Gary W. Ellison

Embryonic Stem Cells Proliferate and Differentiate when Seeded into Kidney Scaffolds

The scarcity of transplant allografts for diseased organs has prompted efforts at tissue regeneration using seeded scaffolds, an approach hampered by the enormity of cell types and complex architectures. Our goal was to decellularize intact organs in a manner that retained the matrix signal for differentiating pluripotent cells. We decellularized intact rat kidneys in a manner that preserved the intricate architecture and seeded them with pluripotent murine embryonic stem cells antegrade through the artery or retrograde through the ureter. Primitive precursor cells populated and proliferated within the glomerular, vascular, and tubular structures. Cells lost their embryonic appearance and expressed immunohistochemical markers for differentiation. Cells not in contact with the basement membrane matrix became apoptotic, thereby forming lumens. These observations suggest that the extracellular matrix can direct regeneration of the kidney, and studies using seeded scaffolds may help define differentiation pathways.

Surgical treatment of septic peritonitis without abdominal drainage in 28 dogs.

The purpose of this study was to evaluate the surgical outcomes of 28 dogs with generalized septic peritonitis treated without postoperative abdominal drainage. The overall mortality rate was 46%, with most cases of peritonitis being caused by leakage of the gastrointestinal tract (75%). Etiology of peritonitis, abdominal cytopathology, total white blood cell count, packed cell volume, total protein, and results of serum biochemistries were not statistically different between survivors and nonsurvivors. The mortality rate of 46% is similar to other studies in which the abdomen was left open postoperatively for the management of septic peritonitis, although more advanced medical treatment than that used in earlier studies may have positively affected the outcome. The results of this study show that closure of the abdomen after the source of contamination has been successfully corrected, in combination with thorough intraoperative peritoneal lavage and appropriate postoperative medical management, may be an acceptable alternative method for the management of septic peritonitis.

Mouse stem cells seeded into decellularized rat kidney scaffolds endothelialize and remodel basement membranes.

Introduction To address transplant organ shortage, a promising strategy is to decellularize kidneys in a manner that the scaffold retains signals for seeded pluripotent precursor cells to differentiate and recapitulate native structures: matrix-to-cell signaling followed by cell-cell and cell-matrix interactions, thereby remodeling and replacing the original matrix. This would reduce scaffold antigenicity and enable xeno-allografts. Results DAPI-labeled cells in arterial vessels and glomeruli were positive for both endothelial lineage markers, BsLB4 and VEGFR2. Rat scaffold’s basement membrane demonstrated immunolabeling with anti-mouse laminin β1. Labeling intensified over time with 14 day incubations. Conclusion We provide new evidence for matrix-to-cell signaling in acellular whole organ scaffolds that induces differentiation of pluripotent precursor cells to endothelial lineage. Production of mouse basement membrane supports remodeling of host (rat)-derived scaffolds and thereby warrants further investigation as a promising approach for xenotransplantation. Methods We previously showed that murine embryonic stem cells arterially seeded into acellular rat whole kidney scaffolds multiply and demonstrate morphologic, immunohistochemical and gene expression evidence for differentiation. Vascular cell endothelialization was now further tested by endothelial specific BsLB4 lectin and anti-VEGFR2 (Flk1) antibodies. Remodeling of the matrix basement membranes from rat to mouse (“murinization”) was assessed by a monoclonal antibody specific for mouse laminin β1 chain.

A comparison of the Ameroid constrictor versus ligation in the surgical management of single extrahepatic portosystemic shunts

Twenty-two dogs were managed surgically for a single extrahepatic portosystemic shunt; 12 with surgical ligation and 10 with an Ameroid constrictor. Utilization of the Ameroid constrictor significantly decreased surgery time to approximately half that of the ligation technique. A decreased intraoperative and postoperative complication rate was noted with the Ameroid constrictor group. Follow-up evaluation demonstrated comparable efficacy when comparing surgical techniques. The Ameroid constrictor offered a surgical occlusion technique for management of a single extra-hepatic portosystemic shunt that was equally effective to ligation while shortening surgical time and minimizing the risks that are commonly associated with ligation of the shunting vessel.

Comparison of 5 surgical techniques for partial liver lobectomy in the dog for intraoperative blood loss and surgical time.

OBJECTIVE To compare surgical time and intraoperative blood loss for 5 partial liver lobectomy techniques in the dog. STUDY DESIGN Experimental in vivo study. ANIMALS Dogs (n=10). METHODS Five surgical techniques (SurgiTie(™) ; LigaSure(™) ; Ultracision(®) Harmonic Scalpel [UAS]; Suction+Clip; Suction+thoracoabdominal stapler [TA]) for partial liver lobectomy in dogs were evaluated and compared for total surgical time and intraoperative blood loss. Body weight, activated clotting time (ACT), heart rate, and intraoperative blood pressure (BP) were recorded. Blood loss was determined by adding the weight of the blood soaked sponges during surgery (1 g=1 mL) to the amount of suctioned blood (mL). Surgical time (in seconds) was determined from the start of the lobectomy until cessation of bleeding from the stump. Mean surgical time and mean blood loss for each technique were compared using a Tukeys multiple comparison test. RESULTS No significant differences were found between dogs for weight, ACT, heart rate, and intraoperative BP. No complications were seen with the SurgiTie(™) technique in 9 of 10 cases. There was no significant difference in surgical time between techniques however there was a significant difference for blood loss; the Suction+Clip method had significantly more blood loss than the other techniques. CONCLUSIONS Skeletonization of the lobar vessels before individually clipping them (Suction+Clip) resulted in a higher blood loss than using Suction+TA, UAS, SurgiTie(™) or the LigaSure(™) device. The SurgiTie(™) appears to be an acceptable method for partial liver lobectomy. CLINICAL RELEVANCE Although skeletonization and individually clipping the vessels had the highest blood loss, it still was <7.5% of total blood volume. All 5 techniques should be safe for clinical use in small to medium sized dogs up to 26 kg.

Single Incision Laparoscopic‐Assisted Intestinal Surgery (SILAIS) in 7 Dogs and 1 Cat

Objectives To describe the clinical findings and short-term outcome in 7 dogs and 1 cat undergoing single-incision laparoscopic-assisted intestinal surgery (SILAIS) using an SILS™ or EndoCone™ port. Study Design Prospective case series. Animals Dogs (n = 7) and cat (n = 1). Methods An SILS™ port using three 5-mm instrument cannulas or EndoCone™ port was used to perform an initial limited laparoscopic abdominal exploration. The stomach and descending duodenum were explored intracorporeally and the jejunum through orad descending colon was explored extracorporeally. All intestinal procedures (enterotomy, biopsy, resection, and anastomosis) were performed extracorporeally. Omentalization of affected bowel was accomplished either intracorporeally or extracorporeally. Short-term outcome was determined. Results SILAIS was completed successfully in all but 1 dog and all animals had a good short-term outcome. Most (n = 5) animals were discharged the day after surgery. SILAIS was performed in a median of 120 minutes (interquartile range; 82–148 minutes) and was associated with a moderate level of difficulty. No major complications occurred but conversion to celiotomy (n = 1) and enlargement of the incision (n = 3) was required because of inability to exteriorize the affected bowel. Conclusions SILAIS using an SILS™ or EndoCone™ port in dogs and cats is feasible and appears effective in selected cases. Single portal laparoscopic-assisted intestinal surgery might be an effective method of minimizing morbidity in dogs and cats with uncomplicated intestinal disease.OBJECTIVES To describe the clinical findings and short-term outcome in 7 dogs and 1 cat undergoing single-incision laparoscopic-assisted intestinal surgery (SILAIS) using an SILS™ or EndoCone™ port. STUDY DESIGN Prospective case series. ANIMALS Dogs (n = 7) and cat (n = 1). METHODS An SILS™ port using three 5-mm instrument cannulas or EndoCone™ port was used to perform an initial limited laparoscopic abdominal exploration. The stomach and descending duodenum were explored intracorporeally and the jejunum through orad descending colon was explored extracorporeally. All intestinal procedures (enterotomy, biopsy, resection, and anastomosis) were performed extracorporeally. Omentalization of affected bowel was accomplished either intracorporeally or extracorporeally. Short-term outcome was determined. RESULTS SILAIS was completed successfully in all but 1 dog and all animals had a good short-term outcome. Most (n = 5) animals were discharged the day after surgery. SILAIS was performed in a median of 120 minutes (interquartile range; 82-148 minutes) and was associated with a moderate level of difficulty. No major complications occurred but conversion to celiotomy (n = 1) and enlargement of the incision (n = 3) was required because of inability to exteriorize the affected bowel. CONCLUSIONS SILAIS using an SILS™ or EndoCone™ port in dogs and cats is feasible and appears effective in selected cases. Single portal laparoscopic-assisted intestinal surgery might be an effective method of minimizing morbidity in dogs and cats with uncomplicated intestinal disease.

Comparison of surgical variables in cats undergoing single‐incision laparoscopic ovariectomy using a LigaSure or extracorporeal suture versus open ovariectomy

OBJECTIVE To evaluate the applicability of single-incision laparoscopic ovariectomy (SILOVE) in cats using a single-incision laparoscopic port (SILP); to compare surgical time, complications, and postoperative pain after SILOVE using a LigaSure (SILOVE-LS) or extracorporeal suture (SILOVE-ECS), and open ovariectomy (open-OVE). STUDY DESIGN Randomized, blinded, prospective study. ANIMALS Healthy, domestic female cats (n = 24). METHODS Cats underwent physical examination, packed cell volume, total solids and blood urea nitrogen analysis. Cats were randomly assigned to 1 of 3 groups: SILOVE-LS (n = 8), SILOVE-ECS (8) or open-OVE (8). Surgical time, complications, and postoperative pain scores were recorded. RESULTS Single-incision laparoscopic ovariectomy was successful in (n = 8) SILOVE-LS cats and (n = 5) SILOVE-ECS cats. Surgical time was significantly longer for the SILOVE-ECS group compared with the SILOVE-LS (P < .0001) and open-OVE (P < .0001) groups, which were not different (P = .55). Complications were more frequent in the SILOVE-ECS group and removal of the SILP was required to complete ovariectomy in 3 cats. Cumulative 4-hour pain scores were not different between groups. CONCLUSIONS Single-incision laparoscopic ovariectomy using a SILP is a feasible method for OVE in cats. Single-incision laparoscopic ovariectomy using an extracorporeal suture is more time consuming and associated with more complications than either the SILOVE-LS or open-OVE methods.Objective To evaluate the applicability of single-incision laparoscopic ovariectomy (SILOVE) in cats using a single-incision laparoscopic port (SILP); to compare surgical time, complications, and postoperative pain after SILOVE using a LigaSure (SILOVE-LS) or extracorporeal suture (SILOVE-ECS), and open ovariectomy (open-OVE). Study Design Randomized, blinded, prospective study. Animals Healthy, domestic female cats (n = 24). Methods Cats underwent physical examination, packed cell volume, total solids and blood urea nitrogen analysis. Cats were randomly assigned to 1 of 3 groups: SILOVE-LS (n = 8), SILOVE-ECS (8) or open-OVE (8). Surgical time, complications, and postoperative pain scores were recorded. Results Single-incision laparoscopic ovariectomy was successful in (n = 8) SILOVE-LS cats and (n = 5) SILOVE-ECS cats. Surgical time was significantly longer for the SILOVE-ECS group compared with the SILOVE-LS (P < .0001) and open-OVE (P < .0001) groups, which were not different (P = .55). Complications were more frequent in the SILOVE-ECS group and removal of the SILP was required to complete ovariectomy in 3 cats. Cumulative 4-hour pain scores were not different between groups. Conclusions Single-incision laparoscopic ovariectomy using a SILP is a feasible method for OVE in cats. Single-incision laparoscopic ovariectomy using an extracorporeal suture is more time consuming and associated with more complications than either the SILOVE-LS or open-OVE methods.

Evaluation of costs and time required for laparoscopic-assisted versus open cystotomy for urinary cystolith removal in dogs: 43 cases (2009-2012)

OBJECTIVE To compare required time and costs of surgery and hospitalization as well as prevalence of incomplete urinary cystolith removal associated with laparoscopic-assisted cystotomy versus open cystotomy in dogs. DESIGN Retrospective case series. ANIMALS 20 dogs with urolithiasis treated by laparoscopic-assisted cystotomy and 23 dogs treated by open cystotomy. PROCEDURES Medical records were reviewed. Surgery cost, hospitalization cost, total cost, surgery time, days in hospital, incomplete cystolith removal, and number of doses of analgesic administered IV after surgery were compared between the laparoscopic-assisted cystotomy and open cystotomy groups. Results-Surgery cost and total cost were significantly higher in the laparoscopic-assisted cystotomy group. Hospitalization cost, days in hospital, and prevalence of incomplete cystolith removal did not differ significantly between groups. Number of doses of analgesic was significantly lower in the laparoscopic-assisted cystotomy group. CONCLUSIONS AND CLINICAL RELEVANCE Laparoscopic-assisted cystotomy was more time-consuming and expensive but associated with fewer postoperative doses of injectable analgesics, compared with open cystotomy. Laparoscopic-assisted cystotomy is an acceptable, more expensive, and minimally invasive alternative to open cystotomy for the removal of urinary cystoliths in dogs.

Gastric Dilatation Volvulus: Surgical Prevention

Definitive surgical management of gastric dilatation volvulus involves gastric repositioning, gastric resection when indicated and surgical formation of a permanent adhesion to prevent recurrence of the problem. Derotation and gastropexy procedures are recommended as soon as the patient is a reasonable anesthetic risk. Splenectomy and pyloric outlet procedures are of questionable value in preventing recurrence in the majority of cases. In North America, most veterinary surgeons perform right-sided antral gastropexy as a means of preventing recurrence. The technical advantages and disadvantages and experimental and clinical results of several techniques, including the tube gastrostomy, incisional gastropexy, circumcostal gastropexy, and belt-loop gastropexy, are discussed.

Comparison of computed tomographic angiography and ultrasonography for the detection and characterization of portosystemic shunts in dogs.

The purpose of this retrospective study was to compare the accuracy of computed tomographic angiography (CTA) and abdominal ultrasonography in detecting and characterizing portosystemic shunts (PSS) in dogs. Medical records of 76 dogs that underwent CTA and/or abdominal ultrasonography suspected to have PSS were reviewed. Presence or absence, and characterization of PSS (when present) on CTA were reviewed by a board-certified veterinary radiologist that was blinded to the clinical findings. The abdominal ultrasonography findings were reviewed from the medical records. Visualization and description of the origin and insertion of PSS on CTA and abdominal ultrasonography were related with laboratory, surgical, or mesenteric portographic confirmation of the presence or absence of PSS. The sensitivity for detection of PSS with CTA (96%) was significantly higher than abdominal ultrasonography (68%; P < 0.001). The specificities for CTA and abdominal ultrasonography were 89% and 84%, respectively (P = 0.727). Computed tomographic angiography detected the correct origin in 15 of 16 dogs and correct insertion in 15 of 16 dogs with congenital PSS. Abdominal ultrasonography detected the correct origin in 24 of 30 dogs and correct insertion in 20 of 33 dogs with congenital PSS. Multiple acquired PSS were seen in four of five dogs and in one of six dogs on CTA and abdominal ultrasonography, respectively. Computed tomographic angiography was 5.5 times more likely to correctly ascertain the presence or absence of PSS when compared to abdominal ultrasonography (P = 0.02). Findings indicated that CTA is a noninvasive diagnostic modality that is superior to abdominal ultrasonography for the detection and characterization of PSS in dogs.