The value of late computed tomographic scanning in identification of vascular abnormalities after abdominal aortic aneurysm repair

PURPOSE: The purpose of this study was to determine the prevalence of late arterial abnormalities after aortic aneurysm repair and thus to suggest a routine for postoperative radiologic follow-up examination and to establish reference criteria for endovascular repair. METHODS: Computed tomographic (CT) scan follow-up examination was obtained at 8 to 9 years after abdominal aortic aneurysm (AAA) repair on a cohort of patients enrolled in the Canadian Aneurysm Study. The original registry consisted of 680 patients who underwent repair of nonruptured AAA. When the request for CT scan follow-up examination was sent in 1994, 251 patients were alive and potentially available for CT scan follow-up examination and 94 patients agreed to undergo abdominal and thoracic CT scanning procedures. Each scan was interpreted independently by two vascular radiologists. RESULTS: For analysis, the aorta was divided into five defined segments and an aneurysm was defined as a more than 50% enlargement from the expected normal value as defined in the reporting standards for aneurysms. With this strict definition, 64.9% of patients had aneurysmal dilatation and the abnormality was considered as a possible indication for surgical repair in 13.8%. Of the 39 patients who underwent initial repair with a tube graft, 12 (30.8%) were found to have an iliac aneurysm and six of these aneurysms (15.4%) were of possible surgical significance. Graft dilatation was observed from the time of operation (median graft size of 18 mm) to a median size of 22 mm as measured by means of CT scanning at follow-up examination. Fluid or thrombus was seen around the graft in 28% of the cases, and bowel was believed to be intimately associated with the graft in 7%. CONCLUSION: Late follow-up CT scans after AAA repair often show vascular abnormalities. Most of these abnormalities are not clinically significant, but, in 13.8% of patients, the thoracic or abdominal aortic segment was aneurysmal and, in 15.4% of patients who underwent tube graft placement, one of the iliac arteries was significantly abnormal to warrant consideration for surgical repair. On the basis of these findings, a routine CT follow-up examination after 5 years is recommended. This study provides a population-based study for comparison with the results of endovascular repair.     

Large diameter expanded polytetrafluoroethylene grafts for infrarenal aortic aneurysm surgery

The performance of an expanded polytetrafluoroethylene (ePTFE) graft used for aortic aneurysm replacement was evaluated. ePTFE grafts were implanted in 241 patients undergoing infrarenal abdominal aortic aneurysm (AAA) repair. Sixty patients were operated as emergencies for aneurysm rupture and 181 electively. One hundred and fourteen bifurcated and 127 tube grafts were inserted. The transperitoneal approach was used in 64 cases and the remainder were placed using a retroperitoneal approach. There was a one-month mortality of 2.8% in elective and 20% in emergency cases. Median follow-up was 26 months. Specific graft complications included one infected graft resulting in a graft-enteric fistula. No graft rupture, degeneration, dilatation, pseudoaneurysm or late graft limb thromboses were observed in up to 7 years of follow-up. The aortic ePTFE prosthesis demonstrated satisfactory performance over the period studied.     

Open infrarenal abdominal aortic aneurysm repair: the Cleveland Clinic experience from 1989 to 1998

PURPOSE: The purpose of this study was to determine the safety and durability of traditional surgical treatment for asymptomatic infrarenal abdominal aortic aneurysms (AAAs) in a large series of patients who underwent open operations during the decade preceding the commercial availability of stent graft devices for endovascular AAA repair. METHODS: From 1989 to 1998, 1135 consecutive patients (985 men [87%], 150 women; mean age, 70 +/- 7 years) underwent elective graft replacement of infrarenal AAA. Computerized perioperative data have been supplemented with a retrospective review of hospital charts/outpatient records and a telephone canvass to calculate survival rates and the incidence rate of subsequent graft-related complications. Seventy-four patients (6.5%) were lost during a median follow-up period of 57 months for the entire series. RESULTS: The 30-day mortality rate was 1.2%. The hospital course was completely uneventful for 939 patients (83%), and the median length of stay for all patients was 8 days. A total of 196 patients had single (n = 150; 13%) or multiple (n = 46; 4%) postoperative complications, which were more likely to occur in men (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.1 to 5.2) and in patients with a history of congestive heart failure (OR, 3.7; 95% CI, 1.7 to 7.8), chronic pulmonary disease (OR, 1.9; 95% CI, 1.2 to 2.9), or renal insufficiency (OR, 2.5; 95% CI, 1.3 to 4.7). Kaplan-Meier method survival rate estimates were 75% at 5 years and 49% at 10 years. As was the case with early complications, the long-term mortality rate primarily was influenced by age of more than 75 years (risk ratio [RR], 2.2; 95% CI, 1.7 to 2.8) or previous history of congestive heart failure (RR, 2.1; 95% CI, 1.3 to 3.4), chronic pulmonary disease (RR, 1.5; 95% CI, 1.2 to 2.0), or renal insufficiency (RR, 3.2; 95% CI, 2.2 to 4.6). Of the 1047 patients who survived their operations and remained available for follow-up study, only four (0.4%) have had late complications that were related to their aortic replacement grafts. CONCLUSION: These results reconfirm the exemplary success of open infrarenal AAA repair. The future of endovascular AAA repair is exceedingly bright, but until the long-term outcome of the current generation of stent grafts is adequately documented, their use should be justified by the presence of serious surgical risk factors.     

Prosthetic stent graft infection after endovascular abdominal aortic aneurysm repair

OBJECTIVE: The purpose of this report is to discuss the incidence, diagnosis, and management of stent graft infections after endovascular aneurysm repair (EVAR). METHODS: Data were collected from the hospital database and medical case notes for all patients with infected endografts after elective or emergency EVAR for abdominal aortic aneurysm (AAA) during the last 8 years in two university teaching hospitals in Northern Ireland. The data included the patient's age, gender, presentation of sepsis, treatment offered, and the ultimate outcome. The diagnosis of graft-related sepsis was established by a combination of investigations including inflammatory markers, labelled white cell scan, computed tomography (CT) scan, microbiology cultures, and postmortem examination. RESULTS: Graft-related septic complications occurred in six of 509 patients, including 433 elective repairs and 76 emergency endografts for ruptured AAA. Two patients presented with left psoas abscess and were treated successfully with extra-anatomic bypass and removal of the infected stent graft. Two more patients presented with infected graft without other evidence of intra-abdominal sepsis: one underwent successful removal of the infected prosthesis with extra-anatomical bypass, and the other was treated conservatively and died of progressively worsening sepsis. The fifth patient presented with unexplained fever and died suddenly, with a postmortem diagnosis of aortoenteric fistula and ruptured aneurysm. The last patient presented with an aortoenteric fistula, was treated conservatively in view of concurrent myelodysplasia, and died of possible aneurysm rupture. CONCLUSION: This report emphasizes the need for continued awareness of potential graft-related septic complications in patients undergoing EVAR of AAA. Attention to detail with regard to sterility and antibiotic prophylaxis during stent grafting and during any secondary interventions is vital in reducing the risk of infection. In addition, early recognition and prompt treatment are essential for a successful outcome.     

Postoperative dilation of knitted Dacron aortic bifurcation graft

Dilation is the most common inherent "failure mode" of knitted Dacron aortic prostheses. However, the incidence of graft failure related to dilation is unknown because of insufficient data regarding the occurrence, degree, and prognostic significance of postoperative alterations in graft size. In 1979 we reported that postoperative ultrasonic examinations in 95 asymptomatic patients, selected at random after aortic surgery, revealed dilation of the aortic portion of knitted Dacron bifurcation grafts. The average follow-up was 33 months, and the mean dilation was 18%. This article provides the results of a later follow-up, averaging 175 months, in 32 patients from the 1979 study. CT scanning, rather than ultrasonic imaging, was used to evaluate all parts of the grafts. CT scans disclosed that the three parts of each graft dilated, but the parts did not always dilate uniformly. Mean percent dilation values for the entire series were aortic portion 67% +/- 38% SD; right limb 77% +/- 66% SD; left limb 54% +/- 26% SD. Maximum percent dilation for any part of the grafts ranged from 26% to 367% with a mean of 94%. At least one part of the grafts dilated 100% or greater in 12 patients. Three patients had generalized and saccular dilation of the aortic portion of the prostheses and an anastomotic aortic aneurysm; one patient had a localized aneurysm in the midportion of the right limb. Three of the latter grafts were replaced with woven Dacron prostheses.     

Long-term surveillance is paramount after implantation of the Vanguard stent-graft for abdominal aortic aneurysms

AIM: The aim of this study was to describe the results and long-term follow-up of the Vanguard endovascular graft for infrarenal abdominal aortic aneurysm (AAA) repair. METHODS: Between February 1997 and October 1999, 76 patients were treated with a median aneurysm diameter of 52 mm (39-90 mm). All were followed up according to the Eurostar criteria. RESULTS: The primary technical success rate was 100%. Perioperative mortality was 1.3%. During follow-up (median 75 months, 6-112 months) 9 aneurysm related deaths occurred. A total of 79 late complications occurred in 45 patients (64%). Complications were noticed more frequently in the group of aneurysms larger than 5.5 cm (P=0.014). Patients who ultimately developed aneurysm rupture after endovascular repair had more postoperative complications compared to the majority who did not rupture their aneurysm. (P=0.001) Secondary interventions were mandatory in 23 patients, surgical conversion in 9. At 72 months this has resulted in an overall survival rate of 57%, an aneurysm rupture free survival of 88%, a conversion free survival of 95%, an endoleak free survival of 83% and a secondary intervention free survival of 82% (Kaplan Maier). CONCLUSION: The importance of life-long strict surveillance of patients treated with a Vanguard endograft was confirmed. Patients with graft-related complications should be treated accordingly.     

True juxta-anastomotic aneurysms in the residual infra-renal abdominal aorta.

INTRODUCTION: abdominal aortic dilatation can occur above the graft following repair of infra-renal abdominal aortic aneurysm (AAA). This study aimed to determine the incidence and possible aetiological associations of recurrent juxta-anastomotic aneurysms following open repair of AAA. METHODS: the diameter of the infra-renal aorta above the graft of 135 patients who had previously undergone open AAA repair was determined using ultrasound. In those where the diameter was greater than 40 mm a CT scan was undertaken. Co-morbid and operative details were determined from the patients and their clinical notes. RESULTS: seven patients had true juxta-anastomotic aneurysms (>40 mm) in the residual infra-renal abdominal aorta, the occurrence of which was associated with tobacco smoking and hypertension. There was no association with other co-morbid factors, surgical operative details or the development of iliac aneurysms (which occurred in 3% of patients). CONCLUSIONS: true juxta-anastomotic aneurysms develop in the residual infra-renal neck of patients following open repair of abdominal aortic aneurysm. Tobacco smoking and hypertension are significant factors associated with the development of these aneurysms. This group of patients may warrant surveillance to prevent aneurysm rupture.     

Endovascular repair of a common iliac artery aneurysm using the Cook Zenith abdominal aortic aneurysm Endovascular Graft Converter

Isolated common iliac artery aneurysm is a rare condition that is treated aggressively because of its high risk of rupture. Endovascular abdominal aortic aneurysm (AAA) repair has recently been extended to the clinical management of the iliac artery aneurysm. Stent grafts have been used successfully to exclude iliac artery aneurysms. Successful graft deployment and aneurysm exclusion require adequate seal and fixation at the proximal and distal attachment sites. This article presents a high-risk surgical patient whose 6.8-cm-diameter iliac artery aneurysm was repaired with a Zenith AAA Endovascular Graft Converter (Cook, Bloomington, Indiana). This device is normally used to convert an aortobiiliac endograft to an aortouniiliac endograft during AAA repair. The tapered 80-mm-long graft has diameters of 24 mm proximally and 12 mm distally. Completion arteriogram demonstrated exclusion of the iliac artery aneurysm with no evidence of endoleak. No postoperative complications occurred. No endoleak was seen on the follow-up abdominal computed tomography scan.     

Endovascular repair of early rupture of Dacron aortic graft--two case reports

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

自制国产化支架-移植物腔内治疗腹主动脉瘤的实验研究

目的 探讨自制国产化支架、移植物在治疗犬腹主动脉瘤中的作用。方法 以国产镍钛合金丝纺织成网状管型支架,外套以国产真丝涤纶交织人造血管,装入导鞘制成支架-移植物系统;用胰蛋白酶灌注犬肾下腹主动脉段形成动脉瘤模型;用血管腔内技术将支架-移植物置入腹主动脉内,隔绝血流分别于第1周、1个月、3个月和6个月末观察通畅度及新生内膜生长。结果 20条模型犬接受手术,成功19条,支架置入后能充分展开并恢复形状,1个月末,支架内表面90%被新生内膜覆盖,3个月末几达100%,6个月末,79%的支架保持通畅,无移位、内漏等并发症。结论 自制国产化支架、移植物有良好的生物相容性和较高的通畅率,可用于腹主动脉瘤的治疗。     

Perioperative complications and early outcome after endovascular and open surgical repair of abdominal aortic aneurysms

BACKGROUND: Open repair (OR) of abdominal aortic aneurysms (AAAs) is a major surgical procedure with elevated morbidity and a low but definite mortality. Advocates of endovascular repair (EVAR) claim decreased complication rates and outcome equal to OR. METHODS: Data of all patients with infrarenal AAA that was treated electively, both with OR and EVAR, at Mayo Clinic Rochester between December 1, 1999 and December 1, 2001 were retrospectively reviewed. Thirty-day morbidity and mortality and early clinical outcomes were assessed and compared. RESULTS: Three hundred fifty-five patients underwent treatment: 261 patients, including 229 males and 32 females (mean age: 73 years; range: 52 to 90 years) underwent OR, and 94 patients including 85 males and 9 females (mean age: 77 years; range: 61 to 98 years) underwent EVAR (AneuRx: 53, Ancure: 38, Endologix: 3). Median AAA size was 57 mm in both groups. There were more high-risk patients in the EVAR group (27% vs 14%, P =.007). Thirty-day mortality rates were 1.1 % (3/261) for OR and 0 for EVAR (P = NS). Cardiac and pulmonary complications were less frequent after EVAR (11% vs 22%, P =.02, and 3% vs 16%, P =.001, respectively), but graft-related complications were more frequent (13% vs 4%, P =.002). The association between type of repair and cardiac, pulmonary, and graft complications remained statistically significant after adjusting for age, gender, and high-risk status. The multivariate odds ratios (EVAR vs OR) for cardiac, pulmonary, and graft complications were 0.35 (95% confidence interval [CI]: 0.17 to 0.74), 0.14 (95% CI: 0.04 to 0.47), and 3.81 (95% CI: 1.51 to 9.58), respectively. Primary and secondary patency and freedom-from-reintervention rates at 1 year were lower after EVAR (83% vs 98%, P <.001; 96% vs 99%, P =.02; 65% vs 93%, P <.001, respectively). CONCLUSIONS: Both elective OR and EVAR can be performed with low mortality, but cardiac and pulmonary complications are less frequent and less severe after EVAR. The tradeoff of EVAR is a higher rate of graft-related complications, with more reinterventions and a lower graft patency rate at 1 year. These results should be considered before EVAR is offered to patients with AAA.     

Total laparoscopic abdominal aortic aneurysms repair

AIM: The aim of the study was to describe our experience of total laparoscopic abdominal aortic aneurysm (AAA) repair. METHODS: Between February 2002 and September 2004, we performed 49 total laparoscopic AAA repair in 45 men and 4 women. Median age was 73 years (range, 46-85 years). Median aneurysm size was 52 mm (range, 30-95 mm). ASA class of patients was II, III and IV in 16, 32 and 1 cases, respectively. We used the laparoscopic transperitoneal left retrocolic approach in 47 patients. Seven patients were operated via a tranperitoneal left retrorenal approach and one patient via a retroperitoneoscopic approach. RESULTS: We implanted tube grafts and bifurcated grafts in 19 and 30 patients, respectively. Median operative time was 290 min (range, 160-420 min). Median clamping time was 81.5 min (range, 35-230 min). Median blood loss was 1800 cc (range, 300-6900 cc). Mortality was 6.1% (3 patients). In our early experience, two patients died of myocardial infarction. The 3rd death was due to a multiple organ failure. Thirteen major non lethal postoperative complications were observed in 9 patients (18%). Four patients had local/vascular complications, which required reintervention (8%). Nasogastric tube is now removed at the end of procedure. Median duration of ileus, return to general diet, ambulation and hospital stay were 2, 3, 3 and 10 days. With a median follow-up of 19 months (range, 8-39 months), complete recovery with patent graft was observed in 44 patients. Two patients needed a crossover femoral graft for one iliac dissection and one graft limb occlusion. CONCLUSIONS: These results show that total laparoscopic AAA repair is feasible and worthwhile for patients once the learning curve is overcome. It remains technically demanding and a previous training in videoscopic sutures is essential. Initial learning curve in laparoscopic aortic surgery with aortoiliac occlusive lesions is preferable before to begin laparoscopic AAA repair.     

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.     

Predictive factors and clinical consequences of proximal aortic neck dilatation in 230 patients undergoing abdominal aorta aneurysm repair with self-expandable stent-grafts

OBJECTIVE: Several studies have suggested that proximal aortic neck dilatation (AND) is a frequent event after balloon-expandable endografting. Yet few data are available on AND after repair with self-expandable stent grafts. To investigate incidence, predictive factors, and clinical consequences of AND, computed tomography (CT) scans obtained at intervals during follow-up of 230 patients who had undergone endoluminal abdominal aortic aneurysm (AAA) repair with self-expandable stents were reviewed. SUBJECTS: Between April 1997 and March 2001, 318 patients underwent endoluminal AAA repair with a self-expandable endograft at our unit. CT scans obtained at 1 and 12 months after surgery and yearly thereafter were prospectively stored in a computer imaging data base. Two hundred thirty patients were available for minimum 1-year assessment. Two vascular surgeons with tested interobserver agreement reviewed 686 CT scans. Diameter of the proximal aortic neck was measured as the minor axis of the first CT section that contained at least half of the proximal portion of the endograft. For endografts with suprarenal attachment the first scan below the lowest renal artery was considered. Diameter change of 3 mm or more between the CT scan at 1 month and subsequent evaluations was defined as AND. Nine possible independent predictors of AND were analyzed with Cox regression analysis. RESULTS: Median follow-up was 24 months (range, 12-54 months). In 2 patients, AAA ruptured during follow-up. CT scans for 65 patients (28%) showed AND. Thirteen patients with AND (5.6%) underwent repeat intervention, including positioning of the proximal cuff in 8 patients and late conversion to open repair in five patients. Of the nine variables examined with multivariate analysis, only 3, ie, presence of neck circumferential thrombus (hazard ratio [HR], 2.51; 95% confidence interval [CI], 1.26-5.01; P =.008), preoperative proximal neck diameter (HR, 1.21; 95% CI, 1.07-135; P =.001), and preoperative AAA diameter (HR, 1.03; 95% CI, 1.00-1.06; P =.046) were positive independent predictors of AND, whereas the other 6, ie, neck angulation more than 60 degrees, neck length, suprarenal fixation, oversizing more than 15%, endoleak at 30 days, and increased AAA diameter during follow-up, showed no significant correlation. Probability of AND at 48 months was 59 +/- 6.1 at analysis with the Kaplan-Meier method. CONCLUSIONS: AND is a frequent sequela of endoluminal repair in the mid-term. Severe AND developed in a small percentage of our patients, compromising integrity of AAA repair. Patients with large aneurysms and aortic necks and patients with aortic neck circumferential thrombus are at high risk for aortic neck enlargement after endoluminal repair of AAA.     

Late aortic and graft-related events after thoracoabdominal aneurysm repair

PURPOSE: Unlike abdominal aortic aneurysm repair, little information exists regarding aortic-related morbidity (synchronous/metachronous aneurysm or graft-related complications) after thoracoabdominal aneurysm (TAA) repair. This study was performed to define such events and identify factors related to their development. METHODS: Over a 15-year interval, 333 patients underwent TAA repair (type I, n = 90; 27%; type II, n = 59; 18%; type III, n = 118; 35%; and type IV, n = 66; 20%). Late aortic events were defined as aortic disease causing death or necessitating further intervention or graft-related complications (infection, pseudoaneurysm, branch occlusion) after hospital discharge. Variables were assessed for their association with aortic events with Cox proportional hazards regression. RESULTS: In-hospital mortality occurred in 28 patients (8.4%), which left 305 available for follow-up (mean length of follow-up, 26 months; interquartile range, 2.7 to 38.4 months). After TAA repair, aneurysm remained in 60 patients (19.7%; ascending/arch, n = 41; 68.3%; discontinuous infrarenal, n = 12; 20%; contiguous descending, n = 7; 11.7%; contiguous abdominal, n = 4; 6.7%). Events occurred in 33 individuals (10.8%) at 30 +/- 27 months after surgery. Twenty-four patients (73% of events; 7.9% of cohort) had aortic-related events, including another elective aneurysm repair (n = 16), urgent/emergent aneurysm operation (n = 5), acute dissection (n = 2), and atherothrombotic embolization (n = 1). Nine patients (27% of events; 2.9% of cohort) had graft-related incidents, including renovisceral occlusion (n = 5), visceral patch pseudoaneurysm (n = 2), graft infection (n = 2), and graft-esophageal fistula (n = 1). Variables independently predictive of events were female gender (odds ratio [OR], 2.3; P =.03), initial aneurysm rupture (OR, 4.8; P =.04), partial disease resection (OR, 4.2; P =.0008), and expansion of remaining aortic segments on imaging surveillance (OR, 2.5; P =.03). The event-free survival rates were 96% (95% CI, 93% to 98%) and 71% (95% CI, 60% to 83%) at 1 and 5 years. CONCLUSION: Late aortic events occur in at least 10% of patients after TAA repair and are usually the result of native aortic disease in remote (or noncontiguous) aortic segments. Graft-related complications, in particular, degeneration of inclusion anastamoses, are rare. Female gender, original presentation with rupture, and unresected disease identify those at highest risk. These findings verify the anatomic durability of TAA repair and suggest indefinite aortic surveillance is indicated for those at risk of events.     

Duplex ultrasound scanning versus computed tomographic angiography for postoperative evaluation of endovascular abdominal aortic aneurysm repair

Objective: The purpose of this study was to compare duplex ultrasound scanning and computed tomographic (CT) angiography for postoperative imaging and surveillance after endovascular repair of abdominal aortic aneurysm (AAA). Methods: One hundred consecutive patients with AAA underwent endovascular (Medtronic AneuRx, stent graft) aneurysm repair and were imaged with both CT angiography and duplex ultrasound scanning at regular intervals after the procedure. Each imaging modality was evaluated for technical adequacy and for documentation of aneurysm size, endoleak, and graft patency. In concurrent scan pairs, accuracy of duplex scanning was compared with CT. Results: A total of 268 CT scans and 214 duplex scans were obtained at intervals of 1 to 30 months after endovascular aneurysm repair (mean follow-up interval, 9 ± 7 months). All CT scans were technically adequate, and 198 (93%) of 214 duplex scans were technically adequate for the determination of aneurysm size, presence of endoleak, and graft patency. Concurrent (within 7 days of each other) scan pairs were obtained in 166 instances in 76 patients (1-6 per patient). The maximal transverse aneurysm sac diameter measured with both methods correlated closely (r = 0.93; P < .001) without a significant difference on paired analysis. In 92% of scans, measurements were within 5 mm of each other. Diagnosis of endoleak on both examinations correlated closely (P < .001), and compared with CT, duplex scanning had a sensitivity of 81%, a specificity of 95%, a positive predictive value of 94%, and a negative predictive value of 90%. Discordant results occurred in 8% of examinations, and in none of these was the endoleak close to the attachment sites or associated with aneurysm expansion. An endoleak was demonstrated on both tests in all eight patients who had an endoleak judged severe enough to warrant arteriography. Graft patency was documented in each instance, without discrepancy, with both modalities. Conclusions: High-quality duplex ultrasound scanning is comparable to CT angiography for the assessment of aneurysm size, endoleak, and graft patency after endovascular exclusion of AAA. (J Vasc Surg 2000;32:1142-8.)     

Utility of Polyethylene Terephthalate (Dacron) Vascular Grafts for Venous Outflow Reconstruction in Living-Donor Liver Transplantations

BackgroundVenous outflow reconstruction of modified right-lobe liver grafts has been shown to prevent the occurrence of graft congestion and subsequent complications, including graft loss. In the present study, we aimed to investigate the safety and efficacy of Dacron grafts for venous reconstruction in living donor liver transplantation (LDLT).MethodsBetween January 2016 and January 2018, Dacron grafts were used in 148 liver transplants. Of these, 104 patients who had a follow-up computerized tomography (CT) scan were enrolled into the study. A total of 179 outflow hepatic veins including V5, V8, partial middle hepatic vein, and accessory inferior right hepatic veins (IRHV) were reconstructed using synthetic Dacron grafts. Graft patency was evaluated with both intraoperative Doppler ultrasonography following reconstruction, and a follow-up CT was performed on the postoperative day 7 (±1). Retrospective data collection included demographics, parameters for small-for-size (laboratory tests [bilirubin, International Normalized Ratio] and ascites) syndrome, postoperative morbidity, and mortality.ResultsFollow-up CT revealed graft patency in 155 out of 179 (86.6%) vascular grafts. Postoperative seventh-day patency rates for each reconstructed vein were as follows: V5, 87.5% (70/80); V8, 87.7% (50/57); partial middle hepatic vein, 100% (11/11); and IRHV, 77.4% (24/31). No major graft-related complications (early graft dysfunction, graft infection) or graft-related mortality were observed. None of the recipients developed small-for-size syndrome based on laboratory tests and clinical findings.ConclusionsDacron vascular grafts appear as an advantageous and useful alternative for venous outflow reconstruction in LDLT.     

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.     

What Are the Longterm Results of Conventional Open Surgical Repair of Abdominal Aortic Aneurysms ?

Purpose : To determine the longterm results of conventional open surgical repair of abdominal aortic aneurysms (AAAs) and the prevalence of late arterial abnormalities.

Methods : CT scan follow-up was obtained between 8 and 9 years after elective AAA repair on a cohort of patients enrolled in the Canadian Aneurysm Study, a registry that originally consisted of 680 patients. A request for CT follow- up was sent to the responsible surgeon in 1994 when 251 patients were alive and available. Ninety-four of the 251 patients agreed to undergo an abdominal and thoracic CT scan, and each scan was interpreted independently by two vascular radiologists.

Results : The aorta was analysed in five defined segments, and an aneurysm was defined as > 50% enlargement from the expected normal value as defined in the Reporting Standards for Aneurysms. Using this strict definition, 64.9% of patients had an aneurysm, but the abnormality was considered a possible indication for surgical repair in 13.8%. Of the 39 patients who had an initial repair with a tube graft, 12 (30.8%) were found to have an iliac aneurysm and 6 (15.4%) were considered to be of possible surgical significance. The median graft size at the time of operation was 18 mm, which increased to a median size of 22 mm at follow-up. Fluid or thrombus around the graft was observed in 28%, and bowel was intimately associated with the graft in 7%.

Conclusions : The longterm results of conventional open surgical repair is durable. CT scan follow-up between 8 and 9 years postoperatively often demonstrates aortic and iliac abnormalities, but the majority are not clinically significant. On the basis of these findings, a routine CT scan of the abdomen and chest is recommended after 5 years. This study provides a population based study for comparison with the longterm results of endovascular repair.     

Midterm results of the multicenter trial of the powerlink bifurcated system for endovascular aortic aneurysm repair

PURPOSE: We assessed the results of abdominal aortic aneurysm (AAA) repair with the Powerlink bifurcated endovascular graft compared with open AAA repair. METHOD: A prospective controlled multicenter trial of the Powerlink system for endovascular aneurysm repair was conducted at 15 sites as part of a pivotal US Food and Drug Administration trial. Between July 2000 and March 2003, 258 patients (192 test patients, 66 control patients) were enrolled. Stent grafts were oversized by 10% to 20% relative to computed tomography scan (CT)-based diameter measurements. All repairs were performed in the operating room through 1 surgically exposed femoral artery and a contralateral 9F sheath percutaneously placed. Results were assessed with contrast material-enhanced CT scans and plain abdominal x-ray studies at 1, 6, and 12 months, and annually postoperatively. RESULTS: Patients were followed up for a mean of 22 months (median, 24 months). Technical success was achieved in 97.9% of patients, with 4 failed insertions (3 early conversions because of deployment issues, 1 access failure). There were no significant differences in mortality between the Powerlink and control groups, and only 1 death was procedure-related. Blood loss (341 mL vs 1583 mL; P < .0001), operative time (136 minutes vs 222 minutes; P < .0001), intensive care unit stay (0.78 days vs 4.1 days; P < .0001), and hospital length of stay (3.3 days vs 9.5 days; P < .0001) were significantly less in the Powerlink cohort compared with the control group. There were significantly fewer adverse events (myocardial infarction, P = .0131; renal failure, P = .0042; gastrointestinal complications, P = .0125) in the perioperative period in the Powerlink cohort compared with the control group, but in the longer follow-up interval adverse event-free survival was equivalent between groups (P = .456, log-rank test). At the time of the first-month CT scan, endoleaks were noted in 25 patients, yielding a 30-day endoleak rate of 22.7%. Type II endoleaks predominated, and there were no type III or IV endoleaks. Secondary procedures were performed in 19 patients (10%), for treatment of endoleak (n = 10), limb obstruction (n = 7), and other causes (n = 2). There were 3 graft migrations (2.2%), 1 of which resulted in an endoleak. There were no ruptures, graft fabric defects, or wire fractures. Significant reduction in mean AAA diameter and volume was noted at every follow-up interval. Increase in AAA diameter was noted in only 1.5% of patients at 24 months. CONCLUSION: The Powerlink system appears safe, and effectively protects patients from AAA rupture over the intermediate term. The graft and stent materials have thus far been free from failure and fatigue. Percutaneous contralateral limb access facilitates graft placement in patients with disadvantaged access routes. Endovascular aneurysm repair with the Powerlink system produces significantly fewer early adverse events compared with open AAA repair, but mortality is equivalent with both procedures. Careful follow-up over the longer term is necessary to ensure the durability of these results.