Sudden unexpected death in epilepsy associated with progressive deterioration in heart rate variability.

We describe a patient with severe epilepsy who underwent serial measurements of heart rate variability (HRV) prior to his death from autopsy-confirmed sudden unexpected death in epilepsy (SUDEP). The significance of low HRV is discussed in relation to SUDEP risk. Progressive deterioration in HRV may be a risk factor for SUDEP.

Increased platelet:RBC ratios are associated with improved survival after massive transfusion.

BACKGROUND: Several recent military and civilian trauma studies demonstrate that improved outcomes are associated with early and increased use of plasma-based resuscitation strategies. However, outcomes associated with platelet transfusions are poorly characterized. We hypothesized that increased platelet:red blood cells (RBC) ratios would decrease hemorrhagic death and improve survival after massive transfusion (MT). METHODS: A transfusion database of patients transported from the scene to 22 Level I Trauma Centers over 12 months in 2005 to 2006 was reviewed. MT was defined as receiving ≥ 10 RBC units within 24 hours of admission. To mitigate survival bias, 25 patients who died within 60 minutes of arrival were excluded from analysis. Six random donor platelet units were considered equal to a single apheresis platelet unit. Admission and outcome data associated with the low (>1:20), medium (1:2), and high (1:1) platelet:RBC ratios were examined. These groups were based on the median value of the tertiles for the ratio of platelets:RBC units. RESULTS: Two thousand three hundred twelve patients received at least one unit of blood and 643 received an MT. Admission vital signs, INR, temperature, pH, Glasgow Coma Scale, Injury Severity Score, and age were similar between platelet ratio groups. The average admission platelet counts were lower in the patients who received the high platelet:RBC ratio versus the low ratio (192 vs. 216, p = 0.03). Patients who received MT were severely injured, with a mean (± standard deviation) Injury Severity Score of 33 ± 16 and received 22 ± 15 RBCs and 11 ± 14 platelets within 24 hours of injury. Increased platelet ratios were associated with improved survival at 24 hours and 30 days (p < 0.001 for both). Truncal hemorrhage as a cause of death was decreased (low: 67%, medium: 60%, high: 47%, p = 0.04). Multiple organ failure mortality was increased (low: 7%, medium: 16%, high: 27%, p = 0.003), but overall 30-day survival was improved (low: 52%, medium: 57%, high: 70%) in the high ratio group (medium vs. high: p = 0.008; low vs. high: p = 0.007). CONCLUSION: Similar to recently published military data, transfusion of platelet:RBC ratios of 1:1 was associated with improved early and late survival, decreased hemorrhagic death and a concomitant increase in multiple organ failure-related mortality. Based on this large retrospective study, increased and early use of platelets may be justified, pending the results of prospective randomized transfusion data.

FDG-PET in patients at risk for acute respiratory distress syndrome: a preliminary report.

OBJECTIVE: To compare the pattern of lung uptake of 18F-fluorodeoxyglucose (FDG) by positron emission tomography (PET) imaging in patients with lung contusion that developed or did not progress to acute respiratory distress syndrome (ARDS). DESIGN: Prospective, observational study. SETTING: Trauma Center (academic urban hospital). PATIENTS AND INTERVENTIONS: Eight patients with blunt thoracic trauma and pulmonary contusion, confirmed by computed tomography (CT) on admission, underwent repeat CT and FDG-PET (on the same day) 24-72 h after admission. RESULTS: No subjects met the criteria for ARDS at the time of the PET and second CT. Four subjects subsequently developed ARDS 1-3 days after the PET scan; the other four did not develop the syndrome. Three of the four subjects who subsequently developed ARDS showed diffuse FDG uptake throughout the entire lungs, while those who did not develop ARDS showed significant FDG uptake only in areas of focal lung opacity (non or poorly aerated lung units) on CT. FDG uptake in normally aerated lung regions was higher for those who subsequently developed ARDS than those who did not, approaching statistical significance. The normally aerated tissue:liver ratio was significantly higher in subjects who developed ARDS than in those who did not (P = 0.029). CONCLUSION: In this small series of patients with thoracic trauma, diffuse lung uptake of FDG was detected by PET imaging 1-3 days prior to clinically determined ARDS.

Nitrous oxide emissions from a Northern Great Plains soil as influenced by nitrogen management and cropping systems.

Field measurements of N2O emissions from soils are limited for cropping systems in the semiarid northern Great Plains (NGP). The objectives were to develop N2O emission-time profiles for cropping systems in the semiarid NGP, define important periods of loss, determine the impact of best management practices on N2O losses, and estimate direct N fertilizer-induced emissions (FIE). No-till (NT) wheat (Triticum Aestivum L.)-fallow, wheat-wheat, and wheat-pea (Pisum sativum), and conventional till (CT) wheat-fallow, all with three N regimes (200 and 100 kg N ha(-1) available N, unfertilized control); plus a perennial grass-alfalfa (Medicago sativa L.) system were sampled over 2 yr using vented chambers. Cumulative 2-yr N2O emissions were modest in contrast to reports from more humid regions. Greatest N2O flux activity occurred following urea-N fertilization (10-wk) and during freeze-thaw cycles. Together these periods comprised up to 84% of the 2-yr total. Nitrification was probably the dominant process responsible for N2O emissions during the post-N fertilization period, while denitrification was more important during freeze-thaw cycles. Cumulative 2-yr N2O-N losses from fertilized regimes were greater for wheat-wheat (1.31 kg N ha(-1)) than wheat-fallow (CT and NT) (0.48 kg N ha(-1)), and wheat-pea (0.71 kg N ha(-1)) due to an additional N fertilization event. Cumulative losses from unfertilized cropping systems were not different from perennial grass-alfalfa (0.28 kg N ha(-1)). Tillage did not affect N2O losses for the wheat-fallow systems. Mean FIE level was equivalent to 0.26% of applied N, and considerably below the Intergovernmental Panel on Climate Change mean default value (1.25%).

Substance abuse attitude changes in medical students.

The authors describe a course in substance abuse given to sophomore medical students with the intention of positively influencing their attitudes toward substance-abusing patients and their treatment. Clinical problem solving and small group discussion were emphasized in addition to field trips. By pretest and posttest measures, significant positive changes were obtained in student attitudes: they reported feeling less upset when they encountered alcoholics, "hard" drug abusers, "soft" drug abusers, compulsive smokers, and obese overeaters as well as having a more positive view of the physician's role in the treatment of substance dependence. Personal experience with alcohol and other drugs was shown to have an influence on attitude changes.

Enalaprilat improves gut perfusion in critically injured patients.

Inadequate splanchnic perfusion, detected as a low gastric intramucosal pH (pHi), in the face of normal systemic perfusion predicts an increased risk for multiple organ failure after trauma. Although the exact etiology of this low pHi is unknown, angiotensin II is thought to be an important regulator of gut perfusion during and after resuscitation from shock. The purpose of this study is to determine whether enalaprilat, an angiotensin-converting enzyme inhibitor, improves gut perfusion in critically injured patients. To test this hypothesis, 18 trauma patients monitored with a nasogastric tonometer and a pulmonary artery catheter were enrolled in a prospective study. A single dose of enalaprilat, .625 mg, was given as an i.v. bolus or a 4 h infusion following systemic resuscitation. Pre- and postdrug tonometric and hemodynamic data, including cardiac index, mean arterial pressure, right ventricular end-diastolic volume index, systemic vascular resistance index, and oxygen transport variables were compared using the paired t test. Results demonstrate that pHi was significantly improved after 4 h (7.13 +/- .04 to 7.19 +/- .03, p = .03) and after 24 h compared with baseline (7.14 +/- .04 to 7.25 +/- .04, p = .04). Overall, pHi increased in 12 of 18 patients. No significant differences were observed in any of the studied hemodynamic or systemic perfusion variables including mean arterial pressure (92 +/- 4 to 87 +/- 4, p = .24) and oxygen delivery (669 +/- 33 to 675 +/- 32, p = .82). In examining the determinants of pHi, the intramucosal-arterial PCO2 difference was improved after enalaprilat administration (27 +/- 6 to 17 +/- 3 mmHg, p = .04) while no difference was observed in arterial bicarbonate (19.5 +/- .7 to 19.7 +/- .8, p = .90). Additionally, the change in pHi observed with enalaprilat correlated with predrug intramucosal-arterial PCO2 difference (r = .74, r2 = .55, p = .0005). These results demonstrate that enalaprilat improves gut perfusion as measured by gastric tonometry in critically injured patients, and that this effect appears to be independent of changes in systemic perfusion.

Clinical application of ventricular end-systolic elastance and the ventricular pressure-volume diagram.

The ability to clinically assess myocardial contractility in a load-independent fashion facilitates the selection of appropriate inotropes, when needed, during shock resuscitation. Within the framework of the ventricular pressure-volume diagram, the slope of the ventricular end-systolic pressure-volume relationship (expressed as ventricular end-systolic elastance, Ees), has been shown to accurately reflect ventricular inotropic state, and to be insensitive to loading conditions. It has not, however, been widely used at the bedside. Our goal was to evaluate the clinical utility of Ees and the ventricular pressure-volume diagram as bedside methods of hemodynamic assessment. We performed a prospective study of 123 hemodynamic interventions in 100 trauma patients during shock resuscitation in which contractility (Ees), preload (left ventricular end-diastolic volume index), and afterload (effective arterial elastance) were calculated before and after addition of inotropes, fluid bolus, and afterload reduction. Mean values of each variable were compared before and after each type intervention using the paired t test. The ventricular pressure-volume diagram was used to predict changes in the studied variables, and the experimental results were compared with predicted changes. Ees (mmHg/mL/m2) increased significantly with inotropes (4.7 +/- 3.2 to 10 +/- 8.7, p < .0001), but was not affected by clinically significant fluid administration (7.0 +/- 4.7 to 8.3 +/- 8.0, p = .10) or afterload reduction (9.6 +/- 5.2 to 9.2 +/- 4.7, p = .72). Left ventricular end-diastolic volume index (mL/m2) improved with fluid administration (54 +/- 8.9 to 62 +/- 9.8, p < .0001) and effective arterial elastance (mmHg/mL/m2) decreased with afterload reduction (3.3 +/- .9 to 2.6 +/- .7, p < .0001). We conclude that Ees is a load-independent measure of contractility, which is measurable at the bedside. The pressure-volume diagram is a useful method of monitoring hemodynamic changes associated with interventions during shock resuscitation.

Effects of v-src oncogene activation on radiation sensitivity in drug-sensitive and in multidrug-resistant rat fibroblasts.

Recent work has implicated the activated ras oncogene, whose gene product is a G-protein located in the plasma membrane, as well as the activated raf oncogene, whose gene product is a membrane-associated protein kinase, in contributing to radioresistance. Another transforming oncogene whose gene product is localized to the plasma membrane is v-src. We have examined a rat fibroblast line (RAT-1) infected with an avian sarcoma virus carrying a temperature-sensitive mutation in the v-src tyrosine kinase domain (LA-24). At 40 degrees C, LA-24 cells have a flat morphology and grow as a contact-inhibited monolayer, while at 35 degrees C, LA-24 cells have a transformed morphology, lose contact inhibition, grow in soft agar, and exhibit 3.5-fold higher tyrosine kinase activity. The parental RAT-1 line, not infected by the virus, grows at both temperatures as a contact-inhibited monolayer. This well-characterized system represents a good model for examining the effect of v-src transformation on radiosensitivity. RAT-1 and LA-24 cells grown at 35 and 40 degrees C were irradiated with graded doses of radiation, and clonogenic survival was assayed. For LA-24 cells grown at 35 and 40 degrees C, and for RAT-1 cells grown at 35 and 40 degrees C, calculated D0, n, alpha, and beta values did not differ significantly. To determine whether there might be differences in radiation damage repair capacity too subtle to detect by comparing radiation survival curves, sublethal damage repair capacity was assessed. There was no difference in sublethal damage repair capacity for LA-24 cells grown at 35 or 40 degrees C. Other studies have associated multidrug resistance with radioresistance. We have examined the radiation sensitivity of two colchicine-resistant LA-24 clones with four- to fivefold amplification of the P-glycoprotein gene, which are four-to fivefold more resistant to colchicine than the parental LA-24 line. In these multidrug-resistant clones, v-src activation does appear to increase radiation resistance. This did not appear to be due to alteration in cell cycle kinetics. We conclude that oncogene activation, or even protein kinase activity per se, does not necessarily lead to radiation resistance. Rather, radiation resistance following oncogene activation depends upon the oncogene and cell line studied, and perhaps upon specific protein phosphorylation.

Radiation-induced gastrointestinal stromal sarcoma of the esophagus.

Esophageal sarcoma is an uncommon tumor, sporadically reported in the literature. Radiation therapy is frequently employed in the treatment of carcinoma of the esophagus, and the increased risk of development of sarcoma arising in irradiated fields is well known. However, to our knowledge, the occurrence of radiation-associated sarcoma of the esophagus after radiation therapy for carcinoma of the esophagus has not been reported. We therefore report the case of a 43-year-old female who developed a gastrointestinal stroma sarcoma 9 years following radiation therapy for esophageal squamous cell carcinoma. The patient underwent resection of her gastrointestinal stromal sarcoma by transhiatal esophagectomy with cervical anastomosis and is doing well 18 months later. The increasing use of radiation therapy for esophageal carcinoma suggests that radiation-associated sarcoma of the esophagus may be seen more frequently in the future.

Elevated arterial base deficit in trauma patients: a marker of impaired oxygen utilization.

BACKGROUND: In trauma patients, the admission value of arterial base deficit stratifies injury severity, predicts complications, and is correlated with arterial lactate concentration. In theory, elevated base deficit and lactate concentrations after shock are related to oxygen transport imbalance at the cellular level. The purpose of this study was to test the hypothesis that an elevated base deficit in trauma patients is indicative of impaired systemic oxygen utilization and portends poor outcomes. METHODS: This study was a retrospective analysis of a prospectively collected database. The study population included all patients admitted to the trauma intensive care unit at a Level 1 trauma center during a 12-month period who were monitored with a pulmonary artery catheter and serial measurements of lactate and base deficit, and who achieved a normal arterial lactate concentration (< 2.2 mmol/L) with resuscitation. The patients were divided into those who maintained a persistently high base deficit (> or = 4 mmol/L) and those who achieved a low base deficit (< 4 mmol/L) during resuscitation. RESULTS: One-hundred patients (mortality 20%) were monitored with a pulmonary artery catheter and achieved a normal arterial lactate concentration. The mean age+/-SD (SEM) of the group was 37+/-17 years and the Injury Severity Score was 25+/-11. Subgroup analysis revealed that patients with a persistently high base deficit (n=26) had higher rates of multiple organ failure (35% versus 5%, p < 0.001) and death (50% versus 9%, p < 0.00001) compared with patients who achieved a low base deficit. Patients with a persistently high base deficit also had lower oxygen consumption (126+/-40 mL/m2 versus 156+/-30 mL/m2, p=0.01 at 48 hours) and a lower oxygen utilization coefficient (0.20+/-0.05 versus 0.24+/-0.03, p=0.01 at 48 hours) compared with patients with a low base deficit. At 48 hours, both oxygen consumption (r=-0.44, [r, correlation coefficient] p=0.002) and oxygen utilization (r=-0.46, p=0.001) had a significant negative correlation with base deficit. CONCLUSIONS: In trauma patients, a persistently high arterial base deficit is associated with altered oxygen utilization and an increased risk of multiple organ failure and mortality. Serial monitoring of base deficit may be useful in assessing the adequacy of oxygen transport and resuscitation.

Color perception with test and adapting lights perceived in different depth planes.

Adapting to a chromatic light can alter the color appearance of other lights in view. The chromatic adapting effect is measured here with the test and adapting field perceived in the same depth plane, or perceived in different depth planes (using stereo disparity). The measurements show only a weak, though consistent, shift in the appearance of the test when adapting field and test are perceived in different depth planes, compared to when they are in the same plane. Adding complexity to the adapting stimulus, in the form of a second chromatic light surrounding the background, alters the appearance of the test but shows no dependence on the depth relations. Overall, there is only a small difference in chromatic adaptation caused by introducing a three-dimensional representation of these stimuli.

Location of Zn within the Mg12(LaxCe1-x) lattice by X-ray incoherent channelling patterns.

Systematic electron diffraction studies on intermetallic precipitates formed within a lightweight Mg-RE-Zn alloy (RE = La or Ce) identify these to be of structural type Mn(12)Th (space group I4/mmm). Analytical electron microscopy yields an overall composition of Mg(12)(La(x)Ce(1-x)) with x ~ 0.43, with 1 at.% Zn incorporated within the lattice. Variations in characteristic X-ray emission rates, as an electron beam is rocked near zone-axis orientations, are used to form two-dimensional channelling patterns, termed X-ray incoherent channelling patterns. This channelling contrast enables a specific sublattice site that is occupied by Zn to be unambiguously identified within the Mg(12)RE lattice. The particular sublattice site is denoted by the Wyckoff letter f, and is one of the three different Mg sublattice sites f, i and j. Of these three sites, the Wigner-Seitz cell that is centred on the f sublattice site has the largest Mg-RE interatomic distance, and therefore the f site is expected to be favoured for accommodating the substitution of a larger Zn atom.

Inpatient diagnostic assessments: 2. Interrater reliability and outcomes of structured vs. unstructured interviews.

A preceding study found that structured interviews (SCID-CV, Computer Assisted Diagnostic Interview [CADI]) were significantly more accurate than the unstructured Traditional Diagnostic Assessment (TDA) for making inpatient diagnoses, using Consensus Diagnosis as the standard. This study measured interrater reliability for diagnoses between the Emergency Room (ER) and the Inpatient Unit (IU), as achieved by TDA vs. CADI. It selected subjects from consecutive admissions to the ER who were transferred to the IU. Group 1 had 33 subjects evaluated with TDA, leading to interrater agreement=45.5% (15/33) and kappa=0.24 ('poor'). Group 2 had 39 subjects evaluated with CADI, leading to interrater agreement=79.5% (31/39) and kappa=0.75 ('excellent'). Group 3 had 33 subjects, again evaluated with TDA, leading to interrater agreement=54.5% (18/33) and kappa=0.43 ('fair'). The test-retest-test (TDA-CADI-TDA) format demonstrated that CADI had better interrater reliability than TDA. How diagnostic reliability might correlate with parameters like timing of treatment choices and length of stay are also measured and discussed.

Inpatient diagnostic assessments: 1. Accuracy of structured vs. unstructured interviews.

This study compared structured vs. unstructured interviews for making psychiatric diagnoses. Three clinicians independently diagnosed 56 inpatient-subjects, each using a different method: (1) the unstructured Traditional Diagnostic Assessment (TDA), the standard method of clinical practice; (2) the Structured Clinical Interview for DSM-Clinical Version (SCID-CV), a widely used structured method; and (3) the Computer Assisted Diagnostic Interview (CADI), a structured computer-based method. Once finished, the three clinicians developed a Consensus diagnosis, using Spitzer's LEAD Standard (L=Longitudinal evaluation of symptomatology, E=Evaluation by expert consensus, AD=All Data from multiple sources). Diagnoses were assigned to one of 10 groups (cognitive impairment, general medical condition-induced, alcohol-induced, drug-induced, mania, depression, schizophrenia, schizoaffective, psychosis NOS, and anxiety). Diagnostic accuracy for each method, measured against Consensus, was as follows: TDA-agreement=53.8%, kappa=0.4325 ('fair'); SCID-CV-agreement=85.7%, kappa=0.8189 ('excellent'); CADI -agreement=85.7%, kappa=0.8147 ('excellent'). All three methods reached acceptable levels of diagnostic accuracy. Structured methods (SCID-CV, CADI) were significantly better than the unstructured TDA.

MR features of osteoarthritis of the knee.

A group of patients with idiopathic osteoarthritis (OA) of the knee was surveyed using weight-bearing radiographs and MR imaging to compare the relative value of these methods in disease evaluation. Fifty-two patients with a clinical and radiological diagnosis of OA of the knee of relatively short duration (87%: < or = 4 yr) were compared to a reference group of 40 age- and sex-comparable subjects with no knee symptoms. All patients had a complete history, physical examination, standard anterior-posterior and lateral weight-bearing radiographs, T1-weighted, and FLASH MR images in both knees. The prevalence of MRI abnormalities was significantly greater in patients with OA of the knee in all radiographic grades (Kellgren and Lawrence) compared to the reference subjects. Significant differences were encountered for synovial thickening (OA, 73%; reference, 0%), synovial fluid (60%; 7%), meniscal degeneration (52%; 7%), osteophytes (67%; 12%), and subchondral bone involvement (65%; 7%), even in the patients at the mild end of the osteoarthritic spectrum, indicating the exquisite sensitivity of MRI compared with weight-bearing radiographs.

Synovial thickening detected by MR imaging in osteoarthritis of the knee confirmed by biopsy as synovitis.

Previous studies have established the value of magnetic resonance imaging (MRI) in detecting articular changes characteristic of osteoarthritis (OA) of the knee. We have observed some MRI features in OA of the knee presumably indicating synovial thickening. To determine whether these MR features represent chronic synovial inflammation, we studied the knees of nine patients at the mild end of the spectrum of OA of relatively short duration (89%: < or = 4 yr), who were selected because MRI showed anatomical abnormalities compatible with synovial thickening. The painful knee was examined using conventional and weight-bearing radiographs, MRI, and arthroscopy. MR images suggestive of synovial thickening typically appeared in or near the intercondylar region of the knee, in the infrapatellar fat pad, or in the posterior joint margin. The site of an arthroscopic biopsy of the synovial membrane was guided by MRI to the area thought to represent synovial thickening for each patient knee. Pathological examination of these synovial membrane biopsies showed a mild chronic synovitis, and thus a correspondence with the synovial thickening detected by MRI. Our results suggest that MRI can be used to evaluate the extent of synovitis, observed as synovial thickening, in patients with early OA of the knee.

Detection and quantification of laryngotracheopulmonary aspiration with scintigraphy.

Aspiration is analyzed by a new scintigraphic technique and standard videofluoroscopy in 78 patients with head and neck pathology and neurologic disorders. When both methods are compared to clinical aspiration and a positive x-ray film of pneumonia, they appear to complement each other and provide a very accurate evaluation. Scintigraphy is a more sensitive method for detecting aspiration below the vocal cords and also provides for flow dynamics and a method of quantifying the amount of aspirated material. Videofluoroscopy shows more clearly the mechanism of the swallowing disorder and how the bolus enters the tracheobronchial tree. Studies in patients following head and neck surgery demonstrate a high incidence of dysphagia, aspiration, and pneumonia.

Radiation resistance in a doxorubicin-resistant human fibrosarcoma cell line.

In clinical practice, cancers refractory to chemotherapy can appear relatively radioresistant. Recent work in multidrug-resistant cell lines has yielded conflicting results concerning the relationship between drug resistance and radiation resistance. The current study examines the radiation response of a human fibrosarcoma (HT1080) and a doxorubicin-resistant subline (HT1080/DR4). Using soft-agar colony formation after graded doses of x-rays as an endpoint, HT1080/DR4 had an increased D0 (D0 = 2.1 Gy) and a broader initial shoulder (n = 2.7, Dq = 2.1 Gy) than the parental HT1080 line (D0 = 0.7, Gy, n = 1.2, Dq = 0.3 Gy), suggesting that HT1080/DR4 has an increased capacity to repair radiation-induced DNA damage. This possibility was tested by comparing the cell lines' ability to accumulate sublethal damage. In split-dose recovery experiments, HT1080/DR4 demonstrated increased ability to repair sublethal radiation damage following fractionated irradiation, compared with the HT1080 parental line. The mechanism for this radiation resistance is not clear, but a variety of cellular alterations seen in drug-resistant cell lines are discussed with reference to areas of further study.

Blunt renal artery injury: incidence, diagnosis, and management.

Renal artery injury is a rare complication of blunt abdominal trauma. Increasing use of CT scans to evaluate blunt abdominal trauma identifies more blunt renal artery injuries (BRAIs) that may have otherwise been missed. We identified patients with BRAI to examine the incidence and to evaluate the current diagnosis and management strategies. Patients admitted from 1986 to 2000 at a regional Level I trauma center sustaining BRAI were evaluated. Patients undergoing revascularization or nonoperative management were followed for renovascular hypertension. Twenty-eight patients with BRAI were identified out of 36,938 blunt trauma admissions between 1986 and 2000 (incidence 0.08%). Most renal artery injuries were diagnosed by CT scans (93%) with seven confirmatory angiograms. Nine patients had nephrectomy (one bilateral), and three patients with unilateral injuries were revascularized. Sixteen were managed nonoperatively including one patient who had endovascular stent placement. Three patients died from shock and sepsis. Follow-up for all patients ranged from one month to 8 years. Two patients developed hypertension: one who was revascularized (33%) and one was managed nonoperatively (6%). The frequency of diagnosis of BRAI is increasing because of the increased use of CT. Nonoperative management of unilateral injuries can be successful with a 6 per cent risk for developing renovascular hypertension. The role of endovascular stenting is promising, and further study is necessary.