The effect of hyperbaric oxygen on compromised grafts and flaps.

The use of grafts and flaps serves as an integral tool in the armamentarium of the reconstructive surgeon. Proper planning and surgical judgment are critical in the ultimate success of these procedures. However, there are situations when grafts and/or flaps can become compromised and require urgent intervention for salvage. These instances can include irradiated or otherwise hypoxic wound beds, excessively large harvested grafts, random flap ischemia, venous or arterial insufficiency, and ischemia-reperfusion injury. Alternatively, compromised grafts and flaps can be inadvertently created secondary to trauma. It is in these types of cases, hyperbaric oxygen (HBO2) therapy can serve as a useful adjunct in the salvage of compromised flaps and grafts. This review outlines the extensive basic science and clinical evidence available in support of the use of HBO2 therapy for compromised grafts and flaps. The literature demonstrates the benefit of adjunctive HBO2 therapy for multiple types of grafts and flaps with various etiologies of compromise. HBO2 therapy can enhance graft and flap survival by several methods including decreasing the hypoxic insult, enhancing fibroblast function and collagen synthesis, stimulating angiogenesis and inhibiting ischemia-reperfusion injury. The expedient initiation of hyperbaric oxygen therapy as soon as flap or graft compromise is identified maximizes tissue viability and ultimately graft/flap salvage.

Nursing Monitoring of Microsurgical Free Flaps: Identifying and Addressing Knowledge Gaps.

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.

Ahead of the Curve: Tracking Progress in Novice Microsurgeons.

BACKGROUND: The purpose of this study was to evaluate learning curves for an existing microsurgical training model. We compared efficiency and amount of training needed to achieve proficiency between novice microsurgeons without operative experience versus those who had completed a surgical internship. METHODS: Ten novice microsurgeons anastomosed a silastic tube model. Time to perform each anastomosis, luminal diameter, and number of errors were recorded. RESULTS: First year residents improved up to a brief plateau at 10 repetitions, followed by continued improvement. Second year residents improved up to a plateau at 10 repetitions with no further improvement thereafter. There was no significant difference in luminal area or errors between groups. CONCLUSION: Residents with no operative experience can benefit from early exposure to microsurgical training. These interns continue to improve with additional repetitions while second year residents achieve proficiency with fewer repetitions.

Reducing Complications and Expanding Use of Robotic Rectus Abdominis Muscle Harvest for Pelvic Reconstruction.

SUMMARY: The rectus abdominis flap has long been a workhorse in perineal reconstruction. Although traditionally approached though an external incision, the morbid nature of the incision and subsequent violation of the anterior rectus sheath has encouraged innovation of minimally invasive approaches for harvest. In this study, we present our experience, evolution, and comparative outcomes of robotic rectus abdominis muscle harvest. A retrospective review of perineal reconstruction was performed for a 6-year period (2014 to 2019). Robotic rectus abdominis muscle flaps were compared to nonrobotic techniques performed during this time. Descriptive statistics and complication profiles were computed. The details of our surgical technique are also described. Thirty-six patients underwent perineal reconstruction. Sixteen were performed using the robotic rectus abdominis muscle and 20 with traditional repairs (12 vertical rectus abdominis myocutaneous flaps and eight gracilis flaps). Demographic profiles were similar between cohorts, including age, body mass index, smoking, diabetes, neoadjuvant radiation therapy, and need for vaginal wall repair. Six robotic patients underwent abdominal wall reinforcement with biological mesh. Length of stay, surgical times, and incidence of major complications were similar between cohorts with a trend toward increased minor complications in traditional reconstructions (55 percent versus 31 percent; p = 0.15). Robotic rectus abdominis muscle harvest is a powerful tool that continues to evolve the potential to mitigate common morbidities and complications of traditional repair and further enhance cosmetic outcomes. This study suggests that greater flexibility for reconstruction can be afforded with harvest of the posterior rectus sheath and complications avoided with prophylactic mesh reinforcement. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Hyperbaric Oxygen Inhibits Reperfusion-Induced Neutrophil Polarization and Adhesion Via Plasmin-Mediated VEGF Release.

BACKGROUND: Ischemia-reperfusion (IR) injury is seen in many settings such as free flap salvage and limb replantation/revascularization. The consequences-partial/total flap loss, functional muscle loss, or amputation-can be devastating. Of the treatment options available for IR injury, hyperbaric oxygen (HBO) is the most beneficial. HBO inhibits neutrophil-endothelial adhesion through interference of CD18 neutrophil polarization in IR, a process mediated by nitric oxide. The purposes of this study were to examine the involvement of vascular endothelial growth factor (VEGF) in the beneficial HBO effect on CD18 polarization and neutrophil adhesion and investigate the effect of plasmin on VEGF expression in skeletal muscle following IR injury. METHODS: A rat gracilis muscle model of IR injury was used to evaluate the effect of VEGF in IR, with and without HBO, on neutrophil CD18 polarization and adhesion in vivo and ex vivo. Furthermore, we investigated the effects that plasmin has on VEGF expression in gracilis muscle and pulmonary tissue by blocking its activation with alpha-2-antiplasmin. RESULTS: HBO treatment following IR injury significantly decreased neutrophil polarization and adhesion ex vivo compared with the IR group. Anti-VEGF reversed the beneficial HBO effect after IR with polarization and adhesion. In vivo adhesion was also increased by anti-VEGF. HBO treatment of IR significantly increased the VEGF protein in both gracilis and pulmonary vasculature. Alpha-2-antiplasmin significantly reversed the HBO-induced increase of VEGF in gracilis muscle. CONCLUSIONS: These results suggest that HBO inhibits CD18 polarization and neutrophil adhesion in IR injury through a VEGF-mediated pathway involving the extracellular matrix plasminogen system.