CPT® Code 21705

1. Indications

The procedure described by CPT® Code 21705 is indicated for the treatment of specific conditions that involve compression of the brachial plexus and associated structures. The following conditions are explicitly mentioned as indications for this surgical intervention:

• Thoracic Outlet Syndrome - A condition characterized by the compression of the brachial plexus, which can lead to pain, numbness, and weakness in the arm and hand.
• Cervical Rib Syndrome - A syndrome that occurs when a supernumerary cervical rib arises from the C7 vertebra, potentially compressing the brachial plexus and causing similar symptoms as thoracic outlet syndrome.

2. Procedure

The surgical procedure associated with CPT® Code 21705 involves several critical steps to effectively address the compression of the brachial plexus. The following procedural steps are outlined:

• Step 1: Incision - The procedure begins with the surgeon making an incision above the clavicle to gain access to the surgical area. This incision is strategically placed to minimize trauma to surrounding tissues while providing adequate exposure for the subsequent steps.
• Step 2: Exposure of the Sternocleidomastoid Muscle - Once the incision is made, the surgeon carefully exposes the sternocleidomastoid muscle. This muscle is then incised to allow for better visibility and access to the underlying scalenus anticus muscle.
• Step 3: Division of the Scalenus Anticus Muscle - The scalenus anticus muscle is identified and subsequently divided. This step is crucial as it alleviates the compression on the brachial plexus caused by the muscle itself.
• Step 4: Division and Excision of Fibrous Bands - During the procedure, the surgeon also inspects for any fibrous bands that may be contributing to the compression of the brachial plexus. These bands are divided and excised to further relieve pressure on the nerves.
• Step 5: Resection of Cervical Rib (if present) - If a supernumerary cervical rib is identified during the dissection, the surgeon will continue to dissect down to the rib. If it is determined that the cervical rib is exacerbating the compression of the brachial plexus, it will be resected to provide additional relief.

3. Post-Procedure

After the completion of the procedure, patients may require specific post-operative care to ensure proper recovery. While the details of post-procedure care are not explicitly provided, it is generally expected that patients will be monitored for any complications related to the surgery. This may include managing pain, monitoring for signs of infection, and ensuring that the surgical site is healing appropriately. Patients may also be advised on rehabilitation exercises to restore function and strength in the affected arm and shoulder area. Follow-up appointments will likely be scheduled to assess recovery progress and address any concerns that may arise during the healing process.