The incidence, natural history, and outcome of secondary intervention for persistent collateral flow in the excluded abdominal aortic aneurysm

Open repair for Sac Expansion after EVAR

BACKGROUND

This study aimed to examine the outcomes of open surgery techniques involving sacotomy and suturing of the feeding vessels in patients with aneurysm sac expansion after endovascular aneurysm repair (EVAR).

METHODS

Fourteen consecutive patients treated with sacotomy and suturing of feeding vessels for expanding aneurysm sacs with type II endoleaks following EVAR, between January 2018 and December 2022, were retrospectively included. All patients underwent preoperative digital subtraction angiography, and attempts were made to embolize the thick feeding vessels to reduce intraoperative bleeding. Age, sex, comorbidities, clinical presentation, aneurysm sac increase, morbidity, mortality, and follow-up were recorded.

RESULTS

The median age of the patients was 72.89±5.13 years old, and 13 (92.9%) patients were male. The sac size at the time of the open procedure was 107.89±22.58 mm, and the extent of sac growth at the time of the open procedure was 37.50±18.29 mm. The initial technical success rate of laparotomy and open ligation of the culprit arteries causing type II endoleaks was 92.9% (13/14). Among the patients, five (35.7%) had been treated with interventional embolization before the open procedure. One endograft was removed and replaced by a bifurcated Dacron graft because of distal dislocation in one patient. All patients recovered, and no deaths were recorded postoperatively. No patients had an eventful postoperative course or any subsequent graft-related complications during follow-up.

CONCLUSIONS

Open surgical repair involving sacotomy and suturing of the feeding vessels appeared to have good outcomes in the treatment of patients with aneurysm sac expansion caused by type II endoleaks after EVAR. Preoperative embolization of feeding vessels can thus effectively reduce intraoperative bleeding.

Endovascular approach to arterial branches mimicking a type II endoleak after popliteal artery aneurysm exclusion and bypass

The management of popliteal artery aneurysms (PAAs) has continued to evolve. Open surgical treatment remains an excellent option. Aneurysm exclusion with saphenous vein bypass through a medial incision remains a preferred approach. After PAA exclusion, however, a possibility remains of sac expansion from geniculate arterial branches. This can mimic a type II endoleak occurring after endovascular aortic aneurysm repair. In the present report, we have described an endovascular technique used to treat an enlarging PAA after exclusion and bypass.

Editor's Choice - Systematic Review and Meta-Analysis of the Outcome of Treatment for Type II Endoleak Following Endovascular Aneurysm Repair

OBJECTIVES

The efficacy and need for secondary interventions for type II endoleaks following endovascular abdominal aortic aneurysm repair (EVAR) remain controversial. This systematic review aimed at investigating the clinical outcomes of different type II endoleak treatments in patients with a persistent type II endoleak after EVAR.

DATA SOURCES

Embase, Medline via Ovid, Web of Science Core Collection, the Cochrane CENTRAL, and Google Scholar.

REVIEW METHODS

This systematic review was performed in accordance with the PRISMA Statement. Outcomes of interest were technical and clinical success, change in sac diameter, complications, need for additional interventions, abdominal aortic aneurysm (AAA) rupture, and (AAA related) mortality. Meta-analyses were performed with random effects models.

RESULTS

A total of 59 studies were included, with a cumulative cohort of 1073 patients with persistent type II endoleak. Peri-operative complications following treatment of type II endoleaks occurred in 3.8% of patients (95% CI 2.7-5.2%), and AAA related mortality was 1.8% (95% CI 1.1-2.7%). Overall technical success was 87.9% (95% CI 83.1-92.1%), while clinical success was 68.4% (95% CI 61.2-75.1%). Among studies detailing sac dynamics, decrease or stable sac, with or without resolution, was achieved in 78.4% (95% CI 70.2-85.6%). Changes in sac diameter following type II endoleak treatment were documented in 157 patients to at least 24 months. Within this group an actual decrease in sac diameter was reported in only 27 of 40 patients.

CONCLUSION

There is little evidence supporting the efficacy of secondary intervention for type II endoleaks after EVAR. Although generally safe, the lack of evidence supporting the efficacy of type II endoleak treatment leads to difficulty in assessing its merits.

Open Surgical Repair Can Be One Option for the Treatment of Persistent Type II Endoleak after EVAR

PURPOSES

Endovascular abdominal aortic aneurysm repair (EVAR) is an increasingly used method of repairing abdominal aortic aneurysm (AAA). However, the treatment of persistent type II endoleak is still a controversial issue. Five cases are reported here in which we performed open surgical repair of growing aneurysm due to persistent type II endoleak.

METHOD

Totally 128 EVAR cases were retrospectively reviewed, which were operated in our hospital from April 2008 to October 2013. These cases were followed by periodical contrast-enhanced computed tomography (CT) after EVAR. When persistent type II endoleak caused aneurysm sac growth, we performed surgical repair method for the first line treatment. In the operation, we incised the aneurysm sac by abdominal small median incision approach and sutured lumber arteries from inside of aneurysm sac and tied inferior mesenteric artery (IMA) in addition to aneurysmorrhaphy. Contrast-enhanced CT scanning was performed in a week after open repair for the confirmation of complete treatment.

RESULTS

Five of 128 cases (3.9%) were needed to be surgically repaired because of aneurysm sac growth (>5 mm), including two ruptured AAA cases. All patients recovered uneventfully. Contrast-enhanced CT scanning performed a week after these operations showed no endoleak and intact stent grafts and reduction of the aneurysm size.

CONCLUSION

We believe open surgical repair method of persistent type II endoleak with aneurysm expansion is secure method, and can be one of the preferable options for this life threatening complication after EVAR.

Successful Percutaneous Coil Embolization of a Ruptured Internal Iliac Artery Aneurysm Remnant after Abdominal Aortic Aneurysm Repair via the Deep Iliac Circumflex Artery

Here, we describe a case of an 83-year-old man treated with percutaneous IIA coil embolization for an enlarging remnant IIA aneurysm. CT scans revealed a contained rupture and persistent flow in the right IIA with the enlargement. We selected percutaneous embolization via the deep iliac circumflex artery, that was communicating with the superior gluteal artery and the IIA. Coil embolization of the arteries supplying the IIA aneurysm was successfully performed with 12 embolization coils placed in the IIA and its branches. The absence of blood flow and shrinkage of the aneurysm were confirmed by CT three months after embolization.

Conversion to open repair after endografting for abdominal aortic aneurysm: a review of causes, incidence, results, and surgical techniques of reconstruction

PURPOSE

To review the incidence, causes, and mortality rates of early and late conversion to open surgery after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA).

METHODS

A systematic search of the English-language literature from 2002 to 2009 was performed by interrogation of the PubMed, MEDLINE, and EMBASE databases. Studies were included if they: (1) had >100 patients treated with EVAR and (2) provided adequate data to calculate incidence and associated mortality rates. The search yielded 13 articles with sufficient data to analyze early conversion (12,236 patients, 178 conversions) and 15 articles with available data for late conversion (14,298 patients, 279 conversions).

RESULTS

The rate of early conversion among the 13 articles reviewed ranged from 0.8% to 5.9%; more recent studies carried lower rates of early conversion. Mortality rates of early conversion varied between 0% and 28.5%. Overall, there were 178 (1.5%) early conversions among the 12,236 AAAs treated with EVAR, with an average mortality of 12.4%. The rates of late conversion ranged from 0.4% to 22%. Of the 14,289 AAA patients undergoing endovascular repair, 279 (1.9%) required late conversion; the mortality rate was 10%.

CONCLUSION

Though the incidence is gradually declining, secondary interventions persist as the Achilles' heel of EVAR. A lifelong follow-up strategy for AAA patients treated with EVAR is essential for early detection and treatment of complications of the procedure. Vascular surgeons should be familiar with the complex open conversion procedures.

Sonographic Evaluation of Aortic Endografts

The selective use of endovascular devices to repair abdominal aortic aneurysms was introduced in the early 1990s. Although placement of an aortic endograft offers patients a less morbid alternative to surgical repair, this procedure is not without complications. Persistent perfusion of the residual aneurysmal sac via endoleaks may place the patient at risk for aneurysmal enlargement and subsequent rupture. Historically, serial computed tomographic angiography has been used as the primary modality for assessment of aortic endografts. In recent years, sonography has been shown to provide a valued tool for ongoing surveillance of aortic endografts and identification of endoleaks, increasing aneurysmal size, hemodynamic disorders, and graft migration and/or kinking. Standardization of the sonographic evaluation yields accurate information vital to the long-term patency of these conduits.

Endovascular treatment of late "endoleak" following open surgical repair using bypass and exclusion aneurysm repair

BACKGROUND

We sought to present endovascular management options of persistent or recurrent aneurysm sac flow ("endoleak") after operative retroperitoneal exclusion of infrarenal abdominal aortic aneurysm (AAA).

METHODS

Recurrent or persistent aneurysm perfusion was diagnosed in three patients primarily treated with aneurysm exclusion and bypass. The medical history, course of disease, and surgical management of these patients were reviewed.

RESULTS

Three patients primarily treated for infrarenal AAA by division of the aorta with suture closure of the proximal aneurysm end, ligation of the outflow vessels, and bypass of the excluded aortoiliac segment presented with persistent or recurrent AAA sac perfusion and growth. The feeding vessels were the iliac arteries in all cases. Endovascular repair using coil embolization and/or deployment of an occluder or stent-graft was successful in all patients with a follow-up of 42, 36, and 30, months respectively.

CONCLUSION

Open AAA repair using the exclusion and bypass technique is associated with the risk of persistent perfusion or reperfusion of the aneurysm sac, which is similar to an endoleak after endovascular aortic aneurysm exclusion. Endovascular therapy should be considered as first-choice treatment when feasible.

Persistent type 2 endoleak after endovascular repair of abdominal aortic aneurysm is associated with adverse late outcomes

OBJECTIVE

Type 2 endoleak occurs in up to 20% of patients after endovascular aneurysm repair (EVAR), but its long-term significance is debated. We reviewed our experience to evaluate late outcomes associated with type 2 endoleak.

METHODS

During the interval January 1994 to December 2005, 873 patients underwent EVAR. Computed tomography (CT) scan assessment was performed < or =1 month of the operation and at least annually thereafter. Sequential 6-month CT scan follow-up was adopted for those patients with persistent type 2 endoleaks, and reintervention was limited to those with sac enlargement >5 mm. Study end points included overall survival, aneurysm sac growth, reintervention rate, conversion to open repair, and abdominal aortic aneurysm (AAA) rupture. Preoperative variables and anatomic factors potentially associated with these endpoints were assessed using multivariate analysis.

RESULTS

We identified 164 (18.9%) patients with early (at the first follow-up CT scan) type 2 endoleaks. Mean follow-up was 32.6 months. In 131 (79.9%) early type 2 endoleaks, complete and permanent leak resolution occurred < or =6 months. Endoleaks persisted in 33 patients (3.8% of total patients; 20.1% of early type 2 endoleaks) for >6 months. Transient type 2 endoleak (those that resolved < or =6 months of EVAR) was not associated with adverse late outcomes. In contrast, persistent endoleak was associated with several adverse outcomes. AAA-related death was not significantly different between patients with and without a type 2 endoleak (P = .78). When evaluating patients with no early endoleak vs persistent endoleak, freedom from sac expansion at 1, 3, and 5 years was 99.2%, 97.6%, and 94.9% (no leak) vs 88.1%, 48.0%, and 28.0% (persistent) (P < .001). Patients with persistent endoleak were at increased risk for aneurysm sac growth vs patients without endoleak (odds ratio [OR], 25.9; 95% confidence interval [CI] 11.8 to 57.4; P < .001). Patients with a persistent endoleak also had a significantly increased rate of reintervention (OR, 19.0; 95% CI, 8.0 to 44.7); P < .001). Finally, aneurysm rupture occurred in 4 patients with type 2 endoleaks. Freedom from rupture at 1, 3, and 5 years for patients with a persistent type 2 endoleak was 96.8%, 96.8%, and 91.1% vs 99.8%, 98.5%, and 97.4% for patients without a type 2 endoleak. Multivariate analysis demonstrated persistent type 2 endoleak to be a significant predictor of aneurysm rupture (P = .03).

CONCLUSIONS

Persistent type 2 endoleak is associated with an increased incidence of adverse outcomes, including aneurysm sac growth, the need for conversion to open repair, reintervention rate, and rupture. These data suggest that patients with persistent type 2 endoleak (>6 months) should be considered for more frequent follow-up or a more aggressive approach to reintervention.

Surgical access of the gluteal artery to embolize a previously excluded, expanding internal iliac artery aneurysm

We describe open exposure of the inferior gluteal artery to allow coil embolization on an enlarging internal iliac artery aneurysm after previous abdominal aortic aneurysm (AAA) repair. An 84-year-old man with a stoma had undergone open AAA repair surgery 8 years previously, during which the proximal aortic neck and both proximal external iliac arteries were ligated, followed by an aorta to right external iliac and left common femoral bypass. Eight years later, he complained of abdominal pain, and a computed tomographic (CT) scan revealed persistent flow in the right internal iliac artery with enlargement to 8 cm in diameter. Because prograde access to the internal iliac artery was not possible as a result of the previous exclusion, the inferior gluteal artery was exposed surgically. Coil embolization of the arteries supplying the internal iliac artery aneurysm was successfully performed. The AAA and internal iliac artery aneurysm were treated by the exclusion technique. Eight years after the operation, CT revealed that the iliac artery had expanded to approximately 8 cm in diameter. The patient was placed face down, and a catheter was directly inserted into the internal iliac artery from the inferior gluteal artery. Four embolization coils were placed in the internal iliac artery and its branches. Absence of blood flow and shrinkage of the aneurysm were subsequently confirmed in the aneurysm, as shown by echogram color duplex scanning and CT scanning at 1 year. This technique could also be applicable for persistent blood flow in an internal iliac aneurysm after endovascular AAA repair, and the size of the aneurysm was reduced to approximately 1 cm 1 year after the operation.

An animal model for type II endoleaks with use of a tsuzumi drum-shaped stent-graft

PURPOSE

To create an animal model of type II endoleaks after endoluminal deployment of a specially designed stent-graft (SG).

MATERIALS AND METHODS

Five swine were used. A tsuzumi drum-shaped SG consisting of a covered Z stent with its diameter narrowed at the center was deployed in the midthoracic aorta. In this way, a residual space (RS) was created between the aortic wall and the graft to simulate an aneurysm sac. A 5-F catheter was placed into the RS, and then aortography, RS angiography, and pressure measurements were performed. Follow-up was performed at 3 and 10 days after the procedure. Mean pressure indexes (MPIs) were calculated as the ratio of the mean RS pressure to the aortic pressure. Histologic examination was also performed.

RESULTS

RSs with two or three pairs of intercostal arteries were successfully created in all cases. Aortography showed two type II endoleaks in five swine just after SG deployment and four type II endoleaks at 10 days. RS angiography showed circulation between the RS and the intercostal arteries in all cases. The mean MPI was 69.4% +/- 10.4% just after SG deployment and increased to 87.8% +/- 5.2% at 10 days. By gross examination, RS patency was retained.

CONCLUSIONS

A swine model of type II endoleaks was successfully created endoluminally. This model does not require direct surgery to the aorta and its side branches and promises to be useful to study the mechanism of and therapy for type II endoleaks.

Does sac size matter? Findings based on surgical exploration of excluded abdominal aortic aneurysms

PURPOSE

To prospectively examine the outcomes of excluded abdominal aortic aneurysms (AAA) that continue to expand without evidence of endoleak.

METHODS

From 1984 to 1998, 1218 patients underwent operative retroperitoneal exclusion of AAA and aortoiliac reconstructions. During the procedure, the aneurysm sac was ligated proximally, as well as distally, which created an ideal in-vivo model of excluded AAA sacs with or without endoleaks. From January 2002 to June 2003, 15 of these patients were identified as having an increase in AAA sac size with or without an endoleak on duplex ultrasonography. These patients were prospectively evaluated by computed tomography and diagnostic arteriography. Patients with a demonstrable endoleak underwent embolization, and the remainder underwent open surgical exploration.

RESULTS

Eight patients had arteriographically demonstrated endoleaks that were treated with coil embolization. The remaining 7 patients (6 men; mean age 76 years, range 68-81) without a demonstrable endoleak underwent elective surgical exploration and sac endoaneurysmorrhaphy. The mean time interval between the original surgery and aneurysm sac exploration was 76 months (range 52-92); during this time, the mean aneurysm sac size increased by 2.7 cm (range 1.3-5.2). The mean sac pressure was 53 mmHg, and the sac walls were noticeably thickened, with markedly dilated vasa vasorum. The sac contained yellow, fibrinous material with clear serous fluid (5 patients without any evidence of retrograde flow) or liquefied thrombus with serosanguinous fluid (2 patients with retrograde flow from lumbar arteries). No AAA sacs were pulsatile.

CONCLUSIONS

Continued expansion of excluded AAA sacs can occur from causes other than a missed endoleak. Exudation of fluid from thickened sac wall and vasa vasorum, as well as local enzymatic activity, might lead to the formation of a sac hygroma. Furthermore, these findings raise questions as to the need for surgical exploration of all patients with an enlarging AAA sac in the setting of low sac pressures and no definable endoleak.

Infrarenal Abdominal Aortic Aneurysm Complicated by Persistent Endotension After Endovascular Repair: Report of a Case

Endoleak and endotension may prevent the successful exclusion of an aneurysm after endovascular aortic aneurysm repair (EVAR). The pressurization in the excluded aneurysm sac caused by endotension may lead to rupture of the aneurysm; however, the cause of endotension and its underlying mechanisms remain unclear. We report a case of infrarenal abdominal aortic aneurysm (AAA) complicated by persistent endotension after EVAR. Although no endoleaks were found on conventional double-phase computed tomographic scans, a thrombosed endoleak existed in the side branch and attachment site of the endograft. After treating the undetectable thrombosed endoleaks, physical examination revealed that the pressure of the excluded aneurysm had diminished, with shrinkage of the aneurysm. This case report suggests that a high-pressure undetectable type I or type II endoleak could be a major cause of endotension. Thus, postoperative evaluation of the attachment site of an endograft is important after EVAR.

Treatment of infrarenal aortic aneurysm by minimally invasive retroperitoneal approach: use of a video-assisted technique

We propose a technique for treating abdominal aortic aneurysm in which first a minilaparotomy (retroperitoneal) is performed to make a conventional arterial dissection; then, video assistance is used to control the left lumbar arteries and to make the aortic anastomosis. This technique can be performed with no significant laparoscopic capability.The patient was installed in a 20-degree right lateral decubitus. A transverse left 8- to 10-cm abdominal incision was made, followed by separation of the muscular structures. Retroperitoneal control of the proximal aortic neck and of both common iliac arteries was obtained by digital and instrumental dissection. A 30-degree laparoscope was then introduced through a 8- to 12-mm trocar and provided the light and magnification that facilitated the dissection of the posterior wall of the aortic neck and of the left flank of the aneurysm, looking for the lumbar arteries to be clipped. A suspended running suture to make the aorto-prosthetic anastomosis was facilitated by the magnification of the camera, especially during the passage of needles. Between March and September 2001, 32 patients fulfilled the anatomic conditions: an infrarenal aortic neck length of 2 cm or more, absence of hypogastric artery aneurysm, and no need for inferior mesenteric artery reimplantation. In 30 patients, the surgery was performed by using the planned minimally invasive approach, and extension of the incision was necessary in two patients.

Outcome of popliteal artery aneurysms after exclusion and bypass: Significance of residual patent branches mimicking type II endoleaks

PURPOSE

Popliteal aneurysms (PAs) often are treated with exclusion and bypass. However, excluded aneurysms can transmit systemic pressure from persistent flow through collateral arteries (endoleak), resulting in aneurysm growth and rupture. We used duplex ultrasound scanning for postoperative surveillance more than 2 years after PA repair with exclusion and bypass, to determine the presence of flow and aneurysm growth.

METHODS

From 1995 to 2001, 23 patients with 26 PAs (mean diameter, 3.2 cm; range, 1.6-5.6 cm) underwent surgical repair and were available for more than 2 years of follow-up. The popliteal artery was ligated proximal and distal to the aneurysm, and autogenous revascularization was performed. All patients who underwent PA endoaneurysmorrhaphy through a posterior approach were excluded from the study. During long-term follow-up, aneurysm sac flow and size were evaluated with duplex ultrasound scanning, computed tomography, or magnetic resonance angiography, and standard angiography. Patients with increased PA size and persistent flow were offered repair through a posterior approach.

RESULTS

Over 7 years, 26 PAs (symptomatic, 11; asymptomatic, 15) treated with aneurysm exclusion and bypass were available for more than 2 years of follow-up (mean, 38 months; range, 24-78 months). In the postoperative period 16 PAs (62%) became thrombosed, 10 (38%) had persistent collateral flow through geniculate vessels, 6 (23%) increased in size, and 3 (12%) ruptured; 1 (4%) resulted in limb loss. Operative findings for all ruptured PAs and 3 of 6 PAs with increased sac size that underwent aneurysm sac exploration and endoaneurysmorrhaphy revealed retrograde flow through geniculate vessels, mimicking type II endoleak.

CONCLUSIONS

These findings question the effectiveness of PA exclusion through proximal or distal ligation and bypass. In addition, retrograde flow into the aneurysm sac (ie, type II endoleak after endovascular abdominal aortic aneurysm repair) may transmit systemic pressure that can result in aneurysm rupture. We recommend PA treatment with aneurysm sac decompression and ligation of geniculate vessels whenever possible and routine postoperative surveillance of the excluded aneurysm sac.

Total laparoscopic infrarenal aortic aneurysm repair: Preliminary results

OBJECTIVES

We describe our initial experience of total laparoscopic abdominal aortic aneurysm (AAA) repair.

MATERIAL AND METHODS

Between February 2002 and September 2003, we performed 30 total laparoscopic AAA repairs in 27 men and 3 women. Median age was 71.5 years (range, 46-85 years). Median aneurysm size was 51.5 mm (range, 30-79 mm). American Society of Anesthesiologists class of patients was II, III and IV in 10, 19, and 1 cases, respectively. We performed total laparoscopic endoaneurysmorrhaphy and aneurysm exclusion in 27 and 3 patients, respectively. We used the laparoscopic transperitoneal left retrocolic approach in 27 patients. We operated on 2 patients via a tranperitoneal left retrorenal approach and 1 patient via a retroperitoneoscopic approach.

RESULTS

We implanted tube grafts and bifurcated grafts in 11 and 19 patients, respectively. Two minilaparotomies were performed. In 1 case, exposure via a retroperitoneal approach was difficult and, in another case, distal aorta was extremely calcified. Median operative time was 290 minutes (range, 160-420 minutes). Median aortic clamping time was 78 minutes (range, 35-230 minutes). Median blood loss was 1680 cc (range, 300-6900 cc). In our early experience, 2 patients died of myocardial infarction. Ten major nonlethal postoperative complications were observed in 8 patients: 4 transcient renal insufficiencies, 2 cases of lung atelectasis, 1 bowel obstruction, 1 spleen rupture, 1 external iliac artery dissection, and 1 iliac hematoma. Others patients had an excellent recovery with rapid return to general diet and ambulation. Median hospital stay was 9 days (range, 8-37 days). With a median follow-up of 12 months (range, 0.5-20 months), patients had a complete recovery and all grafts were patent.

CONCLUSION

These preliminary results show that total laparoscopic AAA repair is feasible and worthwhile for patients once the learning curve is overcome. However, prior training and experience in laparoscopic aortic surgery are needed to perform total laparoscopic AAA repair. Despite these encouraging results, a greater experience and further evaluation are required to ensure the real benefit of this technique compared with open AAA repair.

Endovascular treatment of abdominal aortic aneurysm

BACKGROUND

Endovascular repair of abdominal aortic aneurysm has become widely used. Supporters claim high success rates, few complications and a dramatically reduced hospital stay. However, endoleak, endotension and reports of endoprosthesis rupture are causes of concern.

METHODS

A Medline search was undertaken to identify articles on endovascular repair of abdominal aortic aneurysm. Additional papers were identified by manual scanning of the references from key articles.

RESULTS AND CONCLUSION

Endoleak is a potentially serious complication of the endovascular technique and occurs in a significant proportion of patients. It is still not possible to judge whether the presence of an endoleak alone signifies failure of treatment, and the long-term durability of prosthetic covered stents is unknown. However, endovascular repair does appear to confer a degree of protection from rupture although patients must be advised of the need for life-long imaging surveillance and, perhaps, further intervention.

Variability of maximal aortic aneurysm diameter measurements on CT scan: significance and methods to minimize

OBJECTIVES

We noted substantial differences when measuring repeatedly the same abdominal aortic aneurysm (AAA) on the same computed tomography (CT) scan. This study quantitated this variability, and methods to minimize it were developed.

METHODS

The CT maximal diameter of 25 AAAs was measured by eight experienced observers, including six vascular surgeons and two radiologists, using two methods: an unstandardized protocol, and a standardized protocol using fine calipers to carefully measure the largest diameter perpendicular to the estimated aneurysm centerline, from outer aneurysm wall to outer wall. The average measurement difference between observers was calculated for each method. The average difference between each observer's measurement and the official radiology report value was also calculated. Agreement between the two measurement methods was assessed with Bland-Altman plots.

RESULTS

The difference in maximal diameter measurements between each observer averaged 4.0 +/- 5.1 mm (range, 0.0-35.0 mm) with the unstandardized method. The mean measurement difference with the standardized protocol was significantly lower, and averaged 2.8 +/- 4.4 mm (range, 0.0-26.0 mm; P<.05). Measurements taken from the official radiology report differed from each of the observer's standardized measurement by an average of 5.0 +/- 6.3 mm (range, 0.0-28.0 mm). This difference was similar for both the unstandardized and standardized methods. Bland-Altman plots confirmed the wide variation of the maximal diameter measurements when the unstandardized method was compared with the standardized method (95% confidence interval, -9-9 mm).

CONCLUSIONS

Routine CT maximal diameter measurement of AAAs can have substantial interobserver variability. Standardized measurement protocols can decrease, but not eliminate, this measurement variability. Thus apparent size changes based on CT measurements may represent measurement artifact rather than actual aneurysm growth or shrinkage, particularly when a standardized system is not used.

Type II endoleak after endovascular abdominal aortic aneurysm repair: a conservative approach with selective intervention is safe and cost-effective

OBJECTIVES

The conservative versus therapeutic approach to type II endoleak after endovascular repair of abdominal aortic aneurysm (EVAR) has been controversial. The purpose of this study was to evaluate the safety and cost-effectiveness of the conservative approach of embolizing type II endoleak only when persistent for more than 6 months and associated with aneurysm sac growth of 5 mm or more.

METHODS

Data for 486 consecutive patients who underwent EVAR were analyzed for incidence and outcome of type II endoleaks. Spiral computed tomography (CT) scans were reviewed, and patient outcome was evaluated at either office visit or telephone contact. Patients with new or late-appearing type II endoleak were evaluated with spiral CT at 6-month intervals to evaluate both persistence of the endoleak and size of the aneurysm sac. Persistent (>or=6 months) type II endoleak and aneurysm sac growth of 5 mm or greater were treated with either translumbar glue or coil embolization of the lumbar source, or transarterial coil embolization of the inferior mesenteric artery.

RESULTS

Type II endoleaks were detected in 90 (18.5%) patients. With a mean follow-up of 21.7 +/- 16 months, only 35 (7.2%) patients had type II endoleak that persisted for 6 months or longer. Aneurysm sac enlargement was noted in 5 patients, representing 1% of the total series. All 5 patients underwent successful translumbar sac embolization (n = 4) or transarterial inferior mesenteric artery embolization (n = 4) at a mean follow-up of 18.2 +/- 8.0 months, with no recurrence or aneurysm sac growth. No patient with treated or untreated type II endoleak has had rupture of the aneurysm. The mean global cost for treatment of persistent type II endoleak associated with aneurysm sac growth was US dollars 6695.50 (hospital cost plus physician reimbursement). Treatment in the 30 patients with persistent type II endoleak but no aneurysm sac growth would have represented an additional cost of US dollars 200000 or more. The presence or absence of a type II endoleak did not affect survival (78% vs 73%) at 48 months.

CONCLUSIONS

Selective intervention to treat type II endoleak that persists for 6 months and is associated with aneurysm enlargement seems to be both safe and cost-effective. Longer follow-up will determine whether this conservative approach to management of type II endoleak is the standard of care.

A Canine Model for Studying Endoleak after Endovascular Aneurysm Repair

PURPOSE

The aim of this study was to create an animal model of endoleak after stent-graft placement for abdominal aortic aneurysm (AAA) in which a large aneurysmal sac would be preserved for the testing of techniques for its percutaneous occlusion.

MATERIALS AND METHODS

Infrarenal AAAs were created in nine dogs by anastomosis of an isolated segment of the inferior vena cava to the right side of the abdominal aorta in combination with a large anterior patch from the external jugular vein. One hour later, animals underwent percutaneous implantation of polytetrafluoroethylene-covered Z stent endografts with three 3-mm-diameter holes through the fabric. Aortograms were obtained before and after surgery, after endograft placement, and at the time of animal sacrifice at 1 week or 1, 2, 3, or 6 months. Pressures within the aorta and the aneurysm sac were recorded before animal sacrifice. Gross and histologic evaluations of the specimens were then carried out.

RESULTS

Immediately after endograft placement, all nine animals had artificial type III endoleaks with angiographic filling of lumbar arteries and veins. One animal died of surgical complications within 2 days of surgery and is not included in our data analysis. One aneurysm ruptured at 1 week. At completion of the study, six endografts were patent and two were occluded. The aneurysm sac had enlarged by approximately 50% in seven animals. At follow-up, type I endoleak was present in three animals, type II endoleak was present in three, and the artificial type III endoleak was present in all six animals with patent endografts. The pressure differential between aorta and aneurysm sac was 36 mm Hg, with a mean aortic pressure of 87 mm Hg +/- 13.3 and a mean aneurysmal sac pressure of 51 mm Hg +/- 28.1. The aneurysmal sac exhibited early thrombus formation at 1 week, which progressed to complete thrombosis in 1-6 months.

CONCLUSIONS

The model is technically feasible but would be useful in testing occlusive techniques for residual aneurysm sacs only in the acute phase after endograft placement. It would be not reliable for chronic evaluation because of rapidly progressive thrombosis in most aneurysm sacs and occasional complete thrombosis of the AAA and endograft.

Significance of endotension, endoleak, and aneurysm pulsatility after endovascular repair

OBJECTIVE

The lack of aneurysm pulsatility after endovascular aneurysm repair (EVAR) is deemed by some an important guide to the effectiveness of exclusion. However, factors that contribute to aneurysm pulsatility after EVAR have not been elucidated. This study quantitatively analyzed the effects of systemic pressure, aneurysm sac pressure, endoleak, branch outflow from aneurysm sac, and intra-sac thrombus on aneurysm pulsatility after EVAR.

METHODS

In an ex vivo model, an artificial aneurysm sac was incorporated within a mock circulation comprised of rubber tubing and a pulsatile pump. The aneurysm sac was then completely excluded from the circulatory circuit with two types of stent-grafts, ie, supported and unsupported, and heparinized canine blood was circulated. Systemic circulation and aneurysm sac pressure was recorded in the absence and presence of endoleaks, and simulated open and closed lumbar branch outflow from the aneurysm sac. The aneurysm sac was then filled with organized human thrombus, and all pressure measurements were repeated. Two observers blinded to the above-mentioned variables independently evaluated aneurysm sac pulsatility with palpation in five separate experiments. Analysis of variance was performed, with significance accepted at P =.05.

RESULTS

Systemic pressure was simulated in the artificial circulation to range from 100/60 to 180/60 mm Hg. Regardless of the simulated lumbar branch outflow from the aneurysm, sac pressure was directly related to the presence of endoleak (P <.001). Aneurysm sac pulsatility was present only when the lumbar branch outflow was patent and not dependent on sac pressures. Aneurysm sac thrombosis or type of stent-graft did not influence sac pressure and pulsatility.

CONCLUSIONS

In this model, after EVAR pulsatility depends on aneurysm sac outflow, regardless of endoleak, sac thrombosis, sac pressure, or stent-graft. Furthermore, persistent pulsatility does not predict systemic intra-sac pressure, nor does lack of pulsatility reflect freedom of the aneurysm sac from systemic pressurization. This ex vivo model suggests that aneurysm pulsatility is an unreliable guide for predicting aneurysm sac pressurization after EVAR. Other diagnostic methods must be used to assess successful aneurysm exclusion.

Controversies in the management of type II "branch" endoleaks following endovascular abdominal aortic aneurysm repair

Successful endovascular aortic aneurysm repair (EVAR) is often defined as complete exclusion of blood flow within the aneurysm sac. Perigraft flow, also known as endoleak, is the most common complication following EVAR. Attachment site related endoleaks (type I) are generally considered to warrant some form of intervention due to the belief that they represent a risk for future rupture. Management of type II endoleaks, also known as branch or collateral endoleaks, is more controversial. Some advocate a policy of watchful-waiting whereas others treat all type II endoleaks as soon as they are discovered. The following review explores the controversies pertaining to the management, diagnosis and surveillance imaging, and treatment of type II endoleaks.

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.

Imaging of aortic stent-grafts and endoleaks

Although the technical success of stent-graft implantation is established and relatively safe, data on the long-term safety and efficacy of endovascular repair are just emerging. Because several late complications of aortic stent-graft placement have been observed, life-long follow-up remains essential. Imaging methods form an integral part of every stage of endovascular aortic aneurysm repair. The current imaging strategy should include initial plain films, CT angiography, and color-coded Duplex sonography. Plain films are an excellent means to detect migration, angulation, kinking, and structural changes of the stent mesh, including material fatigue, at follow-up. Helical CT angiography is considered a potentially revolutionary method for the noninvasive complete postprocedural assessment of aortic sten-grafting. Current data justify the use of biphasic C angiography as the postprocedural imaging technique of choice in most patients [118]. Ultrasound offers the advantages of low cost and lack of radiation exposure. High-quality ultrasound reliably excludes endoleaks in patients after stent-grafting of AAAs. There is a substantial variability, however, in measuring the diameter of aneurysm sacs; thus, confirmation using an alternative study is prudent in cases that demonstrate a significant change in size during follow-up. MR angiography serves as an attractive alternative to CT angiography in patients with impaired renal function or known allergic reaction to iodinated contrast media. With current techniques, the visualization of aortic stent-grafts (with the exception of stainless-steel-based devices) is sufficient with MR angiography. There is evidence that MR imaging is superior to CT angiography in detecting small type 2 endoleaks or for excluding retrograde perfusion in patients with suspected endotension. The role of diagnostic catheter angiography is limited to assessment of vascular pathways in equivocal cases or for suspected endotension. Currently, a consensus view about postprocedural management after aortic stent-graft implantation is lacking. The authors propose performing a baseline CT angiography at discharge and a biphasic CT angiography and Duplex ultrasound scan at three months. In patients with no evidence of an endoleak, CT angiography, plain film and Duplex sonography (abdomen) should be repeated every year after endovascular repair. If an endoleak is present at follow-up, immediate appropriate treatment should be initiated.

Ruptured abdominal aortic aneurysm after endovascular repair

OBJECTIVE

The purpose of this study was to present the experience with aneurysm rupture after deployment of Guidant/EVT (Guidant) endografts and review previously reported cases with other devices.

METHODS

Records from Guidant/EVT clinical trials and postmarket approval databases from February 1993 to August 2000 were analyzed to identify patients with rupture and to extract pertinent data. Previously reported cases were obtained with a Medline search.

RESULTS

Seven ruptures were found with Guidant/EVT devices. Five of these occurred among the 686 patients in US Food and Drug Administration protocols (group I) who were followed for a mean of 41.8 +/- 21.9 months and limited to the subgroup of 93 first generation tube endografts. Two ruptures occurred in group II (3260 patients after market approval with limited follow-up), specifically in the subgroup of 166 patients who underwent treatment with second generation tube grafts. No ruptures were found in patients with bifurcation or unilateral iliac implants followed for a mean of 37.5 months. All ruptures were caused by distal aortic type I endoleaks on the basis of attachment system fractures (first generation devices only), aortic neck dilatations, persistent primary endoleaks, migration, overlooked imaging abnormalities, refused reintervention, and poor patient selection. The mortality rate was 57% (4/7) overall and was 50% for surgical repair (3/6). A literature search identified 40 additional ruptures related to other devices, for a total of 47. All 44 that were documented with adequate data were caused by endoleaks (26 type I, 2 type II, 11 type III, and 5 source not reported). Other contributing factors were graft module separation and graft wall deterioration. The overall mortality rate for the combined series was 50%, with an operative mortality rate of 41%.

CONCLUSION

Postendograft AAA rupture is infrequent, although the true incidence rate is unclear because of inadequate follow-up of individual device designs. Tube endografts should be limited to the rare patient with ideal anatomy, no other alternatives, and at high risk for standard open repair. Prevention of aneurysm rupture requires long-term surveillance with attention to subtle imaging abnormalities and the establishment of reliable follow-up protocols for specific devices. The outcome of postendograft aneurysm rupture is similar to that of rupture without prior endograft therapy.

Potential impact of therapeutic warfarin treatment on type II endoleaks and sac shrinkage rates on midterm follow-up examination

OBJECTIVE

Successful endovascular aortic aneurysm repair depends on exclusion and spontaneous thrombosis of the aneurysm sac. The need for chronic postoperative anticoagulation therapy could limit the applicability of this technology with delay or prevention of sac thrombosis resulting in endoleak formation and altered remodeling of the aneurysm sac. The purpose of this study was the determination of whether chronic therapeutic anticoagulation therapy with warfarin was associated with an increased incidence rate of early or delayed postoperative endoleaks or altered rates of reduction in aneurysm sac maximum diameter.

METHODS

Two hundred thirty-two consecutive patients underwent abdominal aortic endografting during a 32-month period. The data were recorded prospectively with a current mean follow-up period of 18 months. The patients with endoleaks identified with 30-day postoperative computed tomographic scan angiograms subsequently underwent selective arteriography to characterize the source. The patients who underwent chronic warfarin therapy that resulted in a therapeutic internationalized normalized ratio comprised the study group. The control group was defined as all the patients with healthy coagulation profiles.

RESULTS

Thirty-six patients (15%) were undergoing warfarin therapy after surgery, and their conditions were chronically maintained with a therapeutic international normalized ratio. Forty-three patients (18%) had endoleaks on 30-day computed tomographic scan angiographic results. There were 39 patients with type II endoleaks and four patients with type I endoleaks. None of the type I endoleaks occurred in patients who were undergoing warfarin therapy, and all endoleaks were repaired with either proximal or distal covered extensions. At 30 days, seven patients (19.4%) undergoing chronic warfarin therapy had type II endoleaks as compared with 36 controls (18.4%; P =.798). Four patients had delayed type II endoleaks develop, two in the control group and two in the warfarin group (P =.3). Ten control individuals (31%) had spontaneous resolution of type II endoleaks develop, whereas spontaneous endoleak thrombosis was not observed in the warfarin group (P =.33). Aneurysm sac remodeling assessed with mean percent reduction in maximum sac diameter at 12 months revealed a statistical difference between the control group (17.5%) and the warfarin group (7.6%; P =.04).

CONCLUSION

Warfarin treatment is not associated with an increase in the incidence rate of early or delayed postoperative endoleaks. However, the rate of reduction in maximum aneurysm sac diameter after aortic endografting is slower in patients who undergo therapeutic warfarin therapy at 1-year follow-up examination, a statistically significant difference from the control group. In addition, type II endoleaks may be less likely to undergo spontaneous thrombosis in patients who undergo warfarin therapy.

Are type II (branch vessel) endoleaks really benign?

The natural history and clinical significance of type II or branch vessel endoleaks following endovascular aortic aneurysm (AAA) repair remain unclear. Some investigators have suggested that these endoleaks have a benign course and outcome and that they can be safely observed. The purpose of this study was to document the natural history and outcome of all type II endoleaks that have occurred following endovascular AAA repair at our institution. A review of a prospectively compiled database of all endovascular AAA repairs performed at our institution was performed. From this review, we determined that type II endoleaks appear to have a relatively benign course, with a reasonable chance of spontaneously sealing within a 2-year period. No cases of rupture or aneurysm enlargement were documented in patients with open type II leaks. However, almost one-third of the patients did not manifest a type II leak until after their initial CT scan. The implications of such a "delayed" leak are unclear. Careful follow-up remains mandatory in patients with type II endoleaks to better define outcome.

Pressure measurements in closed aneurysmal sac during abdominal aortic aneurysm resection

PURPOSE

This study determined the relationship between closed aneurysmal sac pressure (ASP) and mean blood pressure (BP) during open abdominal aortic aneurysm (AAA) resection and evaluated the contribution of inferior mesenteric and lumbar artery blood flow to ASP after proximal and distal clamping.

METHODS

We measured ASP after proximal and distal clamping by placing an 18-gauge needle connected to a BP transducer into the excluded aneurysmal sac in 25 consecutive patients from April 1999 to August 2000. Simultaneous measurement of the mean systemic BP was also recorded. The ratio of ASP to mean BP in relation to the number of actively bleeding lumbar arteries (N-LA), diameter of the AAA (D-Cm), and volume of the thrombus in the AAA (Vol-TA) were recorded.

RESULTS

The mean ASP was 43.32 +/- 15.19 mm Hg, with an ASP to mean BP ratio of 0.47 +/- 0.15. The N-LA in the closed aneurysmal sac ranged from 0 to 6 (mean, 3.4 +/- 1.78). The D-Cm as determined by means of computed tomography (CT) scan of the aorta ranged from 5 to 8 cm in its largest anteroposterior/transverse diameter. The average Vol-TA was 6.15 +/- 4.49 mL. Inferior mesenteric artery blood flow contributed to ASP in three patients (12%). There was no correlation between ASP to mean BP ratios and the N-LA (P =.127), D-Cm (P =.882), or Vol-TA (P =.252).

CONCLUSION

Closed ASP and ASP ratios are highly variable and do not correlate with N-LA, D-Cm, or the Vol-TA.

Prospective evaluation of magnetic resonance imaging after endovascular treatment of infrarenal aortic aneurysms

OBJECTIVES

to evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) in the detection of type II endoleaks during follow-up after endovascular treatment of intra-renal aortic aneurysms.

DESIGN

prospective study.

MATERIAL AND METHODS

between March 1996 and November 1999, 31 patients with infra-renal aortic aneurysms who underwent stentgraft implantation were followed with helical CT and MRI, including magnetic resonance angiography (MRA), at 1 and 6 months after the procedure. Arteriography was performed between 6 and 12 months after intervention. The parameters studied included the change in the maximum anteroposterior and transverse diameters, the nature of the signal on T1 and T2 weighted sequences (homogeneous vs heterogeneous), the presence or absence of Gadolinium uptake on MRI or of contrast uptake on helical CT (early and late phases) in the sac of the aneurysm. On MRA, stentgraft patency and endoleak detection were studied.

RESULTS

arteriography demonstrated an endoleak in 19 patients (18 type II, and 1 type I endoleak). MRI at 6 months detected 18/19 endoleaks on T1 weighted sequences after injection of Gadoliniumj; there were 2 false positives. MRA sequences confirmed stentgraft patency in all patients, but did not diagnose type II endoleaks. Helical CT (late phase) at 6 months detected 10/19 endoleaks; there was 1 false positive. The sensitivity of MRI after injection of Gadolinium and of helical CT for the detection of type II endoleaks were 94% and 50% (p=0.003) respectively. The mean maximal anteroposterior and transverse diameters were similar on MRI and on helical CT at 1 month and at 6 months.

CONCLUSION

MRI after injection of Gadolinium is more sensitive than helical CT in the detection of type II endoleaks after stentgraft implantation. Its more widespread use may permit earlier intervention in such patients.

Hypogastric artery aneurysm rupture after endovascular graft exclusion with shrinkage of the aneurysm: significance of endotension from a "virtual," or thrombosed type II endoleak

Type II endoleaks, resulting from retrograde branch flow, after endovascular graft aneurysm exclusion are considered benign because they usually thrombose and are commonly associated with stable or shrinking aneurysm sacs. We report a hypogastric artery aneurysm rupture from endotension from an undetected, thrombosed Type II endoleak, associated with sac shrinkage. The patient had undergone an endovascular graft repair of a 4-cm right common iliac artery and 9-cm hypogastric artery aneurysm with distal hypogastric artery coil embolization. Serial computed tomography scans revealed no endoleak and a hypogastric aneurysm thrombosis with shrinkage. Eighteen months later, the aneurysm ruptured as a result of pressurization from backbleeding, patent branches.

Diagnosis and treatment of type II endoleak after stent placement for exclusion of an abdominal aortic aneurysm

After endovascular treatment of AAA, regular clinical and radiologic surveillance is necessary for early diagnosis and treatment of mid-term and long-term complications. The purpose of this report was to evaluate the efficacy of magnetic resonance imaging (MRI) in screening for type II endoleaks and assessing the results of treatment by embolization. From March 1996 to November 1999, 64 patients with uncomplicated infrarenal abdominal aortic aneurysm (AAA) were treated by endovascular exclusion with a covered aortic stent. Radiological surveillance included plain abdominal roentgenogram (PAR), CT scan, and pelvioabdominal MRI at 1 month, 3 months, 6 months, and every 6 months thereafter. Arteriography was performed routinely after 1 year or sooner if an endoleak was suspected. Based on the results of this study, MRI seems to be more sensitive than CT scanning for detection of type II endoleaks. The negative predictive value of MRI is also better. In this series, all endoleaks were treated by embolization. In most cases, the maximum transverse diameter and maximum anteroposterior diameter decreased after embolization. Further follow-up will be necessary to confirm these findings.

Totally laparoscopic abdominal aortic aneurysm repair

Abdominal aortic aneurysm (AAA) resection is a major surgical procedure performed frequently. As a minimal access procedure, laparoscopy has been shown in the field of general surgery to improve a patient's postoperative well-being and to shorten hospital stay. The same benefits could be expected from a laparoscopic approach for AAA repair. We report what we believe to be the first totally laparoscopic AAA repair performed according to the principles of endoaneurysmorrhaphy.

Endoluminal stent grafts in the management of infrarenal abdominal aortic aneurysms: a realistic assessment

OBJECTIVES

transfemoral endoluminal aortic management (TEAM) is technically feasible in the treatment of infrarenal abdominal aortic aneurysms but its advantage over conventional repair is unproved. We report our initial experience, learning curve and technical difficulties encountered during the process of establishing this novel technique in our institute.

MATERIAL AND METHODS

over a 3-year period 400 cases of abdominal aortic aneurysms were reviewed; only 58 cases (15%) were suitable for endovascular repair under our TEAM protocol and 36 (9%) were offered endovascular intervention. They were mainly high-risk patients (85% ASA III and IV) with a mean age of 72 years. Thirty-three bifurcated grafts, two straight tube grafts and one aorto mono-iliac graft were deployed. We oversized the graft by 15-20% to the diameter of the aortic neck and both common iliac arteries.

RESULTS

two cases (6%-95% CI: 1-19%) had on-table conversion because of ruptured common iliac arteries. Peri-operatively there were two deaths from multi-organ failure. Transient renal failure occurred in two patients and three patients (9%) suffered a non-fatal myocardial infarction. Sixteen percent of patients had a groin wound problem. The mean hospital stay was 7 days. Five minor endoleaks (15%) were identified and sealed at 30 days. One secondary endoleak was identified at 18 months because of a patent juxta-renal lumbar artery. No secondary cuffs or extensions were used. Mean follow-up was 29 months and all grafts remained patent. The technical, clinical, continuous and secondary success rates were 78%, 91%, 89% and 91% respectively with TEAM.

CONCLUSION

endovascular training, patient selection and learning curve impose an impact on the final outcome. Until a reliable hard point is reached so that endovascular repair could be exercised in routine practice, the use of TEAM must be questioned in high-risk patients, and should be performed under clinical trial conditions using strict selection criteria.

Incidence and risk factors of late rupture, conversion, and death after endovascular repair of infrarenal aortic aneurysms: the EUROSTAR experience. European Collaborators on Stent/graft techniques for aortic aneurysm repair

OBJECTIVE

The EUROSTAR (European Collaborators on Stent/graft techniques for aortic aneurysm repair) Registry was established in 1996 to collect data on the outcome of treatment of patients with infrarenal aortic aneurysms with endovascular repair. To date, 88 European centers of vascular surgery have contributed. The purpose of the study was to evaluate the results of this treatment in the medium term (up to 4 years) according to the analysis of "hard" or primary end points of rupture, late conversion, and death.

PATIENTS AND METHODS

Patients with aortic aneurysms suitable for endovascular aneurysm repair were notified to the EUROSTAR Data Registry Centre before treatment to eliminate bias due to selective reporting. The following information was collected on all patients: (1) demographic details and the anatomic characteristics of their aneurysms, (2) details of the endovascular device used, (3) complications encountered during the procedure and the immediate outcome, (4) results of contrast enhanced computed tomographic imaging at 3, 6, 12, and 18 months after operation and at yearly intervals thereafter, and (5) all adverse events. Life table analysis was performed to determine the cumulative rates of (1) death from all causes, (2) rupture, and (3) late conversion to open repair. Risk factors for rupture and late conversion were identified through regression analysis.

RESULTS

By March 2000, 2464 patients had been registered, and their mean duration of follow-up was 12.19 months (SD, 12.3 months). There were 14 patients with confirmed rupture of their aneurysms. The cumulative rate (risk) of rupture was approximately 1% per year. Emergency surgery was undertaken in 12 (86%) patients, of whom five (41.6%) survived. Two patients who were not treated surgically also died, which resulted in an overall death rate of 64.5% (9/14) of the patients. Significant risk factors for rupture were proximal type I endoleak (P =.001), midgraft (type III) endoleak (P =.001), graft migration (P =.001), and postoperative kinking of the endograft (P =.001). Forty-one patients underwent late conversion to open repair with a perioperative mortality rate of 24.4% (10/41). The cumulative rate (risk) of late conversion was approximately 2.1% per year. Risk factors (indications) for late conversion were proximal type I endoleak (P =. 001), midgraft (type III) endoleak (P =.001), type II endoleak (P =. 003), graft migration (P =.001), graft kinking (P =.001), and distal type I endoleak (P =.001).

CONCLUSIONS

Endovascular repair of infrarenal aortic aneurysms with the first- and second-generation devices that predominated in this study was associated with a risk of late failure, according to an analysis of observed hard end points of 3% per year. Action taken to address the risk factors identified by the study may improve results in the future.

Life-table analysis of primary and assisted success following endoluminal repair of abdominal aortic aneurysms: the role of supplementary endovascular intervention in improving outcome

AIM

the aim of this study was to analyse the effect of supplementary endovascular intervention on the outcome of primary endoluminal repair of abdominal aortic aneurysm (AAA).

METHODS

between May 1992 and December 1998, 266 patients underwent endoluminal repair of AAA. Minimum period of follow-up was 6 months. Those patients in whom the endoprosthesis could not be deployed were converted to open repair at the primary operation. Patients developing an early endoleak, within 31 days, were treated by a period of observation and secondary endovascular intervention in persistent cases. Patients developing a late endoleak were treated similarly, without a period of observation. Outcome was analysed by the life-table method. Primary success was defined as exclusion of the aneurysm from the circulation resulting from the original operation. Assisted success occurred when aneurysms with endoleaks became excluded from the circulation as a result of supplementary endovascular intervention.

RESULTS

endoluminal repair failed in 17 patients requiring conversion to open repair at the original operation. Supplementary endovascular intervention was undertaken in 26 patients, with early endoleaks (n=6) and late endoleaks (n=20). Interventions involved deployment of secondary endoluminal grafts within the primary grafts (n=22), and coil embolisation (n=4). Successful exclusion of the aneurysm sac was achieved in 22 of 26 (85%) patients undergoing supplementary endovascular procedures. Conditional cumulative incidence of primary graft failure and secondary graft failure in the presence of all-cause mortality at 6 years was 47% and 25% respectively.

CONCLUSIONS

supplementary endovascular intervention is an important adjunct to endoluminal AAA repair with the potential to improve outcome and avoid conversion to open repair. Successful supplementary endovascular intervention was achieved in 85% of patients in whom it was attempted. Life-table analysis showed these supplementary procedures to be durable in the long term.