Infected pilonidal sinus is a common suppuration that occurs twice as often in men as in women, usually between the ages of 15 and 30. Clinical diagnosis is easy, whether the presentation is acute or chronic. Exeresis with a wound left open requiring secondary postoperative healing is the most widely practiced technique in France because its recurrence rate is the lowest, but it has the disadvantage of requiring daily or even twice-daily local nursing care, long healing, and a break in activity.

In order to limit the disadvantages of the open technique, "conservative" minimally invasive techniques have also recently been developed in response to strong patient demand: such as endoscopic treatment (EPSIT = Endoscopic Pilonidal Sinus Treatment, or VAAPS = Video-Assisted Ablation of Pilonidal Sinus), or the SiLaT (Sinus Laser Therapy) laser.

More recently, radiofrequency has emerged as a new technique in the treatment of hemorrhoidal pathology according to the Rafaelo procedure as well as the Fistura procedure for anal fistulas. The principle of the treatment is similar to that of the laser, based on radio frequency thermocoagulation using very high frequency electromagnetic waves (4MHz), similar to the principle of microwaves. However, its use in the infected pilonidal sinus has not yet been described. The fibers used in anal fistulas are perfectly adapted to the treatment of the pilonidal sinus. In addition, and in contrast to the laser, several fiber diameters are available depending on the size of the fistula path(s). For example, the large diameters of 9 Fr seem to be more adapted to the deep and wide cavities of the pilonidal sinuses than those of the SiLaT, which has a single fiber diameter. The investigators can therefore think that this type of fibers could allow a more efficient destruction of the granulation tissues and a better docking of the cavity walls.

According to published studies in the treatment of anal fistulas, the safety profile of this treatment is perfectly reassuring since the penetrance of the energy released does not exceed 3 mm in depth.

The aim of this study is to propose a competing alternative to the SiLaT laser, which is radiofrequency according to the Fistura® procedure, by evaluating its safety, efficacy and patient satisfaction on a series of consecutive patients treated

Inclusion Criteria:

• patient presenting an infected pilonidal sinus requiring an surgical procedure, at the exception of acute abscess stage
• Patient aged 18 or above
• For Women Of Child Bearing Age, use of efficient contraceptive (less than 1% failure)
• Patient with health insurance coverage
• French-speaking patient
• Signed written informed consent

Exclusion Criteria:

• Patient already included in a type 1 interventional research protocol (RIPH1)
• Patient with cardiac disease (including pacemaker)
• Patient with skin infection
• Patient for whom local or general anesthesia is contraindicated
• patient presenting an anal infectious disease, or an anal fissure or who have previously had a stapled hemorrhoidopexy (Longo procedure) with metallic staples.
• Patient using anticoagulant or anti-platelet agent (at the exception of aspirin)
• Patient suffering from innate hemostasis and/or coagulation disorder
• Patient for whom MRI is contraindicated
• Pregnant or Breastfeeding women
• Patient under guardianship or curatorship
• Patient incarcerated
• Patient under legal protection
• Patient refusing follow-up