Acute Carpal Tunnel Syndrome following Sclerotherapy for the Treatment of Upper Extremity Venous Malformation

Venous malformations (VMs) of the upper extremity can be difficult to manage owing to intimate association with healthy anatomy. Sclerotherapy and embolization are mainstays of treatment as they avoid the inherent morbidity of open surgery, limit blood loss, and feature a relatively low complication rate. Despite the relative safety of these procedures, instances of neurological complications are reported in approximately 10% of cases and chiefly include self- limited hypoesthesia, dysesthesia, and weakness.[1] Cases of acute compression neuropathy, however, are virtually unheard of.

We report a case of a 15-year-old, right hand dominant female presented to the hand surgery service as a consultation from the interventional radiology service. Her primary concern was acute onset of burning pain, numbness, and swelling in left hand that arose following injection of 1% sodium tetradecyl sulfate (STS) into a continuous VM of the left middle finger, thumb, volar wrist, forearm, and axilla earlier that day. Her medical history was notable for an extensive, infiltrative superficial, and intramuscular VM of her left upper extremity, extending from her axilla to fingers, initially diagnosed at age 10. She had undergone 13 prior sclerotherapy treatments to this VM with either STS or bleomycin injections.

The initial physical examination was notable for a grossly edematous hand with violaceous mottling of all digits. The hand was appropriately warm and perfused and the compartments of the arm and hand were soft. Vascular examination was normal. Neurological assessment was significant for near anesthesia in the median nerve distribution. At this point, a diagnosis of acute carpal tunnel syndrome (aCTS) was made and the patient was brought to the operating room for emergent carpal tunnel release.

Prior to the initiation of the operation, an ultrasound examination was performed that demonstrated an occlusive thrombus of an unpaired left brachial vein. The operation was thus performed under general anesthesia without tourniquet control. A Bruner’s incision was made across the volar aspect of the wrist. Upon incision of the dermis, a large, swollen vascular structure, most consistent with a malformation, protruded through the incision and obscured the view of the deeper structures ([Fig. 1]). There was no hematoma or other mass lesion. The transverse carpal ligament was released in its entirety. The decision was made to forego dissection to the deeper structures of the carpal tunnel given the high risk of bleeding in the absence of a tourniquet. Soft compartments were again verified. There were no intraoperative complications and the skin was loosely closed.

Fig. 1 Appearance of the wrist after incision in the index operation. The vascular malformation can be clearly seen effacing the normal tissue planes. There is no hematoma or other mass lesion that could account for the patient’s acute carpal tunnel syndrome.

Her immediate postoperative course was notable for mild improvement in pain and numbness in the median distribution. By postoperative day 1, she reported increasing anesthesia in the palmar cutaneous nerve distribution and increased edema at the dorsal wrist. She could not tolerate electromyography, thus magnetic resonance imaging of the extremity was performed on postoperative day 2. This study showed mild edema surrounding the VM with intimate association of the median nerve, such that the malformation could not be distinguished from the nerve. We proceeded with conservative management.

By postoperative day 5, she had reduced edema in her digits but her sensory examination remained concerning for a focal lesion to the median nerve proximal to the carpal tunnel, given her palmar cutaneous nerve involvement. Using light sedation, the patient underwent a high-resolution ultrasound examination of left upper extremity, which was notable for a flattened appearance of the median nerve with loss of the normal fascicular pattern from the level of the carpal tunnel to approximately 8-cm proximal. Based on these findings, a reexploration was performed on day 6. The forearm fasciotomy was taken from the level of the carpal tunnel to the antecubital fossa. Notably, the VM had contracted, allowing the identification and isolation of the median nerve within the carpal tunnel, though the nerve appeared intimately associated with the vascular malformation. Internal neurolysis was not performed.

Postoperatively, she experienced a significant improvement in pain from her forearm distally, as well as improved sensation in the median nerve distribution. Her condition stabilized and she was discharged 3 days later.

Nerve injury is an uncommon complication of sclerotherapy. Such an adverse event typically occurs in settings where the VM is closely associated with a nerve, resulting in neuroinflammation secondary to the sclerosant itself or a neurapraxia spectrum physical injury. Few studies have evaluated the underlying mechanisms contributing to sclerotherapy-induced nerve injury, but it has been attributed to several pathologies: direct contact of the nerve with sclerosing agent, damaged venous outflow of the nerve, reflux of the sclerosant into the nerve’s arterial supply, and nerve compression due to postprocedural edema.[2] Regardless of the cause, the majority of these incidents self-resolve over a period of days to months.[2]

In a systematic review of 1,214 patients, the reported risk of a neural complication after VM sclerotherapy was 1.85%.[1] Regarding STS sclerotherapy, specifically, Aronniemi et al reported just one neurological injury, temporary sensory loss in one digit, in a series of 127 patients who underwent 280 STS VM sclerotherapy procedures.[3] Tan et al also described their experience with just one neural complication, a “superficial nerve injury” causing temporary forearm numbness, in a series of 226 STS injections for sclerotherapy.[4] Perhaps the most informative publication to date is a case series by Stuart et al that studied 204 patients undergoing 647 STS sclerosing procedures.[5] They identified seven cases of neuropathy for a 1.1% incidence. Interestingly, two of these patients required surgery: one patient underwent an elective carpal tunnel release and the second was treated with external neurolysis of the ulnar nerve.

This case emphasizes the importance of multidisciplinary teams and preprocedural planning for the management of VMs. Perhaps median nerve release could have been offered to this patient at the time of sclerotherapy to prevent acute neuropathy, although the rarity of this complication may argue against routine prophylactic surgery.

Publication History

Article published online:
17 September 2020

• References

• 1 Qiu Y, Chen H, Lin X, Hu X, Jin Y, Ma G. Outcomes and complications of sclerotherapy for venous malformations. Vasc Endovascular Surg 2013; 47 (06) 454-461
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• 4 Tan KT, Kirby J, Rajan DK, Hayeems E, Beecroft JR, Simons ME. Percutaneous sodium tetradecyl sulfate sclerotherapy for peripheral venous vascular malformations: a single-center experience. J Vasc Interv Radiol 2007; 18 (03) 343-351
• 5 Stuart S, Barnacle AM, Smith G, Pitt M, Roebuck DJ. Neuropathy after sodium tetradecyl sulfate sclerotherapy of venous malformations in children. Radiology 2015; 274 (03) 897-905