Accuracy and Reliability of Peripheral Artery Calcium Scoring Systems Using an Intravascular Ultrasound Reference Standard.

BACKGROUND: Peripheral artery calcium scoring systems are commonly used in clinical trials to categorize calcium severity but there are little data on their accuracy and reliability. The purpose of this study was to investigate the accuracy and reliability of these systems. METHODS: Angiographic, computed tomography angiography, and intravascular ultrasound (IVUS) imaging were obtained from 47 consecutive cases sourced from a prospectively collected database of patients undergoing femoropopliteal artery endovascular intervention. Two independent blinded readers graded calcium severity using the Peripheral Arterial Calcium Scoring System, Peripheral Academic Research Consortium, and Fanelli calcium scoring systems. IVUS maximum arc of calcium and calcium length were compared between severity grades for each scoring system. The diagnostic accuracy of each scoring system for identifying severe calcium was calculated using the reference standard of an IVUS maximum calcium arc ≥ 180°. Agreement testing was performed between scoring systems and between and within observers for each system. RESULTS: IVUS identified calcium in 85% (42/47) of cases, compared to 68% (32/47) of cases with angiography. There were no differences in IVUS calcium parameters between grades of calcium for any of the scoring systems. Severe calcium was detected by IVUS in 30 cases, in 23 cases by Peripheral Arterial Calcium Scoring System (sensitivity: 73%, specificity: 33%, positive predictive value [PPV]: 83%, negative predictive value [NPV]: 22%), in 12 cases by Peripheral Academic Research Consortium (sensitivity: 42%, specificity: 83%, PPV: 92%, NPV: 25%), and in 10 cases by Fanelli (sensitivity: 39%, specificity: 100%, PPV: 100%, NPV: 27%). Agreement between scoring systems was weak to moderate (range: k = 0.55-0.74). Interobserver agreement was weak (k = 0.41-0.54) and intraobserver agreement was highly variable ranging from k = 0.41 to k = 0.92. CONCLUSIONS: The poor diagnostic accuracy and weak-to-moderate reliability of calcium scoring systems raise doubts about the use of current calcium scoring systems for use in clinical trials.

Comparison of Angiographic Dissection Classification Systems in the Femoropopliteal Arteries Using IVUS Validation and Reliability Testing.

PURPOSE: Objective assessment of dissection severity is difficult. Recognition of this has led to the creation of classification systems. This study investigated the performance of the National Heart Lung and Blood Institute (NHLBI) and Kobayashi systems at differentiating severity of femoropopliteal dissection using intravascular ultrasound (IVUS) as the reference standard. Comparison between the 2 systems and the inter- and intra-observer reliability were also investigated. MATERIALS AND METHODS: Angiographic and IVUS imaging was assessed in 51 cases sourced from a RCT investigating the use of IVUS in femoropopliteal disease. A total of 2 readers independently scored the angiography images according to NHLBI and Kobayashi dissection classification systems and a consensus score was obtained for each system in each case. The NHLBI classification was condensed into 3 grades of dissection to allow comparison between systems. Dissection length, dissection arc, minimum lumen area, and lumen area stenosis were obtained from the IVUS imaging. IVUS parameters were compared between grades of severity for both systems. Agreement in grading between the systems was assessed and IVUS parameters for each level of dissection severity were compared between systems. Inter and intra-observer agreement tested for each system. RESULTS: Dissection was present on IVUS in 92.2% (47/51) of cases and angiography identified 78.7% (37/47) of these. No difference was present in any IVUS parameters between mild and severe dissections with either classification system. No difference in IVUS findings was present for the same grades of dissection between systems. The 2 systems agreed on severity grade in 47 of 51 cases. The inter-observer agreement was for NHLBI was k=0.549 and k=0.627 for Kobayashi. Intra-observer agreement for NHLBI was k=0.633 and k=0.633 and for Kobayashi was k=0.657 and k=0.297. CONCLUSION: The lack of difference in IVUS parameters between mild and severe dissection for the NHLBI and Kobayashi systems raises doubts about their ability to effectively differentiate dissection severity. Weak to moderate reliability suggests that variability in interpreting dissection may be higher than acceptable. IVUS imaging is more sensitive for detecting dissection than angiography and research is required to establish the value of adding IVUS to dissection classification systems.

Endovascular treatment of diabetic foot ischemic ulcer - Technical review.

This article is a technical review of the common techniques used in the treatment of lower-limb occlusive arterial disease associated with diabetes. The techniques described here reflect the author's own practice and are methods that the author finds helpful in avoiding complications and in making the technical aspects of the procedures easier.

A systematic review to evaluate the effectiveness of carnitine supplementation in improving walking performance among individuals with intermittent claudication.

OBJECTIVE: To evaluate the evidence for the use of carnitine supplementation in improving walking performance among individuals with intermittent claudication. DESIGN: Systematic review. METHODS: An electronic search of the literature was performed using MEDLINE (PubMed), Scopus, Cochrane Central Register of Controlled Trials and The Cochrane Library from inception through to November 2012. Search terms included peripheral arterial disease, intermittent claudication and carnitine. Reference lists of review articles and primary studies were also examined. Full reports of published experimental studies including randomized controlled trials and pre-test/post-test trials were selected for inclusion. A quality assessment was undertaken according to the Jadad scale. RESULTS: A total of 40 articles were retrieved, of which 23 did not meet the inclusion criteria. The 17 included articles reported on a total of 18 experimental studies of carnitine supplementation (5 pre-test/post-test; 8 parallel RCT; 5 cross-over RCT) for improving walking performance in adults with intermittent claudication. For pre-test/post-test studies, 300-2000 mg propionyl-L-carnitine (PLC) was administered orally or intravenously for a maximum of 90 days (7-42 participants) with statistically significant improvements of between 74 m and 157 m in pain free walking distance and between 71 m and 135 m in maximal walking distance across 3 out of 5 studies. Similarly, PLC (600 mg-3000 mg) was administered orally in 7 out of 8 parallel RCTs (22-485 participants), the longest duration being 12 months. All but one of the smallest trials demonstrated statistically significant improvements in walking performance between 31 and 54 m greater than placebo for pain free walking distance and between 9 and 86 m greater than placebo for maximal walking distance. A double-blind parallel RCT of cilostazol plus 2000 mg oral L-carnitine or placebo for 180 days (145 participants) did not demonstrate any significant improvement in walking performance. Of 5 cross-over RCTs (8-20 participants), 4 demonstrated significant improvements in walking performance following administration of 300-6000 mg L-carnitine or PLC. Compared to placebo, pain free walking distance and maximal walking distance improved by 23-132 m and 104 m respectively following carnitine intervention. CONCLUSIONS: Most trials demonstrated a small or modest improvement in walking performance with administration of PLC or L-carnitine. These findings were largely independent of level or quality of evidence, while there was some evidence that intravenous administration was more effective than oral administration and those with severe claudication may achieve greater benefits than those with moderate claudication. Routine carnitine supplementation in the form of PLC may therefore be a useful adjunct therapy for management of intermittent claudication. Further research is warranted to determine the optimal form, duration, dose and safety of carnitine supplementation across the spectrum of peripheral arterial disease severity and its effect with concurrent supervised exercise programs and best medical therapy. These studies should be supplemented with cost effectiveness studies to ensure that the return on the investment is acceptable.

Complex regional pain syndrome: a review.

Complex regional pain syndrome (CRPS), formerly known as "reflex sympathetic dystrophy," is a chronic neurological disorder characterized by disabling pain, swelling, vasomotor instability, sudomotor abnormality, and impairment of motor function. The disorder usually develops after minor trauma or surgery. No specific diagnostic test is available and, hence, diagnosis is based mainly on history, clinical examination, and supportive laboratory findings. This review gives a synopsis of CRPS and discusses the principles of management based on the limited available literature in the area. A literature search was conducted using electronic bibliographic databases (Medline, Embase, Pubmed, CENTRAL) from 1970 to 2006. Keywords complex regional pain syndrome, reflex sympathetic dystrophy, neuropathic pain, and causalgia were used for the search. Relevant articles from the reference lists in retrieved articles were also studied. There were 3,771 articles published in the area. Seventy-six randomized controlled trials were identified. Most studies were on the role of sympathetic blockade in the treatment of CRPS (n = 13). The role of sympathectomy is unclear, with some studies showing transient benefit and others showing no beneficial effects, with most studies containing only a small number of patients. Nine studies were on bisphosphonates or calcitonin. Studies involving bisphosphonates showed benefit, but studies involving calcitonin showed no definite benefit. Four studies were on cognitive behavioral therapy, physiotherapy, or occupational therapy, all of which demonstrated a potential beneficial effect. Three studies on spinal cord stimulation and two studies each on acupuncture, vitamin C, and steroid all showed a potential beneficial effect in pain reduction. The remaining studies were on miscellanous therapy or combination therapy, making it difficult to draw any conclusions on the effect of treatment. There is very little good evidence in the literature to guide treatment of CRPS. Early recognition and a multidisciplinary approach to management seems important in obtaining a good outcome. Treatments aimed at pain reduction and rehabilitation of limb function form the mainstay of therapy. Comorbidities, such as depression and anxiety, should be treated concurrently.

Dual ipsilateral renal transplantation from a non-heart-beating donor.

A case is described where both kidneys from non-heart-beating (expanded criteria) donors were dual transplanted ipsilaterally. Although both kidneys passed viability tests on the Newcastle machine preservation system and biomarkers' evaluation, there were logistical issues where the cold ischaemic time was too protracted necessitating the transplantation of both kidneys into one recipient. The recipient had satisfactory outcome with the Cockcroft-Gault creatinine clearance of 72.47 (36.29 ml/min individual kidney glomerular filtration rate) suggesting beneficial use of sub-optimal organs to improve outcome.

Transplantation from non heart beating donors in Newcastle upon Tyne.

Donor shortage has led transplant surgeons to reevaluate the concept of non heart beating donation. Organs from such donors are exposed to anoxia prior to harvesting and a portion of them will consequently present with delayed graft function. There is a need for dependable viability testing of organs from less than ideal NHBD donors and machine perfusion of kidneys provides such a tool. Our experience with own design machine perfusion device, studied parameters, perfusion solutions and outcomes is presented. Emphasis is placed on the incomparability of results obtained from different perfusion systems and the need to establish local criteria of kidney viability.