Kelli N. Mayhew

Thoracoscopic Subphrenic Pericardectomy Using Double-Lumen Endobronchial Intubation for Alternating One-Lung Ventilation

OBJECTIVE To report the technique, complications, and effectiveness of thoracoscopic subphrenic pericardectomy (SPP) using double-lumen endobronchial intubation for alternating 1-lung (OLV) in healthy dogs. STUDY DESIGN Prospective cohort study. ANIMALS Mature purpose-bred dogs (n=7). METHODS Bronchoscope-assisted placement of a left-sided double-lumen endobronchial tube, immediately before surgery, allowed intraoperative alternation of ventilation between lung fields. A camera portal was established in a subxyphoid location. Two instrument portals were established at the 4th-6th intercostal spaces on the right and left sides. A vessel-sealing device was used to create the subphrenic pericardectomy. After termination of the procedure, dogs were humanely euthanatized under anesthesia and necropsy performed. In each dog, the extent of pericardectomy and any complications were evaluated. RESULTS Technical difficulties with tube placement occurred in 4 dogs, but alternating OLV was achieved in all dogs and SPP completed successfully. Median surgical time was 87.5 minutes (range, 80-105 minutes). At necropsy, 0.5-2 cm of pericardial tissue remained ventral to the intact phrenic nerve in 6 dogs; in 1 dog, the phrenic nerve was transected on the left side only. CONCLUSIONS Thoracoscopic subphrenic pericardectomy is a technically feasible procedure in healthy dogs. Double-lumen endobronchial intubation allowed alternating OLV without intraoperative bronchoscopically guided tube manipulation in all but 1 dog. CLINICAL RELEVANCE Thoracoscopic subphrenic pericardectomy could potentially be used for management of conditions where relief of pericardial constriction or access to intrapericardial structures is desired.

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.

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.

Single-port laparoscopic cryptorchidectomy in dogs and cats: 25 cases (2009-2014)

OBJECTIVE To describe the operative technique for single-port laparoscopic cryptorchidectomy (SPLC) in dogs and cats and evaluate clinical outcome for patients that underwent the procedure. DESIGN Retrospective case series. ANIMALS 25 client-owned dogs (n = 22) and cats (3). PROCEDURES Dogs and cats that underwent SPLC with 3 commercially available single-port devices between 2009 and 2014 were retrospectively identified through a multi-institutional medical records review. Surgery was performed via a single-port device placed through a 1.5- to 3.0-cm abdominal incision either at the region of the umbilicus or caudal to the right 13th rib. The cryptorchidectomy was performed with graspers, a bipolar vessel sealing device, and a 30° telescope. RESULTS SPLC was performed with a single-incision laparoscopic surgery port (n = 15), a multitrocar wound-retractor access system (8), or a metal resterilizable single-port access device (2). Median age was 365 days (range, 166 to 3,285 days). Median body weight was 18.9 kg (41.6 lb; range, 1.3 to 70 kg [2.9 to 154 lb]). Median surgical time was 38 minutes (range, 15 to 70 minutes). Thirty-two testes were removed (12 left, 6 right, and 7 bilateral). Four patients had 1 additional abdominal surgical procedure performed concurrently during SPLC. No intraoperative or postoperative complications were encountered. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that SPLC can be performed in a wide range of dogs and cats with cryptorchidism and can be combined with other elective laparoscopic surgical procedures. The SPLC technique was associated with a low morbidity rate and provided a potentially less invasive alternative to traditional open and multiport laparoscopic techniques.

Laparoscopic splenectomy: operative technique and outcome in three cats.

Clinical summary: The clinical findings, treatment and outcome for three cats that underwent laparoscopic splenectomy using bipolar vessel-sealing devices for resection of diffuse splenic disease are described. In each case, a three-portal laparoscopic technique was used. The spleen was manipulated and its mesentery and associated vessels sequentially cauterized and ligated to enable removal through a portal incision with minimal hemorrhage. Each of the three patients recovered from anesthesia without incident and was able to be discharged to the owner the next day. Practical significance: Laparoscopic splenectomy may be a safe and effective alternative to celiotomy in a select group of cats requiring splenectomy.

Short-Term Outcome of Multiple Port Laparoscopic Splenectomy in 10 Dogs

OBJECTIVE To describe surgical techniques for multiple port laparoscopic splenectomy (MLS) in dogs and report short-term outcome. STUDY DESIGN Retrospective case series. ANIMALS Dogs (n = 10) with naturally occurring splenic disease. METHODS Medical records (March 2012-March 2013) of dogs that had MLS were reviewed. Data retrieved included signalment, weight, clinical signs, physical examination findings, preoperative laboratory and ultrasonographic findings, port number, size, and location, patient positioning, additional procedures performed, surgical duration, histopathologic diagnosis, duration of hospitalization, and perioperative complications. RESULTS Ten dogs (median weight, 28.7 kg; range, 20.2-46.0 kg) had MLS using a 3 or 4 port technique and a vessel-sealing device for tissue dissection along the splenic hilus. Dog positioning varied because of additional laparoscopic or laparoscopic-assisted procedures including adrenalectomy (n = 2), ovariectomy (1), gastropexy (1), and intestinal resection and anastomosis (1). Conversion to an open approach was necessary in 1 dog because of inadequate visibility caused by omental adhesions. One dog had hemorrhage from an omental vessel, but open conversion was not required. CONCLUSIONS MLS was associated with little perioperative morbidity and few complications in this cohort of dogs and may be a reasonable option for surgical management of dogs requiring elective splenectomy.

Complications after corrective surgery for lateral patellar luxation in dogs: 36 cases (2000-2011).

OBJECTIVE To determine the frequency and severity of complications after corrective surgery in dogs with lateral patellar luxation (LPL) and identify risk factors for reluxation. DESIGN Retrospective case series. ANIMALS 36 client-owned dogs with 47 affected stifle joints. PROCEDURES Medical records of dogs that underwent surgical correction of LPL at 1 of 2 veterinary teaching hospitals between 2000 and 2011 were reviewed. Data analyzed included signalment, grade of luxation, orthopedic comorbidities, surgical procedures performed, frequency and type of complications, and whether a second surgery was performed. RESULTS A total of 36 dogs with 47 affected stifle joints met the inclusion criteria. Complications were recorded for 24 of 47 (51.1%) stifle joints; there were major complications for 18 of 47 (38.3%) stifle joints. All complications were confirmed through examination by a veterinarian. The most frequent complication was reluxation, which was detected in 10 of 47 (21.3%) stifle joints. Dogs that underwent bilateral surgical repair during a single anesthetic episode had odds of reluxation that were 12.5 times the odds of reluxation for dogs that underwent unilateral surgical repair. CONCLUSIONS AND CLINICAL RELEVANCE Complication rate after corrective surgery for LPL was high, with reluxation being the most common complication in this population of dogs. Performing staged bilateral surgeries may decrease the risk of reluxation.