Austin C. Bourgeois

Improved Accuracy of Minimally Invasive Transpedicular Screw Placement in the Lumbar Spine With 3-Dimensional Stereotactic Image Guidance: A Comparative Meta-Analysis.

Study Design: This study compares the accuracy rates of lumbar percutaneous pedicle screw placement (PPSP) using either 2-dimensional (2-D) fluoroscopic guidance or 3-dimensional (3-D) stereotactic navigation in the setting of minimally invasive spine surgery (MISS). This represents the largest single-operator study of its kind and first comprehensive review of 3-D stereotactic navigation in the setting of MISS. Objective: To examine differences in accuracy of lumbar pedicle screw placement using 2-D fluoroscopic navigation and 3-D stereotaxis in the setting of MISS. Summary of Background Data: Surgeons increasingly rely upon advanced image guidance systems to guide minimally invasive PPSP. Three-dimensional stereotactic navigation with intraoperative computed tomography offers well-documented benefit in open surgical approaches. However, the utility of 3-D stereotaxis in the setting of MISS remains incompletely explored by few studies with limited patient numbers. Materials and Methods: A total of 599 consecutive patients underwent minimally invasive lumbar PPSP aided by 3-D stereotactic navigation. Postoperative imaging and medical records were analyzed for patient demographics, incidence and degree of pedicle breach, and other surgical complications. A total of 2132 screw were reviewed and compared with a meta-analysis created from published data regarding the placement of 4248 fluoroscopically navigated pedicle screws in the setting of MISS. Results: In the 3-D navigation group, a total of 7 pedicle breaches occurred in 6 patients, corresponding to a per-person breach rate of 1.15% (6/518) and a per-screw breach rate of 0.33% (7/2132). Meta-analysis comprised of data from 10 independent studies showed overall breach risk of 13.1% when 2-D fluoroscopic navigation was utilized in MISS. This translates to a 99% decrease in odds of breach in the 3-D navigation technique versus the traditional 2-D-guided technique, with an odds ratio of 0.01, (95% confidence interval, 0.01–0.03), P<0.001. Conclusions: Three-dimensional stereotactic navigation based upon intraoperative computed tomography imaging offers markedly improved accuracy of percutaneous lumbar pedicle screw placement when used in the setting of MISS.

The evolution of image-guided lumbosacral spine surgery

Techniques and approaches of spinal fusion have considerably evolved since their first description in the early 1900s. The incorporation of pedicle screw constructs into lumbosacral spine surgery is among the most significant advances in the field, offering immediate stability and decreased rates of pseudarthrosis compared to previously described methods. However, early studies describing pedicle screw fixation and numerous studies thereafter have demonstrated clinically significant sequelae of inaccurate surgical fusion hardware placement. A number of image guidance systems have been developed to reduce morbidity from hardware malposition in increasingly complex spine surgeries. Advanced image guidance systems such as intraoperative stereotaxis improve the accuracy of pedicle screw placement using a variety of surgical approaches, however their clinical indications and clinical impact remain debated. Beginning with intraoperative fluoroscopy, this article describes the evolution of image guided lumbosacral spinal fusion, emphasizing two-dimensional (2D) and three-dimensional (3D) navigational methods.

Bariatric Radioembolization: A Pilot Study on Technical Feasibility and Safety in a Porcine Model

PURPOSEnTo evaluate feasibility of left gastric artery (LGA) yttrium-90 ((90)Y) radioembolization as potential treatment for obesity in a porcine model.nnnMATERIALS AND METHODSnThis study included 8 young female pigs (12-13 weeks, 21.8-28.1 kg). Six animals received infusions of (90)Y resin microspheres (46.3-105.1 MBq) into the main LGA and the gastric artery arising from the splenic artery. Animal weight and serum ghrelin were measured before treatment and weekly thereafter. Animals were euthanized 69-74 days after treatment, and histologic analyses of mucosal integrity and ghrelin immunoreactive cell density were performed.nnnRESULTSnSuperficial mucosal ulcerations < 3.0 cm(2) were noted in 5 of 6 treated animals. Ghrelin immunoreactive cell density was significantly lower in treated versus untreated animals in the stomach fundus (13.5 vs 34.8, P < .05) and stomach body (11.2 vs 19.8, P < .05). Treated animals gained less weight than untreated animals over the study duration (40.2 kg ± 5.4 vs 54.7 kg ± 6.5, P = .053). Average fundic parietal area (165 cm(2) vs 282 cm(2), P = .067) and average stomach weight (297.2 g vs 397.0 g, P = .067) were decreased in treated versus untreated animals. Trichrome staining revealed significantly more fibrosis in treatment animals compared with control animals (13.0 vs 8.6, P < .05). No significant differences were identified in plasma ghrelin concentrations (P = .24).nnnCONCLUSIONSnLGA (90)Y radioembolization is promising as a potential treatment for obesity. A larger preclinical study is needed to evaluate the safety and efficacy of this procedure further.

Comments on: Intrahepatic Activity Distribution in Radioembolization with Yttrium-90-Labeled Resin Microspheres Using the Body Surface Area Method--A Less than Perfect Model.

microspheres (Embozene; CeloNova BioSciences, Inc, San Antonio, Texas). Following left PAE, the right prostatic artery was catheterized, and embolization with 100-μm Embozene particles was performed in the usual manner (Fig 4). The patient was discharged the same day with no complications occurring immediately after the procedure. After 6 months, the patient had sustained symptom improvement with a reduction in his American Urological Society Symptom Index score to 10 and a quality-of-life score of 2. He did report any change in his erectile dysfunction. Crossing of CTOs is well described and used in complex peripheral arterial disease. The experience we describe highlights the technique of crossing a CTO in the setting of a technically challenging PAE. Vascular anatomy in elderly male patients may not always be suitable for catheterization; however, the use of basic peripheral vascular techniques may allow for clinical and technical success. Our patient exhibited multiple risk factors for atherosclerotic disease, including a history of erectile dysfunction, which can be a vascular in nature. We do not routinely perform computed tomography angiography for planning purposes before embolization. A pitfall of computed tomography angiography is that it may not easily reveal complete occlusive disease of heavily calcified and small arteries or arteries with short segment occlusions or small caliber. Potential risks of crossing a prostatic artery CTO include dissection, vessel perforation or rupture, longer procedural time, and technical failure. Interventional radiologists performing PAE in men with greater risk for atherosclerotic occlusive disease may consider this technique.

Percutaneous Iliocaval Construction to Treat Symptomatic Chronic Lower Extremity Venous Insufficiency

A 65-year-old morbidly obese diabetic woman was referred for treatment of large bilateral nonhealing venous stasis ulcers along the medial right lower extremity (Fig 1). Computed tomography (CT) demonstrated no appreciable infrarenal vena cava or iliac veins, presumably as a result of longstanding occlusion or agenesis (Fig 2 and Video 1 [available online at www.jvir.org]). The right internal jugular and bilateral common femoral veins were accessed with 7-F sheaths. Bilateral femoral venograms showed extensive venous collateralization through lumbar and gonadal veins (Fig 3). A stiff Glidewire (Terumo Medical, Shibuya, Tokyo, Japan) and 5-F Tegtmeyer catheter (Cook Medical, Bloomington, Indiana)