Sean P. Lyden

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.

Hybrid Approaches to Thoracic Aortic Aneurysms: The Role of Endovascular Elephant Trunk Completion

Background— Thoracic aortic aneurysm affecting the arch and proximal descending thoracic aorta requires 2-stage repairs that include proximal elephant trunk graft placement and completion of thoracic or thoracoabdominal repair. The application of endovascular grafting to complete the proximal procedure avoids a thoracotomy and may improve the morbidity and mortality of the patient population at risk. Methods and Results— A retrospective review of 399 thoracic endovascular grafts at our institution between 2000 and 2004 identified 22 patients who required elephant trunk and endovascular completion. Three patients underwent mesenteric bypass in addition to their proximal repairs. Mean follow-up was 10 months (range 1 to 42 months); there were no ruptures, and all patients returned for follow-up. Technical success was achieved in all patients. The 1-, 12-, and 24-month mortality rates (by Kaplan-Meier analysis) were 4.5%, 15.8%, and 15.8%, respectively. Caudal migration of the endograft occurred in 1 patient, and all but 2 aneurysms decreased or remained stable in size. The 2 patients with growth included a type III endoleak (which resolved after treatment) and pressurization through an expanded PTFE stentgraft. Three cases of transient paraparesis occurred (all in patients requiring mesenteric bypass or abdominal aortic aneurysm repair), and there were no paraplegias or strokes. Conclusions— Endovascular completion of elephant trunks is feasible and can be accomplished with minimal mortality. Meticulous imaging follow-up is required to detect persistent aneurysm pressurization and to verify the integrity of the repair. Improvements in implant design and delivery systems will further simplify the second-stage portion of these complex aneurysm repairs.

Late conversion of aortic stent grafts

OBJECTIVES The frequency of late removal of endovascular abdominal aortic repair (EVAR) parallels the rise of endovascular aortic repair. Evaluation of outcomes for EVAR explants may identify risks for complications and alter clinical management. METHODS A patient database was used to identify EVAR patients requiring explant >1 month after implant. A retrospective analysis was conducted of the type of graft, duration of implant, reason for removal, operative technique, death, and length of stay. RESULTS During 1999 through 2007, 1606 EVARs were performed, and 25 patients required explantation, with an additional 16 referred from other institutions (N = 41). The average age was 73 years (range, 50-87 years); 90% were men. Grafts were excised after a median of 33.3 months (range, 3-93 months). Explanted grafts included 16 AneuRx (40%), 7 Ancure (17%), 6 Excluder (15%), 4 Zenith (10%), 4 Talent (10%), 1 Cook Aortomonoiliac rupture graft, 1 Endologix, 1 Quantum LP, and 1 homemade tube graft. Overall hospital mortality was 19% and occurred after conversion for rupture in 4, and in infected graft, aortoenteric fistula, repair of new aneurysm of the visceral segment, and claudication due to graft stenosis in one patient each. Elective EVAR-related mortality was 3.3%. Mortality was higher in patients with rupture compared with nonrupture (4 of 6 vs 3 of 35, P <or= .01). Thirty patients (73%) had one or more endoleaks (type I, 16; II, 9; III, 9; endotension, 5). Migration (n = 10), rupture (n = 6), aortoenteric fistula (n = 3), infection (n = 1), limb thrombosis (n = 3), and claudication (n =1) were also factors. Proximal aortic control was above the endograft (supravisceral, 23; suprarenal, 12; infrarenal, 6). Reconstruction was an aortoiliac repair in 63% and tube graft in 25%. Grafts with suprarenal fixation required longer proximal aortic clamp time of 43 minutes vs 28 minutes for infrarenal fixation. Complete graft removal was achieved in 85%. Proximal or distal portions of the endograft were incorporated into the repair in the remaining six. CONCLUSION Elective EVAR conversion, although technically challenging may be done with mortality similar to primary open repair. Mortality for conversion for infected grafts and ruptured aneurysms remains high. EVAR is associated with continued risk of conversion, and surveillance may identify late complications that require removal, justifying lifelong monitoring. Aggressive management of late complications and elective conversion may minimize the mortality associated with this procedure.

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.

Combined staged procedures for the treatment of thoracoabdominal aneurysms.

Purpose: To examine the efficacy of a staged approach for the treatment of thoracoabdominal aneurysms, with open visceral revascularization followed by aortic endografting, in selected patients not considered candidates for conventional surgical repair. Methods: A retrospective review was conducted of 13 consecutive patients (8 women; mean age 64 years, range 33–77) who underwent visceral bypass followed by endovascular thoracoabdominal stent-graft implantation since 1999. Three patients presented with symptomatic aneurysms and 2 with rupture. Two patients had connective tissue disorders. All patients were deemed unfit for conventional thoracoabdominal repair due to comorbid conditions. The procedures were tailored to the pathology and specific patient anatomical situation: 5 aortic dissections with aneurysmal degeneration and 8 aneurysms (5 Crawford type II, 2 type III, and 1 type IV). Results: The patients underwent retrograde visceral bypass (11 iliovisceral and 2 infrarenal aortic to visceral artery) followed by endovascular aortic relining with Zenith TX2 devices (n=7), homemade endografts (n=5), or a Talent thoracic endograft (n=1). Six patients required either a proximal or distal direct aortic repair (2 infrarenal reconstructions, 3 arch elephant trunk grafts, and 1 ascending aortic repair), while 3 patients also underwent left carotid-subclavian bypass grafting. Two patients developed paraplegia (1 following a ruptured aneurysm), and 2 patients had transient paraparetic events. Two patients had acute renal failure requiring short-term dialysis. Three patients died within 30 days; 2 late aneurysm-related deaths were noted. Three patients developed endoleaks during follow-up. Mean lengths of stay were 13 days (7–30) for the visceral bypass and 12 (3–25) for the endovascular stent-graft. In addition, remaining procedures in 8 patients required a mean of 7 days (0–14) in hospital. Conclusion: Staged endovascular and open procedures are feasible for thoracoabdominal aneurysms in patients at prohibitive risk for open thoracoabdominal reconstruction. However, this approach still carries a significant risk of perioperative mortality and morbidity. The potential for less invasive alternatives should be investigated.

Results of the United States multicenter prospective study evaluating the Zenith fenestrated endovascular graft for treatment of juxtarenal abdominal aortic aneurysms

OBJECTIVE This study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the Zenith fenestrated endovascular graft (Cook Medical, Bloomington, Ind) for treatment of juxtarenal abdominal aortic aneurysms (AAAs). METHODS Sixty-seven patients with juxtarenal AAAs were prospectively enrolled in 14 centers in the United States from 2005 to 2012. Custom-made fenestrated stent grafts were designed with one to three fenestrations on the basis of analysis of computed tomography data sets. Renal alignment was performed with balloon-expandable stents. Follow-up included clinical examination, laboratory studies, mesenteric-renal duplex ultrasound, abdominal radiography, and computed tomography imaging at hospital discharge and at 1 month, 6 months, and 12 months and yearly thereafter up to 5 years. RESULTS There were 54 male and 13 female patients with a mean age of 74 ± 8 years enrolled. Mean aneurysm diameter was 60 ± 10 mm. A total of 178 visceral arteries required incorporation with small fenestrations in 118, scallops in 51, and large fenestrations in nine. Of these, all 118 small fenestrations (100%), eight of the scallops (16%), and one of the large fenestrations (11%) were aligned by stents. Technical success was 100%. There was one postoperative death within 30 days (1.5%). Mean length of hospital stay was 3.3 ± 2.1 days. No aneurysm ruptures or conversions were noted during a mean follow-up of 37 ± 17 months (range, 3-65 months). Two patients (3%) had migration ≥ 10 mm with no endoleak, both due to cranial progression of aortic disease. Of a total of 129 renal arteries targeted by a fenestration, there were four (3%) renal artery occlusions and 12 (9%) stenoses. Fifteen patients (22%) required secondary interventions for renal artery stenosis/occlusion in 11 patients, type II endoleak in three patients, and type I endoleak in one patient. At 5 years, patient survival was 91% ± 4%, and freedom from major adverse events was 79% ± 6%; primary and secondary patency of targeted renal arteries was 81% ± 5% and 97% ± 2%, freedom from renal function deterioration was 91% ± 5%, and freedom from secondary interventions was 63% ± 9%. CONCLUSIONS This prospective study demonstrates that endovascular repair of juxtarenal AAAs with the Zenith fenestrated AAA stent graft is safe and effective. Mortality and morbidity are low in properly selected patients treated in centers with experience in these procedures.

Iliofemoral stenting for venous occlusive disease

BACKGROUND Venous hypertension is a significant cause of patient morbidity and decreased quality of life. Common etiologies of venous hypertension include deep venous thrombosis (DVT) or congenital abnormalities resulting in chronic outflow obstruction. We have implemented an aggressive endovascular approach for the treatment of iliac venous occlusion with angioplasty and stenting. The purpose of this study was to determine the patency rates with this approach at a large tertiary care center. MATERIALS/METHODS All patients undergoing iliofemoral venous angioplasty and stenting over a 4-year period were identified from a vascular surgical registry. Charts were reviewed retrospectively for patient demographics, the extent of venous system involvement, the time course of the venous pathology, and any underlying cause. Technical aspects of the procedure including previous angioplasty or stenting attempts and presence of collaterals on completion venogram were then recorded. Patency upon follow-up was determined using primarily ultrasound scans; other imaging methods were used if patency was not clear using an ultrasound scan. RESULTS A total of 36 patients (40 limbs) were stented from January 2005 through December 2008. Of these patients, 27 were women (75%). Both lower extremities were involved in 4 patients. Thrombolysis was performed in 19 patients (52.8%). Thrombosis was considered acute (<30 days) in 13 patients (38%). The majority of patients who had a recognized underlying etiology were diagnosed with May-Thurner syndrome (15 patients; 42%). In 9 patients, an etiology was not determined (25%). The mean follow-up time period in the study population was 10.5 months. One stent in the study occluded acutely and required restenting. Primary patency rates at 6, 12, and 24 months were 88% (75.2-100), 78.3% (61.1-95.4), and 78.3% (61.1-95.4), respectively. Secondary patency rates for the same time frames were 100% (100.0, 100.0), 95% (85.4, 100.0), and 95% (85.4, 100.0). Better outcomes were seen in stenting for May-Thurner syndrome and idiopathic causes, whereas external compression and thrombophilia seemed to portend less favorable outcomes (P < .001). Symptomatic improvement was reported in 24 of 29 patients (83%) contacted by telephone follow-up. CONCLUSION Iliofemoral venous stenting provides a safe and effective option for the treatment of iliac venous occlusive disease. Acceptable patency rates can be expected through short-term follow-up, especially in the case of May-Thurner syndrome. Further experience with this approach and longer-term follow-up is necessary. Thrombophilia workup should be pursued aggressively in this population, and further studies should be undertaken to determine the optimal length of anticoagulation therapy after stent placement.

The nutcracker syndrome

Left renal vein (LRV) compression, commonly referred to as the nutcracker syndrome or renal vein entrapment syndrome, is a rare and often overlooked condition. Anatomically, the LRV traverses the space between the superior mesenteric artery and the aorta in close proximity to the origin of the artery. In affected individuals, the LRV is subjected to compression between these two structures, resulting in renal venous hypertension. A review of published data on this condition reveals either case reports or small case series. The classic symptoms of nutcracker syndrome include left flank pain with gross or microscopic hematuria. Patients are often children or young adults, with a slight predisposition for women who may also present with pelvic congestion symptoms such as pelvic pain and dyspareunia. Most patients have disease symptoms for many years and nondiagnostic investigations before proper diagnosis can be made. Appropriate diagnostic work-up and treatment may help alleviate patient morbidity from this chronic condition. Although surgical repair has been the standard of care, more recently endovascular intervention has become the first line of therapy. This tabular review compiles published cases in the adult population during the period between 1980 and 2009.

Endovascular Management of Chronic Infrarenal Aortic Occlusion

Purpose: To review our experience with the endovascular treatment of chronic infrarenal aortic occlusion with regard to technical success and midterm patency, as well as perioperative mortality and morbidity. Methods: A retrospective review was performed of patients who presented from January 1, 2000, to December 31, 2005, with a diagnosis of chronic infrarenal aortic occlusion (TASC D) treated with endovascular techniques. In this time period, 31 patients (22 women; mean age 63 years) underwent attempted recanalization of the occluded aorta and iliac arteries. Claudication was the most common presenting symptom (14, 45%). Patients were treated solely with angioplasty and stenting or thrombolysis followed by angioplasty/stenting based on surgeon preference. Results: Technical success was 93%. The 2 failures were individual cases of wire-induced iliac artery perforation and failed access; both patients were treated with bypass grafting. Nine (29%) patients had thrombolysis prior to angioplasty. There were no perioperative deaths. Postoperative ankle-brachial indexes increased significantly from preoperative values (p<0.0001). There were 3 technical complications: 1 (3%) iatrogenic iliac artery injury and 2 (6%) perioperative limb thromboses requiring intervention. Other complications included 6 (19%) access site events and 5 (16%) episodes of acute renal dysfunction, 2 requiring permanent dialysis. Over a mean follow-up of 12 months, there was no limb loss. At 1 and 3 years, the primary/secondary patency rates were 85%/100% and 66%/90%, respectively. Conclusion: Endovascular therapy for chronic infrarenal aortic occlusion has a high technical success rate, with good midterm primary and secondary patency rates. However, renal dysfunction can occur; the etiology is likely multifactorial from contrast volumes, embolization, and/or renal arterial disease.

Treatment and outcomes of aortic endograft infection

OBJECTIVE This study examined the medical and surgical management and outcomes of patients with aortic endograft infection after abdominal endovascular aortic repair (EVAR) or thoracic endovascular aortic repair (TEVAR). METHODS Patients diagnosed with infected aortic endografts after EVAR/TEVAR between January 1, 2004, and January 1, 2014, were reviewed using a standardized, multi-institutional database. Demographic, comorbidity, medical management, surgical, and outcomes data were included. RESULTS An aortic endograft infection was diagnosed in 206 patients (EVAR, n = 180; TEVAR, n = 26) at a mean 22 months after implant. Clinical findings at presentation included pain (66%), fever/chills (66%), and aortic fistula (27%). Ultimately, 197 patients underwent surgical management after a mean of 153 days. In situ aortic replacement was performed in 186 patients (90%) using cryopreserved allograft in 54, neoaortoiliac system in 21, prosthetic in 111 (83% soaked in antibiotic), and 11 patients underwent axillary-(bi)femoral bypass. Graft cultures were primarily polymicrobial (35%) and gram-positive (22%). Mean hospital length of stay was 23 days, with perioperative 30-day morbidity of 35% and mortality of 11%. Of the nine patients managed only medically, four of five TEVAR patients died after mean of 56 days and two of four EVAR patients died; both deaths were graft-related (mean follow-up, 4 months). Nineteen replacement grafts were explanted after a mean of 540 days and were most commonly associated with prosthetic graft material not soaked in antibiotic and extra-anatomic bypass. Mean follow-up was 21 months, with life-table survival of 70%, 65%, 61%, 56%, and 51% at 1, 2, 3, 4, and 5 years, respectively. CONCLUSIONS Aortic endograft infection can be eradicated by excision and in situ or extra-anatomic replacement but is often associated with early postoperative morbidity and mortality and occasionally with a need for late removal for reinfection. Prosthetic graft replacement after explanation is associated with higher reinfection and graft-related complications and decreased survival compared with autogenous reconstruction.