Methods for measuring crystallization in urolithiasis research: why, how and when?

Whereas crystalluria does not distinguish between kidney stone formers and healthy people and thus can be considered a physiologic event, kidney stone formation is a pathologic incident and reflects a specific form of biomineralization. Both single urinary crystals as well as whole kidney stones form under exquisite control of organic macromolecules. Simple crystal formation in the urinary tract is distinguished from stone formation in the kidney by the process of particle retention. The latter occurs either because nucleated crystals strongly aggregate to particles too large to pass freely through the tubules ('free particle' theory), or because crystals become abnormally adherent to tubular cell surfaces ('fixed particle' theory). Since it is impossible to mimic all the processes involved in stone formation in vitro, it is highly important to carefully chose a specific crystallization process for in vitro studies, and to select the most appropriate experimental conditions for measuring the chosen process as reliably as possible. This overview aims at critically reviewing the principles of currently available assay systems for studying crystallization processes involved in stone formation. Consensus is reached by the experts that no in vitro system really mimics what happens in renal stone formation, but that carefully designed in vitro studies will always play an important part in urolithiasis research. For such studies, it is highly important to exactly control the appropriate experimental conditions that are relevant to a specific crystallization process under investigation. Practical guidelines for researchers working with crystallization systems are provided, and it is concluded that international efforts should be made to standardize the terminology, to agree on a set of basic experimental parameters (temperature, pH, artificial urine composition), and to adopt simple tests or conditions are reference points for quality and comparative control.     

Non invasive ventilation: how, when and why?

Use of non invasive ventilation (NIV), the delivery of mechanical ventilation without endotracheal intubation, is increasing among patients with acute and chronic respiratory failure, mainly because of its convenience, lower cost, morbidity sparing potential compared with standard invasive technique. An understanding of the technical equipment, the classification, modes of ventilation and the selection of an appropriate interface are necessary for the best outcomes. The parameters which should be monitored during noninvasive ventilation are presented. The majority of studies have used pressure-targeted ventilation in the assist mode. Positive qualities of pressure support ventilation (PSV) are leak compensation, good patient/ventilator synchrony and the option of integrated positive end-expiratory pressure to counteract the effect of dynamic hyperinflation. The interface between patient and ventilator is a crucial issue of noninvasive ventilation. Advantages and disadvantages of face and nasal masks are discussed. The beneficial effects of NIV have been demonstrated in patients with respiratory acidosis (pH < 7.35). Arterial blood gas tensions should be measured in most patients with acute breathlessness.     

Publishing in surgery: how and why?

Introduction

Evidence-based medicine continues to have an increasingly important impact on all surgical departments, with the art of publication becoming a skill in its own right and occupying an ever more central role. However, it remains a challenge for any surgeon to publish their work.

Purpose

The aims of this educational review are to understand why, what and where surgeons should publish and to provide surgeons with a guide regarding the publication process and the rules to be adhered to.

Methodology

This review targets (1) any surgeon beginning their scientific publication activity, (2) more experienced surgeons who wish to optimise their ability to have their work published and finally (3) leaders of research departments who aspire to improve the quality of their publications and their research productivity and profile.     

Vena cava filters: why, when, what and how?

Filter or without filter? If yes, which one should be chosen? These two questions represent one of the most passionate debates since almost 60 years in the treatment of the thromboembolic disease. The debates are not closed since besides some exceptions (until now only one randomized study) the literature remains poor in large studies and the decision is often taken taking into account personal convictions. This article proposes to make a state of the art about caval filtration, while reminding that cava filters remain only an additional tool in the prevention of pulmonary embolism (PE) and the decision of filtering a patient must be taken individually within a multidisciplinary team. All the previous opinions concerning caval filtration were disrupted by the arrival in the 1990s of a new type of vena cava filter: the optional filters or with retrieval option which allow to prevent the appearance of a PE during a more or less long time and which can be retrieved from the patient, thus avoiding the long-term complications of the cava filters. Still they can be left in place as permanent filter if necessary. After analyzing the pros and cons for the caval filtration, the Authors suggest some orientations for the future, mainly concerning the indications of primary prophylaxis. Until now the ideal filter does not exist, but even if it existed, it should be able to disappear at the right moment, without a new potentially aggressive procedure.     

Redo surgery for carotid artery stenosis: when and how?

PURPOSE: We analyzed operations performed at our institution retrospectively for recurrent carotid artery stenosis to assess the indication for surgery. We also assessed the techniques used for these operations. PATIENTS AND METHODS: From January 1992 to December 1998 1210 carotid endarterectomies were performed. Forty two (3.4%) of these were for recurrent stenosis. A new vein patch was implanted in 27 cases, PTFE patches were used in nine cases. In six cases an interposition with the great saphenous vein was performed. RESULTS: The mean interval between primary and secondary procedure was 60. 2months (3months to 23yr). Twenty five of our 41 patients had had ipsilateral neurologic symptoms before redo surgery, the remainder were free of symptoms. The grade of stenosis was over 90% in 22 cases, between 75 and 90% in 11 cases and below 75% in nine cases, two cases had aneurysmatic lesions. None of the patients died in the 30day observation period. One patient had a stroke with a permanent neurological deficit. In two cases postoperative bleeding occurred requiring reexploration. Two patients developed hypoglossal neurapraxia and in four patients the recurrent laryngeal nerve was injured. One patient had an apneic episode in the recovery room. CONCLUSION: The reported incidence of recurrent carotid artery stenosis surgery ranges from 3 to 36% and our incidence is at the lower end of this range. The surgical results of reoperating are acceptable with a low incidence of complications.     

Breast education for schoolgirls; why,what, when,and how?

Schools are fundamental settings for health education and adolescent females are an important group for promoting positive breast habits. We surveyed 2089 schoolgirls (11‐18 years) to provide evidence for, and guidance on, breast education for schoolgirls. 26% reported negative feelings about their breasts and 87% reported ≥ one breast concern. 72% wanted to know more about breast cancer (69% rating this extremely important). >50% wanted to know more about breast sag and breast pain. Preferred delivery format was age eleven (50%), girls only taught sessions (41%) with female teachers (43%). A need for breast education and delivery preferences was identified.     

Pectus bar removal – why,when, where and how

ObjectiveDespite its less invasive nature, the widespread use of the minimally invasive repair of pectus excavatum (MIRPE) procedure has been associated with a significant number of serious complications. On the other hand, Pectus bar removal (PBR) is often considered a simple procedure and often scheduled in an outpatient setting. However, several studies report near-fatal complications not only during bar placement, but also during bar removal. The aim of our study was to clarify why a pectus bar should be removed, timing for removal, where PBR should be performed, and overall setup for safe removal.MethodsA comprehensive review was performed in accordance with PRISMA guidelines, searching for articles published since 1998 in English. “Pectus bar removal AND (near-fatal) complications” were the applied terms. Inclusion criteria were articles reporting on the focus of PBR after MIRPE. Eligible study designs included (retrospective) case study series, case report and reviews. Full-text articles in which the technique in general was described were omitted.ResultsRecently published results of an online survey raised awareness about type and number of possible complications during PBR. Furthermore, our comprehensive literature review identified only a few, but serious complications during PBR.ConclusionsPBR has a high safety profile but in rare cases may be associated with major complications such as life-threatening hemorrhage from various thoracic sources. This risk is higher in patients with a history of complex MIPRE. In an effort to decrease these complications we recommend bilateral opening of surgical incisions, unbending the bar and meticulous mobilization of the bar. To manage these complications if they occur, we recommend removal in a hospital setting with adequate resources and personal including cardiac surgeons. If the postoperative course is uneventful discharge on the same day is reasonable.     

Untreated subarachnoid hemorrhage: who, why, and when?

OBJECT: When subarachnoid hemorrhage (SAH) is caused by an aneurysm or other vascular anomaly, surgery or endovascular treatment is generally indicated. Nevertheless, some patients with SAH do not receive such therapy. The objective of this study was to characterize the patients who do not receive treatment. METHODS: The records of all patients with SAH who were admitted to a tertiary care center during a 9-year period were retrospectively reviewed. Untreated patients were classified into one of three groups based on angiographic results. Demographic, clinical, and neuroimaging findings and outcomes were compared between these three groups and between treated and untreated patients. Definitive treatment of SAH was provided in 477 patients and 166 were untreated. Untreated patients were older, had a worse neurological status on presentation, and a higher mortality rate (43.4% compared with 11.7%). Among these, 76 had normal angiographic results and a low mortality rate (6.6%). Fifty-two patients in whom no cerebral angiogram was obtained (mostly because of their neurological condition) had the highest mortality rate (92.3%). Of 38 patients with abnormal angiographic results 50% died, mostly due to rebleeding. Among elderly patients or those with a severe neurological deficit, outcome was significantly better in the ones who were treated. CONCLUSIONS: A significant proportion of patients who were admitted with SAH did not receive definitive therapy. Major reasons for this included normal results on angiographic studies and poor clinical grade. Untreated patients with normal angiographic results had a good outcome, whereas those in whom angiography was not performed and those with abnormal angiographic results had a high mortality rate from the consequences of the initial hemorrhage in the first instance or rebleeding in the second. Although among elderly patients and those with a poor clinical grade the mortality rate was lower among those who received treatment, a definitive conclusion favoring treatment in these high-risk groups can only be drawn from a prospective randomized study.     

Perioperative antibiotics: when, why?

The use of prophylactic antibiotics in general thoracic surgery is well established. This article explains the rationale for modern-day surgical wound infection prophylaxis, the why and the when. Various arguments about the use of antibiotics to prevent empyema and pneumonia after a thoracic operation also are presented.     

Rectocele repair: when and how?

Pelvic organ prolapse repair poses a unique challenge to the reconstructive pelvic surgeon. Traditional levator plication has been promoted for the past century and has recently been shown to create unsatisfactory functional results, among them dyspareunia. In an attempt to improve both functional and quality-of-life outcomes, new methods for posterior vaginal wall defect repair have been developed and are now undergoing critical evaluation. We present a review of posterior vaginal wall repair with a focus on new anatomic concepts and site-specific rectocele repair.