Location Of Perforation Research Articles

Clinical Outcomes of Endoscopic Butterfly Inlay Cartilage Myringoplasty.

To review a 3-year case series of endoscopic butterfly inlay cartilage myringoplasty performed by a single surgeon (W.S.K.) and analyze the clinical surgical outcomes. Retrospective study. Tertiary care academic center. We enrolled 60 ears with tympanic membrane (TM) perforation, receiving endoscopic inlay butterfly myringoplasty between 2019 and 2022. We reviewed patients' demographics, size and location of TM perforation, operation time, complications, and postoperative pain evaluated by the numerical rating scale (NRS). We analyzed the graft uptake success rate in 5 weeks and the perforation closure rate in 4 months after surgery. We also compared the air-bone gap (ABG) before and after the surgery. Among the 60 ears included, the mean age was 57.0 years, and 78.3% (47 of 60) had small perforations. The average operation time was 48.9 ± 11.5 minutes, and the postoperative NRS was 2.0 ± 1.6. The immediate graft uptake success rate evaluated at postoperative 5 weeks was 96.7% (58 of 60), with myringitis occurring in three ears. Except for 11 patients lost to follow-up, the perforation closure rate evaluated at postoperative 4 months was 100% (49 of 49). The mean ABG significantly improved from preoperative status (8.87 ± 5.51 dB HL) to postoperative 4 months (6.22 ± 6.03 dB HL) ( p = 0.019). A single surgeon's success rate for endoscopic butterfly inlay cartilage myringoplasty was almost 100%. This surgical procedure is safe and effective, with a high graft success rate.

The Analysis of Permeability Influence on CO2 Plume based on Reservoir Simulation

Abstract Permeability is critical in site characterization and geoscience studies for carbon capture and storage projects. There is significant uncertainty of CO2 movement in the subsurface caused by permeability. This study aims to analyze the influence of permeability on the movement of CO2 plumes using a synthetic single-porosity model based on reservoir simulation. By simplifying geomechanics, employing tornado experimental design, as well as utilizing Pearson and Spearman correlations from 30,000 neural network proxy models based on Latin Hypercube and Monte Carlo experimental design, this research successfully explains the impact of permeability on CO2 movement. The reservoir can withstand pressures up to 6500 psi without rock failure. The total CO2 injection with a 90% probability is ∼1.3 TSCF equivalent, with an injection rate of 30 MMSCFD, optimized for a duration of 120 years. Initially, the CO2 movement tends to be upward during injection due to gravitational effects, but over time, it tends to move laterally. Vertical permeability exhibits a negative correlation with total CO2 injection, lateral distribution of CO2 plumes, and CO2 solubility in water. On the other hand, horizontal permeability shows a positive correlation with total CO2 injection. Factors such as perforation location and layer thickness also influence the extent of permeability’s role. However, the lateral and vertical movement of CO2 in this study has not been fully identified, and more complex quantification formulas are needed in commercial simulators. Despite the limitations in data and computational resources, this research successfully explains the movement of CO2 plumes and highlights the importance of other factors such as porosity, perforation location, layer thickness, among others. The recommendations of this study include the use of more complex quantification formulas to model the movement of CO2 plumes, along with increasing the complexity of the model.

Effectiveness of the proximal medial branch in DIEP flaps for breast reconstruction using Hartrampf zone IV

BackgroundWhen performing breast reconstruction using a deep inferior epigastric artery perforator (DIEP) flap, including Hartrampf zone IV, the bipedicled DIEP flap has been argued to be necessary to ensure stable perfusion. However, a proximal medial branch (PMB), which is the most proximal perforator of the deep inferior epigastric artery, may make it possible to obtain adequate perfusion in a unilateral DIEP flap. This study aimed to clarify the detailed anatomical characteristics of PMB and its potential clinical application in breast reconstruction. MethodsThis retrospective study was conducted on breast reconstruction using the DIEP flap between May 2020 and July 2023. Data on PMB anatomy were collected from preoperative contrast-enhanced computed tomography angiography, and contralateral perfusion of the flap was estimated using intraoperative indocyanine green angiography. ResultsThe PMB was present in approximately 85% of cases, arising near the lateral border of the rectus abdominis, branching caudomedially in over half of the cases, and perforating 2.3cm laterally and 8.8cm caudally on average from the umbilicus. The average perfusion area of both zones II and IV significantly expanded to 96.5% and 74.2%, respectively, when the PMB was included in the DIEP flap, and 9 of 22 cases showed contrast extending to the entire zone IV. ConclusionsThe use of the DIEP flap with PMB is a good option for substantial-volume breast reconstruction. When utilizing the PMB, it is important to consider its specific anatomy, location of the main perforator, and pedicle length.

Perfusion area versus volume of the DIEP flap: A multivariable analysis of perforator and flap characteristics for estimation of perfusion area and volume

BackgroundThe extent of perfusion of a deep inferior epigastric artery perforator (DIEP) flap is a primary concern for surgeons. This study aimed to determine whether the flap area or volume can be estimated using perforator and flap characteristics. MethodsIntraoperative flap perfusion was assessed using indocyanine green angiography in patients who underwent DIEP flap breast reconstruction between November 2018 and February 2023. The area perfused by a single dominant perforator was delineated on the surface of the flap and measured using the ImageJ software. Multiple linear regression analysis was conducted to estimate the ‘perfusion ratio,’ defined as the perfused area divided by the total flap area. Potential predictor variables included flap size (cm2), flap thickness (mm), perforator diameter (mm), perforator rows (medial/lateral), vertical location of perforator (at or above/below the umbilicus), and perforator eccentricity (vertical distance from upper flap margin to perforator, cm). ResultsIn total, 101 patients were included in this analysis. The mean ‘perfusion ratio’ was 67.8% ± 11.5%, predicted by perforator diameter (p = 0.022) and vertical location below umbilicus (p < 0.001) with positive correlations and negatively correlated with flap thickness (p = 0.003) in the multivariable analysis. Both perfusion area and weight were predicted by perforator diameter, vertical location of perforator, flap size, and flap thickness (p < 0.001). The coefficient of determination (adjusted R2) for prediction of perfusion weight was higher than that for the perfusion area (75.5% vs. 69.4%). ConclusionsFlap volume, rather than area, is determined by a perforator of a given diameter and location.

Division versus de-epithelialization of fibula osteocutaneous flap for composite oromandibular defects: A propensity score-matched analysis

BackgroundDifferent fibula osteocutaneous free flap (FOCFF) configurations have been described with a double-skin paddle (DSP) to address composite through-and-through oromandibular defects: division of the skin paddle using different perforators (div-FOCFF) or a de-epithelialized DSP FOCFF (deEpi-FOCFF). This study aimed to compare the surgical outcomes using these two methods (deEpi-FOCFF/div-FOCFF). MethodsPatients who underwent segmental mandibulectomy and reconstruction with a DSP FOCFF between 2011 and 2014 were included. We compared postoperative outcomes of patients undergoing reconstruction with deEpi-FOCFF versus div-FOCFF implementing propensity score matching. ResultsOf the 245 patients, 156 cases (78 pairs) were 1:1 matched. Demographic and oncologic variables were comparable between groups. The average age was 57.68 years. A higher number of perforators per flap was evident in the div-FOCFF group (p < 0.001). The deEpi-FOCFF group exhibited a higher total flap loss rate when compared to the div-FOCFF group (15 % versus 5 % p = 0.03). On multivariate analysis, number of perforators per flap (OR 0.31, p = 0.02), using the deEpi-FOCFF (OR 3.88, p = 0.03), and an increased reconstructive time (OR 1.01, p = 0.01) independently affected the likelihood of free flap failure. ConclusionIf the number and location of perforators are optimal, div-FOCFF improves reconstructive outcomes for composite oromandibular defects versus the deEpi-FOCFF.

TFL Perforator Flap Complementing and Completing the ALT-AMT Flap Axis.

Background Anterolateral thigh (ALT) flap is the most common soft tissue flap used for microvascular reconstruction of head and neck. Its harvest is associated with some unpredictability due to variability in perforator characteristics, injury or unfavorable configuration for complex defects. Anteromedial thigh (AMT) flap is an option, but the low incidence and thickness restrict its utility. Tensor fascia lata (TFL) perforator (TFLP) flap is an excellent option to complement ALT. Its perforator is consistent, robust, in vicinity, and lends itself with the ALT perforator. Methods This study was an analysis of 29 cases with a free flap for head neck reconstruction with an element of TFLP flap from July 2017 to May 2021. Results All cases were primarily planned for an ALT reconstruction. There was absence of the ALT perforator in 16 cases but a sizable TFL perforator was available. In 13 cases, the complex defect warranted use of both ALT plus TFL in a conjoint (5), chimeric (5), and multiple (3) free flaps manner. Most common perforator location was septocutaneous between the TFL and gluteus medius. There was complete flap loss in two cases and partial necrosis in two. No adjuvant therapy was delayed. Conclusion TFLP can reliably complement the ALT/AMT axis. Chimeric ALT-TFL can be harvested for large, complex, multicomponent, and multidimensional defects.

Local Perineal Capillary Perforator Flaps: A Minimally Invasive Technique for the Correction of Vulvar Stenosis.

Vulvar stenosis is a debilitating condition that compromises sexual function, urination, and the ability to undergo gynecological examinations. The purpose of this study is to describe the technique of capillary perforator perineal flaps (CPPF) for the correction of vulvar stenosis. We retrospectively examined patients with vulvar stenosis treated through surgical separation and reconstruction with CPPF. The procedure involved vulvar separation with the creation of a subsequent defect, repaired using a flap, harvested laterally to the labia majora including a capillary perforator and transferred through a subcutaneous tunnel to repair the vulvar defect. The functional outcome was evaluated with the Bradford scale, comparing the preoperative and postoperative scores using the Student's t-test. thirteen patients were included, three with stenosis following treatment for vulvar cancer and ten due to lichen sclerosus. In total, we analyzed 29 flaps, with an average size of 15.6 cm2. We always included just one perforator in the flap and no postoperative complications. Stenosis was resolved in all patients, with no recurrences one year after the surgery. The preoperative average severity of the stenosis was 2.3 + 0.6, reducing to 0.3 + 0.4 post-intervention, indicating a significant improvement (p < 0.01). CPPF has proven to be a quick and safe method for the reconstruction of vulvar stenosis.

Suture Packaging as a Marker for Intraoperative Image Alignment in Augmented Reality on Mobile Devices.

Preoperative vascular imaging has become standard practice in the planning of microsurgical breast reconstruction. Currently, translating perforator locations from radiological findings to a patient's abdomen is often not easy or intuitive. Techniques using three-dimensional printing or patient-specific guides have been introduced to superimpose anatomy onto the abdomen for reference. Augmented and mixed reality is currently actively investigated for perforator mapping by superimposing virtual models directly onto the patient. Most techniques have found only limited adoption due to complexity and price. Additionally, a critical step is aligning virtual models to patients. We propose repurposing suture packaging as an image tracking marker. Tracking markers allow quick and easy alignment of virtual models to the individual patient's anatomy. Current techniques are often complicated or expensive and limit intraoperative use of augmented reality models. Suture packs are sterile, readily available, and can be used to align abdominal models on the patients. Using an iPad, the augmented reality models automatically align in the correct position by using a suture pack as a tracking marker. Given the ubiquity of iPads, the combination of these devices with readily available suture packs will predictably lower the barrier to entry and utilization of this technology. Here, our workflow is presented along with its intraoperative utilization. Additionally, we investigated the accuracy of this technology.

Identification of peroneal artery perforators using non-contrast-enhanced T2prep multi-shot gradient echo planar imaging MRA.

The purpose of this study was to investigate the spatial resolution of non-contrast-enhanced (CE) T2prep multi-shot gradient echo planar imaging (MSG-EPI) magnetic resonance angiography (MRA) required to identify peroneal artery perforators and demonstrate its effectiveness in preoperative simulation. Twenty-six legs of 13 volunteers were scanned using non-CE T2prep MSG-EPI-MRA at three spatial resolutions: 1.0-, 0.8-, and 0.6-mm isotropic voxels. The location and number of peroneal artery perforators that could be candidates for free fibula flaps were identified by consensus among three plastic surgeons. Surgeons distinguished between septocutaneous and musculocutaneous perforators using MRA, and confirmed the accuracy of their presence and identification using ultrasonography (US). The ability to detect hypoplasia or stenosis of the anterior tibial, posterior tibial, and peroneal arteries was evaluated by confirming the consistency between the MRA and US results. The number of cutaneous perforators identified using MRA and confirmed using US was 39, 51, and 52 at each respective resolution. The discrimination accuracies between septocutaneous and musculocutaneous perforators were 92.3%, 96.1%, and 96.2%. The number of identified septocutaneous perforators was 1.3 ± 0.6, 1.6 ± 0.8, and 1.7 ± 0.8 at 1.0-, 0.8-, and 0.6-mm data, respectively. All the MRA results, including hypoplasia and stenosis, were consistent with the US results. Non-CE T2prep MSG-EPI-MRA with a spatial resolution of 0.8mm or less shows promise for identifying septocutaneous perforators of the peroneal artery, suggesting its potential as an alternative to conventional imaging methods for the preoperative planning of free fibula osteocutaneous flap transfers.

Identifying perforation locations for hydraulic fracturing treatment in deep and tight sandstone gas reservoirs

Fracture initiation has been a challenging issue for fracturing deep and tight gas reservoirs, which generally requires a high breakdown pressure for hydraulic fracturing treatment. In this situation, fluid injections frequently have to terminate at the very beginning. Toward predicting and solving this issue, a novel fracturing system for deep and tight sandstone gas reservoirs was developed. The key components of the fracturing system and some criterion will be introduced, which can be used to optimize the ideal perforation locations along the landing part and select the right perforation strategy accordingly. The main components of the fracturing system include: (1) evaluating the log-based diagenetic rock typing and flow index; (2) 1D mechanical earth model; (3) calculating the breakdown pressure envelope along the well trajectory of the landing part; (4) calculating the optimal perforation directions along the landing part; (5) select the first set of perforation locations based on the log-based diagenetic rock typing and flow index; (6) narrowing down the first set of perforation locations to a second set of perforation locations based on the breakdown pressure envelope; (7) determining a perforation strategy based on breakdown pressure envelope and wellhead pressure safety limit in the second set of perforation locations. The computational framework to calculate the breakdown pressure envelope and optimal perforation directions is applicable to arbitrary well trajectory. The fracturing system has been used to provide pre-fracturing suggestions for wells landed in deep and tight sandstone reservoirs, which is very efficient for identifying locations with good rock typing and relatively low breakdown pressure. Also, it can indicate whether oriented perforation should be used further for alleviating breakdown issue. By taking these efforts and procedures, the fracturing success rate for deep and tight sandstone gas reservoirs can be improved, which has been verified in practice. Example studies from the field will be provided to demonstrate the fracturing system's performance and applicability.

Oncologic Staging Computed Tomography with IV Contrast Has Similar Efficacy to Dedicated Computed Tomography Angiography for Preoperative DIEP Flap Planning

Background: Due to variations in perforator vasculature, deep inferior epigastric artery perforator (DIEP) flap preoperative imaging can minimize operative time required to locate the most suitable perforators. Dedicated computed tomography angiography (CTA) has been the gold standard; however, many patients have already undergone a staging computed tomography (CT) per oncologic workup. The benefits from CTA may also be realized with a staging CT or CT with IV contrast. Methods: Ten patients who underwent DIEP flap reconstruction with staging CT and CTA within 3 years of one another were included in this study. Reviewers evaluated axial views of both imaging modalities separately to identify each visible perforator in reference to the pubic symphysis from the xiphoid to the pubic symphysis. An intraclass correlation coefficient (ICC) was used to determine agreement in location of perforators between the two imaging studies. Statistical analysis was performed using an ICC and Wilcoxon signed rank-tests. Results: The identified perforators within the patient cohort had an excellent correlation between their location on CT and CTA based upon ICC. The mean number of perforators identified in the CT group was 15.3 (SD 4.9) and in the CTA group was 18.8 (SD 6.4), which was not statistically different (P = 0.247). Conclusions: CT has similar efficacy in identifying number of perforators and perforator location to dedicated CTA for preoperative planning in DIEP flaps. This has the potential for decreased patient contrast and ionizing radiation exposure as well as improved patient and healthcare resource utilization.

Posterior Communicating Artery / Posterior Cerebral Artery

Thorough understanding of the vascular anatomy, including embryological development of vessels is important to safely perform endovascular procedures. The posterior cerebral and anterior choroidal arteries are embryologically complementary, which suggests a potential network. Numerous perforators originate from the posterior communicating and posterior cerebral arteries. The tuberothalamic artery arising from the posterior communicating artery and the thalamoperforating artery, which originates from the P1 segment of the posterior cerebral artery are clinically important because occlusion of these vessels can precipitate severe infarction. It is clinically important to be aware that the branching pattern of perforators differs based on the fusion type of the basilar tip. The balloon occlusion and Allcock test are useful to predict ischemic tolerance in cases of intentional artery occlusion. However, accurate prediction remains challenging, and a definitive evaluation method is unavailable. Flow disturbances in the cortical territory and local perforator impairment require close attention in cases of intentional artery occlusion.

Identifying Preoperative Clinical Characteristics of Unexpected Gastrointestinal Perforation in Infants-A Retrospective Cohort Study.

Infants presenting with unexpected pneumoperitoneum upon abdominal X-ray, indicating a gastrointestinal perforation (GIP), have a surgical emergency with potential morbidity and mortality. Preoperative determination of the location of perforation is challenging but will aid the surgeon in optimizing the surgical strategy, as colon perforations are more challenging than small bowel perforations. Therefore, the aim of this study is to provide an overview of preoperative patient characteristics, determine the differences between the small bowel and colon, and determine underlying causes in a cohort of infants with unexpected GIP. All infants (age ≤ 6 months) who presented at our center with unexpected pneumoperitoneum (no signs of pneumatosis before) undergoing surgery between 1996 and 2024 were retrospectively included. The differences between the location of perforation were analyzed using chi-squared and t-tests. Bonferroni correction was used to adjust for multiple tests. In total, 51 infants presented with unexpected pneumoperitoneum at our center, predominantly male (N = 36/51) and premature (N = 40/51). Among them, twenty-six had small bowel, twenty-two colon, and three stomach perforations. Prematurity (p = 0.001), birthweight < 1000 g (p = 0.001), respiratory support (p = 0.001), and lower median arterial pH levels (p = 0.001) were more present in patients with small bowel perforation compared with colon perforations. Pneumatosis intestinalis was more present in patients with colon perforation (p = 0.004). All patients with Hirschsprung disease and cystic fibrosis had colon perforation. The final diagnoses were mainly focal intestinal perforations (N = 27/51) and necrotizing enterocolitis (N = 9/51). Infants with unexpected GIP, birthweight < 1000 g, and prematurity have more risk for small bowel perforation. In case of colon perforation, additional screening (for Hirschsprung and cystic fibrosis) should be considered.

Diagnostic value of identifying location and amount of free gas in the abdominal cavity by multidetector computed tomography in patients with acute gastrointestinal perforation

Objective: To evaluate the relationships between the location and extent of diffusion of free intraperitoneal air by multi-slice spiral CT (MSCT) and between the location and size of acute gastrointestinal perforation. Methods: This was a descriptive case series. We examined abdominal CT images of 33 patients who were treated for intraoperatively confirmed gastrointestinal perforation (excluding appendiceal perforation) in the Department of General Surgery, Nanfang Hospital between January and September 2022. We identified five locations of intraperitoneal air: the subphrenic space, hepatic portal space, mid-abdominal wall, mesenteric space, and pelvic cavity. We allocated the 33 patients to an upper gastrointestinal perforation (n=23) and lower gastrointestinal perforation group (n=10) base on intraoperative findings and analyzed the relationships between the locations of free gas and of gastrointestinal perforation. Additionally, we established two models for analyzing the extent of diffusion of free gas in the abdominal cavity and constructed receiver operating characteristic (ROC) curves to analyze the relationships between the two models and the size of the gastrointestinal perforation. Results: In the upper gastrointestinal perforation group, free gas was located around the hepatic portal area in 91.3% (21/23) of patients: this is a significantly greater proportion than that found in the lower gastrointestinal perforation group (5/10) (P=0.016). In contrast, free gas was located in the mesenteric interspace in 8/10 patients in the lower gastrointestinal perforation group; this is a significantly greater proportion than was found in the upper gastrointestinal perforation group (8.7%, 2/23) (P<0.010). The sensitivity of diagnosis of upper gastrointestinal perforation base on the presence of hepatic portal free gas was 84.8% and the specificity 71.4%. Further, the sensitivity of diagnosis of lower gastrointestinal perforation base on the presence of mesenteric interspace free gas was 80.0% and the specificity 91.3%. The rates of presence of free gas in the subdiaphragmatic area, mid-abdominal wall, and pelvic cavity did not differ significantly between the two groups (all P>0.05). Receiver operating characteristic curves showed that when free gas was present in four or more of the studied locations in the abdominal cavity, the optimal cutoff for perforation diameter was 2 cm, the corresponding sensitivity 66.7%, and the specificity 100%, suggesting that abdominal free gas diffuses extensively when the diameter of the perforation is >2 cm. Another model revealed that when free gas is present in three or more of the studied locations, the optimal cutoff for perforation diameter is 1 cm, corresponding to a sensitivity of 91.7% and specificity of 76.2%; suggesting that free gas is relatively confined in the abdominal cavity when the diameter of the perforation is <1 cm. Conclusion: Identifying which of five locations in the abdominal cavity contains free intraperitoneal air by examining MSCT images can be used to assist in the diagnosis of the location and size of acute gastrointestinal perforations.

Study on Proppant Transport and Placement in Shale Gas Main Fractures

In this paper, based on the background of a deep shale reservoir, a solid–liquid two-phase flow model suitable for proppant and fracturing fluid flow was established based on the Euler method, and a large-scale fracture model was established. Based on field parameters, a proppant transport experiment was conducted. Then, on the basis of the experimental fracture model, proppant transport simulation under different influencing factors was carried out. The results show that the laboratory experiment was in good agreement with the simulated results. The process of proppant accumulation in fractures can be divided into three stages according to the characteristics of sand banks. The displacement mainly affects the sedimentation distance of the proppant in the first stage, and the viscosity of the fracturing fluid represents the strength of the fluid sand carrying performance. Compared with 40/70 mesh proppant, 70/140 mesh proppant is more easily fluidizable, the fracture width has less influence on proppant migration and placement, and the perforation location only affects the accumulation pattern at the fracture entrance, but has less influence on proppant placement in the remote well zone.

A Cadaveric Study on Perforator Anatomy of the Medial Sural Artery Perforator Flap.

Background The medial sural artery perforator (MSAP) flap was described by Cavadas et al in 2001. The aim of this study was to analyze the flap characteristics in the regional population and was planned as a cadaveric dissection study. Methods Thirty-three legs of fresh cadavers were studied for perforator characteristics, length, and origin of pedicle and skin paddle thickness. Observations were documented and analyzed. Results Seventeen right legs (51.5%) and sixteen left legs (48.5%) were studied. Twenty-five pedicles originated from popliteal artery (86.2%) and four (13.8%) from the common sural trunk. No perforators were seen in four legs. The mean number of perforators is 2 (0-6). The mean distance of perforator from midpoint of popliteal fossa was 10.7 cm (8-13 cm) and from posterior midline it was 3.2 cm. The mean size of the perforator was 1.1 ± 0.8 mm (0.8-1.5 mm). The mean pedicle length was 9.3 ± 1.3 cm. The mean flap thickness was 4.3 ± 0.7 mm (3.0-5.5 mm). There was no correlation for flap or perforator characteristics with side of leg. Conclusion This study concludes that MSAP is a good flap in terms of perforator characteristics, pedicle length, and flap thickness, when a medium sized thin flap with long pedicle is needed. The location of perforator on calf varies in different population. Being a perforator flap, anatomical variability is common and should be thought of while choosing this flap.

Algoritmo para la selección de colgajos perforantes perimamarios en reconstrucción inmediata poscirugía conservadora

Background: Chest wall perforator flaps are a good option for immediate breast reconstruction after conservative surgery. Objective: The aim of this study was to describe the clinical results of an algorithm for using chest wall perforator flaps for breast reconstruction after breast-conserving surgery for breast cancer. Material and methods: We conducted a descriptive and retrospective study. The information was retrieved from the medical records of the patients diagnosed with breast cancer who underwent breast-conserving surgery and required reconstruction using chest wall perforator flaps between January 2020 and March 2022. The indications included volume deficit, contour defect and asymmetry. The vascular pedicle of the flap was evaluated by color Doppler ultrasound in all cases, which allowed us to follow an algorithm for selecting the best flap option. Results: Twenty flaps were made in 19 patients. Mean age: 52 years ± 11 (range 30-76). There were no intraoperative complications. One patient required reoperation due to a hematoma with compression of the vascular pedicle of the flap with partial flap loss, and another flap presented superficial epidermolysis. There were no cases of complete flap loss. All the patients underwent postoperative radiation therapy without loss of volume or retractions. Mean follow-up was 15 months. At 6 months, patients rated the results as excellent, good, and fair in 7, 11, and 2 cases, respectively. Conclusion: The selection of local perforator flaps to correct breast defects after conservative surgery, using preoperative color Doppler ultrasound to identify the vascular pedicle and a specific algorithm, allowed us to obtain satisfactory aesthetic results without the need for alloplastic elements or subsequent revisions.

Variation-Difference Method of Calculation of Layered Rubber-Metal Vibration Isolators Used for Protection of Reinforced Concrete Buildings from Anthropogenic Vibration

In the modern construction complex of the city of Moscow for the protection of buildings and structures from man-made vibration arising from the movement of trains of rail transportation (subway trains, railroad lines and trams). To protect buildings and structures from anthropogenic vibration arising from the movement of rail transport trains (subway trains, railroad lines and streetcars), Moscow uses layered rubber-metal vibration isolators [1]. Most often, to determine their static and dynamic characteristics, the finite element method (FEM) is used, which makes it possible to determine all components of the stress-strain state and frequencies of free oscillations in the loaded state practically for any structural forms of isolators. However, for the most popular software packages that implement FEM, the problem of optimizing the structural shape of the vibration isolator still requires significant time expenditures for multiple changes of the finite element mesh, repeated setting of boundary conditions and implementation of a series of calculations. Only some of the software packages implementing the FEM solve optimization problems of the shape of the product being calculated, most often it is related to foreign software products with universal functionality. Variation-difference method (VDM) is the closest to the finite element method (FEM) in terms of its computational capabilities. It is possible to create program modules that repeatedly and automatically solve three-dimensional problems of elasticity theory taking into account the changed geometry of the vibration isolator: the dimensions of the product, the location of perforations within the rubber layers, as well as the thickness of the rubber layer and other parameters important for obtaining an effective technical solution for vibration isolation of buildings. Further, the article describes the method of implementation of the variational-difference method (VDM) as applied to the solution of the problem of determining the components of the stress-strain state inside a three-dimensional layered vibration isolator with perforations of different sizes having different locations relative to the contour of the vibration isolator, i.e., the solution of the problem of optimizing the three-dimensional shape of the vibration isolator is given.

The technique and application of individualized tympanic membrane flap in the repair of tympanic membrane under endoscopy ear surgery

Objective:To investigate the technique of personalized flap making under otoscopy and its clinical application. Methods:The clinical data of patients who underwent 301 Military Hospital myringoplasty in the Department of otoendoscopic surgery, Department of Otorhinolaryngology, head and neck surgery, Department of Otorhinolaryngology, from October 2022 to 2023 August were analyzed retrospectively, all enrolled patients were performed independently by the same skilled otoendoscopic surgeon. The patients' general condition, medical history, tympanic membrane perforation scope, perforation size, need for tympanic cavity exploration, thickness of skin flap, tympanic cavity lesion scope, skin flap making method and postoperative rehabilitation were collected. Results:Many factors such as the location of tympanic membrane perforation, the thickness of the skin flap, the degree of curvature or stricture of the ear canal and the extent of the lesion in the tympanic cavity should be considered in the manufacture of the individualized tympanic membrane skin flap, the way of skin flap making does not affect the long-term postoperative rehabilitation, but it can effectively avoid unnecessary ear canal skin flap injury and improve the operation efficiency. Conclusion:Scientific flap fabrication is important for improving surgical efficiency and enhancing surgical confidence.

Local Flaps in Breast-Conserving Surgery in Early Breast Cancer Patients: Armamentarium for Breast Surgeon.

To describe the technique and outcome of local perforator arteries advancement flap in breast-conserving surgeries (BCS) in patient of early breast cancer as our initial experience and review of literature on it. Patients who underwent (BCS) with local perforator artery flap reconstruction were reviewed in terms of their clinical, surgical, and post-operative follow-up details after taking written and informed consent. We have described 4 patients of early breast cancer out of which one patient was post-NACT while 3 were for upfront BCS. We have performed LICAP in 2 patients, AICAP in 1 patient, and IMAP in one patient, depending on the location of primary tumors. None of the patients had any major or minor surgical complications in the post-operative period and drains were removed on post-operative day 2. All patients received post-operative radiotherapy and tolerated well without any loco-regional complications. Patients are in routine follow-up with cosmetic satisfaction without any local recurrence over 1year. The main advantages of pedicled perforator flaps are well-vascularized tissue, spares underlying muscle leading to lesser donor site morbidity like muscle function and seroma formation, easily reach the breast area with good match in terms of skin and subcutaneous tissue, faster recovery, and shorter learning curve in comparison to free flaps. Knowledge and skill about these flaps will help surgeon to give better surgical outcomes and satisfaction to patients.