Normalization rates of compression ultrasonography in patients with a first episode of deep vein thrombosis of the lower limbs: association with recurrence and new thrombosis.
BACKGROUND AND OBJECTIVES: Delayed thrombus regression after a first episode of deep vein thrombosis (DVT) of the inferior limbs has been implicated in the development of the post-thrombotic syndrome. Whether normalization of vein segments involved in the index DVT has prognostic significance with respect to the probability of DVT recurrence or new thrombosis is currently unknown. In this study, we prospectively monitored thrombus regression in consecutive patients with symptomatic and asymptomatic DVT. Factors affecting normalization rates and the relationship between previous normalization and DVT recurrence or new thrombosis were explored. DESIGN AND METHODS: One hundred and seventy-nine patients with a first episode of symptomatic DVT of the lower limbs (38 with cancer) and 104 patients with DVT occurring after hip replacement surgery were serially monitored by real time B-mode compression ultrasonography (C-US) over a period of 12 months (months 1, 3, 6 and 12). C-US normalization of popliteal and femoral venous segments was arbitrarily assigned to be residual thrombus occupying, at maximum compressibility, less than 40% of the vein area in the absence of compression. RESULTS: In patients with no DVT recurrence or new thrombosis, C-US normalization was observed at 12 months in 100% of 99 patients with post-operative DVT, in 59% of 134 cancer-free symptomatic DVT outpatients and in 23.3% of 30 symptomatic DVT outpatients with cancer (p = 0.0001). Independent negative effects on the probability of C-US normalization were observed for younger age (p <0.05), for the outpatient presentation of the index DVT (p 0.017), for DVT involving the entire femoro-popliteal axis (p 0.05), and for the presence of cancer (p 0.05). DVT recurrence or new thrombosis was observed in 5 patients with post-operative DVT (4.8%), in 7 cancer-free patients with symptomatic DVT (5.0%) and in 8 patients with cancer (21.1%). Only 4 of these patients had shown normalization of their index DVT prior to the event. The presence of cancer was the only significant predictor of DVT recurrence and/or new thrombosis occurring within 3 months from the index DVT (OR = 4.90, p = 0.002). The absence of previous C-US normalization was the only predictor of recurrence or new thrombosis occurring after 3 and 6 months from the index DVT (OR 5.26, p 0.027). INTERPRETATION AND CONCLUSIONS: Absence of C-US normalization after a first episode of DVT appears to be a factor favoring recurrence or new thrombosis and may be relevant to the optimal duration of oral anticoagulant treatment. (+info)
Time course of skeletal muscle repair and gene expression following acute hind limb ischemia in mice.
DNA microarrays were used to measure the time course of gene expression during skeletal muscle damage and regeneration in mice following femoral artery ligation (FAL). We found 1,289 known sequences were differentially expressed between the FAL and control groups. Gene expression peaked on day 3, and the functional cluster "inflammation" contained the greatest number of genes. Muscle function was depressed for 3 days postligation, but returned to normal by day 7. Decreased muscle function was accompanied by reduced expression of genes involved in mitochondrial energy production, muscle contraction, and calcium handling. The induction of MyoD on day 1 denoted the beginning of muscle regeneration and was followed by the reemergence of the embryonic forms of muscle contractile proteins, which peaked at day 7. Transcriptional analysis indicated that the ischemic skeletal muscle may transition through a functional adaptation stage with recovery of contractile force prior to full regeneration. Several members of the insulin-like growth factor axis were coordinately induced in a time frame consistent with their playing a role in the regenerative process. (+info)
Cardiac troponin I predicts short-term mortality in vascular surgery patients.
BACKGROUND: Cardiac troponin I (cTnI) is a highly sensitive and specific marker for myocardial injury that predicts outcomes in patients with acute coronary syndromes. Cardiovascular complications are the leading cause of morbidity and mortality in patients who have undergone vascular surgery. However, postoperative surveillance with cardiac enzymes is not routinely performed in these patients. We evaluated the association between postoperative cTnI levels and 6-month mortality and perioperative myocardial infarction (MI) after vascular surgery. METHODS AND RESULTS: Two hundred twenty-nine patients having aortic or infrainguinal vascular surgery or lower extremity amputation were included in this study. Blood samples were analyzed for cTnI immediately after surgery and the mornings of postoperative days 1, 2, and 3. An elevated cTnI was defined as serum concentrations >1.5 ng/mL in any of the 4 samples. Twenty-eight patients (12%) had postoperative cTnI >1.5 ng/mL, which was associated with a 6-fold increased risk of 6-month mortality (adjusted OR, 5.9; 95% CI, 1.6 to 22.4) and a 27-fold increased risk of MI (OR, 27.1; 95% CI, 5.2 to 142.7). Furthermore, we observed a dose-response relation between cTnI concentration and mortality. Patients with cTnI >3.0 ng/mL had a significantly greater risk of death compared with patients with levels < or =0.35 ng/mL (OR, 4.9; 95% CI, 1.3 to 19.0). CONCLUSIONS: Routine postoperative surveillance for cTnI is useful for identifying patients who have undergone vascular surgery who have an increased risk for short-term mortality and perioperative MI. Further research is needed to determine whether intervention in these patients can improve outcome. (+info)
Limb salvage and amputation in survivors of pediatric lower-extremity bone tumors: what are the long-term implications?
The past four decades have seen tremendous progress in the treatment of pediatric and adolescent cancers. As a consequence, there are increasing numbers of adult childhood cancer survivors. This has prompted investigation into the long-term consequences of cancer treatments. One group that merits special study is the survivors of lower-extremity bone tumors. Their function and quality of life may depend in part on both the surgery and the age at which it was performed. Comparisons between studies are difficult because small numbers of patients and the use of varying research designs and methods have limited research in this area. The purpose of this article is to review the major surgical approaches to lower-limb bone tumors and their impact on pediatric patients. The results show that survival is equivalent between amputation and limb salvage. Complications occur more frequently in limb salvage. The long-term outcomes of those undergoing amputation and limb salvage have not been found to be substantially different in regard to quality of life. In conclusion, prospective long-term follow-up of pediatric patients with lower-limb tumors is needed to (1) determine in a uniform manner the long-term complications, quality of life, and functionality of this population and describe differences within this patient population based on age at diagnosis and surgical procedure, (2) identify areas of concern that are amenable to intervention, and (3) provide clinicians and future patients a better understanding of the surgical options. (+info)
Increased platelet aggregation and activation in peripheral arterial disease.
OBJECTIVES: patients with peripheral arterial disease (PAD) have a threefold increase in cardiovascular mortality. Standard antiplatelet treatment may not confer uniform benefit in different patient groups. This study aimed to compare platelet function in patients with lower limb PAD, carotid disease and abdominal aortic aneurysm (AAA) with age- and sex-matched healthy controls. METHODS: patients with lower limb PAD (n = 20), carotid disease (n = 40), AAA (n = 13) and age/sex matched healthy controls (n= 20) were studied. Whole blood methods to detect spontaneous platelet aggregation (SPA), and adenosine diphosphate (ADP) and collagen-induced aggregation were used. The detection of platelet P-selectin and the PAC-1 antigen by flow cytometry were also used as markers of platelet activation and aggregation. RESULTS: patients with lower limb PAD or AAA had higher baseline SPA compared to normal controls (p < 0.01). There was significantly higher collagen-induced aggregation in IC patients compared to normal controls (p < 0.01). However, there was no difference in ADP-induced aggregation between lower limb PAD and control patients. There was no difference in PAC-1 binding between control patients and the patients with lower limb PAD, carotid disease or AAA. Patients with carotid disease had a higher expression of P-selectin compared to normal controls (p < 0.05). CONCLUSIONS: this study provides further evidence that platelet hyperactivity is present in patients with PAD despite the use of antiplatelet therapy. Further antiplatelet strategies may be indicated to protect these patients. (+info)
Ultrasound contrast-agent improves imaging of lower limb occlusive disease.
OBJECTIVES: to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA). DESIGN: prospective and consecutive study. MATERIAL: of 60 consecutive PAD patients, 15 were found to have an inconclusive duplex-ultrasound scan of the trifurcation and were included in the study. All 15 patients (53% male) were scheduled for DSA, all being candidates for vascular surgery due to claudication (n = 3, 20%), rest pain (n = 5, 33%) and tissue loss (n = 7, 47%). METHODS: on the day before DSA, a duplex-ultrasound scan of the trifurcation was performed. If the duplex-ultrasound scan was found inconclusive, it was repeated during continuous ultrasound contrast-agent infusion. DSA was performed unaware of the duplex-ultrasound results and served as the gold standard. RESULTS: after contrast-agent administration, the number of inconclusively diagnosed segments was significantly reduced by 26 (70%), from 37 to 11(p < 0.001). In 19 segments (73%) contrast-agent infusion changed the diagnosis in accordance with the DSA (p < 0.05). Values of sensitivity and positive predictive value were improved from 0.20 (0.04-0.62) to 0.47 (0.26-0.69) and 0.50 (0.10-0.91) to 0.80 (0.49-0.93), respectively. Specificity and negative predictive value were unchanged. Agreement between duplex-ultrasound and DSA were improved from poor (kappa = 0.18 (95% CI: 0-0.82)) to moderate (kappa = 0.45 (0.17-0.74)) (p = 0.44). CONCLUSION: ultrasound contrast-agents improve the diagnostic ability of duplex-ultrasound when scanning difficult arterial segments in patients suffering from PAD. (+info)
BACKGROUND: microtibial embolectomy is an important technique in cases of limb threatening acute arterial occlusion affecting native crural and pedal vessels. It is particularly useful when thrombolysis is contraindicated or ineffective as in "trash foot". METHODS: in order to evaluate the efficacy of this technique, a retrospective case note review was carried out for patients undergoing microtibial embolectomy from 1990 to 1999. Data collected included the causes and degree of ischaemia, additional procedures required, vessel patency, limb salvage and complications encountered. RESULTS: twenty-two limbs underwent exploration of the crural/pedal vessels with ankle level arteriotomies under local anaesthetic in 12 cases, general anaesthetic in nine and epidural in one. The causes of ischaemia were cardiac emboli (8), "trash foot" (7), emboli from aortic and popliteal aneurysms (3) and thrombotic occlusion of crural vessels (4). The vessel patency rate was 69% and limb salvage rate 62% (13/21) up to 5-years follow-up. Six of the seven cases with "trash foot" were salvaged while one required an amputation at 3-months post-operatively. The 30-day mortality was 22% (5/22). CONCLUSIONS: microtibial embolectomy is effective in acute occlusion of the crural/pedal arteries including cases of "trash foot", offering limb salvage to a worthwhile proportion of cases. (+info)
Leg muscle strength is reduced in Parkinson's disease and relates to the ability to rise from a chair.
Individuals with Parkinson's disease (PD) have difficulties rising from a chair; however, factors contributing to this inability have never been investigated. We compared lower extremity strength between individuals with PD and healthy controls and quantified the relationships between strength and the ability to rise from a chair. Ten men with mild PD and 10 sex- and age-matched controls performed maximal concentric, isokinetic knee and hip extensor torque on an isokinetic dynamometer to quantify muscle strength. Subjects also rose from a chair at their comfortable pace without the use of their arms and the duration of this task provided a measure of sit-to-stand (STS) ability. Subjects with PD were tested in an on- and off-medication state on different days. Mean hip and knee extensor torques were lower in subjects with PD, with greater deficits found at the hip. Greater hip strength was related to better STS ability in subjects with PD while greater knee strength was related to better STS ability in controls. These results show that individuals with mild PD generate smaller extremity forces compared to controls. Reduced strength, particularly at the hip, may be one factor that contributes to the difficulty of persons with PD to rise from a chair. (+info)