Development of quantitative detection method for mass spectrometry coupled to an infrared laser spectroscope (Picarro) to monitor in nitrogen matrix a complex gas mixture of H2 , He, CO, N2 , Ne, O2 , Ar, CO2 , H2 S, CH4 , C2 H4 , C2 H6 , C3 H6 , C3 H8 , i-C4 H10 , n-C4 H10 , and C5 H12.

RATIONALE: The deep geological repository is considered the international reference for radioactive waste management. All gas exchanges must be understood in the context of the feasibility of such a repository. The technological challenge is to continuously monitor a wide range of gaseous molecules at low concentrations in confined spaces. METHODS: A gas monitoring station, composed of two complementary analyzers, was developed: an electron impact quadrupole mass spectrometer (HPR-20 R&D Hiden Analytical) and an infrared laser spectroscope (Picarro). The spectrometer was calibrated using simple mixtures (i.e., C2 H6 in N2 ) and multiple mixtures (i.e., H2 , He, CO2 , CH4 , and O2 in N2 ) at different concentrations to correct interferences. A matrix calculation is proposed to calculate the relative concentrations. RESULTS: The method developed allows the measurement of gaseous species: light hydrocarbons, noble gases, sulfides, greenhouse gases, oxygen, hydrogen, and nitrogen in the same mixture. For each gas, the SDs and the limits of detection and quantification were calculated. The method was validated by comparing the concentrations of the measured gas species with the reference values of two standard gas cylinders. CONCLUSIONS: Calibration of a complex gas mixture remains a challenge because fragmentation of molecules, especially hydrocarbons, reduces the sensitivity of the method. The method developed is suitable for continuous gas monitoring in a confined environment and can be implemented to perform experiments in underground structures: galleries, microtunnels (cells), and boreholes.

What Is the Minimum Number of Sutures for Microvascular Anastomosis during Replantation?

As vessel diameter decreases, reperfusion after anastomosis becomes more difficult. When a blood vessel is sutured, its inner diameter becomes narrower owing to the thickness of the suture material and the number of sutures. To minimize this, we attempted replantation using a 2-point suture technique. We reviewed cases of arterial anastomosis in vessels with a diameter of less than 0.3 mm during replantation performed over a four-year period. In all cases, close observation was followed by absolute bed rest. If reperfusion was not achieved, a tie-over dressing was applied, and hyperbaric oxygen therapy was administered in the form of a composite graft. Of the 21 replantation cases, 19 were considered successful. Furthermore, the 2-point suture technique was performed in 12 cases, of which 11 survived. When three or four sutures were performed in nine patients, eight of these cases survived. Composite graft conversion was found in three cases in which the 2-point suture technique was used, and two of these cases survived. The survival rate was high in cases where 2-point sutures were used, and there were few cases of conversion to a composite graft. Reducing the number of sutures aids in optimizing reperfusion.

Improvement of Heat Resistance of Fluorosilicone Rubber Employing Vinyl-Functionalized POSS as a Chemical Crosslinking Agent.

Fluorosilicone rubber (F-LSR) is a promising material that can be applied in various cutting-edge industries. However, the slightly lower thermal resistance of F-LSR compared with that of conventional PDMS is difficult to overcome by applying nonreactive conventional fillers that readily agglomerate owing to their incompatible structure. Polyhedral oligomeric silsesquioxane with vinyl groups (POSS-V) is a suitable material that may satisfy this requirement. Herein, F-LSR-POSS was prepared using POSS-V as a chemical crosslinking agent chemically bonded with F-LSR through hydrosilylation. All F-LSR-POSSs were successfully prepared and most of the POSS-Vs were uniformly dispersed in the F-LSR-POSSs, as confirmed by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H-NMR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) measurements. The mechanical strength and crosslinking density of the F-LSR-POSSs were determined using a universal testing machine (UTM) and dynamic mechanical analysis (DMA), respectively. Finally, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements confirmed that the low-temperature thermal properties were maintained, and the heat resistance was significantly improved compared with conventional F-LSR. Eventually, the poor heat resistance of the F-LSR was overcome with three-dimensional high-density crosslinking by introducing POSS-V as a chemical crosslinking agent, thereby expanding the potential fluorosilicone applications.

Correlation between acellular dermal matrix (ADM) volume and breast implant size selection among patients undergoing prepectoral direct-to-implant (DTI) breast reconstruction using complete ADM.

BACKGROUND: In prepectoral direct-to-implant breast reconstruction using the acellular dermal matrix (ADM)-assisted technique, breast volume asymmetry can occur. We hypothesized that ADM size influences implant size selection in prepectoral breast reconstruction with implant coverage using an ADM. We investigated factors influencing implant size selection and provide guidelines for surgeons. METHODS: A retrospective chart review was performed to identify all patients who underwent prepectoral direct-to-implant breast reconstruction between January 2017 and October 2020. We assessed patient characteristics, preoperative expected implant volume, ADM size, volume of implant used in surgery, and symmetry scale of aesthetic item scale (AIS) 6 months after surgery. We compared the symmetry score of AIS between a group in which the preoperative expected silicone implant size (ES) was used and a group in which a silicone implant of a smaller size than planned (SS) was used. RESULTS: Patient characteristics, including age, body mass index (BMI), and excised breast volume, were similar between the groups (P > .05). ADM size had a significant effect on implant size selection (odds ratio = 1.760, P < .01). The symmetry score of AIS was higher in the SS group. CONCLUSIONS: ADM size must be considered when selecting implant size in prepectoral direct-to-implant breast reconstruction using the ADM-assisted technique.

"Tear-Drop Appearance" Wrap: A Novel Implant Coverage Method for Creating Natural Contour in Prepectoral Prosthetic-Based Breast Reconstruction.

Various implant wrapping methods with acellular dermal matrix (ADM) have been introduced, but most focus on random trimming and suturing aimed to maximize implant coverage. Here we present our clinical experience using a "tear-drop appearance" wrapping method to achieve natural contours through upper pole volume replacement. We retrospectively reviewed the data of 56 consecutive cases of prepectoral prosthetic-based breast reconstruction (PPBR) using this wrapping method following nipple-sparing mastectomy between March 2020 and June 2021. The "tear-drop appearance" wrapping design creates an anatomical tear-drop-shaped pocket to encourage lower pole fullness and create a natural contour through upper pole volume replacement by ADM. Patients' baseline characteristics, operative data, and complications were analyzed. Aesthetic outcomes were measured using the BREAST-Q and Aesthetic Item Scale (AIS). A successful reconstruction was achieved without major complications and using a single ADM sheet. Four types and three sizes of ADMs were used. The mean resected breast tissue weight was 274.3 g, while the mean implant volume was 230.0 cc. The average BREAST-Q and AIS scores were 4.6 ± 0.8 and 4.5 ± 0.7, respectively. Owing to its simplicity, reproducibility, and effectivity, this method is an excellent implant coverage option that achieves a natural contour in PPBR.

Review of 107 Oncoplastic Surgeries Using an Acellular Dermal Matrix with the Round Block Technique.

The round block technique (RBT) is an oncoplastic surgery method that uses volume displacement techniques after partial mastectomy. However, cosmetic problems occur after tissue rearrangement in patients with small breasts or those in whom a large amount of breast tissue is excised. Therefore, we used an acellular dermal matrix (ADM) when the volume was insufficient after tissue rearrangement. Patients who underwent breast reconstruction using the ADM with the RBT after breast-conserving surgery (BCS) were included. The ADM graft was performed in two layers. First, it was placed on the glandular flap, and the patient was then seated to ascertain the degree of deformity. If the volume was insufficient, a graft was also performed under the skin flap. Overall, 107 oncoplastic surgeries were performed. Tumors were most commonly located in the upper outer quadrant of the breast, and the mean resected breast tissue was 27.1 g. Seroma was the most common complication, but it improved with several aspirations. There were no major complications or cosmetic problems requiring reoperation. Therefore, if the ADM was used for defects that could not be reconstructed with the RBT alone, safe and cosmetically good results could be obtained.

Staged Chest Wall Reconstruction for Radiation-induced Costochondritis.

Costochondritis after breast reconstruction and radiation therapy is rarely reported. Moreover, it is difficult to diagnose using computed tomography and magnetic resonance imaging; as such, wound debridement and reconstruction must be performed in several stages. A 51-year-old woman was diagnosed with invasive cancer of the right breast, and she underwent nipple sparing mastectomy and direct-to-implant breast reconstruction in November 2007. Thirteen years later, in September 2020, she experienced pain and swelling on her right breast. Incisional drainage and implant removal were performed in another clinic; however, the infection was not controlled. An implant-induced infection was suspected, and debridement was performed to a level where fresh tissue appeared in the upper layer of the intercostal muscle. Antibiotics and open dressing were used for 10 days; however, yellowish debris was noted, and third to fifth ribs and costal cartilages turned dark brown. Radiation-induced costochondritis was diagnosed based on clinical findings from the intraoperative field, wound course, and cartilage biopsy. Radical chest wall resection and reconstruction was performed using Teflon (Dupont/Chemours, Wilmington, Del.) and latissimus dorsi musculocutaneous flap. The patient was discharged 2 weeks after surgery without any complications. Costochondritis should be clinically diagnosed while performing the first debridement in staged operation. Radical chest wall resection is essential with chest wall reconstruction using Teflon and a latissimus dorsi musculocutaneous flap.

Factors Influencing Patient Satisfaction with Upper Blepharoplasty in Elderly Patients.

Upper blepharoplasty in elderly patients has characteristics that differ from those of younger patients. Blepharoptosis in elderly patients causes not only aesthetic problems but also functional problems such as entropion, visual disturbance, and sore eyes. We hypothesized that factors influencing patient satisfaction with upper blepharoplasty in elderly patients include aesthetic outcomes, functional outcomes, and personal factors. METHODS: This study included 57 patients aged >65 years who underwent upper blepharoplasty between April 2018 and March 2019. All surgeries were performed through the "Upper Blepharoplasty Service Project" of the public health center in Geoje City. To evaluate the individual characteristics of the patients, a preoperative questionnaire (including sociodemographic characteristics, main symptoms of discomfort in the upper eyelid, and degree of expectation of surgical results) was administered to the patients. After 6 months, a satisfaction survey was conducted accordingly. RESULTS: The main symptoms of discomfort were sagging of the skin of the upper eyelid. The mean score for patient satisfaction was 3.84 ± 0.40, and satisfaction with the results of surgery relative to the cost was 4.53 ± 0.63, which was the highest score. Significant verification of the regression coefficients showed that functional improvement and cognitive degree of postsurgery precautions had a significant effect on patient satisfaction, whereas aesthetic outcomes and expectations of surgical results were not correlated with patient satisfaction. CONCLUSION: The findings indicated that elderly patients tended to be satisfied with functional improvement that resolved their symptoms of discomfort and personal factors such as cost and cognitive degree of precautions after upper blepharoplasty.