Operative indications in recurrent ileocolic intussusception.

BACKGROUND: Air-contrast enema (ACE) is standard treatment for primary ileocolic intussusception. Management of recurrences is less clear. This study aimed to delineate appropriate therapy by quantifying the relationship between recurrence and need for bowel resection, pathologic lead points (PLP), and complication rates. METHODS: After IRB approval, a single institution review of patients with ileocolic intussusception from 1997 to 2013 was performed, noting recurrences, outcomes, and complications. Fisher's exact and t-tests were used. RESULTS: Of 716 intussusceptions, 666 were ileocecal. Forty-four underwent bowel resection, with 29 PLPs and 9 ischemia/perforation. Recurrence after ACE occurred in 96 (14%). Recurrence did not predict PLP (P=0.25). Recurrence (≥3) was associated with higher resection rate (P=0.03), but not ischemia/perforation (P=0.75). ACE-related complications occurred in 4 (0.5%) patients. Successful initial ACE had 98% negative predictive value for resection and PLP (e.g., after successful ACE, 2% had resections, 2% PLP). After failed initial ACE, 36% received resection, and 23% had PLP (P<0.001). CONCLUSIONS: Recurrence is associated with a greater risk of resection but not PLP or ACE-complication. Failed ACE is associated with increased risk for harboring PLP and receiving resection. ACE should be the standard treatment in recurrent intussusception, regardless of number of recurrences.

Predictive value of the Pediatric Ulcerative Colitis Activity Index in the surgical management of ulcerative colitis.

PURPOSE: The primary purpose of this study was to investigate the relationship between Pediatric Ulcerative Colitis Activity Index (PUCAI) and operative management. We also specifically evaluated those patients receiving tacrolimus for their disease. METHODS: A retrospective review (1/06-1/11) identified ulcerative colitis patients (≤21 years old) undergoing restorative proctocolectomy with rectal mucosectomy and ileal pouch-anal anastomosis. Main outcomes included pre-operative PUCAI, combined versus staged procedure, and postoperative complications. Patients receiving tacrolimus within 3 months of surgical intervention were identified. PUCAI at tacrolimus induction and medication side effects were also noted. RESULTS: Sixty patients were identified. Forty-two (70%) underwent combined and 18 (30%) had staged procedures. Pre-operative PUCAI was lower for combined versus staged patients (p = < 0.001). Furthermore, a higher pre-operative PUCAI strongly correlated with the likelihood of undergoing a staged procedure (p < 0.001). Forty-four patients (73%) received tacrolimus. Significant improvement in their PUCAI was noted from induction to pre-operative evaluation (p < 0.001). Minor and reversible side effects occurred in 46% of patients receiving tacrolimus, but complication rates were not significantly different. CONCLUSIONS: There is a very strong correlation between the PUCAI and the likelihood of undergoing a staged procedure. A significant improvement in PUCAI occurs following preoperative tacrolimus therapy.

Intra-amniotic delivery of amniotic-derived neural stem cells in a syngeneic model of spina bifida.

OBJECTIVE: Neural stem cells (NSCs) may promote spinal cord repair in fetuses with experimental spina bifida. We sought to determine the fate of amniotic-derived NSCs (aNSCs) after simple intra-amniotic injection in a syngeneic model of spina bifida. METHODS: Fetal neural tube defects were induced on 20 pregnant Lewis dams by prenatal administration of retinoic acid. Ten dams served as amniotic fluid donors for epigenetic isolation of aNSCs, which were expanded and labeled with 5-bromo-2'-deoxyuridine. The remaining 10 dams received intra-amniotic injections of the processed aNSCs, blindly in all their fetuses (n = 37) on gestational day 17 (term = E21-22). Fetuses with spina bifida underwent screening for the presence of donor aNSCs in the spinal cord at term. RESULTS: Donor cells were identified in 93.3% of the animals with spina bifida, selectively populating the neural placode, typically in clusters, retaining an undifferentiated morphology, and predominantly on exposed neural surfaces, though some were detected deeper in neighboring neural tissue. CONCLUSIONS: The amniotic cavity can serve as a route of administration of NSCs in experimental spina bifida. Simple intra-amniotic delivery of NSCs may be a practical adjuvant to regenerative strategies for the treatment of spina bifida.

Pediatric postoperative intussusception in the minimally invasive surgery era: a 13-year, single center experience.

BACKGROUND: Postoperative intussusception (POI) is a sporadic complication whose mechanisms and risk factors remain poorly understood. Its epidemiology in the minimally invasive surgery era has yet to be well described, particularly in children. We sought to examine risk factors, demographics, and anatomic patterns of pediatric POI in recent years. STUDY DESIGN: This was a 13-year retrospective review from a single tertiary pediatric center. Variables analyzed included patient demographics, time of occurrence, type of intussusception, type of anesthesia, and triggering surgical procedure. The latter variable was divided into 2 groups: abdominal and nonabdominal interventions. Statistical analysis was by 2-tailed Fisher's exact test with significance set at p < 0.05. RESULTS: Among 822 cases of intussusception in 718 patients, 22 documented cases of POI were identified. Twelve of them occurred after abdominal procedures; there was a statistically significant difference in the incidence of POI after open surgery (0.091%; 11 of 12,126) when compared with minimally invasive interventions (0.013%; 1 of 7,610; p = 0.036). As expected, ileoileal and jejunojejunal intussusceptions were the most common forms of POI after abdominal operations (12 of 12; 100%); however, ileocolic intussusceptions were common forms of POI after nonabdominal cases (5 of 10; 50%; p = 0.01). Epidural anesthesia did not appear to be a risk factor for POI. CONCLUSIONS: Although rare, postoperative intussusception can occur after a multitude of interventions, including those performed at a distance from the abdomen. Although small bowel intussusception is the predominant variant of this complication after abdominal procedures, ileocolic intussusception is prevalent after other interventions. Minimally invasive abdominal access may protect against postoperative intussusception in children.

The amniotic fluid as a source of neural stem cells in the setting of experimental neural tube defects.

We sought to determine whether neural stem cells (NSCs) can be isolated from the amniotic fluid in the setting of neural tube defects (NTDs), as a prerequisite for eventual autologous perinatal therapies. Pregnant Sprague-Dawley dams (n=62) were divided into experimental (n=42) and control (n=20) groups, depending on prenatal exposure to retinoic acid for the induction of fetal NTDs. Animals were killed before term for analysis (n=685 fetuses). Amniotic fluid samples from both groups underwent epigenetic selection for NSCs, followed by exposure to neural differentiation media. Representative cell samples underwent multiple morphological and phenotypical analyses at different time points. No control fetus (n=267) had any structural abnormality, whereas at least one type of NTD developed in 52% (217/418) of the experimental fetuses (namely, isolated spina bifida, n=144; isolated exencephaly, n=24; or a combination of the two, n=49). Only amniotic samples from fetuses with a NTD yielded cells with typical neural progenitor morphology and robust expression of both Nestin and Sox-2, primary markers of NSCs. These cells responded to differentiation media by displaying typical morphological changes, along with expression of beta-tubulin III, glial fibrillary acidic protein, and/or O4, markers for immature neurons, astrocytes, and oligodendrocytes, respectively. This was concurrent with downregulation of Nestin and Sox-2. We conclude that the amniotic fluid can harbor disease-specific stem cells, for example, NSCs in the setting of experimental NTDs. The amniotic fluid may be a practical source of autologous NSCs applicable to novel forms of therapies for spina bifida.

Association between major perioperative hemorrhage and stroke or Q-wave myocardial infarction.

BACKGROUND: Hemorrhage is associated with ischemic complications in cardiac patients. The nature of this relationship in surgical patients is unknown. METHODS AND RESULTS: We examined the association between major perioperative hemorrhage and stroke or myocardial infarction among adults who underwent surgery from 2005 through 2009 at centers participating in the National Surgical Quality Improvement Program. We excluded patients with emergent, trauma-related, transplantation, cardiac, or neurological operations. Major hemorrhage was defined as bleeding necessitating transfusion of >4 U of packed red blood cells or whole blood. Stroke was defined as focal brain dysfunction lasting ≥24 hours from a vascular cause. A diagnosis of myocardial infarction required new ECG Q waves. Outcomes were assessed from surgery until 30 days afterward. Among 651,775 patients who underwent surgery, 5233 (0.80%) experienced major hemorrhage, 1575 (0.24%) developed Q-wave myocardial infarction, and 1321 (0.20%) suffered a stroke. In Cox proportional hazards analyses controlling for vascular risk factors, illness severity, and type of surgery, hemorrhage was independently associated with subsequent stroke (hazard ratio, 2.5; 95% confidence interval, 1.9-3.3) and subsequent Q-wave myocardial infarction (hazard ratio, 2.7; 95% confidence interval, 2.1-3.4). Interaction terms revealed no significant variation in these associations by age, sex, or type of surgery. Our results were robust across multiple sensitivity analyses. CONCLUSIONS: Major perioperative hemorrhage is associated with subsequent stroke and myocardial infarction in patients undergoing noncardiac, nonneurological surgery. This suggests the need for randomized trials to guide perioperative use of antiplatelet drugs, which affect the risk of both bleeding and vascular events.

Prenatal tracheal reconstruction with a hybrid amniotic mesenchymal stem cells-engineered construct derived from decellularized airway.

PURPOSE: This study was aimed at examining an airway construct engineered from autologous amniotic mesenchymal stem cells (aMSCs) and a xenologous decellularized airway scaffold as a means for tracheal repair. METHODS: Fetal lambs (N = 13) with a tracheal defect were divided into 2 groups. One group (acellular, n = 6) was repaired with a decellularized leporine tracheal segment. The other group (engineered, n = 7) received an identical graft seeded with expanded/labeled autologous aMSCs. Newborns were euthanized for multiple analyses. RESULTS: Eleven lambs survived to term, 10 of which could breathe at birth. Engineered grafts showed a significant increase in diameter in vivo (P = .04) unlike acellular grafts (P = .62), although variable stenosis was present in all implants. Engineered constructs exhibited full epithelialization, compared with none of the acellular grafts (P = .002). Engineered grafts had a significantly greater degree of increase in elastin levels after implantation than acellular implants (P = .04). No such differences were noted in collagen and glycosaminoglycan contents. Donor cells were detected in engineered grafts, which displayed a pseudostratified columnar epithelium. CONCLUSIONS: Constructs engineered from aMSCs and decellularized airway undergo enhanced remodeling and epithelialization in vivo when compared with equivalent acellular implants. Amniotic mesenchymal stem cell-engineered airways may become an alternative for perinatal airway repair.

Craniofacial repair with fetal bone grafts engineered from amniotic mesenchymal stem cells.

BACKGROUND: Ethically acceptable applications of fetal tissue engineering as a perinatal therapy can be expanded beyond life-threatening anomalies by amniotic fluid cell-based methods, in which cell procurement poses no additional risk to the mother. We sought to start to determine whether osseous grafts engineered from amniotic mesenchymal stem cells (aMSCs) could be an adjunct to craniofacial repair. METHODS: New Zealand rabbits (n = 12) underwent creation of a full-thickness diploic nasal bone defect. We then equally divided animals into two groups based on how the defect was repaired: namely, size-matched implants of electrospun biodegradable nanofibers with or without nuclear labeled, allogeneic aMSCs maintained in osteogenic medium. We killed animals 8 wk post-implantation for multiple analyses. Statistical analysis included analysis of variance, post-hoc Bonferroni adjusted comparisons, and Levene's F-test, as appropriate (P < 0.05), with significance set at P < 0.05. RESULTS: Micro-computed tomography scanning (two- and three-dimensional) showed no significant differences in defect radiodensity between groups. However, extracellular calcium levels were significantly higher in engineered grafts than in acellular implants (P = 0.003). There was significantly greater variability in mineralization in acellular implants than in engineered grafts by both direct calcium (P = 0.008) and micro-computed tomography measurements (P = 0.032). There were no significant differences in alkaline phosphatase activity or variance between groups. We documented labeled cells in the engineered grafts. CONCLUSIONS: Craniofacial repair with osseous grafts engineered from aMSCs lead to enhanced and more consistent mineralization compared with an equivalent acellular prosthetic repair. Amniotic fluid-derived engineered bone may become a practical adjunct to perinatal craniofacial reconstruction.

Adrenal cortical tumors in children: factors associated with poor outcome.

PURPOSE: The purpose of this study was to evaluate recurrence and survival outcomes in pediatric adrenal cortical neoplasms. METHODS: A 90-year retrospective review of children with adrenal cortical neoplasms was performed using multivariate Cox regression analysis to identify factors associated with recurrence and tumor-related mortality. RESULTS: The evaluable cohort included 29 patients. Twenty-seven underwent resection. Twenty-two (81%) had localized disease, and 5 (19%) had locally advanced disease (all received chemotherapy and 2 of 5 were cured). Two patients presenting with metastatic disease died despite treatment. There were 4 recurrences; all patients died. Tumor-related mortality was 24% (7/29). Kaplan-Meier freedom from recurrence was 85% at 1 year (95% confidence interval, 75%-95%). Multivariate Cox regression revealed that older age (P = .01), higher mitotic rate (P = .005), and necrosis (P < .001) were independent predictors of tumor-related death. Higher mitotic rate (P = .007) and larger tumor size (P = .03) were significant predictors of tumor recurrence. CONCLUSION: Risk factors for poor outcomes in patients with adrenocortical tumors include older age, higher mitotic rate, higher percent necrosis, and larger tumor size. Therefore, the presence of these factors may warrant consideration of adjuvant chemotherapy, even in the absence of advanced disease.

Damage control operation for massive sacrococcygeal teratoma.

Surgical resections of massive sacrococcygeal teratomas (SCTs) carry significant risk due to baseline hemodynamic instability and the potential for significant hemorrhage. In this case report, a fetus with sacrococcygeal teratoma developed high-output cardiac instability at 32 weeks' gestation. After urgent cesarian delivery, a damage-control operation using Teflon-pledgeted mattress sutures allowed for hemodynamic control of bleeding into the tumor. One week later, after subsequent fluid resuscitation and stabilization, an elective staged resection of the complete mass including the pelvic portion was performed. The patient was discharged home on postoperative day 30 and was doing well at her most recent clinic visit at 30 months of age.

Familial case of prenatally diagnosed intralobar and extralobar sequestrations with cystadenomatoid change.

Hybrid lesions are part of a spectrum of rare pulmonary diseases that are characterized as having elements of both congenital pulmonary airway malformation and bronchopulmonary sequestration. Fetal thoracic masses arise from alterations during lung development that are separated by timing of the inciting event and are often associated with an underlying degree of bronchial atresia. There are a handful of documented reports of sequestrations occurring in siblings, but no known reports of prenatally diagnosed lesions occurring in families. We present a case of 2 siblings diagnosed prenatally with fetal thoracic lesions who underwent postnatal resection revealing hybrid lesions on pathologic examination. Newer radiologic techniques have increased our ability to detect these masses prenatally, as well as follow them throughout pregnancy to determine their natural history. Ongoing laboratory investigation into the etiology of congenital lung lesions has brought forth more questions and suggested a familial component at a cellular level that has not yet been fully discovered. We reviewed the current literature of factors contributing to the development of congenital lung lesions and suggest that there is a familial link in certain patient populations where screening may be indicated.

Preclinical regulatory validation of an engineered diaphragmatic tendon made with amniotic mesenchymal stem cells.

PURPOSE: Under a Food and Drug Administration directive, we examined definite long-term safety and efficacy aspects of an engineered diaphragmatic tendon graft as a regulatory prerequisite for clinical trials. METHODS: Newborn lambs (N = 27) underwent partial diaphragmatic replacement with a Teflon patch, a composite acellular bioprosthesis, or the same bioprosthesis seeded with autologous amniotic mesenchymal stem cells processed under Good Manufacturing Practice guidelines. Multiple safety and efficacy analyses were performed at different time points up to 14 months of age (ovine adulthood). RESULTS: There was no mortality. None of the blood tests or full body autopsy specimens showed any abnormality. There was a significantly higher failure rate in animals that received an acellular bioprosthetic graft vs an engineered graft, with no significant differences between Teflon and acellular bioprosthetic implants. Tensile strength and total collagen levels were significantly higher in engineered grafts than in acellular bioprosthetic grafts. On histology, lysozyme and myeloperoxidase stainings were unremarkable in all grafts. CONCLUSIONS: Diaphragmatic repair with a clinically viable autologous tendon engineered with amniotic mesenchymal stem cells leads to improved outcomes when compared with an equivalent acellular bioprosthesis, with no local or systemic adverse effects. Clinical trials of engineered diaphragmatic repair appear practicable within regulatory guidelines.

Serial amnioinfusions prevent fetal pulmonary hypoplasia in a large animal model of oligohydramnios.

BACKGROUND/PURPOSE: Severe neonatal pulmonary hypoplasia incurs mortality rates approaching 71% to 95%. We sought to determine the utility of serial amnioinfusions through a subcutaneously implanted intraamniotic catheter to prevent pulmonary hypoplasia in fetal obstructive uropathy. METHODS: Fetal lambs (n = 32) were divided into 3 groups. Group I (n = 12) underwent a sham operation, group II (n = 15) underwent a complete urinary tract obstruction via ligation of the urachus and urethra with a subcutaneous tunneled intraamniotic port-a-cath without amnioinfusions, and group III (n = 5) underwent a creation of a complete urinary tract obstruction with a port-a-cath as described in group II with serial amnioinfusions. Lung tissue was analyzed by lung volume to body weight ratios and stereology. Statistical analysis was performed by analysis of variance and Bonferroni comparisons (P < .05). RESULTS: Obstructed fetuses grossly had smaller lungs than treated and control animals. Lung volume to body weight ratios were statistically significant between groups. Airspace fractions were comparable between groups I and III (average = 0.53 and 0.55, respectively), although both were significantly greater than group II (average = 0.48) (P = .049). CONCLUSIONS: Serial amnioinfusions through an intraamniotic port-a-cath prevented pulmonary hypoplasia in an ovine model of complete obstructive uropathy. The use of an easily accessible device for amnioinfusions may be a viable option to treat oligohydramnios.

Amniotic mesenchymal stem cells enhance normal fetal wound healing.

Fetal wound healing involves minimal inflammation and limited scarring. Its mechanisms, which remain to be fully elucidated, hold valuable clues for wound healing modulation and the development of regenerative strategies. We sought to determine whether fetal wound healing includes a hitherto unrecognized cellular component. Two sets of fetal lambs underwent consecutive experiments at midgestation. First, fetuses received an intra-amniotic infusion of labeled autologous amniotic mesenchymal stem cells (aMSCs), in parallel to different surgical manipulations. Subsequently, fetuses underwent creation of 2 symmetrical, size-matched skin wounds, both encased by a titanium chamber. One of the chambers was left open and the other covered with a semipermeable membrane that allowed for passage of water and all molecules, but not any cells. Survivors from both experiments had their wounds analyzed at different time points before term. Labeled aMSCs were documented in all concurrent surgical wounds. Covered wounds showed a significantly slower healing rate than open wounds. Paired comparisons indicated significantly lower elastin levels in covered wounds at the mid time points, with no significant differences in collagen levels. No significant changes in hyaluronic acid levels were detected between the wound types. Immunohistochemistry for substance P was positive in both open and covered wounds. We conclude that fetal wound healing encompasses an autologous yet exogenous cellular component in naturally occurring aMSCs. Although seemingly not absolutely essential to the healing process, amniotic cells expedite wound closure and enhance its extracellular matrix profile. Further scrutiny into translational implications of this finding is warranted.

A large animal model of the fetal tracheal stenosis/atresia spectrum.

BACKGROUND: Treatment of congenital tracheal stenosis/atresia remains essentially unresolved. Previous models of this disease entity have been restricted to rodents and the chick. We sought to establish the principles of a large, surgical animal model of this spectrum of fetal anomalies. METHODS: Fetal lambs (n = 8) underwent open surgery at 90-112 days gestation. Their cervical tracheas were encircled by a biocompatible polytetrafluoroethylene wrap, so as to extrinsically restrict their external diameter by 25%. Survivors (n = 7) were killed at different time points post-operatively before term. The manipulated tracheal segments were compared with their respective proximal portions (controls). Analyses included morphometry, histology and quantitative extracellular matrix measurements. RESULTS: At necropsy, the typical gross appearance of tracheal stenosis/atresia was present in all manipulated tracheal segments. Histological findings included the virtual disappearance of the membranous portion of the trachea, along with infolding, fragmentation, and/or posterior fusion of cartilaginous rings, often with disappearance of the airway mucosa. There were significant decreases in diameter (P < 0.001) and total collagen levels (P = 0.005) on the manipulated trachea compared with the control portions. No significant differences were observed in overall elastin or glycosaminoglycan contents. A significant time-dependent increase in elastin was noted on the control, but not the experimental side. CONCLUSIONS: In a surgical ovine model, controlled extrinsic compression of the fetal trachea leads to morphological and biochemical findings compatible with the congenital tracheal stenosis/atresia spectrum. This simple and easily reproducible prenatal model can be instrumental in the development of emerging therapies for these congenital anomalies.

Chest wall repair with engineered fetal bone grafts: an efficacy analysis in an autologous leporine model.

PURPOSE: We sought to compare the efficacy of engineered fetal bone grafts with acellular constructs in an autologous model of chest wall repair. METHODS: Rabbits (n = 10) with a full-thickness sternal defect were equally divided in 2 groups based on how the defect was repaired, namely, either with an autologous bone construct engineered with amniotic mesenchymal stem cells on a nanofibrous scaffold or a size-matched identical scaffold with no cells. Animals were killed at comparable time-points 18 to 20 weeks postimplantation for multiple analyses. RESULTS: Gross evidence of nonunion confirmed by micro-computed tomography scanning was present in 3 (60%) of 5 of the acellular implants but in no engineered grafts. Histology confirmed the presence of bone in both types of repair, albeit seemingly less robust in the acellular grafts. Mineral density in vivo was significantly higher in engineered grafts than in acellular ones, with more variability among the latter. There was no difference in alkaline phosphatase activity between the groups. CONCLUSIONS: Chest wall repair with an autologous osseous graft engineered with amniotic mesenchymal stem cells leads to improved and more consistent outcomes in the midterm when compared with an equivalent acellular prosthetic repair in a leporine model. Amniotic fluid-derived engineered bone may become a practical alternative for perinatal chest wall reconstruction.

Cardiac anomalies in the fetus.

Congenital heart disease (CHD) is an attractive target for fetal therapy. With the development of successful neonatal repair for many types of CHD over the last 20 years, fetal therapy has become the next frontier. Concurrent advances in interventional catheterization and fetal imaging provided a foundation for the novel field of fetal cardiac intervention. This article focuses on the current status of in utero catheter interventions for CHD with particular interest in therapy for defects characterized by progressive stenosis or atresia of the semilunar valves, the aortic and pulmonary, with development of subsequent ventricular hypoplasia.

Fetal tissue engineering.

Attempts at harnessing the prospective benefits of the therapeutic use of fetal cells or tissues date many decades before the modern era of transplantation. The first reported transplantation of human fetal tissue took place in 1922. Fetal cells or tissues also have been used as helpful investigational tools since the 1930s. Still, it was only in the last three decades that fetal tissue transplantation in people has started to lead to favorable outcomes, yet by and large anecdotally. This article offers an outlook on a relatively new dimension in fetal cell-based therapies, namely the engineering of tissues in the laboratory, along with its prospective applications.