ESRA19-0470 PRO

Field: Medicine (Health Sciences)

'Wide Awake Local Anesthesia No Tourniquet' block, named WALANT, is a technique that was described by Dr Lalonde, a Canadian hand surgeon. Many articles have been published by the same team, all highlighting the good sides of this technique. a book written by Dr Lalonde is available and you can watch his promotional videos on the Internet. However, the real reasons for the development of that technique, and its scientific 'communication campaign' by Dr Lalonde, seems to be more the lack of anesthesiologists in some areas of Canada, and that some hand surgeons do believe that they could perform their procedures outside of surgical theatres, for economical concerns. So we should ask ourselves today: why do we need a new technique for hand and wrist surgery, whereas axillary brachial plexus nerve block is a known and safe technique, for reasons that are not initially a medical problem?

What are the 'good sides' of WALANT, according to its defenders, that should make us stop regional anesthesia (RA)?

(1) To avoid the tourniquet during surgery?: the studies showing cases of nerve injuries related to the use of tourniquet often describe long duration (more than an hour) of tourniquet located at the arm.11 We know today that a tourniquet for hand surgery can be located at the wrist, which was proved to be the best location in terms of comfort and ability to obtain a bloodless surgical site.7 the tolerance of the tourniquet can be quite good, as was demonstrated on awake healthy volonteers, and can be improved by reducing the pressure from 250 mmHg to 200 mmHg, without increasing the bleeding of the surgical site,4 for short surgeries, like those concerned by the WALANT use. Finally, the axillary brachial plexus blockade can provide a sensory block of the tourniquet area, when the medial cutaneous nerve of the arm is targeted, by adapting the technique of RA.10 (2) For better comfort of the patients?: the comfort of the patient during the WALANT procedure is something that is not often registered in many of those recent studies (as they are mostly made by surgical teams). It is known that injection of LA in the wrist area is more painful than in the axillary area,5 and so is the injection for the WALANT. It is therefore sometimes required to sedate the patients, as some teams using WALANT do. Injecting 50 mL of a solution in the wrist cannot be a painless procedure, whatever its defenders pretend. Axillary brachial plexus blockade is therefore possible without premedication or sedation, especially with ultrasound guidance using the out-of-plane approach.12 (3) the possibility to avoid recovery room?: This specific possibility of WALANT, compared with RA, is in some countries, not true anymore; for instance, in France, it is now allowed to discharge the patient from operating room directly after surgery if the upper limb RA was performed more than 45 minutes before.6 (4) To avoid 'anesthesia security rules'? (monitoring, consulting, etc.): the aim of the defenders of the WALANT block is to process to surgery outside of the operating theatre, pretending that the septic risk is not increased. This 'theory' is unfortunately not proved and would take us back to a time when surgeons did not wear gloves and surgical clothes. Do we really want and need that? Moreover, the injection of 500 mg of lidocain, even if this dose is not dangerous, can always lead by mistake to an intravenous injection, with immediate neurological and cardiac complications. Therefore, it is not possible in the 21st century to go back on some security rules, like monitoring our patients for any RA, and being in a structure that can provide intra-lipid solutions and a medical assistance. (5) To decrease blood loss?: a recent study compared WALANT to general anesthesia and showed that blood loss is greater with WALANT, and that no difference is found regarding operative time, or rehabilitation after 12 months, for radial fracture surgery,1 although pro-WALANT (mainly hand) surgeons pretend that the preservation of motoricity during the surgery could improve the functional result of the surgery2; this is not proved today. (6) To keep the motoricity and sensitivity during surgery?: This consequence of WALANT allows, of course, the surgeon to work in better conditions and have a more precise view of tendon repairs for instance, which we totally understand. But we must say that today, we don't know if this specificity of WALANT leads to a change in the functional results of those surgeries.1 Further studies should be done about that. Also, some say it could avoid the 'wrong' representation of the personnal anatomy, compared with axillary blockade, which could be a cause of algodystrophy/regional complex pain syndrome. No study has been published yet about that, whereas axillary blockade has proved for a long time to be a way of preventing regional complex pain syndrom after hand surgery.3

What are the bad sides of WALANT?

(1) Adrenalin in the fingers?: Even if the literature about this topic is mainly from the 1950s and related to the use of procaine, we still find today some cases published about digital necrosis using epinephrine, like recently, 3 case reports documenting adverse effects associated with lidocaine and epinephrine in digital blocks,8 which lead the authors to recommand to always have phentolamine as an antidote for vasoconstriction caused by epinephrine in the fingers. It is very hard to understand that the same team can pretend that epinephrine is safe in hand surgery and can be used without 'regular anesthesic security rules' and then recommand having the antidote available! Moreover, this represents an additional cost for a technique that is supposed to be less expensive. Also, teams performing WALANT often contra-indicate it to vascular patients, diabetic neuropathy, and avoid therefore all injections inside the finger pulp and the flexion-muscles shelf. (2) Its organisation is not as simple and easy as some would want us to believe: the injection has to be finished at least 30 minutes minimum before surgery (for hemostatic vasoconstriction effect to start). This is much longer than the onset times of an ultrasound axillary brachial plexus blockade performed today, which is around 15 minutes.9 It requires the same security conditions of any anesthesia, including an IV catheter, a preanesthesia consulting and standard monitoring. Moreover, it sometimes requires complementary local anesthesia during surgery, made by the surgeon, which is really not satisfying and comfortable for the patient, but with a frequency that is not given in the recent articles about WALANT.13 (3) It does not provide analgesia!: the duration of action of lidocaine is short, as we all know. WALANT makes us come back to considerations that have disappeared 30 years ago: It is not acceptable today to only provide an anesthesia technique without providing a sufficient analgesia. Some of the 'WALANT' teams even perform an axillary blockade AFTER the surgery so as to control the pain, which involves cumulative risks of toxicity for the LA doses, is uncomfortable for the patients, and proves how unadapted WALANT is. (4) There are today no good scientific data about its safety and advantages: the literature about regional anesthesia, and axillary brachial plexus nerve block, is from a higher scientific level than WALANT. We have many good quality studies about RA, whereas WALANT articles are mainly about small numbers of patients without any randomised control trials, which limits the level of validity of their conclusions.

References

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