Elongation of intercostal nerve cutaneous branches for breast and nipple neurotization during breast reconstruction after mastectomy for breast cancer: case-control study.

BACKGROUND: To restore sensation after breast reconstruction, a modified surgical approach was employed by identifying the cut fourth intercostal lateral cutaneous branch, elongating it with intercostal nerve grafts, and coapting it to the innervating nerve of the flap or by using direct neurotization of the spared nipple/skin. METHODS: This was a retrospective case-control study including 56 patients who underwent breast neurotization surgery. Breast operations included immediate reconstruction after nipple-sparing mastectomy (36 patients), skin-sparing mastectomy (8 patients), and delayed reconstruction with nipple preservation (7 patients) or without nipple preservation (5 patients). Patients who underwent breast reconstruction without neurotization were included as the non-neurotization negative control group. The contralateral normal breasts were included as positive controls. RESULTS: The mean(s.d.) monofilament test values were 0.07(0.10) g for the positive control breasts and 179.13(143.31) g for the breasts operated on in the non-neurotization group. Breasts that underwent neurotization had significantly better sensation after surgery, with a mean(s.d.) value of 35.61(92.63) g (P < 0.001). The mean(s.d.) sensory return after neurotization was gradual; 138.17(143.65) g in the first 6 months, 59.55(116.46) g at 7-12 months, 14.54(62.27) g at 13-18 months, and 0.37(0.50) g at 19-24 months after surgery. Two patients had accidental rupture of the pleura, which was repaired uneventfully. One patient underwent re-exploration due to a lack of improvement 1.5 years after neurotization. CONCLUSION: Using the lateral cutaneous branch of the intercostal nerve as the innervating stump and elongating it with intercostal nerve grafts is a suitable technique to restore sensation after mastectomy. This method effectively innervates reconstructed breasts and spares the nipple/skin with minimal morbidity.

DIEP Donor Site Satisfaction between Patients with and without History of Pregnancy.

BACKGROUND: With the success of free autologous breast reconstruction, the abdominal donor site is now an important consideration, especially in patients of childbearing age. In our institution, there are increasing patients who have successfully undergone the deep inferior epigastric artery perforator (DIEP) flap despite previous pregnancy. This study aims to answer questions on the effect of the donor site on pregnancy and vice versa. METHODS: A retrospective cohort study was conducted to identify breast cancer patients who received a free DIEP flap for breast reconstruction from January 2018 to August 2020. Patients were allocated to two groups according to whether they had prior pregnancies with successful deliveries. Demographics, flap-related parameters, surgical outcomes on breast and abdomen, and patient-reported outcome (Breast-Q questionnaire) were analyzed. Patients were excluded if follow-up time was less than 1 year, or if there was incomplete medical records or Breast-Q replies. RESULTS: Ninety-nine of 116 patients had had successful pregnancies with delivery, 17 of them remained nulliparous. No statistically significant differences existed between groups regarding demographic data, flap-related parameters, surgical outcomes on breast and abdomen. Nulliparous patients exhibited significantly lower score in physical well-being in the abdomen domain compared with delivery-experienced patients (62.1 vs. 73.4, p = 0.025). Significantly, nulliparous patients felt more tightness and pulling of the abdominal wall than the delivery-experienced patients (2.9 vs. 3.7; p = 0.05 and 3.5 vs. 4.0; p = 0.04). CONCLUSION: Free DIEP flap can be transferred safely in nulliparous patients despite a slight increase in abdominal tightness and abdominal pulling. Precise flap design and surgical approaches may help to minimize the abdominal discomfort especially on young, normal body mass index, and nonchildbearing patients.

Prevalence of drug resistance mutations in HIV-infected individuals with low-level viraemia under combination antiretroviral therapy: an observational study in a tertiary hospital in Northern Taiwan, 2017-19.

BACKGROUND: Effective ART is crucial for combating the HIV pandemic. Clinically, plasma viral load monitoring to achieve virological suppression is the guide for an optimal ART. The presence of low-level viraemia (LLV) below the definition level of virological failure is a risk factor for ART failure. However, there is no treatment consensus over LLV yet, mainly due to the limitation of standard HIV-RNA genotyping and the resultant insufficient understanding of LLV characteristics. OBJECTIVES: To better profile drug resistance mutations (DRMs) and the associated factors in cases experiencing LLV. METHODS: A prospective observational study was conducted from 2017 to 2019. HIV-DNA was used as an alternative to HIV-RNA for HIV genotyping coupled with deep sequencing for ART-naive and ART-failure cases, as well as those with LLV. RESULTS: Eighty-one ART-naive, 18 ART-failure and 16 LLV cases received HIV genotyping in the study. Three-quarters (12/16) of cases experiencing LLV harboured DRMs. Cases with LLV had higher prevalence of DRMs to NNRTIs than the ART-naive group (69% versus 20%, P < 0.001), but lower DRM prevalence to NRTIs than the ART-failure group (25% versus 61%, P < 0.001). Approximately half of the LLV cases had issues of suboptimal ART compliance/ART interruption, and 68.8% (11/16) did not display drug resistance to their ART at the time of LLV. CONCLUSIONS: HIV DRM profiles in LLV cases were significantly different to those in ART-naive and ART-failure cases. Approaches to consolidate ART compliance and early exploration of potential ART resistance may be needed for cases experiencing LLV episodes.

The vascularized periosteum flap as novel tissue engineering model for repair of cartilage defects.

Periosteum is a promising tissue engineering scaffold in research of cartilage repair; so far however, periosteum transfers have not been realized successfully because of insufficient nourishment of the graft. In a translational approach we, for the first time, designed a vascularized periosteum flap as 'independent' biomaterial with its own blood supply to address this problem and to reconstruct circumscript cartilage defects. In six 3-month-old New Zealand rabbits, a critical size cartilage defect of the medial femur condyle was created and covered by a vascularized periosteum flap pedicled on the saphenous vessels. After 28 days, formation of newly built cartilage was assessed macroscopically, histologically and qualitatively via biomechanical compression testing, as well as on molecular biological level via immunohistochemistry. All wounds healed completely, all joints were stable and had full range of motion. All flaps survived and were perfused through their pulsating pedicles. They showed a stable attachment to the bone, although partially incomplete adherence. Hyaline cartilage with typical columnar cell distribution and positive Collagen II staining was formed in the transferred flaps. Biomechanical testing revealed a significantly higher maximum load than the positive control, but a low elasticity. This study proved that vascularization of the periosteum flap is the essential step for flap survival and enables the flap to transform into cartilage. Reconstruction of circumscript cartilage defects seems to be possible. Although these are the first results out of a pilot project, this technique, we believe, can have a wide range of potential applications and high relevance in the clinical field.

Six steps for a successful aesthetic free flap reconstruction after minimally invasive mastectomy: a retrospective case-control study.

OBJECTIVE: Breast cancer treatment has evolved to the modern skin-sparing mastectomy and nipple-sparing mastectomy. To better perform these surgeries, minimally invasive techniques using the endoscope, or Da Vinci Robotic Surgery platform have been developed. The deep inferior epigastric perforator (DIEP) flap is the gold standard in breast reconstruction, but it is still not commonly performed after minimally invasive mastectomy due technical difficulty. Here the authors introduced six key steps to a successful aesthetic autologous free flap reconstruction in in minimally invasive mastectomies. METHODS: There are six main steps to our technique: placement of mastectomy incision, precise flap design after angiography studies, trial of shaping, transcutaneous medial suture, footprint recreation and postoperative shaping with bra. Between November 2018 and July 2022, a total of 67 immediate breast reconstructions using free perforator flaps were performed in 63 patients after minimally invasive nipple-sparing mastectomy. RESULTS: The results from the minimally invasive mastectomy group were compared with a group of conventional mastectomy patients ( n= 41) performed during the same period. There were no significant differences in flap exploration rates. One hundred percent of the flaps survived. In the minimally invasive group, the final scar was placed in the lateral region, where it would be hidden from the anterior view. Only 70.7% of the conventional mastectomy group could achieve a hidden lateral scar ( P <0.001). The aesthetic revision rates were similar between two groups. CONCLUSION: With attention to the six steps above, autologous free flap reconstruction can be offered reliably in the setting of minimally invasive mastectomy.

Labiaplasty in Asian women: Motivation, technique feasibility, and patient reported outcomes.

Labiaplasty is an increasingly popular aesthetic procedure. However, there is a lack of information regarding different surgical procedures and Asian patients' motivations and outcomes. This study aimed to understand patients' motivations for seeking labiaplasty and to examine surgical outcomes of different procedures. This retrospective study enroled patients between August 2016 and May 2021. Patient demographics, surgical procedures, complications, and revision surgeries were reviewed. Responses to questionnaires regarding patient motivations for undergoing labiaplasty, pre- and postoperative discomfort and aesthetics, Rosen's Self-Esteem Scale (RSES) scores, and Female Genital Self-Image Scale (FGSIS) scores were recorded. One hundred thirty-one patients were included, with an average age of 30.3 ± 7.78 years. Eighty-seven (66.4%) patients underwent bilateral labiaplasty, and 44 (33.6%) underwent unilateral labiaplasty. The surgical techniques included 61 (46.6%) direct resections, 50 (38.2%) wedge resections, and 20 (15.3%) "hockey stick" procedures. Wound dehiscence occurred in 37 (28.2%) patients. A significant increase in complications occurred after the hockey stick procedure and wedge resection. Patients' motivation for surgery included aesthetic reasons in 62.0%, symptom relief in 91.5%, and repeated infection in 4.2%. There was a significant difference between pre- and postoperative genital aesthetics (p 0.001) and discomfort symptoms (p 0.001). The average RSES score was 19.68 ± 4.03, and the average FGSIS score was 20.77 ± 3.20. Pain and discomfort remained the most important motivations for Asian women to seek labiaplasty, followed by aesthetic reasons. With good preoperative consultation and surgical planning, satisfaction can be achieved concerning functional and aesthetic aspects.

Changes in interferon-γ release assay readout after COVID-19 vaccination: A prospective cohort study.

OBJECTIVES: Interferon-γ release assays (IGRAs) are widely used in public health practice to diagnose latent tuberculosis. During the COVID-19 pandemic and rollout of COVID-19 vaccination, it has remained unclear whether COVID-19 vaccines interfere with IGRA readouts. METHODS: We prospectively recruited healthcare workers during their annual occupational health examinations in 2021. Baseline IGRA readouts were compared with follow-up data after the participants had received two doses of COVID-19 vaccination. RESULTS: A total of 134 baseline IGRA-negative cases (92 with ChAdOx1 vaccine, 27 with mRNA-1273 vaccine, and 15 with heterologous vaccination) and seven baseline IGRA-positive cases were analyzed. Among the baseline IGRA-negative cases, there were decreased interferon-γ concentrations over the Nil (P = 0.005) and increased Mitogen-Nil (P < 0.001) values after vaccination. For TB2-Nil value, a similar trend (P = 0.057) of increase was observed. Compared with the 0.35 IU/ml threshold, the baseline and follow-up readout differences were less than |± 0.10| IU/ml over the TB1-Nil and TB2-Nil values in >90% baseline IGRA-negative cases. No significant readout difference was observed among baseline IGRA-positive cases. CONCLUSION: COVID-19 vaccination did not change IGRA interpretation in most cases. Cases showing conversion/borderline IGRA readouts should be given special consideration.

The effect of bone inhibitors on periosteum-guided cartilage regeneration.

The regeneration capacity of knee cartilage can be enhanced by applying periosteal grafts, but this effect varies depending on the different sources of the periosteal grafts applied for cartilage formation. Tibia periosteum can be used to enhance cartilage repair. However, long-term analysis has not been conducted. The endochondral ossification capacity of tibia periosteum during cartilage repair also needs to be investigated. In this study, both vascularized and non-vascularized tibia periosteum grafts were studied to understand the relationship between tissue perfusion of the periosteum graft and the effects on cartilage regeneration and bone formation. Furthermore, anti-ossification reagents were added to evaluate the efficacy of the prevention of bone formation along with cartilage regeneration. A critical-size cartilage defect (4 × 4 mm) was created and was covered with an autologous tibia vascularized periosteal flap or with a non-vascularized tibia periosteum patch on the knee in the rabbit model. A portion of the vascularized periosteum group was also treated with the anti-osteogenic reagents Fulvestrant and IL1ß to inhibit unwanted bone formation. Our results indicated that the vascularized periosteum significantly enhanced cartilage regeneration in the cartilage defect region in long-term treatment compared to the non-vascularized group. Furthermore, the addition of anti-osteogenic reagents to the vascularized periosteum group suppressed bone formation but also reduced the cartilage regeneration rate. Our study using vascularized autologous tissue to repair cartilage defects of the knee may lead to the modification of current treatment in regard to osteoarthritis knee repair.

Shall I trust the report? Variable performance of Sanger sequencing revealed by deep sequencing on HIV drug resistance mutation detection.

BACKGROUND: The clinical utilisation of deep sequencing in HIV treatment has been hindered due to its unknown correlation with standard Sanger genotyping and the undetermined value of minority drug resistance mutation (DRM) detection. OBJECTIVES: To compare deep sequencing performance to standard Sanger genotyping with clinical samples, in an effort to delineate the correlation between the results from the two methods and to find the optimal deep sequencing threshold for clinical utilisation. METHODS: We conducted a retrospective study using stored plasma collected from August 2014 to March 2018 for HIV genotyping with the commercial Sanger genotyping kit. Samples with available Sanger genotyping reports were further deep sequenced. Drug resistance was interpreted according to the Stanford HIV drug resistance database algorithm. RESULTS: At 15-25% minority detection thresholds, 9-15% cases had underestimated DRMs by Sanger sequencing. The concordance between the Sanger and deep sequencing reports was 68-82% in protease-reverse transcriptase region and 88-97% in integrase region at 5-25% thresholds. The undetected drug resistant minority variants by Sanger sequencing contributed to the lower negative predictive value of Sanger genotyping in cases harbouring DRMs. CONCLUSIONS: Use of deep sequencing improved detection of antiretroviral resistance mutations especially in cases with virological failure or previous treatment interruption. Deep sequencing with 10-15% detection thresholds may be considered a suitable substitute for Sanger sequencing on antiretroviral DRM detection.

Perfusion Bioreactor Culture of Bone Marrow Stromal Cells Enhances Cranial Defect Regeneration.

BACKGROUND: Cell-seeded biomaterial scaffolds have been proposed as a future option for reconstruction of bone tissue. The ability to generate larger, functional volumes of bone has been a challenge that may be addressed through the use of perfusion bioreactors. In this study, the authors investigated use of a tubular perfusion bioreactor system for the growth and differentiation of bone marrow stromal (mesenchymal stem) cells seeded onto fibrin, a highly angiogenic biomaterial. METHODS: Cells were encapsulated within fibrin beads and cultured either within a tubular perfusion bioreactor system or statically for up to 14 days. Scaffolds were analyzed for osteogenic differentiation. A rodent cranial defect model (8-mm diameter) was used to assess the bone regeneration of scaffolds cultured in the bioreactor, statically, or used immediately after formation. Immunohistochemistry was used to visualize CD31 vessel density. Micro-computed tomographic imaging was used to visualize mineral formation within the defect volume. RESULTS: Tubular perfusion bioreactor system-cultured samples showed significantly greater osteodifferentiation, indicated by an increase in VEGF expression and mineral deposition, compared with statically cultured samples. Increased expression of OPN, RUNX2, VEGF, and CD90 was seen over time in both culture methods. After implantation, bioreactor samples exhibited greater bone formation and vessel density compared with all other groups. Analysis of micro-computed tomographic images showed full union formation through the greatest diameter of the defect in all bioreactor samples and the highest levels of mineralized volume after 8 weeks. CONCLUSION: Mesenchymal stem cells encapsulated in fibrin beads and cultured in the tubular perfusion bioreactor system resulted in increased vascularization and mineralized tissue formation in vivo relative to static culture.

Investigation of Dermis-derived hydrogels for wound healing applications.

BACKGROUND: Wound healing and skin tissue engineering are mediated, in part, by interactions between cells and the extracellular matrix (ECM). A subset of the ECM, basement membranes (BM), plays a vital role in regulating proper skin healing and function. METHODS: ECM-rich, tissue-specific hydrogels were extracted and assembled from dermis samples. These hydrogels contain BM proteins vital to skin regeneration, including laminin ß3, collagen IV, and collagen VII. The extracts could be assembled to form hydrogels by either temperature or pH mechanism, with the mechanical properties and structure varying with the mechanism of assembly. A wound healing model was developed to investigate the ability of these hydrogels to enhance healing with a single application in vivo. RESULTS: The pH, but not temperature gels were easily applied to the wounds. There were no signs of increased inflammation due to the application of the hydrogels. The width of granulation tissue at the first week was reduced (p = 0.064) relative to controls with the application of hydrogel. There were no changes in wound closure rates or vessel density. CONCLUSIONS: Dermis-derived hydrogels contain BM proteins important for skin regeneration. They can be easily applied, but their poor mechanical strength and rapid degradation may hinder their biological effects.

The role of pore size on vascularization and tissue remodeling in PEG hydrogels.

Vascularization is influenced by the physical architecture of a biomaterial. The relationship between pore size and vascularization has been examined for hydrophobic polymer foams, but there has been little research on tissue response in porous hydrogels. The goal of this study was to examine the role of pore size on vessel invasion in porous poly(ethylene glycol) (PEG) hydrogels. Vascularized tissue ingrowth was examined using three-dimensional cell culture and rodent models. In culture, all porous gels supported vascular invasion with the rate increasing with pore size. Following subfascial implantation, porous gels rapidly absorbed wound fluid, which promoted tissue ingrowth even in the absence of exogenous growth factors. Pore size influenced neovascularization, within the scaffolds and also the overall tissue response. Cell and vessel invasion into gels with pores 25-50 µm in size was limited to the external surface, while gels with pores larger pores (50-100 and 100-150 µm) permitted mature vascularized tissue formation throughout the entire material volume. A thin layer of inflammatory tissue was present at all PEG-tissue interfaces, effectively reducing the area available for tissue growth. These results show that porous PEG hydrogels can support extensive vascularized tissue formation, but the nature of the response depends on the pore size.

The effect of FGF-1 loaded alginate microbeads on neovascularization and adipogenesis in a vascular pedicle model of adipose tissue engineering.

Engineered vascularized adipose tissue could serve as an alternative to traditional tissue reconstruction procedures. Adipose formation occurs in a coordinated fashion with neovascularization. Previous studies have shown that extracellular matrix-based materials supplemented with factors that stimulate neovascularization promote adipogenesis in a number of animal models. The present study examines the ability of fibroblast growth factor (FGF-1) delivered from alginate microbeads to induce neovascularization and adipogenesis in type I collagen gels in a vascular pedicle model of adipose tissue engineering. FGF-1 loaded microbeads stimulated greater vascular network formation in an in vitro 3D co-culture model than a single bolus of FGF-1. In in vivo studies, FGF-1 loaded beads suspended in collagen and implanted in a chamber surrounding the exposed femoral pedicle of a rat resulted in a significant increase in vascular density at 1 and 6 weeks in comparison to bolus administration of FGF-1. Staining for smooth muscle actin showed that over 48% of vessels had associated mural cells. While an increase in neovascularization was achieved, there was less than 3% adipose under any condition. These results show that delivery of FGF-1 from alginate beads stimulated a more persistent neovascularization response than bolus FGF-1 both in vitro and in vivo. However, unlike previous studies, this increased neovascularization did not result in adipogenesis. Future studies need to provide a better understanding of the relationship between neovascularization and adipogenesis in order to design advanced tissue engineering therapies.