[Thoracoscopic Resection of Schwannoma Using Intraoperative Neurophysiological Monitoring: Report of a Case].

A 28-year-old right-handed woman had been diagnosed with a tumor of 30 mm in a diameter at the right first intercostal space adjacent to brachial nerve plexus. It was incidentally detected by medical checkup examination five years ago. Because the tumor enlarged to 36 mm in five years without any symptoms, thoracoscopic tumor resection was planned for diagnosis. Intraoperative neurophysiological monitoring (IONM) was performed to prevent brachial plexus nerve injury. The tumor was totally removed via thoracoscopic approach without postoperative neurological deficit. Histopathological diagnosis was schwannoma. In order to reduce the risk of neural injury, IONM is useful in thoracoscopic removal of the peripheral nerve tumor.

The value of the cinematic volume rendering technique: magnetic resonance imaging in diagnosing tumors associated with the brachial plexus.

PURPOSE: To examine the diagnostic advantages and clinical application value of the cinematic volume rendering technique (cVRT) when evaluating the relationship between the brachial plexus, peripheral tumor lesions, and blood vessels. MATERIALS AND METHODS: Seventy-nine patients with brachial plexus tumors between November 2012 and July 2022 were enrolled in our study. All patients underwent T1WI, T2WI, three-dimensional short recovery time reversal recovery fast spin-echo imaging (3D-STIR-SPACE), and the T1WI enhancement sequence. In addition, cVRT was used to render and obtain a three-dimensional model that clearly showed the location and tissue structure of the brachial plexus nerves and the tumor in all directions. RESULTS: Seventy-one patients (mean age, 47.1 years; 33 males, 38 females) with tumors around the brachial plexus were included in the study. The brachial plexus nerve, surrounding tumor lesions, and vascular anatomy of all patients were well displayed with cVRT. The tumors of 37 patients manifested as unilateral or bilateral growths along the brachial plexus nerve and were fusiform, spherical, or multiple beaded; seven patients' tumors pushed against the brachial plexus nerve and were circular, lobular, or irregular; sixteen patients' tumors encircled the brachial plexus nerve and were spherical; and eleven patients' tumors infiltrated the brachial plexus nerve and had irregular morphology. The mass has a moderately uniform or uneven signal on T1WI and a high or mixed signal on T2WI. After enhancement, the signal was evenly or unevenly strengthened. CONCLUSIONS: cVRT clearly showed the origin of tumors associated with the brachial plexus and their relationship with the nerves and peripheral blood vessels, providing reliable information for clinical diagnosis and treatment.

Patient demographics, tumor characteristics, and outcomes following surgical treatment of benign and malignant brachial plexus tumors: a systematic review.

BACKGROUND: Various treatment options have been introduced for the management of primary tumors of the brachial plexus (BP), ranging from conservative therapy to wide local excision with/without postoperative chemoradiotherapy. However, no consensus exists regarding optimal treatment strategies based on collated and published data. OBJECTIVE: The aim of this study was to investigate the clinicopathological characteristics and outcome of patients with primary tumors of the BP who underwent surgical treatment. DATA SOURCES: A systematic search of the four main online databases, including Web of Science (WOS), PubMed, Scopus, and Google Scholar, was conducted. STUDY SELECTION: All related articles addressing the clinical outcome and role of surgical interventions for management of primary tumors of the BP. INTERVENTION: Optimal surgical and radiotherapeutic interventions for benign and malignant lesions based on the pathologic characteristics and location of primary BP tumors. RESULTS: A total of 687 patients (693 tumors) with a mean age of 41.7±8.7 years old were evaluated. In total, 629 (90.8%) tumors were benign, and 64 (9.2%) were malignant, with a mean tumor size of 5.4±3.1 cm. The location of the tumor was reported for 639 patients. For these tumors, 444 (69.5%) originated from the supraclavicular region, and 195 (30.5%) were infraclavicular. The trunks were the most common location for tumor involvement, followed by the roots, cords, and terminal branches. Gross total resection was achieved in 432 patients and subtotal resection (STR) was performed in 109 patients. With neurofibromas, STR still resulted in good outcomes. The outcomes following treatment of malignant peripheral nerve sheath tumors were poor regardless of the type of resection. In general, symptoms related to pain and sensory issues resolved rapidly postoperatively. However, the resolution of motor deficits was often incomplete. Local tumor recurrence occurred in 15 (2.2%), patients and distant metastasis was observed in only eight (1.2%) cases. The overall mortality was 21 (3.1%) patients among the study population. LIMITATIONS: The main limitation was the lack of level I and II evidence. CONCLUSIONS: The ideal management strategy for primary BP tumors is complete surgical resection. However, in some cases, particularly for neurofibromas, STR may be preferable to preserve maximal neurological function. The degree of surgical excision (total or subtotal) mainly depends on the pathological characteristics and primary location of the tumor.

Differentiation of Peripheral Nerve Tumors in the Brachial Plexus.

Schwannomas are benign extracranial nerve sheath tumors that can rarely affect the brachial plexus. Due to the relative rarity of these tumors and the complexity of the anatomy of the neck and shoulder, these tumors are a challenging diagnosis for clinicians. We present a case report of a 51-year-old male with a brachial plexus schwannoma definitively treated with surgical resection. It is our hope that this case serves as a reminder to consider schwannomas in the differential diagnosis for infraclavicular tumors.

Isolated Primary Neurolymphomatosis in the Right Brachial Plexus Proven by Partial Nerve Biopsy.

INTRODUCTION: Isolated primary neurolymphomatosis is a rare manifestation of lymphoma, which is challenging to diagnose as there is only involvement of the nervous system, and nerve biopsy is not frequently pursued due to the high risk of irreversible complications. CASE REPORT: We present a case of isolated primary neurolymphomatosis of diffuse large B-cell lymphoma restricted to only the right brachial plexus and right axillary nerve. The clinical course has been indolent for several years. The initial examination, including MRI and the cerebrospinal fluid study, did not yield any evidence of malignancy. Eventually, due to the patient's symptom progression and the follow-up imaging findings, we conducted a partial nerve biopsy of the brachial plexus to confirm the malignancy. His neurological symptoms did not further deteriorate post-biopsy. CONCLUSION: Isolated primary neurolymphomatosis with an indolent course is rare and challenging to diagnose. Serial MRI and fluorodeoxyglucose-positron emission tomography reveal clues for tumor involvement. Partial nerve biopsy or targeted fascicular nerve biopsy could be an alternative for achieving a pathologic diagnosis.

Natural History of Brachial Plexus, Peripheral Nerve, and Spinal Schwannomas.

BACKGROUND: Management of sporadic schwannomas is often dictated by a patient's clinical presentation and the tumor's behavior. For patients who are managed nonsurgically, there are little data available about the expected natural history. OBJECTIVE: To evaluate the natural history and growth patterns of extracranial schwannomas including tumors of the distal peripheral nerves, spine, and brachial plexus. METHODS: A retrospective review was performed to identify patients with nonsyndromic extracranial schwannomas at a single tertiary care institution diagnosed between 2002 and 2019. Patient data and tumor characteristics including volume were recorded. RESULTS: Two hundred twenty-seven patients were identified (mean age 51 years, 42% male, average of 27.8-month follow-up). Tumor location was distal peripheral nerve in 82, brachial plexus in 36, and paraspinal in 109. At the time of diagnosis, peripheral lesions were significantly larger than spinal (59 m 3 vs 13 cm 3 ) and brachial plexus lesions (15 cm 3 ). Distinct growth patterns were seen with both distal peripheral nerve and spinal lesions; 34/82 peripheral nerve lesions had fast growth (ß = 0.176%/day), and 48 had slow growth (ß = 0.021%/day; P < .01). Spinal schwannomas similarly had 30 fast-growing (ß = 0.229%/day), 16 moderate-growing (ß = 0.071%/day), and 63 slow-growing (ß = 0.022%/day; P = .03) subtypes. The brachial plexus had relatively homogeneous growth patterns (ß = 0.065%/day). Females had 2.9 times greater odds of having the fast-growing subtype. CONCLUSION: Distinct growth patterns were seen in extracranial sporadic schwannomas based on tumor location and patient demographics. Fast (>80% volume change per year) vs slow (5%-10% per year) tumor growth can often be ascertained within 2 follow-up images. Awareness of these patterns might have implications for patient counseling and therapeutic decision-making.

An Uncommon, Extensive Involvement of Hydatid Cyst-Cervical Spine to Brachial Plexus.

Introduction: Hydatid cyst usually involves liver and lung. But it has been reported in uncommon locations like the spine and brain. There are few reports of cervical spine to brachial plexus. This report is about such extensively involved hydatid cyst management. Case Report: A 32-year-old male had complaints of neck pain, left-hand weakness, and atrophy. MRI of cervical spine and thorax revealed a multicystic lesion involving the cervical spine, vertebrae, brachial plexus, and lung apex. The lesion was removed in two stages. Discussion: Due to scarcity of literature, dense adhesions with dura and surroundings, risk of rupture, anaphylactic shock, and its management require proper planning. Excision of cervical, followed by plexus lesion, might help. Long-term use of albendazole prevents recurrence as suggested by other reports. Conclusion: Extensive spinal hydatid cyst is exceptionally challenging. These behave like malignant lesions. To get the best results, surgical planning is as essential as medical management.

Axial T2-DRIVE MRI myelography is highly accurate in diagnosing preganglionic traumatic brachial plexus injuries: why pseudomeningoceles should not be used as a primary diagnostic sign.

AIM: To evaluate the accuracy of brachial plexus magnetic resonance imaging (MRI) utilising the three-dimensional (3D)-T2-turbo spin echo (TSE) with 90° flip-back pulse ("DRIVE") myelography in detecting nerve root avulsions in patients with traumatic brachial plexus injuries. MATERIALS AND METHODS: A prospective study of 24 patients planned for brachial plexus reconstructive surgery following trauma from April 2019 to October 2021. Preoperative 1.5 T MRI of the brachial plexus was performed utilising axial T2-DRIVE, looking for signs of avulsions (absent dural rootlets, pauci-rootlet appearance and thickened rootlets; the presence of pseudomeningoceles was noted only as an ancillary sign). Comparison against the reference standard of extra-dural brachial plexus exploration was performed. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. RESULTS: Eighteen patients had at least one root avulsion at surgery, five showed isolated post-ganglionic injuries, and one had normal brachial plexus exploration. Thirty-nine avulsed roots were found at surgery (out of 108 explored in 24 patients). Preoperative MRI identified the specific avulsed roots accurately in each patient. Two false-positive diagnoses of C5 and C6 avulsions were made in one patient. On MRI, absence of the rootlets was seen in 73.2% (n=30) of avulsions, pauci-rootlet appearance in 24.4% (n=10) and thickening of the rootlets in 2.4% (n=1). Pseudomeningoceles were found only in 68.3% (n=28) of avulsions. The overall sensitivity, specificity, PPV, NPV, and accuracy of MRI were 100%, 97.1%, 95.1%, 100% and 98.1%, respectively. CONCLUSION: 3D-T2-DRIVE is highly accurate in evaluating pre-ganglionic traumatic brachial plexus injuries. Pseudomeningoceles can be considered an ancillary feature of avulsion given the clarity of rootlet visualisation by this sequence.

Diagnostic performance of diffusion-weighted MR neurography as an adjunct to conventional MRI for the assessment of brachial plexus pathology.

OBJECTIVE: To investigate the diagnostic performance of diffusion-weighted (DW) MR neurography as an adjunct to conventional MRI for the assessment of brachial plexus pathology. METHODS: DW MR neurography scans (short tau inversion recovery fat suppression and b-value of 800 s/mm2) of 15 consecutive patients with and 45 randomly selected patients without brachial plexus abnormalities were independently and blindly reviewed by a 5th year radiology resident, a junior neuroradiologist, and a senior neuroradiologist. RESULTS: Median interpretation times ranged between 20 and 30 s. Interobserver agreement was substantial (κ coefficients of 0.715-0.739). For the 5th year radiology resident, sensitivity was 53.3% (95% CI, 30.1-75.2%) and specificity was 100% (95% CI, 92.1-100%). For the junior neuroradiologist, sensitivity was 66.7% (95% CI, 41.7-84.8%) and specificity was 100% (95% CI, 92.1-100%). For the senior neuroradiologist, sensitivity was 73.3% (95% CI, 48.1-89.1%) and specificity was 95.6% (95% CI, 85.2-98.8%). Traumatic injury, metastases, radiation-induced plexopathy, schwannoma, and inflammatory process of unknown cause could be detected by the majority of readers (100% detection rate for each disease entity by at least two readers). Neuralgic amyotrophy, iatrogenic injury after first rib resection, and cervical disc herniation causing root compression were not detected by the majority of readers (0% detection rate for each disease entity by at least two readers). CONCLUSION: DW MR neurography may be a useful adjunct when assessing for brachial plexus abnormalities, because interpretation time is relatively short and the majority of abnormalities can be detected. KEY POINTS: • DW MR neurography interpretation time of the brachial plexus is relatively short (median interpretation times of 20 to 30 s). • Interobserver agreement between three readers with different levels of experience is substantial (κ coefficients of 0.715 to 0.739). • DW MR neurography can detect brachial plexus abnormalities with moderate sensitivity (53.3 to 73.3%) and high specificity (95.6 to 100%).

Stereotactic Body Radiation Therapy for Apical Lung Tumors: Dosimetric Analysis of the Brachial Plexus and Preliminary Clinical Outcomes.

PURPOSE: Dosimetric constraints of the brachial plexus have not yet been well-established for patients undergoing stereotactic body radiation therapy (SBRT). This study evaluated long-term experience with the treatment of early-stage apical lung tumors with SBRT and reports on dosimetric correlates of outcome. METHODS AND MATERIALS: Between 2009 and 2018, a total of 78 consecutive patients with 81 apical lung tumors underwent SBRT for T1-3N0 non-small cell lung cancer. Apical tumors were those with tumor epicenter superior to the aortic arch. The brachial plexus (BP) was anatomically contoured according to the Radiation Therapy Oncology Group atlas. Patient medical records were reviewed retrospectively to determine incidence of brachial plexus injury (BPI) and a normal tissue complication probability model was applied to the dosimetric data. RESULTS: Five patients (6.4%) reported neuropathic symptoms consistent with BPI and occurred a median 11.9 months after treatment (range, 5.2-28.1 months). Most common dose and fractionation in those developing BPI were 50 Gy in 5 fractions (4 patients). Symptoms consisted of pain in 2 patients (40.0%), numbness in the hand or axilla in 4 patients (80.0%), and ipsilateral hand weakness in 1 patient (20.0%). In the overall cohort the median BP Dmax (EQD23 Gy) was 5.13 Gy (range, 0.18-217.2 Gy) and in patients with BPI the median BP Dmax (EQD23 Gy) was 32.14 Gy (range, 13.4-99.9 Gy). The normal tissue complication probability model gave good fit with an area under the curve of 0.75 (odds ratio, 7.3; 95% confidence interval, 0.8-68.3) for BP Dmax (EQD23 Gy) threshold of 20 Gy. CONCLUSIONS: Significant variation exists in the dose delivered to the brachial plexus for patients treated by SBRT for apical lung tumors. The incidence of neuropathic symptoms in the post-SBRT setting was appreciable and prospective clinical correlation with dosimetric information should be used to develop evidence-based dose constraints.

The effect of epinephrine on the perfusion index during ultrasound-guided supraclavicular brachial plexus block: a randomized controlled trial.

The perfusion index (PI) is an objective tool used to assess a successful nerve block. Epinephrine is a widely used adjuvant to local anesthetics, and it may affect PI values because of the vasoconstrictive property. The aim of this study was to investigate the influence of epinephrine on PI as an indicator of a successful block in ultrasound-guided supraclavicular brachial plexus block (SCBPB). In this randomized controlled trial, 82 adult patients underwent upper limb surgery under SCBPB were recruited between July 2018 and March 2019 in a single tertiary care center. Participants were randomly assigned to one of two groups: non-epinephrine group (n = 41) or epinephrine group (5 mcg ml-1, n = 41). The primary outcome was the comparison of the "PI ratio 10," which was defined as the ratio of the PI 10 to the baseline. Receiver operating characteristic (ROC) curves were constructed to determine the accuracy of the PI in predicting the block success at each time interval. The PI ratio 10 was 2.7 (1.9-4.0) in non-epinephrine group and 3.3 (2.2-4.4) in epinephrine group (median difference: 0.4; 95% confidence interval [CI] - 1.1 to 0.2; P = 0.207). The ROC curves compared without group identification were not significantly different over time. The cut-off value for the PI and PI ratio at 5 min (PI ratio 5) were 7.7 (area under the ROC [AUROC]: 0.89, 95% CI 0.83-0.94) and 1.6 (AUROC: 0.94, 95% CI 0.90-0.98), respectively. The perineural epinephrine did not affect the PI following a SCBPB. The PI ratio 5 > 1.6 might be considered as a relatively accurate predictor of a successful SCBPB.Trial registration: This study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr. CriS No. KCT0003006).

Diffuse Neuritis Ossificans of the Brachial Plexus: Case Report and Review of the Literature.

BACKGROUND: Neuritis ossificans (intraneural heterotopic ossification) is a rare disorder described as heterotopic ossification of a nerve. We describe the presentation and management of the first reported case of neuritis ossificans with diffuse brachial plexus involvement and review the literature. CASE DESCRIPTION: A 35-year-old man presented to our clinic for evaluation of right upper extremity weakness without history of trauma. He had significant, debilitating pain and magnetic resonance imaging demonstrated a complex contrast-enhancing mass with significant associated edema. Positron emission tomography demonstrated a 18F-fluorodeoxyglucose avid lesion within the brachial plexus that was confirmed by biopsy to be neuritis ossificans. The patient was treated with indomethacin and had clinical and radiologic improvement. CONCLUSIONS: We present the only case of diffuse, brachial plexus neuritis ossificans. Given the challenges of resecting neuritis ossificans in this region, we believe medical management for complex brachial plexus lesions should be considered first, unless the sequela of the disease is sufficiently prolonged or there is concern for permanent neurovascular compromise.

Brachial plexus schwannoma mimicking advanced breast carcinoma.

BACKGROUND: Schwannoma is an extremely rare benign tumour of the peripheral nervous system; its association with breast cancer is sporadic, and its association with the brachial plexus is extremely rare. CASE DESCRIPTION: The authors report a case of a patient with breast cancer associated with nodulation in the left supraclavicular fossa, and due to the clinical and radiological features, it was considered metastatic lymph node disease. The patient underwent neoadjuvant chemotherapy, with partial response of the breast. Surgical treatment included resection of the supraclavicular nodule, which was found to be a supraclavicular fossa schwannoma. The correct diagnosis, influences the radiotherapeutic planning. The unusual presentation led to diagnostic confusion in the present case, a fact that changed the breast treatment. CONCLUSION: The best of our knowledge it is the third description of brachial plexus schwannoma associated with breast cancer and the first with a synchronous association. The knowledge of this pathology and its potential to alter treatment justify the reporting of the present case.

Rare Primary Embryonal Carcinoma in the Brachial Plexus: A Case Report and Literature Review.

BACKGROUND AND IMPORTANCE: Primary tumors of the brachial plexus are rare. Most are benign and characterized as Schwannoma and neurofibroma, whereas malignant peripheral nerve sheath tumors are less common. Here, we report a rare case of primary embryonal carcinoma in the brachial plexus. CLINICAL PRESENTATION: A 17-yr-old male presented with a 3-mo history of a mass growing in the left supraclavicular region over the middle part of the clavicle. Magnetic resonance imaging revealed a well-defined mass (diameter 2.5 cm) straddling the brachial plexus. After surgical resection, and the mass was histologically confirmed to be an embryonal carcinoma. CONCLUSION: Primary embryonal carcinoma in the brachial plexus has not been reported previously. This case highlights the importance of considering the possibility that some primary brachial plexus tumors may be malignant and should be treated promptly.

Characteristics of metastatic brachial plexopathy in patients with breast cancer.

PURPOSE: Brachial plexopathy in cancer patients is a rare but significant complication that causes pain and disability of the upper extremities. Clinical features of breast cancer patients with metastatic brachial plexopathy (MBP) have not been studied. We aimed to investigate the characteristics of MBP in breast cancer patients. METHODS: We retrospectively reviewed medical records of patients with breast cancer with MBP who visited Asan Medical Center from 2000 to 2016; we enrolled 44 patients. We comprehensively reviewed the characteristics, range of metastatic lymph nodes, initial symptoms, location, and severity of brachial plexus injury by electrodiagnostic study, radiologic findings, and associated complications. RESULTS: The mean age of patients with MBP was 51.9 ± 9.3 years; 25% were diagnosed with stage IV breast cancer at initial diagnosis. Weakness was the most common initial symptom of MBP (52.3%). Most patients showed limitation of shoulder range of motion and pain; 66% of patients exhibited malignant lymphedema. Forty-one patients were evaluated by electromyography; upper nerve trunk involvement (22.0%) was more frequent than lower nerve trunk involvement (9.8%). Nineteen patients underwent brachial plexus MRI, and supraclavicular area (SCA) metastasis was most frequent (57.9%). Sixteen patients were examined by both brachial plexus MRI and electromyography; patients with SCA metastasis exhibited significantly more frequent malignant lymphedema (p = 0.019) and upper nerve trunk involvement (p = 0.035), compared with patients with non-SCA metastasis. CONCLUSIONS: Our study revealed clinical features of MBP in breast cancer patients. Additional diagnostic evaluation focused on metastasis or aggravated metastatic tumor is needed when breast cancer patients are diagnosed with brachial plexopathy.

[Suspected traumatic posterior shoulder luxation]. / Een vermeende traumatische posterieure schouderluxatie.

BACKGROUND An obstetric brachial plexus lesion arises during childbirth as a consequence of excessive lateral traction of the neonate's head during shoulder dystocia. A small number of patients do not experience spontaneous recovery and secondary glenohumeral deformities can arise due to rotator cuff imbalance. CASE DESCRIPTION A 34-year-old man of Syrian descent with a history of a conservatively treated right-sided obstetric brachial plexus lesion went to the accident and emergency department (A and E) with acute pain in the right shoulder. Additional X-ray diagnostics suggested a posterior shoulder luxation, but attempts to relocate the glenohumeral joint in A and E failed. An additional CT scan of the shoulders revealed a severe right-sided dysplasia of the glenohumeral joint, with severe retroversion and posterior luxation of a rotated humeral head. After 3 weeks of relative rest through use of a sling and pain relief with an NSAID the pain had diminished and the patient had resumed his daily activities. CONCLUSION Posterior shoulder luxation can occur as a complication of obstetric brachial plexus lesion. Closed reduction is not of any use in these cases. The expertise of a specialized multidisciplinary team is indispensable for providing a patient with obstetric brachial plexus lesion with the best advice on treatment.

Exposure of the brachial plexus in complex revisions to reverse total shoulder arthroplasty.

BACKGROUND: Excision of extensive scar tissue (EEST) may be required in certain cases of revision reverse total shoulder arthroplasty (RTSA). Neurovascular structures are at a higher risk of iatrogenic direct injury in these cases. We describe a technique to expose and protect the musculocutaneous and axillary nerves in a series of revision RTSA cases that required EEST. METHODS: Between 2004 and 2013, 83 revision RTSA procedures were identified in our database. Of these, 18 cases (22%) who underwent concomitant nerve exploration for EEST preventing glenoid exposure, preventing reduction of the humeral component, or causing instability of the implanted RTSA, were included. All patients were observed for a minimum of two  years or until reoperation. Patient-reported outcome scores (PROMs), range of motion (ROM), and complication rates were analyzed. RESULTS: Patients had significant pain relief and improvement in PROMs post-operatively. Two patients (11%) required another revision surgery because of infection (one patient with glenoid loosening; one patient with stem loosening). Two patients (11%) had instability successfully managed with closed reduction. Two patients (11%) had a clinically evident post-operative nerve injury. Both cases were neurapraxias (1 partial brachial plexopathy and 1 partial isolated axillary nerve injury) and experienced complete neurologic recovery at last follow-up. CONCLUSIONS: Complete permanent nerve injuries resulting from direct surgical trauma during revision RTSA requiring EEST can be avoided using the technique presented here. Despite proper exposition of the nerves, partial temporary neurapraxic injuries may occur. Patients who underwent this procedure experienced significant improvements in shoulder pain and function with complication rates consistent to those previously reported in revision RTSA.

Contralateral C7 transfer to lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck for total brachial plexus root avulsion: a cadaveric study.

BACKGROUND: Restoration of hand function after total brachial plexus root avulsion (tBPRA) is a difficult problem in surgical management. A new modified approach in repairing tBPRA is to use a subcutaneous tunnel across the anterior surface of the chest and neck, and then transfer the contralateral C7 root (cC7) to the lower trunk. However, the anatomical details of this method have not yet been fully described and assessed. The objective of this study was to quantitatively describe the nerve transfer using a cadaveric surgical simulation. MATERIALS AND METHODS: Brachial plexuses were dissected from 12 adult cadavers, producing 24 sides of brachial plexuses for nerve transfer experiments. We performed simulated cC7 transfers to the lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck. Measurements of the nerves were made and transfers quantitatively documented. RESULTS: With the affected shoulder and arm in a neutral position, cC7 and C8-T1 could be sutured directly together in 75% of the cadavers. A nerve graft length of 4.6 ± 1.18 cm was needed to bridge the gap in the remaining cadavers. For cadavers where distal cC7 was directly connected with the lower trunk, 54.17% could be sutured, and an average nerve graft length of 3.9 cm was needed in the remains. CONCLUSIONS: For surgical management of total tBPRA, transfer of the cC7 nerve to the C8-T1 or lower trunk via a subcutaneous tunnel across the chest and neck will likely be superior to a conventional cC7 root transfer in the clinic. This approach shortens the nerve graft needed and nerve regeneration distance, decreases the number of neurorrhaphy sites, and makes full use of the donor nerves, which may benefit hand flexion restoration.