KIDNEY CANCER
Introduction
Renal cell carcinoma (RCC) is the most common occurring neoplasm in the kidney. In the early stages of the disease no symptoms are present. However, due to the improvement of modern imaging methods (sonography, CT and MRI), a growing number of such tumors is recognized as an incidental finding while investigating for other diseases. As a result, early intervention is possible before the progression of the disease. Hematuria (blood in urine), flank pain and palpable mass are non-specific symptoms of the disease usually found in more advanced stages.
The prognosis depends on the stage of the disease. Small tumors in early stages can be cured (without any recurrence) in more than 90% of cases. When a total excision of the tumor by partial or radical nephrectomy has been performed and histology demonstrates that the tumor is located exclusively in the kidney, the 5-year survival ranges between 60-70%. In case of tumor extending outside the kidney or the presence of distant metastasis, the prognosis is poor.
Abdominal ultrasound is the initial imaging modality to visualize renal anatomy. I case of any doubts computer tomography (CT) is indicated. The full radiological assessment is done with CT of the chest and abdomen to determine the size of the tumor and exclude distant metastases. If involvement of renal vessels (including tumor thrombus) is suspected, MRI (Magnetic resonance Imaging) angiography may be required to determine the extension of the thrombus in renal and abdominal vessels. Presence of the renal tumor on CT is usually sufficient for proceeding to surgical treatment. Percutaneous needle biopsy is required only in doubtful cases and in older and ill patients not eligible for the proposed surgery.
The surgical removal of the tumor is the treatment of choice for most of the renal tumors. Depending on the size and localization of the tumor as well as radiological appearance partial nephrectomy (removal of the lesion) or radical nephrectomy (removal of the whole kidney) can be proposed. Radical nephrectomy is the removal of the entire kidney with the surrounding fat and in some cases the ipsilateral adrenal gland (of the same side). In case of small, peripheral tumors, or in cases which require maximum preservation of renal function (eg, contralateral kidney with impaired renal function), the performance of partial nephrectomy is indicated. In the latter procedure, only the tumor is excised and the remaining kidney remains intact. In cases with bilateral tumors or patients with significant operative risk who cannot undergo nephrectomy, minimally invasive methods such as cryotherapy, high intensity focused ultrasound, and embolization of the kidney proved useful tools in dealing with the disease.
Laparoscopic radical nephrectomy is performed through small skin incisions on the abdominal wall with the help of laparoscopic instruments. During the procedure the kidney is completely removed. After the nephrectomy, the surgical specimen is placed in a special collection bag and is extracted out of the abdominal cavity. One of the incisions is extended by some centimeters and the kidney is removed. The significant advantages of laparoscopic nephrectomy in comparison to open nephrectomy are the smaller abdominal wound, lower blood loss and less post-operative pain. As a result, the cosmetic result is superior, the patient recovers faster and returns to pre-surgery physical activity significantly quicker.
Laparoscopic partial nephrectomy is considered one of the most demanding operations in terms of laparoscopic skill. The oncologic principles of laparoscopic partial nephrectomy are the same as radical nephrectomy and require the complete excision of the tumor until the healthy tissue margins. However, the main difference compared to radical nephrectomy is the excision of the tumor only, which requires a transient interruption of blood circulation in the kidney in order to perform the procedure with minimal blood loss. The interruption of renal perfusion is achieved by placing a clamp on the renal artery resulting in ischemia of the kidney. Prolonged ischemia may cause irreparable damage to the kidney. Thus, the procedure should be performed in a time sensitive manner. Only centers of extensive laparoscopic experience are capable into performing laparoscopic partial nephrectomy efficiently.
Developments in laparoscopic surgery are leading to the improvements of the technique while possessing similar outcomes. In addition, these techniques provide improved cosmetic outcome and less morbidity. The single-port (Laparoendoscopic single site surgery) laparoscopic nephrectomy and transvaginally- assisted laparoendoscopic single-site nephrectomy are the recent laparoscopic urologic procedures. In single-port laparoscopic surgery, all instruments are inserted through the umbilicus and other abdominal incisions are avoided. At the end of the procedure, the umbilical incision is sutured and concealed in the umbilical fold resulting in “scarless” surgery. Moreover, the performance of only one incision reduces the possibility for related complications (wound infection, hernia formation). In transvaginally- assisted laparoendoscopic single-site nephrectomy, the female vagina is used for the access of laparoscopic instruments into the abdomen in addition to the insertion of instruments through the umbilicus. The vagina is then used for the removal of the surgical specimen at the end of surgery. The suturing and healing of the vaginal access is excellent and painless. This procedure assures good aesthetic outcomes.
The postoperative course after laparoscopic nephrectomy or partial nephrectomy is associated with minimal pain. The patient is mobilized and fed the first day after surgery. A drain tube which is inserted at the end of the procedure is removed on the first postoperative day. The patient leaves the hospital on the 2-3 day after surgery.
The main complication associated with nephrectomy is the massive bleeding from large vessel injury (renal artery and vein, posterior lumbar arteries, adrenal vessels, aorta, vena) during the performance of the procedure. Although the majority of cases the blood loss during laparoscopic nephrectomy is negligible, massive bleeding can be observed in rare cases and can be life-threatening for the patient. Bleeding is controlled in the majority of the cases laparoscopically. Open surgery is rarely necessary for hemostasis. Injury to adjacent organs is also possible. In the case of partial nephrectomy, blood loss is usually higher than in radical nephrectomy. The leakage of urine from the kidney to the abdomen and bleeding are rarely seen postoperatively. While most of the complications are managed conservatively, secondary specific intervention can be required in several cases.