Randomized EVAR Trials and Advent of Level I Evidence: A Paradigm Shift in Management of Large Abdominal Aortic Aneurysms?

Open Surgery for Abdominal Aortic Aneurysm: 980 Consecutive Patient Outcomes from a High-Volume Centre in the United Kingdom

BACKGROUND

Controversy persists regarding the optimal treatment for large abdominal aortic aneurysm (AAA), highlighted by the publication of the National Institute for Health and Care Excellence (NICE) guideline (NG156) on March 2020. The pendulum of opinion swings once more from endovascular to open surgical treatment. We report our experience over the last 15 years in treating consecutive AAA by open surgery.

METHODS

A retrospective review of a prospectively collected vascular database of all patients undergoing infra-renal open abdominal aortic aneurysm repair (OR) repair from 2004 to 2019 at the largest aneurysm centre in the United Kingdom. OR for elective and emergency (ruptured and symptomatic) outcomes included early morbidity and 30-day mortality, and long-term survival.

RESULTS

1017 patients underwent OR between 2004-2019, on application of our inclusion-criteria 994 patients formed our cohort for analysis (81.2% male) with a mean age 73.6 ± 7.8 years treated by OR for AAA. In that group 672 were elective and 308 were emergency (for ruptured or symptomatic). Overall 30 day mortality was 11.3%, elective 30 day mortality was 2.5%, and emergency 30 day mortality was 29.9%. 30 day re-intervention rate was 9.5%, (elective 7.0%, emergency 15.9%). Survival at 1000 days for elective repair was 72 v 46.7% for emergency and at 2000 days was 43.4% for elective v 25% for emergency.

CONCLUSION

Our data confirm that open surgery for AAA can be performed in large volume centres quite safely. Elective and Emergency surgery does affect early 30 day mortality but does not influence long-term outcome.

Open Surgical Repair of Abdominal Aortic Aneurysms Maintains a Pivotal Role in the Endovascular Era

Since the advent of endovascular aortic repair (EVAR) nearly three decades ago, there has been a paradigm shift in the treatment of the abdominal aortic aneurysm (AAA) to favor EVAR due to its reduced operative mortality, less invasive nature, and faster recovery times. However, more recently there has been an accumulation of data from large meta-analyses and randomized clinical trials revealing that EVAR has no survival benefit after approximately 2 years and is associated with substantially higher rates of reintervention and aneurysm rupture in the long term. These findings call into question the durability of EVAR compared with open aortic repair and emphasize the need for surgeons to remain competent with open aortic surgery in the modern era. This article will provide comprehensive review of a large body of literature comparing endovascular repair to open aortic surgery for the management of AAAs, and it will offer an overview of the open surgical repair technique for AAAs.

The creation of an endovascular exit through the vessel wall using a minimally invasive working channel in order to reach all human organs

Since the establishment of the Seldinger technique for secure entry to the vascular system, there has been a rapid evolution in imaging and catheters that has made the arteries and veins internal routes to any place in the body for interventions. It is curious that a general exit from the vasculature in a similar manner has not been proposed earlier. Possibly, the simplest reason is that accidental perforation of the vasculature by guide wire or catheter is a feared adverse event in endovascular intervention. Most places in the body can be reached by ultrasonography or computed tomography-guided intervention. Some organs such as the central nervous system, the heart and pancreas are harder to access and, in some organs, like the kidney, repeated percutaneous punctions to cover large areas is not suitable. We present a new general purpose micro-endovascular device creating a working channel to these 'hard to reach' organs by an inverted Seldinger technique. This review details this trans-vessel wall technique, which has been studied in pancreas for transplantation of insulin-producing cells, for injection of contrast agent to the heart and to the brain, bowels and kidney in rat, rabbit, swine and macaque monkeys with up to one year of follow-up without adverse events. Furthermore, the payloads that can be given through such a system are briefly discussed. Drugs, cells, gene vectors and other therapeutic substances may be injected directly to the tissue to increase efficacy and decrease risk of off-site adverse effects.

Midterm Results of Endovascular Infrarenal Abdominal Aortic Aneurysm Repair in High-Risk Patients

Short-term and midterm clinical outcomes after endovascular repair of abdominal aortic aneurysms (AAAs) have been well documented. Evaluation of longer term outcomes is now possible. Here we describe our initial 100 high-risk patients treated with endovascular aneurysm repair (EVAR), all with a minimum of 5 years of follow-up. A retrospective review of prospectively recorded data in a departmental database was undertaken for the first 100 consecutive EVAR patients with a minimum of 5 years (range, 60-105 months) of follow-up performed between December 1997 and June 2001. Information was obtained from surgical follow-up visits and family doctors' offices. Endovascular repair of AAA in high-risk patients can be achieved with acceptably low postoperative mortality and morbidity. Longer term results in this high-risk cohort suggest that EVAR is effective in preventing aneurysm-related deaths at 5 years and beyond. All late mortalities were due to patients' comorbid diseases.

Debate: Whether level I evidence comparing thoracic endovascular repair and medical management is necessary for uncomplicated type B aortic dissections

Type B aortic dissections continue to be one of the most challenging clinical scenarios confronting vascular surgeons. In the era of open surgery, the therapeutic options were limited to medical management of hypertension and large open thoracoabdominal operations. In the current endovascular era, the operative strategies have become less invasive but the questions regarding therapeutic approaches have become more numerous and complex. In patients with acute uncomplicated type B aortic dissections, we are still unsure as to which patients are best treated with medical therapy alone or with the addition of early endovascular repair. Data from single centers and registries have provided some guidance; however, questions remain. Perhaps level 1 evidence from well-designed randomized controlled trials will answer all of our questions. This is the topic of the current debate.

Endovascular repair of abdominal aortic aneurysms: only a mechanical solution for a biological problem?

Endovascular aneurysm repair has matured significantly over the last 20 years and is becoming increasingly popular as a minimally invasive treatment option for patients with abdominal aortic aneurysms (AAA). Long-term durability of this fascinating treatment, however, is in doubt as continuing aneurysmal degeneration of the aortoiliac graft attachment zones is clearly associated with late adverse sequelae. In recent years, our growing understanding of the physiopathology of AAA formation has facilitated scrutiny of various potential drug treatment concepts. In this article we review the mechanical and biological challenges associated with endovascular treatment of infrarenal AAAs and discuss potential approaches to ongoing aneurysmal degeneration, which hampers long-term outcomes of this minimally invasive therapy.

Doxycycline therapy for abdominal aneurysm: Improved proteolytic balance through reduced neutrophil content

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) is thought to play a central role in abdominal aortic aneurysm (AAA) initiation. Doxycycline, a tetracycline analogue, has direct MMP-9-inhibiting properties in vitro, and it effectively suppresses AAA development in rodents. Observed inhibition of AAA progression, and contradictory findings in human studies evaluating the effect of doxycycline therapy on aortic wall MMP-9, suggest that the effects of doxycycline extend beyond MMP-9 inhibition and that the effect may be dose-dependent.

METHODS

This clinical trial evaluated the effect of 2 weeks of low- (50 mg/d), medium- (100 mg/d), or high-dose (300 mg/d) doxycycline vs no medication in four groups of 15 patients undergoing elective AAA repair. The effect of doxycycline treatment on MMP and cysteine proteases, and their respective inhibitors, was evaluated by quantitative polymerase chain reaction, Western blot analysis, immunocapture protease activity assays, and immunohistochemistry.

RESULTS

Doxycycline was well tolerated and no participants dropped out. Doxycycline treatment reduced aortic wall MMP-3 and MMP-25 messenger RNA expression (P < .045 and P < .014, respectively), selectively suppressed neutrophil collagenase and gelatinase (MMP-8 and MMP-9) protein levels (P < .013 and <.004, respectively), and increased protein levels of the protease inhibitors tissue inhibitor of metalloproteinase 1 and cystatin C (P < .029). As for the apparent selective effect on neutrophil-associated proteases, we sought for a reducing effect on aortic wall neutrophil content that was indeed confirmed by immunohistochemical analysis that revealed a 75% reduction in aneurysm wall neutrophil content (P < .001).

CONCLUSIONS

Independent of its dose, short-term preoperative doxycycline therapy improves the proteolytic balance in AAA, presumably through an effect on aortic wall neutrophil content. This study provides a rationale for doxycycline treatment in patients with an AAA as well as in other (vascular) conditions involving neutrophil influx such as Kawasaki disease and Behçet disease.

Has the Implementation of EVAR for Ruptured AAA Improved Outcomes?

Objective: Previous studies have demonstrated improved outcomes with Endovascular Aneurysm Repair (EVAR) for the treatment of ruptured abdominal aortic aneurysms (rAAA). However, these data may not be generalizable to all regions.

Methods: Retrospective cohort study (2001-2005) using state inpatient data.

Results: 5,176 patients underwent repair of AAA. 700 repairs were performed for rAAA (618 [88%] with open surgery (OS) and 82 [12%] with EVAR). Mortality for rAAA was similar for EVAR and OS (45.1% vs. 52.4%, P = 0.21). Lack of insurance (OR = 5.1; 95%CI: 1.7-15.2) was a predictor of mortality. Cost of repair for rAAA was greater for EVAR ($51,339 ± 51,719 vs. $39,967 ± 43,354, P = 0.03) and hospital LOS was similar (14.08 ± 17.97 vs.13.42 ± 18.18; P = 0.8). Conclusion: EVAR did not offer a survival benefit in the state, had a similar hospital LOS, and was significantly more expensive. Further evaluation exploring explanations for inferior outcomes by region are required as EVAR becomes more commonly implemented for rAAA.

Longitudinal Outcomes After Endovascular Repair of Abdominal Aortic Aneurysms

Objective: Endovascular abdominal aneurysm repair (EVAR) is increasingly used, but there is insufficient evaluation of long-term outcomes. Method: Retrospective cohort study using the linked Washington State hospital discharge database. Result: 3,350 patients underwent elective repair of AAA (1181 EVAR) between 2000 and 2005. EVAR patients were older and had higher comorbidity scores. The 30-day readmission rate after EVAR was 11.6%. The 30-day readmissions included cardiac complications (18.5%) and device complications (10.4%). 46% of the 30-day readmissions after EVAR underwent procedures: abdominal/ iliac angiography (7.4%), angioplasty (8.9%), and device revision (8.2%). Mean time to late interventions was 611 days. Conclusion: Readmission, reintervention, and complication rates after EVAR occur more commonly than previously described. Cardiac complications were the most common readmission. Almost half of the 30-day readmissions required a secondary intervention. Long-term complications after EVAR occurred before two years. Population-based assessment may be more reflective of “real world” complication rates after EVAR.

AAA Repair: Sociodemographic Disparities in Management and Outcomes

Objective: To evaluate sociodemographic influences on utilization and outcomes of endovascular abdominal aortic repair (EVAR) for the treatment of abdominal aortic aneurysm (AAA).

Methods: Secondary data analysis of the State Inpatient Databases for New Jersey.

Results: Between 2001 and 2006, a total of 6227 adult subjects (mean [SD] age, 73.3 [8.3] years; 77.6% male) underwent AAA repair (3167 EVAR and 3060 open surgery [OS]). Patients receiving EVAR were older than those undergoing OS (mean [SD] age, 74.2 [8.0] vs 72.4 [8.6] years) ( P < .001). Men were 1.60 (95% confidence interval [CI], 1.39-1.77) times more likely to receive EVAR than women. White subjects had the same odds of undergoing EVAR as black subjects, and white subjects had 1.60 (95% CI, 1.29-2.06) times higher odds of receiving EVAR than Hispanics. Subjects with Medicare coverage were 3.90 (96% CI, 2.28-6.59) times more likely to receive EVAR than uninsured subjects. Logistic regression analysis demonstrated that older age, male sex, and Medicare coverage were significantly associated with increased utilization of EVAR and that uninsured subjects and Hispanics are less likely to receive EVAR. Octogenarians and black subjects (odds ratios: 3.69 CI: 2.31-5.91, and 2.59 CI: 1.47-4.54 respectively) had significantly greater likelihood of death after elective AAA repair.

Conclusions: For AAA repair, significant sociodemographic disparities exist in the use of endovascular technology and in mortality. The risk of death after elective AAA repair was significantly greater for black subjects. Further analysis is warranted to delineate inequalities of vascular care for AAA and to assist in formulating policy to address these disparities.

Total laparoscopic repair for abdominal aortic aneurysm

Surgical resection and grafting have long been the standard treatment for abdominal aortic aneurysm and provide an excellent long-term outcome. However, there is tremendous impact on patients due to the surgical invasiveness. Endovascular aortic repair using stent graft was introduced in 1991. After refinement of the techniques and technology, endovascular aortic repair was approved by most health authorities and is associated with less periprocedural morbidities. In between these two extremes, some surgeons endeavored to create an alternative and perform less invasive surgeries. Hand-assisted laparoscopic aortic surgery and laparoscopic-assisted aortic surgery were introduced in 1996. In 2001, total laparoscopic abdominal aortic aneurysm resection with tube graft interposition was first performed in Canada. Till now, only a few vascular units in North America and Europe perform these delicate techniques. We report our first case of total laparoscopic abdominal aortic aneurysm repair. Laparoscopic aortic surgery provides better visualization of the aneurysm neck, less bowel manipulation and avoidance of hypothermia. The minimal invasiveness could translate to better perioperative outcome. To our knowledge, this is also the first case report in Asia. The detailed techniques are described.

A single-institution experience with the AneuRx Stent Graft for endovascular repair of abdominal aortic aneurysm

We report our experience of endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) using the modular AneuRx Stent Graft System. We retrospectively reviewed the outcomes of 113 patients who underwent EVAR with the AneuRx system performed at our institution between October 1999 and August 2003. The mean age of this group was 72.5 years, with 71% (n = 80) over the age of 70 years and 95% (n = 107) males. Aneurysm diameter ranged 4.0-9.0 cm, with 33% (n = 37) >6.0 cm. The average duration of late follow-up was 32.6 +/- 24.8 months (median = 37). Successful deployment of the modular AneuRx system was noted in all patients. There were no immediate operative conversions, deaths within 24 hr of operation, or type I or III endoleaks observed at the completion of the procedure. Thirty-day mortality was 3.5% (n = 4). Acute deployment-related complications occurred in 10% (n = 13) of patients and included misdeployment, operative bleeding, arterial perforation/dissection, and access site complications. Acute systemic complications were present in nine patients, predominantly renal and cardiac complications. An endoleak noted at any time occurred in 25% of patients, with 40% of those requiring a secondary intervention. Two patients suffered late aneurysm rupture due to a type I endoleak and graft infection. Kaplan-Meier analysis revealed 5-year freedom from secondary intervention of 72.4%; freedom from aneurysm-related death of 93.9%; and probability of survival based on all-cause mortality of 60.1%. Endovascular treatment with the modular AneuRx Stent Graft System is safe and effective, producing acceptable rates of disease-free survival and mid-term clinical outcome.

Concomitant colorectal cancer and abdominal aortic aneurysm: evolution of treatment paradigm in the endovascular era

BACKGROUND

Although the incidence of patients presenting with concomitant colorectal cancer (CRC) and abdominal aortic aneurysm (AAA) is low, current treatment strategies in patients with both lesions remains controversial. Given recent advances in endovascular aortic aneurysm repair (EVAR), we sought to analyze the surgical outcomes of patients with concomitant CRC and AAA.

STUDY DESIGN

A retrospective chart review was performed on all patients with CRC and AAA between December 1984 and July 2007.

RESULTS

A total of 108 patients with concomitant CRC and AAA were identified. Forty-six patients presented with symptomatic or obstructing CRC, which was treated with colectomy followed by either open AAA repair (n=35, group A) or EVAR (n=11, group B). Thirty-eight patients underwent either open AAA (n=26, group C) or EVAR (n=12, group D) first, followed by staged CRC resection. Eight patients underwent combined CRC and open AAA repair (group E). The time delays after CRC resection to AAA repair in groups A and B were 42 and 35 days (NS), respectively. The time delays after open AAA or EVAR procedures before CRC resection in groups C and D were 115 days and 12 days (p < 0.0001), respectively. Two patients in group B developed sigmoid ischemia after EVAR and were treated with sigmoid resection. Increased perioperative morbidity and mortality rates were noted in group C (p < 0.002).

CONCLUSIONS

In patients with concomitant colorectal cancer and AAA, the symptomatic lesion should be a treatment priority. Because EVAR results in early recovery and a shorter convalescence compared with open aneurysmorrhaphy, this modality offers potential treatment benefits in patients with suitable anatomy who have concomitant CRC. But EVAR treatment should be offered with caution because of the risk of sigmoid ischemia caused by inferior mesenteric artery occlusion.