Wednesday, November 14, 2012

Microvascular filtration is increased in the forearms of patients with breast cancer-related lymphoedema.

Microvascular filtration is increased in the forearms of patients with breast cancer-related lymphoedema.

Nov 2012


1Bispebjerg University Hospital.


Breast cancer related lymphedema (BCRL) is a frequent and debilitating complication to breast cancer treatment. The pathophysiology is complex and remains poorly understood; however, data suggest that changes in the peripheral circulation may contribute to edema formation. In 13 volunteers with unilateral BCRL the following aspects of upper extremity peripheral circulation were examined: Muscle relative microvascular volume, capillary filtration coefficient, central- and local sympathetic vascular reflexes, skin blood flow and forearm blood flow. This was studied by: Real-time contrast enhanced ultrasound, venous occlusion strain gauge plethysmography, lower body negative pressure, non-invasive blood pressure measurements and skin (99m)Tc-pertechnetate clearance technique. 

Measurements were performed bilaterally and simultaneously in the forearms enabling the use of the non-edematous forearm as a control. Capillary filtration coefficients were additionally measured in healthy age-matched controls. The Capillary filtration coefficient was 7.98±2.52 μL100mL(-1)mmHg(-1)min(-1) (mean±SD) in the edematous forearms and 6.09±1.83 in the non-edematous forearms in the patient group. The Capillary filtration coefficient was 3.32±1.17 μL100mL(-1)mmHg(-1)min(-1) in the forearms of healthy controls, significantly less than the both the edematous- and non-edematous forearms of the patient group. 

No significant differences were found in muscle relative microvascular volume, forearm blood flow , central- or local sympathetic vascular reflexes. Forearm microvascular filtration is increased in patients with BCRL, and more so in the edematous arm.

The vascular sympathetic control mechanisms seem to be preserved.

We propose that the increased capillary permeability may be due to low-grade inflammation promoted by reduced clearance of inflammatory mediators.