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Biomedical subjects

R T Soper

Publications and source records attributed to R T Soper.

At least 37 records · Page 2Linked to original sources
PubMed1991

The isolated bowel segment (Iowa model II) created in functioning bowel.

In experimental rats (n = 15), an isolated bowel segment (IBS) was created by (1) initial enteropexy between an 8-cm-long jejunal segment and the liver margin (hepatoenteropexy; Iowa model II) with its proximal and distal ends divided and immediately reanastomosed in an end-to-end fashion to reconstruct the bowel; and (2) secondary division of the IBS mesentery 5 weeks later. The IBS is then completely free of its mesentric and intramural nervous and vascular communications. The viability of the IBS is preserved by vascular collaterals developed at the hepatoenteropexy. Twelve rats proceeded to the second procedure, having tolerated regular rat chow with satisfactory weight gain. The Iowa model II created in functioning bowel was evaluated by contrast studies and myoelectrical activities. Contrast studies demonstrated peristalsis in the IBS. In the myoelectrical recordings, the frequency of slow wave was 32.5 +/- 1.0 in the IBS and 36.3 +/- 0.8 in the normal bowel (P less than .05). During fasting, the migrating motor complex (MMC) was observed to propagate aborally in the IBS in a coordinated fashion. The cyclic period of the MMC was 17.2 +/- 1.1 minutes in the IBS and 15.8 +/- 0.8 minutes in the normal bowel (P = .30). We conclude from this study that (1) the IBS (Iowa model II) retains motor function as demonstrated by successful feeding, as well as contrast studies and myoelectrical recordings that were essentially identical to those in the normal bowel; and (2) the IBS (Iowa model II) has significant research potential for studies of bowel physiology.

Anastomosis, Surgical↗
PubMed1991

The isolated bowel segment (Iowa Model II): absorption studies for glucose and leucine.

A model of the isolated bowel segment (IBS, Iowa Model II) was successfully created in experimental animals using a new surgical technique we developed. The IBS is completely free of its mesenteric attachment, yet its viability is preserved. The technique consists of two staged procedures: (1) initial enteropexy between the anterior margin of the liver and the antimesenteric border of the IBS with its ends forming cutaneous stomas; and (2) division of the IBS mesentery 5 weeks later. The IBS is nourished by vascular collaterals that form at the hepatoenteropexy during the interval between these two procedures. Our previous studies demonstrated preserved viability and motility in the IBS. This study was undertaken to test absorption in the IBS. In 25 rats (experimental group), the IBS (Iowa Model II) was created using an 8-cm-long isolated segment of jejunum. In 15 rats (control group), an 8-cm-long segment of jejunum was arranged to form a Thiry-Vella loop. Five weeks later, the IBS mesentery was divided in the experimental group, and sham laparotomy was performed in the control group animals. Absorption of glucose and leucine was studied in 13 rats of the experimental group and 6 of the control group using a constant single perfusion technique at 3, 8, and 11 weeks after the initial operation. The results were compared between the two groups. There was a 25% to 35% reduction in absorption of glucose and leucine in both groups with the advance of time, but no significant difference was observed between the groups except in leucine absorption at 11 weeks after the initial operation. This study concludes that absorption of glucose and leucine is preserved in the IBS after its mesentery is divided, suggesting that the IBS can be used as a functioning bowel for bowel reconstruction.

Animals↗
PubMed1990

Isolated bowel segment (Iowa Model 1): technique and histological studies.

An isolated bowel segment (IBS) is a viable loop of bowel that is completely free of its mesenteric attachments. We created an IBS by staged procedures: (1) myoenteropexy between the undersurface of the abdominal wall muscle and a jejunal loop that is exteriorized at both ends as mucous fistulae; and (2) division of the IBS mesentery several weeks later. Viability of the IBS is preserved by vascular collaterals that develop at the myoenteropexy during the interval between these two procedures. In this study, histological observation of the IBS was performed to retrospectively determine the optimal interval required for adequate collateral circulation to develop. Twenty-eight rats were subdivided into seven groups of four rats each; each group underwent mesenteric division of the IBS at successive 1-week intervals after myoenteropexy (1 to 7 weeks). The bowel wall structures were histologically examined under light microscopy for each group after mesenteric division. Ischemic changes were observed in the groups in which the intervals were shorter than 6 weeks. With the time interval longer than 6 weeks, no ischemic changes were observed in the intramural ganglia and muscle layers and minimal changes were noted in the mucosa. This study concluded that an IBS can be safely created in the rat that preserve normal bowel structures when its mesentery is divided 7 weeks after myoenteropexy.

Abdominal Muscles↗
PubMed1990

Solitary intrahepatic biliary cyst: diagnostic and therapeutic strategy.

This paper describes a newborn infant in whom an intrahepatic biliary cyst was successfully demonstrated by antenatal ultrasound. Postnatally, percutaneous cyst aspiration and computed tomography enhanced with intravenous cholangiographic contrast proved extremely helpful in the selection of surgical procedure. The lesion was completely removed at 12 weeks of age without complications.

Bile Duct Diseases↗
PubMed1990

Isolated bowel segment (model 1): creation by myoenteropexy.

A surgical technique to create an isolated bowel segment (IBS) that is completely free of its mesenteric attachment, and yet preserves the viability of IBS is described. The procedure consists of (1) initial myoenteropexy between the abdominal wall muscle and the IBS, and (2) secondary division of the mesentery of the IBS 6 weeks later when the vascular collaterals have formed at the myoenteropexy. The IBS created by this technique is useful for the studies of bowel physiology and possible elongation of the bowel in the management of the short-bowel syndrome.

Abdominal Muscles↗
PubMed1990

Aortosternopexy for tracheomalacia following repair of esophageal atresia: evaluation by cine-CT and technical refinement.

During the period of 1 year (1988 to 1989), five infants, aged 3 weeks to 10 months, presented with recurrent respiratory distress following repair of esophageal atresia with tracheoesphageal fistula (EA/TEF). These patients had associated congenital anomalies, including right aortic arch (1), biliary atresia (1), and a long gap that required esophageal elongation by spiral myotomy (1). The patients were evaluated for tracheomalacia using cinecomputed tomography (cine-CT; C-100 Scanner, Imatron, San Francisco, CA), which provides images of eight levels (8-mm interval) simultaneously with 0.7 second time intervals of cine-CT. Dynamic studies of the trachea by cine-CT showed tracheal collapse that was most significant during expiration in the segment immediately above and at the aortic arch. These patients underwent aortosternopexy. Via a right second intercostal approach, the ascending aorta and aortic arch were lifted anteriorly using two to four sutures of 5-0 Tevdek on pledgets placed between the tunica media and adventitia of the side walls of the aorta and the adjacent sternum. Respiratory distress was significantly improved postoperatively. Preliminary experience with these patients allows us to conclude that (1) cine-CT is a useful technique for diagnosing tracheomalacia; (2) it provides objective indication for its correction by aortosternopexy; and (3) the refined technique in placing sutures on the aorta may reduce the surgical risks of aortosternopexy.

Anastomosis, Surgical↗
PubMed1990

Pediatric first rib fractures.

First rib fractures are associated with a high incidence of thoracic, vascular, abdominal, and central nervous system injuries. Usually reported in the adult population, first rib fractures are infrequently described in the pediatric population. We take this opportunity to describe six pediatric patients who sustained traumatic first rib fractures. Overall, five patients required operative intervention. Two patients sustained major vascular injuries which were detected on physical examination and confirmed by arch aortography. In view of the high percentage of patients with vascular injury, first rib fracture in a pediatric patient should prompt a search for major vascular injury.

Adolescent↗
PubMed1990

Ultrafast CT of laryngeal and tracheobronchial obstruction in symptomatic postoperative infants with esophageal atresia and tracheoesophageal fistula.

We evaluated the role of ultrafast CT in the diagnosis and follow-up of nine consecutive, symptomatic infants with suspected laryngeal and tracheobronchial obstruction after surgery for esophageal atresia. With 80% or more area collapse as a criterion for the diagnosis of laryngomalacia and 50% or more for tracheomalacia, six patients had tracheomalacia, one had laryngomalacia, and two had both. Tracheomalacia was focal in four patients and diffuse, involving the thoracic trachea, in the other four. Associated bronchomalacia was present in two patients. The site and degree of abnormality were verified by endoscopy in five of nine patients. The degree of tracheal collapse did not always correlate with the size of the esophageal pouch or with the site of the tracheo-esophageal fistula. These findings support the concept that the larynx and/or tracheal walls are often abnormal in symptomatic infants with esophageal atresia, tracheoesophageal fistula, and airway obstruction. Ultrafast CT was a reliable technique for detecting and assessing the site, extent, severity, and dynamics of airway collapse in five of seven symptomatic infants with congenital tracheoesophageal anomalies when the imaging findings were compared with endoscopic findings and previously published normal standards.

Airway Obstruction↗
PubMed1989

Overview of neonatal surgery.

Neonatal surgery emerged as a fledgling in the 1930s and 1940s in restricted regional centers of the world where the pioneer pediatric surgeons were located. It galvanized into a bona fide pediatric surgical subspecialty during the 1950s, lead by those children's hospitals that developed neonatal surgical units and training centers. These institutions produced increasing numbers of highly trained young pediatric surgeons who fanned out to bring their expertise to other academic surgical centers. The 1960s saw both neonatologists and pediatric surgeons enriching the care of newborns in community and private hospitals in developed countries. Pediatric anesthesiologists, pediatric radiologists, and perinatologists joined ranks in the 1970s, extending care to the fetus as well as the newborn. Technologic developments such as ultrasound, computer tomography (CT), sophisticated ventilators, and advances in parenteral nutrition revolutionized both diagnosis and treatment. Magnetic resonance imaging, ECMO, cine CT, and sophisticated improvements in other areas have increased the scope and expanded the horizons of neonatal care in the 1980s, improving treatment yield and reducing morbidity and mortality of newborns who suffer from major medical and surgical diseases. Singapore, Hong Kong, Korea, and Taiwan recently have built neonatal surgical centers where high-quality care and training is offered. Almost every developing country now has surgeons who are partially or completely trained in pediatric surgery and who are on the faculty of their major medical teaching centers. There is every reason to believe that the next pediatric surgical issue of Clinics in Perinatology will describe further revolutionary advances in the care of the newborn patient, in areas now sacrosanct to perinatologists, neonatologists, and pediatric surgeons of this generation.

General Surgery↗
PubMed1988

Sodium deficit causing decreased weight gain and metabolic acidosis in infants with ileostomy.

The records of 11 infants, 25 to 38 weeks' gestation, with metabolic abnormalities induced by ileostomy fluid losses were reviewed. At operation for necrotizing enterocolitis (NEC) (9) or meconium ileus (MI) (2), they weighed between 1,100 and 3,100 g and were from one to 41 days old. All developed total body sodium depletion and metabolic acidosis from ileostomy bicarbonate loss. In seven, sodium depletion was severe enough to require supplementation; six initially lost or failed to gain weight despite being fed adequate diet and calories. However, after receiving sodium supplementation (three with NaCl and three with NaHCO3), these six patients gained weight and improved their metabolic acidosis. The other five subjects did not initially receive sodium supplementation. Four gained weight; one of these later received supplemental NaHCO3 for a metabolic acidosis. The fifth patient failed to thrive until his ileostomy was closed. All infants initially had urine Na less than 10 mEq/L and normal serum Na. All infants whose urine Na rose above 10 mEq/L and had serum HCO3- greater than or equal to 20 mEq/L grew adequately. A direct relationship existed between ileostomy output and sodium intake required for growth. This expressed mathematically (Na intake = 1.2 + [0.13 x ileostomy output] shows a basal sodium need (with no ileostomy output) of 1.2 mEq/kg/d and an additional requirement of 0.13 mEq/kg/d of sodium for each mL/kg/d of ileostomy output. We conclude that infants with ileostomies are at extreme risk of total body sodium depletion with resultant metabolic acidosis and inadequate weight gain. These infants require sodium supplementation with a combination of NaCl and NaHCO3.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1988

Congenital angiomatoid malignant fibrous histiocytoma. A light-microscopic, immunopathologic, and electron-microscopic study.

We present a case of a congenital angiomatoid malignant fibrous histiocytoma. This rapidly growing lesion, which was located in the subcutis of the left upper arm, was excised at the age of 8 1/2 months. The patient, a girl, was well and free of disease 10 months after surgical removal of the tumor. The tumor appeared grossly encapsulated. The gray-tan tissue contained cystic spaces filled with recent and organizing hemorrhages. Microscopically, the tumor was composed of solid masses of histiocyte- and fibroblast-like cells, inflammatory infiltrate, and multifocal irregular blood-filled spaces, which were predominantly devoid of endothelial cells. The tumor was studied immunohistochemically with antibodies specific for FVIII-related antigen, S-100 protein, epithelial membrane antigen, vimentin, desmin, alpha-1-antitrypsin, muramidase, laminin, and collagen type IV. Ulex europaeus lectin-I was also utilized. These studies, along with our ultrastructural findings, suggest that: (a) the tumor is composed of a mixture of mesenchymal cells; (b) an imperfect angiogenesis may be taking place, resulting in a wide spectrum of vascular structures; and (c) the cell of origin may be a pluripotent mesenchymal cell.

Blood Vessels↗
PubMed1988

Congenital anorectal anomalies: MR imaging.

Twenty-one patients with anorectal anomalies were evaluated with magnetic resonance (MR) imaging. In seven preoperative patients, MR imaging demonstrated the level of atresia correctly by showing the rectal pouch and sphincter muscles. The exact location and development of the sphincter muscles were estimated and associated anomalies involving the kidneys and the spine and its contents were evaluated. In 14 postoperative patients, the location of the pulled-through intestine was examined in relation to the sphincter muscles. MR imaging demonstrated operative complications affecting rectal continence--such as a misplaced neorectum, inadvertently pulled-through mesenteric fat, and an implantation mucous retention cyst--and provided objective data for individuals with persistent incontinence after surgery who were under consideration for repeat surgery. The authors recommend MR imaging in all patients being considered for repeat procedures and in any patient without prior surgery who is suspected of having a high anomaly; any degree of sacral agenesis; or spinal, genito-urinary tract, or cloacal anomalies.

Adolescent↗
PubMed1988

Balloon dilatation of esophageal stenosis in children.

Balloon dilatation of benign esophageal strictures is an accepted mode of therapy in adults. This report describes balloon dilatation in 20 consecutive infants and children. The lesions treated include 11 strictures at surgical anastomotic sites, seven restrictive Nissen fundoplications, and three nonanastomotic esophageal strictures. One patient had two lesions. Most dilatations were performed on an outpatient basis without anesthesia. All strictures responded immediately to dilatation. In most cases, long-term resolution occurred after three or fewer procedures. A subgroup of patients was identified in which a prolonged course of treatment was needed. These included patients with long strictures due to esophageal atresia, patients with chronic severe esophagitis, and patients with strictures at the site of esophageal perforation. No significant complications were encountered. Balloon dilatation of esophageal stenosis in children is effective and safe and should be considered before other methods of treatment are used.

Catheterization↗
PubMed1987

Long-term follow-up for treatment of complicated chronic reflux esophagitis.

In the past 18 years the Nissen fundoplication has undergone a few modifications and changes in our institution and all over the world. The aim of this study is to review the long-term (up to 20 years) results of Nissen fundoplication in 350 patients and to evaluate the effect of major modifications in the technique of fundoplication in these patients. Three hundred fifty patients with symptomatic chronic reflux esophagitis have been treated with Nissen fundoplication in our institution since 1966. They were divided into four groups: patients who had a long, tight fundoplication; patients who had a short, floppy fundoplication; patients with crural approximation; and patients without crural approximation. The preoperative and postoperative findings of these patients were evaluated in each group. Group 1 had more immediate and long-term dysphagia compared with group 2. Also, "gas bloat" syndrome was more prevalent in group 1 than group 2. The location of Nissen fundoplication (chest or abdomen) or the addition of hiatal hernia repair did not change the outcome. In patients with intact Nissen fundoplications, their esophagitis healed, and their symptoms disappeared. The rate of recurrence of symptoms was 5%. Recurrence of symptoms was associated with disruption of the fundoplication, which usually happened within the first two years after operation.

Adolescent↗
PubMed1987

Magnetic resonance imaging as an adjunct to planning an anorectal pull-through.

Magnetic resonance imaging (MRI) is a relatively new diagnostic tool that generates images of sections of the body taken in any plane. We report the use of MRI as a tool to plan surgical procedures in patients with imperforate anus, imaging the pelvis and lumbosacral spine in the sagittal, transverse, and coronal planes. MRI clearly reveals the extent of the pelvic musculature even in patients with severe sacral agenesis. MRI is extremely useful in assessing patients under consideration for reoperation, clearly demonstrating the relationship between the pulled through colon and the "striated muscle complex." A very useful addition is the ability, on the same study, to detect previously unsuspected anomalies such as tethered cord, lipoma of the filum terminale, and renal dysplasia. We conclude that MRI is a very useful examination in selected patients with imperforate anus.

Adolescent↗
PubMed1987

Sacrococcygeal teratoma.

The definition, natural history and prognosis of sacrococcygeal teratoma (SCT) are reviewed. Two cases of SCT are presented in detail. Both were diagnosed well before delivery and required intensive perinatal management. Both babies survived intact after removal of 30-50% of total body mass. Case selection for antenatal therapy remains a problem. Prospects for antenatal therapy are reviewed.

Adult↗