Perivascular vital cells in the ablation center after multibipolar radiofrequency ablation in an in vivo porcine model

Multibipolar radiofrequency ablation (RFA) is an advanced ablation technique for early stage hepatocellular carcinoma and liver metastases. Vessel cooling in multibipolar RFA has not been systematically investigated. The objective of this study was to evaluate the presence of perivascular vital cells within the ablation zone after multibipolar RFA. Multibipolar RFA were performed in domestic pigs in vivo. Three internally cooled bipolar RFA applicators were used simultaneously. Three experimental settings were planned: (1) inter-applicator-distance: 15 mm; (2) inter-applicator-distance: 20 mm; (3) inter-applicator-distance: 20 mm with hepatic inflow occlusion (Pringle maneuver). A vitality staining was used to analyze liver cell vitality around all vessels in the ablation center with a diameter > 0.5 mm histologically. 771 vessels were identified. No vital tissue was seen around 423 out of 429 vessels (98.6%) situated within the central white zone. Vital cells could be observed around major hepatic vessels situated adjacent to the ablation center. Vessel diameter (> 3.0 mm; p < 0.05) and low vessel-to-ablation-center distance (< 0.2 mm; p < 0.05) were identified as risk factors for incomplete ablation adjacent to hepatic vessels. The vast majority of vessels, which were localized in the clinically relevant white zone, showed no vital perivascular cells, regardless of vessel diameter and vessel type. However, there was a risk of incomplete ablation around major hepatic vessels situated directly within the ablation center. A Pringle maneuver could avoid incomplete ablations.

Modern Views on the Treatment of Patients with Injuries of the Medial and Lateral Menisci of the Knee Joint (Literature Review)

Summary. We have analyzed the literature to determine the tactics of the knee menisci injury surgical treatment. It has been determined that the use of cellular technologies for suturing a damaged meniscus allows satisfactory results even in patients with ruptures in the avascular zones, despite the fact that partial meniscectomy is considered the "gold standard" of surgical treatment for ruptures in the “white” zone. It should be considered the advantages and disadvantages of different stitching techniques and the specific clinical and physical characteristics of each patient.

Quantitative Evaluation of Meniscal Healing Process of Degenerative Meniscus Lesions Treated with Hyaluronic Acid: A Clinical and MRI Study

Purpose: We aimed to evaluate clinical efficacy and healing effects of conservative management of degenerative meniscus lesions (DMLs) with a hyaluronic acid (HA) hydrogel. Methods: Patients were subjected to two HA injections two weeks apart. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Patient’s Global Assessment (PtGA) and Clinical Observer Global Assessment (CoGA) of the disease were assessed at baseline, 30, and 60 days after treatment. Short Form (36) Health Survey (SF-36) was assessed at baseline and 60 days after treatment. One year after treatment, patients were called to know whether any of them had undergone arthroscopic partial meniscectomy (APM). All patients underwent magnetic resonance imaging using a 1.5-T Magnetic Resonance Imaging (MRI) scanner (Siemens Aera), which included a T2 mapping pulse sequence with multiple echoes at baseline and 60 days after treatment. Results: 40 patients were enrolled. WOMAC score, physical function subscale, PtGA and CoGA, and SF-36 showed a statistically significant difference between baseline and follow-up. One year after treatment, only one patient had undergone APM. A decrease in the T2 measurement was detected in the posterior horn medial meniscus in 39% of cases in both the red and red–white zone, and in 60% of cases in the white zone; in the posterior horn lateral meniscus in 55% of cases in both the red and white zones, and in 65% of cases in the red–white zone. Only for the latter, there was a statistically significant difference between baseline and posttreatment T2 measurements. Conclusion: This study supports the use of HA in the conservative management of DML as it is clinically effective and enhances meniscus healing as demonstrated by T2 measurements. Moreover, it reduces the need for APM at 1-year follow-up.

Evaluation of Meniscal Tissue after Meniscal Repair Using Ultrahigh Field MRI

The study evaluates the meniscal tissue after primary meniscal suturing using 7-Tesla (T) magnetic resonance imaging with T2* mapping at 6 and 12 months after surgery to investigate the differences between repaired meniscal tissue and healthy meniscal tissue in the medial and lateral compartment. This prospective study included 11 patients (9m/2f) with a mean age of 30.6 years (standard deviation 9.0). Patients with a meniscal tear that was treated arthroscopically with meniscus suturing, using an all-inside technique, were included. All patients and seven healthy volunteers were imaged on a 7-T whole-body system. T2* mapping of the meniscus was applied on sagittal slices. Regions-of-interest were defined manually in the red and white zone of each medial and lateral meniscus to measure T2*-values. In the medial posterior and medial anterior horn similar T2*-values were measured in the red and white zone at 6- and 12-month follow-up. Compared with the control group higher T2*-values were found in the repaired medial meniscus. After 12-months T2*-values decreased to normal values in the anterior horn and remained elevated in the posterior horn. In the red zone of the lateral posterior horn a significant decrease in the T2*-values (from 8.2 milliseconds to 5.9 milliseconds) (p = 0.04), indicates successful repair; a tendency toward a decrease in the white zone between the 6 and 12 months follow-up was observed. In the red zone of the lateral anterior horn the T2*-values decreased significantly during follow-up and in the white zone of the lateral anterior horn T2*-values were comparable. In comparison to the control group higher T2*-values were measured at 6-months; however, the T2*-values showed comparable values in the repaired lateral meniscus after 12 months. The T2* mapping results of the current study indicated a better healing response of the red zone of the lateral posterior horn compared with the medial posterior horn.

Which Factors Increase the Risk of Reoperation After Meniscal Surgery in Children?

Background: Meniscal injuries in children can pose treatment challenges, as the meniscus must maintain its biomechanical function over a long lifetime while withstanding a high activity level. While the adult literature contains a plethora of studies regarding risk factors for failure of meniscal surgery, such reports are scarcer in children. Purpose: To determine the rate at which children undergoing meniscal surgery require subsequent reoperation as well as to define risk factors for reoperation in this population. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective institutional database of 907 first-time meniscal surgical procedures performed between 2000 and 2015 was reviewed. All patients were <18 years old. Demographic and intraoperative information was recorded, as were concurrent injuries or operations and subsequent procedures. Univariate analysis consisted of chi-square and independent-samples t tests. Multivariate logistic regression with purposeful selection was then performed to adjust for confounding factors. Results: The mean ± SD patient age was 13.2 ± 2.1 years, and 567 (63%) were male. The mean postoperative follow-up duration was 20.1 ± 10.1 months. Overall, 83 patients (9%) required repeat surgery at a mean of 23.2 months after the index operation. After adjustment for confounders in a multivariate model, meniscal repair resulted in 3.1-times higher odds of reoperation when compared with meniscectomy (95% CI, 1.2-8.3; P = .02), while white-white zone tears had 2.8-times lower odds of reoperation (95% CI, 1.01-7.7; P = .04) versus red-red and red-white zone tears. Conclusion: Approximately 9% of children undergoing meniscal surgery will require reoperation at a mean 23.2 months after the index operation. Repair carried approximately 3-times higher odds of reoperation than meniscectomy, while white-white zone tears had nearly 3-times lower odds of requiring repeat surgery when compared with tears in other zones.

Electrical heating properties of various electro-circuit patterns coated on cotton fabric using graphene/polymer composites

To investigate the electrical heating performance of two types of electro-circuit patterns, stripe-pattern (SP) and horseshoe-pattern (HP) types were designed by using graphene/poly(vinylidene fluoride- co-hexafluoropropylene) composites to fabricate electrical heating textiles for the inner layers of clothing and gloves to maintain body temperature. To confirm the electrical properties of the pattern shape and area of the coated circuit, the surface resistivity of SP and HP types was measured with various sample lengths, namely 100, 75, and 50 mm, respectively. The surface resistivity of each sample tends to increase linearly with the increasing size of the coated area. In addition, the surface resistivity of the HP is found to be higher than that of the SP. It could be confirmed that the surface resistivity increases as the curvature increases. For the electrical heating properties of the HP, a white-zone and a red-zone appeared clearly, and locally excess heat appeared at the white-zone; the resistive heat can be explained by the collision of the free electrons in the curved shape of the HP area. In order to confirm the applicability of the fabric heating elements, HP100/cotton, HP75/cotton, and HP50/cotton were fabricated by applying the HP to cotton fabric. The difference of surface temperatures at two points of each line of HP100/cotton, HP75/cotton, and HP50/cotton were about 6.0 ± 2.4℃, 6.8 ± 4.5℃, and 3.5 ± 1.7℃, respectively. It has been confirmed that the heating performance is improved, due to the collision of electrons in the curved region with decreasing HP100/cotton to HP50/cotton ratio, and the white-zone is also increased.

Sustainable Urban Development in the Green City: Kyrenia White Zone

Cities were first formed, they have been developed and advanced together with the development of humanity and technology. The cities in urbanization process have been going through technological, economical, social and cultural changes. These changes have brought along lots of problems affecting the environment humans live in. The environmental pollution caused by increasing population and degeneration of the environmental resources, and the problems caused by local economic and social disorganization have become the basic concerns of this area. The rapid population growth affects also the cities in social, cultural and economic manners. Especially with the increasing number of multi-story structure demolished in acts of urban centers, because of new and larger settlements housing, water, general health conditions, transportation, environmental degeneration, decrease in green fields etc. like these problems have been arose. The physical structure of a city is comprised of its habitants' social, cultural, economic aspects and their interaction with each other. In this study, in Kyrenia White Zone and Environmental Protection Area encountered in the development process like economic, ecological, environmental problems, and the green field areas that being destroyed day by day are analyzing for the city effects. While evaluating this analysis, LEED ND neighborhood scale, which is created for the advancement in urban sustainability and which is one of the environmental-performance certificate and evaluation systems have been preferred. In this study, the green fields, environmental problems, economic and ecological developments of the region were also taken into account. In order to learn the size of the development and problems, 5 regions-including environment protection region-with different aspects were chosen and a survey was conducted.