RESUMEN
The dose-response effects of 6-h intravenous infusion of PGI2 (0, 5, 10, 25 or 75 ng/kg/min) or PGE1 (0, 25, 50, 100 or 300 ng/kg/min) on skin hemodynamics and viability were studied in 4 x 10 cm random pattern skin flaps (n = 24) raised on both flanks of the pig. Infusion of PGI2 or PGE1 was started immediately after intravenous injection of a loading dose 30 min before skin flap surgery. PGI2 infusion significantly (P less than 0.05) increased the total skin flap capillary blood flow at the dose of 10 ng/kg/min, compared with the control. However, the distance of blood flow along the skin flap from the pedicle to the distal end, i.e. perfusion distance, was not increased. Consequently, the length and area of skin flap viability was also not significantly increased. The effect of PGI2 infusion on skin blood flow was biphasic. Specifically, higher doses (greater than or equal to 25 ng/kg/min) of intravenous PGI2 infusion produced no beneficial effect on the skin flap capillary blood flow. PGI2 infusion at the dose of 10 or 75 ng/kg/min did not significantly increase plasma renin activities or plasma levels of norepinephrine compared with the control, therefore the biphasic effect of PGI2 on skin flap blood flow was not related to circulating levels of norepinephrine or angiotensin. Intravenous infusion of PGE1 did not produce any therapeutic effect on the skin capillary blood flow in the random pattern skin flaps at all doses tested. At the dose of 300 ng/kg/min, the mean arterial blood pressure was 17% lower (P less than 0.05) than the control, but the skin capillary flow still remained similar to the control. It was concluded that intravenous infusion of PGI2 or PGE1 was not effective in augmentation of distal perfusion or length of skin viability in the porcine random pattern skin flaps. Drug treatment modalities for prevention or treatment of skin flap ischemia is discussed.
Asunto(s)
Alprostadil/farmacología , Epoprostenol/farmacología , Piel/irrigación sanguínea , Colgajos Quirúrgicos , Animales , Presión Sanguínea/efectos de los fármacos , Temperatura Corporal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Frecuencia Cardíaca/efectos de los fármacos , Infusiones Intravenosas , Isquemia , Norepinefrina/sangre , Flujo Sanguíneo Regional/efectos de los fármacos , Renina/sangre , Piel/efectos de los fármacos , PorcinosRESUMEN
Three types of lateral groin flap have been applied to reconstruct the external genitals and to repair skin defects in the perineal region. A single lateral groin flap was used to construct a vagina for 2 patients who had congenital absence of vagina. A composite flap containing iliac crest bone was applied to reconstruct the penis in 11 patients: 8 suffered traumatic amputation and 3 had congenital micropenis. A coaxial pedicle flap of the lateral groin and abdominal area was used to repair skin defects of the penis and scrotum after resection of the elephantiasis caused by recurrent erysipelas in 2 patients, and to relieve postburn scar contracture in the perineal region in another. Using this operative technique, 14 flaps survived completely with satisfactory results; 70% of one composite flap was lost as a result of hematoma. In the single-flap group, the distal portion (3 x 5 cm) of one flap necrosed and was resected and resurfaced with a free skin graft; the final result was good.
Asunto(s)
Pene/cirugía , Perineo/cirugía , Colgajos Quirúrgicos/métodos , Vagina/cirugía , Adolescente , Adulto , Amputación Traumática/cirugía , Quemaduras/cirugía , Preescolar , Cicatriz/cirugía , Elefantiasis/cirugía , Femenino , Ingle , Humanos , Masculino , Pene/lesiones , Perineo/lesiones , Escroto/cirugíaRESUMEN
Clinically, ischemic necrosis is one of the most common complications in skin flap surgery, but the etiology is still unclear. The objective of the present experiments was to study the important role of the locally released noradrenaline in the pathogenesis of ischemic necrosis in acute and delayed random pattern skin flaps (4 x 10 cm) raised on both flanks of the pig. In Experiment 1, it was observed that 93, 96, and 94% of the skin contents of noradrenaline were depleted in skin flaps delayed for 2, 4, and 14 days, respectively, compared to the acute skin flaps (n = 8) raised in the same pig. Although the maximum depletion of noradrenaline in the delayed flaps occurred within 2 days of delay, significant (P less than 0.001) increase in the length of dye penetration in the delayed skin flaps was seen after 2 days of delay, compared to the acute skin flaps (n = 12). In Experiments 2 and 3, 5 days of intravenous phenoxybenzamine treatment, starting 2 days preoperatively and at the doses of 0.25, 0.5, 1.0, or 1.5 mg/kg/day, did not have any significant effect on the skin blood flow (n = 24) or viability (1 mg/kg/day; n = 32) in the acute skin flaps compared with the saline-treated control. Similarly, 5 days of intravenous phentolamine treatment (5 mg/kg/day) also did not have any significant effect on the skin blood flow (n = 24) or viability (n = 32) of acute skin flaps compared with the control.(ABSTRACT TRUNCATED AT 250 WORDS)