A new rat model of prenatal bowel obstruction: development and early assessment

Purpose

Although intestinal motility disorders often complicate the postoperative surgical management of newborns with congenital intestinal atresia, their pathogenesis remains unclear. Animal models of prenatal intestinal obstruction have been mainly developed in the lamb and the chicken. Despite new insights brought by these models, they have one or more limitations, such as high fetal mortality rates, high costs, long gestation periods, and an insufficient number of fetuses per litter. Moreover, some species are phylogenetically distant from mammals.

Methods

We developed a reproducible model of prenatal intestinal obstruction in the rat to study the histologic changes induced by the obstruction. We report, the technical devices and the first assessment of this atresia model in a didactic way to allow other researchers to easily reproduce the model.

Results

Prenatal intestinal obstructions in this study fulfilled all the macroscopic and histologic criteria usually listed by other models of prenatal intestinal obstruction that have been developed in other species. Furthermore with our model, we obtained a high success rate at a low cost.

Conclusions

We presented in this study a reproducible model of prenatal intestinal obstruction in the rat with the macroscopical and histologic features of prenatal intestinal obstruction.     

Placental vascular compromise in jejunoileal atresia

Background/Purpose

The mechanisms of intrauterine vascular disruptions that result in the development of jejunoileal atresia (JIA) are not fully understood. Monochorionic twinning with fetal death of a cotwin is known to be correlated with the development of JIA in the survivor through placental communication. The aim of this study was to evaluate whether other placental vascular compromises might contribute to the development of JIA.

Methods

Forty-five newborns (23 boys and 22 girls) who were treated for JIA at Tsukuba University Hospital from 1978 to 2003 were reviewed. Placental findings were informative in 23 cases.

Results

No or slight abnormality of the placenta was found in 19 cases. Significant placental abnormalities were found in 4 patients who also had a low birth weight. One patient with apple peel atresia (APA) had excessive torsion of the umbilical cord (UC), which was inserted at the margin of the placenta, and there was an adjacent area of infarction. One patent with multiple atresia (MA) was a surviving monochorionic twin with intrauterine fetal death of the other. Another case of MA showed marginal insertion of the UC. Severe placental abnormalities including wide infarction, cyst formation, and marginal insertion of the UC were found in 1 case of MA. These 3 cases of MA were complicated with other anomalies including brain anomaly.

Conclusions

Placental vascular compromises were involved infrequently in JIA but might possibly be responsible for the development of JIA as well as associated anomalies and a low birth weight as chronic insults since an early stage of gestation in some cases.     

A new variant of type III jejunoileal atresia

Jejunoileal atresia (JIA) is a congenital defect that can result in significant loss of bowel length. The traditional classification of JIA was first proposed by Grosfeld and includes 4 subtypes. Among these, type IIIB, or apple-peel atresia, is characterized by a proximal atretic jejunum and a distal segment of spiraled bowel that terminates at the cecum. Owing to this anatomy, patients with type IIIB JIA are at increased risk for short bowel syndrome and intestinal failure. In this report, we described the case of a neonate with a prenatal diagnosis of JIA. At exploration, she was initially found to have a type IIIB atresia. However, instead of terminating at the cecum, the distal spiraled segment was followed by 75 cm of normal small bowel and mesentery. Surgical correction proceeded with minimal resection and primary anastomosis. She recovered well from this procedure, tolerated full enteral nutrition by mouth, and displayed good weight gain at outpatient follow-up. Owing to the unique anatomy of the gastrointestinal tract in this case report, we propose the addition of a new class of JIA, type IIIC, to better reflect its prognostication and surgical management.     

A proposed classification system for familial intestinal atresia and its relevance to the understanding of the etiology of jejunoileal atresia

Familial cases of the various types of intestinal atresia are well described, and we now report an additional family. Based on a review of the literature, a classification system for the different types of familial atresia is presented. Current teaching attributes most jejunoileal atresias to in utero vascular accidents occurring relatively late in gestation (after the 11th or 12th week). Although some cases clearly occur this way, as a result of processes such as volvulus and intussusception, knowledge of the familial form of the disease indicates that most cases of jejunoileal atresia actually result from disruption of a normal embryologic pathway, most likely the development of the superior mesenteric artery and its branches. They should be considered to be true embryologic malformations rather than acquired lesions.     

Serial transverse enteroplasty in intestinal atresia management

In intestinal atresia, resection of the proximal dilated bowel segment, if long, might lead to bowel length compromise. Although tapering enteroplasty and plication are well described to avoid such a resection, the use of serial transverse enteroplasty is proposed here as an alternative in this situation.     

Different types of intestinal atresia in identical twins

The authors present a previously unreported association of different types of intestinal atresia in identical low-birth-weight twins. Both babies were affected by duodenal atresia, associated in the first case with a complete mucosal duodenal membrane and in the second one with an “apple-peel” jejunal atresia. These occurrences may suggest that they were either the consequence of linkage of 2 genes or a pleiotropic expression of a single gene responsible for such rare conditions.     

The etiologic role of intrauterine volvulus and intussusception in jejunoileal atresia

Purpose

Although intussusception has been reported as quite a rare cause of jejunoileal atresia (JIA), pediatric surgeons have noted the frequent presence of intussusception as well as volvulus at surgery. The aim of this study was to investigate the contribution of intrauterine intussusception and volvulus to the development of JIA.

Methods

In 48 newborns (24 boys and 24 girls) treated for JIA at our hospital between 1978 and 2004, the operative and pathologic findings were reviewed.

Results

Intussusception was responsible for gap and cord type atresia in 12 cases (25%). The cord showed an atrophic intestinal lumen in 2 cases. Volvulus was observed in 13 cases. Volvulus and intussusception were simultaneously noted in 1 case. This suggested that intussusception was the cause of the atresia, whereas volvulus was a secondary event. Neither intussusception nor volvulus was observed in high jejunal, apple peel, or multiple atresia.

Conclusions

Intrauterine volvulus and intussusception were commonly observed in single mid- and low JIA. Thus, intrauterine intussusception may be a common cause of gap and cord type JIA. Volvulus may not only cause JIA but also result from anatomic changes after the development of JIA in some cases.     

Mainstem bronchial atresia: a lethal anomaly amenable to fetal surgical treatment

Purpose

The purpose of this study was to review the unique imaging characteristics, prenatal course, and outcomes for fetuses with mainstem bronchial atresia (MBA).

Methods

The records of all patients referred for a fetal lung malformation from 2001 to 2012 and the medical literature were reviewed to identify cases of MBA.

Results

Of 129 fetuses evaluated, 3 were diagnosed prenatally with right-sided MBA. The first had a CCAM-volume ratio (CVR) of 9, hydrops, mirror syndrome, and preterm delivery of a nonviable fetus. The second (CVR 2.6) had ascites, preterm delivery at 34-weeks, and neonatal demise. The third fetus (CVR 5.7) presented with hydrops at 21-weeks, prompting fetal pneumonectomy. Postoperatively, hydrops resolved, and the contralateral lung grew dramatically, but preterm delivery occurred 3 weeks later. Ventilation could not be sustained, and the infant died. Four similar cases of MBA were in the literature, all right-sided. Two fetuses with hydrops delivered at 25-weeks and died immediately. One pregnancy was terminated. One fetus underwent pneumonectomy at 24-weeks but died intraoperatively.

Conclusion

MBA is a rare and lethal lesion that must be distinguished from other right-sided lung masses. Fetal pneumonectomy can be performed with resolution of hydrops and compensatory contralateral lung growth, but remains limited by complications of preterm birth.     

Multiple jejunoileal atresia and colonic atresia managed by multiple primary anastomosis with a single gastroperineal transanastomotic tube without stomas

Multiple jejunoileal atresia is a challenge to the pediatric surgeon. The aim of the study is to preserve bowel length and prevent the long-term complications of short bowel syndrome. The authors present a rare case of combined multiple jejunoileal atresia and colonic atresia managed by 9 primary anastomoses over a gastroperineal transanastomotic tube. This technique avoided the use of stomas and their attendant complications.     

In utero diagnosis of congenital pyloric atresia in a single twin using MRI and ultrasound

Congenital pyloric atresia (CPA) is a rare disorder that has traditionally been diagnosed in the postnatal period. With improvements in ultrasound technology and increasing use of MRI, CPA is now diagnosed with increasing accuracy in utero. This also allows for identification of concomitant anomalies, which greatly affects infant survival. In addition, antenatal diagnosis of CPA and associated anomalies allow for family counseling and planning of treatment for the perinatal period including early referral to a center with pediatric surgical services. Here, we present a case of CPA with preoperative diagnosis using ultrasound and MRI.     

Intestinal atresia and agenesis of the gallbladder in 2 siblings

Intestinal atresia and gallbladder agenesis are rare congenital malformations usually presenting as isolated and sporadic. We present and discuss the case of 2 sisters affected by a previously unreported association of these 2 anomalies.     

Fetal repair of surgically-created gastroschisis in a lamb model may improve postnatal feeding tolerance and intestinal motility: A pilot study

BackgroundGastroschisis remains a morbid and costly congenital defect, predominantly owing to sequelae of intestinal dysmotility and malabsorption. Although fetal surgical repair has been demonstrated in a lamb model, it is unclear whether this improves intestinal motility and feeding tolerance.MethodsFetuses from five time-mated ewes (Ovis aries) underwent defect creation at gestational age (GA) 76–80 days. The experimental group underwent in utero repair of gastroschisis at GA 99–100. The positive control group underwent postnatal repair of at time of cesarean section at GA 139–141. On day of birth, lambs were fed barium sulfate, followed by ad lib colostrum/milk. Lambs were monitored for up to 72 h to determine feeding tolerance and duration of time for complete passage of barium through the gastrointestinal tract.ResultsEight fetuses underwent gastroschisis defect creation and five survived to birth. Of the three lambs repaired at birth, one required resection of necrotic bowel and two had significant intestinal stricture at the abdominal wall defect and did not tolerate feeding. Of the two lambs repaired in utero, one tolerated feeding normally without complications and one had a small intestine atresia preventing normal feeding.ConclusionFetal repair of gastroschisis may improve postnatal intestinal motility resulting in feeding tolerance at birth.Study typeProspective comparative study.Level of evidenceLevel II.     

Impact of corticosteroid on intestinal injury in a gastroschisis rat model: morphometric analysis

Background/Purpose

The goal in the treatment of gastroschisis is to prevent intestinal injury. Corticosteroids are known by their effects at the inflammatory response and by the improvement on the intestinal maturity. The authors evaluated the effects of maternal corticosteroid administration on the intestines of rats that underwent fetal gastroschisis.

Methods

A Correia-Pinto-modified gastroschisis rat model was used. Two groups were assessed: the control group (group 1) and the dexamethasone group (group 2). Each group was composed of control and sham fetuses, and fetuses with gastroschisis. Fetal body weight, intestinal weight, intestinal length, and protein were assessed. Histologic analysis involved measures of intestinal loop diameter, total intestinal wall, mucosa and submucosa, both circular and longitudinal muscle layers, and serosal thicknesses. Differences between groups and subgroups were tested by the analysis of variance method with a significant P value less than .05.

Results

Dexamethasone decreased in all the morphometric data except in the intestinal length. Dexamethasone increased the intestinal protein content in fetuses with gastroschisis, and control and sham fetuses. In both groups, all histologic parameters were increased in fetuses with gastroschisis (P < .0001).

Conclusions

Dexamethasone caused a substantial decrease in intestinal weight in GFs, increased the intestinal protein content, and it may be useful in decreasing the intestinal damage of gastroschisis.     

Minimal access approach to jejunal atresia

Aim

Jejunal atresia (JA) is a common cause of intestinal obstruction in the newborn. It is corrected by small bowel tapering/excision and end-to-end enteroenterostomy, performed through a transverse laparotomy incision. It has excellent result with minimal morbidity and mortality. This incision can be reduced to a circumumbilical type as has been described for hypertrophic pyloric stenosis.

Materials

Sixteen neonates, aged 1 to 8 days, underwent JA repair via this approach over a 3-year period.

Result

The small bowel is easily accessible through this approach in all but 1 case, where a suspected colonic atresia, combined with JA, necessitated an extension to classical incision. Thirteen patients had an uneventful recovery; 2 cases required revision for anastomotic strictures, which was done through the same incision. Postoperative follow-up at 6 months showed well-healed skin incisions that were hardly visible and integrating well with the natural umbilical fold.

Conclusion

Circumumbilical incision permits an adequate approach to correction of JA. It has minimal complications and a superior cosmesis compared to the classical approach.     

Composition of amniotic fluid with experimental jejuno-ileal atresia

The possibility that the composition of amniotic fluid is significantly altered with fetal intestinal obstruction was examined in 15 normal, 15 sham operated and 15 ewes in which jejuno-ileal atresia was created by devascularizing a 15 cm intestinal segment in the fetus at 90–100 days gestation. Samples of amniotic fluid forosmolality, urea N, creatinine, electrolytes, amylase, lipase, bilirubin, and proteins were obtained at 100 days gestation and at C-section performed 5 days prior to the anticipated date of delivery. One sham operated and four operated fetuses aborted prior to term for 83% overall fetal survival rate. All surviving operated animals had total intestinal obstruction with the classical appearance of jejuno-ileal atresia. The volume of amniotic fluid at term varied from gelatinous material to as much as 1.0 liter of clear yellow to dark orange fluid. Amniotic fluid composition in term animals was not significantly different from those at 100 days gestation when the creatinine was below 15 mg%. However, sodium and chloride were significantly elevated in all groups at term when the creatinine was above 15 mg%. The osmolality and urea N in the latter group was not significantly different from animals at 100 days gestation. The amylase, lipase, total proteins, albumin, total and direct, and bilirubin in control animals at term was not significantly different from sham operated and experimental subjects. This study suggests that routine amniocentesis in the “high risk” patient would not be diagnostic of fetal intestinal obstruction.     

腹腔镜与开腹手术治疗新生儿肠闭锁的比较

目的 探讨腹腔镜手术治疗新生儿肠闭锁的疗效。方法将61例新生儿肠闭锁随机分成2组（腹腔镜组31例和开腹组30例），比较两组术中情况和预后。结果两组患儿术后存活率、术后并发症P值分别为0．973、0．862，统计学上无显著差异，但腹腔镜组有20例经脐孔拖出行肠切除、肠吻合手术患儿术后脐正常，疤痕无或很小。结论腹腔镜下治疗新生儿肠闭锁技术简单、安全、几乎无瘢痕。     

Fetal extraperitoneal rectal perforation presenting after duodenal atresia repair

Fetal extraperitoneal rectal perforation (FERP) is a very rare condition, but prompt diagnosis and appropriate treatment produce overall good outcome. We report the first case of FERP known to be associated with duodenal atresia, which only became clinically apparent after duodenal atresia repair and initially presented a diagnostic difficulty. Our case was successfully treated with a defunctioning colostomy and subsequent excision of the pseudocyst cavity. Proximal atresias can mask the presentation of FERP, and this diagnosis should be considered in cases of neonatal perineal and buttock swelling.     

Intrauterine intussusception: a rare cause of intestinal atresia

Intrauterine intussusception is an uncommon cause of intestinal atresia. We report a case of ileal atresia owing to antenatal intussusception revealed as an intraluminal polypoid lesion after surgical intervention.