Edited by: Gaetano Gallo, University of Catanzaro, Italy
Reviewed by: Ugo Grossi, University of Padua, Italy; Roberta Tutino, Treviso Regional Hospital, Italy; Steffen Seyfried, Heidelberg University, Germany
This article was submitted to Visceral Surgery, a section of the journal Frontiers in Surgery
†These authors share first authorship
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There are many surgical methods of sphincter preservation in treating complex anal fistula, but the therapeutic effects of each operation are different. Therefore, this study aimed to compare the impact of other treatment methods through a network meta-analysis to evaluate the best sphincter preservation method for treating complex anal fistula.
We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP Journal Database, and the Wanfang Database to collate randomized controlled trials on sphincter-preserving surgery for complex anal fistula.
A total of 29 articles were included in this meta-analysis. The cure rates showed no statistically significant differences between any two interventions (
According to the existing literature data, for patients with complex anal fistula, TROPIS may be the surgical method with the highest cure rate, SCT may be the treatment method with the lowest recurrence rate, and imLIFT may be the surgical method with the lowest incidence of postoperative complications.
PROSPERO, identifier: CRD42020221907.
A complex anal fistula is a refractory disease in colorectal anal surgery. According to statistics, the incidence of anal fistula is approximately 3.6%. Anal fistula mainly affects young adults with a male predominance (
Surgery is the primary treatment method for complex anal fistula, with the main aim being to preserve anal sphincter function and eliminate the fistula. Traditional surgery requires an incision of healthy tissue and has certain shortcomings, including large drainage wounds, severe pain, slow healing, and varying degrees of damage to the anal sphincter (
It is crucial to preserve sphincter function in patients with complex anal fistula, and because traditional surgical methods easily injure the sphincter, a variety of surgical treatment modalities have been developed to preserve anal sphincter function, such as sphincter-preserving thread drawing (SPTD) (
This network meta-analysis was registered in PROSPERO (Registration number: CRD42020221907), an international register website of systematic reviews (
We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP Journal Database, and the Wanfang Database to collate randomized controlled trials on sphincter-preserving surgery for complex anal fistula from database establishment to July 31st, 2021. The languages were limited to Chinese and English. Search terms included “Stem Cell Transplantation”, “Sphincter preserving thread drawing”, “Biological patch”, “video-assisted anal fistula”, “Ligation of anal fistula”, “endoscopic needle-knife incision”, “anal fistula plug”, “Pushing mucosa”, “advancement flap”, “Transanal opening of intersphincteric space”, “Rectal Fistula”, “Anal Fistula” and “Complex”. Medical Subject Headings, free-text terms, and variants were used, including aliases for each surgery. Boolean Operators (AND, OR, and NOT) were used to connect the search terms to form search expressions.
The inclusion criteria were as follows: (1) inclusion of patients with a definite diagnosis of complex anal fistula; (2) studies including interventions with various types of sphincter-preserving surgery; (3) study outcome indicators of cure rate, recurrence rate, and complication rate; (4) randomized controlled trials; (5) studies with complete data.
The exclusion criteria were as follows: (1) incomplete statistical analysis of results or insufficient data; (2) repeated published literature; (3) case report; (4) studies not examining sphincter-preserving treatment of complex anal fistula; (5) conferences, meta-analyses, and review articles.
Two investigators initially screened the retrieved studies independently according to the inclusion and exclusion criteria and then cross-checked. Controversial studies were evaluated by a third party and unified by discussion. Two investigators extracted relevant information from the included studies, including first author, publication year, publication country, sample size, age, sex, cure rate, recurrence rate, and complication rate.
Healing was defined as the absence of suppuration of the external orifice, and complete re-epithelialization was achieved after the end of follow-up. Recurrence occurred through the original tract and remained trans-sphincteric and was proven by clinical examination and ultrasound scanning. Complications refer to the occurrence of another disease or symptom during the treatment, and the latter is the complication of the former, which is not clearly defined in each literature.
Because the included studies were randomized controlled or cohort studies, the literature quality of randomized controlled trials was evaluated using the Jadad scale. The scores (0~3) were classified as low-quality literature and (4~7) as high-quality literature. The quality assessment of the included articles was performed using the Newcastle-Ottawa (NOS) scale, a quality evaluation tool specifically for case-control studies and cohort studies. The evaluation included three aspects: selection (four items), comparability (one item), and outcome (three items). Among them, the maximum score of each item of choice and outcome was 1, the total score of comparable items was 2, and the total score of scale evaluation results was 9. Scores (0–4) were classified as low-quality articles and (5~9) as high-quality.
Stata 16.0 software was used to analyze the data. Count data (binary data in this paper) are expressed by relative risk (RR), and the interval estimation used the 95% confidence interval (CI) as an indicator of affect quantity. Heterogeneity in the results was assessed using the Cochrane Q test (α = 0.1) combined with I2. If heterogeneity was acceptable, the fixed-effects model was used. Otherwise, the random-effects model was used. When the 95% CI did not contain “1,” the results were deemed statistically significant. If the 95% CI included “1,” this indicated no statistical significance. An overall inconsistency test was conducted when data were entered into Stata 16.0. If
A total of 880 relevant original articles were found in this reticular meta-analysis, including 460 English articles and 420 Chinese articles, involving 15 interventions. By carefully reading the titles and abstracts and screening the articles by inclusion and exclusion criteria, 52 articles were obtained and re-excluded by reading the complete text, and finally, 29 (
Literature screening flow chart.
The 29 included articles, with 3,608 patients, included 23 randomized controlled trial studies and six cohort studies. Only two pieces of literature in the randomized controlled trial study had low quality, and the rest had a Jadad score ≥ of 4 points. None of the cohort studies had a NOS score ≥5. Therefore, the overall quality of the included studies was good. The basic characteristics of the included studies are shown in
Basic characteristics and quality evaluation of the included studies.
Garcia-Arranz et al. ( |
2020 | Spain | RCT | 50.10 ± 10.7 | 16/7 | 23 | SCTFG | ➀➁ | 6 |
50.86 ± 9.64 | 14/7 | 21 | FG | ||||||
Garcia-Olmo et al. ( |
2009 | Spain | RCT | 42.64 ± 10.93 | 10/14 | 24 | SCTFG | ➀➂ | 5 |
43.99 ± 8.97 | 14/11 | 25 | FG | ||||||
García-Olmo et al. ( |
2015 | Spain | RCT | 42.64 ± 10.93 | 10/14 | 24 | SCT | ➁ | 7 |
43.99 ± 8.97 | 14/11 | 25 | FG | ||||||
Panés et al. ( |
2016 | Spain | RCT | 39·0 ± 13.1 | 60/47 | 107 | SCT | ➀➂ | 6 |
37·6 ± 13.1 | 56/49 | 105 | SOC | ||||||
Tsang et al. ( |
2020 | China | RCT | 47.2 ± 11.1 | 38/10 | 48 | LIFT | ➀➂ | 6 |
47.2 ± 11.1 | 9/1 | 10 | BioLIFT | ||||||
Liu H et al. ( |
2020 | China | RCT | NA | 54/10 | 64 | LIFT | ➀➁➂ | 6 |
NA | 52/12 | 64 | SPTD | ||||||
Kun Gao et al. ( |
2018 | China | RCT | 44.19 ± 5.13 | 32/9 | 41 | AF | ➀➁➂ | 4 |
43.21 ± 5.08 | 44/13 | 57 | LIFT | ||||||
Junyi Jia et al. ( |
2017 | China | RCT | 46.51 ± 6.39 | 24/20 | 44 | LIFT | ➀➂ | 5 |
46.82 ± 6.70 | 21/23 | 44 | SPTD | ||||||
Tong Jia et al. ( |
2019 | China | RCT | 36.59 ± 9.28 | 32/9 | 41 | AFS | ➀➁ | 5 |
37.98 ± 11.38 | 35/14 | 49 | SPTD | ||||||
Linyuan Lu et al. ( |
2019 | China | RCT | 42.33 ± 2.76 | 34/8 | 42 | VAAFT | ➀➂ | 5 |
42.29 ± 2.69 | 30/8 | 38 | SPTD | ||||||
Jian Peng et al. ( |
2014 | China | RCT | 35.4 ± 8.7 | 25/15 | 40 | LIFT | ➀➁➂ | 6 |
34.2 ± 8.5 | 23/17 | 40 | SPTD | ||||||
Jinglin Wang et al. ( |
2018 | China | RCT | 38.94 ± 15.71 | 23/17 | 40 | VAAFT | ➀➂ | 3 |
40.12 ± 16.33 | 21/19 | 40 | SPTD | ||||||
Hongming Xu et al. ( |
2020 | China | RCT | 38.41 ± 9.58 | 35/12 | 47 | imLIFT | ➀➂ | 4 |
38.07 ± 9.53 | 32/15 | 47 | LIFT | ||||||
Changmou Yang et al. ( |
2007 | China | RCT | 38.7 ± 12.7 | 28/14 | 42 | SPTD | ➀➁➂ | 6 |
41.9 ± 14.5 | 25/17 | 42 | Fistulectomy | ||||||
Ming Ye et al. ( |
2014 | China | RCT | NA | NA | 37 | SPTD | ➀➁➂ | 3 |
NA | NA | 37 | Fistulectomy | ||||||
Hexue Yuan et al. ( |
2019 | China | RCT | 44.3 ± 6.6 | 31/19 | 50 | LIFT | ➀➁➂ | 6 |
46.4 ± 7.2 | 28/22 | 50 | AF | ||||||
Le Zhao et al. ( |
2017 | China | RCT | 39 (22–52) | 33/10 | 43 | SPTD | ➀➁ | 4 |
42 (24–60) | 35/12 | 47 | IDBSS | ||||||
Li Zheng et al. ( |
2018 | China | RCT | 37.4 ± 13.5 | 33/9 | 42 | VAAFT | ➁ | 4 |
42.1 ± 15.6 | 32/13 | 45 | SPTD | ||||||
Junfeng Zhuang et al. ( |
2020 | China | RCT | 40.7 ± 5.2 | 25/32 | 57 | ISDPS | ➀ | 5 |
40.2 ± 5.3 | 26/31 | 57 | LIFT | ||||||
Yee Chen Lau et al. ( |
2019 | Australia | RCT | 38 (19–75) | 68/37 | 105 | LIFT | ➀ | 6 |
41 (26–69) | 7/4 | 11 | BioLIFT | ||||||
Chrispen Mushaya et al. ( |
2012 | Australia | RCT | 48.2 (20.6–72.9) | 10/4 | 14 | AF | ➀➁➂ | 6 |
47.5 (25.0–70.1) | 17/8 | 25 | LIFT | ||||||
M. D. Herreros et al. ( |
2012 | Spain | RCT | 49.78 ± 11.39 | 47/17 | 64 | SCT | ➀➁ | 6 |
47.27 ± 12.27 | 36/24 | 60 | SCTFG | ||||||
50.85 ± 12.51 | 44/15 | 59 | FG | ||||||
Wiley Chung et al. ( |
2009 | Canada | Cohort study | 46 (23~68) | 18/9 | 27 | FP | ➀➁➂ | 5 |
49 (22–68) | 22/1 | 23 | FG | ||||||
46 (21–82) | 70/16 | 86 | SD | ||||||
46 (28–75) | 71/25 | 96 | FA | ||||||
Oliver Maximilian Fisher et al. ( |
2015 | Switzerland | Cohort study | 41 (34–51) | 17/14 | 31 | AFS | ➁➂ | 6 |
44 (34–58) | 29/11 | 40 | AF | ||||||
A. Mujukian et al. ( |
2020 | USA | Cohort study | 35 (12–63) | 16/22 | 38 | LIFT | ➀➁➂ | 6 |
43 (22–68) | 10/12 | 22 | AFS | ||||||
M. La Torre et al. ( |
2020 | Italy | Cohort study | NA | NA | 26 | LIFT | ➀➁ | 5 |
NA | NA | 28 | VAFFT | ||||||
Ian Lindsey et al. ( |
2002 | Australia | RCT | NA | NA | 13 | FG | ➀➁➂ | 4 |
NA | NA | 16 | LIFT | ||||||
Pankaj Garg et al. ( |
2017 | India | Cohort study | 37.5 ± 10.7 | 510/101 | 611 | Fistulectomy | ➀➂ | 7 |
40.5 ± 11.1 | 372/36 | 408 | TROPIS | ||||||
49.0 ± 10.9 | 52/4 | 56 | AFS | ||||||
Zhiyun Zhang et al. ( |
2020 | China | Cohort study | 41.88 ± 13.38 | 18/7 | 25 | Fistulectomy | ➀➁➂ | 5 |
41.12 ± 16.61 | 17/8 | 25 | TROPIS |
In the reticulated evidence diagram, each vertex represents different intervention methods, the size of the vertex represents the sample size included in each intervention method, the line between vertices represents the direct comparison existing between two intervention methods, and the thickness of the line is directly proportional to the number of related studies. There was direct or indirect evidence between the different intervention methods, with the basic conditions for reticular meta-analysis (
Reticulated evidence diagram of different sphincter-preserving surgeries.
Twenty-six studies reported the cure rate of anal fistula. There was a closed ring between the interventions. There were direct and indirect comparisons between the interventions, and the results of the consistency test showed
Network meta-analysis results of cure rate (RR, 95% CI).
AF | ||||||||||||||
1.58 (0.90, 2.78) | AFS | |||||||||||||
1.24 (0.58, 2.68) | 0.79 (0.34, 1.79) | BioLIFT | ||||||||||||
1.24 (0.56, 2.72) | 0.78 (0.34, 1.79) | 0.99 (0.35, 2.81) | FG | |||||||||||
0.91 (0.46, 1.81) | 0.58 (0.31, 1.08) | 0.73 (0.30, 1.79) | 0.74 (0.29, 1.87) | Fistulectomy | ||||||||||
1.04 (0.42, 2.59) | 0.66 (0.27, 1.61) | 0.84 (0.29, 2.42) | 0.84 (0.27, 2.60) | 1.14 (0.47, 2.77) | IDBSS | |||||||||
0.79 (0.34, 1.86) | 0.50 (0.20, 1.24) | 0.64 (0.24, 1.72) | 0.64 (0.21, 1.93) | 0.87 (0.33, 2.28) | 0.76 (0.25, 2.35) | imLIFT | ||||||||
0.97 (0.64, 1.45) | 0.61 (0.36, 1.02) | 0.78 (0.41, 1.48) | 0.78 (0.35, 1.75) | 1.06 (0.58, 1.94) | 0.93 (0.40, 2.16) | 1.22 (0.58, 2.60) | LIFT | |||||||
0.77 (0.31, 1.90) | 0.48 (0.19, 1.27) | 0.62 (0.22, 1.74) | 0.62 (0.20, 1.95) | 0.84 (0.31, 2.32) | 0.74 (0.23, 2.38) | 0.97 (0.32, 2.94) | 0.79 (0.35, 1.79) | RDIS | ||||||
1.13 (0.36, 3.56) | 0.71 (0.22, 2.31) | 0.91 (0.24, 3.44) | 0.92 (0.40, 2.10) | 1.24 (0.36, 4.32) | 1.09 (0.27, 4.42) | 1.43 (0.36, 5.69) | 1.17 (0.37, 3.72) | 1.48 (0.36, 6.05) | SCT | |||||
0.79 (0.26, 2.35) | 0.50 (0.16, 1.54) | 0.63 (0.17, 2.31) | 0.64 (0.30, 1.34) | 0.86 (0.26, 2.84) | 0.76 (0.19, 2.95) | 0.99 (0.26, 3.80) | 0.81 (0.27, 2.47) | 1.02 (0.26, 4.05) | 0.69 (0.23, 2.11) | SCTFG | ||||
1.64 (0.40, 6.62) | 1.03 (0.25, 4.28) | 1.32 (0.28, 6.22) | 1.32 (0.42, 4.20) | 1.79 (0.41, 7.91) | 1.57 (0.31, 7.91) | 2.07 (0.42, 10.21) | 1.69 (0.41, 6.91) | 2.13 (0.42, 10.81) | 1.44 (0.65, 3.22) | 2.08 (0.53, 8.21) | SOC | |||
1.10 (0.64, 1.87) | 0.69 (0.42, 1.14) | 0.88 (0.41, 1.89) | 0.89 (0.38, 2.08) | 1.20 (0.74, 1.96) | 1.06 (0.50, 2.22) | 1.39 (0.59, 3.25) | 1.14 (0.76, 1.69) | 1.43 (0.58, 3.53) | 0.97 (0.30, 3.18) | 1.40 (0.44, 4.38) | 0.67 (0.16, 2.81) | SPTD | ||
0.68 (0.28, 1.62) | 0.43 (0.19, 0.97) | 0.54 (0.19, 1.57) | 0.55 (0.19, 1.57) | 0.74 (0.41, 1.34) | 0.65 (0.23, 1.87) | 0.86 (0.28, 2.61) | 0.70 (0.31, 1.59) | 0.88 (0.28, 2.80) | 0.60 (0.16, 2.29) | 0.86 (0.24, 3.08) | 0.41 (0.09, 1.98) | 0.62 (0.29, 1.31) | TROPIS | |
0.86 (0.45, 1.64) | 0.54 (0.28, 1.04) | 0.69 (0.30, 1.59) | 0.70 (0.28, 1.77) | 0.94 (0.48, 1.85) | 0.83 (0.34, 2.00) | 1.09 (0.44, 2.72) | 0.89 (0.53, 1.50) | 1.12 (0.43, 2.94) | 0.76 (0.22, 2.65) | 1.10 (0.33, 3.65) | 0.53 (0.12, 2.32) | 0.78 (0.49, 1.26) | 1.27 (0.53, 3.06) | VAAFT |
The recurrence rate was reported in 18 literature. There was a closed ring between the interventions. There were direct and indirect comparisons between the interventions. The consistency test results showed
Network meta-analysis results of recurrence rate (RR, 95% CI).
AF | |||||||||||
1.07 (0.63, 1.81) | AFS | ||||||||||
0.99 (0.17, 5.83) | 0.93 (0.16, 5.51) | FG | |||||||||
0.08 (0.01, 0.85) | 0.08 (0.01, 0.80) | 0.08 (0.01, 1.33) | Fistulectomy | ||||||||
2.74 (0.10, 79.07) | 2.57 (0.09, 74.11) | 2.77 (0.07, 109.24) | 32.58 (0.75, 1412.71) | IDBSS | |||||||
1.98 (0.97, 4.03) | 1.86 (0.89, 3.86) | 2.00 (0.39, 10.16) | 23.55 (2.56, 216.52) | 0.72 (0.03, 19.53) | LIFT | ||||||
8.89 (0.30, 263.52) | 8.33 (0.28, 248.05) | 8.98 (0.50, 161.47) | 105.66 (1.96, 5698.76) | 3.24 (0.03, 347.41) | 4.49 (0.16, 123.32) | SCT | |||||
7.59 (0.52, 110.77) | 7.11 (0.48, 104.38) | 7.67 (1.03, 57.22) | 90.20 (2.99, 2719.25) | 2.77 (0.04, 182.55) | 3.83 (0.29, 50.77) | 0.85 (0.03, 28.83) | SCTFG | ||||
4.00 (0.13, 124.54) | 3.75 (0.12, 117.22) | 4.04 (0.21, 76.95) | 47.54 (0.85, 2673.63) | 1.46 (0.01, 162.00) | 2.02 (0.07, 58.34) | 0.45 (0.25, 0.80) | 0.53 (0.01, 18.66) | SOC | |||
0.84 (0.28, 2.53) | 0.79 (0.26, 2.37) | 0.85 (0.13, 5.39) | 9.96 (1.30, 76.02) | 0.31 (0.01, 7.31) | 0.42 (0.17, 1.03) | 0.09 (0.00, 2.91) | 0.11 (0.01, 1.70) | 0.21 (0.01, 6.79) | SPTD | ||
0.34 (0.01, 7.77) | 0.32 (0.01, 7.28) | 0.34 (0.01, 10.95) | 4.00 (0.48, 33.33) | 0.12 (0.00, 9.28) | 0.17 (0.01, 3.65) | 0.04 (0.00, 3.46) | 0.04 (0.00, 2.45) | 0.08 (0.00, 7.99) | 0.40 (0.02, 7.58) | TROPIS | |
2.07 (0.82, 5.21) | 1.94 (0.76, 4.95) | 2.09 (0.37, 11.81) | 24.58 (2.65, 228.34) | 0.75 (0.03, 20.52) | 1.04 (0.57, 1.91) | 0.23 (0.01, 6.75) | 0.27 (0.02, 3.87) | 0.52 (0.02, 15.76) | 2.47 (0.99, 6.16) | 6.14 (0.28, 133.17) | VAAFT |
The incidence rate of complications was reported in 18 pieces of literature. There were closed rings between the interventions. There were direct and indirect comparisons between the interventions. The consistency test results showed
Network meta-analysis results of patient complication rate (RR, 95% CI).
AF | ||||||||||
1.71 (0.61, 4.75) | AFS | |||||||||
1.10 (0.14, 8.86) | 0.64 (0.08, 4.96) | BioLIFT | ||||||||
0.45 (0.01, 14.22) | 0.26 (0.01, 8.11) | 0.41 (0.01, 16.87) | FG | |||||||
0.14 (0.03, 0.75) | 0.08 (0.02, 0.39) | 0.13 (0.01, 1.19) | 0.32 (0.01, 10.95) | Fistulectomy | ||||||
3.70 (0.71, 19.36) | 2.17 (0.44, 10.71) | 3.38 (0.39, 28.95) | 8.27 (0.25, 272.27) | 25.62 (4.29, 153.00) | imLIFT | |||||
1.75 (0.57, 5.35) | 1.03 (0.37, 2.87) | 1.60 (0.27, 9.37) | 3.92 (0.15, 103.46) | 12.14 (3.29, 44.73) | 0.47 (0.14, 1.61) | LIFT | ||||
0.72 (0.02, 27.67) | 0.42 (0.01, 15.81) | 0.65 (0.01, 32.40) | 1.60 (0.49, 5.21) | 4.96 (0.12, 203.91) | 0.19 (0.00, 7.74) | 0.41 (0.01, 13.26) | SCTFG | |||
0.61 (0.15, 2.40) | 0.36 (0.10, 1.29) | 0.56 (0.08, 4.04) | 1.36 (0.05, 40.59) | 4.21 (1.50, 11.86) | 0.16 (0.04, 0.75) | 0.35 (0.14, 0.86) | 0.85 (0.02, 30.96) | SPTD | ||
0.21 (0.03, 1.49) | 0.12 (0.02, 0.78) | 0.19 (0.02, 2.13) | 0.47 (0.01, 18.28) | 1.47 (0.51, 4.23) | 0.06 (0.01, 0.44) | 0.12 (0.02, 0.61) | 0.30 (0.01, 13.76) | 0.35 (0.08, 1.50) | TROPIS | |
2.52 (0.43, 14.79) | 1.48 (0.27, 8.10) | 2.30 (0.24, 22.47) | 5.64 (0.16, 201.31) | 17.47 (3.82, 80.02) | 0.68 (0.10, 4.50) | 1.44 (0.34, 6.06) | 3.52 (0.08, 152.09) | 4.15 (1.36, 12.65) | 11.88 (1.89, 74.52) | VAAFT |
A total of 15 interventions were included in this study. The probability of cure rate, recurrence rate, complication rate and other indicators under 15 interventions was ranked. The probability indicated that the intervention was the best treatment. The results of probability ranking of cure rate showed: TROPIS (78.6%) > RDIS (68.3%) > imLIFT (66.9%) > SCTFG (66.3%) > VAAFT (64.8%) > Fistulectomy (58.4%) > LIFT (54.7%) > AF (51.1%) > IDBSS (47.8%) > SCT (44%) > SPTD (40.7%) > BioLIFT (34.5%) > FG (34.1%) > SOC (24.7%) > AFS (15.1%), suggesting that TROPIS may be the surgical method with the highest recovery rate in patients after treatment. The results of probability ranking of recurrence rate showed: SCT (85.5%) > SCTFG (83.7%) > SOC (66.2%) > VAAFT (65.5%) > LIFT (64.5%) > IDBSS (61.9%) > AFS (39.9%) > FG (38.1%) > AF (36.5%) > SPTD (31.7%) > TROPIS (24.2%) > Fistulectomy (2.4%), suggesting that SCT may be the surgical method with the lowest recurrence rate in patients after treatment. The results of probability ranking of complication rate showed: imLIFT (88.2%) > VAAFT (78.6%) > LIFT (69.1%) > AFS (68.8%) > BioLIFT (54%) > AF (49.7%) > SCTFG (47.9%) > SPTD (35.6%) > FG (34.2%) > TROPIS (16.3%) > Fistulectomy (7.6%), suggesting that imLIFT may be the surgical method with the lowest complication rate in patients after treatment (
Ranking of probabilities for each intervention (SUCRA, %).
AF | 51.1 | 36.5 | 49.7 |
AFS | 15.1 | 39.9 | 68.8 |
BioLIFT | 34.5 | - | 54.0 |
FG | 34.1 | 38.1 | 34.2 |
Fistulectomy | 58.4 | 2.4 | 7.6 |
IDBSS | 47.8 | 61.9 | - |
imLIFT | 66.9 | - | 88.2 |
LIFT | 54.7 | 64.5 | 69.1 |
RDIS | 68.3 | - | - |
SCT | 44.0 | 85.5 | - |
SCTFG | 66.3 | 83.7 | 47.9 |
SOC | 24.7 | 66.2 | - |
SPTD | 40.7 | 31.7 | 35.6 |
TROPIS | 78.6 | 24.2 | 16.3 |
VAAFT | 64.8 | 65.5 | 78.6 |
The inconsistency test of cure rate, recurrence rate, and incidence rate of complications showed
The funnel plot of outcome measures such as cure rate, recurrence rate, and complication rate was plotted. From the funnel plot of cure rate, recurrence rate, and complication rate, most studies' scatter points were located above the funnel plot. The distribution of each issue was symmetrical, indicating that the included studies had less possibility of publication bias. At the bottom of each funnel plot, some scatter points are located at the bottom of the funnel plot, indicating that it is affected by some small sample effect (
The funnel plot of outcome measures.
An anal fistula is a chronic abnormal sinus tract formed after ulceration of perianorectal abscess. The fistula of complex anal fistula has a complicated course, high recurrence rate, and partial loss of anal function, which is still one of the difficult problems in surgical treatment. Preservation of the patient's anal sphincter function is directly related to the quality of life later. For this reason, a variety of surgical treatments with anal sphincter preservation have been used in clinical practice.
Different treatment modalities vary in postoperative cure rate, recurrence rate, and complication rate. The drainage thread-drawing method allows the fistula to be in a continuous opening with adequate drainage to avoid recurrent episodes of the fistula and accelerate the epithelialization of the wall. However, some studies (
According to studies (
Due to the differences and wide variety of measures for treating high complex anal fistula, there is no comparative analysis of the efficacy of different anal sphincter-preserving treatment measures. Therefore, this study is the first indirect comparison of different anal sphincter-preserving outcomes using network meta-analysis. In this meta-analysis, TROPIS was the treatment with the highest cure rate. As a newly used regimen in recent years, TROPIS has been confirmed to have an excellent therapeutic effect in several studies (
(1) There are few direct comparison studies among various interventions, and few closed rings are formed. The results mainly come from indirect comparison. Although the indirect comparison results have specific guidelines, the strength of evidence is weaker than direct comparison; (2) There are still few relevant studies reporting the postoperative pain level of patients with anal sphincter-preserving surgery for anal fistula. This Meta has not evaluated the tolerance of patients.
In the present study, it was found that TROPIS may be the treatment with the highest cure rate, SCT may be the treatment with the lowest recurrence rate, and imLIFT may be the surgical modality with the minor postoperative complications. Since the conclusion of this study is mainly derived from the results of the indirect comparison, it is hoped that the subsequent randomized controlled trial with rigorous protocol can be designed for further demonstration to provide better strong evidence support and guidance for the clinical treatment of patients with recurrent anal fistula.
The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.
HH: study design, data collections, and writing. YL and SX: data collections, data analysis, and writing. LJ: funding and study design. YG: study design and review. All authors contributed to the article and approved the submitted version.
This study was funded by Changshu Health and Family Planning Commission Supporting Project (Grant/Award Number: csws201703), Changshu Health Committee Project (Grant/Award Number: cswsq202007), National Natural Science Youth Fund Project (Grant/Award Number: 81904204), Jiangsu Youth Science Foundation Project (Grant/Award Number: bk20191091), and Project on Academic Talents of Affiliated Hospital of Nanjing University of Chinese Medicine (Grant/Award Number: y2021rc35).
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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