Breast enlargement can adversely affect women physically and mentally. Over the last few decades, breast reduction surgery techniques became numerous to treat such condition. However, every reduction mammoplasty technique has its advantages and disadvantages with necrosis of NAC being the most undesirable complication due to poorly vascularized pedicle [6].
Traditionally recognized “safer” and more familiar techniques such as inferior pedicle and free nipple grafting in very large reductions, have already become well accepted methods to minimize nipple loss. However, NAC necrosis was still reported even with those techniques. Moreover, loss of NAC sensation is a well-established complication in those underwent free nipple grafting a technique that also interrupts breast ductal system as well [7, 8].
Different imaging modalities was therefore suggested by to delineate the dominant arterial supply to NAC before surgery to facilitate pedicle selection and minimize necrosis of NAC [9]. Such, imaging techniques included handheld doppler, duplex ultrasonography both of which are time consuming, operator dependent and does not provide clear angiographic roadmap to surgeons.
Being a well-established noninvasive vascular imaging modality, multislice CT has been widely used to image different body vasculature due to its wide availability, rapid acquisition times, different reconstruction techniques which resembles angiography images to which surgeons’ eyes are familiar with [10]. Our study aimed to use such imaging modality to delineate dominant arterial supply to NAC to facilitate pedicle selection and hence aiming to improve patient’s outcome.
In our study MIP images in axial plane was helpful to delineate the entire course of the dominant arterial supply from its origin to NAC within single thick-slab image (Fig. 3). However, certain patients specially the young ones who have dense glandular tissue may interfere with tracing of such arteries till NAC due to increased density of breast parenchyma (Fig. 4), an issue that could be problematic as well in patients with breast edema. Three-dimensional volume-rendered images in axial and coronal projections with semitransparent mode was helpful to delineate dominant arterial supply to NAC in relation to bony structures and to determine its entry point at NAC as well (Fig. 5).
Our study found that IMA perforators are the most dominant supply to NAC in 21 breasts (87.5%) followed by LTA dominance in 4 breasts (16.6%) with the remaining NAC being supplied dominantly by anterior intercostal arteries (4.1%) and thoracoacromial artery (4.1%). Such results are matching with Stirling et al. [11] results who found the same dominant arterial supply in their study. We also found difference in dominant arterial supply between right and left breast of the same individual in 6 (50%) of our cases. There was variability in the course of arterial supply of NAC in all cases as well. In another anatomical study done by van Deventer [12], he found an asymmetrical pattern of blood supply to breasts with variation between right and left breasts in the same cadaver and hence concluded that it is impossible for surgeon to predict the blood supply of the breast that will operate upon. Our study solved these variability of the blood supply and facilitated the dominant breast pedicle selection.
Based on CTA findings in our study regarding dominant arterial supply to NAC, surgeons used superomedial pedicle technique in 19 breasts (79.2%), lateral pedicle in one breast (4.1%), superior pedicle in two breasts (8.3%). Our study was helpful as well to determine the entry point of the dominant artery into NAC using clock method. One breast showed no dominant arterial supply to NAC and inferior pedicle was considered safer based on entry point of different arteries to NAC which were more numerous at 7 O’clock position. The determination of arterial entry point to NAC was helpful as well to preserve as much of vascularized pedicle tissue during dissection to ensure viability of NAC thereafter.
None of the cases enrolled in our study experienced partial or total NAC necrosis after breast reduction surgery. The technique described in this study encompassing pre-operative detection of dominant artery to NAC, describing its course and entry point at NAC, then tailoring operative markings and dissection pattern accordingly to include them in the desired pedicle, has led to reduction of dissection time during surgery as surgeon already knows about the dominant artery and its entry point at NAC.
As regard radiation dose, we used 100 kv setting in all patients to minimize radiation dose considering that breast is a radiosensitive structure and most of our enrolled patients were of young age. The effective dose ranged from 3 to 6 mSv which is nearly the same or even less than annual background radiation exposure. Therefore, we consider the benefit of avoiding nipple necrosis postoperatively outweighs the risk of limited radiation exposure during pre-operative CTA.
The major limitation of our study was the small number of cases, an issue that could describe the low incidence of complications in this study. Further studies with larger number of patients may be needed to compare the actual incidence of complications following breast reduction surgery planned with CTA to those who underwent surgery without pre-operative CT imaging, in order to validate the routine usage of CTA before such surgery.