Infiltration Technique for the Fourth FDS Opponensplasty Under WALANT: Case series.

Wide-awake Local Anesthesia No Tourniquet (WALANT) is a surgical technique that relies on anesthetic and hemostatic agents to provide conditions suitable for hand surgery without sedation and a tourniquet. The opponensplasty using the fourth flexor digitorum superficialis tendon transfer with the pisiform pulley is one of the most used in severe carpal tunnel syndrome patient who is unable to perform thumb opposition due to thenar muscle atrophy with the benefit of small incision, less soft tissue dissection, easy to perform, good esthetic result and has minor morbidity. Key advantages of the pisiform pulley provide balancing abduction and flexion strength of the thumb. To date, there is no report using the WALANT technique for the fourth flexor digitorum superficialis opponensplasty with pisiform pulley.

Between January 2019 and January 2022, 18 patients (4 males and 14 females) with severe carpal tunnel syndrome with thenar muscle atrophy underwent fourth flexor digitorum superficialis opponensplasty as day surgery under the WALANT technique. Operative data, visual analog scale (VAS) pain scores, and complications were recorded. All patients underwent the procedure without any complications.

The average age of the patients was 58.4 (43 to 62) year-old. The average operative time was 38.4 (17 to 47) minutes. The average VAS score during the anesthetic injection was 6.43 (4 to -8). The average VAS pain score during the operation was 2.1 (1 to 3). The mean intraoperative blood loss was 3 (2.6 to 6.2) mL.

The WALANT technique is safe and can be used as alternative anesthesia for the fourth flexor digitorum superficialis opponensplasty with pisiform pulley. This technique overcomes the problem of judging the appropriate amount of transfer tension by observing awake patients actively

Keywords: WALANT, Opponensplasty, Flexor Digitorum Superficialis Tendon Transfer, Severe Carpal Tunnel Syndrome