The anatomical evaluation of internal mammary vessels using sonography and 2-dimensional computed tomography in Asians

Duplex Imaging Assessment of the Internal Mammary Arteries in Women after Unilateral Mastectomy and Radiotherapy for Breast Cancer

BACKGROUND

The effects of incidental radiation exposure on internal mammary arteries remain unclear. The present study was designed to test the hypothesis by comparing diameter and blood flow of the irradiated and nonirradiated internal mammary arteries, using Duplex ultrasound imaging.

METHODS

The study was designed as a single-center, transversal, comparative study. The main outcomes were diameter and volumetric blood flow of the internal mammary arteries. The Wilcoxon rank-sum test was used to assess the differences between the irradiated and nonirradiated internal mammary arteries with regard to the diameter and volumetric blood flow.

RESULTS

The diameter (median [interquartile range]) of the irradiated internal mammary arteries (0.170 mm [0.160, 0.180]) was smaller than that of the contralateral nonirradiated ones (0.180 mm [0.170, 0.200], P < 0.0001) and that of the internal mammary arteries in the control group (0.180 mm [0.170, 0.190], P < 0.0001). Similarly, blood flow (median [interquartile range]) of the irradiated internal mammary arteries (52.4 ml/min [37.78, 65.57]) was smaller than that of the contralateral nonirradiated ones (62.7 ml/min [46.87, 84.17], P < 0.0001), as well as of the left (56.7 ml/min [46.88, 72.58], P = 0.02) and the right internal mammary arteries in the control group (61.0 ml/min [47.47, 74.52], P = 0 0.0009).

CONCLUSIONS

The data indicate that the irradiated internal mammary arteries in patients with a history of total mastectomy followed by radiotherapy for breast cancer had significantly smaller diameter and blood flow compared to the nonirradiated internal mammary arteries.

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.

Metastatic internal mammary lymph nodes or mimickers on parasternal ultrasonography: focusing on their distribution and depth

Background Ultrasonography (US) is an important tool to evaluate the status of internal mammary lymph node (IMN). US features of metastatic IMNs could help determine when biopsy should be performed. Purpose To compare US features of metastatic IMNs to those of benign entities. Material and Methods In women with suspected IMN metastasis on US, their intercostal space (ICS) abnormalities were classified into metastatic IMN, benign IMN, and lymph node (LN) mimickers. US features, distribution, and depth of abnormalities in one ICS and involved ICS level were analyzed. Results Among 66 ICS abnormalities in 53 women, 46 were metastatic IMNs, ten were benign IMNs, and ten were LN mimickers. For metastatic IMNs, the second ICS was the most commonly involved ICS (n = 22), followed by the first (n = 13), the third (n = 8), and the fourth (n = 3). ICS level distribution of metastatic IMNs was not significantly ( P = 0.5407) different from that of non-metastatic lesions. Metastatic IMNs were predominantly seen in the posterior layer of ICS, significantly ( P < 0.0001) different from LN mimickers. Both metastatic IMNs and non-metastatic lesions were evenly distributed over the upper, middle, and lower part (in craniocaudal direction) of one ICS. Conclusion Metastatic IMNs are more likely to be found in the posterior layer of ICS. This can help distinguish them from LN mimickers. Any part (upper, middle, or lower) of one ICS in craniocaudal direction could be involved. The second ICS was the most commonly involved level.

Graft pathology at the time of harvest: impact on long-term survival

Objective

This study aims to present the graft pathology at the time of harvest and its impact on long-term survival.

Methods

The remnants of the bypass grafts from 66 consecutive patients with coronary artery disease receiving a coronary artery bypass grafting were investigated pathologically, and pertinent predictive risk factors and survival were analyzed.

Results

Medial degenerative changes with or without intimal proliferation were present in 36.8%, 37.8% and 35.6% of left internal mammary artery (IMA), radial artery and saphenous vein grafts. There were 2 (3.0%) hospital deaths and 9 (14.1%) late deaths. Multinomial logistic regression revealed left IMA pathological changes, dyslipidemia, history of percutaneous transluminal coronary angioplasty/stent deployment and Y-graft were significant predictive risk factors negatively influencing the patients’ long-term survival. Kaplan-Meier survival analysis revealed that the long-term survival of patients with left IMA pathological changes were significantly reduced compared with those without (74.1% vs. 91.4%, P=0.002); whereas no differences were noted in long-term survivals between patients with and without pathological changes of the radial arterial or saphenous vein grafts.

Conclusion

Pathological changes may be seen in the bypass graft at the time of harvest. The subtle ultrastructural modifications and the expressions of vascular tone regulators might be responsible for late graft patency. The pathological changes of the left IMA at the time of harvest rather than those of the radial artery or saphenous vein graft affect significantly longterm survival. Non-traumatic maneuver of left IMA harvest, well-controlled dyslipidemia and avoidance of using composite grafts can be helpful in maintaining the architecture of the grafts.

Use of the internal mammary vein for access outflow in a hemodialysis fistula

A patient with occlusion of multiple central veins from both dialysis and nondialysis catheters required permanent access for hemodialysis. Magnetic resonance imaging showed a patent left innominate vein. He underwent creation of a left axillary artery to internal mammary vein transposition fistula using the basilic vein from his right arm. The fistula has required one revision for outflow stenosis and one for aneurysmal degeneration. It continues to function well 3 years after placement. The internal mammary vein is an option for outflow when permanent hemodialysis access has failed in the presence of a patent innominate vein with occluded or severely stenotic ipsilateral subclavian and jugular veins.

Mapping of internal mammary vessels by multidetector computed tomography for parasternal transthoracic intervention guidance

OBJECTIVE

To measure the distances between the internal mammary arteries (IMAs) and the sternum for determining a route for parasternal transthoracic interventions.

METHODS

Coronal reconstructed multidetector computed tomography images of 202 patients were evaluated to measure the distances between the IMAs and sternum at 3 levels (manubrium, midsternal corpus, and distal sternal corpus). The arrangements (2 veins-single artery or single vein-single artery) were documented.

RESULTS

The most frequently encountered arrangement (42.1%) was a single vein and single artery on both sides. Mean distances on the right and left sides were 10.2 and 10.1 cm at the manubrium, 14.5 and 14.3 cm at the midsternal corpus, and 17.9 and 17.5 cm at distal sternal corpus, respectively.

CONCLUSION

To be aware of the courses of the IMAs at different sternal levels is important during attempts at transthoracic intervention via a parasternal approach.