A Simple New Cost-Effective Retractor System for Exposure in Lumbar Microdiscectomy: 1-Year Outcome Analysis.

OBJECTIVE: To introduce a new technique for retraction in lumbar microdiscectomy, the rubber band technique (RT), and compare 1-year clinical outcomes of the technique with standard microdiscectomy (SM). METHODS: In this retrospective analysis, 81 consecutive patients with single-level lumbar disc herniation underwent lumbar microdiscectomy by either RT or SM. The primary outcome was Oswestry Disability Index score 1 year after surgery. Secondary outcomes included Short-Form Health Survey (SF-36) physical functioning subscale score, SF-36 bodily pain subscale score, and visual analog scale back pain and leg pain scores. Other parameters were operative time, hospital stay, skin incision, complications, and redo surgery. RESULTS: Of 81 patients, 93% (76 patients) had complete data up to 1-year follow up. The RT group comprised 39 patients (20 males, 19 females), and the SM group comprised 37 patients (19 males 18 females). Primary and secondary outcomes Oswestry Disability Index score, SF-36 physical functioning score, SF-36 bodily pain score, VAS back and leg pain scores, complications, and redo surgery did not differ significantly between the treatment groups at follow-up points (P > 0.05). Skin incision was smaller in the RT group compared with the SM group (P = 0.0001). CONCLUSIONS: Over the 1-year follow-up period, clinical outcomes of patients treated with RT were comparable to patients treated with SM. RT appears to be an alternative safe, effective, and economical approach for lumbar microdiscectomy.

Assessment of therapeutic response in patients with brain abscess using diffusion tensor imaging.

BACKGROUND: Accurate assessment of therapeutic response in patients with brain abscess (BA) is essential to direct appropriate therapy. This study was performed with an aim to see the treatment-induced changes in diffusion tensor imaging (DTI) indices (i.e., fractional anisotropy [FA] and mean diffusivity [MD]) in follow-up patients with BA after treatment. METHODS: Twenty patients with BA were prospectively studied in this study. Diffusion tensor imaging in first follow-up was done in all after 1 week and in 6 at 4 weeks of the initial study. RESULTS: The mean FA and MD values in first, second, and third studies were 0.28 +/- 0.03 and (0.81 +/- 0.07) x 10(-3) mm(2)/s, 0.18 +/- 0.09 and (1.08 +/- 0.09) x 10(-3) mm(2)/s, and 0.13 +/- 0.04 and (0.99 +/- 0.13) x 10(-3) mm(2)/s, respectively. The FA value was significantly (P < .01) decreased along with no significant change in MD value (P = .08) for 3 study periods. The mean volume (in milliliter) of the abscesses was 2.14 +/- 1.04, 1.34 +/- 0.45, and 0.77 +/- 0.14 in first, second, and third studies, respectively. CONCLUSIONS: We conclude that the reduction in FA value reflects the down-regulation of the neuroinflammatory molecules in response to treatment in patient with BA and may be used to assess therapeutic response in these patients in future.

Role of diffusion tensor imaging metrics and in vivo proton magnetic resonance spectroscopy in the differential diagnosis of cystic intracranial mass lesions.

The purpose of this study was to determine whether proton magnetic resonance spectroscopy (PMRS) and diffusion tensor imaging (DTI) indices, fractional anisotropy (FA) and mean diffusivity (MD) can be used to distinguish brain abscess from cystic brain tumors, which are difficult to distinguish by conventional magnetic resonance imaging (MRI). Fifty-three patients with intracranial cystic mass lesions and 10 normal controls were studied. Conventional MRI, PMRS and DTI of all the patients were performed on a 1.5-T GE scanner. Forty patients were with brain abscess and 13 with cystic tumors. Cytosolic amino acids (AAs) were present in 32 of 40 brain abscess patients. Out of 13 patients with cystic tumors, lactate and choline were seen in 3 and only lactate was present in 10 patients on PMRS. All 40 cases of abscess had high FA, while all 13 cases of tumor cysts had high MD values. We conclude that FA measurements are more sensitive in predicting the abscess, while PMRS and MD are more specific in differentiating abscess from cystic tumors. We suggest that PMRS should be combined with DTI rather than with diffusion-weighted imaging as FA can be used as an additional parameter for separation of abscess from other cystic intracranial mass lesions.