Vikram Paruchuri

Management of diseases of the descending thoracic aorta in the endovascular era: a Medicare population study.

Objective:Prospective trials have shown improved perioperative outcomes with endovascular repair of thoracic aortic (TEVAR) pathologies compared with conventional surgery (OPEN). There are no long-term population data detailing the impact of TEVAR on practice patterns and results of treatment of descending thoracic aortic pathology (DTA), which are the goal of this study. Methods:All procedures performed on the DTA captured in the Medicare database from 2004 to 2007 were identified by ICD-9 codes and stratified into OPEN and TEVAR cohorts. Outcomes included perioperative mortality (&khgr;2) and 5-year actuarial survival. Results:There were 11,166 patients identified (4838 [43%] TEVAR vs. 6328 [57%] OPEN) with 7247 (65%) nonruptured, degenerative thoracic aortic aneurysms (TAA), 2701 (24%) descending aortic dissections, 1033 (9%) thoracic aortic ruptures, and 185 (2%) traumatic aortic tears. The distribution of cases changed significantly during the study period (P < 0.0001) with an increase in TEVAR, decrease in OPEN, and increase in total cases over time (Table 1). The perioperative mortality was lower in the TEVAR group for the entire population (360 [7.4%] TEVAR vs. 1175 [18.5%] OPEN, P < 0.0001), and for the individual pathologies: TAA (182/3529 [5%] TEVAR vs. 451/3718 [12%] OPEN, P < 0.001), dissections (76/833 [9%] TEVAR vs. 399/1868 [21%] OPEN, P < 0.001) and ruptures (87/368 [24%] TEVAR vs. 298/665 [45%] OPEN, P < 0.0001). The Kaplan–Meier curve significantly favored TEVAR for the entire cohort because of the early mortality of the OPEN cohort but the curves converged by 5 years. The 5-year survival by indication was: entire population (53.4% TEVAR vs. 53.3% OPEN, P < 0.0001), TAA (55.8% TEVAR vs. 59.7% OPEN, P = 0.84), dissection (58.2% TEVAR vs. 50.6% OPEN, P < 0.0001), ruptures (23.3% TEVAR vs. 25.3% OPEN, P = 0.001), and trauma (62.9% TEVAR vs. 50.9% OPEN, P = 0.12). Conclusion:There has been a significant increase in the use of TEVAR for management of diseases of the DTA. TEVAR offers a significant perioperative survival advantage when compared with OPEN regardless of the indication for repair. However, in the Medicare population, the 5-year survival is similar between the 2 cohorts.

Thoracoabdominal aneurysm repair: Hybrid versus open repair

OBJECTIVE Hybrid repair of thoracoabdominal aortic aneurysms (TAAA) may reduce morbidity and mortality in high-risk candidates for open repair. This study reviews the outcomes of hybrid TAAA repair for Crawford extent I-III TAAA in high-risk patients in comparison to patients who underwent concurrent open TAAA repair. METHODS During the interval from June 2005 to December 2007, a total of 23 high-risk patients with TAAA (type I: 9 [39%], II: 5 [22%], and III: 9 [39%]) underwent renal and/or mesenteric debranching (11 [48%] with four vessel debranching) with subsequent placement of a thoracic stent graft; 77 patients underwent open TAAA repair (type I: 13 [17%], II: 11 [14%], III: 27 [35%], and IV: 26 [34%]) during the same interval. The primary high-risk criteria for hybrid TAAA included advanced age/poor functional status (n = 14), major pulmonary dysfunction (n = 8), and technical consideration (prior thoracic aortic aneurysm repair [n = 4] or prior thoracoabdominal aneurysm repair [n = 2] and obesity [n = 2]) with 6 patients having overlapping high-risk criteria. Composite (30-day) mortality and/or permanent paraplegia (PP) were the major study endpoints. RESULTS The hybrid and open TAAA groups had (respectively) no statistical difference in mean age (76.6 vs 72.7 years), aneurysm size (6.51 vs 6.52 cm), and non-elective operation (30.4% vs 26.0%). The hybrid group had a higher mean Society for Vascular Surgery (SVS) risk score (9.1 vs 6.0; P <or= .001), incidence of oxygen-dependent chronic obstructive pulmonary disease (COPD) (34.8% vs 2.6%; P <or= .001), and prior thoracic (n = 4) or thoracoabdominal (n = 2) repair (26.1% vs 1.3%; P <or= .001). Composite mortality and/or PP was doubled in the hybrid group (21.7% vs 11.7%; P = .33). The rate of any type of reoperation was higher in hybrid TAAA repair (39.1% vs 20.8%; P = .03). One year actuarial survival for both groups was comparable (hybrid, 68 +/- 12%; open, 73 +/- 6%). A total of 5/23 (22%) hybrid TAAA patients developed an endoleak (type I: 3/23 and type II: 2/23) with 3 requiring endovascular re-intervention. A total of 7/70 (10%) visceral/renal bypass grafts were noted to be occluded during follow-up (1 superior mesenteric artery, 1 celiac, and 5 renal). Examination of patients with an SVS risk score <or=8 (mean SVS risk score in hybrid 6.2 [n = 10] vs 5.5 [n = 68] in open; P = .27) revealed the hybrid group had a higher incidence of composite mortality and/or PP (40% vs 10.3%; P = .03). CONCLUSION Hybrid TAAA repair in high-risk patients has significant morbidity and mortality suggesting a non-interventional approach may be appropriate in many such patients. The morbidity and mortality of the hybrid TAAA repair was substantial even in lower risk patients (SVS risk score <or=8), albeit patient numbers were small. Prospective study in comparable patient risk cohorts is required to define the role of hybrid TAAA repair.

Endovascular management of patients with critical limb ischemia

BACKGROUND Although percutaneous intervention (PTA) is considered first-line therapy for peripheral vascular disease in many scenarios, its role in critical limb ischemia (CLI), wherein anatomic disease is more extensive, remains unclear. In the present study, late (5-year) clinical and patency data for PTA in CLI are defined. METHODS From January 2002 to December 2007, 409 patients underwent infrainguinal PTA ± stent for CLI (Rutherford IV-VI) of 447 limbs. Primary patency, assisted patency, limb salvage, and survival were assessed using Kaplan-Meier. Predictors of patency, limb salvage, and death were determined using multivariate models. RESULTS Demographics included age (70 ± 12 years old), diabetes (65.8%), and dialysis dependence (13%). The superficial femoral artery was treated in 58% of the patients, 16% were limited to the crural vessels, 38% had multilevel treatment, and stents were placed in 26%. Eighty percent of patients received postprocedure clopidogrel. Mean follow-up was 28 months (0-83). Five-year primary and assisted patency were 31% ± 0.04 and 75% ± 0.04, respectively. Limb salvage at 5 years was 74% ± 0.038. Sixty-three patients had major amputations. Survival at 5 years was 39% ± 0.03. Multivariate analysis identified dialysis dependence (P = .0005; 2.7 [1.6-4.8]), ≤1 vessel runoff (P = .02; 1.5 [1.1-2.0]), and warfarin use (P = .001; 1.7 [1.25-2.3]) as negative predictors of primary patency, but none of these were negative predictors of assisted patency. Dialysis dependence (P = .006; 2.5 [1.3-4.8]), female gender (P = .02; 2.0 [1.1-3.7]), and ≤1 vessel run-off (P = .04; 1.8 [1.0-3.2]) predicted limb loss. Dialysis dependence (P = .0003; 2.3 [1.5-3.5]), diabetes (P = .04; 1.5 [0.5-2.1]), and poor run-off (P = .04; 1.6 [1.2-2.1]) were predictors of mortality. CONCLUSION Although primary patency is low, excellent limb salvage rates can be achieved in patients with CLI through close follow-up and secondary interventions. These data, and the 12% annual death rate, validate PTA as first-line therapy in patients with CLI.

Secondary intervention after endovascular abdominal aortic aneurysm repair.

Objective:Endovascular Abdominal Aortic Aneurysm Repair (EVAR) has been criticized because of the need for frequent secondary interventions (2ndINT) to maintain effective abdominal aortic aneurysm (AAA) exclusion. The study goal is to detail such interventions and determine their effect on clinical outcomes. Methods:From January 1997 to December 2007, 832 patients underwent EVAR. Those requiring 2ndINT were stratified according to the indications and specific nature of 2ndINT and treatment. Study endpoints included freedom from 2ndINT, aneurysm-related and overall survival. Results:There were 91 (11%) patients who underwent 131 2ndINT (mean follow-up 35 months). No demographic features (age, gender, etc) predicted the need for 2ndINT. Actuarial 5-year freedom from 2ndINT was 80%. Indications for 2ndINT included: sac rupture 5 (4%), graft migration/ type I endoleak 37 (28%), persistent type II endoleak 40 (38%), endotension with sac growth 5 (4%), and limb occlusion/kinking 24 (18%). The majority of 2ndINT were accomplished with an endovascular approach (76%) with a >80% initial success rate for all indications except type II endoleak in which the initial intervention was successful only 34% of the time. Initial 2ndINT were successful in 62% and 35 (38%) patients underwent more than one 2ndINT. Multivariate predictors of 2ndINT were AAA sac size >5.5cm (OR = 2.1, P = 0.004), and preprocedure coil embolization (hypogastric or inferior mesenteric artery) (OR = 2.1, P = 0.008). The actuarial survival was 70% at 5 years and the aneurysm-related survival was 97.5% with no difference in either parameter in patients who underwent 2ndINT compared with those who did not. Conclusions:Although 2ndINT are common after EVAR, most were addressed through an endovascular approach; technical success thereof varies widely with the specific indication for 2ndINT. Secondary intervention did not adversely affect aneurysm-related or overall actuarial 5-year survival.

Intermediate-term outcomes of endovascular treatment for symptomatic chronic mesenteric ischemia.

OBJECTIVE Endovascular therapy for chronic mesenteric ischemia (CMI) has been increasingly utilized. Early outcomes compare favorably with open mesenteric bypass--the current gold standard. The goal of this study is documentation of intermediate-term anatomic and functional outcomes of endovascular mesenteric revascularization for symptomatic CMI. METHODS This is a retrospective review of all patients undergoing endovascular treatment of symptomatic CMI from July 2002 to March 2008. Study endpoints included periprocedural mortality, major morbidity, patency, symptomatic recurrence, and survival. Endpoints were analyzed using actuarial methods. RESULTS Sixty-six mesenteric arteries (78.8% stenotic/21.2% occluded) were treated in 49 patients. One or more vessels were treated in each case; however, four mesenteric artery total occlusions (3 SMAs/1 IMA) could not be crossed. Initial symptom relief was noted in 89.8% (n = 44) with no change in 5 patients. Single-vessel treatments were performed in 32 patients (65.3%) and two-vessel interventions in 17 (34.7%). The 30-day mortality rate was 2.0% (n = 1). Major complications occurred in 8 patients (16.3%). The mean follow-up duration was 37.4 +/- 2.98 months (range, 0-66). Restenosis on follow-up imaging occurred in 64.9% (n = 24) of the 37 patients who had radiographic surveillance at a mean follow-up interval of 8.5 +/- 1.9 months and was diagnosed most often by Duplex scan or computed tomographic angiography (CTA). Fourteen patients (28.6%) developed recurrent symptoms with 13 requiring a reintervention. Actuarial 36-month freedom from symptomatic recurrence was 60.9% +/- 9.4%. Two-vessel treatment was protective against symptom recurrence (P = .0014) and reintervention (P = .0060) by univariate analysis. A total of 19 reinterventions were required in 14 patients (28.6%) at a mean of 17 months from the original treatment. Primary patency at 36 months was 63.9 +/- 8.5%. Actuarial survival at 48 months was 81.1% +/- 6.1% with no CMI-related deaths in the study cohort. CONCLUSION Intermediate (3-year) follow-up indicates that significant restenosis and symptom recurrence are common following the endovascular treatment of symptomatic CMI. Thirty percent of the cohort required a reintervention, one-third of which were conversions to surgical reconstruction. Similar to the surgical paradigm of two-vessel revascularization, endovascular treatment of multiple mesenteric arteries produced better outcomes. A first-line endovascular approach to patients with CMI is a reasonable clinical strategy, but close follow-up is mandatory.

Long-Term Outcomes of Diabetic Patients Undergoing Endovascular Infrainguinal Interventions

OBJECTIVE Diabetes mellitus (DM) has traditionally predicted poor outcomes after lower extremity revascularization for peripheral vascular disease (PVD). This study assessed the influence of DM on long-term outcomes of percutaneous transluminal angioplasty, with or without stenting (PTA/stent), in patients with PVD. METHODS From January 2002 to December 2007, 920 patients underwent 1075 PTA/stent procedures. Patients were stratified into DM and non-DM cohorts. Study end points included primary patency (PP), assisted patency (AP), limb salvage, and survival and were evaluated using Kaplan-Meier and Cox regression analyses. RESULTS There were 533 DM and 542 non-DM limbs. Median follow-up was 34 months. Overall, the 5-year actuarial PP was 42% +/- 2.4%, AP was 81% +/- 2.0%, limb salvage was 89% +/- 1.6%, and survival was 60% +/- 2.4%. On univariate analysis, DM vs non-DM was associated with inferior 5-year PP (37% +/- 3.4% vs 46% +/- 3.3%; P = .009), limb salvage (84% +/- 2.6% vs 93% +/- 1.8%, P < .0001), and survival (52% +/- 3.5% vs 68% +/- 3.1%, P = .0001). AP did not differ between DM and non-DM patients (P = .18). In the entire cohort, DM (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.01-1.54; P = .04), single-vessel peroneal runoff (HR, 1.54; 95% CI, 1.16-2.08; P = .003), and dialysis (HR, 1.59; 95% CI, 1.10-2.33; P = .02) were associated with decreased PP on multivariate analysis. The only variables on multivariate analysis to predict limb loss and death were critical limb ischemia (HR, 9.09; 95% CI, 4.17-20.00; P < . 0001; HR, 2.99; 95% CI, 2.01-4.44; P < .0001, respectively) and dialysis (HR, 2.94; 95% CI, 1.39-5.00; P = .003; HR, 4.24; 95% CI 2.80-6.45; P < .0001, respectively). CONCLUSIONS DM is an independent predictor of decreased long-term primary patency after PTA/stent. Although acceptable assisted patency rates can be achieved with close surveillance and reintervention, long-term limb salvage remains inferior in diabetic patients compared with non-diabetic patients due to a more severe clinical presentation and poor runoff.

Effect of chronic dissection on early and late outcomes after descending thoracic and thoracoabdominal aneurysm repair

OBJECTIVE Although chronic aortic dissection (CD) has traditionally been considered a predictor of perioperative morbidity and mortality after descending thoracic/thoracoabdominal aneurysm repair (thoracoabdominal aortic aneurysm [TAA]), recent reports have rejected this assertion. Still, few contemporary studies document late outcomes after TAA for CD, which is the goal of this study. METHODS From August 1987 to December 2005, 480 patients underwent TAA; 73 (15%) CD and 407 (85%) degenerative aneurysms (DA). Operative management consisted of a clamp-and-sew technique with adjuncts in 53 (78%) CD and 355 (93%) DA patients (P < .001). Epidural cooling was used to prevent spinal cord injury (SCI) in 51 (70%) CD and 214 (53%) DA patients (P = .007). Study end points included perioperative SCI/mortality, freedom from reintervention, and long-term survival. RESULTS CD patients were younger (mean age 64.5 years CD vs 72.5 years DA, P < .001) and more frequently had a family history of aneurysmal disease (23% CD vs 6% DA, P < .001). Forty-three (59%) CD patients had elective TAA (vs 322 (79%) DA, P = .001). Eleven (15%) CD patients had Marfans syndrome (vs 0% DA, P < .001), and 17 (23%) CD patients had a prior arch or ascending aortic repair (vs 16 [4%] DA, P < .001). CD patients were more likely to have Crawford type I & II thoracoabdominal aneurysms (44 [60%] vs 120 [29%] DA, P < .001), while only two (3%) CD patients had type IV aneurysms (vs 99 [24%] DA). There was no difference in perioperative mortality between the two groups (11% CD vs 8.6% DA, P = .52), nor was there a difference in flaccid paralysis, which occurred in five (7%) CD and 22 (5%) DA patients (P = .92). At 5 years, 70% of CD patients were free from reintervention versus 74% of DA (P = .36). The actuarial survival was 53% and 32% at 5 and 10 years for CD versus 47% and 17% for DA (P = .07). CONCLUSIONS Despite increased operative complexity, CD does not appear to increase perioperative SCI or mortality after TAA when compared with DA. Long-term freedom from aneurysm-related reintervention is similar for both groups as is survival, despite patients with CD being of younger age at presentation.

Balloon expandable stents facilitate right renal artery reconstruction during complex open aortic aneurysm repair.

OBJECTIVE Patients undergoing repair of thoracoabdominal (TAA) or visceral aortic segment aneurysms typically require reconstruction of the renal arteries. The use of balloon expandable stents (BES) has been proposed as an alternative to endarterectomy or bypass for renal artery reconstruction (RAR) during open aortic aneurysm repair. We report technical aspects and long-term patency data for this method of right RAR during complex open aortic aneurysm repair. METHODS During the interval July 1, 2005 to December 31, 2007, a total of 67 patients underwent right RAR using a BES during concomitant TAA (type I: n = 2 [2.9%], type II: n = 8 [11.9%], type III: n = 13 [19.4%], and type IV: n = 22 [32.8%]), juxtarenal (n = 9 [13.4%]) or suprarenal (n = 13 [19.4%]) AAA repair. Indications for RAR were orificial stenosis (n = 21 [31%]) and/or technical considerations referable to the proximal aortic suture line. Patency of the renal stent was evaluated in patients with computed tomography angiography using three-dimensional reconstruction or with abdominal duplex evaluation at follow-up. RESULTS The mean patient age was 75.1 years, 54.4% were male, and 18% of operations were in nonelective circumstances. Twenty-seven (39%) out of 67 patients had a preoperative creatinine level > or = 1.4 mg/dL. Two patients (2.9%) developed permanent renal failure postoperatively (neither related to renal artery occlusion). Mean radiologic follow-up was 405 days (11-1281) with 98% stent patency noted. One patient had an early stent occlusion noted at 1 month. An additional patient was noted to have a nonflow-limiting dissection distal to the renal stent, and another was noted to have distal migration of the stent beyond the renal ostium; however, these findings were clinically silent. CONCLUSIONS The use of BES during complex open aortic aneurysm repair affords a rapid and durable mode of RAR, obviating the need for endarterectomy and its associated technical complications.