Moral permissibility as a guide for decision making about conjoined twins.

D ecisions about whether to proceed with a therapy often center on whether the benefits of therapy exceed the burdens of therapy. The question in the case presented by Tirotta et al. (1) is whether to proceed with palliative open heart surgery in Twin A of surgically inseparable conjoined twins (Twin B had normal cardiac anatomy). Despite recommendations to the contrary, the parents chose surgery. Because what happens to Twin A happens to Twin B, this scenario skirts the dilemma of how to proceed when the interests of conjoined twins collide. Nonetheless, it is likely that the specter of conjoined twins affected decision making. One possible reason for recommending against surgery is the presumed medical (decreased likelihood of a successful outcome) and social (decreased value of successful clinical outcome) consequences of being conjoined twins. Rather than speculate on what may have happened in this case, it makes more sense to consider these and other issues in light of a more complete case. Jodie and Mary were ischiopagus tetrapus twins attached at the lower pelvis (2). Because Mary’s heart and lungs were underdeveloped, she was dependent on Jodie’s aortic arterial circulation for life. It was thought that if left together, Jodie and Mary would probably live only a few months and no more than a few years. If separated, it was likely that Jodie would have a relatively normal life; it was certain that Mary would die. Citing deeply held religious beliefs forbidding intentionally causing death, the parents chose not to separate the twins. The physicians thought that it would be in Jodie’s best interests to separate them, however, and brought the matter for legal review. The British Judges ruled that the twins should be separated. People react in one of two ways upon hearing this story. Some recoil in horror at the idea that one child could be killed for another, even under these circumstances. Others take a utilitarian approach, insisting that it is far better to save one child. These two positions highlight the most pertinent ethical questions. May we separate Jodie and Mary if it will result in the death of Mary, and must we separate Jodie and Mary if it is the only way Jodie may survive? Conjoined twins are commonly conceptualized as Entangled Singletons, two individual people who are tragically ensnared (2,3). This conceptualization implies that their situation is unnatural and undesirable and demands rectification through separation. It also implies that Jodie and Mary are individuals without interpersonal obligations except those willingly assumed by sisters. This is the underlying approach of most medical and legal analyses. A minority view, worth noting if only to emphasize that the entangled singleton view is not unimpeachable, is that conjoined twins are not simply “two of us, entangled” but are something essentially different, perhaps “two psychologically separate individuals who happen to share a body, the sharing of the body being integral to the individuality of each twin. ” (3) Conjoined twins, then, are sufficiently different such that singletons cannot adequately imagine the advantages and disadvantages of being conjoined twins. Applying a singleton version of risks and benefits for conjoined twins is thus faulty, meaning, ultimately, that we cannot assume that the primary goal should be separation. This analysis will proceed using the entangled singletons conceptualization. Questions on whether it is morally permissible to separate Jodie and Mary center on the death of the weaker twin, Mary (4). One argument in favor of permitting separation is familial altruism, in that we can imagine that Mary may willingly forgo what may remain of her short life to secure the possibility of a longer life for her sister, Jodie. Such behavior is often considered morally permissible within the unique family relationship. Supported, in part, by salary from the Department of Anesthesiology, Perioperative and Pain Medicine, Children’s Hospital Boston. Accepted for publication November 29, 2004. Address correspondence and reprint requests David B. Waisel, MD, Department of Anesthesiology, Perioperative and Pain Medicine, Children’s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115. Address e-mail to david.waisel@childrens.harvard. edu.