Page 331 - Read Online

Tanos et al. Mini-invasive Surg 2020;4:39 I http://dx.doi.org/10.20517/2574-1225.2019.59 Page 3 of 15

METHODS
Materials
A literature review of internet/online databases and formal papers and presentations was performed.
Internet-based resources included the following: (1) search engines: Google and Google Scholar; (2)
research databases: PubMed and Ovid Embase; (3) library database: St. George’s University of London
Hunter Database. Numerous scientific journals both print- and web-based were accessed through these
databases. Main titles included: Fertility & Sterility, American Journal of Obstetrics & Gynecology, European
Journal of Obstetrics & Gynecology & Reproductive Biology, Reproductive BioMedicine Online, Human
Reproduction, and PlosOne.

Methods
Core search terms were: “ovarian endometrioma”, “endometrioma + surgery”, “endometrioma + surgery
+ IVF”, “endometrioma + Assisted Reproductive Therapy (ART)”. Additional search terms were: “ovarian
endometrioma + adolescent”, “ovarian endometrioma + surgery”, “ovarian endometrioma + adolescent
+ surgery” and “ovarian endometrioma + adolescent + IVF + surgery”. PubMed was used as the primary
source of literature due to highest yield of relevant material.

Initial results were further filtered by publication date within 10 years. For the “ovarian endometrioma +
adolescent” search, the filter was limited to 5 years as this is a more specific and contemporary research
area, with the aim of amassing only the most relevant and current literature. From the final 180 articles,
titles and publication dates were used to further distinguish relevant literature and isolate prospective
studies. Additional filters were applied to focus on adolescents. Figure 1 outlines the database search
process carried out.

A total of 33 articles matching our search criteria were analyzed and categorized into pro/con of
endometrioma surgery prior to IVF depending on the evidence presented.

Fourteen articles provided evidence in support of surgical removal of endometriomas prior to ART. There
were two retrospective case-control studies, two retrospective cohort studies and one retrospective analysis.
Additionally, there was one committee opinion, one scientific impact paper, one pooled analysis, one
literature review, one systematic review and two meta-analyses. Notably there were only two prospective
studies - a prospective cohort study and a prospective randomized study [Table 1].

Nineteen articles provided evidence against removal. There were seven retrospective studies and six
prospective studies. Additionally, there were two meta-analyses, two literature reviews, one systematic
review and one scientific impact paper [Table 2].

Five articles provided evidence for both pros and cons of removal of endometrioma prior to IVF, with a
combined total patient population of 6088 [8-12] . In seven studies, the research design, number of patients
and characteristics, and results extraction were not clear and thus, excluded from our calculations.

For analysis of current evidence on implantation and pregnancy rates between surgical removal of
endometrioma and no surgery prior to IVF, only four studies matched the selection criteria. The following
exclusion criteria were applied to the search: (1) sample population: women with endometrioma;
intervention group: women having surgical treatment prior to IVF; and control group: women with
unremoved endometrioma going into IVF; (2) primary outcomes: implantation rate and pregnancy rate; (3)
interventional studies (no review papers); and (4) publication date within last 10 years. An exception was
[14]
[13]
made to the fourth criteria in order to include Wong et al. and Garcia-Velasco et al. . The publication
date criteria resulted in many relevant studies being excluded. Among the four studies selected, two were
retrospective case-control studies [14,15] and the other two were retrospective cohort studies [13,16] .