Opioid Prescribing Habits for Common Arthroscopic Procedures in Opioid Naïve Patients

Background:

With the opioid epidemic and the increasing number of opioid-related deaths, there is growing awareness in the medical community regarding the dangers of opioid overprescription. As a result, there is a willingness among physicians to abandon old norms and adopt new data-driven prescribing practices.

Purpose:

To demonstrate patient-reported consumption data of opioid medications after anterior cruciate ligament (ACL) reconstructions (ACLRs), knee arthroscopies, and rotator cuff repairs to provide data-driven guidelines for prescribing opioids after these procedures.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included in the study were 168 patients who underwent an ACLR, knee arthroscopy, or arthroscopic rotator cuff repair over a 17-month period. Patients were excluded if they had an opioid allergy, had preexisting opioid use, had an acute postoperative complication requiring further surgery, required hospitalization, exhibited drug-seeking behaviors, or were lost to follow-up. Medical records were reviewed to determine the number of opioid pills prescribed and the number of pills taken postoperatively. Prescribing was standardized in that 15 hydrocodone/acetaminophen pills (5/325 mg) were prescribed for all knee arthroscopy procedures and 40 hydrocodone/acetaminophen pills were prescribed for all ACL and rotator cuff procedures. The mean number of pills consumed and percentage of prescribed pills taken were analyzed in association with specific procedures and patient demographics.

Results:

Overall, the mean (±SD) reported opioid consumption overall was 13.5 ± 13.0 pills, with a utilization rate of 45.6% of the prescription. The mean reported opioid consumption for ACLRs, knee arthroscopies, and rotator cuff repairs was 19.1 ± 15.4, 7.2 ± 5.4, and 17.2 ± 14.3 pills, respectively (P < .001). This represented a utilization rate of 48%, 47%, and 41%, respectively.

Conclusion:

This study provides important information regarding opioid utilization after common arthroscopic procedures. For ACLRs, knee arthroscopies, and rotator cuff repairs, by respectively prescribing 20, 10, and 20 pills postoperatively, the amount of unused medications would decrease by 60%, 47%, and 64%, respectively. We recommend prescribing no more than 20, 10, and 20 hydrocodone/acetaminophen pills (5/325 mg) for ACLRs, knee arthroscopies, and arthroscopic rotator cuff repairs, respectively.

Editor's Choice - Re-interventions After Repair of Ruptured Abdominal Aortic Aneurysm: A Report From the IMPROVE Randomised Trial

OBJECTIVE/BACKGROUND

The aim was to describe the re-interventions after endovascular and open repair of rupture, and investigate whether these were associated with aortic morphology.

METHODS

In total, 502 patients from the IMPROVE randomised trial (ISRCTN48334791) with repair of rupture were followed-up for re-interventions for at least 3 years. Pre-operative aortic morphology was assessed in a core laboratory. Re-interventions were described by time (0-90 days, 3 months-3 years) as arterial or laparotomy related, respectively, and ranked for severity by surgeons and patients separately. Rare re-interventions to 1 year, were summarised across three ruptured abdominal aortic aneurysm trials (IMPROVE, AJAX, and ECAR) and odds ratios (OR) describing differences were pooled via meta-analysis.

RESULTS

Re-interventions were most common in the first 90 days. Overall rates were 186 and 226 per 100 person years for the endovascular strategy and open repair groups, respectively (p = .20) but between 3 months and 3 years (mid-term) the rates had slowed to 9.5 and 6.0 re-interventions per 100 person years, respectively (p = .090) and about one third of these were for a life threatening condition. In this latter, mid-term period, 42 of 313 remaining patients (13%) required at least one re-intervention, most commonly for endoleak or other endograft complication after treatment by endovascular aneurysm repair (EVAR) (21 of 38 re-interventions), whereas distal aneurysms were the commonest reason (four of 23) for re-interventions after treatment by open repair. Arterial re-interventions within 3 years were associated with increasing common iliac artery diameter (OR 1.48, 95% confidence interval [CI] 0.13-0.93; p = .004). Amputation, rare but ranked as the worst re-intervention by patients, was less common in the first year after treatment with EVAR (OR 0.2, 95% CI 0.05-0.88) from meta-analysis of three trials.

CONCLUSION

The rate of mid-term re-interventions after rupture is high, more than double that after elective EVAR and open repair, suggesting the need for bespoke surveillance protocols. Amputations are much less common in patients treated by EVAR than in those treated by open repair.

Value of risk scores in the decision to palliate patients with ruptured abdominal aortic aneurysm

Background

The aim of this study was to develop a 48‐h mortality risk score, which included morphology data, for patients with ruptured abdominal aortic aneurysm presenting to an emergency department, and to assess its predictive accuracy and clinical effectiveness in triaging patients to immediate aneurysm repair, transfer or palliative care.

Methods

Data from patients in the IMPROVE (Immediate Management of the Patient With Ruptured Aneurysm: Open Versus Endovascular Repair) randomized trial were used to develop the risk score. Variables considered included age, sex, haemodynamic markers and aortic morphology. Backwards selection was used to identify relevant predictors. Predictive performance was assessed using calibration plots and the C‐statistic. Validation of the newly developed and other previously published scores was conducted in four external populations. The net benefit of treating patients based on a risk threshold compared with treating none was quantified.

Results

Data from 536 patients in the IMPROVE trial were included. The final variables retained were age, sex, haemoglobin level, serum creatinine level, systolic BP, aortic neck length and angle, and acute myocardial ischaemia. The discrimination of the score for 48‐h mortality in the IMPROVE data was reasonable (C‐statistic 0·710, 95 per cent c.i. 0·659 to 0·760), but varied in external populations (from 0·652 to 0·761). The new score outperformed other published risk scores in some, but not all, populations. An 8 (95 per cent c.i. 5 to 11) per cent improvement in the C‐statistic was estimated compared with using age alone.

Conclusion

The assessed risk scores did not have sufficient accuracy to enable potentially life‐saving decisions to be made regarding intervention. Focus should therefore shift to offering repair to more patients and reducing non‐intervention rates, while respecting the wishes of the patient and family.

Not much help

Comparative analysis of the outcomes of elective abdominal aortic aneurysm repair in England and Sweden

Background

There is substantial international variation in mortality after abdominal aortic aneurysm (AAA) repair; many non‐operative factors influence risk‐adjusted outcomes. This study compared 90‐day and 5‐year mortality for patients undergoing elective AAA repair in England and Sweden.

Methods

Patients were identified from English Hospital Episode Statistics and the Swedish Vascular Registry between 2003 and 2012. Ninety‐day mortality and 5‐year survival were compared after adjustment for age and sex. Separate within‐country analyses were performed to examine the impact of co‐morbidity, hospital teaching status and hospital annual caseload.

Results

The study included 36 249 patients who had AAA treatment in England, with a median age of 74 (i.q.r. 69–79) years, of whom 87·2 per cent were men. There were 7806 patients treated for AAA in Sweden, with a median of age 73 (68–78) years, of whom 82·9 per cent were men. Ninety‐day mortality rates were poorer in England than in Sweden (5·0 versus 3·9 per cent respectively; P < 0·001), but were not significantly different after 2007. Five‐year survival was poorer in England (70·5 versus 72·8 per cent; P < 0·001). Use of EVAR was initially lower in England, but surpassed that in Sweden after 2010. In both countries, poor outcome was associated with increased age. In England, institutions with higher operative annual volume had lower mortality rates.

Conclusion

Mortality for elective AAA repair was initially poorer in England than Sweden, but improved over time alongside greater uptake of EVAR, and now there is no difference. Centres performing a greater proportion of EVAR procedures achieved better results in England.

Improving in England

Using multiple classifiers for predicting the risk of endovascular aortic aneurysm repair re-intervention through hybrid feature selection

Feature selection is essential in medical area; however, its process becomes complicated with the presence of censoring which is the unique character of survival analysis. Most survival feature selection methods are based on Cox's proportional hazard model, though machine learning classifiers are preferred. They are less employed in survival analysis due to censoring which prevents them from directly being used to survival data. Among the few work that employed machine learning classifiers, partial logistic artificial neural network with auto-relevance determination is a well-known method that deals with censoring and perform feature selection for survival data. However, it depends on data replication to handle censoring which leads to unbalanced and biased prediction results especially in highly censored data. Other methods cannot deal with high censoring. Therefore, in this article, a new hybrid feature selection method is proposed which presents a solution to high level censoring. It combines support vector machine, neural network, and K-nearest neighbor classifiers using simple majority voting and a new weighted majority voting method based on survival metric to construct a multiple classifier system. The new hybrid feature selection process uses multiple classifier system as a wrapper method and merges it with iterated feature ranking filter method to further reduce features. Two endovascular aortic repair datasets containing 91% censored patients collected from two centers were used to construct a multicenter study to evaluate the performance of the proposed approach. The results showed the proposed technique outperformed individual classifiers and variable selection methods based on Cox's model such as Akaike and Bayesian information criterions and least absolute shrinkage and selector operator in p values of the log-rank test, sensitivity, and concordance index. This indicates that the proposed classifier is more powerful in correctly predicting the risk of re-intervention enabling doctor in selecting patients' future follow-up plan.

Feature selection through validation and un-censoring of endovascular repair survival data for predicting the risk of re-intervention

Background

Feature selection (FS) process is essential in the medical area as it reduces the effort and time needed for physicians to measure unnecessary features. Choosing useful variables is a difficult task with the presence of censoring which is the unique characteristic in survival analysis. Most survival FS methods depend on Cox’s proportional hazard model; however, machine learning techniques (MLT) are preferred but not commonly used due to censoring. Techniques that have been proposed to adopt MLT to perform FS with survival data cannot be used with the high level of censoring. The researcher’s previous publications proposed a technique to deal with the high level of censoring. It also used existing FS techniques to reduce dataset dimension. However, in this paper a new FS technique was proposed and combined with feature transformation and the proposed uncensoring approaches to select a reduced set of features and produce a stable predictive model.

Methods

In this paper, a FS technique based on artificial neural network (ANN) MLT is proposed to deal with highly censored Endovascular Aortic Repair (EVAR). Survival data EVAR datasets were collected during 2004 to 2010 from two vascular centers in order to produce a final stable model. They contain almost 91% of censored patients. The proposed approach used a wrapper FS method with ANN to select a reduced subset of features that predict the risk of EVAR re-intervention after 5 years to patients from two different centers located in the United Kingdom, to allow it to be potentially applied to cross-centers predictions. The proposed model is compared with the two popular FS techniques; Akaike and Bayesian information criteria (AIC, BIC) that are used with Cox’s model.

Results

The final model outperforms other methods in distinguishing the high and low risk groups; as they both have concordance index and estimated AUC better than the Cox’s model based on AIC, BIC, Lasso, and SCAD approaches. These models have p-values lower than 0.05, meaning that patients with different risk groups can be separated significantly and those who would need re-intervention can be correctly predicted.

Conclusion

The proposed approach will save time and effort made by physicians to collect unnecessary variables. The final reduced model was able to predict the long-term risk of aortic complications after EVAR. This predictive model can help clinicians decide patients’ future observation plan.

Electronic supplementary material

The online version of this article (doi:10.1186/s12911-017-0508-3) contains supplementary material, which is available to authorized users.

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

Supplemental Digital Content is available in the text.

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.

Thresholds for Abdominal Aortic Aneurysm Repair in England and the United States

BACKGROUND

Thresholds for repair of abdominal aortic aneurysms vary considerably among countries.

METHODS

We examined differences between England and the United States in the frequency of aneurysm repair, the mean aneurysm diameter at the time of the procedure, and rates of aneurysm rupture and aneurysm-related death. Data on the frequency of repair of intact (nonruptured) abdominal aortic aneurysms, in-hospital mortality among patients who had undergone aneurysm repair, and rates of aneurysm rupture during the period from 2005 through 2012 were extracted from the Hospital Episode Statistics database in England and the U.S. Nationwide Inpatient Sample. Data on the aneurysm diameter at the time of repair were extracted from the U.K. National Vascular Registry (2014 data) and from the U.S. National Surgical Quality Improvement Program (2013 data). Aneurysm-related mortality during the period from 2005 through 2012 was determined from data obtained from the Centers for Disease Control and Prevention and the U.K. Office of National Statistics. Data were adjusted with the use of direct standardization or conditional logistic regression for differences between England and the United States with respect to population age and sex.

RESULTS

During the period from 2005 through 2012, a total of 29,300 patients in England and 278,921 patients in the United States underwent repair of intact abdominal aortic aneurysms. Aneurysm repair was less common in England than in the United States (odds ratio, 0.49; 95% confidence interval [CI], 0.48 to 0.49; P<0.001), and aneurysm-related death was more common in England than in the United States (odds ratio, 3.60; 95% CI, 3.55 to 3.64; P<0.001). Hospitalization due to an aneurysm rupture occurred more frequently in England than in the United States (odds ratio, 2.23; 95% CI, 2.19 to 2.27; P<0.001), and the mean aneurysm diameter at the time of repair was larger in England (63.7 mm vs. 58.3 mm, P<0.001).

CONCLUSIONS

We found a lower rate of repair of abdominal aortic aneurysms and a larger mean aneurysm diameter at the time of repair in England than in the United States and lower rates of aneurysm rupture and aneurysm-related death in the United States than in England. (Funded by the Circulation Foundation and others.).

Extended use of endovascular aneurysm sealing: Chimneys for juxtarenal aneurysms

Hostile infrarenal aortic neck anatomy presents a challenge for the endovascular treatment of abdominal aortic aneurysm. Open surgical repair has been seen as the gold standard treatment for juxtarenal abdominal aortic aneurysm; however, endovascular techniques are now becoming more prevalent, particularly in patients deemed high risk for morbidity and mortality with open repair. The morphology of an aneurysm is a determinant of long-term outcomes, and short aneurysm necks are associated with poorer outcomes and a higher rate of secondary reinterventions. Parallel grafts have been used in combination with endovascular aneurysm repair to elongate the sealing zone into the paravisceral segment of the aorta. This technique is associated with a risk of proximal Type I endoleak due to "guttering." This risk may be decreased when parallel grafts are used in combination with endovascular aneurysm sealing and, as such, this technique may represent an alternative to current techniques for the treatment of juxtarenal abdominal aortic aneurysm, such as the use of conventional bifurcated grafts (with or without parallel grafts) and fenestrated endovascular stent grafts.

Expansion rate of descending thoracic aortic aneurysms

BACKGROUND

Surveillance is mandatory for all patients with a thoracic aortic aneurysm (TAA). The frequency of surveillance imaging, however, is not evidence-based, as few data exist regarding TAA growth rates. This study aimed to determine the rate of TAA expansion and to inform surveillance intervals based on TAA diameter.

METHODS

Patients with a TAA for whom morphological data were available from serial CT scans were studied. Annualized growth rates based on diameter at presentation and time taken to reach a theoretical intervention threshold of 55 mm were calculated. The number of patients who would have achieved the threshold undetected was determined based on simulated imaging intervals of 6 months, 1, 2 and 3 years.

RESULTS

A total of 2916 scans from 995 patients were analysed. The mean aortic expansion rate was 2·76 mm per year for all patients, with an exponential increase observed at sizes above 45 mm. Only 3·9 per cent of patients with a starting diameter of 30-39 mm and 5·3 per cent of those with a diameter of 40-44 mm achieved threshold size within 2 years. Conversely, the probability of expansion to more than 55 mm was 74·5 per cent in 2 years for patients with a starting diameter of 50-54 mm, rising to 85·7 per cent at 3 years.

CONCLUSION

Based on a threshold of 55 mm for intervention, most patients with a maximum aortic diameter below 40 mm could safely undergo surveillance at 2-yearly intervals. Above 45 mm, annual surveillance is recommended. Patients with a diameter greater than 50 mm could be optimized for possible repair, if this is clinically appropriate.

Cardiovascular risk prevention and all-cause mortality in primary care patients with an abdominal aortic aneurysm

BACKGROUND

Perioperative mortality is low for patients undergoing abdominal aortic aneurysm (AAA) repair, but long-term survival remains poor. Although patients diagnosed with AAA have a significant burden of cardiovascular disease and associated risk factors, there is limited understanding of the contribution of cardiovascular risk management to long-term survival.

METHODS

General practice records within The Health Improvement Network (THIN) were examined. Patients with a diagnosis of AAA and at least 1 year of registered medical history were identified from 2000 to 2012. Medical therapies for cardiovascular risk were classified as antiplatelet, statin or antihypertensive agents. Progression to death was investigated using the G-computation formula with time-dependent co-variables to account for differences in exposure to cardiovascular risk-modifying treatments and the confounding between exposure, co-morbidities and death.

RESULTS

Some 12 485 patients had a recorded diagnosis of AAA. From 2000 to 2012, prescription of medications that modify cardiovascular risk increased: from 26·6 to 76·7 per cent for statins, from 56·5 to 73·9 per cent for antiplatelet agents and from 75·3 to 84·0 per cent for antihypertensive drugs. Adjusted Kaplan-Meier curves demonstrated a better 5-year survival rate in patients receiving statins (68·4 versus 42·2 per cent), antiplatelet agents (63·6 versus 39·7 per cent) or antihypertensive agents (61·5 versus 39·1 per cent), compared with rates in patients not receiving each therapy.

CONCLUSION

Appropriate risk factor modification could significantly reduce long-term mortality in patients with AAA. In the UK, up to 30 per cent of patients are not currently receiving these medications.

Early outcomes after left subclavian artery revascularisation in association with thoracic endovascular aortic repair

Approximately 40–50% of patients undergoing thoracic endovascular aortic repair require left subclavian artery coverage for adequate proximal landing zone. Many of these patients undergo left subclavian artery revascularisation. However, outcomes data for left subclavian artery revascularisation in the context of thoracic endovascular aortic repair remain limited. In this study, 70 left subclavian artery revascularisation procedures, performed on thoracic endovascular aortic repair patients at a tertiary hospital, were retrospectively reviewed. Particular emphasis was placed on revascularisation-related outcomes during staging interval between revascularisation and thoracic endovascular aortic repair. Forty-six (66%) carotid-subclavian bypass, 17 (24%) carotid-carotid-subclavian bypass and 7 (10%) aorto-inominate-carotid-subclavian bypass procedures were performed. There were no strokes or mortalities following left subclavian artery revascularisation procedures alone. Three (10%) minor complications occurred including a seroma, a haematoma and a temporary neuropraxia. Separation of complications following left subclavian artery revascularisation from those of the associated thoracic endovascular aortic repair can be difficult. Early outcomes data from patients who underwent left subclavian artery revascularisation in isolation indicate that the procedure is safe with low complication rates.

Microvascular disease and risk of cardiovascular events among individuals with type 2 diabetes: a population-level cohort study

BACKGROUND

Diabetes confers a two times excess risk of cardiovascular disease, yet predicting individual risk remains challenging. The effect of total microvascular disease burden on cardiovascular disease risk among individuals with diabetes is unknown.

METHODS

A population-based cohort of patients with type 2 diabetes from the UK Clinical Practice Research Datalink was studied (n=49 027). We used multivariable Cox models to estimate hazard ratios (HRs) for the primary outcome (the time to first major cardiovascular event, which was a composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal ischaemic stroke) associated with cumulative burden of retinopathy, nephropathy, and peripheral neuropathy among individuals with no history of cardiovascular disease at baseline.

FINDINGS

During a median follow-up of 5·5 years, 2822 (5·8%) individuals experienced a primary outcome. After adjustment for established risk factors, significant associations were observed for the primary outcome individually for retinopathy (HR 1·39, 95% CI 1·09-1·76), peripheral neuropathy (1·40, 1·19-1·66), and nephropathy (1·35, 1·15-1·58). For individuals with one, two, or three microvascular disease states versus none, the multivariable-adjusted HRs for the primary outcome were 1·32 (95% CI 1·16-1·50), 1·62 (1·42-1·85), and 1·99 (1·70-2·34), respectively. For the primary outcome, measures of risk discrimination showed significant improvement when microvascular disease burden was added to models. In the overall cohort, the net reclassification index for USA and UK guideline risk strata were 0·036 (95% CI 0·017-0·055, p<0·0001) and 0·038 (0·013-0·060, p<0·0001), respectively.

INTERPRETATION

The cumulative burden of microvascular disease significantly affects the risk of future cardiovascular disease among individuals with type 2 diabetes. Given the prevalence of diabetes globally, further work to understand the mechanisms behind this association and strategies to mitigate this excess risk are warranted.

FUNDING

Circulation Foundation.

Ultrasound-Based Quantification of Emboli during Conventional and Endovascular Aneurysm Repair

Purpose:

To differentiate and quantify the type and number of lower limb emboli occurring during endovascular aneurysm repair, as compared to conventional surgery.

Methods:

Thirty-eight patients underwent elective infrarenal aneurysm repair using a conventional surgical approach in 18 and an endovascular procedure in 20. Emboli were detected using a Doppler ultrasound system with a 2-MHz transducer interrogating the mid superficial femoral artery. Lower limb emboli were differentiated as particulate or gaseous based on the physical distance traversed by the embolic signal.

Results:

Significantly more particulate (median 108 versus 59, p = 0.015) and gaseous (134 versus 46, p = 0.008) emboli were detected during endovascular aneurysm repair as compared to conventional surgery. Clinically, no case of massive microembolization occurred in either group, but one patient in the conventional group required a femoral embolectomy, and three patients undergoing endovascular repair developed self-limiting trash feet postoperatively. In patients undergoing endovascular aortomonoiliac aneurysm repair, there was only a poor correlation between the number of particulate emboli and either procedural duration or operator experience.

Conclusions:

The apparent lack of a relationship between particulate embolization and operative time or technical experience suggests that manipulation of endoluminal devices within the aneurysm sac may not be the sole determinant of intraprocedural embolization. Other as yet undetermined factors may predict patients at high risk for massive embolization.

Proximal Stent Deployment without Contrast during Endovascular Aneurysm Repair: An Improved Technique

Purpose:

To describe a technique to enhance stent visibility on the fluoroscopic monitor during aortic endograft deployment.

Technique:

To assist in accurate positioning and deployment of the proximal stent in a Parodi-type aortic endograft, the stent is affixed to the balloon so that the radiopaque marker sits at the stent's distal end. When the device is in position and the sheath is retracted, the stent and the radiopaque balloon markers are clearly seen on the fluoroscopic image. Using normal saline only to inflate the balloon allows the stent to remain visible throughout deployment.

Conclusions:

The use of saline rather than contrast medium for balloon inflation provides continuous visualization of the stent during expansion, thus facilitating accurate deployment and early recognition of balloon migration within the stent.

Quality Control during Endovascular Aneurysm Repair: Monitoring Aneurysmal Sac Pressure and Superficial Femoral Artery Flow Velocity

Purpose:

To use intraoperative aneurysmal sac pressure measurement and flow monitoring of the superficial femoral artery (SFA) to ensure complete exclusion of the aneurysm from the circulation.

Methods:

A 5F catheter was positioned in the aneurysmal sac of 15 consecutive patients undergoing endovascular aortomonoiliac aneurysm repair between February and September 1997. The catheter was connected to an external pressure transducer allowing pressure monitoring throughout the operation and for 24 hours postprocedurally. Flow velocity was monitored in the contralateral SFA by insonation with a 2-MHz Doppler ultrasound probe.

Results:

No technical defect was observed in the deployment of 10 endografts, which demonstrated marked reduction in sac pressure and good flow in the lower limb. The mean aneurysm pressure dropped from 123 to 57 mmHg after graft insertion. In 5 cases, monitoring detected problems during the endograft procedure. In 3, incomplete stent deployment was detected by a failure of sac pressure to fall following stent inflation and by the presence of flow in the contralateral femoral artery. In the other 2 cases, a distal endoleak was detected by direct injection of contrast into the sac.

Conclusions:

Measuring aneurysm pressure in combination with SFA Doppler flow monitoring can detect complications of endovascular aneurysm repair.

Aortomonoiliac Endovascular Grafting: Difficult Solutions to Difficult Aneurysms

Purpose:

To describe a refined technique for aortomonoiliac endograft exclusion of abdominal aortic aneurysms (AAAs).

Methods:

A tapered aortomonoiliac graft was prepared from an 8-mm thin-walled expanded polytetrafluoroethylene tube graft predilated proximally to 35 mm and tapered distally to 15 mm. The proximal graft was sutured to a 5-cm-long, predilated Palmaz stent, which was mounted on a 30-mm balloon and backloaded into a 21F packaging sheath. With the patient under general anesthesia and both common femoral arteries exposed, the endograft was anchored in the infrarenal aorta and subsequently passed into one iliac system, where it was anastomosed to the iliac or femoral vessels. The contralateral common iliac artery was occluded, and an extra-anatomic, femorofemoral, or iliofemoral bypass grafting was performed.

Results:

Twenty of the 25 AAAs treated to date with this technique have been successful, with aneurysm exclusion achieved in 18 (2 minor distal endoleaks are scheduled for endovascular repair). The technical failures were analyzed, resulting in enhancements to the technique. Complications included 2 early (< 30 days) deaths, 1 case of minor embolization, 1 transient renal failure, 1 pulmonary embolus, and 1 wound infection. The only late complication was a graft infection localized to the groin.

Conclusions:

Aortomonoiliac endovascular aneurysm repair is effective in patients with AAAs involving the iliac arteries. Short-term results are acceptable, but long-term efficacy must be addressed before this procedure is widely adopted. Technical changes made in response to early learning curve problems have led to a safer, more reliable procedure.

Torsion and Kinking of Unsupported Aortic Endografts: Treatment by Endovascular Intervention

Purpose:

To describe the management strategies used to deal with twisted aortic endografts.

Methods and Results:

Two patients with successfully excluded aortic aneurysms developed symptoms referable to previously undetected twists in their endografts (one EndoVascular Technologies [EVT] and one customized aortomonoiliac device). The limb graft occlusion in the EVT graft was treated surgically with a femorofemoral bypass, but the aortomonoiliac endograft was salvaged with percutaneous implantation of a Wallstent. During another aortomonoiliac procedure, suboptimal flow through the endograft was traced to contortion of the endograft as it passed over an angulated proximal aneurysm neck. An X-large Palmaz stent was deployed to support the graft at this point.

Conclusions:

Unsupported aortic endografts may develop twists and kinks during deployment that can lead to low outflow and graft occlusion. Endovascular techniques are available to repair these defects postoperatively, although more precise intraoperative assessment tools may identify these problems so that they can be corrected at the initial intervention.

Improved Respiratory Function and Analgesia Control after Endovascular AAA Repair

Purpose:

Endovascular abdominal aortic aneurysm (AAA) repair has been proposed as a minimally invasive alternative to conventional surgery and may offer significant advantages in respiratory function and analgesic requirements due to the absence of an abdominal incision.

Methods:

Respiratory function and analgesic requirements were quantified in 22 age-matched patients undergoing aneurysm repair under general anesthesia. Twelve patients underwent endovascular aneurysm repair, while 10 AAA patients had conventional surgery. One endovascular patient required conversion to conventional repair.

Results:

The endovascular group required postoperative artificial ventilation for a shorter time (6 versus 21 hours, p < 0.05) and had lower PCA (patient-controlled analgesia) morphine consumption (41 versus 133 mg, p < 0.05) than the conventional group. The endovascular group also had significantly better forced expiratory volume and forced vital capacity at both 3 and 5 days when expressed as percentages of the preoperative values (p < 0.05).

Conclusions:

Endovascular AAA repair attenuates respiratory dysfunction associated with conventional surgery and reduces perioperative analgesia requirements.

Changes in Referral Practice, Workload, and Operative Mortality after Establishment of an Endovascular Abdominal Aortic Aneurysm Program

Purpose:

To determine the change in referral practice following establishment of an endovascular abdominal aortic aneurysm (AAA) program.

Methods:

A prospective audit of all elective admissions for AAA was established in January 1994 at the initiation of an endovascular AAA program. A comparison was made between this cohort and the elective AAA repairs performed between 1981 and 1993.

Results:

Since January 1994, 213 AAA patients (177 men; median age 73 years, range 54 to 88) have been referred for potential endovascular aneurysm repair. To date, 142 patients have undergone elective surgery (41 endovascular and 101 conventional). Between 1981 and 1993, 304 patients (255 men; median age 69 years, range 45 to 86) had elective aneurysm repair. Comparison of the two time periods has revealed significant increases in the number of tertiary referrals (41.8% versus 9.5%, p < 0.01), annual operations (50 versus 23, p < 0.05), and overall mortality (12% versus 6.7%, p < 0.05), the latter attended by a significant increase in cardiorespiratory comorbidity.

Conclusions:

The higher elective AAA mortality rate since the establishment of an endovascular program reflects a change in referral practice and may be directly attributable to an increase in the number of high-risk patients. An endovascular AAA program has clinical and financial implications for the hospital concerned.

Endovascular Repair of Aortic Aneurysms in the Presence of a Horseshoe Kidney

Purpose:

To report two cases of endovascular aortic aneurysm exclusion in patients with a horseshoe kidney.

Methods and Results:

Two male patients, one with a known horseshoe kidney and history of multiple previous laparotomies, presented with abdominal aortic aneurysms of approximately 6-cm diameter. Each was treated with a tapered aortomonoiliac polytetrafluoroethylene graft secured proximally with a Palmaz balloon-expandable stent. The endograft was sutured distally to a Dacron femorofemoral crossover graft. An anomalous renal vessel was sacrificed in one case. The aneurysms were successfully excluded, and the patients recovered without sequelae.

Conclusions:

Endovascular repair should be considered as a treatment option in patients with aortic aneurysm in the presence of a horseshoe kidney, particularly if the renal vasculature can be wholly preserved.

Quality of life, symptoms and treatment satisfaction in patients with aortic aneurysm using new abdominal aortic aneurysm-specific patient-reported outcome measures

Background

The aim of this study was to present preliminary data on quality of life (QoL), symptoms and treatment satisfaction gathered using three new abdominal aortic aneurysm (AAA)-specific patient-reported outcome measures (PROMs).

Methods

Patients with AAA were recruited from five National Health Service Trusts to complete the three new PROMs: the AneurysmDQoL, AneurysmSRQ and AneurysmTSQ. Patients were either under surveillance or had undergone AAA repair (open or endovascular) during the preceding 24 months. Data were initially collected as part of a study assessing the psychometric properties of the new measures, before being used in the observational analysis of outcomes presented here.

Results

Results, although largely non-significant, showed interesting trends. The impact of AAA repair on QoL appeared to worsen progressively after open repair (OR) and improve progressively after endovascular aneurysm repair (EVAR). Conversely, symptoms seemed to become progressively worse after EVAR and progressively better after OR. Information and understanding were key sources of dissatisfaction before the intervention, whereas postoperative dissatisfaction was related to bother from symptoms, follow-up and feedback about scan results.

Conclusion

Although a larger, prospective data set is necessary to explore outcomes more fully with the new AAA-specific PROMs, the observational data presented here suggest there may be clinically important differences in the symptoms, impact on QoL and treatment satisfaction associated with OR and EVAR.

Transthoracic Echocardiography Provides Important Long-Term Prognostic Information in Selected Patients Undergoing Endovascular Abdominal Aortic Repair

BACKGROUND

The value of performing transthoracic echocardiography (TTE) as part of the clinical assessment of patients awaiting endovascular repair of the abdominal aorta is little evaluated. We aimed to estimate the prognostic importance of information derived from TTE on long-term all-cause mortality in a selected group of patients undergoing endovascular aneurysm repair.

METHODS AND RESULTS

This was a retrospective cohort study of 273 consecutive patients selected for endovascular aneurysm repair. All patients included in the analysis underwent TTE before their procedure. Multivariable Cox regression analysis was used to estimate the effect of TTE measures on all-cause mortality. Over a mean follow-up of 3.2±1.5 years, there were 78 deaths with a mean time to death of 1.28±1.16 years. A greater tubular ascending aorta (hazard ratio [HR] 5.6, 95% confidence interval [CI] 2.77-11.33), presence of mitral regurgitation (HR 8.13, 95% CI 4.09-12.16), lower left ventricular ejection fraction (HR 0.96, 95% CI 0.93-0.98), younger age (HR 0.97, 95% CI 0.95-0.99), and presence of diabetes mellitus (HR 1.46, 95% CI 1.24-1.89) were predictors of all-cause mortality.

CONCLUSIONS

Echocardiography provides important long-term prognostic information in patients undergoing endovascular aneurysm repair. These TTE indices were more important at predicting outcome than standard conventional risk factors in this patient group. A greater tubular ascending aorta, presence of mitral regurgitation, reduced left ventricular ejection fraction, younger age, and diabetes mellitus were independently associated with long-term mortality.

Design of new patient-reported outcome measures to assess quality of life, symptoms and treatment satisfaction in patients with abdominal aortic aneurysm

Background

No condition-specific patient-reported outcome measures exist for patients with abdominal aortic aneurysm (AAA). The aim of this work was to develop three questionnaires to assess quality of life (QoL), symptoms and treatment satisfaction in patients with AAA.

Methods

Semistructured interview techniques were used to explore patients' experiences of having an AAA in a series of focus groups and in-depth interviews. The information gathered was used to inform design and selection of items for the new tools; the overall structure of the new questionnaires was based on tools developed previously for patients with diabetes and other conditions.

Results

Fifty-four patients (51 men, 3 women; mean age 71·9 years) were recruited from four NHS Trusts to participate in focus groups or interviews, either while under surveillance, or following AAA repair (using open or endovascular techniques). The Aneurysm-Dependent Quality of Life Questionnaire (AneurysmDQoL) is an individualized measure of the impact of AAA on patients' QoL. Twenty-three domains were chosen specifically for their relevance to patients with AAA, with a further two overview items to assess overall QoL and the impact of AAA on QoL. The Aneurysm Symptom Rating Questionnaire (AneurysmSRQ) is a 44-item measure assessing physical and psychological symptoms reported by patients with AAA. The Aneurysm Treatment Satisfaction Questionnaire (AneurysmTSQ) contains 11 items, suitable for patients before and after surgical intervention.

Conclusion

The iterative development process reported here has confirmed that these three new tools have good face and content validity for patients with AAA.

Mortality of emergency general surgical patients and associations with hospital structures and processes

BACKGROUND

Variations in patient outcomes between providers have been described for emergency admissions, including general surgery. The aim of this study was to investigate whether differences in modifiable hospital structures and processes were associated with variance in mortality, amongst patients admitted for emergency colorectal laparotomy, peptic ulcer surgery, appendicectomy, hernia repair and pancreatitis.

METHODS

Adult emergency admissions in the English NHS were extracted from the Hospital Episode Statistics between April 2005 and March 2010. The association between mortality and structure and process measures including medical and nursing staffing levels, critical care and operating theatre availability, radiology utilization, teaching hospital status and weekend admissions were investigated.

RESULTS

There were 294 602 emergency admissions to 156 NHS Trusts (hospital systems) with a 30-day mortality of 4.2%. Trust-level mortality rates for this cohort ranged from 1.6 to 8.0%. The lowest mortality rates were observed in Trusts with higher levels of medical and nursing staffing, and a greater number of operating theatres and critical care beds relative to provider size. Higher mortality rates were seen in patients admitted to hospital at weekends [OR 1.11 (95% CI 1.06-1.17) P<0.0001], in Trusts with fewer general surgical doctors [1.07 (1.01-1.13) P=0.019] and with lower nursing staff ratios [1.07 (1.01-1.13) P=0.024].

CONCLUSIONS

Significant differences between Trusts were identified in staffing and other infrastructure resources for patients admitted with an emergency general surgical diagnosis. Associations between these factors and mortality rates suggest that potentially modifiable factors exist that relate to patient outcomes, and warrant further investigation.

Preoperative morphology influences thoracic aortic aneurysm sac expansion after endovascular repair

Background

The fate of the aneurysm sac after thoracic endovascular aortic repair (TEVAR) remains poorly defined. The aim of this study was to characterize the incidence of aneurysm sac expansion after TEVAR, and to determine the effect of aneurysm morphology on postoperative sac behaviour.

Methods

Preoperative and postoperative CT angiography (CTA) images were analysed from a proprietary database (M2S). TEVARs undertaken for thoracic aortic aneurysms from 2004 to 2013 were included. Preoperative aortic morphology was available for each patient. Post-TEVAR sac expansion was defined as an increase in aortic diameter of at least 5 mm. The influence of aortic morphological variables on sac expansion was assessed using Cox regression and Kaplan–Meier analysis.

Results

CTA images were available for 899 patients who underwent TEVAR. Median follow-up was 2·1 (i.q.r. 1·7–2·4) years. Some 46·0 per cent had a maximum aneurysm diameter of 55 mm or more at the time of repair. The 5-year rate of freedom from sac expansion of at least 5 mm was 60·9 per cent. The sac expansion rate after 3 years was higher when the proximal sealing zone was over 38 mm in diameter (freedom from expansion 51·2 per cent versus 76·6 per cent for diameter 38 mm or less; P &lt; 0·001), or 20 mm or less in length (freedom from expansion 67·3 per cent versus 77·1 per cent for length exceeding 20 mm; P = 0·022). Findings for the distal sealing zone were similar. The risk of sac expansion increased according to the number of adverse morphological risk factors (freedom from expansion rate 79·1 per cent at 3 years in patients with 2 or fewer risk factors versus 45·7 per cent in those with more than 2; P &lt; 0·001).

Conclusion

Sac expansion was common in this cohort of patients undergoing TEVAR for thoracic aortic aneurysm. Aneurysm sac expansion was significantly influenced by adverse morphological features in the aortic stent-graft sealing zones.

Appearance of the Nellix endovascular aneurysm sealing system on computed tomography: implications for postoperative imaging surveillance

PURPOSE

To describe the imaging characteristics of the Nellix Endovascular Aneurysm Sealing (EVAS) System on serial computed tomography (CT) surveillance.

METHODS

Sixty-eight patients undergoing EVAS were enrolled in a surveillance protocol that included CT scans prior to hospital discharge and at 3, 6, and 9 months postoperatively. Images were analyzed for the presence of gas within the endobag, endoleak, and for maximum radiodensity measured in Hounsfield units (HU) within the uppermost, middle, and lowermost regions of each endobag.

RESULTS

Gas was seen within the endobags of all 68 EVAS repairs at the first postoperative CT compared with 2 (5.6%) of 36 undergoing the 3-month scan. The endobags appeared radiodense during initial imaging, and the median (interquartile range) radiodensity of the Nellix polymer decreased from 158.3 HU (149.5; 169.5) at the postoperative CT to 81.0 HU (74.0; 88.0) at 3 months, excluding 3 cases in which contrast pre-fill was utilized. Type I endoleak was seen at the periphery of the aneurysm sac or in the cleft between the endobags, with a substantially different appearance to endoleak after endovascular aneurysm repair.

CONCLUSION

The evolution of CT appearances after EVAS was characteristic and predictable. The device endobags were initially radiodense, which may impact the detection of endoleak within 3 months of EVAS. Endoleaks after EVAS were seen in a different anatomical area to endoleaks after conventional stent-graft repair.

Comparison of long-term mortality after ruptured abdominal aortic aneurysm in England and Sweden

BACKGROUND

Concern has been raised regarding international discrepancies in perioperative mortality after repair of ruptured abdominal aortic aneurysm (rAAA). The variation in in-hospital mortality is difficult to interpret, owing to international differences in discharge strategies. This study compared 90-day and 5-year mortality in patients who had a rAAA in England and Sweden.

METHODS

Patients undergoing rAAA repair were identified from English Hospital Episode Statistics and the Swedish Vascular Registry (Swedvasc) between 2003 and 2012. Ninety-day and 5-year mortality were compared after matching for age and sex. Within-country analyses examined the impact of co-morbidity, teaching hospital status or hospital annual caseload, adjusted with causal inference techniques.

RESULTS

Some 12 467 patients underwent rAAA repair in England, of whom 83.2 per cent were men; the median (i.q.r.) age was 75 (70-80) years. A total of 2829 Swedish patients underwent rAAA repair, of whom 81.3 per cent were men; their median (i.q.r.) age was 75 (69-80) years. The 90-day mortality rate was worse in England (44.0 per cent versus 33.4 per cent in Sweden; P < 0.001), as was 5-year mortality (freedom from mortality 38.6 versus 46.3 per cent respectively; P < 0.001). In England, lower mortality was seen in teaching hospitals with larger bed capacity, higher annual caseloads and greater use of endovascular aneurysm repair (EVAR). In Sweden, lower mortality was associated with EVAR, high annual caseload, or surgery on weekdays compared with weekends.

CONCLUSION

Short- and long-term mortality after rAAA repair was higher in England. In both countries, mortality was lowest in centres performing greater numbers of AAA repairs per annum, and more EVAR procedures.

Appendicitis during pregnancy with a normal MRI

Abdominal pain frequently represents a diagnostic challenge in the acute setting. In pregnant patients, the gravid abdomen and concern for ionizing radiation exposure further limit evaluation. If undiagnosed, appendicitis may cause disastrous consequences for the mother and fetus. We present the case of a pregnant female who was admitted for right lower quadrant abdominal pain. Advanced imaging of the abdomen and pelvis was interpreted to be either indeterminate or normal and a diagnosis of acute appendicitis was made on purely clinical grounds. This patient’s management and a literature review of diagnostic techniques for acute appendicitis during pregnancy are discussed.

Investigating the Effect of a Single Infusion of Reconstituted High-Density Lipoprotein in Patients with Symptomatic Carotid Plaques

Background

Elevation of plasma high-density lipoprotein (HDL) cholesterol concentration reduces cardiovascular mortality and morbidity. HDLs have been shown to possess acute anti-inflammatory, antioxidant, and antithrombotic properties. We hypothesize that HDL therapy can acutely alter local and systemic manifestations of plaque instability.

Methods

Forty patients with early symptomatic carotid disease were randomized to either receive reconstituted HDL (rHDL) 40 mg/kg (n = 20) or placebo (n = 20). Carotid endarterectomies were performed 24 hr later. Plaques were obtained intraoperatively and used for measurement of thrombomodulatory genes expression. Plasma samples were collected before the infusion, 24 and 48 hr later to measure changes in systemic markers of plaque instability.

Results

No significant differences were noted in thrombomodulatory genes expression between the 2 groups. Systemic levels of tissue factor, matrix metalloproteinase 9 (MMP-9), and monocyte chemotactic factor-1 (MCP-1) were significantly reduced in the rHDL group. However, the effects on MMP-9 and MCP-1 were abolished in the immediate postoperative period. Although rHDL did not affect plasma interleukin-6 levels 24 hr following the infusion, it prevented the significant postoperative elevation seen in the placebo group.

Conclusions

A single infusion of rHDL can acutely alter plasma biomarkers associated with plaque instability and cardiovascular morbidity.

Systematic Review and Meta-analysis of Long-term survival After Elective Infrarenal Abdominal Aortic Aneurysm Repair 1969-2011: 5 Year Survival Remains Poor Despite Advances in Medical Care and Treatment Strategies

Background

Improved critical care, pre-operative optimization, and the advent of endovascular surgery (EVAR) have improved 30 day mortality for elective abdominal aortic aneurysm (AAA) repair. It remains unknown whether this has translated into improvements in long-term survival, particularly because these factors have also encouraged the treatment of older patients with greater comorbidity. The aim of this study was to quantify how 5 year survival after elective AAA repair has changed over time.

Methods

A systematic review was performed identifying studies reporting 5 year survival after elective infrarenal AAA repair. An electronic search of the Embase and Medline databases was conducted to January 2014. Thirty-six studies, 60 study arms, and 107,814 patients were identified. Meta-analyses were conducted to determine 5 year survival and to report whether 5 year survival changed over time.

Results

Five-year survival was 69% (95% CI 67 to 71%, I² = 87%). Meta-regression on study midpoint showed no improvement in 5 year survival over the period 1969–2011 (log OR −0.001, 95% CI −0.014–0.012). Larger average aneurysm diameter was associated with poorer 5 year survival (adjusted log OR −0.058, 95% CI −0.095 to −0.021, I² = 85%). Older average patient age at surgery was associated with poorer 5 year survival (adjusted log OR −0.118, 95% CI −0.142 to −0.094, I² = 70%). After adjusting for average patient age, an improvement in 5 year survival over the period that these data spanned was obtained (adjusted log OR 0.027, 95% CI 0.012 to 0.042).

Conclusion

Five-year survival remains poor after elective AAA repair despite advances in short-term outcomes and is associated with AAA diameter and patient age at the time of surgery. Age-adjusted survival appears to have improved; however, this cohort as a whole continues to have poor long-term survival. Research in this field should attempt to improve the life expectancy of patients with repaired AAA and to optimise patient selection.

Endovascular aneurysm sealing for the treatment of ruptured abdominal aortic aneurysms

Purpose: To assess the feasibility and report preliminary results of ruptured abdominal aortic aneurysm (rAAA) repair with endovascular aneurysm sealing (EVAS), a novel therapeutic alternative whose feasibility has not been established in rAAAs due to the unknown effects of the rupture site on the ability to achieve sealing. Case Report: Between December 2013 and April 2014, 5 patients (median age 71 years, range 57–90; 3 men) with rAAAs were treated with the Nellix EVAS system at a single institution. Median aneurysm diameter was 70 mm (range 67–91). Aneurysm morphology in 4 of the 5 patients was noncompliant with instructions for use (IFU) for both EVAS and standard stent-grafts; the remaining patient was outside the IFU for standard stent-grafts but treated with EVAS under standard IFU for the Nellix system. Median Hardman index was 2 (range 0–3). Two patients died of multiorgan failure after re-laparotomy and intraoperative cardiac arrest, respectively. Among survivors, all devices were patent with no signs of endoleak or failed aneurysm sac sealing at 6 months (median follow-up 9.2 months). Conclusion: EVAS for the management of infrarenal rAAAs appears feasible. The use of EVAS in emergency repairs may broaden the selection criteria of the current endovascular strategy to include patients with more complex aneurysm morphology.

Endovascular aneurysm sealing for infrarenal abdominal aortic aneurysms: 30-day outcomes of 105 patients in a single centre

OBJECTIVE

Endovascular aneurysm sealing (EVAS) has been proposed as a novel alternative to endovascular aneurysm repair (EVAR) in patients with infrarenal abdominal aortic aneurysms (AAA). The early clinical experience, technical refinements, and learning curve of EVAS in the treatment of AAA at a single institution are presented.

METHODS

One-hundred and five patients were treated with EVAS between March 2013 and November 2014. Prospective data were recorded on consecutive patients receiving EVAS. Data included demographics, preoperative aneurysm morphology, and 30-day outcomes, including rates of endoleak, limb occlusion, reintervention, and death. Postoperative imaging consisted of duplex ultrasound and computed tomographic angiography.

RESULTS

The mean age of the cohort was 76 ± 8 years and 12% were female. Adverse neck morphology was present in 72 (69%) patients, including aneurysm neck length <10 mm (20%), neck diameter >32 mm (18%), β-angulation >60° (21%), and conical aneurysm neck (51%). There was one death within 30 days. The incidence of Type 1 endoleak within 30 days was 4% (n = 4); all were treated successfully with transcatheter embolisation. All four proximal endoleaks were associated with technical issues that resulted in procedure refinement, and all were in patients with adverse proximal aortic necks. The persistent Type 1 endoleak rate at 30 days was 0% and there were no Type 2 or Type 3 endoleaks. Angioplasty and adjunctive stenting were performed for postoperative limb stenosis in three patients (3%).

CONCLUSIONS

EVAS appears to be associated with reasonable 30-day outcomes despite the necessity of procedural evolution in the early adoption of this technique. EVAS appears to be applicable to patients with challenging aortic morphology and endoleak rates should reduce with procedural experience. The utility of EVAS will be defined by the durability of the device in long-term follow-up, although the absence of Type 2 endoleaks is encouraging.

Association of hospital structures with mortality from ruptured abdominal aortic aneurysm

BACKGROUND

There is significant variation in the mortality rates of patients with a ruptured abdominal aortic aneurysm (rAAA) admitted to hospital in England. This study sought to investigate whether modifiable differences in hospital structures and processes were associated with differences in patient outcome.

METHODS

Patients diagnosed with rAAA between 2005 and 2010 were extracted from the Hospital Episode Statistics database. After risk adjustment, hospitals were grouped into low-mortality outlier, expected mortality and high-mortality outlier categories. Hospital Trust-level structure and process variables were compared between categories, and tested for an association with risk-adjusted 90-day mortality and non-corrective treatment (palliation) rate using binary logistic regression models.

RESULTS

There were 9877 patients admitted to 153 English NHS Trusts with an rAAA during the study. The overall combined (operative and non-operative) mortality rate was 67·5 per cent (palliation rate 41·6 per cent). Seven hospital Trusts (4·6 per cent) were high-mortality and 15 (9·8 per cent) were low-mortality outliers. Low-mortality outliers used significantly greater mean resources per bed (doctors: 0·922 versus 0·513, P < 0·001; consultant doctors: 0·316 versus 0·168, P < 0·001; nurses: 2·341 versus 1·770, P < 0·001; critical care beds: 0·045 versus 0·019, P < 0·001; operating theatres: 0·027 versus 0·019, P = 0·002) and performed more fluoroscopies (mean 12·6 versus 9·2 per bed; P = 0·046) than high-mortality outlier hospital Trusts. On multivariable analysis, greater numbers of consultants, nurses and fluoroscopies, teaching status, weekday admission and rAAA volume were independent predictors of lower mortality and, excluding rAAA volume, a lower rate of palliation.

CONCLUSION

The variability in rAAA outcome in English National Health Service hospital Trusts is associated with modifiable hospital resources. Such information should be used to inform any proposed quality improvement programme surrounding rAAA.

International validation of a risk score for complications and reinterventions after endovascular aneurysm repair

Background

Lifelong surveillance is considered mandatory after endovascular repair (EVAR) of abdominal aortic aneurysms to detect endograft complications and prevent aneurysm rupture. Current protocols are not cost-effective or clinically effective. The international validity of the St George's Vascular Institute (SGVI) score for EVAR complications was examined.

Methods

The ENGAGE registry recruited patients undergoing EVAR at 79 centres in 30 countries. Reinterventions and endograft complications were recorded for up to 3 years after surgery. Preoperative aneurysm morphology was extracted from the registry database, and used to predict whether patients would be at low or high risk of complications after EVAR based on the SGVI score. Kaplan–Meier analysis was used to compare the incidence of endograft complications and reinterventions in patients predicted to be at low risk compared with those predicted to be at high risk.

Results

Some 1207 patients underwent EVAR, with follow-up of up to 3 years. The SGVI score accurately discriminated freedom from reinterventions (90·5 versus 79·3 per cent in low- versus high-risk patients; P &lt; 0·001), freedom from endograft complications (77·9 versus 69·6 per cent in low- versus high-risk patients; P = 0·012), and freedom from a composite outcome measure of reinterventions or endograft complications (75·0 versus 66·1 per cent in low- versus high-risk patients; P = 0·006) during mid-term follow-up.

Conclusion

This study has provided international validation of a morphological risk score that predicts mid-term reinterventions and endograft complications. The results may enable risk-stratified surveillance after EVAR.

Rationalising cross-match requests in vascular surgery is safe and cost effective

This study describes how a vascular centre rationalised their blood transfusion policy. A multidisciplinary panel reviewed data for blood transfusion protocols and implemented improvements that were analysed. The number of units cross-matched fell from 272 to 183 over a six month period. Unused blood reduced from 80% to 61%. The study concluded that rationalisation of cross matching policies is safe and provides cost and resource benefits.