Thoracic endovascular aortic repair for chronic DeBakey IIIb aortic dissection

Expert Panel on Vascular Imaging and Interventional Radiology, Ripley B, Scheidt MJ, Aghayev A, Kim CY, Hedgire SS, Ahmed O, Ahmad S, Clough RE, DeMartino RR, Ferencik M, Hughes GC, Klitzke AK, Steenburg SD, Thomas R, Wells BJ, Wolf SJ, Pinchot JW, Majdalany BS. ACR Appropriateness Criteria® Thoracic Aortic Aneurysm or Dissection-Treatment Planning and Follow-Up: 2024 Update

Diseases of the thoracic aorta include two broad categories: aneurysmal dilation involving all three layers of the intact aortic wall, and acute aortic syndromes, wherein at least one layer of the aortic wall is disrupted, such as in aortic dissection. These diseases carry a variable risk of subsequent aortic rupture, which is associated with high morbidity and mortality. Imaging is critical in the diagnosis, surveillance, and treatment of this constellation of diseases. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Transcatheter electrosurgical aortic septostomy optimizes distal landing zone in chronic dissection

Objective

Efficacy of thoracic endovascular aortic repair (TEVAR) for chronic type B aortic dissection (CTBAD) is dependent on eliminating retrograde false lumen perfusion and remodeling the aorta. We describe the efficacy of a novel transcatheter electrosurgical technique to fenestrate the dissection flap and create a distal seal zone for TEVAR in CTBAD.

Methods

A retrospective review of the Emory Aortic Database from 2016 to 2023 identified 33 patients who underwent TEVAR with intentional endovascular rupture of the dissection flap (Knickerbocker; KNICK) for CTBAD. In 11 patients, we performed transcatheter electrosurgical aortic septostomy (TECSAS) before KNICK. The technical aspects of TECSAS + KNICK are described and results compared with TEVAR + KNICK alone.

Results

Dissection chronicity, aortic size, and preoperative demographics were similar between groups. Technical success was 100%, with zero stroke or paraplegia in both groups. Thirty-day mortality for TECSAS versus KNICK was 0% versus 13.6% (P = .199). Median follow-up was shorter after TECSAS versus KNICK, although not statistically significant (14.6 months vs 21.9 months; P = .065). Elimination of retrograde false lumen perfusion (TECSAS 100% vs KNICK 68.2%; P = .035) and complete false lumen thrombosis or obliteration (TECSAS 91.9% vs KNICK 54.6%; P = .037) were more frequent after the TECSAS procedure. Aortic reinterventions were less frequent after TECSAS versus KNICK (0% vs 13.6%, P = .199), although not statistically significant.

Conclusions

The addition of TECSAS to intentional endovascular rupture of the dissection flap in CTBAD improves distal seal, eliminating retrograde false lumen perfusion. This technique is a safe and precise method to fenestrate a dissection flap and optimize TEVAR in CTBAD.

Aortic Remodeling After Thoracic Endovascular Aortic Repair for Nonacute Uncomplicated Type B Aortic Dissection

BACKGROUND

Entry closure with thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection (TBAD) results in aortic remodeling recently. This study aimed to evaluate the relationship between aortic diameter or timing of surgical intervention from onset and remodeling after TEVAR for uncomplicated nonacute TBAD.

METHODS

Between April 2014 and December 2021, 83 consecutive patients underwent TEVAR for TBAD at our center. Forty patients with subacute and chronic uncomplicated TBADs with a patent false lumen, who could be followed up for at least 6 months, were included in this study. Indications for TEVAR included aortic diameter enlargement and preemptive treatment to prevent future aneurysmal changes in patients at risk of aortic diameter enlargement. Aortic remodeling was accessed, and data between the remodeling and nonremodeling groups were compared.

RESULTS

The technical success rate was 97.5%, with a type Ia endoleak remaining in 1 patient. No operative or in-hospital mortality occurred. Paraparesis occurred in only 1 patient (2.5%). Follow-up was completed at a median of 53.5 months. Late death occurred in 3 cases, but there were no aortic-related deaths. Late aortic remodeling was achieved in 22 patients (55%). The preoperative maximum aortic diameter (PMAD) in the thoracic aortic region was 51.5 mm in the nonremodeling group, significantly larger than 42.5 mm in the remodeling group (P < 0.0001). The cutoff value of the PMAD for predicting aortic remodeling was 45 mm (area under the curve, 0.917; P = 0.028). The remodeling group had an earlier time from onset to intervention than the nonremodeling group, with a cutoff value of 6.3 months (area under the curve, 0.743; P = 0.021).

CONCLUSIONS

TEVAR for nonacute uncomplicated TBAD resulted in a late aortic remodeling rate of 55%. This study suggested that a PMAD of >45 mm or a period >6.3 months between dissection onset and surgery hinders aortic remodeling after TEVAR.

Fate and Consequences of the False Lumen after TEVAR in Type B Aortic Dissection

BACKGROUND

Type B aortic dissection (TBAD) occurs due to an entry tear in the intimal layer of the aorta distal to the origin of the left subclavian artery where blood enters the newly formed false lumen (FL) and extends distally or proximally to form a dissection over an indeterminate length of the aorta which, over time, may eventually rupture. Thoracic endovascular aortic repair (TEVAR) aims to seal off the entry tear proximally with the stent-graft, occluding the origin of the dissection and excluding the FL. Nevertheless, in some cases, the perfusion to the FL is maintained, hindering the aortic remodelling process and increasing the risk of aneurysmal degeneration and rupture, particularly in the abdominal aorta where evidence suggest that remodelling is slower. This review examines the long-term effects of a patent or partially thrombosed FL on clinical outcomes following TEVAR in TBAD, also highlighting the pathological processes behind negative aortic remodelling. Another aim of this review is to provide an overview and appraisal of the currently available techniques for managing a patent or partially thrombosed FL to prevent long-term morbidity occurring.

METHODS

A comprehensive literature search was performed using several search engines including PubMed, Ovid, Google Scholar, Scopus, and Embase to identify and extract relevant studies.

RESULTS

Evidence in the literature show that a partially thrombosed FL is more dangerous than a patent FL due to the occlusion of the distal re-entry tears, impeding outflow and increasing mean arterial and diastolic pressures, whereas the latter is decompressed via distal re-entry sites. FL thrombosis and satisfactory remodelling is sometimes achieved in as few as 40% of patients after TEVAR due to the maintained perfusion of the FL either at the level of the thoracic or abdominal aorta. However, although the thoracic aorta is predominantly covered by the TEVAR stent-graft, poorer remodelling and more dilation is seen in the abdominal aorta. Several techniques are available to embolize the FL, including the Provisional Extension to Induce Complete Attachment, Stent Assisted Balloon Induced Intimal Disruption and Relamination in Aortic Dissection Repair, candy-plug, and Knickerbocker techniques.

CONCLUSIONS

The management of TBAD is invariably TEVAR to seal off the proximal entry tear while extending the repair distally to completely exclude the FL. A risk of aortic wall dilatation distal to TEVAR stent-graft remains; hence, regular monitoring and accurate imaging are essential. At present, a patent FL can be treated using a range of different endovascular techniques.

Methods and outcomes of endovascular false lumen embolization for thoracic aortic dissection

PURPOSE

To provide a contemporary review on endovascular false lumen (FL) embolization for thoracic aortic dissection (AD) and evaluate its early outcome.

METHODS

A systematic literature review on FL embolization for thoracic AD from January 2003 to December 2020 was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. Each article was analyzed using a standardized protocol including predefined demographic characteristics, perioperative mortality and major complications.

RESULTS

A total of 29 papers with 229 patients were included into the analysis. The methods of FL occlusion used were: the Candy-Plug technique, the knickerbocker technique, the "cork in the bottleneck" technique and direct FL embolization with combination of stent-grafts, coils, onyx, plugs and glue. FL embolization procedure was performed in 79 patients (34.5%) with type A AD and 150 (65.5%) with type B AD. FL direct embolization was the most frequently used technique, and it was applied in 198 (86.5%) patients. Candy-plug, knickerbocker and "cork in the bottleneck" techniques were used in 26 (11.4%), 3 (1.3%) and 2 (0.9%) patients, respectively. Technical success was achieved in all patients except one (228/229, 99.6%) in which implantation of a stent to celiac trunk was not possible. There were four hospital deaths (1.7%). Neurological complications occurred in 6 patients (2.6%), including 4 (1.7%) spinal cord ischemia and 2 (0.9%) ischemic stroke. There were 1 (0.4%) iatrogenic retrograde dissection and 2 (0.9%) renal failure reported. The mean duration of follow-up was 16.5 months. There were 21 deaths (9.3%) during follow-up, and 8 (3.6%) were aorta-related. Thirty-three (14.7%) secondary intervention were performed. Five patients (2.2%) required open completion thoracoabdominal procedure incorporating the stent-graft into the repair. Complete FL thrombosis was observed in 181 (80.4%) patients, 34 (15.1%) had partial thrombosis, and 10 (4.4%) had FL progression.

CONCLUSIONS

FL embolization of the distal thoracic aorta is a promising technique in a group of patients to promote FL thrombosis and aortic remodeling in thoracic aorta.

Aortic remodeling after false lumen occlusion using an atrial septal occluder in chronic DeBakey IIIb aortic dissection

OBJECTIVE

Retrograde false lumen flow through distal entry tears poses a challenge in the treatment of chronic DeBakey IIIb aneurysms. In the present report, we have described the feasibility and outcomes of false lumen occlusion using an atrial septal occluder (ASO) in chronic DeBakey IIIb dissection associated with a descending aneurysm.

METHODS

All the patients who had undergone thoracic endovascular aortic repair for chronic DeBakey IIIb aortic dissection at our institution from January 2014 to November 2020 were retrospectively reviewed. The primary endpoints were technical success and in-hospital postoperative results. The secondary endpoints included the midterm survival status and aortic remodeling outcomes.

RESULTS

A total of 37 patients (age, 56.24 ± 10.47 years) with persistent retrograde false lumen perfusion and aneurysm formation at the thoracic segment were treated using an ASO for false lumen occlusion. We achieved 100% technical success. No spinal cord ischemia or in-hospital death was observed. The median follow-up time was 36 months (interquartile range, 24-51 months). After the procedure, three patients (8.1%) had had an endoleak (type Ia in two patients and type II in one patients), and five patients had required late reintervention. The overall 5-year survival rate was 71%. One aortic-related death (2.7% of the total cohort) occurred during follow-up at 9 months. Complete thrombosis of the false lumen along the treated aortic segment was recorded postoperatively in 34 patients (91.9%) at the final follow-up using computed tomography angiography. In a mixed-effects model, a diameter analysis revealed that the thoracic true lumen diameter had increased and the thoracic false lumen diameter had decreased significantly (0.256 mm/mo, P < .001; and -0.512 mm/mo, P < .001, respectively).

CONCLUSIONS

The combination of standard thoracic endovascular aortic repair and false lumen occlusion using the ASO to promote false lumen thrombosis and remodeling in the treated segments is a technically feasible and effective alternative treatment of chronic DeBakey IIIb dissection with an associated descending aneurysm. This approach yielded satisfactory midterm survival outcomes and a low incidence of aortic-related death in our patients. However, further studies with more subjects and a prospective design should verify our findings before routine clinical implementation of this technique.

Unique characteristics of the type B aortic dissection patients with malperfusion in the Vascular Quality Initiative

OBJECTIVE

Type B aortic dissection (TBAD) complicated by malperfusion carries high morbidity and mortality. The present study was undertaken to compare the characteristics of malperfusion and uncomplicated cohorts and to evaluate the long-term differences in survival using a granular, national registry.

METHODS

Patients with TBAD entered into the thoracic endovascular aortic repair/complex endovascular aortic repair module of the Vascular Quality Initiative from 2010 to 2019 were included. The demographic, radiographic, operative, postoperative, in-hospital, and long-term reintervention data were compared between the malperfusion and uncomplicated TBAD groups using t tests and χ² analysis, as appropriate. Overall survival was compared using Cox regression to generate survival curves.

RESULTS

Of the 2820 included patients, 2267 had uncomplicated TBAD and 553 had malperfusion. The patients with malperfusion were younger (age, 55.8 vs 61.2 years; P < .001), were more often male (79.7% vs 68.1%; P < .001), had a higher preoperative creatinine (1.8 vs 1.1 mg/dL; P < .001), had more often presented with an American Society of Anesthesiologists class of 4 or 5 (81.9% vs 58.4%; P < .001), and had more often presented with urgent status (77.4% vs 32.8%; P < .001). In contrast, the uncomplicated TBAD group had had more medical comorbidities, including coronary artery disease and chronic obstructive pulmonary disease, and a larger aortic diameter (4.0 cm vs 4.9 cm; P < .001). The malperfusion group more frequently had proximal zones of disease in zones 0 to 2 (38.6% vs 31.5%; P = .002) and distal zones of disease in zones 9 and above (78.7% vs 46.2%; P < .001), with a greater number of aortic zones traversed (7.7 vs 5.1; P < .001) and a greater frequency of dissection extension into branch vessels (61.8% vs 23.1%; P < .001). Patients with malperfusion also exhibited greater case complexity, with a greater need for branch vessel stenting and longer procedure times. The overall incidence of postoperative complications was greater in the malperfusion group (39.4% vs 17.1%; P < .001) and included a greater rate of spinal cord ischemia (6.3% vs 2.2%; P < .001), acute kidney injury (10.4% vs 0.9%; P < .001), and in-hospital mortality (11.6% vs 5.6%; P < .001). In-hospital reintervention was also greater for the malperfusion patients (14.5% vs 7.4%; P < .001), although the incidence of long-term reinterventions was similar between the two groups (8.7% vs 9.7%; P = .548). A proximal zone of disease in zone 0 to 2 was associated with decreased survival. In contrast, a distal zone of disease in 9 and above, in-hospital reintervention, and long-term follow-up were associated with increased survival. Despite these differences, long-term survival did not differ between the malperfusion and uncomplicated groups (P = .320.) CONCLUSIONS: Patients presenting with TBAD and malperfusion represent a unique cohort. Despite the greater need for branch vessel stenting and in-hospital reintervention, they had similar long-term reintervention rates and survival compared with those with uncomplicated TBAD. These data lend insight with regard to the observed differences between uncomplicated and malperfusion TBAD.

Late Aortic Expansion After Thoracic Endovascular Aortic Repair for Chronic DeBakey IIIb Dissection

BACKGROUND

The efficacy of thoracic endovascular aortic repair (TEVAR) for chronic DeBakey IIIb aortic dissection is still under discussion. This study was performed to investigate the incidence of and risk factors for late aortic expansion after TEVAR for chronic DeBakey IIIb aortic dissection.

METHODS

From March 2014 to April 2019, a total of 35 patients with chronic DeBakey IIIb aortic dissection underwent TEVAR in our institution. Risk factors for aortic expansion events were examined by stepwise Cox regression analysis. Aortic expansion events were defined as reintervention for expansion or aortic expansion of greater than 5 mm.

RESULTS

No operative death occurred, and the 2-year survival rate was 96.8%. The 1- and 2-year rates of freedom from reintervention were 87.8% and 80.2%, respectively. During follow-up, 11 patients had late aortic expansion events (4 with expansion of the thoracic aorta and 7 with expansion of the abdominal aorta). The 1- and 2-year rates of freedom from aortic expansion were 87.8% and 68.7%, respectively. Significant risk factors for expansion events were aortic dilation at the celiac level (hazard ratio [HR], 1.11; P = .015), saccular aneurysm formation of the false lumen (HR, 5.08; P = .049), and high number of residual large reentries (>5 mm) (HR, 2.78; P = .027).

CONCLUSIONS

In patients undergoing TEVAR for chronic DeBakey IIIb aortic dissection, late aortic expansion in both the thoracic and abdominal aorta remains an important issue. Aggressive additional intervention should be considered for high-risk patients with residual large reentries and aortic dilation at the celiac level.

Preoperative distal aortic diameter is a significant predictor of late aorta-related events after endovascular repair for chronic type B aortic dissection

OBJECTIVES

Long-term therapeutic effects of thoracic endovascular aortic repair (TEVAR) for chronic type B aortic dissection remain controversial. This study aimed to evaluate the possible predictors of late aortic rupture and re-interventions after TEVAR.

METHODS

We retrospectively reviewed the operative outcomes of 40 patients who underwent TEVAR for chronic type B aortic dissection at Kyushu University Hospital. During a mean follow-up period of 39.2 months, we assessed aortic morphology via computed tomography and then employed a multivariable Cox regression analysis in an attempt to identify the predictors of late aorta-related events.

RESULTS

The early success rate of TEVAR was 100%. During the follow-up, however, three patients died from aortic rupture. Eight patients required aortic re-intervention, including thoraco-abdominal aortic graft replacement, repeated TEVAR, total arch replacement and EVAR. Multivariable Cox regression analysis revealed that the preoperative maximum distal aortic diameter was a significant predictor of late aorta-related events. The cutoff value of the distal aortic diameter was 40 mm. Freedom from aorta-related events was 94.6% at 1 year and 78.3% at 3 years. The survival rate was not significantly different despite the re-intervention.

CONCLUSIONS

TEVAR is an effective treatment for chronic type B dissection, with acceptable mid-term results. The preoperative distal aortic diameter is a significant risk factor for late aorta-related events. When the maximum distal aortic diameter is ≥ 40 mm, a therapeutic strategy should be developed taking into consideration the possible need for aortic re-intervention.

Outcomes and risk factors of postoperative hepatic dysfunction in patients undergoing acute type A aortic dissection surgery

Background

Postoperative hepatic dysfunction (HD) increases the morbidity and mortality risk after cardiac surgery; however, only a few studies have specifically focused on acute type A aortic dissection (AAAD) surgery. We explored the possible risk factors and outcomes of early postoperative HD in patients with AAAD undergoing surgery.

Methods

All patients who underwent AAAD surgery at our institution from April 2015 to April 2017 were retrospectively evaluated. Postoperative model for end-stage liver disease (MELD) score was used to define HD. Independent risk factors for HD were determined by multivariate logistic analysis.

Results

Two hundred fifteen patients with AAAD met the inclusion criteria. The incidence rate of early postoperative HD was 60.9%, and the rate of in-hospital mortality was 16.8%. Patients with a high postoperative MELD score had longer mechanical ventilation time, longer durations of intensive care unit (ICU) stay, and higher in-hospital mortality. During the postoperative period, patients with AAAD complicated by HD needed continuous renal replacement therapy (CRRT), reintubation, tracheostomy, and blood transfusion more frequently. Aortic cross clamp (ACC) time [per 10 min higher; odds ratio (OR): 1.216, 95% confidence interval (CI): 1.017-1.454, P=0.032], postoperative leucocytes (per 2×10⁹/L higher; OR: 1.161, 95% CI: 1.018-1.324, P=0.026), postoperative respiratory dysfunction (OR: 3.176, 95% CI: 1.293-7.803, P=0.012), and postoperative low cardiac output syndrome (LCOS) (OR: 12.663, 95% CI: 1.432-111.998, P=0.022) were independent risk factors associated with HD in patients undergoing AAAD surgery.

Conclusions

Postoperative HD prolongs mechanical ventilation time and ICU stay, and is associated with increased in-hospital mortality among patients who undergo AAAD surgery. Several factors are associated with a high postoperative MELD score.

Impact of Renal Artery Stent-Graft Placement on Renal Function in Chronic Aortic Dissection

PURPOSE

To evaluate the effect of renal stent-graft placement on kidney function and size alternation in chronic aortic dissection.

MATERIALS AND METHODS

Twenty-five consecutive patients with chronic aortic dissection after thoracic endovascular aortic repair who underwent renal stent-graft placement between January 2015 and December 2016 were retrospectively reviewed. Forty-three patients with chronic aortic dissection who received thoracic endovascular aortic repair in the same period were reviewed as a control group for kidney volume comparison.

RESULTS

Twenty-five stent-grafts were deployed over 25 renal arteries. Overall renal function was assessed by the slope of the regression line constructed from the plots of creatinine clearance versus time within 2 years after the procedure (-0.2810 vs -0.3146 mL/min^-1/mo^-1, P = .868), kidney volume at 12 months (129.4 ± 40.9 vs 137.0 ± 44.2 cm², P = .193) and effective renal plasma flow at 6 months (106.3 ± 46.9 vs 124.4 ± 55.5 mL/min, P = .050) and was not significantly deteriorated. Seven treated patients (87.5%) with a renal artery supplied by a false lumen had a decrease in kidney volume, as did 14 patients (56%) in the control group (P = .206). Three patients with a dissected renal artery (75%) in the stent-graft group had an increase in kidney volume compared with 1 patient (11.1%) in the control group (P = .052).

CONCLUSIONS

Occlusion of the re-entry tear by a stent-graft in the renal artery remains a safe strategy to promote false lumen thrombosis. The stent-graft poses a potential risk of reducing the kidney volume in kidneys supplied by the false lumen but may provide a positive effect in kidney volume with a concomitant dissected renal artery in chronic aortic dissection.

Outcomes of Stentless Thoracic Endovascular Aortic Repair for Chronic DeBakey IIIb Aneurysms

BACKGROUND

We introduce a new endovascular procedure for favorable aortic remodeling in patients with chronic DeBakey IIIb (CDIIIb) aneurysms and present outcomes.

METHODS

This study included 19 patients who underwent stentless thoracic endovascular aortic repair (TEVAR) for CDIIIb aneurysms between 2014 and 2016. Stentless TEVAR is defined as an endovascular procedure involving closure of communicating channels or obliteration of the false lumen itself using various materials. Thoracic false lumen thrombosis was defined as there was no flow in the false lumen of the thoracic aorta. Aortic diameter was measured at 3 levels (left subclavian artery, pulmonary artery bifurcation, and celiac axis).

RESULTS

Fifteen of 19 (78.9%) patients demonstrated thoracic false lumen thrombosis. There was no mortality, and the mean follow-up duration was 16.8 months. False and true lumen diameters at the left subclavian and pulmonary artery levels significantly changed after the procedure (false lumen: 22.6 ± 16.6 versus 16.1 ± 14.4 mm, 23.2 ± 14.6 versus 18.0 ± 13.2 mm, p = 0.001 and p = 0.002, respectively; true lumen: 22.7 ± 8.7 versus 27.9 ± 6.3 mm, 19.0 ± 8.3 versus 24.3 ± 6.7 mm, p = 0.001 and p = 0.001, respectively). The number of visceral stent grafts and preoperative true lumen diameter at the pulmonary artery were independent predictors for thoracic false lumen thrombosis (hazard ratio, 3.445, 95% confidence interval, 1.494 to 7.946; p = 0.004; and hazard ratio, 1.106; 95% confidence interval, 1.029 to 1.189; p = 0.006, respectively).

CONCLUSIONS

Stentless TEVAR seems to be a safe procedure and enables favorable aortic remodeling. Thus, this technique can be useful in a selected group of patients with CDIIIb aneurysms.

Flow pattern analysis in type B aortic dissection patients after stent-grafting repair: Comparison between complete and incomplete false lumen thrombosis

Endovascular stent graft repair has become a common treatment for complicated Stanford type B aortic dissection to restore true lumen flow and induce false lumen thrombosis. Using computational fluid dynamics, this study reports the differences in flow patterns and wall shear stress distribution in complicated Stanford type B aortic dissection patients after endovascular stent graft repair. Five patients were included in this study: 2 have more than 80% false lumen thrombosis (group 1), while 3 others had less than 80% false lumen thrombosis (group 2) within 1 year following endovascular repair. Group 1 patients had concentrated re-entry tears around the abdominal branches only, while group 2 patients had re-entry tears that spread along the dissection line. Blood flow inside the false lumen which affected thrombus formation increased with the number of re-entry tears and when only small amounts of blood that entered the false lumen exited through the branches. In those cases where dissection extended below the abdominal branches (group 2), patients with fewer re-entry tears and longer distance between the tears had low wall shear stress contributing to thrombosis. This work provides an insight into predicting the development of complete or incomplete false lumen thrombosis and has implications for patient selection for treatment.

Inflammation is related to preoperative hypoxemia in patients with acute Stanford type A aortic dissection

Background

Preoperative hypoxemia is a frequent complication of acute Stanford type A aortic dissection (ATAAD). The aim of the present study was to determine which factors were associated with hypoxemia.

Methods

A series of data were collected in a statistical analysis to evaluate preoperative hypoxemia in patients with ATAAD. After retrospectively analyzing data for 172 patients, we identified the risk factors for preoperative hypoxemia. Hypoxemia was defined by an arterial partial pressure of oxygen to fraction of inspired oxygen (PaO₂/FiO₂) ratio of 200 or lower. Subsequent to identifying the patient population, a prospective study was conducted using ulinastatin as a preoperative intervention. The ulinastatin group received ulinastatin at a total dose of 300,000 units prior to surgery. All the pertinent factors were investigated through univariate and multiple logistic regression analysis.

Results

The factors associated with preoperative hypoxemia in ATAAD comprised the following: body mass index (BMI) ≥25; white blood cell count (WBC) and neutrophil counts; levels of C-reactive protein (CRP), D-dimer, and interleukin-6 (IL-6); ATAAD involving the celiac trunk, renal artery, or mesenteric artery. Logistic regression analysis showed that CRP and IL-6 levels were independent predictive factors. We found that ulinastatin effectively could improve oxygenation, since compared to the control group the oxygenation in the ulinastatin group was significantly improved.

Conclusions

Systemic inflammatory reactions played a vital role in preoperative hypoxemia after the onset of ATAAD. The oxygenation of the patient could be improved significantly by inhibiting the inflammatory response prior to surgery.

How should we manage type B aortic dissections?

Dissection of the descending aorta is a serious and potentially lethal event. Treatment options consist of medical therapy, open surgical replacement of the affected aorta and thoracic endovascular repair. In acute cases, medical treatment is started initially. When complicated, endovascular repair is generally considered as first choice treatment, except for connective tissue disorders where open surgery remains the standard. In stable, uncomplicated patients with risk factors for future aortic growth pre-emptive endovascular repair should be considered in the sub-acute phase of the dissection. The treatment strategy in chronic dissections is somewhat debated. Long-term results and aortic remodeling of endovascular repair are disappointing and open surgery remains the standard.

Use of the frozen elephant trunk technique in complicated chronic dissection with porcelain aorta and visceral arteries originating from different lumens

A rare case of aortic arch aneurysm combined with chronic aortic dissection is reported. Because the visceral arteries originated from different, equivalently perfused lumens and the descending aorta was circumferentially calcified (porcelain aorta) limiting the possibilities of anastomosing, careful planning of the surgical strategy was of utmost importance. The complex surgery consisted of ascending and total arch replacement using the 'frozen elephant trunk' technique with Thoraflex™ Hybrid Prosthesis (Vascutek, Terumo, Inchinnan, Scotland); however, before insertion of the stent graft, an angioscopic resection of the dissection membrane in the proximal part of the descending aorta was carried out to ensure a complete expansion of the distal edge of the stent within the entire common lumen of the aorta and unimpaired distal flow in both lumens below the stent graft. The surgery and the postoperative course were uneventful.

Candy-Plug Technique Using an Excluder Aortic Extender for Distal Occlusion of a Large False Lumen Aneurysm in Chronic Aortic Dissection

PURPOSE

To describe the candy-plug technique using an Excluder aortic extender for distal occlusion of a large false lumen aneurysm in chronic aortic dissection.

TECHNIQUE

A 60-year-old female patient with a history of chronic type B aortic dissection and high-dose steroid use for Churg-Strauss syndrome developed a large 6.2 cm maximum diameter false lumen aneurysm. She underwent thoracic endovascular aortic repair from the left common carotid artery to the descending aorta to cover the proximal entry at the level of distal arch, with coil embolization of the left subclavian artery. To occlude the large false lumen from the reentry just below the level of the left renal artery ostium, a modified 32×45-mm Excluder aortic extender was deployed in the false lumen through the reentry, and a 16-mm Amplatzer Vascular Plug I was deployed in the waist of the modified Excluder aortic extender for complete occlusion. No obvious technical complication was seen. Contrast-enhanced computed tomography at 1 and 14 months revealed no endoleaks and showed complete false lumen thrombosis.

CONCLUSION

The candy-plug technique using the Excluder aortic extender is feasible for occlusion of a large false lumen aneurysm in chronic aortic dissection.

Risk factors for distal stent graft-induced new entry following endovascular repair of type B aortic dissection

BACKGROUND

Distal stent graft-induced new entry (DSINE) has been increasingly observed following thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD). We seek to identify the risk factors for DSINE following TEVAR in patients with TBAD.

METHODS

Between January 2009 and January 2013, we performed TEVAR for 579 patients with TBAD. The clinical data were retrospectively analyzed with univariate and multivariate analyses to identify the risk factors for DSINE.

RESULTS

Two patients (0.3%) died after the initial TEVAR. Morbidity included spinal cord injury in 2 (0.3%), stroke in 3 (0.5%) and endoleak in 12 (2.1%) patients. Clinical and radiological follow-up was complete in 100% (577/577) averaging 47±16 months. Late death occurred in 6 patients. DSINE occurred in 39 patients (6.7%) at mean 22±17 months after the initial TEVAR, which was managed with re-TEVAR in 25 and medically in 14. At 33±18 months after DSINE, 11 of patients managed medically (11/14) and all patients managed with re-TEVAR (25/25) survived (P=0.048). Freedom from DSINE was 92.7% at 5 years (95% CI: 90.0-94.7%). Using tapered stent grafts with a proximal end 4-8 mm larger than the distal end, TEVAR performed in the acute phase (≤14 days from onset) was associated with a significantly lower incidence of DSINE than TEVAR performed in the chronic phase (4.3%, 7/185 vs. 13.9%, 15/108; P=0.003). Risk factors for DSINE were stent grafts less than 145 mm in length [odds ratio (OR) 2.268; 95% CI: 1.121-4.587; P=0.023] and TEVAR performed in the chronic phase (OR 1.935; 95% CI: 1.004-3.731; P=0.049).

CONCLUSIONS

Our results show that TEVAR performed during the acute phase and using stent grafts longer than 145 mm could decrease the incidence of DSINE in patients with TBAD. Tapered stent grafts with a proximal end 4-8 mm larger than the distal end may be helpful in preventing DSINE after TEVAR performed in the acute phase than TEVAR performed in the chronic phase, due to the difference in mobility of the dissected flap. Expedite repeat TEVAR is recommended to improve the clinical prognosis for patients with DSINE.

Hybrid Approach to Management of Complex Aortic Arch Pathologies: A Single-Center Experience in China

BACKGROUND

The purpose of this study is to summarize a single-center experience and midterm outcomes of a combined supra-aortic debranching and thoracic endovascular aortic repair (TEVAR) for hybrid operation on patients with complex aortic arch disease.

METHODS

From 2012 to 2015, 43 consecutive patients (37 male and 6 females) who underwent a hybrid operation for complex aortic arch disease were retrospectively analyzed. Of the 43 patients, 12 were diagnosed with type A aortic dissection (AD), 27 with complicated type B AD involving the aortic arch, 2 with aortic arch aneurysm, and 2 with type A penetrating atherosclerosis ulcer.

RESULTS

The patients' mean age was 52.3 ± 11.3 years. Hybrid operation was technically successful in all patients. The overall 30-day mortality and in-hospital mortality rates were 2.3% (1 of 43), with 1 patient dying at days 18 of severe aspiration pneumonia after procedure. Thirty-day paraplegia and stroke were 0%. Complication included 1 newly onset renal insufficiency and type II endoleak. After a median follow-up of 15 months (range, 6-26 months), the overall mortality was 7.1% (3 of 42), with Kaplan-Meier survival estimate of 91% at 1 year. Only one late death was considered aorta-related. computed tomography (CT) scanning was performed at 6 months and annually thereafter, and 2 patients were observed with type Ib endoleak and type II endoleak, respectively. For the patient with type Ib endoleak, distal extension was performed successfully. No late extra-anatomic bypass occlusion and stent-graft migration were found on CT scans or ultrasound.

CONCLUSIONS

These initial results suggest that hybrid operation with supra-aortic debranching, and TEVAR is an acceptable treatment option for patients with complex aortic arch disease. Short-term and midterm outcomes are acceptable. Further research with large sample size and long-term follow-up is needed.

Open aortic arch surgery in chronic dissection with visceral arteries originating from different lumens

OBJECTIVES

Surgical management of chronic aortic dissection is controversial, especially when the dissection extends into the abdominal aorta in which the visceral arteries originate from different lumens and is combined with aortic arch pathology necessitating surgery. The aim of the study was to evaluate the results of open surgery in this complex aortic pathology.

METHODS

Between June 2002 and 2015, a total of 17 patients (median age 57, range 32-76 years) necessitating complete arch replacement presented complex chronic dissection of the thoraco-abdominal aorta with the visceral arteries originating from different lumens. Fourteen patients (82%) had had previous cardiac surgery, which was performed on the proximal aorta in all but one because of acute type A dissection. Nine patients without considerable dilatation of the descending aorta received aortic arch replacement with distal resection of the dissection membrane, and 8 patients with progressive dilatation of the thoracic aorta underwent aortic arch and descending aorta replacement via clamshell approach.

RESULTS

No early (defined as 30-day, 90-day and in-hospital period) deaths, strokes or spinal cord injuries occurred. Only 1 patient (6%) presented temporary neurological dysfunctions (delirium, agitation), which resolved completely before discharge, and an injury of the recurrent laryngeal nerve was documented in 2 patients (12%). Temporary dialysis was necessary in 1 case. The follow-up was complete for all patients. All but one patient, who died due to leukaemia 23 months after surgery, were alive at the last follow-up (median duration 33 months, range 2-118 months). No patient needed a reoperation or an intervention on the thoracic and/or abdominal aorta. Moreover, no noticeable progression of the chronic dissection in the downstream aorta was documented in any patient.

CONCLUSIONS

The results after conventional aortic arch repair with distal resection of the dissection membrane and, if necessary, with replacement of the progressively dilated chronic dissected thoracic aorta can offer excellent results in experienced hands and, therefore, this technique may be considered as a preferable option for surgical treatment of chronic aortic dissection with involvement of the aortic arch and the visceral arteries originating from different lumens.