over a mean period of 34 hours (range, 12-72 h). Patients with complete angiographic response (8 patients; 79.5% of digits) did not require amputations; 4 of 5 patients (80%) with partial angiographic response (20.5% of digits) underwent amputation (P = .007). There was no significant correlation between amputation rates and duration of cold exposure (P = .9), time to rewarming therapy (P = .88), and time to thrombolysis (P = .56). Femoral access site bleeding in 2 patients was managed conservatively. One patient underwent surgical exploration for brachial artery hematoma. CONCLUSIONS Intraarterial catheter-directed thrombolysis should be included in initial management of frostbite injury, as it may prevent delayed amputations. The degree of angiographic response to thrombolysis can potentially predict amputation outcomes.

Incidence and interventions for post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is a venous stress disorder that develops from long-term effects from a previous deep venous thrombosis (DVT). The morbidity associated with PTS may be significant and patients can present with edema, chronic pain, swelling, skin changes, and heaviness of the affected limb. PTS can eventually lead to a decreased quality of life and to a marked burden for the healthcare system. This article elaborates on clinical aspects of PTS including the pathophysiology, diagnostic work-up and management of the disease with a particular focus on endovascular options.

Ultrasound characterization of slow precipitating implants for vascular occlusion

A current standard clinical treatment for liver cancer patients is drug eluting bead trans-arterial chemoembolization (DEB-TACE), where doxorubicin-loaded microparticles are injected via catheter into the hepatic artery that feeds the tumor. Due to the large bead diameter (∼200μm), occlusion occurs far away from the tumor creating a hypoxic region affecting both healthy and cancerous tissue. As an alternative to beads, we have developed a slow precipitating occlusion solution (sPI) which will be capable of continuous, deeper occlusion. Because the precipitation rate of the solution is critical to the penetration depth, and to the eventual success of this application, this study tested the feasibility of controlling solution precipitation by increasing polymer to solvent ratios and evaluating the occlusion distance using ultrasound imaging in a tissue-mimicking flow phantom.

Nonmaturing Fistulae: Epidemiology, Possible Interventions, and Outcomes

Autogenous arteriovenous fistulae are the best method for prolonged, successful dialysis access. However, a substantial limitation of dialysis fistulae is their high primary failure rate, estimated to be as high as 70% for radiocephalic fistulae. Fistula maturation is influenced by demographic risk factors as well as anatomical barriers, the latter of which can be readily identified by noninvasive ultrasound imaging and physical examination. These barriers can be categorized as inflow problems (native arterial disease, arteriovenous anastomotic stenosis, and juxta-anastomotic stenosis) or outflow problems (proximal venous stenosis or collateral veins). Venous stenoses represent the most commonly observed barrier to fistula maturation. By treating these barriers with a systematic approach, interventionalists can significantly improve the likelihood of a fistulas usability for dialysis.

Frostbite, Injury, and Trauma in the Extremities

Purpose of ReviewThe objective of the study is to review the current methods of evaluating and managing both frostbite injury and non-thermal extremity vascular trauma, with an emphasis on endovascular techniques.Recent FindingsThe traditional management of frostbite has a well-established role for the rapid rewarming of injured tissues. This literature review highlights the evolution of the various management techniques with a specific focus on the more recent role of intra-vascular catheter-directed thrombolytic therapy. Non-thermal extremity trauma with resulting vascular injury requires prompt diagnosis that relies heavily on both the physical examination and the appropriate imaging.SummaryFrostbite injury manifests as a progressive insult with distinct pathophysiologic phases during which imaging can guide appropriate care. Traditional medical management, in combination with intra-vascular catheter-directed thrombolytic regimens, can restore blood flow to poorly or non-perfused digits, thereby ultimately reducing the risk of delayed amputation. Non-thermal trauma to the extremities can result in a variety of vascular injuries. Interventional radiology plays a key role in diagnosis and an expanding role using transcatheter therapies in order to provide efficacious and optimal management of patients with vascular injury.