Dr Marius C. Conradie
· Less invasive
· More effective
When one loses one kidney due to kidney cancer, there is a high possibility the patient may require life long dialysis or a kidney transplant. Today new techniques and technology can prevent this debilitating consequence of renal cancer.
With the evolution of robotic technology for surgery, robotic-assisted partial nephrectomy has evolved as a technique that offers similar oncological outcomes to laparoscopic and open techniques. However, with the added advantage of improved maneuverability and precision, it dramatically reduces renal ischemia times and therefore improves postoperative renal function.
Overview of kidney cancer
Kidney cancer (most commonly is renal cell carcinoma) is one of the top ten commonly diagnosed cancers in men and women. Renal cell cancer originates from the renal cortex, specifically from the proximal convoluted tubule of the nephron. While the incidence of renal cell carcinoma is increasing, there is also an increased rate of cancer detection because of the common use of cross-sectional imaging and ultrasound examination of the abdomen. As a result, many cancers are detected at earlier stages, increasing the available treatment options.
Evidence also shows that many small kidney cancers may be indolent and may progress slowly, but there is no reliable method for predicting which patients will develop metastatic cancer. Although several systemic treatments have been developed in the last decade, the outcomes for metastatic renal cell carcinoma remain poor. As a result, aggressive treatment is usually recommended in patients who do not have serious medical comorbidities.
If the cancer is detected early, nephron-preserving surgery (partial nephrectomy) can be performed, meaning that the cancer can be removed without removing the entire kidney. Tumors that are too large before they are detected, requires total or radical nephrectomy.
As the understanding of renal cell carcinoma has evolved, the role of partial nephrectomy has expanded. Partial nephrectomy was originally offered only to patients with a solitary kidney, bilateral masses, or poor renal function. Gradually, partial nephrectomy became the standard of care among patients with renal masses smaller than 4 cm, and many surgeons argue that partial nephrectomy is currently the standard of care regardless of tumor size, when technically feasible.
The normal position of the kidneys in the retroperitoneal space makes it particularly difficult to access with open surgery. However, with laparoscopic or robotic surgery, the retroperitoneal organs can be very easily accessed and this approach lends itself perfectly to reconstructive procedures of the kidneys.
The cause of kidney cancer is not fully understood. Most cancers occur sporadic without any genetic predisposition. However, certain factors appear to increase the risk of kidney cancer.
Risk factors for developing cancer of the kidney are:
1. Smoking. If you smoke cigarettes, your risk for kidney cancer is twice that of nonsmokers.
2. Men are about twice as likely as women to get kidney cancer.
4. Using certain pain medications for a long time.
5. End stage renal disease or being on long-term dialysis.
6. Having certain genetic conditions, such as von Hippel-Lindau disease, hereditary papillary renal cell carcinoma and Tuberous sclerosis.
Having a family history of kidney cancer, the risk developing kidney cancer is much higher in the children and siblings of those individuals with the genetic type of kidney cancer. These patients can also expect to get the cancer at an earlier age and are more likely to have more than one tumor, either in one kidney or in both kidneys.
7. Being exposed to certain chemicals, such cadmium, benzene, organic solvents, or certain herbicides.
9. Cystic diseases of the kidneys.
Having these risk factors does not mean you will get kidney cancer. And it's also true that you can have none of them and still get the disease.
Symptoms and signs associated with kidney cancer
Generally people may have no early symptoms of kidney cancer. It is only when the tumor starts to grow larger that symptoms may appear. The following symptoms are associated with kidney cancer in a more advanced stage:
1. Blood in the urine
2. Pain in the back or flank area
3. Palpable mass in the flank/abdomen
4. Weight loss
5. Loss of appetite
6. Fever of unexplained cause
9. Bone pain in cases where the cancer has metastasized to the bone
Confirming the diagnosis of kidney cancer and preoperative screening
If your patient have any of the major symptoms just mentioned, the most obvious being blood in the urine, abdominal pain or palpable abdominal mass, they need to be referred a urologist that specializes in kidney cancer as soon as possible.
The preoperative screening is largely based on anesthesia risk, tumor stage, size of the tumor and it’s location. Any candidate suitable for an open partial nephrectomy is suitable for a laparoscopic or robot partial nephrectomy.
Preoperative evaluation should include stratification of cardiovascular risks, serum laboratory studies, and 3-dimensional CT imaging to accurately delineate the relationship of the mass to the renal vasculature and collecting system. The number of renal vessels and any aberrant vasculature should be noted.
Generally to confirm the diagnosis a biopsy of the mass is not necessary as a CT scan are very sensitive in making a diagnosis of kidney cancer.
Indications for minimally invasive kidney cancer surgery
Nephron-sparing surgery is an established treatment for renal tumors smaller than 4 cm in diameter. The standard open approach to partial nephrectomies has been permeated in recent years by laparoscopic surgery, allowing for a minimally invasive approach to this surgery.
The general indications for an partial nephrectomy apply to bilateral synchronous or metachronous tumors, tumor in a solitary or solitary functioning kidney, or renal tumors as a manifestation of syndromes such as von Hippel-Lindau (VHL) disease or Birt-Hogg-Dubé (BHD) syndrome, given their multifocality and bilaterality.
New treatment options for localized renal cell carcinoma
There are several standard types of treatment for kidney cancer. Surgery remains the main treatment modality for kidney cancer, as this type of cancer is largely resistant to chemotherapy and radiation therapy.
In patients with renal cell carcinoma confined to the kidney (pathologic stage T1 or T2), surgery is effective treatment, with 5-year cancer-free rates of around 95%. For 5 decades, the recommended treatment was complete removal of the kidney (radical nephrectomy), which was effective but associated with an increased risk of chronic renal failure as well as major morbidity during the convalescence time.
Historically, partial nephrectomy was not offered as a standard treatment to otherwise healthy patients but was reserved for patients with a solitary kidney, poor renal function, or bilateral tumors. However, in the 1990s, preserving renal function by removing only the tumor was popularized and accepted for selected patients with small renal masses. To date, the vast majority of studies have shown equivalent cancer control in patients treated with complete removal of the kidney compared to the patients where only the tumor was removed. In the American Urological Association (AUA) guidelines for small renal masses, when technically feasible, partial nephrectomy is the standard option for treatment of tumors less than 4 cm in otherwise healthy patients.
Urologists experienced in laparoscopic and robotic surgery can now operate on tumors larger than 4 cm and more complex central renal masses. The main advantage with robotic assistance is its added dexterity and improved manipulation of the tumor, allowing for rapid control of postexcisional bleeding and renorrhaphy while minimizing blood loss and ischemia time.
As part of the operative success, it is critical to plan intraoperative hilar dissection and clamping. In addition, tumor size, location, endophytic nature, and proximity to the collecting system are examined on preoperative imaging, and a renal nephrometry score should be determined. Arrangements should also be made for intraoperative ultrasonography to more precisely mark out the tumor prior to resection.
Potential advantages of robotic-assisted partial nephrectomy include a 3-dimensional stereoscopic vision, articulating instruments, and scaled-down movements and reducing tremor. However, robotic-assisted partial nephrectomy is a technically challenging procedure because of the time constraints posed by hilar clamping. When the renal hilum is clamped, every minute of ischemia may decrease the patient’s subsequent renal function. Therefore, the surgeon should be well versed with handling and troubleshooting the robotic interface.
This large renal tumor of 19cm was successfully removed laparoscopically at Netcare Waterfall City Hospital. The specimen weighed 3.4 kg, the largest renal tumor that has ever been removed by laparoscopic approach.
Small renal tumor situated at the polar regions of the kidney and has an exophytic growth pattern, makes it ideal for partial nephrectomy or nephron sparing surgery.
With the tumor being removed, the specimen will be histologically examined for cell type, grade and completeness of resection (negative margins). The function of the remaining part of the kidney will be minimally affected. With a partial nephrectomy, only 10-15% of normal renal tissue is sacrificed. Minimally invasive techniques to perform partial nephrectomies translate to faster recovery time and better esthetic outcomes for the patients. Either laparoscopic or robotic surgery techniques have set the new standard of care in kidney cancer worldwide and are now also available in SA.
Illustration of the technique of how only part of the kidney containing the kidney cancer is being removed. This is a highly skillful surgery due to the delicate blood supply to the kidney.
Other techniques that limit the morbidity of treatment for small renal cell carcinomas include active surveillance and percutaneous ablation (cryoablation, radiofrequency ablation, and microwave ablation). However, ablation techniques and surveillance have not demonstrated equivalent cancer outcomes to surgery and are not generally offered to otherwise healthy patients as first-line treatment.
Partial nephrectomy is done with laparoscopic or robotic surgery. Robotic surgery is the ultimate treatment of choice because of the precision it offers in this delicate type of operation.
Laparoscopic and robotic techniques allow for smaller incisions, reduced postoperative pain, and hastened recovery time. As these techniques evolved, several authors demonstrated the feasibility and favorable cancer control and functional outcomes provided it being performed in high volume centers and by experienced laparoscopic/robotic surgeons. Netcare Waterfall City Hospital in Midrand, Johannesburg is one of the hospitals in South Africa with such a profile and has the expertise to perform this type of surgery. For more information on laparoscopic and robotic treatment of kidney cancer, you can visit the African Endourology Society’s website at www.endourology.org.za.