Iliac arterial conduits for endovascular access: technical considerations

Use of a prosthetic conduit for stent delivery in transcarotid artery revascularization for patients with unfavorable anatomy

Transcarotid artery revascularization (TCAR) provides a safe alternative to carotid endarterectomy. The anatomic requirements include a 5-cm minimum clavicle to carotid bifurcation distance for sheath access proximal to the lesion. In the present report, we describe our experience with conduit use for patients not meeting that requirement. Patients undergoing elective TCAR with a conduit from 2021 to 2022 were retrospectively identified. After carotid artery exposure, a 6-mm prosthetic graft was anastomosed to the common carotid artery in an end-to-side fashion. After stent delivery, the conduit was ligated and oversewn. The patient demographics, procedural details, and outcomes were recorded and compared with our nonconduit TCAR experience. A total of 11 patients (64% male; age, 75 ± 5 years) underwent TCAR with a conduit, 5 (46%) for symptomatic disease, and 77 patients underwent TCAR with no conduit, 52 (60%) with symptomatic disease (P = .50). Other than a higher rate of prior coronary interventions in the conduit group (55% vs 47%; P = .007), no significant differences were found in age, gender, race, comorbidities, or high risk for carotid endarterectomy criteria. In the conduit group, the average skin to carotid artery depth was 4.2 cm (range, 1.9-6.1 cm). The average clavicle to bifurcation distance was 4.4 cm (range, 3.3-4.9 cm) vs 6.5 cm (range, 3.3-9.7 cm; P = .002) in the nonconduit group. Dacron was the most common conduit material used (73%). No differences were found in the mean procedure times (121 ± 32 vs 129 ± 53 minutes; P = .785) or flow reversal times (14 ± 5 vs 19 ± 13 minutes; P =.989) for the conduit and nonconduit cohorts, respectively. Technical success was achieved in 100% of the conduit and nonconduit cases. Excluding one outlier of a prolonged stay (7 days) for management of unrelated medical issues (gastrostomy tube placement for chronic dysphagia after mass resection and neck radiation), the mean hospital stay was 2 days (1.2 ± 0.4 intensive care unit days) compared with 3.8 ± 5.7 days for our nonconduit cohort (P = .2). Hypotension was the most common reason for delayed discharge for the conduit group (n = 3; 27%). The average follow-up was 2.7 months (range, 1-10 months). For all 11 conduit patients, the stent remained patent without stenosis, thrombus, or pseudoaneurysm at the conduit stump site on surveillance duplex ultrasound. No strokes or complications had occurred at 30 days in the conduit group compared with four strokes or transient ischemic attacks (P = .469) and 18 minor complications in the nonconduit group (P = .091). For patients lacking a sufficient distance between the clavicle and carotid artery bifurcation, a prosthetic conduit facilitates safe use of flow reversal for stent delivery and can be ligated at procedural completion without consequences.

Endovascular Repair of Complex Aortic Aneurysms

Fenestrated-branched endovascular aortic repair (FB-EVAR) has gained widespread acceptance in patients with complex aortic aneurysms. It has evolved from an alternative to treat elderly and higher risk patients to the first line of treatment in most patients with suitable anatomy, independent of the clinical risk. Currently, these devices are available off-the-shelf (ready to use) and tailored to the patient anatomy with the options of fenestrated, branched and mixed fenestrated, and branched designs. Reports from single and multicenter experiences and systematic reviews have shown lower mortality and morbidity for FB-EVAR compared with historical results of open surgical repair. The main advantages are noted on mortality, respiratory complications, acute kidney injury, and length of hospital stay. The purpose of this article is to review the advances in the endovascular repair of complex aortic aneurysms exploring the indications for treatment, preoperative evaluation, patient selection, device design, and implantation technique.

Iliac Conduits for Endovascular Treatment of Aortic Pathologies: A Systematic Review and Meta-analysis

PURPOSE

The treatment of thoracoabdominal aortic aneurysm has largely shifted to endovascular techniques. However, severe iliofemoral arterial disease often presents a challenge during these interventions. As a result, iliac conduits have been introduced to facilitate aortic endovascular therapy. The goal of the current study was to gauge utilization and to analyze iliac artery conduit outcomes to facilitate endovascular therapy to treat aortic pathologies.

MATERIALS AND METHODS

A meta-analysis of 14 studies was conducted with the use of random effects modeling. The incidence of periprocedural adverse events was gauged based on iliac conduit vs nonconduit cases and planned vs unplanned iliac conduit placement. Outcomes of interest included length of hospital stay, morbidity and mortality associated to conduits, and all-cause mortality.

RESULTS

Iliac conduits, either open or endo-conduits, were utilized in 17% (95% CI: 9%-27%) of 16,855 cases, with technical successful rate of 94% (95% CI: 80%-100%). Periprocedural complications occurred in 32% (95% CI: 22%-42%) of the cases, with overall bleeding complication rate being 10% (95% CI: 5%-16%). Female patients, positive history for smoking, pulmonary disease, and peripheral artery disease at baseline were associated with more frequent utilization of iliac conduits. Conduit use was associated with longer hospitalization, higher periprocedural all-cause mortality (OR: 2.85; 95% CI: 1.75-4.64; p<0.001), and bleeding complication rate (OR: 2.38; 95% CI: 1.58-3.58; p<0.001). Sensitivity analysis among conduit cases showed that planned conduits were associated with fewer periprocedural complications compared to unplanned conduits (OR: 0.38; 95% CI: 0.20-0.73; p=0.004).

CONCLUSION

Iliac conduit placement is a feasible strategy, associated with high technical success to facilitate complex aortic endovascular repair. However, periprocedural adverse event rate, including bleeding complications is not negligible. All-cause mortality and morbidity rates among cases that require iliac conduits should be strongly considered during clinical decision making. High-quality comparative analyses between iliac conduit vs nonconduit cases and between several types of iliac conduit grafts aiming at facilitating endovascular aortic repair are still needed to determine the best strategy to address challenging iliac artery accesses.

How to do it: a modified transabdominal wall approach for direct external iliac artery access during endovascular thoracic aneurysm repair

We describe the combined application of a transabdominal wall sheath tunnel, 'pre-close' purse-string sutures and manual external support of the iliac artery to facilitate introduction of an 18F sheath for endovascular exclusion of a 6-cm thoracic aortic aneurysm.

Perioperative Outcomes in Patients Requiring Iliac Conduits or Direct Access for Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Iliac conduit or direct iliac access (ICDA) can be used when anatomy is unfavorable for femoral access during abdominal endovascular aortic aneurysm repair (EVAR). The impact of this approach has not been adequately addressed. The objective of this study was to analyze perioperative outcomes of patients requiring use of ICDAs for EVAR.

METHODS

Patients undergoing EVAR with and without ICDA were identified in the 2005-2012 National Surgical Quality Improvement Program data sets. Perioperative morbidity and mortality were assessed by crude comparison of matched groups and multivariate analyses.

RESULTS

Of 15,082 patients undergoing infrarenal EVAR 147 (1%) required ICDA. The ICDA group had a higher proportion of females (25.9% vs. 17.8%, P = 0.017), peripheral vascular disease (12.9% vs. 5.5%, P = 0.001), and patients with a history of dyspnea (31.3% vs. 23.1%, P = 0.024). There was no difference in age (74.5 ± 8.4 conduit vs. 73.5 ± 8.5). On multivariate analysis, the ICDA cohort had a higher rate of mortality (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.4-5.4; P = 0.004) and an increase in other major complications including cardiac arrest and/or myocardial infarction (OR, 2.9; 95% CI, 1.3-6.3; P = 0.007), pulmonary complications (OR, 2.1; 95% CI, 1.2-3.9; P = 0.013), and postoperative length of stay (means ratio, 1.3; 95% CI, 1.1-1.4; P = 0.001). There was a trend toward increased bleeding complications with ICDA. Matched analyses of comorbidities revealed that patients requiring ICDA had higher perioperative mortality (6.8% vs. 2.3%, P = 0.008), cardiac (4.8% vs. 1%, P = 0.004), pulmonary (8.8% vs. 3.4%, P = 0.006), and bleeding complications (10.2% vs. 4.6%, P = 0.016).

CONCLUSIONS

Our results demonstrate that the use of ICDA during EVAR is associated with increased morbidity and mortality. In situations where anatomy mandates the use of iliac conduits or access for EVAR, surgeons should consider this increased risk. Open repair or the use of lower profile devices, if possible, should be considered as options for these patients.

Iliac anatomy and the incidence of adjunctive maneuvers during endovascular abdominal aortic aneurysm repair

Purpose

Challenging iliac anatomy remains an important issue during endovascular aneurysm repair (EVAR), and it is known that the length of the common iliac artery (CIA) is shorter in Asians than in Western groups. We analyzed both the iliac anatomy and the incidence of adjunctive maneuvers to overcome iliac artery-related difficulties during EVAR.

Methods

Seventy-four EVARs were performed for abdominal aortic aneurysm between January 2010 and March 2013. Patient demographic data, iliac anatomical characteristics (presence of iliac artery aneurysm, iliac artery diameter and length, and iliac tortuosity), and adjunctive iliac artery maneuvers were reviewed retrospectively.

Results

Mean CIA length was 52.8 mm (range, 6.6-98.0 mm) on the right and 56.3 mm (range, 0-94.8 mm) on the left. CIA length was ≥20 mm, except in one patient with bilateral short CIAs. Forty patients (54%) had a CIA aneurysm, and 18 had aneurysms on both sides. Iliac adjunctive procedures were performed in 38 patients (51%) as follows: 23 internal iliac artery (IIA) embolizations or ligations, seven IIA revascularizations, 16 external iliac artery (EIA) balloon angioplasties or stenting, one EIA patch angioplasty, one EIA interposition, two femoral endarterectomies with patch angioplasty, and nine femoro-femoral bypasses after EVAR with an aorto-uni-iliac device. Technical success for the adjunctive iliac procedures was achieved in all patients.

Conclusion

Short CIA length was uncommon. Although many patients had access-related difficulties, most were overcome by an endovascular or hybrid technique. Liberal use of iliac adjunctive procedures can facilitate EVAR.

Reconstruction of the internal iliac artery in patients with aneurysmal disease: Two case reports

During the endovascular repair of aortoiliac aneurysm, bilateral internal iliac artery (IIA) occlusion may give rise to significant morbidities such as ischemia of buttock or sigmoid colon and erectile dysfunction. Open and endovascular approaches are used to maintain IIA circulation in such cases. The present report describes the cases of two patients who underwent external-to-internal iliac artery bypass surgery, one via a novel hybrid approach. The first patient had a right common iliac artery aneurysm without a sufficient distal landing zone for endovascular repair. The distal landing of the device was therefore placed in the right external iliac artery (EIA). The tortuous portion of the right EIA was excised and anastomosed in an end-to-end fashion. An external-to-internal iliac artery bypass was then performed. The second patient underwent endovascular repair of the IIA aneurysm with a Gore^® Viabahn^®-covered stent (W. L. Gore and Associates, Inc., Flagstaff, AZ, USA). This covered stent was anastomosed with the iliac bypass graft. Postoperative pelvic circulation was maintained. In conclusion, this strategy for maintaining IIA flow is a potential novel approach for future use.

Endovascular abdominal aortic aneurysm repair in patients with renal transplant

The repair of abdominal aortic aneurysm (AAA) in patients with functioning renal transplant is critical because it is important to avoid ischemic and reperfusion injury to the transplanted kidney. Endovascular aneurysm repair (EVAR) avoids aortic cross clamping and can prevent renal graft ischemia. Here we report the endovascular management and outcome of AAA in two renal transplant patients using a bifurcated aortic stent graft. One patient underwent EVAR using a small amount of contrast (30 mL) due to decreased renal function resulting from chronic rejection. Another patient had EVAR performed with iliac conduit because of the heavily calcified, stenotic lesion of external iliac artery. EVAR in patients with a renal transplant is a feasible option without impairing renal arterial flow.

Technical challenges in endovascular repair of complex thoracic aortic aneurysms

BACKGROUND

Endovascular aneurysm repair has gained widespread acceptance, and there has been a significant increase in the number of aneurysms treated with stent grafts. However, the endovascular technique alone is often not appropriate for anatomically complex aneurysms involving the neck branches. We used the TAG stent for thoracic aortic aneurysms (TAA), and report our initial results.

PATIENTS AND RESULTS

We deployed 80 TAG stents in 65 patients electively treated with TAA between June 2006 and June 2008. Thoracic endovascular aneurysm repair (TEVAR) was performed in 45 cases of descending aortic aneurysm with no morbidity or mortality. A combination of open surgery and TEVAR was performed in 11 out of 20 cases with aneurysms of the aortic arch. The prior total arch replacement and elephant trunk procedure was performed in 3 cases with dilated ascending aorta, total debranching from ascending aorta with sternotomy in 5, and carotid-carotid artery crossover bypass in 3 cases. Meanwhile, TEVAR with coverage of the left subclavian artery was performed in the remaining 9 distal arch cases. In 3 cases with extremely short necks, a 0.018" guide wire was inserted percutaneously in a retrograde manner through the common carotid artery (CCA) into the ascending aorta to place the stent graft in close proximity to the CCA (wire protection). In 1 of these 3 cases, the TAG stent was deployed through the CCA, and the 0.018" guide wire was used to deliver a balloon-expandable stent in order to restore the patency of the CCA. In arch and distal arch aneurysm cases, perioperative mortality and the incidence of stroke were both 5.0%; dissection of the ascending aorta was seen in one case (5.0%).

CONCLUSION

As treatment for descending aortic aneurysms, TEVAR can replace conventional open repair. However, TEVAR for arch aneurysms has some problems, and further improvement is necessary. (English Translation of Jpn J Vasc Surg 2010; 19: 547-555.).

Endovascular repair of thoracic aortic injury: current thoughts and technical considerations

Thoracic aortic traumatic injury is a highly morbid event. Mortality and paraplegia rates after emergent open repair remain high. Now, however, thoracic aortic endografting for trauma (TAET) is commonly used. It is appealing due to reduction of operative stress for the multiply injured trauma victim. This minimizing of stress and risk is secondary to avoidance of thoracotomy, single-lung ventilation, aortic cross-clamping, and the more complex anesthetic techniques required. Early and midterm results from TAET delineate improved outcomes, yet access and aortic constraints continue to challenge TAET. Questions regarding longer-term durability of endografts in younger patients remain unanswered. Broader application of TAET within endovascular programs is challenged by appropriate imaging, operating suite inventories, and the logistics and personnel required for TAET. Currently developed thoracic endograft devices are not ideal for TAET due to platform size and graft diameter. This is changing, however, as new modifications have been developed and trials are ongoing. In light of these collective factors, the management paradigm for traumatic aortic injury is beginning to favor TAET.

Successful treatment of an abdominal aortic aneurysm by endovascular graft placement through a previously placed prosthetic graft: Report of a case

A 77-year-old man with an infrarenal abdominal aortic aneurysm was referred with a complex medical history including pancreatitis, chronic renal failure, atrial fibrillation, and a cerebral infarction. He also had a history of atherosclerosis obliterans, treated with a vascular bypass using an 8-mm prosthetic graft 9 years previously. His complicated anatomy, including a small access route and a large common iliac artery, suggested usage of Powerlink, a bifurcated stent graft through the previously placed graft, as an access route. The patient was discharged from the hospital with a type III endoleak, which was completely resolved 5 months after discharge.

Standard of practice for the endovascular treatment of thoracic aortic aneurysms and type B dissections

Thoracic endovascular aortic repair (TEVAR) represents a minimally invasive technique alternative to conventional open surgical reconstruction for the treatment of thoracic aortic pathologies. Rapid advances in endovascular technology and procedural breakthroughs have contributed to a dramatic transformation of the entire field of thoracic aortic surgery. TEVAR procedures can be challenging and, at times, extraordinarily difficult. They require seasoned endovascular experience and refined skills. Of all endovascular procedures, meticulous assessment of anatomy and preoperative procedure planning are absolutely paramount to produce optimal outcomes. These guidelines are intended for use in quality-improvement programs that assess the standard of care expected from all physicians who perform TEVAR procedures.

Standard of practice for the endovascular treatment of thoracic aortic aneurysms and type B dissections

Thoracic endovascular aortic repair (TEVAR) represents a minimally invasive technique alternative to conventional open surgical reconstruction for the treatment of thoracic aortic pathologies. Rapid advances in endovascular technology and procedural breakthroughs have contributed to a dramatic transformation of the entire field of thoracic aortic surgery. TEVAR procedures can be challenging and, at times, extraordinarily difficult. They require seasoned endovascular experience and refined skills. Of all endovascular procedures, meticulous assessment of anatomy and preoperative procedure planning are absolutely paramount to produce optimal outcomes. These guidelines are intended for use in quality-improvement programs that assess the standard of care expected from all physicians who perform TEVAR procedures.

Alternative approach for endovascular treatment of aortic aneurysms

Endovascular treatment of thoracic aortic aneurysms is limited in patients with small or calcified femoral arteries, with the most serious complication being rupture at the insertion site or distal sections of the artery. To overcome this, an iliac conduit is normally created by surgical exposure. We used an original access in a patient with a thoracoabdominal aortic aneurysm and narrow femoral artery to introduce the endovascular prosthesis directly into the surgically exposed iliac artery by a small laparotomy and abdominal wall tunnel without iliac conduit. The endoprosthesis was easily implanted, and complete hemostasis was achieved with minimal blood loss.