Radical Nephrectomy 

Nephrectomy has many indications, for both simple and radical approaches.

A simple nephrectomy is indicated in patients with irreversible kidney damage due to symptomatic chronic infection, obstruction, calculus disease, or severe traumatic injury. Simple nephrectomy is also indicated to treat renovascular hypertension due to noncorrectable renal artery disease or severe unilateral parenchymal damage caused by nephrosclerosis, pyelonephritis, reflux dysplasia, or congenital dysplasia of the kidney.

Radical nephrectomy is the treatment of choice for localized renal cell carcinoma (RCC). In certain circumstances, radical nephrectomy is also indicated to treat locally advanced RCC and metastatic RCC.

With the advent and increasingly mainstream use of abdominal CT scanning and ultrasound imaging in recent years for various abdominal and, occasionally, chest complaints, incidental detection of RCC has increased in asymptomatic patients. Currently, more than 50% of RCC cases are detected incidentally. These tumors tend to be smaller and of lower stage, resulting in better survival rates, lower recurrence rates, and lower metastasis rates than RCC detected in symptomatic patients. Symptomatic RCC presents at a significantly higher stage and grade, and tumors are substantially more aggressive than incidentally discovered lesions, particularly at later stages.

• 1869: Gustav Simon performs the first planned nephrectomy for the treatment of ureterovaginal fistula.
• 1878: Kocher performs an anterior transperitoneal nephrectomy through a midline incision.
• 1881: Morris performs the first nephrolithotomy; he later defines the terms nephrolithiasis, nephrolithotomy, nephrectomy, and nephrotomy.
• 1884: Wells performs the first partial nephrectomy to remove a perirenal fibrolipoma.
• 1913: Berg uses a transverse abdominal incision for securing the renal pedicle to remove vena caval tumor thrombi through a cavotomy.
• Early-to-mid 1900s: The retroperitoneal flank approach becomes preferred because of the lower incidence of peritonitis and other abdominal complications associated with the anterior approach.
• 1950s: The development of safe abdominal techniques leads to the revival of the anterior approach.
• 1963: Robson described radical nephrectomy and the improvement in survival with the procedure.^[1]
• 1990: Clayman performs the first laparoscopic nephrectomy at Washington University.

Frequency

Overall, the vast majority of incidentally discovered renal masses are cysts. Abdominal CT scanning reveals a simple renal cyst in 25% of patients older than 40 years. Others report the presence of renal cysts in more than 50% of men older than 50 years. When a patient presents with a renal mass in association with macroscopic hematuria, flank pain, or a palpable mass, the chance of the mass being renal cell cancer is approximately 50%. Other renal masses, specifically angiomyolipoma, renal pelvic tumors, and other benign lesions, all are relatively uncommon, accounting for approximately 5% of all renal masses among asymptomatic patients.

Several factors have been associated with increased risk of RCC.

• Obesity and cigarette smoking are the most consistently established causal risk factors, accounting for more than 30% and 20% of renal cell cancers, respectively.^[2]
• Hypertension as an independent factor is associated with increased risk of RCC.^[2]
• Analgesic use was once considered to be a more significant etiology than recent reports have indicated.^[2]
• A family history of RCC is associated with a 2- to 3-fold increased risk of RCC. However, a familial predisposition is identified in less than 2% of RCC cases.^[2] The identification of families with a predisposition to the development of renal neoplasms, including von Hippel-Lindau (VHL), hereditary papillary renal carcinoma (HPRC), Birt-Hogg-Dubé (BHD), and hereditary leiomyomatosis and renal cell cancer (HLRCC), has enabled the identification of the different genes for these cancers.^[3]

Traditionally, RCC is diagnosed after any or all of the classic triad of symptoms, ie, flank pain, palpable mass, and hematuria, have been investigated (see image below). However, with the increased use of imaging techniques over the past 2 decades, up to 72% of RCC cases are identified incidentally after investigation for unrelated abdominal pain or other non-urologic symptoms.

Presenting symptoms may be related to bleeding in the tumor, resulting in stretching of the renal capsule and pain. Bleeding into the collecting system also causes pain due to clot formation and ureteral obstruction. Local invasion and clot extension into the vena cava is suspected in patients presenting with lower extremity edema, varicocele, dilated superficial abdominal veins, proteinuria, pulmonary embolism, a right atrial mass, or no function in the involved kidney.

Lack of early warning signs characterizes RCC, resulting in a high proportion (one third) of patients with metastases at diagnosis. These patients face a dismal prognosis; the 5-year survival rate is less than 10% and the average survival is only 6-12 months. Weight loss, fever, and night sweats may suggest metastasis.

Radical nephrectomy remains the procedure of choice for surgically resectable lesions. Relapse occurs in 20-30% of patients with completely resected RCC after radical nephrectomy. Radical nephrectomy is also indicated in patients with metastatic disease as part of immunotherapy or the new chemotherapy protocol as a palliative procedure in cases of intractable pain and bleeding. Many cases are now treated with new FDA-approved tyrosine kinase inhibitors as adjuvant therapy. In addition, several new medications are now in phase II and phase III trials for the management of metastatic renal cancer. Results so far have been promising in terms of improving survival and delaying progression.

Predictors of relapse include symptomatic disease, high Fuhrman grade of tumor, high pathological stage, microvascular invasion, and necrosis. In these patients, neither postnephrectomy radiation therapy nor adjuvant interferon-alpha administration delays relapse or increases overall survival rates compared with observation alone. Therefore, observation remains the standard of care following radical nephrectomy for renal cell cancer.

The kidneys are paired vital organs located on either side of the vertebral column and embedded in the intermediate stratum of retroperitoneal connective tissue. The perirenal fascia, also called the Gerota fascia, encloses both the kidneys and adrenal glands.

Renal malignancies tend to remain within this fascia and can be excised completely by removing the kidney and its surrounding fascia as a single entity. In most individuals, a single renal artery and vein enters the kidney medially through the renal hilum, but multiple renal arteries are not uncommon.

The renal artery arises from the lateral aspect of the aorta, just below the superior mesenteric artery, and passes behind the renal vein. The main renal artery then divides into 4-5 segmental vessels to supply the corresponding renal parenchyma. These segmental vessels are end arteries without collateral circulation; thus, any injury to the renal artery at any level results in infarction of the corresponding parenchyma.

Unlike the renal arteries, the renal parenchymal veins intercommunicate freely among the various renal segments. Usually, a single renal vein joins the inferior vena cava on its lateral aspect. Multiple renal arteries occur unilaterally in 23% of the population, whereas multiple renal veins are less common.

The right adrenal gland lies above the kidney posterolateral to the inferior vena cava. The inferior phrenic artery is the main blood supply, with additional branches from the aorta and renal artery. The venous drainage usually is through a common vein on the right, exiting the apex of the gland and entering the posterior surface of the inferior vena cava. This vein is short and fragile and is a common source of bleeding during right adrenalectomy. The left vein empties directly into the left renal vein approximately 3 cm from the inferior vena cava and often opposite to the gonadal vein. Not well-recognized is the left inferior phrenic vein, which typically communicates with the adrenal vein but then courses medially and can be injured during dissection of the medial edge of the gland.

The paired gonadal arteries arise from the anterolateral aorta at a level somewhat below the renal vessels. Occasionally, a gonadal artery arises from the ipsilateral renal artery or from the aorta above the level of the renal vessels. In their retroperitoneal course, the gonadal arteries pass anteriorly to the ureter on either side. Gonadal veins parallel the gonadal arteries in their inferior course but, superiorly, tend to be more lateral and closer to the ipsilateral ureter. The left gonadal vein usually enters the inferior aspect of the left renal vein perpendicularly. The right gonadal vein usually drains obliquely into the right lateral aspect of the inferior vena cava, below the level of the right adrenal vein.

Nephron-sparing surgery (NSS) has become a successful alternative treatment to radical nephrectomy for RCC when a functioning renal parenchyma must be preserved, such as in patients with (1) bilateral RCC; (2) RCC involving a solitary functioning kidney; (3) chronic renal insufficiency; or (4) unilateral RCC with a functioning opposite kidney at risk for future impairment from an intercurrent disease, such as calculus disease, renal artery stenosis, diabetes, hypertension, or nephrosclerosis. Novick played an important role in establishing NSS, proving its efficacy and safety, and describing the ideal technique.^[4]

Several studies have confirmed that NSS provides curative treatment that is as equally effective as radical nephrectomy in patients who have a single, small (< 4 cm in diameter), unilateral, localized RCC. NSS is also becoming increasingly recognized as effective treatment for small, select, incidentally discovered tumors, even when the contralateral kidney is normal. Recent reports suggest using NSS for tumors up to 7 cm in diameter, particularly for polar tumors that do not extend into the renal hilum.

The major disadvantage of NSS is the small risk (1-6%) of local tumor recurrence due to undetected microscopic multifocal RCC in the remnant of the operated kidney. Partial nephrectomy is also associated with a higher risk of bleeding and urine leak. Despite this higher complication rate, saving the normal nephrons in the kidney reducesthe risk of impaired kidney function and its associated complications.

Laparoscopic partial nephrectomy is a new modality that is increasingly used. It offers faster convalescence than open partial nephrectomy. However, it is associated with a higher rates of positive margins, major intraoperative complications, and urologic complication rates. Laparoscopic partial nephrectomy should be reserved for patients with small exophytic tumors and should be performed by a well-trained laparoscopic urologist.