Infrarenal Clamping Research Articles

Retroperitoneal vs transperitoneal approach for nonruptured open conversion after endovascular aneurysm repair

ObjectiveSeveral studies comparing the transperitoneal (TP) and retroperitoneal (RP) approach for abdominal aortic aneurysm (AAA) repair suggest that the RP approach may result in lower rates of perioperative mortality and morbidity. However, data comparing these approaches for open conversion are lacking. This study aims to evaluate the association between the type of approach and outcomes following open conversion after endovascular aneurysm repair (EVAR). MethodsWe included all patients who underwent open conversion after EVAR between 2010 and 2022 in the Vascular Quality Initiative. Patients presenting with rupture were excluded. The primary outcome was perioperative mortality. The secondary outcomes included perioperative complications and 5-year mortality. Inverse probability weighting was used to adjust for factors with statistical or clinical significance. Logistic regression was used to assess perioperative mortality and complications in the weighted cohort. The 5-year mortality was evaluated using Kaplan-Meier and Cox regression. ResultsWe identified 660 patients (39% RP) who underwent open conversion after EVAR. Compared with TP, RP patients were older (75 years [interquartile range, 70-79 years] vs 73.5 years [interquartile range, 68-79 years]; P < .001), and more frequently had prior myocardial infarction (33% vs 22%; P = .002). Compared with the TP approach, the RP approach was used less frequently in cases of associated iliac aneurysm (19% vs 27%; P = .026), but more frequently with associated renal bypass (7.8% vs 1.7%; P < .001) and by high-volume physicians (highest quintile, >7 AAA annually: 41% vs 17%; P < .001) and in high-volume centers (highest quintile, >35 AAA annually: 36% vs 20%; P < .001). RP patients, compared with TP patients, were less likely to have external iliac or femoral distal anastomosis (8.2% vs 21%; P < .001), and an infrarenal clamp (25% vs 36%; P < .001). Unadjusted perioperative mortality was not significantly different between approaches (RP vs TP: 3.8% vs 7.5%; P = .077). After risk adjustment, RP patients had similar odds of perioperative mortality (adjusted odds ratio [aOR], 0.49; 95% confidence interval [CI], 0.22-1.10; P = .082), and lower odds of intestinal ischemia (aOR, 0.26; 95% CI, 0.08-0.86; P = .028) and in-hospital reintervention (aOR, 0.43; 95% CI, 0.22-0.85; P = .015). No significant differences were found in the other perioperative complications or 5-year mortality (aHR, 0.79; 95% CI, 0.47-1.32; P = .37). ConclusionsOur findings suggest that the RP approach may be associated with a lower adjusted odds of perioperative complications compared with the TP approach. The RP approach should be considered for open conversion after EVAR when feasible.

Lessons Learned with Enhanced Recovery for Open Abdominal Aortic Aneurysm Surgery: A Long Term Regional Network Experience

This enhanced recovery programme (ERP) aimed to achieve early recovery for patients undergoing major surgery. Results of a standardised ERP protocol for open infrarenal abdominal aortic aneurysm (AAA) repair within a hub and spoke regional network are presented. In this monocentric prospective study (January 2004 - December 2021), consecutive AAAs (≥ 55 mm) were included in the ERP (patient discharge on post-operative day [POD] 4). The four phases of the ERP were pre-admission, pre-operative, intra-operative, and post-operative. Exclusion criteria were BMI > 35 kg/m2, functional capacity < 4 MET, previous aortic or abdominal surgery, and life expectancy < 5 years. Transperitoneal surgery was undertaken with routine AAA resection, graft interposition, and closure. Consecutive patients (n = 778) were enrolled into the study (mean age 72.3 ± 3.2 years; n = 712 men); 160 (20.5%) were treated in spoke hospitals. Median follow up was 78 (IQR 28, 128) months; median length of stay, procedure time, and blood loss were 4 days (IQR 3, 5), 190 min (IQR 170, 225), and 564 mL (IQR 300, 600). Infrarenal clamping and tube graft configuration were used in 96.5% (n = 751) and 72.5% (n = 564) of patients; 30 day mortality and complication rates were 0.4% (n = 3) and 9.2% (n = 72). Discharge after POD 4 occurred in 15.0%, and most significant predictors for discharge after POD 4 were haemotransfusion, re-intervention, and ileus over 3 days. Overall survival was: 98.2% at 1 year, 85.0% at 5 years, and 59.9% at 10 years. Freedom from re-intervention was 97.9% at 1 year, 94.1% at 5 years, and 86.8% at 10 years. Short and long term outcomes were comparable between hub and spoke hospitals. The ERP protocol was associated with low short and long term mortality and complication rates. Future studies should apply the ERP protocol to other vascular centres.

Intraoperative predictors of in-hospital mortality after open repair of ruptured abdominal aortic aneurysms.

Several models and scores have been released to predict early mortality in patients undergoing surgery for a ruptured abdominal aortic aneurysm (rAAA). These scores included above all preoperative factors and they could be useful to deny surgical repair. The aim of the study was to evaluate intraoperative predictors of in-hospital mortality in patients undergoing open surgical repair (OSR) for a rAAA. Between January 2007 and December 2020, 265 patients were admitted at our tertiary referral hospital for a rAAA. Two-hundred-twenty-two patients underwent OSR. Intra-operative factors were analyzed by means of univariate analysis (step 1). Associations of procedure variables with in-hospital mortality rates were sought based on a multivariate Cox regression analysis (step 2). Overall, in-hospital mortality rate was 28.8% (64 cases). Multivariate Cox regression analysis reported that operation time >240 minutes (P=0.032, OR 2.155, CI 95% 1.068-4.349), and hemoperitoneum (P<0.001, OR 3.582, CI 95% 1.749-7.335) were negative predictive factors for in-hospital mortality. Patency of at least one hypogastric artery (P=0.010; OR 0.128, CI 95% 0.271-0.609), and infrarenal clamping (P=0.001; OR 0.157, CI 95% 0.052-0.483) had a protective role in reducing in-hospital mortality rate. Operation time >240 minutes, and hemoperitoneum affected in-hospital mortality in patients undergoing OSR for rAAA. Patency of at least one hypogastric artery, and infrarenal clamping had a protective role. Further studies are needed to validate these outcomes. A validated predictive model could be useful to help the physicians in communication with patients' relatives.

Surgical Treatment of Sac Enlargement Due to Type II Endoleaks Following Endovascular Aneurysm Repair

An aneurysm sac enlargement caused by type II endoleak (T2EL) following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms may cause serious complications such as rupture. Consequently, methods that preoperatively prevent or postoperatively treat T2EL have been employed. When significant aneurysm enlargement occurs due to persistent T2EL, embolization is first performed through several access points. However, although these endovascular reinterventions have a high technical success rate and are safe, their effectiveness remains questionable. When such endovascular procedures fail to stabilize sac enlargement, open surgical conversion (OSC) becomes the last-resort treatment option. We review several strategies of OSC for the repair of T2EL following EVAR. Among the three main OSC procedures, namely, complete endograft removal, partial endograft removal, and complete endograft preservation, partial endograft removal under infrarenal clamping was considered the most appropriate owing to its less invasiveness and durability.

Cross-clamp location and perioperative outcomes after open infrarenal abdominal aortic aneurysm repair: A Vascular Quality Initiative® review.

By analyzing national Vascular Quality Initiative (VQI) data for patients undergoing open infrarenal abdominal aortic aneurysms (AAA) repair, we sought to better characterize the effects of different suprarenal clamping positions on postoperative outcomes. We performed a retrospective analysis of a prospectively collected national VQI database for all open infrarenal AAA repairs performed between 2003 and 2017. Patients were initially divided into proximal (above 1 renal, above 2 renals, and supraceliac) and infrarenal clamp groups. Patients were then subdivided into those who underwent surgery between 2003-2010 and those who had surgery between 2011-2017. Univariate followed by multivariate analyses were done to compare the baseline characteristics, preoperative, intraoperative, and postoperative outcomes between the two groups. During the study period, 9068 open AAA repairs were recorded in the VQI; of these, 5043 met the inclusion criteria. Aortic clamp level was infrarenal in 59% (N = 2975), above 1 renal in 15% (N = 735), above both renals in 21% (N = 1053), and supraceliac in 5% (N = 280). The average age was 69 years, and males comprised 73% (N = 3701) of the cohort. The overall 30-day mortality for the entire study group was 2.7%. On univariate analysis, patients who underwent proximal clamping had significantly higher 30-day mortality than those undergoing infrarenal clamping (3.7 vs 2.0%, p < 0.001). After adjusting for preoperative and intraoperative variables, this difference became nonsignificant. On multivariate analysis, clamping above both renals or the celiac artery was associated with an increased occurrence of postoperative myocardial infarction (odds ratio = 1.44, p = 0.037 and odds ratio = 1.78, p = 0.023, respectively). All proximal clamp positions were associated with a significant increase in the incidence of AKI and renal failure requiring dialysis. There was no significant difference when looking at overall survival times comparing the suprarenal and infrarenal clamp position groups (p = 0.1). Patients who underwent surgery in the latter half of the study period had longer intraoperative renal ischemia time, increased in estimated blood loss, and longer total procedure time. Suprarenal clamping, at any level, was associated with an increased risk of AKI and renal replacement therapy. Clamping above both renal and celiac arteries was associated with increased cardiac morbidity. Perioperative and long-term mortality was unaffected by clamp level. Patients operating in the latter half of the study had increased estimated blood loss, renal ischemia time, and operative time, which may reflect decreased training in open AAA repair. During open AAA repair, the proximal clamp site should be chosen based on anatomic considerations and not a perceived perioperative mortality benefit. Proximal aortic clamping should always be performed at the safest, distal-most level to reduce cardiac morbidity and the risk of postoperative dialysis.

Aortic Neck IFU Violations During EVAR for Ruptured Infrarenal Aortic Aneurysms are Associated with Increased In-Hospital Mortality

Vascular surgeons treating patients with ruptured abdominal aortic aneurysm must make rapid treatment decisions and sometimes lack immediate access to endovascular devices meeting the anatomic specifications of the patient at hand. We hypothesized that endovascular treatment of ruptured abdominal aortic aneurysm (rEVAR) outside manufacturer instructions-for-use (IFU) guidelines would have similar in-hospital mortality compared to patients treated on-IFU or with an infrarenal clamp during open repair (ruptured open aortic aneurysm repair [rOAR]). Vascular Quality Initiative datasets for endovascular and open aortic repair were queried for patients presenting with ruptured infrarenal AAA between 2013-2018. Graft-specific IFU criteria were correlated with case-specific proximal neck dimension data to classify rEVAR cases as on- or off-IFU. Univariate comparisons between the on- and off-IFU groups were performed for demographic, operative and in-hospital outcome variables. To investigate mortality differences between rEVAR and rOAR approaches, coarsened exact matching was used to match patients receiving off-IFU rEVAR with those receiving complex rEVAR (requiring at least one visceral stent or scallop) or rOAR with infrarenal, suprarenal or supraceliac clamps. A multivariable logistic regression was used to identify factors independently associated with in-hospital mortality. 621 patients were treated with rEVAR, with 65% classified as on-IFU and 35% off-IFU. The off-IFU group was more frequently female (25% vs. 18%, P = 0.05) and had larger aneurysms (76 vs. 72 mm, P= 0.01) but otherwise was not statistically different from the on-IFU cohort. In-hospital mortality was significantly higher in patients treated off-IFU vs. on-IFU (22% vs. 14%, P= 0.02). Off-IFU rEVAR was associated with longer operative times (135 min vs. 120 min, P= 0.004) and increased intraoperative blood product utilization (2 units vs. 1 unit, P= 0.002). When off-IFU patients were matched to complex rEVAR and rOAR patients, no baseline differences were found between the groups. Overall in-hospital complications associated with off-IFU were reduced compared to more complex strategies (43% vs. 60-81%, P< 0.001) and in-hospital mortality was significantly lower for off-IFU rEVAR patients compared to the supraceliac clamp group (18% vs. 38%, P= 0.006). However, there was no significantly increased mortality associated with complex rEVAR, infrarenal rOAR or suprarenal rOAR compared to off-IFU rEVAR (all P> 0.05). This finding persisted in a multivariate logistic regression. Off-IFU rEVAR yields inferior in-hospital survival compared to on-IFU rEVAR but remains associated with reduced in-hospital complications when compared with more complex repair strategies. When compared with matched patients undergoing rOAR with an infrarenal or suprarenal clamp, survival was no different from off-IFU rEVAR. Taken together with the growing available evidence suggesting reduced long-term durability of off-IFU EVAR, these data suggest that a patient's comorbidity burden should be key in making the decision to pursue off-IFU rEVAR over a more complex repair when proximal neck violations are anticipated preoperatively.

Balloon Endoclamping for Postdissection Infrarenal Aorto-Iliac Aneurysm Repair

Isolated post dissection infrarenal and iliac aneurysm is a rare condition that often requires surgical treatment. Surgical repair should involve the replacement of the aneurysmal segments and a wide fenestration in the residual proximal untreated abdominal aorta. However, in these patients proximal aortic clamping may be challenging. Indeed, infrarenal clamping may hamper an appropriate fenestration in the proximal dissecting lamella, and suprarenal or supraceliac clamping can be dangerous and highly demanding, especially in acute and subacute patients. Here we report our initial experience with a balloon endoclamping technique. Our technique includes 1) direct aortic true lumen catheterization, 2) balloon endoclamping of the proximal thoracic aorta, 3) wide fenestration of the infrarenal aorta followed by external clamp positioning, 4) infrarenal aorta and iliac artery reconstruction. Between October 2018 and November 2019, 4 patients (male n = 4, median age 57 years) underwent postdissection iliac aneurysm repair in our institution. All patients had previously undergone emergent thoracic aorta repair. Postoperative courses were uneventful in all cases. At a median FU of 13 months, all patients remain well, with stable diameters in visceral aorta. In our initial experience, proximal aortic endoclamping appeared to be a safe technique associated with promising results. This approach may facilitate proximal aortic clamping and allow for a wide aortic fenestration. Further larger clinical trials are needed to validate our preliminary observations.

Successful conversion strategy in patient submitted to EVAR demanding open surgery: comparative analysis 1997–2011 vs 2012–2020

Late open conversion in our center has been reviewed in the past 8 years, comparing 1997-2011 (first period group A) with 2012-2020 (second period group B). A retrospective analysis of patients treated at our centre by standard EVAR for infrarenal aortic aneurysm requiring late open conversion between January 1997 and February 2020 was performed. All stent grafts were implanted according to their current IFU all patients. The data concerning intra and postoperative complications were collected. Post-operative evaluated data include: ICU (Intensive Care Unit) stay, major peri-operative (<30 days) complications, in hospital mortality, length of hospital stay, 30-days mortality, and mid-term outcomes. Between January 2012 and February 2020 (group B), in our institution 8 patients previously treated by stent graft with endoleak underwent open surgery. The incidence of conversions and the 30-day mortality rate were compared with that of previous years, from January 1997 to December 2011 (group A). 481 patients submitted to EVAR in a second part of the analysis have been considered, 8 patients underwent late open conversion (1.7%) (Group B) due to endoleak. Among January 1997 and December 2011 overall 268 EVAR were performed; during this first study period, surgical conversion had been performed in 14 patients (5.2%) (Group A). The average time from EVAR to open conversion was four years (range 12-88 months) in Group B, and it was 30 months (range 1-82 months) in Group A. In most cases, in both group A and group B the proximal aortic cross-clamping were infrarenal. After the emergent procedure in Group B (12.5%), we have observed a death, whereas three patients died in Group A in urgent situations (21.4%). The more frequent indication for open surgery is the Endoleak type 1 and migration in the two considered periods. Adherence with current IFU and the technical progress in endoprosthesis design maintain lower rate incidence. In most cases, open surgery for prostheses that require explantation can be performed with infrarenal clamping. Partial removal of the endoprosthesis in selected cases makes open conversion easier and appears durable. The results are unfair by numerous comorbidities; in both periods, urgent graft removal seems to elevate both mortality and morbidity, compared to elective surgery.

Thirty-day outcomes of open abdominal aortic aneurysm repair by proximal clamp level in patients with normal and impaired renal function

ObjectiveOpen surgical repair (OSR) of abdominal aortic aneurysms (AAAs) has often been reserved in contemporary practice for complex aneurysms requiring a suprarenal or supraceliac proximal clamp level. The present study investigated the associated 30-day outcomes of different proximal clamp levels in OSR of complex infrarenal/juxtarenal AAA in patients with normal renal function and those with chronic renal insufficiency (CRI). MethodsAll patients undergoing elective OSR of infrarenal and juxtarenal AAA were identified in the American College of Surgeons National Surgical Quality Improvement Program–targeted AAA database from 2012 to 2018. The patients were stratified into two cohorts (normal renal function [estimated glomerular filtration rate, ≥60 mL/min] and CRI [estimated glomerular filtration rate, <60 mL/min and no dialysis]) before further substratification into groups by the proximal clamp level (infrarenal, inter-renal, suprarenal, and supraceliac). The 30-day outcomes, including mortality, renal and pulmonary complications, and major adverse cardiovascular event rates, were compared within each renal function cohort between proximal clamp level groups using the infrarenal clamp group as the reference. Supraceliac clamping was also compared with suprarenal clamping. ResultsA total of 1284 patients with normal renal function and 524 with CRI were included in the present study. The proximal clamp levels for the 1808 patients were infrarenal for 1080 (59.7%), inter-renal for 337 (18.6%), suprarenal for 279 (15.4%), and supraceliac for 112 (6.2%). In the normal renal function cohort, no difference was found in 30-day mortality with any clamp level. Increased 30-day acute renal failure was only observed in the supraceliac vs infrarenal clamp level comparison (5.9% vs 1.5%; adjusted odds ratio [aOR], 3.97; 95% confidence interval [CI], 1.04-5.18; P = .044). In the CRI cohort, supraceliac clamping was associated with an increased rate of renal composite complications (22.7% vs 5.6%; aOR, 8.81; 95% CI, 3.17-24.46; P < .001) and ischemic colitis (13.6% vs 3.0%; aOR, 4.78; 95% CI, 1.38-16.62; P = .014) compared with infrarenal clamping and greater 30-day mortality (13.6% vs 2.4%; aOR, 6.00; 95% CI, 1.14-31.55; P = .034) and renal composite complications (22.7% vs 10.8%; aOR, 2.87; 95% CI, 1.02-8.13; P = .047) compared with suprarenal clamping. Suprarenal clamping was associated with greater renal dysfunction (10.8% vs 5.6%; aOR, 2.77; 95% CI, 1.08-7.13; P = .035) compared with infrarenal clamping, with no differences in mortality. No differences were found in 30-day mortality or morbidity for inter-renal clamping compared with infrarenal clamping in either cohort. No differences were found in major adverse cardiovascular events with higher clamp levels in either cohort. ConclusionsIn elective OSR of infrarenal and juxtarenal AAAs for patients with CRI, this study found a heightened mortality risk with supraceliac clamping and increased renal morbidity with suprarenal clamping, though these effects were not present for patients with normal renal function. Every effort should be made to keep the proximal clamp level as low as possible, especially in patients with CRI.

Cardiorespiratory fitness fails to predict short-term postoperative mortality in patients undergoing elective open surgery for abdominal aortic aneurysm.

Preoperative cardiopulmonary exercise testing aids surgical risk stratification and is an established predictor of mid- to long-term survival in patients undergoing elective open abdominal aortic aneurysm repair. Whether cardiopulmonary exercise testing also predicts 30-day mortality in this population remains to be established. Data for 109 patients (mean age 72 years) who underwent cardiopulmonary exercise testing to assess risk for surgical abdominal aortic aneurysm repair was analysed. Patients were classified according to cardiopulmonary fitness as fit (peak oxygen uptake ≥ 15ml O2.kg-1.min-1) or unfit (peak oxygen uptake less than 15ml O2.kg-1.min-1) and further stratified according to clamp position (infrarenal or suprarenal). Between-group postoperative outcomes were compared for in-hospital 30-day mortality, postoperative morbidity scale scores (day 5) and hospital length of stay. Seventy-nine patients underwent open surgery and 30 patients were treated conservatively. No deaths were recorded at 30 days post-surgery. Unfit patients with infrarenal clamping exhibited higher postoperative morbidity scale scores (64% vs 26%) and longer length of stay (four days) than fit patients (p < 0.05). Conversely, with suprarenal clamping, postoperative morbidity scale scores were similar and length of stay longer (three days) in fit compared with unfit patients (p < 0.05). Preoperative fitness level defined by peak oxygen uptake failed to identify patients at risk of 30-day mortality when undergoing elective abdominal aortic aneurysm repair. Postoperative morbidity and length of stay in patients with suprarenal clamping was high independent of cardiopulmonary fitness. These findings suggest that cardiopulmonary exercise testing may be a useful predictor of complications following infrarenal rather than suprarenal clamping but may not be a good predictor of 30-day mortality.

Acute Kidney Injury Following Elective Open Aortic Repair with Suprarenal Clamping.

Objective: To investigate predictors of acute kidney injury (AKI) following open aortic repair (OAR) requiring suprarenal clamping.Methods: The study included 833 nonhemodialysis patients who had undergone elective OAR (with suprarenal clamping, n=73; with infrarenal clamping, n=760). We evaluated AKI as defined by the criteria of the Kidney Disease Improving Global Outcomes (KDIGO) and compared in-hospital outcomes between the two groups. We also investigated the effects of AKI on outcomes, factors related to post-suprarenal clamping AKI, and efficacy of hypothermic renal perfusion (HRP) in the suprarenal clamping group.Results: For the suprarenal vs. infrarenal clamping group, in-hospital mortality was 0% (0/73) vs. 0.5% (4/760). The incidence of AKI was greater in the suprarenal clamping group (37% vs. 15%, P<0.001), and the hospital stay for patients with AKI was longer than for those patients without AKI (median, 21 days vs. 16 days; P=0.005). Renal ischemia time and bleeding volume >1,000 mL were associated with post-suprarenal clamping AKI. Renal ischemia time was longer with HRP (n=15) than without HRP (n=58) (median, 51 min vs. 33 min; P=0.011), and HRP did not decrease the incidence of AKI (40% vs. 36%; P=0.78).Conclusion: Prolonged renal ischemia and substantial intraoperative bleeding are associated with postoperative AKI following suprarenal clamping.

The evolution of open abdominal aortic aneurysm repair at a tertiary care center

BackgroundThe characteristics of and indications for open abdominal aortic aneurysm (AAA) repair have evolved over time. We evaluated these trends through the experience at a tertiary care academic center. MethodsA retrospective review was conducted for patients undergoing open AAA repair (inclusive of type IV thoracoabdominal aortic aneurysms) from 2005 to 2018 at an academic institution. Trends over time were evaluated using the Spearman test; Cox regression was used to determine predictors of mortality and to generate adjusted survival curves. ResultsThere were 628 patients (71.5% male; 88.2% white) with a mean age of 70.5 ± 9.4 years who underwent open AAA repair with a mean aneurysm diameter of 6.2 ± 1.5 cm. The median length of stay was 10 days, and the median intensive care unit length of stay was 3 days. Urgent repair was undertaken in 21.1%; 22.3% were type IV thoracoabdominal aortic aneurysm repairs, and 9.9% were performed for explantation. Our series favored a retroperitoneal approach in the majority of cases (82.5%). The proximal clamp sites were supraceliac (46.1%), suprarenal (29.1%), and infrarenal (24.8%), with approximately a third requiring renal artery reimplantation. The average cross-clamp time was 25.5 ± 14.9 minutes; the mean renal ischemia time for supraceliac and suprarenal clamp sites was 28.4 ± 12.3 minutes and 23.5 ± 12.7 minutes, respectively. Postoperative renal dysfunction occurred in 19.6% of the overall cohort, with 6.2% requiring hemodialysis. Of those requiring postoperative hemodialysis, the majority (75%) received an urgent repair. The in-hospital mortality was 2.3% for elective cases vs 20.9% for urgent repair, and 29.8% of patients were discharged to rehabilitation, with an overall 30-day readmission rate of 7.9%. Over time, there were trends of increased aneurysm repair complexity, with decreasing infrarenal clamp sites, increasing supraceliac clamp sites, increasing proportion of explantations, and increasing need for bifurcated grafts. The acuity of aneurysm repair likewise changed, with the proportion of urgent repairs increasing over time, largely attributable to the rise in explantations. Clamp site influenced the frequency of perioperative complications. Urgent repairs and age at operation were associated with mortality, whereas mortality was not associated with need for explantation and clamp location. ConclusionsAneurysm repair reflected increasing complexity over time, with the need for explantation among urgent repairs significantly on the rise. Urgency and clamp location independently predicted long-term mortality, even after adjustment for age. These findings underscore the changing landscape of open AAA repair in the current era.

Surgical Repair of Juxtarenal Abdominal Aortic Aneurysms and safety of Suprarenal Aortic Clamping.

Juxtarenal abdominal aortic aneurysm (AAA) comprises 15-20% of all AAAs and often requires open surgical repair (OSR) due to anatomical limitations associated with endovascular aneurysm repair (EVAR), particularly in the case of hostile proximal necks. This study aimed to evaluate short- and long-term outcomes of suprarenal clamping during OSR of juxtarenal AAAs and compare the outcomes of this technique with those of infrarenal clamping for AAAs. Between January 1 2014, and December 31 2016, 289 consecutive patients aged ≥40years underwent primary repair for infrarenal AAAs, including 141 OSRs and 148 EVARs. Of the 141 patients, 20 were excluded and totally, 121 patients were included. All patients had fusiform-type AAAs and were divided into infrarenal (N=98) or suprarenal (N=23) clamp groups. The mean follow-up period was 51.4months (95% CI: 48.6-54.2). Mean survival time was 51.4months (95% CI: 48.6-54.2). Thirty-day mortality was 0.8%, and there was no significant difference between two groups (P>.999). Renal complication in infrarenal clamp group was 4.1% and suprarenal clamp group was 4.3% (P>.999). Old age (HR: 1.084; 95% CI: 1.025-1.147; P=.005) and high ASA score (HR: 2.361; 95% CI: 1.225-4.553; P=.010) were substantially associated with in-hospital complications. Although endovascular procedures for repairing juxtarenal AAAs, such as fenestrated EVAR, have been developed, surgical repair is the standard treatment for juxtarenal AAAs. Morbidity and mortality due to open surgery were not higher in the juxtarenal AAA group than in the infrarenal AAA group. Therefore, need for suprarenal clamp should not preclude OSR and also there is continued need for training in surgical exposure of juxtarenal AAA and OSR.

Mid-Term Outcomes of Retroperitoneal and Transperitoneal Exposures in Open Aortic Aneurysm Repair

There have been a number of studies comparing perioperative outcomes of the retroperitoneal (RP) and transperitoneal (TP) approaches to open aortic aneurysm repair (OAR), many of which have shown conflicting results. There remains a paucity of data comparing these 2 exposures beyond 30days. The purpose of this study was to evaluate the mid-term outcomes between RP and TP exposures in OAR. This is a retrospective review of elective OAR from a single institution from 2010 to 2014 with at least oneyear of follow-up. Patients with any prior aortic repair, prior midline TP or RP exposures, prior small bowel obstruction (SBO), or prior abdominal wall hernia repair were excluded. Patients' demographics, comorbidities, intraoperative details, and postoperative variables up to 5years were compared. Primary outcomes were all-cause mortality, aortic or arterial reinterventions, incisional reinterventions, SBO or reintervention for SBO, and composite reintervention. Of the 273 OARs identified, 136 OARs (86 TP and 50 RP exposures) met criteria for the study. The average follow-up was 43.4months. Of the preoperative and intraoperative characteristics, patients with RP exposures were significantly more likely to be female (30% vs. 12.8%; P = .014) and to have larger aneurysm (6.1±1.02cm vs. 5.4±1.01cm; P<.001), tube graft (48% vs 19.8%; P<.001), and renal bypass (30% vs. 2.3%; P<.001). Patients with TP exposures were significantly more likely to have inferior mesenteric artery reimplantation (15.1% vs. 4%; P = .046), infrarenal clamping (65.9% vs. 22%; P<.001), and iliac aneurysm (36% vs. 4%; P<.001). During mid-term follow-up, there was not a difference in all-cause survival at 3years (95.8% vs. 95.8%; P = .52). Although there were more incisional hernias in the TP group (48% vs. 8%; P<.001), there was no difference in incisional reinterventions (14% vs. 6%; P = .36). There were no differences in aortic or arterial reinterventions (5% vs. 4%; P= .86), SBO (7% vs. 0%; P = .99), intervention for SBO (3% vs. 0%; P= .99), or composite reinterventions (16% vs. 10%; P = .6) between the TP and RP exposures. In mid-term follow-up, OAR through TP exposure had more incisional hernias compared with RP exposure. However, there is no difference in mortality or composite reinterventions between approaches.

Minimally Invasive Open Conversion for Late EVAR Failure

With the increasing use of endovascular aortic aneurysm repair (EVAR), open repair after aortic stent grafting is of growing interest. The surgical conversion treatment may be a very challenging process with high mortality and in-hospital complication rates. The aim of this article is to present our experience in patients with EVAR failure treated by minimally invasive open conversion (MOC) and its technical aspects. A retrospective study was conducted on a prospectively compiled computerized database of consecutive patients treated by MOC at our institution between May 2014 and June 2018. Indications for treatment were endoleaks with sac growth at least >5mm in the last 6months and failure of previous endovascular tentative for aneurysm sealing. Demographics of the patients, reason for conversion, previous endovascular procedures, surgical outcomes, and survival were reviewed. MOC was performed by a small abdominal incision, infrarenal clamping, and partial explantation of the endograft in all patients. A total of 10 patients were treated during the study period. The mean interval to MOC after EVAR was 45.1months (range, 14-128). Indications for MOC included type Ia endoleak in three patients (30%), persistent type II EL in four (40%), and type III EL in one patient (10%), indeterminate or type V EL in two (20%). At 30 days, no deaths or reinterventions were reported, and major complication rate was 10% (one postoperative pneumonia). At mean follow-up of 22.9±15.9months, no reinterventions were described. Death rate was (20%) with one aneurysm-related death (10%) for graft infection 32months after MOC and one (10%) cardiac event at 18months. Despite the potential high risk of open conversion, MOC appears to be a safe surgical solution for EVAR failure. This potentially challenging operation may be improved with minimally invasive techniques that are presented.

Open Repair of Proximal Abdominal Aneurysms Analyzed According to the Anatomy, Clamping Site, and Theoretical Fenestrated Endovascular Design

To report our experience with the open repair (OR) of hostile-necked, juxtarenal, pararenal, and suprarenal (SR) aortic aneurysms (proximal abdominal aortic aneurysms) and stratify the results according to the equivalent endovascular repair. Data from all patients treated between 2010 and 2015 were prospectively collected and retrospectively reviewed. Preoperative computed tomographic (CT) scans were analyzed to plan a hypothetical equivalent endovascular approach (2, 3, and 4 fenestrations [FENs]). Postoperative results were recorded based on the cross-clamping level: supraceliac (SC), SR, and infrarenal (IR). Major adverse events (MAEs) were defined as the presence of one of the following: all-cause mortality, bowel ischemia, myocardial infarction, paraplegia, respiratory failure, stroke, and renal insufficiency. One hundred fifty-seven patients were treated; 93 met the CT scan criteria (slice thickness, <1.5mm) and were included in the study. Thirty-day mortality was 2.2% (SC, 7.4%; SR, 0%; IR, 0%) and MAE was 31.2% (SC, 51.9%; SR, 27.3%; IR, 13.6%) in the entire cohort. After endovascular planning, 11 (11.8%) patients would have been treated with a 2-FEN device, 20 3-FEN (21.5%), and 62 4-FEN (66.7%). Only 35.5% of the 4-FEN patients received an SC aortic cross-clamping, whereas 43% SR and 21% IR. Renal/visceral perfusion was performed in 45 (72.5%) 4-FEN patients, and in 20 (64%) 2/3-FEN patients (P<0.001); renal/visceral revascularization was needed in 23 (37.1%) 4-FEN and 5 (19.2%) 2/3-FEN patients (P=0.054). Implementing a fenestrated endovascular aortic repair (FEVAR) endovascular program could reduce MAEs, but it must be clear that FEVAR for juxtarenal disease may overcomplicate treatment and include manipulation of visceral vessels that would not need to be affected if IR clamping is possible in OR, when it gives excellent results.

Midterm Outcomes of Retroperitoneal and Transperitoneal Exposures in Open Aortic Aneurysm Repair

There have been a number of studies comparing perioperative outcomes of the retroperitoneal (RP) and transperitoneal (TP) approach to open aortic aneurysm repair (OAR), many of which have shown conflicting results. There remains a paucity of data comparing these two exposures beyond 30 days. The purpose of this study was to evaluate the midterm outcomes between RP and TP exposures in OAR. This is a retrospective review of elective OAR from a single institution from 2010 to 2014 with at least 1 year of follow-up. Patients with any prior aortic repair, prior midline TP or RP exposures, prior small bowel obstruction (SBO), or prior abdominal wall hernia repair were excluded. Patients’ demographics, comorbidities, intraoperative details, and postoperative variables up to 5 years were compared. Primary outcomes were all-cause mortality, aortic or arterial reinterventions, incisional reinterventions, SBO or reintervention for SBO, and composite reintervention. Of the 273 OARs identified, 136 OARs (86 TP and 50 RP exposures) met criteria for the study. The average follow-up was 43.4 months. Of the preoperative and intraoperative characteristics, patients with RP exposures were significantly more likely to be female (30% vs 12.8%; P = .014) and to have larger aneurysm (6.1 ± 1.02 cm vs 5.4 ± 1.01 cm; P < .001), tube graft (48% vs19.8%; P < 0.001), and renal bypass (30% vs 2.3%; P < .001). Patients with TP exposures were significantly more likely to have inferior mesenteric artery reimplantation (15.1% vs 4%; P = .46), infrarenal clamping (65.9% vs 22%; P < .001), and iliac aneurysm (36% vs 4%; P < .001). During midterm follow-up, there was not a difference in all-cause survival at 3 years (95.8% vs 95.8%; P = .52). Although there were more incisional hernias in the TP group (48% vs 8%; P < .001), there was no difference in incisional reinterventions (14% vs 6%; P = .36). There were no differences in aortic or arterial reinterventions (5% vs 4%; P = .86), SBO (7% vs 0%; P = .99), intervention for SBO (3% vs 0%; P = .99), or composite reinterventions (16% vs 10%; P = .6) between the TP and RP exposures. In midterm follow-up, OAR through TP exposure had more incisional hernias compared with RP exposure. However, there is no difference in mortality or composite reinterventions between approaches.

Infrarenal endograft clamping in late open conversions after endovascular abdominal aneurysm repair

ObjectiveThe aim of this study was to report the technical aspects and outcomes of late open conversion (LOC) after endovascular aneurysm repair (EVAR) in a single center by using exclusively infrarenal clamping of the endograft as an alternative to suprarenal or supraceliac aortic clamping. MethodsA retrospective analysis of EVAR requiring late explantation (>30 days) from January 1996 to October 2016 was performed. Patients' demographics, type of endograft, duration of implantation, reason for removal, extent of stent graft removal, type of reconstruction, 30-day mortality, postoperative complications, and long-term survival were obtained for analysis. ResultsDuring the study period, 28 patients required LOC. The mean age at conversion was 75.11 ± 6.65 years; 26 of 28 (92.86%) were male. Grafts were excised after a median of 41.4 months (range, 5.97-112.67 months), with 21 of 28 explantations (75%) performed electively. Multiple types of EVAR devices have been explanted; suprarenal fixation was present in 75% of the cases. The indication for LOC was the presence of an endoleak in 27 cases (20 type I, 4 type II associated with aneurysm growth, 3 type III, and 3 endotensions; in 3 cases, multiple types of endoleak were present) and graft thrombosis in 1 case. All patients underwent a transperitoneal approach with infrarenal clamping. No patient required revascularization of visceral or renal vessels. Complete removal of the stent graft was performed in 8 of 28 cases, partial removal in the remaining 20 cases (with conservation of the proximal portion in 16 of 20 cases). Technical success was 100%. Overall 30-day mortality was 7.14% (2/28). The 30-day mortality was 9.5% in elective patients and 0% in the urgent setting; this difference was not statistically significant (P = .56). Postoperative kidney injury rate was 7.7% (2/26). Mean follow-up was 47.37 ± 55.67 months (range, 0.23-175.07 months). The estimated 5-year survival rate was 78%. No aneurysm-related death or additional procedure occurred during follow-up. ConclusionsLOC after EVAR using infrarenal clamping of the endograft is a feasible and effective technique, with satisfactory postoperative mortality and morbidity. This method allows simplification of the surgical technique and may avoid renal and visceral complications related to suprarenal or supraceliac clamping.

Comparison of Multifurcated and Composite Vascular Grafts for Abdominal Aortic Aneurysms with Iliac Arterial Lesions

Introduction: Reconstructing the internal iliac artery (IIA) may help to prevent pelvic ischemia during open repair of abdominal aortic aneurysms (AAAs) with iliac arterial lesions. Composite grafts combined with Y-shaped and straight vascular grafts have previously been used to reconstruct the IIA. However, multifurcated vascular grafts have recently been used to treat AAAs with iliac arterial lesions. We, therefore, assessed the viability of multifurcated vascular grafts for AAAs with iliac arterial lesions. Materials and Methods: We retrospectively reviewed 87 patients who underwent elective open repair with reconstruction of IIAs under infrarenal clamp for AAAs with iliac arterial lesions between April 2002 and August 2015. Forty-three patients received multifurcated vascular grafts including 23 patients who underwent reconstructed unilateral IIA, and 44 patients received composite grafts including forty patients with reconstructed unilateral IIA. We compared the multifurcated and composite graft groups among all patients and also compared among patients who underwent unilateral IIA reconstruction. Results: There were no significant differences between the two groups among all patients in terms of intra- and post-operative data. There were no cases of hospital death or buttock claudication. In propensity score matching analysis among patients with unilateral IIA reconstruction, 22 patients were extracted each group. There were no significant differences in any preoperative or perioperative parameters between the groups. Conclusions: We could not show the availability of open repair using multifurcated vascular grafts for AAA with iliac arterial lesions with comparable results compared to composite grafts.

On the complexity of screening detected abdominal aortic aneurysms: a retrospective observational multicenter cohort study.

Ultrasound screening for abdominal aortic aneurysms (AAA) has been shown to decrease aneurysm related mortality. Likely by providing an opportunity to intervene while the aneurysm is still intact, but possibly also when and the anatomy still relatively uncomplicated which would provide a less complex procedure. Our aim was to retrospectively investigate the complexity of repair for screening-detected AAAs in a cohort of 65-year-old men. All screening detected AAA cases that underwent repair between Sept 2010 and June 2014 in the most southern region of Sweden were included. Procedures were classified as either standard or complex. A standard procedure was defined as either standard EVAR (endovascular aneurysm repair) within the manufacturers Instructions For Use (IFU) or open repair with infrarenal clamping followed by a tube graft repair. All other types of procedures were defined as complex. The prevalence rate of AAA, screening compliance, short- and midterm outcome of the operations were reported. From the 35513 men invited to screening, 27 951 (78.7%) attended screening with ultrasound. AAA≥30 mm was found in 561 cases, yielding a prevalence rate of 2.0%. Forty-eight patients underwent AAA repair. A percentage of 43.8% of these were classified as complex procedures. These consisted mostly of branched/fenestrated EVAR or EVAR with simultaneous exclusion of common iliac aneurysm. Our study confirms contemporary prevalence rates of AAA. Almost half (43.8%) of screening-detected AAA required complex operations, a significant proportion. The complex aneurysms were, on average, larger than the non-complex cases and they were more likely to be cases that required surgery immediately after screening detection. Our data suggests that the nature of AAA is heterogenous, even in the screening-detected group requiring operation. This should spur interest in more studies to investigate this issue.