P053: SUCCESSFUL UTILIZATION OF BOTULINUM TOXIN-A FOR CHEMO DENERVATION OF ANTERIOR AND MIDDLE SCALENE MUSCLES FOR TREATMENT OF NEUROGENIC THORACIC OUTLET SYNDROME.
Christina Brooks, MD; Oleksiy Lelanov, DO; William Grubb, MDDDS; Rutgers RWJ University Hospital
Introduction: Use of Botulinum toxin-A (BTX-A) for chemo denervation of the anterior (ASM) and middle scalene (MSM) muscles for neurogenic thoracic outlet syndrome (NTOS) has been documented as early as 19391,4,5. Initial indications for BTX-A were for diagnosis, serving as a surgical procedure predictor for NTOS1. Utilization of BTX-A as a treatment modality has been successfully shown in small case studies2,3. However, no prospective studies have been conducted showing the efficacy of BTX-A for NTOS treatment with reduction of surgical intervention1. In this case, 20 yo female athlete was referred for evaluation of right shoulder pain and weakness. Pain worse with exercise, with associated 5th digit sporadic numbness. Prior imaging was without adverse findings. Initial examination supported a diagnosis of NTOS. Initial injection utilizing lidocaine to ASM and MSM was completed with improved pain relief, but limited duration. At that time BTX-A injection was recommended.
Injection of BTX-A into the right ASM and MSM was proposed, implemented, and resulted in an overall improvement of symptoms.
Methods: The patient was consented for BTX-A injections and placed in the seated position. With sterile field and process, anatomical landmarks were marked along the right interscalene groove with palpation of both ASM and MSM (Figure 1). 10ml of BTX-A was administered into the ASM and MSM. Both injections with negative aspiration or paresthesia. The patient returned to clinic for post injection evaluation.
Results: On post injection visits, patient reported significant overall reduction of pain with improved function of right upper extremity. The patient reported decreased 5th digit numbness, improved weakness and range of motion, with lasting duration of relief compared to past interventions.
Discussion: We are presenting one of several applications of BTX-A in the setting of NTOS. In a literature review, utilization of BTX-A for chemo denervation as a treatment modality of NTOS has been successful in retrograde case reports1,2,3,4. Procedural standards and suggested volumes to guide the use of BTX-A for NTOS have yet to be established, but documented cases often utilize CT-guided fluoroscopy or EMG monitoring with up to 20ml volumes injected2,3. Few cases have utilized anatomical landmarks with low volumes of BTX-A as shown in this case1,2,3,4. No known correlations of long-term efficacy of BTX-A on reduction of surgical intervention have been studied on a large scale1,3. Future prospective studies are needed to investigate use of BTX-A as a standard of care therapy for NTOS, to establish a standard of procedure, and to investigate whether surgical intervention can ultimately be minimized.