Kristalloide versus Kolloide A never ending story?

Ohne Zusammenfassung     

Learning curve of microvascular venous anastomosis: a never ending struggle?

In this study, a simple protocol based on the rat femoral venous anastomosis was established to provide a quantitative representation of the progress. The learning curve is based on the patency rate in each consecutive group of five anastomoses. Two groups of surgeons were observed. The inexperienced group encountered a tough time in the first 25 anastomoses. However, the progress was fast and is represented by the steep slope of the curve. A plateau was reached whereby the avearge patency rate matches that of the experienced group. As expected, there was no learning curve for the experienced group. Despite every effort to attempt to maintain a perfect 100% patency on this model, the best achievable patency was only 88%. The results and its implication are discussed.     

The lipid story in chronic kidney disease: a long story with a happy end?

Cardiovascular (CV) morbidity and mortality increase with the severity of kidney disease, reaching 30 times higher mortality rates in dialysis patients compared with the general population. Although dyslipidemia is a well-established CV risk factor in the general population, the relationship between lipid disorders and CV risk in patients with chronic kidney disease (CKD) is less clear. Despite the clear evidence that statins reduce the risk of atherosclerotic events and death from cardiac causes in individuals without CKD, the use of statins in patients with kidney disease is significantly less frequent. For a long time, one of the explanations was the lack of a prospective, randomized, controlled study designed specifically to CKD patients. After recent publication of the data from Study of Heart and Renal Protection trial, given the safety and potential efficacy of statins, this lipid-lowering treatment should be administered more frequently to individuals with CKD stage 1–4, as well as those undergoing dialysis.     

A critical look at diagnostic criteria: time for a change?

There are certain thought barriers involved in making diagnostic-classification criteria in diseases of unknown origin. Among these are a lack of appreciation of the issue of circular logic, the basic oneness of diagnostic and classification criteria, the lack of appreciation as to why we make such criteria in the first place, and the lack of importance informing our patients that we do as well as should treat them without a frm diagnosis in many instances. The relevance of these thought barriers to the new American College of Rheumatology/European Union League Against Rheumatism (ACR/EULAR) Rheumatoid Arthritis (RA) classification criteria are also discussed.     

Desmoid tumour following a distal radius fracture – a complication or a coincidence?

We describe a case of a desmoid tumour occurring 15 months following an uncomplicated fracture of the left distal radius. The occurrence of a desmoid tumour after fracture is extremely rare and a Medline search revealed only two previous reports. The correlation between the site of trauma and the tumour and the time interval between trauma and presentation strongly supports a causal role of the fracture in the occurrence of this tumour.     

Is it safe to use a kidney from an expanded criteria donor?

Background

The use of expanded criteria donor (ECD) kidneys has been encouraged to enlarge the donor pools due to the shortage of donors. However, a major concern with ECD kidneys is poor long-term graft survival. The objective of this study was to determine whether ECD kidneys had a negative impact on graft survival.

Methods

We analyzed all deceased donor renal transplantations at our center from September 1995 to December 2009.

Results

ECD donors show characteristics, such as comparatively older age, a history of hypertension and diabetes, the use of norepinephrine, high serum creatinine levels and deceased donor scores, and decreased albumin levels and estimated glomerular filtration rates. However, the occurrence of delayed graft function and primary nonfunction among ECD grafts was comparable to those of standard criteria donor (SCD) grafts. Graft survival was not significantly different between the two groups. Only serum creatinine levels at 3, 6, and 9 months after transplantation were lower in the ECD than the SCD group. Multivariate analysis identified longer hospital stay after transplantation, delayed graft function, and acute rejection episodes as independent predictors of poor graft survival.

Conclusion

Graft survival of ECD kidney was comparable to that of SCD kidneys. We observed that donor factors prior to procurement were not risk factors for graft failure.     

The individual patient and evidence-based medicine – a conflict?

The doctor–patient relationship is characterised by clinical situations that reflect different degrees of impairment of the patient’s quality of life on the one hand and different degrees of threat to the patient’s life on the other. Typical patterns of these situations from absent or minimal to severe impairment of well being or threat to life are described. With regard to this, the doctor–patient communication is still suffering from considerable deficits. For the latter, a possible philosophical framework and reason is given. The potential of evidence-based medicine to ease this conflict by bringing into the game the current best-available scientific evidence is discussed, and some inherent serious limitations of evidence-based medicine are shown. Besides these drawbacks, doctors are usually very reluctant and lazy to integrate evidence-based results into their daily practice. In the author’s view, evidence-based medicine is a reasonably new tool. However, it should not yet be overestimated in its potential to influence and improve daily clinical practice. Received: 9 March 1999 Accepted: 2 September 1999     

Carotid artery stenting: is there a need to revise ultrasound velocity criteria?

OBJECTIVES: Ultrasound (US) velocity criteria have not been well-established for patients undergoing carotid artery stenting (CAS). A potential source of error in using US after CAS is that reduced compliance in the stented artery may result in elevated velocity relative to the native artery. We measured arterial compliance in the stented artery, and developed customized velocity criteria for use early after CAS. METHODS: US was performed before and within 3 days after CAS, and after 1 month in a subset of 26 patients. Post-procedural peak systolic velocity (PSV) and end-diastolic velocity (EDV) of the internal carotid artery (ICA), PSV/EDV ratio, and internal carotid artery to common carotid artery ratio (ICA/CCA) were recorded. These were compared with degree of in-stent residual stenosis determined at carotid angiography performed at the completion of CAS. Peterson's elastic modulus (Ep) and compliance (Cp) of the ICA were determined in a subgroup of 20 patients at the distal end of the stent and in the same region in the native ICA before stenting. RESULTS: Ninety CAS procedures were analyzed. Mean (+/-SD) angiographic residual stenosis after CAS was 5.4 +/- 9.1%, whereas corresponding PSV by US was 120.4 +/- 32.4 cm/s; EDV, 41.4 +/- 18.6 cm/s; PSV/EDV ratio, 3.3 +/- 1.2; and ICA/CCA ratio, 1.6 +/- 0.5. PSV was unchanged at 1 month. Post-CAS PSV and ICA/CCA ratio correlated most with degree of stenosis (P <.0001 for both). Only six patients demonstrated in-stent residual stenosis 20% or greater, but the standard US threshold of PSV 130 cm/s or greater (validated for >20% ICA stenosis in our laboratory) categorized 38 of 90 patients as having stenosis 20% or greater. Receiver operator curve analysis demonstrated that a combined threshold of PSV 150 cm/s or greater and ICA/CCA ratio 2.16 or greater were optimal for detecting residual stenosis of 20% or greater, with sensitivity 100%, specificity 98%, positive predictive value 75%, and negative predictive value 100%. After placement of a stent, the ICA demonstrated significantly increased Ep (1.2 vs 4.4 x 10(3) mm Hg; P =.004) and decreased Cp (9.8 vs 3.2 %mm Hg x 10(-2); P =.0004). CONCLUSIONS: Currently accepted US velocity criteria validated in our laboratory for nonstented ICAs falsely classified several stented ICAs with normal diameter on carotid angiograms as having residual in-stent stenosis 20% or greater. We propose a new criterion that defines PSV less than 150 cm/s, with ICA/CCA ratio less than 2.16, as the best correlate to a normal lumen (0%-19% stenosis) in the recently stented ICA. This was associated with increased stiffness of the stented ICA (increased Ep, decreased Cp). These preliminary results suggest that placement of a stent in the carotid artery alters its biomechanical properties, which may cause an increase in US velocity measurements in the absence of a technical error or residual stenotic disease.     

Mitral regurgitation – evaluation of a multidimensional echocardiographic grading system. A study on 177 patients with chronic primary and secondary mitral regurgitation

Introduction.In grading mitral regurgitation (MR) magnetic resonance imaging is the gold standard but 2D echo is mostly used in clinical practice. However, each single echo parameter is prone to confounding influences. With regard to chronic primary and secondary MR the purpose of this study was to compare a new multi-dimensional echo-based grading system with an independent pre-operatively used invasive standard. Methods. In a retrospective study we analyzed 177 patients with different degrees of MR severity, who were examined both by echocardiography and by cardiac catheterization. For MR grading a combination of four echocardiographic parameters was used: density of the regurgitation velocity profile, peak mitral inflow velocity (Vmax E-wave), radius of the proximal flow convergence zone (PISA), and vena contracta (Vc) width. Invasive grading was based on left ventriculography (Seller's method), V wave hight, and regurgitation fraction. Both methods resulted in an integrative score on an eight point scale (<I-IV in half-steps). Echocardiographic and invasive data were correlated. Results. There was a reasonable overall correlation of r = 0.72 (p = 0.001) between both grading systems. Echo tended to slightly overestimate MR severity. In patients with secondary MR, agreement was worse (p = 0.01) than in primary MR. The most powerful single echo parameter was Vc r = 0.71 (p = 0.001). Presence or absence of sinus rhythm had no significant influence on echo grading. Conclusions. The proposed echocardiographic multidimensional MR grading system is feasable and shows good correlation with invasive grading.     

Central K-wire and PDS-Cord for Acromioclavicular separations – a successful treatment?

Beside the basic question wether a separation of the acromioclavicular joint should be treated operatively or not, the method of operation is discussed in particular. For that reason we investigated our own method of a temporary transfixation of the joint by a centrally drilled K-wire combined with a PDS-augmentation of the coracoclavicular and a suture of the acromioclavicular ligament. Follow up examinations were possible in 57 out of 82 patients which were operated during 5 years. Patients subjective rating and objective follow up and sonographically evaluated joint conditions were scored together. Looking for the range of motion of the shoulder only 5.5% of the patients had a reduction of more than 20 degrees. Out of 12 complications in particular three infections only resulted satisfying by influencing the subjective rating negatively. In 28.1% of patients no durable anatomic reconstruction of the joint was achieved. Score achieved by these patients was significantly lower compared to those with a lasting anatomic reconstruction of the acromioclavicular joint. In conclusion the results confirm our operative regime for separations of the acromioclavicular joint. In literature survey the here described method of operation belongs to the better ones without showing a clear advantage. Nevertheless the method should be modified to decrease the rate of subluxations.     

Can histopathology predict treatment outcome following high-energy transurethral microwave thermotherapy of the prostate? Results of a biopsy study.

BACKGROUND: Despite good results of high-energy transurethral microwave thermotherapy (TUMT) in the treatment of benign prostatic hyperplasia, it is still difficult to predict the response to treatment on an individual basis. Besides clinical baseline parameters, intrinsic histological parameters are suggested to play a role in the response variance after TUMT. In this study we analyzed histological parameters (vessel density and epithelium-stroma (E/S) ratio) in patients who were selected for high-energy TUMT and related these parameters to clinical outcome. METHODS: We treated 42 patients with high-energy TUMT, who prior to treatment agreed upon ultrasonographic investigation of the prostate in combination with biopsies of the peripheral and transitional zones of the prostate. For all separate biopsy locations, the histological stained prostate slides were morphometrically quantified with computer assistance and analyzed for E/S ratio and vessel density. Response to treatment was measured by using standardized response evaluation criteria and was correlated with histological outcome. RESULTS: The E/S ratio in the inner gland biopsies tended to be higher in the good response group compared to the very poor responders. Furthermore, a clear trend was seen towards a lower vessel density in good responders. Large prostates and prostates with a high E/S ratio responded well to the high-energy thermotherapy. CONCLUSIONS: Histopathological parameters of the prostate tend to be moderately predictive for clinical response in this research population. Poor responders appeared to have a somewhat higher vessel density in all prostate biopsy sides, and there was also a trend towards a lower E/S ratio in these patients.     

Can a Convolutional Neural Network Classify Knee Osteoarthritis on Plain Radiographs as Accurately as Fellowship-Trained Knee Arthroplasty Surgeons?

BackgroundOsteoarthritis (OA) is the leading cause of disability among adults in the United States. As the diagnosis is based on the accurate interpretation of knee radiographs, use of a convolutional neural network (CNN) to grade OA severity has the potential to significantly reduce variability.MethodsKnee radiographs from consecutive patients presenting to a large academic arthroplasty practice were obtained retrospectively. These images were rated by 4 fellowship-trained knee arthroplasty surgeons using the International Knee Documentation Committee (IKDC) scoring system. The intraclass correlation coefficient (ICC) for surgeons alone and surgeons with a CNN that was trained using 4755 separate images were compared.ResultsTwo hundred eighty-eight posteroanterior flexion knee radiographs (576 knees) were reviewed; 131 knees were removed due to poor quality or prior TKA. Each remaining knee was rated by 4 blinded surgeons for a total of 1780 human knee ratings. The ICC among the 4 surgeons for all possible IKDC grades was 0.703 (95% confidence interval [CI] 0.667-0.737). The ICC for the 4 surgeons and the trained CNN was 0.685 (95% CI 0.65-0.719). For IKDC D vs any other rating, the ICC of the 4 surgeons was 0.713 (95% CI 0.678-0.746), and the ICC of 4 surgeons and CNN was 0.697 (95% CI 0.663-0.73).ConclusionsA CNN can identify and classify knee OA as accurately as a fellowship-trained arthroplasty surgeon. This technology has the potential to reduce variability in the diagnosis and treatment of knee OA.     

How should a subarachnoid hemorrhage grading scale be determined? A combinatorial approach based solely on the Glasgow Coma Scale

OBJECT: The purpose of this study was to present a combinatorial approach used to develop a subarachnoid hemorrhage (SAH) grading scale based on the patient's preoperative Glasgow Coma Scale (GCS) score. METHODS: There are 4094 different combinations that can be used to compress the 13 scores of the GCS into two to 12 grades. Break points, the positions in the scale in which two adjacent scores connote a significantly different outcome, are obtained by a direct comparison of the GCS and the Glasgow Outcome Scale (GOS). Guided by the break points, the number of combinations to be considered can be limited. All possible combinations are statistically analyzed with respect to intergrade differences in outcome. Single combinations, with the maximum number of grades having maximum intergrade outcome differences for each corresponding set of adjacent grades, must be selected. The authors verified the validity of this combinatorial approach by retrospectively analyzing 1398 consecutive patients with aneurysmal SAH who underwent surgery within 7 days of the last hemorrhage episode. The patients' GCS scores were assessed just before surgery and their GOS scores were estimated 6 months post-SAH. The combinatorial approach yields only one acceptable grading scale: I (GCS Score 15); II (GCS Scores 11-14); III (GCS Scores 8-10); IV (GCS Scores 4-7); and V (GCS Score 3). CONCLUSIONS: The combinatorial approach, guided by the break points, is so simple and systematic that it can be used again in the future when revision of the grading scale becomes necessary after development of new and effective treatment modalities that improve patients' overall outcome.