***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: Objective This prospect i ve r and omized study determined the influence of closed-suction drainage on the incidence of postoperative complications after elective hepatic resection . Summary Background Data Routine drainage is no longer advocated after several intra-abdominal surgical procedures . Methods A series of 81 patients who underwent elective hepatic resection were r and omly allocated to either a nondrainage group ( n = 39 ) and a drainage group with closed-suction drainage ( n = 42 ) . Indications for resection were 42 benign lesions and 39 malignant tumors , including 19 with cirrhosis . Major hepatic resection was performed in 25 patients and minor resection , in 56 . All patients underwent ultrasonography with puncture for bacteriologic cultures of all fluid collection s within the first 5 postoperative days . Results One patient died in each group . Ultrasonography found a significantly higher rate of subphrenic collection s in the drainage group compared with the nondrainage group ( respectively , 36 % vs. 15 % , p < 0.05 ) . These collection s were more frequently infected in the drainage group ( n = 6 ) than in the nondrainage group ( n = 2 ) . After major liver resection , the rate of intra-abdominal postoperative complications ( i.e. , subphrenic fluid collection s , hematomas , and bilomas ) was similar between the two groups . Conclusion Minor liver resection is safer without drainage . Major liver resection can be performed with or without abdominal drainage 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 Background and aims The clinical value of synbiotics in surgical patients remains unclear . The aim of this study was to investigate the effect of synbiotics on intestinal integrity and microflora , as well as on surgical outcome , in patients undergoing high-risk hepatectomy . Methods Fifty-four patients with biliary cancer were r and omly allocated to two groups before hepatectomy . One group received postoperative enteral feeding that included synbiotics ; the other received enteral feeding only .  Lactulose/mannitol ( L/M ) ratio , serum diamine oxidase ( DAO ) activity , and fecal microflora and organic acid concentrations were determined . Postoperative infectious complications were recorded . Results Of the 54 patients , 44 completed the trial ( 21 receiving synbiotics and 23 others as controls ) . Postoperative changes in L/M ratios and serum DAO activities were identical between the two groups . Numbers of beneficial bacteria increased in the synbiotics group after surgery but decreased in controls . Numbers of harmful microorganisms decreased in the synbiotics group but increased in controls . Total organic acid concentrations increased in the synbiotics group but decreased in controls . Incidence of infectious complications was 19 % ( 4/21 ) in the synbiotics group and 52 % ( 12/23 ) in controls ( P<0.05 ) . All study patients tolerated surgery ( mortality 0 % ) . Conclusions Synbiotics , combined with early enteral nutrition , can reduce postoperative infections . This beneficial effect presumably involves correction of an intestinal microbial imbalance induced by surgical stress Introduction : Despite advances in antibiotic prophylaxis , postoperative wound infection remains a major source of morbidity after digestive surgery . Its prevention is a challenging problem , especially in high-risk patients . The authors introduced a new method to prevent surgical wound infections and evaluated its efficacy in a prospect i ve , r and omized trial in markedly high-risk patients . Methods : Patients with biliary tract carcinoma who were scheduled to undergo combined liver and extrahepatic bile duct resection with biliary reconstruction were r and omly assigned to one of two groups , well matched in terms of clinical characteristics at baseline . In one group the new treatment was employed ( sealed group , n=31 ) , and in the other the wound was treated in the usual fashion ( open group , n=28 ) . In the sealed group , povidone-iodine gel was administered to the subcutaneous tissue , and the skin and peritoneum were approximated with a continuous suture .  Wound infection was registered up to 30 days after surgery . Results : Wound infection occurred in 18 patients : 5 ( 16 % ) patients in the sealed group and 13 ( 46 % ) in the open group ( P<0.05 ) . All 18 underwent preoperative percutaneous transhepatic biliary drainage and had positive  bile culture findings . In 13 of these 18 patients ( 72 % ) the micro-organisms isolated from the infected wound were identical to those in the bile . Conclusions : Our results confirm the close association between infected bile and wound infection in hepatobiliary surgery . Our new method , “ direct wound sealing , ” is simple , easy to perform , virtually cost-free , and has the potential to prevent wound infections even in markedly high-risk patients 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 . Objective To analyze postoperative leukocyte functions in patients undergoing hemihepatectomy  , and to assess the effect of treatment with the endotoxin-neutralizing agent bactericidal/permeability-increasing protein ( rBPI21 ) . Summary Background Data Extensive liver resection is associated with a high incidence of infectious complications . Because elimination of pathogenic microorganisms occurs mainly by leukocytes , this increased rate of infections is most likely due to an impaired function of these cells . Endotoxin , translocated from the gut into the systemic circulation as a result of increased gut permeability and reduced hepatic clearance function after major liver resection , may play an important role in the impairment of posthepatectomy leukocyte function . Methods To investigate whether hemihepatectomy results in impaired leukocyte functions and to determine the role of endotoxin in this process , leukocyte oxidative burst and leukocyte antigen expression were studied in three groups of patients : patients undergoing a hemihepatectomy and receiving rBPI21 treatment , patients undergoing hemihepatectomy and receiving placebo , and as an extra control group patients undergoing other major abdominal surgeries .  Blood sample s were collected before surgery , 2 hours after surgery , and at days 1 , 2 , 5 , and 7 . Phorbol myristate acetate-stimulated oxidative burst was measured using dihydrorhodamine , and leukocyte surface expression of the antigens CD11b , CD16 , and CD14 was investigated by indirect immunofluorescence . Both oxidative burst and membrane surface expression were quantified by flow cytometry . An indication of the antiendotoxin effect of rBPI21 treatment was provided by assessment of plasma lipopolysaccharide binding protein ( LBP ) levels by enzyme-linked immunosorbent assay . Results The oxidative burst in the hemihepatectomized patients receiving placebo and the controls increased 2 hours after surgery , whereas it decreased in the rBPI21-treated patients , result ing in significant differences between the groups . On day 1 , neutrophil CD11b expression and monocyte CD14 expression in the rBPI21-treated patients and controls were significantly lower than in the placebo group . At 2 hours , CD16 expression in the placebo-treated patients was significantly higher than in the rBPI21-treated patients and controls . On day 5 and day 7 , plasma LBP levels were significantly higher in the placebo-treated patients compared with the rBPI21-treated patients . Conclusions The results of this study show that patients undergoing major liver resection have an increased activation of leukocytes compared with those undergoing other major abdominal surgery . This enhanced activation may contribute to the increased risk of infection in these patients . Administration of the endotoxin-neutralizing agent rBPI21 to hemihepatectomy patients was shown to reduce plasma LBP levels , to preserve leukocyte functions partially , and to reduce leukocyte activation to the level of other , nonhepatic abdominal surgery OBJECTIVES Although the usefulness of antimicrobial prophylaxis for clean-contaminated surgery has been recognized , only a few r and omized controlled studies on the duration of administration after hepatectomy have been performed . We investigated the duration of antimicrobial prophylaxis after hepatectomy . METHODS The subjects were 180 patients who underwent hepatectomy without reconstruction of the biliary or intestinal tract between April 2003 and March 2006 at our department . The patients were r and omly allocated to groups to be treated with flomoxef sodium as antimicrobial prophylaxis for 2 days ( 89 patients ) or 5 days ( 91 patients ) , including the operation day . The presence or absence of systemic inflammatory response syndrome ( SIRS ) and infections was investigated . RESULTS No significant differences were noted in patient background between the two groups . Infections occurred in seven and six patients in the 2 day and 5 day treatment groups ( 7.9 % and 6.6 % ) , respectively , showing no significant difference between the two groups . No significant difference was noted when the cases were divided into surgical site infections and remote infections . The positive rate of SIRS was significantly higher in the 2 day treatment group than in the 5 day treatment group on days 2 and 3 after surgery . The risk factors in patients who developed infections were blood loss , operation time and the complication of biliary fistula . CONCLUSIONS Two day administration of flomoxef sodium may be sufficient for antimicrobial prophylaxis after hepatectomy . However , when SIRS is positive on post-operative day 2 , and induction of liver failure is of concern , it may be safer to continue antimicrobial drug administration until SIRS is eliminated PURPOSE A prospect i ve , r and omized trial was performed to determine if intra-abdominal drainage catheters are necessary after elective liver resection . PATIENTS AND METHODS Between April 1992 and April 1994 , 120 patients subjected to liver resection , stratified by extent of resection and by surgeon , were  r and omized to receive or not receive operative closed-suction drainage . Operative blood loss was not an exclusion criteria , and no patient who consented to the study was excluded . RESULTS Eighty-seven patients ( 73 % ) had resection of one hepatic lobe or more ( 27 lobectomies , 54 trisegmentectomies , and 6 bilobar atypical resections ) and 33 had less than a lobectomy ( 8 wedge resections or enucleations , 9 segmentectomies , and 16 bisegmentectomies ) . Eighty-four patients ( 70 % ) had metastatic cancer and 36 patients ( 30 % ) had primary liver pathology . There were no differences in outcome , including length of hospital stay ( no drain , 13.4 + /- 0.9 days ; drain , 13.1 + /- 0.8 days ; P = not significant [ NS ] ) , mortality ( no drain , 3.3 % ; drain , 3.3 % ) , complication rate ( no drain , 43 % ; drain , 48 % ; P = NS ) , or requirement for subsequent percutaneous drainage ( no drain , 18 % ; drain , 8 % ; P = NS ) . All infected collection s ( n = 3 ) occurred in operatively drained patients . Two other complications were directly related to the operatively placed 
    Output:
    
There was no significant differences in mortality or severe morbidity in any of the comparisons .
There is currently no evidence to support or refute the use of any treatment to reduce infectious complications after liver resections .