Current peripheral bypass surgery: various clinical studies

Abstract

Substantial post-operative edema occurs in the majority of patients who undergo peripheral bypass surgery due to severe peripheral arterial disease (PAD). The pathophysiological mechanisms that underlay edema formation following peripheral bypass surgery include hyperemia, an increased capillary permeability, reperfusion associated injury, lymphatic and venous disorders. Preventive and treatment strategies of post-operative edema include the administration of anti-oxidative drugs, lymph sparing surgical techniques, lymphatic massages and application of compression stockings (CS). Intermittent pneumatic compression (IPC) can be used to treat edema of various origins. Leg edema can be quantified by assessing leg circumferences. A method based on tape measures was tested for reliability and reproducibility. Intra-class correlation coefficients of repeated measures can be as high as 0.94 in the short-term (one week) and 0.82 in the long-term (three months) respectively. The use of tape measure can be considered a suitable method to perform repeated circumferential measurements. The effects of IPC on leg edema, inflammatory parameters (leukocytes and C-reactive protein) and quality of life (QoL) in patients following femoropopliteal bypass surgery were investigated in a single center randomized controlled trial (RCT). In this trial the use of IPC was compared to the use of CS following either autologous or polytetrafluoroethylene (PTFE) femoropopliteal bypass surgery. Leg circumference increased on day 1 (CS:-0.4%/IPC:2.7%), day 4 (2.1%/6.1%), day 7 (2.5%/7.9%), day 14 (4.7%/7.3%) and day 90 (1.0%/3.3%) from baseline (pre-operative situation) following autologous bypass surgery. Following PTFE femoropopliteal bypass surgery limb circumference increased post-operatively on day 1 (CS:1.5%/IPC:1.4%), on day 4 (5.7%/6.3%), on day 7 (6.6%/6.1%), on day 14 (7.9%/7.7%) and on day 90 (5.8%/5.2%). A re-operation gave a significant 3.9 % increase in circumference as compared to a first operation. Inflammatory parameters increased significantly following both autologous and PTFE bypass surgery. The use of IPC resulted in significant more edema than the use of CS’s following autologous femoropopliteal bypass surgery. However, this effect was not seen in patients who underwent PTFE femoropopliteal bypass surgery. QoL measurements were taken from the patients mentioned above with the abbreviated version of the World Health Organization QOL assessment instrument (WHOQOL-BREF). At baseline significant differences in General health were detected in the disadvantage of patient who underwent PTFE femoropopliteal bypass surgery. Of all domains, the domain of Physical health was the most affected in patients suffering from severe PAD. Following peripheral bypass surgery, significant increases were detected on the domain of Physical health at two weeks and at three months. No effects of the bypass type could be detected on the changes in QoL. A study in which magnetic resonance imaging (MRI) was used in patients prior to and following autologous peripheral bypass surgery revealed that leg edema is mainly located in the subcutaneous compartment. Minor edema-like changes were detected in muscles. The swelling of the subcutaneous compartments was very alike to edema as seen in patients suffering from lymphatic diseases. Especially lymphatic disruptions are likely to cause postoperative edema. However, the presence of fluid accumulation in muscles might be suggestive for reperfusion associated injury.