The thrombosed prosthetic graft is a risk for infection of an adjacent graft.

BACKGROUND: A bland thrombosed graft may be more susceptible to the future risk of infection than a patent graft. Once infected, that graft can threaten other patent grafts. Therefore, the purpose of the following study was to assess the role a thrombosed graft might play in infection of contiguous patent bypasses. METHODS: From 1990, a retrospective review was performed using the operative and medical records of cases in which a prosthetic graft infection was identified arising in association with an adjacent thrombosed graft. RESULTS: A total of 22 cases of prosthetic arterial bypass infection were treated at our institution from January 1990 through September 1995. Of these, 7 (32%) were identified by the operative report as arising in a thrombosed prosthetic graft and spreading to an attached or adjacent patent prosthetic graft. All patients had multiple bypasses prior to infection, mean 5.4 +/- .75 (range 3 to 8). All thrombosed infected grafts were infrainguinal polytetrafluoroethylene (PTFE) for limb salvage: 6 femoralpopliteal and 1 femorotibial. Mean interval time between placement of the primarily infected graft and removal was 14.6 +/- 6.7 months (range 1 to 53). The secondarily infected patent bypasses were inflow procedures to the same limb in 6 cases: 1 aortofemoral, 2 ileofemoral, 2 axillofemoral, and 1 femoral femoral graft. The thrombosed infrainguinal bypass was directly attached to the secondarily infected bypass in 5 cases and near but not attached in 1 case. One secondarily infected prosthetic graft was a femoraldistal bypass placed adjacent to the thrombosed graft. Four patients had above-knee amputations with a clinically bland graft divided at the time of amputation. In these 4 patients and 2 additional cases, wet gangrene or infection was present in the distal extremity prior to the development of prosthetic graft infection. At the point that infection became clinically apparent, the thrombosed graft was removed in all cases and the secondarily infected graft was removed in 4 of 7 cases. Overall mortality was 57%. CONCLUSIONS: A thrombosed prosthetic graft near a patent prosthetic bypass may become secondarily infected and threaten the patent graft. We recommend total removal of any thrombosed prosthetic graft in proximity to a patent prosthetic bypass when the risk of infection is high or at the time of subsequent amputation for gangrene.

Evaluation and treatment of carotid stenosis in open-heart surgery patients.

Indications for identification and treatment of extracranial carotid artery disease in candidates for open-heart surgery (OHS) remain unsettled. We evaluated the efficacy of OPG-GEE screening and our nonrandomized use of carotid endarterectomy in 2312 OHS patients from 1975 to 1989. Data was analyzed using the chi 2 squared and Fisher's exact tests. OPG was performed in 1602/2312 (69%) of the patients. OPG was positive in 122/1602 patients (7.6%) and negative in 1480/1602 (92.4%) patients. Of the patients with positive OPG, 31 patients had insignificant carotid bifurcation disease, 32 patients had total internal carotid artery occlusion, and 59 patients had operable carotid bifurcation lesions. Selective use of angiography identified an additional 8 patients with operable carotid bifurcation lesions (total 67, 33 symptomatic and 34 asymptomatic). Overall stroke rate for 2312 patients was 40/2312 (1.7%) [30 day mortality rate 60/2312 (3.2%)]. Stroke incidence was significantly increased (P < 0.01) in patients with a positive OPG, 8/122 (6.60%) vs those with negative OPG (23/1480, 1.6%). However, it was most marked in patients with operable bifurcation lesions (6/67, 9.0%). Stroke was not increased in patients with carotid occlusion or positive OPG without significant carotid bifurcation disease (2/63, 3.20%). Carotid endarterectomy in patients with operable bifurcation lesions was associated with a decreased (P < 0.05) stroke rate after OHS (1/44, 2.30% vs 5/23, 21.7%). Our data suggests identification of significant carotid disease and carotid endarterectomy will decrease stroke after OHS.

Progression of arteriosclerotic disease in the failed infrainguinal bypass.

Thirty-three male patients had 34 infrainguinal bypass for ischemic arterial disease that became occluded. The indications for surgery were severe disabling claudication in 22 (65%) legs and rest pain in 12 (35%) legs. Twenty-three (68%) of the bypasses were above the knee and 11 (32%) bypasses were below the knee. Reversed saphenous vein was used in 16 (47%) bypasses and polytetrafluoroethylene (PTFE) in 18 (53%) bypasses. The mean ankle pressure index prior to the bypass was 0.40 and the post-operative mean ankle pressure index was 0.86. The arterial bypasses remained patent from 1 month to 47 months (mean, 17.7 months). The reversed saphenous vein remained patent for a mean period of 21.3 months and the PTFE for a mean period of 10.6 months. This difference was statistically significant (P greater than .01). After occlusion of the bypasses, arteriography was performed. The postocclusion arteriography was compared with the pre-bypass arteriography. There was significant progression of arterial disease to account for the failure of bypasses in the inflow arteries in three (8.8%) patients and in the arteries distal to the bypasses in 23 (67.6%) patients. Eight patients showed no significant changes in the postocclusive arteriography. In this series of 33 patients with 34 infrainguinal bypasses, 76.5 per cent of the patients developed progression of the arterial disease causing failure of the bypasses. The reversed saphenous vein bypasses remained patent twice longer than the PTFE.

The risk of perioperative stroke in patients with asymptomatic carotid bruits undergoing peripheral vascular surgery.

Three hundred patients without neurologic symptoms had 374 elective peripheral vascular procedures and they were screened preoperatively for incidental asymptomatic carotid bruits prior to surgery. The bruits were hemodynamically evaluated with the GEE-OPG. A bruit was considered hemodynamically significant if the OPG test was positive. Seventy-four patients (24.7%, 74/300) were found to have 118 carotid bruits. Twenty-five (22.3%, 25/112) of the 112 bruits with OPG studies were hemodynamically significant. There were three perioperative strokes that occurred for an incidence of 0.8 per cent (3/374). There was no stroke in patients without bruits and with nonhemodynamically significant bruits. The incidence of perioperative stroke in patients with hemodynamically significant bruits was 16 per cent (3/19). There is a subgroup of patients with hemodynamically significant carotid bruits who are at high risk for perioperative stroke.

The asymptomatic carotid bruit.

Management of the asymptomatic carotid bruit remains a controversial subject. The purpose of this study is to determine whether or not such bruits are important risk factors in the evolution of stroke. Since April 1977, 87 patients with 131 asymptomatic carotid bruits were evaluated with the Gee oculoplethysmography (OPG). Eleven bruits (8.4%) were hemodynamically significant (ophthalmic artery/brachial artery systolic pressure index below 0.69 or a difference of 5 mm Hg or more between the eyes). The patients were reevaluated at 6-month intervals. The mean follow-up was 34 months (range, 1-60 months). During this period, 14 bruits (11.6%) that initially were nonhemodynamically significant (NHS) later became hemodynamically significant (HS). Patients with asymptomatic carotid bruits had a stroke incidence of 10.3 per cent. Patients with HS bruits had a stroke incidence of 24 per cent and a transient ischemic attack (TIA) incidence of 16 per cent, which were significantly higher (P greater than 0.01) compared to the patients with NHS bruits (4.8% incidence of stroke and 3.2% incidence of TIA). Nine patients (10.3%) developed strokes without antecedent TIA and six patients (6.9%) developed TIA. The strokes occurred in the cerebral hemisphere supplied by the carotid artery with HS bruit in three of six patients. The strokes in three patients with NHS bruits were on the same side of the bruits. The TIAs developed in four patients with HS bruits and in two patients with NHS bruits. The authors conclude that the patient with an asymptomatic HS carotid bruit has a high risk of developing a stroke and that surgical treatment is warranted.

Iatrogenic entrapment of the femoropopliteal bypass.

Three cases of infragenicular femoropopliteal bypass grafts are presented in which iatrogenic entrapment of the distal portion of the graft occurred between the medial head of the gastrocnemius muscle and the posterior surface of the tibia. The condition should be suspected if ischemia of the leg develops postoperatively when the knee is hyperextended and is improved when the knee joint is flexed. Measurements of the ankle pressure index or Pulse Volume Recorder tracings at the ankle in both flexed and extended positions will confirm the diagnosis. The entrapment of the bypasses in these three patients was easily corrected by transection of the medial head of the gastrocnemius muscle. Relief of the occlusion of the bypass can be easily demonstrated by noninvasive studies.

Oculoplethysmography. Evaluation of patients with transient ischemic attacks from internal carotid artery disease.

Oculoplethysmography was used to evaluate 66 patients with transient ischemic attacks prior to cerebral angiography. Fifty-eight (87.9%) symptomatic internal carotid arteries had anatomically significant stenosis. Only 69 per cent of these 58 arteries had positive OPG test. Thirty-one per cent of the arteries were well compensated hemodynamically with collaterals and had a false negative test. A negative OPG test does not rule out an anatomically significant internal carotid artery stenosis.

Noninvasive screening for asymptomatic carotid artery disease prior to cardiac operation. Experience with 500 patients.

Five hundred patients scheduled for cardiac operations underwent preoperative screening for asymptomatic carotid artery disease by means of the Gee ocular pneumoplethysmograph (OPG). Only patients with abnormal OPG measurements (5 mm Hg difference or greater in ophthalmic artery pressures or 0.69 or less ophthalmic artery/brachial artery pressure ratio) had cerebral angiography regardless of the presence or absence of a carotid bruit. Thirty-two patients (6.4%) were found to have carotid bruits. Nine patients had abnormal OPG measurements. Cerebral angiograms disclosed that six of these patients had significant (greater than 50%) carotid artery stenosis, and endarterectomy was performed prior to cardiac operation without incident. Nine other patients without carotid bruits had abnormal OPG measurements, and they also underwent cerebral angiography. Angiograms revealed significant carotid artery stenosis in three patients and prophylactic endarterectomy was performed. Twenty-three patients with carotid artery bruits and normal OPG measurements did not have cerebral angiography prior to the cardiac procedure. The incidence of stroke in this series of 500 patients was 0.4% (two patients). The clinical management of patients with asymptomatic carotid artery disease and coronary artery disease was facilitated by the use of noninvasive screening for the evaluation of carotid artery bruits. Patients with hemodynamically insignificant carotid disease, verified by OPG measurements, can be spared the risk and cost of cerebral angiography. Patients without clinical signs of carotid artery disease can also be identified.

Toe pulse study in ischemic arterial disease of the legs.

The toe pulse reappearance time study for ischemic arterial disease of the lower limb is an easy and accurate test which has great usefulness as a rapid screening method. It is well tolerated by the patients with ischemic arterial disease. Results of the test reflect the total blood flow, including that through the collateral vessels. They determine the severity of the occlusive arterial disease of the lower limb but do not determine the specific levels of arterial occlusion. A principle area of usefulness of the test is for patients who cannot exercise, such as those with a painful ulcer, incapacitating claudication and cardiopulmonary disease.

Factors that affect the outcome of peripheral arterial embolization.

To find the factors that significantly affected prognosis in patients with peripheral arterial thromboembolism, we reviewed a 12-year experience at two hospitals. Sixty-one patients had 67 embolectomies. Operative treatment and management preserved the limbs in 75.8%. Mortality was 22.4%. Outcome was favorably affected when age was less than 60 years and when arteriosclerotic heart disease was absent, and was adversely affected when common femoral emboli were present and hematocrit level elevated. Duration of symptoms did not affect outcome. Our treatment of patients with peripheral embolism is based on the effect of certain intrinsic factors on the formation of distal thrombus. These factors may be more important than duration of symptoms. Immediate, complete heparinization is recommended to arrest thrombosis, and to allow both for proper emphasis on treatment on the often-associated cardiopathy and for attention to hydration and acid-base balance. This preoperative plan of therapy should produce maximal limb salvage with reduced operative mortality.

Obturator foramen bypass in the management of infected vascular prostheses.

Seven patients with infected vascular prostheses in the femoral region were treated by removal of the prosthesis and extraanatomic reconstruction by way of the obturator foramen. Because the operation avoided entry into the infected area, it was considered the best surgical treatment for these patients. Although catastrophic hemorrhage and systemic sepsis were averted, amputation was eventually necessary in five patients, usually because of severe arteriosclerotic disease in distal arteries. Short-term benefit was gained by only two patients. The prevention of infection demands intensive preoperative preparation using prophylactic antibiotics and meticulous operating room technic.