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Biomedical subjects

M M Stone

Publications and source records attributed to M M Stone.

At least 19 recordsLinked to original sources
PubMed1992

Atypical thrombotic and septic complications of totally implantable venous access devices in patients with cystic fibrosis.

The use of vascular access systems in patients with cystic fibrosis (CF) is well accepted, with lower overall complications and maintenance costs than percutaneous silastic catheters. We report our 6 year experience with 22 infusaports in 15 CF patients. Our patients had indwelling catheters for an average of 539 days per catheter (range, 14-2,224 days). These infusaports were used for home antibiotic therapy, blood sampling, and total parenteral nutrition. The overall complication rate was relatively low, 1 in every 1,483 catheter days. Infectious complications were extremely infrequent at a rate of 1 in 5,929 catheter days. The rate of mechanical complications was 1 in 1,976 catheter days. However, superior vena caval syndrome or deep venous thrombosis was associated with 3 of 22 catheters (13.6%). Due to this high incidence of major thrombotic events with the attendant risk of pulmonary embolism, all patients with CF using infusaports and without evidence of liver disease or bleeding problems receive aspirin prophylaxis.

Adolescent↗
PubMed1990

The nephroblastomatosis complex and its relationship to Wilms' tumor.

Nephroblastomatosis (NB), a persistence of abnormal embryonal renal tissue beyond 36 weeks' gestation, is often associated with Wilms' tumor. The exact relationship of NB to the development of Wilms' tumor is unclear. Four cases are presented that elucidate the entire morphological spectrum of this disease. Analyses of these cases suggest these conclusions: (1) the NB complex is a spectrum of lesions from benign multifocal nodular renal blastema, resembling residual nephrogenic zones of immature fetal kidney, to Wilms' tumor; (2) infantile NB is a premalignant variant of Wilms' tumor with a favorable outcome usually, when treated early; (3) neonatal nephromegaly requires a complete evaluation and follow-up imaging; persistence mandates biopsy; (4) "second-look" laparotomy is unnecessary with state-of-the-art imaging; and (5) standardization of terminology is essential.

Female↗
PubMed1989

Prediction of successful primary closure of congenital abdominal wall defects using intraoperative measurements.

To determine whether intragastric pressure (IGP) and central venous pressure (CVP) would reliably predict successful primary closure of congenital abdominal wall defects (omphalocele/gastroschisis) in newborn infants, we developed the following prospective intraoperative management protocol. Following a temporary trial of fascial closure, infants who had an IGP less than 20 mm Hg or an increase in CVP of less than 4 mm Hg were primarily closed. If IGP was greater than 20 mm Hg or if CVP increased by more than 4 mm Hg, the temporary closure of the abdomen was reopened and a prosthetic silo was placed. Ten infants who were less than 24 hours old and averaged 2.7 kg (range, 1.4 to 4.2 kg) and 37-weeks gestation (range, 32 to 41 weeks) were studied. Eight infants met criteria for primary closure. Their IGP averaged 14 +/- 4 mm Hg (+/- SD) (range, 8 to 19 mm Hg), and their increase in CVP averaged 1 +/- 2 mm Hg (range, -2 to 3 mm Hg). In the two infants who required staged repair, IGP averaged 25 +/- 1 mm Hg (+/- SD) (range, 24 to 25 mm Hg), and the increase in CVP averaged 7 +/- 1 mm Hg (range, 6 to 8 mm Hg). All patients were anesthetized with fentanyl (12.5 micrograms/kg) and paralyzed with metocurine (0.3 mg/kg) intraoperatively. There were no postoperative complications in either group of patients related to increased intraabdominal pressure, and all patients were extubated within 48 hours of the initial surgery. We conclude that the intraoperative measurement of changes in IGP and CVP can serve as a guide to the operative management of congenital abdominal wall defects and can reliably predict successful outcome following repair.

Abdominal Muscles↗
PubMed1989

Bilateral ureteral obstruction: an unusual complication of pancreatitis.

A case of bilateral ureteral obstruction associated with alcoholic pancreatitis in a 40-yr-old male patient is reported. Although pancreatitis complicated by pseudocyst formation has been known to involve intra- and extraabdominal organs, bilateral ureteral obstruction has not been reported. We postulated that in the case reported herein, periureteral fat necrosis involving both ureters was the primary etiological mechanism.

Adult↗
PubMed1986

Surgical management of peritoneal dialysis catheters in children: five-year experience with 1,800 patient-month follow-up.

Currently at our institution more than 90% of the children with end-stage renal disease are managed with continuous ambulatory peritoneal dialysis (CAPD) in preference to hemodialysis until a successful transplant is accomplished. Recent refinements in CAPD catheters and dialysis techniques have greatly added to the many medical, psychological, and economic advantages of CAPD compared with chronic hemodialysis. Ninety-three patients less than 21 years of age underwent insertion of 167 peritoneal dialysis (PD) catheters over a 5-year period. A variety of PD catheters were used, including 121 (73%) double-cuff Tenckhoff catheters, 22 (13%) single-cuff, and 24 (14%) column disc catheters (Lifecaths, Physio-Control Corp, Redmond, WA). There were three (3%) noncatheter-related mortalities and minimal significant morbidity during the 1,819 patient-months of catheter use. Exit site infections (61%) and peritonitis (59%) were frequent but minor complications, occasionally requiring catheter replacement. Other noninfectious complications included abdominal hernias (42%), dialysis leaks (14%), distal cuff extrusion (11%), catheter obstruction (7%), and hydrothorax (2%). Forty-five of the 60 hernias (75%) were surgically repaired in patients while receiving CAPD. Persistent or recurrent peritonitis was common with Pseudomonas, Serratia, and fungal infections and often resulted in catheter removal and loss of the peritoneal dialysis membrane. Catheter survival for the double-cuff Tenckhoff was significantly better (P .005) than the single-cuff or Lifecath. Based on this experience we have found that using specific operative techniques for CAPD catheter placement and early surgical management for severe peritonitis reduces the incidence of complications and modality failure.

Adolescent↗
PubMed1986

Trophic effect of amniotic fluid on fetal gastrointestinal development.

To determine if amniotic fluid or its constituent trophic factors influence fetal gastrointestinal tract development we developed models of fetal esophageal ligation to prevent swallowing of amniotic fluid and fetal esophageal cannulation with infusion of various substances to mimic fetal swallowing. A total of 43 fetuses was studied. Esophageal ligation resulted in a 32% reduction in gastric weight and a 40% reduction in serum gastrin level, compared to unoperated controls, whereas intestinal and liver weights were unchanged. Gastric acid concentration averaged 43.4 +/- 7.7 mumole/ml in control fetuses, but only 0.5 +/- 0.5 mumole/ml following esophageal ligation. Infusion of Ringer's lactate solution intragastrically did not prevent the changes in gut development seen after esophageal ligation. In contrast, infusion of bovine amniotic fluid resulted in relatively normal gut development, with a gastric acid concentration of 28.5 +/- 6.9 mumole/ml and liver and gastric weights and serum gastrin levels no different from control. Epidermal growth factor had a potent trophic effect on both somatic and gastrointestinal fetal growth and resulted in a mean gastric acid concentration of 35.2 +/- 6.6 mumole/ml. In contrast, pentagastrin, although restoring gastric weight to control values, had no effect on gastric acid secretion, with a mean of 0.1 +/- 0.1 mumole/ml. We conclude that fetal swallowing of amniotic fluid is essential in fetal gastrointestinal development, possibly via luminal trophic actions of peptides such as epidermal growth factor and gastrin.

Amniotic Fluid↗
PubMed1986

Comparison of the myoelectrical activity of the lateral and J-shaped ileal reservoirs.

Ileal myoelectrical activity was studied in ten 10-cm J-shaped and ten lateral ileal reservoirs (IR) in rabbits. Electrodes and a strain gauge were placed on both ileal segments of the reservoirs as well as the proximal and distal ileum entering and leaving the reservoirs. In three additional rabbits without reservoirs (controls), electrodes and a strain gauge were sutured to the distal ileum in a similar manner. Myoelectrical activity was recorded as (1) short spike burst complexes (SSBC) lasting greater than 25 seconds but less than three minutes, and (2) long spike burst complexes (LSBC) lasting more than three minutes. SSBC propagated through the lateral IR two weeks after its construction and were synchronous with intestinal contraction. In contrast, SSBC did not become organized or propagate distally through the J-shaped IR until eight weeks after reservoir construction. LSBC occurred infrequently in control rabbits and in those after construction of the J-shaped and lateral IRs. Propagation of LSBC in control rabbits was synchronous with prolonged propulsive intestinal contraction. In both the J-shaped and lateral reservoirs, LSBC occurred randomly and did not propagate from proximal to distal ileum through the IR until three months after reservoir construction. The frequency and duration of LSBC remained diminished for the J-shaped IR at three months when compared with the lateral IR. It is concluded that the return of normal propulsive activity occurs earlier in the lateral iso-peristaltic IR than in the J-shaped IR but that both are effective at three months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Colonic obstruction in a child with von Recklinghausen's neurofibromatosis.

A child is reported who developed partial colonic obstruction from an intussuscepting polypoid mass in the transverse colon. A 5 cm plexiform ganglioneurofibroma was found at laparotomy. Examination of the entire gastrointestinal tract revealed no other neurogenic tumors. Gastrointestinal involvement by neurofibromatosis in children is rare; however, children with von Recklinghausen's disease who complain of vague abdominal symptoms should be evaluated for gastrointestinal tumors.

Child↗
PubMed1986

Long-term total intraperitoneal nutrition in a rabbit model.

Total intraperitoneal (IP) nutrition was studied in a rabbit model. A mixture of 10% dextrose, 2% amino acids, and 3% lipids was continuously administered to 28 rabbits as their sole nutritional source for 21 days. Twenty rabbits received the solution via IP catheters; 8 of these underwent 50% small bowel resection (SBR) prior to IP infusion. As controls, 8 rabbits were administered the same solution intravenously (IV-TPN). Survival was 75% in both experimental and control groups. Weight gain was similar in IV- and IP-infused rabbits after 21 days. No significant decrease in body weight or changes in blood chemistry occurred after 50% SBR. A mild chemical peritonitis was seen with IP nutrition which resolved after discontinuing the infusions. Biochemical and histologic liver toxicity was more severe in the IV controls than the IP-infused rabbits. We conclude total calorie support can be delivered thorough the peritoneal cavity on a long-term basis; 50% SBR minimally affects IP absorption of nutrients; and the liver dysfunction seen after IV-nutrition is less severe with IP nutrition.

Animals↗
PubMed1986

Esophageal replacement with colon interposition in children.

During a 21-year period, 39 colon interposition operations were performed on 37 children at the UCLA Medical Center and the Childrens Hospital of Los Angeles. The average age at the time of operation was 5.8 years. The indications for operation were esophageal atresia in 23 patients and other benign strictures in 14 patients. The duration of patient follow-up ranged from 6 months to 21 years (mean: 9.7 years). The most common complications were esophagocolonic anastomotic leak (12), esophagocolonic anastomotic stricture (14), pneumonia, and pneumothorax. Fourteen of the 25 patients with retrosternal colon interposition had complications (56%), whereas 10 of 14 patients with left thoracic colon interposition had complications (71%). One patient died (mortality: 3%) after left thoracic interposition because of severe respiratory distress associated with other malformations. Each of the 18 patients with isoperistaltic colon interposition showed rapid transit and emptying, provided that obstruction or extensive dilatation did not occur; reverse colon segments were more dilated and emptied more slowly. The 25 patients with retrosternal colon segments had less colonic distension with better emptying than did the 14 patients with left thoracic interposition. Thirty-two of the 36 children increased their weight percentile after colon interposition. Within 2 years after cervical anastomotic stricture or leak, 78% of these children were asymptomatic and gaining weight. Thirty-one of the 37 patients (84%) had excellent results with colon interposition, with a mean follow-up of 9.7 years. Most of the major postoperative complications occurred within the first few weeks and were corrected during the first few months after operation. Preservation of the esophagus should be the surgeon's first priority; however, prolonged attempts to elongate the esophagus for anastomosis in certain patients with long-gap esophageal atresia have been more hazardous in our experience than has colon interposition.

Adolescent↗
PubMed1986

Late obstruction of the lateral ileal reservoir after colectomy and endorectal ileal pullthrough procedures.

During a period of eight years, 19 of 83 patients underwent colectomy, mucosal proctectomy and endorectal ileal pull-through procedures with isoperistaltic ileal reservoir for ulcerative colitis or polyposis. These patients had late obstruction of the ileal reservoir develop which lead to distension, stasis, reservoir inflammation and diarrhea. In nine patients, the reservoir obstruction as due to a lengthy rectal muscle canal and a longer distance from the lower end of the reservoir to the anus than was optimal, causing angulation and obstruction. Surgical division of the upper rectal muscle and retraction of the reservoir further into the pelvis combined with resection of the elongated upper end of the ileal reservoir were followed by relief of symptoms in every patient. Five patients had intestinal adhesions develop necessitating resection of a segment of the upper ileal reservoir. Five other patients had obstruction develop from an internal hernia; each required resection of the redundant upper portion of the reservoir. Each of the patients was relieved of diarrhea and gaseous distension after the obstruction was corrected and the ileal reservoir was shortened. The optimal length of ileal reservoir is approximately 10 to 15 centimeters for children and 18 to 22 centimeters for adults. Resection of all except 5 to 7 centimeters of rectal muscle cuff and placement of the lower end of the ileal reservoir within 3 to 5 centimeters of the ileoanal anastomosis appeared to reduce substantially the incidence of reservoir obstruction. Reservoir obstruction has not been observed in the last 37 patients who have undergone operation.

Adolescent↗
PubMed1985

The role of amniotic fluid in fetal nutrition.

The contribution of amniotic fluid to fetal growth and gastrointestinal tract development was studied in a rabbit model. In the fetal rabbit, at 23 days gestation, 3 conditions were surgically produced: (1) prevention of swallowing of amniotic fluid by esophageal ligation (n = 8); (2) esophageal ligation but insertion of an esophageal cannula distally to allow continuous infusion into the stomach of bovine amniotic fluid to mimic fetal swallowing (n = 7); and (3) sham operation (n = 7). Fetuses were delivered by Caesarean section at 28 days gestation. Esophageal ligation resulted in significant reductions of birth weight and crown-rump length and a trend to decreased liver weight when compared to sham operated controls. Additionally, marked reductions in gastric and intestinal tissue weight and gastric acidity were found following esophageal ligation. These reductions in both somatic and gastrointestinal tract growth and gastric function were reversed by infusion of amniotic fluid intragastrically. We conclude that amniotic fluid provides 10% to 14% of the nutritional requirements of the normal fetus, and that amniotic fluid contains a potent and as yet undefined gastrointestinal tract trophic factor.

Amniotic Fluid↗
PubMed1978

Genetic factors in leprosy: a study of children in Uganda.

A group of 20 990 children in Uganda was examined for leprosy over a period of 8 years. There was no evidence that the incidence of leprosy varied according to a child's genetic relationship to a leprosy patients, once allowance had been made for the grade of physical contact.

Child↗