Preoperative CT angiography to facilitate pedicle selection for high-risk breast reduction patients

Section: Breast Abstract Introduction: Large volume breasts, and also breasts with a long distance between the sternal notch and the nipple, have a higher risk of postoperative nipple necrosis after breast reduction surgery. This is due to vascular insufficiency. For these high-risk cases, free nipple grafts are sometimes performed. Free nipple grafts are not an ideal technique due to reduced sensation, duct disruption, variable take and common result of an under-projecting nipple and poor aesthetic outcome. In order to avoid both necrosis of the nipples and the use of free nipple grafts, we have investigated the use of angiographic computerized tomography (CTA) in the selection of the dominant blood supply in breast reduction pedicle selection. The first aim of this study was to investigate the dominant vascular supply to the nipple areolar complex (NAC) using CTA. The second aim was to investigate whether the preoperative CTA could change surgical planning and also reduce the incidence of nipple necrosis after breast reductions for patients considered to be at a high risk of nipple loss.


Introduction
Reduction mammoplasty is a procedure undertaken primarily to reduce the volume of the breasts while maintaining the aesthetics and function of the organ. 1 Women suffering from hypertrophic breasts improve their quality of life-physically, psychologically and also psychosocially-after breast reduction surgery even though complications are common and the most feared complication is necrosis of the nipple areolar complex. Large-volume breast reduction, long sternal notch to nipple distance and revisionary breast reductions all have a higher risk of postoperative nipple necrosis. [2][3][4][5][6] The technique of removing the nipple and replacing it as a full thickness graft is sometimes considered in these high-risk procedures. 5 However, free grafting is associated with disruption of the ductal system, reduction in sensation of the nipple areolar complex (NAC) and a generally less optimal aesthetic outcome.
The vascular supply to the nipple is an essential consideration in surgical planning to avoid the complication of nipple necrosis. 5,[9][10][11][12][13] Previous studies of the dominant vascular pedicle have been limited to a small number of cadaver dissections [10][11][12] and, more recently, MRI analysis. 13 The aim of the present study was firstly to investigate the vascular supply to the NAC using angiographic computerised tomography (CTA) 14 and secondly to investigate if the preoperative CTA could change the surgical planning to reduce the incidence of nipple necrosis after breast reductions in patients considered to be in at a high risk of nipple loss.

Phase 1: Determination of the blood supply to the NAC
Using a dataset of all female CT thoraces performed at a single centre between January and May 2013, based on the following selection criteria (n=132): • the patient was a physically developed female • at least one breast and potential blood supply was visible in extended fields      3 This is especially true if the breast volume is very high and the breast is ptotic, which will result in a long pedicle, and therefore a long distance for the blood to reach the NAC.  The level of patient exposure to ionizing radiation of the CTAs performed in the study was 3-6mSv. This is the same or less than the average annual background radiation exposure and equates to 2mSv. 14 Therefore we consider the possibility of avoiding nipple necrosis in higher-risk breast reductions outweighs the problems associated to the limited exposure of radiation during the CTA.
As the dominant blood-supply to the NAC is identified, the surgeon can individualise the surgical planning of the direction of the pedicle. The complications reported in this series of cases are in line with previously reported lower-risk breast reductions. 3 In these cases, NAC integrity has been maintained in a group of women considered to be at higher risk of necrosis of the NAC.
The weakness in this study is the lack of randomisation which means that we cannot be sure that the result would have been the same if another pedicle was chosen. The small numbers in the clinical series reflect the relative rarity of these higher-risk cases. However, the single case that did have partial necrosis to the nipple could indicate that it might be better to plan surgery and the type of pedicle based on the dominant vessel to the NAC.
The number of patients is also small which can, by chance, give the low incidence of complications seen in this study.

Conclusion
Preoperative CTA for high-risk breast reduction may be a useful surgical planning tool. With the insight gleaned from the CTA, pedicle design could be tailored to the individual's anatomy. This surgical planning may reduce the incidence of necrosis to the NAC in the women who have a higher risk of nipple areolar necrosis.