Brief Report: Robo1 Regulates the Migration of Human Subventricular Zone Neural Progenitor Cells During Development.

Human neural progenitor cell (NPC) migration within the subventricular zone (SVZ) of the lateral ganglionic eminence is an active process throughout early brain development. The migration of human NPCs from the SVZ to the olfactory bulb during fetal stages resembles what occurs in adult rodents. As the human brain develops during infancy, this migratory stream is drastically reduced in cell number and becomes barely evident in adults. The mechanisms regulating human NPC migration are unknown. The Slit-Robo signaling pathway has been defined as a chemorepulsive cue involved in axon guidance and neuroblast migration in rodents. Slit and Robo proteins expressed in the rodent brain help guide neuroblast migration from the SVZ through the rostral migratory stream to the olfactory bulb. Here, we present the first study on the role that Slit and Robo proteins play in human-derived fetal neural progenitor cell migration (hfNPC). We describe that Robo1 and Robo2 isoforms are expressed in the human fetal SVZ. Furthermore, we demonstrate that Slit2 is able to induce a chemorepellent effect on the migration of hfNPCs derived from the human fetal SVZ. In addition, when Robo1 expression is inhibited, hfNPCs are unable to migrate to the olfactory bulb of mice when injected in the anterior SVZ. Our findings indicate that the migration of human NPCs from the SVZ is partially regulated by the Slit-Robo axis. This pathway could be regulated to direct the migration of NPCs in human endogenous neural cell therapy. Stem Cells 2017;35:1860-1865.

Pediatric Postoperative Outcomes for Severe and Very Severe Obstructive Sleep Apnea Syndrome.

OBJECTIVE: To determine if increasing obstructive sleep apnea syndrome (OSAS) severity, as determined by preoperative polysomnography data, is an independent risk for respiratory complications and level of follow-up care after adenotonsillectomy or tonsillectomy. METHODS: A retrospective analysis of patients ≤21 years of age with severe OSAS (obstructive apnea-hypopnea index [OAHI] >10) undergoing adenotonsillectomy or tonsillectomy. Patients were categorized based on preoperative polysomnography data (PSG). Outcome measures including respiratory complications were collected via chart review. Logistic regression was used in the analysis of all parameters, and Wilcoxon Rank Sum tests were used for analysis of both OAHI and oxygen saturation nadir as continuous variables. All surgeries were performed at Johns Hopkins Hospital, a tertiary care center. RESULTS: We identified 358 patients with severe OSAS who had adenotonsillectomy or tonsillectomy. OAHI >40 and oxygen saturation nadir <80% were significantly associated with postoperative respiratory complications. Increasing OAHI and O2 saturation <80% was each associated with unplanned continuous positive airway pressure (CPAP) initiations postoperatively. There was no association between hypercarbia and presence of any complications. CONCLUSION: Patients with very severe OSAS (preoperative OAHI ≥40) as determined by preoperative PSG may be at higher risk of developing respiratory complications postoperatively. However, there does not appear to be a linear association with increasing severity of OAHI on regression analysis. Further research is needed to understand factors associated with complications in severe and very severe OAHI. LEVEL OF EVIDENCE: 4 Laryngoscope, 2024.

The Effect of Language Barriers at Discharge on Pediatric Adenotonsillectomy Outcomes and Healthcare Contact.

OBJECTIVE: Effective delivery of discharge instructions and access to postoperative care play a critical role in outcomes after pediatric surgery. Previous studies in the pediatric emergency department suggest that caregivers with language barriers have less comprehension of discharge instructions despite use of interpretation services. However, the impact of language barriers during discharge on surgical outcomes in a pediatric surgical setting has not been studied. This study examined the effect of parental language during discharge on number and mode of healthcare contact following pediatric adenotonsillectomy. METHODS: A retrospective cohort study was conducted on children who underwent adenotonsillectomy at a tertiary care pediatric academic medical center from July 1, 2016 to June 1, 2018. Data were collected on consecutive patients with non-English-speaking caregivers and a systematic sampling of patients with English-speaking caregiver. Surgery-related complications and healthcare contacts within 90 days after discharge were collected. Two-tailed t tests, χ2 tests, and logistic regression were performed to assess the association between parental primary language and incidence of healthcare contact after surgery. RESULTS: A total of 136 patients were included: 85 English-speaking and 51 non-English-speaking. The groups were comparable in age, sex, and comorbidities. The non-English group had more patients with public insurance (86% vs. 56%; P < .001). Number of encounters and types of complications following discharge were similar, but the non-English group was more likely to utilize the emergency department compared to phone calls (OR, 9.3; 95% CI, 2.3-38.2), even after adjustment for insurance type (OR, 7.9; 95% CI, 1.6-39.4). CONCLUSION: Language barriers at discharge following pediatric otolaryngology surgery is associated with a meaningful difference in how patients utilized medical care. Interventions to improve comprehension and access may help reduce preventable emergency department visits and healthcare costs.

Outcomes of Adenotonsillectomy for Obstructive Sleep Apnea in Prader-Willi Syndrome: Systematic Review and Meta-analysis.

OBJECTIVES: Prader-Willi syndrome (PWS) increases the risk of obstructive sleep apnea (OSA) due to obesity, hypotonia, and abnormal ventilatory responses. We evaluated post-adenotonsillectomy complications, polysomnography changes, and quality of life in children with OSA and PWS. STUDY DESIGN: Systematic review and meta-analysis. METHODS: We conducted a systematic review and meta-analysis by searching PubMed, Embase, Cochrane, Web of Science, and Scopus. Two researchers independently reviewed studies about adenotonsillectomy for OSA in patients <21 years with PWS. We extracted study design, patient numbers, age, complications, polysomnography, and quality of life. We pooled postoperative changes in apnea hypopnea index (AHI) for meta-analysis. We applied Methodological Index for Nonrandomized Studies (MINORS) criteria to assess study quality. RESULTS: The initial search yielded 169 studies. We included 68 patients from eight studies with moderate to high risk of bias. Six studies reported on complications and 12 of 51 patients (24%) had at least one. Velopharyngeal insufficiency was the most commonly reported complication (7/51, 14%). We included seven studies in meta-analysis. Mean postoperative improvement in AHI was 7.7 (95% CI: 4.9-10.5). Postoperatively 20% (95% CI: 3%-43%) had resolution of OSA with AHI < 1.5 while 67% (95% CI: 50%-82%) had improvement from severe/moderate OSA to mild/resolved (AHI < 5). Two studies evaluated quality of life and demonstrated improvement. CONCLUSIONS: Children with PWS undergoing adenotonsillectomy for OSA have a substantial risk of postoperative complications that may require additional interventions, especially velopharyngeal insufficiency. Despite improvements in polysomnography and quality of life, many patients had residual OSA. This information can be used to counsel families when considering OSA treatment options. Laryngoscope, 131:898-906, 2021.

Cardiopulmonary Testing before Pediatric Adenotonsillectomy for Severe and Very Severe Obstructive Sleep Apnea Syndrome.

OBJECTIVES/HYPOTHESIS: Adenotonsillectomy is first-line treatment for pediatric obstructive sleep apnea syndrome (OSAS) when not otherwise contraindicated. There is concern severe OSAS increases risk of comorbid cardiopulmonary abnormalities, such as ventricular hypertrophy or pulmonary hypertension, which preoperative testing could detect. Our objective is to determine if there is a severity of pediatric OSAS where previously undetected cardiopulmonary comorbidities are likely. STUDY DESIGN: Retrospective chart review. METHODS: We performed a retrospective review of 358 patients ≤21 years with severe OSAS who underwent adenotonsillectomy at a tertiary hospital June 1, 2016 to June 1, 2018. We extracted demographics, comorbidities, polysomnography, and preoperative tests. Wilcoxon rank-sum and logistic regression estimated associations of OSAS severity (based on obstructive apnea-hypopnea index [OAHI], hypoxia, hypercarbia) with preoperative echocardiograms and chest X-rays (CXRs). RESULTS: Mean age was 5.9 (±3.6) years and 52% were male. Mean OAHI and oxygen saturation nadir were 30.3 (±23.8) and 80.7% (±9.2), respectively. OAHI ≥60 was associated with having a preoperative echocardiogram (OR, 3.8; 95% CI, 1.7-8.5) or CXR (OR, 3.0; 95% CI, 1.4-6.8) compared to OAHI 10-59. There were no significant associations between OSAS severity and test abnormalities. The presence of previously diagnosed cardiopulmonary comorbidities was associated with abnormalities on echocardiogram (OR, 36; 95% CI, 4.1-320.1) and CXR (OR, 4.1; 95% CI, 1.2-14.4). CONCLUSIONS: Although pediatric patients with very severe OSAS (OAHI ≥60) underwent more pre-adenotonsillectomy cardiopulmonary tests, OSAS severity did not predict abnormal findings. Known cardiopulmonary comorbidities may be a better indication for cardiopulmonary testing than polysomnographic parameters, which could streamline pre-adenotonsillectomy evaluation and reduce cost. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2361-2368, 2021.