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1.
J Pediatr Surg ; 59(1): 109-116, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37845124

RESUMEN

PURPOSE: Vocal fold movement impairment (VFMI) secondary to recurrent laryngeal nerve (RLN) injury is a common source of morbidity after pediatric cervical, thoracic, and cardiac procedures. Flexible laryngoscopy (FL) is the gold standard to diagnose VFMI yet can be challenging to perform and/or risks possible clinical decompensation in some children and is an aerosolizing procedure. Laryngeal ultrasound (LUS) is a potential non-invasive alternative, but limited data exists in the pediatric surgical population regarding its efficacy. We aimed to investigate the diagnostic accuracy of LUS compared to FL in evaluating VFMI. METHODS: A prospective, single-center, single-blinded (rater) cohort study was undertaken on perioperative pediatric patients at risk for RLN injury. Patients underwent FL and LUS. Cohen's kappa was used to determine chance-corrected agreement. RESULTS: Between 2021 and 2023, 85 paired evaluations were performed with patients having a median (IQR) age of 10 (4, 42) months and weight of 7.5 (5.4, 13.4) kilograms. The prevalence of VFMI was 27.1%. Absolute agreement between evaluations was 98.8% (kappa 0.97, 95% CI: 0.91-1.00, P < 0.001). The sensitivity and specificity of LUS in detecting VFMI was 95.7% and 100%, yielding a positive predictive value (PPV) of 100% and negative predictive value (NPV) of 98.4% (95% CI: 90-100%). Diagnostic accuracy was 98.8% (95% CI: 93-100%). CONCLUSION: LUS is a highly accurate modality in evaluating VFMI in children. While FL remains the gold standard for diagnosis, LUS offers a low-risk screening modality for children at risk for VFMI such that only those with an abnormal LUS or presence of clinical symptoms discordant with LUS findings should undergo FL. TYPE OF STUDY: Prospective, single-center, single blinded (rater), cohort study. LEVEL OF EVIDENCE: Level II.


Asunto(s)
Parálisis de los Pliegues Vocales , Pliegues Vocales , Humanos , Niño , Lactante , Pliegues Vocales/diagnóstico por imagen , Parálisis de los Pliegues Vocales/diagnóstico por imagen , Parálisis de los Pliegues Vocales/epidemiología , Estudios de Cohortes , Estudios Prospectivos , Ultrasonografía
2.
Laryngoscope ; 133(12): 3564-3570, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-36892035

RESUMEN

INTRODUCTION: Children undergoing cervical and/or thoracic operations are at risk for recurrent laryngeal nerve injury, resulting in vocal fold movement impairment (VFMI). Screening for VFMI is often reserved for symptomatic patients. OBJECTIVE: Identify the prevalence of VFMI in screened preoperative patients prior to an at-risk operation to evaluate the value of screening all patients at-risk for VFMI, regardless of symptoms. METHODS: A single center, retrospective review of all patients undergoing a preoperative flexible nasolaryngoscopy between 2017 and 2021, examining the presence of VFMI and associated symptoms. RESULTS: We evaluated 297 patients with a median (IQR) age of 18 (7.8, 56.3) months and a weight of 11.3 (7.8, 17.7) kilograms. Most had a history of esophageal atresia (EA, 60%), and a prior at-risk cervical or thoracic operation (73%). Overall, 72 (24%) patients presented with VFMI (51% left, 26% right, and 22% bilateral). Of patients with VFMI, 47% did not exhibit the classic symptoms (stridor, dysphonia, and aspiration) of VFMI. Dysphonia was the most prevalent classic VFMI symptom, yet only present in 18 (25%) patients. Patients presenting with a history of at-risk surgery (OR 2.3, 95%CI 1.1, 4.8, p = 0.03), presence of a tracheostomy (OR 3.1, 95%CI 1.0, 10.0, p = 0.04), or presence of a surgical feeding tube (OR 3.1, 95%CI 1.6, 6.2, p = 0.001) were more likely to present with VFMI. CONCLUSION: Routine screening for VFMI should be considered in all at-risk patients, regardless of symptoms or prior operations, particularly in those with a history of an at-risk surgery, presence of tracheostomy, or a surgical feeding tube. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3564-3570, 2023.


Asunto(s)
Disfonía , Parálisis de los Pliegues Vocales , Humanos , Niño , Lactante , Pliegues Vocales/lesiones , Disfonía/diagnóstico , Disfonía/etiología , Disfonía/epidemiología , Parálisis de los Pliegues Vocales/diagnóstico , Parálisis de los Pliegues Vocales/etiología , Parálisis de los Pliegues Vocales/epidemiología , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos
3.
J Pediatr Surg ; 58(4): 613-618, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36646540

RESUMEN

PURPOSE: The purpose of this study was to analyze the management and outcomes of primary button battery ingestions and their sequelae at a single high-volume center, and to propose a risk score to predict the likelihood of a severe outcome. METHODS: The medical record was queried for all patients under 21 years old evaluated at our institution for button battery ingestion from 2008 to 2021. A severe outcome was defined as having at least one of the following: deep/circumferential mucosal erosion, perforation, mediastinitis, vascular or airway injury/fistula, or development of esophageal stricture. From a selection of clinically relevant factors, logistic regression determined predictors of a severe outcome, which were incorporated into a risk model. RESULTS: 143 patients evaluated for button battery ingestion were analyzed. 24 (17%) had a severe outcome. The independent predictors of a severe outcome in multivariate analysis were location of battery in the esophagus on imaging (96%), battery size >/ = 2 cm (95%), and presence of any symptoms on presentation (96%), with P < 0.001 in all cases. Predicted probability of a severe outcome ranged from 88% when all three risk factors were observed, to 0.3% when none were present. CONCLUSION: We report the presentation, management, and complication profiles of a large cohort of BB ingestions treated at a single institution. A risk score to predict severe outcomes may be used by providers initially evaluating patients with button battery ingestion in order to allocate resources and expedite transfer to a center with pediatric endoscopic and surgical capabilities. LEVEL OF EVIDENCE: Level IV. TYPE OF STUDY: Clinical Research Paper.


Asunto(s)
Cuerpos Extraños , Niño , Humanos , Lactante , Adulto Joven , Adulto , Cuerpos Extraños/complicaciones , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/terapia , Esófago/diagnóstico por imagen , Esófago/cirugía , Endoscopía , Suministros de Energía Eléctrica , Factores de Riesgo , Ingestión de Alimentos
4.
J Pediatr Surg ; 58(7): 1359-1367, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35934523

RESUMEN

BACKGROUND: Indocyanine green (ICG) is commonly used to assess perfusion, but quality defining features are lacking. We sought to establish qualitative features of esophageal ICG perfusion assessments, and develop an esophageal anastomotic scorecard to risk-stratify anastomotic outcomes. METHODS: Single institution, retrospective analysis of children with an intraoperative ICG perfusion assessment of an esophageal anastomosis. Qualitative perfusion features were defined and a perfusion score developed. Associations between perfusion and clinical features with poor anastomotic outcomes (PAO, leak or refractory stricture) were evaluated with logistic and time-to-event analyses. Combining significant features, we developed and tested an esophageal anastomotic scorecard to stratify PAO risk. RESULTS: From 2019 to 2021, 53 children (median age 7.4 months) underwent 55 esophageal anastomoses. Median (IQR) follow-up was 14 (10-19.9) months; mean (SD) perfusion score was 13.2 (3.4). Fifteen (27.3%) anastomoses experienced a PAO and had significantly lower mean perfusion scores (11.3 (3.3) vs 14.0 (3.2), p = 0.007). Unique ICG perfusion features, severe tension, and primary or rescue traction-induced esophageal lengthening [Foker] procedures were significantly associated with PAO on both logistic and Cox regression. The scorecard (range 0-7) included any Foker (+2), severe tension (+1), no arborization on either segment (+1), suture line hypoperfusion >twice expected width (+2), and segmental or global areas of hypoperfusion (+1). A scorecard cut-off >3 yielded a sensitivity of 73% and specificity of 93% (AUC 0.878 [95%CI 0.777 to 0.978]) in identifying a PAO. CONCLUSIONS: A scoring system comprised of qualitative ICG perfusion features, tissue quality, and anastomotic tension can help risk-stratify esophageal anastomotic outcomes accurately. LEVELS OF EVIDENCE: Diagnostic - II.


Asunto(s)
Fuga Anastomótica , Verde de Indocianina , Humanos , Niño , Lactante , Angiografía con Fluoresceína/métodos , Fuga Anastomótica/diagnóstico , Fuga Anastomótica/etiología , Estudios Retrospectivos , Anastomosis Quirúrgica/métodos
5.
Dis Esophagus ; 36(3)2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36065605

RESUMEN

Children with esophageal atresia (EA) may require enteral tube feedings in infancy and a subset experience ongoing feeding difficulties and enteral tube dependence. Predictors of enteral tube dependence have never been systematically explored in this population. We hypothesized that enteral tube dependence is multifactorial in nature, with likely important contributions from anastomotic stricture. Cross-sectional clinical, feeding, and endoscopic data were extracted from a prospectively collected database of endoscopies performed in EA patients between August 2019 and August 2021 at an international referral center for EA management. Clinical factors known or hypothesized to contribute to esophageal dysphagia, oropharyngeal dysphagia, or other difficulties in meeting caloric needs were incorporated into regression models for statistical analysis. Significant predictors of enteral tube dependence were statistically identified. Three-hundred thirty children with EA were eligible for analysis. Ninety-seven were dependent on enteral tube feeds. Younger age, lower weight Z scores, long gap atresia, neurodevelopmental risk factor(s), significant cardiac disease, vocal fold movement impairment, and smaller esophageal anastomotic diameter were significantly associated with enteral tube dependence in univariate analyses; only weight Z scores, vocal fold movement impairment, and anastomotic diameter retained significance in a multivariable logistic regression model. In the current study, anastomotic stricture is the only potentially modifiable significant predictor of enteral tube dependence that is identified.


Asunto(s)
Trastornos de Deglución , Atresia Esofágica , Estenosis Esofágica , Humanos , Niño , Atresia Esofágica/cirugía , Constricción Patológica , Estudios Transversales , Nutrición Enteral , Intubación Gastrointestinal , Estudios Retrospectivos , Estenosis Esofágica/complicaciones , Resultado del Tratamiento
6.
Laryngoscope ; 132(4): 889-894, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34432299

RESUMEN

OBJECTIVES/HYPOTHESIS: The recurrent laryngeal nerve (RLN) is at risk during pediatric cervical, thoracic, and cardiac surgery. We aim to determine the feasibility and effectiveness of RLN monitoring techniques in all pediatric patients. STUDY DESIGN: Retrospective case series. METHODS: Retrospective review of patients/procedures with RLN(s) at risk and RLN monitoring at Boston Children's Hospital July 2019-October 2020. PRIMARY OUTCOMES: pre/postoperative vocal fold mobility by awake flexible fiberoptic laryngoscopy (FFL). RESULTS: One hundred one patients (median [interquartile range, IQR] age 14.6 months [4.6-49.7 months], weight 10 kg [5.2-16.2 kg]) underwent 122 procedures with RLN(s) at risk. RLN monitoring attempted 111 cases, successful 96 (84%). Surgical indications: esophageal atresia/tracheoesophageal fistula, and tracheobronchomalacia. Sixty-two (56%) procedures in reoperative field. Median follow-up 112 days (IQR 41-230). Pre/postoperative FFL performed 84 procedures (69%), 19 new postoperative RLN injuries (16%), median age 12 months, reoperative fields 11 (18%). Prass probes: 34 cases (28 successful, 82%), 6 injuries (18%), age 12.2 (5.8-23.6) months. Dragonfly electrodes: 45 cases (37 successful, 82%), 8 injuries (18%), age 7.5 (3.8-19) months. Nerve integrity monitoring (NIM) integrated electrode endotracheal tube: 33 cases (33 successful, 100%), 5 injuries (15%), age 90 (58.8-136.7) months. Automatic periodic stimulation (APS): 16 cases, 13 successful (81%), four injuries (25%), age 7.2 (5.3-20.6) months. NIM RLN monitoring is significantly more successful than Prass, Dragonfly (95%CI -0.3 to 0.02, P = .02; and 95%CI 0.05-0.31, P = .008). Rates of injury are not different between types of RLN monitoring (P = .94), with APS use (P = .47), or with monitoring success (95%CI -0.36 to 0.09, P = .28). CONCLUSIONS: RLN monitoring is feasible in pediatric patients of all ages. Although NIM type RLN monitoring success is superior, all forms offer similar rates of nerve protection. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:889-894, 2022.


Asunto(s)
Odonata , Nervio Laríngeo Recurrente , Animales , Niño , Electromiografía/métodos , Humanos , Monitoreo Intraoperatorio/métodos , Nervio Laríngeo Recurrente/cirugía , Estudios Retrospectivos , Tiroidectomía/métodos
7.
Pediatr Radiol ; 52(3): 468-476, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34845501

RESUMEN

BACKGROUND: Radiographic assessment of esophageal growth in long-gap esophageal atresia while on traction and associated traction-related complications have not been described. OBJECTIVE: To demonstrate how chest radiography can estimate esophageal position while on traction and to evaluate radiography's utility in diagnosing certain traction system complications. MATERIALS AND METHODS: In this retrospective evaluation of portable chest radiographs obtained in infants with long-gap esophageal atresia who underwent the Foker process between 2014 and 2020, we assessed distances between the opposing trailing clips (esophageal gap) and the leading and trailing clips for each esophageal segment on serial radiographs. Growth during traction was estimated using longitudinal random-effects regression analysis to account for multiple chest radiograph measurements from the same child. RESULTS: Forty-three infants (25 male) had a median esophageal gap of 4.5 cm. Median traction time was 14 days. Median daily radiographic esophageal growth rate for both segments was 2.2 mm and median cumulative growth was 23.6 mm. Traction-related complications occurred in 13 (30%) children with median time of 8 days from traction initiation. Daily change >12% in leading-to trailing clip distance demonstrated 86% sensitivity and 92% specificity for indicating traction-related complications (area under the curve [AUC] 0.853). Cumulative change >30% in leading- to trailing-clip distance during traction was 85% sensitive and 85% specific for indicating traction complications (AUC 0.874). CONCLUSION: Portable chest radiograph measurements can serve as a quantitative surrogate for esophageal segment position in long-gap esophageal atresia. An increase of >12% between two sequential chest radiographs or >30% increase over the traction period in leading- to trailing-clip distance is highly associated with traction system complications.


Asunto(s)
Atresia Esofágica , Anastomosis Quirúrgica , Niño , Atresia Esofágica/diagnóstico por imagen , Humanos , Lactante , Masculino , Estudios Retrospectivos , Tracción
8.
J Pediatr ; 241: 77-82.e1, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34687688

RESUMEN

OBJECTIVES: To describe growth and feeding outcomes in patients with type C esophageal atresia who underwent early primary repair and to identify predictors for poor growth. STUDY DESIGN: This single-center, retrospective, cohort study included all patients with type C esophageal atresia who underwent early primary repair from 2013 to 2019. Weight-for-age z score (WAZ) was calculated at birth, and every 6 months until 3 years postoperatively. Longitudinal median regression was used to evaluate WAZ over time. A multivariable logistic regression model explored predictors of growth outcomes. RESULTS: Of 46 infants who met the inclusion criteria, 72% were term. The median age at repair was 1.5 days of life (IQR, 1-2 days of life) and the hospital length of stay was 20 days (IQR-14, 30 days). Two patients had esophageal leak (4.3%). The median WAZ at birth was below average (-0.72; IQR, -1.37 to -0.40), but improved to reach average by 3 years (-0.025; IQR, -0.85 to 0.97, P < .001). At discharge, 72% of patients were receiving full oral nutrition, which improved to 95% by 3 years. The only independent predictor of poor growth at 1 year (WAZ < -1 [33%]) was WAZ at discharge (P = .02). CONCLUSIONS: Infants with esophageal atresia who undergo early primary repair are capable of achieving standard growth curves by 3 years of age. However, poor discharge WAZ score was predictive of poor WAZ score at 1 year. Efforts to identify at-risk patients and institute targeted inpatient and outpatient nutrition interventions are needed to improve their growth trajectory.


Asunto(s)
Desarrollo Infantil , Atresia Esofágica/cirugía , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estado Nutricional , Estudios Retrospectivos
9.
J Pediatr Surg ; 57(7): 1321-1330, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34509283

RESUMEN

BACKGROUND: Anti-reflux procedures (ARP) in esophageal atresia (EA) patients can be challenging and prone to failure. These challenges become more evident with increasing complexity of EA. We sought to determine predictors of ARP failure in complex EA patients. METHODS: Single-institution retrospective review of complex EA patients (e.g. long-gap EA, esophageal strictures, hiatal hernia, and reoperative ARP) who underwent an ARP from 2002 to 2019. ARP failure was defined as hiatal hernia recurrence, wrap migration/loosening, or need for reoperation. Predictors of failure were evaluated using univariate and multivariable time-to-event analysis. RESULTS: 121 patients underwent 140 ARP at a median age of 13.5 months (IQR 7, 26.5). Nissen fundoplication (89%) was the most common ARP. Mesh (bovine pericardium) reinforcement was used in 41% of the patients. Median follow-up was 3.2 years (IQR 0.9, 5.8); 44 instances of ARP failure occurred (31%), though only 20 (14%) required reoperation. Median time to failure was 8.7 months (IQR 3.2, 25). Though fewer mesh-reinforced ARP failed (21% with vs 39% without, p = 0.02), on multivariable analysis only partial fundoplication (aHR 2.22 [95% CI 1.01-4.78]) and minimally invasive repair (aHR 2.57 [95% CI 1.12-6.01]) were significant predictors of ARP failure. CONCLUSION: In our practice of complex EA patients, where ARP fail in nearly one third of cases, a Nissen fundoplication performed via laparotomy provided the lowest risk of ARP failure.


Asunto(s)
Atresia Esofágica , Reflujo Gastroesofágico , Hernia Hiatal , Laparoscopía , Animales , Bovinos , Atresia Esofágica/cirugía , Fundoplicación/métodos , Reflujo Gastroesofágico/etiología , Reflujo Gastroesofágico/cirugía , Hernia Hiatal/cirugía , Humanos , Laparoscopía/métodos , Recurrencia , Estudios Retrospectivos , Resultado del Tratamiento
11.
J Am Coll Surg ; 232(5): 690-698, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33556502

RESUMEN

BACKGROUND: A recurrent tracheo-esophageal fistula can complicate esophageal atresia and tracheo-esophageal fistula (TEF) repair in children. Therapeutic approaches and the rate of recurrence vary widely. Most reports are limited by small cohorts and short-term follow-up, and rates of re-recurrence are substantial, making it difficult to select the treatment of choice. We aimed to review our experience with the treatment of recurrent TEF using posterior tracheopexy, focusing on operative risks and long-term outcomes. STUDY DESIGN: We conducted a retrospective review of patients with esophageal atresia TEF with recurrent TEF treated at 2 institutions from 2011 to 2020. We approach recurrent TEFs surgically. Once the TEF is divided and repaired, the membranous trachea is sutured to the anterior longitudinal ligament of the spine (posterior tracheopexy) and the esophagus is rotated into the right chest (rotational esophagoplasty), separating the suture lines widely. To detect re-recurrence, patients undergo endoscopic surveillance during follow-up. RESULTS: Sixty-two patients with a recurrent TEF were surgically treated (posterior tracheopexy/rotational esophagoplasty) at a median age of 14 months. All had significant respiratory symptoms. On referral, 24 had earlier failed endoscopic and/or surgical attempts at repair. Twenty-nine required a concomitant esophageal anastomotic stricturoplasty or stricture resection. Postoperative morbidity included 3 esophageal leaks, and 1 transient vocal cord dysfunction. We have identified no recurrences, with a median follow-up of 2.5 years, and all symptoms have resolved. CONCLUSIONS: The surgical treatment of recurrent TEFs that incorporates a posterior tracheopexy and rotational esophagoplasty is highly effective for preventing re-recurrence with low perioperative morbidity.


Asunto(s)
Fuga Anastomótica/epidemiología , Atresia Esofágica/cirugía , Prevención Secundaria/métodos , Toracotomía/métodos , Fístula Traqueoesofágica/cirugía , Disfunción de los Pliegues Vocales/epidemiología , Anastomosis Quirúrgica/efectos adversos , Fuga Anastomótica/diagnóstico , Fuga Anastomótica/etiología , Niño , Preescolar , Atresia Esofágica/diagnóstico , Esofagoscopía , Esófago/diagnóstico por imagen , Esófago/cirugía , Femenino , Estudios de Seguimiento , Humanos , Lactante , Laringoscopía , Masculino , Recurrencia , Estudios Retrospectivos , Técnicas de Sutura/efectos adversos , Toracotomía/efectos adversos , Tráquea/diagnóstico por imagen , Tráquea/cirugía , Fístula Traqueoesofágica/diagnóstico , Resultado del Tratamiento , Disfunción de los Pliegues Vocales/etiología
12.
Eur Heart J Case Rep ; 4(3): 1-6, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32617483

RESUMEN

BACKGROUND: Glycogen storage disease type IV (GSD IV; Andersen's disease) is a rare autosomal recessive disease caused by mutation in the GBE1 gene. Presentation of GSD IV varies on a continuum of severity and symptomatology ranging from neonatal death to mild adult-onset disease with variable involvement of hepatic, muscular, neurologic, dermatologic, and cardiac systems. Cardiomyopathy seen in GSD IV is also heterogeneous and its appearance on cardiac magnetic resonance imaging (CMR) is rarely described. CASE SUMMARY: A 29-year-old man without previous medical history was admitted to our facility multiple times over 2 years for focal sensorimotor deficits, gout arthropathy, chronic hyperlactataemia and hyperuricaemia, and severe decompensated non-ischaemic cardiomyopathy complicated by episodes of thromboembolic organ infarction. Echocardiography and CMR showed severe biventricular failure with the presence of intraventricular thrombi with increased right ventricular trabeculation and absent late gadolinium enhancement. He underwent muscle biopsy which showed prominent glycogen in skeletal muscle followed by genetic testing showing a single heterozygous splicing mutation c.993-1G>T found at the junction of intron 7 and exon 8 of the GBE1 gene which had not previously been reported and was predicted to be pathologic. He was referred to a tertiary care centre with glycogen storage disease specialists but expired prior to establishing care at that facility. DISCUSSION: Discovery of GSD IV in our patient was unexpected due to a highly variant clinical presentation. Our case stresses the clinical heterogeneity of GSD IV and the importance of genetic sequencing studies in the evaluation of potential glycogen storage disease.

14.
Can J Cardiol ; 33(4): 555.e9-555.e11, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28159375

RESUMEN

A dual left anterior descending (LAD) artery is an infrequent anomaly of the coronary circulation with rare variations that may cause symptoms. We report a 60-year-old man who underwent multiple percutaneous cardiac catheterizations with stent placements and presented with recurrent angina pectoris. Coronary computed tomographic angiography demonstrated a dual LAD with the long and short LADs originating from the right coronary artery and the left main coronary artery, respectively.


Asunto(s)
Cateterismo Cardíaco/métodos , Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Anomalías de los Vasos Coronarios/diagnóstico , Vasos Coronarios/diagnóstico por imagen , Imagenología Tridimensional , Circulación Coronaria , Vasos Coronarios/fisiopatología , Diagnóstico Diferencial , Electrocardiografía , Humanos , Masculino , Persona de Mediana Edad
15.
Biomaterials ; 35(34): 9311-21, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25145852

RESUMEN

Current attempts at tissue regeneration utilizing synthetic and decellularized biologic-based materials have typically been met in part by innate immune responses in the form of a robust inflammatory reaction at the site of implantation or grafting. This can ultimately lead to tissue fibrosis with direct negative impact on tissue growth, development, and function. In order to temper the innate inflammatory response, anti-inflammatory signals were incorporated through display on self-assembling peptide nanofibers to promote tissue healing and subsequent graft compliance throughout the regenerative process. Utilizing an established urinary bladder augmentation model, the highly pro-inflammatory biologic scaffold (decellularized small intestinal submucosa) was treated with anti-inflammatory peptide amphiphiles (AIF-PAs) or control peptide amphiphiles and used for augmentation. Significant regenerative advantages of the AIF-PAs were observed including potent angiogenic responses, limited tissue collagen accumulation, and the modulation of macrophage and neutrophil responses in regenerated bladder tissue. Upon further characterization, a reduction in the levels of M2 macrophages was observed, but not in M1 macrophages in control groups, while treatment groups exhibited decreased levels of M1 macrophages and stabilized levels of M2 macrophages. Pro-inflammatory cytokine production was decreased while anti-inflammatory cytokines were up-regulated in treatment groups. This resulted in far fewer incidences of tissue granuloma and bladder stone formation. Finally, functional urinary bladder testing revealed greater bladder compliance and similar capacities in groups treated with AIF-PAs. Data demonstrate that AIF-PAs can alleviate galvanic innate immune responses and provide a highly conducive regenerative milieu that may be applicable in a variety of clinical settings.


Asunto(s)
Antiinflamatorios/farmacología , Nanofibras/química , Regeneración/efectos de los fármacos , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/fisiología , Animales , Femenino , Inmunidad Innata/efectos de los fármacos , Mucosa Intestinal , Intestino Delgado , Macrófagos/citología , Macrófagos/efectos de los fármacos , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Ratas , Ratas Desnudas , Andamios del Tejido/química
17.
J Biomed Mater Res A ; 100(3): 561-70, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22162300

RESUMEN

The ultimate success of in vivo organ formation utilizing ex vivo expanded "starter" tissues relies heavily upon the level of vascularization provided by either endogenous or artificial induction of angiogenic or vasculogenic events. To facilitate proangiogenic outcomes and promote tissue growth, an elastomeric scaffold previously shown to be instrumental in the urinary bladder regenerative process was modified to release proangiogenic growth factors. Carboxylic acid groups on poly(1,8-octanediol-co-citrate) films (POCfs) were modified with heparan sulfate creating a heparan binding POCf (HBPOCf). Release of proangiogenic growth factors vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF2), and insulin-like growth factor 1 (IGF-1) from HBPOCfs demonstrated an approximate threefold increase over controls during a 30-day time course in vitro. Atomic force microscopy demonstrated significant topological differences between films. Subcutaneous implantation of POCf alone, HBPOCf, POCf-VEGF, and HBPOCf-VEGF within the dorsa of nude rats yielded increased vascular growth in HBPOCf-VEGF constructs. Vessel quantification studies revealed that POCfs alone contained 41.1 ± 4.1 vessels/mm², while HBPOCf, POCf-VEGF, and HBPOCF-VEGF contained 41.7 ± 2.6, 76.3 ± 9.4, and 167.72 ± 15.3 vessels/mm², respectively. Presence of increased vessel growth was demonstrated by CD31 and vWF immunostaining in HBPOCf-VEGF implanted areas. Data demonstrate that elastomeric POCfs can be chemically modified and possess the ability to promote angiogenesis in vivo.


Asunto(s)
Citratos/química , Citratos/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Péptidos y Proteínas de Señalización Intercelular/farmacología , Neovascularización Fisiológica/efectos de los fármacos , Polímeros/química , Polímeros/metabolismo , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Elasticidad , Femenino , Heparitina Sulfato/metabolismo , Implantes Experimentales , Péptidos y Proteínas de Señalización Intercelular/química , Ensayo de Materiales , Microscopía de Fuerza Atómica , Ratas , Ratas Desnudas , Regeneración/efectos de los fármacos , Resistencia a la Tracción , Andamios del Tejido/química
18.
Stem Cells ; 29(2): 241-50, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21732482

RESUMEN

Animal models that have been used to examine the regenerative capacity of cell-seeded scaffolds in a urinary bladder augmentation model have ultimately translated poorly in the clinical setting. This may be due to a number of factors including cell types used for regeneration and anatomical/physiological differences between lower primate species and their human counterparts. We postulated that mesenchymal stem cells (MSCs) could provide a cell source for partial bladder regeneration in a newly described nonhuman primate bladder (baboon) augmentation model. Cell-sorted CD105(+) /CD73(+) /CD34(-) /CD45(-) baboon MSCs transduced with green fluorescent protein (GFP) were seeded onto small intestinal submucosa (SIS) scaffolds. Baboons underwent an approximate 40%-50% cystectomy followed by augmentation cystoplasty with the aforementioned scaffolds or controls and finally enveloped with omentum. Bladders from sham, unseeded SIS, and MSC/SIS scaffolds were subjected to trichrome, H&E, and immunofluorescent staining 10 weeks postaugmentation. Immunofluorescence staining for muscle markers combined with an anti-GFP antibody revealed that >90% of the cells were GFP(+) /muscle marker(+) and >70% were GFP(+) /Ki-67(+) demonstrating grafted cells were present and actively proliferating within the grafted region. Trichrome staining of MSC/SIS-augmented bladders exhibited typical bladder architecture and quantitative morphometry analyses revealed an approximate 32% and 52% muscle to collagen ratio in unseeded versus seeded animals, respectively. H&E staining revealed a lack of infiltration of inflammatory cells in grafted animals and in corresponding kidneys and ureters. Simple cystometry indicated recovery between 28% and 40% of native bladder capacity. Data demonstrate MSC/SIS composites support regeneration of bladder tissue and validate this new bladder augmentation model.


Asunto(s)
Células de la Médula Ósea/metabolismo , Células Madre Mesenquimatosas/metabolismo , Epiplón/fisiología , Regeneración/fisiología , Andamios del Tejido , Vejiga Urinaria/fisiología , Animales , Cistectomía , Matriz Extracelular/fisiología , Técnica del Anticuerpo Fluorescente , Proteínas Fluorescentes Verdes/genética , Mucosa Intestinal , Papio , Ingeniería de Tejidos , Vejiga Urinaria/cirugía
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