Treatment of complex abdominal aortic aneurysms by a combination of endoluminal and extraluminal aortofemoral grafts

Aorto-Uni-Iliac Stent Grafting and Femoro-Femoral Bypass in a Patient with a Failed and Catastrophic Endovascular Aortic Aneurysm Repair

A 78-year-old man presented at Eulji University Hospital due to an abdominal aortic aneurysm with maximum diameter of 52 mm, which had been increased from 45 mm over 6 months. He underwent embolization of the left internal iliac artery with vascular plug, prior to endovascular abdominal aortic repair with a bifurcated stent graft system. Unfortunately, the inserted vascular plug was maldeployed and protruded into left external iliac artery, and caused acute limb ischemia. Because revascularization of the occluded segment was failed, emergent hybrid approach with aorto-uni-iliac stent grafting and femoro-femoral bypass was done, successfully.

Outcomes After Use of Aortouniiliac Endoprosthesis Versus Modular or Unibody Bifurcated Endoprostheses for Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

OBJECTIVES

Outcomes after endovascular repair (EVAR) of ruptured abdominal aortic aneurysms (rAAAs) have been widely published. There is, however, controversy on the role of the use of aortouniiliac endoprosthesis (AUI) versus modular or unibody bifurcated endoprosthesis (MUB) for repair of rAAAs. We study and compare 30-day outcomes after use of AUI and MUB for all rAAAs focusing specifically on patients with instability.

MATERIALS AND METHODS

Patients who underwent EVAR for rAAA (n = 425) using AUI (n = 55; 12.9%) and MUB (n = 370; 87.1%) were identified from the American College of Surgeons' National Surgical Quality Improvement Program (2005-2010) database. Univariable and multivariable logistic regression analyses were performed.

RESULTS

No significant difference ( P > .5) was seen in comorbidities between patients who underwent EVAR with AUI or MUB; there was also no change in endoprosthesis use from 2005 to 2010 ( P = .7). Patients who underwent EVAR with AUI more commonly had a history of peripheral arterial procedure (10.9% vs 4.6%; P = .053) and preoperative transfusion of >4 U packed red blood cells (18.2% vs 6.8%; P = .004). Use of AUI versus MUB was associated with more 30-day wound complications (16.4% vs 6.2%; P = .01), return to operating room (38.2% vs 20.0%; P = .003), and mortality (34.5% vs 21.4%; P = .03). On multivariable analysis, use of AUI was associated with an increased risk of 30-day mortality (odds ratio: 2.4; 95% confidence interval: 1.1-5.3). On subanalysis of the cohort for only the patients with unstable rAAA (n = 159; AUI = 29 and MUB = 130), 30-day mortality for AUI versus MUB was still higher but not statistically significant (44.8% vs 32.3%; P = .2).

CONCLUSION

Endovascular repair for ruptured AAA using aortouniliac endoprosthesis is associated with higher 30-day mortality than using modular or unibody bifurcated endoprosthesis.

Evaluation the Aortic Aneurysm Remodeling After a Successful Stentgraft Implantation

Background

Routine imaging follow-up after endovascular treatment of abdominal aortic aneurysms (EVAR) is mainly aimed at detection of endoleaks. The aim of the study was to assess changes in the size of the abdominal aortic aneurysm sack using CT angiography (CTA) after successful treatment using endovascular stent graft implantation.

Material/Methods

A retrospective analysis of CTA results included 102 patients aged 54–88, who had no postoperative complications. Patients underwent CTA before EVAR and after the treatment (mean time between studies, 7.6 months). The largest cross-sectional area of the aneurysm sac was measured using a curved multiplanar reconstruction. A change of the aneurysm cross-sectional over 10% was considered significant.

Results

The average cross-sectional area decreased after EVAR by 3% and this change was not statistically significant. Regression of the cross-sectional area was observed in 18.6% of patients, progression was in 23.5%, and no change was seen in 57.8%. Cross-sectional areas before and after EVAR were significantly correlated (r=0.75, p<0.0001). There was no correlation between the cross-sectional area change after EVAR and patients’ age or the time between the treatment and the follow-up CTA. Cross-sectional area before the treatment predicted changes in the aneurysm size after EVAR (p=0.0045).

Conclusions

Remodeling of abdominal aortic aneurysms after EVAR is not uniform. The change of aneurysm size depends on the initial aneurysm size but not on the time from EVAR. The size of the aneurysm after EVAR should not be considered as a measure of the treatment efficacy.

Endovascular Repair of Early Rupture of Dacron Aortic Graft

Complications after open aortic surgery pose a challenge both to the vascular surgeon and the patient because of aging population, widespread use of cardiac revascularization, and improved survival after aortic surgery. The perioperative mortality rate for redo elective aortic surgery ranges from 5% to 29% and increases to 70–100% in emergency situation. Endovascular treatment of the postaortic open surgery (PAOS) patient has fewer complications and a lower mortality rate in comparison with redo open surgical repair. Two cases of ruptured abdominal aortic aneurysm (AAA) were managed with the conventional open surgical repair. Subsequently, spiral contrast computer tomography scans showed reperfusion of the AAA sac remnant mimicking a type III endoleak. These graft-related complications presented as vascular emergencies, and in both cases endovascular aneurysm repair (EVAR) procedure was performed successfully by aortouniiliac (AUI) stent graft and femorofemoral crossover bypass. These 2 patients add further merit to the cases reported in the English literature. This highlights the crucial importance of endovascular grafts in the management of such complex vascular problems.

Early Experience with the Sydney and EVT Prostheses for Endoluminal Treatment of Abdominal Aortic Aneurysms

Purpose:

The aim of this study was to report early experiences with the Sydney and Endovascular Technologies (EVT) prostheses for the treatment of abdominal aortic aneurysms (AAA) deemed suitable for endoluminal tube graft repair.

Methods:

Consecutive endoluminal tube graft repairs were analyzed over the first 12 months in which the Sydney and EVT prostheses were used. Patients eligible for the EVT prosthesis had type I AAAs: a proximal neck length ≥ 2 cm, a distal cuff length ≥ 1.5 cm, and nontortuous iliac arteries ≥ 8 mm. Selection criteria for the Sydney device were more liberal and included AAAs that had distal cuffs < 1.5 cm. During the study period, 28 of 91 patients evaluated for AAA repair were thus selected for endoluminal grafting: 18 patients received the Sydney endograft and 10 the EVT device. Medical comorbidities were present in slightly less than one third of patients in both groups. Contrast-enhanced computerized tomography (CT) was performed preoperatively, within 10 days of operation, and at 6 and 12 months postprocedure.

Results:

All endografts were successfully deployed in both groups. Postprocedural CT scans revealed incomplete aneurysm exclusion in four patients with the Sydney endograft. Subsequent deployment of a second endograft sealed these “leaks” in two cases; the other two were converted to open repair (89% clinical success). No leaks were seen with the EVT device. Local/vascular complications occurred in 33% of the Sydney group compared with 20% for the EVT device (p = 0.001); systemic sequelae were more common in the EVT group (30% versus 17% in the Sydney cohort, p = 0.002). There were no deaths within 30 days; three late deaths were not procedure related.

Conclusion:

AAAs that are suitable for endoluminal tube graft repair may be treated with a high rate of initial success with either the Sydney or EVT prostheses. More liberal selection criteria may increase the likelihood of local/vascular complications.

The Effect of Angulation on Intravascular Ultrasound Imaging Observed in Vascular Phantoms

Purpose:

To quantify the error introduced by noncoaxial intravascular ultrasound (IVUS) imaging and to evaluate the use of a balloon-tipped catheter in compensating for intraluminal angulation and subsequent dimensional inaccuracy.

Methods:

The effect of noncoaxial IVUS imaging was investigated in both a polyvinyl chloride phantom and an in vitro canine aorta using a calibrated setup to measure angulation off axis. Imaging was performed at increasing angulation (creating an elliptical image) in both phantoms, with the transducer centered and off center. Diameters were compared to the original coaxial diameter, as well as calculated diameters based on specific angles off axis. The percentage change (error) was also calculated at these angles. The measurements were repeated using a balloon-tipped catheter to center the transducer.

Results:

The measured diameters and percentage changes compared closely with their calculated counterpart. Up to 25° off axis, the apparent increase in diameter measurement was nearly 10%. Angulation from 30° to 70° resulted in an increase of 15% to 192%. Use of the centering balloon reduced the amount of error by 70% to 85% but was limited to angles ≤ 25° due to the design of the test apparatus.

Conclusions:

The error introduced by noncoaxial IVUS imaging can be significant and may be partially corrected by the use of a centering balloon. Further studies in the clinical application of a centering device are warranted.

A Prospective Study of Changes in Morphology and Dimensions of Abdominal Aortic Aneurysms following Endoluminal Repair: A Preliminary Report

Purpose:

The aim of this prospective study was to analyze early changes in morphology and dimensions of abdominal aortic aneurysms (AAA) following endoluminal repair.

Methods:

Forty-two of 62 patients undergoing endoluminal repair of AAAs between May 1992 and November 1994 were potentially available for follow-up at 6 months or longer after operation. After excluding patients with failed endoluminal repairs, patients who died within 6 months of operation, and patients with anastomotic aneurysms, a study group of 30 patients remained. Contrast-enhanced computed tomography (CE-CT) was performed preoperatively, within 10 days of operation, and at 6 and 12 months postprocedure. Based on the postoperative CE-CT findings, patients were divided into two groups: those with no extravasation of contrast into the aneurysmal sac (group I; n = 26), and those in which there was contrast extravasation (“leak”) into the aneurysmal sac (group II; n = 4).

Results:

The mean maximum diameters of AAAs in group I diminished progressively at 6 and 12 months, while those in group II increased. Twenty-three (88%) patients in group I had decreased diameter of AAA, while all patients in group II had progressive increase in AAA diameter. Patients who had an increase in AAA diameter had a significantly higher incidence of leak compared with those who had a decrease in diameter (p = 0.001).

Conclusions:

The majority of AAAs in which the sac has been excluded from the general circulation diminish in size following successful endoluminal repair. An increase in size occurs in those AAAs in which a communication exists between the aortic lumen and the sac. These results suggest that successfully excluded AAAs that continue to increase in size should be suspected of having an undetected leak.

A New Nonstented Balloon-Expandable Graft for Straight or Bifurcated Endoluminal Bypass

Purpose:

The aim of this study was to determine the feasibility of endoluminal grafting of aneurysms using a new design of nonstented endograft.

Methods:

Initial studies were undertaken in bench models and by implantation of endografts into animal vessels. Between May 1992 and June 1994, endoluminal repair of aneurysms was undertaken in 47 patients (44 male, 3 female). A new balloon-expandable endoluminal graft was developed and has now been studied in 25 of these 47 cases. This graft does not require adjunctive use of a vascular stent because of its unique construction, which incorporates metallic implants (graft attachment device or “GAD”) into the graft material. The design is applicable to endovascular grafting of occlusive arterial disease, as well as aneurysms. All patients were investigated by duplex scan, calibrated angiogram, and angio-CT scan and then allocated into groups that we defined according to the following criteria: group I, considered suitable for transfemoral implantation of a straight tube graft (n = 12); group II, unsuitable for transfemoral tube graft because of short neck of aneurysm, absent distal neck, or diseased iliac arteries (n = 10); and group III, peripheral aneurysms (n = 3). All patients were followed by clinical examination, duplex scan, and CT scan, with selective use of angiography.

Results:

Intraluminal deployment of the graft was achieved in all 25 patients; however, 3 patients from group II subsequently required conversion to open procedures because of the following complications: (1) partial graft thrombosis resulting from inadvertent omission of systemic anticoagulation during deployment (n = 1); and (2) unsuccessful deployment of the contralateral limb of a bifurcated graft in the iliac artery (n = 2). Successful endoluminal repair was achieved in 100% of patients in groups I and III, compared to 70% in group II.

Conclusions:

These preliminary results (in a series of high-risk patients) have demonstrated that endoluminal abdominal aortic aneurysm repair with this graft can be achieved reliably and with low morbidity in patients who fulfill the selection criteria (group I) and in peripheral aneurysms (group III), but the results were less satisfactory in aneurysms that do not have a good proximal or distal neck or in patients with diseased iliac arteries (group II). Further modification of the bifurcated version of this graft design, together with improvements in access techniques and graft materials, is required for successful endoluminal grafting in a wider range of patients.

Common Iliac Artery Access during Endovascular Thoracic Aortic Repair Facilitated by a Transabdominal Wall Tunnel

Purpose:

To describe a technique for common iliac artery (CIA) access during endovascular aortic aneurysm repair when unfavorable angulation between the CIA and the delivery sheath precludes direct arterial access.

Technique:

After retroperitoneal exposure of the CIA, a puncture site is chosen inferolateral to the surgical incision, and an 18-G trocar/cannula is advanced in alignment with the CIA through the anterior abdominal wall or skin of the upper thigh into the retroperitoneal space. Serial dilatation is performed over a guidewire placed through the cannula to create the subcutaneous tract. The trocar/cannula is replaced over the wire, and the CIA is punctured under direct vision. The guidewire is then advanced into the proximal aorta. A CIA arteriotomy is performed and the delivery system introduced over the guidewire through the tunnel into the iliac artery.

Conclusions:

Retroperitoneal exposure of the CIA with tunneled transabdominal wall delivery of the stent-graft avoids both external iliac artery injury and creation of a temporary access conduit in patients with iliac tortuosity and/or occlusive disease.

Results of Autopsy 7 Months after Successful Endoluminal Treatment of an Infrarenal Abdominal Aortic Aneurysm

Purpose:

To report the results of a postmortem examination in a patient who died of unrelated causes 7 months following endoluminal treatment of an infrarenal abdominal aortic aneurysm (AAA).

Methods:

As part of an FDA Phase I pilot study, a 73-year-old man underwent successful endoluminal exclusion of an infrarenal AAA using a 9-cm-long endograft (Endovascular Grafting System). Seven months later, he succumbed to complications of a spontaneous esophageal rupture. At autopsy, the aorta was dissected in situ by a vascular surgeon and pathologist before being explanted in order to examine the wound healing characteristics at the aorta-endograft interface. Particular attention was also directed to the hooks composing the attachment system at each end of the endograft.

Results:

Macroscopic and microscopic examination revealed that the graft had completely excluded the aneurysm sac from the circulation and was incorporated into the aortic wall at the proximal neck and distal cuff. A smooth pannus of endothelial cells covered the proximal end of the endograft at the areas of contact with the aorta, while microscopic examination of the distal end of the graft revealed poorly formed, fibrinous pannus. The neointima deep to the endothelium consisted of a collagenous matrix containing myofibroblasts and histiocytes, providing evidence of healing between the endograft and aorta. Both renal arteries were clear of the proximal end of the endograft, but a previously unrecognized right lower pole renal artery with an extremely caudal origin was excluded from the aortic lumen. Each hook of the attachment system was seen protruding through the adventitia of the aorta. There was no evidence of trauma to the aortic wall or the surrounding tissues caused by these hooks.

Conclusion:

There appears to be evidence that an endoluminally placed aortic graft may be incorporated by the host aortic tissue.

Endoluminal Grafting for Percutaneous Aneurysm Exclusion in an Aortocoronary Saphenous Vein Graft: The First Clinical Experience

Purpose:

Aneurysms develop only rarely in aortocoronary saphenous vein grafts (SVGs), and the usual treatment is surgical replacement of the diseased segment. However, in patients at appreciable risk for redo surgery, alternative therapies are desirable. We report the first compassionate use of a percutaneously delivered endoluminal graft (ELG) for internal exclusion of an SVG aneurysm.

Methods:

A 47-year-old male with two coronary bypass procedures and SVG angioplasty presented with an 8-mm diameter aneurysm lying between 80% and 70% stenotic lesions in an SVG to the obtuse marginal branch. The risks of a third bypass operation were considerable, so the decision was made to attempt internal exclusion of the SVG aneurysm.

Results:

An ELG composed of 2.0-mm diameter unexpanded PTFE graft material with Palmaz stents for fixation was delivered with a low-profile system, but a second ELG was necessary for complete exclusion of the aneurysmal sac. Both ELGs were dilated after initial deployment. The patient was discharged after 9 days without sequelae, and he remains asymptomatic with arteriographically documented ELG patency 5 months after treatment.

Conclusions:

In this patient with limited therapeutic options, percutaneous aneurysm exclusion in an SVG was effective in restoring a viable blood conduit. It remains to be seen if ELGs have a potential in aortocoronary SVGs.

Endoluminal Grafting of Abdominal Aortic Aneurysms: Causes of Failure and Their Prevention

Purpose:

The aim of this study was to analyze the causes of failure of endoluminal grafting for abdominal aortic aneurysms (AAA) and to put forward proposals for preventing these failures.

Methods:

Since May 1992, endoluminal repair of aneurysms was undertaken in 47 patients. Forty-three of these patients had AAAs and are the basis of this study. All procedures were nonurgent and were performed in the operating room with the patient draped for an open repair in the event of failed endoluminal repair. Radiographic guidance was used to pass the endografts into the aorta via a delivery sheath introduced through the femoral or iliac arteries. The configuration of the endografts was tubular (n = 28), tapered aortoiliac/aorto-femoral (n = 11), and bifurcated (n = 4).

Results:

Successful endoluminal repair was achieved in 34 of 43 (79%) patients. The remaining nine were terminated in favor of an open repair. The causes of failure were problems with access (2), balloon malfunction (1), stent dislodgment (3), graft thrombosis (1), and inability to deploy the contralateral limb of a bifurcated graft (2). All failed endoluminal repairs proceeded to successful open repair. There was no perioperative mortality in patients undergoing endoluminal repair or in those whose endoluminal repair was converted to open operation.

Conclusions:

The failures of endoluminal grafting have been analyzed. Methods of avoiding access problems, balloon malfunction, and stent dislodgment have been defined and recommendations made.

Aortomonoiliac Endovascular Grafting: Difficult Solutions to Difficult Aneurysms

Purpose:

To describe a refined technique for aortomonoiliac endograft exclusion of abdominal aortic aneurysms (AAAs).

Methods:

A tapered aortomonoiliac graft was prepared from an 8-mm thin-walled expanded polytetrafluoroethylene tube graft predilated proximally to 35 mm and tapered distally to 15 mm. The proximal graft was sutured to a 5-cm-long, predilated Palmaz stent, which was mounted on a 30-mm balloon and backloaded into a 21F packaging sheath. With the patient under general anesthesia and both common femoral arteries exposed, the endograft was anchored in the infrarenal aorta and subsequently passed into one iliac system, where it was anastomosed to the iliac or femoral vessels. The contralateral common iliac artery was occluded, and an extra-anatomic, femorofemoral, or iliofemoral bypass grafting was performed.

Results:

Twenty of the 25 AAAs treated to date with this technique have been successful, with aneurysm exclusion achieved in 18 (2 minor distal endoleaks are scheduled for endovascular repair). The technical failures were analyzed, resulting in enhancements to the technique. Complications included 2 early (< 30 days) deaths, 1 case of minor embolization, 1 transient renal failure, 1 pulmonary embolus, and 1 wound infection. The only late complication was a graft infection localized to the groin.

Conclusions:

Aortomonoiliac endovascular aneurysm repair is effective in patients with AAAs involving the iliac arteries. Short-term results are acceptable, but long-term efficacy must be addressed before this procedure is widely adopted. Technical changes made in response to early learning curve problems have led to a safer, more reliable procedure.

European Experience with a System for Bifurcated Stent-Graft Insertion

Purpose:

To test an endovascular aneurysm exclusion system in the presence of a wide range of challenging anatomic features.

Methods:

Bifurcated endovascular stent-grafts were inserted in 52 patients and followed with serial computed tomography for up to 3 years. The device underwent several modifications during this time, the most significant of which represent the difference between the homemade (n = 42) and industry-made (n = 10) versions.

Results:

The initial procedural success rate was 92% in the homemade group and 100% in the industry-made group. In the 3 years of follow-up, the long-term success rate was 64% in the homemade group and 90% in the industry-made group. The primary reasons for failure in the homemade group were graft thrombosis due to kinking early in the series and proximal stent migration later in our experience. All cases of migration occurred when the neck was < 15 mm in length, the neck was lined with thrombus, or the stent was implanted > 15 mm from the renal arteries. Kinking was subsequently overcome by implanting Wallstents throughout the graft limbs. The sole failure in the industry-made group was a case in which collateral perfusion reached the aneurysm through patent lumbar arteries.

Conclusions:

The fruits of this experience are a better technique, a better device, and, most importantly, a better understanding of the system's limits, as reflected in the current selection criteria.

Three-Year Experience with the White-Yu Endovascular GAD Graft for Transluminal Repair of Aortic and Iliac Aneurysms

Purpose:

To report a > 3-year experience with a modular, balloon-expandable endovascular graft used for aneurysm exclusion in the aorta and other arteries.

Methods:

The customized White-Yu Endovascular GAD Graft, a woven polyester prosthesis with an intrinsic Elgiloy wire graft attachment system along the body of the graft, is a flexible endograft design available in straight, tapered, and bifurcated versions that can be delivered transluminally through 18F to 24F sheaths.

Results:

Since July 1993, 93 patients have received the White-Yu endograft for treatment of 76 abdominal aortic, 3 thoracic aortic, 13 iliac, and 1 popliteal aneurysms. Of the 79 aortic procedures, 39 involved straight tube grafts, 20 were tapered aortoiliac models, and 20 were bifurcated devices. Success rates for tube grafts were 81% in the abdominal aorta and 100% for the thoracic aorta; 5 primary endoleaks (14%) and 2 conversions to surgery (5.6%) occurred with this graft type. Aortoiliac grafts were deployed successfully in 95% (19/20) of cases with 1 conversion (5%) due to thrombosis. Seventy-five percent of the bifurcated endograft procedures were successful, with 4 conversions (20%) for technical failures and 1 graft thrombosis. Four additional endografts were deployed to treat two primary and two secondary endoleaks in tube graft patients. Two access-related arterial injuries were treated surgically. There was one case of embolus to the distal femoral artery but no microembolization. Overall perioperative (30-day) mortality was 3.1%. Over a mean 18-month follow-up (range 2 to 39), no late graft thrombosis, stenosis, or graft migration has been seen on CT scans or X ray. Endoleak has not been detected in any aortoiliac or bifurcated graft. Aneurysm size has diminished consistently in successfully treated cases.

Conclusions:

The White-Yu endograft appears to offer a safe, efficacious, and minimally invasive means of excluding aneurysms from the circulation. Improvements in patient selection, surgical techniques, and equipment have reduced the incidence of endoleak and conversion to open repair over the course of the evaluation.

Torsion and Kinking of Unsupported Aortic Endografts: Treatment by Endovascular Intervention

Purpose:

To describe the management strategies used to deal with twisted aortic endografts.

Methods and Results:

Two patients with successfully excluded aortic aneurysms developed symptoms referable to previously undetected twists in their endografts (one EndoVascular Technologies [EVT] and one customized aortomonoiliac device). The limb graft occlusion in the EVT graft was treated surgically with a femorofemoral bypass, but the aortomonoiliac endograft was salvaged with percutaneous implantation of a Wallstent. During another aortomonoiliac procedure, suboptimal flow through the endograft was traced to contortion of the endograft as it passed over an angulated proximal aneurysm neck. An X-large Palmaz stent was deployed to support the graft at this point.

Conclusions:

Unsupported aortic endografts may develop twists and kinks during deployment that can lead to low outflow and graft occlusion. Endovascular techniques are available to repair these defects postoperatively, although more precise intraoperative assessment tools may identify these problems so that they can be corrected at the initial intervention.

Abdominal Aortic Aneurysms: Experience with the Ivancev-Malmö Endovascular System for Aortomonoiliac Stent-Grafts

Purpose:

To describe a component-based aortomonoiliac stent-graft system and the first clinical results achieved with this device in endovascular abdominal aortic aneurysm (AAA) repair.

Methods:

From November 1993 to October 1996, 45 patients aged 60 to 86 years underwent endoluminal exclusion of true AAAs (median diameter 60 mm) involving the common iliac arteries (median diameter 16 mm right and 15 mm left) using unilimb stent-grafts deployed with the Ivancev-Malmö system.

Results:

Six immediate conversions occurred in the beginning of the series due to endografts that were too short. Complications, including 2 inadvertent renal artery occlusions, 7 kinked grafts, 6 iliac artery dissections, and 3 perioccluder leaks, were prominent features in the first 15 patients. Five patients died in the postoperative period, four of whom were nonsurgical candidates. There were five significant stent-graft migrations: one 3 weeks after surgery due to mechanical injury of the proximal stent and four after 1 year owing to continuous dilation of a wide proximal neck, stent-graft placement in a conical, thrombus-lined proximal neck, and two instances of proximal extension separation from the main graft. Translumbar aneurysm perfusion required embolization in 3 patients.

Conclusions:

Despite early complications associated with a learning curve, exclusion of large AAAs using unilimb stent-grafts is feasible. Strict inclusion criteria are necessary in order to improve mortality among nonsurgical candidates and minimize the risk for late migration.

An Experimental Model for the Acute and Chronic Evaluation of Intra-Aneurysmal Pressure

Purpose:

To develop an animal model for the acute and chronic monitoring of pressure within abdominal aortic aneurysms (AAAs) to be treated with endovascular grafts.

Methods:

A strain-gauge pressure transducer was placed within an AAA created from a prosthetic vascular graft. Prosthetic aneurysms were implanted into 17 canine infrarenal aortas. The intra-aneurysmal pressure was monitored and correlated with noninvasive forelimb sphygmomanometry for 2 weeks. After this time, an intravascular manometer catheter was passed into the aneurysm. Simultaneous pressure measurements were obtained using the implanted strain-gauge pressure transducer, the manometer catheter, and the forelimb sphygmomanometer. Angiography was performed to assess intraluminal morphology, aneurysm anastomoses, and adjoining aortic vessels. In addition, two control animals underwent intra-aneurysmal pressure monitoring after standard surgical aneurysm repair.

Results:

There was excellent correlation (r = 0.97) between the pressure measurements obtained with the implanted strain-gauge pressure transducer and the intravascular manometer. Close correlation was also observed between the implanted strain-gauge transducer and the forelimb sphygmomanometer (r = 0.88) during postprocedural monitoring. Intra-aneurysmal pressure was lowered dramatically by surgical exclusion (aneurysm: 15/5 ± 7/4 mmHg; systemic: 124/66 ± 34/17 mmHg; p < 0.001). The prosthetic aneurysms were successfully imaged with angiography.

Conclusions:

This animal model provides an accurate and reproducible means for measuring intra-aneurysmal pressure on an acute and chronic basis. It may be possible to use this model in the assessment of endovascular devices to determine their efficacy in reducing intra-aneurysmal pressure. Evaluation of complications associated with their use, such as patent aneurysm side branches, perigraft channels, and perianastomotic reflux, may also be possible.

Changes in Referral Practice, Workload, and Operative Mortality after Establishment of an Endovascular Abdominal Aortic Aneurysm Program

Purpose:

To determine the change in referral practice following establishment of an endovascular abdominal aortic aneurysm (AAA) program.

Methods:

A prospective audit of all elective admissions for AAA was established in January 1994 at the initiation of an endovascular AAA program. A comparison was made between this cohort and the elective AAA repairs performed between 1981 and 1993.

Results:

Since January 1994, 213 AAA patients (177 men; median age 73 years, range 54 to 88) have been referred for potential endovascular aneurysm repair. To date, 142 patients have undergone elective surgery (41 endovascular and 101 conventional). Between 1981 and 1993, 304 patients (255 men; median age 69 years, range 45 to 86) had elective aneurysm repair. Comparison of the two time periods has revealed significant increases in the number of tertiary referrals (41.8% versus 9.5%, p < 0.01), annual operations (50 versus 23, p < 0.05), and overall mortality (12% versus 6.7%, p < 0.05), the latter attended by a significant increase in cardiorespiratory comorbidity.

Conclusions:

The higher elective AAA mortality rate since the establishment of an endovascular program reflects a change in referral practice and may be directly attributable to an increase in the number of high-risk patients. An endovascular AAA program has clinical and financial implications for the hospital concerned.

Surgical Reconstruction of the Iliac Arteries Prior to Endovascular Aortic Aneurysm Repair

Purpose:

To explore a method of combined endovascular/conventional treatment of abdominal aortic aneurysm (AAA), in which the iliac arteries are reconstructed by conventional surgical techniques to provide the anatomic substrate for subsequent endovascular repair of the aortic aneurysm.

Method:

A 77-year-old patient with severe cardiac disease was found to have a 6.5-cm AAA, bilateral common iliac artery (CIA) aneurysms, and diffusely narrowed, tortuous external iliac arteries. The left internal iliac artery was occluded. At operation, the right CIA was exposed through a transverse retroperitoneal incision under epidural anesthesia. An iliobifemoral bypass was constructed using a preformed bifurcated graft. A stent-graft was delivered through the right limb of the bifurcated iliobifemoral graft. The proximal end of the stent-graft was implanted in the neck of the aneurysm, and the distal end was deployed in the common trunk of the iliobifemoral graft, thereby excluding the AAA and both native iliac arteries from prograde arterial flow.

Results:

Completion angiography and follow-up contrast computed tomography showed the aneurysm to be excluded from the circulation. The patient was not intubated, was never hemodynamically unstable, and had aortic blood flow interrupted for no more than 20 seconds. In addition, he was able to resume his usual diet on the first postoperative day. He continues to be well and without evidence of endoleak at 6-month follow-up.

Conclusions:

This case demonstrates that iliac artery stenosis, tortuosity, and aneurysmal dilatation are not impediments to endovascular AAA exclusion. Any necessary surgical modifications of pelvic arterial anatomy can be performed before stent-graft insertion to minimize aortic occlusion time.

Endoluminal Graft Exclusion of a Proximal Para-Anastomotic Pseudoaneurysm following Aortobifemoral Bypass

Purpose:

To describe a case of endoluminal graft exclusion of a proximal para-anastomotic pseudoaneurysm that occurred 17 years following aortobifemoral bypass for occlusive disease.

Methods and Results:

The lesion was found on abdominal ultrasound examination as part of a work-up for acute abdominal pain and upper gastrointestinal bleeding in a 67-year-old male. A 5-cm saccular pseudoaneurysm was confirmed by preintervention aortography and spiral computed tomography (CT) scanning. Because of the patient's acute symptoms and high-risk medical condition (cardiomyopathy), he was deemed a candidate for endoluminal bypass. At the time of intervention, intravascular ultrasound (IVUS) interrogation identified a 3.5-cm-long separation of the existing aortic graft from the proximal aortic stump with a large pseudoaneurysm. The lesion was isolated and repaired by placement of an aortic-to-right iliac endoluminal bypass, ligation of the left limb of the aortofemoral graft, and femorofemoral bypass to restore blood flow to the lower extremities. Spiral CT scans at 48 hours and 3 months following the procedure confirmed complete isolation of the lesion.

Conclusions:

This case illustrates the feasibility of endografting for repair of aortic para-anastomotic pseudoaneurysms, and it also highlights the potential role of IVUS imaging in endoluminal graft deployment.

Aortouni-iliac endografting as an alternative salvage procedure to open conversion in failed endovascular aneurysm repair

PURPOSE

To present a single-center experience with failed EVAR requiring conversions comparing open surgery to a minimally invasive procedure modifying the existing stent-graft into an aortouni-iliac (AUI) configuration.

METHODS

A prospectively maintained database at our tertiary care university hospital was interrogated to identify all patients with failed EVAR who had undergone either stent-graft modification into an AUI configuration or open conversion between March 1995 and January 2012. Patients with late aneurysm ruptures were excluded. The search found 30 patients (one had initial treatment elsewhere) who required conversion among the 688 patients who had undergone EVAR in that time period. Before conversion, 16 (53%) patients had prior endovascular corrections to maintain aneurysm exclusion.

RESULTS

An average time of 52.2 months (median 46.9, IQR 0.0-92.5) elapsed between initial EVAR and conversion. There were 11 early conversions (including 7 on-table), while 19 procedures were done >30 days post EVAR. Twenty-two (73%) patients underwent AUI endografting, while open conversions were carried out in 8 (27%). Mean hospital stay after conversion was 19.5 days (median 13.0, IQR 8.0-17.0). Overall mortality after conversion was 3.3% (1 patient after on-table open conversion), but since the introduction of AUI endografting as an alternative treatment approach, 30-day mortality following conversions fell to zero.

CONCLUSION

Modification of a failed stent-graft into an AUI configuration serves as a less invasive treatment option compared to open conversion and allows salvage of the failed device. With the implementation of this alternative approach, mortality after conversion parallels the mortality of elective abdominal aneurysm repair.

Abdominal aortic aneurysms: endovascular options and outcomes - proliferating therapy, but effective?

Abdominal aortic aneurysm (AAA) has a reported prevalence rate of 1.4% in the US. AAA rupture accounts for an estimated 15,000 deaths per year, rendering it the 10th leading cause of death in men over the age of 55. Endovascular repair (EVR) has proliferated in the last two decades as an increasingly popular alternative to traditional open surgery, and is now the default treatment in the majority of centres worldwide. This review article outlines the evidence supporting this stance. The development of EVR is reviewed, alongside trends in utilisation of this therapy over time. The evidence for the relative short-term and long-term outcomes of EVR and open AAA repair is discussed, and ongoing controversies surrounding the use of EVR are considered.

Abdominal aortic aneurysm: Treatment options, image visualizations and follow-up procedures

Abdominal aortic aneurysm is a common vascular disease that affects elderly population. Open surgical repair is regarded as the gold standard technique for treatment of abdominal aortic aneurysm, however, endovascular aneurysm repair has rapidly expanded since its first introduction in 1990s. As a less invasive technique, endovascular aneurysm repair has been confirmed to be an effective alternative to open surgical repair, especially in patients with co-morbid conditions. Computed tomography (CT) angiography is currently the preferred imaging modality for both preoperative planning and post-operative follow-up. 2D CT images are complemented by a number of 3D reconstructions which enhance the diagnostic applications of CT angiography in both planning and follow-up of endovascular repair. CT has the disadvantage of high cummulative radiation dose, of particular concern in younger patients, since patients require regular imaging follow-ups after endovascular repair, thus, exposing patients to repeated radiation exposure for life. There is a trend to change from CT to ultrasound surveillance of endovascular aneurysm repair. Medical image visualizations demonstrate excellent morphological assessment of aneurysm and stent-grafts, but fail to provide hemodynamic changes caused by the complex stent-graft device that is implanted into the aorta. This article reviews the treatment options of abdominal aortic aneurysm, various image visualization tools, and follow-up procedures with use of different modalities including both imaging and computational fluid dynamics methods. Future directions to improve treatment outcomes in the follow-up of endovascular aneurysm repair are outlined.

Access sites to vascular system for endovascular abdominal aortic aneurysms repair

The authors describe their experience with access sites for endovascular abdominal aortic aneurysm repair in a group of 165 patients treated over a 10-year period.

Concomitant unilateral internal iliac artery embolization and endovascular infrarenal aortic aneurysm repair

INTRODUCTION

Endograft limb extension to the external iliac artery with embolization of an internal iliac artery (IIA) may be necessary in patients with abdominal aortic aneurysms (AAAs) extending to the common iliac artery to prevent endoleak during endovascular aortic aneurysm repair (EVAR). Coil embolization of the IIA can be performed at the same operative setting as EVAR or, alternatively, as a staged procedure. Most interventionalists favor the latter approach to avoid excessive contrast material and prolonged operative time. We investigated the clinical outcome of concomitant vs staged unilateral IIA embolization in the setting of EVAR.

METHODS

Vascular surgeons at our institution treated 24 patients with infrarenal EVAR and unilateral coil embolization of the IIA from October 1, 2000 to June 30, 2005. All patients had normal renal function. The details of the operative procedure and perioperative complications were compared in patients undergoing concomitant vs staged procedures. Follow up was 1 to 40 months (average, 11 months).

RESULTS

Among the 24, 16 underwent concomitant unilateral IIA embolization in the setting of EVAR and eight patients underwent the staged procedure. Average duration of operative time (298 vs 284 minutes), amount of intravenous contrast (215 mL vs 164 mL), and preoperative (1.12 vs 1.26 mg/dL), and postoperative (1.15 v. 1.31 mg/dl) creatinine levels were similar in the concomitant vs staged group, respectively (P > .05 for all factors). More sensitive markers of renal insufficiency such as creatinine clearance were not measured. In the concomitant group, 25% (4/16) of patients reported significant symptoms of buttock claudication ipsilateral to the embolized IIA, which resolved after a mean of 8.8 months (range, 1 to 15 months) vs no cases (0/8) in the staged group (P = .02048). One patient in the staged group developed ischemic colitis, which was treated conservatively. Coil embolizations that were performed as staged procedures were all done on an outpatient basis. All 24 patients were admitted the day of the EVAR and were discharged the next day, except one patient in the concomitant group was discharged the second day after the procedure, and one patient in the staged group was discharged 7 days after the procedure.

CONCLUSION

Despite concern of prolonged operative time and the amount of contrast needed to perform concomitant IIA embolization and EVAR, our results showed that in patients with normal renal function, concomitant unilateral IIA embolization in the setting of EVAR was safe and effective and associated with shorter hospitalization compared with staged procedures. The disadvantage of a concomitant procedure is an increased likelihood of transient buttock claudication, but the small number of patients in this series prohibits definite conclusions about this complication. The concomitant procedure may be preferable for infirm patients with normal renal function who would be greatly inconvenienced by two procedures.

Computational flow dynamics in abdominal aortic aneurysm using multislice computed tomography

Following the introduction of a new multislice computed tomography (MSCT) scanner, it has become possible to produce high-speed CT angiography (CTA), the preferred method for imaging in emergent abdominal vascular conditions. Unlike catheter angiography, multislice CTA not only depicts the vessels but also allows perfusion in adjacent organs to be assessed. To make the most effective diagnostic use of multi-detector row CTA and three-dimensional image post-processing, radiologists must be familiar with the optimal CTA protocols and the typical CT findings in various emergent vascular conditions using computational flow dynamics (CFD). This article describes a technical approach to estimating the blood flow state of human abdominal aortic aneurysms (AAA) in more detail by constructing realistic three-dimensional (3D) vessel models using CFD methods, focusing on pre- and postoperative cases.

Endovascular AAA Repair With the Aortomonoiliac EndoFit Stent-Graft: Two Years' Experience

PURPOSE

To evaluate the feasibility and efficacy of a specific aortomonoiliac endograft and the durability of the femorofemoral bypass for treatment of abdominal aortic aneurysm (AAA).

METHODS

From 2002 to 2004, 39 high-risk (ASA III/IV) patients (36 men; median age 74 years, range 63-84) with AAA (n = 33) or AAA and common iliac artery aneurysm (n = 6) were treated with an EndoFit aortomonoiliac endograft and femorofemoral crossover bypass. The contralateral iliac axis was obstructed with an endoluminal occluder. Patients were followed with contrast-enhanced computed tomography at 1, 6, 12, and 24 months.

RESULTS

EndoFit AMI stent-grafts were implanted successfully in all patients. Perioperative mortality was zero. Endoleak occurred in 3 (7.7%) cases. A proximal type I endoleak was identified at 1 month and was treated with a proximal cuff. Two type II endoleaks are under surveillance because the aneurysm sac shows no enlargement. Thrombosis of the femorofemoral graft occurred in 1 case during the immediate postoperative period due to insufficient inflow from a residual stenosis of the endograft (primary patency 97.5%). The deficit was treated successfully (secondary patency 100%). Two (5.1%) tunnel hematomas were treated conventionally. Median follow-up was 14 months (range 6-30). All patients are alive. None of the aneurysms has ruptured or been converted to an open procedure. Graft migration, serious infection, paraplegia, distal embolization, or any other serious complication has not been observed.

CONCLUSIONS

In high surgical risk patients with complex iliac anatomy, aortomonoiliac endograft with femorofemoral crossover bypass is feasible and efficacious. Moreover, the midterm patency of the extra-anatomic bypass appears quite satisfactory.

Is cross-femoral bypass grafting a disadvantage of aortomonoiliac endovascular aortic aneurysm repair?

PURPOSE

The need for cross-femoral bypass grafting (CFBG) is considered by some to be a major disadvantage of endovascular aneurysm repair (EVAR) with the aortomonoiliac technique. To determine the durability of CFBG in this setting, we examined data from 148 consecutive high-risk patients in a clinical trial of EVAR with a custom-made aortomonoiliac endovascular stent graft.

METHODS

All data were collected prospectively. After hospital discharge, patients were evaluated at 1, 3, and 6 months and annually thereafter. All CFBG was constructed of expandable polytetrafluoroethylene.

RESULTS

During follow-up averaging 23.6 +/- 16.2 months, nine CFBG complications developed in 8 patients (5.4%), including disruption (n = 2), infection (n = 3), thrombosis (n = 2), and pseudoaneurysm (n = 3). Four patients with CFBG complications died, of consequences of infection (n = 2), intracranial hemorrhage during attempted CFBG thrombolysis (n = 1), and intracranial hemorrhage during anticoagulation (n = 1). There were no amputations. At life table analysis, freedom from CFBG complication was 96.3% +/- 1.6% at 12 months, 94.1% +/- 2.2% at 24, 36, and 48 months, and 86.2% +/- 7.8% at 60 months. Overall survival for this high-risk patient group was 83.4% +/- 3.1% at 12 months, 70.4% +/- 4.1% at 24 months, 56.5% +/- 5.3% at 36 months, and 44.8% +/- 6.4% at 48 months.

CONCLUSION

CFBG is durable, with a low rate of complications in patients undergoing aortomonoiliac EVAR. Need for CFBG should not discourage use of aortomonoiliac devices in patients with anatomy unfavorable for other EVAR approaches.

Long-term outcome after aortic endovascular repair: the Sydney experience

BACKGROUND

Since the inception of endovascular aortic aneurysm repair there has been concern about the unknown long-term outcome following this method of repair.

AIM

The purpose of this study is to present the outcome of patients with abdominal aortic aneurysms (AAAs) who were treated by endovascular repair between 5 and 11 years ago.

METHODS

Between May 1992 and November 1997, 190 patients (175 males 15 females, mean age 72 years) were treated at the Royal Prince Alfred Hospital. Overall, 1 of 3 patients were considered to have comorbidities that precluded open repair. Endoprostheses used were first generation in two thirds of patients and second generation in one third of patients.

RESULTS

Eight patients (4.2%) died in the perioperative period. Endovascular repair failed in 20 patients (10.5%) who required conversion to open repair. Secondary conversion at a subsequent operation was necessary in 25 patients with rupture (n = 10), persistent endoleak (n = 11), endotension (n = 2), and inadvertent covering of the renal arteries by their prostheses (n = 2). Eight of the 20 patients presenting with rupture survived conversion to open repair. A long-term study of morphological changes in the proximal neck after endovascular AAA repair revealed a high probability (0.943 at 7 years) of no enlargement. Patients alive with successfully excluded AAA for 5-6, 6-7, 7-8, 8-9 year intervals of time, number 51, 36, 25, and 15, respectively.

CONCLUSION

Considering that one third of patients were unfit for open repair and two thirds were treated with first generation prostheses, these results support the continued use of the endovascular method to treat AAA.

Initial results of endovascular repair of abdominal aortic aneurysms with a self-expanding stent-graft

PURPOSE

This study was performed to evaluate the authors' experience with the endovascular treatment of abdominal aortic aneurysm (AAA) with use of a self-expanding nitinol stent covered with a polyester fabric device and to report the implant's technical features, the immediate results, and the outcome 30 days after device implantation.

MATERIALS AND METHODS

From June 1997 to December 2001, we admitted 169 patients diagnosed with AAA. Of these, 134 were suitable to undergo endovascular repair with use of the Talent stent-graft. In one patient, it was technically impossible to proceed with the implantation procedure. Therefore, a total of 133 patients were treated with use of this technique (78.7%). The average age was 70.7 years (range, 52-88 y). There were 119 men and 14 women. Computed tomographic follow-up was done between the 15th and 30th postoperative days.

RESULTS

The stent-grafts were successfully implanted in all 133 patients. Complications during the procedure included three type-I endoleaks (2.3%) and four iliac artery ruptures (3.0%), which were effectively treated by means of aortic or iliac extension grafts, respectively. The average surgical time was 2.92 hours (from 1.67 h to 7 h). Of the stent-grafts used, 125 were bifurcated (94.0%), two were straight tube grafts (1.5%), and six were conical aortouniiliac grafts (4.5%). Custom-made grafts were used in 62 patients (46.6%) and standard grafts were used in 71 (53.4%). Suprarenal fixation was performed in 117 patients (88%). One female patient developed a serious pulmonary embolism. Eight patients (6.0%) developed serious systemic inflammatory syndrome; two died of disseminated intravascular coagulopathy. There were two additional deaths, one from refractory shock and one suddenly from an unknown cause (total mortality rate, 3.0%). During the postoperative period, 70.3% of the patients developed mild fever (37.6 degrees C-38.9 degrees C). The average length of stay in the intensive care unit was 1.3 days (ranging from 1 d to 12 d) and the total hospitalization time was 4.2 days. Six type-II endoleaks were observed: two were corrected by video laparoscopy-assisted inferior mesenteric artery interruption and the other four were clinically followed up.

CONCLUSIONS

The exclusion of AAA by endovascular techniques with use of the Talent device was possible in the majority of cases with a low incidence of complications. The most common serious postprocedural complication was systemic inflammatory syndrome.

Endovascular repair of wide neck AAA--preliminary report on feasibility and complications

AIM

To assess the feasibility of endovascular repair (EVR) of wide neck abdominal aortic aneurysms (AAA).

STUDY DESIGN

Retrospective.

METHOD

A cohort of patient was identified who had an AAA neck diameter of 28 mm or more and underwent EVR. These patients undergo regular follow-up by 6 monthly CT scan of abdominal aorta. Two independent observers quantified the diameter of the suprarenal aorta, the top of the neck, the bottom of the neck, the length of the neck and the transverse diameter of the AAA.

RESULTS

The study cohort comprised 16 patients. Bland Altman Analysis determined that the 95% interobserver limits of agreement were -4.7 to 3.3 mm. The mean preoperative diameter of the suprarenal aorta, the top of the neck and bottom of the neck all were 31 mm. On the follow-up CT scan on average after 12 months the suprarenal aorta measured 29 mm, the top of the neck 28 mm and the bottom of the neck 30 mm. There was a statistically significant decrease in the size of the top of the neck (p = 0.03).

CONCLUSION

This preliminary report suggests that the endovascular repair of AAA with a wide neck is feasible with available commercial devices. The necks do not appear to increase in size and there is no increased incidence of proximal endoleak.

A multicenter experience with the Talent endovascular graft for the treatment of abdominal aortic aneurysms

OBJECTIVE

The Talent endovascular graft has been used in the treatment of abdominal aortic aneurysms (AAAs) in more than 13,000 patients worldwide. However, information regarding the results of its use has been limited. This report describes the experience with 368 patients with AAAs who underwent treatment at four medical centers as part of an investigator-sponsored investigational device exemption trial.

METHODS

Patients with AAAs were enrolled at four sites during a 32-month period from January 1999 to July 2001. All patients underwent treatment for infrarenal AAA with the Talent endovascular graft. Repair was performed with transrenal stent fixation under epidural (362/368 patients; 98.3%), local (4/368 patients; 1.1%), or general (2/368 patients; 0.5%) anesthesia. The average diameters were: maximum aortic aneurysm, 6.2 +/- 1.2 cm; proximal aortic fixation site, 2.6 +/- 0.4 cm; and distal iliac fixation site, 1.4 +/- 0.6 cm. Bifurcated grafts were used in 276 of 366 patients (75%), aortouniiliac in 57 of 366 patients (16%), and tube aortoaortic in 33 of 366 patients (9%). Multiple comorbid medical conditions were present in all patients (average, 4.7 conditions/patient). The mean age was 75.8 years, and 85% of the patients were male. Follow-up period ranged from 2 to 33 months (mean, 7.3 months).

RESULTS

Endovascular graft deployment was accomplished in 366 of 368 patients. In the 263 patients followed for at least 6 months after endovascular repair, AAA diameter decreased by 5 mm or more in 83 patients (32%); diameter remained unchanged (change < 5 mm) in 157 patients (60%) and increased by 5 mm or more in 23 patients (8.7%). Major morbidity occurred in 46 of 368 patients (12.5%), and minor morbidity occurred in 31 of 368 (8.4%). The 30-day mortality rate was 1.9%. Secondary procedures were performed in 32 patients (8.7%). Late rupture occurred in two patients, and late deaths unrelated to AAA occurred in 32 patients (8.7%) during the follow-up period. The primary technical success rate for all patients was 93.4%. The 30-day primary procedural success rate was 73.3%. The 30-day secondary procedural success rate was significantly higher at 85.8%. Computed tomographic scan was performed within 1 month after surgery in 349 patients. An endoleak was present in 43 of 349 patients (12.3%). These endoleaks were comprised of 10 attachment site (type I; 2.9%), 31 retrograde side-branch (type II; 8.9%), and two transgraft (type III; 0.6%).

CONCLUSION

These midterm findings show a high degree of technical and procedural success achieved in a patient population with extensive comorbid medical illnesses with low perioperative morbidity and mortality rates. Further follow-up study will be necessary to determine the effectiveness of the Talent endograft for the long-term treatment of AAA.

Anaesthesia and endovascular surgery

Anaesthetic requirements for endovascular surgery for aortic, carotid and peripheral vascular disease are reviewed. Peculiarities of the surgery which may impinge on anaesthetic management are discussed together with the pre-operative assessment issues of particular relevance to patients with generalized vascular disease. The detailed anaesthetic management for carotid and aortic endovascular repair is addressed. The lowered peri-operative stress and general morbidity levels which occur with endovascular surgery allow sicker patients with greater risk factors to present for this type of surgery, thus increasing the challenges facing anaesthetists.

Intentional internal iliac artery occlusion to facilitate endovascular repair of aortoiliac aneurysms

PURPOSE

The safety of intentional occlusion of patent internal iliac arteries (IIAs) to facilitate the endovascular repair of aortoiliac artery aneurysms (abdominal aortic aneurysms [AAAs] and iliac aneurysms [IAs]) was evaluated.

METHODS

We analyzed the techniques and clinical sequelae of selective occlusion of one or both IIAs in 103 patients and correlated these findings with the results of preoperative angiograms to identify vascular anatomy that may predict postoperative pelvic ischemia. To quantify the clinical presentation of pelvic ischemia, we developed these criteria: class 0, no symptoms; class I, nonlimiting claudication with exercise; class II, new onset impotence, with or without moderate to severe buttock pain, leading to physical limitation with exercise; class III, buttock rest pain, colonic ischemia, or both. IIA occlusion was achieved in 100% of the patients by means of either catheter-directed embolization or orificial coverage with a stent-graft. No patient in this study had angiographic evidence of significant visceral occlusive disease before the procedure. Sixty-four patients had isolated AAAs, 23 patients had AAAs and IAs, and 16 patients had isolated IAs. Ninety-two patients had one IIA selectively occluded, and 11 patients had both IIAs selectively occluded.

RESULTS

After IIA occlusion, 12 patients were categorized in class I, 9 patients were categorized in class II, and 1 patient was categorized in class III, for a total of 22 patients (21%) with pelvic ischemia. Sixteen (17%) of 92 patients had unilateral IIA occlusions, and six (17%) of 11 patients had bilateral IIA occlusions. Five patients in class I improved and had no symptoms within 1 year, and one patient in class II was downgraded to class I because of improved symptoms. Two unique preoperative angiographic findings were identified in the remaining 16 patients (16%) with chronic pelvic claudication: (1) stenosis of the remaining IIA origin (> 70%) with nonopacification of more than three of the six IIA branches (63%); and (2) small caliber, diseased or absent medial and lateral femoral circumflex arteries ipsilateral to the side of the IIA occlusion (25%). One patient with class III ischemia died of cardiovascular collapse associated with colon infarction caused by either acute ischemia or particulate embolization.

CONCLUSION

The incidence of pelvic ischemia after IIA occlusion is 20% immediately after endovascular aortoiliac aneurysm repair. A total of 25% of patients had no symptoms within 1 year. Two preoperative radiologic findings may help identify patients who are at risk for pelvic ischemia: stenosis of the patent IIA and disease deep femoral ascending branches ipsilateral to the occluded IIA. The risk of colon ischemia appears to be small after selective IIA occlusion to facilitate endovascular AAA repair.

Balloon-expandable common iliac artery occluder device for endovascular aneurysm repair

This study was performed to evaluate the efficacy of a balloon-expandable Palmaz stent common iliac artery occluder device for endovascular stent-graft repair of aortoiliac aneurysms. Eighty-four patients (79 men, 5 women; age range 60-95 yr; mean age, 76 yr) with aortoiliac aneurysms underwent endovascular stent-graft repair. The repair consisted of a stent-graft extending from the abdominal aorta to the iliac or common femoral artery, a cross-femoral bypass graft, and an endovascular arterial occluder device within the contralateral common iliac artery. The occluder device consisted of a 5-cm segment of 6-mm diameter polytetrafluoroethylene (PTFE) graft with a purse-string suture occluding the leading end and a Palmaz stent sutured to the trailing end. The occluder device was delivered through a 17F catheter via an arteriotomy. Eighty-three of the 84 patients received aortic endografts. In one case, infrarenal aortic rupture occurred during deployment of the aortic stent requiring conversion to an open surgical repair. Initial technical success for occluder device insertion was achieved in 78 of the remaining 83 patients. Failure to advance the occluder device delivery sheath through a diseased iliac artery occurred in one patient. Common iliac artery rupture occurred during balloon expansion and occluder device deployment in two patients. Two patients required additional coil embolization of the common iliac artery adjacent to the occluder device at the time of stent-graft insertion to correct incomplete iliac occlusion. Delayed occluder device-related complications included one patient with a postoperative iliac endoleak who required percutaneous coil embolization and one patient with a postoperative iliac endoleak in whom a contained aortic aneurysm rupture developed that was treated by surgical ligation of the common iliac artery. Use of the Palmaz stent-based iliac artery occluder device is an effective technique to induce common iliac artery thrombosis to facilitate endoluminal stent-graft aneurysm repair.

Neurologic injury after endovascular stent-graft and bilateral internal iliac artery embolization for infrarenal abdominal aortic aneurysm

The authors report a rare neurologic complication after the implantation of a bifurcated stent-graft for abdominal aortic aneurysm. The stent-graft was extended to both external iliac arteries after embolization of both internal iliac arteries. The patient subsequently had weakness and numbness of both lower limbs with bowel and bladder incontinence. He probably had ischemic injury to the nerve roots or the lumbosacral plexus, which was related to extensive occlusion of their supplying arteries. The mechanism of spinal cord and neurologic ischemia after aortic stent-graft implantation is discussed.

Accuracy of plastic replica of aortic aneurysm using 3D-CT data for transluminal stent-grafting: experimental and clinical evaluation

PURPOSE

To plan stent-grafting for aortic aneurysms with complicated morphology, we prepared life-sized aortic replicas by laser stereolithography using helical 3D--CT data. The accuracy of the replica was evaluated by measurement of vessel phantoms and clinical 3D--CT data.

METHOD

An imaginary aortic wall was created from helical CT images of the aorta, and a hollow plastic replica was produced by laser stereolithography. The accuracy of the replica was evaluated in five abdominal aortic aneurysms by experimental phantom studies and measurements of the replicas.

RESULTS

The mean difference in measurements between 3D--CT images and model vessels and between 3D--CT images and aortic replicas was 0.2 mm each. Therefore, the difference in measurements between real aortic aneurysms and the replicas was at most 0.4 mm.

CONCLUSION

The accuracy of the replica is satisfactory, making it useful for preoperative evaluation and simulation for stent-grafting.

Endovascular treatment of proximal anastomotic aneurysms after aortic prosthetic reconstruction

PURPOSE

To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudoaneurysms.

METHODS

Three patients with proximal aortic anastomotic pseudoaneurysms 8--15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n = 1), bifurcated graft (n = 1)]. In one patient an uniiliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed.

RESULTS

All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft.

CONCLUSION

Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.

Banding of the common iliac artery: an expedient in endoluminal correction of aortoiliac aneurysms

Dilatation of the common iliac arteries is one of the most frequent causes for exclusion of patients in a series of endovascular correction of abdominal aortic aneurysms (AAAs). In this article we describe the banding technique we use to constrict the large iliac arteries. Four patients underwent endovascular treatment for AAAs with bifurcated grafts. Five of the eight common iliac arteries were 16 to 20 mm in diameter and were constricted around the endoprosthesis by banding with two cotton tapes through a retroperitoneal access. An angioplasty balloon was used as a counterresistance inside the graft. Completion angiogram and postoperative computed tomographic scans showed no endoleak in all cases. No complications occurred in the follow-up (3-10 months). Banding of the common iliac artery is an efficient procedure for endoluminal correction of AAAs when the diameter of the common iliac arteries is greater than 16 mm and less than 20 mm.

Alternative techniques for management of distal anastomoses of aortofemoral and iliofemoral endovascular grafts

PURPOSE

Techniques for managing the distal anastomoses of aortofemoral and iliofemoral endovascular grafts are described.

METHODS

Over a 2(1/2)-year period 46 endovascular grafts were successfully placed to treat severe iliac artery occlusive disease. Endovascular grafts were anchored proximally in the distal aorta or iliac arteries with Palmaz balloon-expandable stents. The distal anastomoses were performed with the use of open, sutured anastomotic techniques. In contrast to stented distal anastomoses, these techniques allowed us to (1) treat occlusive lesions extending from the distal aorta to below the inguinal ligament, (2) terminate endovascular grafts in the groin where stents are contraindicated, (3) vary the distal anastomotic site depending on the local pattern of disease, and (4) standardize the preinsertion length of the endovascular graft.

RESULTS

Two distal perianastomotic stenoses and one graft occlusion were detected postoperatively in 11 bypass grafts that had distal anastomoses sewn endoluminally without an overlying patch angioplasty. Only one perianastomotic stenosis was found among 35 anastomoses performed with other techniques. There were no significant differences in primary and secondary patency between grafts originating in the distal aorta or iliac arteries.

CONCLUSIONS

Hand-sewn distal anastomoses can simplify the insertion of endovascular grafts used for the treatment of aortoiliac occlusive disease. These anastomoses permit tailoring of the graft according to the patients' pattern of disease and eliminate the need to precisely measure the length of the graft preoperatively. In addition, because a distal stent is not required, endovascular grafts can be safely terminated in the groin instead of the external iliac artery where disease progression can lead to graft failure. Finally, endovascular distal anastomoses should be closed with a patch or the hood of a more distal bypass graft to prevent perianastomotic stenoses or occlusions in the postoperative period.

Cost identification of abdominal aortic aneurysm imaging by using time and motion analyses

PURPOSE

To compare the costs of performing helical computed tomographic (CT) angiography with three-dimensional rendering versus intraarterial digital subtraction angiography (DSA) for preoperative imaging of abdominal aortic aneurysms (AAAs).

MATERIALS AND METHODS

A single observer determined the variable direct costs of performing nine intraarterial DSA and 10 CT angiographic examinations in age- and general health-matched patients with AAA by using time and motion analyses. All personnel directly involved in the cases were tracked, and the involvement times were recorded to the nearest minute. All material items used during the procedures were recorded. The cost of labor was determined from personnel reimbursement data, and the cost of materials, from vendor pricing. The variable direct costs of laboratory tests and using the ambulatory treatment unit for postprocedural monitoring, as well as all fixed direct costs, were assessed from hospital accounting records. The total costs were determined for each procedure and compared by using the Student t test and calculating the CIs.

RESULTS

The mean total direct cost of intraarterial DSA (+/- SD) was $1,052 +/- 71, and that of CT angiography was $300 +/- 30, which are significantly different (P < 4.1 x 10(-11)). With 95% confidence, intraarterial DSA cost 3.2-3.7 times more than CT angiography for the assessment of AAA.

CONCLUSION

Assuming equal diagnostic utility and procedure-related morbidity, institutions may have substantial cost savings whenever CT angiography can replace intraarterial DSA for imaging AAAs.

Endovascular repair of abdominal aortic aneurysms: where do we stand?

Endovascular repair of abdominal aortic aneurysms has evolved dramatically within the past few years. In light of the potential to reduce morbidity and mortality associated with open surgical repair, endoluminal grafting offers therapeutic options to patients who are not surgical candidates because of comorbidities. With the development of bifurcated devices, more complex aneurysms may be treated by endovascular grafting. Although successful placement of endovascular grafts requires a pronounced learning curve, including appropriate patient selection, midterm results seem consistent with those of traditional open repair of aneurysms. This review describes the current indications, minimal requirements, different devices and associated techniques, and potential complications of endoluminal repair of abdominal aortic aneurysms. Future aspects of endoluminal grafting are also discussed.