1/42. Congenital vertebral anomalies in ischiopagus and pyopagus conjoined twins.A review of clinical records and radiographs revealed that five of 10 patients with conjoined twinning (three of six ischiopagus and two of two pyopagus twins) had congenital vertebral anomalies including hemivertebrae (3), multiple thoracic anomalies (1), right hemisacral agenesis (1), and three lumbar vertebra (1). No mirror image anomalies were identified, and different regions of the spine were involved in the two cases in which both twins had anomalies. Coexisting visceral and musculoskeletal anomalies included dextrocardia (3), atrial septal defect (1), congenital vertical talus (2), Sprengel's deformity (1), and multiple unilateral foot anomalies (1). hip subluxation or dislocation was seen in five of eight ischiopagus or pyopagus twins after separation and required femoral and pelvic osteotomies. Lumbar scoliosis not associated with congenital vertebral anomalies was seen in two ischiopagus twins. These observations suggest an association between ischiopagus and pyopagus conjoined twins and congenital vertebral anomalies, and their coexistence is explained best by a nonspecific teratogenic insult during early embryogenesis.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
2/42. Epigastric heteropagus twins--a report of four cases.Asymmetrical conjoined twinning is an extremely rare congenital anomaly constituting only 1%-2% of all conjoined twins. In epigastric heteropagus twins (EHT), the dependent portion (parasite) is smaller than the host (autosite). The embryopathy is related to incomplete cleavage of the embryo at 2 weeks of gestation. However, some form of ischaemic insult in early gestation leads to selective atrophy of the cranial part of one of the monozygous twins. We report our experience with four cases of EHT and a review of the literature with a discussion of possible embryopathy.- - - - - - - - - - ranking = 3keywords = embryo (Clic here for more details about this article) |
3/42. Parasitic conjoined twins: a case report.Parasitic twins are a rare phenomenon and a challenge for caregivers. Occurring as a result of abnormal processes in the first several weeks of embryologic development, this condition is oftentimes diagnosed by prenatal ultrasound. This unusual condition may go undiagnosed until the time of delivery, however, despite the availability and use of advanced ultrasound techniques. The challenges presented by this condition are multiple and complex. The following case report demonstrates some of these challenges.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
4/42. Parasitic omphalopagus complicated by omphalocele and congenital heart disease.Conjoined twins occur in approximately one of every 50,000 to 200,000 births. Atypical or parasitic conjoined twins result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Omphalopagus refers to conjoined twins joined at the level of the umbilicus. The authors report a case of atypical omphalopagus involving an acardiac, acephalic, parasitic twin and a host twin with a large omphalocele, transposition of the great arteries, and aortic coarctation. The authors briefly review reported cases of parasitic omphalopagus and emphasize the role of intensive neonatal care, preoperative planning, and staged surgical intervention in the successful management of complicated variants.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
5/42. Multiple fetuses in fetu:imaging findings.fetus in fetu is an extremely rare developmental abnormality secondary to abnormal embryogenesis in a diamniotic monochorionic pregnancy. It occurs when a vertebrate fetus is enclosed within the abdomen of a normally developing fetus. This report describes the prospective diagnosis of fetus in fetu by findings on a plain radiograph and CT scan. At surgery, two fetus in fetu were discovered.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
6/42. Unusual cardiac malformations in conjoined twins: thoracopagus twins with conjoined pentalogy of cantrell and an omphalopagus twin with atretic ventricles.Two unrelated cases of conjoined twins were found to have cardiac malformations that apparently have not been reported previously. In one case, thoracopagus twins had an extensive thoracoabdominal wall defect that resulted in ectopia cordis of a conjoined heart along with evisceration of the shared liver and intestine along with one spleen. These malformations, accompanied by defects in the sternum, diaphragm, and supraumbilical abdominal wall, constitute a conjoined pentalogy of cantrell. In the second case, the heart of one of omphalopagus twins consisted of a solid ventricular mass with only a minute aortic cavity but no atrioventricular communication-an ineffective heart that could develop only in a conjoined or chorioangiopagus twin. In both cases, a common atrium lay in the primitive (embryologic) position caudal to the ventricles.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
7/42. Conjoined twins: morphogenesis of the heart and a review.Five cases of conjoined twins have been studied. These included three thoracopagus twins, one monocephalus diprosopus (prosop = face), and one dicephalus dipus dibrachus. The thoracopagus twins were conjoined only from the upper thorax to the umbilicus with a normal foregut. These three cases shared a single complex multiventricular heart, one with a four chambered heart with one atrium and one ventricle belonging to each twin with complex venous and arterial connection; two had a seven chambered heart with four atria and three ventricles. The mono-cephalus diprosopus twins had a single heart with tetralogy of fallot. The dicephalus twins had two separate axial skeletons to the sacrum, two separate hearts were connected between the right atria with a shared inferior vena cava. Thoracopagus twinning is associated with complex cardiac malformations. The cardiac anlagen in cephalopagus or diprosopus are diverted and divided along with the entire rostral end of the embryonic disc and result in two relatively normal shared hearts. However, in thoracopagus twins the single heart is multiventricular and suggests very early union with fusion of the cardiac anlagen before significant differentiation. Cardiac morphogenesis in conjoined twins therefore appears to depend on the site of the conjoined fusion and the temporal and spatial influence that determines morphogenesis as well as abnormally oriented embryonic axes.- - - - - - - - - - ranking = 2keywords = embryo (Clic here for more details about this article) |
8/42. Conjoined twins in a triplet pregnancy: early prenatal diagnosis with three-dimensional ultrasound and review of the literature.We report two cases of conjoined twins complicating a triplet pregnancy diagnosed by two-dimensional ultrasound in the first trimester and evaluated further by three-dimensional ultrasound. A review of the literature over the last 30 years revealed 11 other cases diagnosed prenatally by ultrasound. overall, three (23%) of these 13 pregnancies were achieved by assisted reproductive techniques and 10 (77%) were diagnosed before 18 weeks. Four women opted for termination of the whole pregnancy and three were managed expectantly, with two delivering before 32 weeks. Two monochorionic pregnancies underwent selective feticide with intrauterine demise of the non-conjoined fetus in both cases. All four dichorionic pregnancies undergoing selective termination or spontaneous embryo reduction to singleton in the first trimester resulted in term delivery of the non-conjoined fetus. The rare condition of conjoined twins in a triplet pregnancy poses a significant obstetric challenge from both diagnostic and management points of view. Accurate determination of chorionicity in these cases plays a critical role in determining management and outcome.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
9/42. Separation of craniopagus twins in the era of modern neuroimaging, interventional neuroradiology, and frameless stereotaxy.INTRODUCTION: Craniopagus twinning is a rare embryological event occurring in 1 in 2.5 million births. CASE REPORT: We present our recent experience with the separation of total vertical craniopagus twins in the modern era of neuroimaging and interventional neuroradiology. Three-dimensional CT images revealed the twins' heads were axially rotated 30 degrees. MRI showed deficient dura between the brains of the twins, and some sharing of parietal brain tissue. cerebral angiography showed a dominant arterial circulation of one twin with unilateral middle cerebral artery (MCA) branches feeding the other twin. The twins shared a common superior sagittal sinus in its middle segment where a circular sinus was formed. Prior to surgery, endovascular separation of the twins' arterial and venous circulations was achieved in part using tantalum coils for the MCA feeders in one twin, and balloon occlusion of the anterior superior sagittal sinus of the other. Using the ISG wand intraoperatively, surgery proceeded stepwise and included the circumferential removal of bone and opening of the dura, separation of the twins' brains along leptomeningeal planes, and identification of the major draining veins from the superficial cerebral cortex. DISCUSSION: The separation of craniopagus twins demands a multidisciplinary team approach. Utilizing preoperative neuroendovascular techniques to occlude shared vascular anastomotic channels, complex total vertical craniopagus twins can now be successfully separated in a one-stage procedure.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
10/42. Craniopagus twins: embryology, classification, surgical anatomy, and separation.INTRODUCTION: With recent advances in brain imaging and neurosurgical techniques, there has been a renewed interest in the surgical separation of craniopagus twins. Successful separation in recent cases, along with widespread publicity, has attracted craniopagus twins from all over the world to be referred to pediatric neurosurgical centers for evaluation and consideration for surgical separation. SEPARATION OF blood SUPPLY: It has become apparent, however, that the most critical decisions in surgical planning are related to separation of the blood supply to the conjoined brains. In fact, in craniopagus twins that survive pregnancy or the first few days of life, there is usually little shared brain tissue. The shared blood supply is far and away the more critical issue. It is very difficult to successfully separate craniopagus twins in one surgical procedure. Staged separation, with gradual re-routing of the shared blood supply, has been a successful alternative. CASE STUDIES AND DISCUSSION: We discuss here our experience with three sets of craniopagus twins and our approach to staged separation.- - - - - - - - - - ranking = 4keywords = embryo (Clic here for more details about this article) |
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