[Necrotising soft tissue infection of orbital area and hand: an unusual combination]. / Necrotiserende wekedeleninfectie van hand en oog.

BACKGROUND: Necrotising soft tissue infection (NSTI) is an infection of the subcutaneous tissues and often follows a fulminant course if not recognised in time. CASE DESCRIPTION: A 78-year-old man was brought to our emergency department in septic shock. Physical examination revealed an erythematous and painful swelling of the right eyelids and to a lesser extent of the right hand. The infection progressed at both sites, and suspicion of NSTI arose. An emergency surgical debridement was performed. Pathological examination of the excised tissue confirmed the presence of a necrotising infection of the fascia consistent with NSTI at both sites. CONCLUSION: This case history describes a, not previously described, 'double' presentation of NSTI. In a patient with misunderstood sepsis in combination with a soft tissue infection, it is important to consult a surgeon immediately. This case report emphasises the need for a multidisciplinary approach when treating patients with these clinical pictures. CONFLICT OF INTEREST AND FINANCIAL SUPPORT: NONE DECLARED.

Inguinal hernia surgery in The Netherlands: are patients treated according to the guidelines?

PURPOSE: In 2003, a dedicated Dutch committee developed evidence-based guidelines for the treatment of inguinal hernia (IH) in children and adults. The aim of this study was to describe trends in hernia care before and after the publication of the guidelines on IH surgery in The Netherlands. METHODS: Originally, a retrospective baseline analysis of IH surgery in 90 Dutch hospitals was performed among patients treated for IH in 2001. The results of this baseline analysis were compared with a recently performed second analysis of patients treated for IH in 2005. RESULTS: In children <4 years of age, the study showed a significant decrease of contralateral explorations. In adults, the study showed that significantly more patients were treated with a mesh-based repair in 2005 (95.9 vs. 78.8%, P < 0.01). Moreover, there was an increase of patients with bilateral hernia treated with an endoscopic technique (41.5 vs. 22.3%, P < 0.01) and more patients were treated in day surgery (53.5 vs. 38.6%, P < 0.01). Lastly, a decline in operations performed for recurrent IH in adults was observed (10.9 vs. 13.3%, P < 0.01). CONCLUSION: This study showed that most patients with IH in The Netherlands were treated according to the main recommendations of the Dutch evidence-based guidelines.

[Neuralgic pain, a significant complication after a Lichtenstein procedure for inguinal hernia repair]. / Neuralgische pijn, een niet te onderschatten complicatie van een liesbreukoperatie volgens de methode van Lichtenstein.

Two male patients, aged 37 and 56, suffered from neuralgic pain after a Lichtenstein procedure for inguinal hernia repair using prosthetic reinforcement. Since mesh-based repair techniques have decreased the recurrence rate, postoperative inguinal pain has become a major complication of these operations. Three months after surgery, 20% of the patients experience some pain. In 12% of the patients this pain limits daily activities and 1-3% of the patients are invalidated by neuralgic pain. Preventing damage to sensory nerves during the operation is one way of preventing neuralgic pain. Damaged sensory nerves should be excised. Neuralgic pain after the operation may be alleviated by tricyclic antidepressants, opioids or antiepileptic drugs. In selected patients with neuralgic pain neurectomy is indicated. In one of the patients presented the neuralgic pain disappeared after neurectomy of the ilioinguinal nerve. Triple neurectomy in the other patient, however, was unsuccessful.

Inguinal hernia surgery in The Netherlands: a baseline study before the introduction of the Dutch Guidelines.

BACKGROUND: In 2003 the Dutch Guidelines for treatment of inguinal hernia (IH) were published. For treatment of IH in adults, the evidence-based guidelines recommend the use of a mesh repair technique. In order to be able to evaluate the effects of these guidelines, a baseline analysis of inguinal hernia surgery before the introduction of these guidelines had to be performed. The second analysis will be performed two years (January-March 2005) after the publication of the Guidelines. OBJECTIVE: To make an inventory of IH surgery in the Netherlands, before the introduction of guidelines for IH treatment, to serve as a baseline for future evaluation of the impact of the implementation of these guidelines. METHODS: A retrospective descriptive study was performed in 2003 using patient and operation charts including IH repairs performed in The Netherlands over a three-month period (January-March 2001). RESULTS: 97/133 (73%) hospitals cooperated with the study, generating data from a total of 4386 IH in 3979 patients (3284 adults, 695 children). Mesh techniques were used in 2839 (78%) adult inguinal hernias while 800 (22%) patients were treated with non-mesh techniques. 484 (14.7%) adult patients were operated on during the study period for a recurrent hernia from previous years. Early recurrence (<1 year) occurred in 2.2% of all patients. Wound infection was documented in 0.8% of all IH. The mortality rate was 0.1%. 1257 of the 3284 (38.3%) adults, and 566 of the 695 children (81.4%), were operated on in ambulatory care. CONCLUSIONS: In the episode prior to implementation of the Dutch evidence-based Guidelines for treatment of inguinal hernia, 2839 (78%) adult patients were treated with mesh repair and 484 (13.3%) patients were treated for a recurrent hernia.

Hernia surgery changes in the Amsterdam region 1994-2001: decrease in operations for recurrent hernia.

Inguinal hernia (IH) surgery has changed substantially in the past decade. Conventional (nonmesh) techniques have largely given way to prostheses. This study's aim was to analyse whether changes in technique used for IH repair influenced the operation rate for recurrence. A retrospective study was performed on all adult males who had undergone IH surgery in the Amsterdam region during the calendar years of 1994, 1996, 1999, and 2001. Data were obtained for 3,649 subjects and included patient demographics, hernia type, and surgical technique. We observed a decrease in the use of conventional techniques and a significant increase (P<0.05) in the use of prosthetic materials. The number of operations performed for recurrent hernia decreased from 19.5% (216/1,108) in 1994, to 16.8% 197/1,170) in 1996, to 14.0% (152/1,088) in 1999, and to 14.1% (40/283) in 2001. When comparing 1999 and 2001 with 1994, there was a significant decrease in operations performed for recurrent hernia (P=0.005). There was also a significant increase in supervision of the surgical resident by a surgeon.

Overcoming selective ensemble averaging: unsupervised identification of event-related brain potentials.

We present a novel approach to the problem of event-related potential (ERP) identification, based on a competitive artificial neural network (ANN) structure. Our method uses ensembled electroencephalogram (EEG) data just as used in conventional averaging, however without the need for a priori data subgrouping into distinct categories (e.g., stimulus- or event-related), and thus avoids conventional assumptions on response invariability. The competitive ANN, often described as a winner takes all neural structure, is based on dynamic competition among the net neurons where learning takes place only with the winning neuron. Using a simple single-layered structure, the proposed scheme results in convergence of the actual neural weights to the embedded ERP patterns. The method is applied to real event-related potential data recorded during a common odd-ball type paradigm. For the first time, within-session variable signal patterns are automatically identified, dismissing the strong and limiting requirement of a priori stimulus-related selective grouping of the recorded data. The results present new possibilities in ERP research.

Modeling and estimation of single evoked brain potential components.

In this paper, we present a novel approach to solving the single-trial evoked-potential estimation problem. Recognizing that different components of an evoked potential complex may originate from different functional brain sites and can be distinguished according to their respective latencies and amplitudes, we propose an estimation approach based on identification of evoked potential components on a single-trial basis. The estimation process is performed in two stages: first, an average evoked potential is calculated and decomposed into a set of components, with each component serving as a subtemplate for the next stage; then, the single measurement is parametrically modeled by a superposition of an emulated ongoing electroencephalographic activity and a linear combination of latency and amplitude-corrected component templates. Once optimized, the model provides the two assumed signal contributions, namely the ongoing brain activity and the single evoked brain response. The estimator's performance is analyzed analytically and via simulation, verifying its capability to extract single components at low signal-to-noise ratios typical of evoked potential data. Finally, two applications are presented, demonstrating the improved analysis capabilities gained by using the proposed approach. The first application deals with movement related brain potentials, where a change of the single evoked response due to external loading is detected. The second application involves cognitive event-related brain potentials, where a dynamic change of two overlapping components throughout the experimental session is detected and tracked.

A robust parametric estimator for single-trial movement related brain potentials.

Current estimators for single-trial evoked potentials (EP's) require a signal-to-noise ratio (SNR) of 0 dB or better to obtain high quality estimations, yet many types of EP's suffer from substantially lower SNR's. This paper presents a robust-evoked-potential-estimator (REPE) facilitating high quality estimations of single movement related EP's with a relatively low SNR. The estimator is based on a standard ARX model, enhanced to support estimation under poor SNR conditions. The REPE was tested successfully on a computer simulated data set giving reliable single-trial estimations for the low SNR range of around -20 dB. THe REPE was also applied to experimental data, producing clear single-trial estimations of movement related brain signals recorded in a classic scenario of self-paced finger tapping experiment.

Segmented matched filtering of single event related evoked potentials.

A fast segmentation-based Matched Filtering (MF) technique of single trial Evoked Potentials (EP's) is presented. MF improves the Signal-to-Noise Ratio of single EP's, reducing the number of repetitions necessary to obtain high quality signals by an order of magnitude. A computer simulation and analysis of experimental data of Movement Related Potentials and cognitive Event Related Potentials demonstrate the superior capabilities of MF compared to traditional Ensemble Averaging.