Microsurgery: Transplantation and Replantation by Harry J. Buncke, MD, et al.
  Table of Contents / Chapter 36:

Bupivacaine,3,14 lidocaine,20,31 magnesium sulfate,20 papaverine,20,22 and chlorpromazine 20 are commonly applied topically to relieve vasospasm. These agents appear to have reproducible effects experimentally and clinically. The ability of lidocaine to preserve the volume of blood flow as well as to prevent vasospasm in small vessels following microvascular repairs has been demonstrated in a rat model.21 Bupivicaine and lidocaine are used in continual brachial plexus and regional blocks to produce sustained vasodilation. 24,25,73

Numerous systemic vasodilators have been investigated clinically and experimentally, with no agent achieving a status of clear efficacy or widespread use. British reports describe intraoperative administration of sodium nitroprusside28 or thymoxamine27 intraoperatively with a decrease in observable vasospasm. Postoperative of systemic chlorpromazine32,74 and isoxuprine1 are part of the routine postoperative care of some reported microsurgical series, but their use has not been shown to be critical for success. Anecdotally, intravenous guanethidine,75 intra-arterial papaverine,4 and intra-arterial reserpine7 have been given to reverse apparent impending microvascular failure.

Experimental attempts to find roles for modifiers of prostaglandin function,14,18,76 sympatholytics,60,77-79 calcium channel blockers,80 and numerous other drugs81 have generally not succeeded in producing either clearly applicable models or reproducibly positive results. Eddy et al. 82 impregnated microvascular suture with a prostaglandin analog and decreased venous thrombosis in a microvascular rat model. Incorporation of locally active agents into sutures may be a promising new research area.



Experimentally, anemia appears to promote skin flap survival.83,84 This observation suggests that decreased blood viscosity enhances flap survival, and dextran is used in this context, as well as for its reputation (acquired in vascular surgery) as a volume expander and platelet inhibitor.7 A fibrinolytic, ancrod, experimentally decreases viscosity and increases flap perfusion in dogs.85 Pentoxifylline86 and pluoronic F68 7,87 have had some experimental successes in promoting tissue survival or vascular patency.

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