Neurochirurgie 61 (2015) 30–34 Disponible en ligne sur ScienceDirect www.sciencedirect.com Surgical technique Endoscopically assisted proximal radial nerve decompression: Surgical technique Décompression proximale du nerf radial assistée par endoscopie : technique chirurgicale F.M.P. Leclère a,∗ , D. Bignion a , T. Franz a , L. Mathys a , C. Klimsa b , E. Vögelin a a Service de chirurgie plastique, chirurgie de la main et des nerfs périphériques, hôpital universitaire, Inselspital Berne, université de Berne, Freiburgstrasse, 3010 Bern, Switzerland b Service de chirurgie de la main, Kantonsspital Graubünden, Switzerland a r t i c l e i n f o Article history: Received 27 July 2014 Received in revised form 27 October 2014 Accepted 11 November 2014 Available online 31 January 2015 Keywords: Endoscopy Supinator syndrome Nerve compression Nerve constriction Hourglass-like constrictions a b s t r a c t State of the art. – The proximal radial nerve compression syndrome includes supinator syndrome and proximal radial nerve constrictions. This article presents a new endoscopic assisted radial nerve decompression surgical technique described for the first time by Leclère et al. in 2013. Surgical technique. – Endoscopic scissor decompression of the proximal radial nerve is always performed under plexus anaesthesia. It includes 8 key steps documented in this article. We review the indications and limitations of the surgical technique. Conclusion. – Early clinical results after endoscopic assisted decompression of the radial nerve appear excellent. However, they still need to be compared with conventional techniques. Clinical studies are likely to widely develop because of the mini-invasive nature of this new surgical technique. © 2015 Published by Elsevier Masson SAS. r é s u m é Mots clés : Endoscopie Syndrome supinateur Compression nerveuse Syndrome canalaire État de l’art. – Le syndrome de compression proximale du nerf radial regroupe le syndrome supinateur et les cas de constrictions. Cet article présente une nouvelle technique chirurgicale de décompression proximale du nerf radial assistée par endoscopie décrite pour la première fois par Leclère et al. en 2013. Matériel et technique chirurgicaux. – La décompression endoscopique par ciseaux du nerf radial est réalisée dans chaque cas sous anesthésie plexique. Elle comprend 8 étapes clés documentées dans cet article. Nous revenons sur les indications et les limites de la technique chirurgicale. Conclusion. – Les premiers résultats cliniques après décompression endoscopique du nerf radial dans sa partie proximale sont excellents. Ils doivent encore être comparés à ceux des techniques conventionnelles. Les études cliniques vont probablement se développer largement du fait du caractère mini-invasif de cette technique chirurgicale. © 2015 Publié par Elsevier Masson SAS. 1. Introduction The proximal radial nerve syndrome includes supinator syndrome and proximal radial nerve constrictions. Radial tunnel syndrome was first reported as a unique clinical syndrome in 1956 by Michele and Krueger [1]. This compression occurs in the proximal forearm where the radial nerve splits into the posterior interosseous nerve and the sensory branch of the radial nerve. Compression can occur either before or after this split. Six sites of potential compression have been underlined: ∗ Corresponding author. E-mail addresses: [email protected], [email protected], [email protected] (F.M.P. Leclère). • the proximal origin of the extensor carpi radialis brevis muscle (ECRB); http://dx.doi.org/10.1016/j.neuchi.2014.11.005 0028-3770/© 2015 Published by Elsevier Masson SAS. F.M.P. Leclère et al. / Neurochirurgie 61 (2015) 30–34 31 • • • • fibrous bands within the ECRB; a thickened fascial tissue superficial to the radiocapiteller joint; the radial recurrent vessels or leash of Henry; the arcade of Frohse (proximal border of the supinator muscle), and; • the distal border of the supinator muscle. Non-operative management is always prescribed initially and consists of rest and a tapered course of oral corticosteroids. When symptoms persist, an open surgical treatment is necessary to release the nerve compression sites. Since the first work of Tsai [2], endoscopically assisted decompression of peripheral nerves at the upper extremity has steadily developed and represents a reliable and reproducible alternative to conventional surgical technique for ulnar nerve [3–14] and median nerve compression [15–17]. After an initial assessment of the endoscopic assisted technique for decompression of the proximal radial nerve (unpublished data), we have successfully published our first clinical applications [15]. Herein: • we present the key steps of the endoscopically assisted proximal radial nerve decompression; • the discussion underlines the many benefits of this minimally invasive technique; • it presents the limits of the endoscopic nerve decompression and also the prospects for future development. 2. Material and surgical technique Fig. 1. Endoscope used for decompression of the proximal radial nerve. Endoscope utilisé pour la décompression proximale du nerf radial. 2.2. Step two: anaesthesia Endoscopically assisted proximal radial nerve decompression is performed under plexus anaesthesia, where necessary under general anaesthesia with a sterile tourniquet applied. 2.3. Step three: installation of the patient The checklist must be performed carefully. Special attention is given to the material, and the side of the decompression. The correct positioning of the patient is important for a successful operation. To simplify access for the surgeon, the hand table should be as high as possible. This allows a better view of the operative site. The involved arm is slightly flexed in the elbow and held in neutral or slight pronated position. 2.1. Step one: the material The material includes a 4 mm 30◦ endoscope (Karl Storz, Tuttlingen, Germany) (Fig. 1), a speculum with light attachment, a bipolar cautery, Metzenbaum scissors and Duplay dressing forceps. 2.4. Step four: marking the first incision A 2- to 3-cm incision is made no more than 5 cm proximal to the elbow joint following the line from the insertion of the deltoid to the Fig. 2. Drawing of the first skin incision for the proximal decompression of the radial Nerve. B,C,D: In obese or very muscular patients: incision 4 cm proximally slightly anterior between the brachioradial and triceps muscles (1: deltoid muscle; 2: biceps muscle; 3: triceps brachii muscle (lateral head); 4: lateral intermuscular septum; 5: first skin incision; 6: first skin incision slightly anterior in obese patients; 7: musculocutaneous nerve; 8: radial nerve between brachioradial and triceps muscle). Schéma de la première incision cutanée pour la décompression proximale du nerf radial ; B,C,D: Pour les patients obèses ou présentant une masse musculaire importante : incision à environ 4 cm du pli du coude et plus antérieure entre les muscles triceps brachial et brachioradial (1 : deltoïde ; 2 : biceps brachial ; 3 : triceps brachial (vaste latéral) ; 4 : septum intermusculaire latéral ; 5 : première incision cutanée ; 6 : première incision cutanée plus antérieure pour les patients obèses ; 7 : nerf musculo-cutané ; 8 : nerf radial entre les muscles triceps brachial et brachioradial). 32 F.M.P. Leclère et al. / Neurochirurgie 61 (2015) 30–34 Fig. 3. A–D: The second incision is made distally where the light of the endoscope (introduced from proximally) can be seen 5 cm distal to the extended elbow joint (1: deltoid muscle; 2: biceps muscle; 3: triceps brachii muscle (lateral head); 4: lateral intermuscular septum; 5: first skin incision; 6: brachioradialis muscle; 7: light of the endoscope; 8: superficial radial nerve; 9: deep radial nerve; 10: supinator branches; leash of Henry). A–D : La deuxième incision est dessinée, à l’endroit précis où la lumière de l’endoscope (introduit par l’incision proximale) peut être vue 5 cm en distal par rapport à l’articulation du coude, avant-bras en extension (1 : deltoïde ; 2 : biceps brachial ; 3 : triceps brachial (vaste latéral) ; 4 : septum intermusculaire latéral ; 5 : première incision cutanée ; 6 : muscle brachioradial ; 7 : lumière de l’endoscope ; 8 : nerf radial superficiel ; 9 : nerf radial profond ; 10 : rameau supinateur ; 11 : anse vasculaire de Henry). lateral epicondyle (Fig. 2A). In obese or very muscular patients we recommend an incision 4 cm proximally slightly anterior between the brachioradial and triceps muscles. 2.5. Step five: decompression at the arm level and up to 5 cm distal to the elbow joint Under direct visualization, and then with an illuminated speculum, dissection is carried out through the subcutaneous layers to the level of upper arm fascia. The fascia and lateral intermuscular septum are carefully opened allowing direct visualization of the radial nerve. In patients with strong upper arm muscles such as the triceps or the extensor carpi radialis longus origin, it is not so easy to visualize the radial nerve in this area (see further down). After blunt tunnelling with forceps, the endoscope is introduced in the superficial plane to complete the opening of the fascia, followed by opening of the intermuscular septum. The radial nerve is neurolyzed proximally and distally up 5 cm distal to the elbow joint with the elbow extended. 2.7. Step seven: decompression at the forearm level Under direct visualization, dissection is performed through the subcutaneous layers to the level of the extensor muscles fascia. The illuminated speculum is inserted. The interval between the BR and the ERCL, or corresponding extensor muscles is opened and the posterior interosseous nerve exposed. It is previously identified using the first incision which allows a neurolysis 5 cm distal to the elbow joint (Fig. 4). After blunt tunnelling with forceps, the endoscope is introduced under the extensor muscles. In case the radial nerve at the upper arm is not easily found, dissection is first performed at the proximal forearm level, and then retrograde continued to the proximal forearm with the help of the endoscope light (diaphanoscopy). The neurolysis is completed, first proximally, then distally. Known anatomical compression of the nerve (Arcade of Frohse, leash of Henry (Fig. 3D), fibrous edge of the ECRB) and the distal accessory bands, sequelae of traumatic injury and idiopathic constriction of the nerve, can be exposed and the nerve released from the pathologic structures. 2.8. Step eight: postoperative care 2.6. Step six: Marking the second incision at the forearm level A second 2- to 3-cm longitudinal incision is made distally where the light of the endoscope (introduced from proximally) can be seen 5 cm distal to the elbow joint (Fig. 3). This is usually on the lateral surface of the proximal forearm overlying the interval between the brachioradialis (BR) and extensor carpi radialis longus (ECRL), beginning approximately 5 cm past the elbow flexion crease and extending distally. A separate incision, medial to the BR, allows good visualization of the superficial branch of the radial nerve but requires a larger exposure to visualize the deep branch. An elastic elbow bandage is prescribed for 4 weeks. Patients are advised to avoid strenuous upper extremity activity and not allow these extremities to hang for too long as the effects of gravity might cause painful and uncomfortable oedema. 3. Discussion In this article, we have presented in detail the surgical technique of endoscopic decompression of the proximal radial nerve in the supinator and constriction syndromes. We have emphasized F.M.P. Leclère et al. / Neurochirurgie 61 (2015) 30–34 33 Fig. 4. Neurolysis of the proximal (A) and distal (B,C) radial nerve under endoscopy; (1: biceps muscle; 2: fat pad on the humerus; 3: hourglass-like constrictions; 4: common radial nerve; 5: branches to ECRB; 6: deep radial nerve; 7: supinator branch fatty degenerated; 8: superficial radial nerve). Neurolyse du nerf radial proximal (A) et distal (B,C) sous endoscopie (1: biceps brachial ; 2 : cousssinet adipeux sur l’humerus ; 3 : torsion du nerf ; 4 : nerf radial ; 5 : rameaux pour le muscle ECRB ; 6 : branche motrice du nerf radial ; 7 : rameau supinateur atrophique ; 8 : branche sensitive du nerf radial). the possibility to visualize and release the sites of nerve compression while staying mini-invasive. The technique presented here was adapted from the one previously used for cubital tunnel syndrome. The latter was introduced in 1995 by Tsai et al. and since its publication [2], two types of surgical endoscopic assisted nerve decompression techniques have been used: knife [3–6] and scissors [7–14] techniques. Despite the sometimes excellent results reported in the literature, endoscopic assisted knife techniques are in our opinion hazardous because of the discrepancy between the size of the instruments and that of the nerve, and the inherent resulting potential for intraoperative nerve injuries. Conversely, the technique using scissors described for the first time by Porcellini [7] and popularized by Hoffmann and Siemionow [8,9] is much easier and safer to use in the compression or constriction nerve syndrome. Irrespective of the brand of instruments used, whether the one developed by Hoffmann [8,9] or the other reported in the study of Leclère et al. [11,12], the technique is standardized. It offers excellent functional and subjective outcomes. After excellent experience and several studies performed on the endoscopic ulnar nerve decompression, we have studied, in the laboratory, the possibility of using this technique for rare compression syndromes: • the proximal median nerve endoscopic decompression was discussed in a previous report [15]; • the proximal radial nerve endoscopic assisted decompression was for the first time performed by our team [15] after precise preparation and planification of the surgical procedure in the laboratory of anatomy. This technique, which involves two incisions, permits a safe neurolysis unlike endoscopic techniques with knives. Moreover, this mini-invasive surgical procedure allows to both identify and remove all the compressive structures. It also makes it possible to perform the neurolysis without compromising the blood supply of the nerve and reduces scar formation because of the limited opening of the skin and subcutaneous tissues. Moreover, the smaller scar seems to be an additional advantage. Finally, we hypothesized that this technique will significantly grow and develop in the near future for other indications including nerve assessment in cases of humerus fracture. With intact anatomy, the radial nerve in the spiral groove may not be visualized easily using the long trocar of the endoscope. However, with a fracture and possible loosening of the muscle this might be a good possibility to follow the nerve. Despite the promising results in the literature, this technique seems confronted with the following limits: • firstly, these syndromes are rare and the majority of patients are initially treated with conservative therapy, which is usually sufficient to recover the affected nerve function; • secondly, as a consequence of the small number of patients, diffusion of the technique is difficult because a comparative study with conventional surgery is still lacking. Certainly, in the first weeks patients have more comfort with endoscopically assisted surgery than with open surgery [11,12]. Finally, besides the rarity of nerve compression syndromes, another aspect explains the limited development of the endoscopic technique for nerve entrapment or constriction. The price of the equipment was initially prohibitive. The affordability of new instruments, their rapid amortization and the aforementioned benefits should contribute to a wider use of this powerful tool. 4. Conclusion Early clinical results after endoscopic assisted decompression of the radial nerve appear excellent. Nevertheless, they still need to be compared with conventional techniques. Clinical studies are likely to greatly develop because of the mini-invasive nature of this new surgical technique. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Michele AA, Krueger FJ. Lateral epicondylitis of the elbow treated by fasciotomy. Surgery 1956;39:277–84. [2] Tsai TM, Chen IC, Majd ME, Lim BH. Cubital tunnel release with endoscopic assistance: results of a new technique. J Hand Surg [Am] 1999;24:21–9. [3] Carlier Y, Prové S, Desmoineaux P, Boisrenoult P, Beaufils P. Décompression in situ du nerf ulnaire au coude par technique endoscopique : à propos de 22 cas. Rev Chir Ortho & Traumat 2005;2:91–6. [4] Bain GI, Bajhau A. Endoscopic release of the ulnar nerve at the elbow using the Agee device: a cadaveric study. Arthroscopy 2005;21:691–5. [5] Ahcan U, Zorman P. Endoscopic decompression of the ulnar nerve at the elbow. J Hand Surg [Am] 2007;32:1171–6. [6] Nakao Y, Takayama S, Toyama Y. Cubital tunnel release with lift-type endoscopic surgery. J Hand Surg [Am] 2001;6:199–203. 34 F.M.P. Leclère et al. / Neurochirurgie 61 (2015) 30–34 [7] Porcellini G, Paladini P, Campi F, Merolla G. Arthroscopic neurolysis of the ulnar nerve at the elbow. Chir Organi Mov 2005;90:191–200. [8] Hoffmann R, Siemionow M. The endoscopic management of cubital tunnel syndrome. J Hand Surg [Eur] 2006;31:23–9. [9] Hoffmann R, Meek MF. Endoscopic decompression of the ulnar nerve at the elbow. J Hand Surg [Am] 2008;33A:615–6. [10] Bultmann C. Ergebnisse der endoskopischen dekompression des nervus ulnaris bei kubitaltunnelsyndrome. Handchir Mikrochir Plast Chir 2009;41:28–34. [11] Leclère FM, Manz S, Unglaub F, Cardenas E, Hahn P. Endoscopic decompression of the ulnar nerve in the cubital tunnel syndrome: about 55 patients. Neurochirurgie 2011;57:73–7. [12] Leclère FM, Germain MA, Hahn P. Neurolyse microchirurgicale du nerf ulnaire assistée par endoscopie dans le syndrome cubital au coude. Acad Fr Chir 2013 [In Print]. [13] Cobb T, Sterbank P. Comparison of return to work: endoscopic versus open cubital tunnel release. Sydney: Poster IFSSH; 2007. [14] Cobb TK, Sterbank PT, Lemke JH. Endoscopic cubital tunnel recurrence rates. Hand [NY] 2010;5:179–83. [15] Leclère FM, Bignion D, Franz T, Mathys L, Vögelin E. Endoscopically assisted nerve decompression of rare nerve compression syndrome at the upper extremity. Arch Orthop Trauma Surg 2013;133:575–82. [16] Keiner D, Tschabitscher M, Welschehold S, Oertel J. Anterior interosseous nerve compression syndrome: is there a role for endoscopy? Acta Neurochir (Wien) 2011;153:2225–9. [17] Lee AK, Khorsandi M, Nurbhai N, Dang J, Fitzmaurice M, Herron KA. Endoscopically assisted decompression for pronator syndrome. J Hand Surg Am 2012;37:1173–9.
