EP613 - Exploring Post-operative Days Alive and at Home in Chronic Kidney Disease Patients Undergoing Surgery for Complicated Diverticulitis

Purpose/Background: Current literature supports the use of primary anastomosis with proximal diverting ileostomy (PAPD) over Hartmann’s Procedure (HP) for the treatment of adults with complicated diverticulitis. Benefits include decreased morbidity/mortality, improved ostomy free survival, and overall increase in quality of life. No studies to date have demonstrated whether these benefits extend to patients with renal disease, a population markedly more susceptible to ileostomy related complications due to electrolyte derangements and fluid imbalance. Here, we aim to evaluate post-operative outcomes of older adults with renal disease undergoing PAPD or HP for diverticulitis using 6-month post-operative Days Alive and at Home (DAAH6Mo), an emerging patient-centered outcome metric.

Methods/Interventions: A retrospective cohort study was performed of community dwelling Medicare beneficiaries (65+ years old) with moderate to severe chronic kidney disease (CKD) as defined by ICD-10 diagnosis codes who required HP or PAPD for complicated diverticulitis. Data were extracted from a 20% random Medicare sample (July 2017-June 2019). 6-month mortality and intensive care unit (ICU) admission were extracted for the cohort. The DAAH6Mo outcome was calculated by subtracting total inpatient days, rehabilitation days, emergency department days, and mortality days from 180, beginning from the day of admission. HP and PAPD recipients were matched 1:6 by propensity score and generalized estimating equations were used to estimate DAAH6Mo for each group.

Results/Outcomes: 196 older adults with moderate to severe renal disease who underwent surgery for complicated diverticulitis were identified. The cohort was predominately white (87.2%) and female (57.1%). There was a low overall incidence of Alzheimer’s Dementia (10.7%) and Medicare/Medicaid dual enrollment (10.7%) in the cohort. Most patients were treated with HP (85.7%). Amongst all participants, 38.8% required ICU admission post-operatively and 21.9% died within 6 months of admission. Mean hospital length of stay was 12.3 days.

After matching, 20 PAPD patients were compared with 86 matched HP controls. Covariate balance was achieved across demographic and clinical characteristics, with standardized mean differences < 0.1 for all weighted variables. In the generalized estimating equation (GEE) model evaluating DAAH6mo between matched pairs, PAPD was associated with a non-significant increase in DAAH6mo compared to HP. The exponentiated least-squares mean for PAPD was 135.6 days (95% CI 115.5–159.1) versus 125.4 days (95% CI 110.7–142.0) for HP (p=0.48).

Conclusion/Discussion: Older adults with moderate to severe chronic kidney disease undergoing HP or PAPD for complicated diverticulitis have overall higher post-operative morbidity and mortality than the general population. Despite this, DAAH6mo did not vary significantly by surgical approach in this cohort. This composite outcome accounting for post-operative readmission, mortality, and time spent in healthcare settings quantifies a useful understanding of the post-operative experience of this patient population. These data suggests that functional outcomes and 6-month healthcare utilization do not differ substantially between these groups, and therefore PAPD may be a safe alternative to HP in older adults with renal disease undergoing surgery for diverticulitis despite the inherent challenges in managing an ileostomy with renal disease.