Are pancreatic stents useful in preventing pancreatic fistula after pancreaticoduodenectomy?
There is no accord in studies on whether the use of stents is beneficial and, if so, whether the use of internal or external stents, with or without replacement is preferable.
The use of stents following pancreaticoduodenectomy was studied in 1018 participants from eight randomized controlled trials (RCTs).
We found no evidence that the use of stents leads to lower risk of fistula when compared with no stents. We also found no evidence of a difference between the use of internal and external stents. There was not enough evidence to determine the effects of replacement of pancreatic juice versus no replacement of pancreatic juice. Further RCTs on the use of stents after pancreaticoduodenectomy are needed.
Quality of the evidence
All eight included studies were reported as RCTs. The quality of the findings ranged from moderate to low across the different outcomes. The main limiting factor, which was the reason for a decrease in quality in some outcomes, was only one study included in internal stents versus no stents group. It is important to acknowledge the large potential impact if the average effect of one study differs in size or direction.
This systematic review has identified limited evidence on the effects of stents. We have not been able to identify convincing direct evidence of superiority of external over internal stents. We found a limited number of RCTs with small sample sizes. Further RCTs on the use of stents after pancreaticoduodenectomy are warranted.
Several studies have demonstrated that the use of pancreatic duct stents following pancreaticoduodenectomy is associated with a lower risk of pancreatic fistula. However, to date there is a lack of accord in the literature on whether the use of stents is beneficial and, if so, whether internal or external stenting, with or without replacement, is preferable. This is an update of a systematic review.
To determine the efficacy of pancreatic stents in preventing pancreatic fistula after pancreaticoduodenectomy.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science, and four major Chinese biomedical databases up to November 2015. We also searched several major trials registers.
Randomized controlled trials (RCTs) comparing the use of stents (either internal or external) versus no stents, and comparing internal stents versus external stents, replacement versus no replacement following pancreaticoduodenectomy.
Two review authors independently extracted the data. The outcomes studied were incidence of pancreatic fistula, need for reoperation, length of hospital stay, overall complications, and in-hospital mortality. We showed the results as risk ratio (RR) or mean difference (MD), with 95% confidence interval (CI). We assessed the quality of evidence using GRADE (http://www.gradeworkinggroup.org/).
We included eight studies (1018 participants). The average age of the participants ranged from 56 to 68 years. Most of the studies were conducted in single centers in Japan (four studies), China (two studies), France (one study), and the USA (one study). The risk of bias was low or unclear for most domains across the studies.
Stents versus no stents
The effect of stents on reducing pancreatic fistula in people undergoing pancreaticoduodenectomy was uncertain due to the low quality of the evidence (RR 0.67, 95% CI 0.39 to 1.14; 605 participants; 4 studies). The risk of in-hospital mortality was 3% in people who did receive stents compared with 2% (95% CI 1% to 6%) in people who had stents (RR 0.73, 0.28 to 1.94; 605 participants; 4 studies; moderate-quality evidence). The effect of stents on reoperation was uncertain due to wide confidence intervals (RR 0.67, 0.36 to 1.22; 512 participants; 3 studies; moderate-quality evidence). We found moderate-quality evidence that using stents reduces total hospital stay by just under four days (mean difference (MD) -3.68, 95% CI -6.52 to -0.84; 605 participants; 4 studies). The risk of delayed gastric emptying, wound infection, and intra-abdominal abscess was uncertain (gastric emptying: RR 0.75, 95% CI 0.24 to 2.35; moderate-quality evidence) (wound infection: RR 0.73, 95% CI 0.40 to 1.32; moderate-quality evidence) (abscess: RR 1.38, 0.49 to 3.85; low-quality evidence). Subgroup analysis by type of stent provided limited evidence that external stents lead to lower risk of fistula compared with internal stents.
External versus internal stents
The effect of external stents on the risk of pancreatic fistula, reoperation, delayed gastric emptying, and intra-abdominal abscess compared with internal stents was uncertain due to low-quality evidence (fistula: RR 1.44, 0.94 to 2.21; 362 participants; 3 studies) (reoperation: RR 2.02, 95% CI 0.38 to 10.79; 319 participants; 3 studies) (gastric emptying: RR 1.65, 0.66 to 4.09; 362 participants; 3 studies) (abscess: RR 1.91, 95% CI 0.80 to 4.58; 362 participants; 3 studies). The rate of in-hospital mortality was lower in studies comparing internal and external stents than in those comparing stents with no stents. One death occurred in the external-stent group (RR 0.33, 0.01 to 7.99; low-quality evidence). There were no cases of pancreatitis in participants who had internal stents compared with three in those who had external stents (RR 0.15, 0.01 to 2.73; low-quality evidence). The difference between internal and external stents on total hospital stay was uncertain due to the wide confidence intervals around the average effect of 1.7 days fewer with internal stents (9.18 days fewer to 5.84 days longer; 262 participants; 2 studies; low-quality evidence). The analysis of wound infection could not exclude a protective effect with either approach (RR 1.41, 0.44 to 4.48; 319 participants; 2 studies; moderate-quality evidence).
Operative replacement of pancreatic juice versus not replacing pancreatic juice
There was insufficient evidence available from a small trial to ascertain the effect of replacing pancreatic juice.