Point Of Maximum Curvature Research Articles

Pattern formation from homogeneous states for an elliptic system with mixed interactions

In this paper, we are interested in the asymptotic behavior of a ground state vector solution for the following coupled nonlinear Schrödinger system { Δ u 1 − λ 1 u 1 + β 11 ( u 1 ) 3 + α β 12 u 1 ( u 2 ) 2 − β β 13 u 1 ( u 3 ) 2 = 0 Δ u 2 − λ 2 u 2 + α β 21 ( u 1 ) 2 u 2 + β 22 ( u 2 ) 3 − β β 23 u 2 ( u 3 ) 2 = 0 Δ u 3 − λ 3 u 3 − β β 31 ( u 1 ) 2 u 3 − β β 32 ( u 2 ) 2 u 3 + β 33 ( u 3 ) 3 = 0 in Ω and ∂ u i ∂ n = 0 on ∂Ω when α , β > 0 are very large. The existence of a ground state vector solution for (1) was proved in Byeon et al. [Pattern formation via mixed interactions for coupled Schrödinger equations under Neumann boundary condition. J Fixed Point Theory Appl. 2017;19:559–583] when α , β , α / β 2 − n 2 are large. We prove that if λ 3 is small, as α , β , α / β 2 − n 2 → ∞ , u 3 converges to a constant, u 1 and u 2 develop a small peak on ∂Ω . Under an additional condition α / β 2 − n 2 + δ → ∞ for some δ > 1 , we show that the peak point converges to a maximum point of the mean curvature of ∂Ω .

(187) The SAPOC Technique: Slices Around Point of Maximal Curvature at Time of IPP placement in Severe Peyronie's Disease

Abstract Introduction Placement of an inflatable penile prosthesis (IPP) is indicated for patients with severe Peyronie's disease and erectile dysfunction (ED). Most cases involving plaque incision and graft placement are performed at the point of maximal curvature which result in a large defect that requires placement of a large graft while postoperative penile shortening remains a significant concern among patients. Objective To present a video of a novel modification of the multiple slit technique (MUST) for the treatment of severe PD and ED during IPP placement. This technique involves multiple relaxing incisions made around the point of maximal curvature (POMC) which minimizes the size or even the need of a graft while allowing for length restoration. Methods This technique involves elevation of the neurovascular bundle for dorsal or lateral curvatures along with elevation of the urethra for ventral curvatures. After the POMC is identified, 2 to 4 transverse relaxing incisions (slices) are made around the POMC approximately 1 to 1.5cm apart in order to minimize the size of the defect and hence the need or size of the graft. Each slice allows for maximal restoration of length. Results The SAPOC technique results in correction of curvature and length restoration. Conclusions The SAPOC technique at the time of IPP placement is a novel, safe and feasible technique for the management of complex PD and ED. This technique allows the surgeon to complete the procedure without graft placement in some occasions which theoretically will decrease operative time. It also provides for length restoration which will increase patient satisfaction. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Consultant for Boston Scientific and Coloplast.

(402) Peyronie's Disease Treatment- Active Vs. Stable Phase- Retrospective Review of Cases

Abstract Introduction Peyronie's disease (PD) may be treated with collagenase clostridium histolyticum (CCH) during the stable phase. However, the effectiveness and safety of this treatment during the active phase remain unclear. To address this, we investigated and compared the outcomes of patients receiving treatment in the active phase versus the stable phase of PD. Objective To assess the effectiveness and safety of CCH treatment in patients diagnosed with PD during the active phase. Methods A retrospective review was conducted on men who underwent at least one cycle of CCH injections for PD with a single fellowship-trained urologist between 2017 and 2023. Active PD was defined as occurring within one year from the onset of symptoms. The severity of penile curvature was measured at the point of maximal curvature and assessed at baseline and after each CCH cycle. In addition to the CCH treatment, patients were prescribed daily phosphodiesterase inhibitors (PDEi) and coenzyme-Q10 (CoQ-10). The treatment response was defined as any improvement in curvature from baseline to the final assessment. The characteristics and outcomes of patients were compared between those with active and stable PD. Results Of 107 patients who underwent CCH treatment, 75 were diagnosed with stable PD and 32 with active PD. There were no significant differences observed between the two groups in terms of age (58.1 vs. 57.9 years, p = 0.89), baseline curvature (58.4 vs. 60.5 degrees, p = 0.60), or the number of CCH cycles received (6.6 vs. 6.3 cycles, p = 0.57). Among the active PD patients, 26 (81.2%) experienced an improvement in curvature, which was comparable to the stable PD group (58 (77.3%), p = 0.85). There were no significant differences in the degree of curvature improvement (14.4 vs. 14.0 degrees, p = 0.91) or the percentage of improvement from baseline (22.67% vs. 24.05%, p = 0.86) between the active and stable PD patients. In the subset of patients who showed an improvement in curvature angle, there was no notable distinction in the percentage of improvement from baseline between the stable and active phases (37.4% vs 34.8%, p=0.63). Among the treated patients, we observed two cases of potential penile fractures in the stable phase. All adverse events were conservatively managed. Conclusions Patients treated with CCH during the active phase achieved comparable outcomes to those in the stable phase. There were no additional adverse events in the active phase treatment group. These data suggest that early active phase treatment yields similar effectiveness as treatment administered during the stable phase. Treatment during the active phase could be a disease modifier and may change the course of progression. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Endo, Roman Health.

Changes in Point of Maximal Curvature During Collagenase Clostridium Histolyticum Injections for Peyronie’s Disease

ObjectivesTo determine change in the point of maximal curvature (POMC) during Collagenase Clostridium histolyticum (CCH) injections for Peyronie’s disease (PD). MethodsA prospective database has been maintained of all men undergoing CCH injections since March 2014. For the current study, data were abstracted on the POMC with each curve assessment and correlated with demographic and clinical factors. Maximal changes were defined as the largest change in POMC from baseline. Results618 men underwent ≥1 series of CCH, with 313 having a baseline and subsequent POMC measurements available. Median baseline curvature was 60.0° and POMC 2.8 cm. Among 189 men who were satisfied or completed 8 CCH injections, the median improvement in penile curvature was -27.5° (40.9%). The median maximal change in POMC during CCH treatment was 1.0 cm (IQR, 0.5, 1.8). Overall, 55.6% had changes in POMC of ≥1 cm, 23.6% ≥2 cm, 8.9% ≥3 cm, and 3.8% ≥4 cm. Multivariate logistic regression identified ventral curvature as a predictor of larger change in POMC, after controlling for other variables. Study limitations included the observational, non-randomized study design and potential for intra- and inter-individual measurement variability. Strengths are the inclusion of an all-comer population, large series, prospective database, and routine objective assessments. ConclusionsApproximately half of PD men undergoing CCH experience ≥1 cm of change in POMC during the treatment course, with nearly 1/4 experiencing ≥2 cm. Pending external validation, findings suggest that patients may benefit from repeat curvature assessments with each CCH series to optimize accuracy of drug administration.

A cooperative regulation method for greenhouse soil moisture and light using Gaussian curvature and machine learning algorithms

Soil moisture (SM) exerts a significant impact on crop growth, interacting with environmental factors such as temperature, photosynthetic photon flux density (PPFD), and CO2, ultimately affecting crop photosynthesis (Pn). This study employs a nested experimental design to investigate the photosynthetic activity of cucumber seedlings under diverse environmental conditions and establishes a support vector regression (SVR) model for Pn prediction. The SVR model takes temperature, PPFD, SM, and CO2 concentration as inputs and demonstrates a high level of accuracy (The model’s coefficient of determination = 0.9830, root mean square error = 0.9138). Subsequently, through a generalized additive model, the study unveils the significant impact of interactions between SM and PPFD on Pn. Accordingly, this research constructs a Pn response surface based on these two factors and identifies the maximum point of Gaussian curvature on this surface. Polynomial regression is applied to these points, yielding a comprehensive regulation strategy for SM and PPFD. In comparison to traditional methods based on maximizing Pn, this innovative approach reduces Pn by 12.9 % while significantly conserving light (35.59 %) and water (32.80 %) consumption. Although no significant changes are observed in crop physiological traits (plant height, stem diameter, dry weight, fresh weight), substantial variations are noted in irrigation volume and PPFD consumption. Thus, the regulation strategy proposed in this study embodies efficiency and energy conservation in greenhouse crop cultivation.

A path planning algorithm for three-dimensional collision avoidance based on potential field and B-spline boundary curve

Path planning is one of the key technologies in unmanned aerial systems. The path-planning algorithm for UAVs in this study incorporates a three-dimensional obstacle model, addressing the limitations of existing research that primarily focuses on the two-dimensional plane. This approach elevates traditional two-dimensional obstacle constraints to a three-dimensional space, fulfilling the requirements for precise obstacle avoidance. Utilizing B-spline curves, an obstacle boundary model is proposed, which, in combination with an improved artificial potential field accounting for localized self-locking oscillations, achieves smooth path planning for obstacle avoidance from the starting point to the destination. The simulation results show the effectiveness of this method in collision-free path planning within three-dimensional environments containing static single or multiple obstacles. At the points of maximum curvature in the two-dimensional coordinate system, the path planned by the proposed algorithm exhibits a smoothness improvement of 68 % and 98 %, respectively, as compared to the traditional artificial potential field algorithm with the equivalent three-dimensional obstacle model and the tangent point method. The proposed algorithm enables drones to achieve precise obstacle avoidance along surfaces, generating smoother collision-free flight paths in a shorter period of time.

Correction of curvature in single stage hypospadias repair with foreskin reconstruction

Many surgeons offer foreskin reconstruction (FR) as a routine part of hypospadias repair. We present a step-by-step video of the procedure of Tubularised Incised Plate (TIP) repair, FR and dorsal plication through a ventral skin incision. A ventral incision is made between the inner preputial mucosa and the outer skin extending below the meatus. Ventral degloving is carried out. The dissection is extended laterally around the corporal bodies. The point of maximal curvature (PMC) is marked on the dorsal midline. A vertical incision is made and closed transversely with 5-0 prolene suture in a Heineke- Mikulicz fashion. Urethroplasty is performed in 2 layers using 7-0 polydioxanone (PDS). Spongioplasty and ventral dartos are used as barrier layers. Glansplasty is performed in 2 layers.FR is carried out in 3 layers. Curvature correction is key to good outcome. Dorsal degloving can be achieved through a ventral incision allowing exposure of the dorsal midline for plication sutures. The patient had good cosmetic and functional outcome at 1 month follow up. FR can be safely performed during TIP repair for distal hypospadias repair. Curvature of less than 30° can be corrected through a ventral incision only.

A comparison of methods for the calculation of all the key points of the PV single-diode model including a new algorithm for the maximum power point

In this paper we describe and compare the methods for the calculation of all the key points of the photovoltaic single-diode model. These include the short-circuit point, the open-circuit point, the maximum power point, the mean slope point, the maximum curvature point, and the jerk point. The main contribution of this paper is a new algorithm to obtain the maximum power point which is based on reducing its computation to solve a single-variable equation. Its unique solution leads to an explicit expression of the point by using a recent parametrization of the single-diode model current–voltage curve. In the numerical resolution of the previous equation, we will use as starting point the mean slope point which has been proved to be close to the maximum power point. Previously, we will provide for the first time in the literature an exact and explicit expression of the mean slope point. The new algorithm proposed reaches the accuracy of the best known numerical methods, but it is much faster, almost reaching the execution times of explicit formulas.

Effects of Bending on Nucleation and Injection of Oxygen Vacancies into the Bulk Lattice of Li‐Rich Layered Cathodes

AbstractThe degradation of Li‐ and Mn‐rich (LMR) cathodes primarily results from the thermodynamic instability of lattice oxygen and the resulting oxygen release. This is promoted by localized lattice strain, which develops dynamically during electrochemical reactions involving repeated Li‐ion intercalation and extraction. However, the role of chemomechanical strain in degrading lattice oxygen's stability is not yet well‐understood. Here, the research indicates that uneven strain distribution causes bending, resulting in lower activation energy for oxygen vacancy creation and injection into particle interiors at bending points. Combining in situ transmission electron microscopy and theoretical simulations, it is shown that the largest O─O interaction occurs at the maximum curvature point, reducing Mn─O bonding strength, promoting oxygen dimer formation, and eventually initiating oxygen release from LMR. As a result, a process is designed to adjust the Li‐content and the distribution of the two‐phase structure, achieving better cycling stability in LMR cathodes with a more balanced distribution of strain. These results provide insights into enhancing LMR cycling stability while utilizing their high capacity.

A novel technique for unilateral dissection of the penile neurovascular bundle to prevent loss of penile sensation during treatment of Peyronie's disease-Initial results of a pilot study.

Plaque incision/excision and grafting are surgical techniques used to treat patients with Peyronie's disease who are refractory to less invasive interventions, have severe penile curvature, or have an hourglass deformity. However, the procedure carries the risk of penile sensory loss because of the need for dissection of the neurovascular bundle (NVB). The aim of this study was to assess the feasibility of a novel technique for unilateral NVB dissection and its ability to preserve penile sensitivity while maintaining adequate correction of the penile curvature. Charts of patients who underwent unilateral NVB dissection during Peyronie's plaque incision/excision and grafting were retrospectively reviewed. All patients received preprocedural intracavernosal injections of TriMix, and the curvature was measured to be >70 degrees. In 3 cases, an incision and minimal excision of the plaque were performed at the point of maximum curvature on the concave side of the curvature. In 3 cases, Tutoplast allografts (Coloplast US, Minneapolis, MN) were used, whereas autografts were used in 2 other cases. All patients were examined at 1, 3, and 6 months after the procedure when curvature and penile sensation were assessed. Five patients underwent this procedure. The mean age of patients was 55 years (45-70 years). All plaques were dorsally located. The mean preoperative curvature was 78 degrees (75-90 degrees). At the 6-month follow-up, all patients had <15 degrees residual curvature and were satisfied with their cosmetic results. Only 1 patient continued with phosphodiesterase-5 inhibitors to improve potency at the 6-month follow-up. All patients reported normal penile glans sensation. Four patients experienced decreased sensation at the site of NVB dissection, but this was only detected when compared with the contralateral side. Only 2 patients reported a difference after 6 months, and only a minor area of involvement was noted. Unilateral NVB dissection is a feasible technique that does not compromise surgical success in curvature correction and helps avoid sensory injury to the penile glans.

An adaptive metamodel-based global approximation method for black-box type problems

An adaptive metamodel-based global approximation (AMGA) method for solving the global approximation problem of black-box models in large design domain is proposed in this study. The method employs the RBF model to compute the Hessian matrix and a heuristic direct search algorithm DIRECT to find the maximum curvature point of the metamodel surface, through which the design domain is split to obtain additional sampling points and to achieve fast update and fast valuation of the metamodel. The initial design domain is split into a series of sub-design domains by continuous iterations, and the metamodels built within the various sub-design domains achieve the global approximate model of the entire design domain. To demonstrate the final effect of the global approximation model and design domain splitting, six common two-dimensional test functions are chosen. The AMGA method is further tested using seven typical test functions and compared to other sampling and metamodel updating methods, with the findings demonstrating the usefulness of the proposed method in the low-dimensional scenario (less than four variables). Finally, the AMGA method is applied to a sophisticated electric car model, yielding good results.

(410) Multiple Slit Incisions with Tachosil® Grafting for Treatment of Peyronie’s Disease and ED

Abstract Introduction Plaque incision or partial excision with collagen fleece grafting and IPP implantation is a well-established treatment for severe penile curvatures associated with ED. Nevertheless, multiple plaque incisions combined with Tachosil® grafting may have added advantages. Objective We demonstrate step-by-step the treatment of a case of severe ED with an over 60 degree dorsal curvature mainly on the left side and an hour glass indentation on the right side of the penile shaft. We highlight the advantages of multiple plaque incisions and Tachosil® grafting combined with IPP implantation for these specific cases. Methods After IPP implantation via the penoscrotal approach, the neurovascular bundle was mobilized. For the left sided curvature we underwent multiple deep transverse slits starting from and around the point of maximum curvature using a low energy cutting current (20 to 30 Watts). Our transverse incisions were complimented with the modeling technique. For the right sided waist formation we underwent longitudinal slits. The area of incisions was covered by a Tachosil® graft. Results The multiple horizontal incisions led to a vertical release thus straightening of the curved penile shaft. Longitudinal slits led to a horizontal release, therefore expanding and obliterating of the waist formation. Conclusions The multiple slit technique together with Tachosil® grafting may have added advantages compared to the conventional plaque incision/excision utilizing the same graft. The smaller defects created by the multiple tunical incisions may avoid potential cylinder protrusion, facilitate better sealing of the collagen fleece, lower the incidence of hematoma and/or infections and allow complimentary modeling of the penis. Moreover, complex deformities may also be treated simultaneously with success. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast.

(406) The “Kiel Knots” Technique for the Treatment of Congenital and Acquired Penile Curvature

Abstract Introduction Penile curvature is not only a cosmetic issue, but can also cause severe organic and psychological problems in the affected patients. It can negatively affect the quality of the person’s sexual life or even ruin a relationship. There are many surgical techniques for correction ranging from the least invasive as plication to more invasive as incision or excision and grafting. Objective We propose a surgical technique for the correction of both congenital and acquired penile curvatures. Our technique is based on modifying and combining the 16-dot and the Essed-Schroeder plication techniques by burying the knots in shallow troughs of the incised tunica albuginea. We entitle this modification as the “Kiel Knots”. In this video, we demonstrate step-by-step the Kiel Knots technique for the correction of a case of dorsal acquired curvature with good erectile function via the subcoronal approach. Methods A circumcising incision is made and the penis is degloved. Buck’s fascia is then incised exposing the tunica albuginea opposite the curvature. Eight dots 5mm apart are marked bilaterally on the tunica albuginea with the point of maximum curvature in the center and a 5 mm superficial incision along the marks is made without cutting into the corpus cavernosum. Instead of plicating with one suture for 4 dots, our modification entails utilizing a separate suture for every two dots with the knot being buried in the shallow trough we created by the scalpel. Results Our average operative time is an hour. An average loss of penile length of 0.5-1cm has been reported in 30% of our patients. All our patients preserved their erectile function. 90% of our patients remained without recurrence of curvature after 2 years of surgery. None of our patients reported problems with their suture knots. Conclusions The Kiel Knots technique achieves penile straightening with minimal loss of length and no erectile dysfunction. We believe that our technique combines the best of Lue’s 16 dot together with the Essed-Schroeder plication techniques while avoiding the downsides of both approaches. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast.

(402) Analysis of Peyronie’s Disease Injection Techniques

Abstract Introduction Collagenase clostridium histolyticum (CCH) is the only food and drug administration (FDA) approved intralesional medication for Peyronies Disease (PD). The manufacture instructions recommend a single injection into the plaque at the point of maximal curvature. However, a 2019 survey of the Sexual Medicine Society of North America (SMSNA) found that physicians were utilizing many different injection techniques. It is unknown if one technique is superior. Objective To assess delivery of medication into PD plaques using an invitro model. Methods We obtained PD plaques from men undergoing plaque excision and grafting. Plaques were stored at -80C until ready for use in the lab. We injected the plaques with 0.25ml of Eosin Y, 5 wt. 5% solution in water because this solution is visibly red and similar to the density of CCH. We assess how the dye spread through the plaque in four different injection techniques: single injection, single injection with slow pull back, multiple site injection and lateral injection. All injections were video recorded in real time. Results Dye was retained inside the plaques will all injection techniques, however in all conditions, a significant amount of dye leaked out of the plaques. Multiple injection technique appeared to have the least about of dye leak out of the plaque. Conclusions In all conditions, dye leaked out of the plaques, however the multiple injection technique appears to have deliver the greatest amount Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Endo Pharmaceuticals

(405) Penile Prosthesis Implantation and Peyronie's Disease: How to Approach the Residual Curvature – A Detailed Demonstration of Moulding Technique and Grafting Procedure

Abstract Introduction Insertion of a penile prosthesis is the treatment of choice in men with Peyronie’s disease and concomitant erectile dysfunction. The aim of surgery is to straighten the penis and allow adequate rigidity for sexual intercourse. A conundrum arises when there is residual curvature during device testing. Objective This video highlights strategies that will aid the implanter when faced with these intraoperative challenges. Methods This video illustrates three different scenarios and suggests strategies that can be used when there is a residual penile curvature following inflatable penile prosthesis insertion: 1) Manual moulding – In this scenario, a persistent left lateral curvature is successfully straightened by moulding the plaque following device insertion. The cylinders are fully inflated and the tubes to the pump are double clamped. One hand is positioned distal to the apex of the curvature while the other is proximal. The penis is manipulated in the opposite direction to the curvature. 2) Residual curvature after manual moulding – The plaque can be incised at the point of maximal curvature and grafted If there is a significant persistent curvature (&amp;gt;30 degrees) following moulding. A fibrin sealant patch was used in this patient and it offers a quick and effective choice for grafting the tunical defect. 3) Upfront plaque incision and grafting - Some patients are not suitable for moulding following penile prosthesis insertion. Examples include ventral penile curvature and ossified plaques. In this patient with a ventral curvature, the plaque was incised and the tunical defect grafted with bovine pericardial graft prior to corporal dilatation. Results All three patients had an uneventful post-operative outcome. They were encouraged to cycle the device from 3 weeks and allowed to commence sexual intercourse after 6 weeks post-surgery. Conclusions Manual moulding is a safe and effective first line option for residual penile curvature following inflatable penile prosthesis insertion. Plaque incision and grafting can be considered if moulding fails or where manual moulding is contraindicated. There are several choices for graft material including fibrin sealant patch or bovine pericardium. Disclosure No

PARAMETERS CONTROLLING THE GEOMETRY OF DETACHMENT AND FAULT‐BEND FOLDS: INSIGHTS FROM 3D FINITE‐ELEMENT MODELS APPLIED TO THE AHWAZ ANTICLINE IN THE DEZFUL EMBAYMENT, SW IRAN

Fault‐related folds are present in most tectonic settings and can serve as structural traps for hydrocarbons. These structures have therefore been widely studied by both structural and petroleum geologists using a range of techniques. Approaches include field‐ and seismic‐based methods, and numerical and analogue modelling. Geomechanical models attempt to examine the mechanical and geometric features of folds.This study investigates the effects of variations in a range of parameters, including detachment and ramp geometry, friction coefficient and internal friction angle, on the geometry and development of detachment folds and fault‐bend folds. For this purpose, we ran seven series of numerical, 3D elastic‐plastic finite element models using ABAQUS software (26 model runs in all). Each model set‐up consisted of five layers whose mechanical properties were based on those of stratigraphic units in the Zagros fold‐and‐thrust belt, SW Iran. The models were labelled series A to F and series H. Models in series A investigated the impact of concave, convex, wavy and oblique detachment surfaces on the development of detachment folds; those in series D examined the role of ramp dip and of listric, oblique and wavy ramps on the development of fault‐bend folds. Models in series B and E, and series C and F, examined the effects of variations in the friction coefficient and of the internal friction angle, respectively, on the development of these two classes of folds. Finally, hybrid models in series H were provided to evaluate the results.Major results were as follows. Firstly, the geometry of modelled detachment and fault‐bend folds was found to be influenced by the geometry of the associated ramps and detachment faults. Thus the crests of anticlines and the trough lines of synclines were located at points of maximum curvature and at inflexion points on a wavy detachment fault or wavy ramp, respectively. Second, two important additional factors controlling fold style were identified: the friction coefficient, and the presence of along‐strike geometric variations in the ramp or the detachment fault. Layers with low friction coefficients and high internal friction angles formed detachment folds with thick hinges and thin limbs; conversely, layers with high friction coefficients and low internal friction angles created detachment folds with thick limbs and thin hinges. Application of the results to modelling of the Ahwaz anticline in the Dezful Embayment, SW Iran, was successful, and in general the modelled structure was consistent with that observed in the field.

V11-01 DEEP DORSAL VEIN BED PLICATION FOR VENTRAL PENILE CURVATURE

You have accessJournal of UrologyCME1 Apr 2023V11-01 DEEP DORSAL VEIN BED PLICATION FOR VENTRAL PENILE CURVATURE Pedro Caetano Edler Zandoná, Guilherme Garcia Barros, Igor Valente Coimbra, Plinio Moreira De Góes, Eduardo Zinoni Silva Pato, William Carlos Nahas, Bruno Chiesa Gouveia Nascimento, and Jorge Hallak Pedro Caetano Edler ZandonáPedro Caetano Edler Zandoná More articles by this author , Guilherme Garcia BarrosGuilherme Garcia Barros More articles by this author , Igor Valente CoimbraIgor Valente Coimbra More articles by this author , Plinio Moreira De GóesPlinio Moreira De Góes More articles by this author , Eduardo Zinoni Silva PatoEduardo Zinoni Silva Pato More articles by this author , William Carlos NahasWilliam Carlos Nahas More articles by this author , Bruno Chiesa Gouveia NascimentoBruno Chiesa Gouveia Nascimento More articles by this author , and Jorge HallakJorge Hallak More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003337.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Either Congenital Penile Curvature or Peyronie’s Disease may cause severe ventral curvature. Historically, surgical techniques for this type of deformities were associated with longer operative time and greater patient dissatisfaction, mainly due to neurovascular bundle (NVB) dissection [1]. Previous studies described a midline dorsal plication technique in pediatric patients, allowing for an effective correction without requiring NVB manipulation [2-5]. Neuroanatomical studies have demonstrated the distribution of nerve fibers and identified the 12 o'clock position as the only nerve-free position [2]. Finally, in 2021, Bagnara et al published the description of the Giammusso corporoplasty in adults [6]. We aim to demonstrate with this video article the step by step of this previously published technique for ventral penile curvature correction. METHODS: This video article is a compilation of images of three surgeries performed for ventral penile curvature utilizing an adaptation of the Giammusso Corporoplasty technique. In the main video, the procedure was performed for a 26-year old male with a 62-degree ventral congenital penile curvature. Supplementary photographs of other two cases were added to the video: a 77-year old male with a 68-degree Peyronie’s ventral curvature and a 29-year old male with a 28-degree ventral congenital penile curvature. In all cases, a subcoronal incision was performed, and penile skin and Dartos’ fascia were degloved. The point of maximum curvature was identified after a saline induced artificial erection, Buck’s fascia was incised, and deep dorsal vein and its branches were then dissected and ligated. Differently from the Giammusso technique, we did not perform a corporoplasty, but a simple plication as described by Akdemir et al [5]. This latter technique however spares the deep dorsal vein. For the plication, after planning and marking their sites with Allys clamp and artificial erection confirming functional alignment, we utilized 3 inverted non-absorbable 2-0 coated polyester sutures for each plication site. Circumcision was performed for penile shaft closure. RESULTS: The three patients shown in this video obtained functional penile alignment, and no change in glans sensation. No severe adverse event was observed, with one patient developing a small penile hematoma managed conservatively. CONCLUSIONS: This video article describes Deep Dorsal Vein Bed Plication, a feasible and effective technique for ventral penile curvature treatment, which avoids NVB dissection and its associated risks such as glans hypoesthesia and glans necrosis. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e999 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Pedro Caetano Edler Zandoná More articles by this author Guilherme Garcia Barros More articles by this author Igor Valente Coimbra More articles by this author Plinio Moreira De Góes More articles by this author Eduardo Zinoni Silva Pato More articles by this author William Carlos Nahas More articles by this author Bruno Chiesa Gouveia Nascimento More articles by this author Jorge Hallak More articles by this author Expand All Advertisement PDF downloadLoading ...

V11-12 MULTIPLE SLIT INCISIONS WITH TACHOSIL® GRAFTING FOR TREATMENT OF PEYRONIE'S DISEASE AND ED

You have accessJournal of UrologyCME1 Apr 2023V11-12 MULTIPLE SLIT INCISIONS WITH TACHOSIL® GRAFTING FOR TREATMENT OF PEYRONIE'S DISEASE AND ED Ahmed Ragheb and Daniar Osmonov Ahmed RaghebAhmed Ragheb More articles by this author and Daniar OsmonovDaniar Osmonov More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003337.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Plaque incision or partial excision with collagen fleece grafting and inflatable penile prosthesis (IPP) implantation is a well-established treatment for severe penile curvatures associated with ED. Nevertheless, multiple plaque incisions combined with Tachosil® grafting may have added advantages. We demonstrate step-by-step the treatment of a case of severe ED with an over 60 degree dorsal curvature mainly on the left side and an hour glass indentation on the right side of the penile shaft. We highlight the advantages of multiple plaque incisions and Tachosil® grafting combined with IPP implantation for these specific cases. METHODS: After IPP implantation via the penoscrotal approach, the neurovascular bundle was mobilized. For the left sided curvature we underwent multiple deep transverse slits starting from and around the point of maximum curvature using a low energy cutting current (20 to 30 Watts). Our transverse incisions were complimented with the modeling technique. For the right sided waist formation we underwent longitudinal slits. The area of incisions was covered by a Tachosil® graft. RESULTS: The multiple horizontal incisions led to a vertical release thus straightening of the curved penile shaft. Longitudinal slits led to a horizontal release, therefore expanding and obliterating the waist formation. CONCLUSIONS: The multiple slit technique together with Tachosil® grafting may have added advantages compared to the conventional plaque incision/excision utilizing the same graft. The smaller defects created by the multiple tunical incisions may avoid potential cylinder protrusion, facilitate better sealing of the collagen fleece, lower the incidence of hematoma and/or infections and allow complimentary modeling of the penis. Moreover, complex deformities may also be treated simultaneously with success. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1002 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ahmed Ragheb More articles by this author Daniar Osmonov More articles by this author Expand All Advertisement PDF downloadLoading ...

Analytical solutions of the magnetic and stress fields on a soft ferromagnetic material containing a smooth rigid inclusion in two-dimensional space

The analytical investigations on a rigid inclusion embedded in a soft ferromagnetic material in two-dimensional space subjected to uniform magnetic load at infinity have been carried out, with the magnetic insulation boundary of the rigid inclusion. In our study, explicit solutions of the magnetic and stress fields are obtained based on linear magnetoelastic theory and complex variable theory. The relative rigid-body displacement of the rigid inclusion is considered to ensure the boundary condition and constraint satisfied accurately. It is found that the analytic solutions of Kolosov-Muskhelishvili (K-M) potentials have a compact form when the shape of rigid inclusion is characterized by Laurent polynomial with finite terms. As examples, the rigid-body displacement, magnetic flux and stress on the boundary of elliptic and polygonal rigid inclusions are analyzed, respectively. Our results show that the rigid-body displacement caused by a non-strong magnetic load is small, while the orientation and contour curvature of the rigid inclusions have significant effects on the distribution of the stress and magnetic flux fields. In addition, the maximum magnetic flux and maximum stress do not always occur at the maximum curvature point. For polygonal rigid inclusions, the orientations in which the extreme concentration is obtained are closely related to the number of tips of the inclusions.

Photovoltaic single-diode model parametrization. An application to the calculus of the Euclidean distance to an [formula omitted]–[formula omitted] curve

In this paper we provide a new parametrization of the characteristic curve (I-V curve) associated to the photovoltaic (PV) single-diode model (SDM), which is the most common model in the literature to analyze the behavior of a PV panel. The SDM relates the voltage with the current, through a transcendental equation with five parameters to be determined. There are many methodologies to extract the SDM parameters and some of them are based on obtaining the best fit of the SDM model on a voltage–current dataset through the ordinary least squares method. However, the fact that errors affect not only the current but also the voltage indicates that the maximum likelihood estimation (MLE) of the parameters is obtained by the total least squares method, also called orthogonal distance regression (ODR). The main difficulty in performing ODR lies in obtaining the Euclidean distance from a point to the SDM I-V curve which is in general a hard mathematical problem; in our particular case it is noticeably more difficult due to the implicit nature of the SDM equation and the fact that solution candidates might not be unique. This paper proposes a new parametrization that allows reduction of the calculus of the Euclidean distance from any point to the I-V curve to solving a single-variable equation. An in-depth mathematical analysis determines the number of possible candidates where the Euclidean distance can be attained. Moreover, a full casuistry alongside a geometrical study based on the curvature of the I-V curve and the Maximum Curvature Point, permits identification and classification of all these candidates. This enables for the first time a complete algorithm to compute the Euclidean distance from a point to an I-V curve at any condition and, thus, to perform a reliable ODR to obtain the MLE of the SDM parameters. Using the obtained theoretical background, it is demonstrated that two existing methodologies to compute the Euclidean distance fail in some cases, whereas the proposed algorithm is execution-proof and runs faster.