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 Scientific Basis for Balloon Embolectomy

Mechanics of balloon embolectomy

  • Lateral wall pressure.
  • Balloon pressure versus lateral wall pressure.
  • Balloon-artery shear forces.
  • Histologic effects of embolectomy.

Determinants of lateral wall pressure and shear forces

  • Catheter size.
  • Brands of catheters.
  • Balloon eccentricity.
  • Fluid-filled versus gas-filled balloons.
  • Syringe size.
  • Velocity of catheter motion.
  • Blood in the vessel lumen.
  • Inflating balloons at rest and during catheter motion.

Balloon embolectomy induced injuries

References

Dobrin PB. Mechanisms and prevention of arterial injuries caused by balloon embolectomy. Surgery 1989;106:457-466.

This article reviews the spectrum of clinical injuries produced by balloon embolectomy The concepts of lateral wall pressure and balloon-artery shear force are presented, and the histologic reactions to passage of embolectomy catheters are described. On the basis of the results of experimental investigations, technical recommendations are made regarding the performance of embolectomy in patients.

Jorgensen RA, Dobrin PB. Balloon embolectomy catheters in small arteries. IV. Correlation of shear forces with histologic injury. Surgery 1983;93:798-808.

The aim of this experimental study was to evaluate the character and time course of arterial injury caused by balloon embolectomy catheters. Shear forces of up to 30 gm caused no injury, while shear forces of 60-120 gm caused stripping of the endothelium which was completely repaired by myointimal proliferation within 6 months. Two hundred gram initial force caused intimal injury and fracturing of the internal elastic lamina, with the latter injury persisting even after 6 months.

Dobrin PB, Jorgensen RA. Balloon embolectomy catheters in small arteries. III. Surgical significance of eccentric balloons. Surgery 1983;93:402-408.

This study was undertaken to compare balloon eccentricity in air with that which occurs in arteries, to determine the influence of balloon eccentricity on shear force, and to estimate the injury potential of eccentric balloons. The presented data suggest that balloon eccentricity in air is an accurate indicator of balloon eccentricity within arteries, that moderately eccentric balloons are acceptable for clinical use, but that extremely eccentric balloons may cause severe injury and should not be used in the operating room.

Dobrin PB. Balloon embolectomy catheters in small arteries. II. Comparison of fluid-filled and gas-filled balloons. Surgery 1982;91:671-679.

Balloon embolectomy catheters were studied in canine common carotid arteries (2 to 3 mm) in vitro to evaluate a technique of preventing excessive shear forces and to examine the effect of blood within the lumen. From these studies it is recommended that during embolectomy in patients the balloons be distended during the first half centimeter or centimeter of catheter withdrawal to prevent excessive shear forces and that residual blood in the vessel lumen proximal to the point of embolic obstruction be accepted without concern, provided adequate heparinization has been achieved.

Dobrin PB. Balloon embolectomy catheters in small arteries. I. Lateral wall pressures and shear forces. Surgery 1981;90:177-185.

This article presents data from balloon embolectomy experiments in 2 to 3 mm canine arteries in vitro. These data suggest that every effort should be made to achieve the low LWP since this strongly influences shear force; the smallest effective catheter should be used and that negligible benefit may be gained if catheters are withdrawn at moderate velocities.

Posted June 2010