Reconstruction of Membranous Urethral Strictures

Purpose of Review

Due to the proximity of the rhabdosphincter and cavernous nerves to the membranous urethra, reconstruction of membranous urethral stricture implies a risk of urinary incontinence and erectile dysfunction. To avoid these complications, endoscopic management of membranous urethral strictures is traditionally favored, and bulboprostatic anastomosis is reserved as the main classical approach for open reconstruction of recalcitrant membranous urethral stricture. The preference for the anastomotic urethroplasty among reconstructive urologists is likely influenced by the familiarity and experience with trauma-related injuries. We review the literature focusing on the anatomy of membranous urethra and on the evolution of treatments for membranous urethral strictures.

Recent Findings

Non-traumatic strictures affecting bulbomembranous urethra are typically sequelae of instrumentation, transurethral resection of the prostate, prostate cancer treatment, and pelvic irradiation. Being a different entity from trauma-related injuries where urethra is not in continuity, a new understanding of membranous urethral anatomy is necessary for the development of novel reconstruction techniques. Although efficacious and durable to achieve urethral patency, classical bulboprostatic anastomosis carries a risk of de-novo incontinence and impotence. Newer and relatively less invasive reconstructive alternatives include bulbar vessel-sparing intra-sphincteric bulboprostatic anastomosis and buccal mucosa graft augmented membranous urethroplasty techniques. The accumulated experience with these techniques is relatively scarce, but several published series present promising results. These approaches are especially indicated in patients with previous transurethral resection of the prostate in which sparing of rhabdosphincter and the cavernous nerves is important in attempt to preserve continence and potency. Additionally, introduction of buccal mucosa onlay grafts could be especially beneficial in radiation-induced strictures to avoid transection of the sphincter in continent patients, and to preserve the blood supply to the urethra for incontinent patients who will require artificial urinary sphincter placement. The evidence regarding erectile functional outcomes is less solid and this item should be furtherly investigated.

     

One-year clinical and angiographic follow-up after primary stenting

INTRODUCTION AND OBJECTIVES: The late reocclusion or restenosis rate of the infarct related artery is frequent after primary angioplasty. An implanted stent may be able to improve the coronary angioplasty results and long-term outcome of these patients. We present the clinical and angiographic outcome of a cohort of patients treated with primary stenting. PATIENTS AND METHODS: A group of 74 consecutive patients with acute myocardial infarction treated with primary angioplasty and stenting were followed for one year. An angiographic control was performed at the 6th month of follow-up in 91% of patients to assess the restenosis and reocclusion rates of the infarct-related artery. RESULTS: There were eight in-hospital deaths and three during follow-up (mortality rate 14.8%) and one non-fatal reinfarction (1.5%). The cumulative rate of recurrent ischemia was 6% at 3 months and 15% at 6 months, without any further increment at one-year follow-up. A new angioplasty was performed in 7 patients and three patients underwent surgical revascularization. Thus 80% of patients after discharge were free of events. The angiographic control showed only one reocclusion of the infarct related artery and a restenosis rate of 27%. CONCLUSIONS: These results show that primary stenting is an effective procedure in treating non-selected patients with acute myocardial infarction with a low long-term incidence of adverse events and a low restenosis rate.     

The Chemokine MIG is Associated with an Increased Risk of COVID-19 Mortality in Mexican Patients

Background: Coronavirus disease 2019 (COVID-19) is an emergent viral disease in which the host inflammatory response modulates the clinical outcome. Severe outcomes are associated with an exacerbation of inflammation in which chemokines play an important role as the attractants of immune cells to the tissues.Objective: To evaluate the relationship of the chemokines IL-8, RANTES, MIG, MCP-1, and IP-10 with COVID-19 severity and outcomes in Mexican patients.Methods: We analyzed the serum levels of IL-8, RANTES, MIG, MCP-1 and IP-10 in 148 COVID-19 hospitalized patients classified as mild (n=20), severe (n=61), and critical (n=67), as well as in healthy individuals (n=10), by flow cytometry bead array assay.Results: Chemokine levels were higher in patients than in the healthy individuals, but only MIG, MCP-1, and IP-10 increased according to the disease severity, showing the highest levels in the critical group. MIG, MCP-1, and IP-10 levels were also higher in COVID-19 patients with comorbidities such as renal disease, type 2 diabetes, and hypertension. Moreover, elevated MIG levels seem to be related to organic failure/shock, and an increased risk of death.Conclusions: Our results suggest that the increased levels of MCP-1, IP-10, and especially MIG might be useful in predicting severe COVID-19 outcomes and could be promising therapeutic targets.     

Des‐Acyl Ghrelin Directly Targets the Arcuate Nucleus in a Ghrelin‐Receptor Independent Manner and Impairs the Orexigenic Effect of Ghrelin

Ghrelin is a stomach‐derived octanoylated peptide hormone that plays a variety of well‐established biological roles acting via its specific receptor known as growth hormone secretagogue receptor (GHSR). In plasma, a des‐octanoylated form of ghrelin, named des‐acyl ghrelin (DAG), also exists. DAG is suggested to be a signalling molecule that has specific targets, including the brain, and regulates some physiological functions. However, no specific receptor for DAG has been reported until now, and, consequently, the potential role of DAG as a hormone has remained a matter of debate. In the present study, we show that DAG specifically binds to and acts on a subset of arcuate nucleus (ARC) cells in a GHSR‐independent manner. ARC cells labelled by a DAG fluorescent tracer include the neuropeptide Y (NPY) and non‐NPY neurones. Given the well‐established role of the ARC in appetite regulation, we tested the effect of centrally administered DAG on food intake. We found that DAG failed to affect dark phase feeding, as well as food intake, after a starvation period; however, it impaired the orexigenic actions of peripherally administered ghrelin. Thus, we conclude that DAG directly targets ARC neurones and antagonises the orexigenic effects of peripherally administered ghrelin.     

Role of echocardiography in the diagnosis of aortic dissection

We evaluated sensitivity, specificity and predictive values of echocardiography in detecting aortic dissection. We studied in the same period of time two groups of consecutive patients with good quality echocardiographic examination. Group I, with high prevalence of the disease (76%), was composed of 25 patients; 19 patients with aortic dissection (11 of the type A and 8 of the type B) and 6 patients with clinical and echocardiographic suggestion of aortic dissection which was not confirmed by angiography. Group II, with lower prevalence of the disease (4%), was composed of 382 adult patients who underwent aortic angiography for different reasons. In this second group there were 16 out of the 19 patients of the first group, with aortic dissection, who underwent aortic angiography and the 6 patients with suspicion of aortic dissection which was not confirmed by angiography. Type A dissection: The finding of intimal flap on echocardiography was highly specific (98%) but relatively insensitive (45%); its positive predictive value was low (50% in the first and 34% in the second group). The specificity of increased thickness of aortic wall was lower (89%) and the sensitivity higher (81%); its positive predictive value was satisfactory in the first group (81%) and very low in the second (13%). Aortic root dilatation was fairly specific (76%); the sensitivity of this finding was high (87%) but its positive predictive value was still low (66% in the first and 7% in the second group). To conclude: the positive predictive value of the 3 echocardiographic signs of aortic dissection varied, in relation to the different prevalence of the disease, from 50, 81 and 66% in the first group to 34, 13 and 7% in the second group; the diagnostic utility of the echocardiographic examination appeared limited, in these patients, by the low values of sensitivity and positive predictive values; aortography is still the most valuable technique in the diagnosis of aortic dissection; echocardiography was useful in the early evaluation of some emergency cases (chest pain, shock, collapse...) suggesting sometimes the correct diagnostic hypothesis of aortic dissection; in the presence of a typical clinical picture, the contemporary presence of the 3 echocardiographic signs, though having the lowest sensitivity (36%), was highly predictive of the type A dissection. Type B dissection: In these patients the clinical picture, in contrast with type A dissection, Type A, was not indicating careful and complete echocardiographic aortic scan. Then the echocardiographic examination was even more disappointing: sensitivity 25%.     

CarboMedics Mitroflow pericardial aortic bioprosthesis - performance in patients aged 60 years and older after 15 years

BACKGROUND: The purpose of this study was to carry out a current assessment of the Mitroflow pericardial bioprosthesis (model 11) according to the durability of the prosthesis after 15 years in patients aged 60 years or older. METHODS: This bioprosthesis was implanted in 161 patients (mean age 69.5 +/- 6.3 years; range 60 - 94 years) undergoing aortic valve replacement (AVR) between 1982 and 1992. There were 84 patients aged 60 - 69 years (mean 64.5 +/- 3.1years) and 77 patients aged 70 years or older (mean 74.8 +/- 4.3 years). Of the total population, concomitant procedures were performed in 63 patients (39.1 %); of these, coronary artery bypass grafting was performed in 39 (24.2 %). RESULTS: Early mortality was 4.8 % (4 patients) in the 60 - 69 year age group and 10.4 % (8) in patients aged 70 years or older ( P = 0.290). Late mortality was 4.5 %/patient-year (35) for those aged 60 - 69 years and 8.1 %/patient-year (49) for those aged 70 years or older ( P = 0.007). Patient survival at 15 years of patients aged 60 - 69 years was 47.6 +/- 6.3 % and of patients aged 70 years or older was 20.9 +/- 5.4 % ( P = 0.003) ( ). Freedom from valve-related mortality for patients in the 60 - 69 year age group was 92.1 +/- 3.5 % at 15 years (0.6 %/patient-year [5]), and in the patient group aged 70 years or older it was 84.4 +/- 5.3 % (1.3 %/patient-year [8]; P = 0.194). Freedom from reoperation for patients in the 60 - 69 year age group was 73.9 +/- 5.0 % (2.6 %/patient-year [20]), and for patients aged 70 years or older it was 91.4 +/- 3.4 % (1.0 %/patient-year [6]; P = 0.029). The structural valve deterioration (SVD) rate for patients in the 60 - 69 year age group was 2.4 %/patient-year (19), and for patients aged 70 years or older it was 1.0 %/patient-year (6) ( P = 0.041). Actuarial freedom from structural valve deterioration at 15 years for patients aged 60 - 69 years was 62.0 +/- 7.3 %, and 80.8 +/- 7.9 % for patients aged 70 years and older ( P = 0.049) (actual freedom 73.9 +/- 5.2 % and 91.4 +/- 3.4 %, respectively). CONCLUSIONS: The Mitroflow pericardial bioprosthesis can still be recommended for aortic valve replacement in patients 70 years and older.     

Development and Evaluation of a Head-Controlled Human-Computer Interface with Mouse-Like Functions for Physically Disabled Users

OBJECTIVES

The objectives of this study were to develop a pointing device controlled by head movement that had the same functions as a conventional mouse and to evaluate the performance of the proposed device when operated by quadriplegic users.

METHODS

Ten individuals with cervical spinal cord injury participated in functional evaluations of the developed pointing device. The device consisted of a video camera, computer software, and a target attached to the front part of a cap, which was placed on the user’s head. The software captured images of the target coming from the video camera and processed them with the aim of determining the displacement from the center of the target and correlating this with the movement of the computer cursor. Evaluation of the interaction between each user and the proposed device was carried out using 24 multidirectional tests with two degrees of difficulty.

RESULTS

According to the parameters of mean throughput and movement time, no statistically significant differences were observed between the repetitions of the tests for either of the studied levels of difficulty.

CONCLUSIONS

The developed pointing device adequately emulates the movement functions of the computer cursor. It is easy to use and can be learned quickly when operated by quadriplegic individuals.     

Population pharmacokinetics of levofloxacin, gatifloxacin, and moxifloxacin in adults with pulmonary tuberculosis

The objective of this study was to determine the population pharmacokinetic parameters of levofloxacin, gatifloxacin, and moxifloxacin following multiple oral doses. Twenty-nine patients with tuberculosis at the University Hospital in Vitória, Brazil, participated. Subjects received multiple doses of one drug (levofloxacin, 1,000 mg daily, or gatifloxacin or moxifloxacin, 400 mg daily) as part of a 7-day study of early bactericidal activity. Serum samples were collected over 24 h after the fifth dose and assayed using validated high-performance liquid chromatography assays. Concentration-time data were analyzed using noncompartmental, compartmental, and population methods. The three drugs were well tolerated. Levofloxacin produced the highest maximum plasma concentrations (median, 15.55 microg/ml; gatifloxacin, 4.75 microg/ml; moxifloxacin, 6.13 microg/ml), largest volume of distribution (median, 81 liters; gatifloxacin, 79 liters; moxifloxacin, 63 liters), and longest elimination half-life (median, 7.4 h; gatifloxacin, 5.0 h; moxifloxacin, 6.5 h). A one-compartment model, with or without weight as a covariate, adequately described the data. Postmodeling simulations using median population parameter estimates closely approximated the median values from the original data. Area under the concentration-time curve/MIC ratios for free drug were high. All three quinolones showed favorable pharmacokinetic and pharmacodynamic indices, with the most favorable results in this population being seen with levofloxacin at the comparative doses used.