Computed Tomography-Guided Percutaneous Infiltrations for Piriformis Syndrome: A Single-Center Retrospective Study.

Piriformis syndrome (PS), first described by Yeoman in 1928, is a general term referring to low back pain, sciatica, and instability. PS has a 6% incidence rate worldwide. In this study, we aim to retrospectively evaluate the effectiveness of computed tomography (CT)-guided percutaneous infiltration in a series of consecutive PS patients who have symptoms that are refractory to conservative therapies. An institutional database search identified 20 such consecutive patients who underwent infiltration with a mixture of long-acting corticosteroid and local anesthetic. Preoperational evaluation included physical examination and magnetic resonance imaging. The correct position of the 22-gauge spinal needle was verified with CT scan after contrast medium injection. Pain measured before the procedure and at 1 wk and 1, 6, and 12 mo after the procedure was compared by means of a numeric visual scale (NVS) questionnaire. The mean pain score before CT-guided percutaneous infiltration was 8.95 ± 1.432 NVS units. This score was reduced to a mean value of 0.85 ± 0.933 units at 1 wk, 0.90 ± 0.852 at 1 mo, 1.10 ± 1.165 at 6 mo, and 1.20 ± 1.399 at 12 mo follow-up (p < 0.001). Two patients of 20 (10%) underwent a second infiltration that was performed at 7 and 10 d after the first, respectively. No complications were observed. CT-guided infiltration seems to be a feasible, efficacious, and safe approach for pain reduction and mobility improvement in patients with symptomatic PS.

Percutaneous microwave ablation of renal cell carcinoma using a high power microwave system: focus upon safety and efficacy.

OBJECTIVES: Percutaneous ablation is an expanding, minimally invasive approach for small- to medium-sized renal masses. The purpose of this study is to review safety, and mid-term efficacy of percutaneous microwave ablation (MWA) for Renal Cell Carcinoma (RCC) treatment using a high power microwave system. METHODS AND MATERIALS: Institutional database research identified 50 consecutive patients with a single lesion resembling renal cell carcinoma in CT and MRI who underwent percutaneous microwave ablation using a high power microwave system. All patients underwent biopsy on the same session with ablation using an 18G semi-automatic soft tissue biopsy needle. Contrast-enhanced computed tomography or magnetic resonance imaging was used for post-ablation follow-up. Patient and tumour characteristics, microwave technique, complications and pattern of recurrence were evaluated. RESULTS: Mean patient age was 74 years (male-female: 31-19). Average lesion size was 3.1 cm (range 2.0-4.3 cm). Biopsy results report RCC (n = 48), inflammatory myofibroblastic tumour (n = 1), and non-diagnostic sample (n = 1). The 3-year overall survival was 95.8% (46/48). Two patients died during the 3-year follow-up period due to causes unrelated to the MW ablation and to the RCC. Minor complications including haematomas requiring nothing but observation occurred at 4% (2/50) of the cases. Local recurrence of 6.25% (3/48) was observed with 2/3 cases being re-treated achieving a total clinical success of 97.9% (47/48 lesions). CONCLUSIONS: Percutaneous microwave ablation of RCC using a high power microwave system is a safe and efficacious technique for the treatment of small- to medium-sized renal masses.

Percutaneous Biopsy and Radiofrequency Ablation of Osteoid Osteoma with Excess Reactive New Bone Formation and Cortical Thickening Using a Battery-Powered Drill for Access: A Technical Note.

PURPOSE: To report our experience with the use of a battery-powered drill in biopsy and radiofrequency ablation of osteoid osteoma with excess reactive new bone formation. The battery-powered drill enables obtaining the sample while drilling. MATERIALS AND METHODS: During the last 18 months, 14 patients suffering from painful osteoid osteoma with excess reactive new bone formation underwent CT-guided biopsy and radiofrequency ablation. In order to assess and sample the nidus of the osteoid osteoma, a battery-powered drill was used. Biopsy was performed in all cases. Then, coaxially, a radiofrequency electrode was inserted and ablation was performed with osteoid osteoma protocol. Procedure time (i.e., drilling including local anesthesia), amount of scans, technical and clinical success, and the results of biopsy are reported. RESULTS: Access to the nidus through the excess reactive new bone formation was feasible in all cases. Median procedure time was 50.5 min. Histologic verification of osteoid osteoma was performed in all cases. Radiofrequency electrode was coaxially inserted within the nidus and ablation was successfully performed in all lesions. Median amount CT scans, performed to control correct positioning of the drill and precise electrode placement within the nidus was 11. There were no complications or material failure reported in our study. CONCLUSIONS: The use of battery-powered drill facilitates access to the osteoid osteoma nidus in cases where excess reactive new bone formation is present. Biopsy needle can be used for channel creation during the access offering at the same time the possibility to extract bone samples.