Outcomes following carotid revascularization for stroke stratified by Modified Rankin Scale and time of intervention

OBJECTIVES

The relationship between baseline Modified Rankin Scale (mRS) in patients with prior stroke and optimal timing of carotid revascularization is unclear. Therefore, we evaluated the timing of transfemoral carotid artery stenting (tfCAS), transcarotid artery revascularization (TCAR), and carotid endarterectomy (CEA) after prior stroke, stratified by preoperative mRS.

METHODS

We identified patients with recent stroke who underwent tfCAS, TCAR, or CEA between 2012 and 2021. Patients were stratified by preoperative mRS (0-1, 2, 3-4, or 5) and days from symptom onset to intervention (time to intervention; ≤2 days, 3-14 days, 15-90 days, and 91-180 days). First, we performed univariate analyses comparing in-hospital outcomes between separate mRS or time-to-intervention cohorts for all carotid intervention methods. Afterward, multivariable logistic regression was used to adjust for demographics and comorbidities across groups, and outcomes between the various intervention methods were compared. Primary outcome was the in-hospital stroke/death rate.

RESULTS

We identified 4260 patients who underwent tfCAS, 3130 patients who underwent TCAR, and 20,012 patients who underwent CEA. Patients were most likely to have minimal disability (mRS, 0-1 [61%]) and least likely to have severe disability (mRS, 5 [1.5%]). Patients most often underwent revascularization in 3 to 14 days (45%). Across all intervention methods, increasing preoperative mRS was associated with higher procedural in-hospital stroke/death (all P < .03), whereas increasing time to intervention was associated with lower stroke/death rates (all P < .01). After adjustment for demographics and comorbidities, undergoing tfCAS was associated with higher stroke/death compared with undergoing CEA (adjusted odds ratio, 1.6; 95% confidence interval, 1.3-1.9; P < .01) or undergoing TCAR (adjusted odds ratio, 1.3; 95% confidence interval, 1.0-1.8; P = .03).

CONCLUSIONS

In patients with preoperative stroke, optimal timing for carotid revascularization varies with stroke severity. Increasing preoperative mRS was associated with higher procedural in-hospital stroke/death rates, whereas increasing time to-intervention was associated with lower stroke/death rates. Overall, patients undergoing CEA were associated with lower in-hospital stroke/deaths. To determine benefit for delayed intervention, these results should be weighed against the risk of recurrent stroke during the interval before intervention.

Thoracic endovascular aortic repair of metachronous thoracic aortic aneurysms following prior infrarenal abdominal aortic aneurysm repair

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) of metachronous thoracic aortic aneurysms (M-TAAs) following previous infrarenal abdominal aortic aneurysm (AAA) repair has been associated with higher spinal cord ischemia (SCI) risk compared with TEVAR of primary thoracic aortic aneurysms (TAAs). However, data on the impact of the type of prior infrarenal aortic repair on outcomes are scarce. In this study, we examined perioperative outcomes and long-term mortality following TEVAR M-TAA compared with primary TEVAR of TAA.

METHODS

We identified all Vascular Quality Initiative (VQI) patients who underwent TEVAR of TAA in the descending thoracic aorta from 2013 to 2022. Only patients undergoing primary TEVAR or TEVAR following infrarenal open (OAR) or endovascular (EVAR) repair were included. We performed univariate analyses to identify differences in baseline and procedural characteristics, and multivariable analyses for perioperative outcomes and 5-year mortality using logistic and Cox regression, respectively.

RESULTS

We included 1493 patients who underwent primary TEVAR (81%) or TEVAR following prior OAR (9.0%) or prior EVAR (9.7%). Compared with primary TEVAR, patients undergoing TEVAR M-TAA were older, more commonly male, white, and had higher rates of hypertension, smoking, and renal dysfunction. Patients with M-TAA were more likely to be asymptomatic and have larger diameters at presentation but were exposed to greater contrast volume and procedural times relative to primary TEVAR patients. Following risk-adjustment, compared with primary TEVAR, TEVAR after prior EVAR was associated with higher perioperative mortality (9.7% vs 3.9%; odds ratio [OR], 5.3; 95% confidence interval [CI], 2.3-12; P < .001) and 5-year mortality (40% vs 24%; hazard ratio [HR], 2.1; 95% CI, 1.4-3.1; P = .001). Specifically, among octogenarians (n = 375; 25%), the perioperative and 5-year mortality differences were even more pronounced (perioperative mortality: 17% vs 8.4%; OR, 6.7; 95% CI, 2.2-21; P = .001; 5-year mortality: 50% vs 27%; HR, 3.0; 95% CI, 1.5-5.7; P = .010). However, in-hospital complications, including SCI (2.6% vs 2.8%; OR, 1.2; 95% CI, 0.33-3.3; P = .77), were not notably different. In contrast, TEVAR after previous OAR was associated with comparable perioperative mortality (4.4% vs 3.9%; OR, 1.2; 95% CI, 0.32-3.8; P = .73), 5-year mortality (28% vs 24%; HR, 1.3; 95% CI, 0.80-2.1; P = .54), and in-hospital complications, including SCI (2.6% vs 0.7%; OR, 0.21; 95% CI, 0.01-1.1; P = .16).

CONCLUSIONS

Patients undergoing TEVAR of M-TAAs after prior EVAR, particularly octogenarians, have higher perioperative and 5-year mortality and therefore, represent a high-risk group. Future efforts should strive to discern the underlying factors leading to these poorer outcomes; meanwhile, these findings emphasize the need for careful patient selection and appropriate preoperative counseling in these high-risk individuals.

Temporal Trends and Determinants of Stroke Risk in Patients With Medically Treated Asymptomatic Carotid Stenosis

BACKGROUND

Effectiveness of carotid procedures (surgery and stenting) in patients with asymptomatic carotid artery stenosis (ACAS) depends on the absolute risk reduction that patients might receive from these procedures. We aimed to quantify the risk of ipsilateral ischemic stroke and examined temporal trends and determinants of these risks in patients with ACAS treated conservatively.

METHODS

We conducted a systematic review from inception to March 9, 2023, of peer-reviewed trials and cohort studies describing ipsilateral ischemic stroke risk in medically treated patients with ACAS of ≥50%. Risk of bias was assessed with an adapted version of the Quality in Prognosis Studies tool. We calculated the annual incidence rates of ipsilateral ischemic stroke. We explored temporal trends and associations of sex and degree of stenosis with ipsilateral ischemic stroke using Poisson metaregression analysis and incidence rate ratios, respectively.

RESULTS

After screening 5915 reports, 73 studies describing ipsilateral ischemic stroke rates of 28 625 patients with midyear of recruitment ranging from 1976 to 2014 were included. The incidence of ipsilateral ischemic stroke was 0.98 (95% CI, 0.93-1.04) per 100 patient-years (median duration of follow-up, 3.3 years). The incidence decreased 24% with every 5 years more recent midyear of recruitment (rate ratio, 0.76 [95% CI, 0.73-0.78]). Incidence rates of ipsilateral ischemic stroke were lower in female patients (rate ratio, 0.74 [95% CI, 0.63-0.87]) and in patients with moderate versus severe stenosis when assessed in cohort studies, with incidence rate ratios of 0.41 ([95% CI, 0.35-0.49] cutoff, 70%) and 0.42 ([95% CI, 0.30-0.59] cutoff, 80%).

CONCLUSIONS

Reported risks of ipsilateral ischemic stroke in patients with ACAS have declined 24% every 5 years from mid-1970s onward, further challenging the routine use of carotid procedures. Risks were lower in female patients and more than twice as high with severe compared with moderate ACAS. Inclusion of these findings in individualized risk assessment can help to determine the benefit of carotid procedures in selected individual patients with ACAS.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42021222940.

Mortality analysis of endovascular aneurysm sealing versus endovascular aneurysm repair

BACKGROUND

Endovascular aneurysm sealing (EVAS), using the Nellix endovascular aneurysm sealing system, has been associated with high reintervention and migration rates. However, prior reports have suggested that EVAS might be related to a lower all-cause mortality compared with endovascular aneurysm repair (EVAR). In the present study, we examined the 5-year all-cause mortality trends after EVAS and EVAR.

METHODS

We compared the 333 EVAS patients in the EVAS-1 Nellix U.S. investigational device exemption trial with 16,497 infrarenal EVAR controls from the Vascular Quality Initiative, treated between 2014 and 2016, after applying the exclusion criteria from the investigational device exemption trial (ie, hemodialysis, creatinine >2.0 mg/dL, rupture). As a secondary analysis, we stratified the patients by aneurysm diameter (<5.5 cm and ≥5.5 cm). We calculated propensity scores after adjusting for demographics, comorbidities, and anatomic characteristics and applied inverse probability weighting to compare the risk-adjusted long-term mortality using Kaplan-Meier and Cox regression analyses.

RESULTS

After weighting, the EVAS group had experienced similar 5-year mortality compared with the controls from the Vascular Quality Initiative (EVAS vs EVAR, 18% vs 14%; hazard ratio [HR], 1.1; 95% confidence interval [CI], 0.71-1.7; P = .70). The subgroup analysis demonstrated that for patients with an aneurysm diameter of <5.5 cm, EVAS was associated with higher 5-year mortality compared with EVAR (19% vs 11%; HR, 2.4; 95% CI, 1.7-4.7; P = .013). In patients with an aneurysm diameter of ≥5.5 cm, EVAS was associated with lower mortality within the first 2 years (2-year mortality: HR, 0.29; 95% CI, 0.13-0.62; P = .002). However, compared with EVAR, EVAS was associated with higher mortality between 2 and 5 years (HR, 1.9; 95% CI, 1.2-3.0; P = .005), with no mortality difference at 5 years (18% vs 17%; HR, 0.82; 95% CI, 0.4-1.4; P = .46).

CONCLUSIONS

Within the overall population, EVAS was associated with similar 5-year mortality compared with EVAR. EVAS was associated with higher mortality for those with small aneurysms (<5.5 cm). For those with larger aneurysms (≥5.5 cm), EVAS was initially associated with lower mortality within the first 2 years, although this advantage was lost thereafter, with higher mortality after 2 years. Future studies are required to evaluate the specific causes of death and to elucidate the potential beneficial mechanism behind sac obliteration that leads to this potential initial survival benefit. This could help guide the development of future grafts with better proximal fixation and sealing that also incorporate sac obliteration.

In-hospital outcomes after carotid endarterectomy for stroke stratified by modified Rankin scale score and time of intervention

OBJECTIVE

Although the benefits of carotid endarterectomy (CEA) for treating symptomatic carotid stenosis are well known, the optimal timing of intervention after acute stroke and whether the optimal timing will vary with preoperative stroke severity has remained unclear. Therefore, we assessed the effect of stroke severity and timing of the intervention on the postoperative outcomes for patients who had undergone CEA for stroke.

METHODS

We identified all patients in the Vascular Quality Initiative who had undergone CEA from 2012 to 2020 for prior stroke. The patients were stratified using the preoperative modified Rankin scale score (mRS score, 0-5) and time to CEA after stroke onset (≤2 days, 3-14 days, 15-90 days, 91-180 days). After univariate comparisons, the patients were stratified into the following mRS cohorts for further analysis: 0 to 1, 2, 3 to 4, and 5. The primary outcome was in-hospital stroke/death.

RESULTS

We identified 15,601 patients, of whom 30% had had an mRS score of 0, 34% an mRS score of 1, 17% an mRS score of 2, 11% an mRS score of 3, 8% an mRS score of 4, and 1% an mRS score of 5. Overall, 9.3% of the patients had undergone CEA within ≤2 days, 46% within 3 to 14 days, 36% in 15 to 90 days, and 8.4% within 90 to 180 days. A decreasing mRS score and an increasing time to CEA were associated with lower rates of perioperative stroke/death (P_trend < .01). After risk adjustment, with CEA at 3 to 14 days as the comparator group, the mRS score 0 to 1 group had had a higher incidence of stroke/death after CEA within ≤2 days (3.6% vs 2.0%; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2-2.7). The mRS score 2 group had had a similar incidence of stroke/death after CEA within ≤2 days (4.4% vs 3.9%; OR, 1.2; 95% CI, 0.6-2.3) but a lower incidence after CEA at 15 to 90 days (2.1% vs 3.9%; OR 0.5; 95% CI, 0.3-0.96). The mRS score 3 to 4 group had had a higher incidence of stroke/death after CEA within ≤2 days (8.0% vs 3.8%; OR, 2.4; 95% CI, 1.5-3.9) but a similar incidence of stroke/death after CEA at 15 to 90 days (3.0% vs 3.8%; OR, 0.8; 95% CI, 0.5-1.3). For the mRS score 5 group, the stroke/death rates were ≥6.5% across all the time to CEA groups. However, the low sample size limited meaningful comparisons.

CONCLUSIONS

Patients with minimal disability after stroke (mRS score, 0-1) seemed to benefit from CEA within 3 to 14 days. However, those with severe disability (mRS score 5) have a very high risk from CEA at any time point given the poor outcomes. In contrast to the current guidelines, patients with mild disability (mRS score 2) could benefit from delaying CEA to 15 to 90 days, and those with moderate disability (mRS score 3-4) might benefit from CEA within 3 to 90 days given the acceptable in-hospital outcomes. These data should be considered within the context of the clinical situation in the weeks after index event to determine the net benefit of delayed CEA.

Outcomes after transcarotid artery revascularization stratified by preprocedural symptom status

OBJECTIVE

Previous studies on carotid endarterectomy and transfemoral carotid artery stenting demonstrated that perioperative outcomes differed according to preoperative neurologic injury severity, but this has not been assessed in transcarotid artery revascularization (TCAR). In this study, we examined contemporary perioperative outcomes in patients who underwent TCAR stratified by specific preprocedural symptom status.

METHODS

Patients who underwent TCAR between 2016 and 2021 in the Vascular Quality Initiative were included. We stratified patients into the following groups based on preprocedural symptoms: asymptomatic, recent (symptoms occurring <180 days before TCAR) ocular transient ischemic attack (TIA), recent hemispheric TIA, recent stroke, or formerly symptomatic (symptoms occurring >180 days before TCAR). First, we used trend tests to assess outcomes in asymptomatic patients versus those with an increasing severity of recent neurologic injury (recent ocular TIA vs recent hemispheric TIA vs recent stroke). Then, we compared outcomes between asymptomatic and formerly symptomatic patients. Our primary outcome was in-hospital stroke/death rates. Multivariable logistic regression was used to adjust for demographics and comorbidities across groups.

RESULTS

We identified 18,477 patients undergoing TCAR, of whom 62.0% were asymptomatic, 3.2% had a recent ocular TIA, 7.6a % had recent hemispheric TIA, 18.0% had a recent stroke, and 9.2% were formerly symptomatic. In patients with recent symptoms, we observed higher rates of stroke/death with increasing neurologic injury severity: asymptomatic 1.1% versus recent ocular TIA 0.8% versus recent hemispheric TIA 2.1% versus recent stroke 3.1% (Ptrend < .01). In formerly symptomatic patients, the rate of stroke/death was higher compared with asymptomatic patients, but this difference was not statistically significant (1.7% vs 1.1%; P = .06). After risk adjustment, compared with asymptomatic patients, there was a higher odds of stroke/death in patients with a recent stroke (odds ratio [OR], 2.8; 95% confidence interval [CI], 2.1-3.7; P < .01), a recent hemispheric TIA (OR, 2.0; 95% CI, 1.3-3.0; P < .01), and former symptoms (OR, 1.6; 95% CI, 1.1-2.5; P = .02), but there was no difference in stroke/death rates in patients with a recent ocular TIA (OR, 0.9; 95% CI, 0.4-2.2; P = .78).

CONCLUSIONS

After TCAR, compared with asymptomatic status, a recent stroke and a recent hemispheric TIA were associated with higher stroke/death rates, whereas a recent ocular TIA was associated with similar stroke/death rates. In addition, a formerly symptomatic status was associated with higher stroke/death rates compared with an asymptomatic status. Overall, our findings suggest that classifying patients undergoing TCAR as symptomatic versus asymptomatic may be an oversimplification and that patients' specific preoperative neurologic symptoms should instead be used in risk assessment and outcome reporting for TCAR.

Outcomes after transfemoral carotid artery stenting stratified by preprocedural symptom status

OBJECTIVE

The available data on outcomes after transfemoral carotid artery stenting (TFCAS) originate from the early experience with TFCAS. Although most previous studies stratified outcomes according to a symptomatic or asymptomatic presentation, they often did not specify the degree of presenting neurologic injury. We previously reported that the outcomes after carotid endarterectomy differed according to neurologic injury severity, the contemporary perioperative outcomes of TFCAS stratified by the specific presenting symptom status are unknown.

METHODS

Patients with data in the Vascular Quality Initiative database who had undergone TFCAS from 2016 to 2020 were included. We stratified patients according to their preprocedural symptom status as asymptomatic, formerly symptomatic (last symptoms >180 days before the procedure), or recently symptomatic (symptoms <180 days before the procedure). The symptoms included stroke, hemispheric transient ischemic attack (TIA), and ocular TIA. We compared the occurrence of in-hospital stroke or death (stroke/death) among the asymptomatic, formerly symptomatic, and specific subtypes of recently symptomatic patients. Multivariable logistic regression models were constructed to adjust for the baseline differences among the groups.

RESULTS

Of the 9807 included patients, 2650 (27%) had had recent stroke, 842 (9%), recent hemispheric TIA, and 360 (4%), recent ocular TIA. In addition, 795 patients (8%) were formerly symptomatic and 5160 (53%) were asymptomatic. The patients with recent stroke had a perioperative stroke/death rate of 5.5%, higher than that of patients with recent hemispheric TIA (2.4%; P < .001) or recent ocular TIA (2.8%; P = .03) and asymptomatic patients (1.4%; P < .001). The stroke/death rate was greater for patients with recent ocular TIA than for asymptomatic patients (2.8% vs 1.4%; P = .04). Formerly symptomatic patients had higher stroke/death rates compared with asymptomatic patients (3.5% vs 1.4%; P < .001). On multivariable-adjusted analysis, recent stroke was associated with higher stroke/death compared with recent hemispheric TIA (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.6-4.3; P < .001) and asymptomatic status (OR, 4.1; 95% CI, 3.0-5.6; P < .001) and demonstrated a trend toward higher stroke/death compared with recent ocular TIA (OR, 2.0; 95% CI, 1.0-3.9; P = .06). Furthermore, asymptomatic status was associated with lower stroke/death compared with formerly symptomatic status (OR, 0.4; 95% CI, 0.2-0.6; P < .001).

CONCLUSIONS

For patients undergoing TFCAS, recent stroke was associated with greater odds of in-hospital stroke/death after TFCAS compared with recent hemispheric TIA. Also, formerly symptomatic status was associated with greater odds of stroke/death compared with asymptomatic status. These findings support further symptom stratification by the degree of the presenting neurologic injury in the preoperative risk assessment.

In-hospital outcomes alone underestimate rates of 30-day major adverse events after carotid artery stenting

OBJECTIVE

Outcome studies using databases collecting only hospital discharge data underestimate morbidity and mortality because of failure to capture postdischarge events. The proportion of postdischarge major adverse events is well characterized in patients undergoing carotid endarterectomy (CEA) but has yet to be characterized after carotid artery stenting (CAS).

METHODS

We retrospectively reviewed all patients undergoing CAS from 2011 to 2017 using the American College of Surgeons National Surgical Quality Improvement Program procedure targeted database to evaluate rates of 30-day major adverse events, stratified by in-hospital and postdischarge occurrences. The primary outcome was 30-day stroke/death. Multivariable analysis using purposeful selection was used to identify independent factors associated with in-hospital, postdischarge, and 30-day stroke/death events.

RESULTS

Of the 899 patients undergoing CAS, reporting of in-hospital outcomes alone would yield a stroke/death rate of 2.7%, substantially underestimating the 30-day stroke/death rate of 4.0%. In fact, 35% of stroke/deaths, 27% of strokes, 73% of deaths, 35% of cardiac events, and 35% of stroke/death/cardiac events occurred after discharge. More postdischarge stroke/death events occurred after treatment of symptomatic compared with asymptomatic patients (47% vs 27%; P < .001). During this same study period, the 30-day stroke/death rate after CEA was 2.6%, with similar proportions of postdischarge strokes (28% vs 27%; P = .51) compared with CAS but lower proportions of postdischarge deaths (55% vs 73%; P < .001). After CAS, patients experiencing postdischarge stroke/death events had a shorter postoperative length of stay compared with patients with in-hospital stroke/death (1 [1-2] vs 5 [3-10] days; P < .001). Chronic obstructive pulmonary disease was independently associated with postdischarge stroke/death (odds ratio [OR], 4.4; 95% confidence interval [CI], 1.2-16; P = .02) after CAS. Nonwhite ethnicity was independently associated with overall 30-day stroke/death (OR, 3.4; 95% CI, 1.4-7.9; P < .01), whereas statin use was associated with not having stroke/death within 30 days (OR, 0.5; 95% CI, 0.2-1.0; P = .049).

CONCLUSIONS

More than one-quarter of perioperative strokes occur following discharge after both CAS and CEA. A higher proportion of postdischarge deaths occur after CAS in symptomatic patients, which may reflect treatment of a population of higher risk patients. Further investigation is needed to elucidate the cause of postdischarge stroke to develop methods to reduce these complications.

Contemporary outcomes after carotid endarterectomy in high-risk anatomic and physiologic patients

OBJECTIVE

Current guidelines state that the acceptable 30-day postoperative stroke/death rate after carotid endarterectomy (CEA) is <3% for asymptomatic patients and <6% for symptomatic patients. The Centers for Medicare and Medicaid Services has identified certain high-risk characteristics used to define patients at highest risk for CEA for whom carotid artery stenting would be reimbursed. We evaluated the impact of the Centers for Medicare and Medicaid Services physiologic and anatomic high-risk criteria on major adverse event rates after CEA in asymptomatic and symptomatic patients.

METHODS

We retrospectively reviewed all patients undergoing CEA from 2011 to 2017 in the American College of Surgeons National Surgical Quality Improvement Program vascular targeted database. Patients with high-risk anatomic or physiologic characteristics were identified by a predefined variable and were compared with normal-risk patients. The primary outcome was 30-day stroke/death, stratified by symptom status.

RESULTS

We identified 25,788 patients undergoing CEA, of whom 60% were treated for asymptomatic carotid disease. Among all patients, high-risk physiology or anatomy was associated with higher rates of 30-day stroke/death compared with normal-risk patients (physiologic risk, 4.6% vs 2.3% [P < .001]; anatomic risk, 3.6% vs 2.3% [P < .001]). Patients who met criteria for high-risk physiology or anatomy also had higher rates of cardiac events (physiologic risk, 3.1% vs 1.6% [P < .001]; anatomic risk, 2.3% vs 1.6% [P < .01]), but only patients with high-risk anatomy had higher rates of cranial nerve injury (physiologic risk, 2.4% vs 2.5% [P = .81]; anatomic risk, 4.3% vs 2.5% [P < .001]). Asymptomatic patients with high-risk physiology or anatomy had higher rates of 30-day stroke/death, especially in the physiologic high-risk group (physiologic risk, 4.7% vs 1.5% [P < .001]; anatomic risk, 2.6% vs 1.5% [P < .01]), compared with normal-risk patients. However, among symptomatic patients, differences in stroke/death were seen only with high-risk anatomic patients and not with high-risk physiologic patients (physiologic risk, 4.6% vs 3.4% [P = .12]; anatomic risk, 4.8% vs 3.4% [P = .01]).

CONCLUSIONS

As currently selected, contemporary real-world outcomes after CEA in asymptomatic carotid disease patients meeting high-risk physiologic criteria show an unacceptably high 30-day stroke/death rate, well above the 3% threshold. These results suggest the need for better selection of patients and preoperative optimization before elective CEA.

The use of a neural network for studying the relationship between air pollution and asthma-related emergency room visits

To establish the relationship between air pollution levels and bronchial asthma-associated emergency room (ER) visits, we adapted artificial network technology to conduct this study which focused on three different pollutants, sulphur dioxide, nitrogen oxide and ozone. The study population was comprised of adults presenting to the emergency room of a large metropolitan hospital in Israel during a 3-month period with acute exacerbation of bronchial asthma and who had a past history of intermittent airway disease compatible with bronchial asthma. The range of mean daily pollutants levels for the whole period were: O3 = 15-26 micrograms m-3, NOx = 36-108 micrograms m-3, NO = 16-70 micrograms m-3, and SO2 = 11-32 micrograms m-3. The data sets were composed of input air pollution levels and output ER visits. The first 126 data sets used for the training phase showed that maximal ER visits were mainly associated with the highest cumulative values of air pollution and mostly with nitrogen oxide. In phase two, an attempt was made to predict ER visits based on air pollution level in 49 data sets. The study findings demonstrated that ordinary network technology can be used for learning the effect of air pollution ER visits and, although limited in accuracy, to also predict future ER visits.

"Why don't you do it properly?" Young women who self-injure

Analysis of interviews with four self-injuring young women suggests that the meaning of self-injury is not the same as the meaning of attempted suicide, and that the two acts are related in the sense that self-injury is an adaptive alternative to suicide. The function of self-injury as a communicative act and the extent to which self-injurers can control their actions are also discussed. It is suggested that, within the context of self-injury as survival, issues of communication and control do not have the significance that they are frequently supposed to have. Implications for clinical practice are discussed.

Diseases with ocular and dental abnormalities

This report gives an overall view on the aspect of numerous diseases and symptom complexes affecting both eyes and teeth. The knowledge of these disorders enables the ophthalmologist to suspect and recognize certain types of dental malformation and enables the dentist to discover certain eye defects. Moreover, it is important that clinicians be aware that simultaneous eye and tooth defects may be the indication of possible disturbances in other, apparently unrelated, organs or systems. Because such disorders are frequently hereditary conditions, their early detection will aid in the diagnosis and treatment of other affected family members. This may also help the parents to cope with the disease and be of benefit to the infants because a cure may be forthcoming.

Trauma as a possible etiologic factor in maxillary canine impaction

A chain of events in the development of the dentition following trauma is described. Shortening of the root of the lateral incisor or displacement of the tooth bud, both as a sequel to trauma, may affect the path of eruption of the adjacent canine after dental injury. Special attention should be paid to the further development and eruption of the directly and indirectly affected teeth.