Guillermo A. Escobar

Endovascular aortic aneurysm repair with carbon dioxide-guided angiography in patients with renal insufficiency.

OBJECTIVE Renal dysfunction following endovascular abdominal aortic aneurysm repair (EVAR) remains a significant source of morbidity and mortality. We studied the use of carbon dioxide (CO(2)) as a non-nephrotoxic contrast agent for EVAR. METHODS Recorded data from 114 consecutive patients who underwent EVAR with CO(2) as the contrast agent over 44 months were retrospectively analyzed. CO(2) was used exclusively in 72 patients and in an additional 42 patients iodinated contrast (IC) was given (mean, 37 mL). Renal and hypogastric artery localization and completion angiography were done with CO(2) in all patients, including additional arterial embolization in 16 cases. Preoperative National Kidney Foundation glomerular filtration rate (GFR) classification was normal in 16 patients, mildly decreased in 52, moderate to severely decreased in 44, and two patients were on dialysis. RESULTS All graft deployments were successful with no surgical conversions. CO(2) angiography identified 20 endoleaks (two type 1, 16 type 2, and two type 4) and three unintentionally covered arteries. Additional use of IC in 42 patients did not modify the procedure in any case. When compared with a cohort of patients who underwent EVAR using exclusively IC, the operative time was shorter with CO(2) (177 vs 194 minutes; P = .01); fluoroscopy time was less (21 vs 28 minutes; P = .002), and volume of IC was lower (37 vs 106 mL; P < .001). Postoperatively, there were two deaths, two instances of renal failure requiring dialysis, and no complications related to CO(2) use. Among patients with moderate to severely decreased GFR, those undergoing EVAR with IC had a 12.7% greater decrease in GFR compared with the CO(2) EVAR group (P = .004). At 1, 6, and 12-month follow-up, computed tomography angiography showed well-positioned endografts with the expected patent renal and hypogastric arteries in all patients and no difference in endoleak detection compared with the IC EVAR group. During follow-up, eight transluminal interventions and one open conversion were required, and no aneurysm-related deaths occurred. CONCLUSIONS CO(2)-guided EVAR is technically feasible and safe; it eliminates or reduces the need for IC use, may expedite the procedure, and avoids deterioration in renal function in patients with pre-existing renal insufficiency. A prospective trial comparing CO(2) with IC during EVAR is warranted.

A Contemporary Comparison of Aortofemoral Bypass and Aortoiliac Stenting in the Treatment of Aortoiliac Occlusive Disease

BACKGROUND Although aortofemoral bypass (AFB) has historically been the treatment of choice for aortoiliac occlusive disease (AIOD), rates of AFB have declined, while utilization of aortoiliac angioplasty and stenting (AS) has increased dramatically. The objective of the current study was to determine the effect of these trends on treatment outcomes in a contemporary single-institution experience with AIOD. METHODS Between 1997 and 2007, 118 AFB and 174 AS procedures were performed in 161 men (55.1%) and 131 women at a single university teaching hospital. Patient outcomes were retrospectively reviewed and analyses were performed using chi-squared/Fishers exact test and ANOVA. Ankle-brachial index (ABI) interactions between procedure type and Trans-Atlantic Inter-Society Consensus (TASC) category were calculated using a General Linear Model. A reduced Cox model was used to determine the impact of patency, presenting symptoms, duplex surveillance, and procedure type on amputations and revisions. Kaplan-Meier estimates for survival, freedom from amputation, and freedom from revision were used to evaluate long-term outcomes. RESULTS There was no difference between AFB and AS groups with respect to 30-day mortality (0.8% and 1.1%, p=0.64), myocardial infarction (1.7% and 1.1%, p=0.53), cerebrovascular accident (0.0% and 1.1%, p=0.35), or renal failure requiring hemodialysis (3.4% and 1.2%, p=0.19). AFB was associated with increased surgical complication rates including the need for emergency surgery (6.8% and 1.7%, p=0.029), infection/sepsis (16.1% and 2.3%, p<0.001), transfusion (16.1% and 5.7%, p=0.004), and lymph leak (8.5% and 0.6%, p=0.001). The difference between preprocedural and postprocedural ABI was greater for AFB than AS (R, 0.39 and 0.18, p<0.001; L, 0.41 and 0.15, p<0.001). This difference was maintained when patients were stratified by TASC category. CONCLUSION There were no differences between the AFB and AS groups with respect to long-term rates of mortality, amputation, or revision procedures. AFB continues to be performed safely, despite the case numbers in this series correlating with a lower-volume hospital. Morbidities associated with major open surgery in this series were counterbalanced by greater improvements in ABI. Patients and practitioners should continue to entertain both procedure types as viable alternatives for the treatment of AIOD.

Gender differences in outcomes of endovascular treatment of infrainguinal peripheral artery disease

Objective: Our goal was to assess the outcomes of females compared to males treated with endovascular lower extremity interventions in order to determine optimal therapy based on gender. Methods: We performed a retrospective review evaluating the outcomes of primary transluminal angioplasty (PTA) and PTA + stenting (PTA + S) for peripheral arterial disease (PAD). Patency rates and limb salvage were the primary end points. Results: A total of 1017 lesions were analyzed in 537 patients (229 male and 308 female) between 2004 and 2009. There were no differences between genders in lesion characteristics. Women were more likely to have interventions for critical limb ischemia (CLI). In CLI patients with superficial femoral artery (SFA) and tibial lesions, women had better patency rates (P < .005). Conclusions: Women have better patency rates compared with men following treatment of some CLI lesions. Interestingly, women are treated more frequently for CLI when compared to men. For some lesion types in women, PTA alone was equivalent to PTA + S. Our results suggest that outcomes may be optimized by tailoring interventions to gender.

Primary Extracranial Vertebral Artery Aneurysms

BACKGROUND Extracranial vertebral artery aneurysms are uncommon and are usually associated with trauma or dissection. Primary cervical vertebral aneurysms are even rarer and are not well described. The presentation and natural history are unknown and operative management can be difficult. Accessing aneurysms at the skull base can be difficult and, because the frail arteries are often afflicted with connective tissue abnormalities, direct repair can be particularly challenging. We describe the presentation and surgical management of patients with primary extracranial vertebral artery aneurysms. METHODS In this study we performed a retrospective, multi-institutional review of patients with primary aneurysms within the extracranial vertebral artery. RESULTS Between January 2000 and January 2011, 7 patients, aged 12-56 years, were noted to have 9 primary extracranial vertebral artery aneurysms. All had underlying connective tissue or another hereditary disorder, including Ehler-Danlos syndrome (n=3), Marfans disease (n=2), neurofibromatosis (n=1), and an unspecified connective tissue abnormality (n=1). Eight of 9 aneurysms were managed operatively, including an attempted bypass that ultimately required vertebral ligation; the contralateral aneurysm on this patient has not been treated. Open interventions included vertebral bypass with vein, external carotid autograft, and vertebral transposition to the internal carotid artery. Special techniques were used for handling the anastomoses in patients with Ehler-Danlos syndrome. Although endovascular exclusion was not performed in isolation, 2 hybrid procedures were performed. There were no instances of perioperative stroke or death. CONCLUSIONS Primary extracranial vertebral artery aneurysms are rare and occur in patients with hereditary disorders. Operative intervention is warranted in symptomatic patients. Exclusion and reconstruction may be performed with open and hybrid techniques with low morbidity and mortality.

Rifampin Soaking Dacron-Based Endografts for Implantation in Infected Aortic Aneurysms—New Application of a Time-Tested Principle

Infections involving the aorta are associated with high rates of morbidity and mortality, and their management is complex. Saturating Dacron grafts in rifampin (60 mg/mL) inhibits the growth of organisms commonly found to be involved in both primary aortic infections and aortoenteric fistulas. Open repair and replacement of the aorta with rifampin-soaked Dacron grafts is frequently used in clinical practice and is considered a viable option for open repair with a low recurrence of infection; however, the morbidity and mortality of the procedure is significant. More recently, patients who are high risk for open surgery have been managed with endografts to treat infected aortas and aortoenteric fistulas with limited success, a high recurrence rate, and elevated mortality. We describe a technique to expose Dacron endografts with rifampin delivered via injection port or into the sheath before deployment in selected patients with aortic infections. We used this novel technique in 2 patients who were high risk for open repair: 1 with a bleeding aortoenteric fistula and 1 with mycotic abdominal aortic aneurysm. The first patient tolerated 1.5 years without surgical correction of the duodenal defect after placement of a rifampin-treated endograft. This allowed her to recover and ultimately undergo definitive repair under elective circumstances. Our second patient remains without evidence of recurrence 1 year after implantation for a mycotic abdominal aortic aneurysm. Following the principles of rifampin use in open vascular repairs, treating Dacron endografts with rifampin may add similar antimicrobial resistance when used to treat selected aortic infections.

Endovascular abdominal aortic aneurysm repair versus open repair: why and why not?

Randomized clinical trials have documented clinical equipoise when comparing endovascular abdominal aortic aneurysm repair (EVAR) with open aneurysm repair (OAR). Studies using large administrative databases in the United States have documented a trend whereby the majority of patients undergoing elective abdominal aortic aneurysm (AAA) repair in the United States are being repaired using endovascular techniques. However, few specific guidelines, outside of anatomic criteria for EVAR, exist to aid the physician in determining which approach is best for the individual patient. Variables to be considered in order to determine which approach is best for the patient who requires an AAA repair include age and comorbidities, arterial anatomy, and provider characteristics.

Contemporary outcomes with percutaneous vascular interventions for peripheral critical limb ischemia in those with and without poly-vascular disease.

Given the very ill nature of patients with critical limb ischemia (CLI), the use of percutaneous vascular interventions (PVIs) for limb salvage may or may not be efficacious; in particular, for those with polyvascular arterial disease. Herein, we reviewed large, multi-institutional outcomes of PVI in polyvascular and peripheral arterial disease (PAD) patients with CLI. An 18-hospital consortium collected prospective data on patients undergoing endovascular interventions for PAD with 6-month follow-up from January 2008 to December 2011. The patient cohort included 4459 patients with CLI; of those, 3141 patients had polyvascular (coronary artery disease, cerebrovascular disease and PAD) disease, whereas 1318 patients suffered from only PAD. All patients were elderly and with significant comorbidities. The mean ankle–brachial index (ABI) was 0.44 and was not different between those with and without polyvascular disease. Polyvascular patients had more femoropopliteal and infra-inguinal interventions and less aortoiliac interventions than PAD patients. Pre- and post-procedural cardioprotective medication use was less in the PAD patients as compared with polyvascular patients. Vascular complications requiring surgery were higher in PAD patients whereas other access complications were similar between groups. At 6-month follow-up, death was more common in the polyvascular group (6.7% vs 4.1%, p<0.001) as was repeat PVI, but no difference was found in the amputation rate. Considering the group as a whole at the 6-month follow-up, predictors of amputation/death included age (HR=1.01; 95% CI=1.002–1.02), anemia (HR=2.6; 95% CI=2.1–3.2), diabetes mellitus (HR=1.6; 95% CI=1.3–1.9), congestive heart failure (HR=1.6; 95% CI=1.4–1.9), and end-stage renal failure (HR=1.9; 95% CI=1.5–2.3), while female sex was protective (HR=0.7; 95% CI=0.6–0.8). In conclusion, from examination of this large, multicenter, multi-specialist practice registry, patients with polyvascular disease had higher 6-month mortality than PAD patients, but this was not a factor in 6-month limb amputation outcomes. This study also underscores that PAD patients still lag in cardioprotective medication use as compared with polyvascular patients.

Randomized trials in angioplasty and stenting of the renal artery: tabular review of the literature and critical analysis of their results.

As the incidence of hypertension (HTN) continues to rise, finding the optimal treatment of this multifactorial disease is critical. Renal artery stenosis (RAS) is a known etiology for HTN and is associated with declining renal function. Other than medications, the original gold standard for treatment of HTN from RAS was with an open surgical revascularization or nephrectomy. Since then, endovascular interventions for RAS have been reported to be technically possible, but their efficacy over medications or surgery has yielded conflicting results in case series and randomized trials. This tabular review summarizes the results of randomized trials that compared the outcomes of endovascular renal artery interventions with nonendovascular techniques (including medical and surgical treatments) for the treatment of HTN and renal dysfunction. Based on these data, the strengths and weaknesses of individual trials are critically analyzed to better define the methods to identify and treat patients with RAS.

APACHE III Score on ICU Admission Predicts Hospital Mortality After Open Thoracoabdominal and Open Abdominal Aortic Aneurysm Repair

BACKGROUND No prior studies, to our knowledge, have examined the performance of the Acute Physiology and Chronic Health Evaluation (APACHE) III score in predicting mortality of patients undergoing open thoracoabdominal aortic aneurysm (TAAA) or open abdominal aortic aneurysm (AAA) repair. We sought to evaluate APACHE III scores in the prediction of postoperative mortality in elective TAAA and AAA repairs. METHODS Over a 9-year period (July 1998 through June 2007), prospective data (demographics, admitting diagnosis, APACHE III score, intensive care unit [ICU] and hospital length of stay, ICU and hospital mortality) were collected by a dedicated APACHE III coordinator for all patients admitted to a tertiary academic surgical ICU (20 beds). Observational and comparative analyses were performed. Emergent repairs for ruptured aneurysms were excluded from the study. RESULTS Forty-one patients underwent open elective repair of TAAA and 404 underwent open elective repair of AAA. Mean age of the TAAA group was 63.4 ± 9.8 years and the AAA group was 70.3 ± 8.3 years. Mean APACHE III score was 54 (range: 10-103) for the TAAA group and 45 (range: 11-103) for the AAA group. The in-hospital mortality rate for TAAA patients was 4.9% (n = 2) and for AAA patients was 2.0% (n = 8). Mean APACHE III scores on ICU admission were significantly greater in nonsurvivors versus survivors (79 vs. 45, p < 0.0001). For the entire patient cohort, the APACHE III score on ICU admission was an excellent discriminator of hospital mortality (receiver operating characteristic and area under the curve 0.92 [standard error of 0.05, 95% CI: 0.83-1.0]). CONCLUSIONS APACHE III is an accurate predictor of survival to hospital discharge in both open elective TAAA and AAA repairs.

Delayed management of Grade III blunt aortic injury: Series from a Level I trauma center.

BACKGROUND Blunt aortic injuries (BAIs) are traditionally treated as surgical emergencies, with the majority of repairs performed in an urgent fashion within 24 hours, irrespective of the grade of aortic injury. These patients are often underresuscitated and often have multiple other trauma issues that need to be addressed. This study reviews a single centers experience comparing urgent (<24 hours) thoracic endovascular aneurysm repair (TEVAR) versus delayed (>24 hours) TEVAR for Grade III BAI. METHODS All patients undergoing TEVAR for BAI at a single institution between March 2004 and March 2014 were reviewed (n = 43). Patients with Grade I, II, or IV aortic injuries as well as those who were repaired with an open procedure or who lacked preoperative imaging were excluded from the analysis. Demographics, intraoperative data, postoperative survival, and complications were compared. RESULTS During this period, there were 43 patients with blunt thoracic aortic injury. There were 29 patients with Grade III or higher aortic injuries. Of these 29 patients, 1 declined surgery, 2 were repaired with an open procedure, 10 underwent urgent TEVAR, and 16 had initial observation. Of these 16, 13 underwent TEVAR in a delayed fashion (median, 9 days; range, 2–91 days), and 3 died of non–aortic-related pathology. Comparing the immediate repair group versus the delayed repair group, there were no significant demographic differences. Trauma classification scores were similar, although patients in the delayed group had a higher number of nonaortic injuries. The 30-day survival was similar between the two groups (9 of 10 vs. 12 of 16), with no mortalities caused by aortic pathology in either group. CONCLUSION Watchful waiting may be permissible in patients with Grade III BAI with other associated multisystem trauma. This allows for a repair in a more controlled environment. LEVEL OF EVIDENCE Therapeutic study, level V.