Scalp allotransplantation refers to transfer of scalp tissues from brain-dead donors to living recipients. Scalp defects can result from tumor resection, trauma, and burn injuries. To reconstruct scalp defects, various reconstructive methods have been used, including flap operations, skin grafts, and tissue expansion. However, traditional methods of scalp reconstruction have many limitations. Therefore, scalp allotransplantation could be a promising alternative.

Tissue expansion can be used to reconstruct the scalp using the uninjured portion of the remaining scalp. This approach does not work; however, in defects involving greater than 50% of the scalp by area. Free-flap operations can reconstruct such large scalp defects, but the cosmetic outcome is unsatisfactory because the free flap will not match in skin texture, color, and hair growth.

Scalp allotransplantation is a composite tissue allotransplantation, including the hair of donors. The operation has been reported in just two cases in the literature. The first case was between monozygotic twins who had no need for immunosuppressive therapy, in which two flap operations were performed based on the superficial temporal artery. The transplant was successful and hair growth from the flap was observed after long-term monitoring [1]. The other case was that of a 72-year-old woman with stage IIIC recurrent cutaneous malignant melanoma of the parietal scalp. The patient was treated with a wide excision, including part of the scalp, the face, the neck, and both ears. The resulting defect was reconstructed using a composite tissue allotransplantation, including both ears and the scalp from a young man who had been declared brain dead [2].

Patients who undergo scalp allotransplantations need continuous immunosuppressive therapy that can pose life-threatening complications. Unlike other organ transplants such as kidney or liver, the functional or cosmetic improvement due to a scalp transplant does not extend a patient's life. Thus, scalp allotransplantation raises ethical questions [3]. Furthermore, patients may have ethical objections or experience mental distress due to the fact that the scalp was removed from a brain-dead person [4]. Therefore, it is important to objectively measure and evaluate the level of risks and benefits of composite tissue allotransplantation before actual application.

Recent studies have reported gaps in the knowledge regarding risk acceptance and expectations for composite tissue allotransplantation between experts and non-experts in a number of countries. In South Korea, similar studies have been conducted to evaluate risk acceptance and expectations for allotransplantation of the face, hands, feet, and larynx [5,6,7]. However, no such survey study has been performed on scalp allotransplantation within South Korea.

Although scalp allotransplantation presents minimal surgical difficulty, the procedure is as complex as any organ transplantation due to the issues related to immunity. First, serological screening tests and ABO blood typing need to be performed to assess immune compatibility between donors and recipients. In addition, donor-recipient compatibility must be evaluated for age, skin tone, gender, race, and tissues dimensions. If a compatible donor is found, the composite tissue must be obtained, transported, and transplanted into the recipient while minimizing ischemic time. Transplantations requires intensive care by a multitude of healthcare personnel during the early postoperative period, including monitoring of the blood flow in and out of the transplanted organ. Tissue rejection can occur despite adequate immunosuppressive regimen, which may necessitate removal of the graft. No episode of acute rejection has been reported for the two cases of scalp allotransplantation, but recipients must remain on lifelong immunosuppressive therapy and need to be carefully monitored for occurrence of chronic graft versus host disease.

Compared to solid organ transplantation, scalp allotransplantation is challenged by a different set of problems. First, scalp transplant does not extend life, which raises ethical questions for patients whose life may be shortened due to immunosuppressive management [9]. Second, it is difficult to find a donor due to the cultural issues surrounding the procurement of scalp. A third difficulty is the selection of a recipient with good compliance for a successful scalp allotransplantation. The recipient will need to undergo screening for clear understanding of the risks and benefits through psychiatric evaluations, such as for schizophrenia, and an IQ test [10].

A "frame of reference" can be defined as a set of ideas, beliefs, and/or views that is used for predicting a conclusion in psychological terms and for making decision. Barker et al. suggested that since such frame of references should be observed for various groups involved in transplantations (laypersons, potential patients, physicians, etc.) because those frames modify the perception of the risks and benefits of transplantation [11]. In our study, the differences in risk acceptance and expectations for scalp transplantation across the groups most likely reflect the differences in frame of reference across the four groups.

In our study, the kidney transplantation group gave acceptable scores on the survey for risk acceptance and expectations, which seemed to indicate that they already understood immunosuppressive therapy through direct experience. Such personal experiences seems to have raised the consensus threshold value for risk acceptance. It is important to note, however, that only kidney transplantation survivors were included as group members, and the results may reflect a selection bias for positive outlook.

In contrast, the general public group gave relatively higher risk acceptance and expectation scores, which seemed to be mainly related to a lack of practical knowledge on the subject matter. Since most of the general public has little or no in depth knowledge about scalp allotransplantation, the survey evaluators had to provide additional explanations regarding scalp allotransplantation and immunosuppression during the survey.

Participants who had received scalp reconstruction responded differently from the transplant patients and the general public. This could be because scalp reconstruction patients felt that the numerous adverse reactions of immunosuppressive therapy, risks of histoincompatibility and additional surgery could not justify their adjusted status. Though inconvenient, the patients had adjusted to covering up the unsightly portions of the scalp with wigs or hats.

Furthermore, satisfaction related to operative outcomes was a factor that was different between the kidney transplantation group and post-scalp reconstruction group. Since scalp is not a vital organ as kidney, the defect of scalp only needs to be covered with intact skin, with or without hair. On the other hand, kidney transplant surgery not only resolves the inconvenience of dialysis but also extends the lives of chronic kidney disease patients. Therefore, the kidney transplant group was more satisfied with outcomes of their treatment and may have responded more positively for this reason.

Of the 4 groups, the group consisting of physicians demonstrated the lowest levels of risk acceptance and expectations. These participants were well aware of limitations due to gaps between expectations and outcomes; thus, they seemed to consider the adverse reactions of immunosuppressive therapy and histoincompatibility as unacceptable in return for an improvement in appearance.

Limitations of this study include the constraints of survey sample groups and geographic region. The general public group in the study was comprised of individuals visiting family members in the outpatient department, who could have a chance of bias depending on the severity and types of diseases experienced by the relative. A sample from the population outside of the hospital might better represent the general population. In particular, the general public group should be selected in consideration of more varied demographic and socioeconomic status.

The present study found results, which echo findings from other international studies and that from the allotransplantation conducted within South Korea [5,6,7,12]. Despite differences in transplantation type and study populations, the fact that study results were similar indicates that the most influential factor could be "expectations" of the general public group with the lack of knowledge regarding subject matter. Therefore, it is important for patients to fully understand the various difficulties of scalp allotransplantation before surgery to allow each individual to evaluate whether or not the post-transplant outcomes are acceptable.

For scalp transplantation to be a viable practice in modern medicine, physicians should not solely focus on the adverse reactions of immunosuppression and low expectations, but also increase the effort on minimizing such risks and on satisfying the cosmetic or functional requirements of patients. In addition, the public should be informed against the unrealistic expectations of allotransplantation based on incorrect portrayal from popular media.

The present study investigated differencesin the risk acceptance and expectations of scalp allotransplantation in specific sub-groups of the South Korean population and has found findings similar to those of other populations.

Scalp allotransplantation is feasible operation for large scalp defect patients. However, physicians must understand the differences in risk acceptance and expectations across various groups of the lay public and recognize the advantages and disadvantages of scalp allotransplantation.