Achilles PloumidisMD, BSc, MSc, PhD, FEBU Urologist Center for Robotic & Laparoendoscpic Urologic Surgery (CRoLUS) Athens Medical Center
Precision in the resection of the tumor maximizes the function result of the kidney.
The role of the kidney
The kidneys are biological filters of the human body, that filter 200 liters of blood in a daily basis, thus removing harmful and unwanted metabolic products by excreting them through the urine. Their role also extends in aiding in the production of red blood cells, activating vitamin D and producing substances that regulate the arterial blood pressure. Both kidneys (right and left) are anatomically situated on either side of the lumbar spine just under the diaphragm and are covered with fat for protection.
Renal Cancer
Renal cancer or tumor of the kidney is the 8th most common cancer in men and the third most common cancer of the urinary tract. Statistically it is observed after the 6th decade of life and it affects men twice more often than women.The most common renal tumor, corresponding to 85% of all type of renal cancers is the Renal Cell Carcinoma (RCC). Every year, 30.000 new cases of RCC are diagnosed only in Europe while studies reveal that in the USA this number exceeds 65.000.
Risk Factors for RCC
According to recent studies contributing factors for renal cancer are: smoking, high arterial blood pressure, dietary factors, obesity, family history, advanced kidney disease (renal insufficiency) and certain types of syndromes. Additionally, workplace exposure to certain substances, such as Cadmium, increases the risk for RCC.However, having a risk factor or even several risk factors doesn’t mean that someone will get the disease.
Symptoms of RCC
The most common symptoms of renal cancer are: hematuria (blood in the urine), pain or sense of heaviness in the lumbar region, palpable mass in the abdomen, sudden loss of weight, weakness, fever, high blood pressure or even anemia.Nonetheless, it is important to highlight that today in most cases, RCC is asymptomatic and is incidentally found on imaging studies (ultrasound, computed tomography etc.).If diagnosed on time and with prompt therapy, renal cancer can be cured. Specifically, recent data suggest that RCC cure rates can reach up to 80% or even 100%.
Diagnosis of RCC
Imaging studies are the front line defense in the diagnosis of renal cancer. Abdominal ultrasound (US) is very often offered to patients due to low cost and relatively high sensitivity. When a suspicious mass is observed further imaging studies are suggested such as: computed tomography (CT), intravenous urography (IVU) or even magnetic resonance imaging (MRI). The former imaging studies can not only reveal a possible metastasis of the tumor but with the help of advanced software, can also offer the surgeon a three-dimensional (3D) reconstruction of the tumor, aiding in the decision making for the best surgical therapy.
Therapy of RCC
When the tumor is confined to the kidney and its anatomical position and size allows for radical resection with minimal harm to the organ, partial nephrectomy is indicated. This means that the surgeon removes only the tumor and not the entire kidney, thus leaving intact healthy renal tissue and avoiding future renal insufficiency.
Partial Nephrectomy
Partial nephrectomy can be achieved by three kinds of surgical methods: conventional open surgery, laparoscopic surgery and robotic surgery. During the last decade with the implementation of new technologies in modern operating theaters and the advances in surgical technique, patients can appreciate the benefits of minimal invasive surgery. Contemporary operations avoid large incisions and unnecessary trauma to the tissue with consequent inflammation and aim in offering the same or even better oncological and functional results through the so called “button hole” surgery (Figure 1). Minimal access surgery is not solely about aesthetic results, but has proven its benefits especially in the post-surgical period for the patient, where the tissue stress as well as the total stress is minimal, thus giving the possibility for faster recovery. For the above-mentioned reasons, most centers in Europe and in the USA have adopted minimal access surgery in most if not all operations.
Robotic surgery is considered the evolution of laparoscopic surgery and although both methods are “minimal invasive”, robotic surgery indisputably concentrates more advantages for the surgeon as well as the patient. The surgeon with the use of the robotic platform,known as Da Vinci (Intuitive Surgical Inc.), sits comfortably in front of a console from which he performs the operation by manipulating specially designed joysticks (Figure 2). However, the robot does not function independently, nor is programed to operate on its own. Instead, the surgeon’s movements on the joysticks are transferred to the robotic arms with the aid ofa sophisticated software that is based on a “master-slave” protocol. This gives the ability to the surgeon to operate with unparalleled precision due to the elimination of natural hand tremor, while the scaled flawless motion of the robotic arms transmit in real time the surgeon’s actions to the operating field. Additionally, the console offers a three-dimensional environment thanks tothe specially designed robotic camera with unique optical clarity. The magnified, up to 15 times surgical field, givesreal depth of field revealing tissue details in order to perform micro-dissection when needed. Practically, the surgeon can access the kidney, through four small holes on the abdominal wall and subsequently resect the tumor and suture the remaining healthy organ with precision.
Robot-assisted Partial Nephrectomy (RAPN)
The procedure is performed under general anesthesia. In order to create the necessary space for the instruments, the abdominal cavity is filled with air (pneumoperitoneum), while the robotic camera and the robotic tools are inserted through four minor incisions on the skin. Initially the surgeon mobilizes the necessary tissues in order to gain access to the kidney. Afterwards, the surgeon proceeds with the clumping of the renal hilum (Figure 3). This part of the operation is mandatory in order to resect the tumor with the minimum blood loss and with accuracy and safety. After completing the removal of the tumor, the healthy remaining part of the kidney is sutured and reconstructed. The renal hilum is unclumped and the kidney is reperfused. The specimen is placed in a special endoscopic bag and removed from the abdomen.
Throughout the procedure, the surgeon whilesitting in the console and operating can view the surgical field and at the same time observing the 3D reconstructed model of the tumor uploaded from the CT images done preoperatively. Thus the surgeon knows what to expect and can easily compare his operative field with the preoperative 3D tumor model. This capability (TilePro™, Intuitive Surgical Inc.) is offered by the current generation robotic platform (da Vinci Si HD, Intuitive Surgical Inc.)in Athens Medical Center and combines images reproduced by the Department of computed tomography. Subsequently a combination of accurately locating and identifying the tumor as well as meticulous dissection of the massis achieved with the aid of the robotic instruments.
The advantages of robot-assisted partial nephrectomy
The goal in any partial nephrectomy is to achieve:
- Radical resection of the tumor (oncological result)
- Preservation of as much as possible healthy renal tissue (functional result)
- Minimization of the renal hilum clumping (warm ischemia time)
Success in all of the above levels is accomplished thanks to the technological innovations of the robotic platform. The three-dimensional vision combined with the ergonomic position of the surgeon on the console offers optimum environment for a demanding operation such as RAPN. At the same time, the miniaturized wristed instruments (EndoWrist® Instruments, Intuitive Surgical Inc.) give the opportunity to dissect the tissue in every possible angle and render suturing of the renal defect easier, safer and bloodless. With the additional degrees of freedom that the wristed robotic instruments offer, the surgeon can tackle even more challenging tumors, thus extending the indications for partial nephrectomy. These features converge to a safer operation with minimal clumping time of the renal hilum and maximal functional result.
The advantages of robot-assisted partial nephrectomy compared to conventional open and laparoscopic partial nephrectomy are significant for the patient. These include:
- Maximizing the oncological and functional result with minimum warm ischemia time. The tumor is radically resected leaving only healthy tissue behind which is then reconstructed in order for the kidney to function again. Thus the kidney is preserved and potential renal insufficiency is averted.
- Minimal blood loss and less need for blood transfusion.
- Significantly less postoperative pain and less need for consumption of analgesics.
- Fast recovery. Hospital stay is usually 2-3 days, while convalescence to normal everyday work is rapid. This is due to the fact that major trauma and incisions are avoided.
- Better aesthetic result. By avoiding large, sometimes more than 20 cm, incisions (used in open surgery) and have the operation done through four small incisions in the skin the likelihood of hernia is diminished.
- Less postoperative complications (depending also on surgeon’s experience.
