Coil-assisted false lumen thrombosis in complicated chronic type B dissection

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.

Persistent Intraluminal Pressure After Endovascular Stent Grafting for Type B Aortic Dissection

OBJECTIVES

Despite technically successful thoracic endovascular stent graft repair (TEVAR) in patients with Stanford Type B aortic dissection (TBAD), long-term follow up studies have shown that the false lumen may continue to dilate. The aim of this study was to analyze the possible mechanisms leading to such changes from a hemodynamic perspective.

METHODS

Twenty-eight ex vivo fresh porcine TBAD models (Mo A: 10; Model B: 12; Model C: 6) were established to simulate three clinical situations: Model A with patent false lumen (pre-TEVAR); Model B with distal re-entry only (post-TEVAR), and Model C with thrombus filling in the false lumen and a distal re-entry (chronic stage of post-TEVAR). Synchronous pressure waveforms were taken from both the true and the false lumen. True lumen and false lumen pressure differences were calculated for each model as four indices: systolic index (SI), diastolic index (DI), mean pressure index (MPI) and area under curve index (AUCI). These indices were compared between the three models.

RESULTS

False lumen pressure and corresponding pressure-accumulating effects were significantly higher in Model A than in Model C: SI (99.9% vs. 189.4%; p < .001); MPI and AUCI (99.5% vs. 128.2%; 99.5% vs. 128%; p < .001). The SI, MPI, and AUCI were significantly higher in Model B compared with Model C. The differences between the four indices were not significant between Model A and B. The false lumen area under curve (AUC) in Model C was merely lowered by 20% compared with its true lumen (67.5 mmHg vs. 85.2 mmHg).

CONCLUSION

The false lumen pressure remained unchanged in the non-thrombosed segment with patent blood flow after the primary entry tear sealed. Intraluminal pressure reduction in the thrombosed false lumen was significant. However, nearly 80% of the pressure remained in the thrombosed false lumen. If this high intra-thrombus pressure persists, it may contribute to delayed aneurysmal formation after endovascular treatment.

Aorta Remodeling after Endovascular Treatment of a Chronic DeBakey IIIb Aneurysm and Simultaneous Palliation of a Renal Cell Carcinoma

We report the case of a patient with a chronic DeBakey type IIIb aneurysm who underwent thoracic endovascular aortic repair to seal the primary entry tear and stent-graft insertion to cover the re-entry tear at the renal artery. The procedure was performed in order to achieve complete thrombosis in the entire thoracoabdominal false lumen, leading to favorable aortic remodeling. Simultaneously, ethanol ablation and renal artery embolization were performed to treat a renal tumor suspicious of renal cell carcinoma. Radical nephrectomy then confirmed clear cell carcinoma. To the best of our knowledge, no other cases of this type have been reported in the Korean literature.

Persistent type B aortic dissection treatment by renal artery reentry stent grafting as an alternative to open surgery

Type B aortic dissections complicated by pain, malperfusion, or aneurysm expansion mandate surgical intervention. Success of this therapy is predicated on exclusion and thrombosis of the false lumen of the aneurysm. This report presents a case in which cessation of flow was achieved using a covered stent graft to close a renal reentry tear after a previous closing and overstenting of the main tear. This approach may provide a helpful adjunct to the endovascular treatment of complicated type B aortic dissections.