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Biomedical subjects

A Pierro

Publications and source records attributed to A Pierro.

At least 73 records · Page 4Linked to original sources
PubMed1999

Surveillance of Barrett's esophagus in children.

PURPOSE: The aim of this study was to review the need for regular endoscopic biopsy of Barrett's esophagus in children. METHODS: This was a retrospective case-notes review of 38 children with Barrett's esophagus treated between January 1982 and August 1997. The mean age at diagnosis was 6.3 years (range, 1 to 15 years). All had gastroesophageal reflux at diagnosis. Two patients were treated medically, and 36 underwent antireflux surgery (32 Nissen fundoplication, four Thal procedures). At follow-up, for a mean of 43 months (range, 0 to 13 years), 25 underwent repeated endoscopy and biopsies, two underwent further surgery and biopsies, and four underwent endoscopy only. Seven have had follow-up at their referring hospital. RESULTS: In the 27 patients who underwent rebiopsy, there was continued evidence of Barrett's esophagus in 15. There was reversion to normal tissue in 10 patients, and mild esophagitis was present in two. There was no evidence of any dysplastic or malignant change in any patient. All cases that reverted to normal esophagus or mild esophagitis had previously undergone a Nissen fundoplication. CONCLUSIONS: Dysplastic degeneration and malignant change did not occur in any of the authors' patients. In addition, 12 patients with Barrett's esophagus reverted to normal. The authors therefore question whether regular endoscopic surveillance is necessary in children under 16 years of age.

Adolescent↗
PubMed1999

Management and long-term follow-up of infants with total colonic aganglionosis.

BACKGROUND/PURPOSE: Although the survival rate for the infants with total colonic aganglionosis (TCA) has improved significantly, problems with the surgical management continue and the long-term consequences for growth and continence are poorly documented. The aim of this study was to review the experience in the management of 48 patients over a 17-year period (1980 to 1996). METHODS: The medical records of all patients were analyzed with particular emphasis on the number and type of surgical procedures, the attainment of anorectal continence, number of stools per day, and physical development. RESULTS: There were 30 boys and 18 girls. Three (6%) patients died: one of sepsis, one of associated major congenital cardiac anomaly, and one of Moebius syndrome and brain stem dysfunction. Forty-one patients (85%) went on to undergo a pull-through procedure: 38 Duhamel with 13 having Martin modification and three with Soave procedure. Inappropriate surgery (47 procedures) were carried out in 19 (40%) patients before the definitive diagnosis; only four of these infants were admitted primarily to our unit. Thirteen patients had a stoma in aganglionic intestine. An ileostomy was closed in six infants before the diagnosis was established, and six had a previous "negative" laparotomy. Long-term follow-up was possible in 27 patients, of whom 19 (70%) required a total of 39 additional procedures. Ten patients underwent a total of 16 anal dilatations and six underwent sphincterotomy. A permanent stoma was necessary in six patients (two with Down's syndrome). Two patients with Martin modification required resection of the side-to-side anastomosis for intractable diarrhea. The number of the stools per day decreased yearly. Fecal incontinence was common at the 5-year follow up (82%). However, at 10 and 15 years, the rate of incontinence decreased to 57% and 33%, respectively. The proportion of patients below the second percentile for body weight were 25% at 5 years, 20% at 10 years, and 63% at 15 years of age. The equivalent statistics for body height were 15%, 0%, and 23%, respectively. CONCLUSIONS: Patients with TCA tend to undergo multiple procedures. Anorectal function improves gradually over time. There are no advantages of the Martin modification. In the long-term follow-up over half of the patients are below the second percentile for weight and one quarter are below the second percentile for height. Careful long-term follow-up is necessary for the patients with TCA.

Colon↗
PubMed1999

Free radical formation in infants: the effect of critical illness, parenteral nutrition, and enteral feeding.

BACKGROUND/PURPOSE: An increase in free radical activity has been observed in patients suffering from a variety of illnesses and has been correlated with disease severity. Free radical production is increased by the administration of total parenteral nutrition (TPN) and may be linked to its adverse effects. Some of the complications of TPN can be ameliorated by partial enteral feeding. The aim of this study was to investigate free radical activity during critical illness and during the administration of parenteral nutrition. METHODS: Three groups of surgical infants were studied: (1) control infants (n = 8) before minor surgery, (2) stable infants on the ward recovering from a major operation (n = 24), (3) critically ill infants in the neonatal intensive care unit (NICU, n = 28). Fourteen patients in the ward and 17 patients in NICU were receiving parenteral nutrition. Of the 31 patients on TPN, 9 were also receiving minimal enteral feeding (3% to 24% of total calorie intake). Plasma malondialdehyde (MDA), an index of free radical activity, was measured in all 60 infants. The Paediatric Risk of Mortality (PRISM) score was obtained on NICU patients. The cytokines tumor necrosis factor (TNF-alpha) and interleukin 6 (IL-6) were measured in 25 patients. RESULTS: Plasma MDA was significantly higher in (1) the stable patients on the ward compared with control patients (P < .001) and (2) patients in NICU compared with stable patients in the ward (P < .001). Parenteral nutrition was associated with higher levels of plasma MDA both in stable patients in the ward and critically ill infants in NICU. There was no correlation between the PRISM score and MDA. In patients not receiving TPN there is a correlation between MDA and TNF-alpha (r = 0.54, P = .02) and between MDA and IL-6 (r = 0.74, P = .001). The level of free radical activity in patients on TPN is not changed by partial enteral feeding. CONCLUSIONS: Critical illness causes a rise in free radical production. Parenteral nutrition causes a significant elevation in free radical activity in both stable infants in the ward and critically ill infants in NICU. The addition of minimal enteral feeding to parenteral nutrition does not reduce free radical activity. We hypothesize that the parenteral nutrition solution directly initiates free radical production.

Analysis of Variance↗
PubMed1999

Necrotizing enterocolitis: extent of disease and surgical treatment.

PURPOSE: The aim of this study was to evaluate the results of surgical treatment of necrotizing enterocolitis (NEC) according to the extent of disease and to establish if resection of the ileocecal valve represents a poor prognostic factor. METHODS: The authors reviewed all cases of NEC (n = 161) treated in our hospital during the last 11 years; of these, 83 required surgical intervention. Definitions used by the authors include isolated, disease in a single intestinal segment; multifocal, disease in two or more intestinal segments; and pan-intestinal, majority of small and large bowel involved. RESULTS: Twenty-five neonates had isolated NEC, 46 neonates had multifocal NEC, and 12 had pan-intestinal involvement. Survival rate was affected by the extent of intestinal involvement, the lowest survival rate (33%) being noticed in neonates with pan-intestinal involvement. In patients with isolated NEC, postoperative complications and survival rate were not affected by the modality of operative treatment. Conversely, in patients with multifocal NEC, survival rate was higher (85%) after resection and primary anastomosis compared with enterostomy (50%; P =.03). Resection of the ileocecal valve was not associated with increased morbidity and mortality. CONCLUSIONS: (1) Resection and primary anastomosis is a valid treatment option in both isolated and multifocal NEC. (2) Neonates with NEC adapt rapidly to the loss of the ileocecal valve.

Anastomosis, Surgical↗
PubMed1999

Neonatal oxidative liver metabolism: effects of hydrogen peroxide, a putative mediator of septic damage.

BACKGROUND/PURPOSE: Surgical neonates are at risk for sepsis and liver dysfunction. These complications are more common in preterm neonates and in those who receive total parenteral nutrition. Elevated levels of reactive oxygen species (eg, hydrogen peroxide) have been reported in these "at-risk" patients and may be the mediators of liver impairment via their effect on oxidative energy metabolism. The aim of this study was to test the hypothesis that elevated levels of hydrogen peroxide (H2O2) impair neonatal liver oxidative energy metabolism. METHODS: An in vitro model to test this hypothesis was developed in hepatocytes isolated from neonatal (11-day to 15-day) rats. The cells, respiring on palmitate (0.5 mmol/L in 2% bovine serum albumin), were exposed to H2O2. Oxygen consumption was measured polarographically. In experiment A, H2O2 was added to the cell preparation at different concentrations (0.5 mmol/L, 1 mmol/L, 1.5 mmol/L, 2 mmol/L) to assess the effect on oxygen consumption. In experiment B, H2O2 (2 mmol/L) was added to hepatocytes in the presence of inhibitors of mitochondrial respiration to define the site of action of H2O2. In experiment C, electron microscopy was performed on hepatocytes after incubation with 1 mmol/L and 2 mmol/L of H2O2. RESULTS: In experiment A, H2O2 significantly reduced hepatocyte oxygen consumption at 1.5 and 2 mmol/L. In experiment B, in the presence of inhibitors of mitochondrial respiration, myxothiazol (inhibitor of substrate oxidation), and oligomycin (inhibitor of adenosine triphosphate (ATP) synthase), no further inhibition by H2O2 occurred, indicating that the effect of H2O2 was intramitochondrial and affecting the synthesis of ATP. In experiment C, microscopic alterations of mitochondria were noticed exclusively in hepatocytes incubated with 2 mmol/L H2O2. CONCLUSIONS: Results of this study demonstrate that H2O2 impairs neonatal liver oxidative metabolism. H2O2 probably directly inhibits ATP synthase. The authors hypothesize that H2O2 may play a role in the biochemical pathogenesis of liver dysfunction associated with sepsis. Identification of the precise target site of H2O2 may be valuable in directing therapy in septic neonates.

Adenosine Triphosphate↗
PubMed1999

Differential energy metabolism in conjoined twins.

BACKGROUND/PURPOSE: Conjoined twins often have different body composition and growth rate before separation. This may be because of differences in energy metabolism. The aim of this study was to investigate the energy expenditure, body composition, and calorie intake of thoracopagus conjoined twins with shared hepatic circulation but separate gastrointestinal tracts. METHODS: The twins were studied at two periods: (1) before separation (age, 73 days) and (2) after separation (age, 97 days). Calorie intake over the study periods was carefully documented. Respiratory gas exchange was measured by computerized indirect calorimetry. The postseparation weight ratio of twin A to twin B was used to approximate the preseparation weights. Body composition (total body fat) was calculated from skinfold thickness and anthropometric measurements. RESULTS: The body composition of the twins was different: body weight and total body fat were higher in twin B. Resting energy expenditure and calorie intake were markedly different between the conjoined twins before separation. In both twins, the energy expenditure increased after separation. After separation, the resting energy expenditure of the twins was similar. CONCLUSIONS: This study illustrates the difference in energy metabolism in a set of thoracopagus conjoined twins. The authors speculate that twin A was supplying nutrients to twin B resulting in increased energy expenditure before separation. This would explain the lower calorie intake and higher fat mass of twin B.

Energy Metabolism↗
PubMed1999

Metabolic response to neonatal surgery.

The energy and protein metabolism of newborn infants differs from that of older individuals. Although energy expenditure and protein turnover are higher in newborn infants than in adults, the metabolic response to surgery in neonates has not been fully characterized. Preliminary studies indicate that metabolic response to operative stress is different in infants and adults: infants have an increased metabolic rate postoperatively for only 6 to 12 hours and do not have increased protein catabolism. More studies are needed in "stressed" newborn infants to further characterize substrate use and the metabolism of single organs.

Anesthesia, General↗
PubMed1998

Evidence-based operations in paediatric surgery.

It has been assumed that only 10% of medical interventions are supported by solid scientific evidence. The aim of this study was to determine the type of research evidence supporting operations in a tertiary referral paediatric surgical unit. All patients admitted over a 4-week period to two surgical firms were enrolled in the study. All major operations carried out on each patient since birth were evaluated. Patients for whom a diagnosis was not reached were excluded. A bibliographic database (MEDLINE) was used to search for the articles published between January 1986 and December 1995 on the analysed operations. The type of evidence supporting the operations was classified as follows: I=evidence from randomised controlled trials (RCTs); II=self-evident intervention (obvious effectiveness not requiring RCTs); III=evidence from prospective and/or comparative studies; IV=evidence from follow-up studies and/or retrospective case series; and V=intervention without substantial evidence for or against results of randomised trials. Seventy operations (32 individual types) were performed on 49 patients (1-5 operations/patient); 18 (26%) were supported by RCTs (type of evidence I). Two patients (3%) received a self-evident intervention (type II); 48 operations (68%) were based on non-randomised prospective or retrospective studies (type III=13%; type IV=55%). Two patients (3%) received an operation not supported by or against convincing scientific evidence (type V). A significant proportion of operations in paediatric surgery is supported by RCTs. However, the vast majority of these trials were conducted on adult patients. Sixty-eight per cent of the operations were based on prospective follow-up studies or retrospective case series, which may not represent solid scientific evidence. More RCTs are needed in paediatric surgery.

Child↗
PubMed1998

Fentanyl analgesia increases the incidence of postoperative hypothermia in neonates.

Postoperative hypothermia remains a clinical problem in neonates undergoing surgery. Intraoperative analgesia can blunt the metabolic and hormonal response to operative stress in neonates. However, its effects on heat production and thermoregulation are not known. The aim of this review was to characterise the effects of intraoperative analgesia on body temperature in neonates undergoing surgery. The case notes of 25 consecutive neonates who underwent major operations were retrospectively reviewed. Axillary temperature was measured before the operation, and postoperatively after returning to the neonatal intensive care unit (NICU). Patients were divided into groups based on the intraoperative analgesic used: (1) 9 neonates received fentanyl; (2) 5 received morphine; and (3) 11 received epidural bupivacaine. All groups were comparable in terms of conceptional age, postnatal age, body weight, duration of operation, and operative stress score. In all groups the body temperature was significantly lower at the time of returning to the NICU than preoperatively. Three patients (33%) who received fentanyl became hypothermic during the operation, whereas none of those who received either morphine or bupivacaine had hypothermia. The drop in temperature between preoperative and initial postoperative values was significantly greater in patients who received fentanyl intraoperatively (median drop 0.8 degreesC, range 0.6 - 2.4) when compared with patients who received morphine (P = 0.02) or epidural bupivacaine (P = 0.01). These data suggest that intraoperative fentanyl modulates the postoperative body temperature in neonates. We hypothesise that fentanyl blocks metabolic heat production, which results in a reduction in postoperative body temperature.

Analgesia↗
PubMed1998

Hemisplenectomy for giant splenic cysts in children.

To analyse the clinical features and outcome following surgery of giant splenic cysts in children, all patients presenting to a children's hospital over the years 1987-1996 were reviewed. Variables analysed included presenting symptoms, method of diagnosis, operative procedure, and complications. Six patients (aged 8-16 years) presented with abdominal pain or a large abdominal mass. Ultrasound examination demonstrated large (>5 cm) unilocular splenic cysts. Five of the six children underwent hemisplenectomy without complication or blood transfusion. The remaining patient had an infected cyst, for which total splenectomy was necessary because of major intraoperative haemorrhage. Hemisplenectomy is based on accurate dissection of the splenic hilum with clear knowledge of the intracapsular vascular anatomy of the spleen. Preoperative vaccination is recommended in the event that splenectomy is required. This retrospective review concludes that hemisplenectomy for splenic cysts is a safe procedure in children.

Adolescent↗
PubMed1998

Small volumes of enteral feedings normalise immune function in infants receiving parenteral nutrition.

BACKGROUND/PURPOSE: Parenteral nutrition (PN) is associated with a risk of septicaemia. This may be caused by impairment of immune function related to PN. The authors investigated the effects of the addition of enteral feedings to PN on the immune status of human newborn infants. METHODS: Ten surgical infants (age less than 6 months) requiring PN were studied in two consecutive phases: (A) after 31.1+/-6.0 days (mean +/- SEM) of PN with no enteral feeding (total PN); and (B) after 4.7+/-1.1 days from the addition of small volumes of enteral feeding to PN. Full blood count and liver function tests were not significantly different between phases A and B. A control group (n = 9) of infants receiving a normal enteral diet was also studied. Host bactericidal activity against coagulase-negative staphylococci (CNS) was measured by an in vitro whole blood model. Bacterial killing was measured after a 45-minute bacterial challenge using the Miles-Misra technique. Tumour necrosis factor-alpha (TNF-alpha) was measured by enzyme-linked immunosorbent assay (ELISA) after 2 hours of bacterial challenge. RESULTS: The lowest level of CNS killing (37.7+/-5.2%), was observed in patients receiving total PN. This increased significantly after the addition of small enteral feeds (52.0+/-4.6%, P < .005) approaching the levels measured in controls (65.1+/-3.4%). TNF-alpha production was low during total PN (1467+/-297 pg/mL) and rose significantly after the addition of minimal enteral feeds (4,661+/-1,311 pg/mL, P < .05). The increase in CNS killing after the addition of small enteral feeds in patients on PN was significantly correlated with the duration of enteral feeding (r = 0.8, P = .006). CONCLUSIONS: These results indicate that the introduction of small volumes of enteral feed improve the impaired killing of CNS and the abnormal cytokine response observed during total PN. This implies that stimulation of the gastrointestinal tract may modulate immune function in neonates and prevent bacterial infection.

Bacteremia↗
PubMed1998

Primitive neuroectodermal tumours: anatomic location, extent of surgery, and outcome.

BACKGROUND/PURPOSE: Primitive neuroectodermal tumours (PNET) are rare tumours sharing similar histology, immunohistochemistry, and cytogenetics to Ewing's sarcomas. The aim of the study was to document the effect of site of origin and the completeness of surgical excision on the outcome in infants and children with PNET. METHODS: All patients (n = 26) with PNET treated in our hospital during the last 6 years were included in the study. The diagnosis was based on the histopathologic findings and a positive MIC2 antibody test. The tumours were classified according to the Intergroup Rhabdomyosarcoma Study III, and were treated according to the UKEESG protocol for Ewing's Sarcoma. RESULTS: Complete remission (CR) was achieved in 52% of the patients completing their chemotherapy. Overall, survival was 42% (11 of 26). Tumours from the paraspinal and scapula areas responded relatively well (CR, 83%), whereas abdominal PNET did not respond to treatment. Tumours arising from the head, neck, or chest had an intermediate prognosis (37% survival). Three of the 10 patients who had a complete excision of the tumour died of progressive disease. CONCLUSIONS: Complete surgical excision reduced the risk of local recurrence but did not prevent metastatic spread. These data indicate that PNET have a worse prognosis and different favourable sites than other sarcomas. New treatment strategies are necessary for these rare tumours.

Abdominal Neoplasms↗
PubMed1998

Effect of major abdominal operations on energy and protein metabolism in infants and children.

PURPOSE: The authors attempted to test the hypothesis that infants and children increase whole-body protein flux and energy metabolism during the early postoperative period. METHODS: Ten infants and children (age range, 2 days to 3 years; weight range, 1.5 to 14.2 kg) who had undergone a major operation were studied. Anaesthesia was standardised, and operative stress score (OSS) recorded. Patients were studied for 4 hours preoperatively and for the first 6 hours after surgery. Respiratory gas exchange was measured by computerised indirect calorimetry. The components of whole-body protein turnover were estimated by giving an intravenous infusion of [1-13C]leucine, and by measuring the isotopic enrichment of plasma [13C]alpha-ketoisocaproic acid by gas chromatograph mass spectrometry and 13CO2 enrichment by isotope ratio mass spectrometry. RESULTS: Median duration of the operation was 73.5 minutes (range, 28 to 285 minutes) with a OSS of 8 (range, 7-17). There were no significant differences in oxygen consumption and resting energy expenditure between the two study phases. The respiratory quotient (RQ) fell from a preoperative value of 0.92 (range, 0.81 to 1.08) to 0.89 (range, 0.79 to 0.95) postoperatively (P = .04). The authors found no significant differences in the rates of whole body protein flux, protein synthesis, amino acid oxidation, and protein degradation between the study phases. CONCLUSIONS: Infants and children do not increase their whole-body protein turnover and metabolic rate after major operations. The observed decrease in RQ reflects mobilisation of endogenous fat. We speculate that the lack of catabolism observed in children is caused by a diversion of protein synthesis from growth to tissue repair.

Abdomen↗
PubMed1998

Bolus intravenous infusion of amino acids or lipids does not stimulate gallbladder contraction in neonates on total parenteral nutrition.

BACKGROUND/PURPOSE: Stimulation of gallbladder contraction in patients receiving total parenteral nutrition (TPN) may be beneficial in preventing cholestatic jaundice associated with TPN. Bolus intravenous administration of either amino acids or fat promotes gallbladder contraction in normal adult volunteers after a period of starvation. This phenomenon has not been investigated in patients receiving continuous TPN. The aim of this study was to test the hypothesis that bolus intravenous infusion of amino acids or fat produces gallbladder contraction in neonates receiving TPN. METHODS: Twenty-eight studies of gallbladder contraction were performed in 18 neonates receiving continuous TPN (median weight, 2.3 kg; range, 1.3 to 7.3; gestational age, 37 weeks; range, 28 to 40; age, 6.5 days; range, 2 to 180). Different types of experiments were performed: (1) bolus intravenous infusion of amino acid or fat for 60 minutes at twice the normal infusion rate; (2) bolus intravenous infusion of amino acid or fat for 15 minutes at four times the normal infusion rate. Gallbladder volume was measured by real-time ultrasonography by a single investigator. Measurements were made before starting the bolus infusion and every 15 minutes for 1 hour. RESULTS: The volume of the gallbladder before bolus intravenous infusion was not significantly different between experiments (median, 985; range, 603 to 1,802 mm3). These volumes are consistent with an enlarged and atonic gallbladder as previously reported in infants receiving parenteral nutrition. In all experiments there was no significant decrease in gallbladder volume after bolus infusion of either amino acids or fat. CONCLUSIONS: Contrary to their effects in adults, bolus infusions of amino acids or fat did not induce gallbladder contraction in neonates on TPN. This may have been because of lack of starvation in the neonates and/or the effect of continuous glucose infusion.

Amino Acids↗
PubMed1998

Elective partial splenectomy in childhood.

BACKGROUND & PURPOSE: The indications and results of elective partial splenectomy in children remain uncertain. The aim of this study was to determine (1) the indications for elective partial splenectomy (EPS), (2) the extent of splenic resection, and (3) the complications of EPS. METHODS: Patients who underwent EPS from three centers over a 10-year period (1986 through 1996) were studied. Variables analyzed included clinical presentation and indications for EPS, extent of resection performed, perioperative transfusions, and complications. Postoperatively, splenic viability was determined by regular Doppler ultrasound scan and splenic function on peripheral blood film analysis. RESULTS: EPS was attempted in 12 children for various conditions: giant epithelial cyst (n = 6), hypersplenism and metabolic disease (n = 4), pseudotumor (n = 1), and abscess (n = 1). One procedure was converted to total splenectomy because of thin splenic tissue around an infected giant cyst. No child required transfusion for splenic bleeding. There were no postoperative complications or deaths. Only 7 of the 12 children received prophylactic preoperative immunisation. In the 11 successful cases splenic remnant viability remains confirmed by ultrasound scan and normal blood film. There has been no significant splenic regrowth or recurrent hypersplenism in the four children with metabolic disorders. CONCLUSIONS: EPS is suitable for benign splenic conditions and can be performed without major blood loss. Preoperative vaccination is advisable. Up to 95% of the spleen can be safely removed, basing the blood supply of the residual spleen tissue on peripheral polar vessels, with adequate postoperative function.

Adolescent↗