Fill Volume Research Articles

Relationship between fill volume and transport in peritoneal dialysis-from bench to bedside.

Larger fill volumes in peritoneal dialysis (PD) typically improve small solute clearance and water removal, and vice versa-but the relationship between intraperitoneal volume and the capacities for solute and water transport in PD has been little studied. Here, it is proposed that this relative relationship is described by a simple ratio (Volumenew/Volumeold)2/3 up to a critical break-point volume, beyond which further volume increase is less beneficial in terms of solute and water removal. To scrutinize this hypothesis, experiments were conducted in a rat model of PD alongside a retrospective analysis of data from a prior clinical study. Rats underwent PD with either three consecutive fills of 8 + 8 + 8 mL (n = 10) or 12 + 12 + 12 mL (n = 10), with 45-minute dwell time intervals. This approach yielded 60 estimations of water and solute transport, characterized by osmotic conductance to glucose and solute diffusion capacities, respectively. Comparative analysis of the predictive efficacy of the two models-the simple ratio versus the break-point model-was performed using Monte Carlo cross-validation. The break-point model emerged as a superior predictor for both water and solute transfer, demonstrating its capability to characterize both experimental data from rats and clinical data from patients. The present analysis indicates that relatively simple calculations can be used to approximate clinical effects on solute and water removal when prescribing a lower or higher fill volume to patients with PD.

Comparison of Clinical Outcomes between High-Start and Low-Start Dialysate Fill Volume among Patients with CKD on Peritoneal Dialysis at the National Kidney and Transplant Institute: A Randomized Controlled Trial

Comparison of Clinical Outcomes between High-Start and Low-Start Dialysate Fill Volume among Patients with CKD on Peritoneal Dialysis at the National Kidney and Transplant Institute: A Randomized Controlled Trial

Comprehensive investigation of factors influencing the degradation of polysorbate 20: Insights into mechanisms and interactions using a design of experiments approach

This study investigates the degradation of polysorbate 20 (PS20 HP) in a protein-free formulation under various storage conditions, examining the factors (i) Fe2+, (ii) Fe3+, (iii) H2O2, (iv) glass vial type, (v) fill volume, (vi) oxygen concentration, (vii) PS20 HP batches, (viii) light exposure before storage, and (ix) storage time by a design of experiments approach. In order to ascertain the impact of the factors under examination, realistic concentration ranges have been selected on the basis of observations made in industrial settings. The findings of our investigation demonstrate that the presence of Fe2+ and Fe3+, in addition to oxygen, has a significant influence on the degradation of PS20 HP, with Fe2+ exerting a more pronounced effect. The reduction of the oxygen content through nitrogen degassing has been demonstrated to have a pronounced inhibitory effect on PS20 HP degradation, even in the presence of iron ions. Interestingly, the concentration of intact PS20 HP was not significantly affected by H2O2 (tested concentration: 29.4 μM (1 ppm)). Furthermore, other factors including fill volume, PS20 HP batch, and light exposure, did not exert a statistically significant impact on the degradation of PS20 HP over a 12-month period in relation to the other factors.

The new rheological model for zirconia suspensions with long-term kinetic stability

For successful 3D printing based on stereolithography technologies, one of the most important factors influencing the success of printing is the dynamic viscosity of the prepared suspension. For the purposes of viscosity prediction at different volume fillings, two ZrO2 powders with different yttrium content (CY3Z-RS and CY8Z-RS) with volume filling 0–40 % in two different dispersing mediums at two temperatures were investigated in this paper. The dependence of relative viscosity on volumetric filling was fitted by existing models and a new semi-empirical model based on experimental data was proposed and successfully plotted. Fitted data for all zirconia photosensitive suspensions showed a high correlation to the proposed model (R2 from 97.02 % to 99.61 %). The model in addition to the possibilities of mathematical generalization of his prescription, introduces a fitting parameter C, which is thought to be thermodynamically influenceable and predictable. Furthermore, another key characteristic that is often neglected in rheological characterization, the stability of prepared ceramic suspensions, was verified either by rheological measurements but also by employing prospective technology based on analytical centrifuge. It was confirmed that all prepared suspensions were highly stable, and all instability indexes reached values less than 0.05.

Comparing Cortiva Silhouette to AlloDerm for Use in Prepectoral Two-stage Prosthetic Breast Reconstruction.

The use of acellular dermal matrices (ADMs) in implant-based breast reconstruction has become increasingly routine during the past 20 years. ADMs improve soft-tissue support, facilitate greater tissue expander (TE) fill volumes, and reduce rates of capsular contracture. As the ADM market continues to grow, outcomes studies are necessary to assess the risks and benefits of each product. In this study, we compare the performance of Cortiva Silhouette, the thinnest ADM widely available, to AlloDerm, commonly considered the industry standard. We performed a retrospective review of 178 consecutive two-stage prosthetic breast reconstructions performed by the senior author. In every case, either Cortiva or AlloDerm was used to provide soft-tissue support during TE placement. Subjects were divided into Cortiva and AlloDerm cohorts and compared across patient characteristics and reconstructive outcomes variables. During the study period, AlloDerm was used in 116 reconstructions; Cortiva was used in 62. After propensity score matching (62 AlloDerm, 62 Cortiva), Cortiva was associated with greater intraoperative and final TE fill volumes, as well as larger silicone implants. Cortiva was also associated with fewer complications overall, and fewer instances of mastectomy skin necrosis, delayed wound healing, and seroma. Cortiva Silhouette is noninferior to AlloDerm in terms of safety and providing soft-tissue support in prepectoral two-stage implant-based breast reconstruction. In this study, Cortiva supported greater TE fill volumes and larger silicone implants relative to AlloDerm and was associated with fewer complications.

Modeling the thermal and hydrodynamic performance of grooved wick flat heat pipes

A compact model is developed to predict the thermal and hydrodynamic performance of a flat heat pipe with a rectangular grooved wick. The present model relies on the analytical solution to the energy equation in the wall and an equivalent heat transfer coefficient predicted using a computationally efficient iterative method. This efficient iterative method can also provide a framework for modeling other grooved or porous wick heat pipes for which analytical or semi-analytical solutions to the wall conduction, fluid flow, and film equations exist. Compared to prior numerical tools, the present modeling approach is computationally efficient, making it compelling for use in parametric and optimization studies. Instead of numerically solving a set of coupled differential equations, the present model considers only analytical and semi-analytical solutions for evaporation and condensation heat transfer rates. The non-discretized nature of the present model allows computations on a typical workstation to be completed within seconds as opposed to the hours required for prevalent numerical tools. The present model accounts for varying liquid fill volumes, geometry, and interfacial properties, such as surface tension and contact angle. The present model closely agrees with published numerical and experimental results for wall temperatures and maximum heat transfer rates. Parametric studies, which vary wall thermal conductivity, water contact angle, and groove dimensions are conducted on a previously experimentally investigated heat pipe to demonstrate the present model’s capabilities. The present model found that the maximum heat transfer rate of the heat pipe can be enhanced by about 15 and 20% by varying its wetting angle and groove dimensions, respectively.

Development of a Stable Lyophilized Cyclophosphamide Monohydrate Formulation Using Non-Aqueous Solvents.

To ensure product stability, it is critical to maintain the monohydrate state of cyclophosphamide following lyophilization, as this is the most stable solid form of the Cyclophosphamide. On the other hand, because of their limited aqueous solubility and stability, non-aqueous solvents are preferred for determining the composition and stability of bulk solutions. Hence, the purpose of this study was to use non-aqueous solvents for determining the composition and stability of bulk solutions, and to shorten the lyophilization process by retaining the cyclophosphamide monohydrate. Furthermore, prior to selecting the solvent for the bulk solution consisting of 90:10 tertiary butyl alcohol (TBA) and acetonitrile (ACN), various factors were taken into account, including the freezing point, vapor pressure of solvents, solubility, and stability of cyclophosphamide monohydrate. The concentration of the bulk solution was adjusted to 200mg/mL in order to optimize the fill volume, enhance sublimation rates at lower temperatures during primary drying, and eliminate the need for secondary drying. The differential scanning calorimetry (DSC) measurements of bulk solution were used to improve the lyophilization cycle. The lyophilization cycle opted was freezing at a temperature of -55°C with annealing step at -22°C by which the reconstitution time was significantly reduced. The drying was performed at below - 25°C while maintaining a chamber pressure of 300 mTorr. The complete removal of non-aqueous solvents was achieved by retaining water within the system. The presence of cyclophosphamide monohydrate was confirmed using X-ray diffraction (XRD). The reduction of lyophilization process time was established by conducting mass transfer tests and evaluating the physicochemical properties of the pharmaceutical product. Using non-aqueous solvents for freeze-drying cyclophosphamide is a viable option, and this study provides significant knowledge for the advancement of future generic pharmaceuticals.

Association of gastric myotomy length in peroral endoscopic myotomy (POEM) with gastro-esophageal junction distensibility measured by Endoluminal Functional Lumen Imaging Probe (EndoFLIP).

Endoluminal Functional Lumen Imaging Probe (EndoFLIP) is a device that measures gastro-esophageal junction (GEJ) distensibility. However, it is not demonstrated that GEJ distensibility increases proportionally with varying gastric myotomy length in peroral endoscopic myotomy (POEM). This study aimed to investigate the association between gastric myotomy length in POEM and intraoperative EndoFLIP findings. This single-center, retrospective cohort study included patients who underwent POEM with intraoperative EndoFLIP from December 2019 to January 2023. Using EndoFLIP, minimal balloon diameter and its distensibility index (DI) were measured pre- and post-myotomy. Primary and secondary outcomes were the post-myotomy EndoFLIP findings at 30ml and 40ml volume fills. The study included 44 patients (mean age 53.1years, 50% female). Chicago classification included achalasia type I (39%), II (41%), III (9%), hypercontractile esophagus (2%), and EGJOO (9%). The mean esophageal myotomy length was 7.5 ± 2.2cm and gastric myotomy was 2.1 ± 0.6cm. Simple linear regression analyses indicated that for each 1cm increase in gastric myotomy length, the DI at 30ml volume fill was estimated to increase by 2.0mm2/mmHg (p < 0.05, R2 = 0.41), the minimal diameter at 30ml volume fill was estimated to increase by 2.4mm (p < 0.05, R2 = 0.48), and the minimal diameter at 40ml volume fill was estimated to increase by 1.3mm (p < 0.05, R2 = 0.09). This study demonstrates a significant linear relationship between gastric myotomy length and GEJ distensibility measured by EndoFLIP during POEM. These findings may be useful in clinical practice by enabling EndoFLIP to help calibrate a desired gastric myotomy length to achieve optimal DI and minimal diameter.

The influence of thermal radiation during microwave-assisted freeze-drying of pharmaceutical unit doses

New drying technologies for biologicals have recently been developed to accelerate the time-consuming batch freeze-drying (BFD) process. Among others, microwave-assisted freeze-drying (MFD) has been suggested as a faster and more effective drying technology. In this study, MFD cycles with the microwave radiation switched on and off were performed to assess the contribution of the microwave radiation to drying acceleration. It was found that thermal radiation emitted by the drying chamber walls was predominantly accelerating the drying of monodose placebos rather than microwave radiation. The combination of ultra-low chamber pressure, high thermal heat transfer and a short primary-to-secondary phase transition reduces drying times by more than 80 % compared to conventional BFD. In a second step, a design of experiment approach was used to assess the effect of thermal radiation versus microwave radiation and their combination, together with dosage properties such as fill volume and excipient concentration upon drying rate. The outcome showed the importance of high fill volume and high excipient concentration for an effective microwave contribution to the drying rate. Nevertheless, the drying acceleration for small pharmaceutical dosages with restricted solutes was mainly driven by thermal radiation rather than 2.45 GHz microwave radiation. The inability of ice to convert microwave energy into heat hampers the potential use of microwave freeze-drying for single-dose vaccines.

Stability of intravenous medicines – evidence of maximum temperature reached in both summer and winter within soft shell elastomeric pumps

ObjectiveElastomeric devices or pumps are a valuable tool to deliver outpatient parenteral therapy and have been used for administration of chemotherapy, antibiotics and pain medication. A key determinant of effective...

An Introduction to Ventra: A Programmable Abdominal Phantom for Training, Educational, Research, and Development Purposes.

Intra-abdominal pressure (IAP) is a critical parameter in the care of critically ill patients, as elevated IAP can lead to reduced cardiac output and organ perfusion, potentially resulting in multiple organ dysfunction and failure. The current gold standard for measuring IAP is an indirect technique via the bladder. According to the Abdominal Compartment Society's Guidelines, new measurement methods/devices for IAP must be validated against the gold standard. This study introduces Ventra, an abdominal phantom designed to simulate different IAP levels, abdominal compliance, respiration-related IAP variations, and bladder dynamics. Ventra aims to facilitate the development and validation of new IAP measurement devices while reducing reliance on animal and cadaveric studies. Additionally, it offers potential applications in training and education for biomedical engineering students. This study provides a thorough explanation on the phantom's design and fabrication, which provides a low-cost solution for advancing IAP measurement research and education. The design concept, technical aspects, and a series of validation experiments determining whether Ventra is a suitable tool for future research are presented in this study. Ventra's performance was evaluated through a series of validation tests using a pressure gauge and two intra-gastric (Spiegelberg and CiMON) and two intra-bladder (Accuryn and TraumaGuard) pressure measurement devices. The mean and standard deviation of IAP recordings by each device were investigated. Bland-Altman analysis was used to evaluate bias, precision, limits of agreement, and percentage error for each system. Concordance analysis was performed to assess the ability of Ventra in tracking IAP changes. The phantom demonstrated excellent agreement with reference pressure measurements, showing an average bias of 0.11 ± 0.49 mmHg. A concordance coefficient of 100% was observed for the phantom as well. Ventra accurately simulated different abdominal compliances, with higher IAP values resulting in lower compliance. Abdominal volume changes showed a bias of 0.08 ± 0.07 L/min, and bladder fill volume measurements showed an average difference of 0.90 ± 4.33 mL for volumes ranging from 50 to 500 mL. The validation results were in agreement with the research guidelines of the world abdominal society. Ventra is a reliable tool that will facilitate the development and validation of new IAP measurement devices. It is an effective educational tool for biomedical engineering students as well.

Variations in provider practices in remote patient monitoring on peritoneal dialysis in the USA and Canada.

Automation has allowed clinicians to program PD treatment parameters, all while obtaining extensive individual treatment data. This data populates in a centralized online platform shortly after PD treatment completion. Individual treatment data available to providers includes patients' vital signs, alarms, bypasses, prescribed PD treatment, actual treatment length, individual cycle fill volumes, ultrafiltration volumes, as well as fill, dwell, and drain times. However, there is no guidance about how often or if this data should be assessed by the clinical team members. We set out to determine current practice patterns by surveying members of the home dialysis team managing PD patients across the United States and Canada. A total of 127 providers completed the survey. While 91% of respondents reported having access to a remote monitoring platform, only 31% reported having a standardized protocol for data monitoring. Rating their perceived importance of having a standard protocol for remote data monitoring, on a scale of 0 (not important at all) to 10 (extremely important), the average response was 8 (physicians 7; nurses 9). Most nurses reported reviewing the data multiple times per week, whereas most physicians reported viewing the data only during regular/monthly visits. Although most of the providers who responded have access to remote monitoring data and feel that regular review is important, the degree of its utilization is variable, and the way in which the information is used is not commonly protocolized. Working to standardize data interpretation, testing algorithms, and educating providers to help process and present the data are important next steps.

Anti-slosh effect of baffle configurations and air pressure on liquid sloshing in partially filled tank trucks

Abstract The phenomenon of liquid sloshing inside partially filled tank trucks adversely affects the stability of the tanktrucks. In order to mitigate the negative effects of liquid sloshing inside the tank, this study proposes several baffle configurations and investigates their anti-slosh effect on liquid sloshing. First, a numerical model of liquid sloshing is established. Then, the effectiveness of the numerical model is validated by comparing the results of free surface deformation, wall pressure, and sloshing frequency obtained from simulations and experiments under identical conditions. During the research process, it was found that the air pressure formed in locally sealed spaces within the tank also plays a positive role in suppressing liquid sloshing. The research results indicate that, under low fill volumes, baffles fixed at the bottom of the tank are more effective in suppressing liquid sloshing inside the tank, while under high fill volumes, baffles fixed at the top of the tank are more effective. Considering the tank’s airtightness, the air pressure formed in locally sealed spaces within the tank plays an important role in suppressing liquid sloshing when baffles are fixed at the top of the tank and the fill volume is high.&amp;#xD;

Safety Profile Comparison of 2 Smooth Tissue Expander Types: Artoura and CPX4.

With the recent transition to smooth tissue expanders (TEs), functional differences between TE subtypes have not been fully elucidated. This study evaluated the differences in TE characteristics and complications between 2 commonly used Mentor smooth TE models, Artoura and CPX4. A retrospective review of patients who received either smooth Mentor Artoura or CPX4 TE from 2012 to 2022 was conducted. Demographic data, perioperative information, pain scores, TE variables, cancer characteristics, and complications were collected. A multivariate analysis was used to evaluate the relationship between TE subtype and complications while controlling for demographic, TE characteristics, radiation, and chemotherapy exposure. During the study period, 62 smooth Artoura TEs and 79 smooth CPX4 TEs were used. Patients who received CPX4 smooth implants tended to be older (51.09 vs 46.18 years old, P = 0.02) and have a higher body mass index (28.66 vs 23.50 kg/m 2 , P < 0.001). There were no differences among patient comorbidities. CPX4 required on average a greater total fill volume (422.23 vs 348.07 mL, P = 0.01) and had a greater drain duration (16.91 vs 14.33 days, P = 0.05). There were no differences in TE plane placement between Artoura and CPX4. Additionally, there were no differences in complication rates, including infection, hematomas, seromas, wound breakdown, TE replacement, and capsular contracture. When controlling for body mass index, diabetes, TE plane placement, acellular dermal matrix use, radiation exposure, and chemotherapy, there was no association between TE subtype and any individual complication. Differences in total fill volume and drain duration were significantly different between Mentor Artoura and CPX4 implants, which may influence TE subtype selection. However, Artoura and CPX4 have excellent and equivalent safety profiles with similar complication rates, even when controlling for demographic and TE characteristics.

Effects of Cholecystokinin on Esophageal Motor Response to Distension in Asymptomatic Volunteers.

Cholecystokinin (CCK) administration has been shown to reduce lower esophageal sphincter (LES) pressure in normal subjects in manometric studies. Functional luminal imaging probe (FLIP) panometry offers a method to assess esophageal motility in response to sustained distension though mechanisms related to this response remain unexplored. The aim of this study is to evaluate the effect of CCK-8 on the esophageal response to distension in asymptomatic volunteers using FLIP. Esophageal response to distension was studied in 7 asymptomatic volunteers (mean age ± SD [27 ± 2]; 86% female) before and after CCK-8 administration in a crossover study design. During sedated endoscopy, FLIP was performed twice with CCK-8 administered via intravenous push in one of 2 protocols: during filling (n = 4) or during emptying (n = 3). Esophagogastric junction distensibility index (EGJ-DI) at 60 mL fill volume and esophageal body contractile response patterns were analyzed. During the baseline FLIP study, all subjects had a contractile response with repetitive antegrade contractions both before and after CCK-8 administration. However, a sustained LES contraction or a sustained occluding contraction with esophageal shortening was observed in all subjects in the filling protocol, but in none during the emptying protocol. EGJ-DI was similar before and after CCK-8 during both filling (4.7 ± 1.9 mm2/mmHg vs 4.3 ± 1.8 mm2/mmHg) and emptying protocol (7.5 ± 1.4 mm2/mmHg vs 6.9 ± 0.6 mm2/mmHg). While EGJ-DI appeared unaffected by CCK-8 administration in asymptomatic volunteers, CCK induced spastic-reactive contractions of the LES during distention suggesting that exogenous CCK interferes with normal LES relaxation during secondary peristalsis.

Ultrafiltration Patterns during Automated Peritoneal Dialysis: Findings and Insights to Peritoneal Physiology.

With the growing use of automated peritoneal dialysis (APD), it is important to improve our knowledge of the clinical patterns and physiology of APD treatment sessions. The ultrafiltration (UF) achieved during each cycle of an APD treatment is assumed to be relatively linear if the delivered prescription is the same. We set out to determine if that is indeed the case. Single-center, cross-sectional study of prevalent PD patients. All adult APD patients (> 18 years of age), who had been on PD for >3 months, and >3 months on APD were included. Continuous ambulatory PD patients or those with peritonitis within 3 months of the consent date were excluded. Individual treatment data from 7 consecutive APD treatment sessions with consistent dialysate composition for each cycler exchange were collected for each subject. Thirty-nine subjects met the inclusion criteria and were enrolled. The probability of yielding a positive UF was 48.9% for cycle 1, rising to 90.5% by cycle 6. Adjusting for average dextrose concentration, dwell time, fill volume, solute transfer rate, and number of cycles, we observed that cycles 2 through 6 achieved progressively higher UF volumes than cycle 1 (p < 0.001). The first and last cycles demonstrated significantly different cycle UF volumes compared to a middle cycle (-230 ml and 277 ml, respectively, p < 0.001). We observed a consistent increase in UF volumes achieved per cycle over the course of an APD treatment session with numerous clinical and physiologic implications. This provides the foundation for future studies investigating peritoneal inter-cycle variations and membrane physiology.

A Holistic Approach for Fill volume Variability Evaluation and Control with Statistical Tool.

Vial and syringe filling by peristaltic pump has been widely implemented by contract manufacturing organizations and biopharmaceutical companies. Fill volume is commonly considered as critical quality attribute related in aseptic filling process and the variation needs to be well controlled to guarantee the safety, efficacy and consistency of drug products. However, the criteria for justifying the filling variation and underlying mechanisms that affect the variability are not fully revealed quantitatively in the literatures. This study selected filling accuracy, filling process capability and filling precision as three criteria for evaluating the filling process performance with four statistical indexes: Relative Error Mean, Critical Control Limit (Cpk ≥ 1.33), Relative Standard Deviation and Relative Moving Range Mean. The impact of liquid properties, pump tubing sizes and pump settings on above indexes were investigated using a bench-top system with a peristatic pump and a high-precision balance. The results showed that the viscosity, target fill volume, pump tubing size, pump speed, acceleration/deceleration rate and suck-back had statistical significance on the fill volume variability. Definitive Screening Design was further applied to clarify and visualize the priorities and interaction impact of above factors on fill volume variability. Stepwise approach for fill volume variability optimization and control based on predictive models was established and verified for drug product solution with viscosity between 1-23 cp and target fill volume between 0.2-2.0 mL.

Performance improvement of novel latent thermal energy storage system with two-layer metal foam porosities

A 2D numerical analysis was conducted to examine the melting performance of a shell-and-tube-type phase change material with a two-layer copper foam having higher and lower porosity levels. The design parameters for these two layers of metal foam consisted of three different volume fill ratios (VFR) (30 %/70 %, 50 %/50 %, and 70 %/30 %) and three different shapes (circular, semi-circular, and elliptical) for the lower porosity layer. The results showed that a semicircular-shaped low porosity layer with a 30 % VFR had the least melting time of 475 s. When the VFR increased to 50 %, the elliptical and circular shapes had the least melting time of 394 s. However, at a VFR of 70 %, only the elliptical shape had the least melting time of 323 s. Furthermore, the results were compared with the uniform porosity metal foam system, and deduced that the two-layer system did not always have the lower melting time compared with that of the uniform porosity system because it depended on the VFR and shape of the different porosities filled in the different layers. Additionally, for an average porosity of the metal foam, an optimal combination of two different porosities was observed for the melting performance.

The SAEORA Flap for Prosthetic Breast Reconstruction: A Novel Flap Design without the Use of Acellular Dermal Matrices.

The gold standard for implant-based breast reconstruction uses acellular dermal matrices (ADMs). They provide improved inferolateral pole coverage, reduced capsular contracture rates, and increased primary expander fill volumes. However, ADMs are costly and have been associated with increased rates of postoperative infection, seroma, hematoma, implant malposition, and mastectomy flap necrosis (MFN). This study describes a novel autologous flap without the need of ADM, the serratus anterior external oblique rectus abdominis (SAEORA) flap, as an alternative in prosthetic-based breast reconstruction. A retrospective study was conducted on all patients who underwent SAEORA flap breast reconstruction by a single surgeon between January 1, 2013 and May 31, 2020 at a single institution. Patient demographics, diagnosis, treatment, tissue expander (TE) volume, implant size, complications, and results were assessed. Forty-seven patients underwent 78 SAEORA flaps. Sixty-two had TEs placed, and 14 were direct-to-implant. Mean body mass index was 23.1 kg per m². Median primary TE fill volume was 150 mL, and final implant volume average was 450 mL. Mean follow-up was 14.5 months. Complications included infection/cellulitis (7.9%), seroma (6.6%), hematoma (5.2%), and MFN (7.9%). The SAEORA flap is a novel autologous flap and is a viable option for prosthetic-based breast reconstruction, with an acceptable complication profile relative to ADM-based reconstructions. Additionally, SAEORA is MFN-resistant and has been used effectively in salvage of exposed implants or ADM, and in double-bubble deformity correction.

Periareolar Skin-Sparing Mastectomy and Immediate Implant-Based Reconstruction

Introduction Skin-sparing mastectomy (SSM) is often used when tumor location prohibits performing a nipple-sparing mastectomy (NSM). We examined a square excision of the nipple-areolar complex (NAC) and an X-shaped purse string closure after implant-based reconstruction. Methods A retrospective review was performed on patients undergoing periareolar SSM and immediate implant-based reconstruction from January 2015 through December 2022, specifically identifying those patients who had square NAC excision and skin closure. Results Twenty-nine patients met the inclusion criteria. They underwent 54 periareolar SSM and immediate implant-based reconstruction (bilateral 25, unilateral 4). Indications for surgery were cancer (30) and prophylactic (24; 2 patients had bilateral cancer). Reconstructive methods included tissue expander (TE) (36 [66.7%]) and direct-to-implant (DTI) (18 [33.3%]). The mean mastectomy weights and final implant sizes were similar between the 2 groups. Overall wound complications occurred in 13 (24.1%) of the breasts: mastectomy skin flap necrosis (MSFN; 10 [18.5%]) and infection (3 [5.6%]). Reconstructive failure occurred in 3 cases: TE, 1 (infection); DTI, 2 (MSFN/exposure). MSFN by reconstructive method: TE, 4 (11.1%); DTI, 6 (33.3%) (P = 0.05, comparing MSFN rates between TE and DTI methods). The mean initial TE fill volume was 247.1 cc; mean implant size in the DTI group was 417.8 cc (P &lt; 0.0001). Conclusions The square NAC excision and closure can minimize the surgical incision in implant reconstruction. Two-stage TE reconstruction permits lower initial fill volumes, which reduces the risk of MSFN after box to X closure of SSM and implant-based reconstruction. It is useful in small- to moderate-sized breasts with mild ptosis in patients who are not candidates for NSM.