Validation of the Norwegian survival prediction model in trauma (NORMIT) in Swedish trauma populations.

BACKGROUND: Trauma survival prediction models can be used for quality assessment in trauma populations. The Norwegian survival prediction model in trauma (NORMIT) has been updated recently and validated internally (NORMIT 2). The aim of this observational study was to compare the accuracy of NORMIT 1 and 2 in two Swedish trauma populations. METHODS: Adult patients registered in the national trauma registry during 2014-2016 were eligible for inclusion. The study populations comprised the total national trauma (NT) population, and a subpopulation of patients admitted to a single level I trauma centre (TC). The primary outcome was 30-day mortality. Model validation included receiver operating characteristic (ROC) curve analysis and GiViTI calibration belts. The calibration was also assessed in subgroups of severely injured patients (New Injury Severity Score (NISS) over 15). RESULTS: A total of 26 504 patients were included. Some 18·7 per cent of patients in the NT population and 2·6 per cent in the TC subpopulation were excluded owing to missing data, leaving 21 554 and 3972 respectively for analysis. NORMIT 1 and 2 showed excellent ability to distinguish between survivors and non-survivors in both populations, but poor agreement between predicted and observed outcome in the NT population with overestimation of survival, including in the subgroup with NISS over 15. In the TC subpopulation, NORMIT 1 underestimated survival irrespective of injury severity, but NORMIT 2 showed good calibration both in the total subpopulation and the subgroup with NISS over 15. CONCLUSION: NORMIT 2 is well suited to predict survival in a Swedish trauma centre population, irrespective of injury severity. Both NORMIT 1 and 2 performed poorly in a more heterogeneous national population of injured patients.

ANTECEDENTES: Los modelos de predicción de supervivencia en los traumatismos pueden ser utilizados para la evaluación de la calidad en las poblaciones con traumatismos. Recientemente, el modelo noruego de predicción de supervivencia en traumatismos (NORMIT) se ha actualizado y validado internamente (NORMIT 2). El objetivo de este estudio observacional fue comparar la precisión de los modelos NORMIT 1 y 2 en dos poblaciones suecas con traumatismos. MÉTODOS: Pacientes adultos registrados en el registro nacional de traumatismos durante 2014-2016 fueron elegibles para el estudio. Las poblaciones de estudio eran: (1) la población total nacional de traumatismos (national trauma, NT) y (2) una subpoblación de pacientes ingresados en un único centro de trauma de nivel I (trauma centre, TC). El resultado primario fue la mortalidad a los 30 días. La validación del modelo incluyó curvas de características operativas del receptor y cinturones GiViTI de calibración. La calibración también se evaluó en subgrupos de pacientes con lesiones graves (New Injury Severity Score, NISS >15). RESULTADOS: Se incluyeron un total de 26.504 pacientes. La exclusión por falta de datos fue del 18,7% en la población NT (n = 21.554) y del 2,6% en la población TC (n = 3.972). Los modelos NORMIT 1 y 2 mostraron una habilidad excelente para distinguir entre supervivientes y no supervivientes en ambas poblaciones, pero con un grado de acuerdo pobre entre el resultado predicho y el observado en la población NT, con sobreestimación de la supervivencia incluido el subgrupo de NISS >15. En la subpoblación TC, NORMIT 1 subestimó la supervivencia independientemente de la gravedad de la lesión, pero NORMIT 2 mostró una buena calibración tanto en la subpoblación total, como en el subgrupo NISS >15. CONCLUSIÓN: El modelo NORMIT 2 es muy apropiado para predecir la supervivencia en la población de un centro de traumatismos sueco independientemente de la gravedad de la lesión. Los modelos tanto NORMIT 1 como NORMIT 2 funcionan mal en una población de traumatismos nacional más heterogenea.

Cost-effectiveness of Screening for Abdominal Aortic Aneurysm in Combination with Medical Intervention in Patients with Small Aneurysms.

OBJECTIVES: Screening for abdominal aortic aneurysm (AAA) among 65 year old men has been proven cost-effective, but nowadays is conducted partly under new conditions. The prevalence of AAA has decreased, and endovascular aneurysm repair (EVAR) has become the predominant surgical method for AAA repair in many centers. At the Malmö Vascular Center pharmacological secondary prevention with statins, antiplatelet therapy, and blood pressure reduction is initiated and given to all patients with AAA. This study evaluates the cost-effectiveness of AAA screening under the above mentioned conditions. METHODS: This was a Markov cohort simulation. A total of 4,300 65 year old men were invited to annual AAA screening; the attendance rate was 78.3% and AAA prevalence was 1.8%. A Markov model with 11 health states was used to evaluate cost-effectiveness of AAA screening. Background data on rupture risks, costs, and effectiveness of surgical interventions were obtained from the participating unit, the national Swedvasc Registry, and from the scientific literature. RESULTS: The additional costs of the screening strategy compared with no screening were €169 per person and year. The incremental health gain per subject in the screened cohort was 0.011 additional quality adjusted life years (QALYs), corresponding to an incremental cost-effectiveness ratio (ICER) of €15710 per QALY. Assuming a 10% reduction of all cause mortality, the incremental cost of screening was €175 per person and year. The gain per subject in the screened cohort was 0.013 additional QALYs, corresponding to an ICER of €13922 per QALY CONCLUSIONS: AAA screening remains cost-effective according to both the Swedish recommendations and the UK National Institute for Health and Care Excellence recommendations in the new era of lower AAA prevalence, EVAR as the predominant surgical method, and secondary prevention for all AAA patients.

Invasive treatment for infrainguinal claudication has satisfactory 1 year outcome in three out of four patients: a population-based analysis from Swedvasc.

OBJECTIVES: In spite of recommendations advocating conservative best medical treatment, many patients with infrainguinal intermittent claudication (IC) are treated by invasive open and endovascular methods. This study aims to evaluate the incidence and 1-year results of all such treatments during 2009 in Sweden. METHODS: The design was a one-year follow-up through the Swedish Vascular Registry (Swedvasc) of all 775 patients from the Swedish population of 10 million inhabitants in whom 843 invasive infrainguinal procedures (796 index procedures and 47 secondary procedures) were performed for IC in 2009. Index procedures were open surgery in 290 (37%) patients, bilateral in nine cases, giving a total of 299 limbs, endovascular treatment in 447 (58%) patients, bilateral in 10, giving a total of 457 limbs, and hybrid treatment in 38 (5%) patients, bilateral in two cases, giving a total of 40 limbs. Data were analysed both with regard to the number of patients (775) and the number of procedures (843). Clinical outcome was calculated from patient-reported leg function (unchanged, improved, deteriorated) and whether amputation had been necessary or death had occurred. Patent reconstruction at 1 year was also counted as improvement. RESULTS: Improvement at 1 year was seen in 567 (73.2%) patients, (225 [77.6%] in the open surgery group, 320 [71.6%] in the endovascular treatment group, and 22 [57.9%] in the hybrid treatment group). No significant difference was found between the open surgery and endovascular treatment groups comprising 737/775 patients (p = .350). Hybrid treatment gave significantly worse results (p = .046). Fifty-seven (7.3%) patients reported unchanged limb function and 32 (4.1%) patients reported deterioration. Within 30 days two patients died and one patient underwent amputation. Within 1 year 10 patients underwent 11 amputations: five (1.7%) in the open surgery group, three (0.6%) in the endovascular treatment group, and two (7.5%) in the hybrid treatment group; one underwent bilateral amputation (p = .07). Twenty-two patients died: 10 (3.4%) in the open surgery group, 12 (2.7%) in the endovascular treatment group and none in the hybrid treatment group (p = .465). CONCLUSIONS: Reported improvement at 1 year was 73.2% in patients invasively treated for infrainguinal IC. Patients reporting an unchanged or deteriorated clinical state are a considerable clinical challenge. Further studies to determine whether or not invasive treatment of infrainguinal IC is appropriate are justified.

Editor's choice - Safety of carotid endarterectomy after intravenous thrombolysis for acute ischaemic stroke: a case-controlled multicentre registry study.

OBJECTIVE: Few studies have been published on the safety of carotid endarterectomy (CEA) after intravenous thrombolysis (IVT). Registry reports have been recommended in order to gather large study groups. DESIGN: A retrospective, registry based, case controlled study on prospectively gathered data from Sweden, the capital region of Finland, and from Denmark, including 30 days of follow up. METHODS: The study group was a consecutive series of 5526 patients who had CEA for symptomatic carotid artery stenosis during a 4.5 year period. Among these, 202 (4%) had IVT prior to surgery, including 117 having CEA within 14 days, and 59 within 7 days of thrombolysis. IVT as well as CEA were performed following established guidelines. The median time from index symptom to CEA was 12 days (range 0-130, IQR 7-21). RESULTS: The 30 day combined stroke and death rate was 3.5% (95% CI 1.69-6.99) for those having IVT + CEA, 4.1% (95% CI 3.46-4.39) for those having CEA without previous IVT (odds ratio 0.84 [95% CI 0.39-1.81]), 3.4% (95% CI 1.33-8.39) for those having IVT + CEA within 14 days, and 5.1% (95% CI 1.74-13.91) for those having IVT + CEA within 7 days. CONCLUSION: Data on the time from symptoms to CEA in patients not having IVT, Rankin score, degree of stenosis, and cerebral imaging were not available. Despite its weaknesses, this study reasserts that CEA can be performed within the recommended 2 weeks of the onset of symptoms and IVT without increasing the risk of peri-operative stroke or death. Centres and vascular registries are recommended to continue monitoring changes in patient characteristics, lead times, and major complications after CEA in general, with a special focus on those who have undergone a prior thrombolysis.

Editor's Choice: Contemporary treatment of popliteal artery aneurysm in eight countries: A Report from the Vascunet collaboration of registries.

OBJECTIVES: To study contemporary popliteal artery aneurysm (PA) repair. METHODS: Vascunet is a collaboration of population-based registries in 10 countries: eight had data on PA repair (Australia, Finland, Hungary, Iceland, New Zealand, Norway, Sweden, and Switzerland). RESULTS: From January 2009 until June 2012, 1,471 PA repairs were registered. There were 9.59 operations per million person years, varying from 3.4 in Hungary to 17.6 in Sweden. Median age was 70 years, ranging from 66 years in Switzerland and Iceland to 74 years in Australia and New Zealand; 95.6% were men and 44% were active smokers. Elective surgery dominated, comprising 72% of all cases, but only 26.2% in Hungary and 39.7% in Finland, (p < .0001). The proportion of endovascular PA repair was 22.2%, varying from 34.7% in Australia, to zero in Switzerland, Finland, and Iceland (p < .0001). Endovascular repair was performed in 12.2% of patients with acute thrombosis and 24.1% of elective cases (p < .0001). A vein graft was used in 87.2% of open repairs, a synthetic or composite graft in 12.7%. Follow-up was until discharge or 30 days. Amputation rate was 2.0% overall: 6.5% after acute thrombosis, 1.0% after endovascular, 1.8% after open repair, and 26.3% after hybrid repair (p < .0001). Mortality was 0.7% overall: 0.1% after elective repair, 1.6% after acute thrombosis, and 11.1% after rupture. CONCLUSIONS: Great variability between countries in incidence of operations, indications for surgery, and choice of surgical technique was found, possibly a result of surgical tradition rather than differences in case mix. Comparative studies with longer follow-up data are warranted.

Variation in clinical practice in carotid surgery in nine countries 2005-2010. Lessons from VASCUNET and recommendations for the future of national clinical audit.

OBJECTIVES: The aim of the study was to analyse variation in carotid surgical practice, results and effectiveness in nine countries. PATIENTS AND METHODS: A total of 48,185 carotid endarterectomies (CEAs) and 4602 carotid artery stenting (CAS) procedures were included in the comparison. A theoretical effectiveness of CEA provision for each country was estimated. RESULTS: 92.6% of the CEAs were performed according to the inclusion criteria based on the current European recommendations and had a theoretical benefit for the patient. The indication for surgery was symptomatic stenosis in 60.1% and this proportion varied between 31.4% in Italy and 100% in Denmark. The overall combined stroke and death rate in symptomatic patients was 2.3%. This varied between rates of 0.9% in Italy and 3.8% in Norway. The overall combined stroke and death rate in asymptomatic patients was 0.9%. It was lowest in Italy at 0.5%, and highest in Sweden at 2.7%. We estimated that the stroke prevention rate per 1000 CEAs varied from 72.9 in Italy to 130.8 in Denmark. CONCLUSIONS: There is significant variation in clinical practice across the participating countries. The theoretical stroke prevention potential of CEA seems to vary between participating countries due to differences in the inclusion criteria.

International variations in infrainguinal bypass surgery - a VASCUNET report.

OBJECTIVES: To compare practice in lower limb bypass surgery in nine countries. DESIGN: A prospective study amalgamating and analysing data from national and regional vascular registries. METHODS: A table of data fields and definitions was agreed by all member countries of the Vascunet Collaboration. Data from January 2005 to December 2009 was submitted to a central database. RESULTS: 32,084 cases of infrainguinal bypass (IIB) in nine countries were analysed. Procedures per 100,000 population varied between 2.3 in the UK and 24.6 in Finland. The proportion of women varied from 25% to 43.5%. The median age for all countries was 70 for men and 76 for women. Hungary treated the youngest patients. IIB was performed for claudication for between 15.7% and 40.8% of all procedures. Vein grafts were used in patients operated on for claudication (52.9%), for rest pain (66.7%) and tissue loss (74.1%). Italy had the highest use of synthetic grafts. Among claudicants 45% of bypasses were performed to the below knee popliteal artery or more distally. Graft patency at 30 days varied between 86% and 99%. CONCLUSIONS: Significant variations in practice between countries were demonstrated. These results should be interpreted alongside the known limitations of such registry data with respect to quality and completeness of the data. Variation in data completeness and data validation between countries needs to be improved for useful international comparison of outcomes.

Treatment of abdominal aortic aneurysm in nine countries 2005-2009: a vascunet report.

OBJECTIVES: To study contemporary treatment and outcome of abdominal aortic aneurysm (AAA) repair in nine countries. DESIGN AND METHODS: Data on primary AAA repairs 2005-2009 were amalgamated from national and regional vascular registries in Australia, Denmark, Finland, Hungary, Italy, Norway, Sweden, Switzerland and the UK. Primary outcome was in-hospital or 30-day mortality. Multivariate logistic regression was used to assess case-mix. RESULTS: 31,427 intact AAA repairs were identified, mean age 72.6 years (95% CI 72.5-72.7). The rate of octogenarians and use of endovascular repair (EVAR) increased over time (p < 0.001). EVAR varied between countries from 14.7% (Finland) to 56.0% (Australia). Overall perioperative mortality after intact AAA repair was 2.8% (2.6-3.0) and was stable over time. The perioperative mortality rate varied from 1.6% (1.3-1.8) in Italy to 4.1% (2.4-7.0) in Finland. Increasing age, open repair and presence of comorbidities were associated with outcome. 7040 ruptured AAA repairs were identified, mean age 73.8 (73.6-74.0). The overall perioperative mortality was 31.6% (30.6-32.8), and decreased over time (p = 0.004). CONCLUSIONS: The rate of AAA repair in octogenarians as well as EVAR increased over time. Perioperative outcome after intact AAA repair was stable over time, but improved after ruptured repair. Geographical differences in treatment of AAA remain.

External validation of the Swedvasc registry: a first-time individual cross-matching with the unique personal identity number.

OBJECTIVE: To study external validity of the Swedvasc registry concerning numbers of procedures and mortality. MATERIALS AND METHODS: Vascular registry data for carotid, infrainguinal bypass and aortic aneurysm (AAA) procedures were compared to the Swedish Hospital Discharge Register (SHDR) data, and the National Population Registry (for mortality) by matching every individual patient using the unique personal identity numbers (PINs). The time-period studied was 2000-2004 (5 years) for carotid and infrainguinal procedures. A separate analysis was performed for AAA-surgery in 2006. RESULTS: The external validity for carotid, infrainguinal bypass and AAA repair was 93.4%, 93.0% and 93.1%, respectively. The 30-day mortality was 0.86% after carotid and 2.9% after infrainguinal bypass procedures. Mortality was 2.6% after planned and 25.9% after unplanned AAA repair. Although there was a general trend towards inferior outcomes after procedures not registered in the Swedvasc, those procedures were so few that in none of the analyses did the inclusion of non-registered procedures affect general outcomes significantly. Combining data from both registries, the incidence for carotid, infrainguinal bypass and AAA procedures was 7.8, 15.2 and 13.6 per 100,000 person-years, respectively. In the hospital-specific analysis for 2006 it was shown that the non-registered procedures for AAA were localized to one non-compliant county hospital, and small district hospitals not performing elective AAA-surgery but only rare emergency operations. CONCLUSION: The external and internal validity of the Swedvasc registry allows to confidently assess volumes of, and mortality after, vascular surgery in Sweden.

Time-trends in vascular access surgery in Sweden 1987-2006.

OBJECTIVE: To study time-trends in vascular access surgery. DESIGN: Prospectively registered data. MATERIAL AND METHODS: The Swedish vascular registry (Swedvasc) was searched for haemodialysis access operations (HAO) 1987-2006. RESULTS: 12,342 open and endovascular operations were identified. Eighty-five percent of HAO 2004-2006 were reported to the registry. The median age of patients having their first HAO increased from 56 to 68 during the first decade (p<0.0001), then remained stable. The frequency of diabetes increased from 12% in 1987 to 32% in 2006 (p<0.0001). The percentage of first HAO of total workload decreased from 76% to 48%. The percentage of first HAO performed as vein fistulas remained unchanged. The number of patients recorded for ten or more previous HAO increased over time. Percutaneous angioplasties increased during the last decade. Of 4706 patients operated on with primary radiocephalic AV-fistulas, 2933 (62%) were operated only once. Analysis of 3739 subsequent operations in 1773 patients disclosed that at the tenth operation vein was still used in 54%. With an increasing number of operations, arterial inflow shifted towards a more proximal position. CONCLUSIONS: Over time, the patients undergoing HAO became older and more often diabetic, reoperations increased. Despite these circumstances, vascular surgeons perform AV-fistulas without grafts in most patients.

Volume versus outcome when treating abdominal aortic aneurysm electively--is there evidence to centralise?

AIM: To identify evidence for the minimum annual case load of open repairs of abdominal aortic aneurysms compatible with an acceptable perioperative mortality rate. METHOD: A PubMed search resulted in 137 references, sixteen articles with original data on volume and mortality not older than ten years were identified and selected for review. RESULT: Three studies found no volume-mortality relationship when controlled for age, sex and medical risk. Six studies verified volume thresholds of 20 procedures per year or more. In seven studies hospital volumes of 7-17 elective abdominal aortic aneurysm (AAA) repairs per year were sufficient to reach a mortality rate of a national average or similar to that of higher volume centres. No studies were published on the minimum annual case-load of EndoVascular Aneurysm Repair (EVAR), or of a combination of EVAR and open repair. CONCLUSION: Recent studies in North America and in Europe indicate that 10-15 procedures annually can be sufficient to safely perform open AAA repairs. Centres regularly performing less should consider referral. Continuous monitoring and audit of risk-adjusted perioperative mortality rates should be practiced in all centres.

Invasive treatment for renovascular disease. A twenty year experience from a population based registry.

AIM: To analyze time trends in invasive treatment of renovascular disease in one country. METHODS: Data have been analyzed from registrations in the Swedish Vascular Registry. RESULTS: Invasive treatment for renovascular disease contributes around 1% of all vascular surgery within the Swedish Vascular Registry. Over the twenty-year period 1987-2006 the population-based frequency of invasive treatment for renovascular disease has increased; 1 597 procedures have been registered with an increase over time. The age of the treated patients has increased over the period (P<0.001). There has been a shift from open to endovascular procedure and from isolated percutaneous transluminal renal angioplasty (PTRA) to PTRA combined with a stent. Complications and mortality are significantly higher in patients undergoing open reconstruction (P<0.01). One year follow-up is incomplete and long-term results are therefore not possible to evaluate through registry-data only. CONCLUSION: Using nation-wide registry data it is possible to analyze time-trends also concerning rare diseases or interventions. The changing pattern toward endovascular treatment of renovascular disease is obvious. Follow-up data at one year are incomplete.

Treatment of aortic aneurysms registered in Swedvasc: Development reflected in a national vascular registry with an almost 100% coverage.

Swedvasc is a registry for vascular surgical procedures, both open and endovascular. It was started in 1987 and since 1994 the whole population of Sweden is covered, at present around 10 million inhabitants. In a recent external validation, it was found to be highly accurate with abdominal aortic aneurysm surgery correctly reported in >96%. In this paper various factors explaining the almost 100% coverage are discussed, one important being that the registry has been developed and maintained within the profession of vascular surgery and not dictated by authorities. Another factor of importance is the possibility to use data in various research projects and so far 15 PhD theses have used Swedvasc data. To exemplify the practical use of the registry, the treatment of abdominal aortic aneurysms is scrutinized and among the various complications abdominal compartment syndrome is analyzed. Several significant temporal changes have been observed over the almost 25 years of Swedvasc: increasing use of endovascular surgery, treatment of aneurysms detected by screening , decreasing treatment for rupture, improved outcome, increasing treatment of older patients and patients with comorbid conditions. In conclusion, a high quality national vascular registry can be valid with high compliance and can be used to study population-based development of treatment and outcome. It can also be used to perform international comparisons with other registries, thereby getting an indication of the quality of care.

Implicit discount rates of vascular surgeons in the management of abdominal aortic aneurysms.

A growing empirical literature has investigated attitudes towards discounting of health benefits with regard to social choices of life-saving and health-improving measures and individuals' time preferences for the management of their own health. In this study, the authors elicited the time preferences of vascular surgeons in the context of management of small abdominal aortic aneurysms, for which the choice between early elective surgery and watchful waiting is not straightforward. They interviewed 25 of a random sample of 30 Swedish vascular surgeons. Considerable variation in the time preferences was found in the choices between watchful waiting and surgical intervention among the otherwise very homogeneous group of surgeons. The discount rates derived ranged from 5.3% to 19.4%. The median discount rate (10.4%) is similar to those usually reported for social choices concerning life-saving measures. The surgeons who were employed in university hospitals had higher discount rates than did their colleagues in county and district hospitals.

[Strategies in treatment of critical leg ischemia. An approach to the solution with decision trees]. / Strategien bei der Behandlung von kritischer Gliedmassenischämie. Ein Lösungsansatz mit Entscheidungsbäumen.

In critical leg ischemia the main treatment options are reconstructive vascular surgery and primary amputation but in some cases conservative treatment can be considered. The choice between the alternatives is difficult as a large number of factors must be considered. Among these are significant complication rates, reoperation rates and perioperative mortality as well as medical risk-factors. This paper demonstrates how formal decision analysis using special computer software can contribute by structuring of the decision situation and by quantification of risks and gains. Important is also the possibility of sensitivity analysis, i.e. to examine the effect of varying values of pertinent variables. The explicit structure and the quantification makes a formal decision analysis open for critique, discussion and improvement. This is a distinct advantage over the usual spontaneous clinical decision making.

Staged reconstruction of hypospadias with chordee: outcome and costs.

One-hundred-and-forty patients with hypospadias and chordee were reviewed from the points of view of surgical results and hospital costs. Ninety cases constituted a historical series, and 50 patients a current personal series. All were operated on by Byars' two-staged protocol with release of the chordee followed by urethral reconstruction. Complementary surgery was necessary in a total of 37 instances, particularly in cryptohypospadias with tight chordee and in penoscrotal hypospadias. Increasing personal experience with the operative technique has gradually reduced the need for such procedures. The final results were satisfactory in all but one patient, who has had recurring strictures. The hospital cost for a patient according to basic assumptions was 100,280 SEK (about US$ 14,000). If the time in operating theatre could be shortened by 10 minutes, the stay in hospital reduced by one day, and the complication rate halved, the overall cost would be reduced by 14.3%. Consequently we believe that staged reconstruction remains an attractive alternative in cases of hypospadias with marked curvation of the penis.

[Vascular surgery is steadily increasing in Sweden]. / Kärlkirurgin ökar stadigt i Sverige.

Analysis of the development of arterial surgery between 1980 and 1995, on the basis of questionnaire response and data from the Swedish vascular registry (Swedvasc), showed the annual incidence of elective procedures to have increased from 2,284 to 7,425, and that of emergency procedures from 1,619 to 1,951, the overall annual incidence of operations being 1,068 per million of the population in 1995. There are manifest regional differences in the country as a whole, and the period studied was characterized by relative redistribution of operations from regional to county hospitals. Detailed scrutiny of carotid artery surgery again showed manifest regional differences to exist, but at few hospitals were more than 50 operations performed annually. There was good agreement between Swedvasc data and official operation statistics.

[Intestinal ischemia after abdominal aorta surgery. A dreaded complication surveyed by a combination of different methods]. / Tarmischemi efter bukaortakirurgi. Fruktad komplikation kartlagd med en kombination av olika metoder.

The article consists of a review of findings in previously published reports on intestinal ischaemia after abdominal aortic surgery. In a combined cohort and case-control study of 2,824 patients from the Swedish vascular registry, the incidence of intestinal ischaemia was 2.8%. The independent risk factors identified were preoperative shock, emergency surgery, renal insufficiency, advanced age, operation at a regional hospital, aortabifemoral grafting, ligation of one or both internal iliac arteries, bleeding > 10 litres, and operating and cross-clamping time. Cardinal symptoms were unreliable predictors. Sigmoidoscopy was potentially diagnostic in 95 per cent of cases. In a clinical study of 34 patients, sigmoid colon pHi was highly predictive of ischaemic colitis and other life-threatening complications. In a por-cine model of ischaemic colitis, blood flow in the superior mesenteric artery, colonic pHi and histological mucosal damage were unaffected by dobutamine.

[Significant regional differences in the frequency of vascular surgery]. / Stora regionala skillnader i kärlkirurgisk behandling.

The six health care regions of Sweden were compared with regard to the frequency of vascular surgery for three diagnoses: chronic lower extremity ischaemia, abdominal aorta aneurysm, and carotid stenosis. In 1995, the frequency of intervention for chronic lower extremity ischaemia varied from 26/100,000 of the population in northern Sweden to 68/100,000 in the southern region, the variation being greater for critical limb ischaemia than for intermittent claudication. In the country as a whole, the frequency of abdominal aorta aneurysm surgery increased five-fold from 1987-89 to 1993-95. During 1995, regional figures varied from 4.7 to 8.4 per 100,000 for elective procedures, and from 3.8 to 5.5 per 100,000 for emergency procedures. Overall surgical mortality varied regionally, and emergency surgery mortality differed between regional and county hospitals. Carotid surgery manifested the greatest regional difference in frequency, which was 7-fold greater in the southern than in the northern region, while its overall mean frequency was 6/100,000.