Endovascular repair of late abdominal aortic aneurysm rupture owing to mixed-type endoleak following endovascular abdominal aortic aneurysm repair

We report the successful endovascular repair of a ruptured abdominal aortic aneurysm (AAA) in a multimorbid patient 8 months after endovascular abdominal aortic aneurysm repair (EVAR). A 74-year-old man with a history of EVAR 8 months earlier presented with hypotension, severe back pain, and tenderness on abdominal palpation. A contrast-enhanced computed tomographic scan showed a large retroperitoneal hematoma and confirmed the diagnosis of secondary abdominal aortic rupture. Because the patient had severe comorbidities, the endovascular method was chosen for further management. Two stent grafts were placed appropriately to eliminate a type 1a and a type 3 endoleak owing to modular separation of the left iliac graft limb from the main body stent graft. An additional self-expanding stent was deployed in the solitary right renal artery to open its origin, which was partially overlapped by the proximal cuff. The patient was discharged on the tenth postoperative day and is alive and well 1 year postoperatively. This case indicates that endovascular repair is feasible not only in cases of primarily ruptured AAAs but also in secondarily ruptured AAAs after failure of EVAR.     

Conformational changes associated with proximal seal zone failure in abdominal aortic endografts

OBJECTIVE: Endovascular aneurysm repair (EVAR) has become a popular treatment for abdominal aortic aneurysm (AAA). This study examines conformational changes in the infrarenal aortas of patients in whom proximal seal zone failures (PSF) developed after EVAR. METHODS: All 189 patients with aortic endograft underwent routine post-EVAR computed tomographic scan surveillance. Patients identified with proximal type I endoleaks, type III endoleaks, or proximal component separation without demonstrable endoleak underwent three-dimensional reconstruction of the computed tomographic scans from which measurements of the migration, length, volume, and angulation of the infrarenal aorta were made. RESULTS: Five patients (3%) had PSF develop, four of whom had aortic extender cuffs. Although changes in the AAA volume and aortic neck angle were slight or variable, the mean AAA length increased 34 mm and the mean aortic body angulation increased 17 degrees (P =.03 and.01, respectively). Lengthening and migration caused proximal component separation in four patients, with concomitant migration in two patients. Two patients underwent endovascular repair, two patients needed explantation of the endograft, and one patient awaits endovascular repair. Proximal component separation and type III endoleak recurred in one patient and were repaired with a custom-fitted graft. CONCLUSION: PSF of aortic endografts is associated with proximal angulation and lengthening of the infrarenal aorta. These findings reinforce the importance of proper initial deployment to minimize the need for aortic extender cuffs, which pose a risk of late endoleak development.     

腹主动脉瘤腔内修复术后各型内漏相关性分析（附272例报告）

目的: 探讨腹主动脉瘤（abdominal aortic aneurysm, AAA）腔内修复术后发生内漏的危险因素。方法: 回顾性分析2014年1月至2015年10月272例AAA病人行腔内修复术的临床资料和术后3、6、12、24、36个月随访结果。分析腔内修复术后各型内漏发生率及其与临床特征、支架类型、动脉瘤颈结构的关系。结果: 272例病人腔内修复术后内漏总发生率为15.8%(43/272),其中Ⅰ、Ⅱ、Ⅲ或Ⅳ型以及张力性内漏（Ⅴ型）的发生率分别为7.4%(20/272)、6.3%(17/272)、1.5%(4/272)和0.7%(2/272)。Ⅰ型内漏多在随访3个月时发现,而其他类型内漏在随访12个月或更晚发现。动脉瘤近端瘤颈短（<1.5 cm）、重度扭曲（>45°）、形状不规则或钙化程度高（>25%）与Ⅰa型内漏发生显著相关（P<0.05）。持续通畅的肠系膜下动脉以及存在≥2根罪犯血管是Ⅱ型内漏发生的危险因素（P<0.05）。年龄、美国麻醉医师协会（American Society of Anesthesiologists, ASA）病情分级、吸烟以及合并高血压、糖尿病、冠心病、肺部疾病等对内漏发生率无影响。不同类型的人工血管支架对内漏发生有显著影响（P=0.047）。与其他类型支架相比,Endurant支架的内漏发生率最低（10.7%）。结论: 制定腔内修复手术方案时,应充分评估AAA的特征和内漏风险,以期达到较好的疗效。     

复杂瘤颈的近肾腹主动脉瘤腔内修复中烟囱技术的应用

目的探讨瘤颈解剖复杂的近肾腹主动脉瘤(juxtarenal aortic aneurysms,JAA)腔内修复(endovascular aneurysmrepair,EVAR)中应用烟囱技术的价值。方法 2007年1月～2011年10月,对7例瘤颈复杂的JAA采用EVAR治疗。由于瘤颈解剖结构不适于标准的腔内修复方案,术中自肱动脉穿刺预先于可能被覆膜支架主体覆盖的肾动脉置入导丝,置入修复腹主动脉瘤的覆膜支架主体后造影明确肾动脉覆盖情况,于相应肾动脉置入自膨支架或球囊扩张支架,以延长瘤颈长度使之符合EVAR要求,并有效保护肾动脉(即烟囱技术),然后再完成标准EVAR操作。结果 7例手术全部获成功。7例使用9枚肾动脉支架,其中5枚球扩支架,4枚自膨支架。腔内治疗最后的造影显示:腹主动脉瘤(abdominal aortic aneurysm,AAA)瘤腔隔绝良好,肾动脉血流良好。术中1例近端Ⅰ型内漏,近端增加Cuff后内漏消失;1例造影显示少量的Ⅱ型内漏,无须处理。7例随访1～52个月,平均11.6月:1例术后2个月因心功能衰竭死亡;1例Ⅱ型内漏术后3个月随访内漏消失;肾动脉烟囱支架均保持通畅。结论对于不适宜行开腹手术治疗的瘤颈解剖不佳的JAA,烟囱技术是传统EVAR技术的有效补充,远期效果及肾动脉支架长期通畅性尚需要进一步观察。     

Intravascular ultrasound aids in the performance of endovascular repair of abdominal aortic aneurysm

PURPOSE: The purpose of this retrospective review was to assess the accuracy of aortic measurements with intravascular ultrasound scan (IVUS) compared with computed tomographic (CT) scan and to assess the role of IVUS in the performance of endovascular repair of abdominal aortic aneurysms (AAAs). METHODS: Seventy-eight patients undergoing repair of AAA with the AneuRx stent graft (Medtronic AVE, Inc, Santa Rosa, Calif) underwent measurement with CT scan and IVUS. The initial selection of stent graft size was made on the basis of the CT scan measurements, but the final decision for size was made on the basis of the IVUS measurements. Standard measurements of a phantom tube obtained with IVUS, CT scan, and digital caliper were also compared. RESULTS: IVUS measurements of the phantom standard agreed closely with CT scan measurements. However, stent graft size initially selected with CT measurement was altered in 28% of cases on the basis of intraoperative IVUS measurements. No type I endoleaks were encountered in our series, and no aortic cuffs were necessary for endoleak repair. CONCLUSION: IVUS accurately measures the aorta for selection of stent grafts for endovascular repair of AAA and may prevent type I endoleaks and remedial procedures for their repair.     

Successful treatment of endotension and aneurysm sac enlargement with endovascular stent graft reinforcement

Abdominal aortic aneurysm (AAA) enlarges after successful endovascular repair because of endoleak, which is persistent blood flow within the aneurysm sac. In the absence of detectable endoleak, AAA may still expand, in part because of endotension, which is persistent pressurization within the excluded aneurysm. We report three patients who underwent successful endovascular AAA repair using the Excluder device (W. L. Gore & Associates, Flagstaff, Ariz). Although their postoperative surveillance showed an initial aneurysm regression, delayed aneurysm enlargement developed in all three, apparently due to endotension. Endovascular treatment was performed in which endograft reinforcement with a combination of aortic cuff and iliac endograft extenders were inserted in the previously implanted stent grafts. The endograft reinforcement procedure successfully resulted in aneurysm sac regression in all three patients. Our study underscores the significance of increased graft permeability as a mechanism of endotension and delayed aneurysm enlargement after successful endovascular AAA repair. In addition, our cases illustrate the feasibility and efficacy of an endovascular treatment strategy when endotension and aneurysm sac enlargement develops after endovascular AAA repair.     

Aortoduodenal fistula occurring after type II endoleak treatment with coil embolization of the aortic sac

A bifurcated stent graft device was successfully deployed to exclude an asymptomatic abdominal aortic aneurysm (AAA) with adequate proximal aortic neck morphology. At 6 months, a type II endoleak was successfully embolized through a proximal perigraft channel with metallic coils. The patient was seen with upper gastrointestinal bleeding and a pulsatile abdominal mass 11 months later. Surgical exploration revealed an aortoduodenal fistula in the vicinity of the previous embolization. We discuss the possible causes of this complication and review the literature on the subject. We conclude that aortoduodenal fistula can occur after endovascular AAA repair despite the absence of endoleak or AAA diameter increase on follow-up computed tomographic scan.     

主动脉腔内修复术后中远期并发症与二次处理策略

目的探讨主动脉腔内修复术后中远期并发症的处理方法与效果。方法1999年5月至2007年6月对21例主动脉病变腔内修复术后中远期并发症进行了再次处理。其中腹主动脉瘤（AAA）15例,胸主动脉动脉瘤（TAA）3例,主动脉夹层（TAD）3例。并发症：Ⅰ型内漏11例,Ⅱ型内漏4例,Ⅲ型内漏2例;移植物阻塞4例。应用延长支架型血管技术处理Ⅰ、Ⅲ型内漏（6例）,应用“侧孔”、“凹口”、“分叉”支架型血管结合颈部血管旁路手术重建主动脉弓处理Ⅰ型内漏（3例）,应用栓塞技术处理Ⅱ型内漏（4例）,应用取栓和旁路手术技术处理移植物阻塞（4例）,应用开放手术技术处理动脉瘤破裂（1例）。结果20例（95．2％）应用腔内技术作为二次处理主要手段,二次处理30d内死亡1例（4．7％）,因技术需要而修改器材结构者3例。二次术后仍存在内漏者5例（29．4％,5／17）。二次干预瘤体相关性死亡3例（14．3％）。结论内漏和移植物阻塞是腔内修复术后主要中远期并发症,其主要原因是原发性内漏的延续和移植物移位。腔内技术可作为二次处理的主要手段。主动脉弓部病变进行二次干预有更大的挑战性。     

Acute and chronic open conversion after endovascular aortic aneurysm repair: a 14-year review

OBJECTIVE: This study reviewed outcomes of patients requiring surgical conversion after endovascular abdominal aortic aneurysm (AAA) repair. METHODS: Records for all patients undergoing open conversion after endovascular AAA repair were reviewed. RESULTS: From 1993 to 2006, 574 patients underwent endovascular repair for AAA. Seventeen patients, including three patients who underwent prior endovascular repair at other centers, required surgical conversion with complete (n = 9) or partial graft removal (n = 8). Five patients required immediate conversion (acute), and 12 underwent delayed conversion 4 to 72 months after endovascular repair. Indications for acute conversion were large type I endoleak (n = 3, 60%), including one patient with graft migration, and retroperitoneal bleeding (n = 2, 40%). Indications for chronic conversion were endoleak with increasing aneurysm size (n = 9, 75%), stent fracture without endoleak (n = 1, 8%), delayed retroperitoneal bleeding (n = 1, 8%), and infection (n = 1, 8%). Suprarenal aortic cross-clamping was required in two patients (12%), and endograft components were retained in eight (47%). An aortic occlusion balloon placed through the body of the existing endograft facilitated proximal control in three patients. There were two perioperative deaths in the acute conversion group (2/5; 40%) and none in the delayed conversion group (P = .04). Five-year actuarial survival was 71.9%. Mean follow-up was 41.6 +/- 32.2 months. Retained endovascular components in patients with partial graft removal remained stable during follow-up. CONCLUSIONS: Surgical conversion after endovascular AAA repair can be performed without suprarenal clamping in most patients. Endovascular aortic control with a balloon avoids suprarenal exposure. Partial endograft removal in selected patients facilitates open conversion and appears durable. Acute conversion is associated with increased mortality.     

Management of endoleak after endovascular aneurysm repair: cuffs,coils, and conversion

OBJECTIVE: The effectiveness of endovascular treatment of abdominal aortic aneurysm (AAA) may be limited by persistent perfusion of the aneurysm sac (endoleak). Endoleak that results in persistent systemic pressurization of the aneurysm or in continued AAA expansion is believed to require treatment to prevent rupture. This report describes the results of three techniques used to treat endoleak. METHODS: Endovascular repair of AAA was performed in 597 patients between January 1996 and September 2002. Seventy-three endoleaks that required treatment developed in 70 patients (11.7%). These involved the graft attachment site (type I) or the graft junction site (type III) or originated from collateral side-branch vessels (type II) and were associated with an increase in aneurysm size. Endoleak type was confirmed at angiography in all cases. Average time between the initial endovascular procedure and endoleak treatment was 14.5 +/- 5.7 months. The techniques used for endoleak treatment were deployment of an endovascular extension graft or cuff (n = 44), coil embolization (n = 24,) and conversion to conventional open repair (n = 5). Configurations of endovascular grafts in which endoleak developed were bifurcated (n = 44), aortouniiliac (n = 15), and aortoaortic-tube (n = 11). Mean follow-up after endoleak treatment was 24.5 +/- 12.2 months (range, 1-60 months). RESULTS: Endovascular extension grafts or cuffs were used to treat 41 attachment site endoleaks and 3 graft junction endoleaks, with overall technical success rate of 97%. Embolic coils were used to treat 16 retrograde side-branch endoleaks and 8 attachment site endoleaks, with overall technical success rate of 87%. Conversion to open surgery was performed in 4 patients with attachment site endoleaks and 1 patient with a graft junction site endoleak, and was successful in all cases. After endoleak treatment, aneurysm size decreased (>5 mm) in 38% of patients, stabilized in 58% of patients, and increased (>5 mm) in 4% of patients. Major morbidity occurred in 7.0%, with no perioperative deaths. CONCLUSIONS: Endovascular extension grafts, coil embolization, and conversion to open surgery each may be used to effectively repair endoleak. Selection of the treatment method used is determined by the anatomic characteristics of the endoleak and the patient's ability to tolerate conventional repair. Conversion to open repair was uniformly successful. Deployment of an extension cuff was successful when complete closure of the endoleak was achieved. Embolic coils were effective for retrograde endoleaks and provided stabilization of AAA size in selected patients with attachment site endoleaks in limited follow-up.     

Aortic arch and descending thoracic aortic aneurysms: experience with stent grafting for second-stage "elephant trunk" repair

Reconstruction of aortic arch and descending thoracic aortic aneurysms (TAAs) is technically challenging and associated with significant morbidity and mortality. We report our experience with extensive TAAs using a two-stage "elephant trunk" repair, with the second stage completed using an endovascular stent graft (ESG). Over 6 years, 111 patients underwent ESG treatment of TAAs at Mount Sinai Medical Center. Twelve of these patients were referred for ESG placement for the second stage of elephant trunk reconstruction because comorbidities placed them at high risk of open surgical repair. Our database was analyzed for technical and clinical success and perioperative complications. The mean follow-up was 11.8 months (range 1-64 months). Twelve patients (five women and seven men) with a mean age of 69 +/- 10 years underwent repair of their distal aortic arch and descending TAAs. These aneurysms included nine atherosclerotic aneurysms, one pseudoaneurysm, and two penetrating atherosclerotic ulcers. Three patients were symptomatic. Stent graft repair was technically successful in 91.7% or 11 of 12 patients. Excessive aortic arch tortuosity resulted in failure to deploy a stent graft in one patient. An antegrade approach through the open elephant trunk was used in two patients with severe iliac occlusive disease. Endoleaks (type 2) were identified in two patients with no aneurysm expansion; however, a 14 mm expansion over 1 year occurred in a patient with no identifiable endoleak. One early mortality occurred in a patient with a ruptured 6 cm infrarenal AAA after successful exclusion of the 8 cm TAA. Second-stage elephant trunk reconstruction of an extensive TAA using an ESG is effective in the short term. Its long-term durability remains to be determined.     

Hybrid endovascular repair with reconstruction of superior mesenteric and celiac arteries for thoracoabdominal and abdominal aortic aneurysms

A 79-year-old woman presented with sustained thoracolumbar back pain. Contrasted computed tomography (CT) showed a thoracoabdominal aortic aneurysm (TAAA: type I of Crawford classification) and an abdominal aortic aneurysm (AAA) that were not ruptured. Considering her age, the placement of an endovascular stent graft was performed for TAAA at the possible sacrifice of the celiac (CA) and superior mesenteric arteries (SMA). In order to prevent ischemic events, it was necessary that blood supply to the CA and SMA was maintained by placing a graft to each artery from the Y-shaped graft for replacement of AAA. Actually, only CA was sacrificed and coil embolization of CA was needed because of type 2 endoleak. The patient was discharged 17 days after surgery. A hybrid technique, endovascular repair with reconstruction of abdominal branches for TAAA and AAA, can be an alternative procedure for such high-risk operation with multiple aortic aneurysms including TAAA.     

Nonanastomotic rupture of thoracic aortic Dacron graft treated by endovascular stent graft placement

A 61-year-old man had a Stanford type A acute aortic dissection, and the total aortic arch was replaced with 22-mm knitted Dacron graft in 1996. In 2006, he underwent mitral valve replacement and tricuspid valve repair due to severe mitral and tricuspid valve regurgitation. Although preoperative computed tomography (CT) scan suggested pseudoaneurysm around the Dacron graft replaced with aortic arch, it could not be repaired concomitantly. Four months later, in view of the technical difficulties of an open surgical procedure, the prosthetic graft failure was repaired by endovascular stent graft consisting of a Gianturco Z stent covered with an UBE woven Dacron graft. However, during a follow-up, aneurysm sac diameter increased without any sings of endoleak in follow-up CT scans. Redo endovascular stent graft placement using a Gore-TAG device was performed. Subsequently, shrinkage of the pseudoaneurysmal sac could be observed.     

Salvage of failed prior endovascular abdominal aortic aneurysm repair with fenestrated endovascular stent grafts

Three patients with type I proximal endoleak after previous endovascular abdominal aortic aneurysm (AAA) repair were treated with fenestrated endovascular stent grafts. Six renal arteries, three superior mesenteric arteries, and one coeliac axis were targeted for incorporation by graft fenestration. The fenestration-renal ostium interface was secured with balloon-expandable stents and completion angiography demonstrated no endoleaks and antegrade perfusion in all target vessels. All patients made an uncomplicated recovery. Fenestrated endovascular stent grafts can be used to salvage failed prior endovascular AAA repair in patients who are considered unsuitable for other endovascular or open surgical interventions.     

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应用跨肾动脉支架人工血管腔内修复术治疗腹主动脉瘤,并探讨其手术适应证,操作要点及并发症的预防。方法对２例病人采用全麻,在动态数字减影血管造影监测下用跨肾动脉支架分叉型人工血管对腹主动脉瘤进行了腔内修复术,结果手术中ＤＳＡ提示动脉瘤消失,无内漏发生。术后１周及分别随访３和９个月,螺旋ＣＴ检查提示腔内人工血管无移位扭曲,血流通畅无内漏发生,结论腹主动脉瘤腔内修复术手术创伤小,病人恢复快,跨肾动支架人工     

Use of a bifurcated endovascular graft for treatment of endograft migration with major endoleak

The purpose of this study was to describe the use of a bifurcated endovascular graft to treat endograft migration with major endoleaks. We present four patients who presented at a mean of 72.0 months after their initial endovascular abdominal aortic aneurysm repair. Three patients had type I endoleaks resulting from proximal attachment failure and graft migration. A fourth patient had separation of a proximal aortic cuff from a migrated main body device resulting in a type III endoleak. All were treated with a bifurcated Zenith (Cook Medical Incorporated, Bloomington, IN, USA) endovascular graft. There was 100% technical success with no perioperative complications. On follow-up, one patient died of unrelated causes at five months. The mean survival for the remaining three patients was 37 months. In conclusion, treatment with a bifurcated Zenith endograft has advantages over the use of an aortic cuff or aortouniiliac reconstruction. To perform this technique, there must be a sufficient distance between the proximal landing zone and the flow divider of the migrated endograft to allow for deployment of the Zenith device. While there remain limitations in its applicability, the use of a bifurcated endovascular graft is a viable alternative for endovascular salvage in treatment of endograft migration with major endoleaks.     

Abdominal aortic aneurysm size regression after endovascular repair is endograft dependent

OBJECTIVE: This study was performed to determine whether abdominal aortic aneurysm (AAA) regression is different with various endografts after endovascular repair. METHODS: A four-center retrospective review of size change after endovascular AAA repair was performed. Consecutive patients with at least 1-year follow-up and available imaging studies were included. Three hundred ninety patients received either the Ancure, AneuRx, Excluder, or Talent endograft. AAA size and endoleak status were recorded from computed tomography (CT) scans at the initial postoperative follow-up visit and at 1 and 2 years thereafter. AAA size was defined as the minor axis of the infrarenal aorta on the largest axial section on the two-dimensional CT scan. A change in AAA size of 0.5 cm or greater from baseline was considered clinically significant. The effect of initial size, endoleak, and type of endograft on AAA regression was analyzed. RESULTS: Mean baseline size was significantly greater with Talent endografts and smaller with Excluder endografts. Clinically significant regression in AAA size occurred in nearly three fourths of patients with Ancure and Talent endografts at 2 years. Regression in AAA size was less frequent with the AneuRx (46%) and Excluder (44%) devices. Initial size, endoleak, and endograft type were significant predictors of regression at multivariate analysis at 1 year. However, by 2 years only endograft type was still an independent predictor of AAA shrinkage. CONCLUSIONS: Long-term morphologic changes after endovascular aneurysm repair depend on endograft type.     

Migration of a bifurcated endovascular graft into an iliac aneurysm: endovascular salvage and future prevention--a case report

The FDA approval of endovascular grafts for the treatment of abdominal aortic aneurysms has been associated with a dramatic increase in the use of these devices. Major referral centers are reporting the treatment of 75% to 80% of their patients with infrarenal abdominal aortic aneurysms with endovascular devices. The large quantity of endovascular devices being used has produced a growing number of management issues that are often not predictable during the preoperative assessment. These issues require complex intraoperative decision making and innovative techniques for their management as reflected by the subsequent case report. An 82-year-old patient presented with a 7.8-cm abdominal aortic aneurysm. The aneurysm extended into the common iliac arteries bilaterally. The right common iliac artery was 6.5 cm and the left common iliac artery was 2.0 cm in maximal diameter. The preoperative work-up, including a computed tomography scan and arteriogram, suggested that he would be a potential candidate for endovascular repair. The plan was to extend the graft into the right external iliac artery after embolization of the right hypogastric artery and to seal the left limb in the ectatic left common iliac artery using an aortic extender cuff. During the endovascular repair of the aortoiliac aneurysms using the AneuRx bifurcated graft, the main device became dislodged from its infrarenal attachment site and migrated into the large right common iliac artery aneurysm with the iliac limb ending in the distal external iliac artery. A new bifurcated device was deployed from the left side to attempt an endovascular salvage of the difficult situation. The new graft was partially deployed down to the iliac limb. This allowed cannulation of the contralateral stump through the original endovascular graft that had migrated distally. The two grafts were connected with a long iliac limb. This allowed stabilization of the endovascular reconstruction by increasing its columnar strength. The deployment of the second bifurcated graft was completed and the central core with the runners removed safely without migration of the second bifurcated component. The reconstruction was completed with an aortic cuff in the left common iliac artery. The use of the aortic cuff was useful to preserve the left hypogastric artery. No intraoperative endoleak was noted. The patient did well and was discharged the day following the procedure. The follow-up computed tomography scan shows the abdominal aortic aneurysm excluded by the endovascular graft with a defunctionalized portion of one bifurcated graft within the right common iliac aneurysm. There is no evidence of endoleak and the abdominal aortic aneurysm had decreased in size at 6 months. This case demonstrates one of the unique management problems that may arise during endovascular graft placement. Events that initially would suggest failure of the endoluminal treatment may be corrected using advanced endovascular techniques by an experienced surgeon. However, there will be times that the prudent decision will be conversion to open repair. Only good clinical judgement and adequate training will prevent catastrophic outcomes.     

First experience in human beings with a permanently implantable intrasac pressure transducer for monitoring endovascular repair of abdominal aortic aneurysms

OBJECTIVES: Endovascular stent graft repair of abdominal aortic aneurysms (AAAs) prevents rupture by excluding the aneurysm sac from systemic arterial pressure. Current surveillance protocols after endovascular aneurysm repair (EVAR) follow secondary markers of sac pressurization, namely, endoleak and sac enlargement. We report the first clinical experience with the use of a permanently implantable, ultrasound-activated remote pressure transducer to measure intrasac pressure after EVAR. METHODS: Over 7 months, 14 patients underwent EVAR of an infrarenal abdominal aortic aneurysm with implantation of an ultrasound-activated remote pressure transducer fixed to the outside of the stent graft and exposed to the excluded aortic sac. Twelve patients received modular bifurcated stent grafts, and 2 patients received aortouniiliac devices. Intrasac pressures were measured directly with an intravascular catheter and by the remote sensor at stent-graft deployment. Follow-up sac pressures were measured with a remote sensor and correlated with systemic arterial pressure at every follow-up visit. Mean follow-up was 2.6 +/-1.9 months. RESULTS: Excellent concordance was found between catheter-derived and transducer-derived intrasac pressssure intraoperatively. Pulsatile waveforms were seen in all functioning transducers at each evaluation interval. One implant ceased to function at 2 months of follow-up. In 1 patient a type I endoleak was diagnosed on 1-month computed tomography (CT) scans; 3 type II endoleaks were observed. Those patients with complete exclusion of the aneurysm on CT scans had a significant difference in systemic and sac systolic pressures initially (P <.001) and at 1 month (P <.001). Initial sac diastolic pressures were higher than systemic diastolic pressures (P <.001). The ratio of systemic to sac systolic pressure increased over time in those patients with complete aneurysm exclusion ( P <.001). Four of 6 patients with no endoleak and greater than 1-month follow-up had diminution of sac systolic pressure to 40 mm Hg or less by 3 months. CONCLUSION: This is the first report of a totally implantable chronic pressure transducer to monitor the results of EVAR in human beings. Aneurysm exclusion leads to gradual diminution of sac pressure over several months. Additional clinical follow-up will be necessary to determine whether aneurysm sac pressure monitoring can replace CT in the long-term surveillance of patients after EVAR.     

The Powerlink bifurcated system for endovascular aortic aneurysm repair: four-year results of the US multicenter trial

The aim of the study was to review the results of abdominal aortic aneurysm (AAA) repair with the Powerlink Bifurcated endovascular graft, when compared with open AAA repair. A prospective, controlled, multicenter trial of the Powerlink System for endovascular abdominal repair (EVAR) was conducted at 15 sites as part of a pivotal FDA trial. Between July 2000 and March 2003, 258 patients were enrolled (192 test and 66 control patients). Stent grafts were oversized by 10-20% relative to computed tomography (CT)-based diameter measurements. All repairs were performed in the operating room through one surgically exposed femoral artery and a contralateral 9 French sheath percutaneously placed. Results were assessed using contrast-enhanced CT and plain abdominal X-rays at 1, 6, and 12 months and annually postoperatively. Mean follow-up of 36 months was available. Technical success was achieved in 97.9% of patients, with 4 failed insertions: 3 early conversions for deployment issues and one access failure. There was a significant difference in 30-day mortality between Powerlink (1%) and control (6.1%) patients and only 1 death was procedure-related (P=0.0389). Blood loss (341 mL vs 1 583 mL, P<0.0001), operative time (136 min vs 222 min, P<0.0001), Intensive Care Unit (ICU) stay (0.78 days vs 4.1 days, P<0.0001) and hospital length of stay (3.3 days vs 9.5 days, P<0.0001) were significantly less in the Powerlink cohort compared with controls. Secondary procedures have been performed on 16 patients post-implant to 48 months follow-up. At the time of the first month CT scan, endoleaks were noted in 25 patients, yielding a 30-day endoleak rate of 22.3%. Type II endoleaks predominated and there were no type III or IV endoleaks. The 4-year endoleak-free survival rate was 73%. No Type I, III or IV endoleaks were reported at 48 months post-implant. There have been no ruptures, graft fabric defects or wire fractures. Sac regression was noted in 83% of patients. Significant reduction in mean AAA diameter and volume was noted over every follow-up interval. In comparison to the 1-month post-implant CT scan, 2 patients had an increase in AAA diameter 5 mm at 48 months. The Powerlink system appears to be safe, and effectively protects patients from AAA rupture over the follow-up period. The graft and stent materials are still free from failure and fatigue. Contralateral limb access (9 Fr) facilitates graft placement in patients with disadvantaged access routes. EVAR performed with the Powerlink produces significantly less early adverse events than open AAA repair. Continued follow-up over the longer term is necessary to assure the durability of these results.