2.2. Literature Search and Study Selection
An initial scoping search and a systematic literature search were
performed by a medical librarian to identify RCTs and observational
studies that compared concomitant Cox-Maze and PVI in patients who
underwent MV surgery. Medline,
EMBASE databases, and the Cochrane Library were searched from 1987 up to
15th of March 2022 using the following search terms:
Maze surgery, Maze procedure, Maze technique, maze or Cox-Maze vs.
pulmonary vein isolation, ablation surgery, ablation procedure, surgical
ablation. Details of the search strategy are provided in the Supplement.
We defined 12-month mortality and recurrence of AF postoperatively as
outcomes of interest. We expected that variety of outcomes illustrating
efficacy/safety would be reported, but they were not reported
consistently over the studies.
After deduplication, study eligibility was assessed independently by two
investigators. Any discrepancies were resolved by discussion between the
3 investigators. The studies were selected through the following two
levels of screening: in the first step studies were independently
screened based on titles and abstracts, and in the second step,
full-text reports were evaluated based on predefined criteria. Studies
were eligible if they compared outcomes in patients with AF undergoing
MV surgery and concomitant Cox-Maze procedure or PVI and met the
following inclusion criteria:
1. Population: adults or adolescents (12 years or older)
2. Comparator: Cox-Maze vs PVI
3. Provided outcomes: death, recurrence of AF at 12-month follow-up
4. Design: RCT or non-randomized studies of interventions (NRSI) with at
least 20 patients per treatment of interest
5. Published in English language.
Studies were ineligible if they had follow-up shorter than 12 months and
if they were duplicates. For studies reported in more than one
publication, or when institutions reported subsequent studies with
accumulating numbers of patients or increased lengths of follow-up, only
the most complete reports (in terms of reported outcomes and control of
confounding) were included.