Liver tumor surgery in older dogs may sound like something intimidating considering that old dogs may be prone to risks. Deciding on whether to do the surgery or not can be a great subject of debate. Should you pursue liver tumor surgery in old dogs or are there too many risks involved? Unfortunately, there is no easy answer. There are several factors to consider such as the type of tumor, the breed and age of the dog and whether the dog is suffering from other concomitant health conditions that may have an impact on recovery and overall quality of life. These are all important considerations to keep in mind when making a decision.
The Objective of Surgery to Remove a Liver Mass
Dogs may be affected by a variety of tumors affecting the liver and these tumors may be or may not be malignant.
Examples of what liver masses may turn out to be include hepatocellular adenomas, hepatocellular carcinomas, nodular hyperplasia, cholangiocellular carcinomas (bile duct carcinomas), hepatic carcinoids to just name a few.
Several of these masses are malignant, but there are some that are benign (nodular hyperplasia, hepatocellular adenomas).
Unfortunately, the most definite way for differentiating with certainty a benign type of liver tumor (such as a hepatocellular adenoma), from a malignant type of liver tumor (such as a hepatocellular carcinoma), requires surgical intervention and biopsy of the mass.
"The treatment of choice for a solitary liver tumor is surgery, provided that it has not spread to another internal organ."~ American College of Veterinary Surgeons
Details About The Surgical Procedure
What happens during liver surgery in dogs? For starters, the surgeon would start with an exploratory celiotomy, which involves making an incision through the abdominal wall for the purpose of gaining access into the abdominal cavity. This procedure allows the opportunity to palpate and visualize the abdominal organs while checking for potential signs of the cancer spreading to other sites.
Once visualization takes place, the surgeon proceeds to surgically remove a tissue sample for biopsy. There are several types of biopsy that may be used for this.
For example, the"guillotine" biopsy method involves using a loop of absorbable suture to encircle and tighten a part of the dog's liver on a lobe so that tissue can be cut. A wedge resection instead removes a triangle-shaped slice of tissue. A punch biopsy may be used for masses that are more centrally located rather than on the liver's margins.
Liver lobectomy is often carried out with massive liver tumors. A dog's liver is composed by six lobes (left lateral, left medial, right lateral, right medial, quadrate, and caudate lobes), and therefore, all six lobes are carefully examined, and then, through a lobectomy, the surgeon typically removes the whole lobe of the liver that is carrying the mass.
The biopsy tissue sample is then placed in a solution of 10 percent buffered formalin and is sent out for histologic examination (it is carefully looked at by a specialist with a microscope). Results are then sent to the veterinarian who will then call the dog owner to discuss the findings and treatment options.
Once home, dogs are placed on pain medications for several days and are required to rest to recover and allow the incision to heal.
Liver Tumor Surgery in Older Dogs
Surgery is always a risk for dogs of any age, but there may be further risks in older dogs. While it is said that age is not a disease, there are complicating factors to consider when elderly dogs must be put through the stress of anesthesia, surgery and recovery.
"The morbidity and mortality of exploratory celiotomy is directly related to the patient's condition preoperatively and the morbidity of any surgical procedure performed,' points out board-certified veterinary surgeon Dr. Don R. Waldron.
Things to consider are therefore the dog's age, overall health status and compounding factors such as concomitant health issues that are related or not related directly with the liver tumor.
Dog who are old, in a debilitated state and with a certain degree of liver or other organ failure can make this surgery a rather challenging task, points out veterinary surgeon Dr. Douglas Slatter in "Textbook of Small Animal Surgery." The risks should be carefully discussed with the veterinarian and surgeon performing the surgery.
Possible complications during surgery include anesthetic complications, hemorrhage (which is usually addressed with a transfusion), liver failure, arrhythmias of the heart, ventricular tachycardia, human error.
Post-surgical (after the surgery) complications include problems with the incision, dehiscence (the edges of a wound no longer meeting), formation of seromas, infections etc. Dog owners should report to the their vet immediately upon noticing the first signs of such complications.
What a Study Has to Say
According to a study conducted in 2015, the medical records of 118 dogs that underwent liver lobectomy were reviewed. Out of these 118 dogs, 93 percent survived to discharge. It is unknown though the age of the dogs involved in this study.
The study found that dogs who were lethargic and underwent liver lobectomy had a mortality risk that was 10.2 times higher compared to that of non-lethargic dogs. This seems to suggest that dogs who were lethargic were likely experiencing illness from the liver tumor which made them less stable for anesthesia/surgery and therefore less likely to recover.
On top of this, records from this study revealed that dogs with a slower breathing rate had a mortality risk that was 4.3 times greater than dogs who had a faster breathing rate. Lower breathing rates have been associated with severe liver disease and a greater risk for sepsis.
Surgical complications took place in 15 out of the 118 dogs (13 percent). The most common complication was hemorrhage (12 percent) which was corrected with transfusions and additional stapling cartridges, hemoclips, or mattress sutures .
As to recovery, 94 percent of dogs experienced an uncomplicated anesthetic recovery. Seven out of 113 dogs (6 percent) were depressed and had low blood pressure following surgery. These dogs took longer to recover from the anesthesia and four out of the seven dogs ultimately arrested.
While none of the 118 dogs arrested during surgery, the seven dogs that experienced complications during anesthetic recovery had a mortality risk that was 100 times greater than that of dogs that experienced an uncomplicated anesthetic recovery. According to the study, it is possible that liver masses cause an increased risk for adverse effects to anesthesia.
Preventing the Risks for Complications
Veterinarians will take several preventive steps to ensure the surgery goes smoothly. The very first steps include pre-surgical bloodwork (complete blood count, platelet count, serum chemistry profile, coagulation tests considering that dogs with liver cancer may be predisposed to bleeding due to decreased synthesis of clotting factors) and urinalysis.
Several precautions taken may vary and may be based on an individual basis. For instance, dogs with liver disease may be prone to vomiting and dehydration may cause electrolyte abnormalities. Correction of such dehydration is important considering that potassium or magnesium deficiencies may predispose the dog to arrhythmias, and other complications during or after surgery.
Dogs with severe liver disease may have prolonged blood clotting times, requiring cross matching and transfusion before surgery. Chest x-rays, abdominal ultrasound and CT scans can provide helpful information for determining whether there is spread of cancer (liver cancer often spreads to the lungs) and the extent of the mass.
Since dogs with an impaired liver may have a hard time maintaining proper glucose levels in the blood, monitoring of blood glucose before, during and after surgery is important. Also, because the liver plays an important role in the elimination of most anesthetic drugs, during the surgery, the dog's breathing and heart rate is closely monitored. On top of this, veterinarians will choose drugs that are are not known to be toxic to the dog's liver.
Dogs owners play too a role in preventing complications during surgery. Prior to surgery, it's important to follow the veterinarian's instructions in not feeding the dog after a certain time the night prior to the surgery. This is important, to minimize the chances for complications.
Two Totally Different Views:
"I would never do this type of surgery in a 13 year old dog...I would give your dog liver support with Denosyl or Denamarin and supportive care as long as he is happy and then perform humane euthanasia when he is no longer happy......this is how I would handle my own dog..."~Dr. B, veterinarian
"13 years old has absolutely no effect on being able to do a liver biopsy and I would very strongly suggest you pursue this avenue. It is fairly common for veterinarians to say age is a factor since older dogs (as people) may require more care but if a dog is of good health otherwise the risk is minimal."~Dr. Altman veterinarian
What Happens if a Liver Tumor is Left Untreated?
Dogs affected by liver tumors tend to develop weakness, lethargy, loss of appetite, weight loss, vomiting and a pendulous abdomen. These symptoms tend to progress as the condition advances. Many dogs display mild to moderate anemia and elevated liver enzymes (ALT, AST, ALP).
Certain types of liver tumors may hemorrhage leading to life threatening shock due to blood loss. Dog owners must be warned about this risk and should be coached on how to recognize early warning signs of internal bleeding in dogs.
Dog owners who elect to not pursue surgery or who own dogs who aren't good surgical candidates (cancer has spread to the lungs, too much of the liver is affected), may ask their vets about providing liver support through hepatoprotective supplements such as Denamarin, milk thistle and vitamin E.
For further reading:
- Signs of internal bleeding in dogs
- Dog liver biopsy procedure and costs
- Dog cancer spread to the liver
- Life expectancy dog with liver cancer