Stent-grafting of the thoracic aorta by the cardiothoracic surgeon

A systematic review and meta-analysis of retrograde type A aortic dissection after thoracic endovascular aortic repair in patients with type B aortic dissection

BACKGROUND

Retrograde type A dissection (RTAD) is a devastating complication of thoracic endovascular repair (TEVAR) with low incidence but high mortality. The objective of this study is to report the incidence, mortality, potential risk factors, clinical manifestation and diagnostic modalities, and medical and surgical treatments.

METHODS

A systematic review and single-arm and two-arm meta-analyses evaluated all published reports of RTAD post-TEVAR through January 2021. All study types were included, except study protocols and animal studies, without time restrictions. Outcomes of interest were procedural data (implanted stent-grafts type, and proximal stent-graft oversizing), the incidence of RTAD, associated mortality rate, clinical manifestations, diagnostic workouts and therapeutic management.

RESULTS

RTAD occurred in 285 out of 10,600 patients: an estimated RTAD incidence of 2.3% (95% CI: 1.9-2.8); incidence of early RTAD was approximately 1.8 times higher than late. Wilcoxon signed-rank testing showed that the proportion of RTAD patients with acute type B aortic dissection (TBAD) was significantly higher than those with chronic TBAD (P = .008). Pooled meta-analysis showed that the incidence of RTAD with proximal bare stent TEVAR was 2.1-fold higher than with non-bare stents: risk ratio was 1.55 (95% CI: 0.87-2.75; P = .13). Single arm meta-analysis estimated a mortality rate of 42.2% (95% CI: 32.5-51.8), with an I2 heterogeneity of 70.11% (P < .001).

CONCLUSION

RTAD is rare after TEVAR but with high mortality, especially in the first month post-TEVAR with acute TBAD patients at greater risk as well as those treated with proximal bare stent endografts.

Retrograde Type A Aortic Dissection After Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-Analysis

Background

Retrograde type A aortic dissection (RTAD) is a potentially lethal complication after thoracic endovascular aortic repair (TEVAR). However, data are limited regarding the development of RTAD post‐TEVAR. This systematic review aims to define the incidence, mortality, and potential risk factors of RTAD post‐TEVAR.

Methods and Results

Multiple electronic searches were performed. Fifty publications with a total of 8969 patients were analyzed. Pooled estimates for incidence and mortality of RTAD were 2.5% (95% confidence interval [CI], 2.0–3.1) and 37.1% (95% CI, 23.7–51.6), respectively. Metaregression analysis evidenced that RTAD rate was associated with hypertension (P=0.043), history of vascular surgery (P=0.042), and American Surgical Association (P=0.044). The relative risk of RTAD was 1.81 (95% CI, 1.04–3.14) for acute dissection (relative to chronic dissection) and 5.33 (95% CI, 2.70–10.51) for aortic dissection (relative to a degenerative aneurysm). Incidence of RTAD was significantly different in patients with proximal bare stent and nonbare stent endografts (relative risk [RR]=2.06; 95% CI, 1.22–3.50). RTAD occurrence rate in zone 0 was higher than other landing zones.

Conclusions

The pooled RTAD rate after TEVAR was calculated at 2.5% with a high mortality rate (37.1%). Incidence of RTAD is significantly more frequent in patients treated for dissection than those with an aneurysm (especially for acute dissection), and when the proximal bare stent was used. Rate of RTAD after TEVAR varied significantly according to the proximal Ishimaru landing zone. The more‐experienced centers tend to have lower RTAD incidences.

Secondary Open Aortic Procedure Following Thoracic Endovascular Aortic Repair: Meta-Analytic State of the Art

BACKGROUND

Thoracic endovascular aortic repair is characterized by a substantial need for reintervention. Secondary open aortic procedure becomes necessary when further endoluminal options are exhausted. This synopsis and quantitative analysis of available evidence aims to overcome the limitations of institutional cohort reports on secondary open aortic procedure.

METHODS AND RESULTS

Electronic databases were searched from 1994 to the present date with a prospectively registered protocol. Pooled quantification of pre/intraoperative variables, and proportional meta-analysis with random effect model of early and midterm outcomes were performed. Subgroup analysis was conducted for patients who had early mortality. Fifteen studies were elected for final analysis, encompassing 330 patients. The following values are expressed as "pooled mean, 95% confidence interval." Type B dissection was the most common pathology at index thoracic endovascular aortic repair (51.2%, 44.4-57.9). The most frequent indication for secondary open aortic procedure was endoleak (39.7%, 34.6-45.1). More than half of patients had surgery on the descending aorta (51.2%, 45.8-56.6), and one fourth on the arch (25.2%, 20.8-30.1). Operative mortality was 10.6% (7.4-14.9). Neurological morbidity was substantial between stroke (5.1%, 2.8-9.1) and paraplegia (8.3%, 5.2-13.1). At 2-year follow-up, mortality (20.4%, 11.5-33.5) and aortic adverse event (aortic death 7.7%, 4.3-13.3, tertiary aortic open procedure 7.4%, 4.0-13.2) were not negligible.

CONCLUSIONS

In the secondary open aortic procedure population, type B dissection was both the most common pathology and the one associated with the lowest early mortality, whereas aortic infection and extra-anatomical bypass were associated with the most ominous prognosis.

Biomechanical Changes After Thoracic Endovascular Aortic Repair in Type B Dissection

Thoracic endovascular aortic repair (TEVAR) has evolved into an established treatment option for type B aortic dissection (TBAD) since it was first introduced 2 decades ago. Morbidity and mortality have decreased due to the minimally invasive character of TEVAR, with adequate stabilization of the dissection, restoration of true lumen perfusion, and subsequent positive aortic remodeling. However, several studies have reported severe setbacks of this technique. Indeed, little is known about the biomechanical behavior of implanted thoracic stent-grafts and the impact on the vascular system. This study sought to systematically review the performance and behavior of implanted thoracic stent-grafts and related biomechanical aortic changes in TBAD patients in order to update current knowledge and future perspectives.

Restrictive bare stent for prevention of stent graft-induced distal redissection after thoracic endovascular aortic repair for type B aortic dissection

BACKGROUND

Stent graft-induced distal redissection (SIDR) is one of the major concerns in the durability of endovascular repair for complicated Stanford type B aortic dissection. The characteristics and means of prevention of this complication remain unknown.

METHODS

From April 1997 to March 2010, 674 patients with type B aortic dissections were treated primarily by thoracic endovascular aortic repair (TEVAR) at our center. Criteria for inclusion in this study were treatment primarily with TEVAR and an estimated mismatch rate (ratio of distal diameter of stent graft to long diameter of true lumen) greater than 120%. By this protocol, 465 patients were included in this study and were retrospectively analyzed. Among them, 266 patients were treated in the acute phase, and 199 were treated in the chronic phase.

RESULTS

A total of 311 patients were treated with standard TEVAR and 154 patients with TEVAR + restrictive bare stent (RBS). The preoperative mismatch rate (measured as the preoperative long diameter of the true lumen at the level of the intended distal end of the stent graft) of the SIDR was significantly higher than that of the non-SIDR (192.7 ± 54.9% vs 131.9 ± 10.4%; P ＜ .05). The follow-up mismatch rate of the SIDR was significantly higher than that of the non-SIDR (145.4 ± 34.6 vs 120.3 ± 16.1; P ＜ .05). Compared with the standard TEVAR, TEVAR + RBS was associated with a lower incidence of SIDR (0% vs 2.9%; P = .033) and less secondary intervention (3.9% vs 9.3%; P = .040). Placement of the RBS significantly expanded the true lumen at the level of the descending aorta with the narrowest true lumen and at the level of the distal end of the stent graft.

CONCLUSIONS

The mismatch between the distal diameter of the stent graft and the diameter of the compressed true lumen seems to be the major factor in the occurrence of SIDR. Placement of an RBS, as an adjunctive technique to TEVAR, could reduce the incidence of SIDR. On the basis of early- to midterm observations, RBSs may improve morphological remodeling of the dissected aorta at certain levels.

Thoracic endovascular aortic repair with homemade stent grafts: early and mid-term outcomes

PURPOSE

We reviewed our experience with homemade stent grafts in the repair of a variety of thoracic aortic lesions. The objective of this study was to assess the early and mid-term outcomes of this therapy.

METHODS

From 1999 to 2007, homemade stent grafts were inserted in 88 patients with an atherosclerotic aneurysm, dissection, pseudoaneurysm, trauma, or rupture in the thoracic aorta. The endoprostheses were stainless steel Z-stents covered by a polyester graft, and were custom-designed for each patient.

RESULTS

Placement of stent grafts was technically successful in 81 of the 88 patients (92%). Within 30 days after treatment, 3 patients died, 3 had a cerebral infarction, and 3 had onset of paraplegia or paraparesis. Primary endoleaks were observed in 8 patients (9%). During the mean follow-up period of 32 ± 26 months, 7 patients had persistent endoleaks and 7 had stent-graft migration. The aneurysm-related mortality rate was 7%. The rate of freedom from open-surgery conversion at 32 months was 89.0%.

CONCLUSIONS

Our early experience with elective and emergency thoracic endovascular aortic repair using homemade stent grafts provided therapeutic benefits to high-risk patients. Endoleaks and stent-graft migrations were the factors most commonly responsible for secondary intervention in the mid-term period. Careful follow-up of patients treated with this approach is needed to avoid major complications in the long term.

Emergent thoracic endovascular aortic repair for acute type-B aortic dissection with malperfusion by matsui-kitamura stent graft

Acute type-B aortic dissection with malperfusion is a serious cardiovascular condition associated with high morbidity and mortality. Recent studies have investigated the efficacy of thoracic endovascular aortic repair (TEVAR) as treatment for acute aortic dissection. In this report, we present a case of acute type-B aortic dissection complicated with malperfusion, which was successfully treated with emergent TEVAR for entry closure by a Matsui-Kitamura stent graft (MKSG). MKSG is a flexible custom-made curved stent graft. The main advantages of MKSG for emergent TEVAR include flexibility, shape, and small profile when compressed.

Thoracic Aortic Endograft Explant: A Single-Center Experience

Objectives: We report our experience following thoracic aortic endovascular repair (TEVAR) explant. Methods: A total of 500 TEVARs were performed from 1999 to 2009, with 4 requiring explant. Chart review was performed to identify the indications of explant, operative technique, and perioperative morbidity and mortality. Results: Indications of graft removal included device maldeployment, type I endoleak, aortoenteric fistula, and retrograde type A dissection necessitating aortic root replacement. Reconstruction was achieved with aortic homograft, Dacron, or explant of the proximal component with incorporation of the distal stent into the suture line. Mean follow-up was 13 months (0-50 months). Paraplegia and perioperative death occurred in 1 patient who underwent intraoperative conversion to open repair. There were no other major complications, and graft removal was achieved in all patients. Conclusions: Although rare, familiarity with TEVAR explant is imperative as it is increasingly performed for broader indications. Our limited data suggest that explant can be performed successfully albeit with morbidity.

Occlusion of the left subclavian artery with stent grafts is safer with protective reconstruction

BACKGROUND

Safe fixation of endovascular stent grafts in thoracic aortic disease often requires covering of the left subclavian artery (LSA) with the stent graft. It is controversial whether this occlusion can be done without additional risk of ischemic complications.

METHODS

In 102 patients treated with endovascular stent grafts, the LSA was covered. In a nonrandomized clinical practice, unprotected occlusion of the LSA was performed in 63 patients (61%), whereas 39 patients underwent extrathoracic subclavian to carotid artery revascularization before (n = 28) or concomitantly with (n = 11) the endovascular procedure.

RESULTS

Left cerebral ischemia occurred in 11% of the unprotected group and in 5% of the protected group. The difference was not statistically significant. The difference in spinal cord ischemia was insignificant owing to the low incidence in general, but the covered length of the aorta was significantly longer in the protected group. Arm ischemia after unprotected LSA occlusion occurred in 25%.

CONCLUSIONS

The interpretation of the results remains speculative because many factors contribute to left cerebral ischemia. However, in terms of overall complications, there is a significant difference in favor of the group protected by revascularization of the LSA either before or simultaneously with stent grafting. Arm ischemia is mostly mild and can be managed secondarily. Subclavian revascularization is associated with relatively low risk and should be considered in advance, at least when extended covering of the thoracic aorta is intended.

Endovascular stenting of thoracic aortic aneurysm

In 2005, the findings of the multicenter Gore Tag study led to United States Food and Drug Administration approval for endovascular repair of thoracic aortic aneurysms (TEVAR). TEVAR provides a therapeutic option for patients who have thoracic aortic aneurysm and for the treatment of type B aortic dissection with malperfusion. Spinal cord ischemia and stroke are recognized neurologic complications of TEVAR. Identification of high-risk patients combined with targeted anesthetic and perioperative management may decrease the risk of neurologic complications after TEVAR.

Descending thoracic aortic dissections

Type B dissection has traditionally been managed medically if uncomplicated and surgically if associated with complications. This practice has resulted in most centers reporting significant morbidity and mortality if open repair is required. In the setting of malperfusion, operative repair has been conjoined with fenestration or visceral stenting to improve outcomes. Endovascular stent grafts seem to offer an attractive alternative in the acute complicated type B dissection, with reduced mortality and morbidity, particularly paralysis, compared with open repair. It is reasonable to consider endovascular stent grafts as another tool in managing dissection, but to recognize that open surgical repair still plays an important role, and that the data that define indications and outcomes are still emerging.

How to Build a Cath-Lab Operating Room

Recent developments in cardiac surgery and interventional cardiology have led to the installation of integrated operating rooms that allow both surgical and endovascular procedures. These units offer surgical as well as angiographic equipment and personnel and therefore require special planning and design. A variety of integrated procedures can be performed. Hybrid coronary revascularization, percutaneous valve repair, and aortic stent-graft placement are current developments that are ideally performed in a cath-lab operating room. This review by an international working group of cardiac surgeons and cardiologists outlines the challenges involved with implementation of an integrated operating suite and suggests general planning and construction guidelines.