Publikationsdatenbank

Evalution of the possibility of the existence of low-grade positioning dependent iatrogenic nerve injuries in small animals on the feline model (2019)

Art

Hochschulschrift

Autor

Slunsky, Pavel (WE 20)

Quelle

Berlin, 2019 — 42 Seiten

Sprache

Englisch

Verweise

URL (Volltext): https://refubium.fu-berlin.de/handle/fub188/25337

Kontakt

Klein- und Heimtierklinik

Oertzenweg 19 b
14163 Berlin
+49 30 838 62422
kleintierklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Positioning dependent neurological injuries present a well-known aetiological factor in human medicine with serious negative consequences for the patient. In animals, iatrogenic nerve injuries caused by inappropriate perioperative positioning are well described in large animals, but evidence-based information about the existence of this issue in small companion animals is missing. This cumulative dissertation consists of a foundational and applied research part.

1) The goals of the foundational research part were: - Selection of the appropriate small animal model; - Standardisation of the positioning and fixation methodologies; - Evaluation and quantification of the anatomical changes of the spinal column during perioperative positioning in the animal model as a basis for the further clinical study; - Determination of the more physiological perioperative position from an anatomical point of view.

European Shorthair cats with feline lower urinary tract disease (FLUTD) undergoing perineal urethrostomy were selected as an animal model. The positioning and fixation methodologies were standardised. Twenty-one male feline cadavers were enrolled in the study. All feline cadavers were evaluated by CT. Examinations were performed with the cadaver in a neutral position and dorsal and ventral recumbency. Sagittal vertebral canal diameters (VCDs) were obtained by measuring the distance between the ventral and dorsal aspects of the vertebral canal in the middle of the intervertebral space. A comparison of the VCDs between L6 and L7, L7 and S1, S3 and Co1 and Co1 and Co2 in neutral position vs dorsal recumbency revealed a reduction of 0.27 mm (14.6%; P <0.001) between S3 and Co1 and 0.26 mm (18.1%; P <0.001) between Co1 and Co2. No differences were seen when comparing L6–L7 and L7–S1. The VCDs were decreased in all segments when comparing neutral with ventral recumbency. This study revealed a reduction of 0.13 mm between L6 and L7 (3.3%; P = 0.003), 0.14 mm between L7 and S1 (4.1%; P = 0.003), 0.61 mm between S3 and Co1 (32.5%; P <0.001) and 0.63 mm between Co1 and Co2 (44.1%; P <0.001). Comparison of the VCD between dorsal and ventral recumbency in L6–L7, L7–S1, S3–Co1 and Co1–Co2 revealed a decrease in the VCDs in ventral recumbency of 0.13 mm (3.3%; P <0.001), 0.12 mm (3.6%; P <0.001), 0.34 mm (21.0%; P <0.001) and 0.37 mm (31.7%; P <0.001), respectively. The results provide evidence that, from an anatomical point of view, perineal urethrostomy performed in dorsal recumbency is superior to ventral recumbency, but further clinical study to verify these findings was needed.

2) The goals of the applied research part were: - Evaluation and quantification of the postoperative neurological changes associated with the perioperative positioning in the animal model and the determination of the existence or non-existence of positioning dependent nerve injury; - Determination of the more physiological position from a clinical point of view.

Twenty male castrated cats with FLUTD presented for perineal urethrostomy were enrolled in this study. Surgery was performed either in dorsal (group A) or in ventral recumbency (group B). Motor response of the patellar tendon, gastrocnemius muscle, pelvic limb withdrawal and perineal reflex, as well as the presence of spinal pain in the lumbosacral region, motor function of the tail and faecal continence were examined prior to surgery, 24 hours and 14 days after surgery. The mean weight of animals was 5.07 ± 1.08 kg with a mean age of 6.12 ± 1.85 years. Weight and age were not significantly different between groups A and B (both P = 0.897). All tested parameters of the neurological examination performed prior to surgery were considered normal in both groups (P = 1). The comparison between neurological examinations (perineal reflex and spinal pain) before and 24 hours after surgery revealed a significantly decreased briskness of the perineal reflex and an increased occurrence of spinal pain 24 hours after surgery (P = 0.043 and P = 0.031, respectively). However, the changes of aforementioned parameters were statistically insignificant (P = 0.249, P = 0.141) between groups A and B. The other parameters (patellar tendon, pelvic limb withdrawal and gastrocnemius muscle reflexes; motor function of the tail and faecal continence) were statistically insignificant (P = 1) before surgery and 24 hours after surgery, as well as between groups A and B 24 hours after surgery. Results of all tested parameters were statistically insignificant (P = 1) before surgery and 14 days after surgery, as well as between groups A and B 14 days after surgery. The briskness of the perineal reflex was significantly decreased and the occurrence of spinal pain significantly increased 24 hours after surgery. A parallel with a low-grade positioning dependent nerve injury as described in human medicine may be drawn. However, no fixation method has been proven to be superior to the other.