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The purpose of this study was to determine the effect of anticoagulation on the incidence of thrombotic propagation and pulmonary embolism in patients with calf vein thrombosis after total hip or total knee arthroplasty. Patients undergoing arthroplasties had prospective surveillance for postoperative deep vein thrombosis by both bilateral contrast venography and venous duplex scanning. Calf vein thrombosis was documented by venography in 42 patients (50 limbs), including 29 of 253 patients undergoing total hip arthroplasty (11.4%) and 13 of 99 patients undergoing total knee arthroplasty (13%). Of patients on whom follow-up duplex scans were performed, heparin followed by warfarin anticoagulation was used in 11 (13 limbs) and withheld in 21 (25 limbs). Propagation of thrombosis to the popliteal or superficial femoral vein or both was detected by serial duplex scanning in 3 of 13 treated limbs (23%) and 2 of 25 untreated limbs (8%), (p = 0.43). All thrombus propagations were detected within 2 weeks of the operative procedure. There were no pulmonary emboli or deaths. Propagation of asymptomatic calf vein thrombosis after arthroplasty was not influenced by anticoagulation, suggesting that postoperative calf vein thrombosis need not be routinely treated. Serial venous duplex scanning is useful to identify the occasional patient in whom thrombotic propagation requiring anticoagulation develops.

Vascular surgeons are often consulted on the management of lower extremity ulcerations and gangrene which are commonly due to atherosclerotic arterial occlusive disease or to chronic venous insufficiency. The following report describes an unusual case of severe lower extremity cutaneous gangrene associated with secondary hyperparathyroidism and a review of the literature.

A foot arterial resistance index (FARI), determined plethysmographically, was used pre- and postoperatively to compare foot vasomotor tone following arterial reconstructions of the lower limb with and without the addition of lumbar sympathectomy. The index was measured before and during reactive hyperaemia in 40 patients without vascular disease; in 32 patients who underwent aortic reconstructions, 14 of whom were randomly subjected to a concomitant bilateral lumbar sympathectomy; and in 8 patients who had a femoropopliteal bypass for limb salvage. This study indicates that the addition of lumbar sympathectomy to aortic reconstructive operations enhances blood flow to the foot by significantly reducing foot vasomotor tone. Sympathectomy performed to reduce foot arterial resistance in patients undergoing successful femoropopliteal reconstructions may be of no benefit since a persistent marked postoperative hyperaemia of the foot is present.

A new strain gauge plethysmography was developed to permit accurate electrical calibration and automatic calculation of limb blood flow from a panel meter. This instrument was used to quantitate maximum venous outflow (MVO) in both limbs of 20 normal volunteers and 387 limbs of 195 patients with clinically suspected leg vein thrombosis. The MVO of normal subjects averaged 45 +/- 18 cc/minute/100 cc of calf tissue (mean +/- 1 SD). In 69 limbs with deep vein thrombosis documented by Doppler ultrasound and/or phlebography, the MVO averaged 17 +/- 13 cc/minute/100 cc, which was significantly less than that of normal limbs (p less than 0.001). Only three of 31 limbs with venous thrombosis above the knee had MVO above 20 cc/minute/100 cc, the lower limit of normal, for a diagnostic sensitivity of 90%. The specificity of a normal MVO in excluding deep vein thrombosis was 81%, with only a 1% rate of false-negative diagnoses above the knee. This automatic strain gauge plethysmograph has the attribute of providing rapid quantitation of limb venous hemodynamics which facilitates noninvasive diagnosis and follow-up assessment of venous disease.

Strain gauge plethysmography has permitted noninvasive quantitation of altered venous hemodynamics in the legs of patients with venous disease. A new plethysmograph has been developed which avoids previous problems of mechanical calibration of gauges and the necessity for a recorder for calculating blood flows. This instrument permits accurate electrical calibration of mercury-in-Silastic gauges which are effectively at the corners of the Wheatstone bridge and are supplied by constant current for linear output. A timer and follow-and-hold circuit allow automatic calculation of rates of change in limb circumference and, thus, blood flow, from a panel meter. The accuracy of the automatic versus the graphic methods of quantitating venous outflow and reflux flow was determined in 20 normal subjects. Venous outflows were 15.1 +/- 0.5 (mean +/- 1 S.E.M.) and 15.9 +/- 0.4 cc/min/100 cc by automatic and graphic methods, respectively (r = 0.96, p less than 0.01). Reflux flows were 2.1 +/- 0.2 and 2.3 +/- 0.2 cc/min/100 cc by the automatic and graphic methods, respectively (r = 0.93, p less than 0.01). This plethysmograph may prove to be a simple, rapid, and accurate device for evaluating altered hemodynamics in venous disease.

Preoperative Doppler ultrasonic assessment of below-knee (BK) arterial signals and systolic blood pressures was performed on 50 patients undergoing 53 BK amputations for advanced ischemia. No patient was excluded from initial BK amputation unless gangrene at that level or severe joint contracture was present. Failure of healing of the BK amputation occurred in all five limbs with an undetectable Doppler arterial signal (and thus pressure) below the knee. Failure of amputation occurred in four of 16 limbs with detectable arterial signals and BK pressures less than 70 mm. Hg. Healing occurred in all 32 limbs with BK pressures greater than 70 mm. Hg. The differences in healing between these three groups are highly significant (p less than 0.005). This study suggests that Doppler ultrasonic assessment of BK arterial signals and pressures may be a simple hemodynamic correlate of healing of a BK amputation. Absence of a detectable arterial signal below the knee may be an indication for initial above-knee (AK) amputation in advanced ischemia.

A 5 MHz continuous-wave Doppler probe was used intraoperatively to evaluate 25 in situ saphenous vein bypass grafts. At least one arteriovenous fistula per case and five retained competent posterior valvular leaflets were identified before completion angiography. The Doppler was able to distinguish a retained valve from an arteriovenous fistula on clinical grounds but not by waveform analysis. Intraoperative assessment of in situ saphenous vein bypass grafts with the continuous-wave Doppler can identify retained valves that might be missed by angiography. It can reduce the number of angiograms needed to demonstrate a technically perfect result, thus saving operative time and contrast agent load to the patient.

The efficacy of segmental limb blood pressure measurements, assessed noninvasively by Doppler ultrasound, in predicting the result of aortofemoral reconstruction was evaluated in fifty-two extremities with varying extent of aortoiliac and more distal arterial occlusive disease. Three prognostic correlates were analyzed: (1) preoperative proximal thigh/arm pressure index (TPI); (2) preoperative pressure gradient between adjacent leg segments (proximal thigh, above-knee, below-knee, and ankle), normally less than 30 mm Hg; and (3) early postoperative increase in the ankle/arm pressure index (API). After aortofemoral bypass, forty-one limbs (79 per cent) were asymptomatic or improved and eleven were unimproved. The mean TPI in extremities benefiting from aortofemoral bypass, 0.82 +/- 0.17 (+/-1SD) was significantly less than that of unimproved limbs, 1.01 +/- 0.09 (p less than 0.01). Aortofemoral bypass was beneficial in all twenty limbs with normal leg pressure gradients. Conversely, six of twenty-five legs with one abnormal gradient and five of seven with two abnormal gradients failed to improve. The postoperative increase in API was 0.1 or more in all forty-one improved extremities and was less than 0.1 in all eleven failures. Although eleven of thirty-two limbs (34 per cent) with arteriographic evidence of combined aortoiliac and subinguinal occlusive disease were not improved after proximal bypass, the result of operation could not be predicted from the angiographic pattern or severity of distal disease. Segmental limb blood pressures provide useful predictive indices of the efficacy of aortofemoral bypass and the potential need for more distal reconstruction in multisegmental disease.

Segmental limb blood pressures (BPs) measured by Doppler ultrasound and digit photoplethysmography were used to define hemodynamic correlates of wound healing in 122 lower-extremity amputations for ischemia. Healing of digit or transmetatarsal amputations were influenced by the presence of diabetes and correlated better with digit pulsation and BP than with ankle pressure. Healing of below-knee amputation did not correlate with segmental limb BPs. In the absence of an absolute threshold to predict wound healing or failure, caution is urged in using hemodynamic indices to select the level of amputation of arterial insufficiency.

The clinical history and physical examination remain the most important factors in determining the presence, anatomic location, and physiologic extent of arterial occlusive disease and the need for operation. The physician should refrain from ordering arteriography to confirm the diagnosis of arterial disease unless operation is warranted. If peripheral arterial occlusive disease is diagnosed clinically, its anatomic and physiologic extent can be determined qualitatively and quantitatively by Doppler ultrasonic studies. These studies are also useful in following the natural history of or the influence of therapy on the course of arterial occlusive disease. Ultrasonic studies coupled with careful clinical assessment and with arteriographic evaluation prior to planned operation provide an optimal armamentarium for the diagnosis and management of peripheral arterial occlusive disease.