Nanofiber-hydrogel composite-mediated angiogenesis for soft tissue reconstruction.

Soft tissue losses from tumor removal, trauma, aging, and congenital malformation affect millions of people each year. Existing options for soft tissue restoration have several drawbacks: Surgical options such as the use of autologous tissue flaps lead to donor site defects, prosthetic implants are prone to foreign body response leading to fibrosis, and fat grafting and dermal fillers are limited to small-volume defects and only provide transient volume restoration. In addition, large-volume fat grafting and other tissue-engineering attempts are hampered by poor vascular ingrowth. Currently, there are no off-the-shelf materials that can fill the volume lost in soft tissue defects while promoting early angiogenesis. Here, we report a nanofiber-hydrogel composite that addresses these issues. By incorporating interfacial bonding between electrospun poly(ε-caprolactone) fibers and a hyaluronic acid hydrogel network, we generated a composite that mimics the microarchitecture and mechanical properties of soft tissue extracellular matrix. Upon subcutaneous injection in a rat model, this composite permitted infiltration of host macrophages and conditioned them into the pro-regenerative phenotype. By secreting pro-angiogenic cytokines and growth factors, these polarized macrophages enabled gradual remodeling and replacement of the composite with vascularized soft tissue. Such host cell infiltration and angiogenesis were also observed in a rabbit model for repairing a soft tissue defect filled with the composite. This injectable nanofiber-hydrogel composite augments native tissue regenerative responses, thus enabling durable soft tissue restoration outcomes.

Increased Incidence of Symptomatic Venous Thromboembolism following Pedicled Lower Extremity Flap Harvest for Abdominal and Perineal Reconstruction in Patients Receiving Mechanical Prophylaxis and Chemoprophylaxis: A Case for Heightened Awareness.

BACKGROUND: Postsurgical venous thromboembolism remains a leading cause of hospital morbidity. Data to support venous thromboembolism prophylaxis guidelines in lower extremity flap surgery are lacking. The purpose of this study was to explore the effect of pedicled lower extremity flap harvest on venous thromboembolism development in the setting of abdominal or perineal reconstruction. METHODS: One hundred twenty-six patients undergoing unilateral lower extremity flap harvest for abdominal or perineal reconstruction were included. The contralateral leg served as an internal control. Sixty comorbidity-matched patients who underwent abdominal/perineal resection without flap reconstruction provided an external control. Bivariate analyses included chi-square and t tests; logistic regression adjusted for confounding variables on venous thromboembolism development. RESULTS: All patients underwent flap reconstruction for an oncologic defect of the abdomen or perineum, with 80 percent undergoing perineal reconstruction. Most patients underwent anterolateral thigh (41 percent) or gracilis flap (40 percent) harvest. Eleven patients developed deep venous thromboses in one or more legs (9 percent): 10 of 11 (90.9 percent) in the donor extremity and five (45.5 percent) contralaterally (p = 0.022). Patients who underwent flap harvest had a 10-fold higher odds of venous thromboembolism formation when compared to comorbidity-matched controls without flap reconstruction (OR, 10.64; 95 percent CI, 1.11 to 102.34; p = 0.041). CONCLUSIONS: The rate of venous thromboembolism is higher than previously appreciated for reconstructive procedures of the abdomen and/or perineum that use pedicled lower extremity flaps-particularly in the operative extremity. Additional research can clarify the role for further prophylaxis or screening. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Prepectoral Versus Subpectoral Tissue Expander Placement: A Clinical and Quality of Life Outcomes Study.

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.

Systematic Review of the Surgical Treatment of Extremity Lymphedema.

Background Although conservative management of lymphedema remains the first-line approach, surgery is effective in select patients. The purpose of this study was to review the literature and develop a treatment algorithm based on the highest quality lymphedema research. Methods A systematic literature review was performed to examine the surgical treatments for lymphedema. Studies were categorized into five groups describing excision, liposuction, lymphovenous anastomosis (LVA), vascularized lymph node transfer (VLNT), and combined/multiple approaches. Studies were scored for methodological quality using the methodological index for nonrandomized studies (MINORS) scoring system. Results A total of 69 articles met inclusion criteria and were assigned MINORS scores with a maximum score of 16 or 24 for noncomparative or comparative studies, respectively. The average MINORS scores using noncomparative criteria were 12.1 for excision, 13.2 for liposuction, 12.6 for LVA, 13.1 for VLNT, and 13.5 for combined/multiple approaches. Loss to follow-up was the most common cause of low scores. Thirty-nine studies scoring > 12/16 or > 19/24 were considered high quality. In studies measuring excess volume reduction, the mean reduction was 96.6% (95% confidence interval [CI]: 86.2-107%) for liposuction, 33.1% (95% CI: 14.4-51.9%) for LVA, and 26.4% (95% CI: - 7.98 to 60.8%) for VLNT. Included excision articles did not report excess volume reduction. Conclusion Although the overall quality of lymphedema literature is fair, the MINORS scoring system is an effective method to isolate high-quality studies. These studies were used to develop an evidence-based algorithm to guide clinical practice. Further studies with a particular focus on patient follow-up will improve the validity of lymphedema surgery research.

Intensive Care Unit Monitoring After Pharyngeal Flap Surgery: Is It Necessary?

PURPOSE: To assess the incidence of perioperative complications and the utility of intensive care monitoring in patients undergoing posterior pharyngeal flap surgery for velopharyngeal dysfunction (VPD). MATERIALS AND METHODS: This study was a retrospective evaluation of patients who underwent posterior pharyngeal flap surgery for treatment of VPD and an assessment of the incidence of perioperative complications. Descriptive statistics were computed. RESULTS: Over an 18-year period, 145 patients underwent pharyngeal flap surgery for VPD; 133 (91.7%) had complete data and were included as subjects. Mean patient age was 9.4 ± 7.4 years; 50.4% were female. One hundred twenty-six patients (94.7%) had a history of cleft palate. Thirty-four patients (25.5%) had asthma or obstructive sleep apnea. Eighty-three patients (62.4%) were admitted to the intensive care unit (ICU) for postoperative monitoring. The average length of hospital stay was 1.9 ± 0.9 days (range, 1 to 5 days). There were no incidents of serious postoperative complications, including death, bleeding, flap dehiscence or loss, or airway compromise requiring reintubation. Two patients (1.5%) had perioperative complications related to respiratory issues, one of whom required readmission to the ICU (0.8%). There were no differences in complications between those who were routinely admitted to the ICU and those who went directly to the floor (P = 1.00). There was no association between respiratory comorbidities and complications (P = .06). CONCLUSION: The perioperative complication rate for posterior pharyngeal flap surgery is low (<2%). Routine ICU admission for monitoring is not necessary.