Readmission After Ileostomy Creation: Retrospective Review of a Common and Significant Event.

OBJECTIVE: To evaluate causes and predictors of readmission after new ileostomy creation. BACKGROUND: New ileostomates have been reported to have higher readmission rates compared with other surgical patients, but data on predictors are limited. METHODS: A total of 1114 records at 2 associated hospitals were reviewed to identify adults undergoing their first ileostomy. Primary outcome was readmission within 60 days of surgery. Multiple logistic regression was used to identify independent predictors; area under the receiver-operator characteristic curves (AUC) were used to evaluate age-stratified models in secondary analysis. RESULTS: In all, 407 patients underwent new ileostomy; 58% had cancer, 31% IBD; 49% underwent LAR, 27% colectomy, and 14% proctocolectomy. Median length of stay was 8 days. Among the patients, 39% returned to hospital, and 28% were readmitted (n = 113) at a median of 12 days postdischarge. The most common causes of readmission were dehydration (42%), intraperitoneal infections (33%), and extraperitoneal infections (29%). Dehydration was associated with later, longer, and repeated readmission. Independent significant predictors of readmission were Clavien-Dindo complication grade 3 to 4 [odds ratio (OR) 6.7], Charlson comorbidity index (OR 1.4 per point), and loop stoma (OR 2.2); longer length of stay (OR 0.5) and age 65 years or older (OR 0.4) were protective. Cohort stratification above or below age 65 revealed that older patient readmissions were more predictable (AUC 0.84) with more preventable causes, whereas younger patient readmissions were difficult to predict or prevent (AUC 0.65). CONCLUSIONS: Readmissions are most commonly caused by dehydration, and are predicted by serious complications, comorbidity burden, loop stoma, shorter length of stay, and age. Readmissions in older patients are easier to predict, representing an important target for improvement.

Diversity of ganglion cells in the mouse retina: unsupervised morphological classification and its limits.

The dendritic structures of retinal ganglion cells in the mouse retina were visualized by particle-mediated transfer of DiI, microinjection of Lucifer yellow, or visualization of green fluorescent protein expressed in a transgenic strain. The cells were imaged in three dimensions and the morphologies of a series of 219 cells were analyzed quantitatively. A total of 26 parameters were studied and automated cluster analysis was carried out using the k-means methods. An effective clustering, judged by silhouette analysis, was achieved using three parameters: level of stratification, extent of the dendritic field, and density of branching. An 11-cluster solution is illustrated. The cells within each cluster are visibly similar along morphological dimensions other than those used statistically to form the clusters. They could often be matched to ganglion cell types defined by previous studies. For reasons that are discussed, however, this classification must remain provisional. Some steps toward more definitive methods of unsupervised classification are pointed out.