Viabahn Open Revascularization Technique for Renal Artery Revascularization Reduces Renal Ischemia in Thoracoabdominal Aortic Aneurysm Hybrid Open-Endovascular Repair

Clampless 2 Device: Experimental Study of a Lateral Aorto-Prosthetic Anastomosic Device Without Clamping or Suturing

BACKGROUND

To offer an alternative to conventional techniques of lateral prosthetic anastomosis on arteries which require a long training, and impose an extensive open surgery, we are proposing the clampless 2 device (C2D) implanted by a simple arterial puncture and allows a lateral implantation of a polytetrafluoroethylene (PTFE) vascular graft in an artery, without arterial clamping or suture.

METHODS

C2D is a "T" shaped 25-mm long and 8-mm diameter Nitinol stent with a 6-mm PTFE graft prosthesis mounted laterally on the stent, and implanted in an artery, via a 21-French sheath, and a compliant balloon inflation. In vitro testing of the C2D was first performed on a bench including a segment of a 7-mm internal diameter pig abdominal aorta. A series of 5 consecutive C2D implantation was analyzed with evaluation of the implantation time and the fluid losses at a fluid pressure of 80 and 150 mm Hg. The C2D implantation was finally controlled by angioscopy. An aorto-iliac bypass was then secondly performed on 8 living sows, with a side-to-end C2D implantation in the infrarenal abdominal aorta, followed by a conventional end-to-end prosthetic left iliac trunk anastomosis. The C2D and distal conventional anastomotic times were evaluated, as well as the total operative time and blood loss. A postoperative angiogram was systematically performed.

RESULTS

The C2D was successfully implanted in all 5 in vitro tests, with an average implantation time of 2'58 (range: 2'25-3'22). The mean value of fluid losses was 84 ml (range: 67-94 ml), with no fluid leakage occurring at 80- and 150-mm Hg pressure. All anastomoses were patent after macroscopic study by angioscopy with a perfect application of the stent in the aortic wall. In 8 living sows (mean weight: 42 kg, 37-50 kg), an aorto-left iliac bypass was successfully implanted in all cases, with a total mean procedure time of 101 min (range: 90-130 min), and an average fluid loss of 77 ml (range:20-120 ml). The mean implantation time was 4'39 (range 3'29-5'52) for C2D and 16 min (range 12-17 min) to perform the conventional distal prosthetic-iliac anastomosis. Systematic arteriographic and angioscopy control showed perfect patency of the C2D implantations.

CONCLUSIONS

Preliminary in vitro and acute in vivo testing of C2D implantation show good early results, allowing further long-lasting pig experiments on the way to human homologation.

Long-Term Outcomes of Chronic Type B Aortic Dissection Treated by Thoracic Endovascular Aortic Repair

Background The treatment of chronic type B aortic dissection by thoracic endovascular aortic repair has some challenges, and its long-term outcomes remain unclear. This study aimed to analyze the 5-year clinical outcomes of thoracic endovascular aortic repair of chronic type B aortic dissection, compare the differences between patients with and without adverse aortic events (AAEs), and identify risk factors for AAEs. Methods and Results Patients who underwent thoracic endovascular aortic repair of chronic type B aortic dissection from January 2009 to June 2017 were retrospectively enrolled. The primary end points were AAEs, including aorta-related death, procedural complications, and disease progression requiring reintervention. Clinical outcomes were described at the 5-year follow-up visit. The secondary end point was the comparison of the results between patients with and without AAEs. Univariable and multivariable logistic analyses were used to identify potential risk factors for AAEs. A total of 214 patients were enrolled. AAEs occurred in 46 (21.5%) patients. Compared with patients without AAEs, those with AAEs had higher rates of residual type A aortic dissection (26.1% versus 4.2%, P<0.001) and aortic diameter ≥5.5 cm (69.6% versus 11.3%, P<0.001), and a lower rate of complete false lumen thrombosis (23.9% versus 89.9%, P<0.001). Meanwhile, the median interval from symptom onset to intervention was longer in patients with AAEs (26 months versus 12 months, P=0.004). Partial or no false lumen thrombosis (adjusted odds ratio [AOR], 14.71 [95% CI, 5.67-38.14; P<0.001]) and aortic diameter ≥5.5 cm (AOR, 10.16 [95% CI, 3.86-26.73; P<0.001]) were identified as independent risk factors for AAEs. Conclusions While thoracic endovascular aortic repair of chronic type B aortic dissection might be challenging in some cases, its long-term outcomes appeared promising as this treatment was effective in preventing catastrophic aortic events. Patients with AAEs showed higher rates of residual type A aortic dissection and aortic diameter ≥5.5 cm, a lower rate of complete false lumen thrombosis, and a longer median interval from symptom onset to intervention. Failure of complete false lumen thrombosis and an aortic diameter ≥5.5 cm were predictors of AAEs.

Application of the VORTEC Technique in Creating a Proximal Inflow Conduit in the Circumferentially-Calcified or "Lead-Pipe" Aorta

A heavily calcified or "lead-pipe" aorta can present many challenges to any surgeon. There is higher risk of vessel wall rupture or disruption, distal embolization, and prolonged ischemia time of visceral organs due to longer clamp times. Hybrid revascularization techniques, which were originally described in visceral revascularization during complex aortic procedures, can be potentially utilized for lower extremity bypasses. These techniques, such as "VORTEC," are well-studied and have been shown to have similar patency rates as traditional bypass grafts with the added benefit of decreased ischemia time and lower levels of acute kidney injury and visceral organ ischemia. This allows VORTEC and other similar hybrid techniques to be utilized as options when traditional vessel control cannot be safely achieved during distal revascularization procedures, as we describe in our patient.

Comparison of Clinical Outcomes Following One versus Two Stage Hybrid Repair of Thoraco-Abdominal Aortic Aneurysms: A Comprehensive Meta-Analysis

OBJECTIVE

For thoraco-abdominal aortic aneurysms (TAAA), it is unclear whether it is better to perform hybrid repair in one (single) or two stages (staged). This study aimed to compare the clinical outcomes of single vs. staged hybrid repair of TAAA.

METHODS

The Medline, Embase, and Cochrane Databases (1 January 1994 to 11 May 2020) were searched for studies on hybrid repair of TAAA. Cohort studies and case series reporting outcomes of single and staged hybrid repair of TAAA were eligible for inclusion. The Newcastle-Ottawa scale and an 18 item tool were used to assess the risk of bias. The primary outcome was 30 day mortality, and the secondary outcomes included post-operative complications, overall survival, and other mid term events. A random effects model was used to calculate pooled estimates.

RESULTS

A total of 37 studies was included in the meta-analysis. The quality assessment of the included studies suggested low or moderate risk of bias. The pooled estimates for aneurysm rupture and death during stage interval were 2% (95% CI 0%-4%, I² = 0%) and 4% (95% CI 2%-7%, I² = 0%), respectively. Single repair was associated with a significantly higher 30 day risk of death when compared with patients who completed staged procedures successfully (OR 2.64, 95% CI 1.36-5.12, I² = 0%). Staged repair also had lower incidence of major adverse cardiac events (MACE) (single: 10%, 95% CI 5%-16%; staged: 2%, 95% CI 0%-5%) and intestinal complications (single: 15%, 95% CI 8%-25%; staged: 3%, 95% CI 1%-6%). For mid term outcomes, single and staged repair had comparable 12 month overall survival, aneurysm related mortality, rate of re-intervention, and graft patency.

CONCLUSION

Two stage hybrid repair may represent a better choice for patients with controlled risk of aneurysm rupture, because it can provide lower 30 day mortality risks, MACE, and intestinal complications, as well as comparable mid term outcomes. Randomised controlled trials are needed to ascertain the effect of repair staging in patients for elective TAAA.