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Biomedical subjects

A C Fiore

Publications and source records attributed to A C Fiore.

64 records · Page 4Linked to original sources
PubMed1985

Isthmus flap aortoplasty: an alternative to subclavian flap aortoplasty for long-segment coarctation of the aorta in infants.

The ideal operation for infants with coarctation of the aorta remains controversial. Subclavian flap aortoplasty is the most popular technique for this age group. The 5 to 20% recurrence rate is attributed to regrowth of the coarctation web or inadequate length of the subclavian flap, particularly when the aortic isthmus is long and narrow. Severe arm ischemia following subclavian flap aortoplasty, although rare, is a disturbing complication. The purpose of this study is to report the results with a new technique we call isthmus flap aortoplasty for coarctation of a long segment of the aorta in infants. This technique avoids the limitations of subclavian flap aortoplasty. A short segment of aorta, including the ductal entrance and coarctation web, was resected in 4 infants (mean age, 35.5 days) with long-segment coarctation. The posterior wall of the long isthmus was opened longitudinally to the level of the transverse aortic arch. The descending aorta was mobilized and advanced to the level of the aortic arch where the posterior half was sutured. The anterior flap of attached isthmus was then sewn into a longitudinal incision made in the anterior wall of the descending aorta. All infants survived this procedure and had no gradient at completion of the repair. The mean transconduit gradient at rest was zero and rose to 7.0 +/- 0.93 mm Hg after angiography at a mean follow-up of 42 months. Aortograms demonstrated that the reconstructed area had grown in girth and attained a normal caliber in each child.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1985

Externally stented polytetrafluoroethylene valved conduits for right heart reconstruction. An experimental comparison with Dacron valved conduits.

Valve-containing conduits have made possible the repair of many congenital anomalies that involve right ventricular-pulmonary arterial discontinuity. The distressing problem of neointimal peel formation with eventual conduit obstruction in patients with Dacron valved conduits has led to the need for premature replacement in many patients. Externally stented polytetrafluorethylene has demonstrated superior patency in the venous system experimentally and clinically and was believed to have potential advantages over Dacron for conduit construction. This study compares the transconduit resistance and the thickness of the neointimal peel in right ventricular-pulmonary arterial conduits constructed of externally stented polytetrafluoroethylene with those of woven Dacron. The 19 mm externally stented polytetrafluoroethylene conduits (Impra, Inc.) containing a Hancock porcine valve (Extracorporeal Inc.) were implanted in six adult mongrel dogs followed by proximal occlusion of the pulmonary artery. In six additional animals, a Dacron valved conduit of similar size and length was inserted. Cardiac output, transconduit gradient, and resistance were measured at operation and at 3 months. All conduits were subsequently explanted, opened longitudinally, and the thickness of the neointimal peel (excluding suture lines) measured. No hemodynamic differences were noted during the 3 month follow-up. However, the thickness of the neointimal peel was fourfold greater in Dacron conduits (609 +/- 144 mu) than in the conduits constructed of externally stented polytetrafluoroethylene (156 +/- 50 mu) (p less than 0.01). The thick peel in Dacron conduits extended into the outflow portion of the porcine valve cusps and prevented their full excision. The neointima in externally stented polytetrafluoroethylene conduits was thin and uniform and did not extend onto the leaflets or limit their mobility. This study demonstrated that the early hemodynamic performance of externally stented polytetrafluoroethylene conduits was comparable to that of Dacron conduits; Dacron conduits were subject to an accelerated rate of peel formation that affected leaflet mobility and may be a factor in early valve degeneration; a thin neointima formed in externally stented polytetrafluoroethylene conduits and valve leaflet motion was preserved. This study showed that externally stented polytetrafluoroethylene conduits offer advantages over Dacron valved conduits and warrant clinical application.

Animals↗
PubMed1985

Pancreas divisum. Detection and management.

Pancreas divisum is a variant of pancreatic ductal drainage. Its existence is being observed more frequently with the widespread use of endoscopic retrograde cholangiopancreatography (ERCP). On occasion, a relative stenosis of the accessory sphincter will cause a symptom complex which includes nausea, vomiting, upper abdominal pain, and intermittent pancreatitis. In 20 patients seen over the past 4 years, symptoms have been severe enough to consider the patient for transduodenal sphincteroplasty. The use of morphine prostigmine stimulation as a screening tool, has been helpful in 79 per cent of the patients in the series. Intravenous secretin has been a valuable adjunct to both ERCP identification and cannulation of the duct, as well as in two patients in whom the diagnosis was only suspected, and confirmed at the operating table. Operative common duct manometry has shown 40 per cent of the patients to have abnormal flow dynamics, suggesting possible disturbance in the biliary sphincter, as well as the accessory pancreatic sphincter. Pathologic examination has demonstrated abnormal gallbladders in nine of nine patients without previous cholecystectomy. The suggested procedure of dual sphincteroplasty has resulted in no mortalities, but a 50 per cent complication rate. Follow-up shows 70 per cent of the patients to be currently asymptomatic, two patients have had recurrent pancreatitis, and four patients have other problems causing continued post-operative pain. This study suggests dual sphincteroplasty is an acceptable form of therapy for patients with pancreatic divisum and no other source for their pain. Further follow-up will be necessary to insure that therapy is truly curative.

Adult↗
PubMed1984

Venous prostheses: improved patency with external stents.

A uniformly successful prosthesis for replacement in the venous system has not been developed. This study assesses the effect of external stents on the patency of polytetrafluoroethylene (PTFE) grafts in the infrarenal vena cava. Under general anesthesia, 21 mongrel dogs underwent midline laparotomy. The infrarenal vena cava was resected and replaced by a standard segment (8 cm X 10 mm) of stented PTFE (12 dogs) and nonstented PTFE (9 dogs). Patency was assessed by contrast venography and the results compared between the two groups. The 7-, 30-, and 90-day patency was 12/12, 10/12, and 9/12, respectively, for stented PTFE and 6/9, 2/9, and 2/9, respectively, for nonstented PTFE. The patency of externally stented PTFE at 30 and 90 days was significantly better than grafts fashioned from PTFE alone (P less than 0.05 by chi-square analysis). These data demonstrate that external stenting improves the early patency of PTFE prostheses in the infrarenal vena cava. Consideration should be given to the clinical use of externally stented PTFE when prosthetic replacement in the venous system is required.

Animals↗
PubMed1983

Reanastomosis of a Hartmann rectal pouch. A simplified procedure.

A new technique has been described that permits easy location of the rectal stump at the time of colostomy closure for the Hartmann procedure. The routine use of a polypropylene (Prolene) suture to define the location of the rectal stump eliminates tedious pelvis dissection, which could injure the ureter or bladder, as well as entering or thinning the rectal wall distal to the new anastomosis.

Colon↗
PubMed1983

The prevention of extra cardiac conduit obstruction: an experimental study.

Acquired right ventricular (RV) extracardiac conduit (ECC) obstruction was studied in an animal model. A 16 mm woven Dacron tube graft was inserted between the right ventricle (RV) and main pulmonary artery (PA) in 18 adult mongrel dogs followed by pulmonary artery occlusion with a Dacron tape. In 9 dogs, the RV anastomosis was maintained with a 16 mm Dacron covered polypropylene stent. The remaining 9 animals with direct suture attachment of the graft to the myocardium served as controls. Cardiac output and transconduit resistance were measured at operation, 6 months, and 1 year. The cardiac output remained the same in both groups. Animals with stented ECC showed little change in transconduit resistance and had a widely patent RV anastomosis at 1 year. Unstented conduits had increased transconduit resistance at 6 months and 1 year (P less than 0.002). Postmortem examination showed fibromuscular ingrowth of the ventricular anastomosis to be the site of the acquired obstruction in unstented extracardiac conduits. The inclusion of a rigid stent in RV-ECC may warrant clinical application to prevent fibromuscular ingrowth and late RV anastomotic obstruction.

Animals↗
PubMed1983

Valved and nonvalved right ventricular--pulmonary arterial extracardiac conduits. An experimental comparison.

Extracardiac conduits are essential in operations for congenital discontinuity between the right ventricle and the pulmonary artery. The disturbing degree of obstruction reported in clinical series of extracardiac conduits containing porcine valves has been attributed in part to early valve deterioration and the development of a thick neonintimal lining within the Dacron graft. This study compares the hemodynamic differences and the thickness of the neointimal lining in right ventricular extracardiac conduits with and without a porcine valve. Woven Dacron conduits (16 mm) were implanted in 15 adult mongrel dogs, and then the proximal pulmonary artery was occluded with Dacron tape. In six dogs, the extracardiac conduit contained a porcine valve, whereas in the other nine it did not. Cardiac output, transconduit gradient, and resistance were measured at operation and 6 and 12 months postoperatively in both groups. No hemodynamic differences were noted. After 1 year, the thickness of the neointimal lining was threefold greater in valved conduits (1,370 +/- 313.1 mu versus 367 +/- 28.07 mu, p less than 0.005). The neointima along the Dacron graft was thickest proximal and distal to the porcine valve. The luminal peel in valved conduits contained fenestrations and intimal flaps, similar to those observed clinically. In our model, a porcine valve in a right ventricular extracardiac conduit is associated with intimal hyperplasia not seen in nonvalved conduits. If the pulmonary vascular resistance is normal, then the absence of a valve within the conduit does not significantly change hemodynamics and may warrant clinical application to prevent late conduit obstruction.

Animals↗
PubMed1982

Surgical management of alkaline reflux gastritis.

Fifty-six patients were treated surgically for alkaline reflux gastritis, in each a consequence of subtotal gastrectomy and vagotomy for ulcer disease. Of these, 41 available for follow-up, 18 of whom had had Henley loop jejunal interpositioning and the remaining 23 Roux-en-Y (long-loop) gastroenterostomy. The conditions of most patients improved with respect to reflux symptoms of pain, vomiting, and weight loss, but the patients with Roux-en-Y procedure had uniformly better results that did those with the Henley loop. Although the Henley loops in this series of patients may have been too short to be completely effective in preventing bile reflux into the stomach, we prefer the Roux-en-Y diversion because it is technically easier and safer.

Adult↗
PubMed1982

Prosthetic replacement for the thoracic vena cava: an experimental study.

The superior vena cava (SVC) and thoracic inferior vena cava (IVC) were replaced in 46 dogs with autologous vein, knitted Dacron, glutaraldehyde-fixed porcine pericardium, unsupported polytetrafluorethylene (PTFE), and externally stented PTFE. After 30 days, patency rates were determined by contrast venography and were 100%, 9%, 50%, 75%, and 100%, respectively. The patency rates of Dacron and glutaraldehyde-fixed pericardium are considered unacceptable when compared to autologous vein (p less than 0.05). Stented PTFE exhibited a patency rate equal to that of autologous vein at 30 days, minimal graft reaction, excellent incorporation by host fibroblasts, and a smooth neointima. The external spiral support added to PTFE enchanced the thromboresistance of this graft in the thoracic venous system. Long-term follow-up is required to determine if the stented PTFE prosthesis remains comparable to autologous vein as a venous conduit.

Animals↗