Conjoined twins occur in approximately 0.2:10,000 births; the obstetrician and sonographer only rarely examine them. In Western countries, discovery of conjoined twins is often made by the end of the first trimester; however, in the third world, conjoined twins are often discovered only at birth.
To evaluate how ultrasound techniques, when possibly available, may improve management and counseling when conjoined twins are confirmed.
Material and Methods
The authors report two different cases of union of two equal twins with sole umbilical cord.
The two cases presented with non contributive medical history and no prior teratogen exposure and an unfavorable prognosis.
Early discovery of viable conjoined twins permits assessment of the best route of delivery and a planning for serial sonography and fast MRI to plan eventual separation surgery or fetus after-birth surviving possibilities.
conjoined twins; ultrasound
Two pairs of omphalopagus twins were encountered at the Polish Mother's Health Institution in Lodz, Poland during the past 15 years. In the first set the prenatal diagnosis was not established and the delivery of the twins in a regional hospital was a complete surprise. Both babies died. In the second case the conjoined twins were diagnosed prenatally, surgical separation was successful, and both twins survived. The prenatal identification of conjoined twins is of cardinal importance for the planning of delivery and possible separation.
conjoined twins; prenatal diagnosis; surgical separation
This paper is written in response to controversial judicial decisions following separation surgery on conjoined twins "Jodie" and "Mary". The courts, it is argued, seem to have conceptualised the twins as "entangled singletons" requiring medical intervention to render them physically separate and thus "as they were meant to be", notwithstanding the death of the weaker twin, "Mary". In contrast, we argue that certain notions, philosophical and biological, of what human beings are intended to be, are problematic. We consider three compelling conceptualisations of conjoined twins and advocate a model that conceives them as two psychologically separate individuals who happen to share a body, the sharing of a body being integral to the individuality of each twin. While we reject an "essentialist" view of the conjoined state, a view which might render separation surgery unthinkable in all cases, we nevertheless argue against an "adversarial" interpretation of conjoined twins' respective best interests. We maintain that the physical entanglement should be regarded as a shared problem rather than one posed by one twin to the other. And if, after deliberation, separation surgery is deemed the "least detrimental alternative" or the "lesser of two evils", then there should be recognition of what conjoined twins will lose, as well as gain, through separation. The current drive to separate twins at all costs may evince a deeper unease with bodily configurations that appear to threaten the premium that the Western ethical and legal tradition places on personal sovereignty, and the physical circumscription that such sovereignty assumes.
Background. Conjoined twins are a rare complication of monozygotic twinning and are associated with high perinatal mortality. Case. Here we present a case of conjoined twins in a triplet pregnancy diagnosed at 13 of weeks gestation. With the aid of 3D ultrasound and MRI images, the parents were counseled regarding the management options, including continuation of pregnancy, termination of pregnancy, or selective fetocide. They chose selective fetocide of the conjoined twins and went on to deliver the remaining triplet at term. Conclusion. This case represents to our knowledge the only MRI images of conjoined twins in a triplet pregnancy and demonstrates how 3D imaging can be used to better counsel patients about management options.
This study reports on the experience of one hospital regarding the surgical aspects, anatomic investigation and outcomes of the management of 21 conjoined twin pairs over the past 20 years.
All cases of conjoined twins who were treated during this period were reviewed. A careful imaging evaluation was performed to detail the abdominal anatomy (particularly the liver), inferior vena cava, spleen and pancreas, either to identify the number of organs or to evaluate the degree of organ sharing.
There were eight sets of ischiopagus twins, seven sets of thoracopagus twins, three sets of omphalopagus twins, two sets of thoraco-omphalo-ischiopagus twins and one set of craniopagus twins. Nine pairs of conjoined twins could not be separated due to the complexity of the organs (mainly the liver and heart) that were shared by both twins; these pairs included one set of ischiopagus twins, six sets of thoracopagus twins and one set of thoraco-omphalo-ischiopagus twins. Twelve sets were separated, including seven sets of ischiopagus twins, three sets of omphalopagus twins, one set of thoracopagus twins and one set of craniopagus conjoined twins. The abdominal wall was closed in the majority of patients with the use of mesh instead of the earlier method of using tissue expanders. The surgical survival rate was 66.7%, and one pair of twins who did not undergo separation is currently alive.
A detailed anatomic study of the twins and surgical planning must precede separation. A well-prepared pediatric surgery team is sufficient to surgically manage conjoined twins.
Conjoined Twins; Surgical Separation; Ischiopagus Tripus Conjoined Twins; Omphalopagus Conjoined Twins; Thoracopagus Conjoined Twins
Objective. Conjoined twin is a rarely seen congenital anomaly together with severe mortality and morbidity. The more common types of conjoined twins include the thoracopagus type, where the fusion is anterior, at the chest, and involves the heart. We are reporting one case of conjoined thoracopagus twins diagnosed by ultrasonography at 11 weeks. Case Report. In a multigravid pregnant woman who has been admitted to our clinic with a diagnosis of conjoined twins, thoracopagus, by ultrasonography at an 11-week gestation, termination of the pregnancy was performed. Conclusion. Making an early diagnosis with ultrasonographic examination gives the parents a chance to elect pregnancy termination.
Thoracopagus twins were delivered at 37 weeks' gestation by caesarean section. Respiratory distress was present and mechanical ventilation was needed; 36 hours after delivery severe lactic acidosis developed and the twins died. The pericardial sac was common and the hearts were conjoined as a single structure with ventricular fusion.
It is usually held that there is a time continuum in the formation of monoxygotic (MZ) twins which is indexed by their placentation, running from dichorionic to monochorionic diamniotic to monochorionic monoamniotic and conjoined pairs. There is good evidence that this continuum is characterised by a continuum of predisposition to anencephaly, slightly raised in dichorionic pairs but very high in some sorts of conjoined pairs. Although MZ twins, especially monoamniotic and conjoined pairs, are peculiarly liable to anencephaly, they are not particularly susceptible to spina bifida. Among twin pairs concordant for anencephaly or spina bifida, there are strikingly few concordant in the sense of one twin having anencephaly and the other spina bifida, in contrast with the numbers of pairs concordant for the same malformation. The prevalence of anencephaly in double monsters varies with the type of monster, being high in diprosopus. These findings may be explained by the timing of embryonic events.
Anaesthesia for conjoined twins, either for separation surgery, or for MRI or other evaluation procedures is an enormous challenge to the paediatric anaesthesiologist. This is an extra challenging surgery because we the anaesthesiologists need to care for two patients at the same time instead of just one. Anaesthesia for conjoined twins ‘separation surgery mainly centered on the following concerns: 1.Conjoined Twins’ physiology like crossed circulation, distribution of blood volume and organ sharing with their anaesthetic implications. 2.Long marathon surgery with massive fluid shifts and loss of blood & blood components and their rapid replenishment. 3.Meticulous planning for organized management of long hours of anaesthetic administration in two paediatric subjects simultaneously with multi surgical specialties' involvement and their unique requirements. We report the anaesthetic and intensive care management of one pair of Pygopagus separation surgery and also the review of literature and world statistics.
Conjoined twins; Separation surgery; Anaesthesia; Monitoring
Conjoined twins show varying degree of conjoining in either facing or side-by-side fashion. Cephalothoracopagus janiceps is a prototype of facing anomaly in which the two bodies demonstrated a cross symmetry to the midline, that is axial symmetry. Interfacial and intersternal lines crossed at a right angle and no abnormality of situs was associated. Dicephalus dipus dibrachius is a case of side-by-side union, in which the bodies facing nearly the same direction were symmetrical to the middle sagittal plane. Abnormal situs of one was always associated. Other types of conjoined twins as thoracopagus lie between the two extremes of facing and side-by-side union. The three dimensional architectures of the organs in each type would be explained using cross sectional figures of skull, thorax and pelvis. Although the facing twins share the internal organs without fusion, the organs in the side-by-side component are fused with modification of the situs. We postulate sixteen pairs of situs and four manners of division for the explanation of the midline organs and the presence of a dominant co-twin. The splenic locations in a given cardiopulmonary situs are evaluated for the appraisal and applicability of these hypotheses.
Laterality defects are quite common in thoracoileopagus and parapagus dicephalus but rare in other types of conjoined twins.
To present the presumed laterality defects in cephalothoracoileopagus and prosopothoracoileopagus conjoined twins, based on the unilateral or bilateral absence or duplication of the spleen.
Materials and methods
Three human anatomical specimens of craniothoracoileopagus (CTIP) twins and one of prosopothoracoileopagus (PTIP) twins were investigated. The specimens were part of the Museum Vrolik collection of the Department of Anatomy and Embryology of the Academic Medical Centre, University of Amsterdam, The Netherlands. The specimens were taken out of their jars and scanned with multidetector CT and volumetric T2-weighted MRI at 1.5 T.
The internal anatomy of the specimens was largely in accordance with previous reports. However, there was no recognisable spleen in the right twin in one CTIP specimen, in the left twin in one other CTIP specimen, and in both twins in the third CTIP specimen and in the PTIP specimen.
Asplenia and polysplenia are considered reliable indicators of right and left isomerism, respectively. However, three of our four specimens had laterality patterns that did not correspond with those previously reported. Since no other parameters of laterality defects could be verified in these specimens, we concluded that asplenia was unlikely to be caused by laterality defects.
Conjoined twins; Laterality defects; Imaging; Historical specimen
A conjoined twin is one of the rare congenital defects. Ischiopagus variety is even rarer. We present a case of ischiopagus-tripus conjoined twins. They were fused at the lower halves of the bodies. One of the twins was apparently normal looking, active and pink. The other twin was small, ill looking, sluggish and cyanosed. There were two well formed separate lower limbs on one side and a fused limb at the other side. The twins had an imperforate anus and two small orifices draining urine with incompletely developed external genitalia. Pre-operative workup was in progress when the twins passed away.
Conjoined Twins; Ischiopagus; Tripus; Tetrapus
12 cases of conjoined twins from West Africa were reported between 1936 and 1978. Eight sets were liveborn and were surgically separated either in local hospitals or abroad. Four were stillborn. Two new cases of stillborn conjoined twins were recently delivered at this hospital. The most common type and the ones most likely to be born alive were the omphalopagi. Surgical separation was successful in 5 cases but the twins separated at Zaria died about a month later. Emergency operations were performed on the pygopagus and ischiopagus, and one member of the former but both of the latter died. The thoracopagus and dicephalus twins were stillborn. However, necropsy findings in one of the thoracopagi indicate that surgical separation would have been feasible had the twins been born alive. The internal mechanical factors causing cardiac defects in such twins may be relevant to the study of the pathogenesis of congenital cardiac malformations.
Conjoined twins are rare and present a unique challenge to pediatric surgeons and radiologists. An imaging strategy to accurately define anatomic fusion, vascular anomalies, and other associated abnormalities is important for surgical planning and prognostic information. A conjoined female twin with a combined weight of 2.8 kg was born by emergency caeserean. Hence, a computed tomography scan of the thorax and entire abdomen at 1.25 mm slice thickness was performed to delineate the internal structures of the twins. CT-angiography defined specific vascular supply which determined the distribution of shared structures between the twins. An echocardiogram showed four heart chambers with atrioventricular septal defect. To further evaluate the heart chambers, the twin was planned for gated cardiac magnetic resonance imaging. Unfortunately, they succumbed 6 hours apart due to complication of septicemia. Magnetic resonance imaging and CT scan provide excellent anatomic detail, demonstrating organ position, shared viscera, and limited vascular anatomy, whilst angiography defined specific vascular supply, useful in determining the distribution of shared structures between the twins in planning for surgery.
Cases of conjoined twins occur so rarely that it is important to learn as much as possible from each case.
We present a case of 9-hour-old, female, Nigerian dicephalus parapagus conjoined twins discordant for anencephaly diagnosed only after the birth of the twins. The anencephalic twin was stillborn while the normal one died within 9 hours of birth from cardiopulmonary failure.
Many congenital defects of interest can now be detected before birth. A severe lesion such as that found in our index case, which is incompatible with postnatal life, requires counselling. If detected early enough during a properly monitored antenatal care, it may indicate termination of pregnancy.
Conjoined twins are rare variants of monozygotic twins, which result from an incomplete division of the embryonic disk. Cephalothoracopagus is a rare twin pregnancy described as imperfect fusion of the head and chest, but separated columns, limbs, and pelvis. They occur with incidence rates that range from 1 per 50,000 to 1 per 100,000 births; however, the incidence of the cephalothoracopagus variety is 1 per 58 conjoined twins. In the case of identical and symmetric faces caused by the orientations of the 2 notochordal axes that are perfectly ventroventral, they are called janiceps disymmetros. We present a prenatal diagnosis of a typical case of cephalothoracopagus janiceps disymmetros and the diagnostic confirmation by image and pathology exams.
Thoracoomphalopagus is the commonest type of conjoined twin where the bodies are fused from upper chest to lower chest. The autopsy done can help counsil the parents for further pregnancies and determine the prognosis depending upon the type of cardiac anomaly by Seo classification when detected antenatally. We describe the detail pathological autopsy of such a case with single heart and single liver.
A detail autopsy was done on the twin fetus.
The twins shared a single heart and sometimes the liver and part of digestive system. The combined weight was 4.1 KG. Both were full-term male babies joined from below the nipple till umbilicus.
Autopsy in conjoined twins helps in deciding the type of fusion of the body and also of the heart and great vessels. It can help in counseling parents about future pregnancies that there is no chance of recurrence of this abnormality and no need to be scared.
Transvaginal three-dimensional (3-D) and color Doppler ultrasound were used to establish a first-trimester definitive diagnosis and classification of thoracoomphalopagus conjoined twins following two-dimensional (2-D) transabdominal and transvaginal scans that indicated twin gestation of uncertain classification. Color Doppler in combination with 3-D ultrasound can be a useful complement to 2-D ultrasound to confirm early diagnosis and determine the extent of organ sharing and definitive classification of conjoined twins.
This case report presents the prenatal diagnosis of conjoined twins at 7 weeks and 6 days’ gestation according to the last menstrual period and 6 weeks and 4 days’ gestation according to crown-rump length in a 32-year-old Turkish woman, using two-dimensional Doppler ultrasound. The twins were fused to each other at the thoracic region (thoracopagus). In the light of previous reports of conjoined twins this appears to be one of the earliest prenatally diagnosed cases in the medical literature.
Cranially conjoined twins (craniopagus) are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulation.
Craniopagus; digital subtraction angiogram; 3D rotational angiogram
Providing anaesthesia for the separation surgery of conjoined twins presents unique challenges to the managing anaesthesiologists. The low incidence of such surgeries and anatomical variations in each type of conjoined twins makes each separation surgery a unique experience. This report features the anaesthetic plan and challenges faced in performing the separation surgery of a set of thoraco-omphalopagus twins in a rural secondary hospital in a remote location in India.
Anaesthesia; anaesthetic management; conjoined twins; thoraco-omphalopagus twins; twin separation surgery
Conjoined twins have been viewed with fascination since antiquity. There are numerous reports in the literature documenting anesthetic management strategies for the separation of conjoined twins. There are also reports in the literature detailing anesthetic approaches for surgical procedures not involving separation. This is the first report of the anesthetic management of a set of omphalagous presenting for palliative repair of omphalocele in Nigeria.
Anesthesia; Nigeria; omphalocele; omphalopagus; surgery
An ectopic or accessory limb attached to the back is an extremely rare and strange condition, and there are only a few documented cases in the worldwide literature. The first case was described by Jones and Larkin (1889). There are several theories regarding the origin of this condition. Asymmetric conjoined twinning which is located dorsally in the vertebral column (rachipagus) is the most probable diagnosis of our patient. Conjoined twinning is very rare and the incidence is 1 per 50 000 live births. Rachipagus is even rarer, with no more than 30 case reports so far (Chadha et al. (1993, 2006)). In this report, we present a patient who underwent successful surgical excision of a third arm attached to the back in the midline over the low-dorsal region. Differential diagnoses including teratoma and fetus in fetu are discussed.
Multifetal gestations are high-risk pregnancies involving higher perinatal morbidity and mortality, and are subject to unique complications including twin oligohydramnios-polyhydramnios sequence, twin-to-twin transfusion syndrome, acardiac twins, conjoined twins, co-twin demise, and heterotopic pregnancies. The purpose of this study is to describe the prenatal ultrasonographic and pathologic findings of these complications.
Twins; Twins, abnormalities; Ultrasound
Heteropagus twinning is a rare occurrence. Parasitic and asymmetric conjoined twins are rarer anomalies of monochorionic monoamniotic twins; which consist of an incomplete twin attached to the fully developed body of the co-twin. We present here two such cases of Heteropagus twinning.
Heteropagus; Twins; Omphalocele