Operative Outcomes Using a Side-branched Thoracoabdominal Aortic Graft (STAG) for Thoraco-abdominal Aortic Repair

Association Between Type of Anaesthesia and Clinical Outcome in Patients Undergoing Endovascular Repair of Thoraco-Abdominal Aortic Aneurysms by Fenestrated and Branched Endografts

OBJECTIVE

Although endovascular repair of thoraco-abdominal aortic aneurysm (TAAA) is the treatment of choice in the high risk population that is ineligible for an open surgical approach, little is known about the association between the type of anaesthesia and complications. This study compared the short term clinical outcomes of patients undergoing the visceral step of TAAA with fenestrated endograft aortic repair (FEVAR) and branched endograft aortic repair (BEVAR) under general anaesthesia (GA) with sedation with monitored care anaesthesia (MAC).

METHODS

This single centre, retrospective, observational study recruited 124 consecutive patients undergoing elective F/BEVAR from 2014 - 2021. The primary endpoint was the short term complication rate according to the type of anaesthesia. Secondary endpoints included: need for inotropes or vasopressors for hypotension, time spent in the operating room, and admission to the intensive care unit. Propensity score matching was generated to account for the between group imbalance in the pre-operative covariables.

RESULTS

After propensity score matching, 42 patients under GA were matched with 42 under MAC. The two groups showed no difference in cardiac and non-cardiac complications. Among the secondary outcomes, a higher number of patients in the GA group required inotropes or vasopressors compared with MAC (33% vs. 9%; p = .031). Although GA and MAC showed the same 30 day technical success (81% vs. 83%; p = .078), non-significant lower rates of major adverse events (10% vs. 12%; p = .72), one year re-intervention (14% vs. 21%; p = .39), and one year target vessel instability (10% vs. 21%; p = .39) were observed in the GA group. Overall, the in hospital mortality rate was 4%, with no difference between GA and MAC (2% vs. 5%; p = 1.0).

CONCLUSION

The type of anaesthesia seemed to have no effect on procedure success, peri-operative morbidity, or mortality in patients undergoing F/BEVAR.

Type B aortic dissection residual after proximal aortic repair: an innovative open surgical approach in patients not eligible for endovascular treatment

BACKGROUND

Residual type B aortic dissection (R-TBAD) is a challenging kind of disease affecting an increasing number of patients. Management of R-TBAD has not been specifically addressed in current literature and many of those patients are not eligible for endovascular treatment. Aim of the study was to evaluate the efficacy and feasibility of a specifically conceived procedure the "saguaro branched graft technique" to treat R-TBAD distal to a proximal stent-graft.

METHODS

Data of patients treated between 2015 and 2019 were prospectively collected and retrospectively analysed. Indication for surgery was R-TBAD with chronic malperfusion, aortic enlargement >55mm or rapid growth, and symptomatic aortic enlargement. A dacron graft with four branches has been tailored on the back table by implanting two bifurcated grafts to a tube or bifurcated graft. After left thoracoabdominal incision the proximal endograft has been used as a solid starting point for the distal branched graft. Sequential revascularization of the visceral vessels was performed step by step by suturing each artery outside the aneurysm before opening the distal aorta, while a continued retrograde aortic and visceral perfusion was maintained by a left pump atrio-femoral bypass. After that all visceral branches had been regularly perfused from above, the thoraco-abdominal aorta was open and repaired. Outcome measures were 30-day mortality and 30-day major complications as were long-term all-cause mortality, aorta-related mortality, reintervention and patency rates of the branches.

RESULTS

Thirteen patients with R-TBAD were treated during the study period. Indication for surgery was chronic malperfusion in one patient (7.7%), aortic enlargement >55mm or rapid growth in 9 patients (69.2%), persistent pain with aortic enlargement ≥50mm in 3 patients (23.1%). All patients were considered not eligible for endovascular repair. At 30-days no deaths or re-interventions occurred and major complications including acute cardiovascular events and renal function impairment were not reported; one patient (7.7%) developed postoperative paraplegia. At a mean follow-up period of 19.6±10.2 (range, 8-48) months, reintervention and mortality rates were null. Visceral malperfusion and late-onset renal failure were not reported, and all visceral branches were still patent.

CONCLUSIONS

Despite the potential high risk of open surgery, the "saguaro branched graft technique" appears to be a safe surgical solution for R-TBAD.

Utilizing patient-specific 3D printed guides for graft reconstruction in thoracoabdominal aortic repair

In thoracoabdominal aortic aneurysm repair, repairing the visceral and segmental arteries is challenging. Although there is a pre-hand-sewn and multi-branched graft based on the conventional image-based technique, it has shortcomings in precisely positioning and directing the visceral and segmental arteries. Here, we introduce two new reconstruction techniques using patient-specific 3D-printed graft reconstruction guides: (1) model-based technique that presents the projected aortic graft, visualizing the main aortic body and its major branches and (2) guide-based technique in which the branching vessels in the visualization model are replaced by marking points identifiable by tactile sense. We demonstrate the effectiveness by evaluating conventional and new techniques based on accuracy, marking time requirement, reproducibility, and results of survey to surgeons on the perceived efficiency and efficacy. The graft reconstruction guides cover the segmentation, design, fabrication, post-processing, and clinical application of open surgical repair of thoracoabdominal aneurysm, and proved to be efficient for accurately reconstructing customized grafts.

Pre-sewn Multi-branched Aortic Graft and 3D-Printing Guidance for Crawford Extent II or III Thoracoabdominal Aortic Aneurysm Repair

Reconstruction of the visceral and segmental arteries is a challenging part of open surgical repair of extensive thoracoabdominal aortic aneurysm (TAAA). For more efficient reconstruction of these branching vessels, a technique of using pre-hand-sewn multi-branched aortic graft (octopod technique) has been adopted with the aid of 3D-printing-guidance in latest cases. The octopod graft has been employed for the extent II or III TAAA repair, in which the commercially available two 4-branched aortic grafts were interconnected before surgery. Since January 2017, 3D-printed-aortic model has been used to efficiently replicate the projected aorta shape fitted to patient's anatomy. From May 2015 through Oct 2019, 20 patients (median age, 40years; range, 23-65; 5 females) underwent extent II or III TAAA repair using the octopod technique with (n = 9) or without (n=11) 3D-printing-guidance. Thirteen patients (65%) were diagnosed as Marfan syndrome. Eighteen patients (90%) had undergone prior aorta repair including 4 patients (20%) undergoing redo-thoracotomy. Revascularization of segmental arteries was conducted in 19 patients (95%, median, N = 2; range, 1-4). Median pump and entire procedural times were 173.5 minutes (interquartile range [IQR], 136.8-187.8) and 441 minutes (IQR, 392.8-492.3), respectively. There was no operative mortality or stroke, however, permanent paraplegia occurred in one patient (5%). During follow-up (median 35months, range 1-56 months), all of reconstructed branched vessels remained wide patent on CT. The octopod technique for open TAAA repair showed favorable early and mid-term results with high feasibility of procedural efficiency. 3D-printing guidance is expected to improve the flow of surgical procedures especially in challenging anatomy.

[Aneurysms of the thoracic and thoracoabdominal aorta]

The incidence and operations of thoracic and thoracoabdominal aortic aneurysms have significantly increased. The indications for repair are considered to be a diameter of 6 cm or more and 5.5 cm for patient groups with increased risk of rupture. Complex open surgical repair is associated with significant mortality and complication rates. Total or hybrid endovascular repair seems to reduce early postoperative complications and mortality. The endovascular approach has evolved to be a good and predominant alternative to open repair of these aneurysms for older and high-risk patients as well as for aneurysms with optimal morphological suitability. Notwithstanding, at present a complete paradigm shift from open to endovascular repair for all patients, especially those with complex aneurysms, cannot yet be established.

Evaluation of the optimal visceral branch configuration in open thoracoabdominal aortic repair by computed tomography

BACKGROUND

In thoracoabdominal aneurysm (TAAA) repair, our technical modification of visceral reconstruction using longer cut pre-sewn side branches has provided good surgical outcomes. Here, we assessed the long-term durability and patency of revascularized branches using computed tomography (CT) to confirm the validity of our approach.

METHODS

Early and late CT evaluations were performed in 11 TAAA patients (males: 5; mean age: 60.6 years) using the Coselli graft to evaluate the position of main graft and the diverging pattern and patency of side branches. Seven of 11 were sutured in an extra-anatomical fashion using longer cut side branches.

RESULTS

In Anatomical (n = 4) and Extra-anatomical (n = 7) groups, the early patency of side branches was not significantly different. Although the late patency of right renal artery (RA) was 100% in both groups, the one of left RA was 60% in Extra-anatomical, while 100% in Anatomical. Furthermore, the main graft in Extra-anatomical was significantly posterior and leftward to the spine with left RA side branch diverging at an acute angle.

CONCLUSIONS

When a pre-sewn branched graft designed for TAAA is used, the graft should be sutured in a fashion similar to normal patient anatomy to minimize the possibility of kinking of RA side branch for the patency.

Open reconstruction of thoracoabdominal aortic aneurysms

Technical details of our strategy for reconstructing the thoracoabdominal aorta are presented. Between October 1999 and June 2012, 152 patients underwent surgery for thoracoabdominal aortic aneurysms (Crawford classification type I =21, type II =43, type III =73, type IV =15). Mean age was 64.6±13.9 years. Sixty-three (41.4%) patients had aortic dissection, including acute type B dissection in 2 (1.2%) and ruptured aneurysms in 17 (11.2%). Eight (5.3%) patients had mycotic aneurysms, and 3 (2.0%) had aortitis. Emergent or urgent surgery was performed in 25 (16.4%) patients. Preoperative computed tomography (CT) scan or magnetic resonance (MR) angiography detected the Adamkiewicz artery in 103 (67.8%) patients. Cerebrospinal fluid drainage (CSFD) was performed in 115 (75.7%) patients and intraoperative motor evoked potentials were recorded in 97 (63.8%). One hundred and seven (70.4%) patients had reconstruction of the intercostal arteries from T7 to L2, 35 of which were reconstructed with the aortic patch technique and 72 with branched grafts. The mean number of reconstructed intercostal arteries was 3.1±2.5 pairs. Mild hypothermic partial cardiopulmonary bypass at 32-34 °C was used in 105 (69.1%) patients, left heart bypass was used in 4 (2.6%), and deep hypothermic cardiopulmonary bypass below 20 °C was used in 42 (27.6%). Thirty-day mortality was 9 (5.9%), and hospital mortality was 20 (13.2%). Independent risk factors for hospital mortality were emergency surgery (OR 13.4, P=0.003) and aortic cross clamping over 2 hours (OR 5.7, P=0.04). Postoperative spinal cord ischemia occurred in 16 (10.5%, 8 patients with paraplegia and 8 with paraparesis). Risk factors for developing spinal cord ischemic complications were prior surgery involving either the descending thoracic or the abdominal aorta (OR 3.75, P=0.05), diabetes mellitus (OR 5.49, P=0.03), and post-bypass hypotension <80 mmHg (OR 1.06, P=0.03). Postoperative survival at 5 years was 83.6±4.5%; 5-year survival was 47.5±8.6% in patients with spinal cord ischemia and 88.9±10.4% in those without spinal cord ischemia.

Modified technique for reconstructing the visceral arteries in thoracoabdominal aortic repair

We present a modified technique for reconstructing the visceral arteries in thoracoabdominal aortic repair. After the proximal and distal anastomosis of a main tubular graft with four pre-sewn side branches, each visceral artery is cannulated and perfused with 25 °C blood (sum total, 800 mL/min). Then, each side branch is placed around the main graft, forming a gently curved loop around it. Finally, the orifice of each visceral artery is sutured to a side branch. This technique prevents kinking of the side branches and enables hemostasis to be secured with a clear view of all the suture lines.