Tissue grafts and flaps are used to reconstruct wounds from trauma, chronic disease, tumor extirpation, burns, and infection. Despite careful surgical planning and execution, reconstructive failure can occur due to poor wound beds, radiation, random flap necrosis, vascular insufficiency, or ischemia-reperfusion (IR). Traumatic avulsions and amputated composite tissues-compromised tissue-may fail from crush injury and excessively large sizes. While never intended, these complications result in tissue loss, additional surgery, accrued costs, and negative psychosocial patient effects. Hyperbaric oxygen (HBO) has demonstrated utility in the salvage of compromised grafts/flaps. It can increase the likelihood and effective size of composite graft survival, improve skin graft outcomes, and enhance flap survival. Mechanisms underlying these beneficial effects include increased oxygenation, improved fibroblast function, neovascularization, and amelioration of IR injury. Common strategies for the compromised graft or flap include local wound care, surgical debridement, and repeated reconstruction. These modalities are associated with added costs, time, need for reoperation, morbidity, and psychosocial effects. Preservation of the amputated/avulsed tissues minimizes morbidity and maximizes the reconstructive outcome by salvaging the compromised tissue and obviating additional surgery. HBO is often overlooked as a potential tool that can limit these issues. Animal studies demonstrate a benefit of HBO in the treatment of compromised tissues. Clinical studies support these findings, but are limited to case reports and series. Further research is needed to provide multicenter prospective clinical studies and cost analyses comparing HBO to other adjunctive therapies in the treatment of compromised grafts/flaps.

Ischaemia-induced tissue injury has wide-ranging clinical implications including myocardial infarction, stroke, compartment syndrome, ischaemic renal failure and replantation and revascularization. However, the restoration of blood flow produces a 'second hit' phenomenon, the effect of which is greater than the initial ischaemic event and characterizes ischaemiareperfusion (IR) injury. Some examples of potential settings of IR injury include: following thrombolytic therapy for stroke, invasive cardiovascular procedures, solid organ transplantation, and major trauma resuscitation. Pathophysiological events of IR injury are the result of reactive oxygen species (ROS) production, microvascular vasoconstriction, and ultimately endothelial cell-neutrophil adhesion with subsequent neutrophil infiltration of the affected tissue. Initially thought to increase the amount of free radical oxygen in the system, hyperbaric oxygen (HBO) has demonstrated a protective effect on tissues by influencing the same mechanisms responsible for IR injury. Consequently, HBO has tremendous therapeutic value. We review the biochemical mechanisms of ischaemia-reperfusion injury and the effects of HBO following ischaemia-reperfusion.

Abstract Background Microsurgical free flaps require careful monitoring to detect early signs of compromise. At many hospitals, nursing staff provides the majority of postoperative monitoring of free flap patients and it lies within their responsibility to alert physicians of a failing free flap. The aim of this study is to identify knowledge gaps in the monitoring of microvascular free tissue transfer in both novice and experienced nurses and to provide appropriate education to address these gaps. Methods This was a pre- and postintervention study. An initial pilot survey was administered to identify knowledge deficiencies. A nursing educational session on free flap physiology and monitoring was then designed to address these deficiencies. An 18-question multiple choice quiz was administered before and after the educational session. Pre- and post-test scores were compared based on nursing experience. At 6 months, the participating nurses completed a survey rating their confidence with free flap patient care as a result of the educational session. Results A total of 72 nurses completed the in-service training course and quiz. The average quiz score increased from 61.9 to 89.3% after the in-service (p < 0.001). There was no correlation between precurriculum test scores and nursing experience as referenced by total number of years in the profession (r s = –0.038, p = 0.754). The follow-up survey showed that prior to the course 38% of respondents reported little or no confidence caring for free flap patients, decreasing to 6% after the course (p < 0.05). Conclusion Based on the results of this study, nursing knowledge of capillary refill, venous congestion, and basic microsurgical free flap physiology is inadequate. With implementation of a teaching in-service curriculum highlighting these key areas of deficiencies, nurses improved both their understanding and confidence levels, regardless of their level of experience.

Background: Fat grafting is a growing field within plastic surgery. Adipose-derived stem cells (ASCs) and stromal vascular fracture (SVF) may have a role in fat graft survival. Our group previously demonstrated a detrimental effect on ASC survival by the lidocaine used in tumescent solution. Sodium bicarbonate (SB) buffers the acidity of lidocaine. The purpose of this study was to determine whether SB buffering is a practical method to reduce ASC and SVF apoptosis and necrosis seen with common lidocaine-containing tumescent solution. Methods: Human patients undergoing bilateral liposuction for any indication were included in this study. An internally controlled, split-body design was utilized. Tumescent liposuction on one side of the body was conducted with tumescent containing lidocaine. On the opposite side, liposuction was conducted by adding SB to the tumescent. Tumescent solution and lipoaspirate pH were measured. Lipoaspirate from each side was processed for SVF isolation and ASC culture. The number of viable ASCs was counted and SVF apoptosis/necrosis was examined. Results: The pH of the SB-buffered tumescent was significantly higher than that of the standard tumescent, an effect also seen in the lipoaspirate. Adipose-derived stem cell survival in the SB-buffered lipoaspirate was approximately 53% higher. However, there was no significant difference in SVF apoptosis and necrosis between the groups. Conclusions: The acidic standard tumescent solution commonly used in liposuction diminishes ASC viability from lipoaspirates. Sodium bicarbonate buffering tumescent solution can enhance ASC viability, but does not affect SVF apoptosis and necrosis. We recommend buffering tumescent with SB to potentially improve fat graft take. Our findings advocate for further research investigating mechanisms and optimal harvest techniques that maximize SVF/ASC survival and the clinical effect on overall fat graft viability.