Identification of long thoracic nerve on high-resolution 3T MRI

Serratus anterior plane block with ultrasound-guided hydrodissection for lateral thoracic pain caused by long thoracic nerve neuropathy - A case report

BACKGROUND

Long thoracic nerve (LTN) neuropathy occasionally occurs in young people who engage in various sports. It may have a traumatic or non-traumatic etiology. The landmark manifestation of LTN neuropathy is scapular winging; however, it can also occur without scapular winging and specific magnetic resonance imaging findings.

CASE

An 18-year-old male complained of right-sided lateral chest pain for 7 months. He was treated with medication, trigger point injection, and physical therapy but showed no improvement. Electromyelogram findings suggested LTN neuropathy in the right lateral chest. We performed a serratus anterior (SA) plane block with ultrasound (US)-guided hydrodissection and achieved pain relief.

CONCLUSIONS

We report the successful treatment of LTN neuropathy with an SA plane block and US-guided hydrodissection.

Neurolysis of the distal segment of the long thoracic nerve for the treatment of scapular winging due to serratus anterior palsy: a continuous series of 73 cases

BACKGROUND

Serratus anterior (SA) palsy following mechanical injury to the long thoracic nerve (LTN) is the most common cause of scapular winging. This study aimed to identify the factors influencing the outcome of neurolysis of the distal segment of the LTN. We hypothesized that poor results are due to duration before surgery and to persistent scapulothoracic dysfunction.

METHODS

A retrospective study was conducted. The inclusion criteria were partial or complete isolated noniatrogenic SA paralysis of at least 4-month duration with preoperative electrophysiologic assessment confirming the neurogenic origin without signs of reinnervation.

RESULTS

Seventy-three patients were assessed at 45 days, 6 months, and 24 months after neurolysis of the distal segment of the LTN. At the last follow-up, improvement was excellent in 38 (52%), good in 22 cases (30%), moderate in 6 (8%), and poor in 7 (10%). No patient showed deterioration in outcomes since the beginning of follow-up. Scapular winging was no longer present in 46 cases (63%), while it was minimal in 23 (31.5%). In 4 cases (5.5%), winging was similar to the preoperative condition.

DISCUSSION

The best outcomes occurred in patients who presented without compensatory muscle pain and who were treated within 12 months of paralysis. Beyond this time frame, neurolysis can still provide useful functional improvement and avoid palliative surgery.

CONCLUSION

Neurolysis of the distal segment of the LTN is a safe and reliable procedure. This technique allows treatment of SA muscle palsy and corrects scapular winging with excellent or good outcomes in 82% of cases.

Ultrasonographic anatomy of the long thoracic nerve: A reappraisal using high frequency (24-MHz) probe

PURPOSE

The purpose of this study was to analyze the potential of ultrasound with a high frequency probe (24-MHz) in the assessment of the long thoracic nerve (LTN) and describe ultrasonographic landmarks that can be used for standardization.

MATERIAL AND METHODS

Ultrasonography analysis of the LTN was done on 2 LTNs in a cadaver specimen and then on 30 LTNs in 15 healthy volunteers (12 men, 3 women; mean age, 28.8±3.8 [SD] years; age range: 24-39 years) by two independent radiologists (R1 and R2) using a 24-MHz probe. Interrater agreement was assessed using Kappa test (K) and intraclass correlation coefficient (ICC).

RESULTS

In the cadaver, dissection confirmed that the India ink was injected near the LTN in the middle scalene muscle. In volunteers, visibility of the LTN above the clavicle was highly reproducible for the branches arising from C5 (R1: 87% [26/30]; R2: 90% [27/30]; K=0.83) and from C6 (R1: 100% [30/30]; R2: 97% [29/30]; K=0.94). Where the nerve emerged from the middle scalene muscle, the mean diameter was 0.85±0.24 (SD) mm (range: 0.4-1.6mm) for R1 and 0.9±0.23 (SD) mm (range: 0.4-1.7mm) for R2 (ICC: 0.96; 95% CI: 0.92-0.98%). Along the thoracic wall, where LTN run along the lateral thoracic artery, the mean diameter was 0.83±0.19 (SD) mm (range: 0.5-1.27mm) for R1 and 0.89±0.21 (SD) mm (range: 0.6-1.2mm) for R2 (ICC: 0.86; 95% CI: 0.72-0.93%).

CONCLUSION

The LTN can be analyzed with ultrasound using high-frequency probe by using the C5 and C6 roots, the middle scalene muscle above the clavicle and the lateral thoracic artery on the chest wall as landmarks.