Biomedical subjects

M H Meissner

Publications and source records attributed to M H Meissner.

23 records · Page 2Linked to original sources

PubMed1995

Propagation, rethrombosis and new thrombus formation after acute deep venous thrombosis.

PURPOSE: The purpose of this study was to determine the incidence, timing, and outcome of further thrombotic events after an initial episode of acute deep venous thrombosis. METHODS: Venous thrombi in 204 lower extremities (177 patients) were monitored with duplex ultrasonography at intervals of 1 day, 7 days, 1 month, every 3 months for 1 year, and yearly thereafter. RESULTS: Among initially involved extremities, propagation to new segments occurred in 61 (30%) and rethrombosis occurred in 63 (31%). Both propagation and rethrombosis, in different segments, occurred in 27 (13%) extremities. New thrombi were also noted in nine (6%) initially uninvolved extremities. These events were not associated with identifiable clinical risk factors, although extremities with rethrombosis were more extensively involved at presentation. Propagation in initially involved extremities was an early event, occurring within a median of 40 days in all segments. New thrombotic events in initially uninvolved extremities and rethrombosis occurred as later events. The development of reflux was significantly more common among all initially uninvolved segments to which thrombus extended and among mid and distal superficial femoral and popliteal artery segments with rethrombosis. CONCLUSIONS: Recurrent thrombotic events are common after acute deep venous thrombosis and adversely affect the ultimate development of valvular incompetence. Their occurrence is unrelated to recognized clinical risk factors and can occur despite standard anticoagulation measures.

Acute Disease↗

PubMed1994

A comparison of the cuff deflation method with Valsalva's maneuver and limb compression in detecting venous valvular reflux.

OBJECTIVE: This study was designed to test the results of Valsalva's maneuver and limb compression against the standing-cuff inflation-deflation method for the detection of venous valvular reflux. DESIGN: The study was conducted in 67 patients (134 extremities) who had an episode of deep vein thrombosis. An ultrasonic duplex scanner was used to evaluate two methods of testing for reflux. The most commonly used methods are Valsalva's maneuver and limb compression, both of which can raise the venous pressure and promote reflux. With the cuff method, the patient is studied in the standing position. The cuffs are segmentally placed (thigh to foot) with reflux encouraged when the inflated cuff is suddenly deflated. SETTING: The patients were a part of a long-term natural history study of acute deep vein thrombosis and its effects on venous valve function. OUTCOME MEASURES: Valvular reflux was documented by the appearance of retrograde flow in the vein when the normal transvalvular pressure gradient was reversed. RESULTS: Both limb compression and Valsalva's maneuver can elicit reflux, but the maneuvers are difficult to standardize and come up with meaningful results. With the cuff inflation-deflation method, the time to valve closure was less than 0.5 seconds in 95% of normal subjects. The results were easier to quantify and worked well for all segments of the venous systems--superficial and deep. CONCLUSIONS: The cuff inflation-deflation method provides more uniform quantifiable results for detecting reflux in the superficial and deep veins of the leg.

Acute Disease↗

PubMed1994

Venous diameter and compliance after deep venous thrombosis.

Duplex sonography was used to measure diameters of the common femoral, superficial femoral, and popliteal veins in 56 patients followed for more than 6 months after DVT and in 17 normal subjects. Diameter changes with Valsalva's maneuver were also measured as an index of venous compliance. Among patients with unilateral thrombosis, segments with residual disease were 0.07 to 0.28 cm smaller than the contralateral disease-free side (p < 0.05 for CFV and SFV) with a diameter index (ipsilateral/contralateral diameter) significantly less than that of normal subjects. In contrast, completely recanalized segments were not significantly different from the contralateral side and had diameter indices indistinguishable from normal subjects. Distensibility with Valsalva's maneuver was not significantly different from normal in DVT patients with either resolved or residual disease. Venous diameter does decrease following DVT, but returns to normal following complete recanalization and is not associated with chronic venous compliance changes.

Adolescent↗

PubMed1993

Deep venous insufficiency: the relationship between lysis and subsequent reflux.

PURPOSE: Although venous valvular insufficiency is well recognized as the most important etiologic mechanism in the development of the postthrombotic syndrome, the factors contributing to valve incompetence after deep venous thrombosis remain obscure. METHODS: To establish the relationship between recanalization and valve competence, 113 patients with acute deep venous thrombosis were studied with serial duplex ultrasonography. RESULTS: Median lysis times for segments developing reflux (214 to 474 days) were 2.3 to 7.3 times longer than for corresponding segments not developing reflux (65 to 130 days) for all except the posterior tibial vein. In the posterior tibial vein, median lysis times for those with and without reflux were nearly identical (72 vs 80 days). The median time to onset of reflux was significantly less than the median lysis time in the mid and distal superficial femoral veins and was simultaneous with recanalization in all other segments. CONCLUSIONS: Early recanalization is important in preserving valve integrity for all but the posterior tibial segment. However, the small number of patients with reflux despite early lysis (< 1 month) or without reflux despite relatively late lysis (> 9 to 12 months) suggests that other factors may also contribute to the development of valvular incompetence. These factors may be particularly important in the posterior tibial vein, in which lysis time has little relationship to the ultimate development of reflux.

Adolescent↗

PubMed1992

Colon infarction after ruptured abdominal aortic aneurysm.

Colon infarction is a lethal complication of ruptured abdominal aortic aneurysm. We compared multiple anatomic, hemodynamic, and clinical features in 25 patients with ruptured abdominal aortic aneurysm who suffered colon ischemia and 25 initial survivors of ruptured abdominal aortic aneurysm in whom this complication did not develop. Prior impressions notwithstanding, preoperative shock or volume administration did not correlate with the development of colon ischemia, nor did aneurysm location, cross-clamp site, graft type, or inferior mesenteric artery patency. However, patients with colon ischemia had a significantly lower perioperative cardiac output and were significantly more likely to have received alpha-adrenergic vasoconstrictor agents. Seventeen patients (68%) with colon ischemia died compared with nine patients (36%) without colon ischemia. Perioperative maintenance of cardiac output and avoidance of alpha-adrenergic vasopressor agents are critical elements in prevention of this lethal complication.

Aged↗