In vivo carotid strain imaging using principal strains in longitudinal view.

Carotid plaque rupture can result in stroke or transient ischemic attack that can be devastating for patients. Ultrasound strain imaging provides a noninvasive method to identify unstable plaque likely to rupture. Axial, lateral and shear strains in carotid plaque have been shown to be linked to carotid plaque instability. Recently, there has been interest in using principal strains, which do not depend on angle of insonification of the carotid artery for quantifying instability in plaque along the longitudinal view. In this work relationships between angle dependent axial, lateral and shear strain along with axis independent principal strains are compared. Three strain indices were defined, 1) Average Mean Strain (AMS), 2) Maximum Mean Strain (MMS) and 3) Mean Standard Deviation (MSD) to identify relationships between these five strain image types in a group of 76 in vivo patients. The maximum principal strain demonstrated the highest strain values when compared to axial strain for all patients with a linear regression slope of 1.6 and a y intercept of 2.4 percent strain for AMS. The maximum shear strain when compared to shear strain had a slope of 1.15 and a y intercept of 0.21 percent for AMS. Next, the effect of insonification angle, which is the angle subtended by the artery at the location of plaque was studied. Patients were divided into three sub groups, i.e. less than 5 degrees (n = 31), between 5 and 10 degrees (n = 24) and above 10 degrees (n = 21). The angle of insonification did not make a significant difference between the three angle groups when comparing the relationship between the angle dependent and independent strain values.

A Cross-Sectional Investigation of Cognition and Ultrasound-Based Vascular Strain Indices.

OBJECTIVE: We examine the relationship between variability in the plaque strain distribution estimated using ultrasound with multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. METHOD: Asymptomatic (n = 42) and symptomatic (n = 34) patients with significant (>60%) carotid artery stenosis were studied for plaque instability using ultrasound strain imaging and multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. Correlation and ROC analyses were performed between ultrasound strain indices and cognitive function. Strain indices and cognition scores were also compared between symptomatic and asymptomatic patients to determine whether there are significant group differences. RESULTS: Association of high-strain distributions with dysexecutive function was observed in both asymptomatic and symptomatic patients. For memory, visuospatial, and language functions, the correlations between strain and cognition were weaker for the asymptomatic compared to symptomatic group. CONCLUSIONS: Both asymptomatic and symptomatic patients demonstrate a relationship between vessel strain indices and executive function indicating that silent strokes and micro-emboli could initially contribute to a decline in executive function, whereas strokes and transient ischemic attacks may cause the further decline in other cognitive functions.

Quantification of carotid artery plaque stability with multiple region of interest based ultrasound strain indices and relationship with cognition.

Vulnerability and instability in carotid artery plaque has been assessed based on strain variations using noninvasive ultrasound imaging. We previously demonstrated that carotid plaques with higher strain indices in a region of interest (ROI) correlated to patients with lower cognition, probably due to cerebrovascular emboli arising from these unstable plaques. This work attempts to characterize the strain distribution throughout the entire plaque region instead of being restricted to a single localized ROI. Multiple ROIs are selected within the entire plaque region, based on thresholds determined by the maximum and average strains in the entire plaque, enabling generation of additional relevant strain indices. Ultrasound strain imaging of carotid plaques, was performed on 60 human patients using an 18L6 transducer coupled to a Siemens Acuson S2000 system to acquire radiofrequency data over several cardiac cycles. Patients also underwent a battery of neuropsychological tests under a protocol based on National Institute of Neurological Disorders and Stroke and Canadian Stroke Network guidelines. Correlation of strain indices with composite cognitive index of executive function revealed a negative association relating high strain to poor cognition. Patients grouped into high and low cognition groups were then classified using these additional strain indices. One of our newer indices, namely the average L - 1 norm with plaque (AL1NWP) presented with significantly improved correlation with executive function when compared to our previously reported maximum accumulated strain indices. An optimal combination of three of the new indices generated classifiers of patient cognition with an area under the curve (AUC) of 0.880, 0.921 and 0.905 for all (n = 60), symptomatic (n = 33) and asymptomatic patients (n = 27) whereas classifiers using maximum accumulated strain indices alone provided AUC values of 0.817, 0.815 and 0.813 respectively.

Safety and tolerability of collagenase Clostridium histolyticum and fasciectomy for Dupuytren's contracture.

Safety was evaluated for collagenase Clostridium histolyticum (CCH) based on 11 clinical trials (N = 1082) and compared with fasciectomy data in a structured literature review of 48 European studies (N = 7727) for treatment of Dupuytren's contracture. Incidence of adverse events was numerically lower with CCH vs. equivalent complications from fasciectomy (median [range] incidence), including nerve injury (0% vs. 3.8% [0%-50+%]), neurapraxia (4.4% vs. 9.4% [0%-51.3%]), complex regional pain syndrome (0.1% vs. 4.5% [1.3%-18.5%]) and arterial injury (0% vs. 5.5% [0.8%-16.5%]). Tendon injury (0.3% vs. 0.1% [0%-0.2%]), skin injury (16.2% vs. 2.8% [0%-25.9%]) and haematoma (77.7% vs. 2.0% [0%-25%]) occurred at a numerically higher incidence with CCH than surgery. Adverse events in CCH trials not reported after fasciectomy included peripheral oedema; extremity pain; injection site pain, haemorrhage and swelling; tenderness; pruritus and lymphadenopathy. CCH-related adverse events were reported as predominantly injection-related and transient. These results may support clinical decision-making for treatment of Dupuytren's contracture.

Dupuytren contracture recurrence project: reaching consensus on a definition of recurrence.

The aim of this study was to determine a definition of recurrence of Dupuytren disease that could be utilized for the comparison of the results independently from the treatment used. 24 hand surgeons from 17 countries met in an international consensus conference. The participants used the Delphi method to evaluate a series of statements: (1) the need for defining recurrence, (2) the concept of recurrence applied to the Tubiana staging system, (3) the concept of recurrence applied to each single treated joint, and (4) the concept of recurrence applied to the finger ray. For each item, the possible answer was given on a scale of 1-5: 1=maximum disagreement; 2=disagreement; 3=agreement; 4=strong agreement; 5=absolute agreement. There was consensus on disagreement if 1 and 2 comprised at least 66% of the recorded answers and consensus on agreement if 3, 4 and 5 comprised at least 66% of the recorded answers. If a threshold of 66% was not reached, the related statement was considered "not defined". A need for a definition of recurrence was established. The presence of nodules or cords without finger contracture was not considered an indication of recurrence. The Tubiana staging system was considered inappropriate for reporting recurrence. Recurrence was best determined by the measurement of a specific joint, rather than a total ray. Time 0 occurred between 6 weeks and 3 months. Recurrence was defined as a PED of more than 20° for at least one of treated joint, in the presence of a palpable cord, compared to the result obtained at time 0. This study determined the need for a standard definition of recurrence and reached consensus on that definition, which we should become the standard for the reporting of recurrence. If utilized in subsequent publications, this will allow surgeons to compare different techniques and make is easier to help patients make an informed choice.

Dupuytren's contracture and sarcoma.

In order to study possible connections between Dupuytren's contracture and sarcoma we analysed the records of 18 patients who developed sarcoma 5 years or more after surgery for Dupuytren's contracture. We found an increased frequency of fibrosarcoma and malignant fibrous histiocytoma, but these patients did not differ from the other patients in the study group. Our analysis suggests that neither smoking, diabetes nor cancer syndromes can explain why patients with Dupuytren's contracture have a higher incidence of sarcoma.

Cancer incidence in patients treated surgically for Dupuytren's contracture.

Our aim was to study risk factors for Dupuytren's contracture (DC) by assessing cancer morbidity in a group of Swedish patients treated surgically for Dupuytren's contracture. The risk of cancer was determined in 15,212 patients operated on for Dupuytren's contracture, identified in the nationwide Swedish Inpatient Register during the period 1965 to 1994 by means of record linkage to the Swedish Cancer Register. Standardized incidence ratios (SIRs) were computed using age-, sex- and period-specific incidence rates derived from the entire Swedish population. The overall relative risk of cancer was increased by 24%. There were significantly increased risks for malignancies related to smoking such as buccal, oesophageal, gastric, lung and pancreatic cancers. Significantly increased risks were present for both prostate and rectal cancer in men and an increase risk for breast cancer in women was noted 1 year or more after surgery for Dupuytren's contracture. The present study confirms smoking and alcohol abuse as probable risk factors for DC. There are characteristics in patients with DC that alter the risks for other malignancies compared with the general population.

The sex ratio and rate of reoperation for Dupuytren's contracture in men and women.

We identified all patients treated by local fasciectomy at the Department of Hand Surgery, Uppsala University Hospital between 1965 and 1996. A total of 2375 operations were performed on 1600 patients. We found a male:female ratio of 5.9:1. Women had a higher mean age at first operation (62.4 years) than men (59.8 years). One-third of the men required repeated surgery and one-quarter of the women. Early age at first operation was associated with recurrent disease.

Patency of the cochlear aqueduct.

The patency of the cochlear aqueduct is discussed against the background of radioanatomic studies of 225 plastic casts of temporal bone specimens and additional experimental and clinical observations. The occasional presence of a wide venous channel running parallel with the cochlear aqueduct, as well as the existence of up to three accompanying venous channels can simulate a pathologically wide cochlear aqueduct radiographically. This could constitute a diagnostic pitfall in the absence of other clinical and radiographic signs of malformation.