Palliative Percutaneous Cryoablation and Cementoplasty of Acetabular Metastases: Factors Affecting Pain Control and Fracture Risk.

PURPOSE: To characterize the response of patients with acetabular metastases following combined cryoablation and cementoplasty (CCC) for pain palliation and fracture risk reduction, based on completeness of ablation and the presence of pre-existing pathologic fracture. MATERIALS AND METHODS: Thirty-nine consecutive acetabular CCC procedures were performed in 37 patients (24 M:13F, age 66 ± 8 years). Pain was assessed using a 0-10 numeric rating scale. Development of new or progression of pre-existing fractures and local tumor progression (LTP) were determined on follow-up imaging. Pain score reduction and fracture development rates were compared by ablation completeness and the presence of pre-existing fractures. RESULTS: Twenty-three of 27 (85%) patients with evaluable pain scores had reduced pain, decreasing from 7.5 ± 2.1 to 3.6 ± 2.6 (p < 0.0001). Of 39 tumors, 28 (72%) were completely ablated with no significant difference in pain reduction after complete versus incomplete ablations (p = 0.9387). Six of 30 (20%) patients with follow-up imaging demonstrated new/progressive acetabular fractures. Four of 5 (80%) patients with LTP developed new/progressive fractures compared to 2 of 25 (8%) without tumor progression (p = 0.0003). Pre-existing fracture was not associated with subsequent fracture/fracture progression (p = 0.2986). However, patients with prior acetabular radiation therapy or surgery had increased fractures following treatment (p = 0.0380). CONCLUSION: Complete acetabular tumor ablation during CCC was not associated with superior pain relief compared to subtotal ablation but did result in improved fracture stabilization. Pre-treatment pathologic fractures were not associated with fracture progression, but new/progressive fractures were more frequent in patients with prior radiation therapy or surgery.

Comparison of a new recirculation thrombectomy catheter with other devices of the same type: in vitro and in vivo evaluations.

RATIONALE AND OBJECTIVES: To compare a new 7 Fr. Helix thrombectomy catheter with Amplatz thrombectomy devices (ATD) with respect to clot fragmentation efficiency, hemolytic potential, and risk for vascular trauma. MATERIALS AND METHODS: Particle size was evaluated following the maceration of 8-to-10-day-old clots, each weighing 6 +/- 0.01 g. The clots were macerated using devices of various sizes, including the 7-Fr. Helix thrombectomy catheter, the 7-Fr. over-the-wire (OTW), 8-Fr. ATD and the 6-Fr. ATD. The number of particles by weight was quantified. The 7-Fr. Helix and the 8-Fr. ATD were tested in the native iliac vein of six dogs without presence of clots. Blood samples were obtained before, during, and at 1, 3, 6, 24, and 48 hours after the procedure, to monitor the hemolytic effects. The treated iliac veins were examined histologically. RESULTS: Most of the clot was fragmented into particles <10 microm. The mean percentage by weight of the original clot that remained as particles larger than 10 microm was 1.59% in the 7-Fr. Helix group. This was significantly less than 3.10% with the 6-Fr. ATD, 2.57% with 7-Fr. OTW and 2.44% in the 8-Fr. ATD group (<0.01). In vivo results showed a higher plasma free hemoglobin (PFH) level starting 5 minutes after initiating the ATD activation, reaching its peak after completion of the activation, and declining afterward, with return to the baseline at 24 hours. The haptoglobin level tended to decline slightly at 10 minutes, reaching its lowest level at 24 hours, and starting to recover at 48 hours. A similar pattern of PFH and haptoglobin changes was found in both groups. There were no significant differences regarding hemolytic effect of the two tested devices. No significant changes of creatinine were observed for up to 48 hours after procedures. Focal microthrombosis was seen in two sites of two vessels treated with the 7-Fr. Helix and a focal injury of a venous valve was noted in the 8-Fr. ATD group. The media and internal elastic lamina (IEL) were intact in all cases. CONCLUSION: The newly designed 7-Fr. Helix is more effective in fragmentation in vitro clots than the 6 Fr. ATD, 7-Fr. OTW and the 8-Fr. ATD. The 7-Fr. Helix and the 8-Fr. ATD produced hemolytic effects, but they appeared to be tolerated by the animals. The in vivo results indicated that the 7-Fr. Helix appears to be as safe as the 8-Fr. ATD.

Intimal dehiscence in the abdominal aorta following balloon fenestration for type B dissection.

PURPOSE: To report a case of intimal dehiscence associated with endovascular intervention in patients with aortic dissection. CASE REPORT: A 65-year-old man presented with a type B dissection extending to the level of the common iliac arteries. Two Talent stent-grafts were placed in the descending thoracic aorta to close the entry point, but 2 lumens remained. Three days later, abdominal pain prompted another imaging session, which demonstrated a large cylindrical filling defect in the abdominal aorta ("tube-in-tube") assumed to be a partially or completely dehisced intima. Fenestration marginally improved flow to the visceral vessels, and the patient improved clinically. However, 4 days later, recurrent ischemic symptoms prompted surgery; a complete dehiscence of the aortic intima starting at the descending aorta extended to the distal abdominal aorta. The aorta was resected, but the patient died from disseminated intravascular coagulation. CONCLUSIONS: Intimal flap dehiscence associated with an endovascular procedure in the management of aortic dissection is an uncommon complication. Early detection and prompt surgical intervention of such a complication could save the patient's life. Endovascular procedures are unlikely to resolve the hemodynamic problem caused by a dehisced, distally migrated, collapsed intima.

Bifurcated endoprosthesis for treatment of aortoiliac occlusive lesions.

PURPOSE: To report our initial experience with a bifurcated endoprosthesis in the management of aortoiliac occlusive disease. METHODS: From May 2001 to February 2004, 112 patients were referred to our institution for the management of aortoiliac disease. Among these, 5 (6%) patients (3 men; mean age 57.8 years) with severe ischemia owing to TASC C or D iliac occlusions were selected for endovascular treatment with a bifurcated stent-graft. An Excluder stent-graft was placed after preliminary recanalization (thrombolysis and/or balloon dilation) the day before. The patients were followed clinically and ultrasonographically every 3 months during the first year and semiannually thereafter. RESULTS: Technical success was achieved in all patients. Endovascular aortoiliac bifurcation reconstruction restored iliac artery flow immediately in all cases. There were no procedure-related complications. The mean ankle-brachial index (ABI) was significantly improved, from 0.66+/-0.04 before the procedure to 0.94+/-0.06 immediately after the procedure (p<0.01). The aortoiliac reconstructions remained patent during the mean 17-month follow-up (range 3-36), and the ABIs were stable. There was no mortality or amputation required in this series. CONCLUSIONS: Endovascular placement of a bifurcated stent-graft appears to be technically feasible, effective, and safe in the management of aortoiliac occlusive disease.

Endovascular placement of an extraluminal femoropopliteal bypass graft in human cadavers.

PURPOSE: A method to create an extraluminal femoropopliteal bypass graft using endovascular techniques was evaluated in situ on cadaver extremities in an attempt to develop a minimally invasive alternative technique for the management of infrainguinal occlusive arterial disease. METHODS: The endovascular placement of an extraluminal femoropopliteal bypass graft was undertaken in 5 cadaver legs. Following percutaneous access to the popliteal artery (PA) or common femoral artery (CFA), a Rosch-Uchida needle was used to perforate the vascular wall, followed by the creation of an extraluminal tract using a looped wire and catheter. Once the desired level was reached the needle was again used to perforate the vascular wall of the proximal superficial femoral artery (SFA) or PA depending on the access used. Self-expanding expanded polytetrafluoroethylene (ePTFE) stent-grafts were then deployed to establish the extraluminal femoropopliteal bypass connecting the two arterial puncture sites. Following dilatation of the stent-graft, angiography was performed to assess the endoprostheses and to look for contrast leaks. RESULTS: Technical success was achieved in all 5 legs. Procedure time varied from 15 to 30 min. The angiographic studies performed immediately after completion of the bypass procedure showed patency of the grafts with no evidence of kinking or leakage in any of the cases. CONCLUSION: This study has proved that the endovascular placement of an extraluminal femoropopliteal bypass graft in human cadaver legs using endovascular techniques under fluoroscopic control is technically feasible.

An animal model of abdominal aortic aneurysm created with peritoneal patch: technique and initial results.

The purpose of this study was to develop an abdominal aortic aneurysm model that more closely resembles the morphology of human aneurysms with potential for further growth of the sac. An infrarenal abdominal aortic aneurysm (AAA) model was created with a double-layered peritoneal patch in 27 domestic swine. The patch, measuring in average from 6 to 12 cm in length and from 2 to 3 cm in width, was sutured to the edge of an aortotomy. Pre- and postsurgical digital subtraction aortograms (DSA) were obtained to document the appearance and dimensions of the aneurysm. All animals were followed with DSA for up to 5 months. Laparoscopic examination enhanced by the use of laparoscopic ultrasound was also carried out in 2 animals to assess the aneurysm at 30 and 60 days following surgery. Histological examination was performed on 4 animals. All the animals that underwent the surgical creation of the AAA survived the surgical procedure. Postsurgical DSA demonstrated the presence of the AAA in all animals, defined as more than 50% increase in diameter. The aneurysmal mean diameter increased from the baseline of 10.27 +/- 1.24 to 16.69 +/- 2.29 mm immediately after surgery, to 27.6 +/- 6.59 mm at 14 days, 32.45 +/- 8.76 mm at 30 days (p < 0.01), and subsequently decreased to 25.98 +/- 3.75 mm at 60 days. A total of 15 animals died of aneurysmal rupture that occurred more frequently in the long aneurysms (> or =6 cm in length) than the short aneurysms (<6 cm in length) during the first 2 weeks after surgery (p <0.05). No rupture occurred beyond 16 days after surgery. Four animals survived and underwent 60-day angiographic follow-up. Laparoscopic follow-up showed strong pulses, a reddish external appearance and undetectable suture lines on the aneurysmal wall. On pathology, the patches were well incorporated into the aortic wall, the luminal wall appeared almost completely endothelialized, and cellular and matrix proliferation were noted in the aneurysmal wall. A reproducible technique for the creation of an infrarenal AAA model was developed using a peritoneal patch in swine. The aneurysm model proved to have potential for further growth of the sac and a tendency to rupture. Because of the growth potential, this might be a better model than those with a noncompliant aneurysmal wall for the preclinical evaluation of stent-graft devices.