The treatment of complex anal fistula is a challenge, because inappropriate surgery may cause fecal incontinence. Video-assisted anal fistula treatment (VAAFT) and fistula tract laser closure (FiLaC™) are both minimally invasive and sphincter-saving techniques for treating anal fistula. VAAFT can treat fistula tracts under direct vision and FiLaC™ can achieve circular closure of fistula tracts. VAAFT plus FiLaC™ combines the advantages of two technologies and is a promising procedure for complex anal fistula (Figs. 1, 2, 3, 4, 5, 6).

Fig. 1
figure 1

Preoperative perianal magnetic resonance imaging shows the long fistula tract (white arrow) located near the prostate and under the levator ani muscle

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Fig. 2
figure 2

Identification of the fistula tract during the operation. The patient was placed in a lithotomy position under subarachnoid anesthesia. There was a scar and an external opening at 2 cm from the anal verge (white arrow). Exploration with the probe revealed that the fistula tract was about 10 cm long

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Fig. 3
figure 3

Placing laser fibre into the fistuloscope. We replaced unipolar the electrode of VAAFT (Karl Storz GmbH, Tuttlingen, Germany), with the radial laser probe of FiLaC™ (Biolitec Biomedical Technology GmbH, Jena, Germany)

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Fig. 4
figure 4

Direct vision was provided by the fistuloscope while the radial laser probe (14 W power at wavelength of 1470 nm) was shrinking and sealing the tract (White arrow: radial laser probe). a BEFORE laser closure. b The fistula tract had obviously shrunk after laser closure

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Fig. 5
figure 5

Wound healing 2 months after the operation

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Fig. 6
figure 6

Perianal magnetic resonance imaging (MRI) 4 months after the operation. The long fistula tract was disappeared. The perianal MRI shows excellent healing

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