WALANT surgery of the hand: state of the art

Abstract

• Wide-awake local anesthesia no tourniquet is named the WALANT technique.

• WALANT has had a major positive impact on cost, convenience, ecology, patient satisfaction, access to surgical care, and outcomes in hand surgery in the last 20 years.

• Safe and efficient application of the technique is based on two principles.

• The first principle is the tumescent injection of a large volume low concentration 0.25–1% lidocaine, with 1:100 000–1:400 000 epinephrine.

• The second principle of WALANT is that the proper injection should be almost painless, with the patient only feeling the first needle poke of a tiny 30G needle.

• This wide awake patient approach reduces pain, neuropraxia, and systemic side effects of sedation with preservation of motor control, thereby aiding balanced reconstruction in hand surgery.

Introduction

Hand surgery is usually performed under three main types of anesthesia techniques: local, regional, or general anesthesia. Each technique has advantages and disadvantages (Table 1). These factors need to be outweighed by surgeons and patients to select the most ideal combination of anesthesia for specific surgical procedures in the shared decision-making model for health care that we aim for today (1, 2, 3). This paper will focus on tumescent pure local anesthesia, with only lidocaine and epinephrine, with no tourniquet and no sedation. The acronym for this technique is WALANT (wide-awake local anesthesia no tourniquet).

Table 1.

On current literature and experience-based estimated comparative overview of the advantages and disadvantages of the different anesthesiology types versus the WALANT technique in hand surgery in a 5-point graded scale ranging from – (absent), +− (sometimes or partially), + (present), ++ (present in a more explicit way) to +++ (present in the most prominent way).

(Dis)advantages	Anesthesia
	General	Regional			Local
		IVR	Plexus	WB	DB	LA	WALANT
Systemic effects	+	+	−	−	−	−	−
Time	++	++	+	+	+	+	+
Cost	+++	++	++	+	+	+	+
Green footprint	++	++	++	+	+	+	+
Analgesia	−	+	++	+	+	+	++
Satisfaction	+	+	++	+	++	++	+++
Tourniquet	+	++	+	+	+	+	−
Bleeding risk	+	+	+	+	+	+	−
Dynamic surgery	−	−	−	+−	+	+	+

DB, digit block; WB, wrist block.

WALANT local anesthesia is based on two main principles. The first principle is the tumescent injection of a large volume low-concentration lidocaine, ranging from 0.25% to 1%,combined with 1:100 000 to 1:400 000 epinephrine. Tumescent refers to an adequate subcutaneous volume of local anesthesia that you can see it and feel elevating the skin, resembling a subcutaneous wave extending at least 2 cm beyond any area that will be dissected or surgically manipulated. The second principle of WALANT is that the proper injection of this tumescent local anesthesia should be nearly painless, with the patient experiencing only the initial needle prick of a small 30G (0.31 mm) needle (4).

WALANT is not a bloodless surgery, but the visibility is excellent when a window of 30 min is provided for epinephrine vasoconstriction to work well (5). Injecting the first three patients before operating on the first one is extremely efficient, allowing for performing three carpal tunnel operations per hour at a very comfortable pace with just one surgeon, one nurse, and one receptionist with field sterility conditions in a minor procedure room with no increase in the risk of surgical site infections (6, 7, 8).

Epinephrine eliminated the need for the tourniquet, which was a standard of care for decades in hand surgery (9). Tourniqueting is a painful technique that caused temporary neuropraxia within minutes due to tourniquet pressure and ischemia (10). As a result, surgery time was limited and required sedation. In addition, the surgeon could not adjust the reconstructed parts of the hand during the surgery because of the pain, neuropraxia, or motor blocks experienced by patients (11).

The latter half of the 20th century was dominated by the myth that epinephrine caused finger ischemia. Bunnell’s first American textbook on hand surgery in 1946 (12) initiated this trend. We now know that before 1950 procaine, rather than epinephrine, was the primary culprit for causing finger ischemia (13). Studies in the 21st century have produced ample evidence that epinephrine is safe to use in the finger (14, 15, 16). In addition, phentolamine reliably reverses epinephrine vasoconstriction in the finger, but this is seldom required (17, 18).

Advantages

The advantages of WALANT can be summarized in three main categories included in the abbreviation:

1. Wide awake: the patient has no sedation or general anesthesia. Local anesthesia is preferred for its elimination of systemic risks of sedation: nausea, vomiting, aspiration pneumonia, respiratory suppression, thromboembolism, cardiovascular effects, malignant hyperthermia, cerebral influences, etc. Pure local anesthesia also has economic benefits, time efficiency, and organizational surgical independence (19, 20, 21, 22). In ASA 3 or 4 patients with important comorbidities, WALANT makes hand surgery safe and possible when systemic sedation is considered too risky (23). Being awake and alert, the patient can gain insight into his condition and therapy, which will help in postoperative rehabilitation (24).

2. Local anesthesia: the numbness is administered only in the operative field. The upper limb remains under motor control by the wide awake patient. He can help by moving reconstructed parts actively during the surgery, when certain procedures need balanced fixation or tension of joints and tendons, such as in flexor tendon repair, boutonniere fingers, or in tendon transfers (25, 26, 27, 28). Pain control persists after surgery, diminishing the need for opioids when compared to general or regional anesthesia (29, 30, 31, 32). Local anesthesia is cheaper, greener, faster, and easier to perform, increasing economic efficiency in hospitals due to quick recovery and short stay (33, 34, 35, 36, 37). Improved access to surgical care has been well documented (38). Additionally, the patient does not need to be sober, so the technique can be used in urgent, isolated conditions or unplanned settings (39, 40). Epinephrine minimizes bleeding and facilitates operating on patients without stopping anticoagulant medications (41).

3. No tourniquet: This approach reduces pain and neuropraxia. It allows for longer surgery time if needed, increased comfort of the patient, and the opportunity for the patient to actively collaborate with the surgical procedure. Patients with lymphedema or arteriovenous shunt, in whom tourniquets need to be avoided, now have a safe alternative to allow for hand surgery. There is less rush to race through an operation. This can decrease mistakes that are haste induced and facilitates surgical resident learning with less time pressure (42).

Contraindications

Overall, the complication rate of WALANT is very low (1.7%), with minor superficial infection being the most common problem (32, 43). Absolute contraindications to WALANT pure local anesthesia are very few, as they are in dentistry (44). If true allergic anaphylaxis to lidocaine and epinephrine actually exists, it is extremely rare. If patients have very limited blood flow to the fingers in situations such as Buerger’s disease, scleroderma, severe Raynaud’s, or renal failure, finger injection of epinephrine is not advised or required (34, 44). In these situations, lidocaine can be used without epinephrine. The surgeon must be able to communicate with a patient who can understand, be open to this option, and be cooperative. Shared decision-making of surgeons and patients remains the basis of successful treatment (45). Infection surgery is no longer considered a relative contraindication (46, 47, 48).

Technique

Injection of tumescent local anesthetic should be almost painless in 2024, even when injecting large areas. The reader should read papers with videos that demonstrate important techniques to minimize the pain of injection of tumescent local anesthetic (49). (1) Buffer painful acidic local with bicarbonate. (2) Start with a 30G needle. (3) Do not blast local in quickly! Slow down! (4) Stabilize the syringe with both hands to avoid wobble pain. (5) Insert the needle perpendicular to the skin. (5) Use sensory noise such as pinching the skin into the needle. (6) Inject at least 2 mL slowly in the fat just below the dermis without moving the needle. (7) Never advance sharp needle tips anywhere that is not numb. (8) Only reinsert needles in numb skin. (9) Always inject too much volume instead of not enough volume. (10) Ask the patient to count the number of times he feels pain every time you inject so you can score yourself as an injector. (11) Always inject from proximal to distal. Most naturally, a calm, comforting conversation and touching reassuring hand pressure on the forearm during infiltration are examples of distraction and psychological support to enhance patients’ experience (4).

The operative field is marked with a 1–2 cm zone beyond the intended area of dissection (Fig. 1). Beginning with a small 27G or 30G (0.3–0.4 mm) needle, tumescent local anesthesia is performed by injecting 1% lidocaine with 1:100 000 epinephrine buffered with 10:1 8.4% sodium bicarbonate. It is usually recommended to follow the 7 mg per kg dose of lidocaine and epinephrine (50 mL in adults), even though higher doses have been shown to be safe so that no monitoring is required, such as at the dentist (49, 50). If more volume is required, simply add saline. About 0.25% lidocaine with 1:400 000 gives you a comfortable 3 h to perform most operations without the need to add longer-lasting local anesthetics (48). By using enough injection volume, the soft tissue swelling will elevate the overlying skin 2 cm beyond the marked area, which you can see and palpate while injecting.

Figure 1.

A ten-step illustration to perform the WALANT technique in hand surgery.

(1) Stop before you block.

(2) Prepare the syringe (long 30G needle, lidocaine 1% bicarbonate buffered room temperature).

(3) Mark the needle entry point proximal to the operation field (B).

(4) Introduce the needle 90° in the skin by pinch injection and inject a 0.5 mL visible bleb (A).

(5) Use both hands: one on the syringe and one to stabilize.

(6) Progress from proximal to distal.

(7) Blow before you go.

(8) Avoid large nerves by keeping 5 mm distance and awareness (ultrasound optional).

(9) Second needle prick, if needed, within the 1 cm marge of palpable tumescence.

(10) Wait 30 min before incising.

To avoid large nerve damage, it is advised to keep a minimum of 5 mm distance with the sharp needle tip (51). WALANT is not large nerve block anesthesia. It takes up to 100 min for lidocaine molecules to reach the center of large nerves in non-ultrasound-guided nerve blocks (48). WALANT tumescence bathes all nerves, large and small. The small nerves are intensely numb with tumescence after 30 min, and epinephrine has had time to work in that time. It is therefore advised to inject 30 min before incising.

Indications

Over the last 20 years, the indications for the WALANT technique in hand surgery have increased. Most hand surgical procedures are feasible with the WALANT technique, but the clinical advantages are outstanding in dynamic surgery, where function is unpredictable if intraoperative active testing and fine-tuning is not possible. Therefore, tendon and double-joint finger surgery are the most important indications. Here, we will focus on the most common interventions of hand surgery under WALANT.

Minor surgical procedures

Commonly performed trigger fingers, carpal tunnels, cubital tunnels, de Quervain decompressions, and ganglion cyst excisions, are the procedures in which WALANT surgery improves cost, efficiency, and patient/surgeon convenience the most (52). Eliminating the tourniquet greatly improves the patient experience (53).

Trauma

Most simple hand traumas, such as fractures and lacerations of major structures, are easily managed with the WALANT technique (54). Local flap surgery is also safely performed (31, 55, 56). Although regional or general anesthesia in the main operating room is still preferred for major mangling of hands or replantation, for most simple traumas, WALANT provides a much more efficient venue in minor procedure rooms for tendon repair or simple K wiring with no increase in the rate of infections (57, 58, 59).

Tendon surgery

Tendon reconstruction is ideal for WALANT surgery. In flexor tendon tendon repair, active patient motion during the surgery aids in repairing gaps to avoid rupture, and with the adequate venting of pulleys to avoid tenolysis (27, 60, 61, 62). Balancing tendons in extensor hood repair can be tuned to perfection (63). Similarly, the reconstruction of pulleys and their function can be evaluated if the patient can actively move during surgery (49). A great application is the transfer of the extensor indicis proprius to reconstruct extensor pollicis longus function after rupture in wrist fracture. The classic advice to determine optimal transfer tension during motor block anesthesia is to study IP extension in passive wrist flexion and spontaneous thumb flexion in wrist extension. However, this rough estimate can lead to over or under tensioning of the transfer and secondary surgery. Seeing the patient move during surgery makes tensioning easy (64). Similar dynamic transfers to reconstruct lost motion such as opposition of the thumb have been described (65). Tenolysis of adherent tendons with stiff joints is ideal for WALANT hand surgery. It permits intraoperative testing of active motion to identify small remaining adhesions that can affect the result. Active motion during the procedure often helps to release the tendons and regain mobility (25).

Joint reconstruction

In trapeziectomy and thumb implant arthroplasty, balancing thumb motion can be challenging (66). WALANT may help with intraoperative release of adduction contracture or the stabilization of metacarpophalangeal instability if a swan-neck deformity persists during surgery (67). Reconstruction of interphalangeal joints with WALANT can provide active testing of the implants (68).

Double joint dysfunction

Nothing is more challenging in hand surgery than the reconstruction of finger motion with the combined pathology of all the tendons, ligaments, and muscles that act across two joints. Mallet finger with secondary swan-neck deformity and boutonniere dysfunctions are classic examples. in repair of the mallet with tenodermodesis, transarticular K-wiring of the distal interphalangeal joint (DIP) or splinting and in some cases fusion of the DIP often resolve the secondary hyperextension of the proximal interphalangeal joint (PIP) (Fig. 2). However, this is impossible to evaluate if the hand is paralyzed, and the necessity to add a PIP stabilizing soft tissue procedure is unpredictable. Boutonniere deformity may be even more challenging (26). The classical four-step Curtis procedure, where every step needs to be tested dynamically to steer decision-making, is only possible in active testing by the patient as is only possible with WALANT (69).

Figure 2.

Posttraumatic swan-neck deformity in a goal keeper (A), treated with Zancolli transfer and temporary extension-block K-wire reconstruction with intraoperative dynamic testing of fully achieved active flexion (B) and extension (C) of the finger under WALANT.

Dupuytren disease

In Dupuytren’s (Fig. 3), both the surgeon and patient receive immediate feedback on the dynamic result of cord release, which may positively influence further dissection as well as rehabilitation (50). Microfasciectomy, where the microscope is used during the surgical process, is perfectly feasible under WALANT (70).

Figure 3.

Illustrative intraoperative view of Boutonniere Dupuytren contracture deformity with fixed hyperextension of the DIP (A and B), treated by microfasciectomy and tendinous release (Fowler tenotomy) with the WALANT technique (extra material: video). Full active DIP flexion was achieved (C).

General condition of the patient

Patients with severe medical comorbidities are often confronted with hand problems that require surgery. However, the general condition may render sedation for surgery inadvisable. If these patients need surgical treatment of their pathology, WALANT makes it safer and possible. Tendon reconstructions, nerve decompression, and even infections can thus be treated without endangering the patient.

Future Prospects

Every year, new reports that push boundaries are published. There are recent reports of wrist surgery, radius, and ulna fracture plating, elbow surgery, clavicle plating, and major limb amputations (71, 72, 73, 74, 75, 76, 77, 78, 79, 80). Although the cost benefits of this approach in these cases are evident, the absolute indications for these procedures are not yet completely clear and are still limited to preferences or circumstances outruling other options (66, 81, 82, 83). WALANT in children is being explored with increasing experience (84). WALANT is increasingly adopted in hand surgery, but up to 40% of hand surgeons have still not yet incorporated it into their daily practice (34, 85). The COVID-19 pandemic did move the needle forward in using WALANT for many procedures (86, 87). It would be beneficial to include the WALANT technique in the surgical training curriculum, particularly for tendon repair and reconstruction in which the benefit of WALANT is likely to be higher (88). It will remain important that decision-making by the surgeons should be shared with the patient as the center and director of his own care.

Conclusion

The WALANT technique has become a game changer in hand surgery. While greatly decreasing costs and solid waste, this technique is increasing access to surgical care as well as safety in hand surgery. It is also helping us achieve better outcomes in some procedures such as tendon reconstruction. The adoption of this technique is becoming part of the algorithm of modern hand surgery practice. Continued learning, implementation, and research will improve this success story in daily practice.

ICMJE Conflict of Interest Statement

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of this instructional lecture.

Funding Statement

This instructional lecture did not receive any specific grant from any funding agency in the public, commercial, or not-for-profit sector.