Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Input: Consider Input: To compare the safety and success of a retrograde approach using a microcatheter vs. a sheath in the treatment of superficial femoral artery (SFA) chronic total occlusions (CTOs).', 'From April 2007 to December 2012, 188 consecutive patients underwent EVT for 229 de novo SFA CTOs using the retrograde approach in 68 patients (35 men; mean age 72 years). This cohort was divided into cases performed with a 4-F or 6-F sheath (n=28, 36 limbs) and those with a 2.1-F microcatheter (n=35, 49 limbs). The primary outcomes were mean time to hemostasis and number of intra- and postoperative puncture site complications, as well as the success of popliteal artery puncture, lesion crossing, and reperfusion.', 'There were no significant differences between two groups in baseline characteristics. PA puncture was successful in all limbs, and the success in crossing the lesion with the wire was not significantly different (91.9% in the sheath group vs. 89.8% in the microcatheter group). Mean time to hemostasis was 8.9±8.8 minutes in the microcatheter group vs. 47.7±13 minutes in the sheath group (p<0.0001). There was a significant difference in intraoperative and postoperative complications (22.2% in the sheath group vs. 2.0% in the microcatheter group, p=0.002).

Output: Is a sheathless retrograde approach via the popliteal artery useful and safe for treating chronic total occlusions in the superficial femoral artery?


Input: Consider Input: MicroRNA-222 (miR-222) has been shown to play a potential oncogenic role in bladder cancer. The aim of this study was to evaluate the expression of miR-222 in bladder cancer and its potential relevance to clinicopathological characteristics and patient survival.', 'Surgical specimens of cancer tissue and adjacent normal tissue were obtained from 97 patients with bladder cancer. The relative expression levels of miR-222 in the cancer and the normal adjacent tissue were measured by quantitative reverse-transcriptase PCR. We analyzed their correlation with clinicopathological parameters and prognostic value.', 'The expression level of miR-222 was significantly higher in tumor tissues than in corresponding non-cancerous tissues (5.46\u2009±\u20091.45 versus 1.92\u2009±\u20090.65, P\u2009< \u20090.0001), and a high expression of miR-222 was found to be significantly associated with tumor grade (P\u2009=\u20090.003) and tumor stage (P\u2009=\u20090.005). The miR-222 expression level was classified as high or low in relation to the median value (cutoff value\u2009=\u20095.15). Kaplan-Meier analysis showed that patients with higher levels of miR-222 had significantly poorer survival than those with lower expression of this miRNA in patients, with a 5-year overall survival of 29.53% and 52.75%, respectively (P\u2009=\u20090.0034). In the multivariate Cox proportional hazards analysis, which included miR-222 level, tumor grade, tumor stage, and tumor number, high miR-222 expression was independently associated with poor survival (P\u2009<\u20090.001; hazard ratio 6.17; 95% CI 2.33 to 10.39).

Output: Is increased expression of miR-222 associated with poor prognosis in bladder cancer?


Input: Consider Input: The aim of this study is to evaluate if it is necessary to remove all the radioactive sentinel lymph nodes (SLNs) not seen on lymphoscintigraphy in order to accurately stage breast cancer patients.', 'From March 1999 to March 2006, SLN biopsy was performed in 461 patients. All patients were only injected with radioisotope. Lymphoscintigraphy was performed in all the patients. The mean number of SLNs removed was 2.1 (range 1-15).', 'The SLN was positive in 133 patients (28.8%). Lymphoscintigraphy accurately predicted the number of SLNs identified intraoperatively in 243 patients (52.7%). In 175 patients (37.9%) there were more SLNs identified intraoperatively than were seen on lymphos cintigraphy. In 11 (6.2%) of these 175 patients, additional SLNs identified intraoperatively harboured metastasis. Type of injection, need for a second injection, tumour location and age were not identified as statistically significantly associated with additional positive SLNs identified intraoperatively and not seen on lymphoscintigraphy.


Output: Does removal of all radioactive sentinel nodes in breast cancer improve the detection of positive sentinel nodes?