Endoscopic Carpal Tunnel Release

First introduced in 1989 by Okutsu et al , endoscopic carpal tunnel release has undergone close scrutiny and evolved from a two port method with poorer outcomes to a safe technique through the one portal Agee protocol. It remains a safe option in the hands of an experienced surgeon. Because fewer volar structures are divided, it was hypothesized that this would avoid many of the more common complications of open release technique including pronounced scars and pillar pain with associated loss of grip strength.
Patients who are candidates for endoscopic carpal tunnel release are consented and taken to the OR usually under sedation. The patient is marked, including all relevant anatomic landmarks. Incision is made between FCU and just ulnar to palmaris longus just proximal to the distal wrist crease taking care to not cut or injury the radially located palmar cutaneous branch of the median nerve. If it is visualized it should be retracted radially.
Tenotomies are used to spread through the subcutaneous tissue and down to the antebrachial fascia. Skin hooks are used to retract the skin edges, and the superficial fascia is further sharply divided, thus exposing the transverse forearm fascia. An #11 blade scalpel is used to cut a distally based window through the forearm fascia. The synovium elevator is inserted through this window along deep side of the forearm fascia in line with the base of the ring finger, radial to the hook of the hamate and advanced distally. The elevator is kept along the deep surface which allows for a feeling of roughness (“washboard effect”) as it runs over the transverse carpal ligament. This is necessary to clear off any synovium or carpal tunnel contents from the underside of the transverse carpal ligament. The hamate hook finder can be advanced on the ulnar side of the tunnel hugging the hook of the hamate until this hook is felt distally through the subcutaneous tissue.
Then the blade assembly of the endoscope is introduced into the carpal tunnel. The surgeon’s non-device hand can be used to hold and adjust the wrist, bringing the transverse carpal ligament into view through the scope. Ensure as the scope passes to define the distal end of the transverse carpal ligament and the location of the fat pad.
Elevate the blade to engage the distal ligament margin and withdraw firmly while hugging the hook of the hamate. Ensure the distal edge is completely released before continuing proximally. Once this is confirmed, engage the proximal ligament and lift the blade into the apex of the V and withdraw to complete the release. The release is complete when the edges of the ligament retract completely ulnarly and radially.

The Agee one portal endoscopic carpal tunnel release is indicated in patients diagnosed with carpal tunnel syndrome not associated or secondary to any known pathology.

This procedure should not be used in patients with known wrist deformities that would affect the carpal tunnel anatomy such as the distal radius fracture, rheumatoid arthritis or congenital anatomical abnormalities especially involving the hook of the hamate. Additionally, it is relatively contraindicated in those with especially small hands and/or large forearms or particularly tight carpal tunnels.

Endoscopic Carpal Tunnel Release System With Smart Release Disposable Blade Assembly
Synovium Elevator

The patient should be placed in a supine position with the affected hand outstretched on a hand table. A tourniquet should be placed above the antecubitum. The video tower for the endoscope should be placed distal to the affected hand at the end of the hand table, easily viewed over the assistance’s shoulder. The surgeon should be positioned in order to allow the surgeon’s dominant hand to align the blade assembly so that it points from the ulnar side of the carpal tunnel to the base of the ring finger to avoid injury to the median nerve. For surgeons who are right handed, most will position themselves in the axilla for a right carpal tunnel release and a cephalic position for a left sided release. The hand should be palmar side up on the table and draped sterilely from the antecubitum distally.

N/A

Prior to incision and inflation of the tourniquet, anatomic landmarks should be marked. These include flexor carpi ulnaris, palmaris longus, hook of hamate and pisiform. A distal wrist crease should be chosen and marked as the single port incision line. If two volar wrist creases are present distally, the more proximal one should be chosen as it makes the procedure more technically easy.

Once the tunnel for the endoscope is made, insertion of the endoscope must follow an ulnarly directed path. The scope should hug the deep side of the transvers carpal ligament and be aimed towards the ring finger, while hugging the hook of the hamate in order to avoid any injury to the median nerve.

Intraoperative: injury to median nerve and/or palmar cutaneous branch of median nerve, incomplete release of transverse carpal ligament.
Early post operatively: Hypersensitivity and pain at scar, residual hand pain
Post operatively: recurrence or persistent of symptoms, reflex sympathetic dystrophy at scar site.

Intraoperative: injury to median nerve and/or palmar cutaneous branch of median nerve, incomplete release of transverse carpal ligament.
Early post operatively: Hypersensitivity and pain at scar, residual hand pain
Post operatively: recurrence or persistent of symptoms, reflex sympathetic dystrophy at scar site.

Okutsu I, Ninomiya S, Takatori Y, Ugawa Y. Endoscopic Management of Carpal Tunnel Syndrome Arthroscopy: The Journal of Arthroscopic and Related Surgery 1989; 5(1):11-18.
Chow J. The Chow technique of endoscopic release of the carpal ligament for carpal tunnel syndrome: four years of clinical results. Arthroscopy 1993; 3: 301-13.
Agee JM, McCarroll HR, Tortosa RD, Berry DA, Szabo RM, Peimer CA. Endoscopic Release of the Carpal Tunnel: A Randomized Prospective Multicenter Study. 1992; J Hand Surg 17A:987-95.
Palmer et al Endoscopic Carpal Tunnel Release: A Comparison of Two Techniques with Open Release Arthroscopy: The Journal of Arthroscopic and Related Surgery 1993: 9(5): 498-508.
Beck JD. Deegan JH, Rhoades D, Klena JC. Results of Endoscopic Carpal Tunnel Release Relative to Surgeon Experience with the Agee Technique. 2011 J Hand Surg 36(1):61-64.