Induced Moderate Hypothermia in Aortic Rupture With Retroperitoneal Bleeding: A Randomized Porcine Study.

OBJECTIVE: Induced hypothermia improves outcome in aortic arch surgery, neonatal neurointensive care, and transplant surgery for example. In contrast, spontaneous hypothermia has been associated with worse outcomes in patients suffering from hemorrhagic shock, mostly explained by its adverse effects on the coagulation system. We investigated if induced hypothermia would impair short-term survival in experimental aortic rupture with retroperitoneal bleeding. METHODS: Anesthetized pigs were randomized into 2 groups: hypothermia by peritoneal lavage of ice-cold Ringer's acetate and external cooling (n = 10) and normothermia (n = 10). Aortic rupture with retroperitoneal bleeding was induced by endovascular means creating a 6 mm hole in the retroperitoneal portion of abdominal aorta. Survival (primary outcome), hemodynamics, and arterial blood gases including lactate were collected and analyzed up to 180 min after aortic rupture. RESULTS: The body temperature (mean ± standard deviation) in the hypothermic group was 31.5 ± 1.0 °C and 38.7 ± 0.4 °C in the normothermic group at the time for aortic rupture. Survival up to 180 min after the retroperitoneal bleeding was significantly higher in the hypothermic compared with the normothermic group (P = 0.023). CONCLUSIONS: Induced hypothermia did not impair survival in this experimental retroperitoneal aortic bleeding model in anesthetized pigs. This finding may indicate a minor role for the coagulation system in this type of bleeding.

A Single Center Study of ProGlide Used for Closure of Large-Bore Puncture Holes After EVAR for AAA.

PURPOSE: The objective of this study was to evaluate the primary and assisted secondary percutaneous and non-invasive technical success of the ProGlide device on all-comers in a consecutive case series of percutaneous endovascular aortic aneurysm repair (P-EVAR). METHOD: A single-center consecutive case series where 434 elective and acute P-EVAR procedures were registered prospectively between May 2011 and July 2017. The mean age was 74.5 years ± SD 11.4 years. 82.3% of the patients were male. All patients were pre-planned from CT angiography. Percutaneous access punctures, performed in local anesthesia in the common femoral artery, with a final introducer size between 12-22 Fr OD were included and stratified in 2 groups, 12-16 Fr and 17-22 Fr. RESULTS: By screening 868 access groins 22 groins were excluded. Of the remaining 846 groins, intended to be treated with ProGlide, 9 groins were excluded peri-procedurally and treated with the Fascia Suture Technique or surgical cutdown. The remaining 837 groins had access closure with ProGlide, with a mean value of 2.15 devices per groin with a slight significant difference between the 2 stratification groups. Primary ProGlide technical success was achieved in 68.1% of the groins. Secondary percutaneous or non-invasive technical success was achieved in 96.9%. Here there was no statistically significant difference between the 2 stratification groups. Thirty-one (3.7%) groin complications were registered during 30-day follow-up and 17 required additional treatment. Total mortality was 2.8%. None of these deaths were related to the access site. CONCLUSION: ProGlide by itself has a significant failure rate in the closure of large-bore access holes on an unselected cohort of patients eligible for P-EVAR. However, together with adjunct percutaneous or non-invasive methods a success rate of 97% can be achieved. The access complication rate was lower than 4% at 30-day follow-up.

Novel Experimental Technique to Create Size-Controlled Retroperitoneal Bleeding in the Infrarenal Aorta of Anesthetized Pigs.

OBJECTIVE: Rupture of abdominal aortic aneurysm (rAAA) with a contained retroperitoneal hematoma is potentially fatal. Physiological studies are difficult to perform in patients suffering from life-threatening conditions such as rAAA. A translational model of the condition is therefore needed. The aim was to develop and validate an endovascular animal model for retroperitoneal bleeding of the abdominal aorta with contained hematoma. METHODS: In anesthetized pigs, a puncture hole was made in the posterolateral portion of the infrarenal aorta by an Outback re-entry catheter device. The hole was gradually enlarged using angioplasty balloons to a specific diameter of either 4 mm (n = 6), 6 mm (n = 7), or 8 mm (n = 6). Onset of bleeding was verified by angiography and macroscopically examined on completion of the experiments. Survival up to 180 min was the primary outcome. Hemodynamic and metabolic markers in arterial blood were secondary outcomes. RESULTS: Aortic injury with a contained retroperitoneal hematoma was achieved in all animals. Survival rate at 180 min after onset of bleeding was higher in the 4 mm group compared to the 6 mm (P = 0.021) and 8 mm groups (P = 0.002), but not when comparing the 6 mm and 8 mm groups. Systemic hypotension, arterial acidosis, and lactatemia were provoked in the 6 mm and 8 mm groups but not in the 4 mm group. CONCLUSIONS: A porcine model for a controlled contained left posterolateral retroperitoneal bleeding was created using endovascular methods and validated. This model makes it possible to study the pathophysiology of a retroperitoneal hematoma.

Aortic balloon occlusion (REBOA) in pelvic ring injuries: preliminary results of the ABO Trauma Registry.

EndoVascular and Hybrid Trauma Management (EVTM) has been recently introduced in the treatment of severe pelvic ring injuries. This multimodal method of hemorrhage management counts on several strategies such as the REBOA (resuscitative endovascular balloon occlusion of the aorta). Few data exist on the use of REBOA in patients with a severely injured pelvic ring. The ABO (aortic balloon occlusion) Trauma Registry is designed to capture data for all trauma patients in hemorrhagic shock where management includes REBOA placement. Among all patients included in the ABO registry, 72 patients presented with severe pelvic injuries and were the population under exam. 66.7% were male. Mean and median ISS were respectively 43 and 41 (SD ± 13). Isolated pelvic injuries were observed in 12 patients (16.7%). Blunt trauma occurred in 68 patients (94.4%), penetrating in 2 (2.8%) and combined in 2 (2.8%). Type of injury: fall from height in 15 patients (23.1%), traffic accident in 49 patients (75.4%), and unspecified impact in 1 patient (1.5%). Femoral access was gained pre-hospital in 1 patient, in emergency room in 43, in operating room in 12 and in angio-suite in 16. REBOA was positioned in zone 1 in 59 patients (81,9%), in zone 2 in 1 (1,4%) and in zone 3 in 12 (16,7%). Aortic occlusion was partial/periodical in 35 patients (48,6%) and total occlusion in 37 patients (51,4%). REBOA associated morbidity rate: 11.1%. Overall mortality rate was 54.2% and early mortality rate (≤ 24 h) was 44.4%. In the univariate analysis, factors related to early mortality (≤ 24 h) are lower pH values (p = 0.03), higher base deficit (p = 0.021), longer INR (p = 0.012), minor increase in systolic blood pressure after the REBOA inflation (p = 0.03) and total aortic occlusion (p = 0.008). None of these values resulted significant in the multivariate analysis. In severe hemodynamically unstable pelvic trauma management, REBOA is a viable option when utilized in experienced centers as a bridge to other treatments; its use might be, however, accompanied with severe-to-lethal complications.

Outcome After Endovascular Repair of Ruptured Descending Thoracic Aortic Aneurysm: A National Multicentre Study.

OBJECTIVE: The purpose of this multicentre study was to analyse the outcome of thoracic endovascular aortic repair (TEVAR) in patients with ruptured descending thoracic aortic aneurysm (rDTAA). METHODS: This is a nationwide retrospective study including all patients who underwent TEVAR for rDTAA at six major vascular university centres in Sweden between January 2000 and December 2015. Outcome measures were analysed using Kaplan-Meier estimator and multivariable Cox regression. RESULTS: There were 140 patients (age [mean ± SD] 74.1 ± 8.8 years; 56% men; aneurysm size 64.8 ± 19 mm), with rDTAA. In 53 patients (37.9%), the left subclavian artery was covered, and in 25 patients (17.9%) arch vessel revascularisation was performed. In total, 61/136 patients (45%) had a major complication within 30 days post TEVAR. Stroke (n = 20; 14.7%) was the most common complication, followed by paraplegia (n = 13; 9.6%) and major bleeding (n = 13; 9.6%). TEVAR related complications during follow up included endoleaks 22.1% (30/136; 14 type 1a, six type 1b, 10 not defined). In total, re-interventions (n = 31) were required in 27/137 (19.7%) patients. The median follow up time was 17.0 months (range 0-132 months). The Kaplan-Meier estimated survival was 80.0% at one month, 71.7% at three months, 65.3% at one year, 45.9% at three years, and 31.9% at five years. Age (HR 1.03; 95% CI 1.00-1.07; p = .046), history of stroke (HR 2.35; 95% CI 1.19-4.63; p = .014), previous aortic surgery (HR 2.11; 95% CI 1.15-3.87; p = .016) as well as post-operative major bleeding (HR 4.40; 95% CI 2.20-8.81; p = .001), stroke (HR 2.63; 95% CI 1.37-5.03; p = .004), and renal failure (HR 8.25; 95% CI 2.69-25.35; p = .001) were all associated with mortality. CONCLUSIONS: This nationwide multicentre study of patients with rDTAA undergoing TEVAR showed acceptable short- but poor long-term survival. Adequate proximal and distal aortic sealing zones are important for technical success. High risk patients and post-operative complications need to be further addressed in an effort to improve outcome.

No-touch technique for radiocephalic arteriovenous fistula--surgical technique and preliminary results.

PURPOSE: The radiocephalic arteriovenous fistula (RC-AVF) has significant failure rates due to occlusions and failure to mature. The size and quality of the veins are considerable limiting factors for the procedure. The aim of this pilot study was to describe the No-Touch technique (NTT) to create RC-AVF and present the results up to 1 year of follow-up. METHODS: Thirty-one consecutive patients who were referred for surgery for a RC-AVF were included (17 men, mean age 63 years, range 35-84) and operated by NTT where the vein and artery were dissected with a tissue cushion around it. Twenty-two patients had small veins or arteries (≤2 mm), 12 patients had a small cephalic vein (≤2 mm), and the mean distal cephalic vein diameter was 2.4 mm (range 1.0-4.1 mm). RESULTS: Technical surgical success and immediate patency were obtained in all patients. Clinical success was achieved in 23 of the 27 (85%) patients who required hemodialysis. The proportion of primary patency at 30 days and 6 months was 84% and 64%, respectively. Secondary patency at 30 days and 6 months was 97% and 83%, respectively. At 1-year follow-up, primary patency was 54% and secondary patency was 80%. There was no major difference in patency due to preoperative vein diameter. CONCLUSIONS: The results of this study indicate that NTT can be used for primary radio-cephalic fistula surgery with very good results. This method offers the potential to create a RC-AVF in patients who are not usually considered appropriate for a distal arm fistula due to a small cephalic vein.

Endovascular treatment of mycotic aortic aneurysms: a European multicenter study.

BACKGROUND: Mycotic aortic aneurysm (MAA) is a rare and life-threatening disease. The aim of this European multicenter collaboration was to study the durability of endovascular aortic repair (EVAR) of MAA, by assessing late infection-related complications and long-term survival. METHODS AND RESULTS: All EVAR treated MAAs, between 1999 and 2013 at 16 European centers, were retrospectively reviewed. One hundred twenty-three patients with 130 MAAs were identified. Mean age was 69 years (range 39-86), 87 (71%) were men, 58 (47%) had immunodeficiency, and 47 (38%) presented with rupture. Anatomic locations were ascending/arch (n=4), descending (n=34), paravisceral (n=15), infrarenal aorta (n=63), and multiple (n=7). Treatments were thoracic EVAR (n=43), fenestrated/branched EVAR (n=9), and infrarenal EVAR (n=71). Antibiotic was administered for mean 30 weeks. Mean follow-up was 35 months (range 1 week to 149 months). Six patients (5%) were converted to open repair during follow-up. Survival was 91% (95% confidence interval, 86% to 96%), 75% (67% to 83%), 55% (44% to 66%), and 41% (28% to 54%) after 1, 12, 60, and 120 months, respectively. Infection-related death occurred in 23 patients (19%), 9 after discontinuation of antibiotic treatment. A Cox regression analysis demonstrated non-Salmonella-positive culture as predictors for late infection-related death. CONCLUSIONS: Endovascular treatment of MAA is feasible and for most patients a durable treatment option. Late infections do occur, are often lethal, and warrant long-term antibiotic treatment and follow-up. Patients with non-Salmonella-positive blood cultures were more likely to die from late infection.

Intraperitoneal metabolic consequences of supraceliac aortic balloon occlusion in an experimental animal study using microdialysis.

BACKGROUND: To investigate the effects of supraceliac aortic balloon occlusion (ABO) and superior mesenteric artery (SMA) occlusion on abdominal visceral metabolism in an animal model using intraperitoneal microdialysis (IPM) and laser Doppler flowmetry. METHODS: A total of 9 pigs were subjected to ABO and 7 animals were subjected to SMA occlusion for 1 hour followed by 3 hours of reperfusion. Seven animals served as controls. Hemodynamic data, arterial blood samples, urinary output, and intestinal mucosal blood flow (IBF) were followed hourly. Intraperitoneal (i.p) glucose, glycerol, lactate, and pyruvate concentrations and lactate-to-pyruvate (l/p) ratio were measured using IPM. RESULTS: Compared with the baseline, ABO reduced IBF by 76% and decreased urinary output. SMA occlusion reduced IBF by 75% without affecting urinary output. ABO increased the i.p l/p ratio from 18 at baseline, peaking at 46 in early reperfusion. SMA occlusion and reperfusion tended to increase the i.p l/p ratio, peaking at 36 in early reperfusion. ABO increased the i.p glycerol concentration from 87 µM at baseline to 579 µM after 3 hours of reperfusion. SMA occlusion and reperfusion increased the i.p glycerol concentration but to a lesser degree. CONCLUSIONS: Supraceliac ABO caused severe hemodynamic, renal, and systemic metabolic disturbances compared with SMA occlusion, most likely because of the more extensive ischemia-reperfusion injury. The intra-abdominal metabolism, measured by microdialysis, was affected by both ABO and SMA occlusion but the most severe disturbances were caused by ABO. The i.p l/p ratios and the glycerol concentrations increased during ischemia and reperfusion and may serve as markers of these events and indicate anaerobic metabolism and cell damages respectively.

Complication rate of the fascia closure technique in endovascular aneurysm repair.

PURPOSE: To assess the rate of complications associated with the fascia closure technique for femoral access sites in which 18-F or 20-F sheaths were introduced during endovascular aneurysm repair (EVAR). METHODS: A retrospective analysis was done of 50 consecutive patients (41 men; median age 75 years, range 62-85) who received Excluder stent-grafts in planned percutaneous EVAR procedures from May 2006 until December 2009. The fascia closure technique was routinely used for all femoral access sites in which large bore (18-F and 20-F) introducers were employed. One patient with extremely calcified and narrowed vessels was converted to primary cutdown bilaterally after percutaneous access failed. In the 49 remaining patients, 81 femoral access sites were closed with the fascia closure technique; 17 sites with smaller 12-F introducers were closed using other techniques. Computed tomographic angiography (CTA) was performed within 30 days, at 6 months, and at 1, 2, and 3 years. RESULTS: Of the 81 femoral access sites closed with the fascia closure technique, only 1 patient had persistent bleeding that required an immediate cutdown and suture repair of the deep femoral artery (99.0% technical success rate). In the immediate postoperative period, 5 patients required additional interventions for bleeding (n = 2), occlusion (n = 2), or a pseudoaneurysm [92.6% 30-day technical success]. At 30 days, 11 (13.9%) of 79 access sites had pseudoaneurysms, all of which resolved within a year; none required a secondary intervention. Later surveillance scans did not detect pseudoaneurysms. CONCLUSION: The fascia closure technique during EVAR is safe and has few complications. The low frequencies of pseudoaneurysms and other access site complications make the femoral closure technique a durable alternative.

Collected world and single center experience with endovascular treatment of ruptured abdominal aortic aneurysms.

BACKGROUND: Case and single center reports have documented the feasibility and suggested the effectiveness of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs), but the role and value of such treatment remain controversial. OBJECTIVE: To clarify these we examined a collected experience with use of EVAR for RAAA treatment from 49 centers. METHODS: Data were obtained by questionnaires from these centers, updated from 13 centers committed to EVAR treatment whenever possible and included treatment details from a single center and information on 1037 patients treated by EVAR and 763 patients treated by open repair (OR). RESULTS: Overall 30-day mortality after EVAR in 1037 patients was 21.2%. Centers performing EVAR for RAAAs whenever possible did so in 28% to 79% (mean 49.1%) of their patients, had a 30-day mortality of 19.7% (range: 0%-32%) for 680 EVAR patients and 36.3% (range: 8%-53%) for 763 OR patients (P < 0.0001). Supraceliac aortic balloon control was obtained in 19.1% +/- 12.0% (+/-SD) of 680 EVAR patients. Abdominal compartment syndrome was treated by some form of decompression in 12.2% +/- 8.3% (+/-SD) of these EVAR patients. CONCLUSION: These results indicate that EVAR has a lower procedural mortality at 30 days than OR in at least some patients and that EVAR is better than OR for treating RAAA patients provided they have favorable anatomy; adequate skills, facilities, and protocols are available; and optimal strategies, techniques, and adjuncts are employed.

Limb ischemia after EVAR: an effect of the obstructing introducer?

PURPOSE: To evaluate the splanchnic and limb metabolic effects of open repair (OR) of abdominal aortic aneurysms (AAA) versus endovascular aneurysm repair (EVAR) in a pilot study utilizing microdialysis. METHODS: Nine AAA patients (8 men; mean age 74 years, range 61-85) were treated with EVAR and 9 had an OR (5 men; mean age 70 years, range 55-85). In the EVAR cases, which were performed percutaneously, the external iliac artery was obstructed by the introducer to a mean functional stenosis of 70% (52%-100%). Catheters for microdialysis were placed subcutaneously above the ankle of the right leg and freely in the abdominal cavity to measure the levels of lactate and pyruvate. The lactate/pyruvate ratio was calculated as a measure of ischemia. Measurements started at the end of surgery and continued for 2 days. Mean values were compared using the Mann-Whitney U test. RESULTS: The mean value of intraperitoneal lactate during the first day after EVAR was 1.5+/-0.7 mM versus 2.6+/-0.8 mM after OR (p = 0.019). The lactate/pyruvate ratio was 10.2+/-2.2 after EVAR and 12.3+/-2.6 after OR (p = 0.113). Leg lactate mean values were 4.2+/-2.0 mM after EVAR versus 1.8+/-0.6 mM after OR (p<0.001). The lactate/pyruvate ratio was 20.1+/-8.3 for EVAR and 13.7+/-3.3 for OR (p = 0.040). These differences between EVAR and OR continued for the second day. CONCLUSION: Intraperitoneally, metabolism was slightly increased after OR; however, it was not suggestive of splanchnic ischemia. Leg findings reflected a more extensive ischemia after EVAR over 48 hours, which was a somewhat unexpected finding that may be related to the introducer's impact on blood flow to the limb during the intervention. Although no clinical consequences were recorded, the finding suggests some benefit of minimizing as much as possible the time of reduced perfusion to the limb.

Fascia suturing of large access sites after endovascular treatment of aortic aneurysms and dissections.

PURPOSE: To evaluate a technique for closure of a femoral artery access in which the cribriform fascia covering the common femoral artery is sutured. METHODS: A consecutive series of 127 patients (103 men; median age 74 years, range 45- 89) underwent endovascular aortic aneurysm repair between August 2001 and September 2004. Twelve patients underwent a secondary intervention for a total of 139 procedures in the group. Sixty-one (43.9%) of the 139 operations were acute. Among the 257 femoral arteries used for access, a fascia suturing technique was performed in 131 (51.0%). Data were collected for analysis of access site complications, bleeding, thrombosis, pseudoaneurysm, and stenosis. A subgroup of 72 patients had ankle-brachial indexes (ABI) recorded; another subgroup of 50 patients were also investigated by duplex ultrasonography. RESULTS: Complications occurred in 18 (13.7%) of the 131 sutured cases. The majority (n = 16) arose within 24 hours: 8 cases of perioperative bleeding or thrombosis required open surgery and 8 cases were reoperated within 24 hours for bleeding (n = 4), thrombosis (n = 3), and 1 intimal dissection. The acute failure rate was 12.2%. Two patients had late complications: 1 case of neuralgia and 1 pseudoaneurysm that required acute surgery 28 months postoperatively. The ABI did not change significantly from pre- to postoperatively in the 72 patients examined. Five patients with stenoses did not have a reduction in ABI. In the 66 sites examined with ultrasound in 50 patients, 3 minor pseudoaneurysms were detected. CONCLUSION: The fascia suturing technique for closure of a femoral artery access during endovascular repair of aortic diseases is feasible, even in acute situations. Failures can be managed easily. Late complications requiring additional procedures are rare.

Endovascular treatment of ruptured abdominal aortic aneurysms: a shift of the paradigm?

PURPOSE: To compare endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (rAAA) to the results with open surgery. METHODS: Between May 2001 and January 2004, 50 patients were diagnosed with rAAA. Fifteen (30%) patients (14 men; median age 73 years, range 58-85) underwent EVAR, while 26 (52%) patients (23 men; median age 75 years, range 60-84) had open surgery. Nine (18%) patients (5 men; median age 86 years, range 77-91) were not operated upon. Circulatory shock was defined as systolic blood pressure<80 mmHg. Mortality was defined as death within 30 days after operation; in cases where hospital stay exceeded 30 days, in-hospital mortality was registered. Five risk factors (age>76 years, loss of consciousness, hemoglobin<90 g/L, creatinine>190 micromol/L, and electrocardiographic ischemia) were analyzed. RESULTS: In the EVAR group, 93% (14/15) of the aneurysms were excluded from the bloodstream; there were 2 (13%) conversions: 1 intraoperatively for stent-graft migration and another owing to dissection prior to hospital discharge. Mortality after open surgery was 46% (12/26) versus 13% (2/15) in the EVAR group (p>0.05). Univariate analysis without considering variables other than mortality resulted in OR 5.4 (95% CI 0.9 to 58; p=0.07). Considering risk factors and shock, multivariate analysis resulted in OR 6.5 (95% CI 0.8 to 96; p=0.08). In the EVAR group, 60% (9/15) had complications; in the group with open surgery, the complication rate was 85% (22/26; p=0.13). CONCLUSIONS: It is possible to treat rAAA with EVAR. Hypotensive patients can, at least initially, be operated under local anesthesia to stabilize blood pressure utilizing a percutaneously inserted occlusion balloon. There was a trend in our study for reduced mortality and morbidity with EVAR, but further studies are required to conclude whether EVAR significantly increases survival and reduces complications.

[Endovascular treatment possible in ruptured abdominal aortic aneurysm]. / Endovaskulär metod möjlig vid rupturerade bukaortaaneurysm.

Since 1996 we have performed endovascular treatment (EVAR, endovascular aortic aneurysm repair) for elective abdominal aortic aneurysms (AAA) and since 2001 also for ruptured AAA (rAAA). All patients who were treated for rAAA during the period May 2001-January 2004 were retrospectively studied. Mortality was defined as 30-day mortality or hospital mortality when the hospital stay exceeded 30 days. 50 patients had rAAA, nine of them were not operated upon. 26 patients had open surgery, 15 had EVAR. Five risk predictors according to Hardman (age >76 years, loss of consciousness, Hb 90 g/l, creatinine level >0.19 mmol/l and electrocardiographic ischemia) as well as shock (BP <80 mm Hg) were registered. The mortality among the patients after open surgery was 46% and after EVAR 13%. By considering risk factors and shock a multivariate analysis resulted in OR = 6.5 (95% CI: 0.8-96; p = 0.079), supporting that any selection of the material had not influenced the result. We conclude that it is possible to treat rAAA with EVAR. Hypotensive patients can, at least initially, be operated under local anaesthesia with stabilization of blood pressure utilizing a percutaneously inserted occlusion balloon. Further studies are required to conclude whether EVAR significantly increases survival and reduces complications.