Marije Risselada

Assessment of fracture healing after minimally invasive plate osteosynthesis or open reduction and internal fixation of coexisting radius and ulna fractures in dogs via ultrasonography and radiography

OBJECTIVE To evaluate fracture healing after minimally invasive plate osteosynthesis (MIPO) or open reduction and internal fixation (ORIF) of coexisting radius and ulna fractures in dogs via ultrasonography and radiography. DESIGN Prospective cohort study. ANIMALS 16 dogs with radius-ulna fractures that underwent MIPO (n = 9; 2 dogs were subsequently not included in the analyses because of incomplete follow-up information) or ORIF (7). PROCEDURES Dogs in the 2 treatment groups were matched by age, body weight, and configuration of the fractures. Fracture healing was evaluated with ultrasonography, power Doppler ultrasonography, and radiography every 3 to 4 weeks until healing was complete; a semiquantitative score based on the number of Doppler signals was used to characterize neovascularization, and subjective B-mode ultrasonographic and radiographic scores were assigned to classify healing. RESULTS Fractures in dogs that underwent MIPO healed in significantly less time than did fractures in dogs that underwent ORIF (mean ± SD; 30 ± 10.5 days and 64 ± 10.1 days, respectively). Radiography revealed that fractures in dogs that underwent MIPO healed with significantly more callus formation than did fractures in dogs that underwent ORIF. Although Doppler ultrasonography revealed abundant vascularization in fractures that were healing following MIPO, no significant difference in neovascularization scores was found between groups. CONCLUSIONS AND CLINICAL RELEVANCE For dogs with radius-ulna fractures, data indicated that bridging osteosynthesis combined with a minimally invasive approach contributed to rapid healing after MIPO. The MIPO technique may offer some clinical advantage over ORIF, given that complete radius-ulna fracture healing was achieved in a shorter time with MIPO.

Penetrating injuries in dogs and cats. A study of 16 cases.

The objective of this retrospective study was to assess radiographical and surgical findings, surgical management and outcome of penetrating injuries in dogs and cats by evaluating patient records. Sixteen patients were identified (15 dogs and one cat), four with gunshot wounds, and 12 with fight wounds (11 with bite wounds, one struck by a claw). The thoracic cavity was affected in six patients, the abdominal cavity in three cases. Both cavities were affected in five dogs and the trachea in two cases. All of the patients with fight wounds were small breed dogs. Multiple injuries to internal organs that required intervention were found surgically after gunshot wounds and a high amount of soft tissue trauma requiring reconstruction was present after fight wounds. Radiography diagnosed body wall disruption in two cases. All of the affected thoracic body walls in the fight group had intercostal muscle disruptions which was diagnosed surgically. Fourteen patients survived until discharge and had a good outcome. In conclusion, penetrating injuries should be explored as they are usually accompanied by severe damage to either the internal organs or to the body wall. A high level of awareness is required to properly determine the degree of trauma of intercostal muscle disruption in thoracic fight wounds.

Surgically planned versus histologically measured lateral tumor margins for resection of cutaneous and subcutaneous mast cell tumors in dogs: 46 cases (2010-2013).

OBJECTIVE To compare preplanned lateral surgical margins and measured lateral histologic margins for cutaneous and subcutaneous mast cell tumor (MCT) resections in dogs. DESIGN Retrospective case series. SAMPLE 51 biopsy specimens from dogs (n = 46) with MCTs. PROCEDURES All canine patients that underwent curative-intent surgical resection of cutaneous or subcutaneous MCTs from January 1, 2010, through June 30, 2013, with complete medical records including signalment, body condition score (BCS), surgery report (with measured surgical margins), and histopathology report were included. The surgically measured tumor margins in each quadrant were grouped and compared with the corresponding histologic margins. Specimens from dogs with truncal MCTs and a BCS of 7 to 9 on a scale from 1 to 9 (ie, high) were compared with those of dogs with a BCS of 4 to 6 to evaluate effect of BCS on tissue margins. RESULTS 51 specimens were included. Surgically mapped lateral margins differed significantly from histologically reported margins in all 4 quadrants. The mean histologic margins were 35% to 42% smaller than the surgical margins for the combined 51 specimens. A higher BCS did not significantly influence the magnitude of the decrease in lateral margins measured histologically. No significant difference was found for the magnitude of the differences between any of the 4 lateral margins. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study suggested that surgical and histologic margins may differ significantly for canine cutaneous and subcutaneous MCTs. This may be a result of tissue shrinkage following excision and fixation, extension of the MCT beyond palpable margins, or both. Histologic measurements may significantly underestimate the tumor-free margins in dogs with cutaneous and subcutaneous MCTs.

Multiple Congenital PSS in a Dog: Case Report and Literature Review

A 4 yr old spayed female mixed-breed dog presented with a 2 yr history of recurring increases in liver enzymes. Two congenital portosystemic shunts (PSSs) were identified using computed tomography (CT) angiography, which included a portoazygous and portorenal extrahepatic shunt. Double right renal veins were also identified. The shunts were successfully identified and attenuated with cellophane banding. Multiple congenital PSS is a rare phenomenon, but should be considered during exploratory laparotomy for PSS and in dogs with poor response to surgical attenuation of a single PSS. CT proved to be a crucial part of accurate diagnosis and surgical planning for this dog with multiple congenital PSS.

Postmortem evaluation of surgery site leakage by use of in situ isolated pulsatile perfusion after partial liver lobectomy in dogs.

OBJECTIVE To evaluate postmortem surgery site leakage by use of in situ isolated pulsatile perfusion after partial liver lobectomies. ANIMALS 10 healthy mixed-breed male dogs. PROCEDURES Dogs were anesthetized, and 5 surgical techniques (pretied suture loop, energy-based sealer-divider, harmonic scalpel, suction with clip application, or suction with use of a thoracoabdominal stapler) were used to perform 5 partial liver lobectomies in each dog. Dogs were euthanatized, and the portal vein and hepatic artery were cannulated and perfused with a modified kidney perfusion machine (pulsatile flow for arterial perfusion and nonpulsatile flow for portal perfusion). Lobectomy sites were inspected for leakage of perfusate, and time until detection of leakage was recorded. The techniques in each dog were ranked on the basis of time until leakage. Time until leakage and rankings for each surgical technique were analyzed by use of an ANOVA. RESULTS Leakage of perfusate was recorded in 44 lobes at supraphysiologic pressures. Of the 6 lobes without leakage, a pretied suture loop procedure was performed in 5 and a harmonic scalpel procedure was performed in 1. Time until leakage and the ranking differed significantly between the pretied suture loop and the other techniques. Time until leakage and ranking did not differ significantly among the other techniques. CONCLUSIONS AND CLINICAL RELEVANCE Time until leakage of perfusate was greater for the pretied suture loop technique than for the other techniques, and that technique did not fail in 5 of 10 lobes. However, all techniques appeared to be safe for clinical use.

Correlation of histology of healed fractures and tissue surrounding implants with ultrasonographic and radiographic appearance

OBJECTIVES To determine if there was histological correlation with ultrasonographic images of healed fractures and implant-associated tissue after fracture treatment by plate osteotomy. METHODS Eight adult dogs were included in this retrospective study. Ultrasonography (B-mode and power Doppler) and radiography were performed before plate removal. Surgical biopsies were taken of the fracture site and the tissue adjacent to the plate. These were stained with haematoxylin and eosin to assess histomorphology and bone content and immunolabelled with CD31 to assess vascularity. RESULTS Ultrasound and radiographic diagnoses of a healed fracture correlated with histological finding of bone healing. Ultrasonography and histology findings of vascularity were also highly correlated. The tissue surrounding the surgical implants was significantly more vascularised on both ultrasonography and histology than that at the fracture site itself. CLINICAL RELEVANCE Ultrasonography can be used to diagnose fracture healing in plated fractures. Power Doppler ultrasonography examination of fracture healing should be performed away from surgical implants to avoid false-positive results of vascularisation.

Evaluation of various gastrojejunostomy tube constructs for enteral support of small animal patients

OBJECTIVE To evaluate the feasibility of manufacturing gastrojejunostomy tubes from jejunostomy and gastrostomy tubes that would allow for gastric and enteral feeding of and aspiration of gastric contents from small animal patients. DESIGN In vitro study. SAMPLE 9 gastrojejunostomy constructs. PROCEDURES Commercially available gastrostomy and jejunostomy tubes were combined to create 9 constructs. Three investigators tested each construct with 4 solutions (tap water, a commercial enteral diet, and 2 canned food-water mixtures) and 3 syringe sizes for ease of injection through the gastrostomy and jejunostomy tubes and aspiration through the gastrostomy tube. Flow rates were calculated and analyzed to evaluate effects of tube diameter and syringe size for each solution. RESULTS The 20F/8F, 24F/8F, 28F/8F, and 28F/10F (gastrostomy tube/jejunostomy tube) constructs allowed for injection and aspiration of all solutions. The 5F jejunostomy tubes allowed only water to be injected, whereas the 8F jejunostomy tubes did not allow injection of the canned food-water mixtures. The 20F/10F construct did not allow injection or aspiration through the gastrostomy tube, whereas the 18F/8F construct allowed injection but not aspiration through the gastrostomy tube. Faster flow rates through the gastrostomy tube were associated with larger gastrostomy tube diameter, smaller jejunostomy tube diameter, and smaller syringe size. Faster flow rates through the jejunostomy tube were associated with smaller jejunostomy tube diameter. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that homemade gastrojejunostomy constructs would allow for administration of a variety of enteral diets. Limitations to the administration and aspiration of various enteral diets as well as patient needs should be considered before a gastrojejunostomy tube combination is chosen.

In vitro evaluation of bursting pressure and intestinal luminal area of three jejunostomy tube placement techniques in dogs

OBJECTIVE To compare pursestring, Witzel (seromuscular inversion), and seromuscular incision jejunostomy tube placement techniques in vitro. SAMPLE Jejunal specimens from 10 dogs. PROCEDURES Jejunal segments (50 cm) were harvested immediately prior to euthanasia from 10 mixed-breed dogs Specimens were harvested with the orad and aborad ends clamped and stored in saline (0.9% NaCl) solution-soaked towels during instrumentation. Three jejunostomy tubes were placed via 3 techniques (pursestring, Witzel, and seromuscular incision), and 2 double lumen central venous catheters were placed at each intestinal end for luminal filling and leak testing. Intestinal luminal area was measured ultrasonographically with specimens suspended in a warm undyed saline solution bath with the intestinal lumen filled with dyed saline solution (intraluminal pressure, 6 mm Hg). Leak testing was performed by means of infusion of dyed saline solution (4 mL/min) until each jejunostomy site failed. Intestinal luminal area and leakage pressure were compared between the 3 tube placement techniques. RESULTS The Witzel and seromuscular incision techniques decreased the intestinal luminal area measured at the tube insertion site, albeit nonsignificantly. For the seromuscular incision technique, a significant decrease in intestinal luminal area at the intraluminal site of measurement was found. For 2/30 specimens (1/10 pursestring and 1/10 seromuscular incision), failure occurred at pressures within the range of previously reported peak peristaltic pressure for dogs. Failure occurred at supraphysiologic peristaltic pressures for the remaining 28 specimens, including all 10 specimens for the Witzel technique. CONCLUSIONS AND CLINICAL RELEVANCE In this in vitro study, all specimens for the Witzel technique withstood physiologic peristaltic pressures during leak testing. Both tunneling techniques (Witzel and seromuscular incision) created a decrease in intestinal luminal area. Further investigation, including in vivo testing, is indicated to evaluate the clinical relevance of these findings.

Evaluation of nonunion fractures in dogs by use of B-mode ultrasonography, power Doppler ultrasonography, radiography, and histologic examination

OBJECTIVE To investigate the use of ultrasonography to assess nonunion of fractures in dogs and to compare results of ultrasonography, radiography, and histologic examination. SAMPLE POPULATION 8 nonunion fractures in 6 dogs (1 each in 5 dogs and 3 in 1 dog); dogs ranged from 7 to 94 months of age and weighed 6 to 30 kg. PROCEDURES Diagnostic assessment consisted of complete clinical and orthopedic examinations, radiography, B-mode (brightness mode) ultrasonography, and power Doppler ultrasonography. Biopsy samples were obtained during surgery for histologic examination. They were stained with H&E and immunolabeled by use of anti-CD31 antibodies. Correlations of power Doppler score, power Doppler count, vessel area, and radiographic prediction with the mean number of vessels counted per hpf were derived. RESULTS Radiographically, 7 of 8 nonunion fractures were diagnosed as atrophic and were therefore estimated to be nonviable. Vascularity of nonunion fractures during power Doppler ultrasonography ranged from nonvascularized to highly vascularized. Absolute vessel count during histologic examination ranged from 0 to 63 vessels/hpf; 5 nonunion sites had a mean count of > 10 vessels/hpf. Vascularity during power Doppler ultrasonography was highly correlated with the number of vessels per hpf, whereas the correlation between the radiographic assessment and histologic evaluation was low. CONCLUSIONS AND CLINICAL RELEVANCE Radiographic prediction of the viability of nonunion fractures underestimated the histologically assessed vascularity of the tissue. Power Doppler ultrasonography provided a more accurate estimation of the viability of the tissue and therefore the necessity for debridement and autografts during revision surgery.