Erik L. Owens

Spinal cord ischemia occurring in association with induced hypotension for colonic surgery.

A 19-year-old woman underwent an ileoanal pull-through. Intraoperatively, deepening of anesthesia was associated with reduced bleeding. Therefore, induced hypotension, mean arterial blood pressure 50 to 55 mm Hg, was maintained for 2.5 hours. Postoperatively, the patient was paraplegic with spinal cord infarction on magnetic resonance imaging from T9 to the tip of the conus medullaris. The collateralization of the anterior spinal artery is very variable and it seems likely that in this individual induced hypotension was associated with inadequate blood flow in the distribution of the artery of Adamkiewicz.

Congenital Agenesis of Inferior Vena Cava: A Rare Cause of Unprovoked Deep Venous Thrombosis

Congenital anomalies of the inferior vena cava (IVC), although rare, are a risk factor for lower limb deep venous thrombosis (DVT). A 19-year-old male presented with a left flank and groin pain caused by iliofemoral venous thrombosis. Vascular imaging by computed tomography (CT) scanning and venography demonstrated agenesis of the IVC. Catheter-directed thrombolysis via a popliteal vein was attempted but did not alter the patency of the common femoral vein outflow collaterals into the retroperitoneal azygous venous system. The patient was anticoagulated using systemic heparin infusion and clinical symptoms resolved within 5 days. He was transitioned to oral Coumadin anticoagulation, and follow-up venous duplex testing demonstrated no infrainguinal DVT and phasic venous flow with respiration in the femoral vein indicating patent collateral veins. Anomalies of the IVC are present in 0.3-0.5% of otherwise healthy individuals. Agenesis of the IVC has an incidence of 0.0005-1% in the general population but is found in almost 5% of patients <30 years of age with unprovoked lower limb DVT. In adults, IVC agenesis anomaly can cause diagnostic problems in the paravertebral area because of the tumor-like appearance of the azygous venous collaterals on noncontrast CT imaging. In young adults presenting with unprovoked lower limb DVT, the presence of an IVC anomaly should be considered and evaluated for by venous duplex testing and if necessary CT venography.

Intervention after endovascular aneurysm repair: Endosalvage techniques including perigraft arterial sac embolization and endograft relining

Endovascular aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysm (AAA). However, persistent AAA sac endoleak following EVAR can result in sac diameter increase requiring re-intervention in up to one-third of cases and even result in aneurysm rupture. In this case review, we summarize and detail endovascular re-interventions for each type of endoleak. We also detail specific options including stent-graft relining for indeterminate, Type III, and Type IV endoleaks and perigraft arterial sac embolization to induce thrombosis and resolve acute Type I, II, or III endoleaks. Endograft relining involves placement of a new stent-graft-elevating the bifurcation and extending the repair from renal artery to hypogastric arteries; perigraft arterial sac embolization involves placement of a catheter into the excluded sac from common femoral artery access, characterization of the inflow and outflow of the endoleak, and inducing cessation of the blood flow into the sac by the administration of thrombogenic material. Endoleaks range from low-pressure endoleaks, which can be safely monitored in a surveillance program to high-pressure endoleaks, which mandate intervention when associated with AAA sac diameter increase to protect from rupture. The evaluation of new devices and techniques to treat endoleak after EVAR remains an important issue in patient care after EVAR.