***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: Seventy consecutive cirrhotic patients with persistent or recurrent variceal bleeding were included in a clinical trial to compare the efficacy and safety of portacaval shunt ( PCS ) and stapler transection ( ST ) in patients with low surgical risk , and of stapler transection and endoscopic sclerotherapy ( ES ) in patients with high surgical risk . To classify the patients into low- and high-risk groups a new scoring system was used , based on an analysis of factors influencing operative mortality in an earlier series of emergency portacaval shunt . Thirty-eight low-risk patients were r and omly allocated for treatment with portacaval shunt  ( 19 patients ) or stapler transection ( 19 patients ) , and 32 high-risk patients for stapler transection ( 17 patients ) or ES ( 15 patients ) . The operative mortality of patients treated by PCS was close to that expected according to retrospective data , this indicating that the proposed scoring system is highly discriminant . In low-risk patients , portacaval shunt evidence d greater haemostatic efficacy and fewer complications than stapler transection . However , hepatic encephalopathy during follow-up was more frequent in the portacaval shunt group and there were no significant differences in operative mortality and long-term survival between the two groups . In high-risk patients , stapler transection and sclerotherapy had a similar haemostatic efficacy , operative mortality and long-term survival . However , sclerotherapy occasioned fewer complications than stapler transection . Our results motivate us to recommend stapler transection for low-risk patients and to consider sclerotherapy as an alternative for high-risk patients in the emergency treatment of uncontrolled variceal bleeding Portosystemic encephalopathy is a common complication of surgical portacaval shunts . Recently , transjugular intrahepatic portosystemic shunts have been proposed to produce portal decompression in a manner analogous to a side-to-side portacaval shunt , but with less morbidity . The incidence and clinical spectrum of portosystemic encephalopathy after transjugular intrahepatic portosystemic shunts , however , had not been previously prospect ively defined . We therefore prospect ively studied portosystemic encephalopathy in 30 patients undergoing transjugular intrahepatic portosystemic shunts and compared these findings with 25 patients concurrently undergoing sclerotherapy ( controls ) .  At entry , both study groups were comparable .  Portosystemic encephalopathy was assessed by examining and grading mental status , asterixis , plasma ammonia and trail making tests . The portosystemic encephalopathy index was calculated from these parameters . Nine of 30 patients with transjugular intrahepatic portosystemic shunts experienced 24 episodes of acute portosystemic encephalopathy during follow-up ; 6 of 9 had a history of portosystemic encephalopathy before transjugular intrahepatic portosystemic shunts and 5 of these 6 patients had Child C cirrhosis . Mental status and asterixis scores as well as portosystemic encephalopathy index worsened significantly in the first month after transjugular intrahepatic portosystemic shunts but showed some improvement thereafter . Increasing age , a medical history of portosystemic encephalopathy and trail scores for part B greater than 100 sec were predictors of portosystemic encephalopathy after transjugular intrahepatic portosystemic shunts . Portosystemic encephalopathy could be managed medically in all but one patient who underwent liver transplant . In contrast , there were no significant changes in mental status , asterixis , ammonia or trail scores over time in sclerotherapy controls . Only six episodes of encephalopathy occurred in endoscopic  sclerotherapy  patients over the duration of the study . Thus , overall risk of portosystemic encephalopathy after transjugular intrahepatic portosystemic shunts was higher than during sclerotherapy A prospect i ve r and omized trial was conducted in unselected , consecutive patients with bleeding esophageal varices result ing from cirrhosis comparing ( 1 ) emergency portacaval shunt performed within 8 hr of initial contact ( 21 patients ) with ( 2 ) emergency medical therapy ( intravenous vasopressin and esophageal balloon tamponade ) followed in 9 to 30 days by elective portacaval shunt in survivors ( 22 patients ) . All patients underwent the same diagnostic workup within 3 to 6 hr of initial contact , and received identical supportive therapy initially . All patients were followed up for at least 10 yr . The protocol contained no escape or crossover provisions . There were no statistically significant differences between the two treatment groups in the incidence of any of the clinical variables , results of laboratory tests or degree of portal hypertension . Child 's risk classes in the shunt group were A—2 patients , B—8 patients and C—11 patients , whereas in the medical group they were A—10 patients , B—5 patients , and C—7 patients , a significant difference ( p < 0.01 ) that might have favored emergency medical treatment . Bleeding was controlled initially and permanently by emergency shunt in every patient , but by medical therapy in only 45 % ( p < 0.001 ) . Mean requirement for blood transfusion was 7.1 ± 2.6 units in the shunt group and 21.4 ± 2.6 units in the medical group ( p < 0.001 ) . Eighty‐one percent of the patients in the shunt group were discharged alive compared with 45 % in the medical group ( p = 0.027 ) . Five‐ and 10‐yr observed survival rates were 67 % and 57 % , respectively , after emergency shunt compared with 18 % and 18 % , respectively , after the combination of emergency medical therapy and elective shunt ( p < 0.01 ) . These survival rates produced by emergency shunt performed within 8 hr of initial contact confirm the effectiveness of this procedure observed in our previous unr and omized studies . ( Hepatology 1994;20:863–872 ) BACKGROUND The transjugular-intrahepatic-portosystemic shunt is a new interventional treatment for portal hypertension . The aim of our study was to compare the transjugular shunt with endoscopic treatment for the prophylaxis of recurrent variceal bleeding . METHODS Between March , 1993 , and March , 1996 , 126 patients with variceal bleeding were r and omly assigned either transjugular shunt ( n = 61 ) or endoscopic treatment ( n = 65 ) . Patients were followed up for a median of 14 ( IQR 8 - 25 ) months and 13 ( 8 - 25 ) months , respectively . In 31 ( 51 % ) of the shunted patients , simultaneous transjugular-variceal embolisation was done at the time of shunt placement . Endoscopic treatment consisted of sclerotherapy and /or b and ing ligation and was combined with propranolol medication . FINDINGS Technical success was achieved in all patients assigned to the shunt group . During follow-up , the cumulative 1-year variceal rebleeding rates in the shunted and endoscopically treated patients were 15 % and 41 % and the 2-year rates were 21 % and 52 % ( p = 0.001 ) , respectively . In nine ( 12 % ) patients from the endoscopic group treatment failed and the patients received the transjugular-shunt treatment . A total of 19 bleeding episodes from any source occurred in 15 patients in the shunt group compared with 100 episodes in 33 patients in the endoscopic group . There was no difference in survival with estimated 1-year survival rates for shunted and endoscopically treated patients of 90 % and 89 % , and 2-year survival rates of 79 % and 82 % , respectively . The incidence of clinical ly significant hepatic encephalopathy after 1 year was higher in the shunt group ( 36 % vs 18 % , p = 0.011 ) . INTERPRETATION These results suggest , that the transjugular shunt is more effective than endoscopic treatment in prevention of variceal rebleeding but has a considerable risk of hepatic encephalopathy . Survival is similar in the two groups 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 METHODS We compared propranolol therapy and endoscopic ligation for the primary prevention of  bleeding from esophageal varices . This prospect i ve , controlled trial included consecutive eligible patients who had large varices ( > 5 mm in diameter ) that were at high risk for bleeding . The patients were assigned to either propranolol therapy , at a dose sufficient to decrease the base-line heart rate by 25 percent , or variceal ligation , to be performed weekly until the varices were obliterated or so reduced in size that it was not possible to continue treatment . RESULTS Of the 89 patients , 82 of whom had cirrhosis of the liver , 44 received propranolol and 45 underwent variceal ligation .  The mean ( + /-SD ) duration of follow-up in each group was 14+/-9 and 13+/-10 months , respectively . The mean time required to achieve an adequate reduction in the heart rate was 2.5+/-1.7 days ; the mean number of sessions needed to complete variceal ligation was 3.2+/-1.1 . After 18 months , the actuarial probability of bleeding was 43 percent in the propranolol group and 15 percent in the ligation group ( P=0.04 ) . Twelve patients in the propranolol group and four in the ligation group had bleeding . Three of the four in the ligation group had bleeding before their varices had been obliterated . Nine patients in the ligation group had recurrent varices , a mean of 3.7 months after the initial treatment . Five patients in each group died ; bleeding from the varices was the cause of death of four patients in the propranolol group and of three in the ligation group . There were no serious complications of variceal ligation ; in the propranolol group , treatment was stopped in two patients because of side effects . CONCLUSIONS In patients with high-risk esophageal varices , endoscopic ligation of the varices is safe and more effective than propranolol for the primary prevention of variceal bleeding Fifty-two patients with severe cirrhosis ( Child Class C ) and variceal hemorrhage requiring six or more units of blood were r and omly assigned to either sclerotherapy or portacaval shunt . Of 38 pretreatment characteristics , only the frequency of active alcoholism differed significantly between the groups . During the initial hospitalization , the patients in the shunt group required significantly more blood ( 21.5 + /- 3.1 units ) than did those in the sclerotherapy group ( 12.3 + /- 1.3 units ) , although the latter had significantly more rebleeding during hospitalization after the procedure ( 14 of 28 vs. 5 of 24 patients ) . There was no difference in short-term survival , with 13 patients in the sclerotherapy group discharged alive , as compared with 10 patients in the shunt group . Patients were followed for a mean of 263 days after the initial discharge ( range , 8 to 1117 ) . The sclerotherapy group required significantly more days of hospitalization for rebleeding , but we failed to demonstrate any significant difference in long-term survival between the sclerotherapy and shunt groups . Total health-care costs per patient were significantly higher for the shunt group ( + 23,957 + /- + 3,111 ) than for the sclerotherapy group ( + 15,364 + /- + 2,220 ) . We conclude that sclerotherapy is less costly than portacaval shunt and as effective for the treatment of esophageal varices associated with severe cirrhosis In a continuation of a trial for which preliminary results were reported in the Journal two years ago , a total of 6 
    Output:
    
All shunts result ed in a significantly lower rebleeding rate at the expense of a higher incidence of encephalopathy .
TIPS was complicated by a high incidence of shunt dysfunction .
No survival advantage was demonstrated with any shunt