Case Examples
Ovariohysterectomy
Minimally invasive ovariectomy or ovariohysterectomy can be performed safely and rapidly and is now considered a routine laparoscopic procedure. During this procedure a small camera port is established one centimeter below the umbilicus. Using the Hasson technique a trocar- cannula is inserted into the tiny incision in the body wall which allows abdominal insufflation to proceed.
Using a mechanical insufflator that has a pressure feedback mechanism we can insufflate the abdomen with carbon dioxide without exceeding the maximal recommended intra-abdominal pressure of 15 mmHg. Once a pneumoperitoneum is established we can place two further ports that allow instruments into the abdomen with which we can manipulate the ovaries and the body of the uterus.
Using special vessel-sealing technologies used routinely in human laparoscopic surgery we are able to safely seal the blood vessels that supply the ovaries and uterine body even in very large dogs. Once the blood supply to the ovaries and uterus has been removed it is possible to exteriorize the organs from the body which is done by slightly increasing the size of one of the port incisions. At the end of the procedure the dog is left with three tiny 1cm incisions.
Cholecystectomy (Removal of the Gall Bladder)
Figure 1. (right)
The gall bladder has been placed in a specimen retrieval bag ready for aspiration of bile and subsequent retrieval from the abdomen.
“Rhepp”, a nine year old miniature schnauzer
“Rhepp” , a nine year old miniature schnauzer, presented to the minimally invasive surgery service after his owners had had some routine bloodwork performed which demonstrated some abnormalities in his liver bloodtests. After further investigation and an ultrasound scan he was found to have a developing biliary mucocele. This is a condition where thick sludgey bile builds up in the gall bladder over a period of time. “Rhepps” owners had monitored this build up over the previous two years until the point when his gall bladder was almost completely full of thick congealed bile. When this occurs there is a risk of two serious problems occurring. Either the bile can cause a blockage of the biliary tract or the gall bladder can burst spilling bile into the abdominal cavity. Either of these events can make a dog very sick and is associated with an approximate 20-40% mortality rate even if surgery is performed rapidly to remove the gall bladder. Rhepp’s owners decided to try and prevent either of these things from happening by having his gall bladder removed while he was still very healthy.
We decided to perform a laparoscopic cholecystectomy. This procedure involves making four very small incisions for the placement of ports into the abdomen. Through these ports the organs can be manipulated. In this case the gall bladder was dissected out and the cystic duct (the connection of the gallbladder to the rest of the biliary tract) was ligated using extracorporeally-tied laparoscopic slipknots. After the gall bladder was freed from the surrounding liver it was placed in a specimen retrieval bag (Figure 1). Once in this bag the bile inside the gall bladder was aspirated thus allowing the specimen to be removed through a much smaller incision that would normally be necessary. The traditional “open” approach necessitates removal of the gall bladder through a large abdominal incision. Rhepp recovered from this surgery very well and went home 48 hours after the operation.
Figure 2.
Postoperatively, only four very small incisions are seen where the ports were placed for the introduction of instruments. The slightly larger incision on midline is where the specimen was retrieved from.
Figure 3.
Rhepp at home happy and healthy three weeks post-operatively.
Pericardectomy
Figure 1. (right) One lung ventilation – This procedure requires the use of a special anesthetic technique called one lung ventilation where one side of the lung is deliberately collapsed to allow more room to operate in the chest cavity. With careful monitoring this is a very useful and safe technique.
Patches, a 5 year old English Springer Spaniel
Patches, a 5 year old English Springer Spaniel, presented to our clinic due to coughing and shortness of breath. Patches chest radiographs revealed that he had a build of fluid in his chest (pleural effusion) that was preventing his lungs from expanding normally. He was referred to our cardiologists who did an echocardiographic examination which revealed that he was suffering from a disease known as restrictive pericarditis. In this condition the sac that normally suspends the heart within the chest cavity becomes thickened and fibrous and prevents the heart from expanding normally. The result is an inability of the heart to allow normal flow of blood into the heart resulting in a build of “back-pressure” in front of the heart. The result is that fluid leaks out of the blood vessels and accumulates within the chest and abdominal cavities which eventually restricts breathing. The treatment for this condition is to remove the entire pericardial sac from around the heart. Using thoracoscopic access to the chest we were able to resect the entire pericardial sac and remove it from the body. After the surgery we were able to prove that we had relieved the abnormal pressure within the heart by passing catheters into the chambers of the heart and measuring the relevant pressure profiles.
Figure 2. (left) Half way through the procedure the removal of the pericardial sac from one side is complete. Now the other side will be cut just below the level of the phrenic nerves to ensure there is no remaining pericardial tissue to constrict the heart.
Figure 3. The completed subtotal pericardectomy. The entire pericardium has been removed.
Thymoma excision
Figure 1 : The CT image above shows the location of the thymoma (white measurement line shown) cranial to the heart and located just underneath the cranial vena cava.
Thoracoscopy was also used to remove a thymoma from the chest of an 11 year old Labrador retriever that had originally presented for difficulty breathing. We diagnosed laryngeal paralysis for which a surgical procedure called a tie-back was performed. At presentation chest radiography had revealed a mass in the cranial mediastinum which was subsequently diagnosed by ultrasound-guided tru-cut biopsy to be a thymoma. Eight weeks after recovery from the tieback procedure we proceeded with thoracoscopic thymoma resection. Pre-operatively a CT scan was used for surgical planning and to define the exact anatomical landmarks of the tumor. This planning is essential to ensure that the mass is not invading the large blood vessels in the cranial mediastinum.
A telescope and instrument port were established that allowed visualization and manipulation of the mass for dissection. Then a mini-thoracotomy approximately 4cm in length was established at the second intercostal space on the left hand side.
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Figure 2: Use of the harmonic scalpel (Ethicon Inc.©) greatly facilitated the dissection of the mass within the chest.
Once the mass was completely dissected the mass was inserted into a specialized specimen collection bag. This is an important step as if the tumor is removed straight from the chest it is possible that some tumor cells may be shed onto the chest wall when the tumor is pulled out of the incision leading to the establishment of new tumors.
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Figure 3: After dissection the tumor has been manipulated into a specialized specimen retrieval bag and is being removed from the chest cavity through the mini-thoracotomy that was created.
This dog recovered well from surgery and continues to do well. The use of thoracoscopy to remove this tumor meant that a median sternotomy (a procedure where the bones of the sternum are split with a bone saw to allow access to the chest cavity) was avoided allowing a faster and much less painful recovery.
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