No abstract

Background:Traditionally, tissue expanders (TEs) for breast reconstruction have been placed beneath the pectoralis major muscle with or without acellular dermal matrix. More recently, full acellular dermal matrix coverage has been described for prepectoral TE placement. Our study aims to explore differences in clinical and quality-of-life (QOL) outcomes for prepectoral versus subpectoral TE breast reconstruction.Methods:We identified patients who underwent postmastectomy breast reconstruction with prepectoral or subpectoral TE placement between 2011 and 2015 and completed QOL surveys. Primary outcomes were postoperative pain and QOL scores. Secondary outcomes were clinical outcomes. We used Wilcoxon rank-sum test, chi-square test, and linear regression to compare outcomes. Postoperative follow-up for each patient was at least 60 days, except that of pain scores, which were at least 30 days. Mean age was 49 ± 10 years.Results:Twenty-six prepectoral TE patients and 109 subpectoral TE patients met inclusion criteria. Pain scores were significantly lower at 12 hours, 1 day, 7 days, and 30 days postoperatively for the prepectoral group, compared with the subpectoral group, even after adjusting for confounding variables [PO12H: Sub-Pectoral (SP) median (interquartile range), 7 (5–8), Pre-Pectoral (PP), 5 (2.5–7.5), P value = 0.004; PO1D: SP, 5 (4–6), PP 3 (2–4), P value = < 0.001; PO7D: SP, 2 (0–4), PP, 0 (0–2), P value = 0.004; PO30D: SP, 0 (0–2), PP, 0 (0–0), P value = 0.039)]. Breast-Q scores were not significantly different between study groups. RAND-36 Physical Health scores were lower among prepectoral TE patients.Conclusions:Prepectoral TE breast reconstruction presents an opportunity to improve upon current reconstructive methods and does result in significantly lower pain scores. The associated risks have yet to be fully described and are important considerations, as these prepectoral patients had lower physical health outcome scores.

Axon regeneration in the central nervous system is severely hampered, limiting functional recovery. This is in part because of endogenous axon regeneration inhibitors that accumulate at the injury site. Therapeutic targeting of these inhibitors and their receptors may facilitate axon outgrowth and enhance recovery. A rat model of spinal cord contusion injury was used to test the effects of two bacterial enzyme therapies that target independent axon regeneration inhibitors, sialidase (Vibrio cholerae) and chondroitinase ABC (ChABC, Proteus vulgaris). The two enzymes, individually and in combination, were infused for 2 weeks via implanted osmotic pumps to the site of a moderate thoracic spinal cord contusion injury. Sialidase was completely stable, whereas ChABC retained > 30% of its activity in vivo over the 2 week infusion period. Immunohistochemistry revealed that infused sialidase acted robustly throughout the spinal cord gray and white matter, whereas ChABC activity was more intense superficially. Sialidase treatment alone resulted in improved behavioral and anatomical outcomes. Rats treated exclusively with sialidase showed significantly increased hindlimb motor function, evidenced by higher Basso Beattie and Bresnahan (BBB) and BBB subscores, and fewer stepping errors on a horizontal ladder. Sialidase-treated rats also had increased serotonergic axons caudal to the injury. ChABC treatment, in contrast, did not enhance functional recovery or alter axon numbers after moderate spinal cord contusion injury, and dampened the response of sialidase in the dual enzyme treatment group. We conclude that sialidase infusion enhanced recovery from spinal cord contusion injury, and that combining sialidase with ChABC failed to improve outcomes.