|Year : 2016 | Volume
| Issue : 2 | Page : 79-83
Colour doppler application in vascular diseases as seen in Benin City, Nigeria
Stanley Ukadike Okugbo1, Adenike Olayemi Akhigbe2
1 Department of Surgery, Division of Cardiothoracic, University of Benin Teaching Hospital, Benin City, Nigeria
2 Department of Radiology, University of Benin Teaching Hospital, Benin City, Nigeria
|Date of Submission||22-Apr-2015|
|Date of Acceptance||18-Apr-2016|
|Date of Web Publication||21-Jun-2016|
Dr. Stanley Ukadike Okugbo
Department of Surgery, University of Benin Teaching Hospital, PMB 1111, Benin City
Background: Doppler ultrasound scan (DUS) is not a new investigative tool but has however been relatively absent in our resource-poor setting. In its deployment, it requires both expensive equipment and trained personnel; both of which are somewhat lacking in our resource-poor setting. Aims: This is a retrospective study undertaken to audit the first set of patients who had DUS at a private facility in Benin City. A retrospective review of indications versus eventual diagnosis in 173 patients was seen from April 2009 to August 2013. Materials and Methods: This is a retrospective study from April 2009 to August 2013 undertaken to audit the first set of patients who had DUS at a private institution in Benin City. The medical notes and referral forms clinic data of patients seen from April 2009 to August 2013 were collated. Results: In the period under review, 173 patients were scanned. The mean age of the patients was 51.2 ± 20 years (range of 2 months to 94 years). The main indications were deep venous thrombosis (DVT) in 60 (35.5%) patients and peripheral arterial disease in 55 (31.8%). There was a bimodal age distribution at 20-30 and 55-70 years, and the younger age group had a preponderance of trauma with DVT and aneurysms while the older had arteriosclerosis and DVT. The lower limb was the part of the body scanned most frequently scanned (79.4%). Conclusion: DUS is a useful tool for timely evaluation of vascular lesions. Despite the siting of sonographic equipment outside a hospital setting, patients are able to access it to provide useful addition to their management.
Keywords: Deep venous thrombosis, peripheral arterial disease, ultrasound scan, vascular Doppler
|How to cite this article:|
Okugbo SU, Akhigbe AO. Colour doppler application in vascular diseases as seen in Benin City, Nigeria. Sub-Saharan Afr J Med 2016;3:79-83
|How to cite this URL:|
Okugbo SU, Akhigbe AO. Colour doppler application in vascular diseases as seen in Benin City, Nigeria. Sub-Saharan Afr J Med [serial online] 2016 [cited 2020 Apr 1];3:79-83. Available from: http://www.ssajm.org/text.asp?2016/3/2/79/184354
| Introduction|| |
Doppler ultrasound scan (DUS) is not a new investigative tool;  however, it has been relatively absent in our resource-poor setting. It is a very important tool for investigating diseases affecting both arteries and veins. , In its deployment, it requires both expensive machinery and trained personnel; , both of which are lacking in our resource-poor settings. ,
Indications for DUS range from arterial obstructive lesions such as atherosclerosis,  trauma,  and embolism to venous lesions such as deep venous thrombosis (DVT), ,,, superficial venous thrombosis, varicose veins, arteriovenous (AV) fistulas, and malformations. For DVT, if forms the mainstay of investigation and affords both quick analysis of the extent and monitoring of the treatment. ,, It can be repeated as needed since it does not use ionizing radiation. ,,, For peripheral arterial obstruction and carotid plaques, it is the investigation of choice allowing for quick assessment,  providing a good measure of the function of the arteries with the measurement of the blood pressures, flow velocity, size of the vessels, and adequate assessment of the plaques. 
The main drawback is that it is observer dependent though training and acquiring of the required skill are quickly achieved. 
This study was undertaken to audit the Doppler studies done at a private institution in Benin City.
| Materials and Methods|| |
A retrospective review was carried out to audit the first set of patients who had DUS at a private facility in Benin City. It involved all patients who presented for vascular Doppler studies from April 2009 to August 2013. Their clinical data and biodata were collated and the result of the DUS collated.
The studies were conducted using two ultrasound machines with color Doppler facilities. (1) Philips Medical System HDI 5000, ATL Ultrasound, USA 2000, with multi-frequency linear and convex probes. The linear probe has a frequency range of 4-7 MHz while the convex probe is 2-4 MHz. (2) Siemens G 60 Sonoline system, Germany 2004, with multi-frequency linear and convex probes. The linear probe has a frequency range of 5-10 MHz and the convex probe has frequency of 2-5 MHz.
The imaging protocols chosen were determined by the indication for and site to be studied.
Venous Studies of the Lower or Upper Limbs
Grayscale scan of the major veins was performed to assess for presence of thrombus within the lumen, and with application of color flow Doppler, residual blood flow in such vessels was assessed. Compressibility of the vessels was also assessed as presence of thrombus in chronic DVT causes noncompressibility. Duplex Doppler examination of the major veins was done to assess for spontaneity of flow, phasic flow, augmentation and effect of Valsalva maneuver. These changing Doppler signals are indicative of obstruction or extrinsic compression. 
Arterial Studies of the Lower and Upper Limbs
This was done using grayscale, color flow, and duplex Doppler examination. The vessels were sampled using 60° angle of insonation for Doppler tracings and peak systolic velocity (PSV) measurements. Peripheral arterial disease (PAD) was assessed using Doppler spectral analysis where normal waveform is triphasic with clear spectral window and abnormal waveforms range from mild disease with triphasic waveform plus minimal spectral broadening to moderate disease with biphasic waveform plus spectral broadening and severe disease with monophasic waveform plus severe spectral broadening and arterial occlusion with absence of spectral information.  Using grayscale images, arteries were assessed for presence of plaques and characteristics of the plaques. Arterial occlusions, AV fistulas, and aneurysms were assessed with color flow images.
Carotid Artery Studies
These were done using grayscale, color flow, and duplex Doppler methods. The carotid intima-media thickness was measured, and the presence of plaques as well as types of plaques was assessed on the grayscale image. Stenotic effect of plaques was assessed using color flow and duplex Doppler examinations, and the vessels were sampled using 60° angle of insonation for PSV measurements. The Doppler criteria for stenosis were applied. 
Abdominal Vascular Studies
For renal vascular studies, the renal vessels were assessed using color flow for flow abnormalities such as aliasing in renal artery stenosis and other abnormalities such as renal artery aneurysm, AV malformation, and fistula as well as renal artery occlusion and infarction. Using duplex Doppler assessment with 60° angle of insonation, PSV and end diastolic velocity were measured. From these measurements, resistive index (RI), pulsatility index, and renal-to-aortic ratio (RAR) were derived to assess for flow abnormalities in patients with suspected renovascular hypertension.
Other Intra-abdominal Vascular Studies Included
- Assessment of the abdominal aorta for aneurysm or coarctation in patients presenting with pulsatile abdominal mass
- Assessment of the inferior vena cava for dilatation, thrombus, and other abnormalities
- Assessment of the hepatic vessels and portal veins
- Assessment of the celiac and superior mesenteric arteries.
| Results|| |
There were 173 patients in all with a male: female ratio of 3:2.
The mean of age of the patients was 51.2 ± 20 years with a range of 2 months to 94 years.
The mean age of males was 52 years (standard deviation [SD] 20 years) which was higher than the mean age of females of 49 years (SD 21 years).
The patients in the study showed a bimodal age distribution at 20-30 and 55-70 years [Figure 1].
The main indication was DVT in 60 (35.5%) patients and PAD 52 (30.8%). Carotid artery assessment in stroke patients accounted for 19 (11.2%); aneurysms was the indication in 15 (8.9%) patients while trauma and varicose veins were 9 (5.3%) each [Table 1].
Of the patients with initial clinical assessment of DVT, 36 (60%) patients were confirmed by DUS while 13 (21.7%) turned out to be normal and 5 (8.3%) were found to be PAD. However, 44 (80.0%) patients with initial clinical assessment of PAD were confirmed by DUS and 9 (16.4%) turned out be normal scans [Table 2].
|Table 2: The cross tabulation of the clinical versus the Doppler ultrasound scan diagnosis |
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Analysis of the pathologies confirmed with DUS scan showed that 87.8% (36) of patients had clinical suspicion of DVT as the indication for the referral.
PAD was the indication in 84% (42) and DVT was the indication in 10% (5) of the 50 patients while DUS confirmed PAD in them.
DUS turned out to be normal in 31 patients. Of these, the indication for DUS was DVT in 41.9% (13), PAD in 29% (9), and trauma in16.1% (5) [Table 3].
|Table 3: The distribution of initial clinical impression for the confirmed deep venous thrombosis, peripheral arterial disease, and normal cases |
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The bimodal age distribution further analyzed showed that the younger age group had a preponderance of trauma with associated aneurysms, lacerations, wounds, and DVT while in the older age group, the most frequent indications were mainly arteriosclerosis and DVT. This was statistically significant with ANOVA F of 10.673 and P < 0.0001 [Table 4].
|Table 4: The mean age according to the final Doppler ultrasound scan diagnosis |
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The most frequently scanned part of the body was the lower limb (79.4%), followed by the neck in 12.4% [Figure 2].
| Discussion|| |
Suspected cases of DVT and limb ischemia made up over 66% of referrals for DUS in this study. Invariably, they form the majority of cases of vascular lesions seen in this part of the world. ,,,, It is imperative in these patients who prompt confirmation of diagnosis is made in view of the feared complications of loss of limb and/or life without prompt treatment. Empirical treatment is rife and fraught with multiple morbidities, ,, whereas monitoring of treatment and subsequent assessment is near impossible without adequate and timely DUS. ,,,
Of the sixty patients with clinical diagnosis of DVT, 60% were confirmed by DUS which showed good clinical judgment of the clinicians. For 40% of the patients whose clinical diagnosis did not correlate with DUS finding, they benefited from the DUS as it allowed proper diagnosis and management of their diseases which may have been fraught with morbidities if empirical treatment was carried out without DUS. Even in the confirmed cases of DVT, DUS allowed proper objective assessment of the DVT, its extent, complexity, and monitoring of adequacy of treatment. , Analysis of the patients with DUS confirmed DVT showed that in 87.8% of the patients, the clinical indication for DUS request was DVT showing that the clinical assessment by the clinicians was again quite accurate. The justification for DUS in suspected cases of DVT is that apart from confirmation of DVT, it is also imperative to have proper assessment of the extent of the thrombus, including the site, state, and in monitoring treatment. 
Of the patients with initial clinical diagnosis of PAD, 80.8% of them were confirmed by DUS. Several of these patients required proper DUS assessment of the extent of arterial involvement as well as collateral flow which helps to direct treatment and assess the options available for each individual patients. 
Of the 31 patients whose DUS assessment were reported to be "essentially normal," 41.9% had initial clinical assessment of DVT and 29% had initial clinical diagnosis of PAD. For these subsets of patients whose symptoms could be attributable to other causes, DUS provided a quick evaluation allowing the clinicians to focus and investigate them further to assess their clinical needs. ,,,
Only seven patients had multiple repeat scan as part of continuing assessment. This number is small considering the number of patients who required multiple scans to assess and monitor their treatment. This low number may have been due to either the logistics of movement to the center for the scan or compounding issues of cost.
Evidently, DUS should be available within the clinical setting in other to prevent further morbidities from movement of patients to a place outside their clinical setting. Mobile units are the norm where possible to minimize movements of patients who may be very ill. ,
The age distribution in our study showed two peaks, at 25 and 65 years. The younger age had a preponderance of trauma with aneurysms, lacerations, wounds, and DVT. The later age group had a preponderance of CVA, diabetic foot, and atherosclerosis. This is in keeping with the known distribution of these diseases. ,
There was a preponderance of males in this study that this may be attributed to the increase incidence of vascular lesions such as PAD in the males as reported by various studies. ,,, The age range also correlates well with previous reports and the known epidemiology of PAD. Generally, males are involved in many high-risk activities including violence, road traffic accidents, thus more susceptible to trauma.
There were a relatively small number of patients with aneurysms and AV fistulas in this study when juxtaposed with other indications. This correlates well with numbers seen in studies in Liberia and elsewhere in Sub-Saharan Africa. ,, This may be due to the clinicians being more confident of their clinical assessment and unwilling to further expend money to confirm the diagnosis. It may also be due to concerns about the usefulness of DUS in the further management of those patients or an over dependence on arteriography in such patients.  However, it is pertinent to note that DUS deplored in the emergency room would help the clinician accurately locate and identify bleeding points in concealed hemorrhage and aid immediate planning and treatment. ,, Even now, contrast-enhanced DUS is available (though not universally and with added cost), enabling better localization. ,
The predominant limb involved was the left lower limb followed closely by the right lower limb. This limb had both higher incidence of DVT and PAD. This may require further study to ascertain the reason for higher incidence of vascular lesions.
This study has highlighted the prevalence of arteriosclerosis in our patient population. There was a significant number of patients with strokes who had PAD. Thus, initial evaluation and treatment for PAD may help early identification of these patients and may lead to prevention of the cerebrovascular accidents that they present with. , Indeed, WHO has highlighted that screening for PAD may help identify such patients including those at risks for myocardial infarction. Routine screening of patients at risk of stroke and myocardial infarction would necessitate both clinical examinations of the limb and neck vessels but must include DUS assessment of these vessels to allow appropriate assessment of their risks and help to plan, monitor treatment, and follow-up. 
| Conclusion|| |
DUS is a useful tool for timely evaluation of vascular lesions. Despite the siting of sonographic equipment outside a hospital setting, it has been found to be useful for assessment of vascular lesions and patients are able to access it in such a way to provide useful addition to their management.
Staff at Sharon Diagnostics Benin City.
Financial Support and Sponsorship
Conflicts of Interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]