The use of deep duplex scanning to predict hemodynamically significant aortoiliac stenoses.

Hemodynamic assessment of aortoiliac occlusive disease is necessary for successful arterial reconstruction of the aorta and legs. Various methods have been proposed and "pull-through" intra-arterial pressures are the "gold standard." Deep Doppler duplex imaging was supplemented with real-time spectral analysis and velocity measurements in 29 cases. Twenty-three of these patients needed arteriography. One hundred sixty-six (166) arterial segments extending from the proximal aorta to the common femoral arteries were independently graded on duplex scans and arteriograms. For severe occlusive disease, duplex scanning is highly accurate (sensitivity 82%, specificity 93%). Velocity measurements were useful in determining the hemodynamic significance of stenoses. Peak systolic velocities in stenoses were measured with a duplex scanner. The pressure gradient calculated with the modified Bernoulli equation (delta P = 4Vmax2) correlated well with the gradients measured during arteriography (r = 0.9, n = 11). These noninvasive velocity measurements and Bernoulli calculations alert arteriographers to obtain special views of suspected areas and suggest the need for "pull-through" pressures and possible balloon angioplasty. In addition, these noninvasive measurements are useful to follow up patients who have mild to moderate aortoiliac disease and after angioplasty.

Distal arterial reconstruction: patency and limb salvage in diabetics.

Controversy regarding efficacy and durability of distal bypass grafting of the diabetic patient exists. A 22-year-long series of 259 vascular procedures with 100% follow-up (57% in diabetic individuals) is examined to compare these results with those of non-diabetic patients. Extensive review of predisposing factors, operative indications, preoperative medical evaluation, as well as techniques and peculiarities of angiography is rendered. Peripheral arterial case mix between the two groups is examined. The high utilization rate of solely venous conduits (94%) in diabetics compared with 76% in nondiabetics, along with anastomosis site selection, provides the most reasonable explanation for the successful outcome in both groups. Modifications in revascularization techniques contributing to successful outcome are presented. In the diabetic patients, both the cumulative graft patency rate (63%) and the limb salvage rate (77%) at 6 years were superior to those of the non-diabetics (52% and 65%, respectively). Diabetes mellitus does not predispose the person requiring revascularization for limb salvage to a lesser likelihood of success.

Duplex B-mode imaging for the diagnosis of deep venous thrombosis.

Real-time B-mode venous imaging has numerous advantages for the diagnosis of acute deep venous thrombosis (DVT). During the 11 months ending Feb 1, 1986, we examined 431 patients for possible acute DVT using a 5-MHz hand-held continuous wave Doppler stethoscope and a duplex real-time B-mode imager. Clots were seen in 86 patients in multiple views and cross sections. Normal veins completely collapsed with probe pressure on the skin. Blood flow was seen and heard, and abnormal flow was detected. There were no false-negatives (100% sensitivity). Early in the study, two false-positives occurred (78% specificity), but these errors will not recur. These tests are accurate, noninvasive, and inexpensive. They differentiate acute from chronic thrombosis and are repeatable. Duplex imaging may become the "gold standard" for the diagnosis of DVT.

Comparison of initial limb salvage in 98 consecutive patients with either reversed autogenous or in situ vein bypass graft procedures.

A retrospective review of 98 consecutive patients undergoing femoropopliteal or distal bypass procedures was conducted to determine whether in situ bypass grafting offers statistically significant initial limb salvage over reversed autogenous techniques. Over a 40 month period, 98 consecutive patients received either in situ or reversed autogenous vein grafts to effect limb salvage. The groups were similar in incidences of diabetes and previous myocardial infarctions, as well as in site of distal anastomosis (beneath the tibial peroneal trunk in more than 80 percent). The in situ vein graft group had an overall limb salvage rate of 92 percent with an 88 percent cumulative patency rate at 4 to 18 month follow-up, whereas the reversed autogenous vein graft group had a limb salvage rate of 86 percent with a 79 percent cumulative patency rate at up to 18 months. Results after 30 days showed 47 patients had improvement and 3 patients (6 percent) had died in the in situ vein graft group. In the reversed autogenous vein graft group, 44 patients improved, 4 did not improve and required amputations, and 2 (1 percent) died. Our study supports the use of in situ vein bypass grafting for limb salvage.

Surgical implications of fibrinolytic therapy.

Intraarterial fibrinolytic therapy was used in 37 cases (34 patients) of severe peripheral ischemia. Nineteen patients (56 percent) required surgical intervention (5 amputations and 14 successful reconstructive procedures). Twenty-four patients (71 percent) were significantly improved (average ankle-to-arm index 0.84), whereas only 5 patients (15 percent) lost their limbs. Five patients were angiographically unchanged with no or slight improvement in the ankle-to-arm index (0.22 to 0.32) and were discharged on anticoagulant therapy. One death and two cerebrovascular accidents occurred. The usefulness of intraarterial fibrinolytic therapy needs to be evaluated within the total realm of vascular surgery. It offers options for therapy where previously none existed. Some situations might be treated equally well with either intraarterial fibrinolytic therapy or surgery. Finally, surgery might be required to maintain initial successful results with intraarterial fibrinolytic therapy or to rescue intraarterial fibrinolytic therapy failures in striving to achieve superior results in limb salvage.

Distal tibial vein grafts for limb salvage.

Bypasses below the tibial peroneal trunk, which are not commonly performed, are an effective method of limb salvage. We have done long-term follow-up of all 148 consecutive grafts done during the past 19 years. By careful patient selection, detailed arteriograms, utilization of veins from all extremities, meticulous operating technique, and noninvasive follow-up, we have achieved a limb salvage rate of 75% and a cumulative five-year patency rate of 62%. Diabetics made up 53% of the series and did not affect the results. Seventy-one percent of all failures occurred in the first six months. Considering the charges for hospitalization, amputation, prostheses, and rehabilitation, distal tibial bypass procedures are cost-effective.

Vein bypass to the tibial, peroneal and dorsalis pedis arteries for limb ischaemia.

Fifty-nine autogenous vein bypass grafts were performed to the distal leg arteries in 57 patients for limb salvage over a 10 year period.Analysis of results by the Life Table showed a cumulative patency of 74% at 1 month and 59% patency at 6 years. Failure of the vein graft in the early post-operative period resulted in amputation, and in almost 50% of cases, at an aboveknee level. Of 18 patients whose grafts thrombosed, 16 required major amputation, and infection in another 6 patients with patent grafts resulted in limb loss. With these exceptions, all the patients with patent grafts had viable and functional limbs. Of 37 diabetic patients subjected to operation, 17 lost their limbs during follow-up. There was no significant difference in patency of grafts inserted proximally or distally into the tibial vessels. The hospital mortality was 8% and one-fourth of patients subjected to operation died of causes related to atherosclerosis during follow-up.Reduction of the early post-operative failure rate by careful patient selection and meticulous operative technique makes arterial bypass operations to the distal tibial vessels beneficial to many patients who are otherwise doomed to amputation.