Timur P. Sarac

The management of severe aortoiliac occlusive disease: Endovascular therapy rivals open reconstruction

OBJECTIVE Aortobifemoral bypass (ABF) grafting has been the traditional treatment for extensive aortoiliac occlusive disease (AIOD). This retrospective study compared the outcomes and durability of recanalization, percutaneous transluminal angioplasty, and stenting (R/PTAS) vs ABF for severe AIOD. METHODS Between 1998 and 2004, 86 patients (161 limbs) underwent ABF (n = 75) or iliofemoral bypass (n = 11), and 83 patients (127 limbs) underwent R/PTAS. All patients had severe symptomatic AIOD (claudication, 53%; rest pain, 28%; tissue loss, 12%; acute limb ischemia, 7%). The analyses excluded patients treated for aneurysms, extra-anatomic procedures, and endovascular treatment of iliac stenoses. Original angiographic imaging, medical records, and noninvasive testing were reviewed. Kaplan-Meier estimates for patency and survival were calculated and univariate analyses performed. Mortality was verified by the Social Security database. RESULTS The ABF patients were younger than the R/PTAS patients (60 vs 65 years; P = .003) and had higher rates of hyperlipidemia (P = .009) and smoking (P < .001). All other clinical variables, including cardiac status, diabetes, symptoms at presentation, TransAtlantic Inter-Society Consensus stratification, and presence of poor outflow were similar between the two groups. Patients underwent ABF with general anesthesia (96%), often with concomitant treatment of femoral or infrainguinal disease (61% endarterectomy, profundaplasty, or distal bypass). Technical success was universal, with marked improvement in ankle-brachial indices (0.48 to 0.84, P < .001). Patients underwent R/PTAS with local anesthesia/sedation (78%), with a 96% technical success rate and similar hemodynamic improvement (0.36 to 0.82, P < .001). At the time of R/PTAS, 21% of patients underwent femoral endarterectomy/profundaplasty or bypass (n = 5) for concomitant infrainguinal disease. Limb-based primary patency at 3 years was significantly higher for ABF than for R/PTAS (93% vs 74%, P = .002). Secondary patency rates (97% vs 95%), limb salvage (98% vs. 98%), and long-term survival (80% vs 80%) were similar. Diabetes mellitus and the requirement of distal bypass were associated with decreased patency (P < .001). Critical limb ischemia at presentation (tissue loss, hazard ratio [HR], 8.1; P < .001), poor outflow (HR, 2; P = .023), and renal failure (HR, 2.5; P = .02) were associated with decreased survival. CONCLUSION R/PTAS is a suitable, less invasive alternative to ABF for the treatment of severe AIOD. Repair of the concomitant femoral occlusive disease is often needed regardless of open or endovascular treatment. Infrainguinal disease negatively affects the durability of the procedure and patient survival.

Warfarin improves the outcome of infrainguinal vein bypass grafting at high risk for failure

OBJECTIVE Patients with marginal venous conduit, poor arterial runoff, and prior failed bypass grafts are at high risk for infrainguinal graft occlusion and limb loss. We sought to evaluate the effects of anticoagulation therapy after autogenous vein infrainguinal revascularization on duration of patency, limb salvage rates, and complication rates in this subset of patients. METHODS This randomized prospective trial was performed in a university tertiary care hospital and in a Veterans Affairs Hospital. Fifty-six patients who were at high risk for graft failure were randomized to receive aspirin (24 patients, 27 bypass grafts) or aspirin and warfarin (WAR; 32 patients, 37 bypass grafts). All patients received 325 mg of aspirin each day, and the patients who were randomized to warfarin underwent anticoagulation therapy with heparin immediately after surgery and then were started on warfarin therapy to maintain an international normalized ratio between 2 and 3. Perioperative blood transfusions and complications were compared with the Student t test or with the chi2 test. Graft patency rates, limb salvage rates, and survival rates were compared with the Kaplan-Meier method and the log-rank test. RESULTS Sixty-one of the 64 bypass grafts were performed for rest pain or tissue loss, and 3 were performed for short-distance claudication. There were no differences between the groups in ages, indications, bypass graft types, risk classifications (ie, conduit, runoff, or graft failure), or comorbid conditions (except diabetes mellitus). The cumulative 5-year survival rate was similar between the groups. The incidence rate of postoperative hematoma (32% vs 3.7%; P = .004) was greater in the WAR group, but no differences were seen between the WAR group and the aspirin group in the number of packed red blood cells transfused, in the incidence rate of overall nonhemorrhagic wound complications, or in the overall complication rate (62% vs 52%). The immediate postoperative primary graft patency rates (97.3% vs 85.2%) and limb salvage rates (100% vs 88.9%) were higher in the WAR group as compared with the aspirin group. Furthermore, the cumulative 3-year primary, primary assisted, and secondary patency rates were significantly greater in the WAR group versus the aspirin group (74% vs 51%, P = .04; 77% vs 56%, P = .05; 81% vs 56%, P = .02) and cumulative limb salvage rates were higher in the WAR group (81% vs 31%, P = .01). CONCLUSIONS Perioperative anticoagulation therapy with heparin increases the incidence rate of wound hematomas, but long-term anticoagulation therapy with warfarin improves the patency rate of autogenous vein infrainguinal bypass grafts and the limb salvage rate for patients at high risk for graft failure.

A comparison of endovascular revascularization with traditional therapy for the treatment of acute mesenteric ischemia

OBJECTIVES Few centers have adopted endovascular therapy for the treatment of acute mesenteric ischemia (AMI). We sought to evaluate the effect of endovascular therapy on outcomes for the treatment of AMI. METHODS A single-center, retrospective cohort review was performed on all consecutive patients with thrombotic or embolic AMI presenting between 1999 and 2008. Patients with mesenteric venous thrombosis, nonocclusive mesenteric ischemia, and ischemia associated with aortic dissection were excluded. Demographic factors, preoperative metabolic status, and etiology were compared. Primary clinical outcomes included endovascular technical success, operative complications, and in-hospital mortality. RESULTS Seventy consecutive patients were identified with AMI (mean age, 64 ± 13 years). Etiology of mesenteric ischemia was 65% thrombotic and 35% embolic occlusions. Endovascular revascularization was the preferred treatment (81%) vs operative therapy (19%). Successful endovascular treatment was achieved in 87%. Endovascular therapy required laparotomy in 69% vs traditional therapy in 100% (P < .05), with a median 52-cm necrotic bowel resected (interquartile range [IQR], 11-140 cm) vs 160 cm (IQR, 90-250 cm; P < .05), respectively. Acute renal failure and pulmonary failure occurred less frequently with endovascular therapy (27% vs 50%; P < .05 and 27% vs 64%; P < .05). Successful endovascular treatment resulted in a mortality rate of 36% compared with 50% (P < .05) with traditional therapy, whereas the mortality rate for endovascular failures was 50%. Endovascular therapy was associated with improved mortality in thrombotic AMI (odds ratio, 0.10; 95% confidence interval, 0.10-0.76; P < .05). CONCLUSIONS Endovascular therapy has altered the management of AMI, and there are measurable advantages to this approach. Using endovascular therapy as the primary modality for AMI reduces complications and improves outcomes.

Endovascular treatment of stenotic and occluded visceral arteries for chronic mesenteric ischemia

PURPOSE Percutaneous angioplasty and stenting (PTAS) is emerging as a therapeutic option for patients with chronic mesenteric ischemia. This study evaluated patency and mortality, and their relationship between degree of vessel occlusion (stenotic or totally occluded), stent characteristics, and comorbidities in patients who were treated with PTAS of the visceral vessels for chronic mesenteric ischemia. METHODS A retrospective review was performed of the records of all patients who underwent PTAS of the celiac, superior mesenteric, or inferior mesenteric arteries, or both, for symptomatic chronic mesenteric ischemia between January 2001 and December 2005. Patient demographics, lesion characteristics (stenosis or occlusion), interventional details, and early and late mortality rates were recorded. Cumulative mortality and patency rates and factors associated with outcomes were determined using Kaplan-Meier method and Cox proportional hazards modeling. RESULTS Eighty-seven mesenteric vessels (57 superior mesenteric, 23 celiac, and 7 inferior mesenteric arteries) were treated in 65 patients (29 men and 36 women). Completely occluded vessels were treated in 18 patients (28%), and >60% stenosis was treated in 47 patients (72%). Mesenteric angina was the most common symptom (97%). For the entire series, the cumulative 1-year results were primary patency, 65% (95% confidence interval [CI], 50%-80%); primary assisted patency, 97% (95% CI, 92%-100%); secondary patency, 99% (95% CI, 96%-100%); and survival, 89% (95% CI, 80%-98%). All deaths occurred <or=60 days after treatment. The endovascular treatment of visceral artery occlusion was not associated with diminished patency or survival, irrespective of stent size or number. Patients requiring bowel resection were less likely to survive than those who did not (odds ratio [OR], 26; 95% CI, 3.5-192; P < .001). One-year primary patency was worse among patients with chronic obstructive pulmonary disease (OR, 3.2; 95% CI, 1.4-7.7; P = .009) or who had femoral access (OR, 3.0; 95% CI, 1.1-7.9; P = .015). CONCLUSIONS For patients with chronic mesenteric ischemia, the results of endovascular treatment of occluded mesenteric arteries are indistinguishable from those treated for stenotic vessels. Patients requiring bowel resection are less likely to survive, and those with chronic obstructive pulmonary disease or who had femoral access have higher reintervention rates.

Disparate outcome after endovascular treatment of small versus large abdominal aortic aneurysm

OBJECTIVES The size of an abdominal aortic aneurysm is the most important parameter for determining whether repair is appropriate. This decision, however, must be considered in the context of long-term outcome of treatment, balancing risk for rupture with mortality from the initial procedure and all subsequent secondary procedures necessary when durability is not ideal. Information on the results of endovascular repair of small versus large aneurysms has not been available. METHODS Preoperative imaging studies and postoperative outcome were assessed in 700 patients who underwent endovascular repair of abdominal aortic aneurysm over 6 years at a single institution. Patients were divided into two groups: 416 patients (59.4%) with aneurysms smaller than 5.5 cm in diameter and 284 patients (40.6%) with aneurysms 5.5 cm or larger in diameter. Outcome variables were assessed with the Kaplan-Meier method and the log-rank test. RESULTS Patients with small and large aneurysms were comparable with regard to all baseline parameters assessed, with the single exception of a small increase in age (2.3 years) in patients with large aneurysms (P =.031). While there were no differences in rate of type II endoleaks, mid-term changes in sac diameter, or aneurysm rupture between the two groups, at 24 months patients with large aneurysms had more type I leaks (6.4% +/- 2.3% vs 1.4% +/- 0.6%; P =.011), device migration (13% +/- 4.0% vs 4.4% +/- 1.8%; P =.006), and conversion to open surgical repair (8.2% +/- 3.2% vs 1.4% +/- 1.1%; P =.031). Of greatest importance, at 24 months patient survival was diminished (71% +/- 4.6% vs 86% +/- 2.8%; P <.001) and risk for aneurysm-related death was increased (6.1% +/- 2.6% vs 1.5% +/- 1.0%; P =.011) in the group with large aneurysms. CONCLUSIONS Outcome after endovascular repair of abdominal aortic aneurysm depends on size; results appear inferior in patients with larger aneurysms. These differences attain importance when choosing between observation and repair, balancing risk for rupture against size-dependent outcome.

Long-term follow-up of type II endoleak embolization reveals the need for close surveillance

OBJECTIVE Aneurysm growth after endovascular aneurysm repair (EVAR) in patients with type II endoleak is associated with adverse outcomes. This study evaluated the long-term success of embolization of type II endoleaks in preventing aneurysm sac growth. METHODS We retrospectively reviewed outcomes of patients who underwent infrarenal EVAR who were treated for a type II endoleak between 2000 and 2008. Computed tomography scans were evaluated for aneurysm sac growth or shrinkage from the time of treatment of the endoleak. The embolization material used, graft type, target vessel embolized, and comorbidities were evaluated for their association with sac growth or shrinkage. RESULTS Ninety-five patients underwent 140 embolization procedures. The mean time from EVAR to embolization was 26.1 ± 22.2 months, and the average increase in size of the aneurysm sac from EVAR to treatment was 0.7 × 0.5 cm. Patients underwent an average of 1.6 ± 0.8 embolization procedures after EVAR. Thirteen patients underwent initial simultaneous embolization of two targets. Embolization was with glue (61%), coils (29%), glue and coils (7%), and Gelfoam (3%; Pfizer Inc, New York, NY). No abdominal aortic aneurysms (AAA) ruptured. Eight patients (8.4%) underwent graft explant and open repair; 19 (20%) required two or more embolization procedures. There was no difference in the target vessel treated or the treatment used in halting sac expansion (>5 mm). Coil embolization alone resulted in more second procedures. The 5-year cumulative survival was 65% (95% confidence interval [CI], 52%-77%), freedom from explant was 89% (95% CI, 81%-97%), freedom from second embolization was 76% (95% CI, 66%-86%), and freedom from sac expansion >5 mm was 44% (95% CI 30%-50%). Univariable analysis identified continued tobacco use (hazard ratio [HR], 2.30; 95% CI, 1.02-5.13; P = .04) was associated with continued sac expansion, and hyperlipidemia (HR, 9.64; 95% CI, 2.22-41.86) was associated with patients requiring a second embolization procedure. CONCLUSIONS Embolization of type II endoleaks is successful early in preventing aneurysm sac growth and rupture after EVAR. However, a significant number of patients require more than one procedure, and at 5 years, many patients who underwent embolization of a type II endoleak continued to experience sac growth. Patients with hyperlipidemia who undergo coil embolization are more likely to require a second embolization procedure, and patients who smoke have a higher likelihood of AAA sac expansion after embolization. Continued long-term surveillance is necessary in this cohort of patients.

Endovascular aneurysm repair: gender-specific results

OBJECTIVES The outcome for a wide variety of diseases and treatment methods varies by gender. In an effort to determine whether gender has a role in the outcome of endovascular aortic aneurysm repair, we analyzed data from consecutive patients treated at a single institution over 6 years. METHODS Over 6 years ending in March 2002, 704 patients underwent endovascular repair of an infrarenal abdominal aortic aneurysm at The Cleveland Clinic. Six hundred six patients (86.1%) were men and 98 patients (13.9%) were women. Preprocedure and postprocedure imaging studies were evaluated to determine the frequency of aneurysm sac shrinkage or growth, defined as diameter change equal to or greater than 5 mm. Presence and type of endoleak was assessed with non-contrast material-enhanced, post-contrast-enhanced, and delayed post-contrast-enhanced computed tomography scans. These and other clinical variables were assessed with the Kaplan-Meier method and the Cox-Mantel log-rank test, and values were expressed as mean +/- SE. RESULTS Male and female patients were comparable with respect to baseline comorbid conditions. Women, however, were slightly older (76.7 +/- 0.7 years vs 74.4 +/- 0.3 years; P =.009), and had slightly smaller aneurysms (5.2 +/- 0.1 cm vs 5.4 +/- 0.04 cm; P =.033). There were no gender-specific differences in perioperative mortality (men, 1.3%; women, 3.1%; P =.197) or mid-term (24 months) survival (men, 80% +/- 2.6%; women, 78% +/- 8.1%). Similarly, there were no differences at 24 months in risk for graft migration (7.5% +/- 2.0% vs 5.4% +/- 3.2%), need for secondary remedial procedures (24% +/- 2.9% vs 21% +/- 6.3%), conversion to open surgery (3.9% +/- 1.5% vs 3.8% +/-2.7%), or post-repair aneurysm rupture (1.1% +/- 0.9% vs 2.2% +/-2.2%) in male and female patients, respectively. In contrast, risk for graft limb occlusion at 24 months was significantly higher in women than in men (11% +/- 5.2% vs 3.3% +/- 1.1%; P =.022). While frequency of endoleak of any type did not differ among male and female patients, aneurysm sac shrinkage at 24 months was more rapid in women (76% +/- 8.1% vs 57% +/- 3.5%; P =.019). CONCLUSIONS With the exception of slightly older age and somewhat smaller aneurysm, female patients are similar to male patients undergoing endovascular aneurysm repair. A greater frequency of graft limb occlusion was observed in female patients, but no statistically significant differences were detected in survival, rupture risk, or need for secondary procedures. Moreover, a more rapid rate of aneurysm sac shrinkage was detected in women. These observations suggest that endovascular aneurysm repair should be offered to suitable candidates irrespective of gender.

The contemporary management of splenic artery aneurysms

OBJECTIVES The management of patients with splenic artery aneurysms (SAAs) is variable since the natural history of these aneurysms is poorly delineated. The objective of this study was to review our experience with open repair, endovascular therapy, and observation of SAAs over a 14-year interval. METHODS Between January 1, 1996 and December 31, 2009, 128 patients with SAAs were evaluated. Sixty-two patients underwent surgical repair (n = 13) or endovascular coil/glue ablation (n = 49), while 66 patients underwent serial observation. The original medical records and computed tomography (CT) imaging were reviewed. Statistical analyses were performed using χ(2) or Fishers exact test for categorical patient characteristics and t-test for continuous variables. Kaplan-Meier estimates for survival were calculated. Mortality was verified via the Social Security Death Index. RESULTS Patients (61 ± 11 years, 69% female) were investigated for abdominal symptoms (49%) or had the incidental finding of SAA (mean size, 2.4 ± 1.4 cm). Seven patients (5.5%) presented with rupture and were treated emergently with two perioperative mortalities (29%). Patients requiring surgical or endovascular treatment were more likely male (40% vs 21%, P = .031), younger (58 vs 64 years; P = .004), and current smokers (18% vs 5%; P = .035). Increased aneurysm calcification was associated with decreased SAA size (P = .013). The mean aneurysm size at initial diagnosis was 1.67 cm for patients undergoing observation and 3.13 cm for the treated group (P < .001). Endovascular repair was safe and durable with a mean 1.5-mm regression in SAA size over 2 years. The mean rate of growth for observed SAA was 0.2 mm/y. Ten-year survival was 89.4% (95% confidence interval: 82.0, 97.4) for all patients (observed group, 94.9%; treated group, 85.1%; P = .18). No late aneurysm-related mortality was identified. CONCLUSIONS Ruptured SAAs are lethal. Large SAAs can undergo endovascular ablation safely with durable SAA regression. Smaller SAAs (<2 cm) grow slowly and carry a negligible rupture risk.

Stent-Graft Migration: A Reappraisal of Analysis Methods and Proposed Revised Definition

Purpose: To demonstrate the need for a radiographic definition of migration that accurately describes a specific failure mode of an aortic stent-graft. Methods: The diagnosis of endograft migration, as defined by the Society for Vascular Surgery/American Association for Vascular Surgery (SVS/AAVS) standards, requires a synthesis of clinical and/or radiographic observations. Radiographic studies and clinical reports of 704 consecutive patients treated over a 6-year period with abdominal aortic endografts were retrospectively reviewed. According to the current SVS/AAVS standards, 25 patients were identified as having endograft migration. Follow-up computed tomographic scans and radiographs available for 24 of these patients were scrutinized from discharge to the time of any observed proximal or distal fixation system movement based upon the discharge or 30-day CT scan. Proximal migration was defined with respect to the origin of the superior mesenteric artery (SMA) as movement in a caudal or cranial direction of ≥10 mm or >2 times the reconstructed resolution of the imaging study (whichever measurement was less). Distal migration was similarly defined using the aortic bifurcation and respective hypogastric artery origin as reference points. In an effort to assess the scan-to-scan variation, the distance between the SMA and lowest renal artery, which was expected to remain consistent, was measured. Results: Film analysis with application of the revised migration definition confirmed fixation system failure with respect to the native arterial system in 12 (50%) of the 24 patients. Subjects judged to have endograft migration according to the reporting standards but not to have radiographic evidence of migration based on the modified criteria included 2 proximal endoleaks without evidence of device movement treated with proximal extensions, 1 procedure-related migration, 2 type III endoleaks treated with a second prosthesis implanted within the first, 1 distal endoleak treated with a limb extension, 1 rupture with presumed distal limb migration, and 2 cases of component separation. Three limb extensions were placed in the absence of leak or migration. These 12 patients all had radiographic evidence that the proximal and distal aspects of the originally implanted device did not move with respect to the native arterial vasculature, thus confirming stability of the respective fixation system. Conclusions: Adherence to this comprehensive definition of device migration, which differs from the published reporting standards, allows differentiation of the specific mechanisms of device failure. Data viewed in this context will aid in the understanding of device strengths and weaknesses, potentially improve patient assessment, and encourage design modifications to address specific aspects relating to fixation failure.

Endovascular therapy for acute limb ischemia

BACKGROUND Acute limb ischemia (ALI) of the lower extremities remains a challenging clinical dilemma. Treatment of ALI has shifted toward endovascular therapies. The purpose of this study was to assess outcomes in patients treated for ALI with intra-arterial thrombolysis and/or adjuvant endovascular techniques. METHODS Consecutive patients with ALI of the lower extremities treated via endovascular intra-arterial methods between January 1, 2005 and September 30, 2007 were identified and reviewed. Comparisons of success, thrombolysis days, and all 30-day outcomes except mortality were performed using generalized estimating equations with logistic and proportional odds regression. Thirty-day mortality was assessed using logistic regression. Long-term patency, limb salvage, and survival were assessed using time-to-event methods, including Kaplan-Meier estimation and Cox proportional hazards models. RESULTS The analyzed dataset included 129 limbs treated in 119 patients presenting with ALI (class I 68%, class IIa 23%, class IIb 9%). The mean follow-up was 16.8 months (range: 0-43 months). Technical success was achieved in 82% cases. The 30-day mortality rate was 6.0% with all 30-day deaths occurring in females (P = .002). One (0.76%) central nervous system hemorrhage (CNS) was noted in this cohort. Primary patency for the entire cohort at 12 and 24 months was 50.1% (95% confidence interval [CI], 39.5-60.7) and 37.7% (95% CI, 26.2-49.1), respectively, while secondary patency was 74.0% (95% CI, 64.9-83.1) and 65.3% (95% CI, 54.5-76.2). Multivariable analyses identified patients presenting with femoropopliteal (hazard ratio [HR] 2.63) or tibial thrombosis (HR 2.80); graft thrombosis (vs native artery thrombosis, HR 2.57) and long-term dialysis (HR 3.66, 95% CI, 2.35-5.71, P < .001) were associated with poorer primary patency rates. Cumulative limb salvage at 24 months was 68.8% (95% CI: 59.5-78.1) with female gender (HR 3.34, P = .002) and thrombolysis ≥ 3 days (HR 2.35, P = .019) associated with an increased risk of limb loss. Overall 36-month survival was 84.5% (95% CI: 77.5-91.6). Women had decreased survival rates both in the short- and midterm (HR 6.29; 95% CI, 1.78-22.28; P = .004). CONCLUSIONS Endovascular therapy with thrombolysis remains an effective treatment option for patients presenting with lower extremity ALI. Thrombolysis should be limited to <3 days. Female gender negatively affects the rates of limb salvage and survival.