Ambulatory venous pressure studies and its correlation with CEAP grading of varicose veins

BACKGROUND: Venous hypertension in the lower limb is predisposing factor for the chronic venous insufficiency and resultant skin changes. In a normal limb, during ambulation, there is a fall in lower limb venous pressure as the calf muscle pump and unidirectional valvular activity propel the blood from the lower limbs to the heart. Failure of this mechanism results in ambulatory venous hypertension predisposing to chronic venous insufficiency. The current study aimed at studying the lower limb ambulatory venous pressure in varicose veins, its co-relation with clinical severity of the disease according to the clinical grading of clinical-etiological-anatomical-pathophysiological (CEAP) classification and whether these measurements can help in assessing the anatomical sites of incompetence. METHODS: A prospective study was carried out at a University Teaching Hospital in Northern India. Ambulatory venous pressure was measured in 67 limbs. Limbs were classified according to the CEAP grading. Four groups were divided as follows: group 1, CEAP-0 (7 limbs); group 2, CEAP-1, 2 (24 limbs); group 3, CEAP-3, 4 (21 limbs); and group 4, CEAP-5, 6 (15 limbs). Following the duplex scan, limbs were also grouped according to the anatomical sites of incompetence. For pressure measurement, dorsal foot vein was cannulated with a 20-gauge cannula and connected to a physiograph through a pressure transducer filled with heparinized saline. Patient performed a standard 10 tip-toe exercise and following parameters were assessed: resting pressure in the sitting and standing position, mean ambulatory venous pressure, maximum fall in pressure, percentage decrease in pressure, 50%, 75%, 90% recovery time, initial recovery rate, recovery in first 4 seconds, pressure relief index. RESULTS: Median ambulatory venous pressure showed a progressive increase from group 1 (18.0 mmHg) to group 2 (51.5 mmHg) to group 3 (69.0 mmHg) and group 4 (91.0 mmHg). Median recovery times for 50%, 75% and 90% recovery of pressure after cessation of exercise were significantly lower while the percentage recovery in first 4 seconds was significantly higher in the ulcer group. Median pressure relief index showed a significant stepwise decreasing trend from group 1 to group 4 (2790.0 mmHg-sec in group 1 to 534.0 in group 2 to 534.0 in group 3 to 40.0 in group 4; P<0.001). The prevalence of ulceration increased significantly with increasing median ambulatory venous pressure and decrease in time required for 90% recovery and median pressure relief index. None of the parameters showed significant variation among all the groups divided based on anatomical sites of incompetence. CONCLUSIONS: Ambulatory venous pressure measurement correlates with the clinical grading of the CEAP classification of varicose veins. Ambulatory venous pressure measurements do not help in determining the anatomical sites of incompetence. Pressure relief index, the recovery time intervals and the mean ambulatory venous pressure are the important parameters that can help in identifying and grading the severity of the disease.