Influence of graft ischemic time and geographic distance between donor and recipient on survival in children after lung transplantation

Recipient Age Impacts Long-Term Survival in Adult Subjects with Cystic Fibrosis after Lung Transplantation

Rationale: Lung transplant is an effective treatment option providing survival benefit in patients with cystic fibrosis (CF). Several studies have suggested survival benefit in adults compared with pediatric patients with CF undergoing lung transplant. However, it remains unclear whether this age-related disparity persists in adult subjects with CF.Objectives: We investigated the impact of age at transplant on post-transplant outcomes in adult patients with CF.Methods: The United Network of Organ Sharing Registry was queried for all adult patients with CF who underwent lung transplantation between 1992 and 2016. Pertinent baseline characteristics, demographics, clinical parameters, and outcomes were recorded. The patients were divided into two groups based on age at transplant (18-29 yr old and 30 yr or older). The primary endpoint was survival time. Assessment of post-transplant survival was performed using Kaplan-Meier tests and log-rank tests with multivariable Cox proportional hazards analysis to adjust for confounding variables.Results: A total of 3,881 patients with CF underwent lung transplantation between 1992 and 2016; mean age was 31.0 (± 9.3) years. The 18-29-year-old at transplant cohort consisted of 2,002 subjects and the 30 years or older cohort had 1,879 subjects. Survival analysis demonstrated significantly higher survival in subjects in the 30 years or older cohort (9.47 yr; 95% confidence interval [CI], 8.7-10.2) compared with the 18-29-year-old cohort (5.21 yr; 95% CI, 4.6-5.8). After adjusting for confounders, survival remained higher in recipients aged 30 years or older (hazard ratio, 0.44; 95% CI, 0.2-0.9). Mortality due to allograft failure was significantly lower in patients with CF aged 30 years or older (28% vs. 36.5%; odds ratio [OR], 0.7; 95% CI, 0.6-0.8), whereas the incidence of malignancy was higher in the 30 years or older cohort (8% vs. 2.9%; OR, 3.0; 95% CI, 1.9-4.6).Conclusions: Age at transplant influences lung transplant outcomes in recipients with CF. Subjects with CF aged 30 years or older at transplant have superior survival compared with adult subjects with CF transplanted between the ages 18 and 29 years.

Differences in Travel Time to Cancer Surgery for Colon versus Rectal Cancer in a Rural State: A New Method for Analyzing Time-to-Place Data Using Survival Analysis

PURPOSE

Rectal cancer is rarer than colon cancer and is a technically more difficult tumor for surgeons to remove, thus rectal cancer patients may travel longer for specialized treatment compared to colon cancer patients. The purpose of this study was to evaluate whether travel time for surgery was different for colon versus rectal cancer patients.

METHODS

A secondary data analysis of colorectal cancer (CRC) incidence data from the Iowa Cancer Registry data was conducted. Travel times along a street network from all residential ZIP Codes to all cancer surgery facilities were calculated using a geographic information system. A new method for analyzing "time-to-place" data using the same type of survival analysis method commonly used to analyze "time-to-event" data is introduced. Cox proportional hazard model was used to analyze travel time differences for colon versus rectal cancer patients.

RESULTS

A total of 5,844 CRC patients met inclusion criteria. Median travel time to the nearest surgical facility was 9 minutes, median travel time to the actual cancer surgery facilities was 22 minutes, and the median number of facilities bypassed was 3. Although travel times to the nearest surgery facilities were not significantly different for colon versus rectal cancer patients, rectal cancer patients on average traveled 15 minutes longer to their actual surgery facility and bypassed 2 more facilities to obtain surgery.

DISCUSSION

In general, the survival analysis method used to analyze the time-to-place data as described here could be applied to a wide variety of health services and used to compare travel patterns among different groups.

Impact of Cold Ischemia Time on Frequency of Airway Complications Among Lung Transplant Recipients

BACKGROUND

The cold ischemia time (CIT) is a period of time between harvesting an organ for transplant and its reperfusion just after implantation. CIT may have an impact on frequency of complications after lung transplant that can be treated by means of bronchoscopic intervention. The aim of the study was to investigate the correlation between CIT and frequency of bronchoscopic intervention.

METHODS

The retrospective study consists of 91 patients: 22 single lung recipients (24%) and 69 double lung recipients (76%) who underwent lung transplant from March 2012 to June 2019. All statistical analyses were performed in SPSS 25.0 and R 3.5.3. The P levels less than .05 were deemed statistically significant.

RESULTS

The average CIT in single lung transplant was 5.91 hours, and in double lung transplant it was 8.61 hours. For the 4- to 8-hour CIT the percentages were 80.95% for single lung recipients and 46.38% for double lung recipients. For CIT longer than 8 hours, the following percentages were observed: 9.53% in single lung transplant and 53.62% in double lung transplant. Each subsequent hour of CIT exponentially increases the risk of intervention 1505 times (50.05%).

CONCLUSIONS

Prolonged CIT seems to be a risk factor for airway complication, especially in the double lung recipient group.

Risk factors for infection after pediatric lung transplantation

Although infection is the leading cause of death in the first year following pediatric lung transplantation, there are limited data on risk factors for early infection. Sepsis remains under-recognized and under-reported in the early post-operative period for lung transplant recipients (LTR). We evaluated the incidence of infection and sepsis, and identified risk factors for infection in the early post-operative period in pediatric LTRs. A retrospective review of medical records of LTRs at a large quaternary-care hospital from January 2009 to March 2016 was conducted. Microbiology results on days 0-7 after transplant were obtained. Sepsis was defined using the 2005 International Pediatric Consensus Conferencecriteria. Risk factors included history of recipient and donor infection, history of multi-drug resistant (MDR) infection, nutritional status, and surgical times. Among the 98 LTRs, there were 22 (22%) with post-operative infection. Prolonged donor ischemic time ≥7 hours, cardiopulmonary bypass(CPB) time ≥340 minutes, history of MDR infection and diagnosis of cystic fibrosis were significantly associated with infection. With multivariable regression analysis, only prolonged donor ischemic time remained significant (OR 4.4, 95% CI: 1.34-14.48). Further research is needed to determine whether processes to reduce donor ischemic time could result in decreased post-transplant morbidity.

Immunosuppression Drug Therapy in Lung Transplantation for Cystic Fibrosis

Cystic fibrosis (CF) is a common indication for lung transplantation (LTx) in children and adults with severe and irreversible lung disease. In the setting of LTx in the CF population, immunosuppressive medications are used to prevent allograft rejection despite the majority of these patients being chronically infected with numerous, and often antibiotic-resistant, pathogens. There is limited evidence for the optimal post-LTx immunosuppression regimen in patients with CF, particularly in children. This article provides a review of immunosuppression regimens in the pediatric and adult CF post-LTx population, investigating drug dosing and monitoring, and medication combinations. Currently used immunosuppressive medications and related systemic adverse effects are reviewed. With limitations of data in the pediatric population, future research should address immunosuppression in these children to help guide pediatric drug management as a means to optimize clinical outcomes after LTx.