J Korean Soc Plast Reconstr Surg.  1998 Oct;25(7):1276-1283.

The effects of pentoxifylline of the flap tolerance to arterial and venous ischemia in the diabetic rats

• No authors listed

Abstract

Skin flaps are less tolerant to secondary ischemia thant o primary ischemia after the free tissue transfer. Although microvascular procedures are not contraindicated in the patients with diabetes, postoperative venous occlusion is common and the flap tolerance to secondary ischemia is decreased in the diabetic patients. Pentoxifylline effectively lowers blood viscosity and therefore has a salutary effect on teh movement of blood especially within small vessels. To the best of our knowledge, the effects of pentoxifylline on the flap tolerance to the ischemia caused by arterial and venous occlusion have not been evaluated in the diabetic animal. The purpose of this study is to evaluate the effects of pentoxifylline on the flap tolerance to secondary arterial and venous ischemia in the diabetic rats. Fifty-eight male Sprague-Dawley rats weighing average 250 g were used. The rats were randomly divided into eight groups : normal arterial ischemia (NA), normal venous ischemia (NV) normal arterial with pentoxifylline (NAP), normal venous ischemia with pentoxifylline (NVP), diabetic arterial ischemia (DA), diabetic venous ischemia (DV), diabetic arterial ischemia with pentoxifylline (DAP), diabetic arterial ischemia with pentoxifylline (DVP). Diabetes was induced by an intravenous injunction of streptozotocin (50 mg/Kg) through the penile vein. Blood glucose levels an body weight changes were monitored every other days. Blood glucose levels were maintained between 250 to 450 mg/dl. The pentoxifylline treated groups received intraperitoneal injection of pentoxifylline (10 mg/kg) twice a day. Four weeks after induction of diabetes and pentoxifylline administration, a 5 x 3 cm sized island skin flap was made on the right abdomen. The epigastric pedicle was occluded for 1 hour by microvascular clamps. Eighteen hours after reperfusion, the pedicle was reoccluded for 6 hours and then the flap was reperfused. AT the seven days after secondary ischemia, percentage of flap survival was assessed by computerized planimetry (image) The results were as follows : 1. The flap survival fates were significantly decreased in the diabetic rats compared to those in the normal rats (p< 0.05). 2. Venous ischemia was more detrimental than arterial ischemia in the flap survival (p< 0.05). 3. Pentoxifylline administration improved flap survival rats significantly in the diabetic rats (p< 0.05) but not in the normal rats. (p> 0.05).4. The erythrocyte deformability was decreased significantly in the diabetic rats compared to that in the normal rats (p< 0.05). 5. The erythrocyte deformability was increased significantly in the groups given pentoxifylline (p< 0.05). These results demonstrate that pentoxifylline improved erythrocyte deformability and flap tolerance to secondary ischemia in the diabetic rats. On the basis of this experiment, we recommend the administration of pentoxifylline to the diabetic patients who is anticipating free flap surgery to prevent the flap necrosis after microvascular thrombosis.

MeSH Terms

Abdomen
Animals
Blood Glucose
Blood Viscosity
Body Weight Changes
Erythrocyte Deformability
Free Tissue Flaps
Humans
Injections, Intraperitoneal
Ischemia*
Male
Necrosis
Pentoxifylline*
Rats*
Rats, Sprague-Dawley
Reperfusion
Skin
Streptozocin
Thrombosis
Veins
Blood Glucose
Pentoxifylline
Streptozocin