PART II – Imaging
In general, ultrasound (US) is the first-line imaging modality for peripheral aneurysm assessment. It is readily available, applicable on-site, inexpensive, patient friendly and enables non-invasive measurement of vessel diameters and detection of intravascular thrombus. Currently there is no standardized vascular US protocol available for imaging the PCHA. Such a protocol would enable worldwide uniform assessment of PCHA pathology. Moreover, given the complex local anatomy, including the frequently nearby originating and closely resembling deep brachial artery (DBA), evidence based recommendations and instructions for imaging would enable targeted PCHA identification and assessment.
Chapter 6 – SPI-US protocol
In chapter 6, we present a 4-step standardized vascular US protocol for assessing the proximal PCHA: the Shoulder PCHA pathology and digital Ischemia – UltraSound (SPI-US) protocol. International standardization of PCHA imaging will help in accurate identification and assessment.
Related article: van de Pol D, Maas M, Terpstra A, Pannekoek-Hekman M, Kuijer PPFM, Planken RN. B-mode ultrasound assessment of the Posterior Circumflex Humeral Artery – the SPI-US protocol: a technical procedure in 4 steps Journal of Ultrasound in Medicine. 2016 May;35(5):1015-20. – link
Chapter 7 – Inter-rater reliability of the SPI-US protocol
The next step in the development of the SPI-US protocol was to assess its measurement properties. In chapter 7, the inter-rater reliability of the SPI-US protocol for diameter assessment of the PCHA and DBA was assessed. Two vascular technologists independently determined diameters of the PCHA and DBA in 32 healthy volunteers using the SPI-US protocol. The results showed that the SPI-US protocol is accurate and precise for diameter assessment of the PCHA (ICC=0.70; 95%CI 0.50-0.83) and DBA (ICC=0.60; 95%CI 0.30-0.80), with sonographer-independent PCHA diameter measurements. Moreover, with a calculated Minimal Detectable Change (MDC) of 0.90 mm, the SPI-US seemed clinically valid for aneurysm detection when performed by experienced vascular technologists. International dissemination of this protocol might make it possible to identify PCHA injury, both in an on-site screening setting, and in a clinical setting.
Related article: van de Pol D, Alaeikhanehshir S, Kuijer PPFM, Terpstra A, Pannekoek-Hekman M, Planken RN, Maas M. Reproducibility of the SPI-US protocol for ultrasound diameter measurements of the Posterior Circumflex Humeral Artery and Deep Brachial Artery: an inter-rater reliability study. European Radiology. 2016 Aug;26(8):2455-61. – link
Chapter 8 – Aneurysm prevalence and vessel characteristics of the PCHA and DBA
The objectives of chapter 8 were twofold. The first objective was to determine the prevalence of PCHA aneurysms in the dominant shoulder in elite volleyball players. The second objective was to describe PCHA and DBA anatomy, branching pattern, course and diameters. The SPI-US protocol was used to assess the PCHA and DBA in the dominant shoulder in 280 elite indoor and beach volleyball players, 245 men and 35 women. The PCHA was identified in 100% of the cases. Aneurysms were detected in the proximal PCHA in 4.6% (13/280) of elite volleyball players and associated with a specific branching type, namely a PCHA that originates directly from the axillary artery. The PCHA originated from the axillary artery (AA) in 81% of cases (228/280), and showed a curved course dorsally towards the humeral head in 93% of these cases (211/228), with a mean diameter of 3.8 mm (95%CI 3.7-3.9) in men, and 3.5 mm (95%CI 3.3-3.7) in women. The DBA was identified in 93% of cases (260/280), all without aneurysms. The DBA originated from the AA in 73% of cases (190/260), and showed a straight course parallel to the AA in 93% of these cases (177/190), with a mean diameter of 2.3 mm (95%CI 2.2-2.3) in men, and 2.0 mm (95%CI 1.9-2.2) in women. The described vessel characteristics and diameters provide clear guidance to identify and assess the PCHA and DBA using US. The high prevalence of detected PCHA aneurysms among elite volleyball players demands an active policy on prevention and periodic surveillance.
Related article: van de Pol D, Maas M, Terpstra A, Pannekoek-Hekman M, Alaeikhanehshir S, Kuijer PPFM, Planken RN. Ultrasound assessment of the Posterior Circumflex Humeral Artery in elite volleyball players: aneurysm prevalence, anatomy, branching pattern and vessel characteristics. European Radiology. 2017 Mar;27(3):889-898. – link