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Biomedical subjects

J W Olin

Publications and source records attributed to J W Olin.

At least 37 records · Page 2Linked to original sources
PubMed1998

Ischemic liver dysfunction after elective repair of infrarenal aortic aneurysm: incidence and outcome.

OBJECTIVE: To assess the frequency of early postoperative liver dysfunction in patients undergoing elective infrarenal aortic aneurysm repair, their hospital course, and outcome. DESIGN: A retrospective case-control study. SETTING: A single tertiary referral center. PARTICIPANTS: A review of medical records of 942 consecutive asymptomatic patients with normal preoperative liver function test results who had elective infrarenal aortic aneurysm repair with infrarenal aortic cross-clamping. The authors selected all patients who had an acute increase in serum hepatic enzyme levels (minimum fivefold increase in aspartate aminotransferase [AST] and twofold increase in lactate dehydrogenase [LDH] levels) within the first 7 perioperative days (study patients). The control group consisted of 42 patients with normal postoperative liver function test results, matched by age, sex, and year of surgery to study patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Aortic cross-clamping times, lowest intraoperative blood pressure, duration of hypotension (systolic blood pressure < or = 95 mmHg), lowest intraoperative base deficit, and estimated blood loss were compared between control and study patients. The study also analyzed perioperative metabolic, hemostatic, hepatic, and renal function variables; the intraoperative course; postoperative complications; and inhospital outcome. Fourteen of 942 patients (1.5%) comprised a study group. In 11 patients (1.2%), AST and LDH levels moderately increased, and three patients (0.3%) developed changes consistent with a diagnosis of acute ischemic hepatitis (AIH). In all patients, the serum liver enzyme levels peaked between 24 and 72 postoperative hours. Three patients with AIH developed concomitant acute renal failure; one had associated disseminated intravascular coagulation (DIC) and died. Of 11 patients with moderate increases, one subsequently developed multisystem organ failure and died. The overall in-hospital mortality rate for patients with postoperative liver dysfunction was 14% (2/14) and for the control group it was 2.3% (1/42). The duration of hypotension and metabolic acidosis were more pronounced in patients who postoperatively developed liver dysfunction (both p < 0.001); however, study and control patients did not differ in the duration of aortic cross-clamping, lowest intraoperative blood pressure, or estimated blood loss. CONCLUSION: Liver enzyme levels acutely increased in 1.5% of patients after elective infrarenal aortic aneurysm repair with infrarenal cross-clamping. In patients with moderately elevated serum liver enzyme levels, postoperative recovery was relatively uncomplicated, whereas all three patients with AIH developed acute renal failure and had a more complicated postoperative course. Those with postoperative liver dysfunction had a longer duration of intraoperative hypotension and more pronounced metabolic acidosis.

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PubMed1998

The natural history of asymptomatic moderate internal carotid artery stenosis by duplex ultrasound.

The purpose of this study was to determine the rate of progression of the degree of carotid stenosis and to determine the risk of continued observation in a group of asymptomatic patients with moderate stenosis of at least one internal carotid artery. Between 1989 and 1994, 2130 patients were found to have 60-79% stenosis of at least one internal carotid artery following a duplex ultrasound examination in the authors' vascular laboratory. Of these, 465 patients (255 men, 210 women) were asymptomatic and had more than one ultrasound examination, and they form the basis of this retrospective review. The mean +/- SD age was 68.8 +/- 9.0 years. The mean +/- SD number of ultrasound examinations was 3.1 +/- 1.4 (range 2-11). The mean +/- SD follow-up was 24.4 +/- 17.6 months (range 2-79 months). Over the period of follow-up 72 patients (15.5%) progressed to 80-99% stenosis (n = 71) or to occlusion (n = 1). The estimated percentage of patients who progressed by life table methods were 5 +/- 1% at 1 year, 11 +/- 2% at 2 years and 20 +/- 3% at 3 years. There was no statistically significant difference in the rate of progression in men compared with women. Twenty-one patients had a late ipsilateral TIA or stroke. Five out of 72 patients (6.9%) who progressed had a late ipsilateral TIA compared with nine out of 393 patients (2.3%) who did not progress (estimated risk ratio 16.1, P = 0.0001). Four out of 72 patients (5.6%) who progressed had a late ipsilateral stroke compared with three out of 393 patients (0.76%) who did not progress (estimated risk ratio 23.6, p = 0.0002). The cumulative ipsilateral stroke rate using life table methods was 0.22% at 1 year, 1% at 2 years and 2.4% at 3 years. In a large cohort of asymptomatic patients, the frequency of progression of 60-79% internal carotid artery stenosis was 5% at 1 year, 11% at 2 years and 20% at 3 years. Patients who progressed were more likely to have symptoms, but the rate of unheralded stroke was relatively low over a 3-year time period. Surveillance carotid ultrasound examinations should be performed in patients with moderate carotid stenosis. Because of the lack of clear benefit, carotid endarterectomy for asymptomatic 60-79% internal carotid artery stenosis cannot be justified.

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PubMed1998

Atherosclerotic stenosis of the renal arteries. Indications for intervention.

Advances in the ability to diagnose atherosclerotic stenosis of the renal arteries have increased awareness of this disorder over the past decade, and several medical specialties have become interested in its pathophysiology, diagnosis, and therapy. Improved surgical and anesthetic techniques and the development of endovascular technology have paved the way for more aggressive management of atherosclerotic renal artery stenosis. However, there is a lack of prospective data supporting this aggressive approach, and there is little agreement among physician groups concerning the appropriateness of revascularization in many patient scenarios. We will examine the available data and make recommendations about which patient groups might benefit most from renal artery revascularization (surgical or endovascular).

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PubMed1997

Carotid endarterectomy in adults 50 years of age and younger: a retrospective comparative study.

PURPOSE: Atherosclerotic carotid artery stenosis (CAS) is the most common cause of stroke in young adults. We retrospectively studied clinical characteristics of premature CAS and the safety and durability of carotid endarterectomy (CEA) in 56 patients 50 years of age or younger (mean, 46.4 years; 34 (60%) males; group I) who underwent primary CEA at the Cleveland Clinic between 1983 and 1993. METHODS: The patients were identified from the Vascular Surgery Registry and were compared with 202 randomly selected patients 60 years of age and older (mean, 69.3 years; group II) who were frequency-matched by gender and the year of primary CEA. Carotid shunting was used routinely, and the arteriotomy was patched in the majority of cases. Patients were followed-up for mean of 47.2 months (group I) and 46.0 months (group II). RESULTS: No significant differences were found in the indications for CEA (symptomatic CAS, 49% in group I vs 48% in group II) or the prevalence of diabetes, coronary diseases, and lower extremity arterial disease. Younger adults were more likely to have a history of smoking (93% vs 76%; p = 0.005), hypertension (71% vs 52%; p = 0.006), premature menopause (57% vs 18%; p < 0.001) and had lower levels of high-density lipoprotein cholesterol (p = 0.03). There were no in-hospital deaths. Perioperative strokes in the distribution of the operated artery occurred within 24 hours in one younger patient (1.8%) and in one older patient (0.5%). This was attributed to early carotid thrombosis in the young patient. Major late postoperative neurologic complications were documented in one young patient (1.8%) and six older patients (3%). Patients in group I were at significantly higher risk for recurrent carotid stenosis (risk ratio, 3.1; 95% confidence interval [CI], 1.3 to 7.3; p = 0.010); younger individuals remained at significantly higher risk for recurrent stenosis even after adjusting for smoking and hypertension (risk ratio, 3.7; 95% CI, 1.5 to 9.4; p = 0.006). By life-table analysis, younger adults tended to have a higher rate of late reoperations (p = 0.065). CONCLUSIONS: CEA can be safely performed in young adults with premature CAS, although younger individuals appear to have higher rates of recurrent carotid stenosis compared with older counterparts.

Adult↗
PubMed1997

Disseminated intravascular coagulation associated with acute ischemic hepatitis after elective aortic aneurysm repair: comparative analysis of 10 cases.

OBJECTIVE: To assess the characteristics of patients with perioperative disseminated intravascular coagulation (DIC) and acute ischemic hepatitis after elective aortic aneurysm repair (AAR). DESIGN: A retrospective case-control study. SETTING: A single tertiary referral center. PARTICIPANTS: Between 1982 and 1993, 1966 patients underwent elective AAR. Of these, 10 patients (eight with abdominal and two with thoracoabdominal aneurysms) developed DIC and acute elevation of serum transaminases consistent with acute ischemic hepatitis during or shortly after surgery. The control group included 30 patients matched by age, sex, year of surgery, and aneurysm type and size. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: None of the patients in either group had preoperative hemostatic abnormalities or other causes for DIC. There was no difference between the two groups in the duration of aortic cross-clamping. In all study patients, severe coagulopathy or systemic hypotension developed after the aortic cross-clamp was released. This resulted in significantly increased surgery time after unclamping (p < 0.001), and increased estimated blood loss (p < 0.001). DIC developed within 24 hours, and mean concentrations of aspartate transaminase (4,021 +/- 3,579 IU/L) and lactate dehydrogenase (4,332 +/- 2,903 IU/L) peaked on the second postoperative day. Nine (90%) of the study patients required repeat operations (seven for bleeding), and all of them died; the median survival time was 6 days (mean, 8.3 +/- 8.2 days). Only one patient in the control group needed a repeat operation. Liver infarction or necrosis was seen in all seven patients who underwent autopsy or biopsy. CONCLUSIONS: The combination of DIC and acute ischemic hepatitis ("hepatohemorrhagic syndrome") rarely occurs after elective AAR and is associated with a very high mortality rate. DIC was temporally related to the release of the aortic cross-clamp. The cause-effect relationship of this rare syndrome cannot be explained by operative course before the release of the aortic cross-clamp.

Acute Disease↗
PubMed1997

Thromboangiitis obliterans (Buerger's disease).

Thromboangiitis obliterans (TAO) is a nonatherosclerotic segmental inflammatory obliterative disease that most commonly affects the small- and medium-sized arteries and veins in both upper and lower extremities. In the past, TAO was exclusively a disease confined to men; however, recently more women have been diagnosed with TAO. Most patients are heavy users of tobacco, and usually cigarette smokers.

Adult↗
PubMed1997

High incidence of restenosis/reocclusion of stents in the percutaneous treatment of long-segment superficial femoral artery disease after suboptimal angioplasty.

PURPOSE: To evaluate the efficacy of intravascular stents used to treat long-segment stenoses and occlusions of the superficial femoral artery (SFA) after suboptimal angioplasty. METHODS: Fifty-eight limbs in 55 patients who underwent stenting of the SFA were identified from a vascular registry. Indications for stent placement after suboptimal PTA included flow-limiting dissection, residual pressure gradient (>15 mm Hg) or stenosis (>30%), or failure to establish initial patency. Lesion length ranged from 6 to 35 cm (mean, 16.5 cm). Endpoints for primary patency were: restenosis of >50%, reocclusion, or diminution of the postprocedure ankle-brachial index greater than 0.15. RESULTS: The mean ankle-brachial index improved from 0.48 +/- 0.19 to 0.71 +/- 0.23 (p = 0.001). Primary patency rates by Kaplan-Meier estimates at 1 month, 6 months, and 1 year were 88%, 47%, and 22%, respectively. Secondary patency rates were 94% at 1 month, 59% at 6 months, and 46% at 1 year. The median time to reaching an endpoint of restenosis or reocclusion was 6 months primarily and 9 months secondarily. Clinical improvement at the time of latest follow-up occurred in 56% of patients (mean, 13.8 months). Periprocedural complications occurred in 24.5% of patients with the first intervention. The only factor that favorably influenced outcome was improvement in clinical category after the procedure (p = 0.001). CONCLUSIONS: There was a high incidence of restenosis and reocclusion with long-segment SFA disease that required stents to achieve initial success. Despite close surveillance and reintervention, anatomic patency at 1 year was poor. However, clinical benefit was maintained in the majority of patients. The outcome was similar in the claudication population compared with those who had limb-threatening ischemia. Percutaneous revascularization of long-segment SFA disease requiring stents should be reserved for patients with critical limb ischemia for which no reasonable surgical alternative exists.

Adult↗
PubMed1997

Limitations of percutaneous transluminal angioplasty with stenting for femoropopliteal arterial occlusive disease.

PURPOSE: To review the results of intravascular stents used to treat superficial femoral artery (SFA) occlusive disease and to assist in patient selection for this procedure. METHODS AND RESULTS: We evaluated 55 patients who underwent balloon angioplasty and stenting of SFA long-segment disease and compared the results with those in the current literature. In our patient group, the SFA mean lesion length was 16.5 cm with the resting ankle-brachial index of 0.48 +/- 0.19. Hemodynamic improvement to an ABI of 0.71 +/- 0.23 (P = .001) and clinical benefit (56%) were maintained at 13.8 months. Primary and secondary patency rates were 22% and 46%, respectively, at 12 months. The literature reports patency rates of 29% to 81% primarily and 43% to 96% secondarily. However, the mean lesion length in these reports varied from 3.7 cm to 13.5 cm, and most of these patients had claudication (50% to 92%). Other variable factors determining long-term success may include the number and type of stent, artery occlusion versus stenoses, presence of diabetes mellitus, and smoking status. CONCLUSIONS: Stenting of short-segment SFA disease remains patent more frequently than for long-segment disease, and may be applicable in patients with disabling claudication or critical limb ischemia. Surgical revascularization is preferred for long-segment disease, with stenting reserved for patients with limb-threatening ischemia and no surgical alternative.

Angioplasty, Balloon↗
PubMed1997

Lower extremity arterial occlusions in young patients with Crohn's colitis and premature atherosclerosis: report of six cases.

Arterial occlusive disease (AOD) which is rarely described in patients with inflammatory bowel disease, is mainly associated with Crohn's disease (CD), and its etiology and natural course are unknown. We studied six patients (five women, one man) with CD and major lower extremity AOD who were treated at the Cleveland Clinic between 1985 and 1994. These were relatively young patients (age range 24-48 years) with steroid-dependent Crohn' colitis. On their presentation, five had acute onset of severe ischemic symptoms ("blue toe" syndrome in three) and one had rapid progression of claudication. All the patients had active CD and/or prior extensive bowel resections, and had no evidence of extraintestinal manifestation. Cardiovascular risk factors were smoking (n = 5), dyslipidemia (n = 3), family history of coronary artery disease (n = 3), premature menopause (n = 2), diabetes mellitus (n = 1). Arteriograms showed iliac artery involvement in all six patients and bilateral AOD in three. None of the patients had arteriographic or clinical signs of vasculitis. Five patients required arterial revascularizations, i.e., endovascular (n = 2), surgical (n = 2), and combined in one. Three patients had microscopic evidence of atherosclerosis. Lower extremity AOD in patients less than 50 yr of age and with CD may be partially related to premature atherosclerosis. Prospective screening for cardiovascular risk factors, subclinical disease, and hypercoagulability might be indicated in patients with active CD to prevent major arterial complications.

Adult↗
PubMed1996

Ultrasound-guided compression closure of postcatheterization pseudoaneurysms during concurrent anticoagulation: a review of seventy-seven patients.

PURPOSE: Data from our institution and elsewhere have demonstrated that ultrasound-guided compression closure (UGCC) is an effective method of treating postcatheterization pseudoaneurysms. Whereas patients receiving anticoagulation do not have as high a success rate as those not receiving anticoagulants, there have been no large series evaluating the factors associated with success or failure in patients receiving anticoagulation. The purpose of this study is to determine whether uninterrupted anticoagulation interferes with successful UGCC of pseudoaneurysms and to identify factors associated with success or failure. METHODS: From May 1991 to September 1994, 238 cases of attempted UGCC of pseudoaneurysms were performed in our vascular laboratory. Only patients who received uninterrupted heparin, warfarin, or both at the time of pseudoaneurysm compression were eligible for inclusion into the study. Seventy-seven patients were identified who met the study criteria. RESULTS: Successful pseudoaneurysm compression was obtained in 56 (73%) patients, whereas 21 (27%) patients had a failed UGCC. In the successfully treated group, seven (12.5%) required between two to three compression attempts to induce sustained thrombosis. There was no statistical difference in age, sex, sheath size, days after procedure, location of pseudoaneurysm, or number of chambers in the pseudoaneurysm between those patients who had a successful repair and those who did not. If the pseudoaneurysm was less than 4 cm in diameter, 51 of 65 patients (78%) had a successful repair compared with 5 of 12 patients (42%) with a pseudoaneurysm of 4 cm or greater (p = 0.013). There was no statistical difference between success and failure in patients receiving warfarin alone (3.73 mean international normalized ratio, 72% success rate), heparin alone (mean activated partial thromboplastin time of 63 seconds, 92% success rate), or heparin and warfarin (mean activated partial thromboplastin time of 70 seconds, mean international normalized ratio of 4, success rate of 67%). No arterial or venous thrombosis occurred during pseudoaneurysm compression. CONCLUSION: Successful UGCC of pseudoaneurysms occurred in a large percentage of patients receiving full-dose, uninterrupted anticoagulation. The only factor influencing success was the size of the pseudoaneurysm.

Adult↗
PubMed1996

Heparin administration via nomogram versus a standard approach in venous and arterial thromboembolic disease.

To determine whether heparin administered by continuous intravenous infusion using a nomogram is superior to a random dosing scheme, we performed a prospective, randomized comparative trial in 161 patients. Patients were prospectively randomized to one of three groups. Group I received an intravenous bolus of 5000 IU of heparin followed by heparin administration according to a modification of a previously published nomogram. Group II patients received a 5000 IU intravenous bolus of heparin followed by continuous intravenous heparin infusion with dosage adjustment at the discretion of the treating physician. Group III patients received a continuous intravenous heparin infusion with dosage adjustments at the discretion of the treating physician without the prior administration of a bolus dose. Activated partial thromboplastin time (APTT) was obtained at baseline, 6 h after each heparin dose adjustment and every morning. The mean percent of each patient's APTTs in the subtherapeutic range (< 50 sec) over the course of treatment was 9% for group I and 24% for groups II and III, p = 0.0001. The three groups had a similar percentage of each patient's APTTs within the therapeutic range (50-80 sec). There was a larger percentage of APTTs > 80 sec in group I (46%) compared to group II (31%) or group III (32%), p = 0.01. There were no clinically recurrent deep venous thrombi or arterial thromboemboli in any of the groups. Two patients had documented pulmonary emboli during heparin therapy (one in group I; one in group II). There was no difference in the complication rates of heparin therapy or the need for blood transfusions among the three groups. Patients randomized to the heparin nomogram (group I) achieved an APTT > 50 sec more frequently than patients in the other two groups. Overall, fewer patients in the nomogram group were subtherapeutic, and, when APTT levels fell in the subtherapeutic range, the nomogram restored APTTs to the therapeutic range faster than the standard methods. The heparin nomogram was clearly more effective as a method of heparin dosing than standard methods of anticoagulation dosing.

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PubMed1995

The utility of duplex ultrasound scanning of the renal arteries for diagnosing significant renal artery stenosis.

OBJECTIVE: To determine the utility of duplex ultrasound scanning of the renal arteries in identifying patients with renal artery stenosis of 60% or more and in excluding patients with either normal renal arteries or renal artery stenosis of less than 60%. DESIGN: A prospective, blinded study. SETTING: Large tertiary referral center. PATIENTS: 102 consecutive patients (44 men and 58 women with a mean age [+@- SD] of 63.3 +/- 13.4 years) who had both duplex ultrasound scanning of the renal arteries and renal arteriography. All patients who were studied had hypertension that was difficult to control, unexplained azotemia, or associated peripheral vascular disease (alone or in combination), giving them a high pretest likelihood of renovascular disease. MAIN OUTCOME MEASUREMENTS: Peak systolic and end diastolic velocities, renal-aortic ratios, resistive index, and kidney sizes. RESULTS: Sixty-two of 63 arteries with stenosis of less than 60% using arteriography were correctly identified by duplex ultrasound scanning. Thirty-one of 32 arteries with 60% to 79% stenosis using arteriography were correctly identified as having 60% to 99% stenosis on duplex ultrasound, whereas 67 of 69 arteries with 80% to 99% stenosis on arteriography were correctly identified as having 60% to 99% stenosis on ultrasound. Twenty-two of 23 arteries with total occlusion on arteriography were correctly identified by duplex ultrasound. The overall sensitivity of duplex ultrasound compared with arteriography was 0.98, the specificity was 0.98, the positive predictive value was 0.99, and the negative predictive value was 0.97. CONCLUSION: Duplex ultrasound scanning of the renal arteries is an ideal screening test because it is noninvasive and can predict the presence or absence of renal artery stenosis with a high degree of accuracy.

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