Morbidity and mortality following major liver resection in patients with perihilar cholangiocarcinoma: A systematic review and meta-analysis

Background: Morbidity and mortality following hepatectomy for perihilar cholangiocarcinoma(PHC) are known to be high. However, reported post-operative outcomes vary, with notable differences between Western and Asian series. Annual hospital volume may also affect outcomes. We aimed to determine morbidity and mortality rates after major hepatectomy in patients with PHC and assess differences in outcome in regard to geographical location (Western or Asian) and hospital volume. Methods: A systematic review was performed by searching the MEDLINE and EMBASE databases through the 20th of November 2017. Risk of bias was assessed and meta-analysis and meta-regression were performed using a random effects model. Results: A total of 51 studies were included, representing 4634 patients. Pooled 30-day and 90-day mortality were 5%(95%CI 3-6%) and 9%(95%CI 6-12%), respectively. Pooled overall morbidity and severe morbidity were 57%(95%CI 50-64%) and 40%(95%CI 34-47%), respectively. Western studies compared to Asian studies had a significant higher 30-day mortality, 90-day mortality and overall morbidity (Figure 1): 8% versus 2% (p<0.001), 12% versus 3% (p<0.001) and 63% versus 54% (p=0.048), respectively. This effect on mortality remained significant after correcting for hospital volume. Univariate meta-regression analysis showed no influence of hospital volume on mortality or morbidity, whilst when corrected for geographical location higher hospital volume was associated with higher severe morbidity (p=0.039). Conclusion: Morbidity and mortality rates after major hepatectomy for PHC are high. Western series showed a higher mortality compared to Asian series, even when corrected for hospital volume. The incomplete reporting and variation in criteria to report outcomes encountered in this systematic review, stress the need for standardized outcome reporting for PHC. Underlying causes for differences in outcomes between Asian and Western centers, such as differences in treatment strategies, should be further analyzed.