Conjoined Hearts in Thoracopagus Twins

This study aimed to identify the anatomic and pathologic structural cardiac abnormalities in conjoined twins and to focus on those that have prevented the successful separation of conjoined hearts. A retrospective review was undertaken to examine consecutive cases of thoracopagus conjoined twins with conjoined hearts evaluated at The Children’s Hospital of Philadelphia from 1 January 1980 through 6 October 2008. The records included autopsy and surgical findings as well as clinical reports. The study group included nine sets of conjoined twins with a mean gestational age at birth of 33.8 ± 5.5 weeks. Three twin pairs were stillborn. Five twin pairs died afterward. One pair died of cardiopulmonary failure. The median age at death was 22 days (range, 0–345 days). Major congenital heart disease was present in 94.4% (17/18) of the hearts, and 72.2% (13/18) of the hearts had single-ventricle physiology. Total anomalous pulmonary venous return occurred in 39% (7/18) of the cases. The clinical outcome for thoracopagus twins with conjoined hearts remains poor because of inability to separate conjoined and single ventricles. Surgical nonintervention and palliative care should be strongly considered for these patients.     

ABNORMAL VASCULATURE OF THE LIVER IN THORACOPAGUS TWINS: Case Report

Each of the two minimally united livers of thoracopagus conjoined twins occupied an epigastrium on opposite aspects of the conjoined abdomen, straddling the plane of conjunction, instead of being located beneath the domes of the diaphragm. Whereas the hepatic artery and portal vein of the right twin supplied only the larger "anterior" liver, the same vessels in the left twin divided to provide blood for both the "anterior" and the "posterior" liver. Thus the "posterior" liver had only one porta hepatis while the "anterior" liver had two. In addition, the hepatic veins of both ectopic livers were found to drain into the inferior vena cava of only the left twin. All of these anomalies have been reported, albeit rarely, among 477 cases of thoracopagus and omphalopagus twins recently reviewed. A theory explaining the abnormal embryology of the liver is proposed.     

Prenatal and postnatal imaging of thoracopagus conjoined twins with a shared six-chamber heart

Management of thoracopagus conjoined twins is predominantly determined by the associated complex cardiovascular abnormalities seen in the majority of these cases. Magnetic resonance imaging (MRI), including three-dimensional contrast-enhanced magnetic resonance angiography (MRA) provides a useful complement to conventional cardiac echocardiography or catheterization for detailed evaluation of the extra-cardiac anatomy. We report a pair of female thoracopagus conjoined twins with a shared six-chambered heart. The MRA findings are highlighted.The opinions expressed in this paper are solely those of the authors and do not represent the views of the United States Air Force, Department of Defense, or the United States Government.     

Various Modalities for Evaluation of a Fused Heart in Conjoined Twins

Conjoined twins are a rare congenital anomaly with an estimated incidence of 1/50,000 to 1/100,000. Among thoracopagus conjoined twins, 75% have a fused heart. We compare the usefulness of various modalities for evaluating cardiovascular structure in fused-heart conjoined twins. We report a series of 20 sets of thoracopagus conjoined twins as well as the results of a PubMed database literature review literature from 1982 to 2009. Twenty sets of fused-heart thoracopagus conjoined twins were evaluated by echocardiography, cardiac catheterization, magnetic resonance image (MRI), and three-dimensional computed tomography angiography (3D-CTA). Imaging results were compared to findings at surgery or autopsy. All sets of conjoined twins underwent postnatal echocardiography; 11 sets (55%) underwent cardiac catheterization; 4 sets (20%) underwent MRI; and 1 set (5%) underwent 3D-CTA. All intracardiac anatomy (ICA) was identified by echocardiography. Cardiac catheterization, MRI, and 3D-CTA were able to identify extracardiac vascular structures as well as the ICA. 3D-CTA, which can be performed as early as the first week of life, is a noninvasive, less expensive, and the safe examination with minimal risk due to its short procedural time. Three-dimensional CTA is an effective and safe modality for evaluating the cardiovascular anatomy of fused-heart conjoined twins before surgery.     

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.     

Cardiovascular abnormalities in thoracopagus twins: embryological interpretation and review

The cardiovascular abnormalities of two sets of thoracopagus twins with conjoined heart and liver are described and compared with 27 well documented cases. An embryological interpretation of the cardiovascular abnormalities is suggested. The common heart in both sets showed a common atrium and two ventricles. In case 1 the great arteries were L. malposed in twin A. In case 2 the great arteries originated from their respective double outlet single ventricle. The systemic and pulmonary veins drained directly into the common atrium in case 1 and indirectly via systemic veins in case 2. The type of cardiovascular abnormalities are complex and discordent from one set to another and in the same set. However among 27 published cases of thoracopagus twins, cardiac union, including atrial union with separate ventricles, or atrial and ventricular union, was encountered in 16 cases. Approximately 90% of them are not suitable for surgical separation because of the high degree of cardiac union and the complexity of cardiovascular abnormalities. Surgical separation could be attempted in only two cases, but at the cost of the life of one of the twins.     

Congenital Heart Defects in Conjoined Twins: Outcome After Surgical Separation of Thoracopagus

In this study, we correlated cardiac malformations in the various types of conjoined twins with the proposed site of embryologic union and evaluated the possibility of survival after surgical separation. We conclude that surgical separation is only very rarely successful in twins with united hearts, whereas survival in twins with separate hearts is more dependent on the malformations of other viscera. This report deals primarily with conjoined twins in whom anomalies of the heart are the major factor in deciding whether surgical separation is feasible.     

联体畸形的诊断与治疗方法探讨

目的 探讨联体畸形的诊断和治疗方法，增进对该少见疾病的认识，提高疗效，以及生存率。方法 采用B超、CT 消化道钡餐等检查，判定内脏连接情况，手术分离2对联体畸形婴儿。2对病例分别为剑脐联体畸形及胸腹联体畸形，均有肝脏连接，但胆囊及胆管各自独立，于生后第28d、第96d时分别实施分离手术，对于肝脏连接的处理，采用“局部血流阻断法”，行共用肝离断术。结果 2对联体畸形经充分术前准备，均手术分离成功，术后患儿生长及发育正常。经采用局部血流阻断共用肝离断术方法，术中出血少，术后肝功能恢复顺利。结论 联体畸形较为罕见，充分的术前准备及合理的分离术式可提高患儿的双双存活率。局部血流阻断共用肝离断术，仅阻断了离断线局部的肝脏血流，对非操作区的肝脏血液供应毫无影响。有利于对创伤及失血耐受性很差的婴幼儿术后康复。     

先天性联体畸形的外科处理

目的 总结4例联体儿分离术的经验,对联体儿诊治提供参考。方法 回顾性分析自1982～2001年,我院小儿外科共收治的4例先天性联体儿外科分离手术的临床资料,着重在手术时机、产前诊断、合并畸形、分离技术、术后监护、随访等方面。结果 4例联体儿畸形,其中胸部-脐联合畸形3例,坐骨联体1例,男性1例,余均为女性。均不同程度合并先天性心脏缺损,坐骨联体儿合并严重大血管畸形,泄殖腔畸形及Pieer-Robin综合征。2例产前超声检查获得诊断。2例紧急分离术时间为出生后7d内,存活1名。另2例延迟分离手术时间>1个月,均存活。随访存活的5名患儿,1982年分离的剑突-脐联体儿其中1名于术后4年“肺炎”死亡。另1名已20岁,健在。另一对胸部-脐联体儿术后1年发育良好。1例坐骨联体儿1名死亡,1名失随访。结论 手术时机与分离方式必需依据每一对联体儿局部环境及器官结构而定。紧急分离术存活率低,能延迟行分离术则存活率高。     

Anomalies in Cephalothoracopagus Synotus Twins and Their Implications for Morphogenesis in Conjoined Twins

The anatomical features of a pair of female conjoined twins of the cephalothoracopagus type are described: the anterior face was well formed but the posterior face was cyclopean with a single ear canal. Visceral abnormalities included two shared hearts linked by an anastomotic arterial ring. The smaller of the hearts was univentricular with atrial situs ambiguus and anomalous pulmonary venous return, and was associated with two trilobed lungs. This, and the presence of a single spleen, suggested asplenia syndrome in one twin. The brains, orientated with respect to the notochordal axes, were joined only at the frontal poles. The abnormalities described in previous reports of twins of this type are reviewed and compared. In addition to alterations in body pattern due to conjoining, endodermal developmental defects and abnormal laterality appear to have been involved in the morphogenesis of this case. Received May 22, 1998; accepted October 3, 1998     

Depressed natural killer cell activity due to decreased natural killer cell population in a vitamin E-deficient patient with Shwachman syndrome: reversible natural killer cell abnormality by α-tocopherol supplementation

Natural Killer (NK) cell activity was examined in a 16-month-old Japanese boy with Shwachman syndrome associated with severe vitamin E deficiency. As evaluated by ⁵¹Cr-release assay from K562 cells, NK cell activity was constantly decreased. After 8 weeks of oral α-tocopherol (α-Toc) supplementation (100 mg/day), NK cell activity had normalised. When α-Toc supplementation was interrupted for 16 weeks, NK cell activity again decreased. Flow cytometry of peripheral lymphocytes revealed a lowered number of CD16⁺ CD 56⁻ fraction, which has the most potent NK cell activity. Single cell-in-agarose assay, to investigate the binding and cytolytic activity of NK cell at the single cell level, revealed that the number of NK cells which bind to K562 cell was decreased, but that the cytolytic activity of the individual binding cell was relatively unaffected. A second supplementation of α-Toc for 8 weeks successfully restored NK cell activity, the number of cells expressing NK cell markers and the number of K562-binding cells as compared to the age-matched normal range. Conclusion These results indicate that severe vitamin E deficiency caused impaired NK cell activity due to a decrease in the number of CD16⁺ CD56⁻ NK cells and that this abnormality is reversible with α-Toc supple‐mentation. Received: 30 January 1996 and in revised form: 19 November 1996 / Accepted: 22 November 1996     

The impact of surfactant replacement therapy on cerebral and systemic circulation and lung function

 The influence of surfactant administration on cerebral and systemic circulation and on lung function was evaluated in 12 premature mechanically ventilated infants (mean birth weight 1560 ± 770 g, mean gestational age 30.0 ± 3.2 weeks) with respiratory distress syndrome (RDS) receiving surfactant replacement therapy. We measured mean cerebral blood flow velocity (MCBFV), heart rate (HR), mean arterial pressure (MAP), static compliance (Crs), resistance of respiratory system (Rrs), functional residual capacity (FRC) and fraction of inspired oxygen (FiO₂). In addition to a very low compliance and a moderately elevated resistance of the respiratory system a significant drop in MAP, HR, MCBFV and FiO₂ was noticed after surfactant administration. After 30 min HR, MAP and MCBFV values returned to baseline levels. We postulate that the drop in MCBFV, MAP, HR and FiO₂ with a minor, though not significant, improvement of the FRC can most likely be explained by a “relative” hypovolaemia in other organs and parts of the body due to expansion of the lung vascular bed. Compensation for the redistribution of circulatory volume occurred within several minutes. Blood pressure control and treatment of hypovolaemia is mandatory before surfactant is administered. Conclusion In RDS patients there is a significant drop of MAP, HR, MCBFV and FiO₂ after bolus surfactant administration. Received: 30 August 1995 and in revised form: 30 April 1996 / Accepted 23 July 1996     

Assessment of the cardiovascular system in conjoined thoracopagus twins

The thoracoomphalopagus conjoined twins comprise 75% of all conjoined twins. In the assessment of the organ systems of the twins, the cardiovascular system is important since union of this system in the twins has occurred in 75% of the cases. Of the five cases reported here, two had separate hearts and vessels with a common pericardium only. Two twins were joined at the right atrial level. The fifth pair were connected at both atrial and ventricular levels. It has been suggested that the presence of two separate QRS complexes in the ECG indicates complete separation of the two hearts. Case 4 shows that even in the presence of atrial union, the existence of an atrioventricular block in one twin may produce a very slow heart rate, while the other twin may have a normal rate that will not influence the ventricular rate of the other. In our experience, angiocardiography has been the most useful diagnostic procedure.     

Use of albumin in neonatal resuscitation

The use of albumin plasma has become popular during resuscitation of the term baby with very low Apgar scores (≤ 2 at 1 min). There is no evidence of benefit from this practice which may actually be damaging to babies with severe asphyxia causing myocardial damage. Received: 4 May 1996 and in revised form: 7 October 1996 / Accepted: 16 October 1996     

Neuroblastoma and insulin-like growth factor system

Neuroblastoma is, at the same time, the most common and the most puzzling extracranial solid tumour in childhood, being able to regress spontaneously despite widespread dissemination, showing a striking high incidence of the in situ form, and, finally, being resistant even to aggressive chemotherapy. The reasons of this bizarre behaviour are still largely unknown due to our little knowledge of neuroblastoma pathophysiology. There is increasing body of evidence that the insulin-like growth factor system plays a crucial role in the proliferation and differentiation of neuroblastoma cells and it is conceivable that a better knowledge of this role might potentially lead to new and more effective therapeutic strategies. Here we review the most recent insights into the biology of neuroblastoma, focusing on the close links with the insulin-like growth factor system and the potential clinical perspectives. Received: 13 May 1996 and in revised form: 15 July 1996 / Accepted: 15 July 1996     

Conjoined twins — the Cape Town experience

This paper records our experience in the management of 25 sets of conjoined twins seen over a 32 year period (1964–1996). The twins were classified into 14 complete and symmetrical sets and 11 incomplete or heteropagus. The 14 symmetrical sets included 9 thoracopagus, 2 ischiopagus, I craniopagus and 1 omphalopagus twins. In the incomplete heteropagus group there was I ischiopagus, one twin being anencepahlic, 2 dipygus, 5 parasitic, 2 fetus-in-fetu and I cranial and caudal. The management is detailed case by case. Overall 10 of 14 symmetrical sets underwent attempts at separation with 16 surviving the procedure, but there were 3 late deaths. In the incomplete group 10 of 11 were operated on with 9 survivors. The importance of a multi-disciplinary approach, the extensive investigations required pre-operatively to define areas of organ and bony conjuction, congenital anomalies of each twin and surgical teamwork is emphasized. Specific problems encountered were indentified. In thoracopagus twins the hearts were of paramount importance as conjuction was usually fatal, being associated with major congenital defects. The greater the extent of thoracic cage fusion the greater the chance of associated severe anomaly. Skin expansion to assist coverage of the defects after separation was of great assistance, as was the use of collagen coated vicryl. Evaluation of the liver and pancreatico-biliary systems with isotope excretion scanning was crucial to pre-operative planning. Where there was fusion of the duodenum a single pancreatico-biliary system could be expected and prior strategies for separation and Rouxen-Y enteric drainage of both pancreatic and biliary secretion should be planned. Gastro-oesophageal reflux led to considerable morbidity in both twins of a thoraco-omphalopagus set. In ischiopagus and dipygus conjoined twins bilateral posterior iliac osteotomies were an essential component to anatomic reconstruction of the pelvic ring and wound closure. Also in this group, due to the frequency and extent of shared genital, urinary and ano-rectal structures, long-term morbidity was expected and a component of this might be due to spinal cord tethering, or as in one of our cases, a progressive hydrosyringomyelia. Timing of separation was ideally set at between 5 and 9 months with 6 to 8 weeks of prior tissue expansion but earlier operation was frequently required because of cardio-respiratory problems or organ failure in one twin. In most cases the goal of obtaining separate, independant and intact individuals was achieved.     

影像学检查在臀部联体儿术前诊断中的价值

目的 探讨影像学检查在臀部联体儿术前评估中的价值,及其对分离手术方案和分离后患儿预后的意义.方法 对我院最近成功分离的1例臀部联体患儿,结临床查体选择进行B超、X线、CT、MRI检查,分析其影像学特点,以明确联体儿连接部位、范围、内容,以及是否伴有身体内部其他器官的畸形.结果 连接部前后径7.9 cm,上下径6.0 cm,位于腰骶部.双侧患儿腰3以下椎板裂,无骨性结构连接,但存在脊柱及骨盆的软骨连接.患儿下消化道及肛门独立,泌尿道独立.硬膜囊相连,但脊髓及马尾神经无相连及交叉支配.联体双患儿均存在动脉导管未闭,其中一侧患儿存在隐睾,未见其他畸形.术中所见证实影像学的结果.选择交叉V型皮瓣覆盖创面,直接缝合硬膜,联体儿成功分离,无术后感染及脑脊液漏,皮瓣愈合良好,无神经损伤,随访6个月,2例患儿发育及神经功能均正常.结论 根据联体儿分型,结合查体选择和利用各种影像学检查,能较全面地反映连接部位的范围、内容,对手术的难度预测、手术方案制定、术后预后评估有重要意义.     

Sudden infant death and prevalence of whooping cough in the Swedish and Norwegian communities

Whooping cough (WC) has been suggested to be a trigger factor for sudden infant death (SID), the proposed mechanism being unrecognised hypoxaemic episodes. In contrast to Norway, Sweden ceased its immunisation programme against Bordetella pertussis (BP) in 1979. We investigated the relation between SID mortality and the prevalence of BP during 1983 to 1988, by month, in the two ethnically and socially similar, bordering countries adopting different strategies towards WC. In addition, the greater Stockholm area was analysed. For both countries the prevalence of BP was collected from monthly reports by regional health officers. SID mortality rates were provided by the Norwegian Central Bureau of Statistics and the SID registry at the Swedish National Board of Health and Welfare. The relation between SID mortality rate and prevalence of WC, by month, was analysed by linear regression. In addition, the consistency of seasonal fluctuations was investigated by analysing the covariance between average, pooled, monthly values of the two variables. SID mortality rate followed significantly the monthly prevalence of BP in Sweden (P < 0.01) and Stockholm (P < 0.0001) during the study period. In Norway there was a significant correlation only during the epidemic outbreak of WC (P < 0.05), but not for the whole study period. When controlling for seasonality a significant correlation remained in the urban area of Stockholm (P < 0.05) Conclusion It is suggested that covariations between WC and SID mortality rate may be related to transmission rate and immunisation status of the investigated population. Received: 6 May 1996 / Accepted: 21 August 1996     

Parasitic twins - new observations

In the course of the last 7 years we observed two cases of unequal twins, “thoracopagus parasiticus.” When a conjointed twin is unequal, the smaller member of the conjoined pair is spoken of as a parasite and the more nearly normal one as the autosite [3]. Reports about their anatomy and physiology are lacking in the literature, and therefore an attempt has been made to provide some information on the anatomy and physiology of the parasite.     

Poorly Organized Parasitic Conjoined Twins: Report of Four Cases

We report four examples of parasitic conjoined twins (PCT) that created difficulties in diagnosis and treatment because of their unusual presentation and poor internal organization. Case 1 appeared as a tumor on the back containing an adrenal gland and part of the small bowel and stomach; two spines with spinal cords were present. Case 2 was similar, but mature and immature renal tissue were included and a meningocele with Arnold-Chiari type II malformation was recognized in the autosite spine. Retrospective interpretation of both cases suggested that the left lower limb and pelvis were part of the parasites. In case 3 the parasite was attached at the perineum and lower abdomen, contained a rudimentary spine in continuity with the coccyx of the autosite, and was partially covered by scalp. Case 4 presented as a limblike tumor attached at the suprapubic region. All cases were complicated by disruptions in the autosites. Surgical treatment was successful in cases 1, 2, and 3. These four anatomically poorly organized PCT are best categorized as intermediate between teratomas and the more common types of PCT.