Table 1.

Patient and study characteristics—sphincter-cutting procedures

Authors	Year	Study type	Intervention	Patients	Age (years)	Sex (M:F)	Quality of the studya
Sangwan et al. [13]	1994	R	Fistulotomy	461	42	310:151	8/16
Lentner and Wienert [14]	1996	R	Long-term indwelling seton	108	NR	NR	6/16
Hongo et al. [15]	1997	R	Coring out	319	NR	NR	4/16
Ho et al. [16]	1998	RCT	Fistulotomy	52	41.1	49:3	3/5
			Fistulotomy with marsupialization	51	41.2	41:10
Ho et al. [17]	2001	RCT	Chemical ayurvedic seton	46	42	21:2	3/5
			Fistulotomy	54	37	5:1
Isbister and Al Sanea [18]	2001	R	Cutting Seton	31	42	14.5:1	12/16
Shahbaz et al. [19]	2002	RCT	Fistulectomy	25	32.1	24:1	1/5
			Fistulectomy with primary closure	25
Lindsey et al. [20]	2002	RCT	Fistulotomy	7	NA	NA	3/5
Chang and Lin [21]	2003	P	Fistulotomy	45	54.2	29:16	14/16
Gupta [22]	2004	P	Radiofrequency fistulotomy	232	NR	NR	11/16
Hammond et al. [23]	2006	P	Snug seton	18	42*	26:3	13/16
Van Der Hagen et al. [24]	2006	P	Fistulotomy	62	40*	22:9	11/16
Mahajan et al. [25]	2007	P	Fistulectomy and skin graft	25	NR	24:1	3/16
Van Koperen et al. [26]	2008	R	Fistulotomy	109	39	71:38	14/16
Jordàn et al. [27]	2009	R	Fistulotomy, fistulectomy	76	NA	NA	12/16
Bokhari and Lindsey [28]	2010	R	Fistulotomy	57	NA	NA	17/24
Bhatti et al. [29]	2011	P	Fistulotomy	25	NR	46:4	15/24
			Fistulectomy	25	NR
Sahakitrungruang et al. [30]	2011	RCT	Fistulotomy	25	43.2	23:2	3/5
			Fistulotomy with marsupialization	25	40.6	4:1
Nazeer et al. [31]	2012	RCT	Fistulectomy	75	NR	NR	3/5
			Fistulotomy	75	NR	NR
Jain et al. [32]	2012	RCT	Fistulectomy	20	34.5	4:1	3/5
			Fistulotomy with marsupialization	20	34.3	9:1
Salem [33]	2012	R	Fistulectomy	146	NR	190:82	14/24
			Fistulotomy	126	NR
Kamal [34]	2012	RCT	Fistulotomy	32	NR	15:4	1/5
			Fistulectomy	44	NR
Wang et al. [35]	2012	RCT	SDPC suture dragging and pad compression	6	NA	NA	3/5
			Fistulotomy	5	NA	NA
Chalya and Mabula [36]	2013	RCT	Fistulectomy	82	37.8	76:6	3/5
			Fistulotomy with marsupialization	80	38.6	74:6
Gottgens et al. [8]	2015	R	Fistulotomy	537	45.5	379:158	12/16
Sheikh et al. [37]	2015	RCT	Fistulotomy	131	32.5	All M	1/5
			Fistulectomy	131	33.5	All M
Visscher et al. [2]	2015	R	Fistulotomy	68	NA	NA	13/16
Abramowitz et al. [38]	2016	P	Fistulotomy	133	48	107:133	14/16
Elsebai et al. [39]	2016	P	Fistulectomy	15	35.3	23:7	21/24
			Fistulotomy	15	37.4
Limongelli et al. [40]	2016	P	Fistulotomy	29	41	40:13	20/24
			Fistulotomy with marsupialization	44
Saber [41]	2016	RCT	Fistulotomy	100	NR	All M	3/5
			Fistulectomy	100	NR	All M
Vyas et al. [42]	2016	P	Fistulotomy	38	45.2	7.3:1	17/24
			Fistulectomy	37
Wang and Rosen [43]	2016	R	Fistulotomy	26	46.4	23:3	13/16
Jayarajah et al. [44]	2017	P	Multiple techniques	34	42.5	30:14	16/16
Murtaza et al. [45]	2017	R	Fistulotomy	96	40.5	81:15	21/24
			Fistulectomy	96	41.4	92:4
Ganesan et al. [46]	2017	RCT	Fistulotomy	30	NR	NR	3/5
			Fistulectomy	30	NR	NR
Shahid et al. [47]	2017	RCT	Fistulectomy	30	35.8	4:1	3/5
			Fistulectomy and suture	30	38.4	13:1
Vyas et al. [48]	2017	P	Fistulotomy	92	38.5	85:7	8/16
Mittal et al. [49]	2018	RCT	Fistulotomy	38	41.5	31:6	3/5
			Fistulectomy	37	45.2	35:3
Gupta et al. [50]	2018	RCT	Fistulectomy	30	35.5	28:2	1/5
Mallik et al [51]	2018	P	Fistulotomy	25	39.6	23:2	13/24
			Fistulectomy	25		24:1
Anan et al. [52]	2019	RCT	Fistulotomy	30	38.3	4:1	5/5
			Fistulotomy with marsupialization	30	43.5	13:2
Bhatia [53]	2019	P	Fistulectomy	50	NR	> 2:1	12/16
Sahai et al. [54]	2019	RCT	Fistulotomy	28	41	5:1	1/5
Sanad et al. [55]	2019	RCT	Fistulotomy + phenytoin 2% and sitz baths	30	41.4	5:1	5/5
			Fistulotomy + sitz baths	30
Basa and Prakash [56]	2020	P	Open Fistulectomy	25	NR	2:1	21/24
			Fistulectomy with primary closure	25	NR
De Hous et al. [57]	2020	R	Fistulectomy and suture	24	52.8	2:1	14/16
Total				4883

P prospective study, R retrospective study, RCT randomized clinical trial, NR not reported, NA not available

*Values are median

^aRandomized studies assessed according to JADAD scale [11] (maximum score: 5); non-randomized studies assessed according to MINOR Scale [12] (maximum score 16 for non-comparative studies. 24 for comparative studies)