Renal Transplantation in Cats - Information for Veterinarians
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Article Written by Dr. Daniel A. Degner, Board-certified Veterinary Surgeon (DACVS)

Key Points

Chronic renal failure in cats usually is progressive and irreversible

Renal transplantation is a viable option to control renal failure

Transplantation improves the quality of life of the cat dramatically

Introduction

Chronic renal failure (CRF) in cats is a progressive, irreversible condition which usually leads to death as a result of uremia months to years after initial diagnosis. Overall, approximately 2% of all cats will be diagnosed with CRF at some point in their life. Chronic renal failure is a very common disease in cats, especially older cats. Recent reports indicate that approximately 10-30% of cats 10-15 years of age and 32% of cats greater than 15 years of age are diagnosed with chronic renal failure. Therefore, this represents a very common disease entity in cats. Cats with mild to moderate CRF may be managed medically with dietary and other forms of symptomatic medical management. However, such forms of therapy are largely ineffective in cats with advanced CRF. Renal transplantation has proven to be a successful alternative form of treatment.

Cats do not have as great a problem with allograft rejection as do dogs when treated with immunosuppressive drugs such as cyclosporine and prednisone. The major histocompatibility complex on feline red cells is similar to those found on endothelial cells of the kidney. As a result, only cross-matching is required for donor recipient compatibility. Using this type of donor recipient matching, hyper-acute and acute rejection of renal grafts rarely occur. Failure of renal grafts in cats usually is due to chronic vascular disease, which results in gradual occlusion of the arterial supply of the graft. This may take a number of years to develop.1-4


Definition of Chronic Renal Failure

Cats in chronic renal failure have BUN and creatinine levels that are above normal range, specific gravity less than 1.035.  Isothenuria is common, however, be aware that specific gravity is not always a clear indicator of renal insufficiency in cats as it is in dogs and humans.  The presence of clinical signs which suggest chronic renal disease include weight loss, anemia and small to normal kidney size.


 

Candidates for Renal Transplantation must be preferably free of underlying diseases. 

Cardiomyopathy, if present, should not be severe.  Mild to moderate hypertrophic changes may result from increased afterload caused by renal-induced hypertension. Hypertension is common in cats that have renal failure due to an imbalance of the angiotension system.  Hypertension could lead to seizures, retinal detachment and other significant problems in the postop period.  Hypertension should be under control with medication prior to surgery; frequently cats will become normotensive following renal transplantation.  If this does not occur, removal of the diseased native kidneys should be considered.  Diabetes mellitus is not an absolute contraindication for renal transplantation, however, can lead to other complications such as urinary tract infection.  Hyperthyroidism can affect multiple body systems, including heart, blood pressure, renal function and body metabolism, therefore should be under control with medication prior to transplantation; after transplantation has been completed and the cat is stable, I131 therapy should be considered.  Nephrolithiasis is not an absolute contraindication for transplantation, however, may increase the risk for urinary tract infection or development of stones in the graft, especially if the cause of the stones is extra-renal.  In summary, cats should be preferably free of the aforementioned diseases, however, under the care of an diligent owner and internist, other coexisting diseases can be dealt with in the renal transplant patient.


Candidates MUST be free of a number of diseases. 

Infections such as chronic recurrent upper respiratory viral infection, Feline Leukemia Virus infection, Feline Immunodeficiency Virus infection, Hemobartonella, Toxoplasma, and urinary tract infection to name a few, are contraindications for renal transplantation.  Urinary tract infection or previous history of recurrent UTI is a strong indication to be rejected from a renal transplantation program, as these cats develop UTI very readily when immunosuppressed with cyclosporine, which may lead to pyelonephritis and graft dysfunction.  Inflammatory bowel disease  has a high risk for kidney rejection due to hyperimmunity.  No neoplastic or preneoplastic process can be present at all; cyclosporine immunosuppression will result in the cancer going rampant.  Renal amyloidosis is contraindicated as amyloidosis of graft will occur.  Likewise glomerulonephritis is a systemic disease which will destroy the graft.


Notes about co-existing conditions

The presence of co-existing does not necessarily preclude a cat from being a suitable transplant candidate. A cat that has had a previous upper respiratory viral infection or a past history or urinary tract infection can be challenged with cyclosporine (with trough blood levels greater than 500ng/ml) for three weeks; if the cat breaks with an infection, it is a poor candidate for transplantation.  Cats that have chronic recurrent urinary tract infection are generally not acceptable candidates for transplantation.  If a cat develops recurrent urinary tract infections after receiving a renal graft, life-long antibiotic therapy likely will be needed.

Recipients should be preferably in an early decompensated state of renal failure. Recipient cats that have not lost more than 20-30% of body weight are better candidates, as loss of a significant amount of weight may coincide with multi-organ disease. We have transplanted patients that had lost about 30 to 40% body weight and they have done well.  Anesthetic and surgical risks are increased in these patients.


Recipient Preoperative Workup

The recipient cat should be blood typed as the first step; the recipient should be type A. If the recipient does not have type A blood, transplantation is not advisable as an acceptable donor will be difficult, if not impossible to identify.  Other tests that should be done include major and minor RBC cross-match, complete blood cell count, chemistry, urinalysis, T4, Urine culture (collected by cystocentesis only; do not start antibiotics prior to urine culture), FeLV/FIV tests, Hemobartonella (RIA) test, Bartonella, Toxoplasma titers, echocardiogram, thoracic and abdominal radiographs, renal ultrasound, fundic examination (to evaluate for hypertension), doppler blood pressure (do repeated evaluations under unstressed conditions).  All blood and urine testing should be done by a reputable veterinary blood laboratory and not by in-house machines.


Recipient Preparation for Surgery

Prior to surgery the renal transplant candidate should be in as good nutrition as possible.  A good plane of nutrition should be established.  Placement of a PEG tube or esophagostomy tube may be important to provide adequate food intake prior to surgery (we routinely place PEG tubes at the time of transplant surgery, if it is not already in place).  Anemia should be corrected to at least a PCV of 30%.  Erythropoietin 100 U/kg sub-Q three times per week may be administered. An alternative dosage is 100 U/kg daily for the first five days, then a reduced frequency of administration to three times per week. It is important to monitor the PCV closely while using this drug. Poor response or worsening of the anemia suggests that the patient is producing antibodies against the erythropoietin, necessitating discontinuation of the medication.  Supplementation with vitamin B complex and iron may also help these patients.  Blood transfusions, if needed, should be given 2-3 days prior to surgery; cross-matching is essential.  Fluid therapy should be administered to decrease azotemia.  Correction of electrolyte and acid/base balance should be done prior to anesthesia.  Immunosuppressive therapy should be started two days prior to surgery using Cyclosporine 2 to 5 mg/kg BID PO (put in gel cap - bitter tasting) and Prednisolone 0.25 mg/kg BID PO, starting the day of surgery.


Kidney Donors

Blood type of a kidney donor must be same as recipient.  A donor must be adult, healthy, large (10 pounds), young cat (1-5 years of age), free of FeLV/FIV, urinary tract infection, toxoplasmosis, and major organ disease.  Renal function must be normal.  The graft must have normal renal architecture on ultrasound imaging. The renal graft must have a single renal artery, as the arterial renal blood supply is segmental. If a kidney has two arteries, ligation of one of these vessels will result in necrosis of a portion of the kidney. In addition, the diameter of each renal artery is usually too small to microsurgically anastomose to the aorta (a typical renal artery is 1.5 mm in diameter). If double renal veins are present, the smaller is ligated and the larger of the two is anastomosed to the cava, as the renal venous drainage system is not segmental. 


Compatibility of Donor with Recipient

The major histocompatibility complex antigens found on feline red blood cells are homologous to those found on the vascular endothelium of the kidneys; therefore, tissue typing has not been traditionally used to identify a suitable donor. To determine compatibility of the donor with the recipient, a major and minor red blood cell cross match is performed. If the cross-matches are compatible, acute rejection is unlikely. In the rare situation, a cat will not cross match with any donor (due to the presence of idiotypic antibodies).  Additional testing such as mixed lymphocyte reaction test can be used to further define compatibility of the donor graft, but is generally not needed.


Donor Preoperative Workup

Blood type and RBC cross match with recipient should be done prior to any further testing; if the donor is a match, additional testing can be done.  Additional testing includes CBC, chemistry, urinalysis, urine culture, FeLV/FIV, Hemobartonella test, renal ultrasound, and abdominal radiographs.  All blood and urine testing should be done by a reputable veterinary laboratory and not by in-house machines.

Owners are to provide a kidney donor. Euthanasia of any kidney donor is strictly in violation of our transplant team’s policy.


Surgery

Donor. Exploratory laparotomy is performed on the donor cat to ascertain that a single-renal artery renal graft is present (photo to the right). Once a single renal artery-graft has been identified, the recipient cat is anesthetized. Twenty minutes prior to removal of the kidney, Mannitol 0.5 g/kg IV, is administered to decrease warm ischemia injury to the kidney. In the photo right, the renal artery is very small in diameter due to vasospasm, which is minimized with topical lidocaine. 

Details of renal graft harvest.  The left kidney is the preferred graft, as it has longer renal vessels, but the right kidney can also be used. The peritoneum is incised around the entire circumference of the kidney.  Using blunt finger dissection, the kidney is liberated from the retroperitoneal fat.  The kidney is reflected ventrally; during the entire dissection process, the kidney is handled very gently - minimal pressure.  During the dissection, the renal vessels are frequently irrigated with 2% lidocaine to minimize vasospasm (which could contribute to warm ischemia time). The renal artery is exposed on the craniodorsal aspect of the vascular pedicle.  The gonadal artery and vein are ligated using fine suture or hemoclips.  The fat is cleared from the renal artery and vein taking care to preserve the ureteral artery and vein, which extend off of the parent vessels at the level of the hilus of the kidney.   The phrenicoabdominal vein originates at the base of the renal vein and should be preserved.  The adventitial is dissected off the renal artery and vein at the proposed region of transection (near the aorta and vena cava).  

 

The ureter is identified (photo right - finger pointing to ureter) by the ureteral vein and artery, which usually can be seen in the periureteral cuff of fat.  The ureter is isolated from the level of the kidney to the bladder.  A small arterial or venous peritoneal vessel, which anastomoses with the mid section of the ureteral vessels, is ligated and divided.  Once the dissection has been completed, the abdomen of the donor is covered with with moistened laparotomy sponges and the recipient cat is prepared to receive the graft. 

 

 

 

 

After the aorta and vena cava of the recipient cat have been prepared, the donor graft is completely harvested.  The ureter is ligated at the level of the bladder and transected cranial to the ligature.  Hemoclips or suture ligatures are applied to the origins of the renal artery and vein.  Microvascular clamps are applied to the mid-section of the renal vessels and the vessels are transected using very sharp, fine iris scissors or straight microdissecting scissors.  The vessel ends are irrigated with saline to flush out any blood.  Some surgeons flush the entire kidney with heparinized chilled saline or preservation solution, but this is not needed if the warm ischemia time is minimized to less than one hour. 

 

 

 

 

 


Recipient.  The primary surgeon should sit on the right side of the operating table.  A 3 cm section of abdominal vena cava caudal to the right renal vein is isolated using a combination of sharp and blunt dissection.  The caudal extent of caval dissection is usually limited by a very large dorsal branch that penetrates the hypaxial muscles (see photo - caudal is to your left).  A ¼" Penrose drain is placed around the isolated vena cava to retract the vessel from the aorta (photo right). A section of the aorta is likewise isolated.  A dorsal branch extending off the aorta in this region also is present and can be preserved by temporary occlusion with a small microvascular clamp.   

 

 

 

 

A 3/4" Penrose drain is placed beneath both the aorta and vena cava and the adventitia is cleared from the proposed sites of the arteriotomy and venotomy.  The adventitia is cleared from a site that is twice the diameter of the proposed arteriotomy/venotomy dimensions.  Only redundant adventitia should be excised from the cava, as excessive trimming of tissue could potentially thin the wall too much.  With the use of the sutureless technique, minimal adventitial needs to be excised as the edges of the vessels are everted during the anastomosis.

 

 

 

 

 

The Penrose drain is released from the vena cava, and is only placed beneath the aorta, as the arterial anastomosis is performed first.  Care must be taken to ensure that the aorta is not not twisted as the Penrose drain is passed beneath the vessel.  The Penrose drain is clamped under tension to the drapes on the left and right sides of the cat as this will elevate the aorta to the surface of the incision and will simplify the anastomosis (versus working in a deep hole).  Single clamps are applied cranially and caudally to the proposed arteriotomy site, to compresses the vessel in a dorsoventral direction. I have found that application of a Satinsky vascular clamp in a mediolateral direction (which some surgeons use) makes the anastomosis more difficult to perform, as it collapses medial and lateral walls of the arteriotomy site together.

 

 

 

 

Arteriotomy.  A 1.2 mm Acland arteriotomy clamp is applied to the ventral most aspect of the aorta.  Only a very small section (see photo right) of aorta is grasped with the clamp (to the top of the hole in the arteriotomy clamp).  The arteriotomy is made as small as possible as it usually ends up being larger than expected.  A Dennis blade is used to cut the hole in the side of the aorta. 

 

 

 

 

 

 

After the arteriotomy has been completed, blood is flushed from the lumen of the aorta. 

 

 

 

 

 

 

 

 

End-to-side anastomosis of the renal artery to the abdominal aorta using a simple interrupted pattern with 10-0 Nylon on a 75 micron needle is performed. The renal artery is placed in close proximity to the aortic arteriotomy site.  The kidney (left graft) is positioned such that the ventral aspect of the kidney faces the right side of the abdomen with the renal vein positioned to the right and the artery to the left.  Thus the vessels correspond with the vena cava (right) and aorta (left).

 

 

 

 

 

 

 

Atraumatic handling of the vessels is essential during suturing.  The vessel wall is not directly grasped with Jeweler's forceps, rather the vessel is lifted with the tips of the instrument.  Additionally, the vessel can be handled safely by grasping the adventitia with Jeweler's forceps.

 

 

 

 

 

 

 

An interrupted suture pattern is less traumatic to the somewhat friable renal artery versus a continuous pattern; the suture holes tend to enlarge using a continuous pattern.  The advantage of a continuous pattern pattern is that it decreases the ischemia time. 

 

 

 

 

 

 

 

The end-to-side venous anastomosis is preformed using either a suture or sutureless anastomotic technique.  I prefer to use the microvascular anastomotic device to perform the venous anastomosis, as it is a rapid and easy method.  There is much less chance of making a technical error such as suturing the front and back walls of the vessel together and inverting the adventitial side of the vessel into the anastomosis.  Both of these errors lead to thrombosis of the vessel.  The sutureless anastomosis is performed using the two polyethylene rings, each of which have six pins on one side of the ring (see photo to right).

 

 

 

 

 

 

 

The first step of the sutureless technique is to measure the outer diameter of the renal vein with the measuring gauge. Most renal veins require a 2.0 mm coupling device, although some the 2.5 mm device is sometimes needed.  A 3/4" Penrose drain is passed around the vena cava (and aorta) to expose the proposed venotomy site.  Approximating clamps are applied to the vena cava and the clamps are moved about 7 mm together in order to take tension off the portion of cava that will be anastomosed (Permission granted to use this illustration courtesy of Mr. Mike Campbell 2000).

 

 

 

 

 

 

 

Using a Pierce forceps, the renal vein is pulled through the lumen of the plastic ring.  Only the very edge of the vessel wall that will be everted is grasped with the forceps.  The wall of the vessel is impaled on the pins of the ring, thus inverting the wall of the vessel.  A transverse venotomy incision is made in the vena cava using a Dennis blade and adventitial scissors.  The edges of the venotomy incision are pulled through the lumen of the opposite plastic ring and impaled on the pins of the ring.  The two rings are mated together using the anastomotic instrument, which holds the plastic rings. (Permission granted to use this illustration courtesy of Mr. Mike Campbell 2000).

 

 

 

 

 

The clamps are released from the renal vein, then the vena cava.  Next the clamp is released from the renal artery, and then the aorta.  If adequate numbers of sutures have been placed, minimal bleeding from the arterial anastomosis and no bleeding from the vein occurs.  If some bleeding occurs from the arterial anastomosis, moistened gauze sponges are placed around the vessels for about five minutes, then slowly removed.  Patency of the anastomoses is evaluated by observing pulsations in the artery and filling of superficial vessels on the surface of the kidney.  Flow across the venous anastomosis is noted by some degree of whorling of blood from the renal vein in the vena cava.

 

 

 

 

In order to prevent torsion of the vascular pedicle in the postop period, a ventrally based transversus abdominis muscle flap is sutured to the kidney using four interrupted sutures of 4-0 PDS.  Neoureterocystostomy is performed to complete the surgery.

 

 

 

 

 

 

 

 

 

 


Postoperative Medications

1.  Cyclosporine 2-5 mg/kg BID PO (put in gel cap - bitter tasting) initially.

Please note that once a cyclosporine bottle has been opened, it expires after two months. Exposure to air oxidizes the medication and renders it inactive. To extend the life of a 50 ml bottle of cyclosporine, fill 10 ml or 25 ml amber glass bottles to the top, seal and use later. The microemulsion form of cyclosporine (Neoral) is more readily absorbed from the GI tract than the regular form of the cyclosporine (hence the cost to the owner may be reduced). Flavoring the medication has been tried (liver flavor etc), however, in my experience it alters bioavailability of the drug and blood levels drop.

The bioavailability of cyclosporine varies from cat to cat, therefore, whole blood cyclosporine levels must be measured. The oral dose of the drug is adjusted to maintain blood levels around 500ng/ml during the first month, then 250 ng/ml for the life of the patient. It is common that the initial cyclosporine blood level will be 1500 to 3000 ng/ml when the cat receives the 5 mg/kg dose. As the liver begins metabolizing the drug, the blood levels will drop quickly without adjusting the oral dose. Be aware that the cyclosporine blood levels do not have a linear relationship with the oral dose. For example, if the blood level is 1000 ng/ml and the oral dose is 20 mg, a reduction of the oral dose to 10 mg will not result in a level of 500 ng/ml, rather the blood level likely will be 100 ng/ml. It is therefore advisable to reduce oral cyclosporine doses by 2 to 4 mg increments, depending on the cyclosporine level. In humans, the dose is reduced in 5% increments. ALWAYS CONSULT WITH A MEMBER OF THE TRANSPLANT TEAM PRIOR TO ADJUSTING THE DOSE OF THE CYCLOSPORIN.

The veterinarian caring for a cat that has been transplanted should always have the injectable (IV) form of cyclosporine in their hospital.  If a recipient cat becomes ill for any reason...gastroenteritis, pancreatitis, or whatever disease that causes vomiting or stasis of the GI tract and the cat cannot keep the oral cyclosporine down, blood cyclosporine levels may drop to a level that could cause graft rejection.  A very transient episode of illness for about 24 hours is likely not going to cause a problem, but beyond that point will cause a problem.

In these cases, one third of the usual oral dose of cyclosporine is administered intravenously diluted 1:20 with saline or 5% dextrose fluids over 4 hours. This dose is repeated every 12 hours until the cat can eat again and vomiting has stopped. Trough cyclosporine levels should be measured while the cat is on IV medication if this treatment is expected to continue more than a couple of days.

Cyclosporine assays should be high-pressure liquid chromatography (HPLC) or new monoclonal specific radioimmunoassay (mRIA-sp). Cyclosporine is stable in the blood for 1 week when refrigerated. It is a fairly stable chemical and does not need to be shipped on ice.

Many drugs will affect the blood levels of cyclosporine; the table below lists some drugs that decrease, increase and have no effect on the cyclosporine levels.

Increase blood cyclosporine Decrease blood cyclosporine No effect on blood cyclosporine
Metoclopramide Phenobarbital Ampicillin
Cisapride Phenytoin Clavamox
Cimetidine Carbamazine Amoxicillin
Erythromycin Trimethoprim/sulfa Enalapril
Ketoconazole, fluconazole, itraconazole Rifampin Amlodipine
Chloramphenicol Certain flavor additives  
Ciprofloxacin and likely enrofloxacin    
Danazol    
Prednisolone    
Calcium antagonists- diltiazem, nicardipine, verapamil    

Potential side effects of cyclosporine: urinary and other infections, decreased WBC and platelets, immune-mediated hemolytic anemia, high blood sugar, hypertension, diarrhea, vomiting, lymphoma, renal and liver toxicity (very unusual in cats).  Drugs that are known to have potential renal toxicity such as NSAIDs and aminoglycosides should be avoided.  Digitalis toxicity can occur with concurrent cyclosporine administration.

2.  Ketoconozole 5 to 10 mg/kg q24h PO can be used long term if a cat metabolizes cyclosporine too rapidly. The dose is adjusted to the lowest level needed to maintain adequate cyclosporine levels. Ketoconozole blocks the metabolism of cyclosporine at the level of the liver. This medication is not routinely used. With long-term use, blood dyscrasias (leukopenia, anemia) may result.

3.  Prednisolone 0.25 mg/kg BID PO for 1 month, then same dose q24h for the life of the patient. Prednisolone has an additive immunosuppressive effect with the cyclosporine even at this low dose. If the patient becomes hyperglycemic with the use of this medication, it should be discontinued.

4.  Clavamox 13.5 mg/kg BID (or 62.5 mg per average size cat) for 14 days. Antibiotics are administered as the cat will be immunosuppressed and susceptible to bacterial infection.

5.  Amlodipine (Norvasc) 0.1 mg/kg q24h is administered for hypertension if this is present preop. The dose should be adjusted as needed to normalize blood pressure. Blood pressure frequently will normalize following transplantation and amlodipine can be discontinued with tapering doses over 3 weeks.

6.  Enalapril (Enacard) 0.25 mg/kg q24h can be used to help minimize renal hypertension and slow the deterioration of the remaining native kidneys.  Cyclosporine and high doses of enalapril may result in excessively high serum K+ levels.


Potential Postoperative Complications

1.  Complications are frequently related to immunosuppressive therapy

2.  Urinary tract infections (most common)

3.  Viral upper respiratory infection

4.  Fungal infection

5.  Hypertension can be a side effect of Cyclosporine: results in seizures or blindness in the immediate postop period

6.  Hydronephrosis due to ureteral obstruction (usually occurs within 3 weeks after surgery)

7.  Rejection of the transplanted kidney; acute rejection can occur at any time if whole blood cyclosporine levels drop too low (i.e. below 100 ng/ml), hence the importance of good client compliance and frequent measurement of cyclosporine levels).

8.  Hemolytic uremic syndrome is a condition in which progressive anemia and potentially icterus develop due to hemolysis of red blood cells. The cause of this syndrome is believed to be related to cyclosporine which causes endothelial injury.  CBC shows thrombocytopenia, anemia,  and schistocytes; lactic dehydrogenase levels are elevated on biochemical profile.  A definitive diagnosis is based on renal graft biopsy which demonstrates glomerular microthrombi. Prognosis is grave.

9.  Seizures as a result of the blood being cleansed too rapidly by the kidneys. This may be fatal. As mentioned above hypertension may also cause seizures.


Postoperative Expectations

We have had a 90% success to get cats through kidney transplantation; it is unusual for a patient to die during surgery and in the perioperative period.  Our longest survivor was 8 years.  If a cat survives beyond the first 6 months, there is a very good chance that the cat will live for years.  My impression is that the cats that do the best are owned by clients that are diligent about follow-up evaluations and administering medications.  With successful transplantation and function of the graft, the following clinical and biochemical progress of the recipient should be expected:  most grafts begin producing urine within a couple of minutes of being reperfused; within 24 hours after transplantation, the BUN and creatinine are frequently about 1/4 to 1/3 less than the preop levels; BUN, creatinine, and phosphorus return to normal range within 2 to 5 days after surgery.  Urine specific gravity may not concentrate to greater than 1.035 during the hospital stay due to diuresis with intravenous fluids. By 2 to 3 weeks after surgery the urine should be concentrated.  Resumption of normal appetite and grooming behavior may take place 5-7 days after surgery.  The quality of life of the patient returns to normal if the patient does not have any other underlying disease processes (i.e. normal activity level, weight, and appetite).


Postoperative Monitoring

1.  First Seven Days After Surgery:

Complete physical examination, BUN, Creatinine, glucose, PCV, TS, albumin, electrolytes measured daily until renal values are normal, then every second or third day while in our hospital.

Ultrasound of the kidney with doppler colorflow (see photo right) to evaluate renal perfusion is done during first 3 days then at the time of release from our hospital to evaluate renal perfusion and evaluate for hydroureter. The size of the kidney is measured; a kidney undergoing acute rejection may become larged. Ultrasound should be repeated 4 weeks after surgery to check for hydroureter and for renal perfusion.

Whole blood trough cyclosporine levels: Levels are measured on days 0, 3 and at the time of discharge. 

2.  Release From hospital to 12 Weeks After Transplantation (or until the cyclosporine level is stable):

Complete physical examination (including TPR, blood pressure if previously hypertensive, and body weight), chemistry profile, CBC, urinalysis, urine culture, whole blood cyclosporine assays level weekly are performed weekly. Abdominal ultrasound is performed monthly (see table in appendix)

Cyclosporine levels must be measured weekly for the first 12 weeks after surgery, then monthly for the next 6 months, then gradually wean down to an evaluation every 3 months. Blood levels must be maintained above 500 ng/ml during the first month and around 250 ng/ml thereafter.

3.  Twelve Weeks After Transplantation:

Complete physical examination (including TPR, blood pressure if previously hypertensive, and body weight), Chemistry, CBC, urinalysis, urine culture (cystocentesis collection), abdominal ultrasound, and whole blood cylcosporine assay is performed (the frequency of this testing is gradually reduced to once every 3 months). See table in the appendix.


Rejection of renal grafts

Any signs of illness that the patient exhibits post-operatively may be associated with organ rejection. This could potentially be due to inadequate levels of cyclosporine It is imperative that continuous communication between the owner, the referring veterinarian and the transplant team members must occur in order to assure a successful outcome.

If problems arise the following protocol should be used:

1.  Contact member of transplant team

2.  Refer case back to us nearest specialty referral practice that is capable of managing transplant cases

3.  Submit blood for stat measurement of at least the following (if you are not located near a referral center):  BUN, creatinine, electrolytes, CBC, cyclosporine blood level, urinalysis, and urine culture

4.  Be prepared to treat cat with the following:  Cyclosporine 6mg/kg IV q12h; Prednisolone 4 mg/kg IV q24h; Baytril 2.5 mg/kg IV q12h (beware: >5 mg/kg q24h may cause retinal problems in cats especially with renal compromise); Ampicillin 20 mg/kg IV q6h; intravenous fluids; other instructions as directed by the transplant team.

5.  Prepare to send patient to a referral center


References

1.  Gregory CR, et al. Renal transplantation for treatment of end-stage renal failure in cats. J Am Vet Med Assoc 1992;201:285-291.

2.  Lulich JP, et al. Status of renal transplantation in the 1990s. Sem in Vet Med and Surg (Sm An) 1992;7:813-186.

3.  Gregory CR. Renal transplantation in cats. Comp Cont Ed, 1993;15:1325-1339

4.  Gregory CR et al. Renal transplantation in clinical veterinary medicine: In Kirk RW, Bonagura JD (eds): Kirk's Current Veterinary Therapy XI, Small Animal Practice. Philadelphia: WB Saunders Co, 1992, p. 870-875.

5.  Degner DA, Walshaw R, Rosenstein D. A new rapid technique for renal transplantation in the cat. Proceedings, 5th Annual Research Day, Phi Zeta, 1994.


Appendix Table 1

This table lists the schedule of testing that should be done in a transplant patient in the postop period. This is only a guideline and may be altered according to specific needs of the patient.

Week postop Trough blood cyclosporin level CBC Chemistry UA Urine Culture by cysto Abdominal ultrasound
1 X X X X    
2 X X X X    
3 X X X X    
4 X X X X X X
5 X X X X    
6 X X X X X  
7 X X X X    
8 X X X X X X
9 X X X X    
10 X X X X X  
11 X X X X    
12 X X X X X X
14 X X X X X  
18 X X X X X X
22 X X X X X X
30 X X X X X X
38 X X X X X X
46 X X X X X X
62 X X X X X X

….and the testing continues at least every third month for the life of the patient.

Frequently Asked Questions After Surgery - General Information

When should my cat have the first bowel movement after surgery?

  • Many cats will not have a bowel movement for the first 4 to 5 days after surgery
  • Reasons that a cat will not have regular bowel movements after surgery include:
    • The cat has been fasted prior to surgery
    • Cats do not eat well during the hospital stay
    • They frequently do not eat well when the go home
    • They are fed highly digestible food that produces little stool
    • Pain medication that contain narcotics (such as fentanyl patches, tramadol, morphine) can be constipating
  • If a pet does not have a bowel movement on the 5th day of being home a stool softener such as metamucil can be fed
    • Dose of metamucil 1/4 tsp per mixed in with each meal (canned cat food)

My cat had surgery and will not eat.  What can be done?

  • Offer smelly foods that contain fish such as tuna or smelly cat foods
  • Try Gerber strained meats for babies such as the chicken, beef, turkey or veal
  • Hand feeding;  place a small amount of food in the mouth so that they get the flavor
  • Warm the food slightly in a microwave as the food will be more aromatic; remember to stir the food before feeding and test the temperature with your finger; it should  be only luke-warm.
  • Some cats will only eat dry food, try kibble if your cat normally has been fed that food
  • Petting and stroking your cat frequently will help to stimulate appetite
  • Remember that most pets will not eat the first day or two after they get home from surgery
  • Appetite stimulants such as cyproheptadine may be helpful
  • If your cat refuses to eat anything for 7 days a stomach tube should be placed to provide nutrition so that a serious liver problem (hepatic lipidosis) does not develop

My cat is vomiting now that he/she is at home.  What can be done?

  • The first thing for you to discern is whether your pet is vomiting or regurgitating.  Both will result in fluid or food being brought up.  Vomiting always will have heaving or retching of the abdomen prior to expulsion of the vomitus.  Regurgitation is not associated with heaving and the cat usually just opens the mouth and fluid or food will be expelled.  Usually the regurgitant will be clear or brown colored fluid. 
  • Next is to identify the cause of the vomiting or regurgitation.
  • Causes and treatment of vomiting after surgery
    • When some pets return home after a stay in the hospital they may drink excessive amounts of water at one time and then vomit; if this appears to be happening the water should be limited to frequent smaller amounts.
    • Medications such as antibiotics are a common cause of vomiting after surgery.  In order to see which medication is causing the problem the administration of each drug should be separated 2 hours apart.  Usually the pet will vomit or appear nauseated (drooling and sick look) within 1 hour of administration of the medication that they are sensitive to.  The antibiotic in some cases may be changed to a different one, or may be discontinued. 
    • Stomach upset from anesthesia is a potential cause of vomiting and will pass within a couple of days. 
    • Unusual cause of vomiting after surgery is internal organ failure.  Blood testing will confirm this problem. For this reason vomiting should not be ignored if it persists for more than 24 hours.
    • If your pet had surgery of the bowels or stomach, vomiting is always a concern, as it may indicate that infection of the abdominal cavity, called peritonitis, is present.  Do not ignore this sign.
    • Symptomatic treatment of vomiting involves with holding food for 12 to 24 hours, then introducing small amounts of bland food such as rice and lean cooked hamburger, if your pet does not vomit after that then.  In order to decrease the acidity of the stomach Pepcid AC 0.5 mg/kg given by mouth twice daily for 5 days can sooth an upset stomach.  Metoclopramide is a good anti-vomiting medication for cats.  You should always consult a veterinary healthcare professional before administering medication.
  • Causes and treatment of regurgitation after surgery
    • The most common cause of regurgitation is reflux of acid from the stomach into the esophagus while your pet is under anesthesia.  Acidic fluid from the stomach can cause a chemical burn of the esophagus and result in a bad case of heart burn, which is called esophagitis.  This results in poor motility of the esophagus so water and food will accumulate in this structure.  In most cases esphagitis is self-eliminating and will resolve within two or three days. 
    • Regurgitation also can be caused by a neuromuscular degeneration of the esophagus and this problem will persist.  It is not associated with surgery, rather other underlying diseases.
    • If the esophagitis is severe the esophagus may develop one or more strictures.  A stricture is a narrowing or stenosis of the esophagus, does not allow passage of food down the esophagus, thus the pet has persistent regurgitation.  This problem should be brought to the attention of your doctor within the first two weeks so that it can be treated by ballooning the stricture (minimally invasive procedure as it is done with the aide of an endoscope).  If an esophageal stricture is chronic surgery is needed.
    • Symptomatic treatment of regurgitation caused by esophagitis includes feeding bland food, and administering a coating agent such as sucralfate.  You should consult a veterinary health care professional if the regurgitation continues for more than a couple of days.

How do I know that my cat is in pain following surgery?

  • Pain is more difficult to assess in cats versus dogs as signs can be more subtle and they usually do not vocalize
  • Signs of pain in a cat include the following:
    • biting if you get near the surgical site
    • growling or deep cry
    • not wanting to eat
    • hiding and not wanting to be near owner (remember that this could also be caused by the cat just being upset about leaving home and coming back)

What can be done for pain at home for my cat?

  • Pain medication such as buprenorphine or a Duragesic (fentanyl) patch
  • Tylenol will kill a cat as they lack abundant glutathione enzyme in the liver
  • Anti-inflammatories can be used, but the dose is much less than dogs and they should be given only for a few days

Is it okay for my cat to lick or scratch the incision?

  • If a cat licks the incision it will actually delay the healing process because they usually lick too much and traumatize the area.
  • Cats have a barbed tongue, therefore a lot of damage can be done in a short period of time
  • Licking can remove stitches and cause the incision to open
  • Licking can become a severe habit that is difficult to break
  • Licking can cause infection as the mouth has many bacteria
  • Cats will frequently lick the incision when the owner is not watching such as at night time; if the skin looks red or excoriated the most common cause is from licking.
  • To stop your pet from licking/scrtaching the following can be tried:
    • Elizabethan collar can be placed on the neck; this will not help stop your pet from scratching at the region
    • Cervical collar (bite not collar) is a less awkward device and can be effective at stopping a pet from licking the surgical site
    • If the incision is over the chest an infant tee shirt can be put on your pet and the waist of the shirt fastened in place with an ace bandage or duct tape.
    • If the incision is over the paw or lower limb a bandage or sock could be put on and kept up with tape.
    • Bitter apple can be applied around the incision; many dogs will continue to lick  after application of this topical
    • Bitter Apple and Liquid HeetTM (obtain this from a drugstore...it is used for sore muscles) mixed in a 2:1 ratio can be applied around the skin incision
    • Antipsychotic medication in some cases is needed

Board-certification by the American College of Veterinary Surgeons

What does it mean?

  • Four years of advanced training in surgery beyond the Doctor of Veterinary Medicine Degree

  • Experience in the development of new surgical treatments

  • Rigorous examination by the American College of Veterinary Surgeons to ensure competency in advanced surgical techniques

  • Assurance that a veterinarian is a surgical specialist

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