Custom Made Candy Plug for Distal False Lumen Occlusion in Aortic Dissection: International Experience

Critical Review of Guidelines for Type B Aortic Dissection

The management of type B aortic dissection is one of the most challenging and debated topics in contemporary cardiovascular surgery practice. Patients with acute or chronic dissection-related complications face high morbidity and mortality if not treated promptly. For most patients requiring intervention, thoracic endovascular aortic repair (TEVAR) is considered the gold standard. However, both early and late TEVAR-related complications make decision-making complex, even for experienced clinicians. In many cases, optimal medical management with longitudinal imaging surveillance may be preferred. In response to these challenges, several societal guidelines have recently been published to provide evidence-based or expert consensus "best practice" recommendations. Although these guidelines share many commonalities, they also highlight key unresolved clinical questions. For example, debates persist over the appropriate use of TEVAR for "uncomplicated" TBAD, defining "high-risk" criteria for uncomplicated presentations, and management of the false lumen, among other topics. Despite recent updates, a critical evaluation of the nuanced differences between these guidelines is lacking. Therefore, the purpose of this review is to compare current clinical practice guidelines, highlight their similarities and differences, and offer a comprehensive evaluation of the evidence surrounding management of TBAD. Moreover, this analysis will provide recommendations to address important knowledge gaps.

Complete Endovascular Repair of Entire Aorta for Extensive Pathologies - A Set of China Strategies

BACKGROUND

Endovascular aortic repair was introduced in China in 1997, with domestically produced devices emerging post-2000. Despite progress, treatment of complex aortic pathologies remains limited, necessitating innovative endovascular solutions.

METHODS

Our center developed 8 off-the-shelf endovascular innovations, including 3 inner branch stent graft systems for aortic arch reconstruction, 2 branched/fenestrated stent grafts for thoracoabdominal and juxtarenal aortic aneurysms, 1 iliac branch device for internal iliac artery preservation, and 2 novel devices-EndoPatch and EndoSeal (Endonom Medtech)-designed to seal distal tears and occlude false lumen in aortic dissections. These advancements integrate technologies such as steerable delivery systems, preloaded navigation aids, and mixed or inner branch configurations to accommodate anatomical variations.

RESULTS

Preliminary clinical applications demonstrated promising technical success rates and acceptable complication profiles. Two devices have been approved by China's National Medical Products Administration for clinical use, while others remain under investigation. Key challenges include anatomical variability, branch vessel patency concerns, and the absence of long-term outcomes for most devices.

CONCLUSION

These innovations establish a comprehensive endovascular strategy for extensive aortic pathologies, addressing critical gaps in China's device landscape. Early outcomes demonstrate the feasibility of standardized off-the-shelf solutions for complex anatomies, though multicenter trials and long-term follow-up remain essential to confirm safety and efficacy.

Aortic Remodeling After False Lumen Embolization in Aortic Dissection

Background/Objectives: Retrograde false lumen perfusion after thoracic endovascular aortic repair (TEVAR) can compromise positive remodeling and clinical outcomes. The aim of this study is to describe the feasibility and outcomes of a false lumen thrombosis technique. Methods: A single-center, retrospective analysis of patients between January 2017 and January 2022 who underwent TEVAR in conjunction with false lumen embolization. Results: Twelve patients (83% type A, 17% type B; 33% with frank rupture; mean age 65 years; eleven men) underwent 13 false lumen embolization procedures with a 92% technical success rate and a 100% clinical success rate. Positive aortic remodeling was observed in all the patients. The maximum thoracic aortic diameter remained stable (p = 0.526) but the true lumen increased from 22 to 33 mm (p = 0.009) and the false lumen decreased from 41 to 20 mm (p = 0.076) after a median follow-up of 31 months. Conclusions: False lumen embolization using the candy-plug is safe and promotes positive aortic remodeling.

False Lumen Patency After Occlusion With Physician-Modified Candy-Plug in Aortic Dissections: A 2-Center Experience

OBJECTIVE

To evaluate the early and mid-term results of physician-modified candy-plug (pmCP) in patients with type-B or residual type-A aortic dissection (TBRAD).

METHODS

All patients with TBRAD who received false lumen (FL) occlusion with pmCP between September 2018 and May 2024 were analyzed. Primary outcomes were technical and clinical success, and overall mortality. Secondary outcomes were postoperative aortic remodeling and aortic reintervention.

RESULTS

Seventeen patients (88% male; mean age 69±12 years) underwent FL occlusion with a pmCP. Nine patients (53%) were emergently treated. The technical and clinical successes were 100% and 82%, respectively. One patient (6%) died postoperatively. Early complete FL occlusion was observed in 82% of the patients. One patient (6%) required an early pmCP-related reintervention. During a mean follow-up of 15±5 months, 75% of the patients had complete thoracic FL thrombosis while 13% of them aortic remodeling in the last computed tomography (CT) scan. Aneurysm size remained stable in 69% of the cases. There were no aortic-related re-interventions during follow-up.

CONCLUSIONS

The pmCP technique is a feasible and promising alternative technique, with high primary technical and clinical success rate. Stable aortic diameters can be expected during follow-up, thus reducing the need for further aortic reintervention.

CLINICAL IMPACT

Persistence of false lumen (FL) patency after thoracic endovascular aortic repair (TEVAR) for thoracic aortic dissection (TBAD) remains a significant challenge for physicians. Various strategies have been developed to address retrograde FL patency, including the candy-plug technique. This technique involves modifying thoracic stent grafts and placing an additional plug to occlude the reduced stent graft waist.Since its introduction, three generations of custom-made candy-plug devices (Cook Medical, Bloomington, IN, USA) have been developed. However, delivery times vary across countries and vascular surgery services, complicating procedural planning, particularly in symptomatic patients or cases of rapid FL diameter progression.In this study, we provide a step-by-step description of the physician-modified candy-plug technique and present our preliminary results.

Urgent Candy-Plug technique for distal false lumen occlusion in chronic aortic dissection

OBJECTIVE

This study aimed to assess the impact of urgency on early and midterm outcomes of the Candy-Plug (CP) technique for distal false lumen (FL) occlusion in thoracic endovascular aortic repair for aortic dissection.

METHODS

The CP registry was reviewed, and patients were categorized into elective and urgent/emergent groups for analysis. End points included technical success, clinical success, early (30-day) computed tomography angiography findings, early (30-day) mortality, adverse events, and aortic remodeling in patients with available computed tomography angiography follow-up and reintervention.

RESULTS

A total of 155 patients received a custom-made CP, of whom 32 patients (44% male, mean age 61 ± 9 years) were treated urgently and 123 patients (63% male, mean age 62 ± 11 years) electively. The primary CP rate was higher in the urgent group (28/32, 88%, in the urgent group vs 96/123, 78%, in the elective group, P = .051). The mean contrast volume was higher in the urgent group (157 ± 56 mL in the urgent group vs 130 ± 71 mL in the elective group, P = .017). Technical success was achieved in all patients in both groups. Clinical success was achieved in 25 of 32 (78%) patients in the urgent group vs 113 and 123 (92%) in the elective group (P = .159). The early mortality rate was 13% (4 of 32 patients) in the urgent group vs 1% (1 of 123 patients) in the elective group (P = .120). There was no statistically significant difference regarding the early adverse events between the urgent and elective CP groups. Early aortic-related reinterventions were required in 6 of 32 (19%) patients in the urgent group vs 6 of 123 (5%) in the elective group (P = .094). Thoracic aortic aneurysm sac regression was lower in the urgent group (5/28, 18%, in the urgent group vs 63/114, 55%, in the elective group, P = .001). Stable thoracic aortic aneurysm sac was higher in the urgent group (22/28, 79%, in the urgent group vs 47/114, 41%, in the elective group, P = .000). An increase in thoracic aortic aneurysm sac occurred in 1 of 28 (4%) patients in the urgent group vs 4 of 114 (4%) patients in the elective group (P = .096).

CONCLUSIONS

The urgent use of the CP technique for distal FL occlusion in aortic dissection was feasible and effective. The decrease in aortic FL sac diameter may be affected by the urgent use of CP due to limited sizing availability. However, it achieved a high rate of aortic remodeling.

Physician-modified funnel-shaped covered stent for selective false lumen exclusion in chronic type B aortic dissection

PURPOSE

To describe the technique of off-centering a balloon-expandable covered stent for selective occlusion of a distal entry tear (ET) in a patient, conservatively treated for chronic type B aortic dissection (cTBAD), presenting FL expansion.

TECHNIQUE

A 63-year-old male, with conservatively managed cTBAD, presented at follow-up with FL partial thrombosis and expansion (thoracic aorta FL from 21 mm to 27 mm and abdominal aorta FL from 11 mm to 15 mm in 6 months). No proximal ET was identifiable. Distal FL perfusion was caused by an ET in the abdominal aorta feeding a 2 mm accessory renal artery (ARA). As the aortic diameter was below the threshold for endovascular repair, a selective occlusion of the distal ET and ARA was planned. A balloon-expandable covered stent was modified by off-centering the covered stent proximally and resulting in a funnel-shape occluder after deployment across the ET into the ARA. To prevent type Ic endoleak due to possible FL expansion caused by an intra-operatively detected phrenic artery (PA), coils were deployed into the lumen of the modified stent and the ARA. The pre-discharge computed tomography angiography showed exclusion of both the ARA and ET and a type 2 endoleak from the PA.

CONCLUSION

A balloon-expandable covered stent can be modified by off-centering the covered stent resulting in a funnel shape to adapt to different diameter requirements.

Post-dissection Thoraco-abdominal Aortic Aneurysm Managed by Fenestrated or Branched Endovascular Aortic Repair

OBJECTIVE

Fenestrated or branched endovascular aortic repair (F/B-EVAR) is a valuable treatment in patients with chronic post-dissection thoraco-abdominal aneurysm (PD-TAAA). This study aimed to analyse early and follow up outcomes of F/B-EVAR in these patients.

METHODS

Thirty day and follow up outcomes of consecutive patients with PD-TAAA treated with F/B-EVAR in a tertiary centre over eight years were analysed retrospectively. All patients presenting with PD-TAAA and managed with F/B-EVAR were eligible. A modified Crawford's classification system was used. Thirty day mortality and major adverse event (MAE) rates were analysed. Time to event data were estimated with Kaplan-Meier survival analysis.

RESULTS

Fifty five patients (80% men, mean age 63.7 ± 7.7 years) were included: 12 (22%) were managed urgently; 25 (46%) for chronic type B aortic dissection; and the remainder for residual type A aortic dissection. Of these patients, 88% had undergone previous thoracic endovascular aortic repair. Prophylactic cerebrospinal fluid drainage (CSFD) was used in 91%. Fifteen (27%) patients were treated with F-EVAR, nine (16%) with fenestrations and branches, and 31 (56%) with B-EVAR. False lumen adjunctive procedures were used in 56%. Technical success was achieved in 96% of patients. The thirty day mortality rate was 7% and MAE rate was 20%. Spinal cord injury (SCI) grades 1 - 3 and grade 3 rates were 13% and 2%, respectively. Mean follow up was 33.0 ± 18.4 months. Survival and freedom from unscheduled re-intervention were 86% (standard error [SE] 5%) and 55% (SE 8%) at 24 months, respectively. Freedom from target vessel stenosis and occlusion was higher in F-EVAR at the 12 month follow up (p = .006) compared with B-EVAR.

CONCLUSION

Fenestrated or branched endovascular repairs in patients with PD-TAAA showed high technical success, with acceptable early mortality and MAE rates. The SCI rate was > 10%, despite CSFD use and staged procedures. Almost a half of patients needed an unscheduled re-intervention within 24 months after F/B-EVAR.

Design, evolution, and experience with the candy plug device for endovascular false lumen occlusion of chronic aortic dissections

INTRODUCTION

The management of the false lumen (FL) when dealing with aortic dissection is a crucial aspect since inducing its thrombosis is necessary in order to achieve aortic remodeling. One of the pitfalls of endovascular treatment of aortic dissection (AD) is retrograde distal FL perfusion and pressurization, which prevents FL thrombosis and thus aortic remodeling, while being associated with aneurysmal degeneration of the FL and poor long-term outcomes.

AREAS COVERED

Currently, there is no CE/FDA approved device for FL closure, however different techniques and devices have been proposed to overcome this challenge, the most known of which is the Candy Plug (CP). This review aims to describe the CP device, its implantation technique, and the available data in the literature (PubMed, Cochrane, and EMBASE databases; last queried, December 31, 2023).

EXPERT OPINIONS

While the treatment of AD remains technically challenging, the use of the CP technique to close any distal FL reperfusion proved to be feasible and safe with excellent rates of both technical and clinical success. Furthermore, recent studies have shown a quick learning curve with this technique.

Plug-Based Embolization Techniques of Aortic Side Branches during Standard and Complex Endovascular Aortic Repair

Vascular plugs are an evolving family of vessel occluders providing a single-device embolization system for large, high-flow arteries. Nitinol mesh plugs and polytetrafluoroethylene membrane plugs are available in different configurations and sizes to occlude arteries from 3 to 20 mm in diameter. Possible applications during complex endovascular aortic procedures are aortic branch embolization to prevent endoleak or to gain an adequate landing zone, directional branch occlusion, and false lumen embolization in aortic dissection. Plugs are delivered through catheters or introducers, and their technical and clinical results are comparable to those of coil embolization. Plugs are more accurate than coils as repositionable devices, less prone to migration, and have fewer blooming artifacts on postoperative computed tomography imaging. Their main drawback is the need for larger delivery systems. This narrative review describes up-to-date techniques and technology for plug embolization in complex aortic repair.

Transcatheter electrosurgical septotomy technique for chronic postdissection aortic aneurysms

Aortic dissection often results in chronic aneurysmal degeneration due to progressive false lumen expansion. Thoracic endovascular aortic repair and other techniques of vessel incorporation such as fenestrated-branched or parallel grafts have been increasingly used to treat chronic postdissection aneurysms. True lumen compression or a vessel origin from the false lumen can present considerable technical challenges. In these cases, the limited true lumen space can result in inadequate stent graft expansion or restrict the ability to reposition the device or manipulate catheters. Reentrance techniques can be used selectively to assist with target vessel catheterization. Transcatheter electrosurgical septotomy is a novel technique that has evolved from the cardiology experience with transseptal or transcatheter aortic valve procedures. This technique has been applied in select patients with chronic dissection to create a proximal or distal landing zone, disrupt the septum in patients with an excessively compressed true lumen, or connect the true and false lumen in patients with vessels that have separate origins. In the present report, we summarize the indications and technical pitfalls of transcatheter electrosurgical septotomy in patients treated by endovascular repair for chronic postdissection aortic aneurysms.

Visceral Aorta Electrocautery Septotomy to Allow Branched Endovascular Aortic Repair in Ruptured Chronic Post-Dissection Thoraco-Abdominal Aneurysm

PURPOSE

Endovascular repair of chronic post-dissection thoraco-abdominal aortic aneurysms (PD-TAAA) presents specific technical challenges due to the presence of chronic septum. Small true lumen diameter and false lumen visceral vessel origin can make branched endograft prohibitive. Septotomy may allow to overcome these challenges in cases of high complex anatomy.

TECHNIQUE

We describe the application of electrocautery septotomy to the visceral aorta segment to deploy an off-the-shelf branched endograft in a chronic PD-TAAA rupture with true lumen collapse.

CONCLUSIONS

Electrocautery septotomy can be an effective adjunctive technique to facilitate branched endograft, overcoming technical challenges associated with the endovascular treatment of chronic PD-TAAA.

CLINICAL IMPACT

Electrocautery septotomy is an adjunctive technique that can facilitate endovascular treatment of post-dissection thoraco-abdominal aneurysm. By creating a common lumen, this technique might reduce the number of re-interventions associated with PD-TAAA endovascular exclusion.

Open and endovascular reinterventions after Candy Plug false lumen embolization of type B aortic dissection

OBJECTIVE

In the majority of patients with chronic type B aortic dissection, there is persistent retrograde flow in the false lumen (FL) through distal re-entry tears. Among several endovascular techniques proposed for FL management, the "Candy Plug" (CP) technique has gained acceptance with good early results. The aim of this study is to report the types and outcomes of open and endovascular reinterventions and identify mechanisms of procedure failure as well as other causes for reinterventions.

METHODS

All patients with type B aortic dissection submitted to thoracic endovascular aneurysm repair and CP implantation for FL embolization from January 2016 to December 2022 at our institution were included in this study. The preoperative, intraoperative, and postoperative data of the primary intervention and secondary reinterventions, when performed, were prospectively collected and retrospectively analyzed. Preoperative and postoperative computed tomography angiography were also analyzed.

RESULTS

During the study period, 33 patients were submitted to thoracic endovascular aneurysm repair and CP implantation. Twenty-three patients (69.7%) showed thoracic FL complete thrombosis with aortic stability or positive remodeling at a mean follow-up of 45 ± 23.1 months. Ten patients (30.3%) underwent aortic reinterventions (male, n = 9; mean age, 60.5 ± 7.6 years). Of these 10 patients, in four patients, complete thrombosis of the FL was never achieved, leading to ongoing perfusion of the FL, defined as "primary failure." The other six patients underwent reinterventions for different causes: two patients, after initial sealing, showed a progressive enlargement of the abdominal FL leading to distal degeneration. One patient showed proximal degeneration, two patients showed a type II thoracoabdominal aortic aneurysm and CP implantation was used as a planned procedure to reduce the extent of the surgical procedure, and one patient had recurrent, intractable back pain despite complete thrombosis of the FL. Reinterventions were open in five cases and endovascular in five. One in-hospital death (postoperative day 27) after a type II thoracoabdominal aortic aneurysm open repair was recorded. In addition, two cases of delayed spinal cord ischemia after open reintervention were recorded: one resulting in permanent paraplegia and one transitory with complete recovery.

CONCLUSIONS

The CP technique was safe and effective; however, a significant rate of aortic-related reintervention was observed. Several mechanisms led to reinterventions either in terms of "primary failure" of the CP or subsequent aneurysmal degeneration. Complex reinterventions were often necessary, with a high rate of major complications in case of open repair. Life-long and closer surveillance might be required in these patients.

Atrial septal defect occluder combined with stent graft for the management of post-dissection aortic aneurysm previously treated with unsuccessful coils: a case report

BACKGROUND

Although the candy-plug technique has been reported to be useful for the treatment of post-dissection aortic aneurysm, the stent graft needs be to customized to accommodate the size of vascular occluders.

CASE PRESENTATION

We present a case of a persistent false lumen successfully treated with endovascular stent-graft and atrial septal defect occluder in a patient with Stanford Type B dissection. A covered stent graft was implanted into the false cavity through a distal rupture, and an atrial septal defect occluder was inserted into the covered stent to seal of the false cavity. Decreased aneurysmal diameter and false lumen thrombosis were noted by CT scan at 6-month follow-up.

CONCLUSIONS

Our case showed that combined use of a stent graft and atrial septal defect occluder is safe, technically feasible and effective in sealing of the false lumen in post-dissection aortic aneurysm patients with previously failed false lumen thrombosis.

Evaluation of false lumen occluders implanted in the abdominal aorta false lumen

OBJECTIVE

Management of postdissection thoracoabdominal aneurysms with a fenestrated and/or branched endograft (F/BEVAR) is associated with favorable outcomes. Treatment should include both true lumen endografting and false lumen occlusion (FLO). Favorable results have recently been reported for FLO in the false lumen of the thoracic aorta. The purpose of this study is to analyze the results of FLO of the abdominal aorta in patients treated for post dissection thoracoabdominal aneurysm.

METHODS

A multicenter retrospective analysis of prospective data of consecutive patients managed for post dissection thoracoabdominal aortic aneurysm from April 2019 to December 2022 with F/BEVAR associated with FLO in the abdominal false lumen was conducted. The STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) was followed. Baseline demographics, operative details, and early outcomes (mortality, length of stay) were recorded. Primary endpoints were technical and clinical success. FLO technical success was defined as complete occlusion of false lumen backflow above the FLO on completion angiogram.

RESULTS

During the 3-year study, 23 patients were treated for post dissection thoracoabdominal aneurysm with F/BEVAR and the use of abdominal FLO. Twenty-one patients (91.3%) had received prior endovascular treatment. The technical and clinical success was 95.7%. The abdominal FLO had a technical success rate of 78.3%. The median diameter of the FLO was 34 mm. No patient died during the perioperative period, and one patient had spinal cord ischemia (4.3%) with partial recovery. Six patients (26.1%) required early reintervention. The median duration of hospitalization in the intensive care unit and overall was 1 day (interquartile range, 0-3 days) and 7.5 days (interquartile range, 2-22 days), respectively. During the mean follow-up of 9.9 ± 9.0 months, no patient died. False lumen occlusion was complete or partial in nine (39.1%) and nine (39.1%) patients, respectively. No aortic rupture occurred during follow-up. Maximum aortic diameter decreased in 48% and remained stable in 39% of cases.

CONCLUSIONS

Abdominal aorta FLO during endovascular treatment of post dissection thoracic abdominal aortic aneurysm is associated with favorable outcomes. It offers an additional staging therapeutic option before extensive aorto-bi-iliac coverage, associated with low spinal cord ischemia rates. FLO also provides high rates of false lumen occlusion and false lumen remodeling during follow-up. Longer follow-up and larger cohorts are required to confirm these very promising early findings.