2016 SPRING: Minimally Invasive Surgery | Brachycephalic Syndrome | Laryngeal Paralysis | Indications for Arthroscopy | Cold Soaks? | Continuing Education
Minimally Invasive Surgery: Maximization with Minimal Invasion
Video endoscopy, or minimally invasive surgery (MIS), provides some of the most useful tools for diagnosis and definitive treatment in small animals. Routine surgical procedures include examination of the following cavities and associated organs/structures: joint spaces (arthroscopy), thoracic cavity (thoracoscopy) and abdominal cavity (laparoscopy).
The benefits of MIS are well established in laboratory, human and clinical veterinary medicine. Benefits include less surgical trauma, pain, stress and morbidity; lower infection rates; and decreased length of hospitalization. The magnified and illuminated endoscopic view improves diagnostic capabilities over traditional and initial diagnostics (e.g., elbow incongruity), provides better sample sizes (e.g., laparoscopic liver biopsy versus needle aspirate cytology or Tru-cut® biopsy), and allows visualization of areas not accessible via traditional “open” exploration (e.g., transurethral evaluation for stones during laparoscopic-assisted cystotomy).
Laparoscopic liver biopsy of a diffusely mottled liver
Thoracoscopic exploration of the caudal thorax
Laparoscopic procedures performed most frequently at BluePearl include laparoscopic-assisted prophylactic gastropexy and ovariohysterectomy; laparoscopic liver biopsy; ovarian remnant removal; and cryptorchid castration. Owners of dogs predisposed to gastric dilatation volvulus (GDV) are particularly interested in and grateful for a minimally invasive prophylactic gastropexy, which can readily be performed at the time of spay (via laparotomy or laparoscopy). This is especially true if the family has previously lost a dog secondary to GDV. Less frequently performed laparoscopic procedures such as transvesicular percutaneous cystolithotomy, cholecystectomy (non-ruptured gall bladder mucocele), adrenalectomy (left primarily), laparoscopic-assisted intestinal resection-anastomosis (focal masses identified via ultrasound), lymph node biopsy, and nephrectomy are areas of interest and will likely be performed in upcoming cases.
Thoracoscopic procedures performed most frequently at BluePearl are subtotal pericardiectomy/pericardial window (heart base or atrial/auricular tumors, idiopathic pericardial effusion, etc.). Less frequently performed thoracoscopic procedures include lung lobectomy (neoplasia), exploration and lung parenchymal biopsy (and bacterial/fungal cultures). Thoracoscopic thoracic duct evaluation and ligation (in dogs) is an area of interest recently and will likely be performed in upcoming cases.
Minimally invasive surgery is an underutilized but growing component of veterinary surgery. There is a clear benefit to the patient that undergoes MIS. Pet owners are becoming more aware of and seeking the benefits and availability of MIS. Case selection is an important consideration for the practitioner and surgeon as poor case selection can result in less than ideal outcome and/or need for conversion.
As we come out of winter’s hibernation and move into these spring and summer months we start to see a trend in our canine population. Along with the increase in orthopedic ailments that manifest as a result of increased activity following months of lazing on the couch, we also begin to hear that familiar stridorous sound associated with an increased respiratory effort.
Laryngeal paralysis is a condition seen primarily in middle to large breed dogs and results in a mechanical upper airway obstruction that inhibits normal airflow through the larynx and into the lower respiratory tract. Although not strictly a concern in the summer months, the activities and panting that accompany the warmer temperatures can certainly appear to exacerbate symptoms of laryngeal paralysis.
Laryngeal paralysis results from a paralysis or paresis of the intrinsic muscles of the larynx thus inhibiting abduction of the arytenoid cartilages and vocal folds during inspiration. The condition is usually not diagnosed until it becomes bilateral and the airway becomes significantly compromised.
Surprisingly, while most cases of laryngeal paralysis are acquired, there are certain breeds that have been shown to develop the condition congenitally such as the Bouvier de Flanders, bulldog, Siberian husky and associated mixed breeds.
Congenital laryngeal paralysis typically presents in dogs less than 2 years of age, whereas the acquired form is seen in middle aged to older dogs. The etiology is most often idiopathic, although it has been found to be associated with cervical tumors, tracheal collapse, hypothyroidism and other neuropathic or neuromuscular disorders. In fact, there is a line of thinking that suspects “lar par,” as it is colloquially known, is a precursor to a Lou Gehrig’s (amyotropic lateral sclerosis) disease-like condition in dogs. Although much less common, laryngeal paralysis can also be seen in cats.
As you are likely familiar, clinical signs are a result of poor laryngeal function and can begin with subtle signs such as a change in bark, exercise intolerance, noisy breathing or coughing (usually after eating or drinking). As the condition progresses or becomes bilateral, acute respiratory distress may ensue including respiratory stridor, collapse, cyanosis and hyperthermia. Not surprisingly, the condition may be exacerbated or an acute episode triggered by hot and humid weather. Patients may also present with increased lower respiratory sounds and low grade fever suggestive of aspiration pneumonia which is not uncommon due to the impaired protective function of the larynx.
Diagnosis is based on history, a “characteristic” upper airway stridor and on oral examination of the larynx. Although some debate exists about the appropriate drug protocol, light sedation is required to examine the larynx adequately, and propofol is an excellent short-acting anesthetic to view the upper airway. (Sometimes the addition of dopram can be helpful). Drugs such as ketamine or mixtures thereof should be avoided. Initial workup should include a complete blood count, chemistry profile and thyroid profile. Chest and cervical radiographs are also wise to look for signs of aspiration pneumonia and rule out other physical causes.
Differential diagnoses for upper respiratory stridor include oral or cervical masses, upper respiratory inflammation or foreign bodies. Occasionally, tracheoscopy may be recommended if signs and symptoms are ambiguous. There are often two clinical presentations that may appear at our door. Either there is a pet whose presenting complaint is a change in bark with progressive exercise intolerance or the patient is in acute respiratory distress with collapse, cyanosis and hyperthermia. Ideally, cases presenting in distress are stabilized with steroids, intravenous fluids, sedatives and oxygen. In rare instances, respiratory distress cannot be alleviated, and immediate surgical intervention may be required.
While there are several methods to surgically correct laryngeal paralysis, the technique of choice is a unilateral arytenoid lateralization (i.e. laryngeal tie back procedure or laryngoplasty). This procedure has the highest rate of success with the lowest rate of complications. Although infrequent, the primary complication encountered is aspiration pneumonia. This can occur preoperatively, particularly in cases presenting with acute distress, or postoperatively due to altered airway protection. In general most patients do very well postoperatively and are often sent home the very next day! Post-operative management includes halter leads instead of neck leashes, canned food or moistened dry food, and reduced activity particularly during hot or humid weather. These management recommendations likely need to be maintained for the remainder of the pet’s life. Thankfully, 90% or more of dogs undergoing this procedure will have improved respiratory function and exercise tolerance.
If you have a case of progressive upper respiratory stridor or suspect laryngeal paralysis, please feel free to call the surgery team at BluePearl Veterinary Partners.
“Brachycephalic syndrome” is a combination of anatomic congenital abnormalities that result in varying degrees of upper airway obstruction. Predisposed breeds such as English bulldogs, pugs, and shih tzus, as well as brachycephalic cats, like Persians, exhibit facial features resulting in a shortened maxilla. Abnormalities include stenotic nares, abnormal nasopharyngeal turbinates, elongated soft palate and hypoplastic trachea. Secondary sequela of an increase in upper airway resistance may be mucosal edema, everted laryngeal saccules, laryngeal collapse and everted tonsils. Stenotic nares, elongated palate and everted saccules can be addressed surgically. However, hypoplastic trachea is a non-surgical component of the syndrome. Laryngeal collapse occurs as a secondary change due to the altered airflow and progressive deterioration and malacia of the laryngeal cartilages. Hiatal hernias and non-cardiogenic pulmonary edema can also develop in chronic or severe cases of upper airway obstruction.
Pre-operative image of bilateral stenotic nares
Postoperative image of a bilateral performed alarplasty showing widened nares
Clinical signs may include stertor, stridor, inspiratory dyspnea, exercise intolerance or in severe cases syncope. These signs may be exacerbated by exercise and/or warm temperatures and may result in life threatening conditions such as cyanosis or severe hyperthermia. Patients may also exhibit gastrointestinal signs such as hypersalivation, vomiting and/or regurgitation that may result in concurrent aspiration pneumonia.
Diagnosis of brachycephalic syndrome is often based on breed and clinical signs. Stenotic nares are appreciated on physical examination; however, diagnosis of the remaining anatomic abnormalities requires further diagnostics. Three-view thoracic radiographs are recommended to evaluate tracheal diameter as well as for evidence of lung pathology (e.g. aspiration pneumonia, non-cardiogenic pulmonary edema). A sedated laryngeal exam is required to evaluate the oral cavity, in particular the soft palate, laryngeal saccules and larynx for signs of collapse. Use caution to not place excessive traction on the tongue during laryngeal exam as this can create an artifactually elongated palate. This exam is generally done immediately prior to intubation for surgical correction.
Surgical treatment of obstructive upper airway abnormalities is best performed at an early age prior to the development of secondary changes such as laryngeal collapse and hiatal hernia. Surgery should be performed in a facility with appropriate monitoring equipment as well as the means to perform a temporary tracheostomy if necessary. Stenotic nares may be surgically addressed using one of several techniques that involve removal of alar tissue and widening of the nasal openings. Elongated soft palates are amputated at the level of the epiglottis. Depending on surgeon preference this may be performed using a scalpel, Ligasure™ or CO2 laser. Everted saccules can be retracted and resected without mucosal closure required. Given the risk of subsequent laryngeal/pharyngeal swelling, postoperative hospitalization and monitoring for respiratory distress is necessary. Steroids may be administered to limit postoperative inflammation. In rare cases, a temporary tracheostomy may be required until postoperative inflammation resolves.
Prognosis is good-excellent for young patients that receive early intervention to alleviate upper airway obstruction. While these patients will never have a normal airway, surgical intervention can significantly improve their quality of life. For older patients with prolonged clinical signs that go on to develop laryngeal collapse, the prognosis is guarded with or without surgical intervention.
BluePearl Veterinary Partners is a leader in upper airway procedures. A member of the surgery team is on-call 24/7 to provide consultations to our emergency doctors and to perform emergency surgeries when on call. Our specialists are available for questions and consultations on surgical conditions Monday through Saturday.
Indications for Arthroscopy
Veterinary arthroscopy has gained popularity and enhanced our ability to diagnose and treat many orthopedic diseases, including pathology of the shoulder, elbow, carpus, stifle and hock.
Arthroscopy offers several advantages over traditional surgery, including:
- Better visualization of structures within the joint by magnification
- Minimal invasiveness and decreased pain
- Rapid recovery
Shoulder osteochondritis dissecans (OCD)
Shoulder arthroscopy is commonly used to diagnose and treat OCD, which often presents as a unilateral lameness in young, large-breed dogs. However, the contralateral limb is also affected in a large percentage of dogs.
Following bilateral radiographic screening, arthroscopy is ideal for confirming the diagnosis and definitive treatment of OCD. After arthroscopic removal of the cartilage fragments, curettage is performed within the articular cartilage defect to stimulate fibrocartilage healing. Patients recover rapidly after this procedure.
Prognosis for OCD of the shoulder is good to excellent.
This condition often presents as a unilateral lameness that may be chronic and progressive in a middle-aged or older medium to large breed dog. Arthroscopy may identify a partial or completely torn biceps tendon and/or fibrous proliferation and osteophyte formation within the bicipital groove. Treatment includes biceps tendon release. Patients treated for biceps tenosynovitis have a good to excellent prognosis if pathology within the shoulder joint is limited.
Capsular or ligamentous injury leads to a chronic unilateral lameness, which is often worse after exercise. This condition occurs in middle-aged dogs of any breed and size.
Diagnosis can be challenging and often requires heavy sedation and palpation for laxity. Radiography identifies non-specific findings. Arthroscopy is recommended to rule out other joint pathology and to confirm joint capsule and ligamentous tears.
Gross instability requires surgical stabilization with ligament reconstruction, now commonly performed using bone anchors and nonabsorbable suture material. The prognosis for treatment of instability by arthroscopy and surgery is good if mild to moderate disease exists but may be only fair with advanced disease.
Elbow dysplasia is commonly characterized using arthroscopy following identification on radiographs. Components of elbow dysplasia often diagnosed by arthroscopy include fragmented medial coronoid process (FCP), OCD, ununited anconeal process (UAP) and elbow incongruity.
Fragmented medial coronoid process (FCP)
Since FCP is poorly recognized on radiographic examination, it often goes undiagnosed, which leads to progressive osteoarthritis. Early diagnosis, prior to advancement of osteoarthritis and subsequent treatment by medial joint assessment and removal of the fragment along with medial coronoidectomy, usually improves limb function.
Secondary humeral condylar osteochondrosis, known as a kissing lesion, cannot be seen on radiographs is often also assessed and treated by articular cartilage curettage.
Large fragmented medial coronoid process. Note pathology of full thickness articular cartilage defects of the humeral condyle (kissing lesion).
OCD of the medial humeral condyle is often identified on radiographs but is best further characterized by arthroscopy. Once identified, the OCD flap can be removed from its articular bed by graspers, followed by curettage of the subchondral bone defect. Again, most patients have improved limb function following flap removal, but this varies based on prior degenerative joint disease (DJD) presence.
UAP is usually recognized using radiography and treated either by anconeal fragment removal or lag screw fixation. Arthroscopy can be used to assist in assessment for other joint pathology and particularly identifies a UAP lesion as a line of fibrous tissue and irregular cartilage between the anconeus and the ulna.
Lastly, elbow incongruity is a disease with controversy surrounding the ideal diagnostics. It may be assessed by alignment of the radial head and ulnar trochlear notch for step defects. Since this condition is often thought to contribute to FCP, UAP and secondary humeral condylar osteochondrosis, medial coronoidectomy may be considered to alter the joint biomechanics, particularly unloading the medial joint. The outcome is often based on prior DJD advancement and may be fair to excellent.
Cranial cruciate ligament tear (partial)
Arthroscopy may be used for identification of cruciate ligament and meniscal pathology in the stifle. In cases of suspected cranial cruciate ligament disease that are lacking signs of instability, assessment of the ligament for partial or complete tearing can be done arthroscopically. Additionally, medial meniscal disease may occur before or after stifle joint surgical stabilization. Arthroscopic assessment and treatment of meniscal disease by debridement can be done with limited morbidity. Other indications for stifle arthroscopy include diagnosis and treatment of OCD of the lateral and medial femoral condyles, treatment of septic osteomyelitis and placement of transarticular pins.
Since the institution of arthroscopy, assessment of canine and feline joint pathology, disease recognition and treatment outcomes have been enhanced. Shoulder, elbow and stifle joints have numerous pathologies, which benefit greatly from the reduced morbidity and recovery time associated with arthroscopy. Early identification of joint pathology and referral for further diagnostics and treatment will undoubtedly benefit patients, preventing progression of joint disease.
At BluePearl Veterinary Partners, our team is excited to offer arthroscopy to your patients. If you have a case that you feel may benefit from arthroscopy and would like to discuss the options, please do not hesitate to call. Our specialists are available for questions and consultations on surgical conditions Monday through Saturday.
Cold Soaking Your Instruments? Time for a Change
Many practices keep surgical instruments soaking in a disinfectant solution, also called a cold soak, to be used during minor surgical procedures such as lacerations or to debride contaminated wounds. Most veterinarians say they use cold soaks because they are convenient and practical. The number of times that only a surgical blade handle, thumb forceps and needle holder are needed outweighs the time spent resterilizing them or the cost of buying multiple instrument sets.
Maybe that was a good reason in the old days, but times have changed. This is the era of the resistant superbug. The risk of spreading infection from one patient to another due to inadequate instrument cleaning or maintenance of the cold disinfectant far outweighs these practical matters. Pathogenic organisms, such as methicillin-resistant Staphylococcus aureus, are not only a risk to your patients but also to you.
What’s wrong with cold soaks?
It is not uncommon for instruments to be inadequately cleaned prior to being placed back into the disinfectant. Many disinfectants won’t work in the presence of dirt and debris. Placing wet instruments into the cold soak serves to dilute out the disinfectant reducing its efficacy. The disinfectants in cold soaks also need to be replaced on a regular schedule or they will lose effectiveness. In addition, instruments need to remain fully submerged in the disinfectant for an adequate period of time, sometimes hours, for pathogens to be killed. Finally, many pathogens are, or have the ability to become, resistant to the disinfectants being used in cold soaks.
A recent study in the Can Vet J (Murphy et al 2010) found that 13% of what were considered well kept disinfectant solutions for the cold soaking of instruments contained bacteria, including opportunistic pathogens. Cold soaking instruments in disinfectant solutions is not the same as sterilizing instruments with gas or in an autoclave.
FROM THE MEDICAL DIRECTOR
Medical Director Notes
If we did not have winter, the spring would not be nearly as pleasant! As we spring ahead, 2016 is shaping up to be a very exciting year for BluePearl in Waltham.
After a couple of grueling months spent studying for surgery boards, we are pleased to announce that Dr. William Snell has passed his boards and is now a Diplomate of the American College of Veterinary Surgeons! Given his special interest in minimally invasive surgery, we have purchased additional laparoscopic and thoracoscopic equipment, and we are excited to be able to offer these procedures to our referral community. Dr. Snell will be giving a continuing education lecture this year on minimally invasive surgery, and we hope to see all of you there. He will also be offering the lecture as a CE Delivered to Your Door, which means he can present the lecture at your practice at a time that is convenient for your team.
We are also excited to announce the addition of a full time ophthalmologist, Clara Williams, DVM, DACVO who will begin seeing patients the last part of April. At the end of the summer, we will be adding another doctor to both our cardiology and critical care teams. Jodi Melvin, our veterinary relations coordinator, will be visiting your hospitals and introducing our new doctors.
Communicating with you remains our top priority, and we will be offering the BluePearl Portal to you early this summer. The portal provides password-protected, internet access to our medical records for past and present patients referred to our hospital by members of your clinical team. Records will be accessible 24/7 through our website – and, based on your preferences, you may elect to also receive faxes and/or email messages. Look for more information in the near future.
As always, we appreciate your continued support of the hospital, and we look forward to providing additional services to further meet your referral needs. We continue to stand by our commitment to you:
- We are committed to exceptional patient care and client service.
- We operate strictly by referral.
- We will call and mail you a written report for every referral.
- We do NOT provide routine, general or prophylactic care.
- We are happy to consult on cases with you whenever you call.
Kristina DePaula, DVM, DACVECC
BluePearl is strongly committed to the veterinary community. One of the ways we demonstrate this commitment is through our continuing education program, which is subsidized in part by our Partners in Education.
All BluePearl CE lectures are free and and include a light dinner 30. Please RSVP to Jodie Melvin at 781.684.8387, or firstname.lastname@example.org. For the most current information about BluePearl CE, please check our online calendar regularly for the most current information.
|May 11||7:00PM||Tech||Urinary Catheter Placement|
Amy Breton Newfield, CVT, VTS (ECC)
|The Septic Patient|
Amy Breton Newfield, CVT, VTS (ECC)
|Jun 23||7:00PM||Doctor||Laparscopic and Thorascopic Surgery: Minimally Invasive Techniques|
Maximization with Minimal Invasion
William Snell, DVM, DACVS-SA
|Sep 29||7:00PM||Doctor||Cardiology and Critical Care: TBA|
Kristina DePaula, DVM, DACVECC &
Kursten Roderick, DVM
|Oct 5||7:00PM||Tech||How to Avoid Bites and Scratches|
Amy Breton Newfield, CVT, VTS (ECC)
|BluePearl Waltham||1 hr|
|Pet Puzzlers: Interactive Case Review of Puzzling Cases|
Leslie Schwarz, DVM, DACVR &
Bari Spielman, DVM, DACVIM
|BluePearl Waltham||2 hr|