Five RCTs (312 patients) and 18 non-randomised studies (2,853 patients) were included. The non-randomised studies included 11 prospective cohort studies (2,115 patients) and 5 retrospective cohort studies (738 patients).
The inter-rater agreement on the data extraction was 100%. In 4 of the 5 RCTs adequate allocation concealment was reported and the outcome assessor was blinded.
Level 1 studies (RCTs).
There was no significant difference between PBD and no PBD in the overall death rate: 15.9% with PBD versus 13.5% with no PBD. The OR was 1.90 (95% CI: 0.63, 2.23). No significant statistical heterogeneity was found (p=0.78). The pre-operative death rate was 5.1% with PBD versus 1.3% with no PBD. The post-operative death rate was 10.8% with PBD versus 13.5% with no PBD. Neither difference was statistically significant.
The overall complication rate was significantly higher with PBD than with no PBD: 57.3% with PBD versus 41.9% with no PBD. The OR was 1.99 (95% CI: 1.25, 3.16). No significant statistical heterogeneity was found (p=0.40). The drainage-related complication rate was 27.4% with PBD. These complications included perforation of the duodenal wall, bleeding and pancreatitis. The post-operative complication rate was significantly lower with PBD (29.9%) than with no PBD (41.9%). The OR was 0.59 (95% CI: 0.37, 0.94). No significant statistical heterogeneity was found (p=0.28).
The mean total length of hospital stay was significantly increased with PBD compared with no PBD: 42 days versus 24 days (p<0.01). The mean number of pre-operative days was 14.6 days with PBD. There was no significant difference in the length of post-operative hospital stay between PBD (27 days) and no PBD (24 days).
Level 2 studies.
There was no significant difference between PBD and no PBD in the overall death rate: 3.2% with PBD versus 4.9% with no PBD. The OR was 0.91 (95% CI: 0.61, 1.36). No significant statistical heterogeneity was found (p=0.25).
The overall complication rate was significantly higher with PBD (58.8%) than with no PBD (42.1%). The OR was 1.64 (95% CI: 1.20, 2.26). The studies were very heterogeneous.
The mean length of hospital stay was significantly increased with PBD compared with no PBD: 33 days versus 18 days (p<0.01).