September 21, 2008 Leave a comment
Renal cell carcinoma (RCC) is the most common malignancy of the kidney and accounts for about 3% of all adult neoplasms. The estimated number of new cases of renal cell carcinoma in the United States in 1997 is 28,000 with a projected 11,300 deaths, and this incidence is expected to increase as a result of the expanded use of radiographic imaging.7 Because renal cell carcinoma is relatively refractory to chemotherapy and radiation therapy, surgery in general and radical nephrectomy in particular has evolved as the primary treatment in patients with clinically localized and locally advanced disease.
Radical nephrectomy is defined as resection of Gerota’s fascia and its entire contents including the kidney, perinephric fat and lymphatics, and ipsilateral adrenal gland. In theory, complete surgical excision of all tumor with negative surgical margins would offer the best opportunity for cure in patients with renal cell carcinoma. This argument would favor radical nephrectomy over simple nephrectomy, given the frequent propensity of the tumor to extend microscopically outside of the renal capsule and into perinephric fat. Thus, although no randomized trial has demonstrated the superiority of radical nephrectomy over simple nephrectomy, multiple series have documented improved survival in patients with renal cell carcinoma treated with radical nephrectomy over the past 30 years.2,3,4 and 8
Between 85% and 90% of all solid renal masses are renal cell carcinoma, and, therefore, the diagnosis of renal cell carcinoma should be considered in all patients with a suspected solid renal mass. A renal mass detected on either intravenous pyelography or ultrasound is usually confirmed by computed tomography (CT scan). Typically, renal cell carcinomas are characterized on CT scan by a solid parenchymal mass with a heterogeneous density and enhancement with intravenous contrast injection (between 15 and 40 Hounsfield units). However, despite modern imaging, some benign tumors of the kidney may be indistinguishable and confirmed only after surgical excision. Additionally, metastatic deposits from a variety of malignancies including lung and breast cancers may involve the kidney and should be considered in patients with a known primary. The role of percutaneous biopsy or needle aspiration in differentiating an indeterminate renal mass remains controversial, and the absence of malignant cells on biopsy does not rule out the possibility of a neoplasm. For this reason, percutaneous renal biopsy for the purpose of diagnosis should be used only in selected cases.
Clinical staging in patients suspected of renal cell carcinoma usually includes a contrast-enhanced CT scan of the abdomen; however, MRI is used occasionally and is particularly useful in patients with a history of a contrast allergy, renal insufficiency, or a suspected vena caval thrombus. From these imaging modalities, a number of factors can be determined, including the size and resectability of the primary, the presence or absence of lymphadenopathy or metastasis, involvement of adjacent structures, and the status of the contralateral kidney. A chest x-ray is obtained to rule out lung metastasis. Bone scans are performed in any patients with symptoms referable to the bone, as well as an elevation in serum alkaline phosphatase or hypercalcemia. In cases of suspected vena caval involvement, Doppler ultrasound is a useful screening tool. If results are equivocal, or if a vena caval thrombus is confirmed, a vascular phase MRI is usually able to determine the level of extension of the tumor thrombus, which allows the surgeon to properly plan an operative strategy.
INDICATIONS FOR SURGERY
The indication for radical nephrectomy is a clinically localized solid renal mass in a patient with a normal contralateral kidney. Patients with solitary kidneys, renal insufficiency, and bilateral renal masses should be considered candidates for nephron-sparing surgery. A thorough preoperative history and physical examination should be performed before the procedure. If significant comorbidities are suspected, consultation with the appropriate physician is recommended. The patient should be expected to physically withstand the operation and have a reasonable overall performance status and a 5-year life expectancy.
In general, radical nephrectomy in patients with metastatic disease is performed for palliation, such as those patients with intractable pain or life-threatening hemorrhage who fail conservative treatment. Also, radical nephrectomy may be performed in the setting of an approved investigational protocol. Radical nephrectomy as a potential adjunct to enhance the effectiveness of biological response modifiers in patients with metastatic renal cell carcinoma remains experimental. The role of radical nephrectomy in patients with a solitary metastatic site is controversial; however, 5-year survival rates of 30% have been reported in selected patients, with best results reported in patients with solitary pulmonary metastases.2
Although local extension of primary renal cell carcinoma into the perinephric fat, vena cava, or ipsilateral adrenal gland may portend a worse prognosis, in the absence of metastatic disease these factors alone should not dissuade the surgeon from attempting a radical nephrectomy. Additionally, radical nephrectomy has been successfully performed in the setting of direct extension of the tumor into adjacent organs such as the liver, colon, or psoas muscle. However, surgical removal in this setting is technically difficult and is associated with a higher morbidity and a potentially poor prognosis. Therefore, it should be attempted only in selected patients without obvious nodal or metastatic disease and in cooperation with appropriate surgical consultants. The role of regional lymphadenectomy at the time of radical nephrectomy remains controversial, and presently most patients should undergo only a limited unilateral lymphadenectomy for the purpose of staging.2
Surgery remains the only effective and potentially curative form of therapy for primary RCC. Along this line, the main challenge to radical nephrectomy in the near future appears to be from more conservative surgical approaches. Partial nephrectomy, enucleation, and wedge resection have recently been proposed in small, clinically localized RCC, with excellent early results (Chapter 6).6 Arguments against partial nephrectomy include the potential for local recurrence, tumor multifocality, and the potential for increased complications.
The routine removal of the ipsilateral adrenal gland at the time of radical nephrectomy has also been questioned, particularly in small tumors and tumors not involving the upper pole.9 The use of laparoscopic techniques is currently expanding, and recently laparoscopic nephrectomy has been reported in patients with small tumors, although concerns over potential for tumor spillage and alteration of pathologic staging remain to be addressed.5 Currently, chemotherapy and radiation therapy have proven to be inadequate treatment in primary renal cell carcinoma.2
There are a variety of factors that influence the choice of incision during radical nephrectomy. These include location of the affected kidney, tumor size and characteristics, body habitus, and physician preference. There are advantages and disadvantages to each incision, and it is important to be familiar with several approaches to the kidney, as no one incision is appropriate in all settings. The most commonly used incisions for radical nephrectomy are the flank, thoracoabdominal, and transabdominal (subcostal or chevron) (Fig. 7-1).
The flank approach is an excellent choice for a variety of reasons. First, it allows direct access to the retroperitoneum and kidney, and the entire procedure can often be performed in an extrapleural and extraperitoneal fashion. Additionally, the incision is anatomic in that it follows the track of the intercostal nerves with minimal risk of denervation. However, in large tumors, tumors involving the upper pole, or in situations where vena cava access is critical, a flank approach may be suboptimal. Although a flank approach may be performed through a subcostal incision, an 11th or 12th rib incision is superior for exposure of the upper pole and ipsilateral adrenal gland during radical nephrectomy.
The patient is positioned on an inflatable mattress in the lateral decubitus position with the upper chest at about a 45 degree angle. An axillary roll is placed under the patient to cushion against pressure on the brachial plexus, and the elbows are padded to prevent ulnar nerve injury. The upper arm is draped across the body and placed on a Mayo stand or a padded support. The lower leg is flexed at 90 degrees, and the upper leg is extended over one or two pillows. The kidney rest is raised and the table is flexed to elevate the flank, and the table is adjusted to make the flank horizontal to the floor. The inflatable mattress is then activated, and the patient is secured with wide tape.
An 11th or 12th rib incision is made based on several factors including the kidney position, the cephalad extent of the tumor, and the patient’s body habitus. A general rule is to incise over the rib that, when extended medially, will position the incision over the renal hilum. The incision is then made over the rib from the posterior axillary line to the tip and extended medially as far as necessary, which usually stops short of the lateral border of the rectus abdominis Figure 7-2). The latissimus dorsi is divided, and the upper portion of the incision is carried down to the rib. At this point a partial rib resection may be accomplished as shown in (Fig. 7-3). An Alexander periosteal elevator is used to deflect the periosteum from the bone to avoid injury to the intercostal bundle located under the inferior portion of the rib. A Doyen elevator is then used to strip the periosteum from the entire undersurface of the rib to be resected. Next, a rib cutter is used to divide the proximal segment of the rib. Alternatively, the incision may be created between the ribs in the intercostal space.
The posterior layer of the periosteum is then incised carefully, and the pleura is protected superiorly. Anteriorly, the external and internal oblique muscles are divided, and the transversus abdominis muscle is split in the direction of its fibers, taking care not to enter the peritoneum. The peritoneum is swept medially, and the intermediate stratum of the retroperitoneal connective tissue is incised sharply to expose the paranephric space. Approaching this in a posterior fashion with early identification of the psoas muscle helps to keep proper orientation. A self-retaining retractor such as a Finochetto or Balfour helps to maintain exposure. A radical nephrectomy is then performed.
The wound is closed after checking to ensure that no injury to the pleura has occurred (see complications). The table flex is released, and the kidney rest is lowered. The posterior layer consisting of the fascia of the transversus abdominis and the internal oblique is closed in a running fashion with #1 PDS or Prolene. The anterior layer of external oblique fascia is closed with a running #1 PDS or Prolene. Alternatively, interrupted figure-of-eight sutures of #1 Vicryl can be used for both layers. The skin is closed in accordance with surgeon preference.
The thoracoabdominal approach allows for excellent exposure of large tumors as well as upper-pole tumors, particularly on the left. Additionally, it affords easy access to the adrenal gland and thoracic cavity. The patient is positioned with the hips flat and with the break of the table located just above the iliac crest. The pelvis can be torqued up to about 30 degrees if necessary. The patient’s ipsilateral shoulder is rotated 45 degrees, and the ipsilateral arm is extended over the table and properly supported on a Mayo stand or padded arm rest Figure 7-4). It is important to properly pad all pressure points including between the legs and the contralateral shoulder. The kidney rest may be elevated to accentuate the proper extension, and the break in the table is made to optimize the incision. After positioning, the patient is secured with wide adhesive tape.
The thoracoabdominal incision is made over the bed of the eighth, ninth, or tenth rib, depending on the surgeon’s preference based on patient and tumor characteristics. The incision may be made between the ribs, or a portion of the rib may be removed. The incision is made over the rib beginning at the posterior axillary line. The incision is carried medially across the costal cartilage margin to the midline and then carried down the midline to the umbilicus. Alternatively, the medial portion of the incision may be carried across the midline or combined with a low midline to form a “T.” The latissimus dorsi is divided, and the upper portion of the incision is carried down to the rib. At this point, a rib resection can be performed as previously described (Fig. 7-3).
The peritoneum may be entered by incising the external and internal obliques, the transversus abdominis, and the ipsilateral rectus belly. Next, the costochondral cartilage at the inferior portion of the upper thoracic incision is divided, and the chest is entered along the entire length of the periosteal bed. The pleural space is entered, and care should be taken not to injure the lung. The lung is protected by pads, and the diaphragm is divided in the direction of the muscle fibers, which helps to avoid injury to the phrenic nerve. A self-retaining retractor such as a Finochetto or a Balfour is properly padded and placed to maintain exposure. A radical nephrectomy is then performed.
After completion of the radical nephrectomy, the table flex is removed, and the diaphragm is closed with interrupted 2-0 silk sutures with knots placed on the inferior side. After a #32 chest tube has been inserted through a separate incision and properly positioned, the ribs are reapproximated with 2-0 chromic pericostal sutures. The thoracic portion of the incision is closed with interrupted figure-of-eight 1-0 Vicryl sutures through all layers of the chest wall. The medial portion of the intercostal muscle closure should include at least a small portion of the diaphragm. An intercostal nerve block is administered before closure and may be accomplished by injecting approximately 10 ml of 0.5% lidocaine or bupivicaine hydrochloride into the intercostal space of the incision and two interspaces above and below. The costal cartilage can be reapproximated with 0 chromic suture. The peritoneum is closed with a running 2-0 chromic, although this is optional. The posterior rectus fascia, the fascia of the transversus abdominis, and the internal oblique muscles are closed with a running or interrupted #1 PDS suture. The anterior rectus and the external oblique fascia are closed with either a running or interrupted #1 PDS or Maxon suture. Skin closure is determined by surgeon preference. The chest tube is secured in place with a 0 silk and taped securely in place.
Transabdominal (Chevron or Anterior Subcostal)
Anterior incisions offer several advantages including excellent exposure of the renal pedicle and access to the entire abdomen and contralateral retroperitoneum. With the patient in the supine position, the operative side is elevated slightly with a flank roll, and the patient hyperextended to accentuate the line of incision. An incision is made from near the tip of the 11th or 12th rib on the ipsilateral side two fingerbreadths below the costal margin and extended medially to the xyphoid process. The incision is then gently curved across the midline and as far laterally as necessary for exposure up to near the tip of the contralateral 11th rib.
Occasionally, only a portion of the contralateral side will be incised just across the rectus abdominis. The incision is carried down to the anterior rectus fascia, which is then divided (Fig. 7-5). Next, the external and internal oblique fascia and muscles are divided, and the fibers of the transversus abdominis split. The rectus muscle and posterior rectus sheath are divided with electrocautery by placing a straight clamp or army–navy retractor underneath and gently elevating it. The superior epigastric artery is ligated with 2-0 silk and divided when encountered. The peritoneal cavity is then entered, and the falciform ligament is ligated between two Kelly clamps, divided, and tied with 0 silk suture. To facilitate exposure, the lower aspect of the incision is rotated caudally with a rolled towel placed underneath the skin, and the fascia sutured to the lower portion of the abdominal wall with two #2 nylon sutures. Use of a self-retaining retractor such as a Wishbone Omni-Tract is helpful. A radical nephrectomy is then performed.
Closure of the wound is performed after the table is returned to the horizontal position. The wound is then closed in two layers. The posterior layer consisting of the fascia of the transversus abdominis and the internal oblique laterally along with the posterior rectus fascia medially is closed with two running #1 PDS sutures, each starting at the lateral aspect and running medially to the midline. The anterior layer of external oblique and anterior rectus fascia is closed in a similar fashion with #1 PDS. Alternatively, the layers can be closed with interrupted #1 Vicryl. Occasionally, it is helpful to place a U stitch of #1 Prolene at the apex of the chevron incision before closure, which includes the rectus fascia on either side of the midline, securing this suture after the anterior fascia has been approximated. The skin is then closed according to the surgeon’s preference.
Irrespective of the choice of incision, certain caveats are universal for the safe and successful completion of a radical nephrectomy. This includes a systematic approach with careful mobilization of Gerota’s fascia and early vascular control. For a flank approach, the posterior peritoneum lateral to the colon is incised along the length of the descending colon (left side) or ascending colon (right side) and reflected medially. For left-sided exposure, the lienorenal ligament is incised to mobilize the spleen cephalad. On the right side, the hepatic flexure of the colon is mobilized. The ureter is identified and encircled with a vessel loop. The gonadal vein is ligated and divided. The plane between the mesentery of the colon and Gerota’s fascia is then developed using a combination of sharp and blunt dissection. On the right side, the vena cava is exposed by Kocherizing the duodenum. Using blunt dissection, the retroperitoneal fat overlying the renal vessels is separated, exposing the renal hilum. It is often helpful to ligate and divide the ureter before this to allow for mobilization and upward displacement of the lower pole of the kidney.
The dissection is then carried cephalad along the vena cava (right side) or aorta (left side). On the right side, the right renal vein is identified exiting from the vena cava, isolated, and encircled with a right-angle clamp and a 0 silk suture and tagged. After identification of the renal artery (exposure may be enhanced by the use of a vein retractor on the renal vein), the artery is dissected free and cleaned for a distance of approximately 2 to 3 cm. With a right-angle clamp, the renal artery is encircled, and 2-0 silk ties are passed (Fig. 7-6). The sutures are then separated and tied, allowing a safe distance for division of the artery. A small hemoclip or a 3-0 silk suture ligature may be placed on the proximal aspect of the artery before division. A right-angle clamp is placed under the artery to be divided and gently elevated, and the artery is cut with either a knife (#15 blade) or Metzenbaum scissors. The right renal vein is then ligated in a similar fashion with 0 silk sutures.
On the left, the renal vein is isolated as it courses over the aorta. The left adrenal and gonadal veins are identified emanating from the left renal vein, and, if present, a posteriorly directed lumbar venous tributary is noted. A right-angle clamp is passed around the renal vein, followed by a 0 silk suture proximal to the tributaries, and tagged. The venous tributaries are then individually ligated and divided with 2-0 or 3-0 silk and small hemoclips where necessary, leaving the 2-0 silk suture on the main renal vein tagged (Fig. 7-7). The left renal artery and vein are then ligated similarly to the technique described above for the right side.
Gerota’s fascia is then mobilized posteriorly and superiorly using a combination of sharp and blunt dissection. Hemoclips along the superior and medial border are useful to control any potential bleeding during this portion of the procedure. The adrenal hilum is then dissected from caudal to cranial with the aid of either hemoclips or straight clamps and ties. On the right side, the short posteriorly located right adrenal vein should be anticipated as it exits directly from the vena cava. When encountered, the right adrenal vein is isolated, ligated, and divided. The specimen is then delivered, and meticulous hemostasis is achieved.
The potential for bleeding during radical nephrectomy necessitates careful patient preparation and preoperative planning to significantly reduce the chances. Any medications that interfere with platelet function or clotting should be discontinued, and patients should be type and cross matched for 2 units of packed red blood cells. The patient should have either two large-bore peripheral intravenous lines or a central venous line to allow for rapid infusion of fluids or blood products.
Bleeding during radical nephrectomy may be from a variety of locations including the renal hilum, collateral tumor vessels, or adjacent structures. Venous bleeding is usually the most problematic. The first maneuver is to apply direct pressure to the area of bleeding. The point of bleeding is then carefully exposed and controlled by a suture ligature. In the case of venal caval injury, a Satinsky clamp is placed, and a vascular 5-0 or 6-0 Prolene suture is used to oversew the defect. Lumbar veins should be exposed by gentle retraction of the vena cava, appropriately clamped, ligated with vascular silk suture, and divided. Renal artery bleeding may be controlled by direct pressure on the aorta proximally until adequate exposure can be obtained, and the artery is then ligated. Only in rare circumstances will a pedicle clamp or mass ligature be necessary.
Adrenal tears may result in significant hemorrhage during radical nephrectomy, particularly on the right side, where the short adrenal vein enters into the vena cava directly posterior. Control of the right adrenal vein should be attempted only after control of the vena cava, adequate exposure, and proper suction. The vein is then ligated with a 2-0 or 3-0 silk tie or a vascular Prolene. Venous bleeding from a torn adrenal gland can be oversewn with a running suture or stopped by placement of surgical clips. However, removal of the ipsilateral adrenal may be the most expeditious method of controlling bleeding.
Failure to recognize a rent in the pleura during flank incision will result in a pneumothorax. Small openings in the pleura may be recognized by filling the flank wound with sterile water and administering a deep inspiratory breath. Small tears recognized intraoperatively can be managed by closing the pleura with a 3-0 chromic pursestring suture over a 12 Fr or 14 Fr Robinson catheter. Before it is removed, all air is aspirated from the pleural cavity either by suction or by placing the Robinson catheter under water and administering a deep inspiratory breath. The air is evacuated from the pleural space, and the tube is removed while the pursestring suture is simultaneously tied in place. Alternatively, the Robinson catheter can be temporarily left in place with the chromic suture secured and the fascial layers closed around the catheter, which exits from the corner of the wound. Just before skin closure, after all air has been evacuated under water seal as described above, the catheter is removed. The latter technique is helpful when the pleura is attenuated or contains multiple small holes that are not easily closed. Alternatively, a 22 Fr or 24 Fr chest tube may be placed and left to suction.
An upright end-expiratory chest x-ray is obtained after all flank incisions to ensure that no significant pneumothorax exists. A small (usually less than 15%), asymptomatic pneumothorax can be followed conservatively with serial chest x-rays and oxygen therapy. In a symptomatic or large pneumothorax, aspiration of the pleural space using a needle or a central venous catheter (Seldinger technique) introduced just over the rib in the anterior fourth or fifth interspace can be therapeutic. However, if these attempts are not successful, a chest tube should be inserted and placed on suction.
Injuries to the colon during radical nephrectomy are uncommon. In locally advanced tumors suspected of extension into either the colon or mesentery, patients should undergo a mechanical and antibiotic bowel preparation. Segmental colon resection and primary anastomosis should be possible in most cases. Inadvertent injury to the colon during radical nephrectomy can usually be repaired primarily; however, in situations where there is gross spillage of fecal contents or a devascularized segment, a diverting colostomy should be considered, and a general surgery consultation is advisable. Defects in the mesentery of colon should be closed to prevent internal herniation of peritoneal contents.
Right radical nephrectomy is also associated with the potential for injury to the duodenum and liver. The duodenum must be carefully mobilized, and care must be taken to properly pad retractors to prevent injury to the bowel and adjacent structures including the head of the pancreas. The second portion of the duodenum may be injured during a right radical nephrectomy. Duodenal hematomas should only be observed, but rapidly enlarging hematomas will require control of the bleeding, and an intraoperative general surgery consultation should be obtained. Duodenal lacerations should be repaired in multiple layers with interrupted nonabsorbable sutures for the mucosal and serosal layers.10 When possible, an omental wrap may provide additional support, and all patients should be managed with a nasogastric tube during the postoperative period.
Superficial liver lacerations are repaired with absorbable horizontal mattress sutures utilizing a Surgicel or Hemopad bolster. Deep liver lacerations, which may involve the hepatic ducts, could result in bile leakage and should be drained following repair. Direct invasion of the liver by renal cell carcinoma is rare; however, resection including en-bloc removal is possible in selected cases. If a major lobectomy or a partial hepatectomy is to be performed because of either direct extension or major hemorrhage, a general surgeon should be present.
Splenic injury is one of the most common intraoperative complications during a left nephrectomy, with an incidence as high as 10% in some series. Most superficial lacerations or tears can be managed conservatively without the need for splenectomy. Although minor tears may require only some gentle pressure and the application of a Hemopad or Surgicel with Avitene application, closure of a moderate splenic capsular tear is facilitated through the use of nonabsorbable sutures over bolsters of Surgicel. Major hemorrhage secondary to severe splenic lacerations may require splenectomy. The splenic artery and vein are controlled by compressing these structures, located in the splenic hilum near the tail of the pancreas. Initially, this can be accomplished manually by compressing the tail of the pancreas between the thumb and the forefinger. Once bleeding has been temporarily controlled, the spleen is mobilized by dividing the splenocolic and splenorenal ligaments as well as taking down the peritoneal attachments to the diaphragm. The short gastric vessels are then ligated, and the hilum of the spleen is dissected free from the tail of the pancreas. The splenic artery and vein are ligated and divided. The pancreas should be inspected closely to rule out inadvertent injury. Following splenectomy, patients will have a reduced resistance to pneumococcal organisms and should receive Pneumovax and Hibtiter on a yearly basis.
Surgical excision remains the only effective and potentially curative therapy for clinically localized RCC. Pathologic staging remains the best prognostic variable in terms of patient survival, and the two most commonly used staging systems are the Robson classification and the American Joint Committee on Cancer recommendations (TNM) classification.1,8 Both staging systems have demonstrated an inverse relationship between survival and increasing stage, but the TNM is generally thought to be more accurate because it more precisely defines the extent of disease.
In patients treated with radical nephrectomy and found to have tumors confined to the kidney (Robson stage I), the 5-year survival is between 60% and 90% compared with 47% to 67% in patients whose RCC is confined to Gerota’s fascia (Robson stage II). Survival for patients with distant metastases is poor with 5-year survival of between 5% and 10%.2 Under the TNM staging system, the 5-year survival for patients with organ-confined tumors treated with radical nephrectomy for T1N0M0 tumors is between 80% and 91%, whereas that for T2N0M0 tumors is 68% to 92%.3,4 For those patients with T3aN0M0 (tumor invading into the adrenal gland) and T3bN0M0 (tumor invading into the renal vein) carcinomas, the 5-year survival is 77% and 59%, respectively. Finally, patients with node-positive disease (N1–3M0) have a 5-year survival between 15% and 52%.
Although radical nephrectomy remains the standard of care for unilateral renal cell carcinoma, more conservative surgical options have been proposed. Recently, excellent results have been seen in patients treated with nephron-sparing surgery, with 5-year cancer-specific survivals of greater than 90% for small, unilateral, stage I tumors.9 The ultimate choice of surgical treatment in patients with these favorable clinical features, and in particular the risk of local recurrence and cancer-specific survival, remains to be determined through long-term follow-up. Currently, radical nephrectomy remains the treatment of choice in patients with clinically localized renal cell carcinoma and the standard against which future alternative surgical strategies will be measured.