A Meta-analysis of Combined Aspiration Catheter and Stent Retriever versus Stent Retriever Alone for Large-Vessel Occlusion Ischemic Stroke.

BACKGROUND: The efficacy of combined aspiration catheter and stent retriever compared with stent retriever alone for the treatment of large-vessel occlusion acute ischemic stroke is unclear. PURPOSE: Our aim was to conduct a systematic literature review and meta-analysis on several metrics of efficacy comparing aspiration catheter and stent retriever with stent retriever alone. DATA SOURCES: MEDLINE and the Cochrane Library Databases were searched. Randomized controlled trials and case-control and cohort studies were included. STUDY SELECTION: Ten comparative studies were included detailing a combined 1495 patients with aspiration catheter and stent retriever and 1864 with stent retrievers alone. DATA ANALYSIS: Data on first pass effect (TICI 2b/2c/3 after first pass), final successful reperfusion (modified TICI ≥2b), and 90-day functional independence (mRS ≤ 2) were collected. Meta-analysis was performed using a random-effects model. DATA SYNTHESIS: There was a pooled composite first pass effect of 40.8% (611/1495) versus 32.6% (608/1864) for aspiration catheter and stent retriever and stent retriever alone, respectively (P < .0001). Similarly, on a meta-analysis, aspiration catheter and stent retriever were associated with a higher first pass effect compared with stent retriever alone (OR = 1.63; 95% CI, 1.20-2.21; P = .002; I2 = 72%). There was no significant difference in composite rates of successful reperfusion between aspiration catheter and stent retriever (72.8%, 867/1190) and stent retriever alone (70.8%, 931/1314) (P = .27) or on meta-analysis (OR = 1.31; CI, 0.81-2.12; P = .27; I2 = 82%). No difference was found between aspiration catheter and stent retriever and stent retriever alone on 90-day functional independence (OR = 1.02; 95% CI, 0.77-1.36; P = .88; I2 = 40%). LIMITATIONS: This study is limited by high interstudy heterogeneity. CONCLUSIONS: On meta-analysis, aspiration catheter and stent retriever are associated with a superior first pass effect compared with stent retriever alone, but they are not associated with statistically different final reperfusion or functional independence.

Gene delivery to the spinal cord using MRI-guided focused ultrasound.

Non-invasive gene delivery across the blood-spinal cord barrier (BSCB) remains a challenge for treatment of spinal cord injury and disease. Here, we demonstrate the use of magnetic resonance image-guided focused ultrasound (MRIgFUS) to mediate non-surgical gene delivery to the spinal cord using self-complementary adeno-associated virus serotype 9 (scAAV9). scAAV9 encoding green fluorescent protein (GFP) was injected intravenously in rats at three dosages: 4 × 10(8), 2 × 10(9) and 7 × 10(9) vector genomes per gram (VG g(-1)). MRIgFUS allowed for transient, targeted permeabilization of the BSCB through the interaction of focused ultrasound (FUS) with systemically injected Definity lipid-shelled microbubbles. Viral delivery at 2 × 10(9) and 7 × 10(9) VG g(-1) leads to robust GFP expression in FUS-targeted regions of the spinal cord. At a dose of 2 × 10(9) VG g(-1), GFP expression was found in 36% of oligodendrocytes, and in 87% of neurons in FUS-treated areas. FUS applications to the spinal cord could address a long-term goal of gene therapy: delivering vectors from the circulation to diseased areas in a non-invasive manner.

The targeting accuracy of a preclinical MRI-guided focused ultrasound system.

PURPOSE: Assess the accuracy, precision, and sources of error using a preclinical MR-guided focused ultrasound system. METHODS: A preclinical focused ultrasound system, described previously [Chopra et al., Med. Phys. 36(5), 1867-1874 (2009)], was tested on a benchtop and with 3T GE, 3T Philips, and 7 T Bruker MR scanners for spatial targeting accuracy and precision. Randomly distributed water-filled holes drilled into a polystyrene plate were imaged using MRI and targeted using treatment planning software. The ultrasound focus of a 72 mm, f-number 0.8, 1.16 MHz transducer was aimed at the target locations, and 1-2 s continuous-wave sonications were performed on clear polystyrene plates to create localized spots of melted plastic. The distance between target and observed locations was measured and analyzed. Retrospective analysis of targeting accuracy was performed on preclinical data obtained from other experiments at their institution using the same system. RESULTS: The results suggest that the sources of targeting error under MR guidance can be roughly separated into three components--normally distributed random error; constant shift from inaccuracy in detection of the initial ultrasound focus; and angular misalignment between MR and focused ultrasound (FUS) coordinates. The lower bound on the targeting error was estimated to be 0.25 ± 0.13 mm, while the maximum observed targeting error did not exceed 2 mm. Measures required to reduce errors and improve targeting were developed to reduce the registration and misalignment errors such that maximum error was reduced to 0.36 ± 0.14 mm. Retrospective in vivo analysis indicated that the error was 1.02 ± 0.43 mm, including error extrinsic to the system. CONCLUSIONS: The FUS system, as described, is capable of precise and accurate sonications. The largest source of error--misregistration of the coordinate systems of the scanner and ultrasound system--was addressed which reduced the error to 0.36 ± 0.14 mm, sufficient for many preclinical applications.

Survival analysis and functional outcome of the Oxford unicompartmental knee replacement up to 11 years follow up at a District General Hospital.

BACKGROUND: There have been several large originator studies reporting excellent results with this prosthesis but far fewer large independent studies. We present, to our knowledge, the largest independent series documenting excellent survivorship rates and good functional outcomes at a mean follow up of 5.5 years post implantation of the Oxford unicompartmental knee replacement. METHODS: Our prospective study looks at the survivorship and the functional outcome of 364 Oxford UKRs performed in a district general hospital at a mean follow up of 5.5 years (range 5-11 years). Post operatively knees were assessed in a research clinic using the Oxford knees score (as well as the American Knee Society Score and the Hospital for Special Surgery Score). Maximal flexion was also measured. RESULTS: There were 26 revisions of 364 knees giving a survivorship, with revision as the end point, of 93% at a mean of 5.5 years post op (range 5-11 years). We achieved an Oxford score of 37.5, a mean AKSS of 161 (divided as American knee functional score 75.75/American knee objective score 85.4 (excellent)). The mean HSS score was 84.5. We achieved 'Excellent' Oxford knee scores in 137 knees (48%), 'Good' in 75 (26%), 'Moderate' in 51 (17%) and 'Poor' in only 27 (9%) of knees. Mean improvement in functional scores were: Oxford score (14.4), AKSS (71) and HSS (26.3). Mean maximal flexion was 123° range (110-140). CONCLUSIONS: We have confirmed that good medium to long-term function and survival can be obtained following Oxford medial knee replacement for treating anteromedial osteoarthritis, in our large independent series.