Can surface electromyography improve surgery planning? Electromyographic assessment and intraoperative verification of the nerve bundle entry point location of the gracilis muscle

• Published in: Journal of electromyography and kinesiology 2016-06, Vol.28, p.1-6
• Main Authors: Romaniszyn, Michal, Walega, Piotr, Nowakowski, Michal, Nowak, Wojciech
• Format: Article
• Language: English
• Subjects: Adult; Aged; Clinical Decision-Making - methods; Dynamic graciloplasty; Electrode arrays; Electromyography - methods; Electromyography - standards; Female; Gracilis muscle; Gracilis Muscle - innervation; Gracilis Muscle - physiology; Gracilis Muscle - surgery; Humans; Innervation; Intraoperative Care - methods; Intraoperative Care - standards; Male; Middle Aged; Muscle Contraction - physiology; Muscle, Skeletal - innervation; Muscle, Skeletal - physiology; Muscle, Skeletal - surgery; Physical Medicine and Rehabilitation; Surface electromyography
• ISSN: 1050-6411; 1873-5711
• DOI: 10.1016/j.jelekin.2016.02.006

Abstract Purpose To verify the precision of surface electromyography (sEMG) in locating the innervation zone of the gracilis muscle, by comparing the location of the IZ estimated by means of sEMG with in vivo location of the nerve bundle entry point in patients before graciloplasty procedure due to fecal incontinence. Methods Nine patients who qualified for the graciloplasty procedure underwent sEMG on both gracilis muscle before their operations. During surgery the nerve bundle was identified by means of electrical stimulation. The distance between the proximal attachment and the nerve entry point into the muscle’s body was measured. Both measurements (sEMG and in vivo identification) were compared for each subject. Results On average, the IZ was located 65,5 mm from the proximal attachment. The mean difference in location of the innervation zones in each individual was 10 mm ±9,7 mm, maximal - 30 mm, the difference being statistically significant (p=0,017). It was intraoperatively confirmed, that the nerve entered the muscle an average of 62 mm from the proximal attachment. The largest difference between the EMG IZ estimation and nerve bundle entry point was 5 mm (mean difference 2,8 mm, p=0,767). Conclusion Preoperative surface electromyography of both gracilis muscles is a safe, precise and reliable method of assessing the location of the innervation zones of the gracilis muscles. The asymmetry of the IZ location in left and right muscles may be important in context of technical aspects of the graciloplasty procedure.