Deepak Mehta

Mitigation of tracheobronchomalacia with 3D-printed personalized medical devices in pediatric patients

Patient-specific, image-based design coupled with 3D biomaterial printing produced personalized implants for treatment of collapsed airways in patients with tracheobronchomalacia. Printing in 4D: Personalized implants The 3D printing revolution is in full swing, with frequent reports of printed kidneys and jaws, dolls and cars, food, and body armor. The new challenge is to make 3D materials evolve in the fourth dimension: time. Such “4D” materials could change in response to temperature, light, or even stress, making them adaptable and enduring. In pediatric medicine, 4D implants become particularly relevant; as the patient grows, so, too, should the material. Morrison et al. used 3D printing technology with a safe, bioresorbable polymer blend to create splints for three pediatric patients with tracheobronchomalacia (TBM)—a condition of excessive collapse of the airways during normal breathing. Currently available fixed-size implants can migrate and require frequent resizing. Thus, the authors used imaging and computational models to design the splints for each TBM patient’s individual geometries, structuring the implants to accommodate airway growth and prevent external compression over a period of time, before being resorbed by the body. In all three patients (one with two airways splinted), the 4D devices were implanted without issue. All four implants were stable and functional after 1 month, and one implant has remained in place, keeping the airway open for over 3 years. This pilot trial demonstrates that the fourth dimension is a reality for 3D-printed materials, and with continued human studies, 4D biomaterials promise to change the way we envision the next generation of regenerative medicine. Three-dimensional (3D) printing offers the potential for rapid customization of medical devices. The advent of 3D-printable biomaterials has created the potential for device control in the fourth dimension: 3D-printed objects that exhibit a designed shape change under tissue growth and resorption conditions over time. Tracheobronchomalacia (TBM) is a condition of excessive collapse of the airways during respiration that can lead to life-threatening cardiopulmonary arrests. We demonstrate the successful application of 3D printing technology to produce a personalized medical device for treatment of TBM, designed to accommodate airway growth while preventing external compression over a predetermined time period before bioresorption. We implanted patient-specific 3D-printed external airway splints in three infants with severe TBM. At the time of publication, these infants no longer exhibited life-threatening airway disease and had demonstrated resolution of both pulmonary and extrapulmonary complications of their TBM. Long-term data show continued growth of the primary airways. This process has broad application for medical manufacturing of patient-specific 3D-printed devices that adjust to tissue growth through designed mechanical and degradation behaviors over time.

Injection Laryngoplasty for Type 1 Laryngeal Cleft in Children

Objective. To review the 2-year, single-institution experience with injection laryngoplasty for diagnosis and treatment of type 1 laryngeal clefts (LC-1). Study Design. Case series with chart review. Setting. Tertiary care academic children’s hospital. Subjects and Methods. Patients at our institution who underwent injection laryngoplasty for LC-1 from January 2008 to December 2009. Outcome measures included patient demographics, surgical and anesthetic technique, effect on swallowing, and complications. Preoperative and postoperative swallowing evaluations were compared, and quality and duration of effects were calculated. Results. Sixteen children, 9 male and 7 female, underwent injection laryngoplasty for LC-1. Mean gestational age was 36.4 weeks (SD, 4.0 weeks; range, 27-41 weeks). Six patients had a major congenital anomaly (37.5%). Mean age at injection was 11.8 months (SD, 8.9 months; range, 2.9-33.5 months). Nine patients (56%) demonstrated complete resolution of penetration and aspiration on postoperative modified barium swallow (MBS), 4 patients (25%) had some improvement, and 3 patients (19%) showed no change. There were no complications. Mean duration of symptom improvement was 3.3 months (SD, 3.0 months; range, 0-11 months). Five patients went on to have definitive surgical LC-1 repair. Conclusion. Injection laryngoplasty was found to have favorable results in this group of patients with LC-1. Most patients experienced complete resolution of aspiration on MBS, and no patients experienced complications. These findings support the further study of injection laryngoplasty for LC-1 as both a diagnostic and therapeutic technique. Longer follow-up intervals are necessary to elucidate the predictive value with regard to success of formal cleft repair.

Sialoendoscopy for the treatment of pediatric salivary gland disorders.

OBJECTIVE To show that sialoendoscopy is both a safe and effective alternative to traditional treatments for juvenile recurrent parotitis and sialolithiasis. DESIGN Retrospective medical chart review. SETTING Two major pediatric tertiary care centers. PATIENTS Eighteen pediatric patients. INTERVENTIONS A total of 33 sialendoscopic procedures on 27 glands. MAIN OUTCOME MEASURES Indications for surgery, age at onset of symptoms, age at procedure, sex, intraoperative findings, complications, recurrences, need for additional procedures, and follow-up interval. RESULTS Juvenile recurrent parotitis was the most common indication for sialendoscopy (12 of 18) followed by sialolithiasis (4 of 18). Ten of 12 patients with juvenile recurrent parotitis were asymptomatic after 1 or 2 sialendoscopies (8 patients and 2 patients, respectively). There were 6 minor complications. Three patients ultimately required gland excision for disease management. CONCLUSION Sialoendscopy is safe and effective as a treatment for pediatric salivary gland disorders.

Preoperative cytology with molecular analysis to help guide surgery for pediatric thyroid nodules.

OBJECTIVES To discuss the use of molecular mutation analysis in the surgical management of pediatric thyroid nodules. METHODS This study is a case series with retrospective chart review performed at a tertiary childrens hospital. Pediatric patients who presented to the Childrens Hospital of Pittsburgh of UPMC with a thyroid nodule and had subsequent fine needle aspiration with positive molecular mutation between November 2009 and February 2012 were identified and charts were reviewed. Patient demographics, presenting signs, lab results, pathologic findings, and surgical outcomes were collected. RESULTS 5 pediatric patients with positive molecular mutation studies on preoperative FNA were identified. FNA results were categorized as follows: suspicious for follicular neoplasm (n = 2), suspicious for malignant cells (n = 1), and positive for malignant cells (n = 2). The following molecular mutations were identified: BRAF (V600E) (n = 2), PAX8/PPARγ (n = 1), HRAS (n = 1), and RET/PTC (n = 1). A total thyroidectomy was performed on each patient. In all cases the final pathology was positive for malignancy (papillary thyroid carcinoma (PTC), n = 3; follicular variant of PTC, n = 2). Three of five patients had transient postsurgical hypocalcemia. There were no other postoperative complications. CONCLUSIONS This series provides evidence that preoperative FNA with reflex molecular testing in pediatric thyroid nodules can help guide surgical decision making, reduce the need for repeat surgeries, and diminish the risk of complications from a staged procedure.

Transoral Robotic-Assisted Lingual Tonsillectomy in the Pediatric Population

IMPORTANCE Since technologic advances allow the use of robotic assistance in various surgical interventions performed to treat pediatric otolaryngology patients, the feasibility and outcomes of potential procedures must be assessed. OBJECTIVE To assess the feasibility and outcomes of robotic-assisted lingual tonsillectomy in the pediatric population. DESIGN, SETTING, AND PARTICIPANTS Retrospective medical record review in a tertiary care childrens hospital of 16 pediatric patients who underwent robotic-assisted lingual tonsillectomy from March 1, 2011, through December 31, 2012. INTERVENTION All patients underwent robotic-assisted lingual tonsillectomy using the da Vinci Surgical System (Intuitive Surgical, Inc) at the Childrens Hospital of Pittsburgh of the University of Pittsburgh Medical Center. MAIN OUTCOMES AND MEASURES Demographic data, comorbidities, robot docking time, operative time, estimated blood loss, and postoperative course, including complications in the immediate and longer-term postoperative period, were collected and analyzed. RESULTS All patients successfully underwent lingual tonsillectomy using the da Vinci Surgical System. Endotracheal intubation was performed in all patients and did not interfere with visualization of the oropharynx. Optimal retraction allowed visualization of pertinent structures and maximized transoral access. A significant learning curve from the first 5 surgical cases to subsequent cases with respect to robot docking time was observed (9 vs 3 minutes, respectively; P < .05). Operative time, estimated blood loss, and postoperative complication profiles are within the expected and acceptable limitations for performing lingual tonsillectomy in the pediatric population. CONCLUSIONS AND RELEVANCE Technologic advances have allowed miniaturization of robotic instrumentation and have expanded the scope of surgical options for the pediatric airway. Robotic-assisted lingual tonsillectomy is well tolerated and can be performed in the pediatric population with excellent success. It should be considered a feasible option for implementation at an institution-based level.

Injection Medialization Laryngoplasty in Children

OBJECTIVE To review our experience with vocal fold injection medialization in children. DESIGN Retrospective case series. SETTING Tertiary care academic childrens hospital. PATIENTS All pediatric patients at our institution who underwent injection laryngoplasty for vocal fold medialization from 2003 to 2009. MAIN OUTCOME MEASURES Age, sex, indication for injection, injection material, surgical and anesthetic technique, outcomes including effect on voice and swallowing, and complications. RESULTS Thirteen patients underwent 27 injections. Mean patient age was 8.0 years (range, 1.3-18.0 years). The causes of glottic insufficiency included prolonged intubation (6 patients, 46%), patent ductus arteriosus ligation (2 patients, 15%), other cardiac surgery (2 patients, 15%), neck surgery or trauma (2 patients, 15%), and postviral status (1 patient, 8%). Eight patients had vocal fold paralysis or paresis; 3 had vocal fold atrophy; and 2 had vocal fold scarring. Indications for surgery included hoarseness (11 patients), aspiration (5 patients), and dysphagia without aspiration (1 patient). Materials injected included Gelfoam (n = 13), Radiesse Voice (n = 10), and Radiesse Voice Gel (n = 4). The average number of injections per patient was 2.1 (range, 1-9). Patients experienced improvement in symptoms (subjective or objective) after injection in 24 of 27 cases (89%); 15 of 16 injections in patients with hoarseness led to improvement (94%); and 11 of 13 injections in patients with dysphagia or aspiration led to improvement (85%). One patient experienced 2 days of inspiratory stridor postoperatively, which resolved spontaneously. There were no other complications. CONCLUSIONS This study supports injection laryngoplasty as a safe and effective intervention for children with glottic insufficiency. Further prospective studies are necessary to confirm these findings.

A Novel Murine Model for the Examination of Experimental Subglottic Stenosis

OBJECTIVE To develop a novel mouse model of acquired subglottic stenosis (SGS) using heterotopic transplanted laryngotracheal complexes (LTCs). DESIGN Pilot randomized controlled animal study. SUBJECTS Forty-eight C57BL/6 mice. INTERVENTIONS Twenty-four donor C57BL/6 mice underwent LTC harvesting. The LTCs were then implanted deep to a cutaneous dorsal flap in 24 allogenic recipients. Sixteen LTCs underwent direct subglottic injury before transplantation, while 8 control LTCs were transplanted without injury. Transplanted LTCs were harvested 1, 2, 3, and 4 weeks after surgery. Tissues were fixed and cut transversely in 6-microm sections from the larynx to the second tracheal ring. Movat pentachrome staining was performed for connective tissue and morphometric analysis. Digital images of the subglottis were captured at x 20 magnification. The thicknesses of the lamina propria and the epithelium were measured at 5 random and equally spaced locations within the subglottic lumen. Vascular endothelial growth factor 164 (VEGF 164) and transforming growth factor beta1 (TGF-beta1) immunohistochemistry was performed on representative sections. RESULTS Lamina propria thickness was significantly greater in transplanted LTCs 3 and 4 weeks after injury compared with controls (P = .03, P = .01, respectively). Combined results (groups harvested at 1-4 weeks) revealed a significant difference between all 8 control animals and all 16 experimental animals (P < .001). Epithelial thickness was also greater in the transplanted LTCs 2, 3, and 4 weeks after injury to the subglottis compared with controls (P = .04 for weeks 2 through 4). Movat pentachrome staining showed random distributions and high concentrations of connective tissue within the lamina propria of the subglottis. The VEGF 164 and TGF-beta1 staining patterns were consistent with previous in vivo models of SGS. CONCLUSION Heterotopic transplanted LTCs in mice can provide an inexpensive and flexible model for experimental investigation of acquired SGS.

Transoral robotic-assisted laryngeal cleft repair in the pediatric patient

To assess the feasibility of performing robotic‐assisted laryngeal cleft repair in the pediatric population.

Laryngomalacia and swallowing function in children.

1) To determine the prevalence of dysphagia in children with laryngomalacia, 2) To ascertain whether severity of laryngomalacia influences the presence of swallowing dysfunction, and 3) To examine whether patients with medical comorbidities and laryngomalacia have a higher prevalence of swallowing dysfunction.

Role of polysomnography in the development of an algorithm for planning tracheostomy decannulation.

Objective To examine the role of polysomnography (PSG) in helping determine readiness of tracheostomized patients for decannulation. Study Design Case series with chart review of pediatric patients who underwent PSG with tracheostomy tube in place with the goal of decannulation. Setting Tertiary care pediatric center. Subjects and Methods Twenty-eight tracheostomized patients who underwent PSG from January 2006 to March 2012 were included. Outcome measures were successful decannulation, PSG results, surgical procedures, and medical comorbidities. Results Of the 28 patients, 20 (71.4%) were decannulated and 8 (28.6%) were not. One (3.6%) patient failed long-term decannulation. The average apnea-hypopnea index (AHI) with a capped tracheostomy for those successfully decannulated was 2.75 (range, 0.6-7.6), while the AHI for those not decannulated was 15.99 (range, 3.2-62). Factors associated with success or failure to decannulate were assessed, and an algorithm was developed to plan for successful decannulation. Laryngotracheal reconstruction was a significant factor in those successfully decannulated. Those who were not decannulated had multiple medical comorbidities, multilevel airway obstruction, need for additional surgery, or chronic need for pulmonary toilet. Conclusions Polysomnography may be a useful adjunctive study in the process of determining a patient’s readiness for decannulation. Our current algorithm for decannulation includes upper airway endoscopy with identification of levels of obstruction, followed by surgical correction of those obstructions; capped PSG to determine patency of the airway and help assess lung function; and overnight intensive care unit admission for capping trial, with decannulation the following day if well tolerated.