Successful Separation of Female Omphalopagus Conjoined Twins at the Mother and Child University Hospital Center in N’Djamena, Chad: A Case Report

Introduction

Conjoined twins, also referred to as conjoint twins, are defined by the specific region of the body that is fused (shared). They arise from rare cases of incomplete monozygotic twinning, in which the embryonic disk does not fully divide, or adjacent embryonic disks fuse [1]. The classification is based on the site of fusion: thoracopagus (joined at the chest), craniopagus (fused at the head), and omphalopagus (joined at the abdomen) [2]. Recent studies report a prevalence ranging from 1.02 to 1.34 per 100 000 births in Western populations to 3.27 per 100 000 births in China, with a marked female predominance at a ratio of 3: 1 [3]. Additionally, 40% to 60% of conjoined twins are stillborn, and nearly 35% of live births do not survive beyond 24 hours [4]. Antenatal diagnosis of conjoined twins relies primarily on ultrasonography. Early detection is possible in the first trimester between weeks 10 and 13 of amenorrhea [5]. Medical imaging plays a vital role in the management of conjoined twins by enabling anatomical assessment, delineation of shared organs, and evaluation of the feasibility of surgical intervention. It also provides essential guidance for successful separation [6]. Independent survival is only possible through surgical separation, provided there are no malformations, no bony fusion, and separate hearts and brains present [7]. This report describes the successful separation of female omphalopagus conjoined twins at a specialist center in N’Djamena, Chad.

Case Report

These were 1-day-old conjoined twin girls referred to the Neonatology Department of the Mother and Child University Hospital Center of N’Djamena for treatment. It is the only hospital in the country featuring both a pediatric surgery department and a neonatal intensive care unit. The pediatric department has a capacity of 177 beds.

The mother was 35 years old, multiparous, with a gravidity of 9, parity of 9, and 8 living children. She had not received any prenatal care. Gestational age was not documented. The delivery was a home vaginal birth in a village approximately 300 km from the capital. Delivery was conducted by a community-trained traditional birth attendant. Following the birth, the parents visited a health center, where they were referred to the Mother and Child University Hospital Center in N’Djamena. The conjoined twins were transported via a non-medicalized ambulance, accompanied by a nurse.

Upon clinical examination, the twins presented in good general condition, with a combined weight of 4800 g. They exhibited normal tone, good reactivity, adequate coloration, effective sucking and swallowing, and intact primitive reflexes; their fontanelles appeared normal. Oxygen saturation was within normal limits. Each newborn possessed a well-developed head and neck and fully formed thoracic and pelvic limbs. The twins were conjoined over a length of approximately 4 cm along the midline, extending from the xiphoid process to the umbilical region. At the lower margin of the fused area, an omphalocele measuring approximately 1×1 cm was observed, to which the umbilical cord was attached. The thoracic and pelvic limbs were free of axis or structural abnormalities and showed no apparent malformations (Figure 1).

Abdominal computed tomography identified a connection between the inner abdominal wall and a liver of normal size and texture (Figure 2). All other organs appeared entirely normal and well separated. Cardiology consultation and echocardiography were conducted, revealing no cardiac malformations. The decision to proceed with elective surgical intervention was made following a multidisciplinary meeting that included radiologists, anesthesiologists, intensivists, pediatricians, and pediatric surgeons. The specific steps of the procedure were discussed and planned by the team during a subsequent preoperative meeting. Four multidisciplinary team meetings were organized. On the seventh day of life, the twins were admitted to the operating room, where 2 operating tables were prepared in the same room, each with a dedicated surgical team. The twins were positioned laterally and underwent general anesthesia with orotracheal intubation. An incision was made along the entire length of the anterior surface at the site of fusion. After achieving hemostasis, the common aponeurosis of the rectus abdominis muscles was incised, and the peritoneum was opened.

Surgical exploration enabled the identification of clearly distinct organs, with an attachment present at the margins of both livers and a cartilaginous bridge replacing the 2 xiphoid appendages. The 2 livers were carefully separated, the cartilaginous bridge was divided, and posterior separation was completed. The twins were separated within 45 minutes.

The 2 separated twins were positioned in the dorsal decubitus position on separate operating tables for anterior abdominal wall repair, with polyglactin 0 used for the aponeurosis, and skin plasty performed with polyglactin 4/0 (Figure 3). The total operative time was 1 hour and 10 minutes. Both infants were extubated in the operating room and experienced an uncomplicated immediate postoperative course. Oral feeding with breast milk supplemented by infant formula was initiated on the first postoperative day and was well tolerated. The dressings were changed on postoperative days 3 and 10. Wound healing was complete by postoperative day 12; however, due to their distant place of origin, the twins remained hospitalized, with discharge permitted on day 25 of life and postoperative day 18, at weights of 2750 g and 2820 g, respectively. No complications were noted, and wound healing was satisfactory at the time of discharge. With the twins receiving regular follow-up, we noted an episode of severe malnutrition in both twins in month 9, which required hospitalization in the therapeutic nutrition unit for 1 month.

At 24 months, the infants showed good psychomotor development, and the examination of the abdominal wall was unremarkable (Figure 4).

Discussion

From this clinical case, the main lesson to remember is that, from beginning to end, teams must work in synergy. Conjoined twins are an exceptionally rare congenital anomaly, with an estimated incidence ranging from 1 in 50 000 to 1 in 200 000 live births. They arise from incomplete division of a monozygotic, monoamniotic zygote after day 13 of gestation [8]. The initial step in management is precise antenatal diagnosis, typically achievable via ultrasound in the first trimester [9,10]. This approach enables not only confirmation of the fusion, but also informs genetic counseling, delivery planning, and surgical preparation. In our case, antenatal diagnosis was not established, due to a lack of prenatal consultation, a circumstance frequently observed in resource-limited settings. This shortcoming complicates care, as deliveries often take place at home and under unsafe conditions. In cases in which diagnosis occurs before birth, parental counseling is essential, and cesarean delivery is generally recommended. Cesarean delivery helps to prevent dystocia and obstetric trauma, thereby improving the likelihood of survival and subsequent surgical separation [11,12]. The absence of prenatal care in this case highlights a significant gap in management. Adequate antenatal monitoring is crucial for the early detection of conjoined twins and for planning delivery in a tertiary care center. Vaginal delivery is reserved for cases with a poor prognosis [5]. The optimal timing for surgical separation remains a subject of debate. Elective separation, delayed by several months, often provides better survival prospects by facilitating multidisciplinary preparation and optimizing operative conditions. However, urgent separation may be required when the life of one twin endangers the other. Major cardiac malformations generally contraindicate separation [13]. In our case, the absence of cardiac anomalies made surgery feasible. The female predominance observed in our case aligns with the literature, which reports a female-to-male ratio of 1.6 to 3 [11]. Omphalopagus is the second most common type of conjoined twin case, involving fusion from the lower thorax to the umbilicus [14]. This type is thought to offer the most favorable prognosis, particularly when the heart and central nervous system are separate [7,14]. Successful separation largely depends on meticulous planning, multidisciplinary collaboration, involving surgeons, anesthetists, pediatricians, radiologists, and intensivists, and appropriate preoperative imaging, such as computed tomography, magnetic resonance imaging, and ultrasound, to define shared anatomy and assess surgical feasibility [6,15]. Similar outcomes were reported in Guinea-Conakry, involving the separation of pygopagus twins in a facility with comparable technical resources [16]. Closure of the skin remains a major challenge. Some teams use tissue expanders or synthetic meshes to achieve sufficient coverage [17]. In our case, closure was achieved without these additional techniques. The team of Pati et al performed the same type of abdominal closure [18]. Published series report post-separation survival rates ranging from 70% to over 90%, according to the type of fusion and resources available [19,20]. The more than 5 months of follow-up by our team allowed for optimal monitoring. This extended follow-up time is longer than that of other teams [21]. Our experience, the first of its kind in Chad, demonstrates that successful separation can be accomplished even in resource-limited settings if performed by a well-prepared multidisciplinary team. The surgical success was facilitated by the fact that the twins were omphalopagus, with no complex involvement or shared vascularization of the internal organs.

Conclusions

Conjoined twins are a very rare and complex malformation, posing significant diagnostic and surgical management challenges, particularly in low-resource settings. In our context, the absence of prenatal monitoring further complicated these challenges. Favorable progress at 24 months emphasizes that this type of conjoined twin has the highest likelihood of survival following separation. This outcome was achieved through multidisciplinary care and meticulously planned surgery. Beyond the surgical accomplishment, this case underscores the urgent need to improve access to prenatal care in our region. The central message for clinicians is that successful management of such complex cases relies on resource sharing and interdisciplinary collaboration. Enhanced monitoring would facilitate antenatal diagnosis and optimal preparation, including planned cesarean delivery.