Michele A. Steffey

Evaluation of short-term outcome after lung lobectomy for resection of primary lung tumors via video-assisted thoracoscopic surgery or open thoracotomy in medium- to large-breed dogs

OBJECTIVE To describe clinicopathologic features of dogs that underwent lung lobectomy for resection of primary lung tumors via video-assisted thoracoscopic surgery (VATS) or open thoracotomy (OT) and to compare short-term outcomes for dogs following these procedures. DESIGN Retrospective cohort study. ANIMALS 46 medium- to large-breed dogs with primary lung tumors. PROCEDURES Medical records of dogs that underwent a lung lobectomy via VATS (n = 22) or OT (24) for resection of primary lung tumors between 2004 and 2012 were reviewed. Dogs were included if they weighed > 10 kg (22 lb) and resection of a primary lung tumor was confirmed histologically. Tumor volumes were calculated from preoperative CT scans where available. Surgical time, completeness of excision, time in the ICU, indwelling thoracic drain time, postoperative and total hospitalization time, incidence of major complications, and short-term survival rate were evaluated. RESULTS VATS was performed with a 3-port (n = 12) or 4-port (10) technique and 1-lung ventilation (22). In 2 of 22 (9%) dogs, VATS was converted to OT. All dogs survived to discharge from the hospital. There were no significant differences between the VATS and OT groups with regard to most variables. Surgery time was significantly longer for VATS than for OT (median, 120 vs 95 minutes, respectively). CONCLUSIONS AND CLINICAL RELEVANCE In medium- to large-breed dogs, short-term outcomes for dogs that underwent VATS for lung lobectomy were comparable to those of dogs that underwent OT. Further studies are required to evaluate the effects of surgical approach on indices of postoperative pain and long-term outcomes.

Evaluation of Laparoscopic‐Assisted Ovariohysterectomy for Treatment of Canine Pyometra

OBJECTIVE To describe a technique for treating pyometra in dogs using a 3-portal laparoscopic-assisted ovariohysterectomy (LAOVH) and evaluate outcome. STUDY DESIGN Retrospective case series. ANIMALS Dogs (n = 12). METHODS Dogs with open or closed-cervix pyometra with moderately sized (1-4 cm) uterine horn diameters based on preoperative ultrasonography and no evidence of perforation were included in the study. A 3-portal technique for LAOVH was used. A wound retraction device was inserted into the caudal portal after enlargement of the incision to 3-4 cm to simplify removal of the uterus with minimal tension. RESULTS Twelve dogs (median weight, 23.3 kg; range, 2.1-46.0 kg) met the inclusion criteria. Median uterine diameter was 3.0 cm (range, 1.2-4.0 cm). Median surgical time for LAOVH was 107 minutes (range, 82-120 minutes). Complications included mild hemorrhage from the uterine vessels in 1 dog during uterine removal through the wound retraction device and intra-abdominal uterine rupture in 1 dog which necessitated conversion to an open approach. All dogs recovered from surgery and were discharged. CONCLUSIONS LAOVH can be used for treatment of select cases of canine pyometra. Careful case selection is mandatory to improve success and minimize conversion to an open approach. Gentle handling of the reproductive organs is imperative to avoid iatrogenic uterine rupture.

Evaluation of in vivo behavior of ameroid ring constrictors in dogs with congenital extrahepatic portosystemic shunts using computed tomography.

OBJECTIVE To evaluate the in vivo pattern of ameroid constrictor closure of congenital extrahepatic portosystemic shunts in dogs. STUDY DESIGN Prospective study. ANIMALS Dogs (n = 22) with congenital extrahepatic portosystemic shunts. METHODS Contrast-enhanced computed tomography was performed immediately before, and at least 8 weeks after placement of ameroid ring constrictors. Plastic-encased ameroid constrictors were used in 17 dogs and metal constrictors in 5 dogs. Presence of residual flow through the portosystemic shunt, additional anomalous vessels, acquired shunts and soft tissue associated with the ameroid constrictor was recorded. Postoperative internal diameter was recorded for the 17 plastic constrictors. Correlations between internal diameter and pre- and postoperative serum protein concentration were analyzed. RESULTS No ameroid constrictor closed completely: shunt occlusion was always dependent on soft tissue within the ameroid ring. Residual flow through the shunt was present in 4 dogs (18%), although this caused persistent elevation of shunt fraction in only 1 dog (dog 8). The change in ameroid constrictor internal diameter was not significantly correlated with serum protein concentration. CONCLUSIONS Complete shunt occlusion after AC placement is usually dependent on soft tissue reaction. Ameroid constrictors ≥5 mm diameter may not promote complete shunt occlusion.

Outcome in dogs with surgically resected oral fibrosarcoma (1997-2008).

Oral fibrosarcoma (FSA) is a common oral tumour in dogs, and historically reported survival times after surgical excision range from 7.0 to 12.2 months with local recurrence rates of 32-57%. The purpose of this retrospective study was to report outcome in a cohort of dogs with oral FSA treated with surgical excision with or without adjuvant radiation therapy. Twenty-nine dogs with a histological diagnosis of FSA arising from the oral cavity that underwent surgical resection of their oral FSA were included in this study. Twenty-one dogs were treated with surgical excision alone and eight dogs with both surgery and radiation therapy. The median progression-free interval was >653 days. The median survival time was 743 days. The 1- and 2-year survival rates were 87.7 and 57.8%, respectively. Seven (24.1%) dogs developed local recurrence. Seven dogs (24.1%) developed metastasis.

Comparison of perioperative morbidity and mortality rates in dogs with noninvasive adrenocortical masses undergoing laparoscopic versus open adrenalectomy

OBJECTIVE To describe the clinicopathologic features of a cohort of dogs with adrenocortical masses that underwent laparoscopic adrenalectomy and to compare perioperative morbidity and mortality rates in these dogs with rates for dogs that underwent open adrenalectomy for resection of similarly sized (maximal diameter, ≤ 5 cm) adrenocortical masses. DESIGN Retrospective case series. ANIMALS 48 client-owned dogs that underwent laparoscopic (n = 23) or open (25) adrenalectomy for noninvasive tumors (ie, tumors that did not invade the vena cava or other surrounding organs). Procedures-Medical records were reviewed. History, clinical signs, physical examination findings, clinicopathologic findings, imaging results, and surgical variables were recorded. A 3- or 4-port approach was used for laparoscopic adrenalectomy. Surgical time, perioperative complications, postoperative and overall hospitalization times, and perioperative deaths were recorded and compared between groups. RESULTS The surgical method for 1 dog was converted from a laparoscopic to an open approach. Perioperative death occurred in no dogs in the laparoscopic group and 2 dogs in the open adrenalectomy group. Surgical time was shorter for laparoscopic (median, 90 minutes; range, 40 to 150 minutes) than for open (median, 120 minutes; range, 75 to 195 minutes) adrenalectomy. Laparoscopic adrenalectomy was associated with shorter hospitalization time and more rapid discharge from the hospital after surgery, compared with the open procedure. CONCLUSIONS AND CLINICAL RELEVANCE With careful patient selection, laparoscopic adrenalectomy was associated with a low complication rate and low conversion rate for resection of adrenocortical masses as well as shorter surgical and hospitalization times, compared with open adrenalectomy.

Correlation Between Liver Volume, Portal Vascular Anatomy, and Hepatic Perfusion in Dogs With Congenital Portosystemic Shunt Before and After Placement of Ameroid Constrictors

OBJECTIVE To correlate changes in hepatic volume, hepatic perfusion, and vascular anatomy of dogs with congenital extrahepatic portosystemic shunts, before and after attenuation with an ameroid constrictor. STUDY DESIGN Prospective study. ANIMALS Dogs (n = 22) with congenital extrahepatic portosystemic shunts. METHODS CT angiography and perfusion scans were performed before and after attenuation of a portosystemic shunt with an ameroid constrictor. Changes in hepatic volume, hepatic perfusion, and vascular anatomy were measured. Portal scintigraphy was performed in 8 dogs preoperatively and 22 dogs postoperatively. RESULTS Dogs with smaller preoperative liver volumes had greater increases in liver volume postoperatively compared with those with larger preoperative liver volumes. Hepatic arterial fraction was increased in dogs preoperatively and returned to normal range after shunt attenuation, and was correlated with increase in liver size and decreased shunt fraction. Three dogs with no visible portal vasculature preoperatively developed portal branches postoperatively. CONCLUSIONS Dogs with smaller preoperative liver volumes had the largest postoperative increase in liver volume. Hepatic arterial perfusion and portal scintigraphy correlate with liver volume and are indicators of successful shunt attenuation. Dogs without visible vasculature on CT angiography had visible portal vasculature postoperatively.

Video-Assisted Thoracoscopic Extirpation of the Tracheobronchial Lymph Nodes in Dogs.

OBJECTIVE To describe a technique for video-assisted thoracoscopic surgery (VATS) extirpation of the tracheobronchial lymph nodes (TBLN), 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-sided or right-sided VATS approaches. One lung ventilation was used and TBLN dissection was achieved using a vessel-sealing device. RESULTS TBLNs ipsilateral to the approach were successfully identified and removed thoracoscopically in 7 dogs. A 3-port technique was used in 6 dogs and 4 ports were used in 2 dogs. Observed complications included mild-moderate hemorrhage from the perinodal tissue controlled thoracoscopically (n = 2), inability to locate any TBLN (1), and difficulty achieving or maintaining one-lung ventilation (4). No other major complications occurred and all dogs recovered uneventfully. Median percentage surface area of the bisected lymph nodes affected by crush artifact was 20% (range, 0-40%). Areas of crush artifact were present in central (7/11) and peripheral (9/11) locations. CONCLUSIONS AND CLINICAL RELEVANCE Thoracoscopic TBLN extirpation is a feasible technique in dogs with normal TBLN and may be useful for obtaining more detailed staging on microscopic disease status in oncologic patients with normal-sized TBLNs. Further study is warranted to determine the feasibility and limitations of this technique in clinical patients with overt lymphadenopathy.

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.

Laparoscopic treatment of ovarian remnant syndrome in dogs and cats: 7 cases (2010–2013)

OBJECTIVE To describe the technique and evaluate the outcome of laparoscopic treatment of ovarian remnant syndrome (ORS) in dogs and cats. DESIGN Retrospective case series. ANIMALS 7 client-owned dogs and cats. PROCEDURES Medical records of dogs and cats with ORS that were treated laparoscopically at 3 large veterinary teaching hospitals were reviewed. Laparoscopic ovarian remnant resection was performed by means of either a 3-port or single-port technique with the patient in dorsal recumbency. The area caudal to both kidneys was thoroughly inspected for evidence of ovarian tissue by tilting the patient laterally. Any ovarian remnant tissue in these areas was resected with a bipolar vessel sealer. RESULTS 5 female dogs and 2 female cats that had previously undergone ovariectomy or ovariohysterectomy were included in the study. Six procedures were performed with a standard 3-port technique, and 1 was performed with a single-port technique. Median surgery time was 90 minutes (range, 50 to 150 minutes). No patient required conversion to laparotomy. Six of the 7 patients had complete resolution of clinical signs after surgery. One patient underwent laparotomy 7 weeks after surgery for management of stump pyometra, but no further ovarian tissue was detected. CONCLUSIONS AND CLINICAL RELEVANCE Laparoscopic management of ORS in this cohort of dogs and cats was associated with minimal morbidity. Laparoscopic treatment of ORS in dogs and cats may be recommended for appropriately selected patients.

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.