Pierre Moissonnier

Indwelling double pigtail ureteral stent combined or not with surgery for feline ureterolithiasis: complications and outcome in 15 cases.

Ureteral obstruction secondary to ureterolithiasis in cats is a challenging situation. Ureteral stenting has recently been introduced to prevent complications that often occurred after ureterotomy or other invasive surgeries. The purpose of this study is to describe the stenting technique and perioperative difficulties, as well as long-term outcome and complications with ureteral stenting in 12 cats with ureteroliths. Fifteen 2.5 Fr soft double pigtail multi-fenestrated ureteral stents were placed in an anterograde fashion under open surgical approaches and with fluoroscopic guidance in 12 cats. Nine cats received a unilateral stent and three received bilateral stents. Ureterotomy or ureteral resection and end-to-end anastomosis were performed in three and four cases, respectively. In six cats, papillotomy was performed to facilitate dilatator and stent placement. All cats recovered well from the surgical procedure, except one cat, which died during the anaesthesia recovery period. Postoperative complications included dysuria (three cases, diagnosed at 15 days, 1 month and 3 months, respectively), urinary tract infection (one case, 1 month after surgery), stent migration requiring stent replacement (one case, 19 months after surgery) and stent obstruction requiring stent removal (three cases with previously end-to-end anastomosis between 2 and 8 months after surgery). Nine cats (75%) were alive at a mean follow-up of 453 ± 194 (123–720) days. The median survival time was >415 days. Stent placement appeared to be a valuable and safe option for treating ureteral obstruction in cats. However, periodic and long-term monitoring of stents is warranted.

Thoracic kyphosis associated with hemivertebra.

Objective To radiographically assess the influence of thoracic hemivertebra on kyphosis and neurologic status in 45 dogs. Study Design Case series. Animals French Bulldogs without neurologic signs (n = 41) and 4 dogs with compressive spinal cord disease associated with hemivertebra. Methods Thoracic spinal radiographs were divided into 3 groups: 1 = dogs with no hemivertebra, 2 = dogs with hemivertebra but no associated neurologic signs, and 3 = dogs with hemivertebra associated with clinical signs. Vertebral canal height, vertebral column angle, and the step between 2 adjacent vertebrae were measured in each group. Results Vertebral canal height was not significantly different in the 3 groups; however, mean vertebral column angle was significantly (P < .001) different between groups 1 (178°) and 2 (169°), and group 3 (133°). Median cranial step was significantly different between groups (P < .001): 0 mm (group 1), 0.3 mm (group 2), 3 mm (group 3). Conclusions Vertebral canal height does not differ between normal dogs and dogs with thoracic hemivertebra. There is an important association between neurologic signs and kyphosis and subluxation. Clinical Relevance Vertebral realignment without vertebral canal opening could lead to spinal cord decompression in dogs affected by thoracic hemivertebra.OBJECTIVE To radiographically assess the influence of thoracic hemivertebra on kyphosis and neurologic status in 45 dogs. STUDY DESIGN Case series. ANIMALS French Bulldogs without neurologic signs (n = 41) and 4 dogs with compressive spinal cord disease associated with hemivertebra. METHODS Thoracic spinal radiographs were divided into 3 groups: 1 = dogs with no hemivertebra, 2 = dogs with hemivertebra but no associated neurologic signs, and 3 = dogs with hemivertebra associated with clinical signs. Vertebral canal height, vertebral column angle, and the step between 2 adjacent vertebrae were measured in each group. RESULTS Vertebral canal height was not significantly different in the 3 groups; however, mean vertebral column angle was significantly (P < .001) different between groups 1 (178°) and 2 (169°), and group 3 (133°). Median cranial step was significantly different between groups (P < .001): 0 mm (group 1), 0.3 mm (group 2), 3 mm (group 3). CONCLUSIONS Vertebral canal height does not differ between normal dogs and dogs with thoracic hemivertebra. There is an important association between neurologic signs and kyphosis and subluxation. CLINICAL RELEVANCE Vertebral realignment without vertebral canal opening could lead to spinal cord decompression in dogs affected by thoracic hemivertebra.

Surgical treatment of a vertebral fracture associated with a haematogenous osteomyelitis in a dog.

A seven-month-old Rottweiler was referred for a diagnosed femoral neck fracture and a suspected vertebral fracture. The simplified neurological examination revealed an acute paraplegia. A discospondyilitis associated with a pathologic fracture of Th11 and a spinal compression, and a haematogenous epiphysitis of the femoral neck were diagnosed based on radiographic and computed tomographic examinations. The vertebral fracture was stabilised using screws and polymethylmetacrylate with gentamycin by a lateral intercostal approach. The dog was able to walk seven days later. A femoral head and neck ostectomy was performed two weeks later. Staphylococcus intermedius was isolated from both sites, which confirmed the diagnosis. The dog was treated with cephalexin (30 mg/kg/d) for six weeks. A telephone interview with owners indicated that no more clinical signs were present four months after the second surgery. Discospondylitis associated with haematogenous osteomyelitis has only been reported in two cases. Paraplegia is an unusual clinical presentation for discospondylitis. The lateral approach (which allowed a direct access to the infected site) and the technique (screws associated with antibiotic-impregnated cement) are unique for surgical treatment of discospondylitis. Although applying cement to an infected area may pose a risk, antibiotic-loaded cement is successfully used in the treatment of chronic osteomyelitis in humans.

Anatomical and safety considerations in establishing portals used for canine elbow arthroscopy

OBJECTIVES To describe the relationship of the major muscular, ligamentous and neurovascular structures in relation to standard medial elbow arthroscopic portals used in dogs, and to evaluate their potential iatrogenic lesions. DESIGN Anatomical study using 20 canine cadaveric elbows. METHODS Arthroscopic explorations were performed using medial portals. Three 4 mm orthopaedic pins were introduced in place of the arthroscope, egress canula and instrumental portals. Limbs were dissected. Distances between pins and neurovascular structures were measured. Muscle, ligament and cartilage lesions were recorded. RESULTS Minimal muscular lesions were observed. No ligament injury was evidenced. Superficial iatrogenic cartilage lesions were observed in three joints. The arthroscopic portal was 23.1 mm (range: 16 to 28.5 mm) caudal to the brachial artery, 21.0 mm (13-30.5 mm) caudal to the median nerve, and 4.0 mm (1-7 mm) cranial to the ulnar nerve. The instrumental portal was 16.3 (9-24 mm) caudal to the brachial artery, 13.5 mm (7-24.5 mm) caudal to the median nerve, and 11.8 (8-18 mm) cranial to the ulnar nerve. The egress portal was 21.4 mm (12-37 mm) caudal to the ulnar nerve. CONCLUSIONS AND CLINICAL RELEVANCE The study confirmed the safety of elbow medial arthroscopic portals. Care must be taken when placing the camera portal so as to avoid injury of the ulnar nerve. Should extensive intra-articular procedures be needed, manipulation of instruments should be done cautiously in the cranio-medial compartment of the joint due to the proximity of the median nerve to the capsule.

Lateral orbitotomy for treatment of an orbital abscess in a dog

A two-year-old Jack Russell terrier was diagnosed with a retrobulbar abscess and orbital cellulitis. The diagnosis was confirmed by ultrasound, magnetic resonance imaging examination and ultrasound-guided fine-needle aspiration. Transoral ventral drainage was attempted but was unsuccessful. The abscess was successfully treated by open drainage through a lateral orbitotomy. Despite the exposure of the orbital structures, the orbital soft tissues healed by second intention without further complications. The open drainage was well tolerated and resulted in immediate reduction of inflammation and pain, allowing a quick recovery. This report describes the diagnosis and, surgical management and the long-term (3 years) follow-up of an unusual case of orbital abscess associated with diffuse periorbital cellulitis successfully treated by open drainage through a lateral orbitotomy.

Use of preoperative computed tomography for surgical treatment of recurrent draining tracts

OBJECTIVES To evaluate a rational decision-making approach based on preoperative computed tomography for surgical planning in dogs and cats with recurrent draining tracts. METHODS Retrospective evaluation of case records of animals that underwent preoperative computed tomography for surgical treatment of thoracic/abdominal recurrent draining tracts. Cases were classified according to whether a source of inflammation and/or infection, in particular foreign bodies, was identified (group 1), suspected (group 2) or neither identified nor suspected (group 3) at computed tomography. Surgery consisted of removal of the source of inflammation and/or infection (group 1), debridement or abscess drainage (group 2) or en bloc resection of diseased tissues (group 3). Clinical outcome was evaluated at least 12 months after surgery. RESULTS A source of inflammation and/or infection was found in 100% (8 of 8), 41% (7 of 17) and 25% (3 of 12) of cases in groups 1, 2 and 3, respectively. Recurrent draining tracts resolved in 100% (8 of 8), 94% (16 of 17) and 92% (11 of 12) of cases in groups 1, 2 and 3, respectively. CLINICAL SIGNIFICANCE The proposed strategy provided a 95% (35 of 37) cure rate, after a single procedure in 81% (30 of 37) of cases. Recovery of a foreign body at surgery was not a prerequisite for the resolution of the recurrent draining tracts.

Computed tomographic study of the optimal safe implantation corridors in feline thoraco-lumbar vertebrae

OBJECTIVE To define the implantation corridors in feline thoraco-lumbar vertebrae (T10-L7) using computed tomography (CT) for optimal safe placement of the implants (screws/pins) in spinal column stabilization. STUDY DESIGN Computed tomographic study. MATERIALS AND METHODS Computed tomography images of feline spinal column (n = 10) were used to define the optimal safe implantation corridors (OSIC) in the transverse plane. The OSIC were defined as corridors allowing the greatest amount of bone purchase with safe margins for implantation of the bicortical implants. They were characterized by their insertion point, optimal angle (from the midsagital plane), maximum and minimum safe angles (from the same insertion points), length, and width. RESULTS The OSIC are located within the vertebral bodies. Insertion points were situated at the level of the vertebro-costal joint or the base of the transverse process of the vertebral body for thoracic and lumbar vertebrae, respectively. The mean optimal angle of the OSIC was 90.2° with a maximum deviation angle from optimal angle of 10° dorsally and 8.8° ventrally in thoracic vertebrae, and 90.5° with a maximum deviation angle from the optimal angle of 8.4° dorsally and 7.6° ventrally in lumbar vertebrae. CONCLUSION AND CLINICAL RELEVANCE Corridors drilled in the vertebral body perpendicular to the midsagital plane (90°) or with a small angle (≤10°) of deviation from the optimal angle provide an optimal safe placement of bicortical implants. However, perpendicular implant placement may not always be feasible due to surrounding soft tissue structures.

Cross-neurotization of the caudal brachial plexus with the contralateral C-8 ventral nerve branch in the cat. Potential surgical applications, effects of graft collection on the healthy donor limb and results.

Contralateral transfer of the right, eighth ventral nerve branch (C8) (C8 cross-transfer - C8CT) was performed in 6 adult cats, in which the caudal part of the left brachial plexus (C8 and T1) had been severed, in order to mimic nerve root avulsion. Clinical and electrophysiological parameters, muscle contraction force measurements and histology were used to evaluate the effects of the surgery in a 14- to 36-month follow-up. The right forelimb (donor side) was clinically normal (no lameness) in all the cats at the end of the study. Electromyography performed 14 days after surgery revealed denervation fibrillation potentials in both forelimbs. Fibrillation potentials disappeared in all the cats at the end of the study. Direct stimulation of the right C8 ventral branch induced motor and sensory evoked potentials in the left limb muscles in all the cats. The left to right contraction ratio of the extensor carpi radialis muscle was approximately 1. This experimental study demonstrates that C8CT enables re-innervation of the contralateral brachial plexus and allows the establishment of new functional neuromuscular units. This can in turn enable the restoration of function, and could potentially lead to partial recovery after caudal brachial plexus avulsion in the cat.

Surgical repair of thoraco-lumbar vertebral fracture-luxations in eight cats using screws and polymethylmethacrylate fixation

OBJECTIVE To report our clinical experience in the surgical treatment of feline thoraco-lumbar vertebral fracture-luxations using optimal safe implantation corridors as previously described in vitro. STUDY DESIGN Retrospective clinical study. MATERIALS AND METHODS Medical records and radiographs of cats with vertebral fracture-luxations stabilized by screws and polymethylmethacrylate (PMMA) using optimal safe implantation corridors between 2009 and 2011 were reviewed. For each patient the data included: signalment, cause of vertebral fracture-luxations, presence of concurrent injuries, pre- and postoperative neurological grade, surgical treatment, imaging findings, and clinical outcome with short-term (2 weeks) and long-term (12 months) follow-up. RESULTS Eight cats with vertebral fracture-luxations involving the lumbar (L)(n = 5), the thoracic (T) spinal segments (n = 2), or the thoraco-lumbar junction (n = 1) were included in the study. Screws and PMMA were used bilaterally in five cats and unilaterally in three cats. No surgical intra-operative complications using the defined corridors were recorded. Implant failure followed by spontaneous recovery was recorded in one case. Two cats died in the postoperative period (≤ 4 days). The short-term and long-term clinical outcome was excellent in four out of eight cats and satisfactory in two out of eight cats. CONCLUSION AND CLINICAL RELEVANCE This pilot study demonstrates the clinical applicability of optimal safe implantation corridors for stabilization of feline thoraco-lumbar vertebral fracture-luxations with screws and PMMA. This technique can be used with limited risks of iatrogenic injuries for stabilization of vertebral fracture-luxation localized between T11-L4.

C8 cross transfer for the treatment of caudal brachial plexus avulsion in three dogs

OBJECTIVE To evaluate the cervical nerve 8 cross-transfer technique (C8CT) as a part of surgical treatment of caudal brachial plexus avulsion (BPA) in the dog. STUDY DESIGN Case series. ANIMALS Client-owned dogs suspected to have caudal BPA based on neurological examination and electrophysiological testing (n = 3). METHODS The distal stump of the surgically transected contralateral C8 ventral branch (donor) was bridged to the proximal stump of the avulsed C8 ventral branch (recipient) and secured with 9-0 polypropylene suture under an operating microscope. A carpal panarthrodesis was performed on the injured limb after C8CT. RESULTS Surgical exploration confirmed avulsion of nerve roots C7, C8, and T1 in all cases. There was no evidence of an iatrogenic effect on the donor forelimb. Gradual improvement in function of the affected forelimb occurred in all dogs, with eventual recovery of voluntary elbow extension. Reinnervation was evident in EMG recordings 6 months postoperatively in all three dogs. Stimulation of the donor C8 ventral branch led to motor evoked potentials in the avulsed side triceps brachialis and radial carpus extensor muscles. Variable functional outcome was observed in the 3 dogs during clinical evaluation 3-4 years after surgery. Digital abrasion wounds, distal interphalangeal infectious arthritis, and self-mutilation necessitated distal phalanx amputation of digits 3 and 4 in 2 dogs. CONCLUSION C8CT provided partial reconnection of the donor C8 ventral branch to the avulsed brachial plexus in the 3 dogs of this series. Reinnervation resulted in active elbow extension and promoted functional recovery in the affected limb.