Tarlov cysts: an overlooked clinical problem.

Symptomatic Tarlov cysts typically cause chronic pelvic and lower extremity pain and sacral nerve root radiculopathy. Historically, open surgical treatment involved significant patient morbidity, particularly postoperative cerebrospinal fluid (CSF) leaks and infection. These CSF leaks often required multiple surgical procedures to seal. Over the past 20 years, there have been two or three isolated case reports of computed tomography (CT)-guided needle aspirations that offered limited evidence of treatment efficacy and safety. Some have reported high rates of postprocedure aseptic meningitis that were not well explained. These poor results dissuaded physicians from caring for these patients. As a group these patients are usually treated dismissively and told their cysts are asymptomatic and their pain must be coming from somewhere else. Many of them have had an unnecessary discectomy or a spinal fusion, and when these procedures did not relieve their pain they were told they are a "failed back patient." We have treated more than a hundred patients with symptomatic Tarlov cysts by CT fluoroscopic-guided needle aspiration and fibrin injection and have had excellent results with no meaningful complications and never a case of aseptic meningitis. We believe this is a safe, highly effective first-line treatment for symptomatic Tarlov cysts.

CT fluoroscopy: novel application for the treatment of ventricular pathologies.

INTRODUCTION: Recent advances in multidetector CT imaging (MDCT) provide real-time "fluoroscopic-like" capabilities with excellent spatial resolution. MDCT fluoroscopy expands our ability to perform image-guided interventions in anatomically complex locations. Although MDCT fluoroscopy is currently used at our institution for a variety of procedures ranging from spinal nerve blocks to RFA ablation, we believe these same techniques can be used to navigate within the ventricles of the central nervous system to treat conditions requiring placement of intraventricular catheters, depth electrodes, or potentially stents for the relief of CSF outlet obstruction. METHODS: Using three fresh, unfrozen human cadavers, we studied the feasibility of using MDCT fluoroscopy for intraventricular catheter placement and to stent the aqueduct of Sylvius. RESULTS: The ventricles were entered via a single needle pass and catheters were placed over the wire. Contrast agent was then injected to visualize the distribution. To stent the aqueduct of Sylvius, a wire was passed into the 4th ventricle and a coronary stent was then inserted over the wire and deployed. CONCLUSION: Based on our success with these procedures, we believe this technique can be used to limit complications and improve efficacy of a number of neurosurgical procedures.

A review of complications associated with vertebroplasty and kyphoplasty as reported to the Food and Drug Administration medical device related web site.

In 2002, approximately 38,000 vertebroplasties and 16,000 kyphoplasties were performed in the United States. As the use of both modalities for the treatment of vertebral compression fractures has increased, so have questions regarding safety and efficacy. The authors addressed this by reviewing both the current literature and complications data reported to the Food and Drug Administration (FDA) Center for Devices and Radiological Health through the on-line database (http://www.fda.gov/cdrh/maude.html) and through the Office of the Freedom of Information Act at the FDA. Although both procedures are largely safe, the FDA data highlight two main concerns: reactions to the use of acrylic (polymethylmethacrylate) bone cement, including hypotension and, in some cases, death, especially when multiple vertebral levels are treated in one setting; and a possible increased risk with kyphoplasty of pedicle fracture and cord compression.

Treatment considerations for vertebroplasty in men.

BACKGROUND AND PURPOSE: Vertebroplasty is now a widely accepted image-guided intervention in patients with compression fracture. The purpose of this report is to look specifically at the male population undergoing vertebroplasty and identfy the management considerations distinct to men. METHODS: The hospital medical records and radiographic studies of 24 men treated with vertebroplasty between February 1999 and November 2000 were retrospectively reviewed. RESULTS: Five patients presented with idiopathic or secondary osteoporosis. In two of these five men, malignancies were discovered by core biopsies taken at the time of vertebroplasty. Thirteen patients (54%) had secondary osteoporosis. Of this group, 10 patients (42%) were steroid dependent and three (13%) were hypogonadal. Five patients (21%) had traumatic events leading to fracture. One presented with known metastases. CONCLUSION: Primary osteoporosis in men is unusual. In male patients without a definable cause of osteoporosis, known metastatic disease, or a significant history of trauma, the routine performance of a vertebral biopsy through the vertebroplasty needle before the injection of bone cement is indicated to identify unexpected neoplasm.

The chemistry of acrylic bone cements and implications for clinical use in image-guided therapy.

Advances in image-guided therapy for vertebral fractures and other bone-related disorders have made acrylic bone cement an integral part of the interventional armamentarium. Unfortunately, information on the properties and chemistry of these compounds is mostly published in the biomaterial sciences literature, a source with which the interventional community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the properties of components in polymethylmethacrylate (PMMA)-based polymers, the most commonly used bone cements in interventional procedures such as percutaneous vertebroplasty. The effects of altering the concentration of components such as methylmethacrylate monomers, PMMA beads, benzoyl peroxide activator, N,N-dimethyl-p-toluidine (DMPT) initiator, and radiopacifiers on the setting time, polymerization temperature, and compressive strength of the cement are also considered. This information will allow interventional radiologists to manipulate bone cement characteristics for specific applications and maximize the clinical potential of image-guided interventions.