Laparoscopic Sugarbaker repair of parastomal hernia following radical cystectomy and ileal conduit: a single-center experience.

PURPOSE: Parastomal hernia (PH) is a frequent complication following radical cystectomy and ileal conduit. The purpose of this study was to summarize the clinical experience and technical characteristics of laparoscopic Sugarbaker repair of PH following radical cystectomy and ileal conduit. METHODS: We retrospectively evaluated all patients who underwent laparoscopic treatment of PH following radical cystectomy and ileal conduit at Huashan Hospital, Fudan University from May 2013 to December 2022. RESULTS: Thirty-five patients were included in the study. Median follow up was 32months (IQR, 25-38 months). Three patients presented with a recurrence (8.6%), with a median time to recurrence of 14 months. Out of the 35 patients, Thirty-two underwent totally laparoscopic repair using the Sugarbaker technique, Three patients required open surgery to repair the intestinal injury after laparoscopic exploration. One patient died 9 months post-surgery due to COVID-19. During the follow-up period, two patients developed a peristomal abscess, and one patient experienced partial intestinal obstruction 10 days after surgery. CONCLUSION: Surgical management of PH following radical cystectomy and ileal conduit is challenging. The laparoscopic Sugarbaker technique for repairing PH following radical cystectomy and ileal conduit has low complication and recurrence rate.

Lap-re-Do Keyhole versus Lap-re-Do Sugarbaker techniques in large parastomal hernia repair: a retrospective cohort study.

PURPOSE: To review the safety and efficacy of Lap-re-Do technique in the treatment of large parastomal hernia. METHODS: We retrospectively analyzed the recurrence and complications of 81 patients with large parastomal hernia who underwent Lap-re-Do technique in Huashan Hospital of Fudan University from May 2010 to December 2019. And the patients should be able to complete follow-up. With such criteria, we included 40 Lap-re-Do Keyhole patients and 41 Lap-re-Do Sugarbaker patients. Observation time was defined as time to recurrence, death, or last nonevent visit. RESULTS: In large parastomal hernias, Lap-re-Do had a recurrence rate of 25.9% and complication rate of 16.0%, and reoperation rate of 9.9% during the average follow-up time of 41.1 ± 17.8 months. Recurrence rates were 40% (16/40) after Lap-re-Do Keyhole repair and 12.2% (5/41) after Lap-re-Do Sugarbaker repair. Complication rates were 12.5% after Lap-re-Do keyhole and 19.5% after Lap-re-Do Sugarbaker repair Re-operation rates referred to Lap-re-Do keyhole repair were 15% and Lap-re-Do Sugarbaker repair 4.9% during follow-up.The majority of reoperations were indicated by recurrence. CONCLUSIONS: Large parastomal hernias are still difficult to be treated. Lap-re-Do Sugarbaker is recommended as an appropriate procedure to close the hernia ring, removing the lengthy colostomy, and effectively reduce recurrence and complication rates.

Toward Sub-Terahertz: Space-Time Coding Metasurface Transmitter for Wideband Wireless Communications.

A space-time coding metasurface (STCM) operating in the sub-terahertz band to construct new-architecture wireless communication systems is proposed. Specifically, a programmable STCM is designed with varactor-diode-tuned metasurface elements, enabling precise regulation of harmonic amplitudes and phases by adjusting the time delay and duty cycle of square-wave modulation signal loaded on the varactor diodes. Independent electromagnetic (EM) regulations in the space and time domains are achieved by STCM to realize flexible beam manipulations and information modulations. Based on these features, a sub-terahertz wireless communication link is constructed by employing STCM as a transmitter. Experimental results demonstrate that the STCM supports multiple modulation schemes including frequency-shift keying, phase-shift keying, and quadrature amplitude modulations in a wide frequency band. It is also shown that the STCM is capable of realizing wide-angle beam scanning in the range of ±45o , which offers an opportunity for user tracking during the communication. Thus, the STCM transmitter with high device density and low power consumption can provide low-complexity, low-cost, low-power, and low-heat solutions for building the next-generation wireless communication systems in the sub-terahertz frequency and even terahertz band.

Ka-band beam-scanning leaky-wave antenna fed by reconfigurable spoof surface plasmon polaritons.

A leaky-wave antenna (LWA) based on reconfigurable spoof surface plasmon polaritons (SSPP) is proposed for beam scanning in the Ka band, which consists of a reconfigurable SSPP waveguide and a periodic array of metal rectangular split rings. Both numerical simulations and experimental measurements show that the reconfigurable SSPP-fed LWA has good performance in the frequency range from 25 to 30 GHz. Specifically, as the bias voltage changes from 0 to 15 V, we can achieve the maximum sweep range of 24° at a single frequency and 59° at multiple frequency points, respectively. Owing to the wide-angle beam-steering feature, as well as the field confinement and wavelength compression properties derived from the SSPP architecture, the proposed SSPP-fed LWA possesses great potential applications in the compact and miniaturized devices and systems of the Ka band.

Surgical strategies for recurrent parastomal hernia after a primary repair with a Dynamesh® IPST mesh.

PURPOSE: To introduce our surgical strategies for recurrent parastomal hernia after a primary repair with a Dynamesh® IPST mesh. METHODS: Ten patients who underwent recurrent parastomal hernia repair with previous Dynamesh® IPST mesh use were analyzed retrospectively. Distinct surgery strategies were applied. Accordingly, we investigated the recurrence rate and postoperative complications in these patients, who were followed for an average of 35.9 months after surgery. RESULTS: There was no recorded death and no readmission during the 30-day postoperative period. And the lap-re-do Sugarbaker group had no recurrence, whereas the open suture group had one recurrence (16.7%). One patient in the Sugarbaker group developed ileus and recovered conservatively during the follow-up period. There were no other complications, including seroma, mesh infection and bulging, or prolonged postoperative pain. CONCLUSIONS: We offer two predominant surgery strategies for recurrent parastomal hernia with a previous Dynamesh® IPST mesh usage, the open suture repair, and the Lap-re-do Sugarbaker repair. Even though the results of the Lap-re-do Sugarbaker repair are satisfactory, we recommend the open suture technique as it is safer in a setting of dense adhesions in recurrent parastomal hernias.

Quantitative Analysis of Abdominal Muscles Using Elastography in Female Patients With Incisional Hernia.

This study aimed to assess the thickness and shear wave speed (SWS) of the anterolateral abdominal wall muscles in female patients with incisional hernias of different widths, in order to analyze the biomechanical properties of abdominal wall muscles. This study included 53 patients with incisional hernia (Group A [hernia width <4 cm]: 21 patients, Group B [hernia width ≥4 cm]: 32 patients). The muscle thickness and SWS values of the external oblique (EO), internal oblique (IO), and transversus abdominis (TrA), and the hernia width were measured using Siemens Acuson S2000 ultrasound systems. Four detection points were labeled on the anterolateral abdominal wall: points 1, 2, 3, and 4, corresponding to the upper right, upper left, lower right, and lower left, respectively. The muscle thickness of the IO at point 3 was significantly different between both groups (p = 0.024). Group B had significantly higher SWS values than Group A, especially for the EO (points 1, 2, and 3), IO (points 1 and 2), and TrA (points 2 and 4) (p < 0.05). Pearson correlation analysis shows no significant correlation between muscle thickness and the SWS values of EO, IO, and TrA (all p > 0.05). Linear correlation analysis showed a significantly positive correlation between hernia width and the mean SWS value of EO, IO, and TrA (p = 0.004, 0.005, and 0.043, respectively). Muscle thickness was not reliable measure to directly reflect the biomechanical changes of the abdominal wall muscles in patients with incisional hernia. Comparatively, SWE can accurately measure the stiffness of the abdominal wall muscles and intuitively evaluate its biomechanical properties.

Flexible Terahertz Beam Manipulations Based on Liquid-Crystal-Integrated Programmable Metasurfaces.

Terahertz wave manipulations, especially the phase manipulations, through metasurfaces has attracted considerable interests. Here, we develop a terahertz beam steering device using the liquid-crystal (LC)-integrated programmable metasurface. Specifically, a reflective-type 1 bit metasurface element is designed by employing a multilayer structure composed of metallic back plate-LC-complementary split ring resonator (CSRR). Numerical simulations show that, at the optimized operation frequency of 0.675 THz, the developed metasurface element has a nearly 180° phase difference between unbiased and biased states with close reflection amplitudes. Furthermore, a one-dimensional programmable metasurface array with 32 independently controlled subarrays is designed and fabricated using the lithography technology. Both simulated and measured far-field scattering patterns of the metasurface certify the anomalous beam reflection and wide-angle beam steering performances. Nevertheless, the optimal frequency red shifts to 0.645 THz in the experiment. This work may advance the application of metasurfaces in terahertz beam manipulation devices.

Muscle elasticity is different in individuals with diastasis recti abdominis than healthy volunteers.

OBJECTIVE: To determine the value of shear wave elastography (SWE) in assessing abdominal wall muscles, including rectus abdominis (RA), external oblique muscle (EO), internal oblique muscle, and transversus abdominis (TrA) in patients with diastasis recti abdominis (DRA) and healthy controls. METHODS: From October 2018 to December 2019, 36 postpartum DRA patients and 24 nulliparous healthy women were identified. Inter-rectus distance (IRD) measurements were taken by B-mode ultrasound. Shear wave speed (SWS) values were acquired by one operator at ten specific locations. Clinical and ultrasound variables, including demographics, IRD, muscle thickness, and muscle SWS, were compared between the two groups using Student's t test or Fisher's exact test. Pearson correlation analyses were conducted for the variables of IRD, muscle thickness, and SWS in the 36 DRA patients. RESULTS: The maximum diameter of recti abdominus separation was located at the umbilicus in DRA patients (4.59 ± 1.14 cm). The SWS value was significantly lower in the RA (p = 0.003) and higher in the TrA muscle (p < 0.001) in DRA patients compared with the age-matched controls. However, SWS in both muscles (RA and TrA) showed a statistically positive correlation with IRD (p < 0.05). In addition, the SWS value in EO statistically decreased in DRA patients compared with the healthy controls (1.65 ± 0.15 vs. 1.79 ± 0.14, p = 0.001). CONCLUSIONS: The application of SWE to abdominal wall muscles in DRA patients is feasible. The correlation between SWS value and IRD in RA should be interpreted with caution.

Programmable Reflection-Transmission Shared-Aperture Metasurface for Real-Time Control of Electromagnetic Waves in Full Space.

Recently, programmable metamaterials or metasurfaces have been developed to dynamically edit electromagnetic waves for realizing different functions in the same platform. However, the proposed programmable metasurfaces can only control reflected or transmitted wavefronts in half-space. Here, a "Janus" digital coding metasurface with the capabilities to program various electromagnetic functions in the reflected (with R-codes) and transmitted (with T-codes) waves simultaneously is presented. Three PIN diodes are employed to design the metaparticle, and the state of the PIN diodes can be switched to change the reflected and transmitted phases independently. Three schemes achieved by the proposed programmable metasurface are provided as illustrative examples, including anomalous deflections, beam focusing, and scattering reduction in the full space. As a proof-of-concept, a prototype composed of 10 × 20 metaparticles is fabricated and the measured results are in good agreement with the designs and numerical results, validating the full-space modulations enabled by the programmable metasurface. It is expected that the new programmable metasurface can broaden the applications in stealth technologies, imaging systems, and the next generation of wireless communications.

A new technique for the 3D reconstruction of the incisional hernia: A pilot study.

PURPOSE: This study aimed to accurately evaluate incisional hernias with a new three-dimensional (3D) reconstruction technology, proving surgeons more information for intuitive and accurate judgments about incisional hernia to minimize the perioperative complications and recurrence rate. METHOD: This was a pilot study using a new technique, 3D reconstruction, based on computed tomography (CT) scans to measure abdominal wall defect, herniary area, herniary volume, abdominal cavity volume, and the volume of transverse, oblique, and recti abdominis in three patients with incisional hernias. RESULTS: The 3D reconstruction technique made automated segmentation of the bony skeleton, skin, outer abdominal wall, vessel, and hernia sac. The hernia sac, abdominal muscles, and their anatomic relationship were clearly illustrated in 3D reconstruction images. Moreover, abdominal cavity volume; herniary diameter, area, and volume; and the volume of transverse, oblique, and recti muscles could be evaluated through 3D reconstruction images. Surgeons can also freely combine, rotate, scale, and move the 3D reconstruction mode, modify the name and transparency of the 3D reconstruction model, and observe the internal structure of the tissue and the size, shape, and location of the lesion from multiple angles for better and accurate judgments. CONCLUSION: The herniary diameter, area, and volume and the volume of transverse, oblique, and recti abdominis can be accurately calculated through this 3D reconstruction technology. A three-dimensional vision of the abdomen through this technology can objectively and quantitatively evaluate the situation of incisional hernia, providing a more realistic means for diagnosis and treatment of incisional hernias.

Use of Shear Wave Elastography to Quantify Abdominal Wall Muscular Properties in Patients With Incisional Hernia.

Shear wave elastography (SWE) is a potential modality that quantitatively measures the elasticity (shear wave speed [SWS]) of musculoskeletal structure. This SWS was bilaterally measured in the rectus abdominis (RA), external oblique (EO) muscle, internal oblique (IO) muscle and transversus abdominis (TrA) using SWE in 28 patients with incisional hernia and 14 healthy controls. The differences in muscle thickness for IO and TrA were significant between the two groups (p < 0.05). The SWS of RA, EO, IO and TrA was significantly higher in the incisional hernia patient group than in the healthy controls (p < 0.05). Significant differences were also observed between the upper and lower points in both groups (p < 0.05). The measurements of SWS help in evaluating the elastic properties of abdominal wall muscles, which could further aid in preparing treatment plans to improve muscle strength.

Development and validation of nomograms for prediction of overall survival and cancer-specific survival of patients of colorectal cancer.

PURPOSE: Nomograms are intuitive tools for individualized cancer prognosis. We sought to develop a clinical nomogram for prediction of overall survival and cancer-specific survival for patients with colorectal cancer. METHODS: Patients with colorectal cancer diagnosed between 1988 and 2006 and those who underwent surgery were retrieved from the Surveillance, Epidemiology, and End Results database and randomly divided into the training (n = 119 797) and validation (n = 119 797) cohorts. Log-rank and multivariate Cox regression analyses were used in our analysis. To find out death from other cancer causes and non-cancer causes, a competing-risks model was used, based on which we integrated these significant prognostic factors into nomograms and subjected the nomograms to bootstrap internal validation and to external validation. RESULTS: The 1-, 3-, 5- and 10-year probabilities of overall survival in patients of colorectal cancer after surgery intervention were 83.04, 65.54, 54.79 and 38.62%, respectively. The 1-, 3-, 5- and 10-year cancer-specific survival was 87.36, 73.44, 66.22 and 59.11%, respectively. Nine independent prognostic factors for overall survival and nine independent prognostic factors for cancer specific survival were included to build the nomograms. Internal and external validation CI indexes of overall survival were 0.722 and 0.721, and those of cancer-specific survival were 0.765 and 0.766, which was satisfactory. CONCLUSIONS: Nomograms for prediction of overall survival and cancer-specific survival of patients with colorectal cancer. Performance of the model was excellent. This practical prognostic model may help clinicians in decision-making and design of clinical studies.

Phi-based risk calculators performed better in the prediction of prostate cancer in the Chinese population.

Risk prediction models including the Prostate Health Index (phi) for prostate cancer have been well established and evaluated in the Western population. The aim of this study is to build phi-based risk calculators in a prostate biopsy population and evaluate their performance in predicting prostate cancer (PCa) and high-grade PCa (Gleason score ≥7) in the Chinese population. We developed risk calculators based on 635 men who underwent initial prostate biopsy. Then, we validated the performance of prostate-specific antigen (PSA), phi, and the risk calculators in an additional observational cohort of 1045 men. We observed that the phi-based risk calculators (risk calculators 2 and 4) outperformed the PSA-based risk calculator for predicting PCa and high-grade PCa in the training cohort. In the validation study, the area under the receiver operating characteristic curve (AUC) for risk calculators 2 and 4 reached 0.91 and 0.92, respectively, for predicting PCa and high-grade PCa, respectively; the AUC values were better than those for risk calculator 1 (PSA-based model with an AUC of 0.81 and 0.82, respectively) (all P < 0.001). Such superiority was also observed in the stratified population with PSA ranging from 2.0 ng ml-1to 10.0 ng ml-1. Decision curves confirmed that a considerable proportion of unnecessary biopsies could be avoided while applying phi-based risk calculators. In this study, we showed that, compared to risk calculators without phi, phi-based risk calculators exhibited superior discrimination and calibration for PCa in the Chinese biopsy population. Applying these risk calculators also considerably reduced the number of unnecessary biopsies for PCa.

[Interpretation of 2017 European Hernia Society Guidelines for The Prevention and Treatment of Parastomal Hernias].

European Hernia Society issued a guideline for the prevention and treatment of parastomal hernias in 2017, which is the first international guideline for the parastomal hernia. This guideline proposed 12 problems about incidence, diagnosis and treatment, and discussed these problems in depth. The main contents of this guideline are summarized as follows: (1) End colostomy is associated with a higher incidence of parastomal hernia compared to other types of stomas. (2) Clinical examination is necessary for the diagnosis of parastomal hernia, whereas computed tomography scan or ultrasonography may be performed in cases of diagnostic uncertainty. (3) The use of the European Hernia Society classification for uniform research reporting is recommended. (4) There is insufficient evidence on the policy in watchful waiting. (5) There is insufficient evidence on the route and location of stoma construction, and the size of the aperture. (6) The use of a prophylactic synthetic non-absorbable mesh upon construction of an end colostomy is strongly recommended. No such recommendation can be made for other types of stomas at present.(7) It is strongly recommended to avoid performing a suture repair for elective parastomal hernia. (8) So far, there is no sufficient comparative evidence on specific techniques, open or laparoscopic surgery and specific mesh types. However, most data in this guideline were retrospective without high level evidence. A lot of questions remain controversial and more high-level evidence are expected to solve these problems.

Testosterone regulates 3T3-L1 pre-adipocyte differentiation and epididymal fat accumulation in mice through modulating macrophage polarization.

Low testosterone levels are strongly related to obesity in males. The balance between the classically M1 and alternatively M2 polarized macrophages also plays a critical role in obesity. It is not clear whether testosterone regulates macrophage polarization and then affects adipocyte differentiation. In this report, we demonstrate that testosterone strengthens interleukin (IL) -4-induced M2 polarization and inhibits lipopolysaccharide (LPS)-induced M1 polarization, but has no direct effect on adipocyte differentiation. Cellular signaling studies indicate that testosterone regulates macrophage polarization through the inhibitory regulative G-protein (Gαi) mainly, rather than via androgen receptors, and phosphorylation of Akt. Moreover, testosterone inhibits pre-adipocyte differentiation induced by M1 macrophage medium. Lowering of serum testosterone in mice by injecting a luteinizing hormone receptor (LHR) peptide increases epididymal white adipose tissue. Testosterone supplementation reverses this effect. Therefore, our findings indicate that testosterone inhibits pre-adipocyte differentiation by switching macrophages to M2 polarization through the Gαi and Akt signaling pathways.

Bifunctional metamaterials with simultaneous and independent manipulation of thermal and electric fields.

Metamaterials offer a powerful way to manipulate a variety of physical fields ranging from wave fields (electromagnetic field, acoustic field, elastic wave, etc.), static fields (static magnetic field, static electric field) to diffusive fields (thermal field, diffusive mass). However, the relevant reports and studies are usually limited to a single physical field or functionality. In this study, we proposed and experimentally demonstrated a bifunctional metamaterial which could manipulate thermal and electric fields simultaneously and independently. Specifically, a composite with independently controllable thermal and electric conductivity was introduced, on the basis of which a bifunctional device capable of shielding thermal flux and concentrating electric current simultaneously was designed, fabricated and characterized. This work provides an encouraging example of metamaterials transcending their natural limitations, which offers a promising future in building a broad platform for the manipulation of multi-physics fields.

Mode jumping of split-ring resonator metamaterials controlled by high-permittivity BST and incident electric fields.

We investigate the resonant modes of split-ring resonator (SRR) metamaterials that contain high-permittivity BST block numerically and experimentally. We observe interesting mode-jumping phenomena from the BST-included SRR absorber structure as the excitation wave is incident perpendicularly to the SRR plane. Specifically, when the electric field is parallel to the SRR gap, the BST block in the gap will induce a mode jumping from the LC resonance to plasmonic resonance (horizontal electric-dipole mode), because the displacement current excited by the Mie resonance in the dielectric block acts as a current channel in the gap. When the electric field is perpendicular to the gap side, the plasmonic resonance mode (vertical electric-dipole mode) in SRR changes to two joint modes contributed simultaneously by the back layer, SRR and BST block, as a result of connected back layer and SRR layer by the displacement current in the BST dielectric block. Based on the mode jumping effect as well as temperature and electric-field dependent dielectric constant, the BST-included SRR metamaterials may have great potentials for the applications in electromagnetic switches and widely tunable metamaterial devices.

Terahertz time domain spectroscopic investigation of spin reorientation transitions in HoFeO3.

Both continuous and discontinuous spin reorientation transitions in the HoFeO3 orthoferrite have been further investigated in this paper. Here, we use terahertz spectroscopy through the terahertz ferromagnetic and antiferromagnetic resonances to study the thermodynamics of the spin reorientation transitions in HoFeO3 ceramics. The spin reorientations are driven by changes in the anisotropy energy, and the spin moments in and out of the (a, c) plane correspond to the continuous transitions and discontinuous transitions. We fitted the antiferromagnetic resonant frequencies, and we achieved quantitative insight on the changes in anisotropy energy. Measuring M-H (moment-magnetic field) curves, we found changes in macroscopic magnetization and verified the thermodynamics.

Ultralow temperature terahertz magnetic thermodynamics of perovskite-like SmFeO3 ceramic.

The terahertz magnetic properties of perovskite-like SmFeO3 ceramic are investigated over a broad temperature range, especially at ultralow temperatures, using terahertz time-domain spectroscopy. It is shown that both resonant frequencies of quasi-ferromagnetic and quasi-antiferromagnetic modes have blue shifts with the decreasing temperature due to the enhancement of effective magnetic field. The temperature-dependent magnetic anisotropy constants are further estimated using the resonant frequencies, under the approximation of omitting the contribution of Sm(3+) magnetic moments to the effective field. Specially, the effective anisotropy constants in the ca and cb planes at 3 K are 6.63 × 10(5) erg/g and 8.48 × 10(5) erg/g, respectively. This thoroughly reveals the terahertz magnetic thermodynamics of orthoferrites and will be beneficial to the application in terahertz magnetism.

Anisotropic terahertz dielectric responses of sodium nitrate crystals.

Terahertz (THz) spectroscopy has become an effective tool to characterize the low-frequency rotational and vibrational modes of molecules. In addition, novel THz dielectric responses and optical properties on the basis of molecular rotation and vibration have attracted lots of attention because of their potential application in THz devices. In this paper, the dielectric response of low-symmetric sodium nitrate crystals in the frequency range of 0.2-1.5 THz was experimentally demonstrated. Four absorption bands at 0.23, 0.47, 0.92, and 1.15 THz were observed in the dielectric spectra and were tentatively ascribed to the rotational motion of nitrate ions. Based on the molecular rotation mechanism, the dielectric anisotropy and dielectric resonance of the crystal were discussed in detail.