Endoscope-assisted three-wire technique for extensive nasal septum resection in horses.

OBJECTIVE: To describe a 3-wire method with endoscopic guidance for extensive nasal septum resection. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Thirteen horses with nasal septum diseases. METHODS: In anesthetized horses in left lateral recumbency, endoscopic guidance was used to place obstetrical wires for the ventral and caudal incisions in the nasal septum and a trephine opening was used to place the dorsal wire. The rostral aspect of the septum was incised with a scalpel, followed by incisions with the preplaced wires, and the nasal passages were packed with gauze. Horses were recovered with a temporary tracheotomy. RESULTS: Conversion to intraoral placement of wires was required in two horses, one to correct entangled wires and the other because hemorrhage obscured the endoscopic view. Exercise tolerance was improved postoperatively, abnormal respiratory noise was decreased or eliminated by surgery in all horses, and all owners were satisfied. One Thoroughbred racehorse performed with modest success. CONCLUSIONS: Modification of the 3-wire method was effective and safe for extensive nasal septum removal. Technical complications of the procedure include entangling of wires and intraoperative hemorrhage. CLINICAL SIGNIFICANCE: Endoscopic guidance can be used to place obstetrical wires for nasal septum resection in small horses and precludes use of a large tracheotomy for anesthetic delivery. Reasons for athletic failures were difficult to establish retrospectively, although assessment of postoperative noise at speed might be more relevant to recovery of athletic potential than assessment at slower gaits.

Three-dimensional models of the equine larynx can be used to perform traditional measures of arytenoid abduction and permit the positioning of modeled implants to demonstrate the anatomic feasibility of placing a rigid implant across the cricoarytenoid joint.

OBJECTIVE: To develop 3D models of larynges to compare arytenoid abduction measurements between specimens and models, and to investigate the anatomic feasibility of placing an implant across the cricoarytenoid joint (CAJ) with or without arthrotomy. SAMPLES: Cadaveric equine larynges (n = 9). PROCEDURES: Equine larynges underwent sequential CT scans in a neutral position and with 2 arytenoid treatments: bilateral arytenoid abduction (ABD) and bilateral arytenoid abduction after left cricoarytenoid joint arthrotomy (ARTH). Soft tissue, cartilage, and luminal volume 3-dimensional models were generated. Rima glottidis cross-sectional area (CSA) and left-to-right quotient (LRQ) angles were measured on laryngeal specimens and models. Arytenoid translation, articular contact area, and length of modeled implants placed across the CAJ were measured on models. Data were analyzed using paired t test or ANOVA and Tukey's post hoc test or non-parametric equivalents (P < .05). RESULTS: ARTH CSA was larger for laryngeal specimens than models (P = .0096). There was no difference in all other measures of CSA and LRQ angle between treatment groups or between specimens and models. There was no difference between ABD and ARTH groups for arytenoid cartilage translation, contact area, and implant length. The articular contact area was sufficient for modeled implant placement across the CAJ with a narrow range of implant lengths (17.59 mm to 23.87 mm) across larynges with or without arthrotomy. CLINICAL RELEVANCE: These results support further investigation of a CT-guided, minimally invasive surgical procedure. Future studies will evaluate the outcomes of the new procedure for technical precision, biomechanical stability, and post-operative success rates for horses with recurrent laryngeal neuropathy (RLN).

Three-dimensional printed surgical guides for keratoma removal in horses using computed tomography or magnetic resonance imaging-based segmentation.

OBJECTIVE: To report the technique, surgical approach, and postoperative features in horses treated via a 3-dimensional (3D) printed guide-assisted keratoma resection created using computed tomography (CT) or magnetic resonance imaging (MRI)-based segmentation. ANIMALS: Five client-owned horses. STUDY DESIGN: Short case series. METHODS: Horses were placed under general anesthesia for imaging (CT and MRI) and underwent a second anesthesia for surgery. Two horses had guides created from CT-based imaging, 3 horses had guides created from MRI. Various sized nonarbored hole saws were used to create accurate and precise portals for keratoma removal. Surgical sites were managed until keratinized granulation tissue had formed and the defect was sealed with an artificial hoof wall patch. RESULTS: All keratomas were successfully removed as a single piece either intact with the hoof wall or easily extracted after the hoof wall portal was created in a surgical time between 20 and 90 min. All CT created guides fitted without issue; MRI-created guides required minor adjustments with a rotary device for proper fit. All cases had minor debridement adjacent to P3 and circumferential lamellar tissue. All horses returned to previous level of performance 2 to 4 months postoperatively. CONCLUSION: Use of 3D printed guides led to accurate targeting of keratomas with small surgical portals and short surgical times. Due to challenges with MRI-based segmentation, CT is preferred.