Twenty-three-year follow-up of separated ischiopagus tetrapus conjoined twins

The first successful lower extremity transplantation: 6-year follow-up and implications for cortical plasticity

Vascularized composite allotransplantation as a viable reconstructive option is gaining recognition and new cases are being reported with increasing frequency including hand, face and laryngeal transplantation. However, only one successful complete lower limb transplantation has been reported to date, in which a functioning limb from one ischiopagus twin with a lethal cardiac anomaly was transplanted to the other. Six years later, the patient is mobilizing well and engaging in sporting activities with her peers in a mainstream school. Clinical evaluation of motor and sensory modalities demonstrated a good functional result. Quality of life was assessed using the short form-36 health survey and lower extremity functional scale disclosing a high level of social and physical capacity. Functional magnetic resonance imaging was performed and showed cortical integration of the limb; the implications of cortical plasticity and vascularized composite allotransplantation for the correction of congenital limb anomalies are presented.

Long-term urological outcomes in six sets of conjoined twins

AIM

To review the long-term urological outcomes of six sets of ischiopagus and pygopagus conjoined twins. Emphasis is placed on the particular genitourinary challenges of separation, reconstruction and monitoring of these patients.

PATIENTS AND METHODS

We performed a longitudinal, retrospective analysis of six sets of conjoined twins who presented to a single center and describe their long-term urological outcomes.

RESULTS

Six sets of ischiopagus (4) and pygopagus (2) conjoined twins presented from 1993 to 2003 and have been followed up for a mean of 12 years (range 7-17 years). Separation was achieved in 5/6 cases; the remaining one died of intestinal perforation and resultant sepsis. One further child died of malaria after separation. Patterns of genitourinary anatomy found in these conjoined twins are described. Urinary continence was achieved in 2/6 ischiopagus and 3/4 pygopagus twins. Renal failure has developed in one child. Urinary tract infections have been common. Secondary urological surgery has been required in 3/6 ischiopagus twins, usually to perform an incontinent urinary diversion.

CONCLUSION

Complex urological problems occur in ischiopagus and pygopagus conjoined twins. Beyond the challenge of surgical separation, they continue to provide management challenges requiring secondary reconstructive surgery and close urological monitoring.

What is a waddling gait?

PURPOSE

A patient's gait can provide important diagnostic and functional information. Though 'waddling gait' is a long-established concept, we question whether this description is precise or clinically useful.

METHODS

We searched 'waddling gait' in all main medical specialties core textbooks, in animal locomotion books and in Medline, Healthstar and Embase. Further we obtained expert advice on the gait of ducks.

RESULTS

Many names are used for 'waddling gait', and its description is imprecise and inconsistent. Trendelenburg described it as a pelvic drop on the side of the swinging leg and compensatory lateral trunk bending towards the side of the standing leg. Many conditions have been described as producing a waddling gait. We accepted the gait pattern of ducks as being true waddling. This often-used comparison does not accurately reflect the gait pattern seen in humans with a range of medical disorders; nor is it the same as a Trendelenburg gait.

CONCLUSIONS

As we have found no condition in which patients have a truly duck-like gait, we propose that the phrase 'waddling gait' should be abandoned. We suggest that for clarity and good communication, clinicians should describe the observed elements of the gait rather than using imprecise and unhelpful terms such as 'waddling gait'.

Ischiopagus tetrapus conjoined twins: 22 years after separation

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.

Acute abdominal pain in a separated conjoined twin

Complications of conjoined twins are typically events surrounding the birth and surgical separation. We report an unusual late-onset complication, a grade IV duodenal disruption of the accessory system in a formerly conjoined twin. Because conjoined twins have unique anatomy based on the junction and division of organs, one must always consider a multitude of causes for common complaints. Basic operative principles apply: the acute abdomen must be explored. Finally, to avoid these complications, removal of all or nearly all parasitic structures must be considered at the initial separation.

The embryology of conjoined twins

INTRODUCTION

Attention is drawn to the spontaneous incidence of twinning, both dizygotic and monozygotic in different mammalian species. Conjoined twinning, however, only arises when the twinning event occurs at about the primitive streak stage of development, at about 13-14 days after fertilisation in the human, and is exclusively associated with the monoamniotic monochorionic type of placentation. It is believed that the highest incidence of conjoined twinning is encountered in the human. While monozygotic twinning may be induced experimentally following exposure to a variety of agents, the mechanism of induction of spontaneous twinning in the human remains unknown. All agents that are capable of acting as a twinning stimulus are teratogenic, and probably act by interfering with the spindle apparatus.

DISCUSSION

The incidence of the various types of conjoined twinning is discussed. Information from the largest study to date indicates that the spontaneous incidence is about 10.25 per million births. The most common varieties encountered were thoraco-omphalopagus (28%), thoracopagus (18.5%), omphalopagus (10%), parasitic twins (10%) and craniopagus (6%). Of these, about 40% were stillborn, and 60% liveborn, although only about 25% of those that survived to birth lived long enough to be candidates for surgery. Conjoined twinning occurs by the incomplete splitting of the embryonic axis and, with the exception of parasitic conjoined twins, all are symmetrical and "the same parts are always united to the same parts". Fusion of monozygotic twins is no longer believed to be the basis of conjoined twinning. Accounts are provided of the anatomical features of each of the commonly encountered varieties.

Ischiopagus and pygopagus conjoined twins: neurosurgical considerations

BACKGROUND

Neurosurgeons are familiar with the challenges presented by craniopagus twins, but other types of conjoined twins may also have neurosurgical implications. We report our experience in the management of ischiopagus and pygopagus conjoined twins.

METHODS

This is a retrospective review of the management of conjoined twins at Red Cross Children's Hospital in Cape Town, South Africa.

RESULTS

Twenty-three pairs of symmetrical conjoined twins were managed over a 40-year period (1964-2003), of which 16 (70%) were separated. Of these cases, 6 are the focus of this study, namely 4 pairs of ischiopagus twins and 2 pairs of pygopagus twins seen between 1993 and 2003. In 2 cases, there was direct involvement of the nervous system at the site of union, with 1 pair of ischiopagi manifesting end-to-end union of their spinal cords, while a pair of pygopagi had back-to-back fusion of the conus. Another pair of ischiopagi had a fused dural sac without joined neural elements, but one of these children developed syringomyelia 2 years after separation. Neuroimaging was invaluable in detecting these abnormalities. The one pair of ischiopagi who died before separation were HIV positive and had severe brain atrophy and cystic encephalmalacia at autopsy. Nine of the 12 children (75%) had bony abnormalities of the spine remote from the area of conjunction. The most common finding was the presence of hemivertebrae, usually in the thoracic spine. Six children manifested scoliosis, which has already progressed in the oldest two. Technical aspects such as timing and sequence of separation, the division of neural tissues and reconstruction are discussed, as are the long-term complications of their spinal abnormalities.

CONCLUSIONS

Ischiopagus and pygopagus conjoined twins manifest an interesting array of spinal abnormalities, which present challenges, not only at the time of separation, but also in their long-term management.

Perineal reconstruction of female conjoined twins

BACKGROUND/PURPOSE

Conjoined twins are some of the most challenging patients faced by surgeons. Pygopagus and ischiopagus twins present particular gastrointestinal and genitourinary reconstructive challenges. This study reviews the authors' experience with the perineal reconstruction of these types of conjoined twins.

METHODS

Retrospective analysis was performed for 3 sets of female conjoined twins undergoing separation between 1999 and 2001. Particular attention was given to the separation and reconstruction of the distal gastrointestinal and urogenital structures.

RESULTS

Three sets of female conjoined twins underwent successful separation 2 pygopagus, one ischiopagus tripus) with 5 surviving infants. The sixth infant died of congenital anomalies incompatible with life. Four of the 5 surviving infants had diverting enterostomies. Two of these enterostomies have been closed. Perineal reconstruction consisted of anoplasty (5 of 5), vaginoplasty (4 of 5), and urethroplasty (4 of 5). Although fecal and urinary continence are not completely measurable at this age (<3 years), all 5 survivors void spontaneously. Three infants with intestinal continuity have apparently normal defecation without the need of a bowel regimen.

CONCLUSIONS

With careful preoperative planning and a multidisciplinary team of pediatric surgeons and urologists, satisfactory reconstruction and functional outcome of the female perineum can be achieved in conjoined twins.

Congenital vertebral anomalies in ischiopagus and pyopagus conjoined twins

A review of clinical records and radiographs revealed that five of 10 patients with conjoined twinning (three of six ischiopagus and two of two pyopagus twins) had congenital vertebral anomalies including hemivertebrae (3), multiple thoracic anomalies (1), right hemisacral agenesis (1), and three lumbar vertebra (1). No mirror image anomalies were identified, and different regions of the spine were involved in the two cases in which both twins had anomalies. Coexisting visceral and musculoskeletal anomalies included dextrocardia (3), atrial septal defect (1), congenital vertical talus (2), Sprengel's deformity (1), and multiple unilateral foot anomalies (1). Hip subluxation or dislocation was seen in five of eight ischiopagus or pyopagus twins after separation and required femoral and pelvic osteotomies. Lumbar scoliosis not associated with congenital vertebral anomalies was seen in two ischiopagus twins. These observations suggest an association between ischiopagus and pyopagus conjoined twins and congenital vertebral anomalies, and their coexistence is explained best by a nonspecific teratogenic insult during early embryogenesis.

Separation of brachio-thoraco-omphalo-ischiopagus bipus conjoined twins

Separation of 3-year-old brachio-thoraco-omphalo-ishiopagus bipus conjoined twin girls is reported. Detailed preoperative assessment and a multidisciplinary approach were essential prerequistes to surgery. The difficulties of managing the extensive body wall defect resulting from separation are discussed. Despite the use of subcutaneous and intraperitoneal tissue expanders, a large area of prosthetic material was required to reconstruct the abdominal wall. Skin cover was achieved using a combination of meshed allogeneic skin, homograft split skin, and autologous cultured keratinocytes. One twin died in the early postoperative period, but the other has recovered well and is awaiting further rehabilitative treatment.