Perfusão arterial reversa gemelar: revisão da literatura / Twin reverse arterial perfusion: literature review

A perfusão arterial reversa gemelar é uma anormalidade rara que pode ocorrer em gestações gemelares monocoriônicas. Consiste em uma alteração na circulação fetoplacentária, com desvio de sangue de um dos gemelares para o outro, por meio de anastomoses arterioarteriais e venovenosas na superfície placentária e anastomoses arteriovenosas em áreas de circulação placentária compartilhada. O feto bombeador pode desenvolver insuficiência cardíaca devido ao aumento do débito cardíaco, e o feto receptor, perfundido por sangue pobre em oxigênio por meio do fluxo reverso, é severamente malformado, incompatível com a vida extrauterina. Este artigo apresenta o caso de uma gestação gemelar monocoriônica diamniótica, com manejo clínico conservador. O objetivo é relatar um caso de complicação rara de gestações monozigóticas e revisar condutas para diagnóstico e manejo adequado.(AU)

Twin reverse arterial perfusion is a rare abnormality that can occur in monochorionic twin pregnancies. It consists of an alteration in the fetal-placental circulation, with blood diversion from one of the twins to the other, through arterio-arterial and veno- venous anastomosis on the placental surface and arterio-venous anastomosis in areas of shared placental circulation. The pumping fetus may develop heart failure due to increased cardiac output, and the recipient fetus, perfused by oxygen-poor blood through reverse flow, is severely malformed, incompatible with extrauterine life. This article presents the case of a monochorionic diamniotic twin pregnancy, with conservative clinical management. The objective is to report a case of rare complication of monozygotic pregnancies and review procedures for diagnosis and adequate management.(AU)

The inferior mesenteric artery arising as a persistence of the ventral longitudinal anastomosis: A rare anatomical variation

Routine dissection of an 82-year-old cadaver demonstrated the inferior mesenteric artery arising from two roots: one from the coeliac trunk, and the other from the superior mesenteric artery. There was no discrete connection between the inferior mesenteric artery and the aorta. This variant artery gave off its characteristic branches, including left colic and sigmoidal branches.This can be explained as an abnormal persistence of the ventral longitudinal anastomotic channel. Furthermore, an understanding of the breadth of variations of mesenteric vasculature is essential to surgeons and proceduralists of the gastro-intestinal tract, and may have implications in cancer, retroperitoneal and endovascular surgery

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Intracranial arterial variations: a comprehensive evaluation using CT angiography.

Background Intracranial arterial variations are a frequent finding in the general population. Knowledge of these vascular variations has significant clinical impact because some of them predispose patients to development of an aneurysm or cerebrovascular ischemic disease. The purpose of this study was to evaluate the frequency of intracranial vascular variations and associated vascular lesions on computed tomography angiography (CTA) examinations. Material and Methods CTA examinations performed by 16-detector computed tomography were prospectively reviewed in 455 patients for the presence of fenestrations, duplications, hypoplasia, aplasia, aneurysms, and other vascular lesions. Results Arterial fenestrations were found in 2.4% of patients, with the vertebrobasilar system as the most common location. The remaining fenestrations were located on the middle cerebral artery M1 segment (0.2%), anterior communicating artery (0.4%), and anterior cerebral artery A1 segment (0.6%). No associated aneurysms were noted in these patients. The prevalence of an azygos anterior cerebral artery was 1.5%. Bihemispheric anterior cerebral artery was found in 0.9%, hypoplastic A1 segment in 17.6%, and congenital absence of A1 segment in 0.4% of patients. Fetal origin of the posterior cerebral artery was found in 37% of cases. Hypoplastic vertebral artery terminating as posterior inferior cerebellar artery was observed in 9 patients, while transversal anastomosis between vertebral arteries was seen in only 1 patient. Conclusions CTA precisely demonstrates the diversity of intracranial arterial variations, whose overall frequency in this study is similar to previous radiological reports. Furthermore, our results do not show significant association between the frequency of aneurysms and cerebral arterial anomalies.

Optociliary shunt vessels in compressive optic neuropathy by the intracranial internal carotid artery.

PURPOSE: To report a clinical case of optic nerve compression by supraclinoidal internal carotid artery associated with optociliary shunt vessels. METHODS: A 78-year-old woman with the clinical triad of left visual loss, ipsilateral optic disc pallor, and retinochoroidal (optociliary) shunt vessels is reported. She complained of loss of vision in the left eye of 2 years'' duration. RESULTS: A diffuse depression of the visual field was found in the affected eye. Magnetic resonance imaging revealed left optic nerve compression by the supraclinoidal internal carotid artery. CONCLUSIONS: The occurrence of optociliary shunt vessels, visual loss, and optic atrophy is a nonspecific sign of chronic optic nerve compression and in some instances may be falsely localized.

Malformaciones vasculares abdominales y síndrome de Down / Abdominal vascular malformations and Down syndrome

Las malformaciones del sistema venoso abdominal son alteraciones vasculares raras. Se asocian a otras malformaciones y, ocasionalmente, se han descrito asociadas a alteraciones cromosómicas como la trisomía 21. Son probablemente las malformaciones congénitas vasculares más frecuentes en el síndrome de Down. El diagnóstico prenatal permite un seguimiento precoz y un tratamiento temprano de las complicaciones. Presentamos un caso de síndrome de Down con una malformación venosa abdominal asociada, diagnosticada en el primer trimestre de gestación

Malformations of the abdominal venous system are rare vascular disorders. These entities are associated with other malformations and with chromosomal anomalies such as trisomy 21. Abdominal venous malformations are probably the most frequent congenital vascular malformations in Down syndrome. Prenatal diagnosis allows the early follow-up and treatment of complications. We present a case of Down syndrome associated with an abdominal venous malformation diagnosed at the first trimester of pregnancy

Feto acardio en aborto gemelar / Acardiac fetus in intrauterine fetal demise in a twin pregnancy

Se trata de una entidad poco frecuente que complica las gestaciones múltiples, en mayor medida las gemelares univitelinas, aunque puede afectar también a las monocoriales dicigóticas, las triples e incluso a embarazos únicos. La presencia del feto acardio supone una sobrecarga para el gemelo donante que tiene que mantener la perfusión propia y la del gemelo parásito. Se presenta el caso clínico de una paciente con gestación gemelar (no controlada) con diagnóstico de muerte fetal intraútero de ambos gemelos, uno de ellos un feto acárido (AU)

Acardiac fetus is a rare entity that complicates multiple pregnancies. Occurrence is more frequent in monozygotic twin pregnancies but monochorionic dizygotic, triple and even singleton pregnancies may also be affected. The acardiac fetus acts as a parasite on the pump twin, which must provide a blood supply for the perfused fetus. We present the case of a patient with a twin pregnancy (without prenatal monitoring) with a diagnosis of intrauterine fetal demise in both twins, one of which was an acardiac fetus (AU)

Partial anomalous pulmonary venous connection: correction by intra-atrial baffle and cavo-atrial anastomosis.

The creation of intracaval conduits to repair partial anomalous pulmonary venous connection of the right lung into the superior vena cava can be complicated by arrhythmias and superior vena cava and pulmonary vein obstruction. An intra-atrial baffle, combined with cavo-atrial anastomosis, has been proposed to avoid these complications. The authors report their recent experience with this operative technique. From January 1997 to December 2000, 7 patients with a mean age of 13.5 +/- 9 (2-31) years were operated according to this technique. Only one child did not have an associated atrial septal defect. The mean number of pulmonary veins connected to the superior vena cava was 2.5 +/- 0.5. The immediate postoperative course was uneventful for the seven patients. The mean follow-up was 20 +/- 17 months. No patient developed arrhythmia or superior vena cava or pulmonary vein obstruction at echocardiography. This surgical technique appears to constitute an attractive alternative when pulmonary veins drain abnormally into the superior vena cava above the cavo-atrial junction.

[Multiple aneurysms of the PICA communicating artery: a case report].

A case with unusual type of aneurysms in the distal posterior inferior cerebellar artery (PICA) is reported here. Though only two cases with a single aneurysm of the PICA communicating artery have been reported previously, the present case is the first one with multiple aneurysms in the PICA communicating artery. A 61-year-old woman with a sudden onset of severe headache, vomiting and unconsciousness was transferred to our hospital. CT scan revealed a hematoma in the fourth, third, and lateral ventricles, and a mild subarachnoid hemorrhage at the posterior fossa. Cerebral angiogram showed the right PICA supplying the hypoplastic left PICA territory through an anastomotic vessel. Two small aneurysms were seen at the tips of hairpin curves of an anastomotic vessel, "the PICA communicating artery". Suboccipital craniotomy was performed, and the ruptured aneurysm was clipped and the unruptured one was wrapped with cotton-sheet. After the operation, her clinical recovery went well and she was discharged on foot.

Hypoplasia of the internal carotid artery with intercavernous anastomosis.

We report a symptomatic case of unilateral hypoplasia of the internal carotid artery with an intercavernous anastomosis, a very rare developmental anomaly. The symptoms were caused by occlusion of the proximal middle cerebral artery which possibly related to the haemodynamic stress caused by the anomalous intercavernous anastomosis.

[True "PICA communicating artery" aneurysm: a case report].

We present an unusual case of an aneurysm of the distal posterior inferior cerebellar artery (PICA). A 51-year-old female presented a subarachnoid hemorrhage with mild consciousness disturbance on August 6, 1992. Computed tomography (CT) on admission showed subarachnoid hemorrhage with thick hematoma in the cisterna magna and intraventricular hematoma in the 4th, 3rd and both lateral ventricles. The angiogram on admission revealed no definite vascular anomalies. Repeated angiograms on the 11th day after onset showed an aneurysm on anastomotic branch between the bilateral distal PICAs. The aneurysm was clipped successfully through a suboccipital craniectomy 14 days after the onset. In the literature reviewed, only one such aneurysm, located at an anastomotic vessel of the bilateral PICAs, has been reported by Hlavin et al in 1991. They reported that the aneurysm was associated with a unilateral PICA that supplied both cerebellar hemispheres and arose from an anastomotic vessel in the contralateral circulation. They called the aneurysm as "a PICA communicating artery" aneurysm. We assume that this "PICA communicating artery" is a remnant of a primitive lateral vertebrobasilar anastomosis, which appears in the embryo at the 9 mm stage. It is suggested that the pathogenesis may be not only the hemodynamic factor but also a congenital anomaly.

Anastomosis anómala entre las arterias hepática y mesentérica superior / Anomalous anastomosis between the hepatic and superior mesenteric arteries

Variaciones anatómicas en las arterias de las regiones hepática y peripancréatica han sido descritas, en el 34 por ciento de los pacientes sometidos a angiografías preoperatorias del tronco celiaco y de la arteria mesentérica superior. Estas variaciones pueden complicar seriamente algunas intervenciones, como la cirugía laparoscópica, al alterar la disposición de los elementos en el hilio de los órganos; o hacer impracticable algunos actos quirúrgicos complejos, como el transplante hepático o la resección del páncreas. En este trabajo, presentamos un raro caso de anastomosis entre las arterias hepática y mesentérica superior. Este vaso anómalo, de trayecto tortuoso, dispuesto detrás del cuello del páncreas, mide 21 cms. de largo, presenta un calibre irregular y en la parte inicial de su trayecto da origen a las ramas gastroepiploica derecha y pancreático-duodenal superior. En el texto se discuten las posibles causas embriológicas que explican esta variación anatómica

Myocardial dysgenesis with persistent sinusoids in a neonate with Noonan's phenotype.

Structural cardiac anomalies indicative of primary myocardial maldevelopment are reported in a newborn girl with congenital heart block. The cardiac findings included disordered trabeculation of both ventricles with persistent intramyocardial sinusoids, hypoplastic papillary muscles, and dysplastic atrioventricular valves with partial downward displacement of the septal leaflet of the tricuspid valve. Dilatation of the ascending aorta and craniofacial dysmorphism including webbed neck, hypertelorism, and low-set ears raise the possibility of Noonan syndrome.

Isquemia cerebral transitória associada a artéria trigeminal persistente: relato de caso / Transient cerebral ischemia associated to persistent trigeminal artery: report of case

Uma paciente com artéria trigeminal persistente apresentou vários episódios de isquemia cerebral transitória, associada a ateroesclerose difusa, na circulaçäo anterior. O autor enfatiza a investigaçäo desta anomalia arterial em pacientes jovens com quadros isquêmicos, fazendo uma revisäo da embriologia e quadros clínicos apresentados