A modified, less invasive posterior subscapular approach to the brachial plexus: case report and technical note

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The traditional posterior subscapular approach offers excellent exposure of the lower brachial plexus and has been successfully used in patients with recurrent thoracic outlet syndrome after an anterior operation, brachial plexus tumors involving the proximal roots, and postirradiation brachial plexopathy, among others. However, this approach also carries some morbidity, mostly related to the extensive muscle dissection of the trapezius, rhomboids, and levator scapulae. In this article, the authors present the surgical technique and video illustration of a modified, less invasive posterior subscapular approach, using a small, self-retaining retractor and only a partial trapezius and rhomboid minor muscle dissection. This approach is likely to result in decreased postoperative morbidity and a shorter hospital stay.

ABBREVIATIONSTOS = thoracic outlet syndrome.

The traditional posterior subscapular approach offers excellent exposure of the lower brachial plexus and has been successfully used in patients with recurrent thoracic outlet syndrome after an anterior operation, brachial plexus tumors involving the proximal roots, and postirradiation brachial plexopathy, among others. However, this approach also carries some morbidity, mostly related to the extensive muscle dissection of the trapezius, rhomboids, and levator scapulae. In this article, the authors present the surgical technique and video illustration of a modified, less invasive posterior subscapular approach, using a small, self-retaining retractor and only a partial trapezius and rhomboid minor muscle dissection. This approach is likely to result in decreased postoperative morbidity and a shorter hospital stay.

The posterior subscapular approach to the brachial plexus is safe and effective.6 Its indications include: thoracic outlet syndrome (TOS) and recurrent TOS,7 brachial plexus tumors involving the proximal roots, postirradiation brachial plexopathy, and proximal brachial plexus palsy.3 The posterior approach is especially helpful for brachial plexus access in patients with previous irradiation to the neck or anterior chest wall, previous anterior neck surgery, or morbid obesity.3 The advantages of this approach include ease of exposure, exposure of the intraforaminal portion of spinal nerves,4 and protection of important vasculature. The major drawback of the posterior approach is the morbidity associated with extensive muscle dissection.3 We describe a modified, less invasive posterior subscapular approach to the lower brachial plexus.

Operative Technique

The patient is placed prone, with adequate padding for all pressure points. The operative side is slightly elevated, with additional padding underneath the clavicle to abduct the shoulder. The arms are padded and tucked to the side. Fluoroscopic guidance is used mark the projection of the posterior aspect of the first rib on the skin (Fig. 1). A 6-cm skin incision is made approximately halfway between the spinous processes and the medial border of the scapula, centered on the first rib skin marking (Fig. 2). The trapezius muscle layers are divided parallel to the orientation of the muscle fibers. The rhomboid minor muscle is divided similarly in the depth, and the T-1 costotransverse joint is encountered. This is confirmed by palpation as well as fluoroscopy. (At this level, only the rhomboid minor needs to be dissected. The rhomboid major and the levator scapulae are caudal and cranial to this exposure, respectively, and therefore are not affected.) At this time, self-retaining retractors (Trimline; Medtronic) are positioned to maintain the exposure, with a shorter blade toward the midline and possibly a longer blade laterally, over the first rib and under the scapula (Fig. 3). The lateral blade can also be rested against the soft tissues, if extensive lateral exposure is not necessary.

FIG. 1.
FIG. 1.

Images showing the first rib fluoroscopic projection and the corresponding mark on the skin.

FIG. 2.
FIG. 2.

Photograph showing the skin incision centered on the first rib marking, between midline and the medial border of the scapula in a cadaver.

FIG. 3.
FIG. 3.

Photograph showing cadaveric dissection exposing the first transverse process and rib. The exposure is maintained using self-retaining retractors.

The T-1 transverse process is removed with a high-speed drill or Leksell rongeur, thus exposing the head of the first rib. An elongated C-7 transverse process can be removed in a similar fashion, if necessary. The soft tissues are then carefully detached from the first rib with a periosteal elevator (Fig. 4), and the rib is removed in a piecemeal fashion, starting medially with the rib head. The lateral extent of the resection of the first rib depends on the underlying pathology, but the resection can be extended all the way to the anterior aspect of the first rib. This allows for exposure of the C-8 and T-1 spinal nerves, as well as the lower trunk (Fig. 5). The exposure can be extended cranially to expose the C-7 spinal nerve and middle trunk, or caudally, by removing the second or even third rib. If foraminal exposure is necessary, it can be easily achieved by removing the facet joints and ipsilateral lamina at the level of interest. The wound is closed in anatomical layers. The muscles typically revert to their original position without a need for reapproximation (Fig. 6).

FIG. 4.
FIG. 4.

Fluoroscopic image of the cadaveric dissection illustrating the scapula retraction by the lateral, longer blade of the self-retaining retractor. This exposure allows for extensive dissection and resection of the first rib.

FIG. 5.
FIG. 5.

Photograph of cadaveric dissection illustrating the exposure of the C-8 and T-1 spinal nerves and the lower trunk (LT) of the brachial plexus.

FIG. 6.
FIG. 6.

Photograph showing cadaveric dissection before closure. The skin incision is only 6 cm long.

Cadaveric Study

We performed this approach on 3 cadavers with no associated pathological entities or gross anatomical abnormalities. The dissection and first rib removal were extended as far anterior as technically feasible. The C-8 and T-1 spinal nerves, as well as the lower trunk, were exposed without difficulty. Preoperative and postoperative CT scans were obtained to determine the extent of the first rib resection (Fig. 7).

FIG. 7.
FIG. 7.

A 3D CT reconstruction of the cadaveric specimen after dissection, illustrating the extent of the first rib resection.

Case Report

History and Examination

We describe the case of a 49-year-old woman with a long history of neurogenic TOS who underwent a transaxillary first rib resection 1 year prior to presentation. The patient reported no improvement after this operation and noted progressively increasing pain over the past year radiating from the neck and trapezius muscle down the arm and into the last 3 digits. Her arm visual analog scale score was 10/10 and her Oswestry Disability Index was 74. On physical examination, she had mild right abductor digiti minimi and abductor pollicis brevis weakness (MRC 4/5).

Imaging Studies

Imaging studies revealed a remnant of the first rib and rib head (Fig. 8). An electromyogram and a nerve conduction study confirmed chronic denervation of the T-1 more than the C-8 dermatomes. After a discussion of risks, benefits, alternatives, and expectations, the patient elected to undergo a modified, less invasive posterior subscapular approach for surgical removal of the first rib remnant and exploration of the C-8 and T-1 spinal nerves (Video 1).

VIDEO 1. The modified, less invasive posterior subscapular approach for exposure of the lower brachial plexus in a patient with TOS and previous transaxillary first rib resection. Copyright Gabriel C. Tender. Published with permission. Click here to view.

FIG. 8.
FIG. 8.

Case 1. Coronal (left) and axial (right) MRI studies of the brachial plexus prior to the modified posterior subscapular approach. The asterisk marks the first rib remnant.

Preparations were made to be able to convert to a classic subscapular approach if necessary.

Operation and Postoperative Course

The operating time was 120 minutes and the estimated blood loss was less than 50 ml. There were no complications. The patient tolerated the procedure well and was discharged the following morning. At the 3-month followup visit, her visual analog scale score for arm pain was 4/10 and the Oswestry Disability Index was 22. The incision was well healed and there was no associated muscle atrophy or winged scapula. The patient reported subjective improvement in hand strength, although by the time of examination there was still a persistent slight weakness in the same muscles.

Discussion

The posterior subscapular approach has proven to be safe and effective. The original version of this approach was used for patients with tuberculosis pulmonary lesions, as described by Clagett.2 The surgical technique was partially modified and adapted to access the lower brachial plexus lesions, and a first case series was published in 1978 by Kline et al.5 The posterior subscapular approach offered the advantage, among others, of exposing the foraminal part of the spinal nerves in proximal lesions.4 A larger series of 102 patients was then published in 1993, emphasizing the variety of pathological entities that can be accessed using this surgical technique.3 Complications in this series included winged scapula, cervical spine instability when more than 2 facets were removed, pleural tears, pneumo- or hemothorax, phrenic nerve injury palsy, or new or further damage to the brachial plexus. According to the senior author (D.G.K.), the average estimated blood loss was between 600 and 750 ml, and the average length of hospitalization was 5–6 days (longer in patients with severe trauma or large tumors). The skin incision, extending roughly from just below the tip of the scapula to the cranial-most aspect of the trapezius muscle in the paraspinal region, was between 30 and 40 cm in length.

The posterior subscapular approach offers excellent exposure of the proximal brachial plexus (particularly the lower elements), as well as lesions extending into the chest.1 However, it is usually considered a second (or third) operative choice, due to the morbidity associated with the exposure, such as muscle atrophy and winged scapula. Moreover, the arm is typically placed on a Mayo stand that can be lowered during the surgery, to facilitate the lateral retraction of scapula.

The modified, less invasive approach takes advantage of the availability of a strong yet relatively small self-retaining retractor, such as Trimline or analogs. These retractors are typically very familiar to surgeons from their use in the anterior cervical approaches. After exposure of the first transverse process, the self-retaining retractor can be used to push the scapula laterally with sufficient force to allow for exposure of the first rib (and second or third rib, if necessary). Moreover, using a longer blade laterally, the first rib curvature can be followed all the way to its turn, thus providing safety for rib isolation and resection. In muscular patients, in whom scapular retraction may be difficult, the ipsilateral arm can be placed on a padded Mayo stand, similar to the traditional technique.

Given the limited muscle dissection and easy closure, the morbidity of the posterior subscapular approach seems to be decreased. Therefore, this approach may become a first option in patients with TOS or tumors involving the lower proximal plexus. However, larger tumors, especially those involving the mediastinum and compressing the lung, and severe cases of irradiation plexitis or very scarred plexus after anterior approaches, may need the more classic extensive approach, and almost always require more than the first rib removed.

Conclusions

The modified, less invasive posterior subscapular approach is technically simple and appears to be associated with less morbidity than the traditional approach. Potential advantages include reduced blood loss, less postoperative pain, decreased length of stay, and faster return to function. Surgical indications are similar to the traditional posterior subscapular approach. However, due to the decreased morbidity, the modified, less invasive approach may become a surgical option of choice in patients with lower brachial plexus pathology.

References

  • 1

    Biggs MT: Posterior subscapular approach for specific brachial plexus lesions. J Clin Neurosci 8:3403422001

  • 2

    Clagett OT: Research and prosearch. J Thorac Cardiovasc Surg 44:1531661962

  • 3

    Dubuisson ASKline DGWeinshel SS: Posterior subscapular approach to the brachial plexus. Report of 102 patients. J Neurosurg 79:3193301993

  • 4

    Kline DGDonner TRHappel LSmith BRichter HP: Intraforaminal repair of plexus spinal nerves by a posterior approach: an experimental study. J Neurosurg 76:4594701992

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5

    Kline DGKott JBarnes GBryant L: Exploration of selected brachial plexus lesions by the posterior subscapular approach. J Neurosurg 49:8728801978

  • 6

    Tender GCKline DG: Posterior subscapular approach to the brachial plexus. Neurosurgery 57:4 Suppl3773812005

  • 7

    Tender GCThomas AJThomas NKline DG: Gilliatt-Sumner hand revisited: a 25-year experience. Neurosurgery 55:8838902004

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Tender, Kline. Acquisition of data: Tender, Crutcher. Analysis and interpretation of data: Tender, Kline. Drafting the article: Tender, Crutcher. Critically revising the article: Tender, Kline. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Tender. Administrative/technical/material support: Tender. Study supervision: Tender.

Supplemental Information

If the inline PDF is not rendering correctly, you can download the PDF file here.

Article Information

INCLUDE WHEN CITING DOI: 10.3171/2016.12.FOCUS16470.

Correspondence Gabriel C. Tender, 2020 Gravier St., Ste. 744, New Orleans, LA 70112. email: gtende@lsuhsc.edu.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Images showing the first rib fluoroscopic projection and the corresponding mark on the skin.

  • View in gallery

    Photograph showing the skin incision centered on the first rib marking, between midline and the medial border of the scapula in a cadaver.

  • View in gallery

    Photograph showing cadaveric dissection exposing the first transverse process and rib. The exposure is maintained using self-retaining retractors.

  • View in gallery

    Fluoroscopic image of the cadaveric dissection illustrating the scapula retraction by the lateral, longer blade of the self-retaining retractor. This exposure allows for extensive dissection and resection of the first rib.

  • View in gallery

    Photograph of cadaveric dissection illustrating the exposure of the C-8 and T-1 spinal nerves and the lower trunk (LT) of the brachial plexus.

  • View in gallery

    Photograph showing cadaveric dissection before closure. The skin incision is only 6 cm long.

  • View in gallery

    A 3D CT reconstruction of the cadaveric specimen after dissection, illustrating the extent of the first rib resection.

  • View in gallery

    Case 1. Coronal (left) and axial (right) MRI studies of the brachial plexus prior to the modified posterior subscapular approach. The asterisk marks the first rib remnant.

References

  • 1

    Biggs MT: Posterior subscapular approach for specific brachial plexus lesions. J Clin Neurosci 8:3403422001

  • 2

    Clagett OT: Research and prosearch. J Thorac Cardiovasc Surg 44:1531661962

  • 3

    Dubuisson ASKline DGWeinshel SS: Posterior subscapular approach to the brachial plexus. Report of 102 patients. J Neurosurg 79:3193301993

  • 4

    Kline DGDonner TRHappel LSmith BRichter HP: Intraforaminal repair of plexus spinal nerves by a posterior approach: an experimental study. J Neurosurg 76:4594701992

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5

    Kline DGKott JBarnes GBryant L: Exploration of selected brachial plexus lesions by the posterior subscapular approach. J Neurosurg 49:8728801978

  • 6

    Tender GCKline DG: Posterior subscapular approach to the brachial plexus. Neurosurgery 57:4 Suppl3773812005

  • 7

    Tender GCThomas AJThomas NKline DG: Gilliatt-Sumner hand revisited: a 25-year experience. Neurosurgery 55:8838902004

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