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Biomedical subjects

R A Yeager

Publications and source records attributed to R A Yeager.

At least 37 records · Page 2Linked to original sources

Reducing perioperative myocardial infarction following vascular surgery. The potential role of beta-blockade.

OBJECTIVE: To determine which perioperative variables may influence the occurrence of perioperative myocardial infarction (PMI) following vascular surgery. DESIGN: Case-control study. SETTING: Combined Veterans Affairs Medical Center-university hospital vascular service. PATIENTS: During a 4-year period, all major vascular surgical operations (N = 2088) were evaluated with serial postoperative electrocardiography and cardiac enzyme measurements. Patients with PMI following nonemergent vascular surgery (N = 53) were matched with randomly selected control patients without PMI (N = 106) for age, gender, type of operation, hypertension, and symptoms of coronary artery disease. MAIN OUTCOME MEASURES: The two groups were compared for operative blood loss, blood pressure, and heart rate as well as length of operation, type of anesthetic, and use of perioperative beta-blockers, nitroglycerine, calcium channel blockers, vasopressors, and angiotensin-converting enzyme inhibitors. RESULTS: beta-Blockers were used less frequently in patients with PMI than in control patients without PMI (30% vs 50%; P = .01). Overall beta-blockade was associated with a 50% reduction in PMI (P = .03). Perioperative myocardial infarction was not associated with length of operation, type of anesthetic, blood pressure, or use of other medications. CONCLUSIONS: beta-Blockade is associated with a decreased incidence of PMI in patients undergoing vascular surgery. Prophylactic perioperative use of beta-blockers may decrease PMI in patients requiring major vascular surgery. A prospective randomized trial of beta-blockers in these patients appears to be warranted.

Adrenergic beta-Antagonists↗

Upper extremity thromboembolism caused by occlusion of axillofemoral grafts.

BACKGROUND: The axillofemoral bypass graft (AxFG) is increasingly accepted as treatment for lower extremity ischemia caused by aortoiliac occlusive disease in high-risk patients. The incidence of upper extremity (UE) thromboembolism caused by occlusion of an AxFG and the results of treatment form the basis for this report. METHODS: From 1984 to the present, all patients undergoing axillofemoral bypass grafting were followed up in a vascular registry. A standardized operative technique, using an externally supported 8-mm polytetrafluoroethylene graft, was used in performing 202 AxFGs in 182 patients. UE thromboembolism caused by occlusion of an AxFG was identified by retrospective patient record review. RESULTS: Occlusion of an AxFG occurred in 20 patients. Fifteen patients (75%) underwent immediate revision of the occluded graft. Two patients (10%) developed UE thromboembolism simultaneous with graft occlusion. One of these patients had immediate revision of the graft, and 1 had brachial embolectomy only. This patient and 4 others (25%) had the occluded AxFG left in place. Four of these 5 patients (80%) developed UE thromboembolism at 26 days, 2 years, 5 years, and 7 years, respectively, after occlusion. Overall, six UE thromboembolic complications occurred in 5 patients. CONCLUSIONS: UE thromboembolism represents a significant and specific complication of occluded AxFGs in our series (2.7% of patients, 25% of occluded grafts). It may be prudent to prophylactically detach the axillary portion of the graft and repair the axillary artery in patients who do not require immediate revision of an occluded AxFG.

Algorithms↗

Do normal early color-flow duplex surveillance examination results of infrainguinal vein grafts preclude the need for late graft revision?

PURPOSE: Optimal duration of postoperative duplex surveillance of infrainguinal vein grafts is not known. Previous reports have suggested nearly all vein graft stenoses are present within the first postoperative year, and normal duplex examination results during this time eliminate the need for ongoing graft surveillance. To determine whether surveillance may be safely discontinued in patients with normal early postoperative surveillance studies, we reviewed the color-flow surveillance examinations in our patients who underwent infrainguinal reverse vein graft revisions during a 4 1/2 year period. METHODS: Clinical and vascular laboratory records were reviewed of all patients who underwent infrainguinal reverse vein bypass grafting followed by subsequent graft revision for a duplex scanning-detected abnormality at our institution between January 1990 and July 1994. RESULTS: Of 447 infrainguinal reverse vein bypasses performed, 36 (8.1%) underwent surgical revision as a result of an abnormal finding during routine duplex surveillance. The initial postoperative duplex examination was obtained within 2 weeks of graft implantation in 23 (64%) patients, between 2 weeks and 3 months in 10 (28%) patients, and between 3 and 6 months in three (8%) patients. Duplex abnormalities prompting revision included 11 (31%) grafts with a mid-graft peak systolic velocity (PSV) < or = 45 cm/sec, 23 (64%) grafts with a focal PSV > or = 200 cm/sec, one graft with a PSV > or = 150 cm/sec but < 200 cm/sec, and one thought to be occluded by duplex but found to be patent by angiography. Abnormal duplex findings were initially detected within 2 weeks of graft implantation in five (14%) patients, between 2 weeks and 3 months in eight (22%) patients, from 3 to 6 months in 12 (33%) patients, from 6 to 12 months in six (17%) patients, and > 1 year in five (14%) patients. In only 25% of cases were mid-graft PSVs < or = 45 cm/sec or focal velocities > or = 200 cm/sec identified on the initial examination; 75% were found during subsequent surveillance. CONCLUSIONS: Although most reverse vein graft abnormalities detected by duplex surveillance and prompting graft revision appear within the first postoperative year, many are not detected on the initial examination. In our recent experience 31% of duplex abnormalities leading to vein graft revision were first detected more than 6 months after operation. Discontinuation of graft surveillance based on normal early findings will result in thrombosis of some vein grafts that may otherwise be salvaged.

Adult↗

Deep vein thrombosis associated with lower extremity amputation.

PURPOSE: Patients undergoing lower extremity amputation are perceived to be at high risk for deep vein thrombosis (DVT). Limited data are available, however, to confirm this impression. The purpose of this study is to prospectively document the incidence of DVT complicating lower extremity amputation. METHODS: During a recent 28-month period, 72 patients (71 men, 1 woman; mean age 68 years) undergoing major lower extremity amputation (31 above-knee and 41 below-knee) were prospectively evaluated with perioperative duplex scanning for DVT. RESULTS: DVT was documented in nine (12.5%) patients (one bilateral, four ipsilateral, and four contralateral to amputation). Patients with a history of venous disease were at significantly higher risk for development of DVT (p = 0.02). Thrombi were located at or proximal to the popliteal vein in eight patients and were isolated to the tibial veins in one patient. DVT was identified before operation in six patients and after operation in three. Patients with DVT were treated with heparin anticoagulation, with no patient experiencing clinical symptoms compatible with pulmonary embolism. CONCLUSIONS: In our recent experience, lower extremity amputation is associated with DVT at or proximal to the popliteal vein in 11% of patients. Documentation of DVT prevalence is essential to assist surgeons in planning a management strategy for prevention, diagnosis, and treatment of DVT associated with lower extremity amputation.

Aged↗

Axillofemoral grafting with externally supported polytetrafluoroethylene.

OBJECTIVE: To evaluate the results of axillofemoral bypass grafting using externally supported polytetrafluoroethylene. DESIGN: Consecutive patients who were operated on by us from 1983 to the present were prospectively followed up in a vascular registry. The results of surgery with respect to morbidity and mortality, patency, limb salvage, and patient survival were determined by life-table methods. PATIENTS: A standardized operative technique was used to perform 184 axillofemoral bypass procedures in 164 consecutive patients (age range, 14 to 90 years; mean age, 67 years; female, 33%). Follow-up ranged from 0 to 95 months (mean, 23 months). RESULTS: Ischemia was the indication for 83% of the procedures, and aortic sepsis was the indication for 16%. There were nine operative deaths (5%) and 17 major complications. Life-table primary patency, limb salvage, and survival rates at 5 years were 71%, 92%, and 52%, respectively. Indication for surgery, patency of the superficial femoral artery, and the performance of multilevel procedures did not significantly influence patency. CONCLUSIONS: The results of axillofemoral grafting using polytetrafluoroethylene are equivalent to those achieved with other accepted methods of treatment for lower extremity ischemia, including balloon angioplasty, aortofemoral bypass, and infrainguinal bypass. Axillofemoral bypass is an appropriate technique that is deserving of more widespread use.

Adolescent↗

Acute disruption of polytetrafluoroethylene grafts adjacent to axillary anastomoses: a complication of axillofemoral grafting.

PURPOSE: Acute disruption at or adjacent to axillary anastomoses of axillofemoral grafts has been sporadically reported. We have recently reported the patency and limb salvage results of a large number of axillofemoral grafts. In this report we describe a series of axillary artery-graft disruptions that occurred in these patients. METHODS: Beginning in 1983, axillofemoral bypass was performed by the authors using standardized operative technique and a single prosthetic graft material (8 mm externally supported polytetrafluoroethylene). Axillary anastomoses were placed on the first portion of the artery and were performed with the arm abducted and with the graft redundant. The records and operative reports of all patients with disruption were reviewed for findings and subsequent hospital course. RESULTS: Two hundred two axillofemoral grafts were performed from 1983 to 1993. Ten patients (5%) had axillary disruption at intervals ranging from 1 to 46 days (mean 21 days) after operation. Ischemia was the indication for operation for seven of the patients and infected aortic prostheses for three. Infection did not occur in any of the axillary wounds and was not the cause of any of the disruptions. Four disruptions occurred with arm abduction/shoulder elevation movements; three awakened patients from sleep, and one occurred while the patient was sitting quietly. For the other two patients, preceding activity was unknown. Brachial plexus deficit was present in one patient. Four of the 10 disrupted grafts were also acutely occluded. Operative findings included sutures pulling out of the artery in four cases, tearing or sutures pulling out of the graft in four cases, and cause unknown in two cases. Treatment included arterial ligation in one patient, and restoration of circulation through revision of the axillofemoral grafts in the other nine patients. There were no operative deaths. One patient had a prolonged hospital course followed by nursing home placement and died 9 months later. The brachial plexus deficit did not resolve. There have been no repeat disruptions. CONCLUSIONS: We conclude that axillofemoral grafting includes the potential for disruption of the proximal anastomosis, which has occurred in 5% of our patients. Although multiple steps have been recommended to avoid this complication, occasional cases continue to occur despite observing all precautions.

Acute Disease↗

Surgical treatment of threatened reversed infrainguinal vein grafts.

PURPOSE: Current information concerning the results of surgical revision of threatened infrainguinal vein grafts is largely limited to in situ conduits. Infrainguinal grafts may be threatened by intrinsic graft lesions or significant stenosis in the adjacent inflow or outflow arteries. To assess the results of operative revision of infrainguinal reversed vein grafts, we reviewed our experience with surgical revision of threatened infrainguinal reversed vein grafts identified through a program of postoperative clinical and vascular laboratory graft surveillance. METHODS: All patients who underwent surgical revision of a threatened but patent infrainguinal reversed vein graft from January 1987 through April 1993 were identified through review of our vascular registry. Data were analyzed for type of vein used, date of original reversed vein graft, clinical and vascular laboratory findings leading to reversed vein graft revision, results of preoperative angiography, patient risk factors, operative techniques and complications, and long-term assisted primary graft patency and limb salvage. RESULTS: Ninety-six patients with 100 infrainguinal reversed vein grafts (69) femoral-popliteal, 31 femoral-tibial) underwent 117 surgical vein graft revisions or inflow procedures during the study period. Eighty-one percent of the original reversed vein grafts consisted of a single segment of greater saphenous vein. All revised grafts had at least a 50% stenosis in the graft itself or the proximal or distal artery. A single revision was performed in 85 grafts, two revisions in 13 grafts, and three revisions in two grafts. There were nine (8%) isolated inflow procedures, eight (7%) vein patch angioplasties, 62 (53%) interposition vein grafts, and 29 (25%) vein graft extensions to a new distal anastomotic site. The remaining nine (8%) procedures consisted of combinations of the above. Median time to primary graft revision after initial graft implantation was 15 months (range 2 days to 316 months). Mean time to secondary revision after primary revision was 21 months. Operative mortality was 0.9%. Cumulative assisted primary patency of the original grafts revised for stenotic lesions was 99%, 96%, and 92% at 1, 3, and 5 years, respectively. Limb salvage was 99%, 97%, and 97% at 1, 3, and 5 years, respectively. CONCLUSIONS: Although surgical revision of reversed vein graft requires much use of alternative vein sources, these procedures can be performed with minimum mortality and provide excellent assisted primary graft patency and limb salvage.

Adult↗

Late survival after perioperative myocardial infarction complicating vascular surgery.

PURPOSE: Although early death from perioperative myocardial infarction (PMI) after vascular surgery is well established, long-term outcome in patients surviving PMI is unknown. This prospective study was designed to determine cardiac outcome and survival rates in patients with symptomatic and asymptomatic nonfatal PMI associated with peripheral vascular surgery. METHODS: During a 36-month period for 1989 to 1992, all patients undergoing vascular surgery at our institution were monitored for PMI with serial creatine kinase and myocardial band isoenzymes and electrocardiography. PMIs were classified as symptomatic (associated with chest pain, arrhythmia, congestive heart failure, or hypotension) or asymptomatic (electrocardiographic changes and/or elevated creatine kinase and myocardial band isoenzymes). Patients with PMI were then prospectively monitored and compared for late survival, with control patients undergoing vascular surgery without PMI during the same interval. RESULTS: During the study period 1561 major peripheral vascular procedures were performed. There were 47 PMIs (3.0%). Eleven (0.7%) PMIs were fatal, 31 were nonfatal, and five other patients with PMI died during operation of non-heart-related causes. Eight of 31 patients with nonfatal PMI had a "chemical PMI" with creatine kinase and myocardial band isoenzyme elevation as the sole indicator of PMI. During follow-up (mean 27.7 months), there was a higher incidence of both subsequent myocardial infarction and coronary artery revascularization among the patients with nonfatal PMI compared with control subjects (p < 0.05); however, survival for patients with nonfatal PMI at 1 and 4 years (80% and 51%) did not differ from that of control patients (90% and 60%) (p > 0.05). Patients with "chemical PMI" had similar patterns of subsequent myocardial infarction and coronary intervention as control patients. CONCLUSIONS: Patients surviving nonfatal PMI after peripheral vascular surgery have a higher incidence of subsequent adverse cardiac events and coronary artery revascularization than patients undergoing vascular surgery without PMI, but they have similar survival rates at 1 and 4 years. Patients in the enzyme-only PMI group have a similar outcome compared with control subjects suggesting that a perioperative "chemical MI" may not be a significant clinical event.

Aged↗

Repeat leg bypass after multiple prior bypass failures.

PURPOSE: The optimal treatment of patients with severe lower extremity ischemia after multiple failed prior bypasses is unclear. It is presently unknown whether failure of attempted revascularization in these patients is so likely that such operation should not be elected. We have maintained an aggressive surgical policy of repeated revascularization regardless of prior failures. A review of our clinical experience with this difficult patient group was performed to determine the results of this policy. METHODS: From 1980 to 1992, 85 revascularization procedures were performed in 81 patients with lower extremity ischemia after failure of two or more prior infrainguinal bypasses in the same leg. All patients were prospectively entered and monitored in our vascular registry. Seventy-two operations were the third procedure, six operations were the fourth procedure, and seven operations were the fifth procedure on the same extremity. Twenty-six of the 85 procedures (30%) were revisions of failing grafts discovered by routine surveillance methods, whereas 59 were replacements of thrombosed grafts. Autogenous reconstruction was used in 67 procedures (79%), and prosthetic reconstruction was used in 18 procedures (21%). The distal anastomosis was to the popliteal artery in 19 patients and infrapopliteal artery in 66. RESULTS: Mean time to failure of the first leg bypass was 24 months and 4.9 months for the second bypass. Detailed hematologic screening revealed identifiable hypercoagulable disorders in nine (15%) of 59 patients screened after 1987. All nine had anticardiolipin antibodies. The operative mortality rate was 4%. Mean follow-up after the most recent operation was 17 months. The primary patency rate at 4 years was 79.8%. The limb salvage rate was 69.6% at 4 years. CONCLUSIONS: These results indicate that limb revascularization after two or more failed leg bypasses results in low operative mortality rates and surprisingly good primary patency and limb salvage rates at 4 years. The patient survival rate through 4 years is unexpectedly high. In our opinion these results justify an aggressive policy of limb vascularization after multiple failed prior bypasses.

Adult↗

Hemodynamic assessment of combined aortoiliac/femoropopliteal occlusive disease and selection of single or multilevel revascularization.

Approximately 25% of patients with multilevel arterial occlusive disease will require both inflow and outflow revascularization in order to successfully resolve their symptoms of lower limb ischemia. The preoperative selection of patients for multilevel concurrent arterial reconstruction is guided by symptoms, information from the noninvasive vascular laboratory, the predicted postoperative ABI, and detailed multiview angiography including pull-back intra-arterial pressure measurements. Properly selected patients will benefit from a carefully planned and expeditiously performed simultaneous revascularization. Current results indicate no significant increase in operative morbidity or mortality rates and excellent graft patency rates with these combined procedures.

Aortic Diseases↗

Anticoagulation followed by elective carotid surgery in patients with repetitive transient ischemic attacks and high-grade carotid stenosis.

OBJECTIVE: To evaluate the results of preoperative heparin therapy followed by carotid surgery for patients with repetitive transient ischemic attacks (TIAs) and high-grade carotid stenoses. DESIGN: A 4-year prospective study. SETTING: Oregon Health Science University Hospital and Portland (Ore) Veterans Affairs Hospital. PATIENTS: Twenty-nine consecutive patients with repetitive TIAs referable to 30 high-grade (> or = 70%) ipsilateral carotid stenoses were treated with short-term heparin anticoagulation, followed by cerebral angiography, routine preoperative evaluation, and subsequent carotid reconstruction. INTERVENTIONS: Heparin sodium anticoagulation was maintained for a mean of 5 days. Surgical management consisted of 24 standard endarterectomies, five bypasses to the internal carotid artery, and one external carotid endarterectomy. MAIN OUTCOME MEASURES: Primary outcome variables included perioperative hemorrhage, thrombocytopenia, stroke, and death. Secondary outcome variables included carotid occlusion and recurrent TIAs with heparin therapy. RESULTS: One symptomatic common carotid occlusion and one asymptomatic internal carotid occlusion occurred during preoperative heparin therapy. Thirteen patients had additional sporadic TIAs while receiving heparin. There were no preoperative cerebral infarcts, thrombocytopenia, or clinical bleeding associated with heparin therapy. There was one postoperative stroke and one death due to myocardial infarction. CONCLUSION: When necessary, heparin anticoagulation and delayed carotid reconstruction would appear to be an acceptable alternative to emergency carotid surgery in patients with high-grade carotid stenosis and acute repetitive TIAs.

Aged↗

Noninvasive localization of arterial occlusive disease: a comparison of segmental Doppler pressures and arterial duplex mapping.

PURPOSE: The purpose of this study was to compare the abilities of arterial duplex mapping and segmental Doppler pressures to noninvasively localize hemodynamically significant lower extremity arterial occlusive disease. METHODS: After angiographic controls were instituted, arterial duplex mapping and segmental Doppler pressures were blindly compared for their ability to localize a high-grade (50% to 100%) stenosis to the iliac or common femoral arteries, the superficial femoral artery, or the popliteal artery in 151 lower extremities from 79 patients. RESULTS: Rates of sensitivity and specificity of arterial duplex mapping for identifying a high-grade stenosis at the three arterial levels were 88% and 97%, 95% and 100%, and 78% and 99%, respectively. Those for segmental Doppler pressures were 59% and 86%, 73% and 80%, and 48% and 53%, respectively. There was complete agreement between arterial duplex mapping and angiography in 82% of the limbs studied and between segmental pressures and angiography in 34% of the limbs (p < 0.0001). The presence of diabetes, kidney failure, or previous vascular surgery in the limb studied did not affect the accuracy of either test. CONCLUSION: Arterial duplex mapping is far superior to segmental Doppler pressures for localization of high-grade angiographic lesions from the iliac to the popliteal arteries.

Aged↗

Mesenteric duplex scanning: a blinded prospective study.

PURPOSE: Based on retrospective comparisons of duplex scanning with arteriography of the celiac (CA) and superior mesenteric (SMA) arteries in 34 patients, we previously suggested that an SMA peak systolic velocity of 275 cm/sec or greater or no flow signal and a CA PSV of 200 cm/sec or greater or no flow signal were reliable indicators of a 70% or greater angiographic stenosis of the SMA and CA, respectively. We now report the results of a blinded, prospective study in a larger patient group designed to determine the ability of mesenteric duplex scanning to visualize the CA and SMA and to validate our proposed duplex criteria for splanchnic artery stenosis. METHODS: During an 18-month period 100 patients admitted to our vascular surgery service for aortography underwent routine mesenteric artery duplex scanning and lateral abdominal aortography regardless of abdominal symptoms. The lateral aortograms were evaluated to determine the presence or absence of a 70% or greater stenosis in the CA or SMA. Duplex-determined peak systolic velocities from the CA and SMA were recorded without knowledge of the angiographic results. RESULTS: Aortography satisfactorily visualized 100% of the CAs and 99% of the SMAs. Of these, 93% of the SMAs and 83% of the CAs were visualized by duplex. According to the above criteria, duplex sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for detection of a 70% or greater SMA stenosis were 92%, 96%, 80%, 99%, and 96% and for a 70% or greater CA stenosis 87%, 80%, 63%, 94%, and 82%. CONCLUSIONS: Mesenteric duplex scanning is feasible in the majority of patients. Prospective evaluation of duplex diagnostic criteria for 70% or greater stenosis indicates that mesenteric duplex scanning is sufficiently accurate to be clinically useful as a screening examination to detect SMA and CA stenosis.

Adult↗

Nonatherosclerotic claudication.

Lower extremity claudication typically reflects the presence of significant atherosclerotic arterial obstructive disease. However, a group of nonatherosclerotic conditions may cause similar symptoms and a keen appreciation of these unusual conditions is essential for the fully trained vascular surgeon. Typical atherosclerotic risk factors may or may not be present among patients with nonatherosclerotic claudication. However, the astute vascular surgeon can diagnose these nonatherosclerotic conditions with a carefully focused history and physical examination followed by optimally selected noninvasive testing and imaging studies. Once accurately diagnosed, effective and durable treatments are generally available for this heterogeneous group of patients.

Arteriosclerosis↗

Surgery for chronic lower extremity ischemia in patients eighty or more years of age: operative results and assessment of postoperative independence.

PURPOSE: Revascularization for chronic lower extremity ischemia (CLEI) in patients 80 or more years of age is controversial. High operative mortality, short remaining life span, and nonambulatory nursing home existence are cited as frequent outcomes in this patient group. Despite these considerations we have maintained an aggressive policy of lower extremity revascularization in functional and potentially functional patients 80 or more years of age with limb-threatening ischemia or claudication sufficient to threaten their independence. METHODS: The records of all patients 80 or more years of age who underwent lower extremity revascularization for CLEI from 1981 through 1991 were reviewed. Patients were evaluated for surgical indication, perioperative mortality, late survival, graft patency, and limb salvage. In addition, the patient's preoperative and postoperative independence determined by living situation (home versus nursing home) and ambulatory status were examined. RESULTS: During the period reviewed 88 patients 80 or more years of age underwent 95 arterial reconstructions for CLEI; 95% for limb salvage and 5% for short-distance claudication. There were 81 (85%) infrainguinal bypasses and 14 (15%) extra-anatomic bypasses, 5 of which also included a simultaneously placed infrainguinal bypass. The perioperative mortality rate was 6%. Mean hospitalization was 18 days (range 6 to 62). The 1- and 3-year primary graft patency rates were 88% and 66%, limb salvage rates 94% and 91%, and patient survival rates 73% and 51%, respectively. One year after operation 88% of patients were ambulatory, 85% were living at home, and 80% were both living at home and ambulatory. At 3 years these results were 86%, 76%, and 71%, respectively. Of the patients living at home and ambulatory before operation, 100% and 84% of survivors were still living at home and ambulatory 1 and 3 years after operation. Of patients living at home who had late graft occlusions, 67% required amputation and subsequent nursing home placement. CONCLUSION: Although survival in this group is predictably lower than that of age-matched control subjects, octogenarians have satisfactory 1- and 3-year graft patency, limb salvage, and functional results. Revascularization for CLEI in patients 80 or more years of age is appropriate and results in maintenance of independent living in a large majority.

Activities of Daily Living↗

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↗