Patient exam. Examine the patient in the preoperative unit prior to surgery to confirm triggering of the affected digit and so that a comparison can be made after release is performed. It is wise to mark the incision and affected digit at this time to prevent a wrong-site or wrong-side surgery event. It is important to also check the digit dorsally to rule out a sagittal band injury with extensor tendon subluxation as a cause for triggering.

Surgical table. Virtually any surgical table that accommodates a hand-table attachment will do. To maximize efficiency, consider stretcher-based surgery using a hand-table that works in conjunction with the stretcher to avoid the need for transferring the patient to and from an operating room table.

Patient position. Supine with the operative hand on a hand-table. Rotate the table 90 degrees from anesthesia such that the operative hand is in the center of the room (under the operating room lights) opposite the anesthesia provider. When performing bilateral surgery, keep the head of the patient pointed toward anesthesia and pull the table away from anesthesia far enough to allow the surgeon and the assistant to easily sit on either side of the hand-table without becoming contaminated.

Anesthesia. Discuss an anesthesia plan with the anesthesiologist prior to surgery. Many surgeons prefer to perform trigger releases under local anesthesia with sedation. Some may elect for a sensory block to be performed by anesthesia preoperatively; though, this is often not necessary. Additionally, wide awake, local anesthesia, no tourniquet (WALANT) surgery is becoming more popular. ^{7 , 8}

Apply a tourniquet to the upper arm or forearm prior to prepping and draping. Alternatively, a sterile tourniquet can be applied after prepping and draping or a HemaClear^® tourniquet/Esmarch can be used.

Ensure that all appropriate instrumentation is available. A lead-hand or equivalent device is helpful to prevent the unaffected digits from getting in the way. A No. 15 blade scalpel will be used on the skin followed by a small beaver blade for release of the A1 pulley. Small skin hooks are helpful for early retraction followed by Ragnell or Senn retractors for deeper retraction. Self-retaining retractors such as a Heiss retractor can be particularly valuable when operating without an assistant. Stevens tenotomy scissors or small, blunt-tipped scissors will help with complete release of the pulley. A bipolar electrocautery device should be available for obtaining hemostasis. A right-angle clamp can be useful during dissection and for testing of the release. Some surgeons prefer a fine hemostat for dissection. Suction, sterile sponges, sterile saline, bulb syringes, needle drivers, Adson forceps, sutures, a hypodermic needle, and a 10cc syringe should also be available.

If local anesthesia is to be used, it should be injected in the area of the incision. A combination of bupivacaine and lidocaine is a good choice to provide relief of pain both during and after the procedure. There is no need to inject into the sheath itself.

Many surgeons will exsanguinate the arm and put up a tourniquet prior to incision and after local anesthesia has been injected.

Prior to incision, test the effectiveness of the local anesthetic by pinching the skin with an Adson forceps.

There are multiple appropriate incisions for performing trigger release of both the thumb and fingers (▶Fig. 4.1 and ▶Fig. 4.2). In general, the A1 pulley of the thumb lies just volar to the thumb metacarpophalangeal (MCP) joint. ² A two-limb, Bruner incision can be marked out with its apex pointed either ulnar or radial and centered over the thumb MCP joint. Alternatively, the incision can be made in or adjacent and parallel to the proximal volar crease where the thumb meets the thenar eminence. Since the thumb is pronated with respect to the palm, the incision should trend more ulnar toward the first webspace than might appear on first glance.

The proximal portion of the A1 pulley of the fingers is located a reliable distance proximal to the proximal digital crease at the MCP joints. This distance has been shown to be the same as the distance between the PIP crease and the proximal digital crease. ⁹ Thus, the latter distance can be measured and used to ideally locate the incision over the A1 pulley. Multiple appropriate incisions are useful for the fingers including horizontal, vertical, and oblique incisions both in and out of the palmar creases. ² We prefer an oblique incision about 30–45 degrees from horizontal unless multiple adjacent digits are being released in which case a single horizontal incision for both digits is effective.

For the thumb, the skin incision should be made particularly carefully to avoid injury to the radial neurovascular bundle, which is subcutaneous at the level of the A1 pulley and crosses the flexor pollicis longus (FPL) just proximal to the A1 pulley (▶Fig. 4.3). ^{2 , 10 – 12}

After incision of the skin, small skin hooks are used to spread the incision while the surgeon uses a bipolar to coagulate any bleeding vessels.

Next, a right-angle clamp, Stevens dissecting scissors, or a fine hemostat is used to spread the subcutaneous fat and tissues down to the flexor sheath (▶Fig. 4.4). The direction of spread should be in line with the tendon and neurovascular bundles to avoid injury. It is important to also spread proximally and distally in the wound to allow for visualization of the A1 pulley across its whole length.

The skin hooks are removed and Ragnell or Senn (blunt end) retractors are placed into the wound radially and ulnarly. The retractors are used to both expose the A1 pulley and protect the neurovascular bundles that run on either side of it. ^{2 , 10}

An additional retractor can be used both proximally and distally to improve exposure during release.