Surgical portosystemic shunts versus devascularisation procedures for prevention of variceal rebleeding due to hepatosplenic schistosomiasis
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Date
2017
Authors
Ede, Chikwendu Jeffrey
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Abstract
Background: Surgical interventions such as shunts and devascularisation procedures are effective
therapies to prevent variceal rebleeding in people with hepatosplenic schistosomiasis. As this disease is
prevalent in low income countries, the impact of eco-social factors result in poor compliance with nonsurgical
therapies that require repeated sessions and long-term follow-up.
Objectives: To determine whether surgical portosystemic shunts have better outcomes compared with
oesophagogastric devascularisation procedures in the prevention of variceal rebleeding due to
schistosomal portal hypertension (SPH).
Methodology: This meta-analysis was conducted using standards expected by The Cochrane
Collaboration. All randomised clinical trials comparing surgical portosystemic shunts with
oesophagogastric devascularisation with or without splenectomy in the prevention of variceal rebleeding
due to hepatosplenic schistosomiasis were selected. The risks of bias were assessed according to domains
and risk of random errors with Trial Sequential Analysis. The quality of evidence was assessed using the
Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) Working Group
approach.
Results: Two trials met the inclusion criteria of this review and were selected. An analysis of 115
participants, 57 who received distal splenorenal shunt (DSRS) and 58 who received devascularisation
procedure is presented. The trials were assessed at high risk of bias. There is no difference in overall
mortality between DSRS versus devascularisation, risk ratio (RR) is 1.40, (95% confidence interval (CI)
0.32 to 6.15), downgraded to very low quality due to overall risk of bias, imprecision and publication
bias. Variceal rebleeding following devascularisation is statistically significant higher than after DSRS
(RR is 0.23, 95% CI 0.05 to 1.01), very low quality evidence due to bias, imprecision, and publication
bias. The number of participants needed to treat with DSRS to achieve benefit (NNTB) is 8. Serious
adverse events reported as procedure specific include: portal vein thrombosis, haemolysis, ascites and
shunt dysfunction. There was no report on quality of life. DSRS is associated with a statistically
significant higher post procedure encephalopathy (RR 8.10, 95% CI 1.04 to 62.83), downgraded to very
low quality due to overall risk of bias, imprecision, and publication bias. Trial sequential analysis shows
no strong evidence to accept or reject the difference in variceal rebleeding and encephalopathy rate for
both interventions because of bias and inadequate sample size. Outcomes of proximal splenorenal shunt
(PSRS) compared to devascularisation were reported by a single trial, therefore no meta-analysis was
computed for this comparison, nor subgroup of PSRS compared to DSRS.
Conclusion: Available evidence seems to suggest that DSRS is better than devascularisation for the
prevention of variceal rebleeding due to hepatosplenic schistosomiasis, but this is at the cost of significant
encephalopathy. The review authors are cautious to make this conclusion because overall evidence is very
low quality and only few trials with small sample size are available. Further randomised clinical trials
with adequate sample size and good methodological quality are needed.
Description
A research report submitted to the Faculty of Health Sciences, University of the
Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of
Master of Medicine in Surgery
Johannesburg, 2017