RESUMO
An experimental model for producing venous thrombosis was developed in end-to-end anastomoses of femoral veins in rats. The anastomoses were performed using a suture (9-0 suture-70 microns needle) with a knot 1 cm from the needle. The knot was formed by making either six or eight half-hitches in one throw of the suture. Vessel patency was assessed through the direct "milking test" at 20 min and 24 hrs. The incidence of thrombosis when using one knot with six half-hitches ranged from 20% to 40% and with eight half-hitches, from 50% to 70%. The incidence of femoral vein thrombosis varied directly with the presence and size of the knot. In this model, thrombosis was induced by exaggerating vessel injuries that may occur when performing routine microvascular anastomoses. This study demonstrates a reproducible thrombogenic model which mimics clinical practice and may be used to study the effects of local and systemic antithrombogenic agents.
Assuntos
Anastomose Cirúrgica/efeitos adversos , Veia Femoral , Técnicas de Sutura/efeitos adversos , Trombose/etiologia , Animais , Plaquetas/ultraestrutura , Modelos Animais de Doenças , Veia Femoral/patologia , Veia Femoral/cirurgia , Fibrina/ultraestrutura , Incidência , Masculino , Microscopia Eletrônica de Varredura , Microcirurgia/efeitos adversos , Ratos , Ratos Sprague-Dawley , Propriedades de Superfície , Suturas , Trombose/patologia , Fatores de Tempo , Túnica Íntima/ultraestrutura , Grau de Desobstrução VascularRESUMO
The rat gastrocnemius muscle can serve as a vascularized, innervated muscle transplant model. To establish the anatomic and technical details of this model, we performed ten gastrocnemius transplants and collected data on muscle weight, dimension, and vessel caliber from each muscle. The muscle, consisting of medial and lateral heads, is supplied by pairs of sural vessels averaging 0.2 mm in diameter. These vessels, however, can be taken in continuity with the femoral vessels (averaging 1.0-1.6 mm in diameter), which are used for transplantation. The muscles weighed an average of 2.8 g, and the average pedicle length was 24 mm. Eight of ten transplanted muscles were viable with intact circulation at 72 hr. The gastrocnemius transplant was technically reliable, and the muscle bulk and contour could allow biochemical and functional studies. Donor site morbidity limits this model to transplantation studies.
Assuntos
Músculos/transplante , Animais , Masculino , Microcirurgia/métodos , Músculos/anatomia & histologia , Músculos/irrigação sanguínea , Tamanho do Órgão , Nervo Fibular/anatomia & histologia , Nervo Fibular/cirurgia , Artéria Poplítea/anatomia & histologia , Artéria Poplítea/cirurgia , Veia Poplítea/anatomia & histologia , Veia Poplítea/cirurgia , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/anatomia & histologia , Nervo Isquiático/cirurgia , Retalhos Cirúrgicos/métodos , Nervo Tibial/anatomia & histologia , Nervo Tibial/cirurgiaRESUMO
Workup of a case of hypertrophic pyloric stenosis in a premature infant showed absence of ultrasonic criteria for diagnosis. Transpyloric intubation for enteral feeding may delay the diagnosis of this disorder and has been thought to play a role in its development.
