Table 1.

Characteristics and quality of the studies

Ref.	Country	Publish Year	Study Period	Approach	Scopy	Follow up	Design	Quality assessment
Bulian et al[23,27]	Germany	2013	2008-2010	V + A	Rigid instruments	1.04-3.14 yr	Prospective	Good
Solomon et al[28]	United States	2012	2009-2010	V + A	Flexible endoscope	1 mo	Prospective	Fair
Santos et al[29]	United States	2012	2009-2010	V + A	Flexible endoscope	3 mo	Prospective	Fair
Noguera et al[24]	Spain	2012	2009-2010	V + A	Flexible endoscope	13-20 mo	RCT	Good
Borchert et al[30]	Germany	2012	2007-2009	V + A	Rigid instruments	1 mo	Prospective	Good
Zornig et al[31]	Germany	2011	2007-2009	V + A	Rigid instruments	3-10 mo	Retrospective	Good
Niu et al[32]	China	2011	2009-2010	V + A	Flexible endoscope	2-11 mo	Retrospective	Good
Kilian et al[33]	Germany	2011	2008-2009	V + A	Rigid instruments	Null	Prospective	Fair
Hensel et al[34]	Germany	2011	2010-2010	V + A	Rigid instruments	3 mo	Prospective	Fair

Quality assessment was evaluated using modified Jadad Score³⁹ for the randomized controlled trials with a possible score of between 0 and 7 (highest level of quality), and “Good” was defined as a Jadad score of 4-7; and “poor” defined as a Jadad score of ≤ 3. The Newcastle Ottawa Scale was used to assess the quality of other studies. Maximum score on this scale was a total of 9. “Good” was defined as a total score of 7-9; “fair” defined as a total score of 4-6; and “poor” defined as a total score of < 4. V + A: Vaginal and abdominal; RCT: Randomized clinical trial.