Surgery Procedures

Cranial Cruciate Ligament (CCL) Rupture

What is a cruciate ligament?

There are two ligaments in the stifle (knee) that are called the cruciate ligaments because they cross each other. One runs from the back of the femur (thigh bone) to the front of the tibia (shin bone). This one is called the cranial cruciate ligament (CCL). The other one runs from the front of the femur to the back of the tibia and is called the caudal cruciate ligament. Cruciate ligaments are important for the hinge joint function of the stifle joint. They help to keep the stifle aligned, and the CCL especially prevents internal rotation of the stifle, forward displacement of the tibia, and hyperextension.

What is a cranial cruciate ligament tear?

A cranial cruciate ligament (CCL) tear in dogs is similar to an ACL tear in humans. It can be an abrupt tear during trauma or the result of strenuous activity. However, it can also be a slow deterioration of the ligament over weeks or months, potentially affecting both knees. Following a CCL tear, the limp is usually quite severe. While some improvement may occur with time, surgery is the desired method of treatment for most dogs and cats. Over the past 30 years, numerous surgical techniques have been developed to help correct the instability created by a CCL tear. In cats, small-breed dogs, and some older, large-breed dogs, we usually perform a surgical technique that is referred to as a standard cruciate repair. Following removal of the torn CCL, a synthetic ligament is created. Stability of the stifle is immediate following surgery but most pets will not fully use the leg for several weeks. A combination of strict rest and physical therapy will aide in the pet’s recovery and in the ultimate use of the leg. While the standard repair may be performed in medium- and large-breed dogs, a tibial plateau leveling osteotomy (TPLO) is typically the best option for these dogs.

What is post-operative care for a cranial cruciate ligament tear?

Strict rest is required following surgery to allow for proper healing of the surrounding soft tissues. Initially, there should be no running, jumping, or playing. After the first month of strict rest, controlled activity may be gradually introduced for three months following surgery. Physical therapy is also suggested to aid the healing process.

What are the risks or complications with this surgery?

There are a few risks or complications with stifle surgery. Be sure to discuss them at your appointment. At that time, we should have pertinent blood work on hand to assess the risk for general anesthesia. The risk is usually very low for healthy animals with normal blood work. That risk is further reduced by local pain control during anesthesia, which is accomplished by an epidural anesthesia. Most complications are minor in nature. With some minor complications, additional medications or other forms of physical therapy may be required. Complications such as infection, suture reaction or reaction to the artificial ligament, tearing of the artificial ligament, or future meniscal tearing are possible. Major complications, those requiring additional surgery, are rare. As long as the activity restrictions are adhered to, the chance that additional surgery will be needed is low.

Can the leg be re-injured following surgery?

After the healing is complete, it is rare for problems to develop. However, it is not unusual to see an occasional limp in some dogs for several months following surgery. Some dogs will have already developed arthritis in the affected stifle or will develop it post operatively; this could lead to a source of occasional stiffness or limping in the future.

Laryngeal Paralysis

The opening to the trachea (“wind pipe”) normally is pulled open on two sides when breathing in, and relaxes when breathing out. In dogs and cats with laryngeal paralysis, the muscles that normally pull the airway open do not function properly. When an affected pet breathes in, the walls of the airway do not pull open—rather, they are sucked into the opening, or in severe cases sucked shut. Early in the condition, this creates increased noise when they breathe; later, it can completely obstruct their airway, and they can suffocate.

The early signs of laryngeal paralysis can be quite subtle. You may notice:

-harshness in their panting
-increased panting or panting when cool and calm
-a hoarse or raspy-sounding bark

Many different approaches have been used to surgically treat laryngeal paralysis. Over the years and through the monitoring of many post-operative patients, one technique has remained at the top of the list of procedures with good success and few complications, the Unilateral Arytenoid Lateralization or “Tieback”.

In the tieback procedure, a suture is used to permanently pull the wall of the airway open on one side of the larynx. To minimize the chance of fluids or food entering the airway, only one side is pulled open enough to prevent airway compromise and future breathing crises.

In the hands of an experienced ACVS board-certified veterinary surgeon, this is typically a relatively straight-forward, minimally invasive surgical procedure. The incision is only 3-4 inches on one side of the neck and well-planned pain management can reduce or eliminate post-operative pain directly associated with surgery.

There are several other surgical treatment options that your veterinary surgeon may discuss with you. These options are usually considered if a tieback is not a viable option. Talk with your primary care veterinarian and pursue a consult with a veterinary surgeon to fully explore your options.

Contact us for more information about this procedure.

Limb-Sparing Procedures

In pets that develop a malignant cancer affecting a limb, complete excision of the tumor is often the best option to improve comfort, extend longevity, and/or potentially cure the condition. Depending on the size, location, and type of cancer affecting the limb, in some cases amputation of the limb is recommended to achieve complete removal. Although most patients tolerate limb amputation surprisingly well, it is not an option for all animals.

Limb sparing is a broad term referring to various surgical treatments for cancer in the limbs of animals where complete amputation would normally be recommended but is not possible due to concerns of concurrent orthopedic or neurologic conditions or poor expected recovery.

What does limb sparing entail?

Because limb sparing is a general term encompassing a wide-variety of surgical and therapeutic techniques, the possible options for treatment are largely dependent on each patient. A variety of cancers may affect the pet’s limbs and, based on the type, may have varying tendencies to spread locally at the site of occurrence (invasion) or spread to other locations in the body (metastasis). Surgical removal of a primary tumor may either be performed with the intent of curing the disease through complete removal, or may be performed to reduce pain associated with the primary tumor and prolong survival in cases where metastasis and future recurrence is expected.

Tumors of Soft Tissue

Treatment of malignant soft tissue tumors is typically focused on local control through the complete excision of the tumor, if possible, including wide margins of apparently normal tissue to catch any direct microscopic spread of the disease. Guidelines for soft tissue tumor excision are dependent on tumor type and grade; however, they typically include wide (2-4 cm) margins of normal tissue around the tumor. This may be a difficult feat when removing tumors from the body and extremely challenging on tumors of the limb where vital muscles and nerves lie close to the surface beneath a comparatively tight layer of skin. Veterinary surgeons are specially trained in techniques for the reconstruction and closure of the wounds resulting from tumor excision, including skin advancements, flaps, and grafts. Following tumor excision, additional therapies may be recommended, including radiation and/or chemotherapy.

Tumors of the Bone

Although there are multiple tumors than can affect the bones, the most common bone tumor seen in veterinary patients is osteosarcoma. This tumor type is typically destructive of the bone at the site of the growth and has a high rate of metastasis to other areas of the body. Historically, treatment of osteosarcoma was primarily through limb amputation because the tumor may be extremely painful and may cause destruction that weakens the affected bone, leading to fractures.

Using the limb-sparing principles, excision of only the affected portion of the bone may be possible, combined with various stabilization procedures, including bone plate fixation, bone graft placement, and bone distraction techniques. Following surgery, additional therapies may be recommended, including chemotherapy and/or radiation. The ability to utilize a limb- sparing procedure depends on multiple factors, including the location of the tumor and the degree of tumor invasion into the surrounding tissues.

Partial Amputations and Prosthetics

Due to advances in prosthetics for veterinary patients, in some cases of disease affecting the extremities of limbs, partial amputation can be performed and combined with an internally implanted or externally applied prosthetic device that provides the pet with a functional, weight-bearing limb. To improve the outcome and acceptance of prosthetics, physical therapy is a crucial component of the recovery process.

What pets are candidates for limb sparing?

The decision to pursue a limb-sparing procedure requires a treatment plan designed for the individual pet’s needs and based on the input and consensus of the primary veterinarian, surgeon, oncologist, and, most importantly, the pet owner. Planning for treatment may require specific pre-operative staging and testing, including advanced imaging techniques, such as a CT scan or MRI, and consultation with a radiologist.

As surgery requires general anesthesia, bloodwork is required to assess your pet’s health and must be performed within two weeks of the date of the procedure. Ensuring appropriate pain management is a high priority both during and after surgery.

Complications following surgery are dependent on the type of procedure performed. Possible complications associated with oncologic surgery include the risk of local re-growth of the tumor, metastasis, incisional dehiscence, swelling, or infection, and, in some cases, implant failures or fractures. Your surgeon will discuss the particular risks and complications associated with any procedures that are planned for your pet.

What is the post-operative recovery and care?

After surgery, activity restriction is typically required to allow for healing, with no running, jumping, or playing permitted for a period of time dependent on the procedure. Additional treatments may be recommended through the medical or radiation oncologist.

Physical therapy may be recommended for the pet following surgery, and may include treatments to decrease swelling or post-operative pain and help encourage usage of the limb, as well as a home-exercise plan and appointments with the rehabilitation practitioner, dependent on your pet’s needs.

Medial Patella Luxation (MPL)

Medial patella luxation is a condition where the patella (knee-cap) does not stay in its normal position in the groove on the end of the femur (thigh bone) and will pop-out, or luxate, to the medial (inside) surface of the knee.

What causes medial patella luxation?

To understand the cause of medial patella luxation (MPL), we need to understand a little of the anatomy of the knee. Surprisingly, the structure of the knee joint is similar between dogs, cats, and humans. The patella is a small bone in the knee joint that functions as part of a “pulley-mechanism” to extend the knee. When the quadriceps muscles of the thigh contract, they pull on a strong tendon that crosses the knee joint and inserts on the front of the shin bone (tibia). The patella is a small bone within this tendon and it normally slides in a groove on the end of the femur. When the patella stays within this groove, extension and flexion of the knee can occur smoothly. When it pops out of the groove, the extensor mechanism malfunctions, pressure distributions across the knee are altered, and lameness can occur.

MPL may be due to a combination of congenital and anatomic variations as well as trauma, and can often affect both hind limbs simultaneously. Congenital causes are most common in small- and toy-breed dogs, including Maltese, Poodles, Yorkshire Terriers, and others. This is most likely due to changes in their anatomy that come along with centuries of breeding to produce these small dogs from their original wolf ancestors. Larger breed dogs and cats may also be affected by medial patella luxation, however, due to trauma or congenital causes.

Signs of MPL are dependent on the cause and severity of the condition. If due to congenital changes, it is usually first noticed around 6 to 12 months of age and may become progressively worse or more frequent over time. Typically, pets that have suffered MPL experience sudden, non-weight-bearing lameness, which may quickly and completely resolve after a few hops or after stretching the leg into extension. Mild cases may never show clinical signs. In more severe cases, persistent and severe lameness and pain are often noted.

How is medial patella luxation diagnosed?

Medial patella luxations (MPLs) are diagnosed based on physical examination by a veterinarian. In some cases, X-Rays are helpful to confirm the diagnosis and to evaluate for other concurrent conditions. MPLs are graded on a scale of severity from 1-4. Grade 1 is the most mild, with the patella in place most of the time but able to be manually luxated during examination when pressure is applied. Grade 2 luxations will occur spontaneously, with the patella popping freely into and out of the groove. Grade 3 luxations mean the patella is luxated at most times but can still be replaced manually into the groove. Grade 4 luxations are the most severe, as they indicate that the patella is permanently out of its groove and cannot be replaced without surgical intervention. Grade 2 and higher luxations are typically progressive over time, as the repeated luxation of the patella leads to wear on the bone and the development of arthritis, as well as other changes to the bones and muscles of the limb. For this reason, it is typically recommended to perform surgical repair of clinical grade 2 or higher luxations.

MPL may also be seen concurrently with other conditions, especially injuries to the cranial cruciate ligament (similar to the ACL in humans). This is because the patella and its associated ligament are strong stabilizers of the knee joint, and if they are not in their normal position, the other, smaller structures may be at risk for injury.

How is medial patella luxation treated?

Medial patella luxation (MPL) of grade 2 or higher typically requires surgical treatment. In most cases, surgical treatment involves several mini-procedures performed together during a single surgery. These procedures may include deepening the groove of the end of the femur, releasing muscles that are placing excessive medial strain on the patella, tightening the soft tissue (ligaments and fascia) that hold the patella in place, and adjusting the insertion point of the patellar tendon on the tibial crest (front portion of the shin bone). The latter procedure involves making a small cut in the bone, which allows the tendon to be transposed, and securing the bone in place with stainless steel pins. MPL corrections may also be performed in conjunction with stabilization procedures for CCL tears, if required.

Because surgery requires general anesthesia, bloodwork is required to assess the pet’s health and must be performed within two weeks of the date of the procedure. Pain management is a high priority both during and after surgery and may include a combination of therapies.

Complications following surgery are usually mild and associated with incision redness, swelling, or bruising. Rarely, re-luxation of the patella can occur post-operatively, requiring an additional surgical repair; however, this is typically limited to the most severe luxation grades. Some animals will reject the metal pins placed to transpose the tibial crest over time, which leads to the pins backing out of the bone, typically within the first three to 12 months. If this occurs, the pins can usually be removed through a minor procedure.

What is the post-operative recovery and care?

After surgery, strict activity restriction is required to allow for healing, with no running, jumping, or playing permitted. Dogs will often begin using the operated leg in the first one to two weeks following surgery. The total healing period is typically two to three months, during which your pet will be allowed to experience gradually increasing walks and exercise under the guidance of the surgeon and rehabilitation practitioner.

Physical therapy is a key component to the pet’s smooth recovery, improving comfort, encouraging normal usage of the limb, and maintaining or improving muscle mass. Physical therapy is typically started in the first seven to 14 days following surgery, and may include a home exercise plan or appointments with the rehabilitation practitioner, dependent on the pet’s needs.

Osteochondritis Dissecans (OCD)

What is osteochondritis dissecans?

Osteochondritis dissecans (OCD) is an abnormality in the development of bone from cartilage. As a result, within joints such as the shoulder, elbow, knee, and hock (ankle), a flap of cartilage can develop causing lameness. The shoulder and elbow are more commonly affected. The development of OCD is secondary to multiple factors, including diet, growth rate, genetics, trauma, hormonal imbalance, and joint architecture.

As genetics play an important role in the development of OCD, any patient diagnosed with this condition should not be bred. In addition, parents, siblings, or previous offspring of an affected patient should not be bred.

Which pets are most commonly affected?

Osteochondritis dissecans (OCD) frequently occurs more in large and giant breeds. Most commonly affected breeds include Labrador Retrievers, Golden Retrievers, and Newfoundlands, as well as Bernese Mountain Dogs, Chow Chows, German Shepherds, Mastiffs, Old English Sheepdogs, Rottweilers, and Standard Poodles.

In cases such as OCD of the shoulder, male dogs are more commonly affected than female dogs.

How is it diagnosed?

Most dogs will start showing clinical signs as young as 4 to 7 months of age. Most are recognized to have a lameness that becomes worse with heavy exercise and after prolonged rest. In some cases, no obvious affected leg can be determined, as osteochondritis dissecans is in both limbs.

X-Rays are often diagnostic, but in more difficult cases other tests, including arthrography (X- Rays with contrast within the joint), CT scan, or MRI, may be used.

What is the treatment and prognosis?

Surgery or arthroscopy will often be the treatment of choice for osteochondritis dissecans. Factors that may affect this decision include the joint affected, the degree of secondary arthritis, or if a flap of cartilage is not present. The goal of surgery is to retrieve the flap of unhealthy cartilage and prepare the area where the flap developed to allow a scar-type cartilage (fibrocartilage) to develop.

In the shoulder: Surgery or arthroscopy is the treatment of choice. Seventy five percent of patients will show no signs of lameness after surgery, 23 percent show mild lameness, and 2 percent show persistent lameness.

In the stifle (knee): Surgery is indicated if a large fragment is recognized. Chances for complete resolution of lameness are small.

In the tarsus (ankle): Most dogs will show mild improvement in lameness immediately following surgery but will continue to show some gait abnormalities once they have returned back to normal activity levels.

What is the post-operative care?

Following surgery, patients should be restricted to leash confinement for a minimum of four weeks. Over the next four weeks, controlled activity may be gradually increased. Pain management with non-steroidal anti-inflammatory drugs will usually continue for the first four to seven days after surgery. Long-term management, whether surgery was performed or not, includes weight restriction, controlled exercise, and pain management as needed.

Perineal Hernia

A hernia is an abnormal opening through which an organ or tissue protrudes. A perineal hernia (PAH) results from a weakening of the muscles that support the rectum (pelvic diaphragm). These hernias begin to bulge when they fill with fat, abdominal tissue, or the urinary bladder, or when part of the rectum slides into the pocket.

What are the causes?

There are a number of possible causes for perineal hernias. It is believed that intact male dogs, due to their often enlarged prostate, exert more pressure when urinating and defecating, and the tissues around the rectum eventually stretch, weaken and then tear, resulting in a perineal hernia. Some veterinarians also speculate that hormonal differences in intact male dogs predispose to perineal hernias; as such, hernias are far less common in castrated dogs.

Which breeds are predisposed and what are the symptoms?

Perineal hernias are most common in middle-aged and geriatric intact male dogs and are rarely seen in cats. The breeds that are most commonly affected are Boston Terriers, Boxers, Welsh Corgis, Pekingese, and Dachshunds. When a perineal hernia occurs in a cat it can be a primary problem or secondary problem associated with megacolon. Megacolon is a condition where the colon becomes dilated and causes constipation and straining and should be considered in all cats that have a perineal hernia. More than 30 percent of perineal hernias occur on both sides of the rectum.

The most common symptoms of a perineal hernia are swelling beside the rectum, constipation, and straining to defecate. Other symptoms are painful defecation, fecal incontinence, altered tail carriage, and straining to urinate.

How is it diagnosed?

Diagnosis is based on history and physical examination. A rectal examination and palpation is necessary to assess the pelvic diaphragm musculature. If the rectal examination reveals an enlarged prostate, a cause must be determined. Benign hyperplasia (enlargement), tumor, abscess, and prostatic or paraprostatic cysts must be considered, and additional diagnostics, such as ultrasound, may be indicated in order to treat the underlying cause.

What are the treatment options?

If the clinical signs associated with a perineal hernia (PAH) are minimal, conservative treatment is an option but is rarely successful in controlling the clinical signs long term. Conservative therapy would include a high fiber/moist diet, stool softeners, and manual removal of impacted feces.

Surgery is the treatment of choice. As indicated above, hormonal changes in the older intact dog have been shown to be associated with development of PAH. As such, castration is necessary for all intact males because of the testosterone influence on the prostate and perianal musculature—without castration, PAH will recur.

During repair of the PAH, specific muscles of the pelvic diaphragm are sutured together to repair the defect. Frequently, the repair is re-enforced with a local muscle flap. Surgical mesh may be utilized in cases where there is not enough tissue to close the defect. In cases where the urinary bladder has slipped through the defect, an additional abdominal procedure may be needed to stabilize the bladder.

It has been shown that staging the surgery with an abdominal procedure first, which allows movement of the rectum and urinary bladder cranially (towards the head of the dog), followed by the actual hernia repair, improves overall success rates. This approach is preferred by certain surgeons. In the hands of an experienced surgeon, this technique is associated with a success rate of greater than 90 percent.

What is the post-operative care?

The surgical area, next to the rectum, and under the tail needs to be kept clean and dry. A course of antibiotics will be dispensed due to the contamination factor in surgeries performed near the rectum. Stool softeners, such as Metamucil or canned diet and a low residue diet are suggested for several weeks to try and prevent straining. The most common complications are reoccurrence of the hernia and infection of the surgical site.

Frequently Asked Questions

How long will my pet need to stay in the hospital?

Generally, pets will stay the night after the procedure and be discharged the following day.

Is castration necessary?

Yes. Perineal hernias are only found in intact males and castration will reduce the size of the prostate and remove the hormonal influence. Most veterinarians consider castration necessary, as the recurrence rate is much higher if the animal is not castrated.

What is considered an emergency?

Occasionally, the bladder can become stuck in the hernia, meaning the pet cannot urinate. Similarly, intestine can become entrapped in the hernia, leading to strangulation of the bowel. Either of these scenarios necessitates immediate veterinary attention.

Platelet Rich Plasma (PRP) Injection

Inflammatory and Healing Process:
Platelets play an important role in the body’s healing process beyond assisting the body’s clotting process. Platelets bring white blood cells to the area of injury to clean up remnants of dead or injured cells, and they release growth factors that are necessary for tissue regeneration. The inflammatory response is triggered after injury and prevents infection and debrides damaged tissue. Acute ligament ruptures lead to recruitment of various healing cells, including platelets. Unfortunately, tissue healing cannot take place until the inflammation subsides. Platelet Rich Plasma, or PRP, treatment was developed from the role that platelets play in both of these processes. Platelets release growth factors and proteins that assist with tissue healing. Therefore, PRP treatment has been promoted for tendon, ligaments, muscle, and joint injuries, which are known to be slow to heal.

Platelet Rich Plasma Therapy:
PRP facilitates the healing of bone, tendon, and ligament. It can also be used for treatment of osteoarthritis. This platelet-rich derivative of blood is obtained after a blood sample is withdrawn from a patient’s vein and separated from the other blood components after centrifugation with a specialized syringe. With this level of platelets, plasma has an abundance of the growth factors to help stimulate the healing process. When PRP is injected into damaged tendons or ligaments, it is believed that it stimulates cells in the tissue and recruits cells circulating in the blood to the injured site. Due to the use of the patient’s own blood for PRP, there is no risk of the treatment being rejected, as it might if the blood had been provided from a donor.

Sources:
-Franklin, Samuel P, MS, DVM, PhD, DACVS, DACVSMR . “Veterinarians Find Therapy Rich in Possibilities.” DVM360 Magazine (2014): n. pag. Web. 20 Aug. 2014. .

-Hakhamian, Ashkan, and Alan J. Schulman. “Platelet Rich Plasma: Its Place in Cranial Cruciate Ligament Repair.” Today’s Veterinary Practice (2012): n. page. Web. 20 Aug. 2014.

Portosystemic Shunt (PSS)

What is a portosystemic shunt?

Normally, the blood supply draining the intestines travels through the portal vein into the liver, where it is filtered, then returns to the heart via the caudal vena cava. A portosystemic shunt (PSS) is an abnormal vein connecting the blood supply returning from the intestines to the vein returning blood to the heart, bypassing the liver (shunting). Portosystemic shunts can be either congenital (present at birth) or acquired. Acquired PSS can develop in pets that have progressive liver dysfunction. Congenital PSS can be found within the liver (intrahepatic) or before the liver (extrahepatic). Intrahepatic shunts are more commonly found in large- breed dogs such as German Shepherds, Labrador Retrievers, Golden Retrievers, Irish Setters, Doberman Pinschers, and Irish Wolfhounds. Extrahepatic shunts are more commonly found in miniature- and toy-breed dogs, such as Yorkshire Terriers, Miniature Schnauzers, Poodles, Lhasa Apsos, and Pekingese, as well as cats.

What are the symptoms?

A patient with a portosystemic shunt (PSS) can show symptoms, such as poor weight gain, increased thirst and urination, increased salivation (more common in cats), vomiting, diarrhea, straining or difficulty urinating due to bladder stone development, and neurological symptoms, such as dementia, circling, blindness, and seizures. The animal may also be the “runt” of the litter. Occasionally, no symptoms are seen at all.

What is the diagnosis?

Diagnosis of a portosystemic shunt (PSS ) can be made from bloodwork, urinalysis, abdominal ultrasound, and other modalities, such as contrast enhanced X-Rays, computed tomography (CT) scan, MRI, and nuclear scintigraphy. Often, the definitive diagnosis will be made at the time of surgery.

What are the goals of surgery for extrahepatic portosystemic shunts?

Abdominal surgery is common and is considered the treatment of choice for extrahepatic portosystemic shunts (PSS). In surgery, the goal is to locate and place an ameroid constrictor around the blood vessel to allow gradual occlusion. An ameroid constrictor is a stainless-steel ring surrounding a casein center. Casein is a material that will gradually swell in the body fluids, allowing slow occlusion of the shunt. Gradual occlusion allows the liver to adapt to the increased blood flow. In rare instances, the PSS can be completely ligated (tied-off) at the time of surgery.

What are the goals of surgery for intrahepatic portosystemic shunts?

Although an intrahepatic shunt can be addressed as an abdominal surgery, the risks and complications during and after surgery are higher. Exposing these shunts may require dissection into the liver, and they tend to be larger, making it more difficult to occlude. Therefore, newer procedures have been developed to allow occlusion of the shunt through minimally invasive techniques, with the aid of catheters and interventional radiology. Most of these procedures are currently being performed at academic institutions, such as the University of Pennsylvania.

What is the surgical outcome?

Based on the current literature and professional experience, 85 percent of dogs with an extrahepatic portosystemic shunt will have an excellent outcome. About 10 percent of dogs will have a recurrence of signs and will require continued medical management. About 7 percent of dogs will have severe problems, such as seizures or other systemic problems, after surgery that may result in death.

What is the post-operative care?

Once your pet is home, it’s important to watch him or her for signs of complications, including abdominal swelling and more. Your surgeon will provide you with a complete list of signs to look for.

Subcutaneous Ureteral Bypass (SUB)

What is subcutaneous ureteral bypass?

The ureter is a tube that normally connects the kidney to the bladder. A subcutaneous ureteral bypass (SUB) device is designed to maintain the flow of urine from the kidney to the bladder when the ureter becomes obstructed. An obstruction can occur secondary to ureteral stones, trauma, strictures (scarring or narrowing), cancer, and sometimes infection (e.g. pyelonephritis). A SUB is placed surgically through the abdomen. Fluoroscopic imaging is used to guide placement.

The SUB device effectively bypasses an obstructed ureter. It consists of two tubes (also known as catheters) connected by a port. One catheter connects to the kidney and the other to the bladder. The port sits below the skin and allows urine to be sampled in a minimally invasive fashion. Urine flows through each catheter and, therefore, passes from the kidney to bladder bypassing the ureter.

Subcutaneous ureteral bypass vs. stent?

A urinary stent is a device that is placed within the lumen of the ureter (the tube between kidney and bladder). It is designed to both create a new “tunnel” and cause passive ureteral dilation allowing flow of urine from the kidney into the urinary bladder. Your veterinarian will help you decide what is best for your pet.

Is subcutaneous ureteral bypass placement urgent?

The most common indication for a subcutaneous ureteral bypass (SUB) is ureteral stones. When stones obstruct the ureter irreversible kidney damage can rapidly occur. In one study, after one week of obstruction, kidney function was reduced permanently by 35 percent. After two weeks of obstruction, kidney function was permanently reduced by 54 percent. Therefore, if indicated, placement of a SUB or ureteral stent is relatively urgent.

In 98 percent of cats and more than 50 percent of dogs, the ureteral stones are composed of calcium oxalate, which will not dissolve medically.

What is the advantage of a subcutaneous ureteral bypass over traditional surgery?

Subcutaneous ureteral bypass offers less potential risk of complications compared to ureteral surgery (such as ureterotomy and neoureterocystomy). It also can be performed much quicker than traditional surgery. This translates into benefits for the kidneys and the patient.

Is it permanent?

Yes, a subcutaneous ureteral bypass is a permanent device and is not typically removed.

What are the complications?

Like any surgical procedure, subcutaneous ureteral bypasses are not without potential complications. Some of these include procedural complications (e.g. urine leakage) as well as short- and long-term complications (such as dislodgement, obstruction, and recurrent urinary tract infection).

Tibial Plateau Leveling Osteotomy (TPLO)

What is a tibial plateau leveling osteotomy?

A tibial plateau leveling osteotomy (TPLO) is a method of repairing a cranial cruciate ligament (CCL) rupture in a dog. A CCL tear in the dog is similar to an ACL tear in humans. It can be an abrupt tear during trauma or strenuous activity, as often occurs in people. However, it can also be a slow deterioration of the ligament over weeks or months, potentially affecting both stifles (knees). Following a CCL tear, the limp is usually quite severe. While some improvement may occur with time, surgery is the best method of treatment for a dog with a CCL tear.

Over the past 30 years, numerous surgical techniques have been developed, of which the TPLO remains a very popular choice. The TPLO is usually the best option for large-breed dogs but is also a good option for moderate and small breeds, especially if a full return to an active lifestyle is desired. For the TPLO surgery, the angle of the tibia (the bone below the stifle) is changed so the ligament is no longer needed, unlike the human procedure where the ligament is repaired.

What is the post-operative care?

Strict rest is required following surgery to allow for proper healing of the tibia and the surrounding soft tissues. Initially, there should be no running, jumping, or playing. After the first month of strict rest, controlled activity may be gradually introduced for three months following surgery. Physical therapy is suggested to improve the speed of healing. In the weeks following surgery, X-Rays are taken to assess healing of the tibia.

What are the risks or complications?

Most complications following tibial plateau leveling osteotomy are minor in nature. With some minor complications, additional medications or other forms of physical therapy may be required. Major complications, those requiring additional surgery, are not very common. As long as the activity restrictions are adhered to, it is not likely that additional surgery will be needed.

Can the leg be re-injured following surgery?

After the healing is complete, it is rare for problems to develop. In fact, tibial plateau leveling osteotomy is occasionally performed when other methods of repair have failed to return dogs to good use of their leg(s).

Tibial Tuberosity Advancement (TTA)

What is tibial tuberosity advancement?

Tibial tuberosity advancement (TTA) is a recently developed surgical treatment for cranial cruciate ligament (CCL) injuries. The biomechanical rationale of TTA is that a forward shift in the position of the tibial tuberosity counteracts the instability created within the stifle following a CCL tear. The tibial tuberosity is secured with specially designed implants so that the patellar ligament is perpendicular to the tibial plateau.

The long term prognosis for excellent limb use following TTA is comparable to tibial plateau leveling osteotomy, or TPLO. Both TTA and TPLO are generally preferred over previously developed techniques, especially in medium- and large-breed dogs. One advantage of TTA over TPLO is that it is less invasive, as there is less soft tissue dissection during surgery and the bone is cut in a portion that does not bear the body’s weight. This results in less swelling and pain following surgery. Additionally, while the total activity restriction following TTA is similar to TPLO, the lameness resolves more rapidly following TTA. Lastly, TTA implants are made from titanium, which offers superior biocompatibility.

What is the aftercare?

Strict rest is required following surgery to allow for proper healing of the tibia. Initially, there should be no running, jumping, or playing. After the first month of strict rest, controlled activity may be gradually introduced for three months following surgery. Physical therapy is suggested to improve the speed of healing. In the weeks following surgery, X-Rays are taken to assess healing of the tibia.

What are the common risks or complications?

Post-operative complications following tibial tuberosity advancement surgery are similar to that of the tibial plateau leveling osteotomy surgery. The overall complication rate is low. Most minor complications are easily treated or self-resolving, and major complications requiring additional surgery are rare and usually appear after inadequate confinement or trauma.

Can the leg be re-injured following surgery?

After the healing is complete, it is rare for problems to develop. In fact, tibial tuberosity advancement surgery is occasionally performed when other methods of repair have failed to return dogs to normal use of the leg(s).

Total Ear Canal Ablation (TECA)

What is a total ear canal ablation?

The ear is comprised of inner, middle, and external portions. The inner ear is responsible for balance and the connection of sound waves to the brain. The middle ear contains the tympanic bulla and ear drum. The external portions contain the ear canal and the pinna. A total ear canal ablation is the surgical removal of the entire ear canal. A second procedure, called a bulla osteotomy, is performed during the same surgery. By opening and clearing the bulla of all infected material combined with the ear canal removal, the chances of future infection are greatly decreased.

Why is the surgery performed?

Ear canal removal is most commonly performed in Spaniel breeds, in which chronic ear infections often occur. Chronic ear pain may lead to lethargy, inappetance, and frequent scratching at the ear. Once medical therapy is no longer effective in controlling ear canal infections, surgical removal of the entire ear canal is indicated to eliminate the pain and bad odor that is associated with this condition. Total ear canal ablation is the treatment of choice in most cases of cancer within the external ear canal. Depending on the aggressiveness of the tumor, removing the ear canal along with the tumor can be curative.

What will the ear look like after surgery?

The cosmetic result following surgery is excellent. Once the incision heals and the hair regrows, it is very difficult to notice that surgery has been performed. Other than the absence of the ear canal, all other structures of the ear are left undisturbed.

What is the post-operative care?

Most pets recover quickly following ear canal removal. Strict rest is advised for two weeks to ensure incision healing but most patients seem eager to return to full activity long before this period of rest is complete.

Are there any risks or complications?

The sense of hearing will be decreased following surgery; however, many owners do not notice a significant change. Patients typically have a history of diminished hearing prior to surgery due to chronic inflammation and thickening of the ear canal. Temporary damage to the facial nerve may occur during surgery, which leads to a loss of the blink reflex for two to four weeks, so eye lubrication is required to moisten and protect the eye. Permanent facial nerve damage is possible but rare. Infection and/or abscess formation may occur up to two years after surgery; the risk of this occurring is 5 to10 percent. Other less common complications include signs of inner ear disease (circling, head tilt, abnormal eye movement) and difficulty eating due to jaw pain. Most of these complications resolve with time and rest.

Tracheal Collapse and Intraluminal Stents

What is tracheal collapse?

A dog’s trachea is constructed of 30 to 40 C-shaped cartilage rings that are connected by ligamentous tissue. Tracheal collapse is a progressive, degenerative disease that causes the tracheal rings to lose their C configuration. The cartilage of the tracheal rings in patients with collapse has fewer cells with less calcium and chondroitin sulfate compared to normal cartilage. As degeneration continues there will be progressive flattening of the tracheal rings, causing narrowing of the tracheal diameter. This narrowing is graded from 1-4, with grade 4 being the worst.

How is tracheal collapse diagnosed?

The diagnosis of tracheal collapse is based on the patient’s history, X-Rays, fluoroscopy, or tracheoscopy. Breeds most commonly affected by tracheal collapse include Yorkshire Terriers, Pomeranians, and brachycephalic breeds, such as Shih Tzus and Pugs. The patient will present with a history of coughing, which may be characterized as a “goose honk.” The cough will occur when the patient is excited or under heavy activity, although in some extreme cases the cough will be constant. X-Rays can show the narrowed trachea and confirm diagnosis of tracheal collapse. Fluoroscopy is necessary on an awake patient to visualize the length of the trachea affected when coughing is induced. The trachea can narrow or collapse in the neck, chest, or both. It is critical to rule out other diseases that can mimic tracheal collapse, such as laryngeal paralysis, laryngeal collapse, severe heart disease, or lower airway (bronchi, lungs) disease.

What treatments are available?

Early in the disease process, many of the patients can be managed medically with anti- inflammatory drugs, cough suppressants, sedatives, or bronchodilators. As the disease progresses, some patients may no longer respond favorably to medical therapy or may have concurrent disease that exacerbates the tracheal collapse (chronic bronchitis, heart disease, brachycephalic airway, etc).

Intraluminal stenting for tracheal collapse has shown favorable results, with 76 to 90 percent improvement. Placement of the stents requires general anesthesia with the aid of fluoroscopy. Measurement for the appropriate size stent is taken from X-Rays or the fluoroscopic image. The patient would require a second anesthesia to place the stent. The majority of cases show immediate improvement in clinical signs. Complications may include dry cough, stent shortening, intraluminal scar tissue formation, and stent fracture.

Surgery is a viable option for patients that have failed medical management. Several techniques have been described but the most widely accepted surgical management of tracheal collapse in the neck remains polypropylene rings placed around the trachea, suturing the trachea to the prosthesis. Overall, the success with this procedure is reported to be 75 to 85 percent, with reported complications including persistent cough, laryngeal paralysis, patients requiring tracheostomies, and intra-operative death. This technique is not a viable option for treatment of tracheal collapse within the chest due to an excessively high morbidity rate.

Upper Airway Surgery

The upper airway of dogs and cats comprises the passages that air moves through on its way to the trachea (windpipe) and lungs. These passages include the nose, sinuses, pharynx, and larynx. There are many different problems that can affect the upper airway and compromise the flow of air. Brachycephalic dogs and cats are more prone to upper airway abnormalities and can often have several different conditions together. A brachycephalic breed is one that has a shortened snout and face, such as English Bulldogs, Pugs, Boston Terriers, and Persians. The conditions most often found in these breeds are stenotic nares, everted laryngeal saccules, and elongated soft palate. When these conditions compromise respiration, surgical intervention is necessary.

What are the symptoms?

The symptoms of brachycephalic airway syndrome can include the following:

• Noisy breathing
• Excessive snoring
• Open mouth breathing
• Gagging and/or choking
• Exercise intolerance
• Cyanosis (blue tongue)

These symptoms are exacerbated by hot and humid weather. Obesity is also a contributing factor in the worsening of symptoms.

A concrete diagnosis is made by visual examination of the upper airway. These laryngeal examinations most often are performed with the help of sedation or general anesthesia.

Which conditions necessitate this surgery?

Stenotic nares is the medical diagnosis for nostrils that are too closed to allow normal respiration. These animals tend to excessively breathe through their mouths and wheeze when they try to breathe with their mouths closed. The treatment for this condition is a rhinoplasty (nose job). A small wedge of tissue is resected from the side of the nostril and the edges are sutured together to widen the nostrils and allow for normal respiration.

Everted laryngeal saccules occur in dogs that have compromised upper airway flow. These dogs must work harder to fill their lungs with air, which results in the laryngeal saccules being pulled down into the airway. The laryngeal saccules are small bags of tissue that are positioned in front of the vocal cords. When they are pulled into the airway, they block the opening to the trachea. The treatment for this problem is to remove the saccule tissue.

Elongated soft palates can vary from slight to severe. The condition occurs when the soft palate is too long, and, if slight, the clinical signs usually consist of snoring. If the soft palate is long enough to hang down into the airway, it can block the opening to the trachea and prevent normal airflow. This is a very serious condition and can sometimes result in a complete obstruction of airflow. The treatment for this condition is to excise the excess tissue in order to shorten the soft palate.

What is the post-operative care?

The post-operative care depends on which procedure, or combination of procedures, were performed. Patients that have only had a stenotic nares repair can often go home the same day. They must wear an Elizabethan collar at all times to prevent them from rubbing or scratching at the sutures in their nose. If everted laryngeal saccules or a soft palate were excised, the patient must spend at least one night in the hospital. These surgical procedures can cause inflammation in the throat, which requires supervision. Once home, patients must remain on a soft diet for a minimum of two weeks. They must be kept quiet and cool to allow their airways to heal and reduce inflammation.

What are the possible complications?

The complications involved in upper airway surgery depend on the severity of the patient’s condition. In some cases, additional surgery may be required to resect more tissue if clinical signs persist post operatively. In very severe cases where a patient has been greatly compromised by their condition, intensive care may be necessary post operatively, including a temporary tracheostomy to allow the upper airway to heal.

Ureteral Stent

What is a ureteral stent?

The ureter is a hollow tube that is designed to transport urine from the kidney to the bladder. An obstruction of the ureter can occur for various reasons. These may include but are not limited to ureteral stones, trauma, strictures (scarring or narrowing), cancer, and sometimes infection (e.g. pyelonephritis).

A ureteral stent is a device designed to maintain the flow of urine from the kidney to the bladder when the ureter becomes obstructed.

It is placed within (inside) the ureter to act as a conduit for urine flow. It is typically a double-pigtail design, meaning that the ends are curled to prevent movement from the kidney or bladder. Typically, urine flows through the middle of the stent and around the stent as the ureter passively dilates. An alternative option to a stent is a device known as a subcutaneous ureteral bypass, or SUB.

Subcutaneous ureteral bypass vs. stent?

Your veterinarian will help you decide what is best for your pet.

Is stent placement urgent?

The most common indication for stent placement is ureteral stones. When stones obstruct the ureter (the tube between kidney and bladder) irreversible kidney damage can rapidly occur. In one study, after one week of obstruction, kidney function was reduced permanently by 35 percent. After two weeks of obstruction, kidney function was permanently reduced by 54 percent. Therefore, if indicated, placement of a stent or subcutaneous ureteral bypass, or SUB, is relatively urgent.

In 98 percent of cats and over 50 percent of dogs, the ureteral stones are composed of calcium oxalate, which will not dissolve medically.

What is the advantage of a stent over traditional surgery?

Stenting offers less potential risk of complications compared to traditional ureteral surgery. It also can be performed faster than traditional surgical techniques and, in female dogs, can sometimes be performed endoscopically. This is better for the patient—especially the patient’s kidneys.

How is it placed?

A ureteral stent can be placed surgically or endoscopically. Fluoroscopic imaging is used to guide placement. Endoscopic placement is typically much more difficult to perform in males and small patients due to the size of the urethra.

Is it permanent?

Unlike in humans, a ureteral stent is often left permanently in pets. However, in some cases the stent needs to be exchanged or removed.

What are the complications of stents?

Like any procedure, ureteral stents are not without potential complications. Some of these include procedural complications (eg. ureteral tears) and peri-operative and short- and long- term complications (such as painful or frequent urination, stent migration and re-obstruction of the ureter). Another alternative for your pet may be subcutaneous ureteral bypass, or SUB.

Urethrostomy

What is a urethrostomy?

A urethrostomy is a surgical procedure to create an opening in the urethra, the tube through which urine flows from the bladder and is voided. The surgery is performed to correct a urethral obstruction, which can be caused by protein plugs, stones, trauma, or scarring (stricture). A urethral obstruction is a serious, life-threatening condition; therefore, urethtrostomies are often performed on an emergency basis. In male cats, a perineal urethrostomy, or PU, is performed, and in dogs a scrotal urethrostomy is performed.

What are the indications for performing a urethrostomy?

A urethrostomy is indicated when the urethral opening is persistently obstructed or is too narrow. It is most commonly performed on male cats that suffer from feline urologic syndrome, a condition that makes them prone to protein plugs, bladder “sand” or “sludge,” or bladder stones that enter the urethra and obstruct the flow of urine. Some cats with this condition will respond to medication and/or a special diet, but surgery is the best treatment for those who have recurrent episodes of obstruction. In dogs, a urethrostomy is indicated when bladder stones have traveled to the urethra and caused a partial or complete obstruction to the flow of urine. The breeds most commonly affected by this condition are Dalmatians and Lhasa Apsos. In both cats and dogs, a urethrostomy would be performed in cases of severe penile trauma or scarring/stricture that does not allow for the normal passage of urine.

What is the difference between perineal and scrotal urethrostomy?

The difference between these two procedures is where the opening in the urethra is made. A perineal urethrostomy creates an opening in the perineum, or the space between the rectum and scrotum. The penis is completely excised and the urethral opening is made larger to allow urine, stones, and sand to pass. A scrotal urethrostomy creates an opening directly in front of the scrotum (intact males must be castrated at the same time). The penis is left intact, and most often the dogs will continue to exhibit the same voiding behavior, such as lifting their leg, even though the urine is voided from a different area.

What is the post-operative care?

Patients that have had a urethrostomy must be kept calm and inactive during their recovery. Often times, they will bleed from the surgical site for up to 10 days post operatively. Keeping them calm may help in reducing the amount of bleeding. Cats should have constant access to a litter box, as they will feel an increased urgency to urinate. The litter should be dust/clay free; for example, there are several brands of litter that make pellets from old newspaper. Dogs may also feel an increased urgency to urinate and be walked more often. Any patient that has had a urethrostomy performed must wear an Elizabethan collar at all times until suture removal.

What are the risks and complications?

The overall risk involved for a healthy patient is low. The risk can be increased by compromised renal function compounded by general anesthesia. Other risks are hemorrhage, post-operative infection, and wound dehiscence (breakdown). Scar formation can occur in some cats, causing a stricture of the urethra, which requires additional surgery.

Vascular Access Ports

What is a vascular access port?

Vascular access ports (VAPs) are medical implant devices occasionally recommended for patients that are undergoing long-term medical treatment or that require frequent blood tests for monitoring of chronic conditions.

Routinely used in human medicine, a VAP is implanted under the skin during a brief, out- patient surgical procedure through a small incision. The main advantage of port placement is that it provides your veterinarian access to administer intravenous medications or draw blood without the need for repeated and potentially painful puncture of the veins. The port is a sterile, semi-permanent device created from biocompatible materials, and includes a catheter placed into a vein (often the jugular or femoral vein), connected to a metal hub with a silicone membrane that is designed for repeated puncture by a specific (Huber-type) needle.

What are the indications for port placement?

• Chemotherapy
• Sedation for radiation treatments
• Long-term medication administration
• IV fluid therapy
• Anti-seizure medications
• Monitoring blood values
• Blood donor access

What is the post-operative care?

Incisional healing typically takes place within one to two weeks after the procedure. A small bump may be felt under the skin at the location of the port, but no portion of the device will be exposed. The most frequent complications associated with the procedure are minor and include obstruction of the catheter or migration of the port over time, which may require adjustment or replacement.

Degenerative Joint Disease (DJD)

What is degenerative joint disease?

Degenerative joint disease (DJD) is more commonly known as arthritis. This is a progressive, non-infectious condition of the weight-bearing joints. Normal, healthy joint cartilage is smooth, white, and translucent. It consists of cartilage cells, protein, water, and collagen that form a sponge-like middle. In the early stages of arthritis, the cartilage becomes yellow and opaque and softens to create a rough joint surface. As the disease progresses, the soft areas become worn and expose the hard bone underneath, causing remodeling. This progression leads to osteophytes (bone spurs) in the joint and a decreased blood supply that inhibits cartilage repair. DJD can be caused by aging changes in a joint or by a mechanical instability. Mechanical instabilities are most often the result of joint abnormalities (such as hip or elbow dysplasia), trauma, or wear from a ruptured anterior cruciate ligament, luxating patella, or osteochondritis dissecans.

What are the symptoms of degenerative joint disease?

Most often, the clinical signs of degenerative joint disease (DJD) appear in middle-aged and geriatric patients. They can include stiffness, reluctance to go on walks, and trouble with stairs. As the condition progresses, these symptoms become more severe, sometimes to the extent that the animal will not use the affected limb. Symptoms of DJD are exacerbated by cold, damp weather.

How is degenerative joint disease diagnosed?

Degenerative joint disease (DJD) is diagnosed through a physical examination and X-Rays. Early DJD may only show a decreased joint space, as cartilage is not radio-opaque. Mid- to severe-stage DJD can be seen in the formation of osteophytes and changes in the bone under the cartilage.

How is degenerative joint disease treated?

Treatment of degenerative joint disease is limited to medicinal and physical therapy to reduce the amount of pain in the surrounding ligaments and joint capsule. After routine bloodwork is performed, the patient may be placed on a non-steroidal anti-inflammatory (NSAID) and, in the case of obese dogs, may be put on a prescription weight-loss diet. Corticosteroids may be used in severe cases that do not respond to NSAIDs. The ideal physical therapy for dogs is swimming or the use of an underwater treadmill. Other physical therapy exercises include short walks and passive flexion and extension of the affected joint. Additional treatment options include the use of supplements, such as glucosamine and chondroitin, acupuncture, and electrical pulse therapy.