Surgical enlargement of the nasomaxillary aperture and transnasal conchotomy of the ventral conchal sinus: Two surgical techniques to improve sinus drainage in horses.

OBJECTIVE: To evaluate 2 surgical techniques for establishing and/or improving paranasal sinus drainage in cadaver heads and horses with sinusitis and evaluate the feasibility of postoperative transnasal sinus endoscopy. STUDY DESIGN: Ex vivo study (equine cadaver heads) and case series. SAMPLE POPULATION: Nine adult equine cadaver heads and 8 horses with recurrent sinusitis. METHODS: For the ex vivo study, the following procedures were performed on 9 cadaver heads: preoperative and postoperative computed tomography (heads 1-6), endoscopy-guided transnasal conchotomy of the ventral conchal sinus (TCVCS) and surgical enlargement of the nasomaxillary aperture (SENMAP) on opposite sides (heads 1-3), combined TCVCS and SENMAP on both sides (heads 4-9), evaluation of sinus drainage before and after surgery (heads 7-9), and postoperative transnasal endoscopy (heads 4-9). For the case series, 8 horses with secondary sinusitis were treated in standing position with SENMAP and/or TCVCS and postoperative transnasal endoscopy. RESULTS: Sinonasal communications were successfully created in all cadavers and affected live horses. Transnasal endoscopy of all sinuses except the middle conchal sinus was possible in heads 4-9 and in all clinical cases. Sinus drainage was improved (P = .028) by combining techniques. Blood loss in live horses ranged from 0.5-5.5 L (1.95 ± 1.5) per horse. Sinusitis resolved in all affected horses during follow-up of 3.2-25.5 months (13.5 ± 8.5). CONCLUSION: Transnasal conchotomy of the ventral conchal sinus and SENMAP consistently created large sinonasal communications, facilitating sinus endoscopy and improving sinus drainage. CLINICAL SIGNIFICANCE: Transnasal conchotomy of the ventral conchal sinus and SENMAP are viable options to treat horses with sinusitis and anatomical obstructions of the sinonasal communications.

Association between clinical history in the radiographic request and diagnostic accuracy of thorax radiographs in dogs: A retrospective case-control study.

BACKGROUND: The effect of clinical history on the interpretation of radiographs has been widely researched in human medicine. There is, however, no data on this topic in veterinary medicine. HYPOTHESIS/OBJECTIVES: Diagnostic accuracy would improve when history was supplied. ANIMALS: Thirty client-owned dogs with abnormal findings on thoracic radiographs and confirmation of the disease, and 30 healthy client-owned controls were drawn retrospectively. METHODS: Retrospective case-control study. Sixty radiographic studies of the thorax were randomized and interpreted by 6 radiologists; first, with no access to the clinical information; and a second time with access to all pertinent clinical information and signalment. RESULTS: A significant increase in diagnostic accuracy was noted when clinical information was provided (64.4% without and 75.2% with clinical information; P = .002). There was no significant difference in agreement between radiologists when comparing no clinical information and with clinical information (Kappa 0.313 and 0.300, respectively). CONCLUSIONS AND CLINICAL IMPORTANCE: The addition of pertinent clinical information to the radiographic request significantly improves the diagnostic accuracy of thorax radiographs of dogs and is recommended as standard practice.

Muscle Fibre Architecture of Thoracic and Lumbar Longissimus Dorsi Muscle in the Horse.

As the longissimus dorsi muscle is the largest muscle in the equine back, it has great influence on the stability of the spine and facilitates proper locomotion. The longissimus muscle provides support to the saddle and rider and thereby influences performance in the horse. Muscular dysfunction has been associated with back disorders and decline of performance. In general, muscle function is determined by its specific intramuscular architecture. However, only limited three-dimensional metrical data are available for the inner organisation of the equine longissimus dorsi muscle. Therefore, we aimed at investigating the inner architecure of the equine longissimus. The thoracic and lumbar longissimus muscles of five formalin-fixed cadaveric horse backs of different ages and body types were dissected layerwise from cranial to caudal. Three-dimensional coordinates along individual muscle fibre bundles were recorded using a digitisation tool (MicroScribe®), to capture their origin, insertion and general orientation. Together with skeletal data from computed tomography (CT) scans, 3D models were created using imaging software (Amira). For further analysis, the muscle was divided into functional compartments during preparation and morphometric parameters, such as the muscle fascicle length, pennation angles to the sagittal and horizontal planes, muscle volume and the physiological cross-sectional area (PCSA), were determined. Fascicle length showed the highest values in the thoracic region and decreased from cranial to caudal, with the cranial lumbar compartment showing about 75% of cranial fascicle length, while in most caudal compartments, fascicle length was less than 50% of the fascicle length in thoracic compartments. The pennation angles to the horizontal plane show that there are differences between compartments. In most cranial compartments, fascicles almost run parallel to the horizontal plane (mean angle 0°), while in the caudal compartment, the angles increase up to a mean angle of 38°. Pennation angles to the sagittal plane varied not only between compartments but also within compartments. While in the thoracic compartments, the fascicles run nearly parallel to the spine, in the caudal compartments, the mean angles range from 0-22°. The muscle volume ranged from 1350 cm3 to 4700 cm3 depending on body size. The PCSA ranged from 219 cm2 to 700 cm2 depending on the muscle volume and mean fascicle length. In addition to predictable individual differences in size parameters, there are obvious systemic differences within the muscle architecture along the longissimus muscle which may affect its contraction behaviour. The obtained muscle data lay the anatomical basis for a specific biomechanical model of the longissimus muscle, to simulate muscle function under varying conditions and in comparison to other species.