Clavicle-induced narrowing of the thoracic outlet during shoulder abduction as imaged by computed tomographic angiography and enhanced by three-dimensional reformation

Position- and posture-dependent vascular imaging-a scoping review

OBJECTIVES

Position- and posture-dependent deformation of the vascular system is a relatively unexplored field. The goal of this scoping review was to create an overview of existing vascular imaging modalities in different body positions and postures and address the subsequent changes in vascular anatomy.

METHODS

Scopus, Medline, and Cochrane were searched for literature published between January 1, 2000, and June 30, 2022, incorporating the following categories: image modality, anatomy, orientation, and outcomes.

RESULTS

Out of 2446 screened articles, we included 108. The majority of papers used ultrasound (US, n = 74) in different body positions and postures with diameter and cross-sectional area (CSA) as outcome measures. Magnetic resonance imaging (n = 22) and computed tomography (n = 8) were less frequently used but allowed for investigation of other geometrical measures such as vessel curvature and length. The venous system proved more sensitive to postural changes than the arterial system, which was seen as increasing diameters of veins below the level of the heart when going from supine to prone to standing positions, and vice versa.

CONCLUSIONS

The influence of body positions and postures on vasculature was predominantly explored with US for vessel diameter and CSA. Posture-induced deformation and additional geometrical features that may be of interest for the (endovascular) treatment of vascular pathologies have been limitedly reported, such as length and curvature of an atherosclerotic popliteal artery during bending of the knee after stent placement. The most important clinical implications of positional changes are found in diagnosis, surgical planning, and follow-up after stent placement.

CLINICAL RELEVANCE STATEMENT

This scoping review presents the current state and opportunities of position- and posture-dependent imaging of vascular structures using various imaging modalities that are relevant in the fields of clinical diagnosis, surgical planning, and follow-up after stent placement.

KEY POINTS

• The influence of body positions and postures on the vasculature was predominantly investigated with US for vessel diameter and cross-sectional area. • Research into geometrical deformation, such as vessel length and curvature adaptation, that may be of interest for the (endovascular) treatment of vascular pathologies is limited in different positions and postures. • The most important clinical implications of postural changes are found in diagnosis, surgical planning, and follow-up after stent placement.

Combined nerve and vascular ultrasound in thoracic outlet syndrome: A sensitive method in identifying the site of neurovascular compression

We investigated the diagnostic utility of combined nerve and vascular ultrasound in thoracic outlet syndrome (TOS) in a retrospective cohort study on two sites, involving 167 consecutive patients with the clinical symptoms suggestive of neurogenic and/or vascular TOS, and an age- and sex-matched control group. All patients and control subjects underwent nerve ultrasound of the supraclavicular brachial plexus to look for fibromuscular anomalies / compression of the brachial plexus in the scalenic region, and vascular ultrasound of the infraclavicular subclavian artery with the arm in neutral and abducted position, serving as an indicator for costoclavicular compression of the neurovascular bundle. Based on clinical symptoms, neurogenic TOS (81%) was the most frequent type of TOS, followed by combined neurogenic and arterial TOS (8%). The frequency of abnormal nerve and/or vascular ultrasound findings differed significantly from the control group (P<0.00001). The pooled sensitivity was 48% for nerve ultrasound, 85% for vascular ultrasound, and 94% when combined. Among the findings, the fibromuscular ‘wedge-sickle sign’, indicating compression of the lower trunk in the scalenic region by a congenital fibromuscular anomaly (e.g. Roos ligaments), showed the highest specificity (100%). A bony ‘wedge-sickle sign’ was also delineated, where lower trunk compression is caused by the neck of the 1^st rib. As implied by the higher sensitivity of vascular ultrasound, the most common site of compression was the costoclavicular space, but multilevel compression was also frequently observed. In summary, combined nerve and vascular ultrasound is a sensitive and reliable method to support the diagnosis of TOS. It can also identify the site(s) of compression, with obvious therapeutic consequences.

Measurement of Outlet Pressures Favors Rib Resection for Decompression of Thoracic Outlet Syndrome

BACKGROUND

When conservative therapy for thoracic outlet syndrome fails, scalenectomy with or without first-rib resection (FRR) is the treatment of choice. We measured pressure in the costoclavicular space before and after FRR at time of neurogenic thoracic outlet syndrome release to evaluate whether FRR is required to completely decompress the costoclavicular space.

METHODS

Using a supraclavicular exposure for anterior-middle scalenectomy with FRR, costoclavicular space pressures were measured using a balloon catheter with the patient's arm in neutral anatomic position, secondarily, the arm abducted and externally rotated. Pressures were recorded in both arm positions before scalenectomy, after scalenectomy, and after FRR. Paired Student's t test was used to compare differences in group means for paired samples. Patient-reported outcomes were reported using the Derkash classification and quick disabilities of the arm, shoulder, and hand (qDASH) questionnaire.

RESULTS

Fifteen patients (16 cases) surgically treated for neurogenic thoracic outlet syndrome were included in this retrospective study. There was no significant difference in pressure change between arm positions before scalenectomy (161.56 ± 71.65 mm Hg difference) or after scalenectomy (148.5 ± 80.24 mm Hg difference). There was a significant difference in pressure change between post-scalenectomy and post-FRR arm positions; mean pressure change between arm positions after FRR was 50.56 ± 40.28 mm Hg. Mean postoperative qDASH score was 20 ± 23.2. All patients reported improvement in symptoms and functional status.

CONCLUSIONS

Supraclavicular first rib resection for management of neurogenic thoracic outlet syndrome can be safely performed with favorable outcomes. The pressure increase in the costoclavicular space caused by arm abduction and external rotation was significantly reduced only after FRR, raising concerns about potential incomplete costoclavicular space decompression with scalenectomy alone for neurogenic thoracic outlet syndrome management.

Evaluation of a Novel Bony Landmark-Based Method for Teaching Percutaneous Insertion of Subclavian Venous Catheters in Pediatric Patients

BACKGROUND

Surgical trainees performing subclavian vein (SCV) cannulation often incorrectly perceive needle trajectory and anatomical relations. As surface landmark-based methods derived from adult surgical practice may be less effective in younger patients, we developed and evaluated a novel bony landmark-based method for teaching SCV cannulation for central venous access device (CVAD) placement in children.

METHODS

Over 2 sequential 3-year periods, pediatric surgical trainees were taught infraclavicular SCV cannulation via surface- and bony-landmark approaches, respectively. We prospectively recorded patient, surgeon and operative details on all Hickman line and port-a-cath insertions placed by trainees as the first surgeon via percutaneous infraclavicular SCV puncture and compared procedural outcomes and complications across both periods.

RESULTS

Of 271 cases included in the study, trainees performed 52 (50.5%) and 92 (54.8%) procedures in the first and second periods, respectively. Patients in both periods did not differ by gender, disease, CVAD device, or prior CVAD, chemotherapy or infection status. In the second (bony landmark) period, although patients were younger (6.0 vs. 8.7 years, P = 0.003) mean procedural duration was shorter (42.5 vs. 58.3 min, P < 0.001). Also, cannulation attempts and complication rates did not differ significantly between study periods (P = 0.257 and 1.0, respectively).

CONCLUSIONS

With the bony landmark approach, trainees could perform the procedures faster despite operating on younger patients, without impacting complication rates and cannulation attempts. Bony landmarks may better approximate SCV position across a range of ages, thus improving the consistency of SCV cannulation in CVAD placements in children.

Effect of Arm Positioning on Entrapment of Infraclavicular Nerve Block Catheter

Continuous brachial plexus nerve block catheters are commonly inserted for postoperative analgesia after upper extremity surgery. Modifications of the insertion technique have been described to improve the safety of placing an infraclavicular brachial plexus catheter. Rarely, these catheters may become damaged or entrapped, complicating their removal. We describe a case of infraclavicular brachial plexus catheter entrapment related to differences in arm positioning during catheter placement and removal. Written authorization to obtain, use, and disclose information and images was obtained from the patient.

Case report: Thoracic outlet syndrome in an elite archer in full-draw position

BACKGROUND

One possible pathomechanism of thoracic outlet syndrome (TOS) is shoulder abduction and extension inducing backward motion of the clavicle which causes compression on the brachial plexus. This position occurs during the full-draw stage of archery, by drawing and holding the bowstring.

CASE DESCRIPTION

A 28-year-old elite archer presented with a feeling of weakness and dull shoulder pain, and experienced decreased grip power and hypoesthesia in the ulnar nerve dermatome in the full-draw position. On CT angiography, the cross-sectional area of the subclavian artery in the costoclavicular space decreased to 40% compared with that of the subclavian artery in a noncompressed state. This patient had first rib resection through the supraclavicular approach with a clavicle osteotomy. At 3.5 years postoperatively, the patient maintained his job as a professional coach and did not have any specific complaints when teaching and demonstrating archery skills.

LITERATURE REVIEW

A literature review revealed numerous causes of TOS, ranging from congenital abnormalities to repetitive postures related to sports activities. The abduction and external rotation (ABER) position (shoulder at 90° abduction and external rotation) has been suggested for detecting TOS and is a documented cause of compression of the brachial plexus and subclavian vessels. We present the case of an archer with TOS association with repeated use of the ABER position.

PURPOSE AND CLINICAL RELEVANCE

TOS should be suspected when athletes repeatedly use shoulder extension and abduction for their sports if other pathologic conditions can be ruled out.