Maria Francelina Lopes

Grafts of Porcine Intestinal Submucosa for Repair of Cervical and Abdominal Esophageal Defects in the Rat

Porcine small intestinal submucosa (SIS) is a cell-free collagen matrix that has demonstrated its ability as scaffold material for constructive remodeling of damaged or missing tissue. The purpose of this study was to evaluate the morphology and function of esophagoplasty in rat using a porcine SIS scaffold for the repair of a semicircumferential defect in the cervical or in the abdominal esophagus. Sixty-seven rats underwent surgical excision of the anterior wall either of the cervical or of the abdominal esophagus and subsequent repair of the defect with an SIS patch graft. Outcomes of weight gain, signs of dysphagia, hematological and serum chemistry parameters, and barium swallow studies were used to assess the progress of healing and function over a 150-day time period. The grafts were studied for gross changes and histology at predetermined time points. Ninety-four percent of the SIS-treated rats survived, showing no significant differences in survival rate between groups. The grafted animals did well, without signs of dysphagia, and gaining weight. Barium swallow studies showed no evidence of fistula, significant stenosis, or diverticula. No hematological or serum biochemistry abnormalities were found. By 150 days, the SIS graft was replaced with esophageal-derived tissues. Specimens were completely lined by keratinized stratified squamous epithelium and showed complete regeneration of muscle fibers and scarce immunoreactivity for nerve. In the rat model, a patch graft technique using porcine SIS appears to induce esophageal regrowth either in cervical and abdominal esophagus. The repair mechanism occurred through a regenerative healing process.

Early mortality after neonatal surgery: analysis of risk factors in an optimized health care system for the surgical newborn

OBJECTIVE Anesthetic and operative interventions in neonates remain hazardous procedures, given the vulnerability of the patients in this pediatric population. The aim was to determine the preoperative and intraoperative factors associated with 30-day post-operative mortality and describe mortality outcomes following neonatal surgery under general anesthesia in our center. METHODS Infants less than 28 days of age who underwent general anesthesia for surgery during an 11-year period (2000 - 2010) in our tertiary care pediatric center were retrospectively identified using the pediatric intensive care unit database. Multiple logistic regression was used to identify independent preoperative and intraoperative factors associated with 30-day post-operative mortality. RESULTS Of the 437 infants in the study (median gestational age at birth 37 weeks, median birth weight 2,760 grams), 28 (6.4%) patients died before hospital discharge. Of these, 22 patients died within the first post-operative month. Logistic regression analysis showed increased odds of 30-day post-operative mortality among patients who presented American Society of Anesthesiologists physical status (ASA) score 3 or above (odds ratio 19.268; 95%CI 2.523 - 147.132) and surgery for necrotizing enterocolitis/gastrointestinal perforation (OR 5.291; 95%CI 1.962 - 14.266), compared to those who did not. CONCLUSION The overall in-hospital mortality of 6.4% is within the prevalence reported for developed countries. Establishing ASA score 3 or above and necrotizing enterocolitis/gastrointestinal perforation as independent risk factors for early mortality in neonatal surgery may help clinicians to more adequately manage this high risk population.

Effect of traction sutures in the distal esophagus of the rat: a model for esophageal elongation by Foker's method.

SUMMARY This study aimed to evaluate a rat model of esophageal elongation using traction sutures by the Fokers method. After esophageal division and closure of the distal segment at approximately 4 mm from the cardia, traction sutures were placed for progressive stretching until the 7(th) postoperative day in the experimental group (n = 10), whilst no traction sutures were placed in the esophagus of the control group (n = 10). Clinical outcome as well as macroscopic and microscopic esophageal morphology were evaluated in both groups. All rats survived the surgical procedure and the anesthetic recovery period. Disruption of sutures during the traction period occurred in 20% of the rats, which required reoperation. Integrity of the stretched esophagus was confirmed at autopsy in all animals. In contrast to the control group, the experimental group showed a significantly more elongated (average length 6.10 +/- 1.10 mm versus 3.91 +/- 0.17 mm, (P = 0.0001)) and thicker esophagus (average mass 35.9 +/- 3.31 mg versus 15.6 +/- 1.71 mg in the control group, P = 0.0001). Histopathological examination showed a relatively well preserved morphology of the stretched esophagus. These observations suggest that esophageal stretching by traction sutures can be undertaken reliably in a rat model, resulting in elongation and mass increase of the stretched esophagus without important tissue damage. As this model mimics Fokers method, it may serve as a useful model in further research studies and may be used to train in surgical technique.

Fatores preditivos de complicações graves em cirurgia neonatal

OBJECTIVE To investigate the incidence and severity of early postoperative complications and to identify their risk factors in newborns undergoing surgery under general anesthesia. METHODS We conducted a retrospective analysis of data from 437 critically ill newborns undergoing surgery in a tertiary pediatric surgical center, between January 2000 and December 2010. Complications that occurred within the first 30 days after surgery were classified using the Clavien-Dindo system, for which grades III to V were considered severe. We used univariate and multivariate analysis to evaluate pre- and intraoperative variables potentially predictive of severe postoperative complications. RESULTS The incidence of at least one serious complication was 23%, with a median of one complication per patient 1:3. Altogether, there were 121 serious complications. Of these, 86 required surgical, endoscopic or radiological interventions (grade III), 25 endangered life, with uni or multi-organ failure (grade IV) and ten resulted in death (grade V). The most common complications were technical (25%), gastrointestinal (22%) and respiratory (21%). We identified four independent risk factors for severe postoperative complications: reoperation, operation for congenital diaphragmatic hernia, preterm birth less than 32 weeks of gestational age and abdominal surgery. CONCLUSION The incidence of severe postoperative complications after neonatal surgeries under general anesthesia remains high. The conditions considered independent risk factors for those can guide interventions to improve results.

Juvenile polyposis of infancy in a child with deletion of BMPR1A and PTEN genes: surgical approach.

Juvenile polyposis of infancy is the most severe and life-threatening form of juvenile polyposis. This disease typically presents in the first two years of life with gastrointestinal bleeding, diarrhea, inanition, and exudative enteropathy. In very few reports concerning this entity, a large deletion in the long arm of chromosome 10 (10q23), encompassing the PTEN and BMPR1A genes, was found. The authors report a case of delayed diagnosis of juvenile polyposis of infancy at 6 years of age. A 3.34 Mb long de novo deletion was identified at 10q23.1q23.31, encompassing the PTEN and BMPR1A genes. The disease course was severe with diarrhea, abdominal pain, inanition, refractory anemia, rectal bleeding, hypoalbuminemia, and exudative enteropathy. A sub-total colectomy, combined with intraoperative endoscopic removal of ileal and rectal stump polyps, was required for palliative disease control.

Lasting Developmental Effects of Neonatal Fentanyl Exposure in Preweanling Rats

The present study aimed to determine whether neonatal treatment with fentanyl has lasting effects on stressed developing brain. Six-day-old rats were assigned to one of three groups (10 males/group): (1) fentanyl (incision+fentanyl), (2) saline (incision+0.9% saline), and (3) unoperated (unoperated sham). Pups with a plantar paw incision received repetitive subcutaneous injections of fentanyl or vehicle through postnatal days (PNDs) 6 to 8. A nonoperated sham group served as nonstressed control. Studies included assessment of development from PND 6 to PND 21 (growth indices and behavioral testing). Fentanyl administered twice daily for three days after surgical incision had no impact on early growth and development, as measured on PND 9, but showed a lasting impact on later growth, enhanced behavioral development, and lower anxiety, as measured through PNDs 10–21. While this does not completely support a benefit from such treatment, our findings may contribute to support the neonatal use of fentanyl, when indicated, even in premature newborns.

Protective perioperative strategy using a third generation hydroxyethyl starch during surgery in a murine model of liver reperfusion injury

PURPOSE To investigate whether a third generation colloid, hydroxyethyl starch (HES 130/0.4), used for perioperative fluid therapy, protects the rat liver against the late-phase response of ischemia/reperfusion injury (IRI) and if inhibition of neutrophil hepatic infiltration plays a part in this mechanism. METHODS Wistar rats were used (8 in each group). Three groups had IRI induced by lobar vascular occlusion (60 minutes) and reperfusion (24 hours) and received HES (13 mL/kg iv), 7.5% saline (HS) (13 mL/kg iv) or no fluid. Three other groups were sham-operated and received the same fluid as the test groups. After 24 hours of reperfusion, blood was drawn for alanine aminotransferase (ALT) quantification and ischemic liver samples were taken for histological study (hematoxylin and eosin and chloroacetate staining of neutrophils). RESULTS HES treatment attenuated the elevation in serum ALT (P=0.001) and reduced the extent of hepatocellular necrosis (P<0.01) compared with the IRI controls. HES-mediated cytoprotection was associated with a decrease of infiltration of neutrophils in the necrotic areas (P<0.05) compared with the untreated IRI rats, but not with the volume control IRI rats (P>0.05). CONCLUSION Hydroxyethyl starch suppresses inflammatory response and ameliorates the late-phase response of hepatic ischemia/reperfusion injury.

Congenital Shunts of the Portal Venous System: Case-series of Uncommon Shunts

BACKGROUND AND AIMS Congenital shunts of the portal venous system are rare entities that can present in children with clinical heterogeneity. To evaluate the clinical course of children with uncommon shunts presenting to our institution and examine the available literature on this topic. Medical records of children with rare forms of congenital shunts were retrospectively reviewed for demographics, symptoms, management, and outcome between 2003 and 2016. RESULTS Three female patients with congenital shunts, including a congenital mesenterico-portal Rex shunt (n = 1) and congenital portosystemic shunts (CPSS) (n = 2), were referred for surgical evaluation between ages 4 and 9. Median follow-up was 8 years (range, 6-13 years). One asymptomatic patient did not require treatment and remained disease-free during long-term follow-up. The other 2 patients with CPSS and unusual symptoms, including liver focal nodular hyperplasia (FNH) in infancy (n = 1) and bleeding from esophageal varices (n = 1), showed subsequent progression to liver nodules that were managed by endovascular shunt occlusion. One patient showed symptom resolution and the other showed stable lesions at last follow-up. Literature yielded descriptions of two cases of congenital mesenterico-portal Rex shunt, one case of coincident CPSS and FNH in infancy, but zero reports of bleeding from esophageal varices. CONCLUSIONS This case series examines each distinct patients presentation, discusses the diagnosis, management and outcome and compares findings while discussing literature on this topic. A high index of suspicion and familiarity with unusual forms and treatment options is required to allow timely diagnosis and appropriate treatment.BACKGROUND AND AIMS Congenital shunts of the portal venous system are rare entities that can present in children with clinical heterogeneity. To evaluate the clinical course of children with uncommon shunts presenting to our institution and examine the available literature on this topic. Medical records of children with rare forms of congenital shunts were retrospectively reviewed for demographics, symptoms, management, and outcome between 2003 and 2016. RESULTS Three female patients with congenital shunts, including a congenital mesenterico-portal Rex shunt (n = 1) and congenital portosystemic shunts (CPSS) (n = 2), were referred for surgical evaluation between ages 4 and 9. Median follow-up was 8 years (range, 6-13 years). One asymptomatic patient did not require treatment and remained disease-free during long-term follow-up. The other 2 patients with CPSS and unusual symptoms, including liver focal nodular hyperplasia (FNH) in infancy (n = 1) and bleeding from esophageal varices (n = 1), showed subsequent progression to liver nodules that were managed by endovascular shunt occlusion. One patient showed symptom resolution and the other showed stable lesions at last follow-up. Literature yielded descriptions of two cases of congenital mesenterico-portal Rex shunt, one case of coincident CPSS and FNH in infancy, but zero reports of bleeding from esophageal varices. CONCLUSIONS This case series examines each distinct patients presentation, discusses the diagnosis, management and outcome and compares findings while discussing literature on this topic. A high index of suspicion and familiarity with unusual forms and treatment options is required to allow timely diagnosis and appropriate treatment.

A Rat Model for the Study of Intestinal Heterotopic Gastropathy

This study analyzes an experimental model for the study of reactions from gastric tissue exposed to enteric environment. Morphological studies were performed by histological, histochemical and immunohistochemical methods, using formalin-fixed biopsies of full-wall-thickness gastric implants in a whole-wall jejunal defect. These grafts suffered severe lesions, characterized by chronic atrophic gastritis, foveolar hyperplasia, glandular cystic transformation, and intestinal metaplasia. Increase in acidic mucins was also observed. There was no proliferating cell nuclear antigen (PCNA) overexpression. The results suggest that this model can be useful to investigate the heterotopic grastropathy and can be applied in further research studies.