Endoluminal repair of abdominal aortic aneurysms: strengths and weaknesses of various prostheses observed in a 4.5-year experience

Ruptured Suprarenal Abdominal Aortic Pseudoaneurysm with Superior Mesenteric and Celiac Arteries Occlusion, Revealing Behçet's Disease: A Case Report

Behçet’s disease (BD) is a multisystemic, chronic autoimmune inflammatory vasculitic disease with an unknown etiology. Although the literature reports that vascular involvement occurs in 7% to 38% of all BD cases, the arteries are rarely involved; however, arterial involvement is usually associated with significant mortality and morbidity. We report the case of a young female patient who presented to the emergency department with severe abdominal pain and a history of weight loss. The patient was evaluated using computed tomography angiography, which revealed a ruptured suprarenal aortic pseudoaneurysm with occlusion of both the superior mesenteric and celiac arteries. Urgent surgery was performed with aortic repair with an interposition graft and superior mesenteric artery embolectomy. The patient’s clinical history and radiological imaging findings were strongly suggestive of the diagnosis of BD with vascular involvement.

Successful Endoluminal Repair of Arterial Aneurysms by Wallstent Prosthesis and PTFE Graft: Preliminary Results with a New Technique

Purpose:

To describe a new method of endovascular aneurysm exclusion using a Wallstent-PTFE vascular prosthesis in patients at high risk for surgery.

Methods and Results:

Two patients with significant comorbidities refused surgery in favor of endoluminal grafting for treatment of aneurysms in the abdominal aorta and popliteal artery, respectively. Both endovascular procedures were performed percutaneously with local anesthesia using a low-profile customized endograft constructed of thin-walled, predicted polytetrafluoroethylene (PTFE) graft mounted on a Wallstent. In both cases, the aneurysm was excluded from the arterial circulation; there were no postprocedural complications. Follow-up evaluation with appropriate imaging at 8 months (popliteal aneurysm) and 2 months (abdominal aneurysm) revealed no endoleaks.

Conclusions:

Our preliminary results indicate that the Wallstent-PTFE graft, with its smaller diameter and flexible design, offers significant advantages over currently available devices for repair of arterial aneurysms. This method obviates the need for general anesthesia or surgical exposure for arterial repair, which would increase the risk of the procedure in these patients.

Mid-Term Comparison of Bifurcated Modular Endograft Versus Aorto-Uni-Iliac Endograft in Patients with Abdominal Aortic Aneurysm

The aim of this prospective study was to compare the outcome of the Talent bifurcated endograft versus the Endofit aorto-uni-iliac endograft in the short-term and mid-term. Between March 2000 and December 2003, 86 patients were treated with the Talent bifurcated endograft (group A) and 21 with the Endofit aorto-uni-iliac endograft (group B) in the same institute by the same surgical team. All patients followed a prospective protocol of preoperative evaluation and postoperative follow-up. We compared groups A and B in terms of perioperative mortality and morbidity, mid-term endoleak rate, mid-term success rate, and mid-term survival. The perioperative mortality for group A was 1.63%, while that for group B was 0% (P = 0.62). The endoleak rate for group A was 4.65%, and that for group B was 14.29% (P = 0.135). The mid-term success rate was 96.5% for group A and 100% for group B (P = 0.386). There was no significant difference in outcome between the patients treated with the Talent and those treated with the Endofit endoprosthesis. Treating abdominal aortic aneurysms with aorto-uni-iliac endoprosthesis is as safe and effective as treating them with bifurcated endografts.

Systematic Review and Meta-analysis of 12 Years of Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (ER) of abdominal aortic aneurysm (AAA) is a new technique, and reported rates of endoleak, conversion to open repair, rupture and mortality vary widely. The aim of this study was to estimate these rates from the published data, and examine how this has changed as more patients have undergone ER.

METHODS

A systematic review and meta-analysis of publications identified through searches of the electronic databases EMBASE and Medline. All publications quoting endoleak, conversion to open repair, rupture and mortality rates for a series of patients undergoing ER were included.

RESULTS

163 studies pertaining to 28,862 patients undergoing ER were identified as relevant for the review and meta-analysis. The pooled estimate for operative mortality was 3.3% (95% confidence interval 2.9 to 3.6%). The pooled estimate for type 1 endoleaks was 10.5% (95% confidence interval 9.0 to 12.1%), with an annual rate of 8.4% (95% confidence interval 5.7% to 12.2%). The pooled estimate of type 2,3 and 4 endoleaks was 13.7% (95% confidence interval 12.3 to 15.3%), with an annual rate of 10.2% (95% confidence interval 7.4% to 14.1%). The pooled estimate for primary conversion to open repair was 3.8% (95% confidence interval 3.2 to 4.4%), and for secondary conversion to open repair 3.4% (95% confidence interval 2.8 to 4.2%). The pooled estimate for post-operative rupture was 1.3% (95% confidence interval 1.1 to 1.7%), with an annual rupture rate of 0.6% (95% confidence interval 0.5% to 0.8%). Multivariate meta-regression analysis showed that rates of operative mortality, post-operative rupture and total number of endoleaks all fell significantly (p<0.05) over time.

CONCLUSIONS

This study demonstrates a low mortality and a gradual reduction in vascular morbidity and mortality associated with endovascular repair since it was first introduced.

Endovascular Treatment of a Thoracic Aortic Pseudoaneurysm After Previous Open Repair

The use of endovascular stents to treat descending thoracic aortic pathologies is emerging as a less invasive therapy to treat high-risk patients. This case report describes the presentation of a patient with a pulsatile mass on her back. The patient's computed tomographic scan revealed the mass to be an extension of a large psuedoaneurysm from the site of a previous repair of her thoracic aorta for a dissecting aneurysm several years earlier. The psuedoaneurysm was successfully treated with an endovascular stent and the patient was discharged home on postoperative day 5.

Risk-Adjusted Outcome Analysis of Endovascular Abdominal Aortic Aneurysm Repair in a Large Population:How Do Stent-Grafts Compare?

PURPOSE

To compare differences in the applicability and incidence of postoperative adverse events among stent-grafts used for repair of infrarenal aortic aneurysms.

METHODS

An analysis of 6787 patients from the EUROSTAR Registry database was conducted to compare aneurysm morphological features, patient characteristics, and postoperative events for the AneuRx, EVT/Ancure, Excluder, Stentor, Talent, and Zenith devices versus the Vanguard device (control) and each other. Annual incidence rates of complications were determined, and risks were compared using the Cox proportional hazards analysis.

RESULTS

The annual incidence rates were: device-related endoleak (types I and III) 6% (range 4%-10%), type II endoleak 5% (range 0.3%-11%), migration 3% (range 0.5%-5%), kinking 2% (range 1%-5%), occlusion 3% (range 1%-5%), rupture 0.5% (range 0%-1%), and all-cause mortality 7% (range 5%-8%). After adjustment for factors influencing outcome, AneuRx, Excluder, Talent, and Zenith devices were associated with a lower risk of migration, kinking, occlusion, and secondary intervention compared to the Vanguard device. Significant increased risk for conversion (EVT/Ancure) and reduced risk of aneurysm rupture (AneuRx and Zenith) and all-cause mortality (Excluder) were found compared to the Vanguard device.

CONCLUSIONS

Significant differences exist between stent-grafts of different labels in terms of applicability and complications during intermediate to long-term follow-up. Since each stent-graft has its drawbacks, no single label can be identified as the best. It is reassuring that developments in stent-grafts indeed result in better performance than the early stent-grafts. However, a single device incorporating all the perceived improvements should still be pursued.

Superiority of endovascular grafts compared to bare metal stents with transstent coil embolization for endovascular abdominal aortic aneurysm repair in patients at high risk for surgery

We sought to determine the effectiveness of uncovered stents with aneurysm transstent coil embolization compared with endografts for percutaneous abdominal aortic aneurysm (AAA) repair. Thirty-six patients with AAA considered inoperable underwent endovascular repair using the Ancure bifurcated endograft or overlapping uncovered stents with transstent coil embolization. Procedural success, outcomes, serial aneurysm size, aneurysm blood flow, and growth ratios were compared between groups. One patient in each group died due to the procedure and two patients in the endograft cohort required acute surgical repair. After 2.0 +/- 0.8 years of follow-up, three patients required endograft placement, four surgical repair, three had AAA rupture, with two AAA-related deaths in the uncovered stent group. No late deaths or surgical conversion occurred in the endograft group. The primary AAA flow exclusion and aneurysm expansion rate and growth were superior in the endograft group and during follow-up. In high-risk patients with AAA, the use of endografts was superior compared to uncovered stents with transstent coil embolization for endovascular repair.

Health-Related Quality of Life Outcomes Following Elective Open or Endovascular AAA Repair:A Randomized Controlled Trial

PURPOSE

To assess health-related quality of life outcomes after endovascular versus open abdominal aortic aneurysm repair.

METHODS

Participants were randomly assigned to receive either endovascular or open abdominal aortic aneurysm (AAA) surgery according to a rate of 3 endovascular patients to 1 with open repair. Data on patient characteristics, operative aspects, and procedural and device-related complications were compiled at a single center. Health-related quality of life was assessed before treatment and 1 and 3 months following operation using the Medical Outcomes Study Short-Form 36-item Health Survey (SF-36) and the EuroQol questionnaire.

RESULTS

Between 1996 and 1999, 57 patients (54 men; mean age 69 years, range 52-82) underwent endovascular and 19 patients (16 men; mean age 68 years, range 52-81) underwent open AAA repairs. Preoperatively, comparable scores were recorded in both treatment groups. One month after operation, patients of both groups scored significantly lower on the SF-36 domains of Role Limitations due to physical problems and Pain compared to preoperative scores. Three months after operation, both groups had scores in all domains comparable to preoperative levels of functioning. There was a significant benefit for the endovascular group 1 month after operation in the SF-36 domains of Physical Functioning, Role Limitations due to physical problems, Vitality, and Pain; their score on the EuroQol Usual Activities item was also significantly better. After 3 months, there were no longer differences between groups.

CONCLUSIONS

Short-term health-related quality of life benefits were found after endovascular repair compared with standard open surgery.

Technical success from endovascular aneurysm repair in the post-marketing era: a multicenter prospective trial

Evaluation of post-marketing success with the Ancure Endovascular Graft (AEG) was accomplished by review of a multicenter, prospective trial involving 46 centers and 163 patients. A second cohort of patients (n = 350) treated with the AEG under a controlled-use interval prior to the prospective trial was simultaneously evaluated. Technical success in both groups of patients (96.9% and 97.4%, respectively) was similar to what was reported in pre-market clinical trials. Operative implantation complications unique to the AEG included graft limb stenosis/occlusion in 35.6 and 31.4%, contralateral pull wire being caught on hooks in 33.7 and 28%, failure to seal (type I endoleak) in 17.2 and 18.3%, jacket guard being stuck in 12.9 and 11%, contralateral wire being stuck in 6.8 and 7.1%, high jacket retraction force in 16 and 8.5%, and inability to retract jacket in 1.8 and 0.5% of patients involved in the multicenter trial and controlled-use interval, respectively. One of four patients undergoing conversion in the prospective trial had graft misdeployment as a mode of failure. Three were converted for access failure. The 30-day mortality rate in the prospective trial was 3.7%. Interventions to resolve implantation-related events included stenting, guide catheter manipulations, wire exchanges, and delivery catheter disassembly. These interventions were successful in virtually every case. Open surgical procedures were not needed to correct these operative problems. Results from this study demonstrate excellent technical success with the AEG in the post-market era. Interventions to resolve implantation complications, when utilized, are highly successful in facilitating AEG implantation and providing technical success.

Emergency endovascular interventions for ruptured thoracic and abdominal aortic aneurysms

BACKGROUND

The purpose of our study was to show the effectiveness of endovascular stent grafts in the treatment of acutely ruptured abdominal and thoracic aortic aneurysms as an alternative to the conventional surgical approach in an emergency setting.

METHODS

From October 1996 to October 1998 we deployed 9 emergent endovascular stent grafts--6 in the abdominal aorta and 3 in the thoracic aorta. Aortic rupture was confirmed before surgery with spiral-computed tomographic scan. The average interval from onset of symptoms to treatment was 4.5 hours. We used commercially manufactured stent grafts: 4 Corvita (Corvita Inc/Schneider Corp/Boston Scientific Corp, Natick, Mass), 3 Talent (World Medical Inc, Surise, Fla/Medtronic, Sunnyvale, Calif), and 2 Vanguard (Boston Scientific Corp, Natick, Mass).

RESULTS

Deployment of the stent grafts was successful in all cases. Two patients died in the follow-up period (120 months) from myocardial infarction. No cases were seen of paraplegia or stent migration. However, 2 endoleaks, 1 in-stent stenosis, 1 temporary renal failure, and 1 brief episode of myocardial ischemia occurred.

CONCLUSION

Our experiences with emergency endovascular stent grafting show that the procedure is technically feasible, with less morbidity and mortality than conventional open surgery, in selected patients.

Endovascular treatment of huge saccular abdominal aortic aneurysm in a young Behcet patient: mid-term result

BACKGROUND: Abdominal aortic aneurysm formation is among the arterial complications of Behcet's disease. Weakness and fragility of aortic walls leads to the development of arterial complications like pseudoaneurysms. CASE PRESENTATION: A case of huge saccular abdominal aortic aneurysm in a young Behcet patient who was successfully treated with endovascular stent graft placement is reported, diagnostic and interventional procedures are discussed, and mid-term follow-up results are presented. CONCLUSIONS: Endovascular treatment of abdominal aortic aneurysm complications of young Behcet patients who are not suitable for open surgery and need intervention could be an alternative treatment modality even without performing preprocedural angiography.

Bare metal stents with or without coil embolization for abdominal aortic aneurysm exclusion in high-risk patients

The objective of the study was to determine if uncovered self-expanding metallic stents with or without polyester-covered coils can exclude abdominal aortic aneurysms (AAA). Exclusion using uncovered metal stents with or without coils has been shown to be successful in the animal model. Twelve patients underwent aneurysmal therapy with uncovered self-expanding metallic stents and polyester covered metallic coils (male, 8; female, 4; mean age, 74 +/- 8 years) because no other therapeutic alternative was available. Indications were severe aorto-iliac disease, presumptively high surgical risk due to comorbidities, a previously failed endograft attempt, and a hostile abdomen as a result of prior surgeries. Under local anesthesia, stents were introduced percutaneously via 10 or 11 Fr sheaths into the femoral artery and deployed in an overlapping fashion to cover the length of the AAA. All endoluminal procedures were successful, and no major complications were encountered. The average hospital stay was 33 +/- 21 hr. At a mean follow-up of 18 +/- 13 months, there was no rupture, leak, or evidence of aneurysm expansion in any of the patients. There was one mortality that was not AAA-related. The remaining patients had no aneurysm-related symptoms. Endoluminal exclusion of an AAA using self-expanding bare metal stents with or without coil embolization may be a viable treatment option for patients who cannot undergo standard surgical or endovascular repair. However, these data do not demonstrate that this methodology actually precludes rupture since the cohort is of small size. Cathet Cardiovasc Intervent 2001;54:12-18.

Three year single centre experience with the AneuRx aortic stent graft

OBJECTIVES

To report the mid-term single-centre experience with the AneuRx self-expandable nitinol stentgraft for endovascular aneurysm repair.

PATIENTS AND METHODS

Between December 1996 and January 2000 a total of 128 patients were treated with an AneuRx bifurcated stentgraft. Of these, 77 patients had a minimum follow-up of 12 months. Patient operative and follow-up data were prospectively gathered.

RESULTS

Two (3%) conversions were necessary. Median hospital stay was 3 days. One superficial wound infection occurred. Periprocedural (30 days) mortality was 5% (four patients). Three graft occlusions were noted of which two required treatment. Fifteen patients developed 18 endoleaks (six type 1, eight type 2 and four type 3). Type 1 and type 3 endoleaks were treated by extension cuffs. Four type 2 endoleaks were treated with embolisation or direct lumbar puncture. Two-year freedom from endoleak was 76%. Graft migration occurred in six cases, resulting in a 2-year freedom from migration of 90%, kinking only once.

CONCLUSIONS

endovascular AAA treatment is feasible and so far mid-term results are without major problems. Extensive follow-up is essential as secondary problems may occur later. Long-term results are to be awaited.

Impact of endovascular repair for abdominal aortic aneurysms in octogenarians

A total of 50 consecutive patients (86% male; median age, 82 years) underwent endovascular repair of abdominal aortic aneurysms (AAAs) ranging from 4.0 to 9.0 cm (median, 5.2 cm). Efficacy of aneurysm exclusion was assessed by angiography, duplex scan, and/or contrast-enhanced computed tomography (CT). Acute technical success was 82%. Access failed in one patient, and immediate conversion to open operation was required in two patients. Improper deployment of the endoluminal graft (ELG) across the renal arteries occurred in one patient. The median operation time, estimated blood loss, packed red blood cells received, contrast volume, and length of intensive care and hospital stay were 128 min, 200 mL, 0.1 unit, 297 mL, 0.9 days, and 3 days, respectively. ELG limb thrombosis was seen in one patient. There were 4 (8%) early endoleaks, and 2 endoleaks were discovered in other patients at 3 and 6 months. Local/vascular and remote/systemic postoperative complications were seen in 13 (26%) and 9 (18%) patients, respectively. At a median follow-up of 11 months (range 2 to 36 months), clinical success was 78%. The aneurysm sac diameter (n = 49) decreased from a preoperative median of 5.2 to 4.7 cm (p = 0.0001). Technical success was high, and results at 11 months were satisfactory. Long-term outcomes require further study.

Management of cholelithiasis in combination with cardiovascular surgery

A retrospective review of the perioperative management of patients with cardiovascular surgical disorders and cholelithiasis was conducted, and the surgical strategies employed are discussed. Between 1988 and 1998, 18 patients having cardiovascular surgical disorders underwent cholecystectomy. These patients were divided into three groups: group I, given a one-stage operation (n = 9); group II, given a two-stage operation (n = 3); and group III, given cholecystectomy during follow-up after cardiovascular surgery (n = 6). In group I, a median laparotomy was adopted for patients with an abdominal aortic aneurysm (AAA) to allow both disorders to be treated through the same incision, whereas a right subcostal approach was employed to separate the incisions for patients who underwent cardiac operations. In group II, one patient underwent cholecystectomy before cardiac surgery, and two patients underwent cholecystectomy for postoperative cholecystitis after cardiovascular operations. One patient from group II and all from group III were on preoperative anticoagulant therapy, two of whom underwent laparoscopic cholecystectomy. No fatal complications such as prosthetic infection, intraperitoneal hemorrhage, or cerebral attack were encountered. In conclusion, we consider that performing cholecystectomy during AAA repair may be safe and prevents the risk of postoperative cholecystitis; it is preferable to treat cholelithiasis coexisting with cardiac disorders concomitantly with or before cardiac operations; and laparoscopic cholecystectomy can be safely performed under anticoagulant therapy.

Adverse outcome following transfemoral endovascular stent-graft repair of an abdominal aortic aneurysm in a patient with severe liver dysfunction: report of a case

We describe herein the case of a patient with severe liver failure in whom an abdominal aortic aneurysm (AAA) extending to the right iliac artery was diagnosed. Because the risk of performing a standard open repair was considered too high in this patient, the aneurysm was uneventfully repaired using a technique of transfemoral endovascular stent-grafting with femorofemoral bypass and occlusion of the left common and right internal iliac arteries. Unfortunately, multiorgan failure associated with adult respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC) suddenly developed on postoperative day (POD) 2 and the patient died on POD 9. Thus, although endovascular stent-grafting is generally assumed to be less invasive and therefore feasible for high-risk patients, patients with severe liver dysfunction may not be suitable candidates.

Endograft treatment of anastomotic aneurysms following conventional open surgery for infrarenal aortic aneurysms

OBJECTIVE

to evaluate the use of endograft therapy for treating anastomotic aneurysm following open surgical repair of infrarenal aneurysms of the abdominal aorta.

METHODS

four male patients (age 47-75 years) at high surgical risk (ASA IV n=3, ASA III n=1) developed secondary aneurysms at the site of the central (four aneurysms) and additional peripheral (two aneurysms) anastomosis of their tube or bifurcation prosthesis an average of 13 years (range 1-23 years) after conventional open surgical correction of infrarenal aneurysm of the abdominal aorta. In two patients, there was covered rupture of the aneurysm sac. The aneurysm diameter was 4.8 cm, 8.0 cm, 7.4 cm, 7.0 cm, respectively (mean 6.8 cm). Follow-up included helical CT imaging at 1 week, 3 months and 6 months postoperatively.

RESULTS

anastomotic aneurysm was successfully treated in all four cases. No evidence of endoleak was observed during the follow-up period. Two patients died 14 and 18 days after surgery due to myocardial infarction and cerebrovascular accident. The endovascular repair of the two patients who died was intact.

CONCLUSION

although no long-term results are available, the use of a graft-in-graft method to repair anastomotic aneurysms following conventional implantation of tube or bifurcation prostheses appears to be effective, particularly in patients at high surgical risk.

Endovascular repair of aortic allograft aneurysmal degeneration: a case report

Aortoenteric graft fistula remains a dreadful complication of aortic surgery. Good results have been reported using in situ graft replacement with arterial allografts. Late aneurysmal degeneration of the graft itself may necessitate further repair. We report the case of such an aneurysmal degeneration 7 years after implantation of the allograft. Endovascular repair was performed with a Vanguard device; complete exclusion was obtained immediately. At 6-month follow-up, the patient was alive and well. Duplex and computed tomography scans showed an excluded aneurysm with a slight reduction in size. Endovascular stent grafting may be a therapeutic option for treating patients with late allograft degeneration.

The value of intraoperative intravascular ultrasound for determining stent graft size (excluding abdominal aortic aneurysm) with a modular system

Since the introduction of endovascular stent grafts at our institution we have used intraoperative intravascular ultrasound (IVUS) to definitively determine stent graft size. In this study, expected stent graft size, based on preoperative helical CT scan measurements, was compared with the actual final size, based on intraoperative IVUS measurements. Between December 1996 and January 1998, 54 patients were treated with an AneuRxTM bifurcated stent graft. Preoperatively all patients underwent angiography and helical CT scanning. Expected stent graft size was determined according to these measurements. The final stent graft size was based on IVUS measurements acquired during the procedure. Differences in expected and final size were compared and follow-up endoleaks were also noted. Differences in diameter measurements between CT and IVUS were compared using the paired Student's t-test. Differences in expected and chosen stent graft length were compared using the McNemar's test for paired proportions of binomial outcomes. Our results showed that helical CT scanning overestimates diameter and underestimates length. This underestimation of length is explained by the tortuosity of the aorta and iliac arteries while using axial slices of the CT scan. The last-minute corrections based on the intraoperative IVUS measurements did not result in a high incidence of endoleaks at fixation zones. In our opinion, the possibility of making final corrections in the choice of diameter or length of the stent graft is the additional value of intraoperative IVUS.

Anatomical importance of infrarenal aortic branches in conventional and endovascular surgery: a review

Minimally invasive or catheter-directed, endoluminal stent-graft treatment of abdominal aortic aneurysms (AAA) is a novel and important advance in the armamentarium of the vascular surgeon and interventional therapist. Provided adequate training is available, infrastructure is optimal, and patient selection correct, successful exclusion of AAA can safely and effectively be achieved with low morbidity and mortality by this lesser invasive technique. An important Achilles heel of endovascular repair (EVR) of AAA is back bleeding or endoleak formation due to incomplete sealing or bridging of aortic branches ostia by endoluminal stents. Significant, recurrent, and persistent retroleaks, a topic of clinical interest, are related to either incompletely sealed-off inferior mesenteric and/or lumbar arteries. The optimal method to diagnose and manage these endoleaks is currently in a state of evolution. In the process of stent-graft treatment of AAA, other important aortic branches are also bridged that may potentially present with the sequelae of peripheral ischemia. This review re-emphasizes the anatomical and clinical importance of abdominal aortic branches relevant to conventional aortic surgery and EVR of AAA.

Endovascular healing is inadequate for fixation of Dacron stent-grafts in human aortoiliac vessels

BACKGROUND

migration and kinking of stent-grafts can occur late after endovascular aneurysm repair. It is unknown if endovascular grafts incorporate enough to be permanently anchored. In this report, healing of aortic stent-grafts was assessed in humans.

PATIENTS AND METHODS

we retrieved 23 Dacron stent-grafts from patients treated for an aortic aneurysm since 1993. Twelve stent-grafts were explanted at late conversion to open repair and 11 at autopsy. The deaths were unrelated to graft fixation. The median age of the patients was 74 years (IQR 55-84 years) and the grafts were explanted 9 months (1-31 months) after insertion. Microscopic slides were prepared by conventional techniques or by cutting and grinding arterial specimens embedded in plastic with the stent-grafts in situ.

RESULTS

the stent-grafts detached readily from the native arteries at surgery or autopsy, except when the stents had hooks or barbs which engaged the vessel wall. A space filled with poorly organised blood components persisted between the graft and the aortic wall 2.5 years after implantation. No firm incorporation of the grafts was observed proximally in the aneurysm neck or distally in the iliac segment. A friable neo-intimal layer covered parts of the luminal aspect of the grafts.

CONCLUSIONS

endovascular healing provides poor fixation of Dacron stent-grafts in humans. At present, fixation relies on the mechanical properties of the stent-grafts.

Mid-term fixation stability of the EndoVascular Technologies endograft. EVT Investigators

AIM OF THE STUDY

to determine the positional stability of the EndoVascular Technologies (EVT) endograft after endovascular aneurysm repair during morphologic changes of the abdominal aorta during follow-up.

PATIENTS AND METHODS

all patients treated worldwide with an EVT endograft with an adequate postoperative and at least 12 months postoperative CT scan were included (n=125). Endograft migration was investigated by recording the position of the endograft attachment systems relative to the renal arteries and the aortic or iliac bifurcations. The vertical body axis served as a scale to quantify migration. Aortic cross-sectional areas were measured in the suprarenal aorta and in the proximal and distal aneurysm necks. Length changes of the infrarenal aorta during follow-up were measured, comparing the distance between the left renal artery and the aortic bifurcation.

RESULTS

the median follow-up was 24 months (range 12-48 months). Graft migration was identified in 4 out of 125 patients (3%). Significant infrarenal aortic dilation was observed at the proximal and distal aneurysm neck during follow-up. However, aortic neck dilation was not associated with endograft migration. The length of the infrarenal aorta did not change significantly after endovascular repair.

CONCLUSION

fixation by stents containing hooks of the EVT design appear to be effective in preventing migration of endografts with an unsupported trunk for up to four years. A stable position was maintained in spite of changes in cross-sectional areas of the aneurysm neck.

Transcatheter, Endovascular Repair of Abdominal Aortic Aneurysm: Feasibility, Noninvasive Diagnosis, Problems, and Follow-Up

Until recently, the repair of an abdominal aortic aneurysm (AAA) required major surgery. Recently, the transcatheter technique has allowed minimally invasive endovascular stenting of infrarenal AAAs. This procedure is less traumatic and is associated with a shorter hospital stay than conservative surgery. With the stent placement, the effective aortic lumen diameter decreases and the aneurysmal space is excluded from the circulation. Ultrasonographic studies have allowed imaging of the abdominal aorta, its main branches, and the endovascular stent. The aortic blood flow after the repair is ideally limited to the stent lumen. Follow-up studies have permitted reevaluation of the aorta and the stent, with special emphasis on the aortic expansion and blood flow within the excluded space. These studies have correlated well with other imaging techniques such as intravascular ultrasound, computed tomography scanning, and aortography.

Aortoduodenal fistula: a late complication of intraluminal exclusion of an infrarenal aortic aneurysm

During recent years, considerable clinical experience has been gained with endoluminal stent-graft procedures. Several studies have shown promising results up to a period of 4.5 years. However, long-term follow-up studies are still limited. Late endoleaks caused by stent-graft migration, disconnection of single components in modular stent-grafts, and limb thrombosis have been observed as long-term complications. We report a case in which a migrated and kinked bifurcated stent-graft caused an aortoduodenal fistula 20 months after stent-graft insertion. To our knowledge, such a complication has not been reported before.

Endovascular abdominal aortic aneurysm repair with percutaneous transfemoral prostheses deployment under local anaesthesia. Initial experience with a new, simple-to-use tubular and bifurcated device in the first 27 cases

BACKGROUND

Modification of endografts are required to simplify and improve the safety of the endovascular management of abdominal aortic aneurysms (AAA).

OBJECTIVES

The aim of this study is to evaluate the efficacy of a new custom-made, tubular and bifurcated device.

MATERIALS AND METHODS

The graft consisted of a continuous, self-expanding, stainless steel, Z-stent structure, covered with a thin wall PTFE tube. Bifurcated grafts were constructed in vivo from three PTFE tubes with a continuous Z-stent structure. Twenty-seven high risk patients with a mean age of 74 (62-86) years and AAA, mean diameter 5.9 cm, were treated in the last 26 months. Tube grafts were deployed in 13 aortic and one iliac cases, bifurcated grafts in nine cases and aorto-uni-iliac grafts with femorofemoral bypass in four cases. Grafts were deployed percutaneously under local anaesthesia. Patients were followed with contrast CT periodically.

RESULTS

All grafts were deployed. There were no open conversions or other major complications. There were nine proximal and one distal postoperative endoleak. Four sealed spontaneously, three were treated successfully with endovascular techniques and three are under surveillance. In the 7 (2-23) months follow-up, one patient died due to heart failure 3 months post-procedure.

CONCLUSIONS

Local anaesthesia and percutaneous graft introduction simplify and improve the efficacy of the procedure. Continuous aortic graft support provides stability and reduces the risk of migration. PTFE is a flexible, low-profile material for use in endovascular stent-grafts. The bifurcation concept used offers a simple technique for bifurcated grafts.

Endoluminal treatment of infrarenal aortic aneurysms: clinical experience with the Talent stent-graft system

PURPOSE

To evaluate the safety and efficacy of the Talent stent-graft (TSG) system in the endoluminal treatment of infrarenal abdominal aortic aneurysms (AAAs).

PATIENTS AND METHODS

Endoluminal treatment of an AAA was attempted in 30 men with a mean age of 70.5 years (range, 51-83 years). Seven patients had AAAs suitable for treatment with a tube graft. In the other patients, treatment with a bifurcated TSG was planned. All procedures were performed as a combined surgical-radiologic procedure in an angiographic room.

RESULTS

Primary technical success was achieved in 25 of 30 patients (83%). Technical failures were due to misplacement of the TSG (n = 2) with proximal leakage as a consequence, inability to gain access via the iliac arteries (n = 1), and a distal leakage (n = 2). Secondary interventions (n = 2) and spontaneous thrombosis of a distal leak (n = 1) increased the secondary technical success rate to 93% (28 of 30). Two procedures were converted to open surgery (conversion rate = 6%). One patient died during the first 30 days after uncomplicated stent-graft insertion because of myocardial infarction (30-day mortality = 5%). No complications occurred during a mean follow-up of 15.4 months (range, 6-19 months). The maximum diameter of the AAA decreased in eight patients and remained unchanged in the remaining patients. No increase in diameter was observed. No late endoleak or migration of the TSG was observed.

CONCLUSION

The TSG-system revealed satisfactory initial and early follow-up results. Treatment of AAAs with this stent-graft system is feasible. The technical success rate in carefully selected patients should be 90% or more. However, long-term observations are necessary to determine if the encouraging early results of this type of therapy can be preserved during long-term follow-up.

Time-related alterations in shape, position, and structure of self-expanding, modular aortic stent-grafts: a 4-year single-center follow-up

PURPOSE

To report the nature and ramifications of structural and positional changes over time in tube and modular bifurcated aortic stent-grafts.

METHODS

Two hundred ninety-one patients received endovascular aortic grafts (primarily Stentor/Vanguard) between August 1994 and August 1998. Follow-up surveillance (clinical and laboratory examination, biplanar noncontrast radiography, and contrast-enhanced computed tomography) has been maintained on all patients for 4 years. Changes in the configuration and position of endografts have been noted and their sequelae charted.

RESULTS

Three types of endograft shape changes have been documented: mild -- slight distortions visible on plain radiographs (n = 90, 31.0%), significant -- angulations reaching 60 degrees to 90 degrees (n = 65, 22.3%), and severe -- angulations > or = 90 degrees (n = 10, 3.4%). Changes in position never gave rise to late migration at the proximal attachment site, whereas at the distal ends, the endograft easily retracted from the iliac arteries (n = 8). Structural alterations (rupture of the stent frame, sutures, or fabric, and total graft disintegration) were more common in the original Stentor model. Shape, position, and structural alterations were mutually dependent and led to secondary endoleaks (n = 26) and graft limb thrombosis (n = 37). Late surgical conversion was necessary in 3 (1.0%) patients.

CONCLUSIONS

Tortuosity of the native vessels is a source of complication in long-term follow-up just as it is during implantation. Given the late appearance of complications in this patient cohort, it would seem that the durability of an endograft cannot be evaluated with < 3 years of follow-up.

Adverse events after endoluminal repair of abdominal aortic aneurysms: a comparison during two successive periods of time

PURPOSE

The aim of this study was to document the incidence rate of adverse events after endoluminal repair of abdominal aortic aneurysms (AAAs) during two successive periods of time.

METHODS

One hundred ninety patients (175 men, 15 women; mean age, 72 years) underwent endoluminal repair of AAAs in a 5(1/2)-year period. Adverse events were documented prospectively for all the patients throughout this interval. An adverse event was defined as any of the following events: a death within 30 days, a conversion to open repair, the need for further intervention (either open or endovascular), the need for hemodialysis, a failure to cure the AAA, and wound complications. The patients were divided into two groups those who underwent operation in the initial 3-year period (group I; n = 75) and those who underwent operation in the subsequent 2(1/2)-year period (group II; n = 115). The results were analyzed for total adverse events for both periods of time and for difference in incidence rates within categories of adverse events between the two groups.

RESULTS

Eight patients (4.2%) died in the perioperative period. The endoluminal repair failed in 17 patients (8.9%), which necessitated a primary conversion to open repair at the original operation. In 88 patients, 110 adverse events occurred. There was no significant difference in the incidence rates of adverse events in patients in group I (37/75) and group II (51/115). Apart from primary conversion (P =.007), there was no significant difference in the incidence rates of adverse events between group I and group II within the following categories: perioperative (within 30 days) deaths, primary conversion, secondary conversion, supplementary endoluminal repair, intervention for lower limb ischemia, hemodialysis necessitated, failure to cure the AAA as a result of persistent endoleak, and wound complications.

CONCLUSION

Despite improvements in technology and increasing experience, adverse events continue to occur in a relatively high proportion of patients (45%) who undergo endoluminal repair of AAA. Reporting the incidence rates of adverse events provides a more accurate picture of the morbidity rates of the endoluminal method rather than simply listing the procedures as successes or failures. The similarity in the incidence rates of adverse events in patients in group I and group II suggests that there are inherent risks in the endoluminal method rather than iatrogenic complications that occur during the learning curve with a new technique.

Endovascular grafting for abdominal aortic aneurysms

Despite the initial success of endovascular grafts in a very difficult patient population, many problems remain. These procedures are often time-consuming and quite complicated, requiring the close cooperation of an experienced team of vascular surgeons and interventional radiologists. Access may be difficult through occluded, stenotic, and tortuous vessels. Inadequate graft deployment may result in arterial rupture or graft migration, which could potentially lead to acute occlusion of the renal or iliac arteries. Occlusion of the inferior mesenteric artery may result in ischemic colitis. Also, endovascular grafts may fail to exclude an aneurysm from systemic arterial blood pressure, not protecting the patient against impending rupture, and embolization and thrombosis are ever-present dangers. Concerns have been raised regarding radiation exposure and intravenous contrast loads used during these procedures. Clearly, more experience must be gained and technologic advancements made before the use of these devices becomes commonplace, something that may not be too far off in the future.

Aortoenteric fistula caused by a ruptured stent-graft: a case report

PURPOSE

To report a case of aortoenteric fistula secondary to endovascular abdominal aortic aneurysm (AAA) exclusion using the Stentor bifurcated endovascular graft.

METHODS AND RESULTS

Seventeen months after a successful endovascular AAA procedure, a male patient developed upper gastrointestinal bleeding. An aortoenteric fistula was diagnosed. At operation, the endograft fabric was found to be ruptured in an area of suture disruption between the nitinol stents. Coincidentally, a pre-existing inflammatory process might have caused adhesions between the bowel and the aortic wall, predisposing to fistula formation. The patient recovered after placement of a conventional aortic graft.

CONCLUSIONS

Suture disruption between the internal support stents is a recognized complication in the first-generation Stentor device. Although the case described here is probably not typical of the consequences of this sequela, it does reinforce the need for continual periodic imaging to check for signs of graft disruption in Stentor endografts.

Rupture of abdominal aortic aneurysm previously treated by endovascular stentgraft

We describe a case of abdominal aortic aneurysm (AAA) with rupture 16 months after treatment by an endograft. A 76-year-old patient on Coumadin after aortic valve replacement had initially successful exclusion by stentgraft. There was no evidence of an endoleak seven months after stentgraft repair, although a computed tomography scan detected an enlargement of the aneurysm sac. Sixteen months after initial endograft surgery, rupture of the aneurysm occurred and we performed open emergency surgery. We treated the aneurysm by conventional technique, and the patient survived the rupture. This case emphasized the fact that patients after endograft AAA repair require a close follow-up. An expansion of the aneurysm sac after the procedure should signal failed exclusion, even if a computed tomography scan does not demonstrate an endoleak. Anticoagulation can be an important factor in failure after endoluminal graft treatment. Supravisceral aortic cross clamping is helpful in dealing with a stented aorta.

Transluminal stent-graft repair for pseudoaneurysm of PTFE hemodialysis grafts

PURPOSE

To report the use of endovascular techniques to treat two cases of nonanastomotic pseudoaneurysm of a bridge graft fistula (BGF).

METHODS AND RESULTS

Two men with fully functional polytetrafluoroethylene (PTFE) BGFs both presented with an enlarging mass adjacent to their arteriovenous shunt. The false aneurysm in both instances was located by ultrasound and confirmed by shunt angiography at the time of surgery. Both fistulas were repaired by transluminally introducing a stented graft composed of a balloon-expandable Palmaz stent covered with a PTFE graft. Completion arteriography confirmed normal flow through the graft with no communication between the lumen and the aneurysmal cavity. Both patients recovered without complications and were discharged on the day of the procedure. Follow-up data reveal that both fistulas remain fully functional up to 5 and 6 months, respectively.

CONCLUSIONS

Endovascular repair using stent-grafts can be a safe and effective method of excluding pseudoaneurysms associated with PTFE BGFs.

Reduced pulsatile wall motion of abdominal aortic aneurysms after endovascular repair

PURPOSE

The reduced size of abdominal aortic aneurysms (AAAs) after endovascular repair suggests lowered intraaneurysmal pressure. In the presence of endoleaks, the size is not decreased. Although postoperative intraaneurysmal pressure is difficult to record, the pulsatile wall motion (PWM) of aneurysms can be measured noninvasively. The aim of this study was to assess the PWM of AAAs before and after endovascular repair and to relate the change in the PWM to aneurysmal size and presence of endoleaks.

METHODS

Forty-seven patients underwent endovascular repair of an AAA. The aneurysm diameter and PWM were measured with the use of ultrasonic echo-tracking scans preoperatively; at 1, 3, and 6 months; and thereafter biannually. Fifteen aneurysms developed endoleaks, whereas 32 were completely excluded. The leaks were characterized with the use of computed tomographic scanning and angiography. Median follow-up was 12 months (interquartile range, 5 to 24 months).

RESULTS

The preoperative PWM of the aneurysms was 1.0 mm (range, 0.8 to 1.3 mm). After complete endovascular exclusion, the PWM was 25% (range, 16% to 37%) of the preoperative value (p < 0.001), and aneurysm diameter decreased by 8 mm (range, 6 to 14 mm) (p < 0.001). After 18 months, no further diameter reduction occurred. In three patients without endoleaks but with enlarging aneurysms, the postoperative PWM showed less reduction (p < 0.05). Aneurysms with endoleaks showed no diameter decrease, and the postoperative PWM was 50% higher than that in the totally excluded cases (p < 0.01). In five patients with transient endoleaks, the PWM was reduced after leakage ceased (p < 0.05). Leaks of various sources displayed similar PWM.

CONCLUSION

The size and PWM of aneurysms are reduced after endovascular repair. The diameter reduction may cease after 1.5 years. Endoleaks are associated with higher PWM than expected. Pressure may be transmitted without evidence of leaks.

Endoluminal abdominal aortic aneurysm surgery

BACKGROUND

The development of devices designed for the endoluminal repair of abdominal aortic aneurysm has led to the emergence of new endovascular techniques.

METHODS

Articles and case reports obtained from a Medline search of the English language literature from 1989 to 1997 are reviewed. This search was carried out using the MeSH heading 'aortic aneurysm, abdominal' and the keywords 'endovascular' and 'endoluminal'.

RESULTS

Reported mortality and complication rates for endoluminal aneurysm repair are similar to those following conventional repair, with the exception of continued perfusion of the aneurysm sac which remains a major problem following endoluminal repair.

CONCLUSION

Successful endoluminal aneurysm exclusion is associated with reduced aneurysm diameter. However, longer term results of endoluminal repair, in particular of sealed endoleaks, are required before randomized controlled trials of endoluminal versus conventional repair can be undertaken.

Successful endoluminal repair of arterial aneurysms by Wallstent prosthesis and PTFE graft: preliminary results with a new technique

PURPOSE

To describe a new method of endovascular aneurysm exclusion using a Wallstent-PTFE vascular prosthesis in patients at high risk for surgery.

METHODS AND RESULTS

Two patients with significant comoribidities refused surgery in favor of endoluminal grafting for treatment of aneurysms in the abdominal aorta and popliteal artery, respectively. Both endovascular procedures were performed percutaneously with local anesthesia using a low-profile customized endograft constructed of thin-walled, predilated polytetrafluoroethylene (PTFE) graft mounted on a Wallstent. In both cases, the aneurysm was excluded from the arterial circulation; there were no postprocedural complications. Follow-up evaluation with appropriate imaging at 8 months (popliteal aneurysm) and 2 months (abdominal aneurysm) revealed no endoleaks.

CONCLUSIONS

Our preliminary results indicate that the Wallstent-PTFE graft, with its smaller diameter and flexible design, offers significant advantages over currently available devices for repair of arterial aneurysms. This method obviates the need for general anesthesia or surgical exposure for arterial repair, which would increase the risk of the procedure in these patients.