Primary anastomosis with diverting loop ileostomy vs. Hartmann's procedure for acute diverticulitis: what happens after discharge? Results of a nationwide analysis.

BACKGROUND: Current guidelines recommend resection with primary anastomosis with diverting loop ileostomy over Hartmann's procedure if deemed safe for acute diverticulitis. The primary objective of the current study was to compare the utilization of these strategies and describe nationwide ostomy closure patterns and readmission outcomes within 1 year of discharge.

METHODS: This was a retrospective, population-based, cohort study of United States Hospitals reporting to the Nationwide Readmissions Database from January 2011 to December 2019. There were 35,774 patients identified undergoing non-elective primary anastomosis with diverting loop ileostomy or Hartmann's procedure for acute diverticulitis. Rates of ostomy closure, unplanned readmissions, and complications were compared. Cox proportional hazards and logistic regression models were used to control for patient and hospital-level confounders as well as severity of disease.

RESULTS: Of the 35,774 patients identified, 93.5% underwent Hartmann's procedure. Half (47.2%) were aged 46-65 years, 50.8% female, 41.2% publicly insured, and 91.7% underwent open surgery. Primary anastomosis was associated with higher rates of 1-year ostomy closure (83.6% vs. 53.4%, p < 0.001) and shorter time-to-closure [median 72 days (Interquartile range 49-103) vs. 115 (86-160); p < 0.001]. Primary anastomosis was associated with increased unplanned readmissions [Hazard Ratio = 2.83 (95% Confidence Interval 2.83-3.37); p < 0.001], but fewer complications upon stoma closure [Odds Ratio 0.51 (95% 0.42-0.63); p < 0.001]. There were no differences in complications between primary anastomosis and Hartmann's procedure during index admission [Odds Ratio = 1.13 (95% Confidence Interval 0.96-1.33); p = 0.137].

CONCLUSION: Patients who undergo primary anastomosis for acute diverticulitis are more likely to undergo ostomy reversal and experience fewer postoperative complications upon stoma reversal. These data support the current national guidelines that recommend primary anastomosis in appropriate cases of acute diverticulitis requiring operative treatment.