Robert J. Hinchliffe

Long-Term Renal Function following Endovascular Aneurysm Repair with Infrarenal and Suprarenal Aortic Stent-Grafts

Purpose: To determine in a retrospective analysis the incidence of renal impairment (RI) following endovascular repair (EVR) of abdominal aortic aneurysm (AAA), to assess the morbidity and mortality in endograft patients with preoperative RI, and to examine the impact of suprarenal stent-grafts on renal function. Methods: From March 1994 to October 2001, 315 AAA patients (289 men; mean age 72.4±7.0 years) undergoing EVR were entered prospectively into a vascular registry. The patients received either an in-house custom-made stent-graft or one of several commercially made devices implanted with infrarenal or suprarenal fixation. Renal function was monitored by serum creatinine measurements prior to discharge and at 3, 6, and 12 months and annually thereafter. Preoperative RI was defined as a serum creatinine > 130 μmol/L and/or long-term dialysis. Postoperative RI referred to a >20% increase in the serum creatinine over baseline. Additional deterioration of renal function in patients with preoperative RI was referred to as postoperatively worsened RI. Results: Of the 315 patients treated, 220 (69.8%) were considered high risk (ruptured AAA or ASA grade III or IV). Sixty-nine (21.9%) patients had preoperative RI (6 [1.9%] on preoperative dialysis). A suprarenal stent-graft was used in 169 (53.7%) patients and infrarenal stent-graft in the remaining 146 (46.3%). The mean follow-up was 30.1 ±22.7 months. Postoperative RI occurred in 53 (16.8%) patients (24 [7.6%] transient, 29 [9.2%] persistent). Patients with preoperative RI had a significantly higher incidence of postoperatively worsened RI (37.7% versus 11.0%, p<0.0001) and a higher mortality related to RI (7.2% versus 1.6%, p=0.02). Suprarenal fixation had no influence on the incidence of RI, on perioperative mortality, or on mortality related to RI. The only significant predictive factor of postoperative RI was preoperative RI (risk ratio 5.09, 95% CI 2.38 to 10.87, p=0.0001). Conclusions: Endovascular AAA repair may lead to persistent postoperative RI in nearly 10% of cases, especially in patients with preoperative RI. Suprarenal stent-graft fixation does not seem to have any deleterious effect on renal function. Further long-term studies are required to confirm the innocuous nature of transrenal stent placement.

Durability of femorofemoral bypass grafting after aortouniiliac endovascular aneurysm repair

INTRODUCTION Endovascular aneurysm repair (EVAR) with aortouniiliac prostheses extends the morphologic range of aneurysms that can be treated and is potentially a more rapid and simple operation than bifurcated endovascular repair. It may, however, be limited by durability of the femorofemoral extra-anatomic bypass graft required to revascularize the contralateral lower limb. Previous studies of femorofemoral bypass grafts were performed almost exclusively in patients with occlusive disease. An 8-year single center experience with use of the femorofemoral bypass graft in aneurysmal disease is reported. METHODS All patients undergoing EVAR with an aortouniiliac endovascular stent graft over eight years (1994-2002) at a single institution were included in a retrospective study. Patient data were collected from a prospectively maintained local endovascular database. All patients gave informed consent and were part of an endovascular program approved by the local ethics committee. RESULTS Over the 8 years, 231 patients underwent EVAR with an aortouniiliac endovascular stent-graft. Median follow-up was 22 months. Localized wound complications were observed in 25 patients (11%). Cumulative 3-year patency rate for the femorofemoral bypass graft was 91%. At the end of 5 years 83% of grafts remained patent. CONCLUSIONS The femorofemoral bypass graft used during EVAR with aortouniliac stent grafts offers encouraging medium and long-term patency. When graft occlusion occurs, it is usually directly attributable to inadequate inflow from the endovascular stent graft itself or to endoluminal damage of the external iliac artery. Awareness and early detection of stent-graft distortion or complications in the external iliac artery may result in improved patency rates.

Anatomical suitability of ruptured abdominal aortic aneurysms for endovascular repair.

Purpose: To assess the anatomical suitability of ruptured abdominal aortic aneurysms (AAA) for emergency endovascular repair. Methods: All cases (46 patients [35 men; mean age 74 years, range 54–85]) in which computed tomographic angiography (CTA) confirmed AAA rupture over a 5-year period at our university hospital were reviewed for anatomical suitability for endovascular repair. Measurements were made by a radiologist experienced in anatomical assessment of CT criteria for elective endovascular aneurysm repair (EVAR). Results: The mean aneurysm neck length was 18 mm (range 0–59); 17 were conical, 13 straight, 4 barrel, and 6 reverse conical. Six cases had no proximal neck. Overall, 37 (80%) patients were unsuitable for EVAR according to our criteria. Nearly half the patients (22, 48%) had ≥2 adverse features. Unsuitable neck morphology (35, 76%) was the primary reason for exclusion, but CIA aneurysm (10, 22%) and EIA tortuosity (7, 15%) were secondary adverse features. Conclusions: With current stent-graft design, the majority of ruptured abdominal aortic aneurysms are anatomically unsuitable for endovascular repair.

The Zenith Aortic Stent-Graft: A 5-Year Single-Center Experience

Purpose: To evaluate the efficacy and midterm results of the Zenith stent-graft in the treatment of abdominal aortic aneurysms (AAA). Methods: Since March 1994, 364 patients have undergone endovascular repair of infrarenal AAA. Of the 94 who were treated with the Zenith stent-graft from 1996 to 2002, 88 patients (82 men; mean age 72.6 ± 6.5 years, range 47–88) with at least 6-month follow-up were analyzed. Sixty-one (69.3%) patients were considered at high risk for intervention; 7 ruptured AAAs were treated emergently. In all, 68 (77.3%) bifurcated stent-grafts (including 18 TriFab systems) and 20 aortomonoiliac configurations were used. Cumulative data on endoleak, migration, secondary procedures, and survival were evaluated with Kaplan-Meier analyses. Results: Implantation success was 97.7%; 2 (2.3%) access-related failures were converted to open repair (1 immediate, 1 at 3 months). There were 3 (3.4%) graft limb thromboses (2 immediate, 1 late), 3 (3.4%) cases of colon ischemia due to embolization in 1 and hypogastric artery occlusion in 2, and 1 (1.1%) renal infarction due to embolism. Three (3.4%) patients died within 30 days. Eleven (12.5%) endoleaks and 1 (1.1%) late endograft migration were recorded. The 5-year cumulative endoleak and migration rates were 15% and 7%, respectively. Sixty-three (71.6%) patients did not present any complication related to the repair during a mean follow-up of 20.6 ± 14.9 months (range 6–68); notably, no complications were associated with the 18 TriFab systems. Six (6.8%) secondary procedures were performed (31% 5-year cumulative secondary procedural rate). All 6 (6.8%) aneurysm-related deaths (the 3 perioperative, 2 from late AAA rupture, and 1 during a secondary procedure) and 14 of 18 (20.4%) non-aneurysm—related deaths occurred in high-risk patients; the 5-year cumulative survival rates were 57% for any death and 92% for aneurysm-related deaths. Conclusions: The Zenith stent-graft appears both safe and effective in terms of midterm outcome of endovascular aortic aneurysm repair.

Comparison of morphologic features of intact and ruptured aneurysms of infrarenal abdominal aorta.

INTRODUCTION Endovascular aneurysm repair (EVAR) has been suggested as a technique to improve outcome of ruptured abdominal aortic aneurysm (AAA). Whether this technique becomes an established treatment will depend, in part, on the anatomy of ruptured AAA. METHODS The anatomy of intact and ruptured AAA seen in a university department of vascular surgery over 5 years was reviewed. Aneurysm anatomy was assessed with spiral computed tomographic angiography. Suitability for EVAR was assessed from the dimensions of the proximal neck and common iliac arteries. Neck length less than 15 mm, neck width greater than 30 mm, and common iliac artery diameter greater than 22 mm were declared unsuitable for EVAR. RESULTS Three hundred sixty-three patients with intact AAA and 46 with ruptured AAA were identified. Larger intact aneurysms were significantly associated with longer renal artery-bifurcation distance and more complex proximal neck architecture. In this sample, patients with ruptured AAA were more likely to have larger aneurysms with shorter and narrower proximal necks. Significantly more intact aneurysms were morphologically suitable for endovascular repair compared with ruptured AAA (78% vs 43%; P <.001). CONCLUSIONS Ruptured AAA are less likely to be suitable for endovascular repair than are intact AAA, most probably because of larger diameter at presentation. Open repair will likely remain the treatment of choice in most patients with ruptured AAA, because of current morphologic constraints of endovascular repair.

Type II endoleak: transperitoneal sacotomy and ligation of side branch endoleaks responsible for aneurysm sac expansion.

Purpose: To demonstrate aneurysm sac expansion in the face of a type II endoleak and its treatment with open ligation of multiple side branch endoleaks. Case Report: An 81-year-old patient had undergone elective endovascular repair of a 6.3-cm infrarenal abdominal aortic aneurysm in September 1999. Routine spiral computed tomographic angiography at 10 months disclosed a type II endoleak; the aneurysm sac diameter had grown to 7.4 cm. Selective angiography revealed multiple lumbar endoleaks and a patent inferior mesenteric artery. Laparotomy and sacotomy was performed, confirming the presence of pulsatile type II endoleaks, which were ligated successfully. The patient made a full postoperative recovery. Conclusions: Type II endoleaks may cause aneurysm expansion. Open repair of multiple type II endoleaks is feasible and may be useful where endovascular or laparoscopic techniques are at high risk of procedural failure, such as multiple endoleak channels.

Endovascular repair of inflammatory abdominal aortic aneurysms.

Purpose: To report a single-center experience with endovascular repair of inflammatory abdominal aortic aneurysm (IAAA), with particular attention to the fate of the aneurysm sac, perianeurysmal fibrosis (PAF), and renal function. Methods: A retrospective review of 350 patients undergoing endovascular aortic aneurysm repair during a 7-year period at University Hospital, Nottingham, identified 14 (4%) cases of IAAA confirmed either on preoperative spiral computed tomography (CT) or at laparotomy in attempted open aneurysm repair. All data were reviewed from a prospectively maintained database, hospital notes, and serial CT studies. Results: Endovascular repair was successfully completed in all 14 IAAA patients, but 2 (14%) died in the perioperative period. One patient referred from another center was lost to imaging follow-up, leaving 11 patients who were followed for a mean 29 months (range 1–73). All 11 IAAAs remained excluded, but 1 patient required a secondary transabdominal intervention for a type III endoleak. There was no CT evidence of PAF progression in any patient. Postoperative renal complications were not encountered where there had been none preoperatively. Conclusions: IAAA may be successfully excluded by the endovascular technique, and EVAR is particularly useful where open repair has failed. The impact of endograft placement on perianeurysmal fibrosis is less clear. In this study, there was no suggestion that the degree of PAF worsens following endovascular repair.

Adjunctive procedures for the treatment of proximal type I endoleak: the role of peri-aortic ligatures and Palmaz stenting.

Purpose: To investigate the feasibility, efficacy, and long-term effects of peri-aortic ligatures and Palmaz stenting used to treat proximal type I endoleak after endovascular repair (EVR) of abdominal aortic aneurysm (AAA). Methods: An 8-year single-center experience with proximal type I endoleak was reviewed; the records of the 55 identified cases were examined to ascertain the methods of treatment used. Among these, all 22 patients who were treated with peri-aortic ligatures and Palmaz stenting were segregated for analysis. Results: The 22 patients (14 men; mean age 74.6 years, range 66–85) with proximal type I endoleak (18 early, 4 late) selected for analysis underwent 23 secondary procedures: 15 involving peri-aortic ligatures and 8 Palmaz stent implantations. Of the 18 early endoleaks, 11 were treated intraoperatively and 7 were observed. Ten (45%) patients died within 30 days of endoleak treatment: 8 had early endoleaks. Five of the 10 deaths occurred in patients successfully treated with peri-aortic ligatures (3/10) or Palmaz stenting (2/7). The 12 (54%) surviving patients suffered no aneurysm-related deaths or secondary endoleaks over a median follow-up of 20 months (range 4–75) Conclusions: Endoleak is an important mode of failure after endovascular repair. Peri-aortic ligatures and Palmaz stenting are feasible techniques for the treatment of proximal endoleak; however, the perioperative mortality of peri-aortic ligatures was higher when compared with other less invasive techniques. In contrast to other therapeutic options, these methods are more effective in the short and medium term.

Ruptured Abdominal Aortic Aneurysm: Endovascular Repair Does Not Confer Any Long-term Survival Advantage Over Open Repair

Recent studies have suggested that endovascular aneurysm repair (EVAR) may reduce the perioperative mortality of ruptured abdominal aortic aneurysm (AAA). Whether EVAR confers any long-term survival advantage over published results for open repair of ruptured AAA has not been established. We conducted a single-center retrospective study over a 10-year period (1994–2004) examining the long-term outcome of patients who have undergone endovascular repair of ruptured AAA. Fifty-four patients underwent endovascular repair of a ruptured AAA. The median age was 75 years (interquartile range 69.5–79.5 years); 42 (78%) patients were male. The perioperative mortality rate was 37%. During a median follow-up of 32 months (range 14–48 months), there were 5 aneurysm-related and 13 non-aneurysm-related deaths. Overall, the 3- and 5-year survival rates were 36% and 26%, respectively. EVAR does not appear to confer any overall survival advantage in the mid- to long term compared with the published results for open repair. The reasons for this remain unclear. Further, larger studies are required to confirm these results.

The Importance of Anatomical Suitability and Fitness for the Outcome of Endovascular Repair of Ruptured Abdominal Aortic Aneurysm

INTRODUCTION Endovascular repair of aortic aneurysm (EVAR) has a lower mortality than open repair. The aim of this study was to assess mortality from EVAR for emergency AAA repair and the impact of fitness for operation and adverse anatomy. METHODS One-hundred and forty two patients who had EVAR for a ruptured AAA (80, REVAR) or a symptomatic AAA (62, SEVAR) between 1994 and 2007 in a single specialist endovascular centre were reviewed. Fitness for surgery was assessed by Hardmans index (age>76, loss of consciousness, Hb<9.0, Cr>190, ischaemic ECG). CT scans were reviewed, compared with operative images and operation notes for adverse anatomy. Details of perioperative complications, and outcome were recorded. RESULTS Overall mortality at 24-h, 30-days and one year were, respectively: 17%, 36%, 50% for REVAR and 5%, 8%, 23% for SEVAR. Overall adverse anatomy increased 30-day mortality. Hardmans index of three or more increased mortality HR=2.59 (1.24-5.41), p=0.01. On Cox regression Univariate analysis increasing Hardmans index score and adverse anatomy increased the overall mortality over time. In multivariate Cox regression analysis (controlled for the Hardmans index) adverse anatomy was associated with significant increase in graft related mortality. CONCLUSION The use of EVAR is feasible in patients who present with a ruptured or acutely symptomatic AAA. Care must be taken not to extend anatomical or clinical guidelines.