Henry D. Berkowitz

Popliteal artery aneurysms: Current management and outcome

PURPOSE Thrombosis of popliteal artery aneurysms can produce limb-threatening ischemia. In this setting we have found preoperative thrombolytic therapy to be beneficial. METHODS Thirty-three patients with 54 popliteal artery aneurysms were studied (mean follow-up 62 months). Twenty-one patients (62%) had bilateral popliteal artery aneurysms, and 20 patients (61%) had extrapopliteal arterial aneurysms. Thirty-three (61%) aneurysms had symptoms of compression or ischemia, and 21 (39%) aneurysms had thrombosis. A trend toward thrombosis for larger aneurysms was noted (p < 0.068). RESULTS Forty-five aneurysms were treated with bypass grafting. Five-year graft patency and limb salvage rates were 71% and 90%, respectively. Factors favoring graft patency and limb salvage included presence of two- or three-vessel runoff compared with patients with single- or no-vessel runoff (p < 0.025 graft patency; p < 0.003 limb salvage) and presence of a patent aneurysm (p < 0.005 graft patency and limb salvage). Seven patients diagnosed with thrombosis of their aneurysm and all runoff vessels were treated with preoperative thrombolytic therapy. Complete clearing of thrombus from these arteries was achieved in six of these patients (and from two of these runoff vessels in the remaining patient). These patients had better graft patency (p < 0.005) and limb salvage (p < 0.01) than comparable patients treated with emergency operations. Six amputations were performed in the follow-up interval, none of which were performed in patients having undergone thrombolytic therapy. CONCLUSIONS It is concluded that popliteal aneurysms are managed best by elective repair of patent aneurysms with good runoff. In that difficult situation of the thrombosed popliteal artery aneurysm associated with acute leg ischemia, thrombolytic therapy safely and effectively provides patients with a more favorable alternative than emergency surgery.

Magnetic resonance angiography of peripheral runoff vessels

Recent improvements in magnetic resonance imaging techniques have made magnetic resonance angiography (MRA) a very useful adjunct to invasive angiography. Fifty-five limbs in 51 patients with occlusive peripheral vascular disease were studied with both MRA and contrast arteriography. The magnetic resonance and contrast arteriograms were read by radiologists and surgeons and separate interventional plans were based on each study. The MRA findings differed significantly from those of conventional arteriography in 26 limbs (48%). In every case MRA visualized all of the same vessels and hemodynamic stenoses seen on the contrast arteriogram. In 48% of the cases, however, MRA revealed additional findings. Thus the discrepancies in the two studies were always the result of the failure of the arteriogram to reveal all of the patent vessels seen on MRA. The additional information provided by MRA resulted in alteration of the interventional plan in 11 cases (22%). In nine cases (18%) target vessels suitable for use in a limb-salvage procedure were identified by MRA, although they had been missed by conventional arteriography. In all of these cases, intraoperative arteriograms confirmed the suitability of these vessels for use in technically successful bypass procedures. In two cases (4%) additional information provided by MRA identified a target runoff vessel for bypass grafting that proved to be a better alternative than the one that would have been chosen on the basis of contrast arteriography.(ABSTRACT TRUNCATED AT 250 WORDS)

31P nuclear magnetic resonance spectroscopy: Noninvasive biochemical analysis of the ischemic extremity☆☆☆

The biochemical effects of peripheral vascular disease on skeletal muscle have not been characterized precisely because of the lack of satisfactory noninvasive analytic methods. 31P nuclear magnetic resonance (NMR) spectroscopy was used to measure the high-energy phosphate compounds, phosphocreatine (PCr) and adenosine triphosphate, as well as metabolic byproducts, such as inorganic phosphates (Pi) and phosphate monoesters in calf muscles of 214 limbs with peripheral vascular disease. Intracellular pH was also measured. The NMR index (Pi[PCr + Pi]) was used to quantitate the impairment of oxidative phosphorylation as a result of ischemia. Studies done at rest documented the impairment of oxidative metabolism only in limbs with severe ischemia (ankle-brachial pressure index (API) less than 0.4). Exercise resulted in a significant elevation of the NMR index in all limbs and the rate of return of this value toward normal following exercise was prolonged even in limbs with moderate ischemia (0.4 less than or equal to API less than or equal to 0.9). Correlation of 31P NMR parameters with arteriograms showed that infrapopliteal occlusions resulted in prolonged recovery times only when the superficial femoral artery was occluded and emphasized the metabolic consequences of multisegmental disease. Accumulation of glycolytic pathway intermediates correlated with the decrease in muscle cell pH observed with exercise. Despite immediate improvement in symptoms and hemodynamic parameters following revascularization, return to normal biochemical function occurs over a prolonged period of time. This study demonstrates that 31P NMR spectroscopy can successfully measure noninvasively the important phosphorus-containing compounds involved in the bioenergetics of skeletal muscle in vivo rapidly enough to permit real-time determination during exercise and recovery.

Late failure of reversed vein bypass grafts.

Late failure of reversed vein bypass grafts is preceded by the appearance of stenotic lesions, which progress to total occlusion. These lesions appear either as intrinsic graft lesions or as new arteriosclerotic lesions in contiguous arteries. The present study summarizes the University of Pennsylvania experience with these lesions in 521 vein grafts inserted from 1979 to 1985. The grafts were grouped according to the site of the distal anastomosis; 231 above-knee popliteal (FP AK), 171 below-knee popliteal (FP BK), and 119 tibial (FT). The overall incidence of stenotic lesions was essentially identical with the three grafts (21%), but the relative incidence of intrinsic graft to arterial lesions was higher with the more distal grafts. The most common graft lesions developed adjacent to the proximal anastomosis, which is the narrowest part of a reversed vein graft. The popliteal artery was the most common site of outflow stenosis. There was negligible incidence of tibial lesions. The most common inflow arterial lesion was located in the common femoral and iliac arteries. The superficial femoral artery (SFA) was a rare site of inflow stenosis, even though it was at risk because 96 grafts originated from the SFA or popliteal artery. Sixty-seven per cent of the graft and 52% of the arterial lesions were treated successfully by percutaneous transluminal angioplasty; the rest had minor surgical revisions. This resulted in a 19%, 10%, and 9% improvement in 5-year patency for the FT, FP BK, and FP AK bypasses. These results justify an aggressive policy of graft surveillance to identify and treat stenotic graft lesions before graft occlusion.

Results of 100 consecutive femoropopliteal vein grafts for limb salvage.

One hundred consecutive patients with femoropopliteal autogenous vein grafts for limb salvage were reviewed five years later. In this group 40% died and 30% of the limbs had been lost at the end of five years. Limb survival correlated best with adequacy of distal run-off, but not with the presence or absence of diabetes. Forty-seven per cent of the grafts were still patent among surviving patients, and when combined with the limbs that were viable despite failure of the original graft, 70% of the limbs were salvaged among the survivors at five years. Temporary graft patency was effective in preserving ischemic tissue by facilitating healing of ulcers or limited amputations. Femoral-popliteal bypass grafting in the presence of advanced ischemia is capable of improving the quality of life for many of these patients.

Femoropopliteal vein grafts for claudication. Analysis of 100 consecutive cases.

One hundred consecutive femoropopliteal venous grafts in 85 patients with claudication were followed for five years. At this time, three limbs had been amputated, approximately one quarter of the patients had expired, and 70% of the grafts in surviving patients remained patent. It is concluded that this operation does not appear to increase the risk of amputation and in fact, may lessen it. Moreover, it is associated with minimal risk and generally provides long-term relief of claudication, thus enhancing the quality of life in most patients.

Transluminal Angioplasty of the Iliac, Femoral, and Popliteal Arteries

The recently developed Grüntzig balloon dilatation catheter has facilitated the performance of transluminal angioplasty. The authors used this catheter in 35 arteries supplying the lower extremities in 27 patients. Immediate relief of symptoms (claudication and rest pain) occurred in 30 vessels (86%) in 23 patients. The procedure was well tolerated by all patients. Over 90% of initially successful dilatations were patent at 3 to 10 months.

Fluorochemical perfusates for renal preservation.

Abstract We have evaluated the use of dispersed fluorochemicals in cryoprecipitated plasma as a perfusage for renal preservation. FC-43(47) has been shown to be a superior perfusate to FX-80 despite its lower oxygen binding capacity. Significant improvement in survival of transplanted kidneys following 24 hr hypothermic perfusion was experienced with the FC-43(47). When comparing the FC-43(47) dispersion with plasma, no significant differences were found in the perfusion characteristics of the kidney while on the perfusion apparatus aside from the creatinine clearances which were significantly higher with the fluorochemical perfusate. One hundred percent of the kidneys perfused with the FC-43(47) perfusate survived with normal creatinines at the end of 30 days compared to only 27% perfused with FX-80 and 62% perfused only with plasma. The maximum creatinine that developed with FC-43(47) was not significantly different from the value obtained with the plasma perfusates. While these experiments do not clearly establish fluorochemical perfusates as superior to plasma, they indicate that in longer term perfusions of 48 and 72 hr a significant difference may be observed.

Early experience with percutaneous transluminal angioplasty using a vinyl balloon catheter.

The technique of transluminal dilatation of arterial stenoses has been greatly facilitated with the recent development of the vinyl balloon catheter by Gruntzig. Since these catheters became available to us in early 1978, we have utilized them to attempt dilatation of 62 arteries, including iliac, femoral and renal vessels. Immediate success was achieved in 57 of these vessels. There were five early complications (two distal embolizations and three prompt occlusions) and three late complications (two restenoses and one occlusion at ten days). The occlusions were all treated promptly surgically with good results and the stenoses redilated. Noninvasive pressure measurements were obtained on all patients whose iliac or femoral arteries were dilated both before and after the procedure, with objective improvement demonstrated by this method. The procedure itself is well tolerated by patients. It involves only minimal discomfort and risk and a markedly shortened hospital stay. The procedure can be easily accomplished by physicians who are thoroughly familiar with routine femoral catheterization techniques and it is believed that this technique will have a definite place in the future therapy of many cases of arterial stenosis.

Carotid endarterectomy in patients with heparin-induced platelet activation: comparative efficacy of aspirin and iloprost (ZK36374)

Patients with heparin-induced platelet activation who are reexposed to heparin may have recurrent thrombocytopenia, intravascular thrombosis, arterial emboli, or sudden death. To permit carotid endarterectomy in two patients with confirmed heparin-induced platelet activation, we compared the efficacies of aspirin and iloprost, a stable analogue of prostacyclin, in preventing heparin-induced platelet activation. In the first patient, although aspirin prevented both in vitro heparin-induced platelet aggregation (70% without and 7.5% with aspirin) and 14C serotonin release (48% without and 0% with aspirin), intraoperative administration of heparin resulted in an increase in plasma levels of platelet factor 4 from 8 to 260 ng/ml and beta-thromboglobulin levels from 29 to 39 ng/ml. In addition, the circulating platelet count decreased from 221,000 to 174,000 microliters, and 15% spontaneous platelet aggregation was observed. Fortunately, fibrinopeptide A levels remained less than 10 ng/ml intraoperatively, and no thrombotic complications occurred. In the second patient, aspirin did not prevent heparin-induced platelet aggregation in vitro (65% without and 41% with aspirin); however, iloprost (0.01 mumol/L) prevented both in vitro heparin-induced platelet aggregation (59.5% without and 0.0% with iloprost) and 14C serotonin release (56.7% without and 0.0% with iloprost). Therefore, a continuous infusion of iloprost was begun before administration of heparin and was continued until 20 minutes after reversal of heparin with protamine. After intraoperative administration of heparin, plasma levels of platelet factor 4 increased from 19 to 200 ng/ml, and beta-thromboglobulin levels increased from 56 to 76 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)