The hanging wire technique is used to selectively bind the fistula tract with medicinal threads and rubber bands to drain or slowly cut it for the treatment of anal leakage and canker sores, etc. Especially for the treatment of high anal leakage, the damage to the sphincter muscle is small and the function of the anus is better maintained.
I. Commonly used instruments
1.Rubber band.
2.Silk thread; No. 7 or No. 10 non-absorbable surgical suture.
3.Probe; ball-tipped silver or copper probe.
4.Anal mirror.
II. Basic operation methods
(A) Drainage hanging thread technique
1.Applications
Drainage of anal fistula and perianal abscess.
2.Pre-operative preparation
Pre-operative skin preparation and enema cleaning of the lower rectum.
3.Position
Lateral or truncal position.
4.Anesthesia
Lumbar point anesthesia.
5.Surgical steps
(1) Drainage and hanging line for perianal abscess: after the abscess fluctuates obviously or drains out the pus under the guidance of ultrasound in the cavity, separate the interval in the abscess cavity with fingers, and use drainage and hanging line for the abscess that affects several interstices. The abscess cavity is explored from the incision with curved vascular forceps, and one or more incisions are made next to the anus to facilitate drainage and avoid damage to the sphincter, and rubber bands or multi-stranded silk threads are introduced to form a loop respectively to keep the drainage in a relaxed state. For abscesses with a clear internal opening, a probe can be inserted through the abscess cavity and a rubber band or silk thread introduced through the internal opening for marking or second-stage incision. After the operation, the drains are removed and wrapped with cotton pads until the abscess cavity is closed when the redness and pain have subsided and there is no obvious pus.
(2) Anal fistula drainage hanging line: determine the drainage hanging line site according to the location, number and relationship between the fistula and the sphincter. The ball probe is inserted into the fistula at the external opening, and if the external opening is temporarily occluded, a slight incision can be made, and the fistula can be passed through to the main tube, then the fistula can be scraped with a spoon to remove the carrion tissue, and then the ball probe is inserted into the tube, and the tip of the probe is connected to 10 strands of No. 7 medical silk and then introduced into the fistula tract to keep the wire loose. Multiple branches can be treated in the same way. After the operation, the wire can be removed in stages when the purulent discharge is reduced, and the wire can be removed with cotton padding until the fistula is closed.
(B) Cutting and hanging technique
1. Indications
High anal fistula, complex anal fistula.
2. Preoperative preparation, position and anesthesia
Same as the drainage hanging technique.
3.Surgical steps
①Probing of the internal opening: anal finger examination through the skin of the anal canal and palpate the fistula, near the dentate line can be palpated hard knots or depressions, often the internal opening; or use the staining method, filling the rectum of the anal canal with gauze, injecting methylene blue solution from the external opening, the filled gauze can be stained blue to determine the existence and location of the internal opening; most commonly used probe method, the left hand index finger into the anus, the right hand holding a ball probe from the external opening of the fistula probe, along the fistula walking Gently and carefully search for the internal orifice, avoiding the use of violence to avoid false internal orifices. If the probe reaches the mucous membrane of the internal orifice and cannot be directly probed out, the probe should be withdrawn slightly and probed into the adjacent saphenous fossa, if still not sure, the suspected anal sinus can be probed with a saphenous hook under the anoscope, if the depth of the anal saphenous fossa is more than 25px, it is mostly the internal orifice, and continued probing can often meet with the probe and guide the probe out of the internal orifice. For those who do not recover from multiple treatments or have complicated recurrent episodes, preoperative fistulography, endorectal ultrasound or magnetic resonance imaging should be performed to help determine the fistula pathway and the location of the internal orifice.
②Cut and hang wire: Probe the fistula from the external opening, cut the skin and subcutaneous along the fistula alignment, remove the carrion or wall of the fistula, expose its sphincter portion, and leave the hang wire in place. Connect the wire to the tip of the probe and the rubber band, so that the rubber band or wire enters from the inner port and leads out from the outer port, tighten the rubber band or wire tightly to the sphincter, and shorten it by 2-5 mm in the natural state.
For complex anal fistula or fistula bending, if there is only one internal orifice, tighten the thread at the internal orifice and main fistula, and promote fistula closure with Chinese medicine pad cotton method. For complex fistulas with multiple internal openings, the wires can be hung separately, but each tightening is limited to one place and according to the thickness of the sphincter, the superficial fistula is tightened first to minimize damage. When tightening the wire, compound lidocaine injection can be used in the muscle around the wire and at the wound edge to reduce pain.
Special tips
For high anal fistula and perianal abscess, preoperative ultrasound or magnetic resonance imaging of the rectal cavity should be performed as much as possible to clarify the scope and depth of the abscess, the fistula pathway and the location of the internal opening.
2. To protect anal function, the cutting and hanging of sphincter tissue should be minimized. The rubber band will fall off after 7 to 10 days after tightening the thread for superficial fistulas; for high fistulas, the thread should be tightened several times, 2 to 4 mm each time.
The fistula should be treated with a daily herbal fumigation bath and medication change. The wound should be observed when changing the medicine so that the wound heals gradually from the base upwards to prevent bridge healing.
Contraindications
1. Rectovaginal fistula.
2.Anal fistula malignant or due to malignant tumor.
IV. Precautions
1.For patients with high perianal abscess with unclear internal orifice, only hanging line drainage is performed, and the second stage of incision or cutting and hanging line will be performed after marking.
2.For multiple anal fistulas with multiple internal openings, they can be treated by hanging wires separately at the same time and alternating tight wires to avoid simultaneous incision, reduce damage and maintain anal function.
3, anal fistula trauma deeper need to wait for the trauma surface to reduce the tightening of the line.
4.If the internal opening is large, multiple strands of silk thread can be used for hanging and drainage, and gradually removed as the trauma shrinks until it heals.