Studies of injection ports of permanent expandable breast implants

Abstract

It has previously been questioned if the injection port of soft-tissue expanders is a source of leakage. However, several laboratory studies have concluded that the port is safe. A former quality assessment of our one-stage breast reconstructive procedures showed, that suspicion of leakage led to the removal of the injection port in 12% of the cases. With this level of inconsistency with previous laboratory studies, we found a need to conduct a separate study in order to confirm the true cause of leakage. Thirteen consecutively removed McGhan Style 150 injection ports were examined for leakage by increasing intraluminal pressure. Eight of the 13 ports had been removed because of discomfort due to the subcutaneous placement. Three of these eight ports showed substantial leakage (up to 14.55 ml/hour) at pressures attainable under normal in vivo circumstances. Five of the 13 ports had been removed due to clinical leakage. All five showed substantial leakage in the experimental setting (up to 19.65 ml/hour). Comparing the placement of the leaking puncture holes with the construction of the port, it seems that the leaking puncture holes are the result of peripheral perforations escaping the self-sealing material in the port, while still allowing injection of saline. The study shows clinical and experimental evidence of leakage from the McGhan Style 150 injection port, which is contrary to other similar laboratory studies. However, in those studies the needles were inserted at the apex of the port membrane, while our study shows that this is not in accordance with a clinical setting, where perforation may be all over the port. It is concluded that extreme care should be taken in the clinical setting only to perpendicularly perforate the apex of the injection port membrane. Peripheral perforation of the port may result in leakage of saline.