Biomedical subjects

Paul J Dimuzio

Publications and source records attributed to Paul J Dimuzio.

4 recordsLinked to original sources

PubMed2005

Endovascular repair of symptomatic external carotid artery stenosis.

The treatment of external carotid artery stenosis has been described with a variety of operative interventions. We present a patient who presented with amaurosis fugax and a critical left external carotid artery stenosis with known left internal carotid artery occlusion. We treated this stenosis with angioplasty and stenting rather than endarterectomy. Our patient did well and had no complications from the procedure. Endovascular repair of symptomatic external carotid artery stenosis provides an alternative treatment method to conventional endarterectomy for patients with high surgical risk.

Aged↗

PubMed2004

Decellularized vein as a potential scaffold for vascular tissue engineering.

PURPOSE: Current strategies to create small-diameter vascular grafts involve seeding biocompatible, compliant scaffolds with autologous vascular cells. Our purpose was to study the composition and strength of decellularized vein to determine its potential as a vascular tissue-engineering scaffold. METHODS: Intact human greater saphenous vein specimens were decellularized by using sodium dodecyl sulfate (SDS). Residual cellular and extracellular matrix composition was studied with light and electron microscopy as well as immunohistochemistry. Burst and suture-holding strength was measured in vitro by insufflation and pull-through techniques. To assess initial handling and durability of decellularized vein in vivo, a canine model was developed wherein decellularized canine jugular veins were implanted as carotid interposition grafts in recipient animals. After two weeks of arterial perfusion, these grafts were studied with duplex imaging and histologic methods. RESULTS: Human saphenous vein decellularized by using SDS was devoid of endothelial cells and >94% of the cells resident within the vein wall. Collagen morphology appeared unchanged, and elastin staining decreased only slightly. Basement membrane collagen type IV remained intact. Compared with fresh vein, decellularized vein had similar in vitro burst (2480 +/- 460 mm Hg vs 2380 +/- 620 mm Hg; P >.05) and suture-holding (185 +/- 30 gm vs 178 +/- 66 gm; P >.05) strength. Decellularized canine vein functioned well in vivo without dilation, anastomotic complication, or rupture over 2 weeks of arterial perfusion. CONCLUSIONS: Vein rendered acellular with SDS has well-preserved extracellular matrix, basement membrane structure, and strength sufficient for vascular grafting. These properties suggest proof of concept for its use as a scaffold for further vascular tissue engineering. CLINICAL RELEVANCE: The following research examines the creation of a new small-diameter bypass graft. It is clinically relevant to patients who need distal arterial bypass, coronary artery bypass, or hemodialysis access, but who do not have adequate autologous vein for their surgeries. Future investigations will involve further tissue engineering of this vascular scaffold (eg, autologous endothelial seeding of its lumen) and testing the clinical usefulness of the completed graft.

Antigens, Surface↗

PubMed2004

Combination treatment of venous thoracic outlet syndrome: open surgical decompression and intraoperative angioplasty.

OBJECTIVE: Residual subclavian vein stenosis after thoracic outlet decompression in patients with venous thoracic outlet syndrome is often treated with postoperative percutaneous angioplasty (PTA). However, interval recurrent thrombosis before postoperative angioplasty is performed can be a vexing problem. Therefore we initiated a prospective trial at 2 referral institutions to evaluate the safety and efficacy of combined thoracic outlet decompression with intraoperative PTA performed in 1 stage. METHODS: Over 3 years 25 consecutive patients (16 women, 9 men; median age, 30 years) underwent treatment for venous thoracic outlet syndrome with a standard protocol at 2 institutions. Twenty-one patients (84%) underwent preoperative thrombolysis to treat axillosubclavian vein thrombosis. First-rib resection was performed through combined supraclavicular and infraclavicular incisions. Intraoperative venography and subclavian vein PTA were performed through a percutaneous basilic vein approach. Postoperative anticoagulation therapy was not used routinely. Venous duplex ultrasound scanning was performed postoperatively and at 1, 6, and 12 months. RESULTS: Intraoperative venography enabled identification of residual subclavian vein stenosis in 16 patients (64%), and all underwent intraoperative PTA with 100% technical success. Postoperative duplex scans documented subclavian vein patency in 23 patients (92%). Complications included subclavian vein recurrent thrombosis in 2 patients (8%), and both underwent percutaneous mechanical thrombectomy, with restoration of patency in 1 patient. One-year primary and secondary patency rates were 92% and 96%, respectively, at life-table analysis. CONCLUSIONS: Residual subclavian vein stenosis after operative thoracic outlet decompression is common in patients with venous thoracic outlet syndrome. Combination treatment with surgical thoracic outlet decompression and intraoperative PTA is a safe and effective means for identifying and treating residual subclavian vein stenosis. Moreover, intraoperative PTA may reduce the incidence of postoperative recurrent thrombosis and eliminate the need for venous stent placement or open venous repair.

Adult↗

PubMed2002

Aortic clamping during elective operations for infrarenal disease: The influence of clamping time on renal function.

OBJECTIVE: Aortic clamping proximal to the renal arteries is sometimes necessitated during infrarenal and juxtarenal aortic surgery and may be associated with an increased risk of renal ischemia and its consequences. The aim of the study was to estimate this risk and possibly identify a "safe" duration of renal ischemia. METHODS: Medical records were retrospectively reviewed for 60 consecutive patients (from 1987 to 1994) with abdominal aortic aneurysm (n = 43) and occlusive disease (n = 17) confined to the infrarenal or juxtarenal aorta who underwent infrarenal aortic reconstruction with temporary suprarenal clamping. The data obtained included risk factors, preoperative and postoperative serum creatinine level, blood urea nitrogen (BUN) value, proteinuria before surgery, and suprarenal clamping times. RESULTS: The mean age of the patients was 64.4 years (+/- 11.4 years), and 74% were men. Concomitant cardiac disease was present in 41% of the patients, and 9% had diabetes. The preoperative creatinine level was 1.21 mg/dL (+/- 0.54 mg/dL), and the BUN value was 16.6 mg/dL (+/- 7.8 mg/dL). During surgery, blood flow to the renal arteries was interrupted for 32.0 minutes (+/- 17 minutes). None of the surviving patients needed dialysis or had signs of acute renal failure after the operations, but transient azotemia (rise in creatinine level) occurred in 23% of the patients. Risk factors for this condition were high preoperative creatinine values and hypotension during surgery, but the main determinant was total renal ischemia time. Odds ratios for such transient renal dysfunction showed as much as a 10-fold risk when suprarenal aortic clamping was greater than 50 minutes as compared with 30 minutes or less. CONCLUSION: Postoperative renal function impairment is rare in this group of patients. If suprarenal clamp duration (renal ischemia time) is brief, patients with normal preoperative creatinine levels exhibit no increase or a marginal increase in BUN or creatinine levels after surgery. Accordingly, suprarenal aortic clamping less than 50 minutes in this patient group appears safe and well tolerated.

Adult↗