Comparison of the ultrasonic scalpel to CO2 laser and electrosurgery in terms of tissue injury and adhesion formation in a rabbit model.

OBJECTIVE: To determine the relative effect of an ultrasonic scalpel on reproductive tissue compared with CO2 laser and electrosurgery. DESIGN: Prospective, randomized animal study. SETTING: University laboratory setting. ANIMALS: Sixteen New Zealand White rabbits. INTERVENTION(S): A steel scalpel, an ultrasonic scalpel, a CO2 laser, or electrosurgery were used to perform an ovarian wedge resection and to remove the distal uterine horn. A 3-cm longitudinal incision also was made in the uterine horn. MAIN OUTCOME MEASURE(S): The number of 1-second bursts of needle-tip electrosurgery required for hemostasis, the depth and degree of coagulation necrosis, degree of fibrin deposition, and postoperative adhesion formation. RESULT(S): The amount of electrosurgery needed to achieve hemostasis was less for any of the four power techniques than for the steel scalpel, with the exception of the ultrasonic scalpel at level 5 when used on the ovary. The depth (range: 0.30 to 0.38 mm) and the degree of coagulation necrosis was not different for any of the power techniques. The fibrin score was greatest for the ultrasonic scalpel at level 5 in both the ovarian tissue and the uterine tissue. There was no difference in adhesion scores for the power techniques and the steel scalpel. CONCLUSION(S): The ultrasonic scalpel at level 3 is not different from either CO2 laser or electrosurgery in terms of hemostatic properties, coagulation necrosis, or adhesion formation in the rabbit model.

Structural changes in the megakaryocytes of patients infected with the human immune deficiency virus (HIV-1).

Although immune mechanisms are known to be partially responsible for the thrombocytopenia of patients infected with HIV-1, an understanding of the mechanism underlying this disorder is incomplete. A casual observation that bone marrow biopsies of HIV-infected individuals seem to exhibit an unusually large number of denuded megakaryocyte nuclei (DN-MK) prompted a study comparing MK of 20 HIV-seropositive individuals with those of 10 patients with HIV-negative idiopathic thrombocytopenic purpura and 10 hematologically normal subjects. In normal marrows the number of DN-MK average 2.1 +/- 0.5 SE per 10 low power field. In patients with ITP the average number was 6.5 +/- 1.4 SEM, whereas HIV-ITP marrows had an average of 42.5 +/- 3.7 SEM. Electron microscopy of AIDS megakaryocytes exhibited ballooning of the peripheral zone to an extent not seen by us in any other myelodysplastic syndromes. These observations support the concept that the pathophysiology affecting MK/platelets in HIV-infection should not be equated with the destructive process underlying other immune thrombocytopenias.