3.1. Search results and study characteristics
The systematic literature review from 1981 to 2019 provided the
following results: 581 reports and, after duplicates removal, 261 were
screened. After screening of titles and abstract, 92 papers were
excluded. The full texts of the remaining 169 articles were evaluated,
and 137 studies were excluded with reasons. A total of 32 articles
(observational studies and case series, no randomized controlled trial),
including 1191 patients, were enrolled [29-60]. A PRISMA flow
diagram of the study selection process can be found in Figure 1. The
quality assessment of the included studies is reported in Supplementary
Tables 2-5. Pooled patient data are presented in Table 1. All studies,
patients’ characteristics, main surgical strategies and early outcome
results were summarized in Table 2.