Ultrasound guided deep cervical plexus block.

We describe a new technique for achieving a deep cervical plexus block using a portable vascular access ultrasound scanner (Site-Rite II, Bard Access Systems, Pittsburgh, PA).

Sympathetic autoregulation in peripheral vascular disease.

BACKGROUND: Lower limb venous pressure increases on dependency, stimulating a local sympathetic axon reflex which triggers precapillary and arteriolar vasoconstriction. The resulting decrease in arterial calf inflow, known as the venoarteriolar response (VAR), is impaired in critical leg ischaemia. The aim of the study was to evaluate the VAR in symptomatic non-critical leg ischaemia and after restoration of leg perfusion following successful revascularization. METHODS: The study included 30 normal subjects, 30 patients with stable intermittent claudication and 30 patients with severe ischaemia who had undergone successful infrainguinal revascularization. In all patients the foot skin blood flow (flux) in the horizontal (HBF) and sitting (SBF) positions was measured using laser Doppler fluxmetry. The VAR was calculated as (HBF - SBF)/HBF x 100 per cent. The pressure that elicited the reflex (pVAR) was evaluated in the horizontal position. RESULTS: The median VAR was significantly lower in patients with stable claudication than in normal subjects or patients following successful revascularization (29.1 versus 59.5 and 63.9 per cent respectively; P < 0.0001). Similar results were obtained for the pVAR (22 versus 45 and 40 mmHg respectively; P < 0.001). There was no difference, however, in either the VAR or pVAR between normal individuals and patients following a successful bypass. CONCLUSION: Patients with claudication had a significant impairment of orthostatic sympathetic autoregulation. After successful revascularization, and in spite of the extensive disease in the receiving circulation, this autoregulation returned to normal. Presented previously to the Vascular Surgical Society in London, November 1997 and published in abstract form as Br J Surg 1998; 85: 557

Duplex-guided thrombin injection for iatrogenic femoral artery pseudoaneurysm is effective even in anticoagulated patients.

BACKGROUND: The aim was to evaluate the efficacy and safety of percutaneous thrombin injection as an alternative non-operative method for treating postcatheterization femoral artery pseudoaneurysm in both anticoagulated and non-anticoagulated patients. METHODS: Thirty consecutive patients with a femoral artery pseudoaneurysm secondary to radiological catheterization confirmed by duplex imaging were included. Thrombin 200-2000 units (1000 units/mi) in a titrating dose was injected into the centre of the cavity under duplex ultrasonographic guidance. Thrombosis was assessed in real time using B mode and colour flow. No sedation or anaesthesia was required during the procedure. The distal pulses and ankle pressures were evaluated before and immediately after the injection, to exclude propagation of thrombus into the femoral artery. RESULTS: Successful rapid thrombosis of the false cavity was induced in all 30 patients. There were no immediate or mid-term procedure-related complications, or recurrences at 6 weeks. Eighteen patients were anticoagulated therapeutically at the time and following the procedure with either heparin or warfarin. CONCLUSION: Percutaneous thrombin injection is a simple, quick, painless, safe and effective technique, particularly in patients taking anticoagulants.

Endovenous management of saphenous vein reflux. Endovenous Reflux Management Study Group.

PURPOSE: This study assessed clinical outcomes of two catheter-based endovenous procedures to eliminate or greatly mitigate saphenous vein reflux. MATERIALS AND METHODS: A computer-controlled, dedicated generator and two catheter designs were used to treat 210 patients at 16 private clinic and university centers in Europe. The Closure catheter applied resistive heating over long vein lengths to cause maximum wall contraction for permanent obliteration; the Restore catheter induced a short subvalvular constriction to improve the competence of mobile but nonmeeting leaflets. RESULTS: Closure treatment caused acute obliteration in 141 (93%) of 151 limbs; Restore treatment, shrinking one or more valves, acutely reduced reflux to less than 1 second in 41 (60%) of 68 limbs. Closure treatments were associated with early recanalization (6%), paresthesias (thigh, 9%; leg, 51%; P <.001), 3 skin burns, and 3 deep-vein thrombus extensions, with 1 embolism. Restore treatments were thrombogenic (16%) despite prophylactic anticoagulation, and treated valves enlarged over 6 weeks, becoming less competent. Clinical Efficacy Assessment Project clinical class was significantly improved after both treatments, up to 1 year. At 6 months, 87% of 53 Closure patients were class 0 or 1, 75% were symptom-free, and 96% of 55 treated limbs were completely free of reflux. Fourteen of 31 Restore patients (45%) had no symptoms, but 55% were class 2 or lower and only 19% had less than 1-second reflux. CONCLUSION: Closure treatment is clinically effective, albeit with offsetting complications and early failures; these are being addressed through four procedural modifications. Restore valve shrinking, although conceptually attractive, is too problematic to be competitive with Closure treatment or saphenectomy.

Combination of a clinical risk assessment score and rapid whole blood D-dimer testing in the diagnosis of deep vein thrombosis in symptomatic patients.

PURPOSE: The clinical diagnosis of deep vein thrombosis (DVT) is unreliable in more than 50% of cases, and, in recent years, plasma D-dimer assays have been used to predict the presence of DVT with high sensitivity and negative predictive values. This study investigated the use of a rapid whole blood test that could be performed and interpreted by the bedside in addition to a clinically derived risk assessment score (RAS) to determine whether a practical and cost-effective clinical model could be developed for the diagnosis and exclusion of DVT in symptomatic patients. METHODS: Two hundred consecutive patients who were referred to the vascular laboratory with clinically suspected DVT underwent the following procedures: (1) clinical assessment and stratification into low, moderate, or high risk for DVT on the basis of an RAS related to history, symptoms, and physical examination findings; (2) rapid (5-minute) whole blood D-dimer testing with a semi-qualitative agglutination technique on a fingerprick blood sample; and (3) color flow duplex ultrasound scanning with standard criteria for the diagnosis of proximal and calf DVT. RESULTS: Forty-six patients (23%) had acute DVT on duplex ultrasound scanning. Of these cases, 28 (61%) had proximal DVT and 18 (39%) were confined to the calf. A total of 88 patients were classified as low risk, 67 were classified as moderate, and 45 were classified as high risk on the basis of the RAS method. Of the patients who were classified at low risk, 4.5% (4/88) had DVT, as compared with 17.9% (12/67) in the moderate clinical risk group and 66.7% (30/45) in the high risk group. Isolated calf DVT was found in 30% (9/30), 50% (6/12), and 75% (3/4) of the high, moderate, and low risk groups, respectively. The sensitivity (8.7%, 26.1%, 65.2%), specificity (45.5%, 64.3%, 90.3%), positive predictive value (4.5%, 17.9%, 66.7%), and overall accuracy rate (37%, 55.5%, 84.5%) of the low, moderate, and high risk groups, respectively, in the diagnosis of DVT increased significantly with increasing risk score stratification. The sensitivity, specificity, positive and negative predictive value, and overall accuracy of the rapid D-dimer test for all DVT were 91.3%, 81.9%, 60%, 96.9%, and 84%, respectively, with a 100% sensitivity and negative predictive value for proximal DVT. A combination of the RAS and D-dimer identified a low risk group with a negative D-dimer as having less than a 1% likelihood of DVT and a high risk group with positive D-dimer as having a likelihood of more than 90%. CONCLUSION: A combination of clinical assessment and rapid D-dimer testing provides an effective means of excluding proximal DVT in symptomatic patients. The application of a clinical diagnostic model on the basis of these parameters has the potential for saving a large proportion of unnecessary duplex scans with the associated time and costs.

Mobile carotid plaques: the natural history of two asymptomatic and non-operated cases.

We studied two cases of mobile internal carotid artery lesions in symptom-free patients. Both cases were diagnosed by means of routine carotid duplex ultrasound scanning, and neither patient was operated on. With medical therapy with oral anticoagulants, the two lesions spontaneously disappeared without any clinical sequel, and no evidence of infarcts was shown by means of repeated computed tomography brain scans. After uneventful 2- and 3-year follow-up periods, there was no evidence of recurrence. This is the first published data on asymptomatic mobile carotid lesions and their natural history that shows a benign course in a long-term follow-up period. We suggest that a non-surgical approach may be considered selectively in high-risk symptom-free patients who have mobile and floating internal carotid artery lesions.

Evaluation of TRISS as a means of selecting trauma deaths for clinical peer review.

This study was carried out to evaluate the predictive power of a mathematical model called TRISS in identifying avoidable trauma deaths when compared with peer review (PR). The subjects studied comprised the 24 deaths that occurred among 81 severely injured patients (Injury Severity Score greater than or equal to 16) admitted to a trauma unit over a 1 year period. Sixteen patients who had a greater than 50% probability of survival (Ps) calculated by TRISS died. Peer review concluded that five of those were potentially avoidable deaths. Eight deaths occurred in patients with a Ps less than 50%. Peer review regarded those eight as inevitable deaths. The data, when analysed, showed TRISS to have a 100% sensitivity, 42% specificity, 31% positive predictive value and a negative predictive value of 100% when compared with peer review. It is concluded that TRISS tends to over-estimate potentially avoidable death, especially in patients with severe head injury. However it is a good audit filter as it reliably excludes inevitable death.