***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 and aims Laparoscopic surgery has become the treatment of choice for cholecystectomy . Many studies showed that while this approach benefits the patient , the surgeon faces such distinct disadvantages as a poor ergonomic situation and limited degrees of freedom with limited motion as a consequence . Robots have the potential to overcome these problems . To evaluate the efficiency and feasibility of robotically assisted surgery ( RAC ) , we design ed a prospect i ve study to compare it with st and ard laparoscopic cholecystectomy ( SLC ) . Material s and methods Between 2001 and 2003 , 26 patients underwent SLC and 20 patients underwent RAC using the ZEUS system .  The feasibility , safety , and possible advantages were evaluated . To assess the efficacy , the total time in the operating room was divided into preoperative , operative , and postoperative time frames . Results For RAC in comparison with SLC , the preoperative phase including equipment setup was significantly longer . In the intraoperative phase , the cut-closure time and camera and trocar insertion times were significantly longer . It is interesting to note that the net dissection time for the cystic artery , duct , and the gall bladder was not different from SLC . Conclusions The study demonstrates the feasibility of robotically assisted cholecystectomy without system-specific morbidity . There is time loss in several phases of robotic surgery due to equipment setup and deinstallation and therefore , presents no benefit in using the robot in laparoscopic cholecystectomy Although laparoscopic cholecystectomy has rapidly developed in the treatment of gall bladder disease in the absence of controlled clinical trial data its outcome parameters compared with open cholecystectomy remain unclear . A prospect i ve audit of the introduction of laparoscopic cholecystectomy in the west of Scotl and over a two year period was carried out to attempt to assess this new procedure . A total of 45 surgeons in 19 hospitals performing laparoscopic cholecystectomy su bmi tted prospect i ve data from September 1990 - 1992 . A total of 2285 cholecystectomies were audited ( a completed data collection rate of 99 % ) . Laparoscopic cholecystectomy was attempted in 1683 ( 74 % ) patients and completed in 1448 patients ( median conversion rate to the open procedure 17 % ) . The median operation time in the completed laparoscopic cholecystectomy patients was 100 minutes ( range 30 - 330 ) and overall hospital stay three days ( 1 - 33 ) . There were nine deaths ( 0.5 % ) after laparoscopic cholecystectomy although only two were directly attributable to the laparoscopic procedure . In the laparoscopic cholecystectomy group there were 99 complications ( 5.9 % ) , 53 ( 3 % ) of these were major requiring further invasive intervention . Forty patients ( 2.4 % ) required early or delayed laparotomy for major complications such as bleeding or bile duct injuries . There were 11 ( 0.7 % ) bile duct injuries in the laparoscopic cholecystectomy series , five were noted during the initial procedure and six were recognised later result ing from jaundice or bile leaks . Ductal injuries occurred after a median of 20 laparoscopic cholecystectomies . In conclusion laparoscopic cholecystectomy has rapidly replaced open cholecystectomy in the treatment of gall bladder disease . Although the overall death and complication rate associated with laparoscopic cholecystectomy is similar to open cholecystectomy , the bile duct injury rate is higher Background The aim of this study was to examine the advantages and risks of the Automated Endoscopic System for Optical Positioning ( AESOP ) 3000 robot system during uncomplicated laparoscopic cholecystectomies or laparoscopic hernioplasty . Methods In a r and omized study , we examined two groups of 120 patients each with the diagnosis cholecystolithiasis respectively the unilateral inguinal hernia . We worked with the AESOP 3000 , a robotic arm system that is voice-controlled by the surgeon . The subjective and objective comfort of the surgeon as well as the course and length of the operation were measured . Results The robot-assisted operations required significantly longer preparation and operation times . With regard to the necessary comm and s and manual camera corrections , the assistant group was favored . The same was true for the subjective evaluation of the surgical course by the surgeon . Conclusions Our study showed that the use of AESOP during laparoscopic cholecystectomy and hernioplasty is possible in 94 % of all cases . The surgeon must accept a definite loss of comfort as well as a certain loss of time against the advantage of saving on personnel OBJECTIVES To analyze sources search ed in Cochrane review s , to determine the proportion of trials included in review s that are indexed in major data bases , and to compare the quality of these trials with those from other sources . METHODS All new systematic review s in the Cochrane Library , Issue1 2001 , that were restricted to r and omized controlled trials ( RCTs ) or quasi- RCTs were selected . The sources search ed in the review s were recorded , and the trials included were checked to see whether they were indexed in four major data bases . Trials not indexed were checked to determine how they could be identified . The quality of trials found in major data bases was compared with those found from other sources . RESULTS The range in the number of data bases search ed per review ranged between one and twenty-seven . The proportion of the trials in the four data bases were Cochrane Controlled Trials Register = 78.5 % , MEDLINE = 68.8 % , Embase = 65.0 % , and Science/Social Sciences Citation Index = 60.7 % . Search ing another twenty-six data bases after Cochrane Controlled Trials Register ( CCTR ) , MEDLINE , and Embase only found 2.4 % additional trials . There was no significant difference between trials found in the CCTR , MEDLINE , and Embase compared with other trials , with respect to adequate allocation concealment or sample size . CONCLUSIONS There was a large variation between review s in the exhaustiveness of the literature search es . CCTR was the single best source of RCTs . Additional data base search ing retrieved only a small percentage of extra trials . Contacting authors and manufacturers to find unpublished trials appeared to be a more effective method of obtaining the additional better quality trials A r and om sample of 4,807 men and women , aged 30 , 40 , 50 , and 60 years , who lived in the western part of Copenhagen County , was drawn from the National Central Person Registry . A total of 226 subjects who were not of Danish origin were omitted . The response rate was 78.8 % ( 3,608/4,581 ) . Each person had his or her gallbladder examined by ultrasonography . The examinations took place between November 1982 and February 1984 . The overall prevalence of gallstone disease ( cases with stones and cholecystectomized cases ) in males aged 30 , 40 , 50 , and 60 years was 1.8 % , 1.5 % , 6.7 % , and 12.9 % , respectively . The corresponding prevalence in females was 4.8 % , 6.1 % , 14.4 % , and 22.4 % , respectively . Differences according to sex were significant in all age groups . Differences between the 40- and 50-year and 50- and 60-year age groups were significant in both sexes . Among subjects with gallstone disease , the disease was unknown to the prob and in the majority of males and in the 30-year-old females , but only in half of the women aged 40 , 50 , and 60 years . The prevalence of clinical ly diagnosed gallstones was not significantly different between respondents and nonrespondents This study found that robotic and telerobotic operations were accomplished with the same mortality , morbidity , blood loss , length of operations and length of stay . The DaVinci operations required longer total operating room time than the AESOP operations . Telerobotic laparoscopic cholecystectomy achieved the same clinical outcomes as st and ard robotic laparoscopic cholecystectomy in this small trial . This study justifies further comparison of these techniques in a r and omized prospect i ve trial Methods for combining data from several studies exist and appear to be quite useful . None satisfactorily addresses the question of what studies should be combined . This issue is the most serious method ological limitation . Even studies with statistically significant interaction might still be combined if the effect were in the same direction . Thus , substantial scientific input is required as to what criteria must be met by each potential study . Much can be learned from combining or pooling data but it must be done cautiously . Pooling exercises do not replace well design ed prospect i ve clinical trials . Efforts for establishing basic design criteria to allow for multicentre and multicountry trials to be more easily combined might be useful . BACKGROUND The robotic surgical system overcomes many technological obstacles of conventional laparoscopic surgery , and possesses enormous clinical applied potential . The aim of this study was to compare the efficacy of Zeus robot-assisted laparoscopic cholecystectomy with conventional laparoscopic cholecystectomy . METHODS Forty patients undergoing elective cholecystectomy were r and omly divided into two groups . Patients in group A ( n=20 ) underwent Zeus robot-assisted laparoscopic cholecystectomy , and patients in group B ( n=20 ) received conventional laparoscopic cholecystectomy .  The parameters on operative field , operative time , the number of actions , the rate of operative errors and minimal trauma were evaluated and compared between the two groups . RESULTS The number of clearing camera ( 1.1+/-1.0 times ) and the time of adjusting the operative field ( 2.2+/-0.7 minutes ) in group A were significantly less than those ( 4.5+/-1.5 times ) and ( 7.5+/-1.2 minutes ) in group B. The number of dissection actions ( 337+/-86 times ) and the rate of operative errors ( 10 % ) in group A were less than those ( 389+/-94 times ) , ( 25 % ) in group B. The total operation time ( 104.9+/-20.5 minutes ) and setup time ( 29.5+/-9.8 minutes ) in group A were significantly longer than those ( 78.6+/-17.1 minutes ) , ( 12.6+/-2.5 minutes ) in group B. Blood loss and postoperative hospitalization were similar . No postoperative complications occurred in both groups , and open cholecystectomy was performed in each group . CONCLUSIONS Zeus robot-assisted cholecystectomy inherits the benefits of minimally invasive surgery . The Zeus robotic surgical system is better than conventional laparoscopic technique in controlling the operative field and can be manipulated precisely and stably though it requires more operative time Background : The efficacy of conventional laparoscopic cholecystectomy ( CLC ) was compared with robot-assisted laparoscopic cholecystectomy ( RLC ) .  Surgical trainees performed the LC to avoid the surgeon ’s experience bias . Methods : Two surgical trainees performed 10 CLCs and 10 RLCs at r and om with a Zeus-Aesop Surgical Robotic System . The primary efficacy parameters were the total time and the number of actions involved in the procedure . The secondary parameters were setup and dissection times , and the number of grasping and dissection actions . Surgical complications were evaluated . Results : For CLC and RLC , respectively , the total times were 95.4 ± 28 min and 123.5 ± 33.3 min and the total actions were 420 ± 176.3 and 363.5 ± 158.2 . For CLC , the times required for setup ( 21 ± 10.4 min ) and dissection ( 50.2 ± 17.7 min ) were less than for RLC ( 33.8 ± 11.3 min and 72 ± 24.3 min , respectively ) . The numbers of grasping and dissection actions were not significantly different : 41.4 ± 26.5 and 378 ± 173.7 , respectively , for CLC versus 48.9 ± 27 and 314.6 ± 141.9 , respectively , for RLC . Conclusion : Although feasible , RLC requires significantly more time than CLC because of slower performed actions Background : Instrument positioners can position and lock a laparoscopic instrument . This study uses time-action analysis to evaluate objective ly whether IPs can substitute for a surgical assistant efficiently and safely . Methods : In four hospitals , 78 laparoscopic cholecystectomies were r and omly assisted by a surgical assistant or an instrument positioner ( AESOP and PASSIST ) The efficiency and safety of laparoscopic cholecystectomies were analyzed with respect to time , number and type of actions , positioning accuracy , and peroperative complications . A question naire evaluated the difficulties for each operation and the comfort of instrument positioner use . Results : The PASSIST and AESOP were able to replace the surgical assistant during laparoscopic cholecystectomies without significantly changing either the efficiency or the safety of the operation . The question naire showed that the surgeons preferred to operate with an instrument positioner . Conclusion : This study assessed objective ly that instrument positioners can substitute for a surgical assistant efficiently and safely in elective laparoscopic cholecystectomies Background The role of the human camera holder during laparoscopic surgery keeps valuable personnel from other duties . EndoAssist is a robotic cameraholding device controlled by the operator ’s head movements . This 
    Output:
    
Although robot-assisted laparoscopic cholecystectomy appears safe , there seems to be no significant advantages over human-assisted laparoscopic cholecystectomy .