Long-term assessment of nephrosplenic space closure in horses

Long-term assessment of nephrosplenic space (NSS) closure and comparisons with ultrasonography and rectal palpation are lacking. The objective was to evaluate NSS closure in 12 research horses 5 y following laparoscopic ablation, using a novel adhesion scoring system, and to assess whether rectal examination and ultrasonographic findings could predict adhesion adequacy. The NSS was examined via rectal palpation and ultrasonography prior to surgery, and at 30 d and 5 y after surgery. Ultrasonographic measurements of the distances between the renal fascia and spleen were recorded. The NSS adhesions were scored laparoscopically at 5 y and compared with ultrasound and rectal findings. Logistic regression was used for statistical analysis (P < 0.05). Three of 11 horses had adhesions considered inadequate for preventing colon entrapment. The remaining horses had strong adhesions in greater than 50% of the NSS. Ultrasonographic measurements of the caudal NSS decreased significantly over time (P < 0.05) but these changes were not predictive of adhesion adequacy. Surgery time, number of suture bites, or bleeding did not predict an adequate adhesion. Overall, laparoscopic NSS closure resulted in adequate adhesions in 8 out of 11 horses, persisting for at least 5 y. Rectal palpation was a reliable method for assessing NSS closure, whereas ultrasonography showed limited utility due to bowel interference and lack of predictive value. These findings support the long-term effectiveness of NSS closure and may help increase client confidence and adherence to this preventative surgical intervention.