A case of thoraco-omphalo-ischiopagus bipus conjoined twins

A Case of Thoraco-Omphalo-Ischiopagus By Mustafa

Melikoglu,

Adnan

Aslan, Atalay

Bipus Conjoined

Mete, Can bkaynak,

Mustafa

Twins

inan, and Seyda Karaveli

Antalya, Turkey l A case of thoraco-omphalo-ischiopagus bipus conjoined twins is reported. The twins shared a common lower chest and abdominal wall, a single pelvis and two lower extremities. Our initial approach was to determine the detailed anatomy of the viscera and then to outline a surgical plan. However, the twins’ general condition gradually deteriorated, and the approach was not completely realized despite maximal supportive therapy for cardiorespiratory failure. After the death of the twins, it was detected that they had a single pericardial cavity, and shared an abdominal aorta and vena cava. Furthermore the right twin had Bochdalek hernia and left ventricular hypoplasia. Consequently, such cardiovascular pathologies, coupled with major additional anomalies, may threaten the twins’ life. Therefore further management plans are required considering urgent surgical correction of the life-threatening anomalies before the definitive procedure. Copyright o 1997 by W.B. Saunders Company

INDEX WORDS: gus, ischiopagus.

Conjoined

twins,

thoracopagus,

omphalopa-

T

HE INCIDENCE of conjoined twins may vary from 1 in 50,000 to 1 in 200,000 births.lm4Thoracopagus is the most commonanomaly (75%), followed by pygopagus (18%), ischiopagus (6%), craniopagus, and other duplications (1 %).5 Ischiopagustwins are joined at the pelvis, and fusion beginsat the level of commonumbilicus and lower trunk with bipus, tripus, or tetrapus.1x4,6-8 In this report, a caseof thoraco-omphalo-ischiopagusbipus conjoined twins has been presentedto describe this unique anomaly and to discussits management. CASE REPORT Conjoined twins were delivered by cesarean section as the first children of a healthy, 23-year-old mother in another hospital. Three hours after delivery, the twins were referred to our hospital. The mother was primipara and gestational age of the twins was 40 weeks. Routine prenatal ultrasonography had suggested a normal twin pregnancy without diagnosis of conjoined twins.

Clinical Picture and GrossAppearance On hospital admission, general conditions of the conjoined twins were poor. Total weight of the twins was 5,200 g. They were fused side to side in the thoracoabdominal region at a right angle sharing the same

From the Departments of Pediatric Surgery, Cardiac Surgery Radiology, and Pathology, Akdeniz University School of Medicine, Antalya, Turkey. Address reprint requests to Ahstafa Melikoglu, MD, Akdeniz &iversitesi Tzp Fakiiltesi, gocuk Cerrnhisi Anabilim Dnlz, 07058 Antalya, Turkey. Copyright o 1997 by WB. Saunders Company 0022.3468/97/3204-0035$03.00/O 656

abdomen and pelvis (Fig 1). They had two heads, two upper chests, and four upper extremities. Fontanel openings and cranial diameters were normal in size. The upper trunk of the right twin was more cyanotic than the left one. Cardiac auscultation of the twins showed two normal heart sounds without murmur. They had one normal umbilical cord. Neither abdominal distention nor intraabdominal mass was detected. They shared a single anus, and meconium was found during rectal examination. External genitalia were in a normal male configuration with right inguinal hernia. The right and left testicles were palpated in the inguinal canal and scrotum, respectively. There were two lower extremities with the left one having abduction and internal rotation deformities. In neurological examination, the left twin had normal sucking and Moro reflexes. Neither of these reflexes was observed in the right twin. Their lower extremities had separate innervations. After brief examination and evaluation in the emergency service, they were admitted to the neonatal intensive care unit, and intravenous fluid and antibiotics were initiated. The twins were evaluated by plain films, ultrasonography, echocardiography, and computed tomography. Plain films showed two vertebral columns joining at the common pelvis and two heart shadows (Fig 2). Ultrasonography and computed tomography supported the presence of single liver, two gall bladders, two dilated upper urinary tracts, and single abdominal aorta and vena cava. Computed tomography additionally showed that the right twin had left pulmonary atelectasis and suspicion of Bochdalek hernia. The left twin had only right pulmonary atelectasis. At the echocardiography, aortic and mitral valve echoes were poor visualized, and the left ventricular cavity was diminutive in the right-sided twin. Angiography was planned to study the cardiovascular anatomy in more detail but the twins’ poor general condition has prohibited it. Simultaneously they were consulted by Departments of Cardiovascular Surgery, Cardiology, and Plastic and Reconstructive Surgery to discuss medical and ethical problems that we would encounter. Management alternatives were also discussed with twins’ family. No immediate intervention was performed because of family’s objection and high anesthesia risk. On the second day after admission, the twins exhibited signs of respiratory distress and cyanotic appearance. These symptoms were more pronounced in the right twin. Because blood gas analyses showed respiratory failure in both twins, they were entubated. While the twins were under ventilatory support on the fifth day, cardiac arrest developed and they could not be saved despite cardiopulmonary resuscitation.

PostmortemStudy During grossexamination it was found that twins had two separatehearts in a single pericardial cavity filled with light yellow serousfluid. Heart weight of the right twin was 20 g (left ventricular hypoplasia) and the left twin, 34 g. The right one also had left pulmonary hypoplasia and Bochdalek hernia including the stomach, spleen,andadrenalgland. Two intrathoracic inferior vena cavas andaortasjoined just below the liver andjust above the superior mesenteric artery, respectively. Abdominal organs consisting of stomach, small intestines, adrenal glands, and pancreas were double, but there was a common liver with two extrahepatic biliary tracts and a single urinary tract in both sides of the common abdomen. Small intestines were joined at the terminal ileum Journal

of Pediatric

Surgery,

Vol 32, No 4 (April),

1997:

pp 656-658

CONJOINED

657

TWINS

sia with increased volume of cortical portions and decreased volume of medulla and Hassal’s corpuscles. Pulmonary hemorrhage was found in the right lung of the right twin. There was debris, hemorrhage, and macrophages in the alveoli. In addition, white pulp aplasia of the spleen was detected, but the red pulp was normal in appearance. Adrenal glands had showed Rich’s tubular degeneration in the outer zone and hemorrhage in the deep cortex. DISCUSSION

Fig 1.

External

appearance

of the conjoined

twins.

giving a T-shaped appearance. Urinary collecting system was hydrouretero-nephrotic resulting from bilateral ureterovesical obstruction. It was noted during microscopic examination that the thyroid glands, liver, and pancreas were normal in structure. However, both of the twins had thymic hypopla-

Fig 2. Two plain radiograph.

vertebral

columns

and

a single

pelvis

are

seen

in the

In thoraco-omphalopagus,the twins lay face to face and arejoined in the thorax andepigastrium.’ Commonly, they sharea chest wall, sternum, diaphragm, upper wall, and midabdominal wall. As a more severe anomaly, thoraco-omphalo-ischiopagusconjoined twinning is a very rare condition, and the conjoined twins share a common pelvis in addition to the chest and abdominal walls.9Additionally ischiopagustwins may be classified according to the number of the lower extremities present, as ischiopagusbipus, tripus, or tetrapus.1”.7JoIn the case presented,the twins had commonlower chest, abdomen, pelvis, and two independent normal lower limbs, and they were not laying face to face unlike other reported casesof thoraco-omphalopagusconjoined twins. In the literature, only one caseof thoraco-omphalo-ischiopagus bipus has been reported,g but our case was different becauseof the accompanyingBochdalek hernia, configuration of the major intraabdominal vascular structures, and urological aspects. In treating the conjoined twins, the main goal is to separatethem to be compatible with life.2 The planning for eventual surgical separation should be unhurried to permit growth through diagnostic evaluation of visceral sharing and creation of a multidisciplinary separation team.*OA variety of diagnostic studies is necessary to create diagramsof organsharinganddemonstratecoexisting congenital anomalies.After completion of diagnostic procedures, separation is best performed on an elective basis when the children are 9 to 12 months of age, but timing of the separationmay vary becauseof associated abnormalities.4,9,11 On the other hand, urgent separation may be required, even in the newborn, becauseof the emergency conditions including a stillborn twin, intestinal obstruction, omphalocelerupture, obstructive uropathy, heart or respiratory failure.lOJ1 When the abovementioned views are considered,to draw a management plan in our caseis very difficult becauseof the borderline clinical picture during the first postnatal days. In the presented case, the twins were urgently evaluated by noninvasive diagnostic methods. However, theseprocedures were not conclusive in reporting exact anatomic and pathological findings. More detailed invasive procedures were planned but could not be performed because

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of severe cardiorespiratory problems. Ethical problems further complicated the therapeutic plan to be selected. In such cases, the main question is whether urgent surgical intervention is necessary. Early separation has been reported to have higher mortality. Therefore we think limited surgical intervention directed to life-threatening pathologies is better than urgent separation. From this perspective, diaphragmatic hernia repair and ECMO could be performed while ventricular hypoplasia remains as a serious problem. If the twins had lived, separation could be carried out by a multidisciplinary surgical team at the end of the first year. Nevertheless these stated

ET AL

points are open to speculation, and their usefulness is controversial. In conclusion, thoraco-omphalo-ischiopagus bipus is a rare variation of conjoined twins causing therapeutic dilemma, and its management may be complicated by severe accompanying congenital anomalies. This case stresses that conservative management does not necessarily save the twins from having major additional anomalies. Therefore a staged surgical approach may be an alternative management strategy. In the first stage, lifethreatening pathologies only are corrected, and separation of the twins on an elective basis may be performed in later infancy.

REFERENCES 1. Shapiro E, Fair WR, Temberg J, et al: Ischiopagus tetrapus twins: Urological aspects of separation and 10 year follow up, J Urol 145:120-125, 1991 2. Hoyle M, Hill C: Surgical separation of conjoined twins. Surg Gynecol Obstet 170:549-561, 1990 3. Spitz L, Capps SNJ. Kiely EM: Xioomphaloischiopagus Tripus conjoined twins: Successful separation following abdominal wall expansion. J Pediatr Surg 26:26-29, 1991 4. Chen WJ, Lai HS, Chu SH, et al: Separation of the ischiopagus tripus conjoined twins. J Pediatr Surg 29:1417-1421, 1994 5. Schanaufer L: Conjoined twins, in Raffensperger (ed): Swenson’s Pediatric Surgery. East Norwalk, CT, Appleton & Lange, 1990, pp 969-961 6. O’Neill J; Holcomb G, Schanaufer L, et al: Surgical experience with thirteen conjoined twins. Ann Surg 208299.312, 1988

7. Yokomori K, Ohkura. Kitano Y, et al: Comprehensive planning of operative strategy for separation of ischiopagus tripus conjoined twins with particular reference to quality of life. J Pediatr Surg 28833-837, 1993 8. Cywes S: Challenges and dilemmas for pediatric surgeon. J Pediatr Surg 29:957-965, 1994 9. Spitz L, Stringer MD, Kiely EM, et al: Separation of brachiothoraco-omphalo-ischiopagus bipus conjoined twins. J Pediatr Surg 29:477-481, 1994 10. Diaz JH, Furman EB: Perioperative management of conjoined twins. Anesthesiol67:965-973, 1987 11. O’Neill J, Holcomb G, Schanaufer L: Conjoined twins, in Ashcraft KW, Holder TM (eds): Pediatric Surgery. Philadelphia, PA, Saunders, 1993, pp 948-955