Patent ductus arteriosus: anatomy and surgery in a cat

A 5-month-old cat with patent ductus arteriosus (PDA) and probable small ventricular septal defect had severe cardiomegaly and congestive heart failure. The cat improved slightly with medical therapy and markedly after surgical closure of the ductus. A 4th left intercostal space thoracotomy gave good exposure. The external anatomy of the PDA was similar to that of a short, wide PDA in dogs; however, the internal aortic orifice was situated more cranial than in dogs, as evidenced by preoperative cardiac catheterization. Examination 1 year later showed marked reductions in heart size and electrocardiographic amplitude. The cat was 1 of 3 with clinically diagnosed PDA at the University of Pennsylvania from 1968 to 1980. The prevalence of PDA in 14,224 cats (0.2/1,000) was significantly less than in 68,049 dogs (4.7/1,000).     

Patent ductus arteriosus repair in general practice

A 3-month-old female German Shepherd puppy was presented for routine vaccination. Clinical evaluation revealed a grade 5/6 continuous murmur with the point of maximal intensity over the left 4th intercostal space. Echocardiography revealed a patent ductus arteriosus (PDA). The PDA was closed by a team of general practitioners using the Jackson-Henderson technique, via a standard 4th intercostal thoracotomy. A multi-modal approach to analgesia and premedication was employed. A successful outcome was achieved with no murmur or evidence of cardiac disease present 6 months after surgical occlusion. The literature is reviewed with an emphasis placed on choosing techniques that are appropriate to the level of expertise of the surgical and anaesthetic teams, as well as the surgical facilities available.     

Real-time 3D transesophageal echocardiography-guided closure of a complicated patent ductus arteriosus in a dog

Advanced imaging modalities are becoming more widely available in veterinary cardiology, including the use of transesophageal echocardiography (TEE) during occlusion of patent ductus arteriosus (PDA) in dogs. The dog in this report had a complex history of attempted ligation and a large PDA that initially precluded device placement thereby limiting the options for PDA closure. Following a second thoracotomy and partial ligation, the morphology of the PDA was altered and device occlusion was an option. Angiographic assessment of the PDA was limited by the presence of hemoclips, and the direction of ductal flow related to the change in anatomy following ligature placement. Intra-operative TEE, in particular real-time three-dimensional imaging, was pivotal for assessing the PDA morphology, monitoring during the procedure, selecting the device size, and confirming device placement. The TEE images increased operator confidence that the size and location of the device were appropriate before release despite the unusual position. This report highlights the benefit of intra-operative TEE, in particular real-time three-dimensional imaging, for successful PDA occlusion in a complicated case.     

Intrathoracic tracheal avulsion in three cats

The surgical repair of complete intrathoracic tracheal avulsion in three cats is described. The initial presenting signs included dyspnoea, exercise intolerance and exertional cyanosis. Diagnosis was based upon the clinical signs, survey radiography and tracheal endoscopy. The ruptures were repaired via a right lateral thoracotomy made at the third or fourth intercostal interspace. Abnormal trachea was resected and a standard tracheal anastomosis was performed. Surgical results were considered excellent in all cases.     

Indications, outcomes and complications following lateral thoracotomy in dogs and cats

OBJECTIVES: Lateral thoracotomy is widely used for surgical management of thoracic diseases in small animals. The purpose of this paper is to describe the indications for lateral thoracotomy in dogs and cats and the associated outcomes and complications. METHODS: Medical records of animals undergoing lateral thoracotomy were reviewed and owners contacted regarding complications and survival. Relationships between signalment and treatment variables and outcome variables were investigated. RESULTS: Seventy dogs and 13 cats underwent lateral thoracotomy. Sixty-two per cent of cats and 91 per cent of dogs survived to discharge. Survival to discharge was significantly lower in cats than dogs, for neoplastic than non-neoplastic disease and in older animals. Survival to discharge was higher in animals undergoing patent ductus arteriosus ligation than in those undergoing lung lobectomy or oesophageal surgery. Survival to discharge was not related to surgeon experience. The incidence of complications was not related to species, age, disease, duration of surgery, surgeon experience or duration of thoracostomy tube placement. A low complication rate (5 per cent) was associated with thoracostomy tubes. CLINICAL SIGNIFICANCE: The approach of lateral thoracotomy has a minimal complication rate and animals with a disease requiring this approach have a high survival rate.     

Intercostal thoracotomy closure: transcostal sutures as a less painful alternative to circumcostal suture placement

OBJECTIVE: To determine if transcostal thoracotomy closure resulted in less pain than circumcostal closure. STUDY DESIGN: Experimental cadaver and prospective clinical study. ANIMALS: Two canine cadavers and 13 adult, 22-29 kg dogs. METHODS: Phase 1: In 2 cadavers, 4 suture passage techniques were evaluated to determine the incidence of nerve entrapment in circumcostal intercostal thoracotomy closure. Phase 2: Pain after circumcostal closure (7 dogs) or transcostal closure (6 dogs) of a 4th intercostal space thoracotomy was evaluated by use of pain threshold scores, fentanyl administration rates, heart and respiratory rates, and numerical ratings for behavior. Arterial blood gas analyses were obtained 4 hours postoperatively. Transcostal closure was accomplished by drilling 5-6 small holes in the 5th rib and passing sutures through the holes and around the 4th rib to achieve closure. Pain threshold scores (PTS) were measured by an observer unaware of closure assignment, at 2, 4, 12, and 24 hours after closure by applying slowly increasing pressure to the incision line using a load cell. Rates of fentanyl administration were adjusted based on subjective impressions of dog comfort by a second observer unaware of closure assignment. RESULTS: A 70-100% incidence of nerve entrapment was found for all circumcostal techniques. PTS was higher (P=.045) and fentanyl infusion rates were lower (P=.001) for the transcostal group at 2, 4, 12, and 24 hour postoperatively compared with the circumcostal group. CONCLUSION: There is a high incidence of nerve entrapment using circumcostal closure techniques. A transcostal technique appears to be associated with less pain during the first 24 hours postoperatively. CLINICAL RELEVANCE: Based on lower pain scores, transcostal thoracotomy closure may be preferable to circumcostal closure techniques.     

Minimally invasive patent ductus arteriosus occlusion in 5 dogs

OBJECTIVE: To report a technique for minimally invasive occlusion of patent ductus arteriosus (PDA) and outcome in 5 dogs. STUDY DESIGN: Clinical cases. Animals: Five, 4-6-month-old, dogs with PDA. MATERIALS AND METHODS: Titanium ligating clips were used for PDA closure in all dogs. Three dogs had video-enhanced mini-thoracotomy PDA occlusion. Two other dogs had thoracoscopic PDA occlusion using a custom-designed thoracoscopy clip applicator. RESULTS: Thoracoscopic PDA occlusion was successful in both dogs in which it was attempted. Complete PDA closure was achieved in 4 dogs. Three months after surgery, the largest dog had residual ductal flow that hemodynamically was insignificant. CONCLUSIONS: Although technically demanding, minimally invasive PDA occlusion is a safe and reliable technique in dogs. Preoperative measurement of the diameter of the PDA is crucial to determine if complete closure with metal clips can be achieved. CLINICAL RELEVANCE: Minimally invasive PDA occlusion should be considered as an alternative to occlusion via conventional thoracotomy.     

Modified rib pivot lateral thoracotomy: a case series

Objective

To describe a modified rib pivot thoracotomy and its clinical application in client‐owned dogs and cats.

Study design

Case series of 24 dogs and 1 cat requiring a thoracotomy.

Methods

A lateral thoracic incision over the required thoracic segment was made. The latissimus dorsi muscle was reflected dorsally. The predetermined rib was identified and the periosteum overlying the rib was elevated circumferentially, avoiding the intercostal neurovascular structures. Holes were pre‐placed above and below the proposed osteotomy site. The rib was osteotomised and pivoted cranially. The pleura was incised and the required intrathoracic procedure was then performed. The thoracic cavity was closed by pre‐placement of a suture through the pre‐placed holes within the osteotomised rib. The pleura and intercostal musculature were closed, avoiding the intercostal neurovascular structures. The rib was re‐apposed and the lateral approach was closed. The cases included were reviewed for both the rib pivoted as per the procedure required and postoperative complications.

Results

The study group comprised 8 Staffordshire Bull Terriers, 2 Poodles, 2 German Shepherd Dogs, 1 each of Basset Hound, Rhodesian Ridgeback, Golden Retriever, Australian Shepherd, Vizsla, Bull Mastiff, Schnauzer, Jack Russell Terrier, Bulldog, Deerhound, Labrador Retriever and Australian Terrier, and 1 cat. A modified rib pivot thoracotomy was performed for lung lobectomy (n = 11), oesophagectomy (7), subtotal pericardectomy (5), patent ductus arteriosus ligation (1) and thoracic duct ligation (1). Follow‐up ranged from 2 to 40 weeks postoperatively. Postoperative complications included seroma formation in two dogs.

Conclusion

A modified rib pivot thoracotomy should be considered as an alternative lateral thoracic approach with good exposure, minimal complications and low morbidity.     

Dog bite wounds in dogs and cats: a retrospective study of 196 cases

The age, type, etc., time of injury, body areas injured, treatment modalities and mortality rates were reviewed in 185 dogs and 11 cats that were bitten by dogs. Male dogs were more frequently bitten than females, and small dogs (< or = 10 kg) were not only the most common victims but also were more likely to suffer multiple injuries. Mortality occurred only in cases with thoracic or abdominal injuries. Exploratory thoracotomy, performed in some of the cases presented with penetrating thoracic injury, did not prove to alter prognosis. Cats are not as frequently bitten as dogs, and are often younger than the mean age of cats in the overall hospital population.     

Pericardial free patch grafting as a rescue technique in surgical management of right atrial HSA

A 7 yr old, neutered female vizsla underwent an exploratory thoracotomy after diagnosis of recurrent hemorrhagic pericardial effusion and a right auricular mass. Staging tests were negative for metastasis. The patient underwent a right, fourth intercostal thoracotomy, subtotal pericardectomy, right auricular mass excision, and pericardial free patch graft. The patient experienced blood loss during surgery, which required a packed red blood cell transfusion. The patient experienced transient arrhythmias postoperatively, but was discharged from the hospital 48 hr later. Histopathologic diagnosis of the mass was hemangiosarcoma. The patient was treated with carboplatin single-agent chemotherapy and palliative radiation therapy. The patient died at home, presumably from metastatic disease 260 days postoperatively. Surgical mass removal or debulking along with pericardial free patch grafting may be considered as palliative treatment options for dogs diagnosed with right auricular masses. In this case report, other techniques failed to repair the defect in the heart and a free patch graft offered a good rescue procedure with a favorable outcome without the need for inflow and outflow occlusion when used in conjunction with adjunctive therapies.     

Successful surgical treatment of mitral valve stenosis in a dog

OBJECTIVE: To report the successful surgical management (open mitral commissurotomy, OMC) of mitral stenosis (MS), incorporating heart-beating cardiopulmonary bypass (CPB), in a 1-year-old dog. STUDY DESIGN: Clinical case. ANIMALS: One-year-old Cairn Terrier with MS. MATERIALS AND METHODS: Diagnosis of MS was confirmed by means of 2-dimensional, continuous-wave and color-flow Doppler echocardiography. Surgery was performed through a left intercostal thoracotomy. CPB was initiated and the heart was kept beating. The fused commissures of the mitral valve were incised to free the cusps of the valve. RESULTS: Left intercostal thoracotomy allowed easy observation of the mitral orifice during heart-beating OMC. Persistent bleeding from the atriotomy site required a second surgical procedure after which the dog had an uneventful recovery. Echocardiography at 2 weeks and 1 year postoperatively indicated substantial improvement in left ventricular filling (pressure half-time=187 ms before surgery, 105 ms [2 weeks] and 110 ms [1 year] after surgery). Enlargement of the left atrium resolved; however, moderate mitral valve regurgitation was still present. CONCLUSIONS: MS can be successfully treated by OMC, facilitated by use of CPB. Substantial improvement in cardiac function was evident by ultrasound and Doppler examination postoperatively. CLINICAL RELEVANCE: OMC under heart-beating CPB should be considered for the treatment of MS in the dog.     

Intercostal thoracotomy in 20 dogs: muscle-sparing versus traditional techniques

The levels of pain, duration of approaching and closure, and surgical exposure associated with intercostal thoracotomy were compared between muscle-sparing and traditional techniques in 20 dogs. Postoperative pain was assessed based on numerical pain scores using behavioral observation, heart rate, respiratory rate, and wound palpation. Time for approaching and closure were measured, and the extent of intrathoracic organ exposure for the surgical procedures was described for each technique. There were significant differences in numerical pain scores at 2 h as well as 1, 2, 3, 4, 5, 6, and 7 days after surgery between the two groups (p < 0.0001). There was no significant (p = 0.725) difference in times for approaching and closure between the two groups. Compared to the traditional method, the muscle-sparing technique also achieved the desired exposure without compromising exposure of the target organs. Our results suggest that the muscle-sparing technique is more effective than the traditional method for providing a less painful recovery during the first 7 days after intercostal thoracotomy. Additionally, the muscle-sparing technique is as effective as the traditional modality for providing an appropriate time for approaching and closure during intercostal thoracotomy as well as adequate organ exposure for the surgical procedures.     

Thoracoscopic correction of persistent right aortic arch in a dog.

A 15-week-old, male intact, miniature schnauzer presented for signs consistent with persistent right aortic arch (PRAA). Esophagram and esophagoscopy confirmed this diagnosis. Following selective intubation, the constricting ligamentum arteriosum was visualized and completely resected via thoracoscopy. No complications were noted with this procedure. Advantages of thoracoscopy for management of persistent right aortic arch observed in this case were better visualization of the ligamentum arteriosum, minor postoperative discomfort, and minimal intraoperative hypothermia. Therefore, thoracoscopy is a potential alternative to intercostal thoracotomy for correction of PRAA.     

Patent ductus arteriosus in cats (Felis catus): 50 cases (2000–2015)

Objectives

To describe signalment, clinical characteristics, diagnostic, treatment, and outcome data in a large case series of cats with patent ductus arteriosus (PDA).

Transvenous coil embolization of patent ductus arteriosus in small (≤3.0 kg) dogs

Background: Surgical and interventional therapy for occlusion of a patent ductus arteriosus (PDA) in small dogs is challenging. Interventional closure of a PDA is rarely described in small dogs. Hypothesis: Transvenous single‐coil occlusion of a PDA in small (≤3.0 kg) dogs is possible and safe. Animals: Twenty‐one client‐owned dogs with a left‐to‐right shunting PDA. Methods: Prospective clinical study. Inclusion criteria were a left‐to‐right shunting PDA and a body weight ≤3.0 kg. Dogs with additional congenital cardiac diseases were excluded. Without arterial access, a single detachable coil was implanted by a transvenous approach with a 4 Fr catheter. Results: Twenty‐one dogs were the study population with Chihuahua and Yorkshire Terrier being the commonest breeds (n = 6 and n = 5, respectively). There were 14 female and 7 male dogs. The age range was 1.9–83.5 months (median, 7.7 months), and the body weight was 1.0–2.9 kg (1.87 ± 0.45). By angiography, the minimal ductal diameter measured 1.2–2.4 mm (median, 1.8 mm) and the PDA ampulla diameter was 2.4–5.9 mm (median, 4.6 mm). Coil implantation was successful in all dogs. After detachment of the coil from the delivery cable, repositioning of the pulmonary loop of the coil became necessary in 1 dog. The prevalence of immediate closure was 76%. The prevalence of cumulative closure was 90%. Conclusion: For an experienced cardiologist, transvenous occlusion of a PDA in small dogs is possible with a 4 Fr catheter and a commercial single detachable coil. Arterial access is not essential. The procedure is safe and successful in experienced hands.     

Evaluation of inciting causes, alternative targets, and risk factors associated with redirected aggression in cats

OBJECTIVE: To identify inciting causes, alternative targets, and risk factors associated with redirected aggression in cats. DESIGN: Case-control study. ANIMALS: 19 cats with a history of redirected aggression and 64 cats with no such history. PROCEDURES: Medical records were reviewed to identify cats evaluated for problems with redirected aggression (case cats), in which the primary inciting stimulus and alternative target of aggression were clearly identifiable. Data obtained from the records and from follow-up interviews included details about the cats and incidents of redirected aggression. Owners of control cats were interviewed via telephone to obtain similar information on their cats. RESULTS: 22 incidents of redirected aggression were reported for the 19 case cats. In 95% of those incidents, loud noises or interactions with other cats were identified as the inciting stimuli. Case cats most commonly redirected their aggression toward the owner, followed by another cat living in the same household. Compared with control cats, case cats were more likely to have a sound phobia but were less likely to be outdoor cats. In addition, case cats were more likely to be from small households (相似文献   

Tracheal foreign bodies in the cat and the use of fluoroscopy for removal: 12 cases

OBJECTIVES: To gather information to support the use of fluoroscopically guided removal of tracheal foreign bodies in cats. It was also the intent to produce a case series and look at the long-term outcome following tracheal foreign body removal. METHODS: A retrospective study was performed. This looked at cases of tracheal foreign bodies in cats seen at the University of Bristol veterinary school at Langford over an eight-year period. Outcome was assessed via telephone conversations with the owners. RESULTS: Twelve cats were presented with tracheal foreign bodies during this time. Ten of these foreign bodies were successfully removed using fluoroscopy and two using bronchoscopy. All cats survived. Follow-up was available for nine cats and showed no long-term complications. CLINICAL SIGNIFICANCE: Forceps removal under fluoroscopic guidance is a rapid, safe, and effective method for removal of tracheal foreign bodies in cats. It should be considered as an alternative to bronchoscopy for removal of tracheal foreign bodies in cats. Indeed, in cases where bronchoscopy has failed, it can be attempted to avoid thoracotomy. Successful removal of tracheal foreign bodies in cats is associated with a good long-term outcome.     

Aelurostrongylus abstrusus (cat lungworm) infection in five cats from Italy

Infection by the cat lungworm Aelurostrongylus abstrusus is considered uncommon. Here, the authors report the clinical, diagnostic and therapeutic features of five infections recently observed in Italy. All cats were under 12 months of age. All except one cat had symptomatic infections, with cough, dyspnea, and weight loss with radiographic signs of broncopneumonia. All cats were eosinophilic. Larvae were present in fresh fecal smears and on flotation exam in all cats. Baermann larval recovery permitted definitive identification and, in one case, larvae per gram of feces (lpg) counts. One dose of ivermectin (400 microg/kg) was not effective in one cat, while one dose of selamectin (6 mg/kg) was effective in one of three cases and fenbendazole at 50 mg/kg given daily for 15 days was effective in four of four cases.     

Standing Lateral Thoracotomy in Horses: Indications,Complications, and Outcomes

Objective: To describe the indications for, complications arising from, and outcome of horses that had standing lateral thoracotomy for pleural or pericardial disease. Study Design: Case series. Animals: Horses (n=16). Methods: Medical records (January 1990–December 2008) of sedated standing horses that had lateral thoracotomy were reviewed. Clinical and surgical findings, perioperative and short‐term complications were recorded. Long‐term (>6 months) outcome was determined through telephone conversations with owners and veterinarians. Results: Mean (±SD) horse age was 6.6±5.3 years (range, 1–15 years). Thoracotomy was most commonly for treatment of recurrent or chronic pleural infection (94%). Anaerobic bacteria were frequently isolated from pleural effusion associated with pleuropneumonia (63%). Right lateral intercostal thoracotomy was performed in 13 horses (82%); intercostal muscle myectomy in 5 horses; and rib resection in 1. Perioperative complications were hemipneumothorax (2 horses) and short‐term complications included cellulitis and abscessation of the thoracotomy site (6 horses). Fourteen (88%) horses survived to discharge and 46% of horses that survived returned to their previous level of athletic activity. Conclusions: Lateral thoracotomy is well tolerated by standing sedated horses with minimal perioperative and short‐term complications. Clinical Relevance: Standing lateral thoracotomy should be considered for the treatment of complicated pleuropneumonia in horses.