Mark C. Fuller

Ultrasound and computed tomography of the iliosacral lymphatic centre in dogs with anal sac gland carcinoma

In this prospective study, we hypothesized that computed tomography (CT) would identify more normal and abnormal iliosacral lymph nodes (LNs) than abdominal ultrasound in dogs with anal sac gland carcinoma (ASGC). Twelve client-owned dogs with ASGC but without distant metastasis were enrolled. Abdominal ultrasound and contrast-enhanced CT scans of the abdomen were obtained. Iliosacral LNs were counted and assessed for location, laterality and size. Significantly (P < 0.00001) more iliosacral LNs were identified with CT (61) than ultrasound (30), including significantly (P = 0.00012) more medial iliac LNs with CT (33) than ultrasound (19). There was no difference in number of internal iliac LNs identified with CT versus ultrasound. Significantly (P = 0.000061) more sacral LNs were identified with CT (15) than ultrasound (0). Ultrasound identified slightly more (7) abnormal iliosacral LNs than CT (5). Contrast CT was able to identify more normal but not more abnormal LNs than ultrasound.

Evaluation of the radiographic infrapatellar fat pad sign of the contralateral stifle joint as a risk factor for subsequent contralateral cranial cruciate ligament rupture in dogs with unilateral rupture: 96 cases (2006-2007)

OBJECTIVE To determine prevalence of the contralateral radiographic infrapatellar fat pad sign and contralateral radiographic degenerative sign (degenerative changes) and evaluate both signs as risk factors for subsequent contralateral cranial cruciate ligament (CrCL) rupture in dogs with unilateral CrCL rupture. DESIGN Retrospective cohort study. ANIMALS 96 dogs with unilateral CrCL rupture and 22 dogs with bilateral CrCL rupture. PROCEDURES Dogs with unilateral CrCL rupture were classified as having normal (n = 84) or abnormal (12) contralateral stifle joints on the basis of joint palpation. Associations between potential predictive variables and rates of subsequent contralateral CrCL rupture were evaluated. RESULTS Of the 84 dogs with unilateral CrCL rupture in which the contralateral stifle joint was palpably normal, 29 (34.5%) had a contralateral fat pad sign and 31 (36.9%) had a degenerative sign. All dogs with unilateral CrCL rupture in which the contralateral stifle joint was palpably abnormal had a contralateral fat pad sign and degenerative sign. The contralateral fat pad sign was the most important risk factor for subsequent rupture of the contralateral CrCL. For dogs with unilateral CrCL rupture and palpably normal contralateral stifle joint with and without a contralateral fat pad sign, median time to subsequent rupture was 421 and 1,688 days, respectively, and the 3-year probability of subsequent rupture was 85.3% and 24.9%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Bilateral stifle joint radiography should be performed for all dogs with CrCL rupture. Bilateral stifle joint arthroscopy should be considered for dogs with a contralateral fat pad sign.

Laparoscopic Extirpation of the Medial Iliac Lymph Nodes in Normal Dogs

OBJECTIVE To describe a surgical technique for laparoscopic medial iliac lymph node (MILN) extirpation, and to describe the quality of biopsy specimens obtained. DESIGN Experimental study. ANIMALS Purpose-bred male hound-mix research dogs (n = 8). METHODS Dogs were randomized to groups of left or right-sided laparoscopic surgical approaches. Three transperitoneal portals were established with the dogs in lateral recumbency, and ipsilateral MILN dissection was achieved under CO2 pneumoperitoneum using a vessel-sealing device. RESULTS MILN ipsilateral to the approach were successfully identified and removed laparoscopically in 8 dogs. Observed complications included mild to moderate hemorrhage that was controlled laparoscopically in 4 dogs, and tearing of the MILN capsule during retraction and dissection in 3 dogs. No other major complications occurred and all dogs recovered uneventfully. Areas of either minor peripheral (9/9) or central (4/9) pinch artifact affected a median percentage of 5% of surface area (range, 5-30%) of bisected lymph nodes. CONCLUSIONS Laparoscopic MILN extirpation is feasible in dogs with normal MILN and may serve as a minimally invasive approach for excisional biopsy in the diagnostic staging of canine onocologic patients with normal-sized MILN. This lateral laparoscopic approach allows dissection of the ipsilateral MILN but precludes removal of the contralateral MILN. Minimal handling of the lymph node during dissection and removal is required to reduce the risk of capsular tear, or introduction of possible histologic artifact by tissue crush that may impact diagnosis.

Outcome of nonunion fractures in dogs treated with fixation, compression resistant matrix, and recombinant human bone morphogenetic protein-2

OBJECTIVES To report the use of compression resistant matrix (CRM) infused with recombinant human bone morphogenetic protein (rhBMP-2) prospectively in the healing of nonunion long-bone fractures in dogs. METHODS A longitudinal cohort of dogs that were presented with nonunion fractures were classified and treated with CRM soaked with rhBMP-2 and fracture fixation. They were followed with serial radiographs and evaluated for healing times and complications according to the time frame and definitions previously established for orthopaedic clinical cases. RESULTS Eleven nonunion fractures in nine dogs were included. Median healing time was 10 weeks (range: 7-20 weeks). Major perioperative complications due to bandage morbidity were encountered in two of 11 limbs and resolved. All other complications were minor. They occurred perioperatively in eight of 11 limbs. Minor follow-up complications included short-term in one of two limbs, mid-term in one of three, and long-term in four of five limbs. Nine limbs returned to full function and two limbs returned to acceptable function at the last follow-up. CLINICAL SIGNIFICANCE Nonunion fractures given a poor prognosis via standard-of-care treatment were successfully repaired using CRM with rhBMP-2 accompanying fixation. These dogs, previously at high risk of failure, returned to full or acceptable function.

Indirect computed tomographic lymphography for iliosacral lymphatic mapping in a cohort of dogs with anal sac gland adenocarcinoma: Technique description

Sentinel lymph node mapping can help to direct surgical oncologic staging and metastatic disease detection in patients with complex lymphatic pathways. We hypothesized that indirect computed tomographic lymphography (ICTL) with a water-soluble iodinated contrast agent would successfully map lymphatic pathways of the iliosacral lymphatic center in dogs with anal sac gland carcinoma, providing a potential preoperative method for iliosacral sentinel lymph node identification in dogs. Thirteen adult dogs diagnosed with anal sac gland carcinoma were enrolled in this prospective, pilot study, and ICTL was performed via peritumoral contrast injection with serial caudal abdominal computed tomography scans for iliosacral sentinel lymph node identification. Technical and descriptive details for ICTL were recorded, including patient positioning, total contrast injection volume, timing of contrast visualization, and sentinel lymph nodes and lymphatic pathways identified. Indirect CT lymphography identified lymphatic pathways and sentinel lymph nodes in 12/13 cases (92%). Identified sentinel lymph nodes were ipsilateral to the anal sac gland carcinoma in 8/12 and contralateral to the anal sac gland carcinoma in 4/12 cases. Sacral, internal iliac, and medial iliac lymph nodes were identified as sentinel lymph nodes, and patterns were widely variable. Patient positioning and timing of imaging may impact successful sentinel lymph node identification. Positioning in supported sternal recumbency is recommended. Results indicate that ICTL may be a feasible technique for sentinel lymph node identification in dogs with anal sac gland carcinoma and offer preliminary data to drive further investigation of iliosacral lymphatic metastatic patterns using ICTL and sentinel lymph node biopsy.

Outcome of laparoscopic adrenalectomy for resection of unilateral noninvasive adrenocortical tumors in 11 cats

Objective: To describe the technique and outcomes of laparoscopic adrenalectomy (LA) in cats with adrenocortical neoplasia. Study design: Retrospective case series. Animals: Eleven client‐owned cats with unilateral adrenal tumors. Methods: Medical records of cats that underwent LA for unilateral functional adrenal tumors at 3 veterinary teaching hospitals were reviewed. Data collected included signalment, clinical signs, physical examination findings, diagnostic imaging results, preoperative laboratory tests, laparoscopic port placement and techniques, duration of anesthesia and surgery, complications, concomitant procedures, need for conversion to an open celiotomy, histopathological diagnosis, and postoperative survival. Results: Eleven cats were included, 5 with right‐sided and 6 with left‐sided tumors. Tumors were aldosterone‐secreting (n = 8), progesterone‐secreting (n = 2), or testosterone‐secreting (n = 1). Adrenalectomy was successfully performed in all 11 cats although 4 cases required conversion to an open celiotomy, due to poor visualization (n = 2), close adherence of the tumor to the caudal vena cava (n = 1), and inability to maintain adequate pneumoperitoneum (n = 1). Ten of the 11 cats were discharged from the hospital, with a median survival time of 803 days (range 467‐1123 days). One cat died from severe pancreatitis and cardiogenic pulmonary edema. Conclusion: Adrenalectomy can be performed in cats via laparoscopy but is technically challenging, and associated with a relatively high conversion rate (36%).

Laparoscopic Adrenalectomy for Removal of Unilateral Noninvasive Pheochromocytomas in 10 Dogs

OBJECTIVE To report the surgical technique and outcome of dogs undergoing laparoscopic adrenalectomy for removal of unilateral noninvasive pheochromocytoma. STUDY DESIGN Retrospective case series. ANIMALS Dogs with unilateral noninvasive adrenal tumors (n=10). METHODS Medical records of dogs that underwent laparoscopic adrenalectomy for histologically confirmed pheochromocytoma were reviewed. Dogs were positioned in lateral recumbency with the table tilted up to create a semi-sternal position. Three or 4 ports were used and dissection of the mass proceeded using a combination of laparoscopic instrumentation, bipolar vessel-sealing devices, and in some cases monopolar electrosurgical probes. Conversion rate, complications, surgical time, hospitalization time, and long-term follow-up were recorded. RESULTS The procedure was completed without the need for conversion in 9 of 10 dogs. In 1 dog, hemorrhage obscured the visual field and conversion to an open approach was elected. In 5 cases, a 3-port approach was used, and in 5 cases, a 4th port was placed. Median surgical time was 105 minutes (range, 65-250). Intraoperative complications included 1 splenic laceration. Postoperatively, 1 dog developed gastric dilatation-volvulus. All dogs were discharged from the hospital. Median follow-up time was 16.0 months (range, 6.9-38.0). CONCLUSION With careful case selection, laparoscopic adrenalectomy for resection of pheochromocytoma was feasible and could be performed efficiently by experienced laparoscopic surgeons.

Pilot study of the suitability of dorsal vulval skin as a transposition flap: vascular anatomic study and clinical application.

OBJECTIVE To identify the blood supply to the vulval fold and adjacent skin, and evaluate it as a transposition flap for closing perineal wounds in dogs. STUDY DESIGN Prospective study. ANIMALS OR SAMPLE POPULATION Five female canine cadavers and 2 cases referred for excision of mast cell tumors adjacent to the vulva. METHODS Dissection was performed to identify the vascular supply to the vulval fold in two cadavers following arterial injection of red latex and methylene blue, respectively. In three cadavers, barium sulfate mixed 1:1 with water was injected into the terminal aorta. The vulval fold and surrounding perineal skin was excised and radiographed. Transposition flaps using the vulval fold and adjacent skin were used to close skin defects in two dogs presented for wide excision of mast cell tumors situated ventro-lateral and dorso-lateral to the vulva, respectively. RESULTS The vulval fold and adjacent skin was perfused bilaterally by branches of the ventral perineal and external pudendal arteries, which entered dorsally and ventrally, respectively. As incisions used to create a transposition flaps from the skin surrounding the vulval fold transect these vessels, the flap is dependent on the sub-dermal plexus for survival. There was 100% survival of transposition flaps in the 2 clinical cases and healing proceeded uneventfully with acceptable cosmetic and functional results. CONCLUSIONS The vulval fold and surrounding skin can be used as a subdermal plexus flap to close large perineal defects in dogs. CLINICAL RELEVANCE Availability of a defined local skin flap will improve treatment of diseases resulting in large perineal skin defects in female dogs.

Urate urolithiasis and hyperuricosuria in a Weimaraner, secondary to the SLC2A9 transporter defect

In this case, we describe a middle-aged, male Weimaraner that presented with upper and lower urinary tract urate urolithiasis. The dog required surgical intervention to remove the obstruction in the right ureter as well as medical management to prevent recurrent calculi. While the genetic defect that causes this disease in Dalmatians is well known among clinicians, this is the first clinical case documented in the Weimaraner breed. This dog shared the same SLC2A9 mutation as Dalmatians, which likely predisposed this dog to developing urate calculi. For dogs where urate uroliths are suspected on imaging studies, genetic testing may be warranted to help elucidate any predisposing factors for stone formation. Knowing the aetiology of the stone formation will alter the therapeutic approach for treatment and management.