Is There a Need for Preoperative Imaging of the Internal Mammary Recipient Site for Autologous Breast Reconstruction?

Expanding the use of internal mammary artery perforators as a recipient vessel in free tissue transfer: An anatomical analysis by computed tomography angiography in breast cancer patients

BACKGROUND

The internal mammary artery (IMA) perforator has assumed recent prominence as recipient vessels in free autologous breast reconstruction. However, anatomical understanding is unclear, due to limited cadaver and clinical studies. We evaluated the usability of these vessels by evaluating perforator size, dominance, laterality, interspace location, and relationship with breast volume.

METHODS

A retrospective review assessed 197 female patients with breast cancer who had undergone computed tomography angiography (CTA) of the chest wall. The average age and body mass index (BMI) of patients was 49.0 ± 6.5 years and 24.2 ± 5 .8 kg/m² , respectively. The average volume of breasts was 437 ± 190 mL. Our analysis focused on the anatomy of IMA perforator and its relationship to volume and BMI.

RESULTS

A total of 377 hemi-chest evaluations were performed. Most patients (95.5%) had sizeable perforating artery identified on CTA. Among all sizeable perforators identified, the mean diameter of the most dominant arterial perforator was 1.8 ± 0 .8 mm. The right hemi-chest had significantly larger perforators than the left (1.9 ± 0 .9 mm vs. 1.7 ± 0 .7 mm, p = 0.002). The first intercostal space (ICS) had a slightly greater of perforators than second ICS (34.6% vs. 29.8%, p = 0.172). However, second ICS had a greater number of most dominant perforators compared to first ICS (38.9% vs. 34.7%, p = 0.357). Perforators from first ICS emerge medial to the sternal edge and breast footprint. When dividing groups with 0-1 versus 2-3 reliable perforators, breast volume was significantly higher in the later (422.0 mL vs. 461.2 mL, p = 0.019).

CONCLUSION

These results are expected to encourage microsurgeons to use the IMA perforator by providing a clear anatomical roadmap.

The ideal intercostal space for internal mammary vessel exposure during total rib-sparing microvascular breast reconstruction: A critical evaluation

BACKGROUND

Total rib-preserving free flap breast reconstruction (RP-FFBR) using internal mammary vessel (IMV) recipients usually involves vessel exposure in the second or third intercostal spaces (ICS). Although the third one is more commonly used, no direct comparisons between the two have hitherto been performed.

OBJECTIVES

To compare the in-vivo topography and vascular anatomy of second and third ICSs in patients undergoing FFBR using the rib-preservation technique of IMV exposure.

METHODS

An analysis of prospectively collected data on intercostal space distance (ISD), number and arrangement of IMVs, location of venous confluence, and vessel exposure time was conducted on a single surgeon's consecutive RP-FFBRs.

RESULTS

A total of 296 RP-FFBRs were performed in 246 consecutive patients. The second, third, or both second and third spaces were utilized in 282, 28, and 22 cases, respectively. The ISDs were 20.6 mm ± 3.52 for the second ICS and 14.0 mm ± 4.35 for the third ICS (p<0.0001, CI = 5.17-7.97, t-test). The second versus third ICS vein content was as follows: single 81.4% vs. 74%, dual 18.6% vs. 26%, and confluence 3.7% vs. 13%. The second ICS single vein was medial to the artery in 92.6%. The third ICS single vein was medial to the artery in 88.2% Vessel exposure times for second (47.2 mins ± 26.7) and third (46.5 mins ± 31.4) spaces were similar (p = 0.93). The overall intraoperative anastomotic revision rate was 9.1%, and the postoperative flap re-exploration rate was 4.0%, with 99.7% overall flap success.

DISCUSSION AND CONCLUSION

Preferential use of the second ICS is supported by its more predictable vascular anatomy, a broader space for performing the microanastomoses and a higher frequency of a single postconfluence (and thus larger) vein facilitating the microsurgery.

MRA of the skin: mapping for advanced breast reconstructive surgery

Autologous breast reconstruction using muscle-sparing free flaps are becoming increasingly popular, although microvascular free flap reconstruction has been utilised for autologous breast reconstructions for >20 years. This innovative microsurgical technique involves meticulous dissection of artery-vein bundle (perforators) responsible for perfusion of the subcutaneous fat and skin of the flap; however, due to unpredictable anatomical variations, preoperative imaging of the donor site to select appropriate perforators has become routine. Preoperative imaging also reduces operating time and enhances the surgeon's confidence in choosing the appropriate donor site for harvesting flaps. Although computed tomography angiography has been widely used for preoperative imaging, concerns over excessive exposure to ionising radiation and poor iodinated contrast agent enhancement of the intramuscular perforator course has made magnetic resonance angiography, the first choice imaging modality in our centre. Magnetic resonance angiography with specific post-processing of the images has established itself as a reliable method for mapping tiny perforator vessels. Multiple donor sites can be imaged in a single setting without concern for ionising radiation exposure. This provides anatomical information of more reconstruction donor site options, so that a surgeon can design a flap of tissue centralised around the best perforator, as well as a back-up perforator, and even a back-up flap option located on a different region of the body. This information is especially helpful in patients with a history of scar tissue from previous surgeries, where the primary choice perforator is found to be damaged or unsuitable intraoperatively. In addition, chest magnetic resonance angiography evaluates recipient site blood vessel suitability including vessel diameters, course, and branching patterns. In this article we provide a broad overview of various skin flaps, clinical indications, advantages and disadvantages of each of these flaps, basic imaging technique, along with advanced sequences for visualising tiny arteries in the groin and in the chest. Post-processing techniques, structure of the report and how automation of the reporting system improves workflow is described. We also describe applications of magnetic resonance angiography in postoperative imaging.

Five recipient vessels for metachronous chest wall reconstruction: Case report and literature review

Selecting potential recipient vessel options for free flap anastomosis is an important consideration in microsurgical breast and chest wall reconstruction. In these settings, the most common comprise the internal mammary and thoracodorsal vessels, although alternative anastomotic sites have also been described. On occasion, consideration of these alternatives becomes a necessity. The use of five separate recipient vessels is highlighted in a unique case of recurrent locally advanced breast cancer requiring multiple complex reconstructions using free tissue transfer. A 56-year-old lady presented for delayed breast reconstruction one year after radical mastectomy for locally advanced lobular breast cancer. Despite wide resections, local chest-wall recurrence five times necessitated five microsurgical reconstructions, using separate recipient pedicles: internal mammary vessels, thoracodorsal vessels, serratus branch of thoracodorsal vessels, intercostal vessels and thoracoacromial vessels. All flaps survived completely, without donor or recipient complications. There has not been a subsequent recurrence at 6 months since last reconstruction. The purpose of this report is to present the first reported case of microsurgical chest wall reconstruction using five separate free flaps requiring anastomosis to multiple recipient vessels for anterior chest wall coverage, to present a literature-based and clinical review of the regional vascular anatomy of the anterior chest wall, and to present an operative approach algorithm. In such complex cases, this understanding can facilitate a streamlined approach to management. © 2014 Wiley Periodicals, Inc. Microsurgery 37:66-70, 2017.