NEUROSURGICAL FOCUS Neurosurg Focus 42 (3):E7, 2017

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

Clifford L. Crutcher II, MD, David G. Kline, MD, and Gabriel C. Tender, MD

Department of Neurosurgery, Louisiana State University, New Orleans, Louisiana

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 sub- scapular approach, using a small, self-retaining retractor and only a partial trapezius and rhomboid minor muscle dissec- tion. This approach is likely to result in decreased postoperative morbidity and a shorter hospital stay. https://thejns.org/doi/abs/10.3171/2016.12.FOCUS16470 KEY WORDS brachial plexus; posterior subscapular approach; thoracic outlet syndrome

he posterior subscapular approach to the brachial centered on the first rib skin marking (Fig. 2). The trape- plexus is safe and effective.6 Its indications in- zius muscle layers are divided parallel to the orientation of clude: thoracic outlet syndrome (TOS) and recur- the muscle fibers. The rhomboid minor muscle is divided Trent TOS,7 brachial plexus tumors involving the proximal similarly in the depth, and the T-1 costotransverse joint roots, postirradiation brachial plexopathy, and proximal is encountered. This is confirmed by palpation as well as brachial plexus palsy.3 The posterior approach is espe- fluoroscopy. (At this level, only the rhomboid minor needs cially helpful for brachial plexus access in patients with to be dissected. The rhomboid major and the levator scap- previous irradiation to the neck or anterior chest wall, ulae are caudal and cranial to this exposure, respectively, previous anterior neck surgery, or morbid obesity.3 The and therefore are not affected.) At this time, self-retaining advantages of this approach include ease of exposure, ex- retractors (Trimline; Medtronic) are positioned to main- 4 posure of the intraforaminal portion of spinal nerves, and tain the exposure, with a shorter blade toward the midline protection of important vasculature. The major drawback and possibly a longer blade laterally, over the first rib and of the posterior approach is the morbidity associated with 3 under the scapula (Fig. 3). The lateral blade can also be extensive muscle dissection. We describe a modified, less rested against the soft tissues, if extensive lateral exposure invasive posterior subscapular approach to the lower bra- is not necessary. chial plexus. The T-1 transverse process is removed with a high- speed drill or Leksell rongeur, thus exposing the head of Operative Technique the first rib. An elongated C-7 transverse process can be The patient is placed prone, with adequate padding for removed in a similar fashion, if necessary. The soft tissues all pressure points. The operative side is slightly elevated, are then carefully detached from the first rib with a perios- with additional padding underneath the clavicle to abduct teal elevator (Fig. 4), and the rib is removed in a piecemeal the shoulder. The arms are padded and tucked to the side. fashion, starting medially with the rib head. The lateral Fluoroscopic guidance is used mark the projection of the extent of the resection of the first rib depends on the un- posterior aspect of the first rib on the skin (Fig. 1). A 6-cm derlying pathology, but the resection can be extended all skin incision is made approximately halfway between the the way to the anterior aspect of the first rib. This allows spinous processes and the medial border of the scapula, for exposure of the C-8 and T-1 spinal nerves, as well as

ABBREVIATIONS TOS = thoracic outlet syndrome. SUBMITTED November 1, 2016. ACCEPTED December 5, 2016. INCLUDE WHEN CITING DOI: 10.3171/2016.12.FOCUS16470.

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FIG. 1. Images showing the first rib fluoroscopic projection and the cor- responding mark on the skin. 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 FIG. 3. Photograph showing cadaveric dissection exposing the first level of interest. The wound is closed in anatomical lay- transverse process and rib. The exposure is maintained using self- ers. The muscles typically revert to their original position retaining retractors. without a need for reapproximation (Fig. 6). noted progressively increasing pain over the past year ra- Cadaveric Study diating from the neck and trapezius muscle down the arm and into the last 3 digits. Her arm visual analog scale score We performed this approach on 3 cadavers with no was 10/10 and her Oswestry Disability Index was 74. On associated pathological entities or gross anatomical ab- physical examination, she had mild right abductor digiti normalities. The dissection and first rib removal were minimi and abductor pollicis brevis weakness (MRC 4/5). extended as far anterior as technically feasible. The C-8 and T-1 spinal nerves, as well as the lower trunk, were Imaging Studies exposed without difficulty. Preoperative and postoperative Imaging studies revealed a remnant of the first rib and CT scans were obtained to determine the extent of the first rib head (Fig. 8). An electromyogram and a nerve conduc- rib resection (Fig. 7). tion study confirmed chronic denervation of the T-1 more than the C-8 dermatomes. After a discussion of risks, ben- 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 trans- axillary first rib resection 1 year prior to presentation. The patient reported no improvement after this operation and

FIG. 4. Fluoroscopic image of the cadaveric dissection illustrating the FIG. 2. Photograph showing the skin incision centered on the first rib scapula retraction by the lateral, longer blade of the self-retaining retrac- marking, between midline and the medial border of the scapula in a tor. This exposure allows for extensive dissection and resection of the cadaver. first rib.

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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. efits, alternatives, and expectations, the patient elected to sion was well healed and there was no associated muscle undergo a modified, less invasive posterior subscapular atrophy or winged scapula. The patient reported subjective approach for surgical removal of the first rib remnant and improvement in hand strength, although by the time of ex- exploration of the C-8 and T-1 spinal nerves (Video 1). amination there was still a persistent slight weakness in VIDEO 1. The modified, less invasive posterior subscapular the same muscles. 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. Discussion Preparations were made to be able to convert to a classic The posterior subscapular approach has proven to be subscapular approach if necessary. safe and effective. The original version of this approach was used for patients with tuberculosis pulmonary lesions, 2 Operation and Postoperative Course as described by Clagett. The surgical technique was par- tially modified and adapted to access the lower brachial The operating time was 120 minutes and the estimated blood loss was less than 50 ml. There were no compli- cations. The patient tolerated the procedure well and was discharged the following morning. At the 3-month follow- up visit, her visual analog scale score for arm pain was 4/10 and the Oswestry Disability Index was 22. The inci-

FIG. 6. Photograph showing cadaveric dissection before closure. The FIG. 7. A 3D CT reconstruction of the cadaveric specimen after dissec- skin incision is only 6 cm long. tion, illustrating the extent of the first rib resection.

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lower proximal plexus. However, larger tumors, espe- cially 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 re- quire more than the first rib removed. Conclusions The modified, less invasive posterior subscapular ap- proach is technically simple and appears to be associated FIG. 8. Case 1. Coronal (left) and axial (right) MRI studies of the bra- with less morbidity than the traditional approach. Poten- chial plexus prior to the modified posterior subscapular approach. The tial advantages include reduced blood loss, less postoper- asterisk marks the first rib remnant. ative pain, decreased length of stay, and faster return to function. Surgical indications are similar to the traditional posterior subscapular approach. However, due to the de- plexus lesions, and a first case series was published in creased morbidity, the modified, less invasive approach 5 1978 by Kline et al. The posterior subscapular approach may become a surgical option of choice in patients with offered the advantage, among others, of exposing the fo- lower brachial plexus pathology. raminal 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 References be accessed using this surgical technique.3 Complications 1. Biggs MT: Posterior subscapular approach for specific bra- in this series included winged scapula, cervical spine in- chial plexus lesions. J Clin Neurosci 8:340–342, 2001 2. Clagett OT: Research and prosearch. J Thorac Cardiovasc stability when more than 2 facets were removed, pleural Surg 44:153–166, 1962 tears, pneumo- or hemothorax, phrenic nerve injury palsy, 3. Dubuisson AS, Kline DG, Weinshel SS: Posterior subscapu- or new or further damage to the brachial plexus. Accord- lar approach to the brachial plexus. Report of 102 patients. J ing to the senior author (D.G.K.), the average estimated Neurosurg 79:319–330, 1993 blood loss was between 600 and 750 ml, and the average 4. Kline DG, Donner TR, Happel L, Smith B, Richter HP: length of hospitalization was 5–6 days (longer in patients Intraforaminal repair of plexus spinal nerves by a posterior with severe trauma or large tumors). The skin incision, approach: an experimental study. J Neurosurg 76:459–470, extending roughly from just below the tip of the scapula 1992 5. Kline DG, Kott J, Barnes G, Bryant L: Exploration of se- to the cranial-most aspect of the trapezius muscle in the lected brachial plexus lesions by the posterior subscapular paraspinal region, was between 30 and 40 cm in length. approach. J Neurosurg 49:872–880, 1978 The posterior subscapular approach offers excellent 6. Tender GC, Kline DG: Posterior subscapular approach to the exposure of the proximal brachial plexus (particularly brachial plexus. Neurosurgery 57 (4 Suppl):377–381, 2005 the lower elements), as well as lesions extending into the 7. Tender GC, Thomas AJ, Thomas N, Kline DG: Gilliatt- chest.1 However, it is usually considered a second (or third) Sumner hand revisited: a 25-year experience. Neurosurgery operative choice, due to the morbidity associated with the 55:883–890, 2004 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 Disclosures retraction of scapula. The authors report no conflict of interest concerning the materi- The modified, less invasive approach takes advantage als or methods used in this study or the findings specified in this of the availability of a strong yet relatively small self-re- paper. taining retractor, such as Trimline or analogs. These re- tractors are typically very familiar to surgeons from their Author Contributions use in the anterior cervical approaches. After exposure of Conception and design: Tender, Kline. Acquisition of data: Ten- the first transverse process, the self-retaining retractor can der, Crutcher. Analysis and interpretation of data: Tender, Kline. be used to push the scapula laterally with sufficient force Drafting the article: Tender, Crutcher. Critically revising the arti- cle: Tender, Kline. Reviewed submitted version of manuscript: all to allow for exposure of the first rib (and second or third authors. Approved the final version of the manuscript on behalf rib, if necessary). Moreover, using a longer blade laterally, of all authors: Tender. Administrative/technical/material support: the first rib curvature can be followed all the way to its Tender. Study supervision: Tender. turn, thus providing safety for rib isolation and resection. In muscular patients, in whom scapular retraction may be Supplemental Information difficult, the ipsilateral arm can be placed on a padded Videos Mayo stand, similar to the traditional technique. Video 1. https://vimeo.com/198341360. Given the limited muscle dissection and easy closure, the morbidity of the posterior subscapular approach seems Correspondence to be decreased. Therefore, this approach may become a Gabriel C. Tender, 2020 Gravier St., Ste. 744, New Orleans, LA first option in patients with TOS or tumors involving the 70112. email: [email protected].

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