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Biomedical subjects

R A McCready

Publications and source records attributed to R A McCready.

At least 19 recordsLinked to original sources
PubMed1996

Ultrasound imaging of the radial artery following its use for cardiac catheterization.

Our experience suggests transradial arterial access with 5Fr catheters can be used for cardiac angiography with a low incidence of clinical complications, and supports the findings of previous investigators. Subclinical complications at the catheterization site were infrequent in this study (1 patient with asymptomatic radial artery occlusion). The presence of a palpable radial pulse may not be a reliable estimate of artery patency as evidenced by our patient with a palpable pulse due to retrograde flow. The theoretical advantage of the procedure is derived from the dual vascular supply to the hand. Radial artery occlusion, while uncommon, results in no ischemic sequelae in the setting of a patent ulnar artery.

Aged↗
PubMed1993

Ruptured abdominal aortic aneurysms in a private hospital: a decade's experience (1980-1989).

Despite refinements in elective resection of abdominal aortic aneurysms, morbidity and mortality rates for ruptured abdominal aortic aneurysms (RAAAs) remain high. Between January 1, 1980 and December 31, 1989, we treated 208 patients with RAAAs whose mean age was 70 years. The overall mortality rate was 49.5%. Logistic regression analysis showed that three factors correlated with predicted patient survival. Patients < 70 years old had a survival rate of 65.7% compared with a survival rate of 37.4% in patients > 70 years old (p < 0.001). Among "stable" patients (preoperative blood pressure consistently > 90 mm Hg), 88.9% survived compared with 40.9% of "unstable" patients (blood pressure < 90 mm Hg) (p < 0.001). Of the patients with free intraperitoneal rupture, 38.3% survived compared with a survival rate of 79.6% of patients with rupture confined to the retroperitoneum (p < 0.001). Despite a high overall mortality rate in patients with RAAAs, surgical intervention remains the only hope for survival. We continue to advocate an aggressive surgical approach in this group of patients.

Aged↗
PubMed1993

Angioscope-assisted endovascular occlusion of venous tributaries: preclinical studies.

The feasibility of angioscope-assisted occlusion of venous tributaries from within a vein using a steerable 'shaped-memory' nickel-titanium (nitinol) alloy catheter and occlusion coils was evaluated. An initial series of tests was designed to establish the necessary pressure (275 p.s.i., 1897.5 kPa), time (1.5 s) and volume (2.5 ml normal saline) requirements for hydraulic delivery of platinum occlusion coils from the nitinol catheter through a 3-Fr tracking catheter. In a second series, 25 side branches of the saphenous vein in 11 amputated limbs were visualized angioscopically and cannulated with the nitinol catheter under angioscopic and fluoroscopic surveillance to determine whether the catheter tip could be positioned and coils deployed. In a third series of studies, ten canine femoral vein tributaries were successfully cannulated with an 8-Fr nitinol catheter and 19 occlusion coils delivered under angioscopic surveillance. Fluoroscopy verified coil placement and all embolized venous tributaries were thrombosed. An ideal approach for femoropopliteal in situ saphenous vein bypass would allow the surgeon to divide saphenous vein valves while occluding venous side branches from within the saphenous vein. These initial studies demonstrate that the nitinol catheter can occlude venous tributaries from within a vein by coil embolization. Further development of this technique for clinical investigation is warranted.

Angioscopes↗
PubMed1993

One-stage segmental resection of extensive thoracoabdominal aneurysms with left-sided heart bypass.

PURPOSE: The purpose of this study is to describe a technique for resection of extensive thoracoabdominal aneurysms, which the authors believe will lower morbidity and mortality rates. METHODS: In an effort to minimize the risk of spinal cord ischemia, we have used a combination of sided heart bypass (left atrium to left femoral artery) with local cooling of the intercostal and visceral arteries and segmental resection of the aneurysm. Segmental resection of the aneurysm allows perfusion of the spinal cord and abdominal viscera as the proximal anastomosis is completed and as each pair of intercostal arteries is reimplanted. An attempt is made to reimplant all pairs of intercostal arteries from T8 to L2. Before the intercostal or visceral arteries are reimplanted, that segment of aorta is cooled with cold crystalloid solution. Thus no segment of the aorta is exposed to warm ischemia for more than 30 minutes. Left-sided heart bypass allows the patient's temperature to be maintained between 35 degrees C and 37 degrees C. RESULTS: We have used this technique in 23 patients with types I and II (Crawford's classification) thoracoabdominal aneurysms. Seven patients (30%) had dissections or rupture associated with their aneurysms and underwent emergency operation. One of these seven patients became paraplegic after operation, for a 4.3% incidence of paraplegia. One patient died of multiple organ failure after operation. No patient had kidney failure requiring dialysis. CONCLUSIONS: We believe that our technique allows the operation to be performed in a deliberate manner with a low incidence of paraplegia and kidney failure.

Adult↗
PubMed1992

Delayed postoperative bleeding from polytetrafluoroethylene carotid artery patches.

Patch angioplasty of the internal carotid artery after endarterectomy has been advocated as a means of decreasing early postoperative carotid artery thrombosis, as well as reducing the incidence of recurrent carotid artery stenosis. Noninfectious rupture of saphenous vein patches in the early postoperative period has been reported by several authors, leading others to advocate the use of prosthetic patches. This report describes three patients in whom delayed bleeding through needle holes along the suture lines in polytetrafluoroethylene cardiovascular patches occurred between 1.5 and 4 days after operation. All patients required reexploration to control bleeding, and acute respiratory distress from tracheal compression developed in one patient. Although delayed bleeding through needle holes in polytetrafluoroethylene cardiovascular patches appears to be rare, a word of caution may be in order before advocating routine patching of the carotid artery with this particular type of patch.

Aged↗
PubMed1991

Septic complications after cardiac catheterization and percutaneous transluminal coronary angioplasty.

Septic complications after cardiac catheterization and percutaneous transluminal coronary artery angioplasty are distinctly uncommon. However, we have recently treated nine patients with sepsis and life-threatening complications after cardiac catheterization alone or after catheterization and subsequent percutaneous transluminal coronary angioplasty. The common denominator in all patients was either repeat puncturing of the ipsilateral femoral artery or leaving the femoral artery sheath in for 1 to 5 days after the procedure. Two patients died as a direct result of their septic complications. One death occurred in a patient in whom bacterial endocarditis with congestive heart failure developed, and the other patient had a large retroperitoneal hematoma that became secondarily infected. Infected aneurysms that were successfully treated developed in three patients. Our study suggests that colonization of the needle tract by skin flora predisposes to septic complications if repeat arterial punctures are required or if a femoral artery sheath is left in place for more than 24 hours. Patients in whom sepsis develops after these procedures should be initially treated with antibiotics effective against gram-positive organisms. CT scanning or angiography should be considered for patients with persistent sepsis, septic emboli, and abdominal or flank pain. Infected aneurysms require resection or ligation because of the propensity of these aneurysms to rupture.

Aged↗
PubMed1990

Combined coronary artery bypass grafting and bilateral renal revascularization for unstable angina and impeding renal failure.

The purpose of our article is to describe a patient with severe hypertension and moderate renal insufficiency, unstable angina, and a 6 cm abdominal aortic aneurysm. A previous aortogram had demonstrated severe bilateral renal artery stenoses. Cardiac catheterization demonstrated severe coronary disease. After cardiac catheterization acute renal failure and pulmonary edema requiring dialysis developed in the patient. In addition, evidence of impending myocardial necrosis developed. Because of the critical nature of the myocardial and renal ischemia it was necessary to perform combined myocardial and renal revascularization rather than staged procedures. At the time of coronary artery bypass grafting, a vein graft was anastomosed to the right coronary artery vein graft and tunneled through the diaphragm into the abdomen to revascularize both renal arteries. After surgery renal function gradually improved, and no further dialysis was required. The abdominal aortic aneurysm was repaired at a subsequent operation. At 2-year follow-up all grafts remained patent. The serum creatinine is 1.2 mg/dl. Although most patients with combined coronary artery disease and renal artery disease can be treated with staged operations, our procedure may be of value in patients in whom staged procedure are not feasible and in whom the infrarenal aorta is severely diseased or aneurysmal.

Acute Kidney Injury↗
PubMed1989

What is the role of carotid arterial resection in the management of advanced cervical cancer?

From 1977 through 1988, 16 patients underwent carotid artery resection and reconstruction or simple ligation in the treatment of advanced cervical carcinomas. Three patients underwent carotid artery ligation, with postoperative transient ischemic attacks, which resolved, in one patient. In the remaining 13 patients, interposition saphenous vein grafts were used to reconstruct the resected carotid arteries. In one of these 13 patients, the previously unresected carotid artery ruptured and was treated by carotid artery resection with interposition vein grafting and coverage by a myocutaneous flap. There were two immediate postoperative strokes, with excellent neurologic recovery in one, and one late postoperative stroke (6 months). There was one postoperative death. Adjunctive intraoperative irradiation (1500 to 2000 rad) was employed in 15 patients to decrease the risk of recurrent disease. Since 1982, pectoralis major muscle flaps have been constructed in all patients to cover the vein grafts, with no subsequent carotid artery blowouts. Seven patients are free of cancer more than 1 year after surgery. In conclusion, carotid artery resection for the treatment of advanced cervical carcinomas may be accomplished with acceptable morbidity and mortality rates in carefully selected cases. Coverage of the vein graft by a myocutaneous flap appears to protect against carotid artery blowout. Intraoperative irradiation appears to decrease significantly the local recurrence rate of these aggressive tumors.

Aged↗
PubMed1988

Upper-extremity vascular injuries.

Although upper-extremity injuries alone are usually not life-threatening, they can produce significant immediate or long-term morbidity, especially if there is an associated nerve injury. The diagnosis of an arterial injury may be readily apparent, but the excellent upper-extremity collateral circulation may create palpable distal pulses despite a significant proximal arterial injury. Therefore, a high index of suspicion and the liberal use of arteriography are necessary to avoid missing these injuries. Compression of the brachial plexus by a hematoma can produce a serious neurologic deficit. Prompt evacuation of the hematoma may significantly reduce the deficit, another fact that supports an aggressive surgical approach in these patients. The long-term results of upper-extremity vascular injuries are usually determined by the extent of any associated nerve injuries.

Arm↗
PubMed1988

Massive upper extremity edema following vascular access surgery.

We recently treated three patients with chronic renal failure who required subclavian vein cannulation with Uldall catheters following thrombosis of their arteriovenous fistulae. New arteriovenous fistulae were created in each patient following removal of the Uldall catheters. The patients were seen subsequently with massive, painful edema in the ipsilateral upper extremities from one to 10 weeks following creation of the arteriovenous fistulae. Radiographic studies documented stenosis or occlusion of the ipsilateral proximal subclavian vein. The arteriovenous fistula was ultimately ligated in each patient, which promptly resolved the pain and edema. Because subclavian vein thrombosis following temporary hemodialysis through an indwelling catheter is frequently asymptomatic until an arteriovenous fistula is constructed, venography should be considered in patients requiring upper extremity vascular access procedures. Demonstration of subclavian vein stenosis or occlusion would either preclude use of the upper extremity for an arteriovenous fistula or would require a concomitant procedure to relieve the venous obstruction.

Adult↗
PubMed1987

Renal revascularization in patients with a single functioning ischemic kidney.

From 1965 to 1985, 19 patients with a single, ischemic kidney underwent renal revascularization. Thirteen patients had a single kidney and six had a single functioning kidney. The cause of the renal artery lesions was atherosclerosis in 17 patients and fibromuscular dysplasia in two. All but one were hypertensive with a mean diastolic blood pressure of 119 mm Hg and they were taking an average of 2.6 antihypertensive medications. Most had diminished renal function with a mean serum creatinine value of 3.7 mg/dl (range 0.8 to 9.0 mg/dl) and a mean creatinine clearance of 38 ml/min (range 8 to 75 ml/min). Three patients required preoperative hemodialysis. The first two patients treated died postoperatively, but no deaths have occurred since 1970. Follow-up among the survivors averaged 32.9 months. The mean serum creatinine value decreased significantly to 2.2 mg/dl postoperatively (p less than 0.04); the mean diastolic pressure decreased significantly to 86 mm Hg (p less than 0.001). One patient was normotensive preoperatively. Of the 16 patients surviving operation, 14 had improvement of their hypertension, one was cured, and only one did not benefit. No patient's hypertension was worse. The mean number of postoperative antihypertensive medications decreased significantly to 1.5 medications per patient (p less than 0.02). These data suggest that an aggressive surgical approach is warranted in patients with a single ischemic kidney in need of revascularization because of the gratifying response both in control of hypertension and improvement of renal function.

Adult↗
PubMed1987

Long-term results with autogenous tissue repair of traumatic extremity vascular injuries.

With extensive vascular injuries in which a vascular conduit is required, there is controversy as to whether an autogenous or prosthetic graft is preferable. The authors reviewed their experience with 91 extremity arterial injuries in which autogenous tissue was used to repair vascular injuries of the extremities. Twenty-two patients also had concomitant repair of associated venous injuries with autogenous vein grafts. Ten patients required amputations, despite patent grafts in five patients, because of severe muscle necrosis. Two patients had thrombosis of their vein grafts develop in the early postoperative period but did not require amputation. The authors identified only one late vein graft failure in a patient in whom an infected pseudoaneurysm developed. Three patients with extensive soft tissue injuries had infection develop in vein grafts, with subsequent massive bleeding that ultimately required arterial ligation. Among the 22 patients with repair of their venous injuries, occlusion of popliteal vein repairs was documented in two patients and suspected in three others. The remainder of patients had satisfactory results. The excellent results obtained in the vast majority of the authors' patients with extremity vascular injuries reinforces their preference for using autogenous tissue whenever a vascular conduit is required. Exceptions include patients with extensive soft tissue loss precluding adequate graft coverage, the repair of large vessels, and life-threatening emergencies when there is insufficient time to harvest and prepare a vein.

Adolescent↗
PubMed1986

The intraoperative measure of runoff resistance in the canine hindlimb.

Long-term survival of femoro-popliteal grafts has been predicted on both graft function and distal vascular bed resistance. The purpose of this study was to demonstrate peripheral resistance as a function of the inherent elasticity (distensibility) of the distal vascular bed. The use of saline perfusate and maintenance of physiologic pressure will supplant such other factors as fluid viscosity, vasomotor tone, blood pressure, and tube dimensions. Our model consisted of Javid shunt insertion in the femoral artery of 13 female dogs distal to an occlusive tie. Saline was perfused in incremental fashion every 30 sec over a 5-min period; femoral pressure measurements were taken at each flow rate (Q) (cc/min). Results show that mean femoral pressure (MFP) varies with Q less than 125 (P less than 0.005) and Q greater than 200 (P less than 0.001). Furthermore, mean resistance (MR) declined precipitously with Q greater than 125 cc/min but at higher Q the MR plateaued (P less than 0.0001). We interpret these results to indicate that at Q less than 125 vasomotor tone is the predominant factor in MR and that saline perfusion abrogated this factor at 125 greater than Q less than 200. At Q greater than 200, MR declined only slightly and, therefore, MFP varied directly with Q indicating that vessel elasticity is the predominant feature of MR after vasomotor tone ablation and that pressure varies directly with flow in a distensible system. Pressure-flow graphs could be obtained prior to femoro-popliteal reconstruction via this quick, simple technique and rapid rises in pressure should indicate poor distal runoff.

Animals↗
PubMed1986

Subclavian-axillary vascular trauma.

Traumatic vascular injuries to the subclavian and axillary vessels are often associated with permanent neurologic impairment either by direct injury to the brachial plexus or by compression from an expanding hematoma. Prompt decompression of the plexus by evacuation of the hematoma may avoid permanent neurologic damage and decrease the morbidity of these injuries. We reviewed our experience with these injuries with particular reference to the effect of early decompression of the brachial plexus. From 1963 to 1984 we treated 40 patients. The causes of the injuries were penetrating trauma in 85% and blunt trauma in 15%. The results of arterial repair were excellent with only two failed repairs; neither resulted in severe ischemia. Two patients were suspected of having thrombosed venous repairs. Among the 12 patients with direct injury to the brachial plexus (partial or complete transection), only six had subsequent improvement of their neurologic dysfunction. In contrast, six of seven patients in whom there was only compression of the plexus by hematoma but no direct injury, had neurologic improvement following evacuation of the hematoma. This finding suggests that prompt decompression of the brachial plexus following these injuries may reduce the amount of neurologic impairment and reduce the morbidity of these injuries.

Adolescent↗
PubMed1986

Sciatic artery aneurysms: report of three cases and review of the literature.

Sciatic artery aneurysms (SAAs) develop in a persistent sciatic artery, which is a congenital anomalous continuation of the internal iliac artery and may be the major blood supply to the lower extremity. SAAs may appear clinically with rupture, thrombosis, distal embolization, or compression of the sciatic nerve. We have reviewed our three cases and the literature to delineate those factors that permit correct preoperative diagnosis and appropriate surgical intervention. Our three patients (aged 54 to 82 years) appeared with severe ischemia that resulted in above-knee amputations. The literature reveals 21 patients ranging in age from 35 to 84 years (58% were women). Twenty of those patients had operations, one of which resulted in death, and five in above-knee amputations. Unexplained sciatic or buttock pain, or a palpable "pulsating" buttock mass, suggests an SAA. The diagnosis is confirmed by angiography. The recommended treatment is femoropopliteal bypass grafting followed by ligature or percutaneous endovascular thrombosis of the aneurysm. Early diagnosis and correct surgical therapy are the keys to successful management of SAA.

Aged↗
PubMed1985

Failure of antiplatelet therapy with ibuprofen (Motrin) to prevent neointimal fibrous hyperplasia.

To evaluate the effect of ibuprofen (Motrin) on the development of neointimal fibrous hyperplasia (NFH), 4 cm segments of expanded polytetrafluoroethylene (ePTFE) grafts with an internal diameter of 4 mm were implanted in the femoral arteries of 28 dogs. Three dogs served as controls and these grafts were removed at 7 to 14 days. The remaining 25 dogs were medicated with either intravenous (IV) or oral (PO) ibuprofen. The medicated dogs were grouped according to whether the ibuprofen was administered prior to or after graft implantation. The orally medicated dogs were also grouped according to whether the grafts were removed from 30 to 60 days after graft implantation. The grafts were analyzed for the amount of anastomotic initimal hyperplasia, pannus extension, thrombus deposition, and patency. Analysis of the data demonstrated no statistically significant differences among any of the treatment groups or the control group for the variables analyzed. We conclude that ibuprofen neither prevents nor retards the development of NFH. There was a trend toward less thrombus deposition in the animals that received oral ibuprofen preoperatively. There was also a trend toward higher patency in the animals that received ibuprofen prior to graft implantation, which most likely resulted from decreased thrombus and fibrin deposition.

Animals↗
PubMed1985

A technique for intraoperative arteriography following carotid endarterectomy.

This technique provides a simple and reliable means of obtaining an operative arteriogram after carotid endarterectomy. Detection of unsuspected abnormalities before the wound is closed allows the surgeon to correct any abnormalities immediately with hopes of decreasing the incidence of postoperative neurological deficits.

Carotid Arteries↗