[Small-diameter portosystemic shunts: indications and limitations]
Angel Mercado M. Granados-Garcia J. Barradas F. Chan C. Contreras JL. Orozco H. Angel-Mercado M.
Clinica de hipertension portal, Instituto Nacional de la Nutricion Salvador Zubiran, Mexico, D.F.
Low diameter porto-systemic shunts for the treatment of portal hypertension bleeding have emerged as a consequence of the technical development of vascular grafts (PTFE) that allow the use of a narrow lumen. The experience with this kind of operation at the Instituto Nacional de la Nutricion Salvador Zubiran, Mexico City during a 6-year period is reported. There were twenty-seven patients with good liver function (Child-Pugh A-B) were operated or electively, average Age 47.5 years (range 17-71), twenty three patients with liver cirrhosis, one with portal fibrosis and three with idiopathic portal hypertension. Operative mortality: 4%. Rebleeding: 14%. Postoperative encephalopathy was observed in 14 of 27, three of them being grade III-IV (11%). In the remaining 11 cases, it was mild and easily controlled. Postoperative angiography showed shunt patency in 81% of the cases; in 33% of the cases, portal vein diameter reduction was shown, as well as two cases with portal vein thrombosis. In 77% of the cases, adequate postoperative quality of life was observed. Survival (Kaplan-Meier): 86% at 12 months and 56% at 60 months. These kinds of shunts are a good alternate choice for patients considered for surgery, in which other portal blood flow preserving procedures (selective shunts, devascularization with transection) are not feasible.
[Neuronal migration disorders]
Departamento de Neurologia Pediatrica, Hospital General Centro Medico Nacional La Raza, Instituto Mexicano del Seguro Social, Mexico, D.F.
Neuronal migration disorders represent a group of congenital nervous system malformations that affect the process whereby millions of neuroectodermic cells move from germinal matrix to the loci, where they will reside for life. They produce important changes in cytoarchitecture, lamination and normal neuronal physiology, particularly in cerebral cortex. These disorders appear as sporadic cases, genetically determined or caused by external agents as infections, intoxications and radiations, etc. The better identified nosological entities include: schizencephaly, lissencephaly, pachygyria, polymicrogyria, neuronal heterotopias and agenesis of corpus callosum. Patients usually present early symptoms and signs of disease and epilepsy is a dominant manifestation. By means of studies of craneal computed tomography (CCT), magnetic resonance (MR), positron emission tomography (PET), single-photon emission computed tomography (SPECT) and immunohistochemical and Golgi studies (IHG), it has been recently shown that nervous system dysgenesis can be a frequent cause of many refractory epilepsies and epileptic syndromes considered as cryptogenic. When these disorders are associated with dismorphic stigmas, genetics syndromes such as Miller-Dieker, Zellweger and Aicardi should be suspected.