Carpal Tunnel Release With Wide Awake Local Anesthesia and No Tourniquet: With Versus Without Epinephrine

Abstract

Background: Wide awake local anesthesia and no tourniquet (WALANT) relies on epinephrine to create a relatively bloodless field. This study evaluated the effect of epinephrine on carpal tunnel release (CTR) surgical time and bleeding, including the need for use of a tourniquet or electrocautery. The hypothesis was that wide awake anesthesia without epinephrine is a viable option for CTR but increases operative time. Methods: Records of all patients who underwent CTR under wide awake anesthesia between October 2017 and September 2018 were reviewed. The injection consisted of either 10 cc of 1% lidocaine with 1:100,000 epinephrine mixed with 1 cc of sodium bicarbonate (8.4%) (WALANT group) or 10 cc of 1% lidocaine (wide awake local anesthesia, no tourniquet and no epinephrine [WALANE] group). The time between skin incision and skin closure was calculated. Tourniquet and electrocautery use as well as operative complications were documented. Results: Thirty-two patients underwent 43 CTRs; 22 CTRs were done under WALANT, and 21 CTRs were done under WALANE. The skin-skin time was 12.8 minute (6-25 minute; standard deviation [SD] = 4.7) for WALANT and 17.4 minute (9-30 minute; SD = 5.8) for WALANE. There was a significant statistical difference (36%) in skin-skin time between the 2 groups. None of the patients required electrocautery or a tourniquet. There were no operative complications. Conclusion: Operative time increased by 36% when epinephrine was not used. Epinephrine is not an absolute necessity to perform wide awake anesthesia but, at the same time, has the added value of decreasing surgical time. Level of evidence: IV

Introduction

Wide awake local anesthesia allows hand surgeries to be performed outside the main operating room and has gained popularity among hand surgeons.¹ The key advantage of wide awake anesthesia is the creation of a relatively bloodless field without the use of an arm tourniquet or sedation, thus the term wide awake local anesthesia and no tourniquet (WALANT).

WALANT relies on the infiltration of lidocaine with epinephrine in the surgical field. Many studies have demonstrated the safety and effectiveness of epinephrine use in fingers and hands.² Lidocaine with epinephrine provides a bloodless field through vasoconstriction, which eliminates the need for a tourniquet which, in turn, eliminates the need for sedation.³ Patients can actively move their fingers intraoperatively, allowing the surgeon to make adjustments and instantly demonstrate outcomes.

The purpose of this study was to evaluate the effect of epinephrine on carpal tunnel release (CTR) time and bleeding, including the need for use of a tourniquet or electrocautery. The hypothesis was that wide awake anesthesia with no epinephrine (wide awake local anesthesia, no tourniquet and no epinephrine [WALANE]) is a viable option for CTR but increases operative time.

Materials and Methods

Institutional review board approval (#1807199732) was granted for this retrospective review; patient consent was not required. The records of all patients who underwent CTR by the author under local anesthesia without a tourniquet between October 2017 and September 2018 were reviewed. Inclusion criteria were the diagnosis of carpal tunnel syndrome of 3 of more months’ duration that failed to respond to conservative measures including 6 weeks of splinting and 1 steroid injection. The exclusion criterion was other concomitant procedures on the same hand. Patient age, gender, operative side, injection time, skin incision time, skin closure time, intraoperative use of tourniquet, use of electrocautery, and surgical complications such as iatrogenic nerve injury were documented. The skin-skin time was calculated as the difference between skin incision and skin closure in minutes.

The anesthetic injections were administered before prepping and were introduced in a subcutaneous plane in the inter-thenar area along the planned incision.¹ The injection consisted of either 10 cc of 1% lidocaine with a 1:100,000 concentration of epinephrine mixed with 1 cc sodium bicarbonate (8.4%) [WALANT group] or 10 cc of 1% lidocaine [WALANE group]. The patient’s arm(s) was/were prepped in standard fashion. A mini-open carpal tunnel was performed 10-15 minutes after the injection. If a bleeder was identified and affected visualization, a retractor was used to apply local pressure just long enough to complete the release. The only definitive hemostasis performed was the skin closure itself. Patients were followed up at 2 weeks and 6 weeks postoperatively. The t-test was used to compare the means, and the Chi square test to compare categorical variables; statistical significance was set at a P value of .05.

Results

Thirty-two patients underwent 43 CTRs: 22 CTRs were done under WALANT, and 21 CTRs were done under WALANE. Age ranged between 23 and 86 years (average 54 years); 13 patients were male, and 19 were female. There was no significant statistical difference between the 2 groups regarding age, gender, or operative side.

The average skin-skin time was 12.8 minute (range = 6-25 minute; standard deviation [SD] = 4.7) in the WALANT group. In the WALANE group, average skin-skin time was 17.4 minute (range: 9-30 minute; SD = 5.8). There was a statistically significant difference between the 2 groups (4.6 minutes) which corresponds to 36% added time when epinephrine was not included in the injection. All procedures were completed without the use of a tourniquet or electrocautery. There were no intraoperative complications in either group. There were no hematomas, dehiscence, nor infections in either groups postoperatively.

Discussion

Carpal tunnel release with WALANT has become popular over the last decade.¹ Other popular WALANT procedures include trigger finger release, ganglion cyst excision, first dorsal compartment release, and soft tissue mass excision. More complex WALANT cases include flexor tendon repairs and trapeziectomy.^4-6 Advantages of WALANT include office-based setting and no need for a tourniquet. Dispensing with the tourniquet eliminates the need for sedation, monitoring, and intravenous access, all of which are required when the procedure is performed in the main operating room. Additional benefits of WALANT include efficiencies and cost savings in outpatient surgical case flow due to the absence of conscious sedation.

The basic premise of WALANT is using epinephrine to secure a bloodless surgical field through vasoconstriction without the use of an arm tourniquet. Traditionally, surgeons have been taught that local anesthesia containing epinephrine should not be injected into fingers.² This idea has since been refuted in many studies; and today, injection of lidocaine with epinephrine is widely used for digital and hand anesthesia.² Sodium bicarbonate is frequently used to buffer the injection, as lidocaine with epinephrine is 1000 times more acidic than standard lidocaine injections.⁷

Several factors may contribute to the feasibility of WALANE. The most obvious factor is the effect of the self-retaining retractor, which provides hemostasis by pressure. Most of the bleeding occurs at the edge of the incision and comes from subcutaneous tissues. Another source of bleeding comes from deeper tissues; this bleeding is controlled by the tension provided by the self-retaining retractor which can be adjusted as needed. The tumescence effect of the injection itself, which increases the local pressure in the subcutaneous tissue may also contribute to hemostasis. A fourth less obvious but potentially more important factor is surgeon comfort with and ability to handle soft tissue bleeding. Classic hand surgery training relies heavily on tourniquet use which establishes a dry field as a default. This “tourniquet culture” is unique to peripheral extremity surgery and does not exist in surgical fields that do not have the option of using tourniquet.

This study shows a significant increase in operative time (36% added time) when epinephrine was not used; all surgeries were completed successfully with no complications. For this reason, the current study demonstrates that epinephrine is not an absolute necessity to perform wide awake anesthesia. At the same time, it documents the added value of epinephrine in decreasing operative time. Based on these findings, WALANT continues to be our primary choice of anesthesia, and we reserve the use of WALANE for patients with contra-indications to using epinephrine such as a history of vaso-occlusive diseases. This practice is especially true when the surgical field is close to the digital arteries such as with trigger finger release.