Oncological outcomes of planned and unplanned low Hartmann's procedure and restorative low anterior resection for rectal cancer: a population-based cross-sectional study

Abstract

BACKGROUND: In the Netherlands, approximately 15% of patients with rectal cancer undergo a low Hartmann's procedure (low-HP). This is often preoperatively planned to avoid poor functional outcome or complications, but might be unplanned as a result of intraoperative difficulties. Low-HPs seem to be associated with worse oncological outcomes. METHODS: All patients who underwent either restorative low anterior resection (rLAR), planned low-HP, or unplanned low-HP for primary rectal cancer in 2016 were included from a nationwide cohort. Main outcomes were 4-year local recurrence (LR) rate and disease-free survival (DFS). RESULTS: Of 2043 patients, 1704 underwent rLAR (83.4%), 253 planned low-HP (12.4%), and 86 unplanned low-HP (4.2%). Among intended rLAR patients (n = 1790), independent risk factors for unplanned low-HP were older age, higher body mass index (BMI), higher American Society of Anesthesiologists (ASA) score, and more distal tumor location. Oncological outcomes after low-HPs were worse than after rLARs (LR 13.7% vs 5.6%, DFS 54.7% vs 71.8%, both p < 0.001), but similar for unplanned and planned low-HP. In multivariable analysis, unplanned and planned low-HP were not associated with LR or DFS, but R1 resection was (HR 6.6 (4.1-10.6), HR 3.0 (2.2-4.0), respectively). In R1 resections, the distal margin was more often involved after low-HP (70.0% vs 28.6%, p = 0.013) compared to rLAR. CONCLUSION: Poor outcomes in univariable analysis after low-HP appear to be associated with more challenging procedures and increased risk of involved resection margin rather than the low-HP itself. In case of expected difficulties, an extralevator abdominoperineal excision or referral to an expert center might be an alternative to improve resection margins. TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT05539417, retrospectively registered on September 16, 2022.