Luke K. Marone

Duplex ultrasound as the sole long-term surveillance method post-endovascular aneurysm repair: A safe alternative for stable aneurysms

OBJECTIVE Long-term surveillance with computed tomography (CT) after endovascular aneurysm repair (EVAR) increases both cost and risk. The purpose of this study was to evaluate the safety of an alternative follow-up modality with color flow duplex ultrasound scanning (CDU) as the sole method of imaging. METHODS In 2003, we initiated a new follow-up (FU) schedule with yearly CDU as the sole imaging method for selected patients. Indications included a residual sac of less than 4 cm, expanded later to stable sac size for more than 2 years. A stable type II endoleak was not a contraindication. CT scans were obtained selectively-based on suspicious findings of a new endoleak or enlarging sac on CDU. The records of all patients with at least 1 year FU under this schedule were reviewed. RESULTS One hundred eighty-four patients were followed with CDU only for 1 to 4 years for a mean of 24 +/- 13 months. The new schedule was initiated at a mean of 34 +/- 24 months after EVAR (range 1-112 months). Twenty-three patients had previous endoleaks that had resolved spontaneously or had been treated. During CDU FU, three new endoleaks were detected, one with sac enlargement. All prompted CT evaluation: one type II endoleak with stable sac size could not be identified on CT 3 months later, and two distal type I endoleaks that required limb extension. All three had a prior Ancure endograft. No ruptures or graft occlusions were noted. One abdominal aortic aneurysm (AAA) related death followed graft explantation for infection. There were two additional deaths from malignancy and two from cardiac causes. After the FU switch, freedom from endoleaks was 96%, and from secondary interventions 95% at 48 months by life table method. Mean AAA diameter at baseline was 54 +/- 8 mm and decreased to 40 +/- 11 mm before the switch to CDU only FU. At last FU mean aneurysm diameter was 39 +/- 11 mm. When the current switch criteria were applied to a consecutive series of 200 EVAR patients, 97% would have been eligible for CDU only surveillance by 3 years postoperatively. CONCLUSIONS CDU only surveillance post-EVAR is safe and can be initiated early after treatment in patients with shrinking or stable aneurysms. This policy should result in cost savings advantage and avoid the complications associated with CT.

Predictors of failure and success of tibial interventions for critical limb ischemia

OBJECTIVE The efficacy of tibial artery endovascular intervention (TAEI) for critical limb ischemia (CLI) and particularly for wound healing is not fully defined. The purpose of this study is to determine predictors of failure and success for TAEI in the setting of CLI. METHODS All TAEI for tissue loss or rest pain (Rutherford classes 4, 5, and 6) from 2004 to 2008 were retrospectively reviewed. Clinical outcomes and patency rates were analyzed by multivariable Cox proportional hazards regression and life table analysis. RESULTS One hundred twenty-three limbs in 111 patients (62% male, mean age 74) were treated. Sixty-seven percent of patients were diabetics, 55% had renal insufficiency, and 21% required hemodialysis. One hundred two limbs (83%) exhibited tissue loss; all others had ischemic rest pain. All patients underwent tibial angioplasty (PTA). Tibial excimer laser atherectomy was performed in 14% of the patients. Interventions were performed on multiple tibial vessels in 20% of limbs. Isolated tibial procedures were performed on 50 limbs (41%), while 73 patients had concurrent ipsilateral superficial femoral artery or popliteal interventions. The mean distal popliteal and tibial runoff score improved from 11.8 ± 3.6 to 6.7 ± 1.6 (P < .001), and the mean ankle-brachial index increased from 0.61 ± 0.26 to 0.85 ± 0.22 (P < .001). Surgical bypass was required in seven patients (6%). The mean follow up was 6.8 ± 6.6 months, while the 1-year primary, primary-assisted, and secondary patency rates were 33%, 50%, and 56% respectively. Limb salvage rate at 1 year was 75%. Factors found to be associated with impaired limb salvage included renal insufficiency (hazard ratio [HR] = 5.7; P = .03) and the need for pedal intervention (HR = 13.75; P = .04). TAEI in an isolated peroneal artery (odds ratio = 7.80; P = .01) was associated with impaired wound healing, whereas multilevel intervention (HR = 2.1; P = .009) and tibial laser atherectomy (HR = 3.1; P = .01) were predictors of wound healing. In patients with tissue loss, 41% achieved complete closure (mean time to healing, 10.7 ± 7.4 months), and 39% exhibited partial wound healing (mean follow up, 4.4 ± 4.8 months) at last follow up. Diabetes, smoking, statin therapy, and revascularization of > 1 tibial vessel had no impact on limb salvage or wound healing. Re-intervention rate was 50% at 1 year. CONCLUSIONS TAEI is an effective treatment for CLI with acceptable limb salvage and wound healing rates, but requires a high rate of reintervention. Patients with renal failure, pedal disease, or isolated peroneal runoff have poor outcomes with TAEI and should be considered for surgical bypass.

Endovascular interventions for TASC II D femoropopliteal lesions

BACKGROUND Advances in endovascular techniques have provided new options in the treatment of complex infrainguinal occlusive lesions. The purpose of this study was to evaluate outcomes of endovascular interventions on TransAtlantic InterSociety (TASC) II D femoropopliteal occlusive disease. METHODS All patients undergoing endovascular interventions for femoropopliteal occlusive disease between July 2004 and July 2009 were reviewed. Patient demographics, pre- and postprocedure ankle-brachial indices (ABI) and anatomic factors were analyzed. Outcomes evaluated included primary patency, assisted-patency, secondary patency, predictors of restenosis, and wound healing. RESULTS Five hundred eighty-five limbs were treated during the period reviewed. The study group included 79 TASC D limbs in 74 patients (mean age 76.5 +/- 11.9 years, male sex: 53%). Fifty-six limbs (71%) underwent treatment for critical limb ischemia, including 42 (53%) with tissue loss. Eleven patients (15%) had previous failed bypasses. Preoperative ABIs were unobtainable for 23 patients, while the remaining 56 had a mean baseline ABI of 0.54 +/- 0.28. There was one periprocedural mortality. Five patients (6.3%) had periprocedural complications. Mean increase in ABI postprocedure was 0.49 +/- 0.35. Follow-up was available for 74 limbs at a mean of 10.7 months (range, 1-35). There were 18 mortalities (24.3%) during the follow-up period. No patient required a major amputation during this follow-up period. Twenty-one limbs (26.6%) experienced restenosis and nine limbs (11.4%) experienced occlusion. Twenty-nine limbs underwent reintervention during the follow-up time, including nine which underwent multiple reinterventions. Primary, assisted-primary, and secondary patency rates at 12 and 24 months were 52.2%, 88.4%, 92.6% and 27.5%, 74.2%, and 88.9%, respectively. Predictors of restenosis/occlusion included hypercholesterolemia, the presence of a popliteal artery stent, and patients who were current or former smokers. CONCLUSIONS Endovascular interventions for TASC II D lesions can be safely performed with excellent hemodynamic improvement and limb salvage rates. Restenosis is not uncommon in this population, which mandates strict follow-up. Further follow-up is necessary to determine the long-term efficacy of these interventions.

Duplex criteria for determination of in-stent stenosis after angioplasty and stenting of the superficial femoral artery

OBJECTIVE Endovascular intervention is considered first-line therapy for most superficial femoral artery (SFA) occlusive disease. Duplex ultrasound (DU) criteria for SFA in-stent stenosis and correlation with angiographic data remain poorly defined. This study evaluated SFA-specific DU criteria for the assessment of SFA in-stent stenosis. METHODS From May 2003 to May 2008, 330 limbs underwent SFA angioplasty and stenting and were monitored by serial DU imaging. Suspected stenotic lesions underwent angiography and intervention when appropriate. Data pairs of DU and angiographically estimated stenosis <or=30 days of each other were analyzed. Seventy-eight limbs met these criteria, and 59 underwent reintervention. In-stent peak systolic velocity (PSV), the ratio of the stented SFA velocity/proximal SFA velocity, changes in ankle-brachial indices (ABIs), and the percentage of angiographic stenosis were examined. Linear regression and receiver operator characteristic (ROC) curve analyses were used to compare angiographic stenosis with PSV and velocity ratios (Vrs) to establish optimal criteria for determining significant in-stent stenosis. RESULTS Mean follow-up was 16.9 +/- 8.3 months. Of the 59 limbs that underwent reintervention, 37 (63%) were symptomatic, and 22 (37%) underwent reintervention based on DU findings alone. Linear regression models of PSV and Vr vs degree of angiographic stenosis showed strong adjusted correlation coefficients (R(2) = 0.60, P < .001 and R(2) = 0.55, P < 0.001, respectively). ROC curve analysis showed that to detect a >or=50% in-stent stenosis, a PSV >or=190 had 88% sensitivity, 95% specificity, a 98% positive predictive value (PPV), and a 72% negative predictive value (NPV); for Vr, a ratio of >1.50 had 93% sensitivity, 89% specificity, a 96% PPV, and a 81% NPV. To detect >or=80% in-stent stenosis, a PSV >or=275 had 97% sensitivity, 68% specificity, a 67% PPV, and a 97% NPV; a Vr ratio >or=3.50 had 74% sensitivity, 94% specificity, a 77% PPV, and a 88% NPV. Combining a PSV >or=275 and a Vr >or=3.50 to determine >or=80% in-stent stenosis had 74% sensitivity, 94% specificity, a 88% PPV, and a 85% NPV; odds ratio was 42.17 (95% confidence interval, 10.20-174.36, P < .001) to predict >or=80% in-stent stenosis. A significant drop in ABI (>0.15) correlated with a >62% in-stent stenosis, although the adjusted correlation coefficients was low (R(2) = 0.31, P = .02). CONCLUSION PSV and Vr appear to have a significant role in predicting in-stent stenosis. To determine >or=80% stenosis, combining PSV >or=275 cm/s and Vr >or=3.50 is highly specific and predictive.

Multilevel versus isolated endovascular tibial interventions for critical limb ischemia

OBJECTIVE Endovascular interventions for critical limb ischemia (CLI) continue to have variable reported results. The purpose of this study is to determine the effect of disease level and distribution on the outcomes of tibial interventions. METHODS A retrospective analysis of all tibial interventions done for CLI between 2006 and 2009 was performed. Outcomes of isolated tibial (group I) and multilevel interventions (group II) (femoropopliteal and tibial) were compared. RESULTS Endovascular interventions were utilized to treat 136 limbs in 123 patients for CLI: 54 isolated tibial (85% tissue loss), and 82 multilevel (80% tissue loss). Mean age and baseline comorbidities were comparable. The mean ankle-brachial index (ABI) was significantly lower prior to intervention in group II (0.53 vs 0.74; P < .001) but was similar postintervention (0.86 vs 0.88; P = NS). Wound healing or improvement was achieved in 69% in group I and in 87% in group II (P = .05). Mean overall follow-up was 12.6 ± 5.3 months. Time to healing was significantly longer in group I: 11.5 ± 8.8 months vs 7.7 ± 6.6 months (P = .03). Limb salvage was achieved in 81% of group I and 95% of group II (P = .05). The rate of reintervention was similar (13% vs 18%, P = NS), so was the rate of late surgical conversion (0% vs 6%; P = NS). Limb loss resulted from lack of conduit or initial target vessel for bypass and high-risk systemic comorbidities. Overall mortality rates were similar among both groups. An isolated tibial intervention was a predictor of limb loss at 1 year on multivariate analysis and resulted in a lower rate of limb salvage at 1 year compared with multilevel interventions. Additionally, despite comparable primary patency rates, there was improved secondary patency with multilevel interventions compared with the isolated tibial interventions. Predictors of limb loss in patients treated with isolated tibial intervention included multiple synchronous tibial revascularization (P = .005) and advanced coronary artery disease requiring revascularization (P = .005). CONCLUSIONS Adequate rates of limb salvage can be achieved in patients undergoing multilevel interventions for CLI, and improved patency is seen with multilevel compared to isolated tibial interventions. Patients with isolated tibial disease appear to have a higher incidence of limb loss secondary to poor initial pedal runoff, more extensive distal disease, and severe comorbidities precluding surgical bypass. Other therapeutic strategies should be considered in these patients, including primary amputation or pedal bypass when applicable.

Outcomes of endovascular interventions for TASC II B and C femoropopliteal lesions

OBJECTIVE To evaluate outcomes of endovascular interventions on femoropopliteal occlusive disease and determine predictors of restenosis of Trans Atlantic Inter-Societal Consensus (TASC) II B and C lesions. METHODS All patients undergoing endovascular interventions for femoropopliteal occlusive disease between May 2003 and July 2007 were reviewed. Patient demographics, pre- and post-procedure ankle-brachial indices (ABI), and anatomic factors (including categorization by TASC II classification, lesion length, and runoff vessel status) were analyzed. Outcomes evaluated included freedom from restenoses, freedom from re-intervention, overall patency, and assisted-patency. RESULTS A total of 237 total limbs were treated during the period reviewed. The study group included 108 TASC B and 32 TASC C limbs in 125 patients (mean age 73.1 +/- 10.4 years, male sex: 59%). Seventy-one percent of patients were Rutherford classification 2/3 while the remaining 29% were Rutherford classification 4/5. Mean follow-up period was 12.7 months (range, 1-52 m). Forty-one (41) limbs experienced restenosis or occlusion at a mean time of 8 months (range, 1-24 m). Freedom from restenosis/occlusion was 58.9% at 12 months and 47.9% at 24 months. Predictors of restenosis included a preoperative ABI <0.5 (hazard ratio [HR] 3.05, 95% confidence interval [CI] 1.36-6.86, P = .007) and hypercholesterolemia (HR 2.42, 95% CI 1.11-5.25, P = .025). Lesion length as a continuous variable (per centimeter) also correlated with a higher risk of restenosis (HR 1.06, 95% CI 1.00-1.12, P = .057). The overall assisted-primary and secondary-patency rates were 87% and 94% respectively at 3 years with no significant differences between TASC B and TASC C limbs. CONCLUSION Endovascular interventions for TASC II B and C lesions are associated with restenosis/occlusion rates that are at least as good as those of open femoropopliteal bypass surgery from historical, previously published series. Furthermore, overall assisted-patency rates are excellent, although low preoperative ABIs continue to be associated with worse outcomes.

Long-term outcomes of internal carotid artery dissection

OBJECTIVE The natural history of acute carotid artery dissection is poorly characterized. The purpose of this study is to report on single institutional long-term outcomes. METHODS A retrospective review of patients treated for acute spontaneous or posttraumatic carotid artery dissection over a 20-year period from August 1989 to July 2009 was performed. RESULTS Twenty-nine patients with a mean age of 47 ± 19.6 years were identified with acute carotid dissection. Six (25%) were related to trauma, while 23 (79%) were spontaneous. Neurologic symptoms included contralateral limb weakness (55%), facial pain (35%), and Horners syndrome (21%). Eight patients (28%) presented with an acute hemispheric stroke. Diagnostic imaging modalities used included computed tomography angiography (52%), magnetic resonance angiography (41%), and conventional angiography (48%). Twenty percent of patients had complete carotid occlusion and 25% had near occlusion. Most dissections (65%) had intracranial extension, and 35% were limited to the extracranial cervical internal carotid. The majority (96%) of patients were treated conservatively with anticoagulation or antiplatelet therapy or both. One patient underwent stenting for persistent symptoms resulting in complete recovery. There were two deaths, one from unrelated traumatic injuries and the other from unknown causes. Long-term follow-up was available for 20 patients: 14 had complete symptom resolution (70%) and five (25%) had partial clinical symptom resolution. Two patients had initial resolution of symptoms, with subsequent recurrence that was successfully managed conservatively. Follow-up imaging revealed luminal patency in 79% of patients with minimal residual stenosis. Two patients developed a small asymptomatic internal carotid aneurysm that did not require treatment. Mean follow-up was 1133.2 days. CONCLUSIONS Most cervical carotid dissections can safely be conservatively managed, with the majority achieving anatomic and symptomatic resolution, with low rates of recurrence over long-term follow-up.

Limitations of the Outback LTD re-entry device in femoropopliteal chronic total occlusions

OBJECTIVE Subintimal recanalization for the treatment of femoropopliteal chronic total occlusions (CTO) occasionally requires re-entry devices to access the true lumen distally, but limited information is available on factors predicting the success or failure of these devices. We evaluated the Outback LTD re-entry device (LuMend, Redwood City, Calif; acquired by Cordis Corp, Miami Lakes, Fla). METHODS A retrospective review of patients with femoropopliteal CTO from August 2006 to August 2009 was performed. Age, gender, occlusion length, site of re-entry, and the angle of the aortic bifurcation were recorded. Procedural angiograms were used to assign a calcification score (none, mild, moderate, severe) at the re-entry site. Univariate and multivariate logistic regression analyses were used to identify factors predicting failure of re-entry into the true lumen. RESULTS Of 249 CTOs treated, the re-entry device was used 52 times (20.9%): 47 superficial femoral artery (SFA) occlusions and 5 combined SFA and popliteal artery occlusions (33 TransAtlantic InterSociety Consensus II type C and 18 type D lesions). Of 48 procedures with available angiograms for review, the target re-entry site was at the adductor canal in 30 (62.5%), the above-knee popliteal artery in 13 (27.1%), behind the knee joint in 4 (8.3%), and the mid-SFA in 2 (4.2%). Patients (54% men) were a mean age of 73.1 years. Re-entry was successful in 34 attempts (64.5%). Causes of failure included inability to re-enter the true lumen in 11 (61.1%), difficulty tracking the device over a wire in 3 (16.7%), acute angle of aortic bifurcation in 2 (11.1%), mechanical failure of the device in 1 (5.6%), and difficulty tracking the device through the lesion in 1 (5.6%). Moderate or severe calcification at the site of re-entry was the only significant predictor of failure (odds ratio, 6.3; 95% confidence interval, 1.45-24.48; P = .01). An aortic bifurcation angle ≥40° did trend toward predicting success (odds ratio, 0.23; 95% confidence interval, 0.05-1.02; P = .054). CONCLUSIONS Although the Outback re-entry device can be successful in extending the applicability of endovascular management to difficult femoropopliteal occlusions, it is not uniformly successful in current clinical practice. Significant calcification at the proposed re-entry site is a strong predictor of failure.

Contemporary outcomes of endovascular interventions for acute limb ischemia

OBJECTIVE Thrombolysis as a treatment for acute limb ischemia (ALI) has become a first-line therapy based on studies published over 2 decades ago. The purpose of this study was to assess outcomes of patients treated for ALI using contemporary thrombolytic agents and endovascular techniques. METHODS Consecutive patients with ALI of the lower extremities treated between 2005 and 2011 were identified, and their records were retrospectively reviewed. All patients were treated with tissue plasminogen activator delivered via catheter-directed thrombolysis (CDT) and/or pharmacomechanical thrombolysis (PMT), with other adjunctive endovascular or surgical interventions. Procedural success, thrombolysis duration, and 30-day and long-term outcomes were obtained for the whole series and were also compared between the CDT and PMT groups. Limb salvage and survival were assessed using time-to-event methods, including Kaplan-Meier estimation and Cox proportional hazards models. RESULTS A total of 154 limbs were treated in 147 patients presenting with ALI (Rutherford class I, 9.7%; class IIa, 70.1%; class IIb, 20.1%). The mean follow-up was 15.20 months (range, 0.56-56.84 months). Indications for intervention included embolization (14.3%), thrombosed bypass (36.4%), thrombosed stent (26.6%), native artery thrombosis (24.0%), and thrombosed popliteal aneurysm (3.2%). Technical success was achieved in 83.8% of cases, with a 30-day mortality rate of 5.2%. Procedural complications included systemic bleeding (5.2%), access site hematoma (4.5%), acute renal failure (1.9%), and distal embolization (9.7%). The mean runoff score decreased from 13.42 preintervention to 7.43 postintervention. Adjuvant revascularization procedures were required in 89.0% of patients and were endovascular (68.8%), hybrid (9.1%), or open (11.0%). Only 3.2% of patients required a fasciotomy. The overall rate of major amputation was 15.0% (18.1% for CDT only, 11.3% for PMT; P = NS). Predictors of limb loss by Cox proportional hazards models included end-stage renal disease (hazard ratio [HR], 8.563; P < .001) and poor pedal outflow, with an incremental protective effect for improved pedal outflow (HR, 0.205; P < .001 for one pedal outflow vessel; HR, 0.074; P < .001 for ≥ two pedal outflow vessels). Gender, smoking, diabetes, Rutherford score, runoff score, thrombosed popliteal aneurysm, and PMT were not significant predictors of limb loss. The use of PMT was a significant predictor of technical success (odds ratio, 2.67; P = .046). CONCLUSIONS Endovascular therapy with thrombolysis using tissue plasminogen activator remains an effective treatment option for patients presenting with mild or moderate lower extremity ALI, with equal benefit derived with CDT or PMT. Patients with end-stage renal disease or poor pedal outflow have an increased risk of limb loss and may benefit from alternative revascularization strategies.

Comparative effectiveness of endovascular versus surgical revascularization for acute lower extremity ischemia

OBJECTIVE Thrombolysis and open surgical revascularization are current options for the treatment of acute limb ischemia (ALI). Despite the several randomized controlled trials comparing the two options, no single treatment can yet be recommended as a universal initial management of ALI. The purpose of this study was to evaluate contemporary endovascular and surgical revascularization for ALI. METHODS Consecutive patients with ALI treated with endovascular revascularization (ER) or open revascularization (OR) between 2005 and 2011 were identified and reviewed. Procedural success and outcomes were compared between the two groups. Limb salvage and survival were assessed by time-to-event methods, including Kaplan-Meier estimation and competing-risks regression models. RESULTS A total of 154 limbs were treated in 147 patients in the ER group, compared with 326 limbs in 296 patients in the OR group. The mean follow-up was 14 ± 18.5 months. The majority of patients presented with Rutherford II ischemia (83% for OR, 90% for ER). In Rutherford II patients, technical success was achieved in 90.7% of the OR group vs 79.9% of the ER group (P = .002), with amputation rates of 10.0% vs 7.2% (P = .35) at 30 days and 16.3% vs 13.0% (P = .37) at 1 year, respectively. In Rutherford II patients with failed bypass graft, technical success rate was 95.0% (OR) vs 75.0% (ER) (P = .001), whereas the amputation rate was 6.3% vs 15.38% (P = .13) at 30 days and 24.1% vs 23.1% (P = .90) at 1 year, respectively. The overall 30-day mortality rate was 13.2% (OR) and 5.4% (ER) (P = .012). Overall amputation rates were 13.5% (OR) vs 6.5% (ER) at 30 days (P = .023) and 19.6% (OR) vs 13.0% (ER) at 1 year (P = .074). The primary patency rate was 57% (OR) and 51% (ER) at 1 year (P = .74). Predictors of limb loss by life-table analysis included coronary artery disease (hazard ratio [HR], 2.0; P = .007) and Rutherford category III (HR, 19.0; P < .001). Predictors of death by life-table analysis included age (HR, 1.03; P < .001), end-stage renal disease (HR, 7.28; P < .001), cancer (HR, 1.65; P = .005), and chronic obstructive pulmonary disease (HR, 1.61; P = .005). CONCLUSIONS In patients presenting with class II ALI, ER or surgical OR resulted in comparable limb salvage rates. Although technical success is higher with OR for patients presenting with failed bypass grafts, the amputation rates are comparable. Overall mortality rates are significantly higher at 30 days and 1 year in the OR group.