Spectral and profile analysis of Doppler recording following below-knee arterial distal bypasses.

BACKGROUND: Arterial below knee distal bypasses are associated with a high risk of thrombosis as compared to proximal bypasses. We assumed that before the bypass occludes, in the early postsurgical period, measurable velocity changes, and/or the presence of high intensity transient signals (HITS) would occur. SETTINGS: institutional reference center, hospitalized patients. SUBJECTS: satisfactory Doppler recording was obtained in 51 among 61 consecutive patients (32 males, 19 females, height: 165+/-7 cm, weight: 68+/-12 kg) suffering lower extremity arterial disease, that underwent saphenous (n=33), prosthetic (n=4) or sequential (n=14) below knee bypasses. We performed a spectral and profile analysis of a single postsurgical 2 hour Doppler recording at the ankle level and analyzed Doppler derived indices and clinical risk factors in the evaluation of the risk of bypass occlusion within 7 days following surgery. RESULTS: Primary patency at day 7 was observed in 41 of the 51 operated patients. The presence of HITS was found in approximately 30% of the patients and provided no information on the risk of thrombosis. No clinical variable was significantly associated with an increased risk of thrombosis. Whatever the duration of recording, the presence of a diastolic forward flow and wide systolic velocity changes were poor indicators of bypass thrombosis risk. On 512 beat recordings, a mean systolic velocity below 1630 Hz and a standard deviation of the resistance index >0.095 were associated with a 6.74 [1.6-28.4] (p<0.01) and 14.5 [3.6-58.9] (p<0.001) times increases in the risk of bypass occlusion respectively, compared with subjects that do not fulfill each criteria. CONCLUSIONS: Periods of transient asymptomatic no-flow-reflow events may be observed before the bypass irreversibly occludes. Prolonged Doppler recording should be preferred to short term analyses, to allow for the detection of these transient events and may provide potential indices for future research.

[Floating thrombus in the carotid]. / Thrombus flottant dans une carotide.

The cardiogenic origin of stroke is often established on the basis of documented arrhythmia, computed tomographic evidence of cerebral ischemia, duplex Doppler findings ruling out an atheromatous carotid origin, and sometimes visualization of an intracavitary thrombus at transesophageal echocardiography. In case of a large thrombus as observed in our present patient, duplex Doppler provides an important means of visualizing the thrombus despite the lack of a parietal lesions suggestive of atheromatosis.

[Severe and distal ischemia of the upper limb. Results of a surgical follow-up of 11 years in 34 patients]. / Ischémie distale sévère du membre supérieur. Bilan d'un suivi chirurgical de 11 ans chez 34 patients.

The aim of this retrospective study was to evaluate etiology, frequency and prognosis of the distal and severe arterial diseases of the upper limb treated in a vascular surgical unit. Between Jan. 1986 and Jan.1997, 34 patients, 22 males and 12 females, mean age 56 years (range 30 to 87 years) were followed in the vascular and thoracic surgical unit in Angers. Follow-up was 100% complete. Each patient was explored by selective angiography of the upper limb due to the critical characteristic of ischemia.19 patients (56%) had tissue loss. Among multiple etiologies, arteriosclerosis was found in 32% of the cases. When medical treatment was unsuccessful, a thoracic sympathectomy was attempted in 50% of the cases, and 21% of the patients had direct arterial surgery. Nine deaths, due to initial pathology, occurred during follow-up. Eight digitalis amputations were carried out whose two directly because serious necrosis. Severe arterial diseases of the upper limb represented 6, 4% of critical limb ischemia treated during this same period. At time, this study showed arteriosclerosis preponderance over systemic diseases, and the seriousness of cases referred to a vascular surgical center after unsuccessful medical treatment (J Mal Vasc 1999; 24: 368-372).