Automated Volume Scanner System Ultrasonography for Evaluation of Varicose Veins of the Lower Extremities

Abstract

Objective:

To assess the utility of automated volume scanner system (AVSS) ultrasonography in the clinical evaluation of varicose veins of the leg.

Methods:

Varicose veins of the leg were evaluated using both handheld ultrasonography and AVSS. Morphological features (tortuosity, focal ectasia, thrombosis) and saphenous vein diameter were observed.

Results:

A total of 69 legs (43 patients) were examined. The overall quality of AVSS images was excellent in all cases. AVSS allowed visualization of the entire length of the great and small saphenous veins. Significantly more cases of tortuosity, focal ectasia and thrombosis were detected using AVSS than handheld ultra -sonography. The size and mean diameter of veins were consistent between the two methodologies.

Conclusions:

Coronal plane AVSS ultrasonography images were useful for the detection of tortuosity, focal ectasia and thrombosis. AVSS and handheld ultrasonography can be combined to provide both anatomical and functional information, facilitating the planning of surgical treatment of varicose veins.

Introduction

Varicose veins occur in the superficial veins of the legs, and are present in 10 – 40% of people aged between 30 and 70 years. ¹ The primary treatment is surgery, with preoperative evaluation essential to determine the cause and distribution of the varicose veins and identify any secondary reflux, allowing the development of an appropriate surgical plan. Inadequate preoperative evaluation is the main cause of recurrence. ² Various methods are used to evaluate varicose veins before surgery, including computed tomography (CT) venography and handheld ultrasonography, with the latter considered the gold standard noninvasive examination.^3,4 Ultra -sonography provides both anatomical and functional information, but is time consuming, dependent on experienced operators, and cannot reliably detect deep-seated varicose vein pathways and major perforators. ⁵ The automated breast volume scanner (ABVS) ultrasound system was developed for the imaging of radiographically dense breast tissue. ⁶ The aim of the current study was to evaluate the quality and utility of images obtained using an ABVS for the clinical evaluation of the superficial venous system in the legs of patients with varicose veins. The ABVS was renamed the automated volume scanner system (AVSS) for the purposes of this study.

Patients and methods

Study Population

Patients with primary, uncomplicated and previously untreated varicose veins attending the Department of Surgery, Huadong Hospital, Shanghai, China between June 2010 and July 2011, were recruited to the study. Patients with a history of lower-limb venous thrombosis were excluded.

The study was approved by the Ethics Committee of Fudan University affiliated Huadong Hospital, and all participants provided verbal consent prior to enrolment.

Assessment of Varicose Veins

A single investigator examined all patients using both handheld ultrasonography and the ACUSON S2000™ AVSS (Siemens Medical Solutions, Mountain View, CA, USA). Examinations were performed with the patient in a semi-supine position, with the upper body elevated at a 45° angle. The entire superficial venous network of the leg was examined, including the great saphenous vein (GSV) and small saphenous vein (SSV). Handheld ultrasonography was performed by an experienced vascular technologist using the ACUSON S2000,™ equipped with a 14L51 transducer (Siemens Medical Solutions). AVSS scanning was performed after handheld ultrasonography, with the entire length of the varicose veins scanned in order to generate a map of the venous anatomy. The ACUSON S2000™ was equipped with a large-format 50-mm linear array transducer (14L5BV; Siemens Medical Solutions) with a bandwidth of 5 – 14 MHz, that acquired a 15.4 × 16.8 × 6 cm (maximum display depth) image in a single sweep. Customized settings were used to optimize image depth, gain, frequency and view. The typical scanning time was 60 s and data were recorded at slice intervals of 0.5 mm. Data were reviewed in multiple orientations using an attached workstation with a multiplanar reconstruction display.

Images and characteristics of each patient's varicose veins were used to describe the superficial venous system, including: (i) varicose vein morphology; (ii) factors affecting visualization of varicose veins; (iii) presence of tortuosity, focal ectasia and thrombosis; (iv) diameter of GSV and SSV. Final assessment of images was performed by two radiologists, each with > 10 years' experience in general radiology (Y.C. and L.C.).

Statistical Analyses

Data were presented as mean ± SD and compared using the χ²-test. Statistical analyses were performed with SPSS^® software, version 11.5 (SPSS Inc., Chicago, IL, USA) for Windows^®. A P-value < 0.05 was considered statistically significant.

Results

The study included 43 patients with visible varicose veins (four women and 39 men; median age 53.5 years, age range 45.3 – 67.8 years). A total of 69 legs were assessed (26 patients with bilateral and 17 with unilateral varicose veins). Skin changes were present in 34 legs (31 legs with hyperpigmentation or lipodermatosclerosis and three legs with venous ulceration).

Abnormal skin thickening, subcutaneous oedema or thickening of the subcutaneous layer were present in 34 patients. AVSS imaging appeared unaffected by these factors and produced high-quality images of all varicose vein channels in each case. A typical varicose vain arrangement was seen in 29/69 legs, characterized by an effluent saphenous trunk with one or more varicose collaterals. Examples of varicose vein anatomy rendered by reconstruction of three orthogonal AVSS planes (transverse, sagittal and coronal) are shown in Fig. 1. Fig. 2 presents examples of reconstructed coronal AVSS images.

Figure 1:

Representative examples of automated volume scanner system ultrasonography images from two patients with varicose veins. (A) A 58-year-old man with a > 8-year history of varicose veins. (B) A 70-year-old man with a > 5-year history of varicose veins. In each case, views shown are coronal (left panel), transverse (upper right panel) and sagittal (lower right panel). Coronal images clearly show the dilated and elongated venous structures and the overall characteristics of the varicose veins (hypoechoic regions)

Figure 2:

Representative examples of automated volume scanner system ultrasonography images from two patients with varicose veins. (A) 55-year-old woman with > 6-year history of varicose veins. (B) 49-year-old man with > 3-year history of varicose veins. Views shown are: (A1, B1) coronal (left panel), transverse (upper right panel) and sagittal (lower right panel); (A2, B2) multislice coronal views. Coronal images clearly show the dilated and elongated venous structures and the overall characteristics of the varicose veins (hypoechoic regions)

Both methods identified the same number of varicose veins, but significantly more cases of tortuosity, focal ectasia and thrombosis were detected using AVSS compared with handheld ultrasonography (P < 0.05; Table 1). There was no significant difference in GSV or SSV diameter when measured using handheld ultrasonography or AVSS (Table 1). Fig. 3 provides representative coronal, sagittal and transverse AVSS images from three patients, indicating the utility of the coronal plane for the visualization of tortuosity, focal ectasia and thrombosis.

Figure 3:

Representative examples of automated volume scanner system ultrasonography images from three patients with varicose veins combined with tortuosity, focal ectasia or thrombosis. (A) Irregularly tortuous veins in the thigh of a 62-year-old man with a > 7-year history of varicose veins. (B) Focal ectasia (arrows) in a 57-year-old man with a > 3-year history of varicose veins. (C) Thrombosis (arrow) in a 73-year-old man with > 1 -month history of varicose veins. Views shown are coronal (left panel), transverse (upper right panel) and sagittal (lower right panel)

Table 1:

Comparison of the findings of automated volume scanner system (AVSS) and handheld ultrasonography examinations of the legs of patients with varicose veins (n = 69 legs from 43 patients)

Finding	AVSS	Handheld ultrasonography
Varicose veins	69 (100)	69 (100)
Tortuosity	54 (91.5)	29 (49.2)*
Focal ectasia	7 (11.9)	5 (8.5)*
Thrombosis	3 (5.1)	1 (1.7)*
GSV diameter, mm	7.2 ± 1.3	6.8 ± 1.7
SSV diameter, mm	5.6 ± 1.1	5.3 ± 1.3

Data presented as n (%) of legs or mean ± SD.

GSV, greater saphenous vein; SSV, small saphenous vein.

*

P < 0.05; χ²-test.

Discussion

Accurate preoperative evaluation of varicose veins is required in order to determine the best surgical strategy and improve the success rate following treatment. ⁷ Invasive and noninvasive methods are available for the examination of varicose veins. Invasive tests, such as ascending venography and CT venography, are accurate but may cause discomfort and complications.^1,8 Commonly used noninvasive tests include handheld ultrasonography, photo plethysmography and air plethysmography,^1,9,10 with ultrasonography considered the gold standard.^{11 – 13} Several types of venous ultrasonography are available, including compression ultrasound, duplex ultrasound and colour Doppler imaging.^14,15 Ultrasonographic examination of the entire affected area can be time consuming and requires experienced medical staff.^16,17 In addition, ultrasonography can only be used to evaluate a small area surrounding a suspected lesion. The present study therefore used AVSS to obtain detailed and comprehensive anatomical information.

The use of AVSS in the present study allowed clear visualization of dilated saphenous trunk segments and easily identified dilated and tortuous collaterals. AVSS displayed the coronal plane in slices, which was particularly useful for determining the shape of varicose veins. AVSS images provided an excellent overview of varicose vein anatomy, but lacked functional information on reflux or valvar insufficiency. Functional information may be derived from morphology, because focal ectasia, diffuse dilation and tortuosity are directly related to GSV/SSV varicosity. ⁵ AVSS produced high-resolution images that clearly showed the extent of superficial venous thrombosis, which is associated with deep venous thrombosis, pulmonary embolism and varicose vein recurrence. ¹⁸

The AVSS technique has several advantages over conventional handheld ultrasound. AVSS is operator independent and rapid to perform, providing high-resolution images after a few minutes of scanning. The high resolution allows the visualization of considerably smaller vessels than is possible with handheld ultrasonography. AVSS images of the anatomy were rendered via reconstruction of three orthogonal planes. AVSS clearly showed tortuosity and dilation, and visualized complex networks of varicosity, in particular the segmental organization of vascular tissue. Although handheld ultrasonography has good resolution and is useful for evaluating venous insufficiency, it is time consuming and it is difficult to show an overview of the clinical situation. AVSS was significantly better than handheld ultrasonography at detecting tortuosity, focal ectasia and thrombosis in the present study, largely due to the availability of a coronal view. The coronal plane provides physicians with a comprehensive view of the vasculature from the skin line to the muscle in a series of images.

In the present study, AVSS evaluation of the superficial venous system provided comprehensive anatomical information regarding varicose veins. There are several disadvantages of AVSS compared with conventional ultrasonography, however. Unlike Doppler ultrasonography, AVSS cannot provide information about the velocity or direction of flow. ⁶ In addition, high-frequency ultrasonography cannot penetrate deep tissue, ¹⁹ preventing the visualization of the deep venous system and perforators with AVSS. Finally, only compression ultrasonography allows the assessment of vein compressibility and echogenicity within the lumen, for the diagnosis of deep venous thrombosis.^20,21

In conclusion, AVSS and handheld ultrasonography are complementary diagnostic methodologies that can be combined to provide both anatomical and functional information, facilitating the planning of surgical treatment of varicose veins.