Aneurysm Expansion and Retroperitoneal Hematoma After Thrombolysis for Stent-Graft Limb Occlusion Caused by Distal Endograft Migration

Aneurysm Sac Re-Expansion After Thrombolysis

PURPOSE

To present a case of delayed abdominal aortic aneurysm (AAA) re-expansion after thrombolysis for endograft limb occlusion.

CASE REPORT

A 68-year-old man underwent AAA exclusion with an AneuRx stent-graft in 1999. Five years later, he developed right limb thrombosis of the endograft. He underwent right limb thrombolysis and AngioJet thrombectomy. The patient experienced abdominal and back pain during the procedure, and the aneurysm sac, which had remained reduced in size for several years, acutely re-expanded. The patient was managed conservatively. The fluid that accumulated in the sac was reabsorbed, and the AAA returned to its previous dimensions at 1-month follow-up.

CONCLUSION

Symptomatic re-expansion of the aneurysm sac after AngioJet rheolytic thrombectomy may occur when the graft is stripped of neointima by the "power-pulse" spray of lytic agent, allowing serum to seep into the sac. Based on this experience, we advise caution when delivering thrombolytics using the AngioJet "power-pulse" spray mode in patients with a thrombosed stent-graft.

Assessment of Automatic Vessel Tracking Techniques in Preoperative Planning of Transluminal Aortic Stent Graft Implantation

OBJECTIVE

To evaluate automatic vessel tracking techniques in the course of preoperative planning prior to transluminal aortic endograft implantation by comparing accuracy, reproducibility, and postprocessing time with source image and volume-rendered analysis methods.

METHODS

Multislice computed tomography datasets of 5 patients with abdominal aortic aneurysms were preoperatively examined, performing volumetric analysis of diameter and position of renal artery orifices, aneurysmal neck, maximal aneurysmal extension, aortic bifurcation, and iliac arteries and bifurcation. Analysis was realized by utilizing transverse datasets, volume rendering, and automated vessel tracking strategies (MxView, Philips, Best, The Netherlands). Measurement techniques were evaluated by 2 independent readers 3 times for each patient and measurement modality. Statistical analysis evaluated accuracy of the measurements and intra- and interobserver reliability. Postprocessing time was documented.

RESULTS

Using transverse source datasets, intraobserver reliability ranged from 0.49 to 0.58. Intraobserver reliability improved to 0.7 to 0.98 when volume-rendered datasets were evaluated. Interobserver variability for transverse and volume-rendered datasets ranged from 0.49 to 0.76 and 0.70 to 0.96, respectively. Automated vessel tracking datasets did not demonstrate any intra- or interobserver variability. Based on transverse datasets, the length and diameter of iliac arteries and location and diameter of the aneurysmal neck were measured as statistically different in all cases in contrast to volume rendering and automated segmentation techniques. Postprocessing time consumption for measurements based on transverse, volume-rendered, and automated tracking segmentation datasets averaged 3.32 minutes, 25.43 minutes, and 2.24 minutes, respectively.

CONCLUSIONS

Preoperative measurements improve significantly if datasets are evaluated based on volume-rendering techniques. This time-consuming procedure can be shortened, while further reducing observer variability, with automatic segmentation techniques.