A 12-year experience of endovascular repair for ruptured abdominal aortic aneurysms in all patients.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has been increasingly performed for ruptured abdominal aortic aneurysms (rAAAs). However, multiple randomized trials have failed to demonstrate a survival benefit compared with open aortic surgery. During a 12-year period, 100% of patients without a history of aneurysm surgery had undergone EVAR for a rAAA at Örebro University Hospital, with no emergent open aortic surgery performed. In the present study, we evaluated the mortality and technical success during this "EVAR-only" period. METHODS: A single-center, retrospective observational study was conducted. We identified all patients who had presented to Örebro University Hospital with a rAAA between October 2009 and September 2021. Patients with isolated iliac artery, thoracic, and thoracoabdominal aortic ruptures were not included. Patients who had received previous aortic interventions (open or endovascular) and patients who had received palliative treatment instead of surgical intervention were also excluded. The patient characteristics, perioperative and postoperative data, and mortality rate were investigated. RESULTS: EVAR had been performed in 100 patients. Preoperative hemodynamic instability had been present in 54 patients (54%), and 18 (18%) had undergone aortic balloon occlusion. The aneurysm location was infrarenal in 89 patients (89%). Bifurcated stent grafts had been used in 97 patients (97%), and adjunct endovascular techniques had been used for 27 patients (27%). Of 98 patients, EVAR had been performed with the patient under local anesthesia for 62 patients (63%). Peri- and postoperative complications at 30 days had occurred in 20 of 100 patients (20%) and 22 of 79 patients (28%), respectively. The overall mortality at 30 days was 27% (27 of 100 patients), and the mortality for those with an isolated infrarenal rAAA was 24% (21 of 89 patients). The overall mortality at 1 year was 39% (39 of 100 patients) and for those with an isolated infrarenal rAAA was 37% (33 of 89 patients). The presence of preoperative hemodynamic instability and the use of ABO were statistically significantly and independently associated with increased 30-day mortality on multivariate logistic regression analysis. CONCLUSIONS: All 100 patients who had undergone surgery for a rAAA had been treated using EVAR and endovascular adjuncts, with a relatively low mortality rate, thus continuing the "EVAR-only" approach. A low proportion of rAAA patients were considered surgically unsuitable. These findings support the applicability of EVAR for the treatment of all rAAAs at suitable centers.

Nationwide Study of Ruptured Abdominal Aortic Aneurysms During Twenty Years (1994-2013).

OBJECTIVE: To analyze the epidemiology of ruptured abdominal aortic aneurysms (RAAA) in Sweden over 20 years, and assess the effect of endovascular repair (EVAR) on surgical treatment rate and outcome. METHODS: All Swedish citizens >50 years with RAAA 1994 to 2013 were extracted from 3 national (Cause of Death, Patient, and Vascular Surgical) registries. Incidence, proportion repaired, surgical techniques, and 90-day mortality were assessed based on sex and age groups, with regression analysis. RESULTS: 18,726 individuals with RAAA were identified, 74.0% men. The incidence of RAAA decreased from 33.1/100,000: 1994 to 21.3/100,000: 2013 (relative change -35.6%, P < 0.001). The proportion of men with RAAA undergoing repair was 44.5%: 1994-1998, 49.7%: 2009-2013 (+11.7%, P < 0.001). In women, 22.3% were repaired in 1994-1998, versus 28.2%: 2009-2013 (+26.4%, P < 0.001). The proportion undergoing repair increased in octogenarians (men: +44.3%, P < 0.001; women +49.3%, P = 0.001). EVAR increased from 0% initially to 42.3% in men and 41.2% in women 2013. Overall, mortality rate among all individuals with RAAA decreased, men 75.8%: 1994-1998, 64.8%: 2009-2013 (-14.5%, P < 0.001); women 88.5%: 1994-1998, 82.2%: 2009-2013 (-7.1%, P < 0.001). Among those who underwent repair, mortality was 47.0% in men: 1994-1998, 31.8%: 2009-2013 (-32.3%, P < 0.001); women 51.8%: 1994-1998, 41.4%: 2009-2013 (-20.1%, P = 0.010). CONCLUSION: RAAA mortality among men decreased, mainly attributed to falling incidence of RAAA. The mortality was further reduced by more patients being offered repair, increasingly often with EVAR, and improved survival after repair. Incidence of rupture remained unchanged among women, who had higher RAAA mortality. Focused efforts to reduce RAAA mortality among women are warranted.

Surveillance to detect colonic ischemia with extraluminal pH measurement after open surgery for abdominal aortic aneurysm.

OBJECTIVE: Colonic ischemia (CI) is a life-threatening complication after aortic surgery. Postoperative surveillance of colonic perfusion might be warranted. The aim of the present study was to evaluate the safety and feasibility of postoperative extraluminal pH measurement (pHe) using colonic tonometry after open abdominal aortic aneurysm (AAA) repair. METHODS: Before closing the abdomen after open AAA repair, a tonometric catheter was placed transabdominally in contact with the sigmoid colon serosa, similar to a drainage catheter. Extraluminal partial pressure of carbon dioxide was measured postoperatively and combined with arterial blood gas analysis to calculate the pHe. The measurements were repeated every 4 hours with simultaneous intra-abdominal pressure measurements. The threshold for colonic malperfusion was set at pHe <7.2. RESULTS: A total of 27 patients were monitored, 12 had undergone surgery for ruptured AAAs and 15 for intact AAAs. Of the 27 patients, 4 developed clinically significant CI requiring surgery. All four cases were preceded by a prolonged (>5 hours) pHe <7.2 indicating malperfusion. A fifth patient, who, during monitoring, had had the lowest pHe of 7.21, developed mild CI with the onset after completion of monitoring, which was successfully managed conservatively. Seven patients who had had brief durations (<5 hours) of pHe <7.2 did not develop clinical signs of CI or any related adverse events. CONCLUSIONS: Measurements of pHe using colonic tonometry indicated malperfusion in all four patients who had developed clinically significant CI. A shorter duration of low pHe was well tolerated without any signs of CI. Measurement of pHe was safe and reliable for the surveillance of colonic perfusion after open aortic surgery, indicating a promising technique. However, larger studies are needed.

Risk Factors for Abdominal Compartment Syndrome After Endovascular Repair for Ruptured Abdominal Aortic Aneurysm: A Case Control Study.

OBJECTIVE: Ruptured abdominal aortic aneurysms (rAAA) are treated by endovascular aneurysm repair (rEVAR) increasingly often. Despite rEVAR being a minimally invasive method, abdominal compartment syndrome (ACS) remains a significant post-operative threat. The aim of this study was to investigate risk factors for ACS after rEVAR, including aortic morphological features. METHODS: The Swedish vascular registry (Swedvasc) was assessed for ACS after rEVAR in the period 2008 - 2015. All patients identified were compared with controls (i.e., patients who did not develop ACS after rEVAR), matched by centre and repair date. Case records were reviewed, and radiology images analysed in a core laboratory. Comparisons were performed with respect to physiological and radiological risk factors. RESULTS: The study population consisted of 40 patients with ACS and 68 controls. Pre-operatively, patients with ACS had a lower blood pressure (BP) than controls (median 70 mmHg vs. 97 mmHg; p < .001). Intra-operatively, they had aortic balloon occlusion more often (55.0% vs. 10.3%; p < .001) and received more transfusions than controls (median nine units of packed red blood cells [pRBC] vs. two units; p < .001). Ninety-seven per cent of those who developed ACS had a pre-operative BP < 70 mmHg, aortic balloon occlusion, or received more than five pRBC unit transfusions. Treatment outside the instructions for use did not differ between patients and controls (57.5% vs. 54.4%; p = .84), and neither did the pre-operative patency of the inferior mesenteric artery (57.1% vs. 63.9%; p = .52) nor the number of visible lumbar arteries on pre-operative imaging (2 vs. 4; p = .014). In multivariable logistic regression, the number of intra-operative transfusions were predictive of ACS (p < .001), while pre-operative hypotension (p = .32) and aortic balloon occlusion (p = .018) were not. CONCLUSION: ACS after rEVAR is mainly associated with physiological factors and is unlikely to develop without the presence of a pre-operative BP < 70 mmHg, the need for an aortic occlusion balloon, or more than five intra-operative pRBC unit transfusions. Treatment outside the IFU or any other morphological factor were not associated with a risk of ACS.

Editor's Choice - Abdominal Compartment Syndrome after Surgery for Abdominal Aortic Aneurysm: Subgroups, Risk Factors, and Outcome.

OBJECTIVES: Abdominal compartment syndrome (ACS) is a serious complication after abdominal aortic aneurysm (AAA) repair. The aim was to investigate outcome among subgroups and factors associated with outcome, with emphasis on the duration of intra-abdominal hypertension before treatment. METHODS: Since 2008, ACS and decompressive laparotomy (DL) after AAA repair are registered prospectively in the Swedish vascular registry (Swedvasc). Registry data and case records were reviewed. Subgroups were defined by main pathophysiological finding at DL, timing of DL after AAA repair, and treatment modality. RESULTS: During 2008-2015, 120 of 8765 patients undergoing surgery for infrarenal AAA developed post-operative ACS (1.4%). Eighty-three followed ruptured AAA (rAAA); 45 open surgical repairs (OSR) and 38 endovascular (EVAR), and thirty-seven after intact AAA (iAAA); 30 OSR and seven EVAR. The main pathophysiological findings at DL were bowel ischaemia in 27 (23.3%), post-operative bleeding in 34 (29.3%), and general oedema in 55 (47.4%). DL was performed <24 hours after AAA repair in 56 (48.7%), 24-48 hours in 30 (26.1%), and >48 hours in 29 patients (25.2%). The overall 90 day mortality was 50.0%, neither different depending on main pathophysiological finding, nor on the timing of DL. In multivariable regression analysis, age was a predictor of mortality (p = .017), while duration of intra-abdominal hypertension (IAH) prior to DL predicted the need for renal replacement therapy (RRT) (p = .033). DL was performed earlier after EVAR compared with OSR in rAAA (p < .001). CONCLUSIONS: Mortality in ACS was high, irrespective of the main pathophysiological finding and timing of DL. The duration of IAH prior to DL predicted the need for RRT. DL was performed earlier after EVAR than after OSR for rAAA, underlining the importance of monitoring IAP after EVAR for rAAA.

Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease.

BACKGROUND: Screening elderly men with ultrasound is an established method to reduce mortality from ruptured abdominal aortic aneurysm (AAA; Evidence Level 1a). Such programs are being implemented and generally consist of a single scan at 65 years of age. We report the results from screening 65-year-old men for AAA in middle Sweden. METHODS AND RESULTS: All 65-year-old men (n=26,256), identified through the National Population Registry, were invited to an ultrasound examination. An AAA was defined as a maximum infrarenal aortic diameter of ≥30 mm. In total, 22 187 (85%) accepted, and 373 AAAs were detected (1.7%; 95% confidence interval, 1.5 to 1.9). With 127 previously known AAAs (repaired/under surveillance) included, the total prevalence of the disease in the population was 2.2% (95% confidence interval, 2.0 to 2.4). Self-reported smoking (odds ratio, 3.4; P<0.001), coronary artery disease (odds ratio, 2.0; P<0.001), and hypertension (odds ratio, 1.6; P=0.001) were independently associated with AAA in a multivariate logistic regression model. Thirteen percent of the entire population reported to be current smokers, one third of the frequency reported in the 1980s. The observed low prevalence of AAA was explained mainly by this change in smoking habits. CONCLUSIONS: On the basis of the observed reduced exposure to risk factors, lower-than-expected prevalence of AAA among 65-year-old men, unchanged AAA repair rate, and significantly improved longevity of the elderly population, the current generally agreed-on AAA screening model can be questioned. Important issues to address are the threshold diameter for follow-up, the possible need for rescreening at a higher age, and selective screening among smokers.

Prevalence and natural history of and risk factors for subaneurysmal aorta among 65-year-old men.

Background: The aims of this study were to determine the prevalence of screening-detected subaneurysmal aorta (SAA), i.e. an aortic diameter of 2.5-2.9 cm, its associated risk factors, and natural history among 65-year-old men. Methods: A total of 14,620 men had their abdominal aortas screened with ultrasound and completed a health questionnaire containing information on smoking habits and medical history. They were categorized based on the aortic diameter: normal aorta (<2.5 cm; n = 14,129), SAA (2.5-2.9 cm; n = 258), and abdominal aortic aneurysm (AAA) (≥3.0 cm; n = 233). The SAA-group was rescanned after 5 years. Associated risk factors were analyzed. Results: The SAA-prevalence was 1.9% (95% confidence interval 1.7%-2.1%), with 57.0% (50.7%-63.3%) expanding to ≥3.0 cm within 5 years. Frequency of smoking, coronary artery disease, hypertension, hyperlipidemia, and claudication were significantly higher in those with SAA and AAA compared to those with normal aortic diameter. Current smoking was the strongest risk factor for SAA (odds ratio [OR] 2.8; P < 0.001) and even stronger for AAA (OR 3.6; P < 0.001). Men with SAA expanding to AAA within 5 years presented pronounced similarities to AAA at baseline. Conclusions: Men with SAA and AAA presented marked similarities in the risk factor profile. Smoking was the strongest risk factor with an incremental association with disease severity, and disease progression. This indicates that SAA and AAA may have the same pathophysiological origin and that SAA should be considered as an early stage of aneurysm formation. Further research on the cost-effectiveness and potential benefits of surveillance as well as smoking cessation and secondary cardiovascular prevention in this subgroup is warranted.