***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Remote ischaemic preconditioning attenuates cardiac injury at elective surgery and angioplasty . We tested the hypothesis that remote ischaemic conditioning during evolving ST-elevation myocardial infa rct ion , and done before primary percutaneous coronary intervention , increases myocardial salvage . METHODS 333 consecutive adult patients with a suspected first acute myocardial infa rct ion were r and omly assigned in a 1:1 ratio by computerised block r and omisation to receive  primary percutaneous coronary intervention with ( n=166 patients ) versus without ( n=167 ) remote conditioning ( intermittent arm ischaemia through four cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff ) . Allocation was concealed with opaque sealed envelopes . Patients received remote conditioning during transport to hospital , and primary percutaneous coronary intervention in hospital . The primary endpoint was myocardial salvage index at 30 days after primary percutaneous coronary intervention , measured by myocardial perfusion imaging as the proportion of the area at risk salvaged by treatment ; analysis was per protocol . This study is registered with Clinical Trials.gov , number NCT00435266 . FINDINGS 82 patients were excluded on arrival at hospital because they did not meet inclusion criteria , 32 were lost to follow-up , and 77 did not complete the follow-up with data for salvage index . Median salvage index was 0.75 ( IQR 0.50 - 0.93 , n=73 ) in the remote conditioning group versus 0.55 ( 0.35 - 0.88 , n=69 ) in the control group , with median difference of 0.10 ( 95 % CI 0.01 - 0.22 ; p=0.0333 ) ; mean salvage index was 0.69 ( SD 0.27 ) versus 0.57 ( 0.26 ) , with mean difference of 0.12 ( 95 % CI 0.01 - 0.21 ; p=0.0333 ) . Major adverse coronary events were death ( n=3 per group ) , reinfa rct ion ( n=1 per group ) , and heart failure ( n=3 per group ) . INTERPRETATION Remote ischaemic conditioning before hospital admission increases myocardial salvage , and has a favourable safety profile . Our findings merit a larger trial to establish the effect of remote conditioning on clinical outcomes . FUNDING Fondation Leducq BACKGROUND The benefits of preoperative biliary drainage , which was introduced to improve the postoperative outcome in patients with obstructive jaundice caused by a tumor of the pancreatic head , are unclear . METHODS In this multicenter , r and omized trial , we compared preoperative biliary drainage with surgery alone for patients with cancer of the pancreatic head . Patients with obstructive jaundice and a bilirubin level of 40 to 250 micromol per liter ( 2.3 to 14.6 mg per deciliter ) were r and omly assigned to undergo either preoperative biliary drainage for 4 to 6 weeks , followed by surgery , or surgery alone within 1 week after diagnosis . Preoperative biliary drainage was attempted primarily with the placement of an endoprosthesis by means of endoscopic retro grade cholangiopancreatography . The primary outcome was the rate of serious complications within 120 days after r and omization . RESULTS We enrolled 202 patients ; 96 were assigned to undergo early surgery and 106 to undergo preoperative biliary drainage ; 6 patients were excluded from the analysis . The rates of serious complications were 39 % ( 37 patients ) in the early-surgery group and 74 % ( 75 patients ) in the biliary-drainage group ( relative risk in the early-surgery group , 0.54 ; 95 % confidence interval [ CI ] , 0.41 to 0.71 ; P<0.001 ) . Preoperative biliary drainage was successful in 96 patients ( 94 % ) after one or more attempts , with complications in 47 patients ( 46 % ) . Surgery-related complications occurred in 35 patients ( 37 % ) in the early-surgery group and in 48 patients ( 47 % ) in the biliary-drainage group ( relative risk , 0.79 ; 95 % CI , 0.57 to 1.11 ; P=0.14 ) . Mortality and the length of hospital stay did not differ significantly between the two groups . CONCLUSIONS Routine preoperative biliary drainage in patients undergoing surgery for cancer of the pancreatic head increases the rate of complications . ( Current Controlled Trials number , IS RCT N31939699 . OBJECTIVE : To compare overlapping repair with end-to-end repair of obstetric tears  and to investigate which procedure results in a higher rate of flatal incontinence . METHODS : One-hundred forty-nine primiparous women sustaining a complete third- or a fourth-degree tear of the perineum were assigned r and omly to a primary sphincter repair using either an end-to-end ( n=75 ) or an overlapping surgical technique ( n=74 ) using 3–0 polyglyconate . Outcome measures at 6 months included rates of flatal and fecal incontinence , quality -of-life scores , integrity of the internal and external anal sphincters by anal ultrasonography , and anal sphincter function as reflected by anal manometry . RESULTS : Women who underwent overlapping repair compared with end-to-end repair had higher rates of flatal incontinence , 61 % compared with 39 % ( odds ratio [ OR ] 2.44 , confidence interval [ CI ] 1.2–5.0 ) . The rate of fecal incontinence was also higher , 15 % compared with 8 % ( OR 1.97 , CI 0.62–6.3 ) but did not attain statistical significance . Rates of internal and external anal sphincter defects did not differ significantly between groups and did not correlate with anal incontinence symptoms . Fecal incontinence was higher when there was a defect in both sphincter muscles . Anal sphincter function as assessed by manometry did not differ significantly between groups . CONCLUSION : End-to-end repair of third- or fourth-degree obstetric anal sphincter tears is associated with lower rates of anal incontinence when compared with overlapping repair . Clinical Trial Registration : IS RCT N Register , is rct n.org , IS RCT N04149919 . LEVEL OF EVIDENCE : Endovenous laser ablation ( EVLA ) and radiofrequency ablation ( RFA ) are both associated with excellent technical , clinical and patient‐reported outcomes for the treatment of varicose veins . The aim of this study was to compare the techniques in a r and omized clinical trial This multicentre r and omized clinical trial studied how symptoms improved after either stapled anopexy or diathermy excision of haemorrhoids Background : This r and omized controlled trial was design ed to compare the most common technique for open mesh repair ( Lichtenstein ) with the currently preferred minimally invasive technique ( total extra peritoneal , TEP ) for the surgical correction of inguinal hernia . Methods : A total of 660 patients were r and omized to Lichtenstein or TEP procedure .  Primary outcomes were postoperative pain , length of hospital stay , period until complete recovery , and quality of life ( QOL ) . Recurrences , operating time , complications , chronic pain , and costs were secondary endpoints . This study was registered at www . clinical trials.gov and carries the ID : NCT00788554 . Results : About 336 patients were r and omized to TEP , and 324 to Lichtenstein repair . TEP was associated with less postoperative pain until 6 weeks postoperatively ( P = 0.01 ) . Chronic pain was comparable ( 25 % vs. 29 % ) . Less impairment of inguinal sensibility was seen after TEP ( 7 % vs. 30 % , P = 0.01 ) . Mean operating time for a unilateral hernia with TEP was longer ( 54 vs. 49 minutes , P = 0.03 ) but comparable for bilateral hernias . Incidence of adverse events during surgery was higher with TEP ( 5.8 % vs. 1.6 % , P < 0.004 ) , but postoperative complications ( 33 % vs. 33 % ) , hospital stay and QOL were similar . After TEP , patients had a faster recovery of daily activities ( ADL ) and less absence from work ( P = 0.01 ) . After a mean follow-up of 49 months , recurrences ( 3.8 % vs. 3.0 % , P = 0.64 ) and total costs ( & U20AC;3.096 vs. & U20AC;3.198 ) were similar . Conclusion : TEP procedure was associated with more adverse events during surgery but less postoperative pain , faster recovery of daily activities , quicker return to work , and less impairment of sensibility after 1 year . Recurrence rates and chronic pain were comparable . TEP is recommended in experienced h and BACKGROUND Necrotizing pancreatitis with infected necrotic tissue is associated with a high rate of complications and death . St and ard treatment is open necrosectomy . The outcome may be improved by a minimally invasive step-up approach . METHODS In this multicenter study , we r and omly assigned 88 patients with necrotizing pancreatitis and suspected or confirmed infected necrotic tissue to undergo  primary open necrosectomy or a step-up approach to treatment . The step-up approach consisted of percutaneous drainage followed , if necessary , by minimally invasive retroperitoneal necrosectomy . The primary end point was a composite of major complications ( new-onset multiple-organ failure or multiple systemic complications , perforation of a visceral organ or enterocutaneous fistula , or bleeding ) or death . RESULTS The primary end point occurred in 31 of 45 patients ( 69 % ) assigned to open necrosectomy and in 17 of 43 patients ( 40 % ) assigned to the step-up approach ( risk ratio with the step-up approach , 0.57 ; 95 % confidence interval , 0.38 to 0.87 ; P=0.006 ) . Of the patients assigned to the step-up approach , 35 % were treated with percutaneous drainage only . New-onset multiple-organ failure occurred less often in patients assigned to the step-up approach than in those assigned to open necrosectomy ( 12 % vs. 40 % , P=0.002 ) . The rate of death did not differ significantly between groups ( 19 % vs. 16 % , P=0.70 ) . Patients assigned to the step-up approach had a lower rate of incisional hernias ( 7 % vs. 24 % , P=0.03 ) and new-onset diabetes ( 16 % vs. 38 % , P=0.02 ) . CONCLUSIONS A minimally invasive step-up approach , as compared with open necrosectomy , reduced the rate of the composite end point of major complications or death among patients with necrotizing pancreatitis and infected necrotic tissue . ( Current Controlled Trials number , IS RCT N13975868 . SUMMARY We consider the analysis of clinical trials that involve r and omization to an active treatment  ( T = 1 ) or a control treatment ( T = 0 ) , when the active treatment is subject to all-or-nothing compliance . We compare three approaches to estimating treatment efficacy in this situation : as-treated analysis , per- protocol analysis , and instrumental variable ( IV ) estimation , where the treatment effect is estimated using the r and omization indicator as an IV . Both model- and method -of-moment based IV estimators are considered . The assumptions underlying these estimators are assessed , st and ard errors and mean squared errors of the estimates are compared , and design implication s of the three methods are examined . Extensions of the methods to include observed covariates are then discussed , emphasizing the role of compliance propensity methods and the contrasting role of covariates in these extensions . Methods are illustrated on data from the Women Take Pride study , an assessment of behavioral treatments for women with heart disease PURPOSE We characterized the clinicopathological changes after transarterial chemoembolization for treatment of Wilms tumor . MATERIAL S AND METHODS A total of 44 consecutive patients with Wilms tumor were r and omized to undergo transarterial chemoembolization preoperatively or to undergo surgery only . We compared the clinicopathological findings of resected tumor from the 2 groups . RESULTS Tumor-free survival at 2 years in the group undergoing transarterial chemoembolization was significantly higher compared to the control group ( p < 0.01 ) , and tumor related recurrence and deaths within 1 year were significantly lower in the study group than in controls ( p < 0.01 ) . Average tumor shrinkage was 48.2 % in the study group . Average area of necrosis in tumor sections was 63.5 % in the study group and 15 % in controls ( AUC 2.78 , p < 0.01 ) . Percentage of tumor with moderate to severe interstitial fibrosis was 64 % ( 14 of 22 patients ) in the study group and 18 % ( 4 of 22 ) in controls ( AUC 2.72 , p < 0.01 ) . Comparative rates of percentage of tumor demonstrating grade III to IV lymphocyt 
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Conclusions The reporting of non-compliance to allocation and the h and ling of missing data were typically suboptimal .