New Graft for Low Friction Tunneling in Vascular Access Surgery

Purpose

Prosthetic accesses of the upper extremity have been in use for more than 25 years. Many different conduits have been employed; investigators have continually searched for a graft with superior properties.

Methods

We describe a prospective randomized study comparing the new Slider Graft (Atrium) with the Hybrid PTFE Graft (Atrium); the latter has been used for a number of years. The Slider Graft is also made of PTFE. For this study, both grafts were 6 mm in diameter and 40 cm in length. The Slider Graft has a low friction polyethylene sheath over its entire length. This sheath expedites the passage of the graft through the tunnel. At one end, the graft and the polyethylene sheath are attached to a metal tip. This tip has male threads, which may be inserted firmly into a Kelly Wyck, Atrium, or any standard non-sheath tunneling system. This alleviates graft separation, turning, and slipping during tunneling. The primary objective of this trial was to determine the safety and efficacy of the Slider Graft as compared to the Hybrid Graft in vascular access surgery. The secondary objective was to evaluate how tunneling effects graft performance. We randomized 60 subjects for this study with two equal arms. During surgery we measured various parameters including ease of tunneling, tunnel bleeding, anastomotic bleeding, graft sweating, and immediate patency. To assess arm edema we measured circumference 7.5 cm and 20 cm above the wrist, prior to surgery and in follow-up visits at 1 week, 1 month, and 3 months. Primary patency was also assessed at these visits and at 6, 9, and 12 months.

Results

Our results show tunneling with the Slider Graft is easier to accomplish (p = 0.0001) with reduced tunnel bleeding (p = 0.0047) and anastomotic bleeding (p = 0.042). Further, the Slider Graft virtually eliminated the complication of graft sweating and seroma development (p = 0.0005). This may be due to reduced stretching and graft wetting during insertion. At 180 days the Slider Graft demonstrated improved primary patency, which was statistically significant (p = 0.047). At 360 and 720 days the Slider Graft continued to demonstrate a trend toward improved primary patency (p = 0.160).

Conclusions

This study suggests the Slider Graft has significant advantages when compared to the Hybrid Graft and highlights the importance of tunneling in creating prosthetic accesses.

Percutaneous transluminal angioplasty adjunct to thrombolysis for acute middle cerebral artery rethrombosis

PURPOSE

To report three patients, each of whom had acute rethrombosis of a reopened middle cerebral artery after urokinase treatment for proximal stenosis (percutaneous transluminal angioplasty of the stenosis was performed adjunctive to the thrombolytic treatment to preserve the success of the thrombolysis), and a fourth patient who had percutaneous transluminal angioplasty right after the completion of thrombolysis and had no rethrombosis despite a partial dilatation of the severe stenosis.

METHODS

Thrombolytic treatment was carried out by a coaxial technique with a Tracker 18 catheter through a 5-F angiographic catheter; 80,000 U in 5 mL of urokinase were intermittently injected every 15 minutes after an initial dose of 250,000 U. All patients were given 3000 U of heparin with a booster dose of 1000 U every hour. Angioplasty was performed with a Stealth catheter balloon, 2 to 3 mm x 1.5 cm.

RESULTS

Three patients recovered without hemorrhage after percutaneous transluminal angioplasty and thrombolytic treatment. Percutaneous transluminal angioplasty was unsuccessful in one patient because of the inability to pass a 2-mm Stealth balloon catheter, and the result was a second rethrombosis. This patient had a poor recovery.

CONCLUSION

Acute thrombosis of the middle cerebral artery may be associated with severe proximal stenosis. Rethrombosis may occur even after complete thrombolysis. Percutaneous transluminal angioplasty may be safely performed to prevent rethrombosis.

Acute thrombosis of the intracranial dural sinus: direct thrombolytic treatment

Acute intracranial dural sinus thrombosis may have severe morbidity or fatal complications without appropriate treatment. Direct dural sinus venography can be performed safely with a soft Tracker catheter to document the fresh thrombus as an adjunct to CT or MR. We are reporting our experience with successful direct urokinase thrombolytic therapy in three cases of superior sagittal sinus and two cases of transverse and sigmoid sinus thrombosis. All five patients have recovered completely without any residual clinical deficit.