Biomedical subjects

John D Corson

Publications and source records attributed to John D Corson.

4 recordsLinked to original sources

PubMed2004

Balloon angioplasty as a treatment of failing infrainguinal autologous vein bypass grafts.

PURPOSE: The purpose of this study was to evaluate the role of balloon angioplasty in the treatment of failing infrainguinal vein bypass (IVB) grafts. METHODS: A retrospective chart review of patients undergoing revision of a failing IVB graft by vascular surgeons at a tertiary care center from 1990 to 2001 was performed. Failing bypass grafts were identified by routine duplex scan surveillance and physical examination. The criteria for endovascular intervention varied on the basis of surgeon preferences and time period; factors considered when choosing balloon angioplasty included significant comorbidities that precluded operative intervention, the lack of adequate conduit for surgical revision, or poor accessibility of the stenotic lesion. Data recorded included demographic patient data, type of IVB graft, patency status, further procedures performed, and all complications and mortalities. Cumulative primary and assisted patency rates were calculated by using Kaplan-Meier life-table analysis. RESULTS: A total of 45 balloon angioplasties were performed in 36 patients. There were 36 angioplasties of vein bypass grafts, and additional balloon angioplasties were performed on nine of these patients. Locations of IVB grafts included femoropopliteal (13 patients), femorodistal (13), and popliteal to distal (10). Initial success was achieved in 33 of 36 vein bypass grafts (91.7%). In these bypass grafts, the stenotic lesions were identified and treated at the proximal anastomosis (3 patients), mid-bypass graft (6 patients), and distal anastomosis (27 patients). Autogenous vein was used for all bypass grafts. Cumulative vein bypass graft (life-table analysis) primary patency rates (those free of occlusion or bypass graft threatening stenosis) were 74.2% at 6 months, 62.7% at 12 months, and 58.2% at 24 months. Repeat interventions included surgical thrombectomy with vein patch angioplasty or bypass graft revision, as well as repeat balloon angioplasty with or without thrombolysis. Cumulative assisted vein bypass graft patency rates (those free of occlusion or bypass graft threatening stenosis) were 87.0%, 83.2%, and 78.9% at 6, 12, and 24 months, respectively. Two patients (4%) developed thigh hematomas; no other procedure-related complications were noted, and there were no deaths in the perioperative period. CONCLUSION: Balloon angioplasty of failing infrainguinal vein bypass grafts can be successfully performed with a low rate of complications. Acceptable short-term patency can be achieved. This procedure should be considered as an initial option in failing IVB grafts.

Aged↗

PubMed2003

Endovascular treatment of celiac and mesenteric arteries stenoses: applications and results.

PURPOSE: To evaluate the safety and assess the role of endovascular therapy in a variety of conditions related to celiac and mesenteric vascular occlusive disease. Patients and methods Our retrospective study population included 25 consecutive patients (mean age, 66 years), in whom 28 procedures were performed on 26 stenosed or occluded mesenteric vessels (superior mesenteric artery [SMA] or celiac artery [CA]). Indications included chronic mesenteric ischemia (21 patients), including 2 patients who underwent stenting prior to a planned operative repair of a juxtamesenteric AAA. Three liver transplantation patients underwent stenting of an associated CA stenosis. One patient with a splenorenal bypass underwent stenting on an associated CA stenosis. The technical and clinical success rates and the incidence of complications were determined. Follow-up parameters included maintained patency on duplex sonography and sustained clinical benefit. The need for additional interventions was noted. RESULTS: All procedures but one were technically successful (96%). Major complications occurred in three patients (one transient contrast-induced nephrotoxicity and two pseudoaneurysms). Immediate clinical success was achieved in 22 patients (88%). The three clinical failures included two patients with an excellent angiographic outcome, but with single-vessel moderate severity disease. Survival table analysis of delayed clinical outcome showed primary and primary-assisted clinical benefits at 11 months of 85% and 91%, respectively. Primary and primary-assisted stent patencies, as assessed by duplex sonography and/or angiography, at 6 months were both 92%. Angiographically documented restenosis occurred in three patients. Restenosis in two patients with CA stents was due to extrinsic compression, and it was without symptoms in one patient and was treated satisfactorily by restenting in the other patient. Restenosis in one patient with an SMA stent was successfully treated by restenting. CONCLUSIONS: Our experience suggests a potential role for endovascular therapy of celiac and mesenteric arterial occlusive disease in a variety of clinical scenarios, with a low incidence of complications and a high technical success rate.

Adult↗

PubMed2002

High-resolution multiphase contrast-enhanced three-dimensional MR angiography compared with two-dimensional time-of-flight MR angiography for the identification of pedal vessels.

PURPOSE: The authors prospectively evaluated optimized multiphase high-resolution (HR) Gadolinium (Gd)-enhanced three-dimensional (3D) magnetic resonance (MR) angiography and standard two-dimensional (2D) time-of-flight (TOF) MR angiography for their ability to delineate distal calf and pedal vessels. MATERIALS AND METHODS: Twelve patients (20 limbs) with limb-threatening peripheral arterial occlusive disease underwent HR Gd-enhanced and 2D TOF MR angiography to identify targets for distal bypass. Imaging of the region of the ankle and foot was performed on a 1.5 T system with a head coil. A standard 2D TOF MR angiography sequence was performed first. The HR Gd-enhanced MR angiography sequence was then performed after injection of 0.01-0.2 mmol/kg of gadodiamide, allowing the acquisition of multiple consecutive coronal partitions, each in 18-25 seconds. Two experienced angiographers independently analyzed both studies. Comparison with intraoperative conventional angiography was available in 10 limbs. RESULTS: HR Gd-enhanced MR angiography allowed significantly faster imaging time (P <.0001) and larger coverage area (P <.0001) than 2D TOF MR angiography. All segments seen on 2D TOF MR angiography were visualized on HR Gd MR angiography, and significantly more suitable targets were seen well on HR Gd-enhanced MR angiography than on 2D TOF MR angiography (mean targets per limb: 3.9 +/- 1.9 vs 2.6 +/- 1.5, respectively; P =.02). In addition, HR Gd-enhanced MR angiography allowed better visualization of the arcuate pedal branch than 2D TOF MR angiography (P <.0001). Excellent correlation was demonstrated between HR Gd-enhanced MR angiography and intraoperative angiography in 29 segments (binary similarity coefficient, 0.90). A significantly higher percentage of artifacts adversely affected image interpretation with 2D TOF MR angiography than with HR Gd-enhanced MR angiography (14 limbs vs five limbs, P <.001). Artifacts on HR Gd-enhanced MR angiography included suboptimal mask in two limbs, venous contamination in one patient (two limbs), and motion artifact in one limb, although the studies remained diagnostic in all cases. CONCLUSION: HR Gd-enhanced MR angiography identified more distal target vessels with greater confidence than 2D TOF MR angiography. Optimized HR Gd-enhanced MR angiography may replace 2D TOF MR angiography as the gold standard examination for evaluation of distal runoff.

Ankle↗

PubMedDate not supplied

Hemorrhagic complications during long-term postoperative warfarin administration in patients undergoing lower extremity arterial bypass surgery.

Lower extremity bypass procedures restore function and prevent amputation in many patients with severe peripheral arterial occlusive disease. The regular postoperative use of aspirin offers the dual benefit of extending bypass patency and patient survival. Previous trials of adjunctive oral anticoagulant therapy with warfarin have infrequently combined warfarin with aspirin. We hypothesized that the addition of oral anticoagulant therapy would further enhance the benefits of aspirin but may increase the risk of clinically important bleeding. Eligible patients (N = 831) scheduled for elective lower extremity arterial bypass surgery were randomized to receive either warfarin plus aspirin (WA) (n = 418) or aspirin alone (n = 413). At monthly intervals, the warfarin dose was adjusted to a target international normalized ratio (INR) of 1.4 to 2.8; both groups received aspirin (325 mg/d). The end point of major hemorrhagic events, defined as intracranial hemorrhage or bleeding that required intervention, is reported, and INR values and compliance with warfarin therapy are presented. Major hemorrhagic events occurred more frequently in the WA group (35 in the WA group vs 15 in the aspirin group; p = .02) during a mean follow-up of 38 months. In the WA group, an intracranial hemorrhage occurred in six patients (two had an INR > 3.0), of whom four died; one subdural hemorrhage occurred in the aspirin group. Transfusions and interventions for bleeding were more frequent in the WA group, as were minor bleeding events. Of the 8,946 INR determinations, 58% were in the target range, whereas a higher value occurred in 10% and a lower value in 32%. Compliance with warfarin was maintained in 65% of the patients after the first year of observation. In patients with elective lower extremity bypass procedures, the postoperative adjunctive use of warfarin with aspirin increased the risk of major hemorrhagic events. Most of these events occurred when the INR was in the target range.

Anticoagulants↗