Dextran 40 in the treatment of peripheral vascular diseases

Dextran in Vascular Surgery

Dextran is a colloid, composed of chain of glucose molecules. These chains are formed by an enzymatic action of the bacteria leuconostoc mesenteroides on sucrose.1 The molecular weight of these molecules can be several millions, but to be used clinically it should not exceed 100.000. A decrease in the molecular weight can be accomplished by fractionation of the molecules. On the other hand the molecular weight should not be lower than about 40.000, in order to remain in the circulation for a reasonable length of time. Rheomacrodex®, or Dextran 40 has the lowest molecular weight of all dextran fractions used clinically.

In this review will be summarized the different indications of the use of dextran, and particularly Dextran 40, in vascular surgery, the rationale behind its use will be dis cussed, and the literature on this subject will be reviewed.

Does dextran 40 improve the early patency of autogenous infrainguinal bypass grafts?

PURPOSE

We determined whether the administration of dextran 40 would increase the early (30-day) patency of autogenous infrainguinal bypass grafts.

METHODS

During a 4-year period, 244 patients undergoing 273 autogenous infrainguinal bypass grafts were prospectively enrolled into and completed this study. Patients were randomized into two groups; one of the groups received a 72-hour infusion of dextran 40 after surgery, and the other did not. Comparisons were made between those patients who did and did not receive dextran 40 with respect to risks factors, demographics, and early graft patency.

RESULTS

One hundred twenty-six procedures were accompanied by the use of dextran; 147 were not. There was no significant difference between the two groups with respect to patient age, gender, perioperative risk factors, indication for surgery, or location of bypass graft (popliteal vs tibial). Among those patients receiving dextran, there were eight early occlusions (6.4%) and four deaths (3.2%); 89.7% of the patients were alive with patent grafts 30 days after surgery. In the group not receiving dextran, there were 10 early occlusions (6.8%) and 3 deaths (2%); 90.5% of the patients were alive with patent grafts 30 days after surgery. There was no significant difference between the two groups with respect to rate of early occlusion (p = 1.00), death (p = 0.71), or 30-day patency (p = 0.84).

CONCLUSIONS

The administration of dextran 40 does not increase the early patency of autogenous infrainguinal bypass grafts. Its routine use during these procedures cannot be recommended.

Colloids vs. crystalloids--a continuing controversy

The crystalloid vs. colloid controversy is based on a disagreement as to the most effective, safest, and most economical method of maintaining an effective plasma volume in shock patients. This review discusses Starling's law of fluid movement, with a definition of each term in the normal physiological state, and presents examples of how each component of Starling's law differs in the two major types of pulmonary edema: (1) cardiogenic and (2) noncardiogenic. The colloid-crystalloid literature is reviewed briefly with an emphasis on the major studies that support each side, and the deficiencies in each study. The arguments supporting each side of the crystalloid-colloid debate are then listed, with a summary that demonstrates the areas of agreement between the two schools of thought on fluid resuscitation. Each major colloid (albumin, dextran, hetastarch) and a representative crystalloid (lactated Ringer's) are discussed in terms of their chemistry; pharmacology and indications; and precautions, adverse reactions, and side effects. A table is included that summarizes the available products' data regarding composition, volume expansion, duration of expansion, half-life, metabolism, elimination, precautions, adverse reactions, and dose.