Contralateral Direction Of The Internal Mammary Perforator FLAP

Introduction

In 1917, Aymard described a tubed flap from the anterior thorax for nasal reconstruction. This was similar to Joseph’s “pectoral Flap” or to Bakamjian’s subsequently described deltopectoral flap with the exception that Aymard based it on the contralateral internal mammary perforators and not the ipsilateral ones as described by Joseph and Bakamjian. This would fly in the face of current vascular understanding based on publications that suggest that perfusion does not cross the midline. The purpose of this paper is to present the results of an anatomical investigation of the vascular anatomy of the anterior thoracic wall integument, our experience with 5 clinical cases using the pectoral and deltopectoral flaps raised on the contralateral perforators and to comment on flap vascularization.

Material and methods

20 fresh cadavers were injected with colored latex through the ascending aorta. The specimens were fixed with 10% acetic acid, washed copiously with water and fixed with formalin 5%. The cutaneous branches of the internal mammary artery were dissected under 4X magnification. The adventitia was stripped to expose the latex cast of the vessels for easy observation. The subcutaneous distribution of the cutaneous branches was dissected under the microscope for better magnification.

Five specimens were injected with ink through the internal mammary artery. The stained skin area was observed

Five clinical cases were treated using deltopectoral flaps raised on the contralateral internal mammary perforators for different clinical indications and evaluated according flap survival and donor site morbidity. The absolute length of the flaps varied from 22 to 30cm.

Results.

The latex injections revealed a radial pattern of outflow from the internal mammary perforators with evidence of these vessels joining with similar ones from the contralateral side. This pattern was confirmed by the circular pattern of ink staining when these perforators were injected.

All clinical flaps survived.

Conclusion.

This study would indicate that current anatomic knowledge may be inaccurate in terms of perfusion across the midline, at least in the anterior thorax. The radial pattern of blood flow supports Neligan’s observation that the internal mammary perforator flap may be raised on several different axes. The clinical outcome  of the five flaps presented would lend support to these observations.