Editor's Choice - International Variations and Sex Disparities in the Treatment of Peripheral Arterial Occlusive Disease: A Report from VASCUNET and the International Consortium of Vascular Registries.

OBJECTIVE: The aim of this study was to determine sex specific differences in the invasive treatment of symptomatic peripheral arterial occlusive disease (PAOD) between member states participating in the VASCUNET and International Consortium of Vascular Registries. METHODS: Data on open surgical revascularisation and peripheral vascular intervention (PVI) of symptomatic PAOD from 2010 to 2017 were collected from population based administrative and registry data from 11 countries. Differences in age, sex, indication, and invasive treatment modality were analysed. RESULTS: Data from 11 countries covering 671 million inhabitants and 1 164 497 hospitalisations (40% women, mean age 72 years, 49% with intermittent claudication, 54% treated with PVI) in Europe (including Russia), North America, Australia, and New Zealand were included. Patient selection and treatment modality varied widely for the proportion of female patients (23% in Portugal and 46% in Sweden), the proportion of patients with claudication (6% in Italy and 69% in Russia), patients' mean age (70 years in the USA and 76 years in Italy), the proportion of octogenarians (8% in Russia and 33% in Sweden), and the proportion of PVI (24% in Russia and 88% in Italy). Numerous differences between females and males were observed in regard to patient age (72 vs. 70 years), the proportion of octogenarians (28% vs. 15%), proportion of patients with claudication (45% vs. 51%), proportion of PVI (57% vs. 51%), and length of hospital stay (7 days vs. 6 days). CONCLUSION: Remarkable differences regarding the proportion of peripheral vascular interventions, patients with claudication, and octogenarians were seen across countries and sexes. Future studies should address the underlying reasons for this, including the impact of national societal guidelines, reimbursement, and differences in health maintenance.

International Variations in Amputation Practice: A VASCUNET Report.

OBJECTIVES: To study international differences in incidence and practice patterns as well as time trends in lower limb amputations related to peripheral arterial disease and/or diabetes mellitus. METHODS: Data on lower limb amputations during 2010-2014 were collected from population based administrative data from countries in Europe and Australasia participating in the VASCUNET collaboration. Amputation rates, time trends, in hospital or 30 day mortality and reimbursement systems were analysed. RESULTS: Data from 12 countries covering 259 million inhabitants in 2014 were included. Individuals aged ≥ 65 years ranged from 12.9% (Slovakia) to 20.7% (Germany) and diabetes prevalence among amputees from 25.7% (Finland) to 74.3% (Slovakia). The mean incidence of major amputation varied between 7.2/100,000 (New Zealand) and 41.4/100,000 (Hungary), with an overall declining time trend with the exception of Slovakia, while minor amputations increased over time. The older age group (≥65 years) was up to 4.9 times more likely to be amputated compared with those younger than 65 years. Reported mortality rates were lowest in Finland (6.3%) and highest in Hungary (20.3%). Countries with a fee for service reimbursement system had a lower incidence of major amputation compared with countries with a population based reimbursement system (14.3/100,000 versus 18.4/100,000, respectively, p < .001). CONCLUSIONS: This international audit showed large geographical differences in major amputation rates, by a factor of almost six, and an overall declining time trend during the 4 year observation of this study. Diabetes prevalence, age distribution, and mortality rates were also found to vary between countries. Despite limitations attributable to registry data, these findings are important, and warrant further research on how to improve limb salvage in different demographic settings.

Meta-Analysis of Genome-Wide Association Studies for Abdominal Aortic Aneurysm Identifies Four New Disease-Specific Risk Loci.

RATIONALE: Abdominal aortic aneurysm (AAA) is a complex disease with both genetic and environmental risk factors. Together, 6 previously identified risk loci only explain a small proportion of the heritability of AAA. OBJECTIVE: To identify additional AAA risk loci using data from all available genome-wide association studies. METHODS AND RESULTS: Through a meta-analysis of 6 genome-wide association study data sets and a validation study totaling 10 204 cases and 107 766 controls, we identified 4 new AAA risk loci: 1q32.3 (SMYD2), 13q12.11 (LINC00540), 20q13.12 (near PCIF1/MMP9/ZNF335), and 21q22.2 (ERG). In various database searches, we observed no new associations between the lead AAA single nucleotide polymorphisms and coronary artery disease, blood pressure, lipids, or diabetes mellitus. Network analyses identified ERG, IL6R, and LDLR as modifiers of MMP9, with a direct interaction between ERG and MMP9. CONCLUSIONS: The 4 new risk loci for AAA seem to be specific for AAA compared with other cardiovascular diseases and related traits suggesting that traditional cardiovascular risk factor management may only have limited value in preventing the progression of aneurysmal disease.

Abdominal aortic aneurysm repair in New Zealand: a validation of the Australasian Vascular Audit.

BACKGROUND: In New Zealand (NZ), there are two major sources of operative data for abdominal aortic aneurysm (AAA) repair: the Australasian Vascular Audit (AVA) and the National Minimum Data Set (NMDS). Since the introduction of the AVA in NZ, there has not been any attempt at the validation of outcome data. The aims of this study were to report the outcomes of AAA repair and validate the AAA data captured by AVA using the NMDS. METHODS: AAA procedures performed in NZ from January 2010 to December 2014 were extracted from the AVA and NMDS. Patients identified from the AVA had their survival status matched to the NMDS. Only primary AAA procedures were included for the analysis, with re-interventions and graft infections excluded. Demographical, risk factors and outcome data were used for validation. RESULTS: The number of patients undergoing primary AAA procedure from AVA and NMDS was 1713 and 2078, respectively. The AVA inpatient mortality for elective and rupture AAA was 1.6 and 32.2%, respectively. The NMDS 30-day mortality from AAA was 2.5 and 31.5%. Overall, 1604 patients were available for matching, and the NMDS correctly reported 98.1% of endovascular aneurysm repair and 94.2% of elective AAA repairs; however, there were major differences in comorbidity reporting between the data sets. CONCLUSION: Both data sets were incomplete, but combining administrative (NMDS) and clinical (AVA) data sets provided a more accurate assessment of mortality figures. More than 80% of AAA repairs are captured by AVA, but further work to improve compliance and comorbidity documentation is required.

Novices may be trained to screen for abdominal aortic aneurysms using ultrasound.

BACKGROUND: Highly trained vascular sonographers make up a significant cost of abdominal aortic aneurysm (AAA) ultrasound screening. However, they are over-trained for this very limited task. Others have reported that health workers (e.g. emergency room staff and nurses) with far less training may be able to perform these scans. The national AAA screening programme in the UK uses staff with limited training. Whether individuals without a health professional qualification could be trained to perform the scan accurately to improve cost-effectiveness is not known. We aimed to investigate whether a short, well-supervised course in ultrasonography could train novices to detect AAA for screening purposes. METHODS: Three novices were trained by an experienced sonographer for 15 days to perform abdominal aortic ultrasound examinations and detect AAA using a portable ultrasound system. The examination included four anterior-posterior aortic measurements: a maximal diameter in the coronal plane and three diameters of the suprarenal, mid and distal infrarenal aorta in the transverse plane. The novices independently scanned 215 subjects following training; experienced sonographers repeated the measurements on the same subject in the same session. Using Bland-Altman plots and CUSUM analysis, the novices' and experienced sonographers' accuracy and efficiency measurements were compared. Factors influencing performance were recorded. RESULTS: The novices measured the maximal coronal aortic diameter accurately, to within 0.46-0.52 cm of the true diameter; 85-97% of their coronal measurements were within 0.5 cm of the assessors; kappa statistic and Bland-Altman plots show a high agreement with the assessor's measurements. However, the novices' measurements of the three diameters in the transverse plane were outside clinically acceptable limits. Assuming a referral policy for a second scan for scans recorded as 'difficult', only one novice missed a 3.13 cm aneurysm.A CUSUM quality improvement analysis demonstrated substantial improvements in the scanning efficiency of the novices with continued scanning experience. CONCLUSION: This study showed that novices could be trained to screen for AAA over 15 days. However, the need for continuing quality improvement is critical, especially in more technically demanding cases. Measuring the maximal infrarenal diameter instead of specific segmental diameters may be more appropriate for AAA screening using novices.

A dedicated dermatology clinic for renal transplant recipients: first 5 years of a New Zealand experience.

AIM: Cancer following organ transplantation is a growing public health concern. We describe the first 5 years' experience of a dedicated dermatology clinic for renal transplant recipients, the first of its type in New Zealand. METHODS: Data from patients seen in the clinic were collected on a nephrology/dermatology database. RESULTS: 86 of 99 transplant recipients had a baseline dermatology assessment. Seventy-one skin cancers (45 squamous, 25 basal cell carcinomas, 1 melanoma) were found in 17 patients. Eighteen of these were an incidental finding at the baseline post-transplant examination of 7 patients: they had not been noted either by the patient or by their nephrologist. A further 44 cancers were found in 13 patients at follow-up examinations in the dedicated clinic. Squamous and basal cell carcinomas received definitive treatment after 26 and 38 days (median) respectively. A brief analysis showed this to be a cost-effective way of diagnosing and treating skin cancer in this cohort of patients. CONCLUSION: The clinic is enabling prompt diagnosis and cost-effective treatment of skin cancers developing in renal transplant recipients and is also identifying significant numbers of pre-existing skin cancers in these patients.

Endovascular aortic repair: can we predict who will not get long-term benefit?

AIM: The aim of this study is to review our endovascular aortic repair (EVAR) experience in Dunedin Public Hospital as well as assessing the applicability of Mount Sinai score and the American Society of Anesthesiologists physical status classification (ASA) in finding which patients will be most likely to benefit from EVAR. METHODS: A retrospective study of 54 patients who had EVAR from 2000 to December 2009 in Dunedin Public Hospital was conducted. Univariate, bivariate and multivariate regressions analyses were used in assessing the data with the occurrence of postoperative complications and mortality as the primary outcome variable. RESULTS: The overall mortality at 30 days was 1.8%. The Mount Sinai score and smoking status were both found to be significant predictors of mortality. DISCUSSION: The Mount Sinai score was a good predictor for mortality as it factors in the patient's comorbidities. This study indicates that smoking status was an important factor and it should be added to long-term risk predicting models.

The impact of bispectral index versus end-tidal anesthetic concentration-guided anesthesia on time to tracheal extubation in fast-track cardiac surgery.

BACKGROUND: Bispectral Index (BIS)-guided anesthesia administration has been reported to reduce the time to tracheal extubation. However, no trials have compared the ability of BIS guidance to promote earlier tracheal extubation relative to guidance by end-tidal anesthetic concentration (ETAC). We hypothesized that BIS-guided anesthesia would result in earlier tracheal extubation compared with ETAC-guided anesthesia in fast-track cardiac surgery patients. METHODS: This study consisted of patients at a single institution who were enrolled in the larger, multicenter BIS or Anesthesia Gas to Reduce Explicit Recall (BAG-RECALL) clinical trial that compared rates of postoperative awareness for patient whose anesthetic was guided by BIS versus ETAC. Patients undergoing cardiac surgery were randomized to BIS (n = 361) or ETAC (n = 362) guided anesthesia. Volatile anesthetic was titrated either to maintain a BIS value of 40 to 60 (BIS group), or an age-adjusted minimum alveolar concentration of 0.7 to 1.3 (ETAC group). In the ETAC group, anesthesiologists were blinded to the BIS values. In this substudy, time to tracheal extubation was compared between groups. Cox regression identified predictors affecting the instantaneous probability of tracheal extubation. RESULTS: Time to tracheal extubation was not significantly different between groups (odds ratio 1.04, 95% confidence interval, 0.88-1.23, P = 0.643). In addition, group assignment did not influence the instantaneous probability of tracheal extubation (P = 0.433). Predictors decreasing the instantaneous probability of tracheal extubation included higher body mass index (P = 0.001), higher logistic EuroSCORE (P = 0.015), complex surgery type (P = 0.034), and surgery completion in the evening (P = 0.03). CONCLUSIONS: Compared with management based on ETAC, anesthetic management based on BIS guidance does not strongly increase the probability of earlier tracheal extubation in patients undergoing fast-track cardiac surgery. The decision to extubate the trachea is more influenced by patient characteristics and perioperative course than the assignment to BIS or ETAC monitoring.

Carotid endarterectomy in octogenarians.

AIM: This study compared the postoperative complication rate between patients age 80 or older to those younger than 80 to determine if older patients were associated with higher risk of complication following carotid endarterectomy. METHOD: Patients who received carotid endarterectomy between January 1997 and December 2005 were identified using the New Zealand Vascular Surgical Audit Registry. Patients were recruited into the two predetermined age groups. Baseline demographics and the complication rates between the two groups were analysed and compared using Chi-squared test. Confounding factors were adjusted using logistic regression. RESULTS: 1682 patients were identified, of which 243 patients (14%) were age 80 or older. Younger patients were more likely to be male (P=0.002) and diabetics (P=0.047) and more patients in the older age group were symptomatic from the carotid stenosis (P=0.014). The overall complication rate was 17.2% and there was no significant difference between the two groups (P=0.268). The overall combined postoperative death, TIAs and stroke rate was 3.3%. The cardiac complication rate was low but higher in octogenarians at 4.5% compared to 2.2% (P=0.035). CONCLUSIONS: Older age does not appear to be associated with higher perioperative complications in carotid endarterectomy.

Development of the Australasian vascular surgical audit.

OBJECTIVE: The purpose of this study was to describe the development of the Australasian Vascular Audit that was created to unify audit activities under the umbrella of the Australian and New Zealand Society for Vascular Surgery as a Web-based application. METHODS: Constitutional change in late 2008 deemed participation in this audit compulsory for Society members. The Web-based application was developed and tested during 2009. Data for all open vascular surgery and for all endovascular procedures are collected at two points in the admission episode: at the time of operation and at discharge, and entered into the application. Data are analyzed to produce risk-adjusted outcomes. An algorithm has been developed to deal with outliers according to natural justice and to comply with the requirements of regulatory bodies. The Audit is protected by legislated privilege and is officially endorsed and indemnified by the Royal Australasian College of Surgeons. Confidentiality of surgeons and patients alike is ensured by a legally protected coding system and computer encryption system. Validation is by a verification process of 5% of members per year who are randomly selected. The application is completely funded by the Society. RESULTS: Data entry commenced on January 1, 2010. Over 40,000 vascular procedures were entered in the first year. The Audit application allows instantaneous on-line access to individual data and to deidentified group data and specific reports. It also allows real-time instantaneous production of log books for vascular trainees. The Audit has already gained recognition in the Australasian public arena during its first year of operation as an important benchmark of correct professional surgical behavior. Compliance has been extremely high in public hospitals but less so in private hospitals such that only 60% of members received a certificate of complete participation at the end of its first year of operation. CONCLUSION: An Internet-based compulsory audit of complete surgical practice is possible to create and be maintained by a society of surgeons with a membership of just over 200. The 60% compliance rate for complete data entry has created an immediate constitutional challenge for the Society. Future challenges are to improve total participation to an acceptable level and to ensure accurate data entry via a robust validation system.

Assessment and management of leg ulcers in the community and an outpatient clinic.

AIM: To compare the assessment and treatment of leg ulcers seen in the community and subsequently reviewed in an outpatient clinic, to the New Zealand Guidelines. METHODS: An observational study including consecutive patients presenting to vascular surgery outpatients with at least one leg ulcer. Outcomes included the clinical descriptions of ulcers, use of an Ankle Brachial Index (ABI) test and compression therapy for mixed and venous ulcers. RESULTS: The study included seventy-six patients. Every ulcer had an adequate clinical description. An ABI investigation was carried out in 9.1% and 66.7% of the patients in the community and outpatient clinic, respectively. Among 31 patients with venous or mixed ulcers in the community, 7 (22.6%) were initiated on compression therapy, and 1 (3.2%) on compression bandaging. Following outpatient clinic appointments, 29 (76.3%) of the 38 patients diagnosed with venous or mixed ulcers were on compression therapy with 20 (52.6%) on compression bandaging. CONCLUSION: There are low rates of ABI measurements and initiation of compression therapy for patients with leg ulcers in the Otago regional community. This may be due to low accessibility to expertise in ABI measurements delaying initiation of compression therapy. Innovations in facilitating ABI investigation in the community and promoting the use of compression therapy are indicated.

How safe is open abdominal aortic aneurysm surgery for octogenarians in New Zealand?

BACKGROUND: Abdominal aortic aneurysm (AAA) is an important cause of mortality for the aged, a group that has been denied surgery in the past for fear of peri-operative mortality. Is this attitude still justified? METHODS: Analysis of prospectively gathered data from a vascular database. RESULTS: 10.9% of all open AAA operations were in patients older than 79 years with an 8% mortality rate compared to 3% for younger patients. For fit elderly patients with ASA scores less than 3, mortality was just under 4%. Renal failure and wound dehiscence were more common in the elderly. CONCLUSION: When endovascular repair is not possible in a fit elderly patient, open surgery can be performed with acceptable results.

Characterization of a porcine model of chronic superficial varicose veins.

OBJECTIVE: Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and characterize a pig-based model of superficial varicose veins. METHODS: Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins. RESULTS: Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening. CONCLUSIONS: The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.

In-hospital mortality of ruptured abdominal aortic aneurysm.

BACKGROUND: New Zealand, like Australia, has a widely dispersed population in towns at long distances from the main centres. We set out to estimate the in-hospital mortality rate for ruptured abdominal aortic aneurysms in New Zealand and identify factors associated with mortality. METHODS: Data were gathered prospectively as part of the Vascular Society of New Zealand's continuous audit programme of all member surgeons. Data collection was validated by random record audit. In-hospital mortality of ruptured abdominal aortic aneurysms, defined as death during hospital admission irrespective of cause, was determined for the period 1993-2005. Along with other performance indicators, differences in outcomes were assessed to take into account the trend over the time period, hospital size and number of non-operative admissions. RESULTS: Of the 740 patients admitted with a mean age of 73.9 +/- 8.5 years, 78% were men and 17.8% were declined an operation. The in-hospital mortality was 48.3% and the operative mortality was 37.8%. With univariate analysis increasing patient age, American Society of Anesthesiology score, hospital size and female sex were predictors of in-hospital mortality. Only age and American Society of Anesthesiology score were independent predictors of operative mortality. Women were less likely to have surgery. CONCLUSION: Over the past 13 years in-hospital mortality of ruptured abdominal aortic aneurysms in New Zealand remained unchanged. In provincial hospitals the operative outcomes were satisfactory, but the reported number not offered surgery was higher.

Mechanical inhibition of angiogenesis at the saphenofemoral junction in the surgical treatment of varicose veins: early results of a blinded randomized controlled trial.

BACKGROUND: Saphenofemoral junction (SFJ) ligation has been a major component of surgical intervention for varicose veins; however, recurrence occurs in as many as 40%. Neovascularization with reconnection of the venous channels at the transected SFJ has been identified as the major cause of this recurrence. This randomized controlled study sought to evaluate mechanical suppression of neovascularization at the SFJ, with the use of a synthetic patch, to prevent recurrence after ligation surgery. METHODS AND RESULTS: A total of 389 limbs (from 292 patients) were randomized into either control (SFJ ligation surgery) or patch (SFJ ligation with polytetrafluoroethylene patch of the transected SFJ) groups. All patients underwent clinical assessment, duplex imaging, and air plethysmography studies preoperatively and at 1, 6, 12, and 36 months postoperatively. The patch consistently halved the recurrence rate to 3 years postoperatively in all clinical subgroups. In those patched SFJs that still developed recurrence, evidence of neovascularization circumventing the polytetrafluoroethylene patch was observed by both ultrasound and histology. CONCLUSIONS: This study demonstrates that use of a polytetrafluoroethylene patch is an effective mechanical suppressant of neovasculogenesis at the SFJ and can be safely used as a strategy to improve long-term outcome of varicose vein surgery.