Search PubMed⌕ Search

Biomedical subjects

P S Fox

Publications and source records attributed to P S Fox.

At least 19 recordsLinked to original sources
PubMed1993

Recombinant tissue plasminogen activator for neonatal and pediatric vascular thrombolytic therapy.

Thrombotic vascular occlusion may complicate the clinical course of many neonatal and pediatric pathologic processes. Systemic thrombolytic therapy with heparin, urokinase, or streptokinase may not be appropriate in the critically ill neonate because these agents generate a diffuse coagulopathic state. Direct surgical intervention for repair may be precluded by the small size of the vessels involved. Recombinant tissue plasminogen activator (rTPA) induces only a minimal proteolytic state while inducing thrombolysis within the local environment of the clot. We report our experience with regional rTPA infusion in four critically ill patients with venous and arterial thrombotic disorders. there were two brachial artery occlusive lesions--a neonate with iatrogenic occlusion due to a misplaced intravenous catheter and a 2-year-old child with inadvertent arterial ligation during an attempted venous cutdown. Two venous lesions consisted of a full-term neonate with renal vein/inferior vena caval thrombosis and a 32-week infant with partial superior vena caval thrombosis due to a Broviac catheter. Systemic thrombolytic therapy was contraindicated in these patients because of underlying illnesses. Pretherapy vascular evaluation included Doppler examination and angiography. The rTPA infusion was continued until there was evidence of clot lysis by ultrasound, angiogram, or venogram. Infusion rate of rTPA was adjusted according to fibrinogen levels. All three neonates responded successfully to rTPA therapy. Two neonates required only bolus administration and one responded to combined bolus and continuous infusion therapy after 58 hours. rTPA failed to reverse brachial artery occlusion in the 2-year-old child with purpura fulminans.(ABSTRACT TRUNCATED AT 250 WORDS)

Brachial Artery↗
PubMed1977

High dose (bolus) intravenous methylprednisolone at the time of kidney homotransplantation.

A completely randomized double-blind study of bolus methylprednisolone versus dextrose in water, administered at the time of human kidney transplantation, has failed to demonstrate any beneficial effect of the steroid therapy. No differences were observed in the number of complete, irreversible graft rejections, the number of acute rejection episodes, or the number of postoperative steroid boluses administered in the treated or the control groups. Similarly, there were no differences in the mean serum creatinines at 30, 60, 90 days post-transplantation. There was a slight increase in mortality and incidence of complications in the group of patients receiving an intravenous bolus of methylprednisolone at the time of transplantation as compared to controls. The failure to demonstrate any beneficial effect and the slight increased mortality and morbidity associated with the bolus methylprednisolone dosage makes this therapy unjustifiable.

Clinical Trials as Topic↗
PubMed1977

Prevention of transplant renal artery stenosis.

Transplant renal artery stenosis occurred in 17 of 142 consecutive transplants (12 percent). All stenoses were in the renal artery distal to the anastomosis and two separate forms are recognized: angulation and segmental stenosis. Successful surgical correction in 12 of 17 patients relieved the hypertension and resulted in improved renal function. No patients receiving dipyridamole, a drug which inhibits platelet aggregation and intravascular fibrin deposition, developed segmental renal artery stenosis. No other factors could be identified which were important in either causing or preventing renal artery stenosis. Since intrarenal vascular changes are an integral aspect of rejection, the protection afforded by dipyridamole against segmental renal artery stenosis indicates that segmental stenosis is probably a manifestation of rejection.

Cadaver↗
PubMed1975

Homotransplant renal artery stenosis.

Transplant renal artery stenosis occurred in 12 of 101 consecutive kidney transplants. Stenoses were all located in the renal artery distal to the anastomosis. Two separate forms of stenosis are recognized: angulation and segmental. All transplant patients with severe diastolic hypertension, refractory to medical management, and an audible abdominal bruit should undergo angiography. Surgical correction of the stenosis was accomplished in nine of 12 patients with cure of their hypertension.

Angiography↗
PubMed1974

The influence of total gastrectomy on survival in malignant Zollinger-Ellison tumors.

The effect of total gastrectomy on the biologic behavior of malignant gastrinomas was studied from patient data collected in the ZE tumor registry. A total of 267 patients with documented metastatic tumor had definitive gastric operations. In the 137 patients who had total gastrectomy, survival was 75% at one year, 55% at five years and 42% at ten years. In the 130 patients who had lesser gastric operations, survival was 51% at one year, 27% at five years and 18% at ten years. Deaths from progressive tumor growth occurred in 17% of the patients at risk after total gastrectomy and 30% of the patients at risk after lesser gastric operations. A subgroup of 127 patients with documented liver metastasis had definitive gastric operations. Seventythree patients with liver metastasis had total gastrectomy with survival of 68% at one year, 42% at five years and 30% at ten years. Fifty-four patients with liver metastasis had lesser gastric operations with survival of 44% at one year, 7% at five years and none at ten years. Deaths from progressive tumor growth occurred in 25% of the patients at risk after total gastrectomy and 50% of the patients at risk after lesser gastric operations. Regression of metastatic ZE tumor was clearly documented in only four patients; all had total gastrectomy. Presumptive regression of primary tumor occurred in seven patients, five had total gastrectomy. The study clearly demonstrated that total gastrectomy was the procedure of choice for malignant ZE tumors, even in the presence of widespread metastasis. The results provided indirect evidence to support a gastric feedback effect which influences growth of gastrinomas; however, the results also show that total gastrectomy furnished neither predictable nor permanent protection from subsequent tumor growth and metastasis.

Adolescent↗
PubMedDate not supplied

Interventional radiologic placement of peripherally inserted central catheters.

PURPOSE: This study examines the difference in success between bedside insertions of peripherally inserted central catheters (PICCs) performed by clinicians and fluoroscopically assisted insertions by cardiovascular/interventional (CV/I) radiologists. PATIENTS AND MATERIALS: Four hundred four PICCs were inserted in 305 patients, with a mean age of 48 years (range, 8-78 years), who required intermediate and long-term central venous access. One hundred fifty patients underwent bedside insertion, and 155 patients underwent fluoroscopically assisted insertion. Dual- and single-lumen PICC devices were used depending on venous access needs. RESULTS: Central venous access with the PICC device was achieved in 111 (74%) of 150 bedside insertions and in 153 (98.7%) of 155 fluoroscopic insertions. Average PICC dwell time was 72.7 days (range, 2-307 days). Of the 305 patients, 244 (73.4%) completed planned therapy with a single catheter, 54 patients (17.7%) required two PICCs at the same site, 15 patients (4.9%) required three or more PICCs at the same site, and 12 patients (4.0%) required PICC replacement to a different site to complete therapy. Complications with bedside insertions included upper extremity thrombophlebitis (n = 4), entry site infection (n = 6), and PICC shear with migration (n = 2), while complications with fluoroscopic insertions included entry site infection (n = 2). CONCLUSION: Because of the far greater placement success achieved by CV/I radiologists, all PICCs are now inserted fluoroscopically. The devices complete favorably with surgically placed central catheters with regard to service interval, morbidity, and cost. Use of fluoroscopic techniques enables placement of these devices in virtually all patients, even those with seemingly no peripheral veins.

Adolescent↗
PubMedDate not supplied

Recombinant tissue plasminogen activator for the treatment of lower extremity peripheral vascular occlusive disease.

PURPOSE: Regional thrombolysis in the recanalization of peripheral vascular occlusive disease is an increasingly accepted therapeutic modality. Efficacy and complication rate are major issues in thrombolytic therapy. This prospective study was undertaken to determine if locally delivered recombinant tissue plasminogen activator (r-TPA) is safe and effective in clot lysis at non-weight-adjusted doses. PATIENTS AND METHODS: Twenty patients (undergoing 21 infusions) from two centers underwent fibrinolytic therapy with use of r-TPA, at a dose rate of 2 mg/h. The mean duration of arterial occlusion was 27.2 days (range, 1-117 days). Concomitant intravenous heparin anticoagulation was administered to all patients. A coaxial infusion delivery system was employed. Hematologic parameters and angiographic follow-up were evaluated at 4-hour intervals during thrombolytic infusion. The chosen maximum r-TPA dose of 40 mg could be extended at investigator discretion. RESULTS: Complete clot lysis was achieved in 18 of 21 (85.7%) infusions at a mean total dose of 38.9 mg (range, 8-84 mg). The mean infusion duration was 19.7 hours. In 16 of 19 (84.2%) infusions, in which the nadir fibrinogen level was recorded, it remained greater than 65% of baseline. Three of 21 (14.3%) infusions resulted in three major bleeding complications, one of which resulted in death. CONCLUSION: In this two-center trial, catheter-directed r-TPA infusion at 2 mg/h is effective for clot lysis. When combined with concomitant heparin administration, this treatment may result in an unacceptably high frequency of bleeding complications.

Adult↗