Association between Bioimpedance Spectroscopy and Magnetic Resonance Lymphangiography in the Diagnosis and Assessment of Lymphedema.

BACKGROUND: This study assesses associations between bioimpedance spectroscopy (BIS) and magnetic resonance lymphangiography (MRL) in the staging and assessment of lymphedema. METHODS: Adults who received MRL and BIS between 2020 and 2022 were included. We collected fluid, fat, and lymphedema severity ratings, and measured fluid stripe thickness, subcutaneous fat width, and lymphatic diameter on MRL. BIS lymphedema index (L-Dex) scores were collected from patient charts. We assessed sensitivity and specificity of L-Dex scores to detect MRL-identified lymphedema, and examined associations between L-Dex scores and MRL imaging measures. RESULTS: Forty-eight limbs across 40 patients were included. L-Dex scores had 72.5% sensitivity and 87.5% specificity for detecting MRL-defined lymphedema, with a 96.7% estimated positive predictive value and 38.9% negative predictive value. L-Dex scores were associated with MRL fluid and fat content scores (p ≤ 0.05), and lymphedema severity (p = 0.01), with better discrimination between fluid than fat content levels on pairwise analysis, and poor discrimination between adjacent severity levels. L-Dex scores were correlated with distal and proximal limb fluid stripe thickness (distal: rho = 0.57, p < 0.01; proximal: rho = 0.58, p < 0.01), partially correlated with distal subcutaneous fat thickness when accounting for body mass index (rho = 0.34, p = 0.02), and were not correlated with lymphatic diameter (p = 0.25). CONCLUSION: L-Dex scores have high sensitivity, specificity, and positive predictive value for the identification of MRL-detected lymphedema. L-Dex has difficulty distinguishing between adjacent severity levels of lymphedema and a high false negative rate, explained in part by reduced discrimination between levels of fat accumulation.

Technical Variables in Lower Extremity Free Flap Reconstruction.

BACKGROUND: Lower extremity free flap failure rates are higher than in other areas of the body. While prior studies assessed the effect of intraoperative technical variables, these generally investigated individual variables and did not examine relationships between the many individual technical decisions made during free tissue reconstruction. Our purpose was to investigate the effect of variation in intraoperative microsurgical techniques on flap outcomes in a diverse cohort of patients requiring lower extremity free flap coverage. METHODS: Consecutive patients undergoing free flap reconstruction of the lower extremity at two level 1 trauma centers from January 2002 to January 2020 were identified using Current Procedural Terminology codes, followed by a review of medical records. Information regarding demographics and comorbidities, indications, intraoperative technical details, and complications was collected. Outcomes of interest included an unplanned return to the operating room, arterial thrombosis, venous thrombosis, partial flap failure, and total flap failure. Bivariate analysis was performed. RESULTS: In total, 410 patients underwent 420 free tissue transfers. The median follow-up time was 17 months (interquartile ranges: 8.0-37). Total flap failure occurred in 4.9% (n = 20), partial flap failure in 5.9% (n = 24), and unplanned reoperation in 9.0% (n = 37), with arterial thrombosis in 3.2% (n = 13) and venous thrombosis in 5.4% (n = 22). Overall complications were significantly associated with recipient artery choice, with arteries other than PT and AT/DP having a higher rate (p = 0.033), and with arterial revisions (p = 0.010). Total flap failure was also associated with revision of the arterial anastomosis (p = 0.035), and partial flap failure was associated with recipient artery choice (p = 0.032). CONCLUSION: Many interoperative options and techniques are available when performing microvascular lower extremity reconstruction that leads to equally high success rates. However, the use of arterial inflow outside of the posterior tibial and anterior tibial arteries leads to a higher overall complication rate and partial flap failure rate. Intraoperative revision of the arterial anastomosis portends poorly for ultimate flap survival.

Investigating Weekend Effect in the Management of Upper and Lower Extremity Degloving Injuries.

Background: Weekend presentation has been associated with adverse outcomes in emergent conditions, including stroke, myocardial infarction, and critical limb ischemia. We examine whether a weekend effect exists in the management of and outcomes after extremity degloving injuries. Methods: The cohort included adults presenting with open extremity degloving injuries to a tertiary level one trauma center between June 2018 and May 2022. We collected demographics, comorbidities, injury information, interventions, and complications. Propensity score weighting was used to minimize confounding differences between those presenting on weekends (Sat-Sun) versus weekdays (Mon-Fri). Weighted regressions were used to examine differences in interventions by day of presentation. Multivariable weighted regressions accounting for differences in interventions received were used to examine whether weekend presentation was associated with amputation risk, complications, or functional deficits. Results: Ninety-five patients with 100 open extremity degloving injuries were included. In total, 39% of injuries were weekend-presenting. There was a higher rate of noninsulin-dependent diabetes among patients presenting on weekends (P = 0.03). Weekend-presenting injuries had higher median Injury Severity Scores (P = 0.04). Propensity-weighted regression analysis revealed differences in interventions received on weekends, including lower rates of pedicled and free flaps and bone graft, and increased rates of negative-pressure wound therapy (P ≤ 0.02). Multivariable regression analysis revealed weekend presentation was a significant independent risk factor for amputation of the affected extremity [odds ratio 2.27, 95% CI (1.01-5.33), P = 0.05]. Conclusion: Weekend presentation may impact interventions received and amputation risk in patients presenting with open extremity degloving injuries.

Point-of-Care Tissue Oxygenation Assessment with SnapshotNIR for Alloplastic and Autologous Breast Reconstruction.

In breast reconstruction, mastectomy and free flaps are susceptible to vascular compromise and tissue necrosis. The SnapshotNIR device (Kent Imaging, Calgary, AB, Canada) utilizes near-infrared spectroscopy to measure tissue oxygen saturation (StO2) and hemoglobin concentration. Here, we report on the use of this device for StO2 monitoring among patients receiving alloplastic or autologous breast reconstruction. Methods: Patients receiving immediate alloplastic reconstruction after mastectomy or autologous reconstruction were enrolled. Preoperative, intraoperative, and postoperative images were taken of the flaps. StO2 and hemoglobin were measured at the following locations: superior and inferior breast, free flap skin paddle (when applicable), and un-operated control skin. Linear mixed effects model for repeated measurements was used to model measurements to estimate the area effect difference across time, time effect difference across area, and pairwise comparisons between two areas at each time point. Results: Thirty-two breasts underwent alloplastic reconstruction; 38 breasts underwent autologous reconstruction. No enrollees developed skin necrosis. StO2 was highest after mastectomy and closure in alloplastic reconstructions. StO2 was observed to decline at follow-up in autologous reconstructions. Mean preoperative StO2 was highest in breasts that had previously undergone mastectomy and alloplastic reconstruction. Conclusions: The SnapshotNIR device detected normal spatial and temporal differences in tissue oxygenation over the operative course of alloplastic and autologous breast reconstruction. A multi-institutional, prospective clinical trial is needed to determine the sensitivity and specificity of this device for detecting skin flap necrosis.

Secondary Surgery after Lower Extremity Free Flap Reconstruction.

BACKGROUND: Microsurgical free tissue transfer may be the only reconstructive option for lower extremity limb salvage. However, the functional and aesthetic results following free tissue transfer after initial salvage may be suboptimal, thus requiring secondary operations to facilitate definitive wound healing and/or refinement. METHODS: A multi-institutional retrospective cohort study was performed including patients who underwent lower extremity free tissue transfer from January of 2002 to December of 2020. The authors' primary outcome variable was the presence of secondary surgery after free tissue transfer for lower extremity reconstruction. Independent variables (eg, wound cause, flap, donor type, recipient, comorbidities) were collected. Secondary surgery was categorized as (1) procedures for definitive wound closure and (2) refinement procedures. Multivariable logistic regression was performed to determine which variables were independently associated with the outcome. RESULTS: A total of 420 free tissue transfers for lower extremity reconstruction were identified. Secondary surgery was performed in over half (57%) of the patients. Presence of diabetes (OR, 2.0; P = 0.01; 95% CI, 1.2 to 3.5) and use of a latissimus dorsi donor (OR, 2.4; P = 0.037; 95% CI, 1.1 to 5.4) were predictors of wound closure procedures. Fasciocutaneous (OR, 3.6; P < 0.001; 95% CI, 1.8 to 7.2) and myocutaneous (OR, 3.0; P = 0.005; 95% CI, 1.5 to 9.9) flaps were predictors of refinement procedures when compared with muscle-only flaps with skin grafts. CONCLUSIONS: The majority of lower extremity free tissue reconstructions required secondary procedures to provide definitive wound closure and/or refinement. Overall, this study provides predictors of secondary surgery that will help formulate patients' expectations of lower extremity limb salvage. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Compound Effect of Hypoalbuminemia and Obesity on Complications after Autologous Breast Reconstruction.

BACKGROUND: Obesity is among the risk factors identified that impair postoperative wound healing. Recently, malnutrition and sarcopenia have also been found to correlate with poor surgical outcomes; however, the effect of malnutrition in the setting of obesity is understudied, particularly in reconstructive surgery. The authors examine the American College of Surgeons National Surgery Quality Improvement Program database to determine the impact of obesity plus hypoalbuminemia on complications after autologous breast reconstruction. METHODS: Autologous breast reconstruction procedures (pedicled and free flaps) were collected from the 2009 to 2019 National Surgery Quality Improvement Program databases by CPT codes ( n = 23,690). Patients without height, weight, or preoperative serum albumin data ( n = 12,825) were excluded. Demographics and postoperative outcomes were compared in patients with obesity (body mass index >30 kg/m 2 ) and malnutrition (albumin <3.5 g/dL). Propensity score-matched cohorts with and without malnutrition were also compared. RESULTS: A total of 10,865 procedures were included in analysis; 4565 involved patients with obesity (42%). Obesity was associated with increased length of stay, reoperations, wound complications, and medical complications (all P < 0.001). Among patients with obesity, 198 had malnutrition (4.3%). The combination of obesity and malnutrition was associated with a higher rate of wound complications (16%) over obesity alone (9.2%) or malnutrition alone (9.2%, both P < 0.05). This difference is recapitulated in propensity score-matched analysis. CONCLUSION: Hypoalbuminemia, a marker of malnutrition, is underappreciated in obese patients and is associated with worse surgical outcomes after autologous breast reconstruction compared with obesity alone. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

The Association between Breast Cancer Related Lymphedema and Area Deprivation Index.

BACKGROUND: Lymphedema affects up to 34% of patients after breast cancer treatment but remains underdiagnosed and undertreated. Here, we use area deprivation index (ADI), a measure of neighborhood socioeconomic disadvantage, to determine how socioeconomic status may affect risk for and diagnosis of breast cancer-related lymphedema. METHODS: Records of patients who underwent surgical treatment of breast cancer between 2017-2020 were examined. Patients' nine-digit ZIP codes were utilized to determine their deprivation level as a national ADI percentile, and those fitting into the most and least deprived quartiles were compared with evaluate lymphedema risk factors and incidence. RESULTS: A total of 1,333 breast cancer patients were included, 812 (61%) of whom resided within the most disadvantaged ADI quartile nationally, and 521 within the least disadvantaged quartile. The most deprived group had higher rates of diabetes, obesity, and regional breast cancer, and received more extensive surgeries (7.5% modified radical mastectomy vs 1.9%, p < 0.001) and chemotherapy compared with the least disadvantaged quartile. The most disadvantaged cohort were more often at extreme risk of lymphedema utilizing the Risk Assessment Tool Evaluating Lymphedema Risk (9.1% versus 2.5%, p < 0.001); however, the incidence of lymphedema diagnoses was not significantly higher (13% vs 12%, p > 0.9). Logistic regression showed that the most deprived ADI quartile had 44% lower odds of a lymphedema diagnosis in comparison to the least deprived quartile. CONCLUSION: Residing in more socioeconomically disadvantaged neighborhoods is associated with lower odds of a lymphedema diagnosis, despite higher rates of risk factors for lymphedema, suggesting significant underdiagnosis in this population.

The impact of the COVID-19 pandemic on alloplastic breast reconstruction: An analysis of national outcomes.

BACKGROUND: Immediate alloplastic breast reconstruction shifted to the outpatient setting during the COVID-19 pandemic to conserve inpatient hospital beds while providing timely oncologic care. We examine the National Surgical Quality Improvement Program (NSQIP) database for trends in and safety of outpatient breast reconstruction during the pandemic. METHODS: NSQIP data were filtered for immediate alloplastic breast reconstructions between April and December of 2019 (before-COVID) and 2020 (during-COVID); the proportion of outpatient procedures was compared. Thirty-day complications were compared for noninferiority between propensity-matched outpatients and inpatients utilizing a 1% risk difference margin. RESULTS: During COVID, immediate alloplastic breast reconstruction cases decreased (4083 vs. 4677) and were more frequently outpatient (31% vs. 10%, p < 0.001). Outpatients had lower rates of smoking (6.8% vs. 8.4%, p = 0.03) and obesity (26% vs. 33%, p < 0.001). Surgical complication rates of outpatient procedures were noninferior to propensity-matched inpatients (5.0% vs. 5.5%, p = 0.03 noninferiority). Reoperation rates were lower in propensity-matched outpatients (5.2% vs. 8.0%, p = 0.003). CONCLUSION: Immediate alloplastic breast reconstruction shifted towards outpatient procedures during the COVID-19 pandemic with noninferior complication rates. Therefore, a paradigm shift towards outpatient reconstruction for certain patients may be safe. However, decreased reoperations in outpatients may represent undiagnosed complications and warrant further investigation.

National Outcomes of Prophylactic Lymphovenous Bypass during Axillary Lymph Node Dissection.

BACKGROUND: Breast cancer treatment, including axillary lymph node excision, radiation, and chemotherapy, can cause upper extremity lymphedema, increasing morbidity and health care costs. Institutions increasingly perform prophylactic lymphovenous bypass (LVB) at the time of axillary lymph node dissection (ALND) to reduce the risk of lymphedema but reports of complications are lacking. We examine records from the American College of Surgeons (ACS) National Surgery Quality Improvement Program (NSQIP) database to examine the safety of these procedures. METHODS: Procedures involving ALND from 2013 to 2019 were extracted from the NSQIP database. Patients who simultaneously underwent procedures with the Current Procedural Terminology (CPT) codes 38999 (other procedures of the lymphatic system), 35201 (repair of blood vessel), or 38308 (lymphangiotomy) formed the prophylactic LVB group. Patients in the LVB and non-LVB groups were compared for differences in demographics and 30-day postoperative complications including unplanned reoperation, deep vein thrombosis (DVT), wound dehiscence, and surgical site infection. Subgroup analysis was performed, controlling for extent of breast surgery and reconstruction. Multivariate logistic regression was performed to identify predictors of reoperation. RESULTS: The ALND without LVB group contained 45,057 patients, and the ALND with LVB group contained 255 (0.6%). Overall, the LVB group was associated with increased operative time (288 vs. 147 minutes, p < 0.001) and length of stay (1.7 vs. 1.3 days, p < 0.001). In patients with concurrent mastectomy without immediate reconstruction, the LVB group had a higher rate of DVTs (3.0 vs. 0.2%, p = 0.009). Reoperation, wound infection, and dehiscence rates did not differ across subgroups. Multivariate logistic regression showed that LVB was not a predictor of reoperations. CONCLUSION: Prophylactic LVB at time of ALND is a generally safe and well-tolerated procedure and is not associated with increased reoperations or wound complications. Although only four patients in the LVB group had DVTs, this was a significantly higher rate than in the non-LVB group and warrants further investigation.

Efficient and precise Ultra-QuickDASH scale measuring lymphedema impact developed using computerized adaptive testing.

PURPOSE: This study aimed to evaluate and improve the accuracy and efficiency of the QuickDASH for use in assessment of limb function in patients with upper extremity lymphedema using modern psychometric techniques. METHOD: We conducted confirmative factor analysis (CFA) and Mokken analysis to examine the assumption of unidimensionality for IRT model on data from 285 patients who completed the QuickDASH, and then fit the data to Samejima's graded response model (GRM) and assessed the assumption of local independence of items and calibrated the item responses for CAT simulation. RESULTS: Initial CFA and Mokken analyses demonstrated good scalability of items and unidimensionality. However, the local independence of items assumption was violated between items 9 (severity of pain) and 11 (sleeping difficulty due to pain) (Yen's Q3 = 0.46) and disordered thresholds were evident for item 5 (cutting food). After addressing these breaches of assumptions, the re-analyzed GRM with the remaining 10 items achieved an improved fit. Simulation of CAT administration demonstrated a high correlation between scores on the CAT and the QuickDash (r = 0.98). Items 2 (doing heavy chores) and 8 (limiting work or daily activities) were the most frequently used. The correlation among factor scores derived from the QuickDASH version with 11 items and the Ultra-QuickDASH version with items 2 and 8 was as high as 0.91. CONCLUSION: By administering just these two best performing QuickDash items we can obtain estimates that are very similar to those obtained from the full-length QuickDash without the need for CAT technology.

Measurement Properties of the Lymphedema Life Impact Scale.

Background: The updated Lymphedema Life Impact Scale (LLIS, version 2) has been widely used to evaluate the effect of lymphedema from the patient's perspective. We sought to assess its ability to accurately and efficiently measure lymphedema-related impact using modern psychometric techniques. Methods and Results: We collected a total of 1054 patient-reported outcome measure scores from 285 patients with upper extremity lymphedema and 65 patients with lower extremity lymphedema between 2016 and 2020. We first evaluated the relationship between the LLIS score, L-Dex score, and limb volume difference (LVD), and used classical test and item response theories to assess its psychometric performance. The LLIS score was only very weakly associated with LVD (r = 0.17, p < 0.001) and L-Dex score (r = 0.22, p < 0.001). The LLIS had acceptable dimensionality. Items 7 (affects body image) and 16 (affects proper fit of clothing/shoes) were locally dependent (Yen's Q3 = 0.45). Eight of the 17 items was interpreted differently between upper and lower limb lymphedema patients (pseudo R2 ≥ 0.01). The scoring structure required correction for items 9 (affects intimate relations) and 12 (manages lymphedema). Removing items 18 (infection occurrence) and 7 resulted in substantially improved item response theory model fit (Tucker-Lewis index = 0.93, comparative fix index = 0.95, root mean square error of approximation = 0.07, and root means square of the residual = 0.06). The relationships between the LLIS and objective measures of lymphedema remained weak following modification (LVD; r = 0.13, p = 0.01, L-Dex; r = 0.26, p < 0.001). Conclusion: We were able to slightly improve the psychometric properties of the LLIS. However, these improvements did not rectify apparent issues with construct validity and both versions of the LLIS displayed a weak relationship with objective measures of lymphedema severity.

Postmastectomy Radiation Therapy on Permanent Implants or Tissue Expanders: Which is Better?

OBJECTIVES: This study evaluates complications and reconstructive failure rates in implant-based reconstruction with radiotherapy. BACKGROUND: Postmastectomy radiotherapy may adversely affect breast reconstructive outcomes. However, the comparative effect of radiotherapy on direct-to-implant versus tissue expander-implant reconstruction has not been examined. METHODS: Single institution retrospective review was performed and patients were followed 2 to 10 years. RESULTS: Of 1566 patients, 265 patients received radiation (149 immediate implants and 116 tissue expanders). Demographics were similar except more smokers in the expander group (7.7% vs 1.3%; P = 0.012). Patients who received radiation with an expander in place had overall more complications (32.8% vs 11.4%; P < 0.001), skin necrosis (10.3% vs 4.0%; P = 0.043), wound breakdown (9.5% vs 2.7%; P = 0.029), and infections (16.4% vs 4.03%; P = 0.001) leading to a higher rate of explantation (16.4% vs 4.0%; P < 0.001). A radiation boost likewise predicted complications [odds ratio (OR) 2.199, 95% confidence interval (CI) 1.154-4.188, P = 0.017]. When comparing reconstructive outcomes, radiated expanders had a higher failure rate (21.6% vs 11.4%; P = 0.025). Revision for capsular contracture was similar between the 2 cohorts (11.4% vs 11.2%; P = 0.959) as were revision rates for contour asymmetry and breast asymmetry. In our multivariable logistic regression analysis, radiation to the expander had a higher risk of reconstruction failure than radiation to the permanent implant (OR 2.020, 95% CI 1.010-4.037, P = 0.047). CONCLUSION: Most patients had successful implant-based reconstructions after mastectomy and radiotherapy. Our study showed radiotherapy after direct-to-implant breast reconstruction had a lower rate of complications and reconstructive failure compared to tissue expander-implant reconstruction.

Webinar during COVID-19 Improves Knowledge of Changes to the Plastic Surgery Residency Application Process.

BACKGROUND: The COVID-19 pandemic has significantly impacted residency application process for all specialties, including plastic surgery residency. Almost all plastic surgery residency programs have suspended visiting sub-internship rotations. This study quantifies the impact of a webinar through an analysis of poll questions and a post-webinar survey sent to all registered participants. METHODS: A dedicated webinar was organized and held by the Harvard Plastic Surgery Residency Training Program. All attendees were asked several poll questions during the webinar. The 192 participants were also sent a post-webinar survey. RESULTS: The response rate was 68.2% (n = 131). Respondents were more confident about matching into a plastic surgery residency program at the end of the webinar compared with before the webinar (P < 0.001). Respondents who did not have a plastic surgery residency program at their home institution were less confident at the start of the webinar (P = 0.009). In addition, respondents who had not taken time off for research or for other endeavors during or after medical school were less confident about their chances to match at the start of the webinar (P = 0.034). CONCLUSIONS: An online webinar program increased confidence levels of medical students interested in applying for residency positions in plastic surgery. Residency programs should consider webinars as a method to inform and assist medical students during the upcoming application season.

Multidisciplinary Treatment to Restore Vision in Ocular Burns.

Periorbital burns generate contraction and distortion of periorbital soft tissue, causing eyelid malfunction, further contributing to loss of vision from corneal scarring or perforation. We present our multidisciplinary algorithm to restore vision in patients with burn-related bilateral corneal blindness with light perception. Chart review was performed for four consecutive burn patients requiring periocular reconstruction and keratoprosthesis. Initial treatment included globe coverage with eyelid releases and grafts. Strategy of corneal replacement was determined by eyelid position and function and sufficiency of tear production. All patients were corneal blind with light perception only and cicatricial ectropion. The eye with better visual prognosis was reconstructed. Eyelid reconstruction procedures consisted of lid releases with full-thickness skin graft (FTSG) or split-thickness skin graft (STSG). Two patients regained adequate lid function and underwent standard keratoprosthesis placement. Two underwent mucous membrane grafts followed by keratoprosthesis. All patients experienced improved postoperative vision in their reconstructed eye. Corneal injury due to periocular burns can lead to blindness. Early involvement of ophthalmology, protective measures, and early ectropion release are critical. For severe burns, a multidisciplinary approach, where adequate globe protection is followed by keratoprosthesis placement, can effectively restore vision in patients with burn-related corneal blindness.

Median Nerve Injury After Removal of Subdermal Implantable Contraceptive.

Background: Subdermal implantable contraceptives are highly effective, approved in over 60 countries, and used by millions of women. Due to simple insertion and removal protocols, these procedures are often performed in the outpatient clinic setting, and procedural complications are rare. However, given the location of the implant in the medial antebrachial interval, there is a risk of neurovascular injury, especially with malpositioned or deeply placed implants. Methods: We present a case of proximal median nerve injury leading to severe neuropathy after attempted removal of a subdermal implantable contraceptive requiring neurolysis and tendon transfers. Results: At 6 months post surgery, the patient regained flexion of the index interphalangeal joints and protective sensation in the thumb and index fingers. Conclusions: Subdermal implant retrieval can lead to nerve injury, despite the relative simplicity of the procedure. If difficulty is encountered, imaging or open retrieval should be considered. Improvement in function can be gained through operative interventions including neurolysis and tendon transfers in the setting of severe neuropathy.

Nipple-Sparing Mastectomy and Direct-to-Implant Breast Reconstruction.

Breast reconstruction following mastectomy has evolved to preserve the native skin and nipple of the breast and create a natural-appearing reconstruction in 1 or 2 surgeries. Nipple-sparing procedures appear to be oncologically safe with low risks of cancer recurrence. In our series of 2,182 nipple-sparing mastectomies, there was no development or recurrence of cancer in the nipple. Direct-to-implant single-stage surgery offers the patient a complete reconstruction at the time of mastectomy. Patient selection centers on preoperative breast anatomy combined with postoperative goals for size and uplift of the breast. The best candidates for nipple-sparing mastectomy and direct-to-implant breast reconstruction include those with grade I-II breast ptosis and those desiring to stay approximately the same breast size. The choice of incision and width of the implant play key roles in nipple centralization. Partial muscle coverage with acellular dermal matrix remains the most common technique to support the implant and offers the advantage of more soft-tissue coverage in the upper pole. With experience, complications and revisions are similar in this approach compared with more traditional 2-stage tissue expander-implant reconstruction. Thus, nipple-sparing mastectomy and direct-to-implant breast reconstruction is emerging as a preferred method of breast reconstruction when the breast skin envelope is sufficiently perfused.

Mesenchymal Stem Cells Enhance Nerve Regeneration in a Rat Sciatic Nerve Repair and Hindlimb Transplant Model.

This study investigates the efficacy of local and intravenous mesenchymal stem cell (MSC) administration to augment neuroregeneration in both a sciatic nerve cut-and-repair and rat hindlimb transplant model. Bone marrow-derived MSCs were harvested and purified from Brown-Norway (BN) rats. Sciatic nerve transections and repairs were performed in three groups of Lewis (LEW) rats: negative controls (n = 4), local MSCs (epineural) injection (n = 4), and systemic MSCs (intravenous) injection (n = 4). Syngeneic (LEW-LEW) (n = 4) and allogeneic (BN-LEW) (n = 4) hindlimb transplants were performed and assessed for neuroregeneration after local or systemic MSC treatment. Rats undergoing sciatic nerve cut-and-repair and treated with either local or systemic injection of MSCs had significant improvement in the speed of recovery of compound muscle action potential amplitudes and axon counts when compared with negative controls. Similarly, rats undergoing allogeneic hindlimb transplants treated with local injection of MSCs exhibited significantly increased axon counts. Similarly, systemic MSC treatment resulted in improved nerve regeneration following allogeneic hindlimb transplants. Systemic administration had a more pronounced effect on electromotor recovery while local injection was more effective at increasing fiber counts, suggesting different targets of action. Local and systemic MSC injections significantly improve the pace and degree of nerve regeneration after nerve injury and hindlimb transplantation.