Blast injuries and heterotopic ossification.

Heterotopic ossification (HO) is perhaps the single most significant obstacle to independence, functional mobility, and return to duty for combat-injured veterans of Operation Enduring Freedom and Operation Iraqi Freedom. Recent research into the cause(s) of HO has been driven by a markedly higher prevalence seen in these wounded warriors than encountered in previous wars or following civilian trauma. To that end, research in both civilian and military laboratories continues to shed light onto the complex mechanisms behind HO formation, including systemic and wound specific factors, cell lineage, and neurogenic inflammation. Of particular interest, non-invasive in vivo testing using Raman spectroscopy may become a feasible modality for early detection, and a wound-specific model designed to detect the early gene transcript signatures associated with HO is being tested. Through a combined effort, the goals of early detection, risk stratification, and development of novel systemic and local prophylaxis may soon be attainable.

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.

Cost effectiveness and accuracy of renal scans in the management of patients undergoing renal transplantation.

Following renal allograft transplantation, renal scans are frequently performed to evaluate anatomical and functional causes for allograft dysfunction. In our retrospective study of 20 patients, renal scans were found to be more expensive compared to renal biopsies $68,688 vs $7,421, and, in only one patient was aggressive anti-rejection therapy instituted based solely on the renal scan results. The 95% confidence interval for the proportion of correct diagnosis by renal scan was 0.16 to 0.62.