Short- and Long-Term Outcomes in Horses Following Laparoscopic Nephrosplenic Space Ablation

Left dorsal displacement of the large colon (LDDLC) is a common cause of colic in horses and it is frequently associated with recurrent episodes, with significant implications for horse management, athletic performance, and owner satisfaction. Laparoscopic nephrosplenic space (NSS) ablation is a preventive surgical technique aimed at reducing recurrence in horses with a history of medically or surgically treated LDDLC. This retrospective study evaluated 48 horses that underwent laparoscopic NSS ablation in two Italian Veterinary Teaching Hospitals between 2016 and 2024. Short-term outcomes, including immediate postoperative complications and discharge status, were assessed. Long-term follow-up data were collected via owner questionnaires, focusing on survival, recurrence of colic, post-surgical complications, return to athletic or breeding activity, and owner satisfaction. Most horses were discharged without complications (91.7%), while postoperative colic occurred in 8.3%. Kaplan-Meier estimated one-year post-discharge survival was 83.3%, and 81.3% of horses were alive at last follow-up (range 0.7 months to 8.8 years). Post-discharge complications were reported in 31.2% of horses, most commonly recurrent LDDLC. Return to preoperative athletic or breeding activity was reported in 70.8% of cases, and owner satisfaction was high (83.3%). Time-to-event analysis indicated markedly reduced survival in horses requiring laparotomy during follow-up. Bayesian logistic models suggested lower mortality and fewer post-discharge complications in horses with prior colic surgery, whereas a history of recurrent colic and laparotomy during follow-up was associated with higher mortality and complications. These results indicate that laparoscopic NSS ablation is an effective and safe procedure for long-term management of horses at risk of LDDLC, allowing a high rate of survival, functional recovery, and owner satisfaction, despite the persistence of occasional colic episodes.