Cumulative summation analysis of learning curve for robotic-assisted hiatal hernia repairs.

BACKGROUND: Robotic-assisted laparoscopic surgery (RALS) is evolving as an important surgical approach in the field of general surgery. We aimed to evaluate the learning curve for RALS procedures involving repair of hiatal hernias. METHODS: A series of robotic-assisted hiatal hernia (HH) repairs were performed between 2013 and 2017 by a surgeon at a single institution. Data were entered into a retrospective database. Patient demographics and intraoperative parameters including console time (CT), surgery time (ST), and total operative time (OT) were examined and abstracted for learning curve analysis using the cumulative sum (CUSUM) method. Assessment of perioperative and post-operative outcomes were calculated using descriptive statistics. RESULTS: The average age of the patients was 57.4 years, average BMI was 29.9 kg/m2, median American Society of Anesthesiologists (ASA) classification was 2, and average Charlson Comorbidity Index (CCI) score was 2.8. The series had a mean CT of 132.6 min, mean ST of 145.1 min, and mean OT of 197.4 min. The CUSUM learning curve for CT was best approximated as a third-order polynomial consisting of three unique phases: the initial training phase (case 1-40), the improvement phase (case 41-85), and the mastery phase (case 86 onwards). There was no significant difference in perioperative complications between the phases. Short-term clinical outcomes were comparable with national standards and did not correlate significantly with operative experience. CONCLUSIONS: The three phases identified with CUSUM analysis represented characteristic stages of the learning curve for robotic hiatal hernia procedures. Our data suggest the training phase is achieved after 40 cases and a high level of mastery is achieved after approximately 85 cases. Thus, the CUSUM method serves as a useful tool for objectively evaluating practical skills for surgeons and can ultimately help establish milestones that assess surgical competency during robotic surgery training.

Relationship between degree of obstruction and airflow limitation in subglottic stenosis.

OBJECTIVES: Subglottic stenosis (SGS) is one of the most common airway disorders in pediatric patients. Currently, treatment decisions rely primarily on the Cotton-Myer scale, which classifies SGS severity based on percentage reduction in airspace cross-sectional area (CSA). However, the precise relationship between upper airway resistance and subglottic CSA is unknown. We hypothesize that airway resistance can be described by the Bernoulli Obstruction Theory, which predicts that airway resistance is inversely proportional to airspace CSA ( R∝A-1) in cases of severe constriction. METHODS: Computed tomography (CT) scans of six healthy subjects and five SGS patients were used to create three-dimensional models of the respiratory tract from nostrils to carina. Cylindrical segments of varying lengths and varying diameters were digitally inserted in the subglottis of the healthy subjects to create simulated SGS models. Computational fluid dynamics simulations were run, and airway resistance was computed in the simulated SGS models and actual SGS models. RESULTS: Constriction diameter had a greater impact in airway resistance than constriction length. In agreement with the Bernoulli Obstruction Theory, airway resistance in the simulated SGS models was well represented by the power law R=aAb, where a is a constant and the exponent b ranged from -0.85 to -1.07. The percentage reduction in airflow (QOBSTRUCTIONQHEALTHY) at a constant pressure drop was found to be directly proportional to the percentage reduction in CSA (AOBSTRUCTIONAHEALTHY) in the limit of severe constrictions, namely QOBSTRUCTIONQHEALTHY=kAOBSTRUCTIONAHEALTHY, where k=2.25 ± 0.15. Airway resistances in the simulated SGS models were similar to resistances in models based on CT scans of actual SGS patients, suggesting that our simulated SGS models were representative of airway resistance in actual SGS patients. CONCLUSION: Our computer simulations suggest that the degree of airflow limitation in SGS patients may be estimated based on anatomic measurements alone. Future studies are recommended to test these predictions in larger cohorts. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1551-1557, 2018.

Emergency Contraception Pill Awareness and Knowledge in Uninsured Adolescents: High Rates of Misconceptions Concerning Indications for Use, Side Effects, and Access.

STUDY OBJECTIVE: To determine the awareness of, access to, and knowledge of the proper use of emergency contraception pills (ECPs) among uninsured adolescents. DESIGN: Anonymous surveys were used to assess awareness of, knowledge of, and access to ECPs. SETTING: From 2010 to 2012 at mobile primary care clinic in the San Francisco Bay Area. PARTICIPANTS: Patients were uninsured adolescents aged 13 to 25; 40% of the participants were currently or had been homeless in the past year. Ethnicity was 50% Asian, 22% Hispanic, 17% Pacific Islanders, 5.5% white, and 5.5% other/mixed ethnicity. INTERVENTIONS: Post survey completion, patients received one-on-one 15-minute dedicated ECP education. MAIN OUTCOME MEASURES: Awareness of, knowledge of, and access to ECPs. RESULTS: Of the study population of 439, 30% of the participants were 13-16 years old and 70% were 17-25 years old (mean age 17.8 years); 66% were women. Young women (86%) reported higher rates of "hearing about emergency contraception" than did young men (70%) (P < .0001). Many incorrectly identified or were uncertain if ECPs were an abortion pill (40%) or could be used as regular birth control (40%) or to prevent sexually transmitted infections (19%). Only 40% of women and 43% of men aged 17 and older correctly answered that they could obtain EC over the counter; 72% did not know that males could receive EC for use by their partner; 12% incorrectly selected that infertility was a side effect; 44% were under the false impression that EC had to be taken within 1 day of unprotected sex. CONCLUSIONS: Uninsured adolescents have high rates of ECP awareness but low ECP knowledge. These adolescents need more ECP education to alleviate misconceptions and increase practical knowledge, specifically, education about male access, side effects, over-the-counter availability for young men and women, and the 120-hour window of use.