Laser Vaporization of the Dorsal Turbinate as an Alternative Method of Accessing and Evaluating the Paranasal Sinuses

Objective: To report a technique for stoma creation into the conchofrontal sinus (CFS) through the dorsal turbinate and to evaluate stoma as a site for sinoscopy. Study Design: Prospective experimental study. Animals: Cadaveric equine heads (n=2) and normal adult horses (5). Methods: Technique feasibility was established on 2 cadaver heads. A diode laser fiber with a contact probe was passed into the nasal passage through a custom built, laser introducer rod (LIR). A videoendoscope was passed ventral to the LIR. A site on the caudal, medial aspect of the turbinate overlying the dorsal conchal sinus (DCS) was identified. A stoma to facilitate endoscope passage was created through the turbinate and sinoscopy performed to identify structures within the CFS and caudal maxillary sinus (CMS) and to evaluate the quality of the approach. The procedure was then performed in standing, sedated horses. Time required, laser energy used and complications were recorded. Endoscopy was performed ≥5 weeks postoperatively to assess stoma size and long‐term effects of the procedure. Results: A stoma was successfully created through the turbinate in both cadaveric skulls and in 4 horses; the stoma persisted for ≥5 weeks. The location of the stoma in 1 horse precluded sinoscopy. Conclusions: Laser vaporization of the dorsal turbinate through the nasal passage creates a stoma that lasts for at least 5 weeks providing a portal to the paranasal sinuses. Based on experience in 1 horse stoma location is critical to ensure adequate endoscope manipulation and sinoscopy. Clinical Relevance: Standing endoscopic sinusotomy within the nasal cavity through the DCS is an alternative to more invasive sinusotomy techniques with fewer potential complications and a cosmetic result.     

In Vitro Mechanical Comparison of 2.0 and 2.4 Limited‐Contact Dynamic Compression Plates and 2.0 Dynamic Compression Plates of Different Thicknesses

Objective: To compare the bending structural stiffness and bending strength of thick and thin 2.4 mm limited contact dynamic compression plates (2.4 LC‐DCP), 2.0 mm LC‐DCP (2.0 LC‐DCP), and 2.0 dynamic compression plates (2.0 DCP). Study Design: In vitro mechanical study. Methods: Two thicknesses of 2.4 LC‐DCP, 2.0 LC‐DCP, and 2.0 DCP stainless‐steel plates were tested in 4‐point bending. Data were collected during bending until implants plastically deformed. Bending structural stiffness and bending strength were determined from load displacement curves. Mechanical properties were compared between plates and the effects of plate type, size, and thickness on stiffness and strength were assessed using ANOVA. Results: The thick 2.4 LC‐DCP implant was the stiffest and strongest; the thin 2.0 DCP implant was most compliant and weakest. Larger sized plates, thicker plates, and limited contact design of plates enhanced stiffness and strength. For the plates studied, plate size had a larger effect than plate type or thickness on stiffness and strength. Conclusion: Increasing the size (width) and thickness of plates increases both the bending structural stiffness and strength. For the plates studied, LC‐DCP implants were stiffer and stronger than DCP implants. Clinical Relevance: Plate bending structural stiffness and strength can be most effectively enhanced by using a larger sized plate, but gains can also be achieved by using a thicker plate and/or an LC‐DCP instead of a DCP implant when possible.     

Pararectal Cystotomy for Urolith Removal in Nine Horses

Objective: To report outcome of horses after standing pararectal cystotomy for removal of uroliths. Study Design: Case series. Animals: Horses (n=9) with cystic calculi. Methods: Medical records (December 1998–May 2007) of horses with cystic calculi that had standing pararectal cystotomy were reviewed. Signalment; urolith number, size, and type; surgical technique; sedation and analgesia protocols; intra‐ and postoperative complications and outcome were analyzed. Results: Uroliths (mean diameter, 6.37 cm; median, 6 cm; range, 3–10 cm) were removed intact without need for fragmentation. Eight (89%) horses had no complications and 1 horse (11%) developed persistent drainage from the perineal incision and incisional healing was prolonged. The complications resolved after wound revision, and although cystoscopy showed absence of uroliths, the clinical signs associated with cystitis recurred. Conclusions: Cystic calculi can be removed safely in standing horses using a pararectal approach. The procedure was well tolerated and no serious complications were encountered. Clinical Relevance: Pararectal cystotomy allows removal of cystic calculi in standing sedated horses. The technique may offer an economic advantage over approaches that require general anesthesia.     

Risk Factors for Femoral Fracture after Canine Press‐Fit Cementless Total Hip Arthroplasty

Objective: To evaluate risk factors for femoral fracture after porous‐coated cementless total hip arthroplasty (THA). Study Design: Case series. Animals: Dogs (n=74) that had cementless THA (n=84). Methods: Medical records of dogs from 2 referral hospitals were reviewed for occurrence of postoperative femoral fracture. Patient and operative (age, breed, sex, weight, and canal flare index [CFI], indication for arthroplasty, intraoperative fissure, cerclage usage, and implant sizes) factors were analyzed. Assessment of implant positioning and canal fill was performed on immediate postoperative radiographs. Femoral fractures (n=11) were evaluated and compared with 73 cases without fracture that met the inclusion criteria. Results: Mean (±SEM) age was 7.30±0.69 years for dogs with, and 4.77±0.37 years for dogs without femoral fracture. Age was positively associated with fracture (P=.022). Mean (±SEM) CFI was 1.80±0.09 for dogs with, and 1.98±0.04 for dogs without fracture. CFI was negatively associated with fracture (P=.045). Body weight, intraoperative fissure, cerclage use, implant size, position, and canal fill did not influence the occurrence of femoral fracture. Conclusions: Older dogs and dogs with lower CFI may be at increased risk for femoral fracture after porous‐coated cementless THA. Clinical Relevance: Risk factors exist for femoral fracture after cementless THA using porous‐coated implants, and should be critically evaluated during the patient selection. These risks should be weighed against the benefits of the system, and measures to minimize femoral fracture in at‐risk patients studied.     

Thoracoscopic Thoracic Duct Ligation and Thoracoscopic Pericardectomy for Treatment of Chylothorax in Dogs

Objective— To report the use of thoracoscopic thoracic duct ligation (TDL) and pericardectomy for treatment of chylothorax.
Study Design— Case series.
Animals— Dogs with chylothorax (n=12).
Methods— Dogs with secondary or idiopathic chylothorax had thoracoscopy performed in sternal recumbency through 3 portals in the caudal right hemithorax for TDL and were then repositioned in dorsal recumbency for pericardectomy. Portals were placed in the 5th and 7th intercostal spaces of the right hemithorax with 1 transdiaphragmatic portal in the right paraxiphoid position. Follow-up was performed by recheck examination or telephone interview to determine outcome.
Results— Seven dogs (58%) had idiopathic chylothorax; 6 dogs (85.7%) had complete resolution of their effusion, whereas only 2 of the 5 nonidiopathic dogs (40%) had complete resolution.
Conclusions— Thoracoscopy is minimally invasive, provides excellent observation, and allows for ligation of the thoracic duct in the caudal thorax. Patients with idiopathic chylothorax may have a better prognosis after TDL and pericardectomy than dogs with nonidiopathic chylothorax.
Clinical Relevance— Thoracoscopy for ligation of the thoracic duct and pericardectomy is an acceptable surgical technique for treatment of chylothorax.     

In Vitro Biomechanical Evaluation and Comparison of FiberWire,FiberTape, OrthoFiber,and Nylon Leader Line for Potential Use During Extraarticular Stabilization Of Canine Cruciate Deficient Stifles

Objective— To compare biomechanical properties of 3 new generation polyethylene sutures (FiberTape [FT], FiberWire [FW], and OrthoFiber [OF]) with nylon leader line (NL) for use during extraarticular fixation of cranial cruciate deficient stifles. Study Design— In vitro biomechanical testing of suture loops under monotonic tensile and cyclical loading until failure. Sample Population— Constructs of FT, FW, OF, and NL. Methods— Twenty loops of each of 12 combinations of fixation and suture had monotonic tensile and cyclical loading. Two knotting techniques (square knot [SQ], slip knot [SL]) and a crimp clamp (CR) system were evaluated. Elongation, stiffness, and strength of constructs was tested. The main effects of group, loop material, and their interaction were evaluated. Results— Knotted FT, FW, and OF had less elongation than knotted NL under monotonic tensile and cyclical loading. Under monotonic tensile loading, knotted FT and OF were stiffer than knotted NL. CR FT, CR FW, and CR OF were stiffer than CR NL and CR FT, CR FW, and CR OF were stiffer than knotted FT, FW, and OF. FW and OF knotted loops were weaker than knotted NL. CR FT was stronger than CR NL. CR FT and CR OF were weaker than knotted FT and OF. Conclusions— Polyethylene sutures are stronger, stiffer and elongate less than nylon leader. Crimping suture alters the biomechanical properties of the loop. Clinical Relevance— FW, FT, and OF may perform better in reconstructive procedures, where increased strength and stiffness are considered to be beneficial.