Suprarenal Aortic Cross-clamping Research Articles

A study of mortality frequency and clinical course of postoperative renal and abdominal visceral complications following open aortic surgery for abdominal aortic aneurysm requiring supra renal aortic cross-clamp

ABSTRACT Background: Endovascular interventions for abdominal aortic aneurysms (AAAs) are fast evolving; however, due to higher rates of reintervention and no survival benefits after 2 years, open surgical procedures are pivotal. Here, we present mortality and morbidity analysis of open surgical procedures requiring suprarenal cross clamping for AAA repair. Materials and Methods: The present study is a retrospective hospital record-based study selecting 34 cases that required suprarenal cross-clamping out of 200 abdominal aortic aneurysm surgeries. Out of the total 34 patients, 22 (64.7%) were males and 12 (35.3%) were females. The mean age of all participants was 58.05 years (with an 8.1 standard deviation). Out of 34 cases, 20 cases (58.8%) were classified as suprarenal and pararenal aneurysms and 14 cases were juxtarenal aneurysms (41.2%). Out of the 14 juxtrarenal aneurysm cases, 7 (50%) were atherosclerotic and 2 (14.3%) were Marfan’s Syndrome, while inflammatory were 2 (14.3%) and infected were 2 (14.3%) and 1 was a case of Takayasu’s arteritis (7.1%). Mortality and morbidity, including renal function decline, need for hemodialysis, acute pancreatitis, and hepatic and gastrointestinal (GI) complications, were recorded as early (up to 30 days) and late (up to 1 year). The results were recorded separately for suprarenal, pararenal, and juxtarenal aneurysm types and presented in that way, which is the highlight of our study. Results: Early mortality occurred in 3/34 (8.8%) cases, where late mortality happened in 2/34 (5.9%) cases, which are exclusive of early mortality cases. Considering the early mortality and complications, 2 out of 4 cases (50.0%) of the suprarenal group died early, renal dysfunction happened in 4/34 cases (11.8%), of which 3 (8.8%) required dialysis. No cases of pancreatitis, while acute liver failure complicated 3 out of 34 (8.8%) cases. GI bleed and mesentric ischemia each complicated 2 out of 34 cases (5.9%). Prolonged ileus was noticed as the most common GI complication complication. Early mortality was highest in the suprarenal group with renal dysfunction. Considering late mortality and complications, 1 out of 16 cases (6.3%) of the pararenal group died late, and 1 out of 14 cases (7.1%) of the juxta renal cases died late. There was no late mortality in the suprarenal group. Renal dysfunction happened in 2/34 cases (5.9%), of which none required dialysis. Complete data have been presented as per the aneurysm type. Conclusions: Patients requiring suprarenal aortic cross-clamping for open surgical repair of abdominal aorta aneurysm are usually high-risk surgical candidates, considering both early and late mortality and morbidity. Early mortality was maximum in the suprarenal group (50.0%), as were postoperative renal dysfunction and hemodialysis requirements. Visceral complications (acute liver failure and GI complications) were also maximum with the suprarenal group. Late mortality was recorded in the pararenal and juxtarenal groups, with renal dysfunction being recorded in the suprarenal and juxtarenal groups. Visceral complications were recorded in both pararenal and juxtarenal groups. One confounding factor could be the high early mortality in the suprarenal group, resulting in less number of survivors for late postoperative recording. Overall, we conclude that suprarenal aortic aneurysms carry the highest burden of early mortality with renal and visceral complications postoperative.

Long-term results of open surgical repair of non-infrarenal abdominal aortic aneurysms

Introduction: Solid evidence is not available on the ideal technique of surgical repair (open or endovascular) of noninfrarenal abdominal aortic aneurysms. Objective: Our aim was to analyze the postoperative effect of mortality and the level of proximal cross-clamping of the patients who underwent open surgical aortic repair of non-infrarenal abdominal aortic aneurysms with intact wall. Method: This is a retrospective, single-centre study, which reviews the results of open surgical repair, performed for intact non-infrarenal abdominal aorta aneurysms between 2005 and 2017. Aneurysms were analyzed in two groups, based on the level of aortic cross-damping: juxta-pararenal aortic aneurysm group with inter- or suprarenal aortic cross-clamping and suprarenal aortic aneurysm group with supraceliac aortic cross-clamping. Primary endpoints were 30-day, 1-, 2- and 5-year mortality. Secondary endpoints were postoperative acute kidney injury, including hemodialysis, and major postoperative complications. Results: In our clinic, 94 patients underwent open surgical aortic repair with cross-clamping above at least one renal artery. The median follow-up was 3.14 (1.55-5.00) years. The overall 30-day, 1-, 2- and 5-year mortality were 9%, 20%, 27% and 48%, respectively. The mortality was significantly lower in the juxta/pararenal abdominal aortic aneurism group at 30 day and 1 year. The overall perioperative incidence of acute kidney injury was 54% and 30% at discharge. Significantly more in-hospital acute renal dysfunction was noticed in the patients with suprarenal aortic aneurysm than with juxta/pararenal aneurysm, however, the difference was not significant at discharge. Major postoperative complications were more frequent in the suprarenal aneurysm group. Conclusion: Open surgical repair of abdominal aortic aneurysms with supraceliac aortic cross-clamping is associated with significantly higher morbidity, early and mid-term mortality than the repair of juxta/pararenal aneurysms. Chronic kidney disease and major postoperative complications are independent factors of mid- and long-term mortality.

Effects of Suprarenal Aortic Cross-Clamping and Adjunctive Renal Reconstruction on Outcomes of Open Abdominal Aortic Aneurysm Repair.

Purpose: To analyze our contemporary experience in open abdominal aortic aneurysm (AAA) repair. We focused on the effects of suprarenal (SR) aortic cross-clamping and adjunctive renal reconstruction (RR) on postoperative outcomes.Methods: We retrospectively reviewed our institutional data of 141 consecutive patients who received elective open AAA repair between January 2014 and December 2020.Results: Seventy-five procedures were performed with SR aortic cross-clamping, 20 of which required an adjunctive RR. Patients in the SR group had a higher incidence of postoperative acute kidney injury (AKI) (18.7% vs. 7.6%, P = 0.045). There were no significant between-group differences in other major complications. The 30-day mortality rate in the infrarenal (IR) and SR groups was 0% and 1.3%, respectively. After a median follow-up of 33 months, the rates of chronic renal decline in the IR (18.2%) and SR (21.3%) groups were similar. All reconstructed renal arteries were patent without reintervention. The 5-year overall survival rate in the IR and SR groups was 88.8% and 83.2%, respectively.Conclusions: SR aortic cross-clamping was associated with postoperative AKI but neither SR aortic cross-clamping nor RR affected the long-term renal function or mortality. Open repair remains an essential option for patients with AAA, especially those with complex anatomy.

Early and midterm outcomes following open surgical conversion after failed endovascular aneurysm repair from the "Italian North-easT RegIstry of surgical Conversion AfTer Evar" (INTRICATE).

To report the early and mid-term outcomes following open surgical conversion (OSC) after failed endovascular aortic repair (EVAR) using data from a multicentric registry. A retrospective study was carried out on consecutive patients undergoing OSC after failed EVAR at eight tertiary vascular units from the same geographic area in the North-East of Italy, from April 2005 to November 2019. Study endpoints included early and follow-up outcomes. A total of 144 consecutive patients were included in the study. Endoleaks were the most common indication for OSC (50.7%), with endograft infection (24.6%) and occlusion (21.9%) being the second most prevalent causes. The overall rate of 30-day all-cause mortality was 13.9% (n= 20); 32 patients (22.2%) experienced at least one major complication. Mean length of stay was 13± 12.7days. On multivariate logistic regression, age (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.01-1-19; P= .02), renal clamping time (OR, 1.07; 95% CI, 1.02-1.13; P= .01), and suprarenal/celiac clamping (OR, 6.66; 95% CI, 1.81-27.1; P= .005) were identified as independent predictors of perioperative major complications. Age was the only factor associated with perioperative mortality at 30days. Renal clamping time >25minutes had sensitivity of 65% and specificity of 70% in predicting the occurring of major adverse events (area under the curve, 0.72; 95% CI, 0.61-0.82). At 5years, estimated survival was significantly lower for patients treated due to aortic rupture/dissection (28%; 95% CI, 13%-61%), compared with patients in whom the indication for treatment was endoleak (54%; 95% CI, 40%-73%), infection (53%; 95% CI, 30%-94%), or thrombosis (82%; 95% CI, 62%-100%; P= .0019). Five-year survival rates were significantly lower in patients who received emergent treatment (28%; 95% CI, 14%-55%) as compared with those who were treated in an urgent (67%; 95% CI, 48%-93%) or elective setting (57%; 95% CI, 43%-76%; P= .00026). Subjects who received suprarenal/celiac (54%; 95% CI, 36%-82%) or suprarenal (46%; 95% CI, 34%-62%) aortic cross-clamping had lower survival rates at 5years than those whose aortic-cross clamp site was infrarenal (76%; 95% CI, 59%-97%; P= .041). Using multivariate Cox proportional hazard, older age and emergency setting were independently associated with higher risk for overall 5-year mortality. OSC after failed EVAR was associated with relatively high rates of early morbidity and mortality, particularly for emergency setting surgery. Endoleaks with secondary sac expansion were the main indication for OSC, and suprarenal aortic cross-clamping was frequently required. Endograft infection and emergent treatment remained associated with poorer short- and long-term survival.

The Influence of Suprarenal Aortic Cross-clamping on Perioperative and Follow-up Results of Open Repair of Abdominal Aortic Aneurysm

The objective was to retrospectively assess the perioperative and long-term outcomes in patients operated on with open repair of abdominal aortic aneurysm (AAA) with or without suprarenal aortic cross-clamping in a single-center experience. From January 2008 to December 2018, 1608 consecutive open and endovascular interventions for AAA were performed. Data concerning these interventions were prospectively recorded; a retrospective analysis of the database was performed and 540 elective open interventions for unruptured AAA were found, in 73 cases with suprarenal aortic cross-clamping (group 1) and in 467 cases with infrarenal aortic cross-clamping (group 2). The two groups were compared in terms of clinical, anatomic, and surgical characteristics and perioperative (<30 days) outcomes with χ2 test; follow-up results were compared with Kaplan-Meier curves and log-rank test. There were no differences between the two groups in terms of demographics, risk factors, and comorbidities, except for a higher percentage of female patients in group 1 than in group 2 (16.2% and 9.1%, respectively; P = .05). Mean preoperative estimated glomerular filtration rate was similar in the two groups as well. Most patients in both groups had a bifurcated aortobi-iliac graft; in group 1, 22 patients had a unilateral or bilateral renal revascularization, whereas in 51 cases, the ostium of one or both renal arteries was included in the proximal anastomosis. The mean time of renal ischemia in group 1 was 16 ± 12 minutes. Patients in group 1 had a longer time of intensive care unit stay than patients in group 2, but the overall length of stay was similar. Perioperative mortality rates were 4.1% in group 1 and 2.7% in group 2 (P = .5); nonfatal major complications occurred in 14 patients in group 1 (19%) and in 69 patients in group 2 (14.5%; P = .3). Follow-up was available in 512 patients (95%), with a median duration of 48 months (range, 1-144 months). Estimated 7-year survival rates were 51.5% in group 1 and 76.5% in group 2 (P < .001; log-rank, 15.3), whereas the corresponding figures in terms of freedom from AAA-related complications were 63.5% and 85.5% (P = .002; log-rank, 9.5). Moreover, patients in group 1 were more likely than patients in group 2 to undergo a reintervention at 7-year follow-up. In patients with complex AAA requiring suprarenal aortic cross-clamping, a significant increase of long term mortality, AAA-related complications, and reintervention was found in comparison with patients undergoing infrarenal aortic clamping.

Early Postoperative Renal Dysfunction Predicts Long-Term Renal Function Degradation after Type IV Thoracoabdominal Aortic Aneurysm Surgical Repair

Type IV thoracoabdominal aortic aneurysm surgical repair is often complicated by postoperative acute kidney injury. The aim was to evaluate early renal injury influence on long-term renal function. All type IV thoracoabdominal surgical repair performed between January 2000 and January 2014 in our tertiary hospital were included in this retrospective observational study. All procedures were performed through a retroperitoneal approach with at least suprarenal aortic cross-clamping. Cold Ringer Lactate was used to perfuse the kidneys. Serum creatinine (Scr.) and glomerular filtration rate (GFR) were recorded preoperatively, daily until discharge and at least annually during follow-up. Postoperative renal dysfunction was classified using the RIFLE score. Predictors of long-term renal decline were identified by logistic regression and a Cox model. Of total, 80 patients were included. Aortic clamping level was suprarenal (10%), supramesenteric (37%) or supracoeliac (53%). Ischemic durations were 29±9min for the gastrointestinal tract and the right kidney, 54±28min for the left kidney. Three patients died postoperatively. At discharge, 31 (38.8%) patients did not have a postoperative renal impairment (RIFLE-), compared with 49 (61.2%) who had a renal dysfunction (RIFLE+). GFR was 89±29ml/min vs 68±37ml/min, respectively (P<0.01). In the RIFLE+group, Scr. was increased by x1.5 (Risk) for 22 patients, x2 (Injury) for 19 patients, and ×3 (Failure) for 8 patients. Mean follow-up was 59months. Eighteen patients died, and 2 patients started permanent dialysis at 46 and 118months during follow-up. The only predictive factor of long-term GFR degradation was a postoperative GFR below 45ml/min (OR: 16.5; 95%; P<0.001). Postoperative renal dysfunction was a frequent complication, associated with long-term renal function degradation.

Surgeon experience association with patient selection and outcomes after open abdominal aortic aneurysm repair

BackgroundGrowing calls for guidelines advocating minimum annual case volumes for surgeon credentialing remain controversial. Although most attention to date has focused on the impact of obligatory case volume, less attention has been devoted to the more complex association between surgeon years of independent practice experience and procedure outcomes after open abdominal aortic aneurysm repair (OAR). Therefore, the purpose of this study was to explore the association of surgeon experience with case selection and real-world outcomes after OAR. MethodsAll Society for Vascular Surgery-Vascular Quality Initiative infrarenal and juxtarenal OARs (n = 11,900; 71% elective; 29% nonelective) from 2003 to 2019 were examined. Surgeon experience was defined by years in practice after training completion. Experience level at time of repair was categorized (≤5 years, n = 1048; 6-10 years, n = 1309; 11-15 years, n = 1244; and ≥16 years, n = 4772) and intergroup univariate comparisons were made. Logistic regression identified independent predictors of complications, 30-day death, and 1-year mortality. Models were constructed with or without surgeon experience strata to determine association with outcomes. ResultsIncreasing surgeon experience was associated with performing greater proportions of elective procedures, whereas less experienced surgeons had disproportionate exposure to nonelective operations (elective, 73% ≥16 years vs 62% ≤5 years [P < .0001]; nonelective, ≤5 years, 38% vs 27%, ≥16-years [P < .0001]). Among surgeons who perform five or fewer cases per year, the risk of any aggregate major complication after elective OAR decreased significantly as experience increased (P = .0004), although no differences were detected in nonelective cases or among higher volume surgeons. Similarly, the risk of in-hospital death decreased with increasing experience (P = .004), but only among low-volume surgeons performing elective procedures. Comorbidities were similar across all experience strata for both elective and nonelective presentations; however, more experienced surgeons operated on higher proportions of nonelective patients with coronary disease (P = .04). Early career surgeons more frequently operated on patients with American Society of Anesthesiologists IV designation, larger abdominal aortic aneurysm diameters and used suprarenal/celiac cross-clamps more frequently than later career surgeons. The 1-year survival after elective and nonelective OAR was not impacted by surgeon experience (Ptrend > .15 for all comparisons). ConclusionsIncreasing surgeon years of practice experience correlated significantly with a reduced risk of developing multiple postoperative complications, including postoperative death in the elective setting. Surgeons within their first 5 years of practice are exposed to greater proportions of nonelective cases but seem to have similar outcomes after these repairs compared with surgeons with more experience. Notably, surgeons in their first 5 years of practice operate on more complex elective patients as underscored by higher aggregate comorbidity scores, larger aneurysm diameters, and need for suprarenal aortic cross-clamping. These data have important implications on training paradigms, faculty recruitment, and the organization of mentorship when on boarding new surgeons.

What Did Endovascular Aortic Repair Bring for the Treatment Strategy of Abdominal Aortic Aneurysm?

Objective: We examined the effects of the introduction of endovascular aortic repair (EVAR) on treatment for abdominal aortic aneurysms (AAAs).Subjects: We compared patients in the following three periods: period I (January 2002–December 2006, 105 patients), period II (January 2007–December 2011, 242 patients, duration of 5 years after the introduction of EVAR), and period III (January 2012–December 2016, 237 patients, duration of 5 years after period II). We used the American Society of Anesthesiologists (ASA) classification for risk assessment.Results: In the Open repair (OR) group, the incidences of ASA class 2 increased and classes 3 and 4 decreased significantly in periods II and III compared with period I. In all periods, there were no in-hospital deaths. Suprarenal aortic cross-clamping was required in 18 patients (19.1%) in period III and 5 patients (6.3) in period I, and the difference was significant (P<0.05). In the EVAR group, no differences in age, sex, or ASA classification class were observed between periods II and III. In period II, one patient died due to aneurysm rupture during surgery. Significant differences were observed when comparing both groups in periods II and III: patients in the EVAR group were older (P<0.01) and the OR group had a higher proportion of ASA class 2 patients and the EVAR group had a higher proportion of ASA class 3 or 4 patients (P<0.01). Among all AAA surgeries, rupture occurred in 25 patients (23.8%) in period I, 18 patients (7.4) in period II, and 16 patients (6.8) in period III. The number of ruptures was significantly lower in periods II and III than in period I (P<0.01).Conclusions: The findings of this study suggest that EVAR should be indicated for high-risk patients and had the good outcome of AAA treatment. (This is a translation of Jpn J Vasc Surg 2018; 27: 27–32.)

Long-term results after open repair of inflammatory infrarenal aortic aneurysms

ObjectiveThe objective of this study was to investigate the long-term outcome after open repair of inflammatory infrarenal aortic aneurysms. MethodsA total of 62 patients (mean age, 68.9 ± 8.8 years; 91.9% male) undergoing open surgery for inflammatory aortic aneurysm from 1995 until 2014 in a high-volume vascular center were retrospectively evaluated. The patients' demographics, preoperative and postoperative clinical characteristics, imaging measurements, and procedural data were collected. Study end points were preoperative and postoperative sac diameter, evolution of periaortic fibrosis and development of hydroureteronephrosis detected by computed tomography (CT) scan, and mortality and morbidity after 30 days and at the time of maximum follow-up. ResultsThe mean abdominal aortic aneurysm diameter was 67.3 ± 16.7 mm. A total of 30 patients (48.4%) were asymptomatic, 27 patients (43.5%) were symptomatic, and 5 patients (8.1%) were treated for ruptured aneurysm. In 25 patients (40.3%), an aorta-aortic tube graft was implanted; in 37 patients (59.7%), an aortic bifurcation graft was used. Median operating time was 208 minutes (range, 83-519 minutes). Median aortic clamping time was 31 minutes (range, 14-90 minutes); in 25 patients (40.3%), suprarenal aortic cross-clamping was necessary. Hydroureteronephrosis was preoperatively diagnosed by CT scan in 16 patients (25.8%), with the need for a ureteral stent in 11 patients (17.7%). Aneurysm- and procedure-associated 30-day mortality was 11.3% (n = 7), with septic multiple organ failure in four patients and cardiac arrest in three patients. The overall perioperative complication rate was 33.9% (n = 21 patients). Median follow-up was 71.0 months (range, 0.2-231.6 months). At 1 year, 2 years, 4 years, and 6 years, overall survival was 83.4%, 79.6%, 79.6%, and 72.6%, respectively. Six patients (9.7%) required a reintervention during follow-up, predominantly aneurysm related and caused by aortoenteric fistula and graft infection (three of five patients). Median maximum thickness of preoperative perianeurysmal inflammation on CT was 10 mm (range, 2-22 mm), which decreased in 15 of 16 (94%) patients with available postoperative CT scans. Postoperative median thickness of perianeurysmal inflammation on CT was 6 mm (range, 0-13 mm). Hydroureteronephrosis persisted in two of nine (22.2%) patients at the end of follow-up. ConclusionsSurgery in patients with inflammatory abdominal aortic aneurysms is associated with a substantial amount of perioperative complications. After surgery, the perianeurysmal inflammation decreases in most patients on follow-up CT. However, because the inflammatory process does not totally resolve, patients require lifelong surveillance for hydroureteronephrosis and development of aortoenteric fistulas.

Beneficial effects of inhaled nitric oxide with intravenous steroid in an ischemia-reperfusion model involving aortic clamping.

This study evaluated the effects of inhaled nitric oxide (iNO) therapy combined with intravenous (IV) corticosteroids on hemodynamics, selected cytokines, and kidney messenger RNA toll-like receptor 4 (mRNA TLR4) expression in ischemia–reperfusion injury animal model. The primary endpoint was the evaluation of circulatory, respiratory, and renal function over time. We also investigated the profile of selected cytokines and high-mobility group box 1 (HMGB1) protein, as well as renal mRNA TLR4 activation determined by quantitative real-time polymerase chain reaction analysis. Pigs (n = 19) under sevoflurane AnaConDa anesthesia/sedation were randomized and subjected to abdominal laparotomy and alternatively suprarenal aortic cross-clamping (SRACC) for 90 min or sham surgery: Group 1 (n = 8) iNO (80 ppm) + IV corticosteroids (25 mg ×3) started 30 min before SRACC and continued 2 h after SRACC release, followed with decreased iNO (30 ppm) until the end of observation, Group 2 (n = 8) 90 min SRACC, Group 3 (n = 3)—sham surgery. Renal biopsies were sampled 1 hr before SRACC and at 3 and 20 h after SRACC release. Aortic clamping increased TLR4 mRNA expression in ischemic kidneys, but significant changes were recorded only in the control group (P = 0.016). Treatment with iNO and hydrocortisone reduced TLR4 mRNA expression to pre-ischemic conditions, and the difference observed in mRNA expression was significant between control and treatment group after 3 h (P = 0.042). Moreover, animals subjected to treatment with iNO and hydrocortisone displayed an attenuated systemic inflammatory response and lowered pulmonary vascular resistance plus increased oxygen delivery. The results indicated that iNO therapy combined with IV corticosteroids improved central and systemic hemodynamics, oxygen delivery, and diminished the systemic inflammatory response and renal mRNA TLR4 expression.

Technique for treating complex aneurysms with Hercules stent graft modified by the surgeon

Endovascular treatment of thoracoabdominal aneurysms with fenestrated stent grafts expands its applicability because of good technical results. However, stent graft customization requires an average of 6 to 12 weeks, which makes this technique ineligible for symptomatic or ruptured aneurysms. Authors advocate perioperative fenestration by the surgeon, allowing this technique to be used for emergency cases with good results and favorable prognosis. This article describes a technique for intraoperative changes of the Hercules stent graft (MicroPort Scientific Corporation, Shanghai, China) to include the ostia of visceral arteries by making fenestrations and scallops, with a temporary diameter-reducing wire as a further modification to facilitate positioning and catheterization of fenestrations with guidewires.

Circumferential Aortic Endarterectomy Followed with Immediate Infrarenal Clamping Obviates Suprarenal Clamping for Juxtarenal Aortoiliac Occlusion

Traditional open surgery for juxtarenal aortoiliac occlusive disease (AIOD) requires suprarenal aortic cross-clamping (SRCC), which is associated with high incidence of acute kidney injury (AKI). This study was to compare the outcomes of circumferential aortic endarterectomy followed by immediate infrarenal cross-clamping (IRCC) with the traditional approach of SRCC during surgery for juxtarenal AIOD. A 10-year retrospective review of 87 patients who underwent open surgery for AIOD at our University Medical Center was performed. There were 52 males and 35 females (mean age of 52years). Multivariate analysis was performed to assess operative time, blood loss, incidence of AKI, 30-day mortality, and recurrent aneurysm/pseudoaneurysm. Thirty-seven patients were found to have juxtarenal AIOD, which were divided into SRCC (n=25) and IRCC (n=12). Ten patients from the SRCC developed AKI versus 1 from the IRCC (30% vs. 8.3%, P=0.04). SRCC demonstrated increased blood loss (1,681 vs. 591mL, P=0.004). Mean operative time was less in the IRCC group (5 vs. 7hr, P=0.0001). Thirty-day mortality in the SRCC group was 1 and 0 in the IRCC group, respectively. Recurrent aneurysm or pseudoaneurysm was not identified in endarterectomized aorta up to 4-year follow-up. Circumferential aortic endarterectomy followed with immediate IRCC is a feasible, safe, and effective approach for juxtarenal AIOD in properly selected patients. It may be associated with lower rates of AKI, intraoperative bleeding, operating room time, and length of hospital stay, when compared with the traditional SRCC.

Remote Ischemic Preconditioning May Attenuate Renal Ischemia-Reperfusion Injury in a Porcine Model of Supraceliac Aortic Cross-Clamping

Aim: The effect of remote ischemic preconditioning (RIPC) in decreasing renal ischemia-reperfusion injury (IRI) during a suprarenal aortic cross-clamping was examined in a swine model. Materials and Methods: Four groups of pigs were examined: (a) ischemia-reperfusion (IR) group, renal IRI produced by 30 min of supraceliac aortic cross-clamping; (b) RIPC I group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (15 min ischemia and 15 min reperfusion); (c) RIPC II group, the same renal IRI following RIPC by brief occlusion of the infrarenal aorta (3 cycles of 5 min ischemia and 5 min reperfusion); (d) sham group. Renal function was assessed before and after IRI by examining creatinine, neutrophil gelatinase-associated lipocalin (NGAL), TNF-α, malondialdehyde (MDA), cystatin C and C-reactive protein (CRP) from renal vein blood samples at specific time intervals. Results: Both RIPC groups presented significantly less impaired results compared to the IR group when considering MDA, cystatin C, CRP and creatinine. Between the two RIPC groups, RIPC II presented a better response with regard to CRP, NGAL, TNF-α, MDA and cystatin C. Conclusions: Remote IR protocols and mainly repetitive short periods of cycles of IR ameliorate the biochemical kidney effects of IRI in a model of suprarenal aortic aneurysm repair.

Increasing efficacy of endovascular recanalization with covered stent graft for TransAtlantic Inter-Society Consensus II D aortoiliac complex occlusion

We compared the outcomes and the durability of endovascular recanalization (EVR) with the Viabahn (W.L.Gore and Associates, Flagstaff, Ariz) covered stent graft vs traditional aortobifemoral or aortofemoral bypass grafting for complex aortoiliac occlusions. Between 2008 and 2014, 11 unilateral iliac occlusions and 11 aortobiiliac occlusions were treated by EVR. Also collected were data from the last 21 consecutive patients treated in the same period by aortofemoral (n= 6) or aortobifemoral (n= 15) bypass grafting. In accordance with the TransAtlantic Inter-Society Consensus II (TASC II) document, only patients with type D lesions were considered. Kaplan-Meier estimates for patency were calculated, and Cox proportional hazard modeling was performed. The difference in risk factors between the groups was not significant. General anesthesia was required in 100% of the surgical group, and local or locoregional anesthesia was used for EVR. Suprarenal aortic cross-clamping was required in nine of the open surgical procedures (41%). A brachial percutaneous approach was performed in all patients undergoing EVR, and technical success was 100% in both groups. All of the attempts at EVR were successful. At the 2-year follow-up, primary patency did not differ significantly between the endovascular (91%) and surgical (95%) groups. This was seen in the univariate model (hazard ratio [HR], 0.27; 95% confidence interval [CI], 0.02-2.95; P= .28) and in the multivariate model (HR, 0.77; 95% CI, 0.06-10.07; P= .84) for group (HR, 0.58; 95% CI, 0.04-7.72; P= .68), age (HR, 0.89; 95% CI, 0.73-1.08; P= .24), symptoms (HR, 1.98; 95% CI, 0.42-9.46; P= .39), and occlusion (HR, 3.22; 95% CI, 0.51-20.35; P= .21). The average hospital length of stay was shorter for patients treated with ERV than for those treated with open surgery (3.9± 2.2 vs 5.8± 3.1days, respectively; P= .03). The complication rate was 4% for EVR vs 18% in the surgical group (P= .32). At 2years of follow-up, the results of endoluminal bypass grafting with the Viabahn stent to treat complex aortoiliac disease are promising. Longer-term results are needed to fully evaluate the potential benefits and longer-term patency.

Left Minilaparotomy and Suprarenal Aortic Cross-Clamping: A Safe Procedure on Renal Function

Left Minilaparotomy and Suprarenal Aortic Cross-Clamping: A Safe Procedure on Renal Function

Simultaneous investigation of hemodynamic, microcirculatory and arterio-venous micro-rheological parameters in infrarenal or suprarenal aortic cross-clamping model in the rat

We aimed to investigate hemodynamic, microcirculatory and hemorheological consequence of infrarenal or suprarenal aortic cross-clamping (IRAXC, SRAXC) in the rat. We hypothesized that the magnitude of the changes are different. Twenty-one male rats were randomized into Control, IRAXC or SRAXC groups. Under anesthesia the right carotid artery was cannulated for monitoring heart rate and mean arterial pressure, then median laparotomy was performed. In AXC groups the abdominal aorta and the caudal caval vein were atraumatically clamped for 60 minutes below or above the renal vessels. Before and just after the ischemia, in the 30th and 60th minutes of the reperfusion besides hemodynamic test, laser Doppler flowmetry was used on the liver's, small-intestine's and the kidney's surface, then arterial (cannulated carotid artery) and venous (lateral tail vein) blood samples were taken for determining hematological, acid-base, erythrocytes' deformability, osmoscan and aggregation parameters. We found that when hemodynamic changes were prominent, microcirculatory or hemorheological parameters did not show such large differences. However, every parameter changed in various manners, showing more or less differences between IRAXC and SRAXC groups. Although the largest deviations were observable in SRAXC group, the acid-base and hemodynamic alterations were much more expressed than the micro-rheological ones. Further investigations of in vivo relations-correlations of changes in hemodynamic, microcirculatory, metabolic and hemorheological factors need further studies providing simultaneous monitoring possibilities.

Pharmacologic attenuation of the hyperdynamic response to supraceliac aortic clamping

Aortic occlusion is accompanied by a hyperdynamic cardiovascular response secondary to increased systemic vascular resistance and increased cardiac output. This study was designed primarily to determine the safety and cardiovascular response to hydrogen sulfide (H2S; HS) administration with supraceliac aortic cross-clamp and, secondarily, on short-duration resuscitation. A validated porcine model (five sham swine compared with five controls) demonstrated a significant hyperdynamic cardiovascular response to 35% blood volume hemorrhage, 50-minute suprarenal aortic cross-clamping, and 6-hour resuscitation. Eight additional experimental swine were administered HS at 4 mg/min during aortic cross-clamping. During the cross-clamp period, hemodynamic curves of mean arterial pressure and heart rate demonstrated a blunting effect with HS administration, with a significant decrease being seen with mean arterial pressure at the end of the cross-clamp period (120 vs 149 mm Hg; P = .04). Resuscitation requirements were significantly reduced at 6 hours because the HS cohort received 8 L less crystalloid (P = .001) and 10.4 mg less epinephrine (P < .001). There was not a significant change in cardiac output, systemic vascular resistance, pulmonary vascular resistance, or pathologic liver analysis. The administration of HS during the 50 minutes of supraceliac aortic cross-clamp significantly reduced stress of the left heart. On clamp release, HS significantly reduced the need for volume and pressors. HS has positive benefits during cross-clamp and subsequent resuscitation, demonstrating that targeted pharmacologic therapy is possible to minimize adverse physiologic changes with aortic occlusion.

Endovascular Treatment of Infrarenal Abdominal Aortic Aneurysm with Short and Angulated Neck in High-Risk Patient

Endovascular treatment of abdominal aortic aneurysms (AAA) is an established alternative to open repair. However lifelong surveillance is still required to monitor endograft function and signal the need for secondary interventions (Hobo and Buth 2006). Aortic morphology, especially related to the proximal neck, often complicates the procedure or increases the risk for late device-related complications (Hobo et al. 2007 and Chisci et al. 2009). The definition of a short and angulated neck is based on length (<15 mm), and angulation (>60°) (Hobo et al. 2007 and Chisci et al. 2009). A challenging neck also offers difficulties during open repairs (OR), necessitating extensive dissection with juxta- or suprarenal aortic cross-clamping. Patients with extensive aneurysmal disease typically have more comorbidities and may not tolerate extensive surgical trauma (Sarac et al. 2002). It is, therefore, unclear whether aneurysms with a challenging proximal neck should be offered EVAR or OR (Cox et al. 2006, Choke et al. 2006, Robbins et al. 2005, Sternbergh III et al. 2002, Dillavou et al. 2003, and Greenberg et al. 2003). In our case the insertion of a thoracic endograft followed by the placement of a bifurcated aortic endograft for the treatment of a very short and severely angulated neck proved to be feasible offering acceptable duration of aneurysm exclusion. This adds up to our armamentarium in the treatment of high-risk patients, and it should be considered in emergency cases when the fenestrated and branched endografts are not available.

Postoperative Renal Function After Juxtarenal Aortic Aneurysm Repair With Simple Cross-Clamping

We report our 11-year experience of juxtarenal aortic aneurysm (JAA) repair with suprarenal aortic cross-clamping. We retrospectively reviewed 51 consecutive JAA repairs performed between 2000 and 2010. In all 51 patients, aneurysms were replaced by prosthetic grafts with simple suprarenal aortic cross-clamping. No special renal protective measures (except inter-renal cross-clamping) were performed during interruption of perfusion to kidneys. For inter-renal cross-clamping, the aortic cross-clamp was placed from below one renal artery to above the other renal artery to maintain hemilateral renal perfusion. This technique was applied in 27 patients (54%). Postoperative complications, renal function, and survival were evaluated. There were no deaths. The average renal ischemia time was 28.9 ± 9.7 minutes. Postoperatively, transient renal failure (defined as an estimated glomerular filtration rate of <30 mL/min/1.73 m(2)) occurred in 14% of the patients. The postoperative decrease of estimated glomerular filtration rate compared with the preoperative value was significantly smaller in the inter-renal clamp group (7.4% ± 16%) than in the suprarenal clamp group (17.5% ± 16%) (P < 0.05, unpaired t test). However, renal dysfunction was temporary and recovered to baseline before discharge with conservative therapy in all patients except one. In addition, renal function was generally preserved at 1 year after surgery. Surgical repair of JAA can be performed with simple cross-clamping and an acceptable renal ischemic time, achieving excellent results. Inter-renal cross-clamping reduces renal damage compared with suprarenal cross-clamping.

Renal and abdominal visceral complications after open aortic surgery requiring supra-renal aortic cross clamping

PurposeThe aim of this study was to assess renal or abdominal visceral complications after open aortic surgery (OAS) requiring supra-renal aortic cross clamping (SRACC).MethodsWe retrospectively reviewed the medical records of 66 patients who underwent SRACC. Among them, 17 followed supra-celiac aortic cross clamping (SCACC) procedure, 42 supra-renal, and 7 inter-renal aorta. Postoperative renal, hepatic or pancreatic complications were investigated by reviewing levels of serum creatinine and hepatic and pancreatic enzymes. Preoperative clinical and operative variables were analyzed to determine risk factors for postoperative renal insufficiency (PORI).ResultsIndications for SRACC were 25 juxta-renal aortic occlusion and 41 aortic aneurysms (24 juxta-renal, 12 supra-renal and 5 type IV thoraco-abdominal). The mean duration of renal ischemic time (RIT) was 30.1 ± 22.2 minutes (range, 3 to 120 minutes). PORI developed in 21% of patients, including four patients requiring hemodialysis (HD). However, chronic HD was required for only one patient (1.5%) who had preoperative renal insufficiency. RIT ≥ 25 minutes and SCACC were significant risk factors for PORI development by univariate analysis, but not by multivariate analysis. Serum pancreatic and hepatic enzyme was elevated in 41% and 53% of the 17 patients who underwent SCACC, respectively.ConclusionThough postoperative renal or abdominal visceral complications developed often after SRACC, we found that most of those complications resolved spontaneously unless there was preexisting renal disease or the aortic clamping time was exceptionally long.