J C Stanley

Publications (172)515.03 Total impact

• Article: Renal artery aneurysms: diagnosis, management and outcomes.

  P K Henke, J C Stanley
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  ABSTRACT: Renal artery aneurysms are an uncommon vascular entity and are more likely to affect younger patients without significant atherosclerotic risk factors as compared to patients with renal artery occlusive disease. Hypertension is a commonly associated disease and the renal artery aneurysm may be causal, exclusive of renal artery occlusive disease. Diagnosis is often made incidentally but arteriography is essential for good operative planning. The main complication of RAA is rupture, which is increased in peripartum females. Operative therapy is primarily in situ aneurysmectomy and angioplastic closure or exclusion and bypass, usually with autologous conduit. It is currently recommended that in good operative risk patients, repair is recommended for RAA >1.0 cm when hypertension present and RAA >1.5 to 2.0 cm when no hypertension present. Given the anatomic complexity of these lesions, little role for endovascular therapy is forecast.
  Minerva chirurgica 06/2003; 58(3):305-11. · 0.77 Impact Factor
• Article: Computed tomographic venography is specific but not sensitive for diagnosis of acute lower-extremity deep venous thrombosis in patients with suspected pulmonary embolus.

  D A Peterson, E A Kazerooni, T W Wakefield, B S Knipp, A R Forauer, B J Bailey, V V Sullivan, M C Proctor, P K Henke, L J Greenfield, J C Stanley, G R Upchurch
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  ABSTRACT: Duplex ultrasound scanning (US) is the accepted standard means of diagnosis for lower-extremity suprageniculate deep venous thrombosis (LE-DVT). Computed tomographic venography (CTV) has been proposed as an alternative modality for diagnosis of LE-DVT in patients with suspected pulmonary embolism (PE). This study compared CTV with US as a means of diagnosing acute LE-DVT. A retrospective review of US and CTV scans from 136 patients with suspected PE who underwent both studies to exclude acute LE-DVT at a single institution was performed. Studies were reviewed and coded in a blinded manner. US was considered to be the reference test. Direct costs of each study were determined by using commercial software. The sensitivity and specificity rates of CTV were 71% and 93%, respectively. The positive predictive value, negative predictive value, and accuracy rates of CTV were 53%, 97%, and 90%, respectively. DVT localization was the same in eight of 10 cases in which the results of both US and CTV were positive. CTV costs and charges per study were greater than those of US by $46.88 and $602.00, respectively. CTV is specific, but has a lower sensitivity rate and positive predictive value for the diagnosis of acute LE-DVT compared with US. Additionally, CTV is more costly than US scanning. Because of the lower sensitivity rate and positive predictive value and the increased cost of CTV, US remains the screening study of choice in cases of suspected acute LE-DVT.
  Journal of Vascular Surgery 12/2001; 34(5):798-804. · 3.21 Impact Factor
• Article: Renal artery aneurysms: a 35-year clinical experience with 252 aneurysms in 168 patients.

  P K Henke, J D Cardneau, T H Welling, G R Upchurch, T W Wakefield, L A Jacobs, S B Proctor, L J Greenfield, J C Stanley
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  ABSTRACT: To define the relevance of treating renal artery aneurysms (RAAs) surgically. Most prior definitions of the clinical, pathologic, and management features of RAAs have evolved from anecdotal reports. Controversy surrounding this clinical entity continues. A retrospective review was undertaken of 168 patients (107 women, 61 men) with 252 RAAs encountered over 35 years at the University of Michigan Hospital. Aneurysms were solitary in 115 patients and multiple in 53 patients. Bilateral RAAs occurred in 32 patients. Associated diseases included hypertension (73%), renal artery fibrodysplasia (34%), systemic atherosclerosis (25%), and extrarenal aneurysms (6.5%). Most RAAs were saccular (79%) and noncalcified (63%). The main renal artery bifurcation was the most common site of aneurysms (60%). RAAs were often asymptomatic (55%), with a diagnosis made most often during arteriographic study for suspected renovascular hypertension (42%). Surgery was performed in 121 patients (average RAA size 1.5 cm), including 14 patients undergoing unilateral repair with contralateral RAA observation. The remaining 47 patients (average RAA size 1.3 cm) were not treated surgically. Operations included aneurysmectomy and angioplastic renal artery closure or segmental renal artery reimplantation, aneurysmectomy and renal artery bypass, and planned nephrectomy for unreconstructable renal arteries or advanced parenchymal disease. Eight patients underwent unplanned nephrectomy, being considered a technical failure of surgical therapy. Dialysis-dependent renal failure occurred in one patient. There were no perioperative deaths. Late follow-up (average 91 months) was available in 145 patients (86%). All but two arterial reconstructions remained clinically patent. Secondary renal artery procedures included percutaneous angioplasty, branch embolization, graft thrombectomy, and repeat bypass for late aneurysmal change of a vein conduit. Among 40 patients with clearly documented preoperative and postoperative blood pressure measurements, 60% had a significant decline in blood pressure after surgery while taking fewer antihypertensive medications. Late RAA rupture did not occur in the nonoperative patients, but no lessening of this group's hypertension was noted. Surgical therapy of RAAs in properly selected patients provides excellent long-term clinical outcomes and is often associated with decreased blood pressure.
  Annals of Surgery 11/2001; 234(4):454-62; discussion 462-3. · 7.49 Impact Factor
• Article: Interobserver variability in the evaluation of chronic mesenteric ischemia with gadolinium-enhanced MR angiography.

  R C Carlos, J C Stanley, D Stafford-Johnson, M R Prince
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  ABSTRACT: The purpose of this study was to assess interobserver variability in the interpretation of gadolinium-enhanced magnetic resonance (MR) angiograms of splanchnic vessels in patients suspected of having chronic mesenteric ischemia (CMI). Two readers blinded to the initial interpretation retrospectively reviewed gadolinium-enhanced MR angiograms obtained for suspected CMI in 26 patients (20 women and six men; age range, 23-77 years; mean age, 61 years) who also underwent conventional angiography. Each reader graded the degree of stenosis based on the percentage diameter reduction of the celiac artery (CA), superior mesenteric artery (SMA), and inferior mesenteric artery (IMA) by using a five-point ordinal scale: 0, no stenosis: 1, mild stenosis (<50%); 2, moderate stenosis (50%-75%); 3, severe stenosis (>75%); 4, occluded artery. Using the conventional angiogram as a reference standard, authors determined sensitivity and specificity for each observer, assigning two thresholds (grades 2 and 3) as significant stenoses. A kappa statistic (kappa) measured interobserver agreement. With grade 2 stenosis used as a threshold, cumulative accuracies for detecting significant stenosis were 0.95 (95% confidence interval, 0.86-0.99) for reader A and 0.97 (0.88-1.0) for reader B. Interobserver agreement for grading proximal splanchnic stenosis was 0.90 for CA, 0.92 for SMA, and 0.48 for IMA. Gadolinium-enhanced MR angiography is reproducibly accurate for detection of proximal splanchnic artery stenosis, with good to excellent interobserver agreement.
  Academic Radiology 10/2001; 8(9):879-87. · 1.69 Impact Factor
• Article: Efficacy and durability of autogenous saphenous vein conduits for lower extremity arterial reconstructions in preadolescent children.

  J D Cardneau, P K Henke, G R Upchurch, T W Wakefield, L M Graham, L A Jacobs, L J Greenfield, A G Coran, J C Stanley
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  ABSTRACT: Limb length discrepancies (LLDs) in growing children may accompany extremity arterial occlusions. Revascularization with vein grafts has been questioned because of degenerative graft changes observed at other sites. This study was undertaken to define vein graft durability and efficacy in lower extremity revascularizations in preadolescent children. Study Design: Fourteen children (10 boys, 4 girls) with a mean age of 7.3 years (range, 2-11 years) who underwent 16 lower extremity revascularizations with greater saphenous vein grafts were subjected to follow-up with graft ultrasonography, ankle/brachial indices (ABIs) with and without exercise, and limb length determinations. A mean of 5.7 years elapsed between the onset of ischemia and operation. Arterial occlusions resulted from cardiac catheterizations (11), arteritis (1), dialysis cannulation (1), and penetrating trauma (1). Indications for operation included LLD (6), claudication (4), both LLD and claudication (3), markedly diminished ABIs with a potential for LLD (2), and a traumatic transection with hemorrhage (1). The reconstructions with 15 reversed and one in situ vein grafts included iliofemoral (11), femorofemoral (1), aortofemoral (1), femoropopliteal (1), popliteal-popliteal (1), and popliteal-posterior tibial (1) arterial bypass grafts. Among patent grafts available for follow-up, 36% (5 of 14) remained unchanged, 50% (7 of 14) developed nonaneurysmal dilatation, and 14% (2 of 14) exhibited nonprogressive aneurysmal expansion. One graft became occluded, and one graft was lost to follow-up. Collectively, the grafts manifest an 11.2% expansion at an average of 10.7 years postoperatively. ABIs increased from 0.75 preoperatively to 0.97, at an average of 11.0 years postoperatively. LLDs were reduced from 1.66 to 1.24 cm, at an average of 11.4 years postoperatively. Vein graft reconstructions of lower extremity arteries in preadolescent children are durable. They provide an efficacious means of restoring normal blood flow, and in 70% of children their preexisting LLDs were reduced.
  Journal of Vascular Surgery 08/2001; 34(1):34-40. · 3.21 Impact Factor
• Article: Nitric oxide inhibition increases matrix metalloproteinase-9 expression by rat aortic smooth muscle cells in vitro.

  G R Upchurch, J W Ford, S J Weiss, B S Knipp, D A Peterson, R W Thompson, M J Eagleton, A J Broady, M C Proctor, J C Stanley
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  ABSTRACT: The hypothesis to be tested was that diminished bioavailable nitric oxide (NO) affects matrix metalloproteinase (MMP) expression and activation in vascular smooth muscle cells (SMCs). Cultivated rat aortic SMCs (RA-SMCs) were exposed to increasing concentrations of L-N-monomethyl arginine (L-NMMA), a nonselective inhibitor of NO synthase, in the presence of proinflammatory cytokines (50 ng/mL interleukin [IL]-1beta, 50 ng/mL interferon-gamma, and 30 microg/mL lipopolysaccharide). Nitrite and nitrate, two of the final end products of NO metabolism, were measured in media collected at 48 hours with the use of the Saville assay (n = 4). MMP activity was measured with 1% gelatin zymography (n = 4). In separate experiments in which 2 ng/mL of IL-1beta and L-NMMA was used, MMP protein and messenger RNA (mRNA) levels were determined with Western blot analysis (n = 3) and semiquantitative reverse transcriptase-polymerase chain reaction (n = 3), respectively. Data were analyzed with nonparametric analysis of variance. Increasing concentrations of the NO synthase inhibitor L-NMMA caused a dose-dependent decrease (P <.05) in nitrite and nitrate production by RA-SMCs after cytokine exposure. Zymography documented an early dosedependent increase (P <.05 compared with cytokines alone) in 92-kd MMP activity, with no significant changes in 72-kd MMP activity after treatment with L-NMMA (P >.05 compared with cytokines alone). Reverse transcriptase-polymerase chain reaction and Western blot analysis revealed that the addition of L-NMMA to IL-1beta-stimulated RA-SMCs led to significant increases in MMP-9 mRNA (n = 3, P <.01 for 1.0 mmol/L L-NMMA) and MMP-9 protein levels (n = 3, P <.05), respectively. No differences in MMP-2 mRNA or protein levels were demonstrated. Inhibition of cytokine-induced NO expression in RA-SMCs is associated with a selective, dose-dependent increase in MMP-9 expression and synthesis. These findings suggest that alterations in local NO synthesis may influence MMP-9-dependent vessel wall damage.
  Journal of Vascular Surgery 07/2001; 34(1):76-83. · 3.21 Impact Factor
• Article: Impact of chronic obstructive pulmonary disease on elective and emergency abdominal aortic aneurysm repair.

  D A Axelrod, P K Henke, T W Wakefield, J C Stanley, L A Jacobs, L M Graham, L J Greenfield, G R Upchurch
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  ABSTRACT: Chronic obstructive pulmonary disease (COPD) is associated with abdominal aortic aneurysm (AAA) expansion and is considered by some to be a relative contraindication to conventional aortic surgery. This study was undertaken to determine if COPD increases operative death, morbidity, intensive care unit (ICU) length of stay (LOS), and hospital LOS, after AAA repair. Data from national administrative records supplemented with laboratory data previously obtained for a system-wide study were analyzed in a retrospective review of 1053 consecutive patients (264 with and 789 without COPD) undergoing operation for intact or ruptured AAAs in Veterans Administration Hospitals from 1997 to 1998. Bivariate comparisons and multivariate regression were used to evaluate the impact of COPD on the number of days of ventilation, ICU LOS, total hospital LOS, and death, while controlling for other known risk factors, including acute myocardial infarction, renal failure, and age. The mortality rate in elective aneurysm patients did not differ (P =.99) between patients with (3.7%) or without COPD (3.7%). However, elective AAA repair was associated with longer hospital LOS (14.4 vs 12.3 days, P =.01), longer ICU LOS (6.5 vs 5.4 days, P =.01), and a higher incidence of requiring 96 hours or more ventilation (6.9% vs 3.6%, P =.02) in patients with COPD. Ruptured AAA affected 4.9% of patients and was strongly associated with COPD (P =.02); however, COPD did not result in a statistically significant increase in death (P =.25). Although COPD does not appear to increase operative death, it is associated with an increased risk of rupture. Elective repair of AAA should not be deferred in patients with COPD despite their higher LOSs and need for postoperative ventilation.
  Journal of Vascular Surgery 02/2001; 33(1):72-6. · 3.21 Impact Factor
• Article: Evaluation of a cerebral oximeter as a monitor of cerebral ischemia during carotid endarterectomy.

  S K Samra, E A Dy, K Welch, P Dorje, G B Zelenock, J C Stanley
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  ABSTRACT: Stroke is an important contributor to perioperative morbidity and mortality associated with carotid endarterectomy (CEA). This investigation was designed to compare the performance of the INVOS-3100 cerebral oximeter to neurologic function, as a means of detecting cerebral ischemia induced by carotid cross-clamping, in patients undergoing carotid endarterectomy with cervical plexus block. Ninety-nine patients undergoing 100 CEAs with regional anesthesia (deep or superficial cervical plexus block) were studied. Bilateral regional cerebrovascular oxygen saturation (rSO2) was monitored using the INVOS-3100 cerebral oximeter. Patients were retrospectively assigned to one of two groups: those in whom a change in mental status or contralateral motor deficit was noted after internal carotid clamping (neurologic symptoms; n = 10) and those who did not show any neurologic change (no neurologic symptoms; n = 90). Data from 94 operations (neurologic symptoms = 10 and no neurologic symptoms = 84) were adequate for statistical analyses for group comparisons. A relative decrease in ipsilateral rSO2 after carotid occlusion (calculated as a percentage of preocclusion value) during all operations (n = 100) was also calculated to determine the critical level of rSO2 decrease associated with a change in neurologic function. The mean (+/- SD) decrease in rSO2 after carotid occlusion in the neurologic symptoms group (from 63.2 +/- 8.4% to 51.0 +/- 11.6%) was significantly greater (P = 0.0002) than in the no neurologic symptoms group (from 65.8 +/- 8.5% to 61.0 +/- 9.3%). Logistic regression analysis used to determine if a change in rSO2, calculated as a percentage of preclamp value, could be used to predict change in neurologic function was highly significant (likelihood ratio chi-square = 13.7; P = 0.0002). A 20% decrease in rSO2 reading from the preclamp baseline, as a predictor of neurologic compromise, resulted in a sensitivity of 80% and specificity of 82.2%. The false-positive rate using this cutoff point was 66.7%, and the false-negative rate was 2.6%, providing a positive predictive value of 33.3% and a negative predictive value of 97.4%. Monitoring rSO2 with INVOS-3100 to detect cerebral ischemia during CEA has a high negative predictive value, but the positive predictive value is low.
  Anesthesiology 11/2000; 93(4):964-70. · 5.36 Impact Factor
• Article: The discipline of vascular surgery at the close of the millennium, the American Board of Surgery Sub-Board for Vascular Surgery, and the wisdom of evolving a conjoint board of vascular surgery: one surgeon's perspective.

  J C Stanley
  Journal of Vascular Surgery 05/2000; 31(4):831-5. · 3.21 Impact Factor
• Article: Incidence of femoral and popliteal artery aneurysms in patients with abdominal aortic aneurysms.

  A Diwan, R Sarkar, J C Stanley, G B Zelenock, T W Wakefield
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  ABSTRACT: The purpose of this study was to determine the incidence of femoral and popliteal aneurysms in men and women who have abdominal aortic aneurysms (AAAs) and to assess potential etiologic differences in patients with and without these lower extremity aneurysms. We studied 313 consecutive patients with AAAs encountered from 1995 to 1998 who underwent prospective ultrasound scanning to detect the presence or absence of femoral and popliteal aneurysms. Patients with and without these extremity aneurysms were compared for differences in potential etiologic risk factors with each other and with a statewide population of patients with AAAs. A total of 51 femoral and popliteal aneurysms were encountered, all occurring in male patients. Among the 251 men with AAAs, the incidence of femoral or popliteal aneurysms was 14%, compared with 0% among the 62 women with AAAs (P <.01). A family history of aneurysmal disease was present in only one (3%) of the 36 men with these extremity arterial aneurysms, a significant finding (P <.01) when compared with the family history that was positive for aneurysmal disease in 14 women (23%). Peripheral arterial occlusive disease affected 14 (39%) of the 36 men with peripheral arterial aneurysms versus 20 (9%) of the 215 men without these aneurysms (P <.01). Most other etiologic variables studied proved not to be different among the various groups of patients examined. The incidence of femoral and popliteal aneurysms in persons with AAAs appears higher than that noted previously. Femoral and popliteal aneurysmal disease preferentially affects men; however, the basis for this sex difference is unknown. Few common etiologic factors differed between men with and without these extremity aneurysms. Most femoral and popliteal artery aneurysms in this study were undetectable on physical examination, suggesting that ultrasound scanning is appropriate in the recognition of peripheral aneurysms among men with AAAs.
  Journal of Vascular Surgery 05/2000; 31(5):863-9. · 3.21 Impact Factor
• Article: Effects of somatostatin, somatostatin analogs, and endothelial cell somatostatin gene transfer on smooth muscle cell proliferation in vitro.

  R Sarkar, C J Dickinson, J C Stanley
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  ABSTRACT: Somatostatin analogs inhibit neointimal hyperplasia and smooth muscle cell (SMC) proliferation in vivo. The gene transfer of somatostatin to endothelial cells (ECs) represents a potential means of local delivery of somatostatin to areas of arterial injury. This study tested the hypothesis that the retroviral gene transfer of somatostatin to ECs would inhibit SMC proliferation in vitro and evaluated the effects of somatostatin analogs on DNA synthesis and the growth of SMCs. Media transfer and coculture were used to determine the effects of somatostatin-producing ECs on SMC proliferation in vitro. The effects of a variety of somatostatin isoforms and analogs on the proliferation of SMCs, mitogenesis of serum-restimulated quiescent SMCs, and arterial explants were measured. Despite the production of biologically relevant concentrations of somatostatin by ECs, no inhibition of SMC proliferation was noted. Somatostatin analogs inhibited DNA synthesis in arterial explants but did not inhibit either DNA synthesis or growth of cultured SMCs, which showed a likely effect of somatostatin on the initial transition in SMC phenotype. Somatostatin exerts inhibitory effects on SMC proliferation only during the early transition to a proliferative phenotype. There are significant differences between this in vivo transition and the standard serum-restimulated model of cultured SMCs. These differences may account for the failure of somatostatin to inhibit SMC proliferation in the standard in vitro models.
  Journal of Vascular Surgery 05/1999; 29(4):685-93. · 3.21 Impact Factor
• Article: An assessment of contributions made by extracranial tissues during cerebral oximetry.

  S K Samra, J C Stanley, G B Zelenock, P Dorje
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  ABSTRACT: This study was designed to determine the extent of contribution made by extracranial tissues to estimation of regional cerebrovascular saturation (ScO2) during cerebral oximetry. Thirty four patients undergoing carotid endarterectomy under regional anesthesia were studied. Bilateral ScO2 monitoring with two INVOS 3100 A cerebral oximeters was used. Effect of occlusion of external carotid artery (ECA) for five minutes on ScO2 readings followed by occlusion of internal and common carotid arteries was studied. ScO2 readings at 1 minute intervals were stored on computer disks for off-line analysis. Numerical data were subjected to a two way repeated measures analysis of variance to study the effect of side (ipsilateral or contralateral) and phase (pre clamp, ECA clamp, ICA clamp and post clamp) of operation. A value of p<0.05 was considered significant. There was no significant change in ScO2 on the contralateral side. On the ipsilateral hemisphere ScO2 decreased from 67.4+/-8.5 to 65.6+/-8.3 with ECA occlusion and to 61.4+/-9.6 after ICA occlusion returning to 64.8+/-9.8 after all clamps were released. Decrease after ECA occlusion was not significant (p = 0.12) while that after ICA occlusion was significant when compared to pre clamp value (p<0.001). After release of all clamps ipsilateral ScO2 returned toward baseline but remained significantly lower (p<0.05) than pre clamp values. When readings from two hemispheres were compared, a significant difference (p<0.001) was noted during ICA occlusion only. We conclude that the mathematical algorithm used for calculation of ScO2 by INVOS 3100 A cerebral oximeter measures predominantly the intracranial cerebrovascular saturation.
  Journal of Neurosurgical Anesthesiology 01/1999; 11(1):1-5. · 2.23 Impact Factor
• Source

  Available from: stanford.edu

  Article: Prospective, randomized comparison of deep or superficial cervical plexus block for carotid endarterectomy surgery.

  M D Stoneham, A R Doyle, J D Knighton, P Dorje, J C Stanley
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  ABSTRACT: Carotid endarterectomy may be performed under cervical plexus block with local anesthetic supplementation by the surgeon as necessary during surgery. It is unclear, however, whether deep or superficial cervical plexus block offers the best operating conditions or patient satisfaction. Therefore, the authors compared the two in patients undergoing carotid endarterectomy. Forty patients undergoing carotid endarterectomy were randomized to receive either a superficial or a deep cervical plexus block with 20 ml bupivacaine, 0.375%. Outcomes subjected to statistical analysis included supplemental anesthetic supplementation with lidocaine, 1%, by the surgeon, dermatomes affected by the block, paresthesia during block placement, postoperative pain scores, and analgesic requirements. Median supplemental lidocaine requirements were 6 ml (range, 0.5 to 20 ml) in the deep block group and 6 ml (range, 0 to 20 ml) in the superficial block group (P = 0.7323). Patients in the deep block group who reported paresthesia during block placement required less lidocaine supplementation (median, 2; range, 0.5 to 20 ml) than the 9.5 ml (range, 6 to 15.5 ml) required by those who did not experience paresthesia (P = 0.0113). Compared with patients in the superficial block group, those in the deep block group were less likely to need analgesia in the first 24 h after operation (P = 0.047), and those who required analgesia received it later (6.6 +/- 4.1 vs. 3.9 +/- 1.4 h after operation; Student's t test, P = 0.02). One patient in each group expressed dissatisfaction with the technique. Carotid endarterectomy may be performed satisfactorily during superficial or deep cervical plexus block placement with no differences in terms of supplemental local anesthetic requirements, although this is influenced by whether paresthesia is elicited during placement of the deep block. Therefore, the clinician's decision to use one block rather than another need not be based on any assumed superiority of one block based on intraoperative conditions or patient satisfaction.
  Anesthesiology 11/1998; 89(4):907-12. · 5.36 Impact Factor
• Article: Excessive oral amphetamine use as a possible cause of renal and splanchnic arterial aneurysms: a report of two cases.

  T H Welling, D M Williams, J C Stanley
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  ABSTRACT: Multiple visceral aneurysms are uncommon and usually result from connective tissue diseases, systemic arteritis, or mycotic lesions. An association between multiple visceral aneurysms and excessive oral amphetamine use has not been reported. The clinical features of 2 patients at the University of Michigan Medical Center for treatment of multiple visceral aneurysms and amphetamine use were reviewed. The patients had histories of excessive oral amphetamine use that ranged from 50 mg daily for 22 years to 200 mg daily for 2 years. No evidence was seen of systemic arteritis, connective tissue disorder, or an infectious process that may have caused the aneurysms. The arteriograms documented multiple splanchnic and renal artery aneurysms that involved both the large and the small arteries. The aneurysms of 1 patient were managed conservatively, and the patient has not had any clinical sequelae of the aneurysms during 14 years of follow-up. The second patient had hematobilia from a ruptured hepatic artery aneurysm that was treated with transcatheter embolic occlusion of the bleeding vessel. The patient had no recurrent gastrointestinal problems and continued to use amphetamines until his death from a cerebrovascular accident 6 years later. A possible association between excessive oral amphetamine use and multiple visceral aneurysms is reported for 2 patients in whom other risk factors were absent. The potential for chronic oral amphetamine use to cause multiple visceral aneurysms is an ill-defined but not unexpected complication of this substance that is known to contribute to arterial hypertension and to produce a form of necrotizing arteritis.
  Journal of Vascular Surgery 11/1998; 28(4):727-31. · 3.21 Impact Factor
• Article: Renal anatomic changes on magnetic resonance imaging and gadolinium-enhanced magnetic resonance angiography after renal revascularization. Original investigation.

  R C Carlos, M R Prince, J S Ward, J C Stanley, Q Dong, F J Londy
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  ABSTRACT: The anatomic and hemodynamic renal changes after renal arterial revascularization (RAR) were investigated. Thirty-seven kidneys and 40 renal arteries were evaluated in 20 patients by using magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) to assess pre- and post-RAR renal length and mass, parenchymal thickness, renal enhancement, renal artery caliber, poststenotic dilation, and signal dephasing on 3D phase contrast (PC). The kidneys and renal arteries were segregated into three groups. Group 1 included 16 patients who benefited from RAR (defined as clinical improvement based on decreased serum creatinine or fewer number of antihypertensive medications) in whom 26 renal arteries in 25 kidneys were studied. Intervention included renal artery endarterectomy (n = 20); aortorenal bypass (n = 3); renal artery reimplantation (n = 3); and percutaneous transluminal angioplasty (PTA; n = 1). A total of 27 interventions was performed, as PTA failed for one patient who subsequently underwent aortorenal bypass before reimaging. Group 2 included four patients who did not clinically benefit. A total of eight revascularized arteries were studied in seven kidneys. In group 3, six renal arteries in five kidneys from groups 1 and 2 without RAS/RAR were analyzed as an internal control. Technical success (defined as increased vessel caliber after intervention) was achieved in 33 of the 34 revascularized arteries. A statistically significant increase in renal length occurred regardless of clinical outcome (pre-RAR, 9.5 cm; post-RAR, 10.5 cm; P < 0.0001). Parenchymal thickness and renal mass, however, improved only in patients who benefited clinically from RAR. Parenchymal enhancement was unchanged in any of the groups studied. No significant morphologic changes were detected in the control group. Magnetic resonance imaging and Gd-MRA detect anatomic and hemodynamic changes that occur with renal revascularization.
  Investigative Radiology 09/1998; 33(9):660-9. · 4.59 Impact Factor
• Article: Somatostatin gene transfer and expression in endothelial cells.

  R Sarkar, S Finniss, C J Dickinson, J C Stanley
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  ABSTRACT: The antiproliferative and antisecretory effects of somatostatin have many potential uses in the clinical setting. Retroviral gene transfer of somatostatin to endothelium is a potential means of local delivery of this peptide to specific vascular beds. This investigation was designed to determine whether transduced endothelial cells (ECs) could produce and post-translationally process somatostatin. Cultured canine venous, rat aortic, and rat microvascular ECs were transfected with retroviruses containing a human somatostatin cDNA or a control beta-galactosidase gene. Total and isoform somatostatin production and uniformity of beta-galactosidase expression were analyzed, as were the effects of somatostatin production on EC proliferation. Somatostatin-transduced canine venous ECs, but not rat ECs, produced approximately 10 times as much total somatostatin as did control-transfected ECs (450 +/- 32 vs 49 +/- 10 pmol/L, p < 0.05). The predominant isoform of somatostatin produced was somatostatin-14. Production of somatostatin was stable with passage and did not impair the growth of canine ECs. The failure of rat ECs to produce somatostatin correlated with nonuniform expression of beta-galactosidase, suggesting that promoter silencing was responsible for failure of transgene expression. Retroviral gene transfer of somatostatin to canine ECs results in the production of physiologically relevant concentrations of biologically active somatostatin. Significant species differences exist in EC production of somatostatin, with promoter silencing being a potential mechanism of failure of gene expression. Gene therapy strategies using retroviral transfer of somatostatin to ECs may allow somatostatin delivery to focal areas of the vasculature.
  Journal of Vascular Surgery 06/1998; 27(5):955-62. · 3.21 Impact Factor
• Article: Presidential address: The American Board of Vascular Surgery.

  J C Stanley
  Journal of Vascular Surgery 02/1998; 27(2):195-202. · 3.21 Impact Factor
• Article: A novel protamine variant reversal of heparin anticoagulation in human blood in vitro.

  M S Hulin, T W Wakefield, P C Andrews, S K Wrobleski, M D Stoneham, A R Doyle, G B Zelenock, L A Jacobs, C J Shanley, V M TenCate, J C Stanley
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  ABSTRACT: Protamine reversal of heparin anticoagulation during cardiovascular surgery may cause severe hypotension and pulmonary hypertension. A novel protamine variant, [+18RGD], has been developed that effectively reverses heparin anticoagulation without toxicity in canine experiments. Heretofore, human studies have not been undertaken. This investigation hypothesized that [+18RGD] would effectively reverse heparin anticoagulation of human blood in vitro. Fifty patients who underwent anticoagulation therapy during vascular surgery had blood sampled at baseline and 30 minutes after receiving heparin (150 IU/kg). Activated clotting times were used to define specific quantities of [+18RGD] or protamine necessary to completely reverse heparin anticoagulation in the blood sample of each patient. These defined amounts of [+18RGD] or protamine were then administered to the heparinized blood samples, and percent reversals of activated partial thromboplastin time, thrombin clotting time, and antifactor Xa/IIa levels were determined. In addition, platelet aggregation assays, as well as platelet and white blood cell counts were performed. [+18RGD] and protamine were equivalent in reversing heparin as assessed by thrombin clotting time, antifactor Xa, antifactor IIa levels, and white blood cell changes. [+18RGD], when compared with protamine, was superior in this regard, as assessed by activated partial thromboplastin time (94.5 +/- 1.0 vs 86.5 +/- 1.3% delta, respectively; p < 0.001) and platelet declines (-3.9 +/- 2.9 vs -12.8 +/- 3.4 per mm3, respectively; p = 0.048). Platelet aggregation was also decreased for [+18RGD] compared with protamine (23.6 +/- 1.5 vs 28.5 +/- 1.9%, respectively; p = 0.048). [+18RGD] was as effective as protamine for in vitro reversal of heparin anticoagulation by most coagulation assays, was statistically more effective at reversal than protamine by aPTT assay, and was associated with lesser platelet reductions than protamine. [+18RGD], if less toxic than protamine in human beings, would allow for effective clinical reversal of heparin anticoagulation.
  Journal of Vascular Surgery 12/1997; 26(6):1043-8. · 3.21 Impact Factor
• Source

  Available from: Lazar J Greenfield

  Article: Differential clinical workloads among faculty at a major academic health center.

  G B Zelenock, J C Stanley, R A More, L J Greenfield, C J Shanley, L A Jacobs
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  ABSTRACT: The authors analyzed patient care (1981-1995) and financial data (1991-1996) to determine if differential workloads existed at a major academic health center. Academic health centers differ markedly from community-based medical centers, but they are required to compete with others who have a more circumscribed mission and a responsibility for providing less complex care. Changes in health care systems may lessen incentives to generate clinical revenue and may adversely affect educational and research programs. Patient care data at the University of Michigan Health System were analyzed by discipline for level of activity from 1981 to 1995 and were compared to professional and institutional financial data from 1991 to 1995. Surgeons represented 11% of the total full-time physicians throughout the period of the study (94 of the 836 Medical Center physicians, 1995). They accounted for 33% of hospital admissions (11,616 of 35,101) and 16% of outpatient visits (92,364 of 568,738). Since 1981, surgeons experienced a 249% increase in total operative workload (6799-16,909 procedures), representing a 30% increase in operations/surgeon (138-180 operations). Surgical efforts in 1995 accounted for 29% of the total professional fee revenue and $240 million of the $512-million University of Michigan Hospital revenue. Surgeons had a greater collective and individual responsibility than did nonsurgeons for clinical activity and the financial viability of the academic health centers studied. Many proposals for financing health care delivery systems have the potential to exacerbate this differential. Restructuring of academic health centers must address this fact, lest their academic mission and scholarly activity be compromised.
  Annals of Surgery 10/1997; 226(3):336-45; discussion 345-7. · 7.49 Impact Factor
• Article: Hemodynamically significant atherosclerotic renal artery stenosis: MR angiographic features.

  M R Prince, S O Schoenberg, J S Ward, F J Londy, T W Wakefield, J C Stanley
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  ABSTRACT: To identify magnetic resonance (MR) angiographic features of hemodynamically significant renal artery stenosis. Forty-seven patients underwent MR angiography of the renal arteries, including T1-weighted spin-echo and three-dimensional gadolinium-enhanced spoiled gradient-echo and three-dimensional phase-contrast pulse sequences, followed by renal revascularization. Thirty-five patients (52 arteries) were identified who benefited from renal revascularization, which indicated that they had hemodynamically significant renal artery stenoses. Kidney length, cortical thickness, parenchymal enhancement, and poststenotic dilatation were measured. Arteries were also examined for signal drop-out (dephasing) on phase-contrast angiograms; dephasing was considered severe if the stenotic artery appeared occluded on phase-contrast angiograms. Poststenotic dilatation of greater than 20% was present in 36 (59%) of 52 hemodynamically significant renal artery stenoses, and severe dephasing was present in 45 (87%) of 52. In patients with unilateral hemodynamically significant stenosis or occlusion, mean ischemic kidney length was reduced to 9.3 cm compared with 10.7 cm for the contralateral normal kidney (P = .009), mean parenchymal thickness was reduced (1.2 vs 1.7 cm; P < .001), and mean parenchymal enhancement was 15% less on the ischemic side (P = .05). Severe dephasing on phase-contrast angiograms was present in nine (75%) of 12 unilateral hemodynamically significant stenoses but in only one contralateral normal renal artery (P < .001). MR angiography depicts features of renal artery stenosis that are markers of hemodynamic significance.
  Radiology 10/1997; 205(1):128-36. · 5.73 Impact Factor