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Biomedical subjects

G L Moneta

Publications and source records attributed to G L Moneta.

At least 19 recordsLinked to original sources

Neurologic deficits following noncarotid vascular surgery.

Neurologic events following noncarotid vascular surgery (NCVS) are considered unpredictable. To test this hypothesis, we reviewed our vascular registry for a 3-year period and identified all patients with new postoperative focal neurologic events (stroke, hemispheric transient ischemic attack [TIA]) within 2 weeks of a category I or II vascular procedure as defined by the American Board of Surgery, exclusive of carotid surgery and arterial trauma. Thirteen of 1,390 NCVS procedures (0.9%) in 13 patients were associated with focal neurologic events. There were 2 TIAs, 10 anterior circulation strokes, and 1 posterior circulation stroke. Twenty-seven percent of strokes were fatal. The neurologic deficit developed in the immediate postoperative period in 31%, more than 4 hours but less than 72 hours postoperatively in 54%, and within 3 to 14 days postoperatively in 15%. Patients with anterior circulation events (group A, n = 12) were compared for variables potentially influencing postoperative stroke with case controls who were selected using a table of random numbers (group B, n = 12). Controls were derived from a pool of all category I or II NCVS procedures recorded in our vascular registry sequentially during the same time period and who were without new neurologic deficits postoperatively. Using Fisher's exact test, comparisons between groups A and B revealed that new anterior circulation neurologic events in vascular surgical patients tended to be associated with intra-abdominal procedures (p less than 0.05), perioperative hypotension (p less than 0.05), and the presence of a greater than or equal to 50% internal carotid artery stenosis ipsilateral to the neurologic event (p less than 0.001). Such information may prove useful in the management of selected patients prior to arterial reconstruction and in operated NCVS patients with postoperative neurologic events.

Aged

The incidence of perioperative myocardial infarction in general vascular surgery.

In a 1-year period all patients undergoing general vascular surgery (491 patients, 534 procedures) underwent monitoring by creatine phosphokinase isoenzymes and electrocardiograms (ECG) to detect perioperative myocardial infarction. Only those patients with severe symptomatic coronary artery disease (31 patients, 5.8%) characterized by unstable angina pectoris, uncontrolled arrhythmia, or severe congestive heart failure had any testing for coronary artery disease beyond history, physical examination, and ECG. Only three patients (0.5%) had prophylactic coronary artery bypass performed before general vascular procedures. Twenty-one (3.9%) myocardial infarctions (five asymptomatic, detected by enzymes only, and 16 symptomatic, four of which were fatal) were associated with the 534 procedures (aorta 105, carotid 87, infrainguinal bypass 207, extraanatomic 51, other 84). Eight noncardiac perioperative deaths occurred. All operative deaths (12 of 534, 2.2%) including all four fatal myocardial infarctions occurred associated with surgery on an urgent or emergency basis (12 of 249 procedures, urgent/emergent operative mortality rate 4.8%). No operative deaths and no fatal myocardial infarctions associated with the 285 elective procedures occurred. Nine of the 17 nonfatal myocardial infarctions (53%) also occurred after urgent/emergent procedures. The rate of perioperative myocardial infarctions (eight of 285, 2.8%) after elective surgery in this patient series is no different from that reported by multiple recent authors advocating widespread screening for and prophylactic treatment of coronary artery disease before general vascular surgery. Our experience confirms the therapeutic approach that expensive and invasive coronary screening programs in patients to undergo vascular operations should be limited to carefully selected patients with severely symptomatic coronary disease.

Adult

Surgical management of severe acute lower extremity ischemia.

Seventy-four patients (70 men [95%], 4 women [5%], mean age, 63 years) with severe, acute lower limb ischemia (acute clinical deterioration and absent pedal Doppler signals) caused by either arterial thrombosis (n = 68) or embolism (n = 6) underwent urgent surgical management consisting of operative revascularization with or without amputation in 67 patients (91%) and primary amputation alone in 7 patients (9%). Sixty-one patients (82%) had severely threatened limb viability, and 13 (18%) had major irreversible ischemic limb changes at presentation. Eighty-six percent of patients were initially anticoagulated with heparin. Seventy percent underwent preoperative angiography. Surgical revascularization included 42 inflow and 20 outflow arterial reconstructions and 9 thrombectomy or embolectomy procedures. Mean follow-up was 17 months (range, 0 to 64). Life-table primary patency at 36 months for arterial reconstructions was 81% for inflow and 78% for outflow procedures. Cumulative limb salvage was 70% at 1 month and 68% at 36 months. Patient survival was 85% at 1 month and 51% at 36 months. No death was directly attributable to complications related to limb reperfusion, and no patient required dialysis for myoglobinuria. We conclude that management of severe, acute lower limb ischemia with early amputation of nonviable limbs and heparinization, angiography, and prompt operative revascularization for threatened but viable extremities minimizes morbidity and mortality rates, while maximizing limb salvage. These results may be useful for comparison with comparable groups of patients treated with thrombolytic or endovascular modalities.

Acute Disease

Accuracy of lower extremity arterial duplex mapping.

We performed lower extremity arterial duplex mapping from the aortic bifurcation to the ankle in 150 consecutive patients evaluated for aortic and lower extremity arterial reconstruction and compared lower extremity arterial duplex mapping in a blinded fashion to angiography. On the basis of history, physical examination, and four-cuff segmental Doppler pressures individual lower extremities were classified as normal, isolated aortoiliac disease, infrainguinal disease, and multilevel inflow and outflow disease. For vessels proximal to the tibial arteries, lower extremity arterial duplex mapping was analyzed for its ability to insonate individual arterial segments, detect a 50% or greater stenosis, and distinguish stenosis from occlusion. In the tibial arteries lower extremity arterial duplex mapping was evaluated for its ability to visualize tibial vessels and to predict interruption of tibial artery patency from origin to ankle. Lower extremity arterial duplex mapping visualized 99% of arterial segments proximal to the tibial vessels, with overall sensitivities for detecting a 50% or greater lesion ranging from 89% in the iliac vessels to 67% at the popliteal artery. Stenosis was successfully distinguished from occlusion in 98% of cases. In the tibial vessels lower extremity arterial duplex mapping was better at visualizing anterior tibial and posterior tibial artery segments (94% and 96%) than peroneal artery segments (83%), (p less than 0.001). Overall sensitivities for predicting interruption of tibial artery patency were 90% for the anterior tibial, 90% for the posterior tibial, and 82% for the peroneal. Clinical disease category did not influence in a major way the accuracy of lower extremity arterial duplex mapping in either above-knee or below-knee vessels.

Aged

The influence of elastic compression stockings on deep venous hemodynamics.

To determine the effect of elastic compression stockings on deep venous hemodynamics we measured ambulatory venous pressure, venous refill time, maximum venous pressure with exercise, amplitude of venous pressure excursion, and duplex-derived common femoral and popliteal vein diameter and peak flow velocities with and without stockings in 10 healthy subjects and 16 patients with chronic deep venous insufficiency. The effects of below-knee and above-knee 30 to 40 torr and 40 to 50 torr gradient stockings were studied. Despite documentation of substantial stocking compressive effects by skin pressure measurements, neither below-knee or above-knee elastic compression stockings significantly improved ambulatory venous pressure, venous refill time, maximum venous pressure with exercise, or the amplitude of venous pressure excursion in healthy patients or in patients with deep venous insufficiency (p greater than 0.05). In patients with deep venous insufficiency stockings modestly increased popliteal vein diameter and flow velocity in the upright resting position (p less than 0.02). After tiptoe exercise without stockings deep venous peak flow velocity increased in healthy patients and in patients with deep venous insufficiency by a mean of 103% in the popliteal vein and 46% in the common femoral vein (p less than 0.01). With the application of elastic compression stockings only modest augmentation of deep venous flow velocity occurred in both groups above that seen in the bare leg after exercise. Thus elastic compression stockings did not improve deep venous hemodynamic measurements in patients with deep venous insufficiency. The beneficial effects of stockings in the treatment of deep venous insufficiency must relate to effects other than changes in deep venous hemodynamics.

Adult

Duplex ultrasound criteria for diagnosis of splanchnic artery stenosis or occlusion.

Mesenteric artery duplex scanning appears promising for detection of splanchnic artery stenosis or occlusion or both in patients with symptoms suggestive of chronic intestinal ischemia. However, no specific duplex criteria have been developed for detection of mesenteric artery stenosis. We obtained mesenteric artery duplex scans and infradiaphragmatic lateral aortograms in 34 patients to determine duplex criteria for mesenteric stenosis. Seventy percent or greater angiographic stenosis was present in 10 superior mesenteric arteries and 16 celiac arteries. Duplex scans were reviewed to determine if celiac artery and superior mesenteric artery ratios of peak systolic velocities and end-diastolic velocities to peak aortic systolic velocity, as well as celiac artery and superior mesenteric artery peak systolic velocities and end-diastolic velocities alone, could predict a greater than or equal to 70% angiographic stenosis or occlusion or both. The results obtained by use of receiver operator curves indicated peak systolic velocity alone was an accurate predictor of splanchnic artery stenosis. Specifically, a peak systolic velocity greater than or equal to 275 cm/sec in the superior mesenteric artery and greater than or equal to 200 cm/sec in the celiac artery or no flow signal (superior mesenteric artery and celiac artery) predicted a 70% to 100% stenosis with sensitivity, specificity, and positive predictive values of 89%, 92%, and 80% for the superior mesenteric artery. Similar values for the celiac artery were 75%, 89%, and 85%, respectively. End-diastolic velocities or calculated velocity ratios conveyed no additional accuracy in predicting splanchnic artery stenosis.

Adult

Simultaneous operative repair of multilevel lower extremity occlusive disease.

Sixty-two patients (39 men (63%), 23 women (27%), mean age 68 years) with multilevel lower extremity arterial occlusive disease underwent simultaneous inflow and outflow operative arterial repair consisting of aortofemoral bypass in 22 (35%), axillofemoral bypass in 17 (28%), femorofemoral bypass in 15 (24%), iliac endarterectomy in 7 (11%), and unilateral aortoiliac bypass in 1 (2%), combined with 69 outflow procedures (unilateral in 55 patients, 89%), including above-knee femoropopliteal in 12 (17%), below-knee femoropopliteal in 35 (51%), femoroinfrapopliteal in 20 (29%), popliteal tibial in 1 (1%), and femoropedal bypass in 1 (1%). Multiple criteria were used to identify patients with multilevel disease likely to benefit from multilevel procedures. The operations were performed by two operating teams in a median time of 240 minutes. Prosthetic grafts were used for eight (13%) distal bypasses, the remainder were autogenous vein. There was one operative death (1.8%). The mortality rate, morbidity rate, and operative time were not significantly different from a group of patients who underwent concurrent, isolated inflow operations (aortofemoral, axillobifemoral, femorofemoral bypass or iliac endarterectomy). Mean follow-up was 14.9 months (range, 0 to 120). The life-table primary patency for the inflow procedures was 92.6% at 24 months, the outflow was 94.9% at 24 months. Cumulative limb salvage was 90.9% at 48-month follow-up. All patients with claudication were relieved of their symptoms. We conclude that complete correction of multilevel disease can be accomplished with operative time, morbidity rate, and patency equal to that of single level repair. Multilevel procedures provide complete relief of symptoms in a higher percentage of patients than has been reported after single level repair.

Adult

Fifteen-year results of ambulatory compression therapy for chronic venous ulcers.

A nonoperative approach to venous stasis ulceration of the lower extremity, consisting of initial bedrest, ulcer cleansing, dressing changes, and ambulatory elastic compression stocking therapy, has been maintained for over 15 years. All patients had class III, severe chronic venous insufficiency. One hundred five of 113 patients (93%) experienced complete ulcer healing in a mean of 5.3 months. One hundred two patients were compliant with elastic compression stockings, and 11 patients were noncompliant. Complete ulcer healing occurred in 99 of 102 patients (97%) who were compliant versus six of 11 patients (55%) who were noncompliant (p less than 0.0001). The influence of noncompliance, previous venous ulceration, previous venous surgery, previous known deep venous thrombosis, peripheral arterial insufficiency (ankle brachial systolic blood pressure index less than or equal to 0.60), pretreatment ulcer duration, ulcer size, age, sex, diabetes, smoking, and photoplethysmography venous refill time on ulcer healing was determined by logistic regression analysis. Only noncompliance with elastic compression stockings (p less than 0.0001) and a pretreatment ulcer duration of more than 9 months (p = 0.02) significantly decreased initial ulcer healing. Posthealing follow-up was available in 73 patients for a mean of 30 months. Fifty-eight patients (79%) continued to be compliant with stockings; 15 patients were noncompliant. Total ulcer recurrence in patients who were compliant was 16%. Five-year lifetable recurrence was 29%. All patients who were noncompliant had recurrent ulceration by 36 months. Previous ulceration, previous venous surgery, and peripheral arterial insufficiency had no effect on ulcer recurrence (p greater than 0.05).

Adult

Improving survival and limb salvage in patients with aortic graft infection.

A 15-year experience with 38 aortic graft infections, including 15 patients with graft enteric fistulas, is reviewed in order to analyze modern-day surgical results utilizing extra-anatomic bypass and aortic graft excision. Perioperative mortality was 14% during the most recent 7-year interval, which was a notable improvement compared with the earlier time interval (p = 0.06). Extended follow-up of the perioperative survivors demonstrated a 77% cumulative 5-year survival and a 76% cumulative 5-year limb salvage rate. Subsequent axillofemoral graft infection occurred in 22% of survivors and resulted in a significantly higher amputation rate compared with those patients with no axillofemoral graft infection (p less than 0.001). The results suggest good perioperative and long-term survival in patients with aortic graft infection, with excellent limb salvage if subsequent axillofemoral graft infection can be avoided.

Aged

Clinical results of axillobifemoral bypass using externally supported polytetrafluoroethylene.

Seventy-six axillobifemoral grafts with externally supported polytetrafluoroethylene prostheses were performed since 1983. The indications for operation were absolute (aortic sepsis) in 20 (26%) patients and relative (excessive operative risk or technical difficulty) in 56 (74%) patients. The life-table primary patency for these operations at 4 years follow-up (mean follow-up, 2 years, 4 months) was 85%. We conclude that the patency results achieved in this patient series are sufficiently satisfactory to warrant use of axillobifemoral grafts in an expanded number of patients with high operative risk and need for bypass of aortoiliac occlusive disease.

Aged

Can prosthetic graft infection be avoided? If not, how do we treat it?

Most arterial prosthetic graft infections can be prevented although a few will inevitably still occur. Maintaining a high index of suspicion for graft infection permits prompt diagnosis which provides the opportunity for early surgical management and improved potential for a good result. Aortic graft infection is best managed with extra-anatomical prosthetic bypass through clean tissue followed by graft excision. Results with this surgical approach are improving. Recently, authors advocating in situ grafting for graft enteric fistula as well as others recommending nonresectional therapy for localized prosthetic graft infections, have obtained encouraging results comparable to the best series of more standard excisional therapy. Because prosthetic graft infection remains a difficult surgical problem, any potentially useful management innovations warrant serious consideration and analysis with extended follow-up.

Anti-Bacterial Agents

The role of preoperative radionuclide ventriculography in defining outcome after revascularization of the extremity.

Revascularization of the extremity was performed upon 110 patients after preoperative radionuclide ventriculography (RNVG). Mean ejection fraction (EF) was 50 +/- 13 per cent. Ventricular wall motion abnormalities were present in 46 per cent. Revascularization included inflow procedures, such as aortofemoral (n = 25) or extraanatomic bypass (axillofemoral or femorofemoral, n = 11); infrainguinal reconstruction, including femoropopliteal or distal bypass (n = 43), and other procedures to improve perfusion of the limb or correct complications after previous vascular reconstruction upon the extremity (n = 31). Perioperative (30 days) mortality rate was 0.9 per cent and 97.0 per cent of the patients were discharged alive from the hospital. Myocardial infarction (MI) occurred in 3.6 per cent, new ventricular arrhythmia in 1.8 per cent and congestive heart failure in 6.4 per cent of the patients during the perioperative period. During follow-up study (607 +/- 363 days), 7.3 per cent required major amputation, ipsilateral to reconstruction, 5.5 per cent required surgical or angiographic revision for hemodynamic failure of the reconstruction prior to thrombosis and 12.7 per cent thrombosed part or all of the reconstruction. Revascularization failure did not appear to be related to the level of cardiac function. Those with normal (greater than 50 per cent) EF had greater over-all survival by life table analysis than those with EF less than or equal to 50 per cent (p = 0.0006, Mantel-Cox test). Ventricular wall motion abnormalities were associated with reduced over-all survival (p = 0.008, Mantel-Cox test). The presence of angina or previous MI, singularly or in combination, did not have an adverse effect on over-all survival, whereas diabetes (p = 0.0058, Mantel-Cox test) and cigarette smoking (p = 0.0137, Breslow test) were associated with significantly diminished over-all survival. Preoperative RNVG can identify subgroups at a survival disadvantage after revascularization of the extremity in a population in which the presence of angina or previous MI does not predict survival.

Adult

Analysis of risk factors for myocardial infarction following carotid endarterectomy.

A 4-year experience with 249 consecutive carotid endarter-ectomies performed on 224 patients is reviewed for incidence of perioperative (30-day) myocardial infarction and early survival (mean follow-up, 21 months). Except in cases of unstable angina, coronary arterial disease was evaluated only by routine history, physical examination, and electrocardiogram. By these criteria, 73% of patients had evidence of coronary arterial disease. Patients underwent carotid endarterectomy after appropriate medical management and stabilization of coronary disease symptoms (angina and/or congestive heart failure). One (0.4%) fatal and nine (3.6%) nonfatal perioperative myocardial infarctions Early survival of patients with active symptoms of coronary disease who did not undergo coronary bypass was similar to those patients with preceding or subsequent coronary bypass. The results of this review suggest routine clinical evaluation for coronary arterial disease is sufficient in the large majority of cases prior to carotid endarterectomy. Considering the reported high mortality of coronary bypass among vascular surgical patients, it appears that an aggressive program screening for cardiac surgical candidates either by coronary arteriography or radionuclide studies prior to carotid endarterectomy is not warranted.

Arteriosclerosis

Asymptomatic high-grade internal carotid artery stenosis: is stratification according to risk factors or duplex spectral analysis possible?

High-grade (80% to 99% diameter reduction) asymptomatic internal carotid artery stenoses are associated with an increased neurologic event rate (transient ischemic attack, stroke, asymptomatic internal carotid artery occlusion) compared to less severe asymptomatic lesions. However, many do remain free of associated events. To determine which are most dangerous, we compared risk factors and duplex scan results in two groups with asymptomatic high-grade internal carotid artery stenoses. Group A included 31 patients with 33 unoperated high-grade lesions that remained asymptomatic for at least 12 months (mean 30 months). Group B included 25 patients with 26 initially asymptomatic lesions that subsequently were associated with a neurologic event (mean time to event 7.4 months). The groups did not differ significantly in average age, sex, aspirin use, smoking, or prevalence of hypertension, diabetes, or cardiac disease. With respect to the index high-grade lesion, there was no difference in the frequency of a greater than 50% contralateral internal carotid artery stenosis or greater than 50% ipsilateral external carotid stenosis. However, on duplex scanning, high-grade stenoses with greater than 6.5 kHz end-diastolic frequencies were more frequently associated with an event than high-grade lesions with lower end-diastolic frequency (p = 0.0004). Similarly, seven of 23 lesions (30%) with end-diastolic frequency greater than 6.0 kHz were associated with subsequent internal carotid artery occlusion compared to only one of 29 (3.5%) with end-diastolic frequency less than or equal to 6.0 kHz (p = 0.025). Analysis of internal carotid artery end-diastolic frequency may help select a subgroup of patients with asymptomatic high-grade lesions who are at greatest risk for subsequent neurologic symptoms or ICA occlusion or both.

Aged