Rib-preserving Approach to Efficient Internal Mammary Vessel Preparation

INTRODUCTION

The internal mammary artery and vein are the workhorse recipient vessels in microvascular breast reconstruction. This is due to their ease of accessibility after mastectomy and their favorable size match with the most common first choice flap donor vessels, the deep inferior epigastric perforators.¹ Expeditious, reproducible preparation of the internal mammary vessels is important to ensure operative efficiency, and educational videos highlighting techniques to achieve this are valuable. These videos are particularly useful to surgical trainees, who are commonly tasked with performing this critical step of the reconstructive procedure. Haddock and Teotia² have described their systematic 5-step approach to the exposure of the internal mammary vessels, including removal of a piece of costal cartilage. This is a common technique but can result in pain and contour deformity of the chest wall.³ We present a 3-step technique for internal mammary vessel dissection that does not involve removal of costal cartilage, while providing sufficient space for microsurgical anastomosis. Although no patient-identifiable information is present in the video, the patient gave explicit consent for it to be used and disseminated in this format.

STEP 1: EXPOSURE

After the mastectomy has been completed, hooks are used to retract the skin. (See Video [online], which displays rib-preserving chest vessel preparation.) The hooks should be placed in the muscular fascia, and the skin edge protected with a damp swap, to avoid traction necrosis of the skin during the vessel preparation and microsurgical anastomosis. The intercostal space for the anastomosis is then chosen. This is usually the second, but the third can also be used, as demonstrated in the video. Monopolar diathermy is used in a rocking motion to detach a small portion of the sternal insertion of the pectoralis major in line with the chosen intercostal space. This is retracted laterally to expose the intercostal muscles.

Video 1. A video demonstrating the preparation of the internal mammary vessels for use in microvascular anastomosis, without removing rib cartilage.

Download video file ^{(115.7MB, mp4)}

STEP 2: MUSCULAR DISSECTION

A cuff of the intercostal muscles in the chosen interspace is next excised to expose the internal mammary vessels. Dissection of the intercostal muscles off their superior and inferior costo-cartilaginous insertions starts at a point approximately 2 cm medial to the costochondral junctions of the ribs above and below the interspace. Our experience is that, lateral to this, the fibrofatty layer that lies below the intercostal muscles is less dense and less constant, making pleural injury more likely with a more lateral dissection. The dissection proceeds from lateral to medial in this fibrofatty layer until the muscular cuff can be excised at the sternal insertion.

STEP 3: VESSEL DISSECTION AND PREPARATION FOR ANASTOMOSIS

The vessel dissection proceeds using bipolar diathermy on a low setting and forceps. Gentle, indirect vessel handling is ideal. Lymph nodes can be encountered adjacent to the vessels, and these are most commonly excised. Large side branches of both the internal mammary artery and vein are clipped and divided as they are encountered. During the dissection, the vessels are cooled intermittently with heparinized saline. In the video, the third interspace is used, demonstrating the 2 tributaries of the internal mammary vein at this level. The dissection is continued to expose a small portion of the artery and veins below the costal cartilages superiorly and inferiorly. This allows additional space for the application of the vascular clamps, leaving the full interspace available to perform the microanastomosis. If more exposure is needed, the costal cartilage can be removed, though this is seldom necessary.

CONCLUSIONS

This article described a systematic 3-step technique for performing internal mammary vessel preparation without removal of costal cartilage.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.