Patient-controlled needle-free carbon dioxide insufflated breast expander implant (Aeroform®, AirXpanders®) in breast reconstruction: multi-surgeon prospective case series

Insertion of patient-controlled needle-free carbon dioxide insufflated breast expander implants (Aeroform®, AirXpanders®) The expander is inserted during a surgical procedure under general anaesthetic which takes approximately one hour. The incision used is generally the existing incision from the preceding mastectomy. After the surgical procedure, patients are usually discharged 1-2 days postop. There is a clinic visit one week and two weeks postop. If wound healing is satisfactory at the two-week visit, women are provided with the hand-held remote control and provided with training about the expansion process. Training is one-on-one with the surgeon and takes approximately 5 minutes. The patient is shown how to push the button, educated about the safety lockout features, and told to seek medical attention if there is excessive pain or changes in the wound such as gaping or redness. Training is supplemented with a take-home booklet, a product support phone helpline, and a product website if further information is required. Patients are booked back into clinic every 4 weeks to check on progress. When expansion is complete, they are booked for the surgical procedure to replace the expander with their final implant. Expansion is complete when the expander has reached its full capacity (400cc for the small size, 600 cc for the medium size and 800cc for the large size) or when the patient has reached their desired breast size if this occurs earlier. The size of the expander largely depends on the patient's previous breast size, as this determines the size of the available skin pocket to hold the expander. The surgeon will be performing the surgery and seeing the patient at the followup visits. Expansion will be carried out by the patient using the hand-held remote. The general anaesthetic for surgery will be proved as per the routine protocols at GCHealth. The actual drug doses, frequency, and mode of administration will be at the discretion of the anaesthetist of the day. Immediate postop routine analgesia includes regular paracetamol plus oral opiates as required (typically Endone 5mg q6h prn) with additional analgesia as charted by the acute pain team, which is part of the clinical pathway. After discharge home and through the expansion period, patients do not need anything more than paracetamol prn. The expansion is initiated by the patient depending on their own comfort. 10cc of gas is released each time the button on the remote is pressed, there is a 3-hour lockout between doses, and a 24-hour lockout after the third dose. Other than this there is no 'schedule' and patients can expand as quickly or slowly as they wish. Adherence is not expected to be an issue as patients who undergo this surgery are usually very motivated to complete the expansion as part of their breast reconstruction journey. The AirXpander has a maximum duration of 6 months after insertion (the same as for saline expanders) but many patients have completed expansion at the first 4 week check. Previous experience with saline expanders show that non-completion of expansion is most commonly due to unexpected significant health events that make the patient unfit for further surgery, and not because the patient does not comply with treatment. The device is a standard expander shell, but without a saline injection port. Instead, it contains a small canister containing compressed carbon dioxide which is actuated through a hand-held remote controller. With saline expanders, patients receive 100 mL injections of saline through the skin into the injection port. With the AirXpander, 10mL is released each time the button on the remote is pressed, capped at 30mL per 24 hours. Thus the previous 100mL volume can be delivered in 3.3 days. Previous studies also show that expansion times are shorter because it is possible to expand 210mL over 7 days- more than twice as much as a 100mL saline injection. So patients can expand faster or slower than the usual saline expansion schedule, in the comfort of their own homes, without further clinic visits or skin punctures. Breast size can also be very accurately calibrated because the AirXpander allows breast size to be changed by increments of 10mL, and patients can pause expansion for a few days to 'live with' their chosen breast size and decide if they wish to keep expanding or stop.