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Neuroma of the Superficial Branch of the Radial Nerve After Intravenous Cannulation

1996; Lippincott Williams & Wilkins; Volume: 83; Issue: 1 Linguagem: Inglês

10.1213/00000539-199607000-00032

1526-7598

Shalom Stahl, Theodore Kaufman, Bruce Ben-David,

Orthopedic Surgery and Rehabilitation

In spite of the rich sensory innervation of the upper extremity and the vast number of peripheral vein cannulations that are performed, there are very few reported cases of nerve injury from such cannulation. This suggests not only an extremely low incidence of the complication, but also that perhaps the problem is not recognized and diagnosed. We report here a case of a neuroma of a superficial branch of the radial nerve after intravenous cannulation and describe both its presentation and treatment. Neuromas or neuritis of the superficial sensory branch of the radial nerve have been reported after surgical release of DeQuervain syndrome [1-3], in association with Wartenberg's syndrome [4-6], and after wounding at the distal third of the forearm [6]. However, there is only one previous report of injury to the radial nerve after peripheral venous cannulation [7]. In that case, the patient went untreated and was left with a complete work disability. This additional case report emphasizes the importance of considering this diagnosis of a very real, painful, and progressively disabling entity. It also illustrates various management options for treating this rare complication and the potential for complete recovery. Case Report A 45-yr-old, right-handed laborer presented for elective repair of a right inguinal hernia under general anesthesia. Immediately after preoperative venous cannula placement in the dorsolateral aspect of the wrist and prior to administration of any drug, the patient complained of excruciating pain and paresthesias of his hand. Anesthesia was nevertheless induced, and both anesthetic drugs and fluids were administered via the cannula. There was no evidence of extravasation of administered intravenous fluid in the subcutaneous tissues. Anesthesia and surgery proceeded uneventfully. Postoperatively, the patient continued to complain of pain, hypersensitivity, and paresthesias of the dorsoradial surface of the distal third of his forearm radiating to the dorsum of the hand, thumb, and index finger. Follow-up revealed that the patient had been unable to return to work because of the pain, which had become so severe that he could not wear a wristwatch. Four months postoperatively, the patient was referred to the Hand Surgery Unit. On examination there was found a tender palpable mass in the vicinity of the styloid process of the radius. Direct tapping over it elicited painful paresthesias radiating to the dorsum of the hand, which were exacerbated by ulnar-volar flexion of the wrist and by hand grip. Unsuccessful conservative management over the next 2 mo included local massage, repeated light tapping of the sensitive area, short-wave ultrasound treatment, transcutaneous electrical nerve stimulation, and nonsteroidal antiinflammatory analgesics. Six months after the original surgery, the patient was brought to surgery for exploration of the left wrist. Surgical exploration revealed a fusiform hard swelling of the superficial sensory branch of the radial nerve. The neuroma was in continuity with the nerve, having twice the diameter of the nerve proximal to it. Resection of the neuroma created an unbridgeable gap of 2.5 cm between proximal and distal remnants of the nerve. The proximal end of the nerve was therefore transposed and embedded in the brachioradialis muscle. Postoperative follow-up at 8 mo (14 mo after the original surgery) revealed the patient to be pain free. There continued to be a mild hypoesthesia over the dorsum of his hand (diminished two-point discrimination) which was not clinically significant. The patient was able to wear a watch on the affected hand with no irritation and had returned to full employment, experiencing no further difficulties. Discussion Neuromas of the superficial branch of the radial nerve occur mainly after crush injuries to the wrist [6] and after surgical interventions at this site such as after release of DeQuervain's stenosing tenosynovitis [1-3]. Injury to this nerve during venous cannulation has been described in a dental hygienist who developed a disabling neuroma associated with significant weakness, painful paresthesias, and hypersensitivity of the wrist and hand [7]. Other nerve injuries after venipuncture have been reported but are also rare. These include a case of transient radial nerve palsy after venipuncture at the antecubital fossa for blood donation [8] and median nerve neuropathy secondary to hematoma formation with local compression of the nerve after percutaneous puncture of the brachial artery in a patient receiving anticoagulant therapy [9]. When a nerve is cut, it undergoes first a process of wallerian degeneration followed by regeneration. The end neuroma that is the distal growing end of the regenerating nerve may not "reconnect" and instead may form a large and pathological focus of ectopic electrical discharge. This produces a clinical picture of neuropathic pain, which includes such features as dysesthesias, paroxysmal pain, allodynia, and pain in the absence of ongoing tissue damage. There are also many other possible ways that a neuroma might develop, such as secondary to stretch injury or blunt (crush injury) trauma to a nerve [10]. Although painful neuromas may occur after injury to any nerve, there is some evidence that the superficial branch of the radial nerve carries a particular anatomic predisposition to this complication [5]. The explanation for this vulnerability is probably a combination of both the exposure of the nerve due to its superficiality and its lack of cushioning from muscle and fatty tissue, being that it is close to underlying bone. The sensory distribution of the nerve is variable but is limited to the dorsolateral hand, providing no innervation to tactile surfaces. It is a purely sensory nerve having no motor component. Therefore, injury to the superficial branch of the radial nerve is debilitating not as a result of neural loss, but rather due to the pain syndrome that develops afterward. In the present case, intravenous catheter insertion probably lacerated a superficial branch of the radial nerve inducing the formation of a neuroma. It is unlikely that subcutaneous extravasation of drug was responsible for nerve injury, as the patient's symptoms began immediately on placement of the intravenous catheter and prior to the administration of any drugs. The symptoms associated with this nerve injury were similar to those described by Wartenberg in five patients in 1932 [4]: persistent pain on the dorsoradial aspect of the distal third of the forearm radiating to the dorsum of the hand, thumb, and index finger. In addition, this syndrome is characterized by the inability to tolerate the wearing of jewelry or a watch band [11], as was observed in our patient. As time passes after injury, the neuroma enlarges and attaches to surrounding soft tissue; hence, the movements of ulnar-volar flexion of the wrist and hand grip cause stretching of the nerve and elicit symptoms. Because the initial nerve injury may produce a sensation of "electrical shock" [7], such a complaint should alert one to the possibility of nerve damage and its sequelae. Conservative treatment options go beyond those used in this case. Repeated local anesthetic blocks, with or without depot corticosteroids, may be useful, as may cryoneurolysis or lytic blockade with phenol [12]. Pharmacologic therapy may be tried with drugs such as carbamazepine or mexiletine [13]. When conservative therapies are not successful, surgical intervention is warranted. There are several approaches to surgical repair of the nerve. Early postinjury direct suturing of severed nerve ends is recommended whenever their approximation is possible without tension. Where this is not feasible, the interposition of a nerve graft is seldom justified in view of the frequently unfavorable outcome [14]. In such a case, it is preferable to perform a simple submuscular implantation of the proximal nerve end [15,16]. To prevent reformation of a neuroma, the proximal severed nerve end may be bathed in absolute alcohol and ligated with sutures [17]. This practice is considered controversial, and in our patient this was not done. In this case, six months had elapsed between injury and surgical intervention, allowing for development of a large neuroma, the resection of which left a large and unbridgeable gap between severed ends of the nerve. Therefore, the proximal end of the superficial branch of the radial nerve was implanted under the brachioradialis muscle. This led to complete and lasting relief of the patient's pain and enabled him to return to full employment. In conclusion, we report a case of injury of the superficial branch of the radial nerve after simple venipuncture. This injury led to severe chronic pain and complete work disability that persisted for months after surgery for inguinal hernia repair. It is important to recognize that such a complication, although rare, can occur. It is not certain that immediate removal of the intravenous catheter would have altered the outcome, but there is room for such speculation. It may therefore be wise, in the instance of extraordinary pain on intravenous catheter insertion, to relocate the catheter to an alternative site. Awareness and recognition of this complication is particularly important because it can be debilitating and is often eminently treatable. Early diagnosis and treatment offers the patient the chance for speedy recovery and a good long-term prognosis in a high percentage of cases.