Observations from the IMPROVE trial concerning the clinical care of patients with ruptured abdominal aortic aneurysm

Qualitative study of clinician and patient perspectives on the mode of anaesthesia for emergency surgery

Background

Although delivering a chosen mode of anaesthesia for certain emergency surgery procedures is potentially beneficial to patients, it is a complex intervention to evaluate. This qualitative study explored clinician and patient perspectives about mode of anaesthesia for emergency surgery.

Methods

Snowball sampling was used to recruit participants from eight National Health Service Trusts that cover the following three emergency surgery settings: ruptured abdominal aortic aneurysms, hip fractures and inguinal hernias. A qualitative researcher conducted interviews with clinicians and patients. Thematic analysis was applied to the interview transcripts.

Results

Interviews were conducted with 21 anaesthetists, 21 surgeons, 14 operating theatre staff and 23 patients. There were two main themes. The first, impact of mode of anaesthesia in emergency surgery, had four subthemes assessing clinician and patient ideas about: context and the ‘best’ mode of anaesthesia; balance in choosing it over others; change and developments in anaesthesia; and the importance of mode of anaesthesia in emergency surgery. The second, tensions in decision‐making about mode of anaesthesia, comprised four subthemes: clinical autonomy and guidelines in anaesthesia; conforming to norms in mode of anaesthesia; the relationship between expertise, preference and patient involvement; and team dynamics in emergency surgery. The results highlight several interlinking factors affecting decision‐making, including expertise, preference, habit, practicalities, norms and policies.

Conclusion

There is variation in practice in choosing the mode of anaesthesia for surgery, alongside debate as to whether anaesthetic autonomy is necessary or results in a lack of willingness to change.

Endovascular Abdominal Aortic Aneurysm Repair: Does Anesthesia Type Matter?

BACKGROUND

Given the various types of anesthesia used for endovascular abdominal aortic aneurysm repair (EVAR), we sought to determine the effect of anesthesia type in the outcomes of elective EVAR in a large multiinstitutional healthcare maintenance organization.

METHODS

A retrospective chart review was conducted on all elective EVAR conducted from August 2010 to August 2017 in 14 regional hospitals of Kaiser Permanente Southern California. Patients undergoing emergent, nonelective abdominal aortic aneurysm repairs, thoracoabdominal aneurysm repair, requiring conversion to open surgery or general anesthesia were excluded from the study. Basic demographic information, medical risk factors, anesthesia type, operative data, and postoperative morbidity and mortality data were obtained for univariate and multivariate statistical analysis.

RESULTS

A total of 1,536 patients underwent EVAR, of which 1,206 met inclusion criteria. A total of 788 patients underwent general anesthesia, 164 patients underwent spinal anesthesia, 82 patients underwent epidural anesthesia, and 172 patients underwent local and monitored anesthesia care (AC). There was a significant difference in length of stay and operative time when comparing local/monitored AC to general anesthesia. No significant difference was noted in 30-day morbidity or mortality among the anesthesia groups.

CONCLUSIONS

Local and regional anesthesia is a safe and effective approach for elective EVAR.

Optimal blood pressure control for patients after thoracic endovascular aortic repair of type B aortic dissection

BACKGROUND

Guidelines recommend tight systolic blood pressure (SBP) control for favorable outcomes of type B aortic dissection (BAD) but are still limited by the optimal cut-off value of SBP. The purpose of this study was to evaluate the optimal cut-off value of SBP in BAD patients after thoracic endovascular aortic repair (TEVAR).

METHODS

From January 2011 to April 2017, 269 consecutive patients with BAD after TEVAR were included in the study. All patients were followed up according to a strict follow-up protocol. Cox regression analysis was used to examine the association between SBP at discharge and 90-day aortic related adverse events (ARAE).

RESULTS

All 269 patients completed 90 days of follow-up, and the unadjusted ARAE-free rates at 90-day was 95.1 ± 1.3%. The cut-off value of SBP at discharge identified by receiver operator curve was 130 mmHg for 90-day ARAE. In multivariable models, binary SBP at discharge was significant associated with 90-day ARAE (HR 3.780; 95% CI 1.236-11.556; p = 0.020). Hybrid operation (OR 2.046; 95%CI 1.015-4.122; p = 0.045) and insertion of ≥2 stents (OR 2.950; 95%CI 1.172-7.426; p = 0.022) were demonstrated to be independently associated with poor SBP control (SBP > 130 mmHg) using Logistic analysis.

CONCLUSIONS

The optimal cut-off value of SBP at discharge was 130 mmHg which can be used to predict short-term ARAE. Blood pressure in patients with hybrid operation and ≥ 2 stents should be given more focus.

Strategy of endovascular versus open repair for patients with clinical diagnosis of ruptured abdominal aortic aneurysm: the IMPROVE RCT

BACKGROUND

Ruptured abdominal aortic aneurysm (AAA) is a common vascular emergency. The mortality from emergency endovascular repair may be much lower than the 40-50% reported for open surgery.

OBJECTIVE

To assess whether or not a strategy of endovascular repair compared with open repair reduces 30-day and mid-term mortality (including costs and cost-effectiveness) among patients with a suspected ruptured AAA.

DESIGN

Randomised controlled trial, with computer-generated telephone randomisation of participants in a 1 : 1 ratio, using variable block size, stratified by centre and without blinding.

SETTING

Vascular centres in the UK (n = 29) and Canada (n = 1) between 2009 and 2013.

PARTICIPANTS

A total of 613 eligible participants (480 men) with a ruptured aneurysm, clinically diagnosed at the trial centre.

INTERVENTIONS

A total of 316 participants were randomised to the endovascular strategy group (immediate computerised tomography followed by endovascular repair if anatomically suitable or, if not suitable, open repair) and 297 were randomised to the open repair group (computerised tomography optional).

MAIN OUTCOME MEASURES

The primary outcome measure was 30-day mortality, with 30-day reinterventions, costs and disposal as early secondary outcome measures. Later outcome measures included 1- and 3-year mortality, reinterventions, quality of life (QoL) and cost-effectiveness.

RESULTS

The 30-day mortality was 35.4% in the endovascular strategy group and 37.4% in the open repair group [odds ratio (OR) 0.92, 95% confidence interval (CI) 0.66 to 1.28; p = 0.62, and, after adjustment for age, sex and Hardman index, OR 0.94, 95% CI 0.67 to 1.33]. The endovascular strategy appeared to be more effective in women than in men (interaction test p = 0.02). More discharges in the endovascular strategy group (94%) than in the open repair group (77%) were directly to home (p < 0.001). Average 30-day costs were similar between groups, with the mean difference in costs being -£1186 (95% CI -£2997 to £625), favouring the endovascular strategy group. After 1 year, survival and reintervention rates were similar in the two groups, QoL (at both 3 and 12 months) was higher in the endovascular strategy group and the mean cost difference was -£2329 (95% CI -£5489 to £922). At 3 years, mortality was 48% and 56% in the endovascular strategy group and open repair group, respectively (OR 0.73, 95% CI 0.53 to 1.00; p = 0.053), with a stronger benefit for the endovascular strategy in the subgroup of 502 participants in whom repair was started for a proven rupture (OR 0.62, 95% CI 0.43 to 0.89; p = 0.009), whereas aneurysm-related reintervention rates were non-significantly higher in this group. At 3 years, considering all participants, there was a mean difference of 0.174 quality-adjusted life-years (QALYs) (95% CI 0.002 to 0.353 QALYs) and, among the endovascular strategy group, a cost difference of -£2605 (95% CI -£5966 to £702), leading to 88% of estimates in the cost-effectiveness plane being in the quadrant showing the endovascular strategy to be 'dominant'.

LIMITATIONS

Because of the pragmatic design of this trial, 33 participants in the endovascular strategy group and 26 in the open repair group breached randomisation allocation.

CONCLUSIONS

The endovascular strategy was not associated with a significant reduction in either 30-day mortality or cost but was associated with faster participant recovery. By 3 years, the endovascular strategy showed a survival and QALY gain and was highly likely to be cost-effective. Future research could include improving resuscitation for older persons with circulatory collapse, the impact of local anaesthesia and emergency consent procedures.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN48334791 and NCT00746122.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 31. See the NIHR Journals Library website for further project information.

Local anaesthesia for endovascular repair of ruptured abdominal aortic aneurysm

BACKGROUND

Case series and a post hoc subgroup analysis of a large randomized trial have suggested a potential benefit in treating ruptured abdominal aortic aneurysms (rAAAs) using endovascular aneurysm repair (EVAR) with local anaesthesia (LA) rather than general anaesthesia (GA). The uptake and outcomes of LA in clinical practice remain unknown.

METHODS

The UK National Vascular Registry was interrogated for patients presenting with rAAA managed with EVAR under different modes of anaesthesia between 1 January 2014 and 31 December 2016. The primary outcome was in-hospital mortality. Secondary outcomes included: the number of centres performing EVAR under LA; the proportion of patients receiving this technique; duration of hospital stay; and postoperative complications.

RESULTS

Some 3101 patients with rAAA were treated in 72 hospitals during the study: 2306 underwent on open procedure and 795 had EVAR (LA, 319; GA, 435; regional anaesthesia, 41). Overall, 56 of 72 hospitals (78 per cent) offered LA for EVAR of rAAA. Baseline characteristics and morphology were similar across the three EVAR subgroups. Patients who had surgery under LA had a lower in-hospital mortality rate than patients who received GA (59 of 319 (18·5 per cent) versus 122 of 435 (28·0 per cent)), and this was unchanged after adjustment for factors known to influence survival (adjusted hazard ratio 0·62, 95 per cent c.i. 0·45 to 0·85; P = 0·003). Median hospital stay and postoperative morbidity from other complications were similar.

CONCLUSION

The use of LA for EVAR of rAAA has been adopted widely in the UK. Mortality rates appear lower than in patients undergoing EVAR with GA.

Simulation training streamlines the real-life performance in endovascular repair of ruptured abdominal aortic aneurysms

OBJECTIVE

Difficulties in distributing endovascular experience among all operating room (OR) personnel prevented full-scale use of endovascular aneurysm repair (EVAR) in emergencies. To streamline the procedure of EVAR for ruptured aneurysm (rEVAR) and to provide this method even to unstable patients, we initiated regular simulation training sessions.

METHODS

This is an observational study of 29 simulation sessions performed between January 2015 and December 2017. We analyzed the development of time from OR door to aortic balloon occlusion during simulations and OR door to needle times in real-life rEVARs as well as the outcome of the 185 ruptured abdominal aortic aneurysm (rAAA) patients who arrived at the university hospital between January 2013 and December 2017. A questionnaire was sent for simulation attendants before and after the simulation session.

RESULTS

In the first simulations, the door to occlusion time was 20 to 35 minutes. After adding a hemodynamic collapse to the simulation protocol, the time decreased to 10 to 13 minutes in the 10 recent simulations, including a 5-minute cardiopulmonary resuscitation (P = .01). The electronic questionnaire performed for attendees before and after the simulation session showed significant improvement in both confidence and knowledge of the OR staff regarding rEVAR procedure. In the real-life rEVARs, 75 of the 185 patients with rAAAs underwent EVAR. Among rEVAR patients, the median OR door to needle time was 65 minutes before and 16 minutes after the onset of simulations (P = .000). The overall 30-day mortality among all rAAA patients was 44.8% and 30.6% accordingly (P = .046). When patients who were turned down from the emergency surgery were excluded, the 30-day operative mortality was 39.2% and 25.1% during the periods, respectively (P = .051). The 30-day mortality was 16.2% after rEVAR and 40.6% after open surgery (P = .001).

CONCLUSIONS

Simulation training for rEVAR significantly improves the treatment process in real-life patients and may enhance the outcome of rAAA patients.

Effectiveness of arginine vasopressin for the management of refractory hemorrhagic shock in a patient with autonomic dysreflexia caused by spinal cord injury

Background

Arginine vasopressin has been used for the management of refractory vasodilatory shock. However, it is still unclear whether arginine vasopressin is useful for hypotension in patients with spinal cord injury.

Case description

A 78-year-old man with autonomic dysreflexia and paralysis below the level corresponding to Th2 due to spinal cord injury previously underwent cholecystectomy. During the surgery, accidental hemorrhage led him to refractory hemorrhagic shock unresponsive to fluid resuscitation and catecholamine. Lasting hypotension was improved with arginine vasopressin.

Conclusion

We described a rare case report on the use of arginine vasopressin for management of refractory hemorrhagic shock in a patient with autonomic dysreflexia.

Open Versus Endovascular Repair of Isolated Iliac Artery Aneurysms

PURPOSE:

Outcomes of open iliac artery repair (OIR) and endovascular iliac artery repair (EVIR) were compared at a tertiary referral vascular center.

METHODS:

From 2004 to 2015, all patients treated for isolated iliac artery aneurysms (IAAs) were retrospectively identified, and patient records and computed tomography (CT) scans were analyzed. The primary end point was overall survival; secondary end points were 30-day mortality and morbidity and freedom from reintervention. For follow-up, data from outpatient visits and CT scans following a standard surveillance protocol were used.

RESULTS:

A total of 106 IAAs in 94 patients were treated (mean follow-up: 35.7 months; 66 OIR; 40 EVIR). Six (15%) aneurysms from the EVIR group and 4 (6.1%) from open-operated IAA presented in the state of rupture. There was no difference in overall survival between EVIR and OIR ( P = .14). In multivariable analysis, higher risk of death was associated with ruptured IAA (rIAA; hazard ratio [HR]: 40.44, 95% confidence interval [CI]: 2.05-796.18; P = .02) and coronary heart disease (HR: 11.07, 95% CI: 1.94-63.36; P < .01). The 30-day mortality was 1.9% overall (0% OIR, 5.0% EVIR, P = .27), but there were no differences between OIR and EVIR in 30-day morbidity ( P = .11). Freedom from reintervention was higher for OIR than for EVIR ( P < .01). In multivariable analysis, a higher reintervention rate was seen in EVIR (HR: 10.80, 95% CI: 2.20-53.01; P < .01) and in rIAA (HR: 12.02, 95% CI: 1.31-111.11; P = .03).

CONCLUSION:

Iliac artery aneurysmss can be safely and effectively treated by EVIR or OIR regarding 30-day morbidity, mortality, and long-term survival, although freedom from reintervention is significantly lower after EVIR.

Controlled hypotension versus normotensive resuscitation strategy for people with ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) is the pathological enlargement of the aorta and can develop in both men and women. Progressive aneurysm enlargement can lead to rupture. The rupture of an AAA is frequently fatal and accounts for the death from haemorrhagic shock of at least 45 people per 100,000 population. The outcome of people with ruptured AAA varies among countries and healthcare systems, with mortality ranging from 53% to 90%. Definitive treatment for ruptured AAA includes open surgery or endovascular repair. The management of haemorrhagic shock is crucial for the person's outcome and aims to restore organ perfusion and systolic blood pressure above 100 mmHg through immediate and aggressive fluid replacement. This rapid fluid replacement is known as the normotensive resuscitation strategy. However, evidence suggests that infusing large volumes of cold fluid causes dilutional and hypothermic coagulopathy. The association of these factors may exacerbate bleeding, resulting in a 'lethal triad' of hypothermia, acidaemia, and coagulopathy. An alternative to the normotensive resuscitation strategy is the controlled (permissive) hypotension resuscitation strategy, with a target systolic blood pressure of 50 mmHg to 100 mmHg. The principle of controlled or hypotensive resuscitation has been used in some management protocols for endovascular repair of ruptured AAA. It may be beneficial in preventing blood loss by avoiding the clot disruption caused by the rapid increase in systolic blood pressure; avoiding dilution of clotting factors, platelets and fibrinogen; and by avoiding the temperature decrease that inhibits enzyme activity involved in platelet and clotting factor function. This is an update of a review first published in 2016.

OBJECTIVES

To compare the effects of controlled (permissive) hypotension resuscitation and normotensive resuscitation strategies for people with ruptured AAA.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Specialised Register (August 2017), the Cochrane Register of Studies (CENTRAL (2017, Issue 7)) and EMBASE (August 2017). The Cochrane Vascular Information Specialist also searched clinical trials databases (August 2017) for details of ongoing or unpublished studies.

SELECTION CRITERIA

We sought all published and unpublished randomised controlled trial (RCTs) that compared controlled hypotension and normotensive resuscitation strategies for the management of shock in patients with ruptured abdominal aortic aneurysms.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified studies for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no RCTs that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We found no RCTs that compared controlled hypotension and normotensive resuscitation strategies in the management of haemorrhagic shock in patients with ruptured abdominal aortic aneurysm that assessed mortality, presence of coagulopathy, intensive care unit length of stay, and the presence of myocardial infarct and renal failure. High quality studies that evaluate the best strategy for managing haemorrhagic shock in ruptured abdominal aortic aneurysms are required.

Endovascular or open repair for ruptured abdominal aortic aneurysm?

The endovascular approach is better for patients and more cost effective for payers

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (pathological enlargement of the aorta) is a condition that can occur as a person ages. It is most commonly seen in men older than 65 years of age. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, which is fatal unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. Endovascular aneurysm repair (EVAR), a minimally invasive technique, has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. More recently emergency endovascular aneurysm repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in select patients; however, it is unclear if eEVAR will lead to significant improvements in outcomes for these patients or if indeed it can replace conventional open repair as the preferred treatment for this lethal condition. This is an update of the review first published in 2006.

OBJECTIVES

To assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by comparing the effects of eEVAR and conventional open surgical repair on short-term mortality, major complication rates, aneurysm exclusion (specifically endoleaks in the eEVAR treatment group), and late complications.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (last searched June 2016), CENTRAL (2016, Issue 5), and trials registries. We also checked reference lists of relevant publications.

SELECTION CRITERIA

Randomised controlled trials in which participants with a clinically or radiologically diagnosed RAAA were randomly allocated to eEVAR or conventional open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified for potential inclusion for eligibility. Two review authors also independently completed data extraction and quality assessment. Disagreements were resolved through discussion. We performed meta-analysis using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data.

MAIN RESULTS

We included four randomised controlled trials in this review. A total of 868 participants with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low, but we considered one study that performed randomisation in blocks by week and performed no allocation concealment and no blinding to be at high risk of selection bias. Another study did not adequately report random sequence generation, putting it at risk of selection bias, and two studies were underpowered. There was no clear evidence to support a difference between the two interventions for 30-day (or in-hospital) mortality (OR 0.88, 95% CI 0.66 to 1.16; moderate-quality evidence). There were a total of 44 endoleak events in 128 participants from three studies (low-quality evidence). Thirty-day complication outcomes (myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation, and respiratory failure) were reported in between one and three studies, therefore we were unable to draw a robust conclusion. We downgraded the quality of the evidence for myocardial infarction, renal complications, and respiratory failure due to imprecision, inconsistency, and risk of bias. Odds ratios for complications outcomes were OR 2.38 (95% CI 0.34 to 16.53; 139 participants; 2 studies; low-quality evidence) for myocardial infarction; OR 1.07 (95% CI 0.21 to 5.42; 255 participants; 3 studies; low-quality evidence) for renal complications; and OR 3.62 (95% CI 0.14 to 95.78; 32 participants; 1 study; low-quality evidence) for respiratory failure. There was low-quality evidence of a reduction in bowel ischaemia in the eEVAR treatment group, but very few events were reported (OR 0.37, 95% CI 0.14 to 0.94), and we downgraded the evidence due to imprecision and risk of bias. Six-month and one-year outcomes were evaluated in three studies, but only results from a single study could be used for each outcome, which showed no clear evidence of a difference between the interventions. We rated six-month mortality evidence as of moderate quality due to imprecision (OR 0.89, 95% CI 0.40 to 1.98; 116 participants).

AUTHORS' CONCLUSIONS

The conclusions of this review are currently limited by the paucity of data. We found from the data available moderate-quality evidence suggesting there is no difference in 30-day mortality between eEVAR and open repair. Not enough information was provided for complications for us to make a well-informed conclusion, although it is possible that eEVAR is associated with a reduction in bowel ischaemia. Long-term data were lacking for both survival and late complications. More high-quality randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Intensive blood pressure control in patients with acute type B aortic dissection (RAID): study protocol for randomized controlled trial

BACKGROUND

Blood pressure control is an essential therapy for patients with acute type B aortic dissection (ABAD) and should be maintained throughout the entire treatment. Thus, vast majority current guidelines recommend control the blood pressure to lower than 140/90 mmHg. Theoretically, a much lower target may further decrease the risk of propagation of dissection. However, some argued that too lower blood pressure would compromise the organ perfusion. Thus, there is no unanimous optimal target for blood pressure in patients with ABAD so far. The present study aimed to investigate the optimal blood pressure target for patients with ABAD, in the hope that the result would optimize the treatment of aortic dissection (AD).

METHODS

The study is a multi-center randomized controlled clinical trial. Study population will include patients with new diagnosed ABAD and hypertension. Blocked randomization was performed where intensive blood pressure control (<120 mmHg) with conventional blood pressure control (<140 mmHg) were allocated at random in a ratio of 1:1 in blocks of sizes 4, 6, 8, and 10 to 360 subjects. Interim analysis will be performed. The primary outcome is a composite in-hospital adverse outcome, including death, permanent paraplegia or semi- paralysis during the hospitalization, and renal failure requiring hemodialysis at discharge. While the secondary outcomes include the aortic size, lower extremity or visceral ischemia, retrograde propagation into aortic arch or ascending aorta, mortality in 6 months and 1 year, intensive care unit (ICU) length of stay, total length of hospital stay, creatinine level, and surgical or endovascular intervention.

ETHICS AND DISSEMINATION

The study was approved by the institutional review board of Sir Run Run Shaw Hospital (approval number: 20160920-9). Informed consent will be obtained from participants or their next-of-kin. The results will be published in a peer-reviewed journal and shared with the worldwide medical community.

TRIAL REGISTRATION

NCT03001739 (https://register.clinicaltrials.gov/).

Ambulance smartphone tool for field triage of ruptured aortic aneurysms (FILTR): study protocol for a prospective observational validation of diagnostic accuracy

INTRODUCTION

Rupture of an abdominal aortic aneurysm (rAAA) carries a considerable mortality rate and is often fatal. rAAA can be treated through open or endovascular surgical intervention and it is possible that more rapid access to definitive intervention might be a key aspect of improving mortality for rAAA. Diagnosis is not always straightforward with up to 42% of rAAA initially misdiagnosed, introducing potentially harmful delay. There is a need for an effective clinical decision support tool for accurate prehospital diagnosis and triage to enable transfer to an appropriate centre.

METHODS AND ANALYSIS

Prospective multicentre observational study assessing the diagnostic accuracy of a prehospital smartphone triage tool for detection of rAAA. The study will be conducted across London in conjunction with London Ambulance Service (LAS). A logistic score predicting the risk of rAAA by assessing ten key parameters was developed and retrospectively validated through logistic regression analysis of ambulance records and Hospital Episode Statistics data for 2200 patients from 2005 to 2010. The triage tool is integrated into a secure mobile app for major smartphone platforms. Key parameters collected from the app will be retrospectively matched with final hospital discharge diagnosis for each patient encounter. The primary outcome is to assess the sensitivity, specificity and positive predictive value of the rAAA triage tool logistic score in prospective use as a mob app for prehospital ambulance clinicians. Data collection started in November 2014 and the study will recruit a minimum of 1150 non-consecutive patients over a time period of 2 years.

ETHICS AND DISSEMINATION

Full ethical approval has been gained for this study. The results of this study will be disseminated in peer-reviewed publications, and international/national presentations.

TRIAL REGISTRATION NUMBER

CPMS 16459; pre-results.

The Significance of Hypothermia in Abdominal Aortic Aneurysm Repair

BACKGROUND

The aim of this study was to review the literature on the association between hypothermia and outcomes in open and endovascular abdominal aortic aneurysm (AAA) repair. The secondary aim was to determine whether there is a difference in body temperature in patients undergoing either transperitoneal (TP), retroperitoneal (RP), or endovascular surgical repair of the abdominal aorta (EVAR).

METHODS

MEDLINE, Web of Science, and Trip searched for all studies on temperature in the context of aortic surgery or endovascular aortic interventions. To be included in the review, the papers had to be related to intraoperative or postoperative hypothermia and/or normothermia, with regards to either open or endovascular repair of the abdominal aorta. Thoracic or thoracoabdominal aortic repairs were not included for review.

RESULTS

Eight studies involving 765 patients were eligible. Of these, 6 studies looked at open elective AAA repair involving 605 patients. Only 2 studies investigated emergency AAA repair and consisted of 160 patients where only 35 of those patients underwent emergency EVAR. Normothermic patients had a shorter length of stay in the intensive care unit (P = 0.0008), while hypothermia was independently associated with higher rates of organ dysfunction, in-hospital mortality, and prolonged hospital length of stay. In ruptured AAAs, the lowest average intraoperative temperature was recorded in open repair compared with EVAR (P = 0.02). There was no statistically significant difference in postoperative temperature between patients undergoing elective RP repair and those having TP surgery.

CONCLUSIONS

The studies identified in this review have shown that hypothermia has numerous deleterious effects on outcomes in AAA repair - whether or not these adverse outcomes are those such as higher rates of organ dysfunction, mortality or prolonged hospital length of stay, can only be done at the single paper level and not at a literature review level, due to multiple confounding variables. Despite these limitations, the benefits of this review are numerous. This article highlights the importance of core body temperature and outcomes of AAA repair. Furthermore, it brings forth the need to standardize the method of core body temperature measurement and method of rewarming. Given the body of evidence so far, these standardized data collection points will be important for national vascular quality improvement initiatives. Only through rigorous analysis of standardized dataset can firm recommendation regarding peri- and postoperative temperature management be made.

Outcomes of regional transfers of ruptured abdominal aortic aneurysm in a UK vascular network

INTRODUCTION Rupture of abdominal aortic aneurysm is a surgical emergency. In order to improve operative outcomes, vascular services have been centralised in the United Kingdom. This means that a patient may present to a hospital with a ruptured aneurysm, but require transfer to a vascular centre for definitive treatment. METHODS This retrospective cohort study identified patients who underwent surgery for ruptured abdominal aortic aneurysm in a tertiary vascular centre over a 2-year period. Data on demographics and originating unit were recorded. Outcomes assessed included 30-day mortality, operative mortality and postoperative morbidity. RESULTS We identified 70 patients who underwent surgery for ruptured abdominal aortic aneurysm in the 2-year period; 36 presented directly to the vascular unit (VU), 14 to referral unit 1 (RU1) and 20 to referral unit 2 (RU2); 30-day mortality rates were 27.7% (VU), 35.5% (RU1) and 30.0% (RU2), respectively. There was no statistical difference in mortality between units. Postoperative complications were seen in 35.9% of VU patients, 78.6% of RU1 patients and 70% of RU2 patients. This was statistically significant between VU and RU1 (P = 0.006) and VU and RU2 (P = 0.02). Direct operative complications were seen in 9 patients, gastrointestinal complications in 9, limb complications in 6 and systemic complications in 40. CONCLUSION This study found that site of presentation does not affect mortality but is associated with increased morbidity. This is a complex issue, which will require a prospective multicentre study to investigate further.

Clinical outcomes of infrarenal abdominal aortic aneurysms that underwent endovascular repair in a district general hospital

BACKGROUND

The purpose of this study was to compare the outcomes of elective endovascular abdominal aortic aneurysm repair (EVAR) and ruptured abdominal aortic aneurysm (rAAA) in patients at a district general hospital.

METHODS

A retrospective clinical study was conducted using data on 16 patients with elective abdominal aortic aneurysm (AAA) and nine patients with consecutive rAAA treated with EVAR from January 2010 to December 2014 in a district general hospital in Taiwan.

RESULTS

The preoperative characteristics of the two groups are listed. Thirty-six percent (9/25) of the patients were referred from other hospitals that did not offer surgical services. The percentage of patients with rAAA that were transferred from other hospitals was 55.5% (5/9). The stay durations in the intensive care unit for elective EVAR cases were shorter than those for emergent EVAR (1.75±1 d elective vs. 10±13.37 d emergent; P<0.019). The hospitalization days (11.06±4.07 d elective vs. 21.89±18.36 d emergent; P<0.031), operative time (183.63±57.24 min elective vs. 227.11±59.92 min emergent; P<0.009), and blood loss volumes (115.63±80.41 mL elective vs. 422.22±276.26 mL emergent; P<0.005) are shown; statistics for use of Perclose ProGlide(®) (7 cases elective vs. 0 case emergent; P<0.024) are compared. The overall 30-d mortality rate was 11.11% (1/9).

CONCLUSIONS

The results confirm that EVAR surgery can be safely performed in a district general hospital with an integrated health care system. Using Perclose ProGlide(®) for selected cases may reduce blood loss and operative time.

Transition from Open Surgery to Endovascular Treatment of Abdominal Aortic Aneurysm Rupture

BACKGROUND

To review the outcome before and after the implementation of protocol-based strategy for endovascular repair (EVAR) of abdominal aortic aneurysm rupture (rAAA).

METHODS

A retrospective analysis of prospectively collected data from a tertiary center during the period 2006-2011. Demographics, comorbidities, blood examinations, perioperative patients' status, and mortality rates were recorded. Univariate and multivariate analyses were used to assess the association of the type of the procedure with various factors.

RESULTS

A total of 58 (46 open surgical repair [OSR] and 12 EVAR) patients with mean age of 74 ± 17 years (91% males) were treated for rAAA. However, 39 (11 EVAR and 28 OSR) were operated with protocol-based strategy available. Total mortality rate was 52.6% (10 of 19) initially and 38.5% (15 of 39) after the implementation of a protocol-based strategy. During protocol-based treatment, the survival rate did not differ between the 2 procedures (7 of 11 EVAR and 17 of 28 OSR; P, ns). A 30-day mortality rate was associated with preoperative number of platelets (unadjusted P values, P = 0.013), age (odds ratio [OR] 0.796; 95% confidence interval [CI], 0.685-0.925; P = 0.003), and diastolic blood pressure (OR, 1.053; 95% CI, 1.016-1.093; P = 0.005). After mean follow-up of 48 ± 11 months, EVAR patients presented better outcome regarding mortality rate (36% OSR vs. 0% EVAR; P = 0.0464).

CONCLUSIONS

After the adoption of an available rEVAR protocol-based strategy, EVAR and OSR were equally effective during postoperative 30 days. The role of hypotension and age is important on poor outcomes during this period. However, after midterm follow-up, EVAR demonstrates better survival rates than OSR.

Risk factors for ischaemic colitis after surgery for abdominal aortic aneurysm: a systematic review and observational meta-analysis

BACKGROUND

Ischaemic colitis is an infrequent but serious complication following repair of abdominal aortic aneurysm (AAA), with high mortality rates. This systematic review set out to identify risk factors for the development of ischaemic colitis after AAA surgery.

METHODS

A systematic search of the MEDLINE, EMBASE and CINAHL databases was performed. This search was limited to studies published in the English language after 1990. Abstracts were screened by two authors. Eligible studies were obtained as full text for further examination. Data was extracted by two authors, and any disputes were resolved via consensus. Extracted data was pooled using Mantel-Haenszel random effects models. Bias was assessed using two Cochrane-approved tools. Effect sizes are expressed as relative risk ratios alongside the 95 % confidence interval. Statistical significance was defined at the level of p < 0.05.

RESULTS

From 388 studies identified in the initial search, 33 articles were included in the final synthesis and analysis. Risk factors were grouped into patient (female gender, disease severity) and operative factors (peri-procedural hypotension, operative modality). The risk of ischaemic colitis was significantly higher when undergoing emergency repair versus elective (risk ratio (RR) 7.36, 3.08 to 17.58, p < 0.001). Endovascular repair reduced the likelihood of ischaemic colitis (RR 0.22, 0.12 to 0.39, p < 0.001).

DISCUSSION

The quality of published evidence on this subject is poor with many retrospective datasets and inconsistent reporting across studies. Despite this, emergency presentation and open repair should prompt close monitoring for the development of IC.

Controlled hypotension versus normotensive resuscitation strategy for people with ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) is the pathological enlargement of the aorta and can develop in both men and women. Progressive aneurysm enlargement can lead to rupture. The rupture of an AAA is frequently fatal and accounts for the death from haemorrhagic shock of at least 45 people per 100,000 population. The outcome of people with ruptured AAA varies among countries and healthcare systems, with mortality ranging from 53% to 90%. Definitive treatment for ruptured AAA includes open surgery or endovascular repair. The management of haemorrhagic shock is crucial for the person's outcome and aims to restore organ perfusion and systolic blood pressure above 100 mm Hg through immediate and aggressive fluid replacement. This rapid fluid replacement is known as the normotensive resuscitation strategy. However, evidence suggests that infusing large volumes of cold fluid causes dilutional and hypothermic coagulopathy. The association of these factors may exacerbate bleeding, resulting in a 'lethal triad' of hypothermia, acidaemia, and coagulopathy. An alternative to the normotensive resuscitation strategy is the controlled (permissive) hypotension resuscitation strategy, with a target systolic blood pressure of 50 to 100 mm Hg. The principle of controlled or hypotensive resuscitation has been used in some management protocols for endovascular repair of ruptured AAA. It may be beneficial in preventing blood loss by avoiding the clot disruption caused by the rapid increase in systolic blood pressure; avoiding dilution of clotting factors, platelets and fibrinogen; and by avoiding the temperature decrease that inhibits enzyme activity involved in platelet and clotting factor function.

OBJECTIVES

To compare the effects of controlled (permissive) hypotension resuscitation and normotensive resuscitation strategies for people with ruptured AAA.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Specialised Register (April 2016) and the Cochrane Register of Studies (CENTRAL (2016, Issue 3)). Clinical trials databases were searched (April 2016) for details of ongoing or unpublished studies.

SELECTION CRITERIA

We sought all published and unpublished randomised controlled trial (RCTs) that compared controlled hypotension and normotensive resuscitation strategies for the management of shock in patients with ruptured abdominal aortic aneurysms.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified studies for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no RCTs that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We found no RCTs that compared controlled hypotension and normotensive resuscitation strategies in the management of haemorrhagic shock in patients with ruptured abdominal aortic aneurysm that assessed mortality, presence of coagulopathy, intensive care unit length of stay, and the presence of myocardial infarct and renal failure. High quality studies that evaluate the best strategy for managing haemorrhagic shock in ruptured abdominal aortic aneurysms are required.

Current treatment strategies for ruptured abdominal aortic aneurysm

BACKGROUND

Ruptured abdominal aortic aneurysm (rAAA) represents one of the most challenging emergencies in surgery. Open repair (OR) is associated with relevant morbidity and mortality and has not been reduced significantly over the last decade. The introduction of endovascular aneurysm repair (EVAR) and its meanwhile common use in the treatment of rAAA has raised the demand for randomised controlled trials (RCTs) in order to resolve a potential superiority of either OR or EVAR.

PURPOSE

This review discusses the current treatment strategies in rAAA repair including diagnostics, peri-operative management and results of OR and EVAR, focussing on RCTs comparing both modalities.

RESULTS

Thirty-day mortality after OR and EVAR shows no significant difference in published RCTs. In particular with respect to OR, 30-day mortality was much lower than anticipated throughout all RCTs ranging from 18 to 37 %. EVAR for rAAA resulted in reduced in-hospital stay. Limitations of all except one RCT are low patient recruitment and exclusion of haemodynamically unstable patients.

CONCLUSIONS

OR and EVAR need to be provided for rAAA. Despite lacking evidence, EVAR is the first choice treatment in experienced high-volume vascular centres. Low mortality rates in all RCTs raise the question if aortic surgery should be centralised.

Presenting Baseline Coagulation of Infra Renal Ruptured Abdominal Aortic Aneurysm: A Systematic Review and Pooled Analysis

BACKGROUND

The incidence of coagulopathy in patients presenting with rAAA is not clear. The lack of high-quality evidence has led to various speculations, reliance on anecdotal experience, and suggestions about their appropriate haemostatic resuscitation. The aim of this systematic review is to establish the baseline coagulation status of infra renal ruptured abdominal aortic aneurysms (rAAA) against defined standards and definitions.

METHODS

An electronic search of literature in Medline, CINHAL, Scopus Embase, and Cochrane library was performed in accordance with the PRISMA guidelines. Quality assessment of articles was performed using the Oxford critical appraisal skills programme (CASP) and their recommendation for practice was examined through National Institute for Health and Care Excellence (NICE). Information on platelet count, international normalisation ratio (INR), activated partial prothrombin time (aPTT), prothrombin time (PT) fibrinogen and D-dimer was extracted, and pooled analysis was performed in accordance with the definition of coagulopathy and its subtypes. Pooled prevalence of coagulopathies and 95% CI were estimated with a variance weighted random effects model.

RESULTS

Seven studies, comprising 461 patients were included in this systematic review. Overall weighted prevalence of coagulopathy was 12.3% (95% CI 10.7-13.9), 11.7% for INR (95% CI 1-31.6), 10.1% for platelet count (95% CI 1-26.8), and 11.1% for aPTT (95% CI 0.78-31). Fibrinogen serum concentration level was normal in 97%, and 46.2% (n = 55) of patients had elevated D-dimer. Only 6% of the entire population demonstrated significant coagulopathy. DIC was noted in 2.4% of the population.

CONCLUSION

This first systematic review of literature on baseline coagulation of rAAAs suggests that the majority of these patients do not present with coagulopathy and only a minor proportion of patients present with significant coagulopathy.

Endovascular repair or open repair for ruptured abdominal aortic aneurysm: a Cochrane systematic review

OBJECTIVES

Emergency endovascular aneurysm repair (eEVAR) may improve outcomes for patients with ruptured abdominal aortic aneurysm (RAAA). The study aim was to compare the outcomes for eEVAR with conventional open surgical repair for the treatment of RAAA.

SETTING

A systematic review of relevant publications was performed. Randomised controlled trials (RCTs) comparing eEVAR with open surgical repair for RAAA were included.

PARTICIPANTS

3 RCTs were included, with a total of 761 patients with RAAA.

INTERVENTIONS

Meta-analysis was performed with fixed-effects models with ORs and 95% CIs for dichotomous data and mean differences with 95% CIs for continuous data.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was short-term mortality. Secondary outcome measures included aneurysm-specific and general complication rates, quality of life and economic analysis.

RESULTS

Overall risk of bias was low. There was no difference between the 2 interventions on 30-day (or in-hospital) mortality, OR 0.91 (95% CI 0.67 to 1.22; p=0.52). 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation and respiratory failure. Reporting was incomplete, and no robust conclusion was drawn. For complication outcomes that did include at least 2 studies in the meta-analysis, there was no clear evidence to support a difference between eEVAR and open repair. Longer term outcomes and cost per patient were evaluated in only a single study, thus precluding definite conclusions.

CONCLUSIONS

Outcomes between eEVAR and open repair, specifically 30-day mortality, are similar. However, further high-quality trials are required, as the paucity of data currently limits the conclusions.

WSES position paper on vascular emergency surgery

Trauma, both blunt and penetrating, is extremely common worldwide, as trauma to major vessels. The management of these patients requires specialized surgical skills and techniques of the trauma surgeon. Furthermore few other surgical emergencies require immediate diagnosis and treatment like a ruptured abdominal aortic aneurysm (rAAA). Mortality of patients with a rAAA reaches 85 %, with more than half dying before reaching the hospital. These are acute events demanding immediate intervention to save life and limb and precluding any attempt at transfer or referral. It is the purpose of this position paper to discuss neck, chest, extremities and abdominal trauma, bringing to light recent evidence based data as well as expert opinions; besides, in this paper we present a review of the recent literature on rAAA and we discuss the rationale for transfer to referral center, the role of preoperative imaging and the pros and cons of Endoluminal repair of rAAA (REVAR) versus Open Repair (OR).

Emerging strategies to treat ruptured abdominal aortic aneurysms

Population screening programmes and a falling population prevalence of smoking have led to a declining incidence of ruptured abdominal aortic aneurysms in men. However, ruptured abdominal aortic aneurysms remain a common vascular surgical emergency, with an increasing proportion of ruptures being in women. About one quarter of the ruptures have a juxta-renal aneurysm and are more challenging to repair using endovascular technologies. Endovascular technologies may not reduce the overall mortality, compared with open surgical repair, but appear to offer early benefits with respect to patient quality of life at acceptable cost. Challenges over the next 5 years include widening the access to repair, developing an accurate bedside risk scoring tool, as well as optimising strategies for pre-operative resuscitation, standardising peri-operative care and the management of post-operative complications.