| dc.description.abstract | This is a retrospective study designed to obtain information on the demographic characteristics, risk factors, site of thrombosis in the lower limb, and the presence or absence of thrombi in patients who are referred for suspected deep venous thrombosis (DVT). The study was based at the KNH. and VON radiology departments in the period between April 2000 and January 200 l. Venous Doppler ultrasound was used as the mode of imaging. In most centres worldwide venous Doppler ultrasound has been adopted as the initial screening method for deep venous thrombosis (DVT) of the lower extremity. Because of the non-hazardous nature of US, this imaging modality allows repeated examinations to be done sometimes in one sitting and this has greatly increased its accuracy. The deep venous examinations were done using a combination of grey- scale imaging, color flow imaging and spectral Doppler methods. A total of 299 patients reports were analyzed: of these 70 were males (23.4%) and 229 were females (76.6%), with a female to male ratio of 3:·1.124 of the sampled patients were from the University of Nairobi, Department of Radiology and the rest from Kenyatta National Hospital. This is a much higher ratio compared to other centers that report a 2:1 ratio. The ages ranged between 13 years to 82 years (mean 41 ± 5) years. 121 of the patients were below 40 years (42.1 %). This is a lower percentage compared to other studies. (8,12) The main clinical features were of swelling alone 42.8%, pain alone 27.8%, swelling, pain and warmth 24.4%. Chest pain, numbness and suspected pulmonary thrombo-embolism made up a small percentage.
The left lower limb was involved in 65.9% of the patients, the right lower limb in 20.1 % and involvement of both lower limbs occurred in 14% of the patients. There is yet no satisfactory explanation as to why it was more common in the left lower limb. Positive radiological diagnosis of presence of thrombi was made in 42.1 % while the rest 57.9% were negative. This indicates the low clinical suspicion of deep venous thrombosis as already noted in other studies. (5,8) • The location of the thrombi was also an important objective of this study: 38.9% of the thrombi were found in the popliteal veins; 29.4% in the common and superficial femoral veins combined; 22.2% in the external iliac vein; 7.1 % in the three calf veins combined and 2.4 % of the patients showed extensive thrombosis involving external iliac vein the common iliac vein, superficial femoral vein and popliteal vein. In one case there was extension of thrombi into the short saphenous vein. In most of the females the thrombi was identified in the popliteal vein followed by the femoral veins then the calf veins. In the male patients, the distribution followed the same pattern. Relevant clinical history was not indicated in the majority of cases (25.1 %), while in the rest, there were predisposing factors as indicated in the result tables. Use of hormonal contraception played a major role in the clinical history followed by sudden onset of leg swelling. Presence of varicose veins was a major diagnostic enigma in the clinical history provided in the referral notes. The risk factors in this study compare well with those done in other centers. (7-12,17-35)
The role of DVT in the causation of pulmonary thromboembolic disease was not well documented in most of the referral clinical notes. Only 2% of the patients had clinical suspicion of PTE. However, from literature review of studies done in other centers, DVT has been identified as a source of pulmonary emboli.. (2,3,12) The choice of venous Doppler ultrasound as the imaging modality was made on the basis of the very high sensitivity and specificity of results as documented in many other centres. (18-20) | en_US |
