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Biomedical subjects

W J Fry

Publications and source records attributed to W J Fry.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effect of nitroglycerin and aortic occlusion on myocardial blood flow.

To better characterize the cardiac and peripheral effects of nitroglycerin during aortic occlusion, we measured myocardial blood flow in 43 normal and pentobarbital (PB)-depressed dogs (groups I to VII). PB was continuously infused in groups IV to VII to maintain reduced cardiac output and contractility. In groups VI and VII nitroglycerin was administered at 2 micrograms/kg/min. Sequential injections of radioactive microspheres (10 micrometers) and hemodynamic measurements were performed during 2-hour occlusions of the infrarenal aorta. The hearts were divided into endocardium, midmyocardium, and epicardium; total and regional blood flows and the ratio of endocardial to epicardial blood flow (endo/epi) were calculated. The results (mean +/- SEM) were subjected to analysis of variance. Normal dogs that underwent aortic occlusion had predictable increases in peripheral vascular resistance. Coronary vascular resistance fell (P less than 0.05) and endo/epi ratios were maintained above 1. Following PB administration, the myocardial blood flow uniformly fell (1.08 +/- 0.34 to 0.55 +/-0.09 ml/min/gm, P less than 0.001), and the animals not treated with nitroglycerin demonstrated decreased endo/epi ratios (1.11 +/- 0-.07 to 0.83 +/- 0.08, P less than 0.001). Although nitroglycerin did not prevent decreases in total myocardial blood flow, endo/epi ratios were maintained above 1 in treated animals (group VI, 1.04 +/- 0.08; group VII, 1.18 +/- 0.17). Furthermore, the increases in left ventricular end diastolic pressure in the untreated animals were significantly greater than those in animals receiving nitroglycerin (P less than 0.01). Despite severe cardiac depression, nitroglycerin maintained normal transmural distribution favoring the endocardium. Since coronary and peripheral vascular resistances were not altered, this benefit most probably reflects decreased ventricular wall tension secondary to preload reduction.

Anesthesia, Inhalation↗
PubMed1981

Vertebral artery trauma: acute recognition and treatment.

Vertebral artery injury is uncommon and may be initially unrecognized. Sequelae of vertebral artery injury include arteriovenous fistulae and pseudoaneurysms that may appear months after injury. The incidence of the sequelae is unknown. Cervical angiography used in the routine evaluation of a patient with penetrating neck trauma readily demonstrates vertebral artery injuries. This series of 13 cases demonstrates the low morbidity associated with the treatment of isolated vertebral artery injuries. A technique for proximal and distal ligation of the vertebral artery is presented. Its use is recommended in the treatment of any patient with vertebral artery injury who has a normal contralateral vertebral artery and no demonstrable extracranial branches from the vertebral artery to the spinal cord.

Humans↗
PubMed1981

Pediatric renal artery occlusive disease and renovascular hypertension. Etiology, diagnosis, and operative treatment.

Forty pediatric patients (16 girls and 24 boys) 22 months to 17 years old underwent operation for renovascular hypertension. Ostial stenoses were present in 20 children; midrenal lesions were present in eight; and isolated segmental disease was present in 12 patients and was combined with main renal artery stenoses in three patients. Neurofibromatosis affected ten patients, including three having abdominal aortic anomalies. Abdominal aortic coarctation affected five other children. Hypertensive urograms were abnormal only 27% of the time. Renin assays were helpful in identifying functionally important renal ischemia. Fifty-one primary surgical procedures were undertaken, including one simultaneous and nine staged operations for bilateral disease. There were two primary nephrectomies. Six patients underwent later secondary operations. Thirty-four patient (85%) were cured of hypertension, the conditions of five (12.5%) were improved, and one (2.5%) was classified a therapeutic failure. Carefully performed arterial reconstructive surgery will benefit most pediatric patients with renovascular hypertension.

Adolescent↗
PubMed1981

Acute and chronic traumatic arteriovenous fistulae in civilians. Epidemiology and treatment.

Traumatic arteriovenous fistula (AVF) is an uncommon form of vascular disruption. We reviewed 70 AVFs in 69 patients. Nearly one in ten acute arterial injuries is an AVF. Only half of these lesions, however, are clinically demonstrable. Iatrogenic lesions were present in 13% of patients. Eighty-one percent of lesions were treated surgically. Extracranial-intracranial (EC-IC) vascular bypass was used in over one third of head and high neck AVFs. Embolization was used as an adjunct to surgery in about one fourth of patients, and fewer than one in ten were treated with embolization alone. Since half of these lesions are not clinically detectable, liberal use of angiography is necessary for all traumatic wounds in proximity to a major vascular structure. Embolization was useful both as a primary treatment of AVF and as an adjunct to surgery; EC-IC bypass facilitates treatment of inaccessible fistulae in the head and neck.

Adolescent↗
PubMed1980

Acute and subacute pancreatitis. Role of surgery and endoscopic retrograde cholangiopancreatography.

Six of seven patients with acute pancreatitis who were intractable to prolonged medical therapy underwent successful endoscopic retrograde cholangiopancreatography (ERCP) followed by immediate operative therapy. All of these patients had surgically correctable lesions consistent with chronic pancreatitis. There was one associated mortality and no morbidity. The conditions of the surviving six patients were significantly improved in the immediate postoperative period, and long-term follow-up has been encouraging. Pancreaticojejunostomy and conservative resection appeared to have good results. The timing of the operation immediately after ERCP in patients with acute pancreatic pathology eliminated problems with exacerbation or sepsis. Patients whose clinical conditions do not improve with aggressive medical therapy for acute pancreatitis may have both chronic and acute disease that is amenable to operative therapy.

Acute Disease↗
PubMed1980

Surgical correction of posttransplant renovascular hypertension.

The incidence of renovascular hypertension in the transplanted kidney is reported to range between 5 and 15%. A review of 391 consecutive renal transplant patients revealed 16 patients (5.4%) with hypertension secondary to partial obstruction of renal arterial blood flow. The clinical course of this group of patients was marked by early normotension followed by progressive diastolic pressure elevation, with improving renal function and loss of accumulated excess volume. Five etiologic factors are responsible for impaired arterial flow in this group of patients. Indication for operation was based on hypertension and/or impaired renal function. Patch angioplasty using saphenous veins was the procedure of choice in most instances. The average blood pressure was 185 mmHg; systolic/125 mmHg; diastolic preoperatively, compared with 140 mmHg; systolic/90 mmHg: diastolic postoperatively. Twelve of 16 patients had good results, and improvement in renal function was observed in eight patients. Serum renin levels did not correlate well with the operative findings. The use of meticulous technique, combined with maximum use of autogenous tissue, is emphasized.

Blood Pressure↗
PubMed1980

Extracranial carotid artery injuries.

From December, 1975, to December, 1979, 54 carotid artery injuries have been treated by the Southwestern Medical School Department of Surgery. Seventy-eight percent were due to gunshot wounds, 20% were due to stab wounds, and 2% were secondary to blunt trauma. Thirty-three percent involved the internal carotid artery, and the external carotid artery was involved in 20%. Eighteen percent of the patients presented with a major associated venous injury and 8% with an arteriovenous fistula. Partial or complete disruption accounted for the majority of injuries. There was a 10% mortality rate. Four percent of the deaths were due directly to carotid vascular trauma. Because of our experience we believe, whenever possible, all patients should have the benefit of preoperative arteriography. This allows for a well planned operation and avoids major unnecessary neck dissection. High lesions involving the internal carotid artery may be exposed easily by anterior dislocation of the jaw, thus allowing ready access to the base of the skull. Injuries involving extensive areas of the internal carotid artery (lesions extending intracranially) are best managed by extracranial-intracranial (EC-IC) bypass with internal carotid artery ligation. Severe neurologic deficit is best treated by ligation of the carotid artery. Seven patients have undergone EC-IC bypass and 86% of these returned to or maintained normal neurologic status, while the other 14% remained neurologically stable. It is our impression that the risk of neurologic deficit is lessened by this maneuver without added mortality or morbidity.

Carotid Arteries↗
PubMed1979

Appendicitis and aortofemoral graft infection.

A 59-year-old man who underwent successful aortofemoral bypass had acute appendicitis at an indeterminate time in the postoperative period. Thirteen months later, a pulsatile groin mass developed. After a complicated course, it was found that infection from appendicitis had extended to the body of the graft. This unusual cause of graft infection reaffirms the importance of careful closure of the retroperitoneum over an aortic anastomosis and suggests a relationship of other intra-abdominal inflammatory processes to graft infection.

Acute Disease↗
PubMed1979

Endothelial response to venous injury.

This investigation characterized venous endothelial healing after surgical manipulation. Procedures were performed on jugular and femoral veins in 21 mongrel dogs without systemic anticoagulation. Veins were harvested at varying intervals and vessel structure evaluated with light, transmission, and scanning electron microscopy. Veins that were mobilized or stripped of adventitia demonstrated 25% to 50% endothelial loss at one hour. Endothelial damage was rapidly repaired with complete healing observed in some veins at 48 hours. Tourniquets and clamps resulted in prominent medial and endothelial injury at occlusion sites. Eighteen of 24 transected veins remained patent for the study period. Endothelial healing was unaffected by tension at anastomoses. These observations confirm that venous endothelium receives nutrition by luminal diffusion. The healing process of venous anastomoses is characterized by an early fibrin sleeve sealing the anastomotic site; endothelial bridging of defects can be noticeably delayed by excessive fibrin deposition.

Animals↗