Percutaneous Retrieval of Venous Bullet Embolism.

PURPOSE: Bullet fragment embolization is a rare but potentially fatal complication of traumatic gunshot injury. Herein, we present a case of a patient who demonstrated migration of a bullet fragment from the lower chest into the left common iliac vein. Continual identification of foreign bodies on trauma imaging is of the utmost importance. Identifying and treating this rare entity can help vascular interventionalists improve patient outcomes. CASE REPORT: Our patient presented to the emergency room after sustaining 2 gunshot wounds to the right axilla. Initial imaging demonstrated 2 bullet fragments: one in the right axilla and another in the lower chest overlying the heart. A subsequent trauma computed tomography was performed 13 minutes later and demonstrated a bullet fragment in the left common iliac vein, which had embolized from the original location in the lower chest. Interventional radiology was consulted to perform foreign body removal. A transcutaneous approach was utilized, and the bullet embolus was removed successfully without complication. CONCLUSION: Bullet fragment embolization is a rare entity with complications ranging from critical limb ischemia to venous thrombosis or obstruction. This case helps to demonstrate the importance of identifying and accounting for bullet fragments in gunshot trauma imaging.

Aortic air embolus following pulmonary tumor radiofrequency ablation.

Aortic air embolism following a computed tomography (CT) guided percutaneous transthoracic procedure is a rare occurrence, but one that can have dire consequences. We present a case of a 48-year old female diagnosed with aortic air embolism during percutaneous radiofrequency ablation of a pulmonary mass. A large amount of intra-aortic air can be seen on the CT images just before the patient suffered acute cardiac arrest. Although this is a rare occurrence, recognition and management of this complication is important for physicians who perform any percutaneous transthoracic procedures.

Percutaneous image-guided radiofrequency ablation of painful metastases involving bone: a multicenter study.

PURPOSE: Few options are available for pain relief in patients with bone metastases who fail standard treatments. We sought to determine the benefit of radiofrequency ablation (RFA) in providing pain relief for patients with refractory pain secondary to metastases involving bone. PATIENTS AND METHODS: Thirty-one US and 12 European patients with painful osteolytic metastases involving bone were treated with image-guided RFA using a multitip needle. Treated patients had > or = 4/10 pain and had either failed or were poor candidates for standard treatments such as radiation or opioid analgesics. Using the Brief Pain Inventory-Short Form, worst pain intensity was the primary end point, with a 2-unit drop considered clinically significant. RESULTS: Forty-three patients were treated (median follow-up, 16 weeks). Before RFA, the mean score for worst pain was 7.9 (range, 4/10 to 10/10). Four, 12, and 24 weeks following treatment, worst pain decreased to 4.5 (P <.0001), 3.0 (P <.0001), and 1.4 (P =.0005), respectively. Ninety-five percent (41 of 43 patients) experienced a decrease in pain that was considered clinically significant. Opioid usage significantly decreased at weeks 8 and 12. Adverse events were seen in 3 patients and included (1) a second-degree skin burn at the grounding pad site, (2) transient bowel and bladder incontinence following treatment of a metastasis involving the sacrum, and (3) a fracture of the acetabulum following RFA of an acetabular lesion. CONCLUSION: RFA of painful osteolytic metastases provides significant pain relief for cancer patients who have failed standard treatments.

Validation of injection parameters for catheter-directed intraarterial gadolinium-enhanced MR angiography.

RATIONALE AND OBJECTIVES: Catheter-directed intraarterial (IA) injections of gadolinium contrast agents may be used during endovascular interventions with magnetic resonance (MR) imaging guidance. Injection protocols require further validation. Using a flow phantom and swine, the authors aimed to (a) measure the optimal arterial gadolinium concentration ([Gd]) required for MR angiography and (b) validate a proposed IA injection protocol for gadolinium-enhanced MR angiography. MATERIALS AND METHODS: For in vitro experiments, the authors placed a catheter in the aorta of an aorto-renal-iliac flow phantom. Injected [Gd], injection rates, and aortic blood flow rates were varied independently for 36 separate IA gadolinium injections. The authors performed 2D and 3D MR angiography with a fast spoiled gradient-recalled echo sequence. For subsequent in vivo experiments, they selectively placed catheters within the aorta, renal artery, or common iliac artery of three pigs. Injection rate and injected [Gd] were varied. The authors performed 32 separate IA gadolinium injections for 2D MR angiography. Signal-to-noise ratios (SNRs) were compared for the various combinations of injection rate and injected [Gd]. RESULTS: In vitro, an arterial [Gd] of 2%-4% produced an optimal SNR for 2D MR angiography, and 3%-5% was best for 3D MR angiography. In swine, an arterial [Gd] of 1%-4% produced an optimal SNR. In the phantom and swine experiments, SNR was maintained at higher injection rates by inversely varying the injected [Gd]. CONCLUSION: Dilute arterial [Gd] is required for optimal IA gadolinium-enhanced MR angiography. To maintain an optimal SNR, injection rates and injected [Gd] should be varied inversely. The postulated injection protocol was validated.