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
Asymmetric and parasitic conjoined twins are rarer anomalies of monochorionic monoamniotic twins, consisting of an incomplete twin attached to the fully developed body of the co-twin.
A 30-year-old multigravid woman referred to maternal fetal unit due to polyhydramnios at 28th week of gestation. Sonographic examination revealed a single fetus and polyhydramnios with amniotic fluid index 30 cm. The fetus had normal apparent single head, spine, thorax, abdomen, two upper and two lower limbs, and two relatively well developed rudimentary parasitic lower limbs at sacral region. Lower limbs of the autosite were moving freelly but no movement was detected at the parasite. The parasite contained irregular lower limbs and left foot with three toes. Short and deformed long bones were also present in the parasitic limbs. A Cesarean section was performed at 38th week of gestation and a live female infant weighing 3600 g was delivered. The parasitic lower limbs were totally excised. Post-operative period was uneventful and the newborn was discharged as healthy. Post-natal follow-up was normal at nine-month-old.
Pygopagus tetrapus parasitic twin is a rare form of conjoined twins and in utero diagnosis with ultrasound assists in prenatal management and counselling with parents.
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 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.
One of the most interesting congenital malformations is that of conjoined twins. We report echocardiographic features of twin heart in dicephalus, tribrachius, dispinous, thoracoomphalopagus twin. It showed two hearts fused at atrial level. Right-sided heart had single atrial chamber with a single ventricle. A single great vessel, aorta, originated from it. Left-sided heart was well developed with two atria and two ventricles. There was a small mid muscular ventricular septal defect and a small patent ductus arteriosus. Great arteries had normal origins.
Cardiac malformations in twins; conjoined twins; fused heart
There is no record of both separated ischiopagus tetrapus conjoined twins leading normal lives 22 years after separation. We separated a pair of such twins in 1986 and have followed them up till date. Details regarding the technique of separation and the procedures required to ensure normal defecation and micturition and normal musculoskeletal function have been described by us in earlier communications. In this paper we describe their present status and ability to face the world as independent adult females. The outcome reflects the responsibilities and dedication of pediatric surgeons for infant patients with congenital problems after they have become adults, taking a pivotal role to involve surgeons of other disciplines as and when necessary.
Conjoined twins; ischiopagus twins; twins seperation
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.
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
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.
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.
The authors report a case of a cephalopagus conjoined twin that was diagnosed at 29 weeks of gestation despite the mother having had two ultrasounds done previously. The fetus had one head and face, fused thoraces, common umbilicus but had two pelvises and two sets of genitalia. The fetus had four normally formed legs and arms.
Antenatal ultrasound images are supplemented by post natal photographs. A review of literature, clues to ultrasound diagnosis and possible causes of missing this significant abnormality until the 3rd trimester are discussed.
conjoined twins; ultrasound; missed diagnosis; false negative; cephalopagus
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
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.
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.
To determine the accuracy of prenatal and postnatal echocardiography in delineating the degree of cardiac fusion, intracardiac anatomy (ICA), and ventricular function of 23 sets of conjoined twins with thoracic level fusion presenting to a single centre over a 20 year period.
13 thoracopagus, 5 thoraco‐omphalopagus, and 5 parapagus pairs presenting to the authors' institution between 1985 and 2004 inclusive were assessed. Echocardiographic data were analysed together with operative intervention and outcome. Twins were classified according to the degree of cardiac fusion: separate hearts and pericardium (group A, n = 5), separate hearts and common pericardium (group B, n = 7), fused atria and separate ventricles (group C, n = 2), and fused atria and ventricles (group D, n = 9).
The degree of cardiac fusion was correctly diagnosed in all but one set. ICA was correctly diagnosed in all cases, although the antenatal diagnosis was revised postnatally in three cases. Abnormal ICA was found in one twin only in two group A pairs, one group B pair, and both group C pairs. All group D twins had abnormal anatomy. Ventricular function was good in all twins scanned prenatally, and postnatally function correlated well with clinical condition. Thirteen sets of twins in groups A–C were surgically separated; 16 of 26 survived. None from groups C or D survived.
Prenatal and postnatal echocardiography accurately delineates cardiac fusion, ICA, and ventricular function in the majority of twins with thoracic level fusion. It is integral in assessing feasibility of separation. The outcome in twins with fused hearts remains dismal.
congenital heart disease; echocardiography; cardiac surgery; prenatal diagnosis
Documentation of superfoetation is extremely rare in humans., The younger foetus has invariably been small for gestational age (estimated from the date of the last menstrual bleed) in all the cases reported in the literature. We report a case where the younger twin was of appropriate size for gestation.
The first of twins was of 32 weeks gestation and the baby was of appropriate size and development for the gestational age. The second twin was of 36 weeks gestation. Gestational age was estimated with the New Ballard score, x-ray of the lower limbs, dental age on x-ray, and ophthalmic examination.
Bleeding on implantation of the first foetus probably helped demarcate the two pregnancies. Dental age and the New Ballard score can be used to diagnose superfoetation in discordant twins, when detailed first trimester ultra-sound data is not available.
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
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.
Caudal duplication syndrome is a rare entity in which structures derived from the embryonic cloaca and notochord are duplicated to various extents. Its prevalence at birth is less than 1 per 100,000. The term caudal duplication encompasses a spectrum of anomalies and is often used to describe incomplete separation of monovular twins or referred to as part of the spectrum of anomalies associated with conjoined twinning. It usually includes multiple rare malformations and duplications of distal organs derived from the hindgut, neural tube, and caudal mesoderm. It was postulated that the disorder is related to misexpression of one or more of the distal HOX genes, potentially HOX10 or HOX11, leading to abnormal proliferation of caudal mesenchyme. The malformations are usually diagnosed by anomaly scan in the second trimester. Here we report the case of a baby presenting on the first day of life with complete duplication of caudal structures below the dorsolumbar level.
Caudal duplication syndrome; caudal mesoderm; hindgut; monovulat twinning; neural tube
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
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.
Diphallus is a rare anomaly and accompanying anomalies vary from bifid scrotum, bladder exstrophy, imperforate anus and colo-rectal anomaly such as duplication, and other associated anomalies.
A 2-day old infant is reported with imperforate anus and complete duplication of recto-sigmoid colon, rectal pouch, doubling of the genitalia with completely formed penis (diphallus), double bladder, urethra and hypospadias. No family history of abnormalities was noted. The patient underwent several operations: laparatory and colostomy at 3rd day of life, and after clinical and paraclinical investigations, cystoplasty, ureteral reimplantation and resection of left phallus were carried out when 4 months old. At the age of 1 year, after colostogram and total colon evaluation, laparatomy, resection of duplicated recto-sigmoid colon, and pull-through was carried out; 3 months later colostomy closure was performed and the patient discharged without complications.
The patients with diphallus have to be examined carefully because of the high incidence of other systemic anomalies. Treatment of diphallus usually includes excision of the duplicated penile structure, its urethra, and repair of associated anomalies.
Imperforate Anus; Hindgut duplication; Double bladder; Diphallus; Colo-rectal anomaly
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