Discussion: Neurectomy of the Nerve of Henle Associated with Periarterial Sympathectomy for Management of Intractable Raynaud Phenomenon

As the authors point out,1 there is no consensus regarding the best periarterial sympathectomy technique for intractable Raynaud syndrome, or even whether it is a palliative2 or a definitive3 treatment. The extent of adventitial stripping and incision choice vary widely. In the absence of an evidence-based conclusion, anatomical study and clinical experience are our best guidelines. Immunofluorescent4 and anatomical studies5 show the nerve of Henle providing the predominant sympathetic innervation of the distal ulnar artery, the only named peripheral sympathetic nerve. The remaining sympathetic innervation occurs in a segmental fashion, like teeth of a comb, from nerves adjacent to accompanying arteries.5 The nerve of Henle is important because occlusion of the ulnar artery is common in connective tissue disease patients, with autopsies showing evidence of this in approximately 50% of scleroderma patients.6 In one series of intractable Raynaud patients, over half already had ulnar artery occlusion at the time of surgery.3 Extensive denervation of the intact ulnar artery, as done in this study, likely prevents future occlusion as suggested in a previous study.3 Anatomical studies show that the nerve of Henle usually innervates the ulnar artery in the mid forearm, as found in this study. It is less often seen more distally, but still well proximal to the 2- to 3-cm ulnar wrist incision typically found in the literature.2 This leaves the innervated ulnar artery vulnerable to late occlusion in patients with limited sympathectomy.7 The authors solved this by proximal neurectomy of the nerve of Henle, well described and filmed. They also performed extensive circumferential periarterial sympathectomy of the ulnar artery, denervating the additional contribution from the medial antebrachial cutaneous branches at the distal forearm. Segmental periarterial sympathectomy to femoral and axillary arteries in the early twentieth century had good initial results, but in 1921 Leriche published analysis of late failures in these patients, believing segmental sympathectomy allowed nerve growth to bypass the operative site.8 Experimental studies suggest that adrenergic response is completely eliminated only at the adventectomy site.9 This encourages adventectomy without skip areas where the nerve can regenerate and bypass, accomplished by in-continuity stripping. The authors describe their in-continuity approach, from ulnar artery circumferential periarterial adventectomy through all of the vasculature to the level of bifurcation of the proper digital vessels. This is very similar to the "extended periarterial sympathectomy" technique described previously,3 differing only in that the latter procedure extended into the base of the digits and over the dorsal artery on the thumb web to denervate the princeps pollicis artery, which is innervated by the superficial radial and lateral antebrachial cutaneous nerves in the snuffbox and distally.5 In this article, the authors included the clever addition of neurectomy of the nerve of Henle in 95% of their patients, even when it required a separate proximal incision. Neither of these two articles had reports of any significant forearm or hypothenar sensory loss as had been predicted in earlier anatomical study.10 The patient-reported results in this study are excellent, and preoperative and postoperative assessments more comprehensive than previously reported. Their success finding and dividing the nerve of Henle raises the attractive possibility of early intervention for severely symptomatic connective tissue disease patients at risk of later ischemic ulceration and ulnar artery occlusion. Their technique could be performed with minimal morbidity, and it would not interfere with later extensive periarterial sympathectomy if needed. It will be important to follow these patients to see whether indeed this prevents late ulnar artery occlusion. Their results show long-term benefits well beyond mere palliation. DISCLOSURE The author has no financial interest to declare in any of the drugs, products or devices mentioned in this Discussion or in the associated article.