As with all surgical operations, careful patient selection is paramount to the successful implementation of RAP. Patients should be carefully evaluated preoperatively and RAP only offered to those considered suitable. Multidisciplinary management with an endocrinologist is essential. The diagnosis of pHPT needs to be confirmed by demonstrating a raised serum calcium and parathyroid hormone (PTH). Vitamin D deficiency and Familial Hypocalciuric Hypercalcemia (FHH) need to be excluded by measuring serum vitamin D levels and 24-h urine calcium:creatinine clearance ratios respectively as these do not require surgical intervention [2].

There are parathyroid specific as well as generic considerations for RAP. With regard to the parathyroid, the indications for RAP are the same as for any targeted parathyroidectomy approach. Hence, RAP should only be offered to patients who have pHPT with a preoperatively localized adenoma. The authors advocate triple modality concordance as a prerequisite using ultrasonography, sestamibi scintigraphy and single-photon emission computed tomography (SPECT-CT) to minimize the risk of failure. However, it is likely that dual modality concordance (with ultrasonography and sestamibi scintigraphy) is just as adequate. The accuracy of localizing a single adenoma is reported to be 94–99 % with this modality [2].

There is no limitation to the size of the adenoma, and contrary to thyroid nodules that can reach a very large size, parathyroid adenomas are usually relatively small. RAP should not be offered to patients where there is suspicion of malignant disease, a coexistent large goiter ipsilaterally, history of previous neck surgery or irradiation and to those with a large body habitus. Relative contraindications to RAP include ipsilateral degenerative shoulder pathology or significant co-morbidity placing them in an American Society of Anesthesiologists (ASA) category greater than 2. The contraindications to RAP are summarized in Table 1.

The location of the parathyroid adenoma (including extracervical—ectopic location) is not a contraindication and a robotic-assisted thoracoscopic approach has been described to remove ectopic parathyroid adenoma in the mediastinum [20–23]. This approach is beyond the scope of the chapter.

The ideal RAP patient would be a slim female with a preoperatively localized parathyroid adenoma showing concordance on at least 2 imaging modalities.

As with all surgical operations, informed consent is essential and should be undertaken by the attending surgeon. The literature supports that RAP is as safe as conventional parathyroidectomy [2, 3, 16, 17, 24, 25]. The risks associated with RAP are the same as for conventional parathyroidectomy with regard to the recurrent laryngeal nerve, infection, hematoma and hypoparathyroidism. Despite the anaerobic nature of the axilla, the literature does not support an increased infection rate with RAP compared to cervical parathyroidectomy [2, 3, 16, 17, 24, 25]. This “shifting” of the incision does however significantly prolong the operative time as a long subcutaneous flap must be raised to reach the neck and this should be explained to the patient. This may be associated with sensory changes of the overlying skin and higher pain scores and dysesthesia over the area of subcutaneous dissection. These symptoms are usually temporary [2, 16].

The two different approaches should be explained during the consent process. In general, the transaxillary incision is recommended for females because of breast concerns. For males, an infraclavicular incision can be used instead. The approach needs to be decided in conjunction with the patient at the time of obtaining their informed consent.

In the event of a post-operative hematoma, this is less likely to lead to airway obstruction because the potential space for the hematoma to disseminate is so capacious compared to cervical parathyroidectomy.

Another important point that the patient needs to be made aware of is the potential complication of developing a brachial plexus neurapraxia. The postulated mechanism is a traction injury when the ipsilateral arm is raised to reduce the distance between the axilla and anterior neck [26, 27]. This stretch injury is rare and can be prevented by adjusting the position of the ipsilateral arm with the patient awake to assess for comfort [28]. The back of the patient’s hand is positioned so that it is touching the central portion of the forehead. This is known as the “extended salute” position.

RAP achieves the objective of “shifting” the incision from the neck to the axilla or infraclavicular area at the expense of an increased operative time. The inpatient stay and time off work are similar to the conventional open technique [3, 16].