Preclinical assessment of resorbable silk splints for the treatment of pediatric tracheomalacia.

OBJECTIVE: Tracheomalacia is characterized by weakness of the tracheal wall resulting in dynamic airway collapse during respiration; severe cases often require surgical intervention. Off-label external splinting with degradable implants has been reported in humans; however, there remains a need to develop splints with tunable mechanical properties and degradation profiles for the pediatric population. The objective of this pilot study is to assess the safety and efficacy of silk fibroin-based splints in a clinically relevant preclinical model of tracheomalacia. METHODS: Silk splints were evaluated in a surgically induced model of severe tracheomalacia in N = 3 New Zealand white rabbits for 17, 24, and 31 days. An image-based assay was developed to quantify the dynamic change in airway area during spontaneous respiration, and histopathology was used to study the surrounding tissue response. RESULTS: The average change in area in the native trachea was 23% during spontaneous respiration; surgically induced tracheomalacia resulted in a significant increase to 86% (P < 0.001). The average change in airway area after splint placement was reduced at all terminal time points (17, 24, and 31 days postimplantation), indicating a clinical improvement, and was not statistically different than the native trachea. Histopathology showed a localized inflammatory reaction characterized by neutrophils, eosinophils, and mononuclear cells, with early signs suggestive of fibrosis at the splint and tissue interface. CONCLUSION: This pilot study indicates that silk fibroin splints are well tolerated and efficacious in a rabbit model of severe tracheomalacia, with marked reduction in airway collapse following implantation and good tolerability over the studied time course. LEVEL OF EVIDENCE: NA Laryngoscope, 129:2189-2194, 2019.

A standardised investigative strategy prior to revisional oesophageal surgery in children: High incidence of unexpected findings.

BACKGROUND/PURPOSE: Revisional oesophageal reconstructive surgery carries uncommon and unusual risks related to previous surgery. To provide maximum anatomical detail and facilitate successful outcome, we report a standardised pre-operative investigative strategy for all such patients. METHODS: Prospective 8-month cohort study following the introduction of this strategy. All patients underwent high resolution thoracic contrast CT scan and micro-laryngo-bronchoscopy by a paediatric ENT surgeon in addition to upper gastrointestinal contrast study, oesophagoscopy, and echocardiogram. RESULTS: Seven children (median age 5.6 months [range 2.2-60]) completed the pathway. Four were referred with recurrence of a previously divided tracheo-oesophageal fistula (3 congenital, 1 acquired) and 3 (all with oesophagostomy) for oesophageal replacement for congenital isolated oesophageal atresia (OA, n=1) and failed repair of OA with distal TOF with wide gap (n=2). Overall, unanticipated findings were demonstrated in 6/7 children and comprised severe tracheomalacia and right main bronchus stenosis requiring aortopexy (n=1), vocal cord palsy (n=2), extensive mediastinal rotation (n=1), proximal tracheal diverticulum (n=1), severe subglottic stenosis requiring airway reconstruction (n=1), proximal tracheal diverticulum (n=1), right sided aortic arch (n=1) and left sided aortic arch (previously reported to be right sided, n=1). CONCLUSIONS: This standardised approach for this complex group of patients reveals a high incidence of unexpected anatomical and functional anomalies with significant surgical and possible medico-legal implications. We recommend these investigations during the pre-operative work-up prior to all revisional oesophageal surgery.

The development of cardiac surgery in West Africa--the case of Ghana.

West Africa is one of the poorest regions of the world. The sixteen nations listed by the United Nations in this sub-region have some of the lowest gross domestic products in the world. Health care infrastructure is deficient in most of these countries. Cardiac surgery, with its heavy financial outlay is unavailable in many West African countries. These facts notwithstanding, some West African countries have a proud history of open heart surgery not very well known even in African health care circles. Many African health care givers are under the erroneous impression that the cardiovascular surgical landscape of West Africa is blank. However, documented reports of open-heart surgery in Ghana dates as far back as 1964 when surface cooling was used by Ghanaian surgeons to close atrial septal defects. Ghana's National Cardiothoracic Center is still very active and is accredited by the West African College of Surgeons for the training of cardiothoracic surgeons. Reports from Nigeria indicate open-heart surgery taking place from 1974. Cote D'Ivoire had reported on its first 300 open-heart cases by 1983. Senegal reported open-heart surgery from 1995 and still runs an active center. Cameroon started out in 2009 with work done by an Italian group that ultimately aims to train indigenous surgeons to run the program. This review traces the development and current state of cardiothoracic surgery in West Africa with Ghana's National Cardiothoracic Center as the reference. It aims to dispel the notion that there are no major active cardiothoracic centers in the West African sub-region.